Espectrofotometria de longo caminho óptico em espectrofotômetro de duplo-feixe convencional: uma alternativa simples para investigações de amostras com densidade óptica muito baixa

We describe the design and tests of a set-up mounted in a conventional double beam spectrophotometer, which allows the determination of optical density of samples confined in a long liquid core waveguide (LCW) capillary. Very long optical path length can be achieved with capillary cell, allowing measurements of samples with very low optical densities. The device uses a custom optical concentrator optically coupled to LCW (TEFLON® AF). Optical density measurements, carried out using a LCW of ~ 45 cm, were in accordance with the Beer-Lambert Law. Thus, it was possible to analyze quantitatively samples at concentrations 45 fold lower than that regularly used in spectrophotometric measurements.

Estratégias de pré-concentração em eletroforese capilar: parte 2. Manipulação da velocidade da fase dispersa/secundária

This work describes CE preconcentration strategies based on the effect of manipulation of the disperse/secondary velocity. Introduced by Terabe et al. in 1984, micellar electrokinetic chromatography is a powerful separation approach that increases the usage of electrokinetic phenomena for the separation of nonionic compounds. The main disadvantage of MEKC is the low concentration sensitivity associated with the limited optical path length for on-capillary photometric detection and the limited volume of sample solution that can be injected. This paper compiles on-line concentration strategies for neutral analytes by sample stacking and sweeping in micellar electrokinetic chromatography.

Phenotypic correlations and path analysis for plant architecture traits and grain production in three generations of cowpea

ABSTRACT The objective of this study was to analyze the phenotypic correlation and path analysis of traits related to plant architecture, earliness and grain yield in F2, BC1 and BC2 generations, from crosses between cowpea cultivars BRS Carijó and BR14 Mulato. Most phenotypic correlations of the examined traits were concordant in statistical significance, with approximate values ​​among the examined generations. For the trait seed weight, significant and positive phenotypic correlations were observed in the three generations only for the trait number of secondary branches. The values ​​of the direct effects were in agreement with the values ​​of the phenotypic correlations, which indicate true association by the phenotypic correlation among the traits of grain yield examined. Path analysis indicated that the selection of productive plants will result in early plants and an increased number of secondary branches. In F2, plants with shorter length of the main branch and shorter length of secondary branches can be obtained. The causal model explained 15 to 30% of the total variation in grain weight in relation to the traits examined. The analyses indicated the possibility of selecting plants with a higher and early grain yield, shorter length of primary branches and lower number of nodes, which are important variables for mechanical or semi-mechanical harvesting.

Rostrum length, mandible serration, and food and salivary canals areas of selected species of stink bugs (Heteroptera, Pentatomidae)

Laboratory studies were conducted to compare rostrum length morphology of mandible serration and area of food and salivary canals of Dichelops melacanthus (Dallas) (Dm), Euschistus heros (F.) (Eh), Nezara viridula (L.) (Nv), and Piezodorus guildinii (Westwood) (Pg) (Heteroptera: Pentatomidae). Nv showed the longest (5.9 mm) and Pg the shortest (3.5 mm) rostrum length; Dm and Eh were intermediate. Length and width of mandible tip areas holding serration was bigger for Nv (106.0 and 30.2 µm, respectively) and smaller for Pg (71.1 and 23.7 µm), with all species having four central teeth and three pairs of lateral teeth. The inner mandible surface showed squamous texture. Cross-section of food and salivary canals (Fc and Sc) indicated greater area for Nv and Dm compared to Eh and Pg; however, the ratio Fc/Sc, yielded the highest relative area for Pg.

Relationship between fruit traits of custard apple trees (Annona squamosa L.)

