共查询到20条相似文献,搜索用时 15 毫秒
1.
Kirstin Lewis 《Ethnic and racial studies》2013,36(12):2065-2083
This research aims to explore the school experiences of mixed white/ black Caribbean children in English schools. The overarching findings of this research confirm that although the mixed-race population as a whole is achieving above the national average, the mixed white/ black Caribbean group is consistently the lowest performing mixed-race group in the country. Views of pupils, their parents and teachers in two London secondary schools suggest various reasons why mixed white/ black Caribbean pupils might continue to be the lowest performing mixed group in the country. These included experiences of marginalization and invisibility in school life, the low expectations that teachers held about them, the lack of knowledge about how to support them at school and how all these issues were exacerbated by the friendship groups they mixed in. This research paper discusses these critical factors in detail and their implications for policy and further research. 相似文献
2.
Black spaces,black places: Strategic assimilation and identity construction in middle-class suburbia
Karyn R. Lacy 《Ethnic and racial studies》2013,36(6):908-930
While white ethnics and immigrants of colour have been studied in terms of their attempts to assimilate into the American mainstream, sociologists assume that ongoing racial discrimination obviates the need for an extensive examination of the actual assimilation trajectories of middle-class blacks. Many middle-class blacks travel from the black to the white world rather than existing exclusively in one racially distinct environment. Yet, we do not fully understand how middle-class blacks conceptualize their own integration into American society. Drawing on data collected through in-depth interviews with middle-class blacks and ethnographic research in a white and a black suburb, I establish the link between an affinity for black spaces and the alternative assimilation trajectories of middle-class blacks. I find that middle-class blacks engage in a variant of segmented assimilation, privileging the black world as a site for socializing even if they live in a white suburb. This selective pattern of assimilation, what I term strategic assimilation, suggests that this population of middle-class blacks does not perceive itself as permanently constrained to the bottom rung of a racial hierarchy. 相似文献
3.
Thandeka K. Chapman 《Anthropology & education quarterly》2007,38(3):297-315
The following critical ethnography interrogates what it means for urban students to learn in multicultural ways, given the oppressive historical and present contexts of their newly desegregated urban district. By retelling events that occurred in the district and the classroom, I present a picture of urban students who are willing to learn and engage in classroom activities when the activities do not threaten their emotional safety. Although their actions are understandable, the students' conscious decisions to disengage from school stifles learning opportunities that would allow them to empathize and connect with other students as a move toward individual and group empowerment. Using critical race theory, I problematize the possibilities for successful multicultural classrooms in urban districts with complex legacies of injustice and racial hostility. 相似文献
4.
Xunming Sun Suzanne M. Bertisch Susan Redline Lydia Bazzano 《Chronobiology international》2020,37(1):123-134
ABSTRACTResearch indicates that sleep duration and quality are inter-related factors that contribute to obesity, but few studies have focused on sleep chronotype, representing an individual’s circadian proclivity, nor assessed these factors in racially diverse middle-aged samples. We examined the associations between chronotype and obesity among black and white men and women participating in the Bogalusa Heart Study (BHS).Body mass index (BMI) and sleep data were available for 1,197 middle-aged men and women (mean age 48.2 ± 5.3 years) who participated in the BHS 2013–2016. Based on the reduced Morningness-Eveningness Questionnaire’s cutoff values for chronotypes, we combined ‘definitely morning’ and ‘moderately morning’ types into ‘morning’ type, ‘definitely evening’ and ‘moderately evening’ types into ‘evening’ type and kept those who were “neither” type in a separate group. We used ‘morning’ type as the referent group. Obesity was defined as a BMI ≥ 30. Multivariable logistic regression models were used to examine associations adjusting for sex, age, education, smoking, alcohol use and drug use, depression, shift work, physical activity and sleep duration.Evening chronotype, reported by 11.1% of participants, was associated with obesity after multi-variable adjustment, including shift work, physical activity and sleep duration (OR 1.67, 95% CI: 1.08–2.56). However, once stratified by race (black/white), this association was found only among white participants (OR = 1.91, 95% CI = 1.12–3.25) after full adjustment.In our biracial, community-based population, evening chronotype was independently associated with obesity, specifically among white participants. Further research is needed to identify behavioral, endocrine, nutritional and genetic pathways which underlie these associations. 相似文献
5.
