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1.
Uffe Nielsen Ole Mertz Gabriel Tonga Noweg 《Human ecology: an interdisciplinary journal》2006,34(2):201-218
This paper reviews the theoretical and empirical literature on labor productivity in shifting cultivation systems, and relationships between labor productivity and production parameters are analyzed in two case studies of Iban communities in Sarawak, Malaysia, during two farming seasons. In addition, the labor productivity in shifting cultivation compared to off-farm wage labor opportunities is explored. Establishing firm relationships between labor productivity and production parameters, such as fallow length, fertilizer use, and herbicide use was not possible. We are thus unable to verify or reject the thesis that more labor is required for managing fields after short fallow compared to long fallow periods. We do demonstrate that shifting cultivation of hill rice can compete economically with common off-farm employment opportunities, and conclude that farmers’ decisions to maintain their practices is based as much on economic rationales as on tradition. 相似文献
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Mario Giampietro Sandra G. F. Bukkens David Pimentel 《Human ecology: an interdisciplinary journal》1993,21(3):229-260
A model of energy analysis is presented to study the concept of labor productivity from a biophysical perspective. It is argued that current methods of defining and assessing labor productivity in the fields of work physiology and input/output energy analysis are relatively poor operational tools for assessing productivity in the economy and society. We propose to adopt society as the hierarchical level of analysis rather than the individual, as labor productivity can best be studied as a function of parameters related to the technological development of society. Parameters considered are: the ratio exosomatic/endosomatic energy used in society, the ratio working/non-working population, the return on the circulating energy investment, and the profile of human time allocated to the economic process. The links between patterns of human time allocation, population structure, standard of living, technological development, and demand on natural resources are analyzed. The results suggest that the role and meaning of human labor differ widely in societies with different levels of technological development. 相似文献
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S. E. Halcrow N. J. Harris N. Tayles R. Ikehara‐Quebral M. Pietrusewsky 《American journal of physical anthropology》2013,150(3):409-420
Many bioarchaeological studies have established a link between increased dental caries prevalence and the intensification of agriculture. However, research in Southeast Asia challenges the global application of this theory. Although often overlooked, dental health of infants and children can provide a sensitive source of information concerning health and subsistence change. This article investigates the prevalence and location of caries in the dentition of infants and children (less than 15 years of age) from eight prehistoric mainland Southeast Asian sites collectively spanning the Neolithic to late Iron Age, during which time rice agriculture became an increasingly important subsistence mode. Caries prevalence varied among the sites but there was no correlation with chronological change. The absence of evidence of a decline in dental health over time can be attributed to the relative noncariogenicity of rice and retention of broad‐spectrum subsistence strategies. No differences in caries type indicating differences in dental health were found between the sites, apart from the Iron Age site of Muang Sema. There was a higher prevalence of caries in the deciduous dentition than the permanent dentition, likely due to a cariogenic weaning diet and the higher sensitivity of deciduous teeth to decay. The level of caries in the permanent dentition suggests an increased reliance on less cariogenic foods during childhood, including rice. The absence of a temporal decline in dental health of infants and children strengthens the argument that the relationship between caries and agricultural intensification in Southeast Asia was more complex than the general model suggests. Am J Phys Anthropol, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
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J. Piesse C. Thirtle 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2010,365(1554):3035-3047
The relationships between basic and applied agricultural R&D, developed and developing country R&D and between R&D, extension, technology and productivity growth are outlined. The declining growth rates of public R&D expenditures are related to output growth and crop yields, where growth rates have also fallen, especially in the developed countries. However, growth in output value per hectare has not declined in the developing countries and labour productivity growth has increased except in the EU. Total factor productivity has generally increased, however it is measured. The public sector share of R&D expenditures has fallen and there has been rapid concentration in the private sector, where six multinationals now dominate. These companies are accumulating intellectual property to an extent that the public and international institutions are disadvantaged. This represents a threat to the global commons in agricultural technology on which the green revolution has depended. Estimates of the increased R&D expenditures needed to feed 9 billion people by 2050 and how these should be targeted, especially by the Consultative Group on International Agricultural Research (CGIAR), show that the amounts are feasible and that targeting sub-Saharan Africa (SSA) and South Asia can best increase output growth and reduce poverty. Lack of income growth in SSA is seen as the most insoluble problem. 相似文献
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Claire Aubron Hubert Cochet Gilles Brunschwig Charles -Henri Moulin 《Human ecology: an interdisciplinary journal》2009,37(4):407-419
Globalization induces changes in the combinations of productions and activities within farming systems in all parts of the
world. These changes can only be apprehended through an in-depth understanding of the mechanisms and diversity of these farming
systems. Labor, as a major technical determinant of differences in competitiveness, is central in these transformations. The
technical and economic analysis of labor in Andean dairy production in this paper illustrates this issue. Combining various
scales of analysis of labor and productivity highlights the technical obstacles faced by Andean dairy farmers, demonstrates
the technical and economic principles of these production systems, and puts them in a competitive context. This analysis also
discusses the benefits of a labor-centered approach of farming systems.
