WorldWideScience

Sample records for polyploid south american

  1. Ecological range shift in the polyploid members of the South American genus Fosterella (Bromeliaceae).

    Science.gov (United States)

    Paule, Juraj; Wagner, Natascha D; Weising, Kurt; Zizka, Georg

    2017-08-01

    The distribution of polyploidy along a relatively steep Andean elevation and climatic gradient is studied using the genus Fosterella L.B. Sm. (Bromeliaceae) as a model system. Ecological differentiation of cytotypes and the link of polyploidy with historical biogeographic processes such as dispersal events and range shift are assessed. 4',6-Diamidino-2-phenylindole (DAPI) staining of nuclei and flow cytometry were used to estimate the ploidy levels of 159 plants from 22 species sampled throughout the distribution range of the genus. Ecological differentiation among ploidy levels was tested by comparing the sets of climatic variables. Ancestral chromosome number reconstruction was carried out on the basis of a previously generated phylogeographic framework. This study represents the first assessment of intrageneric, intraspecific and partially intrapopulational cytotype diversity in a genus of the Bromeliaceae family. In Fosterella , the occurrence of polyploidy was limited to the phylogenetically isolated penduliflora and rusbyi groups. Cytotypes were found to be ecologically differentiated, showing that polyploids preferentially occupy colder habitats with high annual temperature variability (seasonality). The combined effects of biogeographic history and adaptive processes are presumed to have shaped the current cytotype distribution in the genus. The results provide indirect evidence for both adaptive ecological and non-adaptive historical processes that jointly influenced the cytotype distribution in the predominantly Andean genus Fosterella (Bromeliaceae). The results also exemplify the role of polyploidy as an important driver of speciation in a topographically highly structured and thus climatically diverse landscape. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  2. Basic chromosome numbers and polyploid levels in some South African and Australian grasses (Poaceae

    Directory of Open Access Journals (Sweden)

    J. J. Spies

    1991-10-01

    Full Text Available Chromosome numbers of 46 specimens of grasses, involving 24 taxa from South Africa and Australia, have been determined during the present study. For the first time chromosome numbers are given for Eragrostis sarmentosa (Thunb. Trin. (n = 20. Panicum aequinerve Nees (n = 18,  Digitaria argyrograpta (Nees Stapf (n = 9 and D. maitlandii Stapf & C.E. Hubb. (n = 9. Additional polyploid levels are described for Diplachne fusca (L. Beauv. ex Roem. & Schult. (n = 10 and Digitaria diagonalis (Nees Stapf var.  diagonalis (n = 9. B-chromosomes were observed in several different specimens. The presence of B-chromosomes often results in abnormal chromosomal behaviour during meiosis.

  3. Ribosomal DNA, heterochromatin, and correlation with genome size in diploid and polyploid North American endemic sagebrushes (Artemisia, Asteraceae)

    Science.gov (United States)

    Sonia Garcia; Teresa Garnatje; Jaume Pellicer; E. Durant McArthur; Sonja Siljak-Yakovlev; Joan Valles

    2009-01-01

    Subgenus Tridentatae (Artemisia, Asteraceae) can be considered a polyploid complex. Both polyploidy and hybridization have been documented in the Tridentatae. Fluorescent in situ hybridization (FISH) and fluorochrome banding were used to detect and analyze ribosomal DNA changes linked to polyploidization in this group by studying four diploidpolyploid species pairs. In...

  4. Polyploidization in liver tissue.

    Science.gov (United States)

    Gentric, Géraldine; Desdouets, Chantal

    2014-02-01

    Polyploidy (alias whole genome amplification) refers to organisms containing more than two basic sets of chromosomes. Polyploidy was first observed in plants more than a century ago, and it is known that such processes occur in many eukaryotes under a variety of circumstances. In mammals, the development of polyploid cells can contribute to tissue differentiation and, therefore, possibly a gain of function; alternately, it can be associated with development of disease, such as cancer. Polyploidy can occur because of cell fusion or abnormal cell division (endoreplication, mitotic slippage, or cytokinesis failure). Polyploidy is a common characteristic of the mammalian liver. Polyploidization occurs mainly during liver development, but also in adults with increasing age or because of cellular stress (eg, surgical resection, toxic exposure, or viral infections). This review will explore the mechanisms that lead to the development of polyploid cells, our current state of understanding of how polyploidization is regulated during liver growth, and its consequence on liver function. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  5. The palaeobiogeography of South American gomphotheres

    Directory of Open Access Journals (Sweden)

    Spencer G. Lucas

    2013-01-01

    Full Text Available Gomphotheriid proboscideans reached South America as Late Cenozoic immigrants from North America. However, disagreements over alpha taxonomy, age dating and phylogenetic relationships have produced three competing hypotheses about this immigration: (1 a single gomphothere immigration took place soon after the ~3 Ma closure of the Panamanian isthmus; (2 two separate gomphothere immigrations took place after closure of the isthmus; or (3 an earlier, Late Miocene (before 9 Ma immigration brought gomphotheres into South America. A critical re-evaluation of the alpha taxonomy, age dating and phylogenetic relationships of Neotropical gomphotheres identifies two valid genera of South American gomphotheres, Cuvieronius and Notiomastodon (= “Haplomastodon”, = “Stegomastodon” from South America and recognizes “Amahuacatherium” as an invalid genus likely based on a specimen of Notiomastodon. The oldest well-dated South American gomphothere fossil is Marplatan, ~2.5 Ma, from Argentina. The case for an age of “Amahuacatherium” older than 9 Ma is refuted by mammalian biostratigraphy and a re-evaluation of the relevant magnetostratigraphy. North American Rhynchotherium descended from Gomphotherium during the Late Hemphillian (~5–6 Ma and gave rise to Cuvieronius in North America by the end of the Blancan (~2 Ma time. Notiomastodon evolved from Cuvieronius in South America during the Pleistocene. The case for a close relationship between the Neotropical gomphotheres and Sinomastodon from China is rejected. Central America was not a center of endemic gomphothere evolution and merely acted as a pathway for the immigration of gomphotheres from north to south: Gomphotherium into Central America during the Miocene, Cuvieronius to Central America by Early Pleistocene time and on to South America. After closure of the Panamanian isthmus, Cuvieronius immigrated to South America, where it gave rise to Notiomastodon by Middle Pleistocene time. The

  6. Gallbladder cancer: South American experience.

    Science.gov (United States)

    Arroyo, Gerardo F; Gentile, Alberto; Parada, Luis A

    2016-10-01

    Large differences in terms of incidence and mortality due to gallbladder cancer (GBC) have been reported worldwide. Moreover, it seems that GBC has unique characteristics in South America. We surveyed the literature looking for information about the epidemiology, basic and translational research, and clinical trials performed in South America in order to critically analyze the magnitude of this health problem in the region. Compared to other geographic areas, age-standardized mortality rates (ASMR) for GBC in women are very high, particularly in many western areas of South America. Genetic, as well as dietary and environmental factors likely contribute to the pathogenesis of this disease in the area. Compared to other regions the profile of abnormalities of key genes such as KRAS and TP53 in GBC seems to slightly differ in South America, while the clinical behavior appears to be similar with a median overall survival (OS) of 6.5 to 8 months in advanced GBC. In contrast to Europe and USA, prophylactic cholecystectomy is a common practice in western areas of South America. GBC particularly affects women in South America, and represents a significant public health problem. It appears to have peculiarities that pose an urgent need for additional research aimed to discover risk factors, molecular events associated with its development and new treatment options for this lethal disease.

  7. Spontaneous polyploidization in cucumber.

    Science.gov (United States)

    Ramírez-Madera, Axel O; Miller, Nathan D; Spalding, Edgar P; Weng, Yiqun; Havey, Michael J

    2017-07-01

    This is the first quantitative estimation of spontaneous polyploidy in cucumber and we detected 2.2% polyploids in a greenhouse study. We provide evidence that polyploidization is consistent with endoreduplication and is an on-going process during plant growth. Cucumber occasionally produces polyploid plants, which are problematic for growers because these plants produce misshaped fruits with non-viable seeds. In this study, we undertook the first quantitative study to estimate the relative frequency of spontaneous polyploids in cucumber. Seeds of recombinant inbred lines were produced in different environments, plants were grown in the field and greenhouse, and flow cytometry was used to establish ploidies. From 1422 greenhouse-grown plants, the overall relative frequency of spontaneous polyploidy was 2.2%. Plants possessed nuclei of different ploidies in the same leaves (mosaic) and on different parts of the same plant (chimeric). Our results provide evidence of endoreduplication and polysomaty in cucumber, and that it is an on-going and dynamic process. There was a significant effect (p = 0.018) of seed production environment on the occurrence of polyploid plants. Seed and seedling traits were not accurate predictors of eventual polyploids, and we recommend that cucumber producers rogue plants based on stature and leaf serration to remove potential polyploids.

  8. Review of South American mines

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    A general overview is presented of the mining activity and plans for South America. The countries which are presented are Columbia, Argentina, Brazil, Venezuela, Chile, Peru, and Bolivia. The products of the mines include coal, bauxite, gold, iron, uranium, copper and numerous other minor materials. A discussion of current production, support and processing facilities, and mining strategies is also given

  9. Polyploidization of liver cells.

    Science.gov (United States)

    Celton-Morizur, Séverine; Desdouets, Chantal

    2010-01-01

    Eukaryotic organisms usually contain a diploid complement of chromosomes. However, there are a number of exceptions. Organisms containing an increase in DNA content by whole number multiples of the entire set of chromosomes are defined as polyploid. Cells that contain more than two sets of chromosomes were first observed in plants about a century ago and it is now recognized that polyploidy cells form in many eukaryotes under a wide variety of circumstance. Although it is less common in mammals, some tissues, including the liver, show a high percentage of polyploid cells. Thus, during postnatal growth, the liver parenchyma undergoes dramatic changes characterized by gradual polyploidization during which hepatocytes of several ploidy classes emerge as a result of modified cell-division cycles. This process generates the successive appearance of tetraploid and octoploid cell classes with one or two nuclei (mononucleated or binucleated). Liver cells polyploidy is generally considered to indicate terminal differentiation and senescence and to lead both to the progressive loss of cell pluripotency and a markedly decreased replication capacity. In adults, liver polyploidization is differentially regulated upon loss of liver mass and liver damage. Interestingly, partial hepatectomy induces marked cell proliferation followed by an increase in liver ploidy. In contrast, during hepatocarcinoma (HCC), growth shifts to a nonpolyploidizing pattern and expansion of the diploid hepatocytes population is observed in neoplastic nodules. Here we review the current state of understanding about how polyploidization is regulated during normal and pathological liver growth and detail by which mechanisms hepatocytes become polyploid.

  10. DNA damage and polyploidization.

    Science.gov (United States)

    Chow, Jeremy; Poon, Randy Y C

    2010-01-01

    A growing body of evidence indicates that polyploidization triggers chromosomal instability and contributes to tumorigenesis. DNA damage is increasingly being recognized for its roles in promoting polyploidization. Although elegant mechanisms known as the DNA damage checkpoints are responsible for halting the cell cycle after DNA damage, agents that uncouple the checkpoints can induce unscheduled entry into mitosis. Likewise, defects of the checkpoints in several disorders permit mitotic entry even in the presence of DNA damage. Forcing cells with damaged DNA into mitosis causes severe chromosome segregation defects, including lagging chromosomes, chromosomal fragments and chromosomal bridges. The presence of these lesions in the cleavage plane is believed to abort cytokinesis. It is postulated that if cytokinesis failure is coupled with defects of the p53-dependent postmitotic checkpoint pathway, cells can enter S phase and become polyploids. Progress in the past several years has unraveled some of the underlying principles of these pathways and underscored the important role of DNA damage in polyploidization. Furthermore, polyploidization per se may also be an important determinant of sensitivity to DNA damage, thereby may offer an opportunity for novel therapies.

  11. STUDIES ON SOUTH AMERICAN YELLOW FEVER

    Science.gov (United States)

    Davis, Nelson C.; Shannon, Raymond C.

    1929-01-01

    Yellow fever virus from M. rhesus has been inoculated into a South American monkey (Cebus macrocephalus) by blood injection and by bites of infected mosquitoes. The Cebus does not develop the clinical or pathological signs of yellow fever. Nevertheless, the virus persists in the Cebus for a time as shown by the typical symptoms and lesions which develop when the susceptible M. rhesus is inoculated from a Cebus by direct transfer of blood or by mosquito (A. aegypti) transmission. PMID:19869607

  12. An introduction to South American camelids

    International Nuclear Information System (INIS)

    Urquieta, B.; Rojas, J.R.

    1990-01-01

    The South American camelids - the domesticated alpaca and llama, and the wild vicuna and guanaco - which belong to the Camelidae family of the Artiodactyla order are of considerable sociological, economic and ecological importance to the native populations living in the high plateau (altiplano) of the central Andes. Owing to their biological characteristics they are able to provide meat, wool, hides and transportation without disrupting the fragile ecosystem. Increasing interest is being taken in these animals, both in their native lands of Argentina, Bolivia, Chile and Peru and in other parts of the world. (author). 55 refs, 5 figs

  13. The American South in the Atlantic World

    DEFF Research Database (Denmark)

    decisively shaped the history and culture of the American South from colonial times to the modern era. The essays in this interdisciplinary volume examine a wide range of topics, including race, migration, religion, law, slavery, emancipation, literature, memoir, popular culture, and ethnography. At a time...... when there is growing emphasis on globalizing southern studies the collection both demonstrates and critiques the value of Atlantic World perspectives on the region. Equally important, the mix of case studies and state-of-the field essays combines the latest historical thinking on the South’s myriad...

  14. Curare: the South American arrow poison.

    Science.gov (United States)

    Lee, M R

    2005-02-01

    The history of curare is both curious and convoluted. A product of South American culture it emerged in the sixteenth century from the mists of antiquity at the same time as quinine, coca, and chocolate. Like quinine, at first came the extract but no plant, and later the plant but no chemical compound. It took more than 300 years and the efforts of many explorers and scientists to resolve the problem. These included Condamine, Humboldt, Brodie, Waterton, Bernard, Dale, Walker, and King. Finally, the pure compound d-tubocurarine was isolated from the liana Chondrodendron and synthesised. Its specific physiological action was blockade of the effect of acetylcholine at the neuro-muscular junction. Such a paralytic poison could be used to kill oneself or others. The bizarre plot to kill the Prime Minister, Lloyd George, during the First World War is described. Fortunately this nefarious plan was thwarted by the Secret Service!

  15. Chromosomes of South American Bufonidae (Amphibia, Anura Chromosomes of South American Bufonidae (Amphibia, Anura

    Directory of Open Access Journals (Sweden)

    Brum Zorrilla N.

    1973-09-01

    Full Text Available Karyotypes of eight of South American Bufonidae were studied: B.ictericus, B. spinulosus spinulosus, B. arenarum, B. g. fernandezae, B. g. d'orbignyi, B. crucifer, B. paracnemis and B. marinus. In all species 2n = 22 chromosomes were found. Neither heteromorphic pairs of chromosomes nor bivalents with characteristic morphology and behavior of sex chromosomesduring male meiosis were observed in any species.Karyotypes of eight of South American Bufonidae were studied: B.ictericus, B. spinulosus spinulosus, B. arenarum, B. g. fernandezae, B. g. d'orbignyi, B. crucifer, B. paracnemis and B. marinus. In all species 2n = 22 chromosomes were found. Neither heteromorphic pairs of chromosomes nor bivalents with characteristic morphology and behavior of sex chromosomesduring male meiosis were observed in any species.

  16. [Endo- and ectoparasites of South American camelids and their control].

    Science.gov (United States)

    Schmäschke, R

    2015-01-01

    In a literature review, common endo- and ectoparasites of South American camelids are described, presenting morphological details and clinical signs important for diagnosis. Based on the life cycle of the parasites, possibilities for prophylaxis and therapy are indicated. The review should aid the veterinarian to diagnose and control common parasitic infections in South American camelids.

  17. Mutation spectrum in South American Lynch syndrome families

    DEFF Research Database (Denmark)

    Dominguez-Valentin, Mev; Nilbert, Mef; Wernhoff, Patrik

    2013-01-01

    Genetic counselling and testing for Lynch syndrome have recently been introduced in several South American countries, though yet not available in the public health care system.......Genetic counselling and testing for Lynch syndrome have recently been introduced in several South American countries, though yet not available in the public health care system....

  18. Megakaryocyte and polyploidization.

    Science.gov (United States)

    Mazzi, Stefania; Lordier, Larissa; Debili, Najet; Raslova, Hana; Vainchenker, William

    2018-01-01

    In mammals, platelets are produced in the blood by cytoplasmic fragmentation of megakaryocytes (MKs). Platelet production is thus dependent on both the MK number and size. During differentiation, MKs switch from a division by mitosis to polyploidization by endomitosis to increase their size. The endomitotic process includes several successive rounds of DNA replication with an entry in mitosis with a failure in late cytokinesis and a defect in karyokinesis. This leads to a giant cell with a modal ploidy at 16N and one multilobulated nucleus. The entire genome is duplicated several times and all alleles remain functional producing a hypermetabolic cell. A defect in abscission explains the cytokinesis failure and is related to an altered accumulation of actomyosin at the cleavage furrow as a consequence of both a low local RhoA activity and silencing of the MYH10 gene. This mechanism is regulated by transcription factors that govern differentiation explaining the intricacies of both processes. However, the endomitotic cell cycle regulation is still incompletely understood, particularly mitosis entry, escape to the tetraploid checkpoint, and defect in karyokinesis. Polyploidization is regulated during ontogeny, the first embryonic MKs being 2N. The molecular mechanism of this embryo-fetal/adult transition is beginning to be understood. In physiological conditions, MK ploidy is increased by an enhanced platelet demand through the thrombopoietin/myeloproliferative leukemia axis. In numerous hematologic malignancies, MK ploidy decreases, but it is always associated with a defect in MK differentiation. It has been proposed that polyploidization induction could be a treatment for some malignant MK disorders. Copyright © 2018 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

  19. Physiological significance of polyploidization in mammalian cells.

    Science.gov (United States)

    Pandit, Shusil K; Westendorp, Bart; de Bruin, Alain

    2013-11-01

    Programmed polyploidization occurs in all mammalian species during development and aging in selected tissues, but the biological properties of polyploid cells remain obscure. Spontaneous polyploidization arises during stress and has been observed in a variety of pathological conditions, such as cancer and degenerative diseases. A major challenge in the field is to test the predicted functions of polyploidization in vivo. However, recent genetic mouse models with diminished polyploidization phenotypes represent novel, powerful tools to unravel the biological function of polyploidization. Contrary to a longstanding hypothesis, polyploidization appears to not be required for differentiation and has no obvious impact on proliferation. Instead, polyploidization leads to increased cell size and genetic diversity, which could promote better adaptation to chronic injury or stress. We discuss here the consequences of reducing polyploidization in mice and review which stress responses and molecular signals trigger polyploidization during development and disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. South American climate during the Last Glacial Maximum: Delayed onset of the South American monsoon

    Science.gov (United States)

    Cook, K. H.; Vizy, E. K.

    2006-01-01

    The climate of the Last Glacial Maximum (LGM) over South America is simulated using a regional climate model with 60-km resolution, providing a simulation that is superior to those available from global models that do not resolve the topography and regional-scale features of the South American climate realistically. LGM conditions on SST, insolation, vegetation, and reduced atmospheric CO2 on the South American climate are imposed together and individually. Remote influences are not included. Annual rainfall is 25-35% lower in the LGM than in the present day simulation throughout the Amazon basin. A primary cause is a 2-3 month delay in the onset of the rainy season, so that the dry season is about twice as long as in the present day. The delayed onset occurs because the low-level inflow from the tropical Atlantic onto the South American continent is drier than in the present day simulation due to reduced evaporation from cooler surface waters, and this slows the springtime buildup of moist static energy that is needed to initiate convection. Once the monsoon begins in the Southern Hemisphere, LGM rainfall rates are similar to those in the present day. In the Northern Hemisphere, however, rainfall is lower throughout the (shortened) rainy season. Regional-scale structure includes slight precipitation increases in the Nordeste region of Brazil and along the eastern foothills of the Andes, and a region in the center of the Amazon basin that does not experience annual drying. In the Andes Mountains, the signal is complicated, with regions of significant rainfall increases adjacent to regions with reduced precipitation.

  1. Optimizing megakaryocyte polyploidization by targeting multiple pathways of cytokinesis.

    Science.gov (United States)

    Avanzi, Mauro P; Chen, Amanda; He, Wu; Mitchell, W Beau

    2012-11-01

    Large-scale in vitro production of platelets (PLTs) from cord blood stem cells is one goal of stem cell research. One step toward this goal will be to produce polyploid megakaryocytes capable of releasing high numbers of PLTs. Megakaryocyte polyploidization requires distinct cytoskeletal and cellular mechanisms, including actin polymerization, myosin activation, microtubule formation, and increased DNA production. In this study we variably combined inhibition of these principal mechanisms of cytokinesis with the goal of driving polyploidization in megakaryocytes. Megakaryocytes were derived from umbilical cord blood and cultured with reagents that inhibit distinct mechanisms of cytokinesis: Rho-Rock inhibitor (RRI), Src inhibitor (SI), nicotinamide (NIC), aurora B inhibitor (ABI), and myosin light chain kinase inhibitor (MLCKI). Combinations of reagents were used to determine their interactions and to maximize megakaryocyte ploidy. Treatment with RRI, NIC, SI, and ABI, but not with MLCKI, increased the final ploidy and RRI was the most effective single reagent. RRI and MLCKI, both inhibitors of MLC activation, resulted in opposite ploidy outcomes. Combinations of reagents also increased ploidy and the use of NIC, SI, and ABI was as effective as RRI alone. Addition of MLCKI to NIC, SI, and ABI reached the highest level of polyploidization. Megakaryocyte polyploidization results from modulation of a combination of distinct cytokinesis pathways. Reagents targeting distinct cytoskeletal pathways produced additive effects in final megakaryocyte ploidy. The RRI, however, showed no additive effect but produced a high final ploidy due to overlapping inhibition of multiple cytokinesis pathways. © 2012 American Association of Blood Banks.

  2. South American Youth and Integration : Typical Situations and Youth ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    South American Youth and Integration : Typical Situations and Youth ... IDRC partner the World Economic Forum is building a hub for inclusive growth ... Brazil, Paraguay and Uruguay) and their perception of rights, democracy and regional.

  3. Haemotrophic mycoplasmas in South American camelids in Switzerland

    OpenAIRE

    Kaufmann, C; Meli, Marina L; Robert, N; Willi, Barbara; Hofmann-Lehmann, Regina; Wengi, Nicole; Lutz, Hans; Zanolari, P

    2007-01-01

    The red blood cell parasite 'Candidatus Mycoplasma haemolamae', formerly Eperythrozoon, is known to be widespread in South American camelids in the USA, causing anaemia in affected animals. Up to now, haemotrophic mycoplasmas were not observed in South American camelids in Europe; however, they were known in a herd of alpacas in Switzerland and to identify them as 'Candidatus M. haemolamae'. Possible ways of transmission are discussed.

  4. Afrikaans, American and British Models for South African English ...

    African Journals Online (AJOL)

    tions in a national and international context, by comparing the traditions and the roles of the lan- ... The changing linguistic, social, and educational situations in South Africa ... abroad, by the British and American leXicographical traditions. ... interactional styles in the South African social psychology and cross-cultural.

  5. MicroRNA-122 regulates polyploidization in the murine liver.

    Science.gov (United States)

    Hsu, Shu-Hao; Delgado, Evan R; Otero, P Anthony; Teng, Kun-Yu; Kutay, Huban; Meehan, Kolin M; Moroney, Justin B; Monga, Jappmann K; Hand, Nicholas J; Friedman, Joshua R; Ghoshal, Kalpana; Duncan, Andrew W

    2016-08-01

    A defining feature of the mammalian liver is polyploidy, a numerical change in the entire complement of chromosomes. The first step of polyploidization involves cell division with failed cytokinesis. Although polyploidy is common, affecting ∼90% of hepatocytes in mice and 50% in humans, the specialized role played by polyploid cells in liver homeostasis and disease remains poorly understood. The goal of this study was to identify novel signals that regulate polyploidization, and we focused on microRNAs (miRNAs). First, to test whether miRNAs could regulate hepatic polyploidy, we examined livers from Dicer1 liver-specific knockout mice, which are devoid of mature miRNAs. Loss of miRNAs resulted in a 3-fold reduction in binucleate hepatocytes, indicating that miRNAs regulate polyploidization. Second, we surveyed age-dependent expression of miRNAs in wild-type mice and identified a subset of miRNAs, including miR-122, that is differentially expressed at 2-3 weeks, a period when extensive polyploidization occurs. Next, we examined Mir122 knockout mice and observed profound, lifelong depletion of polyploid hepatocytes, proving that miR-122 is required for complete hepatic polyploidization. Moreover, the polyploidy defect in Mir122 knockout mice was ameliorated by adenovirus-mediated overexpression of miR-122, underscoring the critical role miR-122 plays in polyploidization. Finally, we identified direct targets of miR-122 (Cux1, Rhoa, Iqgap1, Mapre1, Nedd4l, and Slc25a34) that regulate cytokinesis. Inhibition of each target induced cytokinesis failure and promoted hepatic binucleation. Among the different signals that have been associated with hepatic polyploidy, miR-122 is the first liver-specific signal identified; our data demonstrate that miR-122 is both necessary and sufficient in liver polyploidization, and these studies will serve as the foundation for future work investigating miR-122 in liver maturation, homeostasis, and disease. (Hepatology 2016

  6. Iberian (South American) Model of Judicial Review: Toward Conceptual Framework

    Science.gov (United States)

    Klishas, Andrey A.

    2016-01-01

    The paper explores Latin American countries legislation with the view to identify specific features of South American model of judicial review. The research methodology rests on comparative approach to analyzing national constitutions' provisions and experts' interpretations thereof. The constitutional provisions of Brazil, Peru, Mexico, and…

  7. The South American fruit fly, Anastrepha fraterculus (Wiedemann) in Brazil

    International Nuclear Information System (INIS)

    Zucchi, R.A.; Araujo, E.L.; Canal D, N.A.; Uchoa F, M.A.

    1999-01-01

    Anastrepha fraterculus, the South American fruit fly, is the most common and economically important pest for the fruit-bearing species in the Neotropical region. However, there are some species that are close to A. fraterculus and, sometimes they can be erroneously identified as A. fraterculus. The separation of A. fraterculus from A. obliqua, A. sororcula and A. zenildae, species closely related to South American fruit fly, is discussed. Also, information on the host plants and braconid parasitoids for A. fraterculus in Brazil is presented. (author)

  8. Glyphosate sustainability in South American cropping systems.

    Science.gov (United States)

    Christoffoleti, Pedro J; Galli, Antonio J B; Carvalho, Saul J P; Moreira, Murilo S; Nicolai, Marcelo; Foloni, Luiz L; Martins, Bianca A B; Ribeiro, Daniela N

    2008-04-01

    South America represents about 12% of the global land area, and Brazil roughly corresponds to 47% of that. The major sustainable agricultural system in South America is based on a no-tillage cropping system, which is a worldwide adopted agricultural conservation system. Societal benefits of conservation systems in agriculture include greater use of conservation tillage, which reduces soil erosion and associated loading of pesticides, nutrients and sediments into the environment. However, overreliance on glyphosate and simpler cropping systems has resulted in the selection of tolerant weed species through weed shifts (WSs) and evolution of herbicide-resistant weed (HRW) biotypes to glyphosate. It is a challenge in South America to design herbicide- and non-herbicide-based strategies that effectively delay and/or manage evolution of HRWs and WSs to weeds tolerant to glyphosate in cropping systems based on recurrent glyphosate application, such as those used with glyphosate-resistant soybeans. The objectives of this paper are (i) to provide an overview of some factors that influence WSs and HRWs to glyphosate in South America, especially in Brazil, Argentina and Paraguay soybean cropped areas; (ii) to discuss the viability of using crop rotation and/or cover crops that might be integrated with forage crops in an economically and environmentally sustainable system; and (iii) to summarize the results of a survey of the perceptions of Brazilian farmers to problems with WSs and HRWs to glyphosate, and the level of adoption of good agricultural practices in order to prevent or manage it. Copyright (c) 2008 Society of Chemical Industry.

  9. Craton Heterogeneity in the South American Lithosphere

    Science.gov (United States)

    Lloyd, S.; Van der Lee, S.; Assumpcao, M.; Feng, M.; Franca, G. S.

    2012-04-01

    We investigate structure of the lithosphere beneath South America using receiver functions, surface wave dispersion analysis, and seismic tomography. The data used include recordings from 20 temporary broadband seismic stations deployed across eastern Brazil (BLSP02) and from the Chile Ridge Subduction Project seismic array in southern Chile (CRSP). By jointly inverting Moho point constraints, Rayleigh wave group velocities, and regional S and Rayleigh wave forms we obtain a continuous map of Moho depth. The new tomographic Moho map suggests that Moho depth and Moho relief vary slightly with age within the Precambrian crust. Whether or not a correlation between crustal thickness and geologic age can be derived from the pre-interpolation point constraints depends strongly on the selected subset of receiver functions. This implies that using only pre-interpolation point constraints (receiver functions) inadequately samples the spatial variation in geologic age. We also invert for S velocity structure and estimate the depth of the lithosphere-asthenosphere boundary (LAB) in Precambrian South America. The new model reveals a relatively thin lithosphere throughout most of Precambrian South America (< 140 km). Comparing LAB depth with lithospheric age shows they are overall positively correlated, whereby the thickest lithosphere occurs in the relatively small Saõ Francisco craton (200 km). However, within the larger Amazonian craton the younger lithosphere is thicker, indicating that locally even larger cratons are not protected from erosion or reworking of the lithosphere.

  10. South American Youth : Regional Democracy-Building Dialogue ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    This project will undertake a comparative analysis of South American youth in the Mercosur countries (Argentina, Brazil, Paraguay and Uruguay) and their perception of rights, democracy and regional integration. Researchers will examine the meaning that young people, adults and mediators of youth demands attribute to ...

  11. Mitogenomic phylogeny, diversification, and biogeography of South American spiny rats

    DEFF Research Database (Denmark)

    Fabre, Pierre-Henri; Upham, Nathan S.; Emmons, Louise H.

    2017-01-01

    Echimyidae is one of the most speciose and ecologically diverse rodent families in the world, occupying a wide range of habitats in the Neotropics. However, a resolved phylogeny at the genus-level is still lacking for these 22 genera of South American spiny rats, including the coypu (Myocastorina...... Atlantic and Amazonian Forests and (2) the Northern uplift of the Andes....

  12. Cultural Patterns of South Asian and Southeast Asian Americans.

    Science.gov (United States)

    Mathews, Rachel

    2000-01-01

    An overview of South Asian and Southeast Asian Americans is discussed to aid teachers in understanding behaviors exhibited by Asian students. Culture influences in the following areas are explored: family relationships, respect for age, social interaction, communication style, family expectations, humility, school situations, decision making, and…

  13. Tenancy and African American Marriage in the Postbellum South.

    Science.gov (United States)

    Bloome, Deirdre; Muller, Christopher

    2015-10-01

    The pervasiveness of tenancy in the postbellum South had countervailing effects on marriage between African Americans. Tenancy placed severe constraints on African American women's ability to find independent agricultural work. Freedwomen confronted not only planters' reluctance to contract directly with women but also whites' refusal to sell land to African Americans. Marriage consequently became one of African American women's few viable routes into the agricultural labor market. We find that the more counties relied on tenant farming, the more common was marriage among their youngest and oldest African American residents. However, many freedwomen resented their subordinate status within tenant marriages. Thus, we find that tenancy contributed to union dissolution as well as union formation among freedpeople. Microdata tracing individuals' marital transitions are consistent with these county-level results.

  14. South American Field Experience: An Initiative in International Education. The Implementation Journal for the South American Field Experience.

    Science.gov (United States)

    Martin, William J.

    A description is provided of Williamsport Area Community College's (WACC's) South American Field Experience program, a travel/study program for faculty and staff designed to provide a variety of learning experiences through a three week trip to Peru, Chile, Argentina, and Brazil. Chapter I presents an overview of the development of the project,…

  15. Can north american fish passage tools work for South american migratory fishes?

    Directory of Open Access Journals (Sweden)

    Claudio Rafael Mariano Baigún

    Full Text Available In North America, the Numerical Fish Surrogate (NFS is used to design fish bypass systems for emigrating juvenile salmon as they migrate from hatchery outfalls and rearing habitats to adult habitat in the oceans. The NFS is constructed of three linked modules: 1 a computational fluid dynamics model describes the complex flow fields upstream of dams at a scale sufficiently resolved to analyze, understand and forecast fish movement, 2 a particle tracking model interpolates hydraulic information from the fixed nodes of the computational fluid model mesh to multiple locations relevant to migrating fish, and 3 a behavior model simulates the cognition and behavior of individual fish in response to the fluid dynamics predicted by the computational fluid dynamics model. These three modules together create a virtual reality where virtual fish exhibit realistic dam approach behaviors and can be counted at dam exits in ways similar to the real world. Once calibrated and validated with measured fish movement and passage data, the NFS can accurately predict fish passage proportions with sufficient precision to allow engineers to select one optimum alternative from among many competing structural or operational bypass alternatives. Although South American fish species are different from North American species, it is likely that the basic computational architecture and numerical methods of the NFS can be used for fish conservation in South America. Consequently, the extensive investment made in the creation of the NFS need not be duplicated in South America. However, its use in South America will require that the behavioral response of the continent's unique fishes to hydrodynamic cues must be described, codified and tested before the NFS can be used to conserve fishes by helping design efficient South American bypass systems. To this end, we identify studies that could be used to describe the movement behavior of South American fishes of sufficient detail

  16. Phylogenetic reconstruction of South American felids defined by protein electrophoresis.

    Science.gov (United States)

    Slattery, J P; Johnson, W E; Goldman, D; O'Brien, S J

    1994-09-01

    Phylogenetic associations among six closely related South American felid species were defined by changes in protein-encoding gene loci. We analyzed proteins isolated from skin fibroblasts using two-dimensional electrophoresis and allozymes extracted from blood cells. Genotypes were determined for multiple individuals of ocelot, margay, tigrina, Geoffroy's cat, kodkod, and pampas cat at 548 loci resolved by two-dimensional electrophoresis and 44 allozyme loci. Phenograms were constructed using the methods of Fitch-Margoliash and neighbor-joining on a matrix of Nei's unbiased genetic distances for all pairs of species. Results of a relative-rate test indicate changes in two-dimensional electrophoresis data are constant among all South American felids with respect to a hyena outgroup. Allelic frequencies were transformed to discrete character states for maximum parsimony analysis. Phylogenetic reconstruction indicates a major split occurred approximately 5-6 million years ago, leading to three groups within the ocelot lineage. The earliest divergence led to Leopardus tigrina, followed by a split between an ancestor of an unresolved trichotomy of three species (Oncifelis guigna, O. geoffroyi, and Lynchailuris colocolo) and a recent common ancestor of Leopardus pardalis and L. wiedii. The results suggest that modern South American felids are monophyletic and evolved rapidly after the formation of the Panama land bridge between North and South America.

  17. Insight into American tourists’ experiences with weather in South Africa

    Directory of Open Access Journals (Sweden)

    Giddy Julia K.

    2017-12-01

    Full Text Available Weather and climate are often important factors determining the success of a tourism destination and resultant satisfaction among tourists. This is particularly true for South Africa due the predominance of outdoor tourist attractions. Increasing numbers of international tourists have visited South Africa since the fall of apartheid, particularly those from the United States (U.S., which is an important market for South African tourism. Therefore, this paper seeks to examine a sample of American tourists’ experience with day-to-day weather and climatic conditions in South Africa. The results show that although respondents did not feel that climatic conditions were an important factor in motivations to visit the country, the day-to-day weather did often impact the enjoyment of their visit. Most notably, weather controlled their ability to participate in outdoor activities. In correlating accounts of unpleasant weather conditions with the meteorological records, a close association emerged, particularly for excessively high temperatures. This indicates that the experiences of American tourists are an accurate indication of climatic unsuitability for tourism, which poses threats to the South African outdoor tourism sector.

  18. Aldehyde dehydrogenase polymorphism in North American, South American, and Mexican Indian populations.

    Science.gov (United States)

    Goedde, H W; Agarwal, D P; Harada, S; Rothhammer, F; Whittaker, J O; Lisker, R

    1986-01-01

    While about 40% of the South American Indian populations (Atacameños, Mapuche, Shuara) were found to be deficient in aldehyde dehydrogenase isozyme I (ALDH2 or E2), preliminary investigations showed very low incidence of isozyme deficiency among North American natives (Sioux, Navajo) and Mexican Indians (mestizo). Possible implications of such trait differences on cross-cultural behavioral response to alcohol drinking are discussed. PMID:3953578

  19. 2009 South American benchmarking study: natural gas transportation companies

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Nathalie [Gas TransBoliviano S.A. (Bolivia); Walter, Juliana S. [TRANSPETRO, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In the current business environment large corporations are constantly seeking to adapt their strategies. Benchmarking is an important tool for continuous improvement and decision-making. Benchmarking is a methodology that determines which aspects are the most important to be improved upon, and it proposes establishing a competitive parameter in an analysis of the best practices and processes, applying continuous improvement driven by the best organizations in their class. At the beginning of 2008, GTB (Gas TransBoliviano S.A.) contacted several South American gas transportation companies to carry out a regional benchmarking study in 2009. In this study, the key performance indicators of the South American companies, whose reality is similar, for example, in terms of prices, availability of labor, and community relations, will be compared. Within this context, a comparative study of the results, the comparative evaluation among natural gas transportation companies, is becoming an essential management instrument to help with decision-making. (author)

  20. Electricity consumption and economic growth in seven South American countries

    International Nuclear Information System (INIS)

    Yoo, Seung-Hoon; Kwak, So-Yoon

    2010-01-01

    This paper attempts to investigate the causal relationship between electricity consumption and economic growth among seven South American countries, namely Argentina, Brazil, Chile, Columbia, Ecuador, Peru, and Venezuela using widely accepted time-series techniques for the period 1975-2006. The results indicate that the causal nexus between electricity consumption and economic growth varies across countries. There is a unidirectional, short-run causality from electricity consumption to real GDP for Argentina, Brazil, Chile, Columbia, and Ecuador. This means that an increase in electricity consumption directly affects economic growth in those countries. In Venezuela, there is a bidirectional causality between electricity consumption and economic growth. This implies that an increase in electricity consumption directly affects economic growth and that economic growth also stimulates further electricity consumption in that country. However, no causal relationships exist in Peru. The documented evidence from seven South American countries can provide useful information for each government with regard to energy and growth policy.

  1. Phylogenetic reconstruction of South American felids defined by protein electrophoresis

    OpenAIRE

    Pecon Slattery, J.; Johnson, W. E.; Goldman, D.; O'Brien, S. J.

    1994-01-01

    Phylogenetic associations among six closely related South American felid species were defined by changes in protein-encoding gene loci. We analyzed proteins isolated from skin fibroblasts using two-dimensional electrophoresis and allozymes extracted from blood cells. Genotypes were determined for multiple individuals of ocelot, margay, tigrina, Geoffroy's cat, kodkod, and pampas cat at 548 loci resolved by two-dimensional electrophoresis and 44 allozyme loci. Phenograms were constructed using...

  2. New views on American colonization: critical tests from South America

    Directory of Open Access Journals (Sweden)

    O'Rourke, Dennis

    2007-01-01

    Full Text Available The traditional view of colonization of the Americas as a migration across Beringia and subsequent dispersal southward following the last glacial maximum is being increasingly questioned. In North America, archaeological links to Siberia are tenuous and genetic data are more consistent with an earlier entry of people into the Americas, from Central rather than Northeast Siberia. An entry of populations into the Americas prior to the last glacial maximum forces a reconsideration not only of timing, but also geographic points of entry and speed of dispersal, based on ecological theory. A number of emerging alternative hypotheses on the colonization of the Americas predict early entry and dispersal of people into South America - earlier than, or coeval with, initial dispersal in North America. The study of genetic, morphological, and archaeological variation across South America is critical to testing these new, alternative hypotheses of Native American origins. I will review the evidence for emerging, alternative views of American Colonization, and suggest ways in which data from South American populations and prehistory will be crucial in testing them.

  3. The Analysis of Polyploid Genetic Data

    NARCIS (Netherlands)

    Meirmans, P.G.; Liu, S.; van Tienderen, P.H.

    2018-01-01

    Though polyploidy is an important aspect of the evolutionary genetics of both plants and animals, the development of population genetic theory of polyploids has seriously lagged behind that of diploids. This is unfortunate since the analysis of polyploid genetic data—and the interpretation of the

  4. First South American Agathis (Araucariaceae), Eocene of Patagonia.

    Science.gov (United States)

    Wilf, Peter; Escapa, Ignacio H; Cúneo, N Rubén; Kooyman, Robert M; Johnson, Kirk R; Iglesias, Ari

    2014-01-01

    Agathis is an iconic genus of large, ecologically important, and economically valuable conifers that range over lowland to upper montane rainforests from New Zealand to Sumatra. Exploitation of its timber and copal has greatly reduced the genus's numbers. The early fossil record of Agathis comes entirely from Australia, often presumed to be its area of origin. Agathis has no previous record from South America. We describe abundant macrofossils of Agathis vegetative and reproductive organs, from early and middle Eocene rainforest paleofloras of Patagonia, Argentina. The leaves were formerly assigned to the New World cycad genus Zamia. Agathis zamunerae sp. nov. is the first South American occurrence and the most complete representation of Agathis in the fossil record. Its morphological features are fully consistent with the living genus. The most similar living species is A. lenticula, endemic to lower montane rainforests of northern Borneo. Agathis zamunerae sp. nov. demonstrates the presence of modern-aspect Agathis by 52.2 mya and vastly increases the early range and possible areas of origin of the genus. The revision from Zamia breaks another link between the Eocene and living floras of South America. Agathis was a dominant, keystone element of the Patagonian Eocene floras, alongside numerous other plant taxa that still associate with it in Australasia and Southeast Asia. Agathis extinction in South America was an integral part of the transformation of Patagonian biomes over millions of years, but the living species are disappearing from their ranges at a far greater rate.

  5. Intestinal helminths in lowland South American Indians: some evolutionary interpretations.

    Science.gov (United States)

    Confalonieri, U; Ferreira, L F; Araújo, A

    1991-12-01

    Data on intestinal parasite infections for South American Indians in prehistoric times as revealed by coprolite analysis are being used to support transoceanic migration routes from the Old World to the New World. These same findings on modern semi-isolated aborigines, considered persisting prehistoric patterns, are also of great importance as indicators of pre-Columbian peopling of South America. This is the case for the Lengua Indians from Paraguay, studied in the 1920s, and the Yanomami and the Salumã from Brazil, studied in the 1980s. The intestinal parasitic profile of these groups can be empirically associated with culture change, but no clear correlations with the population biology of their hosts can be made at present because of scarcity of data.

  6. The impact of the subtropical South Atlantic SST on South American precipitation

    Directory of Open Access Journals (Sweden)

    A. S. Taschetto

    2008-11-01

    Full Text Available The Community Climate Model (CCM3 from the National Center for Atmospheric Research (NCAR is used to investigate the effect of the South Atlantic sea surface temperature (SST anomalies on interannual to decadal variability of South American precipitation. Two ensembles composed of multidecadal simulations forced with monthly SST data from the Hadley Centre for the period 1949 to 2001 are analysed.

    A statistical treatment based on signal-to-noise ratio and Empirical Orthogonal Functions (EOF is applied to the ensembles in order to reduce the internal variability among the integrations. The ensemble treatment shows a spatial and temporal dependence of reproducibility. High degree of reproducibility is found in the tropics while the extratropics is apparently less reproducible. Austral autumn (MAM and spring (SON precipitation appears to be more reproducible over the South America-South Atlantic region than the summer (DJF and winter (JJA rainfall. While the Inter-tropical Convergence Zone (ITCZ region is dominated by external variance, the South Atlantic Convergence Zone (SACZ over South America is predominantly determined by internal variance, which makes it a difficult phenomenon to predict. Alternatively, the SACZ over western South Atlantic appears to be more sensitive to the subtropical SST anomalies than over the continent.

    An attempt is made to separate the atmospheric response forced by the South Atlantic SST anomalies from that associated with the El Niño – Southern Oscillation (ENSO. Results show that both the South Atlantic and Pacific SSTs modulate the intensity and position of the SACZ during DJF. Particularly, the subtropical South Atlantic SSTs are more important than ENSO in determining the position of the SACZ over the southeast Brazilian coast during DJF. On the other hand, the ENSO signal seems to influence the intensity of the SACZ not only in DJF but especially its oceanic branch during MAM. Both local and

  7. Functional reprogramming of polyploidization in megakaryocytes.

    Science.gov (United States)

    Trakala, Marianna; Rodríguez-Acebes, Sara; Maroto, María; Symonds, Catherine E; Santamaría, David; Ortega, Sagrario; Barbacid, Mariano; Méndez, Juan; Malumbres, Marcos

    2015-01-26

    Polyploidization is a natural process that frequently accompanies differentiation; its deregulation is linked to genomic instability and cancer. Despite its relevance, why cells select different polyploidization mechanisms is unknown. Here we report a systematic genetic analysis of endomitosis, a process in which megakaryocytes become polyploid by entering mitosis but aborting anaphase. Whereas ablation of the APC/C cofactor Cdc20 results in mitotic arrest and severe thrombocytopenia, lack of the kinases Aurora-B, Cdk1, or Cdk2 does not affect megakaryocyte polyploidization or platelet levels. Ablation of Cdk1 forces a switch to endocycles without mitosis, whereas polyploidization in the absence of Cdk1 and Cdk2 occurs in the presence of aberrant re-replication events. Importantly, ablation of these kinases rescues the defects in Cdc20 null megakaryocytes. These findings suggest that endomitosis can be functionally replaced by alternative polyploidization mechanisms in vivo and provide the cellular basis for therapeutic approaches aimed to discriminate mitotic and polyploid cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Y-chromosome lineages in native South American population.

    Science.gov (United States)

    Blanco-Verea, A; Jaime, J C; Brión, M; Carracedo, A

    2010-04-01

    The present work tries to investigate the population structure and variation of the Amerindian indigenous populations living in Argentina. A total of 134 individuals from three ethnic groups (Kolla, Mapuche and Diaguitas) living in four different regions were collected and analysed for 26 Y-SNPs and 11 Y-STRs. Intra-population variability was analysed, looking for population substructure and neighbour populations were considered for genetic comparative analysis, in order to estimate the contribution of the Amerindian and the European pool, to the current population. We observe a high frequency of R1b1 and Q1a3a* Y-chromosome haplogroups, in the ethnic groups Mapuche, Diaguita and Kolla, characteristic of European and Native American populations, respectively. When we compare our native Argentinean population with other from the South America we also observe that frequency values for Amerindian lineages are relatively lower in our population. These results show a clear Amerindian genetic component but we observe a predominant European influence too, suggesting that typically European male lineages have given rise to the displacement of genuinely Amerindian male lineages in our South American population. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  9. South American Guidelines for Cardiovascular Disease Prevention and Rehabilitation

    Directory of Open Access Journals (Sweden)

    AH Herdy

    2014-08-01

    Full Text Available In this document, the Inter-American Committee of Cardiovascular Prevention and Rehabilitation, together with the South American Society of Cardiology, aimed to formulate strategies, measures, and actions for cardiovascular disease prevention and rehabilitation (CVDPR. In the context of the implementation of a regional and national health policy in Latin American countries, the goal is to promote cardiovascular health and thereby decrease morbidity and mortality. The study group on Cardiopulmonary and Metabolic Rehabilitation from the Department of Exercise, Ergometry, and Cardiovascular Rehabilitation of the Brazilian Society of Cardiology has created a committee of experts to review the Portuguese version of the guideline and adapt it to the national reality. The mission of this document is to help health professionals to adopt effective measures of CVDPR in the routine clinical practice. The publication of this document and its broad implementation will contribute to the goal of the World Health Organization (WHO, which is the reduction of worldwide cardiovascular mortality by 25% until 2025. The study group's priorities are the following: • Emphasize the important role of CVDPR as an instrument of secondary prevention with significant impact on cardiovascular morbidity and mortality; • Join efforts for the knowledge on CVDPR, its dissemination, and adoption in most cardiovascular centers and institutes in South America, prioritizing the adoption of cardiovascular prevention methods that are comprehensive, practical, simple and which have a good cost/benefit ratio; • Improve the education of health professionals and patients with education programs on the importance of CVDPR services, which are directly targeted at the health system, clinical staff, patients, and community leaders, with the aim of decreasing the barriers to CVDPR implementation.

  10. Gender, Family, and Community Correlates of Mental Health in South Asian Americans

    OpenAIRE

    Masood, Nausheen; Okazaki, Sumie; Takeuchi, David T.

    2009-01-01

    Nationally representative data from the National Latino and Asian American Study (Alegría et al., 2004) was used to examine both disorder prevalence rates and correlates of distress for the South Asian American subgroup (n = 164). South Asian Americans generally appeared to have lower or comparable rates of lifetime and 12-month mood and anxiety disorders when compared with the overall Asian American sample. A multiple-regression model fitted to predict recent psychological distress, with 12-...

  11. Involvement of Receptor Activator of Nuclear Factor-κB Ligand (RANKL)-induced Incomplete Cytokinesis in the Polyploidization of Osteoclasts.

    Science.gov (United States)

    Takegahara, Noriko; Kim, Hyunsoo; Mizuno, Hiroki; Sakaue-Sawano, Asako; Miyawaki, Atsushi; Tomura, Michio; Kanagawa, Osami; Ishii, Masaru; Choi, Yongwon

    2016-02-12

    Osteoclasts are specialized polyploid cells that resorb bone. Upon stimulation with receptor activator of nuclear factor-κB ligand (RANKL), myeloid precursors commit to becoming polyploid, largely via cell fusion. Polyploidization of osteoclasts is necessary for their bone-resorbing activity, but the mechanisms by which polyploidization is controlled remain to be determined. Here, we demonstrated that in addition to cell fusion, incomplete cytokinesis also plays a role in osteoclast polyploidization. In in vitro cultured osteoclasts derived from mice expressing the fluorescent ubiquitin-based cell cycle indicator (Fucci), RANKL induced polyploidy by incomplete cytokinesis as well as cell fusion. Polyploid cells generated by incomplete cytokinesis had the potential to subsequently undergo cell fusion. Nuclear polyploidy was also observed in osteoclasts in vivo, suggesting the involvement of incomplete cytokinesis in physiological polyploidization. Furthermore, RANKL-induced incomplete cytokinesis was reduced by inhibition of Akt, resulting in impaired multinucleated osteoclast formation. Taken together, these results reveal that RANKL-induced incomplete cytokinesis contributes to polyploidization of osteoclasts via Akt activation. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. The Analysis of Polyploid Genetic Data.

    Science.gov (United States)

    Meirmans, Patrick G; Liu, Shenglin; van Tienderen, Peter H

    2018-03-16

    Though polyploidy is an important aspect of the evolutionary genetics of both plants and animals, the development of population genetic theory of polyploids has seriously lagged behind that of diploids. This is unfortunate since the analysis of polyploid genetic data-and the interpretation of the results-requires even more scrutiny than with diploid data. This is because of several polyploidy-specific complications in segregation and genotyping such as tetrasomy, double reduction, and missing dosage information. Here, we review the theoretical and statistical aspects of the population genetics of polyploids. We discuss several widely used types of inferences, including genetic diversity, Hardy-Weinberg equilibrium, population differentiation, genetic distance, and detecting population structure. For each, we point out how the statistical approach, expected result, and interpretation differ between different ploidy levels. We also discuss for each type of inference what biases may arise from the polyploid-specific complications and how these biases can be overcome. From our overview, it is clear that the statistical toolbox that is available for the analysis of genetic data is flexible and still expanding. Modern sequencing techniques will soon be able to overcome some of the current limitations to the analysis of polyploid data, though the techniques are lagging behind those available for diploids. Furthermore, the availability of more data may aggravate the biases that can arise, and increase the risk of false inferences. Therefore, simulations such as we used throughout this review are an important tool to verify the results of analyses of polyploid genetic data.

  13. Desi Women on the Forty Acres: Exploring Intergenerational Issues and Identity Development of South Asian American College Students

    Science.gov (United States)

    Ruzicka, Smita Sundaresan

    2011-01-01

    South Asian Americans are one of the fastest growing sub-groups within the Asian American population in the United States today. Between 1960 and 1990, the South Asian American population witnessed an increase of approximately 900% (Leonard, 1997). This increase in population also corresponds with the increase in South Asian American students…

  14. AIRSAR South American deployment: Operation plan, version 3.0

    Science.gov (United States)

    Kobrick, M.

    1993-01-01

    The United States National Aeronautics and Space Administration (NASA) and the Brazilian Commission for Space Activities (COBAE) are undertaking a joint experiment involving NASA's DC-8 research aircraft and the Airborne Synthetic Aperture Radar (AIRSAR) system during late May and June 1993. The research areas motivating these activities are: (1) fundamental research in the role of soils, vegetation, and hydrology in the global carbon cycle; and (2) in cooperation with South American scientists, airborne remote sensing research for the upcoming NASA Spaceborne Imaging Radar (SIR)-C/X-SAR flights on the Space Shuttle. A flight schedule and plans for the deployment that were developed are included. Maps of the site locations and schematic indications of flight routes and dates, plots showing swath locations derived from the flight requests and generated by flight planning software, and, most importantly, a calendar showing which sites will be imaged each day are included.

  15. Prosopis pod production - comparison of North American, South American, Hawaiian, and African germplasm in young plantations

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.; Clark, P.R.; Osborn, J.F.; Cannell, G.H.

    Prosopis pod production was compared in 3 field trials in southern California, i.e., a typical orchard planting, an irrigation trial, and a heat/drought stress trial. Thirteen species representing North American, South American, Hawaiian, and African germplasm were evaluated. Hawaiian and African accessions were eliminated from the irrigation trial by a minus 5/sup 0/C temperature. The most productive pod producers were P. velutina accessions from southern Arizona. In the fifth season, 5 trees of the most productive accession, i.e. P. velutina 32 had a mean pod production of 7.2 kg/tree with a range of 3.2-12.2 kg/tree. P. chilensis and P. alba trees of the same age were much larger but had less pod production. Pod production estimates of 3000-4000 kg/ha were obtained in the dry irrigation treatment by P. velutina 20 which received 370 mm rainfall in the year preceding harvest.

  16. Progenitor-derivative relationships of Hordeum polyploids (Poaceae, Triticeae inferred from sequences of TOPO6, a nuclear low-copy gene region.

    Directory of Open Access Journals (Sweden)

    Jonathan Brassac

    Full Text Available Polyploidization is a major mechanism of speciation in plants. Within the barley genus Hordeum, approximately half of the taxa are polyploids. While for diploid species a good hypothesis of phylogenetic relationships exists, there is little information available for the polyploids (4×, 6× of Hordeum. Relationships among all 33 diploid and polyploid Hordeum species were analyzed with the low-copy nuclear marker region TOPO6 for 341 Hordeum individuals and eight outgroup species. PCR products were either directly sequenced or cloned and on average 12 clones per individual were included in phylogenetic analyses. In most diploid Hordeum species TOPO6 is probably a single-copy locus. Most sequences found in polyploid individuals phylogenetically cluster together with sequences derived from diploid species and thus allow the identification of parental taxa of polyploids. Four groups of sequences occurring only in polyploid taxa are interpreted as footprints of extinct diploid taxa, which contributed to allopolyploid evolution. Our analysis identifies three key species involved in the evolution of the American polyploids of the genus. (i All but one of the American tetraploids have a TOPO6 copy originating from the Central Asian diploid H. roshevitzii, the second copy clustering with different American diploid species. (ii All hexaploid species from the New World have a copy of an extinct close relative of H. californicum and (iii possess the TOPO6 sequence pattern of tetraploid H. jubatum, each with an additional copy derived from different American diploids. Tetraploid H. bulbosum is an autopolyploid, while the assumed autopolyploid H. brevisubulatum (4×, 6× was identified as allopolyploid throughout most of its distribution area. The use of a proof-reading DNA polymerase in PCR reduced the proportion of chimerical sequences in polyploids in comparison to Taq polymerase.

  17. 78 FR 50135 - CNC Development, Ltd., Exousia Advanced Materials, Inc., and South American Minerals, Inc.; Order...

    Science.gov (United States)

    2013-08-16

    ... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] CNC Development, Ltd., Exousia Advanced Materials, Inc., and South American Minerals, Inc.; Order of Suspension of Trading August 14, 2013. It... securities of South American Minerals, Inc. because it has not filed any periodic reports since it filed a...

  18. Exploring Hybrid Identities: South Asian American Women Pursue a Career in Teaching

    Science.gov (United States)

    Shah, Amita Roy

    2013-01-01

    This study explores how second-generation South Asian American women negotiated their hybrid identities to pursue a career in teaching. Many South Asian Americans have not pursued a career in teaching because of various external and internal factors that have influenced their sense of identity, academic achievement, and professional career path…

  19. The Impact of China on South American Political and Economic Development

    DEFF Research Database (Denmark)

    Christensen, Steen Fryba

    2018-01-01

    The analysis compares three typologies of South American countries in terms of the impact of China on their political and economic development.......The analysis compares three typologies of South American countries in terms of the impact of China on their political and economic development....

  20. “Liting it up”: Popular Culture, Indo-Pak Basketball, and South Asian American Institutions

    OpenAIRE

    Stanley Ilango Thangaraj

    2010-01-01

    South Asian American participants of a co-ethnic basketball league, known as Indo-Pak Basketball, utilized urban basketball vernacular through the phrase “liting it up” to identify individuals scoring points in great numbers. The person “liting it up” becomes visible and receives recognition. Accordingly, I want to “lite up” the scholarship on South Asian America whereby situating South Asian American religious sites and cultural centers as key arenas for “Americanization” through US popula...

  1. South Asian American Perspectives on Overweight, Obesity, and the Relationship Between Weight and Health

    OpenAIRE

    Tang, Joyce W.; Mason, Maryann; Kushner, Robert F.; Tirodkar, Manasi A.; Khurana, Neerja; Kandula, Namratha R.

    2012-01-01

    Introduction Compared with other racial groups, South Asian adults develop type 2 diabetes and cardiovascular disease at a lower body mass index (BMI). Perceptions of weight and the effect of weight on health can influence weight-loss attempts but are not well described in this population. The objective of this study was to examine perceptions of weight appropriateness and the effect of weight on health among South Asian Americans. Methods We recruited 75 South Asian American adults from a si...

  2. Atypical E2f functions are critical for pancreas polyploidization

    NARCIS (Netherlands)

    Matondo, Ramadhan B; Moreno, Eva; Toussaint, Mathilda J M; Tooten, Peter C J; van Essen, Saskia C; van Liere, Elsbeth A; Youssef, Sameh A; Bongiovanni, Laura; de Bruin, Alain

    2018-01-01

    The presence of polyploid cells in the endocrine and exocrine pancreas has been reported for four decades. In rodents, pancreatic polyploidization is initiated after weaning and the number of polyploid cells increases with age. Surprisingly the molecular regulators and biological functions of

  3. Prospects for the development of the South American methanol industry

    International Nuclear Information System (INIS)

    Motilal, R.

    1995-01-01

    The industry entered 1994 with positive market conditions and became increasingly robust as consumers mobilized for the anticipated needs of the second phase of the Clean Air Act. These conditions were reinforced by structural changes taking place in the industry the prime result being the emergence of a single marketer as the dominant force in world trade. In 1995 however, the drawdown of stockpiles of MTBE and methanol accumulated earlier, created conditions of excess as the industry continued to run at nearly full capacity and as opt outs from the reformulated gasoline program dampened the rate of MTBE consumption. The historical forces that attend market cycles on its way up by exerting stickiness upward also contrived to accelerate prices on their way down. Market pricing in the methanol industry, as in other commodities is set largely by the incremental molecules entering the market place. Accordingly, the terms and conditions of the transactions covering traded volumes represent a major influence on market pricing. The major portion of traded volumes are sourced from offshore locations where the domestic market is small in comparison to the production capacities. The South American region is one such strategic offshore location on which increasing emphasis must be placed, if any realistic prognosis of the future direction of the industry is to be made. It is in this context, that this paper attempts to review the underlying factors which led to the rapid growth of the major methanol producing countries in South America and to emphasize the potential for continued development of this region and its strategic importance to the global methanol industry both as a major source of production and as a significant force in the world methanol trade

  4. Premature mortality patterns among American Indians in South Dakota, 2000-2010.

    Science.gov (United States)

    Christensen, Mathew; Kightlinger, Lon

    2013-05-01

    American Indians in South Dakota have the highest mortality rates in the nation compared to other racial and ethnic groups and American Indians in other states. Cause-related and age-specific mortality patterns among American Indians in South Dakota are identified to guide prevention planning and policy efforts designed to reduce mortality within this population, in both South Dakota and other parts of the U.S. Death certificate data from South Dakota (2000-2010), on 5738 American Indians and 70,580 whites, were used to calculate age-specific mortality rates and rate ratios. These values were examined in order to identify patterns among the leading causes of death. Analyses were completed in 2011 and 2012. Within the South Dakota population, 70% of American Indians died before reaching age 70 years, compared to 25% of whites. Fatal injuries and chronic diseases were the leading causes of premature mortality. Nine leading causes of death showed consistent patterns of mortality disparity between American Indians and whites, with American Indians having significantly higher rates of mortality at lower ages. Premature mortality among American Indians in South Dakota is a serious public health problem. Unified efforts at the federal, tribal, state, and local levels are needed to reduce premature death within this population. Copyright © 2013 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  5. Resveratrol, phenolic antioxidants, and saccharides in South American red wines

    Directory of Open Access Journals (Sweden)

    Osorio-Macías DE

    2018-01-01

    Full Text Available Daniel E Osorio-Macías,1,2 Pamela Vásquez,3 Cristhian Carrasco,3 Bjorn Bergenstahl,1 J Mauricio Peñarrieta2 1Department of Food Technology, Faculty of Engineering LTH, Lund University, Lund, Sweden; 2School of Chemistry, Faculty of Pure and Natural Sciences, 3Institute of Research and Development of Chemical Processes, Department of Chemical Engineering, Faculty of Engineering, Universidad Mayor de San Andrés (UMSA, La Paz, Bolivia Abstract: Wine is an important beverage with a long tradition, and its moderate consumption may be considered beneficial for human health. Although there are many studies regarding phenolic compounds in wines, there is a lack of information about antioxidants and phenolic content in South American wines. In this study, 35 South American red wines from four different countries, vintages 2004–2013, purchased at retail stores in La Paz, Bolivia, were studied. Resveratrol content, total antioxidant capacity (TAC by the 2,2′-azino-bis(3-ethylbenzotiazoline-6-sulfonic acid (ABTS and ferric-reducing antioxidant power (FRAP methods, total phenolic content (TPH, total flavonoids (TF, and main saccharides were assessed using the well-established spectrophotometric and high-performance liquid chromatography methods. The results ranged from 4 to 24 mmol/L for TAC determined by ABTS method and 14 to 43 mmol/L for TAC determined by FRAP method, 1600 to 3500 mg gallic acid equivalents/L for TPH, and 2 to 6 mmol catechin equivalents /L for TF. The resveratrol content ranged from 0.1 to 8 mg/L. Saccharides, glucose, and fructose content ranged from 0.4 to 10 g/L, 1.4 to 8.6 g/L, and 0.2 to 12 g/L, respectively. There was a high correlation among the different methods. The results showed that some wines growing at high altitude (>1500 meters above the sea level have higher amounts of TAC and phenolic content, including resveratrol, while non-varietal wines showed the lowest values. It was also observed that the saccharose

  6. On the use of the South-American neutron monitors

    Energy Technology Data Exchange (ETDEWEB)

    Cordaro, E. G. [Santiago de Chile Univ., Santiago de Chile (Chile). Facultad de Ciencias Fisicas y Matematicas, Dept. de Fisica, Lewis Research Center; Storini, M. [Consiglio Nazionale delle Ricerche, Istituto di Fisica dello Spazio Interplanetario, Rome (Italy); Rome Univ. Tre, Rome (Italy). Dipt. di Fisica, Raggi Cosmici

    2001-10-01

    Cosmic ray scientific community deserves special attention to the Chacaltaya site for its over 5 km altitude. In this site, a neutron monitor of the IGY type operated from 1960 to 1969, and the one of the NM-64 type since 1966 (16.31{sup 0}S, 291.85{sup 0}E, height: about 5200 m a.s.l.). It was discussed the relevance of such kind of detector when it is integrated with the other South-American neutron monitors: a) LARC (62.20{sup 0}S, 301.04{sup 0}E, height: 40 m a.s.l., King George Island, Antarctica; operating since 1991); b) Los Cerrillos (33.45{sup 0}S, 289.40{sup 0}E, height: 570 m a. s. l., Santiago, Chile; to be installed in the near future); c) Huancayo (12.03{sup 0}S, 284.67{sup 0}E, height: 3400 m a.s.l., Huancayo, Peru; hoping to recover its acquired data).

  7. Soil Quality Impacts of Current South American Agricultural Practices

    Directory of Open Access Journals (Sweden)

    Ana B. Wingeyer

    2015-02-01

    Full Text Available Increasing global demand for oil seeds and cereals during the past 50 years has caused an expansion in the cultivated areas and resulted in major soil management and crop production changes throughout Bolivia, Paraguay, Uruguay, Argentina and southern Brazil. Unprecedented adoption of no-tillage as well as improved soil fertility and plant genetics have increased yields, but the use of purchased inputs, monocropping i.e., continuous soybean (Glycine max (L. Merr., and marginal land cultivation have also increased. These changes have significantly altered the global food and feed supply role of these countries, but they have also resulted in various levels of soil degradation through wind and water erosion, soil compaction, soil organic matter (SOM depletion, and nutrient losses. Sustainability is dependent upon local interactions between soil, climate, landscape characteristics, and production systems. This review examines the region’s current soil and crop conditions and summarizes several research studies designed to reduce or prevent soil degradation. Although the region has both environmental and soil resources that can sustain current agricultural production levels, increasing population, greater urbanization, and more available income will continue to increase the pressure on South American croplands. A better understanding of regional soil differences and quantifying potential consequences of current production practices on various soil resources is needed to ensure that scientific, educational, and regulatory programs result in land management recommendations that support intensification of agriculture without additional soil degradation or other unintended environmental consequences.

