Integral Management Zones: A novel strategy for marine bivalve production in the Gulf of California,Mexico     

Gaspar Soria  Francisco J. Fernández-Rivera Melo  Virginia Mailen Tortolini  Ana Cinti  Raziel Hernández-Pimienta  Lorena Rocha-Tejeda  Silvio Guido Marinone  Adrian Munguia-Vega 《水产资源保护:海洋与淡水生态系统》2024,34(1):e4065

Selection for Fungicide Resistance Within a Growing Season in Field Populations of Phytophthora infestans at the Center of Origin     

Grünwald NJ  Sturbaum AK  Montes GR  Serrano EG  Lozoya-Saldaña H  Fry WE 《Phytopathology》2006,96(12):1397-1403

ABSTRACT The central highlands of Mexico should provide an optimal testing ground for evaluating the potential threat of selection for resistance to fungicides in the population of Phytophthora infestans. We evaluated the hypotheses that exposure to the fungicides azoxystrobin, cymoxanil, dimethomorph, fluazinam, mancozeb, metalaxyl, and propamocarb hydrochloride would lead to (i) a shift in the sensitivity distributions (i.e., selection) and (ii) a lower genotypic diversity of the population. We compared populations from unsprayed plots with populations that had been exposed to several applications of each of the fungicides within a single field season. This study provides novel baseline data and shows that the Toluca valley P. infestans population has a wide range of sensitivities to the fungicides fluazinam, cymoxanil, dimethomorph, metalaxyl, and propamocarb. Directional selection toward resistance combined with a reduction in genetic diversity of the P. infestans population was observed only for the fungicide metalaxyl. The results obtained provide direct experimental support for continuing vigilance regarding further introductions of exotic strains of P. infestans into the United States.  相似文献   

Benthic dynamics within a land-based semi-intensive aquaculture fish farm: the importance of settlement ponds     

Susana Carvalho  Manuela Falcão  João Cúrdia  Ana Moura  Dalila Serpa  Miguel B. Gaspar  Maria Teresa Dinis  Pedro Pousão-Ferreira  Luís Cancela da Fonseca 《Aquaculture International》2009,17(6):571-587

The present work aims to assess the importance of settlement ponds (SP) in semi-intensive fish farms by studying benthic dynamics in an aquaculture fish farm, more specifically in the water reservoir (WR) and SP and also in production (P) and nonproduction (C) ponds during a 16-month period. In Portugal, a SP is only mandatory for intensive fish farms, and another objective of the present study is to assess the importance of these areas in semi-intensive fish farms. The WR was the area with highest diversity and evenness, as well as the higher number of exclusive taxa and taxa sensitive to organic enrichment. P and SP samples showed signs of higher disturbance levels, emphasized namely by the association of the opportunistic annelids Capitella spp. and Tubificidae. However, the benthic data from SP points to lower disturbance levels than P both due to an increase in the percentage of sensitive taxa observed in June and October 2004 and by the association of this latter sample with water reservoir samples as evidenced by canonical correspondence analysis. Moreover, a higher and increasing number of taxa when compared with the P area were also observed. Therefore, in semi-intensive fish farms, where effluents from P ponds are directly discharged to the lagoon, the potential environmental impacts would be more severe. In conclusion, the imposition of SP in semi-intensive fish farms should be considered, especially because most fish farms are located within relevant wetland areas.  相似文献   

Productivity change of the artisanal fishing fleet in Portugal: A Malmquist index analysis     

M.M. Oliveira  M.B. Gaspar  J.P. Paixão  A.S. Camanho 《Fisheries Research》2009,95(2-3):189-197

This paper explores the evolution of productivity of the artisanal dredge fleet that operates in the south coast of Portugal. This fleet is considered to be one of the most significant in the sector, essentially due to the volume and value of its catches. In this context, the study carried out sought in first place to determine variation in productivity over a time window of 10 years (between 1995 and 2004). Secondly, it sought to distinguish the performance of local and coastal vessels comprising the chosen fleet. The performance of the five homeports in the Algarve coast was also compared. We used Malmquist indexes to measure productivity change and explored the impact of changes in stock conditions and in regulatory policies on productivity levels. During the time period analysed, the measures defined by regulatory entities included allowing the use of a new type of dredge and the establishment of fishing quotas per vessel and per species. Finally, the fishing quotas allowed for each vessel were confronted with the captures officially declared.  相似文献   

