Chagas' disease and social security: a case-control study in an urban area, Goiás, Brazil

One hundred and twenty subjects with Chagas' cardiopathy and 120 non-infected subjects were randomly selected from first time claimants of sickness benefits in the National Institute of Social Security (INPS) in Goiás. Cases of Chagas' cardiopathy were defined based on serological test, history of residence in an endemic area and, clinical and/or electrocardiogram (ECG) alterations suggestive of Chagas' cardiomyopathy. Controls were defined as subjects with at least two negative serological tests. Case and controls were compared in the analysis for age, sex, place of birth, migration history, socio-economic level, occupation, physical exertion at work, age at affiliation and years of contribution to the social security scheme, clinical course of their disease and ECG abnormalities. Chagas' disease patients were younger than other subjects and predominantly of rural origin. Non-infected subjects presented a better socio-economic level, were performing more skilled activities and had less changes of job than cases. No important difference was observed in relation to age at affiliation to INPS. About 60% of cases have claimed for benefits within the first four years of contribution while among controls this proportion was 38.5%. Cases were involved, proportionally more than controls, in "heavy" activities. A risk of 2.3 (95%CL 1.5 - 4.6) and 1.8 (95%CL 1.2- 3.5) was obtained comparing respectively "heavy" and "moderate" physical activity against "light". A relative risk of 8.5 (95%CL 4.9 - 14.8) associated with the presence of cardiopathy was estimated comparing the initial sample of seropositive subjects and controls. A high relative risk was observed in relation to right bundle branch block (RR = 37.1 95%CL = 8.8 - 155.6) and left anterior hemiblock (RR = 4.4, 95%CL = 2.1 - 9.1).

Modificación del coeficiente peso/área del pié en relación con la agregación en Tarebia granifera

OBJETIVO: Analizar la dispersión de los ejemplares de una población de Tarebia granifera y su relación con la modificación de los parámetros morfométricos. METODOS: Se colectó por parcelas incluyendo dos tipos de substratos en condiciones opuestas de agregación y se comparó la abundancia relativa tanto entre muestreos, como entre sustratos. Se delimitaron 7 clases de alto a las cuales se les determinó el coeficiente peso/área del pié, el cual se correlacionó con la talla por clase. Se evaluó experimentalmente si los individuos con menor carga del pié tienen mayor persistencia en substratos emergidos, así como la interacción entre dos grupos de clases de alto. RESULTADOS: La diferencia de la abundancia entre los muestreos fue de t=5.874 (p<0.001) y de t=10.15 (p<0.001) entre el substrato rocoso emergido y el arenoso, sólo en condiciones de alta agregación, en las que la carga del pié de los individuos más grandes se reduce con la talla (r=-0.98, p<0.05). Experimentalmente, la abundancia de los ejemplares de tallas opuestas está mutuamente limitada (r=-0.87, p<0.01), la altura del oleaje limita la abundancia de los ejemplares menores (r=-0.94, p<0.001) siendo tolerada por los mayores (r=0.72, p<0.05). La carga promedio del pie disminuye con la altura del oleaje (r=-0.93, p<0.001). CONCLUSIONES: Con elevada agregación los ejemplares mayores emigran hacia substratos de difícil conquista por los menores, que están limitados por la acción mecánica del medio. La disminución de la carga del pie facilita la dispersión de los individuos.

Harmonization of research and control in schistosomiasis

I have been employed by several different organizations during over 30 years working on schistosomiasis, the majority spent in endemic areas of Caribean, South America, Africa and the Western Pacific. Much of the work is best classified as applied research but sometimes it strayed to the extremes of either public health control programmes or pure research. Over this period, there have been several significant research developments that have altered our whole approach to control. Ideally, research and control should complement each other but, in reality, they sometimes have conflicting objectives. Public health workers understandably wish to provide immediate, shot-term protection to the communities in their care, but research workers may, within ethical limits, reasonably want to observe untreated communities for extended periods in order to understand the underluing process of transmission, disease pathogenesis and immunity to help develop more effective control measures. An example of this situation has occured recently in Senegal where water development projects seem to have favoured the introduction and spreed of Schistosoma mansoni in the Senegal River Basin. I have been asked to be the scientific consultant to the newly formed ESPOIR programme, linking European research organizations and the Senegal Ministry of Health, to reconcile the conflictiong aims of public health workers, wishing to use whatever funds can be obtained for an immediate chemotherapy to try to eliminate the focus, at present confined to the vicinity of a relatively small, commercially run sugar irrigation scheme; and research workers who see a rare chance to study the development of immune mechanisms in a adults in a community not previously exposed to the infection. This information could prove invaluable in understanding the development of immunity and the pathogenesis of disease, leading eventually to the development of vaccines to revolutionise the future approach to schistosomiasis...

Certifying achievement in the control of Chagas disease native vectors: what is a viable scenario?

