Differential response to the South American rice water weevil (Coleoptera: Curculionidae) damage of rice cultivars with contrasting levels of resistance: implications for field management.

BACKGROUND: Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae) is a major pest of flooded rice paddies throughout South America, and species with very similar life histories are present in many rice-producing regions of the world (collectively rice water weevils, RWWs). The damage caused by RWW larvae on rice cultivars with contrasting levels of resistance ('BRS Pampa CL'= 'Pamp': susceptible, 'BRS Atalanta' = 'Atal': resistant-antibiosis) was evaluated in two consecutive years in the field under seven infestation levels: 0, 2, 4, 6, 8, 10 and 20 adult couples per cage with plants. RESULTS: Higher densities of adults increased the number of leaf-feeding scars and larvae on roots, respectively, at the rate ≤2.14 and 2.75 in Pamp and 2.23 and 2.48 in Atal, with the total number of larvae generated being lower in Atal. Grain yield was negatively impacted with increasing larval density on the roots, mainly by decreasing root volume and the number of grains per panicle. Root injury intensity and yield loss showed a nonlinear relationship. It was found that significant yield losses occurred with 8.37 larvae per plant in Pamp and 9.80 larvae per plant in Atal CONCLUSION: The results provided the first evidence of a tolerance limit for RWW larval damage that, even though similar between cultivars of contrasting resistance, corresponds to twice the current conventional level for larval control in Brazil. We also discuss here the potential of applying tolerance limits to manage the RWW adult population in rice fields. © 2022 Society of Chemical Industry.

Malaria in Angola: recent progress, challenges and future opportunities using parasite demography studies.

Over the past two decades, a considerable expansion of malaria interventions has occurred at the national level in Angola, together with cross-border initiatives and regional efforts in southern Africa. Currently, Angola aims to consolidate malaria control and to accelerate the transition from control to pre-elimination, along with other country members of the Elimination 8 initiative. However, the tremendous heterogeneity in malaria prevalence among Angolan provinces, as well as internal population movements and migration across borders, represent major challenges for the Angolan National Malaria Control Programme. This review aims to contribute to the understanding of factors underlying the complex malaria situation in Angola and to encourage future research studies on transmission dynamics and population structure of Plasmodium falciparum, important areas to complement host epidemiological information and to help reenergize the goal of malaria elimination in the country.

Iatrogenic fistula between the aorta and the right ventricular outflow tract after Melody valve implantation: Case report and literature review.

We present the first case of an iatrogenic aorta to right ventricular outflow tract fistula after Melody valve implantation. A 11-year-old girl, born with tetralogy of Fallot with absent pulmonary valve, underwent surgical repair at three years old with a 15-mm homograft. At five years old, calcification and stenosis of the homograft prompted successful balloon angioplasty and five years later she underwent Melody valve implantation. During follow-up, she began to suffer fatigue on moderate exertion. Echocardiography, cardiac catheterization and computed tomography were performed and showed a significant fistula between the right coronary ostium and the right ventricular outflow tract proximal to the implanted valve. The patient underwent surgical repair and in long-term follow-up there is no evidence of the fistula. Iatrogenic fistula between the ascending aorta and the right ventricular outflow tract after percutaneous pulmonary valve implantation is an uncommon complication, and may grow over time. A high level of suspicion is required for this rare complication and a final aortography may be necessary for the diagnosis.

Long-term results of percutaneous balloon valvuloplasty in neonatal critical pulmonary valve stenosis: a 20-year, single-centre experience.

Introduction Percutaneous balloon valvuloplasty is the primary treatment for critical pulmonary valve stenosis in neonates. Thus far, a few studies have reported long-term results of this technique in neonatal critical pulmonary valve stenosis. METHODS: We carried out a retrospective study of all consecutive newborns with critical pulmonary valve stenosis subjected to percutaneous balloon valvuloplasty at a single centre, between 1994 and 2014, to assess its immediate and long-term safety and efficacy. RESULTS: A total of 24 neonates presented with critical pulmonary valve stenosis. The mean diameter of the pulmonary annulus was 7 mm (±1.19); 33.3% had a dysplastic pulmonary valve, and 92% were started on prostaglandin E1 treatment. Percutaneous balloon valvuloplasty was performed at a mean age of 4.0±4.3 days using, on average, a balloon-to-pulmonary annulus ratio of 1.18 mm (with a range from 0.9 to 1.43). Immediate success was achieved in 22/24 patients (92%) with a reduction in the pulmonary transvalvular peak gradient (p<0.05) and in the right ventricle/systemic pressure ratio (p<0.05). There was one death (4%) 6 days after the procedure, and 29.2% of them had transient rhythm complications. For a mean follow-up time of 8.4 years, the re-intervention rate was 42.9%. In total, 14 re-interventions were performed in nine neonates, including surgery in six. Freedom from re-intervention was 50% at 8 years and 43% at 10 and 15 years. CONCLUSION: This series, to the best of our knowledge, has had the longest follow-up of neonates with critical pulmonary valve stenosis. Percutaneous balloon valvuloplasty is a safe and effective treatment, and in our study 75% of the patients were exclusively treated using this technique.

