North Of Argentina Research Articles

Molecular Epidemiology of Chagas Disease in Venezuela

American Trypanosomiasis or Chagas’ disease is endemic of the American continent with a wide distribution from the South of United States to North of Argentina. The etiological agent is the parasitic protozoan Trypanosoma cruzi which is transmitted by blood sucking triatomine bugs through contaminated feces. According to the last consensus meeting in 2009, T. cruzi has been divided in six groups or discrete typing units (DTU), also names genotypes, from TcI to TcVI. The geographical distribution of T. cruzi genotypes in the American Continent has some particularities. For instance, genotypes TcII, TcV and TcVI are found infecting humans at the Southern cone, whereas TcI and TcIV are the genotypes prevalent from the Amazon basin to Central and North America. In Latin America, for decades TIV was considered mainly sylvatic with very rare occasion of human infections. A recent study in Venezuela reported TcI, TcIII and TcIV circulating in domestic and sylvatic cycles, but only genotypes TcI and TcIV have been identified infecting humans in different regions of the country. Around 79% of the patients have been found infected with TcI and the remaining with TcIV. In this study we have made the follow up of 30 chronic chagasic patients showing that the clinical outcome of people infected with TcI shows to be more severe than those infected with TcIV, suggesting that TcI genotype is in general more pathogenic than TcIV. We have detected triatomine bugs and wild mammals naturally infected with TcIII, but no human infection with this genotype has been identified so far. Murine models indicate that T. cruzi isolates belonging to TcI genotype shows to be more virulent and pathogenic than TcIV. The biological behavior of TcI and TcIV isolates indicate a significant association with the clinical manifestation in the chronic patients.

Phylogenetic relationships among populations of the Nacobbus aberrans (Nematoda, Pratylenchidae) complex reveal the existence of cryptic species

The plant‐parasitic nematode Nacobbus aberrans sensu lato is an agricultural pest of quarantine importance. Due to the morphometric, physiological and genetic variability observed within the species, there is no agreement on the taxonomy of this nematode. The objective of this study was to analyse the ITS rDNA region and the D2–D3 expansion segments of 28S rDNA in 10 Argentine populations and one from Ecuador and to establish their phylogenetic relationship with other known sequences from South and North America. Phylogenetic trees of the ITS gene showed seven statistically well‐supported clades; the high and significant Fst values obtained among these groups confirmed this partitioning. The Argentine populations here considered were separated into three clades: one comprising a population from the Andean region and two grouping nematodes from lower altitudes. Three other clades were distinguished for South American populations, which included known sequences of individuals from Peru, Bolivia and north of Argentina. The other clade included sequences from Mexico, Ecuador and two Argentine populations of unknown origin. The important degree of genetic divergence observed among Andean populations suggests that the Andes may have played a crucial role in speciation of Nacobbus, which would have originated in this region. Although D2–D3 segments exhibited lower variation, they were useful for establishing phylogenetic relationships among the Argentine populations considered in this work. As there are no other GenBank sequences available for these segments, it was not possible to make comparisons with other populations from South and North America. The considerable genetic differentiation observed in ITS rDNA region among Nacobbus populations showed evidence of cryptic species within the N. aberrans s.l. complex. Integration of morphological and morphometric studies and molecular analyses considering other genes may aid in the identification of species and their phylogenetic relationships within this genus.

Cretaceous cicatricose spores from north and central-western Argentina: taxonomic and biostratigraphical discussion