  8. South Asian high and Asian-Pacific-American climate teleconnection

    Science.gov (United States)

    Zhang, Peiqun; Song, Yang; Kousky, Vernon E.

    2005-11-01

    Growing evidence indicates that the Asian monsoon plays an important role in affecting the weather and climate outside of Asia. However, this active role of the monsoon has not been demonstrated as thoroughly as has the variability of the monsoon caused by various impacting factors such as sea surface temperature and land surface. This study investigates the relationship between the Asian monsoon and the climate anomalies in the Asian-Pacific-American (APA) sector. A hypothesis is tested that the variability of the upper-tropospheric South Asian high (SAH), which is closely associated with the overall heating of the large-scale Asian monsoon, is linked to changes in the subtropical western Pacific high (SWPH), the mid-Pacific trough, and the Mexican high. The changes in these circulation systems cause variability in surface temperature and precipitation in the APA region. A stronger SAH is accompanied by a stronger and more extensive SWPH. The enlargement of the SWPH weakens the mid-Pacific trough. As a result, the southern portion of the Mexican high becomes stronger. These changes are associated with changes in atmospheric teleconnections, precipitation, and surface temperature throughout the APA region. When the SAH is stronger, precipitation increases in southern Asia, decreases over the Pacific Ocean, and increases over the Central America. Precipitation also increases over Australia and central Africa and decreases in the Mediterranean region. While the signals in surface temperature are weak over the tropical land portion, they are apparent in the mid latitudes and over the eastern Pacific Ocean.

  9. Recurrent evolution of melanism in South American felids.

    Directory of Open Access Journals (Sweden)

    Alexsandra Schneider

    2015-02-01

    Full Text Available Morphological variation in natural populations is a genomic test bed for studying the interface between molecular evolution and population genetics, but some of the most interesting questions involve non-model organisms that lack well annotated reference genomes. Many felid species exhibit polymorphism for melanism but the relative roles played by genetic drift, natural selection, and interspecies hybridization remain uncertain. We identify mutations of Agouti signaling protein (ASIP or the Melanocortin 1 receptor (MC1R as independent causes of melanism in three closely related South American species: the pampas cat (Leopardus colocolo, the kodkod (Leopardus guigna, and Geoffroy's cat (Leopardus geoffroyi. To assess population level variation in the regions surrounding the causative mutations we apply genomic resources from the domestic cat to carry out clone-based capture and targeted resequencing of 299 kb and 251 kb segments that contain ASIP and MC1R, respectively, from 54 individuals (13-21 per species, achieving enrichment of ~500-2500-fold and ~150x coverage. Our analysis points to unique evolutionary histories for each of the three species, with a strong selective sweep in the pampas cat, a distinctive but short melanism-specific haplotype in the Geoffroy's cat, and reduced nucleotide diversity for both ancestral and melanism-bearing chromosomes in the kodkod. These results reveal an important role for natural selection in a trait of longstanding interest to ecologists, geneticists, and the lay community, and provide a platform for comparative studies of morphological variation in other natural populations.

  10. Recurrent evolution of melanism in South American felids.

    Science.gov (United States)

    Schneider, Alexsandra; Henegar, Corneliu; Day, Kenneth; Absher, Devin; Napolitano, Constanza; Silveira, Leandro; David, Victor A; O'Brien, Stephen J; Menotti-Raymond, Marilyn; Barsh, Gregory S; Eizirik, Eduardo

    2015-02-01

    Morphological variation in natural populations is a genomic test bed for studying the interface between molecular evolution and population genetics, but some of the most interesting questions involve non-model organisms that lack well annotated reference genomes. Many felid species exhibit polymorphism for melanism but the relative roles played by genetic drift, natural selection, and interspecies hybridization remain uncertain. We identify mutations of Agouti signaling protein (ASIP) or the Melanocortin 1 receptor (MC1R) as independent causes of melanism in three closely related South American species: the pampas cat (Leopardus colocolo), the kodkod (Leopardus guigna), and Geoffroy's cat (Leopardus geoffroyi). To assess population level variation in the regions surrounding the causative mutations we apply genomic resources from the domestic cat to carry out clone-based capture and targeted resequencing of 299 kb and 251 kb segments that contain ASIP and MC1R, respectively, from 54 individuals (13-21 per species), achieving enrichment of ~500-2500-fold and ~150x coverage. Our analysis points to unique evolutionary histories for each of the three species, with a strong selective sweep in the pampas cat, a distinctive but short melanism-specific haplotype in the Geoffroy's cat, and reduced nucleotide diversity for both ancestral and melanism-bearing chromosomes in the kodkod. These results reveal an important role for natural selection in a trait of longstanding interest to ecologists, geneticists, and the lay community, and provide a platform for comparative studies of morphological variation in other natural populations.

  11. Semen preservation and artificial insemination in domesticated South American camelids.

    Science.gov (United States)

    Bravo, P Walter; Alarcon, V; Baca, L; Cuba, Y; Ordoñez, C; Salinas, J; Tito, F

    2013-01-10

    Semen preservation and artificial insemination in South American camelids are reviewed giving emphasis to work done in Peru and by the authors. Reports on semen evaluation and the preservation process indicate that semen of alpacas and llamas can be manipulated by making it liquid first. Collagenase appears to be the best enzyme to eliminate viscosity. Tris buffer solution maintains a higher motility than egg-yolk citrate, phosphate buffered saline (PBS), Triladyl, and Merck-I extenders. Cooling of semen took 1h after collected, and equilibrated with 7% glycerol presented a better motility and spermatozoa survival at 1, 7, 15 and 30days after being slowly frozen in 0.25mL plastic straws. Trials of artificial insemination with freshly diluted semen and frozen-thawed semen are encouraging and needs to be tested extensively under field conditions. Recently, fertility rates varied from 3 to 67%. Semen preservation and most important, artificial insemination appear to be a reality, and could be used to improve the genetic quality of alpacas and llamas. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Antiviral activity of some South American medicinal plants.

    Science.gov (United States)

    Abad, M J; Bermejo, P; Sanchez Palomino, S; Chiriboga, X; Carrasco, L

    1999-03-01

    Folk medicinal plants are potential sources of useful therapeutic compounds including some with antiviral activities. Extracts prepared from 10 South American medicinal plants (Baccharis trinervis, Baccharis teindalensis, Eupatorium articulatum, Eupatorium glutinosum, Tagetes pusilla, Neurolaena lobata, Conyza floribunda, Phytolacca bogotensis, Phytolacca rivinoides and Heisteria acuminata) were screened for in vitro antiviral activity against herpes simplex type I (HSV-1), vesicular stomatitis virus (VSV) and poliovirus type 1. The most potent inhibition was observed with an aqueous extract of B. trinervis, which inhibited HSV-1 replication by 100% at 50-200 micrograms/mL, without showing cytotoxic effects. Good activities were also found with the ethanol extract of H. acuminata and the aqueous extract of E. articulatum, which exhibited antiviral effects against both DNA and RNA viruses (HSV-1 and VSV, respectively) at 125-250 micrograms/mL. The aqueous extracts of T. pusilla (100-250 micrograms/mL), B. teindalensis (50-125 micrograms/mL) and E. glutinosum (50-125 micrograms/mL) also inhibited the replication of VSV, but none of the extracts tested had any effect on poliovirus replication.

  13. Decidual cell polyploidization necessitates mitochondrial activity.

    Directory of Open Access Journals (Sweden)

    Xinghong Ma

    Full Text Available Cellular polyploidy has been widely reported in nature, yet its developmental mechanism and function remain poorly understood. In the present study, to better define the aspects of decidual cell polyploidy, we isolated pure polyploid and non-polyploid decidual cell populations from the in vivo decidual bed. Three independent RNA pools prepared for each population were then subjected to the Affymetrix gene chip analysis for the whole mouse genome transcripts. Our data revealed up-regulation of 1015 genes and down-regulation of 1207 genes in the polyploid populations, as compared to the non-polyploid group. Comparative RT-PCR and in situ hybridization results indeed confirmed differential expressional regulation of several genes between the two populations. Based on functional enrichment analyses, up-regulated polyploidy genes appeared to implicate several functions, which primarily include cell/nuclear division, ATP binding, metabolic process, and mitochondrial activity, whereas that of down-regulated genes primarily included apoptosis and immune processes. Further analyses of genes that are related to mitochondria and bi-nucleation showed differential and regional expression within the decidual bed, consistent with the pattern of polyploidy. Consistently, studies revealed a marked induction of mitochondrial mass and ATP production in polyploid cells. The inhibition of mitochondrial activity by various pharmacological inhibitors, as well as by gene-specific targeting using siRNA-mediated technology showed a dramatic attenuation of polyploidy and bi-nucleation development during in vitro stromal cell decidualization, suggesting mitochondria play a major role in positive regulation of decidual cell polyploidization. Collectively, analyses of unique polyploidy markers and molecular signaling networks may be useful to further characterize functional aspects of decidual cell polyploidy at the site of implantation.

  14. Prosopis pod production: comparison of North American, South American, Hawaiin, and African germplasm in young plantations

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.; Clark, P.R.; Osborn, J.F.; Cannell, G.H.

    Prosopis pod production was compared in 3 field trials in southern California, i.e., a typical orchard planting, an irrigation trial, and a heat/drought stress trial. Thirteen species representing North American, South American, Hawaiian, and African germplasm were evaluated. Hawaiian and African accessions were eliminated from the irrigation trial by a minus 5/sup 0/C temperature. The most productive pod producers were P. velutina accessions from southern Arizona. In the fifth season, 5 trees of the most productive accession, i.e., P. velutina 32 had a mean pod production of 7.2 kg/tree with a range of 3.2-12.2 kg/tree. P. chilensis and P. alba trees of the same age were much larger but had less pod production. Trees in the driest irrigation treatment had the greatest pod production. Pod production estimates of 3000-4000 kg/ha were obtained in the dry irrigation treatment by P. velutina 20 which received 370 mm rainfall in the year preceding harvest. 32 references, 1 figure, 6 tables.

  15. 3. South American symposium on isotope geology. Extended abstracts

    International Nuclear Information System (INIS)

    2001-10-01

    This publication include papers in the fields on Methodology, thermochronology, and geochronology; Evolution of cratonic South America; Magmatic processes; Environmental geology, hydrogeology, isotopic stratigraphy and paleoclimatology; Economic Geology and Evolution of the Andean margin of South America

  16. War, religion, and white supremacy in comparative perspective: South Africa and the American South

    Directory of Open Access Journals (Sweden)

    R M�ller

    2004-10-01

    Full Text Available The southern states of the United States of America and South Africa share a number of analogous historical realities. One of these, which is the main subject of� this article,� is� the way in which the memory of a lost war had fused cultural mythology and religious symbolism to provide a foundation for the formation and maintenance of attitudes of white supremacy in both contexts.� This article seeks to achieve a historical� understanding of the complex interrelationship between the development of cultural identity and Protestant Christianity by� focusing on these issues in the histories of the Afrikaner and the white American Southerner in comparative perspective.�

  17. Antarctica: Arena for South American Cooperation or Conflict.

    Science.gov (United States)

    Child, Jack

    A number of converging circumstances suggest that Antarctica may be a major object of geopolitical attention in South America in the decade to come. The Malvinas/Falklands crisis focused geopolitical attention on the South Atlantic and the chain of Southern (Austral) Islands which link the southern tip of South America to the Antarctic Peninsula.…

  18. Fieldwork Methodology in South American Maritime Archaeology: A Critical Review

    Science.gov (United States)

    Argüeso, Amaru; Ciarlo, Nicolás C.

    2017-12-01

    In archaeology, data obtained from the analysis of material evidence (i.e., the archaeological record) from extensive excavations have been a significant means for the ultimate development of interpretations about human life in the past. Therefore, the methodological procedures and tools employed during fieldwork are of crucial importance due to their effect on the information likely to be recovered. In the case of maritime archaeology, the development of rigorous methods and techniques allowed for reaching outcomes as solid as those from the work performed on land. These improvements constituted one of the principal supports—if not, the most important pillar—for its acceptance as a scientific field of study. Over time, the growing diversity of sites under study (e.g., shipwrecks, ports, dockyards, and prehistoric settlements) and the underwater environments encountered made it clear that there was a need for the application of specific methodological criteria, in accordance with the particularities of the sites and of each study (e.g., the research aims and the available resources). This article presents some ideas concerning the methodologies used in South American investigations that have exhibited a strong emphasis on the analysis of historical shipwrecks (the sixteenth to twentieth centuries). Based on a state-of-the-knowledge review of these research projects, in particular where excavations were conducted, the article focuses on the details of the main strategies adopted and results achieved. The ideas proposed in this article can be useful as a starting point for future activities of surveying, recording, and excavating shipwrecks.

  19. Phylogenetic relationships of the South American Doradoidea (Ostariophysi: Siluriformes

    Directory of Open Access Journals (Sweden)

    José L. O. Birindelli

    Full Text Available A phylogenetic analysis based on 311 morphological characters is presented for most species of the Doradidae, all genera of the Auchenipteridae, and representatives of 16 other catfish families. The hypothesis that was derived from the six most parsimonious trees support the monophyly of the South American Doradoidea (Doradidae plus Auchenipteridae, as well as the monophyly of the clade Doradoidea plus the African Mochokidae. In addition, the clade with Sisoroidea plus Aspredinidae was considered sister to Doradoidea plus Mochokidae. Within the Auchenipteridae, the results support the monophyly of the Centromochlinae and Auchenipterinae. The latter is composed of Tocantinsia, and four monophyletic units, two small with Asterophysusand Liosomadoras, and Pseudotatiaand Pseudauchenipterus, respectively, and two large ones with the remaining genera. Within the Doradidae, parsimony analysis recovered Wertheimeriaas sister to Kalyptodoras, composing a clade sister to all remaining doradids, which include Franciscodorasand two monophyletic groups: Astrodoradinae (plus Acanthodorasand Agamyxis and Doradinae (new arrangement. Wertheimerinae, new subfamily, is described for Kalyptodoras and Wertheimeria. Doradinae is corroborated as monophyletic and composed of four groups, one including Centrochirand Platydoras, the other with the large-size species of doradids (except Oxydoras, another with Orinocodoras, Rhinodoras, and Rhynchodoras, and another with Oxydorasplus all the fimbriate-barbel doradids. Based on the results, the species of Opsodoras are included in Hemidoras; and Tenellus, new genus, is described to include Nemadoras trimaculatus, N. leporhinusand Nemadoras ternetzi. Due to conflicting hypotheses of the phylogenetic position of Acanthodoras, Agamyxis, and Franciscodoras, these are considered as incertae sedisin Doradidae. All suprageneric taxa of the Doradoidea are diagnosed based on synapomorphic morphological characteristics.

  20. Excerpt from The Red Land to the South: American Indian Writers and Indigenous Mexico

    Directory of Open Access Journals (Sweden)

    James H. Cox

    2013-09-01

    Full Text Available Excerpted from James H. Cox, The Red Land to the South: American Indian Writers and Indigenous Mexico (Minneapolis: University of Minnesota Press, 2012.Reprinted with permission from University of Minnesota Press.

  1. Polyploidization increases meiotic recombination frequency in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Rehmsmeier Marc

    2011-04-01

    Full Text Available Abstract Background Polyploidization is the multiplication of the whole chromosome complement and has occurred frequently in vascular plants. Maintenance of stable polyploid state over generations requires special mechanisms to control pairing and distribution of more than two homologous chromosomes during meiosis. Since a minimal number of crossover events is essential for correct chromosome segregation, we investigated whether polyploidy has an influence on the frequency of meiotic recombination. Results Using two genetically linked transgenes providing seed-specific fluorescence, we compared a high number of progeny from diploid and tetraploid Arabidopsis plants. We show that rates of meiotic recombination in reciprocal crosses of genetically identical diploid and autotetraploid Arabidopsis plants were significantly higher in tetraploids compared to diploids. Although male and female gametogenesis differ substantially in meiotic recombination frequency, both rates were equally increased in tetraploids. To investigate whether multivalent formation in autotetraploids was responsible for the increased recombination rates, we also performed corresponding experiments with allotetraploid plants showing strict bivalent pairing. We found similarly increased rates in auto- and allotetraploids, suggesting that the ploidy effect is independent of chromosome pairing configurations. Conclusions The evolutionary success of polyploid plants in nature and under domestication has been attributed to buffering of mutations and sub- and neo-functionalization of duplicated genes. Should the data described here be representative for polyploid plants, enhanced meiotic recombination, and the resulting rapid creation of genetic diversity, could have also contributed to their prevalence.

  2. Haplotype-Based Genotyping in Polyploids

    Directory of Open Access Journals (Sweden)

    Josh P. Clevenger

    2018-04-01

    Full Text Available Accurate identification of polymorphisms from sequence data is crucial to unlocking the potential of high throughput sequencing for genomics. Single nucleotide polymorphisms (SNPs are difficult to accurately identify in polyploid crops due to the duplicative nature of polyploid genomes leading to low confidence in the true alignment of short reads. Implementing a haplotype-based method in contrasting subgenome-specific sequences leads to higher accuracy of SNP identification in polyploids. To test this method, a large-scale 48K SNP array (Axiom Arachis2 was developed for Arachis hypogaea (peanut, an allotetraploid, in which 1,674 haplotype-based SNPs were included. Results of the array show that 74% of the haplotype-based SNP markers could be validated, which is considerably higher than previous methods used for peanut. The haplotype method has been implemented in a standalone program, HAPLOSWEEP, which takes as input bam files and a vcf file and identifies haplotype-based markers. Haplotype discovery can be made within single reads or span paired reads, and can leverage long read technology by targeting any length of haplotype. Haplotype-based genotyping is applicable in all allopolyploid genomes and provides confidence in marker identification and in silico-based genotyping for polyploid genomics.

  3. Anthropozoonotic Endoparasites in Free-Ranging ?Urban? South American Sea Lions (Otaria flavescens)

    OpenAIRE

    Hermosilla, Carlos; Silva, Liliana M. R.; Navarro, Mauricio; Taubert, Anja

    2016-01-01

    The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging “urban” colony of South American sea lions (Otaria flavescens) living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF) tech...

  4. Giemsa C-banding in two polyploid, South American Hordeum species, H. tetraploidum and H. lechleri, and their aneuploid hybrids with H. vulgare

    DEFF Research Database (Denmark)

    Linde-Laursen, Ib; Bothmer, R. von

    1986-01-01

    . The hybrids were stably aneuploid. Both had lost and acquired H. vulgare chromosomes. Thus, somatic elimination of chromosomes was combined with multiplication of chromosomes. The observations of stably aneuploid hybrids have implications for the exploitation of alien germplasm. The activity of non-H. vulgare...

  5. Gender, Family, and Community Correlates of Mental Health in South Asian Americans

    Science.gov (United States)

    Masood, Nausheen; Okazaki, Sumie; Takeuchi, David T.

    2014-01-01

    Nationally representative data from the National Latino and Asian American Study (Alegría et al., 2004) was used to examine both disorder prevalence rates and correlates of distress for the South Asian American subgroup (n = 164). South Asian Americans generally appeared to have lower or comparable rates of lifetime and 12-month mood and anxiety disorders when compared with the overall Asian American sample. A multiple-regression model fitted to predict recent psychological distress, with 12-month diagnosis as a covariate, found gender differences. For women, lack of extended family support was related to higher levels of distress, whereas for men, greater conflict with family culture, and a lower community social position (but higher U.S. social position) predicted higher distress scores. Findings suggest that mental health services consider a broad framework of psychological functioning for South Asian Americans that reflect their gendered, familial, and sociopolitical realities. PMID:19594255

  6. Gender, family, and community correlates of mental health in South Asian Americans.

    Science.gov (United States)

    Masood, Nausheen; Okazaki, Sumie; Takeuchi, David T

    2009-07-01

    Nationally representative data from the National Latino and Asian American Study (Alegría et al., 2004) was used to examine both disorder prevalence rates and correlates of distress for the South Asian American subgroup (n = 164). South Asian Americans generally appeared to have lower or comparable rates of lifetime and 12-month mood and anxiety disorders when compared with the overall Asian American sample. A multiple-regression model fitted to predict recent psychological distress, with 12-month diagnosis as a covariate, found gender differences. For women, lack of extended family support was related to higher levels of distress, whereas for men, greater conflict with family culture, and a lower community social position (but higher U.S. social position) predicted higher distress scores. Findings suggest that mental health services consider a broad framework of psychological functioning for South Asian Americans that reflect their gendered, familial, and sociopolitical realities.

  7. Ecogeographical Variation in Skull Shape of South-American Canids: Abiotic or Biotic Processes?

    Science.gov (United States)

    de Moura Bubadué, Jamile; Cáceres, Nilton; Dos Santos Carvalho, Renan; Meloro, Carlo

    Species morphological changes can be mutually influenced by environmental or biotic factors, such as competition. South American canids represent a quite recent radiation of taxa that evolved forms very disparate in phenotype, ecology and behaviour. Today, in the central part of South America there is one dominant large species (the maned wolf, Chrysocyon brachyurus ) that directly influence sympatric smaller taxa via interspecific killing. Further south, three species of similar sized foxes ( Lycalopex spp.) share the same habitats. Such unique combination of taxa and geographic distribution makes South American dogs an ideal group to test for the simultaneous impact of climate and competition on phenotypic variation. Using geometric morphometrics, we quantified skull size and shape of 431 specimens belonging to the eight extant South American canid species: Atelocynus microtis , Cerdocyon thous , Ch. brachyurus , Lycalopex culpaeus , L. griseus , L. gymnocercus , L. vetulus and Speothos venaticus . South American canids are significantly different in both skull size and shape. The hypercarnivorous bush dog is mostly distinct in shape from all the other taxa while a degree of overlap in shape-but not size-occurs between species of the genus Lycalopex . Both climate and competition impacts interspecific morphological variation. We identified climatic adaptations as the main driving force of diversification for the South American canids. Competition has a lower degree of impact on their skull morphology although it might have played a role in the past, when canid community was richer in morphotypes.

  8. English or Perish: How Contemporary South Korea Received, Accommodated, and Internalized English and American Modernity

    Science.gov (United States)

    Lee, JongHwa; Han, Min Wha; McKerrow, Raymie E.

    2010-01-01

    This paper discusses the positionality of English in South Korea as a form of symbolic capital that represents the discursive power of Americanism and East Asian Social Darwinism. By employing Bourdieu's and Foucault's theoretical orientations, this paper traces how South Korean linguistic policies to incorporate English loan words coincide with…

  9. Afrikaans, American and British models for South African English ...

    African Journals Online (AJOL)

    This article examines the treatment of racial labels in monolingual English dictionaries of South Africa. Considering past controversies regarding racist language in Afrikaans dictionaries and considering the changing role of English in democratic South Africa, we can expect that English dictionaries will be more carefully ...

  10. Network companies: a new phenomenon in South American farming

    NARCIS (Netherlands)

    Clasadonte, L.; Vries, de E.; Trienekens, J.H.; Arbeletche, P.

    2013-01-01

    Purpose – South America is an important agricultural producer. Farming is characterized by the availability of vast areas of land, a reasonable climate and low cost. These conditions have led South America to be an important supplier of agricultural goods on the world market. Traditionally farmers

  11. The water economy of South American desert rodents: from integrative to molecular physiological ecology.

    Science.gov (United States)

    Bozinovic, Francisco; Gallardo, Pedro

    2006-01-01

    Rodents from arid and semi-arid habitats live under conditions where the spatial and temporal availability of free water is limited, or scarce, thus forcing these rodents to deal with the problem of water conservation. The response of rodents to unproductive desert environments and water deficits has been intensively investigated in many deserts of the world. However, current understanding of the cellular, systemic and organismal physiology of water economy relies heavily on short-term, laboratory-oriented experiments, which usually focus on responses at isolated levels of biological organization. In addition, studies in small South American mammals are scarce. Indeed xeric habitats have existed in South America for a long time and it is intriguing why present day South American desert rodents do not show the wide array of adaptive traits to desert life observed for rodents on other continents. Several authors have pointed out that South American desert rodents lack physiological and energetic specialization for energy and water conservation, hypothesizing that their success is based more on behavioral and ecological strategies. We review phenotypic flexibility and physiological diversity in water flux rate, urine osmolality, and expression of water channels in South American desert-dwelling rodents. As far as we know, this is the first review of integrative studies at cellular, systemic and organismal levels. Our main conclusion is that South American desert rodents possess structural as well as physiological systems for water conservation, which are as remarkable as those found in "classical" rodents inhabiting other desert areas of the world.

  12. African American Medical Culture in the Antebellum South: As Remembered in the WPA Narratives

    OpenAIRE

    Barber, Daniel

    2015-01-01

    This project examines the oral accounts of former slaves, as recorded in the WPA narratives in the 1930s, to study the development of African American medical culture in the Antebellum South. Through an examination of these transcribed memories, my research investigates how African American praxes with medicinal flora, healing techniques, and spiritual harmony, reflected their ethnomedical and cosmological ideologies. The duality of these ideologies represents an African American medical iden...

  13. Exploring opportunities and challenges for establishing a South American Space Agency

    Science.gov (United States)

    Silva-Martinez, Jackelynne P.; Aguilar, Andrés D.; Sarli, Bruno V.; Pardo Spiess, Monika Johanna; Sorice, Andreia F.; Genaro, Gino; Ojeda, Oscar I.

    2018-06-01

    The idea of establishing a South American Space Agency (SASA) is not new. There have been many discussions about this topic for a couple of decades, including an agreement by the Union of South American Nations to create such a space agency. Roughly 10 years ago, Argentina was the first to propose this collaboration with a military orientation. As the ideas progressed, Brazil was proposed to host its headquarters. However, not much support from the South American region has been given, either financially or logistically. To this day, a South American Space Agency or a similar concept has not yet been established in the region. The Space Generation Advisory Council (SGAC) hosted the first South American Space Generation Workshop in Argentina in 2015, where one of the working groups was tasked to further investigate the feasibility, advantages and challenges of implementing SASA. This paper presents an extension of the main findings from this working group where South American students and young professionals study and present a rationale in favor of SASA, outlining possible solutions and a structure that could be taken into account for its implementation. This paper pays particular attention to the question: Is it possible for countries in South America to establish the kind of cooperation necessary to stimulate the development and application of capabilities in the space sector, which would then enable undertaking missions far beyond the scope of what any single country in South America could do on its own? The existence of SASA would allow access to a common representative agency, which would lower costs, be accessible to all participating countries, and allow engagement with other emerging and established space agencies around the world.

  14. Sources of Anti-Americanism in South Korea

    National Research Council Canada - National Science Library

    Hong, Young P

    2008-01-01

    .... To accomplish this, three areas will be researched. First, the transformation from an authoritarian regime to a democratic government in the 1990s has provided previously unheard of democratic freedom in South Korean society...

  15. Cyberbullying in South African and American schools: A legal ...

    African Journals Online (AJOL)

    Hennie

    Studies on violence in the workplace and on bullying in. South Africa are .... famatory, constituting bullying, harassment or discrimination ..... bullying effectively, and do not guide educators on ... Prevention and Management of Sexual Violence.

  16. On the mechanisms of induction of the cells polyploidization

    International Nuclear Information System (INIS)

    Kair, M.B.; Gil'yano, N.Ya.; Malinovskij, O.V.

    1992-01-01

    In rats liver hepatocytes two mechanisms of polyploidization, induced by ionizing radiation have been shown; polyploidization of cells takes place in the result of mitosis blocking, whereas during the irradiation by dense ionizing radiation polyploidization is realized at the expense of cells confluence. It is supposed that in case of polyploidization induction by dense ionizing radiation the target is the cellular membrane. The evidence of this suggestion has been recorded.Induction of hepatocytes confluence by neutrons with various energies, as well as age dependent changes in the effect of hepatocytes confluence, induced by neutrons were obtained. (author). 7 refs., 6 figs

  17. “Liting it up”: Popular Culture, Indo-Pak Basketball, and South Asian American Institutions

    Directory of Open Access Journals (Sweden)

    Stanley Ilango Thangaraj

    2010-08-01

    Full Text Available South Asian American participants of a co-ethnic basketball league, known as Indo-Pak Basketball, utilized urban basketball vernacular through the phrase “liting it up” to identify individuals scoring points in great numbers. The person “liting it up” becomes visible and receives recognition. Accordingly, I want to “lite up” the scholarship on South Asian America whereby situating South Asian American religious sites and cultural centers as key arenas for “Americanization” through US popular culture. I situate sport as a key element of popular culture through which South Asian American communities work out, struggle through, and contest notions of self. Informed by an Anthropology of Sport, ethnography of South Asian American communities in Atlanta takes place alongside an examination of the North American Indo-Pak Basketball circuit. Accordingly, my findings indicate that such community formation has also taken shape at the intersections of institutions, gender, and sexuality whereby excluding queers, women, and other communities of color.

  18. Close relationship of Plasmodium sequences detected from South American pampas deer (Ozotoceros bezoarticus to Plasmodium spp. in North American white-tailed deer

    Directory of Open Access Journals (Sweden)

    Masahito Asada

    2018-04-01

    Full Text Available We report, for the first time, the presence of ungulate malaria parasites in South America. We conducted PCR-based surveys of blood samples of multiple deer species and water buffalo from Brazil and detected Plasmodium sequences from pampas deer (Ozotoceros bezoarticus samples. Phylogenic analysis revealed that the obtained sequences are closely related to the Plasmodium odocoilei clade 2 sequence from North American white-tailed deer (Odocoileus virginianus. Nucleotide differences suggest that malaria parasites in South American pampas deer and North American P. odocoilei clade 2 branched more recently than the Great American Interchange. Keywords: Malaria, Pampas deer, South America, Plasmodium odocoilei, Brazil

  19. Cyberbullying in South African and American schools: A legal ...

    African Journals Online (AJOL)

    Hennie

    stressed (Burton & Mutongwizo, 2009); the educational institution should ... especially in South Africa, where this has claimed the lives of both learners and ... Studies on violence in the workplace and on bullying in ... tives, and to balance the rights of the various parties in a school environment. ...... School social workers'.

  20. Radioactive mineral potential of carbonatites in western parts of the South American shields

    International Nuclear Information System (INIS)

    Premoli, C.; Kroonenberg, S.B.

    1984-01-01

    During the last eight years at least six carbonatites or clusters of carbonatites have been discovered in the western parts of the South American cratons. In contrast to the carbonatites of the eastern part of the South American shields, which have been well studied and placed in a tectonic context together with the West African carbonatite provinces, those of the western part of the South American cratons have received litte attention. This paper is a compilation of published and original data on these occurrences, their geology, geochemistry, structural setting and radioactive mineral potential. An exploration strategy is devised based on experiences in this rainforest-clad area and the peculiar genetic aspect of carbonatites. Some details of a possibly new uranium mineral encountered in Cerro Cora carbonatite are given. (author)

  1. The fossil record of South American short-faced bears (Ursidae, Tremarctinae)

    OpenAIRE

    Bond, Mariano; Tonni, Eduardo Pedro; Soibelzon, Leopoldo Héctor

    2005-01-01

    The present study includes a review of the geographic and stratigraphic distribution of short-faced bears (Ursidae, Tremarctinae) in South America. In addition, the authors discuss biogeographic hypotheses regarding the origin of South American tremarctines. The Tremarctinae subfamily is distributed exclusively in America, from Alaska to southern Patagonia. Its biochron comprises the temporal lapse between Late Miocene and recent times; the first record of Tremarctinae in North America corres...

  2. Segmenting the Latin American travel market to South Africa

    Directory of Open Access Journals (Sweden)

    Martinette Kruger

    2017-03-01

    Full Text Available Orientation and motive of research: Tourism growth to South Africa is in decline resulting in an emphasis shift to identify new markets to offset the slowdown in tourism growth. Purpose of research: This study identified viable target markets within the Latin America tourist market using market segmentation based on motivations to travel to South Africa. Results and findings: Four viable segments were identified that should be catered for and, based on the distinct characteristics of each market, marketing strategies are proposed. Practical implications: This study makes a valuable contribution to the current tourism literature by expanding current knowledge of the profile and motives of a, to date, relatively unknown tourist market.

  3. Employing Strategic Thinking in South American 4icrofinance Institutions

    Directory of Open Access Journals (Sweden)

    CONCARI, GUSTAVO

    2014-05-01

    Full Text Available The article is about the use of strategic thinking in microfinance in South America. Microfinance is an important business in South America today, its importance lies in its ability to transform poor people and informal enterprises into citizens and formal companies making human beings grow as individuals at the same time. The sector is very strong in the region despite its youth and maybe it's time to use the ideas of business strategy developed for traditional businesses. The goal of this paper is then to use the ideas of business strategy in microfinance. A classic strategy scheme called the Ansoff matrix is used for this. It proposes two axes (product and market as possible ways for developing a business. The work includes the theoretical development of this scheme and evaluations from experts interviewed to give their opinion on it, evaluations that make the idea richer while pointing the possible weaknesses of the model

  4. Atypical E2f functions are critical for pancreas polyploidization.

    Directory of Open Access Journals (Sweden)

    Ramadhan B Matondo

    Full Text Available The presence of polyploid cells in the endocrine and exocrine pancreas has been reported for four decades. In rodents, pancreatic polyploidization is initiated after weaning and the number of polyploid cells increases with age. Surprisingly the molecular regulators and biological functions of polyploidization in the pancreas are still unknown. We discovered that atypical E2f activity is essential for polyploidization in the pancreas, using an inducible Cre/LoxP approach in new-born mice to delete ubiquitously the atypical E2f transcription factors, E2f7 and E2f8. In contrast to its critical role in embryonic survival, conditional deletion of both of both atypical E2fs in newborn mice had no impact on postnatal survival and mice lived until old age. However, deficiency of E2f7 or E2f8 alone was sufficient to suppress polyploidization in the pancreas and associated with only a minor decrease in blood serum levels of glucose, insulin, amylase and lipase under 4 hours starvation condition compared to wildtype littermates. In mice with fewer pancreatic polyploid cells that were fed ad libitum, no major impact on hormones or enzymes levels was observed. In summary, we identified atypical E2fs to be essential for polyploidization in the pancreas and discovered that postnatal induced loss of both atypical E2fs in many organs is compatible with life until old age.

  5. DNA Damage Signaling Instructs Polyploid Macrophage Fate in Granulomas

    DEFF Research Database (Denmark)

    Herrtwich, Laura; Nanda, Indrajit; Evangelou, Konstantinos

    2016-01-01

    to a chronic stimulus, though critical for disease outcome, have not been defined. Here, we delineate a macrophage differentiation pathway by which a persistent Toll-like receptor (TLR) 2 signal instructs polyploid macrophage fate by inducing replication stress and activating the DNA damage response. Polyploid...

  6. Atypical E2f functions are critical for pancreas polyploidization.

    Science.gov (United States)

    Matondo, Ramadhan B; Moreno, Eva; Toussaint, Mathilda J M; Tooten, Peter C J; van Essen, Saskia C; van Liere, Elsbeth A; Youssef, Sameh A; Bongiovanni, Laura; de Bruin, Alain

    2018-01-01

    The presence of polyploid cells in the endocrine and exocrine pancreas has been reported for four decades. In rodents, pancreatic polyploidization is initiated after weaning and the number of polyploid cells increases with age. Surprisingly the molecular regulators and biological functions of polyploidization in the pancreas are still unknown. We discovered that atypical E2f activity is essential for polyploidization in the pancreas, using an inducible Cre/LoxP approach in new-born mice to delete ubiquitously the atypical E2f transcription factors, E2f7 and E2f8. In contrast to its critical role in embryonic survival, conditional deletion of both of both atypical E2fs in newborn mice had no impact on postnatal survival and mice lived until old age. However, deficiency of E2f7 or E2f8 alone was sufficient to suppress polyploidization in the pancreas and associated with only a minor decrease in blood serum levels of glucose, insulin, amylase and lipase under 4 hours starvation condition compared to wildtype littermates. In mice with fewer pancreatic polyploid cells that were fed ad libitum, no major impact on hormones or enzymes levels was observed. In summary, we identified atypical E2fs to be essential for polyploidization in the pancreas and discovered that postnatal induced loss of both atypical E2fs in many organs is compatible with life until old age.

  7. Relevance of sexual polyploidization for crop improvement - A review

    NARCIS (Netherlands)

    Ramanna, M.S.; Jacobsen, E.

    2003-01-01

    Colchicine induced polyploids have not directly contributed for crop improvement in the past. On the other hand, the so-called natural polyploids, derived from the functioning of numerically unreduced (2n) gametes have been shown to be more relevant for crop improvement in many cases. Different

  8. High-energy physics, the South American way

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    The 6th CERN–Latin American School of High-Energy Physics (CLASHEP) was held in Brazil from 23 March to 5 April. With its record-breaking attendance and strong international spirit, CLASHEP is yet another sign of the continent's growing particle physics community.   Participants in the 6th CERN–Latin American School of High-Energy Physics outside the Hotel Porto do Mar, Natal (Brazil), where the School was held. CLASHEP was established in 2001 as a way of engaging young Latin American scientists in the field of particle physics - particularly in the experimental aspects of research. It has played an important role in encouraging Latin American institutes to collaborate with CERN and showing how non-Member-State physicists can work as equals with Member-State nationals. “CLASHEP reflects some of CERN’s guiding policies: enlarging its membership and involving new nations in its programmes,” says Nick Ellis, director of the CERN Schools of High-Ene...

  9. Tools for Genetic Studies in Experimental Populations of Polyploids

    Directory of Open Access Journals (Sweden)

    Peter M. Bourke

    2018-04-01

    Full Text Available Polyploid organisms carry more than two copies of each chromosome, a condition rarely tolerated in animals but which occurs relatively frequently in the plant kingdom. One of the principal challenges faced by polyploid organisms is to evolve stable meiotic mechanisms to faithfully transmit genetic information to the next generation upon which the study of inheritance is based. In this review we look at the tools available to the research community to better understand polyploid inheritance, many of which have only recently been developed. Most of these tools are intended for experimental populations (rather than natural populations, facilitating genomics-assisted crop improvement and plant breeding. This is hardly surprising given that a large proportion of domesticated plant species are polyploid. We focus on three main areas: (1 polyploid genotyping; (2 genetic and physical mapping; and (3 quantitative trait analysis and genomic selection. We also briefly review some miscellaneous topics such as the mode of inheritance and the availability of polyploid simulation software. The current polyploid analytic toolbox includes software for assigning marker genotypes (and in particular, estimating the dosage of marker alleles in the heterozygous condition, establishing chromosome-scale linkage phase among marker alleles, constructing (short-range haplotypes, generating linkage maps, performing genome-wide association studies (GWAS and quantitative trait locus (QTL analyses, and simulating polyploid populations. These tools can also help elucidate the mode of inheritance (disomic, polysomic or a mixture of both as in segmental allopolyploids or reveal whether double reduction and multivalent chromosomal pairing occur. An increasing number of polyploids (or associated diploids are being sequenced, leading to publicly available reference genome assemblies. Much work remains in order to keep pace with developments in genomic technologies. However, such

  10. Tools for Genetic Studies in Experimental Populations of Polyploids.

    Science.gov (United States)

    Bourke, Peter M; Voorrips, Roeland E; Visser, Richard G F; Maliepaard, Chris

    2018-01-01

    Polyploid organisms carry more than two copies of each chromosome, a condition rarely tolerated in animals but which occurs relatively frequently in the plant kingdom. One of the principal challenges faced by polyploid organisms is to evolve stable meiotic mechanisms to faithfully transmit genetic information to the next generation upon which the study of inheritance is based. In this review we look at the tools available to the research community to better understand polyploid inheritance, many of which have only recently been developed. Most of these tools are intended for experimental populations (rather than natural populations), facilitating genomics-assisted crop improvement and plant breeding. This is hardly surprising given that a large proportion of domesticated plant species are polyploid. We focus on three main areas: (1) polyploid genotyping; (2) genetic and physical mapping; and (3) quantitative trait analysis and genomic selection. We also briefly review some miscellaneous topics such as the mode of inheritance and the availability of polyploid simulation software. The current polyploid analytic toolbox includes software for assigning marker genotypes (and in particular, estimating the dosage of marker alleles in the heterozygous condition), establishing chromosome-scale linkage phase among marker alleles, constructing (short-range) haplotypes, generating linkage maps, performing genome-wide association studies (GWAS) and quantitative trait locus (QTL) analyses, and simulating polyploid populations. These tools can also help elucidate the mode of inheritance (disomic, polysomic or a mixture of both as in segmental allopolyploids) or reveal whether double reduction and multivalent chromosomal pairing occur. An increasing number of polyploids (or associated diploids) are being sequenced, leading to publicly available reference genome assemblies. Much work remains in order to keep pace with developments in genomic technologies. However, such technologies

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

    Science.gov (United States)

    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.

  12. Sarcoptic Mange in a South American Gray Fox (Chilla Fox; Lycalopex griseus ), Chile.

    Science.gov (United States)

    Verdugo, Claudio; Espinoza, Angelo; Moroni, Manuel; Valderrama, Rocio; Hernandez, Carlos

    2016-07-01

    Mange, a prevalent disease of dogs in Chile, is also a serious threat to wildlife. We report a case of sarcoptic mange in a South American gray fox or chilla fox ( Lycalopex griseus ). Further research is needed to understand the impact of mange in wildlife populations.

  13. Spirits of the Air: Birds and American Indians in the South

    Directory of Open Access Journals (Sweden)

    E. N. Anderson

    2010-08-01

    Full Text Available Review of Spirits of the Air: Birds and American Indians in the South. Shepard Krech III. 2009. University of Georgia Press, Athens. Pp. 245, copiously illustrated. $44.95 (hardbound. ISBN-13 978-0-8203-2815-7.

  14. Coping with Discrimination: The Subjective Well-Being of South Asian American Women

    Science.gov (United States)

    Liang, Christopher T. H.; Nathwani, Anisha; Ahmad, Sarah; Prince, Jessica K.

    2010-01-01

    The relationship between coping strategies used by South Asian American women and subjective well-being (SWB) was studied. Second-generation women were found to use more support compared with 1st-generation women. Problem-solving coping was inversely related to age. Avoidance coping was found to predict SWB when controlling for age and…

  15. The South American Mailed Catfishes of the genus Pseudoloricaria Bleeker, 1862 (Pisces, Siluriformes, Loricariidae)

    NARCIS (Netherlands)

    Isbrücker, I.J.H.; Nijssen, H.

    1976-01-01

    Two species of South American Mailed Catfishes of the genus Pseudoloricaria Bleeker, 1862 are redescribed and figured from type-specimens and additional material: Pseudoloricaria laeviuscula (Valenciennes, 1840), and Pseudoloricaria punctata (Regan, 1904). Since the provenance of the holotype of P.

  16. Three new South American mailed catfishes of the genera Rineloricaria and Loricariichthys (Pisces, Siluriformes, Loricariide)

    NARCIS (Netherlands)

    Isbrücker, I.J.H.; Nijssen, H.

    1979-01-01

    Three new species belonging to two different genera of South American mailed catfishes of the subfamily Loricariinae are described and figured. A discussion of and comparative notes on related species are added. Rineloricaria formosa n. sp. is described from the Río Inírida/Río Orinoco drainage in

  17. Ectoparasites from the South American sea lion (Otaria flavescens from Peruvian coast

    Directory of Open Access Journals (Sweden)

    Luis A. Gomez-Puerta

    2015-10-01

    Full Text Available Two species of ectoparasites were collected from a South American sea lion (Otaria flavescens found stranded on the beaches of Chorrillos in Lima, Peru. The ectoparasites were identified as Antarctophthirus microchir (Phthiraptera and Orthohalarachne attenuata (Acari. Some morphological characteristics are described in this report. The finding of these ectoparasites is the first records in Peru.

  18. Ichthyophonus sp. (Ichthyophonae, Ichthyophonida) infection in a South American amphibian, the hylid frog Hypsiboas pulchellus.

    Science.gov (United States)

    Borteiro, Claudio; Verdes, José Manuel; Cruz, Juan Carlos; Sabalsagaray, María Jesús; Kolenc, Francisco; Martínez Debat, Claudio; Ubilla, Martín

    2015-04-01

    We report infection by Ichthyophonus sp. in a South American amphibian, the hylid frog Hypsiboas pulchellus in Uruguay. This frog had a large subcutaneous mass over the urostyle and dorsal musculature comprised of parasitic cysts with mild granulomatous inflammation but otherwise appeared healthy.

  19. South American energy integration: new perspectives; Novas perspectivas para a integracao energetica sul-americana

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jose Malhaes da [Malhaes da Silva Consultoria Ltda., Rio de Janeiro, RJ (Brazil); Salomao, Luiz Alfredo [Universidade Candido Mendes, Rio de Janeiro, RJ (Brazil). Escola de Politicas Publicas e Governo

    2008-07-01

    This paper analyses the South American energy integration, the advantages related to this process as well as the existing obstacles . What is the scope in terms of projects and initiatives, and the role of political and institutional barriers to be overcome. (author)

  20. Perspectives of the mercosur parliament performance according to south american political organization

    Directory of Open Access Journals (Sweden)

    Clarissa Franzoi Dri

    2007-04-01

    Full Text Available The signature of the MERCOSUR Parliament Constitutive Protocol, in 2005, has opened new parliamentary perspectives to the integration process which takes place in the South Cone. The nomination “parliament”, the universal suffrage prevision and new legislative and control functions evidence possibilities for an outstanding actuation. But is it possible to consider that this new organ was created in the middle of political conditions favorable to an effective functionality? Looking for traces to an answer, the paper examines political and electoral characteristics common to the South American States. First, we study the daily relations between the Executive and Legislative Powers in South American presidential regimes. Then, we verify to what extent the proportional open-list electoral system, largely used in the election of the lower houses members in the continent, influences such relations. At the end, we discuss the new assembly perspectives of effectiveness based on the regional characteristics studied.

  1. Daily and seasonal activity patterns of free range South-American rattlesnake (Crotalus durissus

    Directory of Open Access Journals (Sweden)

    ALEXANDRO M. TOZETTI

    2013-09-01

    Full Text Available This study aimed at describing daily and seasonal variation in the activity of a population of South-American rattlesnakes (Crotalus durissus in a savanna like habitat (Cerrado in Southeastern Brazil. Seasonal and daily activities of snakes were evaluated by the number of captures of snakes during road surveys, accidental encounters, and relocations by radio-tracking. Our results show that climatic variables such as air temperature and rainfall have little influence on the activity pattern of rattlesnakes. Our findings indicate that rattlesnakes spend most of the day resting and most of the night in ambush posture. The South-American rattlesnake is active throughout the year with a discrete peak in activity of males during the matting season. The possibility of maintaining activity levels even during the coldest and driest season can facilitate the colonization of several habitats in South America. This possibility currently facilitates the colonization of deforested areas by rattlesnakes.

  2. Daily and seasonal activity patterns of free range South-American rattlesnake (Crotalus durissus).

    Science.gov (United States)

    Tozetti, Alexandro M; Martins, Marcio

    2013-09-01

    This study aimed at describing daily and seasonal variation in the activity of a population of South-American rattlesnakes (Crotalus durissus) in a savanna like habitat (Cerrado) in Southeastern Brazil. Seasonal and daily activities of snakes were evaluated by the number of captures of snakes during road surveys, accidental encounters, and relocations by radio-tracking. Our results show that climatic variables such as air temperature and rainfall have little influence on the activity pattern of rattlesnakes. Our findings indicate that rattlesnakes spend most of the day resting and most of the night in ambush posture. The South-American rattlesnake is active throughout the year with a discrete peak in activity of males during the matting season. The possibility of maintaining activity levels even during the coldest and driest season can facilitate the colonization of several habitats in South America. This possibility currently facilitates the colonization of deforested areas by rattlesnakes.

  3. Response of South American Ecosystems to Precipitation Variability

    Science.gov (United States)

    Knox, R. G.; Kim, Y.; Longo, M.; Medvigy, D.; Wang, J.; Moorcroft, P. R.; Bras, R. L.

    2009-12-01

    The Ecosystem Demography Model 2 is a dynamic ecosystem model and land surface energy balance model. ED2 discretizes landscapes of particular terrain and meteorology into fractional areas of unique disturbance history. Each fraction, defined by a shared vertical soil column and canopy air space, contains a stratum of plant groups unique in functional type, size and number density. The result is a vertically distributed representation of energy transfer and plant dynamics (mortality, productivity, recruitment, disturbance, resource competition, etc) that successfully approximates the behaviour of individual-based vegetation models. In previous exercises simulating Amazonian land surface dynamics with ED 2, it was observed that when using grid averaged precipitation as an external forcing the resulting water balance typically over-estimated leaf interception and leaf evaporation while under estimating through-fall and transpiration. To investigate this result, two scenario were conducted in which land surface biophysics and ecosystem demography over the Northern portion of South America are simulated over ~200 years: (1) ED2 is forced with grid averaged values taken from the ERA40 reanalysis meteorological dataset; (2) ED2 is forced with ERA40 reanalysis, but with its precipitation re-sampled to reflect statistical qualities of point precipitation found at rain gauge stations in the region. The findings in this study suggest that the equilibrium moisture states and vegetation demography are co-dependent and show sensitivity to temporal variability in precipitation. These sensitivities will need to be accounted for in future projections of coupled climate-ecosystem changes in South America.

  4. South American natural gas trade: the road ahead

    International Nuclear Information System (INIS)

    Reinsch, A.E.; Tissot, R.; Peacey, D.

    1997-01-01

    The current state and future prospects for the natural gas sector in South America were examined, including the ability of the natural gas resource base to meet potential gas demand in the Southern Cone region (Argentina, Bolivia, Brazil, Chile, Paraguay, Peru and Uruguay). The physical, legal, fiscal, regulatory and political developments in the hydrocarbon-producing countries in the Southern Cone region were reviewed. For example, in Colombia, the domestic gas market potential and resource base argue in favor of a closed domestic gas sector development policy. In contrast, Venezuela, a country that already has a well developed domestic gas sector, is pursuing offshore market development through both petrochemical and liquefied natural gas initiatives. Following a comprehensive description of individual gas resources, markets and market potential, and legal, institutional and political environments, the study reports on a number of alternative scenarios concerning natural gas integration in the Southern Cone region, developed by using the South America Natural Gas (SANG) model. The following scenarios were reviewed: (1) closure and confinement, (2) integration and expansion, and (3) gains from technology. It was estimated that potential gas demand in the Southern Cone region is projected to grow from 900 billion cubic feet per year in 1994 to over 5.3 trillion cubic feet in 2021. The majority of growth is expected in Brazil. The overall conclusion of the study was that regardless of the scenario, Southern Core gas sector integration has strong economic and commercial merit, and that the natural gas resource base in the Southern Cone, as represented by the gas reserves database, is more than adequate to service potential demand. 100 refs., 50 tabs., 54 figs

  5. Oxidative stress promotes pathologic polyploidization in nonalcoholic fatty liver disease.

    Science.gov (United States)

    Gentric, Géraldine; Maillet, Vanessa; Paradis, Valérie; Couton, Dominique; L'Hermitte, Antoine; Panasyuk, Ganna; Fromenty, Bernard; Celton-Morizur, Séverine; Desdouets, Chantal

    2015-03-02

    Polyploidization is one of the most dramatic changes that can occur in the genome. In the liver, physiological polyploidization events occur during both liver development and throughout adult life. Here, we determined that a pathological polyploidization takes place in nonalcoholic fatty liver disease (NAFLD), a widespread hepatic metabolic disorder that is believed to be a risk factor for hepatocellular carcinoma (HCC). In murine models of NAFLD, the parenchyma of fatty livers displayed alterations of the polyploidization process, including the presence of a large proportion of highly polyploid mononuclear cells, which are rarely observed in normal hepatic parenchyma. Biopsies from patients with nonalcoholic steatohepatitis (NASH) revealed the presence of alterations in hepatocyte ploidy compared with tissue from control individuals. Hepatocytes from NAFLD mice revealed that progression through the S/G2 phases of the cell cycle was inefficient. This alteration was associated with activation of a G2/M DNA damage checkpoint, which prevented activation of the cyclin B1/CDK1 complex. Furthermore, we determined that oxidative stress promotes the appearance of highly polyploid cells, and antioxidant-treated NAFLD hepatocytes resumed normal cell division and returned to a physiological state of polyploidy. Collectively, these findings indicate that oxidative stress promotes pathological polyploidization and suggest that this is an early event in NAFLD that may contribute to HCC development.

  6. Myocardial Polyploidization Creates a Barrier to Heart Regeneration in Zebrafish.

    Science.gov (United States)

    González-Rosa, Juan Manuel; Sharpe, Michka; Field, Dorothy; Soonpaa, Mark H; Field, Loren J; Burns, Caroline E; Burns, C Geoffrey

    2018-02-26

    Correlative evidence suggests that polyploidization of heart muscle, which occurs naturally in post-natal mammals, creates a barrier to heart regeneration. Here, we move beyond a correlation by demonstrating that experimental polyploidization of zebrafish cardiomyocytes is sufficient to suppress their proliferative potential during regeneration. Initially, we determined that zebrafish myocardium becomes susceptible to polyploidization upon transient cytokinesis inhibition mediated by dominant-negative Ect2. Using a transgenic strategy, we generated adult animals containing mosaic hearts composed of differentially labeled diploid and polyploid-enriched cardiomyocyte populations. Diploid cardiomyocytes outcompeted their polyploid neighbors in producing regenerated heart muscle. Moreover, hearts composed of equivalent proportions of diploid and polyploid cardiomyocytes failed to regenerate altogether, demonstrating that a critical percentage of diploid cardiomyocytes is required to achieve heart regeneration. Our data identify cardiomyocyte polyploidization as a barrier to heart regeneration and suggest that mobilizing rare diploid cardiomyocytes in the human heart will improve its regenerative capacity. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. True polyploid meiosis in the human male.

    Science.gov (United States)

    Pearson, Peter L; Madan, Kamlesh

    2018-05-21

    Polyploidy does not usually occur in germinal cells of mammals and other higher vertebrates. We describe a unique example of mosaic autotetraploidy in the meiosis of a human male. Although the original observations were made in the late 1960s, we did not publish them at that time, because we expected to detect further examples that could be described together. However, this did not occur and we have now decided to make the observations available to demonstrate that polyploidy in mammalian male meiosis can arise at a higher frequency than expected by random polyploidization of individual meiotic cells, by either DNA duplication or cell fusion prior to synapsis. This is the first description of a population of primary spermatocytes exhibiting multivalent formation at leptotene /diakinesis in human spermatogenesis, with ring, chain, frying pan and other types of quadrivalents, typical of autotetraploidy. As many of the polyploid configurations showed apoptotic breakdown, it is likely that diploid and/or aneuploid spermatozoa would have rarely or never resulted from this mosaic autotetraploid meiosis.

  8. Exogenous CO2 in South American sparkling wine

    Directory of Open Access Journals (Sweden)

    Leonardelli Susiane

    2016-01-01

    Full Text Available The sparkling wine production and consumption have increased significantly in the last years. With the increased demand appear the necessity to check the sparkling wine authenticity, because the practice of adding CO2 in sparkling wine is not allow. A way to control the carbonation process is through the determination of CO2 δ13C, because the sugar added during the second fermentation define the CO2 isotopic value, according to elaboration process. For this reason, the aim of this study was to evaluate the relationship between values of δ13C from still wines and sparkling wines, in order to set up limit values to exogenous carbonation control. Thirty-eight still wines elaborated by microvinification and 59 samples of commercial sparkling wines were analyzed, using an isotope ratio mass spectrometer (IRMS. The most negative value of natural δ13C from still wine found was − 24.7‰, it can be to estimate that lowest values are an indicative of industrial CO2 addition. Among the commercial sparkling wine from South America evaluated in this study, 10% from the samples showed signs of carbonation. Through this research was possible to establish limits of isotopic values to determine the presence of exogenous CO2.

  9. South American collaboration in scientific publications on leishmaniasis: bibliometric analysis in SCOPUS (2000-2011).

    Science.gov (United States)

    Huamaní, Charles; Romaní, Franco; González-Alcaide, Gregorio; Mejia, Miluska O; Ramos, José Manuel; Espinoza, Manuel; Cabezas, César

    2014-01-01

    Evaluate the production and the research collaborative network on Leishmaniasis in South America. A bibliometric research was carried out using SCOPUS database. The analysis unit was original research articles published from 2000 to 2011, that dealt with leishmaniasis and that included at least one South American author. The following items were obtained for each article: journal name, language, year of publication, number of authors, institutions, countries, and others variables. 3,174 articles were published, 2,272 of them were original articles. 1,160 different institutional signatures, 58 different countries and 398 scientific journals were identified. Brazil was the country with more articles (60.7%) and Oswaldo Cruz Foundation (FIOCRUZ) had 18% of Brazilian production, which is the South American nucleus of the major scientific network in Leishmaniasis. South American scientific production on Leishmaniasis published in journals indexed in SCOPUS is focused on Brazilian research activity. It is necessary to strengthen the collaboration networks. The first step is to identify the institutions with higher production, in order to perform collaborative research according to the priorities of each country.

  10. SOUTH AMERICAN COLLABORATION IN SCIENTIFIC PUBLICATIONS ON LEISHMANIASIS: BIBLIOMETRIC ANALYSIS IN SCOPUS (2000-2011

    Directory of Open Access Journals (Sweden)

    Charles Huamaní

    2014-09-01

    Full Text Available Objectives: Evaluate the production and the research collaborative network on Leishmaniasis in South America. Methods: A bibliometric research was carried out using SCOPUS database. The analysis unit was original research articles published from 2000 to 2011, that dealt with leishmaniasis and that included at least one South American author. The following items were obtained for each article: journal name, language, year of publication, number of authors, institutions, countries, and others variables. Results: 3,174 articles were published, 2,272 of them were original articles. 1,160 different institutional signatures, 58 different countries and 398 scientific journals were identified. Brazil was the country with more articles (60.7% and Oswaldo Cruz Foundation (FIOCRUZ had 18% of Brazilian production, which is the South American nucleus of the major scientific network in Leishmaniasis. Conclusions: South American scientific production on Leishmaniasis published in journals indexed in SCOPUS is focused on Brazilian research activity. It is necessary to strengthen the collaboration networks. The first step is to identify the institutions with higher production, in order to perform collaborative research according to the priorities of each country.

  11. Muzzle of South American Pleistocene ground sloths (Xenarthra, Tardigrada).

    Science.gov (United States)

    Bargo, M Susana; Toledo, Néstor; Vizcaíno, Sergio F

    2006-02-01

    Sloths are among the most characteristic elements of the Cainozoic of South America and are represented, during the Pleistocene, by approximately nine genera of gigantic ground sloths (Megatheriidae and Mylodontidae). A few contributions have described their masticatory apparatus, but almost no attention has been paid to the reconstruction of the muzzle, an important feature to consider in relation to food intake, and particularly relevant in sloths because of the edentulous nature of the muzzle and its varied morphology. The relationship between dietary habits and shape and width of the muzzle is well documented in living herbivores and has been considered an important feature for the inference of alimentary styles in fossils, providing an interesting methodological tool that deserves to be considered for xenarthrans. The goal of this study was to examine models of food intake by reconstructing the appearance and shape of the muzzle in five species of Pleistocene ground sloths (Megatherium americanum, Glossotherium robustum, Lestodon armatus, Mylodon darwini, and Scelidotherium leptocephalum) using reconstructions of the nasal cartilages and facial muscles involved in food intake. The preservation of the nasal septum, and the scars for muscular attachment in the rostral part of the skulls, allow making a conservative reconstruction of muzzle anatomy in fossil sloths. Wide-muzzled ground sloths (Glossotherium and Lestodon) had a square, nonprehensile upper lip and were mostly bulk-feeders. The lips, coupled with the tongue, were used to pull out grass and herbaceous plants. Narrow-muzzled sloths (Mylodon, Scelidotherium, and Megatherium) had a cone-shaped and prehensile lip and were mixed or selective feeders. The prehensile lip was used to select particular plants or plant parts. (c) 2005 Wiley-Liss, Inc.

  12. Ocean-atmosphere forcing of South American tropical paleoclimate, LGM to present

    Science.gov (United States)

    Baker, P. A.; Fritz, S. C.; Dwyer, G. S.; Rigsby, C. A.; Silva, C. G.; Burns, S. J.

    2012-12-01

    Because of many recent terrestrial paleoclimatic and marine paleoceanographic records, late Quaternary South American tropical paleoclimate is as well understood as that anywhere in the world. While lessons learned from the recent instrumental record of climate are informative, this record is too short to capture much of the lower frequency variability encountered in the paleoclimate records and much of the observed paleoclimate is without modern analogue. This paleoclimate is known to be regionally variable with significant differences both north and south of the equator and between the western high Andes and eastern lowlands of the Amazon and Nordeste Brazil. Various extrinsic forcing mechanisms affected climate throughout the period, including global concentrations of GHGs, Northern Hemisphere ice sheet forcing, seasonal insolation forcing of the South American summer monsoon (SASM), millennial-scale Atlantic forcing, and Pacific forcing of the large-scale Walker circulation. The magnitude of the climate response to these forcings varied temporally, largely because of the varying amplitude of the forcing itself. For example, during the last glacial, large-amplitude north Atlantic forcing during Heinrich 1 and the LGM itself, led to wet (dry) conditions south (north) of the equator. During the Holocene, Atlantic forcing was lower amplitude, thus seasonal insolation forcing generally predominated with a weaker-than-normal SASM during the early Holocene resulting in dry conditions in the south-western tropics and wet conditions in the eastern lowlands and Nordeste; in the late Holocene seasonal insolation reached a maximum in the southern tropics and climate conditions reversed.

  13. Influence of Surface Processes over Africa on the Atlantic Marine ITCZ and South American Precipitation.

    Science.gov (United States)

    Hagos, Samson M.; Cook, Kerry H.

    2005-12-01

    Previous studies show that the climatological precipitation over South America, particularly the Nordeste region, is influenced by the presence of the African continent. Here the influence of African topography and surface wetness on the Atlantic marine ITCZ (AMI) and South American precipitation are investigated.Cross-equatorial flow over the Atlantic Ocean introduced by north south asymmetry in surface conditions over Africa shifts the AMI in the direction of the flow. African topography, for example, introduces an anomalous high over the southern Atlantic Ocean and a low to the north. This results in a northward migration of the AMI and dry conditions over the Nordeste region.The implications of this process on variability are then studied by analyzing the response of the AMI to soil moisture anomalies over tropical Africa. Northerly flow induced by equatorially asymmetric perturbations in soil moisture over northern tropical Africa shifts the AMI southward, increasing the climatological precipitation over northeastern South America. Flow associated with an equatorially symmetric perturbation in soil moisture, however, has a very weak cross-equatorial component and very weak influence on the AMI and South American precipitation. The sensitivity of the AMI to soil moisture perturbations over certain regions of Africa can possibly improve the skill of prediction.

  14. Polyploidization facilitates biotechnological in vitro techniques in the genus Cucumis.

    Science.gov (United States)

    Skálová, Dagmar; Ondřej, Vladan; Doležalová, Ivana; Navrátilová, Božena; Lebeda, Aleš

    2010-01-01

    Prezygotic interspecific crossability barrier in the genus Cucumis is related to the ploidy level of the species (cucumber (C. sativus), x = 7; muskmelon (C. melo) and wild Cucumis species, x = 12). Polyploidization of maternal plants helps hybridization among other Cucumis species by overcoming prezygotic genetic barriers. The main objective of this paper is to compare the results of several methods supporting interspecific crosses in cucumber without and with polyploidization (comparison between diploid (2x) and mixoploid (2x/4x) cucumber maternal plants). Mixoploid plants were obtained after in vivo and in vitro polyploidization by colchicine and oryzalin. Ploidy level was estimated by flow cytometry. Embryo rescue, in vitro pollination, and isolation of mesophyll protoplast were tested and compared. Positive effect of polyploidization was observed during all experiments presented by higher regeneration capacity of cultivated mixoploid cucumber embryos, ovules, and protoplasts. Nevertheless, the hybrid character of putative hybrid accessions obtained after cross in vivo and in vitro pollination was not confirmed.

  15. Diversification in the Andes: age and origins of South American Heliotropium lineages (Heliotropiaceae, Boraginales).

    Science.gov (United States)

    Luebert, Federico; Hilger, Hartmut H; Weigend, Maximilian

    2011-10-01

    The uplift of the Andes was a major factor for plant diversification in South America and had significant effects on the climatic patterns at the continental scale. It was crucial for the formation of the arid environments in south-eastern and western South America. However, both the timing of the major stages of the Andean uplift and the onset of aridity in western South America remain controversial. In this paper we examine the hypothesis that the Andean South American groups of Heliotropium originated and diversified in response to Andean orogeny during the late Miocene and a the subsequent development of aridity. To this end, we estimate divergence times and likely biogeographical origins of the major clades in the phylogeny of Heliotropium, using both Bayesian and likelihood methods. Divergence times of all Andean clades in Heliotropium are estimated to be of late Miocene or Pliocene ages. At least three independent Andean diversification events can be recognized within Heliotropium. Timing of the diversification in the Andean lineages Heliotropium sects.Heliothamnus, Cochranea, Heliotrophytum, Hypsogenia, Plagiomeris, Platygyne clearly correspond to a rapid, late Miocene uplift of the Andes and a Pliocene development of arid environments in South America. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Genomic Imprinting Was Evolutionarily Conserved during Wheat Polyploidization.

    Science.gov (United States)

    Yang, Guanghui; Liu, Zhenshan; Gao, Lulu; Yu, Kuohai; Feng, Man; Yao, Yingyin; Peng, Huiru; Hu, Zhaorong; Sun, Qixin; Ni, Zhongfu; Xin, Mingming

    2018-01-01

    Genomic imprinting is an epigenetic phenomenon that causes genes to be differentially expressed depending on their parent of origin. To evaluate the evolutionary conservation of genomic imprinting and the effects of ploidy on this process, we investigated parent-of-origin-specific gene expression patterns in the endosperm of diploid ( Aegilops spp), tetraploid, and hexaploid wheat ( Triticum spp) at various stages of development via high-throughput transcriptome sequencing. We identified 91, 135, and 146 maternally or paternally expressed genes (MEGs or PEGs, respectively) in diploid, tetraploid, and hexaploid wheat, respectively, 52.7% of which exhibited dynamic expression patterns at different developmental stages. Gene Ontology enrichment analysis suggested that MEGs and PEGs were involved in metabolic processes and DNA-dependent transcription, respectively. Nearly half of the imprinted genes exhibited conserved expression patterns during wheat hexaploidization. In addition, 40% of the homoeolog pairs originating from whole-genome duplication were consistently maternally or paternally biased in the different subgenomes of hexaploid wheat. Furthermore, imprinted expression was found for 41.2% and 50.0% of homolog pairs that evolved by tandem duplication after genome duplication in tetraploid and hexaploid wheat, respectively. These results suggest that genomic imprinting was evolutionarily conserved between closely related Triticum and Aegilops species and in the face of polyploid hybridization between species in these genera. © 2018 American Society of Plant Biologists. All rights reserved.