Walter Randall 《Biological Rhythm Research》2013,44(4):227-242
Abstract The annual pattern of black and white births in the Southeastern and Midwestern United States was analyzed for the years 1969 thru 1976. Monthly means for the eight‐year period were obtained individually for 17 states and for black births in the District of Columbia. The states and the district were selected for their large black populations and represent approximately 70% of black births in the USA. The data were analyzed in two ways, with an analysis of variance (the two‐factor mixed design with repeated measures on one factor) and by comparing the confidence intervals for the least‐squares derived Fourier coefficients of a sine curve. In addition, the range was compared between regions and between races and related to latitude. The analyses of variance indicated that statistically significant differences existed between regions and between races. The cosinor‐like method failed to adequately represent the data in most cases. The completely urban black population in the District of Columbia exhibited an annual pattern that was similar to the pattern in neighboring states, states that contained large rural populations. The range in the monthly averages of births was different between regions and between races, and inversely correlated with latitude (with “North”; and “white”; having smaller ranges). Some possible causative factors are briefly reviewed, and the correlation of sperm counts and conceptions offered as a new possibility. 相似文献
6.
Pratap C. Dutta 《American journal of physical anthropology》1972,36(3):391-396
The biometric data on 72 usable adult skulls excavated at Harappa and dated ca. 2500-1700 bc have been re-examined in the light of the genetic concept of “population.” The original study of the material considered separately and independently the various samples from locally differentiated cultural deposits, Cemetery R37, Area G, Cemetery H, etc., and used the typologic concept of racial analysis, a traditional method now sterile. One of the major findings of the study, postulating hypothetical original races, was that a varying proportions of different racial “types” constituted each sample. The present analysis is designed, first, to identify the particular population responsible for the growth of the true Harappan culture and, secondly, to define some selected physical characters of the population. Fifteen variables provided statistical evidence that the pooled remains of Cemetery R37 and Area G can be considered as a sufficiently homogeneous Harappan population. Further, in the absence of statistically significant differences in separate measurements, the entire material may be regarded as representing the Bronze-Age Harappans. Accordingly, some selected cranio-facial features of the population have been described. 相似文献
7.
The effect of nitrogen fertilizer and irrigation on black point incidence in soft white spring wheat 总被引:1,自引:0,他引:1
Agronomic studies were conducted to examine the effect of fertilizer N on black point incidence in Fielder soft white spring wheat (Triticum aestivum L. em Thell.). Black point incidence rose with increases in the amount of N supplied either as fertilizer applied during the growing season in irrigation water or as soil N, specifically nitrate, from fertilizer N application in previous years. A comparison of four different irrigation regimes demonstrated that black point incidence was highest under frequent irrigation (irrigate to field capacity at 75% available moisture) and lowest under conventional irrigation (irrigate to field capacity at 50% available soil moisture). In each irrigation regime, disease incidence increased as N rates were raised from 0 to 120 kg ha-1. A residual fertilizer-N study demonstrated in 1985 and 1986 that black point incidence generally rose with increasing levels of nitrogen from either preplant applications in the spring or soil nitrate from the previous year. However, additions of fertilizer N were shown to slightly reduce black point incidence at soil nitrate levels above 150 kg ha-1. A two-year fertilizer N study demonstrated that in treatments receiving the same amount (90 kg ha-1) of fertilizer N, the amount broadcast as a preplant treatment versus the amount applied in irrigation water in a fertigation treatment had no effect on black point incidence, but all fertilized treatments had significantly higher levels of disease than the unfertilized check.Contribution no. 3879016 相似文献
8.
Donna Deyhle 《Anthropology & education quarterly》2007,38(3):209-220
Over a 50-year professional career, Dr. Beatrice Medicine never failed to assert the importance of Indigenous language rights or to challenge racism in the academy, public schools, and society. She urged educational anthropologists to confront racism in our research with Indigenous peoples. She challenged linguicism and urged the teaching of Native American languages in schools. Bea Medicine's legacy provides a compelling vision for the future of the field of educational anthropology, particularly in the domains of critical race theory and critical language studies. In this article, we consider both the legacy and the vision of Beatrice Medicine as they guide us to new arenas of research and praxis. 相似文献
9.
