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51.
Fisheries management in most areas of the world is concerned with the effects of resource exploitation on the broad marine environment that includes all major ecological components. However, all fisheries lack some information about many of these components particularly marine habitats and non-target species. Such data deficiencies make it difficult to identify priorities for management action. Qualitative ecological risk assessment is one tool that can be used by management to prioritise and evaluate management strategies. This paper demonstrates the mechanics of a qualitative ecological risk assessment applied to a currently operating data deficient commercial fishery. In particular, we demonstrate how the method applies to two distinct ecological components – marine habitats and harvested species – and shows how it contributed to the formation of management responses. The method combines biological and ecological information about each component with knowledge on the operations of the fishery. Using pre-defined decision rules and criteria the available information is used in a rigorous, transparent and repeatable manner. The paper demonstrates that the method can be used generally to apply to all ecological components of a marine fishery where data is deficient.  相似文献   
52.
Surface wettability and topography are recognized as critical factors influencing cell behavior on biomaterials. So far only few works have reported cell responses on surfaces exhibiting extreme wettability in combination with surface topography. The goal of this work is to study whether cell behavior on superhydrophobic surfaces is influenced by surface topography and polymer type. Biomimetic superhydrophobic rough surfaces of polystyrene and poly(L-lactic acid) with different micro/nanotopographies were obtained from smooth surfaces using a simple phase-separation based method. Total protein was quantified and showed a less adsorption of bovine serum albumin onto rough surfaces as compared to smooth surfaces of the same material. The mouse osteoblastic MC3T3-E1 cell line and primary bovine articular chondrocytes were used to study cell attachment and proliferation. Cells attached and proliferate better in the smooth surfaces. The superhydrophobic surfaces allowed cells to adhere but inhibited their proliferation. This study indicates that surface wettability, rather than polymer type or the topography of the superhydrophobic surfaces, is a critical factor in determining cell behavior.  相似文献   
53.
Conspecific negative density dependence in tree species can have major consequences for structuring of communities, yet in temperate forests this phenomenon remains largely unexplored. We investigated density-dependent recruitment in the long-lived conifer yew (Taxus baccata L.), for which low levels of regeneration have been linked with reduced light availability beneath conspecific canopies and speculative autotoxic effects. We combined in situ assessment of yew regeneration in a temperate forest in southwest Ireland with ex situ pot experiments to assess whether light and/or beneath conspecific canopy conditions inhibit the germination and early growth of yew. In field experiments, recruitment was related to distance from adult conspecifics, with higher levels of regeneration found in areas not beneath yew canopies. However, reduced light availability beneath the dense yew canopy was not responsible for this pattern, with abundant seedlings found in areas of equivalent or even lower light availability. Pot experiments showed that seedling survival was highest in deep shade treatments. Experiments also demonstrated that the addition of yew needles negatively affected seedling growth, but not seed germination. Together, our results suggest that under natural forest conditions, the absence of regeneration beneath mature yew canopies, often attributed to low light availability, may at least be partly related to substances in yew canopy or leaf leachates.  相似文献   
54.
In this study, thirteen sponge-derived terpenoids, including five linear furanoterpenes: furospinulosin-1 (1), furospinulosin-2 (2), furospongin-1 (3), furospongin-4 (4), and demethylfurospongin-4 (5); four linear meroterpenes: 2-(hexaprenylmethyl)-2-methylchromenol (6), 4-hydroxy-3-octaprenylbenzoic acid (7), 4-hydroxy-3-tetraprenyl-phenylacetic acid (8), and heptaprenyl-p-quinol (9); a linear triterpene, squalene (10); two spongian-type diterpenes dorisenone D (11) and 11β-acetoxyspongi-12-en-16-one (12); a scalarane-type sesterterpene; 12-epi-deoxoscalarin (13), as well as an indole alkaloid, tryptophol (14) were screened for their in vitro activity against four parasitic protozoa; Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani and Plasmodium falciparum. Cytotoxic potential of the compounds on mammalian cells was also assessed. All compounds were active against T. brucei rhodesiense, with compound 8 being the most potent (IC50 0.60 μg/mL), whereas 9 and 12 were the most active compounds against T. cruzi, with IC50 values around 4 μg/mL. Compound 12 showed the strongest leishmanicidal activity (IC50 0.75 μg/mL), which was comparable to that of miltefosine (IC50 0.20 μg/mL). The best antiplasmodial effect was exerted by compound 11 (IC50 0.43 μg/mL), followed by compounds 7, 10, and 12 with IC50 values around 1 μg/mL. Compounds 9, 11 and 12 exhibited, besides their antiprotozoal activity, also some cytotoxicity, whereas all other compounds had low or no cytotoxicity towards the mammalian cell line. This is the first report of antiprotozoal activity of marine metabolites 1–14, and points out the potential of marine sponges in discovery of new antiprotozoal lead compounds.  相似文献   
55.
The primary objective of this study was to characterize Fusarium spp. associated with the economically devastating mango malformation disease (MMD) in Mexico. In all, 142 Fusarium strains were isolated from symptomatic mango inflorescences and vegetative tissues in eight geographically diverse Mexican states from 2002 through 2007. Initially, all the Mexican isolates were screened for genetic diversity using appolymerase chain reaction and random amplified polymorphic DNA markers and were grouped into seven distinct genotypes. Based on results of these analyses, evolutionary relationships and species limits of the genetically diverse MMD-associated Fusarium spp. were investigated using multilocus DNA sequence data and phylogenetic species recognition. Maximum parsimony analyses of a five-locus data set comprising 5.8 kb of aligned DNA sequence data indicated that at least nine phylogenetically distinct Fusarium spp. within the Gibberella fujikuroi species complex are associated with MMD, including one species within the African clade (Fusarium pseudocircinatum), two species within the Asian clade (F. mangiferae and F. proliferatum), and at least six species within the American clade (F. sterilihyphosum and five undescribed Fusarium spp.). Molecular phylogenetic analyses indicate that a novel genealogically exclusive lineage within the American clade was the predominant MMD associate in Mexico. This new Fusarium sp. caused MMD and could be distinguished from all other known species morphologically by the production of mostly sterile, coiled hyphae which are typically associated with sporodochial conidiophores together with unbranched or sparsely branched aerial conidiophores. Koch's postulates were completed for isolates of the new species on nucellar seedlings of mango cv. Ataulfo. This pathogen is formally described herein as F. mexicanum.  相似文献   
56.
