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991.
Bivalve aquaculture has become increasingly important for marine protein production and is an alternative to exploiting natural resources. Its further and sustainable development should follow an ecosystem approach, to maintain both biodiversity and ecosystem functioning. The identification of critical thresholds to development remains difficult. The present work aims at combining the calculation of the system’s ecological carrying capacity (ECC) with the ecosystem view of resilience for a bay system exposed to bivalve (scallop) aquaculture. Using a trophic food-web model, a stepwise further expansion of culture activities was simulated, and the impact on the system was evaluated twofold: First, a recently developed approach to estimating ECC was used, and second, a resilience indicator was calculated, which is based on the distribution of consumption flows within the trophic network (sensu Arreguín-Sanchez in Ecol Model 272: 27–276, 2014). Results suggest that a culture expansion beyond present-day scale would (a) cause a shift in community composition towards a system dominated by secondary consumers, (b) lead to the loss of system compartments, affecting ecosystem functioning, and (c) result in a decrease in resilience, emphasizing the need to regulate aquaculture activities. The applicability and potential of this presented method in the context of an ecosystem-based approach to aquaculture is discussed. This work aims at adding to the ongoing discussion on sustainable bivalve aquaculture and is expected to help guide aquaculture management. 相似文献
992.
Reza A. Niles Charles R. Thickstun Horace Cox Daniel Dilliott Clara R. Burgert-Brucker Emma M. Harding-Esch Nikita Clementson Annastacia Sampson Jean Seme Alexandre Ana C. Morice Trejos Ronaldo G. Carvalho Scholte Alison Krentel 《PLoS neglected tropical diseases》2021,15(9)
BackgroundGuyana is one of four countries in the Latin American Region where lymphatic filariasis (LF) remains endemic. In preparation for the introduction of a new triple drug therapy regimen (ivermectin, diethylcarbamazine, and albendazole (IDA)) in 2019, an acceptability study was embedded within sentinel site mapping in four regions to assess mass drug administration (MDA) coverage and compliance, acceptability, and perceptions about treatment and disease. The results from this survey would inform the rollout of IDA in Guyana in 2019.MethodsData collection for the study occurred in August 2019, using a validated questionnaire administered by trained enumerators. Across all regions, a total of 1,248 participants were sampled by the Filarial Mapping team. Four-hundred and fifty-one participants aged over 18 years were randomly selected for participation in an expanded acceptability questionnaire. All data were captured in Secure Data Kit (SDK).ResultsAcceptability was measured using a mean acceptability score. Unadjusted mean scores ranged from 24.6 to 29.3, with 22.5 as the threshold of acceptability. Regional variation occurred across many indicators of interest: self-rated understanding about LF, mechanisms of LF transmission, LF drug safety and history of treatment during MDA. Region IV (Georgetown) recorded higher knowledge about LF, but lower compliance and acceptability. Number of pills was not perceived as a concern.ConclusionAcceptability of MDA was good across all four regions under study. Results from this study set a baseline level for key indicators and acceptability, from which the acceptability of IDA can be measured. Regional variations across indicators suggest that localized approaches should be considered for social mobilization and MDA delivery to capture these contextual differences. 相似文献
993.
Sarah L. Dodd Elke Lieckfeldt Priscila Chaverri Barrie E. Overton Gary J. Samuels 《Mycological Progress》2002,1(4):409-428
Hypocrea patella is reevaluated. Its Trichoderma anamorph is described and the phylogenetic position of the species is determined through sequences of the ITS regions of
rDNA. It is sister to a clade that includes Trichoderma longibrachiatum/H. schweinitzii. Hypocrea patella f. tropica is accepted for a Costa Rican collection. Hypocrea neorufa and its Trichoderma anamorph are described. Its phylogenetic position is determined by sequences of the ITS region of rDNA and the protein-coding
translation-elongation factor (EF-1α). It is derived from within a clade that includes T. viride/H. rufa, T. atroviride/H. atroviridis, T. koningii/H. koningii and T. asperellum.
