Cephalobellus lobulata n. sp. (Oxyurida:Thelastomatidae) a parasite of Neocurtilla claraziana Saussure (Orthoptera: Gryllotalpidae) from Argentina

Cephalobellus lobulata n. sp. (Oxyurida: Thelastomatidae) a parasite of the mole cricket Neocurtilla claraziana Saussure (Orthoptera: Gryllotalpidae) found in Argentina is described and illustrated. It is characterized by a short buccal cavity armed with three teeth, a striated cuticle with the first annule wide with four lobes and the second annule divided in twelve lobes. The male have three pairs of preanal papillae and two pairs of postanal papillae.

Effects of flooding and temperature on Aedes albifasciatus development time and larval density in two rain pools at Buenos Aires University City

Aedes albifasciatus is a floodwater mosquito that breeds in temporary waters. This semi-domestic species, widely distributed in Argentina, is a competent vector of the western equine encephalitis. The present study was carried out in two rain pools of the city of Buenos Aires, from April 1998 through March 1999. Samples were taken twice a week during the cold season and daily during the warmer months, starting from October. Immature mosquitoes were collected with a dipper, being the number of dippers proportional to the flooded area. The estimated rainfall thresholds to initiate cohorts of Ae. albifasciatus were: 16-17 mm in the fall-winter period, 25 mm in the spring, and 30 mm in the summer. The development time of the different cohorts and the mean air temperature of their respective periods were estimated in all seasons, ranging from six days (at 24ºC) to 32 days (at 13ºC). The equation that best expresses the relationship between development time and mean air temperature is dt =166,27.e-0,1435.T (R²=0,92). Significantly shorter development times were recorded for larvae of the first three stages as compared to the fourth larval stage and pupae.

The first confirmed case of Diphyllobothrium latum in Brazil

Diphyllobothriasis is an infection of the small intestine by the broad tapeworm Diphyllobothrium sp. The associated symptomatology is nonspecific, but megaloblastic anemia is a well-described complication. Although the infection is common in temperate regions, descriptions in South America have so far been limited to Chile, Peru, and a few cases in Argentina. This paper presents the first confirmed Brazilian case of diphyllobothriasis. A 29-years-old woman living in Salvador (state of Bahia) apparently acquired the infection from eating sushi. The diagnosis was based on fecal examination that revealed a large quantity of operculated eggs. A single dose of praziquantel (600 mg) was sufficient to cure the infection.

Recognition of the epidemiological significance of Neisseria meningitidis capsular serogroup W135 in the Rio de Janeiro region, Brazil

Neisseria meningitidis retains its ability to cause endemic and hiperendemic disease in human population living in any environment, as well as localized outbreaks and massive epidemics in civilians and military personnel. In Rio de Janeiro it has been reported in the 1990s as prolonged outbreak of serogroup B and at least one epidemic of serogroup C was well defined, both demanding quick action by the Public Health authorities. We report here the emergence of serogroup W135 meningococcal disease causing endemic and case cluster in Rio de Janeiro during the first years of this new century.

Susceptibility of Triatoma infestans to deltamethrin in Rio Grande do Sul, Brazil

Strategies for controlling Chagas disease are based on spraying infested houses with pyrethroid insecticides. However, the intense use of these insecticides has promoted resistance of Triatoma infestans and, in Argentina, Bolivia and Southern Brazil, low levels of resistance have been reported. Due to the persistence of T. infestans in the state of Rio Grande do Sul (RS), we evaluated the occurrence of deltamethrin resistance in four strains from different municipalities in comparison to two susceptible strains from Brazil and one resistant strain from Bolivia. The results indicated the absence of resistance in T. infestansfrom RS.

