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22.
Carlos E. Santos Cecilia Menjívar Rachel A. VanDaalen Olga Kornienko Kimberly A. Updegraff Samantha Cruz 《Ethnic and racial studies》2018,41(9):1672-1690
Bridging diverse areas of inquiry (i.e. legal studies and developmental psychology), this study explored the longitudinal association between Latina/o youths’ burgeoning legal consciousness, measured as awareness of Senate Bill 1070 (SB1070) in Arizona, and their adjustment in school, measured as classroom regulatory behaviours, and examined whether this association varied across immigrant generational status and gender. Participants were 689 Latina/o middle school students in Arizona (Mage?=?12.06 years, SD?=?.98). Multiple regression analysis revealed a significant interaction between Latina/o youths’ awareness of SB1070 at Time 1 and gender in predicting classroom regulatory behaviours at Time 2 (controlling for levels of it at Time 1). Males who were higher on awareness of SB1070 at Time 1 reported lower levels of classroom regulatory behaviours at Time 2. This study underscores the importance of measuring youths’ awareness of laws and how this awareness may impact their academic adjustment. 相似文献
23.
A number of investigators have invoked a cascading local interaction model to account for power‐law‐distributed fluctuations in ecological variables. Invoking such a model requires that species be tightly coupled, and that local interactions among species influence ecosystem dynamics over a broad range of scales. Here we reanalyse bird population data used by Keitt & Stanley (1998, Dynamics of North American breeding bird populations. Nature, 393, 257–260) to support a cascading local interaction model. We find that the power law they report can be attributed to mixing of lognormal distributions. More tentatively, we propose that mixing of distributions accounts for other empirical power laws reported in the ecological literature. 相似文献
24.
中国汉族男性臼齿磨耗与年龄关系的研究 总被引:1,自引:0,他引:1
本文对来自全国九个省区(江西、青海、吉林、河北、安徽、贵州、云南、广西、山东)的262个汉族男性颅骨上的992颗臼齿磨耗,进行了分析研究。探讨了牙齿磨耗的地区差异,提出了臼齿磨耗的新的分级方法。求出了M_1M_2在不同数目组合情况下,推算尸骨年龄的多个回归方程。 相似文献
25.
Antony H. Melcher Stephanie Holowka Michael Pharoah Peter K. Lewin 《American journal of physical anthropology》1997,103(3):329-340
A second CT scan of the mummy Djedmaatesankh, which is housed in the Royal Ontario Museum, Toronto, Ontario, has been undertaken after an interval of some 15 years. The image data set of her dentition and the associated tissues acquired from 3 mm thick × 3 mm spacing slices was transferred to an ISG Allegro work station where two-dimensional reformats and three-dimensional reconstructions were produced. This non-invasive examination provided information on dental disease that is, in a number of respects, an advance on that which previously could be obtained from mummies by the traditional methods of visual inspection after unwrapping and by two-dimensional radiography. The two- and three-dimensional images reveal that: three molars are missing and the right maxillary canine is impacted; the rest of the dentition is afflicted by severe attrition, caries and periodontal disease; and, of the 28 teeth present in the mouth, 24 exhibit exposure of their dental pulps and 18 are afflicted by periapical lesions including five that could have contributed to a large secondarily infected radicular cyst. The cyst has displaced the maxillary antrum and enlarged the maxilla on its lateral aspect and the vault of the palate on its medial aspect. Pus from the cyst may have drained through five different sinuses. In life, Djedmaatesankh's widespread dental infection probably caused her considerable pain, personal distress and malaise, and possibly resulted in her death. Am J Phys Anthropol 103:329–340, 1997. © 1997 Wiley-Liss, Inc. 相似文献
26.
Joel Press 《Biology & philosophy》2009,24(3):359-374
Philosophers intent upon characterizing the difference between physics and biology often seize upon the purported fact that
physical explanations conform more closely to the covering law model than biological explanations. Central to this purported
difference is the role of laws of nature in the explanations of these two sciences. However, I argue that, although certain
important differences between physics and biology can be highlighted by differences between physical and biological explanations,
these differences are not differences in the degree to which those explanations conform to the covering law model, which fits
biology about as well as it does physics. 相似文献
27.
