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  • Blackwell Publishing Ltd
  • International Union of Crystallography
  • 2020-2022  (393)
  • 2000-2004
  • 1980-1984
  • 1965-1969  (2,422)
  • 1925-1929
  • 2021  (393)
  • 1965  (2,422)
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  • 1
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    Evaluating learning spaces in flood risk management in Germany: Lessons for governance research (2021)
    Blackwell Publishing Ltd | Oxford, UK
    Details
    Publication Date: 2021-06-28
    Description: Efforts to collaboratively manage the risk of flooding are ultimately based on individuals learning about risks, the decision process, and the effectiveness of decisions made in prior situations. This article argues that much can be learned about a governance setting by explicitly evaluating the relationships through which influential individuals and their immediate contacts receive and send information to one another. We define these individuals as “brokers,” and the networks that emerge from their interactions as “learning spaces.” The aim of this article is to develop strategies to identify and evaluate the properties of a broker's learning space that are indicative of a collaborative flood risk management arrangement. The first part of this article introduces a set of indicators, and presents strategies to employ this list so as to systematically identify brokers, and compare their learning spaces. The second part outlines the lessons from an evaluation that explored cases in two distinct flood risk management settings in Germany. The results show differences in the observed brokers' learning spaces. The contacts and interactions of the broker in Baden‐Württemberg imply a collaborative setting. In contrast, learning space of the broker in North Rhine‐Westphalia lacks the same level of diversity and polycentricity.
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Description: MWK Baden‐Württemberg
    Keywords: 333.91 ; brokerage ; collaborative water governance ; comanagement ; comparative analysis ; social networks
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  • 2
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    Facilitated crystal handling using a simple device for evaporation reduction in microtiter plates (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-03-30
    Description: In the past two decades, most of the steps in a macromolecular crystallography experiment have undergone tremendous development with respect to speed, feasibility and increase of throughput. The part of the experimental workflow that is still a bottleneck, despite significant efforts, involves the manipulation and harvesting of the crystals for the diffraction experiment. Here, a novel low‐cost device is presented that functions as a cover for 96‐well crystallization plates. This device enables access to the individual experiments one at a time by its movable parts, while minimizing evaporation of all other experiments of the plate. In initial tests, drops of many typically used crystallization cocktails could be successfully protected for up to 6 h. Therefore, the manipulation and harvesting of crystals is straightforward for the experimenter, enabling significantly higher throughput. This is useful for many macromolecular crystallography experiments, especially multi‐crystal screening campaigns.
    Description: A simple and low‐cost device has been developed to minimize evaporation in microtiter plates for easy crystal handling and harvesting. image
    Keywords: 548 ; evaporation reduction ; crystal handling ; crystal harvesting ; crystallographic fragment screening
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  • 3
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    Cation distribution in Cu2ZnSnSe4, Cu2FeSnS4 and Cu2ZnSiSe4 by multiple‐edge anomalous diffraction (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-03-30
    Description: Multiple‐Edge Anomalous Diffraction (MEAD) has been applied to various quaternary sulfosalts belonging to the adamantine compound family in order to validate the distribution of copper, zinc and iron cations in the structure. Semiconductors from this group of materials are promising candidates for photovoltaic applications. Their properties strongly depend on point defects, in particular related to cation order–disorder. However, Cu+, Zn2+ and Fe2+ have very similar scattering factors and are all but indistinguishable in usual X‐ray diffraction experiments. Anomalous diffraction utilizes the dependency of the atomic scattering factors f′ and f′′ of the energy of the radiation, especially close to the element‐specific absorption edges. In the MEAD technique, individual Bragg peaks are tracked over an absorption edge. The intensity changes depending on the structure factor can be highly characteristic for Miller indices selected for a specific structural problem, but require very exact measurements. Beamline KMC‐2 at synchrotron BESSY II, Berlin, has been recently upgraded for this technique. Anomalous X‐ray powder diffraction and XAFS compliment the data. Application of this technique confirmed established cation distribution in Cu2ZnSnSe4 (CZTSe) and Cu2FeSnS4 (CFTS). In contrast to the literature, cation distribution in Cu2ZnSiSe4 (CZSiSe) is shown to adopt a highly ordered wurtz‐kesterite structure type.
    Description: Multiple‐Edge Anomalous Diffraction (MEAD) has been applied to various quaternary sulfosalts belonging to the adamantine compound family in order to validate the distribution of copper, zinc and iron cations in the structure. Application of this technique confirms established cation distribution in Cu2ZnSnSe4 (CZTSe) and Cu2FeSnS4 (CFTS), but in Cu2ZnSiSe4 (CZSiSe) the cation distribution is shown to adopt a highly ordered wurtz‐kesterite structure type in contrast to the literature. image
    Keywords: 548 ; synchrotron ; anomalous diffraction ; semiconductor ; MEAD
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  • 4
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    The copper(II)‐binding tripeptide GHK, a valuable crystallization and phasing tag for macromolecular crystallography (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-03-27
    Description: The growth of diffraction‐quality crystals and experimental phasing remain two of the main bottlenecks in protein crystallography. Here, the high‐affinity copper(II)‐binding tripeptide GHK was fused to the N‐terminus of a GFP variant and an MBP‐FG peptide fusion. The GHK tag promoted crystallization, with various residues (His, Asp, His/Pro) from symmetry molecules completing the copper(II) square‐pyramidal coordination sphere. Rapid structure determination by copper SAD phasing could be achieved, even at a very low Bijvoet ratio or after significant radiation damage. When collecting highly redundant data at a wavelength close to the copper absorption edge, residual S‐atom positions could also be located in log‐likelihood‐gradient maps and used to improve the phases. The GHK copper SAD method provides a convenient way of both crystallizing and phasing macromolecular structures, and will complement the current trend towards native sulfur SAD and MR‐SAD phasing.
    Description: A novel three‐residue tag containing the residues GHK that can be used to promote crystallization and in SAD phasing experiments using its tightly bound copper ion is described. image
    Keywords: 548 ; phasing ; crystallization ; GHK ; SAD
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  • 5
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    Determining paracrystallinity in mixed‐tacticity polyhydroxybutyrates (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-03-30
    Description: Recently, the authors reported on the development of crystallinity in mixed‐tacticity polyhydroxybutyrates. Comparable values reported in the literature vary depending on the manner of determination, the discrepancies being partially attributable to scattering from paracrystalline portions of the material. These portions can be qualified by peak profile fitting or quantified by allocation of scattered X‐ray intensities. However, the latter requires a good quality of the former, which in turn must additionally account for peak broadening inherent in the measurement setup, and due to limited crystallite sizes and the possible presence of microstrain. Since broadening due to microstrain and paracrystalline order both scale with scattering vector, they are easily confounded. In this work, a method to directionally discern these two influences on the peak shape in a Rietveld refinement is presented. Allocating intensities to amorphous, bulk and paracrystalline portions with changing tactic disturbance provided internal validations of the obtained directional numbers. In addition, the correlation between obtained thermal factors and Young's moduli, determined in earlier work, is discussed.
    Description: A method to robustly determine paracrystalline contents from Rietveld‐refined powder X‐ray data is presented and discussed for the example of mixed‐tacticity polyhydroxybutyrates. image
    Keywords: 548 ; polyhydroxybutyrates ; mixed tacticity ; paracrystallinity ; Rietveld refinement ; thermal factors
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  • 6
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    Concepts for nondestructive and depth‐resolved X‐ray residual stress analysis in the near‐surface region of nearly single crystalline materials with mosaic structure (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-03-27
    Description: Two evaluation concepts for nondestructive depth‐resolved X‐ray residual stress analysis in the near‐surface region of materials with cubic symmetry and nearly single crystalline structure are introduced by simulated examples. Both concepts are based on the same data acquisition strategy, which consists in the determination of lattice‐spacing depth profiles along the ⟨hkl⟩ poles by stepwise sample rotation around the scattering vector. Segmentation of these profiles parallel to the sample surface provides the lattice strain state as a function of depth. The first evaluation concept extends the crystallite group method developed for materials with pronounced crystallographic texture by the feature of depth resolution and can be applied to samples with arbitrary orientation. The second evaluation concept, which adapts the linear regression approach of the sin2ψ method for the case of single crystalline materials, is restricted to samples with (001) orientation. The influence of the strain‐free lattice parameter a0 on residual stress analysis using both evaluation concepts is discussed on the basis of explicitly derived relations.
    Description: Two data evaluation concepts are proposed for nondestructive and depth‐resolved X‐ray residual stress analysis by means of energy‐dispersive diffraction on materials featuring cubic symmetry and a nearly single crystalline structure. image
    Keywords: 548 ; residual stress ; X‐ray diffraction ; depth‐resolved analysis ; mosaic crystals
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  • 7
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    X‐ray dichroism in polyimide caused by non‐resonant scattering (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
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    Publication Date: 2021-03-30
    Description: Dichroism is one of the most important optical effects in both the visible and the X‐ray range. Besides absorption, scattering can also contribute to dichroism. This paper demonstrates that, based on the example of polyimide, materials can show tiny dichroism even far from electronic resonances due to scattering. Although the effect is small, it can lead to a measurable polarization change and might have influence on highly sensitive polarimetric experiments.
    Description: Aligned molecules, for example in polyimide foils, lead to small dichroism even far from resonances, which can be revealed by high‐precision X‐ray polarimetry. image
    Keywords: 548 ; polyimide ; polarization ; X‐ray polarimetry ; wide‐angle scattering ; X‐ray dichroism
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  • 8
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    Elastic stiffness coefficients of thiourea from thermal diffuse scattering (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-03-27
    Description: The complete elastic stiffness tensor of thiourea has been determined from thermal diffuse scattering (TDS) using high‐energy photons (100 keV). Comparison with earlier data confirms a very good agreement of the tensor coefficients. In contrast with established methods to obtain elastic stiffness coefficients (e.g. Brillouin spectroscopy, inelastic X‐ray or neutron scattering, ultrasound spectroscopy), their determination from TDS is faster, does not require large samples or intricate sample preparation, and is applicable to opaque crystals. Using high‐energy photons extends the applicability of the TDS‐based approach to organic compounds which would suffer from radiation damage at lower photon energies.
    Description: The elastic stiffness coefficients of thiourea are determined from thermal diffuse scattering. image
    Keywords: 548 ; thermal diffuse scattering ; elastic stiffness ; thiourea
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  • 9
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    Fast fitting of reflectivity data of growing thin films using neural networks (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
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    Publication Date: 2021-07-03
    Description: X‐ray reflectivity (XRR) is a powerful and popular scattering technique that can give valuable insight into the growth behavior of thin films. This study shows how a simple artificial neural network model can be used to determine the thickness, roughness and density of thin films of different organic semiconductors [diindenoperylene, copper(II) phthalocyanine and α‐sexithiophene] on silica from their XRR data with millisecond computation time and with minimal user input or a priori knowledge. For a large experimental data set of 372 XRR curves, it is shown that a simple fully connected model can provide good results with a mean absolute percentage error of 8–18% when compared with the results obtained by a genetic least mean squares fit using the classical Parratt formalism. Furthermore, current drawbacks and prospects for improvement are discussed.
    Description: Artificial neural networks trained with simulated data are shown to correctly and quickly determine film parameters from experimental X‐ray reflectivity curves.
    Keywords: 548 ; X‐ray reflectivity ; machine learning ; organic semi‐conductors ; neural networks
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  • 10
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    Numerically stable form factor of any polygon and polyhedron (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
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    Publication Date: 2021-06-05
    Description: Coordinate‐free expressions for the form factors of arbitrary polygons and polyhedra are derived using the divergence theorem and Stokes's theorem. Apparent singularities, all removable, are discussed in detail. Cancellation near the singularities causes a loss of precision that can be avoided by using series expansions. An important application domain is small‐angle scattering by nanocrystals.
    Description: Coordinate‐free expressions for the form factors of arbitrary polygons and polyhedra are derived using the divergence theorem and Stokes's theorem. Series expansions are used to ensure numeric precision close to apparent singularities. image
    Keywords: 548 ; form factors ; polyhedra ; Fourier shape transform
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  • 11
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    ROBL‐II at ESRF: a synchrotron toolbox for actinide research (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-30
    Description: ROBL‐II provides four different experimental stations to investigate actinide and other alpha‐ and beta‐emitting radionuclides at the new EBS storage ring of ESRF within an energy range of 3 to 35 keV. The XAFS station consists of a highly automatized, high sample throughput installation in a glovebox, to measure EXAFS and conventional XANES of samples routinely at temperatures down to 10 K, and with a detection limit in the sub‐p.p.m. range. The XES station with its five bent‐crystal analyzer, Johann‐type setup with Rowland circles of 1.0 and 0.5 m radii provides high‐energy resolution fluorescence detection (HERFD) for XANES, XES, and RIXS measurements, covering both actinide L and M edges together with other elements accessible in the 3 to 20 keV energy range. The six‐circle heavy duty goniometer of XRD‐1 is equipped for both high‐resolution powder diffraction as well as surface‐sensitive CTR and RAXR techniques. Single crystal diffraction, powder diffraction with high temporal resolution, as well as X‐ray tomography experiments can be performed at a Pilatus 2M detector stage (XRD‐2). Elaborate radioprotection features enable a safe and easy exchange of samples between the four different stations to allow the combination of several methods for an unprecedented level of information on radioactive samples for both fundamental and applied actinide and environmental research.
