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1.
Linkages between Human and Environmental Risk Assessment (HERA) and Life-Cycle Assessment (LCA) can be analyzed at three levels: the basic equations to describe environmental behavior and dose-response relationships of chemicals; the overall model structure of these tools; and the applications of the tools. At level 1 few differences exist: both tools use essentially the same fate and effect models, including their coefficients and data. At level 2 distinctive differences emerge: regional or life-cycle perspective, emission pulses or fluxes, scope of chemicals and types of impacts, use of characterization factors, spatial and temporal detail, aggregation of effects, and the functional unit as basis of the assessment. Although the two tools typically differ in all these aspects, only the functional unit issue renders the tools fundamentally different, expressing itself also in some main characteristics of the modeling structure. This impedes full integration, which is underpinned in mathematical terms. At level 3 the aims of the tools are complementary: quantified risk estimates of chemicals for HERA versus quantified product assessment for LCA. Here, beneficial synergism is possible between the two tools, as illustrated by some cases. These also illustrate that where full integration is suggested, in practice this is not achieved, thus in fact supporting the conclusions. 相似文献
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《Bioscience, biotechnology, and biochemistry》2013,77(11):2080-2081
We purified and studied two l-stereoselective carbonyl reductases from bakers’ yeast (Saccharomyces cerevisiae). One catalyzed exclusively the enantioselective reduction of carbonyl compounds such as β-keto esters and the other acted on α-acetoxy ketones and β-keto esters. The enzymes had identical molecular weights and catalyzed the l-stereoselective reduction of various carbonyl compounds with similar substrate specificity, but they were different proteins coded by different genes. 相似文献
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Y. Y. Stroylova G. G. Kiselev E. V. Schmalhausen V. I. Muronetz 《Biochemistry. Biokhimii?a》2014,79(8):761-775
This review highlights the modern perception of anomalous folding of the prion protein and the role of chaperones therein. Special attention is paid to prion proteins from mammalian species, which are prone to amyloid-like prion diseases due to a unique aggregation pathway. Despite being a significantly popular current subject of investigations, the etiology, structure, and function of both normal and anomalous prion proteins still hold many mysteries. The most interesting of those are connected to the interaction with chaperone system, which is responsible for stabilizing protein structure and disrupting aggregates. In the case of prion proteins the following question is of the most importance — can chaperones influence different stages of the formation of pathological aggregates (these vary from intermediate oligomers to mature amyloid-like fibrils) and the whole transition from native prion protein to its amyloid-like fibril-enriched form? The existing inconsistencies and ambiguities in the observations made so far can be attributed to the fact that most of the investigations did not take into account the type and functional state of the chaperones. This review discusses in detail our previous works that have demonstrated fundamental differences between eukaryotic and prokaryotic chaperones in the action exerted on the amyloid-like transformation of the prion protein along with the dependence of the observed effects on the functional state of the chaperone. 相似文献
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Rahel Schumacher Dario Cazzoli No?mi Eggenberger Basil Preisig Tobias Nef Thomas Nyffeler Klemens Gutbrod Jean-Marie Annoni René M. Müri 《PloS one》2015,10(11)
Purpose
We aimed at further elucidating whether aphasic patients’ difficulties in understanding non-canonical sentence structures, such as Passive or Object-Verb-Subject sentences, can be attributed to impaired morphosyntactic cue recognition, and to problems in integrating competing interpretations.Methods
A sentence-picture matching task with canonical and non-canonical spoken sentences was performed using concurrent eye tracking. Accuracy, reaction time, and eye tracking data (fixations) of 50 healthy subjects and 12 aphasic patients were analysed.Results
Patients showed increased error rates and reaction times, as well as delayed fixation preferences for target pictures in non-canonical sentences. Patients’ fixation patterns differed from healthy controls and revealed deficits in recognizing and immediately integrating morphosyntactic cues.Conclusion
Our study corroborates the notion that difficulties in understanding syntactically complex sentences are attributable to a processing deficit encompassing delayed and therefore impaired recognition and integration of cues, as well as increased competition between interpretations. 相似文献6.
