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1.
Strains of Salmonella spp. with resistance to antimicrobial drugs are now widespread in both developed and developing countries. In developed countries it is now increasingly accepted that for the most part such strains are zoonotic in origin and acquire their resistance in the food-animal host before onward transmission to humans through the food chain. Of particular importance since the early 1990s has been a multiresistant strain of Salmonella typhimurium definitive phage type (DT) 104, displaying resistance to up to six commonly used antimicrobials, with about 15% of isolates also exhibiting decreased susceptibility to ciprofloxacin. Mutations in the gyrA gene in such isolates have been characterised by a PCR LightCycler-based gyrA mutation assay, and at least four different mutations have been identified. Multiple resistance (to four or more antimicrobials) is also common in the poultry-associated pathogens Salmonella virchow and Salmonella hadar, with an increasing number of strains of these serotypes exhibiting decreased susceptibility to ciprofloxacin. Multiple resistance is also being found in other serotypes in several other European countries, and has been associated with treatment failures. For Salmonella typhi, multiple drug resistance is now the norm in strains originating in the Indian subcontinent and south-east Asia. Such multiresistant strains have been responsible for several epidemics and some of these have been associated with contaminated water supplies. Furthermore, an increasing number of multiresistant strains of S. typhi are now exhibiting decreased susceptibility to ciprofloxacin, with concomitant treatment failures. In developed countries antimicrobial resistance in zoonotic salmonellas has been attributed to the injudicious use of antimicrobials in food-producing animals. It is hoped that the application of Codes of Practice for the use of such agents, which have been prepared by the pharmaceutical industry in response to widespread international concern about the development of drug resistance in bacterial pathogens, will now result in a widespread reduction in the incidence of drug-resistant salmonellas in food production animals and humans on an international scale.  相似文献   

2.
中国水果和蔬菜昆虫授粉的经济价值评估   总被引:6,自引:0,他引:6  
安建东  陈文锋 《昆虫学报》2011,54(4):443-450
水果和蔬菜是二大类最主要的虫媒作物, 在农业生产中占据十分重要的地位, 但是近几十年来授粉昆虫在多国出现了不同程度的下降, 影响了农业生产的经济效益。为了明确中国主要授粉昆虫的现状以及昆虫授粉在中国水果和蔬菜生产中的经济地位, 本文分析了1961-2009年间中国主要授粉昆虫蜜蜂的数量动态以及水果和蔬菜种植的变化特征; 并以2008年种植的与人类食品密切相关的44种水果和蔬菜为研究对象, 引入农作物对昆虫授粉的依赖性参数, 应用生物经济学的方法评估了昆虫授粉对中国水果和蔬菜产生的经济价值。结果表明: 1961-2009年的49年之间, 中国主要授粉昆虫蜜蜂蜂群数量增加了161%, 水果和蔬菜种植面积增加了472%, 产量增加了833%。中国水果和蔬菜中虫媒作物产量的提高, 与作物种植面积的增长密切相关(r=0.995, P<0.01), 也与主要授粉昆虫蜜蜂蜂群数量增加有关(r=0.804, P<0.01)。2008年昆虫授粉对中国水果和蔬菜产生的经济价值为521.7亿美元, 占44种水果和蔬菜总产值的25.5%。水果类对昆虫授粉的依赖程度较高, 授粉产生的经济价值大于蔬菜类。在昆虫授粉的贡献中, 苹果、西瓜、梨、芒果和李占据前5位。昆虫授粉对中国水果和蔬菜产生的经济价值十分巨大, 中国水果和蔬菜对昆虫授粉的依赖程度超过15.9%的全球平均水平。随着中国水果和蔬菜种植面积的持续增长, 中国需要更多的授粉昆虫为其提供授粉服务。  相似文献   

3.
Russia, Ukraine and a number of neighboring countries formed the Soviet Union, or USSR, until 1989, when what was both a political and an economic catastrophe saw the Union fragment into a number of independent states. Following constitutional reforms in 1990, what remained was now called the Russian Federation and, at 17,172,200?sq. km, it was the largest country by area in the entire world, covering an eighth of the entire inhabited land surface. In 1991, notably, Ukraine became an independent state. Neither country any longer had a communist government, but both were burdened with unproductive economies that made daily life difficult for most citizens. The papers in this collection emphasize the dominant effect of economic deficits on the conduct of daily life in both countries, and discusses some visual aspects of various subcultures.  相似文献   