    Description: ROBL‐II at ESRF provides four experimental stations to investigate actinides with X‐ray absorption and emission spectroscopy, and with surface, high‐resolution powder, and single‐crystal X‐ray diffractometry.
    Keywords: 549 ; actinides ; EXAFS ; XANES ; HERFD‐XANES ; XAS ; XES ; RIXS ; XRD ; CTR ; RAXR ; surface diffraction
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  • 12
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    ATSAS 3.0: expanded functionality and new tools for small‐angle scattering data analysis (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
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    Publication Date: 2021-03-30
    Description: The ATSAS software suite encompasses a number of programs for the processing, visualization, analysis and modelling of small‐angle scattering data, with a focus on the data measured from biological macromolecules. Here, new developments in the ATSAS 3.0 package are described. They include IMSIM, for simulating isotropic 2D scattering patterns; IMOP, to perform operations on 2D images and masks; DATRESAMPLE, a method for variance estimation of structural invariants through parametric resampling; DATFT, which computes the pair distance distribution function by a direct Fourier transform of the scattering data; PDDFFIT, to compute the scattering data from a pair distance distribution function, allowing comparison with the experimental data; a new module in DATMW for Bayesian consensus‐based concentration‐independent molecular weight estimation; DATMIF, an ab initio shape analysis method that optimizes the search model directly against the scattering data; DAMEMB, an application to set up the initial search volume for multiphase modelling of membrane proteins; ELLLIP, to perform quasi‐atomistic modelling of liposomes with elliptical shapes; NMATOR, which models conformational changes in nucleic acid structures through normal mode analysis in torsion angle space; DAMMIX, which reconstructs the shape of an unknown intermediate in an evolving system; and LIPMIX and BILMIX, for modelling multilamellar and asymmetric lipid vesicles, respectively. In addition, technical updates were deployed to facilitate maintainability of the package, which include porting the PRIMUS graphical interface to Qt5, updating SASpy – a PyMOL plugin to run a subset of ATSAS tools – to be both Python 2 and 3 compatible, and adding utilities to facilitate mmCIF compatibility in future ATSAS releases. All these features are implemented in ATSAS 3.0, freely available for academic users at https://www.embl‐hamburg.de/biosaxs/software.html.
    Description: ATSAS is a comprehensive software suite for the processing, visualization, analysis and modelling of small‐angle scattering data. This article describes developments in the ATSAS 3.0 release, including new programs for data simulation and for the structural modelling of lipids, nucleic acids and polydisperse systems. image
    Keywords: 548 ; small‐angle scattering ; data analysis ; biological macromolecules ; structural modelling ; ATSAS
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  • 13
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    Synthetic resampling strategies and machine learning for digital soil mapping in Iran (2021)
    Blackwell Publishing Ltd | Oxford, UK
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    Publication Date: 2021-07-04
    Description: Most common machine learning (ML) algorithms usually work well on balanced training sets, that is, datasets in which all classes are approximately represented equally. Otherwise, the accuracy estimates may be unreliable and classes with only a few values are often misclassified or neglected. This is known as a class imbalance problem in machine learning and datasets that do not meet this criterion are referred to as imbalanced data. Most datasets of soil classes are, therefore, imbalanced data. One of our main objectives is to compare eight resampling strategies that have been developed to counteract the imbalanced data problem. We compared the performance of five of the most common ML algorithms with the resampling approaches. The highest increase in prediction accuracy was achieved with SMOTE (the synthetic minority oversampling technique). In comparison to the baseline prediction on the original dataset, we achieved an increase of about 10, 20 and 10% in the overall accuracy, kappa index and F‐score, respectively. Regarding the ML approaches, random forest (RF) showed the best performance with an overall accuracy, kappa index and F‐score of 66, 60 and 57%, respectively. Moreover, the combination of RF and SMOTE improved the accuracy of the individual soil classes, compared to RF trained on the original dataset and allowed better prediction of soil classes with a low number of samples in the corresponding soil profile database, in our case for Chernozems. Our results show that balancing existing soil legacy data using synthetic sampling strategies can significantly improve the prediction accuracy in digital soil mapping (DSM). Highlights Spatial distribution of soil classes in Iran can be predicted using machine learning (ML) algorithms. The synthetic minority oversampling technique overcomes the drawback of imbalanced and highly biased soil legacy data. When combining a random forest model with synthetic sampling strategies the prediction accuracy of the soil model improves significantly. The resulting new soil map of Iran has a much higher spatial resolution compared to existing maps and displays new soil classes that have not yet been mapped in Iran.
    Description: Alexander von Humboldt‐Stiftung http://dx.doi.org/10.13039/100005156
    Description: German Research Foundation http://dx.doi.org/10.13039/501100001659
    Description: Soil and Water Research Institute, Agricultural Research, Education and Extension Organization, Karaj, Iran
    Keywords: 631.4 ; covariates ; imbalanced data ; machine learning ; random forest ; soil legacy data
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  • 14
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    XGANDALF – extended gradient descent algorithm for lattice finding (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
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    Publication Date: 2021-03-27
    Description: Serial crystallography records still diffraction patterns from single, randomly oriented crystals, then merges data from hundreds or thousands of them to form a complete data set. To process the data, the diffraction patterns must first be indexed, equivalent to determining the orientation of each crystal. A novel automatic indexing algorithm is presented, which in tests usually gives significantly higher indexing rates than alternative programs currently available for this task. The algorithm does not require prior knowledge of the lattice parameters but can make use of that information if provided, and also allows indexing of diffraction patterns generated by several crystals in the beam. Cases with a small number of Bragg spots per pattern appear to particularly benefit from the new approach. The algorithm has been implemented and optimized for fast execution, making it suitable for real‐time feedback during serial crystallography experiments. It is implemented in an open‐source C++ library and distributed under the LGPLv3 licence. An interface to it has been added to the CrystFEL software suite.
    Description: A description and evaluation are given of XGANDALF, extended gradient descent algorithm for lattice finding, an algorithm developed for fast and accurate indexing of snapshot diffraction patterns. image
    Keywords: 548 ; indexing ; XGANDALF ; CrystFEL ; multiple lattices ; serial crystallography
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  • 15
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    pinkIndexer – a universal indexer for pink‐beam X‐ray and electron diffraction snapshots (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
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    Publication Date: 2021-03-27
    Description: A crystallographic indexing algorithm, pinkIndexer, is presented for the analysis of snapshot diffraction patterns. It can be used in a variety of contexts including measurements made with a monochromatic radiation source, a polychromatic source or with radiation of very short wavelength. As such, the algorithm is particularly suited to automated data processing for two emerging measurement techniques for macromolecular structure determination: serial pink‐beam X‐ray crystallography and serial electron crystallography, which until now lacked reliable programs for analyzing many individual diffraction patterns from crystals of uncorrelated orientation. The algorithm requires approximate knowledge of the unit‐cell parameters of the crystal, but not the wavelengths associated with each Bragg spot. The use of pinkIndexer is demonstrated by obtaining 1005 lattices from a published pink‐beam serial crystallography data set that had previously yielded 140 indexed lattices. Additionally, in tests on experimental serial crystallography diffraction data recorded with quasi‐monochromatic X‐rays and with electrons the algorithm indexed more patterns than other programs tested.
    Description: pinkIndexer, an algorithm developed for indexing of snapshot diffraction patterns recorded with pink‐beam X‐rays, monochromatic X‐rays and electrons, is described and its use evaluated. image
    Keywords: 548 ; indexing ; pinkIndexer ; CrystFEL ; pink X‐ray beam ; serial electron diffraction
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  • 16
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    Crystal structure of human CRM1, covalently modified by 2‐mercaptoethanol on Cys528, in complex with RanGTP (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
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    Publication Date: 2021-06-17
    Description: CRM1 is a nuclear export receptor that has been intensively targeted over the last decade for the development of antitumor and antiviral drugs. Structural analysis of several inhibitor compounds bound to CRM1 revealed that their mechanism of action relies on the covalent modification of a critical cysteine residue (Cys528 in the human receptor) located in the nuclear export signal‐binding cleft. This study presents the crystal structure of human CRM1, covalently modified by 2‐mercaptoethanol on Cys528, in complex with RanGTP at 2.58 Å resolution. The results demonstrate that buffer components can interfere with the characterization of cysteine‐dependent inhibitor compounds.
    Description: The covalent modification of human CRM1 by 2‐mercaptoethanol interferes with the characterization of cysteine‐dependent inhibitor compounds. image
    Keywords: 548 ; nuclear export ; cancer ; exportin 1 ; cysteine modification
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  • 17
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    Impact of biochar on nutrient supply, crop yield and microbial respiration on sandy soils of northern Germany (2021)
    Blackwell Publishing Ltd | Oxford, UK
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    Publication Date: 2021-06-16
    Description: The application of biochar to agricultural soils to increase nutrient availability, crop production and carbon sequestration has gained increasing interest but data from field experiments on temperate, marginal soils are still under‐represented. In the current study, biochar, produced from organic residues (digestates) from a biogas plant, was applied with and without digestates at low (3.4 t ha−1) and intermediate (17.1 t ha−1) rates to two acidic and sandy soils in northern Germany that are used for corn (Zea mays L.) production. Soil nutrient availability, crop yields, microbial biomass and carbon dioxide (CO2) emissions from heterotrophic respiration were measured over two consecutive years. The effects of biochar application depended on the intrinsic properties of the two tested soils and the biochar application rates. Although the soils at the fallow site, with initially low nutrient concentrations, showed a significant increase in pH, soil nutrients and crop yield after low biochar application rates, a similar response was found at the cornfield site only after application of substantially larger amounts of biochar. The effect of a single dose of biochar at the beginning of the experiment diminished over time but was still detectable after 2 years. Whereas plant available nutrient concentrations increased after biochar application, the availability of potentially phytotoxic trace elements (Zn, Pb, Cd, Cr) decreased significantly, and although slight increases in microbial biomass carbon and heterotrophic CO2 fluxes were observed after biochar application, they were mostly not significant. The results indicate that the application of relatively small amounts of biochar could have positive effects on plant available nutrients and crop yields of marginal arable soils and may decrease the need for mineral fertilizers while simultaneously increasing the sequestration of soil organic carbon. Highlights A low rate of biochar increased plant available nutrients and crop yield on marginal soils. Biochar application reduced the availability of potentially harmful trace elements. Heterotrophic respiration showed no clear response to biochar application. Biochar application may reduce fertilizer need and increase carbon sequestration on marginal soils.
    Description: German Academic Exchange Service http://dx.doi.org/10.13039/501100001655
    Description: Institute Strategic Programme grants, “Soils to Nutrition”
    Keywords: 631.4 ; black carbon ; carbon sequestration ; corn ; digestate ; heterotrophic respiration ; marginal soils ; microbial biomass
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  • 18
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    Staircase array of inclined refractive multi‐lenses for large field of view pixel super‐resolution scanning transmission hard X‐ray microscopy (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
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    Publication Date: 2021-06-26
    Description: Owing to the development of X‐ray focusing optics during the past decades, synchrotron‐based X‐ray microscopy techniques allow the study of specimens with unprecedented spatial resolution, down to 10 nm, using soft and medium X‐ray photon energies, though at the expense of the field of view (FOV). One of the approaches to increase the FOV to square millimetres is raster‐scanning of the specimen using a single nanoprobe; however, this results in a long data acquisition time. This work employs an array of inclined biconcave parabolic refractive multi‐lenses (RMLs), fabricated by deep X‐ray lithography and electroplating to generate a large number of long X‐ray foci. Since the FOV is limited by the pattern height if a single RML is used by impinging X‐rays parallel to the substrate, many RMLs at regular intervals in the orthogonal direction were fabricated by tilted exposure. By inclining the substrate correspondingly to the tilted exposure, 378000 X‐ray line foci were generated with a length in the centimetre range and constant intervals in the sub‐micrometre range. The capability of this new X‐ray focusing device was first confirmed using ray‐tracing simulations and then using synchrotron radiation at BL20B2 of SPring‐8, Japan. Taking account of the fact that the refractive lens is effective for focusing high‐energy X‐rays, the experiment was performed with 35 keV X‐rays. Next, by scanning a specimen through the line foci, this device was used to perform large FOV pixel super‐resolution scanning transmission hard X‐ray microscopy (PSR‐STHXM) with a 780 ± 40 nm spatial resolution within an FOV of 1.64 cm × 1.64 cm (limited by the detector area) and a total scanning time of 4 min. Biomedical implant abutments fabricated via selective laser melting using Ti–6Al–4V medical alloy were measured by PSR‐STHXM, suggesting its unique potential for studying extended and thick specimens. Although the super‐resolution function was realized in one dimension in this study, it can be expanded to two dimensions by aligning a pair of presented devices orthogonally.
    Description: A new X‐ray focusing device generates hundreds of thousands of line foci, periodically spaced in the sub‐micrometre range, with centimetre length. It enables to achieve large FOV pixel super‐resolution scanning transmission hard X‐ray microscopy. image
    Keywords: 502.82 ; inclined refractive X‐ray multi‐lens array ; pixel super‐resolution ; scanning transmission hard X‐ray microscopy ; deep X‐ray lithography and electroplating
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  • 19
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    A new concept for temporal gating of synchrotron X‐ray pulses (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-07-02
    Description: A new concept for temporal gating of synchrotron X‐ray pulses based on laser‐induced thermal transient gratings is presented. First experimental tests of the concept yield a diffraction efficiency of 0.18%; however, the calculations indicate a theoretical efficiency and contrast of 〉30% and 10−5, respectively. The full efficiency of the pulse picker has not been reached yet due to a long‐range thermal deformation of the sample after absorption of the excitation laser. This method can be implemented in a broad spectral range (100 eV to 20 keV) and is only minimally invasive to an existing setup.
