Functions of eukaryotic DNA polymerases

A major function of DNA polymerases is to accurately replicate the six billion nucleotides that constitute the human genome. This task is complicated by the fact that the genome is constantly challenged by a variety of endogenous and exogenous DNA-damaging agents. DNA damage can block DNA replication or alter base coding potential, resulting in mutations. In addition, the accumulation of damage in nonreplicating DNA can affect gene expression, which leads to the malfunction of many cellular processes. A number of DNA repair systems operate in cells to remove DNA lesions, and several DNA polymerases are known to be the key components of these repair systems. In the past few years, a number of novel DNA polymerases have been discovered that likely function in replicative bypass of DNA damage missed by DNA repair enzymes or in specialized forms of repair. Furthermore, DNA polymerases can act as sensors in cell cycle checkpoint pathways that prevent entry into mitosis until damaged DNA is repaired and replication is completed. The list of DNA template-dependent eukaryotic DNA polymerases now consists of 14 enzymes with amazingly different properties. In this review, we discuss the possible functions of these polymerases in DNA damage repair, the replication of intact and damaged chromosomes, and cell cycle checkpoints.     

Aging of the human adrenal cortex

The most striking age-related change in the human adrenal cortex is the decline in secretion of dehydroepiandrosterone and its sulfate, steroids synthesized by the inner zone of the cortex, the zona reticularis. Because these steroids are of essentially unknown function, the importance of this age-related change is the subject of considerable debate. It is likely that the age-related change in these steroids results from loss of zona reticularis cells or impairment of their function. During aging, cumulative damage to the zona reticularis could occur through ischemia-related infarcts and other causes of cell death. Cellular senescence could contribute to a loss of the ability of the tissue to replace lost cells. In contrast, feedback mechanisms that regulate adrenocortical growth cause compensatory local tissue hyperplasias called nodules. The effect of imperfect repair of damage combined with compensatory overgrowth in the form of nodules leads to an increasingly abnormal tissue architecture.     

Single-cell antisense RNA amplification and microarray analysis as a tool for studying neurological degeneration and restoration

Neurodegenerative diseases typically affect subpopulations of neurons. Characterizing these vulnerable cells and identifying the factors that make them susceptible to damage while neighboring cells remain resistant are essential to the understanding of molecular pathogenesis that underlies neurodegenerative diseases. Classically, molecular analysis of the central nervous system involves the identification and isolation of an anatomic region of interest; next, the relevant tissue is pulverized, and the resulting homogenate is analyzed. Although this method provides useful data, its effectiveness diminishes when used in areas of high cellular diversity or in instances in which one cell type is lost as a consequence of selective cell death or quiescence. A technique that affords the ability to assess molecular events in a very precise anatomical site would provide a powerful tool for this research discipline. In this review, we discuss the amplification of messenger RNA from single neural cells and the subsequent use of the RNA to probe DNA microarrays in an effort to create cell-specific molecular profiles. Specifically, recent work in single-cell expression profiling in Alzheimer's and Huntington's diseases is discussed. We also review some new work with neural stem cells and their application to restorative neurobiology. Finally, we discuss the use of cell-specific molecular profiles to better understand the basics of neuronal cell biology.     

Making young tumors old: a new weapon against cancer?

As the population of industrial nations ages, the incidence of cancer and cancer mortality is increasing. Intuitively, older organisms may be less able to cope with accumulated damage and thus be more prone to develop cancer. However, so far, the links between aging and cancer have been only partially explored. Strikingly, four recent studies now indicate that premature senescence accompanied by cell cycle arrest occurs in tumors initiated by an oncogenic mutation. Thus, senescence may act as a key tumor suppressor mechanism in young tumors in vivo.     

