UNDERSTANDING THE RELATIONSHIP BETWEEN THE BROWN MARMORATED STINK BUG, HALYOMORPHA HALYS (STÅL), AND ITS SYMBIONT, PANTOEA CARBEKII, WITH IMPLICATIONS FOR STINK BUG MANAGEMENT

Symbiotic relationships between insects and beneficial microbes are very common in nature, especially within the Hemiptera. The brown marmorated stink bug, Halyomorpha halys Stål, harbors a symbiont, Pantoea carbekii, within the fourth region of the midgut in specialized crypts. In this dissertation, I explored this insect- microbe relationship. I determined that the brown marmorated stink bug is heavily reliant on its symbiont, and that experimental removal of the symbiont from the egg mass surface prior to nymphal acquisition led to lower survival, longer development, lower fecundity, and aberrant nymphal behavior. Additionally, I determined that even when the symbiont is acquired and housed in the midgut crypts, it is susceptible to stressors. Stink bugs reared at a higher temperature showed lower survival, longer development, and a cease in egg mass production, and when bugs were screened for their symbiont, fewer had successfully retained it while under heat stress. Finally, with the knowledge that the stink bug suffers decreases in fitness when its symbiont is missing or stressed, I wanted to determine if targeting the symbiont was a possible management technique for the stink bug. I tested the efficacy of a number of different insecticidal and antimicrobial products to determine whether prevention of symbiont acquisition from the egg mass was possible, and results indicated that transmission of the symbiont from the egg mass to the newly hatched nymph was negatively impacted when certain products were applied (namely surfactants or products containing surfactants). Additionally, direct effects on hatch rate and survival were reported for certain products, namely the insect growth regulator azadirachtin, which suggests that nymphs can pick up residues from the egg mass surface while probing for the symbiont. I conclude that P. carbekii plays a critically important role in the survival of its host, the brown marmorated stink bug, and its presence on the egg mass surface before nymphal hatch makes it targetable as a potential management technique.

ASSOCIATION OF BIRTH WEIGHT AND TIME OF BREASTFEEDING WITH CURRENT NUTRITIONAL STATUS OF CHILDREN

Objetivo: Analisar a relação entre o peso ao nascer (PN) e o tempo de aleitamento materno (AM) com o atual estado nutricional de crianças de dois a seis anos de idade. Métodos: Estudo observacional, quantitativo e do tipo transversal, realizado com crianças, independentemente do sexo, com idades entre dois a seis anos, matriculadas em sete escolas de educação infantil da rede municipal de um município do interior do Rio Grande do Sul (RS), no período de junho a agosto de 2014. Participaram 353 crianças, aferindo-se peso e altura, após os pais terem respondido a um questionário de Peso ao Nascer (PN) e tempo de aleitamento materno. Resultados: A média de aleitamento materno exclusivo foi de 3,47 ± 2,81 meses. A maioria das crianças (50,7%, n=179) encontrou-se em risco de sobrepeso ou sobrepeso para a idade, conforme o Índice de Massa Corporal (IMC). O PN apresentou correlação positiva com a altura atual (r=0,164, p=0,002) e com o peso atual (r=0,180, p=0,001). O PN foi significativamente maior entre os meninos (p=0,003), e o tempo de AM associado à alimentação complementar foi significativamente maior entre as meninas (p=0,024). Conclusão: Os resultados sugerem que o peso ao nascer influencia o ganho de peso nos seis primeiros anos de vida, com maior destaque para os meninos; e o tempo de amamentação associado à alimentação complementar foi maior entre as meninas.

Domestic Rhodnius ecuadoriensis (Hemiptera, Reduviidae) infestation in Northern Peru: a comparative trial of detection methods during a six-month follow-up