    Description: A new concept for temporal gating of synchrotron X‐ray pulses based on laser‐induced thermal transient gratings is presented.
    Keywords: 548 ; synchrotron ; time‐resolved ; thermal deformation ; transient grating ; pulse picking
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    The time‐resolved hard X‐ray diffraction endstation KMC‐3 XPP at BESSY II (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-06
    Description: The time‐resolved hard X‐ray diffraction endstation KMC‐3 XPP for optical pump/X‐ray probe experiments at the electron storage ring BESSY II is dedicated to investigating the structural response of thin film samples and heterostructures after their excitation with ultrashort laser pulses and/or electric field pulses. It enables experiments with access to symmetric and asymmetric Bragg reflections via a four‐circle diffractometer and it is possible to keep the sample in high vacuum and vary the sample temperature between ∼15 K and 350 K. The femtosecond laser system permanently installed at the beamline allows for optical excitation of the sample at 1028 nm. A non‐linear optical setup enables the sample excitation also at 514 nm and 343 nm. A time‐resolution of 17 ps is achieved with the `low‐α' operation mode of the storage ring and an electronic variation of the delay between optical pump and hard X‐ray probe pulse conveniently accesses picosecond to microsecond timescales. Direct time‐resolved detection of the diffracted hard X‐ray synchrotron pulses use a gated area pixel detector or a fast point detector in single photon counting mode. The range of experiments that are reliably conducted at the endstation and that detect structural dynamics of samples excited by laser pulses or electric fields are presented.
    Description: The KMC‐3 XPP endstation of the synchrotron BESSY II is dedicated to time‐resolved studies of structural dynamics of matter upon optical and/or electrical excitation using hard X‐ray diffraction with an accessible time range from 17 ps to several microseconds. image
    Keywords: 548 ; beamline instrumentation ; time‐resolved X‐ray diffraction ; optical excitation ; thermal transport ; ferroelectric switching
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    Self‐stated recovery from flooding: Empirical results from a survey in Central Vietnam (2021)
    Blackwell Publishing Ltd | Oxford, UK
    Details
    Publication Date: 2021-06-27
    Description: Social inequalities lead to flood resilience inequalities across social groups, a topic that requires improved documentation and understanding. The objective of this paper is to attend to these differences by investigating self‐stated flood recovery across genders in Vietnam as a conceptual replication of earlier results from Germany. This study employs a regression‐based analysis of 1,010 respondents divided between a rural coastal and an urban community in Thua Thien‐Hue province. The results highlight an important set of recovery process‐related variables. The set of relevant variables is similar across genders in terms of inclusion and influence, and includes age, social capital, internal and external support after a flood, perceived severity of previous flood impacts, and the perception of stress‐resilience. However, women were affected more heavily by flooding in terms of longer recovery times, which should be accounted for in risk management. Overall, the studied variables perform similarly in Vietnam and Germany. This study, therefore, conceptually replicates previous results suggesting that women display slightly slower recovery levels as well as that psychological variables influence recovery rates more than adverse flood impacts. This provides an indication of the results' potentially robust nature due to the different socio‐environmental contexts in Germany and Vietnam.
    Keywords: 333.7 ; flood recovery ; resilience ; societal equity ; vulnerability
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  • 22
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    Disordered sodium alkoxides from powder data: crystal structures of sodium ethoxide, propoxide, butoxide and pentoxide, and some of their solvates (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-03-27
    Description: The crystal structures of sodium ethoxide (sodium ethanolate, NaOEt), sodium n‐propoxide (sodium n‐propanolate, NaOnPr), sodium n‐butoxide (sodium n‐butanolate, NaOnBu) and sodium n‐pentoxide (sodium n‐amylate, NaOnAm) were determined from powder X‐ray diffraction data. NaOEt crystallizes in space group P421m, with Z = 2, and the other alkoxides crystallize in P4/nmm, with Z = 2. To resolve space‐group ambiguities, a Bärnighausen tree was set up, and Rietveld refinements were performed with different models. In all structures, the Na and O atoms form a quadratic net, with the alkyl groups pointing outwards on both sides (anti‐PbO type). The alkyl groups are disordered. The disorder becomes even more pronounced with increasing chain length. Recrystallization from the corresponding alcohols yielded four sodium alkoxide solvates: sodium ethoxide ethanol disolvate (NaOEt·2EtOH), sodium n‐propoxide n‐propanol disolvate (NaOnPr·2nPrOH), sodium isopropoxide isopropanol pentasolvate (NaOiPr·5iPrOH) and sodium tert‐amylate tert‐amyl alcohol monosolvate (NaOtAm·tAmOH, tAm = 2‐methyl‐2‐butyl). Their crystal structures were determined by single‐crystal X‐ray diffraction. All these solvates form chain structures consisting of Na+, –O− and –OH groups, encased by alkyl groups. The hydrogen‐bond networks diverge widely among the solvate structures. The hydrogen‐bond topology of the iPrOH network in NaOiPr·5iPrOH shows branched hydrogen bonds and differs considerably from the networks in pure crystalline iPrOH.
    Description: The crystal structures of NaOEt, NaOPr, NaOBu and NaOAm (Am = amyl = pentyl) were determined from powder data. These compounds crystallize in an anti‐PbO structure in the space groups P21m and P4/nmm. Additionally, solvates with the composition NaOEt·2EtOH, NaOPr·2PrOH, NaOiPr·5iPrOH and NaOtAm·tAmOH were synthesized, and their structures were determined from single crystals. They form interesting chain structures of different compositions and topologies. image
    Keywords: 548 ; sodium alkoxide ; powder data ; solvate ; isopropanol ; Bärnighausen tree ; PXRD
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  • 23
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    The potential of ryegrass as cover crop to reduce soil N2O emissions and increase the population size of denitrifying bacteria (2021)
    Blackwell Publishing Ltd | Oxford, UK
    Details
    Publication Date: 2021-07-05
    Description: Nitrogen (N) fertilization is the major contributor to nitrous oxide (N2O) emissions from agricultural soil, especially in post‐harvest seasons. This study was carried out to investigate whether ryegrass serving as cover crop affects soil N2O emissions and denitrifier community size. A microcosm experiment was conducted with soil planted with perennial ryegrass (Lolium perenne L.) and bare soil, each with four levels of N fertilizer (0, 5, 10 and 20 g N m−2; applied as calcium ammonium nitrate). The closed‐chamber approach was used to measure soil N2O fluxes. Real‐time PCR was used to estimate the biomass of bacteria and fungi and the abundance of genes involved in denitrification in soil. The results showed that the presence of ryegrass decreased the nitrate content in soil. Cumulative N2O emissions of soil with grass were lower than in bare soil at 5 and 10 g N m−2. Fertilization levels did not affect the abundance of soil bacteria and fungi. Soil with grass showed greater abundances of bacteria and fungi, as well as microorganisms carrying narG, napA, nirK, nirS and nosZ clade I genes. It is concluded that ryegrass serving as a cover crop holds the potential to mitigate soil N2O emissions in soils with moderate or high NO3− concentrations. This highlights the importance of cover crops for the reduction of N2O emissions from soil, particularly following N fertilization. Future research should explore the full potential of ryegrass to reduce soil N2O emissions under field conditions as well as in different soils. Highlights This study was to investigate whether ryegrass serving as cover crop affects soil N2O emissions and denitrifier community size; Plant reduced soil N substrates on one side, but their root exudates stimulated denitrification on the other side; N2O emissions were lower in soil with grass than bare soil at medium fertilizer levels, and growing grass stimulated the proliferation of almost all the denitrifying bacteria except nosZ clade II; Ryegrass serving as a cover crop holds the potential to mitigate soil N2O emissions.
    Description: China Scholarship Council http://dx.doi.org/10.13039/501100004543
    Description: The National Science Project for University of Anhui Province
    Keywords: 551.9 ; 631.4 ; denitrification ; perennial ryegrass (Lolium perenne L.) ; soil bacteria ; soil CO2 emissions ; soil N2O emissions
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  • 24
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    Small‐angle X‐ray scattering from GaN nanowires on Si(111): facet truncation rods, facet roughness and Porod's law (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-03-27
    Description: Small‐angle X‐ray scattering from GaN nanowires grown on Si(111) is measured in the grazing‐incidence geometry and modelled by means of a Monte Carlo simulation that takes into account the orientational distribution of the faceted nanowires and the roughness of their side facets. It is found that the scattering intensity at large wavevectors does not follow Porod's law I(q) ∝ q−4. The intensity depends on the orientation of the side facets with respect to the incident X‐ray beam. It is maximum when the scattering vector is directed along a facet normal, reminiscent of surface truncation rod scattering. At large wavevectors q, the scattering intensity is reduced by surface roughness. A root‐mean‐square roughness of 0.9 nm, which is the height of just 3–4 atomic steps per micrometre‐long facet, already gives rise to a strong intensity reduction.
    Description: The intensity of small‐angle X‐ray scattering from GaN nanowires on Si(111) depends on the orientation of the side facets with respect to the incident beam. This reminiscence of truncation rod scattering gives rise to a deviation from Porod's law. A roughness of just 3–4 atomic steps per micrometre‐long side facet notably changes the intensity curves. image
    Keywords: 548 ; nanowires ; Porod's law ; facet truncation rods ; small‐angle X‐ray scattering ; SAXS ; grazing‐incidence small‐angle X‐ray scattering ; GISAXS
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    The accuracy of protein models automatically built into cryo‐EM maps with ARP/wARP (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-28
    Description: Recent developments in cryogenic electron microscopy (cryo‐EM) have enabled structural studies of large macromolecular complexes at resolutions previously only attainable using macromolecular crystallography. Although a number of methods can already assist in de novo building of models into high‐resolution cryo‐EM maps, automated and reliable map interpretation remains a challenge. Presented here is a systematic study of the accuracy of models built into cryo‐EM maps using ARP/wARP. It is demonstrated that the local resolution is a good indicator of map interpretability, and for the majority of the test cases ARP/wARP correctly builds 90% of main‐chain fragments in regions where the local resolution is 4.0 Å or better. It is also demonstrated that the coordinate accuracy for models built into cryo‐EM maps is comparable to that of X‐ray crystallographic models at similar local cryo‐EM and crystallographic resolutions. The model accuracy also correlates with the refined atomic displacement parameters.
    Keywords: 548 ; ARP/wARP ; model building ; cryo‐EM ; model accuracy ; sequence assignment
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    Synthesis, crystal structure and structure–property relations of strontium orthocarbonate, Sr2CO4 (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
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    Publication Date: 2021-06-05
    Description: Carbonates containing CO4 groups as building blocks have recently been discovered. A new orthocarbonate, Sr2CO4 is synthesized at 92 GPa and at a temperature of 2500 K. Its crystal structure was determined by in situ synchrotron single‐crystal X‐ray diffraction, selecting a grain from a polycrystalline sample. Strontium orthocarbonate crystallizes in the orthorhombic crystal system (space group Pnma) with CO4, SrO9 and SrO11 polyhedra as the main building blocks. It is isostructural to Ca2CO4. DFT calculations reproduce the experimental findings very well and have, therefore, been used to predict the equation of state, Raman and IR spectra, and to assist in the discussion of bonding in this compound.
    Description: A new orthocarbonate, Sr2CO4, was synthesized under extreme pressure and temperature conditions of 92 GPa and 2500 K, respectively. The crystal structure of the compound s fully characterized in situ by synchrotron single‐crystal X‐ray diffraction and DFT calculations were employed to provide insight into its equation of state, Raman and IR spectra, and bonding. image
    Keywords: 548 ; orthocarbonates ; crystal structure ; single‐crystal X‐ray diffraction ; high pressure ; Sr2CO4
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  • 27
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    Anomalous SAXS at P12 beamline EMBL Hamburg: instrumentation and applications (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-28
    Description: Small‐angle X‐ray scattering (SAXS) is an established method for studying nanostructured systems and in particular biological macromolecules in solution. To obtain element‐specific information about the sample, anomalous SAXS (ASAXS) exploits changes of the scattering properties of selected atoms when the energy of the incident X‐rays is close to the binding energy of their electrons. While ASAXS is widely applied to condensed matter and inorganic systems, its use for biological macromolecules is challenging because of the weak anomalous effect. Biological objects are often only available in small quantities and are prone to radiation damage, which makes biological ASAXS measurements very challenging. The BioSAXS beamline P12 operated by the European Molecular Biology Laboratory (EMBL) at the PETRA III storage ring (DESY, Hamburg) is dedicated to studies of weakly scattering objects. Here, recent developments at P12 allowing for ASAXS measurements are presented. The beamline control, data acquisition and data reduction pipeline of the beamline were adapted to conduct ASAXS experiments. Modelling tools were developed to compute ASAXS patterns from atomic models, which can be used to analyze the data and to help designing appropriate data collection strategies. These developments are illustrated with ASAXS experiments on different model systems performed at the P12 beamline.
