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31.
Foraging behaviour of Armillaria rhizomorph systems   总被引:1,自引:0,他引:1  
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Cancer appears to be inversely associated with both Alzheimer''s and Parkinson''s disease. The relationship between cancer and sporadic motor neuron disease (SMND), however, remains uncertain. Most previous cancer-SMND studies have been undertaken in northern hemisphere populations. We therefore undertook a case-control study to see if a link between cancer and SMND exists in an Australian population. A questionnaire was used to compare past cancer diagnoses in 739 SMND patients and 622 controls, recruited across Australia. Odds ratios with 95% confidence intervals were calculated to look for associations between cancer and SMND. A history of cancer was not associated either positively or negatively with a risk of subsequent SMND. This result remained when age, gender, smoking status, and the four SMND diagnostic subgroups were taken into account. No association was observed between SMND and specific tumours, including melanoma, a common malignancy in Australia. In conclusion, this Australian case-control study does not support an association between a past history of cancer and the development of SMND. This suggests that some pathogenetic mechanisms, such as apoptosis, are less relevant in SMND than in other neurodegenerative diseases where negative associations with cancer have been found.  相似文献   
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Solar energy, fodder energy, microclimate optimization energy as well as technological process energy were defined as energy flows entering an egg production ecotechnical system. Nutrition biomass, chemical bond energy (eggs) and dung energy were estimated. Two criteria for energy consumption assessment were introduced: energy (kJ) consumed per unit of product and energy (kJ) consumed per unit of energy. Five fowl breeds were investigated. Restructuring in poultry farming was viewed with respect to the introduction of high performance breeds with low values of energy consumption. Elimination of systematic stress (abrupt transition of light intensity) reduced energy consumption in egg production. Methane fermentation parameters were optimized experimentally under laboratory conditions using a mathematical model. Dung biogas introduced an average of 25.75–29.52 MJ per bird into the observed system.  相似文献   
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We have applied the CRISPR/Cas9 system in vivo to disrupt gene expression in neural stem cells in the developing mammalian brain. Two days after in utero electroporation of a single plasmid encoding Cas9 and an appropriate guide RNA (gRNA) into the embryonic neocortex of Tis21::GFP knock‐in mice, expression of GFP, which occurs specifically in neural stem cells committed to neurogenesis, was found to be nearly completely (≈90%) abolished in the progeny of the targeted cells. Importantly, upon in utero electroporation directly of recombinant Cas9/gRNA complex, near‐maximal efficiency of disruption of GFP expression was achieved already after 24 h. Furthermore, by using microinjection of the Cas9 protein/gRNA complex into neural stem cells in organotypic slice culture, we obtained disruption of GFP expression within a single cell cycle. Finally, we used either Cas9 plasmid in utero electroporation or Cas9 protein complex microinjection to disrupt the expression of Eomes/Tbr2, a gene fundamental for neocortical neurogenesis. This resulted in a reduction in basal progenitors and an increase in neuronal differentiation. Thus, the present in vivo application of the CRISPR/Cas9 system in neural stem cells provides a rapid, efficient and enduring disruption of expression of specific genes to dissect their role in mammalian brain development.  相似文献   
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We used a simulation model of forest dynamics to examine the ecological significance of the complex interactions among site conditions, tree growth, and the development of a thick forest floor moss layer found in many boreal forests. To examine the effect of site conditions on moss growth and forest dynamics, we simulated the dynamics of several different forest sites in the uplands of interior Alaska. Then we used a cold, wet permafrost site to examine the ecological consequences of direct moss and tree interactions. Our analyses revealed a tightly coupled system in which forest succession was highly sensitive to the interactions among site conditions, mosses, and trees. The effect of mosses on the soil thermal regime was a particularly important feedback. Direct interactions between mosses and trees that affected the development of a thick forest floor layer were also important. In particular, shading of moss by trees, reduced tree regeneration on moss-covered soils, and reduced moss growth with open forest canopies were also important determinants of forest succession. These complex feedbacks ensure that an ecosystem approach is needed to understand the ecology of boreal forests.  相似文献   
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The paper presents data on the populational laterality proportions among men and women. Analysis of cardiac rhythm variations in right- and left-handed men and women in rest and during mental loading has shown a more pronounced sympathetic domination in left-handed examinees unlike right-handers. The most significant differences in the autonomic balance during mental loading were revealed between the left-handed and right-handed men. An earlier physiological maturation was established to be more characteristic of left-handed women as compared with right-handers. On the background of low and high levels of estrogens a correlation was revealed between the level of hormones and parameters of autonomic balance of the autonomic nervous system both in right-handed and left-handed women.  相似文献   
40.
Interstitial Cajal-like cells in human gallbladder   总被引:6,自引:0,他引:6  
We describe here an interstitial Cajal-like cell type (ICLC) in human gallbladder, resembling the archetypal enteric interstitial cells of Cajal. Gallbladder ICLC were demonstrated in fresh preparations (tissue cryosections) using methylene-blue, and fixed specimens in Epon semi-thin sections stained with toluidine blue or transmission electron microscopy (TEM). The positive diagnosis of gallbladder ICLC was further verified by immunohistochemistry: CD117/c-kit, CD34, and another 16 antigens: vimentin, desmin, nestin, α-smooth muscle actin, NK-1, S-100, PGP-9.5, tau protein, chromogranin A, NSE, GFAP, CD1a, CD62-P, CD68, estrogen and progesterone receptors. Double immunostaining was performed for CD117, CD34 and CD117 and nestin, respectively. In fresh specimens, the spatial density of gallbladder ICLC was 100–110 cells/mm2. ICLC mainly appeared beneath the epithelium and in muscularis (about 7%, and ∼5%, respectively). In toto, ICLC represent in gallbladder ∼5.5% of subepithelial cells. TEM showed that diagnostic criteria were fulfilled by ICLC. Moreover, TEM indicated that the main ultrastructural distinctive feature for ICLC, the cell processes, develop into the characteristic shape at a relatively early stage of development. It remains to be established if, in humans, ICLC are involved in gallbladder (dis)functions (e.g. pace-making, secretion (auto-, juxta- and/or paracrine), intercellular signaling, or stone formation). M. E. Hinescu and C. Ardeleanu contributed equally to this study.  相似文献   
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