A consistent model for leptogenesis, dark matter and the IceCube signal

We discuss a left-right symmetric extension of the Standard Model in which the three additional right-handed neutrinos play a central role in explaining the baryon asymmetry of the Universe, the dark matter abundance and the ultra energetic signal detected by the IceCube experiment. The energy spectrum and neutrino flux measured by IceCube are ascribed to the decays of the lightest right-handed neutrino $N_1$, thus fixing its mass and lifetime, while the production of $N_1$ in the primordial thermal bath occurs via a freeze-in mechanism driven by the additional $SU(2)_R$ interactions. The constraints imposed by IceCube and the dark matter abundance allow nonetheless the heavier right-handed neutrinos to realize a standard type-I seesaw leptogenesis, with the $B-L$ asymmetry dominantly produced by the next-to-lightest neutrino $N_2$. Further consequences and predictions of the model are that: the $N_1$ production implies a specific power-law relation between the reheating temperature of the Universe and the vacuum expectation value of the $SU(2)_R$ triplet; leptogenesis imposes a lower bound on the reheating temperature of the Universe at 7\times10^9\,\mbox{GeV}. Additionally, the model requires a vanishing absolute neutrino mass scale $m_1\simeq0$.Comment: 19 pages, 4 figures. Constraints from cosmic-ray antiprotons and gamma rays added, with hadrophobic assignment of the matter multiplets to satisfy bounds. References added. Matches version published in JHE

On Probing theta_{23} in Neutrino Telescopes

Among all neutrino mixing parameters, the atmospheric neutrino mixing angle theta_{23} introduces the strongest variation on the flux ratios of ultra high energy neutrinos. We investigate the potential of these flux ratio measurements at neutrino telescopes to constrain theta_{23}. We consider astrophysical neutrinos originating from pion, muon-damped and neutron sources and make a comparative study of their sensitivity reach to theta_{23}. It is found that neutron sources are most favorable for testing deviations from maximal theta_{23}. Using a chi^2 analysis, we show in particular the power of combining (i) different flux ratios from the same type of source, and also (ii) combining flux ratios from different astrophysical sources. We include in our analysis ``impure'' sources, i.e., deviations from the usually assumed initial (1 : 2 : 0), (0 : 1 : 0) or (1 : 0 : 0) flux compositions.Comment: 17 pages, 5 figures. Added discussion on experimental errors. To appear in PR

Illegal Selective Logging and Forest Fires in the Northern Brazilian Amazon

Illegal selective logging and forest fires occur on a large scale in the northern Brazilian Amazon, contributing to an increase in tree mortality and a reduction in forest carbon stock. A total of 120 plots of 0.25 ha (30 ha) were installed in transitional ecosystems or ecotones (LOt) between the forested shade-loving campinarana (Ld) and dense-canopy rainforest, submontane (Ds), in the National Forest (Flona) of Anauá, southern Roraima. Measuring the diameters at breast height (DBH ≥ 10 cm) and the heights of 171 dead trees (fallen naturally, illegally exploited, and affected by forest fires), enabled the estimation of carbon content from the application of a biomass equation developed at Manaus, and the calculation of a correction factor, using the average height of the largest trees. From 2015–2017, we mapped the real extent of illegal selective logging and forest fires across the region with CLASlite and INPE/Queimadas. From measurements of 14,730 live and dead trees across 30 hectares (491 ± 15 trees·ha-1), the illegal selective logging and associated forest fires, and aggravation by severe El Niño droughts resulted in an 8.2% mortality of trees (40 ± 9 dead trees·ha-1) and a 3.5% reduction in forest carbon stock (6 ± 3 Mg·ha-1) in the short-term. The surface area or influence of forest fires of very high density were estimated in the south-central region of Roraima (8374 km2) and the eastern region of the Flona Anauá (37 km2). Illegal selective logging and forest fires in forest areas totaled 357 km2 in the mosaic area, and 6 km2 within Flona Anaua. Illegal selective logging and forest fires in the years of severe El Niño droughts threatened the maintenance of environmental services provided by Amazonian forests