International Disaster Compensation Fund: A New International Financial Aid Mechanism

In May 2008, two consecutive disasters shocked the whole world. Both the China earthquake and the Myanmar cyclone forced people all around the world to realize how harsh and merciless the power of nature is. The massive devastation influenced not only the two countries but also the whole world. The world today is highly interdependent. One country’s disaster can spill over to other countries through political and economic channels. There is no disaster limited to one country, and human beings cannot solve the issue of living without mishap when facing a disaster. Therefore, no country can escape by sheer luck from disaster and solve the problem alone. Indeed no country lives in absolute safety. In this case, the whole world should unite together to share the risks. Human beings should work together to face, resist and eliminate risks. But unfortunately, such a kind of system which can effectively deal with natural disaster has never existed. In this situation, we have designed the International Disaster Compensation Fund (IDCF) to give a new idea of how to manage the risk together.     

The longevity gender gap: are telomeres the explanation?

In this Perspective, we focus on the greater longevity of women as compared with men. We propose that, like aging itself, the longevity gender gap is exceedingly complex and argue that it may arise from sex-related hormonal differences and from somatic cell selection that favors cells more resistant to the ravages of time. We discuss the interplay of these factors with telomere biology and oxidative stress and suggest that an explanation for the longevity gender gap may arise from a better understanding of the differences in telomere dynamics between men and women.     

Germline genomes--a biological fountain of youth?

The fusion of male- and female-derived gametes initiates the phenomenal process of producing a highly complex mammalian organism. Successful reproduction is so important that mammals invoke a battery of protective mechanisms for the germ cell lineages that function to maximize genetic integrity while still allowing genetic diversity and adaptation. Protective mechanisms likely include, but are not limited to, robust DNA repair to safeguard genetic integrity and apoptosis to remove cells with intolerable levels of DNA damage. Analyses of spontaneous mutant frequencies are generally consistent with germline DNA being stringently maintained relative to somatic tissues. Despite the rigorous protection afforded germ cells, genetic integrity is observed to decline with increased maternal and paternal age. It is not yet clear whether cells in the germ line truly age or whether other processes decline or become dysfunctional with age. For example, in a younger animal, the differentiation and/or utilization of germ cells with lower genetic integrity might be disallowed, whereas in an older animal, such cells might slip past these quality-control mechanisms.     

从跨文化交际角度看语言与性别的关系及其原因研究

人是社会动物,社会性是人类的基本属性之一。社会使“交际”成为必需,因此作为人类,“不交际是不可能”的。本文从跨文化交际角度出发,以整齐划一的文化定势为标准开展对两性语言特征的对比研究,力图找出并解决性别文化差异给跨文化交际带来的误解和矛盾等难题。     

More than a sum of our cells

Cells in the body grow and die, cells in lab dishes grow and die, and individual organisms grow and die. The parallels seem maddeningly obvious, but scores of scientists still labor to draw the correct connections, to uncover the mechanisms that underlie aging in cell culture flasks and in whole animals. Do our cells stop growing, quit working, cease dividing, or start dying as we age? Do we die when our cells do, or are we somehow more than the sum of our cells? For decades, scientists have searched for evidence that links changes in cell growth, cell function, cell division, and cell death to the phenomenon we call aging. Although definitive proof eludes them, researchers continue to conduct experiments in tissue culture and in animal models, amassing information that points us toward a greater understanding of what aging is--and is not.     

A post‐genomic surprise. The molecular reinscription of race in science,law and medicine

The completion of the first draft of the Human Genome Map in 2000 was widely heralded as the promise and future of genetics‐based medicines and therapies – so much so that pundits began referring to the new century as ‘The Century of Genetics’. Moreover, definitive assertions about the overwhelming similarities of all humans' DNA (99.9 per cent) by the leaders of the Human Genome Project were trumpeted as the end of racial thinking about racial taxonomies of human genetic differences. But the first decade of the new century brought unwelcomed surprises. First, gene therapies turned out to be far more complicated than any had anticipated – and instead the pharmaceutical industry turned to a focus on drugs that might be ‘related’ to population differences based upon genetic markers. While the language of ‘personalized medicine’ dominated this frame, research on racially and ethnically designated populations differential responsiveness to drugs dominated the empirical work in the field. Ancestry testing and ‘admixture research’ would play an important role in a new kind of molecular reification of racial categories. Moreover, the capacity of the super‐computer to map differences reverberated into personal identification that would affect both the criminal justice system and forensic science, and generate new levels of concern about personal privacy. Social scientists in general, and sociologists in particular, have been caught short by these developments – relying mainly on assertions that racial categories are socially constructed, regionally and historically contingent, and politically arbitrary. While these assertions are true, the imprimatur of scientific legitimacy has shifted the burden, since now ‘admixture research’ can claim that its results get at the ‘reality’ of human differentiation, not the admittedly flawed social constructions of racial categories. Yet what was missing from this framing of the problem: ‘admixture research’ is itself based upon socially constructed categories of race.     

