Estimating Queen Conch (Strombus gigas) home ranges using acoustic telemetry: implications for the design of marine fishery reserves

Marine reserves (MRs) may function as a vital tool in the conservation and management of marine resources if source populations are managed for the benefit of those downstream. Consequently, it is critical to evaluate the home range of marine animals to ensure that MRs are large enough to protect source populations. We used acoustic telemetry to study movements of adult queen conch (Strombus gigas) within aggregations at two sites in the Florida Keys from June 1997 through July 1998. A total of 68 conch were tagged and tracked for up to one year. Latitude and longitude of each conch were recorded biweekly and data used to estimate the minimum speed, degree of site fidelity, and home range of each animal. Conch showed significantly greater displacement/ time during the summer. There were no significant differences in movement rate, site fidelity, or size of home range between males and females. Mean home range was 5.98 ha. Based on estimated home ranges of the aggregations, the size and location of the existing reserves at these two sites were inadequate to protect the conch aggregations should the fishery reopen

Avaliação da actividade antioxidante de frutos secos

A ingestão de frutos secos pode trazer inúmeros benefícios à saúde humana devido à presença de compostos antioxidantes. Dessa forma, no presente trabalho pretendeu-se avaliar a actividade antioxidante de vários frutos secos, designadamente, avelãs, nozes, amêndoas e pinhões, adquiridos numa grande superfície da região e sujeitos a uma extracção com acetona 80% (v/v) durante 24 horas. Nas diferentes amostras foi avaliado o teor em fenóis totais através do método do Folin-Ciocalteau e a actividade antioxidante através dos métodos do efeito bloqueador dos radicais livres de DPPH e do Poder Redutor. Em termos gerais, as amêndoas e os pinhões foram os frutos secos que apresentaram os menores teores de fenóis totais, 7,0+1,5 e 6,9+1,2 mg GAE/g extracto, respectivamente, ao contrário das nozes, nas quais foi determinado um teor de fenóis totais cerca de 38 vezes superior aos anteriores (268+32 mg GAE/gextracto). Foram também as nozes que apresentaram maior actividade antioxidante, tanto em termos de poder redutor (EC50 = 0,091+0,015 mgextracto/mL) como de actividade bloqueadora de radicais livres, designadamente do radical DPPH (EC50 = 0,060+0,011 mgextracto/mL). Tendo em consideração os resultados obtidos em ambos os ensaios da actividade antioxidante, os frutos secos podem ser ordenados da seguinte forma: noz > avelã > pinhão > amêndoa. Com o presente trabalho demonstrou-se que, em termos gerais, os frutos secos são uma fonte natural de compostos bioactivos com potencial para melhorar a saúde humana e reduzir o risco de ocorrência de doenças. Em particular, verificou-se que as nozes são o fruto seco mais promissor de entre os analisados

Bedform variability and flow regime in a barrier-inlet system. The mesotidal Piedras mouth (Huelva, SW Spain)

Bedform fields from the Piedras River mouth (Huelva, SW Spain) have been studied using side-scan sonar techniques, combined with visual scuba-dives, and direct geometric measuring. The dominant flow regime has been determined from the results in these tidal environments, where erosive processes dominate during ebb, transporting sand as a bedload towards the mouth and central sector of the tidal channel. The process is reversed during tidal floods. During neap tides, larger bedforms maintain their geometry and position, whereas small ripples are re-oriented under different tidal conditions. Sand patches, dunes and ripples are interpreted as sediment bypassing zones. Large forms indicate high energy flow, which can only migrate when flow velocity reaches threshold values for the movement, with net sand transport towards open areas. Depositional features indicate low, moderate, and high-energy conditions. Here, a depositional regime dominated by sediment accommodation is dominant, where sandy sediments are continuously remobilized, transported and re-deposited, even closer to the estuarine mouth. In inner zones finer particles, such as clay and silt, are transported by tides as suspended matter and deposited in protected inner areas. The final results are long narrow tidal flats, which alternate with sandy areas dominated by erosion

Temperature- and pressure-dependent structural study of {Fe(pmd) 2[Ag(CN)2 ]2}n spin-crossover compound by neutron Laue diffraction

