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1.
Samples of microphytobenthos from the Tagus estuary were analysed for photosynthetic pigments by spectrophotometry and High
Performance Liquid Chromatography (HPLC). Chlorophyll a values obtained with HPLC and spectrophotometry methods presented a highly significant positive correlation for both spectrophotometric
methods used (with and without the correction for pheopigments), but this relationship depended on the type of sediment. We
concluded that spectrophotometric methods give reliable Chl-a values, being suited for routine analysis, when a vast number of replicates is needed. However, for the correct estimation
of pheopigments, HPLC analysis is indispensable. In the literature, Chl-a estimations are expressed per content (μg g−1) or concentration (mg m−2). We discuss the influence of sediment type on the results depending on the type of unit used, and propose a simple conversion
factor based on sediment water content. 相似文献
2.
J. P. Sánchez A. Legarra M. Velasco-Galilea M. Piles A. Sánchez O. Rafel O. González-Rodríguez M. Ballester 《Animal genetics》2020,51(5):799-810
Feed efficiency (FE) is one of the most economically and environmentally relevant traits in the animal production sector. The objective of this study was to gain knowledge about the genetic control of FE in rabbits. To this end, GWASs were conducted for individual growth under two feeding regimes (full feeding and restricted) and FE traits collected from cage groups, using 114 604 autosome SNPs segregating in 438 rabbits. Two different models were implemented: (1) an animal model with a linear regression on each SNP allele for growth trait; and (2) a two-trait animal model, jointly fitting the performance trait and each SNP allele content, for FE traits. This last modeling strategy is a new tool applied to GWAS and allows information to be considered from non-genotyped individuals whose contribution is relevant in the group average traits. A total of 189 SNPs in 17 chromosomal regions were declared to be significantly associated with any of the five analyzed traits at a chromosome-wide level. In 12 of these regions, 20 candidate genes were proposed to explain the variation of the analyzed traits, including genes such as FTO, NDUFAF6 and CEBPA previously associated with growth and FE traits in monogastric species. Candidate genes associated with behavioral patterns were also identified. Overall, our results can be considered as the foundation for future functional research to unravel the actual causal mutations regulating growth and FE in rabbits. 相似文献
3.
Kenza Mokhtar‐Jamaï Rafel Coma Jinliang Wang Frederic Zuberer Jean‐Pierre Féral Didier Aurelle 《Ecology and evolution》2013,3(6):1765-1779
Dispersal and mating features strongly influence the evolutionary dynamics and the spatial genetic structure (SGS) of marine populations. For the first time in a marine invertebrate, we examined individual reproductive success, by conducting larval paternity assignments after a natural spawning event, combined with a small‐scale SGS analysis within a population of the gorgonian Paramuricea clavata. Thirty four percent of the larvae were sired by male colonies surrounding the brooding female colonies, revealing that the bulk of the mating was accomplished by males from outside the studied area. Male success increased with male height and decreased with increasing male to female distance. The parentage analyses, with a strong level of self‐recruitment (25%), unveiled the occurrence of a complex family structure at a small spatial scale, consistent with the limited larval dispersal of this species. However, no evidence of small scale SGS was revealed despite this family structure. Furthermore, temporal genetic structure was not observed, which appears to be related to the rather large effective population size. The low level of inbreeding found suggests a pattern of random mating in this species, which disagrees with expectations that limited larval dispersal should lead to biparental inbreeding. Surface brooding and investment in sexual reproduction in P. clavata contribute to multiple paternity (on average 6.4 fathers were assigned per brood), which enhance genetic diversity of the brood. Several factors may have contributed to the lack of biparental inbreeding in our study such as (i) the lack of sperm limitation at a small scale, (ii) multiple paternity, and (iii) the large effective population size. Thus, our results indicate that limited larval dispersal and complex family structure do not necessarily lead to biparental inbreeding and SGS. In the framework of conservation purposes, our results suggested that colony size, proximity among colonies and the population size should be taken into consideration for restoration projects. 相似文献
4.