As an evaluation scheme, we propose certifying for “control”, as alternative to “interruption”, of Chagas disease transmission by native vectors, to project a more achievable and measurable goal and sharing good practices through an “open online platform” rather than “formal certification” to make the key knowledge more accumulable and accessible.

Control system for forced-air cooling of horticultural products

This work is a study of the implementation of a classical controller using a tuning method referred to as IMC (Internal Model Control) and aimed at the reduction of electrical energy consumption by the appropriate relation between energy consumption and the cooling time with forced air. The supervisory system installed was able to manipulate the variable of frequency of the signal power of the exhaust fan engine (forced air module), to accelerate or decelerate the loss of heat from the product to be cooled by airflow variation that passes through the mass of the produce. The results demonstrated a reduction in energy consumption from 64% and an increase of only 8% in the cooling time to the system using PI/IMC (Proportional - Integral with IMC) tuning method compared with the system in its operating nominal condition. This PI/IMC control may be implemented directly in a frequency converter, without the need to purchase a computer or PLC (programmable logic controller) to run the dedicated application, increasing its economical viability.

Internal quality control indicators of cervical cytopathology exams performed in laboratories monitored by the External Quality Control Laboratory

PURPOSE: To evaluate the impact of continued education provided by an external quality control laboratory on the indicators of internal quality control of cytopathology exams.METHODS: The internal quality assurance indicators for cytopathology exams from 12 laboratories monitored by the External Quality Control Laboratory were evaluated. Overall, 185,194 exams were included, 98,133 of which referred to the period preceding implementation of a continued education program, while 87,061 referred to the period following this intervention. Data were obtained from the Cervical Cancer Database of the Brazilian National Health Service.RESULTS: Following implementation of the continued education program, the positivity index (PI) remained within recommended limits in four laboratories. In another four laboratories, the PI progressed from below the limits to within the recommended standards. In one laboratory, the PI remained low, in two laboratories, it remained very low, and in one, it increased from very low to low. The percentage of exams compatible with a high-grade squamous intraepithelial lesion (HSIL) remained within the recommended limits in five laboratories, while in three laboratories it progressed from below the recommended levels to >0.4% of the total number of satisfactory exams, and in four laboratories it remained below the standard limit. Both the percentage of atypical squamous cells of undetermined significance (ASC-US) in relation to abnormal exams, and the ratio between ASC-US and intraepithelial lesions remained within recommended levels in all the laboratories investigated.CONCLUSION: An improvement was found in the indicators represented by the positivity index and the percentage of exams compatible with a high-grade squamous intraepithelial lesion, showing that the role played by the external quality control laboratory in providing continued education contributed towards improving laboratory staff skills in detecting cervical cancer precursor lesions.

Nonlinear dynamics and control of multibody systems

The dynamics of flexible systems, such as robot manipulators , mechanical chains or multibody systems in general, is becoming increasingly important in engineering. This article deals with some nonlinearities that arise in the study of dynamics and control of multibody systems in connection to large rotations. Specifically, a numerical scheme that adresses the conservation of fundamental constants is presented in order to analyse the control-structure interaction problems.

S-metolachlor efficacy on the control of Brachiaria decumbens, Digitaria horizontalis, and Panicum maximum in mechanically green harvested sugarcane

The aim of this study was to assess the efficacy of S-metolachlor applied in pre-emergence conditions for the control of Brachiaria decumbens, Digitaria horizontalis, and Panicum maximum in sugar cane mechanically harvested without previous burning of the crop (green harvest) with the crop residue either left or not on the soil surface. The experiments were established in the field according to a randomized complete block design with four repetitions in a 7 x 2 split-plot scheme. In the plots, five herbicide treatments were studied (S-metolachlor at 1.44, 1.92, and 2.40 kg ha-1, clomazone at 1.20 kg ha-1, and isoxaflutole at 0.188 kg ha-1), and two control treatments with no herbicide application. In the subplots, the presence or absence of sugar cane crop residue on the soil surface was evaluated. S-metolachlor efficacy was not hampered by either 14 or 20 t ha-1 of sugar cane crop residue on the soil surface. When sugar cane crop residue was covering the soil surface, S-metolachlor at a rate of 1.44 kg ha-1 resulted in weed control similar at their larger rates, where as without the presence of crop residue, S-metolachlor controlled B. decumbens, D. horizontalis, and P. maximum at the rates of 1.92, 1.44, and 1.92 kg ha-1, respectively. The herbicides clomazone and isoxaflutole were effective for the studied species, independently of the crop residue covering the soil surface. S-metolachlor caused no visible injury symptoms to the sugar cane plant. Clomazone and isoxaflutole caused visible injuries to the sugar cane plant. None of the herbicides negatively affected the number of viable culms m² or the culm height and diameter.

