Resposta do capim-tanzânia à aplicação de manganês

The objective was to evaluate the influence of the manganese nutritional status, growth and dry matter production of Tanzania grass. For this, we used plants of Panicum maximum Jacq. cv. Tanzania grown in pots filled with Oxisol (Mn = 0.6 mg dm(-3)). The experimental design was completely randomized, with five doses of manganese (0, 15, 30, 60 and 120 mg dm(-3)) and four replications. The plant shoot were harvested twice, the first 42 days after sowing and the second, 30 days after the first cut. In the two sections were evaluated the number of tillers and leaves, steam diameter, plant height, shoot dry matter and in shoot-Mn concentration and root dry matter after the second cut. The application of manganese in the soil increased the levels of this nutrient in the soil and their uptake by grass, which was more than four times fold higher in the second cut compared to the first cut. The use of high rates of Mn did not affect the growth of Panicum maximum, and decreased dry matter production only for the sum of two cuts, indicating high tolerance of forage of Mn toxicity. The toxicity of Mn in forage was associated with leaf content in the first and second cut of 1,238 and 1,418 mg kg(-1), respectively.

Efeitos da aplicação de manganês no crescimento, na nutrição e na produção de matéria seca de plantas de Brachiaria brizantha (cv. MG4) em condições de casa de vegetação

A adubação com micronutrientes, como o manganês em gramíneas forrageiras tropicais, contribui para o atendimento das exigências nutricionais tanto das plantas quanto dos animais. Objetivou-se, neste trabalho, estudar os efeitos da aplicação de manganês no crescimento, na nutrição e na produção de matéria seca de plantas de Brachiaria brizantha, em condições de casa de vegetação. Para isto, realizou-se um experimento em casa de vegetação da FCAV/UNESP, Campus de Jaboticabal, com Brachiaria brizantha (cv. MG4), em vasos com 3,5 dm³ preenchidos com amostras de um Latossolo Vermelho distrófico (Mn = 0,6 mg dm-3). O delineamento experimental foi inteiramente casualizado, com cinco tratamentos, que corresponderam às doses de manganês (0, 15, 30, 60 e 120 mg dm-3), e quatro repetições. Avaliaram-se, nos dois cortes da forrageira (primeiro corte, 35 dias após o transplantio e, segundo, 30 dias após o primeiro), as variáveis de crescimento, produção de massa de forragem, teor e acúmulo de Mn na parte aérea. As doses de manganês aplicadas aumentaram a concentração deste micronutriente no solo e nas plantas e a produção de massa de forragem no primeiro corte. A Brachiaria brizantha cv. MG4 apresenta alta tolerância ao manganês, atingindo elevados teores de Mn na parte aérea, mesmo sem provocar sintomas visuais de toxicidade.

Tolerância do campim Marandu a doses de manganês

The cultivation of pastures in Brazil is mostly done with the species Brachiaria spp. However, there is little research on nutrition with manganese for this forage. It was aimed to asses the effects of manganese in the development and nutrition of marandu grass. The experimental design used was fully randomized, consisting of five rates of manganese ( 0, 15, 30, 60 e 120 mg dm(-3)) and four repetitions. The experimental unit was formed in a vase filled with a Red Latosol dystrophic. There were two cuts, the first after 38 days of transplanting seedling and the second 30 days after the first cut. Was evaluated the content of manganese leaf, the dry mass of the shoot, the number of tillers and the leaf area. The levels of manganese increased its accumulation in the plant, second cut compared to the first cut. The marandu grass showed high tolerance to manganese toxicity, reaching a high leaf content in the shoot without affecting plant growth.

