Geographic Regions Of Argentina Research Articles

Microsatellite variation in Helicoverpa gelotopoeon (Lepidoptera: Noctuidae) populations from Argentina

Abstract Helicoverpa gelotopoeon (Dyar) (Lepidoptera: Noctuidae) is a polyphagous pest that has been reported causing damage in many agricultural crops such as soybean, chickpea and cotton. This species, together with Helicoverpa zea (Boddie), Helicoverpa armigera (Hübner) and Chloridea virescens (Fabricius), belongs to the Heliothinae complex of economic importance in Northwestern Argentina. Many species in the Heliothinae subfamily have developed resistance to insecticides and insecticidal proteins from Bacillus thuringiensis (Bt). Managing resistance to these control tactics in H. gelotopoeon is of high importance and dependant on knowledge of population genetics of this species. The objective of this study was to evaluate the genetic variability and structure of H. gelotopoeon populations from different host plants and geographic regions of Argentina. Towards this goal, six microsatellite loci were screened across 196 individuals. The results obtained revealed high genetic diversity and lack of clear structure among the populations of H. gelotopoeon studied. This genetic homogeneity between populations from different geographical regions and hosts could be attributed to the long‐range migratory capacity of Heliothinae and the generalist behaviour of H. gelotopoeon.

Is Acarapis woodi mite currently infesting Apis mellifera colonies in Argentina?

The honey bee tracheal mite Acarapis woodi (Rennie) (Acari: Tarsonemidae) is an internal obligate parasite of the respiratory system of adult honey bees (Apis mellifera), which may be one of the factors causing the loss of bee colonies and the decrease in the beekeeping industry. In Argentina, the last prevalence study of A. woodi was in 1998, and therefore there is no current data on the prevalence and impact of the mite in colonies of A. mellifera in this country. For this reason, the objective of this study was to determine the prevalence of A. woodi in honey bee colonies of apiaries belonging to different geographic regions of Argentina (Northwest, Chaco, Mesopotamic, Pampean and Patagonic) using two different methods of diagnosis. One method was traditional microscopy, which is based on direct visualization of A. woodi in the prothoracic tracheas of bees, and the other technique was molecular analysis using real-time PCR with specific primers to amplify CO1 gene of A. woodi. To perform the analysis of prevalence, bees were collected during winter, because during this season, populations of A. woodi are more abundant in bee colonies. The results were negative for both methods of diagnosis, with prevalence equal to 0%. Considering that in recent years it has been reported an increased mortality in bee colonies in Argentina, we note that acarapisosis is not currently impacting on the disappearance of A. mellifera colonies in Argentina.

Geographical Distribution of Pyrethroid Resistance Allele Frequency in Head Lice (Phthiraptera: Pediculidae) From Argentina

The human head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae), is an obligate ectoparasite that causes pediculosis capitis and has parasitized humans since the beginning of humankind. Head louse infestations are widespread throughout the world and have been increasing since the early 1990s partially because of ineffective pediculicides. In Argentina, the overuse of products containing pyrethroids has led to the development of resistant louse populations. Pyrethroid insecticides act on the nervous system affecting voltage-sensitive sodium channels. Three point mutations at the corresponding amino acid sequence positions M815I, T917I, and L920F in the voltage-gated sodium channel gene are responsible for contributing to knockdown resistance (kdr). The management of pyrethroid resistance requires either early detection or the characterization of the mechanisms involved in head louse populations. In the current study, we estimated the distribution of kdr alleles in 154 head lice from six geographical regions of Argentina. Pyrethroid resistance kdr alleles were found in high frequencies ranging from 67 to 100%. Of these, 131 (85.1%) were homozygous resistant, 13 (8.4%) were homozygous susceptible, and 10 (6.5%) were heterozygous. Exact tests for the Hardy-Weinberg equilibrium for each location showed that genotype frequencies differed significantly from expectation in four of the six sites studied. These results show that pyrethroid resistance is well established reaching an overall frequency of 88%, thus close to fixation. With 30 yr of pyrethroid-based pediculicides use in Argentina, kdr resistance has evolved rapidly among these head louse populations.

