Explore the vast range of titles available.

Abstract This study assessed the effect of salinity on the development of the mangrove oyster, Crassostrea rhizophorae, during the pediveliger, metamorphosis, and post-larvae stages, with individuals retained on ≥ 345 µm and ≥ 700 µm meshes. The experiment followed a completely randomized design with five salinity treatments (15, 20, 25, 30, and 35) and four replicates, conducted in three phases: (1) pediveliger and metamorphosis (7-day duration); (2) post-larvae retained on a ≥ 345 and < 500 µm mesh (16-day duration); and (3) post-larvae retained on ≥ 700 and < 1,000 µm meshes (21-day duration). Experimental units consisted of a downwelling system using screen-bottomed PVC cylinders. Oysters were fed Isochrysis galbana and Chaetoceros sp., with feed concentrations adjusted for each developmental stage. Yield (percentage of the initial stock retained alive on the final mesh) and survival (total live post-larvae relative to the initial stocked number) were determined by sieving. A salinity of 30 produced the highest yield during the pediveliger and metamorphosis phase (31.94% ± 4.53%), while salinities between 15 and 30 favored survival for post-larvae in the ≥ 345 µm size class. No significant differences in survival or yield were detected during the final post-larval stage. Overall, a salinity of 30 is recommended for the final larval and the post-larval stage for C. rhizophorae. Resumo Este estudo avaliou o efeito da salinidade no desenvolvimento da ostra Crassostrea rhizophorae nas fases de pedivéliger, metamorfose e pós-larvas retidas em malhas ≥ 345 µm e ≥ 700 µm. O experimento foi conduzido em delineamento inteiramente casualizado, com cinco tratamentos (salinidades 15, 20, 25, 30 e 35) e quatro repetições, em três fases: (1) pedivéliger e metamorfose (sete dias), (2) pós-larvas inicialmente retidas em malha ≥ 345 e < 500 µm (16 dias), e (3) pós-larvas inicialmente retidas em malha ≥ 700 e < 1,000 µm (21 dias). Utilizou-se um sistema downwelling com cilindros de PVC e fundo de tela como unidades experimentais. A alimentação consistiu em dieta composta por Isochrysis galbana e Chaetoceros sp., com concentrações ajustadas conforme a fase de desenvolvimento. Os dados de rendimento (taxa de pós-larvas vivas retidas nas malhas finais em cada fase, em relação ao povoamento inicial) e sobrevivência (número total de pós-larvas vivas em relação ao número de animais povoados em cada unidade) foram obtidos por peneiramento. Os dados foram submetidos a análise de variância (ANOVA), Kruskal-Wallis e teste de Tukey. Os resultados indicaram que a salinidade 30 proporcionou maior rendimento na fase pedivéliger e metamorfose (31,94% ± 4,53%), enquanto salinidades entre 15 e 30 favoreceram a sobrevivência na fase de pós-larva ≥ 345 µm. Não foram observadas diferenças significativas na sobrevivência e rendimento das pós-larvas entre os tratamentos na fase final. Conclui-se que a salinidade 30 deve ser usada no final do cultivo larval e na fase de pós-larvas para Crassostrea rhizophorae.

The detectability of invasive organisms influences the costs and benefits of alternative control strategies, and the feasibility of eradicating an infestation. Search theory offers a mathematically rigorous framework for defining and measuring detectability taking account of searcher ability, biological factors and the search environment. In this paper, invasive species detectability is incorporated into a population simulation model. The model is applied to a base set of parameter values that represent reasonable values for a hypothetical weed. The analysis shows the effects of detectability and search effort on the duration of an eradication program. For a given level of detectability and search time, the analysis shows that the variables with the greatest influence on the duration of the eradication effort are search speed, kill efficiency, germination rate and seed longevity. Monte Carlo simulations are performed on a set of four weed scenarios, involving different combinations of plant longevity, seed longevity and plant fecundity. Results of these simulations are presented as probability distributions and allow us to calculate how the probability of eradication will be affected by search strategy.[PUBLICATION ABSTRACT]