Ellis Cashmore 《Ethnic and racial studies》2013,36(4):642-659
The findings draw on independent research conducted in the aftermath of the Macpherson Report of 1999 and are based on in-depth interviews with African Caribbean and South Asian officers in five British police services. Serving officers offer their frequently contrasting views on the underrecruitment of ethnic minority officers and their experiences in the police force and beyond. While many question whether increasing the recruitment of ethnic minority officers would make the widely-assumed positive impact in reducing racism, others maintain that it would; but they believe persistent habitual racist practices by white officers serves as the most formidable impediment to recruitment. Reasons are offered for this persistent racism. It is proposed that the trend towards assessing occupational performance in the police has had the unintended consequence of promoting racial profiling, or selecting ethnic minority groups for unfair treatment. Ethnic minority police officers are subject to racist abuse as a way of 'testing' them. They believe that, if they protest against either their own treatment or that of ethnic minority civilians, they may damage their careers. This perception acts as a deterrent to challenging racism in police work and contributes towards its continuation. 相似文献
10.
D B Hull 《American journal of physical anthropology》1979,51(2):163-181
This study examines the craniometry of Black and White Colobus monkeys using 1072 specimens representing all the recognized subspecies (after Rahm, '70) of the genus. Seventy-six measurements were taken on each individual, and examined using canonical variates analysis and clustering by Ward's Error Sum method. The assumptions of the analytical techniques are shown to be met, and the results demonstrated to be stable. Examination of the populations for statistical difference and taxonomic distinctiveness using a multivariate extension of Mayr's Rule indicates that the taxonomy presented by Rahm ('70) is essentially correct, except that the subspecies of guereza across the northern part of Central Africa should be lumped into a single group--C. g. occidentalis--and the subspecies of montane angolan colobus in Eastern Zaire should all be lumped into C. a. ruwenzorii. The systematic patterns of the genus illustrate the whole range of the process of speciation, from barely distinct subspecies, to subspecies almost as distinct as allopatric species of the genus, and on the fully sympatric species Three major zoogeographic areas may be delineated: an East African area dominated by the effects of the Rift Valley, with a large number of subspecies isolated in forest islands; a Central African area with little subspeciation and sympatric overlap of the major species of Colobus; and a West African area with a clinal pattern of distribution of subspecies, and secondary intergradation. The arbitrary nature of Mary's Rule is also apparent. Lastly, the CVA indicated major differences across the genus to be located in the teeth and jaws, suggesting diet might be an important distinguishing feature in Colobus. 相似文献
11.
Andrea Patterson 《Journal of the history of biology》2009,42(3):529-559
Race proved not merely a disadvantage in securing access to prompt and appropriate medical care, but often became a life and
death issue for blacks in the American South during the early decades of the twentieth century. This article investigates
the impact some of the new academic disciplines such as anthropology, evolutionary biology, racially based pathology and genetics
had in promoting scientific racism. The disproportionately high morbidity and mortality rates among blacks were seen as a
consequence of inherent racial deficiencies that rendered any attempt to ameliorate their situation as futile. While the belief
in a different pathology in blacks initially deterred most health officials from taking any action, advances in medicine and microbiology, in particular the germ theory, stirred a variety of responses out of sheer
self preservation, as fears among whites at the first sign of an epidemic initiated sporadic and limited actions. Ironically,
in an era of deepening scientific racism, public health initiatives based on a better understanding of disease causing microorganisms,
gradually improved black health. However, some public health measures were hijacked by eugenicists and racists and, rather
than addressing the ill health of blacks, public health policy complied with the new laws of heredity by promoting drastic
measures such as involuntary sterilization or even abortion. This further complicated the strained relationship between southern
blacks and health care professionals and effected ongoing distrust towards public healthcare services. 相似文献
12.
Protein phosphorylation is one of the major signal transduction mechanisms for controlling and regulating intracellular processes. Phosphorylation of specific hydroxylated amino acid side chains (Ser, Thr, Tyr) by protein kinases can activate numerous enzymes; this effect can be reversed by the action of protein phosphatases. Here we report ab initio (HF/6-31G* and Becke3LYP/6-31G*) and semiempirical (PM3) molecular orbital calculations pertinent to the ion pair formation of the phosphorylated amino acids with the basic side chains of Lys and Arg. Methyl-, ethyl-, and phenylphosphate, as well as methylamine and methylguanidinium were used as model compounds for the phosphorylated and basic amino acids, respectively. Phosphorylated amino acids were calculated as mono- and divalent anions. Our results indicate that the PSer/PThr ion pair interaction energies are stronger than those with PTyr. Moreover, the interaction energies with the amino group of Lys are generally more favorable than with the guanidinium group of Arg. The Lys amino groups form stable bifurcated hydrogen bonded structures; while the Arg guanidinium group can form a bidentate hydrogen bonded structure. Reasonable values for the interaction free energies in aqueous solution were obtained for some complexes by the inclusion of a solvent reaction field in the computation (PM3-SM3). 相似文献
13.
