Abstract Water stress limits the initial growth and development of maize mass and grain, as well as the physiological process for absorbing the amount of mineral elements. The objective was to evaluate the effect of silicon on germination and growth of corn seedlings submitted to water deficit. The experiment was carried out in the laboratory and the experimental design was completely randomized (factorial 3 × 4), with three concentrations of calcium silicate (0.0; 1.0 and 2.0 mM) and 4 solutions of PEG-6000 to simulate different osmotic potentials (0, 0; -0.3; -0.6; -0.9 MPa). Germination percentage, germination speed index (GSI), mean germination time (MGT), percentage of non-germinated and abnormal germinated, length and dry matter of shoot, root and total seedlings were evaluated. Water deficiency reduced the parameters TG, GSI and MGT. The water deficit reduce the MSPA, MSR and MST with more than 80% reduction in mass from seedlings without deficiency to seedlings with deficiency. For CPA, CR and CT there was a reduction of at least 87%, 70% and 77%, respectively, among seeds without deficiency compared to seeds submitted to deficiency. The use of silicon in corn seeds did not attenuate the stress caused by water deficit simulated by PEG-6000.

Resumo O estresse hídrico limita o crescimento inicial e o desenvolvimento da massa e do grão de milho, assim como no processo fisiológico para a absorção da quantidade de elementos minerais. Objetivou-se avaliar o efeito do silício na germinação e no crescimento de plântulas de milho submetidas a deficiência hídrica. O experimento foi desenvolvido em laboratório e o delineamento experimental foi inteiramente casualizado (DIC) (fatorial 3 × 4), sendo três concentrações de Silicato de cálcio (0,0; 1,0 e 2,0 mM) e 4 soluções de PEG-6000 a simular diferentes potenciais osmóticos (0,0; -0,3; -0,6; -0,9 MPa). Foram avaliados a porcentagem de germinação, o índice de velocidade de germinação (IVG), o tempo médio de germinação (TMG), a porcentagem de não germinadas e de germinadas anormais, o comprimento e matéria seca da parte aérea, raiz e total das plântulas. A deficiência hídrica diminuiu os parâmetros TG, IVG e TMG. O déficit hídrico reduz a MSPA, MSR e MST com mais de 80% de redução da massa das plântulas sem deficiência para as plântulas com deficiência. Para CPA, CR e CT houve redução de, no mínimo, 87%, 70% e 77%, respectivamente entre as sementes sem deficiência em comparação as sementes submetidas a deficiência. A utilização de silício em sementes de milho não atenuou o estresse causado pela deficiência hídrica simulada por PEG-6000.

Neste trabalho, apresentaremos experimentos portáteis no intuito de abordar os conceitos da indução eletromagnética com alunos do Ensino Básico. Os materiais utilizados para a realização dos experimentos são de fácil aquisição e o conjunto deles pode ser adquirido na forma de um kit, facilmente transportável. A proposta é que os alunos aprendam os conceitos por meio de discussão em sala e da execução de experimentos. Para isso, será dado maior destaque às aulas interativas em detrimento das expositivas. Assim, nos inspiramos na metodologia desenvolvida pelo grupo da Universidade de Rutgers, liderado pela professora Eugenia Etkina. A fundamentação dessa proposta é que os alunos estudem e aprendam os conceitos físicos de forma semelhante à forma que os cientistas trabalham para construir o conhecimento científico. Tal metodologia foi denominada “Investigative Science Learning Environment” (ISLE). Desta feita, os alunos são apresentados ao método científico, ainda no Ensino Médio, de forma concreta, em que a observação, a proposição e a refutação de hipóteses são fundamentais para a criação de um modelo para o fenômeno físico estudado. Para avaliar a metodologia e os experimentos portáteis, apresentamos uma proposta de sequência didática a ser aplicada em uma turma da terceira śerie do Ensino Médio.

