Molibdênio via semente e nitrogênio em cobertura no feijoeiro irrigado em solo de cerrado

O nitrogênio é o nutriente mais exigido pelo feijoeiro e seu metabolismo pode ser seriamente prejudicado pela deficiência de molibdênio. Conduziu-se este trabalho, com o objetivo de avaliar o efeito da aplicação de molibdênio via semente e nitrogênio em cobertura nas características agronômicas e produtividade do feijoeiro 'BRS Pontal' irrigado, cultivado em Neossolo Quartzarênico, no município de Cassilândia, MS. O delineamento experimental utilizado foi o de blocos casualizados, no esquema fatorial 4x2, com quatro repetições. Os tratamentos foram constituídos pela aplicação ou não de Mo (80 g ha-1) via semente e quatro doses de N (0, 30, 60 e 120 kg ha-1), em cobertura aos 16 dias, após a emergência, na forma de uréia. A aplicação de Mo via semente aumentou o índice relativo de clorofila, o número de vagens por planta, a massa e a produtividade de grãos no feijoeiro, principalmente com o uso de altas doses de N em cobertura. O índice relativo de clorofila, o número de vagens por planta, a massa e a produtividade de grãos do feijoeiro foi aumentada linearmente pela aplicação de até 120 kg ha-1 de N em cobertura. O fornecimento de Mo via tratamento de semente aumentou a eficiência de utilização do N pelo feijoeiro.

Biological and DNA evidence of two dissimilar populations of the Rhipicephalus sanguineus tick group (Acari : Ixodidae) in South America

In this work, the biology, mitochondrial DNA and fertility of hybrids from two strains of Rhipicephalus sanguineus, from Brazil and Argentina, were compared. Engorged larvae, nymphs and adults from Argentina weighed more and the engorgement period of adult females was significantly longer than those of their Brazilian counterparts, whereas adult female tick yield rate was higher for the Brazilian strain. High intraspecific divergence of mitochondrial DNA was detected between R. sanguineus from Brazil and Argentina. on the other hand, a strong genetic relationship was detected between European and Argentinean R. sanguineus populations while the Brazilian population appeared to be related to the African Rhipicephalus turanicus. Adult hybrid females laid eggs, which were mostly unviable, whereas a mean of more than 1400 larvae hatched per egg mass from pure Brazilian and Argentinean strains. These results showed that differences between these strains are greater than previously assumed and that the biosysternatic status of R. sanguineus ticks from South America should be re-evaluated. Wide variations, such as these might account for the reported worldwide differences in biology and vector capacity of this species. (c) 2005 Elsevier B.V. All rights reserved.

Effects of the magnesium and chloride ions and shikimate on the structure of shikimate kinase from Mycobacterium tuberculosis

Bacteria, fungi and plants can convert carbohydrate and phosphoenolpyruvate into chorismate, which is the precursor of various aromatic compounds. The seven enzymes of the shikimate pathway are responsible for this conversion. Shikimate kinase (SK) is the fifth enzyme in this pathway and converts shikimate to shikimate-3-phosphate. In this work, the conformational changes that occur on binding of shikimate, magnesium and chloride ions to SK from Mycobacterium tuberculosis (MtSK) are described. It was observed that both ions and shikimate influence the conformation of residues of the active site of MtSK. Magnesium influences the conformation of the shikimate hydroxyl groups and the position of the side chains of some of the residues of the active site. Chloride seems to influence the affinity of ADP and its position in the active site and the opening length of the LID domain. Shikimate binding causes a closing of the LID domain and also seems to influence the crystallographic packing of SK. The results shown here could be useful for understanding the catalytic mechanism of SK and the role of ions in the activity of this protein.

Doses de inoculante e nitrogênio na semeadura da soja em área de primeiro cultivo