Aparicio Enric Rocaspana Rafel Palau-Ibars Antoni de Sostoa Adolfo Alcaraz Carles 《Ichthyological Research》2023,70(1):101-109
Ichthyological Research - The Mediterranean brown trout (Salmo trutta complex) is native to basins draining to the Western Mediterranean Sea, and natural populations are currently declining in... 相似文献
5.
During the development of a given organ, tissue growth and fate specification are simultaneously controlled by the activity of a discrete number of signalling molecules. Here, we report that these two processes are extraordinarily coordinated in the Drosophila wing primordium, which extensively proliferates during larval development to give rise to the dorsal thoracic body wall and the adult wing. The developmental decision between wing and body wall is defined by the opposing activities of two secreted signalling molecules, Wingless and the EGF receptor ligand Vein. Notch signalling is involved in the determination of a variety of cell fates, including growth and cell survival. We present evidence that growth of the wing primordium mediated by the activity of Notch is required for wing fate specification. Our data indicate that tissue size modulates the activity range of the signalling molecules Wingless and Vein. These results highlight a crucial role of Notch in linking proliferation and fate specification in the developing wing primordium. 相似文献
6.
Objective: To assessing the oral hygiene and treatment needs of a geriatric institution in southern France. Background: For various reasons, the care demand from elderly people is low and difficult to determine, whereas their oral status would need long and complicated treatments. Materials and methods: From 2003 to 2004, a cross‐sectional study of 321 elderly patients was conducted at several geriatric services of Montpellier, France. The clinical evaluation of dental status was recorded together with medical information. Dental and prosthetic hygiene, status of dentures, caries experience, dependence conditions and treatment needs were evaluated. Results: The prevalence of edentulism was 27%, with no gender difference (23% of the men and 29% of the women). Among them, 16.7% (upper jaw) and 18.1% (lower jaw) were totally edentulous with no denture. The mean number of decayed and missing teeth was 3.7 for men and 2.8 for women and 21.5 for men and 21.0 for women, respectively. The mean number of filled teeth was 0.8 for men and 1.3 for women, with no statistical difference according to gender for the three indexes. Most of the subjects needed prostheses (53%), 45.1% extractions and 30.6% conservative treatments. Only 2.4% did not need any treatment. Conclusion: The prevalence of edentulism was relatively low, while the need for prosthodontic rehabilitation, especially for men, was still very high. The dental hygiene was globally inadequate. This evaluation emphasises the care demand and the need for help in oral hygiene procedures for the dependent institutionalised elderly. 相似文献
7.
Carlos Fernández-Palomeque Andres Grau Joan Perelló Pilar Sanchis Bernat Isern Rafel M. Prieto Antonia Costa-Bauzá Onofre J. Caldés Oriol Bonnin Ana Garcia-Raja Armando Bethencourt Felix Grases 《PloS one》2015,10(8)
Pathological calcification generally consists of the formation of solid deposits of hydroxyapatite (calcium phosphate) in soft tissues. Supersaturation is the thermodynamic driving force for crystallization, so it is believed that higher blood levels of calcium and phosphate increase the risk of cardiovascular calcification. However several factors can promote or inhibit the natural process of pathological calcification. This cross-sectional study evaluated the relationship between physiological levels of urinary phytate and heart valve calcification in a population of elderly out subjects. A population of 188 elderly subjects (mean age: 68 years) was studied. Valve calcification was measured by echocardiography. Phytate determination was performed from a urine sample and data on blood chemistry, end-systolic volume, concomitant diseases, cardiovascular risk factors, medication usage and food were obtained. The study population was classified in three tertiles according to level of urinary phytate: low (<0.610 μM), intermediate (0.61–1.21 μM), and high (>1.21 μM). Subjects with higher levels of urinary phytate had less mitral annulus calcification and were less likely to have diabetes and hypercholesterolemia. In the multivariate analysis, age, serum phosphorous, leukocytes total count and urinary phytate excretion appeared as independent factors predictive of presence of mitral annulus calcification. There was an inverse correlation between urinary phytate content and mitral annulus calcification in our population of elderly out subjects. These results suggest that consumption of phytate-rich foods may help to prevent cardiovascular calcification evolution. 相似文献
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9.