In this paper we will present a portables experiments in order to approach the concepts of electromagnetic induction to Basic Education students. The materials used to perform the experiments are easy to acquire, and the set of them can be purchased in the form of an experimental kit, easily transportable. The proposal is that students learn the concepts through classroom discussion and the execution of experiments, with greater emphasis on interactive classes over lectures. For this, we were inspired by the methodology developed by the group from Rutgers University, led by Professor Eugenia Etkina. The foundation of this proposal is that student’s study and learn physical concepts similar to the way scientists work to setup scientific knowledge. Such methodology was called “Investigative Science Learning Environment” (ISLE). In this method, students are introduced to the scientific method, in high school, in a concrete way where observation, proposition and refutation of hypotheses are fundamental for creating a model for the physical phenomenon studied. To evaluate the methodology and use of the portable experiment, we present a proposal for a didactic sequence to be applied to a twelve-year high school class.

Resumo A degradação termocatalítica do polietileno (PE) e do polietileno de ultra alto peso molecular (UHMWPE) foi estudada na presença de zeólitas (ZSM-5, ZSM-22 e ferrierita) com diferentes sistemas de poros e propriedades texturais. As zeólitas foram misturadas fisicamente aos polímeros na proporção de 30% em massa e submetidas à análise termogravimétrica nas taxas de aquecimento de 5, 10, 20 e 30 °C.min-1. A energia de ativação do processo de degradação foi determinada pelo método de Flynn-Wall-Ozawa. A adição das zeólitas aos polímeros reduziu consideravelmente a temperatura de degradação. A ZSM-22 demonstrou maior eficiência na degradação do PE por apresentar menor tamanho de cristalito, promovendo um caminho difusional mais curto para os fragmentos de polímero provenientes da superfície. A ferrierita apresentou menor nível de energia na degradação do UHMWPE, mostrando a necessidade da sinergia entre a acessibilidade da estrutura e a acidez do catalisador para promover a quebra desse polímero.

Abstract The thermo-catalytic degradation of polyethylene (PE) and ultra-high molecular weight polyethylene (UHMWPE) was studied in the presence of zeolites (ZSM-5, ZSM-22, and ferrierite) with different pore systems and textural properties. The zeolites were physically mixed with polymers in the proportion of 30 wt% and submitted to thermogravimetric analysis at heating rates of 5, 10, 20, and 30 °C.min-1. The activation energy of the degradation process was determined using the Flynn-Wall-Ozawa method. The addition of zeolites to polymers has considerably reduced the temperature of degradation. ZSM-22 demonstrated greater efficiency in the degradation of PE because it has a smaller crystallite size, promoting a shorter diffusional path for the polymer fragments coming from the surface. Ferrierite showed a lower energy level in the degradation of UHMWPE, showing the need for synergy between the accessibility of the structure and acidity of the catalyst to promote the cracking of this polymer.

RESUMO Enquadramento: A sintomatologia musculosquelética afeta muitos indivíduos, independentemente da sua idade, sexo e contexto socioeconómico. Os estudantes de enfermagem, desde que iniciam a sua formação vivenciam condições de trabalho semelhantes às do enfermeiro, com a mesma exposição aos fatores que podem desencadear a sintomatologia musculosquelética. Objetivo: Identificar a prevalência e os fatores de risco da patologia musculosquelética nos estudantes do curso de licenciatura em enfermagem. Material e Métodos: Revisão sistemática da literatura, com pesquisa na plataforma EBSCOHost®, CINAHL, MEDLINE e BVS, no período de janeiro de 2010 a março 2019. Os descritores utilizados foram: (Students, nursing AND Musculoskeletal diseases OR Musculoskeletal disorders AND Prevalence). Resultados e Discussão: Obteve-se um total de nove artigos que cumprem os critérios estabelecidos. A sintomatologia que foi auto reportada pelos estudantes de enfermagem teve maior prevalência na região cervical, seguida pela região lombar e dorsal, punho, ombros e mãos. Destacam ainda que os estudantes apresentam sintomatologia musculoesquelética em, pelo menos, uma região corporal. Os parâmetros que mais contribuíram para esta questão foram o género feminino, idade, esforços repetitivos, movimentação manual de cargas, ansiedade e stress académico desde o primeiro ano. A maioria dos artigos sugere que os estudantes de enfermagem estão expostos, desde o início do curso, aos mesmos riscos que foram identificados nos enfermeiros. Conclusões: A taxa de prevalência e os fatores associados da sintomatologia musculosquelética identificados sugere a necessidade de uma intervenção nos estudantes de enfermagem logo desde o início do curso. É necessário capacitá-los com conhecimentos para a prevenção e minimização desta problemática que tem repercussões no seu futuro profissional e bem-estar geral. Só com a contribuição de vários agentes de saúde pública conseguiremos travar esta situação. Assim, sugere-se a utilização de estratégias de saúde ocupacional tais como a promoção de exercício físico, rastreios de saúde, gestão de ansiedade e stress, bem como melhorias das condições de sala de aula, de forma a contribuir para o bem-estar tanto a nível físico como mental destes estudantes e, posteriormente, de futuros enfermeiros.

