256 research outputs found

    Risk of Climate-Related Impacts on Global Rangelands – A Review and Modelling Study

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    Climate change threatens the ability of global rangelands to provide food, support livelihoods and deliver important ecosystems services. The extent and magnitude of potential impacts are however poorly understood. In this study, we review the risk of climate impacts along the rangeland systems food supply chain. We also present results from biophysical modelling simulations and spatial data analyses to identify where and to what extent rangelands may be at climatic risk. Although a quantification of the net impacts of climate change on rangeland production systems is beyond the reach of our current understanding, there is strong evidence that there will be impacts throughout the supply chain, from feed and animal production to processing, storage, transport, retailing and human consumption. Regarding grazing biomass production, this study finds that mean herbaceous biomass is projected to decrease across global rangelands between 2000 and 2050 under RCP 8.5 (-4.7%), while inter- (year-to-year) and intra- (month-to-month) annual variabilities are projected to increase (+21.3% and +8.2%, respectively). These averaged global estimates mask large spatial heterogeneities, with 74% of global rangeland area projected to experience a decline in mean biomass, 64% an increase in inter-annual variability and 54% an increase in intra-annual variability. The potentially most damaging vegetation trends for livestock production (i.e., simultaneous decreases in mean biomass and increases in inter-annual variability) are projected to occur in rangeland communities that are currently the most vulnerable (here, with the lowest livestock productivities and economic development levels and with the highest projected increases in human population densities). Large uncertainties remain as to climate futures and the exposure and responses of the interlinked human and natural systems to climatic changes over time. Consequently, adaptation choices will need to build on robust methods of designing, implementing and evaluating detailed development pathways, and account for a wide range of possible futures

    Differential effects of tactile high- and low-frequency stimulation on tactile discrimination in human subjects

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    <p>Abstract</p> <p>Background</p> <p>Long-term potentiation (LTP) and long-term depression (LTD) play important roles in mediating activity-dependent changes in synaptic transmission and are believed to be crucial mechanisms underlying learning and cortical plasticity. In human subjects, however, the lack of adequate input stimuli for the induction of LTP and LTD makes it difficult to study directly the impact of such protocols on behavior.</p> <p>Results</p> <p>Using tactile high- and low-frequency stimulation protocols in humans, we explored the potential of such protocols for the induction of perceptual changes. We delivered tactile high-frequency and low-frequency stimuli (t-HFS, t-LFS) to skin sites of approximately 50 mm<sup>2 </sup>on the tip of the index finger. As assessed by 2-point discrimination, we demonstrate that 20 minutes of t-HFS improved tactile discrimination, while t-LFS impaired performance. T-HFS-effects were stable for at least 24 hours whereas t-LFS-induced changes recovered faster. While t-HFS changes were spatially very specific with no changes on the neighboring fingers, impaired tactile performance after t-LFS was also observed on the right middle-finger. A central finding was that for both t-LFS and t-HFS perceptual changes were dependent on the size of the stimulated skin area. No changes were observed when the stimulated area was very small (< 1 mm<sup>2</sup>) indicating special requirements for spatial summation.</p> <p>Conclusion</p> <p>Our results demonstrate differential effects of such protocols in a frequency specific manner that might be related to LTP- and LTD-like changes in human subjects.</p

    Scribble modulates the MAPK/Fra1 pathway to disrupt luminal and ductal integrity and suppress tumour formation in the mammary gland

