Enhancement of low-mt{m_t} kaons in AGS heavy-ion collisions

In the relativistic transport model, we show that the recently observed enhancement of low-$m_t$ kaons ($K^+$ and $K^-$) in Si+Pb collisions at AGS can be explained if a density isomer is introduced in the nuclear equation-of-state.Comment: 12 pages, RevTex, 6 figs on request to [email protected]

Governing Boards and Profound Organizational Change in Hospitals

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69047/2/10.1177_107755878904600204.pd

Mouse Chromosome 11

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46996/1/335_2004_Article_BF00648429.pd

No Evidence for Monoallelic Expression of <i>Gnas</i> and Fourteen Other Genes in the Distal Region of Mouse Chromosome 2

Distal chromosome 2 is one of ten regions of the mouse genome subject to parental imprinting. Maternal duplication/paternal deficiency of distal chromosome 2 leads to hypokinetic mice with long flat-sided bodies and arched backs, which fail to suckle and die within a few hours of birth. The reciprocal type, paternal duplication/maternal deficiency, shows an opposite phenotype: the mice have short square bodies and broad flat backs and are distinctly hyperkinetic [1], The region is defined by the breakpoints of two reciprocal translocations, T(2;8)2Wa and T(2;16)28H, is estimated to be about 7.5 Mb in size and shows linkage conservation with human chromosome 20q13. We have tested for monoallelic expression of a number of candidate genes that are either likely or known to lie within the distal imprinting region. These included three-Cebpb, E2f1 and Tc/f4-that express transcription factors, two-Cyp24 and Pck1-that are involved in growth, six-Acra4, Edn3, Kcnb1, Mc3r, Ntsr and Ppgb-where a defect could lead to neurological and probably behavioural problems, three:-Cd40, Plcg1 and Rcad-that are doubtful candidates but whose sequence was available for testing their expression and finally, Gnas, which is our best candidate because there is clinical and biochemical evidence suggesting that its human homologue, GNAS1, is imprinted. On/off expression of each gene was tested by RT-PCR analysis of RNA extracted from tissues of mice with maternal duplication/paternal deficiency and its reciprocal for the distal region of chromosome 2. None of these genes was monoallelically expressed in the appropriate tissues before and after birth, suggesting that they are not imprinted. Evidence for the imprinting of GNAS1 in humans is based on studies of patients with Albright's hereditary osteodystrophy (AHO) who possess a dysfunctional GNAS1 allele. AHO somatic features together-with resistance to parathyroid hormone and other hormones that act via cAMP occur when the defective allele is inherited from the mother whereas AHO somatic features alone occur in paternally transmitted cases [2]. If genomic imprinting regulates Gnas expression in the mouse, then its effect must be specifically confined to hormone-responsive cells.</jats:p

In Defense of Merit in Science

International audienceMerit is a central pillar of liberal epistemology, humanism, and democracy. The scientific enterprise, built on merit, has proven effective in generating scientific and technological advances, reducing suffering, narrowing social gaps, and improving the quality of life globally. This perspective documents the ongoing attempts to undermine the core principles of liberal epistemology and to replace merit with non-scientific, politically motivated criteria. We explain the philosophical origins of this conflict, document the intrusion of ideology into our scientific institutions, discuss the perils of abandoning merit, and offer an alternative, human-centered approach to address existing social inequalities.</jats:p

Reproductive biology in species of Bidens L. (Asteraceae) Biologia reprodutiva em espécies de Bidens L. (Asteraceae)

Studies about reproductive biology of weed species can have implications on the establishment of controlling practices that minimize the effects of these weed populations on agricultural fields. The pollination biology of Bidens alba (L.) DC., B. pilosa L., and Bidens subalternans DC., was studied at different sites and climatic seasons. Bidens pilosa and B. subalternans are widely distributed in agricultural areas, in disturbed habitats, and along road sides. Bidens alba occur only along the coast. The three species are self-compatible and non agamospermous. The composition of the pollinator community changes during the year and between sites. Hymenopterans and lepidopterans are the most frequent visitors to Bidens species in both areas studied. Although the species are self-compatible, the presence of pollinators may affect the levels of inbreeding. The attraction of insects by Bidens species may be benefical to agricultural crop and may also have important implications for conservation biology.<br>Estudos de biologia reprodutiva de espécies invasoras podem ter implicações sobre o estabelecimento de práticas de controle que minimizem o efeito das populações destas espécies em áreas agrícolas. A biologia da polinização de Bidens alba (L.) DC., B. pilosa L. e Bidens subalternans DC. foi estudada em diferentes locais e estações climáticas. Bidens pilosa e B. subalternans são espécies amplamente distribuídas em áreas agrícolas, em habitats perturbados e em margens de estradas. Bidens alba ocorre somente em regiões litorâneas. As três espécies são auto-compatíveis e não são agamospérmicas. A composição da comunidade de polinizadores apresenta diferenças durante o ano e entre locais. Himenópteros e lepidópteros são os visitantes mais freqüentes nas espécies de Bidens. Embora as espécies sejam auto compatíveis, a presença de polinizadores pode afetar os níveis de endocruzamento. A atração de insetos por espécies de Bidens pode beneficiar as culturas agrícolas e apresentar importantes implicações para a biologia da conservação