Deceased August 2002. 相似文献
994.
A multivariate search for pollination syndromes among penstemons 总被引:4,自引:0,他引:4
Paul Wilson Maria Clara Castellanos James N. Hogue James D. Thomson W. Scott Armbruster 《Oikos》2004,104(2):345-361
The seeming ubiquity of spatio-temporal variation in pollination regime suggests that flowers ought to be adapted to a wide range of pollinators, yet many comparative biologists perceive that in groups with complex flowers there is considerable specialization onto pollination syndromes. Statistical documentation of such syndromes has been presented for very few groups of flowers. Accordingly, we measured, for 49 species of Penstemon and close relatives, both the morphology of the flowers and visitation by pollinators. We describe the mechanics of pollination for representative species. Ordinations show a distinct difference between hummingbird-pollinated species and hymenopteran-pollinated species. Flower color is particularly good at separating hummingbird- from hymenopteran-flowers. Other characters are also correlated with this dichotomy. Within the hymenopteran-pollinated species, there are additional relationships between floral morphology and the size of the principal pollinators. Flowers frequented by large bees, such as Xylocopa , have large open vestibules and relatively short floral tubes. Flowers frequented by smaller bees, such as Osmia , have long narrow floral tubes. Unlike nectar-collecting bees, pollen-collecting bees tend to be attracted to flowers of the hummingbird syndrome. The overarching pattern was that syndrome characterizations were successful at predicting pollination by hummingbirds versus Hymenoptera, two types of animals that are profoundly different, but less successful at predicting visitation by one kind of bee versus another. 相似文献
995.
Riccardo Sarzani Pasquale Strazzullo Fabio Salvi Roberto Iacone Francesca Pietrucci Alfonso Siani Gianvincenzo Barba Maria Clara Gerardi Paolo Dessì‐Fulgheri Alessandro Rappelli 《Obesity (Silver Spring, Md.)》2004,12(2):351-356
Objective: To test the association of the C(?55)A polymorphism of the natriuretic peptide clearance receptor (NPRC) with blood pressure (BP), overweight/obesity, and body fat distribution in a large male adult population. Research Methods and Procedures: The study population was from a cross‐sectional and follow‐up study of 787 untreated male participants in the 1994 to 1995 follow‐up examination of the Olivetti Heart Study in Naples (356 of whom were examined previously in 1975). BP and anthropometric measures were taken, and biochemical assays were performed. The NPRC gene polymorphism C(?55)A was evaluated by polymerase chain reaction and HgaI digestion. Results: In the whole study population, there was no difference in BP, BMI, and biochemical tests among genotypes. Considering an A(?55) recessive model of inheritance, the AA subjects had lower BMI and waist circumference and lower prevalence of overweight, obesity, and abdominal adiposity as compared with the CC+CA subjects. On reviewing the characteristics of the subgroup previously examined in 1975, the AA subjects had already lower BMI, and their 20‐year rate of overweight and obesity was lower than the CC+CA subjects; no difference was observed in the rate of hypertension. Discussion: Male subjects carrying the A(?55)A NPRC genotype had a significantly lower prevalence of overweight, obesity, and abdominal adiposity. They also had a lower 20‐year rate of overweight compared with CC+CA individuals. These findings from a large unselected and untreated male population are in keeping with the recent evidence of a powerful lipolytic and lipomobilizing activity of natriuretic peptides. 相似文献
996.
