人脑会被计算机实现吗?

目前,许多神经科学假设的基础是人的神经系统是一个可计算的系统,并在基本层次上发挥作用。因此,人工智能可能在更基础层面的功能上重现人脑的计算结构。比如,单个的神经元和神经元的互动是通过突触吗?单个人的大脑可能被上传到一个计算机或不同计算机上?不同的硬件能够准确计算相同的内容,数字计算允许“多重实现”,但对于不同实现之间它们共有的是什么?假如整个大脑是一台计算机的话,那么我们就能够扫描它,启动它的不同硬件,它会产生智能吗?我所讨论的这种共享的计算仅仅是一种句法属性,它仅仅解释了一部分属性,特殊实现的因果力正是由于物理属性和语义属性。即使一棵苹果树是一台数字计算机,它的不同硬件的实现不会结出任何果实。     

区域经济现代化问题

20年前,俄罗斯向市场型社会经济生活组织的转型是复杂而充满矛盾的,原因之一是市场改革的战略和决策,原因之二是世界经济快速全球化背景下危机的表现方式.在俄罗斯联邦第一任总统叶利钦执政时期,俄罗斯创建了大型民营企业、商业环境和市场基础设施.新社会秩序的基本步骤是建立在休克疗法基础之上,国家工业产值减少一半,固定资产投资减少五倍,就业率急剧下降,人民生活水平降低,国家的完整性也受到威胁.     

阿根廷“中国街”——阿维里尼奥斯街

严格地说,阿根廷没有唐人街。阿根廷的华侨华人不多,全国也就四五万人左右,而且大多数分散居住,分散经营,没有形成纽约或旧金山那样规模的唐人街,更没有富丽堂皇的牌楼式街门。 但是近年来,随着旅阿华侨华人的增多,华人经济实力的增强,也出现了一些华人企业较集中的街区。其中较著名的一条就是阿维里尼奥斯街,当地的阿     

Harvesting the biosphere: the human impact

The human species has evolved to dominate the biosphere: global anthropomass is now an order of magnitude greater than the mass of all wild terrestrial mammals. As a result, our dependence on harvesting the products of photosynthesis for food, animal feed, raw materials, and energy has grown to make substantial global impacts. During the past two millennia these harvests, and changes of land use due to deforestation and conversions of grasslands and wetlands, have reduced the stock of global terrestrial plant mass by as much as 45 percent, with the twentieth-century reduction amounting to more than 15 percent. Current annual harvests of phytomass have been a significant share of the global net primary productivity (NPP, the total amount of new plant tissues created by photosynthesis). Some studies put the human appropriation of NPP (the ratio of these two variables) as high as 40 percent but the measure itself is problematic. Future population growth and improved quality of life will result in additional claims on the biosphere, but options to accommodate these demands exist without severely compromising the irreplaceable biospheric services.     

Home birth and the National Australian Maternity Services Review: too hot to handle?

Background

In February 2009 the Improving Maternity Services in Australia – The Report of the Maternity Services Review (MSR) was released, with the personal stories of women making up 407 of the more than 900 submissions received. A significant proportion (53%) of the women were said to have had personal experience with homebirth. Little information is provided on what was said about homebirth in these submissions and the decision by the MSR not to include homebirth in the funding and insurance reforms being proposed is at odds with the apparent demand for this option of care.

Method

Data for this study comprised 832 submissions to the MSR that are publicly available on the Commonwealth of Australia Department of Health and Aging website. All 832 submissions were downloaded, coded and then entered into NVivo. Content analysis was used to analyse the data that related to homebirth.

Findings

450 of the submissions were from consumers of maternity services (54%). Four hundred and seventy (60%) of the submissions mentioned homebirth. Overall there were 715 references to home birth in the submissions. The submissions mentioning homebirth most commonly discussed the ‘Benefits’ and ‘Barriers’ in accessing this option of care. Benefits to the baby, mother and family were described, along with the benefits obtained from having a midwife at the birth, receiving continuity of care and having a good birth experience. Barriers were described as not having access to a midwife, no funding, no insurance and lack of clinical privileging for midwives.

Conclusion

Many positive recommendations have come from the MSR, however the decision to exclude homebirth from these reforms is perplexing considering the large number of submissions describing the benefits of and barriers to homebirth in Australia. A concerning number of submissions discuss having had or having considered an unattended birth at home due to these barriers. Overall there is the belief that not enabling access to funded, insured homebirth in Australia is a violation of human rights. It appears that homebirth was considered by the MSR as ‘too hot to handle’ and by dismissing it as a minority issue the government sought to avoided dealing with homebirth as a ‘sensitive and controversial issue.’     

Peer group self-identification in samples of Russian and U.S. adolescents

Most peer group self-identification research has been conducted in the United States. This article examined the generalizability of self-identified group name research among teens in Ufa, a city in the Russian Federation. A cross-sectional, anonymous collection of data on group self-identification, drug use, addiction concern, sensation seeking, and self-rated school performance was collected from 365 10th grade youth in Ufa and 965 10th grade youth in the United States. The results supported the existence of peer group self-identification by youth in both countries and, in general, replicated the findings that youth who self-identify as a High Risk Youth, are relatively likely to use drugs, show greater concern about becoming an addict, report a greater sensation seeking preference, higher levels of depression, and poorer school performance. Implications of these results are discussed.     

Adolescent migration and the 1990s nuptiality transition in Mali

Attempts to explain the rise in women's age at marriage across Africa have focused mainly on determinants in the urban environment, notably women's education and the economic recession. In our study, we examined the migration of adolescent girls as a factor in the transition to a later age of marriage in rural Mali, using an analysis of data from a longitudinal survey conducted over 20 years. The findings show a close correlation between the rise in labour migration and the onset of this nuptiality transition. Continuing changes in marriage patterns include not only its postponement but also a breakdown in the marriage formalization process. Two main mechanisms are documented: a direct one, as migration enables young women to choose the timing of their marriage and is a source of empowerment; and an indirect one, as migration challenges family marriage conventions and contributes to elders disengaging from control over marriage and young people.     

Prevalence of DSM-IV major depression among Spanish university students

OBJECTIVE: The authors' purpose in this study was to estimate prevalence and correlates of Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), major depressive episodes (MDEs) among Spanish university students. PARTICIPANTS AND METHODS: In October and November 2004, interviewers administered a screening tool to a sample of 554 students aged 18-34 years (65.9% women). RESULTS: The prevalence of MDEs was 8.7% (95% confidence interval = 6.5%-11.3%). The most common symptoms were depressed mood (81.3%) and altered sleep (79.2%). MDEs were more prevalent among women than men (p < .05). The mean number of previous episodes of depression among currently depressed students with previous episodes was 2.2 (SD = 1.4). Of depressed students, 0.6% had considered suicide and 0.2% had attempted suicide. CONCLUSIONS: Depression was highly prevalent among university students. The results suggest the need to develop some type of program or service for university students with the aim of preventing depression and improving their adaptation to university life.