In the Spring of 2009, a veterinarian reported suspected classical swine fever (CSF) on a multiplier pig farm in the southern part of The Netherlands (close to the Belgian border). Over a 5-week period there had been a number of sick sows and an excessively high percentage of stillborn and preterm piglets. Sick animals were treated with anti-inflammatory drugs and antibiotics, but did not respond as well as anticipated. A visiting specialist team from the Food Safety Authority could not exclude CSF as the cause of the clinical problems and sent blood samples to the reference laboratory in Lelystad for a PCR test on CSF antigen. Fortunately, test results obtained 6 hours later were negative for CSF, and the disease control measures were lifted. It later appeared that porcine reproductive and respiratory syndrome (PRRSV) might have been responsible for the problems. But what if CSF had caused the clinical problems? A CSF-transmission model was used to simulate CSF outbreaks dependent on the duration of the high-risk period (HRP). As the duration of the HRP increased, there was an exponential growth in the number of pig farms infected during this period. Simulations also showed that with a longer HRP, the virus spread over greater distances from the source herd. It was also investigated whether a possible CSF outbreak could be detected on the basis of an increased mortality and hence increased number of cadavers sent to a rendering plant. However, the calculated mortality incidence was not sensitive enough to serve as an alarm signal. It is recommended that CSF-exclusion diagnostics be used much earlier in similar clinical situations on pig farms.  相似文献   
57.
58.
A 4.1 kg, 4-month-old female pet rabbit was presented twice within a 4 month period for cranial cruciate ligament rupture of its right, then left stifle joint. Stifle joint stabilization was performed with an extracapsular technique after both events. Immediately after stabilization, the rabbit regained normal use of the injured limbs. The animal underwent a 3 month rehabilitation program intended to increase muscle strength. Twenty-four months after the procedures were performed the rabbit shows no signs of discomfort and has normal use of both rear legs.  相似文献   
59.
The chemical form and content of available nitrogen (N) in salt marsh substrates varies considerably. On the western coast of Ireland, habitats designated as Ombrogenic Atlantic salt marshes were formed on ombrogenic peat substrate. The peat substrate in these systems has three times more ammonium than substrate from adjacent salt marsh habitats on sand and mud substrate. This study examined the extent to which the high concentration of ammonium in peat salt marsh substrate influences the N‐ assimilating enzyme activity of halophytes and the extent to which N metabolism differs between species. Specifically, this work investigated whether plants from peat salt marshes are more likely to assimilate ammonium than plants from non‐peat substrates. Four halophyte plant species—Armeria maritima, Aster tripolium, Plantago maritime, and Triglochin maritime—were sampled from various saltmarsh habitats including three sites on peat substrate and three on non‐peat substrate, comprising sand, mud and sand/mud. The activities of N‐metabolising enzymes—glutamine synthetase (GS), glutamate synthase, glutamate dehydrogenase (GDH), and nitrate reductase (NR)—were quantified in shoot and root parts. Root GS activity in Armeria maritima and shoot GS activity in Triglochin maritima were positively correlated with increasing soil ammonium levels. Root NR activity in Aster tripolium and shoot NR activity in Plantago maritima were significantly higher in plants grown on non‐peat substrates than peat substrates. The shoot : root GS activity ratio in Triglochin maritima on peat substrate was more than double the ratio on non‐peat substrates. It is concluded that all species tested displayed differences in N‐metabolising activities depending on the chemical form and/or concentration of N in the substrate, while three out of the four species were capable of taking advantage of the high levels of ammonium in peat substrates.  相似文献   
60.
The effect of ciclosporin A (CsA) on glucose homeostasis was investigated in 16 dogs with atopic dermatitis by determining plasma glucose, serum fructosamine and insulin concentrations, and serial insulin and glucose concentrations following a glucagon stimulation test, before and 6 weeks after CsA therapy at 5 mg/kg once daily. All dogs completed the study. Following CsA treatment, the median serum fructosamine concentrations were significantly higher (pretreatment 227.5 μmol/L; post-treatment 246.5 μmol/L; P = 0.001; reference range 162-310 μmol/L). Based on analyses of the areas under concentration-time curves (AUC) pre- and post-CsA treatment, plasma glucose concentrations were significantly higher (AUC without baseline correction 31.0 mmol/L/min greater; P = 0.021) and serum insulin concentrations were significantly lower (AUC without baseline correction 217.1 μIU/mL/min lower; P = 0.044) following CsA treatment. Peak glucose concentrations after glucagon stimulation test were significantly higher following CsA treatment (10.75 versus 12.05 mmol/L; P = 0.021), but there was no significant difference in peak serum insulin (52.0 versus 35.0 μIU/mL; P = 0.052). There was a negative correlation between baseline uncorrected insulin AUC and trough serum log CsA concentrations (r = -0.70, P = 0.005). The administration of CsA to dogs with atopic dermatitis leads to disturbances in glucose homeostasis. The clinical significance of this is unclear, but it should be taken into account when considering CsA treatment in dogs that already have such impairments.  相似文献   
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