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91.
Density-dependent and extrinsic mortality are predicted to accelerate reproductive maturation. The first 5 years of life is a proposed sensitive period for life-history regulation. This study examines the ways in which local mortality during this sensitive period was related to subsequent marriage timing in nineteenth-century Belgium (n women = 11 892; n men = 14 140). Local mortality during the sensitive period was inversely associated with age at first marriage for men and women controlling for literacy, occupational status, population growth and migration. Cox regression indicated decreased time to marriage for women (HR = 1.661, 95% CI: 1.542–1.789) and men (HR = 1.327, 95% CI: 1.238–1.422) from high mortality municipalities. Rising population growth rates were associated with earlier marriage for men and women. Migration in general was associated with later marriage for men and women. Consistent with life-history predictions, harsh ecological conditions during early life such as famine coincided with earlier marriage.  相似文献   
92.
The history of chemical investigations into the yellow components of turmeric can be traced from 1815. Although the major yellow component of turmeric, curcumin, often is represented as a 1,3-diketone in the solid state and in nonaqueous solution, it exists in the enol form. The struggle to identify the chemical structure of curcumin continued for nearly a century and was complicated by the difficult purification of curcumin and by the presence of two additional yellow components. Food remains the main use for turmeric (old spice); its use as a dye has diminished since the 19th century, but it may have pharmaceutical uses (new spice).  相似文献   
93.
Using ontologies to describe mouse phenotypes   总被引:1,自引:1,他引:0  
The mouse is an important model of human genetic disease. Describing phenotypes of mutant mice in a standard, structured manner that will facilitate data mining is a major challenge for bioinformatics. Here we describe a novel, compositional approach to this problem which combines core ontologies from a variety of sources. This produces a framework with greater flexibility, power and economy than previous approaches. We discuss some of the issues this approach raises.  相似文献   
94.
Shallow freshwater aquatic ecosystems are discrete feeding patches for fish eating birds. A unique feature of these ecosystems is that their physical conditions can change dramatically in a short period of time, particularly temperature, turbidity, and dissolved oxygen. Based on previous research we predicted that increasing turbidity will reduce the availability of fish to birds due to reduced visibility, while increasing temperature and decreasing dissolved oxygen will increase their availability through increases in activity and movement towards the more oxygenated surface areas, respectively. We also predicted that overall abundance of fish should increase feeding activity by terns. We measured these environmental variables, bird activity, and fish abundance from May to August from 2006 to 2008 in a marsh in southern Manitoba, Canada. Our results showed that only variation in dissolved oxygen levels affected feeding activity by terns. Since there was no relationship between bird and fish abundance either within or among years, these results suggest that it is the availability of prey (i.e. the upward movement of fish into the water column) and not their abundance per se that influences the number of avian predators present and hence the risk of predation to fish. These data demonstrate how the physical environment of aquatic ecosystems can impact terrestrial avian predators, and the link that exists between the physical environment and predator-prey interactions.  相似文献   
95.
Abstract: The human dopamine D4 receptor (hD4R), which has been implicated in human diseases such as schizophrenia and in a personality trait called "novelty seeking," has not yet been characterized at the protein level. Following epitope scanning of the hD4R, we have produced a highly specific monoclonal antibody named DFR1 raised against an amino-terminal peptide in a predicted extracellular region of the receptor. DFR1 decorated recombinant hD4Rs on the surface of intact Chinese hamster ovary (CHO) cells by flow cytometry and fluorescence microscopy and also recognized recombinant hD4.2, hD4.4, and hD4.7 receptor isoforms by western blot analysis. When expressed stably in CHO cells, all three hD4R isoforms contained N-linked glycosylation and showed apparent molecular masses of 48, 55, and 67 kDa for hD4.2, hD4.4, and hD4.7, respectively. DFR1 immunoreactivity representing hD4R protein or dopamine D4 receptor-like antigens was observed in crude membrane extracts of postmortem human brain tissue by immunoblotting. The DFR1 antibody provides a new immunological tool with the potential to further our understanding of the human dopamine D4 receptor protein.  相似文献   
96.
Since the publication of our article (Roth, Gonnet, and Dessimoz: BMC Bioinformatics 2008 9: 518), we have noticed several errors, which we correct in the following.  相似文献   
97.
98.

Background

Mechanical ventilation (MV) may cause ventilator-induced lung injury (VILI) and may thereby contribute to fatal multiple organ failure. We tested the hypothesis that injurious MV of lipopolysaccharide (LPS) pre-injured lungs induces myocardial inflammation and further dysfunction ex vivo, through calcium (Ca2+)-dependent mechanism.

Materials and methods

N = 35 male anesthetized and paralyzed male Wistar rats were randomized to intratracheal instillation of 2 mg/kg LPS or nothing and subsequent MV with lung-protective settings (low tidal volume (Vt) of 6 mL/kg and 5 cmH2O positive end-expiratory pressure (PEEP)) or injurious ventilation (high Vt of 19 mL/kg and 1 cmH2O PEEP) for 4 hours. Myocardial function ex vivo was evaluated in a Langendorff setup and Ca2+ exposure. Key mediators were determined in lung and heart at the mRNA level.

Results

Instillation of LPS and high Vt MV impaired gas exchange and, particularly when combined, increased pulmonary wet/dry ratio; heat shock protein (HSP)70 mRNA expression also increased by the interaction between LPS and high Vt MV. For the heart, C-X-C motif ligand (CXCL)1 and Toll-like receptor (TLR)2 mRNA expression increased, and ventricular (LV) systolic pressure, LV developed pressure, LV +dP/dtmax and contractile responses to increasing Ca2+ exposure ex vivo decreased by LPS. High Vt ventilation aggravated the effects of LPS on myocardial inflammation and dysfunction but not on Ca2+ responses.

Conclusions

Injurious MV by high Vt aggravates the effects of intratracheal instillation of LPS on myocardial dysfunction, possibly through enhancing myocardial inflammation via pulmonary release of HSP70 stimulating cardiac TLR2, not involving Ca2+ handling and sensitivity.  相似文献   
99.
beta-Lapachone (beta-lap) induces apoptosis in various cancer cells, and its intracellular target has recently been elucidated in breast cancer cells. Here we show that NAD(P)H:quinone oxidoreductase (NQO1/xip3) expression in human prostate cancer cells is a key determinant for apoptosis and lethality after beta-lap exposures. beta-Lap-treated, NQO1-deficient LNCaP cells were significantly more resistant to apoptosis than NQO1-expressing DU-145 or PC-3 cells after drug exposures. Formation of an atypical 60-kDa PARP cleavage fragment in DU-145 or PC-3 cells was observed after 10 microM beta-lap treatment and correlated with apoptosis. In contrast, LNCaP cells required 25 microM beta-lap to induce similar responses. Atypical PARP cleavage in beta-lap-treated cells was not affected by 100 microM zVAD-fmk; however, coadministration of dicoumarol, a specific inhibitor of NQO1, reduced beta-lap-mediated cytotoxicity, apoptosis, and atypical PARP cleavage in NQO1-expressing cells. Dicoumarol did not affect the more beta-lap-resistant LNCaP cells. Stable transfection of LNCaP cells with NQO1 increased their sensitivity to beta-lap, enhancing apoptosis compared to parental LNCaP cells or vector-alone transfectants. Dicoumarol increased survival of beta-lap-treated NQO1-expressing LNCaP transfectants. NQO1 activity, therefore, is a key determinant of beta-lap-mediated apoptosis and cytotoxicity in prostate cancer cells.  相似文献   
100.
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