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151.
152.
The mammalian circadian clock lying in suprachiasmatic nucleus (SCN) is synchronized to about 24 h by the environmental light-dark cycle (LD). The circadian clock exhibits limits of entrainment above and below 24 h, beyond which it will not entrain. Little is known about the mechanisms regulating the limits of entrainment. In this study, we show that wild-type mice entrain to only an LD 24 h cycle, whereas Clock mutant mice can entrain to an LD 24, 28, and 32 h except for LD 20 h and LD 36 h cycle. Under an LD 28 h cycle, Clock mutant mice showed a clear rhythm in Per2 mRNA expression in the SCN and behavior. Light response was also increased. This is the first report to show that the Clock mutation makes it possible to adapt the circadian oscillator to a long period cycle and indicates that the clock gene may have an important role for the limits of entrainment of the SCN to LD cycle.  相似文献   
153.
Pulse train intervals (PTI) of courtship song were differentiated between circadian clock mutants of the melon fly, Bactrocera cucurbitae (Coquillett) (Tephritidae: Diptera). We analysed the male mating song of B. cucurbitae flies of two mutant strains that differed in circadian locomotor rhythm by a LabVIEW programming system. Flies with a short circadian rhythm (S-strain) had shorter PTI than those with a long circadian rhythm (L-strain) in the two age groups tested, young and old. Young flies showed longer PTI than old flies, but no interaction between strain and age was found in PTI. There was a significant interaction between strain and age for pulse train duration (PTD), whereas no stable difference was found in PTD between S- and L-strains. These results suggest a positive correlation between the length of the circadian locomotor rhythm and PTI of courtship song sounds in B. cucurbitae.  相似文献   
154.
心肌细胞团搏动的整数倍节律的实验观察   总被引:3,自引:3,他引:0  
实验报道了心肌细胞团自发性同步化搏动的一类新节律——整数倍节律。这种稳定的节律模式由两种相关的搏动形式的随机交替出现形成,这两种搏动形式中任何一种的出现间期具有整数倍特征。在静息状态和周期1搏动间的随机交替形成0-1整数倍节律,在周期1搏动和周期2搏动之间的随机交替形成l-2整数倍节律。0-1整数倍是居于静息状态和周期1节律之间的节律模式,1-2整数倍是居于周期1节律和周期2节律之间的节律模式,实验所见的节律转迁过程清楚地展示了静息状态、0-1整数倍节律、周期1节律、1-2整数倍节律、周期2节律等顺序地构成的一种“节律谱系”。“节律谱系”的观念可以为认识正常和异常心律的关系和其间的转迁机制提供深刻的理论启示。  相似文献   
155.
快速康复外科(fast track surgery,FTS)是胃肠道肿瘤围手术期护理发展的新趋势,它全面改变了胃肠外科的面貌,并且对传统护理学形成强烈冲击,传统的护理模式已无法适应现代FTS的发展。本文对近年来FTS在胃肠道肿瘤围手术期的护理进行综述,并结合临床工作实践,探讨目前护理理念的转变,并对未来的胃肠道肿瘤围手术期的护理模式进行展望。  相似文献   
156.
《Cancer epidemiology》2014,38(3):253-258
BackgroundSurvival from most cancers in Estonia has been consistently below European average. The objective of this study was to examine recent survival trends in Estonia and to quantify the effect on survival estimates of the temporary disruption of the Estonian Cancer Registry (ECR) practices in 2001–2007 when death certificates could not be used for case ascertainment.Patients and methodsECR data on all adult cases of 16 common cancers diagnosed in Estonia during 1995–2008 and followed up for vital status until 2009 were used to estimate relative survival ratios (RSR). We used cohort analysis for patients diagnosed in 1995–1999 and 2000–2004; and period hybrid approach to obtain the most recent estimates (2005–2009). We compared five-year RSRs calculated from data sets with and without death certificate initiated (DCI) cases.ResultsA total of 64 328 cancer cases were included in survival analysis. Compared with 1995–1999, five-year age-standardized RSR increased 20 percent units for prostate cancer, reaching 76% in 2005–2009. A rise of 10 percent units or more was also seen for non-Hodgkin lymphoma (five-year RSR 51% in 2005–2009), and cancers of rectum (49%), breast (73%) and ovary (37%). The effect of including/excluding DCI cases from survival analysis was small except for lung and pancreatic cancers.ConclusionsRelative survival continued to increase in Estonia during the first decade of the 21st century, although for many cancers, a gap between Estonia and more affluent countries still exists. Cancer control efforts should aim at the reduction of risk factors amenable to primary prevention, but also at the improvement of early diagnosis and ensuring timely and optimal care to all cancer patients.  相似文献   
157.