Promoting rights or avoiding litigation? The introduction of the human rights act 1998 into adult social care in England

Rights to social care in England have traditionally been highly restricted. By placing positive obligations on social care agencies and practitioners to make provision for vulnerable adults, the incorporation of the European Convention on Human Rights into UK law through the Human Rights Act 1998 promised to extend their reach. Yet transforming a set of largely procedural rights into something more substantive requires the active intervention of social care practitioners. This article firstly examines the fit between human rights and the policy and operational contexts of social care before exploring the views of social workers included in a recent interview study. Whilst the findings point to a willingness on the part of some to advocate on behalf of vulnerable adults, they also highlight the extent to which individualistic beliefs about dependency and responsibility reinforce the dominant construction of citizenship rights under the current government as contingent upon the fulfilment of responsibilities. Treating the Human Rights Act as a weapon of litigation, the article concludes, simply reinforces defensive practice. Progressive change is best supported by fostering a human rights culture in social care which, in turn, depends upon challenging social workers’ assumptions about the nature of dependency, responsibility and rights.     

The Masculine Sociology of Prison Escapes and Inmate Recapture: Exploring the Discursive Representation of Prison Escapes in Scotland c. 1941 ‐ 1978

This paper theorises historical prison escapes by male prisoners from Scottish prisons, arguing that they represent a form of hegemonic masculinity. That dominant masculinity parallels recapture narratives constructed by the official masculinity associated with military service and its transfer to the prison ethos. Manly soldiering cultivated in prison officers with previous military service suited them to security duties. Violence, cunning, determination and athleticism is reflected in the escape bids, and human needs. These escapes occurred before electronic technology secured prison estates, so the strength and vigilance of the prison officers was essential. The sociology of escapes and the prison community literature underpins the paper's narrative analysis. It is concluded that escape data offers opportunities to understand the material nature of escape processes, and the representation of masculinity as reflected through accounts of technologies implemented in escapes, as well as to how the state represents prison escapes. By connecting masculinity to prison escape processes, a conceptual bridge is created between prison culture and concepts of masculinity. The latter, it is argued, are represented in narrative depictions of escapes. Escape narratives teach us about material forms of legal violence and embrace a tacit recognition of heterosexual manliness.     

Urban human ecology

Cities are human ecosystems. Eight primary concepts assist us in understanding human ecosystems in terms of variability, time, and complexity. These concepts include: systems thinking; language, culture, and technology; structure, function, and change; edges, boundaries, and ecotones; interaction, integration, and institution; diversity; adaptation; and holism. Hierarchy theory presents a framework for organizing these concepts. Human settlements can be viewed hierarchically, that is, from a more immediate scale to the global. In this paper, the eight concepts will be explored and applied to the urban context. The exploration of human ecology is useful to design and plan the built environment. The ability to respond to change and to adjust actions positively helps to determine the resilience of cities     

Market entry: An experimental investigation

Experimental oligopoly markets for homogeneous products were conducted to investigate cooperative behaviors when subjects were allowed to choose whether or not to enter the market. Two types of games were designed. One was a one-stage game in which subjects were given a payoff table and asked only to make an entry decision; the other was a two-stage game in which subjects had to decide whether or not to enter and then compete either in prices or in quantities. Data indicated a significant tendency to establish entry cycles, with players entering one at a time, in the one-stage “price-setting” markets. On the contrary, this tendency was never observed in the one-stage “quantity-setting” markets. The results in the two-stage game reinforced the difference in the observed behaviors between the price- and quantity-setting markets. In the former, subjects generally behaved in conformity with the Nash equilibrium predictions, whereas in the latter these predictions were not observed.     

