Temporal Progress of Yellow Sigatoka and Aerobiology of Mycosphaerella musicola Spores

An understanding of the progression of a disease is important in the adoption of control strategies as well as the evaluation of their efficacies. Temporal analysis is especially useful because it integrates the evolution of the interaction between the components of the pathosystem, as expressed by the accumulated data on the incidence and severity of disease and depicted by the disease progression curve. Within a given patho‐system, the dispersed airborne spores are important components in the progress of plant disease epidemics. Our aims were to evaluate the temporal dynamics of yellow Sigatoka in a banana plantation located in Coronel Pacheco, MG, Brazil, and to assess the aerobiology of Mycosphaerella musicola spores throughout the year. During the rainy season, we observed intense disease progression concomitant with high rates of leaf emission, which caused rapid reversal of the severity peaks after the maximum rates were reached. The yellow Sigatoka progress curve showed two peaks of extreme severity. The first, which occurred during the rainy season, was predominantly caused by a high concentration of conidia. The second, which occurred during the dry season, was predominantly caused by a high concentration of ascospores in the air. The ascospore concentrations were correlated with the severity of the disease 29 days later, indicating the average latency period of the disease in that region. The patterns of the severity curves for both peaks fit the monomolecular model, and the progression rates were higher during the rainy season than the dry season. The spore concentrations were the same at the two evaluated heights. In all evaluations, it was observed a higher concentration of ascospores than of conidia, with the greatest ascospore concentrations occurring during the early hours of the day and the greatest conidia concentrations occurring later, after the dew has dropped from the leaves.     

Exercise training improves aortic depressor nerve sensitivity in rats with ischemia-induced heart failure

Exercise training improves arterial baroreflex control in heart failure (HF) rabbits. However, the mechanisms involved in the amelioration of baroreflex control are unknown. We tested the hypothesis that exercise training would increase the afferent aortic depressor nerve activity (AODN) sensitivity in ischemic-induced HF rats. Twenty ischemic-induced HF rats were divided into trained (n = 11) and untrained (n = 9) groups. Nine normal control rats were also studied. Power spectral analysis of pulse interval, systolic blood pressure, renal sympathetic nerve activity (RSNA), and AODN were analyzed by means of autoregressive parametric spectral and cross-spectral algorithms. Spontaneous baroreflex sensitivity of heart rate (HR) and RSNA were analyzed during spontaneous variation of systolic blood pressure. Left ventricular end-diastolic pressure was higher in HF rats compared with that in the normal control group (P = 0.0001). Trained HF rats had a peak oxygen uptake higher than untrained rats and similar to normal controls (P = 0.01). Trained HF rats had lower low-frequency [1.8 +/- 0.2 vs. 14.6 +/- 3 normalized units (nu), P = 0.0003] and higher high-frequency (97.9 +/- 0.2 vs. 85.0 +/- 3 nu, P = 0.0005) components of pulse interval than untrained rats. Trained HF rats had higher spontaneous baroreceptor sensitivity of HR (1.19 +/- 0.2 vs. 0.51 +/- 0.1 ms/mmHg, P = 0.003) and RSNA [2.69 +/- 0.4 vs. 1.29 +/- 0.3 arbitrary units (au)/mmHg, P = 0.04] than untrained rats. In HF rats, exercise training increased spontaneous AODN sensitivity toward normal levels (trained HF rats, 1,791 +/- 215; untrained HF rats, 1,150 +/- 158; and normal control rats, 2,064 +/- 327 au/mmHg, P = 0.05). In conclusion, exercise training improves AODN sensitivity in HF rats.     

Intraspecific Variation in the Fruiting of an Amazonian Timber Tree: Implications for Management

Information concerning the fruit production of timber species is important for the assessment of the effects of logging practices and for the improvement of harvesting techniques. We assessed the effects of stem diameter, crown illumination, and liana load on Chrysophyllum lucentifolium subsp. pachycarpum fruiting over a 3-yr period in areas subjected to conventional and reduced impact logging 10–13 yr prior to the study and within a control area, in the eastern Brazilian Amazon. We further used this data set to estimate the proportion of fertile trees harvested following the adoption of 90 percent harvesting intensity and two different minimum diameter cutting limits (MDCL). Liana presence on > 50 percent of the crown was associated with a decrease in the odds of fruiting. Therefore, liana cutting aiming to increase fruiting output should target only trees in such a condition. We found no significant effects of logging treatments and crown illumination on the odds of fruiting. The percentage of reproductive trees, frequency, and intensity of fruiting increased markedly for trees > 40 cm dbh. The proportion of fertile trees harvested following the adoption of 50 cm dbh MDCL is relatively low (13–15%) and therefore, this practice is likely to have a low direct impact on C. lucentifolium fruiting at the population level. However, even for a population with relatively small fertile individuals and low proportion of trees ≥ 50 cm dbh, the MDCL should not be < 50 cm dbh, unless a lower harvest intensity is adopted.     

