Temporal Changes in Forest Contexts at Multiple Extents: Three Decades of Fragmentation in the Gran Chaco (1979-2010), Central Argentina.

PubMed

Frate, Ludovico; Acosta, Alicia T R; Cabido, Marcelo; Hoyos, Laura; Carranza, Maria Laura

2015-01-01

The context in which a forest exists strongly influences its function and sustainability. Unveiling the multi-scale nature of forest fragmentation context is crucial to understand how human activities affect the spatial patterns of forests across a range of scales. However, this issue remains almost unexplored in subtropical ecosystems. In this study, we analyzed temporal changes (1979-2010) in forest contexts in the Argentinean dry Chaco at multiple extents. We classified forests over the last three decades based on forest context amount (Pf) and structural connectivity (Pff), which were measured using a moving window approach fixed at eight different extents (from local, ~ 6 ha, to regional, ~ 8300 ha). Specific multi-scale forest context profiles (for the years 1979 and 2010) were defined by projecting Pf vs. Pff mean values and were compared across spatial extents. The distributions of Pf across scales were described by scalograms and their shapes over time were compared. The amount of agricultural land and rangelands across the scales were also analyzed. The dry Chaco has undergone an intensive process of fragmentation, resulting in a shift from landscapes dominated by forests with gaps of rangelands to landscapes where small forest patches are embedded in agricultural lands. Multi-scale fragmentation analysis depicted landscapes in which local exploitation, which perforates forest cover, occurs alongside extensive forest clearings, reducing forests to small and isolated patches surrounded by agricultural lands. In addition, the temporal diminution of Pf's variability along with the increment of the mean slope of the Pf 's scalograms, indicate a simplification of the spatial pattern of forest over time. The observed changes have most likely been the result of the interplay between human activities and environmental constraints, which have shaped the spatial patterns of forests across scales. Based on our results, strategies for the conservation and sustainable management of the dry Chaco should take into account both the context of each habitat location and the scales over which a forest pattern might be preserved, altered or restored.

Temporal Changes in Forest Contexts at Multiple Extents: Three Decades of Fragmentation in the Gran Chaco (1979-2010), Central Argentina

PubMed Central

Frate, Ludovico; Acosta, Alicia T. R.; Cabido, Marcelo; Hoyos, Laura; Carranza, Maria Laura

2015-01-01

The context in which a forest exists strongly influences its function and sustainability. Unveiling the multi-scale nature of forest fragmentation context is crucial to understand how human activities affect the spatial patterns of forests across a range of scales. However, this issue remains almost unexplored in subtropical ecosystems. In this study, we analyzed temporal changes (1979–2010) in forest contexts in the Argentinean dry Chaco at multiple extents. We classified forests over the last three decades based on forest context amount (P f) and structural connectivity (P ff), which were measured using a moving window approach fixed at eight different extents (from local, ~ 6 ha, to regional, ~ 8300 ha). Specific multi-scale forest context profiles (for the years 1979 and 2010) were defined by projecting P f vs. P ff mean values and were compared across spatial extents. The distributions of P f across scales were described by scalograms and their shapes over time were compared. The amount of agricultural land and rangelands across the scales were also analyzed. The dry Chaco has undergone an intensive process of fragmentation, resulting in a shift from landscapes dominated by forests with gaps of rangelands to landscapes where small forest patches are embedded in agricultural lands. Multi-scale fragmentation analysis depicted landscapes in which local exploitation, which perforates forest cover, occurs alongside extensive forest clearings, reducing forests to small and isolated patches surrounded by agricultural lands. In addition, the temporal diminution of P f’s variability along with the increment of the mean slope of the P f ‘s scalograms, indicate a simplification of the spatial pattern of forest over time. The observed changes have most likely been the result of the interplay between human activities and environmental constraints, which have shaped the spatial patterns of forests across scales. Based on our results, strategies for the conservation and sustainable management of the dry Chaco should take into account both the context of each habitat location and the scales over which a forest pattern might be preserved, altered or restored. PMID:26630387

Temporal distribution of, and effect of anthropic modifications on, phlebotomine populations in the Chaco Bioregion, Argentina.

PubMed

Szelag, E A; Rosa, J R; Quintana, M G; Salomon, O D

2018-06-01

Migonemyia migonei is the predominant species in the dry ecoregion and Nyssomyia neivai in the humid region, although co-dominance in humid highly modified areas could be observed. Vector abundance seems to be modulated by environmental anthropization, as the abundance and predominance of Ny. neiviai and Mg. migonei increased in highly modified areas. In Humid Chaco, the risk of human-vector contact would be present throughout the year, being particularly high in spring/summer, and in Dry Chaco, the risk would be restricted to temperate and humid months. © 2017 The Royal Entomological Society.

Strontium Isotopes and the Reconstruction of the Chaco Regional System: Evaluating Uncertainty with Bayesian Mixing Models

PubMed Central

Drake, Brandon Lee; Wills, Wirt H.; Hamilton, Marian I.; Dorshow, Wetherbee

2014-01-01

Strontium isotope sourcing has become a common and useful method for assigning sources to archaeological artifacts. In Chaco Canyon, an Ancestral Pueblo regional center in New Mexico, previous studies using these methods have suggested that significant portion of maize and wood originate in the Chuska Mountains region, 75 km to the East. In the present manuscript, these results were tested using both frequentist methods (to determine if geochemical sources can truly be differentiated) and Bayesian methods (to address uncertainty in geochemical source attribution). It was found that Chaco Canyon and the Chuska Mountain region are not easily distinguishable based on radiogenic strontium isotope values. The strontium profiles of many geochemical sources in the region overlap, making it difficult to definitively identify any one particular geochemical source for the canyon's pre-historic maize. Bayesian mixing models support the argument that some spruce and fir wood originated in the San Mateo Mountains, but that this cannot explain all 87Sr/86Sr values in Chaco timber. Overall radiogenic strontium isotope data do not clearly identify a single major geochemical source for maize, ponderosa, and most spruce/fir timber. As such, the degree to which Chaco Canyon relied upon outside support for both food and construction material is still ambiguous. PMID:24854352

[Vectorial and congenital transmission of Trypanosoma cruzi in Las Lomitas, Formosa].

PubMed

Sosa-Estani, Sergio; Dri, Lucía; Touris, Cecilia; Abalde, Sergio; Dell'arciprete, Ana; Braunstein, Jose

2009-01-01

Chagas disease, caused by Trypanosoma cruzi, is a major cause of morbidity and mortality in Latin America. The objective of this study was to describe the rate of infestation in four aboriginal communities in Las Lomitas (Great Chaco Region), Formosa, Argentina; the rate of infection in children residing in these communities, in blood donors and in pregnant women who received care at the Hospital Las Lomitas, as well as the rate of congenital infection in children born to women infected during the study period. The rate of infestation of 172 households evaluated in 2006 reached 32%. Prevalence of infection among 445 people was 17.5% and in children under 5 years old it was 8.6%. The rate of infection reached 18.6% in blood donors and 29.1% in pregnant women. The rate of infection among 47 children born to infected women, and living in residences under vectorial surveillance was 17.0%. These infections were considered as congenital. This study showed indexes compatible with active vectorial transmission at the beginning. After vectorial control with insecticides the infestation rate has been reduced to 3.3%. The local health system has introduced high impact procedures of primary and secondary prevention in order to prevent new cases and to treat infected people.

Revisiting human-environment interactions in Chaco Canyon and the American Southwest

USGS Publications Warehouse

Betancourt, Julio L.; Guiterman, Christopher H.

2016-01-01

Chaco Canyon was the center of a regionally integrated system. Despite a century of research, questions remain about its rise and fall, and the role of human-environment interactions. The answers may lie in current events and new tools and perspectives.

Seroprevalence of Hepatitis A Virus, Hepatitis E Virus, and Helicobacter pylori in Rural Communities of the Bolivian Chaco, 2013.

PubMed

Campolmi, Irene; Spinicci, Michele; Mayaregua, David Rojo; Barahona, Herlan Gamboa; Mantella, Antonia; Lara, Yunni; Roselli, Mimmo; Strohmeyer, Marianne; Corti, Giampaolo; Tolari, Francesco; Pinckert, Joaquín Monasterio; Dalton, Harry R; Bartoloni, Alessandro

2018-05-01

In the Bolivian Chaco, south-east of Bolivia, studies conducted over the past three decades reported hepatitis A virus (HAV) and Helicobacter pylori seroprevalences above 90% and 60%, respectively. Hepatitis E virus (HEV) prevalence was previously found to be 6-7% but is probably an underestimate because of the poor sensitivity of the assays used. In November 2013, we conducted a cross-sectional study of 263 healthy volunteers from two rural communities of the Bolivian Chaco, aiming to reassess HAV, HEV, and H. pylori seroprevalence 10-20 years following the previous surveys. Hepatitis A virus seroprevalence was 95%, with universal exposure after the first decade of life; HEV seroprevalence was considerably higher (31-35%) than that previously reported; H. pylori seroprevalence was 59%, with an age-dependent distribution. The high prevalence of these infections suggests that major efforts are still needed to reduce fecal-oral transmission and to improve human health in the Bolivian Chaco.

Environmental, land cover and land use constraints on the distributional patterns of anurans: Leptodacylus species (Anura, Leptodactylidae) from Dry Chaco

PubMed Central

Medina, Regina Gabriela; Aráoz, Ezequiel

2016-01-01

Subtropical dry forests are among the most vulnerable biomes to land transformation at a global scale. Among them, the Dry Chaco suffers an accelerated change due to agriculture expansion and intensification. The Dry Chaco ecoregion is characterized by high levels of endemisms and species diversity, which are the result of a variety of climates and reliefs, allowing a wide variety of environments. The amphibian group exhibits a high richness in the Dry Chaco, which has been barely studied in relation to land cover changes. We used ecological niche models (ENMs) to assess the potential geographic distribution of 10 Leptodactylus species (Anura, Leptodactylidae), which are mainly distributed within the Dry Chaco. We characterized these distributions environmentally, analyzed their overlap with land cover classes, and assessed their diversity of ecoregions. Also, we evaluated how these species potential distribution is affected by the transformation of land, and quantified the proportional area of the potential distribution in protected areas. We found that temperature seasonality is the main constraint to the occurrence of the species studied, whose main habitats are savannas, grasslands and croplands. The main threats to these species are the effects of climate change over spatial patterns of seasonality, which could affect their breeding and reproduction mode; the loss of their natural habitat; the exposure to contaminants used by intensive agriculture and their underrepresentation in protected areas. PMID:27833796

Environmental, land cover and land use constraints on the distributional patterns of anurans: Leptodacylus species (Anura, Leptodactylidae) from Dry Chaco.

PubMed

Medina, Regina Gabriela; Ponssa, Maria Laura; Aráoz, Ezequiel

2016-01-01

Subtropical dry forests are among the most vulnerable biomes to land transformation at a global scale. Among them, the Dry Chaco suffers an accelerated change due to agriculture expansion and intensification. The Dry Chaco ecoregion is characterized by high levels of endemisms and species diversity, which are the result of a variety of climates and reliefs, allowing a wide variety of environments. The amphibian group exhibits a high richness in the Dry Chaco, which has been barely studied in relation to land cover changes. We used ecological niche models (ENMs) to assess the potential geographic distribution of 10 Leptodactylus species (Anura, Leptodactylidae), which are mainly distributed within the Dry Chaco. We characterized these distributions environmentally, analyzed their overlap with land cover classes, and assessed their diversity of ecoregions. Also, we evaluated how these species potential distribution is affected by the transformation of land, and quantified the proportional area of the potential distribution in protected areas. We found that temperature seasonality is the main constraint to the occurrence of the species studied, whose main habitats are savannas, grasslands and croplands. The main threats to these species are the effects of climate change over spatial patterns of seasonality, which could affect their breeding and reproduction mode; the loss of their natural habitat; the exposure to contaminants used by intensive agriculture and their underrepresentation in protected areas.

Range extension of Myotis midastactus​ (Chiroptera, Vespertilionidae) to Paraguay

PubMed Central

Idárraga, Liu; Wilson, Don Ellis

2015-01-01

Abstract Background Myotis midastactus Moratelli and Wilson, 2014 (Vespertilionidae, Myotinae) was described from the Myotis simus Thomas, 1901 complex based on collections from the Bolivian Savannah. New information Four vouchers previously assigned to M. simus from the Alto Chaco in Paraguay (West of the Paraguay River) are reassigned here to M. midastactus. These specimens extend the geographic distribution of M. midastactus 1200 km southward, and constitute the first evidence of the species in the country. Based on other material from the Brazilian Pantanal and Cerrado, Central Paraguay and north-eastern Argentina, we also discuss the identity of simus-like populations south of the Amazon Basin. The status of these populations is still unclear, but the little evidence we have at hand indicates that these populations may represent another taxon—M. guaycuru Proença, 1943; whereas M. simus seems to be restricted to the Amazon basin. This hypothesis is still very speculative and requires further investigation. With the assignment of material from Alto Chaco to M. midastactus, seven species of Myotis are confirmed for Paraguay: M. albescens, M. lavali, M. levis, M. midastactus, M. nigricans, M. riparius, and M. ruber. PMID:26379462

Deforestation of "degraded" rangelands: The Argentine Chaco enters the next stage of the Anthropocene

USDA-ARS?s Scientific Manuscript database

Twenty years ago I completed my Master’s work in the Chaco forests of northern Argentina. The native forests are, in fact, rangelands. In addition to livestock grazing, there is timber extraction, wildlife harvest (think tegu lizard cowboy boots), and charcoal production. I took part in a project co...

[The "Chaco": eatable medicinal clay in the Peruvian highlands and his properties in digestive diseases].

PubMed

Castillo Contreras, Ofelia; Frisancho Velarde, Oscar

2015-01-01

The inhabitants of the peruvian-bolivian plateau consume a natural substance known as "Chaco", widespread since pre-Columbian era and appreciated for its digestive properties. The Chaco is an edible medicinal clay that is used as slurry with water to restrain dyspeptic discomfort or acid-peptic manifestations. In this contribution we present physicochemical aspects of the composition of the Chaco, experimental animal studies that evaluate its antiulcer effect and in vitro test that studies the antacid property. The proposed mechanism of therapeutic action is due to a cytoprotective effect on the gastric mucosa by independent mechanisms of acid secretion inhibition, as it has no antacid property in vitro. Also it has an adsorptivity to different organic molecules due to their large surface area and tetrahedral charge that makes it to interact with polar substances such as water and toxins. The other purpose of this special contribution is to recognize the coexistence of "Traditional Medicine" and "Western Medicine", a situation which leads to the need for preclinical research of various natural resources.

Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest, Part 2: The Chaco Halo, Mesa Verde, Pajarito Plateau/Bandelier, and Zuni Archaeological Regions

USGS Publications Warehouse

Benson, L.V.

2011-01-01

Chemical and nutrient analyses of 471 soil samples from 161 sites within four archaeological regions (Pajarito Plateau/Bandelier, Zuni, Mesa Verde, and the Chaco Halo) were combined with historical climate data in order to evaluate the agricultural productivity of each region. In addition, maize productivity and field-life calculations were performed using organic-nitrogen (N) values from the upper 50 cm of soil in each region and a range (1-3%/year) of N-mineralization rates. The endmember values of this range were assumed representative of dry and wet climate states. With respect to precipitation and heat, the Pajarito Plateau area has excellent agricultural potential; the agricultural potentials of the Zuni and Mesa Verde regions are good; and the agricultural potential of the Chaco Halo is poor. Calculations of N mineralization and field life indicate that Morfield Valley in Mesa Verde should be able to provide 10 bu/ac of maize for decades (without the addition of N) when organic N-mineralization rates exceed 2%. Productivity and field-life potential decrease in the following order: Zuni, Mesa Verde, Bandelier, Chaco Halo. The Chaco Halo is very unproductive; e. g., 10 bushels per acre can be achieved within the Halo only from soils having the highest organic N concentration (third quartile) and which undergo the highest rate (3%) of N mineralization. ?? 2010 US Government.

Prehistoric deforestation at Chaco Canyon?

PubMed Central

Wills, W. H.; Drake, Brandon L.; Dorshow, Wetherbee B.

2014-01-01

Ancient societies are often used to illustrate the potential problems stemming from unsustainable land-use practices because the past seems rife with examples of sociopolitical “collapse” associated with the exhaustion of finite resources. Just as frequently, and typically in response to such presentations, archaeologists and other specialists caution against seeking simple cause-and effect-relationships in the complex data that comprise the archaeological record. In this study we examine the famous case of Chaco Canyon, New Mexico, during the Bonito Phase (ca. AD 860–1140), which has become a prominent popular illustration of ecological and social catastrophe attributed to deforestation. We conclude that there is no substantive evidence for deforestation at Chaco and no obvious indications that the depopulation of the canyon in the 13th century was caused by any specific cultural practices or natural events. Clearly there was a reason why these farming people eventually moved elsewhere, but the archaeological record has not yet produced compelling empirical evidence for what that reason might have been. Until such evidence appears, the legacy of Ancestral Pueblo society in Chaco should not be used as a cautionary story about socioeconomic failures in the modern world. PMID:25071220

Plant antiherbivore defenses in Fabaceae species of the Chaco.

PubMed

Lima, T E; Sartori, A L B; Rodrigues, M L M

2017-01-01

The establishment and maintenance of plant species in the Chaco, one of the widest continuous areas of forests in the South American with sharp climatic variations, are possibly related to biological features favoring plants with particular defenses. This study assesses the physical and chemical defenses mechanisms against herbivores of vegetative and reproductive organs. Its analyses of 12 species of Fabaceae (Leguminosae) collected in remnants of Brazilian Chaco shows that 75% present structural defense characters and 50% have chemical defense - defense proteins in their seeds, like protease inhibitors and lectins. Physical defenses occur mainly on branches (78% of the species), leaves (67%), and reproductive organs (56%). The most common physical characters are trichomes and thorns, whose color represents a cryptic character since it does not contrast with the other plant structures. Defense proteins occur in different concentrations and molecular weight classes in the seeds of most species. Protease inhibitors are reported for the first time in seeds of: Albizia niopoides, Anadenanthera colubrina, Mimosa glutinosa, Prosopis rubriflora, and Poincianella pluviosa. The occurrence of physical and chemical defenses in members of Fabaceae indicate no associations between defense characters in these plant species of the Chaco.

Seroepidemiological trend of strongyloidiasis in the Bolivian Chaco (1987-2013) in the absence of disease-specific control measures.

PubMed

Spinicci, Michele; Macchioni, Fabio; Mantella, Antonia; Gabrielli, Simona; Roselli, Mimmo; Rojo Mayaregua, David; Monasterio Pinckert, Joaquín; Gamboa Barahona, Herlan; Paredes, Grover Adolfo; Halkyer, Percy; Cancrini, Gabriella; Olliaro, Piero; Montresor, Antonio; Bartoloni, Alessandro

2017-11-01

The prevalence of Strongyloides stercoralis infections is grossly underestimated because infections go mostly undetected, although they can persist for a lifetime due to the auto-infective cycle. In the Bolivian Chaco, the prevalence of soil-transmitted nematodes dropped dramatically in the past 25 years, but the mebendazole used for preventive chemotherapy has no effect on S. stercoralis. Meanwhile, the prevalence of intestinal protozoan infections remains unchanged. We compared S. stercoralis seroprevalence in rural communities of the Bolivian Chaco from 1987 to 2013. Sera collected during two previous serosurveys, conducted in the Chaco region in 1987 and 2013, were tested for S. stercoralis using a commercial assay (Bordier-ELISA, Bordier Affinity Products, Switzerland). Overall, 355 sera were analysed, 122 from the 1987 survey and 233 from the 2013 survey. Seropositivity for S. stercoralis was significantly more prevalent in 1987 (19/122, 16% in 1987 vs. 15/233, 6% in 2013, P = 0.006), accounted for by a drop from 17% to 3% in people under 26 years of age. Multivariate analysis showed a significant association between seropositivity for S. stercoralis and age in the 2013 population (OR 1.03 for each one-year increase, 95%CI 1.00-1.05, P = 0.04), but none in 1987. The significant reduction in S. stercoralis seroprevalence in Bolivian Chaco cannot be explained by preventive chemotherapy or improved social-sanitary conditions. As the drop is seen in younger generations, it is consistent with little transmission occurring. However, the risk of transmission still exists, as prevalence is persistently high in older individuals, who present a potential reservoir due to the lifelong nature of S. stercoralis infections. © 2017 John Wiley & Sons Ltd.

Kdr mutations in Triatoma infestans from the Gran Chaco are distributed in two differentiated foci: Implications for pyrethroid resistance management.

PubMed

Sierra, Ivana; Capriotti, Natalia; Fronza, Georgina; Mougabure-Cueto, Gastón; Ons, Sheila

2016-06-01

Point mutations in the voltage-gated sodium channel, the primary target of pyrethroid insecticides, have been associated with the resistance in Triatoma infestans, an important vector of Chagas' disease. Hence, the sustainability of vector control programs requires the implementation of resistance management strategies. We determined the sensitivity of the molecular assays previously designed for early resistance detection to be used in pooled samples from a wide area of the endemic region, and validated them for their routine use in control campaigns for the monitoring of insecticide resistance in T. infestans. Consequently, we used these methods to examine the distribution of resistance-associated mutations in the sodium channel gene in populations of T. infestans from the Argentinean and Bolivian Gran Chaco. The PASA and REA assays tested proved sensitive enough to detect kdr SNPs in pooled samples, indicating these assays are suitable for routine screening in insecticide resistance surveillance. Two geographically differentiated foci were detected in T. infestans populations from the Argentinean and Bolivian Gran Chaco, with populations on the Bolivian-Argentinean border carrying L1014F mutation, and those from the Argentinean Chaco carrying L925I mutation. In all highly resistant populations analyzed, one of both kdr mutations was present, and toxicological assays determined that all pyrethroid resistant populations analyzed herein were sensitive to fenitrothion. The principal cause of pyrethroid resistance in T. infestans from the Gran Chaco ecoregion is kdr mutations in the sodium channel. Different levels of resistance occur in different populations carrying identical mutation, suggesting the existence of contributory mechanisms. Copyright © 2016 Elsevier B.V. All rights reserved.

Gods, Demons and Deceivers: Jesuits Facing Chaco Skies

NASA Astrophysics Data System (ADS)

López, Alejandro Martín

2015-05-01

The Jesuit missions located in the Chaco are less known than the ones in Paraguay. They are the last step of the Jesuits' missionary device in the Rio de la Plata region. They were dedicated to 'evangelize' and 'civilize' the aboriginal groups considered more hostile: nomadic hunter-gatherers who adopted the use of horses and were not controlled by the colonial government. These groups were seen by Europeans as a radical otherness. That is why the Jesuits' descriptions of Chaco Indian skies are a very interesting example about European attitudes toward other worldviews. This paper explores the use of different paradigms for interpreting these alternative skies: demonic influence, the deception of sorcerers and an Evemeristic reading of the indigenous worldview. This article also addresses some of the interactions between the aboriginal and Christian skies in the mission context.

Early procurement of scarlet macaws and the emergence of social complexity in Chaco Canyon, NM.

PubMed

Watson, Adam S; Plog, Stephen; Culleton, Brendan J; Gilman, Patricia A; LeBlanc, Steven A; Whiteley, Peter M; Claramunt, Santiago; Kennett, Douglas J

2015-07-07

High-precision accelerator mass spectrometer (AMS) (14)C dates of scarlet macaw (Ara macao) skeletal remains provide the first direct evidence from Chaco Canyon in northwestern New Mexico that these Neotropical birds were procured from Mesoamerica by Pueblo people as early as ∼ A.D. 900-975. Chaco was a prominent prehistoric Pueblo center with a dense concentration of multistoried great houses constructed from the 9th through early 12th centuries. At the best known great house of Pueblo Bonito, unusual burial crypts and significant quantities of exotic and symbolically important materials, including scarlet macaws, turquoise, marine shell, and cacao, suggest societal complexity unprecedented elsewhere in the Puebloan world. Scarlet macaws are known markers of social and political status among the Pueblos. New AMS (14)C-dated scarlet macaw remains from Pueblo Bonito demonstrate that these birds were acquired persistently from Mesoamerica between A.D. 900 and 1150. Most of the macaws date before the hypothesized apogeal Chacoan period (A.D. 1040-1110) to which they are commonly attributed. The 10th century acquisition of these birds is consistent with the hypothesis that more formalized status hierarchies developed with significant connections to Mesoamerica before the post-A.D. 1040 architectural florescence in Chaco Canyon.

Early procurement of scarlet macaws and the emergence of social complexity in Chaco Canyon, NM

PubMed Central

Watson, Adam S.; Plog, Stephen; Culleton, Brendan J.; Gilman, Patricia A.; LeBlanc, Steven A.; Whiteley, Peter M.; Claramunt, Santiago; Kennett, Douglas J.

2015-01-01

High-precision accelerator mass spectrometer (AMS) 14C dates of scarlet macaw (Ara macao) skeletal remains provide the first direct evidence from Chaco Canyon in northwestern New Mexico that these Neotropical birds were procured from Mesoamerica by Pueblo people as early as ∼A.D. 900–975. Chaco was a prominent prehistoric Pueblo center with a dense concentration of multistoried great houses constructed from the 9th through early 12th centuries. At the best known great house of Pueblo Bonito, unusual burial crypts and significant quantities of exotic and symbolically important materials, including scarlet macaws, turquoise, marine shell, and cacao, suggest societal complexity unprecedented elsewhere in the Puebloan world. Scarlet macaws are known markers of social and political status among the Pueblos. New AMS 14C-dated scarlet macaw remains from Pueblo Bonito demonstrate that these birds were acquired persistently from Mesoamerica between A.D. 900 and 1150. Most of the macaws date before the hypothesized apogeal Chacoan period (A.D. 1040–1110) to which they are commonly attributed. The 10th century acquisition of these birds is consistent with the hypothesis that more formalized status hierarchies developed with significant connections to Mesoamerica before the post-A.D. 1040 architectural florescence in Chaco Canyon. PMID:26100874

Natural contamination with arsenic and other trace elements in groundwater of the Central-West region of Chaco, Argentina.

PubMed

Blanes, Patricia S; Buchhamer, Edgar E; Giménez, María C

2011-01-01

This study covered the central agricultural region of the Chaco province, which lacks a permanent river networks. However, during the rainy period there is localized groundwater recharge. About 84 groundwater samples were taken during the period April-December 2007. These groundwater samples were collected from two different depths: 62 samples from shallow wells (4 to 20 m) and 24 samples from deep wells (20 to 100 m). Chemical variables were determined: pH, specific conductance, total dissolved solid, hardness, alkalinity, HCO(3)-, CO(3)(2-), SO(4)(2-), Cl-, NO(3)-, NO(2) -, NH(4)+, F-, As((tot)), Na+, K+, Ca2+, Mg2+, Fe, Cu, Ni, Pb and Zn. The chemical composition of groundwater in the study area is dominantly sodium bicarbonate and sodium chloride bicarbonate, comprising more than 60% (52/86) of shallow and deep groundwater samples. Of the 86 analyzed groundwater samples, 88% exceeded the WHO (World Health Organization) and CAA (Código Alimentario Argentino) standards (10 μg/L) for As (arsenic) and 9% exceeded the WHO standard (1.5 mg/L) for F(-).Groundwater highly contaminated with As (max. 1,073 μg/L) and F- (max. 4.2 mg/L) was found in shallow aquifer. The contaminated groundwater is characterized by high pH (max. 8.9), alkalinity (max. HCO(3)- 1,932 mg/L), SO(4)(2-) (max. 11,862 mg/L), Na(+) (max. 3,158 mg/L), Cl(-) (max. 10,493 mg/L) and electric conductivity greater than 33.3 μS/cm. Other associated elements (Ni, Pb, Cu and Zn) are present in low concentrations, except for Fe that in 32% of samples exceeded the guideline value of 0.3 mg/L suggested by the CAA.

The presence of species of Pseudochironomus Malloch 1915 (Diptera: Chironomidae) in watercourses of Chaco Serrano Ecoregion (Argentina, South America).

PubMed

Paggi, Analía C; Rodriguez Garay, Gretel N

2015-05-15

Male imagos of Pseudochironomus viridis (Kieffer) are redescribed, the immature stages are described and figured for the first time. During this study, larva and pupal exuviae associated to P. richardsoni (Malloch) were recorded for the first time for South America. The specimens were collected from a stream and a river in the Pampasic Hills System in the Chaco Serrano ecoregion of Argentina.

Soil analysis in discussions of agricultural feasibility for ancient civilizations: A critical review and reanalysis of the data and debate from Chaco Canyon, New Mexico.

PubMed

McCool, Jon-Paul P; Fladd, Samantha G; Scarborough, Vernon L; Plog, Stephen; Dunning, Nicholas P; Owen, Lewis A; Watson, Adam S; Bishop, Katelyn J; Crowley, Brooke E; Haussner, Elizabeth A; Tankersley, Kenneth B; Lentz, David; Carr, Christopher; Thress, Jessica L

2018-01-01

Questions about how archaeological populations obtained basic food supplies are often difficult to answer. The application of specialist techniques from non-archaeological fields typically expands our knowledge base, but can be detrimental to cultural interpretations if employed incorrectly, resulting in problematic datasets and erroneous conclusions not easily caught by the recipient archaeological community. One area where this problem has failed to find resolution is Chaco Canyon, New Mexico, the center of one of the New World's most vibrant ancient civilizations. Discussions of agricultural feasibility and its impact on local population levels at Chaco Canyon have been heavily influenced by studies of soil salinity. A number of researchers have argued that salinized soils severely limited local agricultural production, instead suggesting food was imported from distant sources, specifically the Chuska Mountains. A careful reassessment of existing salinity data as measured by electrical conductivity reveals critical errors in data conversion and presentation that have misrepresented the character of the area's soil and its potential impact on crops. We combine all available electrical conductivity data, including our own, and apply multiple established conversion methods in order to estimate soil salinity values and evaluate their relationship to agricultural productivity potential. Our results show that Chacoan soils display the same salinity ranges and spatial variability as soils in other documented, productive fields in semi-arid areas. Additionally, the proposed large-scale importation of food from the Chuska Mountains region has serious social implications that have not been thoroughly explored. We consider these factors and conclude that the high cost and extreme inflexibility of such a system, in combination with material evidence for local agriculture within Chaco Canyon, make this scenario highly unlikely. Both the soil salinity and archaeological data suggest that there is no justification for precluding the practice of local agriculture within Chaco Canyon.

Lama guanicoe remains from the Chaco ecoregion (Córdoba, Argentina): An osteological approach to the characterization of a relict wild population

PubMed Central

Barri, Fernando

2018-01-01

Guanacos (Lama guanicoe) are large ungulates that have been valued by human populations in South America since the Late Pleistocene. Even though they were very abundant until the end of the 19th century (before the high deforestation rate of the last decades), guanacos have nearly disappeared in the Gran Chaco ecoregion, with relicts and isolated populations surviving in some areas, such as the shrubland area near the saline depressions of Córdoba province, Argentina. In this report, we present the first data from a locally endangered guanaco wild population, through the study of skeletal remains recovered in La Providencia ranch. Our results showed that most of the elements belonged to adults aged between 36 and 96 months; sex evaluation showed similar numbers of males and females. Statistical analysis of the body size of modern samples from Córdoba demonstrated that guanacos from the Chaco had large dimensions and presented lower size variability than the modern and archaeological specimens in our database. Moreover, they exhibited dimensions similar to those of modern guanacos from Patagonia and San Juan, and to archaeological specimens from Ongamira and Cerro Colorado, although further genetic studies are needed to corroborate a possible phylogenetic relationship. Finally, we used archaeozoological techniques to provide a first characterization of a relict guanaco population from the Chaco ecoregion, demonstrating its value to the study of modern skeletal remains and species conservation biology. PMID:29641579

Land-Use Planning in the Chaco Plain (Burruyacú, Argentina): Part 2: Generating a Consensus Plan to Mitigate Land-Use Conflicts and Minimize Land Degradation

NASA Astrophysics Data System (ADS)

Recatalá Boix, Luis; Zinck, Joseph Alfred

2008-08-01

The Burruyacú district (Tucumán province, Northwest Argentina) has been traditionally an area with rural activities based on the exploitation of the Chaco forest for timber and livestock browsing. Since the 1960s, local institutions started promoting soybean due to favorable land conditions and good market prices. Soybean extension, as from the 1970s, has resulted in important reduction of the Chaco forest and also caused physical soil degradation, especially soil compaction and erosion. A land-use-planning exercise was carried out using the Land-Use Planning and Information System (LUPIS) as a spatial decision support system. LUPIS facilitates the generation of alternative land-use plans by adjusting the relative importance attributed by multiple stakeholders to preference and avoidance policies. The system leads to the allocation of competing land uses to land map units in accordance with their preferred resource requirements, conditional upon the resource base of the area and the stakeholders’ demands. After generating a land use plan for each stakeholder category identified in the study area, including commercial farmers, conservative/conventional farmers, and conservationists, a consensus plan was established to address the land-use conflicts between mechanized agriculture, traditional agriculture and forest conservation, and to mitigate soil degradation caused by extensive dry-farming. Although the planning exercise did not directly involve the stakeholders, the results are sufficiently practical and realistic to suggest that the approach could be extended to the entire Chaco plain region.

Scaling down of a deworming programme among school-age children after a thirty-year successful intervention in the Bolivian Chaco.

PubMed

Spinicci, Michele; Macchioni, Fabio; Rojo, David; Gamboa, Herlan; Villagrán, Ana Liz; Vallejos, Yolanda; Strohmeyer, Marianne; Roselli, Mimmo; Gabrielli, Simona; Cancrini, Gabriella; Monasterio, Joaquín; Castellanos, Paul; Paredes, Grover Adolfo; Maury, Sdenka; Zárate, Adolfo; Rocabado, Rodolfo; Olliaro, Piero; Montresor, Antonio; Bartoloni, Alessandro

2018-04-16

Preventive chemotherapy is the WHO-recommended control method for soil-transmitted helminthiases. In the Bolivian Chaco, 6-monthly single-dose mebendazole delivery to school-age children achieved a dramatic decrease in soil-transmitted helminthiases prevalence between 1987 and 2013. Consequently, in September 2016, preventive chemotherapy delivery was interrupted in nine rural communities. In compliance with WHO recommendations, we intensified surveillance to monitor soil-transmitted helminthiases prevalence and detect potential changes that would require interventions. We conducted two cross-sectional parasitology surveys 12 months apart (September 2016-2017) among school-age children living in the communities where preventive chemotherapy delivery had been halted. Study design, methods of sampling and sample analysis technique (direct microscopy, Kato-Katz technique) followed WHO recommendations, aiming to obtain data representative of the Bolivian Chaco ecological zone. We collected 426 samples in 2016 and 520 in 2017. Soil-transmitted helminthiasis prevalence was unremarkable: 0.7% (95% CI 0-1.5%) in 2016 and 0.8% (0-1.5%) in 2017. Conversely, the prevalence of tapeworms (13% in 2016, 12% in 2017) and intestinal protozoan infections (81% in 2016 and 75% in 2017) continued to be high. Our findings support the role of preventive chemotherapy in reducing soil-transmitted helminthiases transmission, as otherwise poor hygienic and health conditions persist in the Bolivian Chaco. A national survey, involving areas from all the ecological zones of Bolivia, is now warranted. © 2018 John Wiley & Sons Ltd.

Trypanosoma cruzi diversity in the Gran Chaco: mixed infections and differential host distribution of TcV and TcVI.

PubMed

Monje-Rumi, María M; Brandán, Cecilia Pérez; Ragone, Paula G; Tomasini, Nicolás; Lauthier, Juan J; Alberti D'Amato, Anahí M; Cimino, Rubén O; Orellana, Viviana; Basombrío, Miguel A; Diosque, Patricio

2015-01-01

The transmission cycles of Trypanosoma cruzi in the Gran Chaco are complex networks involving domestic and wild components, whose interrelationships are not well understood. Knowing the circuit of transmission of the different Discrete Typing Units (DTUs) of T. cruzi in the complex environment of the Chaco region is relevant to understanding how the different components (reservoirs, vectors, ecotopes) interact. In the present study we identified the DTUs infecting humans and dogs in two rural areas of the Gran Chaco in Argentina, using molecular methods which avoid parasite culture. Blood samples of humans and dogs were typified by PCR-DNA blotting and hybridization assays with five specific DNA probes (TcI, TcII, TcIII, TcV and TcVI). PCR analyses were performed on seropositive human and dog samples and showed the presence of T. cruzi DNA in 41.7% (98/235) and 53% (35/66) samples, respectively. The identification of infective DTUs was determined in 83.6% (82/98) and 91.4% (32/35) in human and dog samples, respectively. Single infections (36.7% - 36/98) and a previously not detected high proportion of mixed infections (47.9% - 47/98) were found. In a 15.3% (15/98) of samples the infecting DTU was not identified. Among the single infections TcV was the most prevalent DTU (30.6% - 30/98) in human samples; while TcVI (42.8% - 15/35) showed the highest prevalence in dog samples. TcV/TcVI was the most prevalent mixed infection in humans (32.6% - 32/98); and TcI/TcVI (14.3% - 5/35) in dogs. Significant associations between TcV with humans and TcVI with dogs were detected. For the first time, the presence of TcIII was detected in humans from this region. The occurrence of one human infected whit TcIII (a principally wild DTU) could be suggested the emergence of this, in domestic cycles in the Gran Chaco. Copyright © 2014 Elsevier B.V. All rights reserved.

Predominance of hybrid discrete typing units of Trypanosoma cruzi in domestic Triatoma infestans from the Bolivian Gran Chaco region.

PubMed

Perez, Esdenka; Monje, Marcelo; Chang, Boris; Buitrago, Rosio; Parrado, Rudy; Barnabé, Christian; Noireau, François; Brenière, Simone Frédérique

2013-01-01

In the Gran Chaco region the reinfestation by Triatoma infestans remains a major problem for control of Chagas disease. Trypanosoma cruzi the agent of the illness presents a broad genetic intraspecific variability which is poorly documented in the Bolivian Gran Chaco. This work presents the identification of the discrete typing units (DTUs) currently recognized for T. cruzi in T. infestans populations collected before and after residual insecticide spraying in four villages in this region. Before spraying, of 84 samples, the frequencies of the DTUs identified by using the multiplex PCR based on the non transcribed spacer of the mini-exon gene (MMPCR) were 0.21 for TcI, 0.70 for TcII/TcV/TcVI, and 0.17 for TcIII/TcIV and no significant difference was observed after spraying (76 samples). Moreover 13% of the total sample corresponds to T. infestans specimens with mixed infection of DTUs of which three were TcII/TcV/TcVI with TcIII/TcIV. The partial sequences of T. cruzi Gpi gene obtained from 14 PCR products agree the MMPCR DTU identification and allowed to precise the occurrence of TcIII, TcII and hybrid TcV/TcVI stocks which were not discriminated by the MMPCR. Given the high prevalence of hybrid stocks, the authors ask whether the recombination event at the origin of hybrids would have taken place in the Gran Chaco where the putative parents are also present. Copyright © 2012 Elsevier B.V. All rights reserved.

A Microsatellite-Based Analysis of House Infestation With Triatoma Infestans (Hemiptera: Reduviidae) After Insecticide Spraying in the Argentine Chaco.

PubMed

Piccinali, Romina V; Gaunt, Michael W; Gürtler, Ricardo E

2018-05-04

Prevention of vector-borne transmission of Chagas disease mainly relies on residual insecticide spraying. Despite significant success at a regional scale, house infestation with Triatoma infestans (Klug) (Hemiptera: Reduviidae) still persists in the Gran Chaco ecoregion. One key aspect is the identification of the sources of reinfestant triatomines. After detecting fine-scale genetic structure in two rural villages of Pampa del Indio, Argentine Chaco, we tested hypotheses on the putative origins of the triatomines collected at 4, 8, and 12 mo after insecticide house spraying. We genotyped 10 microsatellite loci in 262 baseline and 83 postspraying triatomines from different houses. Genetic variability was similar between baseline and postspraying populations, but 13 low-frequency alleles were not detected at postspraying. FSTs were not significant between insects collected before and after insecticide spraying at the same house in all but one case, and they clustered together in a neighbor-joining tree. A clustering algorithm detected seven genetic groups, four of them mainly composed of baseline and postspraying insects from the same house. Assignment tests suggested multiple putative sources (including the house of collection) for most postspraying insects but excluded a house located more than 9 km from the study area. The origin of three triatomines was attributed to immigration from other unaccounted sources. Our study is compatible with the hypothesis that house reinfestations in the Argentine Chaco are mostly related to residual foci (i.e., survival of insects within the same community), in agreement with field observations, spatial analysis, and morphometric studies previously published.

Changes in Species Richness and Composition of Tiger Moths (Lepidoptera: Erebidae: Arctiinae) among Three Neotropical Ecoregions.

PubMed

Beccacece, Hernán Mario; Zeballos, Sebastián Rodolfo; Zapata, Adriana Inés

Paraná, Yungas and Chaco Serrano ecoregions are among the most species-rich terrestrial habitats at higher latitude. However, the information for tiger moths, one of the most speciose groups of moths, is unknown in these ecoregions. In this study, we assess their species richness and composition in all three of these ecoregions. Also we investigated whether the species composition of tiger moths is influenced by climatic factors and altitude. Tiger moth species were obtained with samples from 71 sites using standardized protocols (21 sites were in Yungas, 19 in Paraná and 31 in Chaco Serrano). Rarefaction-extrapolation curves, non-parametric estimators for incidence and sample coverage indices were performed to assess species richness in the ecoregions studied. Non metric multidimensional scaling and adonis tests were performed to compare the species composition of tiger moths among ecoregions. Permutest analysis and Pearson correlation were used to evaluate the relationship among species composition and annual mean temperature, annual temperature range, annual precipitation, precipitation seasonality and altitude. Among ecoregions Paraná was the richest with 125 species, followed by Yungas with 63 species and Chaco Serrano with 24 species. Species composition differed among these ecoregions, although Yungas and Chaco Serrano were more similar than Paraná. Species composition was significantly influenced by climatic factors and altitude. This study showed that species richness and species composition of tiger moths differed among the three ecoregions assessed. Furthermore, not only climatic factors and altitude influence the species composition of tiger moths among ecoregions, but also climatic seasonality at higher latitude in Neotropical South America becomes an important factor.

L925I mutation in the Para-type sodium channel is associated with pyrethroid resistance in Triatoma infestans from the Gran Chaco region.

PubMed

Capriotti, Natalia; Mougabure-Cueto, Gastón; Rivera-Pomar, Rolando; Ons, Sheila

2014-01-01

Chagas' disease is an important public health concern in Latin America. Despite intensive vector control efforts using pyrethroid insecticides, the elimination of Triatoma infestans has failed in the Gran Chaco, an ecoregion that extends over Argentina, Paraguay, Bolivia and Brazil. The voltage-gated sodium channel is the target site of pyrethroid insecticides. Point mutations in domain II region of the channel have been implicated in pyrethroid resistance of several insect species. In the present paper, we identify L925I, a new pyrethroid resistance-conferring mutation in T. infestans. This mutation has been found only in hemipterans. In T. infestans, L925I mutation occurs in a resistant population from the Gran Chaco region and is associated with inefficiency in the control campaigns. We also describe a method to detect L925I mutation in individuals from the field. The findings have important implications in the implementation of strategies for resistance management and in the rational design of campaigns for the control of Chagas' disease transmission.

L925I Mutation in the Para-Type Sodium Channel Is Associated with Pyrethroid Resistance in Triatoma infestans from the Gran Chaco Region

PubMed Central

Capriotti, Natalia; Mougabure-Cueto, Gastón; Rivera-Pomar, Rolando; Ons, Sheila

2014-01-01

Background Chagas' disease is an important public health concern in Latin America. Despite intensive vector control efforts using pyrethroid insecticides, the elimination of Triatoma infestans has failed in the Gran Chaco, an ecoregion that extends over Argentina, Paraguay, Bolivia and Brazil. The voltage-gated sodium channel is the target site of pyrethroid insecticides. Point mutations in domain II region of the channel have been implicated in pyrethroid resistance of several insect species. Methods and Findings In the present paper, we identify L925I, a new pyrethroid resistance-conferring mutation in T. infestans. This mutation has been found only in hemipterans. In T. infestans, L925I mutation occurs in a resistant population from the Gran Chaco region and is associated with inefficiency in the control campaigns. We also describe a method to detect L925I mutation in individuals from the field. Conclusions and Significance The findings have important implications in the implementation of strategies for resistance management and in the rational design of campaigns for the control of Chagas' disease transmission. PMID:24466362

Sarcoptic mange in free-ranging pampas foxes in the Gran Chaco, Bolivia.

PubMed

Deem, Sharon L; Noss, Andrew J; Cuéllar, Rosa Leny; Villarroel, Richard; Linn, Michael J; Forrester, Donald J

2002-07-01

Sarcoptes scabiei infestation was diagnosed in two freshly dead free-ranging pampas foxes (Pseudalopex gymnocercus) in the Gran Chaco, Bolivia. Diagnosis was made based on histologic evaluation of skin biopsies and identification of the parasite from skin scrapings. Characteristic gross lesions consistent with mange were noted in 19 of 94 observations of free-ranging pampas foxes in the region from December 1998 to January 2000. None of 16 crab-eating foxes (Cerdocyon thous) observed during the same time period had visible lesions consistent with scabies. These are the first case reports of S. scabiei in pampas foxes.

Central Andes mountains, Chile/Argentina as seen from STS-67

NASA Technical Reports Server (NTRS)

1995-01-01

The Chilean coastline and the arid Atacama Desert stretch the length of the view with the high Andes on the eastern margin where hundreds of volcanoes dot the landscape. The wider (250-350 kilometers) Altiplano ('plains') sector of the Andes appears in the top half of the view, and the narrow (120 kilometers) 'mountain-chain-dominated' sector to the bottom. The northern half of Chile can be seen, with the 'hammer-head' peninsula at the city of Antofagasta, top left. Up welling of cold water as the Humboldt Current immediately offshore gives rise to low stratus cloud. The extensive cloud mass on the right lies beyond the Andes in the low country of Argentina's 'pampas' grasslands and Chaco semi-desert.

Changes in Species Richness and Composition of Tiger Moths (Lepidoptera: Erebidae: Arctiinae) among Three Neotropical Ecoregions

PubMed Central

Beccacece, Hernán Mario; Zeballos, Sebastián Rodolfo; Zapata, Adriana Inés

2016-01-01

Paraná, Yungas and Chaco Serrano ecoregions are among the most species-rich terrestrial habitats at higher latitude. However, the information for tiger moths, one of the most speciose groups of moths, is unknown in these ecoregions. In this study, we assess their species richness and composition in all three of these ecoregions. Also we investigated whether the species composition of tiger moths is influenced by climatic factors and altitude. Tiger moth species were obtained with samples from 71 sites using standardized protocols (21 sites were in Yungas, 19 in Paraná and 31 in Chaco Serrano). Rarefaction-extrapolation curves, non-parametric estimators for incidence and sample coverage indices were performed to assess species richness in the ecoregions studied. Non metric multidimensional scaling and adonis tests were performed to compare the species composition of tiger moths among ecoregions. Permutest analysis and Pearson correlation were used to evaluate the relationship among species composition and annual mean temperature, annual temperature range, annual precipitation, precipitation seasonality and altitude. Among ecoregions Paraná was the richest with 125 species, followed by Yungas with 63 species and Chaco Serrano with 24 species. Species composition differed among these ecoregions, although Yungas and Chaco Serrano were more similar than Paraná. Species composition was significantly influenced by climatic factors and altitude. This study showed that species richness and species composition of tiger moths differed among the three ecoregions assessed. Furthermore, not only climatic factors and altitude influence the species composition of tiger moths among ecoregions, but also climatic seasonality at higher latitude in Neotropical South America becomes an important factor. PMID:27681478

Chaco astronomies

NASA Astrophysics Data System (ADS)

Martín López, Alejandro

2015-08-01

This presentation discusses the result of 18 years of ethnographic and ethnohistorical studies on Chaco astronomies. The main features of the systems of astronomical knowledge of the Chaco Aboriginal groups will be discussed. In particular we will discuss the relevance of the Milky Way, the role of the visibility of the Pleiades, the ways in which the celestial space is represented, the constitution of astronomical orientations in geographic space, etc. We also address a key feature of their vision of the cosmos: the universe is seen by these groups as a socio-cosmos, where humans and non-humans are related. These are therefore actually socio-cosmologies. We will link this to the theories of Chaco Aboriginal groups about power and political relations.We will discuss how the study of Aboriginal astronomies must be performed along with the studies about astronomies of Creole people and European migrants, as well as anthropological studies about the science teaching in the formal education system and by the mass media. In this form we will discuss the relevance of a very complex system of interethnic relations for the conformation of these astronomical representations and practices.We will also discuss the general methodological implications of this case for the ethnoastronomy studies. In particular we will talk about the advantages of a study of regional scope and about the key importance of put in contact the ethnoastronomy with contemporary issues in social sciences.We also analyze the importance of ethnoastronomy studies in relation to studies of sociology of science, especially astronomy. We also study the potential impact on improving formal and informal science curricula and in shaping effective policies to protect the tangible and intangible astronomical heritage in a context of respect for the rights of Aboriginal groups.

Carbon emissions from agricultural expansion and intensification in the Chaco.

PubMed

Baumann, Matthias; Gasparri, Ignacio; Piquer-Rodríguez, María; Gavier Pizarro, Gregorio; Griffiths, Patrick; Hostert, Patrick; Kuemmerle, Tobias

2017-05-01

Carbon emissions from land-use changes in tropical dry forest systems are poorly understood, although they are likely globally significant. The South American Chaco has recently emerged as a hot spot of agricultural expansion and intensification, as cattle ranching and soybean cultivation expand into forests, and as soybean cultivation replaces grazing lands. Still, our knowledge of the rates and spatial patterns of these land-use changes and how they affected carbon emissions remains partial. We used the Landsat satellite image archive to reconstruct land-use change over the past 30 years and applied a carbon bookkeeping model to quantify how these changes affected carbon budgets. Between 1985 and 2013, more than 142 000 km 2 of the Chaco's forests, equaling 20% of all forest, was replaced by croplands (38.9%) or grazing lands (61.1%). Of those grazing lands that existed in 1985, about 40% were subsequently converted to cropland. These land-use changes resulted in substantial carbon emissions, totaling 824 Tg C between 1985 and 2013, and 46.2 Tg C for 2013 alone. The majority of these emissions came from forest-to-grazing-land conversions (68%), but post-deforestation land-use change triggered an additional 52.6 Tg C. Although tropical dry forests are less carbon-dense than moist tropical forests, carbon emissions from land-use change in the Chaco were similar in magnitude to those from other major tropical deforestation frontiers. Our study thus highlights the urgent need for an improved monitoring of the often overlooked tropical dry forests and savannas, and more broadly speaking the value of the Landsat image archive for quantifying carbon fluxes from land change. © 2016 John Wiley & Sons Ltd.

The niche and phylogeography of a passerine reveal the history of biological diversification between the Andean and the Atlantic forests.

PubMed

Trujillo-Arias, Natalia; Dantas, Gisele P M; Arbeláez-Cortés, Enrique; Naoki, Kazuya; Gómez, Maria I; Santos, Fabricio R; Miyaki, Cristina Y; Aleixo, Alexandre; Tubaro, Pablo L; Cabanne, Gustavo S

2017-07-01

The Atlantic Forest is separated from the Andean tropical forest by dry and open vegetation biomes (Chaco and Cerrado). Despite this isolation, both rainforests share closely related lineages, which suggest a past connection. This connection could have been important for forest taxa evolution. In this study, we used the Saffron-billed Sparrow (Arremon flavirostris) as a model to evaluate whether the Andean and the Atlantic forests act as a refugia system, as well as to test for a history of biogeographic connection between them. In addition, we evaluated the molecular systematic of intraspecific lineages of the studied species. We modeled the current and past distribution of A. flavirostris, performed phylogeographic analyses based on mitochondrial and nuclear genes, and used Approximate Bayesian Computation (ABC) analyses to test for biogeographic scenarios. The major phylogeographic disjunction within A. flavirostris was found between the Andean and the Atlantic forests, with a divergence that occurred during the Mid-Pleistocene. Our paleodistribution models indicated a connection between these forest domains in different periods and through both the Chaco and Cerrado. Additionally, the phylogeographic and ABC analyses supported that the Cerrado was the main route of connection between these rainforests, but without giving decisive evidence against a Chaco connection. Our study with A. flavirostris suggest that the biodiversity of the Andean and of the Atlantic forests could have been impacted (and perhaps enriched?) by cycles of connections through the Cerrado and Chaco. This recurrent cycle of connection between the Andean and the Atlantic Forest could have been important for the evolution of Neotropical forest taxa. In addition, we discussed taxonomic implications of the results and proposed to split the studied taxon into two full species. Copyright © 2017 Elsevier Inc. All rights reserved.

First Finding of Melanic Sylvatic Triatoma infestans (Hemiptera: Reduviidae) Colonies in the Argentine Chaco

PubMed Central

CEBALLOS, L. A.; PICCINALI, R. V.; BERKUNSKY, I.; KITRON, U.; GÜRTLER, R. E.

2009-01-01

Triatoma infestans (Klug), the most important vector of Chagas disease in southern South America, is a highly domiciliated species with well-known sylvatic foci only in the Bolivian Andean valleys and in the Bolivian Chaco, where melanic insects designated as “dark morphs” were found. After the tentative identification of two melanic bugs collected from parrot nests in a forest reserve in the Argentine Chaco as T. infestans, we conducted an intensive search there using mouse-baited sticky traps in summer 2006 and 2007. Four live T. infestans bugs were collected in trees without parrot nests in 288 trap-nights, whereas no bug was collected from inside trees with active parrot nests in 51 trap-nights. To increase bug captures, hollow tree trunks that recently had had Amazona aestiva (Berlepsch) and Aratinga acuticaudata (Vieillot) parrot nests were treated with insecticide fumigant canisters exhibiting strong knockdown power. Four (22%) of 18 trees were positive for T. infestans with a dark phenotype. A fragment of the mitochondrial gene COI of 8 of the 14 triatomine bugs collected was successfully sequenced and confirmed as T. infestans. Most of the bugs were captured from Aspidosperma quebracho-blanco (Schlechter) hollow tree trunks harboring parrot nests. All of the T. infestans collected from the nearest house located at 10 km from the sylvatic foci displayed normal chromatic characters. The repeated finding of T. infestans in sylvatic habitats, albeit at very low density, shows that this species is capable of maintaining viable sylvatic foci in the absence of human hosts and immigration from domestic populations. These are the first confirmed findings of sylvatic T. infestans colonies in Argentina and of dark morphs in the Argentine Chaco. PMID:19769054

Glyphosate and AMPA contents in sediments produced by wind erosion of agricultural soils in Argentina

NASA Astrophysics Data System (ADS)

Aparicio, Virginia; Aimar, Silvia; De Gerónimo, Eduardo; Buschiazzo, Daniel; Mendez, Mariano; Costa, José Luis

2014-05-01

Wind erosion of soils is an important event in arid and semiarid regions of Argentina. The magnitude of wind erosion occurring under different management practices is relatively well known in this region but less information is available on the quality of the eroded material. Considering that the intensification of agriculture may increase the concentrations of substances in the eroded material, producing potential negative effects on the environment, we analyzed the amount of glyphosate and AMPA in sediments produced by wind erosion of agricultural soils of Argentina. Wind eroded materials were collected by means of BSNE samplers in two loess sites of the semiarid region of Argentina: Chaco and La Pampa. Samples were collected from 1 ha square fields at 13.5, 50 and 150 cm height. Results showed that at higher heights the concentrations of glyphosate and AMPA were mostly higher. The glyphosate concentration was more variable and higher in Chaco (0.66 to 313 µg kg-1) than in La Pampa (4.17 to 114 µg kg-1). These results may be due to the higher use of herbicides in Chaco, where the predominant crops are soybeans and corn, produced under no-tillage. Under these conditions the use of glyphosate for weeds control is a common practice. Conversely, AMPA concentrations were higher in La Pampa (13.1 to 101.3 µg kg-1) than in Chaco (1.3 to 83 µg kg-1). These preliminary results show high concentrations of glyphosate and AMPA in wind eroded materials of agricultural soils of Argentina. More research is needed to confirm these high concentrations in other conditions in order to detect the temporal and spatial distribution patterns of the herbicide.

Reduced population variance in strontium isotope values informs domesticated turkey use at Chaco Canyon, New Mexico, USA

USGS Publications Warehouse

Grimstead, Deanna N; Reynolds, Amanda C; Hudson, Adam M; Akins, Nancy J; Betancourt, Julio L.

2016-01-01

Traditionally strontium isotopes (87Sr/86Sr) have been used as a sourcing tool in numerous archaeological artifact classes. The research presented here demonstrates that 87Sr/86Srbioapatite ratios also can be used at a population level to investigate the presence of domesticated animals and methods of management. The proposed methodology combines ecology, isotope geochemistry, and behavioral ecology to assess the presence and nature of turkey (Meleagris gallopavo) domestication. This case study utilizes 87Sr/86Srbioapatite ratios from teeth and bones of archaeological turkey, deer (Odocoileus sp.), lagomorph (Lepus sp. and Sylvilagus sp.), and prairie-dog (Cynomys sp.) from Chaco Canyon, New Mexico, U.S.A. (ca. A.D. 800 – 1250). Wild deer and turkey from the southwestern U.S.A. have much larger home ranges and dispersal behaviors (measured in kilometers) when compared to lagomorphs and prairie dogs (measured in meters). Hunted deer and wild turkey from archaeological contexts at Chaco Canyon are expected to have a higher variance in their 87Sr/86Srbioapatite ratios, when compared to small range taxa (lagomorphs and prairie dogs). Contrary to this expectation, 87Sr/86Srbioapatite values of turkey bones from Chacoan assemblages have a much lower variance than deer and are similar to that of smaller mammals. The sampled turkey values show variability most similar to lagomorphs and prairie dogs, suggesting the turkeys from Chaco Canyon were consuming a uniform diet and/or were constrained within a limited home range, indicating at least proto-domestication. The population approach has wide applicability for evaluating the presence and nature of domestication when combined with paleoecology and behavioral ecology in a variety of animals and environments.

Differences in production, carbon stocks and biodiversity outcomes of land tenure regimes in the Argentine Dry Chaco

NASA Astrophysics Data System (ADS)

Marinaro, Sofía; Grau, H. Ricardo; Gasparri, Néstor Ignacio; Kuemmerle, Tobias; Baumann, Matthias

2017-04-01

Rising global demand for agricultural products results in agricultural expansion and intensification, with substantial environmental trade-offs. The South American Dry Chaco contains some of the fastest expanding agricultural frontiers worldwide, and includes diverse forms of land management, mainly associated with different land tenure regimes; which in turn are segregated along environmental gradients (mostly rainfall). Yet, how these regimes impact the environment and how trade-offs between production and environmental outcomes varies remains poorly understood. Here, we assessed how biodiversity, biomass stocks, and agricultural production, measured in meat-equivalents, differ among land tenure regimes in the Dry Chaco. We calculated a land-use outcome index (LUO) that combines indices comparing actual vs. potential values of ‘preservation of biodiversity’ (PI), ‘standing biomass’ (BI) and ‘meat production’ (MI). We found land-use outcomes to vary substantially among land-tenure regimes. Protected areas showed a biodiversity index of 0.75, similar to that of large and medium-sized farms (0.72 in both farming systems), and higher than in the other tenure regimes. Biomass index was similar among land tenure regimes, whereas we found the highest median meat production index on indigenous lands (MI = 0.35). Land-use outcomes, however, varied more across different environmental conditions than across land tenure regimes. Our results suggest that in the Argentine Dry Chaco, there is no single land tenure regime that better minimizes the trade-offs between production and environmental outcomes. A useful approach to manage these trade-offs would be to develop geographically explicit guidelines for land-use zoning, identifying the land tenure regimes more appropriate for each zone.

Genetic variability, phylogenetic relationships and gene flow in Triatoma infestans dark morphs from the Argentinean Chaco

PubMed Central

Piccinali, R. V.; Marcet, P. L.; Ceballos, L. A.; Kitron, U.; Gürtler, R. E.; Dotson, E. M.

2011-01-01

The recent discovery of sylvatic populations of Triatoma infestans outside the Andean Valleys of Bolivia prompted an evolutionary question about the putative ancestral area of origin and dispersal of the species, and an epidemiological question regarding the possible role of these sylvatic populations in the recolonization process of insecticide-treated houses. The finding of a population of sylvatic melanic T. infestans (dark morphs) in the Argentinean dry Chaco at 7 km from a peridomestic bug population of typical coloration gave us the opportunity to test both questions simultaneously by employing phylogenetic and population genetic approaches. For this purpose we analyzed sylvatic and peridomestic bugs using sequence-based mitochondrial and nuclear markers (mtCOI and ITS-1) and microsatellites. Sylvatic bugs were confirmed to be T. infestans and not hybrids, and showed high levels of genetic variability and departures from neutral expectations for mtCOI variation. New ITS-1 and mtCOI haplotypes were recorded, as well as haplotypes shared with peridomestic and/or domestic bugs from previous records. The peridomestic population was invariant for ITS-1 and mtCOI, but showed variability for microsatellites and signatures of a population bottleneck, probably due to a limited number of founders. Phylogenetic analyses were consistent with the presence of ancestral haplotypes in sylvatic bugs. According to F-statistics and assignment methods there was a significant differentiation between sylvatic and peridomestic bugs and gene flow was low and asymmetric, with more bugs moving from the peridomicile to the sylvatic environment. These results support the hypothesis of the Chaco region as the area of origin of T. infestans, and a limited role of sylvatic melanic T. infestans in peridomestic infestation in the Argentinean Chaco. PMID:21352954

The sylvatic transmission cycle of Trypanosoma cruzi in a rural area in the humid Chaco of Argentina.

PubMed

Alvarado-Otegui, J A; Ceballos, L A; Orozco, M M; Enriquez, G F; Cardinal, M V; Cura, C; Schijman, A G; Kitron, U; Gürtler, R E

2012-10-01

Little is known about the sylvatic transmission cycle of Trypanosoma cruzi in the Gran Chaco ecoregion. We conducted surveys to identify the main sylvatic hosts of T. cruzi, parasite discrete typing units and vector species involved in Pampa del Indio, a rural area in the humid Argentinean Chaco. A total of 44 mammals from 14 species were captured and examined for infection by xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). Ten (22.7%) mammals were positive by xenodiagnosis or kDNA-PCR. Four of 11 (36%) Didelphis albiventris (white-eared opossums) and six of nine (67%) Dasypus novemcinctus (nine-banded armadillos) were positive by xenodiagnosis and or kDNA-PCR. Rodents, other armadillo species, felids, crab-eating raccoons, hares and rabbits were not infected. Positive animals were highly infectious to the bugs that fed upon them as determined by xenodiagnosis. All positive opossums were infected with T. cruzi I and all positive nine-banded armadillos with T. cruzi III. Extensive searches in sylvatic habitats using 718 Noireau trap-nights only yielded Triatoma sordida whereas no bug was collected in 26 light-trap nights. Four armadillos or opossums fitted with a spool-and-line device were successfully tracked to their refuges; only one Panstrongylus geniculatus was found in an armadillo burrow. No sylvatic triatomine was infected with T. cruzi by microscopical examination or kDNA-PCR. Our results indicate that two independent sylvatic transmission cycles of T. cruzi occur in the humid Chaco. The putative vectors of both cycles need to be identified conclusively. Copyright © 2012 Elsevier B.V. All rights reserved.

The sylvatic transmission cycle of Trypanosoma cruzi in a rural area in the humid Chaco of Argentina

PubMed Central

Alvarado-Otegui, J.A.; Ceballos, L.A.; Orozco, M.M.; Enriquez, G.F.; Cardinal, M.V.; Cura, C.; Schijman, A.G.; Kitron, U.; Gürtler, R.E.

2012-01-01

Little is known about the sylvatic transmission cycle of Trypanosoma cruzi in the Gran Chaco ecoregion. We conducted surveys to identify the main sylvatic hosts of T. cruzi, parasite discrete typing units and vector species involved in Pampa del Indio, a rural area in the humid Argentinean Chaco. A total of 44 mammals from 14 species was captured and examined for infection by xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). Ten (22.7%) mammals were positive by xenodiagnosis or kDNA-PCR. Four of 11 (36%) Didelphis albiventris (white-eared opossums) and six of nine (67%) Dasypus novemcinctus (nine-banded armadillos) were positive by xenodiagnosis and or kDNA-PCR. Rodents, other armadillo species, felids, crab-eating raccoons, hares and rabbits were not infected. Positive animals were highly infectious to the bugs that fed upon them as determined by xenodiagnosis. All positive opossums were infected with T. cruzi I and all positive nine-banded armadillos with T. cruzi III. Extensive searches in sylvatic habitats using 718 Noireau trap-nights only yielded Triatoma sordida whereas no bug was collected in 26 light-trap nights. Four armadillos or opossums fitted with a spool-and-line device were successfully tracked to their refuges; only one Panstrongylus geniculatus was found in an armadillo burrow. No sylvatic triatomine was infected with T. cruzi by microscopical examination or kDNA-PCR. Our results indicate that two independent sylvatic transmission cycles of T. cruzi occur in the humid Chaco. The putative vectors of both cycles need to be identified conclusively. PMID:22771688

Myth and catastrophic reality: using cosmogonic mythology to identify cosmic impacts and massive plinian eruptions in holocene South America.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masse, W. B.

Major natural catastrophes (e.g., 'universal' floods, fire, darkness, and sky falling down) are prominently reflected in traditional South American creation myths, cosmology, religion, and worldview. We are now beginning to recognize that cosmogonic myths represent a rich and largely untapped data set concerning the most dramatic natural events and processes experienced by each cultural group during the past several thousand years. Observational details regarding specific catastrophes are encoded in myth storylines, typically cast in terms of supernatural characters and actions. Not only are the myths amenable to scientific analysis, but also some sets of myths encode multiple catastrophes in meaningfulmore » relative chronological order. The present study considers more than 4200 myths, including more than 260 'universal' catastrophe myths from cultural groups throughout South America. These myths are examined in light of available geological, paleoenvironmental, archeological, and documentary evidence. Our analysis reveals three possible ultra-plinian volcanic eruptions, two in Columbia and the other in the Gran Chaco, the latter likely associated with a poorly dated late Holocene eruption of Nuevo Mundo in central Bolivia. Our analysis also identifies a set of traditions likely linked with the well-known Campo del Cielo iron meteorite impact in northern Argentina originally hypothesized to have occurred around 4000 years ago. Intriguingly, these traditions strongly suggest that the Campo del Cielo impact triggered widespread mass fires in the Gran Chaco region and possibly in the Brazilian Highlands. Several other potential cosmic impacts, distinct from Campo del Cielo, are hinted at in the mythology of other locations in South America. The numerous catastrophe myths in the Gran Chaco region exhibit the most coherent chronological sequence of any South American region. The sequence begins with a 'Great Flood,' by far the most widespread catastrophe myth in South America, typically represented as the beginning of our modern world. The great flood is followed 'many generations' later by the 'Great Fire' (hypothesized as the Campo del Cielo impact) with the 'Great Darkness' and 'sky falling down' (hypothesized as the Nuevo Mundo eruption) being the most recent catastrophe, occurring 'many generations' after the great fire. We draw upon the physical record to suggest rough calendrical dates for these witnessed catastrophic events.« less

New discoveries of sylvatic Triatoma infestans (Hemiptera: Reduviidae) throughout the Bolivian Chaco.

PubMed

Waleckx, Etienne; Depickère, Stéphanie; Salas, Renata; Aliaga, Claudia; Monje, Marcelo; Calle, Hiber; Buitrago, Rosio; Noireau, François; Brenière, Simone Frédérique

2012-03-01

Sylvatic populations of Triatoma infestans might be involved in the recolonization of human dwellings. We report here the discoveries of new T. infestans sylvatic foci in the Bolivian Chaco. Eighty-one triatomines were caught, 38 of which were identified as T. infestans. Triatoma sordida and Panstrongylus geniculatus were the other species collected. One T. infestans and one T. sordida were infected with Trypanosoma cruzi TcI; one T. infestans was infected with TcII. These discoveries add to the debate on the geographic distribution of sylvatic T. infestans populations, the geographic origin of the species, and the epidemiological role of these populations.

New Discoveries of Sylvatic Triatoma infestans (Hemiptera: Reduviidae) Throughout the Bolivian Chaco

PubMed Central

Waleckx, Etienne; Depickère, Stéphanie; Salas, Renata; Aliaga, Claudia; Monje, Marcelo; Calle, Hiber; Buitrago, Rosio; Noireau, François; Brenière, Simone Frédérique

2012-01-01

Sylvatic populations of Triatoma infestans might be involved in the recolonization of human dwellings. We report here the discoveries of new T. infestans sylvatic foci in the Bolivian Chaco. Eighty-one triatomines were caught, 38 of which were identified as T. infestans. Triatoma sordida and Panstrongylus geniculatus were the other species collected. One T. infestans and one T. sordida were infected with Trypanosoma cruzi TcI; one T. infestans was infected with TcII. These discoveries add to the debate on the geographic distribution of sylvatic T. infestans populations, the geographic origin of the species, and the epidemiological role of these populations. PMID:22403316

Considerations on the Species Complex of the Cortelezzii series (Diptera: Psychodidae) and Description of Evandromyia chacuensis sp. nov., a New Phlebotomine Species of the Chaco Region, Argentina.

PubMed

Szelag, Enrique A; Rosa, Juan R; Galati, Eunice A B; Andrade Filho, José D; Salomón, Oscar D

2018-04-06

A new species of phlebotomine sand fly is described and illustrated based on male and female specimens collected in rural and semi-urban areas of the Chaco Province, Argentina. A separation of the Cortelezzii series in two species complexes is proposed, as is a species key for its identification. The morphological characters of the new species permit its inclusion in the Cortelezzii series of genus Evandromyia, subgenus Barrettomyia (Diptera: Psychodidae). The species is named Evandromyia chacuensis sp. nov. Szelag, Rosa, Galati, Andrade Fhilo & Salomón (Diptera: Psychodidae).

Archeological Surveys

NASA Technical Reports Server (NTRS)

1978-01-01

NASA remote sensing technology is being employed in archeological studies of the Anasazi Indians, who lived in New Mexico one thousand years ago. Under contract with the National Park Service, NASA's Technology Applications Center at the University of New Mexico is interpreting multispectral scanner data and demonstrating how aerospace scanning techniques can uncover features of prehistoric ruins not visible in conventional aerial photographs. The Center's initial study focused on Chaco Canyon, a pre-Columbia Anasazi site in northeastern New Mexico. Chaco Canyon is a national monument and it has been well explored on the ground and by aerial photography. But the National Park Service was interested in the potential of multispectral scanning for producing evidence of prehistoric roads, field patterns and dwelling areas not discernible in aerial photographs. The multispectral scanner produces imaging data in the invisible as well as the visible portions of the spectrum. This data is converted to pictures which bring out features not visible to the naked eye or to cameras. The Technology Applications Center joined forces with Bendix Aerospace Systems Division, Ann Arbor, Michigan, which provided a scanner-equipped airplane for mapping the Chaco Canyon area. The NASA group processed the scanner images and employed computerized image enhancement techniques to bring out additional detail.

Toward linking maize chemistry to archaeological agricultural sites in the North American Southwest

USGS Publications Warehouse

Cordell, L.S.; Durand, S.R.; Antweiler, Ronald C.; Taylor, Howard E.

2001-01-01

Maize (Zea mays L.) was the staple domestic food crop for Ancestral Pueblo people throughout the northern American Southwest. It is thought to have been the basic food of the inhabitants of Chaco Canyon. New Mexico, a location that was a major centre of Ancestral Pueblo building and population during the 11th and early 12th centuries AD. Modern heirloom varieties of Native American corn have been difficult to grow in experimental fields in Chaco Canyon. Given an abundance of apparent storage structures in Chacoan buildings, it is possible that some corn recovered from archaeological contexts, was imported from surrounding areas. The ultimate goal of this research is to determine whether the corn in Chaco Canyon was grown locally or imported. This paper establishes the feasibility of a method to accomplish this goal. This study reports the results of using inductively coupled plasma-mass spectrometric (ICP-MS) instrumentation to determine chemical constituents of experimental fields and modern heirloom varieties of Native American corn. Analysis of 19 elements is adequate to differentiate soil and corn from three field areas. These results are promising: however, a number of problems, including post-depositional alterations in maize, remain to be solved. ?? 2001 Academic Press.

Development and application of methods used to source prehistoric Southwestern maize: a review

USGS Publications Warehouse

Benson, Larry V.

2012-01-01

Archaeological cobs free of mineral contaminants should be used to source the soils in which they were grown. Mineral contaminants often contain much higher concentrations of metals than vegetal materials and can alter a cob’s apparent metal and heavy-isotope content. Cleaning a cob via immersion in an acid solution for more than a few minutes will result in the incongruent and sometimes complete leaching of metals, including strontium (Sr), from the cob. When using 87Sr/Sr to determine the location of potential agriculture fields, it is best to either integrate several depth-integrated soil samples or to integrate several vegetation samples from individual fields. Biologically labile Sr in semi-arid Southwestern soils largely originates from eolian source or sources and usually is not derived from underlying bedrock. Existing Sr-isotope data indicate that archaeological cobs from Aztec Ruins came from either the Mesa Verde-McElmo Dome or Totah areas, that Pueblo Bonito and Chetro Ketl cobs, from Chaco Canyon that predate A.D. 1130, probably came from the Rio Chaco corridor, and that cobs from Chaco Canyon, that postdate A.D. 1130, probably came from either the Totah or Zuni areas.

Sustainable management of the Gran Chaco of South America: Ecological promise and economic constraints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bucher, E.H.; Huszar, P.C.

1999-10-01

The vast plain known as the Gran Chaco is a natural region of more than 1--3 million square kilometers, the second largest natural biome in south America, with only the Amazon region being larger. It extends over parts of Argentina, Bolivia, Paraguay and, marginally, Brazil. The original landscape of the region was mostly a park land with patches of hardwoods intermingled with grasslands. Increasing human encroachment, largely by poor campesinos, with associated overgrazing, excessive timber harvesting, charcoal production and over-exploitation of wildlife, is transforming the region into a dense and unproductive shrub land and is contributing to increasing rural poverty.more » A management system for the sustainable use of the Chaco has been developed based on a multiple-species ranching system that includes beef, timber, charcoal and wildlife production. An evaluation of the management system finds that it is capable of protecting and enhancing the resource base, while providing higher economic returns in a sustainable manner. However, high initial costs, as well as a divergence between the best interests of campersinos and society, jeopardize the feasibility of the managed system.« less

Susceptibility to deltamethrin of wild and domestic populations of Triatoma infestans of the Gran Chaco and the Inter-Andean Valleys of Bolivia.

PubMed

Gomez, Marinely Bustamante; D'Avila, Grasielle Caldas Pessoa; Orellana, Ana Lineth Garcia; Cortez, Mirko Rojas; Rosa, Aline Cristine Luiz; Noireau, François; Diotaiuti, Liléia Gonçalves

2014-11-14

The persistence of Triatoma infestans and the continuous transmission of Trypanosoma cruzi in the Inter-Andean Valleys and in the Gran Chaco of Bolivia are of great significance. Coincidentally, it is in these regions the reach of the vector control strategies is limited, and reports of T. infestans resistance to insecticides, including in wild populations, have been issued. This study aims to characterize the susceptibility to deltamethrin of wild and domestic populations of T. infestans from Bolivia, in order to better understand the extent of this relevant problem. Susceptibility to deltamethrin was assessed in nine, wild and domestic, populations of T. infestans from the Gran Chaco and the Inter-Andean Valleys of Bolivia. Serial dilutions of deltamethrin in acetone (0.2 μL) were topically applied in first instar nymphs (F1, five days old, fasting, weight 1.2 ± 0.2 mg). Dose response results were analyzed with PROBIT version 2, determining the lethal doses, slope and resistance ratios (RR). Qualitative tests were also performed. Three wild T. infestans dark morph samples of Chaco from the Santa Cruz Department were susceptible to deltamethrin with RR50 of <2, and 100% mortality to the diagnostic dose (DD); however, two domestic populations from the same region were less susceptible than the susceptibility reference lineage (RR50 of 4.21 and 5.04 respectively and 93% DD). The domestic population of Villa Montes from the Chaco of the Tarija Department presented high levels of resistance (RR50 of 129.12 and 0% DD). Moreover, the domestic populations from the Valleys of the Cochabamba Department presented resistance (RR50 of 8.49 and 62% DD), the wild populations were less susceptible than SRL and T. infestans dark morph populations (RR50 < 5). The elimination of T. infestans with pyrethroid insecticides in Brazil, Uruguay, Chile, and its drastic reduction in large parts of Paraguay and Argentina, clearly indicates that pyrethroid resistance was very uncommon in non-Andean regions. The pyrethroid susceptibility of non-Andean T. infestans dark morph population, and the resistance towards it, of Andean T. infestans wild and domestic populations, indicates that the Andean populations from Bolivia are less susceptible.

Environmental risk assessment of arsenic and fluoride in the Chaco Province, Argentina: research advances.

PubMed

Buchhamer, Edgar E; Blanes, Patricia S; Osicka, Rosa M; Giménez, M Cecilia

2012-01-01

The arsenic (As) and fluoride (F⁻) concentration in groundwater and potential adverse human health risk was investigated in the Central-West Region of the Chaco Province, northern Argentina. The mean concentration of As in shallow groundwater was 95 μg/L, where 76% of samples exceeded the World Health Organization (WHO) guideline value of 10 μg/L, while in deep groundwater it was 90 μg/L, where 63% samples exceeded 10 μg/L. For As health risk assessment, the average daily dose, hazard quotient (HQ), and cancer risk were calculated. The values of HQ were found to be >1 in 77% of samples. This level of contamination is considered to constitute a high chronic risk compared with U.S. Environmental Protection Agency (EPA) guidelines. Further, a significant portion of the population has lifetime carcinogenic risk >10⁻⁴ and may suffer from cancer. A positive correlation was observed between As and F⁻ in groundwater. The Código Alimentario Argentino (CAA) suggested a limit of F⁻ in drinking water as low as 0.8 mg/L under tropical environmental conditions; however, in shallow (39%) and deep groundwater (32%), samples exceeded these values. Exposure to F⁻ was calculated and compared with the adequate intake of minimal safe level exposure dose of 0.05 mg/kg/d and it was noted that 42% of population may be at high risk of fluorosis. Chronic exposure to high As and F⁻ levels in this population represents a concern due to possible adverse health effects attributed to these elements.

Degradación de Marismas Costera: el Impacto de la Eutrofización en la Supervivencia del las Marismas Costeras en New England y Central California, USA. (Salt Marsh Deterioration in New England and Central California: Impacts of Eutrophication on Salt Marsh Survival.)

EPA Science Inventory

Las marismas costeras proporcionan numerosos beneficios a los ecosistemas, incluyendo la proporción del hábitat de la flora y fauna, la protección de las zonas costeras contra inundaciones durante eventos extremos, mejoran la calidad del agua para las almejas y ostras a través de...

On the relationships of 'Marmosa' formosa Shamel, 1930 (Marsupialia: Didelphidae), a phylogenetic puzzle from the Chaco of northern Argentina

USGS Publications Warehouse

Voss, Robert S.; Gardner, Afred L.; Jansa, Sharon A.

2004-01-01

The holotype and only known specimen of Marmosa formosa Shamel, a nominal species currently synonymized with Gracilinanus agilis Burmeister, is strikingly unlike any other known didelphid marsupial. Phylogenetic analyses based on nonmolecular characters and IRBP sequences suggest that formosa is either the sister-taxon of Thylamys (including Lestodelphys) or Monodelphis. Because neither alternative is strongly supported by the data at hand, and because including formosa in Thylamys or in Monodelphis would compromise the diagnosability of those taxa, a new genus?Chacodelphys?is proposed to contain it. Currently known only from northern Argentina, Chacodelphys formosa may be widely distributed in the Chaco and other adjacent Neotropical biomes.

"Chiriguano" Astronomy - Venus and a Guarani New Year

NASA Astrophysics Data System (ADS)

Pereira, Gonzalo

A Supreme Decree emitted by the government of Bolivia instituted the celebration of the June solstices in view of the fact that the indigenous people, both the Andean highlands and the Amazon and Chaco, "have commemorated this event for thousands of years" (Gobierno del Estado Plurinacional de Bolivia, Decreto Supremo N° 0173, June16, 2009, La Paz). In the case of the lowlands' indigenous, particularly the Guarani people, the decree mentions the planet Venus as the argument for this celebration. In this case of study and in light of astronomical and ethnographic evidence, we analyze the relevance of this decree in the case of the Guarani people of the Bolivian Chaco region, known as "Chiriguanos".

Strontium isotopes reveal distant sources of architectural timber in Chaco Canyon, New Mexico

USGS Publications Warehouse

English, N.B.; Betancourt, J.L.; Dean, J.S.; Quade, Jay

2001-01-01

Between A.D. 900 and 1150, more than 200,000 conifer trees were used to build the prehistoric great houses of Chaco Canyon, New Mexico, in what is now a treeless landscape. More than one-fifth of these timbers were spruce (Picea) or fir (Abies) that were hand-carried from isolated mountaintops 75-100 km away. Because strontium from local dust, water, and underlying bedrock is incorporated by trees, specific logging sites can be identified by comparing 87Sr/86Sr ratios in construction beams from different ruins and building periods to ratios in living trees from the surrounding mountains. 87Sr/86Sr ratios show that the beams came from both the Chuska and San Mateo (Mount Taylor) mountains, but not from the San Pedro Mountains, which are equally close. Incorporation of logs from two sources in the same room, great house, and year suggest stockpiling and intercommunity collaboration at Chaco Canyon. The use of trees from both the Chuska and San Mateo mountains, but not from the San Pedro Mountains, as early as A.D. 974 suggests that selection of timber sources was driven more by regional socioeconomic ties than by a simple model of resource depletion with distance and time.

Strontium isotopes reveal distant sources of architectural timber in Chaco Canyon, New Mexico.

PubMed

English, N B; Betancourt, J L; Dean, J S; Quade, J

2001-10-09

Between A.D. 900 and 1150, more than 200,000 conifer trees were used to build the prehistoric great houses of Chaco Canyon, New Mexico, in what is now a treeless landscape. More than one-fifth of these timbers were spruce (Picea) or fir (Abies) that were hand-carried from isolated mountaintops 75-100 km away. Because strontium from local dust, water, and underlying bedrock is incorporated by trees, specific logging sites can be identified by comparing (87)Sr/(86)Sr ratios in construction beams from different ruins and building periods to ratios in living trees from the surrounding mountains. (87)Sr/(86)Sr ratios show that the beams came from both the Chuska and San Mateo (Mount Taylor) mountains, but not from the San Pedro Mountains, which are equally close. Incorporation of logs from two sources in the same room, great house, and year suggest stockpiling and intercommunity collaboration at Chaco Canyon. The use of trees from both the Chuska and San Mateo mountains, but not from the San Pedro Mountains, as early as A.D. 974 suggests that selection of timber sources was driven more by regional socioeconomic ties than by a simple model of resource depletion with distance and time.

Taxonomic status of Paraguay's only endemic bird, the Chaco Nothura Nothura chacoensis (Aves: Tinamidae).

PubMed

Hayes, Floyd E; RodrÍguez, Oscar; Thalman, Erika R; Castellanos, Emily A; Sterling, John

2018-03-08

The Chaco Nothura Nothura chacoensis Conover is endemic to the Chaco of western Paraguay. Originally described as a subspecies of the Spotted Nothura N. maculosa (Temminck), it has been regarded by many authorities as a distinct species based on alleged sympatry with N. maculosa. However, an earlier study revealed no differences in cytochrome b sequences between the two taxa. We reanalyzed the geographic distribution and morphological variation of N. chacoensis and N. maculosa in western Paraguay based on museum specimens. There is no locality where specimens of both taxa were collected, thus there is no evidence for sympatry. Morphologically the two taxa did not differ in any size or shape variable. Plumage characters overlapped in a few specimens. We recorded vocalizations from at least four individuals of N. chacoensis within its known range. Its typical territorial song was a very rapid, relatively monotone trill that was virtually identical with the most frequent territorial song of N. maculosa in length, number of notes, rate of notes, and emphasized frequency, and differed substantially from the songs of other species of Nothura. Based on distributional, morphological, biochemical, and especially vocalization data, we conclude that N. chacoensis should be regarded as a subspecies of N. maculosa.

First Report of Colonies of Sylvatic Triatoma infestans (Hemiptera: Reduviidae) in the Paraguayan Chaco, Using a Trained Dog

PubMed Central

Rolón, Miriam; Vega, María Celeste; Román, Fabiola; Gómez, Ana; Rojas de Arias, Antonieta

2011-01-01

In the Gran Chaco region, control of Triatoma infestans has been limited by persistent domestic infestations despite the efforts of the Vector Control Services. In Paraguay, this region is the highest endemic area in the country, showing high levels of indoor and outdoor infestation. Although sylvatic T. infestans have been found in the Bolivian and Argentine Chaco, similar searches for sylvatic populations of this species in Paraguay had been unsuccessful over the last 20 years. Here we present a new approach to detecting sylvatic Triatominae, using a trained dog, which has successfully confirmed sylvatic populations of T. infestans and other triatomine species in Paraguay. A total of 22 specimens corresponding to dark morph forms of T. infestans were collected, and 14 were confirmed as T. infestans by the mitochondrial cytochrome B gene analysis. Through this analysis, one of which were previously reported and a second that was a new haplotype. Triatomines were captured from amongst vegetation such as dry branches and hollows trees of different species such Aspidosperma quebracho-blanco, Bulnesia sarmientoi and Stetsonia coryne. The colonies found have been small and without apparent infection with Trypanosoma cruzi. During the study, Triatoma sordida and Triatoma guasayana have also been found in ecotopes close to those of T. infestans. PMID:21572522

HLA-DRB1 alleles in four Amerindian populations from Argentina and Paraguay

PubMed Central

2009-01-01

The major histocompatibility complex (MHC) is one of the biological systems of major polymorphisms. The study of HLA class II variability has allowed the identification of several alleles that are characteristic to Amerindian populations, and it is an excellent tool to define the relations and biological affinities among them. In this work, we analyzed the allelic distribution of the HLA-DRB1 class II locus in four Amerindian populations: Mapuche (n = 34) and Tehuelche (n = 23) from the Patagonian region of Argentina, and Wichi SV (n = 24) and Lengua (n = 17) from the Argentinean and Paraguayan Chaco regions, respectively. In all of these groups, relatively high frequencies of Amerindian HLA-DRB1 alleles were observed (DRB1*0403, DRB1*0407, DRB1*0411, DRB1*0417, DRB1*0802, DRB1*0901, DRB1*1402, DRB1*1406 and DRB1*1602). However, we also detected the presence of non-Amerindian variants in Mapuche (35%) and Tehuelche (22%). We compared our data with those obtained in six indigenous groups of the Argentinean Chaco region and in a sample from Buenos Aires City. The genetic distance dendrogram showed a clear-cut division between the Patagonian and Chaco populations, which formed two different clusters. In spite of their linguistic differences, it can be inferred that the biological affinities observed are in concordance with the geographic distributions and interethnic relations established among the groups studied. PMID:21637670

Pueblo Folklore, Landscape Phenomenology and the Visual Poetics of Fajada Butte

NASA Astrophysics Data System (ADS)

Carey, C.

