Effect of food on immature development, consumption rate, and relative growth rate of Toxorhynchites splendens (Diptera: Culicidae), a predator of container breeding mosquitoes

Food utilization by the larvae of Toxorhynchites splendens (Wiedemann) was studied in the laboratory by offering larvae of Aedes aegypti Linnaeus, Anopheles stephensi (Liston), and Culex quinquefasciatus (Say). Quantitative analyses of data indicated that immature development was significantly faster with increase in food availability. The regression analysis showed that the degrees of the relationship between immature duration (Id) and food availability were higher when offered early instars of prey (first and second instars) than late instars. Consumption rate (Cr) of the predator increased with increase in food availability and this relationship was highly significant when larvae of An. stephensi were offered as food. Consumption rate to food level decreased with increase in the age class of the prey. There was a significant negative correlation between Id and Cr. This aspect helps to increase population turnover of T. splendens in a shorter period when the prey is abundant. Conversely, the predator compensated the loss in daily food intake at low food level by extending Id thereby attains the minimum threshold pupal weight for adult emergence. There was an increase in the relative growth rate (RGR) of the predator when An. stephensi was offered as prey and this was related to the high protein content of the prey per body weight. There was a positive correlation between Cr and RGR. This adaptive life characteristic strategy of this predator is useful for mass-rearing for large scale field release programmes in the control of container breeding mosquitoes is discussed.

The effects of temperature change on the infection rate of Biomphalaria glabrata with Schistosoma mansoni

The aim of this study was to investigate the influence of temperature on the development of Schistosoma mansoni infections in Biomphalaria glabrata. The snails were infected at 15, 20, and 30ºC, and the cercarial release was analyzed after 30 and 60 days post-infection. Our results showed that a decrease in the temperature has a substantial influence on the development of S. mansoni infection in B. glabrata, with significant differences (p < 0.05) between 15 and 30ºC. These data could provide a better understanding of the epidemiological aspects of schistosomiasis.

Seroepidemiology of hepatitis B virus infection and high rate of response to hepatitis B virus Butang®vaccine in adolescents from low income families in Central Brazil

In order to evaluate the seroepidemiology and response to Butang® vaccine in adolescents from low income families in Central Brazil, blood samples of 664 adolescents were tested for hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and hepatitis B surface antibody (anti-HBs) markers, and multiple logistical regression analysis was carried out to determine variables associated with hepatitis B virus (HBV) infection markers. further, three 20 µg butang® vaccine doses were offered to all susceptible individuals (n = 304). Among those who accepted them (n = 182), the seroresponse was evaluated in 170 individuals by quantitative anti-HBs. an overall hbv prevalence of 5.9% was found: four adolescents were HBsAg positive, 24 were anti-HBc, anti-HBs-reactive, and 11 were anti-HBc only. The analyse of risk factors showed that age 16-19 years, place of birth outside Goiás, school B and body piercing were statistically associated with HBV infection markers (p < 0.05). All 170 adolescents responded to butang®, and a geometric mean titer (gmt) of 4344 mui/ml was obtained. these results reinforce the importance of hepatitis b vaccine in adolescents despite of the hbv regional endemicity, and suggest that three doses of 20 µg of the butang® should guarantee protective anti-hbs levels to individuals at a critical time for hepatitis b acquiring such as latter adolescence and adulthood.

Le taux de détresse respiratoire du nouveau-né augmente, celui des césariennes aussi: et si ce n'était pas un hasard? [Respiratory distress of the neonate and the rate of caesarean section have increased over the last 30 years. Is there a link?]

Ces trente dernières années, on note en Suisse une augmentation significative de l'incidence du syndrome de détresse respiratoire (SDR) chez le nouveau-né (NN), touchant particulièrement les enfants avec un poids de naissance >2500 g. En même temps, le taux des césariennes (CS) s'est aussi accru. Une explication pour une éventuelle corrélation entre les deux évolutions est une augmentation en particulier des CS électives qui ont tendance à être planifiées à un terme précoce pour éviter la mise en travail spontanée. Suite à cela, le foetus est privé de différents mécanismes qui favorisent l'adaptation pulmonaire périnatale. Les bénéfices réels de la CS sur la morbidité tant foetale que maternelle ne doivent pas faire oublier que la CS est un facteur de risque pour le SDR du NN. Ce risque peut être diminué efficacement en planifiant une CS élective après 39 semaines révolues. In Switzerland, the rate of respiratory distress in neonates needing hospitalization has doubled over the last thirty years, concerning in particular babies weighing more than 2500 g. In the same time, the rate of Caesarean section (CS) has also multiplied. We suppose that a link between the two evolutions might be the increase of elective CS. They tend to be planned early at term to avoid the onset of spontaneous labour As a consequence, the foetus is deprived of different mechanisms helping pulmonary transition around birth. The potential benefits of CS regarding morbidity of foetus and mother should not overshadow that CS is a significant risk factor for respiratory problems of the neonate. This risk could be dramatically decreased by planning elective CS only after completed 39 weeks of gestation

