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: 2016-07-26
    Description: The Journal of Organic Chemistry DOI: 10.1021/acs.joc.6b01272
    Print ISSN: 0022-3263
    Electronic ISSN: 1520-6904
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2016-07-29
    Description: The primary objective of this study was to test the relevance of hydrological classification and class differences to the characteristics of woody riparian vegetation in a subtropical landscape in Queensland, Australia. We followed classification procedures of the environmental flow framework ELOHA – Ecological Limits of Hydrologic Alteration. Riparian surveys at 44 sites distributed across five flow classes recorded 191 woody riparian species and 15, 500 individuals. There were differences among flow classes for riparian species richness, total abundance, and abundance of regenerating native trees and shrubs. There were also significant class differences in the occurrence of three common tree species, and 21 indicator species (mostly native taxa) further distinguished the vegetation characteristics of each flow class. We investigated the influence of key drivers of riparian vegetation structure (climate, depth to water table, stream-specific power, substrate type, degree of hydrologic alteration, and land use) on riparian vegetation. Patterns were explained largely by climate, particularly annual rainfall and temperature. Strong covarying drivers (hydrology and climate) prevented us from isolating the independent influences of these drivers on riparian assemblage structure. The prevalence of species considered typically rheophytic in some flow classes implies a more substantial role for flow in these classes but needs further testing. No relationships were found between land use and riparian vegetation composition and structure. This study demonstrates the relevance of flow classification to the structure of riparian vegetation in a subtropical landscape, and the influence of covarying drivers on riparian patterns. Management of environmental flows to influence riparian vegetation assemblages would likely have most potential in sites dominated by rheophytic species where hydrological influences override other controls. In contrast, where vegetation assemblages are dominated by a diverse array of typical rainforest species, and other factors including broad-scale climatic gradients and topographic variables have greater influence than hydrology, riparian vegetation is likely to be less responsive to environmental flow management. This study demonstrates the relevance of an ELOHA-type flow classification to variation in the structure of riparian vegetation across a subtropical landscape, and the importance of studying the influence of covarying drivers (particularly climate) on riparian vegetation patterns. Management of environmental flows to influence riparian vegetation assemblages would likely have most potential in sites dominated by rheophytic species where hydrological influences override other controls.
    Electronic ISSN: 2045-7758
    Topics: Biology
    Published by Wiley
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2015-05-14
    Description: Questions Do nurse plant interactions significantly influence understorey vegetation diversity in a large, semi-arid, shrub-dominated wetland? How do the modes and net effects of nurse plant interactions vary spatially along a flood frequency gradient, and temporally in response to drying? Location Narran Lakes Ramsar site, New South Wales, Australia. Methods Microhabitat characteristics, understorey vegetation and germinable soil seed banks were investigated in shrub and open habitats across a flood frequency gradient in a large, semi-arid wetland dominated by open shrubland under productive conditions following floodwater recession and again following 6 mo of drought. Split-plot ANOVA and multivariate analyses were used to determine the effects of shrubs on microhabitat character, understorey vegetation cover, species diversity, richness and composition and germinable soil seed banks. Results Microhabitat characteristics, including canopy cover, litter cover and soil character, all differed between shrub and open habitats, especially in the most frequently flooded sites. Under productive conditions following flooding, lignum shrubs suppressed understorey vegetation cover but increased species richness at the site scale across the flood frequency gradient and, in the most frequently flooded sites, supported higher species density at a microhabitat scale. Under dry conditions, lignum shrubs had a positive effect on understorey vegetation cover, species richness and species density across the flood frequency gradient, but particularly in frequently flooded sites. A significant difference in soil seed bank composition between shrub and open habitats was only observed in frequently flooded sites. Conclusions Nurse plant interactions appear to play an important role in determining understorey vegetation diversity in the lignum shrubland of the Narran Lakes wetland system. The modes and net effects of these nurse plant interactions vary in space and time in relation to flood history and drying. Positive interactions, probably involving microhabitat amelioration, appear to be particularly important to plant diversity and abundance under dry conditions. Under more favourable wetter conditions, lignum shrubs also contribute to understorey vegetation diversity by facilitating the establishment of different species than those dominating open habitats. Our findings have implications for the management of perennial shrubs and hydrological regimes in such wetlands. In a hydrologically variable wetland in semi-arid Australia nurse plant interactions contributed to the diversity of understorey plant communities but varied in their mode and net effects. Under dry conditions, shrubs had a predominantly positive effect on understorey plants.  In wetter conditions shrubs exerted negative influences on the dominant understorey species but appeared to facilitate establishment of rarer species.