The epidemiology of non-tuberculous mycobacteria (NTM) in Spain is largely unknown because systematic reporting is not compulsory. The aim of our study was to describe the frequency and diversity of NTM species in our region and their distribution according to the source sample, gender, and age of the patients. We performed a multicenter study of all NTM isolated in 24 public hospitals in Madrid from 2013 to 2017. A total of 6.923 mycobacteria were isolated: 4535 (65.5%) NTM, and 2.388 (34.5%) Mycobacterium tuberculosis complex (MTB). Overall, 61 different NTM species were identified. The most frequently isolated species were Mycobacterium avium complex (47.7%), M. lentiflavum (12.2%), M. gordonae (9.2%), M. fortuitum (8.9%), and M. abscessus (3.9%). Whereas MTB cases were stable during the study period, the number of NTM isolates increased considerably from 930 isolates in 2013 to 1012 in 2017; a sharp increase occurred in the last year. The rise in NTM isolates was mostly due to M. lentiflavum, M. kansasii, and M. abscessus mainly isolated from respiratory specimens in patients older than 60. The increase in isolation rate of NTM in our region is consistent with the increasing rates reported worldwide in the last decades. The rise in NTM isolates was mainly attributed to M. lentiflavum but it also should be noted the increasing of species with high pathogenic potential such as M. kansasii and M. abscessus.

A novel method for separation and identification of ignitable liquid residues in fire debris by gas chromatography and mass spectrometry is presented. Preconcentration of the analytes was carried out using the simple headspace sorptive extraction (HSSE) technique. Polydimethylsiloxane stir bars were used as the enrichment phase, and parameters affecting both the adsorption and desorption stages were carefully optimized. Extraction was carried out at 50°C for 1h. Stir bars were desorbed thermally in the GC injection port, thus avoiding the use of organic solvents. The results for five ignitable liquids, including gasoline and diesel fuel, using HSSE were compared with those obtained with a solid-phase microextraction method, with HSSE appearing as a more sensitive alternative.

Two experiments were undertaken in three different experimental set-ups in order to compare them: an industrial 21-m3 pilot reactor, a new 40-ℓ laboratory pilot reactor and bmp type plasma bottles. Three consecutive batch dry digestion tests of municipal solid waste were performed under mesophilic conditions with the same feedstock in all vessels. Biogas and methane production at the end of the tests were similar (around 200 m3 CH4STP/tVS) for both pilot reactors and were different from the bottle tests. The dynamics of methane production and VFA accumulation concurred. However, the maximal levels of VFA transitory accumulation varied between reactors and between runs in a same reactor. Ammonia levels were similar in both reactors. These results show that the new reactor accurately imitates the conditions found in the larger one. Adaptation of microorganisms to the waste and operating conditions was also pointed out along the consecutive batches. Thermophilic semi-continuous tests were performed in both reactors with similar conditions. The methane production efficiencies were similar.

1. Eradication is often the preferred strategy in the management of new weed invasions, but recent research has shown that the circumstances under which eradication can be achieved are highly constrained. Containment is a component of an eradication strategy and also a management objective in its own right. Just as for eradication, containment of a weed invasion should be attempted only if it is considered feasible. However, very little guidance exists for the assessment of containment feasibility for weeds. 2. Numerous factors have been proposed as influencing feasibility of containment, but those that relate to the potential for management of dispersal pathways and timely detection of new foci of infestation appear to be critical. Theory suggests that the rate of spread is largely driven by long‐distance dispersal (LDD). However, LDD is generally unpredictable and often occurs for species that do not appear to be adapted for it. Furthermore, many (if not most) LDD events fail to give rise to new infestations. 3. As the probability of colonisation is related to the numbers of propagules immigrating (‘propagule pressure’) at a point in the landscape, dispersal pathways that move relatively large numbers of propagules simultaneously and/or repeatedly should most enhance weed spread. It is these pathways whose potential for management has the greatest bearing upon containment feasibility. A key impediment to containment is undetected spread; this need not occur through LDD and is more likely to occur through dispersal to lesser distances. 4. Synthesis and applications. Feasibility of containment should be viewed in terms of the effort required to reduce weed spread rate, as well as the effectiveness of relevant management actions. Where dispersal vectors are not readily manageable and the probability of detection via structured and/or unstructured surveillance is low, a much greater reliance upon fecundity control will be needed to contain a weed. A combination of empirical and theoretical approaches should be used to develop and refine estimates of containment feasibility. Such estimates will aid decision‐making with regard to whether to attempt to reduce weed spread and assist in prioritisation of different weeds for containment.

