97 resultados para Persistence of ground cover


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The role of competition for light among plants has long been recognized at local scales, but its potential importance for plant species' distribution at larger spatial scales has largely been ignored. Tree cover acts as a modulator of local abiotic conditions, notably by reducing light availability below the canopy and thus the performance of species that are not adapted to low-light conditions. However, this local effect may propagate to coarser spatial grains. Using 6,935 vegetation plots located across the European Alps, we fit Generalized Linear Models (GLM) for the distribution of 960 herbs and shrubs species to assess the effect of tree cover at both plot and landscape grain sizes (~ 10-m and 1-km, respectively). We ran four models with different combinations of variables (climate, soil and tree cover) for each species at both spatial grains. We used partial regressions to evaluate the independent effects of plot- and landscape-scale tree cover on plant communities. Finally, the effects on species' elevational range limits were assessed by simulating a removal experiment comparing the species' distribution under high and low tree cover. Accounting for tree cover improved model performance, with shade-tolerant species increasing their probability of presence at high tree cover whereas shade-intolerant species showed the opposite pattern. The tree cover effect occurred consistently at both plot and landscape spatial grains, albeit strongest at the former. Importantly, tree cover at the two grain sizes had partially independent effects on plot-scale plant communities, suggesting that the effects may be transmitted to coarser grains through meta-community dynamics. At high tree cover, shade-intolerant species exhibited elevational range contractions, especially at their upper limit, whereas shade-tolerant species showed elevational range expansions at both limits. Our findings suggest that the range shifts for herb and shrub species may be modulated by tree cover dynamics.

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BACKGROUND/AIMS: Controversies still exist regarding the evaluation of growth hormone deficiency (GHD) in childhood at the end of growth. The aim of this study was to describe the natural history of GHD in a pediatric cohort. METHODS: This is a retrospective study of a cohort of pediatric patients with GHD. Cases of acquired GHD were excluded. Univariate logistic regression was used to identify predictors of GHD persisting into adulthood. RESULTS: Among 63 identified patients, 47 (75%) had partial GHD at diagnosis, while 16 (25%) had complete GHD, including 5 with multiple pituitary hormone deficiencies. At final height, 50 patients underwent repeat stimulation testing; 28 (56%) recovered and 22 (44%) remained growth hormone (GH) deficient. Predictors of persisting GHD were: complete GHD at diagnosis (OR 10.1, 95% CI 2.4-42.1), pituitary stalk defect or ectopic pituitary gland on magnetic resonance imaging (OR 6.5, 95% CI 1.1-37.1), greater height gain during GH treatment (OR 1.8, 95% CI 1.0-3.3), and IGF-1 level <-2 standard deviation scores (SDS) following treatment cessation (OR 19.3, 95% CI 3.6-103.1). In the multivariate analysis, only IGF-1 level <-2 SDS (OR 13.3, 95% CI 2.3-77.3) and complete GHD (OR 6.3, 95% CI 1.2-32.8) were associated with the outcome. CONCLUSION: At final height, 56% of adolescents with GHD had recovered. Complete GHD at diagnosis, low IGF-1 levels following retesting, and pituitary malformation were strong predictors of persistence of GHD. © 2015 S. Karger AG, Basel.

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Lymphomas arising from NK or γδ-T cells are very aggressive diseases and little is known regarding their pathogenesis. Here we report frequent activating mutations of STAT3 and STAT5B in NK/T-cell lymphomas (n=51), γδ-T-cell lymphomas (n=43) and their cell lines (n=9) through next generation and/or Sanger sequencing. STAT5B N642H is particularly frequent in all forms of γδ-T-cell lymphomas. STAT3 and STAT5B mutations are associated with increased phosphorylated protein and a growth advantage to transduced cell lines or normal NK cells. Growth-promoting activity of the mutants can be partially inhibited by a JAK1/2 inhibitor. Molecular modelling and surface plasmon resonance measurements of the N642H mutant indicate a marked increase in binding affinity of the phosphotyrosine-Y699 with the mutant histidine. This is associated with the prolonged persistence of the mutant phosphoSTAT5B and marked increase of binding to target sites. Our findings suggest that JAK-STAT pathway inhibition may represent a therapeutic strategy.

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New oral targeted anticancer therapies are revolutionizing cancer treatment by transforming previously deadly malignancies into chronically manageable conditions. Nevertheless, drug resistance, persistence of cancer stem cells, and adverse drug effects still limit their ability to stabilize or cure malignant diseases in the long term. Response to targeted anticancer therapy is influenced by tumor genetics and by variability in drug concentrations. However, despite a significant inter-patient pharmacokinetic variability, targeted anticancer drugs are essentially licensed at fixed doses. Their therapeutic use could however be optimized by individualization of their dosage, based on blood concentration measurements via the therapeutic drug monitoring (TDM). TDM can increase the probability of therapeutic responses to targeted anticancer therapies, and would help minimize the risk of major adverse reactions.