  17. Hepatocyte polyploidization and its association with pathophysiological processes

    OpenAIRE

    Wang, Min-Jun; Chen, Fei; Lau, Joseph T Y; Hu, Yi-Ping

    2017-01-01

    A characteristic cellular feature of the mammalian liver is the progressive polyploidization of the hepatocytes, where individual cells acquire more than two sets of chromosomes. Polyploidization results from cytokinesis failure that takes place progressively during the course of postnatal development. The proportion of polyploidy also increases with the aging process or with cellular stress such as surgical resection, toxic stimulation, metabolic overload, or oxidative damage, to involve as ...

  18. Distributional patterns of the South American species of Hyalella (Amphipoda: Hyalellidae)

    OpenAIRE

    De los Ríos-Escalante, Patricio; Morrone, Juan J; Rivera, Reinaldo

    2012-01-01

    Distributional patterns of the South American species of the freshwater amphipod genus Hyalella were analysed using a panbiogeographic approach. Five generalized tracks were found: (1) northern Andes to Lake Titicaca (H. dielaii, H. meinerti, H. dybowskii, H.jelskii, H. lubominsky, and H. pauperocavae; (2) lake Titicaca (H. armata, H. cuprea, H. latinamus, H. lucifugax, H. montforti, H. neveulemairei, H. robusta, H. tiwanaku, H. simplex simplex, and H. solida); (3) central Andes (H. fossamanc...

  19. Adhesive and invasive capacities of Edwarsiella tarda isolated from South American sea lion

    OpenAIRE

    Fernández, Araceli; Paz Villanueva, María; González, Mario; Fernández, Fabiola; Latif, Fadua; Flores, Sandra Nonier; Fernández, Heriberto

    2014-01-01

    Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL) Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and inv...

  20. Invasion of South American suckermouth armoured catfishes Pterygoplichthys spp. (Loricariidae) in Kerala, India - a case study

    OpenAIRE

    A. Bijukumar; R. Smrithy; U. Sureshkumar; S. George

    2015-01-01

    This paper documents the occurrence of the exotic South American suckermouth armoured catfishes (Loricariidae) of the genus Pterygoplichthys spp. in the drainages of Thiruvananthapuram City, Kerala.  The morphological taxonomy revealed that the specimens are closely related to Pterygoplichthys disjunctivus (Weber, 1991) and P. pardalis (Castelnau, 1855), in addition to intermediary forms of unknown identity.  DNA barcoding using the mitochondrial DNA cytochrome c oxidase 1 (CO1) also failed t...

  1. Central plane of the ring current responsible for geomagnetic disturbance in the South-American region

    International Nuclear Information System (INIS)

    Kane, R.P.; Trivedi, N.B.

    1981-01-01

    Using hourly values of H, D, Z from a network of South American stations, operative during the IGY-IGC, the latitude dependence of storm effects was studied. It was found that whereas there were considerable distortions due to conductivity anomalies under the Andes, there was also evidence of latitudinal excursions of overhead current system, not only from storm to storm but even during the course of the same storm

  2. Human consumption of a vagrant South American Fur Seal Arctocephalus australis (Carnivora: Otariidae in Brazil

    Directory of Open Access Journals (Sweden)

    S. Siciliano

    2016-04-01

    Full Text Available The South American Fur Seal Arctocephalus australis is one of the most widely distributed South American otariid species. In Brazil, during austral winter months specimens of A. australis are regularly found along the Rio Grande do Sul and Santa Catarina coasts. Occasionally, vagrants have been recorded along the southeastern coast but rarely moves north of Rio de Janeiro, at 23°S. On 01 May 2015, fishermen noticed in the surf zone an unidentified large animal in Ilhéus, Bahia, northeastern Brazil. Severely wounded, it was still alive when first spotted. Numerous shark bites were observed in the rostrum and flippers, the peduncle was severely lacerated and the intestines were protruding. The specimen was identified as an adult of South American Fur Seal based on the combination of the characteristic coloration of the pelage, head shape, body size, the relatively large eye size, and mainly due to the pronounced three cusped teeth in post canines. Fishermen decided to butcher the carcass and share the meat among their companions. The present record, however, is of special concern as human consumption South American Fur Seal seems to be unusual in Brazil. Pieces of meat were shared among fishermen. In addition, small pieces of blubber were used as bait in the local shark long-line fishery. Consumption of an injured and presumably weak marine mammal carcass points to an increasing risk of contact between potentially harmful viruses, bacteria and fungi and humans. This note represents an alert to public health specialists and wildlife authorities in Brazil. It calls the urgency of an outreach campaign advertising to the potential risks of ingesting bushmeat either from land or aquatic sources. 

  3. A comparative study between South African serial killers and their American counterparts

    OpenAIRE

    2009-01-01

    M.A. This dissertation explores the similarities and differences between South African serial killers and their American counterparts. Seven male candidates, each having committed their reign of terror within the relevant time period, have been included. The candidates compared well in home environments, number of friendships, emotional maturity, abuse undergone, temperament, and anti-social behaviour. Differences were found in comparing family bonding, wealth and education. This dissertat...

  4. Social justice in climate services: Engaging African American farmers in the American South

    Directory of Open Access Journals (Sweden)

    C. Furman

    2014-01-01

    Full Text Available This article contributes to efforts to develop more inclusive climate services, understood as institutional arrangements and processes that generate and disseminate science-based climate information to promote improved preparedness to climate impacts. Discussion on equity in climate services tends to focus on the specific challenges of women and the poor in developing countries. We seek to broaden this scope by considering a farming population in the southern United States, whose particular circumstances are shaped by rural poverty as well as by racial discrimination, namely African American farmers. The research is based on a phone survey, in-depth interviews, and a workshop, and was conducted in collaboration with a civil right organization that helped the research team gain trust and entry to this community. The findings show that farmers in this study are vulnerable to drought given their relatively limited access to resources and risk management mechanisms. Climate forecasts can help these farmers move from coping strategies to deal with the effects of climate anomalies to proactive planning to anticipate and mitigate those effects. Research participants were able to identify a range of options for using such information in risk management decisions. Provision of climate services to African American farmers, however, must be consistent with existing patterns of knowledge management. These patterns are shaped by major trends stemming from the transformation of rural Southern life. Social networks of mutual assistance and knowledge transmission have been eroded by the outmigration of African American farmers from rural areas. Additionally, their relationship with public agencies is marred by a legacy of racial inequities, which makes it difficult for well-meaning projects involving the same agencies to establish legitimacy in this community. We discuss how insights from research findings and research process have guided programmatic efforts

  5. Stigma of poverty. The discursive construction of ­"South" term in Latin American countries

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    GÓMEZ QUINTERO, Juan David

    2014-05-01

    Full Text Available This article reflects a general knowledge and a macro-paradigmatic contribution of developmentalist discourses, in particular, its modernist and Eurocentric roots. In particular we analyze the artificiality of the discursive construction of certain categories that represent geopolitical stigma of poverty, such as ­Third World® or ­South® or ­underdeveloped® adopted in the field of international relations and the development cooperation. It notes that there are not metaphors opposite (North-South in its own right, the ­South® is not the opposite of the ­North®, but its negative extension, as evidenced by the imaginarium of most Latin American countries. The metaphors that stigmatize poverty are symbolic discourse used to define in a European way the identity of the winner (rich people.

  6. Hepatocyte polyploidization and its association with pathophysiological processes.

    Science.gov (United States)

    Wang, Min-Jun; Chen, Fei; Lau, Joseph T Y; Hu, Yi-Ping

    2017-05-18

    A characteristic cellular feature of the mammalian liver is the progressive polyploidization of the hepatocytes, where individual cells acquire more than two sets of chromosomes. Polyploidization results from cytokinesis failure that takes place progressively during the course of postnatal development. The proportion of polyploidy also increases with the aging process or with cellular stress such as surgical resection, toxic stimulation, metabolic overload, or oxidative damage, to involve as much as 90% of the hepatocytes in mice and 40% in humans. Hepatocyte polyploidization is generally considered an indicator of terminal differentiation and cellular senescence, and related to the dysfunction of insulin and p53/p21 signaling pathways. Interestingly, the high prevalence of hepatocyte polyploidization in the aged mouse liver can be reversed when the senescent hepatocytes are serially transplanted into young mouse livers. Here we review the current knowledge on the mechanism of hepatocytes polyploidization during postnatal growth, aging, and liver diseases. The biologic significance of polyploidization in senescent reversal, within the context of new ways to think of liver aging and liver diseases is considered.

  7. Adhesion signaling promotes protease‑driven polyploidization of glioblastoma cells.

    Science.gov (United States)

    Mercapide, Javier; Lorico, Aurelio

    2014-11-01

    An increase in ploidy (polyploidization) causes genomic instability in cancer. However, the determinants for the increased DNA content of cancer cells have not yet been fully elucidated. In the present study, we investigated whether adhesion induces polyploidization in human U87MG glioblastoma cells. For this purpose, we employed expression vectors that reported transcriptional activation by signaling networks implicated in cancer. Signaling activation induced by intercellular integrin binding elicited both extracellular signal‑regulated kinase (ERK) and Notch target transcription. Upon the prolonged activation of both ERK and Notch target transcription induced by integrin binding to adhesion protein, cell cultures accumulated polyploid cells, as determined by cell DNA content distribution analysis and the quantification of polynucleated cells. This linked the transcriptional activation induced by integrin adhesion to the increased frequency of polyploidization. Accordingly, the inhibition of signaling decreased the extent of polyploidization mediated by protease‑driven intracellular invasion. Therefore, the findings of this study indicate that integrin adhesion induces polyploidization through the stimulation of glioblastoma cell invasiveness.

  8. Molecular Tools for Exploring Polyploid Genomes in Plants

    Directory of Open Access Journals (Sweden)

    Domenico Carputo

    2012-08-01

    Full Text Available Polyploidy is a very common phenomenon in the plant kingdom, where even diploid species are often described as paleopolyploids. The polyploid condition may bring about several advantages compared to the diploid state. Polyploids often show phenotypes that are not present in their diploid progenitors or exceed the range of the contributing species. Some of these traits may play a role in heterosis or could favor adaptation to new ecological niches. Advances in genomics and sequencing technology may create unprecedented opportunities for discovering and monitoring the molecular effects of polyploidization. Through this review, we provide an overview of technologies and strategies that may allow an in-depth analysis of polyploid genomes. After introducing some basic aspects on the origin and genetics of polyploids, we highlight the main tools available for genome and gene expression analysis and summarize major findings. In the last part of this review, the implications of next generation sequencing are briefly discussed. The accumulation of knowledge on polyploid formation, maintenance, and divergence at whole-genome and subgenome levels will not only help plant biologists to understand how plants have evolved and diversified, but also assist plant breeders in designing new strategies for crop improvement.

  9. Evaluation of insulin resistance in two kinds of South American camelids: llamas and alpacas.

    Science.gov (United States)

    Araya, A V; Atwater, I; Navia, M A; Jeffs, S

    2000-10-01

    Insulin resistance was evaluated in South American camelids, llamas and alpacas, by use of the minimal model test and the insulin tolerance test. Animals were catheterized for long-term studies and tamed to minimize stress during evaluation. Results indicated a low insulin sensitivity index (SI) = 0 to 0.97, median = 0.39 x 10(-4) min/uIU x ml, about a fifth the value in other mammals and humans. The KITT was between 1.43 and 3.19 %/min, also significantly lower than that reported for humans. Glycosylated hemoglobin concentration was 6%, and HbAlc concentration was 5.5%; red blood cell lifetime, as measured by use of the 51Cr method, was 120 days, similar to the value in humans. We concluded that llamas and alpacas have naturally higher blood glucose concentration than do humans and other mammals during the glucose tolerance test. Using the same mathematical tools to evaluate glucose metabolism as those used in people, South American camelids appear to be resistant to insulin. Thus, the South American camelid may be a useful new animal model for the study of sugar metabolism and various facets of diabetes mellitus, especially protection from the deleterious effects of glycosylation.

  10. Splendid oddness: revisiting the curious trophic relationships of South American Pleistocene mammals and their abundance

    Directory of Open Access Journals (Sweden)

    RICHARD A. FARIÑA

    2014-03-01

    Full Text Available The South American Pleistocene mammal fauna includes great-sized animals that have intrigued scientists for over two centuries. Here we intend to update the knowledge on its palaeoecology and provide new evidence regarding two approaches: energetics and population density and relative abundance of fossils per taxa. To determine whether an imbalance exists, population density models were applied to several South American fossil faunas and the results compared to those that best describe the palaeoecology of African faunas. The results on the abundance study for Uruguay and the province of Buenos Aires during the Lujanian stage/age reveal that bulk-feeding ground sloths (Lestodon and Glossotherium were more represented in the first territory, while the more selective Scelidotherium and Megatherium were more abundant in the second. Although the obtained values were corrected to avoid size-related taphonomic biases, linear regressions of abundance vs. body mass plots did not fit the expected either for first or second consumers. South American Pleistocene faunas behave differently from what models suggest they should. Changes in sea level and available area could account for these differences; the possibility of a floodplain in the area then emerged could explain seasonal changes, which would modify the calculations of energetics and abundance.

  11. Potential use of the sterile insect technique against the South American fruit fly

    International Nuclear Information System (INIS)

    Ortiz, G.

    1999-01-01

    The Latin American countries have a strong interest in increasing fruit production and quality to facilitate commercialization within and outside the region. Various fruit fly control programmes in South America and their objectives and benefits are described here. Specific priorities to improve fruit fly control and eradication technologies include strengthening of quarantine, development of pre- and post-phytosanitary measures, and harmonization of the most effective and advanced technical procedures/methodologies to control fruit flies. A subregional strategy to control fruit flies in South America would promote technical co-operation among the South American countries and strengthen the activities of less advanced fruit fly programmes. Effective use can be made of local/regional infrastructure, expertise, sterile fly production and human/technical resources. In Argentina, advanced technology related to the use of medfly genetic sexing strains for SIT programmes has been successfully introduced. Joint efforts between technicians and scientists would contribute to developing new technology to control important pests in South America. (author)

  12. Meteorology of the Southern Global Plume: African and South American Fires Pollute the South Pacific

    Science.gov (United States)

    Guo, Z.; Chatfield, R. B.

    1999-01-01

    An immense global plume of CO meanders widely around the world in the Southern Hemisphere. It arises over Southern America and Africa and flows eastward. The first emissions are in tropical Brazil, and the plume circulates around the world to South America again. The plume was largely unexpected until there were aircraft studies made in NASA's Pacific Exploratory Mission - Tropics (Part A). This paper describes the meteorology of the Global Plume, as our simulation, with a synoptic model adapted to global transport, reveals it with a tracer-CO simulation. The observations and their simulation require a particular set of conditions of pollutant accumulation, cumulonimbus venting with required strengths at a narrow range of altitude. Additionally, a particular subtropical conduction region, over the Indian Ocean, Australia, and the westeRNmost South Pacific, relatively free of storms, appears to be a key part of the mechanism. These conclusions are the results of a synoptic reconstruction of the PEMT-A period, September- October, 1996.

  13. Analysis of the genetic ancestry of patients with oral clefts from South American admixed populations.

    Science.gov (United States)

    Vieira-Machado, Camilla D; de Carvalho, Flavia M; Santana da Silva, Luiz C; Dos Santos, Sidney E; Martins, Claudia; Poletta, Fernando A; Mereb, Juan C; Vieira, Alexandre R; Castilla, Eduardo E; Orioli, Iêda M

    2016-08-01

    Increased susceptibility to cleft lip, with or without cleft palate (CL±P) has been observed in South America, as related to Amerindian ancestry, using epidemiological data, uniparental markers, and blood groups. In this study, it was evaluated whether this increased risk remains when Amerindian ancestry is estimated using autosomal markers and considered in the predictive model. Ancestry was estimated through genotyping 62 insertion and deletion (INDEL) markers in sample sets of patients with CL±P, patients with cleft palate (CP), and controls, from Patagonia in southern Argentina and Belém in northern Brazil. The Amerindian ancestry in patients from Patagonia with CL±P was greater than in controls although it did not reach statistical significance. The European ancestry in patients with CL±P from Belém and in patients with CP from Belém and Patagonia was higher than in controls and statistically significant for patients with CP who were from Belém. This high contribution of European genetic ancestry among patients with CP who were from Belém has not been previously observed in American populations. Our results do not corroborate the currently accepted risks for CL±P and CP estimated by epidemiological studies in the North American populations and probably reflect the higher admixture found in South American ethnic groups when compared with the same ethnic groups from the North American populations. © 2016 Eur J Oral Sci.

  14. Explaining and improving breast cancer information acquisition among African American women in the Deep South.

    Science.gov (United States)

    Anderson-Lewis, Charkarra; Ross, Levi; Johnson, Jarrett; Hastrup, Janice L; Green, B Lee; Kohler, Connie L

    2012-06-01

    A major challenge facing contemporary cancer educators is how to optimize the dissemination of breast cancer prevention and control information to African American women in the Deep South who are believed to be cancer free. The purpose of this research was to provide insight into the breast cancer information-acquisition experiences of African American women in Alabama and Mississippi and to make recommendations on ways to better reach members of this high-risk, underserved population. Focus group methodology was used in a repeated, cross-sectional research design with 64 African American women, 35 years old or older who lived in one of four urban or rural counties in Alabama and Mississippi. Axial-coded themes emerged around sources of cancer information, patterns of information acquisition, characteristics of preferred sources, and characteristics of least-preferred sources. It is important to invest in lay health educators to optimize the dissemination of breast cancer information to African American women who are believed to be cancer free in the Deep South.

  15. Cretaceous to Recent Asymetrical Subsidence of South American and West African Conjugate Margins

    Science.gov (United States)

    Kenning, J.; Mann, P.

    2017-12-01

    Two divergent interpretations have been proposed for South American rifted-passive margins: the "mirror hypothesis" proposes that the rifted margins form symmetrically from pure shear of the lithosphere while upper-plate-lower plate models propose that the rifted margins form asymmetrically by simple shear. Models based on seismic reflection and refraction imaging and comparison of conjugate, rifted margins generally invoke a hybrid stretching process involving elements of both end member processes along with the effects of mantle plumes active during the rift and passive margin phases. We use subsidence histories of 14, 1-7 km-deep exploration wells located on South American and West African conjugate pairs now separated by the South Atlantic Ocean, applying long-term subsidence to reveal the symmetry or asymmetry of the underlying, conjugate, rift processes. Conjugate pairs characterize the rifted margin over a distance of 3500 km and include: Colorado-South Orange, Punta Del Este-North Orange, South Pelotas-Lüderitz and the North Pelotas-Walvis Basins. Of the four conjugate pairs, more rapid subsidence on the South American plate is consistently observed with greater initial rift and syn-rift subsidence rates of >60m/Ma (compared to 100 m/Ma are observed offshore South Africa between approximately 120-80 Ma, compatible with onset of the post-rift thermal sag phase. During this period the majority of burial is completed and rates remain low at Argentina/Uruguay displays more gradual subsidence throughout the Cretaceous, consistently averaging a moderate 15-30m/Ma. By the end of this stage there is a subsequent increase to 25-60 m/Ma within the last 20 Ma, interpreted to reflect lithospheric loading due to increased sedimentation rates during the Cenozoic. This increase in subsidence rate is not seen in the African conjugate section where the majority of sediments bypassed the highly aggraded Cretaceous shelf. Initially greater on the Brazilian margin compared to

  16. Family Closeness and Domestic Abuse Among Caribbean and South American Women in South Florida

    Science.gov (United States)

    Rojas, Patria; Dillon, Frank R.; Duan, Rui; De La Rosa, Mario

    2017-01-01

    This paper focuses on the importance of family member closeness as a protective factor against domestic abuse. We explore the link between long-lasting relations within the family and intra-familial violence perpetrated against women in Latino households in South Florida. We use data from an Inter-generational Transmission of Drug Use between Latina Mothers and Daughters (ITDMD) study. The study includes data on family relations and domestic abuse. We estimate a series of multivariate regressions to obtain the probability of abuse against women, the types of abuse inflicted and the relationship with the abusers. Our results indicate that among abused women, the effects of long-lasting relations within the family differ depending on the type of relationship between the abuser and the victim and the degree of closeness the victim feels towards other family members. Given these findings, there is a need to further study family relations and abuse in Latino households. PMID:29033494

  17. Latin American social medicine across borders: South-South cooperation and the making of health solidarity.

    Science.gov (United States)

    Birn, Anne-Emanuelle; Muntaner, Carles

    2018-02-22

    Latin American social medicine efforts are typically understood as national endeavours, involving health workers, policymakers, academics, social movements, unions, and left-wing political parties, among other domestic actors. But Latin America's social medicine trajectory has also encompassed considerable between-country solidarity, building on early twentieth century interchanges among a range of players who shared approaches for improving living and working conditions and instituting protective social policies. Since the 1960s, Cuba's country-to-country solidarity has stood out, comprising medic exchanges, training, and other forms of support for the health and social struggles of oppressed peoples throughout Latin America and around the world, recently via Misión Barrio Adentro in Venezuela. These efforts strive for social justice-oriented health cooperation based on horizontal power relations, shared political values, a commitment to social and economic redistribution, bona fide equity, and an understanding of the societal determination of health that includes, but goes well beyond, public health and medical care. With Latin America's left-wing surge now receding, this article traces the provenance, dynamics, impact, challenges, and legacy of health solidarity across Latin American borders and its prospects for continuity.

  18. Native South American genetic structure and prehistory inferred from hierarchical modeling of mtDNA.

    Science.gov (United States)

    Lewis, Cecil M; Long, Jeffrey C

    2008-03-01

    Genetic diversity in Native South Americans forms a complex pattern at both the continental and local levels. In comparing the West to the East, there is more variation within groups and smaller genetic distances between groups. From this pattern, researchers have proposed that there is more variation in the West and that a larger, more genetically diverse, founding population entered the West than the East. Here, we question this characterization of South American genetic variation and its interpretation. Our concern arises because others have inferred regional variation from the mean variation within local populations without taking into account the variation among local populations within the same region. This failure produces a biased view of the actual variation in the East. In this study, we analyze the mitochondrial DNA sequence between positions 16040 and 16322 of the Cambridge reference sequence. Our sample represents a total of 886 people from 27 indigenous populations from South (22), Central (3), and North America (2). The basic unit of our analyses is nucleotide identity by descent, which is easily modeled and proportional to nucleotide diversity. We use a forward modeling strategy to fit a series of nested models to identity by descent within and between all pairs of local populations. This method provides estimates of identity by descent at different levels of population hierarchy without assuming homogeneity within populations, regions, or continents. Our main discovery is that Eastern South America harbors more genetic variation than has been recognized. We find no evidence that there is increased identity by descent in the East relative to the total for South America. By contrast, we discovered that populations in the Western region, as a group, harbor more identity by descent than has been previously recognized, despite the fact that average identity by descent within groups is lower. In this light, there is no need to postulate separate founding

  19. U.S. foreign policy, the south american integration, and the case of the military bases in Colombia

    OpenAIRE

    Iglesias Cavicchioli, Manuel

    2010-01-01

    This article analyzes the nature of the conflict generated in South America by the adoption of the new military agreement between the U.S. and Colombia. The article will evaluate the political and the geostrategic implications of this agreement, especially its repercussions for the regional integration process of South America. It will also analyze the stances of the local actors in order to consider prospective scenarios, and will assess the U.S. approach to South American int...

  20. E2F8 is essential for polyploidization in mammalian cells

    NARCIS (Netherlands)

    Pandit, Shusil K.; Westendorp, Bart; Nantasanti, Sathidpak; van Liere, Elsbeth; Tooten, Peter C. J.; Cornelissen, Peter W. A.; Toussaint, Mathilda J. M.; Lamers, Wouter H.; de Bruin, Alain

    2012-01-01

    Polyploidization is observed in all mammalian species and is a characteristic feature of hepatocytes, but its molecular mechanism and biological significance are unknown. Hepatocyte polyploidization in rodents occurs through incomplete cytokinesis, starts after weaning and increases with age. Here,

  1. Grandparent caregiving among rural African Americans in a community in the American South: challenges to health and wellbeing.

    Science.gov (United States)

    Clottey, Emmanuel N; Scott, Alison J; Alfonso, Moya L

    2015-01-01

    An increasing number of grandparents in rural USA are serving as primary caregivers for their grandchildren because of parental incarceration, addiction, joblessness, or illness. Low-income, African American women from the South are overrepresented in this growing population. There is a paucity of research exploring the challenges faced by rural grandparent caregivers, and past studies have not explicitly addressed the potential consequences of rural grandparent caregiving for health. The purpose of this qualitative study was to explore grandparent caregiving among rural, low-income, African American grandmothers in a community in the American South, and to identify challenges to health that arose in that context. McLeroy's social ecological model (SEM) was used to examine these challenges at multiple levels of influence. This qualitative interview-based study was conducted in a high-poverty community in rural Georgia. In-depth interviews were conducted with African American grandparent caregivers and key informants from local community-based organizations. A key informant assisted in identifying initial interview participants, and then snowball sampling was used to recruit additional participants. Interview questions were grouped under five domains (intrapersonal, interpersonal, community, organizational, and policy), according to the levels of the SEM. Iterative content analysis of interview transcripts was utilized. Transcripts were coded to identify text segments related to each domain of the SEM, which were grouped together for analysis by domain. Reflexive memo-writing aided in development of themes, and data quality was assessed using Lincoln and Guba's trustworthiness criteria. Rural African American grandparent caregivers faced a range of challenges to health. Direct physical challenges included chronic pain that interfered with sleep and daily functioning, mobility issues exacerbated by child care, and the pressure of managing their own medical conditions

  2. Five nuclear loci resolve the polyploid history of switchgrass (Panicum virgatum L. and relatives.

    Directory of Open Access Journals (Sweden)

    Jimmy K Triplett

    Full Text Available Polyploidy poses challenges for phylogenetic reconstruction because of the need to identify and distinguish between homoeologous loci. This can be addressed by use of low copy nuclear markers. Panicum s.s. is a genus of about 100 species in the grass tribe Paniceae, subfamily Panicoideae, and is divided into five sections. Many of the species are known to be polyploids. The most well-known of the Panicum polyploids are switchgrass (Panicum virgatum and common or Proso millet (P. miliaceum. Switchgrass is in section Virgata, along with P. tricholaenoides, P. amarum, and P. amarulum, whereas P. miliaceum is in sect. Panicum. We have generated sequence data from five low copy nuclear loci and two chloroplast loci and have clarified the origin of P. virgatum. We find that all members of sects. Virgata and Urvilleana are the result of diversification after a single allopolyploidy event. The closest diploid relatives of switchgrass are in sect. Rudgeana, native to Central and South America. Within sections Virgata and Urvilleana, P. tricholaenoides is sister to the remaining species. Panicum racemosum and P. urvilleanum form a clade, which may be sister to P. chloroleucum. Panicum amarum, P. amarulum, and the lowland and upland ecotypes of P. virgatum together form a clade, within which relationships are complex. Hexaploid and octoploid plants are likely allopolyploids, with P. amarum and P. amarulum sharing genomes with P. virgatum. Octoploid P. virgatum plants are formed via hybridization between disparate tetraploids. We show that polyploidy precedes diversification in a complex set of polyploids; our data thus suggest that polyploidy could provide the raw material for diversification. In addition, we show two rounds of allopolyploidization in the ancestry of switchgrass, and identify additional species that may be part of its broader gene pool. This may be relevant for development of the crop for biofuels.

  3. A bayesian approach to genome/linguistic relationships in native South Americans.

    Science.gov (United States)

    Amorim, Carlos Eduardo Guerra; Bisso-Machado, Rafael; Ramallo, Virginia; Bortolini, Maria Cátira; Bonatto, Sandro Luis; Salzano, Francisco Mauro; Hünemeier, Tábita

    2013-01-01

    The relationship between the evolution of genes and languages has been studied for over three decades. These studies rely on the assumption that languages, as many other cultural traits, evolve in a gene-like manner, accumulating heritable diversity through time and being subjected to evolutionary mechanisms of change. In the present work we used genetic data to evaluate South American linguistic classifications. We compared discordant models of language classifications to the current Native American genome-wide variation using realistic demographic models analyzed under an Approximate Bayesian Computation (ABC) framework. Data on 381 STRs spread along the autosomes were gathered from the literature for populations representing the five main South Amerindian linguistic groups: Andean, Arawakan, Chibchan-Paezan, Macro-Jê, and Tupí. The results indicated a higher posterior probability for the classification proposed by J.H. Greenberg in 1987, although L. Campbell's 1997 classification cannot be ruled out. Based on Greenberg's classification, it was possible to date the time of Tupí-Arawakan divergence (2.8 kya), and the time of emergence of the structure between present day major language groups in South America (3.1 kya).

  4. Mitochondrial control region haplotypes of the South American sea lion Otaria flavescens (Shaw, 1800).

    Science.gov (United States)

    Artico, L O; Bianchini, A; Grubel, K S; Monteiro, D S; Estima, S C; Oliveira, L R de; Bonatto, S L; Marins, L F

    2010-09-01

    The South American sea lion, Otaria flavescens, is widely distributed along the Pacific and Atlantic coasts of South America. However, along the Brazilian coast, there are only two nonbreeding sites for the species (Refúgio de Vida Silvestre da Ilha dos Lobos and Refúgio de Vida Silvestre do Molhe Leste da Barra do Rio Grande), both in Southern Brazil. In this region, the species is continuously under the effect of anthropic activities, mainly those related to environmental contamination with organic and inorganic chemicals and fishery interactions. This paper reports, for the first time, the genetic diversity of O. flavescens found along the Southern Brazilian coast. A 287-bp fragment of the mitochondrial DNA control region (D-loop) was analyzed. Seven novel haplotypes were found in 56 individuals (OFA1-OFA7), with OFA1 being the most frequent (47.54%). Nucleotide diversity was moderate (π = 0.62%) and haplotype diversity was relatively low (67%). Furthermore, the median joining network analysis indicated that Brazilian haplotypes formed a reciprocal monophyletic clade when compared to the haplotypes from the Peruvian population on the Pacific coast. These two populations do not share haplotypes and may have become isolated some time back. Further genetic studies covering the entire species distribution are necessary to better understand the biological implications of the results reported here for the management and conservation of South American sea lions.

  5. Mitochondrial control region haplotypes of the South American sea lion Otaria flavescens (Shaw, 1800

    Directory of Open Access Journals (Sweden)

    L.O. Artico

    2010-09-01

    Full Text Available The South American sea lion, Otaria flavescens, is widely distributed along the Pacific and Atlantic coasts of South America. However, along the Brazilian coast, there are only two nonbreeding sites for the species (Refúgio de Vida Silvestre da Ilha dos Lobos and Refúgio de Vida Silvestre do Molhe Leste da Barra do Rio Grande, both in Southern Brazil. In this region, the species is continuously under the effect of anthropic activities, mainly those related to environmental contamination with organic and inorganic chemicals and fishery interactions. This paper reports, for the first time, the genetic diversity of O. flavescens found along the Southern Brazilian coast. A 287-bp fragment of the mitochondrial DNA control region (D-loop was analyzed. Seven novel haplotypes were found in 56 individuals (OFA1-OFA7, with OFA1 being the most frequent (47.54%. Nucleotide diversity was moderate (π = 0.62% and haplotype diversity was relatively low (67%. Furthermore, the median joining network analysis indicated that Brazilian haplotypes formed a reciprocal monophyletic clade when compared to the haplotypes from the Peruvian population on the Pacific coast. These two populations do not share haplotypes and may have become isolated some time back. Further genetic studies covering the entire species distribution are necessary to better understand the biological implications of the results reported here for the management and conservation of South American sea lions.

  6. Climate change and American Bullfrog invasion: what could we expect in South America?

    Directory of Open Access Journals (Sweden)

    Javier Nori

    Full Text Available BACKGROUND: Biological invasion and climate change pose challenges to biodiversity conservation in the 21(st century. Invasive species modify ecosystem structure and functioning and climatic changes are likely to produce invasive species' range shifts pushing some populations into protected areas. The American Bullfrog (Lithobates catesbeianus is one of the hundred worst invasive species in the world. Native from the southeast of USA, it has colonized more than 75% of South America where it has been reported as a highly effective predator, competitor and vector of amphibian diseases. METHODOLOGY/PRINCIPAL FINDINGS: We modeled the potential distribution of the bullfrog in its native range based on different climate models and green-house gases emission scenarios, and projected the results onto South America for the years of 2050 and 2080. We also overlaid projected models onto the South American network of protected areas. Our results indicate a slight decrease in potential suitable area for bullfrog invasion, although protected areas will become more climatically suitable. Therefore, invasion of these sites is forecasted. CONCLUSION/SIGNIFICANCE: We provide new evidence supporting the vulnerability of the Atlantic Forest Biodiversity Hotspot to bullfrog invasion and call attention to optimal future climatic conditions of the Andean-Patagonian forest, eastern Paraguay, and northwestern Bolivia, where invasive populations have not been found yet. We recommend several management and policy strategies to control bullfrog invasion and argue that these would be possible if based on appropriate articulation among government agencies, NGOs, research institutions and civil society.

  7. Arthroscopic approach and intraarticular anatomy of the stifle in South American camelids.

    Science.gov (United States)

    Pentecost, Rebecca L; Niehaus, Andrew J; Santschi, Elizabeth

    2012-05-01

    To describe a cranial arthroscopic approach to the stifle of South American camelids and to report our clinical experience with camelid stifle arthroscopy. Experimental study and retrospective case series. (1) Cadaveric alpaca hindlimbs (n = 18; 9 alpacas); (2) 1 alpaca and 1 llama Polymethylmethacrylate joint casts (n = 2) were made to define stifle joint dimensions. Cadaveric stifle joints (n = 16) were evaluated arthroscopically to determine arthroscopic portal locations, describe the intraarticular anatomy, and report potential complications. An alpaca and a llama with stifle joint disease had diagnostic arthroscopy. Successful entry into the stifle joint was achieved in 16 cadaver limbs. Observed structures were: the suprapatellar pouch, articular surface of the patella, femoral trochlear ridges and groove, cranial aspect of the femoral condyles (n = 16); distal aspect of the cranial and proximal aspect of the caudal cruciate ligaments (14); and cranial aspects of the medial and lateral menisci (11), and cranial meniscotibial and intermeniscal ligaments (8). Stifle arthroscopy allowed for joint evaluation and removal of osteochondral fragments in 1 alpaca and 1 llama with naturally occurring stifle disease. Complications of cadaver or live procedures included minor cartilage scoring (3 stifles) and subcutaneous periarticular fluid accumulation (8 stifles). Arthroscopy provides a safe approach for diagnosis and treatment of stifle lesions in South American camelids. Copyright 2012 by The American College of Veterinary Surgeons.

  8. The role of SST on the South American atmospheric circulation during January, February and March 2001

    Science.gov (United States)

    Drumond, Anita Rodrigues De Moraes; Ambrizzi, Tércio

    2005-06-01

    Precipitation deficits were observed over southeastern, northeastern and Central Brazil during the 2001 Austral Summer. They contributed to the worsening of the energy crisis that was occurring in the country. A low-level anomalous anticyclonic circulation observed over eastern Brazil enhanced the deviation of moisture transport that usually occurs from the Amazon Basin to southeastern Brazil and inhibited the occurrence of South Atlantic Convergence Zone events in that period. However, an anomalous low-level northerly moisture flux was observed over the La Plata Basin, and positive precipitation anomalies occurred over Bolivia, Paraguay, northeastern Argentina and southern Brazil. Using the ensemble technique, a numerical study was carried out to investigate the role of different sea surface temperature (SST) forcings observed over this anomalous South American atmospheric circulation. Reynolds SST monthly means were used as boundary conditions to study the influence of South Atlantic, South Indian, South Pacific and Equatorial Pacific oceans. The simulations were run from September 2000 to April 2001 using the Community Climate Model version 3.6 General Circulation Model. Ten integrations using different initial conditions were done to each experiment. Numerical experiments suggested that the combined influence of South Pacific and Equatorial Pacific oceans could be responsible for the drought observed over Central Brazil. These experiments simulated the low-level anticyclonic anomaly observed over eastern Brazil. However, both experiments have poorly reproduced the intensity of the anomalous low-level northerly moisture flux observed over the La Plata Basin. Therefore, the intensity of the simulated precipitation anomalies over the subtropical regions was much weaker than observed.

  9. Genetic diversity of neotropical Myotis (chiroptera: vespertilionidae with an emphasis on South American species.

    Directory of Open Access Journals (Sweden)

    Roxanne J Larsen

    Full Text Available BACKGROUND: Cryptic morphological variation in the Chiropteran genus Myotis limits the understanding of species boundaries and species richness within the genus. Several authors have suggested that it is likely there are unrecognized species-level lineages of Myotis in the Neotropics. This study provides an assessment of the diversity in New World Myotis by analyzing cytochrome-b gene variation from an expansive sample ranging throughout North, Central, and South America. We provide baseline genetic data for researchers investigating phylogeographic and phylogenetic patterns of Myotis in these regions, with an emphasis on South America. METHODOLOGY AND PRINCIPAL FINDINGS: Cytochrome-b sequences were generated and phylogenetically analyzed from 215 specimens, providing DNA sequence data for the most species of New World Myotis to date. Based on genetic data in our sample, and on comparisons with available DNA sequence data from GenBank, we estimate the number of species-level genetic lineages in South America alone to be at least 18, rather than the 15 species currently recognized. CONCLUSIONS: Our findings provide evidence that the perception of lower species richness in South American Myotis is largely due to a combination of cryptic morphological variation and insufficient sampling coverage in genetic-based systematic studies. A more accurate assessment of the level of diversity and species richness in New World Myotis is not only helpful for delimiting species boundaries, but also for understanding evolutionary processes within this globally distributed bat genus.

  10. Tectonothermal events of southeastern Brazil: Implications for consolidation of the South American platform

    International Nuclear Information System (INIS)

    Hackspacher, P.C.; Fetter, A.H; Dantas, E.L; Hadler Neto, J.C; Ribeiro, L.F.B; Tello, C.E.S

    2001-01-01

    The tectonothermal history of the South American Platform and it consolidation have to be analyzed considering different tectonic and stabilization stages. For that propose we have studied the Precambrian basement southwest of the city of Sao Paulo, which was consolidated and deformed during the Brasiliano Orogeny and later affected by Phanerozoic tectonics. Geological data from a northwest/southeast transect between Sao Roque and Jundiai - SP, were obtained through U/Pb, K/Ar and Ar/Ar mineral and whole rock studies. Metamorphic PT values, relation of brittle-ductile zone of felsic crustal rocks and fission track ages were also obtained. Such data were plotted on a temperature-time plot representing a preliminary overview of the geological evolution of this part of the South American platform. Recently dated highly deformed metaplutons from the Ribeira Belt suggest that convergence that preceded collision was underway by around 650 Ma. Low-grade (rarely reaching 4000 o C) metasediments and metavolcanics of the Sao Roque Group, interpreted to be a backarc basin that formed during active Brasiliano collision, yield a crystallization age of 627 Ma (Hackspacher et al., 2000). Syn-collisional granitoids with U/Pb zircon and monazite ages of 625 Ma (Janasi, 1999) provide more constraints on the timing of active collision. Temperatures of these calc-alkaline rocks can be considered around 650 o C. U/Pb zircon and monazite ages between 610 and 595 Ma obtained igneous bodies associated with transpressional tectonics place age constraints on the transition to a transpressional regime, with crystallization temperature around 580 o C. Related strike-slip shear zones in brittle-ductile transition, present K-Ar ages on biotite and hornblende between 600 and 580 Ma. The temperature interval for these greenschist grade shear zones is estimated between 450 and 300 o C. Apatite Fission Track Analysis (AFTA) near the Jundiuvira Shear Zone present a corrected Fission Track Age of 477

  11. Polyploid response of Artemisia annua L. to colchicine treatment

    Science.gov (United States)

    Yunus, A.; Parjanto; Samanhudi; Hikam, M. P.; Widyastuti, Y.

    2018-03-01

    Artemisia (Artemisia annua) is a a medicinal herb originated from Asia, its contains Artemisinin for malaria (caused by Plasmodium falciparum) treatment. Artemisinin content in A. annua are relatively low, ranging from 0.01% -0.5%. In order to increase the Artemisinin content, polyploid induction could be one effort to be done. For that, this experiment aims to examine the effect of colchicine on morphological characteristics and the induction of polyploidization in Artemisia plants. Polyploid induction on Artemisia annua L. seeds was performed by soaking the Artemisia seeds in colchicine (0%, 0,05%, 0,1% and 0,2%; concentration based) for 2 hours. The experimental design was Completely Randomized Design, one factor, 4 colchicine treatments and in each treatment 7 replicate. The results showed that polyploid occur in plants treated with 0.05% colchicine concentration and its morphological characteristic are 89.4 cm height, 30 branches, 15.9 CCI chlorophyll content, 0.78 cm stem diameter, and chromosome number 2n = 27. In the stomata density of polyploid plants (treated by 0.05% colchicine) was 130 number/mm2 with stomata diameter of 22.8 μm.

  12. Induced polyploidization in Brassica campestris L. (Brassicaceae).

    Science.gov (United States)

    Kumar, G; Dwivedi, K

    2014-01-01

    Present experimental design has been made up to obtain crop with higher ploidy level via synthetic polyploidization. Since ploidy manipulation is generally associated with the obtainment of some increased enviable traits of the crop and also provides them greater adaptability to unfavorable or harsh circumstances as compared to its diploids counterparts. Thus, herein present research autotetraploids of Brassica campestris L. have been lucratively achieved by the application of colchicine. Two methods of treatment were utilized i.e. seed treatment and seedling treatment. No polyploidy could be obtained through seed treatment while seedling treatment responded well towards polyploidy. However, the status of autotetraploidy has been confirmed by cytomorphological investigations of treated plants as against its diploids counterparts. For the purpose, morphological parameters such as increased stomata size, pollen diameter, flower size, reproductive organs whereas reduction in plant height, leaf length, leaf breadth, stomata frequency, number of flowers/inflorescence etc. were appraised. Further, cytological observations were made that had clearly revealed the doubling of genome in the autotetraploids as compared to diploids. Meanwhile, pollen fertility and size of pollen grains were evaluated as well.

  13. South American regional ionospheric maps computed by GESA: A pilot service in the framework of SIRGAS

    Science.gov (United States)

    Brunini, C.; Meza, A.; Gende, M.; Azpilicueta, F.

    2008-08-01

    SIRGAS (Geocentric Reference Frame for the Americas) is an international enterprise of the geodetic community that aims to realize the Terrestrial Reference Frame in the America's countries. In order to fulfill this commitment, SIRGAS manages a network of continuously operational GNSS receivers totalling around one hundred sites in the Caribbean, Central, and South American region. Although the network was not planed for ionospheric studies, its potential to be used for such a purpose was recently recognized and SIRGAS started a pilot experiment devoted to establish a regular service for computing and releasing regional vertical TEC (vTEC) maps based on GNSS data. Since July, 2005, the GESA (Geodesia Espacial y Aeronomía) laboratory belonging to the Facultad de Ciencias Astronómicas y Geofísicas of the Universidad Nacional de La Plata computes hourly maps of vertical Total Electron Content (vTEC) in the framework of the SIRGAS pilot experiment. These maps exploit all the GNSS data available in the South American region and are computed with the LPIM (La Plata Ionospheric Model). LPIM implements a de-biasing procedure that improves data calibration in relation to other procedures commonly used for such purposes. After calibration, slant TEC measurements are converted to vertical and mapped using local-time and modip latitude. The use of modip latitude smoothed the spatial variability of vTEC, especially in the South American low latitude region and hence allows for a better vTEC interpolation. This contribution summarizes the results obtained by GESA in the framework of the SIRGAS pilot experiment.

  14. Experimental infection of two South American reservoirs with four distinct strains of Trypanosoma cruzi

    Science.gov (United States)

    Roellig, Dawn M.; McMillan, Katherine; Ellis, Angela E.; Vandeberg, John L.; Champagne, Donald E.; Yabsley, Michael J.

    2010-01-01

    SUMMARY Trypanosoma cruzi (Tc), the causative agent of Chagas disease, is a diverse species with 2 primary genotypes, TcI and TcII, with TcII further subdivided into 5 subtypes (IIa–e). This study evaluated infection dynamics of 4 genetically and geographically diverse T. cruzi strains in 2 South American reservoirs, degus (Octodon degus) and grey short-tailed opossums (Monodelphis domestica). Based on prior suggestions of a genotype-host association, we hypothesized that degus (placental) would more readily become infected with TcII strains while short-tailed opossums (marsupial) would be a more competent reservoir for a TcI strain. Individuals (n = 3) of each species were intraperitoneally inoculated with T. cruzi trypomastigotes of TcIIa [North America (NA)-raccoon (Procyon lotor) origin], TcI [NA-Virginia opossum (Didelphis virginiana)], TcIIb [South America (SA)-human], TcIIe (SA-Triatoma infestans), or both TcI and TcIIa. Parasitaemias in experimentally infected degus peaked earlier (7–14 days post-inoculation (p.i.)) compared with short-tailed opossums (21–84 days p.i.). Additionally, peak parasitaemias were higher in degus; however, the duration of detectable parasitaemias for all strains, except TcIIa, was greater in short-tailed opossums. Infections established in both host species with all genotypes, except for TcIIa, which did not establish a detectable infection in short-tailed opossums. These results indicate that both South American reservoirs support infections with these isolates from North and South America; however, infection dynamics differed with host and parasite strain. PMID:20128943

  15. Uncinaria hamiltoni (Nematoda: Ancylostomatidae) in South American Sea Lions, Otaria flavescens, From Northern Patagonia, Argentina

    OpenAIRE

    Berón-Vera, B.; Crespo, Enrique Alberto; Raga Esteve, Juan Antonio; Pedraza, S. N.

    2004-01-01

    Thirty-one South American sea lion pups (Otaria flavescens) found dead in Punta León, Argentina, during the summer of 2002, were examined for hookworms (Uncinaria hamiltoni). Parasite parameters were analyzed in 2 locations of the rookery, i.e., a traditional, well-structured breeding area and an expanding area with juveniles and a lax social structure. Prevalence of hookworms was 50% in both localities, and no difference was observed in prevalence between pup sexes (P > 0.05). Hookworms were...

  16. Highly Structured Duets in the Song of the South American Hornero

    Science.gov (United States)

    Laje, Rodrigo; Mindlin, Gabriel B.

    2003-12-01

    The South American Hornero (Furnarius rufus) is a suboscine bird widely known for its mud-made, oven-looking nest. Beyond their architectural skills, the male and female Horneros sing in highly structured duets. The analysis of field recordings reported in this work reveals that as the male increases the note production rate the female responds by switching to different locking states: the ones predicted by the theory of nonlinear forced oscillators. This gives the duet a most appealing rhythm, and unveils the nonlinear nature of the underlying brain activity needed to generate the song.

  17. Natural Infection of the South American Tapir ( Tapirus terrestris ) by Theileria equi.

    Science.gov (United States)

    Da Silveira, Alexandre Welzel; De Oliveira, Gustavo Gomes; Menezes Santos, Leandro; da Silva Azuaga, Lucas Bezerra; Macedo Coutinho, Claudia Regina; Echeverria, Jessica Teles; Antunes, Tamires Ramborger; do Nascimento Ramos, Carlos Alberto; Izabel de Souza, Alda

    2017-04-01

    Theileria equi is a tick-borne piroplasm considered endemic in equines in Brazil. The cohabitation of domestic and wild animals in areas of extensive cattle breeding favors the close contact between different species and the sharing of vectors and, consequently, pathogens. We report the natural infection of a young South American tapir ( Tapirus terrestris ) by T. equi in Mato Grosso do Sul, Brazil. Although it was not possible to associate the clinical and hematologic status of the animal with the infection by the protozoan parasite, our report represents an alert on the sharing of pathogens between domestic and wild animals.

  18. Megakaryocyte Polyploidization and Proplatelet Formation in Low-Attachment Conditions.

    Science.gov (United States)

    Schlinker, Alaina C; Duncan, Mark T; DeLuca, Teresa A; Whitehead, David C; Miller, William M

    2016-07-15

    In vitro -derived platelets (PLTs), which could provide an alternative source of PLTs for patient transfusions, are formed from polyploid megakaryocytes (MKs) that extend long cytoplasmic projections, termed proplatelets (proPLTs). In this study, we compared polyploidization and proPLT formation (PPF) of MKs cultured on surfaces that either promote or inhibit protein adsorption and subsequent cell adhesion. A megakaryoblastic cell line exhibited increased polyploidization and arrested PPF on a low-attachment surface. Primary human MKs also showed low levels of PPF on the same surface, but no difference in ploidy. Importantly, both cell types exhibited accelerated PPF after transfer to a surface that supports attachment, suggesting that pre-culture on a non-adhesive surface may facilitate synchronization of PPF and PLT generation in culture.

  19. Polyploidization of glia in neural development links tissue growth to blood-brain barrier integrity.

    Science.gov (United States)

    Unhavaithaya, Yingdee; Orr-Weaver, Terry L

    2012-01-01

    Proper development requires coordination in growth of the cell types composing an organ. Many plant and animal cells are polyploid, but how these polyploid tissues contribute to organ growth is not well understood. We found the Drosophila melanogaster subperineurial glia (SPG) to be polyploid, and ploidy is coordinated with brain mass. Inhibition of SPG polyploidy caused rupture of the septate junctions necessary for the blood-brain barrier. Thus, the increased SPG cell size resulting from polyploidization is required to maintain the SPG envelope surrounding the growing brain. Polyploidization likely is a conserved strategy to coordinate tissue growth during organogenesis, with potential vertebrate examples.

  20. PARTICULATE ORGANIC CARBON, cloud amount/frequency and other data from COLUMBUS ISELIN in the North American Coastline-South and South Atlantic Ocean from 1990-05-23 to 1990-06-13 (NODC Accession 9100150)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data was collected from R/V COLUMBUS ISELIN in South Atlantic Ocean and North American Coast line-South during the Amazon Shelf Sediment Study (AMASSEDS) between May...

  1. Liver physiological polyploidization: MicroRNA-122 a key regulator.

    Science.gov (United States)

    Celton-Morizur, Séverine; Desdouets, Chantal

    2017-03-01

    Polyploidy is defined as an increase in genome DNA content and is observed in all mammalian species. Polyploidy is a common characteristic of hepatocytes. Polyploidization occurs mainly during liver development, but also in adults with increasing age or due to cellular stress. During liver development, hepatocytes polyploidization occurs through cytokinesis failure leading to the genesis of binucleate hepatocytes. Recently, Hsu et al. demonstrated that miR-122 is a key regulator of hepatic binucleation. In fact, during liver development, miR-122 directly antagonizes procytokinesis targets and thus induces cytokinesis failure leading to the genesis of binucleate hepatocytes. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  2. Factors Associated with Toothache among African American Adolescents Living in Rural South Carolina

    Science.gov (United States)

    Wiegand, Ryan E.; Hill, Elizabeth G.; Magruder, Kathryn M.; Slate, Elizabeth H.; Salinas, Carlos F.; London, Steven D.

    2012-01-01

    Objective The aim of this study is to explore behavioral factors associated with toothache among African American adolescents living in rural South Carolina. Methods Using a self-administered questionnaire, data were collected on toothache experience in the past 12 months, oral hygiene behavior, dental care utilization, and cariogenic snack and non-diet soft drink consumption in a convenience sample of 156 African American adolescents aged 10-18 years old living in rural South Carolina. Univariable and multivariable logistic regression analyses were used to assess the associations between reported toothache experience and socio-demographic variables, oral health behavior, and snack consumption. Results Thirty-four percent of adolescents reported having toothache in the past 12 months. In univariable modeling, age, dental visit in the last two years, quantity and frequency of cariogenic snack consumption, and quantity of non-diet soft drink consumption were each significantly associated with experiencing toothache in the past 12 months (all p-values cariogenic snacks, and number of cans of non-diet soft drink consumed during the weekend significantly increased the odds of experiencing toothache in the past 12 months (all p-values ≤ 0.01). Conclusion Findings indicate age, frequent consumption of cariogenic snacks and number of cans of non-diet soft drinks are related to toothache in this group. Public policy implications related to selling cariogenic snacks and soft drink that targeting children and adolescents especially those from low income families are discussed. PMID:22085328

  3. Disparities in Birth Weight and Gestational Age by Ethnic Ancestry in South American countries

    Science.gov (United States)

    Wehby, George L.; Gili, Juan A.; Pawluk, Mariela; Castilla, Eduardo E.; López-Camelo, Jorge S.

    2015-01-01

    Objective We examine disparities in birth weight and gestational age by ethnic ancestry in 2000–2011 in eight South American countries. Methods The sample included 60480 singleton live-births. Regression models were estimated to evaluate differences in birth outcomes by ethnic ancestry controlling for time trends. Results Significant disparities were found in seven countries. In four countries – Brazil, Ecuador, Uruguay, and Venezuela – we found significant disparities in both low birth weight and preterm birth. Disparities in preterm birth alone were observed in Argentina, Bolivia, and Colombia. Several differences in continuous birth weight, gestational age, and fetal growth rate were also observed. There were no systematic patterns of disparities between the evaluated ethnic ancestry groups across the study countries, in that no racial/ethnic group consistently had the best or worst outcomes in all countries. Conclusions Racial/ethnic disparities in infant health are common in several South American countries. Differences across countries suggest that racial/ethnic disparities are driven by social and economic mechanisms. Researchers and policymakers should acknowledge these disparities and develop research and policy programs to effectively target them. PMID:25542227

  4. IMPROVING MASS REARING TECHNOLOGY FOR SOUTH AMERICAN FRUIT FLY (DIPTERA:TEPHRITIDAE

    Directory of Open Access Journals (Sweden)

    Raimundo Braga Sobrinho

    2006-01-01

    Full Text Available Studies on availability of suitable and economic diets for adults and larvae of the South American fruit fly Anastrepha fraterculus (Wiedemann, 1830 were carried out at the Entomology Unit of the FAO/IAEA Agriculture and Biotechnology Laboratories in Seibersdorf, Austria with the aim to find the best diets to fit in a large scale mass rearing production. The best diet for adult was the combination of Hydrolysate Corn Protein + Yeast Hydrolysate Enzymatic + Sugar (3:1:3. This diet resulted in the highest numbers of egg/female/day, spermatozoid in the spermathecae, percentages of egg hatch, the lowest mortality rate of adults and the highest average mating duration compared with the standard adult diet based on Yeast Hydrolysate Enzymatic + Sugar (1:3. Among eleven larval diets tested, diets based on sugarcane and sugarbeet bagases plus 7% brewer yeast, 8% sugar, 0.2% sodium benzoate, 0.8% of hydrochloric acid and 60% water (adjusted, yielded the highest percentages of egg hatching, pupal recovery, pupal weight and adult emergence. There was no statistical difference with the standard larval diet based on wheat germ 3%, corncob 15%, corn flower 8%, brewer yeast 6%, sugar 8%, sodium benzoate 0.23%, hydrochloric acid 0.63%, nipagin 0.14% and water 59% (adjusted. The significant performance of these adult and larval diets open discussion for future researches on improvement of rearing techniques required for the establishment of sterile insect technique (SIT program focused on the South American fruit fly.

  5. Brightness of venous blood in South American camelids: implications for jugular catheterization.

    Science.gov (United States)

    Grint, Nicola; Dugdale, Alexandra

    2009-01-01

    To compare the brightness of South American camelid venous blood to that of Equidae. Prospective clinical evaluation. Twelve South American camelids (eight llamas, four alpacas), eight horses and ponies (control group). Appropriately sized catheters were placed in the jugular vein of each animal under local anaesthesia. The blood spilt before the catheter was capped was caught on a white tile. A sample of blood was drawn for blood-gas analysis. The brightness of the blood (both on the tile and in the syringe) was matched to a colour chart (1 = darkest red, 8 = brightest red) by a single observer under bright light conditions. Packed cell volume (PCV) and partial pressure of oxygen (PvO(2)) in the blood were also measured on the syringe blood. Normally distributed data were compared using a two tailed t-test, and non-normally distributed data were compared using a Mann-Whitney U-test. Significance was set at p Camelid venous blood was significantly brighter red than that of horses and ponies both on the white tile (p = 0.0003) and in the syringe (p = 0.0001). PCV was significantly lower in camelids (32 +/- 4%) compared with horses (37 +/- 5%). Partial pressure of oxygen values were similar between groups. Jugular venous blood in alpacas and llamas is significantly brighter red than that of horses. Colour should not be used as a sole determinant of venous or arterial catheterization in this species.

  6. Anthropozoonotic Endoparasites in Free-Ranging “Urban” South American Sea Lions (Otaria flavescens

    Directory of Open Access Journals (Sweden)

    Carlos Hermosilla

    2016-01-01

    Full Text Available The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging “urban” colony of South American sea lions (Otaria flavescens living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF technique, carbol fuchsin-stained faecal smears and Giardia/Cryptosporidium coproantigen ELISAs, revealed infections with 8 different parasites belonging to protozoan and metazoan taxa with some of them bearing anthropozoonotic potential. Thus, five of these parasites were zoonotic (Diphyllobothriidae gen. sp., Anisakidae gen. sp., Giardia, Cryptosporidium, and Balantidium. Overall, these parasitological findings included four new parasite records for Otaria flavescens, that is, Giardia, Cryptosporidium, Balantidium, and Otostrongylus. The current data serve as a baseline for future monitoring studies on anthropozoonotic parasites circulating in these marine mammals and their potential impact on public health.

  7. Anthropozoonotic Endoparasites in Free-Ranging “Urban” South American Sea Lions (Otaria flavescens)

    Science.gov (United States)

    Silva, Liliana M. R.; Navarro, Mauricio; Taubert, Anja

    2016-01-01

    The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging “urban” colony of South American sea lions (Otaria flavescens) living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF) technique, carbol fuchsin-stained faecal smears and Giardia/Cryptosporidium coproantigen ELISAs, revealed infections with 8 different parasites belonging to protozoan and metazoan taxa with some of them bearing anthropozoonotic potential. Thus, five of these parasites were zoonotic (Diphyllobothriidae gen. sp., Anisakidae gen. sp., Giardia, Cryptosporidium, and Balantidium). Overall, these parasitological findings included four new parasite records for Otaria flavescens, that is, Giardia, Cryptosporidium, Balantidium, and Otostrongylus. The current data serve as a baseline for future monitoring studies on anthropozoonotic parasites circulating in these marine mammals and their potential impact on public health. PMID:27051860

  8. Anthropozoonotic Endoparasites in Free-Ranging "Urban" South American Sea Lions (Otaria flavescens).

    Science.gov (United States)

    Hermosilla, Carlos; Silva, Liliana M R; Navarro, Mauricio; Taubert, Anja

    2016-01-01

    The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging "urban" colony of South American sea lions (Otaria flavescens) living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF) technique, carbol fuchsin-stained faecal smears and Giardia/Cryptosporidium coproantigen ELISAs, revealed infections with 8 different parasites belonging to protozoan and metazoan taxa with some of them bearing anthropozoonotic potential. Thus, five of these parasites were zoonotic (Diphyllobothriidae gen. sp., Anisakidae gen. sp., Giardia, Cryptosporidium, and Balantidium). Overall, these parasitological findings included four new parasite records for Otaria flavescens, that is, Giardia, Cryptosporidium, Balantidium, and Otostrongylus. The current data serve as a baseline for future monitoring studies on anthropozoonotic parasites circulating in these marine mammals and their potential impact on public health.

  9. Second-generation bioethanol from industrial wood waste of South American species

    Directory of Open Access Journals (Sweden)

    María E. Vallejos

    2017-09-01

    Full Text Available There is a global interest in replacing fossil fuels with renewable sources of energy. The present review evaluates the significance of South-American wood industrial wastes for bioethanol production. Four countries have been chosen for this review, i.e., Argentina, Brazil, Chile, and Uruguay, based on their current or potential forestry industry. It should be noted that although Brazil has a global bioethanol market share of 25%, its production is mainly first-generation bioethanol from sugarcane. The situation in the other countries is even worse, in spite of the fact that they have regulatory frameworks in place already allowing the substitution of a percentage of gasoline by ethanol. Pines and eucalyptus are the usually forested plants in these countries, and their industrial wastes, as chips and sawdust, could serve as promising raw materials to produce second-generation bioethanol in the context of a forest biorefinery. The process to convert woody biomass involves three stages: pretreatment, enzymatic saccharification, and fermentation. The operational conditions of the pretreatment method used are generally defined according to the physical and chemical characteristics of the raw materials and subsequently determine the characteristics of the treated substrates. This article also reviews and discusses the available pretreatment technologies for eucalyptus and pines applicable to South-American industrial wood wastes, their enzymatic hydrolysis yields, and the feasibility of implementing such processes in the mentioned countries in the frame of a biorefinery.

  10. A deforestation-induced tipping point for the South American monsoon system

    Science.gov (United States)

    Boers, Niklas; Marwan, Norbert; Barbosa, Henrique M. J.; Kurths, Jürgen

    2017-01-01

    The Amazon rainforest has been proposed as a tipping element of the earth system, with the possibility of a dieback of the entire ecosystem due to deforestation only of parts of the rainforest. Possible physical mechanisms behind such a transition are still subject to ongoing debates. Here, we use a specifically designed model to analyse the nonlinear couplings between the Amazon rainforest and the atmospheric moisture transport from the Atlantic to the South American continent. These couplings are associated with a westward cascade of precipitation and evapotranspiration across the Amazon. We investigate impacts of deforestation on the South American monsoonal circulation with particular focus on a previously neglected positive feedback related to condensational latent heating over the rainforest, which strongly enhances atmospheric moisture inflow from the Atlantic. Our results indicate the existence of a tipping point. In our model setup, crossing the tipping point causes precipitation reductions of up to 40% in non-deforested parts of the western Amazon and regions further downstream. The responsible mechanism is the breakdown of the aforementioned feedback, which occurs when deforestation reduces transpiration to a point where the available atmospheric moisture does not suffice anymore to release the latent heat needed to maintain the feedback.

  11. Normalized difference vegetation index for the South American continent used as a climatic variability indicator

    International Nuclear Information System (INIS)

    Liu, W.T.; Massambani, O.; Festa, M.

    1992-01-01

    The NOAA AVHRR GAC data set was used to produce Normalized Difference Vegetation Index (NDVI) maps for the South American Continent covering the period from August 1, 1981 to June 30, 1987. A 15-day maximum value composite procedure was used to partially eliminate the cloud contamination and atmospheric attenuation. Monthly evolution of NDVI for a dry and a wet year within the period studied was used to estimate the area covered by NDVI value less than 0.223, This value was used as an indicator of the drought area and the delineation of the Low rainfall areas in the continent. It was observed a well defined regional dependence of the drought area variability for the Northeast, Southwest and Northwest continent and also for the Amazon region. It is shown a relative estimation of the area coverage with NDVI less than 0.223 for the years 1982/83 and 1984/85. The dynamics of the drought area evolution in the continent is discussed. It is also presented a diagnosis of regional variability of the continental distribution of drought area from 1981 to 1987 for the months of May and September. This information is also used to discuss its relationship with the EL-Nino-Southern Oscillation (ENSO) and the South American Precipitation patterns during this period. It is suggested that the use of NDVI image to identify the dynamics of the drought induced by low rainfall may provide us valuable information to study the large scale climatic variation

  12. Change in the foraging strategy of female South American sea lions (Carnivora: Pinnipedia after parturition

    Directory of Open Access Journals (Sweden)

    Massimiliano Drago

    2010-08-01

    Full Text Available This study tests the hypothesis that female South American sea lions shift from off-shore, pelagic prey to coastal, benthic prey after parturition in order to reduce the foraging trip duration and hence the time pups remain unattended on the beach during early lactation. The δ13C and δ15N values of the serum and blood cells of 26 South American sea lion suckling pups from northern Patagonia were used to track the dietary changes of their mothers from late pregnancy to early lactation, after correction for differential isotopic fractionation between tissues. Primary producers and potential prey species were also analysed to establish a baseline for interpreting the stable isotope concentration of serum and blood cells. Isotopic ratios revealed a generalized increase in the consumption of coastal-benthic prey after parturition. Such a generalized post-partum shift will allow females to spend more time on land and look after their pups. The effects of this foraging strategy on the nutritional quality of the female’s diet are discussed.

  13. Digenetic trematodes in South American sea lions from southern Brazilian waters.

    Science.gov (United States)

    Pereira, E M; Müller, G; Secchi, E; Pereira, J; Valente, A L S

    2013-10-01

    The aim of this work was to perform a systematic study to detect and quantify the digenetic trematode infections in South American sea lions from the southern Brazilian coast. Twenty-four South American sea lions, Otaria flavescens (Carnivora: Otaridae), were found dead along the coast of Rio Grande do Sul State, Brazil, between June 2010 and September of 2011. Two trematode species were found in the intestines of O. flavescens, i.e., Stephanoprora uruguayense (Digenea: Echinostomatidae) and Ascocotyle (Phagicola) longa (Digenea: Heterophyidae). Ascocotyle (P.) longa reached a prevalence of 33.3% and mean intensity of 248,500, whereas S. uruguayense showed a prevalence of 4.2% and mean intensity of 202. The 2 trematode species infecting sea lions were likely transmitted by feeding on mullets, Mugil platanus, that commonly harbor heterophyid metacercariae. The present work is the first report of digenetic trematodes infecting O. flavescens in Brazil. The high prevalence and mean intensity values of the 2 trematode species infecting sea lions in the present study suggest caution in human consumption of mullets and other fish, which can be infected with the metacercariae of these trematodes known to have zoonotic potential.

