Gender and property rights in the commons: Examples of water rights in South Asia     

Margreet Zwarteveen  Ruth Meinzen-Dick 《Agriculture and Human Values》2001,18(1):11-25

In many countries and resource sectors, the state is devolving responsibility for natural resource management responsibility to ``communities' or local user groups. However, both policymakers and researchers in this area have tended to ignore the implications of gender and other forms of intra-community power differences for the effectiveness and equity of natural resource management. In the irrigation sector, despite the rhetoric on women's participation, a review of evidence from South Asia shows that organizations often exclude women through formal or informal membership rules and practices. Women may have other ways to obtain irrigation services, but even if they are effective, these other informal ways of obtaining irrigation services are typically less secure. As resource management – and rights to resources – are transferred from the state to local organizations, ensuring women's participation is essential for gender equity in control over resources. Greater involvement of women can also strengthen the effectiveness of local organizations by improving women's compliance with rules and maintenance contributions. Further detailed and comparative research is required to identify the major factors that affect women's participation and control over resources, if devolution policies are to be both equitable and sustainable. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

Host-bacterial mutualism in the human intestine   总被引：2，自引：0，他引：2  

Bäckhed F  Ley RE  Sonnenburg JL  Peterson DA  Gordon JI 《Science (New York, N.Y.)》2005,307(5717):1915-1920

The distal human intestine represents an anaerobic bioreactor programmed with an enormous population of bacteria, dominated by relatively few divisions that are highly diverse at the strain/subspecies level. This microbiota and its collective genomes (microbiome) provide us with genetic and metabolic attributes we have not been required to evolve on our own, including the ability to harvest otherwise inaccessible nutrients. New studies are revealing how the gut microbiota has coevolved with us and how it manipulates and complements our biology in ways that are mutually beneficial. We are also starting to understand how certain keystone members of the microbiota operate to maintain the stability and functional adaptability of this microbial organ.  相似文献   

Gendered participation in water management: Issues and illustrations from water users‘ associations in South Asia     

Ruth Meinzen-Dick  Margreet Zwarteveen 《Agriculture and Human Values》1998,15(4):337-345

The widespread trend to transferirrigation management responsibility from the stateto communities or local user groups has byand large ignored the implications ofintra-community power differences for theeffectiveness and equity of water management. Genderis a recurrent source of such differences. Despitethe rhetoric on womens participation, a review ofevidence from South Asia shows that femaleparticipation is minimal in water usersorganizations. One reason for this is that theformal and informal membership criteria excludewomen. Moreover, the balance between costs andbenefits of participation is often negative forwomen because complying with the rules and practicesof the organization involves considerable time costsand social risks, whereas other ways to obtainirrigation services may be more effective for femalewater users. Although effective, these other andoften informal ways of obtaining irrigation servicesare also typically less secure. More formalparticipation of women can strengthen womensbargaining position as resource users withinhouseholds and communities. Greater involvement ofwomen can also strengthen the effectiveness of theorganization by improving womens compliance withrules and maintenance contributions. Furtherdetailed and comparative research is required toidentify the major factors that affect womensparticipation and control over resources, ifdevolution policies are to address the tensionbetween objectives of transferring control overresources to community institutions, and ensuringthe participation of all members of the community,especially women.  相似文献   

Regulation of bone mass in mice by the lipoxygenase gene Alox15     

Klein RF  Allard J  Avnur Z  Nikolcheva T  Rotstein D  Carlos AS  Shea M  Waters RV  Belknap JK  Peltz G  Orwoll ES 《Science (New York, N.Y.)》2004,303(5655):229-232

The development of osteoporosis involves the interaction of multiple environmental and genetic factors. Through combined genetic and genomic approaches, we identified the lipoxygenase gene Alox15 as a negative regulator of peak bone mineral density in mice. Crossbreeding experiments with Alox15 knockout mice confirmed that 12/15-lipoxygenase plays a role in skeletal development. Pharmacologic inhibitors of this enzyme improved bone density and strength in two rodent models of osteoporosis. These results suggest that drugs targeting the 12/15-lipoxygenase pathway merit investigation as a therapy for osteoporosis.  相似文献   