2009-08-01

In the interest of reexamining the site of Fajada Butte in Chaco Canyon, this paper seeks to recontextualize discussions of its controversial spiral petroglyphs and astronomical phenomena (Sun Daggers) with reference to landscape phenomenology, visual and literary poetics, and the astronomical orientation of contemporary Pueblo ceremonial practices. The dearth of recent scholarship on Fajada Butte may have arisen from the many controversial arguments about its function from a variety of disciplinary locations including archaeology, anthropology, geology, and archeoastronomy. Via an emphasis on the physical landscape, storytelling, contemporary ceremonial practices and ancestral ties to Chaco Canyon, the Zuni and Hopi pueblos provide a context for re-examining the astronomical phenomena of Fajada Butte as a natural shrine of the of Chacoan culture and repository of an array of symbolic content.

Navajo minettes in the Cerros de las Mujeres, New Mexico

NASA Astrophysics Data System (ADS)

Vaniman, D.; Laughlin, A. W.; Gladney, E. S.

1985-06-01

The Cerros de las Mujeres in west-central New Mexico are three mafic minette plugs that should be considered part of the Navajo volcanic fields on the central Colorado Plateau. This newly recognized occurrence extends the Navajo volcanic fields to the southeastern margin of the Colorado Plateau, within 45 km of the extensional tectonic setting in which the Mogollon ash-flow tuff cauldrons occur. The Cerros de las Mujeres provide additional evidence for contemporaneous sodic and potassic volcanism within the Navajo volcanic fields.

The Strontium Fingerprint and Footprint: Using 87Sr/86Sr to Find the Sources and Range of Architectural Timber Acquisition of Great House Construction at Chaco Canyon, New Mexico

NASA Astrophysics Data System (ADS)

English, N. B.; Reynolds, A. C.; Quade, J.; Betancourt, J. L.

2006-12-01

We describe the spatial and temporal patterns of timber acquisition by great house builders in Chaco Canyon, New Mexico. The 87Sr/86Sr ratios from annually-dated, architectural logs in 10^{th} to 12^{th} century structures are compared to the 87Sr/86Sr of modern tree stands from the surrounding mountains. Although not a stable isotope system, the long half-life of the 87Sr parent (87Rb, t1/2 = 48.8 Ga) yields a stable isotope system on the timescales used to determine the geographic origin of ecosystem resources. The small mass difference among strontium's isotopes eliminates measurable biologic or kinetic fractionation at earth surface conditions. Strontium tracer studies, however, do require distinct end-member ratios to be feasible. Strontium isotopes, alone or in combination with other isotopes, provide a simple way to study and trace the geographic origin of ecosystem resources. Over the 150 km-wide Chaco Basin, 87Sr/86Sr ratios of modern trees range from 0.7055 to 0.7192. 87Sr/86Sr ratios from this and other studies show that during great house construction Chaco Canyon was provisioned with plant materials that came from more than 75 km away in all directions. This includes (1) corn (Zea mays) grown on the eastern flanks of the Chuska Mountains and floodplain of the San Juan River to the west and north, (2) spruce (Picea sp.) and fir (Abies sp.) architectural beams from the high crests of the Chuska and San Mateo Mountains to the west and south, and (3) ponderosa pine (Pinus ponderosa) from the low slopes of the La Platas and San Juan Mountains to the north, the San Pedro Mountains to the east, the Chuska and San Mateo Mountains and nearby mesas. There are no systematic patterns in spruce/fir or ponderosa provenance by great house (Pueblo Bonito, Chetro Ketl, Pueblo del Arroyo) or by time, suggesting the use of stockpiles from a few preferred sources from the beginning of large scale construction in or around Chaco Canyon. This is contrary to the view that Chacoan's travelled further for timber as nearby stands of timber were depleted. The multiple and distant sources for food and timber, now based on hundreds of isotopic values from modern and archeological samples, confirm conventional wisdom about the geographic footprint of the larger Chacoan system. While our study addresses ancient resource procurement patterns, the strontium method is suitable for many modern studies including ecological and forensic applications.

Archaeogenomic evidence reveals prehistoric matrilineal dynasty.

PubMed

Kennett, Douglas J; Plog, Stephen; George, Richard J; Culleton, Brendan J; Watson, Adam S; Skoglund, Pontus; Rohland, Nadin; Mallick, Swapan; Stewardson, Kristin; Kistler, Logan; LeBlanc, Steven A; Whiteley, Peter M; Reich, David; Perry, George H

2017-02-21

For societies with writing systems, hereditary leadership is documented as one of the hallmarks of early political complexity and governance. In contrast, it is unknown whether hereditary succession played a role in the early formation of prehistoric complex societies that lacked writing. Here we use an archaeogenomic approach to identify an elite matriline that persisted between 800 and 1130 CE in Chaco Canyon, the centre of an expansive prehistoric complex society in the Southwestern United States. We show that nine individuals buried in an elite crypt at Pueblo Bonito, the largest structure in the canyon, have identical mitochondrial genomes. Analyses of nuclear genome data from six samples with the highest DNA preservation demonstrate mother-daughter and grandmother-grandson relationships, evidence for a multigenerational matrilineal descent group. Together, these results demonstrate the persistence of an elite matriline in Chaco for ∼330 years.

Archaeogenomic evidence reveals prehistoric matrilineal dynasty

PubMed Central

Kennett, Douglas J.; Plog, Stephen; George, Richard J.; Culleton, Brendan J.; Watson, Adam S.; Skoglund, Pontus; Rohland, Nadin; Mallick, Swapan; Stewardson, Kristin; Kistler, Logan; LeBlanc, Steven A.; Whiteley, Peter M.; Reich, David; Perry, George H.

2017-01-01

For societies with writing systems, hereditary leadership is documented as one of the hallmarks of early political complexity and governance. In contrast, it is unknown whether hereditary succession played a role in the early formation of prehistoric complex societies that lacked writing. Here we use an archaeogenomic approach to identify an elite matriline that persisted between 800 and 1130 CE in Chaco Canyon, the centre of an expansive prehistoric complex society in the Southwestern United States. We show that nine individuals buried in an elite crypt at Pueblo Bonito, the largest structure in the canyon, have identical mitochondrial genomes. Analyses of nuclear genome data from six samples with the highest DNA preservation demonstrate mother–daughter and grandmother–grandson relationships, evidence for a multigenerational matrilineal descent group. Together, these results demonstrate the persistence of an elite matriline in Chaco for ∼330 years. PMID:28221340

Anatomy of the Chaco cryogenic project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milios, P.B.; Harris, R.A.

1997-12-31

In the first quarter of 1996 El Paso Field Services (EPFS) began operation of a new Chaco liquids extraction plant. The plant, located in northwest New Mexico, has the capacity to extract more natural gas liquids (NGL) than any other turboexpander plant in the lower 48 states; 50,000 b/d of NGL from 600 MMscfd of gas. Its existence is the result of El Paso`s desire to combine state-of-the-art processing with processing rates that align EPFS`s interests with the interests of the producers, in order to secure a long term competitive position in the San Juan Basin. All the project stakeholders,more » the producers, the liquids transporter, the construction contractor, and the processor have benefited from the project. Without regulatory reform the project would not have happened.« less

Trypanosoma cruzi infection in Triatoma sordida before and after community-wide residual insecticide spraying in the Argentinean Chaco.

PubMed

Macchiaverna, Natalia P; Gaspe, María S; Enriquez, Gustavo F; Tomassone, Laura; Gürtler, Ricardo E; Cardinal, Marta V

2015-03-01

Triatoma sordida is a secondary vector of Trypanosoma cruzi in the Gran Chaco and Cerrado eco-regions where it frequently infests peridomestic and domestic habitats. In a well-defined area of the humid Argentine Chaco, very few T. sordida were found infected when examined by optical microscopic examination (OM). In order to further assess the role of T. sordida and the relative magnitude of subpatent bug infections, we examined the insects for T. cruzi infection, parasite Discrete Typing Units (DTUs) and bloodmeal sources using various molecular techniques. Among 205 bugs with a negative or no OM-based diagnosis, the prevalence of infection determined by kDNA-PCR was nearly the same in bugs captured before (6.3%) and 4 months after insecticide spraying (6.4%). On average, these estimates were sixfold higher than the prevalence of infection based on OM (1.1%). Only TcI was identified, a DTU typically associated with opossums and rodents. Chickens and turkeys were the only bloodmeal sources identified in the infected specimens and the main local hosts at the bugs' capture sites. As birds are refractory to T. cruzi infection, further studies are needed to identify the infectious bloodmeal hosts. The persistent finding of infected T. sordida after community-wide insecticide spraying highlights the need of sustained vector surveillance to effectively prevent T. cruzi transmission in the domestic and peridomestic habitats. Copyright © 2014 Elsevier B.V. All rights reserved.

Methicillin-resistant Staphylococcus aureus in hospitalized patients from the Bolivian Chaco.

PubMed

Bartoloni, Alessandro; Riccobono, Eleonora; Magnelli, Donata; Villagran, Ana Liz; Di Maggio, Tiziana; Mantella, Antonia; Sennati, Samanta; Revollo, Carmen; Strohmeyer, Marianne; Giani, Tommaso; Pallecchi, Lucia; Rossolini, Gian Maria

2015-01-01

Information is lacking on the methicillin-resistant Staphylococcus aureus (MRSA) clonal lineages circulating in Bolivia. We investigated the prevalence and molecular epidemiology of S. aureus colonization in hospitalized patients from the Bolivian Chaco, and compared their features with those of the few clinical isolates available from that setting. S. aureus nasal/inguinal colonization was investigated in 280 inpatients from eight hospitals in two point prevalence surveys (2012, n=90; 2013, n=190). Molecular characterization included genotyping (spa typing, multilocus sequence typing, and pulsed-field gel electrophoresis), detection of virulence genes, and SCCmec typing. Forty-one inpatients (14.6%) were S. aureus nasal/inguinal carriers, of whom five were colonized by MRSA (1.8%). MRSA isolates mostly belonged to spa-type t701, harboured SCCmec IVc, and were negative for Panton-Valentine leukocidin (PVL) genes. However, a USA300-related isolate was also detected, which showed the characteristics of the USA300 Latin American variant (USA300-LV; i.e., ST8, spa-type t008, SCCmec IVc, presence of PVL genes, absence of arcA). Notably, all the available MRSA clinical isolates (n=5, collected during 2011-2013) were also identified as USA300-LV. Overall, MRSA colonization in inpatients from the Bolivian Chaco was low. However, USA300-LV-related isolates were detected in colonization and infections, emphasizing the importance of implementing control measures to limit their further dissemination in this resource-limited area. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

The peri-urban interface and house infestation with Triatoma infestans in the Argentine Chaco: an underreported process?

PubMed Central

Provecho, Yael M; Gaspe, M Sol; del Pilar Fernández, M; Enriquez, Gustavo F; Weinberg, Diego; Gürtler, Ricardo E

2014-01-01

Peri-urban infestations with triatomine bugs, their sources and their dynamics have rarely been investigated. Here, we corroborated the reported occurrence of Triatoma infestans in a peri-urban area and in neighbouring rural houses in Pampa del Indio, in the Argentine Chaco, and identified its putative sources using spatial analysis and demographic questionnaires. Peri-urban householders reported that 10% of their premises had triatomines, whereas T. infestans was collected by timed manual searches or community-based surveillance in only nine (3%) houses. Trypanosoma cruzi-infected T. infestans and Triatoma sordida were collected indoors only in peri-urban houses and were infected with TcV and TcI, respectively. The triatomines fed on chickens, cats and humans. Peri-urban infestations were most frequent in a squatter settlement and particularly within the recently built mud houses of rural immigrants, with large-sized households, more dogs and cats and more crowding. Several of the observed infestations were most likely associated with passive bug transport from other sources and with active bug dispersal from neighbouring foci. Thus, the households in the squatter settlement were at a greater risk of bug invasion and colonisation. In sum, the incipient process of domestic colonisation and transmission, along with persistent rural-to-urban migratory flows and unplanned urbanisation, indicate the need for active vector surveillance and control actions at the peri-urban interface of the Gran Chaco. PMID:25410997

[Detection of virulence genes of the enteroaggregative pathotype in Escherichia coli strains isolated from groundwater sources in the province of Chaco, Argentina].

PubMed

Lösch, Liliana S; Gariboglio Vázquez, María L; Rivas, Marta; Merino, Luis A

2015-01-01

Groundwater is an important source of drinking water for many communities in Northern Argentina; particularly, in the province of Chaco, where about 14% of households use this natural resource. Enteroaggregative Escherichia coli is an emerging pathogen whose global importance in public health has increased in recent years. Despite the significant risk of disease linked to contaminated water exposure, the prevalence of E. coli pathotypes in aquatic environments is still not so well defined. The aim of the present study was to detect the presence of typical enteroaggregative E. coli through the recognition of its virulence factors aap, AA probe and aggR by molecular techniques. A total of 93 water samples from different small communities of Chaco were analyzed. E. coli was identified in 36 (38.7%) of the tested samples. Six strains isolated from different samples harbored the studied genes. Of these 6 isolates, 3 carried the aap gene, 2 the AA probe and the last one the combination of aap/aggR genes. The prevalence of E. coli isolates harboring enteroaggregative virulence genes in groundwater sources was 6.4%. This work represents the first contribution to the study of the presence and distribution of virulence genes of EAEC in groundwater sources in this region of Argentina. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

[Presence of Legionella spp. in household drinking water reservoirs in Resistencia, Chaco, Argentina. Preliminary report].

PubMed

Lösch, Liliana S; Merino, Luis A

Legionella spp. is an environmental bacterium that can survive in a wide range of physicochemical conditions and may colonize distribution systems of drinking water and storage tanks. Legionella pneumophila is the major waterborne pathogen that can cause 90% of Legionnaires' disease cases. The aim of this study was to detect the presence of Legionella spp. in household drinking water tanks in the city of Resistencia, Chaco. The detection of Legionella in water samples was performed by culture methods as set out in ISO 11731:1998. Thirty two water samples were analyzed and Legionella spp. was recovered in 12 (37.5%) of them. The monitoring of this microorganism in drinking water is the first step towards addressing the control of its spread to susceptible hosts. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Ancient maize from Chacoan great houses: Where was it grown?

PubMed Central

Benson, Larry; Cordell, Linda; Vincent, Kirk; Taylor, Howard; Stein, John; Farmer, G. Lang; Futa, Kiyoto

2003-01-01

In this article, we compare chemical (87Sr/86Sr and elemental) analyses of archaeological maize from dated contexts within Pueblo Bonito, Chaco Canyon, New Mexico, to potential agricultural sites on the periphery of the San Juan Basin. The oldest maize analyzed from Pueblo Bonito probably was grown in an area located 80 km to the west at the base of the Chuska Mountains. The youngest maize came from the San Juan or Animas river floodplains 90 km to the north. This article demonstrates that maize, a dietary staple of southwestern Native Americans, was transported over considerable distances in pre-Columbian times, a finding fundamental to understanding the organization of pre-Columbian southwestern societies. In addition, this article provides support for the hypothesis that major construction events in Chaco Canyon were made possible because maize was brought in to support extra-local labor forces. PMID:14563925

Ancient maize from Chacoan great houses: Where was it grown?

USGS Publications Warehouse

Benson, L.; Cordell, L.; Vincent, K.; Taylor, Howard E.; Stein, J.; Farmer, G.L.; Futa, K.

2003-01-01

In this article, we compare chemical (87Sr/86Sr and elemental) analyses of archaeological maize from dated contexts within Pueblo Bonito, Chaco Canyon, New Mexico, to potential agricultural sites on the periphery of the San Juan Basin. The oldest maize analyzed from Pueblo Bonito probably was grown in an area located 80 km to the west at the base of the Chuska Mountains. The youngest maize came from the San Juan or Animas river floodplains 90 km to the north. This article demonstrates that maize, a dietary staple of southwestern Native Americans, was transported over considerable distances in pre-Columbian times, a finding fundamental to understanding the organization of pre-Columbian southwestern societies. In addition, this article provides support for the hypothesis that major construction events in Chaco Canyon were made possible because maize was brought in to support extra-local labor forces.

Experimental Evidence of Biological Interactions among Different Isolates of Trypanosoma cruzi from the Chaco Region

PubMed Central

Ragone, Paula G.; Pérez Brandán, Cecilia; Monje Rumi, Mercedes; Tomasini, Nicolás; Lauthier, Juan J.; Cimino, Rubén O.; Uncos, Alejandro; Ramos, Federico; Alberti D´Amato, Anahí M.; Basombrío, Miguel A.; Diosque, Patricio

2015-01-01

Many infectious diseases arise from co-infections or re-infections with more than one genotype of the same pathogen. These mixed infections could alter host fitness, the severity of symptoms, success in pathogen transmission and the epidemiology of the disease. Trypanosoma cruzi, the etiological agent of Chagas disease, exhibits a high biological variability often correlated with its genetic diversity. Here, we developed an experimental approach in order to evaluate biological interaction between three T. cruzi isolates belonging to different Discrete Typing Units (DTUs TcIII, TcV and TcVI). These isolates were obtained from a restricted geographical area in the Chaco Region. Different mixed infections involving combinations of two isolates (TcIII + TcV, TcIII + TcVI and TcV + TcVI) were studied in a mouse model. The parameters evaluated were number of parasites circulating in peripheral blood, histopathology and genetic characterization of each DTU in different tissues by DNA hybridization probes. We found a predominance of TcVI isolate in blood and tissues respect to TcIII and TcV; and a decrease of the inflammatory response in heart when the damage of mice infected with TcVI and TcIII + TcVI mixture were compared. In addition, simultaneous presence of two isolates in the same tissue was not detected. Our results show that biological interactions between isolates with different biological behaviors lead to changes in their biological properties. The occurrence of interactions among different genotypes of T. cruzi observed in our mouse model suggests that these phenomena could also occur in natural cycles in the Chaco Region. PMID:25789617

mtDNA diversity in Azara's owl monkeys (Aotus azarai azarai) of the Argentinean Chaco.

PubMed

Babb, Paul L; Fernandez-Duque, Eduardo; Baiduc, Caitlin A; Gagneux, Pascal; Evans, Sian; Schurr, Theodore G

2011-10-01

Owl monkeys (Aotus spp.) inhabit much of South America yet represent an enigmatic evolutionary branch among primates. While morphological, cytogenetic, and immunological evidence suggest that owl monkey populations have undergone isolation and diversification since their emergence in the New World, problems with adjacent species ranges, and sample provenance have complicated efforts to characterize genetic variation within the genus. As a result, the phylogeographic history of owl monkey species and subspecies remains unclear, and the extent of genetic diversity at the population level is unknown. To explore these issues, we analyzed mitochondrial DNA (mt DNA) variation in a population of wild Azara's owl monkeys (Aotus azarai azarai) living in the Gran Chaco region of Argentina. We sequenced the complete mitochondrial genome from one individual (16,585 base pairs (bp)) and analyzed 1,099 bp of the hypervariable control region (CR) and 696 bp of the cytochrome oxidase II (COII) gene in 117 others. In addition, we sequenced the mitochondrial genome (16,472 bp) of one Nancy Ma's owl monkey (A. nancymaae). Based on the whole mtDNA and COII data, we observed an ancient phylogeographic discontinuity among Aotus species living north, south, and west of the Amazon River that began more than eight million years ago. Our population analyses identified three major CR lineages and detected a high level of haplotypic diversity within A. a. azarai. These data point to a recent expansion of Azara's owl monkeys into the Argentinean Chaco. Overall, we provide a detailed view of owl monkey mtDNA variation at genus, species, and population levels. Copyright © 2011 Wiley-Liss, Inc.

Geographic variation of Trypanosoma cruzi discrete typing units from Triatoma infestans at different spatial scales.

PubMed

Fernández, María Del Pilar; Cecere, María Carla; Lanati, Leonardo Alejandro; Lauricella, Marta Alicia; Schijman, Alejandro Gabriel; Gürtler, Ricardo Esteban; Cardinal, Marta Victoria

2014-12-01

We assessed the diversity and distribution of Trypanosoma cruzi discrete typing units (DTU) in Triatoma infestans populations and its association with local vector-borne transmission levels at various geographic scales. At a local scale, we found high predominance (92.4%) of TcVI over TcV in 68 microscope-positive T. infestans collected in rural communities in Santiago del Estero province in northern Argentina. TcV was more often found in communities with higher house infestation prevalence compatible with active vector-borne transmission. Humans and dogs were the main bloodmeal sources of the TcV- and TcVI-infected bugs. At a broader scale, the greatest variation in DTU diversity was found within the Argentine Chaco (227 microscope-positive bugs), mainly related to differences in equitability between TcVI and TcV among study areas. At a country-wide level, a meta-analysis of published data revealed clear geographic variations in the distribution of DTUs across countries. A correspondence analysis showed that DTU distributions in domestic T. infestans were more similar within Argentina (dominated by TcVI) and within Bolivia (where TcI and TcV had similar relative frequencies), whereas large heterogeneity was found within Chile. DTU diversity was lower in the western Argentine Chaco region and Paraguay (D=0.14-0.22) than in the eastern Argentine Chaco, Bolivia and Chile (D=0.20-0.68). Simultaneous DTU identifications of T. cruzi-infected hosts and triatomines across areas differing in epidemiological status are needed to shed new light on the structure and dynamics of parasite transmission cycles. Copyright © 2014 Elsevier B.V. All rights reserved.

Epidemiology of and impact of insecticide spraying on Chagas disease in communities in the Bolivian Chaco.

PubMed

Samuels, Aaron M; Clark, Eva H; Galdos-Cardenas, Gerson; Wiegand, Ryan E; Ferrufino, Lisbeth; Menacho, Silvio; Gil, Jose; Spicer, Jennifer; Budde, Julia; Levy, Michael Z; Bozo, Ricardo W; Gilman, Robert H; Bern, Caryn

2013-01-01

Chagas disease control campaigns relying upon residual insecticide spraying have been successful in many Southern American countries. However, in some areas, rapid reinfestation and recrudescence of transmission have occurred. We conducted a cross-sectional survey in the Bolivian Chaco to evaluate prevalence of and risk factors for T. cruzi infection 11 years after two rounds of blanket insecticide application. We used a cubic B-spline model to estimate change in force of infection over time based on age-specific seroprevalence data. Overall T. cruzi seroprevalence was 51.7%. The prevalence was 19.8% among children 2-15, 72.7% among those 15-30 and 97.1% among participants older than 30 years. Based on the model, the estimated annual force of infection was 4.3% over the two years before the first blanket spray in 2000 and fell to 0.4% for 2001-2002. The estimated annual force of infection for 2004-2005, the 2 year period following the second blanket spray, was 4.6%. However, the 95% bootstrap confidence intervals overlap for all of these estimates. In a multivariable model, only sleeping in a structure with cracks in the walls (aOR = 2.35; 95% CI = 1.15-4.78), age and village of residence were associated with infection. As in other areas in the Chaco, we found an extremely high prevalence of Chagas disease. Despite evidence that blanket insecticide application in 2000 may have decreased the force of infection, active transmission is ongoing. Continued spraying vigilance, infestation surveillance, and systematic household improvements are necessary to disrupt and sustain interruption of infection transmission.

Epidemiology of and Impact of Insecticide Spraying on Chagas Disease in Communities in the Bolivian Chaco

PubMed Central

Galdos-Cardenas, Gerson; Wiegand, Ryan E.; Ferrufino, Lisbeth; Menacho, Silvio; Gil, Jose; Spicer, Jennifer; Budde, Julia; Levy, Michael Z.; Bozo, Ricardo W.; Gilman, Robert H.; Bern, Caryn

2013-01-01

Background Chagas disease control campaigns relying upon residual insecticide spraying have been successful in many Southern American countries. However, in some areas, rapid reinfestation and recrudescence of transmission have occurred. Methodology/Principal Findings We conducted a cross-sectional survey in the Bolivian Chaco to evaluate prevalence of and risk factors for T. cruzi infection 11 years after two rounds of blanket insecticide application. We used a cubic B-spline model to estimate change in force of infection over time based on age-specific seroprevalence data. Overall T. cruzi seroprevalence was 51.7%. The prevalence was 19.8% among children 2–15, 72.7% among those 15–30 and 97.1% among participants older than 30 years. Based on the model, the estimated annual force of infection was 4.3% over the two years before the first blanket spray in 2000 and fell to 0.4% for 2001–2002. The estimated annual force of infection for 2004–2005, the 2 year period following the second blanket spray, was 4.6%. However, the 95% bootstrap confidence intervals overlap for all of these estimates. In a multivariable model, only sleeping in a structure with cracks in the walls (aOR = 2.35; 95% CI = 1.15–4.78), age and village of residence were associated with infection. Conclusions/Significance As in other areas in the Chaco, we found an extremely high prevalence of Chagas disease. Despite evidence that blanket insecticide application in 2000 may have decreased the force of infection, active transmission is ongoing. Continued spraying vigilance, infestation surveillance, and systematic household improvements are necessary to disrupt and sustain interruption of infection transmission. PMID:23936581

Photometric Assessment of Night Sky Quality over Chaco Culture National Historical Park

NASA Astrophysics Data System (ADS)

Hung, Li-Wei; Duriscoe, Dan M.; White, Jeremy M.; Meadows, Bob; Anderson, Sharolyn J.

2018-06-01

The US National Park Service (NPS) characterizes night sky conditions over Chaco Culture National Historical Park using measurements in the park and satellite data. The park is located near the geographic center of the San Juan Basin of northwestern New Mexico and the adjacent Four Corners state. In the park, we capture a series of night sky images in V-band using our mobile camera system on nine nights from 2001 to 2016 at four sites. We perform absolute photometric calibration and determine the image placement to obtain multiple 45-million-pixel mosaic images of the entire night sky. We also model the regional night sky conditions in and around the park based on 2016 VIIRS satellite data. The average zenith brightness is 21.5 mag/arcsec2, and the whole sky is only ~16% brighter than the natural conditions. The faintest stars visible to naked eyes have magnitude of approximately 7.0, reaching the sensitivity limit of human eyes. The main impacts to Chaco’s night sky quality are the light domes from Albuquerque, Rio Rancho, Farmington, Bloomfield, Gallup, Santa Fe, Grants, and Crown Point. A few of these light domes exceed the natural brightness of the Milky Way. Additionally, glare sources from oil and gas development sites are visible along the north and east horizons. Overall, the night sky quality at Chaco Culture National Historical Park is very good. The park preserves to a large extent the natural illumination cycles, providing a refuge for crepuscular and nocturnal species. During clear and dark nights, visitors have an opportunity to see the Milky Way from nearly horizon to horizon, complete constellations, and faint astronomical objects and natural sources of light such as the Andromeda Galaxy, zodiacal light, and airglow.

Soil moisture and excavation behaviour in the Chaco leaf-cutting ant (Atta vollenweideri): digging performance and prevention of water inflow into the nest.

PubMed

Pielström, Steffen; Roces, Flavio

2014-01-01

The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed.

STS-55 Earth observation of agricultural development in northern Argentina

NASA Technical Reports Server (NTRS)

1993-01-01

STS-55 Earth observation taken aboard Columbia, Orbiter Vehicle (OV) 102, is of agricultural development in northern Argentina. This photograph is from a mapping strip of photographs acquired by the STS-55 crew. This mapping strip runs from the 'eyelash forests' of the Bolivian Andes, southeast across the Chaco Plains, and into the upper Parana River Basin of north-central Argentina. The formerly densely forested areas between the upper Rio Pilcomayo and the Rio Teuco of NW Argentina rest on deep, rich alluvial and loess deposits. These modern soils were carried into the region by rivers from the Andes and by dust storms from large playa areas of the Altiplano (high plains) of Peru and Boliva. In this scene, representative of the long mapping strip, the process of converting forests to agriculture is far advanced. The original road network, a series of grids laid out in the forest, has nearly coalesced into a farm and ranch landscape. Some few relict forests are still visible as distin

[Water and health-related problems, local perception and quality of water sources in a Toba (qom) community in the Impenetrable (Chaco, Argentina)].

PubMed

Martínez, Gustavo J; Beccaglia, Ana M; Llinares, Analía

2014-08-01

We present a transdisciplinary study centering on aspects of environmental health of the Toba (qom) communities that relate to water and health problems of the Impenetrable Chaco region. Information was obtained through the methods and tools of participatory research, household participant observation, and ethnobotanical documentation of species related to water management and use. Vernacular terms referring to the suitability and taste of the water, as well as representations, attitudes and practices related to water collection and purification were recorded. In addition, a microbiological and physicochemical analysis of the water was performed and compared with the perceptual categories. It was observed that perceptual aspects were in tension with the hygienic quality of water. We documented phreatophyte plants, indicative of the presence of water, as well as plants that store water, act as flocculants, refresh the water or improve taste. The results of this research are discussed from an ecosystem approach and its relationship to the development of proposals for intervention.

Evidence of cacao use in the Prehispanic American Southwest

PubMed Central

Crown, Patricia L.; Hurst, W. Jeffrey

2009-01-01

Chemical analyses of organic residues in fragments of ceramic vessels from Pueblo Bonito in Chaco Canyon, New Mexico, reveal theobromine, a biomarker for cacao. With an estimated 800 rooms, Pueblo Bonito is the largest archaeological site in Chaco Canyon and was the center of a large number of interconnected towns and villages spread over northwestern New Mexico. The cacao residues come from pieces of vessels that are likely cylinder jars, special containers occurring almost solely at Pueblo Bonito and deposited in caches at the site. This first known use of cacao drinks north of the Mexican border indicates exchange with cacao cultivators in Mesoamerica in a time frame of about A.D. 1000–1125. The association of cylinder jars and cacao beverages suggests that the Chacoan ritual involving the drinking of cacao was tied to Mesoamerican rituals incorporating cylindrical vases and cacao. The importance of Pueblo Bonito within the Chacoan world likely lies in part with the integration of Mesoamerican ritual, including critical culinary ingredients. PMID:19188605

The freshwater lens of Benjamín Aceval, Chaco, Paraguay: a terrestrial analogue of an oceanic island lens

NASA Astrophysics Data System (ADS)

Houben, Georg; Noell, Ursula; Vassolo, Sara; Grissemann, Christoph; Geyh, Mebus; Stadler, Susanne; Dose, Eduardo J.; Vera, Sofia

2014-12-01

The occurrence of a freshwater lens in the Paraguayan Chaco, 900 km away from the ocean, is reported. It is located underneath sandstone hills, surrounded by lowlands with predominantly saline groundwater. Its geometry was delineated using geoelectrical and electromagnetic investigations. The unusual height of the fresh groundwater level can be attributed to the presence of a confining layer at depth. The lens receives its recharge exclusively from rainfall during the hot and humid summer months. It predominantly contains water predating the atmospheric atomic bomb tests, some of it probably up to a thousand or more years old. The water balance shows that extraction currently does not exceed recharge in normal years. However, the available volume of groundwater leaves little room for a further increase of extraction in the future. Recharge is augmented by return flow from thousands of latrines and cess pits, and this has lead to widespread contamination of the groundwater by faecal bacteria.

Do Wildfires Promote Woody Species Invasion in a Fire-Adapted Ecosystem? Post-fire Resprouting of Native and Non-native Woody Plants in Central Argentina.

PubMed

Herrero, M Lucrecia; Torres, Romina C; Renison, Daniel

2016-02-01

We asked whether prescribed fire could be a useful management tool to reduce invasion by non-native plants in an ecosystem where native plants are supposed to be adapted to fires. Specifically, we compare the post-fire resprouting response of native and non-native woody species in Chaco Serrano forest of central Argentina. The measurements were carried out in five burnt areas where we selected ten native and seven non-native species. Our response variables were (1) post-fire survival, (2) types of resprouts, and (3) the growth of the resprouts. Our main results show that one year after the fire, survivals of native and non-native species were 0.84 and 0.89, respectively, with variances in survival seven times smaller in the native species group. Type of resprout was also less variable in native species, while growth of the resprouts was similar in native and non-native groups. We interpret that in most cases, the burning a forest with mixed native and non-native plants through prescribed fires will not differentially stop the invasion by non-native woody species even in ecosystems which are presumed to be relatively resistant to fires such as our study area.

Recognition of Culex Bidens Dyar and Culex Interfor Dyar (Diptera: Culicidae) as Separate Species

DTIC Science & Technology

1986-01-01

genitalia. ARGENTINA. Corrientes : locality not specified, 6 specimens. Jujuy: Ledesma, 1 specimen. Santa fe: Calchaqui’, 1 specimen; Humboldt, 2 specimens...close to surface of lateral plate. MATERIAL EXAHINED: 42 male genitalia. ARGENTINA. Chaco: locality not specified, 2 specimens. Corrientes

Environmental drivers of anuran calling phenology in a seasonal neotropical ecosystem

Treesearch

Christopher M. Schalk; Dan Saenz

2015-01-01

Temporal variation represents an important component in understanding the structure of ecological communities and species coexistence. We examined calling phenology of an assemblage of anurans in the Gran Chaco ecoregion of Bolivia by deploying automated recording devices to document nocturnally vocalizing amphibians nightly at seven...

Over Six Thousand Trypanosoma cruzi Strains Classified into Discrete Typing Units (DTUs): Attempt at an Inventory.

PubMed

Brenière, Simone Frédérique; Waleckx, Etienne; Barnabé, Christian

2016-08-01

Trypanosoma cruzi, the causative agent of Chagas disease, presents wide genetic diversity. Currently, six discrete typing units (DTUs), named TcI to TcVI, and a seventh one called TcBat are used for strain typing. Beyond the debate concerning this classification, this systematic review has attempted to provide an inventory by compiling the results of 137 articles that have used it. A total of 6,343 DTU identifications were analyzed according to the geographical and host origins. Ninety-one percent of the data available is linked to South America. This sample, although not free of potential bias, nevertheless provides today's picture of T. cruzi genetic diversity that is closest to reality. DTUs were genotyped from 158 species, including 42 vector species. Remarkably, TcI predominated in the overall sample (around 60%), in both sylvatic and domestic cycles. This DTU known to present a high genetic diversity, is very widely distributed geographically, compatible with a long-term evolution. The marsupial is thought to be its most ancestral host and the Gran Chaco region the place of its putative origin. TcII was rarely sampled (9.6%), absent, or extremely rare in North and Central America, and more frequently identified in domestic cycles than in sylvatic cycles. It has a low genetic diversity and has probably found refuge in some mammal species. It is thought to originate in the south-Amazon area. TcIII and TcIV were also rarely sampled. They showed substantial genetic diversity and are thought to be composed of possible polyphyletic subgroups. Even if they are mostly associated with sylvatic transmission cycles, a total of 150 human infections with these DTUs have been reported. TcV and TcVI are clearly associated with domestic transmission cycles. Less than 10% of these DTUs were identified together in sylvatic hosts. They are thought to originate in the Gran Chaco region, where they are predominant and where putative parents exist (TcII and TcIII). Trends in host-DTU specificities exist, but generally it seems that the complexity of the cycles and the participation of numerous vectors and mammal hosts in a shared area, maintains DTU diversity.

Human Babesiosis, Bolivia, 2013.

PubMed

Gabrielli, Simona; Totino, Valentina; Macchioni, Fabio; Zuñiga, Freddy; Rojas, Patricia; Lara, Yuni; Roselli, Mimmo; Bartoloni, Alessandro; Cancrini, Gabriella

2016-08-01

To investigate human babesiosis in the Bolivian Chaco, in 2013 we tested blood samples from 271 healthy persons living in 2 rural communities in this region. Microscopy and PCR indicated that 3.3% of persons were positive for Babesia microti parasites (US lineage); seroprevalence was 45.7%. Appropriate screening should mitigate the risk for transfusion-associated babesiosis.

"Inhabitants of the Earth": Reasoning about Folkbiological Concepts in Wichi Children and Adults

ERIC Educational Resources Information Center

Taverna, Andrea S.; Medin, Douglas L.; Waxman, Sandra R.

2016-01-01

Across the world, people form folkbiological categories to capture their commonsense organization of the natural world. Structured in accordance with universal principles, folkbiological categories are also shaped by experience. Here we provide new evidence from the Wichi--an understudied indigenous community who live in the Chaco rainforest and…

Language Dispute and Social Change in New Multilingual Institutions in Chaco, Argentina

ERIC Educational Resources Information Center

Unamuno, Virginia

2014-01-01

Intercultural bilingual education (IBE) programmes in Latin America pose interesting questions for sociolinguistics, since their implementation interrogates the link between language and the nation resulting from the emergence of nation-states, but also from processes of decolonization. In the case of Argentina, a new legal framework and the…

Trees, chemistry, and prehistory in the American Southwest

USGS Publications Warehouse

Durand, S.R.; Shelley, P.H.; Antweiler, Ronald C.; Taylor, Howard E.

1999-01-01

At least 200 000 trees were used in the building construction in Chaco Canyon, New Mexico, from about (AD) 850-1150. A large portion of these construction timbers were transported 50 km or more and the harvesting location(s) is not known. We argue that a feasible method for determining the wood source areas is to chemically characterize the possible source areas using modern wood and then attempt to match the prehistoric timbers to the modern signatures. This paper establishes the feasibility of this method. ICP-AES was employed to obtain element concentration values for 29 elements, from 62 trees, on three bedrock types. We conclude that it is possible to isolate the variation due to lithology if one controls for wood type (bark, sapwood, heartwood). In addition, ICP-MS was used for the analysis of a small sample of ancient wood. Data from these determinations are presented and the results indicate that the elemental variation is consistent with the most current model of wood use practices in Chaco Canyon. The methods pioneered here should be broadly applicable for determining wood source areas.

Effects of the herbicide glyphosate on non-target plant native species from Chaco forest (Argentina).

PubMed

Florencia, Ferreira María; Carolina, Torres; Enzo, Bracamonte; Leonardo, Galetto

2017-10-01

Agriculture based on transgenic crops has expanded in Argentina into areas formerly occupied by Chaco forest. Even though glyphosate is the herbicide most widely used in the world, increasing evidence indicates severe ecotoxicological effects on non-target organisms as native plants. The aim of this work is to determine glyphosate effects on 23 native species present in the remaining Chaco forests immersed in agricultural matrices. This is a laboratory/greenhouse approach studying acute effects on seedlings after 21 days. A gradient of glyphosate rates (525, 1050, 2100, 4200, and 8400g ai/Ha; recommended field application rate (RFAR) = 2100g ai/Ha) was applied on four-week seedlings cultivated in a greenhouse and response variables (phytotoxicity, growth reduction, and sensitivity to the herbicide) were measured. This gradient of herbicide rates covers realistic rates of glyphosate applications in the crop field and also those that can reach vegetation of forest relicts by off-target drift and overspray. Testing was performed following guidelines for vegetative vigour (post-germination spray). All species showed lethal or sublethal effects after the application of the 25% of RFAR (50% of species showed severe phytotoxicity or death and 70% of species showed growth reduction). The results showed a gradient of sensitivity to glyphosate by which some of the studied species are very sensitive to glyphosate and seedlings died with 25% of RFAR while other species can be classified as herbicide-tolerant. Thus, the vegetation present in the forest relicts could be strongly affected by glyphosate application on crops. Lethal and sublethal effects of glyphosate on non-target plants could promote both the loss of biodiversity in native forest relicts immersed in the agroecosystems and the selection of new crop weeds considering that some biotypes are continuously exposed to low doses of glyphosate. Copyright © 2017 Elsevier Inc. All rights reserved.

Factors Affecting Infestation by Triatoma infestans in a Rural Area of the Humid Chaco in Argentina: A Multi-Model Inference Approach

PubMed Central

Gurevitz, Juan M.; Ceballos, Leonardo A.; Gaspe, María Sol; Alvarado-Otegui, Julián A.; Enríquez, Gustavo F.; Kitron, Uriel; Gürtler, Ricardo E.

2011-01-01

Background Transmission of Trypanosoma cruzi by Triatoma infestans remains a major public health problem in the Gran Chaco ecoregion, where understanding of the determinants of house infestation is limited. We conducted a cross-sectional study to model factors affecting bug presence and abundance at sites within house compounds in a well-defined rural area in the humid Argentine Chaco. Methodology/Principal Findings Triatoma infestans bugs were found in 45.9% of 327 inhabited house compounds but only in 7.4% of the 2,584 sites inspected systematically on these compounds, even though the last insecticide spraying campaign was conducted 12 years before. Infested sites were significantly aggregated at distances of 0.8–2.5 km. The most frequently infested ecotopes were domiciles, kitchens, storerooms, chicken coops and nests; corrals were rarely infested. Domiciles with mud walls and roofs of thatch or corrugated tarred cardboard were more often infested (32.2%) than domiciles with brick-and-cement walls and corrugated metal-sheet roofs (15.1%). A multi-model inference approach using Akaike's information criterion was applied to assess the relative importance of each variable by running all possible (17,406) models resulting from all combinations of variables. Availability of refuges for bugs, construction with tarred cardboard, and host abundance (humans, dogs, cats, and poultry) per site were positively associated with infestation and abundance, whereas reported insecticide use showed a negative association. Ethnic background (Creole or Toba) adjusted for other factors showed little or no association. Conclusions/Significance Promotion and effective implementation of housing improvement (including key peridomestic structures) combined with appropriate insecticide use and host management practices are needed to eliminate infestations. Fewer refuges are likely to result in fewer residual foci after insecticide spraying, and will facilitate community-based vector surveillance. A more integrated perspective that considers simultaneously social, economic and biological processes at local and regional scales is needed to attain effective, sustainable vector and disease control. PMID:22028941

Factors affecting infestation by Triatoma infestans in a rural area of the humid Chaco in Argentina: a multi-model inference approach.

PubMed

Gurevitz, Juan M; Ceballos, Leonardo A; Gaspe, María Sol; Alvarado-Otegui, Julián A; Enríquez, Gustavo F; Kitron, Uriel; Gürtler, Ricardo E

2011-10-01

Transmission of Trypanosoma cruzi by Triatoma infestans remains a major public health problem in the Gran Chaco ecoregion, where understanding of the determinants of house infestation is limited. We conducted a cross-sectional study to model factors affecting bug presence and abundance at sites within house compounds in a well-defined rural area in the humid Argentine Chaco. Triatoma infestans bugs were found in 45.9% of 327 inhabited house compounds but only in 7.4% of the 2,584 sites inspected systematically on these compounds, even though the last insecticide spraying campaign was conducted 12 years before. Infested sites were significantly aggregated at distances of 0.8-2.5 km. The most frequently infested ecotopes were domiciles, kitchens, storerooms, chicken coops and nests; corrals were rarely infested. Domiciles with mud walls and roofs of thatch or corrugated tarred cardboard were more often infested (32.2%) than domiciles with brick-and-cement walls and corrugated metal-sheet roofs (15.1%). A multi-model inference approach using Akaike's information criterion was applied to assess the relative importance of each variable by running all possible (17,406) models resulting from all combinations of variables. Availability of refuges for bugs, construction with tarred cardboard, and host abundance (humans, dogs, cats, and poultry) per site were positively associated with infestation and abundance, whereas reported insecticide use showed a negative association. Ethnic background (Creole or Toba) adjusted for other factors showed little or no association. Promotion and effective implementation of housing improvement (including key peridomestic structures) combined with appropriate insecticide use and host management practices are needed to eliminate infestations. Fewer refuges are likely to result in fewer residual foci after insecticide spraying, and will facilitate community-based vector surveillance. A more integrated perspective that considers simultaneously social, economic and biological processes at local and regional scales is needed to attain effective, sustainable vector and disease control.

Soil Moisture and Excavation Behaviour in the Chaco Leaf-Cutting Ant (Atta vollenweideri): Digging Performance and Prevention of Water Inflow into the Nest

PubMed Central

Pielström, Steffen; Roces, Flavio

2014-01-01

The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed. PMID:24748382

Hidden Sylvatic Foci of the Main Vector of Chagas Disease Triatoma infestans: Threats to the Vector Elimination Campaign?

PubMed Central

Schachter-Broide, Judith; Dujardin, Jean-Pierre; Dotson, Ellen M.; Kitron, Uriel; Gürtler, Ricardo E.

2011-01-01

Background Establishing the sources of reinfestation after residual insecticide spraying is crucial for vector elimination programs. Triatoma infestans, traditionally considered to be limited to domestic or peridomestic (abbreviated as D/PD) habitats throughout most of its range, is the target of an elimination program that has achieved limited success in the Gran Chaco region in South America. Methodology/Principal Findings During a two-year period we conducted semi-annual searches for triatomine bugs in every D/PD site and surrounding sylvatic habitats after full-coverage spraying of pyrethroid insecticides of all houses in a well-defined rural area in northwestern Argentina. We found six low-density sylvatic foci with 24 T. infestans in fallen or standing trees located 110–2,300 m from the nearest house or infested D/PD site detected after insecticide spraying, when house infestations were rare. Analysis of two mitochondrial gene fragments of 20 sylvatic specimens confirmed their species identity as T. infestans and showed that their composite haplotypes were the same as or closely related to D/PD haplotypes. Population studies with 10 polymorphic microsatellite loci and wing geometric morphometry consistently indicated the occurrence of unrestricted gene flow between local D/PD and sylvatic populations. Mitochondrial DNA and microsatellite sibship analyses in the most abundant sylvatic colony revealed descendents from five different females. Spatial analysis showed a significant association between two sylvatic foci and the nearest D/PD bug population found before insecticide spraying. Conclusions Our study shows that, despite of its high degree of domesticity, T. infestans has sylvatic colonies with normal chromatic characters (not melanic morphs) highly connected to D/PD conspecifics in the Argentinean Chaco. Sylvatic habitats may provide a transient or permanent refuge after control interventions, and function as sources for D/PD reinfestation. The occurrence of sylvatic foci of T. infestans in the Gran Chaco may pose additional threats to ongoing vector elimination efforts. PMID:22039559

Application of techniques to identify coal-mine and power-generation effects on surface-water quality, San Juan River basin, New Mexico and Colorado

USGS Publications Warehouse

Goetz, C.L.; Abeyta, Cynthia G.; Thomas, E.V.

1987-01-01

Numerous analytical techniques were applied to determine water quality changes in the San Juan River basin upstream of Shiprock , New Mexico. Eight techniques were used to analyze hydrologic data such as: precipitation, water quality, and streamflow. The eight methods used are: (1) Piper diagram, (2) time-series plot, (3) frequency distribution, (4) box-and-whisker plot, (5) seasonal Kendall test, (6) Wilcoxon rank-sum test, (7) SEASRS procedure, and (8) analysis of flow adjusted, specific conductance data and smoothing. Post-1963 changes in dissolved solids concentration, dissolved potassium concentration, specific conductance, suspended sediment concentration, or suspended sediment load in the San Juan River downstream from the surface coal mines were examined to determine if coal mining was having an effect on the quality of surface water. None of the analytical methods used to analyzed the data showed any increase in dissolved solids concentration, dissolved potassium concentration, or specific conductance in the river downstream from the mines; some of the analytical methods used showed a decrease in dissolved solids concentration and specific conductance. Chaco River, an ephemeral stream tributary to the San Juan River, undergoes changes in water quality due to effluent from a power generation facility. The discharge in the Chaco River contributes about 1.9% of the average annual discharge at the downstream station, San Juan River at Shiprock, NM. The changes in water quality detected at the Chaco River station were not detected at the downstream Shiprock station. It was not possible, with the available data, to identify any effects of the surface coal mines on water quality that were separable from those of urbanization, agriculture, and other cultural and natural changes. In order to determine the specific causes of changes in water quality, it would be necessary to collect additional data at strategically located stations. (Author 's abstract)

Ecological and Sociodemographic Determinants of House Infestation by Triatoma infestans in Indigenous Communities of the Argentine Chaco

PubMed Central

Gaspe, M. Sol; Provecho, Yael M.; Cardinal, M. Victoria; del Pilar Fernández, M.; Gürtler, Ricardo E.

2015-01-01

Background The Gran Chaco ecoregion, a hotspot for Chagas and other neglected tropical diseases, is home to >20 indigenous peoples. Our objective was to identify the main ecological and sociodemographic determinants of house infestation and abundance of Triatoma infestans in traditional Qom populations including a Creole minority in Pampa del Indio, northeastern Argentina. Methods A cross-sectional survey determined house infestation by timed-manual searches with a dislodging aerosol in 386 inhabited houses and administered questionnaires on selected variables before full-coverage insecticide spraying and annual vector surveillance. We fitted generalized linear models to two global models of domestic infestation and bug abundance, and estimated coefficients via multimodel inference with model averaging. Principal Findings Most Qom households were larger and lived in small-sized, recently-built, precarious houses with fewer peridomestic structures, and fewer livestock and poultry than Creoles’. Qom households had lower educational level and unexpectedly high residential mobility. House infestation (31.9%) was much lower than expected from lack of recent insecticide spraying campaigns and was spatially aggregated. Nearly half of the infested houses examined had infected vectors. Qom households had higher prevalence of domestic infestation (29.2%) than Creoles’ (10.0%), although there is large uncertainty around the adjusted OR. Factors with high relative importance for domestic infestation and/or bug abundance were refuge availability, distance to the nearest infested house, domestic insecticide use, indoor presence of poultry, residential overcrowding, and household educational level. Conclusions and Significance Our study highlights the importance of sociodemographic determinants of domestic infestation such as overcrowding, education and proximity to the nearest infested house, and corroborates the role of refuge availability, domestic use of insecticides and household size. These factors may be used for designing improved interventions for sustainable disease control and risk stratification. Housing instability, household mobility and migration patterns are key to understanding the process of house (re)infestation in the Gran Chaco. PMID:25785439

Ecological and sociodemographic determinants of house infestation by Triatoma infestans in indigenous communities of the Argentine Chaco.

PubMed

Sol Gaspe, M; Provecho, Yael M; Cardinal, M Victoria; del Pilar Fernández, M; Gürtler, Ricardo E

2015-03-01

The Gran Chaco ecoregion, a hotspot for Chagas and other neglected tropical diseases, is home to >20 indigenous peoples. Our objective was to identify the main ecological and sociodemographic determinants of house infestation and abundance of Triatoma infestans in traditional Qom populations including a Creole minority in Pampa del Indio, northeastern Argentina. A cross-sectional survey determined house infestation by timed-manual searches with a dislodging aerosol in 386 inhabited houses and administered questionnaires on selected variables before full-coverage insecticide spraying and annual vector surveillance. We fitted generalized linear models to two global models of domestic infestation and bug abundance, and estimated coefficients via multimodel inference with model averaging. Most Qom households were larger and lived in small-sized, recently-built, precarious houses with fewer peridomestic structures, and fewer livestock and poultry than Creoles'. Qom households had lower educational level and unexpectedly high residential mobility. House infestation (31.9%) was much lower than expected from lack of recent insecticide spraying campaigns and was spatially aggregated. Nearly half of the infested houses examined had infected vectors. Qom households had higher prevalence of domestic infestation (29.2%) than Creoles' (10.0%), although there is large uncertainty around the adjusted OR. Factors with high relative importance for domestic infestation and/or bug abundance were refuge availability, distance to the nearest infested house, domestic insecticide use, indoor presence of poultry, residential overcrowding, and household educational level. Our study highlights the importance of sociodemographic determinants of domestic infestation such as overcrowding, education and proximity to the nearest infested house, and corroborates the role of refuge availability, domestic use of insecticides and household size. These factors may be used for designing improved interventions for sustainable disease control and risk stratification. Housing instability, household mobility and migration patterns are key to understanding the process of house (re)infestation in the Gran Chaco.

Depths of channels in the area of the San Juan Basin Regional Uranium Study, New Mexico, Colorado, Arizona, and Utah

USGS Publications Warehouse

Cooley, Maurice E.

1979-01-01

During December 1977 and January 1978 about 280 measurements were made of the depths of channels (arroyos) more than 6 feet deep in the San Juan Basin area. More than half of the measurements were made at sites where channel depths had been previously measured Between 1964 and 1969. Some channels in the western part of the basin had Been re-measured in 1969 and in 1971. The principal areas Being dissected by arroyos are near highlands along the margins of the Basin and in uplands in the northeastern part of the Basin. The most severe dissection by arroyos and the deepest arroyos--commonly Between 40 and 60 feet deep--are in the southeastern part of the Basin. Dissection By arroyos is least in the central part of the Basin near the Chaco River where most arroyos are less than 10 feet deep. Elsewhere, moderate dissection predominates with most arroyos Between 12 and 40 feet deep. Comparison of measurements made from 1964-71 with those made in 1977-78 shows that more channels in the western San Juan Basin were filling than were downcutting. Downcutting or filling was generally less than 2 feet. About two-fifths of the sites measured showed less than half a foot of downcutting or filling. Maximum downcutting was 4 feet along the Rio San Jose in the southeastern part of the basin. Maximum filling of 7 feet was along the Chaco River at the Chaco Canyon National Monument. Along ii other streams elsewhere in the western part of the basin, channels were filled 3 to 4.5 feet. The few measurements made in the southeastern San Juan Basin indicate that since 1964 downcutting has predominated over filling. Large floods during the summer of 1977 caused some change in channel depths in the southwestern part of the San Juan Basin. Some of the channels appeared to have been filled during the years prior to the cutting that occurred from the 1977 floods. At other places, flood flows aggraded (filled) channels. The rate of erosion and arroyo formation in the entire San Juan Basin is effected by man. The southeastern part of the basin--having been occupied by man for several centuries--shows the greatest effects of man on the rate of arroyo formation. Recent urban developments, particularly near Gallup, also appear to have affected the rate of erosion and arroyo formation. In contrast, arroyos appear to be aggrading below many earth-fill dams. In general, the effects of the petroleum, coal, and uranium exploration and development on arroyo formation have been minimal because the main trenching of the arroyos predates oil and mining operations. Some modification--degradation or aggradation--of the arroyos and local trenching of new arroyos have taken place in the area of some of the mines. Most of the observed effects from the mining operations on erosion and aggradation relate to the discharge of mine and mill water into the nearby streams.

77 FR 73475 - Changes in Flood Hazard Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-10

...- December 24, 2012 270156 (12-05-1144P). ReNae Bowman, Douglas Drive team.com/starr/ Mayor, City of North, Crystal, LOMR/Pages/ Crystal, 4141 MN 55422. RegionV.aspx. Douglas Drive North, Crystal, MN 55422. Nevada... Grand Las Vegas, NV Central Parkway, 89155. Las Vegas, NV 89155. Douglas Unincorporated The Honorable...

Evolución de estrellas de Helio

NASA Astrophysics Data System (ADS)

Panei, J. A.; Benvenuto, O. G.; Althaus, L. G.

Podríamos identificar a las estrellas de helio con estrellas Wolf-Rayet (WR) que han perdido su envoltura rica en hidrógeno ya sea porque las mismas pertenecen a sistemas binarios o a través de fuertes vientos estelares. Las WR representan una etapa evolucionaria normal de las estrellas masivas, cuya pérdida de masa es >= 3 × 10-5Msolar/yr y la cual es sufrida por la estrella en un tiempo de escala mucho menor que el tiempo en que se produce la quema del He. Esto garantiza la ``homogeneidad'' de las estrellas de helio para nuestros modelos. Este tipo de estrellas serían posibles progenitores de SN tipo Ib y Ic. Aquí presentamos un estudio sobre la evolución de estrellas de helio a partir de la secuencia principal de helio, pasando por el flash de carbono, hasta agotarlo en la región central; como así también la dependencia con la variable masa y con la pérdida de la misma para distintos tipos de masas. Para tal fin hemos utilizado un código de evolución estelar completo que realiza todas las reacciones de Fowler en forma simultánea. También se han tenido en cuenta los procesos de mezcla convectiva, los principales mecanismos de emisión de neutrinos y los efectos de la pérdida de masa. Las opacidades utilizadas fueron las de Rogers & Iglesias (1992). Debido a la pérdida de masa en este tipo de estrellas, hemos encontrado que los perfiles convectivos, la composición química, las condiciones centrales de temperatura y presión, luminosidad y temperatura efectiva dependen en forma esencial de la velocidad de pérdida de masa adoptada, lo que tendría profundas implicaciones en la evolución posterior de estos objetos.

Log ASCII Standard (LAS) Files for Geophysical Wireline Well Logs and Their Application to Geologic Cross Sections Through the Central Appalachian Basin

USGS Publications Warehouse

Crangle, Robert D.

2007-01-01

Introduction The U.S. Geological Survey (USGS) uses geophysical wireline well logs for a variety of purposes, including stratigraphic correlation (Hettinger, 2001, Ryder, 2002), petroleum reservoir analyses (Nelson and Bird, 2005), aquifer studies (Balch, 1988), and synthetic seismic profiles (Kulander and Ryder, 2005). Commonly, well logs are easier to visualize, manipulate, and interpret when available in a digital format. In recent geologic cross sections E-E' and D-D', constructed through the central Appalachian basin (Ryder, Swezey, and others, in press; Ryder, Crangle, and others, in press), gamma ray well log traces and lithologic logs were used to correlate key stratigraphic intervals (Fig. 1). The stratigraphy and structure of the cross sections are illustrated through the use of graphical software applications (e.g., Adobe Illustrator). The gamma ray traces were digitized in Neuralog (proprietary software) from paper well logs and converted to a Log ASCII Standard (LAS) format. Once converted, the LAS files were transformed to images through an LAS-reader application (e.g., GeoGraphix Prizm) and then overlain in positions adjacent to well locations, used for stratigraphic control, on each cross section. This report summarizes the procedures used to convert paper logs to a digital LAS format using a third-party software application, Neuralog. Included in this report are LAS files for sixteen wells used in geologic cross section E-E' (Table 1) and thirteen wells used in geologic cross section D-D' (Table 2).

Líneas metálicas en protuberancias solares

NASA Astrophysics Data System (ADS)

Stenborg, G.; Rovira, M. G.; Mauas, P.

Para determinar cual de los modelos existentes de protuberancias solares explica mejor las observaciones, es necesario, no solo ajustar los perfiles de las líneas de hidrógeno, sino también utilizar perfiles de distintos metales. En este trabajo, utilizamos un código desarrollado especialmente para calcular el equilibrio estadístico de cualquier especie atómica, aplicándolo al cálculo de los perfiles de las líneas del Ca II, el Mg II y el He, para determinar cómo se comportan ante variaciones en los parámetros de los modelos de protuberancia (ancho, presión y temperatura centrales y número de hebras), y comparamos con las observaciones existentes para determinar que modelo las ajusta mejor.

What I Learned about Higher Ed Assessment in a Small Village in South America

ERIC Educational Resources Information Center

Occhipinti, Laurie

2016-01-01

Does assessment change what is being taught? Laurie Occhipinti uses an analogy to answer this question. While conducting research on economic development in a remote rural area of the Argentine Chaco, a community had received some public funds to construct a new community center. They discussed where to place the center. The middle of the village…

The groundwater subsidy to vegetation: groundwater exchanges between landcover patches

NASA Astrophysics Data System (ADS)

Steven, L. I.; Gimenez, R.; Jobbagy, E. G.

2015-12-01

The Gran Chaco is a hot, dry plain, that spans over 60 million hectares across Bolivia, Paraguay, Brazil and Argentina. It supports high biodiversity in its dry forest and savannahs, but is rapidly being converted to agriculture in response to growing soy demand and technology including genetic modification and zero-till, that has made cultivation in drier landscapes more viable. Under natural conditions, the deep-rooted, native vegetation of the Chaco effectively captured all rainfall for evapotranspiration resulting in near zero groundwater recharge under the dry forest. Conversion to shallower rooted soy and corn, combined with the fallow period prior to the growing season, reduces evapotranspiration and allows some water to percolate through the root zone and recharge the groundwater system. When this groundwater recharge occurs, it creates groundwater mounding and a hydraulic gradient that drives flow to adjacent landcover patches where recharge does not occur. As the watertable rises, groundwater becomes available to the deep-rooted, dry forest vegetation. We develop a soil and groundwater flow model to simulate infiltration, percolation, evaporation, rootwater uptake, groundwater recharge and the lateral transfer of water between adjacent landcover patches to quantify this groundwater subsidy from converted agricultural lands to remnant patches of dry forest.

Centers of control: Revealing elites among the Ancestral Pueblo during the "Chaco Phenomenon".

PubMed

Harrod, Ryan P

The use of violence as a means of social control among higher status members of the Ancestral Pueblo is explored by using data derived from the burials and the burial context of several sites between AD 850 and 1300. High-status burials, while relatively rare in the archeological record, are of interest because of the role the individuals are assumed to have played in the culture. It has been suggested that there were "elites" among the Ancestral Pueblo during a particularly volatile period that corresponds with the growth, development, and decline of Chacon Canyon and to a lesser extent Aztec Ruins, two major political and ritual centers. Using a bioarchaeological approach that integrates the human remains with the archeological context, burials from Chaco Canyon were compared with burials from other sites in the region based on demographic (age and sex), nutritional (stature), activity (robusticity and entheses), health (pathological conditions), violence (cranial trauma), and cultural (mortuary pattern) patterns. Crucial for expanding our understanding of the role of hierarchy and social control in the Pueblo world, these data suggest that there were high-status individuals who functioned as political and ceremonial leaders. Copyright © 2012 Elsevier Inc. All rights reserved.

Sustainability of vector control strategies in the Gran Chaco Region: current challenges and possible approaches

PubMed Central

Gürtler, Ricardo E

2011-01-01

Sustainability has become a focal point of the international agenda. At the heart of its range of distribution in the Gran Chaco Region, the elimination of Triatoma infestans has failed, even in areas subject to intensive professional vector control efforts. Chagas disease control programs traditionally have been composed of two divorced entities: a vector control program in charge of routine field operations (bug detection and insecticide spraying) and a disease control program in charge of screening blood donors, diagnosis, etiologic treatment and providing medical care to chronic patients. The challenge of sustainable suppression of bug infestation and Trypanosoma cruzi transmission can be met through integrated disease management, in which vector control is combined with active case detection and treatment to increase impact, cost-effectiveness and public acceptance in resource-limited settings. Multi-stakeholder involvement may add sustainability and resilience to the surveillance system. Chagas vector control and disease management must remain a regional effort within the frame of sustainable development rather than being viewed exclusively as a matter of health pertinent to the health sector. Sustained and continuous coordination between governments, agencies, control programs, academia and the affected communities is critical. PMID:19753458

Dramatic Decrease in Prevalence of Soil-Transmitted Helminths and New Insights Into Intestinal Protozoa in Children Living in the Chaco Region, Bolivia

PubMed Central

Macchioni, Fabio; Segundo, Higinio; Gabrielli, Simona; Totino, Valentina; Gonzales, Patricia Rojas; Salazar, Esteban; Bozo, Ricardo; Bartoloni, Alessandro; Cancrini, Gabriella

2015-01-01

We assessed the prevalence of intestinal parasites among 268 2–12-year-old children living in rural areas, small villages, and semi-urban areas of the Chaco region, south-eastern Bolivia. The overall parasitism was 69%. Only protozoa, helminths, or co-infections were observed in 89.2%, 5.9%, or 4.9% of the positive children, respectively. A significant progressive increase in overall parasite prevalence was found when passing from rural areas to small villages and semi-urban areas. The most commonly found species were Entamoeba coli (38.4%), Giardia intestinalis (37.7%), and Blastocystis spp. (16%). Hymenolepis nana was the most prevalent helminth (5.6%), followed by Ascaris lumbricoides and hookworms (1.5% and 0.4%) evidenced only in rural areas and in villages. Molecular diagnostics identified Blastocystis subtypes 9 and 2, and 5 infections by Entamoeba histolytica and 4 by Entamoeba dispar. The dramatic decrease in prevalence of soil-transmitted helminths with respect to that observed about 20 years ago (> 40%) evidences the success of the preventive chemotherapy intervention implemented in 1986. Health education and improved sanitation should be intensified to control protozoan infections. PMID:25711609

Discrete typing units of Trypanosoma cruzi identified in rural dogs and cats in the humid Argentinean Chaco

PubMed Central

ENRIQUEZ, G.F.; CARDINAL, M.V.; OROZCO, M.M.; LANATI, L.; SCHIJMAN, A.G.; GÜRTLER, R.E.

2013-01-01

SUMMARY The discrete typing units (DTUs) of Trypanosoma cruzi that infect domestic dogs and cats have rarely been studied. With this purpose we conducted a cross-sectional xenodiagnostic survey of dog and cat populations residing in two infested rural villages in Pampa del Indio, in the humid Argentine Chaco. Parasites were isolated by culture from 44 dogs and 12 cats with a positive xenodiagnosis. DTUs were identified from parasite culture samples using a strategy based on multiple polymerase-chain reactions. TcVI was identified in 37 of 44 dogs and in 10 of 12 cats, whereas TcV was identified in five dogs and in two cats –a new finding for cats. No mixed infections were detected. The occurrence of two dogs infected with TcIII –classically found in armadillos– suggests a probable link with the local sylvatic transmission cycle involving Dasypus novemcinctus armadillos and a potential risk of human infection with TcIII. Our study reinforces the importance of dogs and cats as domestic reservoir hosts and sources of various DTUs infecting humans, and suggests a link between dogs and the sylvatic transmission cycle of TcIII. PMID:23058180

Participatory, Multi-Criteria Evaluation Methods as a Means to Increase the Legitimacy and Sustainability of Land Use Planning Processes. The Case of the Chaco Region in Salta, Argentina.

PubMed

Seghezzo, Lucas; Venencia, Cristian; Buliubasich, E Catalina; Iribarnegaray, Martín A; Volante, José N

2017-02-01

Conflicts over land use and ownership are common in South America and generate frequent confrontations among indigenous peoples, small-scale farmers, and large-scale agricultural producers. We argue in this paper that an accurate identification of these conflicts, together with a participatory evaluation of their importance, will increase the social legitimacy of land use planning processes, rendering decision-making more sustainable in the long term. We describe here a participatory, multi-criteria conflict assessment model developed to identify, locate, and categorize land tenure and use conflicts. The model was applied to the case of the "Chaco" region of the province of Salta, in northwestern Argentina. Basic geographic, cadastral, and social information needed to apply the model was made spatially explicit on a Geographic Information System. Results illustrate the contrasting perceptions of different stakeholders (government officials, social and environmental non-governmental organizations, large-scale agricultural producers, and scholars) on the intensity of land use conflicts in the study area. These results can help better understand and address land tenure conflicts in areas with different cultures and conflicting social and enviornmental interests.

Participatory, Multi-Criteria Evaluation Methods as a Means to Increase the Legitimacy and Sustainability of Land Use Planning Processes. The Case of the Chaco Region in Salta, Argentina

NASA Astrophysics Data System (ADS)

Seghezzo, Lucas; Venencia, Cristian; Buliubasich, E. Catalina; Iribarnegaray, Martín A.; Volante, José N.

2017-02-01

Conflicts over land use and ownership are common in South America and generate frequent confrontations among indigenous peoples, small-scale farmers, and large-scale agricultural producers. We argue in this paper that an accurate identification of these conflicts, together with a participatory evaluation of their importance, will increase the social legitimacy of land use planning processes, rendering decision-making more sustainable in the long term. We describe here a participatory, multi-criteria conflict assessment model developed to identify, locate, and categorize land tenure and use conflicts. The model was applied to the case of the "Chaco" region of the province of Salta, in northwestern Argentina. Basic geographic, cadastral, and social information needed to apply the model was made spatially explicit on a Geographic Information System. Results illustrate the contrasting perceptions of different stakeholders (government officials, social and environmental non-governmental organizations, large-scale agricultural producers, and scholars) on the intensity of land use conflicts in the study area. These results can help better understand and address land tenure conflicts in areas with different cultures and conflicting social and enviornmental interests.

Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest, Part 1: The Southern Colorado Plateau and Rio Grande Regions

USGS Publications Warehouse

Benson, L.V.

2011-01-01

Maize is the New World's preeminent grain crop and it provided the economic basis for human culture in many regions within the Americas. To flourish, maize needs water, sunlight (heat), and nutrients (e. g., nitrogen). In this paper, climate and soil chemistry data are used to evaluate the potential for dryland (rainon-field) agriculture in the semiarid southeastern Colorado Plateau and Rio Grande regions. Processes that impact maize agriculture such as nitrogen mineralization, infiltration of precipitation, bare soil evaporation, and transpiration are discussed and evaluated. Most of the study area, excepting high-elevation regions, receives sufficient solar radiation to grow maize. The salinities of subsurface soils in the central San Juan Basin are very high and their nitrogen concentrations are very low. In addition, soils of the central San Juan Basin are characterized by pH values that exceed 8.0, which limit the availability of both nitrogen and phosphorous. In general, the San Juan Basin, including Chaco Canyon, is the least promising part of the study area in terms of dryland farming. Calculations of field life, using values of organic nitrogen for the upper 50 cm of soil in the study area, indicate that most of the study area could not support a 10-bushel/acre crop of maize. The concepts, methods, and calculations used to quantify maize productivity in this study are applicable to maize cultivation in other environmental settings across the Americas. ?? 2010 US Government.

Ñuagapua (Chaco, Bolivia): Evidence for the latest occurrence of megafauna in association with human remains in South America

NASA Astrophysics Data System (ADS)

Coltorti, Mauro; Della Fazia, Jacopo; Paredes Rios, Freddy; Tito, Giuseppe

2012-02-01

Quebrada (stream) Ñuagapua, which is located in the Bolivian Chaco in the Andean foothill generates an alluvial fan many kilometres in length. Three major lithostratigraphic units characterise the sedimentary sequence in this region. The lower and upper parts are formed from predominantly sandy sediments that demonstrate rapid growth of the alluvial fan, associated with an intense erosion of barren slopes. The intermediate unit consists of forest soil that seals deep channels containing bones together with a forest association. The remains of a wooden plank, dated 140 yr BP, were found at the top of this soil, which laterally contains charcoals, ash layers and large charred trunks, sometimes in growth positions. Roots localised in this layer also sustain a number of very large still living trees. These findings are evidence of a recent phase of alluvial fan sedimentation resulting from slope erosion activated by forest clearing. The Chaco has been intensively settled for agricultural and pastoral purposes since the 18th century. The lower unit contains a hearth, scattered burnt bones, flint flakes and ceramic artefacts. Radiometric dating indicates a middle Holocene human occupation, between ca. 7.79 and 6.65 ka cal yr BP. We suggest that the sedimentary unit is associated with intense soil erosion processes triggered by early Neolithic deforestation. A sandy layer of the lower unit, slightly above the archaeological remains, contains transported bones of megafaunal elements that apparently represent the South American latest occurrence of some extinct taxa. The mammal association is highly heterogeneous, containing species living in aquatic, forest, prairie and savannah environments from a very specific layer that represents the almost simultaneous burial of animals killed slightly up-valley. This anomalous association is probably the result of human impact as opening the forest favoured the introduction of open environment fauna that had previously survived on the southernmost part of the continent. Therefore, humans may have played a role in mammalian extinctions in this region, either directly, due to hunting, or due to changing the paleoenvironmental conditions on a wider scale.

Over Six Thousand Trypanosoma cruzi Strains Classified into Discrete Typing Units (DTUs): Attempt at an Inventory

PubMed Central

Brenière, Simone Frédérique; Waleckx, Etienne; Barnabé, Christian

2016-01-01

Trypanosoma cruzi, the causative agent of Chagas disease, presents wide genetic diversity. Currently, six discrete typing units (DTUs), named TcI to TcVI, and a seventh one called TcBat are used for strain typing. Beyond the debate concerning this classification, this systematic review has attempted to provide an inventory by compiling the results of 137 articles that have used it. A total of 6,343 DTU identifications were analyzed according to the geographical and host origins. Ninety-one percent of the data available is linked to South America. This sample, although not free of potential bias, nevertheless provides today’s picture of T. cruzi genetic diversity that is closest to reality. DTUs were genotyped from 158 species, including 42 vector species. Remarkably, TcI predominated in the overall sample (around 60%), in both sylvatic and domestic cycles. This DTU known to present a high genetic diversity, is very widely distributed geographically, compatible with a long-term evolution. The marsupial is thought to be its most ancestral host and the Gran Chaco region the place of its putative origin. TcII was rarely sampled (9.6%), absent, or extremely rare in North and Central America, and more frequently identified in domestic cycles than in sylvatic cycles. It has a low genetic diversity and has probably found refuge in some mammal species. It is thought to originate in the south-Amazon area. TcIII and TcIV were also rarely sampled. They showed substantial genetic diversity and are thought to be composed of possible polyphyletic subgroups. Even if they are mostly associated with sylvatic transmission cycles, a total of 150 human infections with these DTUs have been reported. TcV and TcVI are clearly associated with domestic transmission cycles. Less than 10% of these DTUs were identified together in sylvatic hosts. They are thought to originate in the Gran Chaco region, where they are predominant and where putative parents exist (TcII and TcIII). Trends in host-DTU specificities exist, but generally it seems that the complexity of the cycles and the participation of numerous vectors and mammal hosts in a shared area, maintains DTU diversity. PMID:27571035

Diversification and biogeography of the Neotropical caviomorph lineage Octodontoidea (Rodentia: Hystricognathi).

PubMed

Upham, Nathan S; Patterson, Bruce D

2012-05-01

The rodent superfamily Octodontoidea comprises 6 families, 38 genera, and 193 living species of spiny rats, tuco-tucos, degus, hutias, and their relatives. All are endemic to the Neotropical Region where they represent roughly three-quarters of extant caviomorphs. Although caviomorph monophyly is well established and phylogenetic hypotheses exist for several families, understanding of octodontoid relationships is clouded by sparse taxon sampling and single-gene analyses. We examined sequence variation in one mitochondrial (12S rRNA) and three nuclear genes (vWF, GHR, and RAG1) across all caviomorph families (including 47 octodontoid species), all phiomorph families, and the sole remaining hystricognath family, using the gundi (Ctenodactylus) and springhaas (Pedetes) as outgroups. Our analyses support the monophyly of Phiomorpha, Caviomorpha, and the caviomorph superfamilies Cavioidea (Dasyproctidae, Cuniculidae, and Caviidae, the latter including Hydrochoerus), Erethizontoidea, Chinchilloidea (including Dinomyidae), and Octodontoidea. Cavioids and erethizontoids are strongly supported as sisters, whereas chinchilloids appear to be sister to octodontoids. Among octodontoids, Abrocomidae is consistently recovered as the basal element, sister to a pair of strongly supported clades; one includes Octodontidae and Ctenomyidae as reciprocally monophyletic lineages, whereas the other includes taxa currently allocated to Echimyidae, Capromyidae and Myocastoridae. Capromys appears near the base of this clade, in keeping with current classification, but Myocastor is nested securely inside a clade of Echimyidae that also contains eumysopines, echimyines and dactylomyines. Another, more weakly supported clade of Echimyidae contains fossorial and scansorial taxa from the Chaco-Cerrado-Caatinga and the Atlantic Forest. Biogeographic analyses robustly recover the Patagonia-Southern Andes complex as ancestral for the Octodontoidea, with three component lineages emerging by the Oligocene-Miocene boundary (∼23Ma): (1) stem abrocomids in the Central and Southern Andes; (2) a lineage leading to octodontids plus ctenomyids in Patagonia, later dispersing into the Chaco-Cerrado-Caatinga; and (3) a lineage leading to echimyids, capromyids, and myocastorids that subsequently radiated in more mesic biomes, including Amazonia, Atlantic Forest, and the Antilles. This reconstruction refutes earlier ideas that the diverse, generalized, mainly lowland family Echimyidae, which appears early in the fossil record, gave rise to the Andean lineages of octodontoids-instead, the reverse derivation appears to be true. We recommend formal synonymy of Myocastoridae with Echimyidae but defer a similar treatment of Capromyidae until additional hutia taxa and sequences can be analyzed. Copyright © 2012 Elsevier Inc. All rights reserved.

Enhanced Preliminary Assessment Report: Fort Wingate Depot Activity Gallup, New Mexico

DTIC Science & Technology

1990-03-01

Census, 1980 Census of Population. U 20 uranium exploration, mining, and milling, while the trade sector is influenced by the Zuni and Navajo ...Five Indian reservations, eight national park areas ( Navajo , Chaco Canyon, Aztec Ruins, El Moro National Monuments, Mesa Verde, and Petrified Forest...Argonne National Laboratory Argonne, Illinois 60439 IAppmvd bo o. 90 0611 090 CETHA-BC-CR-90051 Enhanced Preliminary Assessment Report: Fort Wingate Depot

Effects of Low Flying Aircraft on Archaeological Structures

DTIC Science & Technology

1988-09-26

obtained from direct observation of aircraft overflights at one particular site, Ixng House, near Kayenta . Arizona. 2. THE SITE The Long House site is...located approximately 20 km southwest of Kayenta , Arizona, as shown in Figure 1. The Long House ruins were part of an extensive Anasazi agricultural...community that was (Received for Publication 22 September 1988) 1 UTAH COLORADO ARIZONANEW MEXICO LONG HOUSE I FARMINGTON SITE KAYENTA I CHACO CANYON

Argentinian phlebotomine fauna, new records of Phlebotominae (Diptera: Psychodidae) for the country and the province of Chaco.

PubMed

Szelag, Enrique A; Filho, Jose D Andrade; Rosa, Juan R; Parras, Matias A; Quintana, Maria G; Quintana, Maria G; Salomon, Oscar D

2016-07-21

Sand flies are insects of medical and veterinary importance, because some species are able to transmit several pathogens such as Bartonella spp., Phlebovirus spp., and protozoan parasites of the genus Leishmania (Ross). They are widely distributed in the Americas, with recordings ranging from Canada to Argentina. Approximately 500 Phlebotominae species are known in the Americas, of which it is considered that at least 56 are involved in the transmission of leishmaniasis (Maroli et al. 2012). Previous studies have shown that the phlebotomine fauna in Argentina consists of 32 species distributed in 14 provinces (Quintana et al. 2012; Sábio et al. 2015; Salomón et al. 2010). Of these species, Lutzomyia longipalpis (Lutz & Neiva), Nyssomyia neivai (Pinto), Ny. whitmani (Antunes & Countinho), Cortelezzii complex [Evandromyia cortelezzii (Brèthes) - Ev. sallesi (Galvão & Coutinho)], Micropygomyia quinquefer (Dyar) and Migonemyia migonei (França) have been found with DNA of Leishmania spp. (Moya et al. 2015). Five new records of species in the province of Chaco, obtained from different projects carried out between 2001 and 2015, four of which are also new records for Argentina, are described in this article. Their importance as potential vectors and the correct determination of the sympatric species is also discussed.

Intestinal parasitic infections and associated epidemiological drivers in two rural communities of the Bolivian Chaco.

PubMed

Macchioni, Fabio; Segundo, Higinio; Totino, Valentina; Gabrielli, Simona; Rojas, Patricia; Roselli, Mimmo; Paredes, Grover Adolfo; Masana, Mario; Bartoloni, Alessandro; Cancrini, Gabriella

2016-09-30

In 2013 a coproparasitological survey was carried out in two rural communities of the Bolivian Chaco to determine the prevalence of intestinal parasitic infections (IPIs) and to investigate on possible infection drivers through a questionnaire interview. Faecal samples were examined by microscopy. Samples positive for Entamoeba histolytica complex and Blastocystis were molecularly examined to identify the species/subtypes involved. The overall infection rate was 86%, identical in both communities and mostly due to protozoa. Soil-transmitted helminths were detected in <3% of children and adults. The protozoa detected, including Blastocystis subtypes, indicate faecal contamination of the environment by both humans (as confirmed by the presence of Hymenolepis nana) and animals. Nested-PCR identified E. histolytica, thus signalling the possible occurrence of invasive amoebosis. Lack of safe water, environmental contamination, poor sanitation and hygiene, shared by both communities, are the main drivers of IPIs. In addition, unlike gender and socioeconomic factors, childhood (only for some species), crowding and cohabitation with animals proved to be further significant protozoon infection risk factors. These results highlight the need for the promotion of access to clean water, improved sanitation and better hygiene, thus reducing the frequency of preventive chemotherapy for STHs while continuing to monitor the population for possible recrudescence.

Indigenous Starter Cultures to Improve Quality of Artisanal Dry Fermented Sausages from Chaco (Argentina).

PubMed

Palavecino Prpich, Noelia Z; Castro, Marcela P; Cayré, María E; Garro, Oscar A; Vignolo, Graciela M

2015-01-01

Lactic acid bacteria (LAB) and coagulase negative cocci (CNC) were isolated from artisanal dry sausages sampled from the northeastern region of Chaco, Argentina. In order to evaluate their performance in situ and considering technological features of the isolated strains, two mixed selected autochthonous starter cultures (SAS) were designed: (i) SAS-1 (Lactobacillus sakei 487 + Staphylococcus vitulinus C2) and (ii) SAS-2 (L. sakei 442 + S. xylosus C8). Cultures were introduced into dry sausage manufacturing process at a local small-scale facility. Microbiological and physicochemical parameters were monitored throughout fermentation and ripening periods, while sensory attributes of the final products were evaluated by a trained panel. Lactic acid bacteria revealed their ability to colonize and adapt properly to the meat matrix, inhibiting the growth of spontaneous microflora and enhancing safety and hygienic profile of the products. Both SAS showed a beneficial effect on lipid oxidation and texture of the final products. Staphylococcus vitulinus C2, from SAS-1, promoted a better redness of the final product. Sensory profile revealed that SAS addition preserved typical sensory attributes. Introduction of these cultures could provide an additional tool to standardize manufacturing processes aiming to enhance safety and quality while keeping typical sensory attributes of regional dry fermented sausages.

Land-use policies and corporate investments in agriculture in the Gran Chaco and Chiquitano

PubMed Central

le Polain de Waroux, Yann; Garrett, Rachael D.; Heilmayr, Robert; Lambin, Eric F.

2016-01-01

Growing demand for agricultural commodities is causing the expansion of agricultural frontiers onto native vegetation worldwide. Agribusiness companies linking these frontiers to distant spaces of consumption through global commodity chains increasingly make zero-deforestation pledges. However, production and land conversion are often carried out by less-visible local and regional actors that are mobile and responsive to new agricultural expansion opportunities and legal constraints on land use. With more stringent deforestation regulations in some countries, we ask whether their movements are determined partly by differences in land-use policies, resulting in “deforestation havens.” We analyze the determinants of investment decisions by agricultural companies in the Gran Chaco and Chiquitano, a region that has become the new deforestation “hot spot” in South America. We test whether companies seek out less-regulated forest areas for new agricultural investments. Based on interviews with 82 companies totaling 2.5 Mha of properties, we show that, in addition to proximity to current investments and the availability of cheap forestland, lower deforestation regulations attract investments by companies that tend to clear more forest, mostly cattle ranching operations, and that lower enforcement attracts all companies. Avoiding deforestation leakage requires harmonizing deforestation regulations across regions and commodities and promoting sustainable intensification in cattle ranching. PMID:27035995

Land-use policies and corporate investments in agriculture in the Gran Chaco and Chiquitano.

PubMed

le Polain de Waroux, Yann; Garrett, Rachael D; Heilmayr, Robert; Lambin, Eric F

2016-04-12

Growing demand for agricultural commodities is causing the expansion of agricultural frontiers onto native vegetation worldwide. Agribusiness companies linking these frontiers to distant spaces of consumption through global commodity chains increasingly make zero-deforestation pledges. However, production and land conversion are often carried out by less-visible local and regional actors that are mobile and responsive to new agricultural expansion opportunities and legal constraints on land use. With more stringent deforestation regulations in some countries, we ask whether their movements are determined partly by differences in land-use policies, resulting in "deforestation havens." We analyze the determinants of investment decisions by agricultural companies in the Gran Chaco and Chiquitano, a region that has become the new deforestation "hot spot" in South America. We test whether companies seek out less-regulated forest areas for new agricultural investments. Based on interviews with 82 companies totaling 2.5 Mha of properties, we show that, in addition to proximity to current investments and the availability of cheap forestland, lower deforestation regulations attract investments by companies that tend to clear more forest, mostly cattle ranching operations, and that lower enforcement attracts all companies. Avoiding deforestation leakage requires harmonizing deforestation regulations across regions and commodities and promoting sustainable intensification in cattle ranching.

Experimental control of Triatoma infestans in poor rural villages of Bolivia through community participation

PubMed Central

Lardeux, Frédéric; Depickère, Stéphanie; Aliaga, Claudia; Chavez, Tamara; Zambrana, Lilian

2015-01-01

Background Triatoma infestans is the main vector of Chagas disease in the southern cone countries. Present control strategies based on indoor and outdoor residual insecticide spraying are not sufficient to control disease transmission, particularly in Bolivia. Techniques based on the management of the human environment may be good alternatives or supplements. Methods Social and entomological surveys were carried out in four villages of Bolivia situated in the dry inter-Andean Valleys and the Chaco region. Risk factors for house infestation by T. infestans were identified, and an eco-health intervention based on education and community participation was carried out to reduce the risks of house infestation. It consisted of implementing simple and low cost vector control techniques such as coating of mud walls, cleaning activities and removal of poultry that enter rooms to lay eggs. Results The eco-health intervention significantly reduced the number of infested bedrooms, the mean abundance of T. infestans in bedrooms and beds, especially in the Chaco region. Mud wall coating was well accepted and could be proposed as a supplementary tool to the National Program of Chagas Disease Control to enhance the effects of insecticide sprayings. Conclusions Even if cleaning activities were still neglected, community participation proved to be effective in reducing house infestation. PMID:25604766

Active dispersal of Triatoma infestans and other triatomines in the Argentinean arid Chaco before and after vector control interventions.