ABSTRACT Background: Musculoskeletal symptoms affect many individuals regardless of gender, age and socioeconomic context. Early in their clinical training, nursing students experience working conditions similar to nurses, and are also exposed to the same situations and risks that can trigger musculoskeletal symptomatology. Objective: To identify the prevalence and risk factors of musculoskeletal symptomatology in undergraduate nursing students. Materials and Methods: A systematic literature review was performed in the following platforms: EBSCOHost®, CINAHL, MEDLINE and BVS, from January to March 2019. The descriptors used were: Students, Nursing AND Musculoskeletal diseases OR Musculoskeletal disorders AND Prevalence). Results and Discussion: Nine articles that met the established criteria were selected. The most frequently self-reported symptomatology was in the cervical and neck region followed by the lumbar and dorsal region, wrist, shoulders and hands. All articles underlined the fact that students report musculoskeletal symptoms in at least one of the body regions. Factors that contributed more often to this were repetitive efforts, manual handling tasks, gender, older age, anxiety and academic stress accumulated since the 1st year. Most studies suggested that nursing students are exposed to the same risks identified by nursing professionals. Conclusions: This study shows that the prevalence and risk factors of musculoskeletal symptomatology identified in nursing students must be minimized and prevented from the 1st year of the course. We need to provide students with the knowledge and strategies to tackle this problem and the repercussion it may have on their professional life and well-being. We only be able to cope with this situation by having the contribution of several public health agents. Therefore, it is suggested to use occupational health strategies such as promoting physical exercise, health screening, managing anxiety and stress and improving classroom conditions, in order to contribute to both mental and physical well-being of nursing students and, in the future, professional nurses.

Resumo A estrutura da ictiofauna em rios neotropicais é constantemente influenciada por fatores ambientais, espaciais e/ou temporais, uma vez que as espécies tendem a ocupar ambientes com condições favoráveis à sua sobrevivência. Dessa forma, esta pesquisa tem como objetivo responder qual o principal fator responsável pela estruturação das assembleias de peixes no Médio Rio Xingu, testando a influência dos fatores ambientais, espaciais e temporais, além da presença de barreiras naturais (cachoeiras). Os dados foram coletados, trimestralmente, entre os meses de julho de 2012 e abril de 2013, utilizando redes de emalhe de tamanhos de malha variados. Foram mensuradas 17 variáveis ambientais. Foram coletados 8.485 indivíduos distribuídos em 188 espécies. Observou-se que sólidos dissolvidos totais, condutividade, material em suspensão total e oxigênio dissolvido foram as variáveis que mais influenciaram a ictiofauna do médio Rio Xingu. Observou-se que apenas as barreiras naturais e os períodos hidrológicos foram determinantes, ocorrendo tanto variação longitudinal quanto lateral, ficando claro que a conectividade entre os diferentes trechos do médio rio Xingu é de suma importância na estruturação das assembleias de peixes.