Environmental/Green Cultural Shifts: Dynamics of Social Change

The greening of society is a strong cultural wave as we enter the second decade of the century. This article considers what it means to be ‘green’, core issues that the environmental sustainability wave brings to society and the role of sociology its evolution in public culture. A key argument offered is that sociologists’ historic commitment to critical analysis and to social justice could be important in determining whether the green wave is simply a cultural trend or if it will expand to become a cultural shift. The contributions of environmental sociology, ecofeminism, deep ecology, and green economics are considered significant influences on the relationship between environmentalism and social analysis. Whether scholars and activists can link key concepts such as sustainable development, ecological sensitivity, human dignity, and social justice may prove critical for achieving the goal of societal transformation toward a greener culture.     

A Comparative Study of Two Different Teaching and Curricular Arrangements in Human Behavior and Social Environment

In this paper we examine using social work faculty to teach Human Behavior and Social Environment content to undergraduate social work students versus using faculty from other departments. We formulated three hypotheses: social work students from a program with “IN” (taught by social work faculty) HBSE courses learn a wider range of theoretical orientations, are more capable of utilizing HBSE knowledge in practice, and are more sensitive to. human relations than are those from a program with “OUT” (taught by other faculty) HBSE courses. The data suggested that there were no significant differences between students.     

Camp experiences in the lives of adolescents with serious illnesses

This study explored the experiences of a summer camp for adolescents with serious illnesses and included interview responses from campers with different types of serious illnesses. Twenty-four youth aged 14–15 with cancer, sickle cell disease, HIV/AIDS, or metabolic diseases provided videotaped interviews that were analyzed using an interpretative phenomenological approach, and frequencies of responses per theme and diagnosis were computed. Camp experiences varied across diagnostic groups and featured: a sense of belonging, enjoyment, being myself, positive affect, camp programming, adult staff, personal growth, and escape. Some qualitative variations existed between diagnosis groups. Campers with cancer perceived camp as a place for sense of belonging, personal growth, and escape. Campers with HIV/AIDS perceived camp as an opportunity for a sense of belonging, being myself, camp programming, and escape. Campers with sickle cell disease perceived camp as a place for enjoyment, adult staff, being myself, personal growth, and escape. Campers with metabolic diseases perceived camp as a place for personal growth and positive affect. Professionals caring for youth with serious illnesses should consider adding camp to the list of interventions to promote children's well-being. Future research should include more youth and illness types.     

(Visual) Disability – from exclusive perspectives to inclusive differences

By introducing the concept ‘inclusive differences’ of disability this paper suggests that disability is the outcome of historically specific, embodied human and non‐human configurations fabricated within the conduct of everyday life. Inclusive differences question the attempt given by exclusive perspectives that try to divide analytically, conceptually or politically ‘disability’ a priori into an individual (natural) bodily impairment or a purely socio‐cultural attributed disability. Applying the concept of inclusive differences, neither the domain of ‘nature’ nor ‘society’ can function as a disability’s self‐explanatory force. Rather, inclusive differences highlight the connection between human and non‐human relations that make up the different enabling and/or disabling scenarios of societal realities. Drawing on the practices of blind people in a visual culture this paper discusses related specificities of inclusive differences.     

当代大学生身体审美趋向及特征

随着商业文化、大众传媒的迅猛发展，一直隐匿于私人领域深处的身体，开始了几乎无需遮掩的向公共话语空间展示的过程，成为当代审美文化场景中最为突出的主题意象之一。这一风潮成功地穿越了大学的围墙，影响了当代大学生的身体审美，形成了他们特定的趋向和特点。深入地分析当代大学生身体审美的生成背景、发展趋向和特点，从思想和实践层面对大学生加强引导，不断地提升大学生对时尚文化甄别能力和欣赏品位，这是当前高校大学生文化建设的当务之急。