Top PDF Survey of sand flies (Diptera: Psychodidae) in an environmentally protected area in Brazil.

Survey of sand flies (Diptera: Psychodidae) in an environmentally protected area in Brazil.

Survey of sand flies (Diptera: Psychodidae) in an environmentally protected area in Brazil.

longipalpis, and cases of human and canine VL in such tourist areas. The Parque Estadual do Sumidouro is an environmentally protected area located in the Brazilian Cerrado biome and in an important area endemic for leishmaniasis in the state of Minas Gerais. The pur- pose of this study was to monitor the sand fly fauna in areas of tourist activity in the park. Sampling was performed every month, from September 2011 to August 2013, using CDC light traps at six sites of differing environmental characteristics. Sampled specimens were identified following Galati (2003), and females were submitted to molecular techniques for the detection and identification of Leishmania DNA. A total of 4,675 sand fly specimens of 25 species belonging to nine genera were collected. The most abundant species were Micropygomyia quinquefer, Lutzomyia renei and Pintomyia pessoai, although only Pi. pes- soai is implicated in the transmission of Leishmania braziliensis. The species accumulation curve reached saturation on the 16th sampling event. Species richness, diversity and even- ness differed among the sampled areas. The seasonal curve was not determined by a sin- gle unique species, and no single species was the most abundant in all environments sampled. The main vector of Leishmania (Leishmania) infantum, Lutzomyia longipalpis, accounted for only 5.35% of the specimens collected. Proven or suspected vectors of Leish- mania (Viannia) braziliensis were recorded, and one female of the cortellezzii complex tested positive for Le. braziliensis DNA. Even with a low infection rate (0.62%), these data indicate the circulation of the parasite and reinforce the need for entomological and epidemiological surveillance in the park and its surroundings.
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Sand Flies (Diptera: Psychodidae) in a Cerrado Area of the Maranhão State, Brazil

Sand Flies (Diptera: Psychodidae) in a Cerrado Area of the Maranhão State, Brazil

The seasonal profi le of phlebotomine sand fl ies depicted herein corroborates other inventories carried out in Maranhão, where a great amount of individuals have constantly been trapped in the rainy season. The annual occurrence of Lu. longipalpis suggests that the visceral leishmaniasis transmission is not dependent on the rainy period, even though an increased sand fl y population has been collected during the highest pluviometric index season, as previously reported (Rebêlo et al 1999b, Carvalho et al 2000, Araújo et al 2000). Lutzomyia whitmani occurred almost all year round and mostly in the rainy season, as already observed in cerrado region (Rebêlo et al 1999b) and in the Amazonian areas of Maranhão (Rebêlo et al 2001).
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Bionomics of phlebotomine sand flies (Diptera: Psychodidae) in the province of Al-Baha, Saudi Arabia

Bionomics of phlebotomine sand flies (Diptera: Psychodidae) in the province of Al-Baha, Saudi Arabia

The geographic location of Al-Baha contributes to the potential risk for CL in Saudi Arabia; it is also pos- sible to contract infections from neighboring countries there. This study is a report of the results of an entomo- logical survey of sand flies in Al-Baha province, Saudi Arabia. The goal of this report was to identify the sand fly vectors associated with CL-endemic areas of Al- Baha province. Efforts were also made to identify the bionomics of the sand flies in the area. P. bergeroti, P. sergenti, P. arabicus, S. tiberiadis, P. papatasi and S. an- tennata were the most abundant species identified in the current study. The identified species were also reported in many parts of the kingdom of Saudi Arabia, such as Riyadh (Morsy & al Seghayer 1992), Asir (Ibrahim & Abdoon 2005), Qasim (el Sibae et al. 1993) and Al- Hassa (Al-Gindan et al. 1984). Dominance of one or two species of sand flies is a feature of many areas of Saudi Arabia (Ibrahim & Abdoon 2005, El-Badry et al. 2008) and of some parts of the Middle East, including Egypt (El Sawaf et al. 1987, Fahmy et al. 2009, Shehata et al. 2009), Iraq (Seccombe et al. 1993, Coleman et al. 2007), Palestine (Sawalha et al. 2003) and Jordan (Kamhawi et al. 1991). The collected species reported here include the most important vectors of CL in the Middle East, which contribute to the persistence of the CL transmission cycle in Saudi Arabia. Here, P. papatasi was relatively less abundant than previously reported (El-Badry et al. 2008), which is likely due to the difference in commu- nity structure and nature of habitats sampled, i.e., mostly
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Entomological survey of phlebotomine sand flies (Diptera: Psychodidae) in a focus of visceral leishmaniasis in central Iran

