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: 2015-07-21
    Description: Soil water retention curves (SWRCs) are usually obtained on the assumption small water menisci spread in the surface of particles yielding contact angles near zero degrees. While this is true at high water contents, where pores are filled by water or a film of water covers the particles, it is less likely for drier states, where the adhesion of water menisci to the surface of the particles is controlled by the nature of the particle surface (chemistry and surface roughness) and the presence of organic matter. Here, we investigate hysteretic effects in the relation between water content and soil particle wettability versus suction for model samples following drying and wetting paths. A comparison is done for a model material (mixture of sand and clay) with and without water repellent substances, being the samples with water repellent substances in a subcritical water repellent state (contact angles 〈90°). Wettability was manipulated by treatment with organic acids that mimic the chemistry of natural water repellent substances. Suction was measured directly with a high suction tensiometer and wettability via contact angles by the sessile drop method. The results revealed lower water retention and greater contact angles for the subcritical water repellent samples, following both drying and wetting paths. Hysteresis was present in the relation between the contact angles and suction for the subcritical water repellent samples.
    Electronic ISSN: 1539-1663
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2015-09-17
    Description: The ecological impacts of human activities have infiltrated the whole of the ‘natural world’ and precipitated calls for a newly defined geological epoch – the Anthropocene. While scholars discuss tipping-points and scale, viewed over the longue durée, it is becoming clear that we have inherited the compounding consequences of a constructed environment with a long history of human landscape modification. By linking phytolith and micro-charcoal evidence from sediments in the Azraq Basin, Jordan, we discuss potential Early Epipaleolithic (23,000–17,400 cal. BP) human–environment interactions in this wetland. Our analyses reveal that during the Last Glacial Maximum, Levantine hunter-gatherers could have had a noticeable and increasing impact on their environment. However, further work needs to be undertaken to assess the range, frequency, intensity, and intentionality of marsh disturbance events. We suggest that the origin of ‘persistent places’ and larger aggregation settlements in the Azraq Basin may have been, in part, facilitated by human–environment interactions in the Early Epipaleolithic that consequently enhanced the economic and, subsequently, social meaning of that landscape. Through their exploitation of the sensitive wetland environment, hunter-gatherers were modifying the marshes and initiating long-term changes to the already dynamic and changing landscape at the close of the Pleistocene. These findings challenge us to further reconsider the way we see early hunter-gatherers in the prehistory of the Levant and in the development of the ‘Anthropocene’.
    Print ISSN: 0959-6836
    Electronic ISSN: 1477-0911
    Topics: Geography , Geosciences
    Published by Sage
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2016-07-13
    Description: The relative importance of tectonics, climate, base level and source lithology as the primary controls on the evolution of alluvial fans is highly debated. This study examines the role of upstream catchment characteristics on the evolution of alluvial megafans by examining three Quaternary fans (the Kalahrud, Zefreh and Mughar fans) along the flanks of the Kohrud Mountain Range in central Iran. These fans formed in a tectonically active basin under arid to semi-arid climatic conditions. The key differences between the evolutionary trends of these fans are that their catchments are underlain by different bedrock types and they have different catchment shapes and outlet characteristics. The catchment of the Kalahrud fan is in a sedimentary terrain with limited sediment supply, whereas the bedrock lithologies of the Zefreh and Mughar fans are fractured and weathered igneous rocks. However, the evolution of the Mughar fan is also controlled by the tilting of the catchment towards a wide apex and lateral shifting in the catchment outlet/fan feeder channel position. These variables resulted in relatively large-scale incision in the Kalahrud and Mughar fans that is absent in the aggradational trend of the Zefreh fan. Upstream lithological and structural controls are the dominant drivers behind the development and evolution of alluvial megafans.