PubMed

Abrahan, Luciana; Gorla, David; Catalá, Silvia

2016-06-01

Peridomestic structures are considered the main sites where Triatoma infestans (Hemiptera: Reduviidae) remain and disperse, representing the first risk factor for intradomestic invasion, even after vector control activities. This study analyzed T. infestans dispersal during vector control interventions in six rural houses of the arid Chaco (La Rioja, Argentina). Flying and walking dispersers were captured during five months of two consecutive warm seasons after insecticide spraying of intra- and peridomiciles. These data were compared with previous published data in the same scenario but without insecticide spraying in peridomiciles. Recorded climatic conditions were favorable for active dispersion during the study. Total number of T. infestans dispersers moving among domestic habitats decreased after insecticide spraying. Sylvatic triatomines T. guasayana, T. eratyrusiformis, T. garciabesi, and T. platensis, not targeted by insecticide spraying, were captured simultaneously within peridomestic areas and showed higher invasion pressure than T. infestans. Adult T. infestans peridomestic populations showed high nutritional status, indicating low dispersion probability. Some peridomiciles remained infested at the end of the study. However, no intradomiciles were recolonized. These results suggest that there is a low probability of intradomestic recolonization by active dispersion from peridomiciles during 15 months post-spraying. © 2016 The Society for Vector Ecology.

Dramatic decrease in prevalence of soil-transmitted helminths and new insights into intestinal protozoa in children living in the Chaco region, Bolivia.

PubMed

Macchioni, Fabio; Segundo, Higinio; Gabrielli, Simona; Totino, Valentina; Gonzales, Patricia Rojas; Salazar, Esteban; Bozo, Ricardo; Bartoloni, Alessandro; Cancrini, Gabriella

2015-04-01

We assessed the prevalence of intestinal parasites among 268 2-12-year-old children living in rural areas, small villages, and semi-urban areas of the Chaco region, south-eastern Bolivia. The overall parasitism was 69%. Only protozoa, helminths, or co-infections were observed in 89.2%, 5.9%, or 4.9% of the positive children, respectively. A significant progressive increase in overall parasite prevalence was found when passing from rural areas to small villages and semi-urban areas. The most commonly found species were Entamoeba coli (38.4%), Giardia intestinalis (37.7%), and Blastocystis spp. (16%). Hymenolepis nana was the most prevalent helminth (5.6%), followed by Ascaris lumbricoides and hookworms (1.5% and 0.4%) evidenced only in rural areas and in villages. Molecular diagnostics identified Blastocystis subtypes 9 and 2, and 5 infections by Entamoeba histolytica and 4 by Entamoeba dispar. The dramatic decrease in prevalence of soil-transmitted helminths with respect to that observed about 20 years ago (> 40%) evidences the success of the preventive chemotherapy intervention implemented in 1986. Health education and improved sanitation should be intensified to control protozoan infections. © The American Society of Tropical Medicine and Hygiene.

Brief communication: unusual finding at Pueblo Bonito: multiple cases of hyperostosis frontalis interna.

PubMed

Mulhern, Dawn M; Wilczak, Cynthia A; Dudar, J Christopher

2006-08-01

Hyperostosis frontalis interna (HFI) is a disease characterized by excess bone growth on the internal lamina of the frontal bone and, occasionally, other cranial bones. Although the disease is fairly common in modern populations, its etiology is poorly understood. Hyperostosis frontalis interna has been identified in antiquity, primarily in the Old World, but with a much lower frequency than in modern groups. The purpose of the present study is to report multiple cases of HFI at Pueblo Bonito (Chaco Canyon, New Mexico). Twelve out of 37 adults with observable frontal bones exhibited HFI, ranging from mild to severe, including 11 females and one male. This is the first published case report of HFI in archaeological remains from the New World having a frequency comparable with modern groups. Most archaeological cases of HFI are isolated, so comparative data for multiple cases at one site are rare. The results of this study emphasize the importance of looking for HFI in archaeological remains, although it is rarely observed. Possible genetic and environmental factors for the high frequency of HFI at Chaco Canyon are considered, but additional research is needed to discover the etiology and to better understand why HFI sometimes occurs at modern frequencies in ancient populations.

Large U.S. liquids plant starts up

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milios, P.B.; Harris, R.A.

1997-05-12

Operation began in 1996 on the new Chaco liquids-extraction plant in northwest New Mexico. The plant`s extraction capacity--50,000 b/d of NGLs from 600 MMcfd of gas--exceeds that of any other turboexpander plant in the lower 48 states. Regulatory reform made the project possible, and significant regulatory, economic, environmental, technical, and logistic challenges were overcome to achieve plant start-up. Operator El Paso Field Services, Houston, believes the new Chaco plant creates added value when compared to the lean-oil extraction plant which El Paso had operated at the San Juan basin site since the 1950s. Success of the project was based, inmore » part, on the following: creation of a free-market company by the spin-down of El Paso Field Services (EPFS) from El Paso Natural Gas (EPNG); establishment of agreements with producers behind the plant to share the benefits generated by the plant in exchange for acreage dedication; negotiation of an agreement with Mid-America Pipeline Co. to expand its pipeline system to receive and deliver to market liquids from the new plant; and selection of ABB Randall which committed to engineer, procure for, and construct the plant at a cost which provided an adequate rate of return. These four issues are discussed. Construction and start-up are described.« less

Environment or beekeeping management: What explains better the prevalence of honey bee colonies with high levels of Varroa destructor?

PubMed

Giacobino, Agostina; Pacini, Adriana; Molineri, Ana; Bulacio Cagnolo, N; Merke, J; Orellano, E; Bertozzi, E; Masciangelo, G; Pietronave, H; Signorini, M

2017-06-01

Varroa destructor is one of the major threats to honey bee colonies. The mite abundance in the colonies is affected by environmental conditions as well as by beekeeping management. The aim of this study was to recognize the main drivers associated with autumn V. destructor infestation in honey bee colonies when different regions from Argentina are compared. A total of 361 colonies distributed in five Argentinean eco-regions were examined to evaluate Varroa mite infestation rate during autumn and Nosema sp. presence. Regions were different regarding annual temperature, precipitation and especially vegetation landscape. In addition, beekeeping management practices were obtained from a checklist questionnaire answered by the beekeepers. The prevalence of colonies with high infestation level was lower in semi-arid Chaco followed by humid and transition Chaco regions. Also, colonies that were positive for Nosema sp. showed a higher Varroa infestation rate. The "environmental" effect was stronger compared with the influence of secondary drivers associated with beekeeping activities. As well, a significant association between V. destructor infestation rates and Nosema presence was identified. Under contrasting natural conditions, environment seems a predominant driver on Varroa destructor infestation level in honey bee colonies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sources and controls for the mobility of arsenic in oxidizing groundwaters from loess-type sediments in arid/semi-arid dry climates - evidence from the Chaco-Pampean plain (Argentina).

PubMed

Nicolli, Hugo B; Bundschuh, Jochen; García, Jorge W; Falcón, Carlos M; Jean, Jiin-Shuh

2010-11-01

In oxidizing aquifers, arsenic (As) mobilization from sediments into groundwater is controlled by pH-dependent As desorption from and dissolution of mineral phases. If climate is dry, then the process of evaporative concentration contributes further to the total concentration of dissolved As. In this paper the principal As mobility controls under these conditions have been demonstrated for Salí River alluvial basin in NW Argentina (Tucumán Province; 7000 km(2)), which is representative for other basins or areas of the predominantly semi-arid Chaco-Pampean plain (1,000,000 km(2)) which is one of the world's largest regions affected by high As concentrations in groundwater. Detailed hydrogeochemical studies have been performed in the Salí River basin where 85 groundwater samples from shallow aquifers (42 samples), deep samples (26 samples) and artesian aquifers (17 samples) have been collected. Arsenic concentrations range from 11.4 to 1660 μg L(-1) leaving 100% of the investigated waters above the provisional WHO guideline value of 10 μg L(-1). A strong positive correlation among As, F, and V in shallow groundwaters was found. The correlations among those trace elements and U, B and Mo have less significance. High pH (up to 9.2) and high bicarbonate (HCO(3)) concentrations favour leaching from pyroclastic materials, including volcanic glass which is present to 20-25% in the loess-type aquifer sediments and yield higher trace element concentrations in groundwater from shallow aquifers compared to deep and artesian aquifers. The significant increase in minor and trace element concentrations and salinity in shallow aquifers is related to strong evaporation under semi-arid climatic conditions. Sorption of As and associated minor and trace elements (F, U, B, Mo and V) onto the surface of Fe-, Al- and Mn-oxides and oxi-hydroxides, restricts the mobilization of these elements into groundwater. Nevertheless, this does not hold in the case of the shallow unconfined groundwaters with high pH and high concentrations of potential competitors for adsorption sites (HCO(3), V, P, etc.). Under these geochemical conditions, desorption of the above mentioned anions and oxyanions occurs as a key process for As mobilization, resulting in an increase of minor and trace element concentrations. These geochemical processes that control the concentrations of dissolved As and other trace elements and which determine the groundwater quality especially in the shallow aquifers, are comparable to other areas with high As concentrations in groundwater of oxidizing aquifers and semi-arid or arid climate, which are found in many parts of the world, such as the western sectors of the USA, Mexico, northern Chile, Turkey, Mongolia, central and northern China, and central and northwestern Argentina. Copyright © 2010 Elsevier Ltd. All rights reserved.

Variables en la región central del cúmulo globular NGC 3201: descomposición de Fourier de las curvas de luz de las RR Lyrae y análisis de la relación período-luminosidad de las SX Phoenicis

NASA Astrophysics Data System (ADS)

Ahumada, J. A.; Arellano Ferro, A.; Calderón, J. H.; Kains, N.

2015-08-01

We present CCD time-series observations of the central region of the globular cluster NGC 3201, collected from CASLEO in March 2013, with the aim of performing the Fourier decomposition of the light curves of the RR Lyrae variables. This procedure, applied to the RRab-type stars, gave a mean value [Fe/H], for the cluster metallicity, and 5.00 0.22 kpc, for the cluster distance. The values found from two RRc stars are consistent with those derived previously. Because of differential reddening across the cluster field, individual reddenings for the RRab stars were estimated from their curves, resulting in an average value . An investigation of the light curves of stars in the blue straggler region led to the discovery of three new SX Phoenicis variables. The period-luminosity relation of the SX Phoenicis was used for an independent determination of the distance to the cluster and of the individual reddenings of these variables.

The Las Matras tonalitic trondhjemitic pluton, central Argentina: Grenvillian-age constraints, geochemical characteristics, and regional implications

NASA Astrophysics Data System (ADS)

Sato, A. M.; Tickyj, H.; Llambías, E. J.; Sato, K.

2000-12-01

The N-S trending belt with Grenvillian-age rocks developed in central western Argentina represents the basement of an allochthonous terrane derived from Laurentia during the Early Paleozoic. The Las Matras pluton (36°46‧S, 67°07‧W) is located at the southern extension of this belt in the Las Matras Block. It consists of a low-Al tonalitic to trondhjemitic facies characteristic of an arc magmatism. Isotopic studies yielded Grenvillian Rb-Sr (1212±47 Ma) and Sm-Nd (1188±47 Ma) ages which, due to the undeformed and non-metamorphosed character of the pluton, are interpreted to represent a crystallization age of around 1200 Ma. Although this age is slightly older than available dates from other exposures of the same belt, and the undeformed feature is also distinctive for Las Matras, the depleted Sr and Nd isotopic signatures of the pluton agree with those from other magmatic rocks involved in that belt. The differences found between Las Matras and the northern exposures indicate that this belt with Grenvillian-age rocks comprises regions of non-homogeneous evolution. Although the correlation of the Lower Paleozoic platform carbonates from the sedimentary cover of the Grenvillian-age basement rocks suggests the surroundings of the Southern Grenville Province (Texas and northern Mexico) as the probable detachment site for the Argentine belt, comparison of magmatic and tectonic processes involved in these basement rocks does not indicate similar evolutions. This fact can suggest an independent evolution of the Argentine belt prior to amalgamation to the Laurentian Grenville orogen.

Power Pack: U.S. Intervention in the Dominican Republic, 1965-1966 (Leavenworth Papers, Number 15)

DTIC Science & Technology

1988-07-01

Center (Centro de Entrenamiento de las Fuerzas 22 Elias Wessin y Wessin Armadas, or CEFA), an elite group of nearly 2,000 specially trained infan- try...battalion combat team battalion landing team Centro de Entrenamiento de las Fuerzas Armadas (Armed Forces Training Cen- ter) Central Intelligence...operations. As with Lebanon in 1958, the Domin- ican intervention was a joint operation. In general terms, many of the de - ficiencies revealed in joint

Axonal Regeneration in Mammals with Spinal Cord Injury

DTIC Science & Technology

1983-09-14

Cajal, S. 1905. Notas preventivas sobre la degeneracion y regeneracion las vias nerviosos centrales . Trab. Lab. Invest. Biol. Univ. Madrid, 4: 295-301...S. 1914. Degeneracion y Regeneration del Sistema Nervioso , Vol. 1, 2. (Nicolas Moya, Madrid), Ramon y Cajal, S. 1928. Degeneration and Regeneration...field of central nervous system (CNS) regeneration research. These developments have revealed important aspects regarding the histology and

40 CFR Table C-5 to Subpart C of... - Summary of Comparability Field Testing Campaign Site and Seasonal Requirements for Class II and...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Angeles basin or California Central Valley Western city such as Denver, Salt Lake City, or Albuquerque Midwestern city Northeastern or mid-Atlantic city. Test site characteristics Relatively high PM2.5, nitrates... area Los Angeles basin or California Central Valley Western city such as Las Vegas or Phoenix...

The evolutionary history of Lygodactylus lizards in the South American open diagonal.

PubMed

Lanna, Flávia M; Werneck, Fernanda P; Gehara, Marcelo; Fonseca, Emanuel M; Colli, Guarino R; Sites, Jack W; Rodrigues, Miguel T; Garda, Adrian A

2018-06-12

The Pleistocenic Arc Hypothesis (PAH) posits that South American Seasonally Dry Tropical Forests (SDTF) were interconnected during Pleistocene glacial periods, enabling the expansion of species ranges that were subsequently fragmented in interglacial periods, promoting speciation. The lizard genus Lygodactylus occurs in Africa, Madagascar, and South America. Compared to the high diversity of African Lygodactylus, only two species are known to occur in South America, L. klugei and L. wetzeli, distributed in SDTFs and the Chaco, respectively. We use a phylogenetic approach based on mitochondrial (ND2) and nuclear (RAG-1) markers covering the known range of South American Lygodactylus to investigate (i) if they are monophyletic relative to their African congeners, (ii) if their divergence is congruent with the fragmentation of the PAH, and (iii) if cryptic diversity exists within currently recognized species. Maximum likelihood and Bayesian phylogenetic analyses recovered a well-supported monophyletic South American Lygodactylus, presumably resulting from a single trans-Atlantic dispersal event 29 Mya. Species delimitation analyses supported the existence of five putative species, three of them undescribed. Divergence times among L. klugei and the three putative undescribed species, all endemic to the SDTFs, are not congruent with the fragmentation of the PAH. However, fragmentation of the once broader and continuous SDTFs likely influenced the divergence of L. wetzeli in the Chaco and Lygodactylus sp. 3 (in a SDTF enclave in the Cerrado). Copyright © 2018. Published by Elsevier Inc.

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

PubMed

Carvajal, Guillermo; Picollo, María Inés; Toloza, Ariel Ceferino

2014-09-01

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.

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

PubMed Central

Carvajal, Guillermo; Picollo, María Inés; Toloza, Ariel Ceferino

2014-01-01

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. PMID:25141281

Experimental control of Triatoma infestans in poor rural villages of Bolivia through community participation.

PubMed

Lardeux, Frédéric; Depickère, Stéphanie; Aliaga, Claudia; Chavez, Tamara; Zambrana, Lilian

2015-02-01

Triatoma infestans is the main vector of Chagas disease in the southern cone countries. Present control strategies based on indoor and outdoor residual insecticide spraying are not sufficient to control disease transmission, particularly in Bolivia. Techniques based on the management of the human environment may be good alternatives or supplements. Social and entomological surveys were carried out in four villages of Bolivia situated in the dry inter-Andean Valleys and the Chaco region. Risk factors for house infestation by T. infestans were identified, and an eco-health intervention based on education and community participation was carried out to reduce the risks of house infestation. It consisted of implementing simple and low cost vector control techniques such as coating of mud walls, cleaning activities and removal of poultry that enter rooms to lay eggs. The eco-health intervention significantly reduced the number of infested bedrooms, the mean abundance of T. infestans in bedrooms and beds, especially in the Chaco region. Mud wall coating was well accepted and could be proposed as a supplementary tool to the National Program of Chagas Disease Control to enhance the effects of insecticide sprayings. Even if cleaning activities were still neglected, community participation proved to be effective in reducing house infestation. © The author 2015. The World Health Organization has granted Oxford University Press permission for the reproduction of this article.

Habitat degradation may affect niche segregation patterns in lizards

NASA Astrophysics Data System (ADS)

Pelegrin, N.; Chani, J. M.; Echevarria, A. L.; Bucher, E. H.

2013-08-01

Lizards partition resources in three main niche dimensions: time, space and food. Activity time and microhabitat use are strongly influenced by thermal environment, and may differ between species according to thermal requirements and tolerance. As thermal characteristics are influenced by habitat structure, microhabitat use and activity of lizards can change in disturbed habitats. We compared activity and microhabitat use of two abundant lizard species of the Semi-arid Chaco of Argentina between a restored and a highly degraded Chaco forest, to determine how habitat degradation affects lizard segregation in time and space, hypothesizing that as activity and microhabitat use of lizards are related to habitat structure, activity and microhabitat use of individual species can be altered in degraded habitats, thus changing segregation patterns between them. Activity changed from an overlapped pattern in a restored forest to a segregated pattern in a degraded forest. A similar trend was observed for microhabitat use, although to a less extent. No correlation was found between air temperature and lizard activity, but lizard activity varied along the day and among sites. Contrary to what was believed, activity patterns of neotropical diurnal lizards are not fixed, but affected by multiple factors related to habitat structure and possibly to interspecific interactions. Changes in activity patterns and microhabitat use in degraded forests may have important implications when analyzing the effects of climate change on lizard species, due to synergistic effects.

Genetic diversity of a late prehispanic group of the Quebrada de Humahuaca, northwestern Argentina.

PubMed

Mendisco, Fanny; Keyser, Christine; Seldes, Veronica; Rivolta, Clara; Mercolli, Pablo; Cruz, Pablo; Nielsen, Axel E; Crubezy, Eric; Ludes, Bertrand

2014-09-01

This palaeogenetic study focused on the analysis of a late prehispanic Argentinean group from the Humahuaca valley, with the main aim of reconstructing its (micro)evolutionary history. The Humahuaca valley, a natural passageway from the eastern plains to the highlands, was the living environment of Andean societies whose cultural but especially biological diversity is still poorly understood. We analyzed the DNA extracted from 39 individuals who populated this upper valley during the Regional Development period (RDP) (between the 11th and 15th centuries CE), to determine their maternal and paternal genetic ancestry. Some mitochondrial and Y-chromosomal haplotypes specific to the Andean region are consistent with an origin in the highlands of Central Andes. On the other hand, a significant genetic affinity with contemporary admixed communities of the Chaco area was detected. Expectedly, recent demographic events, such as the expansion of the Inca Empire or the European colonization, have changed the original mitochondrial gene pool of the ancient Humahuaca Valley community. Finally, we identified a particular geographical organization of the prehispanic populations of Northwestern Argentina. Our results suggest that the communities of the region were divided between two different spheres of interaction, which is consistent with assumptions made by means of craniometric traits. © 2014 John Wiley & Sons Ltd/University College London.

[Axonopathy in the pathogenesis of multiple sclerosis, peripheral diffuse and local motor neuropathies and motor neuron disease].

PubMed

Merkulov, Iu A; Merkulova, D M; Iosifova, O A; Zavalishin, I A

2010-01-01

Two hundreds and seventy-six patients including 43 patients with multiple sclerosis, 24 - with acute inflammatory demyelinating polyneuropathy (AIDP), 144 - with chronic inflammatory demyelinating polyneuropathy (CIDP), 27 - with motor multifocal neuropathy (MMN), 38 - with lateral amyotrophic sclerosis (LAS) have been examined. Symptoms of axonal degeneration, manifested in denervation phenomena in both clinical and instrumental studies (electromyography, transcranial magnetic stimulation, MRT), were revealed in all groups of patients. The formation of excitation conduction blocks is an universal pathophysiological mechanism of the axonopathy development in AIDP, CIDP, MMN and LAS. Symptoms of axonopathy and peripheral demyelinization in patients with multiple sclerosis and LAS suggest the possibility of transformation of immunopathological process from the central nervous system to the peripheral one.

Reinterpretation of the stratigraphy and structure of the Rancho Las Norias area, central Sonora, Mexico

USGS Publications Warehouse

Page, W.R.; Harris, A.G.; Poole, F.G.; Repetski, J.E.

2003-01-01

New geologic mapping and fossil data in the vicinity of Rancho Las Norias, 30 km east of Hermosillo, Sonora, Mexico, show that rocks previously mapped as Precambrian instead are Paleozoic. Previous geologic maps of the Rancho Las Norias area show northeast-directed, southwest-dipping reverse or thrust faults deforming both Precambrian and Paleozoic rocks. The revised stratigraphy requires reinterpretation of some of these faults as high-angle normal or oblique-slip faults and the elimination of other faults. We agree with earlier geologic map interpretations that compressional structures have affected the Paleozoic rocks in the area, but our mapping suggests that the direction of compression is from southeast to northwest. Published by Elsevier Ltd.

The ants of North and Central America: the genus Mycocepurus (Hymenoptera: Formicidae)

PubMed Central

Mackay, William P.; Maes, Jean-Michel; Fernández, Patricia Rojas; Luna, Gladys

2004-01-01

Abstract We provide a review of the North American ants (north of Colombia) of the ant genus Mycocepurus, including keys to the workers and females, illustrations and distribution maps. The distribution of M. tardus is extended to Nicaragua and Costa Rica. The female of M. curvispinosus is described. Resumen Se revisan las especies del género Mycocepurus de Norte América (al norte de Colombia). Se incluyen claves para la identificación de las obreras y las hembras, ilustraciones y mapas de distribución. Se amplia hacia el norte la distribución de M. tardus, incluyendo ahora Nicaragua y Costa Rica y se describe la hembra de M. curvispinosus. PMID:15861242

Archaeological Reconnaissance Survey of Pool 10, Upper Mississippi River, Grant and Crawford Counties, Wisconsin, and Allamakee and Clayton Counties, Iowa

DTIC Science & Technology

1984-10-01

buried archaeo- logical components during the Stage I sample provided useful - new information. At the same time , Stage I sample results demonstrated...by erosion directly related to maintenance and operation of the 9 foot navigation channel. At the same time , numerous sites of early to middle...Analysis. Publication No. 3, Chaco Center Studies. National Park Service and University of New Mexico. MALLAM, R. CLARK 1976 The Iowa Effigy Mound

The Coast Artillery Journal. Volume 78, Number 3, May-June 1935

DTIC Science & Technology

1935-06-01

proper. The two belligerents are now approaching what most military observers believe will be the final and de - cisive campaign of the war. Apart from the...all great leaders, he at once began an exhaustive study of the Chaco Boreal. In 1927 he finished a three-year course at the French Ecole Superieure de ... de - livered over the same terrain as the Julv offensive, forced Estigarribia to withdraw troops froni the defenses of Camp Jordan to meet it. Thereupon

Panoramic View of the Andes Mountains, Chile and Argentina

NASA Technical Reports Server (NTRS)

1992-01-01

This panoramic view of the Andes Mountains of Chile and Argentina (24.5S, 69.5W) is dominated by the yellows and browns of the coastal Atacama Desert and the full width of the Andes altiplano, about 300 miles. Winter snow can be seen capping the 22,000 to 23,000 ft. peaks of the Andes. Wisps of cirrus clouds lie over the altiplano and offshore fog obscures the coast. In the distance, the low Chaco Plain appears green with pastures and agriculture.

Distributional patterns of living ungulates (Mammalia: Cetartiodactyla and Perissodactyla) of the Neotropical region, the South American transition zone and Andean region

NASA Astrophysics Data System (ADS)

Absolon, Bruno Araujo; Gallo, Valéria; Avilla, Leonardo S.

2016-11-01

To recognize the distributional patterns of living ungulates in the Neotropical region, the South American transition zone, and Andean region using the panbiogeographical method of track analysis, and to attempt to correlate these patterns with geological history. The distribution of 24 species of living ungulates (in the families Camelidae, Cervidae, Tapiridae and Tayassuidae) was studied by the panbiogeographical method of track analysis. It was performed using distributional data acquired from literature and databases of scientific institutions. Individual tracks were obtained for each species by plotting locality records on maps and connecting them by minimum-spanning trees. Generalized tracks were determined from the spatial overlap between individual tracks, indicating a common history. The intersection between generalized tracks defined a biogeographic node, implying that these locations are biogeographic composites resulting from different ancestral biotas coming into spatial contact, possibly at different geologic times. The superposition of the 24 individual tracks resulted in five generalized tracks (GTs): GT1, Mesoamerican/Choco (composed of Mazama pandora, Mazama temama, Odoicoileus virginianus and Tapirus bairdii); GT2, Northern Andes (Mazama rufina, Pudu mephistophiles and Tapirus pinchaque); GT3, Central Andes (Hippocamelus antisensis, Lama guanicoe, Mazama chunyi and Vicugna vicugna); GT4, Chilean Patagonia (Hippocamelus bisulcus and Pudu puda); and GT5, Chaco/Central west Brazil (Blastocerus dichotomus, Catagonus wagneri and Ozotocerus bezoarticus). The biogeographic node was found in the Northwestern Colombia. The geological events such as tectonism and volcanism that occurred through the Neogene and mainly in the Pleistocene caused fragmentation, diversification and endemism of biota. The biogeographic node in Colombia occurred within a zone of convergence. This node emphasized the complexity of the area and it contains biotic elements with different origins, which represent a special condition for the establishment of priority conservation areas.

Immigration and the Challenge of Education: A Social Drama Analysis in South Central Los Angeles. Education, Politics and Public Life

ERIC Educational Resources Information Center

Jaramillo, Nathalia E.

2012-01-01

Part enthnograpy and part testimony, this book analyzes a school setting and community from the standpoint of a group of immigrant mothers (las madres) in South Central Los Angeles who were concerned about the education of their children and the violence in their communities. Written in both the first and third person, in Spanish and English, the…

Antimicrobial susceptibility and emerging resistance determinants (blaCTX-M, rmtB, fosA3) in clinical isolates from urinary tract infections in the Bolivian Chaco.

PubMed

Bartoloni, Alessandro; Sennati, Samanta; Di Maggio, Tiziana; Mantella, Antonia; Riccobono, Eleonora; Strohmeyer, Marianne; Revollo, Carmen; Villagran, Ana Liz; Pallecchi, Lucia; Rossolini, Gian Maria

2016-02-01

Bolivia is among the lowest-resourced South American countries, with very few data available on antibiotic resistance in bacterial pathogens. The phenotypic and molecular characterization of bacterial isolates responsible for urinary tract infections (UTIs) in the Bolivian Chaco are reported here. All clinical isolates from UTIs collected in the Hospital Basico Villa Montes between June 2010 and January 2014 were analyzed (N=213). Characterization included susceptibility testing, extended-spectrum beta-lactamase (ESBL) detection, identification of relevant resistance determinants (e.g., CTX-M-type ESBLs, 16S rRNA methyltransferases, glutathione S-transferases), and genotyping of CTX-M producers. Very high resistance rates were observed. Overall, the lowest susceptibility was observed for trimethoprim-sulphamethoxazole, tetracycline, nalidixic acid, amoxicillin-clavulanic acid, ciprofloxacin, and gentamicin. Of E. coli and K. pneumoniae, 11.6% were ESBL producers. Resistance to nitrofurantoin, amikacin, and fosfomycin remained low, and susceptibility to carbapenems was fully preserved. CTX-M-15 was the dominant CTX-M variant. Four E. coli ST131 (two being H30-Rx) were identified. Of note, isolates harbouring rmtB and fosA3 were detected. Bolivia is not an exception to the very high resistance burden affecting many South American countries. Optimization of alternative approaches to monitor local antibiotic resistance trends in resource-limited settings is strongly encouraged to support the implementation of effective empiric treatment guidelines. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Classification of immature mosquito species according to characteristics of the larval habitat in the subtropical province of Chaco, Argentina.

PubMed

Stein, Marina; Ludueña-Almeida, Francisco; Willener, Juana Alicia; Almirón, Walter Ricardo

2011-06-01

To classify mosquito species based on common features of their habitats, samples were obtained fortnightly between June 2001-October 2003 in the subtropical province of Chaco, Argentina. Data on the type of larval habitat, nature of the habitat (artificial or natural), size, depth, location related to sunlight, distance to the neighbouring houses, type of substrate, organic material, vegetation and algae type and their presence were collected. Data on the permanence, temperature, pH, turbidity, colour, odour and movement of the larval habitat's water were also collected. From the cluster analysis, three groups of species associated by their degree of habitat similarity were obtained and are listed below. Group 1 consisted of Aedes aegypti. Group 2 consisted of Culex imitator, Culex davisi, Wyeomyia muehlensi and Toxorhynchites haemorrhoidalis separatus. Within group 3, two subgroups are distinguished: A (Psorophora ferox, Psorophora cyanescens, Psorophora varinervis, Psorophora confinnis, Psorophora cingulata, Ochlerotatus hastatus-oligopistus, Ochlerotatus serratus, Ochlerotatus scapularis, Culex intrincatus, Culex quinquefasciatus, Culex pilosus, Ochlerotatus albifasciatus, Culex bidens) and B (Culex maxi, Culex eduardoi, Culex chidesteri, Uranotaenia lowii, Uranotaenia pulcherrima, Anopheles neomaculipalpus, Anopheles triannulatus, Anopheles albitarsis, Uranotaenia apicalis, Mansonia humeralis and Aedeomyia squamipennis). Principal component analysis indicates that the size of the larval habitats and the presence of aquatic vegetation are the main characteristics that explain the variation among different species. In contrast, water permanence is second in importance. Water temperature, pH and the type of larval habitat are less important in explaining the clustering of species.

How does a viviparous semifossorial lizard reproduce? Ophiodes intermedius (Squamata: Anguidae) from subtropical climate in the Wet Chaco region of Argentina.

PubMed

Ortiz, Martín A; Boretto, Jorgelina M; Ibargüengoytía, Nora R

2017-04-01

The best predictors of reproductive patterns are commonly associated with climate factors, but evolutionary history also plays an important role. The semifossorial and viviparous lizard Ophiodes intermedius from the Wet Chaco region of Argentina showed an annual cycle with asynchrony between males and females and an unusual pattern for subtropical climates, with vitellogenesis beginning in autumn, ovulation and copulation in spring, and births occurring in summer. Males exhibited annual variation of testicular size associated with spermatogenic activity, reaching their maximum gonadal activity in late summer (March), but sperm storage in the epididymis and/or deferent duct occurred throughout the year. Females showed an extended reproductive cycle beginning in mid-autumn (May) with vitellogenesis and finishing with births from late spring to mid-summer (December to February). Litter size varied from 4 to 9 offspring. Females reached sexual maturity at a larger snout-vent length and, overall, showed greater body size than males, while males exhibited larger heads than females. Fat body cycles indicated that females use lipid reserves to support vitellogenesis and embryo development, while males allocate lipid resources to the search for females, courtship and copulation rather than to gametogenesis. Ophiodes intermedius differed from other species of the genus in litter size, gestation period, timing of birth and the minimum size at sexual maturity, probably as a result of the influence of ecological, historical and phylogenetic factors. Copyright © 2017 Elsevier GmbH. All rights reserved.

[Not Available].

PubMed

Germán Díaz, Marta; Moreno Villares, José Manuel; Gomis Muñoz, Pilar

2016-07-19

Introducción: la nutrición parenteral domiciliaria se ha convertido en un punto clave en el tratamiento de pacientes con fracaso intestinal crónico. A pesar de los importantes avances que se han producido en las últimas décadas, tanto en los accesos vasculares, como en las soluciones empleadas, las infecciones asociadas a catéter venoso central siguen constituyendo una de las complicaciones más importantes. Dentro de las estrategias para la prevención o el tratamiento de estas infecciones se encuentra el empleo de sellados con antisépticos, como el etanol o la taurolidina, o de antibióticos.Objetivo: el objetivo de este artículo es revisar la evidencia disponible sobre el empleo de sellados con antisépticos o antibióticos en el manejo de pacientes pediátricos con nutrición parenteral domiciliaria.Material y métodos: el uso de sellados con etanol o taurolidina para prevenir el desarrollo de infecciones asociadas a catéter central estaría indicado en pacientes con nutrición parenteral domiciliaria que hayan tenido más de una infección en el año anterior o que se consideren pacientes de riesgo. Los sellados con antibióticos están indicados en el tratamiento de bacteriemias asociadas a catéter central producidas por S. coagulasa-negativo o gramnegativos, asociados a un tratamiento sistémico, siempre que sea posible, con el fin de salvar el catéter. Se debería llevar a cabo la retirada del mismo cuando existan signos de infección del punto de entrada o del trayecto subcutáneo, o cuando el germen responsable de la infección sea S. aureus o Cándida.Conclusión: a pesar de que la fuerza de la evidencia sobre la eficacia del sellado en la prevención o el tratamiento de infecciones asociadas al catéter es limitada, tanto en el niño como en el adulto, cada vez existen más datos a usar esta alternativa en pacientes con nutrición parenteral domiciliaria en los que la atención y salvaguarda de los catéteres es primordial.

La problematica de la demarcacion entre ciencia y pseudociencia y sus implicaciones en la educacion cientifica

NASA Astrophysics Data System (ADS)

Jimenez Tolentino, Dinorah

2011-12-01

En la sociedad prevalece una tendencia generalizada hacia la inclusion de creencias y practicas pseudocientificas. Esta investigacion responde a la necesidad de analizar como la proliferacion de las pseudociencias afecta la vision que tienen los estudiantes universitarios sobre las ciencias naturales. A tales efectos, la investigadora describe las concepciones epistemologicas que tienen los estudiantes sobre las ciencias y las pseudociencias e identifica los criterios de demarcacion, entre un area y otra, que se derivan de estas concepciones. De igual modo, esta identifica las creencias y practicas pseudocientificas de mayor arraigo entre los estudiantes, destacando, a su vez, la razon de ser de las mismas. Por ultimo, la investigadora analiza las implicaciones educativas de la problematica de la demarcacion entre ciencia y pseudociencia. La investigacion es de naturaleza mixta, enmarcada en los paradigmas empirico- analitico y cualitativo. El proceso investigativo se llevo a cabo mediante la administracion del cuestionario Criterios para la demarcacion entre ciencia y pseudociencia. La parte cualitativa estuvo enmarcada en el diseno de estudio de caso, recopilando informacion mediante entrevistas semiestructuradas en dos grupos focales. La poblacion de estudio estuvo constituida por estudiantes universitarios del nivel subgraduado de la Universidad Central de Bayamon. Los resultados del estudio reflejaron las concepciones erroneas de los estudiantes sobre la naturaleza de las ciencias y las pseudociencias. Con respecto a la demarcacion entre ciencia y pseudociencia, el criterio imperante entre los universitarios es el de la verificabilidad, considerando la aplicacion del metodo cientifico como el metodo para demostrar la veracidad de las teorias cientificas. Las creencias y practicas pseudocientificas no son muy frecuentes entre los universitarios. Estos atribuyen las mismas a la prevalencia de elementos supersticiosos y al engano a que es sometida la poblacion por quienes promueven estas practicas. A partir de los resultados, la investigadora concluye que la problematica sobre la demarcacion entre ciencia y pseudociencia esta influenciada por unos procesos de ensenanza enfocados en una vision distorsionada de la ciencia, producto de la no integracion de los aspectos filosoficos, historicos y sociales de la misma.

Chagas' disease in Aboriginal and Creole communities from the Gran Chaco Region of Argentina: Seroprevalence and molecular parasitological characterization.

PubMed

Lucero, R H; Brusés, B L; Cura, C I; Formichelli, L B; Juiz, N; Fernández, G J; Bisio, M; Deluca, G D; Besuschio, S; Hernández, D O; Schijman, A G

2016-07-01

Most indigenous ethnias from Northern Argentina live in rural areas of "the Gran Chaco" region, where Trypanosoma cruzi is endemic. Serological and parasitological features have been poorly characterized in Aboriginal populations and scarce information exist regarding relevant T. cruzi discrete typing units (DTU) and parasitic loads. This study was focused to characterize T. cruzi infection in Qom, Mocoit, Pit'laxá and Wichi ethnias (N=604) and Creole communities (N=257) inhabiting rural villages from two highly endemic provinces of the Argentinean Gran Chaco. DNA extracted using Hexadecyltrimethyl Ammonium Bromide reagent from peripheral blood samples was used for conventional PCR targeted to parasite kinetoplastid DNA (kDNA) and identification of DTUs using nuclear genomic markers. In kDNA-PCR positive samples from three rural Aboriginal communities of "Monte Impenetrable Chaqueño", minicircle signatures were characterized by Low stringency single primer-PCR and parasitic loads calculated using Real-Time PCR. Seroprevalence was higher in Aboriginal (47.98%) than in Creole (27.23%) rural communities (Chi square, p=4.e(-8)). A low seroprevalence (4.3%) was detected in a Qom settlement at the suburbs of Resistencia city (Fisher Exact test, p=2.e(-21)).The kDNA-PCR positivity was 42.15% in Aboriginal communities and 65.71% in Creole populations (Chi square, p=5.e(-4)). Among Aboriginal communities kDNA-PCR positivity was heterogeneous (Chi square, p=1.e(-4)). Highest kDNA-PCR positivity (79%) was detected in the Qom community of Colonia Aborigen and the lowest PCR positivity in two different surveys at the Wichi community of Misión Nueva Pompeya (33.3% in 2010 and 20.8% in 2014). TcV (or TcII/V/VI) was predominant in both Aboriginal and Creole communities, in agreement with DTU distribution reported for the region. Besides, two subjects were infected with TcVI, one with TcI and four presented mixed infections of TcV plus TcII/VI. Most minicircle signatures clustered according to their original localities, but in a few cases, signatures from one locality clustered with signatures from other village, suggesting circulation of the same strains in the area. Parasitic loads ranged from undetectable to around 50 parasite equivalents/mL, showing higher values than those generally observed in chronic Chagas disease patients living in urban centers of Argentina. Our findings reveal the persistence of high levels of infection in these neglected populations. Copyright © 2016. Published by Elsevier B.V.

Provenance and fate of arsenic and other solutes in the Chaco-Pampean Plain of the Andean foreland, Argentina: From perspectives of hydrogeochemical modeling and regional tectonic setting

NASA Astrophysics Data System (ADS)

Raychowdhury, Nilasree; Mukherjee, Abhijit; Bhattacharya, Prosun; Johannesson, Karen; Bundschuh, Jochen; Sifuentes, Gabriela Bejarano; Nordberg, Erika; Martin, Raúl A.; Storniolo, Angel del Rosario

2014-10-01

Extensive arsenic (As) enriched groundwater is known to occur in the aquifers of the Chaco-Pampean Plain of Argentina. Previous studies speculated that the As mobilization in these groundwaters was a direct result of their elevated pH and oxidative conditions. The volcanic glass layers present in the aquifer matrix were hypothesized as one of the possible sources of As to the groundwaters. Here, we examine the groundwater chemistry of the Santiago del Estero province of Chaco-Pampean Plains of Argentina, and test these hypotheses by using hydrogeochemical modeling within the framework of the regional geologic-tectonic setting. The study area is located in the active foreland of the Andean orogenic belt, which forms a continental arc setting, and is dotted with several hot springs. Rhyolitic volcanic glass fragments derived from arc volcanism are abundant within the aeolian-fluvial aquifer sediments, and are related to the paleo-igneous extrusion in the vicinity. Hydrogeochemical analyses show that the groundwater is in predominantly oxidative condition. In addition, some of the groundwaters exhibit very high Na, Cl- and SO42- concentrations. It is hypothesized in this study that the groundwater chemistry has largely evolved by dissolution of rhyolitic volcanic glass fragments contained within the aquifer sediments along with mixing with saline surface waters from, adjoining salinas, which are thought to be partially evaporated remnants of a paleo inland sea. Flow path modeling, stability diagrams, and thermodynamic analyses undertaken in this study indicate that the dominant evolutionary processes include ion exchange reactions, chemical weathering of silicate and evaporites, in monosialitization-dominated weathering. Geochemical modeling predicts that plagioclase feldspar and volcanic glass are the major solids phases that contribute metal cations and dissolved silica to the local groundwaters. Co-influxed oxyanions, with similar ionic radii and structure (e.g. Mo, Si, V, PO43-), compete with As for mineral surface site, leading to As mobilization to the groundwaters (without considering the influence of microbial activities). Further, the transition of the Ca-rich groundwater to Na-rich groundwater, by mixing with water from the salinas and/or evaporative concentration, might also have led to counter-ion effects (a type of ion exchange reactions), and hence, further enrichment of groundwater by As. Some of the As may also have been contributed from mixing of meteoric water with magmatic-sourced water in the geothermal springs.

Biostratigraphy and petrography of upper Paleozoic rocks of Sierra Las Pintas, northern Baja California

NASA Astrophysics Data System (ADS)

Navas-Parejo, Pilar; Lara-Peña, R. Aaron; Torres-Martínez, Miguel Angel; Martini, Michelangelo

2018-07-01

A transported crinoid fauna is herein described for the first time in the Paleozoic succession cropping out in the Sierra Las Pintas, northern Baja California, northwestern Mexico. The fossil association includes Heterostelechus texanus Moore and Jeffords, Preptopremnum laeve? Moore and Jeffords, and Mooreanteris perforatus Moore and Jeffords, which indicates a Middle Pennsylvanian-early Permian time-averaged age. The studied area corresponds with the northernmost outcrop of definitely late Paleozoic deep-water facies in northwestern Mexico and the southern United States. Petrographic analyses indicate that the studied metasandstones were primarily derived from high-grade metamorphic rocks and from a shallow-water platform environment dominated by crinoid meadows. These results allow the correlation of the studied metasedimentary rocks with the Carboniferous Rancho Nuevo Formation of the Sonora allochthon, which crops out in central Sonora. The Sonora allochthon includes an Early Ordovician-Late Pennsylvanian sedimentary succession that was deposited in the oceanic basin located south of the Laurentian craton. Therefore, upper Paleozoic metasedimentary rocks of the Sierra Las Pintas were deposited along the same continental margin of Laurentia as those rocks in the Sonora allochthon, and were mostly derived from metamorphic rocks of the continental craton and by the typical Carboniferous encrinites, which characterize the shallow-water rocks of central and northern Sonora.

Prevalence of Escherichia coli O157:H7 From House Flies (Diptera: Muscidae) and Dairy Samples in North Central Florida1.

PubMed

Burrus, Roxanne G; Hogsette, Jerome A; Kaufman, Phillip E; Maruniak, James E; Simonne, Amy H; Mai, Volker

2017-05-01

La detección de Escherichia coli O157:H7 en las lecherías es importante para mejorar la seguridad de los productos lácteos, y se ha llevado a cabo principalmente mediante el aislamiento de las bacterias a partir de las muestras de estiércol. Sin embargo, los componentes biliares presentes en el estiércol complica la identificación genética utilizando la técnica del PCR, y el aislamiento microbiológico se dificulta por la presencia de bacterias competidoras que comparten características microbiológicas similares. El aislamiento de E. coli O157:H7 a partir de la mosca doméstica evita las dificultades asociadas con el estiércol del ganado. El aislamiento de patógenos a partir de las moscas domésticas proporciona información adicional sobre el potencial impacto epidemiológico de la dispersión de la mosca doméstica en la distribución de patógenos, ya que las moscas domésticas se dispersan desde las lecherías donde la E. coli O157:H7 existe en forma endémica en el ganado. En este estudio, se encontró que las moscas domésticas son 2,6 veces más sensibles para la detección de E. coli O157:H7 en las lecherías. Las moscas son más fáciles de capturar y manejar que el estiércol, y deberían ser utilizadas en cualquier ensayo para detectar E. coli O157:H7 en las lecherías y otros establecimientos. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

Clinical outcomes in male patients with lactotroph adenomas who required pituitary surgery: a retrospective single center study.

PubMed

Liu, Winnie; Zahr, Roula Shraiky; McCartney, Shirley; Cetas, Justin S; Dogan, Aclan; Fleseriu, Maria

2018-06-23

Lactotroph adenomas (LA) are the most frequently encountered pituitary tumors. Although more frequently observed in women, LAs in men were recently included in a more aggressive category regardless of histological grading, by the WHO. We aimed to perform a rigorous retrospective review of a single center's pre-operative evaluation, patient characteristics and outcomes of male LAs patients requiring pituitary surgery. A retrospective review, over 11 years, of patients who underwent resection of a pituitary adenoma at a single center was conducted. Predictors of persistent disease in male LAs patients along with a comparison to predictors of silent corticotroph adenomas (SCAs) patients who also underwent surgery at the center was also conducted. Thirty-one male patients with LAs were identified. When compared to SCAs patients, LAs male patients were younger (41 vs. 50 years of age, p = 0.01). Men with LAs had more invasive tumors (75% vs. 44.7% p = 0.02). More LAs in men had residual tumor after surgery than patients with SCA (92.6% vs. 42.1%, p < 0.001). Male patients with LAs and patients with SCA had similar rates of requiring additional surgery (28.9% vs. 24.1%, p = NS) and radiation therapy (18.4% vs. 19.4%, p = NS). High rates of DA resistance, invasive tumors and postoperative residual disease in male patients with LA who required surgery are shown. Surgery improved optic chiasm compression, PRL level and central hypogonadism but, not surprisingly, failed to normalize other pituitary hormones and/or eliminate need for DA therapy.

THE NEVADA GEOSPATIAL DATA BROWSER

EPA Science Inventory

The Landscape Ecology Branch of the U.S. Environmental Protection Agency (Las Vegas, NV) has developed the Nevada Geospatial Data Browser, a spatial data archive to centralize and distribute the geospatial data used to create the land cover, vertebrate habitat models, and land o...

Hydrogeologic uncertainties and policy implications: The Water Consumer Protection Act of Tucson, Arizona, USA

NASA Astrophysics Data System (ADS)

Wilson, L. G.; Matlock, W. G.; Jacobs, K. L.

The 1995 Water Consumer Protection Act of Tucson, Arizona, USA (hereafter known as the Act) was passed following complaints from Tucson Water customers receiving treated Central Arizona Project (CAP) water. Consequences of the Act demonstrate the uncertainties and difficulties that arise when the public is asked to vote on a highly technical issue. The recharge requirements of the Act neglect hydrogeological uncertainties because of confusion between "infiltration" and "recharge." Thus, the Act implies that infiltration in stream channels along the Central Wellfield will promote recharge in the Central Wellfield. In fact, permeability differences between channel alluvium and underlying basin-fill deposits may lead to subjacent outflow. Additionally, even if recharge of Colorado River water occurs in the Central Wellfield, groundwater will become gradually salinized. The Act's restrictions on the use of CAP water affect the four regulatory mechanisms in Arizona's 1980 Groundwater Code as they relate to the Tucson Active Management Area: (a) supply augmentation; (b) requirements for groundwater withdrawals and permitting; (c) Management Plan requirements, particularly mandatory conservation and water-quality issues; and (d) the requirement that all new subdivisions use renewable water supplies in lieu of groundwater. Political fallout includes disruption of normal governmental activities because of the demands in implementing the Act. Résumé La loi de 1995 sur la protection des consommateurs d'eau de Tucson (Arizona, États-Unis) a été promulguée à la suite des réclamations des consommateurs d'eau de Tucson alimentés en eau traitée à partir à la station centrale d'Arizona (CAP). Les conséquences de cette loi montrent les incertitudes et les difficultés qui apparaissent lorsque le public est appeléà voter sur un problème très technique. Les exigences de la loi en matière de recharge négligent les incertitudes hydrogéologiques du fait de la confusion entre "infiltration" et "recharge". C'est ainsi que la loi laisse entendre que l'infiltration à partir des lits de rivières le long du champ captant central favorise la recharge de cette zone. En réalité, les différences de perméabilité entre les alluvions du lit et les dépôts sous-jacents remplissant le bassin peuvent provoquer un écoulement sous-jacent. En outre, même si une recharge par l'eau de la rivière Colorado se produit dans cette zone, la nappe sera progressivement salifiée. Les restrictions imposées par la loi quant à l'utilisation de l'eau de la station centrale d'Arizona affectent les quatre outils réglementaires du Code des eaux souterraines de l'Arizona de 1980, en ce qu'ils concernent la zone de gestion active de Tucson: (a) l'augmentation de l'approvisionnement (b) les conditions requises pour les prélèvements d'eau souterraine et les autorisations; (c) les conditions requises pour le plan de gestion, en particulier la pérennité du concessionnaire et les résultats en matière de qualité de l'eau et (d) la condition que tous les nouveaux districts aient recours à des ressources en eau renouvelables à la place de l'eau souterraine. Les demandes concernant la mise en oeuvre de la loi ont conduit jusqu'à l'arrêt des activités normales des instances politiques. Resumen El Acta de Protección de los Usuarios de Agua de Tucson, Arizona (EE.UU.) de 1995 (el Acta) se aprobó a raíz de las quejas de los usuarios de agua de Tucson que recibían agua tratada por el Proyecto de Arizona Central (CAP). Las consecuencias del Acta demuestran las incertidumbres y dificultades que se producen cuando se le pide al público que vote sobre temas muy técnicos. Los requerimientos de recarga del Acta desprecian incertidumbres hidrogeológicas al confundir entre "infiltración" y "recarga". Así, el Acta dice que la infiltración en los canales de los arroyos a lo largo del Campo de Producción Central aumentará la recarga a dicho campo. De hecho, la diferencia de permeabilidad entre el canal aluvial y los depósitos de relleno subyacentes puede provocar descarga subyacente. Además, incluso si el Río Colorado recargase este Campo Central, el agua subterránea se salinizaría progresivamente. Las restricciones del Acta sobre el uso del agua del CAP afectan los cuatro mecanismos legales del Código de Aguas Subterráneas de Arizona de 1980 relacionados con el Área de Gestión Activa de Tucson: (a) aumento del suministro; (b) requisitos y permisos para la extracción de aguas subterráneas (c) necesidades del Plan de Gestión, particularmente la conservación obligatoria y temas de calidad de aguas; y (d) la obligación de que todas las nuevas subdivisiones usen agua con suministro renovable en lugar de subterránea. Como problemas adicionales se incluye la perturbación de las actividades políticas normales como consecuencia de las demandas para aprobar y poner en marcha el Acta.

Disentangling the effects of shrubs and herbivores on tree regeneration in a dry Chaco forest (Argentina).

PubMed

Tálamo, Andrés; Barchuk, Alicia H; Garibaldi, Lucas A; Trucco, Carlos E; Cardozo, Silvana; Mohr, Federico

2015-07-01

Successful persistence of dry forests depends on tree regeneration, which depends on a balance of complex biotic interactions. In particular, the relative importance and interactive effects of shrubs and herbivores on tree regeneration are unclear. In a manipulative study, we investigated if thornless shrubs have a direct net effect, an indirect positive effect mediated by livestock, and/or an indirect negative effect mediated by small vertebrates on tree regeneration of two key species of Chaco forest (Argentina). In a spatial association study, we also explored the existence of net positive interactions from thorny and thornless shrubs. The number of Schinopsis lorentzii seedlings was highest under artificial shade with native herbivores and livestock excluded. Even excluding livestock, no seedlings were found with natural conditions (native herbivores present with natural shade or direct sunlight) at the end of the experiment. Surprisingly, seedling recruitment was not enhanced under thornless shrubs, because there was a complementary positive effect of shade and interference. Moreover, thornless shrubs had neither positive nor negative effects on regeneration of S. lorentzii. Regeneration of Aspidosperma quebracho-blanco was minimal in all treatments. In agreement with the experiment, spatial distributions of saplings of both tree species were independent of thornless shrubs, but positively associated with thorny shrubs. Our results suggest that in general thornless shrubs may have a negligible effect and thorny shrubs a net positive effect on tree regeneration in dry forests. These findings provide a conceptual framework for testing the impact of biotic interactions on seedling recruitment in other dry forests.

Deforestation impacts on soil organic carbon stocks in the Semiarid Chaco Region, Argentina.

PubMed

Villarino, Sebastián Horacio; Studdert, Guillermo Alberto; Baldassini, Pablo; Cendoya, María Gabriela; Ciuffoli, Lucía; Mastrángelo, Matias; Piñeiro, Gervasio

2017-01-01

Land use change affects soil organic carbon (SOC) and generates CO 2 emissions. Moreover, SOC depletion entails degradation of soil functions that support ecosystem services. Large areas covered by dry forests have been cleared in the Semiarid Chaco Region of Argentina for cropping expansion. However, deforestation impacts on the SOC stock and its distribution in the soil profile have been scarcely reported. We assessed these impacts based on the analysis of field data along a time-since-deforestation-for-cropping chronosequence, and remote sensing indices. Soil organic C was determined up to 100cm depth and physically fractionated into mineral associated organic carbon (MAOC) and particulate organic C (POC). Models describing vertical distribution of SOC were fitted. Total SOC, POC and MAOC stocks decreased markedly with increasing cropping age. Particulate organic C was the most sensitive fraction to cultivation. After 10yr of cropping SOC loss was around 30%, with greater POC loss (near 60%) and smaller MAOC loss (near 15%), at 0-30cm depth. Similar relative SOC losses were observed in deeper soil layers (30-60 and 60-100cm). Deforestation and subsequent cropping also modified SOC vertical distribution. Soil organic C loss was negatively associated with the proportion of maize in the rotation and total crop biomass inputs, but positively associated with the proportion of soybean in the rotation. Without effective land use polices, deforestation and agricultural expansion can lead to rapid soil degradation and reductions in the provision of important ecosystem services. Copyright © 2016 Elsevier B.V. All rights reserved.

The Bolivian source rocks: Sub Andean Zone-Madre de Dios-Chaco

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moretti, I.; Montemurro, G.; Aguilera, E.

A complete study of source rocks has been carried out in the Bolivian foothills and foreland (Sub Andean Zone, Chaco and Madre de Dios) in order to quantify the petroleum potential of the area. Besides the classical mid-Devonian source rocks (Tequeje Formation in the north, Limoncito Formation in the center and Los Monos Formation in the south), others are important: the Tomachi Formation (late Devonian) in the north and the Copacabana Formation (Upper Carboniferous-lower Permian) in the northern Sub Andean Zone. Both show an excellent potential with S{sub 2} over 50 mg HC/g and average values higher than 10 mgmore » HC/g over few hundred meters. The Latest Cretaceous Flora Formation present locally a high potential but is very thin. Almost all the source rocks matured during the Neogene due to the subsidence in the Andean foreland and in the piggyback basins, and are thus involved on the current petroleum system. Silurian and Lower Paleozoic units also contain thick shale beds, but these source rocks were mature before the Jurassic in the south of the country. In the center, the Silurian is not nowadays overmature and may play an important role. The different zones are compared based on their Source Potential Index which indicates that the richest areas are the northern Sub Andean Zone and the Madre de Dios basin with SPI greater than 10 t/m{sup 2}. Since these two areas remain almost unexplored, these results allow us to be optimistic about the possibilities for future exploration.« less

Seasonal dynamics, geographical range size, hosts, genetic diversity and phylogeography of Amblyomma sculptum in Argentina.

PubMed

Tarragona, Evelina L; Sebastian, Patrick S; Saracho Bottero, María N; Martinez, Emilia I; Debárbora, Valeria N; Mangold, Atilio J; Guglielmone, Alberto A; Nava, Santiago

2018-04-27

The aim of this work was to generate knowledge on ecological aspects of Amblyomma sculptum in Argentina, such as seasonal dynamics, geographical range size, hosts, genetic diversity and phylogeography. Adult and immature A. sculptum ticks were collected in different localities of Argentina to know the geographical range size and hosts. The genetic diversity of this tick was studied through analyses of 16S rDNA sequences. To describe the seasonal dynamics, free-living ticks were monthly collected from October 2013 to October 2015. A. sculptum shows a marked ecological preference for Chaco Húmedo eco-region and "Albardones" forest of the great rivers in the wetlands in the Chaco Biogeographical Province, and for Selvas Pedemontanas and Selva Montana in the Yungas Biogeographical Province. This species has low host specificity, and it has large wild and domestic mammals as principal hosts to both immature and adult stages. Amblyomma sculptum is characterized by a one-year life cycle. Larvae peak in early winter, nymphs peaked during mid-spring, and adults during late summer and mid-summer. The genetic divergence was low and the total genetic variability was attributable to differences among populations. This fact could be associated to stochastics process linked to micro-habitat variations that could produce a partial restriction to gene flow among populations. The geographic regions do not contribute much to explain the A. sculptum population genetic structure, with an ancestral haplotype present in most populations, which gives rise to the rest of the haplotypes denoting a rapid population expansion. Copyright © 2018. Published by Elsevier GmbH.

Knowledge, attitudes, and practices towards epilepsy among general practitioners in rural Bolivia: Results before and after a training program on epilepsy.

PubMed

Giuliano, Loretta; Cicero, Calogero Edoardo; Padilla, Sandra; Camargo, Mario; Sofia, Vito; Zappia, Mario; Bartoloni, Alessandro; Crespo Gómez, Elizabeth Blanca; Nicoletti, Alessandra

2018-04-22

Epilepsy represents a major health problem in low- and middle-income countries where treatment gap (TG) levels are high. The reduction of epilepsy TG in the rural area of the Chaco region, Plurinational State of Bolivia, has been the aim of many projects based on the reinforcement of the primary care setting. To plan educational campaigns directed to the healthcare professionals, it is necessary to establish their baseline knowledge level. The objective of our study was to assess the baseline level of knowledge, attitudes, and practices (KAP) towards epilepsy among general practitioners (GPs) of the rural communities of the Chaco region. The study was conducted in three departments of Bolivia. All the GPs living in these areas were invited to participate in the study consisting of two training modules six months apart from each other, each with two-day duration. They answered a validated questionnaire to evaluate the KAP towards epilepsy before and after the courses. Fifty GPs [30 men (60%); mean age: 32.1±5.8years] participated in the first training course. After six months, 31 GPs (62%) [19 men (61.3%); mean age: 33±5.0years] participated in the second module. Before the training, the majority of GPs declared a low level of satisfaction about their epilepsy knowledge, which improved after the courses. A change in practices was recorded after the training, with an increased confidence to manage antiepileptic treatment. Our study showed the significant impact of specific training programs on epilepsy among GPs. Copyright © 2017 Elsevier Inc. All rights reserved.

Improved Chemical Control of Chagas Disease Vectors in the Dry Chaco Region

PubMed Central

CECERE, MARÍA CARLA; VAZQUEZ-PROKOPEC, GONZALO M.; CEBALLOS, LEONARDO A.; BORAGNO, SILVANA; ZÁRATE, JOAQUÍN E.; KITRON, URIEL; GÜRTLER, RICARDO E.

2013-01-01

The effectiveness of two doses of suspension concentrate (SC) pyrethroid insecticides in suppressing peridomestic populations of Triatoma infestans (Klug) was evaluated in 28 rural communities located in Santiago del Estero province, northwestern Argentina, including 388 houses and 1,516 identified sites. Four treatments were randomly assigned to peridomiciles within each community: 5% SC β-cypermethrin at standard (S, 50 mg active ingredient [AI]/m2) and double dose (2S), and 2.5% SC deltamethrin at standard (D, 25 mg [AI]/m2) and double dose (2D). Simultaneously, we assessed the effects of both pyrethroids applied at standard doses against domestic infestations. Bug infestation at the site level was assessed by timed manual collections with a dislodging agent at baseline, 13 and 21 mo postspraying (MPS). In domiciles, D and S nearly suppressed all T. infestans infestations up to 21 MPS. In peridomestic sites infested before interventions, multiple logistic regression analysis showed that site-level reinfestation at 13 MPS was significantly lower for treatment 2D (1%) than for other treatments, whereas 2S (6%), D (5%), and S (14%) did not differ significantly between them. The risk of reinfestation after spraying was significantly greater in goat or pig corrals than in other peridomestic ecotopes (in which treatments did not differ significantly), and in sites infested before interventions than in uninfested sites. The application of SC deltamethrin at double dose in goat or pig corrals may suppress T. infestans foci and achieve more sustained effects in the dry Chaco. PMID:23540129

Impact of community-based vector control on house infestation and Trypanosoma cruzi infection in Triatoma infestans, dogs and cats in the Argentine Chaco.

PubMed

Cardinal, M V; Lauricella, M A; Marcet, P L; Orozco, M M; Kitron, U; Gürtler, R E

2007-09-01

The relative impact of two community-based vector control strategies on house infestation by Triatoma infestans and Trypanosoma cruzi infection in bugs, domestic dogs and cats was assessed in two neighboring rural areas comprising 40 small villages and 323 houses in one of the regions most endemic for Chagas disease in northern Argentina. The prevalence and abundance of domestic infestation were 1.5- and 6.5-fold higher, respectively, in the area under pulsed, non-supervised control actions operating under the guidelines of the National Vector Control Program (NCVP) than in the area under sustained, supervised surveillance carried out jointly by the UBA research team and NCVP. The prevalence of infestation and infection varied widely among village groups within each area. In the pulsed control area, the prevalence of infection in bugs, dogs and cats was two- to three-fold higher than in the area under sustained surveillance, most of the infected animals qualified as autochthonous cases, and evidence of recent transmission was observed. Infection was highly aggregated at the household level and fell close to the 80/20 rule. Using multiple logistic regression analysis clustered by household, infection in dogs was associated positively and significantly with variables reflecting local exposure to infected T. infestans, thus demonstrating weak performance of the vector surveillance system. For high-risk areas in the Gran Chaco region, interruption of vector-mediated domestic transmission of T. cruzi requires residual insecticide spraying that is more intense, of a higher quality and sustained in time, combined with community participation and environmental management measures.

87Sr/86Sr sourcing of ponderosa pine used in Anasazi great house construction at Chaco Canyon, New Mexico

USGS Publications Warehouse

Reynolds, Amanda C.; Betancourt, Julio L.; Quade, Jay; Patchett, P. Jonathan; Dean, Jeffery S.; Stein, John

2005-01-01

Previous analysis of 87Sr/86Sr ratios shows that 10th through 12th century Chaco Canyon was provisioned with plant materials that came from more than 75 km away. This includes (1) corn (Zea mays) grown on the eastern flanks of the Chuska Mountains and floodplain of the San Juan River to the west and north, and (2) spruce (Picea sp.) and fir (Abies sp.) beams from the crest of the Chuska and San Mateo Mountains to the west and south. Here, we extend 87Sr/86Sr analysis to ponderosa pine (Pinus ponderosa) prevalent in the architectural timber at three of the Chacoan great houses (Pueblo Bonito, Chetro Ketl, Pueblo del Arroyo). Like the architectural spruce and fir, much of the ponderosa matches the 87Sr/86Sr ratios of living trees in the Chuska Mountains. Many of the architectural ponderosa, however, have similar ratios to living trees in the La Plata and San Juan Mountains to the north and Lobo Mesa/Hosta Butte to the south. There are no systematic patterns in spruce/fir or ponderosa provenance by great house or time, suggesting the use of stockpiles from a few preferred sources. The multiple and distant sources for food and timber, now based on hundreds of isotopic values from modern and archeological samples, confirm conventional wisdom about the geographic scope of the larger Chacoan system. The complexity of this procurement warns against simple generalizations based on just one species, a single class of botanical artifact, or a few isotopic values.

87Sr/86Sr sourcing of ponderosa pine used in Anasazi great house construction at Chaco Canyon, New Mexico

USGS Publications Warehouse

Reynolds, A.C.; Betancourt, J.L.; Quade, Jay; Patchett, P.J.; Dean, J.S.; Stein, J.

2005-01-01

Previous analysis of 87Sr/86Sr ratios shows that 10th through 12th century Chaco Canyon was provisioned with plant materials that came from more than 75 km away. This includes (1) corn (Zea mays) grown on the eastern flanks of the Chuska Mountains and floodplain of the San Juan River to the west and north, and (2) spruce (Picea sp.) and fir (Abies sp.) beams from the crest of the Chuska and San Mateo Mountains to the west and south. Here, we extend 87Sr/86Sr analysis to ponderosa pine (Pinus ponderosa) prevalent in the architectural timber at three of the Chacoan great houses (Pueblo Bonito, Chetro Ketl, Pueblo del Arroyo). Like the architectural spruce and fir, much of the ponderosa matches the 87Sr/86Sr ratios of living trees in the Chuska Mountains. Many of the architectural ponderosa, however, have similar ratios to living trees in the La Plata and San Juan Mountains to the north and Lobo Mesa/Hosta Butte to the south. There are no systematic patterns in spruce/fir or ponderosa provenance by great house or time, suggesting the use of stockpiles from a few preferred sources. The multiple and distant sources for food and timber, now based on hundreds of isotopic values from modern and archeological samples, confirm conventional wisdom about the geographic scope of the larger Chacoan system. The complexity of this procurement warns against simple generalizations based on just one species, a single class of botanical artifact, or a few isotopic values. ?? 2005 Elsevier Ltd. All rights reserved.

Quantifying multi-temporal urban development characteristics in Las Vegas from Landsat and ASTER data

USGS Publications Warehouse

Xian, G.; Crane, M.; McMahon, C.

2008-01-01

Urban development has expanded rapidly in Las Vegas, Nevada of the United States, over the last fifty years. A major environmental change associated with this urbanization trend is the transformation of the landscape from natural cover types to increasingly anthropogenic impervious surface. This research utilizes remote sensing data from both the Landsat and Terra-Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instruments in conjunction with digital orthophotography to estimate urban extent and its temporal changes by determining sub-pixel impervious surfaces. Percent impervious surface area has shown encouraging agreement with urban land extent and development density. Results indicate that total urban land-use increases approximately 110 percent from 1984 to 2002. Most of the increases are associated with medium-to high-density urban development. Places having significant increases in impervious surfaces are in the northwestern and southeastern parts of Las Vegas. Most high-density urban development, however, appears in central Las Vegas. Impervious surface conditions for 2002 measured from Landsat and ASTER satellite data are compared in terms of their accuracy.

Effectiveness of Traditional Chinese Acupuncture versus Sham Acupuncture: a Systematic Review.

PubMed

Carlos, Luís; Cruz, Lóris Aparecida Prado da; Leopoldo, Vanessa Cristina; Campos, Fabrício Ribeiro de; Almeida, Ana Maria de; Silveira, Renata Cristina de Campos Pereira

2016-08-15

to identify and synthesize the evidence from randomized clinical trials that tested the effectiveness of traditional Chinese acupuncture in relation to sham acupuncture for the treatment of hot flashes in menopausal women with breast cancer. systematic review guided by the recommendations of the Cochrane Collaboration. Citations were searched in the following databases: MEDLINE via PubMed, Web of Science, CENTRAL, CINAHL, and LILACS. A combination of the following keywords was used: breast neoplasm, acupuncture, acupuncture therapy, acupuncture points, placebos, sham treatment, hot flashes, hot flushes, menopause, climacteric, and vasomotor symptoms. a total of 272 studies were identified, five of which were selected and analyzed. Slight superiority of traditional acupuncture compared with sham acupuncture was observed; however, there were no strong statistical associations. the evidence gathered was not sufficient to affirm the effectiveness of traditional acupuncture compared with sham acupuncture. identificar e sintetizar as evidências oriundas de ensaios clínicos randomizados que testaram a efetividade da acupuntura tradicional chinesa em relação à sham acupuntura para o tratamento dos fogachos em mulheres com câncer de mama no climatério. revisão sistemática guiada pelas recomendações da Colaboração Cochrane. A busca foi realizada nas bases de dados: MEDLINE via PubMed, Web of Science, CENTRAL Cochrane, CINAHL e LILACS. Adotou-se a combinação dos descritores: breast neoplasm, acupuncture, acupuncture therapy, acupuncture points, placebos, sham treatment, hot flashes, hot flushes, menopause, climacteric, vasomotor symptoms. foram identificados 272 estudos, sendo 5 selecionados e analisados. Foi observada discreta superioridade da acupuntura tradicional em relação à sham, entretanto, sem fortes associações estatísticas. as evidências obtidas não foram suficientes para afirmar quanto à efetividade da acupuntura tradicional em relação à sham. Identificar y sintetizar la evidencia de un ensayo clínico aleatorizado que examinó la eficacia de la acupuntura tradicional en relación a la acupuntura sham para el tratamiento de sofocos en las mujeres menopáusicas con cáncer de mama. Revisión sistemática guiada por las recomendaciones de la Colaboración Cochrane. Las referencias bibliográficas se buscaron en las siguientes bases de datos: MEDLINE vía PubMed, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL y LILACS. Se utilizó una combinación de las siguientes palabras clave: breast neoplasm, acupuncture, acupuncture therapy, acupuncture points, placebos, sham treatment, hot flashes, hot flushes, menopause, climacteric, vasomotor symptoms. Se identificó un total de 272 estudios, cinco de los cuales fueron seleccionados y analizados. Se encontró una ligera superioridad de la acupuntura tradicional comparada con la acupuntura sham; sin embargo, no se encontraron asociaciones estadísticas fuertes. La evidencia obtenida no fue suficiente para confirmar la eficacia de la acupuntura tradicional comparada con la acupuntura sham.

Aplicación del Teorema de Nekhorochev para tiempos de estabilidad en Mecánica Celeste

NASA Astrophysics Data System (ADS)

Miloni, O.; Núñez, J.; Brunini, A.

En Mecánica Celeste, uno de los problemas centrales consiste en la determinación de los tiempos de estabilidad. El teorema de Nekhorochev proporciona un método para dicho estudio, para un sistema determinado por un hamiltoniano descripto en las variables acción-ángulo. El trabajo consiste en la acotación tanto del potencial perturbador y de la matriz hessiana del hamiltoniano integrable para determinar luego el tiempo de estabilidad de dicho sistema, donde por estabilidad se entiende la separación en norma infinito en el espacio de las acciones.

A Grounded theory study of the intention of nurses to leave the profession.

PubMed

Alilu, Leyla; Zamanzadeh, Vahid; Valizadeh, Leila; Habibzadeh, Hosein; Gillespie, Mark

2017-06-05

this study explores the process of the development of an intention to leave bedside nursing. the process was studied from the perspective of 21 nurses using the grounded theory method. Data were collected using semi-structured interviews and the constant comparative method of Corbin and Strauss was used for data analysis. according to the participants, the two main categories, "social image of nursing", and "culture and structure of the bedside", were the contextual factors that influence why nurses are leaving bedside care provision. Disappointment with a perceived lack of progress or improvement in the clinical experience formed primary psychosocial concerns for the participants. Competence and a process of self-control were steps taken by the participants. These, associated with interventional conditions produced the outcomes of the loss of professional commitment and desire to leave bedside nursing. "Failure to integrate personal expectations with organizational expectations: in search of escape" was the central category of the study that linked the categories together. the findings of this study provide useful information about the needs of nurses for overcoming the intention to leave bedside care. The identification of this process can help in recognizing emerging problems and providing solutions for them. este estudo explora o processo de desenvolvimento da intenção de deixar a enfermagem de cabeceira. o processo foi estudado desde a perspectiva de 21 enfermeiras utilizando o método da Grounded Theory (Teoria Fundamentada). Os dados foram coletados utilizando entrevistas semi-estruturadas e o método comparativo constante de Corbin e Strauss se utilizou para analisar os dados. segundo os participantes, duas categorias principais, "imagem social da enfermagem" e "cultura e estrutura de cabeceira", foram os fatores contextuais que influenciam as razões para que as enfermeiras estejam deixando o cuidado de cabeceira. A decepção com a percepção de falta de progresso ou melhora na experiência clínica cria preocupações psicossociais primárias para as participantes. A competência e o processo de autocontrole são passos dados pelas participantes. Isso associado a condições de intervenção foram os resultados da perda do compromisso profissional que as leva a deixar o cuidado de cabeceira. "O fracasso em integrar expectativas pessoais e expectativas da organização: em busca de uma saída" foi a categoria central do estudo que uniu as categorias. os achados deste estudo proporcionam informação útil sobre as necessidades das enfermeiras para superar as intenções de deixar o cuidado de cabeceira. A identificação deste processo pode ajudar a reconhecer os problemas emergentes e oferecer soluções para resolvê-los. este estudio explora el proceso de desarrollo de la intención de dejar la enfermería de cuidado de cabecera. el proceso fue estudiado desde la perspectiva de 21 enfermeras utilizando el método de la Grounded Theory (Teoría Fundamentada). Los datos se recogieron utilizando entrevistas semiestructuradas; para analizar los datos se utilizó el método comparativo constante de Corbin y Strauss. según los participantes dos categorías principales ("imagen social de la enfermería" y "cultura y estructura del cuidado de cabecera ") fueron los factores contextuales que influenciaron las razones para que las enfermeras deseasen dejar el cuidado de cabecera. La decepción con una percepción de falta de progreso o mejora en la experiencia clínica causó preocupaciones psicosociales primarias en las participantes. La competencia y el proceso de autocontrol fueron considerados por las participantes, y esto asociado a las condiciones de intervención resultaron en la pérdida del compromiso profesional que las lleva a dejar el cuidado de cabecera. La categoría central del estudio que unió las categorías encontradas fue: "Fracaso para integrar las expectativas personales con expectativas de la organización: en busca de una salida". los hallazgos de este estudio proporcionan información útil sobre las necesidades de las enfermeras para superar las intenciones de abandonar el cuidado de cabecera. La identificación de este proceso puede ayudar a reconocer los problemas emergentes y ofrecer soluciones para resolverlos.

PREVENCION DE VIH PARA MUJERES HISPANAS DE 50 AÑOS Y MÁS

PubMed Central

Villegas, N.; Cianelli, R.; Ferrer, L.; Kaelber, L.; Peragallo, N.; Yaya, Alexandra O.

2012-01-01

Introducción Las mujeres Hispanas de 50 años y más (MHC) son una minoría en Estados Unidos que está a elevado riesgo de adquirir VIH y son el grupo menos estudiado en lo que respecta a salud, características sociales y de comportamiento sexual. Objetivo Investigar los factores que incrementan el riesgo de VIH en las MHC con el propósito de desarrollar o adaptar una intervención apropiada para la “edad y la cultura "de este grupo de mujeres. Metodología Estudio descriptivo de corte transversal con una muestra de 50 MHC, sexualmente activas y que residían en Miami, Florida, Estados Unidos. Se utilizó un cuestionario estructurado administrado por entrevistadores entrenados y bilingües (inglés/español). Las participantes fueron reclutadas en diferentes lugares en el Sur de Florida. Para el análisis de los datos se utilizó estadística descriptiva, tanto medidas de tendencia central como medidas de dispersión. Resultados La edad promedio de las MHC fue de 55,7 ± 6 años (rango 50–76 años). Todas las MHC estaban en la menopausia. Prevención del VIH Las MHC reportaron niveles medios de conocimientos sobre VIH y comunicación con la pareja. En la muestra se reportó la presencia de síntomas depresivos, violencia en la pareja, actitudes negativas hacia las personas viviendo con VIH y baja percepción de riesgo de adquirir VIH. Las MHC mencionaron necesidades de aprendizaje en tópicos relacionados con prevención de VIH y cambios de la edad. Conclusión Las MHC están a riesgo de adquirir VIH y tienen necesidades especiales en términos de educación sobre prevención de VIH. PMID:25242862

Modeling of skeletal members using polyurethane foam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sena, J.M.F.; Weaver, R.W.

1983-11-01

At the request of the University of New Mexico's Maxwell Museum of Anthropology, members of the Plastic Section in the Process Development Division at SNLA undertook the special project of the Chaco Lady. The project consisted of polyurethane foam casting of a disinterred female skull considered to be approximately 1000 years old. Rubber latex molds, supplied by the UNM Anthropology Department, were used to produce the polymeric skull requested. The authors developed for the project a modified foaming process which will be used in future polyurethane castings of archaeological artifacts and contemporary skeletal members at the University.

Evaluacion de los recursos potenciales del petroleo y gas, en Centro y Suramerica [Evaluation of potential petroleum and gas resources in Central and South America

USGS Publications Warehouse

Schenk, C.S.

2001-01-01

El Servicio Geológico de los Estados Unidos (USGS, por sus siglas en inglés) completó recientemente un estudio evaluativo de recursos potenciales de petróleo y gas en 130 provincias de petróleo seleccionadas en diferentes partes del mundo (USGS, 2000). De estas 130 provincias, 23 se encuentran en Suramérica, Centroamérica, y la región del Caribe (fig. 1). El estudio comprendió desde las provincias de petróleo establecidas con un largo historial de producción, como la Cuenca de Maracaibo, hasta las provincias fronterizas de poca o ninguna producción, como la Cuenca de Guyana-Suriname. No todas las provincias con historial de producción o con potencial de producción fueron evaluadas en el Estudio Evaluativo USGS 2000. Al presente, el USGS está evaluando muchas de las provincias restantes de petróleo y gas, en Centro y Suramérica. En cada provincia hemos (1) definido geológicamente el total de los sistemas de petróleo, (2) definido las unidades evaluadas que forman parte de todos los sistemas de petróleo, y (3) evaluado el volumen potencial de petróleo y gas convencional en cada unidad evaluada. Definimos un total de 26 sistemas de petróleo y 55 unidades evaluadas en las 23 provincias

Reproductive Characteristics of Rodent Assemblages in Cultivated Regions of Central Argentina

DTIC Science & Technology

1992-01-01

tuvieron el mayor nfimero de BRONSON, F. H. 1989. Mammalian reproductive bi- ology. The University of Chicago Press, Chicago. embriones por prefiez. Las...Rosenkranz, andl~rdida de masa en animales adultos frente A. Moura Duarte, eds.). International Council forLaboratory Animal Science. Sao Paulo, Brazil, 331 a

Desarrollo curricular, conciencia ambiental y tecnologia para estudiantes de intermedia: Una investigacion en accion

NASA Astrophysics Data System (ADS)

Rodriguez Ramos, Teresita

Se llevó a cabo una investigación en acción con los propósitos de 1) documentar las relaciones de las tecnologías de la información y la comunicación en las clases de ciencias de escuela intermedia como elemento de apoyo cuando se aborda el tema ambiental y sus conceptos pertinentes, a partir de las observaciones de la investigadora, así como las entrevistas y diarios reflexivos de los estudiantes de una escuela intermedia en la zona metropolitana, y luego 2) diseñar una unidad instruccional sobre el tema ambiental que integre actividades tecnologías para el curso de ciencias de la escuela intermedia según el modelo PROCIC y las observaciones que hayan iniciado los estudiantes participantes. Finalmente, se plantearon las implicaciones educativas para el currículo del Programa de Ciencias al instrumentar este modelo de unidad mediante PROCIC, e integrado la tecnología y el tema ambiental. Los hallazgos se analizaron y se categorizaron de acuerdo con las preguntas de investigación. El hallazgo principal de la investigación aborda las cuatro relaciones centrales en las que se articula la utilización de las tecnologías y sus aplicaciones en la clase de ciencias. Estas cuatro relaciones que recogen la posición de los estudiantes son: 1) Perspectiva de los estudiantes hacia la tecnología. 2) Participación de los estudiantes en los aspectos docentes. 3) Aprendizaje estudiantil sobre el ambiente, y 4) Conciencia ambiental en relación con la vida diaria. Estas relaciones ponen de manifiesto,cómo se plantea en las implicaciones, la necesidad de más investigación en acción en la sala de clases, la importancia—como tema transversal—de la conciencia ambiental mediante la tecnología al construir conocimientos significativos dentro y fuera de la escuela, asó como, valorar la investigación y la dialogicidad en la sala de clases como actividades que obligan al reexamen de la práctica didáctica en su formas curriculares de objetivos, recursos, actividades, evaluación, entre otros. Estos planteamientos definen la unidad curricular que se propone en el cuatro capítulo.

Trade-offs between cattle production and bird conservation in an agricultural frontier of the Gran Chaco of Argentina.

PubMed

Mastrangelo, Matias E; Gavin, Michael C

2012-12-01

Intensification of food production in tropical landscapes in the absence of land-use planning can pose a major threat to biological diversity. Decisions on whether to spatially integrate or segregate lands for production and conservation depend in part on the functional relations between biological diversity and agricultural productivity. We measured diversity, density, and species composition of birds along a gradient of production intensification on an agricultural frontier of the Argentine Chaco, where dry tropical forests are cleared for cattle production. Bird species diversity in intact forests was higher than in any type of cattle-production system. Bird species richness decreased nonlinearly as cattle yield increased. Intermediate-intensity silvopastoral systems, those in which forest understory is selectively cleared to grow pastures of non-native plants beneath the tree canopy, produced 80% of the mean cattle yield obtained in pastures on cleared areas and were occupied by 70-90% of the number of bird species present in the nearest forest fragments. Densities of >50% of bird species were significantly lower in open pastures than in silvopastoral systems. Therefore, intermediate-intensity silvopastoral systems may have the greatest potential to sustain cattle yield and conserve a large percentage of bird species. However, compared with low-intensity production systems, in which forest structure and extent were intact, intermediate-intensity silvopastoral systems supported significantly fewer forest-restricted bird species and fewer frugivorous birds. These data suggest that the integration of production and conservation through intermediate-intensity silvopastoral systems combined with the protection of forest fragments may be required to maintain cattle yield, bird diversity, and conservation of forest-restricted species in this agricultural frontier. ©2012 Society for Conservation Biology.

Exploring the biological activity of condensed tannins and nutritional value of tree and shrub leaves from native species of the Argentinean Dry Chaco.

PubMed

García, Elisa M; Cherry, Nicole; Lambert, Barry D; Muir, James P; Nazareno, Mónica A; Arroquy, Jose I

2017-11-01

Tropical tree or shrub leaves are an important source of nutrients for ruminants and a potential source of biologically active compounds that may affect ruminal metabolism of nutrients. Therefore, eight woody species from the native flora of Argentinean Dry Chaco, rich in secondary compounds such as condensed tannins (CT), were assessed for their nutritional value, CT fractions and in vitro true digestibility of dry matter, as well as biological activity (BA). Differences among species were found in contents of total phenol, protein-precipitating phenols (PPP), bound proteins to PPP (BP) and BP/PPP (P < 0.0001). The BP/PPP ratio reveals differences among species in potential BA as indicated by protein precipitation. The major CT of each species were isolated and purified for use as a standard. Although Schinopsis balansae had the most (P ≤ 0.05) total CT (19.59% DM), Caesalpinia paraguariensis had greater (P ≤ 0.05) BA with the most PPP (530.21% dry matter). Larrea divaricata, at 0.97, followed by Acacia aroma, at 0.89, had CT with the highest (P ≤ 0.05) BP/PPP ratios, followed by Prosopis alba (0.59). There were differences in nutritive value and bioactivity among species. Those with the greatest CT were not necessarily those with the most BA. Caesalpinia paraguariensis, S. balansae and L. divaricata were the most promising species as native forage CT sources. Cercidiurm praecox (20.87% CP; 18.14% acid detergent fiber) and Prosopis nigra (19.00% CP; 27.96% acid detergent fiber) showed the best (P ≤ 0.05) nutritive values. According to their nutritive traits, these species might be complementary in grass-based ruminant diets. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Health evaluation of free-ranging and captive blue-fronted Amazon parrots (Amazona aestiva) in the Gran chaco, Bolivia.

PubMed

Deem, Sharon L; Noss, Andrew J; Cuéllar, Rosa Leny; Karesh, William B

2005-12-01

Bolivia has a total of 47 species of Psittacidae, seven of which have been identified in our study site, the semiarid Gran Chaco of the Isoso. One species, the blue-fronted parrot (Amazona aestiva), is frequently captured by local Isoseño Guaraní Indians for exploitation on the national and international market. These birds are often temporarily housed in small villages under unhygienic conditions with poultry and other domestic species. On occasion, these parrots escape back to the wild. Additionally, many of these birds are kept as pets or are used to lure wild. parrots within slingshot range for subsequent capture. In this study, we evaluated the health status, including the level of exposure to selected infectious agents, in the wild-caught captive birds and free-ranging birds. Physical examinations were performed, and blood was collected, from 54 live birds (20 captive and 34 free-ranging). Feces were collected from 15 birds (seven captive and eight free-ranging). Necropsies were also performed on four recently dead wild-caught birds. On serologic testing, no birds were found to have antibodies to avian influenza virus, Chlamydophila psittaci, infectious bronchitis virus, infectious bursal disease virus, infectious laryngotracheitis virus, Marek's disease virus, paramyxovirus-1, paramyxovirus-2, paramyxovirus-3, polyomavirus, eastern equine encephalitis virus, western equine encephalitis virus, or Venezuelan equine encephalitis virus. Positive antibody titers were found for psittacine herpesvirus (8/44, 18.2%), Aspergillus spp. (3/51, 5.9%), and Salmonella pullorum (33/49, 67.3%). All three of the birds that tested antibody positive for Aspergillus spp. were captive, whereas six of the eight and 15 of the 33 birds that tested positive for psittacine herpesvirus and S. pullorum, respectively, were wild.

Traditions of the Sun, One Model for Expanding Audience Access

NASA Astrophysics Data System (ADS)

Hawkins, I.; Paglierani, R.

