Assessing anthropogenic pressures on estuarine fish nurseries along the Portuguese coast: a multi-metric index and conceptual approach

Estuaries are among the most productive ecosystems and simultaneously among the most threatened by conflicting human activities which damage their ecological functions, namely their nursery role for many fish species. A thorough assessment of the anthropogenic pressures in Portuguese estuarine systems (Douro, Ria de Aveiro, Mondego, Tejo, Sado, Mira, Ria Formosa and Guadiana) was made applying an aggregating multi-metric index, which quantitatively evaluates influences from key components: dams, population and industry, port activities and resource exploitation. Estuaries were ranked from most (Tejo) to least pressured (Mira), and the most influential types of pressure identified. In most estuaries overall pressure was generated by a dominant group of pressure components, with several systems being afflicted by similar problematic sources. An evaluation of the influence of anthropogenic pressures on the most important sparidae, soleidae, pleuronectidae, moronidae and clupeidae species that use these estuaries as nurseries was also performed. To consolidate information and promote management an ecological conceptual model was built to identify potential problems for the nursery function played by these estuaries, identifying pressure agents, ecological impacts and endpoints for the anthropogenic sources quantified in the assessment. This will be important baseline information to safeguard these vital areas, articulating information and forecasting the potential efficacy of future management options.     

Color Doppler flow imaging for the early detection of nonpregnant cattle at 20 days after timed artificial insemination

The objective was to determine the accuracy of a pregnancy test for predicting nonpregnant cattle based on the evaluation of corpus luteum (CL) blood flow at 20 d (CLBF-d20) after timed artificial insemination (TAI). Crossbred Holstein-Gir dairy heifers (n = 209) and lactating cows (n = 317) were synchronized for TAI using the following protocol: intravaginal implant (1.0 g of progesterone) and 2 mg of estradiol benzoate i.m. on d −10, implant removal and 0.526 mg of sodium cloprostenol i.m. on d −2, 1 mg of estradiol benzoate i.m. on d −1, and TAI on d 0. On d 20, animals underwent grayscale ultrasonography (US) to locate the CL and color flow Doppler to evaluate CLBF-d20 using a portable ultrasound equipped with a 7.5-MHz rectal transducer. Based only on a visual, subjective CLBF evaluation, the animals were classified as pregnant or not pregnant. On d 30 to 35, blinded from results of the previous diagnosis, the same operator performed a final pregnancy diagnosis using US to visualize the fetal heartbeat (gold standard; US-d30). A second evaluator also analyzed the CLBF-d20 in the same animals by watching 7-s recorded videos. Blood samples were collected from a subset of 171 females to determine, by RIA, plasma progesterone (P₄) concentrations, which indicate CL function. The final pregnancy outcome (US-d30) was retrospectively compared with the CLBF-d20 diagnoses and then classified either as correct or incorrect. The number of true positive, true negative, false positive, and false negative decisions were inserted into a 2 × 2 decision matrix. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the CLBF-d20 test were calculated using specific equations. Binomial variables (pregnancy rate and proportions) were analyzed using Fisher’s exact test for the effect of parity and to compare between evaluators and tests (CLBF-d20 vs. plasma P₄). The kappa values were calculated to quantify the agreement between CLBF-d20 and the gold standard (US-d30) and between evaluators. The performance parameters of CLBF-d20 test were as follows: sensitivity = 99.0%, specificity = 53.7%, positive predictive value = 65.1%, negative predictive value = 98.5%, and accuracy = 74.8%. False negatives represented only 0.4% of the exams. No differences existed in these parameters between evaluators (no. 1 vs. no. 2) and tests (CLBF-d20 vs. plasma P₄). Moreover, a high level of agreement was observed between evaluators (0.91). In conclusion, visual evaluation of CLBF-d20 represents a quick, reliable, and consistent diagnostic test that enables the early detection of nonpregnant cattle.     

The Effects of Probiotics,Prebiotics and Synbiotics in Non-Alcoholic Fat Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH): A Systematic Review

Modifications in the microbiota caused by environmental and genetic reasons can unbalance the intestinal homeostasis, deregulating the host’s metabolism and immune system, intensifying the risk factors for the development and aggravation of non-alcoholic fat liver disease (NAFLD). The use of probiotics, prebiotics and synbiotics have been considered a potential and promising strategy to regulate the gut microbiota and produce beneficial effects in patients with liver conditions. For this reason, this review aimed to evaluate the effectiveness of probiotics, prebiotics, and symbiotics in patients with NAFLD and NASH. Pubmed, Embase, and Cochrane databases were consulted, and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines were followed. The clinical trials used in this study demonstrated that gut microbiota interventions could improve a wide range of markers of inflammation, glycemia, insulin resistance, dyslipidemia, obesity, liver injury (decrease of hepatic enzymes and steatosis and fibrosis). Although microbiota modulators do not play a healing role, they can work as an important adjunct therapy in pathological processes involving NAFLD and its spectrums, either by improving the intestinal barrier or by preventing the formation of toxic metabolites for the liver or by acting on the immune system.     

Superior Thermoelectric Performance of SiGe Nanowires Epitaxially Integrated into Thermal Micro-Harvesters

Semiconductor nanowires have demonstrated fascinating properties with applications in a wide range of fields, including energy and information technologies. Particularly, increasing attention has focused on SiGe nanowires for applications in a thermoelectric generation. In this work, a bottom-up vapour-liquid-solid chemical vapour Deposition methodology is employed to integrate heavily boron-doped SiGe nanowires on thermoelectric generators. Thermoelectrical properties –, i.e., electrical and thermal conductivities and Seebeck coefficient – of grown nanowires are fully characterized at temperatures ranging from 300 to 600 K, allowing the complete determination of the Figure-of-merit, zT, with obtained values of 0.4 at 600 K for optimally doped nanowires. A correlation between doping level, thermoelectric performance, and elemental distribution is established employing advanced elemental mapping (synchrotron-based nano-X-ray fluorescence). Moreover, the operation of p-doped SiGe NWs integrated into silicon micromachined thermoelectrical generators is shown over standalone and series- and parallel-connected arrays. Maximum open circuit voltage of 13.8 mV and power output as high as 15.6 µW cm⁻² are reached in series and parallel configurations, respectively, operating upon thermal gradients generated with hot sources at 200 °C and air flows of 1.5 m s⁻¹. These results pave the way for direct application of SiGe nanowire-based micro-thermoelectric generators in the field of the Internet of Things.     

