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1.
Mehmet Yaar can Morton H. Kessel Susanna Marits 《American journal of physical anthropology》1989,79(4):483-488
Technological advances have resulted in the development of an additional approach to determining the dietary practices of prehistoric populations. Bones are known to retain certain trace elements, the analysis of which should yield valuable clues to subsistence. Since there has never been a study of this nature attempted on Indian remains in Florida, a qualitative trace element analysis, using an optical emission spectrograph, was made of bone samples from indigenous populations representing both inland and coastal environments in this region. Results of this study showed that magnesium was present in all samples, copper was present in nearly half the samples, and manganese and zinc were not detected. Thus, although the diets of these groups may have varied, the trace element content did not reflect significant differences as have been reported for other types of analyses on Indian populations from diverse geographic regions. 相似文献
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Statistical analysis of one eastern and two western Virginia Indian skeletal samples reveals a general association between geographical and biological distance. However, the data suggest the importance of gene flow as a factor in minimizing local microdifferentiation. Females appear to contribute a disproportionate share to gene flow. This may be attributed to the widespread and apparently frequent practice of acquiring females and children through capture during recurring warfare. 相似文献
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发育生物学探究式教学探讨 总被引:7,自引:1,他引:6
发育生物学是目前生物科学中发展较迅速、应用前景较广阔的学科之一。目前作为本科生的重要专业选修课程, 其授课内容的前沿化对传统的教学模式提出了挑战。文章主要讨论了发育生物学的教学现状, 详细阐述了首都师范大学引用英文原文文献特别是诺贝尔奖获奖者经典文献进行教学的情况, 总结了学生在课堂上做报告以及课下参与网络讨论的模式相结合的优势, 并就如何进一步有效地提高教学质量提出了一些建议。 相似文献
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《Matrix biology》2016
The skeleton is unique from all other tissues in the body because of its ability to mineralize. The incorporation of mineral into bones and teeth is essential to give them strength and structure for body support and function. For years, researchers have wondered how mineralized tissues form and repair. A major focus in this context has been on the role of the extracellular matrix, which harbors key regulators of the mineralization process. In this introductory minireview, we will review some key concepts of matrix biology as it related to mineralized tissues. Concurrently, we will highlight the subject of this special issue covering many aspects of mineralized tissues, including bones and teeth and their associated structures cartilage and tendon. Areas of emphasis are on the generation and analysis of new animal models with permutations of matrix components as well as the development of new approaches for tissue engineering for repair of damaged hard tissue. In assembling key topics on mineralized tissues written by leaders in our field, we hope the reader will get a broad view of the topic and all of its fascinating complexities. 相似文献
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Temporal aspects of biological distance: serial correlation and trend in a prehistoric skeletal lineage 总被引:1,自引:0,他引:1
L W Konigsberg 《American journal of physical anthropology》1990,82(1):45-52
A number of previous studies have examined biological variability within individual human skeletal samples, using internal chronology as an explanatory source for variation. In this paper time series and matrix comparison methods are used to examine temporal serial correlation and trend of biological characteristics within a skeletal sample. These methods follow appropriately upon the assumption that the processes of genetic drift and migration lead to temporal autocorrelation of the mean genotype within individual genetic lineages. In the current analysis, using skeletal material from the Pete Klunk Mound Group, temporal serial correlation is demonstrated between samples from different mounds. This indicates that a previous provisional archaeological ordering of the mounds is probably correct. Absence of temporal trend for any of the nonmetric traits examined here suggests a lack of directional evolutionary forces operating on these traits. 相似文献
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NELSON RAMIREZ YSALENY BRITO 《Botanical journal of the Linnean Society. Linnean Society of London》1992,110(4):277-302