Births prevalence of 27 selected congenital anomalies in 7 geographic regions of Argentina

The aim of the present work was to estimate the frequency of 27 birth defects in 7 geographical regions of Argentina. Observational, cross-sectional, descriptive design. A sample of 21,844 new born with birth defects was selected, ascertained from 855,220 births, between 1994 and 2007, in 59 hospitals belonging to the ECLAMC network. In order to identify regions of high frequency a Poisson regression was used, adjusted by different hospitals from the same region. The model included a time variable to detect secular trends and 6 dummy variables for 7 predefined geographical regions: Metropolitana (MET); Pampa (PAM); Centro (CEN); Cuyo (CUY); Noroeste (NOA); Nordeste (NEA) and Patagonia (PAT). High frequencies regional analysis showed the following significant results: PAM: severe hypospadias; CEN: spina bifida, microtia, cleft lip with cleft palate, polycystic kidney, postaxial polydactyly and Down syndrome; CUY: postaxial polydactyly; NOA: omphalocele, gastroschisis, cleft lip without cleft palate, cleft lip with cleft palate, anorectal atresia/stenosis, indeterminate sex, preaxial polydactyly and pectoral agenesis; PAT: cleft lip without cleft palate. Out of the 27 congenital anomalies analyzed, fourteen showed a frequency significatively higher in one or more regions.

Discourse, meaning, and political participation

We present an analysis of part of a data-set from a three-year study called ‘Work, Development and Diversity’ conducted by a network of Argentinean public and private research institutions. We sought to analyze the different ways in which strategic planning for local development, with a participatory approach, had been implemented in four geographic regions of Argentina. In this article we analyze how (1) participants in a given field of practice build strategic discursive actions and orient their interactions guided by their perception of who is included, and in what aspects of the process at stake; (2) participants build discourses that shape what counts as reality. Our analysis shows what happens when participants come together, since they dispute what counts as true, valid or even real, and these disputes can be analyzed through discourse; what may appear to be a linguistic detail is loaded with meaning due to the historical context in which the specific cultural terms are produced (e.g. participant, neighbor, and activist). We also show that in calls for participatory action, any specific community of participants may impose what they determine to be true over the others. When this is achieved, one may say that they have managed to impose a certain simplifying operation over the other participants, thus making it possible for their logic to prevail, and to reduce a certain amount of complexity at play.

Molecular characterization of avian infectious bronchitis virus strains from outbreaks in Argentina (2001–2008)

Twenty infectious bronchitis virus isolates were recovered from broilers and layers in different outbreaks amongst commercial poultry flocks in different geographic regions of Argentina from 2001 to 2008. The viruses were isolated from the tracheas, lungs, and caecal tonsils of birds that were showing respiratory signs. Further analysis based on their nucleotide and amino acid sequences in hypervariable region (HVR) 1 and the intervening sequence including HVRs 1 and 2 (HVR1/2) of the S1 gene was done to determine the genetic relationships among them and reference strains. Five isolates were highly related to the Massachusetts or Connecticut serotypes, indicating the probability of the detection and isolation of vaccine strains. The other Argentinean isolates formed three separate clusters (A, B and C), distant from the vaccine serotypes, with no correlation between the generated clusters and a geographic pattern. These observations could explain the failure of the Massachusetts serotype vaccination programmes to control IBV in these flocks. In addition, the utilization of HVR1/2 and HVR1 sequences resulted in trees with similar topology but the phylogenetic relationships using HVR1/2 nucleotide sequences were better supported by higher bootstrap values. Therefore, the sequences of the HVR1/2 region are recommended for phylogenetic studies.

