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991.
Williams JM Lonsdorf EV Wilson ML Schumacher-Stankey J Goodall J Pusey AE 《American journal of primatology》2008,70(8):766-777
Understanding the rates and causes of mortality in wild chimpanzee populations has important implications for a variety of fields, including wildlife conservation and human evolution. Because chimpanzees are long-lived, accurate mortality data requires very long-term studies. Here, we analyze 47 years of data on the Kasekela community in Gombe National Park. Community size fluctuated between 38 and 60, containing 60 individuals in 2006. From records on 220 chimpanzees and 130 deaths, we found that the most important cause of mortality in the Kasekela community was illness (58% of deaths with known cause), followed by intraspecific aggression (20% of deaths with known cause). Previous studies at other sites also found that illness was the primary cause of mortality and that some epidemic disease could be traced to humans. As at other study sites, most deaths due to illness occurred during epidemics, and the most common category of disease was respiratory. Intraspecific lethal aggression occurred within the community, including the killing of infants by both males and females, and among adult males during the course of dominance-related aggression. Aggression between communities resulted in the deaths of at least five adult males and two adult females in the Kasekela and Kahama communities. The frequency of intercommunity violence appears to vary considerably among sites and over time. Intercommunity lethal aggression involving the Kasekela community was observed most frequently during two periods. Other less common causes of death included injury, loss of mother, maternal disability, and poaching. 相似文献
992.
Cooksey RC Jhung MA Yakrus MA Butler WR Adékambi T Morlock GP Williams M Shams AM Jensen BJ Morey RE Charles N Toney SR Jost KC Dunbar DF Bennett V Kuan M Srinivasan A 《Applied and environmental microbiology》2008,74(8):2480-2487
Between March and May 2006, a Texas hospital identified five Mycobacterium mucogenicum bloodstream infections among hospitalized oncology patients using fluorescence high-performance liquid chromatography analysis of mycolic acids. Isolates from blood cultures were compared to 16 isolates from environmental sites or water associated with this ward. These isolates were further characterized by hsp65, 16S rRNA, and rpoB gene sequencing, hsp65 PCR restriction analysis, and molecular typing methods, including repetitive element PCR, random amplified polymorphic DNA PCR, and pulsed-field gel electrophoresis (PFGE) of large restriction fragments. Three of five patient isolates were confirmed as M. mucogenicum and were in a single cluster as determined by all identification and typing methods. The remaining two patient isolates were identified as different strains of Mycobacterium phocaicum by rpoB sequence analysis. One of these matched an environmental isolate from a swab of a hand shower in the patient's room, while none of the clinical isolates of M. mucogenicum matched environmental strains. Among the other 15 environmental isolates, 11 were identified as M. mucogenicum and 4 as M. phocaicum strains, all of which were unrelated by typing methods. Although the 16S rRNA gene sequences matched for all 14 M. mucogenicum isolates, there were two each of the hsp65 and rpoB sequevars, seven PCR typing patterns, and 12 PFGE patterns. Among the seven M. phocaicum isolates were three 16S rRNA sequevars, two hsp65 sequevars, two rpoB sequevars, six PCR typing patterns, and six PFGE patterns. This outbreak represents the first case of catheter-associated bacteremia caused by M. phocaicum and the first report of clinical isolates from a U.S. hospital. The investigation highlights important differences in the available typing methods for mycobacteria and demonstrates the genetic diversity of these organisms even within narrow confines of time and space. 相似文献
993.