The objective of this study was to estimate simple and partial coefficients of correlation, as well as to divide their effects into direct and indirect using path analysis for custard apple tree traits. Twenty half-sibling progenies were evaluated in a randomized block design with five replicates, and plots consisting of four plants. Six traits were evaluated in the first cropping season (mean number of seeds per fruit and mean weight of the pericarp, pulp, pedicel, seeds per fruit, and the whole fruit), while five traits were evaluated in the first three cropping seasons (mean fruit length and width, total number of fruits ha-1, mean fruit weight (in both types of analyses), and fruit yield in kg ha-1). The results of this work led to the conclusion that doing selection based on simple correlation estimates may not be convenient, since not always a cause and effect relationship can be verified between two traits. Positive correlations were obtained between number of seeds and seed weight, and between number of fruits and yield. The greatest direct effects were those obtained for pulp weight on fruit weight and for mean number and weight of fruits on fruit yield. The most important indirect effects were obtained for number of seeds and pericarp weight, obtained via pulp weight, on fruit weight, and for fruit length and width, obtained via mean fruit weight, on fruit yield.

Effects of the length and timing of nighttime naps on task performance and physiological function

OBJECTIVE: To examine the effects of the length and timing of nighttime naps on performance and physiological functions, an experimental study was carried out under simulated night shift schedules. METHODS: Six students were recruited for this study that was composed of 5 experiments. Each experiment involved 3 consecutive days with one night shift (22:00-8:00) followed by daytime sleep and night sleep. The experiments had 5 conditions in which the length and timing of naps were manipulated: 0:00-1:00 (E60), 0:00-2:00 (E120), 4:00-5:00 (L60), 4:00-6:00 (L120), and no nap (No-nap). During the night shifts, participants underwent performance tests. A questionnaire on subjective fatigue and a critical flicker fusion frequency test were administered after the performance tests. Heart rate variability and rectal temperature were recorded continuously during the experiments. Polysomnography was also recorded during the nap. RESULTS: Sleep latency was shorter and sleep efficiency was higher in the nap in L60 and L120 than that in E60 and E120. Slow wave sleep in the naps in E120 and L120 was longer than that in E60 and L60. The mean reaction time in L60 became longer after the nap, and faster in E60 and E120. Earlier naps serve to counteract the decrement in performance and physiological functions during night shifts. Performance was somewhat improved by taking a 2-hour nap later in the shift, but deteriorated after a one-hour nap. CONCLUSIONS: Naps in the latter half of the night shift were superior to earlier naps in terms of sleep quality. However performance declined after a 1-hour nap taken later in the night shift due to sleep inertia. This study suggests that appropriate timing of a short nap must be carefully considered, such as a 60-min nap during the night shift.

Genetic relationships of Corynebacterium diphtheriae strains isolated from a diphtheria case and carriers by restriction fragment length polymorphism of rRNA genes

In the present study we report the results of an analysis, based on ribotyping of Corynebacterium diphtheriae intermedius strains isolated from a 9 years old child with clinical diphtheria and his 5 contacts. Quantitative analysis of RFLPs of rRNA was used to determine relatedness of these 7 C.diphtheriae strains providing support data in the diphtheria epidemiology. We have also tested those strains for toxigenicity in vitro by using the Elek's gel diffusion method and in vivo by using cell culture method on cultured monkey kidney cell (VERO cells). The hybridization results revealed that the 5 C.diphtheriae strains isolated from contacts and one isolated from the clinical case (nose case strain) had identical RFLP patterns with all 4 restriction endonucleases used, ribotype B. The genetic distance from this ribotype and ribotype A (throat case strain), that we initially assumed to be responsible for the illness of the patient, was of 0.450 showing poor genetic correlation among these two ribotypes. We found no significant differences concerned to the toxin production by using the cell culture method. In conclusion, the use of RFLPs of rRNA gene was successful in detecting minor differences in closely related toxigenic C.diphtheriae intermedius strains and providing information about genetic relationships among them.