Abstract The structure of fish assemblages in Neotropical rivers is influenced by a series of environmental, spatial and/or temporal factors, given that different species will occupy the habitats that present the most favourable conditions to their survival. The present study aims to identify the principal factors responsible for the structuring of the fish assemblages found in the middle Xingu River, examining the influence of environmental, spatial, and temporal factors, in addition to the presence of natural barriers (waterfalls). For this, data were collected every three months between July 2012 and April 2013, using gillnets of different sizes and meshes. In addition to biotic data, 17 environmental variables were measured. A total of 8,485 fish specimens were collected during the study, representing 188 species. Total dissolved solids, conductivity, total suspended matter, and dissolved oxygen concentrations were the variables that had the greatest influence on the characteristics of the fish fauna of the middle Xingu. Only the barriers and hydrological periods played a significant deterministic role, resulting in both longitudinal and lateral gradients. This emphasizes the role of the connectivity of the different habitats found within the study area in the structuring of its fish assemblages.

It has been proposed that the subgenus Archaeotityus comprises the most ancient species group within the medically important scorpion genus Tityus. cDNA encoding sodium-channel active toxins from the type species of this subgenus, Tityus clathratus (central Venezuela), have been isolated and sequenced. Two cDNAs were retrieved that encoded 61 amino acid-long putative neurotoxins named Tcl1 and Tcl2. Sequence identity was highest (87%) when both were compared with β-toxin Ts1 from the Brazilian scorpion Tityus serrulatus and its homologs from T. bahiensis, T. stigmurus, and T. costatus. A Bayesian analysis indicated statistical support for the grouping of T. clathratus Tcl1 and Tcl2 with Brazilian gamma-like β-toxins, reinforcing previous phylogenetic studies which suggested an evolutionary relationship between the subgenus Archaeotityus and scorpion species inhabiting southeast South America belonging to the subgenus Tityus.

The prominent myotoxic effects induced by Bothrops jararacussu crude venom are due, in part, to its polycationic myotoxins, BthTX-I and BthTX-II. Both myotoxins have a phospholipase A2 structure: BthTX-II is an active enzyme Asp-49 PLA2, while BthTX-I is a Lys-49 PLA2 devoid of enzymatic activity. In this study, the effect of low-level laser therapy (LLLT), 685 nm laser at a dose of 4.2 J/cm2 on edema formation, leukocyte influx and myonecrosis caused by BthTX-I and BthTX-II, isolated from Bothrops jararacussu snake venom, was analyzed. BthTX-I and BthTX-II caused a significant edema formation, a prominent leukocyte infiltrate composed predominantly by neutrophils and myonecrosis in envenomed gastrocnemius muscle. LLLT significantly reduced the edema formation, neutrophil accumulation and myonecrosis induced by both myotoxins 24 hours after the injection. LLLT reduced the myonecrosis caused by BthTX-I and BthTX-II, respectively, by 60 and 43%; the edema formation, by 41 and 60.7%; and the leukocyte influx, by 57.5 and 51.6%. In conclusion, LLLT significantly reduced the effect of these snake toxins on the inflammatory response and myonecrosis. These results suggest that LLLT should be considered a potential therapeutic approach for treatment of local effects of Bothrops species venom.

Introduction: The physical activity and adequate food plays a key role in improving health and the control of diseases. Objective: This paper aims at determining the nutritional state through antropometric measures, socioeconomic level, the most common illnesses and type of physical activity, beyond food consumption and the place where meals are taken, of under-graduate students of the Nutrition course in UFPE. Methods: The sample is constituted of 68 female students, of different periods and at ages between 18 and 27 years old. The process of selection of the sample was for convenience. The students voluntarily participated and answered three questionnaires, respectively, on their socioeconomic level (income of the family) and possible illnesses they had, measures of the cutaneous folds and type of practiced physical activity; register of consumed foods and local where the meals were carried. Statistical analysis was performed by absolute frequency, percentage, average and standard deviation. The margin of error used in the testing employees was 5%. Results: In relation to the incomes, they had predominated above three minimum wages (86%), the parents have a predominant role in the expenditure of their study (46%), followed by the father (24%), mother (9%), husband (4%), other responsible ones (10%); 7% did not give information. The most common illnesses were: allergic rinite, tonsilitis, sleeplessness and intestinal constipation. The weight, the height, the index of body mass and the relation waist hip of the students were within normal standards. The abdominal circumference varied only in 2.57 cm between the studied age range. In relation to the practice of physical activities, 67% were sedentary, 20% practiced light activity and 13% moderate. In relation to where the meals are had, breakfast, in its majority (76%), was carried at home, followed by supper (56%), while lunch (41%) and snack 1 (34%), at University. Among the pupils who did not inform the place where they had their meals there was a high percentage for the big meals and a small one for the minor ones. The main kinds of consumed meals were breakfast, lunch and supper (98%). For the small meals, the values were: snack 1 (54%), snack 2 (61%), snack 3 (45%). The analysis of food consumption for three days disclosed ingestion of energy with deficit of 21% in relation to the recommended one (p < 0.001); the macro-nutrients showed percentages within the standards; the intake of fiber (11.8 g/day) was less than recommended (p < 0.001). Meat, eggs and cereals were ingested daily (for about 80%); vegetables (40%), legumes, fruits and candies (25% 30%), around four or six days a week. Roots and tubercles, salty, embedded and non alcoholic drinks were consumed from one to three days weekly (70%). Animal guts were not consumed by 50% of the studied population. Conclusions: Having analyzed all this, the studied students need to modify their food habits, acquiring knowledge on the importance of a balanced diet, as well as the practice of physical activity systematically, to prevent illnesses and attain a better quality of life.