    Keywords: 548 ; ASAXS ; biological SAXS ; metalloproteins ; gold nanoparticles ; anomalous scattering ; beamline development
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    Symmetry relations in wurtzite nitrides and oxide nitrides and the curious case of Pmc21 (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-27
    Description: Binary III–V nitrides such as AlN, GaN and InN in the wurtzite‐type structure have long been considered as potent semiconducting materials because of their optoelectronic properties, amongst others. With rising concerns over the utilization of scarce elements, a replacement of the trivalent cations by others in ternary and multinary nitrides has led to the development of different variants of nitrides and oxide nitrides crystallizing in lower‐symmetry variants of wurtzite. This work presents the symmetry relationships between these structural types specific to nitrides and oxide nitrides and updates some prior work on this matter. The non‐existence of compounds crystallizing in Pmc21, formally the highest subgroup of the wurtzite type fulfilling Pauling's rules for 1:1:2 stoichiometries, has been puzzling scientists for a while; a rationalization is given, from a crystallographic basis, of why this space group is unlikely to be adopted.
    Keywords: 548 ; group–subgroup relationships ; nitride materials ; wurtzite type
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    Comparison and evaluation of pair distribution functions, using a similarity measure based on cross‐correlation functions (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-20
    Description: An approach for the comparison of pair distribution functions (PDFs) has been developed using a similarity measure based on cross‐correlation functions. The PDF is very sensitive to changes in the local structure, i.e. small deviations in the structure can cause large signal shifts and significant discrepancies between the PDFs. Therefore, a comparison based on pointwise differences (e.g. R values and difference curves) may lead to the assumption that the investigated PDFs as well as the corresponding structural models are not in agreement at all, whereas a careful visual inspection of the investigated structural models and corresponding PDFs may reveal a relatively good match. To quantify the agreement of different PDFs for those cases an alternative approach is introduced: the similarity measure based on cross‐correlation functions. In this paper, the power of this application of the similarity measure to the analysis of PDFs is highlighted. The similarity measure is compared with the classical Rwp values as representative of the comparison based on pointwise differences as well as with the Pearson product‐moment correlation coefficient, using polymorph IV of barbituric acid as an example.
    Description: A novel approach to the quantification of the agreement between pair distribution functions by a similarity measure based on cross‐correlation functions is introduced and evaluated. image
    Keywords: 548 ; pair distribution functions ; similarity measures ; total scattering techniques ; cross‐correlation functions ; R values
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    Novel experimental setup for megahertz X‐ray diffraction in a diamond anvil cell at the High Energy Density (HED) instrument of the European X‐ray Free‐Electron Laser (EuXFEL) (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-26
    Description: The high‐precision X‐ray diffraction setup for work with diamond anvil cells (DACs) in interaction chamber 2 (IC2) of the High Energy Density instrument of the European X‐ray Free‐Electron Laser is described. This includes beamline optics, sample positioning and detector systems located in the multipurpose vacuum chamber. Concepts for pump–probe X‐ray diffraction experiments in the DAC are described and their implementation demonstrated during the First User Community Assisted Commissioning experiment. X‐ray heating and diffraction of Bi under pressure, obtained using 20 fs X‐ray pulses at 17.8 keV and 2.2 MHz repetition, is illustrated through splitting of diffraction peaks, and interpreted employing finite element modeling of the sample chamber in the DAC.
    Description: The high‐precision X‐ray diffraction (XRD) setup for work with diamond anvil cells (DACs) in Interaction Chamber 2 of the High Energy Density (HED) instrument of the European X‐ray Free‐Electron Laser is described. image
    Keywords: 548 ; diamond anvil cells ; X‐ray free‐electron lasers ; high‐precision X‐ray diffraction ; finite element modeling
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    The anisotropy in the optical constants of quartz crystals for soft X‐rays (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-26
    Description: The refractive index of a y‐cut SiO2 crystal surface is reconstructed from orientation‐dependent soft X‐ray reflectometry measurements in the energy range from 45 to 620 eV. Owing to the anisotropy of the crystal structure in the (100) and (001) directions, a significant deviation of the measured reflectance at the Si L2,3 and O K absorption edges is observed. The anisotropy in the optical constants reconstructed from these data is also confirmed by ab initio Bethe–Salpeter equation calculations for the O K edge. This new experimental data set expands the existing literature data for quartz crystal optical constants significantly, particularly in the near‐edge regions.
    Description: The refractive index of a y‐cut SiO2 crystal surface is reconstructed from polarization‐dependent soft X‐ray reflectometry measurements in the energy range from 45 to 620 eV. The reconstructed anisotropy in the optical constants is also confirmed by ab initio Bethe–Salpeter equation calculations of the O K edge. image
    Keywords: 548 ; optical constants ; quartz ; anisotropy ; soft X‐ray reflectometry
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    Unravelling the crystal structure of Nd5.8WO12−δ and Nd5.7W0.75Mo0.25O12−δ mixed ionic electronic conductors (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-07-05
    Description: Mixed ionic electronic conducting ceramics Nd6−yWO12−δ (δ is the oxygen deficiency) provide excellent stability in harsh environments containing strongly reactive gases such as CO2, CO, H2, H2O or H2S. Due to this chemical stability, they are promising and cost‐efficient candidate materials for gas separation, catalytic membrane reactors and protonic ceramic fuel cell technologies. As in La6−yWO12−δ, the ionic/electronic transport mechanism in Nd6−yWO12−δ is expected to be largely controlled by the crystal structure, the conclusive determination of which is still lacking. This work presents a crystallographic study of Nd5.8WO12−δ and molybdenum‐substituted Nd5.7W0.75Mo0.25O12−δ prepared by the citrate complexation route. High‐resolution synchrotron and neutron powder diffraction data were used in combined Rietveld refinements to unravel the crystal structure of Nd5.8WO12−δ and Nd5.7W0.75Mo0.25O12−δ. Both investigated samples crystallize in a defect fluorite crystal structure with space group Fm3m and doubled unit‐cell parameter due to cation ordering. Mo replaces W at both Wyckoff sites 4a and 48h and is evenly distributed, in contrast with La6−yWO12−δ. X‐ray absorption spectroscopy as a function of partial pressure pO2 in the near‐edge regions excludes oxidation state changes of Nd (Nd3+) and W (W6+) in reducing conditions: the enhanced hydrogen permeation, i.e. ambipolar conduction, observed in Mo‐substituted Nd6−yWO12−δ is therefore explained by the higher Mo reducibility and the creation of additional – disordered – oxygen vacancies.
    Description: The crystal structures of non‐substituted and Mo‐substituted neodymium tungstates are described in detail through neutron diffraction and high‐resolution X‐ray diffraction. Combined X‐ray and neutron diffraction refinements and electron probe micro‐analysis were employed to locate Mo atoms in the crystal structure of Nd6−yW1−zMozO12−δ (z = 0, 0.25), while X‐ray absorption spectroscopy in the near‐edge regions confirmed no changes in the oxidation states of Nd and W.
    Keywords: 548 ; powder diffraction ; mixed conductors ; X‐ray absorption spectroscopy (XAS) ; Nd6−yWO12−δ
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    ogs5py: A Python‐API for the OpenGeoSys 5 Scientific Modeling Package (2021)
    Blackwell Publishing Ltd | Malden, US
    Details
    Publication Date: 2021-07-04
    Description: High‐performance numerical codes are an indispensable tool for hydrogeologists when modeling subsurface flow and transport systems. But as they are written in compiled languages, like C/C++ or Fortran, established software packages are rarely user‐friendly, limiting a wider adoption of such tools. OpenGeoSys (OGS), an open‐source, finite‐element solver for thermo‐hydro‐mechanical–chemical processes in porous and fractured media, is no exception. Graphical user interfaces may increase usability, but do so at a dramatic reduction of flexibility and are difficult or impossible to integrate into a larger workflow. Python offers an optimal trade‐off between these goals by providing a highly flexible, yet comparatively user‐friendly environment for software applications. Hence, we introduce ogs5py, a Python‐API for the OpenGeoSys 5 scientific modeling package. It provides a fully Python‐based representation of an OGS project, a large array of convenience functions for users to interact with OGS and connects OGS to the scientific and computational environment of Python.
    Description: German Federal Environmental Foundation http://dx.doi.org/10.13039/100007636
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Keywords: 551.49 ; hydrogeology ; subsurface flow ; modeling ; software
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    High‐temperature treatments of niobium under high vacuum, dilute air‐ and nitrogen‐atmospheres as investigated by in situ X‐ray absorption spectroscopy (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-30
    Description: Niobium metal foils were heat‐treated at 900°C under different conditions and in situ investigated with time‐resolved X‐ray absorption fine‐structure (EXAFS and XANES) measurements. The present study aims to mimic the conditions usually applied for heat treatments of Nb materials used for superconducting radiofrequency cavities, in order to better understand the evolving processes during vacuum annealing as well as for heat treatments in controlled dilute gases. Annealing in vacuum in a commercially available cell showed a substantial amount of oxidation, so that a designated new cell was designed and realized, allowing treatments under clean high‐vacuum conditions as well as under well controllable gas atmospheres. The experiments performed under vacuum demonstrated that the original structure of the Nb foils is preserved, while a detailed evaluation of the X‐ray absorption fine‐structure data acquired during treatments in dilute air atmospheres (10−5 mbar to 10−3 mbar) revealed a linear oxidation with the time of the treatment, and an oxidation rate proportional to the oxygen (air) pressure. The structure of the oxide appears to be very similar to that of polycrystalline NbO. The cell also permits controlled exposures to other reactive gases at elevated temperatures; here the Nb foils were exposed to dilute nitrogen atmospheres after a pre‐conditioning of the studied Nb material for one hour under high‐vacuum conditions, in order to imitate typical conditions used for nitrogen doping of cavity materials. Clear structural changes induced by the N2 exposure were found; however, no evidence for the formation of niobium nitride could be derived from the EXAFS and XANES experiments. The presented results establish the feasibility to study the structural changes of the Nb materials in situ during heat treatments in reactive gases with temporal resolution, which are important to better understand the underlaying mechanisms and the dynamics of phase formation during those heat treatments in more detail.
    Keywords: 548 ; in situ EXAFS ; high temperature ; time‐resolved EXAFS ; niobium
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    High‐Resolution Integrated Transport Model for Studying Surface Water–Groundwater Interaction (2021)
    Blackwell Publishing Ltd | Malden, US
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    Publication Date: 2021-06-27
    Description: Transport processes that lead to exchange of mass between surface water and groundwater play a significant role for the ecological functioning of aquatic systems, for hydrological processes and for biogeochemical transformations. In this study, we present a novel integral modeling approach for flow and transport at the sediment–water interface. The model allows us to simultaneously simulate turbulent surface and subsurface flow and transport with the same conceptual approach. For this purpose, a conservative transport equation was implemented to an existing approach that uses an extended version of the Navier–Stokes equations. Based on previous flume studies which investigated the spreading of a dye tracer under neutral, losing and gaining flow conditions the new solver is validated. Tracer distributions of the experiments are in close agreement with the simulations. The simulated flow paths are significantly affected by in‐ and outflowing groundwater flow. The highest velocities within the sediment are found for losing condition, which leads to shorter residence times compared to neutral and gaining conditions. The largest extent of the hyporheic exchange flow is observed under neutral condition. The new solver can be used for further examinations of cases that are not suitable for the conventional coupled models, for example, if Reynolds numbers are larger than 10. Moreover, results gained with the integral solver provide high‐resolution information on pressure and velocity distributions at the rippled streambed, which can be used to improve flow predictions. This includes the extent of hyporheic exchange under varying ambient groundwater flow conditions.
    Description: Technische Universität Berlin, Germany
    Description: German Research Foundation http://dx.doi.org/10.13039/501100001659
    Keywords: 551.4 ; aquatic systems ; sediment-water interface ; transport model
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    Pressure‐induced Pb–Pb bonding and phase transition in Pb2SnO4 (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-03-27
    Description: High‐pressure single‐crystal to 20 GPa and powder diffraction measurements to 50 GPa, show that the structure of Pb2SnO4 strongly distorts on compression with an elongation of one axis. A structural phase transition occurs between 10 GPa and 12 GPa, with a change of space group from Pbam to Pnam. The resistivity decreases by more than six orders of magnitude when pressure is increased from ambient conditions to 50 GPa. This insulator‐to‐semiconductor transition is accompanied by a reversible appearance change from transparent to opaque. Density functional theory‐based calculations show that at ambient conditions the channels in the structure host the stereochemically‐active Pb 6s2 lone electron pairs. On compression the lone electron pairs form bonds between Pb2+ ions. Also provided is an assignment of irreducible representations to the experimentally observed Raman bands.
