Search results for "Population"

A Study of the Health of Seafaring Workers of Valencia, Spain

1997

Under the auspices of the Service of Maritime Health of the Marine Social Institute of Valencia, Spain, the health status of seafaring workers from Valencia was evaluated. An epidemiologic study was carried out based on 707 pre-embarkation health examinations, collecting information about the health problems of these workers and their associated risk factors. The data were analyzed to estimate population frequencies and the corresponding 95% confidence intervals. Significance among groups was calculated by the chi-square test (p0.05). Relative risks were calculated in comparisons of the seafaring workers with the general population of Valencia. High incidences of ophthalmologic disorders we…

The social gradient in stress and depressive symptoms among adolescent girls: A systematic review and narrative synthesis

2019

Aim: Socioeconomic inequality is found to negatively influence mental health, but studies investigating the relationship between socioeconomic status (SES) and specific common mental health problems such as stress and depressive symptoms in the general adolescent population are needed. Moreover, gender gaps in mental health among adolescents are evident, but there is a lack of studies that investigate socioeconomic differences in mental health within genders. As girls report consistently more depressive symptoms than do boys, this systematic review specifically investigates whether socioeconomic status is associated with stress and depressive symptoms among adolescent girls in the general p…

¿Podemos favorecer el proceso de aprendizaje y la inclusión social y académica en la universidad de los estudiantes con más dificultades? Propuesta d…

2018

Durante el primer curso universitario, los estudiantes deben hacer frente a nuevas exigencias académicas, (evaluación, metodologías docentes...), con el fin de superar ese primer curso, al tiempo de integrarse socialmente en un contexto, la universidad, nuevo para ellos. Para ello, deben adquirir o reforzar distintas habilidades. La literatura científica ha evidenciado la relación entre estas variables con el rendimiento académico y el ajuste al primer año de universidad: actitudes ante el aprendizaje (Gargallo et al, 2007-A-), estrategias de aprendizaje (Gargallo et al., 2009), estrés académico (Rayle y Chung, 2007; Robotham y Julian 2006), autoeficacia académica (Palacio et al., 2012; Sal…

Effect of Antioxidants on Microsomal Enzymes of Rat Liver

1978

Rat diet was supplemented with butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) or ethoxyquin (EQ) for 14 days, and hepatic microsomal epoxide hydratase (EH) and monooxygenase were subsequently studied in vitro. The antioxidants increased EH activity. The increase was marked with BHT (factor 3) and EQ (factor 4) and was paralleled by an increase in a protein band on SDS polyacrylamide gels which migrated together with purified rat hepatic EH. A slight but nonsignificant increase in cytochrome P450 content and a moderate increase in ethoxycoumarin deethylation and cytochrome b5 content was also observed while aryl hydrocarbon hydroxylase (AHH) activity was not elevated. Irrever…

The role of local adaptation in the relationship between an endangered root hemiparasite Euphrasia rostkoviana, and its host, Agrostis capillaris

1999

We experimentally studied the role of local adaptation and the co-evolutionary relationship between an annual, endangered root hemiparasite Euphrasia rostkoviana and its main host Agrostis capillaris. According to our hypothesis, the existence of local adaptation in hemiparasites should be observable in better hemiparasite performance when attached to A. capillaris hosts originating from Euphrasia populations. After one month of growth, the height and the number of leaves of hemiparasites were not affected by the origin of their hosts. The differences in growth were due to between population effects. The situation remained constant after three months. Hemiparasite biomass was not affected b…

Susceptibility to Cry proteins of a SpanishOstrinia nubilalisglasshouse population repeatedly sprayed withBacillus thuringiensisformulations

2013

Ostrinia nubilalis Hubner (Lepidoptera: Crambidae), a major pest of corn in temperate climates, can feed on other crops due to its polyphagous behaviour. In particular, this species became a serious problem in some sweet pepper commercial glasshouses in south-eastern Spain repeatedly sprayed with Bacillus thuringiensis (Bt) products to control Spodoptera exigua Hubner (Lepidoptera: Noctuidae). The susceptibility of an O. nubilalis colony established from individuals collected in these Bt-sprayed glasshouses was compared with a reference laboratory colony. Differences in susceptibility between the two colonies to Cry1Aa, Cry1Ab, Cry1Ac and Cry2Aa proteins were found. However, our results ind…

Populationsgenetische Untersuchungen �ber die Pseudocholinesterase-Varianten bei Ungarn und Deutschen

1965

Community structure and the evolution of aposematic coloration

2002

Studies on the evolution of aposematic coloration (prey coloration advertising for unpalatability) have mainly focused on predator psychology in simplified single-prey species systems. We chose, instead, to model population dynamics on the community level. We studied the invasion by an aposematic phenotype in the presence and absence of another prey species. The single-prey and two-prey models differed in two major ways. First, with two prey species the invasion was possible only with a weak aposematic signal, whereas with a single prey species there was no such an upper limit for signal strength. Second, with a single prey species, increase of the aposematic phenotype always resulted in ra…

Can adaptation lead to extinction?

2005

Ever since J.B.S. Haldane proposed the idea, evolutionary biologists are aware that individual level adaptations do not necessarily lead to optimal population performance. A few deeply mathematical models, drawing from a diverse range of systems, even predict that individual selection can lead to the extinction of the whole population, a phenomenon which has become known as evolutionary suicide. Due to the complexity of both following adaptation and determining the exact cause of an extinction, evolutionary suicide has remained untested empirically. However, three recent empirical studies suggest that it may occur, and that suicide should be taken seriously as a potentially important evolut…

Habitat fragmentation compromises the population dynamic of the globally near-threatened Straight-billed Reedhaunter (Limnoctites rectirostris)

2018

AbstractUnderstanding the consequences of habitat fragmentation to biological populations is crucial to develop sound conservation polices. The Straight-billed Reedhaunter (Limnoctites rectirostris) is a little known and threatened Passeriform that is highly dependent Erygo wetlands patches. Here, we evaluated the effects of habitat fragmentation on populations of the Straight-billed Reedhaunter, during the construction of a water reservoir in southern Brazil. During eight months, we monitored five Eryngo wetlands patches occupied (n=3) and no occupied (n=2) by Straight-billed Reedhaunter individuals, collecting data on their temporal occupancy patterns and registering new fragmentation eve…