Laura Alonso-Sáez Evaristo Vázquez-Domínguez Clara Cardelús Jarone Pinhassi M. Montserrat Sala Itziar Lekunberri Vanessa Balagué Maria Vila-Costa Fernando Unrein Ramon Massana Rafel Simó Josep M. Gasol 《Ecosystems》2008,11(3):397-409
Data from several years of monthly samplings are combined with a 1-year detailed study of carbon flux through bacteria at
a NW Mediterranean coastal site to delineate the bacterial role in carbon use and to assess whether environmental factors
or bacterial assemblage composition affected the in situ rates of bacterial carbon processing. Leucine (Leu) uptake rates
[as an estimate of bacterial heterotrophic production (BHP)] showed high interannual variability but, on average, lower values
were found in winter (around 50 pM Leu−1 h−1) as compared to summer (around 150 pM Leu−1 h−1). Leu-to-carbon conversion factors ranged from 0.9 to 3.6 kgC mol Leu−1, with generally higher values in winter. Leu uptake was only weakly correlated to temperature, and over a full-year cycle
(in 2003), Leu uptake peaked concomitantly with winter chlorophyll a (Chl a) maxima, and in periods of high ectoenzyme activities in spring and summer. This suggests that both low molecular weight
dissolved organic matter (DOM) released by phytoplankton, and high molecular weight DOM in periods of low Chl a, can enhance BHP. Bacterial respiration (BR, range 7–48 μg C l−1 d−1) was not correlated to BHP or temperature, but was significantly correlated to DOC concentration. Total bacterial carbon
demand (BHP plus BR) was only met by dissolved organic carbon produced by phytoplankton during the winter period. We measured
bacterial growth efficiencies by the short-term and the long-term methods and they ranged from 3 to 42%, increasing during
the phytoplankton blooms in winter (during the Chl a peaks), and in spring. Changes in bacterioplankton assemblage structure (as depicted by denaturing gradient gel electrophoresis
fingerprinting) were not coupled to changes in ecosystem functioning, at least in bacterial carbon use. 相似文献
10.
Clara Ruiz-González Martí Galí Eva Sintes Gerhard J. Herndl Josep M. Gasol Rafel Simó 《PloS one》2012,7(9)
Even though the uptake and assimilation of organic compounds by phytoplankton has been long recognized, very little is still known about its potential ecological role in natural marine communities and whether it varies depending on the light regimes the algae experience. We combined measurements of size-fractionated assimilation of trace additions of 3H-leucine and 35S-dimethylsulfoniopropionate (DMSP) with microautoradiography to assess the extent and relevance of osmoheterotrophy in summer phytoplankton assemblages from Arctic and Antarctic waters, and the role of solar radiation on it was further investigated by exposing samples to different radiation spectra. Significant assimilation of both substrates occurred in the size fraction containing most phytoplankton (>5 µm), sunlight exposure generally increasing 35S-DMSP-sulfur assimilation and decreasing 3H-leucine assimilation. Microautoradiography revealed that the capacity to take up both organic substrates seemed widespread among different polar algal phyla, particularly in pennate and centric diatoms, and photosynthetic dinoflagellates. Image analysis of the microautoradiograms showed for the first time interspecific variability in the uptakes of 35S-DMSP and 3H-leucine by phytoplankton depending on the solar spectrum. Overall, these results suggest that the role of polar phytoplankton in the utilization of labile dissolved organic matter may be significant under certain conditions and further confirm the relevance of solar radiation in regulating heterotrophy in the pelagic ocean. 相似文献