Major flavonoids of Argentinean honeys. Optimisation of the extraction method and analysis of their content in relationship to the geographical source of honeys

In the present research we optimised an extraction procedure for the flavonoid aglycones: myricetin, quercetin and luteolin from honeys (as natural biological matrices), based on Amberlite XAD-4 resin followed by HPLC quantification. In addition, honeys from three geographical regions of Argentina were analysed with regard to the contents of these flavonoids. The extraction procedure was optimised for XAD-4 resin considering: resin/honey ratio, elution volume to desorb flavonoids and colour intensity of honeys. Differences in flavonoid recoveries were observed depending on the colour intensity. The flavonoid aglycones contents, in accordance with differences in geochemical characteristics and typical vegetation, varied with the geographical origin of honeys. The results obtained allowed us to consider these three flavonoids as chemical markers for the phytogeographical origin of honeys. In the case of monofloral honeys, the contribution of each one of the flavonoids was associated with the presence of a dominant pollen kind in these samples.

Phenotypic diversity in wild Helianthus annuus from Argentina

SUMMARY Wild Helianthus annuus populations naturalized in central Argentina have spread since their introduction from the center of origin in North America. Phenotypic characterization based on 45 morphological and phenological descriptors of nine populations from different geographic regions of Argentina and 17 populations from the USA provided by the US Department of Agriculture germplasm bank at Ames, Iowa, was obtained by growing populations in an experiment field. Wild populations from Argentina reflected part of the phenotypic variability of populations from the center of origin, but showed adaptation to local conditions which allows differentiation between populations from each continent. All traits showed a continuous range, with majority of extreme values occurring in populations from North America. The populations that showed similarities for one group of descriptors differed in other traits, revealing the existence of different phenotypes. Helianthus annuus populations established in Argentina could be considered a differentiated genetic resource, containing new combinations and traits absent in North American populations, such as the life cycle length in the Diamante population of 180 days and longer, the longest of any population studied. RESUMEN Poblaciones naturalizadas de Helianthus annuus silvestre se han dispersado a partir de su introducción desde el centro de origen, en Norteamérica. La caracterización fenotípica basada en 45 descriptores morfológicos y fenológicos de nueve poblaciones procedentes de diferentes regiones geográficas de Argentina y 17 poblaciones de USA, provistas por el US Department of Agriculture germplasm bank en Ames, Iowa fue realizada cultivándolas en un campo experimental. Las poblaciones silvestres de Argentina reflejaron parte de la variabilidad fenotípica de las poblaciones provenientes del centro de origen, aunque mostraron adaptación a condiciones locales, lo que permitió la diferenciación entre poblaciones de cada continente. Todos los caracteres mostraron un rango continuo de variación, con la mayoría de los valores extremos observados en las poblaciones Norteamericanas. Las poblaciones que mostraron similaridad para un grupo de caracteres difirieron en otros, revelando la existencia de diferentes fenotipos. Las poblaciones de Helianthus annuus establecidas en Argentina podrían ser consideradas un recurso genético diferente, con nuevas combinaciones de caracteres presentes en las Norteamericanas y algunos ausentes en estas últimas, como el largo de ciclo de Diamante de más de 180 días, el periodo más largo entre las poblaciones estudiadas. RÉSUMÉ Des populations naturalisées de Helianthus annuus sauvage se sont dispersées à partir de son introduction depuis le centre d'origine, en Amérique du Nord. La caractérisation phénotypique basée sur 45 descripteurs morphologiques et phénologiques de neuf populations originaires de différentes régions géographiques de l'Argentine et de 17 populations des États-Unis, fournies par le banc de germoplasme du Département d' Agriculture d’Amérique du Nord à Ames, Iowa, a été réalisée en les cultivant dans un champ expérimental. Les populations sauvages de l'Argentine ont exhibé une partie de la variabilité phénotypique des populations procedentes du centre d'origine, bien qu'elles ont montré d’adaptation aux conditions locales, ce qui a permis la différenciation entre les populations de chaque continent. Tous les caractères ont montré un rang de variation continu, avec la plupart des valeurs extrêmes observées dans les populations Nord-américaines. Les populations qui ont montré similitude pour un groupe de caractères ont différé pour les autres, en révélant l'existence de différents phénotypes. Les populations de Helianthus annuus établies en Argentine pourraient être considérées comme une ressource génétique différente, avec de nouvelles combinaisons de caractères présents dans les populations Nord-américaines et certains caractères absents dans celles-ci, comme la longueur du cycle dans Diamant de plus de 180 jours, la période la plus longue entre les populations étudiées.