Cicatricose spores have been described from Cretaceous basins worldwide. A complete revision of previous records from Argentina and other parts of South America is presented here, as well as the results of a detailed taxonomic study of the species found in the La Yesera and Lagarcito formations (north and central western Argentina, respectively). Four genera and 11 species are described: Cicatricosisporites cuneiformis, C. pramparoana, C. sp. 1, Fisciniasporites sp. cf. F. brevilaesuratus, F. sp., Nodosisporites sp., Ruffordiaspora australiensis, R. cardielensis, R. ludbrookiae, R. cf. R. ticoensis and R. sp. 1. The genus Fisciniasporites is recorded for the first time in Argentina (La Yesera Formation), and Nodosisporites in the San Luis Basin. The abundance of the cicatricose spores is higher in the La Yesera Formation (8–54.2% of the total assemblage) than in the Lagarcito Formation (2–16%). An acme of cicatricose spores diversity in Argentina was recognized during the Aptian–Albian interval. Taxonomic studies of these types of spores are very important as they constitute a useful contribution of accurate descriptions and illustrations within a morphologic group that has many misidentifications, and also considering the biostratigraphic significance of some species, e.g. Cicatricosisporites cuneiformis in Australia.

Characterisation of nutrient profile of quinoa (Chenopodium quinoa), amaranth (Amaranthus caudatus), and purple corn (Zea mays L.) consumed in the North of Argentina: Proximates, minerals and trace elements

Quinoa, amaranth and purple corn are Andean cereals largely consumed in North of Argentina. Nutrient analysis with the purpose of inclusion in the Argentinean FCDB and e-search EuroFIR has become urgent matter. In this work proximate and mineral profile of Andean cereals cultivated in the North of Argentina were determined and compared with rice. Proximate analysis showed that Andean cereals have similar profile but significantly higher (p<0.05) than rice. Andean cereals are rich sources of iron, copper, manganese and zinc and better than rice. Phosphorus and magnesium quinoa content could contribute up to 55% of consumers DRI. Andean cereals and rice are poor sources of potassium. To guarantee the interchange of data among users and producers of FCDB component values were obtained in compliance with EuroFIR guidelines for compilation process. Present work provides necessary information to FCDB users who wish to have access to food reference analytical parameters.

Primera identificación de Echinococcus vogeli en una paca en la provincia de Misiones, Argentina

We report the first finding of Echinococcus vogeli in a paca, Cuniculus paca, in the tropical forest of Misiones, in the north of Argentina. The presence of the bush dog, Speothos venaticus, E. vogeli's only natural definitive host, was also reported. The polycystic hydatids, 2 to 3cm in diameter, were only found in the liver of an adult paca. The size range of the hooks and the relative proportion blade/handle did not show significant differences with respect to the ones reported for E. vogeli. The size of E. granulosus hooks, measured for comparison purposes, was significantly smaller (p<0.0001). These results confirmed the presence of E. vogeli in Argentina. The probability of finding neotropical echinococcosis in humans reinforces the need to expand the search for E. vogeli in Argentina. Echinococcosis due to E. vogeli is very aggressive and may cause death in about a third of the human population affected.

NUEVOS HALLAZGOS DE HELMINTOS PARÁSITOS EN CHRYSOCYON BRACHYURUS (CARNIVORA: CANIDAE) EN ARGENTINA

Los estudios sobre las parasitosis de cánidos y en particular de Chrysocyon brachyurus Illiger, 1815 son escasos y existen pocos registros en el norte argentino. El objetivo del presente estudio fue ampliar el conocimiento acerca de los helmintos parásitos de C. brachyurus. Se llevaron a cabo las necropsias de dos ejemplares adultos de C. brachyurus de dos áreas protegidas de Corrientes (Argentina). El material biológico consistió en vísceras de un macho proveniente del Parque Nacional Mburucuyá y de una hembra de la Reserva Provincial Rincón de Santa María. A partir de la necropsia del ejemplar proveniente del Parque Nacional Mburucuyá, se hallaron helmintos localizados en el intestino (Centrorhynchus guira Lunaschi &amp; Drago, 2010 y Ancylostoma caninum Ercolani, 1859) y en el riñón derecho (Dioctophyme renale Goeze, 1782). El ejemplar proveniente de la Reserva Rincón de Santa María presentó únicamente Mesocestoides sp. Vaillant, 1863, localizado en el intestino delgado. Se registra por primera vez las asociaciones C. guira– C. brachyurusy Mesocestoides sp. – C. brachyurus.