Two passive methods in the assessment of intradomiciliary infestation by Rhodnius ecuadoriensis were tested: (i) the Gomes Nuñez sensor box (GN), (ii) sheets of white typing paper and (iii) one active timed manual method. The study was carried out in the Alto Chicama River Valley, Province of Gran Chimú, Department of La Libertad. The study design consisted of an initial searching of triatomines inside of the domestic environment by the manual capture active procedure (man/hour) covering all the studied houses. Then, matched pairs of GN boxes and paper sheets were simultaneously installed in the bedrooms of 207 households distributed in 19 localities. A comparative prospective trial of these passive detection devices were monitored at 2, 4 and, finally 6 months follow-up. Parasitological Trypanosoma rangeli and/or T. cruzi infections were investigated in two houses with high level of infestation by R. ecuadoriensis.16.9% of the 207 households investigated by an initial active manual method were infested with R. ecuadoriensis. The proportion of infested houses fluctuated from 6.2 to 55.5% amongst the 19 localities investigated. T. rangeli natural infection was detected in R.ecuadoriensis specimens collected in two households. Parasite rates in the bugs ranged from 16.6 to 21.7% respectively. The most striking fact was an average rate of salivary gland infection ranging from 7.4 to 8.3%. At the end of the sixth month period, a cumulative incidence of 31.4% of positive GN boxes against 15.9% for paper sheets was recorded. All three methods combined detected domestic infestation in 129 (62.3%) of the 207 houses studied in the 19 localities. The range of houses infested varies from 6.7% to 92.9%. In areas with low bug density infestation rates, the methodology experienced in our studies, seems to be the best choice for investigations on domestic R. ecuadoriensis populations.

Análise proteômica de células não fagocíticas na fase inicial da infecção por trypanosoma cruzi

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Medicina, Programa de Pós-Graduação em Patologia Molecular, 2015.

A state machine for detecting c/c++ memory faults

Memory faults are major forms of software bugs that severely threaten system availability and security in c/c++ program. Many tools and techniques are available to check memory faults, but few provide systematic full-scale research and quantitative analysis. Furthermore, most of them produce high noise ratio of warning messages that require many human hours to review and eliminate false-positive alarms. And thus, they cannot locate the root causes of memory faults precisely. This paper provides an innovative state machine to check memory faults, which has three main contributions. Firstly, five concise formulas describing memory faults are given to make the mechanism of the state machine simple and flexible. Secondly, the state machine has the ability to locate the cause roots of the memory faults. Finally, a case study applying to an embedded software, which is written in 50 thousand lines of c codes, shows it can provide useful data to evaluate the reliability and quality of software.

Methods for Modeling and Analyzing Concurrent Software

Concurrent software executes multiple threads or processes to achieve high performance. However, concurrency results in a huge number of different system behaviors that are difficult to test and verify. The aim of this dissertation is to develop new methods and tools for modeling and analyzing concurrent software systems at design and code levels. This dissertation consists of several related results. First, a formal model of Mondex, an electronic purse system, is built using Petri nets from user requirements, which is formally verified using model checking. Second, Petri nets models are automatically mined from the event traces generated from scientific workflows. Third, partial order models are automatically extracted from some instrumented concurrent program execution, and potential atomicity violation bugs are automatically verified based on the partial order models using model checking. Our formal specification and verification of Mondex have contributed to the world wide effort in developing a verified software repository. Our method to mine Petri net models automatically from provenance offers a new approach to build scientific workflows. Our dynamic prediction tool, named McPatom, can predict several known bugs in real world systems including one that evades several other existing tools. McPatom is efficient and scalable as it takes advantage of the nature of atomicity violations and considers only a pair of threads and accesses to a single shared variable at one time. However, predictive tools need to consider the tradeoffs between precision and coverage. Based on McPatom, this dissertation presents two methods for improving the coverage and precision of atomicity violation predictions: 1) a post-prediction analysis method to increase coverage while ensuring precision; 2) a follow-up replaying method to further increase coverage. Both methods are implemented in a completely automatic tool.

Asociación entre factores socioeconómicos y hábitos de limpieza en gestantes de Usaquén y Kennedy de la ciudad de Bogotá

