Light-Emitting Diode (LED) Traps Improve the Light-Trapping of Anopheline Mosquitoes.

Numerous advantages over the standard incandescent lamp favor the use of light-emitting diodes (LEDs) as an alternative and inexpensive light source for sampling medically important insects in surveillance studies. Previously published studies examined the response of mosquitoes to different wavelengths, but data on anopheline mosquito LED attraction are limited. Center for Disease Control and Prevention-type light traps were modified by replacing the standard incandescent lamp with 5-mm LEDs, one emitting at 520 nm (green) and the other at 470 nm (blue). To test the influence of moon luminosity on LED catches, the experiments were conducted during the four lunar phases during each month of the study period. A total of 1,845 specimens representing eight anopheline species were collected. Anopheles (Nyssorhynchus) evansae (35.2%) was the most frequently collected, followed by An. (Nys.) triannulatus (21.9%), An. (Nys.) goeldii (12.9%), and An. (Nys.) argyritarsis (11.5%). The green LED was the most attractive light source, accounting for 43.3% of the individuals collected, followed by the blue (31.8%) and control (24.9%) lights. The LED traps were significantly more attractive than the control, independent of the lunar phase. Light trapping of anopheline mosquitoes was more efficient when the standard incandescent lamp was replaced with LEDs, regardless of the moon phase. The efficiency of LEDs improves light trapping results, and it is suggested that the use of LEDs as an attractant for anopheline mosquitoes should be taken into consideration when sampling anopheline mosquitoes.

Infestation of Brazilian Peridomiciliary Areas by Culicoides (Diptera: Ceratopogonidae) in Humid and Semihumid Climates.

This study investigates Culicoides infestation in peridomestic environments in two villages in Maranhão, one with hot and humid climate and the other with semihumid climate. We evaluated the composition, richness, abundance, and seasonality of species. We captured insects using CDC light traps installed in animal shelters once a month, from 6 pm to 6 am, for 24 mo (May 2012 to April 2014). In this study, 17 species were found. Of these, 10 occurred simultaneously in two areas; six were found only in hot and humid area, while one occurred only in the semihumid area. Species richness was higher in the hot and humid climate (16 species) than in the semihumid (11 species). The rank of abundance was uneven across areas: C. foxi, C. insignis, C. filariferus, C. ignacioi, and C. flavivenula were dominant in the hot and humid area, and C. ignacioi, C. foxi, C. filariferus, C. insignis, and C. boliviensis in the semihumid. Midges were more abundant in the rainy season in both areas. This result reveals a diversified fauna of midges, with variable abundance of rank according to the area, prevailing in the rainy season and in the Amazon area. It also highlights the need for health monitoring in order to contain the infestation by these insects in peridomestic environments, taking into account that some species can be effective vectors of arboviruses in the Amazon and northeastern Maranhão.

An Evaluation of Light-Emitting Diode (LED) Traps at Capturing Phlebotomine Sand Flies (Diptera: Psychodidae) in a Livestock Area in Brazil.

A study to evaluate the use of light-emitting diodes (LEDs) as an attractant for phlebotomine sand flies at two animal pens in a livestock area in Brazil was performed. Light-suction traps were operated overnight with the following light sources: green, blue, and incandescent (control) lights. In total, 22 individual collections were made at each site and 44 with each trap type. In total, 2,542 specimens belonging to 14 phlebotomine species were collected. The most abundant species in the light traps were Nyssomyia whitmani, Evandromyia evandroi, Micropygomyia goiana, Lutzomyia longipalpis, and Bichromomyia flaviscutellata Taking the two sites together, the green-LED light was the most attractive, followed by the blue and incandescent lights, and the difference between the green-LED and the control was statistically significant. Most species were green-biased at both sites, but some species-specific differences were observed. However, even with these differences, the standard incandescent light was outcompeted by LEDs. The green-LED-biased response observed in the present study, together with numerous advantages in favor of LEDs, suggests that the green-LED light source can be used as an effective substitute for the currently used incandescent bulb in monitoring traps for phlebotomine sand flies in Brazil.

Ecology of phlebotomines (Diptera: Psychodidae) in a transitional area between the Amazon and the Cerrado in the State of Maranhão, Brazil.