2006-12-01

The Internet is a powerful tool with which to expand audience access, bringing students, teachers and the public to places and resources they might not otherwise visit or make use of. We will present Traditions of the Sun, an experiential Web site that invites exploration of the world's ancient observatories with special emphasis on Chaco Culture National Historic Park in the Four Corners region of the US and several sites in the Yucatan Peninsula in Mexico. Traditions of the Sun includes resources in English and Spanish along with a unique trilingual on-line book, "Traditions of the Sun, A Photographic Journal," containing explanatory text in Yucatec Maya as well. Traditions of the Sun offers rich opportunities for virtual visits to ancient sites used for solar observing while learning about current NASA research on the Sun and indigenous solar practices within a larger historical and cultural context. The site contains hundreds of photographs, historic images and rich multimedia to help tell the story of the Sun-Earth Connection. Visitors to the site can zoom in on the great Mayan cities of Chichen Itza, Uxmal, Dzibilchaltun, and Mayapan to learn about Mayan astronomy, history, culture, and science. They can also visit Chaco Canyon to watch sunrise over Pueblo Bonito on the summer solstice, take a virtual reality tour of the great kiva at Casa Rinconada or see panoramic vistas from Fajada Butte, an area which, for preservation purposes, is restricted to the public. Traditions of the Sun provides one model of how exploration and discovery can come to life for both formal and informal audiences via the Internet. Traditions of the Sun is a collaborative project between NASA's Sun-Earth Connection Education Forum, the National Park Service, Instituto National de Antropologia e Historia, Universidad Nacional Autonoma de Mexico, and Ideum.

Geology, energy- and mineral-resources assessment of the Socorro Area, New Mexico. Report No. 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krason, J.; Wodzicki, A.; Cruver, S.K.

1987-03-01

Geology, energy, and mineral (GEM) resource assessments were conducted in three wilderness study areas (WSAs) in Socorro County, in central New Mexico; Sierra Las Cansa, Veranito, and Stallion. The study assesses the potential for locatable, leasable, and salable energy and mineral resources within each WSA.

National Maps - NOAA's National Weather Service

Science.gov Websites

information, select area of interest and click on the image below. National Weather Outlook Northeast Michigan Boston and Surrounding Areas Western New York - Buffalo Northern Vermont and New York Southern Maine California and Northwestern Arizona - Las Vegas South Central California Los Angeles Area San Francisco Area

Subsurface Connections and Magma Mixing as revealed by Olivine- and Pyroxene-Hosted Melt Inclusions from Cerro Negro Volcano and the Las Pilas-El Hoyo Complex, Nicaragua.

NASA Astrophysics Data System (ADS)

Venugopal, S.; Moune, S.; Williams-Jones, G.

2015-12-01

Cerro Negro, the youngest volcano in the Central American Volcanic Belt, is a polygenetic cinder cone with relatively frequent explosive basaltic eruptions. Las Pilas, on the other hand, is a much larger and older complex with milder and less frequent eruptions. Based on historical data, these two closely spaced volcanoes have shown concurrent eruptive behavior, suggesting a subsurface connection. To further investigate this link, melt inclusions, which are blebs of melt trapped in growing crystals, were the obvious choice for optimal comparison of sources and determination of pre-eruptive volatile contents and magmatic conditions. Olivine-hosted inclusions were chosen for both volcanoes and pyroxene-hosted inclusions were also sampled from Las Pilas to represent the evolved melt. Major, volatile and trace elements reveal a distinct geochemical continuum with Cerro Negro defining the primitive end member and Las Pilas representing the evolved end member. Volatile contents are high for Cerro Negro (up to 1260 ppm CO2, 4.27 wt% H2O and 1700 ppm S) suggesting that volatile exsolution is likely the trigger for Cerro Negro's explosive eruptions. Las Pilas volatile contents are lower but consistent with degassing and evolutionary trends shown by major oxides. Trace element contents are rather unique and suggest Cerro Negro magmas fractionally crystallize while Las Pilas magmas are the products of mixing. Magmatic conditions were estimated with major and volatile contents: at least 2.4 kbar and 1170 °C for Cerro Negro melts and 1.3 kbar and 1130 °C for Las Pilas melts with an overall oxygen fugacity at the NNO buffer. In combination with available literature data, this study suggests an interconnected subsurface plumbing system and thus Cerro Negro should be considered as the newest vent within the Las Pilas-El Hoyo Complex.

Archaeoastronomy in the New World

NASA Astrophysics Data System (ADS)

Aveni, Anthony F.

2010-01-01

List of contributors; 1. Introduction A. F. Aveni; 2. Archaeoastronomy in the Maya region A. F. Aveni; 3. Historical archaeoastronomy: the Hopi example S. C. McCluskey; 4. The Sidereal Lunar Calendar of the Incas R. T. Zuidema; 5. Astronomical norms in Mesoamerican rituals and time-reckoning G. Brotherston; 6. Astronomical knowledge and its uses at Bonampak, Mexico F. G. Lounsbury; 7. Lunar markings of Fajada Butte, Chaco Canyon A. Sofaer, R. M. Sinclair and L. E. Doggett; 8. The Skidi Pawnee earth lodge as an observatory V. D. Chamberlain; 9. Caldendrical petroglyphs of Northern Mexico W. B. Murray; 10. Casa Rinconada, twelfth-century Anasazi Kiva R. A. Williamson.

America - Las Americas. Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama.

ERIC Educational Resources Information Center

Toro, Leonor; And Others

These publications were written for teachers to use with migrant children in elementary grades to highlight individual differences between the countries that make up the Americas by providing historical, geographical, and cultural information about them on a quarterly basis. The three issues presented here focus on nations of Central America with…

Las Mujeres: Conversations from a Hispanic Community. Women's Lives/Women's Work Project.

ERIC Educational Resources Information Center

Elsasser, Nan; And Others

The life stories of 21 Hispanic women of New Mexico spanning roughly four generations, are recorded in this book. Four sections ("But I Remember,""The Soul of the Home,""Little by Little," and "A Lighted Fire") develop these central themes: the shift from a rural to an urban environment; the struggle to…

Stratigraphic framework of upper Paleozoic rocks, southeastern Sangre de Cristo Mountains, New Mexico

USGS Publications Warehouse

Baltz, E.H.; Myers, D.A.

1999-01-01

The Sangre de Cristo Mountains of south-central Colorado and north-central New Mexico are the physiographic expression of a southerly trending Cenozoic structural uplift that plunges gently south to die out in the Great Plains south of Santa Fe and Las Vegas, New Mexico. The uplift is bounded on the west by Neogene downfaulted and downwarped basins of the Rio Grande depression and, on the east, by broad Laramide basins that have sharply folded western limbs. The uplift was modified in Neogene time by local igneous-intrusive doming and normal faulting related to the Rio Grande rift.

El rol de Ia colaboracion y el Modelo de Aprendizaje Basado en Proyectos (ABPr) mediante el lente de la Teoria de Actividad (CHAT): un estudio de caso con estudiantes de 9no grado

NASA Astrophysics Data System (ADS)

Delgado, Isabel C.

Los modelos de eensenanza y aprendizaje constructivistas conceptualizan el aprendizaje como un proceso activo. El modelo de Aprendizaje Basado en Proyectos (ABPr) se distingue por una serie de componentes, entre los cuales se destaca el aspecto colaborativo y cooperativo como un reto al momento de su implantacion. Son pocas las investigaciones que se concentran en este aspecto del modelo. En este estudio, se analizaron las diversas interacciones que surgen durante la implantacion de una unidad curricular sobre el tema de Geologia de Puerto Rico, la cual se diseno con el modelo ABPr cuyo enfoque es orientacion a proyectos. Particularmente, se examinaron las interacciones sociales que surgen entre los pares y entre pares y docente durante el proceso de planificacion y desarrollo de los productos finales, al igual que las interacciones entre los estudiantes y el material didactico en estas etapas del modelo. La investigacion es de tipo cualitativo e incorpora como diseno el estudio de caso. Las diversas interacciones constituyen la unidad de analisis. En el estudio participaron 19 estudiantes de 9no grado, a quienes se organizaron en 5 grupos colaborativos por temas de interes (Pangea, Placas tectonicas, Volcanes, Tsunamis y Terremotos). Las tecnicas que se utilizaron para recopilar los datos fueron: observaciones participativas, grupos focales y analisis de documentos (cuadernos reflexivos y respuestas de los estudiantes a la pregunta central del proyecto). Para el analisis de los datos se aplico la teoria de actividad (CHAT) que concentra la unidad de analisis en la actividad humana en un contexto particular. Los resultados del estudio senalan que las interacciones entre pares, entre pares y docente, asi como entre estudiantes y material didactico son fundamentales en el proceso de aprendizaje. Una mayor interaccion entre pares durante las etapas de planificar y desarrollar los productos finales de la unidad, promueve una mejor comprension de los conceptos de la unidad, segun evidencia los productos finales del ABPr. La interaccion con el docente es muy importante para mediar los conflictos y desacuerdos que surgen como parte de las interacciones entre pares. Por lo tanto, el uso de diversas estrategias de andamiaje por parte del docente durante las reuniones de los grupos colaborativos es esencial para el exito del modelo ABPr.

A Second Las17 Monomeric Actin-Binding Motif Functions in Arp2/3-Dependent Actin Polymerization During Endocytosis

PubMed Central

Feliciano, Daniel; Tolsma, Thomas O.; Farrell, Kristen B.; Aradi, Al; Di Pietro, Santiago M.

2018-01-01

During clathrin-mediated endocytosis (CME), actin assembly provides force to drive vesicle internalization. Members of the Wiskott–Aldrich syndrome protein (WASP) family play a fundamental role stimulating actin assembly. WASP family proteins contain a WH2 motif that binds globular actin (G-actin) and a central-acidic motif that binds the Arp2/3 complex, thus promoting the formation of branched actin filaments. Yeast WASP (Las17) is the strongest of five factors promoting Arp2/3-dependent actin polymerization during CME. It was suggested that this strong activity may be caused by a putative second G-actin-binding motif in Las17. Here, we describe the in vitro and in vivo characterization of such Las17 G-actin-binding motif (LGM) and its dependence on a group of conserved arginine residues. Using the yeast two-hybrid system, GST-pulldown, fluorescence polarization and pyrene-actin polymerization assays, we show that LGM binds G-actin and is necessary for normal Arp2/3-mediated actin polymerization in vitro. Live-cell fluorescence microscopy experiments demonstrate that LGM is required for normal dynamics of actin polymerization during CME. Further, LGM is necessary for normal dynamics of endocytic machinery components that are recruited at early, intermediate and late stages of endocytosis, as well as for optimal endocytosis of native CME cargo. Both in vitro and in vivo experiments show that LGM has relatively lower potency compared to the previously known Las17 G-actin-binding motif, WH2. These results establish a second G-actin-binding motif in Las17 and advance our knowledge on the mechanism of actin assembly during CME. PMID:25615019

From Word to World: Reflections on the Ezra Jack Keats Award.

ERIC Educational Resources Information Center

Herrera, Juan Felipe

2000-01-01

Discusses the author's Ezra Jack Keats Award for "Calling the Doves/El Canto de las Palomas" (1995), a bilingual picture book based on his childhood in the farm working camps of Central California. Concludes that writers must stay true to the deep sources of multicultural experience, for positive change, and for the magical pictures and poems. (SG)

Origin of Aymaras from Bolivia and their relationship with other Amerindians according to HLA genes.

PubMed

Arnaiz-Villena, A; Siles, N; Moscoso, J; Zamora, J; Serrano-Vela, J I; Gomez-Casado, E; Castro, M J; Martinez-Laso, J

2005-04-01

Aymara Amerindians from the Titicaca Lake Andean highlands are studied for HLA-A, HLA-B, HLA-DRB1 and HLA-DQB1 gene frequencies. Genetic distances, neighbour-joining and correspondence analyses are performed by using other Amerindian and worldwide populations (15384 chromosomes are studied). The HLA genetic profile of Aymaras is different from neighbouring and language-related Quechuas (Incas). Both Quechuas and Aymaras seem to present an HLA-DRB1*0901 high frequency, which is present in a very low frequency or absent in Mesoamericans (Mazatecans, Mayans) and most studied Amerindians. Moreover, it is observed a closer relatedness of Aymaras with Amerindians from the Amazon Basin and Chaco lowlands, compared to Quechuans.

Global Albedo

NASA Technical Reports Server (NTRS)

2002-01-01

Once home to the powerful Inca Empire, the spectacular vistas and canyons of the South American Andes are now a favorite to mountain bikers, climbers and other tourists looking for an adventure. This true color image of the Central Andes and surrounding landscape was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. The dark green area to the right of the brown mountains are the Gran Chaco planes, which consist mostly of alluvial fans and wetlands. To the west is the Pacific Ocean. In the upper half of this image, the Andes are formed by two distinct mountain ranges that appear as darker reddish-brown bands running northwest to southeast. Between the two ranges, shown in a lighter brown, sits the Altiplano plateau, which spans southern Peru and northern Bolivia. The plateau sits at 3660 meters (12,000 feet) and is covered in mazelike canyons, marshlands and lakes. The largest of the lakes-Lake Titticaca-can be seen as the dark blue patch in southern Peru. The two mountain ranges supporting the plateau eventually come together along the border of Argentina and Chile to form one continuous range. The Andes have been forming over the past 170 million years as the Nazca Plate lying under the Pacific Ocean has forced its way under the South American Plate and pushed up its western edge. The subduction of one plate under the other has given rise to a number of volcanoes that dot the western edge of the mountain range. Earthquakes are also very common in this region. Image by NASA GSFC, based on data from the MODIS science team.

Biogeography of the Lizard Genus Tropidurus Wied-Neuwied, 1825 (Squamata: Tropiduridae): Distribution, Endemism, and Area Relationships in South America

PubMed Central

de Carvalho, André Luiz Gomes; de Britto, Marcelo Ribeiro; Fernandes, Daniel Silva

2013-01-01

Based on comprehensive distributional records of the 23 species currently assigned to the lizard genus Tropidurus, we investigated patterns of endemism and area relationships in South America. Two biogeographic methods were applied, Parsimony Analysis of Endemicity (PAE) and Brooks Parsimony Analysis (BPA). Two areas of endemism were detected by PAE: the first within the domains of the semiarid Brazilian Caatinga, which includes seven endemic species, and the second in the region of the Serranía de Huanchaca, eastern Bolivia, in which three endemic species are present. The area cladograms recovered a close relationship between the Atlantic Forest and areas of the South American open corridor. The results revealed a close relationship among the provinces Caatinga (Cerrado, Parana Forest (Pantanal+Chaco)). The uplift of the Brazilian Central Plateau in the Late Pliocene-Early Pleistocene (4-2 Myr BP) has been interpreted as a major event responsible for isolation and differentiation of biotas along these areas. However, we emphasize that without the establishment of a temporal framework concerning the diversification history of Tropidurus it is premature to correlate cladogenetic events with specific time periods or putative vicariant scenarios. The limiting factors hampering the understanding of the biogeographic history of this genus include (1) the absence of temporal references in relation to the diversification of distinct clades within Tropidurus; (2) the lack of an appropriate taxonomic resolution of the species complexes currently represented by widely distributed forms; and (3) the need for a comprehensive phylogenetic hypothesis. We suggest that these three important aspects should be prioritized in future investigations. PMID:23527261

Growth stratal records of instantaneous and progressive limb rotation in the Precordillera thrust belt and Bermejo basin, Argentina

NASA Astrophysics Data System (ADS)

Zapata, TomáS. R.; Allmendinger, Richard W.

1996-10-01

Analysis of synorogenic deposits preserved near the thrust front zone of the Precordillera fold and thrust belt and in the Bermejo foreland basin in central Argentina documents the evolution of deformation during the last 5 Myr as well as the thrust system kinematics. Seismic lines across the area display examples of progressive and instantaneous limb rotations. The easternmost thrust plate of the Central Precordillera, the Niquivil thrust, experienced episodic motion in two main stages: a first thrust movement as a fault-propagation fold and a second movement as a high-angle anticlinal breakthrough fault after a period of quiescence. Growth strata deposited in the La Pareja intermontane basin and the Las Salinas and Bermejo anticline recorded continuous growth of Eastern Precordilleran structures beginning at ˜2.7 Ma, with uplift rates of ˜0.3 mm/yr for the Niquivil anticline, 1.08 mm/yr for the Las Salinas anticline, and between ˜0.6 and 0.38 mm/yr during the last ˜2 Myr for the Bermejo anticline. Once the Eastern Precordillera began to grow, the propagation of the Niquivil thrust stopped, restricting the deformation to the young Vallecito out-of sequence thrust. The complex geometry of growth strata deposited on the back limb of the Las Salinas anticline can be explained by using a model of a two-step fault propagation fold with constant layer thickness. The Bermejo anticline of the Eastern Precordillera is formed by the simultaneous propagation of a shallow fault, responsible for the fold shape, and a deep fault that produced vertical uplift. A growth triangle that documents instantaneous forelimb rotation for a fault-propagation fold is recorded for the first time in a published seismic line.

Department of Defense HIV/AIDS Prevention Program (DHAPP): 2006 Annual Report

DTIC Science & Technology

2007-01-01

The Comité Central de Prevención y Control del VIH /SIDA de las Fuerzas Armadas y Po- licía Nacional del Perú (COPRECOS) is a gov- B A C K G R O U N D...military populations; STIs; oppor- tunistic infections; combined therapy for HIV and tuber- culosis co-infections; VIH , HTLV-1, HCV, HBV co- infections

Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass.

PubMed

Quiroga, R Emiliano; Golluscio, Rodolfo A; Blanco, Lisandro J; Fernández, Roberto J

2010-10-01

It has been proposed that aridity and grazing are convergent selective forces: each one selects for traits conferring resistance to both. However, this conceptual model has not yet been experimentally validated. The aim of this work was to experimentally evaluate the effect of aridity and grazing, as selective forces, on drought and grazing resistance of populations of Trichloris crinita, a native perennial forage grass of the Argentinean Arid Chaco region. We collected seeds in sites with four different combinations of aridity and grazing history (semiarid/ subhumid x heavily grazed/lightly grazed), established them in pots in a common garden, and subjected the resulting plants to different combinations of drought and defoliation. Our results agreed with the convergence model. Aridity has selected T. crinita genotypes that respond better to drought and defoliation in terms of sexual reproduction and leaf growth, and that can evade grazing due to a lower shoot: root ratio and a higher resource allocation to reserves (starch) in stem bases. Similarly, grazing has selected genotypes that respond better to drought and defoliation in terms of sexual reproduction and that can evade grazing due to a lower digestibility of leaf blades. These results allow us to extend concepts of previous models in plant adaptation to herbivory to models on plant adaptation to drought. The only variable in which we obtained a result opposite to predictions was plant height, as plants from semiarid sites were taller (and with more erect tillers) than plants from subhumid sites; we hypothesize that this result might have been a consequence of the selection exerted by the high solar radiation and soil temperatures of semiarid sites. In addition, our work allows for the prediction of the effects of dry or wet growing seasons on the performance of T. crinita plants. Our results suggest that we can rely on dry environments for selecting grazing-resistant genotypes and on high grazing pressure history environments for selecting drought-resistant ones.

Analysis of Population Substructure in Two Sympatric Populations of Gran Chaco, Argentina

PubMed Central

Sevini, Federica; Yao, Daniele Yang; Lomartire, Laura; Barbieri, Annalaura; Vianello, Dario; Ferri, Gianmarco; Moretti, Edgardo; Dasso, Maria Cristina; Garagnani, Paolo; Pettener, Davide; Franceschi, Claudio; Luiselli, Donata; Franceschi, Zelda Alice

2013-01-01

Sub-population structure and intricate kinship dynamics might introduce biases in molecular anthropology studies and could invalidate the efforts to understand diseases in highly admixed populations. In order to clarify the previously observed distribution pattern and morbidity of Chagas disease in Gran Chaco, Argentina, we studied two populations (Wichí and Criollos) recruited following an innovative bio-cultural model considering their complex cultural interactions. By reconstructing the genetic background and the structure of these two culturally different populations, the pattern of admixture, the correspondence between genealogical and genetic relationships, this integrated perspective had the power to validate data and to link the gap usually relying on a singular discipline. Although Wichí and Criollos share the same area, these sympatric populations are differentiated from the genetic point of view as revealed by Non Recombinant Y Chromosome genotyping resulting in significantly high Fst values and in a lower genetic variability in the Wichí population. Surprisingly, the Amerindian and the European components emerged with comparable amounts (20%) among Criollos and Wichí respectively. The detailed analysis of mitochondrial DNA showed that the two populations have as much as 87% of private haplotypes. Moreover, from the maternal perspective, despite a common Amerindian origin, an Andean and an Amazonian component emerged in Criollos and in Wichí respectively. Our approach allowed us to highlight that quite frequently there is a discrepancy between self-reported and genetic kinship. Indeed, if self-reported identity and kinship are usually utilized in population genetics as a reliable proxy for genetic identity and parental relationship, in our model populations appear to be the result not only and not simply of the genetic background but also of complex cultural determinants. This integrated approach paves the way to a rigorous reconstruction of demographic and cultural history as well as of bioancestry and propensity to diseases of Wichí and Criollos. PMID:23717528

Near Real Time Change-Point detection in Optical and Thermal Infrared Time Series Using Bayesian Inference over the Dry Chaco Forest

NASA Astrophysics Data System (ADS)

Barraza Bernadas, V.; Grings, F.; Roitberg, E.; Perna, P.; Karszenbaum, H.

2017-12-01

The Dry Chaco region (DCF) has the highest absolute deforestation rates of all Argentinian forests. The most recent report indicates a current deforestation rate of 200,000 Ha year-1. In order to better monitor this process, DCF was chosen to implement an early warning program for illegal deforestation. Although the area is intensively studied using medium resolution imagery (Landsat), the products obtained have a yearly pace and therefore unsuited for an early warning program. In this paper, we evaluated the performance of an online Bayesian change-point detection algorithm for MODIS Enhanced Vegetation Index (EVI) and Land Surface Temperature (LST) datasets. The goal was to to monitor the abrupt changes in vegetation dynamics associated with deforestation events. We tested this model by simulating 16-day EVI and 8-day LST time series with varying amounts of seasonality, noise, length of the time series and by adding abrupt changes with different magnitudes. This model was then tested on real satellite time series available through the Google Earth Engine, over a pilot area in DCF, where deforestation was common in the 2004-2016 period. A comparison with yearly benchmark products based on Landsat images is also presented (REDAF dataset). The results shows the advantages of using an automatic model to detect a changepoint in the time series than using only visual inspection techniques. Simulating time series with varying amounts of seasonality and noise, and by adding abrupt changes at different times and magnitudes, revealed that this model is robust against noise, and is not influenced by changes in amplitude of the seasonal component. Furthermore, the results compared favorably with REDAF dataset (near 65% of agreement). These results show the potential to combine LST and EVI to identify deforestation events. This work is being developed within the frame of the national Forest Law for the protection and sustainable development of Native Forest in Argentina in agreement with international legislation (REDD+).

House Reinfestation With Triatoma infestans (Hemiptera: Reduviidae) After Community-Wide Spraying With Insecticides in the Argentine Chaco: A Multifactorial Process.

PubMed

Provecho, Yael M; Gaspe, M Sol; Fernández, M Del Pilar; Gürtler, Ricardo E

2017-05-01

We investigated the dynamics and underlying causes of house (re)infestation with Triatoma infestans (Klug 1834) after a community-wide residual spraying with pyrethroids in a well-defined rural section of Pampa del Indio municipality (northeastern Argentina) over a 4-yr period. House infestation was assessed by timed manual searches, during insecticide applications, and by opportunistic householders' bug collections. All reinfested houses were selectively re-sprayed with insecticides. The resident population comprised Qom (66.6%) and Creole (33.4%) households, whose sociodemographic profiles differed substantially. The prevalence of house infestation dropped, less than expected, from 20.5% at baseline to 5.0% at 14 months postspraying (MPS), and then fluctuated between 0.8 and 4.2% over 21-51 MPS. Postspraying house infestation was positively and highly significantly associated with prespraying infestation. Most of the foci detected over 14-21 MPS were considered persistent (residual), some of which were moderately resistant to pyrethroids and were suppressed with malathion. Infestation patterns over 27-51 MPS suggested bug invasion from internal or external foci, but the sources of most findings were unaccounted for. Local spatial analysis identified two hotspots of postspraying house infestation. Using multimodel inference with model averaging, we corroborated that baseline domestic infestation was closely related to refuge availability, housing quality, and occurrence of peridomestic infestation. The diminished effectiveness of single pyrethroid treatments, partly attributable to moderate resistance compounded with rather insensitive vector detection methods and poor housing conditions, contributed to vector persistence. Improved control strategies combined with broad social participation are needed for the sustainable elimination of vector-borne human Chagas disease from the Gran Chaco. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Serologic evidence of canine parvovirus in domestic dogs, wild carnivores, and marsupials in the Argentinean Chaco.

PubMed

Orozco, María Marcela; Miccio, Luciano; Enriquez, Gustavo Fabián; Iribarren, Fabián Eduardo; Gürtler, Ricardo Esteban

2014-09-01

The transmission of pathogens between domestic dogs and generalist wildlife species may be modified by environmental degradation, biodiversity losses, host densities, and increased contact rates in remnant forest patches. A serologic survey of canine parvovirus (CPV) in rural domestic dogs and wild mammals was conducted in two neighboring rural areas (disturbed and protected) from Pampa del Indio, northeastern Argentina, between 2008 and 2011. A total of 174 domestic dogs and 26 wild mammals-4 crab-eating foxes (Cerdocyon thous), 3 crab-eating raccoons (Procyon cancrivorus), 17 white-eared opossums (Didelphis albiventris), and 2 gray four-eyed opossums (Philander opossum)-were examined for antibodies to CPV using a hemagglutination inhibition assay. Domestic dogs were numerous and their movements unrestricted. The main function of dogs differed significantly between areas, with more dogs used for herding or hunting around the protected area. The seroprevalence of antibodies to CPV in dogs from both areas was very high (93.9-94.6%) and increased steeply with age. Nearly all carnivores and marsupials showed high exposure to CPV. Although a higher exposure to CPV was expected in wild mammals from disturbed areas as a result of enhanced contact between dogs and wildlife, no significant differences were found between areas. To the authors' knowledge, this study is the first to document exposure to CPV of free-ranging Pr. cancrivorus, D. albiventris, and Ph. opossum, and include a detailed demographic study of the domestic dog populations living in the area. This study highlights that dogs and wildlife have potential opportunities for contact and shows that the edges of the protected area may be as suitable as other fragmented areas for the transmission of CPV. Rural domestic dogs may pose serious threats to the health and conservation of wild carnivores in both disturbed and protected areas, especially in the Gran Chaco, where habitat fragmentation is severely increasing.

20 years of mass balances on the Piloto glacier, Las Cuevas river basin, Mendoza, Argentina

NASA Astrophysics Data System (ADS)

Leiva, J. C.; Cabrera, G. A.; Lenzano, L. E.

2007-10-01

Climatic changes of the 20th century have altered the water cycle in the Andean basins of central Argentina. The most visible change is seen in the mountain glaciers, with loss of part of their mass due to decreasing thickness and a substantial recession in the last 100 years. This paper briefly describes the results of glacier mass balance research since 1979 in the Piloto Glacier at the Cajón del Rubio, in the headwaters of Las Cuevas River, presenting new results for the period 1997-2003. Very large interannual variability of net annual specific balance is evident, due largely to variations in winter snow accumulation, with a maximum net annual value of + 151 cm w.e. and a minimum value of - 230 cm w.e. Wet El Niño years are normally associated with positive net annual balances, while dry La Niña years generally result in negative balances. Within the 24-year period, 67% of the years show negative net annual specific balances, with a cumulative mass balance loss of - 10.50 m water equivalent (w.e.). Except for exceptions normally related to El Niño events, a general decreasing trend of winter snow accumulation is evident in the record, particularly after 1992, which has a strong effect in the overall negative mass balance values. The glacier contribution to Las Cuevas River runoff is analysed based on the Punta de Vacas River gauge station for a hypothetical year without snow precipitation (YWSP), when the snowmelt component is zero. Extremely dry years similar to a YWSP have occurred in 1968-1969, 1969-1970 and 1996-1997. The Punta de Vacas gauge station is located 62 km downstream from Piloto Glacier, and the basin contains 3.0% of uncovered glacier ice and 3.7% of debris-covered ice. The total glacier contribution to Las Cuevas River discharge is calculated as 82 ± 8% during extremely dry years. If glacier wastage continues at the present trend as observed during the last 2 decades, it will severely affect the water resources in the arid central Andes of Argentina.

Seasonal variation of temporal niche in wild owl monkeys (Aotus azarai azarai) of the Argentinean Chaco: a matter of masking?

PubMed

Erkert, Hans G; Fernandez-Duque, Eduardo; Rotundo, Marcelo; Scheideler, Angelika

2012-07-01

Among the more than 40 genera of anthropoid primates (monkeys, apes, and humans), only the South American owl monkeys, genus Aotus, are nocturnal. However, the southernmostly distributed species, Aotus azarai azarai, of the Gran Chaco may show considerable amounts of its 24-h activity during bright daylight. Due to seasonal changes in the duration of photophase and climatic parameters in their subtropical habitat, the timing and pattern of their daily activity are expected to show significant seasonal variation. By quantitative long-term activity recordings with Actiwatch AW4 accelerometer data logger devices of 10 wild owl monkeys inhabiting a gallery forest in Formosa, Argentina, the authors analyzed the seasonal variation in the temporal niche and activity pattern resulting from entrainment and masking of the circadian activity rhythm by seasonally and diurnally varying environmental factors. The owl monkeys always displayed a distinct bimodal activity pattern, with prominent activity bouts and peaks during dusk and dawn. Their activity rhythm showed distinct lunar and seasonal variations in the timing and daily pattern. During the summer, the monkeys showed predominantly crepuscular/nocturnal behavior, and a crepuscular/cathemeral activity pattern with similar diurnal and nocturnal activity levels during the cold winter months. The peak times of the evening and morning activity bouts were more closely related to the times of sunset and sunrise, respectively, than activity-onset and -offset. Obviously, they were better circadian markers for the phase position of the entrained activity rhythm than activity-onset and -offset, which were subject to more masking effects of environmental and/or internal factors. Total daily activity was lowest during the two coldest lunar months, and almost twice as high during the warmest months. Nighttime (21:00-06:00 h) and daytime (09:00-18:00 h) activity varied significantly across the year, but in an opposite manner. Highest nighttime activity occurred in summer and maximal daytime activity during the cold winter months. Dusk and dawn activity, which together accounted for 43% of the total daily activity, barely changed. The monkeys tended to terminate their nightly activity period earlier on warm and rainy days, whereas the daily amount of activity showed no significant correlation either with temperature or precipitation. These data are consistent with the dual-oscillator hypothesis of circadian regulation. They suggest the seasonal variations of the timing and pattern of daily activity in wild owl monkeys of the Argentinean Chaco result from a specific interplay of light entrainment of circadian rhythmicity and strong masking effects of various endogenous and environmental factors. Since the phase position of the monkeys' evening and morning activity peaks did not vary considerably over the year, the seasonal change from a crepuscular/nocturnal activity pattern in summer to a more crepuscular/cathemeral one in winter does not depend on a corresponding phase shift of the entrained circadian rhythm, but mainly on masking effects. Thermoregulatory and energetic demands and constraints seem to play a crucial role.

Volcanic geomorphosites and geotourism in Las Cañadas del Teide National Park, Tenerife, Canary Islands, Spain

NASA Astrophysics Data System (ADS)

Dóniz-Paéz, Javier; Becerra-Ramírez, Rafael; González-Cárdenas, Elena; Rodriguez, Fátima

2017-04-01

Geomorphosites and geoturism studies are increasing for the high scientific, societal, cultural, and aesthetic values of the relief. Volcanic areas are exciting targets for such studies for their geodiversity. The aim of these study is an inventory of volcanic geomorphosites and its relationship to geotourism. Las Cañadas del Teide National Park (LCTNP) is a volcanic complex area located in the central part of Tenerife island (Canary Islands, Spain). This area is a volcanic paradise rich in spectacular landforms: stratovolcanoes, calderas, cinder cones, craters, pahoehoe, aa, block and balls lavas, gullies, etc. The national park is registered in the world heritage list (UNESCO) in 2007 as a natural site. The LCTNP receives more than 2,5 million tourists per year and it has 21 main pahts and 14 secondary ones. For the selection of the geomophosites the LCTNP was divided into four geomorphological units (Teide-Pico Viejo stratovolcanoes, Las Cañadas Caldera wall, the bottom of Las Cañadas and the basaltic volcanic field) and each one of them is selected the most representative geomorphosites by its geodiversity, because of its geomorphological heritage, its landscapes and its tourist potential with the paths. All selected geomorphosites are within areas where public use is allowed in the park. The inventory classifies the 23 geomorphosites in two main categories: (a) direct volcanic with 17 geomorphosites (stratovolcanoes, domes, cinder cones, pahoehoe, aa and bloc lava flows, etc.) and (b) eroded volcanic landforms with 6 (wall of Las Cañadas caldera, talusees, foodplains, etc.). The Teide-Pico Viejo unit is which has more geomorphosites with 8 and the Las Cañadas wall unit possessing less with 5. The assessment evaluates the scientific, cultural/historical, and use values and helps to define priorities in site management. These geomorphosites demonstrate the volcanic history and processes of the LCTNP.

Evaluation of Modeling Schemes to Estimate Evapotranspiration and Root Zone Soil Water Content over Vineyard using a Scintillometer and Remotely Sensed Surface Energy Balance

NASA Astrophysics Data System (ADS)

Geli, H. M. E.; Gonzalez-Piqueras, J.; Isidro, C., Sr.

2016-12-01

Actual crop evapotranspiration (ETa) and root zone soil water content (SMC) are key operational variable to monitor water consumption and water stress condition for improve vineyard grapes productivity and quality. This analysis, evaluates the estimation of ETa and SMC based on two modeling approaches. The first approach is a hybrid model that couples a thermal-based two source energy balance (TSEB) model (Norman et al. 1995) and water balance model to estimate the two variable (Geli 2012). The second approach is based on Large Aperture Scintillometer (LAS)-based estimates of sensible heat flux. The LAS-based estimates of sensible heat fluxes were used to calculate latent heat flux as the residual of surface energy balance equation on hourly basis which was converted to daily ETa. The calculated ETa from the scintillometer was then couple with the water balance approach to provide updated ETa_LAS and SMC_LAS. Both estimates of ETa and SMC based on LAS (i.e. ETa_LAS and SMC_LAS) and TSEB (ETa_TSEB and SMC_TSEB) were compared with ground-based observation from eddy covariance and soil water content measurements at multiple depths. The study site is an irrigated vineyard located in Central Spain Primary with heterogeneous surface conditions in term of irrigation practices and the ground based observation over the vineyard were collected during the summer of 2007. Preliminary results of the inter-comparison of the two approaches suggests relatively good between both modeling approaches and ground-based observations with RMSE lower than 1.2 mm/day for ETa and lower than 20% for SMC. References Norman, J. M., Kustas, W. P., & Humes, K. S. (1995). A two-source approach for estimating soil and vegetation energy fluxes in observations of directional radiometric surface temperature. Agricultural and Forest Meteorology, 77, 263293. Geli, Hatim M. E. (2012). Modeling spatial surface energy fluxes of agricultural and riparian vegetation using remote sensing, Ph. D. dissertation, Department of Civil and Environmental Engineering, Utah State University.

Recovery of Durvillaea antarctica (Durvilleales) inside and outside Las Cruces Marine Reserve, Chile.

PubMed

Castilla, J C; Campo, M A; Bustamante, R H

2007-07-01

We present the results for over two decades of monitoring on intertidal food-gatherers and the population of the low rocky shore dweller kelp Durvillaea antarctica, a short-distance disperser, inside and outside the no-take marine reserve, Estacion Costera de Investigaciones Marinas (ECIM), at Las Cruces, central Chile. It was hypothesized that protection of an initially extremely depleted population would recover by recolonizing first the no-take area and then adjacent non-protected (exploited) areas. We found that recovery of D. antarctica occurred slowly inside ECIM, with increase in density and biomass, of up to three orders of magnitude as compared to an adjacent non-protected area, which showed approximately 2-yr delay. These results suggest that the kelp population inside ECIM was likely regulated via intraspecific competition, which did not occur outside. Results showed no evidence for juvenile vs. adult density dependence other than a weak relationship for the central area of ECIM. These findings also suggest that the population recovery and cross-boundary seeding subsides affected the population dynamics. Understanding these dynamics may enhance management and conservation policies. Our work highlights the critical value of baseline and long-term comparative studies in marine no-take protected and non-protected areas for understanding how population processes respond to human and conservation practices.

An analysis of urban thermal characteristics and associated land cover in Tampa Bay and Las Vegas using Landsat satellite data

USGS Publications Warehouse

Xian, George; Crane, Mike

2006-01-01

Remote sensing data from both Landsat 5 and Landsat 7 systems were utilized to assess urban area thermal characteristics in Tampa Bay watershed of west-central Florida, and the Las Vegas valley of southern Nevada. To quantitatively determine urban land use extents and development densities, sub-pixel impervious surface areas were mapped for both areas. The urban–rural boundaries and urban development densities were defined by selecting certain imperviousness threshold values and Landsat thermal bands were used to investigate urban surface thermal patterns. Analysis results suggest that urban surface thermal characteristics and patterns can be identified through qualitatively based urban land use and development density data. Results show the urban area of the Tampa Bay watershed has a daytime heating effect (heat-source), whereas the urban surface in Las Vegas has a daytime cooling effect (heat-sink). These thermal effects strongly correlated with urban development densities where higher percent imperviousness is usually associated with higher surface temperature. Using vegetation canopy coverage information, the spatial and temporal distributions of urban impervious surface and associated thermal characteristics are demonstrated to be very useful sources in quantifying urban land use, development intensity, and urban thermal patterns.

Stratigraphic Units in Las Vegas Valley, Nevada

NASA Astrophysics Data System (ADS)

Donovan, D.

2013-12-01

Using 25 well logs, 15 of which also had accompanying geophysical and aquifer test data were used to describe and establish three alloformations including the Tule Spring and Paradise Valley Alloformations and four aquiformations, the most well defined being, the Las Vegas Springs Aquiformation, in the west central part of the bolson (Donovan, 1996), primarily in Township 20 South, Range 60 East, Mount Diablo Baseline and Meridian (MDBLM), with the stratotypes designated in T20S, R61E S31 MDBLM (36° 9'59.89"N 115°11'26.34"W). The allostratigraphic units were developed using the recommendations in the North American Code of Stratigraphic Nomenclature (NACSN, 1983 and 2005). The hydrostratigraphic units were developed following the recommendations of Seaber (1992). The units constitute the bulk of the upper 500 meter section. Twenty additional wells in the same geographic area, drilled and completed between 1995 and 2005 with detailed geologic and hydrologic information provided confirmation of these units. The proposed stratigraphic units are not part of either, and are located between, the two previously named and non-contiguous formations in the bolson (the Miocene Muddy Creek Formation and the late Pleistocene Las Vegas Formation) (Longwell et al 1965). Las Vegas Valley contains a metropolitan area of approximately two million people. The deeper part of the alluvial basin below 300 ft below ground surface is of interest for supply and storage. The shallower part is of interest for water quality and the interaction between the ground water system and engineered structures.

Que hay de nuevo acerca de la inmersion? Un Breve Recorrido por sus Fundamentos y por las Investigaciones Actuales (What's New in Immersion? A Brief Overview of Its Bases and Present-Day Research).

ERIC Educational Resources Information Center

Sierra, Josu

This discussion briefly surveys the development of the immersion method of second language teaching, outlining the central program strategies and characteristics using Curtain's and Pesola's descriptions. An overview of recent research focuses on error correction and feedback studies as an example of pedagogical-methodological evolution in this…

Environmental and geochemical record of human-induced changes in C storage during the last millennium in a temperate wetland (Las Tablas de Daimiel National Park, central Spain)

USGS Publications Warehouse

Dominguez-Castro, F.; Santisteban, J.I.; Mediavilla, R.; Dean, W.E.; Lopez-Pamo, E.; Gil-Garcia, M. J.; Ruiz-Zapata, M. B.

2006-01-01

Las Tablas de Daimiel National Park has experienced many hydrological and ecological modifications through out its history, both of natural as well as anthropogenic origin, which have affected its carbon storage capacity and carbon fluxes. The study of those variations has been carried out by the analysis of its sedimentary record (geochemistry and pollen) and historical data. The natural changes have a wider variation range than the anthropogenic ones, show repetitive patterns and the system reacts readjusting the equilibrium among its components. Anthropogenic effects depend on the direct or indirect impact on the wetlands of change and its intensity. In addition, the anthropogenic impacts have the capacity of breaking the natural balance of the ecosystem and the internal interactions. ?? 2006 The Authors Journal compilation ?? 2006 Blackwell Munksgaard.

Estudio polarimétrico de NGC 104 (47 Tucanae)

NASA Astrophysics Data System (ADS)

Forte, J. C.; Bassino, L. P.; Vega, E. I.; Cellone, S.; Pellizza, L.; Méndez, M.

Se presentan observaciones polarimétricas en el Visual y sin filtro para 72 estrellas, 14 zonas de referencia y el núcleo del cúmulo globular NGC 104. Las medidas, hechas en el CASLEO con el nuevo polarimétro CASPROF, muestran un comportamiento complejo que incluye: a) dos componentes de polarización a lo largo de la visual; b) signos de envolturas polvorientas en 8 de 10 estrellas variables de largo período pertenecientes al cúmulo c) media docena de estrellas con alta polarización residual (P> 0.20 %) originada probablemente en scattering. Estas estrellas se encuentran próximas a una estructura extendida, coincidente con la región central del cúmulo, detectada en observaciones IRAS. Las observaciones son consistentes con la presencia de pequeñas cantidades de polvo originada en procesos de pérdida de masa.

Espectro de radiación derivado de un modelo de colapso protoestelar

NASA Astrophysics Data System (ADS)

Coca, S.; Rohrmann, R.

El exceso de emisión infrarroja en objetos protoestelares es atribuido usualmente a un disco de material en torno al cuerpo central. A pesar del avance alcanzado en la elaboración de modelos, aún existen dificultades para explicar la ley de temperatura del disco necesaria para reproducir las luminosidades y perfiles de energía observados. Nuestra propuesta consiste en determinar la distribución espectral de la radiación derivada de un particular modelo de colapso protoestelar, y estudiar la evolución del espectro desde estadíos tempranos de la contracción gravitatoria. Este plan es orientado a evaluar las propiedades del modelo (distribuciones de masa y temperatura del material circunestelar) por comparación con datos observacionales, a fin de inferir de ello los posibles ajustes requeridos en la teoría actualmente empleada.

Arsenic concentration in water and bovine milk in Cordoba, Argentina. Preliminary results.

PubMed

Pérez-Carrera, Alejo; Fernández-Cirelli, Alicia

2005-02-01

The Chaco Pampean Plain of central Argentina constitutes one of the largest regions of high arsenic (As) groundwaters known, covering around 1 x 10(6) km2 (Smedley & Kinniburg, 2002; Farías et al. 2004). The high-As groundwaters are from Quaternary deposits of loess (mainly silt) with intermixed rhyolitic or dacitic volcanic ash (Nicolli et al. 1989, Smedley et al. 1998,2002). Early in the last century an endemic disease due to contamination of drinking water with arsenic was recognised. This disease is called HACRE (Hidroarsenicismo Crónico Regional Endémico, Chronic Endemic Regional Hydroarsenism) and is connected with a particular type of skin cancer (Astolfi et al. 1981). One of the most affected region is the province of Cordoba, where Nicolli et al. (1989) reported As concentrations that exceed the maximun level permitted for drinking water of 50 microg/l for 82% of the groundwater samples (n=60) of a study area comprising approximately 10000 km2. The southeast of Cordoba is an important milk production zone in Argentina, where dairy product consumption is up to 192 equivalent milk l/inhabitant/year. As a secretion of the mammary gland, milk can carry numerous xenobiotic substances, which constitute a technological risk factor for dairy products and above all for the health of the consumer (Licata et al. 2004). Nevertheless no studies on the incidence of high-As livestock drinking water in livestock health and its transfer to milk have been performed in Argentina. The aim of the present study was the determination of arsenic content in livestock drinking water and milk from dairy farms located in an area of high-As groundwaters, to analyse the relation between As uptake through water and its transfer to milk.

Crop expansion and conservation priorities in tropical countries.

PubMed

Phalan, Ben; Bertzky, Monika; Butchart, Stuart H M; Donald, Paul F; Scharlemann, Jörn P W; Stattersfield, Alison J; Balmford, Andrew

2013-01-01

Expansion of cropland in tropical countries is one of the principal causes of biodiversity loss, and threatens to undermine progress towards meeting the Aichi Biodiversity Targets. To understand this threat better, we analysed data on crop distribution and expansion in 128 tropical countries, assessed changes in area of the main crops and mapped overlaps between conservation priorities and cultivation potential. Rice was the single crop grown over the largest area, especially in tropical forest biomes. Cropland in tropical countries expanded by c. 48,000 km(2) per year from 1999-2008. The countries which added the greatest area of new cropland were Nigeria, Indonesia, Ethiopia, Sudan and Brazil. Soybeans and maize are the crops which expanded most in absolute area. Other crops with large increases included rice, sorghum, oil palm, beans, sugar cane, cow peas, wheat and cassava. Areas of high cultivation potential-while bearing in mind that political and socio-economic conditions can be as influential as biophysical ones-may be vulnerable to conversion in the future. These include some priority areas for biodiversity conservation in tropical countries (e.g., Frontier Forests and High Biodiversity Wilderness Areas), which have previously been identified as having 'low vulnerability', in particular in central Africa and northern Australia. There are also many other smaller areas which are important for biodiversity and which have high cultivation potential (e.g., in the fringes of the Amazon basin, in the Paraguayan Chaco, and in the savanna woodlands of the Sahel and East Africa). We highlight the urgent need for more effective sustainability standards and policies addressing both production and consumption of tropical commodities, including robust land-use planning in agricultural frontiers, establishment of new protected areas or REDD+ projects in places agriculture has not yet reached, and reduction or elimination of incentives for land-demanding bioenergy feedstocks.

Puerto Rico, humedales [Puerto Rico, wetlands

USGS Publications Warehouse

Adams, D. Briane; Hefner, John M.; Dopazo, Teresa

1999-01-01

La isla de Puerto Rico, localizada al noreste del Mar Caribe y sus islas principales, Vieques, Culebra e Isla de Mona, poseen humedales en abundancia . El clima subtropical, la lluvia abundante y las complejas formas topográficas y geológicas de estas islas dan origen a los humedales, que varían desde los raros e inusuales bosques cubiertos por nubes en las tierras altas, hasta los extensos manglares, yerbas marinas y arrecifes de coral a lo largo de las costas Norte y Sur. Sin embargo, los humedales en Puerto Rico han disminuido en los últimos siglos como resultado del aumento en el desarrollo agrícola, poblacional y turístico. Algunos tipos de humedales como los bosques de palo de pollo (Pterocarpus officinalis) se han reducido a sólo unos pocos remanentes (figura 1).Biológicamente hablando, los humedales de las islas están entre las áreas más productivas. Los humedales asociados con el bosque pluvial en las tierras altas del interior de Puerto Rico contienen varias plantas raras y especies de animales que no se encuentran en otras partes de la Isla. El agua de escorrentía proveniente de los humedales en las partes altas de la Isla proveen una fuente de agua que utilizan varias ciudades para abasto público. Los humedales costeros como los mangles, los colchones de yerbas marinas y los arrecifes de coral proveen áreas para la reproducción y crianza de varios peces, crustáceos y otras especies en la cadena alimenticia (López y otros, 1988). De esta manera, los humedales costeros contribuyen a la productividad biológica de las aguas llanas del mar alrededor de las islas . Los humedales también estabilizan las costas atrapando y reteniendo sedimentos no consolidados y amortiguan la acción de las olas y de las tormentas que tienen el potencial de causar daños en la zona.El valor de los humedales de Puerto Rico para la vida silvestre está muy bien documentado . Por ejemplo, las salinas de Cabo Rojo, en la costa suroeste, proveen áreas para el descanso y la alimentación de cientos de aves migratorias en ruta entre Norte y Suramérica. Antes del drenaje de los humedales costeros para propósitos agrícolas, pantanos de agua dulce como los de la Laguna Cartagena, Laguna Guánica y Ciénaga El Anegado proveían hábitat a más de 1 00 especies de aves residentes y migratorias . Los humedales de las tierras altas del área central son el último refugio de la cotorra puertorriqueña, una especie en peligro de extinción. Aún los humedales del área metropolitana de San Juan (Laguna La Torrecilla, Torrecilla Baja, Laguna de Piñones hasta Punta Vacía Talega) proveen un hábitat excelente para la vida silvestre, mantienen criaderos de peces de alto valor económico y proveen recreación y oportunidades educativas a la población urbana.Treintiocho especies de vertebrados, moluscos y crustáceos, y 46 especies de aves, algunos raros o en peligro de extinción como la mariquita, el alcatraz, el pato dominicano, el pato silbón y la paloma cabeciblanca han sido observados en el área . También las playas asociadas con estos humedales urbanos proveen sitios de anidaje para las tortugas carey de concha y tinglar, ambas en peligro de extinción (Del Llano y otros, 1986).

Evidence-based measures to prevent central line-associated bloodstream infections: a systematic review.

PubMed

Perin, Daniele Cristina; Erdmann, Alacoque Lorenzini; Higashi, Giovana Dorneles Callegaro; Sasso, Grace Teresinha Marcon Dal

2016-09-01

to identify evidence-based care to prevent CLABSI among adult patients hospitalized in ICUs. systematic review conducted in the following databases: PubMed, Scopus, Cinahl, Web of Science, Lilacs, Bdenf and Cochrane Studies addressing care and maintenance of central venous catheters, published from January 2011 to July 2014 were searched. The 34 studies identified were organized in an instrument and assessed by using the classification provided by the Joanna Briggs Institute. the studies presented care bundles including elements such as hand hygiene and maximal barrier precautions; multidimensional programs and strategies such as impregnated catheters and bandages and the involvement of facilities in and commitment of staff to preventing infections. care bundles coupled with education and the commitment of both staff and institutions is a strategy that can contribute to decreased rates of central line-associated bloodstream infections among adult patients hospitalized in intensive care units. identificar evidências de cuidados para prevenção de infecção de corrente sanguínea relacionada a cateter venoso central em pacientes adultos em Unidades de Terapia Intensiva. revisão Sistemática realizada por meio de busca nas bases de dados Pubmed, Scopus, Cinahl, Web of Science, Lilacs, Bdenf e Cochrane. Foram buscadas pesquisas com cuidados com a cateterização e manutenção do cateter venoso central, publicados de janeiro de 2011 a julho de 2014. Os 34 estudos incluídos foram organizados em um instrumento e avaliados por meio da classificação do The Joanna Briggs Institute. os estudos apresentaram bundles de cuidados com elementos como a higiene das mãos e precauções máximas de barreira; programas multidimensionais e estratégias como cateteres e curativos impregnados e o envolvimento da instituição e engajamento da equipe nos esforços para prevenção de infecção. os cuidados no formato de bundles aliados com a educação e engajamento da equipe e da instituição são estratégias que poderão contribuir para a redução das taxas de infecção de corrente sanguínea relacionada a cateter venoso central em pacientes adultos em unidades de terapia intensiva. identificar evidencias de cuidados para prevención de infección de la corriente sanguínea relacionada al catéter venoso central, en pacientes adultos en Unidades de Terapia Intensiva. revisión sistemática realizada por medio de búsqueda en las bases de datos Pubmed, Scopus, Cinahl, Web of Science, Lilacs, Bdenf y Cochrane. Fueron buscadas investigaciones de cuidados con la cateterización y manutención del catéter venoso central, publicados de enero de 2011 a julio de 2014. Los 34 estudios incluidos fueron organizados en un instrumento y evaluados por medio de la clasificación del The Joanna Briggs Institute. los estudios presentaron bundles de cuidados con elementos como: higiene de las manos y precauciones máximas de barrera; programas multidimensionales y estrategias como catéteres y curativos impregnados y, participación de la institución y compromiso del equipo en los esfuerzos para prevención de la infección. los cuidados en el formato de bundles aliados con la educación y compromiso del equipo y de la institución, son estrategias que podrán contribuir para la reducción de las tasas de infección de la corriente sanguínea relacionadas al catéter venoso central, en pacientes adultos en unidades de terapia intensiva.

Plant diversity of the Pantanal wetland.

PubMed

Pott, A; Oliveira, A K M; Damasceno-Junior, G A; Silva, J S V

2011-04-01

This is a review of current studies in diversity of the flora and main vegetation types in the Brazilian Pantanal. The flora of this wetland, nearly 2,000 species, constitutes a pool of elements of wide distribution and from more or less adjacent phytogeographic provinces, such as Cerrado, dry seasonal forests, Chaco, Amazonia and Atlantic Forest. The most numerous group includes wide-distribution species, mainly herbs, while the second contingent comes from the Cerrado. Endemic plants are rare, numbering only seven. The vegetation of the sedimentary floodplain is a mosaic of aquatics, floodable grasslands, riparian forests, savannas (cerrados), cerrado woodlands, dry forests, and a large area of mono-dominant savannas, and pioneer woodlands. The main vegetation types are briefly described with their characteristic species, and their estimated areas are given according to the latest mapping.

South America as seen from the Apollo 7 spacecraft

NASA Image and Video Library

1968-10-17

AS07-07-1826 (17 Oct. 1968) --- This view of South America was photographed from the Apollo 7 spacecraft during its 81st revolution of Earth from an altitude of 120 nautical miles. The port city of Antofagasta, Chile, is located in the half-moon shaped bay in the lower left portion of the picture. Beyond the coast is the Andean peak of Llullaillaco Volcano which rises 22,000 feet above sea level. At left center is the Chuquicamata copper mines located near Coloma. At the center of the photo, behind the large salt lake and atop a 19,000 foot high volcano, the countries of Bolivia, Argentina, and Chile meet at a common point. Below the clouds in the upper portion of the photo are the Great Plains known as the Gran Chaco.

Satellite passive microwave remote sensing for estimating diurnal variation of leaf water content, as a proxy of evapotranspiration, in the Dry Chaco Forest, Argentina

NASA Astrophysics Data System (ADS)

Barraza Bernadas, V.; Grings, F.; Ferrazzoli, P.; Carbajo, A.; Fernandez, R.; Karszenbaum, H.

2012-12-01

Evapotranspiration (ET) is a key component of water cycle, which is strongly linked with environmental condition and vegetation functioning. Since it is very difficult to robustly estimate it from remote sensing data at regional scale it is usually inferred from other proxies using water balance. This work describes a procedure to estimate ET in a dry forest by monitoring diurnal variation of leaf water content (LWC), using multitemporal passive microwave remote sensing observations. Hourly observations provide the opportunity to monitor repetitive diurnal variations of passive microwave observations, which can only be accounted by changes in LWC (which is itself related to water vapor that enters to the atmosphere from land surface). To this end, we calculated the vegetation frequency index (FI) as FI= 2*(TBKa-TBX)/ ((TBKa +TBX)), where TBKa and TBX indicate brightness temperatures at 37 and 10.6 GHz respectively. There is both theoretical and experimental evidence that link this index to microwave to LWC. The index was computed for vertical polarization, because it presents higher correlation with vegetation state. At diurnal temporal scale, changes in LWC are commonly very small. Nevertheless, it was previously shown that passive remote sensing data (FI computed using Ku and Ka bands) acquired at different hours can be used to estimate the seasonal changes in ET. In this work, we present a procedure based on the hourly changes of FI, which are interpreted as changes in LWC. In order to present a quantitative estimation, the discrete forest model described in (Ferrazzoli and Guerriero, 1996) has been used to simulate the variations of FI with LWC. To illustrate the procedure, AMSR-E and WINDSAT data from 2007-2009 at X and Ka bands were used, and up to four observations per day at four different local times (2.30 am, 7.00 am, 2.30 pm and 7.00 pm) were analyzed. The region addressed is the area of the Dry Chaco forest located in Bermejo River Basin in Argentina (22-27°S, and 58-66°W).This area is characterized for being an open dry forest (20% of tree crown cover), with mean annual temperatures between 20 and 22 °C, mean summer temperatures between 24 and 27 °C and minimal annual rainfall (500 mm). The annual behavior of diurnal LWC shows a range increase in summer and a decrease in winter, being correlated with vegetation annual growing season (foliation/defoliation). For summertime, our results show a decrease of FI values from 7.00 am to 2.30 pm and an increase between 2.30 pm to 7.00 pm. According to the interaction model, these observed changes of FI corresponded to an increase in LWC from ~0.4 g/g to 0.5 g/g in six hours (7.00 am - 2.30 pm) and then a similar decrease for the 2.30 pm to 7.00 pm period. We hypothesize that this daily variations (an increase of LWC during the sunny hours) could be related to more water being available at the leaves, to cope with evaporation needs in order to achieve positive diurnal water balance during the hot diurnal hours. This could be a specific adaptation to high temperature and drought environmental conditions, like the ones present in Chaco. Ferrazzoli P., Guerriero L.,(1996)"Passive microwave remote sensing of forests: a model investigation", IEEE Transactions on Geoscience and Remote Sensing, vol.34, n. 2, pp.433-443.

Earth Observations taken by the Expedition 15 Crew

NASA Image and Video Library

2007-05-13

ISS015-E-07928 (13 May 2007) --- Isla San Lorenzo and Isla Las Animas are featured in this image photographed by an Expedition 15 crewmember on the International Space Station. Located in the northern Gulf of California, Isla (island) San Lorenzo and Isla Las Animas -- part of the Midriff Islands -- record geologic processes involved in the creation of the Baja California peninsula over several hundred million years, according to scientists. A geologist walking along the 17-kilometer long central ridge of Isla San Lorenzo from the southeastern to the northwestern end would first encounter Cretaceous granitic rock in the southeastern third of the island (light tan, center left). The central third of the island is comprised mainly of older Paleozoic metamorphic rocks (brown, center; directly above "Isla San Lorenzo"). Together, these very old rocks form the crystalline "basement" of the island. The northwestern third of Isla San Lorenzo, and much of adjacent Isla Las Animas, is composed of much more recent volcanic and marine sedimentary rocks (yellow-brown to light brown, center right). According to scientists, these rocks were formed by volcanoes and fissure eruptions in and around basins in the growing Gulf of California between 5-8 million years ago. The islands themselves were formed as a result of uplift of crustal blocks along the southeastward-trending San Andreas Fault. This image illustrates the largely pristine nature of these islands. The islands are located in the rain shadow of mountains on the Baja Peninsula to the west, and arid conditions prevail through much of the year. The scarcity of water has limited human presence on the islands, and allowed flora and fauna unique to each island (known as endemic species) to flourish -- particularly reptiles. The islands are also home to colonies of seabirds and seals, both of which take advantage of deep productive waters adjacent to the eastern Baja coast. Shallow waters and high levels of nutrients can also lead to blooms of green phytoplankton; two such blooms can be seen along the coastline of Isla Las Animas (center right, in north and west-facing embayments). Surface water patterns around the islands -- enhanced by sunlight reflectance off the water surface -- are due to wind- and current-induced roughness (silver-gray regions). Regions of dark blue water are indicative of calm surface conditions, or the presence of oils and surfactants that decrease surface tension.

La Implementacion de la Tecnologia en el Salon de Clases: Una guia para los que toman decisiones en las escuelas rurales (Putting Technology into the Classroom: A Guide for Rural Decision Makers).

ERIC Educational Resources Information Center

Boethel, Martha; Dimock, K. Victoria; Hatch, Lin; Adams, Sharon, Ed.; Heath, Marilyn, Ed.

This guide is intended for superintendents and central office staff in small, rural school districts who are considering ways of using technology in the classroom. It provides information about why technology is worth the trouble and what it can accomplish, lays out the basic issues and tasks involved in integrating technology into classroom…

Earthquakes: Risk, Monitoring, Notification, and Research

DTIC Science & Technology

2008-06-19

Washington, Oregon, and Hawaii . The Rocky Mountain region, a portion of the central United States known as the New Madrid Seismic Zone, and portions...California, Washington, Oregon, and Alaska and Hawaii . Alaska is the most earthquake-prone state, experiencing a magnitude 7 earthquake1 almost every...Oakland, CA $349 23 Las Vegas, NV $28 4 San Francisco, CA $346 24 Anchorage, AK $25 5 San Jose, CA $243 25 Boston, MA $23 6 Orange, CA $214 26 Hilo , HI $20

Concepciones Alternativas de "Fotosintesis" en estudiantes Universitarios del curso basico de Biologia y posibles correcciones con el Modelo Educativo MODEF

NASA Astrophysics Data System (ADS)

De Jesus Roman, Sandra

Concepciones Alternativas de Fotosíntesis en estudiantes Universitariosdel curso básico de Biología y posibles correcciones con el Modelo Educativo MODEF El modelo educativo para la enseñanza de Fotosíntesis (MODEF) se implantó para trabajar el problema de las concepciones alternativas (CA) en un curso de Biología General. Se evaluaron los resultados en cuanto al logro del aprendizaje significativo. La pregunta central de la investigación fue: ¿Cómo aporta el modelo educativo en la didáctica y comprensión del tema de fotosíntesis? Se efectuó una investigación acción con una fase cuantitativa y una cualitativa. Para la fase cuantitativa se elaboró una prueba para determinar las concepciones alternativas, se validó y se sometió a los estudiantes que participaron en el estudio antes y después de ofrecer la unidad de metabolismo celular. Los participantes eran estudiantes de primer año de la Universidad de Puerto Rico en Bayamón (UPRB). Se llevó a cabo un análisis de consistencia interna de la prueba mediante el método Alfa de Cronbach. Se analizaron las contestaciones a cada pregunta mediante la prueba de Ji cuadrado de contingencia, se efectuó la prueba de t y el coeficiente r de Pearson. La fase cualitativa incluyó la observación participativa de la investigadora- profesora, las reflexiones de los estudiantes y la información de las entrevistas semi-estructuradas que se realizaron a tres estudiantes del curso. El análisis se llevó a cabo mediante el Modelo de Wolcott. Se trabajaron diez CA de las cuales siete fueron corregidas mediante el Modelo MODEF. Las actividades más importantes para el proceso de aprendizaje incluyeron el trabajo de investigación o búsqueda de información para hacer una presentación digital, la elaboración de tablas, los mapas de conceptos, el uso de visuales o videos y las analogías para explicar conceptos o procesos. En conclusión: se recomienda el uso del Modelo MODEF para la discusión del tema de Fotosíntesis a base de los resultados cuantitativos y cualitativos de esta investigación. El Comité Institucional para la Protección de los Seres Humanos en la Investigación (CIPSHI) autorizó el estudio.

Inverse modeling using PS-InSAR for improved calibration of hydraulic parameters and prediction of future subsidence for Las Vegas Valley, USA

NASA Astrophysics Data System (ADS)

Burbey, T. J.; Zhang, M.

2015-11-01

Las Vegas Valley has had a long history of surface deformation due to groundwater pumping that began in the early 20th century. After nearly 80 years of pumping, PS-InSAR interferograms have revealed detailed and complex spatial patterns of subsidence in the Las Vegas Valley area that do not coincide with major pumping regions. High spatial and temporal resolution subsidence observations from InSAR and hydraulic head data were used to inversely calibrate transmissivities (T), elastic and inelastic skeletal storage coefficients (Ske and Skv) of the developed-zone aquifer and conductance (CR) of the basin-fill faults for the entire Las Vegas basin. The results indicate that the subsidence observations from PS-InSAR are extremely beneficial for accurately quantifying hydraulic parameters, and the model calibration results are far more accurate than when using only water-levels as observations, and just a few random subsidence observations. Future predictions of land subsidence to year 2030 were made on the basis of existing pumping patterns and rates. Simulation results suggests that subsidence will continue in northwest subsidence bowl area, which is expected to undergo an additional 11.3 cm of subsidence. Even mitigation measures that include artificial recharge and reduced pumping do not significantly reduce the compaction in the northwest subsidence bowl. This is due to the slow draining of thick confining units in the region. However, a small amount of uplift of 0.4 cm is expected in the North and Central bowl areas over the next 20 years.

Traditional cattle vs. introduced deer management in Chaco Serrano woodlands (Argentina): Analysis of environmental sustainability at increasing densities.

PubMed

Charro, José Luis; López-Sánchez, Aida; Perea, Ramón

2018-01-15

Wild ungulate populations have increased and expanded considerably in many regions, including austral woodlands and forests where deer (Cervus elaphus) have been introduced as an alternative management to traditional cattle grazing. In this study, we compared traditional cattle with introduced deer management at increasing deer densities in the "Chaco Serrano" woodlands of Argentina to assess their ecological sustainability. We used three ecological indicators (abundance of tree regeneration, woody plant diversity and browsing damage) as proxies for environmental sustainability in woody systems. Our results indicate that traditional cattle management, at stocking rates of ∼10 ind km -2 , was the most ecologically sustainable management since it allowed greater tree regeneration abundance, higher richness of woody species and lower browsing damage. Importantly, cattle management and deer management at low densities (10 ind km -2 ) showed no significant differences in species richness and abundance of seedlings, although deer caused greater browsing damage on saplings and juveniles. However, management regimes involving high deer densities (∼35 deer km 2 ) was highly unsustainable in comparison to low (∼10 deer km -2 ) and medium (∼20 deer km -2 ) densities, with 40% probability of unsustainable browsing as opposed to less than 5% probability at low and medium densities. In addition, high deer densities caused a strong reduction in tree regeneration, with a 19-30% reduction in the abundance of seedlings and young trees when compared to low deer densities. These results showed that the effect of increasing deer densities on woody plant conservation was not linear, with high deer densities causing a disproportional deleterious effect on tree regeneration and sustainable browsing. Our results suggest that traditional management at low densities or the use of introduced ungulates (deer breeding areas) at low-medium densities (<20 deer km -2 ) are compatible with woody vegetation conservation. However, further research is needed on plant palatability, animal habitat use (spatial heterogeneity) and species turnover and extinction (comparison to areas of low-null historical browsing) to better estimate environmental sustainability of Neotropical ungulate-dominated woodlands. Copyright © 2017 Elsevier Ltd. All rights reserved.

Surface Currents. East Central Indian Ocean Including the East Indian Archipelago (Indonesia)

DTIC Science & Technology

1977-08-01

AKAX EXPLORATION INC. FOREIGN HYDROGRAPHER/R, A. N. DEPT. TRANSPORTATIO&AUSTRLIA RKAD hi TRUC"TONSREPORT DOCUMENTATION PAGE aRo E COMPLITMG PORN 20...thirties... DO Io+.u 1473 boI o O ovc ois LCZ S/4 1 32-a 0145 01 S C UR IT Y CL A SSIFIC AT IO N O f H IS P AG E (34.44 4 8 0 0R C S A OSE[CURIlTY cLAS

Symposium on Engineering With Nuclear Explosives January 14-16, 1970, Las Vegas, Nevada. Volume 1

DTIC Science & Technology

1970-05-01

from the earth and moon mining systems near exhaustion and says: The recent discovery of coal (black, fossilized plant remains ) in a number of places...fuel for our central power stations can further reduce the amount of pollutants that are put into the atmosphere by fossil fuels. Technology can help...degree, what still remains to be accomplished, so I will not attempt to go into detail here. However, I would like to take a few minutes to summarize

Síntesis del estado del conocimiento del ciclo de carbono en ecosistemas boscosos de los Estados Unidos

Treesearch

Michael G. Ryan; Mark E. Harmon; Richard A. Birdsey; Christian P. Giardina; Linda S. Heath; Richard A. Houghton; Robert B. Jackson; Duncan C. McKinley; James F. Morrison; Brian C. Murray; Diane E. Pataki; Kenneth E. Skog

2010-01-01

Los bosques juegan un papel central en el ciclo de carbono de los Estados Unidos y global. El secuestro de carbono de los bosques de los Estados Unidos, a través de su crecimiento y la cosecha de productos madereros, compensa en la actualidad entre un 12 y un 19% de las emisiones de carbono asociadas al uso de combustible fósil de dicho país. El ciclo natural de un...

Conference on Operator Theory, Wavelet Theory and Control Theory

DTIC Science & Technology

1993-09-30

UNCC and TAMU Wavelet collocation method for nonlinear time evolution - PDE’s 4 : 00 - 4: 20 A in Li, the University of Nevada - Las Vagas Wav slet...operator-valued functions. Inspired by Robinson’s characterization, we havc found a similar mninimum deliy characterization for the central... Midi -Pyr{\\ ’e)n{\\’e)les de l’Universit{\\e) Paul SabatierO, ADDRESS=*Toulouse, France’, NOTE=’ISBN 2-86332-130-7’, MONTH=08--13 June’, YEAR=�

[The neuroscientific work of Justo Gonzalo (1910-1986): the center syndrome and reversal metamorphopsia].

PubMed

Arias, M; Gonzalo, I

2004-10-01

The Spanish neuroscientist Justo Gonzalo Rodriguez-Leal (Barcelona 1910, Madrid 1986) carried out different studies on cerebral functions, highlighting those made in patients with encephalic injuries suffered during the Spanish civil war. His book "Investigaciones sobre la nueva dinámica cerebral. La actividad cerebral en función de las condiciones de excitabilidad nerviosa", published in two volumes (the first one in 1945 and the second one five years later), gathers some of his fundamental contributions, among which the so-called central syndrome stands out. A dominant parietal lesion (central) equidistant from the visual, sensorial and auditory projection areas can lead to diverse perceptive dysfunctions, among them inversions in visual, tactile and acoustic perception. As the lesion becomes more peripheral, the resulting defect will be more unisensorial and crossed, while when it approaches the central region, the disorders will be bilateral and polysensorial. Justo Gonzalo explained all these phenomena later by a gradient system.

Indolizidine 239Q and Quinolizidine 275I. Major alkaloids in two Argentinian bufonid toads (Melanophryniscus)

PubMed Central

Daly, John W.; Garraffo, H. Martin; Spande, Thomas F.; Yeh, Herman J. C.; Peltzer, Paola M.; Cacivio, Pedro; Baldo, J. Diego; Faivovich, Julián

2008-01-01

Alkaloid profiles in skin of poison frogs/toads (Dendrobatidae, Mantellidae, Bufonidae, and Myobatrachidae) are highly dependent on diet and hence on the nature of habitat. Extracts of the two species of toads (Melanophryniscus klappenbachi and M. cupreuscapularis) from similar habitats in the Corrientes/Chaco Provinces of Argentina have similar profiles of alkaloids, which differ considerably from profiles from other Melanophryniscus species from Brazil, Uruguay and Argentina. Structures of two major alkaloids 239Q (1) and 275I (2) were determined by mass, FTIR, and NMR spectral analysis as 5Z,9Z-3-(1-hydroxybutyl)-5-propylindolizidine and 6Z,10E-4,6-di(pent-4-enyl) quinolizidine, respectively. A third alkaloid, 249F (3), is postulated to be a homopumiliotoxin with an unprecedented conjugated exocyclic diene moiety. PMID:18848574

Non-pharmacological interventions to promote the sleep of patients after cardiac surgery: a systematic review.

PubMed

Machado, Fernanda de Souza; Souza, Regina Claudia da Silva; Poveda, Vanessa Brito; Costa, Ana Lucia Siqueira

2017-09-12

to analyze evidence available in the literature concerning non-pharmacological interventions that are effective to treat altered sleep patterns among patients who underwent cardiac surgery. systematic review conducted in the National Library of Medicine-National Institutes of Health, Cochrane Central Register of Controlled Trials, Latin American and Caribbean Health Sciences Literature, Scopus, Embase, Cumulative Index to Nursing and Allied Health Literature and PsycINFO databases, and also grey literature. ten controlled, randomized clinical trials were included in this review. Non-pharmacological interventions were grouped into three main categories, namely: relaxation techniques, devices or equipment to minimize sleep interruptions and/or induce sleep, and educational strategies. Significant improvement was found in the scores assessing sleep quality among studies testing interventions such as earplugs, sleeping masks, muscle relaxation, posture and relaxation training, white noise, and educational strategies. In regard to the studies' methodological quality, high quality studies as established by Jadad scoring were not found. significant improvement was found among the scores assessing sleep in the studies testing interventions such as earplugs, sleeping masks, muscle relaxation, posture and relaxation training, white noise and music, and educational strategies. analisar as evidências disponíveis, na literatura, sobre as intervenções não farmacológicas, efetivas para o tratamento da alteração do padrão do sono em pacientes submetidos à cirurgia cardíaca. revisão sistemática realizada por meio de busca nas bases de dados National Library of Medicine National Institutes of Health, Cochrane Central Register of Controlled Trials, Literatura Latino-Americana e do Caribe em Ciências da Saúde, Scopus, Embase, Cumulative Index to Nursing and Allied Health Literature e PsycINFO, e na literatura cinzenta. dez ensaios clínicos controlados e randomizados foram incluídos na revisão. Constatou-se que as intervenções não farmacológicas agruparam-se em três categorias principais, a saber: técnicas de relaxamento, dispositivos ou equipamentos para minimizar a interrupção do sono e/ou induzir o sono e estratégias educacionais. Houve melhoria significativa nos escores de avaliação do sono entre os estudos que testaram intervenções como tampões de ouvidos, máscara de olhos, relaxamento muscular, treinamento de postura e relaxamento, produção sonora e estratégia educacional. Em relação à qualidade metodológica dos estudos, não foram encontrados estudos considerados de alta qualidade pelo escore de Jadad. houve melhora significativa nos escores de avaliação do sono em estudos que avaliaram intervenções como tampões de ouvidos, máscara de olhos, relaxamento muscular, treinamento de postura e relaxamento, produção sonora e estratégia educacional. analizar las evidencias disponibles en la literatura sobre las intervenciones no farmacológicas, eficientes para el tratamiento de la alteración del patrón del sueño en pacientes sometidos a una cirugía cardíaca. revisión sistemática realizada mediante búsqueda en las bases de datos de la Librería Nacional de Medicina (National Library of Medicine), de los Institutos Nacionales de la Salud (National Institutes of Health), del Registro Central Cochrane de Ensayos Controlados (Cochrane Central Register of Controlled Trials), de la literatura latinoamericana y del Caribe, en Ciencias de la Salud, Scopus, Embase, Índice Acumulado de Enfermería y Literatura en Ciencias de la Salud, CINAHL (Cumulative Index to Nursing and Allied Health Literature) y PsycINFO, y en la literatura gris. se incluyeron en la revisión diez ensayos clínicos controlados y aleatorizados. Se constató que las intervenciones no farmacológicas se agruparon en tres categorías principales: técnicas de relajación, dispositivos o equipos para minimizar la interrupción del sueño y/o inducirlo, y estrategias educativas. Hubo una mejora significativa en las puntuaciones de la evaluación del sueño entre los estudios que probaron las intervenciones como tapón de oídos, máscara de ojos, relajación muscular, entrenamiento de postura y relajación, producción sonora y estrategia educacional. Con respecto a la calidad metodológica de los estudios, no se hallaron los considerados de alta calidad mediante la puntuación de Jadad. hubo una mejora significativa en las puntuaciones de la evaluación del sueño en los estudios que evaluaron intervenciones como tapones de oídos, máscara de ojos, relajación muscular, entrenamiento de postura y relajación, producción sonora y estrategia educacional.

Relación masa-radio para estrellas enanas blancas y la interpretación de recientes mediciones hechas por Hipparcos

NASA Astrophysics Data System (ADS)

Panei, J. A.; Althaus, L. G.; Benvenuto, O. G.

Recientes mediciones de la masa y el radio hechas por Hipparcos de las estrellas enanas blancas 40 Eri B y Procyon B (Shipman, H. & Provencal, J. - ApJ. 1998, 494, 759), sugieren un núcleo compuesto de hierro para dichas estrellas, en lugar de carbono y oxígeno como predice la teoría standard de evolución estelar. Para interpretar estas observaciones, presentamos aquí, relaciones masa-radio para configuraciones degeneradas a temperatura finita para distintas composiciones químicas centrales. Para tal fin hemos calculado secuencias evolutivas de enanas blancas utilizando el código de evolución estelar, desarrollado en el Observatorio de La Plata. Dicho código resuelve las ecuaciones de estructura y evolución estelar mediante la técnica de relajación de Henyey, y esta basado en una descripción física muy detallada y actualizada.

Neighborhood Reputation and Resident Sentiment in the Wake of the Las Vegas Foreclosure Crisis

PubMed Central

Pais, Jeremy; Batson, Christie D.; Monnat, Shannon M.

2014-01-01

This study examines how two major components of a neighborhood’s reputation—perceived disorder and collective efficacy—shape individuals’ sentiments toward their neighborhoods during the foreclosure crisis triggered by the Great Recession. Of central interest are whether neighborhood reputations are durable in the face of a crisis (neighborhood resiliency hypothesis) or whether neighborhood reputations wane during times of duress (foreclosure crisis hypothesis). Geo-coded individual-level data from the Las Vegas Metropolitan Area Social Survey merged with data on census tract foreclosure rates are used to address this question. The results provide qualified support for both perspectives. In support of the neighborhood resiliency hypothesis, collective efficacy is positively associated with how residents feel about the quality of their neighborhoods, and this relationship is unaltered by foreclosure rates. In support of the foreclosure crisis hypothesis, foreclosure rates mediate the effects of neighborhood disorder on resident sentiment. The implications of these findings for community resiliency are discussed. PMID:25678735

Discovery of a [WO] central star in the planetary nebula Th 2-A

NASA Astrophysics Data System (ADS)

Weidmann, W. A.; Gamen, R.; Díaz, R. J.; Niemela, V. S.

2008-09-01

Context: About 2500 planetary nebulae are known in our Galaxy but only 224 have central stars with reported spectral types in the Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (Acker et al. 1992; Acker et al. 1996). Aims: We have started an observational program aiming to increase the number of PN central stars with spectral classification. Methods: By means of spectroscopy and high resolution imaging, we identify the position and true nature of the central star. We carried out low resolution spectroscopic observations at CASLEO telescope, complemented with medium resolution spectroscopy performed at Gemini South and Magellan telescopes. Results: As a first outcome of this survey, we present for the first time the spectra of the central star of the PN Th 2-A. These spectra show emission lines of ionized C and O, typical in Wolf-Rayet stars. Conclusions: We identify the position of that central star, which is not the brightest one of the visual central pair. We classify it as of type [WO 3]pec, which is consistent with the high excitation and dynamical age of the nebula. Based on data collected at (i) the Complejo Astronómico El Leoncito (CASLEO), which is operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina y Universidades Nacionales de La Plata, Córdoba y San Juan, Argentina; (ii) the 6.5 m Magellan Telescopes at Las Campanas Observatory, Chile; (iii) the 8 m Gemini South Telescope, Chile.

Estudio de mutaciones en los genes IDH1 e IDH2 en una muestra de gliomas de población colombiana.

PubMed

Ricaurte, Orlando; Neita, Karina; Valero, Danyela; Ortega-Rojas, Jenny; Arboleda-Bustos, Carlos E; Zubieta, Camilo; Penagos, José; Arboleda, Gonzalo

2018-05-01

Introducción. Los gliomas son los tumores primarios más comunes del sistema nervioso central y se clasifican de I a IV según su grado de malignidad. En recientes investigaciones se ha encontrado que su aparición está relacionada con mutaciones en el exón 4 de los genes que codifican las deshidrogenasas de isocitrato 1 y 2 (IDH1: codón 132; IDH2: codón 172).Objetivo. Determinar la frecuencia de mutaciones en los genes IDH1 e IDH2 en una muestra de gliomas de pacientes colombianos.Materiales y métodos. La extracción de ADN se hizo a partir de tejido tumoral. El exón 4 de los genes IDH1 e IDH2 se amplificó mediante PCR utilizando iniciadores específicos y, posteriormente, se secuenciaron. Para la determinación de las mutaciones, se emplearon los programas 4Peaks y MAFFT.Resultados. Se determinó la presencia de mutaciones en el gen IDH1 en el 34 % de las muestras, con predominio de la mutación no sinónima R132H. En el 7,5 % de los casos se detectaron mutaciones en el gen IDH2, principalmente las mutaciones no sinónimas R172K y R172W.Conclusiones. La frecuencia de mutaciones en los genes IDH1 e IDH2 en la muestra fue similar a la reportada en otros estudios. El análisis de estas mutaciones puede ser importante como factor pronóstico y para su uso como potenciales blancos terapéuticos en gliomas.

U-Pb and Lu-Hf zircon geochronology of the Cañadón Asfalto Basin, Chubut, Argentina: Implications for the magmatic evolution in central Patagonia

NASA Astrophysics Data System (ADS)

Hauser, N.; Cabaleri, N. G.; Gallego, O. F.; Monferran, M. D.; Silva Nieto, D.; Armella, C.; Matteini, M.; Aparicio González, P. A.; Pimentel, M. M.; Volkheimer, W.; Reimold, W. U.

2017-10-01

The Cañadón Asfalto basin, central Chubut, Argentina, comprises a volcano-sedimentary sequence related to the opening of the Atlantic Ocean during Mesozoic times. The Lonco Trapial, Cañadón Asfalto and Cañadón Calcáreo formations are the main units related to the evolution of this basin. The Las Chacritas and Puesto Almada members are distinguished in the Cañadón Asfalto Formation. LA-HR-ICP-MS U-Pb and Lu-Hf data on zircon were obtained on these units. The Lonco Trapial Formation gave a weighted average age of 172.3 ± 1.8 Ma. A pyroclastic level from the Las Chacritas Member gave a weighted average age of 168.2 ± 2.2 Ma. Two U-Pb concordant ages of 160.3 ± 1.7 Ma on a laminated tuffite and 158.3 ± 1.3 Ma on a pyroclastic level were obtained for the Puesto Almada Member. Two maximum depositional ages constrain the sedimentary provenance areas for the basin: 1) A sample from the Sierra de la Manea range, where a controversial unit related either to the Cañadón Asfalto or to the Cañadón Calcáreo formation occurs, gave an age of 176.6 ± 1.0 Ma. Two younger zircon crystals indicate that this unit may be related to the Cañadón Calcáreo Formation. 2) A sandstone with cross-stratification from the Puesto Almada Member gave a maximum depositional age of 173.6 ± 6.4 Ma. In terms of U-Pb and Lu-Hf isotopes, two magmatic events are identified in central Patagonia: the Mamil Choique magmatic event characterized by negative εHf values around -5.0 and representing recycling during Permian times of Mesoproterozoic crust (TDM of ∼1.5 Ga), and the Cañadón Asfalto magmatic event with negative (-8.2) to positive (+4) εHf values and Meso- to Neoproterozoic TDM between 1.5 and 0.8 Ga. The younger event is characterized by three main cycles: C1 related to the Lonco Trapial magmatism, C2 to the Las Chacritas volcanism, and C3 to the Puesto Almada volcanism. These cycles are related with Marifil, Chon Aike and El Quemado formations volcanics events of Patagonia and the Neuquén Basin during the Mesozoic.

Checklist of vascular plants of the Department of Ñeembucú, Paraguay

PubMed Central

Egea, Juana De; Peña-Chocarro, Maria; Espada, Cristina; Knapp, Sandra

2012-01-01

Abstract The Department of Ñeembucú is one of the least well-documented areas of eastern Paraguay, and the flora is composed of a mixture of forest and Chaco elements. Regions like Ñeembucú are often considered of lower diversity and interest that more forested regions; this results from both actual species richness figures and from under-collecting due to perception as uninteresting. We present here a checklist of the vascular plants of Ñeembucú, which includes 676 taxa (including infraspecific taxa and collections identified only to genus) in 100 families and 374 genera. Four hundred and thirty nine (439) of these are new records for Ñeembucú and of these, 4 are new published records for Paraguay. Synonyms, distribution details within Paraguay and a voucher specimen or literature record are provided for each taxon, and a brief analysis of the diversity and importance of the flora is presented. PMID:22371688

A search for natural bioactive compounds in Bolivia through a multidisciplinary approach. Part VI. Evaluation of the antimalarial activity of plants used by Isoceño-Guaraní Indians.

PubMed

Bourdy, G; Oporto, P; Gimenez, A; Deharo, E

2004-08-01

Seventy-seven plant extracts (corresponding to 62 different species) traditionally used by the Isoceño-Guaraní, a native community living in the Bolivian Chaco, were screened for antimalarial activity in vitro on Plasmodium falciparum chloroquine sensitive strain (F32), and on ferriprotoporphyrin (FP) IX biocrystallisation inhibition test (FBIT). Among these extracts, seven displayed strong in vitro antimalarial activity, and 25 were active in the FBIT test. Positive results on both tests were recorded for six extracts: Argemone subfusiformis aerial part, Aspidosperma quebracho-blanco bark, Castela coccinea leaves and bark, Solanum argentinum leaves and Vallesia glabra bark. Results are discussed in relation with Isoceño-Guaraní traditional medicine. Further studies to be undertaken in relation with these results are also highlighted.

Initial sequence characterization of the rhabdoviruses of squamate reptiles, including a novel rhabdovirus from a caiman lizard (Dracaena guianensis)

PubMed Central

Wellehan, James F.X.; Pessier, Allan P.; Archer, Linda L.; Childress, April L.; Jacobson, Elliott R.; Tesh, Robert B.

2012-01-01

Rhabdoviruses infect a variety of hosts, including non-avian reptiles. Consensus PCR techniques were used to obtain partial RNA-dependent RNA polymerase gene sequence from five rhabdoviruses of South American lizards; Marco, Chaco, Timbo, Sena Madureira, and a rhabdovirus from a caiman lizard (Dracaena guianensis). The caiman lizard rhabdovirus formed inclusions in erythrocytes, which may be a route for infecting hematophagous insects. This is the first information on behavior of a rhabdovirus in squamates. We also obtained sequence from two rhabdoviruses of Australian lizards, confirming previous Charleville virus sequence and finding that, unlike a previous sequence report but in agreement with serologic reports, Almpiwar virus is clearly distinct from Charleville virus. Bayesian and maximum likelihood phylogenetic analysis revealed that most known rhabdoviruses of squamates cluster in the Almpiwar subgroup. The exception is Marco virus, which is found in the Hart Park group. PMID:22397930

Evaluation of an autochthonous starter culture on the production of a traditional dry fermented sausage from Chaco (Argentina) at a small-scale facility.