In vitro antimicrobial activity of 20 selected climber species from the Bignoniaceae family

Hydroalcoholic and aqueous extracts of some climber species from the Bignoniaceae family that grow in the north of Argentina were evaluated for in vitro antibacterial activity against Gram-positive and Gram-negative strains. By means of bioautography and disc diffusion methods, it could be determined that all infusions were not active, whereas the hydroalcoholic extracts of seven species were able to inhibit bacterial growth. The minimum inhibitory concentration and minimum bactericidal concentration observed were between 62.5 and 1000 μg gallic acid equivalent (GAE)/mL and between 125 and 1000 μg GAE/mL, respectively. The tested extracts were more active against Gram-positive microorganisms. Time-kill experiments indicated that all extracts have bacteriostatic activity. Phytochemical screening showed the presence of terpenoids, phenols and flavonoids. The amount of phenolic compounds and flavonoids was higher in tinctures when compared with infusions. These results suggest the presence of antibacterial substances in the hydroalcoholic extracts, which could be used for the treatment of infections.

Anaerobic treatment of residual lemon pulp in digesters with semi-continuous feed

Lemon growing areas in the north of Argentina have industries that produce concentrated juice, peel and essential oil and generate a significant amount of liquid and solid waste as lemon pulp. In Argentina, despite the potential applications that the pulp has as animal feed and human and industrial raw material, only 10% is used for these purposes and the rest is discarded into the environment causing many ecological and economic problems. There is little information in the literature on biotechnologies for the treatment of this industrial waste. This paper shows that lemon pulp is a suitable substrate to be treated by anaerobic digestion. We obtained 86 and 92% reduction of chemical oxygen demand in a digester with a semi-continuous feed and retention time of 10 and 20 days respectively and a productivity of 0.406 g CH(4)/g VS h. Comparative tests showed that pre-digesting the pulp improved the process of digestion and increased biogas generation by 20%.

Evolución del delta del río Paraná y su posible vinculación con el calentamiento global

Evolution of the Paraná River Delta and its possible relationship to Global warming. Tthis paper discusses the recent geomorphological evolution of the Paraná Rriver Ddelta on the basis of cadastral information, old topographic and nautical charts and satellite images. evolution is linked to the consequences of global warming in the region of the Rrío de la Plata, particularly to the erosive processes. Tthese processes are very active in areas close to the delta, especially in the Samborombón Bay. However, in the Paraná not there was a decrease in their rhythm of progradation, on the contrary, it has remained constant or even has quickened. is probably due to increased sedimentary load by the Paraná in response to the increase of precipitation recorded since the 1970s in the region center and north of Argentina. As this is a direct consequence of global warming, or local climate variability, it may be said that the climate factor is also responsible for the aforementioned progradational dynamics.

El género Heterodermia (Lecanorales - Physciaceae) en el centro norte de Argentina

Como parte de un trabajo taxonómico que tiene por objetivo revisar las especies foliosas de Physciaceae que crecen en el centro y norte de Argentina se describió la morfología, anatomía y química de especímenes de Heterodermia coleccionados recientemente en estas regiones. Se citan por primera vez para Argentina Heterodermia japonica y H. fertilis, se amplía el rango de distribución de once especies dentro del país y se presenta una clave dicotómica y una breve descripción de cada una las especies estudiadas.

Middle Holocene intensification and domestication of camelids in north Argentina, as tracked by zooarchaeology and lithics

Using a detailed excavated sequence and a broad range of south Andean sites, the authors show that changes in the bones of camelids and in the lithic assemblages offer an account of how animals were intensively exploited and ultimately domesticated between the sixth and fourth millennia BP.