The inoculation of soybean crop with Bradyrhizobium bacteria is a widespread practice, due to excellent results achieved in productivity, however, some doubt still arise in relation the need of application of mineral nitrogen at sowing. In that mean, this work aimed to evaluate the response of the doses at inoculant and mineral nitrogen in the sowing of crop soybean in area of first cultivation. The experiments were carried in the experimental field of the University of the Estate of Mato Grosso, Campus of Alta Floresta - MT, Brazil, in the growing seasons of 2006/2007 and 2007/2008. The experimental design was randomized blocks, in a factorial escheme 2 x 4, with four replications. The factors consisted in the inoculation of seeds with Bradyrhizobium japonicum *(3 e 6 mL kg(-1) of seeds), and nitrogen fertilizer at sowing *(0, 10, 20 e 40 kg ha(-1)). The following variables were evaluated: plant height, insertion height of first pod, number of pod per plant, number of grain per pod, mass of 100 grain and grain productivity. In the two growing seasons there was no significant difference for doses of inoculants applied in first year of cultivation with soybean. To nitrogen application at sowing of soybean crop there was quadratic effect to plant height and of insertion height of first pod and growing linear to number of pod per plant in the second year of cultivation, however, without significant increase the productivity.

Irradiance stress responses of gas exchange and antioxidant enzyme contents in pariparoba [Pothomorphe umbellata (L.) Miq.] plants

We evaluated the growth and development of the medicinal species Pothomorphe umbellata ( L.) Miq. under different shade levels ( full sun and 30, 50, and 70 % shade, marked as I(100), I(70), I(50), and I(30), respectively) and their effects on gas exchange and activities of antioxidant enzymes. Photosynthetically active radiation varied from 1 254 mu mol m(-2) s(-1) at I(100) to 285 mu mol m(-2) s(-1) at I(30). Stomatal conductance, net photosynthetic rate, and relative chlorophyll (Chl) content were maximal in I(70) plants. Plants grown under I(100) produced leaves with lower Chl content and signs of chlorosis and necrosis. These symptoms indicated Chl degradation induced by the generation of reactive oxygen species. Stress related antioxidant enzyme activities ( Mn-SOD, Fe-SOD, and Cu/Zn-SOD) were highest in I(100) plants, whereas catalase activity was the lowest. Hence P. umbellata is a shade species ( sciophyte), a feature that should be considered in reforestation programs or in field plantings for production of medicinal constituents.

Thyroid State and Tolerance of Mammalian Myocardium to Hypoxia

Thyroid hormone is known to affect myocardial glycogen stores and thereby possibly limit anaerobic performance of mammalian cardiac muscle. Thyroid hormone administration (3,5,T-triiodo-L-thyroxine, 300 mu g/kg/day, sc) for 10 days decreased left ventricle (LV) glycogen concentration relative to euthyroid animals (2.78 +/- 0.46 vs. 4.28 +/- 0.29 mg/g of LV (mean +/- SEM)) while increasing the percent of V(1) myosin isozyi-ne, contractile activity and cardiac mass. In contrast, thyroidectomy increased myocardial glycogen stores (8.50 +/- 0.56 mg/g of LV) and shifted the myosin isozyme toward V(3), prolonged contractile activity and decreased LV mass. Thyroxine administration for 3, 7 and 10 days to thyroidectomized animals progressively decreased contractile duration and increased LV mass. Thyroxine administration for 3 or 7 days to thyroidectomized rats did not reduce glycogen stores (7.75 +/- 1.02 and 9.62 +/- 1.16 mg/g of LV, respectively), whereas myocardial glycogen declined to 3.30 +/- 0.58 mg/g of LV after 10 days of treatment. During hypoxia, cardiac muscle from thyroidectomized rats maintained greater active force and developed less contracture relative to euthyroid and, to a greater extent, than hyperthyroid rats. Removal of glucose from the bath decreased anaerobic performance and impaired recovery; however, myocardium from thyroidectomized rats remained more tolerant to hypoxia than the euthyroid group. Overall, the intrinsic LV glycogen content was positively correlated to anaerobic performance. These data demonstrate that the thyroid state profoundly affects myocardial growth, contractility and anaerobic performance of rat myocardium. Although energy demand may affect function during hypoxia, anaerobic substrate reserve (cardiac glycogen concentration) appears to be the primary factor determining tolerance to hypoxic stress. J. Exp. Zool. 311A:399-407, 2009. (C) 2009 Wiley-Liss, Inc.