Fungos anamorfos do solo da região dos lagos no Município de Santa Gertrudes, SP, Brasil

O solo do pólo cerâmico no município de Santa Gertrudes, SP, tem sido poluído há décadas por diversos elementos químicos, principalmente chumbo e zinco. Foram realizadas quatro coletas de amostras de solo, duas durante a época chuvosa e duas na seca, em cinco locais, de novembro de 2002 a junho de 2003, determinando-se temperatura, pH, teores de chumbo e zinco e a umidade do solo. Os fungos foram isolados pelo método de Warcup, modificado pelo preparo de suspensões aquosas de solo (1:10) e aplicação de 1 cm³ das suspensões sobre malte agar (2%), adicionado de Zn(NO3)2 e Pb(NO3)2 em concentrações crescentes: 0, 100, 200, 500 e 1.000 mg dm-3. Após cinco dias de incubação a 25 ºC, as colônias foram purificadas e identificadas. Foram obtidos 70 táxons de fungos anamorfos, com 70% de similaridade entre as micotas obtidas nos meios com os dois metais. Foram isolados 43 táxons nos meios de cultura com Pb(NO3)2, com predominância deles nas concentrações mais elevadas (500 a 1.000 mg dm-3). Foram obtidos 63 táxons nos meios com Zn(NO3)2, principalmente nas concentrações moderada e elevada (200 e 500 mg dm-3). Prevaleceram espécies de Trichoderma, de Penicillium e diversos fungos que são encontrados associados a substratos vegetais em decomposição. A tendência de se obter número elevado de táxons em meios de cultura com concentrações moderadas a elevadas de Zn e Pb pode ser justificada pela existência de bem adaptada e competitiva micota do solo, caracterizada por elevada capacidade de tolerância aos metais e eficiente habilidade sapróbia competitiva.

Desenvolvimento e nutrição do capim-Tanzânia em função da aplicação de zinco

It was aimed to assess the effects of zinc in the development and nutrition of Tanzania grass. The experimental design used was fully randomized, consisting of six doses of zinc (0, 15, 30, 60, 120 and 240 mg dm'3) and four repetitions. The experimental unit was formed in a vase filled with a Red Latosol dystrophic (Zn = 0.4 mg dm). There were two cuts, the first after 53 days of transplanting seedlings and the second 35 days after the first cut. Was evaluated the concentration of zinc in the soil, the content of zinc leaf, the number of tillers, number of leaves, plant height, the dry mass of the shoot, root system and the whole plant. The doses of zinc influenced the concentration of zinc in soil and plant, and production of dry mass of Tanzania grass, especially the first cut. The Tanzania grass shows high tolerance to the toxicity of zinc, and toxic critical level of 273 mg kg-1.

Desempenho inicial da laranjeira Valência sobre 43 porta-enxertos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

EFFECT OF FOOD SHORTAGE ON GROWTH, ENERGETIC RESERVES MOBILIZATION, AND WATER QUALITY IN JUVENILES OF THE REDCLAW CRAYFISH, CHERAX QUADRICARINATUS, REARED IN GROUPS

The aim of this study is to analyze the impact of food shortage on growth performance, by means of energetic reserves (proteins, glycogen and lipids) mobilization and hepatopancreas cells analysis in C. quadricarinatus juveniles maintained in groups, as well as the effect on culture water quality. Two experiments were performed, each of them with two feeding regimes during 45 days. The Control feeding regime, in which crayfish were fed daily (once a day) throughout the experimental period (DF), and the Cyclic feeding regime, in which juveniles were fed for 2 or 4 days (once a day) followed by 2 or 4 days of food deprivation (2F/2D and 4F/4D, respectively) in repeated cycles. Cyclic feeding influenced growth, biochemical composition from hepatopancreas and muscle, and water quality. Juveniles cyclically fed were unable to maintain a normal growth trajectory during 45 days. Apparent feed conversion ratio, apparent protein efficiency ratio, hepatosomatic index and relative pleon mass were similar in cyclic and daily fed animals and no structural damage was found in the hepatopancreas of juveniles subjected to cyclic feeding. The novelty of this study was the significant accumulation of proteins in pleonal muscle in both cyclic feeding regimes (approx. 18%) suggesting that the storage of this constitutive material during food shortage may be an adaptation for a compensatory growth when food becomes abundant again. The cyclic feeding regimes had a positive effect on water quality decreasing inorganic nitrogen concentration. This was due to the reduction in the amount of animal excretes and feces in the group that received approx. 50% less feed. Additionally, water pH was higher in cyclic feeding tanks, as a result of lower organic matter decomposition and consequent release of CO2. Accordingly, total ammonia in the water was significantly lower for the cyclic feeding regimes compared to their respective controls. This study suggests that the protocol of cyclic feeding could be applied at least 45 days in 1 g juveniles maintained in group conditions, without affecting the energetic reserves and hepatopancreas structure, emphasizing the high tolerance of this species to food restriction.

