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1.
By now, most marine and inland fishery resources have been fully exploited or overexploited. To keep up with the growing demand for fish, only a few avenues for increasing fish production remain open. One of these is the intensification of fisheries in inland waters, such as reservoirs, lakes and small water bodies. Fish species transfer and culture-enhanced fisheries based largely on exotic species, mainly tilapias and cyprinids, is the current common strategy for increasing fishery benefits from tropical and subtropical inland water bodies. The growing human population and rising expectations require a steady growth in the number of reservoirs, both large and small. The development of cage and pen culture, especially in Asia, has substantially increased the reservoir fish production there. In Latin America, tilapias are the mainstay of many reservoir fisheries. By the year 2025, an additional 62 million tonnes of aquatic products will be required to maintain the present consumption of 19.1 kg/person. Much of it will have to come from inland waters, including reservoirs and small water bodies.  相似文献   

2.
The time of origin of cool-to-cold-temperate plants of northern affinities in the Latin American biota is unsettled. Two models have been proposed-a Paleogene origin from a once widespread temperate rain forest, and a Neogene origin by introductions from the north which is best supported by new evidence. Fourteen palynofloras of Tertiary age are now available from Mexico and Central America, in addition to numerous others from the southeastern United States and northern South America. Pollen of cool-temperate plants occurs in the Eocene of southeastern United States, but not in northern Mexico, central Panama, or northern South America. In the Miocene this pollen is sparse in deposits from Mexico and Guatemala, rare in Panama, and absent from northern South America. In the Pliocene pollen representing a diverse northern temperate element of ten genera is present in the Pliocene of southeastern Veracruz, Mexico, five in northeastern Guatemala, and two (Myrica, Salix) first appear in northern South America; Alnus and Quercus are added in the Pleistocene. This north-to-south and early-to-late pattern is consistent with the appearance of highlands in southern Central America and northern South America in the Neogene, closure of the isthmian marine portal between 3.5 and 2.5 Ma (million years ago), and the late Cenozoic cooling trend evident in the O/O-based paleotemperature curve.  相似文献   

3.
In Latin America the small-scale fishery ofmarine benthic invertebrates is based onhigh-value species. It represents a source offood and employment and generates importantincomes to fishers and, in some cases, exportearnings for the countries. In the review, wedefine 2 key concepts: small-scale fishery andco-management. We address the temporalextractive phases which Latin Americanshellfish resources have experienced, and thecorresponding socio-economic and managerialscenarios. We include 3 study cases in whichco-management and field experimentation havebeen used on different temporal and spatialscales: (a) the muricid gastropod (Concholepas concholepas) in Chile; (b) theyellow clam (Mesodesma mactroides) inUruguay; and (c) the spiny lobster (Panulirusargus) in Mexico. We demonstratethat co-management constitutes an effectiveinstitutional arrangement by which fishers,scientists and managers interact to improve thequality of the regulatory process and may serveto sustain Latin American shellfisheries overtime. The main factors supporting co-managementare: (a) a comparatively reduced scale offishing operations and well-defined boundariesfor the management unit; (b) the allocation ofinstitutionalized co-ownership authority tofishers; (c) the voluntary participation of thefishers in enforcing regulations; (d) theimprovement of scientific information(including data from fishers) to consolidatethe management schemes; (e) the incorporation ofcommunity traditions and idiosyncrasies; and (f)the allocation of territorial use rights forfisheries under a collaborative/voluntarycommunity framework. Chile is identified as anexample in which basic ecological and fisheryconcepts have been institutionalized throughmanagement practices and incorporated into theLaw. Several factors have precludedshellfishery management success in most of theLatin American countries: (a) the social andpolitical instability, (b) the underestimationof the role of fisheries science in managementadvice, (c) the inadequacy of data collectionand information systems, (d) the poorimplementation and enforcement of managementpractices and (e) the uncertainty in short-termeconomic issues.In the review, we also show that in LatinAmerica, large-scale fishery experiments arestarting to play an important role in theevaluation of alternative management policieson benthic shellfisheries, especially whenaccompanied by co-management approaches thatexplicitly involve the participation offishers. Fisher exclusion experiments havedemonstrated changes in unexploited versusexploited benthic shellfish populations and inthe structure and functioning of communities.The information has been used by scientists toapproach system elasticity. Ecological andfishery related knowledge has been translatedinto novel co-managerial strategies. Thesedentary nature of the shellfish speciesanalyzed in this review allowed localizedexperiments with different levels of stockabundance and fishing intensity (e.g., marinereserves or maritime concessions versus openaccess areas). This includes the establishmentof closed seasons as de facto managementexperiments, which proved useful in evaluatingthe capacity of passive restocking of depletedareas and for the quantification of populationdemographic features. The precise location offishing grounds provided reliable area-specificestimates of population density and structure,catch, and fishing effort. This allowed theallocation of catch quotas in each fishingground. We also discuss the reliability andapplicability of spatially explicit managementtools. Marine Protected Areas (MPAs) andTerritorial User Rights in Fisheries (TURFs)fulfilled objectives for management andconservation and served as experimentationtools. The examples provided in our reviewinclude a comparative synthesis of the relativeusefulness of alternative spatially explicitmanagement tools under a framework ofmanagement redundancy. The cross-linkagebetween fishery experimental managementprotocols and the active participation offishers is suggested as the strategy to befollowed to improve the sustainable managementof small-scale shellfisheries in Latin America.Finally, we discuss the future needs,challenges and issues that need to be addressedto improve the management status of thesmall-scale shellfisheries in Latin America,and, in general, around the world. We concludethat for the sustainability of shellfishresources there is an urgent need to look forlinkages between sociology, biology andeconomics under an integrated managementframework. Fishers, and not the shellfish, mustbe in the center of such a framework.  相似文献   