  14. IAEA Helps Remove Highly Radioactive Material from Five South American Countries

    International Nuclear Information System (INIS)

    2018-01-01

    The International Atomic Energy Agency (IAEA) has helped remove 27 disused highly radioactive sources from five South American countries in a significant step forward for nuclear safety and security in the region. It was the largest such project ever facilitated by the IAEA. The material, mainly used for medical purposes such as treating cancer and sterilizing instruments, was transported to Germany and the United States for recycling. Canada, where some of the sources were manufactured, funded the project upon requests for IAEA support from Bolivia, Ecuador, Paraguay, Peru and Uruguay. The sealed Cobalt-60 and Caesium-137 sources pose safety and security risks when no longer in use, according to Raja Adnan, Director of the IAEA’s Division of Nuclear Security. “The removal of this large number of radioactive sources has significantly reduced those risks in the five countries,” Adnan said. In recent years, the IAEA has assisted Bosnia and Herzegovina, Cameroon, Costa Rica, Honduras, Lebanon, Morocco, Tunisia and Uzbekistan in the removal of disused sources. The South American operation was the largest the IAEA has so far coordinated in terms of both the number of highly radioactive sources and countries involved. While nuclear safety and security are national responsibilities, the IAEA helps Member States upon request to meet these responsibilities through training, technical advice, peer reviews and other advisory services. Such efforts may include support for Member States in implementing the safe and cost-effective recovery, conditioning, storage, disposal or transportation of disused sealed radioactive sources (DSRS).

  15. Widespread pollution of the South American atmosphere predates the industrial revolution by 240 years

    Science.gov (United States)

    Uglietti, Chiara; Gabrielli, Paolo; Cooke, Colin; Vallelonga, Paul; Thompson, Lonnie

    2015-04-01

    In the Southern Hemisphere, evidence for preindustrial atmospheric pollution is restricted to a few geological archives of low temporal resolution that record trace element deposition originating from past mining and metallurgical operations in South America. Therefore the timing and the spatial impact of these activities on the past atmosphere remain poorly constrained. Here we present an annually resolved ice-core record (793-1989 AD) from the high altitude drilling site of Quelccaya (Peru) that archives preindustrial and industrial variations in trace elements. During the pre-colonial period (i.e., pre-1532 AD), the deposition of trace elements was mainly dominated by the fallout of aeolian dust and of ash from occasional volcanic eruptions indicating that metallurgic production during the Inca Empire (1438-1532 AD) had a negligible impact on the South American atmosphere. In contrast, a widespread anthropogenic signal is evident after 1540 AD, which corresponds with the beginning of colonial mining and metallurgy in Peru and Bolivia, 240 years prior to the Industrial Revolution. This shift was due to a major technological transition for silver extraction in South America (1572 AD), from lead-based smelting to mercury amalgamation, which precipitated a massive increase in mining activities. However, deposition of toxic trace metals during the Colonial era was still several factors lower than 20th century pollution that was unprecedented over the entirety of human history.

  16. On the Origin of the Bolivian High and Related Circulation Features of the South American Climate.

    Science.gov (United States)

    Lenters, J. D.; Cook, K. H.

    1997-03-01

    The climatological structure in the upper-tropospheric summertime circulation over South America is diagnosed using a GCM (with and without South American topography), a linear model, and observational data. Emphasis is placed on understanding the origin of observed features such as the Bolivian high and the accompanying `Nordeste low' to the east. Results from the linear model indicate that these two features are generated in response to precipitation over the Amazon basin, central Andes, and South Atlantic convergence zone, with African precipitation also playing a crucial role in the formation of the Nordeste low. The direct mechanical and sensible heating effects of the Andes are minimal, acting only to induce a weak lee trough in midlatitudes and a shallow monsoonal circulation over the central Andes. In the GCM, the effects of the Andes include a strengthening of the Bolivian high and northward shift of the Nordeste low, primarily through changes in the precipitation field. The position of the Bolivian high is primarily determined by Amazonian precipitation and is little affected by the removal of the Andes. Strong subsidence to the west of the high is found to be important for the maintenance of the high's warm core, while large-scale convective overshooting to the east is responsible for a layer of cold air above the high.

  17. Widespread pollution of the South American atmosphere predates the industrial revolution by 240 y.

    Science.gov (United States)

    Uglietti, Chiara; Gabrielli, Paolo; Cooke, Colin A; Vallelonga, Paul; Thompson, Lonnie G

    2015-02-24

    In the Southern Hemisphere, evidence for preindustrial atmospheric pollution is restricted to a few geological archives of low temporal resolution that record trace element deposition originating from past mining and metallurgical operations in South America. Therefore, the timing and the spatial impact of these activities on the past atmosphere remain poorly constrained. Here we present an annually resolved ice core record (A.D. 793-1989) from the high-altitude drilling site of Quelccaya (Peru) that archives preindustrial and industrial variations in trace elements. During the precolonial period (i.e., pre-A.D. 1532), the deposition of trace elements was mainly dominated by the fallout of aeolian dust and of ash from occasional volcanic eruptions, indicating that metallurgic production during the Inca Empire (A.D. 1438-1532) had a negligible impact on the South American atmosphere. In contrast, a widespread anthropogenic signal is evident after around A.D. 1540, which corresponds with the beginning of colonial mining and metallurgy in Peru and Bolivia, ∼240 y before the Industrial Revolution. This shift was due to a major technological transition for silver extraction in South America (A.D. 1572), from lead-based smelting to mercury amalgamation, which precipitated a massive increase in mining activities. However, deposition of toxic trace metals during the Colonial era was still several factors lower than 20th century pollution that was unprecedented over the entirety of human history.

  18. Cefazolin high-inoculum effect in methicillin-susceptible Staphylococcus aureus from South American hospitals.

    Science.gov (United States)

    Rincón, Sandra; Reyes, Jinnethe; Carvajal, Lina Paola; Rojas, Natalia; Cortés, Fabián; Panesso, Diana; Guzmán, Manuel; Zurita, Jeannete; Adachi, Javier A; Murray, Barbara E; Nannini, Esteban C; Arias, Cesar A

    2013-12-01

    Clinical failures with cefazolin have been described in high-inoculum infections caused by methicillin-susceptible Staphylococcus aureus (MSSA) producing type A β-lactamase. We investigated the prevalence of the cefazolin inoculum effect (InE) in MSSA from South American hospitals, since cefazolin is used routinely against MSSA due to concerns about the in vivo efficacy of isoxazolyl penicillins. MSSA isolates were recovered from bloodstream (n = 296) and osteomyelitis (n = 68) infections in two different multicentre surveillance studies performed in 2001-02 and 2006-08 in South American hospitals. We determined standard-inoculum (10(5)cfu/mL) and high-inoculum (10(7) cfu/mL) cefazolin MICs. PFGE was performed on all isolates that exhibited a cefazolin InE. Multilocus sequence typing (MLST) and sequencing of part of blaZ were performed on representative isolates. The overall prevalence of the cefazolin InE was 36% (131 isolates). A high proportion (50%) of MSSA isolates recovered from osteomyelitis infections exhibited the InE, whereas it was observed in 33% of MSSA recovered from bloodstream infections. Interestingly, Ecuador had the highest prevalence of the InE (45%). Strikingly, 63% of MSSA isolates recovered from osteomyelitis infections in Colombia exhibited the InE. MLST revealed that MSSA isolates exhibiting the InE belonged to diverse genetic backgrounds, including ST5, ST8, ST30 and ST45, which correlated with the prevalent methicillin-resistant S. aureus clones circulating in South America. Types A (66%) and C (31%) were the most prevalent β-lactamases. Our results show a high prevalence of the cefazolin InE associated with type A β-lactamase in MSSA isolates from Colombia and Ecuador, suggesting that treatment of deep-seated infections with cefazolin in those countries may be compromised.

  19. The Eocene South American metatherian Zeusdelphys complicatus is not a protodidelphidid but a hatcheriform: Paleobiogeographic implications

    Directory of Open Access Journals (Sweden)

    Leonardo M. Carneiro

    2017-09-01

    Full Text Available Zeusdelphys complicatus is one of the most enigmatic metatherians from the Itaboraí Basin. The type and only known specimen was previously regarded as the upper dentition of Eobrasilia; an M4 of a new taxon; an M3 of a Kollpaniidae (now regarded as a group of “condylarths”; a probable M1 of an incertae sedis taxon; and as an M1 of a Protodidelphidae. Herein, we present a morphological review of the dental structures of Zeusdelphys complicatus, presenting new interpretations and comparing it with other North and South American taxa. We also perform a phylogenetic analysis in order to test the affinities of Zeusdelphys and the validity of most studied characters. The results recovered Zeusdelphys complicatus as more closely related to Hatcheritherium alpha than to any other metatherian. Glasbiidae were recovered as the sister lineage of Protodidelphidae within Didelphimorphia, as true marsupials. Ectocentrocristus was recovered as the sister taxon of Zeusdelphys + Hatcheritherium, as a Hatcheriformes. The analysis recovered this suborder as an independent lineage from Polydolopimorphia, being more closely related to “Alphadontidae”. The affinities with Protodidelphidae are a result of convergent evolution, as Zeusdelphys is more closely related to Hatcheritherium alpha from the Late Cretaceous of North America. The results support a North American origin for Hatcheriformes. The presence of strong sea-level lowstands and islands in the Caribbean Plate during the Late Cretaceous provide valid data to support a faunal interchange between Americas during the latest Late Cretaceous. Based on the results, Zeusdelphys represents a South American early Eocene surviving Hatcheriformes.

  20. Fission-track dating of South American natural glasses: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Bigazzi, G. [Istituto di Geoscienze e Georisorse, C.N.R., Via G. Moruzzi, 1, 56124 Pisa (Italy)]. E-mail: g.bigazzi@igg.cnr.it; Hadler Neto, J.C. [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, 13083-970 Campinas SP (Brazil); Iunes, P.J. [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, 13083-970 Campinas SP (Brazil); Osorio Araya, A.M. [Departamento de Fisica, Quimica e Biologia, Universidade do Estado de Sao Paulo, UNESP, 19060-900 Presidente Prudente SP (Brazil)

    2005-12-01

    Although many glass-bearing horizons can be found in South American volcanic complexes or sedimentary series, only a relatively few tephra and obsidian-bearing volcanic fields have been studied using the fission-track (FT) dating method. Among them, the volcanics located in the Sierra de Guamani (east of Quito, Ecuador) were studied by several authors. Based upon their ages, obsidians group into three clusters: (1) very young obsidians, {approx}0.2Ma old (2) intermediate-age obsidians, {approx}0.4-{approx}0.8Ma old, and (3) older obsidians, {approx}1.4-{approx}1.6Ma old. The FT method is also an efficient alternative technique for identification of the sources of prehistoric obsidian artefacts. Provenance studies carried out in South America have shown that the Sierra de Guamani obsidian occurrences were important sources of raw material for tool making during pre-Columbian times. Glasses originated from these sources were identified in sites distributed over relatively wide areas of Ecuador and Colombia. Only a few systematic studies on obsidians in other sectors were carried out. Nevertheless, very singular glasses have been recognised in South America, such as Macusanite (Peru) and obsidian Quiron (Argentina), which are being proposed as additional reference materials for FT dating. Analyses of tephra beds interstratified with sedimentary deposits revealed the performance of FT dating in tephrochronological studies. A remarkable example is the famous deposit outcropping at Farola Monte Hermoso, near Bahia Blanca (Buenos Aires Province), described for the first time by the middle of the 19th century by Charles Darwin. Considering the large number of volcanic glasses that were recognised in volcanic complexes and in sedimentary series, South America is a very promising region for the application of FT dating. The examples given above show that this technique may yield important results in different disciplinary fields.

  1. Fission-track dating of South American natural glasses: an overview

    International Nuclear Information System (INIS)

    Bigazzi, G.; Hadler Neto, J.C.; Iunes, P.J.; Osorio Araya, A.M.

    2005-01-01

    Although many glass-bearing horizons can be found in South American volcanic complexes or sedimentary series, only a relatively few tephra and obsidian-bearing volcanic fields have been studied using the fission-track (FT) dating method. Among them, the volcanics located in the Sierra de Guamani (east of Quito, Ecuador) were studied by several authors. Based upon their ages, obsidians group into three clusters: (1) very young obsidians, ∼0.2Ma old (2) intermediate-age obsidians, ∼0.4-∼0.8Ma old, and (3) older obsidians, ∼1.4-∼1.6Ma old. The FT method is also an efficient alternative technique for identification of the sources of prehistoric obsidian artefacts. Provenance studies carried out in South America have shown that the Sierra de Guamani obsidian occurrences were important sources of raw material for tool making during pre-Columbian times. Glasses originated from these sources were identified in sites distributed over relatively wide areas of Ecuador and Colombia. Only a few systematic studies on obsidians in other sectors were carried out. Nevertheless, very singular glasses have been recognised in South America, such as Macusanite (Peru) and obsidian Quiron (Argentina), which are being proposed as additional reference materials for FT dating. Analyses of tephra beds interstratified with sedimentary deposits revealed the performance of FT dating in tephrochronological studies. A remarkable example is the famous deposit outcropping at Farola Monte Hermoso, near Bahia Blanca (Buenos Aires Province), described for the first time by the middle of the 19th century by Charles Darwin. Considering the large number of volcanic glasses that were recognised in volcanic complexes and in sedimentary series, South America is a very promising region for the application of FT dating. The examples given above show that this technique may yield important results in different disciplinary fields

  2. Knowledge and screening of head and neck cancer among American Indians in South Dakota.

    Science.gov (United States)

    Dwojak, Sunshine; Deschler, Daniel; Sargent, Michele; Emerick, Kevin; Guadagnolo, B Ashleigh; Petereit, Daniel

    2015-06-01

    We established the level of awareness of risk factors and early symptoms of head and neck cancer among American Indians in South Dakota and determined whether head and neck cancer screening detected clinical findings in this population. We used the European About Face survey. We added questions about human papillomavirus, a risk factor for head and neck cancer, and demographics. Surveys were administered at 2 public events in 2011. Participants could partake in a head and neck cancer screening at the time of survey administration. Of the 205 American Indians who completed the survey, 114 participated in the screening. Mean head and neck cancer knowledge scores were 26 out of 44. Level of education was the only factor that predicted higher head and neck cancer knowledge (b = 0.90; P = .01). Nine (8%) people had positive head and neck cancer screening examination results. All abnormal clinical findings were in current or past smokers (P = .06). There are gaps in American Indian knowledge of head and neck cancer risk factors and symptoms. Community-based head and neck cancer screening in this population is feasible and may be a way to identify early abnormal clinical findings in smokers.

  3. Time, Space, and National Belonging in The Namesake: Redrawing South Asian American Citizenship in the Shadow of 9/11

    Directory of Open Access Journals (Sweden)

    Sue Brennan

    2011-03-01

    Full Text Available The terms of national belonging after 9/11 for South Asian Americans have taken shape through a vague and depoliticized discourse around ethnic identity, one in which the clichés of multiculturalism and melting-pot nationalism stand in for the specific socioeconomic and historical conditions that helped form the South Asian diaspora in the US. This paper explores the ways in which Jhumpa Lahiri’s novel The Namesake and its cinematic adaptation by filmmaker Mira Nair challenge the erasure of South Asian American citizenship following 9/11. Recounting the journey of a young Bengali graduate student and his wife migrating to the US in the late 1960s, each text speaks back to the erasure of South Asian American citizenship through the materialization of time in space: while Lahiri foregrounds the state itself in producing the rhythms through which immigrants are assimilated into the nation, Nair creates a narrative world in which filmic space materializes many, and often competing, histories, unifying multiple temporalities and histories through the representations of space. I argue that the cinematic adaptation of The Namesake generates a new spatiotemporal state of affairs, one in which the iconography of 9/11 both challenges post-9/11 racial logics and destabilizes the singular, progressive, and institutionalized temporality through which Lahiri writes South Asian American immigrants back into nation.

  4. Phylogenetic evidence for cladogenetic polyploidization in land plants.

    Science.gov (United States)

    Zhan, Shing H; Drori, Michal; Goldberg, Emma E; Otto, Sarah P; Mayrose, Itay

    2016-07-01

    Polyploidization is a common and recurring phenomenon in plants and is often thought to be a mechanism of "instant speciation". Whether polyploidization is associated with the formation of new species (cladogenesis) or simply occurs over time within a lineage (anagenesis), however, has never been assessed systematically. We tested this hypothesis using phylogenetic and karyotypic information from 235 plant genera (mostly angiosperms). We first constructed a large database of combined sequence and chromosome number data sets using an automated procedure. We then applied likelihood models (ClaSSE) that estimate the degree of synchronization between polyploidization and speciation events in maximum likelihood and Bayesian frameworks. Our maximum likelihood analysis indicated that 35 genera supported a model that includes cladogenetic transitions over a model with only anagenetic transitions, whereas three genera supported a model that incorporates anagenetic transitions over one with only cladogenetic transitions. Furthermore, the Bayesian analysis supported a preponderance of cladogenetic change in four genera but did not support a preponderance of anagenetic change in any genus. Overall, these phylogenetic analyses provide the first broad confirmation that polyploidization is temporally associated with speciation events, suggesting that it is indeed a major speciation mechanism in plants, at least in some genera. © 2016 Botanical Society of America.

  5. Whole-body γ-irradiation decelerates rat hepatocyte polyploidization.

    Science.gov (United States)

    Ikhtiar, Adnan M

    2015-07-01

    To characterize hepatocyte polyploidization induced by intermediate dose of γ-ray. Male Wistar strain rats were whole-body irradiated (WBI) with 2 Gy of γ-ray at the age of 1 month, and 5-6 rats were sacrificed monthly at 0-25 months after irradiation. The nuclear DNA content of individual hepatocytes was measured by flow cytometry, then hepatocytes were classified into various ploidy classes. Survival percentage, after exposure up to the end of the study, did not indicate any differences between the irradiated groups and controls. The degree of polyploidization in hepatocytes of irradiated rats, was significantly lower than that for the control after 1 month of exposure, and it continued to be lower after up to 8 months. Thereafter, the degree of polyploidization in the irradiated group slowly returned to the control level when the irradiated rats reached the age of 10 months. Intermediate dose of ionizing radiation, in contrast to high doses, decelerate hepatocyte polyploidization, which may coincides with the hypothesis of the beneficial effects of low doses of ionizing radiation.

  6. Dietary regulation of hypodermal polyploidization in C. elegans

    Directory of Open Access Journals (Sweden)

    Lozano Encarnación

    2008-03-01

    Full Text Available Abstract Background Dietary restriction (DR results in increased longevity, reduced fecundity and reduced growth in many organisms. Though many studies have examined the effects of DR on longevity and fecundity, few have investigated the effects on growth. Results Here we use Caenorhabditis elegans to determine the mechanisms that regulate growth under DR. We show that rather than a reduction in cell number, decreased growth in wild type C. elegans under DR is correlated with lower levels of hypodermal polyploidization. We also show that mutants lacking wild type sensory ciliated neurons are small, exhibit hypo-polyploidization and more importantly, when grown under DR, reduce their levels of endoreduplication to a lesser extent than wild type, suggesting that these neurons are required for the regulation of hypodermal polyploidization in response to DR. Similarly, we also show that the cGMP-dependent protein kinase EGL-4 and the SMA/MAB signalling pathway regulate polyploidization under DR. Conclusion We show C. elegans is capable of actively responding to food levels to regulate adult ploidy. We suggest this response is dependent on the SMA/MAB signalling pathway.

  7. Dietary regulation of hypodermal polyploidization in C. elegans.

    Science.gov (United States)

    Tain, Luke S; Lozano, Encarnación; Sáez, Alberto G; Leroi, Armand M

    2008-03-12

    Dietary restriction (DR) results in increased longevity, reduced fecundity and reduced growth in many organisms. Though many studies have examined the effects of DR on longevity and fecundity, few have investigated the effects on growth. Here we use Caenorhabditis elegans to determine the mechanisms that regulate growth under DR. We show that rather than a reduction in cell number, decreased growth in wild type C. elegans under DR is correlated with lower levels of hypodermal polyploidization. We also show that mutants lacking wild type sensory ciliated neurons are small, exhibit hypo-polyploidization and more importantly, when grown under DR, reduce their levels of endoreduplication to a lesser extent than wild type, suggesting that these neurons are required for the regulation of hypodermal polyploidization in response to DR. Similarly, we also show that the cGMP-dependent protein kinase EGL-4 and the SMA/MAB signalling pathway regulate polyploidization under DR. We show C. elegans is capable of actively responding to food levels to regulate adult ploidy. We suggest this response is dependent on the SMA/MAB signalling pathway.

  8. Production of polyploids from cultured shoot tips of Eucalyptus ...

    African Journals Online (AJOL)

    Polyploids from cultured shoot tips of Eucalyptus globulus were produced by treatment with colchicine. Results showed that the combination of 0.5% colchicine and treating multiple shoot clumps for 4 days was the most appropriate conditions for E. globulus polyploidy induction and the effect of the use of multiple shoot ...

  9. Helminth parasites of South American fishes: current status and characterization as a model for studies of biodiversity.

    Science.gov (United States)

    Luque, J L; Pereira, F B; Alves, P V; Oliva, M E; Timi, J T

    2017-03-01

    The South American subcontinent supports one of the world's most diverse and commercially very important ichthyofauna. In this context, the study of South American fish parasites is of increased relevance in understanding their key roles in ecosystems, regulating the abundance or density of host populations, stabilizing food webs and structuring host communities. It is hard to estimate the number of fish parasites in South America. The number of fish species studied for parasites is still low (less than 10%), although the total number of host-parasite associations (HPAs) found in the present study was 3971. Monogeneans, with 835 species (1123 HPAs, 28.5%), and trematodes, with 662 species (1127 HPAs, 30.9%), are the more diverse groups. Data gathered from the literature are useful to roughly estimate species richness of helminths from South American fish, even though there are some associated problems: the reliability of information depends on accurate species identification; the lack of knowledge about life cycles; the increasing number of discoveries of cryptic species and the geographically biased number of studies. Therefore, the closest true estimations of species diversity and distribution will rely on further studies combining both molecular and morphological approaches with ecological data such as host specificity, geographical distribution and life-cycle data. Research on biodiversity of fish parasites in South America is influenced by problems such as funding, taxonomic impediments and dispersion of research groups. Increasing collaboration, interchange and research networks in the context of globalization will enable a promising future for fish parasitology in South America.

  10. Quantifying the humanitarian and economic impact of earthquakes on South American capital cities (Invited)

    Science.gov (United States)

    Zoback, M. L.; Cabrera, C.; Pomonis, A.; Baca, A.; Brunner, I.; Cheung, G.; Chen, A.; Nagel, B.; Carrasco, S.

    2009-12-01

    By 2000, an estimated 80% of South America’s population lived in urban areas (Veblen et al., The Physical Geography of South America, Oxford University Press, 2007). A significant fraction of those urban dwellers resides in the capital cities which are major economic centers and act as magnets for rural poor and refugees. This population concentration includes many residents living in extreme poverty in substandard and informal housing, often on the margins of these capital cities and sometimes on steep slopes, greatly compounding the vulnerability to natural hazards. We are analyzing the humanitarian and economic risk for six of the seismically most-at-risk South American capitals along the northern and western plate boundaries of South America: Caracas, Venezuela; Bogotá, Colombia; Quito, Ecuador; Lima, Perú; La Paz, Bolivia; and Santiago, Chile. Impacts are provided in the form of expected losses for a specific “likely” scenario earthquake and in a probabilistic format using exceedance probability curves (probability of exceeding a given loss in different return periods). Impacts to be quantified include: total economic losses, potential fatalities, potential serious injuries, and the number of displaced households. Probabilistic seismic hazard was developed in collaboration with numerous South American experts and includes subduction interface, intraslab, background crustal and, where available, active fault sources. A significant challenge for this study is to accurately account for the exposure and vulnerability of populations living in the informal, shanty areas. Combining analysis of aerial imagery and on-the-ground reconnaissance, we define between 20-30 “inventory districts” of relatively uniform construction styles within each capital. Statistical distributions of the different construction types and their characteristics (height, occupancy, year built, average value) are estimated for each district. In addition, working with local graduate

  11. American Indian Parents’ Assessment of and Concern About Their Kindergarten Child’s Weight Status, South Dakota, 2005-2006

    OpenAIRE

    Arcan, Chrisa; Hannan, Peter J.; Himes, John H.; Fulkerson, Jayne A.; Holy Rock, Bonnie; Smyth, Mary; Story, Mary

    2012-01-01

    Introduction Obesity is highly prevalent among American Indians, and effective prevention efforts require caregiver involvement. We examined American Indian (AI) parents' assessment of and level of concern about their kindergarten child's weight status. Methods We collected baseline data (fall of 2005 and fall of 2006) on children and their parents or caregivers for a school-based obesity prevention trial (Bright Start) on an AI reservation in South Dakota. The current study uses 413 parent-c...

  12. The adrenergic retulation of the cardiovascular system in the South American rattlesnake, Crotalus durissus

    DEFF Research Database (Denmark)

    Galli, G.L.J.; Jensen, Nini Skovgaard; Abe, A.S.

    2007-01-01

    The present study investigates adrenergic regulation of the systemic and pulmonary circulations of the anaesthetised South American rattlesnake, Crotalus durissus. Haemodynamic measurements were made following bolus injections of adrenaline and adrenergic antagonists administered through a systemic...... arterial catheter. Adrenaline caused a marked systemic vasoconstriction that was abolished by phentolamine, indicating this response was mediated through α-adrenergic receptors. Injection of phentolamine gave rise to a pronounced vasodilatation (systemic conductance (Gsys) more than doubled), while...... injection of propranolol caused a systemic vasoconstriction, pointing to a potent α-adrenergic, and a weaker β-adrenergic tone in the systemic vasculature of Crotalus. Overall, the pulmonary vasculature was far less responsive to adrenergic stimulation than the systemic circulation. Adrenaline caused...

  13. [South American camelids in Switzerland. II. Reference values for blood parameters].

    Science.gov (United States)

    Hengrave Burri, I; Tschudi, P; Martig, J; Liesegang, A; Meylan, M

    2005-08-01

    In order to establish reference values for blood parameters of South American camelids in Switzerland, 273 blood samples were collected from 141 llamas and 132 alpacas. These animals were classified in three categories (young animals blood cell count, white blood cell count, electrolytes, metabolites and enzymes). Significant differences between llamas and alpacas were evident for 26 parameters. This study also showed that differences between young animals, females and males must be taken into consideration. A comparison of blood values with the results of fecal analysis for parasite eggs showed that an infestation with Dicrocoelium dendriticum was associated with elevated activity of two liver enzymes (GLDH and gamma-GT) in the serum. In contrast, no differences were found in the results of blood analyses between animals shedding eggs of gastrointestinal strongyles or not.

  14. Comparing fairness perceptions of personnel selection techniques of American, French and South African job applicants

    Directory of Open Access Journals (Sweden)

    Delene Visser

    2001-12-01

    Full Text Available The purpose of the study was to determine whether job applicants' perceptions of commonly used selection procedures vary across nationalities, because a negative impression of prospective employers that use selection techniques that are viewed as unfair, may result. In this study the fairness perceptions of 179 South African employees were compared with results obtained with 142 American and 117 French participants with regard to ten selection techniques using the framework of organisational justice theory. Opsomming Die doel van die ondersoek was om te bepaal of werkaansoekers van verskillende nasionaliteite se persepsies van bekende keuringsprosedures verskil. Indien voomemende werkgewers keuringstegnieke wat as onbillik beskou word, gebruik, kan 'n negatiewe beeld van hul organisasies geskep word. In hierdie studie is 179 Suid-Afrikaanse werknemers se persepsies van tien keuringstegnieke binne die raamwerk van organisasiebillikheidsteone vergelyk met persepsies van 142 Amerikaanse en 117 Franse respondente, In die algemeen was die Suid-Afrikaanse Wit groep die positiefste teenoor die keuringstegnieke.

  15. Angiotensin-converting enzyme (ACE) alleles in the Quechua, a high altitude South American native population.

    Science.gov (United States)

    Rupert, J L; Devine, D V; Monsalve, M V; Hochachka, P W

    1999-01-01

    Recently it was reported that an allelic variant of the gene encoding angiotensin-converting enzyme (ACE) was significantly over-represented in a cohort of elite British mountaineers. It was proposed that this may be evidence for a specific genetic factor influencing the human capacity for physical performance. The implication that this allele could enhance performance at high altitude prompted us to determine its frequency in Quechua speaking natives living at altitudes greater than 3000m on the Andean Altiplano in South America. We found that the frequency of the putative performance allele in the Quechuas, although significantly higher than in Caucasians, was not different from lowland Native American populations. This observation suggests that, although the higher frequency of the 'performance allele' may have facilitated the migration of the ancestral Quechua to the highlands, the ACE insertion allele has not been subsequently selected for in this high altitude population.

  16. Emergence of wheat blast in Bangladesh was caused by a South American lineage of Magnaporthe oryzae.

    Science.gov (United States)

    Islam, M Tofazzal; Croll, Daniel; Gladieux, Pierre; Soanes, Darren M; Persoons, Antoine; Bhattacharjee, Pallab; Hossain, Md Shaid; Gupta, Dipali Rani; Rahman, Md Mahbubur; Mahboob, M Golam; Cook, Nicola; Salam, Moin U; Surovy, Musrat Zahan; Sancho, Vanessa Bueno; Maciel, João Leodato Nunes; NhaniJúnior, Antonio; Castroagudín, Vanina Lilián; Reges, Juliana T de Assis; Ceresini, Paulo Cezar; Ravel, Sebastien; Kellner, Ronny; Fournier, Elisabeth; Tharreau, Didier; Lebrun, Marc-Henri; McDonald, Bruce A; Stitt, Timothy; Swan, Daniel; Talbot, Nicholas J; Saunders, Diane G O; Win, Joe; Kamoun, Sophien

    2016-10-03

    In February 2016, a new fungal disease was spotted in wheat fields across eight districts in Bangladesh. The epidemic spread to an estimated 15,000 hectares, about 16 % of the cultivated wheat area in Bangladesh, with yield losses reaching up to 100 %. Within weeks of the onset of the epidemic, we performed transcriptome sequencing of symptomatic leaf samples collected directly from Bangladeshi fields. Reinoculation of seedlings with strains isolated from infected wheat grains showed wheat blast symptoms on leaves of wheat but not rice. Our phylogenomic and population genomic analyses revealed that the wheat blast outbreak in Bangladesh was most likely caused by a wheat-infecting South American lineage of the blast fungus Magnaporthe oryzae. Our findings suggest that genomic surveillance can be rapidly applied to monitor plant disease outbreaks and provide valuable information regarding the identity and origin of the infectious agent.

  17. Adhesive and invasive capacities of Edwarsiella tarda isolated from South American sea lion

    Directory of Open Access Journals (Sweden)

    Araceli Fernández

    2014-09-01

    Full Text Available Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and invasive ability of 17 E. tarda strains isolated from SASL fecal material. All the strains were able to adhere and invade HEp-2 cells with adhesion and invasion percentages ranging from 56 to 100% and 21 to 74%, respectively. Despite the expression of these pathogenic factors, further investigation is needed to determine whether this bacterium could play a role as primary pathogen for this and other species of pinnipeds.

  18. Adhesive and invasive capacities of Edwardsiella tarda isolated from South American sea lion.

    Science.gov (United States)

    Fernández, Araceli; Villanueva, María Paz; González, Mario; Fernández, Fabiola; Latif, Fadua; Flores, Sandra Nonier; Fernández, Heriberto

    2014-01-01

    Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL) Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and invasive ability of 17 E. tarda strains isolated from SASL fecal material. All the strains were able to adhere and invade HEp-2 cells with adhesion and invasion percentages ranging from 56 to 100% and 21 to 74%, respectively. Despite the expression of these pathogenic factors, further investigation is needed to determine whether this bacterium could play a role as primary pathogen for this and other species of pinnipeds.

  19. Adhesive and invasive capacities of Edwarsiella tarda isolated from South American sea lion

    Science.gov (United States)

    Fernández, Araceli; Villanueva, María Paz; González, Mario; Fernández, Fabiola; Latif, Fadua; Flores, Sandra Nonier; Fernández, Heriberto

    2014-01-01

    Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL) Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and invasive ability of 17 E. tarda strains isolated from SASL fecal material. All the strains were able to adhere and invade HEp-2 cells with adhesion and invasion percentages ranging from 56 to 100% and 21 to 74%, respectively. Despite the expression of these pathogenic factors, further investigation is needed to determine whether this bacterium could play a role as primary pathogen for this and other species of pinnipeds. PMID:25477948

  20. Morphological divergence in a continental adaptive radiation: South American ovenbirds of the genus Cinclodes

    Science.gov (United States)

    Rader, Jonathan A.; Dillon, Michael E.; Chesser, R. Terry; Sabat, Pablo; Martinez del Rio, Carlos

    2015-01-01

    Cinclodes is an ecologically diverse genus of South American passerine birds and represents a case of continental adaptive radiation along multiple axes. We investigated morphological diversification in Cinclodes using a comprehensive set of morphometric measurements of study skins. Principal component analysis identified 2 primary axes of morphological variation: one describing body size and a second capturing differences in wing-tip shape and toe length. Phylogenetic analyses of the first principal component suggest an early divergence ofCinclodes into 2 main clades characterized by large and small body sizes. We suggest that 2 morphological outliers within these main clades (C. antarcticus and C. palliatus) may be cases of island gigantism and that a third (C. patagonicus) may reflect ecological character displacement. Despite its ecological and physiological diversity, the genus Cinclodes does not appear to show morphological diversity beyond what is typical of other avian genera.

  1. Invasion of South American suckermouth armoured catfishes Pterygoplichthys spp. (Loricariidae in Kerala, India - a case study

    Directory of Open Access Journals (Sweden)

    A. Bijukumar

    2015-03-01

    Full Text Available This paper documents the occurrence of the exotic South American suckermouth armoured catfishes (Loricariidae of the genus Pterygoplichthys spp. in the drainages of Thiruvananthapuram City, Kerala.  The morphological taxonomy revealed that the specimens are closely related to Pterygoplichthys disjunctivus (Weber, 1991 and P. pardalis (Castelnau, 1855, in addition to intermediary forms of unknown identity.  DNA barcoding using the mitochondrial DNA cytochrome c oxidase 1 (CO1 also failed to establish the identity of the invaded species.  There may be possible hybridisation in aquariums or in fish farms or in the wild, but this needs to be found out aided by detailed studies incorporating different molecular markers and with sequences of topotypes.  The possible threats due to Pterygoplichthys spp. invasion and management options are discussed in the paper. 

  2. Diet-to-female and female-to-pup isotopic discrimination in South American sea lions.

    Science.gov (United States)

    Drago, Massimiliano; Franco-Trecu, Valentina; Cardona, Luis; Inchausti, Pablo

    2015-08-30

    The use of accurate, species-specific diet-tissue discrimination factors is a critical requirement when applying stable isotope mixing models to predict consumer diet composition. Thus, diet-to-female and female-to-pup isotopic discrimination factors in several tissues for both captive and wild South American sea lions were estimated to provide appropriate values for quantifying feeding preferences at different timescales in the wild populations of this species. Stable carbon and nitrogen isotope ratios in the blood components of two female-pup pairs and females' prey muscle from captive individuals were determined by elemental analyzer/isotope ratio mass spectrometry (EA/IRMS) to calculate the respective isotopic discrimination factors. The same analysis was carried out in both blood components, and skin and hair tissues for eight female-pup pairs from wild individuals. Mean diet-to-female Δ(13) C and Δ(15) N values were higher than the female-to-pup ones. Pup tissues were more (15) N-enriched than their mothers but (13) C-depleted in serum and plasma tissues. In most of the tissue comparisons, we found differences in both Δ(15) N and Δ(13) C values, supporting tissue-specific discrimination. We found no differences between captive and wild female-to-pup discrimination factors either in Δ(13) C or Δ(15) N values of blood components. Only the stable isotope ratios in pup blood are good proxies of the individual lactating females. Thus, we suggest that blood components are more appropriate to quantify the feeding habits of wild individuals of this species. Furthermore, because female-to-pup discrimination factors for blood components did not differ between captive and wild individuals, we suggest that results for captive experiments can be extrapolated to wild South American sea lion populations. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Revision of the Bee Genus Chlerogella (Hymenoptera, Halictidae, Part II: South American Species and Generic Diagnosis

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    Michael Engel

    2010-05-01

    Full Text Available The South American species of the rare bee genus Chlerogella Michener (Halictinae: Augochlorini are revised, completing the study of the genus. Chlerogella diversity is significantly expanded beyond the five previously described South American species of Cherlogella azurea (Enderlein, comb. n., C. nasus (Enderlein, C. mourella Engel, C. octogesima (Brooks & Engel, comb. n., and C. buyssoni (Vachal. Twenty-two new species are described – C. agaylei sp. n., C. arhyncha sp. n., C. borysthenis sp. n., C. breviceps sp. n., C. cochabambensis sp. n., C. cooperella sp. n., C. cyranoi sp. n., C. dolichorhina sp. n., C. elysia sp. n., C. eumorpha sp. n., C. euprepia sp. n., C. hauseri sp. n., C. hypermeces sp. n., C. materdonnae sp. n., C. oresbios sp. n., C. picketti sp. n., C. rostrata sp. n., C. silvula sp. n., C. terpsichore sp. n., C. tychoi sp. n., C. vachali sp. n., C. xuthopleura sp. n. – and the distribution of the genus is expanded beyond Perú and Ecuador to include Bolivia, Colombia, and Venezuela. The female of C. azurea is described for the first time while the placement of Halictus buyssoni Vachal in Chlerogella is considered tentative, following the usage of previous authors, as the holotype and sole specimen is untraceable. The genus is newly diagnosed based on a greater understanding of variation in malar length across the species and a dichotomous key is provided. New floral records for species of Chlerogella include Psychotria pongoana Standl. (Rubiaceae and a putative record on Phragmopedium longifolium (Warsz. & Rchb.f. Rolfe (Orchidaceae.

  4. Evaluation of depressive symptoms in mid-aged women: report of a multicenter South American study.

    Science.gov (United States)

    Salazar-Pousada, Danny; Monterrosa-Castro, Alvaro; Ojeda, Eliana; Sánchez, Sandra C; Morales-Luna, Ingrid F; Pérez-López, Faustino R; Chedraui, Peter

    2017-11-01

    To evaluate depressive symptoms and related factors among mid-aged women using the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10). This was a cross-sectional multicenter study in which women aged 40 to 65 from various South American countries were surveyed with the CESD-10 and a general questionnaire containing personal and partner data. In all, 864 women were interviewed from Colombia (Afro-Colombian, n = 215), Ecuador (Mestizo, n = 202), Perú (Quechua at high altitude, n = 231), and Paraguay (Mestizo, n = 216). Mean age of the whole sample was 49.1 ± 6.0 years. Although the rate of postmenopausal status was similar among studied sites, differences were observed in relation to age, parity, hormone therapy use, hot flush rate, sedentary lifestyle, chronic medical conditions, habits, and partner aspects. Median total CESD-10 score for all sites was 7.0, with a 36.0% (n = 311) having scores equal to 10 or more (suggestive of depressed mood). Higher scores were observed for Afro-Colombian and Quechua women, and also for postmenopausal and perimenopausal ones. Multivariate linear regression analysis found that depressed mood (higher CESD-10 total scores) was significantly associated with ethnicity (Afro-Colombian), hot flush severity, hormone therapy use, sedentary lifestyle, postmenopause, perceived unhealthy status, and lower education. Higher monthly coital frequency and having a healthy partner without premature ejaculation was related to lower scores, hence less depressed mood. In this mid-aged female South American sample, depressive symptoms correlated to menopausal status and related aspects, ethnicity, and personal and partner issues. All these features require further research.

  5. Diet, dietary selectivity and density of South American grey fox, Lycalopex griseus, in Central Chile.

    Science.gov (United States)

    Muñoz-Pedreros, Andrés; Yáñez, José; Norambuena, Heraldo V; Zúñiga, Alfredo

    2018-01-01

    The South American grey fox Lycalopex griseus is a canid widely distributed in southern South America; however, some aspects of its biology are still poorly known. We studied the diet and density of L. griseus in the Lago Peñuelas Biosphere Reserve, in Central Chile. The trophic niche breadth was B = 6.16 (B sta = 0.47) and prey diversity was H' = 2.46 (H max ' = 3.17, J' = 0.78). The highest proportions of prey consumed in the diet were Oryctolagus cuniculus (52.21%) and other mammals (32.78%). We compared these results with a latitudinal gradient of diet results for this species in Chile. L. griseus eats mostly mammals (>90% of total prey), consuming the rodent Phyllotis darwini and reptiles in the northern zone; Oryctolagus cuniculus, Octodon degus and Abrocoma bennetti in the central zone; Abrothrix spp. and lagomorphs in the southern zone; and Lepus capensis and Ovis aries in the austral zone. The estimated density of L. griseus in Lago Peñuelas NR was 1.3 foxes/km 2 . © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  6. Comparative study of the atmospheric chemical composition of three South American cities

    Science.gov (United States)

    Vasconcellos, Pérola C.; Souza, Davi Z.; Ávila, Simone G.; Araújo, Maria P.; Naoto, Edson; Nascimento, Kátia H.; Cavalcante, Fernando S.; Dos Santos, Marina; Smichowski, Patricia; Behrentz, Eduardo

    2011-10-01

    PM10 samples were collected in 2008 at three sites in South America in the framework of an international project (South American Emissions Megacities, and Climate; SAEMC). The concentration of metals, metalloids, ion and organic compounds of most PM10 samples collected at three sites (Buenos Aires (BAI), Bogotá (BOG) and São Paulo (SPA)) is below the air quality standard of the respective countries. At the sites n-alkanes and carbon preference index distribution indicated the influence of petroleum residues derived from vehicular emissions. Most PAH detected are attributed to light-duty gasoline vehicles and to stationary sources. At all sites benzo[a]pyrene equivalent values mean a significant cancer risk. Sulfate, nitrate, ammonium, calcium and sodium are the most abundant water-soluble ions at the three sites. Ammonium sulfate is likely the form presented for these species formed by photochemical reactions of precursors emitted mainly by vehicles. At BAI and SPA, formate/acetate ratios indicated the contribution of photochemical reactions; on the contrary, at BOG site, acetate is predominant, indicating strong contribution of vehicular emissions. São Paulo samples showed the highest concentrations of elements among all the sites. None of the toxic or potentially toxic elements exceed the guideline values of the World Health Organization. At BAI site earth crust seems to be the major source of Fe and Mn; at SPA, anthropogenic source is responsible for Pb and Zn presences. Traffic related element is well correlated at the three sites.

  7. Lamanema chavezi (Nematoda: Molineidae): epidemiological data of the infection in South American camelids of Northwest Argentina.

    Science.gov (United States)

    Cafrune, M M; Marín, R E; Rigalt, F A; Romero, S R; Aguirre, D H

    2009-12-23

    Faecal samples from llamas (n=708), vicuñas (n=171) and guanacos (n=4) were obtained between December 2004 and May 2009 in three Provinces of Northwest Argentina (Jujuy, Salta and Catamarca) to know the distribution, prevalence and intensity of Lamanema chavezi infection in these South American camelid species (SACs). Faeces were examined by a sedimentation-flotation technique using a Cl(2)Zn+ClNa solution (specific gravity=1.59). Eggs of L. chavezi occurred in 30.3% of 89 llama herds and in 18.5% of 708 llamas sampled with a mean intensity of 271.8 eggs/g (EPG) of faeces (range 20-2120). The highest values for all parameters of the infection were registered in llamas from Catamarca Province. Significant differences (P<0.001, Fisher's exact test) were detected only for the lower prevalence in llamas from Jujuy respect to those from the other two Provinces. The overall individual prevalence of L. chavezi in llamas was lower than in reports from adult domestic camelids of neighbour countries while mean intensity was higher. The individual prevalence of L. chavezi in guanacos was 75.0%, with a mean intensity of 66.0 EPG (range 40-120) while no vicuñas were detected as infected. Most of infected SACs were located at the phytogeographical region of Andean Patagonic Domain with a dispersion ranging between 22 degrees 10' and 26 degrees 40' South latitude.

  8. Testing Bergmann's rule and the Rosenzweig hypothesis with craniometric studies of the South American sea lion.

    Science.gov (United States)

    Sepúlveda, Maritza; Oliva, Doris; Duran, L René; Urra, Alejandra; Pedraza, Susana N; Majluf, Patrícia; Goodall, Natalie; Crespo, Enrique A

    2013-04-01

    We tested the validity of Bergmann's rule and Rosenzweig's hypothesis through an analysis of the geographical variation of the skull size of Otaria flavescens along the entire distribution range of the species (except Brazil). We quantified the sizes of 606 adult South American sea lion skulls measured in seven localities of Peru, Chile, Uruguay, Argentina, and the Falkland/Malvinas Islands. Geographical and environmental variables included latitude, longitude, and monthly minimum, maximum, and mean air and ocean temperatures. We also included information on fish landings as a proxy for productivity. Males showed a positive relationship between condylobasal length (CBL) and latitude, and between CBL and the six temperature variables. By contrast, females showed a negative relationship between CBL and the same variables. Finally, female skull size showed a significant and positive correlation with fish landings, while males did not show any relationship with this variable. The body size of males conformed to Bergmann's rule, with larger individuals found in southern localities of South America. Females followed the converse of Bergmann's rule at the intraspecific level, but showed a positive relationship with the proxy for productivity, thus supporting Rosenzweig's hypothesis. Differences in the factors that drive body size in females and males may be explained by their different life-history strategies. Our analyses demonstrate that latitude and temperature are not the only factors that explain spatial variation in body size: others such as food availability are also important for explaining the ecogeographical patterns found in O. flavescens.

  9. Metagenomic Survey of Viral Diversity Obtained from Feces of Subantarctic and South American Fur Seals.

    Directory of Open Access Journals (Sweden)

    Mariana Kluge

    Full Text Available The Brazilian South coast seasonally hosts numerous marine species, observed particularly during winter months. Some animals, including fur seals, are found dead or debilitated along the shore and may harbor potential pathogens within their microbiota. In the present study, a metagenomic approach was performed to evaluate the viral diversity in feces of fur seals found deceased along the coast of the state of Rio Grande do Sul. The fecal virome of two fur seal species was characterized: the South American fur seal (Arctocephalus australis and the Subantarctic fur seal (Arctocephalus tropicalis. Fecal samples from 10 specimens (A. australis, n = 5; A. tropicalis, n = 5 were collected and viral particles were purified, extracted and amplified with a random PCR. The products were sequenced through Ion Torrent and Illumina platforms and assembled reads were submitted to BLASTx searches. Both viromes were dominated by bacteriophages and included a number of potentially novel virus genomes. Sequences of picobirnaviruses, picornaviruses and a hepevirus-like were identified in A. australis. A rotavirus related to group C, a novel member of the Sakobuvirus and a sapovirus very similar to California sea lion sapovirus 1 were found in A. tropicalis. Additionally, sequences of members of the Anelloviridae and Parvoviridae families were detected in both fur seal species. This is the first metagenomic study to screen the fecal virome of fur seals, contributing to a better understanding of the complexity of the viral community present in the intestinal microbiota of these animals.

  10. Seasonal precipitation patterns along pathways of South American low-level jets and aerial rivers

    Science.gov (United States)

    Poveda, Germán.; Jaramillo, Liliana; Vallejo, Luisa F.

    2014-01-01

    We study the seasonal dynamics of the eastern Pacific (CHOCO) and Caribbean low-level jets (LLJ), and aerial rivers (AR) acting on tropical and subtropical South America. Using the ERA-Interim reanalysis (1979-2012), we show that the convergence of both LLJs over the eastern Pacific-western Colombia contributes to the explanation of the region's world-record rainfall. Diverse variables involved in the transport and storage of moisture permit the identification of an AR over northern South America involving a midtropospheric easterly jet that connects the Atlantic and Pacific Oceans across the Andes, with stronger activity in April to August. Other major seasonal AR pathways constitute part of a large gyre originating over the tropical North Atlantic, veering to the southeast over the eastern Andes and reaching regions of northern Argentina and southeastern Brazil. We illustrate the distribution of average seasonal precipitation along the LLJs and AR pathways with data from the Tropical Rainfall Measuring Mission (1998-2011), combined with considerations of CAPE, topography, and land cover. In addition, the theory of the biotic pump of atmospheric moisture (BiPAM) is tested at seasonal time scales, and found to hold in 8 out of 12 ARs, and 22 out of 32 forest-covered tracks (64% in distance) along the ARs. Deviations from BiPAM's predictions of rainfall distribution are explained by the effects of topography, orography, and land cover types different from forests. Our results lend a strong observational support to the BiPAM theory at seasonal time scales over South American forested flat lands.

  11. Short-Term Dynamic and Local Epidemiological Trends in the South American HIV-1B Epidemic.

    Directory of Open Access Journals (Sweden)

    Dennis Maletich Junqueira

    Full Text Available The human displacement and sexual behavior are the main factors driving the HIV-1 pandemic to the current profile. The intrinsic structure of the HIV transmission among different individuals has valuable importance for the understanding of the epidemic and for the public health response. The aim of this study was to characterize the HIV-1 subtype B (HIV-1B epidemic in South America through the identification of transmission links and infer trends about geographical patterns and median time of transmission between individuals. Sequences of the protease and reverse transcriptase coding regions from 4,810 individuals were selected from GenBank. Maximum likelihood phylogenies were inferred and submitted to ClusterPicker to identify transmission links. Bayesian analyses were applied only for clusters including ≥5 dated samples in order to estimate the median maximum inter-transmission interval. This study analyzed sequences sampled from 12 South American countries, from individuals of different exposure categories, under different antiretroviral profiles, and from a wide period of time (1989-2013. Continentally, Brazil, Argentina and Venezuela were revealed important sites for the spread of HIV-1B among countries inside South America. Of note, from all the clusters identified about 70% of the HIV-1B infections are primarily occurring among individuals living in the same geographic region. In addition, these transmissions seem to occur early after the infection of an individual, taking in average 2.39 years (95% CI 1.48-3.30 to succeed. Homosexual/Bisexual individuals transmit the virus as quickly as almost half time of that estimated for the general population sampled here. Public health services can be broadly benefitted from this kind of information whether to focus on specific programs of response to the epidemic whether as guiding of prevention campaigns to specific risk groups.

  12. Short-Term Dynamic and Local Epidemiological Trends in the South American HIV-1B Epidemic.

    Science.gov (United States)

    Junqueira, Dennis Maletich; de Medeiros, Rubia Marília; Gräf, Tiago; Almeida, Sabrina Esteves de Matos

    2016-01-01

    The human displacement and sexual behavior are the main factors driving the HIV-1 pandemic to the current profile. The intrinsic structure of the HIV transmission among different individuals has valuable importance for the understanding of the epidemic and for the public health response. The aim of this study was to characterize the HIV-1 subtype B (HIV-1B) epidemic in South America through the identification of transmission links and infer trends about geographical patterns and median time of transmission between individuals. Sequences of the protease and reverse transcriptase coding regions from 4,810 individuals were selected from GenBank. Maximum likelihood phylogenies were inferred and submitted to ClusterPicker to identify transmission links. Bayesian analyses were applied only for clusters including ≥5 dated samples in order to estimate the median maximum inter-transmission interval. This study analyzed sequences sampled from 12 South American countries, from individuals of different exposure categories, under different antiretroviral profiles, and from a wide period of time (1989-2013). Continentally, Brazil, Argentina and Venezuela were revealed important sites for the spread of HIV-1B among countries inside South America. Of note, from all the clusters identified about 70% of the HIV-1B infections are primarily occurring among individuals living in the same geographic region. In addition, these transmissions seem to occur early after the infection of an individual, taking in average 2.39 years (95% CI 1.48-3.30) to succeed. Homosexual/Bisexual individuals transmit the virus as quickly as almost half time of that estimated for the general population sampled here. Public health services can be broadly benefitted from this kind of information whether to focus on specific programs of response to the epidemic whether as guiding of prevention campaigns to specific risk groups.

  13. Regional integration and Brazilian Foreign Policy: Strategies in the South American space

    Directory of Open Access Journals (Sweden)

    Cristina Soreanu Pecequilo

    2013-12-01

    Full Text Available The aim of the article is to present, based on theoretical studies of integration, the evolution of this process in Latin America and, most recently, in South America. Based on these studies, the goal is to analyze the role played by Brazil in the process, which defines as priorities of its foreign policy a regional and global framework for its international action that is based on both cooperation and power projection.The research has been conducted based on theories of integration, an historical background on Latin American integration and in Brazilian foreign policy, through its contemporary agenda. The answer was based on a comparative agenda and in a bibliographical critical analysis of the research material.The main findings of the paper point out that Latin American integration has specific features linked to the economic, political and stragetic realities of the continent that show the limitations of some theories applied to the European process, also that it depends on Brazilian foreign policy actions, that still sees the region as instrumental to its interests. So, Brazil sometimes fail to fulfill some requisites of integration that are essential to sustain its projects. Therefore, there is a cycle of enlargement and deepening of regional integration process in this political space that point out to the need of a more sustained compromise of Brazilian foreign policy towards these projects. If Brazil continues not to sustain these projects, they will lose momentum and significance once more, increasing power asymmetries in the region.

  14. Mitochondrial DNA variability among six South American Amerindian villages from the Pano linguistic group.

    Science.gov (United States)

    Mendes-Junior, Celso T; Simoes, Aguinaldo L

    2014-01-01

    Although scattered throughout a large geographic area, the members of the Pano linguistic group present strong ethnic, linguistic, and cultural homogeneity, a feature that causes them to be considered components of a same "Pano" tribe. Nevertheless, the genetic homogeneity between Pano villages has not yet been examined. To study the genetic structure of the Pano linguistic group, four major Native American mitochondrial DNA (mtDNA) founder haplogroups were analyzed in 77 Amerindians from six villages of four Pano tribes (Katukina, Kaxináwa, Marúbo, and Yaminawa) located in the Brazilian Amazon. The central position of these tribes in the continent makes them relevant for attempts to reconstruct population movements in South America. Except for a single individual that presented an African haplogroup L, all remaining individuals presented one of the four Native American haplogroups. Significant heterogeneity was observed across the six Pano villages. Although Amerindian populations are usually characterized by considerable interpopulational diversity, the high heterogeneity level observed is unexpected if the strong ethnic, linguistic, and cultural homogeneity of the Pano linguistic group is taken into account. The present findings indicate that the ethnic, linguistic, and cultural homogeneity does not imply genetic homogeneity. Even though the genetic heterogeneity uncovered may be a female-specific process, the most probable explanation for that is the joint action of isolation and genetic drift as major factors influencing the genetic structure of the Pano linguistic group. Copyright © 2014 Wayne State University Press, Detroit, Michigan 48201-1309.

  15. Seismic hazard of American Samoa and neighboring South Pacific Islands--methods, data, parameters, and results

    Science.gov (United States)

    Petersen, Mark D.; Harmsen, Stephen C.; Rukstales, Kenneth S.; Mueller, Charles S.; McNamara, Daniel E.; Luco, Nicolas; Walling, Melanie

    2012-01-01

    American Samoa and the neighboring islands of the South Pacific lie near active tectonic-plate boundaries that host many large earthquakes which can result in strong earthquake shaking and tsunamis. To mitigate earthquake risks from future ground shaking, the Federal Emergency Management Agency requested that the U.S. Geological Survey prepare seismic hazard maps that can be applied in building-design criteria. This Open-File Report describes the data, methods, and parameters used to calculate the seismic shaking hazard as well as the output hazard maps, curves, and deaggregation (disaggregation) information needed for building design. Spectral acceleration hazard for 1 Hertz having a 2-percent probability of exceedance on a firm rock site condition (Vs30=760 meters per second) is 0.12 acceleration of gravity (1 second, 1 Hertz) and 0.32 acceleration of gravity (0.2 seconds, 5 Hertz) on American Samoa, 0.72 acceleration of gravity (1 Hertz) and 2.54 acceleration of gravity (5 Hertz) on Tonga, 0.15 acceleration of gravity (1 Hertz) and 0.55 acceleration of gravity (5 Hertz) on Fiji, and 0.89 acceleration of gravity (1 Hertz) and 2.77 acceleration of gravity (5 Hertz) on the Vanuatu Islands.

  16. NeQuick 2 and IRI Plas VTEC predictions for low latitude and South American sector

    Science.gov (United States)

    Ezquer, R. G.; Scidá, L. A.; Migoya Orué, Y.; Nava, B.; Cabrera, M. A.; Brunini, C.

    2018-04-01

    Using vertical total electron content (VTEC) measurements obtained from GPS satellite signals the capability of the NeQuick 2 and IRI Plas models to predict VTEC over the low latitude and South American sector is analyzed. In the present work both models were used to calculate VTEC up to the height of GPS satellites. Also, comparisons between the performance of IRI Plas and IRI 2007 have been done. The data correspond to June solstice and September equinox 1999 (high solar activity) and they were obtained at nine stations. The considered latitude range extends from 18.4°N to -64.7°N and the longitude ranges from 281.3°E to 295.9°E in the South American sector. The greatest discrepancies among model predictions and the measured VTEC are obtained at low latitudes stations placed in the equatorial anomaly region. Underestimations as strong as 40 TECU [1 TECU = 1016 m-2] can be observed at BOGT station for September equinox, when NeQuick2 model is used. The obtained results also show that: (a) for June solstice, in general the performance of IRI Plas for low latitude stations is better than that of NeQuick2 and, vice versa, for highest latitudes the performance of NeQuick2 is better than that of IRI Plas. For the stations TUCU and SANT both models have good performance; (b) for September equinox the performances of the models do not follow a clearly defined pattern as in the other season. However, it can be seen that for the region placed between the Northern peak and the valley of the equatorial anomaly, in general, the performance of IRI Plas is better than that of NeQuick2 for hours of maximum ionization. From TUCU to the South, the best TEC predictions are given by NeQuick2. The source of the observed deviations of the models has been explored in terms of CCIR foF2 determination in the available ionosonde stations in the region. Discrepancies can be also related to an unrealistic shape of the vertical electron density profile and or an erroneous prediction of

  17. Precipitation changes in the South American Altiplano since 1300 AD reconstructed by tree-rings

    Directory of Open Access Journals (Sweden)

    M. S. Morales

    2012-03-01

    Full Text Available Throughout the second half of the 20th century, the Central Andes has experienced significant climatic and environmental changes characterized by a persistent warming trend, an increase in elevation of the 0 °C isotherm, and sustained glacier shrinkage. These changes have occurred in conjunction with a steadily growing demand for water resources. Given the short span of instrumental hydroclimatic records in this region, longer time span records are needed to understand the nature of climate variability and to improve the predictability of precipitation, a key factor modulating the socio-economic development in the South American Altiplano and adjacent arid lowlands. In this study we present the first quasi-millennial, tree-ring based precipitation reconstruction for the South American Altiplano. This annual (November–October precipitation reconstruction is based on the Polylepis tarapacana tree-ring width series and represents the closest dendroclimatological record to the Equator in South America. This high-resolution reconstruction covers the past 707 yr and provides a unique record characterizing the occurrence of extreme events and consistent oscillations in precipitation. It also allows an assessment of the spatial and temporal stabilities of the teleconnections between rainfall in the Altiplano and hemispheric forcings such as El Niño-Southern Oscillation. Since the 1930s to present, a persistent negative trend in precipitation has been recorded in the reconstruction, with the three driest years since 1300 AD occurring in the last 70 yr. Throughout the 707 yr, the reconstruction contains a clear ENSO-like pattern at interannual to multidecadal time scales, which determines inter-hemispheric linkages between our reconstruction and other precipitation sensitive records modulated by ENSO in North America. Our reconstruction points out that century-scale dry periods are a recurrent feature in the Altiplano climate, and that the

  18. Crustal evolution of South American Platform based on Sm-Nd isotope geochemistry

    International Nuclear Information System (INIS)

    Sato, Kei

    1998-01-01

    Sm-Nd isotopic systematics is relevant to the topics of origin and evolution the of continental crust, where model ages refer to the time when crustal material was differentiated from the upper mantle. Alternative interpretations are due to a lack of adequate information on crustal processes and the variable composition of the mantle sources. The Sm-Nd methods are presented, and applied on rock materials from the South American Platform. The main conclusions indicate juvenile accretion with higher growth rates (peaks), around 3.7-3.5 Ga (∼ 0.5% in volume), 3.1 - 2.9 Ga (∼16%), 2.7 - 2.6 (∼ 9%), 2.2 - 1.9 (35%) and 1.3-1.0 (7%). The continental growth curve indicates that about 35 % of the crust was formed by 2.5 Ga, 88% by 1.8 Ga and 99% by 1.0 Ga, and the remaining ∼ 1 % was added in the Phanerozoic. Rapid crustal growth occurred between 2.2 and 1.9 Ga. The main period of continental crust formation occurred during the Paleoproterozoic, corresponding to 54 % in volume. Sm-Nd model ages, when compared with the crystallisation ages of granitoid rocks, furnish a rough estimate of juvenile vs. reworked material. Within the South American Platform about 45% of juvenile continental crust is still preserved within tectonic provinces of different ages. The remainder represents continental crust reworked in younger tectono-thermal events. In particular crustal reworking was predominating over juvenile accretion during Meso-Neoproterozoic. The Transbrasiliano Lineament is a megasuture, active in the Neoproterozoic, which separates a large northwestern mass, including the Amazonian and Sao Luis Cratons, from a southeastern mass, formed by a collage of cratonic fragments, of which the Sao Francisco and Rio de La Plata are the largest. The crustal evolutions of these two large continental masses are considered individually, and can be resumed following form: I - Old Archean rocks (>3.4 Ga) are found only within the south-eastern part (Gaviao Block, Contendas

  19. "No Unfavorable Comments from Any Quarter": Teaching Black History to White Students in the American South, 1928-1943

    Science.gov (United States)

    Woyshner, Christine

    2012-01-01

    Background/Context: The history curriculum is often used to help reach the goal of racial tolerance and understanding by teaching about the nation's diversity. Many educators believe that teaching about diverse peoples in schools will bring about greater equity in society. This historical study looks at the segregated American South from 1928 to…

  20. Strategies to Improve Teacher Retention in American Overseas Schools in the Near East South Asia Region: A Qualitative Analysis

    Science.gov (United States)

    Mancuso, Steven V.; Roberts, Laura; White, George P.; Yoshida, Roland K.; Weston, David

    2011-01-01

    Using a qualitative analysis and drawing from sociological theory, this study examined reasons for teacher turnover and retention from a representative sample of 248 teachers in American overseas schools in the Near East South Asia region. Results suggested that the most important reasons to stay or move pertained to supportive leadership,…

  1. Prevalence and genetic diversity of haematozoa in South American waterfowl and evidence for intercontinental redistribution of parasites by migratory birds

    Science.gov (United States)

    Smith, Matthew M.; Ramey, Andy M.

    2015-01-01

    To understand the role of migratory birds in the movement and transmission of haematozoa within and between continental regions, we examined 804 blood samples collected from eleven endemic species of South American waterfowl in Peru and Argentina for infection by Haemoproteus, Plasmodium, and/or Leucocytozono blood parasites. Infections were detected in 25 individuals of six species for an overall apparent prevalence rate of 3.1%. Analysis of haematozoa mitochondrial DNA revealed twelve distinct parasite haplotypes infecting South American waterfowl, four of which were identical to lineages previously observed infecting ducks and swans sampled in North America. Analysis of parasite mitochondrial DNA sequences revealed close phylogenetic relationships between lineages originating from waterfowl samples regardless of continental affiliation. In contrast, more distant phylogenetic relationships were observed between parasite lineages from waterfowl and passerines sampled in South America for Haemoproteus and Leucocytozoon, suggesting some level of host specificity for parasites of these genera. The detection of identical parasite lineages in endemic, South American waterfowl and North American ducks and swans, paired with the close phylogenetic relationships of haematozoa infecting waterfowl on both continents, provides evidence for parasite redistribution between these regions by migratory birds.

  2. Review of the South American characiform fish genus Chilodus, with description of a new species, C. gracilis (Pisces, Characiformes, Chilodontidae)

    NARCIS (Netherlands)

    Isbrücker, I.J.H.; Nijssen, H.

    1988-01-01

    Examination of 291 specimens of Chilodus, a genus of South American fresh water fishes, yielded the presence of three species, viz.: C. punctatus, C. zunevei, and C. gracilis. Of the first species the lectotype is designated. The type material of C. zunevei is lost; new material enabled a

  3. 76 FR 18419 - Movement of Hass Avocados From Areas Where Mediterranean Fruit Fly or South American Fruit Fly Exist

    Science.gov (United States)

    2011-04-04

    ... where the infested avocados were grown will immediately be suspended from the export program until an... Avocados From Areas Where Mediterranean Fruit Fly or South American Fruit Fly Exist AGENCY: Animal and... certain restrictions regarding the movement of fresh Hass variety avocados. Specifically, we are proposing...

  4. 75 FR 41237 - Public Land Order No. 7746; Withdrawal of Public Lands, South Fork of the American River; California

    Science.gov (United States)

    2010-07-15

    ... DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLCAC08000-L1430000-ET0000; CACA 41334] Public Land Order No. 7746; Withdrawal of Public Lands, South Fork of the American River; California AGENCY: Bureau of Land Management, Interior. ACTION: Public Land Order. SUMMARY: This order withdraws 2...

  5. Crustal and upper mantle investigations of the Caribbean-South American plate boundary

    Science.gov (United States)

    Bezada, Maximiliano J.

    The evolution of the Caribbean --- South America plate boundary has been a matter of vigorous debate for decades and many questions remain unresolved. In this work, and in the framework of the BOLIVAR project, we shed light on some aspects of the present state and the tectonic history of the margin by using different types of geophysical data sets and techniques. An analysis of controlled-source traveltime data collected along a boundary-normal profile at ˜65°W was used to build a 2D P-wave velocity model. The model shows that the Caribbean Large Igenous Province is present offshore eastern Venezuela and confirms the uniformity of the velocity structure along the Leeward Antilles volcanic belt. In contrast with neighboring profiles, at this longitude we see no change in velocity structure or crustal thickness across the San Sebastian - El Pilar fault system. A 2D gravity modeling methodology that uses seismically derived initial density models was developed as part of this research. The application of this new method to four of the BOLIVAR boundary-normal profiles suggests that the uppermost mantle is denser under the South American continental crust and the island arc terranes than under the Caribbean oceanic crust. Crustal rocks of the island arc and extended island arc terranes of the Leeward Antilles have a relatively low density, given their P-wave velocity. This may be caused by low iron content, relative to average magmatic arc rocks. Finally, an analysis of teleseismic traveltimes with frequency-dependent kernels produced a 3D P-wave velocity perturbation model. The model shows the structure of the mantle lithosphere under the study area and clearly images the subduction of the Atlantic slab and associated partial removal of the lower lithosphere under northern South America. We also image the subduction of a section of the Caribbean plate under South America with an east-southeast direction. Both the Atlantic and Caribbean subducting slabs penetrate the

  6. Genetic Differentiation within the Puccinia triticina Population in South America and Comparison with the North American Population Suggests Common Ancestry and Intercontinental Migration

    Science.gov (United States)

    Leaf rust, caused by Puccinia triticina is the most prevalent and widespread disease of wheat in South America. The objective of this study was to determine the number of genetically differentiated groups of P. triticina that are currently present in South America, and to compare the South American ...

