Search results for " selection"
showing 10 items of 1271 documents
Evolution of external female genital mutilation : why do males harm their mates?
2017
Sperm competition may select for male reproductive traits that influence female mating or oviposition rate. These traits may induce fitness costs to the female; however, they may be costly for the males as well as any decrease in female fitness also affects male fitness. Male adaptations to sperm competition manipulate females by altering not only female behaviour or physiology, but also female morphology. In orb-weaving spiders, mating may entail mutilation of external structures of the female genitalia, which prevents genital coupling with subsequent males. Here, we present a game theoretical model showing that external female genital mutilation is favoured even under relatively high cost…
Interactions between the sexual identity of the nervous system and the social environment mediate lifespan in Drosophila melanogaster
2018
Sex differences in lifespan are ubiquitous, but the underlying causal factors remain poorly understood. Inter- and intrasexual social interactions are well known to influence lifespan in many taxa, but it has proved challenging to separate the role of sex-specific behaviours from wider physiological differences between the sexes. To address this problem, we genetically manipulated the sexual identity of the nervous system—and hence sexual behaviour—in Drosophila melanogaster, and measured lifespan under varying social conditions. Consistent with previous studies, masculinization of the nervous system in females induced male-specific courtship behaviour and aggression, while nervous system f…
La Sala Parpalló en el Centre Cultural La Beneficència (1995-1999)
2020
During the period 1995-1999, the Sala Parpalló was located in the Beneficència Cultural Center of Valencia, sharing the place with the spaces of the Museum of Prehistory, the Museum of Ethnology and the IVEI. In the investigation it exposed a technical file for each of the 57 self-produced exhibitions carried out in the period and a selection of the studies that accompanied them: the files are displayed chronologically according to the procedures used. The work concludes with the analysis of the objectives that were mainly all the programming: 1) Sala Parpalló as an integrated project; 2) Studies and exhibitions around the Valencian Cultural Imaginary; 3) Analysis of the postmodern crisis; …
Measuring higher-order cognitive skills with multiple choice questions:potentials and pitfalls of Finnish teacher education entrance
2023
This mixed methods study examines the structure of the multiple-choice exam for student selection in Finnish teacher education. Through qualitative content analysis, we categorized multiple-choice ques-tions into items that assessed lower-and higher-order cognitive processes based on the Revised Bloom's Taxonomy. Exploratory and confirmatory factor analyses yielded four factors that represented lower-and higher-order cognitive processing skills and comprehension of empirical and theoretical items. These were associated with matriculation examination grades, especially with the average grade and the mother tongue grade. When developing future multiple-choice exams for admissions, we recommen…
Global diversity in the TAS2R38 bitter taste receptor: revisiting a classic evolutionary PROPosal
2016
AbstractThe ability to taste phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) is a polymorphic trait mediated by the TAS2R38 bitter taste receptor gene. It has long been hypothesized that global genetic diversity at this locus evolved under pervasive pressures from balancing natural selection. However, recent high-resolution population genetic studies of TAS2Rs suggest that demographic events have played a critical role in the evolution of these genes. We here utilized the largest TAS2R38 database yet analyzed, consisting of 5,589 individuals from 105 populations, to examine natural selection, haplotype frequencies and linkage disequilibrium to estimate the effects of both selectio…
Measurement of the AtmosphericνeSpectrum with IceCube
2015
We present a measurement of the atmospheric $\nu_e$ spectrum at energies between 0.1 TeV and 100 TeV using data from the first year of the complete IceCube detector. Atmospheric $\nu_e$ originate mainly from the decays of kaons produced in cosmic-ray air showers. This analysis selects 1078 fully contained events in 332 days of livetime, then identifies those consistent with particle showers. A likelihood analysis with improved event selection extends our previous measurement of the conventional $\nu_e$ fluxes to higher energies. The data constrain the conventional $\nu_e$ flux to be $1.3^{+0.4}_{-0.3}$ times a baseline prediction from a Honda's calculation, including the knee of the cosmic-…
Origin of Life, Theories Of
2017
Modern advances in biology, geology, chemistry, and astronomy have allowed us to elaborate models and hypotheses on the origin of life on Earth within the framework of the evolutionary theory. About four billion years ago, a rich inventory of organic compounds accumulated on the planet, as a product of volcanic, atmospheric, and cosmic chemistry. As chemical systems became increasingly more complex, a critical point was reached with the appearance of self-replicative polymers. This marks the possibility of optimizing abiotic systems by natural selection and historical contingency, which were added to the determinism of abiotic chemistry. A landmark of the origin of life was the articulation…
Insurance league: Italy vs. U.K
2003
Insurers are competing by adopting product innovations that provide the insured with integrated coverage for actuarial and financial risks. This article compares the contract structures of blended life policies between the insurance markets in Italy and the United Kingdom within the context of asset-liability management and welfare analysis. © Emerald Backfiles 2007.
Adaptive scheduling of acceleration and gyroscope for motion artifact cancelation in photoplethysmography
2022
Background and objective: Recently, various algorithms have been introduced using wrist-worn photo-plethysmography (PPG) to provide high accuracy of instantaneous heart rate (HR) estimation, including during high-intensity exercise. Most studies focus on using acceleration and/or gyroscope signals for the motion artifact (MA) reference, which attenuates or cancels out noise from the MA-corrupted PPG signals. We aim to open and pave the path to find an appropriate MA reference selection for MA cancelation in PPG.Methods: We investigated how the acceleration and gyroscope reference signals correlate with the MAs of the distorted PPG signals and derived both mathematically and experimentally a…
The role of parasitism in adaptive radiations – when might parasites promote and when might they constrain ecological speciation?
2012
Research on speciation and adaptive radiation has flourished during the past decades, yet factors underlying initiation of reproductive isolation often remain unknown. Parasites represent important selective agents and have received renewed attention in speciation research. We review the literature on parasite-mediated divergent selection in context of ecological speciation and present empirical evidence for three nonexclusive mechanisms by which parasites might facilitate speciation: reduced viability or fecundity of immigrants and hybrids, assortative mating as a pleiotropic by-product of host adaptation, and ecologically-based sexual selection. We emphasise the lack of research on specia…