Differential photosynthetic plasticity of Amazonian tree species in response to light environments.

To investigate how and to what extent there are differences in the photosynthetic plasticity of trees in response to different light environments, six species from three successional groups (late successional, mid-successional, and pioneers) were exposed to three different light environments [deep shade - DS (5% full sunlight - FS), moderate shade - MS (35% FS) and full sunlight - FS]. Maximum net photosynthesis (Amax), leaf N partitioning, stomatal, mesophile, and biochemical limitations (SL, ML, and BL, respectively), carboxylation velocity (Vcmax), and electron transport (Jmax) rates, and the state of photosynthetic induction (IS) were evaluated. Higher values of Amax, Vcmax, and Jmax in FS were observed for pioneer species, which invested the largest amount of leaf N in Rubisco. The lower IS for pioneer species reveals its reduced ability to take advantage of sunflecks. In general, the main photosynthetic limitations are diffusive, with SL and ML having equal importance under FS, and ML decreasing along with irradiance. The leaf traits, which are more determinant of the photosynthetic process, respond independently in relation to the successional group, especially with low light availability. An effective partitioning of leaf N between photosynthetic and structural components played a crucial role in the acclimation process and determined the increase or decrease of photosynthesis in response to the light conditions.

Spanish validation of the Stigma of Occupational Stress Scale for Doctors (SOSS-D) and factors associated with physician burnout.

OBJECTIVES: The aim of this study was to investigate the psychometric properties of the Spanish version of the Stigma of Occupational Stress Scale for Doctors (SOSS-D) and the factors associated with Physician Burnout in Paraguay. METHODS: Participants included 747 Paraguayan healthcare workers, aged 24-77 years old, of both sexes. SOSS-D was translated into Spanish and validated through an exploratory and confirmatory factor analysis. Participants were also scored with the Oldenburg Burnout Inventory (OLBI), the CAGE questionnaire, and the stigma subscale of the Perceived Barriers to Psychological Treatment (PBPT) measure. RESULTS: Three factors had a raw eigenvalue greater than 1, and explained 61.7% of total variance. The confirmatory analysis confirmed that the scale is three-dimensional. The model adjustment was good, according to all fit indices. OLBI results indicate clinically significant disengagement in 85.9% and clinically significant exhaustion in 91.6% of participants. Of the 747 participants, 57.6% reported alcoholic beverage consumption and among those, 19.3% had problematic alcohol consumption according to the CAGE questionnaire. The correlation between SOSS-D and the stigma subscale of the PBPT was statistically significant (r = 0.245, p < 0.001). CONCLUSIONS: The Spanish version of the SOSS-D was found to have good psychometric properties and adequately reproduces the three-dimensional model of the original English version.

Relationship between family history of alcohol problems and different clusters of depressive symptoms.

OBJECTIVES: Major depressive disorder (MDD) is a multifactorial syndrome with significant interactions between genetic and environmental factors. This study specifically investigates the association between family history of alcohol problems (FHAP) and family history of depression (FHD), and how these relate to different clusters of depressive symptoms. METHODS: Correlations between FHAP and FHD and different clusters of the Beck Depression Inventory (BDI) were studied. We sampled 333 employees from a general hospital who had been receiving a psychiatric consultation between 2005 and 2012. Analysis of variance (ANOVA) and Analysis of covariance (ANCOVA) models were conducted to explore these correlations. RESULTS: There was a significant positive correlation between FHAP and BDI affective score. This result remained significant even after the adjustment for other variables considered as important factors for MDD, such as gender, age, marital status, education, ethnic group and FHD. More specifically, FHAP was correlated with dissatisfaction and episodes of crying among the affective symptoms. FHAP showed no statistical difference in any of the other clusters score or in the BDI total score. Moreover, as expected, we found a correlation between FHD and BDI total score and Somatic and Cognitive clusters. CONCLUSION: FHAP should be routinely investigated in individuals presenting with depressive symptoms. This is especially important in cases presenting with dissatisfaction and episodes of crying in patients who do not endorse criteria for MDD. Due to study limitations, the findings require replication by neurobiological, epidemiological and clinical studies.

Psychometric properties of the Spanish version of the Fear of COVID-19 scale in Paraguayan population.