Co-infections associated with human immunodeficiency virus type 1 in pregnant women from southern Brazil: high rate of intraepithelial cervical lesions

Human immunodeficiency virus type 1 (HIV-positive) pregnant women require specific prophylactic and therapeutic approaches. The efficacy of established approaches is further challenged by co-infection with other sexually transmitted diseases (STDs). The objective of this study was to determine the prevalence of co-infections in pregnant women infected with different HIV-1 subtypes and to relate these findings, together with additional demographic and clinical parameters, to maternal and infant outcomes. Blood samples from pregnant women were collected and tested for syphilis, hepatitis B virus (HBV) and hepatitis C virus (HCV). Human papillomavirus (HPV) diagnosis was evaluated by the presence of alterations in the cervical epithelium detected through a cytopathological exam. Medical charts provided patient data for the mothers and children. Statistical analyses were conducted with STATA 9.0. We found a prevalence of 10.8% for HCV, 2.3% for chronic HBV, 3.1% for syphilis and 40.8% for HPV. Of those co-infected with HPV, 52.9% presented high-grade intraepithelial lesions or in situ carcinoma. Prematurity, birth weight, Apgar 1' and 5' and Capurro scores were similar between co-infected and non-co-infected women. The presence of other STDs did not impact maternal and concept outcomes. More than half of the patients presenting cervical cytology abnormalities suggestive of HPV had high-grade squamous intraepithelial lesions or cervical cancer, evidencing an alarming rate of these lesions.

Progression rate of self-propelled feeding tubes in critically ill patients.

OBJECTIVE: Gaining postpyloric access in ventilated, sedated ICU patients usually requires time-consuming procedures such as endoscopy. Recently, a feeding tube has been introduced that migrates spontaneously into the jejunum in surgical patients. The study aimed at assessing the rate of migration of this tube in critically ill patients. DESIGN: Prospective descriptive trial. SETTING: Surgical ICU in a tertiary University Hospital. PATIENTS: One hundred and five consecutive surgical ICU patients requiring enteral feeding were enrolled, resulting in 128 feeding-tube placement attempts. METHODS: A self-propelled tube was used and followed up for 3 days: progression was assessed by daily contrast-injected X-ray. Severity of illness was assessed with SAPS II and organ failure assessed with SOFA score. RESULTS: The patients were aged 55+/-19 years (mean+/-SD) with SAPS II score of 45+/-18. Of the 128 tube placement attempts, 12 could not be placed in the stomach; eight were accidentally pulled out while in gastric position due to the necessity to avoid fixation during the progression phase. Among organ failures, respiratory failure predominated, followed by cardiovascular. By day 3, the postpyloric progression rate was 63/128 tubes (49%). There was no association between migration and age, or SAPS II score, but the progression rate was significantly poorer in patients with hemodynamic failure. Use of norepinephrine and morphine were negatively associated with tube progression (P<0.001), while abdominal surgery was not. In ten patients, jejunal tubes were placed by endoscopy. CONCLUSION: Self-propelled feeding tubes progressed from the stomach to the postpyloric position in 49% of patients, reducing the number of endoscopic placements: these tubes may facilitate enteral nutrient delivery in the ICU.

Predictors of return to work after a knee injury in patients hospitalized in vocational rehabilitation

Introduction.- Knee injuries are frequent in a young and active population. Most of the patients resume their professional activity but few studies were interested in factors that predict a return to work. The aim of this study is to identify these predictors from a large panel of bio-psychosocial variables. We postulated that the return to work 3 months and 2 years after discharge is mostly predicted by psychosocial variables.Patients and methods.- Prospective study, patients hospitalized for a knee injury. Variables measured: the abbreviated injury score (AIS) for the gravity of the injuries, analog visual scale for the intensity of pain, INTERMED for the bio-psychosocial complexity, SF-36 for the quality of life, HADs for the anxiety/depression symptoms and IKDC score for the knee function. Univariate logistic regressions, adjusted for age and gender, were performed in order to predict return to work.Results.- One hundred and twenty-six patients hospitalized during 8 months after the accident were included into this prospective study. A total of 73 (58%) and 75 (59%) questionnaires were available after 3 months and 2 years, respectively. The SF-36 pain was the sole predictor of return to work at 3 months (odds Ratio 1.06 [1.02-1.10], P = 0.01; for a one point increase) and 2 years (odds Ratio 1.06 [1.02-1.10], P = 0.01). At three months, other factors are SF-36 (physic sub-scale), IKDC score, the presence of a work contract and the presence of litigation. The bio-psychosocial complexity, the presence of depressive symptoms predicts the return to work at two years.Discussion.- Our working hypothesis was partially confirmed: some psychosocial factors (i.e. depressive symptoms, work contract, litigation, INTERMED) predict the return to work but the physical health and the knee function, perceived by the patient, are also correlated. Pain is the sole factor isolated at both times (i.e. 3 months and 2 years) and, consequently, appears a key element in the prediction of the return to work. Some factors are accessible to the rehabilitation program but only if an interdisciplinary approach is performed.

