24 research outputs found
First cohomology for finite groups of Lie type: simple modules with small dominant weights
Let be an algebraically closed field of characteristic , and let
be a simple, simply connected algebraic group defined over .
Given , set , and let be the corresponding
finite Chevalley group. In this paper we investigate the structure of the first
cohomology group where is the
simple -module of highest weight . Under certain very mild
conditions on and , we are able to completely describe the first
cohomology group when is less than or equal to a fundamental dominant
weight. In particular, in the cases we consider, we show that the first
cohomology group has dimension at most one. Our calculations significantly
extend, and provide new proofs for, earlier results of Cline, Parshall, Scott,
and Jones, who considered the special case when is a minimal nonzero
dominant weight.Comment: 24 pages, 5 figures, 6 tables. Typos corrected and some proofs
streamlined over previous versio
Second cohomology for finite groups of Lie type
Let be a simple, simply-connected algebraic group defined over
. Given a power of , let
be the subgroup of -rational points. Let be the
simple rational -module of highest weight . In this paper we
establish sufficient criteria for the restriction map in second cohomology
to be an
isomorphism. In particular, the restriction map is an isomorphism under very
mild conditions on and provided is less than or equal to a
fundamental dominant weight. Even when the restriction map is not an
isomorphism, we are often able to describe in
terms of rational cohomology for . We apply our techniques to compute
in a wide range of cases, and obtain new
examples of nonzero second cohomology for finite groups of Lie type.Comment: 29 pages, GAP code included as an ancillary file. Rewritten to
include the adjoint representation in types An, B2, and Cn. Corrections made
to Theorem 3.1.3 and subsequent dependent results in Sections 3-4. Additional
minor corrections and improvements also implemente
Assessing the cost of global biodiversity and conservation knowledge
Knowledge products comprise assessments of authoritative information supported by stan-dards, governance, quality control, data, tools, and capacity building mechanisms. Considerable resources are dedicated to developing and maintaining knowledge productsfor biodiversity conservation, and they are widely used to inform policy and advise decisionmakers and practitioners. However, the financial cost of delivering this information is largelyundocumented. We evaluated the costs and funding sources for developing and maintain-ing four global biodiversity and conservation knowledge products: The IUCN Red List ofThreatened Species, the IUCN Red List of Ecosystems, Protected Planet, and the WorldDatabase of Key Biodiversity Areas. These are secondary data sets, built on primary datacollected by extensive networks of expert contributors worldwide. We estimate that US116–204 million), plus 293 person-years of volunteer time (range: 278–308 person-years) valued at US12–16 million), were invested inthese four knowledge products between 1979 and 2013. More than half of this financingwas provided through philanthropy, and nearly three-quarters was spent on personnelcosts. The estimated annual cost of maintaining data and platforms for three of these knowl-edge products (excluding the IUCN Red List of Ecosystems for which annual costs were notpossible to estimate for 2013) is US6.2–6.7 million). We esti-mated that an additional US12 million. These costs are much lower than those tomaintain many other, similarly important, global knowledge products. Ensuring that biodi-versity and conservation knowledge products are sufficiently up to date, comprehensiveand accurate is fundamental to inform decision-making for biodiversity conservation andsustainable development. Thus, the development and implementation of plans for sustain-able long-term financing for them is critical
Effect of Cocaine Use on Bone Marrow-mediated Erythropoiesis
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74116/1/aemj.10.7.705.pd
An anatomic transcriptional atlas of human glioblastoma.
Glioblastoma is an aggressive brain tumor that carries a poor prognosis. The tumor\u27s molecular and cellular landscapes are complex, and their relationships to histologic features routinely used for diagnosis are unclear. We present the Ivy Glioblastoma Atlas, an anatomically based transcriptional atlas of human glioblastoma that aligns individual histologic features with genomic alterations and gene expression patterns, thus assigning molecular information to the most important morphologic hallmarks of the tumor. The atlas and its clinical and genomic database are freely accessible online data resources that will serve as a valuable platform for future investigations of glioblastoma pathogenesis, diagnosis, and treatment
Assessing the Cost of Global Biodiversity and Conservation Knowledge
<div><p>Knowledge products comprise assessments of authoritative information supported by standards, governance, quality control, data, tools, and capacity building mechanisms. Considerable resources are dedicated to developing and maintaining knowledge products for biodiversity conservation, and they are widely used to inform policy and advise decision makers and practitioners. However, the financial cost of delivering this information is largely undocumented. We evaluated the costs and funding sources for developing and maintaining four global biodiversity and conservation knowledge products: The IUCN Red List of Threatened Species, the IUCN Red List of Ecosystems, Protected Planet, and the World Database of Key Biodiversity Areas. These are secondary data sets, built on primary data collected by extensive networks of expert contributors worldwide. We estimate that US116–204 million), plus 293 person-years of volunteer time (range: 278–308 person-years) valued at US12–16 million), were invested in these four knowledge products between 1979 and 2013. More than half of this financing was provided through philanthropy, and nearly three-quarters was spent on personnel costs. The estimated annual cost of maintaining data and platforms for three of these knowledge products (excluding the IUCN Red List of Ecosystems for which annual costs were not possible to estimate for 2013) is US6.2–6.7 million). We estimated that an additional US12 million. These costs are much lower than those to maintain many other, similarly important, global knowledge products. Ensuring that biodiversity and conservation knowledge products are sufficiently up to date, comprehensive and accurate is fundamental to inform decision-making for biodiversity conservation and sustainable development. Thus, the development and implementation of plans for sustainable long-term financing for them is critical.</p></div
Categories, subcategories and funding sources classification used to categorise costs.
<p>Categories, subcategories and funding sources classification used to categorise costs.</p