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21.
van Oers Lauran Guinée Jeroen B. Heijungs Reinout Schulze Rita Alvarenga Rodrigo A. F. Dewulf Jo Drielsma Johannes Sanjuan-Delmás David Kampmann Tobias C. Bark Glenn Uriarte Ainara Garcia Menger Pierre Lindblom Mats Alcon Lucas Ramos Manuel Sevilla Torres Juan Manuel Escobar 《The International Journal of Life Cycle Assessment》2020,25(11):2255-2273
The International Journal of Life Cycle Assessment - The methods for assessing the impact of using abiotic resources in life cycle assessment (LCA) have always been heavily debated. One of the main... 相似文献
22.
Evy A. de Nijs Lettice C. Hicks Ainara Leizeaga Albert Tietema Johannes Rousk 《Global Change Biology》2019,25(3):1005-1015
Climate change will alter precipitation patterns with consequences for soil C cycling. An understanding of how fluctuating soil moisture affects microbial processes is therefore critical to predict responses to future global change. We investigated how long‐term experimental field drought influences microbial tolerance to lower moisture levels (“resistance”) and ability to recover when rewetted after drought (“resilience”), using soils from a heathland which had been subjected to experimental precipitation reduction during the summer for 18 years. We tested whether drought could induce increased resistance, resilience, and changes in the balance between respiration and bacterial growth during perturbation events, by following a two‐tiered approach. We first evaluated the effects of the long‐term summer drought on microbial community functioning to drought and drying–rewetting (D/RW), and second tested the ability to alter resistance and resilience through additional perturbation cycles. A history of summer drought in the field selected for increased resilience but not resistance, suggesting that rewetting after drought, rather than low moisture levels during drought, was the selective pressure shaping the microbial community functions. Laboratory D/RW cycles also selected for communities with a higher resilience rather than increased resistance. The ratio of respiration to bacterial growth during D/RW perturbation was lower for the field drought‐exposed communities and decreased for both field treatments during the D/RW cycles. This suggests that cycles of D/RW also structure microbial communities to respond quickly and efficiently to rewetting after drought. Our findings imply that microbial communities can adapt to changing climatic conditions and that this might slow the rate of soil C loss predicted to be induced by future cyclic drought. 相似文献
23.
Bragina L Melone M Fattorini G Torres-Ramos M Vallejo-Illarramendi A Matute C Conti F 《Journal of neurochemistry》2006,99(1):134-141
In rat frontal cortex, extracellular levels of glutamate are raised by the anti-psychotic drug clozapine. We have recently shown that a significant reduction in the levels of the glutamate transporter GLT-1 may be one of the mechanisms responsible for this elevation. Here we studied whether GLT-1 down-regulation induced by chronic clozapine treatment is associated with changes in the expression of synaptophysin, synaptosome-associated protein of 25 kDa (SNAP-25) and vesicular glutamate transporter 1 (VGLUT1), three major presynaptic proteins involved in neurotransmitter release. Quantitative high-resolution confocal microscopy studies in vivo showed that GLT-1 down-regulation is closely associated with a significant increase in synaptophysin, but not SNAP-25 and VGLUT1, expression. This was confirmed in vitro studies, and in western blotting studies of synaptophysin, SNAP-25 and VGLUT1. In addition, our results show that, following clozapine treatment, synaptophysin expression increases in the very cortical regions in which GLT-1 expression is down-regulated. These findings suggest that part of the effects of clozapine may be exerted via an action on the presynaptic machinery involved in neurotransmitter release. 相似文献
24.