Metabolism of the mesoionic compound (MI‐D) by mouse liver microsome,detection of its metabolite In Vivo,and acute toxicity in mice

The mesoionic derivative 4‐phenyl‐5‐[4‐nitrocinnamoyl]‐1,3,4‐thiadiazolyl‐2‐phenylamine chloride (MI‐D) has antitumoral and anti‐inflammatory effects. In this study, we present aspects of its metabolism and toxicity in mice. MI‐D was metabolized in vitro by liver microsome, generating a main product with a much shorter retention time than MI‐D in high‐performance liquid chromatography (HPLC) analysis but with a spectrum similar to that of the original molecule. Mass spectrometry with electrospray ionization in positive mode analysis of the purified compound by HPLC indicated that the product of metabolism has four additional hydroxyl groups (m/z = 465) compared with MI‐D (m/z = 401). The HPLC analyses of plasma and urine samples from mice treated with MI‐D showed the presence of the metabolite product. The kinetic parameters K_m (19.5 ± 4.5 μM) and V_max [1.5 ± 0.4 units of fluorescence/(100 μg of microsomal protein/mL/s)] were estimated, confirming the metabolism of MI‐D and indicating that the reaction follows Michaelis‐Menten kinetics. Acute toxicity was established on the basis of an estimation of mean lethal dose (LD‐50; 181.2 mg/kg) and histopathological analysis of animals that survived the LD‐50 test. Abdominal adhesions, inflammatory foci, and formation of granulomas were observed. Altogether, the results contribute to the advancement of research in support of MI‐D as a future chemotherapeutic drug. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:394–405, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/jbt.20303     

Electromyographic evaluation of upper limb muscles involved in armwrestling sport simulation during dynamic and static conditions

ObjectiveTo evaluate the electromyographic activity of the Pectoralis Major (PM), Biceps Brachii (BB), Pronator Teres (PT) and Flexor Carpi Ulnaris (FCU) muscles involved in simulated armwrestling.MethodsTen trained volunteers were selected to perform the armwrestling movement, during dynamic tests with 40% and 80% of maximum voluntary load (MVL) and static tests in the initial, intermediary and final positions. Electromyographic and force data were normalized for analyses.ResultsIn dynamic tests with 40% MVL, electric activity of the PT muscle was greater than FCU (p < 0.01) and BB (p < 0.05) muscles, and with 80% MVL, PM and PT muscles were the most active. In static tests, electric activity increased from the initial to final positions for the PM muscle (p < 0.05), while it decreased for the BB and PT muscles (p < 0.001 and p < 0.05, respectively). No significant changes were observed for force and no correlation was found with the simultaneous electric activity.ConclusionsIt can be concluded that the PM and FCU muscles participate as agonists in the simulated armwrestling whereas the BB and PT muscles seem to perform secondary functions. Electric activity showed to be dependent on the load and on the position of the upper limb, but not on the force produced during the movement.     

Glass transition temperature of hard chairside reline materials after post‐polymerisation treatments

doi:10.1111/j.1741‐2358.2009.00312.x
Glass transition temperature of hard chairside reline materials after post‐polymerisation treatments Objective: This study evaluated the effect of post‐polymerisation treatments on the glass transition temperature (T_g) of five hard chairside reline materials (Duraliner II‐D, Kooliner‐K, New Truliner‐N, Ufi Gel hard‐U and Tokuso Rebase Fast‐T). Materials and methods: Specimens (10 × 10 × 1 mm) were made following the manufacturers’ instructions and divided into three groups (n = 5). Control group specimens were left untreated. Specimens from the microwave group were irradiated with pre‐determined power/time combinations, and specimens from the water‐bath group were immersed in hot water at 55°C for 10 min. Glass transition (°C) was performed by differential scanning calorimetry. Data were analysed using anova, followed by post hoc Tukey’s test (α = 0.05). Results: Both post‐polymerisation treatments promoted a significant (p < 0.05) increase in the T_g of reline material K. Materials K, D and N showed the lowest T_g (p < 0.05). No significant difference between T and U specimens was observed. Conclusion: Post‐polymerisation treatments improved the glass transition of material Kooliner, with the effect being more pronounced for microwave irradiation.     

First record of Sinoxylon conigerum Gerstäcker (Coleoptera: Bostrichidae) in Brazil

This is the first register of Sinoxylon conigerum attacking timber of teak (Tectona grandis L.f.), mango tree (Mangifera indica L.) and (Astronium fraxinifolium Schott) in the municipalities of Cuiabá and Várzea Grande, State of Mato Grosso, Brazil.     

Trypanosoma cruzi: TcRAB7 protein is localized at the Golgi apparatus in epimastigotes

In mammalian cells, the Rab7 protein is a key element of late endocytic membrane traffic. Several results suggest that it is involved in the transport from early to late endosome or from late endosome to lysosome. We have previously characterized a Rab7 gene homologue (TcRAB7) in Trypanosoma cruzi. Now, using an affinity-purified antibody specific to TcRAB7 protein we have determined that it is localized at the Golgi apparatus of the parasite. Our results indicate that the T. cruzi Rab7 homologue may function in a different route than its counterparts in mammalian cells.     

Innovative tools for detection of plant pathogenic viruses and bacteria

Detection of harmful viruses and bacteria in plant material, vectors or natural reservoirs is essential to ensure safe and sustainable agriculture. The techniques available have evolved significantly in the last few years to achieve rapid and reliable detection of pathogens, extraction of the target from the sample being important for optimising detection. For viruses, sample preparation has been simplified by imprinting or squashing plant material or insect vectors onto membranes. To improve the sensitivity of techniques for bacterial detection, a prior enrichment step in liquid or solid medium is advised. Serological and molecular techniques are currently the most appropriate when high numbers of samples need to be analysed. Specific monoclonal and/or recombinant antibodies are available for many plant pathogens and have contributed to the specificity of serological detection. Molecular detection can be optimised through the automatic purification of nucleic acids from pathogens by columns or robotics. New variants of PCR, such as simple or multiplex nested PCR in a single closed tube, co-operative-PCR and real-time monitoring of amplicons or quantitative PCR, allow high sensitivity in the detection of one or several pathogens in a single assay. The latest development in the analysis of nucleic acids is micro-array technology, but it requires generic DNA/RNA extraction and pre-amplification methods to increase detection sensitivity. The advances in research that will result from the sequencing of many plant pathogen genomes, especially now in the era of proteomics, represent a new source of information for the future development of sensitive and specific detection techniques for these microorganisms.