Entomological survey of phlebotomine sand flies (Diptera: Psychodidae) in a focus of visceral leishmaniasis in central Iran

during 1953–58. This area entered the consolidation phase after 1958, and indoor residual spraying was stopped, but insecticides were used in agriculture as well as domestic sprays in human dwellings. Considering the importance of the vector(s) in the transmission of the VL cycle, an entomological sur- vey was carried out to study the sand fly fauna, spe- cies composition, population density, monthly preva- lence of sand flies, number of generations and leish- manial infection rate of sand flies. The susceptibility level of vectors to DDT in the Shahreza area of Iran was also conducted. There was no classical study performed on the vectors of VL in this region and the present study provides the basic information.
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Sand Flies (Diptera: Psychodidae) in the Urban Area of the Municipality of Cianorte, Paraná State, Brazil

Sand Flies (Diptera: Psychodidae) in the Urban Area of the Municipality of Cianorte, Paraná State, Brazil

There is an area of modified native forest in the municipality known as the Parque Municipal Cinturão Verde, which is a remnant of a seasonal deciduous sub-montane forest. This forest is a permanent reserve, and has a border of approximately 7 km with the urban perimeter, with a pedestrian path running along it. The park has abundant fauna, composed of amphibians, arachnids, birds, insects, reptiles, and some mammals, in particular bush dogs, coatis, bats, armadillos, skunks, mouse-possums, capuchins, opossums, pacas, agoutis, wild mice, squirrels, hedgehogs and anteaters (Prefeitura do Município de Cianorte 2006). In the State of Paraná, ACL was confi rmed early in the
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The sandfly fauna (Diptera: Psychodidae: Phlebotominae) of the Parque Estadual da Serra da Tiririca, Rio de Janeiro, Brazil

The sandfly fauna (Diptera: Psychodidae: Phlebotominae) of the Parque Estadual da Serra da Tiririca, Rio de Janeiro, Brazil

Cutaneous leishmaniasis (CL) in the state of Rio de Janeiro is sporadic and can be characterised as a peridomes- tic transmission that occurs in modified natural environments. The aim of this work was to study the fauna and eco- logical characteristics of sandflies in an environmentally protected area (the State Park of Serra da Tiririca) within the remnants of the Atlantic Forest in the municipalities of Niterói and Maricá and their possible relationship with leishmaniasis. Captures were performed using light traps during the night once a month for one year in both sylvatic environments and areas surrounding homes near the park. A total of 1,037 sandflies were captured, belonging to nine genera and 12 species: Evandromyia tupynambai (34.1%), Migonemyia migonei (20.6%), Brumptomyia cunhai (13.8%), Micropygomyia schreiberi (9.7%), Psathyromyia lanei (6.5%), Brumptomyia nitzulescui (5.7%), Evandro- myia edwardsi (5.4%), Nyssomyia intermedia (2.8%), Evandromyia cortelezzii (0.6%), Pintomyia bianchigalatiae (0.5%), Lutzomyia longipalpis (0.2%) and Sciopemyia microps (0.1%). Both Mg. migonei and Ny. intermedia may be acting as vectors of CL in this area.
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Phlebotomines in an area endemic for American cutaneous leishmaniasis in northeastern coast of Brazil

