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Sleep and Biological Rhythms - Age-specific relationship of sleep–wake pattern with night sleep satisfaction was examined to address a question of why sleep satisfaction does not accurately...  相似文献   

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Sociological studies of police relations with black and Asian people have mostly been concerned with the differential use of legal and other powers. Social processes that mould the phenomenal forms in which race and ethnicity are perceived have been neglected. In this article, data from interviews with black and Asian serving police officers and resigners are used to discuss the different ways in which they responded to racialized categories sustained within the police workforce. It is argued that the occupational cultural context within which responses to racialization occur is central to such an analysis. The reflective approach of officers to assigned ethnic categories is equally central. Diversity rather than a similarity of responses is found. This, however, does not mean that a wholly situational account of racialized relations is desirable. Further studies of the type described here, undertaken in different occupational and organizational contexts, might identify essential forms and processes of social exclusion.  相似文献   

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There is a growing list of cells that are capable of detecting and responding to changes in the concentration of extracellular calcium. The two classic examples of this behaviour are the calcitonin-secreting parafollicular cells of the thyroid and parathyroid hormone-secreting chief cells of the parathyroid gland. A more recent addition to this list is the renin-secreting juxtaglomerular cell of the kidney. Particularly intriguing has been independently the discovery by two laboratories, that the resorptive cell of bone, the osteoclast, is capable of detecting changes in ambient calcium. A common theme amongst all these so called calcium-responsive cells is that extracellular calcium increases elevate intracellular calcium levels, and this intracellular signal is either stimulatory or inhibitory to the functional response. But how these cells detect changes in the concentration of extracellular calcium, and how these recognition events are subsequently transformed into intracellular signals that regulate cell function are somewhat less clear. The commentary reveals some recent developments that seemingly provide insights into these mechanisms, with special reference to the osteoclast.  相似文献   

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The long-term relationship between pollutant discharge and river water quality of biological/biochemical oxygen demand (BOD) in the Yamato-gawa River, Japan, has been found to be similar to perturbation or dynamic equilibrium change of alternative stable states in the ecosystem fields with a linear relationship as a usual condition. Similar relationships have been observed in short-terms for single precipitation events both in the Richmond River, Australia, and in a mountainous watershed in Japan. On the contrary, nutrient concentrations have not changed in a long-term besides nutrient discharge increases in the Richmond River. In this paper, long-term chronological relationships of annual pollutant discharges and water quality in the Brisbane River, Australia, were investigated based on pollutant discharge estimations and water quality monitoring data as a case study in the “better” water quality river. Effects of precipitation variation were taken into account in the pollutant discharge estimations by introducing precipitation variance coefficient (PVC). Total nitrogen (TN) and total phosphorus (TP) concentrations in the river were found to be improved with fluctuations in the lower Brisbane River Catchment during 1975–2012. Long-term dynamic equilibrium alterations of pollutant discharge and water quality were found for TN and TP at the first time in the Brisbane River. The investigated term was found to be divided into two phases, 1975–2001 and 2001–2012 for TN, and 1975–2007 and 2005–2012 for TP. Both pollutant discharges and pollutant concentrations in the river were smaller in Phase 2 than Phase 1. Based on the relationships in the three rivers, a hypothesis on pollutant discharge and water quality from “better” to “worse” river water environment was presented that rapid and/or excess pollutant discharge increases cause perturbation or dynamic equilibrium alterations with the basal relationships as the linear relationships.  相似文献   