4.
Reputations are a ubiquitous feature of human social life, and a large literature has been dedicated to explaining the relationship between prosocial reputations and cooperation in social dilemmas. However, humans form reputations in domains other than prosociality, such as economic competency that could affect cooperation. To date, no research has evaluated the relative effects of multiple reputation domains on cooperation. To bridge this gap, we analyse how prosocial and competency reputations affect cooperation in two Latin American communities (Bwa Mawego, Dominica, and Pucucanchita, Peru) across a number of social contexts (Dominica: labour contracting, labour exchange and conjugal partnership formation; Peru: agricultural and health advice network size). First, we examine the behavioural correlates of prosocial and competency reputations. Following, we analyse whether prosocial, competency, or both reputation domains explain the flow of cooperative benefits within the two communities. Our analyses suggest that (i) although some behaviours affect both reputation domains simultaneously, each reputation domain has a unique behavioural signature; and (ii) competency reputations affect cooperation across a greater number of social contexts compared to prosocial reputations. Results are contextualized with reference to the social markets in which behaviour is embedded and a call for greater theory development is stressed.  相似文献   

5.
The vaccine global market is currently growing at a rate of 16.52%. Nowadays the vaccine manufacturing industry is limited in the sense that not all vaccine manufacturers have the capacity to execute all the steps necessary to produce a successful product. The biological variation inherent to vaccine manufacturing and the initial investment required to bring a vaccine to the market are some of the factors that discourage vaccine manufacturing initiatives.Given the current global context in vaccine innovation and production, and the increasing participation of vaccine manufacturers from developing countries in global markets, this paper aims to review vaccine manufacturing capacity in Latin American and Caribbean (LAC) countries with specific focus on trends in national or public sector manufacturing, presenting current challenges and future opportunities for the sector in meeting national and regional (LAC) needs.Despite the overall low vaccine manufacturing capacity reported within the LAC region within this paper, it is considered that the relatively high and concentrated capacity that exists within a number of countries, combined with political commitment of all countries within the Region, can provide the necessary platform for the continued development of capacity in vaccine development and manufacture within LAC.  相似文献   

6.
1 Correspondence address. E-mail: fzegers{at}clc.cl BACKGROUND: Since 1990, the Latin American Registry of Assisted Reproductioncovers more than 80% of the assisted reproductive technology(ART) cycles performed regionally. METHODS: 130 centers enter their data online, and after collection, itis analyzed and published regionally. RESULTS: This paper analyses trends in ART procedures initiated between1990 and 2004, and babies born up to 2005. Overall, the datainclude 150,000 embryo transfer (ET) cycles, 33,500 deliveriesand the birth of 44,978 babies. The yearly increment in initiatedcycles is below other regions of the world. The economic, religiousand social factors explaining this limited access to ART arediscussed. Major trends include: an increase in the age of femalepartner undergoing treatments; a marked shift towards an increasein the use of ICSI; and a steady increase in the delivery ratesper ET reaching 24.6% in IVF/ICSI cycles, and 30.7% in OD cycles.Despite a slight decrease in the mean number of ET (2.9), almosthalf of all births are either twins or triplets. CONCLUSIONS: Our region is confronted with two main issues: limited accessto those who can afford it; and a high number of embryos transferredresulting in almost 50% of babies born from multiple births.  相似文献   