    Description: The structure of Pb2SnO4 is found to strongly distort on compression and a structural phase transition with a change of space group from Pbam to Pnam occurs at ∼11 GPa. Our complementary DFT‐based calculations show that at ambient conditions, the channels in the structure host the stereochemically active Pb 6s2 lone electron pairs which form bonds between the Pb2+ ions with increasing pressure. image
    Keywords: 548 ; lead stannate (Pb2SnO4) ; density functional theory ; high‐pressure X‐ray diffraction ; pressure‐induced phase transition ; insulator–semiconductor transition
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    Iron isotope fractionation in soil and graminaceous crops after 100 years of liming in the long‐term agricultural experimental site at Berlin‐Dahlem, Germany (2021)
    Blackwell Publishing Ltd | Oxford, UK
    Details
    Publication Date: 2021-07-05
    Description: Sustainable arable cropping relies on repeated liming. Yet, the associated increase in soil pH can reduce the availability of iron (Fe) to plants. We hypothesized that repeated liming, but not pedogenic processes such as lessivage (i.e., translocation of clay particles), alters the Fe cycle in Luvisol soil, thereby affecting Fe isotope composition in soils and crops. Hence, we analysed Fe concentrations and isotope compositions in soil profiles and winter rye from the long‐term agricultural experimental site in Berlin‐Dahlem, Germany, where a controlled liming trial with three field replicates per treatment has been conducted on Albic Luvisols since 1923. Heterogeneity in subsoil was observed at this site for Fe concentration but not for Fe isotope composition. Lessivage had not affected Fe isotope composition in the soil profiles. The results also showed that almost 100 years of liming lowered the concentration of the HCl‐extractable Fe that was potentially available for plant uptake in the surface soil (0–15 cm) from 1.03 (standard error (SE) 0.03) to 0.94 (SE 0.01) g kg−1. This HCl‐extractable Fe pool contained isotopically lighter Fe (δ56Fe = −0.05 to −0.29‰) than the bulk soil (δ56Fe = −0.08 to 0.08‰). However, its Fe isotope composition was not altered by the long‐term lime application. Liming resulted in relatively lower Fe concentrations in the roots of winter rye. In addition, liming led to a heavier Fe isotope composition of the whole plants compared with those grown in the non‐limed plots (δ56FeWholePlant_ + Lime = −0.12‰, SE 0.03 vs. δ56FeWholePlant_‐Lime = −0.21‰, SE 0.01). This suggests that the elevated soil pH (increased by one unit due to liming) promoted the Fe uptake strategy through complexation of Fe(III) from the rhizosphere, which favoured heavier Fe isotopes. Overall, the present study showed that liming and a related increase in pH did not affect the Fe isotope compositions of the soil, but may influence the Fe isotope composition of plants grown in the soil if they alter their Fe uptake strategy upon the change of Fe availability. Highlights Fe concentrations and stocks, but not Fe isotope compositions, were more heterogeneous in subsoil than in topsoil. Translocation of clay minerals did not result in Fe isotope fractionation in the soil profile of a Luvisol. Liming decreased Fe availability in topsoil, but did not affect its δ56Fe values. Uptake of heavier Fe isotopes by graminaceous crops was more pronounced at elevated pH.
    Description: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Keywords: 551.9 ; liming ; plant‐available Fe pool in soil ; winter rye ; δ56Fe
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  • 38
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    A discussion on `Domain formation and phase transitions in the wurtzite‐based heterovalent ternaries: a Landau theory analysis' (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-05
    Description: Heterovalent ternary nitrides are considered one of the promising classes of materials for photovoltaics, combining attractive physical properties with low toxicity and element abundance. One of the front‐runner systems under consideration is ZnSnN2. Although it is nominally a ternary compound, no clear crystallographic evidence for cation ordering has been observed so far. An attempt to elucidate this discrepancy [Quayle (2020). Acta Cryst. A76, 410–420] was the trigger for an intensive discussion between the authors, and an agreement was reached to elaborate on some points in order to set things in perspective. Rather than using a conventional comment–answer scheme, this is published in the form of a joint discussion to celebrate constructive criticism and collegiality.
    Description: A scientific exchange on an earlier paper [Quayle (2020). Acta Cryst. A76, 410–420] has led to the clarification of some of the points. image
    Keywords: 548 ; group–subgroup relationships ; nitride materials ; wurtzite type
    Type: article
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  • 39
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    Unknown
    X‐SPEC: a 70 eV to 15 keV undulator beamline for X‐ray and electron spectroscopies (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-26
    Description: X‐SPEC is a high‐flux spectroscopy beamline at the KIT (Karlsruhe Institute of Technology) Synchrotron for electron and X‐ray spectroscopy featuring a wide photon energy range. The beamline is equipped with a permanent magnet undulator with two magnetic structures of different period lengths, a focusing variable‐line‐space plane‐grating monochromator, a double‐crystal monochromator and three Kirkpatrick–Baez mirror pairs. By selectively moving these elements in or out of the beam, X‐SPEC is capable of covering an energy range from 70 eV up to 15 keV. The flux of the beamline is maximized by optimizing the magnetic design of the undulator, minimizing the number of optical elements and optimizing their parameters. The beam can be focused into two experimental stations while maintaining the same spot position throughout the entire energy range. The first experimental station is optimized for measuring solid samples under ultra‐high‐vacuum conditions, while the second experimental station allows in situ and operando studies under ambient conditions. Measurement techniques include X‐ray absorption spectroscopy (XAS), extended X‐ray absorption fine structure (EXAFS), photoelectron spectroscopy (PES) and hard X‐ray PES (HAXPES), as well as X‐ray emission spectroscopy (XES) and resonant inelastic X‐ray scattering (RIXS).
    Description: X‐SPEC is a high‐flux undulator beamline for electron and X‐ray spectroscopy with an energy range from 70 eV to 15 keV. It offers X‐ray absorption spectroscopy (XAS), extended X‐ray absorption fine structure (EXAFS), photoelectron spectroscopy (PES) and hard X‐ray PES (HAXPES), as well as X‐ray emission spectroscopy (XES) and resonant inelastic X‐ray scattering (RIXS) for in vacuo, in situ and operando sample environments. image
    Keywords: 548 ; undulator beamline ; soft X‐ray ; tender X‐ray ; hard X‐ray ; in situ ; operando ; HAXPES ; RIXS ; XAS ; XES
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  • 40
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    Structure determination of organic compounds by a fit to the pair distribution function from scratch without prior indexing (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-06-26
    Description: A method for the ab initio crystal structure determination of organic compounds by a fit to the pair distribution function (PDF), without prior knowledge of lattice parameters and space group, has been developed. The method is called `PDF‐Global‐Fit' and is implemented by extension of the program FIDEL (fit with deviating lattice parameters). The structure solution is based on a global optimization approach starting from random structural models in selected space groups. No prior indexing of the powder data is needed. The new method requires only the molecular geometry and a carefully determined PDF. The generated random structures are compared with the experimental PDF and ranked by a similarity measure based on cross‐correlation functions. The most promising structure candidates are fitted to the experimental PDF data using a restricted simulated annealing structure solution approach within the program TOPAS, followed by a structure refinement against the PDF to identify the correct crystal structure. With the PDF‐Global‐Fit it is possible to determine the local structure of crystalline and disordered organic materials, as well as to determine the local structure of unindexable powder patterns, such as nanocrystalline samples, by a fit to the PDF. The success of the method is demonstrated using barbituric acid as an example. The crystal structure of barbituric acid form IV solved and refined by the PDF‐Global‐Fit is in excellent agreement with the published crystal structure data.
    Keywords: 548 ; pair distribution function analysis ; structure determination ; total scattering technique ; similarity measures ; PDF‐Global‐Fit
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  • 41
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    Structural basis of chitin utilization by a GH20 β‐N‐acetylglucosaminidase from Vibrio campbellii strain ATCC BAA‐1116 (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-07-01
    Description: Vibrio species play a crucial role in maintaining the carbon and nitrogen balance between the oceans and the land through their ability to employ chitin as a sole source of energy. This study describes the structural basis for the action of the GH20 β‐N‐acetylglucosaminidase (VhGlcNAcase) in chitin metabolism by Vibrio campbellii (formerly V. harveyi) strain ATCC BAA‐1116. Crystal structures of wild‐type VhGlcNAcase in the absence and presence of the sugar ligand, and of the unliganded D437A mutant, were determined. VhGlcNAcase contains three distinct domains: an N‐terminal carbohydrate‐binding domain linked to a small α+β domain and a C‐terminal (β/α)8 catalytic domain. The active site of VhGlcNAcase has a narrow, shallow pocket that is suitable for accommodating a small chitooligosaccharide. VhGlcNAcase is a monomeric enzyme of 74 kDa, but its crystal structures show two molecules of enzyme per asymmetric unit, in which Gln16 at the dimeric interface of the first molecule partially blocks the entrance to the active site of the neighboring molecule. The GlcNAc unit observed in subsite −1 makes exclusive hydrogen bonds to the conserved residues Arg274, Tyr530, Asp532 and Glu584, while Trp487, Trp546, Trp582 and Trp505 form a hydrophobic wall around the −1 GlcNAc. The catalytic mutants D437A/N and E438A/Q exhibited a drastic loss of GlcNAcase activity, confirming the catalytic role of the acidic pair (Asp437–Glu438).
    Description: Crystal structures of a GH20 β‐N‐acetylglucosaminidase from V. campbellii reveal substrate specificity in chitin utilization.
    Keywords: 577.14 ; GH20 β‐N‐acetylglucosaminidase ; chitin recycling ; Vibrio spp ; marine bacteria
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  • 42
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    Resolution of a bent‐crystal spectrometer for X‐ray free‐electron laser pulses: diamond versus silicon (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-09-29
    Description: The resolution function of a spectrometer based on a strongly bent single crystal (bending radius of 10 cm or less) is evaluated. It is shown that the resolution is controlled by two parameters: (i) the ratio of the lattice spacing of the chosen reflection to the crystal thickness and (ii) a single parameter comprising crystal thickness, its bending radius, distance to a detector, and anisotropic elastic constants of the chosen crystal. The results allow the optimization of the parameters of bent‐crystal spectrometers for the hard X‐ray free‐electron laser sources.
    Description: The resolution function of a bent‐crystal spectrometer for pulses of an X‐ray free‐electron laser is evaluated. Under appropriate conditions, the energy resolution reaches the ratio of the lattice spacing to the crystal thickness. image
    Keywords: 548 ; X‐ray free‐electron lasers ; X‐ray spectroscopy ; bent crystals ; diamond crystal optics ; femtosecond X‐ray diffraction
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  • 43
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    Separation of the inelastic and elastic scattering in time‐of‐flight mode on the pinhole small‐angle neutron scattering diffractometer KWS‐2 (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-09-29
    Description: To study and control the incoherent inelastic background in small‐angle neutron scattering, which makes a significant contribution to the detected scattering from hydrocarbon systems, the KWS‐2 small‐angle neutron scattering diffractometer operated by the Jülich Centre for Neutron Science (JCNS) at Heinz‐Maier Leibnitz Zentrum (MLZ), Garching, Germany, was equipped with a secondary single‐disc chopper that is placed in front of the sample stage. This makes it possible to record in time‐of‐flight mode the scattered neutrons in the high‐Q regime of the instrument (i.e. short incoming wavelengths and detection distances) and to discard the inelastic component from the measured data. Examples of measurements on different materials routinely used as standard samples, sample containers and solvents in the experiments at KWS‐2 are presented. When only the elastic region of the spectrum is used in the data‐reduction procedure, a decrease of up to two times in the incoherent background of the experimentally measured scattering cross section may be obtained. The proof of principle is demonstrated on a solution of bovine serum albumin in D2O.
    Description: A new chopper has been installed at the sample position in front of the sample stage at the KWS‐2 small‐angle neutron‐scattering diffractometer of the Jülich Centre for Neutron Science. The pulsed beam and the time‐of‐flight data acquisition enable the separation of elastic and inelastic scattering from hydrogenous samples.
    Keywords: 548 ; TOF‐SANS ; incoherent neutron scattering ; inelastic neutron scattering ; hydrocarbon systems
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  • 44
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    The ‘Flood Resilience Rose’: A management tool to promote transformation towards flood resilience (2021)
    Blackwell Publishing Ltd | Oxford, UK
    Details
    Publication Date: 2021-09-29
    Description: Coping with the growing impacts of flooding in EU countries, a paradigm shift in flood management can be observed, moving from safety‐based towards risk‐based approaches and holistic perspectives. Flood resilience is a common denominator of most of the approaches. In this article, we present the ‘Flood Resilience Rose’ (FRR), a management tool to promote harmonised action towards flood resilience in European regions and beyond. The FRR is a result of a two‐step process. First, based on scientific concepts as well as analysis of relevant policy documents, we identified three ‘levels of operation’. The first level refers to the EU Floods Directive and an extended multi‐layer safety approach, comprising the four different layers of protection, prevention, preparedness and recovery, and related measures to be taken. This level is not independent but depends both on the institutional (second level) and the wider (third level) context. Second, we used surveys, semi‐structured interviews and group discussions during workshops with experts from Belgium, Denmark, Germany, the Netherlands and the United Kingdom to validate the definitions and the FRR's practical relevance. The presented FRR is thus the result of rigorous theoretical and practical consideration and provides a tool capable to strengthen flood risk management practice.
    Description: European Regional Development Fund http://dx.doi.org/10.13039/501100008530
    Keywords: 551.48 ; flood defence measures ; governance and institutions ; integrated flood risk management ; resilience
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  • 45
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    Czochralski growth of mixed cubic sesquioxide crystals in the ternary system Lu2O3–Sc2O3–Y2O3 (2021)
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Details
    Publication Date: 2021-09-29
    Description: Cubic rare‐earth sesquioxide crystals are strongly demanded host materials for high power lasers, but due to their high melting points investigations on their thermodynamics and the growth of large‐size crystals of high optical quality remain a challenge. Detailed thermal investigations of the ternary system Lu2O3–Sc2O3–Y2O3 revealing a large range of compositions with melting temperatures below 2200°C and a minimum of 2053°C for the composition (Sc0.45Y0.55)2O3 are presented. These reduced temperatures enable for the first time the growth of high optical quality mixed sesquioxide crystals with disordered structure by the conventional Czochralski method from iridium crucibles. An (Er0.07Sc0.50Y0.43)2O3 crystal is successfully grown and characterized with respect to its crystallographic properties as well as its composition, thermal conductivity and optical absorption in the 1 µm range.