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ABSTRACT

We have recently shown that rest-activity circadian rhythm significantly differed in women with Binge Eating Disorder (BED) compared to the Ctrl group. In details, patients with BED exhibited significantly reduced levels of MESOR and Amplitude with respect to the Ctrl group. In addition, in this previous study, the results of the actigraphic sleep monitoring provided no evidence of differences in sleep parameters between the two groups. We expanded the original sample obtaining a total of 28 volunteered women, 14 BED women, and 14 Ctrl. We recorded in all 28 participants a 5-day actigraphic monitoring to detect the rhythmometric parameters, interdaily stability, intradaily variability, L5, M10, and sleep parameters. During the study, BED’s women group kept an individual multidisciplinary therapy lasting five weekly days, from Monday to Friday, consisting in cognitive-behavioral therapy and nutritional program, administered in outpatient care from 8:00 a.m. at 5:00 p.m. The combination of both our previous and current study supports the conclusion that the sleep quality of the BED group is significantly better compared to Ctrl. The non-parametric indexes showed how interdaily stability, significantly correlated to sleep efficiency, was higher in BED group compared to the Ctrl group, indicating a better synchronization of rest-activity circadian rhythm. In conclusion, the maintenance of a regular lifestyle, such as imposed by the multidisciplinary therapy, is important to avoid alterations in the sleep-wake cycle, particularly in patients with eating disorders.  相似文献   

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The spermatheca of Dipsocoridae is described and compared in the three known genera of the family (Cryptostemma, Harpago n. stat. and Pachycoleus); it consists of three distinct parts: a long coiled duct including a short apically differentiated segment (pars intermedialis) of unknown function, a spherical seminal capsule, and a small bulb-shaped apical gland with a muscular pump at its base. The structure of the spermatheca remains very uniform in the family, especially the apical gland that is anatomically distinct from the seminal capsule and which seems to be an apomorphy for the whole Dipsocoromorpha. A recently discovered structure, named here the loculus capsulae, appears to exist only in the two known species of the genus Harpago. This internal cuticular structure is situated on the left side of the seventh tergite. It consists of two broad expansions, extending from the tergite and laterotergite respectively, which maintain the seminal capsule near the abdominal wall. This structure appears as a kind of supporting armature impeding the spherical seminal capsule from free movement in the abdominal cavity. The form and function of this strange structure are discussed in this paper.  相似文献   

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《Chronobiology international》2013,30(10):1201-1208
Early shift start time and night shifts are associated with reduced sleep duration and poor sleep quality that often lead to increased fatigue levels, performance decrements and adverse safety and health outcomes. This study investigates the impact of shift starting time on sleep patterns, including the duration and quality of sleep and alertness/sleepiness at the time of injury, in a large epidemiological field study of hospitalized adults with severe work-related hand injury in the People’s Republic of China (PRC) from multiple industries with severe work-related traumatic hand injury were recruited from 11 hospitals in three industrially-developed cities in the PRC: Ningbo, Liuzhou and Wuxi. Analysis of covariance (ANCOVA) was used to compare sleep duration, sleep quality and alertness/sleepiness across 3?h increments of shift start time, while adjusting for age, gender, work hours, shift duration, day of injury and several transient work-related factors. Effect modification by gender was also evaluated. Seven-hundred and three hospitalized adults (96.4%) completed a face-to-face interview within 4 days of injury; 527 (75.0%) were male, with a mean (±SEM) age of 31.8?±?0.4 years. Overall, these adults worked relatively long weekly (55.7?±?0.6?h) and daily hours (8.6?±?0.07?h). Average sleep duration prior to injury was 8.5?h (±0.07), and showed significant variations (p value <0.05) across shift starting time increments. Overall mean prior sleep duration was shortest for individuals starting shifts from “21:00–23:59” (5.6±0.8?h) followed by midnight “00:00–02:59” (6.1?±?0.6?h). However, a statistically significant interaction (p?<?0.05) was observed between gender and shift starting time on mean sleep duration. For males the shortest sleep duration was 5.6?h (“21:00–23:59”) and for females the shortest was 4.3?h (“24:00–02:59” and “15:00–17:59”). Sleep quality (generally quite well) and alertness/sleepiness based on the KSS (generally alert) did not vary significantly across shift starting time. Results suggest that sleep duration is shortest among injured PRC adults starting shifts late night and early morning. However, with more than 8.5?h of sleep on average work days, Chinese slept much longer than typical US day workers (Sleep in America Poll, 2012, 6:44 on workdays, 7:35 on free days), and this may help to explain higher than expected alertness/sleepiness scores at the time of injury.  相似文献   

