999 resultados para Fellman, Jacob
Resumo:
Organic residue application into soil alter the emission of gases to atmosphere and CO2, CH4, N2O may contribute to increase the greenhouse effect. This experiment was carried out in a restoration area on a dystrophic Ultisol (PVAd) to quantify greenhouse gas (GHG) emissions from soil under castor bean cultivation, treated with sewage sludge (SS) or mineral fertilizer. The following treatments were tested: control without N; FertMin = mineral fertilizer; SS5 = 5 t ha-1 SS (37.5 kg ha-1 N); SS10 = 10 t ha-1 SS (75 kg ha-1 N); and SS20 = 20 t ha-1 SS (150 kg ha-1 N). The amount of sludge was based on the recommended rate of N for castor bean (75 kg ha-1), the N level of SS and the mineralization fraction of N from SS. Soil gas emission was measured for 21 days. Sewage sludge and mineral fertilizers altered the CO2, CH4 and N2O fluxes. Soil moisture had no effect on GHG emissions and the gas fluxes was statistically equivalent after the application of FertMin and of 5 t ha-1 SS. The application of the entire crop N requirement in the form of SS practically doubled the Global Warming Potential (GWP) and the C equivalent emissions in comparison with FertMin treatments.
Resumo:
Male dominance hierarchies are usually linked to relative body size and to weapon size, that is, to determinants of fighting ability. Secondary sexual characters that are not directly used as weapons could still be linked to dominance if they reveal determination or overall health and vigour and hence, indirectly, fighting ability. We studied the mating behaviour of the minnow, Phoxinus phoxinus, a cyprinid fish in which males develop breeding tubercles during the spawning season. The function of these breeding tubercles is still not clear. Using microsatellite markers, we determined male reproductive success under controlled conditions. The minnows were territorial and quickly established a dominance hierarchy at the beginning of the spawning season. Dominance was strongly and positively linked to fertilization success. Although body size and number of breeding tubercles were not significantly correlated in our sample, both large males and males with many breeding tubercles were more dominant and achieved higher fertilization success than small males or males with few tubercles. We found multimale fertilization in most clutches, suggesting that sperm competition is important in this species. Females showed behaviour that may be linked to spawning decision, that is, male dominance might not be the only determinant of male reproductive success in minnows
Resumo:
Les récents progrès de la laparoscopie ont modifié l'approche chirurgicale des patientes atteintes d'un cancer de l'endomètre. Le centre Swissendos Fribourg en collaboration avec l'AGO (Groupe de travail pour la gynécologie oncologique) et l'AGE (Groupe de travail pour la gynécologie endoscopique) ont entrepris d'élaborer un consensus basé sur l'évidence pour la pratique de la laparoscopie dans le traitement du cancer de l'endomètre. L'objectif a été de définir une approche propre à la Suisse en fournissant aux praticiens une aide à la prise en charge. Recent advance in laparoscopy have changed the surgical approach of endometrial cancer patients. The Swissendos Center, Fribourg, in collaboration with AGO (Groupe de travail pour la gynécologie oncologique) and AGE (groupe de travail pour la gynécologie endoscopique) have established a consensus based on the available evidence for the use of laparoscopy in the management of patients with endometrial cancer The main objective was to define Swiss clinical practice guidelines appropriate to the country and consistent with the needs of the physicians.
Resumo:
In recent years, numerous cases of morphological gonadal alterations in fish have been recorded throughout the world and across a wide range of species. In the whitefish Coregonus fatioi from the pre-alpine Lake Thun (Switzerland), the frequency of gonadal alterations is particularly high and the variety of alteration types large. Little is known about the proximal causes and the direct consequences of these morphological features on population persistence. In particular, the potential for the observed alterations to be the phenotypic expression of reduced genetic quality has not yet been addressed. In this study, we used offspring survival during embryogenesis as a proximate indicator of male genetic quality and tested whether the presence of gonadal alterations in males is an indicator of reduced quality. Embryos resulted from in vitro fertilizations of gametes from 126 males and females. We found no significant correlation between embryo survival and gonadal alteration in adults. Our findings suggest that in C. fatioi of Lake Thun, alterations in gonad morphology are not a phenotypic expression of variation in genetic quality.
Resumo:
Aquest és un article de síntesi que analitza sobretot l'anomenat Grand Tour i la cerca de l'ideal hel·lenic per part de tot un llarg seguit de personatges. Ells i els seus llibres i textos, anomenats aquí i dels quals se'n recullen nombrosos passatges, han estat veritablement significatius en la història del redescobriment europeu de Grècia: George Wheler, Jacob Spon, marquès de Nointel, James Stuart, Nicholas Revett, Robert Wood, Johann Joachim Winckelmann, Antiquities of Athens, Antiquities of Ionia, Richard Chandler, Lord Elgin, Lord Byron, Konstantinos P. Kavafis, etc.
Resumo:
Este es un artículo de síntesis que analiza sobre todo el llamado Grand Tour y la búsqueda del ideal helénico por parte de una larga serie de personajes. Ellos y sus libros y textos, ciados aquí y de los cuales se recogen numerosos pasajes, han sido verdaderamente significativos en la historia del redescubrimiento europeo de Grecia: George Wheler, Jacob Spon, marquès de Nointel, James Stuart, Nicholas Revett, Robert Wood, Johann Joachim Winckelmann, Antiquities of Athens, Antiquities of Ionia, Richard Chandler, Lord Elgin, Lord Byron, Konstantinos P. Kavafis, etc.
Resumo:
We use cryo-electron microscopy to compare 3D shapes of 158 bp long DNA minicircles that differ only in the sequence within an 18 bp block containing either a TATA box or a catabolite activator protein binding site. We present a sorting algorithm that correlates the reconstructed shapes and groups them into distinct categories. We conclude that the presence of the TATA box sequence, which is believed to be easily bent, does not significantly affect the observed shapes.
Resumo:
Soil microbial biomass (SMB) plays an important role in nutrient cycling in agroecosystems, and is limited by several factors, such as soil water availability. This study assessed the effects of soil water availability on microbial biomass and its variation over time in the Latossolo Amarelo concrecionário of a secondary forest in eastern Amazonia. The fumigation-extraction method was used to estimate the soil microbial biomass carbon and nitrogen content (SMBC and SMBN). An adaptation of the fumigation-incubation method was used to determine basal respiration (CO2-SMB). The metabolic quotient (qCO2) and ratio of microbial carbon:organic carbon (CMIC:CORG) were calculated based on those results. Soil moisture was generally significantly lower during the dry season and in the control plots. Irrigation raised soil moisture to levels close to those observed during the rainy season, but had no significant effect on SMB. The variables did not vary on a seasonal basis, except for the microbial C/N ratio that suggested the occurrence of seasonal shifts in the structure of the microbial community.
Resumo:
'Good-genes' models of sexual selection predict significant additive genetic variation for fitness-correlated traits within populations to be revealed by phenotypic traits. To test this prediction, we sampled brown trout (Salmo trutta) from their natural spawning place, analysed their carotenoid-based red and melanin-based dark skin colours and tested whether these colours can be used to predict offspring viability. We produced half-sib families by in vitro fertilization, reared the resulting embryos under standardized conditions, released the hatchlings into a streamlet and identified the surviving juveniles 20 months later with microsatellite markers. Embryo viability was revealed by the sires' dark pigmentation: darker males sired more viable offspring. However, the sires' red coloration correlated negatively with embryo survival. Our study demonstrates that genetic variation for fitness-correlated traits is revealed by male colour traits in our study population, but contrary to predictions from other studies, intense red colours do not signal good genes.