    Description: The phase diagram of the ternary system Lu2O3–Sc2O3–Y2O3 is investigated and compositions with melting points below 2200°C are found. This allows for the first successful growth of the mixed cubic sesquioxide crystal (Er0.07Sc0.50Y0.43)2O3 by the Czochralski method from an iridium crucible. image
    Keywords: 548 ; crystal growth ; optical materials ; phase diagrams ; melting points ; rare earth sesquioxides
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  • 46
    Electronic Resource
    Electronic Resource
    REVIEW OF METHODS OF INDEPENDENT MODEL AERIAL TRIANGULATION (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Notes: This paper gives a summary of the methods that have been used for independent model aerial triangulation. A modification of one of the methods is proposed and the paper concludes with a comparison of the independent model with the classical method of triangulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00401.x
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  • 47
    Electronic Resource
    Electronic Resource
    PHOTOGRAMMETRY ROUND THE WORLD (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00406.x
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  • 48
    Electronic Resource
    Electronic Resource
    Scale-Compensation Stereoscope (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00409.x
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  • 49
    Electronic Resource
    Electronic Resource
    EDITORIAL (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00389.x
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  • 50
    Electronic Resource
    Electronic Resource
    THE WILLIAMSON F49 MARK 4 AIR SURVEY CAMERA (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Notes: The camera is a further development of an existing type with greatly improved photogrammetric performance so that the photography can be used with first-order plotting machines. A new lens provides minimal distortion, high resolution and greatly improved marginal illumination. An entirely new shutter provides high speeds and efficiency. Laboratory results and preliminary survey trials indicate image quality and location standards of the same order as established existing cameras.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00392.x
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  • 51
    Electronic Resource
    Electronic Resource
    BOOK REVIEWS (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Book reviews in this article:INTERNATIONAL YEAR BOOK OF CARTOGRAPHY (Vol. IV, 1964). Editor, Eduard Imhof.JUBILEE VOLUME DEDICATED TO WILLEM SCHERMERHORN ON HIS SEVENTIETH ANNIVERSARY: ESSAYS ON THE DEVELOPMENT OF PHOTOGRAMMETRY. Published by I.T.C., Delft.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00396.x
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  • 52
    Electronic Resource
    Electronic Resource
    PHOTOGRAMMETRY APPLIED TO PIPE SYSTEMS OF CHEMICAL PLANT (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Notes: A successful attempt has been made to produce design plans of large chemical plant using photogrammetric techniques, and involving the development and modification of cameras and plotting equipment. Photogrammetry has provided a solution to a problem which could not easily be solved by direct methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00403.x
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  • 53
    Electronic Resource
    Electronic Resource
    BOOK REVIEW (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
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    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Book reviews in this article:PROCEEDINGS OF THE SECOND NATIONAL CONFERENCE OF SOUTH AFRICAN SURVEYORS, FEBRUARY 1964. Edited by G. H. Menzies et al.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00407.x
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  • 54
    Electronic Resource
    Electronic Resource
    IMPRESSIONS OF LISBON (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
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    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Four authors review the activities of the seven Commissions of the I.S.P. at the Xth International Congress, Lisbon, 1964.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00390.x
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  • 55
    Electronic Resource
    Electronic Resource
    PHOTOGRAMMETRY ROUND THE WORLD (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00394.x
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  • 56
    Electronic Resource
    Electronic Resource
    INTERNATIONAL BIBLIOGRAPHY OF PHOTOGRAMMETRY (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00395.x
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  • 57
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    Electronic Resource
    OBITUARY (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
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    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00399.x
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  • 58
    Electronic Resource
    Electronic Resource
    SWEDISH TEST FIELDS FOR AERIAL PHOTOGRAPHS (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
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    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Rather than rely on laboratory calibration, test fields have been established in Sweden to enable photography from a tower or aircraft, and so simulate as nearly as possible actual operational conditions. Repeated experiments, followed by analysis of photography, and the application of statistical tests, have allowed the geometrical quality of the aerial photograph to be assessed, and systematic and irregular errors to be distinguished.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00402.x
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  • 59
    Electronic Resource
    Electronic Resource
    THE EXPLICIT SOLUTION OF THE SINGLE PICTURE RESECTION PROBLEM, WITH A LEAST SQUARES ADJUSTMENT TO REDUNDANT CONTROL (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Notes: It does not seem to be widely recognised that the solution of the space resection problem from measurements made on a single photograph of three ground control points is not unique. There are, in general, four solutions, so that either the camera orientation must be approximately known (as is the case for near vertical photography) or extra control must be used to discriminate between these solutions. The iterative solution commonly used will only yield one solution, which will be correct if the photography is nearly vertical, but which is liable to be wrong in the general case. An explicit solution is therefore preferred since all solutions may be examined in the light of such extra control as is available. This paper gives a method for such a solution and shows how the discrimination should be used. The paper goes on to derive a method of adjusting the result to redundant control by least squares.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00404.x
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  • 60
    Electronic Resource
    Electronic Resource
    ANNUAL GENERAL MEETING, 1964 (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
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    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00393.x
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  • 61
    Electronic Resource
    Electronic Resource
    Availability of Aerial Photographs (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    Details
    ISSN: 1477-9730
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Architecture, Civil Engineering, Surveying
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1477-9730.1965.tb00397.x
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  • 62
    Electronic Resource
    Electronic Resource
    Comparative Studies on Spirostomum: Silver Impregnation of Three Species (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Silver impregnation techniques were used to study the silverline system of three species in the genus Spirostomum. It was concluded that for those species studied in the general area of Washington, D.C., the average numbers of ciliary meridians in S. teres, S. minus and S. ambiguum are 18, 24 and 46 respectively. Seventy-six % of the measurements in S. teres and S. ambiguum and 84% of the measurements in S. minus deviate from the mean by less than 1 standard deviation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03261.x
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  • 63
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    Blepharisma seculum, sp. nov., a Member of the Subgenus (Compactum) (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Blepharisma seculum sp. nov. is described as a small-sized blepharisma with a compact, spheroid macronucleus and a distinct curvature of the body anteriorly. A comparison of this form with other species of the genus Blepharisma subgenus (Compactum) is given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03264.x
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    Lymphotropha tribolii gen. nov., sp. nov., Neogregarinida, Schizocystidae, from the Haemocoele of Tribolium castaneum (Herbst) (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Lymphotropha tribolii gen. nov., sp. nov. (Neogregarinida, Schizocystidae) is described from the haemocoele of Tribolium castaneum (Herbst) (Coleoptera, Tenebrionidae). The trophozoites are large, ovoid and uninucleate with distinct longitudinal striae. Schizogony occurs in one type of cycle only, each schizont giving rise to up to 8 merozoites. Gametocytes are uninucleate when they associate. Up to 16 oocysts each with 8 sporozoites are formed in each gametocyst. The oocysts are lemon-shaped, and sporozoites emerge from the poles.The parasite causes considerable mortality in young larvae, though its pathogenicity is probably inferior to that of Farinocystis tribolii Weiser.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03263.x
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  • 65
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    Sarcocystis garnhami n. sp. in the Skeletal Muscle of an Opossum, Didelphis marsupialis (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Sarcocystis garnhami n. sp. is described from an opossum, Didelphis marsupialis. Its distinguishing characters are the spiny cyst wall, 6–8 μ thick, and the size of the spores, 5.3–6.9 μ in length and 1.3–1.9 μ in breadth. Sarcocystis darlingi, Brumpt 1913 is considered Besnoitia darlingi (Brumpt, 1913) n. comb.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03262.x
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  • 66
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    Paracineta sp., an Epizoic Suctorian Found on Gulf of Maine Copepoda (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. An epizoic suctorian from Gulf of Maine coastal waters, designated as Paracineta sp., is described. Morphological measurements are given for 23 small, medium, and large specimens. Mean length was 200 μ and average cell body diameter 39 μ. Of 21 copepod species and 19 zooplankton groups examined, only copepods of the genus Metridia showed any Paracineta attached. Suctorian occurrence was, with a single exception, limited to adult copepods, with the larger females showing the heaviest incidence. Differences in areal occurrence were observed with greatest incidence of Paracineta on M. lucens in the eastern and central Gulf, and lowest numbers in the western area. This differential occurrence is accredited to an apparent cold water affinity of the suctorian. It is suggested that Paracineta could be carried into the Gulf during periodic intrusions of cool Nova Scotian water, reaching the western area in the southwesterly flowing Gulf of Maine eddy system. No significant differences in vertical distribution were found in Paracineta incidence on Metridia among the depths sampled (0, 10, 30, and 60 m). No harmful effect of Paracineta on Metridia was evident.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03265.x
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  • 67
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    Cultivation of Three Species of Theileria in Lymphoid Cells in vitro (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. The intralymphocytic stages of Theileria parva, T. lawrencei and T. annulata have been cultivated for several months in tissue cultures of bovine lymphocytes associated with baby hamster kidney cells. In established cultures the theilerial particles multiplied at about the same rate as the host cells, the percentage of infected cells and the mean number of parasite particles per cell remaining nearly constant.During mitotic division of the host cell the theilerial body becomes closely associated with the spindle fibres and is pulled apart and distributed to both daughter cells in late anaphase. The single theilerial particles (chromatin) within the theilerial body divide by binary fission; their division is not synchronous with that of the host cell.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03267.x
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  • 68
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    A Microbial Sulfolipid. I. Isolation and Physiological Studies (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. A sulfolipid, isolated from the phytoflagellate, Ochromonas danica, and from its medium, constitutes over 50% of the sulfur of the cells. It is bound to protein and excreted by the phytoflagellate. When the S35-labeled sulfolipid was placed in the medium it was incorporated by the cells without cleavage of the sulfate group. Thus it passes back and forth between the growth medium and the cells.The sulfolipid has been found in O. danica, O. malhamensis, Tetrahymena pyriformis, Chlamydomonas sp., Pseudomonas sp. (sea water bacterium). It was identified in the culture medium of O. danica, O. malhamensis, Chlorella pyrenoidosa, and Streptomyces griseus. Preliminary evidence was obtained for its presence in the growth medium of white clover and sorghum.
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  • 69
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    The Morphogenetic Cycle in Euplotes eurystomus and Its Bearing on Problems of Ciliate Morphogenesis (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. The normal cycle of asexual reproduction in Euplotes eurystomus was subjected to a detailed morphological study using whole-mounted and sectioned material prepared by the method of silver impregnation. The cycle was arbitrarily divided into 7 stages (numbered 0–6) characterized by nuclear and cortical events. Particular attention was focused on the development of the oral primordium (OP), and the production of new kinetal cilia (or “dorsal bristles”).The OP is interpreted as originating from an invagination or infolding of the parental cortex, followed by considerable in situ growth and differentiation beneath the cell surface. It is suggested that differentiation beneath the parental cell surface may in some way facilitate morphogenesis of other cortical structures without necessitating dedifferentiation of the parent's buccal apparatus. During stage 6, the division constriction plays an important morphogenetic role in shaping the opisthe's buccal apparatus.During stage 4, a zone of ciliary increase (ZCI) appears in the central portion of each kinety. New kinetal cilia arise as semi-circular clusters of 1 to 9 kinetosomes flanking each old basal structure; the latter persist until the new organelles are well established. An analysis of total kinetal cilia in animals during stages 0 to 3 indicates that, while ciliary number varies according to animal size, there is no increase in cilia prior to formation of the ZCI.Several aspects of the asexual cycle in Euplotes seem to bear importantly on the more general problem of ciliate morphogenesis. The pattern or gradient concept might be useful in the analysis of factors determining primordial sites, although later development of the primordium into a specific organelle or organelle system is probably controlled by autonomous epigenetic processes that are somewhat independent of the parental cortical pattern. The hypothesis of kinetosome continuity cannot account for the origin of primordial fields in cortical regions remote from pre-existing kinetosomes, as observed in Euplotes. The initiation of morphogenetic activity on the cortex is closely correlated with, and may be causally related to, the appearance of replication bands in the macronucleus. The known metabolic significance of these bands, particularly the release of nuclear RNA, lends support to this suggestion.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03266.x
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    Publication of Refresher Course, “Recent Advances in Parasitology” (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03219.x
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  • 71
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    The Effects of Heat and Cold on Cellular Development in Synchronized Tetrahymena pyriformis WH-6 (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Experiments were performed to ascertain the effect of heat and cold on oral and micronuclear development in synchronized Tetrahymena pyriformis WH-6. The developing oral primordium becomes insensitive to cold sometime during stage 2. Cold shocks cause the reversion of many stage 2 primordia to stage 1. Cells so affected are set back in division. The delayed division is always asynchronous. When heat shocks are applied prior to late stage 4, the developing primordium will regress. High temperature shocks applied at later stages permit continued development. However, when the cell begins to cleave at the high temperature, division is frequently arrested and the new oral areas regress. Subsequent cell separation is greatly delayed and asynchronous.Heat and cold affect the micronucleus in the same way. Both agents prolong the arrest of mitosis brought about by the synchronizing treatment. A temperature shock is ineffective if applied after there is a space completely separating the chromosome groups, so that mitosis is completed in the presence of the agent. Bimicronucleate chains result in those cases in which division is arrested by heat shocks.It is suggested that the different phases of sensitivity to heat and cold may reflect different types of syntheses necessary for development of the oral primordium. Division arrest and subsequent oral replacement might possibly be related to high temperature induced changes in the physical state of the ciliate cortex.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03218.x
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    Free Amino Acid Analyses of 4 Strains of Entamoeba histolytica and of E. invadens in the CLG Medium (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. The free amino acids of E. invadens and 4 strains of E. histolytica cultured in the CLG medium have been identified by thin layer chromatography. The chromatogram patterns of 3 strains grown for 72 hr at 37°C (103, K-9 and 200) were nearly identical. Amino acids detected on chromatograms according to Rf values, relative positions on chromatogram plates, and identifying colors using a polychromatic ninhydrin spray were: leucine/isoleucine, tyrosine, valine, alanine, glycine, glutamic acid, lysine/ornithine, histidine, proline, plus very small amounts of arginine and possibly serine, aspartic acid and citrulline/glutamine. Cysteic acid may also be present. The same amino acids were detected on chromatograms using comparable extracts of strain Laredo and E. invadens grown for 6 days at room temperature. However, the patterns were different in that serine, glycine, threonine and especially alanine were present in greater abundance in these latter 2 cell types.These chromatogram patterns were compared with similar analyses of strains Laredo and 200 grown in the modified Shaffer-Frye medium of Reeves.Similar analyses are reported on the basic ingredients of the CLG medium, including the cells and protoplasts of the Bacteroides, the non-multiplying bacterial associate employed in the CLG medium. The chromatogram patterns of the Bacteroides, protoplasts and medium were decidedly different from those of the amebae, thus indicating that adequate separation of bacteria, amebae and medium was accomplished.Analyses of the culture filtrates of all cells analyzed revealed a possible difference between the Laredo strain and the other strains of E. histolytica (103, K-9 and 200) in amino acid utilization. Similar differences were observed between the Laredo strain and E. invadens.
