857 research outputs found
Moderate biomanipulation for eutrophication control in reservoirs using fish captured in angling competitions
Angling competitions are a popular leisure activity in reservoirs of
Southern Portugal. These competitions can gather more than 100 anglers
aiming to catch the maximum fish weight. Groundbaiting and catch-andrelease
angling are two common practices for anglers in competition. In
this study, the loads of nutrients from commercial groundbait powders
used in angling competitions in the Maranhão reservoir and the possible
balance out of those nutrients through a moderate biomanipulation of the
fish biomass caught in competitions were analysed. In order to achieve
this aim, chemical analyses to groundbait powders most purchased by
Portuguese anglers and to fish species most captured in competitions
were made. Mass balances on inputs and outputs of nutrients considering
some biomanipulation scenarios were evaluated. Results demonstrated
that an effective management on angling competitions implementing a
moderate biomanipulation of fish in reservoirs could promote the control
of fish fauna and eutrophication, balancing out nutrients from anglinginfo:eu-repo/semantics/publishedVersio
The detection of viable vegetative cells of Bacillus sporothermodurans using propidium monoazide with semi-nested PCR
AbstractBacillus sporothermodurans produces highly heat-resistant spores that can survive ultra-high temperature (UHT) treatment in milk. Therefore, we developed a rapid, specific and sensitive semi-nested touchdown PCR assay combined with propidium monoazide (PMA) treatment for the detection of viable B. sporothermodurans vegetative cells. The semi-nested touchdown PCR alone proved to be specific for B. sporothermodurans, and the achieved detection limit was 4 CFU/mL from bacterial culture and artificially contaminated UHT milk. This method combined with PMA treatment was shown to amplify DNA specifically from viable cells and presented a detection limit of 102 CFU/mL in UHT milk. The developed PMA-PCR assay shows applicability for the specific detection of viable cells of B. sporothermodurans from UHT milk. This method is of special significance for applications in the food industry by reducing the time required for the analysis of milk and dairy products for the presence of this microorganism
Molecular Interactions in Ionic Liquids: The NMR Contribution towards Tailored Solvents
Ionic liquids have been on the spotlight of chemical research field in the last decades. Their physical properties (low vapor pressure, thermal stability, and conductivity) and the possibility of fine tuning make them a versatile class of compounds for a wide range of applications, such as catalysis, energy, and material sciences. Ionic liquids can establish multiple intermolecular interactions with solutes such as electrostatic, van der Waals, or hydrogen bonds. The prospect of designing ionic liquid structures toward specific applications has attracted the attention to these alternative solvents. However, their rational design demands a molecular detailed view, and Nuclear Magnetic Resonance is a unique and privileged technique for this purpose, as it provides atomic resolution and at the same time enables the study of dynamic information. In this chapter, we provide an overview about the application of Nuclear Magnetic Resonance spectroscopy techniques as a methodology for the rational design of ionic liquids as solvents for small organic compounds, CO2 capture, and polymers such as cellulose focusing mainly in the last 10 years
Spirometry And Volumetric Capnography In Lung Function Assessment Of Obese And Normal-weight Individuals Without Asthma
To analyze and compare lung function of obese and healthy, normal-weight children and adolescents, without asthma, through spirometry and volumetric capnography. Methods: Cross-sectional study including 77 subjects (38 obese) aged 5-17 years. All subjects underwent spirometry and volumetric capnography. The evaluations were repeated in obese subjects after the use of a bronchodilator. Results: At the spirometry assessment, obese individuals, when compared with the control group, showed lower values of forced expiratory volume in the first second by forced vital capacity (FEV1/FVC) and expiratory flows at 75% and between 25 and 75% of the FVC (p <0.05). Volumetric capnography showed that obese individuals had a higher volume of produced carbon dioxide and alveolar tidal volume (p <0.05). Additionally, the associations between dead space volume and tidal volume, as well as phase-3 slope normalized by tidal volume, were lower in healthy subjects (p <0.05). These data suggest that obesity does not alter ventilation homogeneity, but flow homogeneity. After subdividing the groups by age, a greater difference in lung function was observed in obese and healthy individuals aged >11 years (p <0.05). Conclusion: Even without the diagnosis of asthma by clinical criteria and without response to bronchodilator use, obese individuals showed lower FEV1/FVC values and forced expiratory flow, indicating the presence of an obstructive process. Volumetric capnography showed that obese individuals had higher alveolar tidal volume, with no alterations in ventilation homogeneity, suggesting flow alterations, without affecting lung volumes. © 2017 Sociedade Brasileira de Pediatria
Ocean acidification may slow the pace of tropicalization of temperate fish communities
Poleward range extensions by warm-adapted sea urchins are switching temperate marine ecosystems from kelp-dominated to barren-dominated systems that favour the establishment of range-extending tropical fishes. Yet, such tropicalization may be buffered by ocean acidification, which reduces urchin grazing performance and the urchin barrens that tropical range-extending fishes prefer. Using ecosystems experiencing natural warming and acidification, we show that ocean acidification could buffer warming-facilitated tropicalization by reducing urchin populations (by 87%) and inhibiting the formation of barrens. This buffering effect of CO₂ enrichment was observed at natural CO₂ vents that are associated with a shift from a barren-dominated to a turf-dominated state, which we found is less favourable to tropical fishes. Together, these observations suggest that ocean acidification may buffer the tropicalization effect of ocean warming against urchin barren formation via multiple processes (fewer urchins and barrens) and consequently slow the increasing rate of tropicalization of temperate fish communities.Ericka O.C. Coni, Ivan Nagelkerken, Camilo M. Ferreira, Sean D. Connell and David J. Boot