  7. The energy geopolitics interests: the Initiative for South American Regional Integration - ISARI; Os interesses da geopolitica energetica: a Iniciativa para Integracao Regional Sul Americana - IIRSA

    Energy Technology Data Exchange (ETDEWEB)

    Jeronymo, Alexandre; Roig, Carla de Almeida; Guerra, Sinclair Mallet Guy [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Programa de Pos-Graduacao em Energia], e-mail: alexandre.jeronymo@ufabc.edu.br, e-mail: carla.roig@ufabc.edu.br, e-mail: sguerra@ufabc.edu.br

    2008-07-01

    This work adds itself to the debates on the project Integration of South America Regional Infrastructure - ISARI. Its focus is related with Energy Geopolitics and the South America integration under the world system of commodities production. The ISARI, as a project oriented to the viability of low value aggregated which should be transported from the south american continent for consumption at the world market.

  8. Prevalence of neurodevelopmental disorders among low-income African Americans at a clinic on Chicago's south side.

    Science.gov (United States)

    Bell, Carl C; Chimata, Radhika

    2015-05-01

    This study examined the point prevalence of neurodevelopmental disorders among predominantly low-income, African-American psychiatric patients at Jackson Park Hospital's Family Medicine Clinic on Chicago's South Side. Using active case ascertainment methodology, the authors assessed the records of 611 psychiatric patients visiting the clinic between May 23, 2013, and January 14, 2014, to identify those with DSM-5 neurodevelopmental disorders. A total of 297 patients (49%) met criteria for a neurodevelopmental disorder during childhood. Moreover, 237 (39%) had clinical profiles consistent with neurobehavioral disorder associated with prenatal alcohol exposure, and 53 (9%) had other neurodevelopmental disorders. The authors disagreed on the specific type of neurodevelopmental disorder of seven (1% of 611) of the 297 patients with neurodevelopmental disorders. A high prevalence of neurodevelopmental disorders was found among low-income predominantly African-American psychiatric patients on Chicago's South Side. If replicated, these findings should bring about substantial changes in medical practice with African-American patients.

  9. Megakaryocyte polyploidization is associated with decreased expression of polo-like kinase (PLK).

    Science.gov (United States)

    Yagi, M; Roth, G J

    2006-09-01

    During differentiation, megakaryocytes (MK), the bone marrow precursors of circulating blood platelets, undergo polyploidization, repeated rounds of DNA replication without cell division. Mature normal MK may contain a DNA content of up to 128N, in contrast to normal diploid (2N) cells. The extent of polyploidy may influence the number of platelets produced by the MK. Therefore, understanding the molecular mechanisms regulating polyploidization could identify events involved in controlling both cell division and thrombopoiesis. We investigated the expression of several proteins involved in mitosis in cultured mouse MK, and tested the effect of expression on polyploidization. Western blot and immunofluorescent analyses were used to assess expression of cell cycle proteins in cultured MK. Populations of polyploidizing MK were separated on the basis of DNA content by flow cytometry. The gene encoding mouse polo-like kinase 1 (PLK-1) was introduced into MK by retroviral transduction, and its effects measured by flow cytometry. Polyploid mouse MK expressed lower levels of two proteins, p55CDC and PLK-1, whose activity is necessary for cell cycle progression and completion of mitosis. Comparison of sorted 2N/4N and polyploid MK indicated that PLK-1 expression was absent in polyploid MK, while expression of other cell cycle proteins was similar in both populations. Forced expression of PLK-1 during MK differentiation was associated with decreased polyploidization. These experiments suggest that PLK-1 is an important regulator of polyploidization in differentiating MK.

  10. E2F8 is essential for polyploidization in mammalian cells.

    Science.gov (United States)

    Pandit, Shusil K; Westendorp, Bart; Nantasanti, Sathidpak; van Liere, Elsbeth; Tooten, Peter C J; Cornelissen, Peter W A; Toussaint, Mathilda J M; Lamers, Wouter H; de Bruin, Alain

    2012-11-01

    Polyploidization is observed in all mammalian species and is a characteristic feature of hepatocytes, but its molecular mechanism and biological significance are unknown. Hepatocyte polyploidization in rodents occurs through incomplete cytokinesis, starts after weaning and increases with age. Here, we show in mice that atypical E2F8 is induced after weaning and required for hepatocyte binucleation and polyploidization. A deficiency in E2f8 led to an increase in the expression level of E2F target genes promoting cytokinesis and thereby preventing polyploidization. In contrast, loss of E2f1 enhanced polyploidization and suppressed the polyploidization defect of hepatocytes deficient for atypical E2Fs. In addition, E2F8 and E2F1 were found on the same subset of target promoters. Contrary to the long-standing hypothesis that polyploidization indicates terminal differentiation and senescence, we show that prevention of polyploidization through inactivation of atypical E2Fs has, surprisingly, no impact on liver differentiation, zonation, metabolism and regeneration. Together, these results identify E2F8 as a repressor and E2F1 as an activator of a transcriptional network controlling polyploidization in mammalian cells.

  11. The functional relevance of polyploidization in the skin.

    Science.gov (United States)

    Trakala, Marianna; Malumbres, Marcos

    2014-02-01

    Cell proliferation and differentiation are tightly coupled through the regulation of the cell division cycle. To preserve specific functional properties in differentiated cells, distinct variants of the basic mitotic cell cycle are used in various mammalian tissues, leading to the formation of polyploid cells. In this issue of Experimental Dermatology, Gandarillas and Freije discuss the evidences for polyploidization in keratinocytes, a process whose physiological relevance is now becoming evident. A better evaluation of these unconventional cell cycles is required not only to improve our understanding of the development and structure of the epidermis but also for future therapies against skin diseases. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Evolutionarily advanced ant farmers rear polyploid fungal crops

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus; Aanen, D.K.; Schiøtt, Morten

    2015-01-01

    to be lowly and facultatively polyploid (just over two haplotypes on average), whereas Atta and Acromyrmex symbionts are highly and obligatorily polyploid (ca. 5-7 haplotypes on average). This stepwise transition appears analogous to ploidy variation in plants and fungi domesticated by humans and in fungi...... the number of nuclei per fungal cell for 42 symbionts reared by 14 species of Panamanian fungus-growing ants. This showed that domesticated symbionts of higher attine ants are polykaryotic with 7-17 nuclei per cell, whereas nonspecialized crops of lower attines are dikaryotic similar to most free...... domesticated by termites and plants, where gene or genome duplications were typically associated with selection for higher productivity, but allopolyploid chimerism was incompatible with sexual reproduction....

  13. The effect of South American biomass burning aerosol emissions on the regional climate

    Science.gov (United States)

    Thornhill, Gillian D.; Ryder, Claire L.; Highwood, Eleanor J.; Shaffrey, Len C.; Johnson, Ben T.

    2018-04-01

    The impact of biomass burning aerosol (BBA) on the regional climate in South America is assessed using 30-year simulations with a global atmosphere-only configuration of the Met Office Unified Model. We compare two simulations of high and low emissions of biomass burning aerosol based on realistic interannual variability. The aerosol scheme in the model has hygroscopic growth and optical properties for BBA informed by recent observations, including those from the recent South American Biomass Burning Analysis (SAMBBA) intensive aircraft observations made during September 2012. We find that the difference in the September (peak biomass emissions month) BBA optical depth between a simulation with high emissions and a simulation with low emissions corresponds well to the difference in the BBA emissions between the two simulations, with a 71.6 % reduction from high to low emissions for both the BBA emissions and the BB AOD in the region with maximum emissions (defined by a box of extent 5-25° S, 40-70° W, used for calculating mean values given below). The cloud cover at all altitudes in the region of greatest BBA difference is reduced as a result of the semi-direct effect, by heating of the atmosphere by the BBA and changes in the atmospheric stability and surface fluxes. Within the BBA layer the cloud is reduced by burn-off, while the higher cloud changes appear to be responding to stability changes. The boundary layer is reduced in height and stabilized by increased BBA, resulting in reduced deep convection and reduced cloud cover at heights of 9-14 km, above the layer of BBA. Despite the decrease in cloud fraction, September downwelling clear-sky and all-sky shortwave radiation at the surface is reduced for higher emissions by 13.77 ± 0.39 W m-2 (clear-sky) and 7.37 ± 2.29 W m-2 (all-sky), whilst the upwelling shortwave radiation at the top of atmosphere is increased in clear sky by 3.32 ± 0.09 W m-2, but decreased by -1.36±1.67 W m-2 when cloud changes are

  14. Comparable ages for the independent origins of electrogenesis in African and South American weakly electric fishes.

    Directory of Open Access Journals (Sweden)

    Sébastien Lavoué

    Full Text Available One of the most remarkable examples of convergent evolution among vertebrates is illustrated by the independent origins of an active electric sense in South American and African weakly electric fishes, the Gymnotiformes and Mormyroidea, respectively. These groups independently evolved similar complex systems for object localization and communication via the generation and reception of weak electric fields. While good estimates of divergence times are critical to understanding the temporal context for the evolution and diversification of these two groups, their respective ages have been difficult to estimate due to the absence of an informative fossil record, use of strict molecular clock models in previous studies, and/or incomplete taxonomic sampling. Here, we examine the timing of the origins of the Gymnotiformes and the Mormyroidea using complete mitogenome sequences and a parametric bayesian method for divergence time reconstruction. Under two different fossil-based calibration methods, we estimated similar ages for the independent origins of the Mormyroidea and Gymnotiformes. Our absolute estimates for the origins of these groups either slightly postdate, or just predate, the final separation of Africa and South America by continental drift. The most recent common ancestor of the Mormyroidea and Gymnotiformes was found to be a non-electrogenic basal teleost living more than 85 millions years earlier. For both electric fish lineages, we also estimated similar intervals (16-19 or 22-26 million years, depending on calibration method between the appearance of electroreception and the origin of myogenic electric organs, providing rough upper estimates for the time periods during which these complex electric organs evolved de novo from skeletal muscle precursors. The fact that the Gymnotiformes and Mormyroidea are of similar age enhances the comparative value of the weakly electric fish system for investigating pathways to evolutionary novelty

  15. Functional morphology and wasp pollination of two South American asclepiads (Asclepiadoideae-Apocynaceae).

    Science.gov (United States)

    Wiemer, A P; Sérsic, A N; Marino, S; Simões, A O; Cocucci, A A

    2012-01-01

    BACKGROUND AND AIMS The extreme complexity of asclepiad flowers (Asclepiadoideae-Apocynaceae) has generated particular interest in the pollination biology of this group of plants especially in the mechanisms involved in the pollination processes. This study compares two South American species, Morrenia odorata and Morrenia brachystephana, with respect to morphology and anatomy of flower structures, dynamic aspects of the pollination mechanism, diversity of visitors and effectiveness of pollinators. Floral structure was studied with fresh and fixed flowers following classical techniques. The pollination mechanism was studied by visiting fresh flowers in the laboratory with artificial pollinator body parts created with an eyelash. Morphometric and nectar measurements were also taken. Pollen transfer efficiency in the flowers was calculated by recording the frequency of removed and inserted pollinia. Visitor activity was recorded in the field, and floral visitors were captured for subsequent analysis of pollen loads. Finally, pollinator effectiveness was calculated with an index. The detailed structure of the flowers revealed a complex system of guide rails and chambers precisely arranged in order to achieve effective pollinaria transport. Morrenia odorata is functionally specialized for wasp pollination, and M. brachystephana for wasp and bee pollination. Pollinators transport chains of pollinaria adhered to their mouthparts. Morrenia odorata and M. brachystephana present differences in the morphology and size of their corona, gynostegium and pollinaria, which explain the differences in details of the functioning of the general pollination mechanism. Pollination is performed by different groups of highly effective pollinators. Morrenia species are specialized for pollination mainly by several species of wasps, a specialized pollination which has been poorly studied. In particular, pompilid wasps are reported as important pollinators in other regions outside South

  16. Comparative transmission genetics of introgressed chromatin in Gossypium (cotton) polyploids.

    Science.gov (United States)

    Waghmare, Vijay N; Rong, Junkang; Rogers, Carl J; Bowers, John E; Chee, Peng W; Gannaway, John R; Katageri, Ishwarappa; Paterson, Andrew H

    2016-04-01

    Introgression is widely acknowledged as a potential source of valuable genetic variation, and growing effort is being invested in analysis of interspecific crosses conferring transgressive variation. Experimental backcross populations provide an opportunity to study transmission genetics following interspecific hybridization, identifying opportunities and constraints to introgressive crop improvement. The evolutionary consequences of introgression have been addressed at the theoretical level, however, issues related to levels and patterns of introgression among (plant) species remain inadequately explored, including such factors as polyploidization, subgenome interaction inhabiting a common nucleus, and the genomic distribution and linkage relationships of introgressant alleles. We analyze introgression into the polyploid Gossypium hirsutum (upland cotton) from its sister G. tomentosum and compare the level and pattern with that of G. barbadense representing a different clade tracing to the same polyploidization. Across the genome, recurrent backcrossing to Gossypium hirsutum yielded only one-third of the expected average frequency of the G. tomentosum allele, although one unusual region showed preferential introgression. Although a similar rate of introgression is found in the two subgenomes of polyploid (AtDt) G. hirsutum, a preponderance of multilocus interactions were largely within the Dt subgenome. Skewed G. tomentosum chromatin transmission is polymorphic among two elite G. hirsutum genotypes, which suggests that genetic background may profoundly affect introgression of particular chromosomal regions. Only limited correspondence is found between G. hirsutum chromosomal regions that are intolerant to introgression from the two species, G. barbadense and G. tomentosum, concentrated near possible inversion polymorphisms. Complex transmission of introgressed chromatin highlights the challenges to utilization of exotic germplasm in crop improvement. © 2016

  17. 7Be content in rainfall and soil deposition in South American coastal ecosystems

    International Nuclear Information System (INIS)

    Cardoso, R.; Ayub, J. Juri; Anjos, Roberto Meigikos dos; Cid, Alberto Silva; Velasco, H.

    2011-01-01

    Full text: Research about input, circulation and accumulation of natural and anthropogenic radionuclides in terrestrial ecosystems allows examining sources, establishing time scales and elucidating environmental processes. Thinking this way, researchers at UFF and UNSL have applied short-lived particle-reactive tracers to understand the behaviour of species evolution, functioning and restorations of natural and semi-natural ecosystems as well as to investigate the patterns and frequency of disturbances due to modern global changes. This can be accomplished through a detailed understanding on the hydrology and water circulation pattern, soil characteristics, erosion, resuspension, reduction/oxidation, speciation, precipitation and accumulation, diagenetic processes and microbial activities. 7 Be is a natural radionuclide (Eγ = 477.6 keV, t 1 / 2 = 53.3 d), which originates in the upper atmosphere as a result of bombardment by cosmic rays. The global distribution of this radionuclide provides a valuable means for testing and validating global circulation models on short time-scales. Its removal from the atmosphere by wet or dry deposition provides a useful tool for developing and validation of models about transport processes from the troposphere to the land surface. Knowledge of site-specific atmospheric fluxes is also crucial to evaluate the impact of atmospherically delivered pollutants on terrestrial ecosystems. The distribution of South American lands on different latitudes and its diversified topography can influence the development and action of many atmospheric systems contributing to generate non-homogeneous climatic conditions in this region. Increasing anthropogenic loads can further modify the precipitation rates and hence the climate of this region. Therefore it is important to study intra-system and inter-system interactions in different South American terrestrial ecosystems. Since 2006, UNSL has been investigating the 7 Be contents in rainfall and

  18. Diversity and disparity of sparassodonts (Metatheria) reveal non-analogue nature of ancient South American mammalian carnivore guilds

    Science.gov (United States)

    Dolgushina, Tatiana; Wesley, Gina

    2018-01-01

    This study investigates whether terrestrial mammalian carnivore guilds of ancient South America, which developed in relative isolation, were similar to those of other continents. We do so through analyses of clade diversification, ecomorphology and guild structure in the Sparassodonta, metatherians that were the predominant mammalian carnivores of pre-Pleistocene South America. Body mass and 16 characters of the dentition are used to quantify morphological diversity (disparity) in sparassodonts and to compare them to extant marsupial and placental carnivores and extinct North American carnivoramorphans. We also compare trophic diversity of the Early Miocene terrestrial carnivore guild of Santa Cruz, Argentina to that of 14 modern and fossil guilds from other continents. We find that sparassodonts had comparatively low ecomorphological disparity throughout their history and that South American carnivore palaeoguilds, as represented by that of Santa Cruz, Argentina, were unlike modern or fossil carnivore guilds of other continents in their lack of mesocarnivores and hypocarnivores. Our results add to a growing body of evidence highlighting non-analogue aspects of extinct South American mammals and illustrate the dramatic effects that historical contingency can have on the evolution of mammalian palaeocommunities. PMID:29298933

  19. Docetaxel-induced polyploidization may underlie chemoresistance and disease relapse.

    Science.gov (United States)

    Ogden, Angela; Rida, Padmashree C G; Knudsen, Beatrice S; Kucuk, Omer; Aneja, Ritu

    2015-10-28

    Although docetaxel significantly improves survival in a variety of malignancies, its clinical utility is severely restricted by acquired chemoresistance and disease relapse. To uncover the mechanisms underlying these all too common occurrences, an abundance of research has focused on mutations and gene expression patterns; however, these findings are yet to translate into improved outcomes for patients being administered this drug. These analyses have overlooked a promising lead in the quest to discern key mediators of resistance and relapse following docetaxel therapy: polyploidization. This process is manifested following docetaxel-mediated mitotic arrest by the appearance of giant, multinucleated cells, which slipped from mitosis without undergoing cytokinesis. Polyploid cells generally possess supernumerary centrosomes, are chromosomally instable, and resist chemotherapy. We thus suspect that chemoresistance and relapse following treatment with docetaxel might be combatted by co-administration of centrosome declustering drugs, which could selectively destroy polyploid cells given that normal cells do not possess amplified centrosomes, an intriguing paradigm that warrants further investigation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. A criticism of the value of midparent in polyploidization.

    Science.gov (United States)

    Gianinetti, A

    2013-11-01

    The hypothesis of genetic additivity states that the effects of different alleles, or different genes, add up to produce the phenotype. When considering the F1 progeny of a cross, the hypothesis of additivity of the genetic dosages provided by the parents is tested against the mid-parent value (MPV), which is the average of parental phenotypes and represents the reference value for genetic additivity. Non-additive effects (genetic interactions) are typically measured as deviations from MPV. Recently, however, the use of MPV has been directly transposed to the study of genetic additivity in newly synthesized plant polyploids, assuming that they should as well display mid-parent expression patterns for additive traits. It is shown here that this direct transposition is incorrect. It is suggested that, in neo-polyploids, mid-parent expression has to be reconsidered in terms of reduced genetic additivity. Homeostatic mechanisms are deemed to be the obvious ones responsible for this effect. Genomes are therefore ruled by negative epistasis, and heterosis in allopolyploids is due to a decreased interaction of the parental repressive systems. It is contended that focalizing on the right perspective has relevant theoretical consequences and makes the studies of neo-polyploids very important for our understanding of how genomes work.

  1. Hepatocytes polyploidization and cell cycle control in liver physiopathology.

    Science.gov (United States)

    Gentric, Géraldine; Desdouets, Chantal; Celton-Morizur, Séverine

    2012-01-01

    Most cells in mammalian tissues usually contain a diploid complement of chromosomes. However, numerous studies have demonstrated a major role of "diploid-polyploid conversion" during physiopathological processes in several tissues. In the liver parenchyma, progressive polyploidization of hepatocytes takes place during postnatal growth. Indeed, at the suckling-weaning transition, cytokinesis failure events induce the genesis of binucleated tetraploid liver cells. Insulin signalling, through regulation of the PI3K/Akt signalling pathway, is essential in the establishment of liver tetraploidization by controlling cytoskeletal organisation and consequently mitosis progression. Liver cell polyploidy is generally considered to indicate terminal differentiation and senescence, and both lead to a progressive loss of cell pluripotency associated to a markedly decreased replication capacity. Although adult liver is a quiescent organ, it retains a capacity to proliferate and to modulate its ploidy in response to various stimuli or aggression (partial hepatectomy, metabolic overload (i.e., high copper and iron hepatic levels), oxidative stress, toxic insult, and chronic hepatitis etc.). Here we review the mechanisms and functional consequences of hepatocytes polyploidization during normal and pathological liver growth.

  2. Sexual polyploidization in plants--cytological mechanisms and molecular regulation.

    Science.gov (United States)

    De Storme, Nico; Geelen, Danny

    2013-05-01

    In the plant kingdom, events of whole genome duplication or polyploidization are generally believed to occur via alterations of the sexual reproduction process. Thereby, diploid pollen and eggs are formed that contain the somatic number of chromosomes rather than the gametophytic number. By participating in fertilization, these so-called 2n gametes generate polyploid offspring and therefore constitute the basis for the establishment of polyploidy in plants. In addition, diplogamete formation, through meiotic restitution, is an essential component of apomixis and also serves as an important mechanism for the restoration of F1 hybrid fertility. Characterization of the cytological mechanisms and molecular factors underlying 2n gamete formation is therefore not only relevant for basic plant biology and evolution, but may also provide valuable cues for agricultural and biotechnological applications (e.g. reverse breeding, clonal seeds). Recent data have provided novel insights into the process of 2n pollen and egg formation and have revealed multiple means to the same end. Here, we summarize the cytological mechanisms and molecular regulatory networks underlying 2n gamete formation, and outline important mitotic and meiotic processes involved in the ectopic induction of sexual polyploidization. © 2013 Ghent University. New Phytologist © 2013 New Phytologist Trust.

  3. Hepatocytes Polyploidization and Cell Cycle Control in Liver Physiopathology

    Directory of Open Access Journals (Sweden)

    Géraldine Gentric

    2012-01-01

    Full Text Available Most cells in mammalian tissues usually contain a diploid complement of chromosomes. However, numerous studies have demonstrated a major role of “diploid-polyploid conversion” during physiopathological processes in several tissues. In the liver parenchyma, progressive polyploidization of hepatocytes takes place during postnatal growth. Indeed, at the suckling-weaning transition, cytokinesis failure events induce the genesis of binucleated tetraploid liver cells. Insulin signalling, through regulation of the PI3K/Akt signalling pathway, is essential in the establishment of liver tetraploidization by controlling cytoskeletal organisation and consequently mitosis progression. Liver cell polyploidy is generally considered to indicate terminal differentiation and senescence, and both lead to a progressive loss of cell pluripotency associated to a markedly decreased replication capacity. Although adult liver is a quiescent organ, it retains a capacity to proliferate and to modulate its ploidy in response to various stimuli or aggression (partial hepatectomy, metabolic overload (i.e., high copper and iron hepatic levels, oxidative stress, toxic insult, and chronic hepatitis etc.. Here we review the mechanisms and functional consequences of hepatocytes polyploidization during normal and pathological liver growth.

  4. Open Spaces and Urban Ecosystem Services. Cooling Effect towards Urban Planning in South American Cities

    Directory of Open Access Journals (Sweden)

    Luis Inostroza

    2014-05-01

    Full Text Available Open space (OS is a key element in the provision of ecosystem services (ES in urban environments. Under a land cover-land use perspective, cities are incorporating into the expansion process to different types of surfaces: sealed, paved surfaces and OS. The first corresponds to a land cover change while the second, which includes bare soil, grass, forest or any other type of non-sealed surface, corresponds to a land use change, without physical transformations. As a land use change OS is able to keep fundamental pre-existing ecological properties. However, besides specific ecological characteristics, the overall capacity to provide ES depends also on the size, number and spatial distribution of OSs within the urban fabric. Those aspects which can determine the very ecological performance of urban ecosystem services (UES are not yet included in the current urban planning in Latin America. OS is still understood mainly as green infrastructure and related mostly with aesthetic and cultural benefits. On the contrary, under an ecological point of view, OS is capable to provide fundamental UES, which can be spatially assessed and analyzed. In this paper the provision of cooling services (CS is assessed in 2 South American cities: Lima and Santiago de Chile. The provision of CS is measured by means of a Remote Sensing-GIS-based method. Two aspects of CS are explored: (1 the current amount of existing OS; and (2 the trend of increasing/reducing CS within the urban tissue, in a dynamic assessment of spatial distribution and rates of OS incorporation to the continuous urban tissue. The aim is to analyze the CS generated by OS in those two cities. The analysis discusses the role of OS in the provision of CS, considering the current urban development trends and planning practice in these specific Latin American cities, highlighting the need to keep unsealed surfaces and increase in trees coverage, to retain the CS provision in certain levels.

  5. The Tetramerium lineage (Acanthaceae: Justicieae) does not support the Pleistocene Arc hypothesis for South American seasonally dry forests.

    Science.gov (United States)

    Côrtes, Ana Luiza A; Rapini, Alessandro; Daniel, Thomas F

    2015-06-01

    The Tetramerium lineage (Acanthaceae) presents a striking ecological structuring in South America, with groups concentrated in moist forests or in seasonally dry forests. In this study, we investigate the circumscription and relationships of the South American genera as a basis for better understanding historic interactions between dry and moist biomes in the Neotropics. We dated the ancestral distribution of the Tetramerium lineage based on one nuclear and four plastid DNA regions. Maximum parsimony, maximum likelihood, and Bayesian inference analyses were performed for this study using 104 terminals. Phylogenetic divergences were dated using a relaxed molecular clock approach and ancestral distributions obtained from dispersal-vicariance analyses. The genera Pachystachys, Schaueria, and Thyrsacanthus are nonmonophyletic. A dry forest lineage dispersed from North America to South America and reached the southwestern part of the continent between the end of the Miocene and beginning of the Pleistocene. This period coincides with the segregation between Amazonian and Atlantic moist forests that established the geographic structure currently found in the group. The South American genera Pachystachys, Schaueria, and Thyrsacanthus need to be recircumscribed. The congruence among biogeographical events found for the Tetramerium lineage suggests that the dry forest centers currently dispersed throughout South America are relatively old remnants, probably isolated since the Neogene, much earlier than the Last Glacial Maximum postulated by the Pleistocene Arc hypothesis. In addition to exploring the Pleistocene Arc hypothesis, this research also informs evolution in a lineage with numerous geographically restricted and threatened species. © 2015 Botanical Society of America, Inc.

  6. Overview of the South American biomass burning analysis (SAMBBA) field experiment

    Science.gov (United States)

    Morgan, W. T.; Allan, J. D.; Flynn, M.; Darbyshire, E.; Hodgson, A.; Johnson, B. T.; Haywood, J. M.; Freitas, S.; Longo, K.; Artaxo, P.; Coe, H.

    2013-05-01

    Biomass burning represents one of the largest sources of particulate matter to the atmosphere, which results in a significant perturbation to the Earth's radiative balance coupled with serious negative impacts on public health. Globally, biomass burning aerosols are thought to exert a small warming effect of 0.03 Wm-2, however the uncertainty is 4 times greater than the central estimate. On regional scales, the impact is substantially greater, particularly in areas such as the Amazon Basin where large, intense and frequent burning occurs on an annual basis for several months (usually from August-October). Furthermore, a growing number of people live within the Amazon region, which means that they are subject to the deleterious effects on their health from exposure to substantial volumes of polluted air. Initial results from the South American Biomass Burning Analysis (SAMBBA) field experiment, which took place during September and October 2012 over Brazil, are presented here. A suite of instrumentation was flown on-board the UK Facility for Airborne Atmospheric Measurement (FAAM) BAe-146 research aircraft and was supported by ground based measurements, with extensive measurements made in Porto Velho, Rondonia. The aircraft sampled a range of conditions with sampling of fresh biomass burning plumes, regional haze and elevated biomass burning layers within the free troposphere. The physical, chemical and optical properties of the aerosols across the region will be characterized in order to establish the impact of biomass burning on regional air quality, weather and climate.

  7. Bluetongue disease and seroprevalence in South American camelids from the northwestern region of the United States.

    Science.gov (United States)

    Allen, Andrew J; Stanton, James B; Evermann, James F; Fry, Lindsay M; Ackerman, Melissa G; Barrington, George M

    2015-03-01

    In late summer/early fall of 2013, 2 South American camelids from central Washington were diagnosed with fatal bluetongue viral disease, an event which is rarely reported. A 9-year-old intact male llama (Lama glama), with a 1-day history of anorexia, recumbency, and dyspnea before death. Abundant foam discharged from the mouth and nostrils, and the lungs were severely edematous on postmortem examination. Histologically, there was abundant intra-alveolar edema with fibrin. Hemorrhage and edema disrupted several other organs. Bluetongue viral RNA was detected by reverse transcription polymerase chain reaction (RT-PCR), and serotype 11 was identified by sequencing a segment of the VP2 outer capsid gene. Approximately 1 month later, at a site 150 miles north of the index case, a 2-year-old female alpaca with similar, acutely progressive clinical signs was reported. A postmortem examination was performed, and histologic lesions from the alpaca were similar to those of the llama, and again serotype 11 was detected by PCR. The occurrence of bluetongue viral infection and disease is described in the context of seasonal Bluetongue virus activity within the northwestern United States and southwestern Canada. © 2015 The Author(s).

  8. The HLA polymorphism of two distinctive South-American Indian tribes: the Kaingang and the Guarani.

    Science.gov (United States)

    Petzl-Erler, M L; Luz, R; Sotomaior, V S

    1993-05-01

    The HLA-A, B, C, DR and DQ antigens of 240 Kaingang and 98 Guarani individuals have been characterized. The most frequent antigens found among the Kaingang are A31, 2, 24; B35, 51, 39, 48; Cw4, 7, 3, 1; DR8, 4, 2; DQ blank, 3. In the Guarani, they are A2, 28, 31; B40, 62, "53G"; Cw3, 4; DR2, 4, 8, 6; DQ3, blank. B " 53G" is an unusual antigen of the B5 cross-reactive group. DQ blank possibly corresponds to DQ4, not tested in this study. The reaction patterns of B35, B40 and DR4 indicate intra-tribal (of B35 and B40), and inter-tribal (DR4, B40 and B35) heterogeneity of these antigens. 408 Kaingang and 141 Guarani haplotypes were defined by segregation analysis. Of the commonest 10 Guarani and 9 Kaingang haplotypes, only one is shared by both tribes. Significant, positive linkage disequilibrium values for HLA-A,B; HLA-A,C; HLA-B,DR and most HLA-B,C antigen pairs were also different for the two populations. Genetic distance estimates between these two and another seven South-American Indian populations, and relative to the major human races (negroids, caucasoids, and mongoloids) reveal a comparatively high degree of divergence between the Kaingang and the Guarani, which is uncommon for Amerindian populations living close one to another.

  9. Speleothem records of changes in the South American Summer Monsoon during MIS stages 5 and 6

    Science.gov (United States)

    Burns, S. J.; Kanner, L.; Cheng, H.; Edwards, R.

    2011-12-01

    Little information exists about the behavior of the South American Summer Monsoon prior to the Last Glacial Period. Speleothems from the Peruvian Altiplano are one possible archive of SASM intensity because oxygen isotopes of rainfall on the Altiplano are primarily controlled by the intensity of rainfall in upstream moisture source region, the Amazon Basin. Here, we present results from a two speleothems collected from Gruta de Huagapo, a cave in the central Peruvian Altiplano (12°S, 76°W, ~3800m elevation). The samples grew from approximately 115-125 ky BP and from 136-168 ky BP, spanning time periods equivalent to much of MIS stage 5e and the transition into MIS 5d and MIS 6. Chronologies were determined by U-Th dating techniques and the dates are in stratigraphic with analytical errors Titicaca (Fritz et al, 2007). At present we have isotopic data from only the youngest 10 ky of the older sample. The values are generally more depleted, with most between -16% and -17%, suggesting an intensified SASM during MIS 6 as compared to 5e. A rapid increase in δ18O occurs at ~136 ky BP. Overall the trends in the data parallel major changes in δD from EPICA, but appear to lead the Antarctic time series by ~2 ky.

  10. Humoral response to 2 inactivated bluetongue virus serotype-8 vaccines in South American camelids.

    Science.gov (United States)

    Zanolari, P; Bruckner, L; Fricker, R; Kaufmann, C; Mudry, M; Griot, C; Meylan, M

    2010-01-01

    Bluetongue virus serotype 8 (BTV-8) has caused disease in domestic ruminants in several countries of northern Europe since 2006. In 2008 a mass-vaccination program was launched in most affected countries using whole virus inactivated vaccines. To evaluate 2 inactivated vaccines (Bovilis BTV 8; BTVPUR AlSap8) for immunogenicity and safety against BTV-8 in South American camelids (SAC) in a field trial. Forty-two SAC (25 Alpacas, 17 Llamas) aged between 1 and 16 years. The animals were vaccinated twice at intervals of 21 days. They were observed clinically for adverse local, systemic, or both reactions throughout the trial. Blood samples collected on days 0, 14, 21, 43, and 156 after vaccination were tested for the presence of BTV-8 virus by real time-polymerase chain reaction and of specific antibodies by competitive ELISA and a serum neutralization test. All vaccinated animals developed antibodies to BTV-8 after the 2nd administration of the vaccine. No adverse effects were observed except for moderate local swellings at the injection site, which disappeared within 21 days. Slightly increased body temperatures were only observed in the first 2 days after vaccination. The BTV was not detected in any of the samples analyzed. The administration of the 2 inactivated commercial vaccines was safe and induced seroconversion against BTV-8 in all vaccinated animals. The results of this study suggest that 2 doses injected 3 weeks apart is a suitable vaccination regimen for SAC.

  11. Uncinaria hamiltoni (Nematoda: Ancylostomatidae) in South American sea lions, Otaria flavescens, from northern Patagonia, Argentina.

    Science.gov (United States)

    Berón-Vera, B; Crespo, E A; Raga, J A; Pedraza, S N

    2004-08-01

    Thirty-one South American sea lion pups (Otaria flavescens) found dead in Punta León, Argentina, during the summer of 2002, were examined for hookworms (Uncinaria hamiltoni). Parasite parameters were analyzed in 2 locations of the rookery, i.e., a traditional, well-structured breeding area and an expanding area with juveniles and a lax social structure. Prevalence of hookworms was 50% in both localities, and no difference was observed in prevalence between pup sexes (P > 0.05). Hookworms were concentrated in the small intestine. Transmammary transmission is assumed because only adult hookworms were found in the pups. The mean intensity of hookworms per pup was 135; the mean intensity in females (92.78) was significantly different (P 0.05) in intensity was found between the 2 breeding areas, although prevalence was higher in the traditional breeding area than in the other area. Location was the only factor affecting hookworm prevalence (P log-linear model: 0.9552; chi2: 1.5629). No apparent trend between body condition and intensity of hookworms was observed.

  12. Centennial-scale solar forcing of the South American Monsoon System recorded in stalagmites.

    Science.gov (United States)

    Novello, Valdir F; Vuille, Mathias; Cruz, Francisco W; Stríkis, Nicolás M; de Paula, Marcos Saito; Edwards, R Lawrence; Cheng, Hai; Karmann, Ivo; Jaqueto, Plínio F; Trindade, Ricardo I F; Hartmann, Gelvam A; Moquet, Jean S

    2016-04-21

    The South American Monsoon System (SAMS) is generally considered to be highly sensitive to Northern Hemisphere (NH) temperature variations on multi-centennial timescales. The direct influence of solar forcing on moisture convergence in global monsoon systems on the other hand, while well explored in modeling studies, has hitherto not been documented in proxy data from the SAMS region. Hence little is known about the sensitivity of the SAMS to solar forcing over the past millennium and how it might compete or constructively interfere with NH temperature variations that occurred primarily in response to volcanic forcing. Here we present a new annually-resolved oxygen isotope record from a 1500-year long stalagmite recording past changes in precipitation in the hitherto unsampled core region of the SAMS. This record details how solar variability consistently modulated the strength of the SAMS on centennial time scales during the past 1500 years. Solar forcing, besides the previously recognized influence from NH temperature changes and associated Intertropical Convergence Zone (ITCZ) shifts, appears as a major driver affecting SAMS intensity at centennial time scales.

  13. Microbial community diversity in the gut of the South American termite Cornitermes cumulans (Isoptera: Termitidae).

    Science.gov (United States)

    Grieco, Maria Angela B; Cavalcante, Janaina J V; Cardoso, Alexander M; Vieira, Ricardo P; Machado, Ednildo A; Clementino, Maysa M; Medeiros, Marcelo N; Albano, Rodolpho M; Garcia, Eloi S; de Souza, Wanderley; Constantino, Reginaldo; Martins, Orlando B

    2013-01-01

    Termites inhabit tropical and subtropical areas where they contribute to structure and composition of soils by efficiently degrading biomass with aid of resident gut microbiota. In this study, culture-independent molecular analysis was performed based on bacterial and archaeal 16S rRNA clone libraries to describe the gut microbial communities within Cornitermes cumulans, a South American litter-feeding termite. Our data reveal extensive bacterial diversity, mainly composed of organisms from the phyla Spirochaetes, Bacteroidetes, Firmicutes, Actinobacteria, and Fibrobacteres. In contrast, a low diversity of archaeal 16S rRNA sequences was found, comprising mainly members of the Crenarchaeota phylum. The diversity of archaeal methanogens was further analyzed by sequencing clones from a library for the mcrA gene, which encodes the enzyme methyl coenzyme reductase, responsible for catalyzing the last step in methane production, methane being an important greenhouse gas. The mcrA sequences were diverse and divided phylogenetically into three clades related to uncultured environmental archaea and methanogens found in different termite species. C. cumulans is a litter-feeding, mound-building termite considered a keystone species in natural ecosystems and also a pest in agriculture. Here, we describe the archaeal and bacterial communities within this termite, revealing for the first time its intriguing microbiota.

  14. Tubulinosema pampeana sp. n. (Microsporidia, Tubulinosematidae), a pathogen of the South American bumble bee Bombus atratus.

    Science.gov (United States)

    Plischuk, Santiago; Sanscrainte, Neil D; Becnel, James J; Estep, Alden S; Lange, Carlos E

    2015-03-01

    An undescribed microsporidium was detected and isolated from the South American bumble bee Bombus atratus collected in the Pampas region of Argentina. Infection intensity in workers averaged 8.2 × 10(7)spores/bee. The main site of infection was adipose tissue where hypertrophy of adipocytes resulted in cyst-like body formation. Mature spores were ovoid and monomorphic. They measured 4.00 μm × 2.37 μm (fresh) or 3.98 μm × 1.88 μm (fixed). All stages were diplokariotic and developed in direct contact with host cytoplasm. Isofilar polar filament was arranged in 16 coils in one or, posteriorly, two layers. Coiling angle was variable, between perpendicular and almost parallel to major spore axis. Late meronts and sporogonial stages were surrounded by vesicles of approximately 60 nm in diameter. Based on both new and already designed primers, a 1827 bp (SSUrRNA, ITS, LSUrRNA) sequence was obtained. Data analyses suggest that this microsporidium is a new species of the genus Tubulinosema. The name Tubulinosema pampeana sp. n. is proposed. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. How Many Parasites Species a Frog Might Have? Determinants of Parasite Diversity in South American Anurans.

    Directory of Open Access Journals (Sweden)

    Karla Magalhães Campião

    Full Text Available There is an increasing interest in unveiling the dynamics of parasite infection. Understanding the interaction patterns, and determinants of host-parasite association contributes to filling knowledge gaps in both community and disease ecology. Despite being targeted as a relevant group for conservation efforts, determinants of the association of amphibians and their parasites in broad scales are poorly understood. Here we describe parasite biodiversity in South American amphibians, testing the influence of host body size and geographic range in helminth parasites species richness (PSR. We also test whether parasite diversity is related to hosts' phylogenetic diversity. Results showed that nematodes are the most common anuran parasites. Host-parasite network has a nested pattern, with specialist helminth taxa generally associated with hosts that harbour the richest parasite faunas. Host size is positively correlated with helminth fauna richness, but we found no support for the association of host geographic range and PSR. These results remained consistent after correcting for uneven study effort and hosts' phylogenic correlation. However, we found no association between host and parasite diversity, indicating that more diversified anuran clades not necessarily support higher parasite diversity. Overall, considering both the structure and the determinants of PRS in anurans, we conclude that specialist parasites are more likely to be associated with large anurans, which are the ones harbouring higher PSR, and that the lack of association of PSR with hosts' clade diversification suggests it is strongly influenced by ecological and contemporary constrains.

  16. Barriers to and Facilitators of South Asian Indian-Americans' Engagement in Advanced Care Planning Behaviors.

    Science.gov (United States)

    Radhakrishnan, Kavita; Saxena, Shubhada; Jillapalli, Regina; Jang, Yuri; Kim, Miyong

    2017-05-01

    To identify barriers to and facilitators of older South Asian Indian-Americans' (SAIAs') engagement in behaviors associated with advance care planning (ACP). Using a descriptive qualitative design guided by the transcultural nursing assessment model, data were collected in focus groups of community-dwelling older SAIA participants, SAIA family caregivers, and SAIA physicians. A directed approach using predetermined coding categories derived from the Transcultural Nursing Assessment model and aided by NVivo 10 software (Melbourne, Australia) facilitated the qualitative data analysis. Eleven focus groups with 36 older SAIAs (61% female, 83% 70+ years old), 10 SAIA family caregivers, and 4 SAIA physicians indicated prior lack of awareness of ACP, good health status, lack of access to linguistically and health literacy-tailored materials, healthcare provider hesitation to initiate discussions on ACP, trust in healthcare providers' or oldest sons' decision making, busy family caregiver work routines, and cultural assumptions about filial piety and after-death rituals as major barriers to engaging in ACP. Introducing ACP using personal anecdotes in a neutral, group-based community setting and incentivizing ACP discussions by including long-term care planning were suggested as facilitators to engage in ACP. The study's findings will guide development of culturally sensitive interventions to raise awareness about ACP among SAIAs and encourage SAIA older adults to engage in ACP. © 2017 Sigma Theta Tau International.

  17. Marine parasites as biological tags in South American Atlantic waters, current status and perspectives.

    Science.gov (United States)

    Cantatore, D M P; Timi, J T

    2015-01-01

    Many marine fisheries in South American Atlantic coasts (SAAC) are threatened by overfishing and under serious risk of collapsing. The SAAC comprises a diversity of environments, possesses a complex oceanography and harbours a vast biodiversity that provide an enormous potential for using parasites as biological tags for fish stock delineation, a prerequisite for the implementation of control and management plans. Here, their use in the SAAC is reviewed. Main evidence is derived from northern Argentine waters, where fish parasite assemblages are dominated by larval helminth species that share a low specificity, long persistence and trophic transmission, parasitizing almost indiscriminately all available fish species. The advantages and constraints of such a combination of characteristics are analysed and recommendations are given for future research. Shifting the focus from fish/parasite populations to communities allows expanding the concept of biological tags from local to regional scales, providing essential information to delineate ecosystem boundaries for host communities. This new concept arose as a powerful tool to help the implementation of ecosystem-based approaches to fisheries management, the new paradigm for fisheries science. Holistic approaches, including parasites as biological tags for stock delineation will render valuable information to help insure fisheries and marine ecosystems against further depletion and collapse.

  18. Primary amebic meningoencephalitis due to Naegleria fowleri in a South American tapir.

    Science.gov (United States)

    Lozano-Alarcón, F; Bradley, G A; Houser, B S; Visvesvara, G S

    1997-05-01

    Naegleria fowleri, Acanthamoeba spp., and Balamuthia mandrillaris are known to cause fatal central nervous system (CNS) disease in human beings. N. fowleri causes acute, fulminating primary amebic meningoencephalitis (PAM), which generally leads to death within 10 days. Acanthamoeba spp. and B. mandrillaris cause chronic granulomatous amebic encephalitis, which may last for 8 weeks. Acanthamoeba spp. and B. mandrillaris also cause CNS disease in animals. N. fowleri, however, has been described only in human beings. This report is the first of PAM in an animal, a South American tapir. Dry cough, lethargy, and coma developed in the animal, and its condition progressed to death. At necropsy, lesions were seen in the cerebrum, cerebellum, and lungs. The CNS had severe, suppurative meningoencephalitis with many neutrophils, fibrin, plasma cells, and amebas. Amebas were 6.5 microns to 9 microns in diameter and had a nucleus containing a large nucleolus. Amebas in the sections reacted with a monoclonal antibody specific for N. fowleri in the immunofluorescent assay and appeared bright green.

  19. Prediction of the burnout performance of some South American coals using a drop-tube furnace

    Energy Technology Data Exchange (ETDEWEB)

    Richelieu Barranco; Michael Cloke; Edward Lester [University of Nottingham, Nottingham (United Kingdom). Fuel Technology Centre, School of Chemical, Environmental and Mining Engineering

    2003-10-01

    An experimental investigation into the combustion burnout behaviour of some South American coals was carried out in a drop-tube furnace. The samples, in two size fractions, were initially pyrolysed at a temperature of 1300{sup o}C, in a 1% of oxygen in nitrogen atmosphere for 200 ms. The re-firing of these pyrolysed chars was performed in the same apparatus, at the same temperature, during 400 ms, in an atmosphere containing 5% of oxygen in nitrogen. The coal samples used in this study were characterised by standard tests along with a specially developed image analysis technique (grey-scale histogram). Data of intrinsic reactivity, morphology, and burnout of the chars were correlated with maceral content of the feed coal by mean of linear regressions. In most cases, the results showed a poor correlation. Subsequently, when the rank of the coals was included in the regressions, the correlations remarkably improved in all cases. When further regressions of char properties with the grey-scale histogram of the coals were carried out, much better correlations were achieved. Therefore, the results indicate that the grey-scale histogram analysis provides a simple and objective technique to predict the combustion behaviour of these coals. 17 refs., 6 figs., 4 tabs.

  20. South American camelid illegal traffic detection by means of molecular markers.

    Science.gov (United States)

    Di Rocco, F; Posik, D M; Ripoli, M V; Díaz, S; Maté, M L; Giovambattista, G; Vidal-Rioja, L

    2011-11-01

    South American camelids comprise the wild species guanaco and vicuña and their respective domestic relatives llama and alpaca. The aim of the present study was to determine by DNA analysis to which of these species belong a herd of camelids confiscated from a llama breeder but alleged to be alpacas by the prosecution, and to evaluate the usefulness of mitochondrial and autosomal DNA markers to solve judicial cases involving camelid taxa. Cytochrome b and cytochrome oxidase I mitochondrial genes and 7 STR were analyzed in 25 confiscated samples. Mitochondrial results were inconclusive because 18 of the sequestered samples presented haplotypes that corresponded to the guanaco haplogroup and the remaining seven belonged to a vicuña linage. Microsatellite data of casework samples and llama reference samples revealed different genetic profiles by the presence of private alleles at two microsatellites suggesting that the confiscated animals could be alpaca, or at least alpaca hybrids instead of pure llama. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Marine debris ingestion by the South American Fur Seal from the Southwest Atlantic Ocean.

    Science.gov (United States)

    Denuncio, Pablo; Mandiola, María Agustina; Pérez Salles, Sofía Belén; Machado, Rodrigo; Ott, Paulo H; De Oliveira, Larissa Rosa; Rodriguez, Diego

    2017-09-15

    In this paper, we examined the ingestion of marine debris (MD) in South American fur seals (SAFS), Arctocephalus australis, found dead in coastal beaches of northern Argentina and southern Brazil. Seven percent of 133 SAFS analyzed presented marine debris in their stomach (n=10), with no differences between sampling countries (Brazil n=7, Argentina n=3) and sexes (female=3; male=6). However, significant differences were observed between ages classes, with MD exclusively present in stomach contents of young specimens. Plastics represents 90% of MD ingested by the SAFS, whereas regarding the source, fishery-related items (e.g. monofilament lines) were the main MD (70%), with a lesser proportion of packaging (e.g. pieces of bags). Low numbers but large size pieces of MD were found in each stomach affected. Negative effects on the individuals could not be fully evaluated. Therefore, the potential impacts of the marine debris to the SAFS deserve further elucidation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Social Identity Integration, Parental Response, and Psychological Outcomes among Lesbian, Gay, Bisexual, and Queer South Asian Americans

    OpenAIRE

    Kishore, Saanjh Aakash

    2015-01-01

    The goal of this study is to understand how social identities are integrated across domains of identity. Focusing on a population in which cultural norms dictate sexuality behaviors as a condition of ethnic membership, the study examines how South Asian LGBQ Americans integrate their ethnic and sexual orientation identities, and also examines the role of this dual social identity integration in the relationship between the distal stress of parental responses to LGBQ identity, the proximal str...

  3. Glacial refugia and the prediction of future habitat coverage of the South American lichen species Ochrolechia austroamericana

    OpenAIRE

    Martin Kukwa; Marta Kolanowska

    2016-01-01

    The biogeographic history of lichenized fungi remains unrevealed because those organisms rarely fossilize due to their delicate, often tiny and quickly rotting thalli. Also the ecology and factors limiting occurrence of numerous taxa, especially those restricted in their distribution to tropical areas are poorly recognized. The aim of this study was to determine localization of glacial refugia of South American Ochrolechia austroamericana and to estimate the future changes in the coverage of ...

  4. PCR-mediated recombination in amplification products derived from polyploid cotton.

    Science.gov (United States)

    Richard C. Cronn; M. Cedroni; T. Haselkorn; C. Grover; Jonathan F. Wendel

    2002-01-01

    PCR recombination describes a process of in vitro chimera formation from non-identical templates. The key requirements of this process is the inclusion of two partially homologous templates in one reaction, a condition met when amplifying any locus from polyploid organisms and members of multigene families from diploid organisms. Because polyploids possess two or more...

  5. Observations of the F-region ionospheric irregularities in the South American sector during the October 2003 "Halloween Storms"

    Directory of Open Access Journals (Sweden)

    Y. Sahai

    2009-12-01

    Full Text Available The response of the ionospheric F-region in the South American sector during the super geomagnetic storms on 29 and 30 October 2003 is studied in the present investigation. In this paper, we present ionospheric sounding observations during the period 29–31 October 2003 obtained at Palmas (a near equatorial location and Sao Jose dos Campos (a location under the southern crest of the equatorial ionospheric anomaly, Brazil, along with observations during the period 27–31 October 2003 from a chain of GPS stations covering the South American sector from Imperatriz, Brazil, to Rio Grande, Argentina. Also, complementary observations that include sequences of all-sky images of the OI 777.4 and 630.0 nm emissions observed at El Leoncito, Argentina, on the nights of 28–29 (geomagnetically quiet night and 29–30 (geomagnetically disturbed night October 2003, and ion densities observed in the South American sector by the DMSP F13, F14 and F15 satellites orbiting at about 800 km on 29 and 30 October 2003 are presented. In addition, global TEC maps derived from GPS observations collected from the global GPS network of International GPS Service (IGS are presented, showing widespread and drastic TEC changes during the different phases of the geomagnetic disturbances. The observations indicate that the equatorial ionospheric irregularities or plasma bubbles extend to the Argentinean station Rawson (geom. Lat. 33.1° S and map at the magnetic equator at an altitude of about 2500 km.

  6. Neotropics and natural ingredients for pharmaceuticals: why isn't South American biodiversity on the crest of the wave?

    Science.gov (United States)

    Desmarchelier, Cristian

    2010-06-01

    Despite the advent of biotechnology and modern methods of combinatorial chemistry and rational drug design, nature still plays a surprisingly important role as a source of new pharmaceutical compounds. These are marketed either as herbal drugs or as single active ingredients. South American tropical ecosystems (or the Neotropics) encompass one-third of the botanical biodiversity of the planet. For centuries, indigenous peoples have been using plants for healing purposes, and scientists are making considerable efforts in order to validate these uses from a pharmacological/phytochemical point of view. However, and despite the unique plant diversity in the region, very few natural pharmaceutical ingredients from this part of the world have reached the markets in industrialized countries. The present review addresses the importance of single active ingredients and herbal drugs from South American flora as natural ingredients for pharmaceuticals; it highlights the most relevant cases in terms of species of interest; and discusses the key entry barriers for these products in industrialized countries. It explores the reasons why, in spite of the region's competitive advantages, South American biodiversity has been a poor source of natural ingredients for the pharmaceutical industry. (c) 2010 John Wiley & Sons, Ltd.

  7. Coexistence and performance of diploid and polyploid Acacia senegal (L.) Willd

    DEFF Research Database (Denmark)

    Diallo, Adja Madjiguene

    ). Sibling relationship among and between trees from the different open pollinated progenies was tested by application of genetic markers to support the quantitative genetic analysis. The results suggested different mating systems in diploid and polyploids, and this complicated the quantitative genetic...... natural sites with different rainfall and salinity showed no simple geographical pattern in the frequency of polyploids. However, salinity was found to be positively correlated with frequency of polyploids. Analysis of population differentiation between cytotypes compared to genetic relationship among...... populations within cytotypes revealed that the studied polyploid populations were more differentiated than diploid ones. The analysis of genetic relationships further suggest multiple origins of polyploid A. senegal and provide novel information for understanding the evolutionary history of the recently...

  8. Understanding the Association of Type 2 Diabetes Mellitus in Breast Cancer Among African American and European American Populations in South Carolina.

    Science.gov (United States)

    Samson, Marsha E; Adams, Swann Arp; Orekoya, Olubunmi; Hebert, James R

    2016-09-01

    In South Carolina, the co-occurrence of diabetes mellitus (DM) and breast cancer (BrCA) is much more prevalent among African American populations than among European American populations. The underlying relationship between diabetes and breast cancer may influence breast cancer survival. The purpose of this investigation is to examine the effect of diabetes on developing breast cancer and to reduce racial disparities in breast cancer outcomes. Study participants included women of European American (EA) and African American (AA) ethnicity from both the Medicaid ICD-9 designations and the South Carolina Central Cancer Registry (SCCCR). A historical prospective cohort design was used to determine the risk of developing breast cancer among women of different ethnicities with and without DM. The chi-square test was used to determine the significance of the association; the logistic model was used to assess the relationship between breast cancer and other factors among EA and AA women. Menopause may have protective properties for AA compared to EA women. AA women have twice the odds of not surviving from each breast cancer stage compared to EA women with respect to their breast cancer stage. Adherence to diabetes medication may contribute to lower breast cancer death in EA. This study illustrates the discrepancy between EA and AA women in terms of breast cancer survival. AA women bear a higher disease burden than EA women. To create ethnic-appropriate public health policies, it is imperative that we understand the effect of comorbidities on breast cancer and how we can prevent them from occurring.

  9. The evaluation of Cu, Zn, Mn, and Se concentrations in the hair of South American camelids

    Directory of Open Access Journals (Sweden)

    Milada Holasová

    2017-01-01

    Full Text Available The aim of this study was to monitor the content of trace elements in the hair of South American camelids and to evaluate the effect of coat colour, species, age, and sex on their concentration in the hair. The samples were collected from 77 animals – 23 llamas (Llama guanicoe f. gllama and 54 alpacas (Llama guanicoe f. pacos during a spring health check. The concentrations of copper (Cu, zinc (Zn, and manganese (Mn were determined by Flame Atomic Absorption Spectrometry and selenium (Se by Hydride Generation Atomic Absorption Spectrometry. We found the following concentrations (mean ± standard deviation; mg/kg dry matter in the llama hair: Cu 9.70 ± 4.69; Zn 145.20 ± 21.07; Mn 12.49 ± 10.14; Se 0.25 ± 0.14. In alpaca hair we found the following concentrations: Cu 10.22 ± 2.90; Zn 129.81 ± 19.01; Mn 12.67 ± 13.85; Se 0.48 ± 0.24. We found a significant difference between llamas and alpacas in Zn and Se concentrations in the hair. From all the evaluated factors we found that coat colour had the highest effect on Mn and Se concentration. Dark haired animals had significantly higher concentrations of these trace elements than other coloured groups. The evaluation of the concentration of trace elements in the hair of llamas has a potential to be used for the evaluation of long-term status of trace elements in the body; however, it is necessary to continue with experimental work in this area. Our findings can serve as a pilot study for further works in this field.

  10. [Dry matter intake of South American camelids and its effects on the composition of feed rations].

    Science.gov (United States)

    Stölzl, Anna Maria; Lambertz, Christian; Moors, Eva; Stiehl, Jennifer; Gauly, Matthias

    2014-01-01

    The number of South American camelids (SAC) is increasing in Germany since decades. Due to a lack of scientifically based publications the knowledge about feeding SACs is still poor. Therefore, the aim of this study was to estimate the dry matter intake (DMI) of SACs as a basis for calculations of feed rations. Previous studies proposed a DMI of up to 3% of the body weight (BW) (Vaughan und Gauly, 2011). In the present study, eight llamas (Llama glama) were allocated to two groups of four animals each. The two groups were fed with hay of different qualities over a total period often weeks, which was divided into two runs of five weeks each. During the first run, group 1 was fed with hay 1 (15.1% crude protein; 8.5% crude ash; 3.1% crude fat; 52.6% NDF per kg DM) and group 2 with hay 2 (6.6% crude protein; 6.2% crude ash; 2.1% crude fat; 64.3% NDF per kg DM). After five weeks the groups were changed and group 1 received hay 2 and group 2 received hay 1. BW was measured at the start and end of each run (week zero, five and ten). The hay quality affected the DMI, but the animals did not compensate a lower feed quality with an increased DMI. The total DMI was 1.26% and 0.89% of the BW for hay 1 and hay 2, respectively, which was lower than expected in both groups. In conclusion, calculations of feed rations for SACs should be adjusted to the present findings of a lower DMI capability.

  11. Efficacy of anthelmintics on South American camelid (llama and alpaca) farms in Georgia.

    Science.gov (United States)

    Gillespie, Rose-Ann M; Williamson, Lisa H; Terrill, Thomas H; Kaplan, Ray M

    2010-08-27

    The number of South American camelid (SAC; llama and alpaca) farms is growing in the southeastern United States, and infection with gastrointestinal nematodes (GIN) is a major health concern in this region. There is widespread resistance to anthelmintic remedies in small ruminants (sheep and goats), but a paucity of information on llamas and alpacas. Anthelmintic resistance was evaluated on three SAC farms (two llama; one alpaca) in Georgia in the southern United States using fecal egg count reduction (FECR) tests. For each farm, animals were randomly assigned to 1 of 5 treatment groups based on initial fecal egg count (FEC) and number of animals available (2-5 groups, n=9-11 per treatment). Ivermectin (IVM, subcutaneous injection; 0.3mg/kg body weight (BW)) and a control group were tested on an alpaca farm, and fenbendazole (FBZ, oral; 10mg/kg BW; two farms), moxidectin (MOX oral; 0.2mg/kg BW; two farms), and levamisole (LEV, oral; 8 mg/kg BW; one farm) were added for the llama farms. Anthelmintic efficacy was determined by comparing FEC of treatment and control animals 14 days post-treatment, with resistance evaluated using the World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines. Based upon these guidelines, there was GIN resistance to IVM in both llamas and alpacas in Georgia and to FBZ on both llama farms where this drug was tested. There was MOX resistance on one llama farm using the FECR test, while there was no resistance to LEV detected in this study. These data demonstrate a serious emerging problem in the United States of llama and alpaca GIN resistant to drugs from two of the three major anthelmintic classes. (c) 2010 Elsevier B.V. All rights reserved.

  12. Experimental infection of South American camelids with bluetongue virus serotype 8.

    Science.gov (United States)

    Schulz, Claudia; Eschbaumer, Michael; Rudolf, Miriam; König, Patricia; Keller, Markus; Bauer, Christian; Gauly, Matthias; Grevelding, Christoph G; Beer, Martin; Hoffmann, Bernd

    2012-01-27

    Bluetongue (BT) is an infectious, non-contagious disease of wild and domestic ruminants. It is caused by bluetongue virus (BTV) and transmitted by Culicoides biting midges. Since 1998, BT has been emerging throughout Europe, threatening not only the naïve ruminant population. Historically, South American camelids (SAC) were considered to be resistant to BT disease. However, recent fatalities related to BTV in captive SAC have raised questions about their role in BTV epidemiology. Data on the susceptibility of SAC to experimental infection with BTV serotype 8 (BTV-8) were collected in an animal experiment. Three alpacas (Vicugna pacos) and three llamas (Lama glama) were experimentally infected with BTV-8. They displayed very mild clinical signs. Seroconversion was first measured 6-8 days after infection (dpi) by ELISA, and neutralising antibodies appeared 10-13 dpi. BTV-8 RNA levels in blood were very low, and quickly cleared after seroconversion. However, spleens collected post-mortem were still positive for BTV RNA, over 71 days after the last detection in blood samples. Virus isolation was only possible from blood samples of two alpacas by inoculation of highly sensitive interferon alpha/beta receptor-deficient (IFNAR(-/-)) mice. An in vitro experiment demonstrated that significantly lower amounts of BTV-8 adsorb to SAC blood cells than to bovine blood cells. Although this experiment showed that SAC are generally susceptible to a BTV-8 infection, it indicates that these species play a negligible role in BTV epidemiology. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Microbial diversity in European and South American spacecraft assembly clean rooms

    Science.gov (United States)

    Moissl-Eichinger, Christine; Stieglmeier, Michaela; Schwendner, Petra

    Spacecraft assembly clean rooms are unique environments for microbes: Due to low nutri-ent levels, desiccated, clean conditions, constant control of humidity and temperature, these environments are quite inhospitable to microbial life and even considered "extreme". Many procedures keep the contamination as low as possible, but these conditions are also highly se-lective for indigenous microbial communities. For space missions under planetary protection requirements, it is crucial to control the contaminating bioburden as much as possible; but for the development of novel cleaning/sterilization methods it is also important to identify and characterize (understand) the present microbial community of spacecraft clean rooms. In prepa-ration for the recently approved ESA ExoMars mission, two European and one South American spacecraft assembly clean rooms were analyzed with respect to their microbial diversity, using standard procedures, new cultivation approaches and molecular methods, that should shed light onto the presence of planetary protection relevant microorganisms. For this study, the Her-schel Space Observatory (launched in May 2009) and its housing clean rooms in Friedrichshafen (Germany), at ESTEC (The Netherlands) and CSG, Kourou (French Guyana) were sampled during assembly, test and launch operations. Although Herschel does not demand planetary protection requirements, all clean rooms were in a fully operating state during sampling. This gave us the opportunity to sample the microbial diversity under strict particulate and molecular contamination-control. Samples were collected from spacecraft and selected clean room surface areas and were subjected to cultivation assays (32 different media), molecular studies (based on 16S rRNA gene sequence analysis) and quantitative PCR. The results from different strategies will be compared and critically discussed, showing the advantages and limits of the selected methodologies. This talk will sum up the lessons

  14. Fast nonlinear gravity inversion in spherical coordinates with application to the South American Moho

    Science.gov (United States)

    Uieda, Leonardo; Barbosa, Valéria C. F.

    2017-01-01

    Estimating the relief of the Moho from gravity data is a computationally intensive nonlinear inverse problem. What is more, the modelling must take the Earths curvature into account when the study area is of regional scale or greater. We present a regularized nonlinear gravity inversion method that has a low computational footprint and employs a spherical Earth approximation. To achieve this, we combine the highly efficient Bott's method with smoothness regularization and a discretization of the anomalous Moho into tesseroids (spherical prisms). The computational efficiency of our method is attained by harnessing the fact that all matrices involved are sparse. The inversion results are controlled by three hyperparameters: the regularization parameter, the anomalous Moho density-contrast, and the reference Moho depth. We estimate the regularization parameter using the method of hold-out cross-validation. Additionally, we estimate the density-contrast and the reference depth using knowledge of the Moho depth at certain points. We apply the proposed method to estimate the Moho depth for the South American continent using satellite gravity data and seismological data. The final Moho model is in accordance with previous gravity-derived models and seismological data. The misfit to the gravity and seismological data is worse in the Andes and best in oceanic areas, central Brazil and Patagonia, and along the Atlantic coast. Similarly to previous results, the model suggests a thinner crust of 30-35 km under the Andean foreland basins. Discrepancies with the seismological data are greatest in the Guyana Shield, the central Solimões and Amazonas Basins, the Paraná Basin, and the Borborema province. These differences suggest the existence of crustal or mantle density anomalies that were unaccounted for during gravity data processing.

  15. Convergent evolution of alternative developmental trajectories associated with diapause in African and South American killifish.

    Science.gov (United States)

    Furness, Andrew I; Reznick, David N; Springer, Mark S; Meredith, Robert W

    2015-03-07

    Annual killifish adapted to life in seasonally ephemeral water-bodies exhibit desiccation resistant eggs that can undergo diapause, a period of developmental arrest, enabling them to traverse the otherwise inhospitable dry season. Environmental cues that potentially indicate the season can govern whether eggs enter a stage of diapause mid-way through development or skip this diapause and instead undergo direct development. We report, based on construction of a supermatrix phylogenetic tree of the order Cyprinodontiformes and a battery of comparative analyses, that the ability to produce diapause eggs evolved independently at least six times within African and South American killifish. We then show in species representative of these lineages that embryos entering diapause display significant reduction in development of the cranial region and circulatory system relative to direct-developing embryos. This divergence along alternative developmental pathways begins mid-way through development, well before diapause is entered, during a period of purported maximum developmental constraint (the phylotypic period). Finally, we show that entering diapause is accompanied by a dramatic reduction in metabolic rate and concomitant increase in long-term embryo survival. Morphological divergence during the phylotypic period thus allows embryos undergoing diapause to conserve energy by shunting resources away from energetically costly organs thereby increasing survival chances in an environment that necessitates remaining dormant, buried in the soil and surrounded by an eggshell for much of the year. Our results indicate that adaptation to seasonal aquatic environments in annual killifish imposes strong selection during the embryo stage leading to marked diversification during this otherwise conserved period of vertebrate development. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  16. Cytogenetic Examination of South American Tapirs, Tapirus Terrestris (Perissodactyla, Tapiridae, from the Wroclaw Zoological Garden

    Directory of Open Access Journals (Sweden)

    Kosowska B.