Introducción: Actualmente existe un reconocimiento creciente de que el hogar desempeña un papel importante en varias cuestiones de higiene y salud pública. El ambiente del hogar ha sido implicado como una fuente importante de propagación de enfermedades infecciosas, y la intervención de las medidas de higiene, implican una reducción de la incidencia, especialmente en los países menos desarrollados y en poblaciones vulnerables como las gestantes. Objetivo: Evaluar la asociación entre la práctica de hábitos higiénicos de las gestantes estrato 1 y 2 de las localidades de Usaquén y Kennedy en relación a sus factores socioeconómicos. Métodos: Estudio Analítico de Corte transversal. Se realizó en las gestantes de los estratos 1 y 2 de las localidades de Usaquén y Kennedy en la ciudad de Bogotá. Se recolectaron datos referentes a factores socioeconómicos y hábitos de higiene de 141 gestantes a través de la aplicación de una encuesta. Los datos obtenidos de las variables de interés fueron procesados a través de análisis multivariado y regresión logística paramétrica y no paramétrica, con el fin de establecer si existía asociación o no entre las mismas. Resultados: Existe asociación entre el número de Nacidos vivos y la presencia de plagas (p=0.034 y Coeficiente de correlación: -1.253). Así mismo se encontró asociación habitar en cuartos rentados y la limpieza de casa general (p=0.008 y Coeficiente de correlación: 0.480). Existe una asociación entre la variable edad y el lavado de frutas (p=0.041 y Coeficiente de correlación: 0.384). Conclusiones: Existe relación entre los hábitos higiénicos y los factores socioeconómicos de las gestantes estudiadas. Existe un mayor hábito de lavado de frutas antes de ser consumidas en gestantes de mayor edad. Adicional a esto se evidencia a mayor número de hijos hay menor presencia de plagas en el hogar y mayor limpieza del hogar. Solo en un pequeño porcentaje de los hogares se evidencio una óptima limpieza, por lo cual se deben plantear más políticas para mejorar la higiene de los mismos ya que los datos reportados permanecen subóptimos en la población seleccionada.

Tratamento de sementes para manejo do percevejo-barriga-verde na cultura de soja e milho em sucessão.

RESUMO: O objetivo deste trabalho foi avaliar o efeito do tratamento de sementes com inseticidas sobre o manejo de Dichelops melacanthus e a produtividade da soja e do milho, cultivados em sucessão. O estudo foi realizado em campo, nas safras 2012/2013 (I) e 2013/2014 (II). Avaliaram-se os inseticidas imidacloprido, tiametoxam, tiodicarbe, fipronil e abamectina. Determinaram-se: a densidade populacional do percevejo, a produtividade de soja e milho, e a intensidade da injúria em milho. A densidade do percevejo permaneceu abaixo de um inseto por metro quadrado, na maior parte do ciclo da soja. Os picos populacionais foram observados nas primeiras semanas, após a emergência do milho, e atingiram 2,2 (safra I) e 6,7 (safra II) percevejos por metro quadrado. Na cultura da soja, os inseticidas não reduziram a densidade populacional do percevejo. Na cultura do milho, o imidacloprido reduziu a densidade do percevejo em 23,2% (safra I) e 38,8% (safra II), e a injúria em 61,8% (safra I) e 26,4% (safra II). O tiametoxam reduziu a densidade dos insetos em 27,8% (safra II) e a injúria em 42,7% (safra I). O tratamento de sementes com inseticidas não proporciona aumento de produtividade à soja e ao milho, portanto, não se justifica sua utilização nas condições deste estudo. ABSTRACT: The objective of this work was to evaluate the effect of seed treatment with insecticides on the management of Dichelops melacanthus on the yield of soybean and corn, grown in succession. The study was carried out in a field, in the 2012/2013 (I) and 2013/2014 (II) crop seasons. The evaluated insecticides were: imidacloprid, thiamethoxam, thiodicarb, fipronil, and abamectin. The following were determined: stink bug population density, soybean and corn yield, and corn injury. Population density remained below one stink bug per square meter, in most of the soybean cycle. Population peaks were observed in the first weeks, after corn emergence, and they reached 2.2 (crop season I) and 6.7 (crop season II) stink bugs per square meter. In the soybean crop, the insecticides did not reduce the stink bug population density. In the corn crop, imidacloprid reduced the stink bug density in 23.2% (crop season I) and 38.8% (crop season II), and injury in 61.8% (crop season I) and 26.4% (crop season II). Thiamethoxam reduced the insect population density in 27.8% (crop season II) and injury in 42.7% (crop season I). Seed treatment with insecticides does not provide increase for soybean and corn yields, therefore, their use is not justified in this study's conditions.