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    Polarity coordinates cell movement, differentiation, proliferation and apoptosis to build and maintain complex epithelial tissues such as the mammary gland. Loss of polarity and the deregulation of these processes are critical events in malignant progression but precisely how and at which stage polarity loss impacts on mammary development and tumourigenesis is unclear. Scrib is a core polarity regulator and tumour suppressor gene however to date our understanding of Scrib function in the mammary gland has been limited to cell culture and transplantation studies of cell lines. Utilizing a conditional mouse model of Scrib loss we report for the first time that Scrib is essential for mammary duct morphogenesis, mammary progenitor cell fate and maintenance, and we demonstrate a critical and specific role for Scribble in the control of the early steps of breast cancer progression. In particular, Scrib-deficiency significantly induced Fra1 expression and basal progenitor clonogenicity, which resulted in fully penetrant ductal hyperplasia characterized by high cell turnover, MAPK hyperactivity, frank polarity loss with mixing of apical and basolateral membrane constituents and expansion of atypical luminal cells. We also show for the first time a role for Scribble in mammalian spindle orientation with the onset of mammary hyperplasia being associated with aberrant luminal cell spindle orientation and a failure to apoptose during the final stage of duct tubulogenesis. Restoring MAPK/Fra1 to baseline levels prevented Scrib-hyperplasia, whereas persistent Scrib deficiency induced alveolar hyperplasia and increased the incidence, onset and grade of mammary tumours. These findings, based on a definitive genetic mouse model provide fundamental insights into mammary duct maturation and homeostasis and reveal that Scrib loss activates a MAPK/Fra1 pathway that alters mammary progenitor activity to drive premalignancy and accelerate tumour progression

    Indiscriminable sounds determine the direction of visual motion

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    On cross-modal interactions, top-down controls such as attention and explicit identification of cross-modal inputs were assumed to play crucial roles for the optimization. Here we show the establishment of cross-modal associations without such top-down controls. The onsets of two circles producing apparent motion perception were accompanied by indiscriminable sounds consisting of six identical and one unique sound frequencies. After adaptation to the visual apparent motion with the sounds, the sounds acquired a driving effect for illusory visual apparent motion perception. Moreover, the pure tones with each unique frequency of the sounds acquired the same effect after the adaptation, indicating that the difference in the indiscriminable sounds was implicitly coded. We further confrimed that the aftereffect didnot transfer between eyes. These results suggest that the brain establishes new neural representations between sound frequency and visual motion without clear identification of the specific relationship between cross-modal stimuli in early perceptual processing stages

    What do people with lung cancer and stroke expect from patient navigation?: A qualitative study in Germany

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    Objective This qualitative study investigated patients' needs and wishes in relation to patient navigation. Design A qualitative interview study was conducted. Participants were invited to take part in three in-depth interviews over a period of 6-12 months. Thematic analysis was used. Setting Interviewees were sought in the Berlin metropolitan area of Germany in academic university hospitals, in rehabilitation clinics and through self-help organisations. Participants The sample consisted of individuals diagnosed with lung cancer (n=20) or stroke (n=20). Results From the perspective of interviewees, patient navigators should function as consistent contact persons, present during the whole care trajectory. Their role would be to guide patients through an often confusing healthcare landscape, offering practical, advisory and emotional assistance corresponding to patients' needs. The study shows that-independent of the disease-participants had similar expectations and needs regarding support from navigators. Conclusion For chronic and complex diseases-as is the case with lung cancer and stroke-it appears less important for navigators to fulfil disease-specific tasks. Rather, they should ensure that patients' more general needs, in relation to social, practical and emotional support, are met in a way that suits their individual wishes. Following these results, patient navigation programmes might be designed to include generic elements, which should then be adapted to the infrastructure in a particular healthcare region and to the particularities of a specific healthcare system

    The complete genome sequence and comparative genome analysis of the high pathogenicity Yersinia enterocolitica strain 8081