The effect of pressure (up to 0.17 GPa) on the spin-crossover compound {Fe(pmd)2[Ag(CN)2]2}n [orthorhombic isomer (II), pmd = pyrimidine] has been investigated by temperature- and pressure-dependent neutron Laue diffraction and magnetometry. The cooperative high-spin ¿ low-spin transition, centred at ca 180 K at ambient pressure, is shifted to higher temperatures as pressure is applied, showing a moderate sensitivity of the compound to pressure, since the spin transition is displaced by ca 140 K GPa-1. The space-group symmetry (orthorhombic Pccn) remains unchanged over the pressure–temperature (P–T) range studied. The main structural consequence of the high-spin to low-spin transition is the contraction of the distorted octahedral [FeN6] chromophores, being more marked in the axial positions (occupied by the pmd units), than in the equatorial positions (occupied by four [Ag(CN)2]- bridging ligands)

Sedimentología del lago de Carucedo (Ponferrada-León)

Se realiza el estudio de los depósitos del lago mediante el análisis de muestras correspondientes a 16 sondeos mecánicos. El relleno del lago aparece condicionado fundamentalmente por los aportes longitudinales a lo largo de un antiguo valle, mientras que los aportes laterales presentan menor importancia y, en parte, proceden de la destrucción de uno de los abanicos. El mecanismo fundamental de sedimentación se produce a partir de una suspensión puesta en funcionamiento por la entrada de aguas por puntos concretos, que dan lugar un "delta" de sedimentos gruesps mientras los finos pasan a suspensión y decantan lentamente. Se apunta su origen climático para los cambios en la sedimentación, asignando como posible edad Wurmiense, para los depósitos ricos en materia orgánica. Se obtiene una velocidad de sedimentación a partir de los datos obtenidos, del orden de 0,1 mm./año

Efeito da secagem por ar quente na cor e propriedades nutricionais de duas variedades de castanha (Castanea sativa Mill.)

O objetivo do nosso trabalho foi avaliar o efeito da secagem por ar quente, realizada num secador de tabuleiros a 50 °C (convecção forçada), nas propriedades físicas e nutricionais de castanha laminada ao longo do tempo de secagem (0, 4, 6 e 10 horas). Verificou-se um aumento na variação total de cor (ΔE) ao longo da desidratação. Contudo, esta mudança de cor não foi visualmente percetível. As alterações na composição nutricional também foram pouco significativas, mesmo após 10 horas de secagem. A variabilidade entre variedades foi maior do que a observada ao longo da secagem para cada variedade, sugerindo que o processo de desidratação não alterou significativamente as propriedades nutricionais da castanha. Devido ao seu baixo teor calórico (cerca de 367 kcal/100 g produto), reduzido teor de gordura e um interessante teor em fibras, além de não conter glúten, a castanha laminada apresenta-se como um excelente snack.A Teresa Delgado agradece à FCT pela bolsa de Doutoramento (SFRH/BDI82285/2011). Os autores agradecem ao CIMO (PEst-OEI AGR/UI0690/2011 ), ao REQUIMTE (PEst-CIEQBILA0006/2013) e ao POCTEP - Programa Cooperação Transfronteiriça Espanha-Portugal pelo apoio financeiro através do Projeto "REDI AGROTEC - Red transfi·onteriza Espana Portugal de experimentaci ón y transferencia para e! desanollo dei sector agropecuario y agroindustrial".info:eu-repo/semantics/publishedVersio

Effect of Drying on Color, Proximate Composition and Drying Kinetics of Sliced Chestnuts

In the present work, dried sliced chestnuts (Judia and Longal varieties), product with an increased shelf life, low calorie and gluten-free contents, were prepared. The effect of air convective drying on the drying kinetics, color and proximate composition of sliced chestnuts was evaluated. Even though significant differences in nutritional composition were found between both varieties at the beginning, the drying behaviors were similar; however, Judia dried at a slightly faster rate than Longal. The use of Page, two-term, and modified Henderson and Pabis models fitted well the experimental data (adjusted R 2 > 0.999). With drying, slight variations in color were observed for both varieties and only moisture content decreased significantly. The obtained product retained all chemical composition, and due to the low caloric value (367 kcal/100 g product), low fat and gluten-free contents of chestnut slices, this can be an interesting substitute to other high-calorie snacks available in the market. Practical Applications: The chestnut fruit is increasingly popular among consumers. The fruit is usually sold fresh or frozen while smaller fruits are generally rejected by industries. So, it is very important to find alternatives to valorize these fruits. Moreover, consumers search for healthy and easy-to-consume food. Chestnut follow these requisites, being a nut with interesting properties due to its low fat content, high levels of starch (sugar of slow absorption) and significant amounts of fibers. Furthermore, it is a gluten-free nut, ideal for celiac patients. On the other hand, the majority of snacks in the market are rich in fat and are made from wheat flour. So, the development of snacks based on chestnut would be innovative. This study intends to provide information on the effect of drying on color, nutritional composition and drying kinetics of sliced chestnut in order to obtain a healthy and low-calorie content snack.Teresa Delgado acknowledges the Fundação para a Ciência e Tecnologia (FCT) for the financial support through the PhD grant – SFRH/BD/82285/2011, CIMO through the Project PEst-OE/AGR/UI0690/2014, REQUIMTE through the Project PEst-C/EQB/LA0006/2013 and POCTEP – Programa de cooperação Transfronteiriça Espanha – Portugal through the Project RED/AGROTEC – Experimentation network and transfer for development of agricultural and agro industrial sectors between Spain and Portugal.info:eu-repo/semantics/publishedVersio