G6PD deficiency in Latin America: systematic review on prevalence and variants

Plasmodium vivax radical cure requires the use of primaquine (PQ), a drug that induces haemolysis in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals, which further hampers malaria control efforts. The aim of this work was to study the G6PDd prevalence and variants in Latin America (LA) and the Caribbean region. A systematic search of the published literature was undertaken in August 2013. Bibliographies of manuscripts were also searched and additional references were identified. Low prevalence rates of G6PDd were documented in Argentina, Bolivia, Mexico, Peru and Uruguay, but studies from Curaçao, Ecuador, Jamaica, Saint Lucia, Suriname and Trinidad, as well as some surveys carried out in areas of Brazil, Colombia and Cuba, have shown a high prevalence (> 10%) of G6PDd. The G6PD A-202A mutation was the variant most broadly distributed across LA and was identified in 81.1% of the deficient individuals surveyed. G6PDd is a frequent phenomenon in LA, although certain Amerindian populations may not be affected, suggesting that PQ could be safely used in these specific populations. Population-wide use of PQ as part of malaria elimination strategies in LA cannot be supported unless a rapid, accurate and field-deployable G6PDd diagnostic test is made available.

Is imidacloprid an effective alternative for controlling pyrethroid-resistant populations of Triatoma infestans (Hemiptera: Reduviidae) in the Gran Chaco ecoregion?

The prevention of Chagas disease is based primarily on the chemical control of Triatoma infestans (Klug) using pyrethroid insecticides. However, high resistance levels, correlated with control failures, have been detected in Argentina and Bolivia. A previous study at our laboratory found that imidacloprid could serve as an alternative to pyrethroid insecticides. We studied the delayed toxicity of imidacloprid and the influence of the blood feeding condition of the insect on the toxicity of this insecticide; we also studied the effectiveness of various commercial imidacloprid formulations against a pyrethroid-resistant T. infestans population from the Gran Chaco ecoregion. Variations in the toxic effects of imidacloprid were not observed up to 72 h after exposure and were not found to depend on the blood feeding condition of susceptible and resistant individuals. Of the three different studied formulations of imidacloprid on glass and filter paper, only the spot-on formulation was effective. This formulation was applied to pigeons at doses of 1, 5, 20 and 40 mg/bird. The nymphs that fed on pigeons treated with 20 mg or 40 mg of the formulation showed a higher mortality rate than the control group one day and seven days post-treatment (p < 0.01). A spot-on formulation of imidacloprid was effective against pyrethroid-resistant T. infestans populations at the laboratory level.

Congenital transmission of Trypanosoma cruzi in central Brazil. A study of 1,211 individuals born to infected mothers

Transmission of Trypanosoma cruziduring pregnancy is estimated to occur in less than 20% of infected mothers; however, the etiopathogenesis is not completely understood. The Centre for Studies on Chagas Disease provides confirmation of T. cruziinfection for individuals living in central Brazil. In this retrospective hospital-based study, all requests for diagnosis of T. cruziinfection in individuals less than 21 years old from 1994-2014 were searched. We end with 1,211 individuals and their respective infected mothers. Congenital transmission of infection was confirmed in 24 individuals (2%) in central Brazil, an area where the main T. cruzi lineage circulating in humans is TcII. This low prevalence of congenital Chagas disease is discussed in relation to recent findings in the south region of Brazil, where TcV is the main lineage and congenital transmission has a higher prevalence (approximately 5%), similar to frequencies reported in Argentina, Paraguay and Bolivia. This is the first report to show geographical differences in the rates of congenital transmission of T. cruziand the relationship between the prevalence of congenital transmission and the type of Tc prevalent in each region.

Networks in Argentine agriculture: a multiple-case study approach

Argentina is among the four largest producers of soybeans, sunflower, corn, and wheat, among other agricultural products. Institutional and policy changes during the 1990s fostered the development of Argentine agriculture and the introduction of innovative process and product technologies (no-till, agrochemicals, GMO, GPS) and new investments in modern, large-scale sunflower and soybean processing plants. In addition to technological changes, a "quiet revolution" occurred in the way agricultural production was carried out and organized: from self-production or ownership agriculture to a contract-based agriculture. The objective of this paper is to explore and describe the emergence of networks in the Argentine crop production sector. The paper presents and describes four cases that currently represent about 50% of total grain and oilseed production in Argentina: "informal hybrid form", "agricultural trust fund", "investor-oriented corporate structure", and "network of networks". In all cases, hybrid forms involve a group of actors linked by common objectives, mainly to gain scale, share resources, and improve the profitability of the business. Informal contracts seem to be the most common way of organizing the agriculture process, but using short-term contracts and sequential interfirm collaboration. Networks of networks involve long-term relationships and social development, and reciprocal interfirm collaboration. Agricultural trust fund and investor-oriented corporate structures have combined interfirm collaboration and medium-term relationships. These organizational forms are highly flexible and show a great capacity to adapt to challenges; they are competitive because they enjoy aligned incentives, flexibility, and adaptability.