Characterization and commercialization of fresh tomatoes at CEASA: profile of wholesalers
The Terminal Markets are the main centers for distribution of vegetables, fruits and flowers from different States of Brazil. The CEAGESP wholesalers can be shippers or growers. The amount of tomato commercialized in these terminal markets is very expressive. It was possible to determine the profile and the main features of the wholesale market at CEAGESP. About 45.8% of the wholesalers had an average commercialization volume of 10,000 tons/year, and 70.8% of them commercialize their own production. Cultivars Carmen and Débora were the leaders on the market. The results pointed out that wholesalers had more than one type of buyer, and the main ones were street fair and supermarkets. Most of the tomato is commercialized in boxes (box K), followed by 20.8% of plastic boxes and 16.7% of cardboard packages. CEAGESP wholesalers adopt tomato classification, either done manually (58.4%), or by machines (8.3%) or using both systems (33.3%). The standardization index was not satisfactory, with color and sizes in different degrees, and therefore 45.8% has to be reclassified.Os Centros de Abastecimento, conhecidos por CEASAS, são pontos de concentração física da produção de hortigranjeiros e flores oriundos de diversas regiões do país. As mercadorias são destinadas aos atacadistas, que podem também ser produtores rurais ou apenas intermediários. O tomate possui grande representatividade de comercialização dentro dessas centrais de abastecimento. A partir de questionários, identificou-se o perfil dos comerciantes de tomate de mesa na CEAGESP. Constatou-se que 45,8% dos entrevistados possuem um volume médio de tomate comercializado durante o ano maior que 10.000 toneladas, sendo que, desses, 70,8% possuem produção própria de tomate. As cultivares Carmen e Débora foram as líderes de comercialização no período avaliado. Os resultados apontaram que os atacadistas comercializam com mais de um tipo de comprador, sendo os principais feirantes e supermercados, com ampla utilização da embalagem de madeira, caixa K, seguindo com 20,8% em caixas plásticas e 16,7% com caixas de papelão. Os permissionários comercializam o tomate classificado, seja manualmente (58,4%), ou usando máquinas (8,3%) ou ambos os procedimentos (33,3%), porém os índices de padronização não são satisfatórios, encontrando-se numa mesma caixa mistura intensa de graus de coloração e tamanhos variados, o que leva a 45,8% do produto a ser reclassificado.32432
Comprehensive evaluation of the linear stability of Alfvén eigenmodes driven by alpha particles in an ITER baseline scenario
The linear stability of Alfvén eigenmodes in the presence of fusion-born alpha particles is thoroughly assessed for two variants of an ITER baseline scenario, which differ significantly in their core and pedestal temperatures. A systematic approach based on CASTOR-K (Borba and Kerner 1999 J. Comput. Phys. 153 101; Nabais et al 2015 Plasma Sci. Technol. 17 89) is used that considers all possible eigenmodes for a given magnetic equilibrium and determines their growth rates due to alpha-particle drive and Landau damping on fuel ions, helium ashes and electrons. It is found that the fastest growing instabilities in the aforementioned ITER scenario are core-localized, low-shear toroidal Alfvén eigenmodes. The largest growth-rates occur in the scenario variant with higher core temperatures, which has the highest alpha-particle density and density gradient, for eigenmodes with toroidal mode numbers . Although these eigenmodes suffer significant radiative damping, which is also evaluated, their growth rates remain larger than those of the most unstable eigenmodes found in the variant of the ITER baseline scenario with lower core temperatures, which have and are not affected by radiative damping
Sensitivity of alpha-particle-driven Alfvén eigenmodes to q-profile variation in ITER scenarios
A perturbative hybrid ideal-MHD/drift-kinetic approach to assess the stability of alpha-particle-driven Alfv�n eigenmodes in burning plasmas is used to show that certain foreseen ITER scenarios, namely the MA baseline scenario with very low and broad core magnetic shear, are sensitive to small changes in the background magnetic equilibrium. Slight variations (of the order of ) of the safety-factor value on axis are seen to cause large changes in the growth rate, toroidal mode number, and radial location of the most unstable eigenmodes found. The observed sensitivity is shown to proceed from the very low magnetic shear values attained throughout the plasma core, raising issues about reliable predictions of alpha-particle transport in burning plasmas
Ocean acidification boosts reproduction in fish via indirect effects
Ocean acidification affects species populations and biodiversity through direct negative effects on physiology and behaviour. The indirect effects of elevated CO₂ are less well known and can sometimes be counterintuitive. Reproduction lies at the crux of species population replenishment, but we do not know how ocean acidification affects reproduction in the wild. Here, we use natural CO₂ vents at a temperate rocky reef and show that even though ocean acidification acts as a direct stressor, it can indirectly increase energy budgets of fish to stimulate reproduction at no cost to physiological homeostasis. Female fish maintained energy levels by compensation: They reduced activity (foraging and aggression) to increase reproduction. In male fish, increased reproductive investment was linked to increased energy intake as mediated by intensified foraging on more abundant prey. Greater biomass of prey at the vents was linked to greater biomass of algae, as mediated by a fertilisation effect of elevated CO₂ on primary production. Additionally, the abundance and aggression of paternal carers were elevated at the CO₂ vents, which may further boost reproductive success. These positive indirect effects of elevated CO₂ were only observed for the species of fish that was generalistic and competitively dominant, but not for 3 species of subordinate and more specialised fishes. Hence, species that capitalise on future resource enrichment can accelerate their reproduction and increase their populations, thereby altering species communities in a future ocean.Ivan Nagelkerken, Tiphaine Alemany, Julie M. Anquetin, Camilo M. Ferreira, Kim E. Ludwig, Minami Sasaki, Sean D. Connel
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