Electric field-assisted sintering anode-supported single solid oxide fuel cell

Cosintering (La_0.84Sr_0.16MnO₃ thin-film cathode/ZrO₂: 8 mol% Y₂O₃ thin-film solid electrolyte/55 vol.% ZrO₂:8 mol% Y₂O₃ + 45 vol.% NiO anode, ϕ = 12 × 1.5 mm thick pellet) was achieved by applying an electric field for 5 min at 1200°C. Impedance spectroscopy measurements of the anode-supported three-layer cell show an improvement of the electrical conductivity in comparison to that of a conventionally sintered cell. The scanning electron microscopy images of the cross-sections of electric field-assisted pressureless sintered cells show a fairly dense electrolyte and porous anode and cathode. Joule heating, resulting from the electric current due to the application of the AC electric field, is suggested as responsible for sintering. Dilatometric shrinkage curves, electric voltage and current profiles, impedance spectroscopy diagrams, and scanning electron microscopy micrographs show how anode-electrolyte-cathode ceramic cells can be cosintered at temperatures lower than the usually required.     

Review of antenna technologies for very high frequency Data Exchange Systems

The Automated Identification System (AIS) was originally developed as a terrestrial system tracking vessels near the coastline. Dedicated channels were allocated within the spectrum historically reserved for maritime applications in the very high frequency (VHF) band, enabling long range communications, up to a few kilometers. There have been various initiatives in the last decade that extended this system with a space segment, enabling global monitoring of vessels beyond the range of terrestrial stations. Recently, the World Radiocommunication Conference has allocated frequencies for the extension of this system to a two-way VHF Data Exchange System (VDES) via satellite. This requires to adapt spaceborne antenna solutions previously developed for AIS, particularly for missions using small satellites and CubeSats. This paper provides a timely review of existing VHF antenna solutions and new concepts under development which could be applicable to VDES missions. Some key metrics are identified to provide a comparative study between various candidate solutions. Considering the range of possible missions, from secondary payloads on-board larger satellites to dedicated constellations, it is believed that a number of antenna products can find application in future VDES space-based infrastructure.     

Selective hydrogenation of oleic acid to fatty alcohols using Rh-Sn-B/TiO2 catalysts: Influence of Sn content

The influence of the catalyst Sn content on the production of fatty alcohol from oleic acid by selective hydrogenation was studied using Rh-Sn-B catalysts supported on TiO₂. The crystal phase of the support was analyzed by X-ray diffraction (XRD), the reduction state of the metal phase by temperature-programmed reduction (TPR), and the electronic state of surface species by X-ray photoelectron spectroscopy (XPS). The metal activity was evaluated by the dehydrogenation of cyclohexane. It was found that the increase in Sn content leads to a proportional drop in the catalytic activity, which could be related to a metallic interaction between Rh and Sn, as shown by TPR. Oxide and metallic Sn, as well as Rh⁰ and Rh³⁺, were found by XPS on the catalyst surface. Metallic Rh was, however, found in higher concentration than oxidized Rh in all cases. The yield to fatty alcohols increased with Sn content, and its maximum value for oleyl and stearyl alcohol was 96%. Furthermore, a higher yield (88.3%) was obtained out of unsaturated fatty alcohol (oleyl alcohol), which has proved to be more valuable than saturated alcohol. This was attributed to an adequate Rh/Sn ratio, which modulates the hydrogenating activity of Rh and makes the metal function more selective for hydrogenation of the carbonyl group. The influence of the support on the catalyst performance decreases as the Sn content increases. The support has a practically negligible influence on the catalyst activity for 4–5 wt.% of Sn content.     

Soybean Oil and Selenium Yeast Supplementation in Quail's Diet: Productive Performance,Fatty Acid Profile,Enzyme Activity,and Oxidative Stability of Meat

The objective of this study is to evaluate the influence of different soybean oil (SO) and selenium yeast (SeY) levels in the diet of meat quails on productive performance, physicochemical, quality measurements, fatty acid profile, enzyme activity estimation, and oxidative stability of meat. A total of 288 one-day old commercial meat quails are allocated into four groups according to a completely randomized experimental design, with two levels of SO (1.5% and 3.0%) and SeY (0 and 0.15 mg kg⁻¹) in the feed. The supplementation period is 42 days. The use of up to 3% supplementation of SO in the diet improves (p < 0.05) the productive performance. The polyunsaturated acid content and thiobarbituric acid value in the meat are increased (p < 0.05) as an effect of the SO increase in the diet. The use of SeY in quail diets associates with 3% inclusion of SO and promotes improvements in the qualitative parameters of the quail meat. Therefore, the inclusion of 0.15 mg kg⁻¹ of SeY in the diets is a viable alternative for improving the oxidative stability of meat since it improves the qualitative parameters of quail meat in diets with a high inclusion of SO. Practical Applications: These results have practical applicability in the meat industry, since it is possible to change the lipid profile of this raw material, meeting the requirement of the consumer market for healthy foods, reducing the total cholesterol content, and nutritionally desirable, through enrichment with polyunsaturated fatty acids.