ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2022-08-05
    Description: Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 115 (2018): 3072-3077, doi:10.1073/pnas.1716137115.
    Description: The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals’ movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyse a global dataset of 2.8 million locations from 〉 2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared to more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal micro-habitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise and declining oxygen content.
    Description: Workshops funding granted by the UWA Oceans Institute, AIMS, and KAUST. AMMS was supported by an ARC Grant DE170100841 and an IOMRC (UWA, AIMS, CSIRO) fellowship; JPR by MEDC (FPU program, Spain); DWS by UK NERC and Save Our Seas Foundation; NQ by FCT (Portugal); MMCM by a CAPES fellowship (Ministry of Education).
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 6393-6403 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A microscopic model of lyotropic systems is presented. Amphiphile and water molecules are described by simple intermolecular potentials which correctly include important excluded volume effects and the relative energy scales in the system. The present model represents an attempt to bridge the gap between more primitive lattice models and highly complex all-atom descriptions of amphiphilic systems. A constant-temperature molecular dynamics study in which the divergence of the pressure tensor is constrained to zero is discussed. Preliminary calculations on the phase diagram, order parameters, and dynamical observables of the model are reported. Some comments on improvements to the model and the theoretical techniques used to study it are made in the final section of the paper.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 3152-3169 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A three-component lattice model with unit-vector orientations at the lattice sites is presented. The model describes ternary mixtures of oil, water, and amphiphile, and in particular the microemulsion phase. The phase diagram of the model is derived using mean-field theory and simulation. It is shown that the results of Monte Carlo simulations of sufficiently large systems show remarkable agreement with experiment. In particular, the present model reproduces the mesoscopic order of the microemulsion phase. The structure of the microemulsion is understood in terms of the liquid-crystalline phases adjacent to it on the phase diagram and the nature of the phase transitions that occur between them. The behavior of the system when the ratio of oil to water is changed is investigated and the percolation threshold is described. A method for carrying out dynamical simulations is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Cambridge, MA, USA : Blackwell Science, Inc.
    Restoration ecology 6 (1998), S. 0 
    ISSN: 1526-100X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: This review of long-term monitoring and experimental manipulation studies from Ontario, Canada, offers encouraging evidence that lake trout (Salvelinus namaycush) populations can be restored to acidified lakes once the problem of acid deposition is solved in North America. Predicting the rate of chemical and biological recovery remains difficult, because there are several limnological attributes (dissolved organic carbon, flushing rate) and biological attributes (acid sensitivity, species longevity, fish community composition) of lake trout ecosystems that can either enhance or delay the recovery process. Some options for managing recovering lakes are also reviewed, including increased pollution controls, liming, hatchery stocking, and harvest controls.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 98 (1994), S. 702-711 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 106 (1997), S. 4270-4281 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We present a new simulation algorithm for minimizing empirical contact potentials for a simplified model of protein structure. The model consists of backbone atoms only (including Cβ) with the φ and ψ dihedral angles as the only degrees of freedom. In addition, φ and ψ are restricted to a finite set of 532 discrete pairs of values, and the secondary structural elements are held fixed in ideal geometries. The potential function consists of a look-up table based on discretized inter-residue atomic distances. The minimization consists of two principal elements: the use of preselected lists of trial moves and the use of a genetic algorithm. The trial moves consist of substitutions of one or two complete loop regions, and the lists are in turn built up using preselected lists of randomly-generated three-residue segments. The genetic algorithm consists of mutation steps (namely, the loop replacements), as well as a hybridization step in which new structures are created by combining parts of two "parents'' and a selection