The aim of the present study was to compare the classical parathyroid hormone/parathyroid hormone-related peptide (PTH/PTHrP) receptors in MCF7 breast cancer cells with SaOS-2 osteosarcoma cell line. Quantitative binding showed that (125)I-PTHrP-1-34(Tyr) binds with a single binding site in both cells. However (125)I-PTHrP-1-34(Tyr) has higher affinity binding in MCF7 (K(D) = 1.88 +/- 0.08 nM) than in SaOS-2 cells (K(D) = 4.4 +/- 0.185 nM). The competitive binding using 3.3 nM (125)I-PTHrP-1-34(Tyr) with increasing amounts (0.33-33 nM) of unlabelled human PTHrP-1-34, PTHrP-7-34, PTHrP-1-86 His(5)-PTHrP-1-36, His(5)-Phe(23)-PTHrP-1-36 or PTH-1-34 revealed different displacements. In SaOS-2 the PTHrP-7-34 and PTHrP-1-86 caused similar displacement compared with 73% by PTH-1-34 and 70% by PTHrP-1-34. However, in MCF7, PTHrP-7-34, PTHrP-1-86 and PTH-1-34 displaced by 54%, 72% and 67%, respectively, compared to 87% by PTHrP-1-34. The His(5)-Phe(23)-PTHrP-1-36 caused an increase in the K(D) from 2.0 +/- 0.03 nM to 2.75 +/- 0.045 nM in MCF7 cells, but had no significant effect in SaOS-2 cells. The PTH/PTHrP receptor in both cell lines revealed a single 85 KDa band with different intensity. Our results suggest that the PTH/PTHrP receptor in MCF7 cells has higher binding affinity for PTHrP than PTH compared to the receptor in SaOS-2 cells. 相似文献
994.
Glycine, a major inhibitory neurotransmitter in the vertebrate nervous system, not only functions in synaptic signaling, but has also been implicated in regulating neuronal differentiation, neuronal proliferation, synaptic modeling, and neural network stability. Elements of the glycinergic phenotype include the membrane-bound glycine transporters (GLYT1 and GLYT2), which remove glycine from the synaptic cleft, and the vesicular inhibitory amino acid transporter (VIAAT or VGAT), which sequesters both glycine and GABA into synaptic vesicles. Here, we describe the spatial and temporal expression patterns of xGlyT1, xGlyT2, and xVIAAT during early developmental stages of Xenopus laevis. In situ hybridization reveals that xGlyT1 is first expressed in early tailbud stages in the midbrain, hindbrain, and anterior spinal cord; it extends posteriorly through the spinal cord and appears in the forebrain, retina, between the somites, and in the blood islands by swimming tadpole stages. xGlyT2 and xVIAAT initially appear in late neurula stages in the anterior spinal cord. By swimming tadpole stages, the expression of these genes appears in the forebrain, midbrain, and hindbrain and extends posteriorly through the spinal cord; xVIAAT is also expressed in the retina. Confocal analysis of multiplex fluorescent in situ hybridization signal in the spinal cord reveals that xGlyT1 and xGlyT2 share little cellular colocalization. While there is significant coexpression between xVIAAT and xGlyT2, xVIAAT and the GABAergic marker glutamic acid decarboxylase (xGAD67), and xGlyT2 and xGAD67, each gene also appears to have discrete, non-colocalized areas of expression. 相似文献
995.
996.
McFall-Ngai M 《Nature reviews. Microbiology》2008,6(10):789-792
The study of symbiosis is quintessential systems biology. It integrates not only all levels of biological analysis--from molecular to ecological--but also the study of the interplay between organisms in the three domains of life. The development of this field is still in its early stages, but so far, the findings promise to revolutionize the way we view the biotic world. This Essay outlines some of the challenges facing the field and the implications of its development for all of biology. 相似文献
997.
Altruism is an evolutionary puzzle. To date, much debate has focused on whether helping others without regard to oneself is a uniquely human behaviour, with a variety of empirical studies demonstrating a lack of altruistic behaviour in chimpanzees even when the demands of behaving altruistically seem minimal. By contrast, a recent experiment has demonstrated that chimpanzees will help a human experimenter to obtain an out-of-reach object, irrespective of whether or not they are offered a reward for doing so, suggesting that the cognitions underlying altruistic behaviour may be highly sensitive to situational demands. Here, we examine the cognitive demands of other-regarding behaviour by testing the conditions under which primates more distantly related to humans--capuchin monkeys--help an experimenter to obtain an out-of-reach object. Like chimpanzees, capuchin monkeys helped human experimenters even in the absence of a reward, but capuchins systematically failed to take into account the perspective of others when they stood to obtain food for themselves. These results suggest an important role for perspective taking and inhibition in altruistic behaviour and seem to reflect a significant evolutionary development in the roots of altruism, and specifically in other-regarding behaviour, between the divergence of New World monkeys and apes. 相似文献
998.