Michael Gudo 《Theorie in den Biowissenschaften》2002,121(1):101-137
Summary The critical theory of evolution was developed by a group of scientists working together with Wolfgang F. Gutmann at the Senckenberg-Research-Institute in Frankfurt am Main. Gutmann worked at Senckenberg for 37 years. In this time he presented 247 contributions which are distributed over 47 periodicals and books. The ideas that were developed by Gutmann and his colleagues were innovative and pathbreaking for morphology and evolutionary biology. The large number of his morphological publications is indicative of the wide field that was opened up by the concepts of constructional morphology. As some of his colleagues have suggested, constructional morphology as an engineering approach to the study of organisms (i. e., engineering morphology) may replace the traditional concepts of morphology and anatomy and provides the observational base for the historical reconstruction of evolutionary pathways. Constructional morphology as a quasi-engineering approach can be the morphological pendant to the contemporary molecular approaches to biology, as it can provide the necessary morphological basis for the interpretation of the results of molecular studies in the light of evolution. 相似文献
14.
ALLISON L. DUNN CAROL C. BARFORD† STEVEN C. WOFSY MICHAEL L. GOULDEN‡ BRUCE C. DAUBE 《Global Change Biology》2007,13(3):577-590
We present a decadal (1994–2004) record of carbon dioxide flux in a 160‐year‐old black spruce forest/veneer bog complex in central Manitoba, Canada. The ecosystem shifted from a source (+41 g C m−2, 1995) to a sink (−21 g C m−2, 2004) of CO2 over the decade, with an average net carbon balance near zero. Annual mean temperatures increased 1–2° during the period, consistent with the decadal trend across the North American boreal biome. We found that ecosystem carbon exchange responded strongly to air temperature, moisture status, potential evapotranspiration, and summertime solar radiation. The seasonal cycle of ecosystem respiration significantly lagged that of photosynthesis, limited by the rate of soil thaw and the slow drainage of the soil column. Factors acting over long time scales, especially water table depth, strongly influenced the carbon budget on annual time scales. Net uptake was enhanced and respiration inhibited by multiple years of rainfall in excess of evaporative demand. Contrary to expectations, we observed no correlation between longer growing seasons and net uptake, possibly because of offsetting increases in ecosystem respiration. The results indicate that the interactions between soil thaw and water table depth provide critical controls on carbon exchange in boreal forests underlain by peat, on seasonal to decadal time scales, and these factors must be simulated in terrestrial biosphere models to predict response of these regions to future climate. 相似文献
15.
Summary S. 184 white clover was surface seeded into natural molinia pasture on wet stagnogley soil containing no indigenousRhizobium trifolii. Seedlings were ‘spray inoculated’ after emergence with each of three strains ofR. trifolii. The best of these treatments produced an eight fold improvement in dry matter in the seeding year, followed by a 28% improvement
in the following year. The results confirm the potential benefits which may be achieved by inoculating clover with suitable
strains of rhizobia. The data are compared with a previously reported trial on an adjacent site where benefits were much greater
in the first year. The difference is attributed to the overall advantages conferred in the present trial by much higher seedling
populations and less severe competition from native species in the establishment phase. 相似文献
16.
W. Tecumseh Fitch 《Biology & philosophy》2005,20(2-3):193-203
For many years the evolution of language has been seen as a disreputable topic, mired in fanciful “just so stories” about
language origins. However, in the last decade a new synthesis of modern linguistics, cognitive neuroscience and neo-Darwinian
evolutionary theory has begun to make important contributions to our understanding of the biology and evolution of language.