4.
Therapeutic applications of genomic medicine are slowly finding their way into the healthcare framework of developing countries. The establishment of equitable innovation policies is a determining factor in how genomic-based therapeutic applications will evolve in these countries. In the biomedical field, the commercialization of research results has established itself as the dominant paradigm in the innovation system. However, many recent studies have demonstrated that this emphasis on commercialization and the protection of intellectual property has led to disappointing results. A growing number of stakeholders in this debate argue that it is now necessary to go beyond the commercialization of research and implement policies based on the research valorization paradigm, which supports the achievement of social as well as economic objectives. We thus propose a new set of more inclusive research performance indicators to help policymakers measure the impact of international genomics projects on developing countries.  相似文献   

5.
世界卫生组织(World Health Organization,WHO)总干事谭德塞在2022年新年寄语中表示,他对人类在2022年战胜2019冠状病毒病(coronavirus disease 2019, COVID-19)疫情持乐观态度,认为人类有望在这一年结束疫情。经过2年时间,目前全球COVID-19病例总数达到了2.87亿,近550万名患者丧生。在步入2022年之际,遏制严重急性呼吸综合征冠状病毒2 (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2)的传播仍然是人们日常生活的一部分,谭德塞总干事认为只要各国联手就可以抑制病毒蔓延。  相似文献   

6.
Although much newsprint is devoted to the subject of reducing the United States and other major developed countries dependence on their respective foreign energy sources; the most challenging issues for society is to provide long-term, sustainable energy sources to accommodate the global population as a whole. The projected population of planet Earth for the year 2050 is estimated to be in excess of 9 billion. With hydrocarbon-based energy becoming limiting it is unlikely that one type of energy will alone replace our dependence on this source. So-called "green" technologies that include solar, wind and wave powers are now being explored to reduce on traditional hydrocarbon-based fuel sources. The diverse and functional properties of microbes, and in particular anaerobes, are now being utilized in the production of biofuels and may provide one piece of the jigsaw for future energy requirements. Here we present some results of a screening program to identify and characterize a number of carbon monoxide oxidizing, ethanol-producing acetogenic anaerobes phylogenetically located within the Clostridiales.  相似文献   

7.
The use of genetic information is now fundamental in parasite taxonomy and systematics, for resolving parasite phylogenies, discovering cryptic species, and elucidating patterns of gene flow among parasite populations. The accumulation of available gene sequences per geographical area or per parasite taxonomic group is likely proportional to species richness, but not without some biases. Certain areas and certain taxonomic groups receive more research effort than others, possibly causing a deficit in the relative number of parasite species being characterized genetically in some areas or taxonomic groups. Here, we use data on the number of parasite records per country or helminth family from the London Natural History Museum host-parasite database, and matching data on the number of gene sequences available from the National Center for Biotechnology Information (NCBI) GenBank database, to determine how available gene sequences scale with species richness across countries or parasitic helminth families. Our quantitative analysis identified countries/regions of the world and helminth families that have received the most effort in genetic research. More importantly, it allowed us to generate lists (based on residuals from the statistical model) of the 20 countries/regions and the 20 helminth families with the largest deficit in available gene sequences relative to their helminth species richness. We propose these lists as useful guides toward future allocation of effort to maximise advances in parasite biodiscovery, systematics and population structure.  相似文献   

8.

Background  

The advent of live-attenuated vaccines against measles virus during the 1960'ies changed the circulation dynamics of the virus. Earlier the virus was indigenous to countries worldwide, but now it is mediated by a limited number of evolutionary lineages causing sporadic outbreaks/epidemics of measles or circulating in geographically restricted endemic areas of Africa, Asia and Europe. We expect that the evolutionary dynamics of measles virus has changed from a situation where a variety of genomic variants co-circulates in an epidemic with relatively high probabilities of co-infection of the individual to a situation where a co-infection with strains from evolutionary different lineages is unlikely.  相似文献   