The Amazon rainforest and the Brazilian Cerrado both possess high phlebotomine diversity. The fragmentation of these habitats has resulted in the appearance of human cases of cutaneous leishmaniasis. In one altered area of mixed primary vegetation (forest and Cerrado) and its adjacent settlement in the northeast state of Maranhão, Brazil, evidence exists for the active transmission of cutaneous leishmaniasis. Accordingly, an entomological investigation was performed in both the forest and the settlement to compare the phlebotomine vector faunain each environment. The study was conducted from September 2009 to August 2010 in the municipality of Itapecuru Mirim in the state of Maranhão, Brazil. The phlebotomine species were captured using 24 light Center for Disease Control and Prevention traps that were placed in the forest and the settlement (peridomicile and intradomicile). The similarity between the phlebotomine compositions in the forest and those in the settlement was determined using a Principal Coordinate Analysis based on a dissimilarity matrix that was calculated using the Bray-Curtis index (relative abundance) and the Jaccard index (presence and absence of species). In total, 29 Lutzomyia species and one Brumptomyia species were collected. The phlebotomines were diverse and abundant in both the forest fragment (27 species, 4,606 specimens) and the settlement (22 species, 753 specimens). The most abundant species were L. infraspinosa (25%), L. davisi (21%), L. antunesi (21%), L. longipalpis (9%), L. saulensis (6%), L. flaviscutellata (5%), and L. wellcomei (4%). Some species were found strictly in the forest, other species were exclusive to the anthropic environment, and some species colonized both of the studied environments. The phlebotomines adaptation to these modified environments explains the autochthonous outbreak of cutaneous leishmaniasis.

Genetic differentiation in natural populations of Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae) with different phenotypic spot patterns on tergites in males.

Entomological surveys in the state of Maranhão have recorded morphologically distinct populations of Lutzomyia longipalpis (Lutz & Neiva). Some populations have one pair of spots (1S) on the fourth tergite, while others have two pairs (2S) on the third and fourth tergites of males. In the present study we investigated the degree of genetic polymorphism among four populations in the municipalities of Caxias, Codó and Raposa, in the state of Maranhão, Brazil, by using RAPD (Random Amplified Polymorphic DNA) markers. A total of 35 loci were identified, of which 30 were polymorphic. The highest polymorphism was observed with primer OPA 4, which produced 11 different profiles. Genetic diversity was assessed using grouping methods that produced a dendrogram in which the genotypes could be clearly separated into two main clades according to the number of spots on the male abdominal tergites. One cluster contained the populations from Caxias and Codó, and the other was formed by the populations from Raposa and Codó. The results of our RAPD analysis showed a clear separation between the populations with one and two pairs of spots. The epidemiologic significance of this genetic differentiation should be investigated in future studies.

The effect of fragmentation on phlebotomine communities (Diptera: Psychodidae) in areas of ombrophilous forest in São Luís, state of Maranhão, Brazil.

The aim of this study was to determine whether an edge effect could be observed in the structure and composition of phlebotomine assemblages in five forest fragments on São Luís Island. The study also investigated whether there were any differences in species along the forest edge-to-interior gradient and in species richness and abundance between the fragments studied. To capture the insects a transect was defined in each fragment, and eight light traps were set up at 15 m intervals from the edge. Phlebotomines were found in all fragments, and a total of 2972 specimens (1188 males and 1784 females) belonging to 24 species were collected. Of these, the most abundant was Lutzomyia antunesi (Coutinho), followed by Brumptomyia avellari (Costa Lima), L. infraspinosa (Mangabeira), L. flaviscutellata (Mangabeira), L. claustrei Abonnenc, Léger & Fauran, L. wellcomei (Fraiha, Shaw & Lainson), L. sordellii (Shannon & Del Ponte) and L. paraensis (Costa Lima). No significant differences were observed in the number of individuals or species along the edge-to-interior gradient. However, a higher distribution of some species in certain regions of the forest could be observed graphically. There was no correlation between fragment size and the number of species or individuals.

Biotransformation and genotoxic biomarkers in mullet species (Liza sp.) from a contaminated coastal lagoon (Ria de Aveiro, Portugal).

