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991.
Goal, Scope and Background The objective of this study was to assess environmental impacts of Norwegian cod fishing and salmon farming and compare these with chicken farming in order to find reference levels for environmental performance and identify problem areas and potentials for improvements. Methods A Life Cycle Screening following the production of 0.2 kg fillets as a functional unit through the respective food chains is performed for all 3 products. The analysis is partly quantitative and qualitative focusing on energy use, antifouling and land use impacts. Case studies are performed to investigate potentials for improvements within the fisheries and aquaculture industry. Results and Conclusions It can be concluded that the fishing phase for the cod and the feeding phase for both salmon and chicken dominate for all environmental impacts considered. Chicken is most energy effective followed by salmon and cod, which are almost on the same level. The area of sea floor affected by bottom trawling is around 100 times larger than the land area needed to produce the chicken feed for production of the 0.2 kg fillet. - The case studies show potentials for improvement of environmental performance, both for salmon farming and cod fishing, especially when it comes to energy use. The environmental impacts on the sea floor imposed by bottom trawling are not fully explored, but based on the precautionary principle a reasonable conclusion is that bottom trawls with less impact on the sea floor should be developed. Recommendation and Perspective LCA methods have initially been developed for land based industrial applications. More effort should be given to adapt these to fishing applications in order to obtain more accurate assessment of environmental impacts from seafood products. It is recommended to put more emphasis in finding improved indicators for impacts imposed by over-fishing, fuel emission from combustion at sea, use of antifouling and seafloor ecosystem disturbance.  相似文献   
992.
Paecilomyces lilacinus and in particular the commercial strain 251 has been intensively tested for biological control of plant parasitic nematodes. Since this species has been mentioned in a number of reports concerning infection of humans, the human health risk for Paecilomyces lilacinus strain 251 was investigated. The effects of time, temperature and growth medium on radial colony growth and germination were determined. Additionally, exposure to 36°C and its effect on germ-tube extension and on survival of conidia was evaluated. Radial growth was significantly affected by temperature, growth medium and their interaction. Optimum temperatures were between 24 and 30°C, but no growth was found at 36°C. Germination rate was significantly influenced by time, medium, temperature and their interactions. The optimum temperature range for germination was between 28 and 30°C. Formulated conidia were capable of germinating at 36°C. However, studies on germ-tube extension conducted at 36°C showed a delay in development for 28-49 h and no further germ-tube extension was found after exposure for 80-95 h. Slopes of survival curves were significantly influenced by the type of conidia tested. In general, conidia did not survive exposure to 36°C for 168 h. These experiments indicate the temperature conditions where the strain is likely to be active and provide supporting data for full environmental and health risk assessments of biocontrol fungi.  相似文献   
993.
The comprehensive knowledge that the delayed systemic and reproduction side effects can be even more deleterious than acute toxicity, has caused a shift in focus toward sublethal effects assessment on physiology and behavior of beneficial insects. In this study, we assessed the risks posed by some insecticides with different mode of action through lethal and delayed systemic sublethal effects on the pupation, adult emergence, and reproduction of the chrysopid Chrysoperla externa (Hagen, 1861; Neuroptera: Chrysopidae), an important predator in pest biological control. The maximum field recommended dose (MFRD) and twice (2×MFRD) for chlorantraniliprole, tebufenozide, and pyriproxyfen were harmless to C. externa. In contrast, all the tested chitin synthesis inhibitors (CSIs) were highly detrimental to the predator, despite of their lack of acute lethal toxicity. Therefore, the safety assumed by using IGRs toward beneficial insects is not valid for chrysopids. Dose–response data showed that although all CSIs have a similar mechanism of action, the relative extent of toxicity may differ (novaluron > lufenuron > teflubenzuron). For CSIs, the delayed systemic effects became obvious at adult emergence, where the predicted no observable effect dose (NOED) was 1/2 048 of the MFRD for novaluron (0.085 ng/insect), and 1/256 of the MFRD for both lufenuron (0.25 ng/insect) and teflubenzuron (0.6 ng/insect). Finally, this work emphasized the significance of performing toxicity risk assessments with an adequate posttreatment period to avoid underestimating the toxicities of insecticides, as the acute lethal toxicity assays may not provide accurate information regarding the long‐range effects of hazardous compounds.  相似文献   
994.
