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1.
A termite colony is usually founded by a pair of alates, the primary reproductives, which produce all the nestmates. In some species, secondary reproductives appear to either replace the primaries or supplement colony reproduction. In termites, secondary reproductives are generally ergatoids derived from workers or nymphoids derived from nymphs. Silvestritermes euamignathus is a termite species that forms multiple nymphoid reproductives, and to date it was hypothesized that these secondary reproductives were the progeny of the primary founding reproductives. We developed markers for 12 microsatellite loci and used COI mitochondrial DNA (mtDNA) to genotype 59 nymphoid neotenics found in a colony of S. euamignathus to test this hypothesis. Our results showed that nymphoids of S. euamignathus are not all siblings. The microsatellite analysis suggests that the secondary reproductives derived from a minimum of four different pairs of reproductives belonging to at least two different matrilines. This is the first record of non-sibling secondary reproductives occupying the same nest in a higher termite. These unrelated reproductives might be the result of either pleometrotic colony foundation or colony fusion. 相似文献
4.
This paper investigates the role of the science-policy interface in leveraging transitions to sustainable urban water management. The paper presents a case study of the Dutch city of Rotterdam, which is increasingly regarded as a global leader in adaptive and resilient urban water management. The analysis reveals that Rotterdam’s transition has occurred incrementally over the past 15 years, driven by policy entrepreneurs: largely municipal policy makers and policy practitioners. Strategic use of the science-policy interface (SPI) has facilitated the development of innovative solutions to achieve policy goals and created the enabling conditions necessary for transformative change. The Rotterdam case suggests that an effective SPI requires: (1) compelling water narrative; (2) cross-sectoral collaboration; (3) co-production of knowledge; (4) experiential evidence-based learning; (5) strategic use of trusted scientists; (6) fostering networks; and (7) generating business from science-based innovation. Rotterdam’s strategic approach to knowledge and innovation coupled with a new narrative around water sets it apart from many other cities and adds a new dimension to debates regarding enabling factors for advancing sustainable practices. These findings will be of interest to those engaged in urban water management policy and practice, environmental governance, and debates over transitions more broadly. 相似文献
6.
In most developing countries, at the household level, traditional burning of biomass or use of inefficient technologies for domestic applications like lighting is common, triggering concerns related to fuel or technology switching. The paper focuses on opportunities to promote cleaner energy options through development of value chains delivering improved energy efficiency and access in developing countries. We discuss the example of Uttam Urja, a field project involving the dissemination of photovoltaic lighting technologies in rural areas of India. We focus on the challenges of introducing radical innovations into the residential energy sector in developing countries. For the purpose of this paper the Uttam Urja project is conceptualized as an ‘experiment’ and analysed using the Strategic Niche Management (SNM) framework. The paper emphasizes that to effect socio-technical transitions to clean energy options on the ground, it is desirable to focus on technology customization and innovative financing to cater to the needs and concerns of end users. 相似文献
7.
The impacts of climate change are expected to be generally detrimental for agriculture in many parts of Africa. Overall, warming and drying may reduce crop yields by 10–20% to 2050, but there are places where losses are likely to be much more severe. Increasing frequencies of heat stress, drought and flooding events will result in yet further deleterious effects on crop and livestock productivity. There will be places in the coming decades where the livelihood strategies of rural people may need to change, to preserve food security and provide income-generating options. These are likely to include areas of Africa that are already marginal for crop production; as these become increasingly marginal, then livestock may provide an alternative to cropping. We carried out some analysis to identify areas in sub-Saharan Africa where such transitions might occur. For the currently cropped areas (which already include the highland areas where cropping intensity may increase in the future), we estimated probabilities of failed seasons for current climate conditions, and compared these with estimates obtained for future climate conditions in 2050, using downscaled climate model output for a higher and a lower greenhouse-gas emission scenario. Transition zones can be identified where the increased probabilities of failed seasons may induce shifts from cropping to increased dependence on livestock. These zones are characterised in terms of existing agricultural system, current livestock densities, and levels of poverty. The analysis provides further evidence that climate change impacts in the marginal cropping lands may be severe, where poverty rates are already high. Results also suggest that those likely to be more affected are already more poor, on average. We discuss the implications of these results in a research-for-development targeting context that is likely to see the poor disproportionately and negatively affected by climate change. 相似文献
8.
The Science of Nature - 相似文献
10.
Balanced reciprocal translocation is one of the known causes of recurrent spontaneous abortions. Cytogenetic studies of unbalanced miscarriages are difficult due to the growth failure of early loss and usually macerated abortions. We present a molecular study of an abortion in which the father carries a balanced reciprocal translocation t(2;17)(q32.1;q24.3) using QF-PCR and CGH techniques. DNA analysis showed the presence of a trisomy 2 due to a 3:1 interchange segregation. Recombinant events could also be investigated by comparing DNA samples from the family. We propose QF-PCR in addition to CGH as an efficient diagnostic method to improve our knowledge of unbalanced offspring in balanced translocation carriers. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
11.