相似文献
Charles -Henri MoulinEmail: |
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一、自然背景与发展特征豫西地区属黄土高原的东延部分,总面积约2.68×10~4km~2,共有耕地8.0×10~5ha多,是河南省典型的丘陵山区,亦是河南省重要的农业生产基地。本区地处暖温带,气候具有明显的大陆性半干旱特征。年降雨量稍高于晋陕黄土高原,多在500—900mm之间,但年际差异大,年内雨量分配不均;山区常年平均温度6—12℃,丘陵和河谷阶地12—14℃,水热资源尚属丰富,适宜农业发展。这里的农业从以放牧形式 相似文献
8.
AMY DOWNING MEISNER 《Zoological Journal of the Linnean Society》2001,133(2):199-283
Among the 13 genera and over 100 species of halfbeaks, three genera - Dermogenys, Nomorhamphus and Hemirhamphodon – are internally fertilized and viviparous. These genera belong to a more inclusive clade, the Zenarchopterinae, that also includes Zenarchopterus , inferred to be internally fertilized and to lay fertilized eggs, and the monotypic Tondanichthys , also inferred to be internally fertilized. Whereas the Hemiramphidae are distributed worldwide, internally fertilized halfbeaks are restricted to Southeast Asia. Recent data from histological surveys of the gonads of both males and females as well as embryonic modifications associated with viviparity have been combined here with osteological characters in a phylogenetic analysis. Results indicate overwhelming support for a sister-group relationship between Hemirhamphodon and {Dermogenys + Nomorhamphus). Monophyly of the Dermogenys + Nomorhamphus clade is also well supported. These results confirm earlier suggestions that Dermogenys , as previously defined, is paraphyletic. Within the Dermogenys + Nomorhamphus clade, two monophyletic clades are supported:one comprises ten species including four new species (Dermogenys bruneiensis, Dermogenys robertsi, Dermogenys palawanensis and Dermogenys collettei) and the other comprises 13 species including three undescribed species (Nomorhamphus rossi, Nomorhamphus pinnimaculata and Nomorhamphus manifesta). Diagnoses for the species of Dermogenys and Nomorhamphus , as well as a natural classification for the included species, are presented. 相似文献
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广州市农业可持续发展问题与对策 总被引:3,自引:0,他引:3
近20年来,广州农业发展很快,粮食、蔬菜、水果和肉、蛋、奶等产量迅速提高,农业结构和基础设施较好,但是也面临着耕地不断减少,农业环境污染,服务体系滞后,农业生产不适应现代化水平要求等,为此,必须推进农村土地股份制,发展可持续农业科技,改善农业生态环境等对策。 相似文献
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The false spider crabs of the family Hymenosomatidae are one of the most poorly known group of brachyuran crabs in Southeast Asia. This is largely attributed to their small size and cryptic behaviour. Despite the many studies of decapods in Southeast Asia, only eleven species of hymenosomatids are known. Of these, two genera and six species were only described in the last two years. From Singapore the largest number of species (five) has been reported probably because it has been the best explored, while from Thailand three species and Peninsular Malaysia two species are known. There are no published records of hymenosomatids from Borneo or Java. The hymenosomatid fauna is perhaps best known in Australia and New Zealand. It is anticipated that when proper collections are made and studies implemented, the Southeast Asian hymenosomatid fauna will prove to be more diverse than what has been reported. The ecology of the Southeast Asian species is reviewed, especially in the view that two species are completely freshwater, one of which is a troglobite. Most species are littoral or sublittoral in habit and very sensitive to human activities (e.g. pollution). 相似文献
11.