PubMed

Palavecino Prpich, Noelia Z; Garro, Oscar A; Romero, Mara; Judis, María A; Cayré, María E; Castro, Marcela P

2016-05-01

The performance of a mixed starter culture, SAS-1, comprised of the autochthonous strains Lactobacillus sakei ACU-2 and Staphylococcus vitulinus ACU-10, was evaluated into the production process of a traditional dry sausage. Microbiological, physicochemical and sensory analyses were carried out to accomplish this goal. Results showed an improvement in performance through the introduction of SAS-1; adding mixed starter culture rapidly decreased pH, inhibited the growth of contaminant microorganisms and enhanced the beneficial ones, diminished TBARS, and highlighted color and aroma attributes. However, most influential organoleptic descriptors among consumer acceptance were not affected by the addition of the starter. This starter culture would represent a valuable tool to improve the homogeneity of artisanal manufacture of this traditional food. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ethnoastronomy in the Multicultural Context of the Agricultural Colonies in Northern Santa Fe Province, Argentina

NASA Astrophysics Data System (ADS)

Mudrik, Armando

In this paper, we present a study about cultural astronomy among European colonists and their Argentinean descendants, in the context of a complex interaction between criollos, aboriginals and European colonists from different origins and religions, who settled in the northern area of the Argentinean province of Santa Fe, which is part of the southern Gran Chaco. These colonists arrived among waves of immigration occurring in Argentina in the second half of the nineteenth century and the first half of the twentieth century. Through ethnographic field research among these immigrants and their descendants, we carried out a survey of their astronomical representations and practices, and the connections of these with their social life and farming tasks. Through this we gained an insight as to how the astronomical ideas of immigrants, criollos and aboriginal groups influenced each other, generating a variety of new relations with the celestial realm.

[A review of thirty years of activity of the Research Program in Psychiatric Epidemiology (PEPSI) of the CONICET].

PubMed

Pavlovsky, Federico

2003-01-01

This article summarizes the activity of the Programa de Investigaciones en Epidemiología Psiquiátrica (PEPSI) (Research Program in Psychiatric Epidemiology) of the CONICET, directed for more than thirty years by Fernando Pages Larraya. After an anthropologic psychiatric experience done in the Gran Chaco Gualamba, by the end of the 60s, Pages Larraya and his team developed the theory of Cultural Isoidias, zones into which the country could be divided for epidemiologic studies. This article summarizes some of the principal lines of investigation of this program which departures from an initial study of the prevalence of mental diseases in Argentina. Other lines of research (such as a study about marginality, about Alzheimer's disease, about alcoholism and about AIDS) are summarized very briefly so as to give the reader an idea about the enormous field of study embraced by the PEPSI.

Skylab photography applied to geologic mapping in northwestern Central America

NASA Technical Reports Server (NTRS)

Rose, W. I., Jr.; Johnson, D. J.; Hahn, G. A.; Johns, G. W.

1975-01-01

Two photolineation maps of southwestern Guatemala and Chiapas were made from S190 photographs along a ground track from Acajutla, El Salvador to San Cristobal de las Casas, Mexico. The maps document a structural complexity spanning the presumed triple junction of the Cocos, Americas, and Caribbean plates. The Polochic fault zone, supposedly the Americas-Caribbean plate boundary, is a sharply delineated feature across western Guatemala. Westward of the Mexican border it splays into a large number of faults with NW to SW trends. The structural pattern is quite different to the north (Americas plate) and to the south (Caribbean plate) of the Polochic fault, though both areas are dominated by NW-trending lineations. Within the Central American volcanic chain, the lineation patterns support the segmented model of the Benioff Zone, by showing a concentration of transverse lineations in the predicted locations, most notably NE-trending elements near Quezaltenango, Guatemala. The structural pattern obtained from the maps are compared to patterns described on recently published maps of more southerly parts of Central America, to begin a synthesis of the structure of the convergent plate boundary.

Geologic and geophysical maps of the Las Vegas 30' x 60' quadrangle, Clark and Nye counties, Nevada, and Inyo County, California

USGS Publications Warehouse

Page, William R.; Lundstrom, Scott C.; Harris, Anita G.; Langenheim, V.E.; Workman, Jeremiah B.; Mahan, Shannon; Paces, James B.; Dixon, Gary L.; Rowley, Peter D.; Burchfiel, B.C.; Bell, John W.; Smith, Eugene I.

2005-01-01

Las Vegas and Pahrump are two of the fastest growing cities in the US, and the shortage of water looms as among the greatest future problems for these cities. These new maps of the Las Vegas 30 x 60-minute quadrangle provide a geologic and geophysical framework and fundamental earth science database needed to address societal issues such as ground water supply and contamination, surface flood, landslide, and seismic hazards, and soil properties and their changing impact by and on urbanization. The mountain ranges surrounding Las Vegas and Pahrump consist of Mesozoic, Paleozoic and Proterozoic rocks. A majority of these rocks are Paleozoic carbonate rocks that are part of Nevada's carbonate rock aquifer province. The Spring Mountains represent a major recharge site in the province, where maximum altitude is 3,632 m (Charleston Peak) above sea level. Rocks in the Sheep and Las Vegas Ranges and Spring Mountains contain correlative, northeast-striking, southeast-verging thrust faults that are part of the Cretaceous, Sevier orogenic belt. These thrusts were offset during the Miocene by the Las Vegas Valley shear system (LVVSZ). We conducted new mapping in the Blue Diamond area, highlighting refined work on the Bird Spring thrust, newly studied ancient landslides, and gravity-slide blocks. We conducted new mapping in the Las Vegas Range and mapped previously unrecognized structures such as the Valley thrust and fold belt; recognition of these structures has led to a refined correlation of Mesozoic thrust faults across the LVVSZ. New contributions in the quadrangle also include a greatly refined stratigraphy of Paleozoic bedrock units based on conodont biostragraphy. We collected over 200 conodont samples in the quadrangle and established stratigraphic reference sections used to correlate units across the major Mesozoic thrust faults. Quaternary deposits cover about half of the map area and underlie most of the present urbanized area. Deposits consist of large coalescing alluvial fans that grade downslope to extensive areas of fine-grained sediment indicative of groundwater-discharge during the Pleistocene. In the central areas of Las Vegas and Pahrump valleys, Quaternary fault scarps associated with past ground-water discharge deposits suggest a genetic relationship. In collaboration with NBMG and University of Nevada, a variety of ages of gravelly alluvium are newly mapped using surficial characteristics and soil development, along with reassessment of previously published mapping during compilation. Reconnaissance geochronology (thermoluminescence and U-series) of eolian and authigenic components of surficial and buried soils and spring deposits is applied to test hypotheses of geomorphic and hydrologic response to climate change over the past 100 k.y.). The major structure in the Las Vegas quadrangle is the LVVSZ. Because the LVVSZ is concealed by thick basin-fill deposits of Quaternary and Tertiary age, it was characterized primarily based on geophysics. Likewise, the newly described State line fault system in Pahrump Valley has also been characterized by geophysics, where geophysically inferred structures correlate remarkably with surface structures defined by our new geologic mapping in the Mound Spring and Hidden Hills Ranch 7.5-minute quadrangles.

Postwildfire preliminary debris flow hazard assessment for the area burned by the 2011 Las Conchas Fire in north-central New Mexico

USGS Publications Warehouse

Tillery, Anne C.; Darr, Michael J.; Cannon, Susan H.; Michael, John A.

2011-01-01

The Las Conchas Fire during the summer of 2011 was the largest in recorded history for the state of New Mexico, burning 634 square kilometers in the Jemez Mountains of north-central New Mexico. The burned landscape is now at risk of damage from postwildfire erosion, such as that caused by debris flows and flash floods. This report presents a preliminary hazard assessment of the debris-flow potential from 321 basins burned by the Las Conchas Fire. A pair of empirical hazard-assessment models developed using data from recently burned basins throughout the intermountain western United States was used to estimate the probability of debris-flow occurrence and volume of debris flows at the outlets of selected drainage basins within the burned area. The models incorporate measures of burn severity, topography, soils, and storm rainfall to estimate the probability and volume of debris flows following the fire. In response to a design storm of 28.0 millimeters of rain in 30 minutes (10-year recurrence interval), the probabilities of debris flows estimated for basins burned by the Las Conchas Fire were greater than 80 percent for two-thirds (67 percent) of the modeled basins. Basins with a high (greater than 80 percent) probability of debris-flow occurrence were concentrated in tributaries to Santa Clara and Rio del Oso Canyons in the northeastern part of the burned area; some steep areas in the Valles Caldera National Preserve, Los Alamos, and Guaje Canyons in the east-central part of the burned area; tributaries to Peralta, Colle, Bland, and Cochiti canyons in the southwestern part of the burned area; and tributaries to Frijoles, Alamo, and Capulin Canyons in the southeastern part of the burned area (within Bandelier National Monument). Estimated debris-flow volumes ranged from 400 cubic meters to greater than 72,000 cubic meters. The largest volumes (greater than 40,000 cubic meters) were estimated for basins in Santa Clara, Los Alamos, and Water Canyons, and for two basins at the northeast edge of the burned area tributary to Rio del Oso and Vallecitos Creek. The Combined Relative Debris-Flow Hazard Rankings identify the areas of highest probability of the largest debris flows. Basins with high Combined Relative Debris-Flow Hazard Rankings include upper Santa Clara Canyon in the northern section of the burn scar, and portions of Peralta, Colle, Bland, Cochiti, Capulin, Alamo, and Frijoles Canyons in the southern section of the burn scar. Three basins with high Combined Relative Debris-Flow Hazard Rankings also occur in areas upstream from the city of Los Alamos—the city is home to and surrounded by numerous technical sites for the Los Alamos National Laboratory. Potential debris flows in the burned area could affect the water supply for Santa Clara Pueblo and several recreational lakes, as well as recreational and archeological resources in Bandelier National Monument. Debris flows could damage bridges and culverts along State Highway 501 and other roadways. Additional assessment is necessary to determine if the estimated volume of material is sufficient to travel into areas downstream from the modeled basins along the valley floors, where they could affect human life, property, agriculture, and infrastructure in those areas. Additionally, further investigation is needed to assess the potential for debris flows to affect structures at or downstream from basin outlets and to increase the threat of flooding downstream by damaging or blocking flood mitigation structures. The maps presented here may be used to prioritize areas where erosion mitigation or other protective measures may be necessary within a 2- to 3-year window of vulnerability following the Las Conchas Fire.

Landslides triggered by Hurricane Mitch in Guatemala -- inventory and discussion

USGS Publications Warehouse

Bucknam, Robert C.; Coe, Jeffrey A.; Chavarria, Manuel Mota; Godt, Jonathan W.; Tarr, Arthur C.; Bradley, Lee-Ann; Rafferty, Sharon A.; Hancock, Dean; Dart, Richard L.; Johnson, Margo L.

2001-01-01

The torrential rains that accompanied Hurricane Mitch in October and November of 1998 triggered thousands of landslides in the moderate to steep terrain bordering the Motagua and Polochic Rivers in eastern Guatemala. Using aerial photographs taken between January and March 2000 we mapped all visible landslides larger than about 15 m in minimum dimension in a study area of 10,000 km2 encompassing twenty 1:50,000-scale topographic map quadrangles. Rainfall from Hurricane Mitch was exceptional because it was geographically widespread, prolonged over a period of about a week, moderate to heavy in intensity, and occurred at the end of the rainy season when the ground already had a high moisture content. As documented in this report, this type of rainfall, on saturated or nearly saturated ground, has the capability to trigger both shallow and deep-seated landslides over a large area. We mapped about 11,500 landslides in the study area. The mapped landslides were of two general types: relatively small, translational and rotational landslides that commonly mobilized into debris flows and covered less than several hectares in area (not including flow paths), and large, commonly translational, landslides that sometimes generated debris flows and covered between 15 ha and 25 ha (not including flow paths). The main concentrations of landslides are on moderate-to-steep hillslopes underlain by diverse geologic units. For the purpose of describing the mapped landslides, we divided the study area into five distinct regions based on differing geologic and geomorphic characteristics. These regions include the upper Polochic valley and surrounding highlands, the central Sierra de las Minas, the hills surrounding La Union and Zacapa, the eastern Sierra de las Minas, and the border region with Honduras. All of these areas received between 200 mm and 600 mm of rain over a 13-day period between October 25 and November 6. The highest rainfall amounts (400 mm to 600 mm) occurred in the Upper Polochic valley and surrounding highlands and in the central Sierra de las Minas. The lower rainfall amounts (200 mm to 400 mm) occurred in the hills surrounding La Union, the eastern Sierra de las Minas, and in the border region with Honduras. In general, the rainfall received in these areas is roughly equivalent to the average precipitation received in a 1-year period. We used 10-m digital elevation models (DEMs) generated from contours on two quadrangles in the central Sierra de las Minas to create a map showing areas that were susceptible to landslides during Hurricane Mitch. To create the Hurricane Mitch susceptibility map, we developed a susceptibility threshold equation based on elevation and gradient. The analysis indicates that, at least on two quadrangles, gradients less than 9? were not susceptible to landslides during Hurricane Mitch. The slope of the line defined by the threshold equation indicates that less rainfall was required to initiate landslides on steep gradients than on shallow gradients. Ninety percent of the mapped landslides that were triggered by Hurricane Mitch are within the susceptible zone shown on the map. Eightysix percent of landslides that were mapped as predating Hurricane Mitch, and all landslides mapped as postdating Hurricane Mitch, are within the susceptible zone. We used LAHARZ software to model the potential downstream area affected by debris if a large landslide dam on the Rio La Lima were to fail. The model shows that the area affected would be similar to the area that was affected by a debris flow that mobilized from a large landslide along the Rio La Lima during Hurricane Mitch. The characteristics of rainfall-triggered landslides described in this report can be used as a partial guide to future landslide activity triggered by rainstorms. On the basis of existing data, hazardous areas include: moderate to steep hillslopes and

Comparative and functional triatomine genomics reveals reductions and expansions in insecticide resistance-related gene families.

PubMed

Traverso, Lucila; Lavore, Andrés; Sierra, Ivana; Palacio, Victorio; Martinez-Barnetche, Jesús; Latorre-Estivalis, José Manuel; Mougabure-Cueto, Gaston; Francini, Flavio; Lorenzo, Marcelo G; Rodríguez, Mario Henry; Ons, Sheila; Rivera-Pomar, Rolando V

2017-02-01

Triatomine insects are vectors of Trypanosoma cruzi, a protozoan parasite that is the causative agent of Chagas' disease. This is a neglected disease affecting approximately 8 million people in Latin America. The existence of diverse pyrethroid resistant populations of at least two species demonstrates the potential of triatomines to develop high levels of insecticide resistance. Therefore, the incorporation of strategies for resistance management is a main concern for vector control programs. Three enzymatic superfamilies are thought to mediate xenobiotic detoxification and resistance: Glutathione Transferases (GSTs), Cytochromes P450 (CYPs) and Carboxyl/Cholinesterases (CCEs). Improving our knowledge of key triatomine detoxification enzymes will strengthen our understanding of insecticide resistance processes in vectors of Chagas' disease. The discovery and description of detoxification gene superfamilies in normalized transcriptomes of three triatomine species: Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis is presented. Furthermore, a comparative analysis of these superfamilies among the triatomine transcriptomes and the genome of Rhodnius prolixus, also a triatomine vector of Chagas' disease, and other well-studied insect genomes was performed. The expression pattern of detoxification genes in R. prolixus transcriptomes from key organs was analyzed. The comparisons reveal gene expansions in Sigma class GSTs, CYP3 in CYP superfamily and clade E in CCE superfamily. Moreover, several CYP families identified in these triatomines have not yet been described in other insects. Conversely, several groups of insecticide resistance related enzymes within each enzyme superfamily are reduced or lacking in triatomines. Furthermore, our qRT-PCR results showed an increase in the expression of a CYP4 gene in a T. infestans population resistant to pyrethroids. These results could point to an involvement of metabolic detoxification mechanisms on the high levels of pyrethroid resistance detected in triatomines from the Gran Chaco ecoregion. Our results help to elucidate the potential insecticide resistance mechanisms in vectors of Chagas' disease and provide new relevant information for this field. This study shows that metabolic resistance might be a contributing cause of the high pyrethroid resistance observed in wild T. infestans populations from the Gran Chaco ecoregion, area in which although subjected to intense pyrethroid treatments, vector control has failed. This study opens new avenues for further functional studies on triatomine detoxification mechanisms.

Comparative and functional triatomine genomics reveals reductions and expansions in insecticide resistance-related gene families

PubMed Central

Traverso, Lucila; Lavore, Andrés; Sierra, Ivana; Palacio, Victorio; Martinez-Barnetche, Jesús; Latorre-Estivalis, José Manuel; Mougabure-Cueto, Gaston; Francini, Flavio; Lorenzo, Marcelo G.; Rodríguez, Mario Henry; Ons, Sheila; Rivera-Pomar, Rolando V.

2017-01-01

Background Triatomine insects are vectors of Trypanosoma cruzi, a protozoan parasite that is the causative agent of Chagas’ disease. This is a neglected disease affecting approximately 8 million people in Latin America. The existence of diverse pyrethroid resistant populations of at least two species demonstrates the potential of triatomines to develop high levels of insecticide resistance. Therefore, the incorporation of strategies for resistance management is a main concern for vector control programs. Three enzymatic superfamilies are thought to mediate xenobiotic detoxification and resistance: Glutathione Transferases (GSTs), Cytochromes P450 (CYPs) and Carboxyl/Cholinesterases (CCEs). Improving our knowledge of key triatomine detoxification enzymes will strengthen our understanding of insecticide resistance processes in vectors of Chagas’ disease. Methods and findings The discovery and description of detoxification gene superfamilies in normalized transcriptomes of three triatomine species: Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis is presented. Furthermore, a comparative analysis of these superfamilies among the triatomine transcriptomes and the genome of Rhodnius prolixus, also a triatomine vector of Chagas’ disease, and other well-studied insect genomes was performed. The expression pattern of detoxification genes in R. prolixus transcriptomes from key organs was analyzed. The comparisons reveal gene expansions in Sigma class GSTs, CYP3 in CYP superfamily and clade E in CCE superfamily. Moreover, several CYP families identified in these triatomines have not yet been described in other insects. Conversely, several groups of insecticide resistance related enzymes within each enzyme superfamily are reduced or lacking in triatomines. Furthermore, our qRT-PCR results showed an increase in the expression of a CYP4 gene in a T. infestans population resistant to pyrethroids. These results could point to an involvement of metabolic detoxification mechanisms on the high levels of pyrethroid resistance detected in triatomines from the Gran Chaco ecoregion. Conclusions and significance Our results help to elucidate the potential insecticide resistance mechanisms in vectors of Chagas’ disease and provide new relevant information for this field. This study shows that metabolic resistance might be a contributing cause of the high pyrethroid resistance observed in wild T. infestans populations from the Gran Chaco ecoregion, area in which although subjected to intense pyrethroid treatments, vector control has failed. This study opens new avenues for further functional studies on triatomine detoxification mechanisms. PMID:28199333

The disjunct pattern of the Neotropical harvestman Discocyrtus dilatatus (Gonyleptidae) explained by climate-driven range shifts in the Quaternary: Paleodistributional and molecular evidence

PubMed Central

Vergara, Julia; González-Ittig, Raúl E.; Vaschetto, Luis M.; Gardenal, Cristina N.

2017-01-01

The disjunct distribution of the harvestman Discocyrtus dilatatus (Opiliones, Gonyleptidae) is used as a case study to test the hypothesis of a trans-Chaco Pleistocene paleobridge during range expansion stages. This would have temporarily connected humid regions (‘Mesopotamia’ in northeastern Argentina, and the ‘Yungas’ in the northwest, NWA) in the subtropical and temperate South American lowlands. The present study combines two independent approaches: paleodistributional reconstruction, using the Species Distribution Modeling method MaxEnt and projection onto Quaternary paleoclimates (6 kya, 21 kya, 130 kya), and phylogeographic analyses based on the cytochrome oxidase subunit I molecular marker. Models predict a maximal shrinkage during the warm Last Interglacial (130 kya), and the rise of the hypothesized paleobridge in the Last Glacial Maximum (21 kya), revealing that cold-dry stages (not warm-humid ones, as supposed) enabled the range expansion of this species. The disjunction was formed in the mid-Holocene (6 kya) and is intensified under current conditions. The median-joining network shows that NWA haplotypes are peripherally related to different Mesopotamian lineages; haplotypes from Santa Fe and Córdoba Provinces consistently occupy central positions in the network. According to the dated phylogeny, Mesopotamia-NWA expansion events would have occurred in the last glacial period, in many cases closely associated to the Last Glacial Maximum, with most divergence events occurring shortly thereafter. Only two (out of nine) NWA haplotypes are shared with Mesopotamian localities. A single, presumably relictual NWA haplotype was found to have diverged much earlier, suggesting an ancient expansion event not recoverable by the paleodistributional models. Different measures of sequence statistics, genetic diversity, population structure and history of demographic changes are provided. This research offers the first available evidence for the historical origin of NWA disjunct populations of a Mesopotamian harvestman. PMID:29141036

Antispasmodic effects and composition of the essential oils from two South American chemotypes of Lippia alba.

PubMed

Blanco, Marcos A; Colareda, Germán A; van Baren, Catalina; Bandoni, Arnaldo L; Ringuelet, Jorge; Consolini, Alicia E

2013-10-07

Lippia alba (Mill.) N. E. Brown (Verbenaceae) is an aromatic species used in Central and South America as eupeptic for indigestion. In Argentina, it is used by the "criollos" from the Chaco province. There are several chemotypes which differ in the chemical composition of the essential oils. Nowadays, it is experimentally cultivated in some countries of the region, including Argentina. To compare the chemical composition and pharmacology of the essential oils from two chemotypes: "citral" (CEO) and "linalool" (LEO), in isolated rat duodenum and ileum. Contractile concentration-response curves (CRC) of acetylcholine (ACh) and calcium in 40mM K(+)-medium (Ca(2+)-CRC) were done in isolated intestine portions, in the absence and presence of CEO or LEO at different concentrations. Likewise verapamil, CEO and LEO induced a non-competitive inhibition of the ACh-CRC, with IC50 of 7.0±0.3mg CEO/mL and 37.2±4.2mg LEO/mL. l-NAME, a NO-synthase blocker, increased the IC50 of CEO to 26.1±8.7mg CEO/mL. Likewise verapamil, CEO and LEO non-competitively inhibited the Ca(2+)-CRC, with IC50 of 6.3±1.7mg CEO/mL, 7.0±2.5mg LEO/mL and 0.24±0.04mg verapamil/mL (pIC50: 6.28). CEO was proved to possess limonene, neral, geranial and (-)-carvone as the major components, while LEO was rich in linalool. Results suggest that CEO has five times more potency than LEO to inhibit muscarinic contractions. The essential oils of both chemotypes interfered with the Ca(2+)-influx, but with an IC50 about 28 times higher than that of verapamil. Moreover, CEO partially stimulated the NO production. These results show the medicinal usefulness of both Lippia alba chemotypes, thus validating its traditional use, potency and mechanism of action. © 2013 Published by Elsevier Ireland Ltd.

Crop Expansion and Conservation Priorities in Tropical Countries

PubMed Central

Phalan, Ben; Bertzky, Monika; Butchart, Stuart H. M.; Donald, Paul F.; Scharlemann, Jörn P. W.; Stattersfield, Alison J.; Balmford, Andrew

2013-01-01

Expansion of cropland in tropical countries is one of the principal causes of biodiversity loss, and threatens to undermine progress towards meeting the Aichi Biodiversity Targets. To understand this threat better, we analysed data on crop distribution and expansion in 128 tropical countries, assessed changes in area of the main crops and mapped overlaps between conservation priorities and cultivation potential. Rice was the single crop grown over the largest area, especially in tropical forest biomes. Cropland in tropical countries expanded by c. 48,000 km2 per year from 1999–2008. The countries which added the greatest area of new cropland were Nigeria, Indonesia, Ethiopia, Sudan and Brazil. Soybeans and maize are the crops which expanded most in absolute area. Other crops with large increases included rice, sorghum, oil palm, beans, sugar cane, cow peas, wheat and cassava. Areas of high cultivation potential—while bearing in mind that political and socio-economic conditions can be as influential as biophysical ones—may be vulnerable to conversion in the future. These include some priority areas for biodiversity conservation in tropical countries (e.g., Frontier Forests and High Biodiversity Wilderness Areas), which have previously been identified as having ‘low vulnerability’, in particular in central Africa and northern Australia. There are also many other smaller areas which are important for biodiversity and which have high cultivation potential (e.g., in the fringes of the Amazon basin, in the Paraguayan Chaco, and in the savanna woodlands of the Sahel and East Africa). We highlight the urgent need for more effective sustainability standards and policies addressing both production and consumption of tropical commodities, including robust land-use planning in agricultural frontiers, establishment of new protected areas or REDD+ projects in places agriculture has not yet reached, and reduction or elimination of incentives for land-demanding bioenergy feedstocks. PMID:23326316

Variation of coda wave attenuation in the Alborz region and central Iran

NASA Astrophysics Data System (ADS)

Rahimi, H.; Motaghi, K.; Mukhopadhyay, S.; Hamzehloo, H.

2010-06-01

More than 340 earthquakes recorded by the Institute of Geophysics, University of Tehran (IGUT) short period stations from 1996 to 2004 were analysed to estimate the S-coda attenuation in the Alborz region, the northern part of the Alpine-Himalayan orogen in western Asia, and in central Iran, which is the foreland of this orogen. The coda quality factor, Qc, was estimated using the single backscattering model in frequency bands of 1-25 Hz. In this research, lateral and depth variation of Qc in the Alborz region and central Iran are studied. It is observed that in the Alborz region there is absence of significant lateral variation in Qc. The average frequency relation for this region is Qc = 79 +/- 2f1.07+/-0.08. Two anomalous high-attenuation areas in central Iran are recognized around the stations LAS and RAZ. The average frequency relation for central Iran excluding the values of these two stations is Qc = 94 +/- 2f0.97+/-0.12. To investigate the attenuation variation with depth, Qc value was calculated for 14 lapse times (25, 30, 35,... 90s) for two data sets having epicentral distance range R < 100 km (data set 1) and 100 < R < 200 km (data set 2) in each area. It is observed that Qc increases with depth. However, the rate of increase of Qc with depth is not uniform in our study area. Beneath central Iran the rate of increase of Qc is greater at depths less than 100 km compared to that at larger depths indicating the existence of a high attenuation anomalous structure under the lithosphere of central Iran. In addition, below ~180 km, the Qc value does not vary much with depth under both study areas, indicating the presence of a transparent mantle under them.

Blood pressure, left ventricular geometry, and systolic function in children exposed to inorganic arsenic.

PubMed

Osorio-Yáñez, Citlalli; Ayllon-Vergara, Julio C; Arreola-Mendoza, Laura; Aguilar-Madrid, Guadalupe; Hernández-Castellanos, Erika; Sánchez-Peña, Luz C; Del Razo, Luz M

2015-06-01

Inorganic arsenic (iAs) is a ubiquitous element present in the groundwater worldwide. Cardiovascular effects related to iAs exposure have been studied extensively in adult populations. Few epidemiological studies have been focused on iAs exposure-related cardiovascular disease in children. In this study we investigated the association between iAs exposure, blood pressure (BP), and functional and anatomical echocardiographic parameters in children. A cross-sectional study of 161 children between 3 and 8 years was conducted in Central Mexico. The total concentration of arsenic (As) species in urine (U-tAs) was determined by hydride generation-cryotrapping-atomic absorption spectrometry and lifetime iAs exposure was estimated by multiplying As concentrations measured in drinking water by the duration of water consumption in years (LAsE). BP was measured by standard protocols, and M-mode echocardiographic parameters were determined by ultrasonography. U-tAs concentration and LAsE were significantly associated with diastolic (DBP) and systolic blood pressure (SBP) in multivariable linear regression models: DBP and SBP were 0.013 (95% CI: 0.002, 0.024) and 0.021 (95% CI: 0.004, 0.037) mmHg higher in association with each 1-ng/mL increase in U-tAs (p < 0.025), respectively. Left ventricular mass (LVM) was significantly associated with LAsE [5.5 g higher (95% CI: 0.65, 10.26) in children with LAsE > 620 compared with < 382 μg/L-year; p = 0.03] in an adjusted multivariable model. The systolic function parameters left ventricular ejection fraction (EF) and shortening fraction were 3.67% (95% CI: -7.14, -0.20) and 3.41% (95% CI: -6.44, -0.37) lower, respectively, in children with U-tAs > 70 ng/mL compared with < 35 ng/mL. Early-life exposure to iAs was significantly associated with higher BP and LVM and with lower EF in our study population of Mexican children.

Seguridad del paciente en Radioterapia Intraoperatoria: Impacto de los elementos controlados por el Radiofisico

NASA Astrophysics Data System (ADS)

Tarjuelo, Juan Lopez

Introduccion: En la administracion de la radioterapia intervienen profesionales y equipos de tratamiento, por lo que existe el riesgo de error y se precisa que dicho equipamiento funcione conforme a lo esperado. A los radiofisicos les corresponde participar en las actividades de garantia o aseguramiento de la calidad, incluyendo el control de calidad de los equipos, y en la evaluacion de los riesgos asociados. La radioterapia intraoperatoria (RIO) es una tecnica radioterapica de intensificacion de dosis, altamente selectiva, dirigida a volumenes anatomicos restringidos durante el tratamiento quirurgico oncologico, basada en la administracion de una dosis absorbida alta por medio de un haz de electrones tras el examen visual directo del lecho tumoral. Como incorporar los ultimos avances en el refuerzo de la seguridad en radioterapia es una tarea ambiciosa y compleja, resulta mas concreta y de inmediata aplicacion su introduccion en la RIO. El objetivo es analizar los elementos que reducen los riesgos y aumentan la seguridad en la RIO y su dosimetria, y valorar la funcion del radiofisico en esta labor. Material y metodos: Se emplearon el planificador Radiance de GMV y el acelerador lineal de los tratamientos de RIO Elekta Precise, controlado con el verificador diario de haces Daily QA Check 1090 y medido con las camaras de ionizacion PPC 40, FC65-G y FC65-P de PTW-Freiburg, a su vez verificadas con fuentes radiactivas adecuadas de estroncio-90 modelos CDP y CDC de IBA Dosimetry. Se realizo un analisis de modos de fallo y efectos (failure mode and effect analysis, FMEA) con el fin de identificar los elementos que forman la RIO y aplicar las herramientas necesarias para la minimizacion de los riesgos y la mejora de la seguridad en la tecnica. Se estudiaron las verificaciones diarias de dicho acelerador Precise con el control estadistico de procesos (statistical process control, SPC) y se simularon intervenciones para devolverlo al estado llamado en control. El SPC tambien se uso para estudiar la estabilidad de las camaras de ionizacion mencionadas. Se realizo la dosimetria in vivo en 45 pacientes con MOSFET reforzados mobile TN-502RDM-H, pelicula radiocromica Gafchromic MD-55-2, y se elaboro un modelo teorico para explicar los datos. Por ultimo, al precisarse el uso en RIO de la simulacion virtual y del calculo de la dosis absorbida en el paciente virtual, se ha ilustrado este apartado con la aceptacion y el estado de referencia inicial del planificador de tratamientos modulados con calculo de Monte Carlo Elekta Monaco. Para ello se utilizaron la camara de ionizacion TW31016-0104 y la matriz seven29 de PTW-Freiburg, pelicula radiocromica Gafchromic EBT-2, y diferentes maniquies. Resultados: El FMEA identifico 57 modos de fallo y efectos potenciales. No se experimentaron sucesos relativos a una administracion inadecuada de la dosis absorbida. Se identificaron las revisiones dobles y por un par como claves para reducir los riesgos asociados al equipo de profesionales involucrado en la RIO. Se identificaron tambien oportunidades de mejora con el uso de la automatizacion y el enclavamiento. En cuanto al SPC, los indices de capacidad del proceso abarcaron de 1,6 a 9,3 para un nivel de especificaciones del +/-2%. Las intervenciones simuladas alcanzaron del 2% al 34% de las sesiones de medida. Las camaras de ionizacion Farmer derivaron en direcciones opuestas en un periodo de 6 anos; aunque ello no se aprecio en los informes de calibracion del laboratorio acreditado. No derivo la camara PPC-40. En la dosimetria in vivo, las medidas de los MOSFET no se desviaron significativamente de las medidas con pelicula. Los valores centrales de las dosis absorbidas quedaron entre la dosis absorbida prescrita y la maxima, con lo que indicaron un tratamiento correcto del lecho tumoral. Las anchuras de los intervalos de confianza de las dosis absorbidas esperadas segun el modelo teorico al nivel del 95% abarcaron del 8,6% al 14,7%. Las verificaciones de Monaco resultaron satisfactorias excepto en el caso de la transferencia de datos, que obligo a cambiar el flujo de trabajo. Conclusiones: El FMEA es crucial para priorizar las intervenciones reductoras del riesgo. Tipos diferentes de procesos fallidos se pueden eliminar o paliar con tipos diferentes de tales intervenciones. El SPC puede evaluar la variabilidad inherente del procedimiento monitorizador de haces de electrones, indica cuando intervenir para devolver un proceso al estado de control y si un proceso es capaz con respecto a unas especificaciones o requisitos establecidos. Es viable realizar dosimetria in vivo con un acelerador convencional fijo y obtener resultados satisfactorios en cada localizacion estudiada a pesar de su variabilidad. El modelo teorico desarrollado puede describir con exito resultados globales, aunque no puede explicar todos los datos experimentales. Se ha mostrado que un planificador puede funcionar correctamente en condiciones de laboratorio o trabajando solo; pero puede fallar cuando se conecta con otros equipos de radioterapia. Todos estos aspectos presentados y evaluados aqui constituyen competencias actuales o futuras, y deseables, de los radiofisicos, tanto en el campo de la RIO como en la extension a la radioterapia en su conjunto.

The Las Vegas Valley Seismic Response Project: Ground Motions in Las Vegas Valley from Nuclear Explosions at the Nevada Test Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodgers, A; Tkalcic, H; McCallen, D

2005-03-18

Between 2001-2004 the Las Vegas Seismic Response Project has sought to understand the response of Las Vegas Valley (LVV) to seismic excitation. In this study, the author report the findings of this project with an emphasis on ground motions in LVV from nuclear explosions at the Nevada Test Site (NTS). These ground motions are used to understand building structural response and damage as well as human perception. Historical nuclear explosion observations are augmented with earthquake recordings from a temporary deployment of seismometers to improve spatial coverage of LVV. The nuclear explosions were conducted between 1968 and 1989 and were recordedmore » at various sites within Las Vegas. The data from past nuclear tests were used to constrain ground motions in LVV and to gain a predictive capability of ground motions for possible future nuclear tests at NTS. Analysis of ground motion data includes peak ground motions (accelerations and velocities) and amplification of basin sites relative to hard rock sites (site response). Site response was measured with the Standard Spectral Ratios (SSR) technique relative to hard rock reference sites on the periphery of LVV. The site response curves indicate a strong basin amplification of up to a factor of ten at frequencies between 0.5-2 Hz. Amplifications are strongest in the central and northern portions of LVV, where the basin is deeper than 1 km based on the reported basin depths of Langenheim et al (2001a). They found a strong correlation between amplification and basin depth and shallow shear wave velocities. Amplification below 1 Hz is strongly controlled by slowness-averaged shear velocities to depths of 30 and 100 meters. Depth averaged shear velocities to 10 meters has modest control of amplifications between 1-3 Hz. Modeling reveals that low velocity material in the shallow layers (< 200 m) effectively controls amplification. They developed a method to scale nuclear explosion ground motion time series to sites around LVV that have no historical record of explosions. The method is also used to scale nuclear explosion ground motions to different yields. They also present a range of studies to understand basin structure and response performed on data from the temporary deployment.« less

Mapa Geologico de Venezuela a Escala 1:750,000

USGS Publications Warehouse

Hackley, Paul C.; Urbani, Franco; Karlsen, Alex W.; Garrity, Christopher P.

2006-01-01

Se presenta un mapa geologico digital de Venezuela sobre un fondo de relieve sombreado. Los datos geologicos e hidrologicos del norte del rio Orinoco proceden de la digitalizacion de mapas geologicos en papel a escala 1:500.000. Estos datos fueron integrados con el mapa geologico digital del Escudo de Guayana Venezolano, a su vez derivado de hojas en papel a escala 1:500.000. La informacion sobre los tipos de fallas mostrados en el mapa es igual que en las fuentes originales. Los poligonos geologicos fueron atribuidos por edad, litologia y nombre de la unidad siguiendo el Codigo geologico de Venezuela. Se incorporaron revisiones significativas de la geologia de la Cordillera de la Costa a partir de las nuevas hojas integradas a escala 1:25.000. Toda esta informacion geologico-estructural se sobrepuso a una imagen de relieve sombreado, producida por el procesamiento de los datos de radar interferometrico con 90 m (3 arcosegundos) de resolucion espacial obtenidos por la mision topografica de radar del transbordador espacial (SRTM). Las areas de la base de datos del SRTM carentes de informacion fueron llenadas por medio de la interpolacion de los datos de las celdas adyacentes. Para producir la imagen de relieve sombreado se uso una direccion de iluminacion de 315 deg con un angulo de 65 deg sobre el horizonte. La proyeccion usada en el mapa es conica equidistante, con latitudes de 4 y 9 deg norte como paralelos estandar y una longitud de 66 deg al oeste como meridiano central. Los datos en el mapa proceden primordialment de hojas a escala 1:500.000 y el producto esta preparado para una impresion optima en escala 1:750.000. Los usuarios pueden obtener ampliaciones mayores, sin embargo no se garantiza la precision del mapa a escalas mas detalladas. Especialmente en la region de Guayana, al sobreponer los mapas geologicos sobre la reciente imagen SRTM, se notan grandes discrepancias no sistematicas tanto en contactos como en fallas. Esto es debido a que los mapas geologicos de Guayana tienen como base topografica las imagenes de radar de vision lateral (SLAR), con muy control de campo de los a?os 1970's. La correccion de estos desfases esta planificada para el futuro.

Emergent and Reemergent Arboviruses in South America and the Caribbean: Why So Many and Why Now?

PubMed

Marcondes, Carlos Brisola; Contigiani, Marta; Gleiser, Raquel Miranda

2017-05-01

Varios arbovirus han emergido y/o reemergido en el Nuevo Mundo en las últimas décadas. Los virus Zika y chikungunya, anteriormente restringidos a África y quizás Asia, invadieron el continente, causando gran preocupación; además siguen ocurriendo brotes causados por el virus dengue en casi todos los países, con millones de casos por año. El virus West Nile invadió rápidamente América del Norte, y ya se han encontrado casos en América Central y del Sur. Otros arbovirus, como Mayaro y el virus de la encefalitis equina del este han aumentado su actividad y se han encontrado en nuevas regiones. Se han documentado cambios en la patogenicidad de algunos virus que conducen a enfermedades inesperadas. Una fauna diversa de mosquitos, cambios climáticos y en la vegetación, aumento de los viajes, y urbanizaciones no planificadas que generan condiciones adecuadas para la proliferación de Aedes aegypti (L.), Culex quinquefasciatus Say y otros mosquitos vectores, se han combinado para influir fuertemente en los cambios en la distribución y la incidencia de varios arbovirus. Se enfatiza la necesidad de realizar estudios exhaustivos de la fauna de mosquitos y modificaciones de las condiciones ambientales, sobre todo en las zonas urbanas fuertemente influenciadas por factores sociales, políticos y económicos. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

DOE Office of Scientific and Technical Information (OSTI.GOV)

May, R.T.; Strand, J.R.; Reid, B.E.

Uranium favorability of the Sangre de Cristo Formation (Pennsylvanian-Permian) in the Las Vegas basin has been evaluated. The Las Vegas basin project area, located in Colfax, Mora, and San Miguel Counties, New Mexico, comprises about 3,489 sq mi. The formation contains sedimentologic and stratigraphic characteristics that are considered favorable for uranium deposition. Field investigations consisted of section measuring, rock sampling, and ground radiometric reconnaissance. North-south and east-west cross sections of the basin were prepared from well logs and measured sections. Petrographic, chemical, and spectrographic analyses were conducted on selected samples. Stratigraphic and sedimentologic information were used to determine depositional environments.more » The most favorable potential host rocks include red to pink, coarse-grained, poorly sorted, feldspathic to arkosic lenticular sandstones with stacked sandstone thicknesses of more than 20 ft and sandstone-to-shale ratios between 1:1 and 2:1. The sandstone is interbedded with mudstone and contains carbonaceous debris and anomalous concentrations of uranium locally. Areas of maximum favorability are found in a braided-stream, alluvial-plain depositional environment in the north-central part of the Las Vegas basin. There, carbonaceous material is well preserved, probably due to rapid subsidence and burial. Furthermore, uranium favorability is highest in the lower half of the formation because carbonaceous wood and plant fragments, as well as known uranium deposits, are concentrated in this zone. Piedmont deposits in the north and east, and meander-belt, alluvial-plain deposits in the south, are not considered favorable because of the paucity of uranium deposits and a minimum of carbonaceous material.« less

Población de galaxias de baja luminosidad en cúmulos

NASA Astrophysics Data System (ADS)

Valotto, C. A.; Muriel, H.; Moore, B.; García Lambas, D.

En este trabajo se discute sobre la presencia de un exceso de galaxias de baja luminosidad en medios de alta densidad de galaxias y la posibilidad de que los halos de galaxias cD puedan ser formados a partir de galaxias en cúmulos ricos, los cuales muestran una función de luminosidad (FL) con el extremo débil plano. Se analizaron muestras de cúmulos cercanos obtenidas a partir de los catálogos de Abell y X-ray Sample of Bright Clusters. Los resultados obtenidos muestran que los cúmulos de galaxias que tienen emisión en rayos X detectada poseen una FL plana (α ≈ -1.2), consistente con los valores encontrados para las galaxias de campo. En cambio, los cúmulos de galaxias identificados a partir de distribuciones bidimensionales de galaxias que no tienen su contraparte en rayos X, muestran una FL con una pendiente pronunciada en el extremo débil (α ≈ -1.6). Se examinaron además, los posibles efectos debido a la presencia de una galaxia central dominante sobre el extremo débil de la FL. Se analizaron muestras de acuerdo a la clasificación Bautz-Morgan dividiendo en las submuestras I,I-II y II, II- III, III. Las FL resultantes para ambas muestras son indistinguibles. Nuestros resultados son consistentes con la hipótesis de que los efectos de proyección en cúmulos identificados en dos dimensiones pueden producir un exceso artificial de galaxias de baja luminosidad.

Spatio-temporal variability of NDVI-precipitation over southernmost South America: possible linkages between climate signals and epidemics

NASA Astrophysics Data System (ADS)

Tourre, Y. M.; Jarlan, L.; Lacaux, J.-P.; Rotela, C. H.; Lafaye, M.

2008-10-01

Climate-environment variability affects the rates of incidence of vector-borne and zoonotic diseases and is possibly associated with epidemics outbreaks. Over southernmost South America the joint spatio-temporal evolution of climate-environment is analyzed for the 1982-2004 period. Detailed mapping of normalized difference vegetation index (NDVI) and rainfall variability are then compared to zones with preliminary epidemiological reports. A significant quasi-biennial signal (2.2- to 2.4-year periods, or QB) for joint NDVI-rainfall variability is revealed. From rotated EOFs, dominant NDVI patterns are partitioned according to their lead frequencies: (1) the 'QB group' (2.1-to 3-year periods) includes six modes over southern Brazil, Uruguay, northern-central Argentina (two modes), the southern Paraguay-northern Argentina border, and the Santa Cruz Province; (2) the QB1 (2.4- to 3-year periods) + quasi-quadrennial (QQ) mode over the Misiones Province; and (3) the QB2 (2.1- to 2.5-year periods) + QQ + inter-annual (IA) (3- to 7-year periods) two modes over south-eastern Argentina. Modes within the 'QB group' are positively correlated with global climate signals and SST. The Uruguayan mode is correlated with global ENSO (8-month lag) whilst the southern Entre-Rios/northern Buenos Aires provinces are correlated with central equatorial Pacific SSTs (3-month lag). The Santa Cruz (Patagonia) Province is most correlated with the Pacific South America (PSA) index and SST patterns (3-month lag) along the Antarctica circumpolar current. The spatial distribution of lead NDVI modes includes the Formosa, Misiones, Chaco and Buenos Aires provinces among others, known for being prone to vector-borne epidemics such as dengue fever, malaria, leishmaniasis (American cutaneous leishmaniasis or ACL), hantivirus, chagas and Argentine hemorrhagic fever (AHF). Some provinces also correspond to regions where lead NDVI PCs' modes are associated with high-frequency climate signals such as the quasi-biennial oscillation in northwest Argentina. The joint preliminary results (climate-environment-public health reports) presented here for the first time are meant: (1) to contribute to a better understanding of climate-environment-epidemics process-based and modeling studies and (2) to facilitate, in the long run, the implementation of local and regional health early warning systems (HEWS) over southernmost South America. The latter is becoming crucial with ever-increasing migration, urban sprawl (re-emergence of dengue fever epidemics since the late 1990s), all embedded in a climate change context.

Growth, nutrient status, and photosynthetic response to diesel-contaminated soil of a cordgrass, Spartina argentinensis.

PubMed

Redondo-Gómez, Susana; Petenello, María C; Feldman, Susana R

2014-02-15

The present study was conduced to investigate the tolerance limits of Spartina argentinensis, which occurs in inland marshes of the Chaco-Pampean regions of Argentina, to diesel-contaminated soil. A glasshouse experiment was designed to investigate the effect of diesel fuel from 0% to 3% on growth and photosynthetic apparatus of S. densiflora by measuring gas exchange and photosynthetic pigments. We also performed chemical analysis of plant samples, and determined mycorrhizal index. Tiller and root biomasses declined with increasing diesel fuel concentration, as well as photosynthetic rate (A). Reductions in A could be accounted for by non-stomatal limitations. Mycorrhizal roots of S. argentinensis were reduced by the presence of diesel fuel, but did not affect its nutritional status; in fact, most element concentrations increased with diesel contamination. Despite the negative effect of diesel-contaminated soil, S. argentinensis continued growing, which could be useful management options for phytorremediation of diesel-contaminated soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

Initial sequence characterization of the rhabdoviruses of squamate reptiles, including a novel rhabdovirus from a caiman lizard (Dracaena guianensis).

PubMed

Wellehan, James F X; Pessier, Allan P; Archer, Linda L; Childress, April L; Jacobson, Elliott R; Tesh, Robert B

2012-08-17

Rhabdoviruses infect a variety of hosts, including non-avian reptiles. Consensus PCR techniques were used to obtain partial RNA-dependent RNA polymerase gene sequence from five rhabdoviruses of South American lizards; Marco, Chaco, Timbo, Sena Madureira, and a rhabdovirus from a caiman lizard (Dracaena guianensis). The caiman lizard rhabdovirus formed inclusions in erythrocytes, which may be a route for infecting hematophagous insects. This is the first information on behavior of a rhabdovirus in squamates. We also obtained sequence from two rhabdoviruses of Australian lizards, confirming previous Charleville virus sequence and finding that, unlike a previous sequence report but in agreement with serologic reports, Almpiwar virus is clearly distinct from Charleville virus. Bayesian and maximum likelihood phylogenetic analysis revealed that most known rhabdoviruses of squamates cluster in the Almpiwar subgroup. The exception is Marco virus, which is found in the Hart Park group. Copyright © 2012 Elsevier B.V. All rights reserved.

Where did the chili get its spice? Biogeography of capsaicinoid production in ancestral wild chili species.

PubMed

Tewksbury, Joshua J; Manchego, Carlos; Haak, David C; Levey, Douglas J

2006-03-01

The biogeography of pungency in three species of wild chili in the chaco and surrounding highland habitats of southeastern Bolivia is described. We report that Capsicum chacoense, C. baccatum, and C. eximium are polymorphic for production of capsaicin and its analogs, such that completely pungent and completely nonpungent individuals co-occur in some populations. In C. chacoense, the density of plants and the proportion of pungent plants increased with elevation. Above 900 m, all individuals in all populations except two were pungent; nonpungent individuals in at least one of the two polymorphic populations were likely a result of spreading by humans. The occurrence of pungent and nonpungent individuals in three species of ancestral Capsicum and the geographic variation of pungency within species suggest that production of capsaicin and its analogs entails both costs and benefits, which shift from one locality to another. Determining the selection pressures behind such shifts is necessary to understand the evolution of pungency in chilies.

Positive selection of AS3MT to arsenic water in Andean populations

PubMed Central

Eichstaedt, Christina A.; Antao, Tiago; Cardona, Alexia; Pagani, Luca; Kivisild, Toomas; Mormina, Maru

2016-01-01

Arsenic is a carcinogen associated with skin lesions and cardiovascular diseases. The Colla population from the Puna region in Northwest Argentinean is exposed to levels of arsenic in drinking water exceeding the recommended maximum by a factor of 20. Yet, they thrive in this challenging environment since thousands of years and therefore we hypothesize strong selection signatures in genes involved in arsenic metabolism. We analyzed genome-wide genotype data for 730,000 loci in 25 Collas, considering 24 individuals of the neighbouring Calchaquíes and 24 Wichí from the Gran Chaco region in the Argentine province of Salta as control groups. We identified a strong signal of positive selection in the main arsenic methyltransferase AS3MT gene, which has been previously associated with lower concentrations of the most toxic product of arsenic metabolism monomethylarsonic acid. This study confirms recent studies reporting selection signals in the AS3MT gene albeit using different samples, tests and control populations. PMID:26366667

Microgeographical study of insecticide resistance in Triatoma infestans from Argentina.

PubMed

Germano, Mónica D; Picollo, María Inés; Mougabure-Cueto, Gastón A

2013-12-01

Chagas disease is a chronic parasitic infection restricted to America where it is currently estimated that 90 million people are at risk of acquiring the infection. Chemical control with pyrethroid insecticides has been effective to reduce disease transmission in several areas of the Southern Cone, although insecticide resistance has evolved and diminished the campaigns' results. Considering previous reports on the different levels of resistance between Triatoma infestans from different geographical areas, the objective of this work was to determine if T. infestans populations are toxicologically structured within localities. Response to the insecticide was measured and compared between houses of two Argentine localities. Different toxicity of deltamethrin was detected between dwellings of Chaco province, accounting for both susceptible and resistant houses within the same locality. However no difference was found among houses of Salta province. The results obtained in this work suggest that geographical structure is present not only at the between localities level, but also at the microgeograhical level. Copyright © 2013 Elsevier B.V. All rights reserved.

Remote sensing and geographic database management systems applications for the protection and conservation of cultural heritage

NASA Astrophysics Data System (ADS)

Palumbo, Gaetano; Powlesland, Dominic

1996-12-01

The Getty Conservation Institute is exploring the feasibility of using remote sensing associated with a geographic database management system (GDBMS) in order to provide archaeological and historic site managers with sound evaluations of the tools available for site and information management. The World Heritage Site of Chaco Canyon, New Mexico, a complex of archeological sites dating to the 10th to the 13th centuries AD, was selected as a test site. Information from excavations conducted there since the 1930s, and a range of documentation generated by the National Park Service was gathered. NASA's John C. Stennis Space Center contributed multispectral data of the area, and the Jet Propulsion Laboratory contributed data from ATLAS (airborne terrestrial applications sensor) and CAMS (calibrated airborne multispectral scanner) scanners. Initial findings show that while 'automatic monitoring systems' will probably never be a reality, with careful comparisons of historic and modern photographs, and performing digital analysis of remotely sensed data, excellent results are possible.

INCIDENCE OF TRYPANOSOMA CRUZI INFECTION AMONG CHILDREN FOLLOWING DOMESTIC REINFESTATION AFTER INSECTICIDE SPRAYING IN RURAL NORTHWESTERN ARGENTINA

PubMed Central

GÜRTLER, RICARDO E.; CECERE, MARÍA C.; LAURICELLA, MARTA A.; PETERSEN, ROSARIO M.; CHUIT, ROBERTO; SEGURA, ELSA L.; COHEN, JOEL E.

2005-01-01

Following increasing reinfestation with Triatoma infestans after insecticide spraying, the household incidence of infection with Trypanosoma cruzi in children was positively related to the domestic abundance of infected T. infestans and the presence or proportion of infected dogs or cats in Amamá, a rural village in northwestern Argentina. Seven (12.1%) children seronegative for antibodies to T. cruzi at baseline, with no history of travel or blood transfusion, seroconverted after three years. Six incident cases lived in houses heavily infested with T. infestans, with high proportions of bugs infected with T. cruzi and having fed on humans or dogs. The remaining incident case occurred under a very light domestic infestation detected only at the endpoint, and most bugs had fed on humans. Dogs had a 17 times greater force of infection than children (4.3% per year). Sustained vector surveillance is crucially needed in high-risk areas for Chagas disease such as the Gran Chaco. PMID:16014842

Actitudes de los candidatos y maestros de ciencias en servicio acerca del uso de las herramientas computadorizadas en las clases de ciencias

NASA Astrophysics Data System (ADS)

Bayuelo, Ezequiel

Este estudio examino y comparo las actitudes de los candidatos a maestros de ciencias y los maestros de ciencias en servicio acerca de la utilizacion de las herramientas computadorizadas en las clases de ciencias. Tambien identifico y diferencio el uso que ellos dan a estas herramientas en las clases de ciencias. Este estudio presenta un diseno descriptivo exploratorio. Constituyeron la muestra trescientos diez sujetos que fueron candidatos a maestros de ciencias o maestros de ciencias en servicio. Para recoger los datos se construyo y valido un cuestionario de treinta y un itemes. Se utilizaron las pruebas estadisticas no parametricas Kruskal Wallis y Chi-cuadrado (test de homogeneidad) para establecer las diferencias entre las actitudes de los sujetos con relacion al uso de las herramientas computadorizadas en las clases de ciencias. Los hallazgos evidenciaron que son positivas y muy parecidas las actitudes de los candidatos a maestros y maestros en servicio hacia el uso de las herramientas computadorizadas. No hubo diferencias entre los candidatos y maestros en servicio en terminos de las actitudes de confianza y empatia hacia el uso de las herramientas computadorizadas en las clases de ciencias. En aspectos como el uso del banco de datos bibliografico Eric y el uso de las herramientas computadorizadas en actividades educativas como explorar conceptos, conceptuar, aplicar lo aprendido y hacer asignaciones hubo diferencias estadisticamente significativas entre los candidatos y los maestros en servicio. Al comparar las frecuencias observadas con las esperadas hubo mas maestros en servicio y menos candidatos que indicaron usar el anterior banco de datos y las herramientas computadorizadas en las mencionadas actividades educativas.

Fuzzy-based assessment of groundwater intrinsic vulnerability of a volcanic aquifer in the Chilean Andean Valley.

PubMed

Duhalde, Denisse J; Arumí, José L; Oyarzún, Ricardo A; Rivera, Diego A

2018-06-11

A fuzzy logic approach has been proposed to face the uncertainty caused by sparse data in the assessment of the intrinsic vulnerability of a groundwater system with parametric methods in Las Trancas Valley, Andean Mountain, south-central Chile, a popular touristic place in Chile, but lacking of a centralized drinking and sewage water public systems; this situation is a potentially source of groundwater pollution. Based on DRASTIC, GOD, and EKv and the expert knowledge of the study area, the Mamdani fuzzy approach was generated and the spatial data were processed by ArcGIS. The groundwater system exhibited areas with high, medium, and low intrinsic vulnerability indices. The fuzzy approach results were compared with traditional methods results, which, in general, have shown a good spatial agreement even though significant changes were also identified in the spatial distribution of the indices. The Mamdani logic approach has shown to be a useful and practical tool to assess the intrinsic vulnerability of an aquifer under sparse data conditions.

Inmunoterapias para las adicciones a las drogas Immunotherapies for Drug Addictions

PubMed Central

Montoya, Iván D.

2008-01-01

Immunotherapies in the form of vaccines (active immunization) or monoclonal antibodies (passive immunization) appear safe and a promising treatment approaches for some substance-related disorders. The mechanism of action of the antibody therapy is by preventing the rapid entry of drugs of abuse into the central nervous system. In theory, immunotherapies could have several clinical applications. Monoclonal antibodies may be useful to treat drug overdoses and prevent the neurotoxic effects of drugs by blocking the access of drugs to the brain. Vaccines may help to prevent the development of addiction, initiate drug abstinence in those already addicted to drugs, or prevent drug use relapse by reducing the pharmacological effects and rewarding properties of the drugs of abuse on the brain. Passive immunization with monoclonal antibodies has been investigated for cocaine, methamphetamine, nicotine, and phencyclidine (PCP). Active immunization with vaccines has been studied for cocaine, heroin, methamphetamine, and nicotine. These immunotherapies seem promising therapeutic tools and are at different stages in their development before they can be approved by regulatory agencies for the treatment of substance-related disorders. The purpose of this article is to review the current immunotherapy approaches with emphasis on the risks and benefits for the treatment of these disorders. PMID:18551223

Performance Assessment Institute-NV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lombardo, Joesph

2012-12-31

The National Supercomputing Center for Energy and the Environment’s intention is to purchase a multi-purpose computer cluster in support of the Performance Assessment Institute (PA Institute). The PA Institute will serve as a research consortium located in Las Vegas Nevada with membership that includes: national laboratories, universities, industry partners, and domestic and international governments. This center will provide a one-of-a-kind centralized facility for the accumulation of information for use by Institutions of Higher Learning, the U.S. Government, and Regulatory Agencies and approved users. This initiative will enhance and extend High Performance Computing (HPC) resources in Nevada to support critical nationalmore » and international needs in "scientific confirmation". The PA Institute will be promoted as the leading Modeling, Learning and Research Center worldwide. The program proposes to utilize the existing supercomputing capabilities and alliances of the University of Nevada Las Vegas as a base, and to extend these resource and capabilities through a collaborative relationship with its membership. The PA Institute will provide an academic setting for interactive sharing, learning, mentoring and monitoring of multi-disciplinary performance assessment and performance confirmation information. The role of the PA Institute is to facilitate research, knowledge-increase, and knowledge-sharing among users.« less

Potential drug interactions in patients given antiretroviral therapy.

PubMed

Santos, Wendel Mombaque Dos; Secoli, Silvia Regina; Padoin, Stela Maris de Mello

2016-11-21

to investigate potential drug-drug interactions (PDDI) in patients with HIV infection on antiretroviral therapy. a cross-sectional study was conducted on 161 adults with HIV infection. Clinical, socio demographic, and antiretroviral treatment data were collected. To analyze the potential drug interactions, we used the software Micromedex(r). Statistical analysis was performed by binary logistic regression, with a p-value of ≤0.05 considered statistically significant. of the participants, 52.2% were exposed to potential drug-drug interactions. In total, there were 218 potential drug-drug interactions, of which 79.8% occurred between drugs used for antiretroviral therapy. There was an association between the use of five or more medications and potential drug-drug interactions (p = 0.000) and between the time period of antiretroviral therapy being over six years and potential drug-drug interactions (p < 0.00). The clinical impact was prevalent sedation and cardiotoxicity. the PDDI identified in this study of moderate and higher severity are events that not only affect the therapeutic response leading to toxicity in the central nervous and cardiovascular systems, but also can interfere in tests used for detection of HIV resistance to antiretroviral drugs. investigar potenciais interações droga-droga (PDDI) em pacientes infectados com HIV em terapia de antirretroviral. um estudo de corte transversal foi conduzido em 161 pessoas infectadas com o HIV. Dados de tratamentos clínicos, sociodemográficos e antirretrovirais foram coletados. Para analisar a possível interação medicamentosa, nós usamos o software Micromedex(r). A análise estatística foi feita por regressão logística binária, com um valor P de ≤0.05, considerado estatisticamente significativo. dos participantes, 52.2% foram expostos a potenciais interações droga-droga. No total, houve 218 interações droga-droga, das quais 79.8% ocorreram entre drogas usadas para a terapia antirretroviral. Houve uma associação entre o uso de cinco ou mais medicamentos e possíveis interações droga-droga (p = 0.000), e entre o período de tempo de terapia antirretroviral acima de seis anos e possíveis interações droga-droga (p < 0.00). O impacto clínico foi sedação prevalente e cardiotoxicidade. as PDDI identificadas neste estudo de severidade moderada e superior são eventos que não somente afetam o resultado terapêutico levando a toxicidade nos sistema nervoso central e cardiovascular, mas também podem interferir em testes utilizados para a detecção da resistência do HIV aos medicamentos antirretrovirais. investigar las posibles interacciones fármaco-fármaco (PDDI en inglés) en pacientes con infección por VIH que reciben terapia antirretroviral. un estudio transversal se llevó a cabo en 161 adultos con infección por VIH. Se recogieron datos clínicos, socio demográficos, y de tratamiento antirretroviral. Para analizar las posibles interacciones entre medicamentos, se utilizó el software Micromedex(r). El análisis estadístico se realizó mediante regresión logística binaria, considerando estadísticamente significativo un valor de p de ≤0.05. de todos los participantes, el 52,2% fueron expuestos a posibles interacciones entre fármacos. En total, aparecieron 218 interacciones entre fármacos potenciales, de las que el 79,8% se produjo entre los fármacos utilizados para el tratamiento antirretroviral. Se observó una asociación entre el uso de cinco o más medicamentos y posibles interacciones fármaco-fármaco (p = 0,000) y entre el período de tiempo de la terapia antirretroviral de más de seis años y las posibles interacciones fármaco-fármaco (p <0.00). El impacto clínico fue la sedación prevalente y cardiotoxicidad. las PDDI identificadas en este estudio de gravedad moderada y superior son eventos que no sólo afectan a la respuesta terapéutica con riesgo de toxicidad en el sistema nervioso central y cardiovascular, pero también pueden interferir en las pruebas utilizadas para la detección de la resistencia del VIH a los antirretrovirales.

Characterization of elastase-deficient clinical isolates of Pseudomonas aeruginosa.

PubMed Central

Hamood, A N; Griswold, J; Colmer, J

1996-01-01

Elastase production in Pseudomonas aeruginosa is regulated by the lasR, lasI, rhlR, and rhlI genes. Recently, we have analyzed several clinical isolates of P. aeruginosa for the production of elastase and other extracellular virulence factors. Four of these isolates (CIT1, CIW5, CIW7, and CIW8) produced no elastolytic activity. We have characterized these isolates with respect to their elastase-deficient phenotype. Elastase was detected by immunoblotting experiments using elastase-specific antiserum. We also determined the presence of IasB and IasR mRNAs by Northern (RNA) blot hybridization experiments using lasB and lasR internal probes, respectively. None of the four elastase-deficient strains produced either the elastase protein or the lasB mRNA. Complementation experiments (using plasmids carrying either the lasB or the lasR gene) were conducted to determine if the isolates carry defective lasB or lasR genes. The presence of either a lasB or a lasR plasmid in CIW7 and CIW8 resulted in the production of very low levels of elastase and lasB mRNA. Neither elastase nor lasB mRNA was detected in CIT1 and CIW5 carrying the lasB plasmid. The presence of the lasR plasmid in CIT1 and CIW5 resulted in the production of lasB mRNA and elastase protein in CIW5 only. All elastase-deficient strains produced detectable levels of lasR mRNA which were enhanced in the presence of the lasR plasmid. The Pseudomonas autoinducer (which is encoded by lasI) was also produced by all strains. CIT1 produced both hemolysin and alkaline protease but was defective in pyocyanin production. These results suggest that (i) CIT1 may contain a defect in a lasB-regulatory gene, (ii) CIW5 carries a defect within lasR, and (iii) the defect in isolates CIW7 and CIW8 affects the efficiency of lasB transcription. PMID:8757847

Effects of Candidatus Liberibacter asiaticus on the fitness of the vector Diaphorina citri.

PubMed

Ren, S-L; Li, Y-H; Zhou, Y-T; Xu, W-M; Cuthbertson, A G S; Guo, Y-J; Qiu, B-L

2016-12-01

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama transmits the bacterium 'Candidatus Liberibacter asiaticus' (Las), which causes citrus huanglongbing (HLB) disease. Although many studies have been conducted on the biology of ACP on different host plants, few have taken the plant, Las bacteria and the vector insect within one context to evaluate the effects of Las on the fitness of ACP under field conditions. Understanding the relationship between Las and ACP is critical for both ACP and HLB disease management. We estimated the development and survival of ACP immatures, the longevity and fecundity of ACP female adults in four treatments (Las-positive or -negative ACP on Las-infected and -free citrus plants). Las-positive ACP immatures developed significantly faster on Las-infected citrus than those on Las-free plants. The fecundity and longevity of Las-positive female adults were also greater, or longer on Las-infected citrus shoots, whereas the survival of Las-positive immatures was significantly lower on Las-infected citrus shoots, compared to those that developed on Las-free plants. Similarly, the intrinsic rate of population increase (r m ) was highest (0·1404) when Las-positive ACP fed on Las-infected citrus shoots and the lowest (0·1328) when the Las-negative ACP fed on Las-free citrus shoots. Both the Las infection in ACP and citrus plants had obvious effects on the biology of ACP. When compared to the Las infection in ACP insects, the Las infection in citrus shoots had a more significant effect on the fitness of ACP. To efficiently prevent the occurrence and spread of HLB disease, it is critical to understand the ecological basis of vector outbreaks and disease incidence, especially under field conditions. Thus, this study has increased our understanding of the epidemiology of HLB transmitted by psyllids in nature. © 2016 The Society for Applied Microbiology.

Management of pest mole crickets in Florida and Puerto Rico with a nematode and parasitic wasp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leppla, N.C.; Frank, J.H.; Adjei, M.B.

Non-indigenous invasive mole crickets, Scapteriscus vicinus Scudder (Orthoptera: Gryllotalpidae) in Florida and S. didactylus (Latreille) (the 'changa') in Puerto Rico, are being managed with an entomopathogenic nematode, Steinernema scapterisci (Nguyen and Smart) (Rhabditida: Steinernematidae), and a parasitic wasp, Larra bicolor L. (Hymenoptera: Sphecidae). Pest mole cricket populations have declined by 95% in north central Florida since these specialist natural enemies were released and established in the 1980s. Commercial production of the nematode was initiated, nearly 70 billion were applied in 34 Florida counties, and their establishment, spread, and impact on mole crickets were monitored. The infected mole crickets dispersed themore » nematode rapidly, so that within 6 months these parasites were present in most of the insects trapped in experimental pastures. Three years later, mole cricket populations were reduced to acceptable levels and the bahiagrass had recovered. The nematode was released for the first time in Puerto Rico during 2001 and has persisted; the wasp was introduced in the late 1930s. The geographical distribution of the wasp is being expanded in Florida and Puerto Rico by planting plots of Spermacoce verticillata (L.), a wildflower indigenous to Puerto Rico and widely distributed in southern Florida. Pastures, sod farms, golf courses, landscapes, and vegetable farms in Florida and Puerto Rico are benefiting from biological control of invasive mole crickets. (author) [Spanish] Los grillotopos invasores no indigenas, Scapteriscus vicinus (Orthoptera: Gryllotalpidae) en el estado de Florida y S. didactylus ('changa') en Puerto Rico, estan siendo manejados por el nematodo entomopathogeno, Steinernema scapterisci (Rhabditida: Steinernematidae) y la avispa parasitica, Larra bicolor (Hymenoptera: Sphecidae). Las poblaciones de los grillotopo plagas han declinado un 95% en el norte central de la Florida desde que estos enemigos naturales especialistas fueron liberados y establecidos en los 80s. Consecuentemente, la produccion comercial del nematodo fue iniciada, casi 70 billones fueron aplicados en 34 condados de la Florida, y se realizo un monitoreo para evaluar su establecimiento, dispersion e impacto sobre los grillotopos. Los gillotopos infectados dispersaron los nematodos rapidamente, tanto que despues de 6 meses estos parasitos estaban presentes en la mayoria de los insectos atrapados en los pastos experimentales. Tres anos despues, las poblaciones de los grillotopos fueron reducidas a niveles aceptables y los campos de pasto 'bahia' se recuperaron. El nematodo fue liberado para la primera vez en Puerto Rico durante del 2001 y ha persistido; la avispa fue introducida al final de los 30s. La distribucion geografica de la avispa se esta extendiendo en la Florida y Puerto Rico por medio de la siembra de parcelas de Spermacoce verticillata, una flor silvestre indigena a Puerto Rico y distribuida ampliamente en el sur de la Florida. Los campos de pasto, las operaciones comerciales de cesped, los campos de golf, los paisajes y las fincas de hortalizas en la Florida y Puerto Rico se estan beneficiando del control biologico de los grillotopos invasores. (author)« less

VizieR Online Data Catalog: Star clusters automatically detected in the LMC (Bitsakis+, 2017)

NASA Astrophysics Data System (ADS)

Bitsakis, T.; Bonfini, P.; Gonzalez-Lopezlira, R. A.; Ramirez-Siordia, V. H.; Bruzual, G.; Charlot, S.; Maravelias, G.; Zaritsky, D.

2018-03-01

The archival data used in this work were acquired from several diverse large surveys, which mapped the Magellanic Clouds at various bands. Simons+ (2014AdSpR..53..939S) composed a mosaic using archival data from the Galaxy Evolution Explorer (GALEX) at the near-ultraviolet (NUV) band (λeff=2275Å). The mosaic covers an area of 15deg2 on the LMC. the central ~3x1deg2 of the LMC (the bar-region) was later observed by the Swift Ultraviolet-Optical Telescope (UVOT) Magellanic Clouds Survey (SUMAC; Siegel+ 2014AJ....148..131S). The optical data used here are from the Magellanic Cloud Photometric Survey (MCPS; Zaritsky+ 2004, J/AJ/128/1606). These authors observed the central 64deg2 of the LMC with 3.8-5.2 minute exposures at the Johnson U, B, V, and Gunn i filters of the Las Campanas Swope Telescope. Meixner+ (2006, J/AJ/132/2268) performed a uniform and unbiased imaging survey of the LMC (called Surveying the Agents of a Galaxy's Evolution, or SAGE), covering the central 7deg2 with both the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer (MIPS) on-board the Spitzer Space Telescope. (1 data file).

Tumores neonatales y malformaciones congénitas

PubMed Central

Tornero, O. Berbel; García, J.A. Ortega; Tortajada, J. Ferrís i; Castell, J. García; Colomer, J. Donat i; Soldin, O.P.; Soler, J.L. Fuster

2013-01-01

Introducción La asociación entre tumores y malformaciones congénitas está bien establecida, pero no existen datos exclusivos en el período neonatal y se desconocen los mecanismos subyacentes que generan dicha relación. Objetivos Este trabajo tiene dos objetivos: primero, analizar la frecuencia de los tumores neonatales asociados a malformaciones congénitas, y segundo, comentar las posibles hipótesis etiopatogénicas de la relación entre ambas entidades. Materiales y método Estudio retrospectivo de las historias clínicas de los tumores neonatales, en el Hospital Universitario Materno- Infantil La Fe de Valencia, desde enero de 1990 hasta diciembre de 1999. Selección y descripción de las variedades histológicas asociadas a malformaciones congénitas. Éstas se han agrupado siguiendo los criterios de la Clasificación Internacional de Enfermedades CIE-9, códigos 740.0–759.9. Revisión sistemática bibliográfica de los últimos 25 años, obtenida del Medline, Cancerlit, Index Citation Science y Embase. El perfil de búsqueda utilizado fue la combinación de “neonatal/congenital-tumors/cancer/neoplasms” y “congenital malformations/birth defects”. Resultados Se identificaron 72 tumores neonatales (2,8 % del total de tumores pediátricos diagnosticados en dichos años) y 15 de ellos (20,8 %) asociados a malformaciones congénitas, enfermedades o síndromes congénitos. Las asociaciones entre tumores neonatales y malformaciones congénitas fueron las siguientes: a) angioma en 3 pacientes: con dos cardiopatías congénitas y una atresia de coanas-laringomalacia; b) neuroblastoma en 2 pacientes: uno con riñón en herradura y anomalías vertebrales, y otro con cardiopatía congénita; c) teratoma en 2 pacientes: uno con fisura palatina y anomalías vertebrales, y otro con metatarso varo; d) tumor del sistema nervioso central en un paciente con hernia de Bochdaleck; e) tumor cardíaco en 4 pacientes con esclerosis tuberosa; f) leucemia aguda en un paciente con síndrome de Down y cardiopatía congénita; g) tumor renal en un caso con hidrocefalia triventricular, y h) tumor adrenal en un caso con hemihipertrofia. En la bibliografía específica, las publicaciones engloban tumores de diferentes épocas pediátricas y sin unanimidad de criterios para clasificar las malformaciones congénitas. Apenas existen datos en el período neonatal y la asociación entre ambas entidades se obtiene de registros de instituciones médicas. La prevalencia oscila entre el 15 y el 31,6 %. Las hipótesis etiopatogénicas que explican la asociación entre tumores neonatales y malformaciones congénitas están basadas en las exposiciones prenatales (preconcepcionales y transplacentarias) a factores de riesgo potencialmente mutagénicos y carcinogénicos. Conclusiones Probablemente, los tumores neonatales se asocian con mayor frecuencia a malformaciones congénitas que los tumores diagnosticados en épocas posteriores de la vida. Para conocer la prevalencia real de la asociación entre tumores neonatales y malformaciones congénitas, es necesario unificar los criterios de inclusión y definición de ambas entidades. La obtención de una minuciosa historia medioambiental en todos los tumores neonatales asociados a malformaciones congénitas, donde se detallen y registren todos los factores de riesgo constitucionales y ambientales, es fundamental para mejorar nuestros escasos conocimientos de los mecanismos prenatales subyacentes y avanzar en su prevención. PMID:18559198

Forecasters Handbook for Central America and Adjacent Waters

DTIC Science & Technology

1989-09-01

8217 VoIlo1 de Chiriqui aeasMa~ ODLE Valcain de Agua 0 J.r7ai-a -,f Cs4, Valcari Santa Ania Z4,, jpw SIERRA BE LAS MINAS eNcy Volcari San Miguel, ia Volcan...Nicaragua NICARAGUA % 0.Los Chiles P Colorado beria e. ,he H~gQ& il~a\\~CSPuerto Viejo 183’W 182’W Nicoy APuerto ere0Pndn la Iaz6RA L Lia CARIBBEAN SEA 10’N...34"" . ,’. ’ . , . - Fgr 4.’--.*..*4 . ici".al Shelf off A -- i L’ , i" T i Nic’a• agua • s... .n/ C o.astal St/tm a t .- 3

La EPA aplica un criterio flexible en cuanto a las normas que rigen las plantas eléctricas móviles importadas para usarse en Puerto Rico y las Islas Vírgenes Estadounidenses

EPA Pesticide Factsheets

Comunicado de prensa de la EPA: La EPA aplica un criterio flexible en cuanto a las normas que rigen las plantas eléctricas móviles importadas para usarse en Puerto Rico y las Islas Vírgenes Estadounidenses

Lung transplantation for high-risk patients with idiopathic pulmonary fibrosis.

PubMed

De Oliveira, Nilto C; Julliard, Walker; Osaki, Satoru; Maloney, James D; Cornwell, Richard D; Sonetti, David A; Meyer, Keith C

2016-10-07

Survival for patients with idiopathic pulmonary fibrosis (IPF) and high lung allocation score (LAS) values may be significantly reduced in comparison to those with lower LAS values. To evaluate outcomes for high-risk IPF patients as defined by LAS values ≥46 (N=42) versus recipients with LAS values <46 (N=89). We retrospectively reviewed records of 131 consecutive patients with IPF who received lung transplants at our institution between 1999 and 2013. The mean LAS was significantly higher (59.5, interquartile range 43.9-75.9 vs. 39.3, interquartile range 37.7-44.3; p<0.01) for the high-risk cohort. The higher LAS cohort had significantly lower percent predicted forced vital capacity (FVC) versus recipients with LAS <46 (41.3±14.1% vs. 53.2±16.2%; p<0.01) and required more supplemental oxygen (7±5 vs. 4±2 L/min, p<0.01) prior to transplant versus recipients with LAS <46. Although the incidence of early post-LTX pulmonary complications was increased for the higher LAS group versus recipients with LAS <46, 30-day mortality and actuarial survival did not differ between the two cohorts. Although lung transplantation in patients with IPF and high LAS values is associated with increased risk of early post-transplant complications, long-term post-transplant survival for our high-LAS cohort was equivalent to that for the lower LAS recipients.

Evolution of the long-wavelength, subduction-driven topography of South America since 150 Ma

NASA Astrophysics Data System (ADS)

Flament, N. E.; Gurnis, M.; Williams, S.; Bower, D. J.; Seton, M.; Müller, D.

2014-12-01

Subduction to the west of South America spans 6000 km along strike and has been active for over 250 Myr. The influence of the history of subduction on the geodynamics of South America has been profound, driving mountain building and arc volcanism in the Andean Cordillera. Here, we investigate the long-wavelength changes in the topography of South America associated with subduction and plate motion and their interplay with the lithospheric deformation associated with the opening of the South Atlantic. We pay particular attention to the topographic expression of flat-lying subduction zones. We develop time-dependent geodynamic models of mantle flow and lithosphere deformation to investigate the evolution of South American dynamic and total topography since the late Jurassic (150 Ma). Our models are semi-empirical because the computational cost of fully dynamic, evolutionary models is still prohibitive. We impose the kinematics of global plate reconstructions with deforming continents in forward global mantle convection models with compositionally distinct crust and continental lithosphere embedded within the thermal lithosphere. The shallow thermal structure of subducting slabs is imposed, allowing us to investigate the evolution of dynamic topography around flat slab segments in time-dependent models. Multiple cases are used to investigate how the evolution of South American dynamic topography is influenced by mantle viscosity, the kinematics of the opening of the South Atlantic and alternative scenarios for recent and past flat-slab subduction. We predict that the migration of South America over sinking oceanic lithosphere resulted in continental tilt to the west until ~ 45 Ma, inverting to an eastward tilt thereafter. This first-order result is consistent with the reversal of the drainage of the Amazon River system. We investigate which scenarios of flat-slab subduction since the Eocene are compatible with geological constraints on the evolution of the Solimoes Basin, the Chaco Basin, the Sierras Pampeanas and the Central Patagonian Basin. To broadly constrain mantle viscosity, we compare models to the total subsidence inferred from well data offshore Argentina and Brazil, and to mantle tomography, since the initial and boundary conditions are based on independent plate reconstructions.

Geological evolution of Paniri volcano, Central Andes, northern Chile

NASA Astrophysics Data System (ADS)

Godoy, Benigno; Lazcano, José; Rodríguez, Inés; Martínez, Paula; Parada, Miguel Angel; Le Roux, Petrus; Wilke, Hans-Gerhard; Polanco, Edmundo

2018-07-01

Paniri volcano, in northern Chile, belongs to a volcanic chain trending across the main orientation of the Central Andean volcanic province. Field work mapping, stratigraphic sequences, and one new 40Ar/39Ar and eleven previous published 40Ar/39Ar, and K/Ar ages, indicate that the evolution of Paniri involved eruption of seven volcanic units (Malku, Los Gordos, Las Lenguas, Las Negras, Viscacha, Laguna, and Llareta) during four main stages occurring over more than 1 Myr: Plateau Shield (>800 ka); Main Edifice (800-400 ka); Old Cone (400-250 ka); and New Cone (250-100 ka). Considering glacial and fluvial action, an estimated 85.3 km3 of volcanic material were erupted during the eruptive history of Paniri volcano, giving a bulk eruption rate of 0.061 km3/ka, with major activity in the last 150 kyr (eruption rate of 0.101 km3/ka). Lava flows from Paniri show abundant plagioclase together with subordinate ortho-, and clino-pyroxene, and amphibole as main phenocrysts. Moreover, although true basalts are scarce in the Central Andes, olivine-bearing lavas were erupted at Paniri at ∼400 ka. Also, scarce phenocrysts of biotite, quartz, rutile, and opaque minerals (Fe-Ti oxides) were identified. The groundmass of these flows is composed mainly of glass along with pyroxene and plagioclase microlites. Consolidated and unconsolidated pyroclastic deposits of dacitic composition are also present. The consolidated deposits correspond to vitreous tuffs, whilst unconsolidated deposits are composed of pumice clasts up to 5 cm in diameter. Both pyroclastic deposits are composed of glassy groundmass (up to 80% vol.), and subordinated plagioclase, hornblende, and biotite phenocrysts up to 1 cm in length. Results of twenty-four new, coupled with previous published compositional analyses show that volcanic products of Paniri vary from 57% (basaltic-andesite) to 71% (rhyolite) vol. SiO2, with significant linear correlations between major element-oxide and trace-element concentrations. 87Sr/86Sr isotope ratios range from 0.7070 to 0.7075, indicating that Paniri, similar to other volcanoes of the San Pedro - Linzor volcanic chain, have undergone significant crustal contamination of its parental magmas. However, the almost constant Sr-isotope compositions of the different volcanic units defined for Paniri volcano, suggested later fractional crystallization of magmas at upper crustal levels.

El Administrador Regional de la EPA Pete López se reúne con el Gobernador de las Islas Vírgenes Estadounidenses, Kenneth Mapp, comprometiéndose a restablecer las comunidades de Puerto Rico y las USVI

EPA Pesticide Factsheets

Comunicado de prensa de la EPA: El Administrador Regional de la EPA Pete López se reúne con el Gobernador de las Islas Vírgenes Estadounidenses, Kenneth Mapp, comprometiéndose a restablecer las comunidades de Puerto Rico y las USVI

Modeling and Reduction of Shocks on Electronic Components Within a Projectile

DTIC Science & Technology

2008-08-01

Engineering, University of Nevada, Las Vegas, NV 89154-4027 †Department of Civil and Environmental Engineering, University of Nevada, Las Vegas, NV...Samaan Ladkanyb, Mostafiz Chowdhuryc aDepartment of Mechanical Engineering, University of Nevada, Las Vegas, Las Vegas, NV 89154-4027, USA bDepartment...of Civil and Environmental Engineering, University of Nevada, Las Vegas, Las Vegas, NV 89154-4027, USA cAMSRL-WM-MB (ALC), Ordnance Materials Branch

Las ideologias, las ciencias naturales y sus implicaciones en la educacion cientifica

NASA Astrophysics Data System (ADS)

Lozada Roldan, Sandra

Este estudio ausculto las concepciones epistemologicas de los docentes de ciencia del nivel secundario con relacion a las ideologias y las ciencias naturales. Tambien examino las posiciones de los docentes ante asuntos publicos relacionados a la ciencia. Para propositos de este estudio se diseno y se valido el cuestionario con el cual se obtuvieron los resultados. La investigacion es de tipo cuantitativa y se utilizo como diseno la encuesta. El cuestionario se administro en varias actividades de desarrollo profesional para maestros de ciencia. Un total de 78 maestros del nivel secundario respondieron el cuestionario. Para analizar los datos obtenidos se utilizaron estadisticas descriptivas como la distribucion de frecuencia y el porciento. Ademas se establecieron codigos y categorias para describir las posiciones de los maestros ante asuntos publicos relacionados a la ciencia. Los analisis demostraron que entre los docentes participantes de este estudio prevalecen ciertas concepciones epistemologicas adecuadas acerca de las ciencias naturales, a la luz de la literatura consultada. Entre estas concepciones se destacan las siguientes: a) la filosofia materialista de las ciencias naturales, b) la naturaleza tentativa y constructivista del conocimiento cientifico, c) el uso de una metodologia que garantiza cierto grado de objetividad y con el que se justifican y validan los enunciados cientificos y d) la funcion instrumental del conocimiento cientifico. Sin embargo, entre los docentes participantes de este estudio prevalecen ciertas concepciones epistemologicas erroneas acerca de las ciencias naturales, a la luz de la literatura consultada. Entre estas concepciones se destacan las siguientes: a) tendencia inductivista en el que las teorias cientificas comienzan con observaciones que establecen generalizaciones, b) secuencia jerarquica de la metodologia cientifica. Ademas, entre los docentes participantes de este estudio prevalecen concepciones epistemologicas adecuadas acerca de las ideologias, a la luz de la literatura consultada. Entre estas concepciones se destacan las siguientes: a) la funcion de las ideologias y b) la ausencia de validez ante el conocimiento cientifico. Sin embargo, en cuanto a considerar las ciencias naturales como una ideologia mas conocida como cientificismo, no hubo consistencia en las respuestas de los participantes por lo que no es posible afirmarlo o negarlo. Los hallazgos tambien revelaron que entre los docentes participantes hubo posiciones a favor y en contra para las dos situaciones sobre asuntos publicos relacionados a la ciencia que se presentaron. Estas posiciones fueron justificadas con argumentos cientificos y argumentos ideologicos, entre estos, los morales y los economicos. Con este dato se puede afirmar el uso de las ideologias en asuntos publicos relacionados a la ciencia.

Magnetotellurics applied to the study of the Guaraní aquifer in Entre Ríos Province, N-E Argentina

NASA Astrophysics Data System (ADS)

Favetto, Alicia; Curcio, Ana; Pomposiello, Cristina

2011-07-01

The South American Guaraní Aquifer System covers the entire Parana basin and part of the Chaco-Parana basin. This system is one of the most important groundwater reservoirs; it is shared by four neighboring countries covering an area larger than one million square kilometers. The geological units closely related to the Guaraní Aquifer are the Piramboia and Botucatu Formations that consist of Triassic-Jurassic aeolian, fluvial and lacustrine sandstones, and the Serra Geral basalts with clastic intercalations. Serra Geral, an effusive Cretaceous complex, covers the sandstones and provides a high degree of confinement to the system. This paper presents the interpretation of magnetotelluric (MT) data collected during 2007-2008 in Entre Ríos Province, Argentina. These data, recorded in three profiles, mainly provide the depth to the crystalline basement, determinant for the presence of aquifer-related sediments. Models showed that the discrimination of the basalts strongly depends on local electrical characteristics. Model information is quite consistent with the information from oil and thermal wells located close to the profiles.

Stage-Dependent Expression of Deltamethrin Toxicity and Resistance in Triatoma infestans (Hemiptera: Reduviidae) From Argentina.

PubMed

Germano, Mónica D; Picollo, María I

2018-02-20

Triatoma infestans Klug (Hemiptera: Reduviidae) is the main vector of Chagas disease in Latin America. This insect has been controlled with pyrethroids since the 1980s, although the emergence of resistance to deltamethrin has decreased control success in some areas of the Gran Chaco ecoregion. The response of T. infestans to deltamethrin was evaluated per developmental stage. In addition, we evaluated the possible stage-dependent expression of deltamethrin resistance. The bioassays were conducted by topical application of the insecticide in acetone. The drop size, age at the time of exposure, and mortality measuring time were standardized per stage. The lethal dose of deltamethrin moderately increased with the developmental stage. The resistance to deltamethrin was expressed in every instar, and was the highest in the fourth- and fifth-instar nymphs. While increasing, weight plays a relevant role in lethal dose stage dependency, a number of contributing factors such as degradative metabolism are probably involved in the variability of insecticide effect and resistance described for different T. infestans developmental stages. Possible explanations for these differences and their implications on resistance management and chemical control are discussed.