"三合一"建筑场所的形成有一定历史背景,与我国经济社会发展有密不可分的联系,历次惨痛火灾教训,让人们对该类建筑场所危害性有了更为深刻的认识,面对严峻的火灾形势,短时间内根治"三合一"建筑场所火灾隐患显得极为困难。因此,如何应急解决现有"三合一"建筑场所火灾隐患,并从长远角度防止出现新的"三合一"建筑场所,是实现当前社会稳定、经济健康、稳定、和谐发展目标的重要课题。本文着力在分析"三合一"建筑场所成因、短期应急措施、长期有效管理,以及如何走出当前消防工作误区等方面提出了对策和意见。 相似文献
12.
Among 5315 prenatal diagnoses performed for various indications (maternal age, neural tube defect, metabolic diseases, X-linked diseases, pathologic pregnancies) 29 unexpected structural chromosome rearrangements were found in fetal cells. Fourteen were de novo chromosome rearrangements, six unbalanced, and eight balanced. Fifteen were inherited and balanced rearrangements. This high frequency of structural anomalies is discussed. 相似文献
13.
Transitions are radical system innovations that usually take 1–2 generations. Using Cultural Theory as a heuristic, this paper presents four archetypical approaches to transition management. The fatalist approach refrains from transition management (motto: ‘First, disaster must happen’). The system is in a stalemate that no experiment or hierarchy can break; external events must bring the window of opportunity for change. The hierarchic approach relies on a dominant actor coalition to steer change (motto: ‘Let's put a man on the moon!’). The individualist approach relies mainly on changing the financial ground rules (motto: ‘Sustainability through the market’). Finally, the egalitarian approach relies on process management, doing experiments, etc. (motto: ‘A good transition arena will solve it all’). This approach makes sense if the situation is not clear enough to be managed via one of the other approaches, and there is a clearly identifiable learning objective. 相似文献
14.
在充分分析活性污泥系统中生物反应机理的基础上,建立了活性污泥系统生物去除营养物质的细观机理模型--全耦合活性污泥模型(Fully Coupled Activated Sludge Model No.3,简称FCASM3).FCASM3将系统中微生物划分为8类菌群,包含31种组分、72个子过程;该模型的主要特点是将活性污泥系统中的微生物进一步细化,充分考虑了系统中微生物间的相互作用.FCASM3引入了硝化-反硝化过程中的中间产物亚硝酸盐.实现了对两步硝化-反硝化过程的模拟;FCASM3不仅包含聚糖菌的有关生物反应过程,而且还考虑了聚磷菌(非反硝化聚磷菌和反硝化聚磷菌)以及聚糖菌的厌氧维持过程,为直接体现温度对生物反应的影响,FCASM3将温度作为一个变量直接耦合到生物反应速率方程中. 相似文献
15.
Conversations with Manfred Eigen proved useful. 相似文献
16.
We report a case of pyruvate dehydrogenase E1 alpha subunit deficiency associated with a novel hemizygous PDHA1 variant presenting prenatally as multiple structural brain abnormalities in a male fetus. A healthy Finnish couple was initially referred to the Fetomaternal Medical Center because of suspected fetal choroid plexus cyst at 11 + 2 weeks of pregnancy. At 20 + 0 weeks, multiple abnormalities were observed with ultrasound including narrow thorax, slightly enlarged heart, hypoplastic cerebellum, absent cerebellar vermis and ventriculomegaly. Autopsy and genetic analyses were performed after the termination of pregnancy. The findings of macroscopic examination included cleft palate, abnormally overlapping position of fingers and toes and dysmorphic facial features. Neuropathological examination confirmed the absence of corpus callosum, cerebellar hypoplasia and ventriculomegaly. Nodular neuronal heterotopia was also observed. Trio exome sequencing revealed a novel hemizygous de novo variant c.1144C>T p.(Gln382*) in the PDHA1 gene, classified as likely pathogenic. We suggest that inherited metabolic disorders should be kept in mind as differential diagnoses in fetuses with structural brain abnormalities. 相似文献
19.
Shewanella sp. ANA-3 with the respiratory arsenate reductase (ArrAB) and MR-1 with ferric reduction ability always coexist in the presence of high arsenic (As)-containing waste residue. However, their synergistic impacts on As transformation and mobility remain unclear. To identify which bacterium, ANA-3 or MR-1, dominates As mobility in the coexisting environment, we explored the As biotransformation in the industrial waste residue in the presence of Shewanella sp. ANA-3 and MR-1. The incubation results show that As(III) was the main soluble species, and strain ANA-3 dominated As mobilization. The impact of ANA-3 was weakened by MR-1, probably due to the survival competition between these two bacteria. The results of micro X-ray fluorescence and X-ray photoelectron spectroscopy analyses further reveal the pathway for ANA-3 to enhance As mobility. Strain ANA-3 almost reduced 100% surface-bound Fe(III), and consequently led to As(V) release. The dissolved As(V) was then reduced to As(III) by ANA-3. The results of this study help to understand the fate of arsenic in the subsurface and highlight the importance of the safe disposal of high As-containing industrial waste. 相似文献
20.
An extra small chromosome detected in amniotic fluid was identified as the product of a translocation [46,XX,t(9;15)(p24;q11.2)]. This case is unusual in that individuals with the unbalanced karyotype resulting from a 3:1 disjunction are phenotypically normal. 相似文献
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