    Print ISSN: 0305-8719
    Electronic ISSN: 2041-4927
    Topics: Geosciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2016-05-29
    Description: We examine in detail a one-year global reanalysis of carbon monoxide (CO) that is based on joint assimilation of conventional meteorological observations and Measurement of Pollution in The Troposphere (MOPITT) multispectral CO retrievals in the Community Earth System Model (CESM). Our focus is to assess the impact to the chemical system when CO distribution is constrained in a coupled full chemistry-climate model like CESM. To do this, we first evaluate the joint reanalysis (MOPITT Reanalysis) against four sets of independent observations and compare its performance against a reanalysis with no MOPITT assimilation (Control Run). We then investigate the CO burden and chemical response with the aid of tagged sectoral CO tracers. We estimate the total tropospheric CO burden in 2002 (from ensemble mean and spread) to be 371 ±12% Tg for MOPITT Reanalysis and 291 ± 9 % Tg for Control Run. Our multi-species analysis of this difference suggests that: a) direct emissions of CO and hydrocarbons are too low in the inventory used in this study; and b) chemical oxidation, transport, and deposition processes are not accurately and consistently represented in the model. Increases in CO led to net reduction of OH and subsequent longer lifetime of CH 4 (Control Run: 8.7 years versus MOPITT Reanalysis: 9.3 years). Yet, at the same time, this increase led to 5-10% enhancement of northern hemisphere O 3 and overall photochemical activity via HO X recycling. Such nonlinear effects further complicate the attribution to uncertainties in direct emissions alone. This has implications to chemistry-climate modeling and inversion studies of longer-lived species.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2015-06-12
    Description: High-throughput genotyping arrays provide a standardized resource for plant breeding communities that are useful for a breadth of applications including high-density genetic mapping, genome-wide association studies (GWAS), genomic selection (GS), complex trait dissection, and studying patterns of genomic diversity among cultivars and wild accessions. We have developed the CottonSNP63K, an Illumina Infinium array containing assays for 45,104 putative intraspecific single nucleotide polymorphism (SNP) markers for use within the cultivated cotton species Gossypium hirsutum L. and 17,954 putative interspecific SNP markers for use with crosses of other cotton species with G. hirsutum . The SNPs on the array were developed from 13 different discovery sets that represent a diverse range of G. hirsutum germplasm and five other species: G. barbadense L., G. tomentosum Nuttal x Seemann, G. mustelinum Miers x Watt, G. armourianum Kearny, and G. longicalyx J.B. Hutchinson and Lee. The array was validated with 1,156 samples to generate cluster positions to facilitate automated analysis of 38,822 polymorphic markers. Two high-density genetic maps containing a total of 22,829 SNPs were generated for two F 2 mapping populations, one intraspecific and one interspecific, and 3,533 SNP markers were co-occurring in both maps. The produced intraspecific genetic map is the first saturated map that associates into 26 linkage groups corresponding to the number of cotton chromosomes for a cross between two G. hirsutum lines. The linkage maps were shown to have high levels of collinearity to the JGI G. raimondii Ulbrich reference genome sequence. The CottonSNP63K array, cluster file and associated marker sequences constitute a major new resource for the global cotton research community.
    Electronic ISSN: 2160-1836
    Topics: Biology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2015-01-24
    Description: Systematic interrogation of mutation or protein modification data is important to identify sites with functional consequences and to deduce global consequences from large data sets. Mechismo ( mechismo.russellab.org ) enables simultaneous consideration of thousands of 3D structures and biomolecular interactions to predict rapidly mechanistic consequences for mutations and modifications. As useful functional information often only comes from homologous proteins, we benchmarked the accuracy of predictions as a function of protein/structure sequence similarity, which permits the use of relatively weak sequence similarities with an appropriate confidence measure. For protein–protein, protein–nucleic acid and a subset of protein–chemical interactions, we also developed and benchmarked a measure of whether modifications are likely to enhance or diminish the interactions, which can assist the detection of modifications with specific effects. Analysis of high-throughput sequencing data shows that the approach can identify interesting differences between cancers, and application to proteomics data finds potential mechanistic insights for how post-translational modifications can alter biomolecular interactions.