step in which hybrid structures are introduced into the population. These methods are combined into a Monte Carlo simulated annealing algorithm which has the overall structure of a random walk on a restricted set of preselected conformations. The algorithm is tested using two types of simple model potential. The first uses global information derived from the radius of gyration and the rms deviation to drive the folding, whereas the second is based exclusively on distance-geometry constraints. The hierarchical algorithm significantly outperforms conventional Monte Carlo simulation for a set of test proteins in both cases, with the greatest advantage being for the largest molecule having 193 residues. When tested on a realistic potential function, the method consistently generates structures ranked lower than the crystal structure. The results also show that the improved efficiency of the hierarchical algorithm exceeds that which would be anticipated from tests on either of the two main elements used independently. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 109 (1987), S. 7816-7823 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 106 (1997), S. 3248-3257 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A method is introduced for carrying out semi-empirical energy calculations using a localized valence-bond wavefunction. Chemical bonds are described by correlated electron pairs, with interactions between pairs treated iteratively with a classical approximation at large distance. The model consists of a minimal basis of localized hybrid valence orbitals with semi-empirical approximation for the electron integrals and core repulsions. Parameters are determined for oxygen and hydrogen which are fit to the MP2/6-31G** potential surfaces of H2O and (H2O)2 with 0.5 kcal/mol accuracy. Results are shown for other neutral and charged water clusters, including a water chain of up to 200 H2O molecules for which the calculation shows O(N1.5) scaling with size. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Antimicrobial peptides are distributed throughout the animal kingdom and are a key component of innate immunity. Salmonella typhimurium regulates mechanisms of resistance to cationic antimicrobial peptides through the two-component systems PhoP–PhoQ and PmrA–PmrB. Polymyxin resistance is encoded by the PmrA–PmrB regulon, whose products modify the lipopolysaccharide (LPS) core and lipid A regions with ethanolamine and add aminoarabinose to the 4′ phosphate of lipid A. Two PmrA–PmrB-regulated S. typhimurium loci (pmrE and pmrF ) have been identified that are necessary for resistance to polymyxin and for the addition of aminoarabinose to lipid A. One locus, pmrE, contains a single gene previously identified as pagA (or ugd ) that is predicted to encode a UDP-glucose dehydrogenase. The second locus, pmrF, is the second gene of a putative operon predicted to encode seven proteins, some with similarity to glycosyltransferases and other complex carbohydrate biosynthetic enzymes. Genes immediately flanking this putative operon are also regulated by PmrA–PmrB and/or have been associated with S. typhimurium polymyxin resistance. This work represents the first identification of non-regulatory genes necessary for modification of lipid A and subsequent antimicrobial peptide resistance, and provides support for the hypothesis that lipid A aminoarabinose modification promotes resistance to cationic antimicrobial peptides.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Analysis of the transcriptome of slyA mutant Salmonella enterica serovar Typhimurium revealed that many SlyA-dependent genes, including pagC, pagD, ugtL, mig-14, virK, phoN, pgtE, pipB2, sopD2, pagJ and pagK, are also controlled by the PhoP/PhoQ regulatory system. Many SlyA- and PhoP/PhoQ-co-regulated genes have functions associated with the bacterial envelope, and some have been directly implicated in virulence and resistance to antimicrobial peptides. Purified His-tagged SlyA binds to the pagC and mig-14 promoters in regions homologous to a previously proposed ‘SlyA-box’. The pagC promoter lacks a consensus PhoP binding site and does not bind PhoP in vitro, suggesting that the effect of PhoP on pagC transcription is indirect. Stimulation of pagC expression by PhoP requires SlyA. Levels of SlyA protein and mRNA are not significantly changed under low-magnesium PhoP-inducing conditions in which pagC expression is profoundly elevated, however, indicating that the PhoP/PhoQ system does not activate pagC expression by altering SlyA protein concentration. Models are proposed in which PhoP may control SlyA activity via a soluble ligand or SlyA may function as an anti-repressor to allow PhoP activation. The absence of almost all SlyA-activated genes from the Escherichia coli K12 genome suggests that the functional linkage between the SlyA and PhoP/PhoQ regulatory systems arose as Salmonella evolved its distinctive pathogenic lifestyle.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...