[Immunohistochemistry in a case of EBV encephalitis]. / Inmunohistoquímica en un caso de encefalitis por virus de Epstein Barr.

EBV can produce a broad range of CNS disorders such as demyelinative diseases, acute encephalitis, cerebellar ataxia, myelitis, or meningitis. The role of EBV itself in acute encephalitis is not completely clear. Presently we described a 4 years old boy with EBV encephalitis that deceased after respiratory distress and cardio-respiratory arrest. At autopsy the most important changes in the brain were focal sub cortical peri-vascular mononuclear inflammation of the cerebral vessels. EBV antigens were demonstrated by immunohistochemistry in some cells of the vascular walls and in some glial cells of the brain. As expected this indicates a predominantly cellular response in the brain. The presence of EBV antigens by immunohistochemistry associated to a scarce inflammatory infiltrate supports the hypothesis that EBV itself plays a major role in the pathogenesis of EBV encephalitis.

[Genetic diversity of Tibraca limbativentris Stål (Hemiptera: Pentatomidae) of Santa Catarina and Rio Grande do Sul, Brazil, using RAPD]. / Diversidade genética de Tibraca limbativentris Stål (Hemiptera: Pentatomidae) de Santa Catarina e do Rio Grande do Sul, usando marcadores RAPD.

The work was carried out to test DNA extraction protocols and to characterize populations of Tibraca limbativentris Stål, an important rice insect-pest. Insects were collected in Joinville, Rio do Oeste and Turvo, in Santa Catarina State, and Agudo, Uruguaiana, Pelotas and Palmares do Sul, in Rio Grande do Sul State, and six literature-referenced protocols, besides a new one, were tested. DNA from ten individuals of each population was extracted using the best protocol and RAPD reactions were carried out with ten initiators. The new protocol showed the best results and was used in the PCR reactions, that generated 151 polymorphic bands, allowing to access genetic differences among all the populations; no individuals from one population were clustered with individuals from another. The largest intrapopulacional similarity was found in Uruguaiana (22%), and the smallest in Palmares do Sul (50%), which was also the most divergent population in relation to the others. The Gst was 0.5215, and the Nm was 0.4588; these values reflect the low similarity between the populations. The smallest genic flow was obtained when Palmares do Sul and Pelotas were included in the comparisons, in accordance with the largest divergence of these two populations in relation to the others. There was no significant relation between geographic distance and genetic similarity, which can reflect unknown model of dispersion of T. limbativentris. New studies exploring the species dispersion strategies may help to understand the insect distribution and to unveil the main factors linked to the genetic variability within and between populations.

Diversidade genética de Tibraca limbativentris Stål (Hemiptera: Pentatomidae) de Santa Catarina e do Rio Grande do Sul, usando marcadores RAPD / Genetic diversity of Tibraca limbativentris Stål (Hemiptera: Pentatomidae) of Santa Catarina and Rio Grande do Sul, Brazil, using RAPD

O trabalho objetivou testar protocolos de extração de DNA e caracterizar populações de Tibraca limbativentris, Stål, importante inseto-praga do arroz. Os insetos foram coletados em Joinville, Rio do Oeste e Turvo, em Santa Catarina, e Agudo, Uruguaiana, Pelotas e Palmares do Sul, no Rio Grande do Sul. Testaram-se seis protocolos de extração de DNA citados na literatura, e um novo protocolo adequado à espécie em questão. DNA de dez indivíduos de cada população foi extraído usando o melhor protocolo e reações de RAPD foram realizadas com dez iniciadores. O novo protocolo mostrou os melhores resultados e foi utilizado nas reações de PCR, que geraram 151 bandas polimórficas, permitindo acessar diferenças genéticas entre todas as populações; não ocorreram indivíduos de uma população agrupados com os de outra. A maior similaridade intrapopulacional foi encontrada em Uruguaiana (22 por cento), e a menor em Palmares do Sul (50 por cento), também a população mais divergente das demais. O valor Gst foi 0,5215, e de Nm 0,4588; esses valores refletem a pouca similaridade entre as populações. O menor Nm foi apresentado quando Palmares do Sul e Pelotas foram incluídos nas comparações, em consonância com a maior divergência apresentada por essas populações em relação às outras. Não se observou relação entre a distância geográfica e a similaridade genética das populações, o que refletirá o modelo de dispersão de T. limbativentris, ainda desconhecido. Estudos explorando as estratégias de dispersão da espécie poderiam ajudar no entendimento da distribuição do inseto, evidenciando qual a principal fonte de variabilidade genética.

