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361.
Alessandra Galiè 《Natural resources forum》2013,37(1):31-42
This paper presents the findings of a study on the governance of seed conducted in the framework of a participatory plant breeding (PPB) programme, based on a multi‐year inquiry with a panel of ten Syrian households. The study assessed the interactions between governance regimes regulating the rights to access and control genetic resources at international and national level, compared to the actual ability of the respondent women farmers to access and control the seed of varieties they co‐developed with the PPB programme. The paper argues that gender equal access to seed can “optimally” contribute to enhancing household food security in small scale farming. The paper also argues that to support a gender‐equal access to seed in the respondent households legislation needs to explicitly protect the rights of women farmers to access and share the benefits of genetic material and draw from empirical evidence of the actual access to and control of seed at ground level. 相似文献
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Dharmaratne Amarakoon Anthony Chen Sam Rawlins Dave D. Chadee Michael Taylor Roxann Stennett 《Mitigation and Adaptation Strategies for Global Change》2008,13(4):341-357
The seasonality, patterns and the climate associations of the reported cases of dengue in the Caribbean were studied by analyzing the annual and monthly variability of reported cases as well as those of climate parameters (temperature and precipitation). More attention was given to Trinidad and Tobago, Barbados, and Jamaica, as those countries contributed mostly to the reported cases. The data were for the period 1980–2003. Results showed that the incidence of dengue in the Caribbean were higher in the last decade (1990s) compared to that in the previous decade (1980s). The yearly patterns of dengue exhibited a well-defined seasonality. The epidemics appeared to occur in the later half of the year following onset of rainfall and increasing temperature. Analysis revealed that the association of the epidemics with temperature was stronger, especially in relation to the onset of dengue, and the probability of epidemics was high during El Niño periods. In years with early warmer periods epidemics appeared to occur early, which was a scenario more probable in the year after an El Niño (an El Niño + 1 year). Indices linked to temperatures that are useful for gauging the potential for onset of dengue were examined. An index based on a moving average temperature (MAT) appeared to be effective in gauging such potential and its average (AMAT) signals a threshold effect. MAT index has potential use in adaptation and mitigation strategies. 相似文献
364.
以大肠杆菌(E.coli)为模式生物,研究了磺胺类抗生素(SAs)和纳米银(AgNPs)在单一或联合作用下对RP4质粒接合转移效应及E.coli突变效应的影响,并对联合作用方式进行了判别,基于分子对接技术和线性回归分析,探讨了两种效应的机制及其与毒性效应的关系.结果表明,在较低浓度范围内,所测12种SAs以及AgNPs在单一或联合暴露下对接合转移和突变均有促进作用,12组SAs-AgNPs混合物对接合转移频率促进率峰值的最大值和最小值分别为105.32%和46.96%,对突变体促进率峰值的最大值和最小值分别为1410.25%和238.38%.此外,SAs和AgNPs联合暴露对RP4质粒接合转移效应主要表现为协同作用,对E.coli突变效应主要表现为拮抗作用,且接合转移效应、突变效应与毒性效应之间具有良好的相关性. 相似文献
365.
报道了盐碱地池塘、水库、湖泊养鱼中的水质改良技术。池塘水质改良措施主要为加注淡水、施用有机肥、注水与施肥相结合、改造盐碱土质、控制生石灰用量及合理注排水 ;水库、湖泊等大水面水质改良的主要措施是引淡水和增施肥料 (有机肥和化肥 )。 相似文献
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James S. Quinn Glen E. Woolfenden John W. Fitzpatrick Bradley N. White 《Behavioral ecology and sociobiology》1999,45(1):1-10
Extensive behavioural and pedigree data on a colour-marked population of Florida scrub-jays (Aphelocoma coerulescens) suggested that this cooperatively breeding species is monogamous, with extremely rare exceptions in which males have two
mates. We used multi-locus DNA fingerprinting to test these observations by determining genetic parentage. Despite restricted
dispersal and high relatedness between behavioural parents and non-breeding members of the group, DNA fingerprints provided
sufficient variability to determine parentage unambiguously in almost all cases. We found no evidence of extra-pair fertilisation
of females or egg dumping, and confirmed a suspected case of polygyny in which a mother and daughter laid and incubated in
the same nest. Our results confirm that detailed behavioural data allow accurate assignment of genetic parentage in this species.
In Florida scrub-jays, large territory size may limit opportunities for cuckoldry, and persistent intense competition for
limited breeding space may lead to low variance in the quality of established male breeders. These factors would reduce both
the opportunity for, and benefits of engaging in extra-pair fertilisations. Delayed dispersal and cooperative breeding in
this species have not evolved as avenues for direct reproduction by unpaired individuals.
Received: 25 May 1998 / Accepted after revision: 26 June 1998 相似文献
368.
微生物苯丙氨酸解氨酶(PAL)/肉桂酸途径生物转化制L-苯丙氨酸酶源菌种选育 总被引:4,自引:0,他引:4
L苯丙氨酸(Lphenylalanine,LPhe)是生化营养的必需氨基酸之一,作为临床医药用氨基酸输液、食品、饲料添加剂的必需成份和一些抗癌药物苯丙氨酸氮芥、甲酰溶肉瘤素等合成的中间体而得到广泛应用.自1965年天冬甜肽(Aspartame,APM,阿斯巴甜)发现并开发生产以来,这一新型甜味剂日渐风行,导致对高光学纯度LPhe这一主要构成原料需求量激增,人们纷纷开展LPhe的研制生产.在众多生物合成途径中,肉桂酸酶法转化生产LPhe的研究开发因其原料易得价廉,倍受国内外的许多公司和… 相似文献
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370.
当前,构建以渔民生态种养为主的生计转型长效机制,确保渔民“稳得住,能致富”是政府部门和学术界共同关注的重点。本文基于“生计恢复力”理论构建了“缓冲—自组织—学习”三维分析框架,借助必要条件分析(NCA)和模糊集定性比较分析(fsQCA)两种分析方法,从组态视角对长江退捕渔民生态种养采纳意愿的关键驱动条件、作用路径和潜在替代关系进行研究。研究发现:①NCA与QCA分析结果显示,单一条件无法形成渔民生态种养采纳意愿程度高的必要条件,但fsQCA组态分析显示,自组织能力尤其是对奖补惠及和政策新闻的关注能单独引致解释结果的产生。②渔民生态种养采纳意愿存在三种驱动路径,分别是自组织主导型、自组织—学习驱动型和缓冲—学习驱动型。同时,渔民生态种养采纳意愿存在三种抑制类型,分别是学习抑制型、自组织—学习抑制型及缓冲—自组织抑制型。 ③ 在特定条件下,自组织能力可以与其他两种能力的条件组合等效替代,以“殊途同归”的方式提升渔民生态种养采纳意愿。 相似文献