Global stabilizing feedback law for a problem of biological control of mosquito-borne diseases

The control of the spread of dengue fever by introduction of the intracellular parasitic bacterium Wolbachia in populations of the vector Aedes aegypti, is presently one of the most promising tools for eliminating dengue, in the absence of an efficient vaccine. The success of this operation requires locally careful planning to determine the adequate number of mosquitoes carrying the Wolbachia parasite that need to be introduced into the natural population. The latter are expected to eventually replace the Wolbachia-free population and guarantee permanent protection against the transmission of dengue to human. In this paper, we propose and analyze a model describing the fundamental aspects of the competition between mosquitoes carrying Wolbachia and mosquitoes free of the parasite. We then introduce a simple feedback control law to synthesize an introduction protocol, and prove that the population is guaranteed to converge to a stable equilibrium where the totality of mosquitoes carry Wolbachia. The techniques are based on the theory of monotone control systems, as developed after Angeli and Sontag. Due to bistability, the considered input-output system has multivalued static characteristics, but the existing results are unable to prove almost-global stabilization, and ad hoc analysis has to be conducted.

Biological control of Bradysia matogrossensis (Diptera : Sciaridae) in mushroom cultivation with predatory mites

Larvae of Sciaridae flies (Diptera) cause considerable damage to the mushroom Agaricus blazei (Murrill) ss. Heinemann in Brazil. Brazilian growers have had considerable difficulties in controlling this pest. The objective of this work was to test the effect of the predatory Laelapidae mite Stratiolaelaps scimitus (Womersley) as a control agent of Bradysia matogrossensis (Lane) in cultures of A. blazei. The work corresponded to an evaluation of the efficiency of that predator when released in boxes containing each about 15 L of commercial mushroom compost naturally infested with the pest. The results showed a significant effect of that predator on the population of B. matogrossensis. The release of either 665 or 1330 S. scimitus per box significantly reduced the pest population to levels that, according to grower's experience, apparently could not cause considerable damage. The positive results obtained warrant the conduction of complementary studies to determine the lowest rates of the predator that could still produce acceptable levels of control.

The predatory mite Stratiolaelaps scimitus as a control agent of the fungus gnat Bradysia matogrossensis in commercial production of the mushroom Agaricus bisporus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of recombinant bovine somatotropin (bST) on follicular population and on in vitro buffalo embryo production

The objective of this study was to evaluate the effect of bovine somatotropin (bST) on ovarian follicular population in buffalo heifers and its influence on oocyte quality, recovery rates and in vitro embryo production. We tested the hypothesis that bST treatment in buffalo females submitted to an ovum pick-up (OPU) program Would improve the number of follicles recruited, oocyte quality and in vitro embryo production. A total of 10 heifers were assigned into two treatment groups: group bST (n = 5; receiving 500 mg of bST in regular intervals) and control group (n = 5; without additional treatment). Both groups were subjected to OPU sessions twice a week (every 3 or 4 days), for a total of 10 sessions per female, although due to procedural problems, only the first five OPU sessions produced embryos. The number of follicles and the diameters were recorded at all OPU sessions. The harvested oocytes were counted and classified according to their quality as either A, B, C, D or E, with A and B considered good quality. Cleavage and blastocyst production rates were evaluated 2 and 7 days after in vitro fertilization, respectively. The bST treatment increased the total number of antral follicles (> 3 mm in diameter; 12.2 compared with 8.7: p, < 0.05) and of small antral follicles (< 5 mm; 9.1 compared with 6.5; p < 0.05) per OPU session. The bST also tended to increase the number of oocytes recovered per session (5.2 compared with 4.1; p = 0.07), and enhanced the percentage of good quality oocytes (48.8% compared with 40.6%; p = 0.07), bST showed no effect on cleavage and blastocyst production rates (p > 0.05). The significant effects of performing repeated OPU sessions were decreasing the follicular population (p < 0.001) as well as the number of follicles aspirated (p < 0.001), and oocytes recovered (p < 0.02). In conclusion, bST treatment improves the follicular population, demonstrating its possible application in buffalo donors submitted to OPU programs. (c) 2008 Elsevier B.V. All rights reserved.