Phlebotomines in an area endemic for American cutaneous leishmaniasis in northeastern coast of Brazil

Maroli M, Feliciangeli MD, Bichaud L, Charrel RN, Gradoni L. Phlebotomine sandflies and the spreading of leishmaniases and other diseases of public health concern. Med Vet Entomol 2013; 27(2): 123-147. PMid:22924419. http://dx.doi.org/10.1111/j.1365-2915.2012.01034.x. Michalsky EM, Fortes-Dias CL, Pimenta PFP, Secundino NFC, Dias ES. Assessment of PCR in the detection of Leishmania spp in experimentally infected individual phlebotomine sandflies (Diptera: Psychodidae: Phlebotominae). Rev Inst Med Trop Sao Paulo 2002; 44(5): 255-259. PMid:12436164. http://dx.doi.org/10.1590/S0036-46652002000500004. Miranda DEO, Sales KGS, Faustino MAG, Alves LC, Brandão-Filho SP, Dantas-Torres F, et al. Ecology of sand flies in a low-density residential rural area with mixed forest/agricultural exploitation, in north-eastern Brazil. Acta Trop 2015; 146: 89-94. PMid:25792416. http://dx.doi. org/10.1016/j.actatropica.2015.03.011.
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Density of sand flies (diptera: psychodidae) in domestic and wild animal shelters in an area of visceral leishmaniasis in the state of Rio Grande do Norte, Brazil

Density of sand flies (diptera: psychodidae) in domestic and wild animal shelters in an area of visceral leishmaniasis in the state of Rio Grande do Norte, Brazil

The dinamic involved in sand fly aggregation and animal host is not completely understood. Our findings raises two possible explanations for the aggregation. Animals seem to attract sand flies to the peridomicialy environment as shown by the decrease in sand flies density after removal of do- mestic animals, rodents and armadillos without any insecticide spraying. Furthermore, it is possible that male Lu. longipalpis utilize hot blood animals (horses) as lekking sites as a result of the species adaptation to more opened places, where Lu. longipalpis can be frequently found. The animal body heat can be important for the spread of phero- mone and attraction of sand flies. Horses with the body size and decrease of activity in the evening could be contributing to the perfection of Lu. longipalpis strategy for mating. Finally, males and females aggregate close to the host where they copulate followed by female feeding on the host and/or posture in the more humid and rich organic debris. Despite the availability of behavioral stud- ies on Lu. longipalpis and the attempts to under- stand the participation of semiochemicals as me- diators of the presence of vectors in the human environment, the dynamics of sand fly aggrega- tion in shelters for domestic and wild animals needs further elucidation. In addition, the results obtained in several studies on zoophilic and anthropophilic behavior in a natural environment are conflicting. Thus, an understanding of the relations between sand flies and domestic and wild animals reared by man coupled with the understanding of genetic and behavior differences among the vector popu- lation from distinct geographic areas may contrib- ute to improve measures for the control of leish- maniasis in rural areas of the Northeast region, where drought and scarcity of food affect customs and expose man to risks of developing diseases such as visceral and cutaneous leishmaniasis.
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Density of Sand Flies (Diptera: Psychodidae) in Domestic and Wild Animal Shelters in an Area of Visceral Leishmaniasis in the State of Rio Grande do Norte, Brazil

Density of Sand Flies (Diptera: Psychodidae) in Domestic and Wild Animal Shelters in an Area of Visceral Leishmaniasis in the State of Rio Grande do Norte, Brazil