STS-65 Earth observation of dust plumes from Rio Grande in Southern Bolivia

NASA Technical Reports Server (NTRS)

1994-01-01

STS-65 Earth observation taken aboard Columbia, Orbiter Vehicle (OV) 102, is of dust plumes from the Rio Grande in Southern Bolivia. A series of dust plumes can be seen rising from sand banks in the Rio Grande of southern Bolivia, bottom right of this northeast-looking view. The Rio Grande brings sediment from the Andes (foothills visible in the foreground, bottom left) and flows across the flat country of the northern Chaco plain. During the low-flow season, sand banks of this sediment are exposed to northerly winds which often blow dust into the surrounding forest. One of the significances of the dust plumes is that dust acts as a source of nutrient for the local soils. This is the most impressive example of dust ever recorded on Shuttle photography from this river. Such plumes have been seen on photographs from four previous missions (STS-31, STS-47, STS-48, STS-51I) emanating from the Rio Grande. The plumes are regularly space because the sand is blown only from those reaches of th

Heterogeneities in the Ecoepidemiology of Trypanosoma cruzi Infection in Rural Communities of the Argentinean Chaco

PubMed Central

Cardinal, M. Victoria; Orozco, M. Marcela; Enriquez, Gustavo F.; Ceballos, Leonardo A.; Gaspe, María Sol; Alvarado-Otegui, Julián A.; Gurevitz, Juan M.; Kitron, Uriel; Gürtler, Ricardo E.

2014-01-01

We conducted a cross-sectional survey of Trypanosoma cruzi infection of Triatoma infestans as well as dogs and cats in 327 households from a well-defined rural area in northeastern Argentina to test whether the household distribution of infection differed between local ethnic groups (Tobas and Creoles) and identify risk factors for host infection. Overall prevalence of infection of bugs (27.2%; 95% confidence interval = 25.3–29.3%), dogs (26.0%; 95% confidence interval = 23.3–30.1%), and cats examined (28.7%; 95% confidence interval = 20.2–39.0%) was similar. A multimodel inference approach showed that infection in dogs was associated strongly with the intensity and duration of local exposure to infected bugs and moderately with household ethnic background. Overall, Toba households were at a substantially greater risk of infection than Creole households. The strong heterogeneities in the distribution of bug, dog, and cat infections at household, village, and ethnic group levels may be used for targeted vector and disease control. PMID:24732461

[Phlebotominae: vectors of leishmaniasis in the provinces of Santa Fe and Entre Ríos, Argentina].

PubMed

Salomón, Oscar D; Mocarbel, Nicolás J; Pedroni, Elena; Colombo, Javier; Sandillú, Mónica

2006-01-01

The transmission of tegumentary leishmaniasis (TL) has increased in 9 provinces of Argentina since 1985. Santa Fe and Entre Ríos did not record in this period autochtonous probed cases: however, an epidemic outbreak took place in 2003 in Bella Vista, Corrientes, located in an area with ecological continuity and contiguous to both provinces. In order to evaluate the potential risk of transmission of LT, Phlebotominae were captured at locations close to and southern from Bella Vista during February 2004. The traps located on the shores of Parana river in Santa Fe (El Rabón, Villa Ocampo, Cayastá), and Entre Ríos (La Paz. La Celina-Villa Urquiza) captured 860 individuals of Lutzomyia neivai (99.5%) and Lu. migonei (0.5 %), both species with vectorial capacity for Leishmania (V.) braziliensis. In Tartagal, Santa Fe, the captures were consistent with the residual "chaco" landscape, 7 individuals of Lu. nerivai, Lu. migonei and Lu. cortelezzii. The risk of LT epidemic transmission in these provinces is highlighted, mainly due to the progressive southern tropicalization of the paranaense gallery forest. Clinical and entomological surveillance is recommended.

Cancer incidence and pattern of arsenic concentration in drinking water wells in Córdoba, Argentina.

PubMed

Aballay, Laura Rosana; Díaz, María del Pilar; Francisca, Franco Matías; Muñoz, Sonia Edith

2012-01-01

Cancer occurrence is associated with Arsenic (As) in drinking water. In Argentina, there are high As concentrations in groundwater but there is no published evidence yet of an association between geographic patterns of cancer incidence and the distribution of As in groundwater supplies. The purpose of this study is to assess the association between cancer incidence patterns and As in Córdoba province's aquifers. Age standardized incidence rates (ASIRs) were obtained from Córdoba Cancer Registry (CCR), and As data from official reports of monitoring wells. A multilevel model was applied. Total ASIRs by aquifers for males/females were 191.01/249.22 (Rioja plain); 215.03/225.37 (Pampa hills); and 239.42/188.93 (Chaco-Pampa plain). As was associated with increased risk of colon cancer in women, and lung and bladder cancers in both sexes. It had no association with breast cancer. ASIRs were related to As, controlling for unobserved heterogeneity. An overlapping pattern of higher As and higher risks was evident for lung, bladder and female colon cancers.

Deforestation changes land-atmosphere interactions across South American biomes

NASA Astrophysics Data System (ADS)

Salazar, Alvaro; Katzfey, Jack; Thatcher, Marcus; Syktus, Jozef; Wong, Kenneth; McAlpine, Clive

2016-04-01

South American biomes are increasingly affected by land use/land cover change. However, the climatic impacts of this phenomenon are still not well understood. In this paper, we model vegetation-climate interactions with a focus on four main biomes distributed in four key regions: The Atlantic Forest, the Cerrado, the Dry Chaco, and the Chilean Matorral ecosystems. We applied a three member ensemble climate model simulation for the period 1981-2010 (30 years) at 25 km resolution over the focus regions to quantify the changes in the regional climate resulting from historical deforestation. The results of computed modelling experiments show significant changes in surface fluxes, temperature and moisture in all regions. For instance, simulated temperature changes were stronger in the Cerrado and the Chilean Matorral with an increase of between 0.7 and 1.4 °C. Changes in the hydrological cycle revealed high regional variability. The results showed consistent significant decreases in relative humidity and soil moisture, and increases in potential evapotranspiration across biomes, yet without conclusive changes in precipitation. These impacts were more significant during the dry season, which resulted to be drier and warmer after deforestation.

Estudio comparativo de cúmulos abiertos ricos en estrellas masivas

NASA Astrophysics Data System (ADS)

Baume, G.; Feinstein, A.; Vázquez, R. A.

Los cúmulos abiertos muy jóvenes proveen valiosa información sobre las teorías de evolución estelar. No obstante, no se conoce mucho sobre los miembros mas débiles de estos objetos. Se llevaron a cabo entonces, estudios detallados (fotometría CCD-UBVI y polarimetría) en los cúmulos abiertos: Tr 14, Cr 272, Stok 16, NGC 6231, NGC 3293 y HM 1. Se realizó entonces un análisis comparativo entre ellos y con los objetos Pismis 20 (Vázquez et al. 1995) y NGC 5606 (Vázquez et al. 1994). En particular, se analizó la secuencia principal inferior de los distintos cúmulos, se estudió la extinción interestelar y las propiedades del polvo, se determinaron las correspondientes IMF, y se estudió la forma en que se distribuyen las estrellas menos masivas en relación con las más masivas. Como conclusiones del trabajo se puede decir que se han redeterminado con mayor precisión las distancias y las edades de los objetos bajo estudio, se han hallado varias estrellas con alta probabilidad de estar en fase de contracción y se ha notado una dispersión de edad entre las estrellas más brillantes y las menos brillantes (confirmando la idea de que la formación estelar no es simultánea ni independiente de la masa). Además, se han encontrado que las pendientes de las IMFs de estos objetos son más planas que la de las estrellas de campo y las de cúmulos más evolucionados, siendo comparable con las halladas en objetos jóvenes de la Nube Mayor de Magallanes (Will et al. 1996).

Como Lo Hago Yo: Mielomeningocele En Bolivia

PubMed Central

Dabdoub, Carlos F.; Dabdoub, Carlos B.; Villavicencio, Ramiro; Quevedo, Germán

2014-01-01

Introducción: Las malformaciones del tubo neural (MTN) representan la segunda causa más frecuente de anomalías congénitas, luego de las cardiopatías. En este grupo se destaca el mielomeningocele (MMC) por su mayor incidencia, y por ser la más incapacitante y la más compleja entre todas las demás malformaciones del sistema nervioso c`entral (SNC). En Bolivia, como en muchos países de Sudamérica, los bajos niveles socio-culturales y la debilidad en el sistema sanitario, hacen que su incidencia y su morbilidad, sean mayores que en las naciones más desarrolladas. Material y Métodos: Se realizó un estudio retrospectivo y descriptivo de 70 casos de MMC, atendidos por un equipo multidisciplinario en el Hospital Universitario Japonés (HUJ) de Santa Cruz de la Sierra, entre 2008-2011. De ellos, 60 fueron intervenidos quirúrgicamente. Resultados: Se realizaron controles prenatales sólo en 27 mujeres (38.6%), diagnosticándose una disrafia espinal en apenas dos casos (7.4%). La edad de ingreso del MMC en su mayoría fue después de las 24 horas (65.6%), predominando su localización en la región lumbosacra (64.3%). De ellos, 67.2% eran abiertos, presentando un 32.9% un daño neurológico motor parcial mientras que 47.1% tenían paraplejia por debajo de la lesión. De los 70 casos, tres (4.3%) no fueron intervenidos, por presentar defectos congénitos severos o estado general grave. Las principales complicaciones posoperatorias inmediatas fueron: dehiscencia de sutura y/o infección de la herida (16.6%), fístula de líquido cefalorraquídeo (LCR) (10%) e infección del SNC (11.7%). La mortalidad general y postoperatoria fue de 7.1% y 3.3%, respectivamente. Al mes de vida presentaban hidrocefalia un 80% de los pacientes operados, colocándose una derivación ventriculoperitoneal (DVP) de presión media. De 9 pacientes que tuvieron un acompanamiento de dos o más años, seis presentaron una médula anclada, que fueron intervenidas quirúrgicamente. Conclusión: En esta serie, el diagnóstico prenatal del MMC fue ocasional y la derivación al HUJ de los recién nacidos con esta malformación fue generalmente tardía. No hubo predominio de género y la mayoría de los casos presentaron sus lesiones en la región lumbar y lumbosacra. La mortalidad general y postoperatoria fue similar a la reportada en la literatura. Pocos enfermos realizaron controles posteriores al alta hospitalaria. Igual que otros países de Sudamérica, las falencias en el sistema público de salud y el nivel sociocultural, son factores determinantes para un mal pronóstico en estos niños. Por sus múltiples complicaciones, el MMC requiere de una especial atención gubernamental, sobre todo de carácter preventivo mediante el uso de ácido fólico en mujeres fértiles, como también de un equipo profesional multidisciplinario, a fin de realizar un tratamiento adecuado y oportuno. Al mismo tiempo, trabajos multicéntricos en hospitales de América Latina, ayudarán al mejor manejo de estos pacientes. PMID:24791220

Fate and effects of linear alkylbenzene sulphonates (LAS) in the terrestrial environment.

PubMed

Jensen, J

1999-02-09

Linear alkylbenzene sulphonates (LAS) are a group of anionic surfactants, characterised by having both a hydrophobic and a hydrophilic group. LAS is one of the major ingredients of synthetic detergents and surfactants and is used world-wide for both domestic and industrial applications. LAS is relatively rapidly aerobically degraded, but only very slowly or not at all degraded under anaerobic conditions. Therefore, LAS can be found in very high concentrations in most sewage sludge and enter the soil compartment as a result of sludge application. LAS can be found in elevated concentrations in soil immediately after sludge amendment, but a half-life of approximately 1-3 weeks will generally prevent accumulation in soil and biota. The concentration in soils that have not received sewage sludge recently, is generally less than 1 mg kg-1 and not more than 5 mg LAS kg-1. This is below the lowest concentration of LAS where effects have been observed in the laboratory. The laboratory data is in accordance with field studies using aqueous solutions of the sodium salt of LAS. However, observations of the ecological impact of sewage sludge applications or application of LAS spiked into sludge indicates a lower toxicity of LAS when applied in sludge. On the basis of the information reviewed in this paper, it is concluded that LAS can be found in high concentrations in sewage sludge, but that the relatively rapid aerobic degradation and the reduced bioavailability when applied via sludge, most likely will prevent LAS from posing a threat to terrestrial ecosystems on a long term basis.

Institute of Medicine Early Infant Feeding Recommendations for Childhood Obesity Prevention: Implementation by Immigrant Mothers From Central America.

PubMed

Gaffney, Kathleen F; Brito, Albert V; Kitsantas, Panagiota; Kermer, Deborah A; Pereddo, Graciela; Ramos, Katya M

Describe implementation of Institute of Medicine (IOM) early infant feeding recommendations for child obesity prevention by immigrant mothers from Central America; examine potential relationships with food insecurity and postpartum depressive symptoms. Using a cross-sectional, descriptive design, face-to-face interviews were conducted with 318 mothers of 2month old infants at a large pediatric setting for low income families. Logistic regression models assessed feeding practices, food insecurity and postpartum depressive symptoms. Exclusive breastfeeding rates were low (9.4%); most mothers (62.7%) both breastfed and bottle fed their infants. Mothers who bottle fed at moderate and high intensity were twice as likely to affirm that if you give a baby a bottle, you should always make sure s/he finishes it (OR=2.30, 95% CI=1.13, 4.69; OR=2.29, 95% CI=1.26, 4.14). Food insecurity was experienced by 57% of mothers but postpartum depressive symptoms were low (Possible range=0-30; M=2.96, SD =3.6). However, for each increase in the postpartum depressive symptoms score, the likelihood of affirming a controlling feeding style increased by 11-13%. Immigrant mothers from Central America were more likely to both breastfeed and bottle feed (las dos cosas) than implement exclusive breastfeeding. Bottle feeding intensity was associated with a controlling feeding style. Infant well visits provide the ideal context for promoting IOM recommendations for the prevention of obesity among children of immigrant mothers from Central America. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of Liberibacter infection (huanglongbing or "greening" disease) of citrus on orange juice flavor quality by sensory evaluation.

PubMed

Plotto, Anne; Baldwin, Elizabeth; McCollum, Greg; Manthey, John; Narciso, Jan; Irey, Mike

2010-05-01

Some anecdotal reports suggest that infection of citrus trees with Candidatus Liberibacter asiaticus (Las), the suspected causal agent of huanglongbing (HLB) disease, imparts off flavor to orange juice. It is of interest to the industry to know how Las infection affects juice quality with respect to cultivar, maturity, or processing method. Hamlin, Midsweet, and Valencia oranges were harvested over 2 y from trees that tested negative (Las-) or positive (Las+) for Las from different groves and included normal looking (nonsymptomatic) and symptomatic fruit (small, green, and lopsided) from Las+ trees. In the 1st year, fruit were manually juiced, while in the 2nd year, a commercial process was used. Juice from Las+ trees was compared to juice from Las- trees in difference-from-control tests, and by descriptive analysis. Results showed large variability due to tree, harvest date, and cultivar. Juice from Hamlin Las+ trees tended to be more bitter and sour than its Las- counterpart. In contrast, hand processed Valencia juice from Las+ trees was perceived to have some off-flavor and bitterness compared to control, but the following year, commercially processed Valencia juice from Las+ trees was perceived to be only slightly more sour than juice from Las- trees for the April harvest, and to be sweeter for the June harvest. When juice from individual replicates was pooled to be more representative of a commercial situation, there was no difference between Las+ and Las- juice in Valencia. Trained panel differences were noted for juice from Hamlin Las+ fruit, especially for symptomatic fruit. Assumptions that juice made from oranges harvested from Huanglongbing (from infection with Liberibacter sp.) affected trees is off-flavored appeared to be generally more true for Hamlin juice than for Midsweet or Valencia, especially for Hamlin juice made from symptomatic fruit. For Midsweet and Valencia, flavor differences between juice made from fruit harvested from diseased or healthy trees varied greatly between trees, season, and even processing method. Under a commercial processing situation, where juice is blended from several varieties, seasons, and multiple locations, it is expected that off-flavor will not be a major problem.

Variación temporal de las constantes fundamentales

NASA Astrophysics Data System (ADS)

Landau, S. J.; Vucetich, H.

La variación temporal de las constantes fundamentales es un problema que ha motivado numerosos trabajos teóricos y experimentales desde la hipótesis de los grandes números de Dirac en 1937. Entre los métodos experimentales y observacionales para establecer restricciones sobre la variación de las constantes fundamentes es importante mencionar: comparación entre relojes atómicos[1], métodos geofísicos[2][3], análisis de sistemas de absorción en quasares[4][5][6] y cotas provenientes de la nucleosíntesis primordial[7]. En un trabajo reciente[5], se reportó una significativa variación en la constante de estructura fina. Intentos de unificar las cuatro interacciones fundamentales dieron como resultado teorías con múltiples dimensiones como las teorías de Kaluza-Klein y teorías de supercuerdas. Estas teorías proporcionan un marco teórico natural para el estudio de la variación temporal de las constantes fundamentales. A su vez, un modelo sencillo para estudiar la variación de la constante de estructura fina, fue propuesto en [8], a partir de premisas muy generales como ser covarianza, invarianza de gauge, causalidad y invarianza ante reversiones temporales en el electromagnetismo. Diferentes versiones de las teorías antes mencionadas coinciden en predecir variaciones temporales de las constantes fundamentales pero difieren en la forma de esta variación[9][10]. De esta manera, las restricciones establecidas experimentalmente sobre la variación de las constantes fundamentales pueden ser una herramienta importante para testear estas diferentes teorías. En este trabajo, utilizamos las cotas provenientes de diversas técnicas experimentales, para testear si las mismas son consistentes con alguna de las teorías antes mencionadas. En particular, establecemos cotas sobre la variación de los parámentros libres de las diferentes teorías como por ejemplo el radio de las dimensiones extras en las teorías tipo Kaluza-Klein.

Ecologia de las lombrices de tierra

Treesearch

Grizelle Gonzalez

2014-01-01

De los organismos de suelo, las lombrices de tierra son las mas conocidas y a menudo son consideradas las mas importantes por su influencia en el funcionamiento de ecosistemas de suelo (Hendriz y Bohlen, 2002). Tienen un efecto significativo en la estructura del suelo, el ciclo de nutrimentos y ls productividad de las cosechas. En terminos de biomasa, generalmente...

An EXCEL macro for importing log ASCII standard (LAS) files into EXCEL worksheets

NASA Astrophysics Data System (ADS)

Özkaya, Sait Ismail

1996-02-01

An EXCEL 5.0 macro is presented for converting a LAS text file into an EXCEL worksheet. Although EXCEL has commands for importing text files and parsing text lines, LAS files must be decoded line-by-line because three different delimiters are used to separate fields of differing length. The macro is intended to eliminate manual decoding of LAS version 2.0. LAS is a floppy disk format for storage and transfer of log data as text files. LAS was proposed by the Canadian Well Logging Society. The present EXCEL macro decodes different sections of a LAS file, separates, and places the fields into different columns of an EXCEL worksheet. To import a LAS file into EXCEL without errors, the file must not contain any unrecognized symbols, and the data section must be the last section. The program does not check for the presence of mandatory sections or fields as required by LAS rules. Once a file is incorporated into EXCEL, mandatory sections and fields may be inspected visually.

Fotometría de grupos compactos de galaxias: Shakhbazian 37, 45, 166, 331 y 362

NASA Astrophysics Data System (ADS)

Campos, J. M.; Calderón, J. H.; Gimeno, N. G.; Díaz, R. J.

Continuando con la fotometría CCD de Grupos de Galaxias Compactos de Shakhbazyan (SCGG) en este trabajo se presentan nuevos resultados preliminares sobre los grupos Shakbazyan 37, 45, 166, 331 y 362. EL objeto del proyecto es contribuir al estudio de las propiedades físicas de tales grupos y contribuir a las bases de datos para mejora de las estadísticas. Los datos fueron adquiridos con el Telescopio JKT del Observatorio Norte Europeo. El análisis de las imágenes en las bandas I y B como del índice de color B-I permitió reidentificar las galaxias catalogadas, resultando las mismas muy enrojecidas y verificando que predominan las galaxias tempranas, resultados consistentes con los obtenidos para otros grupos y por otros autores.

Genetic diversity of Candidatus Liberibacter asiaticus based on two hypervariable effector genes in Thailand.

PubMed

Puttamuk, Thamrongjet; Zhou, Lijuan; Thaveechai, Niphone; Zhang, Shouan; Armstrong, Cheryl M; Duan, Yongping

2014-01-01

Huanglongbing (HLB), also known as citrus greening, is one of the most destructive diseases of citrus worldwide. HLB is associated with three species of 'Candidatus Liberibacter' with 'Ca. L. asiaticus' (Las) being the most widely distributed around the world, and the only species detected in Thailand. To understand the genetic diversity of Las bacteria in Thailand, we evaluated two closely-related effector genes, lasAI and lasAII, found within the Las prophages from 239 infected citrus and 55 infected psyllid samples collected from different provinces in Thailand. The results indicated that most of the Las-infected samples collected from Thailand contained at least one prophage sequence with 48.29% containing prophage 1 (FP1), 63.26% containing prophage 2 (FP2), and 19.38% containing both prophages. Interestingly, FP2 was found to be the predominant population in Las-infected citrus samples while Las-infected psyllids contained primarily FP1. The multiple banding patterns that resulted from amplification of lasAI imply extensive variation exists within the full and partial repeat sequence while the single band from lasAII indicates a low amount of variation within the repeat sequence. Phylogenetic analysis of Las-infected samples from 22 provinces in Thailand suggested that the bacterial pathogen may have been introduced to Thailand from China and the Philippines. This is the first report evaluating the genetic variation of a large population of Ca. L. asiaticus infected samples in Thailand using the two effector genes from Las prophage regions.

Estructura orbital en el Problema Restringido Rectilíneo Isósceles

NASA Astrophysics Data System (ADS)

Orellana, R. B.

Para definir problemas en Mecánica Celeste se utilizan diferentes parámetros. El conocimiento de la dinámica del problema para valores particulares de estos parámetros nos permite entender el comportamiento en casos más generales. El Problema Restringido Rectilíneo Isósceles puede ser considerado como el caso límite del Problema de Sitnikov cuando la excentricidad tiende a uno o como el Problema Isósceles cuando la masa central tiende a cero. Se ha compactificado el espacio de fases y analizado la dinámica en el límite. Esto ha permitido separar el espacio de fases en diferentes regiones dependiendo de las clases de órbitas.

[Historical compendium of physical activity and sport].

PubMed

Rodríguez Rodríguez, Luis Pablo

2004-01-01

The Historical Compendium of Physical Activity and Sport analyses, from a scientific perspective, past events in the array of tasks or manoeuvres comprising body movement, in a setting of human liberty and creative capacity. Sport is examined as a result of the evolution of games and in a context of these games. This book contemplates sports, whose selection criteria have included specific features of their individual or team qualities, or combat or opposition characteristics, or those related to their artistic features or to instrumentation or adaptation, or other connotations. 1st authors are 36 professors, from the universities of Barcelona, (Central), Granada, Jaen, Las Palmas de Gran Canaria, León, Madrid (Complutense), Málaga, Murcia, Oviedo, País Vasco, Salamanca, Valencia and Zaragoza.

Earth fissures and localized differential subsidence

USGS Publications Warehouse

Holzer, Thomas L.; Pampeyan, Earl H.

1981-01-01

Long linear tension cracks associated with declining groundwater levels at four sites in subsiding areas in south-central Arizona, Fremont Valley, California, and Las Vegas Valley, Nevada, occur near points of maximum convex-upward curvature in subsidence profiles oriented perpendicular to the cracks. Profiles are based on repeated precise vertical control surveys of lines of closely spaced bench marks. Association of these fissures with zones of localized differential subsidence indicates that linear earth fissures are caused by horizontal tensile strains probably resulting from localized differential compaction. Horizontal tensile strains across the fissures at the point of maximum convex-upward curvature, ranging from approximately 100 to 700 microstrains (0.01 to 0.07% per year), were indicated based on measurements with a tape or electronic distance meter.

MÉXICO Y ESTADO DE GUANAJUATO: TRANSFERENCIAS INTERGENERACIONALES HACIA LOS ADULTOS MAYORES*

PubMed Central

Montes de Oca, Verónica; Hebrero, Mirna

2017-01-01

RESUMEN En México, las transferencias formales e informales destinadas al apoyo de las personas adultas mayores son diversificadas. En este documento se analizan la tendencia nacional y los resultados de un estudio centrado en la entidad federativa de Guanajuato. La distribución de los apoyos confirma que las transferencias hechas por el sistema de seguridad social tienen un sesgo urbano y que las transferencias formales del gobierno federal se orientan a las áreas menos urbanizadas, particularmente las zonas rurales. A pesar de las transferencias formales (esporádicas e insuficientes), las necesidades económicas y de salud de las personas mayores persisten y ello lleva a que sus familiares realicen transferencias informales de naturaleza ascendente. En México —y más concretamente en Guanajuato— el apoyo de quienes residen con la persona mayor tiene un significativo peso, y lo contrario sucede con el de quienes han migrado. A partir de este material, se analiza el rol que, de acuerdo a su cohorte y su condición migratoria, desempeñan los descendientes. En todo caso, queda de manifiesto que, en cada entidad nacional, las dinámicas de transferencias intergeneracionales son de diversos tipos. PMID:29375179

Negative regulation of quorum-sensing systems in Pseudomonas aeruginosa by ATP-dependent Lon protease.

PubMed

Takaya, Akiko; Tabuchi, Fumiaki; Tsuchiya, Hiroko; Isogai, Emiko; Yamamoto, Tomoko

2008-06-01

Lon protease, a member of the ATP-dependent protease family, regulates numerous cellular systems by degrading specific substrates. Here, we demonstrate that Lon is involved in the regulation of quorum-sensing (QS) signaling systems in Pseudomonas aeruginosa, an opportunistic human pathogen. The organism has two acyl-homoserine lactone (HSL)-mediated QS systems, LasR/LasI and RhlR/RhlI. Many reports have demonstrated that these two systems are regulated and interconnected by global regulators. We found that lon-disrupted cells overproduce pyocyanin, the biosynthesis of which depends on the RhlR/RhlI system, and show increased levels of a transcriptional regulator, RhlR. The QS systems are organized hierarchically: the RhlR/RhlI system is subordinate to LasR/LasI. To elucidate the mechanism by which Lon negatively regulates RhlR/RhlI, we examined the effect of lon disruption on the LasR/LasI system. We found that Lon represses the expression of LasR/LasI by degrading LasI, an HSL synthase, leading to negative regulation of the RhlR/RhlI system. RhlR/RhlI was also shown to be regulated by Lon independently of LasR/LasI via regulation of RhlI, an HSL synthase. In view of these findings, it is suggested that Lon protease is a powerful negative regulator of both HSL-mediated QS systems in P. aeruginosa.

Physicochemical determinants of linear alkylbenzene sulfonate (LAS) disposition in skin exposed to aqueous cutting fluid mixtures.

PubMed

Baynes, Ronald E; Brooks, James D; Barlow, Beth M; Riviere, Jim E

2002-06-01

Linear alkylbenzene sulfonate (LAS) is added to cutting fluid formulations to enhance the performance of metal machining operations, but this surfactant can cause contact dermatitis in workers involved in these operations. The purpose of this study was to determine how cutting fluid additives influence dermal disposition of 14C-LAS in mineral oil- or polyethylene glycol 200 (PEG)-based mixtures when topically applied to silastic membranes and porcine skin in an in vitro flow-through diffusion cell system. 14C-LAS mixtures were formulated with three commonly used cutting fluid additives; 0 or 2% triazine (TRI), 0 or 5% triethanolamine (TEA), and 0 or 5% sulfurized ricinoleic acid (SRA). LAS absorption was limited to less than a 0.5% dose and the additives in various combinations influenced the physicochemical characteristics of the dosing mixture. LAS was more likely to partition into the stratum corneum (SC) in mineral oil mixtures, and LAS absorption was significantly greater in the complete mixture. TRI enhanced LAS transport, and the presence of SRA decreased LAS critical micelle concentration (CMC) which reduced LAS monomers available for transport. TEA increased mixture viscosity, and this may have negated the apparent enhancing properties of TRI in several mixtures. In summary, physicochemical interactions in these mixtures influenced availability of LAS for absorption and distribution in skin, and could ultimately influence toxicological responses in skin.

Molecular Insights into the Impact of Oxidative Stress on the Quorum-Sensing Regulator Protein LasR*

PubMed Central

Kafle, Prapti; Amoh, Amanda N.; Reaves, Jocelyn M.; Suneby, Emma G.; Tutunjian, Kathryn A.; Tyson, Reed L.; Schneider, Tanya L.

2016-01-01

The LasR regulator protein functions at the top of the Pseudomonas aeruginosa quorum-sensing hierarchy and is implicated in promoting bacterial virulence. Of note is recent evidence that this transcription factor may also respond to oxidative stress. Here, all cysteines in LasR were inspected to deduce their redox sensitivity and to probe the connection between stress response and LasR activity using purified LasR and individual LasR domains. Cys79 in the ligand binding domain of LasR appears to be important for ligand recognition and folding of this domain to potentiate DNA binding but does not seem to be sensitive to oxidative stress when bound to its native ligand. Two cysteines in the DNA binding domain of LasR do form a disulfide bond when treated with hydrogen peroxide, and formation of this Cys201-Cys203 disulfide bond appears to disrupt the DNA binding activity of the transcription factor. Mutagenesis of either of these cysteines leads to expression of a protein that no longer binds DNA. A cell-based reporter assay linking LasR function with β-galactosidase activity gave results consistent with those obtained with purified LasR. This work provides a possible mechanism for oxidative stress response by LasR and indicates that multiple cysteines within the protein may prove to be useful targets for disabling its activity. PMID:27053110

Fallon, Nevada FORGE Well 21-31 Wireline Logs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blankenship, Doug

Included are the following wireline logs from the Fallon FORGE Well 21-31. Ormat_Forge 21-31_8.5 inch section: FMI data in PDF and DLIS formats; MSCT data in PDF format; Pressure and Temperature data in PDF, LAS, and DLIS formats; Sonic Scanner data in PDF, DLIS, and LAS formats (LAS format contains Stoneley Slowness, Shear Slowness, and Compressional Slowness logs); Triple Combo in PDF, DLIS, and LAS formats; and USIT data in DLIS and PDF formats. Ormat_Forge_21-31_12.25 inch section: Resistivity data in PDF and LAS formats; Sonic Scanner data in PDF, DLIS, and LAS formats (LAS format contains Stoneley Slowness, Shear Slowness,more » and Compressional Slowness logs); Triple Combo in PDF and LAS formats; and Caliper data in PDF format (DLIS format for caliper data is included in the Sonic Scanner DLIS).« less

Genetic Diversity of Candidatus Liberibacter asiaticus Based on Two Hypervariable Effector Genes in Thailand

PubMed Central

Puttamuk, Thamrongjet; Zhou, Lijuan; Thaveechai, Niphone; Zhang, Shouan; Armstrong, Cheryl M.; Duan, Yongping

2014-01-01

Huanglongbing (HLB), also known as citrus greening, is one of the most destructive diseases of citrus worldwide. HLB is associated with three species of ‘Candidatus Liberibacter’ with ‘Ca. L. asiaticus’ (Las) being the most widely distributed around the world, and the only species detected in Thailand. To understand the genetic diversity of Las bacteria in Thailand, we evaluated two closely-related effector genes, lasA I and lasA II, found within the Las prophages from 239 infected citrus and 55 infected psyllid samples collected from different provinces in Thailand. The results indicated that most of the Las-infected samples collected from Thailand contained at least one prophage sequence with 48.29% containing prophage 1 (FP1), 63.26% containing prophage 2 (FP2), and 19.38% containing both prophages. Interestingly, FP2 was found to be the predominant population in Las-infected citrus samples while Las-infected psyllids contained primarily FP1. The multiple banding patterns that resulted from amplification of lasA I imply extensive variation exists within the full and partial repeat sequence while the single band from lasA II indicates a low amount of variation within the repeat sequence. Phylogenetic analysis of Las-infected samples from 22 provinces in Thailand suggested that the bacterial pathogen may have been introduced to Thailand from China and the Philippines. This is the first report evaluating the genetic variation of a large population of Ca. L. asiaticus infected samples in Thailand using the two effector genes from Las prophage regions. PMID:25437428

Blood Pressure, Left Ventricular Geometry, and Systolic Function in Children Exposed to Inorganic Arsenic

PubMed Central

Osorio-Yáñez, Citlalli; Ayllon-Vergara, Julio C.; Arreola-Mendoza, Laura; Aguilar-Madrid, Guadalupe; Hernández-Castellanos, Erika; Sánchez-Peña, Luz C.

2015-01-01

Background: Inorganic arsenic (iAs) is a ubiquitous element present in the groundwater worldwide. Cardiovascular effects related to iAs exposure have been studied extensively in adult populations. Few epidemiological studies have been focused on iAs exposure–related cardiovascular disease in children. Objective: In this study we investigated the association between iAs exposure, blood pressure (BP), and functional and anatomical echocardiographic parameters in children. Methods: A cross-sectional study of 161 children between 3 and 8 years was conducted in Central Mexico. The total concentration of arsenic (As) species in urine (U-tAs) was determined by hydride generation–cryotrapping–atomic absorption spectrometry and lifetime iAs exposure was estimated by multiplying As concentrations measured in drinking water by the duration of water consumption in years (LAsE). BP was measured by standard protocols, and M-mode echocardiographic parameters were determined by ultrasonography. Results: U-tAs concentration and LAsE were significantly associated with diastolic (DBP) and systolic blood pressure (SBP) in multivariable linear regression models: DBP and SBP were 0.013 (95% CI: 0.002, 0.024) and 0.021 (95% CI: 0.004, 0.037) mmHg higher in association with each 1-ng/mL increase in U-tAs (p < 0.025), respectively. Left ventricular mass (LVM) was significantly associated with LAsE [5.5 g higher (95% CI: 0.65, 10.26) in children with LAsE > 620 compared with < 382 μg/L-year; p = 0.03] in an adjusted multivariable model. The systolic function parameters left ventricular ejection fraction (EF) and shortening fraction were 3.67% (95% CI: –7.14, –0.20) and 3.41% (95% CI: –6.44, –0.37) lower, respectively, in children with U-tAs > 70 ng/mL compared with < 35 ng/mL. Conclusion: Early-life exposure to iAs was significantly associated with higher BP and LVM and with lower EF in our study population of Mexican children. Citation: Osorio-Yáñez C, Ayllon-Vergara JC, Arreola-Mendoza L, Aguilar-Madrid G, Hernández-Castellanos E, Sánchez-Peña LC, Del Razo LM. 2015. Blood pressure, left ventricular geometry, and systolic function in children exposed to inorganic arsenic. Environ Health Perspect 123:629–635; http://dx.doi.org/10.1289/ehp.1307327 PMID:25738397

EMPACT: THE LAS VEGAS INTERAGENCY PILOT PROGRAM

EPA Science Inventory

ENPACT: The Las Vegas Interagency Pilot Project

The Las Vegas Interagency Pilot Project of the EMPACT program has involved eleven efforts. These efforts are described in brief on the poster presentation. They include: Las Vegas Environmental Monitoring Inventory, the Qual...

Condiciones Físicas en Nebulosas Gaseosas

NASA Astrophysics Data System (ADS)

Luridiana, V.

1999-03-01

El presente trabajo se ha enfocado a determinar y entender las condiciones físicas en una variedad de objetos nebulares, prestando particular atención al problema de la determinación de las abundancias químicas. Para este fin, hemos utilizado métodos analíticos en algunos casos, y modelos numéricos de fotoionización en otros. El objetivo general del trabajo es proveer de una visión amplia de las herramientas teórico-observacionales que se utilizan para la determinación de la estructura de temperatura y densidad de las regiones fotoionizadas, poniendo en evidencia posibles fuentes de errores sistemáticos y sus consecuencias para la determinación de las abundancias químicas, y proponiendo métodos para corregirlos. Los resultados principales de este trabajo est´n listados a continuación: a) Se discute el problema de la discrepancia entre T(C III) y T(O III) en las nebulosas planetarias, y se muestra como tal discrepancia implica probablemente la presencia de fluctuaciones de temperatura. Debido a que la temperatura de O++ es muy afectada por fluctuaciones de temperatura, se recomienda usar la temperatura de C++ para determinar la abundancia de carbono. b) Presentamos dos nuevos métodos para determinar la temperatura electrónica en nebulosas planetarias, basados en la medición de las intensidades de las líneas de He I. Las temperaturas que se obtienen a partir de estos métodos son menores que aquellas que se obtienen a partir de las líneas de [O III], implicando la presencia de fluctuaciones espaciales de temperatura. Despreciando las fluctuaciones de temperatura, se obtienen valores sesgados de las abundancias químicas. Determinamos las abundancias en las nebulosas planetarias de tipo I de algunos de los elementos más importantes, tomando en cuenta las fluctuaciones de temperatura. c) Presentamos modelos numéricos de las dos regiones H II extragalácticas gigantes NGC 2363 y NGC 5461. Con el modelaje numérico, pretendemos acotar las carácteristicas principales de las nubes ionizadas (distribución espacial del gas, estructura de ionización y de temperatura) y de los cúmulos ionizantes (función inicial de masa, historia de formación estelar, edad). En ambos casos, mostramos que con modelos numéricos calculados para el valor de metalicidad que se determina a partir de la temperatura de [O III], no es posible reproducir el espectro de emisión observado, y que para reproducir las restricciones más robustas es necesario subir la metalicidad de los modelos por un factor de 2. Esto constituye una fuerte indicación en favor de la presencia de fluctuaciones de temperatura. d) Para poder comparar los modelos numéricos con los datos observacionales. mostramos la importancia de corregir las predicciones de los modelos por el sesgo introducido por el tamaío finito de la rendija.

Localization and Distribution of 'Candidatus Liberibacter asiaticus' in Citrus and Periwinkle by Direct Tissue Blot Immuno Assay with an Anti-OmpA Polyclonal Antibody.

PubMed

Ding, Fang; Duan, Yongping; Paul, Cristina; Brlansky, Ronald H; Hartung, John S

2015-01-01

'Candidatus Liberibacter asiaticus' (CaLas), a non-cultured member of the α-proteobacteria, is the causal agent of citrus Huanglongbing (HLB). Due to the difficulties of in vitro culture, antibodies against CaLas have not been widely used in studies of this pathogen. We have used an anti-OmpA polyclonal antibody based direct tissue blot immunoassay to localize CaLas in different citrus tissues and in periwinkle leaves. In citrus petioles, CaLas was unevenly distributed in the phloem sieve tubes, and tended to colonize in phloem sieve tubes on the underside of petioles in preference to the upper side of petioles. Both the leaf abscission zone and the junction of the petiole and leaf midrib had fewer CaLas bacteria compared to the main portions of the petiole and the midribs. Colonies of CaLas in phloem sieve tubes were more frequently found in stems with symptomatic leaves than in stems with asymptomatic leaves with an uneven distribution pattern. In serial sections taken from the receptacle to the peduncle, more CaLas were observed in the peduncle sections adjacent to the stem. In seed, CaLas was located in the seed coat. Many fewer CaLas were found in the roots, as compared to the seeds and petioles when samples were collected from trees with obvious foliar symptoms. The direct tissue blot immuno assay was adapted to whole periwinkle leaves infected by CaLas. The pathogen was distributed throughout the lateral veins and the results were correlated with results of qPCR. Our data provide direct spatial and anatomical information for CaLas in planta. This simple and scalable method may facilitate the future research on the interaction of CaLas and host plant.

Effects of linear alkylbenzene sulfonate (LAS) on the interspecific competition between Microcystis and Scenedesmus.

PubMed

Zhu, Wei; Chen, Huaimin; Guo, Lili; Li, Ming

2016-08-01

The widespread use of detergents increases the concentration of surfactant in lakes and reservoirs. High surfactant loads produces toxicity to algae; however, the influence of the increasing surfactant on the competition between algae is not clear. In this paper, different amounts of linear alkylbenzene sulfonate (LAS) were added to test the effects of LAS on the competition between Microcystis aeruginosa and Scenedesmus obliquus under eutrophic condition. In single culture, the growth of S. obliquus was promoted under lower LAS concentrations (1 and 20 mg L(-1)), but cell density of S. obliquus reduced when treated with higher LAS concentration (100 mg L(-1)). The growth of M. aeruginosa was inhibited markedly with 20 and 100 mg L(-1) LAS. Compared with single culture, the result was opposite in co-cultures and the cell density of S. obliquus increased significantly when treated with LAS of 1, 20, and 100 mg L(-1). The specific growth rates of S. obliquus and M. aeruginosa in both cultures were 0.4-0.5 day(-1) and 0.6-0.7 day(-1), respectively, except that the specific growth rate of M. aeruginosa in both cultures treated with 100 mg L(-1) LAS was about 0.2 day(-1). M. aeruginosa dominated over S. obliquus in the co-culture without LAS, while the competition was completely opposite with the addition of 20 mg L(-1) LAS. The growth of S. obliquus treated with 20 mg L(-1) LAS was not affected significantly in single culture but was promoted by 75 % in co-culture. Moreover, the growth of S. obliquus in co-culture treated with 100 mg L(-1) LAS was promoted by more than 97 %. These results suggested that the increasing LAS would overturn the competition of algae in freshwater ecosystems.

Explicación de las disparidades raciales en la salud neonatal en Brasil*

PubMed Central

Nyarko, Kwame A.; López-Camelo, Jorge; Castilla, Eduardo E.; Wehby, George L.

2015-01-01

Objetivos. Buscamos cuantificar la manera en que los efectos socioeconómicos, demográficos, geográficos y de atención de salud explican las disparidades raciales en las tasas de bajo peso al nacer y prematuridad en Brasil. Métodos. Utilizamos una muestra de 8 949 niños nacidos entre 1995 y el 2009 en 15 ciudades y 7 provincias de Brasil. Nos centramos en las disparidades en la prevalencia de bajo peso al nacer (< 2 500 g) y prematuridad (< 37 semanas de gestación) en recién nacidos de ascendencia solo africana o mezclada con otras ascendencias y de ascendencia solo europea. Usamos un modelo de descomposición para cuantificar la contribución de los factores conceptualmente pertinentes a esas disparidades. Resultados. El modelo permitió explicar entre 45% y 94% de las disparidades en cuanto al bajo peso al nacer y entre 64% y 94% de las disparidades en cuanto a la prematuridad entre los grupos de ascendencia africana y de ascendencia europea. Las diferencias en el uso de atención prenatal y en la ubicación geográfica fueron los factores más importantes, seguidos por las diferencias socioeconómicas. El modelo permitió explicar la mayoría de las disparidades en los recién nacidos de ascendencia africana mezclada y parte de las disparidades en los de ascendencia solo africana. Conclusiones. En las políticas públicas para mejorar la salud infantil se deben abordar las diferencias en cuanto a la atención prenatal y la ubicación geográfica a fin de reducir las disparidades en materia de salud entre los recién nacidos de ascendencia africana y los de ascendencia europea en Brasil.

Influencia atmosférica en la rotación terrestre

NASA Astrophysics Data System (ADS)

Fernández, L. I.; Arias, E. F.; Brunini, C. A.

Las observaciones de los parámetros de la orientación terrestre han alcanzado en estos últimos años una exactitud sin precedentes gracias al uso de modernas técnicas de geodesia espacial. Estudios previos han establecido que las variaciones en la rotación terrestre con períodos iguales o menores que dos años obedecen a cambios en la circulación atmosférica global. Para estos períodos puede comprobarse que existe un gran acuerdo entre las fluctuaciones de la longitud del día (LOD) y los cambios del momento angular atmosférico terrestre (AAM). Sin embargo, no existe un acuerdo general acerca de las causas que provocan las variaciones de largo período de la rotación de la Tierra, también conocidas como ``variaciones decenales''. En nuestro análisis examinamos las correlaciones entre las variaciones de los valores de LOD y las fluctuaciones en la componente polar del momento angular atmosférico terrestre. Con este propósito utilizamos los siguientes juegos de datos: las series de AAM, estimado siguiendo la definición de Barnes et al.(1983) para 2825 días provientes del National Meteorological Center (NMC) y del European Centre for Medium Range Weather Forecast (ECMWF); y las series de LOD que contienen valores alisados espaciados a intervalos de un día elaborados por el International Earth Rotation Service (IERS). Mostraremos que para los cambios anuales e interanuales en la rotación de la Tierra la influencia atmosférica es asombrosa, mientras que, tanto en las escalas temporales más grandes y como en las más pequeñas, ambas series, geodésica y atmosférica, parecen diverger aún cuando poseemos observaciones obtenidas con las técnicas más modernas al presente.

Transmission scenarios of major vector-borne diseases in Colombia, 1990-2016.

PubMed

Padilla, Julio César; Lizarazo, Fredy Eberto; Murillo, Olga Lucía; Mendigaña, Fernando Antonio; Pachón, Edwin; Vera, Mauricio Javier

2017-03-29

Introducción. Las enfermedades transmitidas por vectores representan más de 17 % de todas las enfermedades infecciosas y causan anualmente un millón de defunciones a nivel mundial. En Colombia, la malaria, el dengue, la enfermedad de Chagas y las leishmaniasis son condiciones endemoepidémicas persistentes.Objetivo. Determinar el comportamiento epidemiológico de las enfermedades transmitidas por vectores en zonas urbanas y rurales de Colombia entre 1990 y 2016.Materiales y métodos. Se hizo un estudio descriptivo del comportamiento epidemiológico de las principales enfermedades transmitidas por vectores en zonas urbanas y rurales de Colombia entre 1990 y 2016, con la información proveniente de fuentes oficiales secundarias.Resultados. En el periodo estudiado se registraron 5'360.134 casos de enfermedades transmitidas por vectores, de los cuales 54,7 % fueron de malaria y 24,9 % de dengue. Estos casos concentraron el 80 % de la carga acumulada de casos de enfermedades transmitidas por vectores. Las medianas de las tasas de incidencia fueron 1.371 y 188 por 100.00 habitantes para malaria y dengue, respectivamente. Además, los casos de chikungunya fueron 774.831 desde su introducción en el 2014 y, los de Zika, 117.674 desde su aparición en 2015. En las zonas rurales predominaron las enfermedades parasitarias transmitidas por vectores como la malaria, las leishmaniasis y la enfermedad de Chagas. A nivel urbano, predominaron el dengue, el chikungunya y el Zika.Conclusiones. La transmisión en Colombia de estas enfermedades es persistente en las zonas urbanas y en las rurales, y de tipo endemoepidémico en los casos de malaria, dengue, leishmaniasis y enfermedad de Chagas. Dicha transmisión se ha dado de manera focalizada y con patrones variables de intensidad. Asimismo, se mantienen las condiciones que han favorecido la transmisión emergente de nuevas arbovirosis.

La importancia de la protección de las playas

EPA Pesticide Factsheets

Las playas son una parte importante de la vida en Estados Unidos. Las playas ofrecen un sinnúmero de beneficios para el medio ambiente, actividades recreativas y la economía local. Aprenda la importancia de las playas y cómo protegerlas.

Fate of linear alkylbenzene sulfonate in the Mississippi River

USGS Publications Warehouse

Tabor, C.F.; Barber, L.B.

1996-01-01

The 2 800-km reach of the Mississippi River between Minneapolis, MN, and New Orleans, LA, was examined for the occurrence and fate of linear alkylbenzene sulfonate (LAS), a common anionic surfactant found in municipal sewage effluents. River water and bottom sediment were sampled in the summer and fall of 1991 and in the spring of 1992. LAS was analyzed using solid- phase extraction/derivatization/gas chromatography/mass spectrometry. LAS was present on all bottom sediments at concentrations ranging from 0.01 to 20 mg/kg and was identified in 21% of the water samples at concentrations ranging from 0.1 to 28.2 ??g/L. The results indicate that LAS is a ubiquitous contaminant on Mississippi River bottom sediments and that dissolved LAS is present mainly downstream from the sewage outfalls of major cities. The removal of the higher LAS homologs and external isomers indicates that sorption and biodegradation are the principal processes affecting dissolved LAS. Sorbed LAS appears to degrade slowly.

Bioremediation of surface water co-contaminated with zinc (II) and linear alkylbenzene sulfonates by Spirulina platensis

NASA Astrophysics Data System (ADS)

Meng, Huijuan; Xia, Yunfeng; Chen, Hong

Potential remediation of surface water contaminated with linear alkylbenzene sulfonates (LAS) and zinc (Zn (II)) by sorption on Spirulina platensis was studied using batch techniques. Results show that LAS can be biodegraded by Spirulina platensis, and its biodegradation rate after 5 days was 87%, 80%, and 70.5% when its initial concentration was 0.5, 1, and 2 mg/L, respectively. The maximum Zn (II) uptake capacity of Spirulina platensis was found to be 30.96 mg/g. LAS may enhance the maximum Zn (II) uptake capacity of Spirulina platensis, which can be attributed to an increase in bioavailability due to the presence of LAS. The biodegradation rates of LAS by Spirulina platensis increased with Zn (II) and reached the maximum when Zn (II) was 4 mg/L. The joint toxicity test showed that the combined effect of LAS and Zn (II) was Synergistic. LAS can enhance the biosorption of Zn (II), and reciprocally, Zn (II) can enhance LAS biodegradation.

New rapid methods for determination of total LAS in sewage sludge by high performance liquid chromatography (HPLC) and capillary electrophoresis (CE).

PubMed

Villar, M; Callejón, M; Jiménez, J C; Alonso, E; Guiraúm, A

2009-02-23

Linear alkylbenzene sulfonates (LAS) are the most common synthetic anionic surfactant used in domestic and industrial detergents, with a global production of 2.4x10(6) t year(-1). After use and disposal, LAS may enter the environment by one of the several routes, including by direct discharge to surface water or discharge to water from sewage treatment plants. Sewage treatment plants break down LAS only partly: some of them remain in effluent and other fraction is adsorbed in sewage solid. New and rapid methods for determination of total LAS from sewage sludge based on microwave assisted extraction and HPLC-FL and CE-DAD determination are proposed. The extraction of total LAS is carried out by using microwaves energy, an extraction time of 10 min and 5 mL of methanol. For HPLC-FL determination, mobile phase acetonitrile-water was used, comprising 60% (v/v) from 0 to 1 min and a flow rate of 1 mL min(-1) programmed to 100% acetonitrile between 1 and 2 min and a flow rate of 2 mL min(-1). The final composition was maintained for a further 5 min. The determination of total LAS by CE-DAD was performed in a phosphate buffer (10 mM, pH 9). The separation voltage was 25 kV and the temperature of the capillary was 30 degrees C. Injections were performed in the pressure mode and the injection time was set at 12 s. The determination of total LAS is carried out in less than 5 min. The methods did not require clean-up or preconcentration steps. Detection limit for total LAS in the sludge was 3.03 mg kg(-1) using HPLC-FL and 21.0 mg kg(-1) using CE-DAD, and recoveries were >85% using both determination methods. Concentrations of total LAS obtained using both methods were compared with the sum of concentrations of homologues LAS C-10, LAS C-11, LAS C-12 and LAS C-13 obtained using microwaves assisted extraction and HPLC-FL and CE-DAD determination.

Revision curricular a partir de un analisis comparativo de las discrepancias en los curriculos de una escuela de optometria en Puerto Rico con las competencias requeridas para las agencias de revalida y acreditacion 2004

NASA Astrophysics Data System (ADS)

Rivera Pacheco, Andres

El proposito de esta investigacion, un estudio cualitativo de caso, fue comparar y contrastar el curriculo vigente de la Escuela de Optometria de la UIAPR con las competencias y estandares requeridos por las agencias de acreditacion y de revalida. Con este proposito, decidimos realizar una revision y un analisis de documentos: el prontuario de cada uno de los cursos de los curriculos implantados en el 1993 y en el 2001; las competencias y estandares establecidos por las agencias de revalida y de acreditacion; y las estadisticas en las que se analiza el porcentaje de estudiantes que aprueban cada una de las partes de los examenes de revalida entre el 1998 al 2003. Se realizaron entrevistas dirigidas para dar apoyo y complementar la revision y el analisis de estos documentos. Los participantes de las entrevistas fueron tres estudiantes de la clase de optometria del 2004 (ultima clase del curriculo del 1993); tres estudiantes de la clase de optometria del 2005 (primera clase graduanda del curriculo vigente) y tres profesores y/o directores de los Departamentos de Ciencias Basicas, Ciencias Clinicas y Cuidado al Paciente. Esta investigacion se enmarco en el modelo de evaluacion curricular de discrepancia de Malcolm Provus y en el modelo de desarrollo basado en competencias. Uno de los hallazgos mas importantes del estudio es que los cambios que se implantaron al curriculo del 2001 no han logrado que los estudiantes mejoren su ejecucion en los examenes de revalida. Por otro lado, se encontro que el curriculo vigente atiende completamente los estandares de la practica de Optometria, pero no las competencias. Esta informacion fue validada mediante el uso de una tabla de cotejo para el analisis de los cursos y de la informacion obtenida de las entrevistas. El estudio determina y concluye que existen discrepancias entre los prontuarios de los cursos del curriculo y las competencias requeridas por la agencia de revalida. Segundo, que el Departamento de Ciencias Basicas es el que presenta mas deficiencias en el desarrollo de las competencias. El investigador recomienda disenar e implantar un curriculo basado en competencias y proveer formacion en didactica y procesos de aprendizaje a los profesores.

Image Processing of Digital Cartographic Data.

DTIC Science & Technology

1982-02-05

calidad coma exactitud en la produccio’n de mapas y cartas ha pasada a ser una de las mayares preocupacianes del cart6grafo. En esta ponencia se... calidad y exact itud de la infarmaci6n digital sabre elevacia’n y accidentes artificiales. Se exponen claramente las ventajas y desventajas de las...sambreada) y a las t~cnicas de cantral de calidad relativas al realce de las imfigenes. ABSTRACT FOR SCIENTIFIC PAPER TO BE PRESENTED AT: XII GENERAL

Prediction of Lateral Ankle Sprains in Football Players Based on Clinical Tests and Body Mass Index.

PubMed

Gribble, Phillip A; Terada, Masafumi; Beard, Megan Q; Kosik, Kyle B; Lepley, Adam S; McCann, Ryan S; Pietrosimone, Brian G; Thomas, Abbey C

2016-02-01

The lateral ankle sprain (LAS) is the most common injury suffered in sports, especially in football. While suggested in some studies, a predictive role of clinical tests for LAS has not been established. To determine which clinical tests, focused on potentially modifiable factors of movement patterns and body mass index (BMI), could best demonstrate risk of LAS among high school and collegiate football players. Case-control study; Level of evidence, 3. A total of 539 high school and collegiate football players were evaluated during the preseason with the Star Excursion Balance Test (SEBT) and Functional Movement Screen as well as BMI. Results were compared between players who did and did not suffer an LAS during the season. Logistic regression analyses and calculated odds ratios were used to determine which measures predicted risk of LAS. The LAS group performed worse on the SEBT-anterior reaching direction (SEBT-ANT) and had higher BMI as compared with the noninjured group (P < .001). The strongest prediction models corresponded with the SEBT-ANT. Low performance on the SEBT-ANT predicted a risk of LAS in football players. BMI was also significantly higher in football players who sustained an LAS. Identifying clinical tools for successful LAS injury risk prediction will be a critical step toward the creation of effective prevention programs to reduce risk of sustaining an LAS during participation in football. © 2015 The Author(s).

Catálogo de Radio-Fuentes Opticas con Astrolabio Fotoeléctrico PAII

NASA Astrophysics Data System (ADS)

Manrique, W. T.; Podestá, R. C.; Alonso, E.; Actis, E. V.; Pacheco, A. M.; Bustos, G.; Lizhi, L.; Zezhi, W.; Fanmiao, Z.; Hongqi, W.; Perdomo, R.

Usando los datos observados en San Juan con el Astrolabio Fotoeléctrico PAII desde Febrero de 1992 hasta Marzo de 1997, se ha realizado el Catálogo de Radio-Fuentes Opticas de San Juan conteniendo 69 estrellas. Las observaciones de las posiciones de las radio-fuentes están realizadas para la época y equinoccio J2000,0 y en un sistema cercano al del FK5. Las precisiones medias son ± 2,2 ms y ± 0,"035 en ascensión recta y declinación respectivamente. Las magnitudes de las estrellas son desde 0,9 a 10,7 . Las declinaciones son desde --2,5 grados a --60 grados. La época media es 1995,1. Se muestran también los resultados comparados con el Catálogo Hiparcos.

Double lung transplants have significantly improved survival compared with single lung transplants in high lung allocation score patients.

PubMed

Black, Matthew C; Trivedi, Jaimin; Schumer, Erin M; Bousamra, Michael; van Berkel, Victor

2014-11-01

Historically, double lung transplantation survival rates are higher than those of single lung transplantation, but in critically ill patients a single lung transplant, with less associated operative morbidity, could afford a better outcome. This article evaluates how survival is affected in patients who have a high lung allocation score (LAS) and receive a single versus a double lung transplant. The UNOS Thoracic Transplant Database for lung transplants from January 2005 to June 2012 was used for analysis. Propensity matching was used to minimize differences between the high and low LAS groups and between single and double lung transplants in the high LAS group. Within this database, there were 8,778 patients, of whom 8,050 had an LAS less than 75 and 728 had an LAS greater than or equal to 75. Kaplan-Meier survival curves stratified by high and low LAS, and by single versus double lung transplants, showed a marked decrease in survival (p<0.001) in those with a high LAS who received a single lung transplant when compared with those with a high LAS who received a double lung transplant. This was a much greater difference in survival than was present in the low LAS patient population. Despite a higher operative morbidity, patients who had a high LAS did substantially better in terms of survival if two lungs were transplanted rather than only one, with a larger difference in survival than for patients with a lower LAS. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

40 CFR 81.80 - Las Vegas Intrastate Air Quality Control Region.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Las Vegas Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.80 Las Vegas Intrastate Air Quality Control Region. The Las Vegas Intrastate...

Calidad del aire interior en las escuelas

EPA Pesticide Factsheets

EPA ha desarrollado el Programa de Herramientas de Calidad del Aire Interior para las Escuelas para reducir la exposición a los contaminantes ambientales en las mismas a través de la adopción voluntaria de las prácticas para manejar la calidad del aire int

LAS - LAND ANALYSIS SYSTEM, VERSION 5.0

NASA Technical Reports Server (NTRS)

Pease, P. B.

1994-01-01

The Land Analysis System (LAS) is an image analysis system designed to manipulate and analyze digital data in raster format and provide the user with a wide spectrum of functions and statistical tools for analysis. LAS offers these features under VMS with optional image display capabilities for IVAS and other display devices as well as the X-Windows environment. LAS provides a flexible framework for algorithm development as well as for the processing and analysis of image data. Users may choose between mouse-driven commands or the traditional command line input mode. LAS functions include supervised and unsupervised image classification, film product generation, geometric registration, image repair, radiometric correction and image statistical analysis. Data files accepted by LAS include formats such as Multi-Spectral Scanner (MSS), Thematic Mapper (TM) and Advanced Very High Resolution Radiometer (AVHRR). The enhanced geometric registration package now includes both image to image and map to map transformations. The over 200 LAS functions fall into image processing scenario categories which include: arithmetic and logical functions, data transformations, fourier transforms, geometric registration, hard copy output, image restoration, intensity transformation, multispectral and statistical analysis, file transfer, tape profiling and file management among others. Internal improvements to the LAS code have eliminated the VAX VMS dependencies and improved overall system performance. The maximum LAS image size has been increased to 20,000 lines by 20,000 samples with a maximum of 256 bands per image. The catalog management system used in earlier versions of LAS has been replaced by a more streamlined and maintenance-free method of file management. This system is not dependent on VAX/VMS and relies on file naming conventions alone to allow the use of identical LAS file names on different operating systems. While the LAS code has been improved, the original capabilities of the system have been preserved. These include maintaining associated image history, session logging, and batch, asynchronous and interactive mode of operation. The LAS application programs are integrated under version 4.1 of an interface called the Transportable Applications Executive (TAE). TAE 4.1 has four modes of user interaction: menu, direct command, tutor (or help), and dynamic tutor. In addition TAE 4.1 allows the operation of LAS functions using mouse-driven commands under the TAE-Facelift environment provided with TAE 4.1. These modes of operation allow users, from the beginner to the expert, to exercise specific application options. LAS is written in C-language and FORTRAN 77 for use with DEC VAX computers running VMS with approximately 16Mb of physical memory. This program runs under TAE 4.1. Since TAE 4.1 is not a current version of TAE, TAE 4.1 is included within the LAS distribution. Approximately 130,000 blocks (65Mb) of disk storage space are necessary to store the source code and files generated by the installation procedure for LAS and 44,000 blocks (22Mb) of disk storage space are necessary for TAE 4.1 installation. The only other dependencies for LAS are the subroutine libraries for the specific display device(s) that will be used with LAS/DMS (e.g. X-Windows and/or IVAS). The standard distribution medium for LAS is a set of two 9track 6250 BPI magnetic tapes in DEC VAX BACKUP format. It is also available on a set of two TK50 tape cartridges in DEC VAX BACKUP format. This program was developed in 1986 and last updated in 1992.

Witnessing the Formation of a Brightest Cluster Galaxy in a Nearby X-ray Cluster

NASA Astrophysics Data System (ADS)

Rasmussen, Jesper; Mulchaey, John S.; Bai, Lei; Ponman, Trevor J.; Raychaudhury, Somak; Dariush, Ali

2010-07-01

The central dominant galaxies in galaxy clusters constitute the most massive and luminous galaxies in the universe. Despite this, the formation of these brightest cluster galaxies (BCGs) and the impact of this on the surrounding cluster environment remain poorly understood. Here we present multiwavelength observations of the nearby poor X-ray cluster MZ 10451, in which both processes can be studied in unprecedented detail. Chandra observations of the intracluster medium (ICM) in the cluster core, which harbors two optically bright early-type galaxies in the process of merging, show that the system has retained a cool core and a central metal excess. This suggests that any merger-induced ICM heating and mixing remain modest at this stage. Tidally stripped stars seen around either galaxy likely represent an emerging intracluster light component, and the central ICM abundance enhancement may have a prominent contribution from in situ enrichment provided by these stars. The smaller of the merging galaxies shows evidence for having retained a hot gas halo, along with tentative evidence for some obscured star formation, suggesting that not all BCG major mergers at low redshift are completely dissipationless. Both galaxies are slightly offset from the peak of the ICM emission, with all three lying on an axis that roughly coincides with the large-scale elongation of the ICM. Our data are consistent with a picture in which central BCGs are built up by mergers close to the cluster core, by galaxies infalling on radial orbits aligned with the cosmological filaments feeding the cluster. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

Chlorine-36 in groundwater of the United States: empirical data

NASA Astrophysics Data System (ADS)

Davis, Stanley; Moysey, Stephen; Cecil, DeWayne; Zreda, Marek

2002-11-01

Natural production of the radionuclide chlorine-36 (36Cl) has provided a valuable tracer for groundwater studies. The nuclear industry, especially the testing of thermonuclear weapons, has also produced large amounts of 36Cl that can be detected in many samples of groundwater. In order to be most useful in hydrologic studies, the natural production prior to 1952 should be distinguished from more recent artificial sources. The object of this study was to reconstruct the probable preanthropogenic levels of 36Cl in groundwater in the United States. Although significant local variations exist, they are superimposed on a broad regional pattern of 36Cl/Cl ratios in the United States. Owing to the influence of atmospherically transported ocean salt, natural ratios of 36Cl/total Cl are lowest near the coast and increase to a maximum in the central Rocky Mountains of the United States. Résumé. La production naturelle du radionucléide chlore-36 (36Cl) fournit un intéressant traceur pour l'étude des eaux souterraines. L'industrie nucléaire, en particulier les essais de bombes thermonucléaires, a également produit de grandes quantités de 36Cl qui a pu être détecté dans de nombreux échantillons d'eau souterraine. Afin d'en améliorer l'usage dans les études hydrologiques, la production naturelle avant 1952 doit être distinguée des sources artificielles plus récentes. L'objectif de cette étude a été la reconstruction des niveaux probables de 36Cl dans les eaux souterraines des États-Unis, avant la production anthropique du 36Cl. Bien qu'il existe des variations locales significatives, elles se surimposent à un canevas régional de rapports 36Cl/Cl dans les États-Unis. Du fait de l'influence du sel océanique transporté dans l'atmosphère, les rapports naturels de 36Cl/Cl total sont plus faibles près de la côte et augmentent jusqu'à un maximum dans les Montagnes Rocheuses centrales des États-Unis. Resumen. La producción natural del radionucleido cloro-36 (36Cl) representa un trazador valioso para estudios de hidrogeología. La industria nuclear, sobretodo por los ensayos con armas nucleares, también ha producido grandes cantidades de 36Cl que pueden ser detectadas en muchas muestras de aguas subterráneas. Para que sean lo más útiles posible en estudios hidrológicos, la producción natural anterior al año 1952 debe ser diferenciada de la procedente de fuentes artificiales más recientes. El objeto de este estudio era la reconstrucción de los niveles probables de 36Cl en las aguas subterráneas de los Estados Unidos de América con anterioridad a las aportaciones de origen antrópico. Aunque existen variaciones locales significativas, éstas se superponen a un extenso patrón regional de la relación 36Cl/Cl en el país. Debido a la influencia de la sal transportada en los aerosoles marinos, las proporciones naturales de 36Cl/Cl total son menores cerca de la costa, y alcanzan su máximo en el centro de las Montañas Rocosas.

40 CFR 81.80 - Las Vegas Intrastate Air Quality Control Region.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Quality Control Regions § 81.80 Las Vegas Intrastate Air Quality Control Region. The Las Vegas Intrastate Air Quality Control Region (Nevada) has been revised to consist of the territorial area encompassed by... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Las Vegas Intrastate Air Quality...

40 CFR 81.80 - Las Vegas Intrastate Air Quality Control Region.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Quality Control Regions § 81.80 Las Vegas Intrastate Air Quality Control Region. The Las Vegas Intrastate Air Quality Control Region (Nevada) has been revised to consist of the territorial area encompassed by... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Las Vegas Intrastate Air Quality...

LANDSCAPE CHANGE OF THE LAS VEGAS VALLEY, 1972 TO 1998

EPA Science Inventory

Las Vegas has become one of the fastest growing metropolitan areas in the United States. The cities population has doubled from 1980 to 1994 and in 1995 Las Vegas has surpassed the one million mark. The population of Las Vegas is currently growing at a rate of 7 percent annually....

Enzymatic Depilation of Animal Hide: Identification of Elastase (LasB) from Pseudomonas aeruginosa MCM B-327 as a Depilating Protease

PubMed Central

Pandeeti, Emmanuel Vijay Paul; Pitchika, Gopi Krishna; Jotshi, Jyotsna; Nilegaonkar, Smita S.; Kanekar, Pradnya P.; Siddavattam, Dayananda

2011-01-01

Conventional leather processing involving depilation of animal hide by lime and sulphide treatment generates considerable amounts of chemical waste causing severe environmental pollution. Enzymatic depilation is an environmentally friendly process and has been considered to be a viable alternative to the chemical depilation process. We isolated an extracellular protease from Pseudomonas aeruginosa strain MCM B-327 with high depilation activity using buffalo hide as a substrate. This 33 kDa protease generated a peptide mass fingerprint and de novo sequence that matched perfectly with LasB (elastase), of Pseudomonas aeruginosa. In support of this data a lasB mutant of MCM B-327 strain lacked depilatory activity and failed to produce LasB. LasB heterologously over-produced and purified from Escherichia coli also exhibited high depilating activity. Moreover, reintroduction of the lasB gene to the P. aeruginosa lasB mutant via a knock-in strategy also successfully restored depilation activity thus confirming the role of LasB as the depilating enzyme. PMID:21347249

La edad de las familias Eos, Themis y Koronis

NASA Astrophysics Data System (ADS)

Gil-Hutton, R.

Las familias de asteroides son el producto de la disrupción colisional de objetos destruídos por impactos ocurridos en el cinturón principal. Las colisiones posteriores han modificado los tamaños y las órbitas de los miembros de estas familias, por lo que las distribuciones que vemos hoy en día pueden ser muy diferentes de aquellas producidas inmediatamente después de la fragmentación del objeto original. En esta hipótesis, puede ser difícil reconstruir la evolución colisional de la familia basándose sólo en las actuales distribuciones y puede ser necesario hacer ciertas suposiciones para obtener información sobre las condiciones iniciales. En este trabajo se deriva una estimación de la edad de las familias Eos, Themis y Koronis obtenida de una simulación de la evolución colisional de un cuerpo original teórico para cada familia usando un modelo de distribución para el cinturón propuesto por Gil-Hutton (1996).

Geohydrologic and water-quality characterization of a fractured-bedrock test hole in an area of Marcellus shale gas development, Bradford County, Pennsylvania

USGS Publications Warehouse

Risser, Dennis W.; Williams, John H.; Hand, Kristen L.; Behr, Rose-Anna; Markowski, Antonette K.

2013-01-01

Open-File Miscellaneous Investigation 13–01.1 presents the results of geohydrologic investigations on a 1,664-foot-deep core hole drilled in the Bradford County part of the Gleason 7.5-minute quadrangle in north-central Pennsylvania. In the text, the authors discuss their methods of investigation, summarize physical and analytical results, and place those results in context. Four appendices include (1) a full description of the core in an Excel worksheet; (2) water-quality and core-isotope analytical results in Excel workbooks; (3) geophysical logs in LAS and PDF files, and an Excel workbook containing attitudes of bedding and fractures calculated from televiewer logs; and (4) MP4 clips from the downhole video at selected horizons.

Repertoire of novel sequence signatures for the detection of Candidatus Liberibacter asiaticus by quantitative real-time PCR

PubMed Central

2014-01-01

Background Huanglongbing (HLB) or citrus greening is a devastating disease of citrus. The gram-negative bacterium Candidatus Liberibacter asiaticus (Las) belonging to the α-proteobacteria is responsible for HLB in North America as well as in Asia. Currently, there is no cure for this disease. Early detection and quarantine of Las-infected trees are important management strategies used to prevent HLB from invading HLB-free citrus producing regions. Quantitative real-time PCR (qRT-PCR) based molecular diagnostic assays have been routinely used in the detection and diagnosis of Las. The oligonucleotide primer pairs based on conserved genes or regions, which include 16S rDNA and the β-operon, have been widely employed in the detection of Las by qRT-PCR. The availability of whole genome sequence of Las now allows the design of primers beyond the conserved regions for the detection of Las explicitly. Results We took a complimentary approach by systematically screening the genes in a genome-wide fashion, to identify the unique signatures that are only present in Las by an exhaustive sequence based similarity search against the nucleotide sequence database. Our search resulted in 34 probable unique signatures. Furthermore, by designing the primer pair specific to the identified signatures, we showed that most of our primer sets are able to detect Las from the infected plant and psyllid materials collected from the USA and China by qRT-PCR. Overall, 18 primer pairs of the 34 are found to be highly specific to Las with no cross reactivity to the closely related species Ca. L. americanus (Lam) and Ca. L. africanus (Laf). Conclusions We have designed qRT-PCR primers based on Las specific genes. Among them, 18 are suitable for the detection of Las from Las-infected plant and psyllid samples. The repertoire of primers that we have developed and characterized in this study enhanced the qRT-PCR based molecular diagnosis of HLB. PMID:24533511

Localization and Distribution of 'Candidatus Liberibacter asiaticus’ in Citrus and Periwinkle by Direct Tissue Blot Immuno Assay with an Anti-OmpA Polyclonal Antibody

PubMed Central

Ding, Fang; Duan, Yongping; Paul, Cristina; Brlansky, Ronald H.; Hartung, John S.

2015-01-01

‘Candidatus Liberibacter asiaticus’ (CaLas), a non-cultured member of the α-proteobacteria, is the causal agent of citrus Huanglongbing (HLB). Due to the difficulties of in vitro culture, antibodies against CaLas have not been widely used in studies of this pathogen. We have used an anti-OmpA polyclonal antibody based direct tissue blot immunoassay to localize CaLas in different citrus tissues and in periwinkle leaves. In citrus petioles, CaLas was unevenly distributed in the phloem sieve tubes, and tended to colonize in phloem sieve tubes on the underside of petioles in preference to the upper side of petioles. Both the leaf abscission zone and the junction of the petiole and leaf midrib had fewer CaLas bacteria compared to the main portions of the petiole and the midribs. Colonies of CaLas in phloem sieve tubes were more frequently found in stems with symptomatic leaves than in stems with asymptomatic leaves with an uneven distribution pattern. In serial sections taken from the receptacle to the peduncle, more CaLas were observed in the peduncle sections adjacent to the stem. In seed, CaLas was located in the seed coat. Many fewer CaLas were found in the roots, as compared to the seeds and petioles when samples were collected from trees with obvious foliar symptoms. The direct tissue blot immuno assay was adapted to whole periwinkle leaves infected by CaLas. The pathogen was distributed throughout the lateral veins and the results were correlated with results of qPCR. Our data provide direct spatial and anatomical information for CaLas in planta. This simple and scalable method may facilitate the future research on the interaction of CaLas and host plant. PMID:25946013

Modelo de accesibilidad de conceptos matematicos aplicados en el curso de Astronomia Descriptiva para estudiantes con impedimentos visuales en la UPR

NASA Astrophysics Data System (ADS)

Isidro Villamizar, Gloria Maria

Este estudio utiliza metodologia de investigacion cualitativa, con el proposito de describir, analizar y evaluar los procesos de diseno y desarrollo de un modelo de accesibilidad que consiste en estrategias de ensenanza de las matematicas para estudiantes con impedimentos visuales matriculados en el curso de Astronomia Descriptiva en la UPR. Se utilizaron las siguientes estrategias para recopilar la informacion, 1) reflexiones de la investigadora en el proceso de diseno y desarrollo de las lecciones adaptadas, que se registraron en un diario reflexivo. 2) entrevista semiestructurada luego de haber trabajado las lecciones de aprendizaje adaptadas con los participantes. 3) observaciones y notas de la investigadora del trabajo de los participantes. Para obtener la informacion de los participantes se obtuvo los permisos institucionales necesarios; se seleccionaron los participantes y se validaron los instrumentos; se realizo el desarrollo de las lecciones adaptadas con los participantes; y finalmente, se analizo la informacion obtenida. El diseno de las lecciones de aprendizaje adaptadas se hizo siguiendo las recomendaciones curriculares de los temas de matematicas aplicados en el curso de Astronomia Descriptiva realizado por la investigadora durante su semestre de internado. El testimonio de las voces de los participantes se obtuvo del proceso de desarrollo de las lecciones de aprendizaje adaptadas de temas seleccionados de conceptos matematicos requeridos en el curso de Astronomia Descriptiva y de la entrevista semiestructurada con los participantes, luego de haber trabajado las lecciones de aprendizaje. Para el desarrollo de las lecciones de aprendizaje, se utilizaron materiales tactiles adaptados, materiales tactiles disenados y materiales disponibles comercialmente. Los textos de las lecciones se imprimieron en tinta y en Braille. Se exhorta a disenar y desarrollar estrategias de ensenanza accesibles, considerando como recursos para evaluar su efectividad a personas con impedimentos visuales. El utilizar estrategias de aprendizaje accesibles de acuerdo a las necesidades individuales de los estudiantes, contribuye para que los estudiantes con impedimentos visuales descubran, exploren, investiguen y formulen sus propias conclusiones durante su proceso de aprendizaje.

Fate and transport of linear alkylbenzenesulfonate in a sewage- contaminated aquifer: A comparison of natural-gradient pulsed tracer tests

USGS Publications Warehouse

Krueger, C.J.; Barber, L.B.; Metge, D.W.; Field, J.A.

1998-01-01

Two natural-gradient tracer tests were conducted to determine the transport and biodegradation behavior of linear alkylbenzenesulfonate (LAS) surfactant under in situ conditions in a sewage-contaminated aquifer. The tests were conducted in two biogeochemically distinct zones of the aquifer: (1) an aerobic uncontaminated zone (oxic zone) and (2) a moderately aerobic, sewage-contaminated zone (transition zone). Chromatographic separation of the surfactant mixture was observed in both zones and attributed to the retardation of the longer alkyl chain homologues during transport. No significant loss of IAS mass was observed for the oxic zone while 20% of the LAS mass injected into the transition zone was removed due to biodegradation. Biodegradation preferentially removed the longer alkyl chain homologues and the external isomers (i.e., 2- and 3-phenyl). The removal of LAS mass coincided with a decrease in dissolved oxygen concentrations, the appearance of LAS metabolites, and an increase in the number of free-living bacteria with a concomitant change in bacteria morphology. The formation of LAS metabolites accounted for 86% of the LAS mass removed in the transition zone. Over the duration of the test, sorption and biodegradation enriched the LAS mixture in the more water-soluble and biologically resistant components.Two natural-gradient tracer tests were conducted to determine the transport and biodegradation behavior of linear alkylbenzenesulfonate (LAS) surfactant under in situ conditions in a sewage-contaminated aquifer. The tests were conducted in two biogeochemically distinct zones of the aquifer: (1) an aerobic uncontaminated zone (oxic zone) and (2) a moderately aerobic, sewage-contaminated zone (transition zone). Chromatographic separation of the surfactant mixture was observed in both zones and attributed to the retardation of the longer alkyl chain homologues during transport. No significant loss of LAS mass was observed for the oxic zone while 20% of the LAS mass injected into the transition zone was removed due to biodegradation. Biodegradation preferentially removed the longer alkyl chain homologues and the external isomers (i.e., 2- and 3-phenyl). The removal of LAS mass coincided with a decrease in dissolved oxygen concentrations, the appearance of LAS metabolites, and an increase in the number of free-living bacteria with a concomitant change in bacteria morphology. The formation of LAS metabolites accounted for 86% of the LAS mass removed in the transition zone. Over the duration of the test, sorption and biodegradation enriched the LAS mixture in the more water-soluble and biologically resistant components.

Radiocarbon dating of dissolved inorganic carbon in groundwater from confined parts of the Upper Floridan aquifer, Florida, USA

NASA Astrophysics Data System (ADS)

Plummer, Niel; Sprinkle, Craig

2001-03-01

Geochemical reaction models were evaluated to improve radiocarbon dating of dissolved inorganic carbon (DIC) in groundwater from confined parts of the Upper Floridan aquifer in central and northeastern Florida, USA. The predominant geochemical reactions affecting the 14C activity of DIC include (1) dissolution of dolomite and anhydrite with calcite precipitation (dedolomitization), (2) sulfate reduction accompanying microbial degradation of organic carbon, (3) recrystallization of calcite (isotopic exchange), and (4) mixing of fresh water with as much as 7% saline water in some coastal areas. The calculated cumulative net mineral transfers are negligibly small in upgradient parts of the aquifer and increase significantly in downgradient parts of the aquifer, reflecting, at least in part, upward leakage from the Lower Floridan aquifer and circulation that contacted middle confining units in the Floridan aquifer system. The adjusted radiocarbon ages are independent of flow path and represent travel times of water from the recharge area to the sample point in the aquifer. Downgradient from Polk City (adjusted age 1.7 ka) and Keystone Heights (adjusted age 0.4 ka), 14 of the 22 waters have adjusted 14C ages of 20-30 ka, indicating that most of the fresh-water resource in the Upper Floridan aquifer today was recharged during the last glacial period. All of the paleowaters are enriched in 18O and 2H relative to modern infiltration, with maximum enrichment in δ18O of approximately 2.0‰. Résumé. Les modèles de réactions géochimiques ont été évalués afin de tester la datation par le radiocarbone du carbone minéral dissous (CMD) des eaux souterraines dans les parties captives de la nappe supérieure de Floride, en Floride centrale et nord-orientale (États-Unis). Les réactions géochimiques prédominantes affectant l'activité en 14C du CMD comprennent (1) la dissolution de la dolomite et de l'anhydrite accompagnée de la précipitation de la calcite (dédolomitisation), (2) la réduction des sulfates accompagnant une dégradation microbienne du carbone organique, (3) la recristallisation de la calcite (échange isotopique), et (4) le mélange d'eau douce avec de l'eau salée, jusqu'à 7%, dans certaines zones côtières. Les transferts minéraux nets calculés sont extrêmement faibles dans les parties situées dans l'amont de l'aquifère ils augmentent significativement dans les zones de l'aval, montrant en partie au moins l'existence d'une drainance ascendante depuis l'aquifère inférieur de Floride et une circulation qui met en relation les unités captives du système aquifère de Floride. Les âges radiocarbone corrigés sont indépendants des trajets d'écoulement et représentent des temps de transit de l'eau depuis la zone de recharge vers le point de prélèvement dans l'aquifère. En aval de Polk City (âge corrigé 1,7 ka) et de Keystone Heighats (âge corrigé 0,4 ka), 14 des 22 échantillons d'eau présentent des âges corrigés compris entre 20 et 30 ka, ce qui montre que la plus grande partie des ressources actuelles en eau douce de la nappe supérieure de Floride provient d'une recharge effectuée au cours de la dernière période glaciaire. Toutes ces eaux anciennes sont enrichies en 18O et en 2H par rapport à l'infiltration actuelle, avec un enrichissement maximal de δ18O d'environ 2.0‰. Resumen. Se han evaluado varios modelos geoquímicos con el fin de mejorar la datación del carbono inorgánico disuelto (CID) en las aguas subterráneas de las zonas confinadas del acuífero Superior de Florida, que ocupa el centro y nordeste de Florida (Estados Unidos). Las reacciones geoquímicas dominantes en cuanto a la actividad del 14C del CID incluyen: (1) disolución de dolomita y anhidrita, con precipitación de calcita (o de-dolomitización), (2) reducción de sulfato, acompañada por degradación microbiana de carbón orgánico, (3) recristalización de calcita (intercambio isotópico), y (4) mezcla de agua dulce con hasta un 7% de agua salina en algunas áreas costeras. Se ha calculado que las transferencias netas acumuladas de mineral son despreciables en las zonas situadas aguas arriba, y aumentan significativamente aguas abajo. Esto refleja, al menos en parte, el goteo desde el acuífero Inferior de Florida y la interconexión de las unidades confinantes en el sistema acuífero de Florida. Las edades de radiocarbono estimadas son independientes de las líneas de flujo y representan tiempos de tránsito de aguas desde el área de recarga hasta el punto de muestreo en el acuífero. Aguas debajo de la ciudad de Polk (edad de 1.700 años) y Keystone Heighats (edad de 400 años), 14 de las 22 muestras tienen edades estimadas de entre 20.000 y 30.000 años, hecho que indica que la mayor parte de los recursos actuales de agua dulce en el acuífero Superior de Florida fue recargada durante el último período glacial. Todas las paleoaguas están enriquecidas en 18O y 2H con respecto al agua actual de recarga, con un factor máximo de enriquecimiento en 18O de, aproximadamente, 2,0.

Language Assessment Scales, Level 2, LAS II, for Grades 6 and Up, English/Spanish. Examiner's Manual.

ERIC Educational Resources Information Center

Duncan, Sharon E.; De Avila, Edward A.

Language Assessment Scales, Level 2 (LAS II) are used to assess the linguistic proficiency of limited-English-speaking or non-English-speaking adolescents. LAS II, like its predecessor, LAS I, provides a picture of oral linguistic proficiency based on a student's performance across four linguistic subsystems: phonemic, lexical, syntactic and…

Pedagogia artistica: la conceptualizacion y la creatividad en estudiantes de ciencias de sexto grado

NASA Astrophysics Data System (ADS)

Ortiz Colon, Edwin A.

Se realizo un estudio fenomenologico sobre la conceptualizacion, la creatividad y el valor del dibujo en propiciar un contexto creativo para el aprendizaje de ciencias de sexto grado. La conceptualizacion se interpreto como un proceso que ocurre en las relaciones que los estudiantes establecen entre los temas de estudio y las ideas principales, las experiencias previas, las creencias personales, el tiempo y el valor de la conservacion ambiental. La esencia de la creatividad se definio en funcion de la imaginacion, las destrezas, la intencion, la libertad de pensamiento y expresion y el contexto. El dibujo propicio un ambiente creativo de aprendizaje en las ciencias al facilitar el uso del pensamiento cientifico profundo, el inquirir artistico y la expresion libre.

Phylogenetic and biogeographic relationships of the mouse opossum Thylamys (Didelphimorphia, Didelphidae) in southern South America.

PubMed

Eduardo Palma, R; Rivera-Milla, Eric; Yates, Terry L; Marquet, Pablo A; Meynard, Andrés P

2002-11-01

Nucleotide sequence data from the mitochondrial cytochrome b gene were used to evaluate the phylogenetic relationships among mouse opossum species of the genus Thylamys. Based on approximately 1000 bp in five of the six species of the genus and including different localities for some of the species, we concluded that T. macrura from the subtropical forests of eastern Paraguay is the most primitive taxon. Subsequent radiation of the genus is explained mainly via founder effect speciation. This evolutionary scenario would account for the speciation of T. pusilla, T. venusta, T. pallidior, and T. elegans in the Chaco, southern Bolivia and northern Argentina, the Andean Altiplano, the Coastal Desert of Chile, and coastal Perú, respectively. Calibration of a molecular clock set the Pleistocene as the period for the differentiation of Thylamys species. The molecular results confirm the strong genetic connection between populations that inhabit the "pre-cordillera" of northern Chile (T. pallidior) and the canyons that run through the Atacama Desert to the lowlands in northern Chile. Our results confirm the occurrence of two Thylamys species in Chile, T. pallidior and T. elegans, within and south to the Atacama Desert, respectively. Copyright 2002 Elsevier Science (USA)

Potential application of Northern Argentine propolis to control some phytopathogenic bacteria.