统计了分布在西藏自治区的被子植物及各生活型果实的类型及比例,并与藏东南地区做了比较。结果如下,西藏自治区果实以蒴果为主(占37.74%),其次为瘦果、坚果、浆果等;干果的比例远远大于肉果;不同生活型的果实类型谱差异较大,乔木中核果的比例最高,藤本中浆果比例最高,灌木中瘦果比例最高,草本中蒴果占优势;4个生活型中,肉果的比例乔木为最高,其次为藤本、灌木、草本。藏东南地区植物的果实类型也以蒴果为主,其次为瘦果、浆果、核果等;藏东南乔木中核果比例最高,藤本中浆果比例最高,灌木和草本植物以蒴果占优势;乔木肉果的比例最高,其次为藤本、灌木、草本。藏东南肉果比例大于全藏区,而干果比例则相反。果实类型的这些性状特征与各自的环境相适应,是植物长期适应自然环境的进化结果,该研究对于理解植物果实对生态环境的长期适应进化具有一定的意义。  相似文献   
995.
目的:肿瘤细胞的增殖和发展与多种细胞周期调控因子的异常密切相关,Skp-2通过泛素化降解p27,使肿瘤细胞G1-S期调控发生紊乱,从而参与肿瘤细胞的某些生物学性状,本实验探讨牙龈癌发生发展过程中Skp2蛋白的表达以及其与牙龈癌临床病理学之间的意义.方法:收集同期46例牙龈癌及22例正常牙龈组织标本,制备组织切片,应用SP免疫组化法检测正常黏膜及牙龈癌中Skp2蛋白的表达,以及Skp2蛋白在牙龈癌不同病理分级和临床分期中的表达.结果:Skp2蛋白在正常口腔粘膜组织与牙龈癌中的阳性表达率差异有统计学意义,Skp2蛋白在牙龈癌中的阳性率(32.61%,显著高于正常黏膜组织4.55 %)(x2=6.51P<0.05).应用阳性表达率表示Skp2与牙龈癌的临床分期、病理分级、性别、年龄之间的关系,结果显示Skp2与牙龈癌的临床分期及病理分级显著相关成正比例关系,差异具有统计学意义(P<0.05),而与年龄、性别等因素不相关,无统计学差异(P>0.05).结论:Skp2蛋白在口腔牙龈癌的临床分级和病理分级成正比例相关,与年龄、性别无显著相关,Skp2可能在牙龈癌的发生发展中起着重要的正向调控作用,检测Skp2有助于判断牙龈癌的恶性程度及其预后,为临床判断病变程度及治疗提供更加合理的方案.  相似文献   
996.
Mothers vary in duration of breastfeeding. These individual differences are related to a variety of demographic and individual maternal factors including maternal hormones, mood and early experiences. However, little is known about the role of genetic factors. We studied single‐nucleotide polymorphisms (SNPs) in the OXT peptide gene (rs2740210; rs4813627) and the OXT receptor gene (OXTR rs237885) in two samples of mothers from the Maternal adversity, Vulnerability and Neurodevelopment study (MAVAN), a multicenter (Hamilton and Montreal, Canada) study following mothers and their children from pregnancy until 7 years of age. Data from the Hamilton site was the primary sample (n = 201) and data from Montreal was the replication sample (n = 151). Breastfeeding duration, maternal mood (measured by the CES‐D scale) and early life adversity (measured by the CTQ scale) were established during 12 months postpartum. In our primary sample, polymorphisms in OXT rs2740210, but not the other SNPs, interacted with early life adversity to predict variation in breastfeeding duration (overall F8,125 = 2.361, P = 0.021; interaction effect b = ?8.12, t = ?2.3, P = 0.023) and depression (overall F8,118 = 5.751, P ≤ 0.001; interaction effect b = 6.06, t = 3.13, P = 0.002). A moderated mediation model showed that higher levels of depression mediated the inverse relation of high levels of early life adversity to breastfeeding duration, but only in women possessing the CC genotype [effect a′ = ?3.3401, 95% confidence interval (CI) = ?7.9466 to ?0.0015] of the OXT SNP and not in women with the AA/AC genotype (a′ = ?1.2942, ns). The latter findings (moderated mediation model) were replicated in our Montreal sample (a′ = ?0.277, 95% CI = ?0.7987 to ?0.0348 for CC; a′ = ?0.1820, ns for AA/AC) .  相似文献   
997.