The dinamic involved in sand fly aggregation and animal host is not completely understood. Our findings raises two possible explanations for the aggregation. Animals seem to attract sand flies to the peridomicialy environment as shown by the decrease in sand flies density after removal of do- mestic animals, rodents and armadillos without any insecticide spraying. Furthermore, it is possible that male Lu. longipalpis utilize hot blood animals (horses) as lekking sites as a result of the species adaptation to more opened places, where Lu. longipalpis can be frequently found. The animal body heat can be important for the spread of phero- mone and attraction of sand flies. Horses with the body size and decrease of activity in the evening could be contributing to the perfection of Lu. longipalpis strategy for mating. Finally, males and females aggregate close to the host where they copulate followed by female feeding on the host and/or posture in the more humid and rich organic debris. Despite the availability of behavioral stud- ies on Lu. longipalpis and the attempts to under- stand the participation of semiochemicals as me- diators of the presence of vectors in the human environment, the dynamics of sand fly aggrega- tion in shelters for domestic and wild animals needs further elucidation. In addition, the results obtained in several studies on zoophilic and anthropophilic behavior in a natural environment are conflicting. Thus, an understanding of the relations between sand flies and domestic and wild animals reared by man coupled with the understanding of genetic and behavior differences among the vector popu- lation from distinct geographic areas may contrib- ute to improve measures for the control of leish- maniasis in rural areas of the Northeast region, where drought and scarcity of food affect customs and expose man to risks of developing diseases such as visceral and cutaneous leishmaniasis.
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Phlebotomine sand flies (Diptera: Psychodidae) in the municipality of Várzea Grande: an area of transmission of visceral leishmaniasis in the state of Mato Grosso, Brazil

Phlebotomine sand flies (Diptera: Psychodidae) in the municipality of Várzea Grande: an area of transmission of visceral leishmaniasis in the state of Mato Grosso, Brazil

The municipality of Várzea Grande (VG) (15º 32’ 30" S 56º 17’ 18" W) is known as the industrial town of MT, Brazil. With a population of 214,842 inhabitants (IBGE 2000 apud Ferreira 2001), the town, together with the state capital Cuiabá, comprises the so called Urban Con- glomerate of Cuiabá or Metropolitan Region of Cuiabá. VG is at 185m of altitude and has a territorial extension of 949.53km 2 . It is in the central-south zone of the Mesoregion of MT, microregion of Cuiabá, with a subhumid tropical climate and annual rainfall of 1,750 mm. The rainy period runs between September and April with greater in- tensity from January to March. The yearly average tempera- ture is 24ºC, reaching up to 34.1ºC, and absolute maximum temperatures may be over 42ºC. The minimum average temperature in July, the coldest month, is 16.7ºC. The geomorphologic figure of the municipality is mostly represented by Planalto da Casca and Depressão Cuiabana. Low amplitudes predominate in the region with altitudes ranging from 146 to 250 m in the city area. The predominant vegetation is the savannah, from its bushy form to the densest forests along water streams (Piaia 2003). VG has reported both canine and human VL cases since 1998. The transmission area ranges from the dis- tricts of Eldorado and São Matheus to Parque Sabiá (Fig. 1). The area under study, including dwellings, was cho- sen based on previous entomological surveys (Hueb et al. 2000, Ribeiro & Missawa 2002), studies on VL inci- dence and prevalence rates in man, according to which the municipality was regarded as an area of intense VL transmission in 2003. In the study area, the residents have low socio-economical conditions and dwellings show no basic sanitation, regular garbage collection and electric current. A survey in the area revealed that dogs and chickens were present in 100% of house surround- ings, followed by other domestic animals such as ducks, turkeys, pigs, horses, cows, cats, and due to the pres- ence of sites of garbage concentration named “lixões”
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Seasonality of sand flies (Diptera: Psychodidae) and Leishmania DNA detection in vector species in an area with endemic visceral leishmaniasis

Seasonality of sand flies (Diptera: Psychodidae) and Leishmania DNA detection in vector species in an area with endemic visceral leishmaniasis