New record of Pterotaenia fasciata (Wiedemann) (Diptera, Ulidiidae) in Brazil, a probably mechanical vector of enteric bacteria

Pterotaenia fasciata is commonly recorded in rural areas in Argentina, but during a Diptera survey study developed in a reservoir which retains storm water from polluted canals in an urban area of Taboão da Serra municipality, SP, Brazil, we could capture P. fasciata adults. Enteric bacteria Escherichia coli T. Escherich, 1885 and Proteus sp. were isolated from P. fasciata collected in traps inside the reservoir and around it. Fecal coliforms and E. coli were found in the water of the reservoir. These records suggest that a high abundance of this species at urban areas with inadequate sewage canals should reveal these muscoid dipterans as mechanical vectors of enteric bacteria.

Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae)

Dichroplus maculipennis and Borellia bruneri are two of the 18 grasshopper species of actual or potential economic relevance as pests in Argentina. The objective of this study was to estimate the sex ratios for adults and older nymphs of D. maculipennis and B. bruneri in the field, and analyze possible temporal variations. The study was conducted during seven seasons (2005-06 to 2011-12) in representative plant communities of the southern Pampas region. A total of 4536 individuals of D. maculipennis, and 6038 individuals of B. bruneri were collected. The sex ratio registered in older nymphs for D. maculipennis and B. bruneri did not deviate from a 1:1 ratio (p > 0.05), suggesting that these species have such a primary sex ratio. However, a significant bias in sex composition in adults of both species was observed (p < 0.05). The sex ratio in adults of D. maculipennis was different in five of the 18 sampling dates carried out. In three sampling dates it was biased toward males, while in the other two it was biased toward females. Taking into account the sex ratio by sampling season, significant differences were recorded in two seasons. In 2007-08 the sex ratio was biased toward males (1 F:2.26 M), while in 2008-09 it was biased toward females (1.35 F:1 M). The sex ratio in adults of B. bruneri was always biased toward males (p < 0.05). We conclude that results obtained in this study indicate that various factors like differential survival, dispersion, predation, among others, could have modified the primary sex ratio in these species.

Homicide-suicide cases in Switzerland and their impact on the Swiss Weapon Law.

Homicide followed by the suicide of the offender is a well-known phenomenon. In most cases, it takes place in the context of the so-called "family tragedies." A recent series of such family tragedies in Switzerland prompted an intensive debate in the media and the Swiss government concerning the Swiss Weapon Law, in particular the requirement to keep personal army weapons at home. The present study of Homicide-Suicide cases in Switzerland, thus focuses on the role played by guns, especially military weapons, in such crimes. We investigated retrospectively 75 cases of Homicide-Suicide, comprising 172 individuals and spanning a period of 23 years in western and central Switzerland. Our results show that if guns were used in 76% of the cases, army weapons were the cause of death in 25% of the total. In 28% of the deaths caused by a gunshot, the exact type of the gun and its origin could not be determined. Thus, the majority of Homicide-Suicide cases in Switzerland involve the use of guns. The exact percentage of cases were military weapons were involved could not be defined. In our opinion, a stricter weapons law, restricting access to firearms, would be a factor of prevention of Homicide- Suicide cases in Switzerland.

Childhood cancer mortality in America, Asia, and Oceania, 1970 through 2007.