PubMed

Ordóñez, R M; Zampini, I C; Moreno, M I Nieva; Isla, M I

2011-10-20

The antimicrobial activity of samples of Northern Argentine propolis (Tucumán, Santiago del Estero and Chaco) against phytopathogenic bacteria was assessed and the most active samples were identified. Minimal inhibitory concentration (MIC) values were determined by agar macrodilution and broth microdilution assays. Strong antibacterial activity was detected against Erwinia carotovora spp carotovora CECT 225, Pseudomonas syringae pvar tomato CECT 126, Pseudomonas corrugata CECT 124 and Xanthomonas campestris pvar vesicatoria CECT 792. The most active propolis extract (Tucumán, T1) was selected to bioguide isolation and identified for antimicrobial compound (2',4'-dihydroxychalcone). The antibacterial chalcone was more active than the propolis ethanolic extract (MIC values of 0.5-1 μg ml(-1) and 9.5-15 μg ml(-1), respectively). Phytotoxicity assays were realized and the propolis extracts did not retard germination of lettuce seeds or the growth of onion roots. Propolis solutions applied as sprays on tomato fruits infected with P. syringae reduced the severity of disease. Application of the Argentine propolis extracts diluted with water may be promising for the management of post harvest diseases of fruits. Copyright © 2010 Elsevier GmbH. All rights reserved.

Revisiting the Diego Blood Group System in Amerindians: Evidence for Gene-Culture Comigration.

PubMed

Bégat, Christophe; Bailly, Pascal; Chiaroni, Jacques; Mazières, Stéphane

2015-01-01

Six decades ago the DI*A allele of the Diego blood group system was instrumental in proving Native American populations originated from Siberia. Since then, it has received scant attention. The present study was undertaken to reappraise distribution of the DI*A allele in 144 Native American populations based on current knowledge. Using analysis of variance tests, frequency distribution was studied according to geographical, environmental, and cultural parameters. Frequencies were highest in Amazonian populations. In contrast, DI*A was undetectable in subarctic, Fuegian, Panamanian, Chaco and Yanomama populations. Closer study revealed a correlation that this unequal distribution was correlated with language, suggesting that linguistic divergence was a driving force in the expansion of DI*A among Native Americans. The absence of DI*A in circumpolar Eskimo-Aleut and Na-Dene speakers was consistent with a late migratory event confined to North America. Distribution of DI*A in subtropical areas indicated that gene and culture exchanges were more intense within than between ecozones. Bolstering the utility of classical genetic markers in biological anthropology, the present study of the expansion of Diego blood group genetic polymorphism in Native Americans shows strong evidence of gene-culture comigration.

Astronomical Heritage and Aboriginal People: Conflicts and Possibilities

NASA Astrophysics Data System (ADS)

Martín López, Alejandro

2015-08-01

In this presentation we will address the issues relating to the astronomical heritage of contemporary aboriginal groups and othe minorities. We will deal specially with the intangible astronomical heritage and their particularities. We will study (from the ethnographic experience with Aboriginal groups, Creoles and Europeans in the Argentine Chaco) the conflicts referring to the different ways, in which the native's knowledge and practice are categorized by the natives themselves, by the scientists, the state politicians, the professional artists and NGOs. We will address several cases to illustrate this kind of conflicts. We will analyze the complexities of patrimonial policies when it are applied to practices and representations of contemporary communities involved in power relations with national states and the global system. The essentialization of identities, the folklorization of representations and practices, the fossilization of aboriginal peoples are some of the risks of give the label of "cultural heritage" without a careful consideration of each specific case.In particular we will suggest possible forms by which he international scientific community could collaborate to improve the agenda of national states instead of reproducing colonial prejudices. In this way we will contribute to promote the respect for ethnic and religious minorities.

Astronomical Heritage and Aboriginal People: Conflicts and Possibilities

NASA Astrophysics Data System (ADS)

López, Alejandro Martín

2016-10-01

In this presentation we address issues relating to the astronomical heritage of contemporary aboriginal groups and other minorities. We deal specially with intangible astronomical heritage and its particularities. Also, we study (from ethnographic experience with Aboriginal groups, Creoles and Europeans in the Argentine Chaco) the conflicts referring to the different ways in which the natives' knowledge and practice are categorized by the natives themselves, by scientists, state politicians, professional artists and NGOs. Furthermore, we address several cases that illustrate these kinds of conflicts. We aim to analyze the complexities of patrimonial policies when they are applied to practices and representations of contemporary communities involved in power relations with national states and the global system. The essentialization of identities, the folklorization of representations and practices, and the fossilization of aboriginal peoples are some of the risks of applying the label ``cultural heritage'' without a careful consideration of each specific case. In particular we suggest possible ways in which the international scientific community could collaborate to improve the agenda of national states instead of reproducing colonial prejudices. In this way, we aim to contribute to the promotion of respect for ethnic and religious minorities.

Responses and toxin bioaccumulation in duckweed (Lemna minor) under microcystin-LR, linear alkybenzene sulfonate and their joint stress.

PubMed

Wang, Zhi; Xiao, Bangding; Song, Lirong; Wang, Chunbo; Zhang, Junqian

2012-08-30

Microcystin-LR (MCLR) and linear alkylbenzene sulfonate (LAS) are commonly found in eutrophic lakes due to toxic cyanobacterial blooms and exogenous organic compounds pollution. However, the ecotoxicological risk of their combination in the aquatic environment is unknown. This study investigated the effects of MCLR, LAS and their mixture on duckweed (Lemna minor) growth and physiological responses. MCLR accumulation in duckweed, with or without LAS, was also examined. Growth of duckweed and chlorophyll-a contents were significantly reduced after 8d exposure to high concentrations of MCLR (≥ 3 μg/ml), LAS (≥ 20 μg/ml) and their mixture (≥ 3+10 μg/ml). After 2d of exposure, superoxide dismutase activity and glutathione content in duckweed increased with increasing concentrations of MCLR, LAS and their mixture, with a significant difference observable after 8d of exposure. When MCLR and LAS concentrations were lower (≤ 0.1+1 μg/ml), the interaction of them is synergistic, but when the concentrations were higher, the synergy was weak. MC accumulation was much higher at 2d than at 8d when duckweed was exposed to lower concentrations of MCLR (≤ 3 μg/ml) or MCLR-LAS (≤ 3+10 μg/ml). Furthermore, LAS significantly enhanced the accumulation of MCLR in duckweed, even with LAS concentrations as low as 0.3 μg/ml (environmental concentration), indicating that greater negative ecological risks and higher MCLR phytoremediation potentials of duckweed might occur in MCLR-LAS-concomitant water. Copyright © 2012 Elsevier B.V. All rights reserved.

Current Trends in the Management of Lateral Ankle Sprain in the United States.

PubMed

Feger, Mark A; Glaviano, Neal R; Donovan, Luke; Hart, Joseph M; Saliba, Susan A; Park, Joseph S; Hertel, Jay

2017-03-01

To characterize trends in the acute management (within 30 days) after lateral ankle sprain (LAS) in the United States. Descriptive epidemiology study. Of note, 825 718 ankle sprain patients were identified; 96.2% were patients with LAS. Seven percent had an associated fracture and were excluded from the remaining analysis. Primary and tertiary care settings. We queried a database of national health insurance records for 2007 to 2011 by ICD-9 codes for patients with LAS while excluding medial and syndesmotic sprains and any LAS with an associated foot or ankle fracture. The percentage of patients to receive specific diagnostic imaging, orthopedic devices, or physical therapy treatments within 30 days of the LAS diagnosis and the associated costs. Over two-thirds of patients with LAS without an associated fracture received radiographs, 9% received an ankle brace, 8.1% received a walking boot, 6.5% were splinted, and 4.8% were prescribed crutches. Only 6.8% received physical therapy within 30 days of their LAS diagnosis, 94.1% of which performed therapeutic exercise, 52.3% received manual therapy, and 50.2% received modalities. The annual cost associated with physician visits, diagnostic imaging, orthopedic devices, and physical therapy was 152 million USD, 81.5% was from physician evaluations, 7.9% from physical therapy, 7.2% from diagnostic imaging, and 3.4% from orthopedic devices. Most patients with LAS do not receive supervised rehabilitation. The small proportion of patients with LAS to receive physical therapy get rehabilitation prescribed in accordance with clinical practice guidelines. The majority (>80%) of the LAS financial burden is associated with physician evaluations.

Language Assessment Scales, LAS I, for Grades K-5, English/Spanish. Second Edition.

ERIC Educational Resources Information Center

De Avila, Edward A.; Duncan, Sharon E.

Language Assessment Scales, LAS I, are designed for children in grades K-5. LAS I accommodates ethnic and linguistic differences and provides direct language activities taken from the popular culture of both English- and Spanish-speaking peoples. LAS I consists of two independent tests, one in English and the other in Spanish, presented largely on…

Binarias en cúmulos abiertos: ?`Qué hay de nuevo?

NASA Astrophysics Data System (ADS)

Levato, H.

Las herramientas modernas para detectar duplicidad han jugado un papel fundamental en el resurgimiento del estudio de la binaridad en cúmulos abiertos. El fracaso de las teorías de bifurcación para explicar la formación de estrellas dobles ha puesto en consideración los encuentros de estrellas en cúmulos para formar binarias. Existen muchas pruebas empíricas que pueden realizarse para verificar las creencias actuales. En esta revisión del tema se hace un breve resumen de la historia del problema y se analiza el conocimiento actual. Se proponen las investigaciones y programas que darían lugar a la comprobación de las predicciones que surgen de considerar que las binarias en cúmulos se forman por encuentros.

Geophysical and petrological modelling of the structure and composition of the crust and upper mantle in complex geodynamic settings: The Tyrrhenian Sea and surroundings

NASA Astrophysics Data System (ADS)

Panza, G. F.; Peccerillo, A.; Aoudia, A.; Farina, B.

2007-01-01

Information on the physical and chemical properties of the lithosphere-asthenosphere system (LAS) can be obtained by geophysical investigation and by studies of petrology-geochemistry of magmatic rocks and entrained xenoliths. Integration of petrological and geophysical studies is particularly useful in geodynamically complex areas characterised by abundant and compositionally variable young magmatism, such as in the Tyrrhenian Sea and surroundings. A thin crust, less than 10 km, overlying a soft mantle (where partial melting can reach about 10%) is observed for Magnaghi, Vavilov and Marsili, which belong to the Central Tyrrhenian Sea backarc volcanism where subalkaline rocks dominate. Similar characteristics are seen for the uppermost crust of Ischia. A crust about 20 km thick is observed for the majority of the continental volcanoes, including Amiata-Vulsini, Roccamonfina, Phlegraean Fields-Vesuvius, Vulture, Stromboli, Vulcano-Lipari, Etna and Ustica. A thicker crust is present at Albani - about 25 km - and at Cimino-Vico-Sabatini — about 30 km. The structure of the upper mantle, in contrast, shows striking differences among various volcanic provinces. Volcanoes of the Roman region (Vulsini-Sabatini-Alban Hills) sit over an upper mantle characterised by Vs mostly ranging from about 4.2 to 4.4 km/s. At the Alban Hills, however, slightly lower Vs values of about 4.1 km/s are detected between 60 and 120 km of depth. This parallels the similar and rather homogeneous compositional features of the Roman volcanoes, whereas the lower Vs values detected at the Alban Hills may reflect the occurrence of small amounts of melts within the mantle, in agreement with the younger age of this volcano. The axial zone of the Apennines, where ultrapotassic kamafugitic volcanoes are present, has a mantle structure with high-velocity lid ( Vs ˜ 4.5 km/s) occurring at the base of a 40-km-thick crust. Beneath the Campanian volcanoes of Vesuvius and Phlegraean Fields, the mantle structure shows a rigid body dipping westward, a feature that continues southward, up to the eastern Aeolian arc. In contrast, at Ischia the upper mantle contains a shallow low-velocity layer ( Vs = 3.5-4.0 km/s) just beneath a thin but complex crust. The western Aeolian arc and Ustica sit over an upper mantle with Vs ˜ 4.2-4.4 km/s, although a rigid layer ( Vs = 4.55 km/s) from about 80 to 150 km occurs beneath the western Aeolian arc. In Sardinia, no significant differences in the LAS structure are detected from north to south. The petrological-geochemical signatures of Italian volcanoes show strong variations that allow us to distinguish several magmatic provinces. These often coincide with mantle sectors identified by Vs tomography. For instance, the Roman volcanoes show remarkable similar petrological and geochemical characteristics, mirroring similar structure of the LAS. The structure and geochemical-isotopic composition of the upper mantle change significantly when we move to the Stromboli-Campanian volcanoes. The geochemical signatures of Ischia and Procida volcanoes are similar to other Campanian centres, but Sr-Pb isotopic ratios are lower marking a transition to the backarc mantle of the Central Tyrrhenian Sea. The structural variations from Stromboli to the central (Vulcano and Lipari) and western Aeolian arc are accompanied by strong variations of geochemical signatures, such as a decrease of Sr-isotope ratios and an increase of Nd-, Pb-isotope and LILE/HFSE ratios. The dominance of mafic subalkaline magmatism in the Tyrrhenian Sea basin denotes large degrees of partial melting, well in agreement with the soft characteristics of the uppermost mantle in this area. In contrast, striking isotopic differences of Plio-Quaternary volcanic rocks from southern to northern Sardinia does not find a match in the LAS geophysical characteristics. The combination of petrological and geophysical constraints allows us to propose a 3D schematic geodynamic model of the Tyrrhenian basin and bordering volcanic areas, including the subduction of the Ionian-Adria lithosphere in the southern Tyrrhenian Sea, and to place constraints on the geodynamic evolution of the whole region.

Field Test of Slow Moving Traffic Alerting System on Freeways in Las Vegas, Nevada : Assessment of the Effectiveness of the Dynamic Message Signs on the Freeways in Las Vegas, Nevada.

DOT National Transportation Integrated Search

2015-10-17

It has been perceived that the travelers do not respond to the incident messages on the dynamic message signs in the Las Vegas area in Nevada. The objective of the study is to evaluate whether dynamic message signs (DMS) in the Las Vegas freeway syst...

40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

Code of Federal Regulations, 2014 CFR

2014-07-01

... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September 17...

40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

Code of Federal Regulations, 2010 CFR

2010-07-01

... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September 17...

40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

Code of Federal Regulations, 2013 CFR

2013-07-01

... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September 17...

40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

Code of Federal Regulations, 2011 CFR

2011-07-01

... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September 17...

40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

Code of Federal Regulations, 2012 CFR

2012-07-01

... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September 17...

Biodegradation of the surfactant linear alkylbenzenesulfonate in sewage- contaminated groundwater: A comparison of column experiments and field tracer tests

USGS Publications Warehouse

Krueger, C.J.; Radakovich, K.M.; Sawyer, T.E.; Barber, L.B.; Smith, R.L.; Field, J.A.

1998-01-01

Transport and biodegradation of linear alkylbenzenesulfonate (LAS) in sewage-contaminated groundwater were investigated for a range of dissolved oxygen concentrations. Both laboratory column and an 80-day continuous injection tracer test field experiments were conducted. The rates of LAS biodegradation increased with increasing dissolved oxygen concentrations and indicated the preferential biodegradation of the longer alkyl chain LAS homologues (i.e., C12 and C13) and external isomers (i.e., 2-and 3- phenyl). However, for similar dissolved oxygen concentrations, mass removal rates for LAS generally were 2-3 times greater in laboratory column experiments than in the field tracer test. Under low oxygen conditions (<1 mg/L) only a fraction of the LAS mixture biodegraded in both laboratory and field experiments. Biodegradation rate constants for the continuous injection field test (0.002-0.08 day-1) were comparable to those estimated for a 3-h injection (pulsed) tracer test conducted under similar biogeochemical conditions, indicating that increasing the exposure time of aquifer sediments to LAS did not increase biodegradation rates.Transport and biodegradation of linear alkylbenzenesulfonate (LAS) in sewage-contaminated groundwater were investigated for a range of dissolved oxygen concentrations. Both laboratory column and an 80-day continuous injection tracer test field experiments were conducted. The rates of LAS biodegradation increased with increasing dissolved oxygen concentrations and indicated the preferential biodegradation of the longer alkyl chain LAS homologues (i.e., C12 and C13) and external isomers (i.e., 2- and 3-phenyl). However, for similar dissolved oxygen concentrations, mass removal rates for LAS generally were 2-3 times greater in laboratory column experiments than in the field tracer test. Under low oxygen conditions (<1 mg/L) only a fraction of the LAS mixture biodegraded in both laboratory and field experiments. Biodegradation rate constants for the continuous injection field test (0.002-0.08 day-1) were comparable to those estimated for a 3-h injection (pulsed) tracer test conducted under similar biogeochemical conditions, indicating that increasing the exposure time of aquifer sediments to LAS did not increase biodegradation rates.

Dispersal and longevity of wild and mass-reared Anastrepha Ludens and Anastrepha Obliqua (Diptera: Tephritidae)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hernandez, E.; Orozco, D.; Flores Breceda, S.

The rates of dispersal and survival of sterile mass-reared laboratory flies and sterile wild flies of Anastrepha ludens (Loew) and Anastrepha obliqua (Macquart) were estimated and compared with a regular rectangular array of 64 food-baited traps spaced 60 m between traps around the release point in Tapachula Chiapas, Mexico. The traps were scored every day during the first week, and then every 3 d over a 30-d period. For A. obliqua, the number of males recaptured was higher than that of females, while for A. ludens, females were recaptured more frequently than males. The recapture rate for the wild strainsmore » ranged from 0.6-24.8% for A. ludens and 1.3-16.2% for A. obliqua and the corresponding ranges for the mass-reared strains were 0.5-7.1% and 0.5-3.0% respectively. The life expectancy was 4.7 d for wild and 4.3 d for mass-reared A. obliqua males but 3 and 2 d, respectively, for wild and mass-reared A. ludens males. The net displacement of A. ludens and A. obliqua ranged approximately from 100-250 m and took place mostly on the first day. Wild A. ludens moved to the northwest from the release point while the mass-reared strain moved to the west. The A. obliqua wild flies moved to the west, while the mass-reared strain shifted to the southwest. We discuss the implications of our findings as to the spacing and frequency of sterile fly releases for the suppression of wild populations. (author) [Spanish] La dispersion y longevidad de las moscas esteriles silvestres y de cria masiva de Anastrepha ludens (Loew) y A. obliqua (Macquart) fueron determinadas y comparadas utilizando un arreglo rectangular de 64 trampas espaciadas a 60 metros entre trampas alrededor del punto de liberacion en Tapachula Chiapas, Mexico. Las trampas fueron revisadas y evaluadas diariamente durante la primera semana y despues cada tres dias hasta completar 30 dias. Para A. obliqua la cantidad de machos capturados fue mayor que la cantidad de hembras; mientras que para A. ludens las hembras fueron capturadas con mayor frecuencia que los machos. La recaptura de moscas silvestres de A. ludens fue de 0.6 a 24.8%, para A. obliqua fue del 1.3 al 16.2%, para moscas de laboratorio fue de 0.5 a 7.1 y 0.5 a 3%, respectivamente. La esperanza de vida correspondio a 4.7 y 4.3 dias para machos silvestres y de laboratorio de A. obliqua respectivamente; mientras que 3 y 2 dias fueron para los machos silvestres y de laboratorio de A. ludens . La dispersion para A. ludens y A. obliqua fue de 100 a 250 m tanto para individuos silvestres como de laboratorio. Los adultos de A. ludens silvestre se desplazaron del punto central de liberacion al noroeste, los individuos de laboratorio se movieron hacia el oeste del plano Cartesiano. A su vez los adultos de A. obliqua silvestre se movieron hacia el oeste y las de laboratorio hacia el suroeste. Discutimos las implicaciones de nuestros resultados con relacion al espaciamiento y frecuencia de las liberaciones de moscas esteriles para la supresion de poblaciones silvestres. (author)« less

Teaching and learning the geological knowledge as a part of the science education general field

NASA Astrophysics Data System (ADS)

Aguirre-Pérez, Constancio

2010-05-01

Since the early 50s of last century the Teaching of Science has undergone a process of continuous development, (Gutiérrez, 1987; Aliberas, Gutierrez and Izquierdo, 1989) to become a scientific discipline largely accepted as such by many different universities worldwide. Besides, the proliferation of publications, magazines, conferences, symposia, meetings, and so on, proves this assertion. In these publications and meetings the Teaching of Science (or Science Education in more general terms) is addressed as a new field of research, teaching and educational innovation focused on the processes of teaching and learning of the experimental sciences (all of them: Physics, Chemistry, Biology and Geology). The study of this discipline is undertaken from different pedagogical, epistemological, psychological and sociological approaches. From this general perspective we can say that over the last two decades each of the sciences has developed specific characteristics so that, today, we could speak about specific didactics for each one of them. In the case of Geology (or Geoscience) Teaching there have been significant contributions from the following fields of research: the students' prior ideas (constructivist approach), the history of geology (as a subject-specific field) and from epistemology (Pedrinaci, E. 2000). The body of geoscience knowledge has an internal logic (as happens with the other science subjects) that allows us to organize the contents to teach, selecting, arranging and establishing proper relations between them. Still geology has a central, transverse, inter-and transdisciplinary character for its relationship with the other sciences. This character makes it appear as one of the disciplines with a huge potential to combine different methodologies of teaching and learning and different learning models already tested in the research field of Physics, Chemistry or Biology Education. Moreover, the most recent term coined for it "geosciences or earth and space sciences" emphasizes still further such character receiving the contributions of physics, chemistry, biology and environmental science in a kind of scientific-technical mixture which enriches the discipline itself and constitutes a fundamental basis for the evolution of knowledge in its broadest sense (Martinez Frias et al. 2008). In this paper we propose to show some of the experiences and didactic innovations in the teaching of geology found in the scientific literature in recent years and likewise part of an author's own work on the establishment of analogies on the time variable based on Carl Sagan's cosmic calendar. With these analogies we try to approximate geologic times to the understanding of high school and first university courses students (Aguirre-Perez, C. 2008) REFERENCES ALIBERAS, J. GUTIÉRREZ, R. and IZQUIERDO, M. (1989). La Didáctica de las Ciencias: Una empresa racional. Enseñanza de las Ciencias, 7 (3), pp. 227-284. GUTIÉRREZ, R. (1987). Psicología y aprendizaje de las Ciencias. El modelo de Ausubel. Enseñanza de las Ciencias, 5 (2), pp. 118-128. MARTÍNEZ FRÍAS, J. LUNAR, R. RODRÍGUEZ-LOSADA, J.A. EFF-DARWICH, A. and MADERO JARABO, J. (2008)"La Geología en la exploración planetaria (Geology inplanetary exploration). Geo-temas 10, pp. 1621-1624. PEDRINACI, E. (2000): La Enseñanza y el aprendizaje del conocimiento geológico. Didáctica de las Ciencias Experimentales. Teoría y Práctica de la Enseñanza de las ciencias, pp. 479-503. Ed. Marfil.

Prophage-Mediated Dynamics of ‘Candidatus Liberibacter asiaticus’ Populations, the Destructive Bacterial Pathogens of Citrus Huanglongbing

PubMed Central

Zhou, Lijuan; Powell, Charles A.; Li, Wenbin; Irey, Mike; Duan, Yongping

2013-01-01

Prophages are highly dynamic components in the bacterial genome and play an important role in intraspecies variations. There are at least two prophages in the chromosomes of Candidatus Liberibacter asiaticus’ (Las) Floridian isolates. Las is both unculturable and the most prevalent species of Liberibacter pathogens that cause huanglongbing (HLB), a worldwide destructive disease of citrus. In this study, seven new prophage variants resulting from two hyper-variable regions were identified by screening clone libraries of infected citrus, periwinkle and psyllids. Among them, Types A and B share highly conserved sequences and localize within the two prophages, FP1 and FP2, respectively. Although Types B and C were abundant in all three libraries, Type A was much more abundant in the libraries from the Las-infected psyllids than from the Las-infected plants, and Type D was only identified in libraries from the infected host plants but not from the infected psyllids. Sequence analysis of these variants revealed that the variations may result from recombination and rearrangement events. Conventional PCR results using type-specific molecular markers indicated that A, B, C and D are the four most abundant types in Las-infected citrus and periwinkle. However, only three types, A, B and C are abundant in Las-infected psyllids. Typing results for Las-infected citrus field samples indicated that mixed populations of Las bacteria present in Floridian isolates, but only the Type D population was correlated with the blotchy mottle symptom. Extended cloning and sequencing of the Type D region revealed a third prophage/phage in the Las genome, which may derive from the recombination of FP1 and FP2. Dramatic variations in these prophage regions were also found among the global Las isolates. These results are the first to demonstrate the prophage/phage-mediated dynamics of Las populations in plant and insect hosts, and their correlation with insect transmission and disease development. PMID:24349235

Prophage-mediated dynamics of 'Candidatus Liberibacter asiaticus' populations, the destructive bacterial pathogens of citrus huanglongbing.

PubMed

Zhou, Lijuan; Powell, Charles A; Li, Wenbin; Irey, Mike; Duan, Yongping

2013-01-01

Prophages are highly dynamic components in the bacterial genome and play an important role in intraspecies variations. There are at least two prophages in the chromosomes of Candidatus Liberibacter asiaticus' (Las) Floridian isolates. Las is both unculturable and the most prevalent species of Liberibacter pathogens that cause huanglongbing (HLB), a worldwide destructive disease of citrus. In this study, seven new prophage variants resulting from two hyper-variable regions were identified by screening clone libraries of infected citrus, periwinkle and psyllids. Among them, Types A and B share highly conserved sequences and localize within the two prophages, FP1 and FP2, respectively. Although Types B and C were abundant in all three libraries, Type A was much more abundant in the libraries from the Las-infected psyllids than from the Las-infected plants, and Type D was only identified in libraries from the infected host plants but not from the infected psyllids. Sequence analysis of these variants revealed that the variations may result from recombination and rearrangement events. Conventional PCR results using type-specific molecular markers indicated that A, B, C and D are the four most abundant types in Las-infected citrus and periwinkle. However, only three types, A, B and C are abundant in Las-infected psyllids. Typing results for Las-infected citrus field samples indicated that mixed populations of Las bacteria present in Floridian isolates, but only the Type D population was correlated with the blotchy mottle symptom. Extended cloning and sequencing of the Type D region revealed a third prophage/phage in the Las genome, which may derive from the recombination of FP1 and FP2. Dramatic variations in these prophage regions were also found among the global Las isolates. These results are the first to demonstrate the prophage/phage-mediated dynamics of Las populations in plant and insect hosts, and their correlation with insect transmission and disease development.

Conceptuaciones de los estudiantes de las facultades de educacion y ciencias naturales de la Universidad de Puerto Rico, recinto de Rio Piedras, acerca de la ciencia y la pseudociencia

NASA Astrophysics Data System (ADS)

Reyes Medina, Hector A.

Esta investigacion describe las conceptuaciones de los estudiantes de tercer ano o mas a nivel de bachillerato de los programas de Educacion en Ciencia y Ciencias Naturales de la Universidad de Puerto Rico, Recinto de Rio Piedras, acerca de lo establecido en la literatura para distinguir el conocimiento cientifico de las creencias pseudocientificas. Este estudio se guio por un diseno tipo encuesta transversal que permitio conocer de manera consistente las conceptuaciones de los estudiantes encuestados acerca de la Ciencia y la Pseudociencia. Ademas, permitio desarrollar inferencias estadisticas relacionadas a la poblacion de estudio, sus conceptuaciones y su inclinacion teorica en torno al Realismo y al Racionalismo cientifico moderados. El instrumento utilizado fue el Cuestionario acerca de las concepciones de la ciencia y la pseudocienca en estudiantes universitarios, Reyes (2015). Este cuestionario fue validado mediante la recopilacion de diversas fuentes de evidencias, entre estas se encuentran las evidencias basadas en el contenido, el proceso de respuesta, la estructura interna y de constructo. Tambien, se calculo el Alfa de Crombach para la escala total y para cada componente y se realizo un analisis de factores que demostro la presencia de seis componentes claramente definidos de acuerdo a lo esperado sobre las caracteristicas originales del instrumento. Las estadisticas utilizadas fueron descriptivas. Participaron 302 alumnos, de las facultades de educacion y ciencias naturales. Se encontro que las conceptuaciones de los estudiantes de ambas facultades se inclinan en un 66.2% a favor con lo establecido en el modelo teorico en torno al Realismo y al Racionalismo cientifico moderados. Sin embargo, aun hay un 33.8% de los estudiantes de ambas facultades que poseen conceptuaciones distintas al modelo teorico propuesto.

Reverse shoulder prosthesis in the treatment of locked anterior shoulders: a comparison with classic reverse shoulder indications.

PubMed

Kurowicki, Jennifer; Triplet, Jacob J; Momoh, Enesi; Moor, Molly A; Levy, Jonathan C

2016-12-01

Locked anterior shoulder (LAS) with static instability and anterior glenoid bone loss is challenging in the elderly population. Reverse shoulder arthroplasty (RSA) has been employed in treating these patients. No study has compared RSA for LAS with classically indicated RSA. A retrospective case-control study of patients treated with RSA for LAS with glenoid bone loss and static instability was performed using matched controls treated with primary RSA for classic indications. Twenty-four cases and 48 controls were evaluated. Average follow-up was 25.5 months, and median age was 76 years. Motion, outcome assessments, and postoperative radiographs were compared. Preoperatively, LAS had significantly less rotation and lower baseline outcome scores. Glenoid bone grafting was more common (P = .05) in the control group (26%) than in the LAS group (6.3%). Larger glenospheres were used more often (P = .001) in the LAS group (75%) than in the control group (29%). Both groups demonstrated significant improvements in pain, function, and outcome scores. Postoperatively, the control group had significantly better elevation and functional outcome scores. With the exception of flexion and Simple Shoulder Test score, effectiveness of treatment was similar between groups. Postoperative acromion stress fractures were seen in 21% of LAS patients and 9% of controls (P = .023) with a predominance of type 3 fractures in LAS. Two LAS patients remained dislocated. Patients with LAS treated with RSA can anticipate improvements in pain and function by use of larger glenospheres, often without the need for glenoid bone grafting. Worse postoperative motion and function and a higher incidence of acromion stress fracture may be expected. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Intrinsic Predictive Factors of Noncontact Lateral Ankle Sprain in Collegiate Athletes

PubMed Central

Kobayashi, Takumi; Yoshida, Masahiro; Yoshida, Makoto; Gamada, Kazuyoshi

2013-01-01

Background: Lateral ankle sprain (LAS) is one of the most common injuries in sports. Despite extensive research, intrinsic factors that predict initial and recurrent noncontact LAS remain undefined. Purpose: To identify the predictive factors of initial and recurrent noncontact LAS, focusing on ankle flexibility and/or alignment in collegiate athletes. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 191 athletes were assessed during the preseason for factors predictive of noncontact LAS. The baseline measurements included weightbearing dorsiflexion range of motion (ROM), leg-heel angle, foot internal rotation angle in plantar flexion, classification according to the mortise test, and navicular–medial malleolus (NMM) distance. Occurrence of noncontact LAS and participation in practice and games were prospectively recorded for 11 months. Results: Of the 191 athletes assessed, 169 (145 males, 24 females) completed the study; 125 athletes had a history of ankle sprain. During the observational period, 16 athletes suffered noncontact LAS (0.58 per 1000 athlete-exposures) consisting of 4 initial sprains and 12 recurrences. The hazard ratio estimated by a Cox regression analysis showed that athletes with an NMM distance ≥4.65 cm were 4.14 times more likely to suffer an initial noncontact LAS than were athletes with a shorter NMM distance (95% confidence interval, 1.12-14.30) and that athletes with a weightbearing dorsiflexion ROM >49.5° were 1.12 times as likely to suffer a recurrent noncontact LAS compared with athletes with a lower ROM (95% confidence interval, 1.05-1.20). Conclusion: NMM distance predicts initial noncontact LAS, and weightbearing dorsiflexion ROM predicts recurrent noncontact LAS. PMID:26535263

[Not Available].

PubMed

Cruz-Sáez, María Soledad; Pascual Jimeno, Aitziber; Wlodarczyk, Anna; Polo-López, Rocío; Echeburúa Odriozola, Enrique

2016-07-19

Introducción: los problemas relacionados con el peso constituyen un problema importante de salud pública debido a su alta prevalencia y a las adversas consecuencias que tienen para la salud.Objetivo: el objetivo principal de este estudio fue analizar si la depresión y la ansiedad tienen un papel mediador en la relación entre la insatisfacción corporal y las conductas de control del peso en chicas adolescentes con sobrepeso.Material y métodos: en el estudio participaron 140 mujeres de 16 a 20 años con sobrepeso. Las participantes tuvieron que cumplimentar la escala de insatisfacción corporal del EDI-2, las escalas de ansiedad y depresión del GHQ-28 y una adaptación de las escalas del EAT survey para evaluar las conductas de control del peso. Para los análisis estadísticos se utilizaron métodos de diferencias de medias, correlaciones y de mediación secuencial.Resultados: las adolescentes con sobrepeso y alta insatisfacción corporal presentaban más sintomatología ansiosa y depresiva, así como mayor cantidad de conductas de control del peso. Los resultados del análisis de mediación secuencial evidencian que el efecto de la insatisfacción corporal en las conductas de control del peso está parcialmente mediado por las variables depresión y ansiedad. Mientras que la sintomatología ansiosa presenta efectos directos e indirectos sobre las conductas de control de peso, la sintomatología depresiva solamente presenta un efecto indirecto.Conclusiones:los resultados del estudio destacan el rol mediador de la sintomatología depresiva y, especialmente, de la ansiedad en el desarrollo de conductas no saludables de control del peso.

Degradation of linear alkylabenzene sulfonate (LAS) and its compounds in Donghu Lake (Hubei, P.R.C.) determined by high performance liquid chromatography (HPLC)

NASA Astrophysics Data System (ADS)

Ayfer, Yediler; Xu, Ying; Zhang, Yongyuan; Chen, Junjian

1990-06-01

Commercial linear alkylbenzene sulfonate (LAS), mixture of alkylchain lengths and phenyl position isomers (C10-C13), is widely used as a major constituent of household and industrial detergents in the People's Republic of China. Degradation process and behaviour of LAS compounds during an 82-hour lake water die-away study, with an added LAS concentration of 1.5mg·L-1, was quantified and accomplished by HPLO-UV after extractionon the SepPek C18 reversed-phase cartridges. The degradation rate became progressively faster with increasing chain length. The technique described in this study is fast, sensitive and specific, and can be used to determine low levels of LAS and for establishing water quality criteria and standards relating to LAS and its compounds.

Estudio espectroscópico de la simbiótica CD-43o14304

NASA Astrophysics Data System (ADS)

García, L. G.; Brandi, E.; Ferrer, O. E.; Barbá, R.

En base a un monitoreo espectroscópico de estrellas simbióticas del hemisferio sur, realizado entre 1990 y 1997, se han reunido espectros en intermedia y alta resolución de la simbiótica CD-43o14304. Se trata de un sistema binario compuesto por una enana blanca y una gigante tipo K5 con un período orbital recientemente determinado, de 1448 días. Por primera vez se analiza el comportamiento espectral del objeto en un amplio rango espectral (3700-10000 Å) y en función de las fases orbitales observadas. Se interpretan las velocidades radiales de las emisiones y absorciones presentes y las variaciones en los perfiles estructurados de las líneas de Balmer y en el resto de las emisiones.

Las dificultades de sentir: el rol de las emociones en la estigmatización del VIH/SIDA

PubMed Central

MARZÁN-RODRÍGUEZ, Melissa; VARAS-DÍAZ, Nelson

2009-01-01

Resumen El Virus de Inmunodeficiencia Humana (VIH) y el Síndrome de Inmunodeficiencia Adquirida (SIDA) han sido motivo de estigmatización para las personas que viven con ellos. Esta estigmatización se ha estudiado consecuentemente desde la perspectiva de opiniones de agentes estigmatizantes. Estas opiniones han obviado sistemáticamente el rol de las emociones en el proceso de estigmatización. Llevamos a cabo este estudio con el propósito de identificar el rol de las emociones en el proceso de estigmatización de las personas que viven con el virus (PVVS) por parte de profesionales de la salud. Para lograr este objetivo utilizamos un diseño exploratorio y cualitativo en el cual utilizamos la técnica de entrevistas semiestructuradas a profundidad. La muestra estuvo compuesta por 80 profesionales de la salud y estudiantes de las siguientes especialidades: psicología, trabajo social, medicina y enfermería. Los resultados reflejaron la existencia de emociones asociadas al VIH/SIDA tales como pena, lástima, compasión, asco, fobia y miedo entre los/as profesionales y estudiantes que participaron. Las personas participantes evidenciaron la necesidad de controlar sus emociones al interactuar con PVVS. Los resultados apuntan a la necesidad de explorar aquellos factores que mediatizan las emociones, tales como el contexto social en que se manifiestan y ante quiénes se revelan, para lograr entender a cabalidad el estigma que rodea al VIH/SIDA. PMID:20212916

Holocene multidecadal and multicentennial droughts affecting Northern California and Nevada

USGS Publications Warehouse

Benson, L.; Kashgarian, Michaele; Rye, R.; Lund, S.; Paillet, F.; Smoot, J.; Kester, C.; Mensing, S.; Meko, D.; Lindstrom, S.

2002-01-01

Continuous, high-resolution ??18O records from cored sediments of Pyramid Lake, Nevada, indicate that oscillations in the hydrologic balance occurred, on average, about every 150 years (yr) during the past 7630 calendar years (cal yr). The records are not stationary; during the past 2740 yr, drought durations ranged from 20 to 100 yr and intervals between droughts ranged from 80 to 230 yr. Comparison of tree-ring-based reconstructions of climate change for the past 1200 yr from the Sierra Nevada and the El alpais region of northwest New Mexico indicates that severe droughts associated with Anasazi withdrawal from Chaco Canyon at 820 cal yr BP (calendar years before present) and final abandonment of Chaco Canyon, Mesa Verde, and the Kayenta area at 650 cal yr BP may have impacted much of the western United States.During the middle Holocene (informally defined in this paper as extending from 8000 to 3000 cal yr BP), magnetic susceptibility values of sediments deposited in Pyramid Lake's deep basin were much larger than late-Holocene (3000-0 cal yr BP) values, indicating the presence of a shallow lake. In addition, the mean ?? 18O value of CaCO3 precipitated between 6500 and 3430 cal yr BP was 1.6??? less than the mean value of CaCO3 precipitated after 2740 cal yr BP. Numerical calculations indicate that the shift in the ??18O baseline probably resulted from a transition to a wetter (> 30%) and cooler (3-5??C) climate. The existence of a relatively dry and warm middle-Holocene climate in the Truckee River - Pyramid Lake system is generally consistent with archeological, sedimentological, chemical, physical, and biological records from various sites within the Great Basin of the western United States. Two high-resolution Holocene-climate records are now available from the Pyramid and Owens lake basins which suggest that the Holocene was characterized by five climatic intervals. TIC and ??18O records from Owens Lake indicate that the first interval in the early Holocene (11,600-10,000 cal yr BP) was characterized by a drying trend that was interrupted by a brief (200 yr) wet oscillation centered at 10,300 cal yr BP. This was followed by a second early-Holocene interval (10,000-8000 cal yr BP) during which relatively wet conditions prevailed. During the early part of the middle Holocene (8000-6500 cal yr BP), high-amplitude oscillations in TIC in Owens Lake and ??18O in Pyramid Lake indicate the presence of shallow lakes in both basins. During the latter part of the middle Holocene (6500-3800 cal yr BP), drought conditions dominated, Owens Lake desiccated, and Lake Tahoe ceased spilling to the Truckee River, causing Pyramid Lake to decline. At the beginning of the late Holocene (???3000 cal yr BP), Lake Tahoe rose to its sill level and Pyramid Lake increased in volume. ?? 2002 Elsevier Science Ltd. All rights reserved.

Some climatic indicators in the period A.D. 1200-1400 in New Mexico

USGS Publications Warehouse

Leopold, Luna Bergere; Leopold, Estella B.; Wendorf, F.

1963-01-01

Three centuries before Columbus landed in America, the alluvial valleys of the south-western United States teemed with activity. The indigenous peoples had been building for 300 years a culture centred around community life based on flood-water farming and on hunting. A large number of pueblos had developed on sites earlier occupied by pit-house people. Community organization had brought advances in the ceramic and decorative arts, and changes in these artistic activities were sufficiently rapid that accurate chronologies have become available through the work of archaeologists during the twentieth century. These chronologies were at first unrelated to absolute dates, but the excavations of the 1920s at Chaco Canyon (New Mexico) provided the materials through which absolute dates could be established. This was accomplished by matching the changes in tree-ring width backward in time from living trees through successively older samples. Trees overlapping in age provided, by unique successions of distinctive tree-ring widths, a calendar by which individual logs could be dated. Beams found in the excavations at Chaco Canyon gave the first material by which the cultural developments culminating about A.D. 1300 could be dated.As a result of the time sequence provided by the tree-ring calendar, the dates within which different pottery types were developed could be accurately established. The dates of pottery types have been checked at a sufficiently large number of sites throughout the south-western United States that absolute dating of a large number of distinctive patterns can be considered unassailable. The sequence of tree-ring widths gives some climatic indications of great interest both to archaeologists and to climatologists. A relatively large number of logs spanning the period from A.D. 1200 to 1300 and, in particular, the years between 1276 and 1299, indicate that this period was generally characterized by smaller tree-ring widths than in the centuries immediately before and after. As a first approximation, the hundred years of narrow tree-ring widths were interpreted as a time of relative aridity, and have been referred to as the “Pueblo Drought”. More recent studies of tree-ring widths using sophisticated statistical techniques have thrown some doubts on any direct correlation of tree-ring widths with rainfall. Such doubts have been put forward before by Glock (1955) whose studies have been aimed at separating the various effects of seasonal occurrence of precipitation, the amount falling in various seasons, and other climatic factors in their relative influence on tree-ring widths. At present, then, tree-ring widths may be considered more satisfactory for reading chronology than for reading climate. It is this concern about direct correlation of tree-ring width with climate that led to initiation of the present study. This work is a preliminary attempt to obtain independent evidence from pollen concerning the probable nature of the vegetation and thus the climate in a period known to be characterized by narrow tree rings.

Holocene multidecadal and multicentennial droughts affecting Northern California and Nevada

NASA Astrophysics Data System (ADS)

Benson, Larry; Kashgarian, Michaele; Rye, Robert; Lund, Steve; Paillet, Fred; Smoot, Joseph; Kester, Cynthia; Mensing, Scott; Meko, Dave; Lindström, Susan

2002-02-01

Continuous, high-resolution δ18O records from cored sediments of Pyramid Lake, Nevada, indicate that oscillations in the hydrologic balance occurred, on average, about every 150 years (yr) during the past 7630 calendar years (cal yr). The records are not stationary; during the past 2740 yr, drought durations ranged from 20 to 100 yr and intervals between droughts ranged from 80 to 230 yr. Comparison of tree-ring-based reconstructions of climate change for the past 1200 yr from the Sierra Nevada and the El Malpais region of northwest New Mexico indicates that severe droughts associated with Anasazi withdrawal from Chaco Canyon at 820 cal yr BP (calendar years before present) and final abandonment of Chaco Canyon, Mesa Verde, and the Kayenta area at 650 cal yr BP may have impacted much of the western United States.During the middle Holocene (informally defined in this paper as extending from 8000 to 3000 cal yr BP), magnetic susceptibility values of sediments deposited in Pyramid Lake's deep basin were much larger than late-Holocene (3000-0 cal yr BP) values, indicating the presence of a shallow lake. In addition, the mean δ18O value of CaCO 3 precipitated between 6500 and 3430 cal yr BP was 1.6‰ less than the mean value of CaCO 3 precipitated after 2740 cal yr BP. Numerical calculations indicate that the shift in the δ18O baseline probably resulted from a transition to a wetter (>30%) and cooler (3-5°C) climate. The existence of a relatively dry and warm middle-Holocene climate in the Truckee River-Pyramid Lake system is generally consistent with archeological, sedimentological, chemical, physical, and biological records from various sites within the Great Basin of the western United States. Two high-resolution Holocene-climate records are now available from the Pyramid and Owens lake basins which suggest that the Holocene was characterized by five climatic intervals. TIC and δ18O records from Owens Lake indicate that the first interval in the early Holocene (11,600-10,000 cal yr BP) was characterized by a drying trend that was interrupted by a brief (200 yr) wet oscillation centered at 10,300 cal yr BP. This was followed by a second early-Holocene interval (10,000-8000 cal yr BP) during which relatively wet conditions prevailed. During the early part of the middle Holocene (8000-6500 cal yr BP), high-amplitude oscillations in TIC in Owens Lake and δ18O in Pyramid Lake indicate the presence of shallow lakes in both basins. During the latter part of the middle Holocene (6500-3800 cal yr BP), drought conditions dominated, Owens Lake desiccated, and Lake Tahoe ceased spilling to the Truckee River, causing Pyramid Lake to decline. At the beginning of the late Holocene (˜3000 cal yr BP), Lake Tahoe rose to its sill level and Pyramid Lake increased in volume.

Paleogeography of the upper Paleozoic basins of southern South America: An overview

NASA Astrophysics Data System (ADS)

Limarino, Carlos O.; Spalletti, Luis A.

2006-12-01

The paleogeographic evolution of Late Paleozoic basins located in southern South America is addressed. Three major types of basins are recognized: infracratonic or intraplate, arc-related, and retroarc. Intraplate basins (i.e., Paraná, Chaco-Paraná, Sauce Grande-Colorado, and La Golondrina) are floored by continental or quasi-continental crust, with low or moderate subsidence rates and limited magmatic and tectonic activity. Arc-related basins (northern and central Chile, Navidad-Arizaro, Río Blanco, and Calingasta-Uspallata basins and depocenters along Chilean Patagonia) show a very complex tectonic history, widespread magmatic activity, high subsidence rates, and in some cases metamorphism of Late Paleozoic sediments. An intermediate situation corresponds to the retroarc basins (eastern Madre de Dios, Tarija, Paganzo, and Tepuel-Genoa), which lack extensive magmatism and metamorphism but in which coeval tectonism and sedimentation rates were likely more important than those in the intraplate region. According to the stratigraphic distribution of Late Paleozoic sediments, regional-scale discontinuities, and sedimentation pattern changes, five major paleogeographic stages are proposed. The lowermost is restricted to the proto-Pacific and retroarc basins, corresponds to the Mississippian (stage 1), and is characterized by shallow marine and transitional siliciclastic sediments. During stage 2 (Early Pennsylvanian), glacial-postglacial sequences dominated the infracratonic (or intraplate) and retroarc basins, and terrigenous shallow marine sediments prevailed in arc-related basins. Stage 3 (Late Pennsylvanian-Early Cisuralian) shows the maximum extension of glacial-postglacial sediments in the Paraná and Sauce Grande-Colorado basins (intraplate region), whereas fluvial deposits interfingering with thin intervals of shallow marine sediments prevailed in the retroarc basins. To the west, arc-related basins were dominated by coastal to deep marine conditions (including turbiditic successions). In the Late Cisuralian (stage 4), important differences in sedimentation patterns are registered for the western arc-related basins and eastern intraplate basins. The former were locally dominated by volcaniclastic sediments or marine deposits, and the intraplate basins are characterized by shallow marine conditions punctuated by several episodes of deltaic progradation. Finally, in the Late Permian (stage 5), volcanism and volcaniclastic sedimentation dominated in basins located along the western South American margin. The intraplate basins in turn were characterized by T-R cycles composed of shallow marine, deltaic, and fluvial siliciclastic deposits.

El mensaje de conservacion de las instalaciones restauradas del Instituto Internacional de Dasonomia Tropical

Treesearch

Ariel Lugo; J. Rullan

2015-01-01

Durante un periodo de aproximadamente 20 años, el Instituto Internacional de Dasonomía Tropical y sus colaboradores desarrollaron e implementaron un plan de instalaciones que abarcaba tanto las instalaciones nuevas, como las restauradas. Entre las instalaciones restauradas, el edificio histórico de la sede institucional recibió una Certificación Dorada por Liderazgo en...

Growth phenotypes of Pseudomonas aeruginosa lasR mutants adapted to the airways of cystic fibrosis patients

PubMed Central

D’Argenio, David A.; Wu, Manhong; Hoffman, Lucas R.; Kulasekara, Hemantha D.; Déziel, Eric; Smith, Eric E.; Nguyen, Hai; Ernst, Robert K.; Larson Freeman, Theodore J.; Spencer, David H.; Brittnacher, Mitchell; Hayden, Hillary S.; Selgrade, Sara; Klausen, Mikkel; Goodlett, David R.; Burns, Jane L.; Ramsey, Bonnie W.; Miller, Samuel I.

2009-01-01

Summary The opportunistic pathogen Pseudomonas aeruginosa undergoes genetic change during chronic airway infection of cystic fibrosis (CF) patients. One common change is a mutation inactivating lasR, which encodes a transcriptional regulator that responds to a homoserine lactone signal to activate expression of acute virulence factors. Colonies of lasR mutants visibly accumulated the iridescent intercellular signal 4-hydroxy-2-heptylquinoline. Using this colony phenotype, we identified P. aeruginosa lasR mutants that emerged in the airway of a CF patient early during chronic infection, and during growth in the laboratory on a rich medium. The lasR loss-of-function mutations in these strains conferred a growth advantage with particular carbon and nitrogen sources, including amino acids, in part due to increased expression of the catabolic pathway regulator CbrB. This growth phenotype could contribute to selection of lasR mutants both on rich medium and within the CF airway, supporting a key role for bacterial metabolic adaptation during chronic infection. Inactivation of lasR also resulted in increased β-lactamase activity that increased tolerance to ceftazidime, a widely used β-lactam antibiotic. Loss of LasR function may represent a marker of an early stage in chronic infection of the CF airway with clinical implications for antibiotic resistance and disease progression. PMID:17493132

The behaviour of linear alkyl benzene sulphonate under direct discharge conditions in Vientiane, Lao PDR.

PubMed

Whelan, M J; Van Egmond, R; Guymer, I; Lacoursière, J O; Vought, L M B; Finnegan, C; Fox, K K; Sparham, C; O'Connor, S; Vaughan, M; Pearson, J M

2007-12-01

Direct discharge of untreated sewage to surface waters is a common practice in many parts of the world. However, relatively little is known about the behaviour of synthetic organic pollutants under these conditions. This paper describes a sampling campaign designed to track changes in water quality in a surface water system in Vientiane (Lao PDR) receiving significant quantities of untreated waste water. The study was based on following in-channel transport using a fluorescent tracer injected as a pulse, with a focus on the anionic surfactant linear alkylbenzene sulphonate (LAS) and ammonia. Water samples were collected at a number of stations with sampling times estimated to coincide with solute time-of-travel. The reduction in LAS concentration with flow-time could be approximated by first-order kinetics with a half life of about 7 h. Free ammonia concentrations decreased more slowly than LAS and remained above the level believed to be toxic for sensitive aquatic species along the entire channel. Changes in the ratios of LAS alkyl chain homologues to total LAS concentrations suggest a preferential removal of longer chain lengths. The role of biodegradation in the removal of LAS was confirmed by the presence of LAS metabolites (sulphophenylcarboxylates, SPCs) which increased systematically (as a fraction of LAS remaining) with flow-time.

Estudio de la formación de galaxias espirales en un modelo de agregación jerárquica

NASA Astrophysics Data System (ADS)

Tissera, P.; Saiz, A.; Dominguez-Tenreiro, R.

El estudio de formación de galaxias espirales ha llevado al desarrollo de numerosos modelos teóricos (e.g. White & Rees 1978). En la actualidad, el modelo más aceptado predice la formación de una galaxia espiral a partir del colapso disipativo del gas en el pozo de potencial de un halo oscuro, conservando su momento angular específco (Fall & Efstathiou 1980). En los últimos años, ha sido posible realizar simulaciones numéricas hidrodinámicas, las cuales describen la evolución conjunta de la materia oscura y los bariones. Estos experimentos han señalado la dificultad de formar estructuras discoidales con propiedades consistentes con las observaciones, en modelos de agregación jerárquica. El problema principal se origina en la pérdida catastrófica de momento angular de la componente disipativa, durante el proceso de ensamblaje de los objetos, a través de la fusión de subestructura (Navarro & Steinmetz 1997). Estos experimentos no incluían procesos de formación estelar. En este trabajo, se expondrán resultados de simulaciones hidrodinámicas cosmológicas, incluyendo formación estelar (Tissera et al 1997), donde ha sido posible reproducir objetos discoidales con contrapartida observacional. El elemento fundamental ha sido la formación de bulbos estelares, los cuales han evitado la pérdida catastrófica de momento angular de los bariones. Se encontró que los discos exponenciales puramente gaseosos son altamente inestables y suceptibles de generar barras, responsables de la pérdida de momento angular y la caída violenta del gas hacia la región central. Estas inestabilidades son fácilmente inducidas durante interacciones y fusiones con objetos vecinos (Barnes & Hernquist 1996). Un bulbo estelar (o un objeto masivo y compacto) estabiliza el disco ante perturbaciones externas, asegurándole un potencial simétrico (Sellwood & Moore 1998, Van der Bosch 1998). En este caso, el gas en el disco no pierde completamente su momento angular intrínseco durante las fusiones, sino que, las sobrevive aportando una contribución distinta de cero, a partir de la cual el disco se regenera acretando en una segunda etapa, gas del halo de acuerdo al modelo tradicional de Fall & Efstathiou.

[Hermeneutic approach to ideas about conception, pregnancy and birth among the Pilago of the Central Chaco].

PubMed

Idoyaga Molina, A

1977-01-01

The processes of conception, gestation, and birth among the Pilaga Indians of the north central part of the Province of Formosa, Argentina, were studied in late 1975. The Pilaga have an empirical and mythic notion of the processes of gestation, but no true physiological concept. The idea of the uterus as an organ and its function are lacking. The womb is regarded as a bag in which the embryo develops. The baby develops and grows through successive deposits of semen, which also cause the placenta to be created. Native opinions vary as to the chronology of development of different parts of the body. The death of an embryo is believed to result from intentional damage inflicted by a shaman or spirit. Conception and pregnancy are believed to result from intervention of spirits called payak acting in concert with human actions. The Pilaga consult shamans, preferably in the family, in order to assure the good will of the payak. The souls of children to be born are sent to the mother's body. The payak provide men with supplemental strength so that their forces will not be exhausted in coitus. Twin births are believed to result from the bad intentions of the payak. It is not believed possible to develop more than 1 embryo at a time because of the diminution of physical strength caused by loss of vital fluids in each ejaculation. The second and subsequent infants in multiple births are considered children of the payak and must be eliminated. Sterility is always attributed to the female and may be due to her requests to a payak to intercede and prevent pregnancy or to bad intentions of a payak, which comes in the form of a small insect and ties off her womb so that the embryo cannot receive the successive deposits of semen that cause it to develop. Sterility can sometimes be cured by intervention of a shaman, if the payak can be persuaded to leave the woman alone. Otherwise sterility is cause for breakup of a marriage. The cultural ideal is to have a son first and then to have an equal number of sons and daughters. Both parents must observe a variety of dietary and other tabus during the pregnancy. The woman must not leave the house lot by herself in the prenatal and postnatal periods for fear that the payak will harm her. If she briefly goes out, she must disguise herself head to toe and must be accompained by her mother or grandmother. An older widow assists in the birth according to techniques laid down by the first humans in ancient times. Care of the umbilicus, burial of the placenta, and washing of the newborn and mother are especially surrounded by danger and must be carefully done so as to prevent harm to either.

Evolución en el tiempo de las relaciones Masa-Luminosidad y Corrección Bolométrica y Temperatura Efectiva contra Índice de Color

NASA Astrophysics Data System (ADS)

Miloni, L. A.; Camperi, J. A.

Analizamos la evolución que en los últimos 70 años han tenido las relaciones M-L, BC vs CI y Teff vs CI. Se discuten las causas de esa evolución, se trata de incorporar los valores más modernos disponibles discutiendo su calidad y se deducen las relaciones que actualmente deberían ser las más confiables. Destacamos los puntos en los que estas relaciones continúan estando pobremente definidas y sería deseable mejorar en el futuro próximo.

Sensitivity of two Iberian lakes to North Atlantic atmospheric circulation modes

NASA Astrophysics Data System (ADS)

Hernández, Armand; Trigo, Ricardo M.; Pla-Rabes, Sergi; Valero-Garcés, Blas L.; Jerez, Sonia; Rico-Herrero, Mayte; Vega, José C.; Jambrina-Enríquez, Margarita; Giralt, Santiago

2015-12-01

The North Atlantic Oscillation (NAO) exerts a major influence on the climate of the North Atlantic region. However, other atmospheric circulation modes (ACMs), such as the East Atlantic (EA) and Scandinavian (SCAND) patterns, also play significant roles. The dynamics of lakes on the Iberian Peninsula are greatly controlled by climatic parameters, but their relationship with these various ACMs has not been investigated in detail. In this paper, we analyze monthly meteorological and limnological long-term datasets (1950-2011 and 1992-2011, respectively) from two lakes on the northern and central Iberian Peninsula (Sanabria and Las Madres) to develop an understanding of the seasonal sensitivity of these freshwater systems to the NAO, EA and SCAND circulation modes. The limnological variability within Lake Sanabria is primarily controlled by fluctuations in the seasonal precipitation and wind, and the primary ACMs associated with the winter limnological processes are the NAO and the SCAND modes, whereas only the EA mode appears to weakly influence processes during the summer. However, Lake Las Madres is affected by precipitation, wind and, to a lesser extent, temperature, whereas the ACMs have less influence. Therefore, we aim to show that the lakes of the Iberian Peninsula are sensitive to these ACMs. The results presented here indicate that the lake dynamics, in some cases, have a higher sensitivity to variations in the ACMs than single local meteorological variables. However, certain local features, such as geography, lake morphology and anthropic influences, are crucial to properly record the signals of these ACMs.

Lithium- and boron-bearing brines in the Central Andes: exploring hydrofacies on the eastern Puna plateau between 23° and 23°30'S

NASA Astrophysics Data System (ADS)

Steinmetz, R. L. López

2017-01-01

Internally drained basins of the Andean Plateau are lithium- and boron-bearing systems. The exploration of ionic facies and parental links in a playa lake located in the eastern Puna (23°-23°30'S) was assessed by hydrochemical determinations of residual brines, feed waters and solutions from weathered rocks. Residual brines have been characterized by the Cl- (SO4 =)/Na+ (K+) ratio. Residual brines from the playa lake contain up to 450 mg/l of boron and up to 125 mg/l of lithium, and the Las Burras River supplies the most concentrated boron (20 mg/l) and lithium (3.75 mg/l) inflows of the basin. The hydro-geochemical assessment allowed for the identification of three simultaneous sources of boron: (1) inflow originating from granitic areas of the Aguilar and Tusaquillas ranges; (2) weathering of the Ordovician basement; and (3) boron-rich water from the Las Burras River. Most of the lithium input of the basin is likely generated by present geothermal sources rather than by weathering and leaching of ignimbrites and plutonic rocks. However, XRD analyses of playa lake sediments revealed the presence of lithian micas of clastic origin, including taeniolite and eucriptite. This study is the first to document these rare Li-micas from the Puna basin. Thus, both residual brines and lithian micas contribute to the total Li content in the studied hydrologic system.

Introduction of non-native marine fish species to the Canary Islands waters through oil platforms as vectors

NASA Astrophysics Data System (ADS)

Pajuelo, José G.; González, José A.; Triay-Portella, Raül; Martín, José A.; Ruiz-Díaz, Raquel; Lorenzo, José M.; Luque, Ángel

2016-11-01

This work documents the introduction of non-native fish species to the Canary Islands (central-eastern Atlantic) through oil rigs. Methodological approaches have included surveys by underwater visual censuses around and under oil platforms and along the docking area of rigs at the Port of Las Palmas. Eleven non-native fish species were registered. Paranthias furcifer, Abudefduf hoefleri, Acanthurus bahianus, Acanthurus chirurgus, and Acanthurus coeruleus are first recorded from the Canaries herein. Other three species could not be identified, although they have never been observed in the Canaries. Cephalopholis taeniops, Abudefduf saxatilis, and Acanthurus monroviae had been previously recorded. Native areas of these species coincide with the areas of origin and the scale of oil rigs with destination the Port of Las Palmas. The absence of native species in the censuses at rigs and their presence at rigs docking area, together with the observation of non-native species after the departure of platforms, reject the possibility that these non-native species were already present in the area introduced by another vector. C. taeniops, A. hoefleri, A. saxatilis, A. chirurgus, A. coeruleus and A. monroviae are clearly seafarer species. A. bahianus seems to be a potential seafarer species. P. furcifer is a castaway species. For the moment, the number of individuals of the non-native species in marine ecosystems of the Canaries seems to be low, and more investigation is needed for controlling these translocations.

Trace Determination of Linear Alkylbenzene Sulfonates: Application in Artificially Polluted Soil—Carrots System

PubMed Central

Sablayrolles, Caroline; Montréjaud-Vignoles, Mireille; Silvestre, Jérôme; Treilhou, Michel

2009-01-01

Surfactants are widely used in household and industrial products. The risk of incorporation of linear alkylbenzene sulfonates (LAS) from biosolids, wastewater, and fertilizers land application to the food chain is being assessed at present by the European Union. In the present work, a complete analytical method for LAS trace determination has been developed and successfully applied to LAS (C10–C13) uptake in carrot plants used as model. These carrots were grown in soil with the trace organics compounds added directly into the plant containers in pure substances form. LAS trace determination (μg kg−1 dry matter) in carrots samples was achieved by Soxtec apparatus and high-performance liquid chromatography-fluorescence detection. The methodology developed provides LAS determination at low detection limits (5 μg kg−1 dry matter) for carrot sample (2 g dry matter) with good recoveries rate (>90%). Transfer of LAS has been followed into the various parts of the carrot plant. LAS are generally found in the carrot leaves and percentage transfer remains very low (0.02%). PMID:20107562

Influence of linear alkylbenzene sulfonate (LAS) on the structure of Alphaproteobacteria, Actinobacteria, and Acidobacteria communities in a soil microcosm.

PubMed

Sánchez-Peinado, M del Mar; González-López, Jesús; Martínez-Toledo, M Victoria; Pozo, Clementina; Rodelas, Belén

2010-03-01

Linear alkylbenzene sulfonate (LAS) is the most used anionic surfactant in a worldwide scale and is considered a high-priority pollutant. LAS is regarded as a readily biodegradable product under aerobic conditions in aqueous media and is mostly removed in wastewater treatment plants, but an important fraction (20-25%) is immobilized in sewage sludge and persists under anoxic conditions. Due to the application of the sludge as a fertilizer, LAS reaches agricultural soil, and therefore, microbial toxicity tests have been widely used to evaluate the influence of LAS on soil microbial ecology. However, molecular-based community-level analyses have been seldom applied in studies regarding the effects of LAS on natural or engineered systems, and, to our knowledge, there are no reports of their use for such appraisals in agricultural soil. In this study, a microcosm system is used to evaluate the effects of a commercial mixture of LAS on the community structure of Alphaproteobacteria, Actinobacteria, and Acidobacteria in an agricultural soil. The microcosms consisted of agricultural soil columns (800 g) fed with sterile water (8 ml h(-1)) added of different concentration of LAS (10 or 50 mg l(-1)) for periods of time up to 21 days. Sterile water was added to control columns for comparison. The structures of Alphaproteobacteria, Actinobacteria, and Acidobacteria communities were analyzed by a cultivation independent method (temperature gradient gel electrophoresis (TGGE) separation of polymerase chain reaction (PCR)-amplified partial 16S rRNA genes). Relevant populations were identified by subsequent reamplification, DNA sequencing, and database comparisons. Cluster analysis of the TGGE fingerprints taking into consideration both the number of bands and their relative intensities revealed that the structure of the Alphaproteobacteria community was significantly changed in the presence of LAS, at both concentrations tested. The average number of bands was significantly lower in the microcosms receiving 50 mg l(-1) LAS and in the lower portion of soil cores. The clear differentiation of the samples of the upper portion of the soil columns amended with LAS was specifically related to the presence and intensity of a distinctive major band (named band class 7). There was a statistically significant positive correlation between the concentrations of LAS detected in soil portions taken from LAS 10 mg l(-1) and LAS 50 mg l(-1) microcosms and the relative intensity of band class 7 in the corresponding TGGE profiles. Prevalent Alphaproteobacteria populations in the soil microcosms had close similarity (>99%) to cultivated species affiliated to genera of the Rhizobiaceae, Methylocystaceae, Hyphomicrobiaceae, Rhodospirillaceae, Brucellaceae, Bradyrhizobiaceae, and Caulobacteraceae families. The population represented by band class 7 was found closely related to the genus Phenylobacterium (Caulobacteraceae). According to cluster analysis of TGGE profiles, the structure of both Actinobacteria and Acidobacteria communities in the soil microcosms was remarkably stable in the presence of LAS at the two concentrations tested, as most bands were universally present in all samples and displayed fairly similar relative intensities. Previous studies by others authors, based on biological and chemical tests, concluded that LAS toxicity was not an important microbial selection factor in sludge amended soil, while work based on the use of molecular fingerprinting to evaluate the impact of LAS in aqueous media and marine sediments showed that concentrations as low as 1 mg l(-1) significantly influence the development of the bacterial community structure. Although TGGE is not a strictly quantitative method due to the bias introduced by the PCR reaction, changes of band intensity through experiments are a consequence of a change in the relative abundance of the corresponding populations in the community and can be used as a semiquantitative measure of bacterial diversity. Our results evidence that the Phenylobacterium population represented by band class 7 was favored by the presence of increasing concentrations of LAS in the soil and turned into a dominant population, suggesting its possible ability to use LAS in soil as a source of nutrients. As studies with pure cultures are required to confirm the ability of this population to degrade LAS, isolation strategies are currently under development in our laboratory. The weak effect of LAS on the structure of Actinobacteria and Acidobacteria communities is particularly interesting, as to our knowledge, there are no previous reports regarding the effects of LAS on these bacterial groups in soil. CONCLUSIONS, RECOMMENDATIONS, AND PERSPECTIVES: The Phenylobacterium-related alphaproteobacterial population identified in this work was selectively enriched in LAS polluted soil and is a plausible candidate to play a relevant role in the biotransformation of the surfactant under the conditions tested. The surfactant had no remarkable effects on the Actinobacteria and Acidobacteria fingerprints in soil, even when present at concentrations widely exceeding those reached in soil immediately after sludge application. TGGE fingerprinting provides a reliable and low time-consuming method for the monitoring of the bacterial community structure and dynamics, and we recommend its integration with the biological and chemical analyses usually applied in risk assessment of LAS in the environment.

City of Las Vegas Plug-in Hybrid Electric Vehicle Demonstration Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2013-12-31

The City of Las Vegas was awarded Department of Energy (DOE) project funding in 2009, for the City of Las Vegas Plug-in Hybrid Electric Vehicle Demonstration Program. This project allowed the City of Las Vegas to purchase electric and plug-in hybrid electric vehicles and associated electric vehicle charging infrastructure. The City anticipated the electric vehicles having lower overall operating costs and emissions similar to traditional and hybrid vehicles.

Launch Abort System Flight Test Overview

NASA Technical Reports Server (NTRS)

Williams-Hayes, Peggy; Bosworth, John T.

2007-01-01

This viewgraph presentation is an overview of the Launch Abort System (LAS) for the Constellation Program. The purpose of the paper is to review the planned tests for the LAS. The program will evaluate the performance of the crew escape functions of the Launch Abort System (LAS) specifically: the ability of the LAS to separate from the crew module, to gather flight test data for future design and implementation and to reduce system development risks.

Beyond Lecture and Non-Lecture Classrooms: LA-student interactions in Active Learning Classrooms

NASA Astrophysics Data System (ADS)

Gonzalez, Dayana; Kornreich, Hagit; Rodriguez, Idaykis; Monslave, Camila; Pena-Flores, Norma

Our expanded multi-site study on active learning classrooms supported by Learning Assistants (LAs) aims to understand the connections between three classroom elements: the activity, student learning, and how LAs support the learning process in the classroom. At FIU, LAs are used in a variety of active learning settings, from large auditorium settings to studio classroom with movable tables. Our study uses the COPUS observation protocol as a way to characterize LAs behaviors in these classrooms. With a focus on LA-student interactions, our analysis of how LAs interact with students during a 'learning session' generated new observational codes for specific new categories of LA roles. Preliminary results show that LAs spend more time interacting with students in some classes, regardless of the classroom setting, while in other classrooms, LA-student interactions are mostly brief. We discuss how LA-student interactions contribute to the dynamics and mechanism of the socially shared learning activity.

Are Learning Assistants Better K-12 Science Teachers?

NASA Astrophysics Data System (ADS)

Gray, Kara E.; Webb, David C.; Otero, Valerie K.

2010-10-01

This study investigates how the undergraduate Learning Assistant (LA) experience affects teachers' first year of teaching. The LA Program provides interested science majors with the opportunity to explore teaching through weekly teaching responsibilities, an introduction to physics education research, and a learning community within the university. Some of these LAs are recruited to secondary science teacher certification programs. We hypothesized that the LA experience would enhance the teaching practices of the LAs who ultimately become teachers. To test this hypothesis, LAs were compared to a matched sample of teachers who completed the same teacher certification program as the LAs but did not have the LA "treatment." LAs and "non-LAs" were compared through interviews, classroom observations, artifact packages, and observations made with Reformed Teacher Observation Protocol (RTOP) collected within the first year of teaching. Some differences were found; these findings and their implications are discussed.

Kinetics of methane production and biodegradation of linear alkylbenzene sulfonate from laundry wastewater.

PubMed

Motteran, Fabrício; Braga, Juliana K; Silva, Edson L; Varesche, Maria Bernadete A

2016-12-05

This study evaluates the kinetics of methane production and degradation of standard linear alkylbenzene sulfonate (LAS) (50 ± 3.5 mg/L) and LAS from laundry wastewater (85 ± 2.1 mg/L) in anaerobic batch reactors at 30°C with different sources of inoculum. The inocula were obtained by auto-fermentation (AFM) and UASB reactors from wastewater treatment of poultry slaughterhouse (SGH), swine production (SWT) and wastewater treatment thermophilic of sugarcane industry (THR). The study was divided into three phases: synthetic substrate (Phase I), standard LAS (Phase II) and LAS from laundry wastewater (Phase III). For SGH, the highest values for cumulative methane productions (1,844.8 ± 149 µmol-Phase II), methane production rate (70.8 ± 88 µmol/h-Phase II and 4.01 ± 07 µmol/h-Phase III) were observed. The use of thermophilic biomass (THR) incubated at 30°C was not favorable for methane production and LAS biodegradation, but the highest kinetic coefficient degradation (k 1 app ) was obtained for LAS (0.33 ± 0.3 h) compared with mesophilic biomass (SGH and SWT) (0.13 ± 0.02 h). Therefore, both LAS sources influenced the kinetics of methane production and organic matter degradation. For SGH, inoculum obtained the highest LAS degradation. In the SGH inoculum sequenced by MiSeq-Illumina was identified genera (VadinCA02, Candidatus Cloacamonas, VadinHB04, PD-UASB-13) related to degrade toxic compounds. Therefore, it recommended the reactor mesophilic inoculum UASB (SGH) for the LAS degradation.

Estudio de la galaxia peculiar NGC 1487

NASA Astrophysics Data System (ADS)

Agüero, E. L.; Paolantonio, S.; Gunthardt, G.

La galaxia peculiar NGC 1487, cuya morfología sugiere un evento de ``merging" o interacción próxima, es estudiada en base a material observacional espectroscópico y fotométrico obtenido en el CASLEO. Mediante técnicas espectrofotométricas standards se determinan las principales características espectrales, los mecanismos de excitación actuantes, las condiciones físicas y las velocidades radiales de las estructuras conspicuas de la galaxia. Por otra parte, usando imágenes directas en las bandas B, V, R e I, se obtienen distribuciones detalladas de los colores B-V, V-R y R-I y detalles de su morfología.

Estrategia de Aprendizaje Basado en Problemas (ABP) para explorar las concepciones alternativas relacionadas al tema estados de agregacion de la materia en estudiantes de nivel elemental =

NASA Astrophysics Data System (ADS)

Rosado Olivieri, Wilda Y.

Gran parte de la investigacion acerca de la ensenanza de las ciencias se dedica a estudiar la forma o manera en que los estudiantes visualizan los conceptos cientificos. Para Driver (1983) esas ideas o concepciones se conocen como concepciones alternativas; las cuales pueden ocasionar dificultad para comprender los conceptos de las diferentes areas del conocimiento. El proposito de este estudio fue: (a) indagar como las distintas etapas del ABP permiten explorar las concepciones alternativas que poseen los estudiantes de nivel elemental acerca de los estados de agregacion de la materia y, (b) explorar en que medida el ABP permite identificar e incorporar las concepciones alternativas que poseen los estudiantes de nivel elemental con relacion al concepto de estados de agregacion de la materia para facilitar su aprendizaje. Con el fin de explorar las concepciones alternativas en el tema de los estados agregados de la materia se implanto la estrategia de Aprendizaje Basado en Problemas (ABP) con estudiantes de quinto grado de nivel elemental. Se utilizo la metodologia mixta con varias estrategias de recopilacion de datos, como una pre y pos prueba para elucidar el conocimiento previo y al mismo tiempo las concepciones alternativas sobre el tema bajo estudio y luego verificar el aprendizaje en los estudiantes. Asimismo, el uso de mapas conceptuales para determinar la profundidad del tema estudiado y el entrelazamiento de los conceptos Una tercera estrategia fue el grupo focal para tomar en cuenta la impresion de los estudiantes acerca del proyecto ABP. El aspecto colaborativo y cooperativo fue un factor fundamental, ya que el aprendizaje ocurrio en ese contexto educativo. Para los hallazgos de esta investigacion fue tan importante el conocimiento previo como los procesos que se generaban para que la adquisicion del mismo fuera de forma significativa y funcional (Escribano & Del Valle, 2010). La estrategia de ABP constituyo en este estudio una forma para indagar las concepciones alternativas que poseian los estudiantes y a su vez, determinar como el estudiante manejaba dichas concepciones a situaciones que requeririan aplicar su conocimiento para luego modificar las estructuras conceptuales hacia el conocimiento cientifico.

Water-level data from wells and test holes through 1991 and potentiometric contours as of 1991 for Yucca Flat, Nevada Test Site, Nye County, Nevada

USGS Publications Warehouse

Hale, Glenn S.; Trudeau, Douglas A.; Savard, Charles S.

1995-01-01

The underground nuclear-testing program of the U.S. Department of Energy takes place at the Nevada Test Site, about 65 miles northwest of Las Vegas, Nev. Water levels in Yucca Flat may be affected by underground nuclear testing. The purpose of this map report is to present water-level data collected from wells and test holes through December 1991, and to present potentiometric contours representing 1991 water-table conditions in Yucca Flat. Water-level data from 91 sites are shown on the map and include information from 54 sites shown on a 1983 map. Water levels ranged from 519.5 to 2,162.9-feet below land surface. Potentiometric contours are drawn from water-level data to represent the altitude of the water table. Water-level altitudes ranged from about 2,377 ft to 2,770 ft above sea level in the central part of Yucca Flat and from about 4,060 ft to 2,503 ft above sea level in the western and northern parts of Yucca Flat. The water-level data were contoured considering the hydrologic setting, including the concept that water levels within the Cenozoic hydrologic units in the central part of the study area are elevated with respect to water levels in the adjacent and underlying Paleozoic hydrologic units. The most notable feature in the central part of the area is the presence of four ground-water mounds not shown on the 1983 map.

First North American fossil monkey and early Miocene tropical biotic interchange

NASA Astrophysics Data System (ADS)

Bloch, Jonathan I.; Woodruff, Emily D.; Wood, Aaron R.; Rincon, Aldo F.; Harrington, Arianna R.; Morgan, Gary S.; Foster, David A.; Montes, Camilo; Jaramillo, Carlos A.; Jud, Nathan A.; Jones, Douglas S.; MacFadden, Bruce J.

2016-05-01

New World monkeys (platyrrhines) are a diverse part of modern tropical ecosystems in North and South America, yet their early evolutionary history in the tropics is largely unknown. Molecular divergence estimates suggest that primates arrived in tropical Central America, the southern-most extent of the North American landmass, with several dispersals from South America starting with the emergence of the Isthmus of Panama 3-4 million years ago (Ma). The complete absence of primate fossils from Central America has, however, limited our understanding of their history in the New World. Here we present the first description of a fossil monkey recovered from the North American landmass, the oldest known crown platyrrhine, from a precisely dated 20.9-Ma layer in the Las Cascadas Formation in the Panama Canal Basin, Panama. This discovery suggests that family-level diversification of extant New World monkeys occurred in the tropics, with new divergence estimates for Cebidae between 22 and 25 Ma, and provides the oldest fossil evidence for mammalian interchange between South and North America. The timing is consistent with recent tectonic reconstructions of a relatively narrow Central American Seaway in the early Miocene epoch, coincident with over-water dispersals inferred for many other groups of animals and plants. Discovery of an early Miocene primate in Panama provides evidence for a circum-Caribbean tropical distribution of New World monkeys by this time, with ocean barriers not wholly restricting their northward movements, requiring a complex set of ecological factors to explain their absence in well-sampled similarly aged localities at higher latitudes of North America.

First North American fossil monkey and early Miocene tropical biotic interchange.

PubMed

Bloch, Jonathan I; Woodruff, Emily D; Wood, Aaron R; Rincon, Aldo F; Harrington, Arianna R; Morgan, Gary S; Foster, David A; Montes, Camilo; Jaramillo, Carlos A; Jud, Nathan A; Jones, Douglas S; MacFadden, Bruce J

2016-05-12

New World monkeys (platyrrhines) are a diverse part of modern tropical ecosystems in North and South America, yet their early evolutionary history in the tropics is largely unknown. Molecular divergence estimates suggest that primates arrived in tropical Central America, the southern-most extent of the North American landmass, with several dispersals from South America starting with the emergence of the Isthmus of Panama 3-4 million years ago (Ma). The complete absence of primate fossils from Central America has, however, limited our understanding of their history in the New World. Here we present the first description of a fossil monkey recovered from the North American landmass, the oldest known crown platyrrhine, from a precisely dated 20.9-Ma layer in the Las Cascadas Formation in the Panama Canal Basin, Panama. This discovery suggests that family-level diversification of extant New World monkeys occurred in the tropics, with new divergence estimates for Cebidae between 22 and 25 Ma, and provides the oldest fossil evidence for mammalian interchange between South and North America. The timing is consistent with recent tectonic reconstructions of a relatively narrow Central American Seaway in the early Miocene epoch, coincident with over-water dispersals inferred for many other groups of animals and plants. Discovery of an early Miocene primate in Panama provides evidence for a circum-Caribbean tropical distribution of New World monkeys by this time, with ocean barriers not wholly restricting their northward movements, requiring a complex set of ecological factors to explain their absence in well-sampled similarly aged localities at higher latitudes of North America.

Información básica sobre los arrecifes de coral

EPA Pesticide Factsheets

Los corales están en todos los océanos del mundo, tanto en las aguas superficiales como en las profundas. Tienen una relación simbiótica con las algas, necesitan aguas transparentes, superficiales, que

Observación espectroscópica de NGC 2442

NASA Astrophysics Data System (ADS)

Agüero, E.; Bajaja, E.; Paolantonio, S.

La galaxia NGC 2442 (SAB(s)bc pec) fue observada con el telescopio de 2,15 m y el espectrógrafo REOSC del CASLEO utilizando el detector CCD Tektronix de 1024 × 1024 pixels de 24 μ m (0,26"). Las exposiciones fueron realizadas con la ranura de 3,3'' × 348'', en el plano focal, ubicadas en seis posiciones, cinco a 40o de áng. de pos. y una a 79o. La mayor parte de las exposiciones se efectuó con la red de 1200 líneas mm-1, a un ángulo de 25,53o cubriendo el rango de λλ 6200 a 6900 con dispersión de 32Å mm-1 y resolución de 2,5 Å. Las relaciones entre las intensidades de las líneas de emisión en el núcleo de NGC 2442 indican que es un LINER lo cual es compatible con la sugerencia de Shobrook de que se trataría de una galaxia Seyfert u otro tipo de galaxia activa. La temperatura y densidad electrónicas nucleares son Te ~14.000 K y Ne ~ 530 cm-3, respectivamente. Una región a 87'' al NE en cambio, donde las intensidades son también altas, presenta características espectrales típicas de una Región HII con Te ~6500 K y Ne ~10 cm-3. La correlación de las intensidades con el CO en 115 GHz y con el continuo en 843 MHz y de las velocidades ópticas con las del CO, a lo largo del eje mayor, son muy buenas. La mayor resolución angular de las observaciones, sin embargo, permite apreciar la existencia de dos componentes de velocidad en el núcleo que pueden corresponder a un anillo en rotación o a un fenómeno de expansión.

Deep Imaging of Eridanus II and Its Lone Star Cluster

NASA Astrophysics Data System (ADS)

Crnojević, D.; Sand, D. J.; Zaritsky, D.; Spekkens, K.; Willman, B.; Hargis, J. R.

2016-06-01

We present deep imaging of the most distant dwarf discovered by the Dark Energy Survey, Eridanus II (Eri II). Our Magellan/Megacam stellar photometry reaches ˜3 mag deeper than previous work and allows us to confirm the presence of a stellar cluster whose position is consistent with Eri II’s center. This makes Eri II, at {M}V=-7.1, the least luminous galaxy known to host a (possibly central) cluster. The cluster is partially resolved, and at {M}V=-3.5 it accounts for ˜4% of Eri II’s luminosity. We derive updated structural parameters for Eri II, which has a half-light radius of ˜280 pc and is elongated (ɛ ˜ 0.48) at a measured distance of D ˜ 370 kpc. The color-magnitude diagram displays a blue, extended horizontal branch, as well as a less populated red horizontal branch. A central concentration of stars brighter than the old main-sequence turnoff hints at a possible intermediate-age (˜3 Gyr) population; alternatively, these sources could be blue straggler stars. A deep Green Bank Telescope observation of Eri II reveals no associated atomic gas. This paper includes data gathered with the 6.5 m Magellan Telescopes at Las Campanas Observatory, Chile.

LAS0811: from combinatorial chemistry to activation of antioxidant response element.

PubMed

Zhu, Ming; Baek, Hyounggee; Liu, Ruiwu; Song, Aimin; Lam, Kit; Lau, Derick

2009-01-01

The antioxidant response element (ARE) and its transcription factor, nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), are potential targets for cancer chemoprevention. We sought to screen small molecules synthesized with combinatorial chemistry for activation of ARE. By high-throughput screening of 9400 small molecules from 10 combinatorial chemical libraries using HepG2 cells with an ARE-driven reporter, we have identified a novel small molecule, 1,2-dimethoxy-4,5-dinitrobenzene (LAS0811), as an activator of the ARE. LAS0811 upregulated the activity of NAD(P)H:quinone oxidoreductase 1 (NQO1), a representative antioxidative enzyme regulated by ARE. It enhanced production of an endogenous reducing agent, glutathione (GSH). In addition, LAS0811 induced expression of heme oxygenase 1 (HO1), which is an ARE-regulated enzyme with anti-inflammatory activity. Furthermore, LAS0811 reduced cell death due to the cytotoxic stress of a strong oxidant, t-butyl hydroperoxide (t-BOOH). Mechanistically, LAS0811 upregulated the expression of Nrf2 and promoted its translocation into the nuclei leading to subsequent ARE activation. Taken together, LAS0811 is a novel activator of the ARE and its associated detoxifying genes and, thus, a potential agent for cancer chemoprevention.

LAS0811: From Combinatorial Chemistry to Activation of Antioxidant Response Element

PubMed Central

Zhu, Ming; Baek, Hyounggee; Liu, Ruiwu; Song, Aimin; Lam, Kit; Lau, Derick

2009-01-01

The antioxidant response element (ARE) and its transcription factor, nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), are potential targets for cancer chemoprevention. We sought to screen small molecules synthesized with combinatorial chemistry for activation of ARE. By high-throughput screening of 9400 small molecules from 10 combinatorial chemical libraries using HepG2 cells with an ARE-driven reporter, we have identified a novel small molecule, 1,2-dimethoxy-4,5-dinitrobenzene (LAS0811), as an activator of the ARE. LAS0811 upregulated the activity of NAD(P)H:quinone oxidoreductase 1 (NQO1), a representative antioxidative enzyme regulated by ARE. It enhanced production of an endogenous reducing agent, glutathione (GSH). In addition, LAS0811 induced expression of heme oxygenase 1 (HO1), which is an ARE-regulated enzyme with anti-inflammatory activity. Furthermore, LAS0811 reduced cell death due to the cytotoxic stress of a strong oxidant, t-butyl hydroperoxide (t-BOOH). Mechanistically, LAS0811 upregulated the expression of Nrf2 and promoted its translocation into the nuclei leading to subsequent ARE activation. Taken together, LAS0811 is a novel activator of the ARE and its associated detoxifying genes and, thus, a potential agent for cancer chemoprevention. PMID:19794825

Edades relativas de cúmulos globulares

NASA Astrophysics Data System (ADS)

Miller Bertolami, M.; Forte, J. C.

El trabajo de Rossemberg et al (1999), estudia las edades relativas de cúmulos globulares galácticos mediante el análisis de ciertos parámetros morfológicos de los diagramas color-magnitud de dichos cúmulos. Este trabajo se centra en tres puntos: analizar la consistencia de los resultados obtenidos por Rossemberg et al (1999) al emplear observaciones en el sistema fotométrico de Washington, más precisamente, las magnitudes C y T1 en lugar de las magnitudes V e I utilizadas por dichos autores. De la existencia de colores integrados, metalicidad y edad (relativa) para 21 de los cúmulos utilizados en dicho trabajo, se analiza la consistencia de estos resultados con las dependencias de color integrado como función de la edad y la metalicidad que se desprenden de los modelos teóricos de luz integrada por Worthey (1994), Schulz (2002) y Lee et al (2002). Por último se lleva a cabo una breve comparación de la morfología de los diagramas color-magnitud de los cúmulos globulares y de las isocronas utilizadas, a fin de intentar identificar algunas de las posibles causas de las diferencias observadas en los incisos anteriores.

Acerca de las ratas y los ratones

EPA Pesticide Factsheets

Hay muchas especies de roedores, entre ellas, la ardilla, la ardilla listada, el castor, el perro de la pradera, la rata y el ratón. Se puede ver las medidas más importantes para eliminar y prevenir las infestaciones causadas por roedores.

Como Promover el Exito de las Ninas y las Minorias en las Ciencias y en las Matematicas. Para Padres/sobre Padres (How To Promote the Science and Mathematics Achievement of Females and Minorities. For Parents/about Parents).