T Hanihara 《American journal of physical anthropology》1992,88(2):183-196
Five evolutionarily significant dental traits were identified from a B-square distance analysis of nine crown characters recorded for several populations of East Asia and Oceania. Intergroup variation in these traits distinguishes three major divisions of the Mongoloid dental complex: sundadonty, sinodonty, and the dental pattern of Australian Aborigines. The Australian crown features may be characterized as having high frequencies of evolutionarily conservative characters. Negritos, one of the probable representatives of indigenous inhabitants of Southeast Asia who may have shared a common ancestor with Australians, possess the more derived sundadont dental pattern. As far as the five crown traits treated here are concerned, Australian dental features may be described as conforming to a "proto-sundadont" dental pattern, applying Turner's terminology. This pattern may represent a microevolutionary step prior to the emergence of the sundadont and sinodont patterns. 相似文献
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Anna Fourage Chris R. Shepherd Marco Campera K. A. I. Nekaris Vincent Nijman 《Zoo biology》2023,42(2):283-295
Conservation education programs are listed as priority actions for almost every threatened species on the International Union for Conservation of Nature Red List. Zoos play an important role in delivering such programs, yet evidence of zoo education in many non-western countries is limited. Here, we evaluate animal identification signage prevalence and quality at zoo exhibits and investigate whether animal welfare, zoo type (accredited, government, and private), admission fee, zoo size, and proximity to urban centers are influencing factors. We used hornbills (Bucerotidae) as a model taxon, surveyed hornbill signage, and conducted welfare assessments of hornbill exhibits. We developed scoring frameworks and applied content analysis to analyze signage quality. Our results show that out of 18 zoos that displayed hornbills, 15 had hornbill signage. However, of the 106 hornbill exhibits in these zoos, 33% had no signage. We also found that signage presence or absence at individual zoos and signage quality is strongly correlated with animal welfare quality. Zoo type is a key factor in predicting signage and welfare quality, with accredited zoos scoring highest for both signage and welfare, followed by government and private zoos. Private zoos charged higher admission than other zoo types, and zoo size and proximity to urban centers did not influence signage or welfare scores. Overall, we conclude that in our study, signage usage and quality are inadequate, highlighting the importance of compliance with robust zoo standards to improve education and welfare within zoos to support global conservation goals. 相似文献
13.
三峡工程与江汉平原农业持续发展 总被引:2,自引:0,他引:2
三峡工程与江汉平原农业持续发展朱俊林(湖北大学生态学研究所,武汉430062)InfluencesoftheThree_GorgeProjectontheAgricultureinJianghanPlainAreaandtheA┐gricultura... 相似文献
14.
Diversification of Sulawesi macaque monkeys: decoupled evolution of mitochondrial and autosomal DNA 总被引:4,自引:0,他引:4
Evans BJ Supriatna J Andayani N Melnick DJ 《Evolution; international journal of organic evolution》2003,57(8):1931-1946
Abstract. In macaque monkeys, females are philopatric and males are obligate dispersers. This social system is expected to differently affect evolution of genetic elements depending on their mode of inheritance. Because of this, the geographic structure of molecular variation may differ considerably in mitochondrial DNA (mtDNA) and in autosomal DNA (aDNA) in the same individuals, even though these genomes are partially co-inherited. On the Indonesian island of Sulawesi, macaque monkeys underwent an explosive diversification as a result of range fragmentation. Today, barriers to dispersal have receded and fertile hybrid individuals can be found at contact zones between parapatric species. In this study, we examine the impact of range fragmentation on Sulawesi macaque mtDNA and aDNA by comparing evolution, phylogeography, and population subdivision of each genome. Our results suggest that mtDNA is paraphyletic in some species, and that mtDNA phylogeography is largely consistent with a pattern of isolation by distance. Autosomal DNA, however, is suggestive of fragmentation, in that interspecific differentiation across most contact zones is significant but intraspecific differentiation between contact zones is not. Furthermore, in mtDNA, most molecular variation is partitioned between populations within species but in aDNA most variation is partitioned within populations. That mtDNA has a different geographic structure than aDNA (and morphology) in these primates is a probable consequence of (1) a high level of ancestral polymorphism in mtDNA, (2) differences between patterns of ancestral dispersal of matrilines and contemporary dispersal of males, and (3) the fact that female philopatry impedes gene flow of macaque mtDNA. 相似文献
15.