The relative role of Amazonian and non-Amazonian fires in building up the aerosol optical depth in South America: A five year study (2005–2009)

In South America (SA) biomass burning is the major source of atmospheric aerosols. Fires are mostly registered in the dry season (July–November) and are mainly concentrated in the Amazonia and Cerrado regions. Nonetheless, the growing systematic employment of fires for land clearing and pasture maintenance across the SA continent is introducing other, potentially significant, sources of BB aerosols. This study investigates the relative contributions of different SA biomass burning regions in building up the continental aerosol load. To this purpose, the SA continent is divided into four biomass burning source regions and their impact on the aerosol optical depth (AOD) is evaluated in eight different SA target domains. The dataset used includes multi-year (2005–2009) satellite observations of both aerosol and fires and model-based atmospheric trajectories. The methodology followed couples fire counts and atmospheric transport through the definition of a specific quantity, referred to as ‘fire weighted residence time’ (FWRT), which is used to assess the contribution of the four identified fire source regions to the continental aerosol load.Results show that local fires play an important role in building up the regional aerosols load all over SA. Nevertheless, in some regions, contribution of BB aerosols transported from outside their boundaries is comparable to the local one. The major ‘smoke exporter’ regions are found to be the eastern Brazil and the Amazonia–Cerrado regions. In the dry season, due to the typical continental circulation pattern, the first is estimated to contribute to half of the AOD in Northern Amazonia, Southern Amazonia and Cerrado regions, while over 30% of the AOD in Paraguay and North Argentina derives from the Amazonia–Cerrado fires. Due to the presence of the inter-tropical convergence zone, which decouples wind circulation of the two hemispheres, regions north of the Equator (Venezuela, Guyana, Suriname) are found to receive almost no contribution to the local AOD from fires occurring in the nearby active regions of Amazonia and Caatinga. Similarly, Venezuela fires are shown not to impact the Northern Amazonia AOD. Finally, in excluding the continental fire driver of some AOD enhancements observed in the wet season, this study indirectly points to an important role of aerosol transoceanic transport from Africa.

First report on HIV molecular epidemiology in a native community from Argentina reveals transmission clades in the context of a unique HLA background

Background The Department of Oran is located on the North of Argentina and is populated by native settlements and urbanized areas. During the last twelve years, an increasing number of HIV infections have been detected. We previously reported a highly limited HLA diversity with a reduced number of HLA-A and B alleles present at high prevalence. The objective of the present study was to characterize the HIV epidemic through full-length genome sequencing of the virus in this population. Methods Samples from 147 HIV positive individuals collected in three campaigns to Oran were analyzed. Viral load, CD4count and drug resistance were assessed and reported to the clinicians. Limiting-dilution full genome sequencing was performed from plasma on 65 of the samples. Viral diversity was analyzed by recombination (SimPlot) and Neighbor-Joining trees with bootstrap. HLA-A, B and C were characterized by SBT. Results HLA typing showed a limited genetic diversity even at the four-digits high-resolution typing. This allele distribution resembles the one reported previously for this community with two-digits and confirms that the individuals included were in fact native. SimPlot analysis of the 65 complete and nearly-complete genomes showed a high prevalence of BF recombinants(70.77%) and the presence of subtype B(23.08%), C(3.08%) and F(3.08%) virus. 7 main recombination structures were found repeatedly in not-epidemiologically-linked individuals within highly supported monophyletic clades suggesting transmission of these particular viral strains within the community. Conclusion This HIV epidemic seems to be characterized by a few

Sequence based typing of HLA-A and B Exons-2 and -3 in a HIV-positive native community with limited HLA diversity from the North of Argentina

Methods We studied 65 HIV-positive patients whose HLA-A and -B genes were previously typed by SSOP technique. We setup a sequence-based typing of the most prevalent alleles in Oran. HLA-A and B were initially PCR-amplified and exons-2 and -3 were sequenced. NCBI-SBT-Interpretation tool was used to confirm the two-digits typing with previous SSOP data. We designed a set of primers specifics for HLAs highly prevalent in Oran to achieve differential PCR-amplification of each allele in heterozygote patients. Phylogenetic analysis was used to assign exons-2 and -3 sequences to a high-resolution HLA group.