    Keywords: Polymorphism/mutation detection, Computational Methods
    Print ISSN: 0305-1048
    Electronic ISSN: 1362-4962
    Topics: Biology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2015-01-28
    Description: Axon initial segments (AISs) and nodes of Ranvier are sites of clustering of voltage-gated sodium channels (VGSCs) in nervous systems of jawed vertebrates that facilitate fast long-distance electrical signaling. We demonstrate that proximal axonal polarity as well as assembly of the AIS and normal morphogenesis of nodes of Ranvier all...
    Keywords: Inaugural Articles
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2016-02-05
    Description: Carbon cycle uncertainties associated with the Intergovernmental Panel on Climate Change temperature-change projections were treated differently between the Fourth and Fifth Assessment Reports as the latter focused on concentration- rather than emission-driven experiments. Carbon cycle feedbacks then relate to the emissions consistent with a particular concentration. A valuable alternative is to include all uncertainties in a single step from emissions to temperatures. We use a simple climate model with an observationally constrained parameter distribution to explore the carbon cycle and temperature-change projections, simulating the emission-driven Representative Concentration Pathways. The resulting range of uncertainty is a somewhat wider and asymmetric likely range (biased high).
    Electronic ISSN: 1530-261X
    Topics: Geosciences , Physics
    Published by Wiley on behalf of The Royal Meteorological Society (RMetS).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2012-02-23
    Description: Nonlinear anthropogenic warming is detected and attributed as a series of step changes in observed and simulated climate for southeastern Australia (SEA). A stationary period of 1910–1967 and non-stationary period of 1968–2010 was established using statistically significant step-changes (pH0 〈 0.01) in the relationship between observed minimum (Tmin) and maximum (Tmax) temperature (0.6°C in 1968) and Tmax and rainfall (P; 0.7°C in 1997). Regressions between these pairings during stationary conditions were used to determine how Tmin and Tmax would have evolved under non-stationary conditions. Assuming these relationships remain constant, the resulting residuals were attributed to anthropogenic regional warming. This warming was initiated as step changes in 1968 for Tmin (0.7°C) and 1973 for Tmax (0.5°C), coinciding with step changes in zonal (24–44°S) and southern hemisphere mean air temperatures (Tav). A step change in 1997 in Tmax (0.8°C) coincided with a statistically significant step change in global mean air temperature of 0.3°C. This analysis was repeated using regionally averaged output from eleven climate model simulations. Regional warming in all models commenced with step changes in Tmin ranging from 0.4 to 0.7°C between 1964 and 2003. Tmax underwent step changes ranging from 0.7 to 1.1°C simultaneously or within several decades. Further step changes, combined with rising trends, were simulated under increasing radiative forcing to 2100. This highlights limitations in the current use of the signal-to-noise model that considers anthropogenic climate change as a monotonic curve. The identification of multiple step changes in a changing climate provides important information for planning adaptation.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2019
    Description: 〈p〉Modern observations appear to link warming oceanic conditions with Antarctic ice sheet grounding-line retreat. Yet, interpretations of past ice sheet retreat over the last deglaciation in the Ross Embayment, Antarctica’s largest catchment, differ considerably and imply either extremely high or very low sensitivity to environmental forcing. To investigate this, we perform regional ice sheet simulations using a wide range of atmosphere and ocean forcings. Constrained by marine and terrestrial geological data, these models predict earliest retreat in the central embayment and rapid terrestrial ice sheet thinning during the Early Holocene. We find that atmospheric conditions early in the deglacial period can enhance or diminish ice sheet sensitivity to rising ocean temperatures, thereby controlling the initial timing and spatial pattern of grounding-line retreat. Through the Holocene, however, grounding-line position is much more sensitive to subshelf melt rates, implicating ocean thermal forcing as the key driver of past ice sheet retreat.〈/p〉
    Electronic ISSN: 2375-2548
    Topics: Natural Sciences in General
    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...