MAGIC sensitivity to millisecond-duration optical pulses

The MAGIC telescopes are a system of two Imaging Atmospheric Cherenkov Telescopes (IACTs) designed to observe very high energy (VHE) gamma rays above ~50 GeV. However, as IACTs are sensitive to Cherenkov light in the UV/blue and use photo-detectors with a time response well below the ms scale, MAGIC is also able to perform simultaneous optical observations. Through an alternative system installed in the central PMT of MAGIC II camera, the so-called central pixel, MAGIC is sensitive to short (1ms - 1s) optical pulses. Periodic signals from the Crab pulsar are regularly monitored. Here we report for the first time the experimental determination of the sensitivity of the central pixel to isolated 1-10 ms long optical pulses. The result of this study is relevant for searches of fast transients such as Fast Radio Bursts (FRBs).Comment: Proceedings of the 35th International Cosmic Ray Conference (ICRC 2017), Bexco, Busan, Korea (arXiv:1708.05153

Hábitos alimentares de utentes adultos do centro de saúde de Castelo Branco

Em Portugal têm vindo a revelar-se alguns erros alimentares praticados por grande parte da população. Esses erros cometem-se por excesso de ingestão de certo tipo de alimentos que, consequentemente, levam a problemas no organismo, como é o caso da obesidade, diabetes, hipertensão arterial, entre outras doenças

Performance of the freshwater shrimp <i>Atyaephyra desmarestii</i> as indicator of stress imposed by textile effluents

Textile plants consume large volumes of water and produce a great amount of wastewaters, which can be important sources of toxic discharges in receiving environments. The objective of this study was to evaluate the acute toxicity of textile effluents on the freshwater shrimp A. desmarestii. A whole effluent toxicity test procedure was used to determine the aggregate toxicity of three samples taken before and after wastewater treatment in a textile mill. The following LC50 &minus; 48 h values (%, v/v) were calculated: Untreated effluent &minus;29% effluent (sample 1), 22% effluent (sample 2), and 47% (sample 3); Treated effluent &minus;73% effluent (sample 1), 74% effluent (sample 2), and &gt; 100% (sample 3). Based upon acute toxicity units (TUa = 100/LC50), untreated effluent varied from toxic in samples 1 and 3 (2.00 &le; TUa &le; 4.00) to very toxic in sample 2 (TUa &gt; 4.0), whereas treated effluent varied from no toxic in sample 3 to moderately toxic in samples 1 and 2 (1.33 &le; TUa &le; 1.99). Despite some limitations and constraints related to innate variability of industrial effluents, our results suggested that A. desmarestii can be a promising and potential test organism for assessing toxicity of complex chemical mixtures

Lipid and protein changes related to quality loss in frozen sardine (Sardina pilchardus) previously processed under high-pressure conditions

This research focuses on biochemical changes related to quality loss in frozen (−18 °C for 9 months) sardine (Sardina pilchardus) previously subjected to high-pressure (HP) processing (125–200 MPa). The inhibition (p < 0.05) of lipid hydrolysis development (lower free fatty acid formation and lipase activity), observed in frozen sardine as a result of the previous HP treatment, increased with the pressure level applied. Several parameters including peroxide value, thiobarbituric acid index, fluorescent compounds, and polyenes showed that the applied HP conditions prior to sardine freezing did not increase lipid oxidation. Also, HP did not induce a substantial modification of acid phosphatase and cathepsins B and D activities, and the electrophoretic patterns of sarcoplasmic and myofibrillar protein fractions did not change. However, HP processing led to a decrease in myofibrillar protein content in frozen pressure-treated fish, an effect that was higher in 175- and 200-MPa treated samples. In conclusion, this research showed that pressure treatments in the 125–200- MPa range with holding time of 0 min cause only minor modifications in biochemical indicators of deterioration throughout the subsequent frozen storage of samples for up to 9 months. This study shows the need to optimize HP conditions, particularly in the case of applications combining HP treatments, frozen storage, and thawing to obtain products with high quality and commercial viability

Cocoa Bar Antioxidant Profile Enrichment with Underutilized Apples Varieties

: The impact of dried apples (Malus × domestica Borkh.) addition on improving the antioxidant characteristics of dark chocolate was evaluated. The antioxidant activity was measured through DPPH scavenging activity and showed an increase in the cocoa bar with 'Nesta' dry apple (17.3% vs. 46.8%) in comparison to cocoa mass. The 15 polyphenols analyzed by UHPLC-ESI-MS/MS indicated great variability among the apple varieties. Quercetin was detected in the highest concentrations (ranged from 753.3 to 1915.5 µg g-1), while the lowest were for kaempferol 7-O-glucoside, measured only in 'Mora' and 'Nesta' cocoa bars (from 0.034 to 0.069 µg g-1, respectively). P-coumaric acid, trans-ferulic acid, and chlorogenic acid contribute largely to the antioxidant activity in cocoa bars. Principal component analysis shows that a cocoa bar with the addition of 'Nesta' dry apple differ from others due to its higher content of polyphenols (1614 ± 61.8 mg gallic acid equivalents per 100 g). In conclusion, data confirm that cocoa bars with dry apples might be considered as a polyphenol-enriched food