7.
Global concerns about the depletion of marine stocks have been widely documented in industrial fisheries. However, small-scale artisanal fisheries constitute a second component for the world fishery crisis, normally ignored or erroneously lumped into the industrial component. In this paper we first present a brief comparison between industrial and artisanal fisheries, highlighting the differences between them and the differential feasibility for implementing management options. We propose that industrial and artisanal fishery problems have to be treated separately and thus cannot be lumped into a single “fishing bag”. Among artisanal fisheries, we focus on coastal benthic shellfisheries, highlighting that their sedentary or sessile nature make them amenable to implement spatially-explicit management tools such as rotation of areas and territorial user rights (TURFs). Then, using long-term catch trends and selected examples, we demonstrate the power and validity of co-management for some Latin American shellfisheries, notably in Chile and Mexico, and stress the need to institutionalize the existent fishery knowledge. Several idiosyncratic properties of co-management in our Latin American examples have been useful to sustain the resources over time, including: (a) allocations of TURFs, (b) Community Fishery Quotas, which may be sub-allocated to families, (c) community-based and family-oriented sociological and organizational context of co-management, which may drive short and long-term market forces.  相似文献   

8.
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10.
This paper summarizes the findings for the Latin American and Caribbeancountries of the WPA Task Force on Steps, Obstacles and Mistakes to Avoidin the Implementation of Community Mental Health Care. It presents an overviewof the provision of mental health services in the region; describes key experiencesin Argentina, Belize, Brazil, Chile, Cuba, Jamaica and Mexico; and discussesthe lessons learned in developing community mental health care.  相似文献   

11.
Since 1993, the IAEA supported the establishment or the consolidation of seven tissue banks in the region. As a direct or indirect consequence of the implementation of the IAEA program, more than 53 tissue banks are now operating in the participating countries. The fast development of tissue banks in the Latin America region under the ARCAL Agreement and with the financial and technical support of the IAEA program made it necessary to train new tissue bank operators and medical personnel. In general, 90 tissue bank operators and medical personnel were trained in the training centre of Buenos Aires. Another six tissue bank operators and medical personnel were trained in the International Training Centre of Singapore. The main impact of the IAEA program in the region was the following: the establishment or consolidation of fifty-three tissue banks in nine countries in the region; the implementation of five national projects, allocating $1,006,737 dollars for this purpose and of one regional project allocating $284,741 dollars for this purpose; the use of the IAEA Standards, the IAEA Code of Practice and the IAEA Public Awareness Strategies in several tissue banks in the region; the application of quality control and quality assurances manuals in all of the participating countries.  相似文献   

12.
13.
Throughout human evolutionary history, large-scale migrations have led to intermixing (i.e., admixture) between previously separated human groups. Although classical and recent work have shown that studying admixture can yield novel historical insights, the extent to which this process contributed to adaptation remains underexplored. Here, we introduce a novel statistical model, specific to admixed populations, that identifies loci under selection while determining whether the selection likely occurred post-admixture or prior to admixture in one of the ancestral source populations. Through extensive simulations, we show that this method is able to detect selection, even in recently formed admixed populations, and to accurately differentiate between selection occurring in the ancestral or admixed population. We apply this method to genome-wide SNP data of ∼4,000 individuals in five admixed Latin American cohorts from Brazil, Chile, Colombia, Mexico, and Peru. Our approach replicates previous reports of selection in the human leukocyte antigen region that are consistent with selection post-admixture. We also report novel signals of selection in genomic regions spanning 47 genes, reinforcing many of these signals with an alternative, commonly used local-ancestry-inference approach. These signals include several genes involved in immunity, which may reflect responses to endemic pathogens of the Americas and to the challenge of infectious disease brought by European contact. In addition, some of the strongest signals inferred to be under selection in the Native American ancestral groups of modern Latin Americans overlap with genes implicated in energy metabolism phenotypes, plausibly reflecting adaptations to novel dietary sources available in the Americas.  相似文献   