It has been recognised for some time that the community has an important role to play in invasive-species management. Reports from the community about new incursions can lead to significant cost savings when this early detection results in shorter management programs. Unfortunately there is little to guide invasive-species managers on cost-effective ways to elicit and incorporate information from the public in their pest-management programs. Not all community surveillance is equal: some information from the public about the presence of pests and diseases may arise from chance encounters, other data may be reported by stakeholders from a particular industry or by groups of volunteers organised on the basis of citizen science activities. While the resources, activities and effort required to encourage each type of community surveillance are known to differ, very little is known of the relationships that determine effectiveness, and thus the appropriate level of investment that would be required to encourage a particular level of reporting. In this research we focus on passive surveillance—the most fortuitous type of community surveillance—and review the current knowledge base on measuring its cost and effectiveness. We aim to stimulate the research required to improve our understanding of passive surveillance, and we provide guidance on the type of data that should be collected by agencies to enable this research. This information could then provide us with the ability to design optimal surveillance portfolios that integrate the surveillance opportunities provided by the public to best advantage.

Climate change is threatening food security in many tropical countries, where a large proportion of food is produced by vulnerable smallholder farmers. Interventions are available to offset many of the negative impacts of climate change on agriculture, and they can be tailored to local conditions often through relative modest investments. However, little quantitative information is available to guide investment or policy choices at a time when countries and development agencies are under pressure to implement policies that can help achieve Sustainable Development Goals while coping with climate change. Among smallholder adaptation options, developing seeds resilient to current and future climate shocks expected locally is one of the most important actions available now. In this paper, we used national and local data to estimate the costs of climate change to smallholder farmers in Malawi and Tanzania. We found that the benefits from adopting resilient seeds ranged between 984 million and 2.1 billion USD during 2020–2050. Our analysis demonstrates the benefits of establishing and maintaining a flexible national seed sector with participation by communities in the breeding, delivery, and adoption cycle.

Background and Aims The presence of halophenol (HP) and haloanisole (HA) compounds in wine cellar environments, in products in contact with wine production, and consequently in wines is responsible for substantial economic losses to the industry. Their assessment is therefore of a great interest for wine producers. The aim of this study was to develop a rapid and sensitive analytical method for the simultaneous determination of 22 HPs and HAs in wine cellar atmospheres, as well as in corks, wooden staves and wines. Methods and Results A rapid solid liquid extraction method assisted by ultrasound was applied to isolate the analytes from solid samples, and dispersive liquid–liquid microextraction was used for preconcentration purposes. The enriched extracts were analysed by gas chromatography–mass spectrometry. Variables related with the dispersive liquid–liquid microextraction procedure and the derivatisation of HPs by in situ acetylation were optimised using multivariable approaches based on central composite designs. The optimised method provides a detection limit of between 0.006 and 0.05 ng/mL (0.02 and 0.2 ng/g, for solid samples) and enrichment factors in the 125‐ to 300‐fold range. Conclusions The analytical characteristics of the method make it a valuable tool for the routine monitoring of HPs and HAs in wine cellar facilities. Significance of the Study The unequivocal quantification of the 22 analytes studied allows wine producers to control the appearance of cork taint and hence the quality of their products.