The aim of the present study was to assess liver ethoxyresorufin-O-deethylase (EROD) activity and erythrocytic nuclear abnormalities (ENA) frequency in three mullet species, as biotransformation and genotoxicity biomarkers, respectively, for monitoring aquatic ecosystems. Specimens of Liza aurata, Liza ramada and Liza saliens were caught bimonthly, between May 2000 and March 2001, at nine stations in the Ria de Aveiro (Portugal), a polluted coastal lagoon. The survey revealed two critical areas (Vagos and Carregal) where it was observed elevated EROD activity and ENA frequency, comparing to the reference sites. The results often reflect a contamination by a mixture of pollutants, from point and non-point sources. Nevertheless, the responses observed at Vagos are probably attributable to high polycyclic aromatic hydrocarbon (PAH) water levels measured at that station. All species were able to detect inter-site differences; however L. aurata seems to be the most appropriate bio-indicator due to its larger geographical distribution and abundance during the whole year. The adopted biomarkers, applied to mullet species, can be successfully employed for biomonitoring anthropogenic contamination in both Atlantic and Mediterranean European coastal waters.

Population dynamics of euglossinae bees (Hymenoptera, Apidae) in an early second-growth forest of Cajual Island, in the state of Maranhão, Brazil.

A study was conducted in an early second-growth forest aiming at knowing the richness, relative abundance, seasonal distribution, and hourly frequency of euglossine bees, and their association with scent baits. Male bees were attracted to cineole, vanillin, methyl salicylate, and eugenol. The baits were hooked 1.5 m high and 6 m from one another. The specimens were collected from December 1997 to November 1998, once a month, from 7:00 to 17:00 h. A total of 339 male euglossine bees were caught, accounting for 19 species and four genera. The most common species was E. cordata, making up 69.9% of the individuals, followed by E. truncata (2.3%), E. violaceifrons, and E. smaragdina (2.1%). The most attractive scent was cineole, which baited 87% of the specimens and 73.7% of the species. Vanillin, the second most visited bait, eured 7.6% of the specimens and 26.3% of the species. E. surinamensis was only collected with this bait. Methyl salicylate and eugenol baited combined 2.6% of the specimens. However, by species numbers Methyl salicylate attracted 21% whereas eugenol was attractive for 15.8% of them. In general, the species were more abundantly found in the rainy season (January-June). The hourly activity data showed that the euglossine bees were attracted to the baits all day long, but at a higher frequency in the morning period, peaking between 8:00 and 10:00 h.

Population dynamics of Euglossinae bees (Hymenoptera, Apidae) in an early second-growth forest of Cajual Island, in the State of Maranhão, Brazil

A study was conducted in an early second-growth forest aiming at knowing the richness, relative abundance, seasonal distribution, and hourly frequency of euglossine bees, and their association with scent baits. Male bees were attracted to cineole, vanillin, methyl salicylate, and eugenol. The baits were hooked 1.5 m high and 6 m from one another. The specimens were collected from December 1997 to November 1998, once a month, from 7:00 to 17:00 h. A total of 339 male euglossine bees were caughts, accounting for 19 species and four genera. The most common species was E. cordata, making up 69.9% of the individuals, followed by E. truncata (2.3%), E. violaceifrons, and E. smaragdina (2.1%). The most attractive scent was cineole, which baited 87% of the specimens and 73.7% of the species. Vanillin, the second most visited bait, eured 7.6% of the specimens and 26.3% of the species. E. surinamensis was only collected with this bait. Methyl salicylate and eugenol baited combined 2.6% of the specimens. However, by species numbers Methyl salicylate attracted 21% whereas eugenol was attractive for 15.8% of them. In general, the species were more abundantly found in the rainy season (January-June). The hourly activity data showed that the euglossine bees were attracted to the baits all day long, but at a higher frequency in the morning period, peaking between 8:00 and 10:00 h.