PORK QUALITY ASSESSMENT THROUGH IMAGE SEGMENTATION AND SUPPORT VECTOR MACHINE IMPLEMENTATION

Pork is the most consumed meat in the Philippines, and efficient quality control is essential for ensuring the safety of its consumers. Current manual procedures of meat inspection are time-consuming and laboratory-intensive considering the large amount of supply to be examined. This research aims to construct a rapid objective system of pork quality assessment with respect to meat freshness through Support Vector Machine (SVM) implementation, and to ultimately have an accuracy rate of ≥ 90%. 35 meat samples were collected, and their images were acquired. 30 of these were randomly designated as part of the training dataset while the rest were designated as part of the testing dataset. Of the 30 training samples, 6 were randomly chosen for the creation of a microbial profile. In all of the acquired image samples, image segmentation was performed and the RGB, HSV, Lab, and statistical texture features were extracted. These were inputted in 15 different SVM configurations. SVM classification yielded an accuracy rate of 93.33 %. Results from the microbial profile revealed considerable microbial activity at the 5th and 6th intervals (10th and 12th hour) with 2 and 3 colonies formed, respectively. With the ability of the SVM to distinguish between samples with respect to the hour interval and with the supplementation of the microbial profile, an objective artificial intelligence mechanism for freshness detection was successfully created.Keywords: Meat quality, Image segmentation, Support vector machine, Artificial intelligenc

Performance of candidates declaring dyslexia in the MRCGP clinical skills assessment: cross sectional study

Introduction There are increasing numbers of doctors with dyslexia undertaking the MRCGP licensing exam for general practice. Exam bodies seek to be fair to candidates with disabilities such as dyslexia as part of their Public Sector Equality Duty under the Equality Act 2010. We aimed to investigate performance of doctors declaring dyslexia in the Clinical Skills Assessment (CSA) component of the MRCGP. Methods We used a cross-sectional design, analysing routine candidate performance and demographic data from the MRCGP CSA between 2010 and 2017. We used multivariable logistic regression to compare candidates who declared dyslexia (either ‘early’ before their first attempt, or ‘late’ after failing at least once) with candidates who did not declare dyslexia to investigate the effect of declaring dyslexia on passing the CSA taking into account number of attempts, sex, place of primary medical qualification and ethnicity. Results Overall, 20879 candidates took the CSA between 2010 and 2017 of which 598 (2.9%) declared dyslexia. Candidates declaring dyslexia were no different in ethnicity compared with those who did not declare dyslexia but were significantly more likely to be male (47.3 vs 37.8; p<0.001) and to have a non-UK primary medical qualification (27.0% vs 22.4%; p=0.001). Candidates who declared dyslexia late were significantly more likely to fail the CSA compared with those candidates who declared early (40.6% vs 9.2%; p<0.001). They were also more likely to have a non-UK medical qualification (79.3% vs 15.7%; p<0.001) or come from a minority ethnic group (84.9% vs 39.2%; p<0.001). Candidates who declared dyslexia were significantly less likely to pass the CSA compared to candidates who did not declare dyslexia, particularly when this was declared late (Incident Rate Ratio [IRR] 0.78, 95%; confidence interval [CI] 0.67 to 0.91) but also when declared early (IRR 0.94 95%; CI] 0.92 to 0.97). Conclusion Trainees declaring dyslexia, and particularly declared late, were less likely to pass the CSA. Differential attainment in doctors with dyslexia needs to be addressed by investigating potential causes and finding solutions for such disparities as well as facilitating earlier assessment of dyslexia in those not previously diagnosed, particularly ethnic minority non-UK trained doctors

Fatias de banana liofilizadas como veículo probiótico: Influência da matriz de revestimento na sobrevivência e estabilidade dos probióticos