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PurposeTo evaluate the impact of traditional French summer vacation on visual acuity and spectral domain-optical coherence tomography (SD-OCT) of Wet AMD patients being treated with intravitreal Ranibizumab.MethodsThis was a consecutive, comparative, single-centre, prospective analysis. All patients who were being treated with intravitreal injection of 0.5 mg ranibizumab at Cergy Pontoise Hospital, Department of Ophthalmology between July 2013 and September 2014 were included. Patients were divided into two groups: (A) patients who skipped one ranibizumab intravitreal injection during holidays, and (B) patients who received injection during their holidays. Evaluations occurred prior to traditional holiday (baseline) and 2 months later, consisting of BCVA using ETDRS, and a complete ophthalmic examination that included slit-lamp biomicroscopy, fundus examination, fluorescein angiography (FA), indocyanine green angiography (ICGA), and spectral domain-optical coherence tomography (SD-OCT). All patients were being treated with PRN anti-VEGF regimen and criteria for reinjection included a visual acuity loss >5 ETDRS letters and/or an increase of central retinal thickness, presence of subretinal fluid, intraretinal fluid, or pigment epithelium detachment. If reinjection criteria were not met, patients were advised to return in 4 weeks.ResultsThe mean visual acuity change was -0.071±0.149 (LogMAR) in group A and +0.003±0.178 in group B (P=0.041). At the second visit (2 months after preholidays visit), 61.8% of patients in group A had SRF and/or intraretinal cysts, and only 27.6% of patients in group B. There was a significant difference in the persistence of fluid between the two groups (P=0.007, χ(2)-test).ConclusionThis cases series demonstrated the detrimental impact of holidays on visual acuity in patients treated with ranibizumab for AMD, which, in spite of their treatment regimen, still leave in vacation. Therefore, it is important to convey the message of treatment adherence to patients, despite their need of holidays.

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Internationally, policies for attracting highly-skilled migrants have become the guidelines mainly used by the Organisation for Economic Co-operation and Development (OECD) countries. Governments are implementing specific procedures to capture and facilitate their mobility. However, all professions are not equal when it comes to welcoming highly-skilled migrants. The medical profession, as a protective market, is one of these. Taking the case of non-EU/EEA doctors in France, this paper shows that the medical profession defined as the closed labour market, remains the most controversial in terms of professional integration of migrants, protectionist barriers to migrant competition and challenge of medical shortage. Based on the path-dependency approach, this paper argues that non-EU/EEA doctors' issues in France derive from a complex historical process of interaction between standards settled in the past, particularly the historical power of medical corporatism, the unexpected long-term effects of French hospital reforms of 1958, and budgetary pressures. Theoretically, this paper shows two significant findings. Firstly, the French medical system has undergone a series of transformations unthinkable in the strict sense of a path-dependence approach: an opening of the medical profession to foreign physicians in the context of the Europeanisation of public policy, acceptance of non-EU/EEA doctors in a context of medical shortage and budgetary pressures. Secondly, there is no change of the overall paradigm: significantly, the recruitment policies of non-EU/EEA doctors continue to highlight the imprint of the past and reveal a significant persistence of prejudices. Non-EU/EEA doctors are not considered legitimate doctors even if they have the qualifications of physicians which are legitimate in their country and which can be recognised in other receiving countries.

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OBJECTIVE: There is currently no guideline regarding the management of neurogenic detrusor overactivity (NDO) refractory to intra-detrusor botulinum toxin injections. The primary objective of the present study was to find a consensus definition of failure of botulinum toxin intra-detrusor injections for NDO. The secondary objective was to report current trends in the managment of NDO refractory to botulinum toxin. METHODS: A survey was created, based on data drawn from current literature, and sent via e-mail to all the experts form the Group for research in neurourology in french language (GENULF) and from the comittee of neurourology of the French urological association (AFU). The experts who did not answer to the first e-mail were contacted again twice. Main results from the survey are presented and expressed as numbers and proportions. RESULTS: Out of the 42 experts contacted, 21 responded to the survey. Nineteen participants considered that the definition of failure should be a combination of clinical and urodynamics criteria. Among the urodynamics criteria, the persistence of a maximum detrusor pressure>40cm H2O was the most supported by the experts (18/21, 85%). According to the vast majority of participants (19/21, 90.5%), the impact of injections on urinary incontinence should be included in the definition of failure. Regarding the management, most experts considered that the first line treatment in case of failure of a first intra-detrusor injection of Botox(®) 200 U should be a repeat injection of Botox(®) at a higher dosage (300 U) (15/20, 75%), regardless of the presence or not of urodynamics risk factors of upper tract damage (16/20, 80%). CONCLUSION: This work has provided a first overview of the definition of failure of intra-detrusor injections of botulinum toxin in the management of NDO. For 90.5% of the experts involved, the definition of failure should be clinical and urodynamic and most participants (75%) considered that, in case of failure of a first injection of Botox(®) 200 U, repeat injection of Botox(®) 300 U should be the first line treatment. Level of proof 4.