Realizou-se o presente estudo em uma área de capoeira, objetivando conhecer a riqueza, a abundância relativa, a distribuição sazonal, a freqüência horária e a associação de espécies de Euglossinae com as iscas odoríferas. As abelhas (machos) foram atraídas por iscas de cineol, vanilina, salicilato de metila e eugenol, as quais encontravam-se a 1,5 m do solo e a uma distância de 6 m uma das outras. As coletas foram realizadas de dezembro/97 a novembro/98, uma vez por mês, das 7 às 17 horas. Foram amostrados 339 machos, distribuídos em 19 espécies e 4 gêneros. A espécie mais abundante foi E. cordata, representada por 69,9% dos indivíduos, seguida por E. truncata (2,9%), E. violaceifrons e E. smaragdina (2,1%). O composto mais atrativo foi o cineol, que atraiu 87% dos indivíduos e 73,7% das espécies. Vanilina atraiu 7,6% dos indivíduos e 26,3% das espécies, sendo a segunda isca mais visitada. E. surinamensis foi capturada somente nessa essência. Salicilato de metila e eugenol atraíram juntos 2,6% dos indivíduos. Salicilato de metila atraiu 21% das espécies, eugenol ,15,8%. Em geral, as espécies apresentaram maior freqüência nos meses chuvosos (janeiro-junho). Os machos freqüentaram as essências durante todo o dia, porém com maior freqüência no período matutino, cujo pico observado foi entre 8 e 10 horas.

Population dynamics of Euglossinae bees (Hymenoptera, Apidae) in an early second-growth forest of Cajual Island, in the State of Maranhäo, Brazil

A study was conducted in an early second-growth forest aiming at knowing the richness, relative abundance, seasonal distribution, and hourly frequency of euglossine bees, and their association with scent baits. Male bees were attracted to cineole, vanillin, methyl salicylate, and eugenol. The baits were hooked 1.5 m high and 6 m from one another. The specimens were collected from December 1997 to November 1998, once a month, from 7:00 to 17:00 h. A total of 339 male euglossine bees were caughts, accounting for 19 species and four genera. The most common species was E. cordata, making up 69.9 percent of the individuals, followed by E. truncata (2.3 percent), E. violaceifrons, and E. smaragdina (2.1 percent). The most attractive scent was cineole, which baited 87 percent of the specimens and 73.7 percent of the species. Vanillin, the second most visited bait, eured 7.6 percent of the specimens and 26.3 percent of the species. E. surinamensis was only collected with this bait. Methyl salicylate and eugenol baited combined 2.6 percent of the specimens. However, by species numbers Methyl salicylate attracted 21 percent whereas eugenol was attractive for 15.8 percent of them. In general, the species were more abundantly found in the rainy season (January-June). The hourly activity data showed that the euglossine bees were attracted to the baits all day long, but at a higher frequency in the morning period, peaking between 8:00 and 10:00 h

Structure refinement of the aldehyde oxidoreductase from Desulfovibrio gigas (MOP) at 1.28 A.

The sulfate-reducing bacterium aldehyde oxidoreductase from Desulfovibrio gigas (MOP) is a member of the xanthine oxidase family of enzymes. It has 907 residues on a single polypeptide chain, a molybdopterin cytosine dinucleotide (MCD) cofactor and two [2Fe-2S] iron-sulfur clusters. Synchrotron data to almost atomic resolution were collected for improved cryo-cooled crystals of this enzyme in the oxidized form. The cell constants of a=b=141.78 A and c=160.87 A are about 2% shorter than those of room temperature data, yielding 233,755 unique reflections in space group P6(1)22, at 1.28 A resolution. Throughout the entire refinement the full gradient least-squares method was used, leading to a final R factor of 14.5 and Rfree factor of 19.3 (4sigma cut-off) with "riding" H-atoms at their calculated positions. The model contains 8146 non-hydrogen atoms described by anisotropic displacement parameters with an observations/parameters ratio of 4.4. It includes alternate conformations for 17 amino acid residues. At 1.28 A resolution, three Cl- and two Mg2+ ions from the crystallization solution were clearly identified. With the exception of one Cl- which is buried and 8 A distant from the Mo atom, the other ions are close to the molecular surface and may contribute to crystal packing. The overall structure has not changed in comparison to the lower resolution model apart from local corrections that included some loop adjustments and alternate side-chain conformations. Based on the estimated errors of bond distances obtained by blocked least-squares matrix inversion, a more detailed analysis of the three redox centres was possible. For the MCD cofactor, the resulting geometric parameters confirmed its reduction state as a tetrahydropterin. At the Mo centre, estimated corrections calculated for the Fourier ripples artefact are very small when compared to the experimental associated errors, supporting the suggestion that the fifth ligand is a water molecule rather than a hydroxide. Concerning the two iron-sulfur centres, asymmetry in the Fe-S distances as well as differences in the pattern of NH.S hydrogen-bonding interactions was observed, which influences the electron distribution upon reduction and causes non-equivalence of the individual Fe atoms in each cluster.