Thermal and spectroscopic studies of the antioxidant food additive propyl gallate

Literature mentions propyl gallate (PG) as a non-toxic synthetic antioxidant that can be used as a food additive due to its high tolerance to heat. It is important to understand the thermal properties and to identify the decomposition products of this substance, since it has been reported to be thermally stable at temperatures as high as 300 °C. Simultaneous thermogravimetry-differential thermal analysis (TG-DTA), differential scanning calorimetry-photovisual (DSC-photovisual), coupled thermogravimetry-infrared spectroscopy (TG-FTIR) analyses and spectroscopic techniques were used to study the food additive PG. The TG-DTA curves, which were performed with the aid of DSC-photovisual, provided information concerning the thermal stability and decomposition profiles of the compound. From the TG-FTIR coupled techniques, it was possible to identify n-propanol as a possible volatile compound released during the thermal decomposition of the antioxidant. A complete spectroscopic characterization in the ultraviolet, visible, near and middle infrared regions was performed in order to understand the spectroscopic properties of PG.

Response of the rat spinal cord to X-ray microbeams

BACKGROUND AND PURPOSE: To quantify the late dose-related responses of the rat cervical spinal cord to X-ray irradiations by an array of microbeams or by a single millimeter beam. MATERIALS AND METHODS: Necks of anesthetized rats were irradiated transversely by an 11mm wide array of 52 parallel, 35μm wide, vertical X-ray microbeams, separated by 210μm intervals between centers. Comparison was made with rats irradiated with a 1.35mm wide single beam of similar X-rays. Rats were killed when paresis developed, or up to 383days post irradiation (dpi). RESULTS: Microbeam peak/valley doses of ≈357/12.7Gy to 715/25.4Gy to an 11mm long segment of the spinal cord, or single beam doses of ≈146-454Gy to a 1.35mm long segment caused foreleg paresis and histopathologically verified spinal cord damage; rats exposed to peak/valley doses up to 253/9Gy were paresis-free at 383dpi. CONCLUSIONS: Whereas microbeam radiation therapy [MRT] for malignant gliomas implanted in rat brains can be safe, palliative or curative, the high tolerance of normal rat spinal cords to similar microbeam exposures justifies testing MRT for autochthonous malignancies in the central nervous system of larger animals with a view to subsequent clinical applications.

Testing an alternative search algorithm for compound identification with the 'Wiley Registry of Tandem Mass Spectral Data. MSforID'

A tandem mass spectral database system consists of a library of reference spectra and a search program. State-of-the-art search programs show a high tolerance for variability in compound-specific fragmentation patterns produced by collision-induced decomposition and enable sensitive and specific 'identity search'. In this communication, performance characteristics of two search algorithms combined with the 'Wiley Registry of Tandem Mass Spectral Data, MSforID' (Wiley Registry MSMS, John Wiley and Sons, Hoboken, NJ, USA) were evaluated. The search algorithms tested were the MSMS search algorithm implemented in the NIST MS Search program 2.0g (NIST, Gaithersburg, MD, USA) and the MSforID algorithm (John Wiley and Sons, Hoboken, NJ, USA). Sample spectra were acquired on different instruments and, thus, covered a broad range of possible experimental conditions or were generated in silico. For each algorithm, more than 30,000 matches were performed. Statistical evaluation of the library search results revealed that principally both search algorithms can be combined with the Wiley Registry MSMS to create a reliable identification tool. It appears, however, that a higher degree of spectral similarity is necessary to obtain a correct match with the NIST MS Search program. This characteristic of the NIST MS Search program has a positive effect on specificity as it helps to avoid false positive matches (type I errors), but reduces sensitivity. Thus, particularly with sample spectra acquired on instruments differing in their Setup from tandem-in-space type fragmentation, a comparably higher number of false negative matches (type II errors) were observed by searching the Wiley Registry MSMS.