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Similarities and differences in the effect of cocaine on [alpha]-adrenergic and muscarinic receptors were shown in three experimental models. The postsynaptic stimulating effect of cocaine, mediated by [alpha]-adrenergic receptors was revealed in uninnervated chick amnion and innervated rat vas deferens. In vas deferens cocaine caused an increase of the amount of active [alpha]-adrenergic receptors, the appearance of an additional receptor pool, and change in the dimerization level. Cocaine acted as an antagonist on muscarinic receptors of the chick amnion. The inhibition by cocaine of muscarinic receptors in the rat brain cortex membranes led to a decrease in the number of receptors and their partial monomerization. Thus, cocaine influences both the [alpha]-adrenergic and the muscarinic response at the receptor level. Experiments on various objects have shown that cocaine activates the [alpha]-adrenergic response and inhibits the muscarinic one. 相似文献
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Mt Kilimanjaro is Africa’s highest mountain, and an icon for a country famous for its mammalian fauna. The distribution and abundance of small mammals on the mountain are poorly known. Here we document the distribution of shrews and rodents along an elevational gradient on the southeastern versant of Kilimanjaro. Five sites were sampled with elevational center points of 2000, 2500, 3000, 3500 and 4000 m, using a systematic methodology of standard traps and pitfall lines, to inventory the shrews and rodents of the slope. Sixteen species of mammal were recorded, including 6 shrew and 10 rodent species, and the greatest diversity of both was found at 3000 m, the elevational midpoint of the transect. No species previously unrecorded on Kilimanjaro were observed. Two genera of rodents that occur in nearby mountains (Hylomyscus and Beamys) were not recorded. Myosorex zinki, the only mammal endemic to Mt. Kilimanjaro, which previously was known by only a few specimens collected in the ericaceous or moorland habitat, was found in all but one (the lowest) of the sites sampled, and was one of the most widespread species of small mammal along the gradient. Two shrews (Crocidura allex and Sylvisorex granti) and one rodent (Dendromus insignis) were found throughout the entire transect, with Dendromus being observed at our highest trap point (4240 m). As in similar faunal surveys on other mountains of Tanzania, rainfall influenced the sample success of shrews, but not rodents. Trap success for rodents at 3500 m was notably low. This study contributes further justification for the conservation of the forest habitat of Mt. Kilimanjaro. 相似文献
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Petra Quillfeldt Yves Cherel Juan F. Masello Karine Delord Rona A. R. McGill Robert W. Furness Yoshan Moodley Henri Weimerskirch 《PloS one》2015,10(5)
Distant populations of animals may share their non-breeding grounds or migrate to distinct areas, and this may have important consequences for population differentiation and dynamics. Small burrow-nesting seabirds provide a suitable case study, as they are often restricted to safe breeding sites on islands, resulting in a patchy breeding distribution. For example, Thin-billed prions Pachyptila belcheri have two major breeding colonies more than 8,000 km apart, on the Falkland Islands in the south-western Atlantic and in the Kerguelen Archipelago in the Indian Ocean. We used geolocators and stable isotopes to compare at-sea movements and trophic levels of these two populations during their non-breeding season, and applied ecological niche models to compare environmental conditions in the habitat. Over three winters, birds breeding in the Atlantic showed a high consistency in their migration routes. Most individuals migrated more than 3000 km eastwards, while very few remained over the Patagonian Shelf. In contrast, all Indian Ocean birds migrated westwards, resulting in an overlapping nonbreeding area in the eastern Atlantic sector of the Southern Ocean. Geolocators and isotopic signature of feathers indicated that prions from the Falklands moulted at slightly higher latitudes than those from Kerguelen Islands. All birds fed on low trophic level prey, most probably crustaceans. The phenology differed notably between the two populations. Falkland birds returned to the Patagonian Shelf after 2-3 months, while Kerguelen birds remained in the nonbreeding area for seven months, before returning to nesting grounds highly synchronously and at high speed. Habitat models identified sea surface temperature and chlorophyll a concentration as important environmental parameters. In summary, we show that even though the two very distant populations migrate to roughly the same area to moult, they have distinct wintering strategies: They had significantly different realized niches and timing which may contribute to spatial niche partitioning. 相似文献
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Last summer we officially launched the Journal of Ethnobiology and Ethnomedicine, published by BioMedCentral, with the aim of establishing a serious, peer-reviewed, open-access online journal that focuses on the multidisciplinary, interdisciplinary, and transdisciplinary fields of ethnobiology and ethnomedicine, drawing on approaches and methods from both the social and biological sciences. The strong start vindicates the widely held belief that the journal responds to a real need within the research community. The success of the journal has been most gratifying. The steady influx of submissions of high scientific standards illustrates the strong demand for a dynamic, proactive, and open-minded scientific journal in these research areas. Our aim has been to dedicate JEE to the "scientific communities" worldwide, particularly those in the developing countries. 相似文献