OBJECTIVE: The aim of this study is to test the psychometric properties of the Spanish validation of the Fear of COVID-19 Scale (FCV-19S) in a Paraguayan population. METHODS: Participants were recruited through an Internet-based survey. All participants whose scores in the Hospital Anxiety and Depression Scale (HADS) and The Fear Questionnaire (FQ) were greater than zero were included. 1245 subjects responded voluntarily: 1077 subjects, scoring >0, were considered. RESULTS: To establish construct validity of the FCV-19S, an exploratory factor analysis was performed using the KMO test, which was adequate, and the Bartlett sphericity test, which was significant (p <.0001). The CFI, NFI, GFI, TLI and RMSEA indices were used to evaluate the model and showed good adjustment. Cronbach's α showed valid internal consistency (α = 0.86). This validation was supported by significant correlation (p <.001) with the HADS scale for anxiety and depression and with the FQ scale for specific phobia. CONCLUSIONS: The Spanish version of the FCV-19S is a 7-item scale with two dimensions, psychological symptoms and physiological symptoms, which demonstrated robust psychometric properties in a Paraguayan population.

Cloxacillin nanostructured formulation for the treatment of bovine keratoconjunctivitis.

Infectious bovine keratoconjunctivitis (IBK) is a widespread, contagious ocular disease that affects cattle, especially dairy breeds. The disease is caused by Gram-negative bacteria mainly Moraxella bovis, and its treatment consists of parenteral or topic antibiotic therapy. The topic treatment approach is used more commonly in lactating cows, to avoid milk disposal. However, treatment failures are common, because the antibiotic is removed during lacrimation. This study aimed to evaluate the susceptibility of commercial cloxacillin and evaluate the efficacy of nanostructured cloxacillin in clinical cases of IBK by Moraxella. The minimum inhibitory concentration (MIC) of nanoparticle cloxacillin nanocoated, the nanoparticle without the antibiotic and the commercial cloxacillin were determined in vitro with field samples of Moraxella ovis (5) and Moraxella bovis (5). The efficiency of nanoparticles was tested in three cows naturally infected that were treated with 1.0 mL (with 0.32 mg of nanostructured cloxacillin) for the ocular route. Moraxella bovis was isolated and identified by biochemical and molecular methods before the treatment. The animals were treated every 12 h for six days. The cure was considered by the absence of clinical symptoms and bacteria after treatment. The mucoadhesive nanoparticle-based formulation promoted clinical cure with a low number of doses of antibiotics, probably due to the maintenance of the MIC in the ocular mucosa for longer due to the mucoadhesive characteristics of the nanoparticle. The results indicate that the use of nanocoated cloxacillin is possible to control infectious bovine keratoconjunctivitis.

Automatized and desktop AC-susceptometer for the in situ and real time monitoring of magnetic nanoparticles' synthesis by coprecipitation.

The main purpose of this work was to design, develop, and construct a simple desktop AC susceptometer to monitor in situ and in real time the coprecipitation synthesis of magnetic nanoparticles. The design incorporates one pair of identical pick-up sensing coils and one pair of Helmholtz coils. The picked up signal is detected by a lock-in SR850 amplifier that measures the in- and out-of-phase signals. The apparatus also includes a stirrer with 45°-angle blades to promote the fast homogenization of the reaction mixture. Our susceptometer has been successfully used to monitor the coprecipitation reaction for the synthesis of iron oxide nanoparticles.

Radiolabelling of ascorbic acid: a new clue to clarify its action as an anticancer agent?

Vitamin C exists in two forms: the reduced (ascorbic acid--AA) and oxidized form (dehydroascorbic acid--DHA). This is a nutrient whose benefits are long known and widely publicized, being most of them related to its antioxidant action. As an antioxidant, the main role of vitamin C is to neutralize free radicals, reducing oxidative stress. However, some controversial studies suggest that this nutrient may have a preventive and therapeutic role in cancer disease due to their possible pro-oxidant activity, promoting the formation of reactive oxygen species that can induce cell death in cancer cells. This factor, coupled with the decrease of antioxidant enzymes and increase of decompartmentalized transition metals in tumor cells may result in the selective cytotoxicity of vitamin C and the subsequent revelation of its therapeutic potential. In this way the first purpose of this work was radioactively label the reduced form of vitamin C with Tc-99m, its quality control by HPLC and the time stability. The second purpose was to use the radioactive complex 99mTc-AA in in vitro and in vivo studies in order to evaluate its uptake by colorectal cancer cells and biodistribution in mices, respectively. The results suggest that the pharmaceutical formulation developed, which was reproducible and stable over time, was residually taken up by colorectal cancer cells. Future studies are needed to deepen our understanding about the radioactive complex 99mTc-AA and clarify the mechanisms of action of vitamin C in oncologic disease.

Direct fibre simulation of carbon nanofibres suspensions in a Newtonian fluid under simple shear.

