Characterization and inhibitory activity of chitosan on hyphae growth and morphology of Botrytis cinerea plant pathogen

Summary. Low and high molecular weight chitosan were tested in different concentrations and growth times with the aim to evaluate the inhibitory activity against Botrytis cinerea, a very important plant pathogen. Tested chitosans were characterized by vibratory spectroscopy and elementary analyzes to determine the deacetylation degree. In addiction molar mass was estimated by viscosity measuring. Scanning electron microscopy was utilized for antimicrobial activity observation. Results showed that both chitosans markedly inhibited fungal growth, which was effected by incubation time and chitosan concentration. Scanning electron microscopy observations revealed that chitosan induced changes in surface morphology. The present study show that chitosan is capable of inhibit the growth and cause serious damage to the cell structure of the B. cinerea, as well as have the ability to form an impervious layer around the cell. Therefore, chitosan could be considered as a potential alternative for synthetic fungicides. Industrial relevance. Ultrastructural analysis showed that chitosan is capable of causing serious damage to the cell structure of the B. cinerea, as well as have the ability to form an impervious layer around the cell. Chitosan could inhibit the growth of B. cinerea in vitro and consequently may be considered as a potential alternative in replacement of synthetic fungicides.info:eu-repo/semantics/publishedVersio

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

A case study of the use of verbal reports for talent identification purposes in soccer: A Messi affair!

Using a two-study approach, the main purpose of this case study was to explore the use of a verbal reporting methodology to better understand the thought processes of soccer talent scouts during an in-situ talent identification environment. Study 1 developed a standardized coding-scheme to examine verbal cognitions during a single soccer game. Study 2 then utilized this methodology to examine two full-time recruitment staff trained in the use of concurrent verbal reporting before undertaking a live, in-game task. Participants also participated in a debrief interview following the game. The findings of the two studies suggest that developing a verbal reporting protocol is viable, however when applied in a live-game environment it is problematic. Future research should therefore consider a modified version of this task to further explore the cognitions of scouts whilst observing and identifying potential talent

Smoking among undergraduate students in the area of health Tabagismo entre acadêmicos da área de saúde

The aim of this study was to evaluate the relationship between smoking and socio-demographic and behavioral factors among undergraduate students in the area of health at the State University of Paraíba, Brazil. An analytical cross-sectional study was conducted with a representative sample from each of the following courses: Dentistry, Nursing, Psychology, Pharmacy, Physical Therapy and Physical Education. A total of 492 students were interviewed using a structured questionnaire. The chi-square and Fisher's Exact tests were used for statistical analysis at a 5% level of significance. Smoking prevalence was 5.7% and stress was the main reason for starting the habit (36.8%). In the multivariate analysis by logistic regression, the variables of gender, religious persuasion, semester attended in the course, and alcohol consumption were significantly associated with smoking (p<0.05). Although other studies reported a strong relationship between university students and smoking, the prevalence of smokers was low. Most of the variables studied revealed a correlation with smoking. Since smoking and alcohol consumption are the two major human addictions, this study suggests a bidirectional relationship between these variables.<br>Avaliar a relação entre o tabagismo e os fatores comportamentais e sociodemográficos entre acadêmicos da área de saúde da Universidade Estadual da Paraíba (UEPB). Foi realizado um estudo transversal analítico, no qual foi obtida uma amostra representativa de cada curso (Odontologia, Enfermagem, Psicologia, Farmácia, Fisioterapia e Educação Física). Foram entrevistados 492 alunos por meio de formulário estruturado. Os testes estatísticos utilizados foram Qui-quadrado e o Exato de Fisher (significância de 5%). A prevalência de tabagismo foi de 5,7% e o estresse foi a principal razão para o início do hábito (36,8%). Na análise multivariada por regressão logística as variáveis, sexo, prática de religião, período cursado e consumo etílico apresentaram-se associadas ao hábito de fumar (p<0,05). Apesar de estudos relatarem uma forte relação entre estudantes universitários e fumo, a prevalência de tabagismo foi baixa. A maioria das variáveis estudadas demonstrou associação com o hábito de fumar. Sendo o fumo e o álcool as duas maiores dependências humanas, este estudo sugere uma relação bidirecional entre estas variáveis