Meal-feeding scheme: twenty years of research in Brazil

Naomi Shinomiya Hell was the first researcher to investigate the physiological adaptations to a meal-feeding scheme (MFS) in Brazil. Over a period of 20 years, from 1979 to 1999, Naomi's group determined the physiological and metabolic adaptations induced by this feeding scheme in rats. The group showed the persistence of such adaptations even when MFS is associated with moderate exercise training and the performance to a session of intense physical effort. The metabolic changes induced by the feeding training were discriminated from those caused by the effective fasting period. Naomi made an important contribution to the understanding of the MFS but a lot still has to be done. One crucial question still remains to be satisfactorily answered: what is the ideal control for the MFS?

Chemical treatment of papaya seeds aiming at long-term storage and control of damping off

Damping off is a nursery disease of great economic importance in papaya and seed treatment may be an effective measure to control. The aim of this work was to evaluate the quality of papaya seeds treated with fungicides and stored under two environmental and packaging conditions. Additionally, the efficiency of fungicide treatments in the control of damping-off caused by Rhizoctonia solani was evaluated. Papaya seeds were treated with the fungicides Captan, Tolylfluanid and the mixture Tolylfluanid + Captan (all commercial wettable powder formulations). Seeds of the control group were not treated. The seeds were stored for nine months in two conditions: packed in aluminum coated paper and kept at 7 ± 1ºC and in permeable kraft paper and kept in non-controlled environment. At the beginning of the storage and every three months the seed quality (germination and vigor tests), emergence rate index, height, dry mass and damping of plants in pre and post-emergence (in contaminated substrate and mycelia-free substrate) were analyzed. Both storage conditions as well as the fungicide treatments preserved the germination and seed vigor. In the infested substrate, seedling emergence was favored by fungicides, but in post-emergence, fungicides alone did not control the damping off caused by R. solani. Symptoms of damping off were not observed in the clean substrate. The results showed that the fungicide treatments may be used to pretreat papaya seed for long-term storage and commercialization.

Silicon in plant disease control

All essential nutrients can affect the incidence and severity of plant diseases. Although silicon (Si) is not considered as an essential nutrient for plants, it stands out for its potential to decrease disease intensity in many crops. The mechanism of Si action in plant resistance is still unclear. Si deposition in plant cell walls raised the hypothesis of a possible physical barrier to pathogen penetration. However, the increased activity of phenolic compounds, polyphenol oxidases and peroxidases in plants treated with Si demonstrates the involvement of this element in the induction of plant defense responses. The studies examined in this review address the role of Si in disease control and the possible mechanisms involved in the mode of Si action in disease resistance in plants.

Postharvest biological control of brown rot in peaches after cold storage preceded by preharvest chemical control 1

ABSTRACT Pathogenic fungi cause skin darkening and peach quality depreciation in post harvest. Therefore, alternative techniques to chemical treatment are necessary in order to reduce risks to human health. The aim of this study was to evaluate the effect of the application of Trichoderma harzianum in association with different fungicides applied before harvest to 'Eldorado' peaches for brown rot control and other quality parameters during storage. The treatments consisted of five preharvest fungicide applications (control, captan, iprodione, iminoctadine and tebuconazole) associated with postharvest application of T. harzianum, after cold storage (with and without application), in three evaluation times (zero, two and four days at 20 °C), resulting in a 5x2x3 factorial design. The application of T. harzianum only brought benefits to the control of brown rot when combined with the fungicide captan, at zero day shelf life. After two days, there was a greater skin darkening in peaches treated with T. harzianum compared with peaches without the treatment, except for peaches treated with the fungicide iprodione and T. harzianum The application of T. harzianum during postharvest showed no benefits for the control of brown rot, however, the association with fungicides reduced the incidence of Rhizopus stolonifer during the shelf life.

Co-inoculation of Rhizobium tropici and Azospirillum brasilense in common beans grown under two irrigation depths

ABSTRACT The alternative technique of co-inoculation or mixed inoculation with symbiotic and non-symbiotic bacteria has been studied in leguminous plants. However, there are few field studies with common beans and under the influence of the amount of irrigated water. Thus, the objective of this study was to evaluate the efficiency of inoculation and co-inoculation of common beans with Rhizobium tropici and Azospirillum brasilense under two irrigation depths. The experiment was carried out in the winter of 2012 and 2013, in Selvíria, state of Mato Grosso do Sul. The experimental design was composed of randomized blocks in split-plot scheme with two irrigation depths in the plots (recommended for common beans and 75% of the recommended) and five forms of nitrogen (N) supply in the split-plots (control non-inoculated with 40 kg ha- 1 of N in topdressing, 80 kg ha- 1 of N in topdressing, A. brasilense inoculation with 40 kg ha-1 of N in topdressing, R. tropici inoculation with 40 kg ha-1 of N in topdressing, and co-inoculation of A. brasilense and R. tropici with 40 kg ha- 1 of N in topdressing) with four repetitions. Co-inoculation increased nodulation in the second year of cultivation. None of the evaluated treatments increased the grain yield in relation to non-inoculated control with 40 kg ha-1 of nitrogen in topdressing, which presented average yield of 2,200 kg ha-1. The use of 75% of the recommended irrigation depth provides similar grain yield to the recommended irrigation depth in common beans cropped in winter.