Effect of high-pressure processing of Atlantic mackerel (Scomber scombrus) on biochemical changes during commercial frozen storage

This research focuses on biochemical changes related to quality losses observed in Atlantic mackerel (Scomber scombrus) muscle stored under commercial frozen storage conditions (9 months, −18 °C) when subjected to highhydrostatic pressure (HHP) treatments (125, 150, 175, and 200 MPa for 0 min) before freezing. After freezing, free fatty acid (FFA) formation (lipid hydrolysis assessment) showed a marked inhibition in HHP-treated fish and during frozen storage of samples treated at 175 MPa. Fluorescence ratio (FR) assessment of tertiary lipid oxidation showed a partial inhibitory effect during the 0–9-month period for samples treated at 175 and 200 MPa. After a 3-month storage of samples treated at these pressure levels, one-dimensional SDS-PAGE analysis of the sarcoplasmic protein fraction revealed the disappearance of a band; additionally, samples treated at 150 MPa showed the same effect at month 9. After gel excision, trypsin digestion, tandem mass spectrometry (MS/MS), and sequence database analysis, the band was identified as phosphoglycerate mutase 2 (28.7 kDa). On the other hand, HHP processing did not show a significant effect on trimethylamine (TMA) values, primary and secondary lipid oxidation, PUFA levels, 1-D myofibril protein pattern, and the activity of acid phosphatase and cathepsins B and D. Biochemical quality indices such as FFA, TMA, and FR and the activity of acid phosphatase and cathepsin B showed a progressive increase throughout the frozen storage of all samples

Global Impact of Local Educational Innovation

The innovation is carried out according to the demands or needs of an industrial, social or economic sector and is aimed at the widest possible target audience. In teaching educational innovation, the demand for innovation is very local, it is generated in each subject and for the students of it. This causes that educational innovation cannot be easily transferred between subjects. But, to meet the demands of an educational sector, the target audience for which innovation is designed must be global. The objective of this work is to study whether teaching educational innovation can be considered globally (for a global target audience and for a need in the education sector), so that it can be applied and transferred between subjects from different contexts. The information provided, during 8 training courses, by 130 university professors belonging to 12 different universities has been analyzed. It has been shown that for a given need for improvement (passive habit in students), the profile of the target audience, the demand of the learning sector and the indicators to measure educational innovation can be raised in a common way for an entire educational sector; in this case, higher education. The conclusion is that educational innovation can be designed globally, applied locally and transferred to other contexts

The influence of zero-hours contracts on care worker well-being

Background Care workers have an important social role which is set to expand with the increasing age of the UK population. However, the majority of care workers are employed on zero-hours contracts. Aims Firstly, to investigate the relationship between working conditions and employee outcomes such as engagement and general mental well-being in a sample of UK care workers and management. Secondly, to assess whether the use of zero-hours contracts affects employee well-being. Methods A cross-sectional survey of domiciliary care and care home employees, undertaken using the Management Standards Indicator Tool (MSIT), Utrecht Work Engagement Scale (UWES) and General Health Questionnaire (GHQ). T-tests and multivariate linear regression evaluated the differences in scoring between those with differing contractual conditions and job roles, and associations of MSIT scores with UWES and GHQ factors. Results Employee understanding of their role and job control were found to be priority areas for improvement in the sample. Similarly, care workers reported greater occupational demands and lower levels of control than management. However, while zero-hours contracts did not significantly influence employee well-being, these employees had greater levels of engagement in their jobs. Despite this, a greater proportion of individuals with zero-hours contracts had scores above accepted mental health cut-offs. Conclusions Individual understanding of their role as care workers appears to play an important part in determining engagement and general mental well-being. However, more research is needed on the influence of zero-hours contracts on well-being, particularly in groups with increased likelihood of developing mental health disorders

Biomass-derived activated carbon as catalyst in the leaching of metals from a copper sulfide concentrate

Chalcopyrite is the resource with the highest amount of Cu content representing around 70–80% of the known reserves in the world. However, chalcopyrite like other copper sulfides, is usually found in deposits with grades around 0.4–0.5% copper. The exploitation of these reserves using traditional flotation methods followed by pyrometallurgical treatment of copper concentrate is at the limit of economic viability. Hydrometallurgical route would be more suitable for treating of these low-graded sulfide ores. However, chalcopyrite is refractory in ferric/sulfuric acid media and shows slow dissolution rates. For this a number of researches were carried out to accelerate the kinetics of leaching by adding pyrite, iron powder, nanosized silica, coal and activated carbon. The main objective of the present work was to study the use of one biomass-derived activated carbon as catalysts in the leaching of copper from chalcopyrite. Sulfuric acid solution of pH 1 with 5 g L-1 of Fe3+ was used as leaching agent. Experiments were performed at 90 °C and 250 rpm, during 48 and 96 h. Concentration of Cu, Zn, As, Sb and Co in the liquid phase was determined in order to evaluate their extraction degree, whereas solid residues were characterized by SEM-EDS and XRD. The presence of biomass-derived activated carbon significantly increased the extraction of copper, decreasing the leaching of arsenic. Furthermore, the use of biomass-derived activated carbon led to lower amounts of crystalline sulfur in the final residue