Anti-Hepatocellular Carcinoma (HepG2) Activities of Monoterpene Hydroxy Lactones Isolated from the Marine Microalga Tisochrysis Lutea     

Katkam N. Gangadhar  Maria Joo Rodrigues  Hugo Pereira  Helena Gaspar  F. Xavier Malcata  Luísa Barreira  Joo Varela 《Marine drugs》2020,18(11)

Tisochrysis lutea is a marine haptophyte rich in omega-3 polyunsaturated fatty acids (e.g., docosahexaenoic acid (DHA)) and carotenoids (e.g., fucoxanthin). Because of the nutraceutical applications of these compounds, this microalga is being used in aquaculture to feed oyster and shrimp larvae. In our earlier report, T. lutea organic crude extracts exhibited in vitro cytotoxic activity against human hepatocarcinoma (HepG2) cells. However, so far, the compound(s) accountable for the observed bioactivity have not been identified. Therefore, the aim of this study was to isolate and identify the chemical component(s) responsible for the bioactivity observed. Bioassay-guided fractionation through a combination of silica-gel column chromatography, followed by preparative thin layer chromatography (PTLC), led to the isolation of two diastereomers of a monoterpenoid lactone, namely, loliolide (1) and epi-loliolide (2), isolated for the first time in this species. The structural elucidation of both compounds was carried out by GC-MS and 1D (¹H and ¹³C APT) and 2D (COSY, HMBC, HSQC-ed, and NOESY) NMR analysis. Both compounds significantly reduced the viability of HepG2 cells and were considerably less toxic towards a non-tumoral murine stromal (S17) cell line, although epi-loliolide was found to be more active than loliolide.  相似文献   

EFFECT OF RATION AND SIZE HETEROGENEITY ON HARVEST TIME: TILAPIA CULTURE IN YUCATAN,MEXICO     

Roger Domínguez-May  Juan M. Hernández  Eucario Gasca-Leyva  Gaspar R. Poot-López 《Aquaculture Economics & Management (Blackwell Science)》2013,17(4):278-301

Size heterogeneity is a common phenomenon in aquaculture systems and influences final production and economic yield. Among other factors, this variability is determined by ration. These variables directly affect potential returns and therefore influence the recommendations made for optimum aquaculture system management. As part of the search for more profitable culture strategies, a bioeconomic model was developed to analyze the effect of size heterogeneity and ration on optimum harvest time and size, thus creating a new methodological tool. Size dispersion was included using a continuous, size-structured population model incorporating the effect of ration on growth. Theoretical results were applied in a case study of tilapia culture in Yucatan State, Mexico, in which optimum ration levels and harvest times clearly differed between size heterogeneity and homogeneity models. Case study results indicated the use of different recommended ration and harvest management strategies depending on real and/or potential target market.  相似文献   

Input management in integrated agriculture-aquaculture systems in Yucatan: Tree spinach leaves as a dietary supplement in tilapia culture     

Gaspar Román Poot-López  Juan M. Hernández 《Agricultural Systems》2010,103(2):98-104

Integrated agricultural-aquaculture (IAA) systems involving tilapia culture have been promoted in Yucatan State, Mexico, as a way of producing fish protein and providing additional economic returns in poor rural areas. System productivity is sub-optimal due to lack of management skills, balanced feed (30% protein-content tilapia feed) shortages and deficient technical assistance. To overcome resource limitations, producers complement balanced feed with the leaves of tree spinach (Cnidoscolus chayamansa), a plant found in Yucatan, other parts of Mexico, Central and South America, Africa, Asia and Oceania. Based on experimental data, a bioeconomic analysis was made to determine (1) the combination of balanced feed and tree spinach leaves which minimizes production costs and (2) the combination which maximizes economic returns. In a limited-resource scenario, a combination of 50% balanced feed at manufacturer-recommended ration plus tree spinach ad libitum reduced feeding costs and increased producer economic returns by 37.9% vs. a complete balanced feed diet, 48.4% vs. a half-complete diet, and 98.3% vs. satiety rations. Use of tree spinach leaves in tilapia diets as a part of IAA systems in Yucatan greatly improved feed management efficiency and the results suggest that this feed input may be used for the same purpose in other regions where it is grown.  相似文献   

Substitution of Balanced Feed with Chaya,Cnidoscolus chayamansa,Leaf in Tilapia Culture: A Bioeconomic Evaluation     

Gaspar Román Poot‐López  Eucario Gasca‐Leyva 《Journal of the World Aquaculture Society》2009,40(3):351-362