Rate of gene sequence evolution and species diversification in flowering plants: a re-evaluation

Barraclough and co-workers (in a paper published in 1996) observed that there was a significant positive correlation between the rate of evolution of the rbcL chloroplast gene within families of flowering plants and the number of species in those families. We tested three additional data sets of our own (based on both plastid and nuclear genes) and used methods designed specifically for the comparison of sister families (based on random speciation and extinction). We show that, over all sister groups, the correlation between the rate of gene evolution and an increased diversity is not always present. Despite tending towards a positive association, the observation of individual probabilities presents a U-shaped distribution of association (i.e. it can be either significantly positive or negative). We discuss the influence of both phylogenetic sampling and applied taxonomies on the results.

Large fluctuations in the disassembly rate of microtubules revealed by atomic force microscopy.

Atomic force microscopy (AFM) in situ has been used to observe the cold disassembly dynamics of microtubules at a previously unrealised spatial resolution. Microtubules either electrostatically or covalently bound to aminosilane surfaces disassembled at room temperature under buffer solutions with no free tubulin present. This process was followed by taking sequential tapping-mode AFM images and measuring the change in the microtubule end position as a function of time, with an spatial accuracy down to +/-20nm and a temporal accuracy of +/-1s. As well as giving average disassembly rates on the order of 1-10 tubulin monomers per second, large fluctuations in the disassembly rate were revealed, indicating that the process is far from smooth and linear under these experimental conditions. The surface bound rates measured here are comparable to the rates for GMPCPP-tubulin microtubules free in solution, suggesting that inhibition of tubulin curvature through steric hindrance controls the average, relatively low disassembly rate. The large fluctuations in this rate are thought to be due to multiple pathways in the kinetics of disassembly with differing rate constants and/or stalling due to defects in the microtubule lattice. Microtubules that were covalently bound to the surface left behind the protofilaments covalently cross-linked to the aminosilane via glutaraldehyde during the disassembly process. Further work is needed to quantitatively assess the effects of surface binding on protofibril disassembly rates, reveal any differences in disassembly rates between the plus and minus ends and to enable assembly as well as disassembly to be imaged in the microscope fluid cell in real-time.

Trophic specialization influences the rate of environmental niche evolution in damselfishes (Pomacentridae).

The rate of environmental niche evolution describes the capability of species to explore the available environmental space and is known to vary among species owing to lineage-specific factors. Trophic specialization is a main force driving species evolution and is responsible for classical examples of adaptive radiations in fishes. We investigate the effect of trophic specialization on the rate of environmental niche evolution in the damselfish, Pomacentridae, which is an important family of tropical reef fishes. First, phylogenetic niche conservatism is not detected in the family using a standard test of phylogenetic signal, and we demonstrate that the environmental niches of damselfishes that differ in trophic specialization are not equivalent while they still overlap at their mean values. Second, we estimate the relative rates of niche evolution on the phylogenetic tree and show the heterogeneity among rates of environmental niche evolution of the three trophic groups. We suggest that behavioural characteristics related to trophic specialization can constrain the evolution of the environmental niche and lead to conserved niches in specialist lineages. Our results show the extent of influence of several traits on the evolution of the environmental niche and shed new light on the evolution of damselfishes, which is a key lineage in current efforts to conserve biodiversity in coral reefs.