Introducción: La actividad física y una alimentación adecuada ejercen un papel esencial al perfeccionamiento de la salud y al control de enfermedades. Objetivo: El objetivo de este trabajo ha sido determinar el estado nutricional a través de medidas antropométricas, nivel socioeconómico, enfermedades más comunes y tipo de actividad física, además del consumo alimentario y el lugar donde son realizadas las comidas de los estudiantes de Graduación en Nutrición de la UFPE. Material y métodos: La muestra se ha constituido de 68 alumnas del Curso de Nutrición, de distintos períodos escolares y con edades entre 18 y 27 años. El proceso de selección de la muestra ha sido por conveniencia. Las estudiantes han participado voluntariamente y han contestado a tres cuestionarios, respectivamente, sobre el nivel socioeconómico (renta familiar) y posibles enfermedades que padecían, medidas de los pliegues cutáneos y tipo de actividad física practicada; registro de los alimentos consumidos y lugar donde las comidas eran realizadas. El análisis estadístico se ha realizado a través de frecuencias absolutas, porcentuales, promedios y desvío estándar. El margen de error utilizado en los tests empleados ha sido de 5%. Resultados: En cuanto a los rendimientos, han predominado los superiores a tres sueldos mínimos (86%), los padres tienen un papel determinante en el costeo del estudio (46%), seguido del padre (24%), madre (9%), marido (4%), otros responsables (10%); el 7% no han dado información. Las enfermedades más comunes eran: rinitis alérgica, amigdalitis, insomnio y constipación intestinal. El peso, estatura, el índice de masa corporal y la relación cintura cadera de las estudiantes seguían los patrones normales. La circunferencia abdominal ha variado en solo 2,57 cm entre los grupos etarios investigados. En cuanto a la práctica de actividades físicas, el 68% eran sedentarias, el 20% practicaban actividad leve y el 13% moderada. Sobre el lugar de realización de las comidas, el desayuno, en su mayoría (76%), era realizado en casa, seguido de la cena (56%). Mientras que el almuerzo (41%) y la merienda 1 (34%), en la Universidad. Entre las alumnas que no han informado del lugar en el que hacían las comidas ha habido un porcentaje mayor para las grandes y menor para las pequeñas comidas. Los tipos principales de comidas consumidas han sido desayuno, almuerzo y cena (98%). Para las pequeñas comidas, los valores han sido: merienda 1 (54%), merienda 2 (61%), merienda 3 (45%). El análisis del consumo alimentario por tres días ha revelado ingestión de energía con déficit del 21% en relación a lo recomendado (p < 0,001); los macronutrientes han presentado porcentajes de acuerdo con los patrones; el consumo de fibras (11,8 g/día) ha sido inferior a lo recomendado (p < 0,001). Carne, huevos y cereales eran ingeridos diariamente (cerca del 80%); verduras (40%), leguminosas, frutas y dulces (25 a 30%), durante cuatro a seis días por semana. Raíces y tubérculos, salados, embutidos y bebidas no alcohólicas eran consumidos de uno a tres días semanales (70%). Las vísceras no han sido consumidas por el 50% de la población investigada. Conclusiones: Por lo expuesto, el grupo de alumnos estudiado necesita cambiar sus hábitos alimentarios, concienciándose sobre la importancia de una comida equilibrada, así como realizar sistemáticamente actividad física, para prevención de enfermedades y obtención de una mejor calidad de vida.