Effect of Spray Tips and Mix Deposition on Common Water Hyacinth Growing with Varied Population Arrangements of Salvinia and Water Lettuce

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Population dynamics of DENV-1 genotype V in Brazil is characterized by co-circulation and strain/lineage replacement

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Strain variability in the DNA immigration control region (ICR) of Xylella fastidiosa

The genome of the bacterium Xylella fastidiosa contains four ORFs (XF2721, XF2725, XF2739 and XF0295) related to the restriction modification type I system, ordinarily named R-M. This system belongs to the DNA immigration control region (ICR). Each CIRF is related to different operon structures, which are homologues among themselves and with subunit Hsd R from the endonuclease coding genes. In addition, these ORFs are highly homologous to genes in Pseudomonas aeruginosa, Methylococcus capsulatus str. Bath, Legionella pneumophila, Helicobacter pylori, Xanthomonas oryzae pv. Oryzae and Silicibacter pomeroyi, as well as to genes from X. fastidiosa strains that infect grapevine, almond and oleander plants. This study was carried out on R-M ORFs from forty-three X. fastidiosa strains isolated from citrus, coffee, grapevine, periwinkle, almond and plum trees, in order to assess the genetic diversity of these loci through PCR-RFLP. PCR-RFLP analysis of the four ORFs related to the R-M system from these strains enabled the detection of haplotypes for these loci. When the haplotypes were defined, wide genetic diversity and a large range of similar strains originating from different hosts were observed. This analysis also provided information indicating differences in population genetic structures, which led to detection of different levels of gene transfer among the groups of strains. (c) 2005 Elsevier SAS. All rights reserved.

Armadillo meat intake was not associated with leprosy in a case control study, Curitiba (Brazil)

Leprosy's progression and its maintained endemic status, despite the availability of effective treatments, are not fully understood and recent studies have highlighted the possibility of involved Mycobacterium leprae ambient reservoirs. Wild armadillos can carry leprosy and, because their meat is eaten by humans, development of the disease among armadillo meat consumers has been investigated. This study evaluated the frequency of armadillo meat intake among leprosy patients as well as age and gender matched controls with other skin diseases from a dermatological unit. Armadillo meat consumption among both groups was adjusted by demographic and socioeconomic covariates based on a conditional multiple logistic regression model. One hundred twenty-one cases and 242 controls were evaluated; they differed in socioeconomic variables such as family income, hometown population and access to treated water. The multivariate analysis did not show an association between the intake of armadillo meat and leprosy (odds ratio = 1.07; CI 95% 0.56-2.04), even when only cases with no known contacts were analyzed. We conclude that leprosy is not associated with the intake of armadillo meat in these patients.

Influence of glycemic control on fetal lung maturity in gestations affected by diabetes or mild hyperglycemia

Objective. To evaluate the influence of glycemic control on fetal lung maturity in pregnancies affected by diabetes or mild hyperglycemia. Design. Cross-sectional study. Setting. Level III maternity center. Population. A total of 187 pregnant women were submitted to routine amniocentesis for the assessment of fetal lung maturity up to 72 hours before delivery. Methods. Fetal lung maturity thresholds were: Clements-positive at a dilution of 0.5; OD(650) nm >= 0.15; and lamellar body count (LBC) >= 32,000/mu l. The relation of test results with adequate (<= 6.7 mmol/l) or poor (> 6.7 mmol/l) glycemic mean (GM) at term and at preterm was evaluated. Main outcome measure. Delay in fetal lung maturity when glycemic control was poor. Results. Glycemic control was adequate in 146 (78.1%) women. Clements maturity rates were higher at term (91.9%) than at preterm (64.7%) when GM <= 6.7 mmol/l (p < 0.001), but not when control was inadequate. LBC median was higher at term (99.0; 62.0-154.0) than at preterm (66.5; 40.5-108.25) (p = 0.009) when GM <= 6.7 mmol/l, while GM > 6.7 mmol/l did not lead to any difference between these rates at term or preterm. When glycemic control was adequate, OD(650) nm medians at term and at preterm were similar. However, when GM > 6.7 mmol/l, OD(650) nm median at term (0.29; 0.22-0.40) was higher than that observed at preterm (0.15; 0.12-0.18) (p < 0.001). Conclusions. Our results suggest that in term pregnancies routine amniocentesis for the assessment of fetal lung maturity should be abandoned. In preterm pregnancies, or when glycemic control is inadequate it is recommended.