BACKGROUND: Over the last 4 decades, childhood cancer mortality declined in most developed areas of the world. However, scant information is available from middle-income and developing countries. The authors analyzed and compared patterns in childhood cancer mortality in 24 developed and middle-income countries in America, Asia, and Oceania between 1970 and 2007. METHODS: Childhood age-standardized annual mortality rates were derived from the World Health Organization (WHO) database for all neoplasms, bone and kidney cancer, non-Hodgkin lymphoma (NHL), and leukemias. RESULTS: Since 1970, rates for all childhood cancers dropped from approximately 8 per 100,000 boys to 3 per 100,000 boys and from 6 per 100,000 girls to 2 per 100,000 girls in North America and Japan. Latin American countries registered rates of approximately 5 per 100,000 boys and 4 per 100,000 girls for 2005 through 2007, similar to the rates registered in more developed areas in the early 1980s. Similar patterns were observed for leukemias, for which the mortality rates were 0.81 per 100,000 boys and 0.55 per 100,000 girls in North America, 0.86 per 100,000 boys and 0.68 per 100,000 girls in Japan, and 1.98 per 100,000 boys and 1.65 per 100,000 girls in Latin America for 2005 through 2007. Bone cancer rates for 2005 through 2007 were approximately 2-fold higher in Argentina than in the United States. During the same period, Mexico registered the highest rate for kidney cancer and Colombia registered the highest rate for NHL, whereas the lowest rates were registered by Japan for kidney and by Japan and the United States for NHL. CONCLUSIONS: Improvements in the adoption of current integrated treatment protocols in Latin American and other lower- and middle-income countries worldwide would avoid a substantial proportion of childhood cancer deaths.

Environmental changes in the aftermath of Neoproterozoic glaciations: a biogeochemical study of sediments from SW-Gondwana

