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691.
Gotzon Basterretxea Ignacio A. Catalán Antoni Jordi Itziar Álvarez Miquel Palmer Ana Sabatés 《Fisheries Oceanography》2013,22(6):477-495
The factors that regulate the self‐recruitment of fish larvae were explored in Cabrera National Park (CNP), an insular Marine Protected Area (MPA) located off southern Mallorca (Western Mediterranean). Our study attributes the regulation of larval arrival to the MPA to a combination of retention by topographically generated circulation patterns around the island and shelf break frontal dynamics. Specifically, within the shelf, interaction of the wind‐induced oscillatory flow with the island was shown to generate ephemeral recirculation patterns that, over time, favor larval retention in the proximity of the MPA. According to our measurements, oscillatory flows produced by wind‐forced island‐trapped waves (ITWs) dominate the flow around CNP. ITW‐forced dispersion simulations were in agreement with the observed distributions of several typical fish species that breed in the CNP. A second regulator of environmental variability is the influence of boundary currents and open ocean mesoscale structures at the shelf break. These structures generate frontal zones that are comparatively more long‐lived than inner‐shelf circulation patterns, and they were shown to act as barriers to the offshore dispersion of coastal fish larval assemblages. Finally, inferences from larval size distributions around the MPA together with particle‐tracking model simulations suggested the relevance of behavioral processes for larval recruitment to the MPA. Based on these observations, the waters around the CNP can be viewed as a relatively stable system that allows breeding fish populations to rely on self‐recruitment for their long‐term persistence, independent of other source populations along the coast of Mallorca. 相似文献
692.
693.
Pepijn PrinsenAna Gutiérrez Jorge RencoretLidia Nieto Jesús Jiménez-BarberoAuphélia Burnet Michel Petit-ConilJorge L. Colodette Ángel T. MartínezJosé C. del Río 《Industrial Crops and Products》2012,36(1):572-583
The morphological and chemical characteristics of the woods from several eucalypt hybrids from the Brazilian Genolyptus program were studied. The hybrids selected for this study were Eucalyptus grandis × E. urophylla (IP), E. urophylla × E. urophylla (U1 × U2), E. grandis × [E. urophylla × E. globulus] (G1 × UGL), and [E. dunnii × E. grandis] × E. urophylla (DG × U2). The analyses of the lipophilic extractives indicated a similar composition in all eucalypt hybrids, which were dominated by sitosterol, sitosterol esters and sitosteryl 3β-d-glucopyranoside. These compounds are responsible for pitch deposition during kraft pulping of eucalypt wood. Some quantitative differences were found in the abundances of different lipid classes, the wood from U1 × U2 having the lowest amounts of these pitch-forming compounds. The chemical composition and structure of lignins were characterized by Py-GC/MS and 2D-NMR that confirmed the predominance of syringyl over guaiacyl units and only showed traces of p-hydroxyphenyl units in all the woods, with the highest S/G ratio for G1 × UGL. The 2D-NMR spectra gave additional information about the inter-unit linkages in the lignin polymer. All the lignins showed a predominance of β-O-4′ ether linkages (75-79% of total side-chains), followed by β-β′ resinol-type linkages (9-11%) and lower amounts of β-5′ phenylcoumaran-type, β-1′ spirodienone-type linkages or β-1′ open substructures. The lignin from the hybrid G1 × UGL presented also the highest proportion of β-O-4′ linkages, and therefore, it is foreseen that the wood from this hybrid will be more easily delignifiable than the other selected Brazilian eucalypt hybrids. In complement to these chemical analyses, the morphological characterization of fibers, vessels and fines revealed that hybrid eucalypt clone DG × U2 presented the most interesting properties for the manufacture of paper pulps and biofuels. 相似文献
694.