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    The human enteropathogen, Yersinia enterocolitica, is a significant link in the range of Yersinia pathologies extending from mild gastroenteritis to bubonic plague. Comparison at the genomic level is a key step in our understanding of the genetic basis for this pathogenicity spectrum. Here we report the genome of Y. enterocolitica strain 8081 (serotype 0:8; biotype 1B) and extensive microarray data relating to the genetic diversity of the Y. enterocolitica species. Our analysis reveals that the genome of Y. enterocolitica strain 8081 is a patchwork of horizontally acquired genetic loci, including a plasticity zone of 199 kb containing an extraordinarily high density of virulence genes. Microarray analysis has provided insights into species-specific Y. enterocolitica gene functions and the intraspecies differences between the high, low, and nonpathogenic Y. enterocolitica biotypes. Through comparative genome sequence analysis we provide new information on the evolution of the Yersinia. We identify numerous loci that represent ancestral clusters of genes potentially important in enteric survival and pathogenesis, which have been lost or are in the process of being lost, in the other sequenced Yersinia lineages. Our analysis also highlights large metabolic operons in Y. enterocolitica that are absent in the related enteropathogen, Yersinia pseudotuberculosis, indicating major differences in niche and nutrients used within the mammalian gut. These include clusters directing, the production of hydrogenases, tetrathionate respiration, cobalamin synthesis, and propanediol utilisation. Along with ancestral gene clusters, the genome of Y. enterocolitica has revealed species-specific and enteropathogen-specific loci. This has provided important insights into the pathology of this bacterium and, more broadly, into the evolution of the genus. Moreover, wider investigations looking at the patterns of gene loss and gain in the Yersinia have highlighted common themes in the genome evolution of other human enteropathogens

    Can routine register data be used to identify vulnerable lung cancer patients of suboptimal care in a German comprehensive cancer centre?

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    Objectives Several patient factors have been described to influence access to optimal cancer care like socioeconomic factors or place of residence. In this study, we investigate whether data routinely collected in a clinical cancer registry can be used to identify populations of lung cancer patients with increased risk of not receiving optimal cancer care.Methods We analysed data of 837 lung cancer patients extracted from the clinical cancer registry of a German university hospital. We compared patient populations by two indicators of optimal care, namely implementation of tumour board meeting recommendations as well as the timeliness of care.Results There was a high rate of implementation of tumour board meeting recommendations of 94.4%. Reasons for non-implementation were mainly a patient's own wish or a worsening of the health situation. Of all patient parameters, only tumour stage was associated with the two optimal care indicators.Conclusion Using routine data from a clinical cancer registry, we were not able to identify patient populations at risk of not getting optimal care and the implementation of guideline-conform care appeared to be very high in this setting. However, limitations were the ambiguity of optimal care indicators and availability of parameters predictive for patients' vulnerability.Clinical epidemiolog

    An extended association screen in multiple sclerosis using 202 microsatellite markers targeting apoptosis-related genes does not reveal new predisposing factors

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    Apoptosis, the programmed death of cells, plays a distinct role in the etiopathogenesis of Multiple sclerosis (MS), a common disease of the central nervous system with complex genetic background. Yet, it is not clear whether the impact of apoptosis is due to altered apoptotic behaviour caused by variations of apoptosis-related genes. Instead, apoptosis in MS may also represent a secondary response to cellular stress during acute inflammation in the central nervous system. Here, we screened 202 apoptosis-related genes for association by genotyping 202 microsatellite markers in initially 160 MS patients and 160 controls, both divided in 4 sets of pooled DNA samples, respectively. When applying Bonferroni correction, no significant differences in allele frequencies were detected between MS patients and controls. Nevertheless, we chose 7 markers for retyping in individual DNA samples, thereby eliminating 6 markers from the list of candidates. The remaining candidate, the ERBB3 gene microsatellite, was genotyped in additional 245 MS patients and controls. No association of the ERBB3 marker with the disease was detected in these additional cohorts. In consequence, we did not find further evidence for apoptosis-related genes as predisposition factors in MS

    Reprogramming of orientation columns in visual cortex : a domino effect

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    Abstract : Cortical organization rests upon the fundamental principle that neurons sharing similar properties are co-located. In the visual cortex, neurons are organized into orientation columns. In a column, most neurons respond optimally to the same axis of an oriented edge, that is, the preferred orientation. This orientation selectivity is believed to be absolute in adulthood. However, in a fully mature brain, it has been established that neurons change their selectivity following sensory experience or visual adaptation. Here, we show that after applying an adapter away from the tested cells, neurons whose receptive fields were located remotely from the adapted site also exhibit a novel selectivity in spite of the fact that they were not adapted. These results indicate a robust reconfiguration and remapping of the orientation domains with respect to each other thus removing the possibility of an orientation hole in the new hypercolumn. These data suggest that orientation columns transcend anatomy, and are almost strictly functionally dynamic
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