The main challenge for tilapia culture in rural areas of Mexico is low producer income and difficulty in acquiring inputs (fingerlings and balanced feed). In response, some rural producers feed tilapia with locally available vegetal inputs such as chaya, Cnidoscolus chayamansa. This plant is a bush endemic to the Yucatan Peninsula, Mexico, that is traditionally used for human and animal nutrition. In these rural culture systems, chaya is provided ad libitum as fresh leaves. Its use to date is empirical, and therefore, little is known about optimum substitution levels. A bioeconomic model was developed using experimental data. The von Bertalanffy model was parameterized using chaya/balanced feed combinations that produced growth not statistically different than a diet with sole use of balanced feed. This model included biological, economic, and management components. The results indicate that balanced feed can be substituted by chaya leaves at up to 50% and that this substitution level provides the lowest production costs during the warm season. Maintenance of this production level requires 2.23 units of chaya per unit of balanced feed, with the restriction that only 50% of the ration can be substituted by chaya leaves.  相似文献   

Unravelling the Anti-Inflammatory and Antioxidant Potential of the Marine Sponge Cliona celata from the Portuguese Coastline     

Joana Alves  Helena Gaspar  Joana Silva  Celso Alves  Alice Martins  Fernando Teodoro  Patrícia Susano  Susete Pinteus  Rui Pedrosa 《Marine drugs》2021,19(11)

Inflammation is a double-edged sword, as it can have both protective effects and harmful consequences, which, combined with oxidative stress (OS), can lead to the development of deathly chronic inflammatory conditions. Over the years, research has evidenced the potential of marine sponges as a source of effective anti-inflammatory therapeutic agents. Within this framework, the purpose of this study was to evaluate the antioxidant and the anti-inflammatory potential of the marine sponge Cliona celata. For this purpose, their organic extracts (C1–C5) and fractions were evaluated concerning their radical scavenging activity through 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and anti-inflammatory activity through a (lipopolysaccharides (LPS)-induced inflammation on RAW 264.7 cells) model. Compounds present in the two most active fractions (F5 and F13) of C4 were tentatively identified by gas chromatography coupled to mass spectrometry (GC-MS). Even though samples displayed low antioxidant activity, they presented a high anti-inflammatory capacity in the studied cellular inflammatory model when compared to the anti-inflammatory standard, dexamethasone. GC-MS analysis led to the identification of n-hexadecanoic acid, cis-9-hexadecenal, and 13-octadecenal in fraction F5, while two major compounds, octadecanoic acid and cholesterol, were identified in fraction F13. The developed studies demonstrated the high anti-inflammatory activity of the marine sponge C. celata extracts and fractions, highlighting its potential for further therapeutic applications.  相似文献   

Unravelling the Dermatological Potential of the Brown Seaweed Carpomitra costata     

Patrícia Susano  Joana Silva  Celso Alves  Alice Martins  Helena Gaspar  Susete Pinteus  Teresa Mouga  Mrcia Ines Goettert   eljko Petrovski  Luís B. Branco  Rui Pedrosa 《Marine drugs》2021,19(3)

The ever-increasing interest in keeping a young appearance and healthy skin has leveraged the skincare industry. This, coupled together with the increased concern regarding the safety of synthetic products, has boosted the demand for new and safer natural ingredients. Accordingly, the aim of this study was to evaluate the dermatological potential of the brown seaweed Carpomitra costata. The antioxidant, anti-enzymatic, antimicrobial, photoprotective and anti-inflammatory properties of five C. costata fractions (F1–F5) were evaluated. The ethyl acetate fraction (F3) demonstrated the most promising results, with the best ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals (EC₅₀ of 140.1 µg/mL) and the capacity to reduce reactive oxygen species (ROS) production promoted by UVA and UVB radiation in 3T3 cells, revealing its antioxidant and photoprotective potential. This fraction also exhibited the highest anti-enzymatic capacity, inhibiting the activities of collagenase, elastase and tyrosinase (IC₅₀ of 7.2, 4.8 and 85.9 µg/mL, respectively). Moreover, F3 showed anti-inflammatory potential, reducing TNF-α and IL-6 release induced by LPS treatment in RAW 264.7 cells. These bioactivities may be related to the presence of phenolic compounds, such as phlorotannins, as demonstrated by NMR analysis. The results highlight the potential of C. costata as a source of bioactive ingredients for further dermatological applications.  相似文献