EVIDENCE OF Leishmania (Leishmania) infantum INFECTION IN DOGS FROM JUIZ DE FORA, MINAS GERAIS STATE, BRAZIL, BASED ON IMMUNOCHROMATOGRAPHIC DUAL-PATH PLATFORM (DPP®) AND PCR ASSAYS

In Brazil, domestic dogs are branded as the primary reservoir for zoonotic visceral leishmaniasis, due to the clear positive correlation observed between human and canine infection rates. This study aimed to carry out a serological survey of canine visceral leishmaniasis (CVL) in dogs housed at a public kennel in the municipality of Juiz de Fora, Minas Gerais State, Brazil, using the immunochromatographic TR DPP® CVL rapid test. Additionally, conventional and/or real time PCR assay was used to detect and confirm L. infantum infection in the DPP positive dogs only. Of the 400 dogs studied, most did not present clinical signs for CVL (p < 0.05), and fifteen (3.8%) were seropositive in the DPP test. There was no statistically significant difference between the DPP seropositive dogs and the clinical signs of the disease (p > 0.05). Both conventional and real time PCR tests confirmed L. infantum infection in nine (75.0%) of the twelve DPP seropositive dogs that remained alive during the follow-up period. This study is the first seroepidemiologic survey of CVL held in the city of Juiz de Fora, and the results reinforce the idea that this disease is currently in a process of expansion and urbanization in Brazil. Furthermore, this study highlights the use of the DPP test as an alternative for diagnosing CVL in large and mid-sized cities, due to its ease of implementation.

Biology of Triatominae (Reduviidae Hemiptera) from North of Formosa County (Goiás-Brazil) I. Length of life cycle of Triatoma sordida (Stal. 1859)

In the present paper the life cycle of Triatoma sordida was studied. The mean length from egg to adult was 213 days. The mean length in days from each stage was: 24.3 (± 1.30) for the first. 32.8 (± 1.45) (2nd), 36.1 (± 1.50) (3rd), 44.6 (± 1.85) (4th) and 52.0 (± 1.92) (5th). The mean egg incubation períod was 23.2 (± 1.40). Overall mortality was 18.8% and egg viability was 82.5%.

Biology of Triatominae (Reduviidae, Hemiptera) from north of formosa county (Goiás - Brazil) II. Length of life cycle of Rhodnius Neglectus lent, 1954

In the present paper the life cycle of Rhodnius neglectus was studied. The mean length from egg to adult was 119 days. The mean length in day from each stage was: 17.4 (± 1.15) for first, 18.2 (± 1.28) for second, fourth and 29.8 (± 1.46) for fifth.

Biology of triatominae (Reduviidade, Hemiptera) from north of Formosa county (Goiás - Brazil). III: length of life cycle of Psammolestes tertius Lent and Jurberg 1965

In the present work the life cycle of Psammolestes tertius was studied. The mean length, in days, fromeach stage was: 26.3 (± 1.7) (1st), 28.6 (± 1.8) (2nd), 28.4 (± 1.8) (3rd), 32.2 (± 1.9) (4th) and 33.5 (± 5.8) (5th). The mean egg incubation period was 15.7 days (± 1.7). Overall mortality was 48.9% and egg viability was 65.7%.

Polymerase chain reaction and restriction fragment length polymorphism analysis of the ITS2 region for differatiation of Brazilian Biomphalaria intermediate hosts of the Schistosoma mansoni

We sequenced the internal transcribed spacer 2 of the ribosomal DNA (ITS2-DNAr) from the three Schistosoma mansoni intermediate hosts in Brazil: Biomphalaria glabrata, Biomphalaria tenagophila and Biomphalaria straminea. Analysis of a restriction map from those sequences allowed us to select putative restriction enzymes able to identify the snail species under study. Four restriction enzymes were used and HpaII provided simple species-specific profiles easily visualized in polyacrylamide gels. The use of ITS2 is advantageous as it provides a small fragment of 460 bp which may be easily amplified by PCR. In the current work, we showed that the amplification of ITS2-DNAr together with HpaII enzyme restriction is an auxiliary molecular tool for the morphological identification of such snails as well as for taxonomic and phylogenetic studies of neotropical planorbids.