    2015-12-01

    Full Text Available Cytogenetic Examination of South American Tapirs, Tapirus terrestris (Perissodactyla, Tapiridae from the Wroclaw Zoological Garden. Kosowska, B., Strzała, T., Moska, M., Ratajszczak, R., Dobosz, T. - Seven lowland tapirs (Tapirus terrestris from Wrocław ZOO (three females and four males, differing from each other with exterior and sexual behaviour were verified with cytogenetic analysis in order to check their taxonomic status. Cytogenetic analysis was done using two alternative methods of blood collection: 1 conventionally with venepuncture, and 2 with blood sucking bugs from the Reduviidae family. Lymphocytes capable of growing were obtained only with conventional method of blood sampling. Karyotypes and karyograms of all analyzed tapirs were created using classical cytogenetic methods of chromosomes staining. All possessed karyograms had diploid chromosome number equal 80 (2n = 80. Homologous chromosomes did not differ between each other with quantity, size, centromeres location, length of arms, G bands and all were classified as proper karyograms of Tapirus terrestris species representatives. The X chromosomes as well as the first pair of chromosomes (both metacentric, were the largest among all analyzed, respectively. All remaining 38 pairs of chromosomes were acrocentric with Y chromosome as the smallest one (in males’ karyograms. Blood collected with blood sucking bugs proved to be unsuitable for cell culture. None of the seven established cultures was effective as lymphocytes obtained with this method did not show growth potential in prepared media. Thus, blood collected from the tapirs via Dipetalogaster maxima species did not show usefulness for cytogenetic studies due to the inability of cells to proliferation, even after a relatively short period of time elapsed since the blood sampling (1 to 2 hours.

  17. Community-based game intervention to improve South Asian Indian Americans' engagement with advanced care planning.

    Science.gov (United States)

    Radhakrishnan, Kavita; Van Scoy, Lauren Jodi; Jillapalli, Regina; Saxena, Shubhada; Kim, Miyong T

    2017-07-27

    Advance care planning (ACP) allows individuals to express their preferences for medical treatment in the event that they become incapable of making their own decisions. This study assessed the efficacy of a conversation game intervention for increasing South Asian Indian Americans' (SAIAs') engagement in ACP behaviors as well as the game's acceptability and cultural appropriateness among SAIAs. Eligible community-dwelling SAIAs were recruited at SAIA cultural events held in central Texas during the summer of 2016. Pregame questionnaires included demographics and the 55-item ACP Engagement Survey. Played in groups of 3-5, the game consists of 17 open-ended questions that prompt discussions of end-of-life issues. After each game session, focus groups and questionnaires were used to examine the game's cultural appropriateness and self-rated conversation quality. Postintervention responses on the ACP Engagement Survey and rates of participation in ACP behaviors were collected after 3 months through phone interviews or online surveys. Data were analyzed using descriptive statistics, frequencies, and paired t-tests comparing pre/post averages at a .05 significance level. Of the 47 participants, 64% were female, 62% had graduate degrees, 92% had lived in the U.S. for >10 years, 87% were first-generation immigrants, and 74% had no advance directive prior to the game. At the 3-month follow-up, 58% of participants had completed at least one ACP behavior, 42% had discussed end-of-life issues with loved ones, 15% did so with their healthcare providers, and 18% had created an advanced directive. ACP Engagement Survey scores increased significantly on all four of the process subscales by 3 months postgame. SAIA individuals who played a conversation game had a relatively high rate of performing ACP behaviors 3 months after the intervention. These findings suggest that conversation games may be useful tools for motivating people from minority communities to engage in ACP behaviors.

  18. On-site wildland activity choices among African Americans and White Americans in the rural south: implications for management

    Science.gov (United States)

    Cassandra Y. Johnson; J. Michael Bowker

    1999-01-01

    Johnson and Bowker compare wildland activity choices for a sample of rural African Americans and Whites who visited wildland settings in and around the Apalachicola National Forest. The authors also look at intra-racial (same race, different gender) variations for activity participation. This research extends previous research focused on the visit/not visit wildland...

  19. The identity of three South American “smiliine” treehoppers (Hemiptera: Membracidae) and related taxonomic changes, including description of a new genus in Thuridini

    Science.gov (United States)

    Based on examination of holotype or interpretation of original descriptions, four taxonomic changes are proposed for South American species erroneously placed in the tribe Smiliini: Flynnia, n. gen. (Thuridini) and F. fascipennis (Funkhouser), n. comb. from Bolivia; Antianthe atromarginata (Goding),...

  20. New species of Bidessonotus Régimbart, 1895 with a review of the South American species (Coleoptera, Adephaga, Dytiscidae, Hydroporinae, Bidessini

    Directory of Open Access Journals (Sweden)

    Kelly Miller

    2016-10-01

    Full Text Available The South American species of the New World genus Bidessonotus Régimbart, 1895 are reviewed with descriptions of seven new species. This brings the total number of valid Bidessonotus species to 37, making it the largest Bidessini genus in the New World. The new species are B. annae sp. n. (Venezuela, B. josiahi sp. n. (Venezuela, B. palecephalus sp. n. (Venezuela, B. reductus sp. n. (Venezuela, B. septimus sp. n. (Venezuela, B. spinosus sp. n. (Venezuela, and B. valdezi sp. n. (Guyana, Suriname. New distribution records are provided for many other South American Bidessonotus species. The main diagnostic features of Bidessonotus species are in the male genitalia, and these are illustrated for all South American species. Diagnostic features, distributions (including distribution maps, and additional comments are provided for all South American species.

  1. Ploidy level variability in South American fescues (festuca L., poaceae): use of flow cytometry in up to 5 1/2-year-old caryopses and herbarium specimens.

    Science.gov (United States)

    Smarda, P; Stancík, D

    2006-01-01

    Ploidy levels and chromosome numbers for 24 species of Festuca L. from 29 sites in Bolivia, Colombia, Ecuador and Venezuela are given. The ploidy level of 22 species is reported for the first time. A higher proportion of tetraploids in northern South America and the high frequency of polyploids in the whole continent are documented. In combination with chromosome counts, ploidy level was determined using flow cytometry in 4- to 5 1/2 -year-old herbarium specimens and mature caryopses. Flow cytometric determination from seeds was more reliable than determination from herbarium specimens. In herbarium specimens, the youngest, fresh green leaves, still hidden in sheaths, seem to be most suitable for cytometric determination. In old, brownish leaves, or poorly preserved herbarium specimens, the degradation of DNA signal in flow histograms was documented. DNA content measured in seeds was always higher than that measured in herbarium specimens, which may be caused by the presence of different cytosolic compounds. Differences of about 15% in relative DNA content of F. sodiroana and F. vaginalis was found in simultaneous measurements in seeds.

  2. Coalescent Simulation and Paleodistribution Modeling for Tabebuia rosealba Do Not Support South American Dry Forest Refugia Hypothesis.

    Directory of Open Access Journals (Sweden)

    Warita Alves de Melo

    Full Text Available Studies based on contemporary plant occurrences and pollen fossil records have proposed that the current disjunct distribution of seasonally dry tropical forests (SDTFs across South America is the result of fragmentation of a formerly widespread and continuously distributed dry forest during the arid climatic conditions associated with the Last Glacial Maximum (LGM, which is known as the modern-day dry forest refugia hypothesis. We studied the demographic history of Tabebuia rosealba (Bignoniaceae to understand the disjunct geographic distribution of South American SDTFs based on statistical phylogeography and ecological niche modeling (ENM. We specifically tested the dry forest refugia hypothesis; i.e., if the multiple and isolated patches of SDTFs are current climatic relicts of a widespread and continuously distributed dry forest during the LGM. We sampled 235 individuals across 18 populations in Central Brazil and analyzed the polymorphisms at chloroplast (trnS-trnG, psbA-trnH and ycf6-trnC intergenic spacers and nuclear (ITS nrDNA genomes. We performed coalescence simulations of alternative hypotheses under demographic expectations from two a priori biogeographic hypotheses (1. the Pleistocene Arc hypothesis and, 2. a range shift to Amazon Basin and other two demographic expectances predicted by ENMs (3. expansion throughout the Neotropical South America, including Amazon Basin, and 4. retraction during the LGM. Phylogenetic analyses based on median-joining network showed haplotype sharing among populations with evidence of incomplete lineage sorting. Coalescent analyses showed smaller effective population sizes for T. roseoalba during the LGM compared to the present-day. Simulations and ENM also showed that its current spatial pattern of genetic diversity is most likely due to a scenario of range retraction during the LGM instead of the fragmentation from a once extensive and largely contiguous SDTF across South America, not supporting the

  3. Coalescent Simulation and Paleodistribution Modeling for Tabebuia rosealba Do Not Support South American Dry Forest Refugia Hypothesis.

    Science.gov (United States)

    de Melo, Warita Alves; Lima-Ribeiro, Matheus S; Terribile, Levi Carina; Collevatti, Rosane G

    2016-01-01

    Studies based on contemporary plant occurrences and pollen fossil records have proposed that the current disjunct distribution of seasonally dry tropical forests (SDTFs) across South America is the result of fragmentation of a formerly widespread and continuously distributed dry forest during the arid climatic conditions associated with the Last Glacial Maximum (LGM), which is known as the modern-day dry forest refugia hypothesis. We studied the demographic history of Tabebuia rosealba (Bignoniaceae) to understand the disjunct geographic distribution of South American SDTFs based on statistical phylogeography and ecological niche modeling (ENM). We specifically tested the dry forest refugia hypothesis; i.e., if the multiple and isolated patches of SDTFs are current climatic relicts of a widespread and continuously distributed dry forest during the LGM. We sampled 235 individuals across 18 populations in Central Brazil and analyzed the polymorphisms at chloroplast (trnS-trnG, psbA-trnH and ycf6-trnC intergenic spacers) and nuclear (ITS nrDNA) genomes. We performed coalescence simulations of alternative hypotheses under demographic expectations from two a priori biogeographic hypotheses (1. the Pleistocene Arc hypothesis and, 2. a range shift to Amazon Basin) and other two demographic expectances predicted by ENMs (3. expansion throughout the Neotropical South America, including Amazon Basin, and 4. retraction during the LGM). Phylogenetic analyses based on median-joining network showed haplotype sharing among populations with evidence of incomplete lineage sorting. Coalescent analyses showed smaller effective population sizes for T. roseoalba during the LGM compared to the present-day. Simulations and ENM also showed that its current spatial pattern of genetic diversity is most likely due to a scenario of range retraction during the LGM instead of the fragmentation from a once extensive and largely contiguous SDTF across South America, not supporting the South

  4. Involvement of atypical transcription factor E2F8 in the polyploidization during mouse and human decidualization.

    Science.gov (United States)

    Qi, Qian-Rong; Zhao, Xu-Yu; Zuo, Ru-Juan; Wang, Tong-Song; Gu, Xiao-Wei; Liu, Ji-Long; Yang, Zeng-Ming

    2015-01-01

    Polyploid decidual cells are specifically differentiated cells during mouse uterine decidualization. However, little is known about the regulatory mechanism and physiological significance of polyploidization in pregnancy. Here we report a novel role of E2F8 in the polyploidization of decidual cells in mice. E2F8 is highly expressed in decidual cells and regulated by progesterone through HB-EGF/EGFR/ERK/STAT3 signaling pathway. E2F8 transcriptionally suppresses CDK1, thus triggering the polyploidization of decidual cells. E2F8-mediated polyploidization is a response to stresses which are accompanied by decidualization. Interestingly, polyploidization is not detected during human decidualization with the down-regulation of E2F8, indicating differential expression of E2F8 may lead to the difference of decidual cell polyploidization between mice and humans.

  5. Dinosaur speed demon: the caudal musculature of Carnotaurus sastrei and implications for the evolution of South American abelisaurids.

    Directory of Open Access Journals (Sweden)

    W Scott Persons

    Full Text Available In the South American abelisaurids Carnotaurus sastrei, Aucasaurus garridoi, and, to a lesser extent Skorpiovenator bustingorryi, the anterior caudal ribs project at a high dorsolateral inclination and have interlocking lateral tips. This unique morphology facilitated the expansion of the caudal hypaxial musculature at the expense of the epaxial musculature. Distinct ridges on the ventrolateral surfaces of the caudal ribs of Aucasaurus garridoi are interpreted as attachment scars from the intra caudofemoralis/ilio-ischiocaudalis septa, and confirm that the M. caudofemoralis of advanced South American abelisaurids originated from a portion of the caudal ribs. Digital muscle models indicate that, relative to its overall body size, Carnotaurus sastrei had a substantially larger M. caudofemoralis than any other theropod yet studied. In most non-avian theropods, as in many extant sauropsids, the M. caudofemoralis served as the primary femoral retractor muscle during the locomotive power stroke. This large investment in the M. caudofemoralis suggests that Carnotaurus sastrei had the potential for great cursorial abilities, particularly short-burst sprinting. However, the tightly interlocking morphology of the anterior caudal vertebrae implies a reduced ability to make tight turns. Examination of these vertebral traits in evolutionary context reveals a progressive sequence of increasing caudofemoral mass and tail rigidity among the Abelisauridae of South America.

  6. Comparing Terrestrial Organic Carbon Cycle Dynamics in Interglacial and Glacial Climates in the South American Tropics

    Science.gov (United States)

    Fornace, K. L.; Galy, V.; Hughen, K. A.

    2014-12-01

    The application of compound-specific radiocarbon dating to molecular biomarkers has allowed for tracking of specific organic carbon pools as they move through the environment, providing insight into complex processes within the global carbon cycle. Here we use this technique to investigate links between glacial-interglacial climate change and terrestrial organic carbon cycling in the catchments of Cariaco Basin and Lake Titicaca, two tropical South American sites with well-characterized climate histories since the last glacial period. By comparing radiocarbon ages of terrestrial biomarkers (leaf wax compounds) with deposition ages in late glacial and Holocene sediments, we are able to gauge the storage time of these compounds in the catchments in soils, floodplains, etc. before transport to marine or lacustrine sediments. We are also able to probe the effects of temperature and hydrologic change individually by taking advantage of opposite hydrologic trends at the two sites: while both were colder during the last glacial period, precipitation at Titicaca decreased from the last glacial period to the Holocene, but the late glacial was marked by drier conditions at Cariaco. Preliminary data from both sites show a wide range of apparent ages of long-chain n-fatty acids (within error of 0 to >10,000 years older than sediment), with the majority showing ages on the order of several millennia at time of deposition and age generally increasing with chain length. While late glacial leaf waxes appear to be older relative to sediment than those deposited in the Holocene at both sites, at Cariaco we find a ~2-3 times larger glacial-interglacial age difference than at Titicaca. We hypothesize that at Titicaca the competing influences of wetter and colder conditions during the last glacial period, which respectively tend to increase and decrease the rate of organic carbon turnover on land, served to minimize the contrast between glacial and interglacial leaf wax storage time

  7. Associations between male infertility and ancestry in South Americans: a case control study.

    Science.gov (United States)

    Skowronek, Maria Fernanda; Velazquez, Tatiana; Mut, Patricia; Figueiro, Gonzalo; Sans, Monica; Bertoni, Bernardo; Sapiro, Rossana

    2017-07-26

    Infertility affects 15% of human couples, with men being responsible in approximately 50% of cases. Moreover, the aetiology of male factor infertility is poorly understood. The majority of male factor infertility remains idiopathic and potentially genetic in origin. The association of the Y chromosome and mitochondrial haplogroups with male infertility has been previously reported. This association differs between studied populations and their geographical distributions. These effects have been only rarely analysed in mixed populations, such as South Americans. In this study, we analysed the contributions of the Y chromosome and mitochondrial haplogroups to male infertility in a mixed population. A case control study was conducted. Regular PCR and high-resolutionmelting- real-time PCR were performed to type haplogroups from fertile and infertile men. The sperm parameters from infertile men were compared in each haplogroup by logistic regression analysis and ANOVA. The genotyping confirmed the known admixture characteristic of the Uruguayan population. The European paternal contribution was higher than the maternal contribution in both fertile and infertile men. Neither maternal nor paternal ancestry presented differences between the cases and controls. Men belonging to the Y chromosome haplogroup F(xK) more frequently presented with an abnormal sperm morphology than men from other haplogroups. The sperm parameters were not associated with the mitochondrial haplogroups. The data presented in this study showed an association between male infertility and ancestry in the Uruguayan population. Specifically, abnormal sperm morphology was associated with the Y chromosome haplogroup F(xK). Since the Y chromosome lacks recombination, these data suggest that some genes that determine sperm morphology might be inherited in blocks with the region that determines specific haplogroups. However, the possible association between the Y chromosome haplogroup F(xK) and sperm

  8. Science and Technology vs. Defense and Security: Dual Use Consequences, a South American Perspective

    International Nuclear Information System (INIS)

    Espona, M. J.

    2007-01-01

    Nowadays we can say that science and technology are development driven forces in most countries, with some exceptions especially in the Southern Hemisphere. Even though, we have to take into account their link to and impact on defense and security and not only when it comes to WMD but also in the economy and academy areas, both in developed and developing countries. Within this framework, when we analyze the spread of technology and knowledge, it is important to consider: the media where it takes place (e.g. journals, internet, conferences, commercial agreements); which the actors involved are (e.g. scientists, governmental agencies, commercial firms); and the motive why it occurs (e.g. scientific discoveries; commercial exchange; international agreements). Once known all these elements, which vary both intracountry and intercountry, we may have a deep and broad enough framework to consider which policies to take in order to foster scientific and technologic development without collaborating with state and non state WMD programs. Although we already have a legal framework to fight against WMD proliferation and terrorism, the diverse degree of success of such instruments makes it necessary to continue analyzing and debating ways to strengthen them and/or find new ones. Therefore, in this paper we will analyze how the phenomena of science and technology development and spread impacts on defense and security from a South American perspective, taking into account the particular differences among developed and developing countries. Among the primary findings we can mention the existing differences between countries when it comes to the place (military, academic or commercial ones) where the critical science and technology innovative developments take place; the origin of funding (private or governmental); the existence and fulfillment of plans to foster science and technology development; and the scientific community awareness in WMD topics. All these elements have a

  9. The aryl hydrocarbon receptor (AHR) transcription factor regulates megakaryocytic polyploidization.

    Science.gov (United States)

    Lindsey, Stephan; Papoutsakis, Eleftherios T

    2011-02-01

    We propose that the aryl hydrocarbon receptor (AHR) is a novel transcriptional regulator of megakaryopoietic polyploidization. Functional evidence was obtained that AHR impacts in vivo megakaryocytic differentiation and maturation; compared to wild-type mice, AHR-null mice had lower platelet counts, fewer numbers of newly synthesized platelets, increased bleeding times and lower-ploidy megakaryocytes (Mks). AHR mRNA increased 3·6-fold during ex vivo megakaryocytic differentiation, but reduced or remained constant during parallel isogenic granulocytic or erythroid differentiation. We interrogated the role of AHR in megakaryopoiesis using a validated Mk model of megakaryopoiesis, the human megakaryoblastic leukaemia CHRF cell line. Upon CHRF Mk differentiation, AHR mRNA and protein levels increased, AHR protein shifted from the cytoplasm to the nucleus and AHR binding to its consensus DNA binding sequence increased. Protein and mRNA levels of the AHR transcriptional target HES1 also increased. Mk differentiation of CHRF cells where AHR or HES1 was knocked-down using RNAi resulted in lower ploidy distributions and cells that were incapable of reaching ploidy classes ≥16n. AHR knockdown also resulted in increased DNA synthesis of lower ploidy cells, without impacting apoptosis. Together, these data support a role for AHR in Mk polyploidization and in vivo platelet function, and warrant further detailed investigations. © 2011 Blackwell Publishing Ltd.

  10. Wheat hybridization and polyploidization results in deregulation of small RNAs.

    Science.gov (United States)

    Kenan-Eichler, Michal; Leshkowitz, Dena; Tal, Lior; Noor, Elad; Melamed-Bessudo, Cathy; Feldman, Moshe; Levy, Avraham A

    2011-06-01

    Speciation via interspecific or intergeneric hybridization and polyploidization triggers genomic responses involving genetic and epigenetic alterations. Such modifications may be induced by small RNAs, which affect key cellular processes, including gene expression, chromatin structure, cytosine methylation and transposable element (TE) activity. To date, the role of small RNAs in the context of wide hybridization and polyploidization has received little attention. In this work, we performed high-throughput sequencing of small RNAs of parental, intergeneric hybrid, and allopolyploid plants that mimic the genomic changes occurring during bread wheat speciation. We found that the percentage of small RNAs corresponding to miRNAs increased with ploidy level, while the percentage of siRNAs corresponding to TEs decreased. The abundance of most miRNA species was similar to midparent values in the hybrid, with some deviations, as seen in overrepresentation of miR168, in the allopolyploid. In contrast, the number of siRNAs corresponding to TEs strongly decreased upon allopolyploidization, but not upon hybridization. The reduction in corresponding siRNAs, together with decreased CpG methylation, as shown here for the Veju element, represent hallmarks of TE activation. TE-siRNA downregulation in the allopolyploid may contribute to genome destabilization at the initial stages of speciation. This phenomenon is reminiscent of hybrid dysgenesis in Drosophila.

  11. Glacial refugia and the prediction of future habitat coverage of the South American lichen species Ochrolechia austroamericana.

    Science.gov (United States)

    Kukwa, Martin; Kolanowska, Marta

    2016-12-08

    The biogeographic history of lichenized fungi remains unrevealed because those organisms rarely fossilize due to their delicate, often tiny and quickly rotting thalli. Also the ecology and factors limiting occurrence of numerous taxa, especially those restricted in their distribution to tropical areas are poorly recognized. The aim of this study was to determine localization of glacial refugia of South American Ochrolechia austroamericana and to estimate the future changes in the coverage of its habitats using ecological niche modeling tools. The general glacial potential range of the studied species was wider than it is nowadays and its niches coverage decreased by almost 25% since last glacial maximum. The refugial areas were covered by cool and dry grasslands and scrubs and suitable niches in South America were located near the glacier limit. According to our analyses the further climate changes will not significantly influence the distribution of the suitable niches of O. austroamericana.

  12. Spatial and temporal variability of stable isotope composition of precipitation over the south american continent

    Directory of Open Access Journals (Sweden)

    1995-01-01

    centra en el estudio de la variabilidad espacial y temporal de la composición de isótopos estables de la precipitación a escala del continente. En este estudio se examina con cierto detalle la relación aparente entre la composición isotópica de la precipitación en la región y algunos parámetros climáticos tales como la cantidad de precipitación y la temperatura del aire. The International Atomic Energy Agency (IAEA, in collaboration with the World Meteorological Organization (WMO is conducting a world-wide survey of the isotope composition of precipitation. At present, around 60 stations are providing information on the stable isotope composition of precipitation over the South American continent. During the recent years, several national monitoring networks have been initiated (Argentina, Brazil, Chile, Ecuador, Peru. They provide a valuable contribution to the global IAEA/WMO database. The paper is focused on spatial and temporal variability of the stable isotope composition of precipitation, observed over the South American continent. The relationship between isotopic signature of precipitation and climatically relevant parameters, such as surface air temperature or amount of precipitation is discussed in some detail.

  13. [Pathology of South American Camelids: a retrospective study of necropsies at the Institute of Veterinary Pathology, University of Leipzig, Germany].

    Science.gov (United States)

    Theuß, T; Goerigk, D; Rasenberger, S; Starke, A; Schoon, H-A

    2014-01-01

    The number of South American Camelids (New World Camelids) housed in Germany has increased in the recent years. While these species were formerly kept solely in zoological gardens, ever more private and commercial livestock is being established. Compared to indigenous livestock animals, they bear some distinctive differences, particularly in terms of digestive tract anatomy and physiology. Therefore, it is of considerable interest for veterinarians working with South American Camelids to obtain knowledge about the distinguishing features of these animals and the typical diseases affecting them in Germany. For this purpose, the necropsy reports, including the anamnestic data, and their diagnostic usefulness, from 1995 to 2012 were studied retrospectively. Du- ring this period, a total of 233 New World Camelids were examined (195 alpacas and 38 llamas). Anamnestic data of diagnostic usefulness regarding the cause of disease were only submitted in a limited number of cases, because most of the animals died without specific symptoms. The following were the most frequent pathological findings: enteritis (n = 91), gastritis (n = 76), cachexia (n = 73), pneumonia (n = 30), stomatitis (n = 27), azotaemia (n = 22) and anaemia (n = 9). An endoparasitosis occurred in 107 cases and was considered the predominant cause of enteritis. As with indigenous ruminants, llamas and alpacas primarily suffered from diseases of the digestive and respiratory tracts. Other organ systems were affected to a lesser extent. Even in cases with severe alterations in the affected organs, South American Camelids do not show or show too late diagnostically indicative clinical symptoms. Therefore, a detailed clinical examination of these animals is important.

  14. 10-Methyldodecanal, a Novel Attractant Pheromone Produced by Males of the South American Cerambycid Beetle Eburodacrys vittata.

    Directory of Open Access Journals (Sweden)

    Weliton D Silva

    Full Text Available We report the identification, synthesis, and field bioassay of a novel attractant pheromone produced by males of Eburodacrys vittata (Blanchard, a South American cerambycid beetle in the subfamily Cerambycinae. Headspace volatiles from males contained a sex-specific compound, identified as 10-methyldodecanal. In a field bioassay conducted in Brazil, significant numbers of males and females were caught in traps baited with synthesized racemic 10-methyldodecanal, consistent with the aggregation-sex pheromones produced by males of many cerambycine species. This compound represents a new structural class of cerambycid pheromones, and it is the first pheromone identified for a species in the tribe Eburiini.

  15. The South American species of Hibiscus sect. Furcaria DC. (Malvaceae-Hibisceae

    Directory of Open Access Journals (Sweden)

    Antonio Krapovickas

    2004-01-01

    Full Text Available The Hibiscus section Furcaria from South America is revised. Ten new species from Brasil are described: H. Andersonii, H. capitalensis, H. chapadensis, H. Gregoryi, H. Hochreutineri, H. itirapinensis, H. matogrossensis, H. Nanuzae, H. Saddii, H. Windischii, and a new one from Perú: H. Chancoae. Two new names are proposed: H. Hilarianus from Brasil and H. amambayensis from Paraguay. A key is provided to distinguish the 40 species of section Furcaria known from South America

  16. Obesity is associated with breast cancer in African-American women but not Hispanic women in South Los Angeles.

    Science.gov (United States)

    Sarkissyan, Marianna; Wu, Yanyuan; Vadgama, Jaydutt V

    2011-08-15

    Obesity is considered a risk factor for breast cancer. Modifying life styles that reduce obesity offers the potential for prevention and improved outcomes from cancer. The effects of obesity and breast cancer among African-American women and Hispanic women have been explored in a limited number of studies. The objective of the current study was to investigate the association of obesity with breast cancer in a minority cohort. This was a cross-sectional study of 471 African-American and Hispanic women with and without breast cancer in South Los Angeles. Data regarding body mass index (BMI) and clinical factors were obtained by medical record abstraction. Data were assessed using logistic regression with multivariate analysis. Kaplan-Meier survival analysis was used to assess disease-free survival. Women with breast cancer were more likely to be obese (BMI >30 kg/m(2)) than women without breast cancer (odds ratio [OR], 2.0; P = .01). There was a significant association of being overweight or obese and breast cancer among postmenopausal women (OR, 2.3 [P = .03] and 2.9 [P obesity and breast cancer was significant only among African-American women (OR, 2.70; P American women (OR, 4.8; P obesity and later disease stage at diagnosis (P = .06). An association also was observed between higher BMI (for cutoff points of both 30 kg/m(2) and 28 kg/m(2)) and poorer disease-free survival (P = .045 and P = .019, respectively). The current data suggested an association between obesity and breast cancer, especially among postmenopausal women and most significantly in the African-American cohort. Copyright © 2011 American Cancer Society.

  17. Assessment of fire emission inventories during the South American Biomass Burning Analysis (SAMBBA experiment

    Directory of Open Access Journals (Sweden)

    G. Pereira

    2016-06-01

    Full Text Available Fires associated with land use and land cover changes release large amounts of aerosols and trace gases into the atmosphere. Although several inventories of biomass burning emissions cover Brazil, there are still considerable uncertainties and differences among them. While most fire emission inventories utilize the parameters of burned area, vegetation fuel load, emission factors, and other parameters to estimate the biomass burned and its associated emissions, several more recent inventories apply an alternative method based on fire radiative power (FRP observations to estimate the amount of biomass burned and the corresponding emissions of trace gases and aerosols. The Brazilian Biomass Burning Emission Model (3BEM and the Fire Inventory from NCAR (FINN are examples of the first, while the Brazilian Biomass Burning Emission Model with FRP assimilation (3BEM_FRP and the Global Fire Assimilation System (GFAS are examples of the latter. These four biomass burning emission inventories were used during the South American Biomass Burning Analysis (SAMBBA field campaign. This paper analyzes and inter-compared them, focusing on eight regions in Brazil and the time period of 1 September–31 October 2012. Aerosol optical thickness (AOT550 nm derived from measurements made by the Moderate Resolution Imaging Spectroradiometer (MODIS operating on board the Terra and Aqua satellites is also applied to assess the inventories' consistency. The daily area-averaged pyrogenic carbon monoxide (CO emission estimates exhibit significant linear correlations (r, p  >  0.05 level, Student t test between 3BEM and FINN and between 3BEM_ FRP and GFAS, with values of 0.86 and 0.85, respectively. These results indicate that emission estimates in this region derived via similar methods tend to agree with one other. However, they differ more from the estimates derived via the alternative approach. The evaluation of MODIS AOT550 nm indicates that model

  18. Phylogenetic correlograms and the evolution of body size in South American owls (Strigiformes

    Directory of Open Access Journals (Sweden)

    José Alexandre Felizola Diniz-Filho

    2000-06-01

    Full Text Available During the last few years, many models have been proposed to link microevolutionary processes to macroevolutionary patterns, defined by comparative data analysis. Among these, Brownian motion and Ornstein-Uhlenbeck (O-U processes have been used to model, respectively, genetic drift or directional selection and stabilizing selection. These models produce different curves of pairwise variance between species against time since divergence, in such a way that different profiles appear in phylogenetic correlograms. We analyzed variation in body length among 19 species of South American owls, by means of phylogenetic correlograms constructed using Moran's I coefficient in four distance classes. Phylogeny among species was based on DNA hybridization. The observed correlogram was then compared with 500 correlograms obtained by simulations of Brownian motion and O-U over the same phylogeny, using discriminant analysis. The observed correlogram indicates a phylogenetic gradient up to 45 mya, when coefficients tend to stabilize, and it is similar to the correlograms produced by the O-U process. This is expected when we consider that body size of organisms is correlated with many ecological and life-history traits and subjected to many constraints that can be modeled by the O-U process, which has been used to describe evolution under stabilizing selection.Nos últimos anos diversos modelos têm sido propostos a fim de realizar inferências sobre processos microevolutivos com base em padrões macroevolutivos obtidos a partir de dados comparativos. Dentre esses, o movimento Browniano e o processo Ornstein-Uhlenbeck (O-U têm sido utilizados para modelar principalmente deriva genética e seleção estabilizadora, respectivamente. Esses modelos produzem curvas diferentes de relação entre variância interespecífica e distância no tempo, de modo que eles podem ser distingüidos com base em correlogramas filogenéticos. Neste trabalho, nós analisamos a varia

  19. Assessment of fire emission inventories during the South American Biomass Burning Analysis (SAMBBA) experiment

    Science.gov (United States)

    Pereira, Gabriel; Siqueira, Ricardo; Rosário, Nilton E.; Longo, Karla L.; Freitas, Saulo R.; Cardozo, Francielle S.; Kaiser, Johannes W.; Wooster, Martin J.

    2016-06-01

    Fires associated with land use and land cover changes release large amounts of aerosols and trace gases into the atmosphere. Although several inventories of biomass burning emissions cover Brazil, there are still considerable uncertainties and differences among them. While most fire emission inventories utilize the parameters of burned area, vegetation fuel load, emission factors, and other parameters to estimate the biomass burned and its associated emissions, several more recent inventories apply an alternative method based on fire radiative power (FRP) observations to estimate the amount of biomass burned and the corresponding emissions of trace gases and aerosols. The Brazilian Biomass Burning Emission Model (3BEM) and the Fire Inventory from NCAR (FINN) are examples of the first, while the Brazilian Biomass Burning Emission Model with FRP assimilation (3BEM_FRP) and the Global Fire Assimilation System (GFAS) are examples of the latter. These four biomass burning emission inventories were used during the South American Biomass Burning Analysis (SAMBBA) field campaign. This paper analyzes and inter-compared them, focusing on eight regions in Brazil and the time period of 1 September-31 October 2012. Aerosol optical thickness (AOT550 nm) derived from measurements made by the Moderate Resolution Imaging Spectroradiometer (MODIS) operating on board the Terra and Aqua satellites is also applied to assess the inventories' consistency. The daily area-averaged pyrogenic carbon monoxide (CO) emission estimates exhibit significant linear correlations (r, p > 0.05 level, Student t test) between 3BEM and FINN and between 3BEM_ FRP and GFAS, with values of 0.86 and 0.85, respectively. These results indicate that emission estimates in this region derived via similar methods tend to agree with one other. However, they differ more from the estimates derived via the alternative approach. The evaluation of MODIS AOT550 nm indicates that model simulation driven by 3BEM and FINN

  20. Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA field experiment

    Directory of Open Access Journals (Sweden)

    J. Brito

    2014-11-01

    Full Text Available This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by biomass burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of biomass burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional biomass burning pollution (average CO mixing ratio of 0.6 ppm, occasionally superimposed by intense (up to 2 ppm of CO, freshly emitted biomass burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during biomass burning (BB events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe, among the highest values described in the literature. We examined the ageing of biomass burning organic aerosol (BBOA using the changes in the H : C and O : C ratios, and found that throughout most of the

  1. Akt1/PKB upregulation leads to vascular smooth muscle cell hypertrophy and polyploidization

    Science.gov (United States)

    Hixon, Mary L.; Muro-Cacho, Carlos; Wagner, Mark W.; Obejero-Paz, Carlos; Millie, Elise; Fujio, Yasushi; Kureishi, Yasuko; Hassold, Terry; Walsh, Kenneth; Gualberto, Antonio

    2000-01-01

    Vascular smooth muscle cells (VSMCs) at capacitance arteries of hypertensive individuals and animals undergo marked age- and blood pressure–dependent polyploidization and hypertrophy. We show here that VSMCs at capacitance arteries of rat models of hypertension display high levels of Akt1/PKB protein and activity. Gene transfer of Akt1 to VSMCs isolated from a normotensive rat strain was sufficient to abrogate the activity of the mitotic spindle cell–cycle checkpoint, promoting polyploidization and hypertrophy. Furthermore, the hypertrophic agent angiotensin II induced VSMC polyploidization in an Akt1-dependent manner. These results demonstrate that Akt1 regulates ploidy levels in VSMCs and contributes to vascular smooth muscle polyploidization and hypertrophy during hypertension. PMID:11032861

  2. Experimental transmission of Sarcocystis speeri Dubey and Lindsay, 1999 from the South American opossum (Didelphis albiventris) to the North American opossum (Didelphis virginiana).

    Science.gov (United States)

    Dubey, J P; Speer, C A; Bowman, D D; Horton, K M; Venturini, C; Venturini, L

    2000-06-01

    Sarcocystis speeri Dubey and Lindsay, 1999 from the South American opossum Didelphis albiventris was successfully transmitted to the North American opossum Didelphis virginiana. Sporocysts from a naturally infected D. albiventris from Argentina were fed to 2 gamma-interferon knockout (KO) mice. The mice were killed 64 and 71 days after sporocyst feeding (DAF). Muscles containing sarcocysts from the KO mouse killed 71 DAF were fed to a captive D. virginiana; this opossum shed sporocysts 11 days after ingesting sarcocysts. Sporocysts from D. virginiana were fed to 9 KO mice and 4 budgerigars (Melopsittacus undulatus). Schizonts, sarcocysts, or both of S. speeri were found in tissues of all 7 KO mice killed 29-85 DAF; 2 mice died 39 and 48 DAF were not necropsied. Sarcocystis stages were not found in tissues of the 4 budgerigars fed S. speeri sporocysts and killed 35 DAE These results indicate that S. speeri is distinct from Sarcocystis falcatula and Sarcocystis neurona, and that S. speeri is present in both D. albiventris and D. virginiana.

  3. A proof of concept study to assess the potential of PCR testing to detect natural Mycobacterium bovis infection in South American camelids.

    Science.gov (United States)

    Crawshaw, Timothy R; Chanter, Jeremy I; McGoldrick, Adrian; Line, Kirsty

    2014-02-07

    Cases of Mycobacterium bovis infection South American camelids have been increasing in Great Britain. Current antemortem immunological tests have some limitations. Cases at post mortem examination frequently show extensive pathology. The feasibility of detecting Mycobacterium bovis DNA in clinical samples was investigated. A sensitive extraction methodology was developed and used on nasal swabs and faeces taken post-mortem to assess the potential for a PCR test to detect Mycobacterium bovis in clinical samples. The gross pathology of the studied South American camelids was scored and a significantly greater proportion of South American camelids with more severe pathology were positive in both the nasal swab and faecal PCR tests. A combination of the nasal swab and faecal PCR tests detected 63.9% of all the South American camelids with pathology that were tested. The results suggest that antemortem diagnosis of Mycobacterium bovis in South American camelids may be possible using a PCR test on clinical samples, however more work is required to determine sensitivity and specificity, and the practicalities of applying the test in the field.

  4. First record of Wolbachia in South American terrestrial isopods: prevalence and diversity in two species of Balloniscus (Crustacea, Oniscidea

    Directory of Open Access Journals (Sweden)

    Mauricio Pereira Almerão

    2012-01-01

    Full Text Available Wolbachia are endosymbiotic bacteria that commonly infect arthropods, inducing certain phenotypes in their hosts. So far, no endemic South American species of terrestrial isopods have been investigated for Wolbachia infection. In this work, populations from two species of Balloniscus (B. sellowii and B. glaber were studied through a diagnostic PCR assay. Fifteen new Wolbachia 16S rDNA sequences were detected. Wolbachia found in both species were generally specific to one population, and five populations hosted two different Wolbachia 16S rDNA sequences. Prevalence was higher in B. glaber than in B. sellowii, but uninfected populations could be found in both species. Wolbachia strains from B. sellowii had a higher genetic variation than those isolated from B. glaber. AMOVA analyses showed that most of the genetic variance was distributed among populations of each species rather than between species, and the phylogenetic analysis suggested that Wolbachia strains from Balloniscus cluster within Supergroup B, but do not form a single monophyletic clade, suggesting multiple infections for this group. Our results highlight the importance of studying Wolbachia prevalence and genetic diversity in Neotropical species and suggest that South American arthropods may harbor a great number of diverse strains, providing an interesting model to investigate the evolution of Wolbachia and its hosts.

  5. Depositional history of sedimentary linear alkylbenzenes (LABs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil)

    International Nuclear Information System (INIS)

    Martins, Cesar C.; Bicego, Marcia C.; Mahiques, Michel M.; Figueira, Rubens C.L.; Tessler, Moyses G.; Montone, Rosalinda C.

    2010-01-01

    This paper reports the reconstruction of the contamination history of a large South American industrial coastal area (Santos Estuary, Brazil) using linear alkylbenzenes (LABs). Three sediment cores were dated by 137 Cs. Concentrations in surficial layers were comparable to the midrange concentrations reported for coastal sediments worldwide. LAB concentrations increased towards the surface, indicating increased waste discharges into the estuary in recent decades. The highest concentration values occurred in the early 1970s, a time of intense industrial activity and marked population growth. The decreased LAB concentration, in the late 1970s was assumed to be the result of the world oil crisis. Treatment of industrial effluents, which began in 1984, was represented by decreased LAB levels. Microbial degradation of LABs may be more intense in the industrial area sediments. The results show that industrial and domestic waste discharges are a historical problem in the area. - The contamination history of a large South American industrial coastal area indicated by molecular indicator of sewage input.

  6. Hematozoa of forest birds in American Samoa - Evidence for a diverse, indigenous parasite fauna from the South Pacific

    Science.gov (United States)

    Atkinson, C.T.; Utzurrum, R.C.; Seamon, J.O.; Savage, Amy F.; Lapointe, D.A.

    2006-01-01

    Introduced avian diseases pose a significant threat to forest birds on isolated island archipelagos, especially where most passerines are endemic and many groups of blood-sucking arthropods are either absent or only recently introduced. We conducted a blood parasite survey of forest birds from the main islands of American Samoa to obtain baseline information about the identity, distribution and prevalence of hematozoan parasites in this island group. We examined Giemsa-stained blood smears from 857 individual birds representing 20 species on Tutuila, Ofu, Olosega, and Ta'u islands. Four hematozoan parasites were identified - Plasmodium circumflexum (1%, 12/857), Trypanosoma avium (4%, 32/857), microfilaria (9%, 76/857), and an Atoxoplasma sp. (parasite infections. Given the central location of American Samoa in the South Pacific, it is likely that avian malaria and other hematozoan parasites are indigenous and widespread at least as far as the central South Pacific. Their natural occurrence may provide some immunological protection to indigenous birds in the event that other closely related parasites are accidentally introduced to the region.

  7. Asymmetric epigenetic modification and elimination of rDNA sequences by polyploidization in wheat.

    Science.gov (United States)

    Guo, Xiang; Han, Fangpu

    2014-11-01

    rRNA genes consist of long tandem repeats clustered on chromosomes, and their products are important functional components of the ribosome. In common wheat (Triticum aestivum), rDNA loci from the A and D genomes were largely lost during the evolutionary process. This biased DNA elimination may be related to asymmetric transcription and epigenetic modifications caused by the polyploid formation. Here, we observed both sets of parental nucleolus organizing regions (NORs) were expressed after hybridization, but asymmetric silencing of one parental NOR was immediately induced by chromosome doubling, and reversing the ploidy status could not reactivate silenced NORs. Furthermore, increased CHG and CHH DNA methylation on promoters was accompanied by asymmetric silencing of NORs. Enrichment of H3K27me3 and H3K9me2 modifications was also observed to be a direct response to increased DNA methylation and transcriptional inactivation of NOR loci. Both A and D genome NOR loci with these modifications started to disappear in the S4 generation and were completely eliminated by the S7 generation in synthetic tetraploid wheat. Our results indicated that asymmetric epigenetic modification and elimination of rDNA sequences between different donor genomes may lead to stable allopolyploid wheat with increased differentiation and diversity. © 2014 American Society of Plant Biologists. All rights reserved.

  8. Polyploidization of rat hepatocytes due to cell fusion under the effect of radiation of different let

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.; Baldychev, A.S.; Smolin, V.A.

    1988-01-01

    The method of flow cytometry was used to study polyploidization of hepatocytes following X-, γ-, and neutron-irradiation. Ionizing radiation was shown to induce cell polyploidization by two different ways: (1) cells and nuclei fusion, and (2) restriction of mitosis after DNA replication. RBE of 14 MeV neutrons with respect to fusion was about 5x10 3 . With neutron irradiation, the densitivity of cells by fusion was not lower than that by chromosome mutations

  9. Polyploidization of rat hepatocytes due to cell fusion under the effect of radiation of different LET

    International Nuclear Information System (INIS)

    Khair, M.; Gil'yano, N.Ya.; Malinovskij, O.V.; Smolin, V.A.

    1991-01-01

    The method of flow cytometry was used to study polyploidization of hepatocytes following X-, γ-, and neutron-irradiation. Ionizing radiation was shown to induce cell polyploidization by two different ways: (1) cells and nuclei fusion, and (2) restriction of mitosis after DNA replication. RBE of 14 MeV neutrons with respect to fusion was about 5x10 3 . With neutron irradiation, the sensitivity of cells by fusion was not lower than that by chromosome mutations. (author). 6 refs., 6 figs

  10. A comparative in silico linear B-cell epitope prediction and characterization for South American and African Trypanosoma vivax strains.

    Science.gov (United States)

    Guedes, Rafael Lucas Muniz; Rodrigues, Carla Monadeli Filgueira; Coatnoan, Nicolas; Cosson, Alain; Cadioli, Fabiano Antonio; Garcia, Herakles Antonio; Gerber, Alexandra Lehmkuhl; Machado, Rosangela Zacarias; Minoprio, Paola Marcella Camargo; Teixeira, Marta Maria Geraldes; de Vasconcelos, Ana Tereza Ribeiro

    2018-02-27

    Trypanosoma vivax is a parasite widespread across Africa and South America. Immunological methods using recombinant antigens have been developed aiming at specific and sensitive detection of infections caused by T. vivax. Here, we sequenced for the first time the transcriptome of a virulent T. vivax strain (Lins), isolated from an outbreak of severe disease in South America (Brazil) and performed a computational integrated analysis of genome, transcriptome and in silico predictions to identify and characterize putative linear B-cell epitopes from African and South American T. vivax. A total of 2278, 3936 and 4062 linear B-cell epitopes were respectively characterized for the transcriptomes of T. vivax LIEM-176 (Venezuela), T. vivax IL1392 (Nigeria) and T. vivax Lins (Brazil) and 4684 for the genome of T. vivax Y486 (Nigeria). The results presented are a valuable theoretical source that may pave the way for highly sensitive and specific diagnostic tools. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Neotropical mammal diversity and the Great American Biotic Interchange: spatial and temporal variation in South America's fossil record

    Science.gov (United States)

    Carrillo, Juan D.; Forasiepi, Analía; Jaramillo, Carlos; Sánchez-Villagra, Marcelo R.

    2015-01-01

    The vast mammal diversity of the Neotropics is the result of a long evolutionary history. During most of the Cenozoic, South America was an island continent with an endemic mammalian fauna. This isolation ceased during the late Neogene after the formation of the Isthmus of Panama, resulting in an event known as the Great American Biotic Interchange (GABI). In this study, we investigate biogeographic patterns in South America, just before or when the first immigrants are recorded and we review the temporal and geographical distribution of fossil mammals during the GABI. We performed a dissimilarity analysis which grouped the faunal assemblages according to their age and their geographic distribution. Our data support the differentiation between tropical and temperate assemblages in South America during the middle and late Miocene. The GABI begins during the late Miocene (~10–7 Ma) and the putative oldest migrations are recorded in the temperate region, where the number of GABI participants rapidly increases after ~5 Ma and this trend continues during the Pleistocene. A sampling bias toward higher latitudes and younger records challenges the study of the temporal and geographic patterns of the GABI. PMID:25601879

  12. Influence of Tertiary paleoenvironmental changes on the diversification of South American mammals: a relaxed molecular clock study within xenarthrans

    Directory of Open Access Journals (Sweden)

    Vizcaíno Sergio F

    2004-04-01

    Full Text Available Abstract Background Comparative genomic data among organisms allow the reconstruction of their phylogenies and evolutionary time scales. Molecular timings have been recently used to suggest that environmental global change have shaped the evolutionary history of diverse terrestrial organisms. Living xenarthrans (armadillos, anteaters and sloths constitute an ideal model for studying the influence of past environmental changes on species diversification. Indeed, extant xenarthran species are relicts from an evolutionary radiation enhanced by their isolation in South America during the Tertiary era, a period for which major climate variations and tectonic events are relatively well documented. Results We applied a Bayesian approach to three nuclear genes in order to relax the molecular clock assumption while accounting for differences in evolutionary dynamics among genes and incorporating paleontological uncertainties. We obtained a molecular time scale for the evolution of extant xenarthrans and other placental mammals. Divergence time estimates provide substantial evidence for contemporaneous diversification events among independent xenarthran lineages. This correlated pattern of diversification might possibly relate to major environmental changes that occurred in South America during the Cenozoic. Conclusions The observed synchronicity between planetary and biological events suggests that global change played a crucial role in shaping the evolutionary history of extant xenarthrans. Our findings open ways to test this hypothesis further in other South American mammalian endemics like hystricognath rodents, platyrrhine primates, and didelphid marsupials.

  13. The Variable Effect of Polyploidization on the Phenotype in Escallonia.

    Science.gov (United States)

    Denaeghel, Hanne E R; Van Laere, Katrijn; Leus, Leen; Lootens, Peter; Van Huylenbroeck, Johan; Van Labeke, Marie-Christine

    2018-01-01

    To induce new variation within the Escallonia genus, chromosome doubling was performed in E. rubra, E. rosea , and E. illinita , three important species within this genus of mainly evergreen woody ornamental species. Obtained tetraploids and diploid controls were analyzed for rooting capacity, leaf and flower characteristics, and plant architecture using image analysis and cold tolerance. In the present study, a breeders' collection of 23 accessions was characterized cytogenetically and described morphologically. All analyzed species and cultivars were diploid (2n = 2x = 24), with exception of E. pendula , a tetraploid. Today, breeding in Escallonia is limited to lucky finds in seedling populations and few efforts in interspecific hybridization. Three selected Escallonia species underwent an in vitro chromosome doubling with both oryzalin and trifluralin applied as either a continuous or shock treatment. The treatments successfully induced polyploids in all three species. Image analysis revealed that tetraploid E. rosea had decreased shoot length (from 3.8 to 1.3 cm), higher circularity and more dense growth habit compared to diploids. No significant changes in cold tolerance were seen. Tetraploid E. illinita did not differ in shoot length, but an increased outgrowth of axillary buds on the main axis led to denser plants. For tetraploid E. rubra , an increase in plant height (from 4.9 to 5.5 cm) was observed together with a large decrease in circularity and density due to a more polar outgrowth of branches on the main axis. E. rubra tetraploids bore larger flowers than diploids and had an increased cold tolerance (from -7.7 to -11.8°C). Leaf width and area of tetraploids increased for both E. illinita and E. rubra , while a decrease was seen in E. rosea genotypes. For all three species, the rooting capacity of the tetraploids did not differ from the diploids. We conclude that the effect of polyploidization on Escallonia was highly variable and species dependent.

  14. Vegetarianism and cardiometabolic disease risk factors: Differences between South Asian and American adults

    Science.gov (United States)

    Jaacks, Lindsay M; Kapoor, Deksha; Singh, Kalpana; Narayan, KM Venkat; Ali, Mohammed K; Kadir, M Masood; Mohan, Viswanathan; Tandon, Nikhil; Prabhakaran, Dorairaj

    2016-01-01

    Background Cardiometabolic diseases are increasing disproportionately in South Asia compared to other regions of the world despite high levels of vegetarianism. This unexpected discordance may be explained by differences in the healthfulness of vegetarian and non-vegetarian diets in South Asia versus the US. Objective (1) To compare the food group intake of vegetarians versus non-vegetarians in South Asia and the US and (2) to evaluate associations between vegetarianism and cardiometabolic disease risk factors (overweight/obesity, central obesity, diabetes, hypertension, high triglycerides, high LDL, low HDL, and high Framingham Heart Score). Design Using cross-sectional data from adults (20–69 years) in South Asia (CARRS 2010–2011; n=15,665) and the US (NHANES 2003–2006; n=2159), adherence to a vegetarian diet was assessed using food propensity questionnaires. Multivariable logistic regression was used to estimate odds ratios and predicted margins (e.g. adjusted prevalence of the outcomes). Results One-third (33.0%; n=4968) of adults in the South Asian sample were vegetarian in contrast to only 2.4% (n=59) in the US sample. Among South Asians, compared with non-vegetarians, vegetarians more frequently ate dairy, legumes, vegetables, fruit, desserts, and fried foods (all pvegetarians, vegetarians more frequently ate legumes, fruit, and whole grains, and less frequently ate refined cereals, desserts, fried foods, fruit juice, and soft drinks (all pvegetarians were slightly less frequently overweight/obese compared to non-vegetarians – 49% (95% CI: 45%, 53%) versus 53% (51%, 56%), respectively – while US vegetarians were considerably less frequently overweight/obese compared to non-vegetarians: 48% (32%, 63%) versus 68% (65%, 70%), respectively. Furthermore, US vegetarians were less likely to exhibit central obesity compared to non-vegetarians: 62% (43%, 78%) versus 78% (76%, 80%), respectively. Conclusions There is greater divergence between vegetarian and

  15. Mutations in BRCA1, BRCA2 and other breast and ovarian cancer susceptibility genes in Central and South American populations.

    Science.gov (United States)

    Jara, Lilian; Morales, Sebastian; de Mayo, Tomas; Gonzalez-Hormazabal, Patricio; Carrasco, Valentina; Godoy, Raul

    2017-10-06

    Breast cancer (BC) is the most common malignancy among women worldwide. A major advance in the understanding of the genetic etiology of BC was the discovery of BRCA1 and BRCA2 (BRCA1/2) genes, which are considered high-penetrance BC genes. In non-carriers of BRCA1/2 mutations, disease susceptibility may be explained of a small number of mutations in BRCA1/2 and a much higher proportion of mutations in ethnicity-specific moderate- and/or low-penetrance genes. In Central and South American populations, studied have focused on analyzing the distribution and prevalence of BRCA1/2 mutations and other susceptibility genes that are scarce in Latin America as compared to North America, Europe, Australia, and Israel. Thus, the aim of this review is to present the current state of knowledge regarding pathogenic BRCA variants and other BC susceptibility genes. We conducted a comprehensive review of 47 studies from 12 countries in Central and South America published between 2002 and 2017 reporting the prevalence and/or spectrum of mutations and pathogenic variants in BRCA1/2 and other BC susceptibility genes. The studies on BRCA1/2 mutations screened a total of 5956 individuals, and studies on susceptibility genes analyzed a combined sample size of 11,578 individuals. To date, a total of 190 different BRCA1/2 pathogenic mutations in Central and South American populations have been reported in the literature. Pathogenic mutations or variants that increase BC risk have been reported in the following genes or genomic regions: ATM, BARD1, CHECK2, FGFR2, GSTM1, MAP3K1, MTHFR, PALB2, RAD51, TOX3, TP53, XRCC1, and 2q35.

  16. RUNX1-induced silencing of non-muscle myosin heavy chain IIB contributes to megakaryocyte polyploidization.

    Science.gov (United States)

    Lordier, Larissa; Bluteau, Dominique; Jalil, Abdelali; Legrand, Céline; Pan, Jiajia; Rameau, Philippe; Jouni, Dima; Bluteau, Olivier; Mercher, Thomas; Leon, Catherine; Gachet, Christian; Debili, Najet; Vainchenker, William; Raslova, Hana; Chang, Yunhua

    2012-03-06

    Megakaryocytes are unique mammalian cells that undergo polyploidization (endomitosis) during differentiation, leading to an increase in cell size and protein production that precedes platelet production. Recent evidence demonstrates that endomitosis is a consequence of a late failure in cytokinesis associated with a contractile ring defect. Here we show that the non-muscle myosin IIB heavy chain (MYH10) is expressed in immature megakaryocytes and specifically localizes in the contractile ring. MYH10 downmodulation by short hairpin RNA increases polyploidization by inhibiting the return of 4N cells to 2N, but other regulators, such as of the G1/S transition, might regulate further polyploidization of the 4N cells. Conversely, re-expression of MYH10 in the megakaryocytes prevents polyploidization and the transition of 2N to 4N cells. During polyploidization, MYH10 expression is repressed by the major megakaryocyte transcription factor RUNX1. Thus, RUNX1-mediated silencing of MYH10 is required for the switch from mitosis to endomitosis, linking polyploidization with megakaryocyte differentiation.

  17. X-ray induced polyploidization in the male germline cells of Poekilocerus pictus (acrididoidea : orthopta)

    International Nuclear Information System (INIS)

    Gururaj, M.E.; Rajasekarasetty, M.R.

    1977-01-01

    After the irradiation of male germline cells of Poekilocerus pictus with 20r, 40r, 80r, 120r doses of X-rays, both first and second meiotic polyploid cells were recovered. While various degrees of polyploidy were encountered in first meiotic cells, second meiotic polyploid cells, second meitoic polyploid cells contained diploid number of half bivalents only. The former never progressed beyond leptotene and showed symptoms of degeneration. Among the latter, a few cells showed either emainingative tendencies like uncoiling and stickiness or failure of cellsted meiosis successfully. It has been shown that the dicentric bridges and/or laggards in anaphase-I interfere with the elongation and regression of the spindle, thereby giving rise to metaphase-II polyploid cells through restitution. The possible role of fragmentation of chromosomes in decreasing the incidence of metaphase-II polyploid cells at higher doses of irradiation and the causes for the differential fate of the first and second meiotic polyploid cells have been discussed. (author)

  18. A decrease in cyclin B1 levels leads to polyploidization in DNA damage-induced senescence.

    Science.gov (United States)

    Kikuchi, Ikue; Nakayama, Yuji; Morinaga, Takao; Fukumoto, Yasunori; Yamaguchi, Naoto

    2010-05-04

    Adriamycin, an anthracycline antibiotic, has been used for the treatment of various types of tumours. Adriamycin induces at least two distinct types of growth repression, such as senescence and apoptosis, in a concentration-dependent manner. Cellular senescence is a condition in which cells are unable to proliferate further, and senescent cells frequently show polyploidy. Although abrogation of cell division is thought to correlate with polyploidization, the mechanisms underlying induction of polyploidization in senescent cells are largely unclear. We wished, therefore, to explore the role of cyclin B1 level in polyploidization of Adriamycin-induced senescent cells. A subcytotoxic concentration of Adriamycin induced polyploid cells having the features of senescence, such as flattened and enlarged cell shape and activated beta-galactosidase activity. In DNA damage-induced senescent cells, the levels of cyclin B1 were transiently increased and subsequently decreased. The decrease in cyclin B1 levels occurred in G2 cells during polyploidization upon treatment with a subcytotoxic concentration of Adriamycin. In contrast, neither polyploidy nor a decrease in cyclin B1 levels was induced by treatment with a cytotoxic concentration of Adriamycin. These results suggest that a decrease in cyclin B1 levels is induced by DNA damage, resulting in polyploidization in DNA damage-induced senescence.

  19. The improvement of nuclear safety regulation : American, European, Japanese, and South Korean experiences

    International Nuclear Information System (INIS)

    Cho, Byung Sun

    2005-01-01

    Key concepts in South Korean nuclear safety regulation are safety and risk. Nuclear regulation in South Korea has required reactor designs and safeguards that reduce the risk of a major accident to less than one in a million reactor-years-a risk supposedly low enough to be acceptable. To data, in South Korean nuclear safety regulation has involved the establishment of many technical standards to enable administration enforcement. In scientific lawsuits in which the legal issue is the validity of specialized technical standards that are used for judge whether a particular nuclear power plant is to be licensed, the concept of uncertainty law is often raised with regard to what extent the examination and judgement by the judicial power affects a discretion made by the administrative office. In other words, the safety standards for nuclear power plants has been adapted as a form of the scientific technical standards widely under the idea of uncertainty law. Thus, the improvement of nuclear safety regulation in South Korea seems to depend on the rational lawmaking and a reasonable, judicial examination of the scientific standards on nuclear safety

  20. First record of Rivulus marmoratus Poey, 1880 From the South American continent (Pisces: Cyprinodontidae)

    NARCIS (Netherlands)

    Taphorn, D.C.

    1980-01-01

    Rivulus marmoratus Poey, 1880 has previously been found only in south Florida, Cuba, the Bahamas, Barbuda, St. Martin and several islands off the Venezuelan coast (Curaçao, Bonaire and Gran Roque) (Hoedeman, 1958; Böhlke & Chaplin, 1968). In September of 1978, one of my students, Mr. Edgard W.

  1. Zoogeographic and Taxonomic status of the South American snake Tachymenis surinamensis (Colubridae)

    NARCIS (Netherlands)

    Myers, C.W.

    1974-01-01

    Introduction Tachymenis is a characteristic genus of colubrid snakes inhabiting extreme western South America, from coastal Peru and Chile east to Bolivia (Walker, 1945; Peters & Orejas-Miranda, 1970). An extralimital species in Brazil, Tachymenis brasiliensis Gomes, was referred to its own genus

  2. Identification of a divergent genotype of equine arteritis virus from South American donkeys.

    Science.gov (United States)

    Rivas, J; Neira, V; Mena, J; Brito, B; Garcia, A; Gutierrez, C; Sandoval, D; Ortega, R

    2017-12-01

    A novel equine arteritis virus (EAV) was isolated and sequenced from feral donkeys in Chile. Phylogenetic analysis indicates that the new virus and South African asinine strains diverged at least 100 years from equine EAV strains. The results indicate that asinine strains belonged to a different EAV genotype. © 2017 Blackwell Verlag GmbH.

  3. Observational evidences on the modulation of the South American Low Level Jet east of the Andes according the ENSO variability

    Directory of Open Access Journals (Sweden)

    G. A. M. Silva

    2009-02-01

    Full Text Available The differences on the phase and wavelength of the quasi-stationary waves over the South America generated by El Niño (EN and La Niña (LN events seem to affect the daily evolution of the South American Low Level Jet east of the Andes (SALLJ. For the austral summer period of 1977–2004 the SALLJ episodes detected according to Bonner criterion 1 show normal to above-normal frequency in EN years, and in LN years the episodes show normal to below-normal frequency.

    During EN and LN years the SALLJ episodes were associated with positive rainfall anomalies over the La Plata Basin, but more intense during LN years. During EN years the increase in the SALLJ cases were associated to intensification of the Subtropical Jet (SJ around 30° S and positive Sea Level Pressure (SLP anomalies over the western equatorial Atlantic and tropical South America, particularly over central Brazil. This favored the intensification of the northeasterly trade winds over the northern continent and it channeled by the Andes mountain to the La Plata Basin region where negative SLP are found. The SALLJ cases identified during the LN events were weaker and less frequent when compared to those for EN years. In this case the SJ was weaker than in EN years and the negative SLP anomalies over the tropical continent contributed to the inversion of the northeasterly trade winds. Also a southerly flow anomaly was generated by the geostrophic balance due to the anomalous blocking over southeast Pacific and the intense cyclonic transient over the southern tip of South America. As result the warm tropical air brought by the SALLJ encounters the cold extratropical air from the southerly winds over the La Plata basin. This configuration can increase the conditional instability over the La Plata basin and may explain the more intense positive rainfall anomalies in SALLJ cases during LN years than in EN years.

  4. Future changes in South American biomass distributions, biome distributions and plant trait spectra is dependent on applied atmospheric forcings.

    Science.gov (United States)

    Langan, Liam; Scheiter, Simon; Higgins, Steven

    2017-04-01

    It remains poorly understood why the position of the forest-savanna biome boundary, in a domain defined by precipitation and temperature, differs in South America, Africa and Australia. Process based Dynamic Global Vegetation Models (DGVMs) are a valuable tool to investigate the determinants of vegetation distributions, however, many DGVMs fail to predict the spatial distribution or indeed presence of the South American savanna biome. Evidence suggests fire plays a significant role in mediating forest-savanna biome boundaries, however, fire alone appear to be insufficient to predict these boundaries in South America. We hypothesize that interactions between precipitation, constraints on tree rooting depth and fire, affect the probability of savanna occurrence and the position of the savanna-forest boundary. We tested our hypotheses at tropical forest and savanna sites in Brazil and Venezuela using a novel DGVM, aDGVM2, which allows plant trait spectra, constrained by trade-offs between traits, to evolve in response to abiotic and biotic conditions. Plant hydraulics is represented by the cohesion-tension theory, this allowed us to explore how soil and plant hydraulics control biome distributions and plant traits. The resulting community trait distributions are emergent properties of model dynamics. We showed that across much of South America the biome state is not determined by climate alone. Interactions between tree rooting depth, fire and precipitation affected the probability of observing a given biome state and the emergent traits of plant communities. Simulations where plant rooting depth varied in space provided the best match to satellite derived biomass estimates and generated biome distributions that reproduced contemporary biome maps well. Future projections showed that biomass distributions, biome distributions and plant trait spectra will change, however, the magnitude of these changes are highly dependent on the applied atmospheric forcings.

  5. Involvement of atypical transcription factor E2F8 in the polyploidization during mouse and human decidualization

    OpenAIRE

    Qi, Qian-Rong; Zhao, Xu-Yu; Zuo, Ru-Juan; Wang, Tong-Song; Gu, Xiao-Wei; Liu, Ji-Long; Yang, Zeng-Ming

    2015-01-01

    Polyploid decidual cells are specifically differentiated cells during mouse uterine decidualization. However, little is known about the regulatory mechanism and physiological significance of polyploidization in pregnancy. Here we report a novel role of E2F8 in the polyploidization of decidual cells in mice. E2F8 is highly expressed in decidual cells and regulated by progesterone through HB-EGF/EGFR/ERK/STAT3 signaling pathway. E2F8 transcriptionally suppresses CDK1, thus triggering the polypl...

  6. Weather regimes in the South American sector and neighbouring oceans during winter

    Energy Technology Data Exchange (ETDEWEB)

    Solman, S.A.; Menendez, C.G. [Centro de Investigaciones del Mar y la Atmosfera (CIMA-CONICET/UBA), Ciudad Universitaria, Buenos Aires (Argentina)

    2003-07-01

    We classified 34 years of winter daily 500 hPa geopotential height patterns over the eastern South Pacific-South America-South Atlantic region using the K-means clustering method. We found a significant classification into five weather regimes (WRs) defined as the most frequent large-scale circulation anomalies: WR1 (trough centred downstream of the Drake Passage), WR2 (trough over the SW Pacific and ridge downstream), WR3 (ridge over the SE Pacific and NW-SE trough downstream), WR4 (trough over the SE Pacific and NW-SE ridge downstream) and WR5 (weak ridge to the west of southern South America). We also analysed their persistence and temporal evolution, including transitions between them and development around onsets and breaks of each regime. The preferred transitions, WR1{yields}WR3{yields}WR2{yields}WR4{yields}WR1 and also WR1{yields}WR3{yields}WR2{yields}WR1, suggest the progression of a Rossby wave-like pattern in which each of the regimes resemble the Pacific-South America modes. Significant influence of the WRs on local climate over Argentina was found. The preferred transitions WR1{yields}WR3 and WR3{yields}WR2 induce sustained cold conditions over Patagonia and over northern Argentina, respectively. The most significant change in precipitation frequency is found for WR3, with wetter conditions over all the analysed regions. Finally, the interannual to interdecadal significant variations in the occurrence of these regimes were discussed. WR1 and WR3 are more frequent and WR2 is less frequent during El Nino, and WR2 and WR5 are more frequent and WR1 is less frequent during La Nina. A significant decrease in WR2 and increase of WR4 and WR5 during the 1970s and early 1980s were found. (orig.)

  7. The tectonic setting of the Caribbean region and the K/T turnover of the South American land-mammal fauna

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz-Jaureguizar, E.; Pascual, R.