Cost-effectiveness of childhood hepatitis A vaccination in Argentina: a second dose is warranted

To investigate the cost-effectiveness of childhood vaccination against hepatitis A in the five geographic regions of Argentina, and to determine whether adding a second dose to the current one-dose schedule would provide health gains justifying its added cost. A Markov model was used to consider four immunization options for the 2005 birth cohort: (1) no vaccination; (2) vaccination at 12 months of age, (3) vaccinations at 12 and 72 months of age; or (4) vaccinations at 12 and 18 months of age. Hepatitis A costs and consequences were predicted over 50 years. The cost-effectiveness of first and second vaccine doses was assessed through a range of vaccine prices and assumptions regarding the duration of vaccine protection. Costs and health gains (measured in quality-adjusted life years) were adjusted to present values using a 3% annual discount rate. The one-dose vaccination policy is predicted to reduce each birth cohort member's 50-year probability of overt hepatitis A from 7.2% to 4.1%. A second dose would reduce the probability to between 2.0% and 2.2%. Vaccination at 12 months of age, at 12 and 72 months, or at 12 and 18 months would reduce cases among personal contacts by 82%, 87%, and 92%, respectively. The first vaccine dose would meet accepted standards of cost-effectiveness in each region, and reduce costs in the Northeast, Central, and South regions. Adding a second dose at age 18 months would be cost-effective in each region, and further reduce costs in the Cuyo region. If the duration of protection with one dose is less than anticipated, the second dose would be more cost-effective. Greater health gains are derived from the first than second hepatitis A vaccine dose. However, this analysis supports the cost-effectiveness of providing both first and second doses to Argentina's children.

La relación entre los factores socioeconómicos y los programas sanitarios de salud maternoinfantil en 13 provincias argentinas

To analyze the relationship between maternal and infant health and socioeconomic, cultural, and sanitation factors in Argentina; to evaluate how health program quality affects the primary health indicators for mothers and infants. This is a cross-sectional study with multiple variables. The authors studied six indicators for maternal and infant health: rates for maternal, infant, neonatal, and postneonatal mortality; the percentage of newborns with low birthweight; and the percentage of premature newborns. The study was conducted in 79 administrative units in 13 provinces that represent different geographic regions of Argentina. They included (1) the provinces of Salta and Jujuy in northwest Argentina; (2) the provinces of Córdoba, Santa Fe, and Buenos Aires in central Argentina; (3) the provinces of Entre Ríos and Misiones in the Mesopotamia or northeast region; (4) the provinces of San Luis, San Juan, and Mendoza in the Cuyo or northwest, Andean region; and (5) the provinces of Neuquén, Río Negro, and Chubut in the south. The explanatory variable in the study was the quality of health programs, controlled by socioeconomic, cultural, and sanitation factors in 1999 and 2000. The definition of program quality ("poor," "average," "good," and "very good") was based on quantitative and qualitative analysis of selected variables such as policies, organization, and procedures as determined by the investigators. Documentation was obtained from secondary official sources. The investigators interviewed 117 health system managers (including supervisors of provincial and local health programs, administrators of maternal and child health programs, and hospital directors), who provided information on characteristics and indicators of the health programs. There were marked geographic differences in the levels of maternal and infant health, medical care, and socioeconomic, cultural, and sanitation factors. Only 10.0% of health programs were classified as "very good," 35.4% as "good," 31.6% as "average," and 23.0% as "poor." There was a significant correlation (P < 0.05) between rates of infant and postneonatal mortality and adverse socioeconomic circumstances. There was also a significant correlation between the percentage of low birthweight infants and the quality of health programs. There are clear disparities in the level of maternal and infant health care in different administrative units in Argentina. The infant mortality rate was associated with variations in socioeconomic, cultural, and sanitation factors and with the quality of health programs. Health programs improved infant health when appropriately implemented, even in adverse socioeconomic and sanitation conditions.