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Throughout many arid lands of Africa, Australia and the United States, wildlife agencies provide water year-round for increasing game populations and enhancing biodiversity, despite concerns that water provisioning may favor species more dependent on water, increase predation, and reduce biodiversity. In part, understanding the effects of water provisioning requires identifying why and when animals visit water. Employing this information, by matching water provisioning with use by target species, could assist wildlife management objectives while mitigating unintended consequences of year-round watering regimes. Therefore, we examined if weather variables (maximum temperature, relative humidity [RH], vapor pressure deficit [VPD], long and short-term precipitation) and predator-prey relationships (i.e., prey presence) predicted water visitation by 9 mammals. We modeled visitation as recorded by trail cameras at Sevilleta National Wildlife Refuge, New Mexico, USA (June 2009 to September 2014) using generalized linear modeling. For 3 native ungulates, elk (Cervus Canadensis), mule deer (Odocoileus hemionus), and pronghorn (Antilocapra americana), less long-term precipitation and higher maximum temperatures increased visitation, including RH for mule deer. Less long-term precipitation and higher VPD increased oryx (Oryx gazella) and desert cottontail rabbits (Sylvilagus audubonii) visitation. Long-term precipitation, with RH or VPD, predicted visitation for black-tailed jackrabbits (Lepus californicus). Standardized model coefficients demonstrated that the amount of long-term precipitation influenced herbivore visitation most. Weather (especially maximum temperature) and prey (cottontails and jackrabbits) predicted bobcat (Lynx rufus) visitation. Mule deer visitation had the largest influence on coyote (Canis latrans) visitation. Puma (Puma concolor) visitation was solely predicted by prey visitation (elk, mule deer, oryx). Most ungulate visitation peaked during May and June. Coyote, elk and puma visitation was relatively consistent throughout the year. Within the diel-period, activity patterns for predators corresponded with prey. Year-round water management may favor species with consistent use throughout the year, and facilitate predation. Providing water only during periods of high use by target species may moderate unwanted biological costs. 相似文献
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Yanxing Chen Zhihou Liang Julie Blanchard Chun-Ling Dai Shenggang Sun Moon H. Lee Inge Grundke-Iqbal Khalid Iqbal Fei Liu Cheng-Xin Gong 《Molecular neurobiology》2013,47(2):711-725
Alzheimer’s disease (AD) can be divided into sporadic AD (SAD) and familial AD (FAD). Most AD cases are sporadic and result from multiple etiologic factors, including environmental, genetic, and metabolic factors, whereas FAD is caused by mutations in the presenilins or amyloid-β (Aβ) precursor protein (APP) genes. A commonly used animal model for AD is the 3xTg-AD transgenic mouse model, which harbors mutated presenilin 1, APP, and tau genes and thus represents a model of FAD. There is an unmet need in the field to characterize animal models representing different AD mechanisms, so that potential drugs for SAD can be evaluated preclinically in these animal models. A mouse model generated by intracerebroventricular (icv) administration of streptozocin (STZ), the icv-STZ mouse, shows many aspects of SAD. In this study, we compared the non-cognitive and cognitive behaviors as well as biochemical and immunohistochemical alterations between the icv-STZ mouse and the 3xTg-AD mouse. We found that both mouse models showed increased exploratory activity as well as impaired learning and spatial memory. Both models also demonstrated neuroinflammation, altered synaptic proteins and insulin/IGF-1 (insulin-like growth factor-1) signaling, and increased hyperphosphorylated tau in the brain. The most prominent brain abnormality in the icv-STZ mouse was neuroinflammation, and in the 3xTg-AD mouse it was elevation of hyperphosphorylated tau. These observations demonstrate the behavioral and neuropathological similarities and differences between the icv-STZ mouse and the 3xTg-AD mouse models and will help guide future studies using these two mouse models for the development of AD drugs. 相似文献
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《Biological reviews of the Cambridge Philosophical Society》2018,93(3):1363-1386
Amyloids are primarily known for their roles in neurodegenerative disorders, as well as in systemic diseases like diabetes. Evolutionary forces tend to maintain a healthy set of heritable characteristics, while eliminating toxic or unfavourable elements; but amyloids seem to represent an exception to this fundamental concept. In addition to their presence in mammals, amyloids also persist in the proteome of many lower organisms that may be linked with possible roles in survival, which are still unexplored. Herein, we address some unanswered questions regarding amyloids: are these well‐structured proteinaceous aggregates a by‐product of inefficient folding events, or have they been retained in our protein repertoire for as yet unknown functional roles; and how do protein misfolding and associated disorders originate, despite the presence of protein quality‐control systems inside the cells? This review aims to extend our current understanding about the multifaceted useful properties of amyloids and their functional interactions with other molecular pathways in various species; this may provide new insights to identify novel therapeutic strategies for ageing and neurodegenerative diseases. 相似文献