    2011-07-01

    According to the fossil record, a biotic interchange of land vertebrates (e.g. booid snakes, dinosaurs and mammals) occurred between the Americas during the Late Cretaceous-Early Palaeocene. The arrival of North American immigrants (particularly marsupials and placental) during the latest Cretaceous-earliest Palaeocene had a profound influence on the composition of the South American mammal communities. During the Late Cretaceous these communities were dominated by native groups of Pangeic lineages, which represented more than 95% of the known genera, but during the Early Palaeocene 70% of South American mammals were derived from North American immigrants that had arrived during the Late Cretaceous-earliest Palaeocene, and by the Late Palaeocene all the South American mammals (with the possible exception of the xenarthrans) were descendants of these North American immigrants. In spite of the fact that no geological evidence is currently available to support the existence of a continuous land connection between the Americas during the Late Cretaceousearly Palaeocene, the fossil record is substantial enough to point to a temporary inter-American connection that permitted the beginning of a land-mammal exchange by the end of the Cretaceous. This interpretation is supported by recent geographic reconstructions of the Caribbean region. (Author)

  8. The South-American distribution and southernmost record of Biomphalaria peregrina—a potential intermediate host of schistosomiasis

    Directory of Open Access Journals (Sweden)

    Alejandra Rumi

    2017-05-01

    Full Text Available Schistosomiasis remains a major parasitic disease, endemic in large parts of South America. Five neotropical species of Biomphalaria have been found to act as intermediate hosts of Schistosoma mansoni in natural populations, while others have been shown to be susceptible in experimental infections, although not found infected in the field. Among these potential intermediate hosts, Biomphalaria peregrina represents the most widespread species in South America, with confirmed occurrence records from Venezuela to northern Patagonia. In this study, we report the southernmost record for the species at the Pinturas River, in southern Patagonia, which finding implies a southward reassessment of the limit for the known species of this genus. The identities of the individuals from this population were confirmed through morphological examination, and by means of two mitochondrial genes, cytochrome oxidase subunit I (COI and 16S-rRNA. With both markers, phylogenetic analyses were conducted in order to compare the genetic background of individuals from the Pinturas River with previously genetically characterized strains of B. peregrina from various South-American locations. In addition, we produced a potential distribution model of B. peregrina in South America and identified the environmental variables that best predict that distribution. The model was estimated through a maximum entropy algorithm and run with occurrence points obtained from several sources, including the scientific literature and international databases, along with climatic and hydrographic variables. Different phylogenetic analyses with either the COI or 16S-rRNA sequences did not conflict, but rather gave very similar topological organizations. Two major groups were identified, with sequences from the Pinturas River grouping together with haplotypes from subtropical and temperate regions. The model developed had a satisfactory performance for the study area. We observed that the areas

  9. Time, Space, and National Belonging in The Namesake: Redrawing South Asian American Citizenship in the Shadow of 9/11

    Directory of Open Access Journals (Sweden)

    Sue Brennan

    2011-03-01

    Full Text Available

    The terms of national belonging after 9/11 for South Asian Americans have taken shape through a vague and depoliticized discourse around ethnic identity, one in which the clichés of multiculturalism and melting-pot nationalism stand in for the specific socioeconomic and historical conditions that helped form the South Asian diaspora in the US. This paper explores the ways in which Jhumpa Lahiri’s novel The Namesake and its cinematic adaptation by filmmaker Mira Nair challenge the erasure of South Asian American citizenship following 9/11. Recounting the journey of a young Bengali graduate student and his wife migrating to the US in the late 1960s, each text speaks back to the erasure of South Asian American citizenship through the materialization of time in space: while Lahiri foregrounds the state itself in producing the rhythms through which immigrants are assimilated into the nation, Nair creates a narrative world in which filmic space materializes many, and often competing, histories, unifying multiple temporalities and histories through the representations of space. I argue that the cinematic adaptation of The Namesake generates a new spatiotemporal state of affairs, one in which the iconography of 9/11 both challenges post-9/11 racial logics and destabilizes the singular, progressive, and institutionalized temporality through which Lahiri writes South Asian American immigrants back into nation.

  10. Phylogenetic Structure of Plant Communities: Are Polyploids Distantly Related to Co-occurring Diploids?

    Directory of Open Access Journals (Sweden)

    Michelle L. Gaynor

    2018-04-01

    Full Text Available Polyploidy is widely acknowledged to have played an important role in the evolution and diversification of vascular plants. However, the influence of genome duplication on population-level dynamics and its cascading effects at the community level remain unclear. In part, this is due to persistent uncertainties over the extent of polyploid phenotypic variation, and the interactions between polyploids and co-occurring species, and highlights the need to integrate polyploid research at the population and community level. Here, we investigate how community-level patterns of phylogenetic relatedness might influence escape from minority cytotype exclusion, a classic population genetics hypothesis about polyploid establishment, and population-level species interactions. Focusing on two plant families in which polyploidy has evolved multiple times, Brassicaceae and Rosaceae, we build upon the hypothesis that the greater allelic and phenotypic diversity of polyploids allow them to successfully inhabit a different geographic range compared to their diploid progenitor and close relatives. Using a phylogenetic framework, we specifically test (1 whether polyploid species are more distantly related to diploids within the same community than co-occurring diploids are to one another, and (2 if polyploid species tend to exhibit greater ecological success than diploids, using species abundance in communities as an indicator of successful establishment. Overall, our results suggest that the effects of genome duplication on community structure are not clear-cut. We find that polyploid species tend to be more distantly related to co-occurring diploids than diploids are to each other. However, we do not find a consistent pattern of polyploid species being more abundant than diploid species, suggesting polyploids are not uniformly more ecologically successful than diploids. While polyploidy appears to have some important influences on species co-occurrence in

  11. Anticommunism as cultural praxis : South Vietnam, war, and refugee memories in the Vietnamese American community

    OpenAIRE

    Vo Dang, Thanh Thuy

    2008-01-01

    In dialogue with new critical scholarship on immigration, refugee, war, and memory studies as well as drawing from the methodologies of cultural studies and ethnography, this dissertation examines "anticommunism" as a set of cultural discourses and practices that shape the past, present, and future of Vietnamese diasporic communities by exploring when, where, and for what purposes South Vietnam emerges in refugee memories. That anticommunism continues to be an important paradigm for Vietnames...

  12. Trends in South American weapons purchases at the beginning of the new millennium

    Directory of Open Access Journals (Sweden)

    Rafael Duarte Villa

    2012-12-01

    Full Text Available In recent years, with some frequency it is heard that Latin America, especially South America, is witnessing the rise of an arms race. Frequent reports in the press and strong statements made by politicians in the region have fueled this fear. At the same time, scholars have also reached to this conclusion, as pointed out by Malamud and Garcia: "The famous arms race in Latin America, led by Venezuela, is no longer just talk."

  13. The youngest South American rhynchocephalian, a survivor of the K/Pg extinction.

    Science.gov (United States)

    Apesteguía, Sebastián; Gómez, Raúl O; Rougier, Guillermo W

    2014-10-07

    Rhynchocephalian lepidosaurs, though once widespread worldwide, are represented today only by the tuatara (Sphenodon) of New Zealand. After their apparent early Cretaceous extinction in Laurasia, they survived in southern continents. In South America, they are represented by different lineages of Late Cretaceous eupropalinal forms until their disappearance by the Cretaceous/Palaeogene (K/Pg) boundary. We describe here the only unambiguous Palaeogene rhynchocephalian from South America; this new taxon is a younger species of the otherwise Late Cretaceous genus Kawasphenodon. Phylogenetic analysis confirms the allocation of the genus to the clade Opisthodontia. The new form from the Palaeogene of Central Patagonia is much smaller than Kawasphenodon expectatus from the Late Cretaceous of Northern Patagonia. The new species shows that at least one group of rhynchocephalians not related to the extant Sphenodon survived in South America beyond the K/Pg extinction event. Furthermore, it adds to other trans-K/Pg ectotherm tetrapod taxa, suggesting that the end-Cretaceous extinction affected Patagonia more benignly than the Laurasian landmasses. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  14. Emissions from pre-Hispanic metallurgy in the South American atmosphere.

    Directory of Open Access Journals (Sweden)

    François De Vleeschouwer

    Full Text Available Metallurgical activities have been undertaken in northern South America (NSA for millennia. However, it is still unknown how far atmospheric emissions from these activities have been transported. Since the timing of metallurgical activities is currently estimated from scarce archaeological discoveries, the availability of reliable and continuous records to refine the timing of past metal deposition in South America is essential, as it provides an alternative to discontinuous archives, as well as evidence for global trace metal transport. We show in a peat record from Tierra del Fuego that anthropogenic metals likely have been emitted into the atmosphere and transported from NSA to southern South America (SSA over the last 4200 yrs. These findings are supported by modern time back-trajectories from NSA to SSA. We further show that apparent anthropogenic Cu and Sb emissions predate any archaeological evidence for metallurgical activities. Lead and Sn were also emitted into the atmosphere as by-products of Inca and Spanish metallurgy, whereas local coal-gold rushes and the industrial revolution contributed to local contamination. We suggest that the onset of pre-Hispanic metallurgical activities is earlier than previously reported from archaeological records and that atmospheric emissions of metals were transported from NSA to SSA.

  15. Emissions from pre-Hispanic metallurgy in the South American atmosphere.

    Science.gov (United States)

    De Vleeschouwer, François; Vanneste, Heleen; Mauquoy, Dmitri; Piotrowska, Natalia; Torrejón, Fernando; Roland, Thomas; Stein, Ariel; Le Roux, Gaël

    2014-01-01

    Metallurgical activities have been undertaken in northern South America (NSA) for millennia. However, it is still unknown how far atmospheric emissions from these activities have been transported. Since the timing of metallurgical activities is currently estimated from scarce archaeological discoveries, the availability of reliable and continuous records to refine the timing of past metal deposition in South America is essential, as it provides an alternative to discontinuous archives, as well as evidence for global trace metal transport. We show in a peat record from Tierra del Fuego that anthropogenic metals likely have been emitted into the atmosphere and transported from NSA to southern South America (SSA) over the last 4200 yrs. These findings are supported by modern time back-trajectories from NSA to SSA. We further show that apparent anthropogenic Cu and Sb emissions predate any archaeological evidence for metallurgical activities. Lead and Sn were also emitted into the atmosphere as by-products of Inca and Spanish metallurgy, whereas local coal-gold rushes and the industrial revolution contributed to local contamination. We suggest that the onset of pre-Hispanic metallurgical activities is earlier than previously reported from archaeological records and that atmospheric emissions of metals were transported from NSA to SSA.

  16. Reproductive habitus, psychosocial health, and birth weight variation in Mexican immigrant and Mexican American women in south Texas.

    Science.gov (United States)

    Fleuriet, K Jill; Sunil, T S

    2015-08-01

    The Latina Paradox, or persistent, unexplained variation in low birth weight rates in recently immigrated Mexican women and the trend toward higher rates in subsequent generations of Mexican American women, is most often attributed to unidentified sociocultural causes. We suggest herein that different disciplinary approaches can be synthesized under the constructs of reproductive habitus and subjective social status to identify influences of sociocultural processes on birth weight. Reproductive habitus are "modes of living the reproductive body, bodily practices, and the creation of new subjects through interactions between people and structures" (Smith-Oka, 2012: 2276). Subjective social status infers comparison of self to others based on community definitions of status or socioeconomic status (Adler 2007). We present results from a prospective study of low-income Mexican immigrant and Mexican American women from south Texas that tested the ability of reproductive habitus and subjective social status to elucidate the Latina Paradox. We hypothesized that reproductive habitus between Mexican immigrant women and Mexican American women inform different subjective social statuses during pregnancy, and different subjective social statuses mediate responses to psychosocial stressors known to correlate with low birth weight. Six hundred thirty-one women were surveyed for psychosocial health, subjective social status, and reproductive histories between 2011 and 2013. Eighty-three women were interviewed between 2012 and 2013 for status during pregnancy, prenatal care practices, and pregnancy narratives and associations. Birth weight was extracted from medical records. Results were mixed. Subjective social status and pregnancy-related anxiety predicted low birth weight in Mexican immigrant but not Mexican American women. Mexican immigrant women had significantly lower subjective social status scores but a distinct reproductive habitus that could explain improved psychosocial

  17. The Dual Role a Buddhist Monk Played in the American South: The Balance between Heritage and Citizenship in the Refugee Community

    OpenAIRE

    Daniel Rhodes

    2016-01-01

    Buddhist Monks in Vietnam struggle with cultural preservation differently from a monk in the U.S. where the forces of acculturation for new arrivals, often refugees, are extraordinarily overwhelming. The author provides a case study examining how Buddhist leaders engage in cultural preservation and community building in the American South. Fusing ideas of Engaged Buddhism and community building, the author will demonstrate how a Buddhist monk is able to navigate the broader American culture a...

  18. Natural Ventilation: A Mitigation Strategy to Reduce Overheating In Buildings under Urban Heat Island Effect in South American Cities

    Science.gov (United States)

    Palme, Massimo; Carrasco, Claudio; Ángel Gálvez, Miguel; Inostroza, Luis

    2017-10-01

    Urban heat island effect often produces an increase of overheating sensation inside of buildings. To evacuate this heat, the current use of air conditioning increases the energy consumption of buildings. As a good alternative, natural ventilation is one of the best strategies to obtain indoor comfort conditions, even in summer season, if buildings and urban designs are appropriated. In this work, the overheating risk of a small house is evaluated in four South American cities: Guayaquil, Lima, Antofagasta and Valparaíso, with and without considering the UHI effect. Then, natural ventilation is assessed in order to understand the capability of this passive strategy to assure comfort inside the house. Results show that an important portion of the indoor heat can be evacuated, however the temperature rising (especially during the night) due to UHI can generate a saturation effect if appropriate technical solutions, like the increase in the air speed that can be obtained with good urban design, are not considered.

  19. Genetic diversity of the movement and coat protein genes of South American isolates of Prunus necrotic ringspot virus.

    Science.gov (United States)

    Fiore, Nicola; Fajardo, Thor V M; Prodan, Simona; Herranz, María Carmen; Aparicio, Frederic; Montealegre, Jaime; Elena, Santiago F; Pallás, Vicente; Sánchez-Navarro, Jesús

    2008-01-01

    Prunus necrotic ringspot virus (PNRSV) is distributed worldwide, but no molecular data have been previously reported from South American isolates. The nucleotide sequences corresponding to the movement (MP) and coat (CP) proteins of 23 isolates of PNRSV from Chile, Brazil, and Uruguay, and from different Prunus species, have been obtained. Phylogenetic analysis performed with full-length MP and CP sequences from all the PNRSV isolates confirmed the clustering of the isolates into the previously reported PV32-I, PV96-II and PE5-III phylogroups. No association was found between specific sequences and host, geographic origin or symptomatology. Comparative analysis showed that both MP and CP have phylogroup-specific amino acids and all of the motifs previously characterized for both proteins. The study of the distribution of synonymous and nonsynonymous changes along both open reading frames revealed that most amino acid sites are under the effect of negative purifying selection.

  20. Food Safety by Using Machine Learning for Automatic Classification of Seeds of the South-American Incanut Plant

    International Nuclear Information System (INIS)

    Lemanzyk, Thomas; Anding, Katharina; Linss, Gerhard; Hernández, Jorge Rodriguez; Theska, René

    2015-01-01

    The following paper deals with the classification of seeds and seed components of the South-American Incanut plant and the modification of a machine to handle this task. Initially the state of the art is being illustrated. The research was executed in Germany and with a relevant part in Peru and Ecuador. Theoretical considerations for the solution of an automatically analysis of the Incanut seeds were specified. The optimization of the analyzing software and the separation unit of the mechanical hardware are carried out with recognition results. In a final step the practical application of the analysis of the Incanut seeds is held on a trial basis and rated on the bases of statistic values

  1. A review of the Mycrocylus ulei Ascomycetes fungus, causative agent of South American rubber-leaf blight

    Directory of Open Access Journals (Sweden)

    Ibonne Aydee García-Romero

    2006-07-01

    Full Text Available The Microcyclus ulei Ascomycetes fungus is the causal agent of south-American leaf blight (SALB, this being one of the most important diseases affecting the natural rubber tree (Hevea brasiliensis in Latina-America and has been responsible for numerous economic losses. This fungus has presented high physiological variability, suggesting its great adaptability. HCN tolerance has been described as being one of the mechanisms associated with its virulence. Resistant Hevea clones have been obtained by genetic improvement; however, the mechanisms associated with this are still not well known. Greater knowledge of this pathogen will lead to developing new control strategies and better understanding of the mechanisms associated with host resistance. Key words: Microcyclus ulei, SALB, Hevea brasiliensis.

  2. A new species of Ascocotyle (Trematoda: Heterophyidae) from the South American sea lion, Otaria flavescens, off Patagonia, Argentina.

    Science.gov (United States)

    Hernández-Orts, Jesús Servando; Montero, Francisco Esteban; Crespo, Enrique Alberto; García, Néstor Aníbal; Raga, Juan Antonio; Aznar, Francisco Javier

    2012-08-01

    We describe a new heterophyid species, Ascocotyle (Ascocotyle) patagoniensis n. sp., based on specimens collected from the intestines of the South American sea lion Otaria flavescens from Patagonia (Argentina). Ascocotyle (A.) patagoniensis n. sp. is distinguished from the other species of the subgenus by the number of circumoral spines, which are arranged in 2 rows of 18 to 23. The new species also differs from the other species in having a gonotyl without papillae. The specimens exhibited the widest seminal receptacle described for a species of this subgenus. Species of the subgenus Ascocotyle usually infect fish-eating birds or mammals in freshwater or brackish habitats. Ascocotyle (A.) patagoniensis n. sp. is the first species of the subgenus described from a marine mammal. However, no metacercariae of Ascocotyle spp. were found in 542 marine teleosts from 20 species collected in the same locality. The life cycle of the marine species from the Ascocotyle -complex infecting pinnipeds remains elusive.

  3. Traditional Healing, Biomedicine and the Treatment of HIV/AIDS: Contrasting South African and Native American Experiences

    Science.gov (United States)

    Flint, Adrian

    2015-01-01

    Traditional healing remains an important aspect of many people’s engagement with healthcare and, in this, responses to the treatment of HIV/AIDS are no different. However, given the gravity of the global HIV/AIDS pandemic, there has been much debate as to the value of traditional healing in this respect. Accordingly, this paper explores the extent to which meaningful accommodation between the biomedical and traditional sectors is possible (and/or even desirable). It does this through a consideration of Native American and South African experiences, looking at how the respective groups, in which medical pluralism is common, have addressed the issue of HIV/AIDS. The paper points to the importance of developing “culturally appropriate” forms of treatment that emphasise complementary rather than adversarial engagement between the traditional and biomedical systems and how policymakers can best facilitate this. PMID:25903057

  4. Traditional Healing, Biomedicine and the Treatment of HIV/AIDS: Contrasting South African and Native American Experiences

    Directory of Open Access Journals (Sweden)

    Adrian Flint

    2015-04-01

    Full Text Available Traditional healing remains an important aspect of many people’s engagement with healthcare and, in this, responses to the treatment of HIV/AIDS are no different. However, given the gravity of the global HIV/AIDS pandemic, there has been much debate as to the value of traditional healing in this respect. Accordingly, this paper explores the extent to which meaningful accommodation between the biomedical and traditional sectors is possible (and/or even desirable. It does this through a consideration of Native American and South African experiences, looking at how the respective groups, in which medical pluralism is common, have addressed the issue of HIV/AIDS. The paper points to the importance of developing “culturally appropriate” forms of treatment that emphasise complementary rather than adversarial engagement between the traditional and biomedical systems and how policymakers can best facilitate this.

  5. Downregulation of an Aim-1 Kinase Couples with Megakaryocytic Polyploidization of Human Hematopoietic Cells

    Science.gov (United States)

    Kawasaki, Akira; Matsumura, Itaru; Miyagawa, Jun-ichiro; Ezoe, Sachiko; Tanaka, Hirokazu; Terada, Yasuhiko; Tatsuka, Masaaki; Machii, Takashi; Miyazaki, Hiroshi; Furukawa, Yusuke; Kanakura, Yuzuru

    2001-01-01

    During the late phase of megakaryopoiesis, megakaryocytes undergo polyploidization, which is characterized by DNA duplication without concomitant cell division. However, it remains unknown by which mechanisms this process occurs. AIM-1 and STK15 belong to the Aurora/increase-in-ploidy (Ipl)1 serine/threonine kinase family and play key roles in mitosis. In a human interleukin-3–dependent cell line, F-36P, the expressions of AIM-1 and STK15 mRNA were specifically observed at G2/M phase of the cell cycle during proliferation. In contrast, the expressions of AIM-1 and STK15 were continuously repressed during megakaryocytic polyploidization of human erythro/megakaryocytic cell lines (F-36P, K562, and CMK) treated with thrombopoietin, activated ras (H-rasG12V), or phorbol ester. Furthermore, their expressions were suppressed during thrombopoietin-induced polyploidization of normal human megakaryocytes. Activation of AIM-1 by the induced expression of AIM-1(wild-type) canceled TPA-induced polyploidization of K562 cells significantly, whereas that of STK15 did not. Moreover, suppression of AIM-1 by the induced expression of AIM-1 (K/R, dominant-negative type) led to polyploidization in 25% of K562 cells, whereas STK15(K/R) showed no effect. Also, the induced expression of AIM-1(K/R) in CMK cells provoked polyploidization up to 32N. These results suggested that downregulation of AIM-1 at M phase may be involved in abortive mitosis and polyploid formation of megakaryocytes. PMID:11266445

  6. Molecular genetic features of polyploidization and aneuploidization reveal unique patterns for genome duplication in diploid Malus.

    Directory of Open Access Journals (Sweden)

    Michael J Considine

    Full Text Available Polyploidization results in genome duplication and is an important step in evolution and speciation. The Malus genome confirmed that this genus was derived through auto-polyploidization, yet the genetic and meiotic mechanisms for polyploidization, particularly for aneuploidization, are unclear in this genus or other woody perennials. In fact the contribution of aneuploidization remains poorly understood throughout Plantae. We add to this knowledge by characterization of eupolyploidization and aneuploidization in 27,542 F₁ seedlings from seven diploid Malus populations using cytology and microsatellite markers. We provide the first evidence that aneuploidy exceeds eupolyploidy in the diploid crosses, suggesting aneuploidization is a leading cause of genome duplication. Gametes from diploid Malus had a unique combinational pattern; ova preserved euploidy exclusively, while spermatozoa presented both euploidy and aneuploidy. All non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for Malus eupolyploidization and aneuploidization. Chromosome segregation pattern among aneuploids was non-uniform, however, certain chromosomes were associated for aneuploidization. This study is the first to provide molecular evidence for the contribution of heterozygous non-reduced gametes to fitness in polyploids and aneuploids. Aneuploidization can increase, while eupolyploidization may decrease genetic diversity in their newly established populations. Auto-triploidization is important for speciation in the extant Malus. The features of Malus polyploidization confer genetic stability and diversity, and present heterozygosity, heterosis and adaptability for evolutionary selection. A protocol using co-dominant markers was proposed for accelerating apple triploid breeding program. A path was postulated for evolution of numerically odd basic chromosomes. The model for Malus derivation was considerably revised

  7. Molecular genetic features of polyploidization and aneuploidization reveal unique patterns for genome duplication in diploid Malus.

    Science.gov (United States)

    Considine, Michael J; Wan, Yizhen; D'Antuono, Mario F; Zhou, Qian; Han, Mingyu; Gao, Hua; Wang, Man

    2012-01-01

    Polyploidization results in genome duplication and is an important step in evolution and speciation. The Malus genome confirmed that this genus was derived through auto-polyploidization, yet the genetic and meiotic mechanisms for polyploidization, particularly for aneuploidization, are unclear in this genus or other woody perennials. In fact the contribution of aneuploidization remains poorly understood throughout Plantae. We add to this knowledge by characterization of eupolyploidization and aneuploidization in 27,542 F₁ seedlings from seven diploid Malus populations using cytology and microsatellite markers. We provide the first evidence that aneuploidy exceeds eupolyploidy in the diploid crosses, suggesting aneuploidization is a leading cause of genome duplication. Gametes from diploid Malus had a unique combinational pattern; ova preserved euploidy exclusively, while spermatozoa presented both euploidy and aneuploidy. All non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for Malus eupolyploidization and aneuploidization. Chromosome segregation pattern among aneuploids was non-uniform, however, certain chromosomes were associated for aneuploidization. This study is the first to provide molecular evidence for the contribution of heterozygous non-reduced gametes to fitness in polyploids and aneuploids. Aneuploidization can increase, while eupolyploidization may decrease genetic diversity in their newly established populations. Auto-triploidization is important for speciation in the extant Malus. The features of Malus polyploidization confer genetic stability and diversity, and present heterozygosity, heterosis and adaptability for evolutionary selection. A protocol using co-dominant markers was proposed for accelerating apple triploid breeding program. A path was postulated for evolution of numerically odd basic chromosomes. The model for Malus derivation was considerably revised. Impacts of

  8. Longitudinal measures of perfluoroalkyl substances (PFAS) in serum of Gullah African Americans in South Carolina: 2003-2013.

    Science.gov (United States)

    Gribble, Matthew O; Bartell, Scott M; Kannan, Kurunthachalam; Wu, Qian; Fair, Patricia A; Kamen, Diane L

    2015-11-01

    Charleston Harbor has elevated concentrations of PFAS in dolphins, but local human exposure data are limited. We sought to describe PFAS serum concentrations' temporal trends among Gullah African American residents of coastal South Carolina. Longitudinal measures of PFAS in blood serum from a Gullah clinical sample, without lupus, were examined using spaghetti plots and visit-to-visit change scores (e.g., differences in concentrations between visits) among the 68 participants with repeated measures available. We also modeled population-level trends among the 71 participants with any data using proportionate percentile models, accounting for clustering through robust standard errors. In a post-hoc analysis we examined heterogeneity of temporal trends by age through mixed-effects models for the log-transformed PFAS compounds. Population concentrations of PFOS dropped approximately 9 (95% CI: 8, 10) percent each year over 2003-2013. This was concordant with individual PFOS trajectories (median PFOS change score -21.7 ng/g wet weight, interquartile range of PFOS change scores: -32.8, -14.9) and reports for other populations over this time period. Several other compounds including PFOA, PFHxS, and PFuNDA also showed a population-level decrease. However, examination of individual trajectories suggested substantial heterogeneity. Post-hoc analyses indicated that PFAS trajectories were heterogeneous by age. Many PFAS compounds are decreasing in a sample of Gullah African Americans from coastal South Carolina. There may be age differences in the elimination kinetics of PFASs. The possible role of age as a modifier of PFAS serum trends merits further research. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Longitudinal measures of perfluoroalkyl substances (PFAS) in serum of Gullah African Americans in South Carolina: 2003–2013

    Science.gov (United States)

    Gribble, Matthew O.; Bartell, Scott M.; Kannan, Kurunthachalam; Wu, Qian; Fair, Patricia A.; Kamen, Diane L.

    2015-01-01

    Background Charleston Harbor has elevated concentrations of PFAS in dolphins, but local human exposure data are limited. Objectives We sought to describe PFAS serum concentrations’ temporal trends among Gullah African American residents of coastal South Carolina. Methods Longitudinal measures of PFAS in blood serum from a Gullah clinical sample, without lupus, were examined using spaghetti plots and visit-to-visit change scores (e.g., differences in concentrations between visits) among the 68 participants with repeated measures available. We also modeled population-level trends among the 71 participants with any data using proportionate percentile models, accounting for clustering through robust standard errors. In a post-hoc analysis we examined heterogeneity of temporal trends by age through mixed-effects models for the log-transformed PFAS compounds. Results Population concentrations of PFOS dropped approximately 9 (95% CI: 8, 10) percent each year over 2003–2013. This was concordant with individual PFOS trajectories (median PFOS change score −21.7 ng/g wet weight, interquartile range of PFOS change scores: −32.8, −14.9) and reports for other populations over this time period. Several other compounds including PFOA, PFHxS, and PFuNDA also showed a population-level decrease. However, examination of individual trajectories suggested substantial heterogeneity. Post-hoc analyses indicated that PFAS trajectories were heterogeneous by age. Conclusions Many PFAS compounds are decreasing in a sample of Gullah African Americans from coastal South Carolina. There may be age differences in the elimination kinetics of PFASs. The possible role of age as a modifier of PFAS serum trends merits further research. PMID:25819541

  10. Hollywood’s First Condemnation of Forced Labour in the American South: ‘Hell’s Highway’ (Rowland Brown, 1932

    Directory of Open Access Journals (Sweden)

    Carmen Guiralt Gomar

    2017-09-01

    Full Text Available The aim of this paper is to study Hell’s Highway (La carretera del infierno, Rowland Brown, RKO, 1932, the first American film to make an on-screen denouncement of the brutality exercised against prisoners sentenced to forced labour on chain gangs in the prison camps of the South of the United States. This is an obscure film that has received very little attention from scholars due to the fact that it was overshadowed by the sensational release of a later film, I Am a Fugitive from a Chain Gang (Soy un fugitivo, Mervyn Le Roy, 1932, produced by Warner Bros. As a result, it is not appreciated that, like the latter film, the film also portrays a true story: the case of Arthur Maillefert, a young inmate who died inside a “sweat box” in June 1932, at the Sunbeam prison camp in Florida. This study will pay particular attention to the filmic representation of these real events and demonstrate the high degree of veracity of the images in the film through a great number of sources and photographs from the era. Unfortunately, it will also confirm that its influence on instigating a reform of the penitentiaries in the South was non-existent.

  11. Thermochronology of the South American platform in the state of Sao Paulo, Brazil, through apatite fission tracks

    International Nuclear Information System (INIS)

    Tello Saenz, C.A.; Hadler Neto, J.C.; Iunes, P.J.; Guedes, S.; Hackspacher, P.C.; Ribeiro, L.F.B.; Paulo, S.R.; Osorio A, A.M.

    2005-01-01

    The fission-track method (FTM) in apatite was applied to 45 samples collected in the Serra da Mantiqueira (Mantiqueira mountain range), the Serra do Mar (Mar mountain range), regions next to these mountain ranges and the coastal region between Ubatuba and Santos in the State of Sao Paulo, Brazil, to study the thermochronology of the South American Platform in southeast Brazil and its influence on Santos and Campos basins. The data presented in this work complement the previously presented data on the same region (Tello Saenz et al., 2003. J. S. Am. Earth Sci. 15, 765-774) with 31 new samples analyzed. The weighted mean of the corrected ages from high Mantiqueira (around 1000m), (121+/-6)Ma, coincides with the South Atlantic opening. The fact that its thermal history starts at a relatively low temperature (∼80 deg. C) suggests that the age of ∼120Ma would be the formation age of Serra da Mantiqueira due to a rapid pulse, in which tracks had no time to be retained at the closure temperature, that is ∼120 deg. C. The Serra do Mar presents a more complicated thermal history, with several reactivations indicated by the changes in the slope of its cooling curve. The thermal histories obtained in the regions next to these mountain ranges are compatible with the results mentioned above. The Santos Basin has unconformities that agree with changes in the slope thermal histories of the studied region

  12. Taxonomic revision of the South American catfish genus Ageneiosus (Siluriformes: Auchenipteridae) with the description of four new species

    Science.gov (United States)

    Ribeiro, Frank R.V.; Rapp Py-Daniel, Lúcia H.; Walsh, Stephen J.

    2017-01-01

    The catfish genus Ageneiosus in the exclusively Neotropical family Auchenipteridae is revised. Species of Ageneiosus are widely distributed in all major South American continental drainages except the São Francisco River basin and small rivers along the Brazilian east coast. The taxonomic revision was based on examination of available type specimens, additional museum material and comparisons of original descriptions. A suite of morphometric, meristic and qualitative characters of internal and external anatomy were used to diagnose valid species and determine synonyms. Thirteen valid species are recognized in the genus Ageneiosus, some of which are widely distributed across South America. Ageneiosus pardalis is the only trans-Andean species in the genus. Ageneiosus polystictus and Ageneiosus uranophthalmus are more widely distributed than previously reported. Ageneiosus marmoratus is a junior synonym of Ageneiosus inermis. Ageneiosus dentatus is a valid species and its name is removed from the synonymy of Ageneiosus ucayalensis. Four new species are described: Ageneiosus akamai, Ageneiosus apiaka, Ageneiosus intrusus and Ageneiosus lineatus, all from the Amazon River basin. A dichotomous key for all 13 valid species of Ageneiosus species is provided.

  13. Analysis of PFAAs in American alligators part 2: Potential dietary exposure of South Carolina hunters from recreationally harvested alligator meat.

    Science.gov (United States)

    Tipton, Jessica J; Guillette, Louis J; Lovelace, Susan; Parrott, Benjamin B; Rainwater, Thomas R; Reiner, Jessica L

    2017-11-01

    Exposure to perfluorinated alkyl acids (PFAAs) has been linked to many harmful health effects including reproductive disorders, developmental delays, and altered liver and kidney function. Most human exposure to environmental contaminants, including PFAAs, occurs through consumption of contaminated food or drinking water. This study uses PFAA data from meat samples collected from recreationally harvested American alligators (Alligator mississippiensis) in South Carolina to assess potential dietary exposure of hunters and their families to PFAAs. Consumption patterns were investigated using intercept surveys of 23 hunters at a wild game meat processor. An exposure scenario using the average consumption frequency, portion size, and median perfluorooctane sulfonic acid (PFOS) concentration in alligator meat from all hunt units found the daily dietary exposure to be 2.11ng/kg body weight per day for an adult human. Dietary PFOS exposure scenarios based on location of harvest suggested the highest daily exposure occurs with alligator meat from the Middle Coastal hunt unit in South Carolina. Although no samples were found to exceed the recommended threshold for no consumption of PFOS found in Minnesota state guidelines, exposure to a mixture of PFAAs found in alligator meat and site-specific exposures based on harvest location should be considered in determining an appropriate guideline for vulnerable populations potentially exposed to PFAAs through consumption of wild alligator meat. Copyright © 2017. Published by Elsevier B.V.

  14. The relationship between shame and perceived biological origins of mental illness among South Asian and white American young adults.

    Science.gov (United States)

    Mokkarala, Sameera; O'Brien, Erin Keely; Siegel, Jason T

    2016-06-01

    Mental illness (MI) affects one in four people in their lifetime and a failure to seek help for MI can have grave consequences. To decrease stigma and increase help seeking, prior campaigns have promoted the biological origins of MI. Even though some research supports the efficacy of this approach, other research does not. We propose cultural differences as a partial explanation for these inconsistent results. The current study assessed ethnic differences in the relationship between perceived causes of MI, shame associated with MI and perceived family support for help seeking. White and South Asian American (SAA) undergraduate students completed an online survey (n = 177). Results indicated that SAAs were significantly more likely than whites to perceive character deficits as the cause of MI. Further, among those who had sought help for MI, ethnic differences emerged in perceptions of MI based on perceived cause. SAAs who believed that MI had biological origins perceived more shame and less family support for seeking help compared to SAAs who believed MI was due to character deficits. The converse was true for whites - those who believed that MI had biological origins perceived less shame and more family support for help seeking compared to whites who believed MI was due to character deficits. The results of the current study illuminate the role that culture plays in perceptions of MI. Further, these results have implications for interventions targeting South Asian populations and for mental health outreach in general.

  15. Bleaching of melanin in the epidermis of South American fur seal and its application on enzyme immunohistochemistry

    Directory of Open Access Journals (Sweden)

    A.P. Silva

    2011-03-01

    Full Text Available The South American fur seal (Arctocephalus australis is an amphibious marine mammal distributed along the Atlantic and Pacific coasts of South America. The species is well adjusted to different habitats due to the morphology of its fin-like members and due to some adaptations in their integumentary system. Immunohistochemical studies are very important to evaluate the mechanisms of skin adaptation due the differential expression of the antigens present in the tissue depending of the region of the body surface. However, its strongly pigmented (melanin epidermis prevents the visualization of the immuno-histochemical chromogens markers. In this study a melanin bleaching method was developed aimed to allow the visualization of the chromogens without interfering in the antigen-antibody affinity for immunohistochemistry. The analysis of PCNA (proliferating cell nuclear antigen index in the epidermis of A. australis by immunohistochemistry with diaminobenzidine (DAB as chromogen was used to test the method. The bleaching of the melanin allowed to obtain the cell proliferation index in epidermis and to avoid false positive results without affecting the immunohistochemical results.

  16. Leaf venation pattern to recognize austral South American medicinal species of "cow's hoof" (Bauhinia L., Fabaceae

    Directory of Open Access Journals (Sweden)

    Renée H. Fortunato

    Full Text Available ABSTRACT The leaves extracts of some species of Bauhinia L. s.l. are consumed to treat diabetes, inflammation, pains and several disorders in traditional medicine in austral South America. Despite its wide use and commercialization, sale is not controlled, and botanical quality of samples is not always adequate because of plant misidentification and adulteration. Here, we characterized leaf vein pattern in nineteen taxa to contribute to the recognition and commercial quality control of plant material commercially available. The vein characters intercostal tertiary and quinternary vein fabric, areole development and shape, free ending veinlet branching and marginal ultimate venation allowed to distinguish the main medicinal species in the region.

  17. Molecular analysis reveals hidden diversity in Zungaro (Siluriformes: Pimelodidade): a genus of giant South American catfish.

    Science.gov (United States)

    Pires, Antonio A; Ramirez, Jorge L; Galetti, Pedro M; Troy, Waldo P; Freitas, Patricia D

    2017-06-01

    The genus Zungaro contains some of the largest catfish in South America. Two valid species are currently recognized: Zungaro jahu, inhabiting the Paraná and Paraguay basins, and Zungaro zungaro, occurring in the Amazonas and Orinoco basins. Analysing Zungaro specimens from the Amazonas, Orinoco, Paraguay and Paraná basins, based on the sequencing of COI and D-loop, we found at least three MOTUs, indicating the existence of hidden diversity within this fish group. Considering the ecological and economic values of this fish, our results are surely welcomed for its conservation, disclosing new findings on its diversity and pointing out the necessity for a detailed taxonomic revision.

  18. Current meter and bathythermograph data from moored current meter and xbt casts in the North American Coastline-South as part of the Outer Continental Shelf - South Atlantic (OCS-South Atlantic) project from 1982-02-16 to 1985-07-01 (NODC Accession 8600124)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction and bathythermograph (xbt) data were collected using moored current meter casts and other instruments in the North American Coastline-South from...

  19. Untangling nucleotide diversity and evolution of the H genome in polyploid Hordeum and Elymus species based on the single copy of nuclear gene DMC1.

    Directory of Open Access Journals (Sweden)

    Dongfa Sun

    Full Text Available Numerous hybrid and polypoid species are found within the Triticeae. It has been suggested that the H subgenome of allopolyploid Elymus (wheatgrass species originated from diploid Hordeum (barley species, but the role of hybridization between polyploid Elymus and Hordeum has not been studied. It is not clear whether gene flow across polyploid Hordeum and Elymus species has occurred following polyploid speciation. Answering these questions will provide new insights into the formation of these polyploid species, and the potential role of gene flow among polyploid species during polyploid evolution. In order to address these questions, disrupted meiotic cDNA1 (DMC1 data from the allopolyploid StH Elymus are analyzed together with diploid and polyploid Hordeum species. Phylogenetic analysis revealed that the H copies of DMC1 sequence in some Elymus are very close to the H copies of DMC1 sequence in some polyploid Hordeum species, indicating either that the H genome in theses Elymus and polyploid Hordeum species originated from same diploid donor or that gene flow has occurred among them. Our analysis also suggested that the H genomes in Elymus species originated from limited gene pool, while H genomes in Hordeum polyploids have originated from broad gene pools. Nucleotide diversity (π of the DMC1 sequences on H genome from polyploid species (π = 0.02083 in Elymus, π = 0.01680 in polyploid Hordeum is higher than that in diploid Hordeum (π = 0.01488. The estimates of Tajima's D were significantly departure from the equilibrium neutral model at this locus in diploid Hordeum species (P<0.05, suggesting an excess of rare variants in diploid species which may not contribute to the origination of polyploids. Nucleotide diversity (π of the DMC1 sequences in Elymus polyploid species (π = 0.02083 is higher than that in polyploid Hordeum (π = 0.01680, suggesting that the degree of relationships between two parents of a polyploid might be a factor

  20. Environmental filtering of eudicot lineages underlies phylogenetic clustering in tropical South American flooded forests.

    Science.gov (United States)

    Aldana, Ana M; Carlucci, Marcos B; Fine, Paul V A; Stevenson, Pablo R

    2017-02-01

    The phylogenetic community assembly approach has been used to elucidate the role of ecological and historical processes in shaping tropical tree communities. Recent studies have shown that stressful environments, such as seasonally dry, white-sand and flooded forests tend to be phylogenetically clustered, arguing for niche conservatism as the main driver for this pattern. Very few studies have attempted to identify the lineages that contribute to such assembly patterns. We aimed to improve our understanding of the assembly of flooded forest tree communities in Northern South America by asking the following questions: are seasonally flooded forests phylogenetically clustered? If so, which angiosperm lineages are over-represented in seasonally flooded forests? To assess our hypotheses, we investigated seasonally flooded and terra firme forests from the Magdalena, Orinoco and Amazon Basins, in Colombia. Our results show that, regardless of the river basin in which they are located, seasonally flooded forests of Northern South America tend to be phylogenetically clustered, which means that the more abundant taxa in these forests are more closely related to each other than expected by chance. Based on our alpha and beta phylodiversity analyses we interpret that eudicots are more likely to adapt to extreme environments such as seasonally flooded forests, which indicates the importance of environmental filtering in the assembly of the Neotropical flora.

  1. South American Monsoon: Recent Droughts in the Context of Changing Global Circulation.

    Science.gov (United States)

    Seth, A.; Fernandes, K.; Camargo, S. J.

    2016-12-01

    The 2013-2015 drought in Southeast Brazil led to water shortages in São Paulo, the country's most populous city. The observed drought during austral summers of 2013/2014 and 2014/2015 and related large-scale dynamics are examined. The 2013-2014 precipitation deficits were more concentrated in the state of São Paulo, while in 2014-2015 moderate deficits were seen throughout the region. We find that a persistent warm sea surface temperature (SST) anomaly in the western tropical Pacific Ocean was an important driver of drought via atmospheric teleconnection in the two December-February seasons. The warm SST and associated convective heating initiated a wave train across the South Pacific. The resulting anticyclonic geopotential height anomaly over the southwest Atlantic expanded the westward margin of the South Atlantic high and prevented low-pressure systems from entering southeast Brazil from midlatitudes. This mechanism suggests a hemispheric symmetry to that proposed for the recent California drought. A first look at CMIP5 model projections to examine the role of large scale circulation changes to drought in the Sao Paulo region will be presented.

  2. Developing an intervention to address physical activity barriers for African-American women in the deep south (USA).

    Science.gov (United States)

    Pekmezi, Dori; Marcus, Bess; Meneses, Karen; Baskin, Monica L; Ard, Jamy D; Martin, Michelle Y; Adams, Natasia; Robinson, Cody; Demark-Wahnefried, Wendy

    2013-05-01

    To address high rates of inactivity and related chronic diseases among African-American women. Eleven focus groups on physical activity barriers for African-American women in the deep south (USA) were conducted (n = 56). Feedback guided an intervention development process. The resulting Home-Based Individually Tailored Physical Activity Print intervention was vetted with the target population in a 1-month, single arm, pre-post test demonstration trial (n = 10). Retention was high (90%). Intent-to-treat analyses indicated increases in motivational readiness for physical activity (70% of sample) and physical activity (7-day Physical Activity Recall) from baseline (mean: 89.5 min/week, standard deviation: 61.17) to 1 month (mean: 155 min/week, standard deviation: 100.86). Small improvements in fitness (6-Min Walk Test), weight and psychosocial process measures were also found. Preliminary findings show promise and call for future randomized controlled trials with larger samples to determine efficacy. Such low-cost, high-reach approaches to promoting physical activity have great potential for addressing health disparities and benefiting public health.

  3. Mycobacterium pinnipedii: Transmission from South American sea lion (Otaria byronia) to Bactrian camel (Camelus bactrianus bactrianus) and Malayan tapirs (Tapirus indicus)

    NARCIS (Netherlands)

    Moser, I.; Prodinger, W.M.; Hotzel, H.; Greenwald, R.; Lyashchenko, K.P.; Bakker, D.; Gomis, D.; Seidler, T.; Ellenberger, C.; Hetzel, U.; Wuennemann, K.; Moisson, P.

    2008-01-01

    Tuberculosis infections caused by Mycobacterium (M.) pinnipedii in a South American sea lion, Bactrian camel, and Malayan tapirs kept in two zoological gardens spanning a time period of 5 years are reported. The zoos were linked by the transfer of one tapir. Conventional bacteriological and

  4. Illicit Cigarette Trade in Five South American Countries: A Gap Analysis for Argentina, Brazil, Chile, Colombia and Peru.

    Science.gov (United States)

    Paraje, Guillermo

    2018-05-15

    Due to its nature, it is very hard to measure tobacco illicit trade in any product. In the case of Latin American countries, there is scant information on the magnitude and characteristics of this trade in the case of cigarettes. The goal of this article is to provide estimates on the evolution of the illicit cigarette trade in five South American countries: Argentina, Brazil, Chile, Colombia and Peru. Gap analysis estimates for cigarette tax evasion/avoidance (a comparison on the evolution of the difference between registered cigarette sales and measured population consumption) is developed for Argentina, Brazil, Chile, Colombia and Peru. Nationally representative surveys, conducted regularly, are used to measure population consumption. Confidence intervals constructed by bootstrapping sample estimates are generated in order to statistically evaluate the evolution of the gap. Cigarette illicit trade has increased as a percentage of total sales in Brazil in recent years. In the case of Argentina, after a relative decrease between 2005 and 2009 it seems to have stabilized. There is no statistical evidence to argue that there has been an increase of cigarette illicit trade in Chile, Colombia and Peru, despite substantial price increases in Chile and tax increase in both Colombia and Peru. Using simple statistical methods, it is possible to assess the trend in tobacco illicit trend over time to better inform policy-makers. Getting reliable and regular population consumption surveys can also help to track tobacco illicit trade. Claims by tobacco industry of a positive association between price/tax changes and illicit trade are unsubstantiated. Evolution of cigarette illicit trade in five Latin American countries show different trajectories, not in line with tobacco industry estimates, which highlight the importance of producing solid, independent estimates. There are inexpensive methodologies that can provide estimates of the evolution of the relative importance of

  5. Integrative screening approach identifies regulators of polyploidization and targets for acute megakaryocytic leukemia

    Science.gov (United States)

    Wen, Qiang; Goldenson, Benjamin; Silver, Serena J.; Schenone, Monica; Dancik, Vladimir; Huang, Zan; Wang, Ling-Zhi; Lewis, Timothy; An, W. Frank; Li, Xiaoyu; Bray, Mark-Anthony; Thiollier, Clarisse; Diebold, Lauren; Gilles, Laure; Vokes, Martha S.; Moore, Christopher B.; Bliss-Moreau, Meghan; VerPlank, Lynn; Tolliday, Nicola J.; Mishra, Rama; Vemula, Sasidhar; Shi, Jianjian; Wei, Lei; Kapur, Reuben; Lopez, Cécile K.; Gerby, Bastien; Ballerini, Paola; Pflumio, Francoise; Gilliland, D. Gary; Goldberg, Liat; Birger, Yehudit; Izraeli, Shai; Gamis, Alan S.; Smith, Franklin O.; Woods, William G.; Taub, Jeffrey; Scherer, Christina A.; Bradner, James; Goh, Boon-Cher; Mercher, Thomas; Carpenter, Anne E.; Gould, Robert J.; Clemons, Paul A.; Carr, Steven A.; Root, David E.; Schreiber, Stuart L.; Stern, Andrew M.; Crispino, John D.

    2012-01-01

    Summary The mechanism by which cells decide to skip mitosis to become polyploid is largely undefined. Here we used a high-content image-based screen to identify small-molecule probes that induce polyploidization of megakaryocytic leukemia cells and serve as perturbagens to help understand this process. We found that dimethylfasudil (diMF, H-1152P) selectively increased polyploidization, mature cell-surface marker expression, and apoptosis of malignant megakaryocytes. A broadly applicable, highly integrated target identification approach employing proteomic and shRNA screening revealed that a major target of diMF is Aurora A kinase (AURKA), which has not been studied extensively in megakaryocytes. Moreover, we discovered that MLN8237 (Alisertib), a selective inhibitor of AURKA, induced polyploidization and expression of mature megakaryocyte markers in AMKL blasts and displayed potent anti-AMKL activity in vivo. This research provides the rationale to support clinical trials of MLN8237 and other inducers of polyploidization in AMKL. Finally, we have identified five networks of kinases that regulate the switch to polyploidy. PMID:22863010

  6. Aurora B is dispensable for megakaryocyte polyploidization, but contributes to the endomitotic process.

    Science.gov (United States)

    Lordier, Larissa; Chang, Yunhua; Jalil, Abdelali; Aurade, Frédéric; Garçon, Loïc; Lécluse, Yann; Larbret, Frédéric; Kawashima, Toshiyuki; Kitamura, Toshio; Larghero, Jérôme; Debili, Najet; Vainchenker, William

    2010-09-30

    Polyploidization of megakaryocytes (MKs), the platelet precursors, occurs by endomitosis, a mitotic process that fails at late stages of cytokinesis. Expression and function of Aurora B kinase during endomitosis remain controversial. Here, we report that Aurora B is normally expressed during the human MK endomitotic process. Aurora B localized normally in the midzone or midbody during anaphase and telophase in low ploidy megakaryocytes and in up to 16N rare endomitotic MKs was observed. Aurora B was also functional during cytokinesis as attested by phosphorylation of both its activation site and MgcRacGAP, its main substrate. However, despite its activation, Aurora B did not prevent furrow regression. Inhibition of Aurora B by AZD1152-HQPA decreased cell cycle entry both in 2N to 4N and polyploid MKs and induced apoptosis mainly in 2N to 4N cells. In both MK classes, AZD1152-HQPA induced p53 activation and retinoblastoma hypophosphorylation. Resistance of polyploid MKs to apoptosis correlated to a high BclxL level. Aurora B inhibition did not impair MK polyploidization but profoundly modified the endomitotic process by inducing a mis-segregation of chromosomes and a mitotic failure in anaphase. This indicates that Aurora B is dispensable for MK polyploidization but is necessary to achieve a normal endomitotic process.

  7. Identification of regulators of polyploidization presents therapeutic targets for treatment of AMKL.

    Science.gov (United States)

    Wen, Qiang; Goldenson, Benjamin; Silver, Serena J; Schenone, Monica; Dancik, Vlado; Huang, Zan; Wang, Ling-Zhi; Lewis, Timothy A; An, W Frank; Li, Xiaoyu; Bray, Mark-Anthony; Thiollier, Clarisse; Diebold, Lauren; Gilles, Laure; Vokes, Martha S; Moore, Christopher B; Bliss-Moreau, Meghan; Verplank, Lynn; Tolliday, Nicola J; Mishra, Rama; Vemula, Sasidhar; Shi, Jianjian; Wei, Lei; Kapur, Reuben; Lopez, Cécile K; Gerby, Bastien; Ballerini, Paola; Pflumio, Francoise; Gilliland, D Gary; Goldberg, Liat; Birger, Yehudit; Izraeli, Shai; Gamis, Alan S; Smith, Franklin O; Woods, William G; Taub, Jeffrey; Scherer, Christina A; Bradner, James E; Goh, Boon-Cher; Mercher, Thomas; Carpenter, Anne E; Gould, Robert J; Clemons, Paul A; Carr, Steven A; Root, David E; Schreiber, Stuart L; Stern, Andrew M; Crispino, John D

    2012-08-03

    The mechanism by which cells decide to skip mitosis to become polyploid is largely undefined. Here we used a high-content image-based screen to identify small-molecule probes that induce polyploidization of megakaryocytic leukemia cells and serve as perturbagens to help understand this process. Our study implicates five networks of kinases that regulate the switch to polyploidy. Moreover, we find that dimethylfasudil (diMF, H-1152P) selectively increased polyploidization, mature cell-surface marker expression, and apoptosis of malignant megakaryocytes. An integrated target identification approach employing proteomic and shRNA screening revealed that a major target of diMF is Aurora kinase A (AURKA). We further find that MLN8237 (Alisertib), a selective inhibitor of AURKA, induced polyploidization and expression of mature megakaryocyte markers in acute megakaryocytic leukemia (AMKL) blasts and displayed potent anti-AMKL activity in vivo. Our findings provide a rationale to support clinical trials of MLN8237 and other inducers of polyploidization and differentiation in AMKL. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Intergenomic rearrangements after polyploidization of Kengyilia thoroldiana (Poaceae: Triticeae) affected by environmental factors.

    Science.gov (United States)

    Wang, Qiuxia; Liu, Huitao; Gao, Ainong; Yang, Xinming; Liu, Weihua; Li, Xiuquan; Li, Lihui

    2012-01-01

    Polyploidization is a major evolutionary process. Approximately 70-75% species of Triticeae (Poaceae) are polyploids, involving 23 genomes. To investigate intergenomic rearrangements after polyploidization of Triticeae species and to determine the effects of environmental factors on them, nine populations of a typical polyploid Triticeae species, Kengyilia thoroldiana (Keng) J.L.Yang et al. (2n = 6x = 42, StStPPYY), collected from different environments, were studied using genome in situ hybridization (GISH). We found that intergenomic rearrangements occurred between the relatively large P genome and the small genomes, St (8.15%) and Y (22.22%), in polyploid species via various types of translocations compared to their diploid progenitors. However, no translocation was found between the relatively small St and Y chromosomes. Environmental factors may affect rearrangements among the three genomes. Chromosome translocations were significantly more frequent in populations from cold alpine and grassland environments than in populations from valley and lake-basin habitats (P<0.05). The relationship between types of chromosome translocations and altitude was significant (r = 0.809, P<0.01). Intergenomic rearrangements associated with environmental factors and genetic differentiation of a single basic genome should be considered as equally important genetic processes during species' ecotype evolution.

  9. Polyploidization and cell fusion contribute to wound healing in the adult Drosophila epithelium.

    Science.gov (United States)

    Losick, Vicki P; Fox, Donald T; Spradling, Allan C

    2013-11-18

    Reestablishing epithelial integrity and biosynthetic capacity is critically important following tissue damage. The adult Drosophila abdominal epithelium provides an attractive new system to address how postmitotic diploid cells contribute to repair. Puncture wounds to the adult Drosophila epidermis close initially by forming a melanized scab. We found that epithelial cells near the wound site fuse to form a giant syncytium, which sends lamellae under the scab to re-epithelialize the damaged site. Other large cells arise more peripherally by initiating endocycles and becoming polyploid, or by cell fusion. Rac GTPase activity is needed for syncytium formation, while the Hippo signaling effector Yorkie modulates both polyploidization and cell fusion. Large cell formation is functionally important because when both polyploidization and fusion are blocked, wounds do not re-epithelialize. Our observations indicate that cell mass lost upon wounding can be replaced by polyploidization instead of mitotic proliferation. We propose that large cells generated by polyploidization or cell fusion are essential because they are better able than diploid cells to mechanically stabilize wounds, especially those containing permanent acellular structures, such as scar tissue. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Polyploidization in Heuchera cylindrica (Saxifragaceae) did not result in a shift in climatic requirements.

    Science.gov (United States)

    Godsoe, William; Larson, Megan A; Glennon, Kelsey L; Segraves, Kari A

    2013-03-01

    Polyploidization is a key factor involved in the diversification of plants. Although polyploids are commonly found, there remains controversy on the mechanisms that lead to their successful establishment. One major problem that has been identified is that newly formed polyploids lack mates of the appropriate ploidy level and may experience severely reduced fertility due to nonproductive intercytotype crosses. Niche differentiation has been proposed as a primary mechanism that can alleviate this reproductive disadvantage and facilitate polyploid establishment. Here we test whether the establishment of tetraploid cytotypes of Heuchera cylindrica (Saxifragaceae) is consistent with climatic niche differentiation. • We use a combination of field surveys, flow cytometry and species distribution models to: (1) examine the distribution of diploid and tetraploid cytotypes; and (2) determine whether tetraploid Heuchera cylindrica occupy climates that differ from those of its diploid progenitors. • The geographic distributions of diploid and tetraploid cytotypes are largely allopatric as an extensive survey of 636 plants from 43 locations failed to detect any populations with both cytotypes. Although diploids and tetraploids occur in different geographic areas, polyploid Heuchera cylindrica occur almost exclusively in environments that are predicted to be suitable to diploid populations. • Climatic niche differentiation does not explain the geographic distribution of tetraploid Heuchera cylindrica. We propose instead that tetraploid lineages were able to establish by taking advantage of glacial retreat and expanding into previously unoccupied sites.

  11. Intergenomic rearrangements after polyploidization of Kengyilia thoroldiana (Poaceae: Triticeae affected by environmental factors.

    Directory of Open Access Journals (Sweden)

    Qiuxia Wang

    Full Text Available Polyploidization is a major evolutionary process. Approximately 70-75% species of Triticeae (Poaceae are polyploids, involving 23 genomes. To investigate intergenomic rearrangements after polyploidization of Triticeae species and to determine the effects of environmental factors on them, nine populations of a typical polyploid Triticeae species, Kengyilia thoroldiana (Keng J.L.Yang et al. (2n = 6x = 42, StStPPYY, collected from different environments, were studied using genome in situ hybridization (GISH. We found that intergenomic rearrangements occurred between the relatively large P genome and the small genomes, St (8.15% and Y (22.22%, in polyploid species via various types of translocations compared to their diploid progenitors. However, no translocation was found between the relatively small St and Y chromosomes. Environmental factors may affect rearrangements among the three genomes. Chromosome translocations were significantly more frequent in populations from cold alpine and grassland environments than in populations from valley and lake-basin habitats (P<0.05. The relationship between types of chromosome translocations and altitude was significant (r = 0.809, P<0.01. Intergenomic rearrangements associated with environmental factors and genetic differentiation of a single basic genome should be considered as equally important genetic processes during species' ecotype evolution.

  12. Parvovirus-derived endogenous viral elements in two South American rodent genomes.

    Science.gov (United States)

    Arriagada, Gloria; Gifford, Robert J

    2014-10-01

    We describe endogenous viral elements (EVEs) derived from parvoviruses (family Parvoviridae) in the genomes of the long-tailed chinchilla (Chinchilla lanigera) and the degu (Octodon degus). The novel EVEs include dependovirus-related elements and representatives of a clearly distinct parvovirus lineage that also has endogenous representatives in marsupial genomes. In the degu, one dependovirus-derived EVE was found to carry an intact reading frame and was differentially expressed in vivo, with increased expression in the liver. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  13. A Comparative Analysis of Prenatal Care and Fetal Growth in Eight South American Countries

    Science.gov (United States)

    Woodhouse, Cristina; Lopez Camelo, Jorge; Wehby, George L.

    2014-01-01

    There has been little work that comprehensively compared the relationship between prenatal care and infant health across multiple countries using similar data sources and analytical models. Such comparative analyses are useful for understanding the background of differences in infant health between populations. We evaluated the association between prenatal care visits and fetal growth measured by birth weight (BW) in grams or low birth weight (Prenatal care visits were significantly (at pprenatal care and fetal growth are population-specific and may not be generalizable to other populations. Furthermore, as one of the indicators for a country’s healthcare system for maternal and child health, prenatal care is a highly variable indicator between countries in South America. PMID:24625630

  14. Geographic patterns of genetic variation and conservation consequences in three South American rodents.

    Science.gov (United States)

    Miranda, Gustavo B; Andrades-Miranda, Jaqueline; Oliveira, Luiz F B; Langguth, Alfredo; Mattevi, Margarete S

    2007-12-01

    In this study, the geographic patterns of genetic variation of three rodent species belonging to the tribe Oryzomyini were investigated using the mitochondrial cytochrome b and nuclear IRBP genes in biomes that are undergoing degradation processes to a greater or lesser degree. The samples are from 25 collecting localities distributed throughout the Amazon, Cerrado, Atlantic Forest, and Pampa biomes. The results show that the three species have a population and geographic structure, besides being in demographic equilibrium. The phylogenetic analyses performed on Euryoryzomys russatus and Hylaeamys megacephalus showed these specimens grouped in three distinct clades forming geographic gradients (North-South direction in H. megacephalus). Intraspecific genetic divergence was higher in H. megacephalus (4.53%), followed by E. russatus (1.79%), and lowest in Sooretamys angouya (0.88%). The results obtained indicate that, necessarily, the management strategies to preserve genetic diversity should be different for each species, since each of them presented specific population parameters.

  15. Optimizing Surveillance for South American Origin Influenza A Viruses Along the United States Gulf Coast Through Genomic Characterization of Isolates from Blue-winged Teal (Anas discors).

    Science.gov (United States)

    Ramey, A M; Walther, P; Link, P; Poulson, R L; Wilcox, B R; Newsome, G; Spackman, E; Brown, J D; Stallknecht, D E

    2016-04-01

    Relative to research focused on inter-continental viral exchange between Eurasia and North America, less attention has been directed towards understanding the redistribution of influenza A viruses (IAVs) by wild birds between North America and South America. In this study, we genomically characterized 45 viruses isolated from blue-winged teal (Anas discors) along the Texas and Louisiana Gulf Coast during March of 2012 and 2013, coincident with northward migration of this species from Neotropical wintering areas to breeding grounds in the United States and Canada. No evidence of South American lineage genes was detected in IAVs isolated from blue-winged teal supporting restricted viral gene flow between the United States and southern South America. However, it is plausible that blue-winged teal redistribute IAVs between North American breeding grounds and wintering areas throughout the Neotropics, including northern South America, and that viral gene flow is limited by geographical barriers further south (e.g., the Amazon Basin). Surveillance for the introduction of IAVs from Central America and northern South America into the United States may be further optimized through genomic characterization of viruses resulting from coordinated, concurrent sampling efforts targeting blue-winged teal and sympatric species throughout the Neotropics and along the United States Gulf Coast. © Published 2014. This article is a US Government work and is in the public domain in the USA.

  16. Exploring karyotype diversity of Argentinian Guaraní maize landraces: Relationship among South American maize.

    Directory of Open Access Journals (Sweden)

    María Florencia Realini

    Full Text Available In Argentina there are two different centers of maize diversity, the Northeastern (NEA and the Northwestern (NWA regions of the country. In NEA, morphological studies identified 15 landraces cultivated by the Guaraní communities in Misiones Province. In the present study we analyzed the karyotype diversity of 20 populations of Guaraní maize landraces through classical and molecular cytogenetic analyses. Our results demonstrate significant intra and inter-populational variation in the percentage, number, size, chromosome position and frequencies of the heterochromatic blocks, which are called knobs. Knob sequence analysis (180-bp and TR-1 did not show significant differences among Guaraní populations. B chromosomes were not detected, and abnormal 10 (AB10 chromosomes were found with low frequency (0.1≥f ≤0.40 in six populations. Our results allowed karyotypic characterization of each analyzed population, defining for the first time the chromosomal constitution of maize germplasm from NEA. The multivariate analysis (PCoA and UPGMA of karyotype parameters allowed the distinction between two populations groups: the Popcorn and the Floury maize populations. These results are in agreement with previously published microsatellite and morphological/phenological studies. Finally, we compared our karyotype results with those previously reported for NWA and Central Region of South America maize. Our data suggest that there are important differences between maize from NEA and NWA at the karyotype level, supporting the hypothesis that there are two pathways of input of South America maize. Our results also confirm the existence of two centers of diversification of Argentinian native maize, NWA and NEA. This work contributes new knowledge about maize diversity, which is relevant for future plans to improve commercial maize, and for conservation of agrobiodiversity.

  17. Development and Applications of a High Throughput Genotyping Tool for Polyploid Crops: Single Nucleotide Polymorphism (SNP Array

    Directory of Open Access Journals (Sweden)

    Qian You

    2018-02-01

    Full Text Available Polypoid species play significant roles in agriculture and food production. Many crop species are polyploid, such as potato, wheat, strawberry, and sugarcane. Genotyping has been a daunting task for genetic studies of polyploid crops, which lags far behind the diploid crop species. Single nucleotide polymorphism (SNP array is considered to be one of, high-throughput, relatively cost-efficient and automated genotyping approaches. However, there are significant challenges for SNP identification in complex, polyploid genomes, which has seriously slowed SNP discovery and array development in polyploid species. Ploidy is a significant factor impacting SNP qualities and validation rates of SNP markers in SNP arrays, which has been proven to be a very important tool for genetic studies and molecular breeding. In this review, we (1 discussed the pros and cons of SNP array in general for high throughput genotyping, (2 presented the challenges of and solutions to SNP calling in polyploid species, (3 summarized the SNP selection criteria and considerations of SNP array design for polyploid species, (4 illustrated SNP array applications in several different polyploid crop species, then (5 discussed challenges, available software, and their accuracy comparisons for genotype calling based on SNP array data in polyploids, and finally (6 provided a series of SNP array design and genotype calling recommendations. This review presents a complete overview of SNP array development and applications in polypoid crops, which will benefit the research in molecular breeding and genetics of crops with complex genomes.

  18. Genetic Diversity and Population Structure of Varronia curassavica: A Medicinal Polyploid Species in a Threatened Ecosystem.