Primary structure of the beta subunit of the DHP-sensitive calcium channel from skeletal muscle   总被引：18，自引：0，他引：18  

P Ruth  A R?hrkasten  M Biel  E Bosse  S Regulla  H E Meyer  V Flockerzi  F Hofmann 《Science (New York, N.Y.)》1989,245(4922):1115-1118

Complementary DNAs for the beta subunit of the dihydropyridine-sensitive calcium channel of rabbit skeletal muscle were isolated on the basis of peptide sequences derived from the purified protein. The deduced primary structure is without homology to other known protein sequences and is consistent with the beta subunit being a peripheral membrane protein associated with the cytoplasmic aspect of the sarcolemma. The protein contains sites that might be expected to be preferentially phosphorylated by protein kinase C and guanosine 3',5'-monophosphate-dependent protein kinase. A messenger RNA for this protein appears to be expressed in brain.  相似文献   

Germ versus soma decisions: lessons from flies and worms     

Strome S  Lehmann R 《Science (New York, N.Y.)》2007,316(5823):392-393

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Embryonic stem cells. Willingness to donate frozen embryos for stem cell research     

Lyerly AD  Faden RR 《Science (New York, N.Y.)》2007,317(5834):46-47

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Issues in biosecurity and biosafety     

Cook-Deegan RM  Berkelman R  Davidson EM  Finder S  Heitman E  Kelley MC  King NM  Moseley R  Thomas JC  Tilden SJ  Vangsnes NM 《Science (New York, N.Y.)》2005,308(5730):1867-1868

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Harvest regimen optimization and essential oil production in five tansy (Tanacetum vulgare L.) genotypes under a northern climate     

Dragland S  Rohloff J  Mordal R  Iversen TH 《Journal of agricultural and food chemistry》2005,53(12):4946-4953

Tansy (Tanacetum vulgare L.) was cultivated at the Norwegian Crop Research Institute at the Apelsvoll Research Centre, Division Kise, in the period from 2000 to 2001. The study focused on different harvesting regimens for high biomass production and essential oil (EO) yield and quality. Two tansy genotypes from Canada (Richters and Goldsticks) and three Norwegian genotypes (Steinvikholmen, Alvdal, and Brumunddal) were studied. The Canadian genotypes reached a height of 130-145 cm and showed a higher dry weight of aerial plant parts compared to the Norwegian plants in 2000. Similar oil yields could be observed for the Canadian types and genotype Steinvikholmen in the range of 30.8-34.6 L/ha when the plants were harvested twice during budding and before flowering after regrowth (year 2001). In contrast, single harvesting at the full bloom stage resulted in higher oil yields, between 42.1 and 44.5 L/ha (Canadian genotypes), whereas 21.0-38.4 L/ha was obtained from the Norwegian types. Tansy genotypes could be grouped into the following chemotypes: the mixed chemotypes Steinvikholmen (thujone-camphor), Alvdal (thujone-camphor-borneol), Goldsticks (thujone-camphor-chrysanthenyl type), and Brumunddal (thujone-camphor-1,8-cineole-bornyl acetate/borneol-alpha-terpineol) and the distinct chemotype Richters, with average concentrations of (E)-chrysanthenyl acetate >40% in both leaf and flower EO.  相似文献   

The influence of gel strength on aroma release from pectin gels in a model mouth and in vivo, monitored with proton-transfer-reaction mass spectrometry     

Hansson A  Giannouli P  van Ruth S 《Journal of agricultural and food chemistry》2003,51(16):4732-4740

The course of events from taking a food into the mouth to the perception of the food's flavor involves many steps, from dilution with saliva, mastication, and transportation of the compounds to the olfactory epithelium to transformation into signals that go to the brain. In addition, there are also the effects of the food's structure and properties. In this study, a proton-transfer-reaction mass spectrometer (PTR-MS) was used to investigate how four pectin-containing systems with different structures and strengths affected the release of aroma compounds in a model mouth and in the nose of an assessor. Both the model mouth and the in-nose measurements showed that the strength and structure of pectin-containing systems are important with regard to the quantity of aroma compounds that are released. Mastication and saliva were also shown to have a large influence on how much of the aroma compound is released from the mouth to the nose.  相似文献