Search results for " selection"
showing 10 items of 1271 documents
Adaptive significance of synchronous chorusing in an acoustically signalling wolf spider
2004
Synchronous sexual signalling is a behavioural phenomenon that has received considerable theoretical interest, but surprisingly few empirical tests have been conducted. Here, we present a set of experiments designed to determine (i) whether the sexual signalling of the drumming wolf spider Hygrolycosa rubrofasciata is synchronous, and (ii) whether the synchrony may have evolved through female preference. Using controlled playback experiments, we found that males actively synchronized their drumming bouts with other males and females significantly preferred closely synchronized drumming clusters compared with loose clusters. In loose clusters, the first drumming signals attracted the most fe…
Ramucirumab versus placebo as second-line treatment in patients with advanced hepatocellular carcinoma following first-line therapy with sorafenib (R…
2015
Background: VEGF and VEGF receptor-2-mediated angiogenesis contribute to hepatocellular carcinoma pathogenesis. Ramucirumab is a recombinant IgG1 monoclonal antibody and VEGF receptor-2 antagonist. We aimed to assess the safety and efficacy of ramucirumab in advanced hepatocellular carcinoma following first-line therapy with sorafenib. Methods: In this randomised, placebo-controlled, double-blind, multicentre, phase 3 trial (REACH), patients were enrolled from 154 centres in 27 countries. Eligible patients were aged 18 years or older, had hepatocellular carcinoma with Barcelona Clinic Liver Cancer stage C disease or stage B disease that was refractory or not amenable to locoregional therapy…
Hyperalgesia and opioid switching
2005
Opioids, intended to abolish pain, can unexpectedly produce hyperalgesia, particularly during rapid opioid escalation. Opioid switching could be a therapeutic option in a condition of opioid-induced tolerance or hyperalgesia, but conversion ratios between opioids are difficult to apply in this context and require strict surveillance and expertise. This situation is challenging, because the rapid escalation of opioid doses, possibly due to the development of opioid-induced tolerance, can cause hyperalgesia. To avoid this adverse effect, clinicians need to refine their assessment of pain treatment and consider opioid switching. The authors present a case report in which switching from fentan…
Short-term and long-term results of cardiac surgery in elderly and very elderly patients
2011
Objective: Cardiac operations in elderly patients are increasingly frequent and imply major clinical, ethical, and economic issues. Operative and 5-year results of cardiac operations in patients aged 79 years or more are known in limited series, and a debate is ongoing on the appropriateness of selection of patients for surgery. Methods: We retrospectively reviewed our experience in 6802 patients aged 79 years or more who had received a cardiac operation. Surgical candidates were selected according to functional status, crude operative risk, and social context and were managed according to a multimodality protocol. Results: Mean age was 82 years and surgery was nonelective in 1613 cases (23…
Results of mitral valve repair for Barlow disease (bileaflet prolapse) via right minithoracotomy versus conventional median sternotomy: a randomized …
2011
Objective: The results of mitral repair for complex Barlow valves are adequate and support earlier intervention. It is unknown whether these results are reproducible in the context of minimally invasive surgery via right minithoracotomy. Methods: We randomized patients with Barlow mitral disease (bileaflet prolapse) to have conventional open repair via median sternotomy (MS group) or minimally invasive (MI group) repair. Repair was done using polytetrafluoroethylene chordal reimplantation for both leaflets. In the MI group, we adopted right minithoracotomy, peripheral cannulation, external aortic clamping, and surgery under direct vision. Results: Both groups comprised 70 patients. The oper…
Matters of scale: positive allometry and the evolution of male dimorphisms
2005
J.L.T. was funded by a Biotechnology and Biological Sciences Research Council research fellowship, J.S.K. by the Academy of Finland, and N.R.L. by a Natural Environment Research Council research fellowship. The developmental independence of alternative phenotypes is key to evolutionary theories of phenotypic plasticity and the origins of diversity. Male dimorphisms associated with alternative reproductive tactics are widely cited examples of such facultative expression of divergent fitness optima. Current models for the evolution of male dimorphisms invoke a size-dependent threshold at which the phenotype is reprogrammed. We use predictions derived from allometric modeling to test for the e…
Rapid growth predisposes broilers to necrotic enteritis
2019
Over the past 50 years, intentional genetic selection within the broiler industry has led to major improvements in both body weight gain (BWG) and feed conversion efficiency. Next to its economic advantages, enhancing BWG can increase the risk of metabolic and skeletal disorders. The aim of this study was to examine whether higher BWG is a predisposing factor for broiler necrotic enteritis. In this study, 300 broilers were challenged with Clostridium perfringens using a well-established, previously described challenge model. It was found that birds with higher body weight (BW) and BWG before challenge were predisposed to develop more severe necrotic enteritis lesions. After challenge, the a…
Dosing issues with non-vitamin K antagonist oral anticoagulants for the treatment of non-valvular atrial fibrillation: Why we should not underdose ou…
2018
Summary Non-vitamin K antagonist oral anticoagulants (NOACs) – dabigatran, rivaroxaban, apixaban and edoxaban – are well established in terms of preventing stroke or systemic embolism in patients with non-valvular atrial fibrillation and high thromboembolism risk. When prescribed incorrectly, NOACs are associated with an increased risk of ischaemic events and bleeding. Current NOAC labels explicitly address dose adjustments according to age, body weight, renal function and concomitant treatment with P-glycoprotein inhibitors. The required dose adjustments vary significantly from molecule to molecule, thereby creating a complex dose adjustment environment. Furthermore, recommendations suppor…
Liver transplantation for severe alcoholic hepatitis: A multicenter Italian study
2022
There is increasing evidence that early liver transplantation (eLT), performed within standardized protocols can improve survival in severe alcoholic hepatitis (sAH). The aim of the study was to assess outcomes after eLT for sAH in four Italian LT centers and to compare them with non-responders to medical therapy excluded from eLT. Patients admitted for sAH (2013–2019), according to NIAAA criteria, were included. Patients not responding to medical therapy were placed on the waiting list for eLT after a strict selection. Histological features of explanted livers were evaluated. Posttransplant survival and alcohol relapse were evaluated. Ninety-three patients with severe AH were evaluated (65…
Oh sister, where art thou? Spatial population structure and the evolution of an altruistic defence trait.
2014
The evolution of parasite virulence and host defences is affected by population structure. This effect has been confirmed in studies focusing on large spatial scales, whereas the importance of local structure is not well understood. Slavemaking ants are social parasites that exploit workers of another species to rear their offspring. Enslaved workers of the host species Temnothorax longispinosus have been found to exhibit an effective post-enslavement defence behaviour: enslaved workers were observed killing a large proportion of the parasites’ offspring. As enslaved workers do not reproduce, they gain no direct fitness benefit from this ‘rebellion’ behaviour. However, there may be an indir…