Sand fly collection - Procedures for collecting sand flies were approved by the Ministério do Meio Ambiente do Brasil (Ministry of Environment of Brazil) - (SISBIO license number 15,237). For the analysis of sand fly pop- ulations, 18 light traps were arranged uniformly within the SD; one trap was centrally located in each health cen- tre coverage area. In two sites, Serra Verde (VNSV) and Venda Nova (VNVN), two traps were used because the geographical areas of these sites did not enable the lo- cation of a single central point. A simple environmental characterisation was performed at each collection point by recording environmental characteristics related to phlebotomine occurrence at a locality. These characteris- tics included the presence of vegetation and the presence of water, both of which relate to breeding sites and the supportive environment for phlebotomine. The presence of livestock, the presence of a hen house, and the pres- ence of a dog kennel are all related to providing a source of food for females. The traps when possible were placed inside the shelters of the animals, or as close as possible to the environments of interest, a few metres away, at most about 10 metres. The environmental characteristics of the collection point are briefly described in (Table I).
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Alfredo CR Azevedo, Maurício L Vilela, Nataly A Souza, Claudia A Andrade- Coelho, André F Barbosa, Antônio LS Firmo, Elizabeth F Rangel

Alfredo CR Azevedo, Maurício L Vilela, Nataly A Souza, Claudia A Andrade- Coelho, André F Barbosa, Antônio LS Firmo, Elizabeth F Rangel

Queiroz RG, Vasconcelos I, Vasconcelos AW, Souza ARN, David J 1991. New world phlebotomine sand flies as hosts of Leishmania (V.) braziliensis in an endemic area of cutaneous leishmaniasis in Ceará State, Northeast Brazil. First International Sym- posium on Phlebotomine Sandlies, Rome, p. 87. Rangel EF 1993. Estudo comparativo de três populações de Lutzomyia (Nyssomyia) whitmani (Antunes & Coutinho, 1939) (Diptera, Psychodidae, Phlebotominae). Thesis, Instituto de Ciências Biológicas, Universidade de São Paulo, 90 pp. Rangel EF, Azevedo ACR, Andrade CA, Souza NA,
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Rev. Soc. Bras. Med. Trop.  vol.40 número1

Rev. Soc. Bras. Med. Trop. vol.40 número1

Among the entomological research carried out in the State of Mato Grosso, Aguiar and Medeiros 1 presented a list of sand flies; De Luca et al 5 studied the distribution of sand flies in Alta Floresta, in the northern region of the state; Costa et al 4 and Rodrigues et al 13 developed entomological domestication studies in the mid-northern and mid-southern regions; Ribeiro and Missawa 12 described the spatial distribution of sand flies in the state, with emphasis on the species related to leishmaniasis transmission; Azevedo et al 2 identified 26 sand fly species in Peixoto de Azevedo, in the northern region of the state; Moura 9 developed an epidemiological survey on canine leishmaniasis in Cuiabá; Ribeiro et al 11 carried out a study on leishmaniasis vectors in the area influenced by the Manso power station; Ribeiro and Missawa 11 12 investigated the occurrence of Lutzomyia longipalpis in the city of Várzea Grande; and Cipa 3 dealt with the state as a whole.
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Diversity of myxomycetes in an environmentally protected area of Atlantic Forest in northeastern Brazil

Diversity of myxomycetes in an environmentally protected area of Atlantic Forest in northeastern Brazil