9.
Malaria continues to be one of the most serious and widespread parasitic diseases, still occurring in over 100 countries despite concentrated efforts to eradicate it from many regions. Sixty-one countries now report their malaria cases to the WHO, and the latest analysis of these figures' shows little improvement in the overall problem during the last 15 years. Some countries, notably India and China, continue to report downward trends, but the problem continues to deteriorate in rural areas where intense economic development is taking place, particularly in Asia and the Americas. In 1984, 5.3 million cases of malaria were reported to the WHO. This is believed to represent but a small fraction of the total number because, for example, 38 of the tropical African countries do not report their malaria cases. Estimates based on the degree of malaria endemicity suggest a total incidence o f around 100 million cases annually. Chloroquine-resistant falciporum malaria has been confirmed in more than 40 countries, often showing cross-resistance to other drugs, and attempts to combat resistance using combination drugs have led to disturbing reports of side-effects as well as multidrug resistance. Vector control is also impaired in many areas due to insecticide resistance. Faced with these problems, we asked Dr Walther Wernsdorfer, head of the WHO Malaria Action Programme, what is the current WHO philosophy of malaria chemotherapy and prophylaxis?  相似文献   

10.
Commercialization of plant tissue culture in India   总被引:2,自引:0,他引:2  
Commercial application of plant tissue culture started in USA with micropropagation of orchids in 1970s. It has seen tremendous expansion globally from 1985 to 1990 in the number of production units as well as the number of plants produced. With an estimated global market of 15 billion US dollars per annum for tissue cultured products, even with exponential expansion in the industry, the demand far exceeds production, leaving enough scope for expansion. This industry appears to be undergoing a pause in growth presently in developed countries as it is finding difficult to remain cost–effective. In US, only half the production capacity is being utilized currently due to high labour costs. In developing countries, with lower wage scales, plants are being produced at much cheaper rates. Indian micropropagation industry, though a late starter by almost a decade, compared to its western counterparts, has expanded exponentially from 5 million annual capacity in 1988 to 190 million in 1996. The facilities now created are at par with the best in leading countries like the Netherlands and USA. To remain in profitable business and to earn the much needed foreign exchange, Indian units need to judiciously mix steady revenue generating items with unique speciality items based on demand in domestic and international markets. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

11.
One of the prime requirements for effective study of environmental geochemistry in relation to health is the production of multi-element atlases showing the distribution of the elements on the regional scale. The choice of method for compiling such atlases can vary according to a number of geological, environmental and other factors. The overriding consideration, however, is to assist (in conjunction with other relevant sources of information) in defining, quickly and cheaply, potential problem areas wherein to concentrate more detailed studies to ensure maximum return from the funds and scientific manpower available. Numerous sampling and analytical techniques have been employed. Each technique and approach has its own scope, limitation and problems of interpretation. Whatever method is chosen, the use of computer-based statistical data reduction, analysis and map compilation is mandatory. Although it was apparent more than 20 years ago that geochemical atlases would eventually become a national cartographic requirement, regional geochemical mapping is still in the experimental stage. This trend is now evident in activity in a number of countries. The methods being employed, however, are so diverse that there is an urgent need for international collaboration aimed at securing data that are as mutually compatible as possible, having regard to the conditions, needs and resources of the individual countries involved.  相似文献   

12.
The threat from creationism to the rational teaching of biology   总被引:2,自引:0,他引:2  
Most biologists outside the USA and a few other countries, like Australia and Canada, are under the impression that the threat to the teaching of biology represented by creationism does not concern them directly. This is unfortunately no longer true: the recent growth of creationism, especially in its pseudo-scientific manifestation known as "intelligent design", has been obvious in several countries of Western Europe, especially the UK, Germany and Poland, and it is beginning to be noticeable in Brazil, and maybe elsewhere in Latin America. The problem is complicated by the fact that there are not just two possibilities, evolution and creationism, because creationism comes in various incompatible varieties. Turkey is now a major source of creationist propaganda outside the USA, and is especially significant in relation to its influence on Muslim populations in Europe. The time for biologists to address the creationist threat is now.  相似文献   