This work studies the effect of simple shear flows on the dispersion of carbon nanofibres (CNF) in a low viscosity Newtonian matrix. Analysis was performed by using a direct fibre simulation based on Particle Simulation Method (PSM) especially focusing on structure changes under shear flows. Suspensions of CNF/epoxy of different concentrations varying from 0.1 to 3.0 wt% were prepared by simple hand-mixing the as-received fibres with the epoxy resin. These suspensions were then subjected to different flow conditions (shear rates and strains) and their rheological behaviour was characterised. It is demonstrated that simulation can reproduce shear-thinning and structure developments induced by shear flow at different shear rates. Especially at low shear rates, flow induced helical bands were predicted by simulation, which was observed in experiments performed by other researchers and reported in the literature. From the results obtained it is concluded that the direct fibre simulator is a useful tool to design nano-scale fibre composites, allowing for optimisation of the critical parameters to determine the most adequate conditions leading to the required level of fibre dispersion.

Role of Yersinia pseudotuberculosis outer proteins (Yops) in murine humoral immune response.

The infection of mice with the wild-type (WT) strain of Y. pseudotuberculosis did not induce polyclonal activation of B lymphocytes. Suppression in the production of certain isotypes of Ig was observed, provoked mainly by YopH, YopJ and YpkA. The WT strain induced a progressive increase in the serum-specific IgG, which peaked after 4 weeks after infection, IgM being produced only after 1 week. Autoantibodies against phosphorylcholine, myelin, thyroglobulin and cardiolipin could be detected in the serum of mice infected with the WT strain. The infection of mice provoked suppression in the production of immunoglobulins by splenic B cells and that YopH, YopJ and YpkA must be involved here.

Method for automatic detection of wheezing in lung sounds.

The present report describes the development of a technique for automatic wheezing recognition in digitally recorded lung sounds. This method is based on the extraction and processing of spectral information from the respiratory cycle and the use of these data for user feedback and automatic recognition. The respiratory cycle is first pre-processed, in order to normalize its spectral information, and its spectrogram is then computed. After this procedure, the spectrogram image is processed by a two-dimensional convolution filter and a half-threshold in order to increase the contrast and isolate its highest amplitude components, respectively. Thus, in order to generate more compressed data to automatic recognition, the spectral projection from the processed spectrogram is computed and stored as an array. The higher magnitude values of the array and its respective spectral values are then located and used as inputs to a multi-layer perceptron artificial neural network, which results an automatic indication about the presence of wheezes. For validation of the methodology, lung sounds recorded from three different repositories were used. The results show that the proposed technique achieves 84.82% accuracy in the detection of wheezing for an isolated respiratory cycle and 92.86% accuracy for the detection of wheezes when detection is carried out using groups of respiratory cycles obtained from the same person. Also, the system presents the original recorded sound and the post-processed spectrogram image for the user to draw his own conclusions from the data.

Method for automatic detection of wheezing in lung sounds

The present report describes the development of a technique for automatic wheezing recognition in digitally recorded lung sounds. This method is based on the extraction and processing of spectral information from the respiratory cycle and the use of these data for user feedback and automatic recognition. The respiratory cycle is first pre-processed, in order to normalize its spectral information, and its spectrogram is then computed. After this procedure, the spectrogram image is processed by a two-dimensional convolution filter and a half-threshold in order to increase the contrast and isolate its highest amplitude components, respectively. Thus, in order to generate more compressed data to automatic recognition, the spectral projection from the processed spectrogram is computed and stored as an array. The higher magnitude values of the array and its respective spectral values are then located and used as inputs to a multi-layer perceptron artificial neural network, which results an automatic indication about the presence of wheezes. For validation of the methodology, lung sounds recorded from three different repositories were used. The results show that the proposed technique achieves 84.82% accuracy in the detection of wheezing for an isolated respiratory cycle and 92.86% accuracy for the detection of wheezes when detection is carried out using groups of respiratory cycles obtained from the same person. Also, the system presents the original recorded sound and the post-processed spectrogram image for the user to draw his own conclusions from the data.

Invasin of Yersinia pseudotuberculosis is not a polyclonal activator of mouse B lymphocytes

It is known that the invasin molecule of Yersinia pseudotuberculosis stimulates human peripheral B cells in vitro. In this work we evaluated the in vivo role ofinvasin as polyclonal activator of B lymphocytes in the mouse experimental model, by comparing strains of Y.pseudotuberculosis expressing invasin and isogenic inv mutants. Swiss mice were infected intravenously with two strains expressing invasin (YpIII pIB1 and an isogenic virulence plasmid-cured strain, YpIII) and with two invasin mutant strains (Yp100 pIB1 and Yp100, plasmid-cured). Spleen cells were sampled on days 7, 14, 21 and 28 after infection. Immunoglobulin (Ig)-secreting spleen cells were detected by protein A plaque assay and specific antibodies were detected in sera by ELISA. The virulent strain YPIII pIB1 (wild type) did not provoke polyclonal activation of B lymphocytes in vivo. In general, fewer Ig-secreting spleen cells of all isotypes were foundin the infected animals than in the control animals. Specific IgG antibodies were detected in the sera of animals infected with all strains. The peak response occurred on the 21st day post-infection, and the Yp100 strain provoked the highest level of these antibodies. We concluded that invasin is not a polyclonal activator of murine B cells.