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Meagan J. Gillespie Dragana Stanley Honglei Chen John A. Donald Kevin R. Nicholas Robert J. Moore Tamsyn M. Crowley 《PloS one》2012,7(10)
Pigeon ‘milk’ and mammalian milk have functional similarities in terms of nutritional benefit and delivery of immunoglobulins to the young. Mammalian milk has been clearly shown to aid in the development of the immune system and microbiota of the young, but similar effects have not yet been attributed to pigeon ‘milk’. Therefore, using a chicken model, we investigated the effect of pigeon ‘milk’ on immune gene expression in the Gut Associated Lymphoid Tissue (GALT) and on the composition of the caecal microbiota. Chickens fed pigeon ‘milk’ had a faster rate of growth and a better feed conversion ratio than control chickens. There was significantly enhanced expression of immune-related gene pathways and interferon-stimulated genes in the GALT of pigeon ‘milk’-fed chickens. These pathways include the innate immune response, regulation of cytokine production and regulation of B cell activation and proliferation. The caecal microbiota of pigeon ‘milk’-fed chickens was significantly more diverse than control chickens, and appears to be affected by prebiotics in pigeon ‘milk’, as well as being directly seeded by bacteria present in pigeon ‘milk’. Our results demonstrate that pigeon ‘milk’ has further modes of action which make it functionally similar to mammalian milk. We hypothesise that pigeon ‘lactation’ and mammalian lactation evolved independently but resulted in similarly functional products. 相似文献
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This article is part of a Special Issue “Parental Care”.Mother–infant bonding is a characteristic of virtually all mammals. The maternal neural system may have provided the scaffold upon which other types of social bonds in mammals have been built. For example, most mammals exhibit a polygamous mating system, but monogamy and pair bonding between mating partners occur in ~ 5% of mammalian species. In mammals, it is plausible that the neural mechanisms that promote mother–infant bonding have been modified by natural selection to establish the capacity to develop a selective bond with a mate during the evolution of monogamous mating strategies. Here we compare the details of the neural mechanisms that promote mother–infant bonding in rats and other mammals with those that underpin pair bond formation in the monogamous prairie vole. Although details remain to be resolved, remarkable similarities and a few differences between the mechanisms underlying these two types of bond formation are revealed. For example, amygdala and nucleus accumbens–ventral pallidum (NA–VP) circuits are involved in both types of bond formation, and dopamine and oxytocin actions within NA appear to promote the synaptic plasticity that allows either infant or mating partner stimuli to persistently activate NA–VP attraction circuits, leading to an enduring social attraction and bonding. Further, although the medial preoptic area is essential for maternal behavior, its role in pair bonding remains to be determined. Our review concludes by examining the broader implications of this comparative analysis, and evidence is provided that the maternal care system may have also provided the basic neural foundation for other types of strong social relationships, beyond pair bonding, in mammals, including humans. 相似文献
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Telomeric DNA is present at the ends of eukaryotic chromosomes and is bound by telomere “capping” proteins, which are the
(Cdc13–Stn1–Ten1) CST complex, Ku (Yku70–Yku80), and Rap1–Rif1–Rif2 in budding yeast. Inactivation of any of these complexes
causes telomere “uncapping,” stimulating a DNA damage response (DDR) that frequently involves resection of telomeric DNA and
stimulates cell cycle arrest. This is presumed to occur because telomeres resemble one half of a DNA double-strand break (DSB).
In this review, we outline the DDR that occurs at DSBs and compare it to the DDR occurring at uncapped telomeres, in both
budding yeast and metazoans. We give particular attention to the resection of DSBs in budding yeast by Mre11–Xrs2–Rad50 (MRX),
Sgs1/Dna2, and Exo1 and compare their roles at DSBs and uncapped telomeres. We also discuss how resection uncapped telomeres
in budding yeast is promoted by the by 9–1–1 complex (Rad17–Mec3–Ddc1), to illustrate how analysis of uncapped telomeres can
serve as a model for the DDR elsewhere in the genome. Finally, we discuss the role of the helicase Pif1 and its requirement
for resection of uncapped telomeres, but not DSBs. Pif1 has roles in DNA replication and mammalian and plant CST complexes
have been identified and have roles in global genome replication. Based on these observations, we suggest that while the DDR
at uncapped telomeres is partially due to their resemblance to a DSB, it may also be partially due to defective DNA replication.
Specifically, we propose that the budding yeast CST complex has dual roles to inhibit a DSB-like DDR initiated by Exo1 and
a replication-associated DDR initiated by Pif1. If true, this would suggest that the mammalian CST complex inhibits a Pif1-dependent
DDR. 相似文献