Marine bacterial community structure resilience to changes in protist predation under phytoplankton bloom conditions

To test whether protist grazing selectively affects the composition of aquatic bacterial communities, we combined high-throughput sequencing to determine bacterial community composition with analyses of grazing rates, protist and bacterial abundances and bacterial cell sizes and physiological states in a mesocosm experiment in which nutrients were added to stimulate a phytoplankton bloom. A large variability was observed in the abundances of bacteria (from 0.7 to 2.4 × 10 6 cells per ml), heterotrophic nanoflagellates (from 0.063 to 2.7 × 10 4 cells per ml) and ciliates (from 100 to 3000 cells per l) during the experiment (∼3-, 45- and 30-fold, respectively), as well as in bulk grazing rates (from 1 to 13 × 10 6 bacteria per ml per day) and bacterial production (from 3 to 379 μg per C l per day) (1 and 2 orders of magnitude, respectively). However, these strong changes in predation pressure did not induce comparable responses in bacterial community composition, indicating that bacterial community structure was resilient to changes in protist predation pressure. Overall, our results indicate that peaks in protist predation (at least those associated with phytoplankton blooms) do not necessarily trigger substantial changes in the composition of coastal marine bacterioplankton communities.Fil: Baltar, Federico. University of Otago; Nueva Zelanda. Linnaeus University; SueciaFil: Palovaara, Joakim. Linnaeus University; Suecia. University of Agriculture Wageningen; Países BajosFil: Unrein, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina. Consejo Superior de Investigaciones Científicas. Instituto de Ciencias del Mar; EspañaFil: Catala, Philippe. Universite Pierre et Marie Curie; Francia. Centre National de la Recherche Scientifique; FranciaFil: Horňák, Karel. Universitat Zurich; Suiza. Biology Centre of the Academy of Sciences of the Czech Republic; República ChecaFil: Šimek, Karel. Biology Centre of the Academy of Sciences of the Czech Republic; República ChecaFil: Vaqué, Dolors. Consejo Superior de Investigaciones Científicas. Instituto de Ciencias del Mar; EspañaFil: Massana, Ramon. Consejo Superior de Investigaciones Científicas. Instituto de Ciencias del Mar; EspañaFil: Gasol, Josep M.. Consejo Superior de Investigaciones Científicas. Instituto de Ciencias del Mar; EspañaFil: Pinhassi, Jarone. Linnaeus University; Sueci

Disentangling the relative influence of bacterioplankton phylogeny and metabolism on lysogeny in reservoirs and lagoons

Previous studies indicate that lysogeny is preponderant when environmental conditions are challenging for the bacterial communities and when their metabolism is reduced. Furthermore, it appears that lysogeny is more frequent within certain bacterial phylogenetic groups. In this comparative study from 10 freshwater reservoirs and 10 coastal lagoons, we aim to disentangle the influence of these different factors. In eight reservoirs and four lagoons, lysogeny was detected by induction assays with mitomycin C, and induction significantly modified the bacterial community composition (BCC), whereas community composition remained constant in ecosystems in which lysogeny was not observed. Among the phylogenetic groups studied, the most abundant ones were Bacteroidetes and α-proteobacteria in lagoons, and β-proteobacteria and Bacteroidetes in reservoirs. These dominant groups comprised the highest proportions of inducible lysogens. In order to unravel the effects of bacterial metabolism from phylogeny on lysogeny, we measured bacterial community physiology and the specific activities of selected phylogenetic groups. The proportion of inducible lysogens within the α- and the β-proteobacteria decreased with increasing group-specific metabolism in lagoons and reservoirs, respectively. In contrast, this relationship was not observed for the other lysogen-containing groups. Hence, both host physiology and phylogeny are critical for the establishment of lysogeny. This study illustrates the importance of lysogeny among the most abundant phylogenetic groups, and further suggests its strong structuring impact on BCC