RAMIREZ, N. & BRITO, Y., 1992. Pollination biology in a palm swamp community in the Venezuelan central plains. In a palm swamp community that differs strongly from the surrounding savanna in the Venezuelan central plains, the pollination and floral biology of 33 plant species were studied during three years: 1983, 1984 and 1989. The most frequent flower colours were white, pink, yellow, and in a lesser proportion green, brown, purple and red. Floral symmetry was found in roughly equal proportion for actinomorphic and zygomorphic flowers. Most flowers were short-lived (6–12 hours); in monoecious species the female flowers were longer-lived than the male flowers. The most frequent rewards were pollen and nectar (36.4%) and pollen (30.3%). At the community level, bee- and wasp-pollination prevailed in 57.1% of plant species studies, followed by wind- (14.3%), fly- (11.4%), butterfly- (8.6%), bird- (5.7%) and beetle-pollination (2.9%). Between one and five plant species were simultaneously visited by the visitor species. The vast majority of the pollinating species displayed a high degree of load specificity: 26 pollinator species (65.0%) carried pollen from only one plant species, eight (20.0%,) carried pollen from two plant species, three (7.5%) carried pollen from three plant species and one (2.5%) carried pollen from five plant species. Visitor specificity and pollen transportation were similar amongst the visiting agents. Plant pollination-system specificity and pollen transportation were statistically significant among plant species with different pollinator types, but plant pollination system and pollen transportation were not different among floral symmetry, floral longevity, reward type, plant sexuality, breeding system and plant life form. The visitor species/plant species ratio was 1.6, and the pollinator species/ plant species ratio was 1.3. Among different guilds, birds, Coleoptera and Lepidoptera showed the highest pollinator species/plant species ratio, and wind pollination exhibited the lowest. 相似文献
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Systems biology seeks to explain complex biological systems, such as the cell, through the integration of many different types of information. Here, we discuss how the incorporation of high-resolution structural data can provide key molecular details often necessary to understand the complex connection between individual molecules and cell behavior. We suggest a process of zooming on the cell, from global networks through pathways to the precise atomic contacts at the interfaces of interacting proteins. 相似文献
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Helder I. Nakaya Bali Pulendran 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2015,370(1671)
Vaccination has been tremendously successful saving lives and preventing infections. However, the development of vaccines against global pandemics such as HIV, malaria and tuberculosis has been obstructed by several challenges. A major challenge is the lack of knowledge about the correlates and mechanisms of protective immunity. Recent advances in the application of systems biological approaches to analyse immune responses to vaccination in humans are beginning to yield new insights about mechanisms of vaccine immunity, and to define molecular signatures, induced rapidly after vaccination, that correlate with and predict vaccine induced immunity. Here, we review these advances and discuss the potential of this systems vaccinology approach in defining novel correlates of protection in clinical trials, and in infection-induced ‘experimental challenge models'' in humans. 相似文献
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Kay Schneitz Robert Sablowski Bertrand Lemieux Ueli Grossniklaus Jim Dunwell Steven Hill Lee Sweetlove Jean-Pierre Metraux Klaus Palme Martin R. McAinsh Bernd Weisshaar Frederic Berger 《Current opinion in plant biology》2001,4(6):463-472
A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in plant biology. 相似文献
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Michael C. Dyle Scott M. Ebert Daniel P. Cook Steven D. Kunkel Daniel K. Fox Kale S. Bongers Steven A. Bullard Jason M. Dierdorff Christopher M. Adams 《The Journal of biological chemistry》2014,289(21):14913-14924
Skeletal muscle atrophy is a common and debilitating condition that lacks an effective therapy. To address this problem, we used a systems-based discovery strategy to search for a small molecule whose mRNA expression signature negatively correlates to mRNA expression signatures of human skeletal muscle atrophy. This strategy identified a natural small molecule from tomato plants, tomatidine. Using cultured skeletal myotubes from both humans and mice, we found that tomatidine stimulated mTORC1 signaling and anabolism, leading to accumulation of protein and mitochondria, and ultimately, cell growth. Furthermore, in mice, tomatidine increased skeletal muscle mTORC1 signaling, reduced skeletal muscle atrophy, enhanced recovery from skeletal muscle atrophy, stimulated skeletal muscle hypertrophy, and increased strength and exercise capacity. Collectively, these results identify tomatidine as a novel small molecule inhibitor of muscle atrophy. Tomatidine may have utility as a therapeutic agent or lead compound for skeletal muscle atrophy. 相似文献