The work was carried out to test DNA extraction protocols and to characterize populations of Tibraca limbativentris Stål, an important rice insect-pest. Insects were collected in Joinville, Rio do Oeste and Turvo, in Santa Catarina State, and Agudo, Uruguaiana, Pelotas and Palmares do Sul, in Rio Grande do Sul State, and six literature-referenced protocols, besides a new one, were tested. DNA from ten individuals of each population was extracted using the best protocol and RAPD reactions were carried out with ten initiators. The new protocol showed the best results and was used in the PCR reactions, that generated 151 polymorphic bands, allowing to access genetic differences among all the populations; no individuals from one population were clustered with individuals from another. The largest intrapopulacional similarity was found in Uruguaiana (22 percent), and the smallest in Palmares do Sul (50 percent), which was also the most divergent population in relation to the others. The Gst was 0.5215, and the Nm was 0.4588; these values reflect the low similarity between the populations. The smallest genic flow was obtained when Palmares do Sul and Pelotas were included in the comparisons, in accordance with the largest divergence of these two populations in relation to the others. There was no significant relation between geographic distance and genetic similarity, which can reflect unknown model of dispersion of T. limbativentris. New studies exploring the species dispersion strategies may help to understand the insect distribution and to unveil the main factors linked to the genetic variability within and between populations.

Ocorrência de Euphoria lurida (Fabricius) (Coleoptera: Scarabaeidae) em milho cultivado em Várzea no Rio Grande do Sul / Occurrence of Euphoria lurida (Fabricius) (Coleoptera: Scarabaeidae) in the corn cultivated in Lowland at Rio Grande do Sul State

Adultos de Euphoria lurida (Fabricius) são registrados como insetos-praga de algumas frutíferas e roseiras. Este é o primeiro relato de ocorrência de E. lurida na cultura do milho. Em março de 2006, adultos do inseto atacaram cerca de 15 por cento das plantas de milho em cultivo numa área de aproximadamente 1 ha. Os danos foram causados em plantas na fase reprodutiva, constatando-se perfurações dispostas transversal e longitudinalmente nos colmos logo acima da inserção da espiga. O ataque às espigas deu-se mais intensamente na sua porção apical, onde o inseto consumiu estilo-estigmas e grãos em formação.

Euphoria lurida adults (Fabricius) is registered as pests of some fruits and flowers. However, this is the first record of this insect in maize fields. In march, 2006 adults attacked about 15 percent of maize plants in an area with almost 1 ha. The damage occurred in plants in the reprodutive stage. Transversal and longitudinal holes were found in the stalks just above the ear insertion. The attack to the ear occurred more intensively in the upper part of the plant, where the insect fed on the silk and the filling grains.

[Occurrence of Euphoria lurida (Fabricius) (Coleoptera: Scarabaeidae) in the corn cultivated in Lowland at Rio Grande do Sul State]. / Ocorrência de Euphoria lurida (Fabricius) (Coleoptera: Scarabaeidae) em milho cultivado em Várzea no Rio Grande do Sul.

Euphoria lurida adults (Fabricius) is registered as pests of some fruits and flowers. However, this is the first record of this insect in maize fields. In march, 2006 adults attacked about 15% of maize plants in an area with almost 1 ha. The damage occurred in plants in the reproductive stage. Transversal and longitudinal holes were found in the stalks just above the ear insertion. The attack to the ear occurred more intensively in the upper part of the plant, where the insect fed on the silk and the filling grains.

Aflatoxin Production in a Meat Mix Model System in the Presence of Pediococcus and Lactobacillus.

The effect on aflatoxin production by Aspergillus parasiticus of eight individual strains of Pediococcus and Lactobacillus was determined. The study was conducted in an axenic cultural system in which irradiated meat was employed in the formulation of a meat medium. The medium composition and incubation temperatures were simulations of Brazilian salami processing conditions. All single cultures of A. parasiticus supported aflatoxin production. More aflatoxin was produced in samples treated by the addition of lactic acid than in nontreated ones. Aflatoxin was not detected when A. parasiticus was grown with lactic acid bacteria, although visible mold growth was observed in all such cultures.