Search results for "SELECTION"
showing 10 items of 1940 documents
Loup-assisted technique to create arterio-venous fistulas in elderly. A single centre experience
2019
AIMS: The radio-cephalic arteriovenous fistula (RCAVF) is the first choice treatment in end-stage renal disease patients. In the last few years, the hemodialysis population has shown a high percentage of elderly patients (> 65 year old) with comorbidities, mainly vascular diseases, which may adversely affect their vascular access success. The aim of this study was to evaluate the effectiveness of a loup-assisted technique to create RCAVFs in over 65 patients. PATIENTS AND METHODS: 98 consecutive patients with renal failure were prospectively observed. The patient were divided in relation to their age (> 65 year old; < 65 year old). In both groups, a microsurgical distal RCAVF was c…
Do editors have a silver bullet? an agent-based model of peer review
2014
This paper presents an agent-based model of peer review that looks at the effect of different editorial policies of referee selection. We tested four author/referee matching scenarios as follows: random selection of referees, selection of referees with a similar status to submission authors, selection of higher-skilled and lower skilled referees. We tested these scenarios against three types of referee behaviour, i.e., fair, unreliable and strategic and measured their implications for the quality and efficiency of the process. Results show that in case of randomness of referee judgment, any editorial policy is detrimental for peer review. If referees behave strategically, certain matching p…
Do aging employees benefit from self-regulative strategies? : A follow-up study
2020
SOC-strategies (selection, optimization, and compensation) are crucial for well-being and adaptation throughout the life course. The workforce is aging rapidly, thus the age-conditional premises of SOC theory require attention. This study explored (1) whether older employees used SOC strategies more often (compared to younger employees), and (2) whether older employees benefited more from SOC strategies in relation to occupational well-being (job burnout, work engagement). The study was based on follow-up data including three occupational subsamples of different age (N = 1,020). There were no significant age-conditional differences in the take-up of SOC strategies. However, older (white-col…
Inflammation and oxidative stress in vertebrate host–parasite systems
2008
Innate, inflammation-based immunity is the first line of vertebrate defence against micro-organisms. Inflammation relies on a number of cellular and molecular effectors that can strike invading pathogens very shortly after the encounter between inflammatory cells and the intruder, but in a non-specific way. Owing to this non-specific response, inflammation can generate substantial costs for the host if the inflammatory response, and the associated oxygen-based damage, get out of control. This imposes strong selection pressure that acts to optimize two key features of the inflammatory response: the timing of activation and resolution (the process of downregulation of the response). In this p…
Development and validation of prediction model to estimate 10-year risk of all-cause mortality using modern statistical learning methods: a large pop…
2021
Abstract Background In increasingly ageing populations, there is an emergent need to develop a robust prediction model for estimating an individual absolute risk for all-cause mortality, so that relevant assessments and interventions can be targeted appropriately. The objective of the study was to derive, evaluate and validate (internally and externally) a risk prediction model allowing rapid estimations of an absolute risk of all-cause mortality in the following 10 years. Methods For the model development, data came from English Longitudinal Study of Ageing study, which comprised 9154 population-representative individuals aged 50–75 years, 1240 (13.5%) of whom died during the 10-year follo…
RESISTANCE AND TOLERANCE IN A HOST PLANT–HOLOPARASITIC PLANT INTERACTION: GENETIC VARIATION AND COSTS
2002
Host organisms are believed to evolve defense mechanisms (i.e., resistance and/or tolerance) under selective pressures exerted by natural enemies. A prerequisite for the evolution of resistance and tolerance is the existence of genetic variation in these traits for natural selection to act. However, selection for resistance and/or tolerance may be constrained by negative genetic correlations with other traits that affect host fitness. We studied genetic variation in resistance and tolerance against parasitic infection and the potential fitness costs associated with these traits using a novel study system, namely the interaction between a flowering plant and a parasitic plant. In this system…
Relatedness affects competitive performance of a parasitic plant (Cuscuta europaea) in multiple infections.
2004
Theoretical models predict that parasite relatedness affects the outcome of competition between parasites, and the evolution of parasite virulence. We examined whether parasite relatedness affects competition between parasitic plants (Cuscuta europaea) that share common host plants (Urtica dioica). We infected hosts with two parasitic plants that were either half-siblings or nonrelated. Relative size asymmetry between the competing parasites was significantly higher in the nonrelated infections compared to infections with siblings. This higher asymmetry was caused by the fact that the performance of some parasite genotypes decreased and that of others increased when grown in multiple infect…
Principal component analysis for the selection of variables in the application of the H-point and generalised H-point standard addition method
2000
The present paper deals with the selection of variables for the H-point and generalised H-point standard additions methods (HPSAM and GHPSAM, respectively). Both methods are applied for the resolution of spectroscopic interfered signals in the UV-vis range. The HPSAM is a suitable method for the resolution of binary and ternary mixtures when the interferent is known. The GHPSAM is applied for the resolution of samples that contain unknown interferents. In this paper, a method based on the study of a principal components analysis (PCA) for the selection of variables for the HPSAM and GHPSAM is proposed. The PCA results show the isolation of the analyte signal from the sample signal, achieved…
Experimental verification of position-dependent angular-momentum selection rules for absorption of twisted light by a bound electron
2018
We analyze the multipole excitation of atoms with twisted light, i.e., by a vortex light field that carries orbital angular momentum. A single trapped $^{40}$Ca$^+$ ion serves as a localized and positioned probe of the exciting field. We drive the $S_{1/2} \to D_{5/2}$ transition and observe the relative strengths of different transitions, depending on the ion's transversal position with respect to the center of the vortex light field. On the other hand, transition amplitudes are calculated for a twisted light field in form of a Bessel beam, a Bessel-Gauss and a Gauss-Laguerre mode. Analyzing experimental obtained transition amplitudes we find agreement with the theoretical predictions at a…
Atypical functioning of female genitalia explains monandry in a butterfly
2021
Monandrous species are rare in nature, especially in animals where males transfer nutrients to females in the ejaculate. The proximate mechanisms responsible for monandry are poorly studied. In butterflies and moths, the male transfers a nutritious spermatophore into the corpus bursae (CB) of the female. The CB is a multifunctional organ that digests the spermatophore and has partial control of the post-mating sexual receptivity of the female. The spermatophore distends the CB and the post-mating sexual receptivity of the female is inversely proportional to the degree of distension. The CB of many butterfly species has a muscular sheath whose contractions mechanically contribute to digest t…