Papel das Yops secretadas por Yersinia sobre a resposta imune do hospedeiro / Role of Yops secreted by Yersinia in the host immune response

O gênero Yersinia compreende três espécies patogênicas para humanos: Y. pestis, Y. enterocolitica e Y. pseudotuberculosis. A patogenicidade de Yersinia está ligada à presença do plasmideo de 70-kb (pYV) que é comum às três espécies e codifica um sistema de secreção do tipo III e um conjunto de proteínas de virulência, incluindo aquelas conhecidas como Yops (Yersinia outer proteins), que são exportadas por este sistema quando as células do hospedeiro são infectadas pela bactéria. Duas Yops translocadoras (YopB e YopD) se inserem na membrana plasmática e funcionam no transporte de seis efetoras (YopO, YopH, YopM, YopJ e YopT) para o citosol da célula do hospedeiro. As Yops efetoras funcionam interferindo em múltiplas vias de sinalização da célula infectada. Como consequência, a resposta imune inata e adaptativa do hospedeiro fica afetada. Este trabalho enfoca o papel das Yops na modulação da resposta imune do hospedeiro

Papel das proteínas "Yops" de Yersinia pseudotuberculosis na ativação do linfócitos B / Role of Yops of Yersinia pseudotuberculosis in B lymphocyte activation

O plasmídeo de virulência, comum às espécies patogênicas de Yersinia codifica um conjunto de proteínas secretadas denominadas Yops ("Yersinia outer proteins"). As "Yops" efetoras têm sido relacionadas e uma série de propriedades biológicas, incluindo resitência à fagocitose, citotoxicidade e desfosforilação de proteínas do hospedeiro. Porém, a associação das "Yops" de Yersinia com a resposta imune adaptativa do hospedeiro não está bem esclarecida. Yops secretadas por Yersinia enterocolitica O:3 provocam ativação policlonal de linfócitos B, quando inoculadas em camundongos. Neste trabalho, Yops secretadas po Y. pseudotuberculosis foram inoculadas por via intravenosa em camundongos Swiss livres de patógenos específicos (SPF), com objetivo de se verificar o papel in vivo destas proteínas sobre a ativação de linfócitos B esplênicos. Para tanto, foi determinada a cinética de células secretoras de imunoglobulinas inespecíficas e específicas dos diferentes isotipos (IgG, IgM e IgA), pela técnica de ELISPOT e pesquisada a presença de anticorpos específicos anti-Yersinia nos soros dos animais inoculados, através de ELISA. Foi verificado que ocorreu um aumento significativo apenas no número de linfócitos secretores de Igs inespecíficas do isotipo IgG no 21º dia poó-inoculação (aumento de 2,5 vezes em relação aos controles). O número de linfócitos secretores dos outros isotipos foi semelhante aos controles, com exceção de IgA, que sofreu uma diminuição de 3,1 vezes no 7º dia pós-inoculação. Quanto às células secretoras de imunoglobulinas específicas, a resposta dos animais inoculados foi muito individual. Em alguns camundongos inoculados, foram detectadas células secretoras de Igs anti-Yersinia do isotipo IgG, no 7º e 14º dia pós-inoculação e do isotipo IgM, no 7º e 28º dia pós-inoculação. Por outro lado, foram detectados anticorpos séricos anti-Yersinia foram detectados apenas no 7º dia pós-inoculação. Estes resultados demonstram que existe uma diferença na capacidade imunomoduladora das Yops secretadas por Y.pseudotuberculosis e Y.enterocolitica.

The importance of connections: joining components of the Hutterite pedigree.

We analyzed a quantitative trait (serum IgE levels), and a binary trait (asthma), in four Hutterite sub-pedigrees. A genome screen for asthma was performed using GENEHUNTER, and interesting regions were followed up using extended pedigrees and the FASTLINK package. Markov chain Monte Carlo (MCMC) methods were used to assess haplotype sharing among affected individuals (MORGAN/AUTOZYG), and to perform a combined oligogenic segregation and linkage analysis (LOKI) for log10(IgE). We found evidence for at least two susceptibility loci for asthma on chromosome 5, and a QTL for log10(IgE) on chromosome 1. Our analyses demonstrate that using the most complete pedigree structure possible is advisable, with attention to the possibility of heterogeneity among subunits of a very large pedigree.