AVALIAÇÃO DE DIFERENTES FONTES E NÍVEIS DE SELÊNIO PARA FRANGOS DE CORTE EM DIFERENTES TEMPERATURAS

Foram avaliados os parâmetros zootécnicos de frangos de corte alimentados com dietas suplementadas com diferentes fontes e níveis de selênio (Se), criados sob diferentes condições de temperatura. Foram utilizados 720 pintainhos, Cobb-500, em um delineamento inteiramente ao acaso em esquema fatorial 3 x 2 x 2 (3 temperaturas ambiente: termoneutra, fria e quente; 2 níveis de suplementação de Se: nível A e B; e 2 fontes de Se: orgânica e inorgânica), com 4 repetições de 15 aves. Os níveis A e B de Se na ração inicial (1 a 21 dias) e de crescimento (22 a 42 dias) foram 0,15 e 0,30 mg/kg e 0,20 e 0,40 mg/kg, respectivamente. Selenometionina foi usada como fonte de Se orgânico e selenito de sódio, inorgânico. Os frangos criados em condições de estresse por calor apresentaram uma redução no consumo de ração e ganho de peso. Não houve influência da suplementação das diferentes fontes ou níveis de Se no ganho de peso, consumo de ração ou conversão alimentar. Os resultados são indicativos de que a suplementação de Se não melhora o desempenho de frangos de corte criados em condições de temperatura adversa. Evaluation of different sources and selenium levels for broilers at different temperatures Abstract This study evaluated the effect of selenium (Se) diet supplementation on productive parameters of broiler chickens raised under different temperatures, in a complete randomized design with 3 x 2 x 2 factorial schedule (3 environmental temperatures: cold, neutral and hot; 2 levels and two Se sources) with 4 repetitions of 15 birds. The levels of Se in rations for initial and growth phases were: 0.15 and 0.30 mg/kg; and 0.20 and 0.40 mg/kg, respectively. The organic and inorganic sources of selenium were selenomethionine and sodium selenite, respectively. There were a reducing in broiler feed intake and weight gain of the broilers housed in the hot temperature. Selenium levels or sources did not affect the weight gain, feed intake or feed conversion. It was concluded that Se supplementation did no affect the broiler performance, housed under adverse environmental temperature

Frequency, diversity, and productivity study on the Aedes aegypti most preferred containers in the City of Manaus, Amazonas, Brazil

The most preferred containers by Aedes aegypti were studied April and July (rainy and dry periods) in two Manaus neighbourhoods. In all, 2,700 premises and 13,912 containers were examined, most (87%) recorded outdoors. Out of the 13,100 inspected premises, only 1.6% showed to be positive for Aedes aegypti, summing up to 7,916 collected samples. Most frequently found containers outdoors in either neighbourhood regardless of rain or dry period were Bottles flasks and Storage, and indoors, Fixed, Flowerpots, and buckets. Productivity was estimated according to the number of premises and positive containers investigated, showing the actual container groups productivity. Considering both rainy and dry periods outdoors at Praça 14 the groups of Tyre, Flask, Bottle, Construction Equipment and Fixed, had the highest averages respectively. Construction Equipment and Flask groups were the most productive in Coroado in April. Flask, Construction Equipment and Storage groups stood out in July

A promising action of riboflavin as a mediator of leukaemia cell death

Besides having a pivotal biological function as a component of coenzymes, riboflavin appears a promissing antitumoral agent, but the underlying molecular mechanism remains unclear. In this work, we demonstrate that irradiated riboflavin, when applied at microM concentrations, induces an orderly sequence of signaling events finally leading to leukemia cell death. The molecular mechanism involved is dependent on the activation of caspase 8 caused by overexpression of Fas and FasL and also on mitochondrial amplification mechanisms, involving the stimulation of ceramide production by sphingomyelinase and ceramide synthase. The activation of this cascade led to an inhibition of mitogen activated protein kinases: JNK, MEK and ERK and survival mediators (PKB and IAP1), upregulation of the proapoptotic Bcl2 member Bax and downregulation of cell cycle progression regulators. Importantly, induction of apoptosis by irradiated riboflavin was leukaemia cell specific, as normal human lymphocytes did not respond to the compound with cell death. Our data indicate that riboflavin selectively activates Fas cascade and also constitutes a death receptor-engaged drug without harmful side effects in normal cells, bolstering the case for using this compound as a novel avenue for combating cancerous diseas

Threat bias in attention orienting: evidence of specificity in a large community-based study