Effects of olive oil and its minor constituents on serum lipids, oxidative stress, and energy metabolism in cardiac muscle

Recent lines of evidence suggest that the beneficial effects of olive oil are not only related to its high content of oleic acid, but also to the antioxidant potential of its polyphenols. The aim of this work was determine the effects of olive oil and its components, oleic acid and the polyphenol dihydroxyphenylethanol (DPE), on serum lipids, oxidative stress, and energy metabolism on cardiac tissue. Twenty four male Wistar rats, 200 g, were divided into the following 4 groups (n = 6): control (C), OO group that received extra-virgin olive oil (7.5 mL/kg), OA group was treated with oleic acid (3.45 mL/kg), and the DPE group that received the polyphenol DPE (7.5 mg/kg). These components were administered by gavage over 30 days, twice a week. All animals were provided with food and water ad libitum The results show that olive oil was more effective than its isolated components in improving lipid profile, elevating high-density lipoprotein, and diminishing low-density lipoprotein cholesterol concentrations. Olive oil induced decreased antioxidant Mn-superoxide dismutase activity and diminished protein carbonyl concentration, indicating that olive oil may exert direct antioxidant effect on myocardium. DPE, considered as potential antioxidant, induced elevated aerobic metabolism, triacylglycerols, and lipid hydroperoxides concentrations in cardiac muscle, indicating that long-term intake of this polyphenol may induce its undesirable pro-oxidant activity on myocardium. © 2006 NRC Canada.

Cardiovascular responses produced by central injection of hydrogen peroxide in conscious rats

Reactive oxygen species (ROS) have been shown to modulate neuronal synaptic transmission and may play a role on the autonomic control of the cardiovascular system. In this study we investigated the effects produced by hydrogen peroxide (H 2O 2) injected alone or combined with the anti-oxidant agent N-acetil-l-cysteine (NAC) or catalase into the fourth brain ventricle (4th V) on mean arterial pressure and heart rate of conscious rats. Moreover the involvement of the autonomic nervous system on the cardiovascular responses to H 2O 2 into the 4th V was also investigated. Male Holtzman rats (280-320 g) with a stainless steel cannula implanted into the 4th V and polyethylene cannulas inserted into the femoral artery and vein were used. Injections of H 2O 2 (0.5, 1.0 and 1.5 μmol/0.2 μL, n = 6) into the 4th V produced transient (for 10 min) dose-dependent pressor responses. The 1.0 and 1.5 μmol doses of H 2O 2 also produced a long lasting bradycardia (at least 24 h with the high dose of H 2O 2). Prior injection of N-acetyl-l-cysteine (250 nmol/1 μL/rat) into the 4th V blockade the pressor response and attenuated the bradycardic response to H 2O 2 (1 μmol/0.5 μL/rat, n = 7) into the 4th V. Intravenous (i.v.) atropine methyl bromide (1.0 mg/kg, n = 11) abolished the bradycardia but did not affect the pressor response to H 2O 2. Prazosin hydrochloride (1.0 mg/kg, n = 6) i.v. abolished the pressor response but did not affect the bradycardia. The increase in the catalase activity (500 UEA/1 μL/rat injected into the 4th V) also abolished both, pressor and bradycardic responses to H 2O 2. The results suggest that increased ROS availability into 4th V simultaneously activate sympathetic and parasympathetic outflow inducing pressor and bradycardic responses. © 2006 Elsevier Inc. All rights reserved.

Clinical and nutritional profile of individuals with Chagas disease

Chagas disease (CD), caused by the protozoan Trypanossoma cruzi, affects approximately 18 million individuals in the Americas, 5 million of which five in Brazil. Most chronic sufferers have either the indeterminate form of the disease, without organic compromise, or the cardiac or digestive forms. Despite the importance of this disease, there is no information on the effect of nutrition on CD evolution. We evaluated the clinical-nutritional profile of individuals with CD treated at the Tropical Diseases Nutrition Out-Patient Clinic of the Botucatu School of Medicine, UNESP.A retrospective cohort study was performed between 2002 and 2006, on 66 patients with serum and parasitological diagnosis of CD. Epidemiological, clinical, nutritional, and biochemical data were collected, including gender, age, skin color, smoking, alcoholism, physical activity, weight, stature, body mass index, abdominal circumference, glycemia, and lipid profile. Fifty-three percent were mate and 47% female; 96% were white skinned. Mean age was 49.6±6.36 years. The predominant form was indeterminate in 71 %; smoking and drinking were recorded in 23% and 17%, respectively. Sedentariness predominated in 83%, and 55% presented increased abdominal circumference. Most, 94%, were overweight or obese. The biochemical exam revealed hyperglycemia in 12% and dyslipidemia in 74%. These findings suggest that the Chagas population presents co-morbidities and risk factors for developing chronic non-transmissible diseases, including cardiovascular diseases, making CD evolution even worse. © 2007 by The Brazilian Journal of Infectious Diseases and Contexto Publishing. All rights reserved.

