877 resultados para American Association for the Advancement of Science. Pacific Division. Meeting.
Resumo:
The conservation of large carnivores is a formidable challenge for biodiversity conservation. Using a data set on the past and current status of brown bears (Ursus arctos), Eurasian lynx (Lynx lynx), gray wolves (Canis lupus), and wolverines (Gulo gulo) in European countries, we show that roughly one-third of mainland Europe hosts at least one large carnivore species, with stable or increasing abundance in most cases in 21st-century records. The reasons for this overall conservation success include protective legislation, supportive public opinion, and a variety of practices making coexistence between large carnivores and people possible. The European situation reveals that large carnivores and people can share the same landscape.
Resumo:
An estimated 6051 tons of active substances went into the production of veterinary pharmaceuticals (VPs) for the treatment of food animals in the European Union (EU) in 2004, including 5393 tons of antibiotics and 194 tons of antiparasitics (1). With global meat production projected to increase (2) and the growing market for companion animal pharmaceuticals (3), the use of VPs will continue to increase. Although VPs may benefit the health and welfare of domestic animals and the efficiency of food animal production, they can contaminate the environment through manufacturing, treatment of animals, and disposal of carcasses, offal, urine, feces, and unused products (4) (see the chart). This contamination is a threat to nontarget species, including humans. With Spain having recently authorized marketing of a VP that was banned in South Asia in the past decade in light of environmental impacts, we recommend strengthening of current procedures and addition of a more proactive, holistic, One Health approach applicable to all VPs.
Resumo:
The search for predictions of species diversity across environmental gradients has challenged ecologists for decades. The humped-back model (HBM) suggests that plant diversity peaks at intermediate productivity; at low productivity few species can tolerate the environmental stresses, and at high productivity a few highly competitive species dominate. Over time the HBM has become increasingly controversial, and recent studies claim to have refuted it. Here, by using data from coordinated surveys conducted throughout grasslands worldwide and comprising a wide range of site productivities, we provide evidence in support of the HBM pattern at both global and regional extents. The relationships described here provide a foundation for further research into the local, landscape, and historical factors that maintain biodiversity.
Resumo:
Despite the paradigm that carbohydrates are T cell-independent antigens, isotype-switched glycan-specific immunoglobulin G (IgG) antibodies and polysaccharide-specific T cells are found in humans. We used a systems-level approach combined with glycan array technology to decipher the repertoire of carbohydrate-specific IgG antibodies in intravenous and subcutaneous immunoglobulin preparations. A strikingly universal architecture of this repertoire with modular organization among different donor populations revealed an association between immunogenicity or tolerance and particular structural features of glycans. Antibodies were identified with specificity not only for microbial antigens but also for a broad spectrum of host glycans that serve as attachment sites for viral and bacterial pathogens and/or exotoxins. Tumor-associated carbohydrate antigens were differentially detected by IgG antibodies, whereas non-IgG2 reactivity was predominantly absent. Our study highlights the power of systems biology approaches to analyze immune responses and reveals potential glycan antigen determinants that are relevant to vaccine design, diagnostic assays, and antibody-based therapies.
Resumo:
In order to explore the diversity and selective signatures of duplication and deletion human copy number variants (CNVs), we sequenced 236 individuals from 125 distinct human populations. We observed that duplications exhibit fundamentally different population genetic and selective signatures than deletions and are more likely to be stratified between human populations. Through reconstruction of the ancestral human genome, we identify megabases of DNA lost in different human lineages and pinpoint large duplications that introgressed from the extinct Denisova lineage now found at high frequency exclusively in Oceanic populations. We find that the proportion of CNV base pairs to single nucleotide variant base pairs is greater among non-Africans than it is among African populations, but we conclude that this difference is likely due to unique aspects of non-African population history as opposed to differences in CNV load.
Resumo:
Bipolar elongation of filaments of the bacterial actin homolog ParM drives movement of newly replicated plasmid DNA to opposite poles of a bacterial cell. We used a combination of vitreous sectioning and electron cryotomography to study this DNA partitioning system directly in native, frozen cells. The diffraction patterns from overexpressed ParM bundles in electron cryotomographic reconstructions were used to unambiguously identify ParM filaments in Escherichia coli cells. Using a low-copy number plasmid encoding components required for partitioning, we observed small bundles of three to five intracellular ParM filaments that were situated close to the edge of the nucleoid. We propose that this may indicate the capture of plasmid DNA within the periphery of this loosely defined, chromosome-containing region.
Resumo:
The skin of an adult human contains about 20 billion memory T cells. Epithelial barrier tissues are infiltrated by a combination of resident and recirculating T cells in mice, but the relative proportions and functional activities of resident versus recirculating T cells have not been evaluated in human skin. We discriminated resident from recirculating T cells in human-engrafted mice and lymphoma patients using alemtuzumab, a medication that depletes recirculating T cells from skin, and then analyzed these T cell populations in healthy human skin. All nonrecirculating resident memory T cells (TRM) expressed CD69, but most were CD4(+), CD103(-), and located in the dermis, in contrast to studies in mice. Both CD4(+) and CD8(+) CD103(+) TRM were enriched in the epidermis, had potent effector functions, and had a limited proliferative capacity compared to CD103(-) TRM. TRM of both types had more potent effector functions than recirculating T cells. We observed two distinct populations of recirculating T cells, CCR7(+)/L-selectin(+) central memory T cells (TCM) and CCR7(+)/L-selectin(-) T cells, which we term migratory memory T cells (TMM). Circulating skin-tropic TMM were intermediate in cytokine production between TCM and effector memory T cells. In patients with cutaneous T cell lymphoma, malignant TCM and TMM induced distinct inflammatory skin lesions, and TMM were depleted more slowly from skin after alemtuzumab, suggesting that TMM may recirculate more slowly. In summary, human skin is protected by four functionally distinct populations of T cells, two resident and two recirculating, with differing territories of migration and distinct functional activities.