Rostaf. and Tubifera microsperma were rare and found only in the rainy season. Cribraria mirabilis (Rostaf.) Massee and Licea biforis were rare and found in September (beginning of the dry season). Clastoderma debaryanum, Dictydiaetha- lium plumbeum (Schumach.) Rostaf. and Fuligo septica (L.) F.H. Wigg. were rare and occurred between October and December. Although constant on the Flores Trail (50%), Cribraria microcarpa (Schrad.) Pers. (found in the rainy season and beginning of the dry season), Physarum viride and Stemonitis axifera (Bull.) T. Macbr. were not recorded for the other two trails (Tab. 2). Collaria arcyrionema (Rostaf.) Nann.-Bremek. ex Lado was also constant on the Flores Trail, but was accidental on the Boa Vista Trail and absent from the Cumbe Trail. Physarella oblonga (Berk. & M.A. Curtis) Morgan was accidental and scarce on the Boa Vista and Flores Trails (present only at the beginning of the dry season) and absent from the Cumbe Trail. Ogata et al. (1996) stated that, despite being cosmopolitan, P. oblonga is always scarce, which is corroborated by the present study. Physarum stellatum and Cribraria cancellata were constant on the Flores Trail, although accidental on the Cumbe Trail and absent from the Boa Vista Trail. Physarum penetrale Rex was accidental on the Flores and Cumbe Trails, with no records for the Boa Vista Trail. Those two species were more abundant in September and October (beginning of the dry season). Cribraria violacea Rex, Didymium nigripes (Link) Fr., Physarum nucleatum Rex, Stemonitis splendens and S. smithii T. Macbr. were found in September, October and De- cember, revealing that they sporulate either at the beginning or middle of the dry season. Common only to the Cumbe and Boa Vista Trails, these species were accidental in the myxobiota studied; P. nucleatum, S. smithii and S. splendens can be classified as accessory on the Cumbe Trail (Tab. 2). The lignicolous group was very well represented in the PFF in terms of richness (with 40 species from 22 genera, ac- counting for 83.3% of the species identified) and abundance,
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ICHTHYOFAUNA DIVERSITY IN A PROTECTED AREA IN THE STATE OF SÃO PAULO, SOUTHEASTERN BRAZIL

ICHTHYOFAUNA DIVERSITY IN A PROTECTED AREA IN THE STATE OF SÃO PAULO, SOUTHEASTERN BRAZIL

The study site is located in an environmentally protected area known as an “APA” in São Pedro and Analândia, State of São Paulo, southeastern Brazil, whose watercourses are under strong anthropogenic pressure. Two basins were studied (sub-basin of the Corumbataí River and basin of the Jacaré-pepira River) with the purpose of characterizing the ichthyofauna of various streams, comparing fish diversity among assemblages. The Passa-cinco River showed the highest diversity (H’), and the Jaccard and Morisita-Horn indices showed low similarity among sites and between the basins. Diversity was correlated with the number of available habitats and with the environmental conditions.
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Cad. Saúde Pública  vol.27 número11

Cad. Saúde Pública vol.27 número11

Montes Claros in Minas Gerais State, Brazil, was considered an intense transmission area for vis- ceral leishmaniasis. This study evaluated sand fly fauna after insecticide application. Captures were performed in 10 districts from September 2005 to August 2006 with CDC light traps inside and out- side each residence. Cypermethrin was sprayed in two cycles during November/2005 and May/2006. The 636 specimens collected, belonging to 10 spe- cies, were predominantly Lutzomyia longipalpis (79%), and most frequently males (70%). The highest percentage of specimens were captured in areas surrounding domiciles (85.8%). The main species were observed to be sensitive to treatment with the insecticide. The results showed a reduc- tion in the number of sand flies collected after use of cypermethrin in homes and annexes, and with residual effect lasting from two to four months.
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A Cross-Sectional Survey of Knowledge, Attitude and Practices Related to Cutaneous Leishmaniasis and Sand Flies in Punjab, Pakistan.

A Cross-Sectional Survey of Knowledge, Attitude and Practices Related to Cutaneous Leishmaniasis and Sand Flies in Punjab, Pakistan.

Cutaneous leishmaniasis is a sand fly-borne neglected tropical disease caused by protozoan parasites in the genus Leishmania. It is commonly known as post-kala-azar dermal leishmai- niasis in Hindi and lahori phora or sehrai phora in Urdu. The disease is commonly character- ized with skin sores or skin infection symptoms. About one million cases of cutaneous leishmaniasis occur annually worldwide with the hotspots in Afghanistan, Algeria, Iran, Paki- stan, Peru, Brazil, Saudi Arabia, Colombia and Tunisia [1]. In Pakistan, it is one of the major and rapidly increasing public health issues, especially alongside regions bordering the neigh- boring Afghanistan and cities that have had the maximum influx of refugees from Afghanistan. About 5000 cases of cutaneous leishmaniasis had been reported during 2002, in the Khyber Pakhtun Khwa province of Pakistan [2]. This disease is highly endemic in different parts of the country, including the Punjab province, but recently it seems to become an epidemic [3] and hence disease alerts have been generated in the country through print media [4].
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Phlebotomine Sand Flies in Porteirinha, an Area of American Visceral Leishmaniasis Transmission in the State of Minas Gerais, Brazil