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Gynoecium development in taxa of the tribeVanguerieae (Rubiaceae, subfam.Antirheoideae) was studied, using primarily a 2- and a 5-carpellate genus (Keetia andVangueria) as examples. All investigated taxa, characterized by ovaries with a solitary, ± apically inserted, pendulous anatropous ovule per locule/carpel, showed a very similar gynoecium development. Comparisons with other uniovulateRubiaceae (taxa of subfam.Rubioideae) revealed that notwithstanding the place of insertion and orientation of the solitary ovules (apically vs. basally inserted, pendulous vs. erect, anatropous ovules) the gynoecium development follows the same pattern; differing ovule insertion and orientation can easily be explained by the principle of variable proportions. — Since secondary pollen presentation is characteristic for the tribe, particular attention was paid to the development of the conspicuous “stylar head”-complex, defined here as structural unit comprised of pollen presenting organ, “receptaculum pollinis”, plus stigmatic (i.e., receptive) surfaces. It was found that their morphological differentiation, following the same pattern in all investigated taxa, starts at very early stages of floral development. They already had their final shape at a stage when the ovule development in the ovary had just barely started. The fully developed, actual “receptaculum pollinis” is made up of enormously enlarged, ± cylindrical epidermis cells which have peculiar ring-like thickenings in vicinity of and parallel to the outer tangential walls (a “mechanical barrier” preventing pollen tubes from entering?) and a much smaller-celled subepidermal tissue. With regard to shape, size, and exposure of the stigmatic surfaces, the investigated taxa exhibited certain morphological differences. These were found to be correlated with differences in androecium structure (and, ultimately, pollen presentation).  相似文献   

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Here we consider the concept of kaluchua (a word adopted from the English culture) in group-living animals developed by Imanishi in the 1950s. He distinguished it from bunka (the Japanese equivalent to the English culture) because he thought that bunka had strong connotations of noble and intellectual human-like activities. Although he did not rigidly define kaluchua, his original concept of kaluchua was much broader than bunka and represented non-hereditary, acquired behavior that was acknowledged socially. However, instead of social life, complex feeding skills have often formed the central topic in the current studies of animal culture. In order to provide evidence that more subtle behavioral variations exist among wild chimpanzee (Pan troglodytes) populations, we directly compared the behaviors of two well-habituated chimpanzee groups, at Bossou and Mahale. During a 2-month stay at Bossou, M.N. (the first author) saw several behavioral patterns that were absent or rare at Mahale. Two of them, mutual genital touch and heel tap were probably customary for mature females and for mature males, respectively. Index to palm and sputter are still open to question. These subtle patterns occurred more often than tool use during the study period, suggesting that rarity is not the main reason for their being ignored. Unlike tool use, some cultural behavioral patterns do not seem to require complex skills or intellectual processes, and sometimes it is hard to explain the existence of such behaviors only in terms of function.  相似文献   

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Summary The differential staining methods for chromosomes have led to the demonstration of more chromosomal polymorphisms. Not rarely, these polymorphisms allow in autosomal trisomies the detection of parental origin of the supernumerary chromosome. In addition, the malsegregation may be ascribed to 1st or 2nd meiotic division in informative families.This approach of analyzing possible causes of trisomies is subject to a considerable bias. Trisomic phenotypes are twice as frequent for 2nd meiotic errors than for 1st meiotic errors. Also, rare chromosome variants seldom occur in matings where malsegregation in 1st meiotic division can be detected. In the present paper this bias is analyzed mathematically on the family as well as on the population level.From this mathematical analysis and from the data in the literature we conclude that Down's syndrome as a whole is caused about 5–10 times more often by a malsegregation in 1st meiotic than by an error in 2nd meiotic division.Mainly from experimental studies in rodents, causes for errors in 1st and 2nd meiotic division are becoming apparent. They are summarized in the context of the results of the present paper.Human population cytogenetics, a subject originated by Court Brown, has not, as yet, required mathematics at all unless we include—as I think we may correctly—the exact study of such variables as parental age and chromosomal measurements. L. S. Penrose (1970)We dedicate this paper to Professor Emeritus P. E. Becker, M.D., with our best wishes for his retirement.  相似文献   