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    Announcement: American Tables Committee, Naples Zoological Station (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03221.x
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  • 74
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    Colligocineta furax Gen. Nov., Sp. Nov., an Ancistrocomid Ciliate (Holotricha: Thigmotricha) from the Sabellid Polychaete Laonome kröyeri Malmgren (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Colligocineta furax gen. nov., sp. nov., parasitizes the epithelial cells of the peristomial cirri of the sabellid polychaete Laonome kröyeri Malmgren. The material studied was dredged in West Sound of Orcas Island, San Juan Archipelago, Washington. In general, the pattern of ciliation of Colligocineta resembles that of Hypocomella and Heterocinetopsis. However, of the ten kineties which constitute the ciliary system, two from the extreme right side appear to be continuous with two from the left side. During division, the posterior part of the ciliary field is conferred upon the opisthe, and in the proter all of the ten kineties are for a time completely separate.
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    Studies on Myxosoma cartilaginis n. sp. (Protozoa: Myxosporidea) of Centrarchid Fish and a Synopsis of the Myxosoma of North American Freshwater Fishes (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Myxosoma cartilaginis n. sp. is described from the cartilage of Lepomis macrochirus (bluegill), L. cyanellus (green sunfish) and Micropterus salmoides (largemouth black bass). The development of the parasite is described from naturally infected fish which were held in spore-free water after infection. The sporoplasm invades cartilage, and becomes a multi-nucleate trophozoite which forms pansporoblasts, each of which produces 2 to 4 spores. The first spores appear in 7 weeks.The histopathology in the above fish consists at first of little cellular reaction, but after 4 to 5 months epithelioid granulomas appear around some of the spore masses. Cartilage liquefaction is present around the parasites for at least 5 weeks. Eosinophilic globules are present in cartilage cells adjacent to the lesions. Diffuse infiltration of the spores from the lesions is described.Of 24 chemicals tested for polar filament extrusion, potassium hydroxide gave the best results.An illustrated synopsis of the Myxosoma of North American fishes is given. Included is some additional information and illustrations of M. hoffmani Meglitsch, 1963. Also included is a table showing the hosts, site of infection, geographic location, spore and polar capsule sizes.
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    Morphological Studies on Holotrichous Ciliates of the Family Hysterocinetidae. II. Craticuloscuta escobari Gen. Nov., Sp. Nov., and Epicharocotyle kyburzi Gen. Nov., Sp. Nov. (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Two species of hysterocinetids occur in the alimentary tract of Drilocrius breymanni, an aquatic oligochaete collected in Departamento del Valle, Colombia. The suckers of both species are unusual for their complexity. In Craticuloscuta escobari gen. nov., sp. nov., the sucker is a shallow oval concavity with longitudinal and transverse supporting elements. About one-fifth of the area of the sucker, in its posterior portion, is ciliated, but argyrophilic punctations, which probably represent kinetosomes, are distributed in a regular pattern over most of its surface. In Epicharocotyle kyburzi gen. nov., sp. nov., the oval major portion of the sucker is deep, and continuous with a short trough which extends posteriorly and bends toward the left. Veil-like flanges, bordered by a fringe of thick, inactive cilia, arise from the margins of the sucker on either side. In the region of the trough, the flanges may overlap in such a way that the trough is almost completely covered. The trough and a small area of the major portion of the sucker anterior to it are ciliated. However, argyrophilic punctations which probably represent kinetosomes are distributed over most of the surface of the sucker. The pattern of longitudinal and transverse supporting elements found in the sucker itself extends into the flanges. In both Craticuloscuta and Epicharocotyle, the arrangement of the adoral and buccal ciliary organelles is essentially like that in Hysterocineta, Ptychostomum, and other ciliates of the family Hysterocinetidae.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03223.x
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    Staphylococcal Enterotoxin: Effect on Protozoa (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Various protozoa and lower metazoa were exposed to filtrates of Staphylococcus aureus B (formerly called Type S-6) (2) and non-enterotoxigenic filtrates of staphylococci to study the toxicity of staphylococcal enterotoxin to these organisms. No reaction specific for enterotoxin was observed either in those culture filtrates from toxin-producing strains or in solutions of purified enterotoxin. Non-specific reactions were obtained with various growth media and a “potassium inhibited” filtrate containing 0.5% K2HPO4.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03225.x
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    Effect of Hexamethonium Chloride on the Ciliary and Contractile Systems of the Ciliate Spirostomum (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. The effect of hexamethonium chloride, an acetyl-choline competitor, on the ciliary and myonemal systems of Spirostomum intermedium and S. ambiguum was investigated. Although the drug caused immobilization of the cilia, severe cell damage often ensued indicating an unspecific action. The general reaction was usually more severe and the ciliary inhibition less in S. ambiguum than in S. intermedium. It is postulated that the general reaction is the result of either membrane depolarization or binding of hexamethonium at the surface. Fed animals were more susceptible to drug action than starved ones. Raising the external potassium level did not affect the drug action.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03224.x
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    Electron Microscopy of the Ectoplasm and the Proboscis in Didinium nasutum (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. A morphological study on the ectoplasm and the proboscis in the ciliate Didinium nasutum, has been performed by means of an electron microscope. The ectoplasm and the endoplasm of Didinium are separated by a fibrous layer. In addition to the ciliary apparatus and the filament system, the ectoplasm is characterized by having ectoplasmic vacuoles enclosing cross-striated bodies and by having small rods surrounding the ciliary basal body.The filament system is composed of 4 types of tubular filaments: primary filaments originating from the basal body, secondary ones coursing longitudinally along the cell periphery, tertiary ones going down in cylindrical arrays from the periphery of the proboscis into the endoplasm, and finally kinetosomal ones from the base of the basal body into the endoplasm through the newly found pore of the fibrous layer.The fine morphology of the trichites in the proboscis is elucidated three-dimensionally and illustrated schematically. Moreover, the correlation among the small rod, ectoplasmic vacuole and trichite is discussed.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03227.x
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    A Fast-Swimming “Mutant” in Stock 51 of Paramecium aurelia, Variety 4 (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Animals arising spontaneously in a culture of Paramecium aurelia, variety 4, strain 51.8s, swam about three times as rapidly as normal 51.8s, 51.7s or 29.8 animals. When the 51-fast animals were mixed with 51.8 or 29.8 paramecia, a random sampling of swimming rates showed a bimodal distribution. The faster rate of 51-fast animals was maintained under such deleterious conditions as 48-hour starvation. “Fastness” or “slowness” could not be selected for in vegetative clones. The 51-fast paramecia would not mate with 51.7, 51.8 or 29.8 animals, although fission rate, serotype and general appearance indicated that 51-fast probably arose from strain 51.8.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03228.x
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    The Infraciliature and Argyrome of Opisthonecta henneguyi Faureé-Fremiet (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Silver stains of the free-swimming sessiline peritrich Opisthonecta henneguyi reveal the adoral infraciliature as the bases of two membranes, a haplokinety and a polykinety, which diverge at the buccal overture and spiral down the infundibulum to end at the cytostome. A second polykinety parallels the adoral polykinety in the oral half of the infundibulum, and the two form a peniculus. The haplokinety appears as a single row of kinetosomes, the adoral polykinety as a series of transverse rows of three kinetosomes. The peniculus is six kinetosomes in width.The electron microscope shows that the haplokinety is a double row of staggered kinetosomes. Only the external row bears cilia. The polykinety is a complex ciliary membrane, three kinetosomes wide. The three kinetosomes are connected with one another by fibrous bundles passing beneath them. They are linked orally and apically into longitudinal rows of thick, zig-zag, fibrous connections. The kinetosomes of the internal longitudinal row are attached by a dense fiber to a strand of fibrous material interrupted at regular intervals by dense nodes.A section of the wall of the infundibulum is thrown up into longitudinal folds with tubular fibrils running parallel to the folds. These structures, the crests, appear to continue into the cytopharynx. Beneath and around the adoral and infundibular infraciliature and the crests is a fibrous matrix with dense nodes, resembling the reticulated infundibular fiber described by Faureé-Fremiet.The trochal band in silver stains appears as short diagonal rows of kinetosomes. The electron microscope shows 5 to 7 kinetosomes per diagonal row. The kinetosomes of the diagonal rows are linked to thick dense rods which originate just above the trochal band and continue antapically past the kinetosomes for a distance of 10 to 15 μ. The kinetosomes are joined to one another by fibrous strands and each is also connected by a dense fiber to the diagonal rod to its left. Running below the kinetosomes and at right angles to the rods is a system of striated fibers.At the aboral end of the body, a ring, 2 μ in diameter, of argentophilic granules is shown by the electron microscope to be a small circle of kinetosomes. Sessile stages have not been reported for Opisthonecta. The aboral ring is probably a vestigial or non-functioning scopula.The argyrome is represented by circular striae around the body. Each stria bears argentophilic dots on either its apical or its antapical side. Electron microscopy reveals that these dots are pores in the cuticle. The striae themselves may be points of adhesion between the inner cuticle and the outer cuticle, or ridges of cytoplasm between flattened alveoli of the inner cuticle. A dense fiber runs below and parallel to each stria. Opisthonecta shows at least three different kinds of ciliary membranes. Some speculations are offered on the taxonomic affinities of peritrichs based on their infraciliature.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03226.x
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    Observations on Chytridiopsis mytilovum (Field), formerly Haplosporidium mytilovum Field, (Microsporida?) (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Haplosporidium mytilovum Field, 1924, a sporozoan (?) parasite in the ova of the mussel Mytilus edulis L., is found to be morphologically similar to, and deemed to be congeneric with, the type species of genus Chytridiopsis Schneider, C. socius S., 1884, in beetles. It is compared also with the only other reported species of Chytridiopsis in a mollusc, C. ovicola Léger and Hollande, 1917, in ova of the European oyster, Ostrea edulis L. These two parasites in ova of bivalve molluscs are much alike but, since they seem to have some slight morphological differences, it would be premature to conclude that they belong to the same species. Chytridiopsis, a genus of uncertain affinities, has been considered by various authors to be related to the Chytridiales, the Haplosporida, the Mycetozoa or the Microsporida. New evidence favors the hypothesis that it is microsporidian in nature, although proof in the form of a clearly demonstrated polar filament has not yet been produced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03229.x
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  • 83
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    Flagellate Parasites of Water Striders with a Description of Leptomonas costoris, n. sp. (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Leptomonas costoris n. sp. is described from Gerris comatus. It differs from other species of Leptomonas in the structure of the reservoir which has ultramicroscopic thickenings in its wall, matched by corresponding thickenings in the adjacent flagellar membrane. The one or two diagonal lines seen in the reservoirs of Giemsa-stained specimens are thought to be manifestations of these ultramicroscopic fibrils. The reservoir structure suggests a close relationship between this species and Cryptobia, (family Bodonidae) in which somewhat similar structures have been described. Blastocrithidia veliae is redescribed and differentiated from B. gerridis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03230.x
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  • 84
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    Glucose-6-phosphate Dehydrogenase and Reduced Glutathione in Malaria-Infected Erythrocytes (Plasmodium lophurae and P. berghei (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Glucose-6-phosphate dehydrogenase activity and the level of reduced glutathione were assayed in host-parasite interactions in which the malaria parasites preferentially invade: 1. mature erythrocytes (Plasmodium lophurae in the duck) and 2. reticulocytes (P. berghei in the mouse). Assay for glucose-6-phosphate dehydrogenase was by the dye decolorization test of Motulsky and Campbell. In P. berghei infected mouse erythrocytes with parasitemias ranging from 28–78% there was no deficiency in enzyme except at the 78% level. Similarly, P. lophurae-infected duck erythrocytes with parasitemias of 29–114% showed no enzyme deficiency except above the 80% level. No linear relationship existed between parasitemia and enzyme level. The reduced glutathione stability test of Beutler in duck erythrocytes infected with P. lophurae in the range 27–67% showed no glutathione instability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03231.x
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  • 85
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    The Isolation and Identification of Kinetosome-Rich Fractions from Tetrahymena pyriformis (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Axenic cultures of Tetrahymena pyriformis W were used to obtain fractions rich in kinetosomes by alcoholdigitonin extraction techniques followed by centrifugation. The morphology of the kinetosomes was examined in the electron microscope at various stages during the isolation procedure, and compared to the morphology of the in situ kinetosome. In the latter preparation the well known cartwheel structure was present, and in addition 9 electron dense dots were displayed at the end of each spoke of the cartwheel.The prepared kinetosomes could easily be identified during the entire process, and there was no apparent change until after the digitonin step. However, with the further fractionation, alteration was found to have taken place in the interior and in the kinetosome wall. The inside appeared “empty,” and we were not able to find 9 triplets in the wall but only doublets.In view of the morphological alterations in the kinetosomerich fractions, chemical analysis still appears to us to be premature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03232.x