Age over 40 years increases the failure rate of non-operative management of blunt splenic injuries

Objective: Non-operative management (NOM) of blunt splenic injuries (BSI) is nowadays considered the standard treatment. The study aimed to determine the criteria applied for NOM and to identify risk factors for its failure. Methods: Review of all adult patients with BSI treated at the University Hospital Bern, Switzerland, between 2000 and 2008. Results: There were 206 patients (146 men, 70·9%) with a mean age of 38·2 ± 19·1 years and an Injury Severity Score of 30·9 ± 11·6. The American Association for the Surgery of Trauma classification of the splenic injury was: grade I, n=43 (20·9%); grade II, n=52 (25·2%); grade III, n=60 (29·1%); grade IV, n=42 (20·4%) and grade V, n=9 (4·4%). 47 patients (22·8%) required immediate surgery. Five or more units of red cell transfusions (P<0·001), Glasgow Coma Scale<11 (P=0·009) and age ≥55 years (P=0·038) were associated with primary operative management (OM). 159 patients (77·2%) qualified for NOM, which was successful in 89·9% (143/159). The overall splenic salvage rate was 69·4% (143/206). Multivariate analysis found age ≥40 years to be the only factor independently related to the failure of NOM (P=0·001). Conclusion: Advanced age is associated with an increased failure rate ofNOM in patients with BSI.

Type of prey influences biology and consumption rate of Orius insidiosus (Say) (Hemiptera, Anthocoridae)

Generalist predators are capable of consuming different types of prey, and as each prey may have distinct nutritional values, each may have a distinct impact on the biology of the predator. Therefore, the aim of this study was to determine how the consumption of different prey influences certain biological characteristics and the predatory capacity of Orius insidiosus (Say). The investigation was performed in climatic chamber at 25 ±1 ºC, RH 70 ± 10% and fotophase 12. Eggs of Anagasta kuehniella (Zeller), adults of Caliothrips phaseoli (Hood) and nymphs of Aphis gossypii Glover were used as prey and were provided daily ad libitum for all the mobile stages of the predator. The results showed that biological parameters of O. insidiosus are affected differently depending on the type of prey ingested. The development time of the nymphal stage was 13.1, 11.23 and 10.25 days for O. insidiosus feeding on eggs of A. kuehniella, nymphs of A. gossypii and adults of C. phaseoli, respectively. Longevity was five times larger for adults fed on eggs of A. kuehniella (56.25 days) compared to that of adults that preyed on nymphs of A. gossypii (11.44 days), and four times larger when the prey were adults of C. phaseoli (13.58 days). The consumption of eggs of A. kuehniella by predator females resulted in a shorter pre-oviposition period (3.2 days) and a longer oviposition period (44.4 days) when compared to the consumption of other types of prey. In addition, fecundity was increased with the consumption of eggs of A. kuehniella (195.25 eggs laid / female) when compared to feeding on the other prey, C. phaseoli (70.00 eggs laid / female) or A. gossypii (22.50 eggs laid / female). However, the consumption of aphids was larger (148.28 nymphs/ nymphal stage) than that of thrips (74.10 thrips / nymphal stage) or eggs of A. kuehniella (37.03 eggs /nymphal stage) for all of the nymphal stages of the predator. The results indicate that the eggs of A. kuehniella are the type of prey best suited for rearing this predator insect under laboratory conditions. Also fecundity was better with this prey even though the predator consumed during its nymphal stage a lesser quantity of eggs compared to the other prey.

Rate of convergence of a particle method to the solution of the Mc Kean-Vlasov's equation

This paper studies the rate of convergence of an appropriatediscretization scheme of the solution of the Mc Kean-Vlasovequation introduced by Bossy and Talay. More specifically,we consider approximations of the distribution and of thedensity of the solution of the stochastic differentialequation associated to the Mc Kean - Vlasov equation. Thescheme adopted here is a mixed one: Euler/weakly interactingparticle system. If $n$ is the number of weakly interactingparticles and $h$ is the uniform step in the timediscretization, we prove that the rate of convergence of thedistribution functions of the approximating sequence in the $L^1(\Omega\times \Bbb R)$ norm and in the sup norm is of theorder of $\frac 1{\sqrt n} + h $, while for the densities is ofthe order $ h +\frac 1 {\sqrt {nh}}$. This result is obtainedby carefully employing techniques of Malliavin Calculus.

Rate of development of forensically-important Dipterain southern Brazil

Dipteran larvae were collected from rabbit (Oryctolagus cunniculus L.) carcasses during the four seasons in 2005 in the southernmost state of Rio Grande do Sul, Brazil. The larvae were fed ground beef at ambient temperatures following collection from carcasses. The development of each species under these conditions was estimated. The most abundant species in the carcasses were Lucilia eximia (Wiedemann) and Chrysomya albiceps (Wiedemann) (Calliphoridae), and they were found in all seasons. The data were fitted to a linear model that describes the relationship between temperature and linear developmental rating. These two species are primary forensic indicators in southern Brazil. Other species such as Hemilucilia semidiaphana (Rondani) (Calliphoridae), Synthesiomyia nudiseta (Wulp), Muscina stabulans (Fallen) (Muscidae), and Fannia pusio (Wiedemann) (Fanniidae) were forensically less important because they only occurred in high frequency in certain seasons and during the first days of carcass decomposition.