Effects of microbeam radiation therapy on normal and tumoral blood vessels

Microbeam radiation therapy (MRT) is a new form of preclinical radiotherapy using quasi-parallel arrays of synchrotron X-ray microbeams. While the deposition of several hundred Grays in the microbeam paths, the normal brain tissues presents a high tolerance which is accompanied by the permanence of apparently normal vessels. Conversely, the efficiency of MRT on tumor growth control is thought to be related to a preferential damaging of tumor blood vessels. The high resistance of the healthy vascular network was demonstrated in different animal models by in vivo biphoton microscopy, magnetic resonance imaging, and histological studies. While a transient increase in permeability was shown, the structure of the vessels remained intact. The use of a chick chorioallantoic membrane at different stages of development showed that the damages induced by microbeams depend on vessel maturation. In vivo and ultrastructural observations showed negligible effects of microbeams on the mature vasculature at late stages of development; nevertheless a complete destruction of the immature capillary plexus was found in the microbeam paths. The use of MRT in rodent models revealed a preferential effect on tumor vessels. Although no major modification was observed in the vasculature of normal brain tissue, tumors showed a denudation of capillaries accompanied by transient increased permeability followed by reduced tumor perfusion and finally, a decrease in number of tumor vessels. Thus, MRT is a very promising treatment strategy with pronounced tumor control effects most likely based on the anti-vascular effects of MRT.

Frequencies and risk factors for bisphosphonate-related osteonecrosis of the jaw in cancer patients: A matched case-control study

Bisphosphonates represent a unique class of drugs that effectively treat and prevent a variety of bone-related disorders including metastatic bone disease and osteoporosis. High tolerance and high efficacy rates quickly ranked bisphosphonates as the standard of care for bone-related diseases. However, in the early 2000s, case reports began to surface that linked bisphosphonates with osteonecrosis of the jaw (ONJ). Since that time, studies conducted have corroborated the linkage. However, as with most disease states, many factors can contribute to the onset of disease. The aim of this study was to determine which comorbid factors presented an increased risk for developing ONJ in cancer patients.^ Using a case-control study design, investigators used a combination of ICD-9 codes and chart review to identify confirmed cases of ONJ at The University of Texas M. D. Anderson Cancer Center (MDACC). Each case was then matched to five controls based on age, gender, race/ethnicity, and primary cancer diagnosis. Data querying and chart review provided information on variables of interest. These variables included bisphosphonate exposure, glucocorticoids exposure, smoking history, obesity, and diabetes. Statistical analysis was conducted using PASW (Predictive Analytics Software) Statistics, Version 18 (SPSS Inc., Chicago, Illinois).^ One hundred twelve (112) cases were identified as confirmed cases of ONJ. Variables were run using univariate logistic regression to determine significance (p < .05); significant variables were included in the final conditional logistic regression model. Concurrent use of bisphosphonates and glucocorticoids (OR, 18.60; CI, 8.85 to 39.12; p < .001), current smokers (OR, 2.52; CI, 1.21 to 5.25; p = .014), and presence of diabetes (OR, 1.84; CI, 1.06 to 3.20; p = .030) were found to increase the risk for developing ONJ. Obesity was not associated significantly with ONJ development.^ In this study, cancer patients that received bisphosphonates as part of their therapeutic regimen were found to have an 18-fold increase in their risk of developing ONJ. Other factors included smoking and diabetes. More studies examining the concurrent use of glucocorticoids and bisphosphonates may be able to strengthen any correlations.^

Seawater carbonate chemistry and larval growth response of the Portuguese oyster (Crassostrea angulata) in a laboratory experiment