Elba Ver?nica Matoso Maciel Carvalho Rosiely Félix Bezerra Ranilson de Souza Bezerra Janete Magali de Araújo Athiê Jorge Guerra Santos Maria Tereza dos Santos Correia Luana Cassandra Breitenbach Barroso Coelho 《Fisheries Science》2012,78(4):879-887
Tambaqui Colossoma macropomum is the most important Amazonian native species in South American aquaculture. Innate immunity at least partially depends on the recognition of pathogen-associated molecular patterns by receptor-recognizing pathogens (PRRs). Some PRRs have been characterized in fishes, and several studies have focused on the role of lectins in the immune system of various fishes. Lectins are proteins that specifically recognize carbohydrates and which have important biological functions. Tambaqui serum lectin (ComaSeL), which was identified on the basis of its hemagglutinating activity, was pre-purified, biochemically characterized, and used in assays of antibacterial activity against pathogenic bacteria in freshwater fishes. A study of the seasonality of this lectin was performed. Comasel activity was stable at a pH between 4.0 and 9.0 and lost 100?% of its activity at 70?°C. It recognized the carbohydrates d-galactose, 1-O-methyl-d-galactopyranoside, and d-fucose, showing antibacterial activity for Gram-negative bacteria. Its activity showed significant differences between the summer and winter (p?<?0.05, Tukey test), thereby corroborating observations that tambaqui becomes more susceptible to mortality from diseases caused by bacteria and fungi during the winter. With this information, new tools may be developed for gaining a better understanding of the role of these proteins in the immune system of the tambaqui, ultimately resulting in the improved management of this fish by pisciculturists. 相似文献
695.
PENN LLOYD ÉVA E. PLAGÁNYI SCARLA J. WEEKS MARITES MAGNO‐CANTO GYULA PLAGÁNYI 《Fisheries Oceanography》2012,21(1):78-94
The impacts of ocean warming resulting from recent climate change on the abundance patterns of marine species have been well documented in temperate seas of the northern hemisphere, but the impacts of a widening tropical belt are largely unexplored. Using measurements of sea surface temperature and spear‐fishing records for 84 species spanning a 19‐yr period, we examined the effects of ocean warming on a sub‐tropical reef‐fish community on the southeastern coast of Africa. Corresponding with a 0.46°C increase in average sea surface temperature between the time periods 1989–97 and 2002–2007, the ratio of species showing an overall decrease/ no change/increase in abundance was 1 : 3 : 2 among six species at the northern limits of their distribution in the region (temperate species), 1 : 15 : 6 among 22 broadly distributed species, and 1 : 5 : 9 among 15 species at the southern limits of their distribution (tropical species). Also, the relative abundance of temperate species as a whole decreased by 10–13% whereas that of tropical species increased by 9%, and broadly distributed species showed little change. Average species richness and diversity increased 33 and 15% respectively between the two time periods. These results are broadly consistent with a predicted poleward shift in species ranges and a predicted increase in species richness and diversity with increasing sea temperature. Our findings confirm that large‐scale climate change causing a widening of the tropical belt and subsequent ocean warming is having a profound impact on marine species abundance patterns and community composition at a local scale in the sub‐tropics. 相似文献
696.
Fabrizio Costa Luca Cappellin Sara Longhi Walter Guerra Pierluigi Magnago Duilio Porro Christos Soukoulis Silvio Salvi Riccardo Velasco Franco Biasioli Flavia Gasperi 《Postharvest Biology and Technology》2011,61(1):21-28
Texture of apple fruit originates from anatomic traits related to cell wall architecture and is one of its most important quality characteristics, thus there is the desire to better understand the different factors which contribute to apple texture. Here we present a novel approach based on the simultaneous profiling of the mechanical and acoustic response of the flesh tissue to compression, using a texture analyzer coupled with an acoustic device. The methodology was applied to a 86 different apple cultivars, measured after two months postharvest cold storage and characterised by 16 acoustic and mechanical parameters. Statistical treatment of the data with principal component analysis (PCA) allowed for the identification of three groups of variables, the mechanical ones being clearly distinguished from the acoustic ones. Moreover, the distribution of the apple cultivars in the multivariate PCA plot allowed characterisation of the cultivars according to their textural performance. Each cultivar was analyzed also with non-destructive vis/NIR spectroscopy in order to determine impartially the ripening stage. Sensory evaluation by panellists was performed on a selected group of cultivars and sensory data correlated with the acoustic-mechanical data. The results demonstrate the good performance of our combined acoustic-mechanical strategy in measuring apple crispness as it is perceived by human senses. 相似文献
697.
This paper analyses the patterns of firm growth of manufacturing firms across Portuguese regions. In particular, we compare firm size and growth in order to investigate 1) whether region‐specific characteristics, interpreted as generating localization economies, exert any influence on firm growth and size, and 2) whether there is evidence of persistence in firm growth across regions. Using an extensive dataset of Portuguese manufacturing firms and applying parametric and semi‐parametric approaches, we found that, in eleven of the eighteen analyzed regions, firm growth is related to firm size and therefore firms have no equal probabilities of attaining a particular growth rate within any given period. Moreover, the results uncovered that firms experience serial correlation in their growth patterns in all regions and region‐specific characteristics, such as industrial diversity, entrepreneurship potential, and workforce qualities, engender differences in the way firms grow. Thus, this paper adds to the literature by showing how geographic location matters to firm size and growth. 相似文献
698.