Quality control of Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) from different Brazilian bio-factories

The goal of this study was to evaluate the quality of Cotesia flavipes from different bio-factories as biological control agents. We evaluated biological characteristics of the parasitoids throughout their lifespan, and measured the body length and width, abdomen width, thorax width and width and length of the right forewing of female and male parasitoids. Our results showed that the number of males and pupal viability were similar among the bio-factories; the number of emerged females was greater in bio-factories I and II; the egg-pupa period and the pupal period were shorter in bio-factory IV; and a greater longevity was found in bio-factories II and III. Sex ratio (at approximately 60% females) was satisfactory (in terms of suitability for release) across all bio-factories. For morphometric measurements, the body, abdomen and wing widths were similar in males; however, thorax width was greater in the males from bio-factory I; bio-factory III produced females with the highest body length; bio-factory I produced females with the greatest abdomen width; bio-factories III and IV produced females with the greatest wing length. Among the bio-factories studied, bio-factory IV produced the best quality C. flavipes, with respect to the greatest number of parasitoids per pupal mass (a mean of 57% more parasitoids) in a satisfactory sex ratio, and with the shortest developmental time, which facilitates faster rearing in the laboratory. Studies such as this, which assess the quality of a mass-produced C. flavipes, are crucial for the continued use of this parasitoid in controlling Diatraea saccharalis in the field. © 2013 Copyright Taylor and Francis Group, LLC.

Parâmetros genéticos entre caracteres quantitativos no girassol como critério de seleção para produtividade de aquênios

Two experiments were conducted in southern Brazil in no-tillage system, in order to estimate genetic parameters and the direct and indirect effects of components for achene yield as a selection criterion in sunflower. We analyzed eight sunflower hybrids at two locations, in a randomized complete block design with four replicates, determined through quantitative descriptors: insertion height of the head, and head stem diameter, weight of 1000 achenes, number of achenes per head, mass by achene head and yield achene. Estimates of genetic parameters were based on combined analysis, decomposing interactions in genetic and environmental components. Considering the coefficient of genetic variation, indirect effects of components and heritability, there are higher possibilities for responses to selection in sunflower achenes by descriptors mass and mass of achenes per head, with its indirect association interrelated pathways for the increase in the achenes of yield.

Comparison of the effect of rose bengal- and eosin Y-mediated photodynamic inactivation on planktonic cells and biofilms of Candida albicans

Candida albicans is an opportunistic yeast that can cause oral candidosis through the formation of a biofilm, an important virulence factor that compromises the action of antifungal agents. The objective of this study was to compare the effect of rose bengal (RB)- and eosin Y (EY)-mediated photodynamic inactivation (PDI) using a green light-emitting diode (LED; 532 ± 10 nm) on planktonic cells and biofilms of C. albicans (ATCC 18804). Planktonic cultures were treated with photosensitizers at concentrations ranging from 0.78 to 400 μM, and biofilms were treated with 200 μM of photosensitizers. The number of colony-forming unit per milliliter (CFU/mL) was compared by analysis of variance and Tukey's test (P ≤ 0.05). After treatment, one biofilm specimen of the control and PDI groups were examined by scanning electron microscopy. The photosensitizers (6.25, 25, 50, 200, and 400 μM of EY, and 6.25 μM of RB or higher) significantly reduced the number of CFU/mL in the PDI groups when compared to the control group. With respect to biofilm formation, RB- and EY-mediated PDI promoted reductions of 0.22 log10 and 0.45 log10, respectively. Scanning electron microscopy showed that the two photosensitizers reduced fungal structures. In conclusion, EY- and RB-mediated PDI using LED irradiation significantly reduced C. albicans planktonic cells and biofilms. © 2013 Springer-Verlag London.

Espaçamento entre fileiras e população de plantas para cultivares de mamona de porte baixo na safra de verão e safrinha

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo comparativo do estresse oxidativo entre tilápias (Oreochromis niloticus) e cascudos (Pterygoplichthys anisitsi) expostos a óleo diesel e a biodiesel

Pós-graduação em Biologia Animal - IBILCE

Efeito de produtos a base de Bacillus thuringiensis Berliner em aspectos biológicos de Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)