Abstract The late Neoproterozoic or Ediacaran period, (635 to -543 Ma) is a primordial time in the Earth history corresponding to the beginning of animal life and the most extreme ice ages on Earth. In this dissertation, palaeoenvironmental conditions were reconstructed for Ediacaran, post-Gaskiers shelf deposits in SW- Gondwana and their changes were evaluated according to the diversity of organisms. The present study addresses the question of interactions between biodiversity and environmental change by using the elemental and isotopic geochemistry of sedimentary rocks and associated organic matter, as well as the distribution of hydrocarbon biomarkers. The studied sedimentary sequences are from a large basin extended from the Paraguay belt to the Rio de la Plata craton, including the Corumbâ Group in SW-Brazil (Paraguay belt), the Arroyo del Soldado Group in Uruguay and the Sierras Bayas Group in Argentina (both in the Rio de la Plata craton). Several geochemical signatures of the sediments from Corumbâ and Sierras Bayas groups provides evidence for an euxinic setting in the Ediacaran Ocean: 1) The occurrence of syngenetic pyrite in the Corumbâ Group together with hydrocarbon biomarkers of an anoxic microbial consortium including traces of gammacerane, a distribution of hopanes with maxima at C29 as well as a low pristane/phytane (Pr/Ph) ratio; 2) the occurrence of 34S enrichments within sulfides of the Sierras Bayas Group exceeding the sulfur isotopic composition of coeval carbonate-associated sulfate. In the Arroyo del Soldado Group, an event of reducing conditions was revealed by higher concentrations of redox-sensitive trace elements and negative 513Ccar shifts in all sections. This event is extended to the whole unit in the deepest section and is restricted to tempestites in the two other shallow sections. The persistent negative. ôl3Ccar values recorded at the basinal setting implies strong isotopic gradient between shallow and deep water environments and therefore, a locus of deposition below the redox chemocline. In all studied sections, the excursions, the strong enrichment of authigenic trace-elements, the occurrence of longer chain «-alkanes, gammacerane and low Pr/Ph and Ph/>;-C]a ratios, combined with the previous sedimentological and paleontological observations indicate that the chemistry of the ocean was strongly controlled by the oxygen availability; waters being moderately oxic at the surface and anoxic at depth for much of the Neoproterozoic. This water column stratification was favourable to the storage of large amounts of nutrients in the deep ocean. During upwelling periods, the export of these nutrient-rich waters may have triggered an important bioproductivity in surface waters. Drops in Al3Cc,,.](Cr and positive ôl3Ccllr excursions highlight the increase in primary productivity. Preservation of organic carbon was ensured by reducing conditions at the bottom. The Al3ccar.kcr excursions could also reflect changes in the composition of the primary biomass. New geochemical evidence from SW-Gondwana sections supports a stratified Ediacaran ocean, outside restricted or hypersaline environments, in the aftermath of glaciations. The association of ocean stratification and the appearance of metazoans support the model that the evolution of eukaryotic life was related to the increase of oxygen levels in surface environments due to an efficient recycling of nutrients in the anoxic deep ocean. Résumé Le Néoprotérozoïque terminal, ou Édiacarien (635 à -543 Ma), est un période de première importance dans l'histoire de la Terre, car elle correspond a l'apparition des métazoaires pendant un intervalle de glaciations extrêmes. Le présent mémoire se propose de reconstituer les conditions paléoenvironnementales des dépôts de plateforme mis en place durant l'Édiacarien, au sud-ouest du Gondwana. Les interactions entre changements environnementaux et biodiversité sont évaluées en s'appuyant d'une part sur la composition élémentaire et isotopique des roches sédimentaires et de leur matière organique, et d'autre part sur la distribution moléculaire de biomarqueurs hydrocarbonés. Les séquences sédimentaires étudiées proviennent d'un grand bassin qui s'étend de la chaîne du Paraguay jusqu'au craton du Rio de la Plata. La séquence du Groupe Corumbâ au Sud Ouest du Brésil se situe dans la chaîne du Paraguay, tandis que le Groupe Arroyo del Soldado en Uruguay et le Groupe Sierras Bayas en Argentine sont situés sur le craton du Rio de la Plata. L'étude géochimique des sédiments des groupes Corumbâ et Sierras Bayas révèle de façon claire des conditions euxiniques dans l'océan édiacarien. On trouve ainsi, dans le Groupe Corumbâ, les biomarqueurs d'un cortège microbien anoxique et sulfurique comprenant des bactéries sulfato-réductrices, et dans les sulfures du Groupe Sierras Bayas, des enrichissements en Î4S excédant les rapports isotopiques du soufre dans le sulfate cogénétique associé aux carbonates. Dans la séquence de l'Arroyo del Soldado, un événement réducteur est mis en évidence par des teneurs plus élevées en éléments traces sensibles aux conditions redox et par des excursions négatives du 613Ccardans toutes les coupes. Cet événement affecte la totalité de la section la plus profonde et n'apparaît que dans les tempestites dans les sections les moins profondes. La persistance de valeurs négatives du ô13Ccarau large implique un gradient isotopique prononcé entre les environnements superficiels et profonds, et donc, ta présence d'une chémocline redox. Les excursions du. ôBCcar, l'enrichissement authigène en éléments traces, la présence de gammacérane et de rt-alcanes à longue chaîne, ainsi que de faibles rapports Pr/Ph et Ph/«-Cl8, viennent s'ajouter aux observations préliminaires sur la sédimentologie