Àngel Fernández i Martí Toshio Hanada José M. Alonso Hisayo Yamane Ryutaro Tao Rafel Socias i Company 《Scientia Horticulturae》2010
Since self-compatibility has become the primary objective of most almond breeding programmes, search for new self-compatibility sources has acquired a great importance in almond research. The local Spanish cultivar ‘Vivot’, identified as showing the genotype S23Sf, thus presumably self-compatible, was found to be unexpectedly self-incompatible in spite of the presence of the Sf allele, as also observed in other almond cultivars. However, not only the coding sequences of both the Sf-RNase and the SFBf of ‘Vivot’ and ‘Blanquerna’, a confirmed self-compatible cultivar, were identical, but also the 5′ regulatory sequence of the Sf-RNase of both. Thus, the reason for the different expression of the Sf is independent of the complete genetic identity found in the whole chromosome region bordering the S-locus in the almond cultivars sharing the Sf allele. 相似文献
699.
Ángela Taboada Reyes Tárrega Leonor Calvo Elena Marcos José Antonio Marcos José María Salgado 《European Journal of Forest Research》2010,129(1):31-45
The aim of this study was to evaluate the influence of forest structure (mainly resulting from human uses) and forest type (the identity of the dominant tree species) on biodiversity. We determined the diversity of two taxonomical groups: the understory vegetation and the edaphic carabid beetle fauna. We selected eight types of forest ecosystems (five replicates or stands per forest type): pine (Pinus sylvestris) plantations of three age classes (10, 40 and 80 years since reforestation), an old-growth relict natural pine forest, and four types of oak (Quercus pyrenaica) stands: mature forests with livestock grazing and firewood extraction, mature forests where uses have been abandoned, “dehesa” ecosystems and shrubby oak ecosystems. The results obtained by a global PCA analysis indicated that both tree size and dominant species influenced the ordination of the 40 forest stands. In general, carabids were more sensitive to changes in forest heterogeneity and responded more clearly to the analysed structural variables than the understory vegetation, although the species richness of both groups was significantly correlated and higher in case of oak forests. Pine forest ecosystems were characterised by the lowest species richness for both taxonomical groups, the lowest plant diversity and by the lowest coefficients of variation and, consequently, low structural heterogeneity. As a result, it was very difficult to discriminate the effects of the spatial heterogeneity and the dominant tree species on biodiversity. 相似文献
700.
I. Aranda-Ávila J. Herrera-Camacho J. R. Aké-López R. A. Delgado-León J. C. Ku-Vera 《Tropical animal health and production》2010,42(7):1435-1440
The aim was to evaluate the effect of corn oil supplementation during postpartum anoestrus on ovarian activity, pregnancy
rate, progesterone (P4), and lipid metabolites (cholesterol, CHO; low and high density lipoproteins; LDL and HDL, respectively) concentrations in
blood of F1 (Bos taurus × Bos indicus) grazing cows. Cows were randomly assigned to an experimental group, fed with a supplement containing 4% corn oil on dry
matter basis (OG, n = 11), and a control group with the same supplement without corn oil (CG, n = 12). Both supplements contained equivalent amounts of crude protein and metabolizable energy and were fed for 34 days continuously.
All cows were induced to estrous 12 days after beginning of supplementation by using a synthetic progestagen and artificially
inseminated 56 h after retiring the implants. Pregnancy diagnosis was performed by transrectal palpation 45 days after insemination,
evaluating simultaneously ovarian activity. P4 and lipid metabolites (CHO, HDL, LDL) concentrations were determined in blood samples collected at 3-day intervals, from
the beginning of corn oil supplementation and up to 10 days after artificial insemination. Ovarian activity was affected by
treatment (p < 0.05), finding ovarian structures in 72.7% of OG cows and in 50% of CG cows. Concentration of P4 and CHO was higher for OG with respect to CG (2.52 ± 0.65 vs 1.88 ± 0.62 ng/ml and 117.79 ± 11.57 vs 85.71 ± 12.11 mg/dl,
respectively), whereas pregnancy rate and blood concentrations of HDL and LDL were not affected by treatment (p > 0.05). Addition of corn oil to the supplement stimulated ovarian activity and increased serum concentrations of progesterone
and cholesterol in grazing B. taurus × B. indicus cows with low body condition score showing postpartum anoestrus. 相似文献