This work reports the second record of the scorpion Tityus bahiensis Perty from Venezuela. The specimen was found alive in a wardrobe at a hotel resort in Margarita Island, northeastern Venezuela. Morphological characterization allowed its assignment to the Tityus bahiensis population inhabiting the southernmost area of the species' geographic range, e.g. the state of São Paulo in Brazil, northern Argentina and Paraguay. The fact that the only available Venezuelan antiscorpion (anti-Tityus discrepans) serum does not neutralize the effects of alpha- and beta-toxin from Tityus serrulatus venom (which resembles in composition that of T. bahiensis) constitutes a warning to local clinicians confronted with envenomations by noxious species transported to Venezuela from Brazil by human agency.

The aim of the present study was to evaluate the prevalence of HEV, TTV and GBV-C/GBV-C/HGV in patients with acute viral hepatitis A, B and non-A-C. We evaluated sera of 94 patients from a sentinel program who had acute hepatitis A (N = 40), B (N = 42) and non-A-C (N = 12); 71 blood donors served as controls. IgM and anti-HEV IgG antibodies were detected by enzyme immunoassay using commercial kits. TTV and GBV-C/HGV were detected by nested PCR; genotyping was done by sequencing and phylogenetic analysis. Anti-HEV IgG was present in 38, 10 and 17% of patients with hepatitis A, B and non-A-C. Four patients with hepatitis A and 1 with non-A-C hepatitis also had anti-HEV IgM detected in serum. TTV was detected in 21% of patients with acute hepatitis and in 31% of donors. GBV-C/HGV was detected in 9% of patients with hepatitis, and in 10% of donors. We found TTV isolates of genotypes 1, 2, 3, and 4 and GBV-C/HGV isolates of genotypes 1 and 2. Mean aminotransferase levels were lower in patients who were TTV or GBV-C/HGV positive. In conclusion, the detection of anti-HEV IgM in some acute hepatitis A cases suggests co-infection with HEV and hepatitis E could be the etiology of a few cases of sporadic non-A-C hepatitis in Salvador, Brazil. TTV genotype 1, 2, 3 and 4 isolates and GBV-C/HGV genotype 1 and 2 strains are frequent in the studied population. TTV and GBV-C/HGV infection does not appear to have a role in the etiology of acute hepatitis.

Tityus gonzalespongai n. sp. is a species endemic to the high mountains of Anzoátegui State, Venezuela. It is found between 1,600 and 2,200 m in ''La Laguna'' mountain. Its habitat includes the area of ''Bosque Húmedo Montano Bajo'' with the type of vegetation of ''Bosque Ombrófilo Montano Siempreverde'' (''Bosques Nublados Costeros'' that includes the ''Subpáramos Arbustivos''). It is distinguished from other Tityus species (T. caripitensis, T. monaguensis, and T. nororientalis) by the following characteristics: 1- the disposition of the trichobothria in the pedipalps; 2- ventral keels of the caudal segments of the metasoma (segment II, double and parallel in the proximal two thirds, then convergent and finally divergent in the base; segments III and IV, double and parallel in the basal third, then convergent in a single keel that divides in the base); 3- the number of lines of denticles of the movable finger of the right pedipalp (male = 14; female = 14); 4- pectineous teeth (right/left: male = 15/15: female = 16/15); 5- color: movable and fixed fingers dark brown; prosoma and metasoma, ochre; caudal segment IV, slightly darker than the previous ones; V and the telson, dark brown. T. gonzalespongai belongs to the ''androcottoides'' group and presents a marked sexual dimorphism. It is the first species of the Tityus genus described and reported in Anzoátegui State, expanding this taxa distribution in Venezuela.