Vietnam has the highest number of primate taxa overall (24-27) and the highest number of globally threatened primate taxa (minimum 20) in Mainland Southeast Asia. Conservation management of these species depends in part on resolving taxonomic uncertainties, which remain numerous among the Asian primates. Recent research on genetic, morphological, and acoustic diversity in Vietnam's primates has clarified some of these uncertainties, although a number of significant classification issues still remain. Herein, we summarize and compare the major current taxonomic classifications of Vietnam's primates, discuss recent advances in the context of these taxonomies, and suggest key areas for additional research to best inform conservation efforts in a region crucial to global primate diversity. Among the most important next steps for the conservation of Vietnam's primates is a new consensus list of Asian primates that resolves current differences between major taxonomies, incorporates recent research advances, and recognizes units of diversity at scales below the species-level, whether termed populations, morphs, or subspecies. Priority should be placed on recognizing distinct populations, regardless of the species concept in use, in order to foster the evolutionary processes necessary for primate populations to cope with inevitable environmental changes. The long-term conservation of Vietnam's primates depends not only on an accepted and accurate taxonomy but also on funding for on-the-ground conservation activities, including training, and the continued dedication and leadership of Vietnamese researchers and managers. 相似文献
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本文以东南亚园林中的两个常见元素—盆栽和方池为例,呈现了印度文明对东南亚园林的影响。在此基础上,通过案例呈现了东南亚园林的宗教和哲学内涵以及相应的常见造园手法。以此指出,东南亚园林不只是对中国、欧洲园林的模仿,其园林设计受印度影响较大,且有一以贯之的逻辑,并能够承载深刻的思想内涵 相似文献
18.
Helen J. Chatterjee 《International journal of primatology》2006,27(3):699-712
Phylogenetic relationships within Hylobatidae are controversial. Numerous studies based on molecular, morphological and behavioral characteristics have provided conflicting results. I reanalyzed published cytochrome b gene sequence data to provide a new estimate of gibbon phylogeny. My results indicate that Nomascus, Symphalangus and Hoolock are successively more closely related to Hylobates. Molecular clock analyses provide estimates of divergence times within Hylobatidae, indicating that the radiation dates to ca. 10.5 million years ago. Scientists have little understanding of the biogeographic history of gibbons, largely because of a sparse fossil record. I combined the estimate of gibbon phylogeny with distribution data in a dispersal-vicariance analysis and present a new scenario for the pattern and timing of gibbon radiation. 相似文献
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The American brackish-water mussel Mytella strigata is reported from Singapore for the first time. In 2016 a survey of intertidal hard structures in the Johor Straits revealed its almost ubiquitous presence in high mean densities, up to 124?±?32 individuals 25?cm?2 along the shoreline. Subtidal nets employed by floating fish farms were also fouled with this species. Densities exceeding 10,000 individuals 100?cm?2 were observed, to the exclusion of its relative Perna viridis, the Asian green mussel. Size-frequency analyses of shells indicated the presence of both juveniles and adults. Juveniles have an extremely variable shell surface pigmentation. The adults, reaching 5?cm in shell length, generally have a thick dark greenish brown to almost black periostracum, but bright green and olive green individuals, some with distinctive brown streaks, have also been observed. However, sequences of the mitochondrial COI gene were consistent with mussels from Brazil, Colombia and Ecuador, where they are natively distributed, while shells were reconcilable with type material. The species may have been transported in ballast water and/or with fouling directly from its native provinces, or spread from the Philippines where there are already established populations of M. strigata, possibly since the nineteenth century. 相似文献