    Print ISSN: 1100-9233
    Electronic ISSN: 1654-1103
    Topics: Biology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2016-06-14
    Description: Questions How diverse and resilient is vegetation following a decade of extreme drought along a typical floodplain gradient of semi-arid south-eastern Australia? How do mechanisms of resilience (i.e. persistence and soil seed banks) vary between major plant groups and spatially with respect to habitat type and position along a flood frequency gradient? Location Southern Murray-Darling Basin, Australia. Methods We surveyed understorey vegetation and conducted germination trials to examine responses to re-wetting from soil seed banks of seven major habitat types along a typical floodplain gradient of the southern Murray-Darling Basin. We assessed abundance, species richness, functional diversity and composition, including exotic species, within and between extant and germinating assemblages. Results Understorey vegetation was surprisingly diverse, although low in cover, following a decade of extreme drought, with considerable numbers of plant species (61) and functional plant groups represented. Historically drier habitats, towards floodplain margins, had higher species richness and cover overall and for exotic species. Plant assemblages exhibited high heterogeneity between habitats. Soil seed banks were very dissimilar from extant vegetation, comprising mainly amphibious and damp taxa as well as some terrestrial herbs, mostly annuals. Seed banks were most abundant and diverse in intermediate floodplain habitats, and their composition was very distinct between habitat types. Conclusions Semi-arid floodplain vegetation is likely to be highly resilient to prolonged drought. Plants persisting under dry conditions do not appear to rely on local soil seed banks for regeneration and may either tolerate drying in situ or arrive from neighbouring ecosystems. Soil seed banks allow understorey vegetation to respond to re-wetting, especially in intermediate floodplain habitats. Lake bed assemblages and aquatic/amphibious species lacking soil seed banks appear most vulnerable to drought. Vegetation resilience is promoted by landscape heterogeneity. Semi-arid floodplain vegetation of the southern Murray-Darling Basin was found to be highly resilient to prolonged drought. Relatively high species (61) and functional diversity persisted after a decade of drying. Diverse soil seed-banks facilitate understory responses to re-wetting rather than persistence during drought. Lake bed vegetation and non-seed bank aquatic species appear most vulnerable to drought.
    Print ISSN: 1100-9233
    Electronic ISSN: 1654-1103
    Topics: Biology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2016-08-19
    Description: Organic Letters DOI: 10.1021/acs.orglett.6b02099
    Print ISSN: 1523-7060
    Electronic ISSN: 1523-7052
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2015-12-08
    Description: The Journal of Organic Chemistry DOI: 10.1021/acs.joc.5b02367
    Print ISSN: 0022-3263
    Electronic ISSN: 1520-6904
    Topics: Chemistry and Pharmacology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2019
    Description: Abstract Aim Riparian ecosystems are regarded as vulnerable to the effects of climate change. Because of their reliance on passive dispersal to migrate from areas where conditions have become unfavourable, plants are particularly susceptible. On dryland river floodplains, the species diversity of herbaceous annuals is often high while that of structurally dominant woody perennials is low. We examined gene flow genetic structure and dispersal in Acacia stenophylla, a small perennial tree widely distributed throughout river systems of inland Australia. The role of the river corridor in shaping patterns of gene flow and genetic structure is also investigated. Location Murray‐Darling Basin, south eastern Australia Methods A total of 127 individuals, from 12 subpopulations located on seven rivers were genotyped at 13 microsatellite loci. Several population and landscape genetic tools were applied to the microsatellite data to evaluate spatial patterns of gene flow and genetic structure and make inferences regarding possible modes of dispersal. Results High gene flow and weak genetic structure was identified for the 12 subpopulations of A. stenophylla sampled, a surprising result given large distances between subpopulations. Pairwise genetic distance between subpopulations was low to moderate and could largely be explained (R2 = 0.68) by two variables: distance along the river and the proportion of no flow days. structure analysis revealed two genetic clusters. Subpopulations located on the Darling and Lower Balonne rivers were dominated by cluster one while subpopulations from the Warrego and Paroo rivers showed largely mixed ancestry with individuals descending from both clusters one and two. Main Conclusions These results indicate that the river corridor facilitates extensive gene flow between subpopulations of A. stenophylla in this system. Hydrochory appears to be the dominant process; however, upstream movements of propagules most probably via animal movement are sufficient to negate effects expected under unidirectional dispersal.