Background
Spinal fusion surgery is currently recommended when curve magnitude exceeds 40–45 degrees. Early attempts at spinal fusion surgery which were aimed to leave the patients with a mild residual deformity, failed to meet such expectations. These aims have since been revised to the more modest goals of preventing progression, restoring 'acceptability' of the clinical deformity and reducing curvature. In view of the fact that there is no evidence that health related signs and symptoms of scoliosis can be altered by spinal fusion in the long-term, a clear medical indication for this treatment cannot be derived. Knowledge concerning the rate of complications of scoliosis surgery may enable us to establish a cost/benefit relation of this intervention and to improve the standard of the information and advice given to patients. It is also hoped that this study will help to answer questions in relation to the limiting choice between the risks of surgery and the "wait and see – observation only until surgery might be recommended", strategy widely used. The purpose of this review is to present the actual data available on the rate of complications in scoliosis surgery.Materials and methods
Search strategy for identification of studies; Pub Med and the SOSORT scoliosis library, limited to English language and bibliographies of all reviewed articles. The search strategy included the terms; 'scoliosis'; 'rate of complications'; 'spine surgery'; 'scoliosis surgery'; 'spondylodesis'; 'spinal instrumentation' and 'spine fusion'.Results
The electronic search carried out on the 1st February 2008 with the key words "scoliosis", "surgery", "complications" revealed 2590 titles, which not necessarily attributed to our quest for the term "rate of complications". 287 titles were found when the term "rate of complications" was used as a key word. Rates of complication varied between 0 and 89% depending on the aetiology of the entity investigated. Long-term rates of complications have not yet been reported upon.Conclusion
Scoliosis surgery has a varying but high rate of complications. A medical indication for this treatment cannot be established in view of the lack of evidence. The rate of complications may even be higher than reported. Long-term risks of scoliosis surgery have not yet been reported upon in research. Mandatory reporting for all spinal implants in a standardized way using a spreadsheet list of all recognised complications to reveal a 2-year, 5-year, 10-year and 20-year rate of complications should be established. Trials with untreated control groups in the field of scoliosis raise ethical issues, as the control group could be exposed to the risks of undergoing such surgery. 相似文献999.
Atriplex nummularia is a polyploid Australian saltbush which has been identified as a suitable species for use in the rehabilitation of agricultural land affected by salinity. We isolated 12 polymorphic loci for a preliminary assessment of genetic variability and structure within the species as a basis for a breeding programme. Preliminary screening of loci in 40 individuals from two populations revealed multibanded genotypes consisting of up to seven alleles in a single individual, with up to 29 alleles observed at a single locus. The multibanded patterns are consistent with the polyploid status of this species. 相似文献
1000.
Objective: This study compared the relationship between fair/poor general health status among overweight and obese Polynesians with that among other overweight and obese persons in Hawaii. Methods and Procedures: Data were pooled from the 1998–2003 Hawaii Behavioral Risk Factor Surveillance System (BRFSS) and logistic regression used to examine the predictors of fair/poor health status. Results: Polynesians were significantly more likely to be obese than non‐Polynesians; overweight Polynesians were more likely than other overweight individuals to report fair/poor health status. After adjusting for confounders, among Polynesians, being obese was no longer associated with fair/poor health. Non‐Polynesians who were obese (odds ratio 1.9; 95% confidence interval: 1.4–2.6), older, less educated, smokers, diabetic, hypertensive, and physically inactive were more likely to report fair/poor health. Discussion: Although Polynesians were significantly more obese than the rest of the Hawaii population, their weight was not independently associated with their odds for fair/poor health as it was with non‐Polynesians. The difference may be that, for Polynesians, hypertension and diabetes overrode the effect of obesity on general health status or this group maintains different cultural perceptions of body size. Regardless, these findings show a major health risk among Polynesians and suggest the need for culturally specific health interventions. 相似文献