Dengue en la Argentina: un análisis económico del impacto de la epidemia de 2009

The present study estimates the economic burden associated with the cases of dengue recorded during the 2009 Argentine epidemic. Among the costs considered are the medical costs necessary for the treatment of those affected and the opportunity costs for those who stopped working or studying because of the disease. In order to assess the costs of the disease, at the end of 2009 an ad-hoc survey was carried out in 201 households where people that had contracted dengue during the 2009 epidemic lived. The results allow us to estimate between 26 to 40 million Argentine pesos (6 to 9 million US dollars) as the total cost of the recorded cases. The regions in the north of Argentina bore the highest economic burden of the disease (more than 90% of the total burden). For all regions, the social cost of one dengue case accounts for more than 40% of the average monthly net individual income.

On the use of niching genetic algorithms for variable selection in solar radiation estimation

Abstract Prediction of climatic variables, in particular those related to wind and solar radiation, has developed a huge interest in recent years, mainly due to its applications to renewable energy. In many cases there is a large number of factors that influence the climatic variable of interest, and the researcher chooses the most relevant ones (based on previous knowledge of the region, availability, etc.) and runs a series of experiments combining the available data in order to find the combination that provides the best prediction. In this work we present two applications of Niching Genetic Algorithms to solve the problem of selection of variables for the estimation of Solar Radiation. On one hand, this methodology is able to estimate a given climatic variable using databases with missing data, since the algorithm can compensate it by the use of others. On the other hand, we present a methodology that allows us to select the relevant input variables for a given climatic variable estimation or prediction problem, in a systematic way, using the same Genetic Algorithm with different parameters. Both methods were tested in the estimation of daily Global Solar Radiation in El Colmenar (Tucuman, Argentina), using linear regression on data from 14 weather stations spread along the north of Argentina. The results obtained show that the methodology is appropriate, providing an RMSE = 2.36 [MJ/m2] and R = 0.926 using an average of 64 out of 329 initial variables, on a 70 individuals/85 generations combination. For a 200 individuals/150 generations combination it obtained an RMSE = 2.34 [MJ/m2] and R = 0.928 using an average of 54 variables.

Genetic diversity of maize landraces from lowland and highland agro‐ecosystems of Southern South America: implications for the conservation of native resources

AbstractThe North of Argentina is one of the southernmost areas of maize landrace cultivation. Two distinct centres of diversity have been distinguished within this region: Northwestern Argentina (NWA), and Northeastern Argentina (NEA). Nowadays, maize landraces from this area are faced with two main risks. On the one hand, significant structural and functional changes have modified the rural environment with the boundaries of cropland areas experiencing a rapid expansion at the expense of northern natural forests and rangelands; and on the other, native gene pools are increasingly threatened by hybrids and commercial varieties which are more attractive relative to landraces. The first step towards any conservational action is the acquisition of an inclusive knowledge of the biological resources. For this purpose, our study assesses the genetic diversity and population dynamics of maize landraces from Northern Argentina using microsatellite markers. The Northeastern lowland region (NEA) was represented by 12 landraces (19 populations). In addition, six landraces (eight populations) from the Northwestern highland region (NWA) were used for comparison. For the NEA data set, a total of 126 alleles were found, with an average of 10.5 alleles per locus. Mean Ho, He and Rs were 0.350, 0.467 and 2.72, respectively. Global fit to Hardy–Weinberg proportions was observed in 7 of 19 populations. Global estimates of FST revealed significant differentiation among populations. Bayesian analyses of population structure allowed the recognition of two main gene pools (popcorns versus floury landraces). When NWA was added to the analysis, three clusters were distinguished: NEA popcorns, NEA flours and NWA racial complexes. Additional information on the relationships among these groups was retrieved from cluster analyses. This study shows that lowland landraces from Northern Argentina harbour considerable levels of genetic diversity, with contributions from different gene pools. Further studies encompassing a larger number of populations from the NEA region will certainly help to detect additional genetic variation, which may prove highly valuable in germplasm conservation and management. Future conservation efforts should focus on preserving NEA popcorns, NEA floury and NWA racial complexes as different management units.