I review some of this recent progress, focusing on the value of the comparative method, which uses data from animal species
to draw inferences about language evolution. Discussing speech first, I show how data concerning a wide variety of species,
from monkeys to birds, can increase our understanding of the anatomical and neural mechanisms underlying human spoken language,
and how bird and whale song provide insights into the ultimate evolutionary function of language. I discuss the “descended
larynx” of humans, a peculiar adaptation for speech that has received much attention in the past, which despite earlier claims
is not uniquely human. Then I will turn to the neural mechanisms underlying spoken language, pointing out the difficulties
animals apparently experience in perceiving hierarchical structure in sounds, and stressing the importance of vocal imitation
in the evolution of a spoken language. Turning to ultimate function, I suggest that communication among kin (especially between
parents and offspring) played a crucial but neglected role in driving language evolution. Finally, I briefly discuss phylogeny,
discussing hypotheses that offer plausible routes to human language from a non-linguistic chimp-like ancestor. I conclude
that comparative data from living animals will be key to developing a richer, more interdisciplinary understanding of our
most distinctively human trait: language. 相似文献
17.
18.
Wolfgang Hagemann 《Plant Systematics and Evolution》1999,216(1-2):81-133
An organismic concept of land plants is outlined, which is based on a synthesis of plant morphology and plant anatomy. The entire plant, the living unity, is conceived as the organism being subdivided into cells, which cannot be interpreted as organisms themselves in the sense of elementary organisms. The evolution of land plant tissue systems is discussed in the introductive chapter.To test the proposed concept, some frondose plants were selected from liverworts (Pellia epiphylla, Metzgeria furcata, Pallavicinia lyallii) and comparable fern gametophytes (Dryopteris filix mas, Vittaria lineata, Stenochlaena tenuifolia) and studied with respect to their organization and the principles of development. They all have an archetypic, two-dimensional, open construction, which is described as the repens-type of plant construction. Primary form growth occurs in the marginal blastozone, which controls cell wall integration. One of the most significant processes of form generation is blastozone fractionation. The tissues leaving the blastozone differentiate during extension growth and maturation of the vegetation body. While the plant grows continuously in the blastozone, it decays steadily in the necrozone.The implications of the two-dimensional repens-type are discussed. It appears as a perfect plant construction, fit to start plant evolution on the land surface. Growing upwards into the atmosphere, the repens-type is obscured. But is reappears in all groups of higher land plants. This demonstrates the existence of evolutionary cycles in plants. It is argued that mutation and selection do not suffice to understand cyclical evolutionary patterns. The influence of organismic construction seems to predetermine evolution because of the limited options to change an appropriately functioning construction. Via construction analysis evolutionary options can be detected and thus, evolution becomes predictable to some extent. Instead of being object of mutation and selection, living organisms should be conceived as subjects in evolution (Weingarten 1993).Dedicated to my admired teacher Professor DrWilhelm Troll on the occasion of his 100th birthday, 3rd November, 1997. 相似文献
19.
In this paper we establish a relation between the spread of infectious diseases and the dynamics of so called M/G/1 queues with processor sharing. The relation between the spread of epidemics and branching processes, which is well known in epidemiology, and the relation between M/G/1 queues and birth death processes, which is well known in queueing theory, will be combined to provide a framework in which results from queueing theory can be used in epidemiology and vice versa.In particular, we consider the number of infectious individuals in a standard SIR epidemic model at the moment of the first detection of the epidemic, where infectious individuals are detected at a constant per capita rate. We use a result from the literature on queueing processes to show that this number of infectious individuals is geometrically distributed. 相似文献
20.
Rachel A. Ankeny 《Journal of the history of biology》2000,33(2):315-347
The so-called “biometric-Mendelian controversy” has received much attention from science studies scholars. This paper focuses
on one scientist involved in this debate, Arthur Dukinfield Darbishire, who performed a series of hybridization experiments
with mice beginning in 1901. Previous historical work on Darbishire’s experiments and his later attempt to reconcile Mendelian
and biometric views describe Darbishire as eventually being “converted”' to Mendelism. I provide a new analysis of this episode
in the context of Darbishire’s experimental results, his underlying epistemology, and his influence on the broader debate
surrounding the rediscovery and acceptance of Mendelism. Iinvestigate various historiographical issues raised by this episode
in order to reflect on the idea of “conversion” to a scientific theory. Darbishire was an influential figure who resisted
strong forces compelling him to convert prematurely due to his requirements that the new theory account for particularly important
anomalous facts and answer the most pressing questions in the field.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献