ERIC Educational Resources Information Center

Schwartz, Wendy

Some minority and female students traditionally have not been given the help they need to enroll and succeed in mathematics and science classes. Now, however, various approaches are available to give these students the extra attention they need. Parents can help children develop an interest in science and mathematics by: (1) identifying role…

La Aventura de las Partículas

Science.gov Websites

ciertas formas fundamentales. Explore las siguientes rutas que le explicarán la materia del universo! La grande del logo de la Ruta SM) La ruta de las evidencias experimentales : aprenda como los físicos diseà explicación de los "por qué" de las interacciones físicas hay todavía muchos misterios por

Effects and risk assessment of linear alkylbenzene sulfonates in agricultural soil. 1. Short-term effects on soil microbiology.

PubMed

Elsgaard, L; Petersen, S O; Debosz, K

2001-08-01

Linear alkylbenzene sulfonates (LAS) may occur in sewage sludge that is applied to agricultural soil, in which LAS can be inhibitory to biological activity. As a part of a broader risk assessment of LAS in the terrestrial environment, we tested the short-term effects of aqueous LAS on microbial parameters in a sandy agricultural soil that was incubated for up to 11 d. The assays included 10 microbial soil parameters; ethylene degradation; potential ammonium oxidation; potential dehydrogenase activity; beta-glucosidase activity; iron reduction; the populations of cellulolytic bacteria, fungi and actinomycetes; the basal soil respiration; and the phospholipid fatty acid (PLFA) content. Except for beta-glucosidase activity, basal respiration, and total PLFA content, all soil parameters were sensitive to LAS, with EC10 values in the range of less than 8 to 22 mg/kg dry weight. This probably reflected a similar mode of LAS toxicity, ascribed to cell membrane interactions, and showed that sensitivity to LAS was common for various soil microorganisms. The extracellular beta-glucosidase activity was rather insensitive to LAS (ECI10, 47 mg/kg dry wt), whereas the basal soil respiration was not inhibited even at 793 mg/kg dry weight. This was interpreted as a combined response of inhibited and stimulated compartments of the microbial community. The PLFA content, surprisingly, showed no decrease even at 488 mg/kg. In conclusion, LAS inhibited specific microbial activities, although this could not be deduced from the basal respiration or the total PLFA content. The lowest EC10 values for microbial soil parameters were slightly higher than the predicted no-effect concentrations recently derived for plants and soil fauna (approximately 5 mg/kg dry wt).

Continuous measurements of water vapor isotopic compositions using an integrated cavity output spectrometer: calibrations and applications

NASA Astrophysics Data System (ADS)

Wang, L.; Caylor, K.; Dragoni, D.

2009-04-01

The 18O and 2H of water vapor can be used to investigate couplings between biological processes (e.g., photosynthesis or transpiration) and hydrologic processes (e.g., evaporation) and therefore serve as powerful tracers in hydrological cycles. A typical method for determining δ18O and δ2H fluxes in landscapes is a "Keeling Plot" approach, which uses field-collected vapor samples coupled with a traditional isotope ratio mass spectrometer to infer the isotopic composition of evapotranspiration. However, fractionation accompanying inefficient vapor trapping can lead to large measurement uncertainty and the intensive laboring involved in cold-trap make it almost impossible for continuous measurements. Over the last 3-4 years a few groups have developed continuous approaches for measuring δ18O and δ2H that use laser absorption spectroscopy (LAS) to achieve accuracy levels similar to lab-based mass spectrometry methods. Unfortunately, most LAS systems need cryogenic cooling, constant calibration to a reference gas, and substantial power requirements, which make them unsuitable for long-term field deployment at remote field sites. In this research, we tested out a new LAS-based water vapor isotope analyzer (WVIA, Los Gatos Research, Inc, Mountain View, CA) based on Integrated Cavity Output Spectroscopy (ICOS) and coupled this instrument with a flux gradient system. The WVIA was calibrated bi-weekly using a dew point generator and water with known δ18O and δ2H signatures. The field work was performed at Morgan-Monroe State Forest Ameriflux tower site (central Indiana) between August 8 and August 27, 2008. The combination method was able to produce hourly δ18O and δ2H fluxes data with reproducibility similar to lab-based mass spectrometry methods. Such high temporal resolution data were also able to capture signatures of canopy and bare soil evaporation to individual rainfall events. The use of the ICOS water vapor analyzer within a gradient system has the potential to greatly expand the use of continuous δ18O and δ2H fluxes measurements to address a wide range of ecohydrological research topics.

Measuring hourly 18O and 2H fluxes in a mixed hardwood forest using an integrated cavity output spectrometer

NASA Astrophysics Data System (ADS)

Wang, L.; Caylor, K.; Dragoni, D.

2008-12-01

The 18O and 2H of water vapor can be used to investigate couplings between biological processes (e.g., photosynthesis or transpiration) and hydrologic processes (e.g., evaporation) and therefore serve as powerful tracers in hydrological cycles. A typical method for determining δ18O and δ2H fluxes in landscapes is a 'Keeling Plot' approach, which uses field-collected vapor samples coupled with a traditional isotope ratio mass spectrometer to infer the isotopic composition of evapotranspiration. However, fractionation accompanying inefficient vapor trapping can lead to large measurement uncertainty and the intensive laboring involved in cold-trap make it almost impossible for continuous measurements. Over the last 3-4 years a few groups have developed continuous approaches for measuring δ18O and δ2H that use laser absorption spectroscopy (LAS) to achieve accuracy levels similar to lab-based mass spectrometry methods. Unfortunately, most LAS systems need cryogenic cooling, constant calibration to a reference gas, and substantial power requirements, which make them unsuitable for long-term field deployment at remote field sites. In this research, we tested out a new LAS--based water vapor isotope analyzer (WVIA, Los Gatos Research, Inc, Mountain View, CA) based on Integrated Cavity Output Spectroscopy (ICOS) and coupled this instrument with a flux gradient system. The WVIA was calibrated bi- weekly using a dew point generator and water with known δ18O and δ2H signatures. The field work was performed at Morgan-Monroe State Forest Ameriflux tower site (central Indiana) between August 8 and August 27, 2008. The combination method was able to produce hourly δ18O and δ2H fluxes data with reproducibility similar to lab-based mass spectrometry methods. Such high temporal resolution data were also able to capture signatures of canopy and bare soil evaporation to individual rainfall events. The use of the ICOS water vapor analyzer within a gradient system has the potential to greatly expand the use of continuous δ18O and δ2H fluxes measurements to address a wide range of ecohydrological research topics.

VizieR Online Data Catalog: UKIDSS-DR8 LAS, GCS and DXS Surveys (Lawrence+ 2012)

NASA Astrophysics Data System (ADS)

Lawrence, A.; Warren, S. J.; Almaini, O.; Edge, A. C.; Hambly, N. C.; Jameson, R. F.; Lucas, P.; Casali, M.; Adamson, A.; Dye, S.; Emerson, J. P.; Foucaud, S.; Hewett, P.; Hirst, P.; Hodgkin, S. T.; Irwin, M. J.; Lodieu, N.; McMahon, R. G.; Simpson, C.; Smail, I.; Mortlock, D.; Folger, M.

2012-03-01

The UKIRT Infrared Deep Sky Survey (UKIDSS) is a large-scale near-IR survey which aim is to cover 7500 square degrees of the Northern sky. The survey is carried out using the Wide Field Camera (WFCAM), with a field of view of 0.21 square degrees, mounted on the 3.8m United Kingdom Infra-red Telescope (UKIRT) in Hawaii. The project comprises five surveys (LAS, GCS, DXS, GPS and UDS). The Large Area Survey (LAS) covers an area of 4000 square degrees in high Galactic latitudes (extragalactic) in the four bands Y(1.0um) J(1.2um) H(1.6um) and K(2.2um) to a depth of K=18.4. The Galactic Clusters Survey (GCS) aims to survey ten large open star clusters and star formation associations, covering a total of 1067 square degrees in the five bands Z (0.9um), Y(1.0um) J(1.2um) H(1.6um) and K(2.2um), plus a second pass in K for proper motions, to a depth of Z=20.4, Y=20.3, J=19.5, H=18.6, K=18.6. The Deep Extragalactic Survey (DXS) aims to map 35 square degrees of sky to a 5-σ point-source sensitivity of J=22.3 and K=20.8 in four carefully selected, multi-wavelength survey areas. The central regions of each field will also be mapped to H=21.8. The primary aim of the survey is to produce a photometric galaxy sample at a redshift of 1-2, within a volume comparable to that of the SDSS, selected in the same passband (rest frame optical). Details of the surveys can be found in the in the paper by Lawrence et al. (2007MNRAS.379.1599L), and at the UKIDSS Surveys site (http://www.ukidss.org/surveys/surveys.html). The data described here represent a subset of the UKIDSS data, limited to the public data and most representative columns. In the "Byte-by-byte Description" below the original names of the columns are given as bracketed names. (3 data files).

A Total Water Management Analysis of the Las Vegas Wash Watershed, Nevada

EPA Science Inventory

Climate change, land use change, and population growth are fundamental factors affecting future hydrologic conditions in streams, especially in arid regions with scarce water resources. Located in the arid southwest, Las Vegas Valley located within the Las Vegas Wash watershed is...

Cystic fibrosis–adapted Pseudomonas aeruginosa quorum sensing lasR mutants cause hyperinflammatory responses

PubMed Central

LaFayette, Shantelle L.; Houle, Daniel; Beaudoin, Trevor; Wojewodka, Gabriella; Radzioch, Danuta; Hoffman, Lucas R.; Burns, Jane L.; Dandekar, Ajai A.; Smalley, Nicole E.; Chandler, Josephine R.; Zlosnik, James E.; Speert, David P.; Bernier, Joanie; Matouk, Elias; Brochiero, Emmanuelle; Rousseau, Simon; Nguyen, Dao

2015-01-01

Cystic fibrosis lung disease is characterized by chronic airway infections with the opportunistic pathogen Pseudomonas aeruginosa and severe neutrophilic pulmonary inflammation. P. aeruginosa undergoes extensive genetic adaptation to the cystic fibrosis (CF) lung environment, and adaptive mutations in the quorum sensing regulator gene lasR commonly arise. We sought to define how mutations in lasR alter host-pathogen relationships. We demonstrate that lasR mutants induce exaggerated host inflammatory responses in respiratory epithelial cells, with increased accumulation of proinflammatory cytokines and neutrophil recruitment due to the loss of bacterial protease–dependent cytokine degradation. In subacute pulmonary infections, lasR mutant–infected mice show greater neutrophilic inflammation and immunopathology compared with wild-type infections. Finally, we observed that CF patients infected with lasR mutants have increased plasma interleukin-8 (IL-8), a marker of inflammation. These findings suggest that bacterial adaptive changes may worsen pulmonary inflammation and directly contribute to the pathogenesis and progression of chronic lung disease in CF patients. PMID:26457326

Lung Allocation Score: A Single-Center Simulation.

PubMed

Rosso, L; Palleschi, A; Tosi, D; Mendogni, P; Righi, I; Carrinola, R; Montoli, M; Damarco, F; Rossetti, V; Morlacchi, L C; Nosotti, M

2016-03-01

The lung allocation score (LAS) was introduced in the United States in May 2005 with the main goal of reducing the waiting list mortality of patients with end-stage lung diseases, but also to enhance the lung transplant benefit and improve the management of urgent candidates. Several papers have reported that LAS resulted in a reduction of the waiting list mortality but no significant survival benefit was noted. We evaluate the usefulness of LAS as a predictor for lung transplantation outcome in 123 patients listed for lung transplantation in an Italian center. Primary endpoints were waiting list mortality and posttransplant mortality at 1 year; secondary endpoints included perioperative circulatory support, cardiopulmonary bypass, primary graft dysfunction, and long-term survival after transplantation. We observed the absence of correlation between LAS and waiting list mortality. The LAS did not affect the long-term survival in our population. High LAS was predictive of primary graft dysfunction of grade 3 in the first 72 hours after transplantation. Copyright © 2016 Elsevier Inc. All rights reserved.

La implantacion del enfoque constructivista en el aula de ciencia: Estudio de caso multiple

NASA Astrophysics Data System (ADS)

Arroyo Betancourt, Luz I.

Esta investigacion estudia la implantacion del enfoque constructivista en tres aulas de ciencia del contexto puertorriqueno. Se auscultaron las practicas educativas que utilizan maestras consideradas constructivistas y la correspondencia de sus practicas educativas con los elementos esenciales de la didactica que proponen los teoricos de los planteamientos constructivistas. Se ausculto, ademas, a que vision del enfoque constructivista responden las expresiones de las maestras acerca de su practica educativa y como compara con su quehacer, a la luz de los elementos esenciales de las visiones constructivistas piagetiana, social y radical. Se utilizo el diseno de estudio descriptivo de caso multiple. El estudio se baso en entrevistas a profundidad, revision de documentos y observacion no participativa a la sala de clases. El contexto fueron tres escuelas publicas de la Region Educativa de San Juan, una elemental, una intermedia y una superior. Los resultados confirmaron que la transicion hacia el enfoque constructivista es un proceso que toma tiempo, dedicacion y la participacion en adiestramientos y readiestramientos acerca del nuevo enfoque. Las maestras coinciden en la mayoria de las practicas educativas que utilizan para implantar el enfoque constructivista de ensenanza y difieren en algunas debido, probablemente, a que han tenido que adaptarlas a los correspondientes niveles de ensenanza: elemental, intermedio y superior. Dos de las maestras planifican por conceptos generadores, mientras que una de ellas planifica siguiendo la guia que recibe del Departamento de Educacion. Difieren ademas, en el enfasis que confieren al inquirir cientifico. Con relacion a la correspondencia entre la vision manifestada por las maestras a la luz de las visiones piagetiana, social y radical, aparentemente, las preguntas del protocolo de entrevistas no lograron evocar la informacion con suficiente profundidad, por lo que la investigadora tuvo que inferir las visiones de las participantes basado en lo que estas manifestaron en su practica didactica. Dos maestras coinciden en una vision constructivista social de la construccion del conocimiento, del aprendizaje y de los metodos didacticos. La otra manifesto una vision constructivista piagetiana en el aprendizaje, los metodos didacticos y en la construccion del conocimiento. Se espera que este trabajo, ademas de promover los estudios de caso sobre el enfoque constructivista de ensenanza en el contexto puertorriqueno, sirva para que los maestros, que estan transformando su enfoque educativo de uno tradicional a uno constructivista, tengan una vision mas clara de la implantacion de este enfoque. Se espera ademas que sirva para que el Departamento de Educacion y sus programas de adiestramiento y readiestramiento en servicio, asi como las universidades y sus programas de preparacion de maestros, tomen en cuenta los resultados y recomendaciones de este estudio al revisar sus programas.

Evaluation of eggshell membrane-based bio-adsorbent for solid-phase extraction of linear alkylbenzene sulfonates coupled with high-performance liquid chromatography.

PubMed

Wang, Weidong; Chen, Bo; Huang, Yuming; Cao, Jia

2010-09-03

The potential of eggshell membrane (ESM) as a novel solid-phase extraction bio-adsorbent was investigated in the present study. The ESM with a unique structure of intricate lattice network showed a predominant ability to capture linear alkylbenzene sulfonates (LAS) as a model of organic pollutants by the hydrophobic interactions between ESM and LAS molecular at pH very close to the isoelectric point of ESM, which was similar to the most widely used trapping mechanism for SPE. Under the optimal conditions, the breakthrough capacities of the ESM packed cartridge for C10-C13 LAS homologues were found to be 30, 53, 50, and 43microgg(-1), respectively. On the basis of high-performance liquid chromatography separation and UV detection of LAS homologues, the proposed system could respond down to 0.027ngmL(-1) of LAS with a linear calibration range from 0.2 to 100ngmL(-1), showing a good LAS enrichment ability of eggshell membrane biomaterial with high sensitivity, and could be successfully used for the detection of residual LAS in environmental water samples. The reproducibility among columns was satisfactory (RSD among columns is less than 10%). A comparison study with ESM, C8 and C18 as adsorbents for LAS demonstrated that ESM-based bio-adsorbent was advantageous over C8 and C18, the widely used traditional adsorbents. 2010 Elsevier B.V. All rights reserved.

Maritime Factors Affecting Iberian Security,

DTIC Science & Technology

1980-10-01

afirme/ que para las sovie’ticas una campaiia en gran escala dirigida contra las comunicaciones marftimas del Atlantica Norte durante el perfada inicial...defender sus l ’neas de comunicacion maritima; y cuarta -- y a mi parecer la consideracion mas importante -- las otras tareas que la marina de guerra

Monitoring bird population trends in North America

USGS Publications Warehouse

Robbins, C.S.; Bystrak, D.; Geissler, P.H.; Purroy, F.J.

1983-01-01

Se ofrece un nuevo metodo para computar las oscilaciones demograficas de las aves a lo largo de los anos. Con los datos suministrados por el proyecto 'Aves nidificantes en Norteamerica' , se indican en la Tabla 1 las pautas de cambio numerico de una serie seleccionada de aves holarticas.

Bottom Sediment as a Source of Organic Contaminants in Lake Mead, Nevada, USA

EPA Science Inventory

Treated wastewater effluent from Las Vegas, Nevada and surrounding communities’ flow through Las Vegas Wash (LVW) into the Lake Mead National Recreational Area at Las Vegas Bay (LVB). Lake sediment is a likely sink for many hydrophobic synthetic organic compounds (SOCs); however,...

Is the striped mealybug, Ferrisia virgata, a vector of huanglongbing bacterium ‘Candidatus Liberibacter asiaticus’

USDA-ARS?s Scientific Manuscript database

This is the first report of ‘Ca. L. asiaticus’ (Las) present in striped mealybugs feeding on Las-infected periwinkle plants. In November 2010, specimens of a common greenhouse pest, the striped mealybug Ferrisia virgata (Cockerell) (Pseudococcidae; Hemiptera), were collected from Las-infected periw...

REMOTE SENSING OF PERCHLORATE EFFECTS ON SALT CEDAR PRELIMINARY RESULTS FROM THE LAS VEGAS WASH

EPA Science Inventory

Sodium Perchlorate and ammonium Perchlorate, major components of solid rocket fuel, have been manufactured in the Las Vegas Valley immediately up gradient from the Las Vegas Wash, since 1945 and 1956, respectively. Measurements of emerging ground water quality in the vici...

Report: EPA Needs to Improve Physical Security at Its Offices in Las Vegas, Nevada

EPA Pesticide Factsheets

Report #10-P-0059, February 3, 2010. EPA needs to improve physical security at its Las Vegas facilities. The Las Vegas Finance Center’s (LVFC’s) server room and other key areas are susceptible to unauthorized access by personnel not a part of LVFC.

Linear alkylbenzene sulfonates (LAS) in sewage sludges, soils and sediments: analytical determination and environmental safety considerations.

PubMed

De Henau, H; Mathijs, E; Hopping, W D

1986-01-01

Linear Alkylbenzenesulphonates (LAS), a major anionic surfactant used in laundry products, can be measured specifically in the environment by instrumental analysis. In addition to a desulphonation-gas chromatography approach, a method based on high performance liquid chromatography has been developed. The main features of the methods are outlined, and LAS concentrations measured in sewage sludge, sediments and sludge amended soils are reported. Knowledge of usage volumes, sewage treatment practices and environmental transport and transformation mechanisms has been used to predict concentrations of LAS. These calculated concentrations were found to agree well with those actually measured in the environment. Both measured and calculated ambient concentrations of LAS are below those which could produce potentially adverse effects in representative surface water, benthic and terrestrial organisms.

[Ethics and transparency committee of physicians in their relationship with the pharmaceutics: Industry recommendations for physician support].

PubMed

Campillo, Carlos; Domínguez, Judith; Halabe, José; Plancarte, Ricardo; Soda, Antonio; Verástegui, Emma; Arrieta, Óscar; Burgos, Rubén; Celis, Miguel Ángel; de la Llata, Manuel; Islas, Sergio; Jasso, Luis; Lifshitz, Alberto; Moreno, Mucio; Reyes, Alejandro; Sotelo, Julio

Las siguientes recomendaciones a la industria farmacéutica se fundamentan en los principios éticos del CETREMI: - El paciente es lo primero: • Que la atención sea óptima para todos los pacientes. Que las compañías farmacéuticas apoyen las decisiones del médico que garanticen el tratamiento más eficaz, seguro, accesible y adecuado. • Que las compañías farmacéuticas colaboren para que los pacientes tengan acceso fácil y oportuno a los medicamentos. • Que las compañías farmacéuticas colaboren para que la información sobre los tratamientos beneficie a los pacientes en todos los rubros, incluyendo el económico.

Implementing a laboratory automation system: experience of a large clinical laboratory.

PubMed

Lam, Choong Weng; Jacob, Edward

2012-02-01

Laboratories today face increasing pressure to automate their operations as they are challenged by a continuing increase in workload, need to reduce expenditure, and difficulties in recruitment of experienced technical staff. Was the implementation of a laboratory automation system (LAS) in the Clinical Biochemistry Laboratory at Singapore General Hospital successful? There is no simple answer, so the following topics comparing and contrasting pre- and post-LAS have been explored: turnaround time (TAT), laboratory errors, and staff satisfaction. The benefits and limitations of LAS from the laboratory experience were also reviewed. The mean TAT for both stat and routine samples decreased post-LAS (30% and 13.4%, respectively). In the 90th percentile TAT chart, a 29% reduction was seen in the processing of stat samples on the LAS. However, no significant difference in the 90th percentile TAT was observed with routine samples. It was surprising to note that laboratory errors increased post-LAS. Considerable effort was needed to overcome the initial difficulties associated with adjusting to a new system, new software, and new working procedures. Although some of the known advantages and limitations of LAS have been validated, the claimed benefits such as improvements in TAT, laboratory errors, and staff morale were not evident in the initial months.

Lithium aluminosilicate reinforced with carbon nanofiber and alumina for controlled-thermal-expansion materials

NASA Astrophysics Data System (ADS)

Borrell, Amparo; García-Moreno, Olga; Torrecillas, Ramón; García-Rocha, Victoria; Fernández, Adolfo

2012-02-01

Materials with a very low or tailored thermal expansion have many applications ranging from cookware to the aerospace industry. Among others, lithium aluminosilicates (LAS) are the most studied family with low and negative thermal expansion coefficients. However, LAS materials are electrical insulators and have poor mechanical properties. Nanocomposites using LAS as a matrix are promising in many applications where special properties are achieved by the addition of one or two more phases. The main scope of this work is to study the sinterability of carbon nanofiber (CNFs)/LAS and CNFs/alumina/LAS nanocomposites, and to adjust the ratio among components for obtaining a near-zero or tailored thermal expansion. Spark plasma sintering of nanocomposites, consisting of commercial CNFs and alumina powders and an ad hoc synthesized β-eucryptite phase, is proposed as a solution to improving mechanical and electrical properties compared with the LAS ceramics obtained under the same conditions. X-ray diffraction results on phase compositions and microstructure are discussed together with dilatometry data obtained in a wide temperature range (-150 to 450 °C). The use of a ceramic LAS phase makes it possible to design a nanocomposite with a very low or tailored thermal expansion coefficient and exceptional electrical and mechanical properties.

PubMed

Valero Chávez, Francisco Javier; Luengo Pérez, Luis Miguel; Cubero Juánez, Javier

2016-09-20

Introducción: ante las nuevas implicaciones atribuidas a la vitamina D y la asociación con enfermedades tales como el cáncer, diabetes, enfermedades cardiovasculares, autoinmunes y mortalidad, no es de extrañar que se haya defendido la medición de los niveles de vitamina D en la población general. Sin embargo, no existen datos experimentales que demuestren la viabilidad y rentabilidad de la estrategia de cribado en la población y tampoco se ha comprobado la existencia de beneficios para la salud, por lo que en la actualidad solo es aconsejable la medida de 25 (OH) vitamina D en los grupos de personas de alto riesgo como indican las guías clínicas internacionales.Objetivos: analizar las peticiones de vitamina D comprobando si se adecuan a las guías clínicas.Métodos: realizamos un estudio descriptivo transversal en el Área de Salud de Badajoz (España) estudiando las peticiones de determinación de vitamina D durante 12 meses consecutivos (n = 3.907). En dicho estudio revisamos el diagnóstico de petición y la historia clínica del paciente para discriminar entre peticiones que se adecuaban a las guías clínicas y peticiones injustificadas. Por último, realizamos el estudio económico.Resultados: en nuestros resultados encontramos que casi un tercio de peticiones no se adecuaban a las guías clínicas, en patologías tales como diabetes, dislipemias e hipertensión en las que no está recomendada la medición de los niveles de vitamina D, por lo que suponía un exceso de gasto para el sistema sanitario. Gasto que se incrementa cada año, tanto es así que se ha producido un aumento en las peticiones de más del 1.000% en los últimos 6 años.Conclusiones: concluimos la necesidad de crear protocolos de petición de vitamina D que se ajusten a las guías clínicas hasta que existan más estudios experimentales sobre las nuevas implicaciones de la vitamina D y así conseguir una correcta utilización de los recursos económicos del hospital.

SPANISH PEAKS WILDERNESS STUDY AREA, COLORADO.

USGS Publications Warehouse

Budding, Karin E.; Kluender, Steven E.

1984-01-01

A geologic and geochemical investigation and a survey of mines and prospects were conducted to evaluate the mineral-resource potential of the Spanish Peaks Wilderness Study Area, Huerfano and Las Animas Counties, in south-central Colorado. Anomalous gold, silver, copper, lead, and zinc concentrations in rocks and in stream sediments from drainage basins in the vicinity of the old mines and prospects on West Spanish Peak indicate a substantiated mineral-resource potential for base and precious metals in the area surrounding this peak; however, the mineralized veins are sparse, small in size, and generally low in grade. There is a possibility that coal may underlie the study area, but it would be at great depth and it is unlikely that it would have survived the intense igneous activity in the area. There is little likelihood for the occurrence of oil and gas because of the lack of structural traps and the igneous activity.

VizieR Online Data Catalog: Galactic bulge eclipsing & ellipsoidal binaries (Soszynski+, 2016)

NASA Astrophysics Data System (ADS)

Soszynski, I.; Pawlak, M.; Pietrukowicz, P.; Udalski, A.; Szymanski, M. K.; Wyrzykowski, L.; Ulaczyk, K.; Poleski, R.; Kozlowski, S.; Skowron, D. M.; Skowron, J.; Mroz, P.; Hamanowicz, A.

2018-04-01

Our collection of binary systems in the Galactic bulge is based on the photometric data collected by the OGLE survey between 1997 and 2015 at Las Campanas Observatory, Chile, with the 1.3-m Warsaw Telescope. The observatory is operated by the Carnegie Institution for Science. In 1997-2000, during the OGLE-II stage, about 30 million stars in the area of 11 square degrees in the central parts of the Milky Way were constantly monitored. In 2001, with the beginning of the OGLE-III survey, the sky coverage was extended to nearly 69 square degrees and the number of monitored stars increased to 200 million. Finally, from 2010 until today the OGLE-IV project regularly observes about 400 million stars in 182 square degrees of the densest regions of the Galactic bulge. Our search for eclipsing variables was based primarily on the OGLE-IV data. (4 data files).

El fenotipo de las mucinas en el esófago de Barrett

PubMed Central

Torrado, Julio; Piazuelo, María Blanca; Ruiz, Irune; Izarzugaza, María Isabel; Camargo, María Constanza; Delgado, Alberto; Abdirad, Afshin; Correa, Pelayo

2011-01-01

Antecedentes El esófago de Barrett es una reconocida lesión precursora de adenocarcinoma esofágico. Aunque generalmente asociada al reflujo gastroesofágico, los mecanismos patogénicos de la enfermedad no son bien conocidos. El objetivo del presente estudio es explorar la historia natural e identificar marcadores de progreso del proceso precanceroso. Material y métodos Se utilizaron cortes histológicos de 67 especímenes de esófago correspondientes a 14 pacientes con esófago de Barrett, a los que se siguió entre 1 – 9 años. Se clasificaron las lesiones en: esófago de Barrett sin displasia, indefinido para displasia o con displasia. Se evaluó la expresión de diferentes mucinas en las células caliciformes y en las columnares usando técnicas de histoquímica e inmunohistoquímica. Resultados En todos los casos se comprobó la presencia de metaplasia intestinal incompleta. Las células columnares dentro del epitelio metaplásico contenían mucinas neutras. A mayor severidad de la lesión se encontró significativamente menor expresión de sialomucinas en las células columnares (p de tendencia igual a 0,03). En sujetos con lesiones indefinidas para displasia se observó un mayor contenido de sulfomucinas en las células caliciformes (p=0,034) y de MUC2 en las células columnares (p=0,029) que en sujetos con esófago de Barrett sin displasia. Se observó expresión de la mucina intestinal MUC2 y de la mucina gástrica MUC5AC en todas las muestras. MUC6, una mucina de las glándulas profundas gástricas, se presentó ocasionalmente. Conclusión La evaluación de los perfiles de mucinas en el esófago de Barrett sugiere una transición gradual del fenotipo del epitelio metaplásico a medida que la lesión avanza en el tiempo. PMID:21804831

Investigaccion-accion en la sala de clases sobre las creencias de la cultura de la ciencia de un grupo de estudiantes universitarios y su relacion reciproca con el aprendizaje de las ciencias biologicas

NASA Astrophysics Data System (ADS)

Cordova-Santiago, Lizzette Astrid

La investigacion---accion que se llevo a cabo en la sala de clases tenia como punto de partida las creencias de la cultura de la ciencia de un grupo de estudiantes universitarios para luego examinar sus implicaciones en el proceso de aprendizaje de las Ciencias Biologicas. ¿Que se supone que hagan las creencias en relacion con el aprendizaje? ¿En que consiste incorporar este aspecto a la practica educativa universitaria? Utilizando el modelo de Kemmis y McTaggart (1987) la investigacion-accion se planteo como un proceso dinamico en cuatro momentos en espiral constituidos por la planificacion, la accion, la observacion y la reflexion. Cada una de las fases tuvo una intencion retrospectiva y prospectiva formando una espiral de autorreflexion del conocimiento y la accion. Se llevaron a cabo audio grabaciones en clases y analisis de documentos. Ademas, la profesora-investigadora hizo un portafolio para reflexionar sobre las creencias de la cultura de la ciencia que tienen los estudiantes y las creencias del aprendizaje que tiene la profesora y sobre como la comprension de estos elementos ayudo a mejorar su practica educativa a traves del tiempo. Los resultados obtenidos apuntan a que las creencias de la cultura de la ciencia que tiene el grupo de estudiantes son diversas. Ellos si creen que la ciencia tiene una cultura la cual describieron como: complicada y desconocida que evoluciona constantemente, que es un conjunto de metodos, que es altamente tecnologica, que resuelve problemas de salud, ayuda a interpretar la realidad del mundo que los rodea y su origen y que existen unas intersecciones entre la ciencia y el poder. Sobre las creencias del proceso de aprendizaje de la profesora-investigadora, estas senalan que el modelaje de actores, la vision de la academia que tiene ella asi como la participacion y negociacion entre todos los involucrados en el proceso educativo, son factores que inciden en el proceso de aprendizaje.

Shared genetic susceptibility to ischemic stroke and coronary artery disease – a genome-wide analysis of common variants

PubMed Central

Dichgans, Martin; Malik, Rainer; König, Inke R.; Rosand, Jonathan; Clarke, Robert; Gretarsdottir, Solveig; Thorleifsson, Gudmar; Mitchell, Braxton D.; Assimes, Themistocles L.; Levi, Christopher; O′Donnell, Christopher J.; Fornage, Myriam; Thorsteinsdottir, Unnur; Psaty, Bruce M.; Hengstenberg, Christian; Seshadri, Sudha; Erdmann, Jeanette; Bis, Joshua C.; Peters, Annette; Boncoraglio, Giorgio B.; März, Winfried; Meschia, James F.; Kathiresan, Sekar; Ikram, M. Arfan; McPherson, Ruth; Stefansson, Kari; Sudlow, Cathie; Reilly, Muredach P.; Thompson, John R.; Sharma, Pankaj; Hopewell, Jemma C.; Chambers, John C.; Watkins, Hugh; Rothwell, Peter M.; Roberts, Robert; Markus, Hugh S.; Samani, Nilesh J.; Farrall, Martin; Schunkert, Heribert

2014-01-01

Summary Background and Purpose Ischemic stroke (IS) and coronary artery disease (CAD) share several risk factors and each have a substantial heritability. We conducted a genome-wide analysis to evaluate the extent of shared genetic determination of the two diseases. Methods Genome-wide association data were obtained from the METASTROKE, CARDIoGRAM, and C4D consortia. We first analyzed common variants reaching a nominal threshold of significance (p<0.01) for CAD for their association with IS and vice versa. We then examined specific overlap across phenotypes for variants that reached a high threshold of significance. Finally, we conducted a joint meta-analysis on the combined phenotype of IS or CAD. Corresponding analyses were performed restricted to the 2,167 individuals with the ischemic large artery stroke (LAS) subtype. Results Common variants associated with CAD at p<0.01 were associated with a significant excess risk for IS and for LAS and vice versa. Among the 42 known genome-wide significant loci for CAD, three and five loci were significantly associated with IS and LAS, respectively. In the joint meta-analyses, 15 loci passed genome-wide significance (p<5×10-8) for the combined phenotype of IS or CAD and 17 loci passed genome-wide significance for LAS or CAD. Since these loci had prior evidence for genome-wide significance for CAD we specifically analyzed the respective signals for IS and LAS and found evidence for association at chr12q24/SH2B3 (pIS=1.62×10-07) and ABO (pIS =2.6×10-4) as well as at HDAC9 (pLAS=2.32×10-12), 9p21 (pLAS =3.70×10-6), RAI1-PEMT-RASD1 (pLAS =2.69×10-5), EDNRA (pLAS =7.29×10-4), and CYP17A1-CNNM2-NT5C2 (pLAS =4.9×10-4). Conclusions Our results demonstrate substantial overlap in the genetic risk of ischemic stroke and particularly the large artery stroke subtype with coronary artery disease. PMID:24262325

Analysis of the transmission of Trypanosoma cruzi infection through hosts and vectors.

PubMed

Fabrizio, María C; Schweigmann, Nicolás J; Bartoloni, Norberto J

2016-08-01

Calculating epidemiological measures of infection by Trypanosoma cruzi, the causative agent of Chagas disease, is complex, because it involves several species, different stages of infection in humans and multiple transmission routes. Using the next-generation matrix method, we analysed a model which considers the three stages of human infection, triatomines and dogs (the main domestic reservoirs of T. cruzi when triatomines are present) and the main transmission routes. We derived R 0 and type-reproduction numbers T. We deduced formulas for the number of new infections generated through each transmission route by each infected individual. We applied our findings in Argentine Gran Chaco. The expressions achieved allowed quantifying the high infectivity of dogs and emphasizing the epidemiological importance of the long and asymptomatic chronic indeterminate stage in humans in the spread of the infection. According to the model, it is expected that one infected human infects 21 triatomines, that 100 infected triatomines are necessary to infect one human and 34 to infect a dog, and that each dog infects on average one triatomine per day. Our results may allow quantifying the effect of control measures on infected humans, triatomines and dogs (or other highly infected vertebrate) or on a specific route of transmission, in other scenarios.

Computer analysis of sound recordings from two Anasazi sites in northwestern New Mexico

NASA Astrophysics Data System (ADS)

Loose, Richard

2002-11-01

Sound recordings were made at a natural outdoor amphitheater in Chaco Canyon and in a reconstructed great kiva at Aztec Ruins. Recordings included computer-generated tones and swept sine waves, classical concert flute, Native American flute, conch shell trumpet, and prerecorded music. Recording equipment included analog tape deck, digital minidisk recorder, and direct digital recording to a laptop computer disk. Microphones and geophones were used as transducers. The natural amphitheater lies between the ruins of Pueblo Bonito and Chetro Ketl. It is a semicircular arc in a sandstone cliff measuring 500 ft. wide and 75 ft. high. The radius of the arc was verified with aerial photography, and an acoustic ray trace was generated using cad software. The arc is in an overhanging cliff face and brings distant sounds to a line focus. Along this line, there are unusual acoustic effects at conjugate foci. Time history analysis of recordings from both sites showed that a 60-dB reverb decay lasted from 1.8 to 2.0 s, nearly ideal for public performances of music. Echoes from the amphitheater were perceived to be upshifted in pitch, but this was not seen in FFT analysis. Geophones placed on the floor of the great kiva showed a resonance at 95 Hz.

Low prevalence of methicillin-resistant Staphylococcus aureus nasal carriage in urban and rural community settings in Bolivia and Peru.

PubMed

Bartoloni, Alessandro; Pallecchi, Lucia; Fernandez, Connie; Mantella, Antonia; Riccobono, Eleonora; Magnelli, Donata; Mannini, Dario; Strohmeyer, Marianne; Bartalesi, Filippo; Segundo, Higinio; Monasterio, Joaquin; Rodriguez, Hugo; Cabezas, César; Gotuzzo, Eduardo; Rossolini, Gian Maria

2013-05-01

To investigate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage in rural and urban community settings of Bolivia and Peru. MRSA nasal carriage was investigated in 585 individuals living in rural and urban areas of Bolivia and Peru (one urban area, one small rural village, and two native communities, one of which was highly isolated). MRSA isolates were subjected to molecular analysis for the detection of virulence genes, characterization of the staphylococcal cassette chromosome mec (SCCmec), and genotyping (multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE)). An overall very low prevalence of MRSA nasal carriage was observed (0.5%), with MRSA carriers being detected only in a small rural village of the Bolivian Chaco. The three MRSA isolates showed the characteristics of community-associated MRSA (being susceptible to all non-beta-lactam antibiotics and harboring the SCCmec type IV), were clonally related, and belonged to ST1649. This study provides an insight into the epidemiology of MRSA in community settings of Bolivia and Peru. Reliable, time-saving, and low-cost methods should be implemented to encourage continued surveillance of MRSA dissemination in resource-limited countries. Copyright © 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Illegal hunting cases detected with molecular forensics in Brazil

PubMed Central

2012-01-01

Background Illegal hunting is one of the major threats to vertebrate populations in tropical regions. This unsustainable practice has serious consequences not only for the target populations, but also for the dynamics and structure of tropical ecosystems. Generally, in cases of suspected illegal hunting, the only evidence available is pieces of meat, skin or bone. In these cases, species identification can only be reliably determined using molecular technologies. Here, we reported an investigative study of three cases of suspected wildlife poaching in which molecular biology techniques were employed to identify the hunted species from remains of meat. Findings By applying cytochrome b (cyt-b) and cytochrome oxidase subunit I (COI) molecular markers, the suspected illegal poaching was confirmed by the identification of three wild species, capybara (Hydrochoerus hydrochaeris), Chaco Chachalaca (Ortalis canicollis) and Pampas deer (Ozotoceros bezoarticus). In Brazil, hunting is a criminal offense, and based on this evidence, the defendants were found guilty and punished with fines; they may still be sentenced to prison for a period of 6 to 12 months. Conclusions The genetic analysis used in this investigative study was suitable to diagnose the species killed and solve these criminal investigations. Molecular forensic techniques can therefore provide an important tool that enables local law enforcement agencies to apprehend illegal poachers. PMID:22863070

Tropical ancient DNA reveals relationships of the extinct Bahamian giant tortoise Chelonoidis alburyorum

PubMed Central

Kehlmaier, Christian; Barlow, Axel; Hastings, Alexander K.; Vamberger, Melita; Paijmans, Johanna L. A.; Steadman, David W.; Albury, Nancy A.; Franz, Richard; Hofreiter, Michael

2017-01-01

Ancient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands. We have reconstructed the near-complete mitochondrial genome of an extinct giant tortoise from the Bahamas (Chelonoidis alburyorum) using an approximately 1 000-year-old humerus from a water-filled sinkhole (blue hole) on Great Abaco Island. Phylogenetic and molecular clock analyses place this extinct species as closely related to Galápagos (C. niger complex) and Chaco tortoises (C. chilensis), and provide evidence for repeated overseas dispersal in this tortoise group. The ancestors of extant Chelonoidis species arrived in South America from Africa only after the opening of the Atlantic Ocean and dispersed from there to the Caribbean and the Galápagos Islands. Our results also suggest that the anoxic, thermally buffered environment of blue holes may enhance DNA preservation, and thus are opening a window for better understanding evolution and population history of extinct tropical species, which would likely still exist without human impact. PMID:28077774

The floristic heterogeneity of the Pantanal and the occurrence of species with different adaptive strategies to water stress.

PubMed

Scremin-Dias, E; Lorenz-Lemke, A P; Oliveira, A K M

2011-04-01

The Pantanal is characterised by a diversity of environments with areas ranging from periodic or permanent heavy flooding to areas with low flood levels, and even environments that never flood. Plant species which inhabit the floodplain are distributed in specific niches, with influence of various phytogeographic domains, including the Seasonal Semi-deciduous Forest, Amazon Rainforest, Cerrado and Chaco, as well rocky remnants, with a wide ecological span in their components. In intensely flooded areas, aquatic macrophytes are widely distributed, with their dynamics closely linked to time, depth and extent of flooding. Although the term "Pantanal" suggests a huge swamp-type wetland, water level variation during a seasonal cycle does not directly reach the root system of many plants. The landscape diversity of the Pantanal wetland is molded by the flood pulse, which interferes with the dynamics of plant communities. Therefore, the retraction and expansion of populations or communities is reflected in important ecological characteristics, considering the variety of morphological, anatomical and ecophysiological features of the species, whose phenotype is the result of a particular genotype. The present study discusses peculiar issues in the adaptation of species distributed in the Pantanal biome and underscores the importance of multidisciplinary approaches to obtain conclusive data on adaptive studies.

Globalization’s unexpected impact on soybean production in South America: linkages between preferences for non-genetically modified crops, eco-certifications, and land use

NASA Astrophysics Data System (ADS)

Garrett, Rachael D.; Rueda, Ximena; Lambin, Eric F.

2013-12-01

The land use impacts of globalization and of increasing global food and fuel demand depend on the trade relationships that emerge between consuming and producing countries. In the case of soybean production, increasing trade between South American farmers and consumers in Asia and Europe has facilitated soybean expansion in the Amazon, Chaco, and Cerrado biomes. While these telecouplings have been well documented, there is little understanding of how quality preferences influence trade patterns and supply chains, incentivizing or discouraging particular land use practices. In this study we provide empirical evidence that Brazil’s continued production of non-genetically modified (GM) soybeans has increased its competitive advantage in European countries with preferences against GM foods. Brazil’s strong trade relationship with European consumers has facilitated an upgrading of the soybean supply chain. Upgraded soybean supply chains create new conservation opportunities by allowing farmers to differentiate their products based on environmental quality in order to access premiums in niche markets in Europe. These interactions between GM preferences, trade flows, and supply chain structure help to explain why Brazilian soybean farmers have adopted environmental certification programs on a larger scale than Argentinian, Bolivian, Paraguayan, and Uruguayan soybean producers.

Creating Geoscience Leaders

NASA Astrophysics Data System (ADS)

Buskop, J.; Buskop, W.

2013-12-01

The United Nations Educational, Scientific, and Cultural Organization recognizes 21 World Heritage in the United States, ten of which have astounding geological features: Wrangell St. Elias National Park, Olympic National Park, Mesa Verde National Park, Chaco Canyon, Glacier National Park, Carlsbad National Park, Mammoth Cave, Great Smokey Mountains National Park, Hawaii Volcanoes National Park, and Everglades National Park. Created by a student frustrated with fellow students addicted to smart phones with an extreme lack of interest in the geosciences, one student visited each World Heritage site in the United States and created one e-book chapter per park. Each chapter was created with original photographs, and a geological discovery hunt to encourage teen involvement in preserving remarkable geological sites. Each chapter describes at least one way young adults can get involved with the geosciences, such a cave geology, glaciology, hydrology, and volcanology. The e-book describes one park per chapter, each chapter providing a geological discovery hunt, information on how to get involved with conservation of the parks, geological maps of the parks, parallels between archaeological and geological sites, and how to talk to a ranger. The young author is approaching UNESCO to publish the work as a free e-book to encourage involvement in UNESCO sites and to prove that the geosciences are fun.

Tropical ancient DNA reveals relationships of the extinct Bahamian giant tortoise Chelonoidis alburyorum.

PubMed

Kehlmaier, Christian; Barlow, Axel; Hastings, Alexander K; Vamberger, Melita; Paijmans, Johanna L A; Steadman, David W; Albury, Nancy A; Franz, Richard; Hofreiter, Michael; Fritz, Uwe

2017-01-11

Ancient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands. We have reconstructed the near-complete mitochondrial genome of an extinct giant tortoise from the Bahamas (Chelonoidis alburyorum) using an approximately 1 000-year-old humerus from a water-filled sinkhole (blue hole) on Great Abaco Island. Phylogenetic and molecular clock analyses place this extinct species as closely related to Galápagos (C. niger complex) and Chaco tortoises (C. chilensis), and provide evidence for repeated overseas dispersal in this tortoise group. The ancestors of extant Chelonoidis species arrived in South America from Africa only after the opening of the Atlantic Ocean and dispersed from there to the Caribbean and the Galápagos Islands. Our results also suggest that the anoxic, thermally buffered environment of blue holes may enhance DNA preservation, and thus are opening a window for better understanding evolution and population history of extinct tropical species, which would likely still exist without human impact. © 2017 The Author(s).

Etnografía acelerada para transformar normas sociales sobre género y sexualidad en hombres puertorriqueños heterosexuales1,2

PubMed Central

Ortiz-Torres, Blanca; Rivera-Ortiz, Rafael J.; Mendoza, Sigrid

2014-01-01

Resumen La construcción de roles de género dominantes contribuyen al riesgo de contraer VIH, y por tal razón se ha urgido a que se integren las normas sociales relativas al género en las intervenciones preventivas del VIH. Este estudio pretende adaptar y desarrollar una intervención que facilite la transformación de normas sociales del género y de prácticas sexuales en hombres puertorriqueños. La intervención propone transformar normas sociales relacionadas al género y sexualidad en barras comunitarias utilizando el modelo de líderes de opinión. Luego de ser elegidos/as, los/as líderes de opinión diseminan mensajes integrando la importancia de relaciones equitativas entre parejas para la prevención del VIH. La primera fase de esta intervención es discutida en este artículo, la cual incluye un proceso de etnografía acelerada para identificar los escenarios comunitarios en los que podemos desarrollar esta intervención y permitirnos entender la cultura de las barras comunitarias. A partir de las observaciones etnográficas, pudimos: desarrollar un protocolo de seguridad para realizar las observaciones, desarrollar un perfil de la cultura de las barras, elegir las barras a participar en las dos condiciones del estudio y adaptar los instrumentos de la intervención para que respondieran a la particularidad de los/as participantes. PMID:25530828

Subsurface architecture of Las Bombas volcano circular structure (Southern Mendoza, Argentina) from geophysical studies

NASA Astrophysics Data System (ADS)

Prezzi, Claudia; Risso, Corina; Orgeira, María Julia; Nullo, Francisco; Sigismondi, Mario E.; Margonari, Liliana

2017-08-01

The Plio-Pleistocene Llancanelo volcanic field is located in the south-eastern region of the province of Mendoza, Argentina. This wide back-arc lava plateau, with hundreds of monogenetic pyroclastic cones, covers a large area behind the active Andean volcanic arc. Here we focus on the northern Llancanelo volcanic field, particularly in Las Bombas volcano. Las Bombas volcano is an eroded, but still recognizable, scoria cone located in a circular depression surrounded by a basaltic lava flow, suggesting that Las Bombas volcano was there when the lava flow field formed and, therefore, the lava flow engulfed it completely. While this explanation seems reasonable, the common presence of similar landforms in this part of the field justifies the need to establish correctly the stratigraphic relationship between lava flow fields and these circular depressions. The main purpose of this research is to investigate Las Bombas volcano 3D subsurface architecture by means of geophysical methods. We carried out a paleomagnetic study and detailed topographic, magnetic and gravimetric land surveys. Magnetic anomalies of normal and reverse polarity and paleomagnetic results point to the occurrence of two different volcanic episodes. A circular low Bouguer anomaly was detected beneath Las Bombas scoria cone indicating the existence of a mass deficit. A 3D forward gravity model was constructed, which suggests that the mass deficit would be related to the presence of fracture zones below Las Bombas volcano cone, due to sudden degassing of younger magma beneath it, or to a single phreatomagmatic explosion. Our results provide new and detailed information about Las Bombas volcano subsurface architecture.

Local anesthetic-induced inhibition of human neutrophil priming: the influence of structure, lipophilicity, and charge.

PubMed

Picardi, Susanne; Cartellieri, Sibylle; Groves, Danja; Hahnenkamp, Klaus; Hahnenekamp, Klaus; Gerner, Peter; Durieux, Marcel E; Stevens, Markus F; Lirk, Philipp; Hollmann, Markus W

2013-01-01

Local anesthetics (LAs) are widely known for inhibition of voltage-gated sodium channels underlying their antiarrhythmic and antinociceptive effects. However, LAs have significant immunomodulatory properties and were shown to affect human neutrophil functions independent of sodium-channel blockade. Previous studies suggest a highly selective interaction between LAs and the α-subunit of G protein-coupled receptors of the Gq/G11 family as underlying mechanism. Providing a detailed structure function analysis, this study aimed to determine the active parts within the LA molecule responsible for the effects on human neutrophil priming. Human neutrophils were incubated with structurally different LAs for 60 minutes, followed by priming and activation using either platelet-activating factor or lysophosphatidic acid and N-formyl-methionyl-L-leucyl-L-phenylalanine. Superoxide anion generation was determined, using the cytochrome c reduction assay. Differences in priming inhibition of human neutrophils between LAs were smaller than expected, although significant. Ester-linked LAs blocked priming responses more effectively than did amide LAs. Furthermore, the inhibitory potency of LAs on priming decreased with an increase of their respective octanol-buffer coefficient, and inhibition did not correlate with sodium-channel-blocking potency. Charge was not crucially required for priming inhibition, yet it played a role in effect size. Local anesthetics significantly attenuated Gαq-protein-mediated neutrophil priming. The most potent inhibition was achieved by ester compounds, inversely correlated with their octanol-buffer coefficient, and enhanced by permanent charges within the LA molecule. No correlation to their potency of blocking sodium channels was found.

Environmental monitoring study of linear alkylbenzene sulfonates and insoluble soap in Spanish sewage sludge samples.

PubMed

Cantarero, Samuel; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Reis, Marco S; Saraiva, Pedro M; Vílchez, José L

2011-01-01

In this work we present a monitoring study of linear alkylbenzene sulfonates (LAS) and insoluble soap performed on Spanish sewage sludge samples. This work focuses on finding statistical relations between LAS concentrations and insoluble soap in sewage sludge samples and variables related to wastewater treatment plants such as water hardness, population and treatment type. It is worth to mention that 38 samples, collected from different Spanish regions, were studied. The statistical tool we used was Principal Component Analysis (PC), in order to reduce the number of response variables. The analysis of variance (ANOVA) test and a non-parametric test such as the Kruskal-Wallis test were also studied through the estimation of the p-value (probability of obtaining a test statistic at least as extreme as the one that was actually observed, assuming that the null hypothesis is true) in order to study possible relations between the concentration of both analytes and the rest of variables. We also compared LAS and insoluble soap behaviors. In addition, the results obtained for LAS (mean value) were compared with the limit value proposed by the future Directive entitled "Working Document on Sludge". According to the results, the mean obtained for soap and LAS was 26.49 g kg(-1) and 6.15 g kg(-1) respectively. It is worth noting that LAS mean was significantly higher than the limit value (2.6 g kg(-1)). In addition, LAS and soap concentrations depend largely on water hardness. However, only LAS concentration depends on treatment type.

Las Migraciones en el Proceso de Integracion de las Americas: Seminario Internacional (Migration in the Integration Process in the Americas: International Seminar). Conference report.

PubMed

Berglund, S

1993-01-01

This conference report of the Centro de Estudios Migratorios Latinoamericanos and the Center for Migration Studies pertains to meetings held in August 1992. Summary information on migration movements in Latin America is presented by region and subject. The topic of integration in the Americas was presented by Mr. Lelio Marmora. Other topics and presenters include the new Colombian Migration Policy (Mr. Carlos Adolfo Arenas), the integration policies in Central America (Mr. Pilar Norza of Costa Rica, Raimundo Alvarado of El Salvador, and Luis Armando Gusman of Nicaragua), the Andean Pact agreements (representatives of each country), US immigration policy (Charles B. Keely), the Mexican integration with Latin America and immigration to the US (Jorge Bustamante), migration to Bolivia and Argentina and Chile, and transnationalism in the Caribbean (Professor Andre Corten). Migration policy needs to be tailored specifically to the situation in Latin America, and greater attention needs to be devoted to labor migrants' rights and working conditions. There are still fundamental differences among countries in policies regarding the free circulation of persons across borders. There is a division among those who support migration and those who are realists. National sovereignty issues are solvable because of a common national past and a relatively homogenous population. Another opinion is that Latin America is more diverse than commonly recognized. Capital is protected more in international agreements than is migrant labor. Regional integration for the US does mean immigration from Mexico. The US sees Mexican migration as a policy problem, and Mexico sees migration as a labor opportunity.

Fragmentary evidence of great-earthquake subsidence during holocene emergence, Valdivia estuary, South Central Chile

USGS Publications Warehouse

Nelson, A.R.; Kashima, K.; Bradley, L.A.

2009-01-01

A reconnaissance of Holocene stratigraphy beneath fringing marshes of the Valdivia estuary, where an M 9.5 earthquake caused 1-2 m of regional coseismic subsidence in 1960, shows only fragmentary evidence of prehistoric coseismic subsidence. In most of the 150 hand-driven cores that were examined, a distinct unconformity separates 0.5-1.5 m of late Holocene tidal and floodplain mud, peat, and sand from underlying middle Holocene subtidal mud and sand. At the Las Coloradas site, where stratigraphy is best preserved, two A horizons of marsh and meadow soils abruptly overlain by sand and mud probably record coseismic subsidence shortly followed by tsunamis. The amount of subsidence during the earthquakes proved difficult to reconstruct with a diatom transfer function because of differences between modern and fossil diatom assemblages. Maximum 14C ages on macrofossils from the two A horizons at the Las Coloradas site of 1.7-1.3 ka and 2.7-1.7 ka allow correlation of the younger horizon with either of two of six 14C-dated A horizons buried by tsunami sand or post-tsunami tidal sand 200 km to the south at Maull??n, and with a lake-wide mass wasting event in Lago Puyehue, 100 km to the southeast. Tidal records of prehistoric coseismic subsidence at Valdivia are scarce because of a sea-level fall of 3-8 m over the past 6000 years, erosion of marsh and meadow soils during subsidence-induced flooding of the estuary, and largely complete land-level recovery during cycles of coseismic subsidence and postseismic uplift.

Analisis espacial de las areas protegidas terrestres de Puerto Rico

Treesearch

M. Quinones; W.A. Gould; J. Castro-Prieto; S. Martinuzzi

2013-01-01

En este mapa de investigacion describimos las areas protegidas terrestres de Puerto Rico basado en elementos naturales y antropogenicos del paisaje. Utilizamos datos geoespaciales para calcular la extension y representatividad de elementos del paisaje dentro de las areas protegidas de Puerto Rico, i.e., cobertura del terreno (Gould et al. 2007), asentamientos urbanos...

Establishment and characterization of a novel lymphangiosarcoma cell line (MO-LAS) compared with the hemangiosarcoma cell line (ISO-HAS).

PubMed

Masuzawa, Mikio; Masuzawa, Mamiko; Hamada, Yuhko; Arakawa, Nobuko; Mori, Mari; Ishii, Masako; Nishiyama, Shigeo

2012-08-01

The concept of "lymphangiosarcoma" remains obscure. Therefore, we reported a patient with lymphangiosarcoma, resistant to immunotherapy. The patient presented with impressive and discriminative features: clinically an ill-defined edematous lesion with lymphorrhea and pathologically atypical vascular channel formation without extravasation of blood, clearly distinguished from common angiosarcoma with hemorrhage. From this case, a lymphangiosarcoma cell line, MO-LAS, was established and its characteristics were compared with the hemangiosarcoma cell line, ISO-HAS. Flow cytometric analysis revealed that MO-LAS was negative for factor VIII-related antigen, but positive for CD31, D2-40, NZ-1, and vascular endothelial growth factor receptor-3 (VEGFR-3), similar to ISO-HAS. However, MO-LAS expressed a much higher level of homeobox gene PROX1, indicating a lymphatic phenotype, compared with ISO-HAS. Furthermore, MO-LAS showed a much lesser expression of oncogenes and much lower sensitivity against lymphokine-activated killer (LAK) cells. Lymphangiosarcoma may be difficult to recognize by the immune system. Conclusively, the establishment of MO-LAS, a novel angiosarcoma cell line bearing lymphatic characters, strongly suggests the entity of lymphangiosarcoma.

Las Vegas

NASA Image and Video Library

2001-10-22

This image of Las Vegas, NV was acquired on August, 2000 and covers an area 42 km (25 miles) wide and 30 km (18 miles) long. The image displays three bands of the reflected visible and infrared wavelength region, with a spatial resolution of 15 m. McCarran International Airport to the south and Nellis Air Force Base to the NE are the two major airports visible. Golf courses appear as bright red areas of worms. The first settlement in Las Vegas (which is Spanish for The Meadows) was recorded back in the early 1850s when the Mormon church, headed by Brigham Young, sent a mission of 30 men to construct a fort and teach agriculture to the Indians. Las Vegas became a city in 1905 when the railroad announced this city was to be a major division point. Prior to legalized gambling in 1931, Las Vegas was developing as an agricultural area. Las Vegas' fame as a resort area became prominent after World War II. The image is located at 36.1 degrees north latitude and 115.1 degrees west longitude. http://photojournal.jpl.nasa.gov/catalog/PIA11096

The neutral oil in commercial linear alkylbenzenesulfonate and its effect on organic solute solubility in water

USGS Publications Warehouse

Chiou, C.T.; Kile, D.E.; Rutherford, D.W.

1991-01-01

Apparent water solubilities of 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), 2,4,5,2???,5???-penta-chlorobiphenyl (PCB), and 1,2,3-trichlorobenzene (TCB) were determined at room temperature in aqueous solutions of commercial linear alkylbenzenesulfonate (LAS), oil-free (solvent-extracted) LAS, and single-molecular 4-dodecyl-benzenesulfonate. The extent of solute solubility enhancement by commercial LAS is markedly greater than that by other ionic surfactants below the measured critical micelle concentration (CMC); above the CMC, the enhancement data with LAS are comparable with other surfactants as micelles. The small amount of neutral oils in commercial LAS (1.7%), comprising linear alkylbenzenes (LABs) and bis(alkylphenyl) sulfones, contributes significantly to the enhanced solubility of DDT and PCB below the CMC; the effect is ascribed to formation of oil-surfactant emulsions. The oil-surfactant emulsion formed corresponds to ???9-10% of the commercial LAS below the CMC. The data suggest that discharge of wastewater containing a significant level of oils and surface-active agents could lead to potential mobilization of organic pollutants and LABs in aquatic environments.

Microbial biodegradation of organic wastes containing surfactants in a continuous-flow reactor.

PubMed

Konopka, A; Zakharova, T; Oliver, L; Turco, R F

1997-04-01

In a continuous flow bioreactor seeded with microbes from municipal activated sludge, complete organic carbon oxidation of simulated graywater (wastewater produced in human residences, excluding toilet wastes) was achieved at dilution rates up to 0.36 h-1 in the presence of 64.1 microM linear alkylbenzenesulfonate (LAS) L-1. At LAS concentrations of 187 microM, the system functioned only at dilution rates up to 0.23 h-1, and the biomass yield was two-fold lower. There were physiological changes in the microbial communities under different operating conditions, as measured by specific contents of ATP and extracellular hydrolases as well as the respiratory potential of the biomass. LAS inhibited the activity of LAS-degrading microbes at >150 microM LAS, and the activity of other microbes at >75 microM LAS. Chemical analysis of graywater indicated that samples consisted primarily of biological polymers (proteins and polysaccharides) and lower concentrations of surfactants. Biological remediation of graywater is possible, although treatment efficiency is influenced by the operating conditions and wastestream composition.

Psychometric properties of a suicide screen for adjudicated youth in residential care.

PubMed

Langhinrichsen-Rohling, Jennifer; Hudson, Kenneth; Lamis, Dorian A; Carr, Nicole

2012-04-01

There is a need to efficiently and effectively screen adjudicated youth residing within the juvenile justice system for suicide proneness. Accordingly, in the current study, the psychometric properties of the Life Attitude Schedule: Short Form (LAS:S), a 24-item risk assessment for suicide proneness, were assessed using data from adjudicated youth residing in an alternative sentencing facility (n = 130). As predicted, statistically significant correlations were obtained between total LAS:S suicide proneness scores and reports of recent suicide ideation and hopelessness. Contrary to expectation, the previously reported 2-factor model for the LAS:S, with Factor 1 representing physical unhealthiness and Factor 2 representing psychological death, poorly fit the data. In adjudicated youth, we found that a single factor model derived from the 4 LAS:S subscales produced a better fit to the data than the 2-factor model. The death-related, self-related, injury-related, and negative health-related behaviors contained on the LAS:S shared common variance in these youth. A clinical implication is that practitioners can effectively use the total LAS:S score when screening adjudicated youth for suicide proneness.

Astronomía Mocoví

NASA Astrophysics Data System (ADS)

López, A.; Giménez Benitez, S.; Fernández, L.

El presente trabajo, es una revisión crítica de la astronomía en la cultura Mocoví, aportando a lo realizado previamente por Lehmann Nistche (Lehmann Nistche, 1924 y 1927) el resultado de nuestro trabajo de campo. Un mayor conocimiento de las cosmovisiones de las etnias de esta área es fundamental para una mejor comprensión de la dispersión de las ideas cosmológicas entre los pueblos aborígenes americanos, dada la importancia del corredor chaqueño como conexión entre las altas culturas andinas, la mesopotamia y la región pampeana (Susnik, 1972). Para ello se realiza una comparación con otras cosmovisiones del área americana. Nuestro aporte se enmarca dentro de las actuales líneas de trabajo mundialmente en desarrollo en Astronomía en la Cultura.

PREVENCIÓN DEL VIH/SIDA EN LOS CIRCUITOS DE LEVANTE HSH: UNA ASIGNATURA PENDIENTE.

PubMed

Barreda, Victoria; Carballo-Dieguez, Alex; Marone, Rubén; Balán, Iván; Pando, María Ángeles; Avila, María Mercedes

2010-12-01

A partir de un relevamiento de tipo etnográfico, se describen lugares de encuentro de HSH en la Ciudad de Buenos Aires y sus prácticas sexuales. El reconocimiento de tales espacios, así como las características que asumen en ellos los encuentros sexuales entre los HSH, plantean obstáculos específicos en la adopción de comportamientos preventivos y, asimismo, generan nuevos desafíos para las actividades de prevención. Se plantean las dificultades y debates conceptuales que la misma categoría presenta, y sus consecuencias en el abordaje preventivo y teórico-metodológico para las ciencias sociales. Además, se proponen nuevos interrogantes acerca de los alcances y las limitaciones del modelo preventivo del VIH/Sida para HSH.

[Not Available].

PubMed

Joaquín Ortiz, Clara

2016-06-03

En la actualidad existe una alta variabilidad en la práctica clínica en nutrición que podría afectar al estado nutricional de los pacientes oncológicos. La implementación de guías de práctica clínica de adecuada calidad puede ayudarnos a disminuir esta variabilidad y minimizar los efectos deletéreos de la malnutrición en los pacientes oncológicos. Las guías suelen estar basadas en la evidencia, formulando las recomendaciones a partir de la mejor información disponible. No obstante, es importante tener en cuenta la calidad metodológica en la elaboración de las guías y valorar si existen conflictos de interés. Los principales problemas de las guías actuales suelen ser que existe limitada evidencia de alta calidad, y que las recomendaciones basadas exclusivamente en la evidencia pueden no ser útiles en la práctica clínica diaria, ya que no tienen en cuenta la aplicabilidad que es fundamental para su implementación. Por otro lado, las guías clínicas hasta la actualidad han sido inconsistentes en la forma de evaluar la calidad de la evidencia y el grado de recomendación. Como resultado, los usuarios se enfrentan al desafío de comprender los mensajes que los diferentes sistemas de grados de evidencia tratan de comunicar. En esta revisión se realiza un resumen de las recomendaciones de las principales guías clínicas sobre valoración y/o soporte nutricional en pacientes oncohematológicos desarrolladas en los últimos 10 años, incluyendo algunas guías de calidad de sociedades científicas que no son accesibles a través de las bases de datos comúnmente usadas como PubMed.

The effect of ‘Candidatus Liberibacter asiaticus’ infection on the proteomic profiles and nutritional status of pre-symptomatic and symptomatic grapefruit (Citrus paradisi) plants

PubMed Central

2013-01-01

Background Huanglongbing (HLB) is a highly destructive citrus disease which threatens citrus production worldwide and ‘Candidatus Liberibacter asiaticus’ (Las), a non-culturable phloem-limited bacterium, is an associated causal agent of the disease. To better understand the physiological and molecular processes involved in host responses to Las, 2-DE and mass spectrometry analyses, as well as ICP spectroscopy analysis were employed to elucidate the global protein expression profiles and nutrient concentrations in leaves of Las-infected grapefruit plants at pre-symptomatic or symptomatic stages for HLB. Results This study identified 123 protein spots out of 191 spots that showed significant changes in the leaves of grapefruit plants in response to Las infection and all identified spots matched to 69 unique proteins/peptides. A down-regulation of 56 proteins including those associated with photosynthesis, protein synthesis, and metabolism was correlated with significant reductions in the concentrations of Ca, Mg, Fe, Zn, Mn, and Cu in leaves of grapefruit plants in response to Las infection, particularly in symptomatic plants. Oxygen-evolving enhancer (OEE) proteins, a PSI 9 kDa protein, and a Btf3-like protein were among a small group of proteins that were down-regulated in both pre-symptomatic and symptomatic plants in response to Las infection. Furthermore, a Las-mediated up-regulation of 13 grapefruit proteins was detected, which included Cu/Zn superoxide dismutase, chitinases, lectin-related proteins, miraculin-like proteins, peroxiredoxins and a CAP 160 protein. Interestingly, a Las-mediated up-regulation of granule-bound starch synthase was correlated with an increase in the K concentrations of pre-symptomatic and symptomatic plants. Conclusions This study constitutes the first attempt to characterize the interrelationships between protein expression and nutritional status of Las-infected pre-symptomatic or symptomatic grapefruit plants and sheds light on the physiological and molecular mechanisms associated with HLB disease development. PMID:23578104

The effect of 'Candidatus Liberibacter asiaticus' infection on the proteomic profiles and nutritional status of pre-symptomatic and symptomatic grapefruit (Citrus paradisi) plants.

PubMed

Nwugo, Chika C; Lin, Hong; Duan, Yongping; Civerolo, Edwin L

2013-04-11

Huanglongbing (HLB) is a highly destructive citrus disease which threatens citrus production worldwide and 'Candidatus Liberibacter asiaticus' (Las), a non-culturable phloem-limited bacterium, is an associated causal agent of the disease. To better understand the physiological and molecular processes involved in host responses to Las, 2-DE and mass spectrometry analyses, as well as ICP spectroscopy analysis were employed to elucidate the global protein expression profiles and nutrient concentrations in leaves of Las-infected grapefruit plants at pre-symptomatic or symptomatic stages for HLB. This study identified 123 protein spots out of 191 spots that showed significant changes in the leaves of grapefruit plants in response to Las infection and all identified spots matched to 69 unique proteins/peptides. A down-regulation of 56 proteins including those associated with photosynthesis, protein synthesis, and metabolism was correlated with significant reductions in the concentrations of Ca, Mg, Fe, Zn, Mn, and Cu in leaves of grapefruit plants in response to Las infection, particularly in symptomatic plants. Oxygen-evolving enhancer (OEE) proteins, a PSI 9 kDa protein, and a Btf3-like protein were among a small group of proteins that were down-regulated in both pre-symptomatic and symptomatic plants in response to Las infection. Furthermore, a Las-mediated up-regulation of 13 grapefruit proteins was detected, which included Cu/Zn superoxide dismutase, chitinases, lectin-related proteins, miraculin-like proteins, peroxiredoxins and a CAP 160 protein. Interestingly, a Las-mediated up-regulation of granule-bound starch synthase was correlated with an increase in the K concentrations of pre-symptomatic and symptomatic plants. This study constitutes the first attempt to characterize the interrelationships between protein expression and nutritional status of Las-infected pre-symptomatic or symptomatic grapefruit plants and sheds light on the physiological and molecular mechanisms associated with HLB disease development.

Pseudomonas aeruginosa LasB protease impairs innate immunity in mice and humans by targeting a lung epithelial cystic fibrosis transmembrane regulator–IL-6–antimicrobial–repair pathway

PubMed Central

Saint-Criq, Vinciane; Villeret, Bérengère; Bastaert, Fabien; Kheir, Saadé; Hatton, Aurélie; Cazes, Aurélie; Xing, Zhou; Sermet-Gaudelus, Isabelle; Garcia-Verdugo, Ignacio; Edelman, Aleksander

2018-01-01

Background Pseudomonas aeruginosa lung infections are a huge problem in ventilator-associated pneumonia, cystic fibrosis (CF) and in chronic obstructive pulmonary disease (COPD) exacerbations. This bacterium secretes virulence factors that may subvert host innate immunity. Objective We evaluated the effect of P. aeruginosa elastase LasB, an important virulence factor secreted by the type II secretion system, on ion transport, innate immune responses and epithelial repair, both in vitro and in vivo. Methods Wild-type (WT) or cystic fibrosis transmembrane conductance regulator (CFTR)-mutated epithelial cells (cell lines and primary cells from patients) were treated with WT or ΔLasB pseudomonas aeruginosa O1 (PAO1) secretomes. The effect of LasB and PAO1 infection was also assessed in vivo in murine models. Results We showed that LasB was the most abundant protein in WT PAO1 secretomes and that it decreased epithelial CFTR expression and activity. In airway epithelial cell lines and primary bronchial epithelial cells, LasB degraded the immune mediators interleukin (IL)-6 and trappin-2, an important epithelial-derived antimicrobial molecule. We further showed that an IL-6/STAT3 signalling pathway was downregulated by LasB, resulting in inhibition of epithelial cell repair. In mice, intranasally instillated LasB induced significant weight loss, inflammation, injury and death. By contrast, we showed that overexpression of IL-6 and trappin-2 protected mice against WT-PAO1-induced death, by upregulating IL-17/IL-22 antimicrobial and repair pathways. Conclusions Our data demonstrate that PAO1 LasB is a major P. aeruginosa secreted factor that modulates ion transport, immune response and tissue repair. Targeting this virulence factor or upregulating protective factors such as IL-6 or antimicrobial molecules such as trappin-2 could be beneficial in P. aeruginosa-infected individuals. PMID:28790180

Coordination and Symmetry Patterns During the Drop Vertical Jump in People With Chronic Ankle Instability and Lateral Ankle Sprain Copers.

PubMed

Doherty, Cailbhe; Bleakley, Chris; Hertel, Jay; Caulfield, Brian; Ryan, John; Sweeney, Kevin; Patterson, Matthew R; Delahunt, Eamonn

2016-08-01

The drop vertical jump (DVJ) task has previously been used to identify movement patterns associated with a number of injury types. However, no current research exists evaluating people with chronic ankle instability (CAI) compared with people coping with lateral ankle sprain (LAS) (referred to as "LAS copers") during this task. The aim of this study was to identify the coping movement and motor control patterns of LAS copers in comparison with individuals with CAI during the DVJ task. This was a case-control study. Seventy individuals were recruited at convenience within 2-weeks of sustaining a first-time acute LAS injury. One year following recruitment, these individuals were stratified into 2 groups: 28 with CAI and 42 LAS copers. They attended the testing laboratory to complete a DVJ task. Three-dimensional kinematic and sagittal-plane kinetic profiles were plotted for the lower extremity joints of both limbs for the drop jump phase (phase 1) and drop landing phase (phase 2) of the DVJ. The rate of impact modulation relative to body weight during both phases of the DVJ also was determined. Compared with LAS copers, participants with CAI displayed significant increases in hip flexion on their "involved" limb during phase 1 of the DVJ (23° vs 18°) and bilaterally during phase 2 (15° vs 10°). These movement patterns coincided with altered moment-of-force patterns at the hip on the "uninvolved" limb. It is unknown whether these movement and motor control patterns preceded or occurred as a result of the initial LAS injury. Participants with CAI displayed hip-centered changes in movement and motor control patterns during a DVJ task compared with LAS copers. The findings of this study may give an indication of the coping mechanism underlying outcome following initial LAS injury. © 2016 American Physical Therapy Association.

Proceedings of the Conference on the Design of Experiments in Army Research Development and Testing (30th) Held at Las Cruces, New Mexico on 17-19 October 1984

DTIC Science & Technology

1985-07-01

Range, New Moxico HELD AT New Mexico State University Las Cruces, New Mexico 17-19 October 1984 Approved for public release; distribution unlimited...conducted on the campus of its co-host, the New Mexico State University (NMSU) in Las Cruces, New Mexico . This proved to be an ideal arrangement, and members...Science I.aboratory New Mexico State University Las Cruces, New Mexico * * *, * * Wedimusday, 17 October * * * * * U0l5-0916 REGISTRATIUN t. U9I5-U9jU

Contribución al flujo infrarrojo de las estrellas Be de la recombinación dielectrónica del MgII

NASA Astrophysics Data System (ADS)

Cruzado, A.; di Rocco, H.; Ringuelet, A.

Para evaluar la contribución del proceso de recombinación dielectrónica del átomo de MgII al exceso de flujo infrarrojo observado en las estrellas Be, calculamos la energía emitida en las líneas originadas por este proceso. Se evaluaron los efectos de las condiciones físicas del medio, como la temperatura electrónica y la densidad electrónica, sobre el flujo emitido. Se consideró también la influencia de una posible opacidad.

PubMed

Marzán-Rodríguez, Melissa; Varas-Díaz, Nelson

2006-01-01

El Virus de Inmunodeficiencia Humana (VIH) y el Síndrome de Inmunodeficiencia Adquirida (SIDA) han sido motivo de estigmatización para las personas que viven con ellos. Esta estigmatización se ha estudiado consecuentemente desde la perspectiva de opiniones de agentes estigmatizantes. Estas opiniones han obviado sistemáticamente el rol de las emociones en el proceso de estigmatización. Llevamos a cabo este estudio con el propósito de identificar el rol de las emociones en el proceso de estigmatización de las personas que viven con el virus (PVVS) por parte de profesionales de la salud. Para lograr este objetivo utilizamos un diseño exploratorio y cualitativo en el cual utilizamos la técnica de entrevistas semiestructuradas a profundidad. La muestra estuvo compuesta por 80 profesionales de la salud y estudiantes de las siguientes especialidades: psicología, trabajo social, medicina y enfermería. Los resultados reflejaron la existencia de emociones asociadas al VIH/SIDA tales como pena, lástima, compasión, asco, fobia y miedo entre los/as profesionales y estudiantes que participaron. Las personas participantes evidenciaron la necesidad de controlar sus emociones al interactuar con PVVS. Los resultados apuntan a la necesidad de explorar aquellos factores que mediatizan las emociones, tales como el contexto social en que se manifiestan y ante quiénes se revelan, para lograr entender a cabalidad el estigma que rodea al VIH/SIDA.

Adsorption/desorption of linear alkylbenzenesulfonate (LAS) and azoproteins by/from activated sludge flocs.

PubMed

Conrad, A; Cadoret, A; Corteel, P; Leroy, P; Block, J-C

2006-01-01

Our study investigated the adsorption/desorption by/from activated sludge flocs, dispersed in river water or in diluted wastewater, of organic compounds (C(11)-LAS, azoalbumin and azocasein) at concentrations relevant to environmental conditions. Activated sludge flocs, used as a model of biological aggregates, are characterized by a very heterogeneous matrix able to sorb the three organic compounds tested at 4 degrees C. The adsorbed amount of C(11)-LAS by activated sludge flocs was higher than that of azocasein or azoalbumin, as shown by the Freundlich parameters (K(ads)=8.6+/-1.7, 1.6+/-0.3 and 0.3+/-0.1 micromol(1-1/n)g(-1)l(1/n) for C(11)-LAS, azocasein and azoalbumin, respectively; n=3 sludges). C(11)-LAS sorption from activated sludge appeared to be partially reversible in river water, while a marked hysteresis phenomenon was observed for azocasein and azoalbumin, implying a low degree of reversibility in their exchange between activated sludge and river water. It has also been displayed that the conductivity variation of bulk water (comprised between 214 and 838 microS cm(-1)) exerted no dramatic effect on the C(11)-LAS desorption from activated sludge flocs, while a little effect of it on azocasein desorption was observed. Thus, biological aggregates as activated sludge flocs can serve as an intermediate carrier for C(11)-LAS, while it represents a sink for proteins.

Low performance on mathematical tasks in preschoolers: the importance of domain-general and domain-specific abilities.

PubMed

Costa, H M; Nicholson, B; Donlan, C; Van Herwegen, J

2018-04-01

Different domain-specific and domain-general cognitive precursors play a key role in the development of mathematical abilities. The contribution of these domains to mathematical ability changes during development. Primary school-aged children who show mathematical difficulties form a heterogeneous group, but it is not clear whether this also holds for preschool low achievers (LAs) and how domain-specific and domain-general abilities contribute to mathematical difficulties at a young age. The aim of this study was to explore the cognitive characteristics of a sample of preschool LAs and identify sub-types of LAs. 81 children were identified as LAs from 283 preschoolers aged 3 to 5 years old and were assessed on a number of domain-general and domain-specific tasks. Cluster analysis revealed four subgroups of LAs in mathematics: (1) a weak processing sub-type; (2) a general mathematical LAs sub-type; (3) a mixed abilities sub-type; and (4) a visuo-spatial deficit sub-type. Whilst two of the groups showed specific domain-general difficulties, none showed only domain-specific difficulties. Current findings suggest that preschool LAs constitute a heterogeneous group and stress the importance of domain-general factors for the development of mathematical abilities during the preschool years. © 2018 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

Modos de produccion cientifica: Culturas y metodologias de investigacion en la Universidad de Cadiz

NASA Astrophysics Data System (ADS)

Gonzalez Ramos, Ana M.

2004-12-01

Este trabajo de investigacion supone un modelo teorico de caracter aplicado, que proporciona la oportunidad de evaluar la produccion cientifica de los investigadores. Se encuadra dentro de la tradiccion de la estadistica aplicada y la sociologia del conocimiento. Atiende especialmente a dos conjuntos de temas de interes, por una parte, las caracteristicas principales que determinan el nivel y tipo de produccion academica producida por las unidades de investigacion y por los propios investigadores; por otra, la utilizacion que se hace de los metodos y tecnicas de investigacion puesto que de ello tambien depende el modo de produccion cientifica. Los puntos novedosos de esta tesis son: la medicion cuantitativa del objeto de estudio, la suma de los productos y las condiciones externas a la produccion del conocimiento mas otros elementos internos como las caracteristicas de los investigadores y la metodologia utilizada para desarrollar sus trabajos; y, finalmente, el uso de las nuevas tecnologias. El aprovechamiento de los recursos estadisticos y las fuentes de informacion secundarias se complementan con el diseno propio de una encuesta donde se implementa las caracteristicas descritas en un capitulo anterior sobre los metodos cientificos mas idoneos descritos en los principales manuales y articulos cientificos desde distintas disciplinas de conocimiento. Dicha encuesta ha sido desarrollada como un programa propio y en base a los mas innovadores usos de la tecnologia en la metodologia de encuestas.

Identification of persisten anionic surfactant-derived chemicals in sewage effluent and groundwater

USGS Publications Warehouse

Field, J.A.; Leenheer, J.A.; Thorn, K.A.; Barber, L.B.; Rostad, C.; Macalady, D.L.; Daniel, S.R.

1992-01-01

Preparative isolation and fractionation procedures coupled with spectrometric analyses were used to identify surfactant-derived contaminants in sewage effluent and sewage-contaminated groundwater from a site located on Cape Cod, Massachusetts. Anionic surfactants and their biodegradation intermediates were isolated from field samples by ion exchange and fractionated by solvent extraction and adsorption chromatography. Fractions were analyzed by 13C nuclear magnetic resonance spectrometry and gas chromatography-mass spectrometry. Carboxylated residues of alkylphenol polyethoxylate surfactants were detected in sewage effluent and contaminated groundwater. Linear alkylbenzenesulfonates (LAS) were identified in sewage effluent and groundwater. Groundwater LAS composition suggested preferential removal of select isomers and homologs due to processes of biodegradation and partitioning. Tetralin and indane sulfonates (DATS), alicyclic analogs of LAS, were also identified in field samples. Although DATS are a minor portion of LAS formulations, equivalent concentrations of LAS and DATS in groundwater suggested persistence of alicyclic contaminant structures over those of linear structure. Sulfophenyl-carboxylated (SPC) LAS biodegradation intermediates were determined in sewage effluent and groundwater. Homolog distributions suggested that SPC containing 3-10 alkyl-chain carbons persist during infiltration and groundwater transport. Surfactant-derived residues detected in well F300-50 groundwater have a minimum residence time in the range of 2.7-4.6 yr. LAS detected in groundwater at 500 m from infiltration has been stable over an estimated 50-500 half lives.

Identification of persistent anionic surfactant-derived chemicals in sewage effluent and groundwater

USGS Publications Warehouse

Field, Jennifer A.; Leenheer, Jerry A.; Thorn, Kevin A.; Barber, Larry B.; Rostad, Colleen; Macalady, Donald L.; Daniel, Stephen R.

1992-01-01

Preparative isolation and fractionation procedures coupled with spectrometric analyses were used to identify surfactant-derived contaminants in sewage effluent and sewage-contaminated groundwater from a site located on Cape Cod, Massachusetts. Anionic surfactants and their biodegradation intermediates were isolated from field samples by ion exchange and fractionated by solvent extraction and adsorption chromatography. Fractions were analyzed by 13C nuclear magnetic resonance spectrometry and gas chromatography-mass spectrometry. Carboxylated residues of alkylphenol polyethoxylate surfactants were detected in sewage effluent and contaminated groundwater. Linear alkylbenzenesulfonates (LAS) were identified in sewage effluent and groundwater. Groundwater LAS composition suggested preferential removal of select isomers and homologs due to processes of biodegradation and partitioning. Tetralin and indane sulfonates (DATS), alicyclic analogs of LAS, were also identified in field samples. Although DATS are a minor portion of LAS formulations, equivalent concentrations of LAS and DATS in groundwater suggested persistence of alicyclic contaminant structures over those of linear structure. Sulfophenyl-carboxylated (SPC) LAS biodegradation intermediates were determined in sewage effluent and groundwater. Homolog distributions suggested that SPC containing 3–10 alkyl-chain carbons persist during infiltration and groundwater transport. Surfactant-derived residues detected in well F300-50 groundwater have a minimum residence time in the range of 2.7–4.6 yr. LAS detected in groundwater at 500 m from infiltration has been stable over an estimated 50–500 half lives.

Nuanced Understandings of Privatization in Local Authorities' Services to Schools

ERIC Educational Resources Information Center

Boyask, Ruth

2015-01-01

This article draws upon findings from the New Relations between Local Authorities (LAs) and Schools project to identify ideological and value-based differences between the models of service to schools adopted within four case study LAs. While each of the LAs has developed a privatized model of service, there are subtle differences between the…

77 FR 65332 - Proposed Modification of Class B Airspace; Las Vegas, NV

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-26

...[deg]51'43'' W.); thence counterclockwise along the 16 DME arc to the point of beginning. Area E. That...). SUMMARY: This action proposes to modify the Las Vegas, NV, Class B airspace area to ensure the containment..., and reduce the potential for midair collision in the Las Vegas terminal area. DATES: Comments must be...

Las actualizaciones a la apariencia de espanol.epa.gov

EPA Pesticide Factsheets

Información sobre 2016 la actualización de las páginas del sitio web de la EPA en español e inglés para facilitar la navegación y la usabilidad. Los cambios notables son en la apariencia de dichas páginas. No afectan al contenido de las mismas.

Accretion of Grenvillian terranes to the southwestern border of the Río de la Plata craton, western Argentina

NASA Astrophysics Data System (ADS)

Varela, Ricardo; Basei, Miguel A. S.; González, Pablo D.; Sato, Ana M.; Naipauer, Maximiliano; Campos Neto, Mario; Cingolani, Carlos A.; Meira, Vinicius T.

2011-04-01

A comprehensive review of the geological, geochronological, and isotopic features of the Mesoproterozoic Grenvillian terranes attached to the southwest of the Río de la Plata craton in Early Paleozoic times is presented in this paper. They are grouped into the northern (sierras de Umango, Maz and del Espinal and surroundings), central (Sierra de Pie de Palo, southern Precordillera and Frontal Cordillera), and southern (San Rafael and Las Matras Blocks) segments. The Mesoproterozoic basement consists mainly of arc related, intermediate to acidic and mafic-ultramafic rocks of 1,244-1,027 Ma, with juvenile, Laurentian affinity. Exception to it is the Maz Group, with a protracted history and reworked character. They are affected by 846-570 Ma, extensional magmatism in the northern and central segments, which represents the Neoproterozoic breakup of the Rodinia supercontinent. Successive passive margin sedimentation is registered in Late Neoproterozoic (~640-580 Ma) and Cambro-Ordovician (~550-470 Ma) times. The southern segment is noted for the younger sedimentation alone, and for showing the exclusive primary unconformable relationship between the Mesoproterozoic basement and Early Ordovician cover. The effects of Early Paleozoic Famatinian orogeny, associated with the collisions of Cuyania and Chilenia terranes, are recorded as main phase (480-450 Ma), late phase (440-420 Ma), and Chanic phase (400-360 Ma). Among them, the tectonothermal climax is the Ordovician main phase, to which klippe and nappe structures typical of collisional orogens are related in the northern and central segments. Preliminary data allow us to suggest a set of paired metamorphic belts, with an outboard high-P/T belt, and an inboard Barrowian P/T belt.