et la paléontologie pour indiquer que la chimie de l'océan était fortement contrôlée par la disponibilité d'oxygène, les eaux étant modérément oxiques à la surface et anoxiques en profondeur pendant la plus grande partie du Néoprotérozoïque. La stratification de la colonne d'eau était favorable au stockage de grandes quantités de nutriments dans l'océan profond. Dans les zones d'upwelling, la migration d'eaux profondes riches en nutriment vers la surface a pu provoquer une bioproductivité prononcée dans les eaux de surface. La conservation du carbone organique était assurée par les conditions anoxiques prévalant au fond. Les excursions du A13Ccar.kt.r pourraient aussi refléter des changements dans la biomasse primaire. Le présent travail apporte donc de nouvelles preuves qu'un océan stratifié s'est maintenu à la suite des glaciations néoprotérozoïques dans le Sud Ouest du Gondwana. L'association d'un océan stratifié et de l'apparition de la vie animale est en accord avec le modèle stipulant que l'évolution de la vie est associée à une meilleure oxygénation des environnements de surface. Résumé pour le grand public La période Ediacarienne (635 à -543 Ma) à la fin du Précambrien est l'une de plus énigmatiques dans l'histoire de la Terre, car elle est caractérisée par la diversification de la vie multicellulaire (eucaryote) pendant un intervalle de glaciations extrêmes. Dans ce travail de thèse, nous cherchons à déceler l'existence éventuelle d'un lien entre ces changements environnementaux et l'évolution de la vie eucaryote à travers une étude biogéochimique. La biogéochimie est l'étude des activités biologiques dans la géosphère, telles que celles intervenant dans les cycles des éléments chimiques (y compris les isotopes stables) et celles de production de composés carbonés caractérisant certains groups d'organismes ou taxons. La recherche des signatures paléoenvironnementales dans les roches précambriennes a été fortement facilitée par l'utilisation des biomarqueurs ou fossiles moléculaires. Ces composés, provenant des lipides biologiques (molécules avec des fonctions spécifiques dans les organismes), peuvent être reliés à des taxons spécifiques ou à des voies métaboliques. La transformation d'un biolipide en fossile moléculaire intervient lorsque des restes organiques déposés dans un substrat subissent un enfouissement et une augmentation de la pression (diagenèse). Ce processus mène à la formation de kérogène, un grand agrégat chimique de matière organique insoluble dans des solvants organiques, et de bitume ou fraction soluble (extractible) de la matière organique. L'analyse intégrée du kérogène et du bitume fournit des indications précieuses pour les reconstitutions paléoenvironnementales. Des conditions paléoenvironnementales ont ainsi été déterminées pour une plateforme marine Ediacarienne située dans la partie sud-américaine du bloc occidental du paléocontinent Gondwana. Les séquences sédimentaires étudiées appartiennent au même bassin qui s'étend de la ceinture du Paraguay (Groupe Corumbâ, Brésil) au craton du Rio de la Plata (Groupes Arroyo del Soldado, Uruguay et Sierras Bayas, Argentina). Nous nous sommes intéressés aux isotopes stables de carbonates et de la matière organique associée (kérogène et bitume), aux éléments majeurs et traces, ainsi qu'aux biomarqueurs caractérisant ces roches. Les résultats de cette dissertation suggèrent qu'au cours de l'Édiacarien, suite aux glaciations néoprotérozoïques dans le bloc occidental du Gondwana, l'océan était stratifié en zones spécifiques d'eaux riches en sulfures et dépourvues d'oxygène (euxiniques). L'association d'un océan stratifié et de l'apparition de la vie animale est en accord avec le modèle stipulant que l'évolution de la vie est associée à une meilleure oxygénation des environnements de surface. Les excursions isotopiques (tendance à des valeurs positives ou négatives) en constante fluctuation pour le carbone et très positives pour le soufre des sulfures, l'enrichissement en éléments trace et la présence de certains composés (e.g. gammacerane; Pr/Ph et Ph/«-Ci8 en basse proportion) conjugués aux observations sédimentologiques et paléontologiques des différents profils étudiés indiquent que la chimie de l'océan était fortement contrôlée par la disponibilité d'oxygène, avec des eaux modérément oxygénées en surface et euxiniques en profondeur pour la plupart du Néoprotérozoïque.

Recent patterns in gastric cancer: a global overview.

Until the mid-1990s, gastric cancer has been the first cause of cancer death worldwide, although rates had been declining for several decades and gastric cancer has become a relatively rare cancer in North America and in most Northern and Western Europe, but not in Eastern Europe, Russia and selected areas of Central and South America or East Asia. We analyzed gastric cancer mortality in Europe and other areas of the world from 1980 to 2005 using joinpoint regression analysis, and provided updated site-specific incidence rates from 51 selected registries. Over the last decade, the annual percent change (APC) in mortality rate was around -3, -4% for the major European countries. The APC were similar for the Republic of Korea (APC = -4.3%), Australia (-3.7%), the USA (-3.6%), Japan (-3.5%), Ukraine (-3%) and the Russian Federation (-2.8%). In Latin America, the decline was less marked, but constant with APC around -1.6% in Chile and Brazil, -2.3% in Argentina and Mexico and -2.6% in Colombia. Cancers in the fundus and pylorus are more common in high incidence and mortality areas and have been declining more than cardia gastric cancer. Steady downward trends persist in gastric cancer mortality worldwide even in middle aged population, and hence further appreciable declines are likely in the near future.