13.
A basic knowledge of regional faunas is necessary to follow the changes in macroinvertebrate communities caused by environmental influences and climatic trends in the future. We collected all the available data on water bugs in Hungary using an inventory method, a UTM grid based database was built, and Jackknife richness estimates and species accumulation curves were calculated. Fauna compositions were compared among Central-European states. As a result, an updated and annotated checklist for Hungary is provided, containing 58 species in 21 genera and 12 families. A total 66.8% of the total UTM 10 × 10 km squares in Hungary possess faunistic data for water bugs. The species number in grid cells numbered from 0 to 42, and their diversity patterns showed heterogeneity. The estimated species number of 58 is equal to the actual number of species known from the country. The asymptotic shape of the accumulative species curve predicts that additional sampling efforts will not increase the number of species currently known from Hungary. These results suggest that the number of species in the country was estimated correctly and that the species accumulation curve levels off at an asymptotic value. Thus a considerable increase in species richness is not expected in the future. Even with the species composition changing the chance of species turn-over does exist. Overall, 36.7% of the European water bug species were found in Hungary. The differences in faunal composition between Hungary and its surrounding countries were caused by the rare or unique species, whereas 33 species are common in the faunas of the eight countries. Species richness does show a correlation with latitude, and similar species compositions were observed in the countries along the same latitude. The species list and the UTM-based database are now up-to-date for Hungary, and it will provide a basis for future studies of distributional and biodiversity patterns, biogeography, relative abundance and frequency of occurrences important in community ecology, or the determination of conservation status.  相似文献   

14.
The dramatic increase in the world's population that has occurred over the past 100 years has come largely through reductions in death due to infectious disease. An epidemiologic transition to a preponderance of deaths due to degenerative conditions such as cardiovascular disease and cancer is occurring in the developing countries as well as in the industrialized ones. In the industrialized countries, demographic profiles now reflect the increased life expectancies of both sexes. However, female life expectancies exceed male by six or more years. Further change in mortality patterns will accompany success in the reduction of the number of mortalities attributable to such degenerative conditions as cardiovascular disease and cancer. In the 21st century, conditions associated with sensescence will be of increasing concern. Adaptive strategies that enhanced reproductive success throughout most of human evolution may now prove detrimental to human health as average life expectancies reach unprecedented length. In this environment, differences in the survival mechanisms deployed by males as opposed to females will become increasingly important.  相似文献   

15.
Health experts fear epidemics of several infectious diseases in Mozambique as floods recede and mosquitoes begin breeding. According to Pierre Kahozi of WHO, malaria is already endemic in the region but there are fears that a much greater outbreak might occur. Scores of suspected cases of cholera were reported and more are expected, along with cases of other diarrheal conditions. Neil Cameron, chief director of communicable diseases at the health department in South Africa, said that more cases are expected within a month when the breeding cycle of mosquitoes is renewed. He reported that the number of malaria cases in South Africa increased from 12,000 in 1995 to 50,000 in 1999, and a number of people had been dying from this disease. The increase could be attributed partly to climatic changes and resistance to certain drugs. DDT had been used in the past to control mosquitoes, and it?s possible that it will be used again in Mozambique. The issues involved in tackling malaria are now being considered as part of a special development initiative on infectious diseases that is being undertaken jointly by the health departments of three countries: South Africa, Mozambique, and Swaziland.  相似文献   

16.
Personality disorder is now being accepted as an important condition in mainstream psychiatry across the world. Although it often remains unrecognized in ordinary practice, research studies have shown it is common, creates considerable morbidity, is associated with high costs to services and to society, and interferes, usually negatively, with progress in the treatment of other mental disorders. We now have evidence that personality disorder, as currently classified, affects around 6% of the world population, and the differences between countries show no consistent variation. We are also getting increasing evidence that some treatments, mainly psychological, are of value in this group of disorders. What is now needed is a new classification that is of greater value to clinicians, and the WPA Section on Personality Disorders is currently undertaking this task.  相似文献   

17.
Echinococcosis: an emerging or re-emerging zoonosis?   总被引:24,自引:0,他引:24  
The aim of this review is a critical discussion of factors actually or potentially contributing to persistence or emergence of echinococcosis in humans. Alveolar echinococcosis (AE), a life-threatening infection of humans, is caused by a larval stage of Echinococcus multilocularis. The adult parasite inhabits the intestine of foxes and other carnivores and has a wide distribution in the northern hemisphere (North America and northern and central Eurasia). Recent surveys in central Europe have extended the known geographical occurrence of E. multilocularis in foxes from four countries at the end of the 1980s to at least 11 countries in 1999. Cases of human AE previously regularly reported from only four countries are now recorded from seven countries, but the annual incidences are low. Since adequate information from earlier surveys is not available, it is not possible to conclude if the new findings reflect a recent extension of the parasite's range or just the first identification of hitherto unnoticed endemic areas. Evidence of parasite spreading has been reported from North America and Japan. Factors with the potential of enhancing the infection risk for humans in the future include increasing fox populations and parasite prevalences, progressing invasion of cities by foxes, the establishment of urban cycles of the parasite, and the spill-over of the E. multilocularis infection from wild carnivores to domestic dogs and cats. In view of the potential severity and fatality of AE in humans health authorities should initiate internationally coordinated countermeasures. Although control programmes against human cystic echinococcosis (CE), caused by E. granulosus, have been established in some countries and effective control strategies are available, the parasite has still a wide geographical distribution affecting many countries of all continents. Thus, human CE is persisting in many parts of the world with high incidences, and in some areas it is a re-emerging problem. For example, alarming increases of the number of human cases have been reported from Bulgaria and Kazakhstan, and the People's Republic of China. Progress in control can only be expected if health authorities attribute a higher priority to this disease and if all modern diagnostic and control options (for example vaccination of intermediate host animals) can be used.  相似文献   