Analysis of clonal relationship amongShigella sonneiisolates circulating in Argentina

SUMMARYThirty-five isolates ofShigella sonneifrom patients with diarrhoea in three geographic regions of Argentina were examined for genetic diversity by pulsed-field gel electrophoresis (PFGE) and plasmid profile. PFGE ofXbaI andBlnI DNA digests confirmed the occurrence of outbreaks in two regions caused by two separate predominant clones ofS. sonnei. The third region was characterized by three circulating clones, one of which was possibly associated with an outbreak. Similar plasmids were found in distinct clones and in one outbreak clone five different plasmid profiles were identified. Antimicrobial resistance of the isolates varied from fully susceptible to the agents tested, to resistance to cotrimoxazole, ampicillin and ciprofloxacin. Antibiotic resistance did not correlate with plasmid content. This information will form the basis for active surveillance of shigellosis in Argentina and elsewhere in the region through the PulseNet International Network.

Distribution of Botulinum Toxin-Producing Clostridia in Soils of Argentina

We studied the presence of botulinum toxin-producing clostridia in 2,009 soil samples from five geographical regions of Argentina. The prevalence was 23.5%, and the distribution was not homogeneous among the regions. We observed a great multiplicity of serological types and a higher prevalence in nonvirgin soils than in virgin soils.

Seroprevalence of human herpesvirus-8 in blood donors from different geographical regions of Argentina, Brazil, and Chile.

Human herpesvirus-8 (HHV-8) causes Kaposi's sarcoma (KS) and lymphoproliferative disorders in both HIV-infected and uninfected patients. HHV-8 has a worldwide occurrence but infection rates vary according to a combination of geographic and behavioral risks. The main transmission route seems to be sexual, nevertheless, nasal secretions, saliva, blood, and organ graft have been proposed. HHV-8 was postulated as a new infectious agent for screening in blood donors. The aim of this study was to evaluate the prevalence of antibodies against HHV-8 antigens in blood donors of South America. Serum samples from 2,470 blood donors from Argentina, Brazil, and Chile corresponding to five geographic regions were studied by indirect immunofluorescence assay (IFA). Seroprevalence rate was 3.7% (92/2,470; 95% CI 2.9-4.5) in the entire blood donor population distributed as follows: Argentina, 4.0% (Buenos Aires city, 4.3%; Bahia Blanca, 2.4%; and Córdoba, 4.0%), Campinas (Brazil), 2.8%; and Santiago de Chile, 3.0%. There was no difference (P>0.05) between men and women or age related, except in Brazil where positive cases were 30-49-year-old males. The present study, which includes different geographical areas of multiple countries from South America, has not been done before. The results show similar prevalence rates among the studied zones corresponding to low-prevalence regions. South America is a large sub-continent with a wide spectrum of population and geographical characteristics, thus, more HHV-8 prevalence studies should be necessary to establish possible regional differences.

Terpenoid constituents of Viguiera tucumanensis

Two varieties of Viguiera tucumanensis, collected in two different geographical regions of Argentina, were shown to have a very close chemical constitution. They all gave the new diterpene clerod-14-ene-3α,4β,13ζ-triol. The taxonomic implications are discussed briefly.