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991.
Bhavana Rao Kuchimanchi Imke J. M. De Boer Raimon Ripoll-Bosch Simon J. Oosting 《Ambio》2021,50(10):1809
Increasing food demands are causing rapid transitions in farming systems, often involving intensified land and resource use. While transitioning has benefits regarding poverty alleviation and food outputs, it also causes environmental and social issues over time. This study aims to understand the transitions in farming systems in a region in Telangana, from 1997 to 2015, and their effect on livestock rearing and smallholder livelihoods. We also examine the impact of the transitions on lower caste groups and women in particular. We collected data using a combination of methods, i.e., a household survey, focus group discussions, and secondary data sources, to build a comprehensive picture of the transitions in the region. We found that subsistence mixed farming systems transitioned to market-orientated specialized systems over a short time span. As the transition process gained momentum, households either intensified their production or got marginalized. Technological interventions, development programs with integrated approaches, and market demand for certain agricultural produce triggered increased regional production but also led to the scarcity of water, land, and labor. The transitions marginalized some of the households, changed the role of livestock in farming, and have been inclusive of both lower caste groups and women in terms of increased ownership of large ruminants and access to technologies. However, for women specifically, further increase in workload in the context of farming is also found. 相似文献
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Wouter T. De Groot Haranath Tadepally 《Environment, Development and Sustainability》2008,10(4):519-536
In southern India, tens of thousands of village-level irrigation systems (‘tanks’ and feeder channels) are in disrepair. This
paper analyses the results of a local NGO effort that focused on awareness-raising and advice to bring about self-sustained
community action for irrigation system restoration. After designing a model structure that contains both motivational and
capacity (social capital) factors, it is found that (pre-existing) collective social capital, as measured through five simple
indicators, strongly correlates with success of the NGO strategy. The intensity of the NGO’s effort shows a negative correlation
with success, however. The discussion focuses on issues of social capital definition and measurement and the practical implications
of the concept for environmental action, especially the difference between using existing social capital for environmental
management versus the construction of social capital as a basis for later self-sustained environmental work.
Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
995.
Gloria Antonini Paolo Audisio Emiliano Mancini Alessio De Biase Carlo Tronci Giulia Rossetti Marco Trizzino 《Marine Biology》2010,157(2):371-381
Marine rock-pools, commonly found along the Mediterranean coasts, are isolated patches of habitat characterised by large spatial
and temporal variations. The phylogeography of Calobius quadricollis and C. urbanelliae, two sibling species of moss beetles (Coleoptera, Hydraenidae) inhabiting Italian temporary marine rock-pool ecosystems,
were studied using mitochondrial cytochrome c oxidase subunit I (COI). Our data suggest a strong association between the scored
genetic variability and the geographical distribution of populations sampled for both species. These analyses provided evidences
of episodic species range expansion and fragmentation, recurrent “flush and crash” and bottleneck episodes probably occurring
during the Glacial Cycles. The observed phylogeographical pattern is probably related to the historical and biogeographical
processes of Mediterranean areas, as well as both to the ephemeral habitat tipology and limited dispersal ability of these
beetles. 相似文献
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Today, preimplantation genetic diagnosis (PGD) is offered in over 40 centres worldwide for an expanded range of genetic defects causing disease. This very early form of prenatal diagnosis involves the detection of affected embryos by fluorescent in situ hybridization (FISH) (sex determination or chromosomal defects) or by polymerase chain reaction (PCR) (monogenic diseases) prior to implantation. Genetic analysis of the embryos involves the removal of some cellular mass from the embryos (one or two blastomeres at cleavage-stage or some extra-embryonic trophectoderm cells at the blastocyst stage) by means of an embryo biopsy procedure. Genetic analysis can also be performed preconceptionally by removal of the first polar body. However, additional information is then often gained by removal of the second polar body and/or a blastomere from the embryo. Removal of polar bodies or cellular material from embryos requires an opening in the zona pellucida, which can be created in a mechanical way (partial zona dissection) or chemical way (acidic Tyrode's solution). However, the more recent introduction of laser technology has facilitated this step enormously. Different biopsy procedures at different preimplantation stages are reviewed here, including their pros and cons and their clinical applications. The following aspects will also be discussed: safety of zona drilling by laser, use of Ca2+/Mg2+-free medium for decompaction, and removal of one or two cells from cleavage-stage embryos. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
998.
Michael S. Tomlinson Eric H. De Carlo 《Journal of the American Water Resources Association》2003,39(1):113-123
ABSTRACT: Streams in the Hawaiian Islands differ from many streams on the U.S. mainland presenting unique challenges to investigators attempting to characterize Hawaiian streams. Hawaiian streams are short; watersheds are small and steep; and rain events are usually short in duration but intense. As a result, most streams in Hawai'i are flashy. Time scales for storm hydrographs in Hawai'i are on the order of hours instead of days and flash flooding is a common hazard. To characterize the streams we were investigating, we found it necessary to obtain streamflow and water quality measurements at relatively short time intervals. While this resolution resulted in large sometimes onerous quantities of data, we would have otherwise missed certain phenomena, such as 60‐fold flow changes in 15 minutes or 30‐fold turbidity changes in five minutes. Even at five‐minute intervals, we found that attempts to predict TSS using a relationship obtained from in situ turbidity were not always satisfactory. Depending on the precision required, either higher resolution measurements or in vitro turbidity measurements of the TSS samples might be necessary. Finally, these high resolution measurements enabled us to observe other cyclical events that might have been missed if the measurement intervals were greater than one hour. 相似文献
999.
Gilbert Decat Leo Deckx Guy Meynen Emmy De Graef Florence Jonlet 《International journal of occupational safety and ergonomics》2006,12(2):169-176
The spectrum and the polarization of the magnetic flux density (B-field) of 6 induction heaters and 1 arc oven were measured by means of a PMM (Italy) spectrum analyser. The spectrum analysis showed that no substantial harmonics were observed while the polarization analysis revealed that the operator's exposure was non-homogeneous within a distance of 1.5 m from the heater. When the distance was larger, the body was homogeneously exposed. In general we can state that the B-field strongly varied between heaters and that exposure exceeded the occupational reference levels recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) (1998) and European Directive 2004/40/EC in 5 of the 7 heaters. Within the framework of the Directive some protection actions should be taken. Whereas mitigation of existing/old induction ovens is difficult, the design of new induction heaters and their housing should be based, among others, on electromagnetic reducing engineering concepts. 相似文献
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