The burden of genetic disorders in India and a framework for community control

With a very large population and high birth rate, and consanguineous marriage favoured in many communities, there is a high prevalence of genetic disorders in India. An estimated 495,000 infants with congenital malformations, 390,000 with G6PD deficiency, 21,400 with Down syndrome, 9,000 with beta-thalassaemia, 5,200 with sickle cell disease, and 9,760 with amino acid disorders are born each year. The prevalence of late-onset multi-factorial disorders (including coronary artery disease, hypertension and psychiatric disorders) is also large. Due to inadequate diagnostic, management and rehabilitation facilities, the burden of these disorders is greater than in Western countries. Although genetic diseases receive little attention from the health services, research funding by the government has been liberal. Community control of common disorders like thalassaemia, Down syndrome, neural tube defects, and muscular dystrophies deserves high priority, and genetic services should be integrated into the existing primary health care and medical services. Most genetic counselling would have to be provided through training physicians who staff the district and medical school hospitals. To ensure future progress, there is a need to establish additional departments of medical genetics in medical schools.     

Genetic services in Ecuador

Ecuador has a population of 12 million inhabitants, composed of a variety of ethnic groups. The majority of the population lives in rural areas. There is a severe deficiency in health services, and most diseases are associated with poor life conditions: malnutrition, parasitic diseases and infections. At the same time, however, chronic diseases, e.g. cancer, have increased in prevalence. Most genetic services are provided by the private sector, which offers clinical genetic consultations and counseling, cytogenetic analyses, a limited number of molecular and biomedical tests, and prenatal diagnosis. Genetic research is centered in the universities of important cities (Quito, Guayaquil and Cuenca). The government sponsors some university research projects but does not conduct health actions in genetics in the community. There is an incipient interest in ethic and legal issues in genetics, such as how to provide modern genomic medicine in a resource-poor country.     

Genetic services in Chile

Demographic changes in Chile have positioned congenital malformations as a major cause of infant morbidity and mortality. At the same time, medical genetics has become increasingly important in relation to the diagnosis and management of individuals with birth defects and hereditary conditions as well as in the study of pathological pregnancies and reproductive problems. In addition, recent advances in genomic research are expanding the relevance of medical genetics to medicine as a whole. This article reviews the clinical genetic resources currently available in Chile; the teaching of genetics in undergraduate, graduate, and continued medical education; some relevant interventions that have taken place in our country, e.g. the expansion of the newborn screening program and the initiation of a folic acid fortification program, and recent efforts to enhance population access to clinical genetics services.     

Genetic services in Colombia

Medical genetic services, including clinical genetics, cytogenetics, biochemical and molecular genetics and paternity testing, are performed in Colombia in the more developed medical schools or university institutions, in nine major cities of the country. Accessibility to genetic services is limited by medical care reimbursement laws which do not cover clinical genetic services nor genetic tests. Paternity testing is performed free of charge by a governmental welfare institution, if a legal claim is made against an alleged father. Basic teaching of genetics in medical schools is mandatory, but is very uneven and limited to the better schools. Postgraduate medical genetic training is offered by four different programs of similar quality. Research is performed on some of the most prevalent genetic conditions and on population genetic issues.     

Genetic services in Mexico City

In the year 2002, the population of Mexico was approaching 103 million inhabitants. Approximately 74% of them live in the cities with a continuous migration from rural to urban areas. Genetic departments are concentrated in the capital and other big cities. In this paper we review the current status of genetic departments in Mexico City, emphasizing the main areas of genetic services offered to the public and involved in research. We also comment on the deficiencies identified and suggest recommendations to improve the quality of the genetic services offered to the Mexican population.     