14.
Augmentative forms of biological control, wherenatural enemies are periodically introduced,are applied over large areas in variouscropping systems in Latin America. About 25%of the world area under augmentative control issituated in this region. Well-known examplesare the use of species of the egg parasitoidTrichogramma for management ofLepidoptera in various crops. In Mexico, forexample, about 1.5 million hectares are treatedwith Trichogramma spp. Application ofTrichogramma also occurs on large areasin Colombia and Cuba, but use is limited inother Latin American countries for economicreasons, the generally low level of educationof farmers, and, more importantly, because ofthe intensive use of pesticides that preventsuse of natural enemies. Of the other eggparasitoids, the main species used incommercial releases are Trissolcusbasalis (Wollaston) against the heteropteranNezara viridula (L.) in soybean inBrazil, and Telenomus remus Nixon againstSpodoptera frugiperda (J.E. Smith) incorn in Venezuela. Natural enemies attackinglarval and pupal stages are not used to a largeextent in augmentative biological control infield crops, with the exception of the use ofCotesia parasitoids against sugarcaneborers in Brazil and several other LatinAmerican countries. In addition to the use ofparasitoids and predators, Latin America isapplying microbial control agents on a largescale, such as viruses for control ofcaterpillars in soybean, fungi for control ofpests in coffee, cotton and sugar cane, andnematodes for control of soil pests. A recentdevelopment in biological control in LatinAmerica is the use of natural enemies andantagonists for disease and pest control inprotected cultivation, for example, inColombia, Brazil and Peru. Up to date, reliablefigures on current use of inundative andseasonal inoculative biological controlappeared hard to obtain, but it is clear thatLatin America currently is a main player in thefield of augmentative releases.  相似文献   

15.
The COVID‐ 19 pandemic is a critical test for the already overburdened and mostly underfunded public healthcare systems of Latin America. In a region that suffers from severe inequalities, public healthcare systems are the only source of medical care for a large sector of the population who work in the informal economy or are unemployed. State‐run hospitals and clinics are already overstressed by continuous demand for treatment of vector‐borne diseases and community‐acquired infections as well as high rates of non‐communicable diseases. Ideological misconceptions and denial among Latin America’s political leaders prevented timely preparations for the pandemic and added to chronic governance problems. As ethical expertise in Latin America focuses on research ethics, few hospitals in the region have functioning clinical ethics committees or clinical ethics policy, forcing healthcare personnel to make excruciating treatment decisions in an environment dominated by material scarcity and public distrust. This essay examines the emergence of COVID‐19 in Latin America and the serious challenge that it poses for Latin America's public healthcare systems.  相似文献   

16.
BACKGROUND: Association between Helicobacter pylori and idiopathic thrombocytopenic purpura (ITP) has been found in Japan and in some European countries. It has also been shown that eradication of H. pylori can increase platelet counts in patients with ITP. The aims of this study were to determine the prevalence of H. pylori infection in patients with ITP in Colombia, and the effect of bacterial eradication on their platelet counts. MATERIALS AND METHODS: Between December 1998 and April 2006, a total of 32 patients diagnosed with ITP were included in the study. Controls were age and sex matched. RESULTS: H. pylori infection in patients with ITP was significantly higher (p = .00006) than in control individuals (90.6% and 43.8%, respectively), as determined by (13)C-urea breath test. A significant association between H. pylori infection and ITP was found (p < .0003), with an odds ratio (OR) of 13.15 (95%CI: 3.24-53.29). Multivariate analysis for the association between H. pylori and ITP showed an OR of 20.44 (95%CI: 3.88-107.49) for women and 19.28 (95%CI: 2.03-183.42) for individuals over 50 years. All 29 H. pylori-positive patients with ITP received eradication treatment. After a median follow up of 12.2 months, 80.8% had a recovery in platelet counts. CONCLUSIONS: According to these results and others from different countries where H. pylori infection rates are high, patients with ITP should be initially tested for H. pylori status, and if present, infection should be eradicated before initiating a drastic conventional ITP treatment. An algorithm for the study and management of patients with ITP in the post-Helicobacter era is presented.  相似文献   