Efeitos de diferentes solventes e tempos na extracção de compostos antioxidantes presentes em avelãs (Corylus avellana L.)

Neste trabalho pretendeu-se estudar o efeito das condições experimentais sobre a extracção de fenóis totais presentes no miolo de avelã e na actividade antioxidante, de forma a avaliar o potencial destes frutos secos como fonte natural de antioxidantes. Foram testados três solventes (água em ebulição, metanol e acetona à temperatura ambiente) e vários tempos de contacto. Para cada situação, determinaram-se o rendimento de extracção, o teor em fenóis totais e o potencial antioxidante, avaliado pelo efeito bloqueador dos radicais livres de DPPH (2,2-difenil-1-picrilhidrazilo). Os maiores rendimentos de extracção foram obtidos para os extractos de acetona, aumentando com o tempo de contacto. Em relação aos fenóis totais, estes foram quantificados no miolo de avelã em todos os ensaios realizados, demonstrando a existência desses compostos no fruto. As maiores concentrações de fenóis totais foram obtidas com a extracção com água em ebulição (44,3+7,7 mg equivalentes de ácido gálico/g extracto) e acetona (80%) durante 24 H (36,2+8,8 mg equivalentes de ácido gálico/gextracto). Em relação à actividade antioxidante, os extractos mais eficientes (com menores valores de EC50), foram os de acetona, variando entre 1,12 e 1,53 mg/ml

Comparison of different drying methods on the chemical and sensory properties of chestnut (Castanea sativa M.) slices

The aim of this work was to determine the effect of hot-air convective drying (D), osmotic dehydration (OD), osmotic dehydration + drying (OD + D) and freeze-drying (FD) on chemical and sensorial characteristics of chestnut slices. Proximate composition, sugars, organic acids and lipid profiles were determined along 60 days of storage. Immediately after production, D and FD samples had similar proximate compositions, both with higher fat and protein contents than the osmodehydrated ones, the latter with increased sucrose contents. FD was the method that better preserved starch, amylose, ascorbic and citric acid molecules at day 0, while D originated samples with higher glucose and fructose contents. Along storage, the major variations were observed on organic acids: ascorbic acid decreased on all methods, while fumaric acid increased. Only small variations were observed on the fatty acids and vitamin E profiles and amounts. All samples presented similar and good overall sensorial acceptance with the exception of D. FD was the method that better preserved the sensorial characteristics until 60 days of storage, while D only preserved freshness until 15 days and OD + D until 30 days. In general terms, the most adequate and accepted preservation methods to apply to chestnuts would be FD and OD + D.Teresa Delgado acknowledges the Fundação para a Ciência e Tecnologia (FCT) for the financial support through the PhD grant—SFRH/BD/82285/2011 and REQUIMTE through the UID/QUI/50006/2013 project. The authors are also grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013).info:eu-repo/semantics/publishedVersio

Avaliação das propriedades nutricionais e sensoriais de snacks de castanha (Castanea sativa Mill.)

Aiming to increase the market offer of chestnut based products, for both increased economical return and shelf life, different preservation methods were tested on sliced chestnut. Hot air convective drying, osmotic dehydration, and freeze-drying, followed by both sensorial and chemical analysis (proximate composition, free sugars, organic acids and lipid profiles) during a storage period of up to 60 days were performed. Freeze-dried was the method that better preserved samples freshness, particularly regarding starch and ascorbic, but lipid oxidation after 60 days was higher. Osmotic dehydration followed by oven drying provided the highest sensorial scored samples, with increased lipid protection at expenses of sugar incorporation. In opposition, oven dried samples were less accepted from the sensorial point of view, despite the low composition variability. Along storage, the major variations were observed on the ascorbic acid contents, requiring more effective measures to prevent it. Both freeze-drying and osmotic dehydration followed by hot air convective drying are good methods to reduce chestnut losses associates with its natural perishability, while increasing market offer of healthy snacks.info:eu-repo/semantics/publishedVersio