We consider the long lived pool of B and T cells that recirculate through blood, tissues and the lymphatic system of an animal with body mass M. We derive scaling rules (allometric relations) for: (1) the rate of production of mature lymphocytes, (2) the accumulation of lymphocytes in the tissues, (3) the flux of lymphocytes through the lymphatic system, (4) the number of lymph nodes, (5) the number of lymphocytes per clone within a lymph node, and (6) the total number of lymphocytes within a lymph node. Mass-dependent aspects of immune learning and of the immunological self are shown to be not very significant. Our treatment is somewhat heuristic and aims at combining immunological data with recent progress in biological scaling. 相似文献
28.
以青藏高原两种生境(阴坡和阶地)和4个斑块大小等级水平(等级1:0.2—0.6m2,G1;等级2:0.6—2 m2,G2;等级3:2—3.6 m2,G3和等级4:3.6—8.6 m2,G4)的火绒草(Leontopodium nanum)群落为对象,利用幂乘方法则,分析了其种群和群落空间异质性和群落物种多样性特征,明晰了优势种、亚优势种、伴生种和偶见种对其植被分布格局的影响。结果表明:各火绒草斑块的群落空间分布格局均呈集群分布,植物种的随机出现频率和实际出现频率的方差对数值与其幂乘方法吻合性较高(R2﹥0.8),幂乘方法能对火绒草斑块植被空间分布格局进行客观分析。优势种火绒草和线叶嵩草(Kobresia capillifolia),亚优势种球花蒿(Artemisia smithii)和珠芽蓼(Polygonum viviparum)等的相对空间异质性(ε)高于群落的空间异质性(δC),位于直线y=0上方,使群落趋于集群分布;伴生种西北针茅(Stipa krylovii)、瑞香狼毒(Stellera chamaejasme)和苔草(Carex sp)等的ε与群落的δC类似,位于直线y=0附近,它们维持群落自身空间分布状态;偶见种的ε低于群落的δC,位于直线y=0下方,降低群落的集群分布。随火绒草斑块等级水平的增加,群落物种数呈增加,丰富度指数DGI呈降低变化。一般火绒草斑块的δc和βw为阶地﹥阴坡,DGI为阶地﹤阴坡;两种生境下,植物种组成的相似性G1斑块较低,G2—G4斑块较高。火绒草斑块的群落分布格局主要由优势种和亚优势种及偶见种的ε决定。 相似文献
29.
The possible implications of variations in dental attrition patterns have necessitated a detailed assessment of the types, ranges, and causes of tooth wear. Hear we employ measurements of postcanine occlusal wear facets from a sample population of extant Australian aborigines. A principal components analysis was applied as a tool in determining common types of attritional patterns. It was concluded that the range of intrapopulational variation in dental wear patterns must be attributed to a multiplicity of sources in addition to such commonly cited causes as dietary variations, gender, age, and developmental eruption sequences. 相似文献
30.
AbstractFaunal skeletal profiles from archaeological assemblages have been long analysed regarding differential transport of carcasses to infer hunting preferences, human mobility, or even dietary stress. However, the existence of several possible accumulating agents, together with the effect of bone attrition, is known to introduce a potential bias, thus hindering the possibilities of meaningful concussions. In order to overcome this problem, several methods were proposed during the late 90s and early 2000’s, although a consensus was not reached, mainly because the different approaches were based on a certain initial hypothesis that significantly affected the output. Building on that previous experience, a new methodological framework is proposed and compared here. Moving from rather deterministic techniques, a Bayesian alternative approach based on a Monte Carlo Markov Chain sampling is presented and applied to several ethnographic and Pleistocene key sites. This new method makes use of the available information to constrain the possible degrees of attrition and carcass processing strategies, leading to easily comparable results. 相似文献