Background: Preliminary research implicates threat-related attention biases in pediatric anxiety disorders. However, major questions exist concerning diagnostic specificity, effects of symptom-severity levels, and threat-stimulus exposure durations in attention paradigms. This study examines these issues in a large, community school-based sample.Methods: A total of 2,046 children (ages 6-to-12) were assessed using the Development and Well Being Assessment (DAWBA), Childhood Behavior Checklist (CBCL) and dot-probe tasks. Children were classified based on presence or absence of “fear-related” disorders, “distress-related” disorders, and behavior disorders. Two dot-probe tasks, which differed in stimulus exposure, assessed attention biases for happy-face and threat-face cues. The main analysis included 1774 children.Results: For attention bias scores, a three-way interaction emerged among face-cue emotional valence, diagnostic group, and internalizing-symptom severity (F=2.87, p<0.05). This interaction reflected different associations between internalizing symptom severity and threat-related attention bias across diagnostic groups. In children with no diagnosis (n=1411; mean difference=11.03; SE=3.47, df=1, p<0.001) and those with distress-related disorders (n=66; mean difference=10.63; SE=5.24, df=1, p<0.05), high internalizing symptoms predicted vigilance towards threat. However, in children with fear-related disorders (n=86; mean difference=-11.90; SE=5.94, df=1; p<0.05), high internalizing symptoms predicted an opposite tendency, manifesting as greater bias away from threat. These associations did not emerge in the behavior-disorder group (n=211). Conclusions: The association between internalizing symptoms and biased orienting varies with the nature of developmental psychopathology. Both the form and severity of psychopathology moderates threat-related attention biases in children

Níveis de proteína e de arginina digestível na ração pré-inicial de frangos de corte Protein and digestible arginine levels in pre-starter broiler rations

O experimento foi conduzido para avaliar níveis de proteína bruta e arginina digestível na ração pré-inicial de frangos de corte e seus efeitos no desempenho das aves dos 7 aos 21 dias de idade. Foram utilizados 600 pintos da linhagem Cobb 500, distribuídos em delineamento de blocos casualizados em esquema fatorial 4 × 2, composto de quatro níveis de arginina digestível (1,363; 1,463; 1,563 e 1,663%) e dois níveis de proteína bruta (20 e 22%), totalizando oito tratamentos, cada um com cinco repetições de 15 aves. Avaliaram-se o ganho de peso, o consumo de ração, o índice de conversão alimentar, a biometria dos órgãos do trato gastrintestinal e a digestibilidade e retenção de matéria seca e nitrogênio. O maior ganho de peso na fase de 1 a 14 dias de idade foi obtido com a ração com 22% de proteína bruta. Os níveis de arginina digestível tiveram efeito quadrático na conversão alimentar na fase de 1 a 10 dias de idade. O peso do esôfago e inglúvio foi maior nas aves alimentadas com a ração com 20% de proteína bruta, no entanto, houve efeito quadrático dos níveis de arginina digestível sobre o comprimento do intestino aos 10 dias de idade e sobre o peso do esôfago + inglúvio aos 3 dias de idade. Houve interação entre os níveis de proteína bruta e arginina digestível para o peso relativo do fígado aos 14 dias, que respondeu de forma quadrática ao nível de 20% de proteína bruta, e para o comprimento de intestino, cujo maior valor foi obtido com os níveis de 22% de proteína bruta e 1,603% de arginina digestível. O balanço e a retenção de nitrogênio foram maiores no nível de 22% de proteína bruta. O nível de 1,363% de arginina digestível atende às exigências nutricionais dos frangos de corte na fase pré-inicial.<br>This experiment was carried out to evaluate levels of crude protein and digestible arginine in pre-starter broiler ration and their effects on the performance of the broilers from 7 to 21 days of age. A total of 600 Cobb chicks was assigned to a block randomized design in a 4 × 2 factorial arrangement consisting of 4 levels of digestible arginine (1.363; 1.463; 1.563 and 1.663%) and two levels of crude protein (20 and 22%) with eight treatments, each one with five replicates of 15 broilers each. For the experiment, weight gain, feed intake, feed conversion ratio, gastrointestinal biometry, digestibility and retention of dry matter and nitrogen were evaluated. The highest weight gain from 1 to 14 days old was obtained with the 22% crude protein feed. The levels of digestible arginine had a quadratic effect in feed conversion from 1 to 10 days old. The esophagus and crop weights were higher for broilers fed 20% crude protein based diet; however, there was a quadratic effect of the digestible arginine levels on the intestine length at the age of 10 days and on the esophagus + crop weight at 3 days of age. At 14 days of age, there was interaction among crude protein and digestible arginine levels for liver relative weight, which showed quadratic response to 20% of crude protein, and for intestine length, whose highest value was obtained with 22% of crude protein and 1.603% of digestible arginine. Nitrogen balance and retention were the highest for levels of 22% of crude protein. The level of 1.363% of digestible arginine meets nutritional requirements of pre-starter broilers