Rising anthropogenic carbon dioxide (CO2) dissolving into coastal waters is decreasing the pH and carbonate ion concentration, thereby lowering the saturation state of calcium carbonate (CaCO3) minerals through a process named ocean acidification (OA). The unprecedented threats posed by such low pH on calcifying larvae of several edible oyster species have not yet been fully explored. Effects of low pH (7.9, 7.6, 7.4) on the early growth phase of Portuguese oyster (Crassostrea angulata) veliger larvae was examined at ambient salinity (34 ppt) and the low-salinity (27 ppt) treatment. Additionally, the combined effect of pH (8.1, 7.6), salinity (24 and 34 ppt) and temperature (24 °C and 30 °C) was examined using factorial experimental design. Surprisingly, the early growth phase from hatching to 5-day-old veliger stage showed high tolerance to pH 7.9 and pH 7.6 at both 34 ppt and 27 ppt. Larval shell area was significantly smaller at pH 7.4 only in low-salinity. In the 3-factor experiment, shell area was affected by salinity and the interaction between salinity and temperature but not by other combinations. Larvae produced the largest shell at the elevated temperature in low-salinity, regardless of pH. Thus the growth of the Portuguese oyster larvae appears to be robust to near-future pH level (> 7.6) when combined with projected elevated temperature and low-salinity in the coastal aquaculture zones of South China Sea.

Larval and post-larval stages of pacific oyster (Crassostrea gigas) are resistant to elevated CO2

Rising anthropogenic carbon dioxide (CO2) dissolving into coastal waters is decreasing the pH and carbonate ion concentration, thereby lowering the saturation state of calcium carbonate (CaCO3) minerals through a process named ocean acidification (OA). The unprecedented threats posed by such low pH on calcifying larvae of several edible oyster species have not yet been fully explored. Effects of low pH (7.9, 7.6, 7.4) on the early growth phase of Portuguese oyster (Crassostrea angulata) veliger larvae was examined at ambient salinity (34 ppt) and the low-salinity (27 ppt) treatment. Additionally, the combined effect of pH (8.1, 7.6), salinity (24 and 34 ppt) and temperature (24 °C and 30 °C) was examined using factorial experimental design. Surprisingly, the early growth phase from hatching to 5-day-old veliger stage showed high tolerance to pH 7.9 and pH 7.6 at both 34 ppt and 27 ppt. Larval shell area was significantly smaller at pH 7.4 only in low-salinity. In the 3-factor experiment, shell area was affected by salinity and the interaction between salinity and temperature but not by other combinations. Larvae produced the largest shell at the elevated temperature in low-salinity, regardless of pH. Thus the growth of the Portuguese oyster larvae appears to be robust to near-future pH level (> 7.6) when combined with projected elevated temperature and low-salinity in the coastal aquaculture zones of South China Sea.

Habitat traits and food availability determine the response of marine invertebrates to ocean acidification

Energy availability and local adaptation are major components in mediating the effects of ocean acidification (OA) on marine species. In a long-term study, we investigated the effects of food availability and elevated pCO2 (ca 400, 1000 and 3000 µatm) on growth of newly settled Amphibalanus (Balanus) improvisus to reproduction, and on their offspring. We also compared two different populations, which were presumed to differ in their sensitivity to pCO2 due to differing habitat conditions: Kiel Fjord, Germany (Western Baltic Sea) with naturally strong pCO2 fluctuations, and the Tjärnö Archipelago, Sweden (Skagerrak) with far lower fluctuations. Over 20 weeks, survival, growth, reproduction and shell strength of Kiel barnacles were all unaffected by elevated pCO2, regardless of food availability. Moulting frequency and shell corrosion increased with increasing pCO2 in adults. Larval development and juvenile growth of the F1 generation were tolerant to increased pCO2, irrespective of parental treatment. In contrast, elevated pCO2 had a strong negative impact on survival of Tjärnö barnacles. Specimens from this population were able to withstand moderate levels of elevated pCO2 over 5 weeks when food was plentiful but showed reduced growth under food limitation. Severe levels of elevated pCO2 negatively impacted growth of Tjärnö barnacles in both food treatments. We demonstrate a conspicuously higher tolerance to elevated pCO2 in Kiel barnacles than in Tjärnö barnacles. This tolerance was carried-over from adults to their offspring. Our findings indicate that populations from fluctuating pCO2 environments are more tolerant to elevated pCO2 than populations from more stable pCO2 habitats. We furthermore provide evidence that energy availability can mediate the ability of barnacles to withstand moderate CO2 stress. Considering the high tolerance of Kiel specimens and the possibility to adapt over many generations, near future OA alone does not seem to present a major threat for A. improvisus