17.
While the amount of reactive nitrogen circulating at the global level has increased markedly in the last century, the effects of this increase are largely seen at the regional level due to interacting ecological and socio-economic factors. In contrast with most other regions of the world, Latin America and the Caribbean (LA-Ca) stand out due to the fact that the major input of reactive nitrogen (Nr) still occurs naturally via biological nitrogen fixation (BNF) in natural ecosystems as opposed to anthropogenic inputs of synthetic fertilizer, fossil fuel combustion and cropping with leguminous species. Largely due to economic reasons, the consumption of fertilizer N in the LA-Ca region is still low in comparison with the average consumption of the world. However, the fertilizer N consumption is increasing at a much faster rate than that in developed regions of the world, like USA and Canada. The Nr production through BNF in cultivated plants that fix nitrogen (C-BNF) is 5 times lower than that occurring naturally in Latin America, but is still equivalent to 16% of the world C-BNF. The cultivation of nitrogen-fixing crop species in the LA-Ca region is also increasing, almost entirely due to the expansion of soybean fields in the central and northern regions of Brazil and the Pampa region of Argentina. Other anthropogenic activities in the region that contribute to an increase in the circulation of reactive nitrogen include the impact of biomass burning and urbanization. In the last decade, an average of 47,000 km2 per year of forests was burned in the LA-Ca region. The environmental impact of urban centers in the LA-Ca region has become very important, since an intense urbanization process is occurring in this region, at an intensity that far exceeds urban development in the northern hemisphere. The consequences of increased urbanization include increased emissions of NO x to the atmosphere due to the fossil fuel combustion, and the lack of sewage treatment facilities in most cities of the LA-Ca result in a large volume of untreated sewage discharged into surface waters, creating serious environmental problems. The combination of rapid urbanization and agricultural intensification in this region suggest that concern is warranted for the potential for increase in the circulation of reactive nitrogen in the very near future. At the same time, the opportunity still exists to mitigate some of the consequences of human impact on the nitrogen cycle in a region that still maintains a large fraction of its natural ecosystems intact.  相似文献   

18.
Invasive alien weeds pose a serious threat to the biodiversity of natural ecosystems and a significant constraint to agricultural production worldwide. The use of co-evolved natural enemies, a strategy referred to as classical biological control (CBC), has proven to be a potentially efficacious, cost-effective, and safe option for the management of alien weeds. An analysis of CBC of invasive weeds in Latin America is presented, which shows that only 5% of the worldwide releases of agents, overwhelmingly arthropod, have been in this region. Fungal pathogens are increasingly being considered in CBC programmes, and there are now 11 examples of Latin American fungi having been released as biocontrol agents in other regions of the world. In contrast, only three weed pathogens have been deliberately released in the region. Possible reasons for the paucity of CBC programmes in Latin America are presented, despite the presence of a significant number of alien weed species (60 are listed). An analysis of these weeds reveals that many of them could be amenable to control using natural enemies, including nine weed species for which CBC programmes have been successfully implemented elsewhere in the world. In addition, for many of these 60 species, a co-evolved and damaging mycobiota has already been recorded. The prospects for management of invasive alien weeds in Latin America, using co-evolved fungal pathogens, are assessed with particular reference to selected species from the genera Ambrosia, Broussonetia, Calotropis, Commelina, Cyperus, Dichrostachys, Echinochloa, Pittosporum, Rottboellia, Rubus, Sonchus and Ulex. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

19.
This study analyses the ethnic identification of children of mixed couples among the Mapuche ethnic group in Chile using census data. The Mapuche are characterized by high exogamy, providing an extreme case of the Latin American pattern of tolerance towards intermarriage. We find that ethnic identification of children of mixed couples is high although it tends to weaken outside the native homeland. Furthermore, education does not increase the classification of children of mixed couples outside of the ethnic group. These findings contravene not only the Brazilian pattern of whitening but also predictions by assimilation theories, and suggest a process of indigenous awareness for families outside the native homeland.  相似文献   

20.
Genome-wide association studies focused on searching genes responsible for several diseases. Admixture mapping studies proposed a more efficient alternative capable of detecting polymorphisms contributing with a small effect on the disease risk. This method focuses on the higher values of linkage disequilibrium in admixed populations. To test this, we analyzed 10 genomic regions previously defined as related with colorectal cancer among nine populations and studied the variation pattern of haplotypic structures and heterozygosity values on seven categories of SNPs. Both analyses showed differences among chromosomal regions and studied populations. Admixed Latin-American samples generally show intermediate values. Heterozygosity of the SNPs grouped in categories varies more in each gene than in each population. African related populations have more blocks per chromosomal region, coherently with their antiquity. In sum, some similarities were found among Latin American populations, but each chromosomal region showed a particular behavior, despite the fact that the study refers to genes and regions related with one particular complex disease. This study strongly suggests the necessity of developing statistical methods to deal with di- or tri-hybrid populations, as well as to carefully analyze the different historic and demographic scenarios, and the different characteristics of particular chromosomal regions and evolutionary forces.  相似文献   

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