18.
Environmental biotechnology: the ongoing quest   总被引:7,自引:0,他引:7  
Environmental biotechnology, until now, has primarily focused on the development of technologies to treat aqueous, solid and gaseous wastes. At present, the basic knowledge on how biotechnology can handle these wastes has been acquired and the focus is now on the implementation of these processes as 'best available technology not entailing excessive costs' (BATNEEC) in the framework of strict and transparent environmental legislation. New environmental challenges continue to evolve, as it becomes clear that waste streams should be tackled in an overall holistic way. New technologies to reach this goal are currently under development. Novel aspects with respect to the domain of water treatment are, for example, the biomembrane reactor technology and the newly discovered processes to remove nitrogen by means of anaerobic ammonium oxidation. Also, most challenging is the continuing strive for re-use of treated wastewater. Indeed, water shortage is emerging in an increasing number of countries all over the world and necessitates the short cycling of water. Finally, biotechnology has a key role to play in the novel approaches to design wastewater treatment based on decentralised sanitation and reuse (DESAR). Solid waste is a major challenge worldwide. The implementation of anaerobic digestion to treat biowastes has become a grown-up technology. New approaches in which biotechnological processes are linked to physical processes, such as plasma technology, certainly deserve special attention for the coming decades. Soil and sediment clean up by means of biostimulation/remediation/augmentation is now well established. Certainly, a number of prospects need to be further explored, such as the use of special energy sources to stimulate in situ the microbial community and the seeding of knowledge to the in situ community by means of horizontal gene transfer mechanisms. A number of waste gases can be handled by biofilter systems. Biological treatment of wastegases is also evolving, inasmuch as that besides conventional chemical pollutants, now also highly problematic chemicals (even dioxins) can be dealt with through proper biotechnological approaches. A remarkable new potential is the use of well designed probiotics to upgrade aquaculture and together with conventional biological water treatment processes, to guarantee the overall water quality of this domain of food production.  相似文献   

19.
The Japanese earthquake and tsunami drew attention worldwide to nuclear power plant accidents and associated health risks. Since Chernobyl 25 years ago, several studies were published and we now have precise information concerning the long-term health of the population living near nuclear power plants and also in different European countries. The authors hope to bring some answers to the key questions from the public concerning radioactive units used and their significance, the evaluation of the number of radio-induced cancers within the different countries of Europe, other eventual health effects and the problem of possible congenital anomalies. Finally, French public perception on nuclear risk is examined and the feedback of the Japanese experience is evoked.  相似文献   

20.
The commercial exploitation of seaweeds for use as food and for the production of agar, alginate and carrageenan is outlined. The quantities of seaweed harvested for each purpose are tabulated and discussed. Seaweeds for food are derived chiefly from China, Japan and Korea, with almost 94% obtained by cultivation. Alginophytes are collected in 15 countries but six of these account for more than 80% of the total harvest; all are from natural stocks except for a large quantity of Laminaria cultivated in China. Natural carrageenophytes, from 12 countries, now account for only 20% of the total harvest; the remainder is cultivated Eucheuma species, 99% of which is produced in only two countries, the Philippines and Indonesia. Of the four categories of commercial resources of seaweeds considered, agarophytes are spread more evenly over a greater number of countries; they come from 20 countries and only five of these are minor contributors to the total. Gelidium species are particularly important because of the high quality agar they yield; their distribution and location are discussed.  相似文献   

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