Individuals living in the San Pedro de Atacama oases and the neighboring upper Loa River Valley of northern Chile experienced the collapse of an influential foreign polity, environmental decline, and the appearance of a culturally distinct group during the Late Intermediate Period (ca. AD 1,100–1,400). We investigate cultural heterogeneity at the Loa site of Caspana through analyses of strontium and oxygen isotopes, cranial modification styles, and mortuary behavior, integrating biological aspects of identity, particularly geographic origins, with cultural aspects of identity manifested in body modification and mortuary behavior. We test the hypothesis that the Caspana population (n = 66) represents a migrant group, as supported by archeological and ethnographic evidence, rather than a culturally distinct local group. For Caspana archeological human tooth enamel, mean 87Sr/86Sr = 0.70771 ± 0.00038 (1σ, n = 30) and mean δ18Oc(V‐PDB) = ?3.9 ± 0.6‰ (1σ, n = 16); these isotopic data suggest that only one individual lived outside the region. Material culture suggests that the individuals buried at Caspana shared some cultural affinity with the San Pedro oases while maintaining distinct cultural traditions. Finally, cranial modification data show high frequencies of head shaping [92.4% (n = 61/65)] and an overwhelming preference for annular modification [75.4% (n = 46/61)], contrasting sharply with practices in the San Pedro area. Based on multiple lines of evidence, we argue that, rather than representing a group of altiplano migrants, the Caspana population existed in the region for some time. However, cranial modification styles and mortuary behavior that are markedly distinct from patterns in surrounding areas raise the possibility of cultural heterogeneity and cultural fissioning. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.  相似文献   
158.
张雅军  张旭 《人类学学报》2021,40(6):981-992
本文通过对新疆且末县托乎拉克勒克乡加瓦艾日克村29座墓地出土的人骨标本进行了观察和分析。共鉴定出150例个体,其中男性73例、女性50例、性别不明者27例。男性、女性平均死亡年龄分别为36.3岁和35.6岁。形态学的分析指出且末人群更多地具有欧洲人种的特点,如鼻根凹陷深、鼻骨明显突起及犬齿窝深等。聚类分析结果显示且末人群与新疆古代人群焉布拉克C组、察吾呼四号组、多岗等人群较为接近。文章还根据线粒体DNA的分析结果讨论了且末古代人群的种族属性,古DNA的分析揭示出且末人群存在欧亚大陆东、西部人群的基因交流,并进一步指出其西部类型的成分来源极有可能来自西伯利亚,其东部成分可能来自西伯利亚或中国甘肃,只是东西方人群的基因融合规模小而且处于初级阶段,所以并未在颅面部形态特征上有大规模明显的改变。此外,本文从考古学文化、体质人类学研究以及古DNA等几个方面探讨了新疆地区古代人群的种族成分来源。本文还对且末人群的身高进行了推算,对一例变形颅骨以及骨骼上的创伤作了简要描述。  相似文献   
159.
Summary The overall efficiency of insecticides with various egg, nymph and adult efficacy for brown planthopper control were analyzed using a simulation approach. Insecticides which have high nymphal efficacy are most effective. Nymphal efficacy contributes up to 71% of the potential efficiency while ovicidal efficacy contributes the remaining 29%. Adult efficacy alone appears to have negligible effects. Long residual efficacy provides better control, however, the increase in efficiency is not directly proportional to the residual period of the insecticide. A residual period of 10 to 15 days would suffice for BPH control.  相似文献   
160.
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