[Study of post-myocardial infarction ventricular aneurysms with equilibrium radionuclide angiography. Significance of Fourier analysis]. / Estudo dos aneurismas ventriculares pós-enfarte do miocárdio pela angiografia de radionuclidos de equilíbrio. Importância da análise de Fourier.

The concept of left ventricular aneurysm has been a subject of controversy and it's not yet completely settled. This has some implications on the patients selection for surgery and explains the various non-invasive methods so far developed for the clinical assessment of patients with ventricular aneurysms. Seventy-one patients with ischemic heart disease, 65 with recent myocardial infarction, were studied by equilibrium radionuclide angiography (ERNA) in order to define left ventricular wall motion abnormalities. One hundred ERNA were undertaken, through the usual erytrocites in vivo labelling technic, employing a GE 400 T Gama-Camera GP. Image acquisition was through 400 cardiac cycles, on LAO (30 and 60 degrees) and left lateral. PAGE protocol was employed. Fourier transform was used in the present work to obtain phase and amplitude images, which actually became the main criteria to define aneurysmatic areas. Global ejection fraction, regional wall motion and regional ejection fraction were other parameters investigated. Wall motion abnormalities have been identified in all the 65 patients having suffered a myocardial infarction. Extensive areas of akinesia or localized dyskinesia were present in 40 patients (16.5%), while remainder 25 had just localized hypoakinesia. Phase image enabled the selection of LV areas of contraction delay in 19 of the 40 patients with extensive wall motion abnormalities (Group I). In such Group I we could identify an LV area with contrasting colour, defining the aneurysmatic LV portion. In the order 21 patients with extensive akinesia, no significant changes of colour were present on ventricular phase image (Group II) meaning absence of aneurysm. No phase disturbances were seen in the remainder 25 patients with MI (Group III) and the 6 patients with CAD without MI had normal phase images (Group IV). The percentage of akinetic segments was 39.1 and 35.4 in Group I and II, respectively (p = .53) while it was significantly lower in Group III 17.9%; p < .0001). LV ejection fraction was statistically different in the four groups considered (I = 30.0% +/- 3.7; II = 39.9% +/- 2.9; III = 49.0% +/- 2.5; IV = 62.0% +/- 3.2). The degree of phase delay in aneurysmatic zones was quantified by the phase histogram. Average value of phase for the left ventricle was 129.7 +/- 8.4 degrees, and for the aneurysm it was 238.0 +/- 5.0 with an average phase delay of 104.8 +/- 4.1 degrees. The association of phase and amplitude images and the measurements of phase and amplitude values on the histograms allowed the distinction of akinetic aneurysm (phase delay and low amplitude) from the dyskinetic aneurysms (phase delay and high amplitude). Half of the isotopic diagnosis of aneurysms have been confirmed by classic contrast angiography, and a third of then have undergone surgery. The two dyskinetic aneurysms that have been submitted to aneurysmectomy had pos-operative improvement of LV function. On summary, phase and amplitude analysis by the Fourier method, which is independent of LV geometry, showed that LV regions with high phase values are associated with severe regional wall motion abnormalities and low ejections fractions. The definition of the sequence and amplitude of ventricular contraction allows the distinction of akinetic and dyskinetic aneurysms, anticipating the method as a valid contribution for the screening of patients likely to benefit from aneurysmectomy.

Sandflies (Diptera: Psychodidae) of the Amazônia of Maranhão. V. Seasonal occurrence in ancient colonization area and endemic for cutaneous leishmaniasis.

In this paper, the seasonal abundance of 25 sandfly species (1 of the Brumptomyia genus and 24 of the Lutzomyia genus) found at P1V5, municipal district of Buriticupu, Maranhão State, is discussed. The capture was carried out from 18:00 P.M. to 6:00 A.M., once a month, from January to December 1996. CDC light traps were set up in the forest, in the peri and intradomicile environments. Five species were only found in the rainy season (January to June), being represented by one or two individuals; eight species occurred only in the dry season (July to December) and eleven species appeared in both seasons. The most frequent species in the dry period were: L. whitmani (26.3%), L. serrana (23%), L. choti (22.8%), L. evandroi (7.5%), L. longipalpis (5.8%), L. termitophila (3.3%), L. shannoni (3%) and L. migonei (2.5%). In the rainy season, L. whitmani was the prevailing species (74%), followed by L. termitophila (4%), L. umbratilis (3.4%), L. serrana (2.8%), L. evandroi (2,8%) and L. claustrei (2.4%). L. whitmani was thought to be an annual species, occurring in the entire year of study. The others species, with exception to L. serrana and L. evandroi, showed a seasonal, punctual or peripheric pattern.