Genetic services in Latin America

This special issue of Community Genetics reviews some of the most important developments in medical genetics in key countries of Latin America. Contributions to this issue were prepared for a special consultation of the World Health Organization held in Porto Alegre, Brazil, on June 19, 2003. Latin America is a region of medium- to low-income countries characterized by socioeconomic problems, with large segments of the population living in poverty and extreme disparities in the distribution of wealth. A rise in chronic diseases typical of the processes of industrialization and urbanization coexists with the persistence of nutritional and infectious diseases characteristic of poverty and underdevelopment. Over the last 2 decades of the 20th century, birth defects and genetic disorders have increased their share of morbidity and mortality, and tertiary-care-based genetic services have developed in urban areas. Although privatization of health care is eroding the public sector, the public institutions continue to be the main providers of genetic services for the bulk of the population and the leaders in research. The development of clinical genetics in the region is concentrated in tertiary-care centers in large cities, although a recent trend began extending genetic services to the community.     

如何用好土力学——对青年土木工程师谈土力学的理论与应用

针对青年学生和年轻的土木工程师在工程实践中如何使用好土力学的理论这一问题进行了讨论.指出了土力学理论与其它土木工程结构理论的根本区别,以及工程经验和判断力的重要性,并就工程经验和判断力以及如何进行培养展开了讨论.本文还对如何阅读土力学文献和如何选择土力学数学模型进行了论述.最后还列出了Casagrand[2]对实际应用土力学理论的要求.     

Genetic variation in the response to vaccination

Vaccines are the most powerful means to prevent and diminish the burden of infectious disease. However, there are limitations to their use: vaccines are not yet available for all infectious diseases (including human immunodeficiency virus and respiratory syncytial virus), they sometimes lack efficacy, the response to vaccination is limited by maternal antibodies in very young infants, and the response to vaccination is variable or may even be absent in some individuals. This review focuses on genetic factors that determine the variable response to vaccination. The highly polymorphic human leukocyte antigen system, which is involved in antigen presentation, has been researched most in this aspect, and clearly affects the response to vaccination. Other, but less polymorphic pathways involved are the Toll-like receptor pathway, which is involved in antigen recognition and stimulation of the immune system, and the cytokine immunoregulatory network. The heritability, or the proportion of total variance that is due to additive genetic factors, appears to be particularly large for vaccine-induced antibody responses in young infants compared with cell-mediated responses and antibody responses in older, immunologically more mature individuals. Both antibody and cell-mediated responses are not only affected by loci within, but also strongly by loci outside the human leukocyte antigen system. Because most genes that are important in influencing immune responses to vaccination are still unknown, clearly more work is required. A better understanding of the factors that determine an effective response to vaccination may lead to the identification of specific genes and pathways as targets for the development of novel more uniformly effective vaccines.     

Damage assessment in composites through NDE: Some recent studies in India

The non-destructive evaluation (NDE) of composites provides a challenging task due to the multifarious types of damage possible in these structures. The form of damage is quite different from that in metals and requires very often, more than one NDE technique to detect them with confidence. The number of NDE techniques to be used for composites is also quite large. Some recent studies on acousto-ultrasonics, acoustic impact and acoustic emission, carried out in India on glass fibre reinforced plastic (GFRP) composites, showed that damage due to delamination can be characterised quantitatively and its growth can be estimated. This paper presents a brief review of the Indian scene concerning the damage assessment of composite structures along with some important results.     

Castes, migration, immunogenetics and infectious diseases in south India

It has been said that the grandest genetic experiment of nature has been conducted in south India in the name of the caste system. One can expect the frequency of an infectious disease to be equal to the product of the frequencies of various indicated loci/alleles, whether physiological, hormonal or immunological, in an endemic area. The sympatrically isolated caste and sub-caste populations of southern India, with differing origins, migration patterns and breeding habits, differ significantly in their HLA and other immune repertoire and are ideal models to study and test this hypothesis. The prevalence of a number of major infectious diseases, including TB and leprosy, are reviewed in different communities in the light of their genetic history.     