Humberto Astibia Aitor Payros Xabier Pereda Suberbiola Javier Elorza Ana Berreteaga Nestor Etxebarria Ainara Badiola Josep Tosquella 《Facies》2005,50(3-4):463-475
Sirenian vertebrae and ribs have been recently discovered from two Middle Eocene localities of the Pamplona Basin, Navarre (western Pyrenees). These outcrops correspond to different lower Bartonian lithostratigraphic units: the lower part of the Pamplona Marl Formation (Uztarrotz site) and the upper part of the Ardanatz Sandstone (Ardanatz site). The former represents a deep and low-energy sea floor far away from a deltaic slope; the Ardanatz environment probably corresponds to a semi-closed deltaic bay periodically affected by catastrophic floods (i.e., fluvial hyperpycnal flows). The presence of epibiontic activity suggests that the bones were exposed for a while prior to the burial. The histological structures are well preserved except in the peripheral region, where tubular-like microstructures filled by pyrite and iron oxides probably correspond to microbial bioerosion. The major mineral component of the fossil bones is francolite (carbonate fluorapatite). In the Ardanatz samples there is evidence of secondary francolite due to the late replacement of original carbonate fluorapatite through internal fractures. The Ardanatz and Uztarrotz sirenian fossils do not show any evidence of reelaboration. They have similar sum of rare earth elements (REE) concentrations relative to the host rock, but comparatively lower than in other vertebrate fossil bones. This feature may be due to the dense compact structure of pachyosteosclerotic sirenian bones. 相似文献
25.
Supplementary feeding stations, or “vulture restaurants”, are common conservation management tools. While a number of studies have investigated the consequences of surplus food on the population dynamics of scavengers, relatively little is known about the effects of such practices at the individual level. Within the long-term monitored breeding population of Canarian Egyptian vultures (Neophron percnopterus majorensis) we investigated individual bird’s patterns of use of a supplementary feeding station at Fuerteventura (Canary Islands), over the course of breeding (2001, 2002; 2004-2011) and non-breeding seasons (2000-2010). Our results show that during the breeding season the individual use of the supplementary feeding station was inversely related to the distance to the breeding territory, which suggests the existence of central-place foraging constraints. In addition, larger birds of poor body-condition and individuals that ultimately failed to fledge young were detected more frequently at the feeding station. During the non-breeding season, and because most breeding birds abandoned the breeding territories, the overall abundance of Egyptian vultures at the feeding station grew. Moreover, the only variable increasing the probability of presence of individuals was poor body condition so that birds with lower wing residual visited the feeding station more frequently. Supplementary feeding may benefit individuals who would otherwise have been subject to selective pressures. From our results it follows that this conservation strategy must be used with caution because it can have consequences on an individual level and thus potentially affect the viability of endangered populations. 相似文献
26.
Toxic but drank: gustatory aversive compounds induce post-ingestional malaise in harnessed honeybees
Background
Deterrent substances produced by plants are relevant due to their potential toxicity. The fact that most of these substances have an unpalatable taste for humans and other mammals contrasts with the fact that honeybees do not reject them in the range of concentrations in which these compounds are present in flower nectars. Here we asked whether honeybees detect and ingest deterrent substances and whether these substances are really toxic to them.Results
We show that pairing aversive substances with an odor retards learning of this odor when it is subsequently paired with sucrose. Harnessed honeybees in the laboratory ingest without reluctance a considerable volume (20 µl) of various aversive substances, even if some of them induce significant post-ingestional mortality. These substances do not seem, therefore, to be unpalatable to harnessed bees but induce a malaise-like state that in some cases results in death. Consistently with this finding, bees learning that one odor is associated with sugar, and experiencing in a subsequent phase that the sugar was paired with 20 µl of an aversive substance (devaluation phase), respond less than control bees to the odor and the sugar. Such stimulus devaluation can be accounted for by the malaise-like state induced by the aversive substances.Conclusion
Our results indicate that substances that taste bitter to humans as well as concentrated saline solutions base their aversive effect on the physiological consequences that their ingestion generates in harnessed bees rather than on an unpalatable taste. This conclusion is only valid for harnessed bees in the laboratory as freely-moving bees might react differently to aversive compounds could actively reject aversive substances. Our results open a new possibility to study conditioned taste aversion based on post-ingestional malaise and thus broaden the spectrum of aversive learning protocols available in honeybees. 相似文献27.