O mercado mundial de snacks (petiscos) com apelo de saudabilidade movimenta bilhões de dólares todos os anos. Dessa forma, este trabalho visou produzir fatias liofilizadas de banana como veículos de probióticos, a fim de investigar o efeito de diferentes matrizes polissacarídicas de revestimento na sobrevivência das cepas bacterianas Bacillus coagulans (esporogênica) e Lactobacillus acidophilus (não esporogênica) à secagem por liofilização e sua estabilidade durante o armazenamento. As cepas bacterianas foram compradas da empresa italiana Sacco (B. coagulans BC4 50 MLD, lote C235515A; L. acidophilus LA-3, lote C236623A). Foram preparadas três formulações para veicular os probióticos: celulose bacteriana (CB, combinada a carboximetilcelulose sódica - CMC ? à proporção 5:1 CB/CMC e homogeneizada em água destilada utilizando Ultra-Turrax a 16000 rpm); amido de milho (suspenso em água destilada estéril a 20% m/V, mantido em agitação e aquecido a 90ºC por 45 min para gelatinização); e água destilada estéril (sem matriz) como controle. A CB foi fornecida pela Biosmart Nanotecnologia (Araraquara, SP), produzida pela bactéria Komagataeibacter rhaeticus. Após o preparo das formulações, adicionou-se a elas uma das culturas bacterianas em quantidade calculada para garantir uma concentração de 8 log ufc/mL. A cultura estoque de B. coagulans liofilizada foi diretamente incorporada às formulações, já a cultura estoque de L. acidophilus foi previamente ativada em meio MRS. Bananas da variedade nanica foram cortadas em fatias de aproximadamente 5 mm, branqueadas em solução de ácido cítrico a 1% em ebulição por 1 min e, então, imersas em uma das formulações probióticas por 1 min. As fatias foram, por fim, congeladas a -25ºC por 24 h e liofilizadas por 6 dias. Resultados preliminares mostram que todas as formulações probióticas garantiram às fatias de banana uma boa concentração de probióticos pré liofilização (pelo menos 7 log UFC/g), sendo que a bactéria B. coagulans apresentou a melhor taxa de sobrevivência ao processo de secagem sem muita influência da matriz polissacarídica. Ainda é necessário analisar a estabilidade dos probióticos à armazenagem e realizar o teste de aceitação sensorial

Feeding ecology of five commercial shark species of the Celtic Sea through stable isotope and trace metal analysis

In order to trace their feeding habits, stable carbon and nitrogen isotope ratios (delta(15)N and delta(13)C), as well as trace metal concentrations (Zn, Cd, Fe, Cu, Se and Hg) were analysed in the tissues of five commercial shark species from the Celtic Sea: the tope shark Galeorhinus galeus, the black-mouthed catshark Galeus melastomus, the starry smooth hound Mustelus asterias, the spiny dogfish Squalus acanthias and the lesser-spotted dogfish Scyliorhinus canicula. Our results were compared to previously described stomach contents and isotopic composition of potential preys. Isotopic ratio delta(15)N suggested that tope sharks fed at a higher trophic level (16.7 parts per thousand in the muscle) than the other species, reflecting its piscivorous diet. The lower values of spiny dogfish (11.6 parts per thousand in the muscle) might be explained, amongst other things, by either its migratory behaviour or its preference for preys from lower trophic levels. Cd and Hg were correlated with isotopic ratios delta(13)C and delta(15)N, and were shown to be diet-related whereas Zn, Fe and Cu seemed much more linked to species-specific metabolism. Although this multidisciplinary approach is revealed as a useful tool for the study of shark ecology, the lack of known trophic fractionation suggests that isotopic data be compared to traditional diet analyses. (c) 2005 Elsevier Ltd. All rights reserved.Peer reviewe

Neutron Majorana mass from exotic instantons

We show how a Majorana mass for the Neutron could result from non-perturbative quantum gravity effects peculiar to string theory. In particular, "exotic instantons" in un-oriented string compactifications with D-branes extending the (supersymmetric) standard model could indirectly produce an effective operator delta{m} n^t n+h.c. In a specific model with an extra vector-like pair of `quarks', acquiring a large mass proportional to the string mass scale (exponentially suppressed by a function of the string moduli fields), delta{m} can turn out to be as low as 10^{-24}-10^{-25} eV. The induced neutron-antineutron oscillations could take place with a time scale tau_{n\bar{n}} > 10^8 s, that could be tested by the next generation of experiments. On the other hand, proton decay and FCNC's are automatically strongly suppressed and are compatible with the current experimental limits. Depending on the number of brane intersections, the model may also lead to the generation of Majorana masses for R-handed neutrini. Our proposal could also suggest neutron-neutralino or neutron-axino oscillations, with implications in UCN, Dark Matter Direct Detection, UHECR and Neutron-Antineutron oscillations. This suggests to improve the limits on neutron-antineutron oscillations, as a possible test of string theory and quantum gravity.Comment: 35 pages, 11 figures. More comments on neutron-neutralino mixin