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BackgroundDiabetes mellitus is a serious metabolic disease. Dysfunction and subsequent loss of the β-cells in the islets of Langerhans through apoptosis ultimately cause a life-threatening insulin deficiency. The underlying reason for the particular vulnerability of the β-cells is an extraordinary sensitivity to the toxicity of reactive oxygen and nitrogen species (ROS and RNS) due to its low antioxidative defense status.Scope reviewThis review considers the different aspects of the chemistry and biology of the biologically most important reactive species and their chemico-biological interactions in the β-cell toxicity of proinflammatory cytokines in type 1 diabetes and of lipotoxicity in type 2 diabetes development.Major conclusionThe weak antioxidative defense equipment in the different subcellular organelles makes the β-cells particularly vulnerable and prone to mitochondrial, peroxisomal and ER stress.Looking upon the enzyme deficiencies which are responsible for the low antioxidative defense status of the pancreatic β-cells it is the lack of enzymatic capacity for H2O2 inactivation at all major subcellular sites.General significanceDiabetes is the most prevalent metabolic disorder with a steadily increasing incidence of both type 1 and type 2 diabetes worldwide. The weak protection of the pancreatic β-cells against oxidative stress is a major reason for their particular vulnerability. Thus, careful protection of the β-cells is required for prevention of the disease.  相似文献   

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K. Granberg  H. Harjula 《Hydrobiologia》1982,86(1-2):129-132
A method for predicting the mean seasonal chlorophyll a concentration, the mean seasonal in vitro phytoplankton primary productivity per unit volume, the maximum daily production per unit volume and the seasonal integral production in brown-water lakes is presented. The production values can be calculated when the mean annual concentration of total phosphorus and the mean annual colour of the water are known. This method has been developed especially for practical water pollution studies to permit rapid and inexpensive estimates of major biological consequences of changes in effluent loads. The method can be applied for brown-water lakes where phosphorus is the limiting nutrient for primary production.  相似文献   

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Ethnobotanists use a variety of interview techniques to collect ethnobotanical data. Drawing upon the results from a quantitative ethnobotanical study in five Yuracaré and Trinitario communities in the Bolivian Amazon, the pros and cons of the following methods are evaluated: (1) interviews in situ during transects, walk-in-the-woods, and homegarden sampling; and (2) interviews ex situ with fresh plant material, voucher specimens, or plant photographs as reference tools. Although the systematic use of plant photographs for ethnobotanical interviews is poorly documented in literature, the results show that indigenoùs participants in our study recognize significantly more plant species from photographs than from voucher specimens. It is argued that, especially in remote and isolated study sites, photographs might be advantageous over voucher specimens.  相似文献   

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Summary The fine structural localization of the 5-nucleotidase was investigated in the CA3 region of the rat hippocampus. The attention was focussed on the occurrence of the enzyme in the synaptic region. The 5-nucleotidase activity was demonstrated at the surface membranes of axons and dendrites. Prominent portions of enzyme activity were detectable in the nuclei and the nuclear envelope, whereas the cytoplasmic organelles were nearly devoid of reaction product. In synapses five types of 5-nucleotidase localization were revealed. A participation of the enzyme in the process of neurotransmission is discussed.The research reported in this paper was supported by the Ministerium für Wissenschaft und Technik der DDR  相似文献   

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