Constant temperature hot-wire anemometer practice in supersonic flows

The performance of a constant-temperature inclined hot-wire in a supersonic flow is critically examined. It is shown that empirical heat transfer correlations commonly used for calibrating hot wires in subsonic flow cannot be used when the flow is supersonic. Calibration and measurement procedures appropriate to supersonic flow are suggested, together with the possible limits on their validity. The instrument was used to measure the mass-weighted Reynolds shear stress in a zero pressure gradient Mach 2.9 turbulent boundary layer. A comparison with the available data suggests good agreement, as long as the normal Mach number remains supersonic under all conditions.     

Constant temperature hot-wire anemometer practice in supersonic flows

The performance of a constant-temperature normal hotwire in a supersonic flow is critically examined. It is shown that this instrument is inherently unsuitable for measuring turbulent temperature correlations because of the highly non-linear response to temperature fluctuations, particularly at low overheat ratios. The instrument is therefore limited to measurements of mean and fluctuating mass-flow rates. Suitable calibration procedures. as well as the limits on spatial and temporal resolution are discussed. and corrections for mean stagnation temperature changes are suggested. The instrument was used to measure the mass-flow fluctuations in a zero pressure gradient Mach 2.9 turbulent boundary layer. A comparison with the available data suggests good agreement.     

漫话中国古代的飞行

在美国莱特兄弟发明飞机百年之际,又有中国``神舟'五号太空飞行,人们自然想到飞行史前阶段人类曾经有过的飞行尝试. 本文叙述古代中国人的有关飞行思想与滑翔飞行的情况,并将原始文献展示读者,以供参读.     

自适应免疫遗传算法

遗传算法(GA)是基于自然遗传规则随机搜索技术的一种进化算法,但是随着实际结构的大型化和复杂化,它往往出现过早收敛的现象。在研究了算法的编码方式、控制参数和算子操作之后,就其全局收敛性的不足,提出动态自适应策略以改进其性能,在基本遗传算子的基础上,采用了免疫遗传算子和保优策略。其中免疫算子可以防止交叉变异中的个体退化,自适应策略则保持了种群的多样性,以此保证遗传算法尽快收敛到全局最优解,称之为自适应免疫遗传算法(AIGA)。随后以经典的十杆桁架结构优化问题作为例子说明算法的优越性,结果表明AIGA在随机结构优化中计算有效、结果可靠。     

遗传算法及其应用

本文简要介绍了遗传算法的主要思想，算法基本步骤以及它的主要特点和应用领域，并以几个桁架结构的优化设计为例，说明了遗传算法的全过程。     

加强实验教学以培养学生的工程素质

对基础力学实验教学进行改革，通过增设工程模拟实验和转化工程课题为实验项目等措施，培养学生的工程意识和工程概念，增强学生的动手能力和解决问题的能力，达到对学生的知识、能力和品质的综合培养，收到很好的效果．     

Genetic patent protection in the pharmaceutical and biotechnology industries

Without patent protection, biomedical progress would be severely diminished. Conditions under the current patent regime are characterized by rapid advancement made possible by cooperative licensing, collaboration and partnerships between and among various entities, and the drive to bring successful products to market both in order to make profits and to further the cause of humanity. The financial advantages associated with patent-driven corporate participation are the lifeline of innovation. While granting limited periods of exclusivity under the patent system necessary to entice innovation is a calculated sacrifice, the enormous benefits of fully-disclosed pharmaceutical and genetic discoveries result in a handsome net benefit over the alternative of resource-limited research clouded by a shroud of secrecy as a substitute for patent protection. By examining characteristics of the pharmaceutical and biotechnology industries and the critical role the patent regime plays in driving investment in these areas, a clearer picture of the necessity of strong intellectual property rights in the context of genetics will emerge.     

结构优化的GA算法

本文提出了一种用于结构优化的具有动态种源空间的ＧＡ算法，这种ＧＡ算法可以与其它结构优化方法如齿行法结合起来处理结构优化问题。这种ＧＡ具有很好的鲁棒性和较高的效率，可作为一个黑箱处理相当广泛的结构优化问题。