Resumo:
We have searched for periodic variations of the electronic recoil event rate in the (2-6) keV energy range recorded between February 2011 and March 2012 with the XENON100 detector, adding up to 224.6 live days in total. Following a detailed study to establish the stability of the detector and its background contributions during this run, we performed an un-binned profile likelihood analysis to identify any periodicity up to 500 days. We find a global significance of less than 1 sigma for all periods suggesting no statistically significant modulation in the data. While the local significance for an annual modulation is 2.8 sigma, the analysis of a multiple-scatter control sample and the phase of the modulation disfavor a dark matter interpretation. The DAMA/LIBRA annual modulation interpreted as a dark matter signature with axial-vector coupling of WIMPs to electrons is excluded at 4.8 sigma.
Resumo:
A continuous record of atmospheric lead since 12,370 carbon-14 years before the present (14C yr BP) is preserved in a Swiss peat bog. Enhanced fluxes caused by climate changes reached their maxima 10,590 14C yr BP (Younger Dryas) and 823014C yr BP. Soil erosion caused by forest clearing and agricultural tillage increased lead deposition after 532014C yr BP. Increasing lead/scandium and decreasing lead-206/lead-207 beginning 3000 14C yr BP indicate the beginning of lead pollution from mining and smelting, and anthropogenic sources have dominated lead emissions ever since. The greatest lead flux (15.7 milligrams per square meter per year in A.D. 1979) was 1570 times the natural, background value (0.01 milligram per square meter per year from 8030 to 5320 14C yr BP).
Resumo:
Making plants resistant to salty environments would be a boon for developing countries where poor land management has rendered large areas of arable land unfit for crop production. In a Perspective, Frommer and colleagues discuss how genetic engineering can be used to confer salt tolerance on plants ( see Apse et al.) and explore the implications of this feat for improving crop production in developing countries.
Resumo:
With an emphasis on systems analyses, the VSV-EBOVAC project harnesses state-of-the-art technologies that illuminate mechanisms behind the observed immunogenicity and reactogenicity of the rVSV-ZEBOV vaccine and ensures that such information is shared among stakeholders.
Resumo:
1 Brief von Max Horkheimer an Abel, 16.03.1936; 3 Briefe zwischen Hubert Abrahamsohn und Max Horkheimer, 1935-1936, 21.12.1936; 2 Briefe zwischen Emanuel Adler und Max Horkheimer, 12.04.1946, 26.04.1946; 2 Briefe zwischen Max Adler und Max Horkheimer, 16.03.1935, 29.03.1935; 1 Brief von Eva Ahamson an Max Horkheimer, 01.11.1944; 2 Briefe der Aircraft Warning Service Brentwood an Max Horkheimer, Mai 1942; 6 Briefe zwischen Librairie Félix Alcan und Max Horkheimer, 1935, 18.12.1935; 11 Briefe zwischen Franz Alexander und Max Horkheimer, 1938-1940; 2 Briefe zwischen der American Historical Review New York und Max Horkheimer, 01.04.1941, 07.04.1941; 1 Brief von Paul Reiwald an Max Horkheimer, 18.10.1940; 2 Briefe zwischen Helen Manice Alexander und Max Horkheimer, 1936; 2 Briefe zwischen Bernardine Allen und Max Horkheimer, 17.06.1938, 24.06.1938; 1 Brief der Alumni Federation of Columbia University an Max Horkheimer, 21.07.1942; 1 Brief der American Friends Service Comittee an Max Horkheimer, 10.12.1940; 3 Briefe zwischen der American Academy of Political and Social Science Philadelphia und Max Horkheimer, 1939,1940, 16.01.1939; 1 Brief der American Automobile Association Washington an Max Horkheimer, 22.03.1938; 1 Brief der American Association for the Advancement of Science Washington an Max Horkheimer, 16.08.1937; 2 Briefe von Max Horkheimer an den American Consulate General Berlin, 1939; 1 Brief von Max Horkheimer an den American Consulate General Havana, 03.03.1941; 4 Briefe von Max Horkheimer an den American Consul London, 1939-1941; 2 Briefe von Max Horkheimer an den American Consulate General Stuttgart, 1939-1941; 1 Brief von Max Horkheimer an den American Consul Zürich, 1939; 1 Brief von Friedrich Pollock an den American Council of Learned Society, Washington, 27.06.1941; 2 Briefe von Max Horkheimer an die American Friends of German Freedom New York, 1941; 4 Briefe der American Historical Association Washington an Max Horkheimer, 1937-1938; 1 Brief von Max Horkheimer an den American Red Cross Westwood Office, 21.06.1943; 18 Briefe zwschen der American Society for the Prevention of Cruelty to Animals New York und Max Horkheimer, 1936-1941; 1 Brief von Max Horkheimer an die American Women's Volunteer Service Pacific Palisades, 27.07.1942; 23 Briefe zwischen Eugene Anderson und Max Horkheimer, 1937-1941; 2 Briefe zwischen Norah Andreae und Max Horkheimer, 27.10.1944, 09.09.1946; 1 Brief von Rosa Nebel-Schenk, 04.03.1946; 1 Brief von der National Catholic Welfare Conference, 14.08.1944; 12 Briefe zwischen Werner Andreae und Max Horkheimer, 1945-1954; 1 Brief von Julius Marx an Werner Andreae, 10.05.1946, 11.05.1950; 2 Briefe von Josef Messinger an Werner Andreae, 23.10.1946, ohne Datum; 3 Briefe zwischen dem Advokatenbüro Hodler und Max Horkheimer, 1946, 09.05.1946;