Emerging Chagas disease: trophic network and cycle of transmission of Trypanosoma cruzi from palm trees in the Amazon.

A trophic network involving molds, invertebrates, and vertebrates, ancestrally adapted to the palm tree (Attalaea phalerata) microhabitat, maintains enzootic Trypanosoma cruzi infections in the Amazonian county Paço do Lumiar, state of Maranhão, Brazil. We assessed seropositivity for T. cruzi infections in the human population of the county, searched in palm trees for the triatomines that harbor these infections, and gathered demographic, environmental, and socioeconomic data. Rhodnius pictipes and R. neglectus in palm-tree frond clefts or in houses were infected with T. cruzi (57% and 41%, respectively). Human blood was found in 6.8% of R. pictipes in houses, and 9 of 10 wild Didelphis marsupialis had virulent T. cruzi infections. Increasing human population density, rain forest deforestation, and human predation of local fauna are risk factors for human T. cruzi infections.

[Hourly frequency and seasonality of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) on São Luís Island, Maranhão, Brazil]. / Freqüência horária e sazonalidade de Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) na Ilha de São Luís, Maranhão, Brasil.

This article presents the hourly and seasonal distribution of the Lutzomyia longipalpis sand fly captured on São Luís Island, Maranhão State. A total of 11,200 specimens were captured during monthly use of CDC light traps indoors and in animal sheds, between 6:00 PM and 6:00 AM, in 1996 and 1997. The sand fly behaved as an annual species, with a high frequency year-round, while it was most abundant during the rainy season (57.2%) as compared to the dry season (42.8%). The highest frequencies during the rainy season occurred in January and April and in the dry season in July and November. The species was found all night long, mainly between 6:00 PM and 10:00 PM in animal sheds and between 8:00 PM and 2:00 AM indoors.

Structure refinement of the aldehyde oxidoreductase from Desulfovibrio gigas (MOP) at 1.28 Å.

The sulfate-reducing bacterium aldehyde oxidoreductase from Desulfovibrio gigas (MOP) is a member of the xanthine oxidase family of enzymes. It has 907 residues on a single polypeptide chain, a molybdopterin cytosine dinucleotide (MCD) cofactor and two [2Fe-2S] iron-sulfur clusters. Synchrotron data to almost atomic resolution were collected for improved cryo-cooled crystals of this enzyme in the oxidized form. The cell constants of a=b=141.78 Å and c=160.87 Å are about 2% shorter than those of room temperature data, yielding 233,755 unique reflections in space group P6122, at 1.28 Å resolution. Throughout the entire refinement the full gradient least-squares method was used, leading to a final R factor of 14.5 and R free factor of 19.3 (4σ cut-off) with "riding" H-atoms at their calculated positions. The model contains 8146 non-hydrogen atoms described by anisotropic displacement parameters with an observations/parameters ratio of 4.4. It includes alternate conformations for 17 amino acid residues. At 1.28 Å resolution, three Cl(-) and two Mg(2+) ions from the crystallization solution were clearly identified. With the exception of one Cl(-) which is buried and 8 Å distant from the Mo atom, the other ions are close to the molecular surface and may contribute to crystal packing. The overall structure has not changed in comparison to the lower resolution model apart from local corrections that included some loop adjustments and alternate side-chain conformations. Based on the estimated errors of bond distances obtained by blocked least-squares matrix inversion, a more detailed analysis of the three redox centres was possible. For the MCD cofactor, the resulting geometric parameters confirmed its reduction state as a tetrahydropterin. At the Mo centre, estimated corrections calculated for the Fourier ripples artefact are very small when compared to the experimental associated errors, supporting the suggestion that the fifth ligand is a water molecule rather than a hydroxide. Concerning the two iron-sulfur centres, asymmetry in the Fe-S distances as well as differences in the pattern of NH(...)S hydrogen-bonding interactions was observed, which influences the electron distribution upon reduction and causes non-equivalence of the individual Fe atoms in each cluster.