Down syndrome, the most common genetic disorder leading to mental retardation, is caused by the presence of all or part of
an extra copy of chromosome 21. At relatively early ages, Down syndrome patients develop progressive formation and extracellular
aggregation of amyloid-β peptide, considered as one of the causal factors for the pathogenesis of Alzheimer’s disease. This
neuropathological hallmark has been attributed to the overexpression of APP but could also be contributed by other HSA21 genes. BACE2 maps to HSA21 and is homologous to BACE1, a β-secretase involved in the amyloidogenic pathway of APP proteolysis, and thus it has been hypothesized that the co-overexpression
of both genes could contribute to Alzheimer’s like neuropathology present in Down syndrome. The aim of the present study has
been to analyse the impact of the co-overexpression of BACE2 and APP, using a double transgenic mouse model. Double transgenic mice did not present any neurological or sensorimotor alterations,
nor genotype-dependent anxiety-like behaviour or age-associated cognitive dysfunction. Interestingly, TgBACE2-APP mice showed
deregulation of BACE2 expression levels that were significantly increased with respect to single TgBACE2 mice. Co-overexpression
of BACE2 and APP did not increase amyloid-β peptide concentration in brain. Our results suggest that the in vivo effects of APP are not exacerbated by BACE2 co-overexpression but may have some protective effects in specific behavioural and cognitive domains in transgenic mice. 相似文献
28.
Esther Sebastián‐González José Antonio Sánchez‐Zapata José Antonio Donázar Nuria Selva Ainara Cortés‐Avizanda Fernando Hiraldo Miguel Blázquez Francisco Botella Marcos Moleón 《Ibis》2013,155(4):881-885
Carrion consumption patterns in vertebrate scavenger communities may be influenced by several interacting factors. We assessed the effects of the number of scavenger species and the presence of obligate scavengers (vultures) on carcass detection and consumption times, and the structure (nestedness) of the scavenger assemblage by exploring consumption patterns of lagomorph carcasses provided experimentally. Carcass detection and consumption times were strongly inversely related to vulture presence, whereas scavenger richness had a low contribution, except when interacting with vulture presence. However, none of the scavenger communities presented a nested pattern, perhaps because of the small size of lagomorphs, which prevents large numbers of scavengers and interspecific interactions occurring at one carcass. Our results suggest that scavenger species richness, especially the presence of vultures, increases scavenging efficiency. 相似文献
29.
Nuclear PTEN regulates the APC-CDH1 tumor-suppressive complex in a phosphatase-independent manner 总被引:1,自引:0,他引:1
PTEN is a frequently mutated tumor suppressor gene that opposes the PI3K/AKT pathway through dephosphorylation of phosphoinositide-3,4,5-triphosphate. Recently, nuclear compartmentalization of PTEN was found as a key component of its tumor-suppressive activity; however its nuclear function remains poorly defined. Here we show that nuclear PTEN interacts with APC/C, promotes APC/C association with CDH1, and thereby enhances the tumor-suppressive activity of the APC-CDH1 complex. We find that nuclear exclusion but not phosphatase inactivation of PTEN impairs APC-CDH1. This nuclear function of PTEN provides a straightforward mechanistic explanation for the fail-safe cellular senescence response elicited by acute PTEN loss and the tumor-suppressive activity of catalytically inactive PTEN. Importantly, we demonstrate that PTEN mutant and PTEN null states are not synonymous as they are differentially sensitive to pharmacological inhibition of APC-CDH1 targets such as PLK1 and Aurora kinases. This finding identifies a strategy for cancer patient stratification and, thus, optimization of targeted therapies. PAPERCLIP: 相似文献
30.
Development of a Screening Tool for Sleep Disordered Breathing in Children Using the Phone Oximeter?
Ainara Garde Parastoo Dehkordi Walter Karlen David Wensley J. Mark Ansermino Guy A. Dumont 《PloS one》2014,9(11)