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  • 86
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    Excystment of Didinium nasutum (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Excystment of Didinium nasutum is solely dependent upon dense bacterial populations and is independent of the type of medium in which the bacteria have been grown. Beers' hypothesis of the need for a factor from proteose-peptone is thereby not confirmed, but the need for living, intact bacteria as postulated by him is fully shown. The process of excystment is initiated by bacteria, but their presence is not required throughout the excystment. Axenically grown paramecia, shown to be adequate as food organisms for didinia, will not induce excystment. Five types of bacteria including Gram-positive, Gram-negative, aerobic and anaerobic all suffice to induce excystment, suggesting that the initiation of this process is caused by some general metabolic process or product of bacteria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03234.x
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  • 87
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    Differences in Mitochondrial Fine Structure During Mitosis in Amoebae (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. About 50% of the amoebae found in early prophase through metaphase stages of mitosis have at least some mitochondria (ca. 25%) that contain complex internal structural patterns. These patterns are less frequently seen in mitochondria after metaphase, and they are extremely rare or absent during interphase. In the most typical pattern, larger than normal tubules are arranged in a parallel zig-zag configuration with a small amount of matrix between them. Complex patterns typically comprise about 30% of the mitochondrion; they are usually confined to one area, the remaining portion consisting of a clear matrix with few, if any, peripheral tubules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03235.x
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  • 88
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    Eimeria tuscarorensis n. sp. (Protozoa: Eimeriidae) and Redescriptions of Other Coccidia of the Woodchuck, Marmota monax (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Examination of feces obtained from wild-trapped woodchucks, Marmota monax, near Chambersburg, Pennsylvania, revealed three previously described species: Eimeria monacis, E. perforoides, and E. os. In addition I found a new coccidium, E. tuscarorensis n. sp., described in this paper. Structurally the new species resembles E. wisconsinensis and E. bilamellata. An unidentified polysporocystic coccidium, possibly the genus Klossia, was found in small numbers in one sample.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03236.x
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  • 89
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    Mattesia grandis n. sp., a Sporozoan Pathogen of the Boll Weevil, Anthonomus grandis Boheman (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Laboratory cultures of the boll weevil, Anthonomus grandis Boheman, became infected with Mattesia grandis n. sp. (Neogregarinida, Ophryocystidae). The ensuing epizootic resulted in destruction of the weevil colony. Infection occurred per os in larval and adult weevils. Sporozoites penetrate the intestinal wall and infect adipose tissue cells. Micronuclear schizogony with production of merozoites is the primary method of multiplication and spread to new foci. Micronuclear schizonts may grow as large as 30 μ in size and produce up to 200 or so merozoites, which may be 20 μ long and 1–2.5 μ wide and are motile. Macronuclear schizonts are formed from these 1st schizogony merozoites, and can become 20–30 μ in size, producing up to 80 or so macronuclear merozoites. These can be 15 μ long but 2–3 μ wide with limited motility. Second schizogony merozoites form gamonts, which pair, forming gametocysts. Nuclear division occurs, resulting in 4 equal sized nuclei and 2 pairs of residual nuclei. Four gametes are formed by cytoplasmic constriction around the nuclei. The gametes rapidly pair to form 2 zygotes in the gametocyst, resulting in 2 spores. Nuclear pairing in 1 of the 2 zygotes often lags slightly behind. Abnormal development of zygotes was rare, but could result in 1 spore with 3 poles and a normal spore, or with only 1 spore developing. Near maturity gametocysts are about 12.5 μ long and 14.0 μ wide, with the gametocyst wall tightly stretched over the poles of the spores. Spores often are slightly flattened on the adjacent side in the gametocyst but frequently attained evenly curved walls on all sides after release. The spores are octozoic, with sporozoite development occurring after release from the gametocyst. Spores measured 7.1 μ X 11.8 μ. Characters are given to separate M. grandis from other species of Mattesia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03233.x
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  • 90
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    Nosema muris n. sp., a New Microsporidian Parasite of the White Mouse (Mus musculus L.) (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. A microsporidian, Nosema muris n. sp., is described from laboratory white mice in Czechoslovakia. I t differs from Nosema cuniculi (Levaditi, Nicolau and Schoen, 1923) and other Microsporidia in mice in that it develops in the omentum and heart muscle, iorming large masses of schizonts and spores. The parasite is distributed to other tissues (liver, spleen, fat, peritoneal muscles, connective tissue and brain) by infected mononudear cells, and then forms localized cysts in them. Kidney, lungs, adrenal glands, pancreas and salivary glands are not infected. The parasite can be transmitted via the placenta, by feeding on infected tissues, or by experimental injection of ascitic fluid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb01816.x
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  • 91
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    Further Observations on the Initial Development of Infections with Babesia bigemina (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Babesia bigemina was identified in the erythrocytes of calves as early as 9 days 21 hours after infected larval ticks (Boophilus microplus) had been placed on them. This confirms the circumstantial data [Hoyte, (1961): J. Protozool. 8, 462–61, which indicated that there is no pre-erythrocytic schizogony in the life cycle of B. bigemina.The earliest time at which parasites were themselves found to be capable of infecting ticks was between 11 and 12 days, (i.e., about two days after parasites were first seen in the blood). It is suggested that this delay occurs because, until this time, parasites are present in the blood in such small numbers that none survive digestion within the tick.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb01817.x
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  • 92
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    Morphological Comparison of Diophrys scutum (Dujardin, 1841) and Diophrys peloetes n. sp. (Hypotrichida, Ciliophora) (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Diophrys scutum, collected from four locations on the New Hampshire coast, ranged from 89–195 7mu; in length, 50–105 μ in width, and 68–88 μ in buccal cavity length. The end of the adoral zone of membranelles (AZM) extends 37–59 μ (average = 45.6 μ) posteriorly in a groove on the right side of the body. Dorsally are five rows of stiff cilia. The silverline system (Chatton-Llvoff technique) appears as a fine meshwork, entirely different from that found in Euplotes or Uronychia. There are two elongate macronuclei (Feulgen reaction) and several micronuclei. Diophrys peloetes n. sp., collected from one location in Alligator Harbor. Florida, ranged from 95–134 μ in length, 62–84 μ in width. and 60–80 μ in buccal cavity length. The terminal portion of the AZM extends posteriorly in a groove 30–44 7mu; (average = 36.8 μ) on the right side of the body. Dorsally are eight rows of stiff cilia. The details of the silverline system are similar to those of D. scutum.There is insufficient difference in ranges of body length, width. and buccal cavity length to use these characters in separating the two species. However, a statistical analysis shows that the length of the portion of the AZM on the right side of the body in D. scutum is significantly different (longer) from that of D. peloetes. Furthermore, these two species differ not only in number of dorsal ciliary rows, but also in the number of cilia per row. The degree of difference in these two species is similar to that between closely related species in other hypotrich genera, and also to that between some varieties of Paramecium aurelia.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb01812.x
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  • 93
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    Intermediate Metabolism of Carbohydrates in Mayorella palestinensis (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. The mechanism of carbohydrate metabolism was studied in homogenates of the ameba, Mayorella palestinensis. The utilization of intermediates with the formation of lactic acid as the end product of the anaerobic breakdown of the carbohydrates was established. Evidence was obtained for the presence of the main enzymes associated with the Embden-Meyerhof glycolytic scheme. The activity of hexokinase and phosphorylase was ascertained in a M. pakstinensis homogenate. These enzymes have not yet been found among other soil amebas grown in axenic cultures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb01819.x
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  • 94
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    Inhibition by Chloramphenicol of Chlorophyll and Protein Synthesis and Growth in Euglena gracilis (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Chloramphenicol inhibits growth of Euglena gracilis. It also interferes in the “greening” process by inhibiting protein synthesis (measured by leucine uptake), but RNA synthesis is essentially unafiected. The antibiotic acts on all cell fractions, but prefermtially inhibits the synthesis of plastid protein. Inhibition of chlorophyll synthesis is transitory and does not affect the self-reproduction system for chloroplast formation.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb01820.x
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  • 95
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    The Amoeba-to-Flagellate Transformation in Tetramitus rostratus. I. Population Dynamics (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Thirty to 80% of Tetramitus rostratus amoebae were induced to transform into the flagellated stage. The procedure involved growth in a dilute hydrolyzed casein medium with living Escherichia coli dispensed in microdrops approximately 0.5 mm3 in volume and sealed in a slide-depressionchamber. Single amoebae placed in such microdrops did not transform until growth and division had produced a population density of 100 amoebae/mm3. Flagellation then began and proceeded rapidly.Analysis of growth and transformation in microdrops of different sizes but with equal numbers of amoebae, or of microdrops of the same size but different numbers of amoebae, suggested that the amoebae themselves were elaborating substances into the medium which brought about their own transformation. The effects of bacteriostasis induced by a variety of antibiotics did not clearly rule out a bacterial contribution to the factors causing transformation. Osmotic effects within physiological limits did not play any demonstrable role in inducing the response.It was concluded that transformation of amoebae to flagellates involved rapid growth and subsequent undetermined changes in the medium.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb01818.x
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  • 96
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    An Unusual Pattern of Tritiated Thymidine Incorporation in Euglena (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Thymidine-methyl-H2 is incorporated into the cytoplasm of Euglena. The label is non-nuclear and not in DNA; evidence for its presence in RNA and protein is presented. Only Euglena which maintain the potentiality to develop chloroplasts show this incorporation; it was not observed in streptomycin. uv, benadryl, O-methyl threonine or heat “bleached”Euglena, nor in Astasia longa.Preliminary incorporation experiments show that exogenous pyrimidines are not utilized as nucleic acid precursors in Euglena in general. However, the tritiated purines are incorporated into DNA and RNA. The use of thymidine to localize DNA autoradiographically in Euglena is completely excluded.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb01822.x
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  • 97
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    The Genus Lagenophrys Stein, 1852 (Ciliata, Peritricha) on Australasian Parastacidae (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
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    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. A survey of the genus Lagenophrys Stein, 1852 (Ciliata, Peritricha) on freshwater crayfish (Parastacidae) revealed a wide range of new species in Australia and New Zealand. Fourteen new species are described. L. seticola sp. nov. is close to L. vaginicola Stein. L. spinosa, L. bispinosa, L. latispinosa, L. communis, L. occlusa, L. lawrii, L. lingulata spp. nov. form one species group. L. willisi, L. rugosa, L. darwini, L. deserti, L. ditngogi and L. engaei spp. nov. form a second group distinguished by characters of the lorica, lorica mouth and macronucleus.Nenninger's classification of degree of specificity of commensal-host relationship is applied to the whole genus and expanded in the light of the Australian material. The zoogeographic problems resulting from the specificity of Lagenophrys and the limited range of some of its hosts are indicated.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb01823.x
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  • 98
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    A New Species of Plasmodium from the Formosan Shoveller Duck (Anas clypeata L.) (1965)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 12 (1965), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Blood films made from the “shoveller duck”, Anas clypeata Linnaeus 1758, in Lin-pien Ping-tung Hsien, Taiwan, showed a new species of avian malaria parasite, for which the name Plasmodium anasurn is proposed. This species is characterized by elongate gametocytes often closely resembling Huemopvoteus, about 15 merozoites per segmenter (although such stages were too few for really accurate counts), and trophozoites and schizonts which very often surround the extremities of the host cell nucleus in U-shaped fashion. Pigment is abundant, appears early, and is very dark. The host cell shows little or no alteration. No infected reticulocytes or blood cells other than erythrocytes were observed.
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    URL: http://dx.doi.org/10.1111/j.1550-7408.1965.tb01821.x
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  • 99
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    THE CANADIAN QUARTERLY NATIONAL ACCOUNTS—A CRITICAL APPRAISAL (1965)
    Oxford, UK : Blackwell Publishing Ltd
    Review of income and wealth 11 (1965), S. 0 
    Details
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1475-4991.1965.tb00987.x
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    THE NATIONAL INCOME OF THE U.A.R. (EGYPT) 1939–62 (1965)
    Oxford, UK : Blackwell Publishing Ltd
    Review of income and wealth 11 (1965), S. 0 
    Details
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1475-4991.1965.tb00991.x
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