[Anopheles species in the municipality of Pinheiro (Maranhão), endemic area of malaria]. / Espécies de Anopheles no município de Pinheiro (Maranhão), área endêmica de malária.

The Anophelae species of the municipal district of Pinheiro, Maranhão State, Brazil, were studied, considering their variety, relative abundance, seasonal fluctuation, preference by the peri and intra domiciles as well as the hours of hematophagism. The females were captured using human bait, on a monthly basis from May/1998 to April/1999, from 6 p.m. to 6 a.m. A total of 1,321 specimens of 10 species were captured, all belonging to the subgenus Nyssorhynchus. The most frequent species were A. argyritarsis (62%), A. darlingi (21.7%), A. albitarsis (4.5%), A. galvaoi (4.0%), A. triannulatus (3.1%) and A. evansae (2.8%). The species A. nuneztovari, A. braziliensis, A. rondoni and A. strodei together represented 1.9%. The anophelines occurred all year round, with no significant difference in the number of specimens captured between the rainy (51.7%) and dry season (48.3%). The frequency of the females in the peridomicile was significantly higher (p < 0.01) (82%), than in the intradomicile (18%), preferring to suck blood at dusk and in the first hours of the night.

[Phlebotominae (Diptera: Psychodidae) of Lagoas, a city of Buriticupu, Amazonia of Maranhão. I. The richness and relative abundance of the species in an area of recent colonization]. / Phlebotominae (Diptera: Psychodidae) de Lagoas, município de Buriticupu, Amazônia Maranhense. I--Riqueza e abundância relativa das espécies em área de colonização recente.

In this study the diversity of the species and relative abundance of the sand flies in the Amazonian community of Lagoas, in Buriticupu, Maranhão State, was determined. The study consisted of adult sandflies captured with CD light-traps, Shannon-trap and manual aspiration tube, between 18 PM and 6 AM, once a month, from December/95 to January/97, in a forest fragment and in the domestic environment (peri and intra). In all, 9,393 specimens were captured (4,302 males and 5,140 females) distributed among 38 species (1 Brumptomyia and 37 Lutzomyia). The diversity and abundance of species was higher in the forest, followed by the peri and intra. The predominance in the wild ambient is a consequence of the potentialities found in the remaining fragments of the forest which have survived the lumber yard exploitation and agricultural activities. In the forest environment Lutzomyia whitmani (64.9%), L. migonei (27%) and L. serrana (3.6%) were the most frequent species. In the peri and intra domicile L. evandroi predominated (55.4% and 97.9%). The species, L. whitmani (33.4%) and L. migonei (6.4%), were important in the peri domicile. The peridomestic habit of 7.7% of the sand flies showed the greatest epidemiologic importance, due to the existence of patients with leishmaniasis ulcers, who believe they were infected near their habitations.

[Sandflies (Diptera, psychodidae) in a secondary forest area in the Paco do Lumiar city, Maranhao, Brazil: a leishmaniasis transmission area]. / Flebotomíneos (Diptera, Psychodidade) de capoeira do Município do Paço do Lumiar, Estado do Maranhão, Brasil. Area de transmissão de leishmaniose.

This paper analyzes the wealth of species, relative abundance, seasonal fluctuation, and nocturnal activity of sandflies. The field survey was conducted in a "capoeira" (secondary forest) area in the county of Paço do Lumiar, Maranhão, where cutaneous and transmission of visceral leishmaniasis frequently occurs. Sandflies were captured by CDC-type light traps from 6:00 PM to 6:00 AM, once a month, from March 1997 to February 1998. A total of 489 specimens were collected (251 males and 238 females), distributed among 10 species: Lutzomyia antunesi (45.19%), Lutzomyia whitmani (29.4%), Lutzomyia longipalpis (7.56%), Lutzomyia sordelli (6.34%), Lutzomyia flaviscutellata (4.5%), Brumptomyia avellari (4.09%), Lutzomyia evandroi (1.85%), Lutzomyia umbratilis (0.61%), Lutzomyia corossoniensis (0.41%), and Lutzomyia trispinosa (0.41%). The sandflies were present year round, with higher abundance during the rainy season. They were present in all intervals studied, with the highest frequency between 12:00 PM and 1:00 AM (31%).