    Print ISSN: 0305-0270
    Electronic ISSN: 1365-2699
    Topics: Biology , Geography
    Published by Wiley
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 1988-11-25
    Description: The gp120 envelope glycoprotein of the human immunodeficiency virus (HIV), which is expressed on the surface of many HIV-infected cells, binds to the cell surface molecule CD4. Soluble derivatives of recombinant CD4 (rCD4) that bind gp120 with high affinity are attractive vehicles for targeting a cytotoxic reagent to HIV-infected cells. Soluble rCD4 was conjugated to the active subunit of the toxin ricin. This conjugate killed HIV-infected H9 cells but was 1/1000 as toxic to uninfected H9 cells (which do not express gp120) and was not toxic to Daudi cells (which express major histocompatibility class II antigens, the putative natural ligand for cell surface CD4). Specific killing of infected cells can be blocked by rgp120, rCD4, or a monoclonal antibody to the gp120 binding site on CD4.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Till, M A -- Ghetie, V -- Gregory, T -- Patzer, E J -- Porter, J P -- Uhr, J W -- Capon, D J -- Vitetta, E S -- CA-09082/CA/NCI NIH HHS/ -- CA-28149/CA/NCI NIH HHS/ -- CA-41081/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1988 Nov 25;242(4882):1166-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2847316" target="_blank"〉PubMed〈/a〉
    Keywords: Antigens, Differentiation, T-Lymphocyte/*administration & dosage/immunology ; Binding Sites ; Cell Line ; Cell Survival ; Electrophoresis, Polyacrylamide Gel ; HIV/*immunology ; HIV Envelope Protein gp120 ; Histocompatibility Antigens Class II/immunology ; Humans ; Recombinant Proteins/administration & dosage/immunology ; Retroviridae Proteins/*immunology/metabolism ; Ricin/metabolism/*pharmacology ; T-Lymphocytes/immunology/microbiology/physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 1989-08-18
    Description: CD4 is a cell surface glycoprotein that is thought to interact with nonpolymorphic determinants of class II major histocompatibility (MHC) molecules. CD4 is also the receptor for the human immunodeficiency virus (HIV), binding with high affinity to the HIV-1 envelope glycoprotein, gp120. Homolog-scanning mutagenesis was used to identify CD4 regions that are important in class II MHC binding and to determine whether the gp120 and class II MHC binding sites of CD4 are related. Class II MHC binding was abolished by mutations in each of the first three immunoglobulin-like domains of CD4. The gp120 binding could be abolished without affecting class II MHC binding and vice versa, although at least one mutation examined reduced both functions significantly. These findings indicate that, while there may be overlap between the gp120 and class II MHC binding sites of CD4, these sites are distinct and can be separated. Thus it should be possible to design CD4 analogs that can block HIV infectivity but intrinsically lack the ability to affect the normal immune response by binding to class II MHC molecules.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lamarre, D -- Ashkenazi, A -- Fleury, S -- Smith, D H -- Sekaly, R P -- Capon, D J -- New York, N.Y. -- Science. 1989 Aug 18;245(4919):743-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratoire d'Immunologie, Institut de Recherches Cliniques de Montreal, Quebec, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2549633" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Animals ; Antigens, Surface ; Binding Sites ; DNA, Recombinant ; HIV/*metabolism ; HIV Envelope Protein gp120 ; HLA-DP Antigens/immunology ; Histocompatibility Antigens Class II/*immunology ; Humans ; Hybridomas ; Mice ; Molecular Sequence Data ; Mutation ; Receptors, HIV ; Receptors, Virus/genetics/immunology/*metabolism ; Retroviridae Proteins/immunology/*metabolism ; Rosette Formation ; Structure-Activity Relationship ; T-Lymphocytes/immunology/metabolism ; Transfection
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2018-08-17
    Description: Inter-Kingdom beach warfare: Microbial chemical communication activates natural chemical defences Inter-Kingdom beach warfare: Microbial chemical communication activates natural chemical defences, Published online: 16 August 2018; doi:10.1038/s41396-018-0265-z Inter-Kingdom beach warfare: Microbial chemical communication activates natural chemical defences
    Print ISSN: 1751-7362
    Electronic ISSN: 1751-7370
    Topics: Biology
    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...