Length and caliber of the rectosigmoid colon among patients with Chagas disease and controls from areas at different altitudes

Introduction In this study, we investigated radiological changes in the sigmoid colon in chagasic patients by comparing their colon lengths and caliber with those of non-chagasic living in the same region and non-chagasic living at high altitudes. Methods A total of 317 individuals were evaluated using clinical, serological and radiological methods and divided into three groups: 1) one hundred and nine non-chagasic individuals from Uberaba, Brazil; 2) sixty-one non-chagasic from Puno, Peru; 3) one hundred forty-seven chagasics examined in Uberaba, being 62 without megacolon (3A), 72 with megacolon (3B) and 13 with doubtful diagnosis of megacolon (3C). Results In group 2, the sigmoid colon had a significantly larger caliber (p=0.001) and the rectosigmoid colon was longer (p<0.001) than group 1. In subgroup 3A, the sigmoid colon (p<0.001) and rectum (p<0.001) had a significantly larger caliber and the rectosigmoid was longer (p<0.001) than that of the non-chagasic individuals. In subgroup 3B, the rectosigmoid was longer in all patients, and the caliber of the sigmoid was significantly larger than that of subjects in subgroups 3A and 3C (p<0.001). Conclusions Morphometric analysis confirms that Chagas disease may increase the caliber and length of the rectosigmoid. Our results suggest that altitude, ethnicity and diet may have influenced the size and length of the rectosigmoid of andean patients.

Molecular characterization of Mycobacterium tuberculosis isolates from Tehran, Iran by restriction fragment length polymorphism analysis and spoligotyping

Abstract: INTRODUCTION Characterization of Mycobacterium tuberculosis (MTB) isolates by DNA fingerprinting has contributed to tuberculosis (TB) control. The aim of this study was to determine the genetic diversity of MTB isolates from Tehran province in Iran. METHODS MTB isolates from 60 Iranian and 10 Afghan TB patients were fingerprinted by standard IS6110-restriction fragment length polymorphism (RFLP) analysis and spoligotyping. RESULTS The copy number of IS6110 ranged from 10-24 per isolate. The isolates were classified into 22 clusters showing ≥ 80% similarity by RFLP analysis. Fourteen multidrug-resistant (MDR) isolates were grouped into 4 IS6110-RFLP clusters, with 10 isolates [71% (95% CI: 45-89%)] in 1 cluster, suggesting a possible epidemiological linkage. Eighteen Iranian isolates showed ≥ 80% similarity with Afghan isolates. There were no strains with identical fingerprints. Spoligotyping of 70 isolates produced 23 distinct patterns. Sixty (85.7%) isolates were grouped into 13 clusters, while the remaining 10 isolates (14.2%) were not clustered. Ural (formerly Haarlem4) (n = 22, 31.4%) was the most common family followed by Central Asian strain (CAS) (n = 18, 25.7%) and T (n = 9, 12.8%) families. Only 1strain was characterized as having the Beijing genotype. Among 60 Iranian and 10 Afghan MTB isolates, 25% (95% CI: 16-37) and 70% (95% CI: 39-89) were categorized as Ural lineage, respectively. CONCLUSIONS A higher prevalence of Ural family MTB isolates among Afghan patients than among Iranian patients suggests the possible transmission of this lineage following the immigration of Afghans to Iran.

Ischemic heart disease. Hospitalization, length of stay and expenses in Brazil from 1993 to 1997

OBJECTIVE: To identify characteristics of the hospitalizations due to ischemic heart disease (IHD) made by the Single Health System -- "Sistema Único de Saúde (SUS) in Brazil from 1993 to 1997. METHODS: The information used came from records of permissions for hospitalization due to IHD (diseases codified from 410 to 414 by the International Disease Classification -- 9th Revision) furnished by the data bank DATASUS. The material studied was classified according to age, sex and length of hospitalization of the patients, and expenses to the system for IHD. RESULTS: IHD represents 1.0% of total hospitalizations. Angina pectoris was the most frequent type, occurring in 53.3% of the cases, followed by acute myocardial infarct (26.6%). This later was more frequent in men and angina in women . The majority of patients with IHD stayed hospitalized from 5 to 8 days. In the years of 1997 the expenses due to hospital treatment for IHD reach to 0.01% of Brazil's Gross Internal Product. In the studied period (1993-1997), IHD was responsible by 1.0% of hospitalizations, however it was 3.3% of the expenses of SUS. CONCLUSION: IHD is an important cause of hospitalization by the SUS; it has a rather high cost, indicating the need for preventive measures aimed at reducing exposure to risk factors and to decrease the incidence of this group of diseases in the nation.