57 resultados para critical period of competition

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Although psychogenic aphonia is considered to be a conversion disorder, aphonic patients are primarily treated symptomatically. This is because it is considered of overriding importance to elicit a voice quickly to avoid fixation of the aphonia. The aim of this study was to show that, for patients exhibiting the symptom of voicelessness, not eliciting the voice immediately will not lead to a permanent aphonia.

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Since the first description of spinal and epidural anaesthesia, postdural puncture headache (PDPH) is a well known complication. Its prophylaxis and treatment has been studied and discussed for more than 100 years, but the evidence is still limited. Due to relatively low prevalence of PDPH, prospective RCTs are often missing, and the frequently self-limiting character of PDPH impedes an adequate interpretation of results from studies without a control group. Taking side effects and complications into account, a prophylactic treatment of PDPH cannot be recommended. In case of PDPH, non-opioid analgesics are the first choice treatment. The epidural blood patch remains the mainstay of severe PDPH therapy. Noninvasive therapies like theophylline, sumatriptan and ACTH can be an alternative. However, an evidence-based recommendation is lacking. The development of standard operating procedures for accidental dural punctures and PDPH is recommended.

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Alpine snowbeds are habitats where the major limiting factors for plant growth are herbivory and a small time window for growth due to late snowmelt. Despite these limitations, snowbed vegetation usually forms a dense carpet of palatable plants due to favourable abiotic conditions for plant growth within the short growing season. These environmental characteristics make snowbeds particularly interesting to study the interplay of facilitation and competition. We hypothesised an interplay between resource competition and facilitation against herbivory. Further, we investigated whether these predicted neighbour effects were species-specific and/or dependent on ontogeny, and whether the balance of positive and negative plant–plant interactions shifted along a snowmelt gradient. We determined the neighbour effects by means of neighbour removal experiments along the snowmelt gradient, and linear mixed model analyses. The results showed that the effects of neighbour removal were weak but generally consistent among species and snowmelt dates, and depended on whether biomass production or survival was considered. Higher total biomass and increased fruiting in removal plots indicated that plants competed for nutrients, water, and light, thereby supporting the hypothesis of prevailing competition for resources in snowbeds. However, the presence of neighbours reduced herbivory and thereby also facilitated survival. For plant growth the facilitative effects against herbivores in snowbeds counterbalanced competition for resources, leading to a weak negative net effect. Overall the neighbour effects were not species-specific and did not change with snowmelt date. Our finding of counterbalancing effects of competition and facilitation within a plant community is of special theoretical value for species distribution models and can explain the success of models that give primary importance to abiotic factors and tend to overlook interrelations between biotic and abiotic effects on plants.

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Diagnosis, staging, and treatment monitoring are still suboptimal for most genitourinary tumours. Diffusion-weighted magnetic resonance imaging (DW-MRI) has already shown promise as a noninvasive imaging modality in the early detection of microstructural and functional changes in several pathologies of various organs.

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Combined pegylated interferon (PegIFN) and ribavirin represents the standard therapy for patients with chronic hepatitis C (CHC), which allows for sustained viral response (SVR) in up to 90% of patients depending on certain viral and host factors. Clinical studies have demonstrated the importance of adherence to therapy, that is, the ability of patients to tolerate and sustain a fully dosed therapy regimen. Adherence is markedly impaired by treatment-related adverse effects. In particular, haemolytic anaemia often requires dose reduction or termination of ribavirin treatment, which compromises treatment efficacy. Recent evidence points to a beneficial role of recombinant erythropoietin (EPO) in alleviating ribavirin-induced anaemia thereby improving quality of life, enabling higher ribavirin dosage and consequently improving SVR. However, no general consensus exists regarding the use of EPO for specific indications: its optimal dosing, treatment benefits and potential risks or cost efficiency. The Swiss Association for the Study of the Liver (SASL) has therefore organized an expert meeting to critically review and discuss the current evidence and to phrase recommendations for clinical practice. A consensus was reached recommending the use of EPO for patients infected with viral genotype 1 developing significant anaemia below 100 g/L haemoglobin and a haematocrit of <30% during standard therapy to improve quality of life and sustain optimal ribavirin dose. However, the evidence supporting its use in patients with pre-existing anaemia, non-1 viral genotypes, a former relapse or nonresponse, liver transplant recipients and cardiovascular or pulmonary disease is considered insufficient.

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Excessive inflammatory host response increases morbidity and mortality associated with seasonal respiratory influenza, and highly pathogenic virus strains are characterized by massive infiltration of monocytes and/or macrophages that produce a storm of injurious cytokines.

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Hypocretins (orexins) are hypothalamic neuropeptides which are involved in a wide range of physiological processes in mammals including central pain processing. Genetic studies in humans evidenced a role for the hypocretinergic system in cluster headache (CH).

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The objective of this systematic review was to assess the 5- and 10-year survival of implant-supported fixed dental prostheses (FDPs) and to describe the incidence of biological and technical complications.