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Cytokines play an important role in the evolution of inflammatory processes. Therefore, they are also key components of the cancer evolution, a disease recognized to depend on chronic inflammation. On the whole, we define cytokinome as the totality of these proteins and their interactions in and around biological cells. Understanding the complex interaction network of cytokines in patients affected from cancers should be very useful both to follow the cancer evolution from its early steps and to define innovative therapeutic strategies by using systems biology approaches. 相似文献
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Recent advances in applied physics and chemistry have led to the development of novel microfluidic systems. Microfluidic systems allow minute amounts of reagents to be processed using μm-scale channels and offer several advantages over conventional analytical devices for use in biological sciences: faster, more accurate and more reproducible analytical performance, reduced cell and reagent consumption, portability, and integration of functional components in a single chip. In this review, we introduce how microfluidics has been applied to biological sciences. We first present an overview of the fabrication of microfluidic systems and describe the distinct technologies available for biological research. We then present examples of microsystems used in biological sciences, focusing on applications in molecular and cellular biology. 相似文献
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越冬地东方白鹳繁殖生物学的初步研究 总被引:2,自引:0,他引:2
近年来,陆续在长江中下游越冬地发现东方白鹳(Ciconia boyciana)繁殖个体。为了了解该种在当地的繁殖对策和种群现状,2004-2006年在安庆市望江县武昌湖地区(116°51.15′-116°49.47′E,30°19.53′-30°19.79′N)对东方白鹳的繁殖生物学进行了研究。东方白鹳在当地开始营巢时间不一致,最早为2月5日,而受干扰的繁殖个体则延至5月6日。观察到的巢全在高压线塔上,巢高34.6±0.8m(n=11),巢间距908.8±1039.4m(n=6)。产卵期最早开始于2月11日,最晚6月21日,窝卵数4.2±0.4(4-5)枚(n=6)。育雏期71.0±16.1d(n=3),日育雏5.1±2.6(n=38),雏鸟离巢时间最早6月14日,最晚9月20日。2004和2005年东方白鹳在该地区共营巢8窝,产卵25枚,孵出雏鸟9只,出飞7只。繁殖失败5巢,其中,人工干扰造成4巢失败,高压电击毁1巢。繁殖不同时期,亲鸟的觅食、休息、警戒、取材、翻卵、育雏、交配、在巢、视野外行为时间分配差异显著,而飞翔、行走、理羽、击喙、整巢和其它行为差异不显著。雏鸟在发育的不同时期,觅食、飞翔、休息、整巢、在巢、行走、视野外行为时间分配差异显著,理羽、警戒、击喙和其它行为差异不显著 相似文献
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S Helm 《American journal of physical anthropology》1979,51(3):345-352
Skeletal maturity was assessed from hand-wrist radiographs in a sample of 3,817 Danish schoolchildren aged 7 to 18 years using the new version of the bone-specific Tanner-Whitehouse scoring system, the TW2 method. In most of the age groups in both sexes the distributions of the bone maturity scores displayed marked departures from normality; percentiles for the scores were therefore counted from the raw data. On the average, over the total age range, the differences between the age equivalents (bone ages) for the fiftieth percentile and chronological age were close to zero in both sexes, indicating good agreement with the British standards. However, in the individual age groups, and in particular at adolescence, characteristic divergences from the standards occurred, apparently reflecting the developmental spurt. 相似文献
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Changes in the biosciences and their relations to society over the last decades provide a unique opportunity to examine whether or not such changes leave traces in the language we use to talk about them. In this article we examine metaphors used in English-speaking press coverage to conceptualize a new type of (interdisciplinary) bioscience: synthetic biology. Findings show that three central metaphors were used between 2008 and May 2010. They exploit social and cultural knowledge about books, computers and engines and are linked to knowledge of three revolutions in science and society (the printing, information and industrial revolutions). These three central metaphors are connected to each other through the concepts of reading/writing, designing and mass production and they focus on science as a revolutionary process rather than on the end results or products of science. Overall, we observed the use of a complex bricolage of mixed metaphors and chains of metaphors that root synthetic biology in historical events and achievements, while at the same time extolling its promises for the future. 相似文献
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Alison Galloway Mary Ellen Morbeck Adrienne L. Zihlman 《Primates; journal of primatology》1996,37(4):443-455
Male and female chimpanzees from Gombe National Park, Tanzania (Pan troglodytes schweinfurthii) differ in live body weights but not in cranial capacity or fore-and hindlimb long bone lengths. Skeletal dimensions of the
limbs and vertebral column indicate a mosaic of sex differences. Vertebral column measurements generally are greater in males.
While linear measurements identify differences in the breadth and depth of the lower cervical and upper thoracic vertebrae,
areal assessments show significant differences in weight-bearing surfaces throughout the thoracic and lumbar segments. These
can be interpreted in terms of distribution of weight and body composition (i.e. amount of musculature). 相似文献
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失重条件下人和动物生理状态会发生一系列的变化,其中骨骼肌萎缩和力量下降较为显著,目前其发生的机制仍不明确且缺少特效的干预措施。本文从肌肉湿重及肌纤维横截面积的变化、肌纤维类型的变化、肌纤维超微结构的变化、肌梭的适应性变化四个方面进行简要阐述,探讨肌肉萎缩的可能发生机制。 相似文献