BROTE DE HISTOPLASMOSIS DE PRIMOINFECCIÓN EN CINCO HERMANAS

Histoplasmosis capsulati is a fungal infection caused by the dimorphic fungus Histoplasma capsulatum var. capsulatum. It is an endemic mycoses which has a wide distribution in North, Central and South America. Primary infection is acquired through the inhalation of the conidial forms of the fungus present in the environment, especially in caves with bat droppings and soil inhabited by chickens. Clinical features of primary infection are unespecific and may vary from asymptomatic to disseminated forms depending on the proportion of conidae inhalated. Here we present an outbreak of Histoplasma capsulatum primary infection affecting five Argentinian sisters, during a car trip to the north of Argentina, which included the provinces of Santiago del Estero and Tucuman. Four of them presented with mild to moderate acute respiratory disease; the other one developed severe and uncommon manifestations such as erythema nodosum and phlyctenular keratoconjunctivitis. All patients achieved a good clinical outcome and none of them required antifungal therapy.

C-Band Radiometric Response to Rainfall Events in the Subtropical Chaco Forest

In this letter, multitemporal signatures collected by Advanced Microwave Scanning Radiometer (AMSR-E) over the dry forest of Chaco, located in North Argentina, are analyzed. The forest has a biomass of about 100 t/ha and a woody volume of about 120 m3/ha. A clear increase of polarization index at C-band is observed after intense rain events in two different locations. Simulations of a discrete model attribute this effect to variations of soil moisture and predict an effect comparable with the measured one. Results indicate that there is a potential to monitor soil moisture variations below dry forests with moderate biomass, also in view of the forthcoming availability of L-band data.

GSK malpractice case raises questions about trial standards

After GlaxoSmithKline (GSK) was fi ned US$92 000 by Argentinian courts for administrative irregularities in a vaccine trial, observers have questioned whether trials are done under the same strict principles all over the world. On Dec 28, 2011, Marcelo Aguinsky, a judge in the province of Mendoza, found GSK guilty of irregularities in obtaining informed consent in a trial assessing the effi cacy and safety of Synfl orix—a vaccine against Streptococcus pneumoniae and acute otitis media caused by non-typeable Haemophilus infl uenzae. Aguinsky fi ned the drug company and the two main investigators, Miguel Tregnaghi and Hector Abate, a total of AR$1 million. GSK is currently appealing the decision. “GSK conducts clinical trials to the same high standards, irrespective of where in the world they are run”, the company said in a statement. The COMPAS trial was done between 2007 and 2008 in rural areas of three provinces in the east and north of Argentina—Mendoza, Santiago del Estero, and San Juan. It involved around 400 health professionals and was originally intended to recruit 17 000 children. Problems in the GSK trial fi rst came to light in 2007, when paediatrician Ana Marchese reported possible irregularities to FeSProSa (Syndicate Federation of Argentinian Health Professionals) after speaking to the trial participants’ families. FeSProSa investigated the accusations and fi led a report to the National Administration of Drugs, Food and Medical Technology (ANMAT) in December, 2007, declaring problems surrounding informed consent. GSK stated that it was the company that had identifi ed the irregularities through self-monitoring and reported them straight to ANMAT. ANMAT undertook an inspection of the procedures and consent forms and found that in some of them, there was reason to believe that the parents of the participants did not fully understand what they were signing and the witnesses were not impartial. Due to these irregularities, the recruitment process was stopped in August, 2008. Roberto Lede, director of Planning and Institutional Relationships of ANMAT, states that “the intervention of the ANMAT was very opportune. The recruitment was stopped in the way it was being carried out and resumed with intensive control. It should be noted that the irregularities only aff ected less than 1% of the subjects.”