Phlebotomine Sand Flies in Porteirinha, an Area of American Visceral Leishmaniasis Transmission in the State of Minas Gerais, Brazil

A study of the phlebotomine sand fly fauna was carried out in an endemic area of American visceral leishmania- sis (AVL) in the municipality of Porteirinha, in the Brazilian state of Minas Gerais. Captures were performed with CDC light traps in 7 districts, 5 days per month, during 2 consecutive years (January 2000 to December 2001). A total of 3240 sand flies were captured and identified. Sixteen species were found, among which 15 belonged to the genus Lutzomyia and one to the genus Brumptomyia. Lutzomyia longipalpis, a proven vector of AVL, was the predomi- nant species (71.85%) throughout the time period. The interference of climatic factors (temperature, humidity, and rainfall) over the populational dynamics of the sand flies was determined. Statistical analysis of the data showed a significant correlation among the number of phlebotomine sand flies collected, rainfall, and humidity, whereas the effect of temperature was negligible, in that particular region. The amount of collected phlebotomine, the number of human cases, and the prevalence of canine AVL in the districts of Porteirinha are discussed.
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Investigating The Use Of Mobile Computing In Zimbabwe Polytechnics Case Of A Polytechnic In Zimbabwe

Investigating The Use Of Mobile Computing In Zimbabwe Polytechnics Case Of A Polytechnic In Zimbabwe

). This shows that there has been upgrading and improvement in mobile computing device characteristics since Zimm erman’s research up to now. Dahlstrom (2012), a senior research analyst at EDUCAUSE, in his article titled ―Executive Summary: Student Mobile Computing Practices—lessons learned from Qatar‖ says that students find Mobile technology convenient and engaging and institutions need to invest more in mobile device use and support. In Qatar the Education City conducted a survey jointly with ECAR (Every Child a Reader) of United Kingdom (UK) on student mobile computing technology and the results were not only relevant to their student’s experiences but also speaks to the global revolution of mobile technology in the academic environment. The findings revealed that, for students, technology plays an important role in productivity and communication, students want technology integrated into their academic experience and students want to better utilise mobile technology in their learning environments doing such things as creating content for course assignments, accessing course related material and pushing the limits of mobile device productivity. Kim et al (2006) identified the benefits of using mobile wireless phones as freedom of location and time, increasing speed in teaching and learning, enabling one-to-one learning based on individual educational histories or test results, better communication opportunities and better collaboration in group discussions. They also identified the specific benefits of using Personal Data Assistants in m-learning as mobility, information management capacity, beaming capability, ability to work in many places and replacement of pen and paper. A UK essays website argued that the major challenge for educators and trainers is how to develop learning materials for delivery on
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Human Capital and the Recent Fall of Earnings Inequality in Brazil

Human Capital and the Recent Fall of Earnings Inequality in Brazil

where is a set of linear restrictions that transforms the unrestricted model (1) on restricted model (2). 8 In our case, the restriction implies that the age, trend and (orthogonal) time dummies are sufficient to explain the behavior of each estimated statistic order across cells and over time. Imposing the restrictions means estimating weighted least squares regressions on the grouped data, for each quantile and education group separately. This procedure will give us consistent estimates of . Under the null that the restrictions are valid, the minimized value follows a chi-square distribution with degrees of freedom equal to the number of restrictions. In order to construct the test statistics, we only have to sum up the weighted squared residuals, that is, the estimated percentiles minus the predicted values minus the orthogonal time dummies.
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