Health-related behavior and quality of life among the elderly: a population-based study

OBJETIVO: Analisar a associação de comportamentos saudáveis com a qualidade de vida relacionada à saúde em idosos. MÉTODOS: Estudo transversal de base populacional que envolveu 1.958 idosos residentes em quatro áreas do estado de São Paulo, em 2001/2002. A qualidade de vida foi aferida com o uso do instrumento Medical Outcomes Study SF-36-Item Short Form Health Survey. As oito escalas e os dois componentes do instrumento constituíram as variáveis dependentes e as independentes foram atividade física, freqüência semanal de ingestão de bebida alcoólica e hábito de fumar. Modelos de regressão linear múltipla foram usados para controlar o efeito de sexo, idade, escolaridade, trabalho, área de residência e número de doenças crônicas. RESULTADOS: Atividade física foi positivamente associada com as oito escalas do SF-36. As maiores associações foram encontradas em aspectos físicos (β = 11,9), capacidade funcional (β = 11,3) e no componente físico. Idosos que ingeriam bebida alcoólica pelo menos uma vez por semana apresentaram melhor qualidade de vida do que os que não ingeriam. Comparados com os que nunca fumaram, os fumantes tiveram pior qualidade de vida no componente mental (β = -2,4). CONCLUSÕES: Os resultados apresentam que praticar atividade física, consumir bebida alcoólica moderadamente e não fumar são fatores positivamente associados a uma melhor qualidade de vida em idosos.

External control of the public water supply in 29 Brazilian cities

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Polymorphisms and Haplotypes in the Interleukin-4 Gene are Associated With Chronic Periodontitis in a Brazilian Population

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

Association of haplotypes in the IL8 gene with susceptibility to chronic periodontitis in a Brazilian population

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

Association of Haplotypes in the CXCR2 Gene with Periodontitis in a Brazilian Population

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

Low Apgar scores at 5 minutes in a low risk population: maternal and obstetrical factors and postnatal outcome

OBJETIVO: Avaliar a associação entre índice de Apgar menor que sete no 5º minuto, os fatores pré-natais e resultados pós-natais. MÉTODOS: Trata-se de estudo retrospectivo com 27.252 recém-nascidos em maternidade escola com população de baixo risco obstétrico, de janeiro de 2003 a dezembro de 2010. Prontuários de todos os casos com índice de Apgar < 7 no 5º minuto (n = 121; - 0,4%) e de 363 casos com Apgar > 7 no 5º minuto, escolhidos ao acaso, foram revisados. Os principais desfechos estudados foram: óbito neonatal, insuficiência respiratória neonatal, necessidade de intubação orotraqueal e de unidade terapia intensiva (UTI) neonatal e encefalopatia hipóxico-isquêmica. RESULTADOS: Após análise de regressão múltipla, desacelerações tardias (DIP II) (OR: 2,4; IC95%: 1,4-4,1) e período expulsivo prolongado (OR: 3,3; IC 95%: 1,3-8,3) se associaram com Apgar < 7 no 5º minuto; assim como com insuficiência respiratória ao nascimento (OR: 3,0; IC 95%: 1,3-6,9), intubação traqueal (OR: 2,5; IC 95%: 1,2-4,8), necessidade de UTI neonatal (OR: 9,5; IC 95%: 6,7-16,8) e encefalopatia hipóxico-isquêmica (OR: 14,1; IC 95%: 3,6-54,7). Nenhuma outra variável prénatal se associou com Apgar < 7 no 5º minuto (p < 0,05). CONCLUSÃO: DIP II e período expulsivo prolongado estão associados com Apgar < 7 no 5º minuto em população obstétrica de baixo risco; situação essa relacionada com maior risco de insuficiência respiratória no parto, necessidade de suporte ventilatório e encefalopatia hipóxico-isquêmica.