The low activity variant of the monoamine oxidase A (MAOA) functional promoter polymorphism, MAOA‐LPR, in interaction with adverse environments (G × E) is associated with child and adult antisocial behaviour disorders. MAOA is expressed during foetal development so in utero G × E may influence early neurodevelopment. We tested the hypothesis that MAOA G × E during pregnancy predicts infant negative emotionality soon after birth. In an epidemiological longitudinal study starting in pregnancy, using a two stage stratified design, we ascertained MAOA‐LPR status (low vs. high activity variants) from the saliva of 209 infants (104 boys and 105 girls), and examined predictions to observed infant negative emotionality at 5 weeks post‐partum from life events during pregnancy. In analyses weighted to provide estimates for the general population, and including possible confounders for life events, there was an MAOA status by life events interaction (P = 0.017). There was also an interaction between MAOA status and neighbourhood deprivation (P = 0.028). Both interactions arose from a greater effect of increasing life events on negative emotionality in the MAOA‐LPR low activity, compared with MAOA‐LPR high activity infants. The study provides the first evidence of moderation by MAOA‐LPR of the effect of the social environment in pregnancy on negative emotionality in infancy, an early risk for the development of child and adult antisocial behaviour disorders .  相似文献   
998.
SUMMARY

This paper assesses the research undertaken at Lake St. Lucia over the past 25 years based on over 300 documents from that period. Trends related to both time and subject matter are evident, and these are considered in relation to the gaps in our current knowledge concerning the system.

A feature evident throughout the period under consideration is that the major portion of documented material available relates to reports and contributions to workshops (77%) with only 23% from scientific publications. Contributions by these two sources to the subject group being considered for St. Lucia are markedly different with research publications dominating the biological field and reports dominating in physical aspects, catchment characteristics, man's activities, management, dredging and hydrological modelling. However, some 55% of all unpublished data related to reviews or assessments of the state of research on St. Lucia.

The importance of the scientific publications group as an indicator of the state of research into the system is considered in the light of an apparent decline in the number of completed projects being published. It is also considered in the light of the recent establishment of a co-ordinated Lake St. Lucia Research Programme, which may provide the impetus for a more concentrated and directed research effort on the Lake System.  相似文献   
999.
Summary

Two and a half years of data were collected from the lower Great Fish River, head region and estuary to determine the fish species composition within these areas. Gilchristella aestuaria, Liza dumerilii, Rhabdosargus holubi and Pomadasys commersonnii were the four most abundant species captured, with riverine flow rate having an important effect on both species composition and numbers of fishes in the different regions. Most marine species displayed a strong inverse relationship between catch per unit effort and elevated freshwater inputs. Euryhaline marine species dominated the catches at all sampling sites during low flows but were less common during high flow periods when catadromous species were most abundant. Based on the available evidence it is suggested that for most marine species in the river this decline in abundance is related to low conductivity levels following floods rather than avoidance of elevated flows. The impact of elevated suspensoid concentrations and lowered dissolved oxygen concentrations on freshwater and estuarine fish populations during major river flooding is also discussed.  相似文献   
1000.
Moshe Szyf 《遗传学报》2013,40(7):331-338
The impact of early physical and social environments on life-long phenotypes is well known. Moreover, we have documented evidence for gene–environment interactions where identical gene variants are associated with different phenotypes that are dependent on early life adversity. What are the mechanisms that embed these early life experiences in the genome? DNA methylation is an enzymatically-catalyzed modification of DNA that serves as a mechanism by which similar sequences acquire cell type identity during cellular differentiation and embryogenesis in the same individual. The hypothesis that will be discussed here proposes that the same mechanism confers environmental-exposure specific identity upon DNA providing a mechanism for embedding environmental experiences in the genome, thus affecting long-term phenotypes. Particularly important is the environment early in life including both the prenatal and postnatal social environments.  相似文献   
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