Rosario Gonzlez-Muiz Mercedes Martín-Martínez Cesare Granata Eliandre de Oliveira Clara M. Santiveri Carlos Gonzlez Diana Frechilla Rosario Herranz M. Teresa García-Lpez Joaquín Del Río M. Angeles Jimnez David Andreu 《Bioorganic & medicinal chemistry》2001,9(12):3173-3183
To probe the importance of a proposed β-turn within residues S9-R12 of PACAP for recognition by VIP/PACAP receptors, compounds 1 and 2, two conformationally restricted analogues of PACAP27 incorporating respectively (S)- or (R)-IBTM as type II or II′ β-turn dipeptide mimetic at the Y10-S11 position, were synthesized. According to 1H NMR conformational analyses in aqueous solution and 30% TFE, both PACAP27 and the [S-IBTM10,11]PACAP27 analogue 1 adopt similar ordered structures. PACAP27 shows an N-terminal disordered region (residues H1-F6) and an -helical conformation within segment T7–L27. For residues S9–R12, our data seem more compatible with a segment of the -helix than with the β-turn previously proposed for this fragment. In compound 1 the -helix, also spanning T7–L27 residues, appears slightly distorted at the N-terminus relative to the native peptide. Although this distortion could lead to the marked decrease in binding affinity of this compound at the VIP/PACAP receptors, the lack of the Y10 side chain in analogues 1 and 2 could also significantly affect the binding of these compounds. 相似文献
997.
Studies were carried out on the air and on Carraramarble blocks located in the terrace of MessinaMuseum, in order to know the likelihood of airbornefungal spores coming into contact with and colonisingtridimensional objects. Our results showed there were not significantdifferences between airborne fungi circulating inspring and in autumn; Aspergillus, Penicillium,Fusarium, Alternaria, Cladosporium,Ulocladium, Aureobasidium, Phoma were themost common isolates. However, only few species wereable to settle on the marble surfaces as demonstratedby their isolation after 2 and 6 years of exposition. 相似文献
998.
999.
Rodrigues-Ferreira C da Silva AP Galina A 《Journal of bioenergetics and biomembranes》2012,44(1):39-49
The alkylating agent 3-Bromopyruvate (3-BrPA) has been used as an anti-tumoral drug due to its anti-proliferative property
in hepatomas cells. This propriety is believed to disturb glycolysis and respiration, which leads to a decreased rate of ATP
synthesis. In this study, we evaluated the effects of the alkylating agent 3-BrPA on the respiratory states and the metabolic
steps of the mitochondria of mice liver, brain and in human hepatocarcinoma cell line HepG2. The mitochondrial membrane potential
(ΔΨm), O2 consumption and dehydrogenase activities were rapidly dissipated/or inhibited by 3-BrPA in respiration medium containing
ADP and succinate as respiratory substrate. 3-BrPA inhibition was reverted by reduced glutathione (GSH). Respiration induced
by yeast soluble hexokinase (HK) was rapidly inhibited by 3-BrPA. Similar results were observed using mice brain mitochondria
that present HK naturally bound to the outer mitochondrial membrane. When the adenine nucleotide transporter (ANT) was blocked
by the carboxyatractiloside, the 3-BrPA effect was significantly delayed. In permeabilized human hepatoma HepG2 cells that
present HK type II bound to mitochondria (mt-HK II), the inhibiting effect occurred faster when the endogenous HK activity
was activated by 2-deoxyglucose (2-DOG). Inhibition of mt-HK II by glucose-6-phosphate retards the mitochondria to react with
3-BrPA. The HK activities recovered in HepG2 cells treated or not with 3-BrPA were practically the same. These results suggest
that mitochondrially bound HK supporting the ADP/ATP exchange activity levels facilitates the 3-BrPA inhibition reaction in
tumors mitochondria by a proton motive force-dependent dynamic equilibrium between sensitive and less sensitive SDH in the
electron transport system. 相似文献
1000.
A fingerprinting technique similar to repetitive extragenic palindromic PCR was developed to identify strains of Lactococcus lactis. The method distinguishes closely related strains and discriminates among some with identical ldh sequences. The fingerprinting primer LL-Rep1 complements a moderately repeated sequence found in low G+C Gram-positive bacteria and may therefore prove useful for discriminating among strains of other low G+C Gram-positive species. 相似文献