    Science.gov (United States)

    Hoeltgebaum, Marcia Patricia; Dos Reis, Maurício Sedrez

    2017-06-01

    Varronia curassavica is an important medicinal species associated with the restinga, one of the most threatened coastal ecosystems of the Atlantic Forest. These circumstances call for studies aimed at estimating effective population size and gene flow to improve conservation efforts. Hence, the present study aimed to characterize the genetic diversity, ploidy level, and population structure of this species in different areas of restinga using microsatellites. Varronia curassavica was characterized as an autotetraploid, with high genetic variability, low divergence, and no significant fixation indices, indicating the absence of, or reduced, inbreeding and genetic drift in the study area. About 44% of the alleles occurred at low frequency in adults of all populations and 41% in the progenies evaluated. Gene flow was high, consistent with outcrossing species with high dispersal capacity (Nm = 4.87). The results showed no tendency toward isolation by distance. The estimated effective size indicates that the populations studied have the potential to ensure conservation of the species in the long term. The genetic variability and population structure of V. curassavica, as determined in this study, could form the foundation for activities directed toward the sustainable use of this resource and its conservation. Even though the restinga ecosystem has suffered dramatic reductions in area, this study provides evidence that this species is resilient to anthropogenic threats to its genetic integrity, since it is a polyploid with self-incompatibility mechanisms that contribute to maintaining high genetic diversity in an panmictic meta-population along the coast of Santa Catarina. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. The Brassica oleracea genome reveals the asymmetrical evolution of polyploid genomes

    Science.gov (United States)

    Liu, Shengyi; Liu, Yumei; Yang, Xinhua; Tong, Chaobo; Edwards, David; Parkin, Isobel A. P.; Zhao, Meixia; Ma, Jianxin; Yu, Jingyin; Huang, Shunmou; Wang, Xiyin; Wang, Junyi; Lu, Kun; Fang, Zhiyuan; Bancroft, Ian; Yang, Tae-Jin; Hu, Qiong; Wang, Xinfa; Yue, Zhen; Li, Haojie; Yang, Linfeng; Wu, Jian; Zhou, Qing; Wang, Wanxin; King, Graham J; Pires, J. Chris; Lu, Changxin; Wu, Zhangyan; Sampath, Perumal; Wang, Zhuo; Guo, Hui; Pan, Shengkai; Yang, Limei; Min, Jiumeng; Zhang, Dong; Jin, Dianchuan; Li, Wanshun; Belcram, Harry; Tu, Jinxing; Guan, Mei; Qi, Cunkou; Du, Dezhi; Li, Jiana; Jiang, Liangcai; Batley, Jacqueline; Sharpe, Andrew G; Park, Beom-Seok; Ruperao, Pradeep; Cheng, Feng; Waminal, Nomar Espinosa; Huang, Yin; Dong, Caihua; Wang, Li; Li, Jingping; Hu, Zhiyong; Zhuang, Mu; Huang, Yi; Huang, Junyan; Shi, Jiaqin; Mei, Desheng; Liu, Jing; Lee, Tae-Ho; Wang, Jinpeng; Jin, Huizhe; Li, Zaiyun; Li, Xun; Zhang, Jiefu; Xiao, Lu; Zhou, Yongming; Liu, Zhongsong; Liu, Xuequn; Qin, Rui; Tang, Xu; Liu, Wenbin; Wang, Yupeng; Zhang, Yangyong; Lee, Jonghoon; Kim, Hyun Hee; Denoeud, France; Xu, Xun; Liang, Xinming; Hua, Wei; Wang, Xiaowu; Wang, Jun; Chalhoub, Boulos; Paterson, Andrew H

    2014-01-01

    Polyploidization has provided much genetic variation for plant adaptive evolution, but the mechanisms by which the molecular evolution of polyploid genomes establishes genetic architecture underlying species differentiation are unclear. Brassica is an ideal model to increase knowledge of polyploid evolution. Here we describe a draft genome sequence of Brassica oleracea, comparing it with that of its sister species B. rapa to reveal numerous chromosome rearrangements and asymmetrical gene loss in duplicated genomic blocks, asymmetrical amplification of transposable elements, differential gene co-retention for specific pathways and variation in gene expression, including alternative splicing, among a large number of paralogous and orthologous genes. Genes related to the production of anticancer phytochemicals and morphological variations illustrate consequences of genome duplication and gene divergence, imparting biochemical and morphological variation to B. oleracea. This study provides insights into Brassica genome evolution and will underpin research into the many important crops in this genus. PMID:24852848

  20. Bcl-XL represents a druggable molecular vulnerability during aurora B inhibitor-mediated polyploidization.

    Science.gov (United States)

    Shah, O Jameel; Lin, Xiaoyu; Li, Leiming; Huang, Xiaoli; Li, Junling; Anderson, Mark G; Tang, Hua; Rodriguez, Luis E; Warder, Scott E; McLoughlin, Shaun; Chen, Jun; Palma, Joann; Glaser, Keith B; Donawho, Cherrie K; Fesik, Stephen W; Shen, Yu

    2010-07-13

    Aurora kinase B inhibitors induce apoptosis secondary to polyploidization and have entered clinical trials as an emerging class of neocytotoxic chemotherapeutics. We demonstrate here that polyploidization neutralizes Mcl-1 function, rendering cancer cells exquisitely dependent on Bcl-XL/-2. This "addiction" can be exploited therapeutically by combining aurora kinase inhibitors and the orally bioavailable BH3 mimetic, ABT-263, which inhibits Bcl-XL, Bcl-2, and Bcl-w. The combination of ABT-263 with aurora B inhibitors produces a synergistic loss of viability in a range of cell lines of divergent tumor origin and exhibits more sustained tumor growth inhibition in vivo compared with aurora B inhibitor monotherapy. These data demonstrate that Bcl-XL/-2 is necessary to support viability during polyploidization in a variety of tumor models and represents a druggable molecular vulnerability with potential therapeutic utility.

  1. Wound-Induced Polyploidization: Regulation by Hippo and JNK Signaling and Conservation in Mammals.

    Science.gov (United States)

    Losick, Vicki P; Jun, Albert S; Spradling, Allan C

    2016-01-01

    Tissue integrity and homeostasis often rely on the proliferation of stem cells or differentiated cells to replace lost, aged, or damaged cells. Recently, we described an alternative source of cell replacement- the expansion of resident, non-dividing diploid cells by wound-induced polyploidization (WIP). Here we show that the magnitude of WIP is proportional to the extent of cell loss using a new semi-automated assay with single cell resolution. Hippo and JNK signaling regulate WIP; unexpectedly however, JNK signaling through AP-1 limits rather than stimulates the level of Yki activation and polyploidization in the Drosophila epidermis. We found that polyploidization also quantitatively compensates for cell loss in a mammalian tissue, mouse corneal endothelium, where increased cell death occurs with age in a mouse model of Fuchs Endothelial Corneal Dystrophy (FECD). Our results suggest that WIP is an evolutionarily conserved homeostatic mechanism that maintains the size and synthetic capacity of adult tissues.

  2. Rho kinase inhibition drives megakaryocyte polyploidization and proplatelet formation through MYC and NFE2 downregulation.

    Science.gov (United States)

    Avanzi, Mauro P; Goldberg, Francine; Davila, Jennifer; Langhi, Dante; Chiattone, Carlos; Mitchell, William Beau

    2014-03-01

    The processes of megakaryocyte polyploidization and demarcation membrane system (DMS) formation are crucial for platelet production, but the mechanisms controlling these processes are not fully determined. Inhibition of Rho kinase (ROCK) signalling leads to increased polyploidization in umbilical cord blood-derived megakaryocytes. To extend these findings we determined the effect of ROCK inhibition on development of the DMS and on proplatelet formation. The underlying mechanisms were explored by analysing the effect of ROCK inhibition on the expression of MYC and NFE2, which encode two transcription factors critical for megakaryocyte development. ROCK inhibition promoted DMS formation, and increased proplatelet formation and platelet release. Rho kinase inhibition also downregulated MYC and NFE2 expression in mature megakaryocytes, and this down-regulation correlated with increased proplatelet formation. Our findings suggest a model whereby ROCK inhibition drives polyploidization, DMS growth and proplatelet formation late in megakaryocyte maturation through downregulation of MYC and NFE2 expression. © 2014 John Wiley & Sons Ltd.

  3. Seed crop size variation in the dominant South American conifer Araucaria angustifolia

    Science.gov (United States)

    Souza, Alexandre F.; Uarte de Matos, Daniele; Forgiarini, Cristiane; Martinez, Jaime

    2010-01-01

    Temporal variation in seed crop size of the long-lived pioneer conifer Araucaria angustifolia was studied in subtropical South America. We evaluated the expectations that: 1) A. angustifolia presents highly variable seed production (mast seeding behavior); 2) A. angustifolia has endogenous cycles of reproduction of two or three years; 3) There is a tendency for a high seed production year to be followed by an unusually low production year; 4) populations show synchrony in seed production at a geographical scale; 5) seed crop size is influenced by distinct climatic factors occurring during "key" reproductive stages and 6) as an expression of plant productivity, seed crop size should depend on integrated resource availability during the reproductive cycle. We obtained data from two distinct sources: 1) seed harvesting records from a private forest (14 years), and 2) commercial data from 22 municipalities in the Rio Grande do Sul State. Expectations 1, 2, 3 and 5 were not met, while expectations 4 and 6 were supported by the data. A. angustifolia showed environmentally triggered, continuous, moderately fluctuating, and regionally synchronous reproduction. Seed set seems to track variations in resource abundance as well as respond continuously to improved opportunities for successful regeneration.

  4. Total mercury, organic mercury and selenium in liver and kidney of a South American coastal dolphin

    International Nuclear Information System (INIS)

    Seixas, Tercia G.; Kehrig, Helena do A.; Costa, Monica; Fillmann, Gilberto; Di Beneditto, Ana Paula M.; Secchi, Eduardo R.; Souza, Cristina M.M.; Malm, Olaf; Moreira, Isabel

    2008-01-01

    Selenium and total and organic mercury were determined in the liver and kidney of franciscana dolphin (Pontoporia blainvillei) incidentally caught in fishing nets along two Brazilian coastal areas (southeast and south). Regional differences in the concentrations of these contaminants were observed in P. blainvillei. Liver showed the highest organic and total mercury. In general, samples of individuals collected at the southern of Brazil had the highest concentrations of selenium and total and organic mercury. No significant gender differences were observed. Growth stage influenced the accumulation of these contaminants in both organs, and hepatic concentrations increased with the body length, according to the sampling area. Molar mercury and selenium concentrations in liver were significantly correlated, with a Se:Hg ratio close to 4. The among-site differences we found may be related to differences in preferred prey, bioavailability in the marine environment, environmental conditions, or these individuals may belong to distinct populations. - This study presents some useful data on the bioaccumulation of Hg, organic Hg and Se, and their inter-element relationships in a Brazilian small cetacean

  5. Total mercury, organic mercury and selenium in liver and kidney of a South American coastal dolphin

    Energy Technology Data Exchange (ETDEWEB)

    Seixas, Tercia G. [Departamento de Quimica, PUC-Rio, 22453-900 Rio de Janeiro, RJ (Brazil); Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil)], E-mail: tercia@rdc.puc-rio.br; Kehrig, Helena do A. [Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil); Costa, Monica [Departamento de Oceanografia, CTG-UFPE, 50740-550 Recife, PE (Brazil); Fillmann, Gilberto [Departamento de Oceanografia, FURG, C.P. 474, 96201-900 Rio Grande, RS (Brazil); Di Beneditto, Ana Paula M. [Laboratorio de Ciencias Ambientais, CBB-UENF, 28013-602 Campos dos Goytacazes, RJ (Brazil); Secchi, Eduardo R. [Departamento de Oceanografia, FURG, C.P. 474, 96201-900 Rio Grande, RS (Brazil); Laboratorio de Tartarugas e Mamiferos Marinhos, Departamento de Oceanografia e Museu Oceanografico ' Prof. E.C. Rios' , FURG, 96201-900 Rio Grande, RS (Brazil); Souza, Cristina M.M. [Laboratorio de Ciencias Ambientais, CBB-UENF, 28013-602 Campos dos Goytacazes, RJ (Brazil); Malm, Olaf [Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil); Moreira, Isabel [Departamento de Quimica, PUC-Rio, 22453-900 Rio de Janeiro, RJ (Brazil)

    2008-07-15

    Selenium and total and organic mercury were determined in the liver and kidney of franciscana dolphin (Pontoporia blainvillei) incidentally caught in fishing nets along two Brazilian coastal areas (southeast and south). Regional differences in the concentrations of these contaminants were observed in P. blainvillei. Liver showed the highest organic and total mercury. In general, samples of individuals collected at the southern of Brazil had the highest concentrations of selenium and total and organic mercury. No significant gender differences were observed. Growth stage influenced the accumulation of these contaminants in both organs, and hepatic concentrations increased with the body length, according to the sampling area. Molar mercury and selenium concentrations in liver were significantly correlated, with a Se:Hg ratio close to 4. The among-site differences we found may be related to differences in preferred prey, bioavailability in the marine environment, environmental conditions, or these individuals may belong to distinct populations. - This study presents some useful data on the bioaccumulation of Hg, organic Hg and Se, and their inter-element relationships in a Brazilian small cetacean.

  6. The history of South American tropical precipitation for the past 25,000 years.

    Science.gov (United States)

    Baker, P A; Seltzer, G O; Fritz, S C; Dunbar, R B; Grove, M J; Tapia, P M; Cross, S L; Rowe, H D; Broda, J P

    2001-01-26

    Long sediment cores recovered from the deep portions of Lake Titicaca are used to reconstruct the precipitation history of tropical South America for the past 25,000 years. Lake Titicaca was a deep, fresh, and continuously overflowing lake during the last glacial stage, from before 25,000 to 15,000 calibrated years before the present (cal yr B.P.), signifying that during the last glacial maximum (LGM), the Altiplano of Bolivia and Peru and much of the Amazon basin were wetter than today. The LGM in this part of the Andes is dated at 21,000 cal yr B.P., approximately coincident with the global LGM. Maximum aridity and lowest lake level occurred in the early and middle Holocene (8000 to 5500 cal yr B.P.) during a time of low summer insolation. Today, rising levels of Lake Titicaca and wet conditions in Amazonia are correlated with anomalously cold sea-surface temperatures in the northern equatorial Atlantic. Likewise, during the deglacial and Holocene periods, there were several millennial-scale wet phases on the Altiplano and in Amazonia that coincided with anomalously cold periods in the equatorial and high-latitude North Atlantic, such as the Younger Dryas.

  7. Differences and Similarities among Parotoid Macrogland Secretions in South American Toads: A Preliminary Biochemical Delineation

    Directory of Open Access Journals (Sweden)

    Juliana Mozer Sciani

    2013-01-01

    Full Text Available Amphibians are known by cutaneous glands, spread over the skin, containing toxins (proteins, peptides, biogenic amines, steroidal bufadienolides, and alkaloids used as chemical defense against predators and microbial infection. Toads are characterized by the presence of parotoid macroglands. The common toads have lately been divided into two genera: Bufo (Europe, Asia, and Africa and Rhinella (South America. Basal Rhaebo genus is exclusively of Central America and Amazon region. Although Rhinella and Rhaebo are related, species may share differences due to the diversity of environments that they live in. In this work, we have performed a biochemical characterization of the components of the poison of eight Rhinella species and one Rhaebo by means of RP-HPLC with either UV or MS detection and by SDS-PAGE, in order to verify whether phylogenetic and biological differences, such as habitat, diet, and defensive strategies, between them may also be reflected in poison composition. Although some components were common among the secretions, we were able to identify exclusive molecules to some species. The fact that closely related animals living in different habitats secrete different molecules into the skin is an indication that biological features, and not only evolution, seem to directly influence the skin secretion composition.

  8. Revision of the South American wasp genus Alophophion Cushman, 1947 (Hymenoptera: Ichneumonidae: Ophioninae

    Directory of Open Access Journals (Sweden)

    Mabel Alvarado

    2014-05-01

    Full Text Available The species of the strictly Neotropical ophionine wasp genus Alophophion Cushman, 1947 are revised. New descriptions of all previously named species are provided, except Alophophion holosericeus (Taschenberg, 1875 for which the type series is lost and the name is herein considered a nomen dubium. The female of A. flavorufus (Brullé, 1846 is described for the first time. Four informal species groups are proposed based on the morphology of the mandibles, development of the malar space, and general proportions of the head (i.e., development of the face and gena. Whereas the genus previously included only seven named species, it is here expanded to include 49 species (not including the aforementioned nomen dubium, 43 of which are newly discovered and described and thereby increasing the diversity by over eight times. A key to the four species groups and their included taxa is provided. Alophophion is confined to cold and/or dry areas of subequatorial South America, with the exception of A. mancocapaci new species and A. pedroi new species which occur incloud forests around Cuzco, Peru. The genus is newly recorded from Bolivia and Ecuador, and more extensive and accurate distributions are summarized for A. chilensis, A. flavorufus, and A. politus. Alophophion flavorufus is newly recorded from Argentina.Traduce

  9. Leading El-Niño SST Oscillations around the Southern South American Continent

    Directory of Open Access Journals (Sweden)

    Yu-Chen Hsu

    2018-05-01

    Full Text Available The inter-annual variations in the sea surface temperatures (SSTs of the tropical and subtropical Pacific Ocean have been widely investigated, largely due to their importance in achieving the sustainable development of marine ecosystems under a changing climate. The El Niño-Southern Oscillation (ENSO is a widely recognized variability. In the subpolar region in the southern hemisphere, the Antarctic Circumpolar Current (ACC is one of the main sources of the Peru Current. A change in the SST in the Southern Ocean may change the physical properties of the seawater in the tropical and subtropical Pacific Ocean. However, the variations in the SST in the Southern Ocean have rarely been addressed. This study uses a 147-year (1870–2016 dataset from the Met Office Hadley Centre to show that the SST anomalies (SSTAs in the oceans west and east of South America and the Antarctic Peninsula have strong positive (R = 0.56 and negative (R = −0.67 correlations with the Niño 3.4 SSTA, respectively. Such correlations are likely related to the changes in circulations of the ACC. We further show that, statistically, the temporal variations in the SSTAs of the ACC lead the Niño 3.4 SSTA by four to six months. Such findings imply that change in the strength of ENSO or circulation under the changing climate could change the climate in regions at higher latitudes as well.

  10. Cyberbullying in South African and American schools: A legal comparative study

    Directory of Open Access Journals (Sweden)

    DM Smit

    2015-05-01

    Full Text Available Bullying conjures up visions of the traditional schoolyard bully and the subordinate victim. However, bullying is no longer limited to in-person encounter, having come to include cyberbullying, which takes place indirectly over electronic media. In this electronic age, cyber platforms proliferate at an astonishing rate, all attracting the youth in large number, and posing the risk that they may become subject to cyberbullying. Far from being limited to those individual learners being cyberbullied, the effects of this phenomenon extend to the learner collective, the school climate, and also the entire school system, management and education, thus requiring an urgent response. This article first provides a general overview of cyberbullying and its impact on learners, schools and education. This is done through a comparative lens, studying the extent of the phenomenon in both the United States and South Africa. The focus then shifts to the existing legislative frameworks within which the phenomenon is tackled in these respective jurisdictions, particularly the tricky balancing act required between learners' constitutional right to free speech and expression, and the protection of vulnerable learners' right to equality, dignity and privacy. The article concludes by proposing certain possible solutions to the problem.

  11. Intestinal helminth fauna of the South American sea lion Otaria flavescens and fur seal Arctocephalus australis from northern Patagonia, Argentina.

    Science.gov (United States)

    Hernández-Orts, J S; Montero, F E; Juan-García, A; García, N A; Crespo, E A; Raga, J A; Aznar, F J

    2013-09-01

    We report on the intestinal helminth fauna of 56 South American sea lions, Otaria flavescens, and 5 South American fur seals, Arctocephalus australis, from northern Patagonia, Argentina. A total of 97,325 helminth specimens were collected from sea lions. Gravid individuals were represented by 6 species of parasites: 1 digenean (Ascocotyle (Ascocotyle) patagoniensis), 1 cestode (Diphyllobothrium spp.), 3 nematodes (Uncinaria hamiltoni, Contracaecum ogmorhini s.s., Pseudoterranova cattani) and 1 acanthocephalan (Corynosoma australe). In addition, third-stage larvae of 2 nematodes (Contracaecum sp. and Anisakis sp. type I) and 3 juvenile acanthocephalans (Andracantha sp., Profilicollis chasmagnathi and Corynosoma cetaceum) were also collected. Andracantha sp., C. ogmorhini s.s. and P. chasmagnathi represent new host records. A total of 1516 helminth specimens were collected from fur seals. Gravid individuals were represented by three species of parasites, namely, Diphyllobothrium spp., C. ogmorhini s.s. and C. australe. In addition, larvae of Contracaecum sp. and P. cattani, juveniles of C. cetaceum and immature cestodes (Tetrabothriidae gen. sp.) were also collected. Corynosoma australe was the most prevalent and abundant parasite in both hosts, accounting for >90% of all specimens. Sea lions and furs seals from northern Patagonia harbour the intestinal helminth communities that could be predicted for otariids, i.e. the combination of species of the genera Corynosoma, Diphyllobothrium, Pseudoterranova, Contracaecum and, in pups, Uncinaria. Additionally, both species of otariid are apparently unsuitable hosts (i.e. non-hosts) for as many as five parasite taxa. The inclusion or exclusion of these species affects estimation of species richness at both component community (11 versus 6 species in sea lions; 7 versus 3 species in fur seals) and infracommunity (mean: 3.1 versus 2.6 in sea lions; 2.2 versus 1.7 species) levels. Information about the reproductive status of

  12. Discovery of South American suckermouth armored catfishes (Loricariidae, Pterygoplichthys spp.) in the Santa Fe River drainage, Suwannee River basin, USA

    Science.gov (United States)

    Nico, Leo G.; Butt, Peter L.; Johnston, Gerald R.; Jelks, Howard L.; Kail, Matthew; Walsh, Stephen J.

    2012-01-01

    We report on the occurrence of South American suckermouth armored catfishes (Loricariidae) in the Suwannee River basin, southeastern USA. Over the past few years (2009-2012), loricariid catfishes have been observed at various sites in the Santa Fe River drainage, a major tributary of the Suwannee in the state of Florida. Similar to other introduced populations of Pterygoplichthys, there is high likelihood of hybridization. To date, we have captured nine specimens (270-585 mm, standard length) in the Santa Fe River drainage. One specimen taken from Poe Spring best agrees with Pterygoplichthys gibbiceps (Kner, 1854) or may be a hybrid with either P. pardalis or P. disjunctivus. The other specimens were taken from several sites in the drainage and include seven that best agree with Pterygoplichthys disjunctivus (Weber, 1991); and one a possible P. disjunctivus x P. pardalis hybrid. We observed additional individuals, either these or similar appearing loricariids, in Hornsby and Poe springs and at various sites upstream and downstream of the long (> 4 km) subterranean portion of the Santa Fe River. These specimens represent the first confirmed records of Pterygoplichthys in the Suwannee River basin. The P. gibbiceps specimen represents the first documented record of an adult or near adult of this species in open waters of North America. Pterygoplichthys disjunctivus or its hybrids (perhaps hybrid swarms) are already abundant and widespread in other parts of peninsular Florida, but the Santa Fe River represents a northern extension of the catfish in the state. Pterygoplichthys are still relatively uncommon in the Santa Fe drainage and successful reproduction not yet documented. However, in May 2012 we captured five adult catfish (two mature or maturing males and three gravid females) from a single riverine swallet pool. One male was stationed at a nest burrow (no eggs present). To survive the occasional harsh Florida winters, these South American catfish apparently use

  13. S6K1 is involved in polyploidization through its phosphorylation at Thr421/Ser424.

    Science.gov (United States)

    Ma, Dongchu; Yu, Huiying; Lin, Di; Sun, Yinghui; Liu, Liping; Liu, Yage; Dai, Bing; Chen, Wei; Cao, Jianping

    2009-04-01

    Studies on polyploidization of megakaryocytes have been hampered by the lack of synchronized polyploid megakaryocytes. In this study, a relatively synchronized polyploid cell model was successfully established by employing Dami cells treated with nocodazole. In nocodazole-induced cells, cyclin B expression oscillated normally as in diploid cells and polyploid megakaryocytes. By using the nocodazole-induced Dami cell model, we found that 4E-BP1 and Thr421/Ser424 of ribosomal S6 kinase 1(S6K1) were phosphorylated mostly at M-phase in cytoplasm and oscillated in nocodazole-induced polyploid Dami cells, concomitant with increased expression of p27 and cyclin D3. However, phosphorylation of 4E-BP1 and S6K1 on Thr421/Ser424 was significantly decreased in differentiated Dami cells induced by phorbol 12-myristate 13-acetate (PMA), concomitant with increased expression of cyclin D1 and p21 and cyclin D3. Overexpression of the kinase dead form of S6K1 containing the mutation Lys 100 --> Gln in PMA-induced Dami cells increased ploidy whereas overexpression of rapamycin-resistant form of S6K1 containing the mutations Thr421 --> Glu and Ser424 --> Asp significantly dephosphorylated 4E-BP1 and reduced expression of cyclin D1, cyclin D3, p21 and p27, and slightly decreased the ploidy of PMA-induced Dami cells, compared with treatment with PMA alone. Moreover, overexpression of rapamycin-resistant form of S6K1 significantly reversed polyploidization of nocodazole-induced Dami cells. Furthermore, MAP (a novel compound synthesized recently) partly blocked the phosphorylation of S6K1 on Thr421/Ser424 and decreased the expression of p27 and polyploidization in nocodazole-induced Dami cells. Taken together, these data suggested that S6K1/4E-BP1 pathway may play an important role in polyploidization of megakaryocytes. (c) 2008 Wiley-Liss, Inc.

  14. Induction of hepatocyte polyploidization in rats of different age by ionizing radiation of different LET

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.

    1992-01-01

    A decrease in the effectiveness of neutron-irradiation with respect to fusion of nonproliferating hepatocytes of animals with age was shown by the method of flow cytometry. There was an inverse relationship between the effectiveness of induction of non-proliferating hepatocytes fusion and neutron energy. The process of hepatocyte fusion induced by neutrons was inhibited by uranyl acetate. No age-dependent changes were noted in the induction of polyploidization of proliferating hepatocytes by sparsely ionizing radiation. A hypothesis is proposed concerning a membrane nature of the target responsible for hepatocyte polyploidization induced by densely ionizing radiation. (authors). 8 refs., 4 figs., 5 tabs

  15. Induction of hepatocyte polyploidization in rats of different age by ionizing radiation of different LET

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.

    1990-01-01

    A decrease in the effectiveness of neutron-irradiation with respect to fusion of nonproliferating hepatocytes of animals with age was shown by the method of flow cytometry. There was an inverse relationship between the effectiveness of induction of non-proliferating hepatocytes fusion and neutron energy. The process of hepatocyte fusion induced by neutrons was inhibited by uranyl acetate. No age-dependent changes were noted in the induction of polyploidization of proliferating hepatocytes by sparsely ionizing radiation. A hypothesis is proposed concerning a membrane nature of the target responsible for hepatocyte polyploidization induced by densely ionizing radiation

  16. Genetics, Gene Flow, and Glaciation: The Case of the South American Limpet Nacella mytilina.

    Directory of Open Access Journals (Sweden)

    Claudio A González-Wevar

    Full Text Available Glacial episodes of the Quaternary, and particularly the Last Glacial Maximum (LGM drastically altered the distribution of the Southern-Hemisphere biota, principally at higher latitudes. The irregular coastline of Patagonia expanding for more than 84.000 km constitutes a remarkable area to evaluate the effect of Quaternary landscape and seascape shifts over the demography of near-shore marine benthic organisms. Few studies describing the biogeographic responses of marine species to the LGM have been conducted in Patagonia, but existing data from coastal marine species have demonstrated marked genetic signatures of post-LGM recolonization and expansion. The kelp-dweller limpet Nacella mytilina is broadly distributed along the southern tip of South America and at the Falkland/Malvinas Islands. Considering its distribution, abundance, and narrow bathymetry, N. mytilina represents an appropriate model to infer how historical and contemporary processes affected the distribution of intraspecific genetic diversity and structure along the southern tip of South America. At the same time, it will be possible to determine how life history traits and the ecology of the species are responsible for the current pattern of gene flow and connectivity across the study area. We conducted phylogeographic and demographic inference analyses in N. mytilina from 12 localities along Pacific Patagonia (PP and one population from the Falkland/Malvinas Islands (FI. Analyses of the mitochondrial gene COI in 300 individuals of N. mytilina revealed low levels of genetic polymorphism and the absence of genetic differentiation along PP. In contrast, FI showed a strong and significant differentiation from Pacific Patagonian populations. Higher levels of genetic diversity were also recorded in the FI population, together with a more expanded genealogy supporting the hypothesis of glacial persistence of the species in these islands. Haplotype genealogy, and mismatch analyses in

  17. A numerical study of the Plata River plume along the southeastern South American continental shelf

    Directory of Open Access Journals (Sweden)

    Felipe M. Pimenta

    2005-12-01

    Full Text Available The Rio de la Plata, one of the largest rivers on Earth, discharges into the ocean waters from basin that covers a large area of South America. Its plume extends along northern Argentina, Uruguay, and southern Brazil shelves strongly influencing the ecosystems. In spite of this, little is known about the mechanisms that control it. Here we report results of simulations with POM carried out to investigate the roles of wind and river discharge in Plata plume dynamics. Different outflows were explored, including an average climatological value and magnitudes representative of La Niña and El Niño. Forcing the model with river discharge the average plume speed was directly related to the outflow intensity. The Plata northward extension varied from 850 to 1550 km and for average discharge a band of low salinity waters formed from the estuary up to 30ºN of South Brazilian Shelf. Upwelling and downwelling winds were applied after 130 days. The distribution of low salinity waters over the shelf was more sensitive to the wind direction than to the river outflow variability. Downwelling winds were very capable of advecting the low salinity signal downshelf. Upwelling winds were efficient in eroding the plume, which was basically detached from the coast by Ekman drift. Abnormal plume intrusions toward low latitudes may be a result of the original plume position coupled with events of persistent strong downwelling favorable winds.O Rio da Prata, um dos maiores rios da Terra, descarrega no oceano águas de uma bacia de drenagem que cobre uma ampla área da América do Sul. Sua pluma extende-se ao longo do norte da Argentina, Uruguay e sul do Brasil influenciando amplamente os ecossistemas costeiros. A despeito disso, pouco se sabe a respeito dos mecanismos que a controlam. Relatamos aqui simulações conduzidas com o modelo POM na investigação do papel dos ventos e da descarga fluvial na dinâmica da pluma do Prata. Descargas com valores médios climatol

  18. Genetics, Gene Flow, and Glaciation: The Case of the South American Limpet Nacella mytilina

    Science.gov (United States)

    González-Wevar, Claudio A.; Rosenfeld, Sebastián; Segovia, Nicolás I.; Hüne, Mathias; Gérard, Karin; Ojeda, Jaime; Mansilla, Andrés; Brickle, Paul; Díaz, Angie; Poulin, Elie

    2016-01-01

    Glacial episodes of the Quaternary, and particularly the Last Glacial Maximum (LGM) drastically altered the distribution of the Southern-Hemisphere biota, principally at higher latitudes. The irregular coastline of Patagonia expanding for more than 84.000 km constitutes a remarkable area to evaluate the effect of Quaternary landscape and seascape shifts over the demography of near-shore marine benthic organisms. Few studies describing the biogeographic responses of marine species to the LGM have been conducted in Patagonia, but existing data from coastal marine species have demonstrated marked genetic signatures of post-LGM recolonization and expansion. The kelp-dweller limpet Nacella mytilina is broadly distributed along the southern tip of South America and at the Falkland/Malvinas Islands. Considering its distribution, abundance, and narrow bathymetry, N. mytilina represents an appropriate model to infer how historical and contemporary processes affected the distribution of intraspecific genetic diversity and structure along the southern tip of South America. At the same time, it will be possible to determine how life history traits and the ecology of the species are responsible for the current pattern of gene flow and connectivity across the study area. We conducted phylogeographic and demographic inference analyses in N. mytilina from 12 localities along Pacific Patagonia (PP) and one population from the Falkland/Malvinas Islands (FI). Analyses of the mitochondrial gene COI in 300 individuals of N. mytilina revealed low levels of genetic polymorphism and the absence of genetic differentiation along PP. In contrast, FI showed a strong and significant differentiation from Pacific Patagonian populations. Higher levels of genetic diversity were also recorded in the FI population, together with a more expanded genealogy supporting the hypothesis of glacial persistence of the species in these islands. Haplotype genealogy, and mismatch analyses in the FI population

  19. Particulate matter levels in a South American megacity: the metropolitan area of Lima-Callao, Peru.

    Science.gov (United States)

    Silva, Jose; Rojas, Jhojan; Norabuena, Magdalena; Molina, Carolina; Toro, Richard A; Leiva-Guzmán, Manuel A

    2017-11-13

    The temporal and spatial trends in the variability of PM 10 and PM 2.5 from 2010 to 2015 in the metropolitan area of Lima-Callao, Peru, are studied and interpreted in this work. The mean annual concentrations of PM 10 and PM 2.5 have ranges (averages) of 133-45 μg m -3 (84 μg m -3 ) and 35-16 μg m -3 (26 μg m -3 ) for the monitoring sites under study. In general, the highest annual concentrations are observed in the eastern part of the city, which is a result of the pattern of persistent local winds entering from the coast in a south-southwest direction. Seasonal fluctuations in the particulate matter (PM) concentrations are observed; these can be explained by subsidence thermal inversion. There is also a daytime pattern that corresponds to the peak traffic of a total of 9 million trips a day. The PM 2.5 value is approximately 40% of the PM 10 value. This proportion can be explained by PM 10 re-suspension due to weather conditions. The long-term trends based on the Theil-Sen estimator reveal decreasing PM 10 concentrations on the order of -4.3 and -5.3% year -1 at two stations. For the other stations, no significant trend is observed. The metropolitan area of Lima-Callao is ranked 12th and 16th in terms of PM 10 and PM 2.5 , respectively, out of 39 megacities. The annual World Health Organization thresholds and national air quality standards are exceeded. A large fraction of the Lima population is exposed to PM concentrations that exceed protection thresholds. Hence, the development of pollution control and reduction measures is paramount.

  20. Complications in laparoscopic radical cystectomy: The South American experience with 59 cases

    Directory of Open Access Journals (Sweden)

    Octavio A. Castillo

    2006-06-01

    Full Text Available OBJECTIVE: In this study, we have gathered the second largest series yet published on laparoscopic radical cystectomy in order to evaluate the incidence and cause of intra and postoperative complication, conversion to open surgery, and patient mortality. MATERIALS AND METHODS: From 1997 to 2005, 59 laparoscopic radical cystectomies were performed for the management of bladder cancer at 3 institutions in South America. Twenty nine patients received continent urinary diversion, including 25 orthotopic ileal neobladders and 4 Indiana pouches. Only one case of continent urinary diversion was performed completely intracorporeally. RESULTS: Mean operative time was 337 minutes (150-600. Estimated intraoperative blood loss was 488 mL (50-1500 and 12 patients (20% required blood transfusion. All 7 (12% intraoperative complications were vascular in nature, that is, 1 epigastric vessel injury, 2 injuries to the iliac vessels (1 artery and 1 vein, and 4 bleedings that occurred during the bladder pedicles control. Eighteen (30% postoperative complications (not counting mortalities occurred, including 3 urinary tract infections, 1 pneumonia, 1 wound infection, 5 ileus, 2 persistent chylous drainage, 3 urinary fistulas, and 3 (5% postoperative complications that required surgical intervention (2 hernias - one in the port site and one in the extraction incision, and 1 bowel obstruction. One case (1.7% was electively converted to open surgery due to a larger tumor that precluded proper posterior dissection. Two mortalities (3.3% occurred in this series, one early mortality due to uncontrolled upper gastrointestinal bleeding and one late mortality following massive pulmonary embolism. CONCLUSIONS: Laparoscopic radical cystectomy is a safe operation with morbidity and mortality rates comparable to the open surgery.

  1. Holocene Multi-Decadal to Millennial-Scale Hydrologic Variability on the South American Altiplano

    Science.gov (United States)

    Fritz, S. C.; Baker, P. A.; Ekdahl, E.; Burns, S.

    2006-12-01

    On orbital timescales, lacustrine sediment records in the tropical central Andes show massive changes in lake level due to mechanisms related to global-scale drivers, varying at precessional timescales. Here we use stable isotopic and diatom records from two lakes in the Lake Titicaca drainage basin to reconstruct multi- decadal to millennial scale precipitation variability during the last 7000 to 8000 years. The records are tightly coupled at multi-decadal to millennial scales with each other and with lake-level fluctuations in Lake Titicaca, indicating that the lakes are recording a regional climate signal. A quantitative reconstruction of precipitation from stable isotopic data indicates that the central Andes underwent significant wet to dry alternations at multi- centennial frequencies with an amplitude of 30 to 40% of total precipitation. A strong millennial-scale component, similar in duration to periods of increased ice rafted debris flux in the North Atlantic, is observed in both lake records, suggesting that tropical North Atlantic sea-surface temperature (SST) variability may partly control regional precipitation. No clear relationship is evident between these records and the inferred ENSO history from Lago Pallcacocha in the northern tropical Andes. In the instrumental period, regional precipitation variability on inter-annual timescales is clearly influenced by Pacific modes; for example, most El Ninos produce dry and warm conditions in this part of the central Andes. However, on longer timescales, the control of tropical Pacific modes is less clear. Our reconstructions suggest that the cold intervals of the Holocene Bond events are periods of increased precipitation in the central Andes, thus indicating an anti-phasing of precipitation variation in the southern tropics of South America relative to the Northern Hemisphere monsoon region.

  2. Digging Deeper: A Case Study of Farmer Conceptualization of Ecosystem Services in the American South.

    Science.gov (United States)

    Quinn, Courtney E; Quinn, John E; Halfacre, Angela C

    2015-10-01

    The interest in improved environmental sustainability of agriculture via biodiversity provides an opportunity for placed-based research on the conceptualization and articulation of ecosystem services. Yet, few studies have explored how farmers conceptualize the relationship between their farm and nature and by extension ecosystem services. Examining how farmers in the Southern Piedmont of South Carolina discuss and explain the role of nature on their farm, we create a detail-rich picture of how they perceive ecosystem services and their contributions to the agroeconomy. Using 34 semi-structured interviews, we developed a detail-rich qualitative portrait of these farmers' conceptualizations of ecosystem services. Farmers' conceptualization of four ecosystem services: provisioning, supporting, regulating, and cultural are discussed, as well as articulation of disservices. Results of interviews show that most interviewees expressed a basic understanding of the relationship between nature and agriculture and many articulated benefits provided by nature to their farm. Farmers referred indirectly to most services, though they did not attribute services to biodiversity or ecological function. While farmers have a general understanding and appreciation of nature, they lack knowledge on specific ways biodiversity benefits their farm. This lack of knowledge may ultimately limit farmer decision-making and land management to utilize ecosystem services for environmental and economic benefits. These results suggest that additional communication with farmers about ecosystem services is needed as our understanding of these benefits increases. This change may require collaboration between conservation biology professionals and extension and agriculture professionals to extended successful biomass provisioning services to other ecosystem services.

  3. Ancestry dynamics in a South American population: The impact of gene flow and preferential mating.

    Science.gov (United States)

    Hedrick, Philip W

    2017-07-01

    European ancestry in many populations in Latin America at autosomal loci is often higher than that from X-linked loci indicating more European male ancestry and more Amerindian female ancestry. Generally, this has been attributed to more European male gene flow but could also result from an advantage to European mating or reproductive success. Population genetic models were developed to investigate the dynamics of gene flow and mating or reproductive success. Using estimates of autosomal and X-chromosome European ancestry, the amount of male gene flow or mating or reproductive advantage for Europeans, or those with European ancestry, was estimated. In a population from Antioquia, Colombia with an estimated 79% European autosomal ancestry and an estimated 69% European X-chromosome ancestry, about 15% male gene flow from Europe or about 20% mating or reproductive advantage of Europeans over Amerindians resulted in these levels of European ancestry in the contemporary population. Combinations of gene flow and mating advantage were nearly additive in their impact. Gene flow, mating advantage, or a combination of both factors, are consistent with observed levels of European ancestry in a Latin American population. This approach provides a general methodology to determine the levels of gene flow and mating differences that can explain the observed contemporary differences in ancestry from autosomes and X-chromosomes. © 2017 Wiley Periodicals, Inc.

  4. Ancient female philopatry, asymmetric male gene flow, and synchronous population expansion support the influence of climatic oscillations on the evolution of South American sea lion (Otaria flavescens.

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    Larissa Rosa de Oliveira

    Full Text Available The South American sea lion (Otaria flavescens is widely distributed along the southern Atlantic and Pacific coasts of South America with a history of significant commercial exploitation. We aimed to evaluate the population genetic structure and the evolutionary history of South American sea lion along its distribution by analyses of mitochondrial DNA (mtDNA and 10 nuclear microsatellites loci. We analyzed 147 sequences of mtDNA control region and genotyped 111 individuals of South American sea lion for 10 microsatellite loci, representing six populations (Peru, Northern Chile, Southern Chile, Uruguay (Brazil, Argentina and Falkland (Malvinas Islands and covering the entire distribution of the species. The mtDNA phylogeny shows that haplotypes from the two oceans comprise two very divergent clades as observed in previous studies, suggesting a long period (>1 million years of low inter-oceanic female gene flow. Bayesian analysis of bi-parental genetic diversity supports significant (but less pronounced than mitochondrial genetic structure between Pacific and Atlantic populations, although also suggested some inter-oceanic gene flow mediated by males. Higher male migration rates were found in the intra-oceanic population comparisons, supporting very high female philopatry in the species. Demographic analyses showed that populations from both oceans went through a large population expansion ~10,000 years ago, suggesting a very similar influence of historical environmental factors, such as the last glacial cycle, on both regions. Our results support the proposition that the Pacific and Atlantic populations of the South American sea lion should be considered distinct evolutionarily significant units, with at least two managements units in each ocean.

  5. Ancient female philopatry, asymmetric male gene flow, and synchronous population expansion support the influence of climatic oscillations on the evolution of South American sea lion (Otaria flavescens)

    Science.gov (United States)

    Gehara, Marcelo C. M.; Fraga, Lúcia D.; Lopes, Fernando; Túnez, Juan Ignacio; Cassini, Marcelo H.; Majluf, Patricia; Cárdenas-Alayza, Susana; Pavés, Héctor J.; Crespo, Enrique Alberto; García, Nestor; Loizaga de Castro, Rocío; Hoelzel, A. Rus; Sepúlveda, Maritza; Olavarría, Carlos; Valiati, Victor Hugo; Quiñones, Renato; Pérez-Alvarez, Maria Jose; Ott, Paulo Henrique

    2017-01-01

    The South American sea lion (Otaria flavescens) is widely distributed along the southern Atlantic and Pacific coasts of South America with a history of significant commercial exploitation. We aimed to evaluate the population genetic structure and the evolutionary history of South American sea lion along its distribution by analyses of mitochondrial DNA (mtDNA) and 10 nuclear microsatellites loci. We analyzed 147 sequences of mtDNA control region and genotyped 111 individuals of South American sea lion for 10 microsatellite loci, representing six populations (Peru, Northern Chile, Southern Chile, Uruguay (Brazil), Argentina and Falkland (Malvinas) Islands) and covering the entire distribution of the species. The mtDNA phylogeny shows that haplotypes from the two oceans comprise two very divergent clades as observed in previous studies, suggesting a long period (>1 million years) of low inter-oceanic female gene flow. Bayesian analysis of bi-parental genetic diversity supports significant (but less pronounced than mitochondrial) genetic structure between Pacific and Atlantic populations, although also suggested some inter-oceanic gene flow mediated by males. Higher male migration rates were found in the intra-oceanic population comparisons, supporting very high female philopatry in the species. Demographic analyses showed that populations from both oceans went through a large population expansion ~10,000 years ago, suggesting a very similar influence of historical environmental factors, such as the last glacial cycle, on both regions. Our results support the proposition that the Pacific and Atlantic populations of the South American sea lion should be considered distinct evolutionarily significant units, with at least two managements units in each ocean. PMID:28654647

  6. Production of a high-efficiency TILLING population through polyploidization.

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    Tsai, Helen; Missirian, Victor; Ngo, Kathie J; Tran, Robert K; Chan, Simon R; Sundaresan, Venkatesan; Comai, Luca

    2013-04-01

    Targeting Induced Local Lesions in Genomes (TILLING) provides a nontransgenic method for reverse genetics that is widely applicable, even in species where other functional resources are missing or expensive to build. The efficiency of TILLING, however, is greatly facilitated by high mutation density. Species vary in the number of mutations induced by comparable mutagenic treatments, suggesting that genetic background may affect the response. Allopolyploid species have often yielded higher mutation density than diploids. To examine the effect of ploidy, we autotetraploidized the Arabidopsis (Arabidopsis thaliana) ecotype Columbia, whose diploid has been used for TILLING extensively, and mutagenized it with 50 mm ethylmethane sulfonate. While the same treatment sterilized diploid Columbia, the tetraploid M1 plants produced good seed. To determine the mutation density, we searched 528 individuals for induced mutations in 15 genes for which few or no knockout alleles were previously available. We constructed tridimensional pools from the genomic DNA of M2 plants, amplified target DNA, and subjected them to Illumina sequencing. The results were analyzed with an improved version of the mutation detection software CAMBa that accepts any pooling scheme. This small population provided a rich resource with approximately 25 mutations per queried 1.5-kb fragment, including on average four severe missense and 1.3 truncation mutations. The overall mutation density of 19.4 mutations Mb(-1) is 4 times that achieved in the corresponding diploid accession, indicating that genomic redundancy engenders tolerance to high mutation density. Polyploidization of diploids will allow the production of small populations, such as less than 2,000, that provide allelic series from knockout to mild loss of function for virtually all genes.

  7. The effect of polyploidization on tree hydraulic functioning.

    Science.gov (United States)

    De Baerdemaeker, Niels J F; Hias, Niek; Van den Bulcke, Jan; Keulemans, Wannes; Steppe, Kathy

    2018-02-01

    Recent research has highlighted the importance of living tissue in wood. Polyploidization can impact amounts and arrangements of living cells in wood, potentially leading to increased drought tolerance. Tetraploid variants were created from the apple cultivar Malus ×domestica 'Gala' (Gala-4x), and their vulnerability to drought-induced cavitation and their hydraulic capacitance were compared to those of their diploid predecessors (Gala-2x). Assuming a positive correlation between polyploidy and drought tolerance, we hypothesized lower vulnerability and higher capacitance for the tetraploid. Vulnerability to drought-induced cavitation and the hydraulic capacitance were quantified through acoustic emission and continuous weighing of shoots during a bench-top dehydration experiment. To underpin the hydraulic trait results, anatomical variables such as vessel area, conduit diameter, cell wall reinforcement, and ray and vessel-associated parenchyma were measured. Vulnerability to drought-induced cavitation was intrinsically equal for both ploidy variants, but Gala-4x proved to be more vulnerable than Gala-2x during the early phase of desiccation as was indicated by its significantly lower air entry value. Higher change in water content of the leafy shoot, higher amount of parenchyma, and larger vessel area and size resulted in a significantly higher hydraulic capacitance and efficiency for Gala-4x compared to Gala-2x. Both ploidy variants were typified as highly sensitive to drought-induced cavitation, with no significant difference in their overall drought vulnerability. But, when water deficit is short and moderate, Gala-4x may delay a drought-induced decrease in performance by trading hydraulic safety for increased release of capacitively stored water from living tissue. © 2018 Botanical Society of America.

  8. Segregation analysis of microsatellite (SSR) markers in sugarcane polyploids.

    Science.gov (United States)

    Lu, X; Zhou, H; Pan, Y-B; Chen, C Y; Zhu, J R; Chen, P H; Li, Y-R; Cai, Q; Chen, R K

    2015-12-28

    No information is available on segregation analysis of DNA markers involving both pollen and self-progeny. Therefore, we used capillary electrophoresis- and fluorescence-based DNA fingerprinting together with single pollen collection and polymerase chain reaction (PCR) to investigate simple sequence repeat (SSR) marker segregation among 964 single pollens and 288 self-progenies (S1) of sugarcane cultivar LCP 85-384. Twenty SSR DNA fragments (alleles) were amplified by five polymorphic SSR markers. Only one non-parental SSR allele was observed in 2392 PCRs. SSR allele inheritance was in accordance with Mendelian laws of segregation and independent assortment. Highly significant correlation coefficients were found between frequencies of observed and expected genotypes in pollen and S1 populations. Within the S1 population, the most frequent genotype of each SSR marker was the parental genotype of the same marker. The number of genotypes was higher in pollen than S1 population. PIC values of the five SSR markers were greater in pollen than S1 populations. Eleven of 20 SSR alleles (55%) were segregated in accordance with Mendelian segregation ratios expected from pollen and S1 populations of a 2n = 10x polyploid. Six of 20 SSR alleles were segregated in a 3:1 (presence:absence) ratio and were simplex markers. Four and one alleles were segregated in 77:4 and 143:1 ratios and considered duplex and triplex markers, respectively. Segregation ratios of remaining alleles were unexplainable. The results provide information about selection of crossing parents, estimation of seedling population optimal size, and promotion of efficient selection, which may be valuable for sugarcane breeders.

  9. Maternal Education Gradients in Infant Health in Four South American Countries.

    Science.gov (United States)

    Wehby, George L; López-Camelo, Jorge S

    2017-11-01

    Objective We investigate gradients (i.e. differences) in infant health outcomes by maternal education in Argentina, Brazil, Chile, and Venezuela and explore channels related to father's education, household labor outcomes, and maternal health, fertility, and use of prenatal services and technology. Methods We employ secondary interview and birth record data similarly collected across a network of birth hospitals from the early 1980s through 2011 within the Latin American Collaborative Study of Congenital Anomalies (ECLAMC). Focusing on children without birth defects, we estimate gradients in several infant health outcomes including birth weight, gestational age, and hospital discharge status by maternal education using ordinary least squares regression models adjusting for several demographic factors. To explore channels, we add as covariates father's education, parental occupational activity, maternal health and fertility history, and use of prenatal services and technology and evaluate changes in the coefficient of maternal education. We use the same models for each country sample. Results We find important differences in gradients across countries. We find evidence for educational gradients in preterm birth in three countries but weaker evidence for gradients in fetal growth. The extent to which observed household and maternal factors explain these gradients based on changes in the regression coefficient of maternal education when controlling for these factors as covariates also varies between countries. In contrast, we generally find evidence across all countries that higher maternal education is associated with increased use of prenatal care services and technology. Conclusions Our findings suggest that differences in infant health by maternal education and their underlying mechanisms vary and are not necessarily generalizable across countries. However, the positive association between maternal education and use of prenatal services and technology is more

  10. Main animal welfare problems in ruminant livestock during preslaughter operations: a South American view.

    Science.gov (United States)

    Gallo, C B; Huertas, S M

    2016-02-01

    Animals destined for meat production are usually exposed to many stressful conditions during production and particularly during preslaughter operations. Handling animals on farm, loading into and unloading from vehicles, transportation, passing through livestock markets, fasting, lairage and stunning can all affect their welfare. How badly welfare can be affected will depend on both the intrinsic factors of the specific type of animal involved and the extrinsic factors of the environment where those animals live or are being handled, including the animal handlers. In South America (SA), it has been part of a strategy for improving animal welfare (AW) to address not only ethical aspects, but to emphasize the close relationship existing between handling ruminants preslaughter and the quantity and quality of the meat they produce. This has resulted not only in improvements in AW, but has also brought economic rewards to producers which in turn can lead to higher incomes for them and hence better human welfare. For producers with a high number of animals, considering AW during production and preslaughter operations can determine the possibility of exporting and/or getting better prices for their products. At smallfarmer level, particularly in some less developed countries, where human welfare is impaired, using this strategy together with education has also been relevant. It is important that education and training in AW are done not only considering global knowledge, but also including specific geographical and climatic characteristics of each country and the cultural, religious and socio-economical characteristics of its people; therefore, research within the context of each country or region becomes relevant. The aim of this review was to show the results of research dealing with AW of ruminant livestock in Chile and some other SA countries. Some of the main problems encountered are related to lack of proper infrastructure to handle animals; long distance transport

  11. Perceived social stress, pregnancy-related anxiety, depression and subjective social status among pregnant Mexican and Mexican American women in south Texas.

    Science.gov (United States)

    Fleuriet, K Jill; Sunil, T S

    2014-05-01

    The purpose of this study was to determine differences in subjective social status, perceived social stress, depressive symptoms, and pregnancy-related anxiety between pregnant Mexican American and Mexican immigrant women. Three hundred pregnant Mexican immigrant and Mexican American women in South Texas were surveyed for pregnancy-related anxiety, perceived social stress, depressive symptoms, and subjective social status. Pregnant Mexican immigrant women had higher levels of pregnancy-related anxiety and lower levels of depression and perceived social stress than pregnant Mexican American women. Change in these variables among Mexican immigrant women was relatively linear as time of residence in the United States increased. Mexican immigrant and Mexican American women had significantly different correlations between subjective social status, self-esteem and perceived social stress. Results indicate that subjective social status is an important psychosocial variable among pregnant Hispanic women. Results contribute to ongoing efforts to provide culturally responsive prenatal psychosocial support services.

  12. Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary

    Science.gov (United States)

    Amarilla, Leonardo D.; Anton, Ana M.; Chiapella, Jorge O.; Manifesto, María M.; Angulo, Diego F.; Sosa, Victoria

    2015-01-01

    The South American Transition Zone (SATZ) is a biogeographic area in which not only orogeny (Andes uplift) and climate events (aridification) since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species’ range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2–1.2) Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity. PMID:26110533

  13. Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary.

    Directory of Open Access Journals (Sweden)

    Leonardo D Amarilla

    Full Text Available The South American Transition Zone (SATZ is a biogeographic area in which not only orogeny (Andes uplift and climate events (aridification since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species' range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2-1.2 Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity.

  14. Regionally heterogeneous paleoenvironmental responses in the West African and South American monsoon systems on glacial to millennial timescales

    Science.gov (United States)

    Shanahan, T. M.; Hughen, K. A.; van Mooy, B.; Overpeck, J. T.; Baker, P. A.; Fritz, S.; Peck, J. A.; Scholz, C. A.; King, J. W.

    2008-12-01

    Although millennial-scale paleoenvironmental changes have been well characterized for high latitude sites, short-term climate variability in the tropics is less well understood. While the Intertropical Convergence Zone may act as an integrator of tropical climate changes, regional factors also play an important role in controlling the tropical response to climate forcing. Understanding these influences, and how they modulate the response to global climate forcing under different mean climate states is thus important for assessing how the tropics may respond to future climate change. Here, we examine new centennial-resolution records of paleoenvironmental change from isotopic and relative abundance data from molecular biomarkers in sediment cores from Lake Bosumtwi and Lake Titicaca. We assess the relative response of the West African and South American monsoon systems to millennial and suborbital-scale climate variability over the last ca. 30,000 years. While there is evidence for synchronous climate variability in the two systems, the dominant paleoenvironmental changes appear largely decoupled, highlighting the importance of regional climatology in controlling the response to climate forcing in tropical regions.

  15. Quaternary glaciation and hydrologic variation in the South American tropics as reconstructed from the Lake Titicaca drilling project

    Science.gov (United States)

    Fritz, Sherilyn C.; Baker, Paul A.; Seltzer, Geoffrey O.; Ballantyne, Ashley; Tapia, Pedro; Cheng, Hai; Edwards, R. Lawrence

    2007-11-01

    A 136-m-long drill core of sediments was recovered from tropical high-altitude Lake Titicaca, Bolivia-Peru, enabling a reconstruction of past climate that spans four cycles of regional glacial advance and retreat and that is estimated to extend continuously over the last 370,000 yr. Within the errors of the age model, the periods of regional glacial advance and retreat are concordant respectively with global glacial and interglacial stages. Periods of ice advance in the southern tropical Andes generally were periods of positive water balance, as evidenced by deeper and fresher conditions in Lake Titicaca. Conversely, reduced glaciation occurred during periods of negative water balance and shallow closed-basin conditions in the lake. The apparent coincidence of positive water balance of Lake Titicaca and glacial growth in the adjacent Andes with Northern Hemisphere ice sheet expansion implies that regional water balance and glacial mass balance are strongly influenced by global-scale temperature changes, as well as by precessional forcing of the South American summer monsoon.

  16. Assessing European egg parasitoids as a mean of controlling the invasive South American tomato pinworm Tuta absoluta.

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    Anaïs Chailleux

    Full Text Available The South American tomato pinworm (Tuta absoluta has recently invaded Europe and is rapidly spreading in the Afro-Eurasian continent where it is becoming a major pest on tomato crops. Laboratory tests were undertaken to evaluate the potential of 29 European strains of Trichogramma parasitoids to control T. absoluta. In addition to the host itself, the host plant (tomato was used during the laboratory tests in order to increase the chance of selecting the best parasitoid strains. Trichogramma females were placed with T. absoluta eggs on a tomato leaflet in tubes. We compared the parasitism of T. absoluta by the various Trichogramma species tested to the Trichogramma species currently commercially available for the pest control in Europe, i.e. Trichogramma achaeae. Thereafter, the more promising strains were tested on a larger scale, in mesocosm (i.e. cages in greenhouses and in greenhouse compartments to evaluate efficiency of laboratory selected strains under cropping conditions. The most efficient strain from the laboratory screening trials did not perform as efficiently under the greenhouse conditions. We discuss differences in parasitism levels among species and strains and among the different scales tested in the experiments, as well as implications of these results for further screening for biocontrol agents.

  17. Kelp and dolphin gulls cause perineal wounds in South American fur seal pups (Arctocephalus australis) at Guafo Island, Chilean Patagonia.

    Science.gov (United States)

    Seguel, Mauricio; Muñoz, Francisco; Montalva, Felipe; Perez-Venegas, Diego; Pavés, Héctor; Gottdenker, Nicole

    2017-07-01

    During five reproductive seasons, we documented the presence, extent and origin of perineal wounds in South American fur seal pups ( Arctocephalus australis ) on Guafo Island, Northern Chilean Patagonia. The seasonal prevalence of perineal wounds ranged from 5 to 9%, and new cases were more common at the end of the breeding season (February), when pups were on average two months old and were actively expelling hookworms ( Uncinaria sp). Histologically, wounds corresponded to marked ulcerative lymphoplasmacytic and histiocytic dermatitis with granulation tissue and mixed bacterial colonies. In 2015 and 2017, kelp gulls ( Larus dominicanus ) and dolphin gulls ( Leucophaeus scoresbii ) were observed picking and wounding the perineal area of marked pups. This behaviour occurred more frequently after the pups' defecation, when sea gulls engaged in consumption of pups' faeces. The affected pups usually had moderate to marked hookworm infections along with bloody diarrhoea and anaemia. Pups with severe wounds (23% of affected animals) had swollen perineal areas and signs of secondary systemic bacterial infection. We propose that seagulls on Guafo Island have learned to consume remains of blood and parasites in the faeces of pups affected by hookworm infection, causing perineal wounds during this process. We conclude that this perineal wounding is an unintentional, occasional negative effect of an otherwise commensal gull-fur seal relationship.

  18. Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary.

    Science.gov (United States)

    Amarilla, Leonardo D; Anton, Ana M; Chiapella, Jorge O; Manifesto, María M; Angulo, Diego F; Sosa, Victoria

    2015-01-01

    The South American Transition Zone (SATZ) is a biogeographic area in which not only orogeny (Andes uplift) and climate events (aridification) since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species' range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2-1.2) Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity.

  19. Germ cell differentiation and proliferation in the developing testis of the South American plains viscacha, Lagostomus maximus (Mammalia, Rodentia).

    Science.gov (United States)

    Gonzalez, C R; Muscarsel Isla, M L; Fraunhoffer, N A; Leopardo, N P; Vitullo, A D

    2012-08-01

    Cell proliferation and cell death are essential processes in the physiology of the developing testis that strongly influence the normal adult spermatogenesis. We analysed in this study the morphometry, the expression of the proliferation cell nuclear antigen (PCNA), cell pluripotency marker OCT-4, germ cell marker VASA and apoptosis in the developing testes of Lagostomus maximus, a rodent in which female germ line develops through abolished apoptosis and unrestricted proliferation. Morphometry revealed an increment in the size of the seminiferous cords with increasing developmental age, arising from a significant increase of PCNA-positive germ cells and a stable proportion of PCNA-positive Sertoli cells. VASA showed a widespread cytoplasmic distribution in a great proportion of proliferating gonocytes that increased significantly at late development. In the somatic compartment, Leydig cells increased at mid-development, whereas peritubular cells showed a stable rate of proliferation. In contrast to other mammals, OCT-4 positive gonocytes increased throughout development reaching 90% of germ cells in late-developing testis, associated with a conspicuous increase in circulating FSH from mid- to late-gestation. TUNEL analysis was remarkable negative, and only a few positive cells were detected in the somatic compartment. These results show that the South American plains viscacha displays a distinctive pattern of testis development characterized by a sustained proliferation of germ cells throughout development, with no signs of apoptosis cell demise, in a peculiar endocrine in utero ambiance that seems to promote the increase of spermatogonial number as a primary direct effect of FSH.

  20. Differential influences of allometry, phylogeny and environment on the rostral shape diversity of extinct South American notoungulates

    Science.gov (United States)

    Gomes Rodrigues, Helder; Cornette, Raphaël; Clavel, Julien; Cassini, Guillermo; Bhullar, Bhart-Anjan S.; Fernández-Monescillo, Marcos; Moreno, Karen; Herrel, Anthony; Billet, Guillaume

    2018-01-01

    Understanding the mechanisms responsible for phenotypic diversification, and the associated underlying constraints and ecological factors represents a central issue in evolutionary biology. Mammals present a wide variety of sizes and shapes, and are characterized by a high number of morphological convergences that are hypothesized to reflect similar environmental pressures. Extinct South American notoungulates evolved in isolation from northern mammalian faunas in highly disparate environments. They present a wide array of skeletal phenotypes and convergences, such as ever-growing dentition. Here, we focused on the origins of the rostral diversity of notoungulates by quantifying the shape of 26 genera using three-dimensional geometric morphometric analysis. We tested the influence of allometry and phylogeny on rostral shape and evaluated rates of evolutionary change in the different clades. We found strong allometric and phylogenetic signals concerning the rostral shape of notoungulates. Despite convergent forms, we observed a diffuse diversification of rostral shape, with no significant evidence of influence by large-scaled environmental variation. This contrasts with the increase in dental crown height that occurred in four late-diverging families in response to similar environmental pressures. These results illustrate the importance of considering both biological components and evolutionary rates to better understand some aspects of phenotypic diversity.

  1. South American smoke coverage and flux estimations from the Fire Locating and Modeling of Burning Emissions (FLAMBE') system.

    Science.gov (United States)

    Reid, J. S.; Westphal, D. L.; Christopher, S. A.; Prins, E. M.; Gasso, S.; Reid, E.; Theisen, M.; Schmidt, C. C.; Hunter, J.; Eck, T.

    2002-05-01

    The Fire Locating and Modeling of Burning Emissions (FLAMBE') project is a joint Navy, NOAA, NASA and university project to integrate satellite products with numerical aerosol models to produce a real time fire and emissions inventory. At the center of the program is the Wildfire Automated Biomass Burning Algorithm (WF ABBA) which provides real-time fire products and the NRL Aerosol Analysis and Prediction System to model smoke transport. In this presentation we give a brief overview of the system and methods, but emphasize new estimations of smoke coverage and emission fluxes from the South American continent. Temporal and smoke patterns compare reasonably well with AERONET and MODIS aerosol optical depth products for the 2000 and 2001 fire seasons. Fluxes are computed by relating NAAPS output fields and MODIS optical depth maps with modeled wind fields. Smoke emissions and transport fluxes out of the continent can then be estimated by perturbing the modeled emissions to gain agreement with the satellite and wind products. Regional smoke emissions are also presented for grass and forest burning.

  2. Reproductive success of South American terns (Sterna hirundinacea from Cardos Islands, Florianópolis, SC, Brazil

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    Hélio A.A. Fracasso

    2012-06-01

    Full Text Available Sterna hirundinacea (Lesson, 1831 is a migratory seabird that breeds in the Pacific Coast (from Peru to Chile and along the Atlantic coast of South America from Espírito Santo (Brazil to Terra del Fuego (Argentina. This paper describes the reproductive success of South American Terns on Cardos Island, Florianopolis, Brazil in the breeding seasons of 2003, 2005 and 2006. The colony was formed in mid-May in 2003 and early April in other years, with the total number of nests ranging from 1,852 in 2006 to 2,486 in 2005. Hatching success was estimated at 76.39% in 2006, 62.73% in 2003 and 41.1% in 2005, the lowest value that could be attributed to predation by hawks Caracara plancus, lizards Tupinambis merianae and black vulture Coragyps atratus. The chicks hatched in July in 2003, and in June 2005 and 2006, and fledging success was 50.94%, 35.96 and 53.47% respectively. Cardos Island has been constantly used as a breeding site by South American Terns, and therefore represents an important area for conservation of this species. This success could be attributed to low pressure of Kelp gulls (Larus dominicanus, the main predator of seabirds along the Brazilian coast.Sterna hirundinacea (Lesson, 1831 é uma ave migratória que nidifica na costa do Pacífico (do Peru ao Chile e ao longo do Atlântico Sul do Espírito Santo (Brasil até a Terra do Fogo (Argentina. Este trabalho descreve o sucesso reprodutivo do trinta-réis do bico-vermelho na ilha dos Cardos, Florianópolis, Brasil, durante as temporadas reprodutivas de 2003, 2005 e 2006. A formação da colônia ocorreu em maio de 2003 e inicio de abril nos outros anos, com um total de ninhos variando entre 1.852 em 2006 a 2.486 em 2005. O sucesso de incubação foi estimado em 76,39% (2006, 62,73% (2003 e 41,1% em 2005, sendo que os menores valores puderam ser atribuídos a predação dos gaviões Caracara plancus, lagartos Tupinambis merianae e urubus Coragyps atratus. As primeiras eclosões foram

  3. Modeling the South American regional smoke plume: aerosol optical depth variability and surface shortwave flux perturbation

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    N. E. Rosário

    2013-03-01

    Full Text Available Intra-seasonal variability of smoke aerosol optical depth (AOD and downwelling solar irradiance at the surface during the 2002 biomass burning season in South America was modeled using the Coupled Chemistry-Aerosol-Tracers Transport model with the Brazilian developments on the Regional Atmospheric Modeling System (CCATT-BRAMS. Measurements of total and fine mode fraction (FMF AOD from the AErosol RObotic NETwork (AERONET and solar irradiance at the surface from the Solar Radiation Network (SolRad-NET were used to evaluate model results. In general, the major features associated with AOD evolution over the southern part of the Amazon basin and cerrado ecosystem are captured by the model. The main discrepancies were found for high aerosol loading events. In the northeastern portion of the Amazon basin the model systematically underestimated total AOD, as expected, since smoke contribution is not dominant as it is in the southern portion and emissions other than smoke were not considered in the simulation. Better agreement was obtained comparing the model results with observed FMF AOD, which pointed out the relevance of coarse mode aerosol emission in that region. Likewise, major discrepancies over cerrado during high AOD events were found to be associated with coarse mode aerosol omission in our model. The issue of high aerosol loading events in the southern part of the Amazon was related to difficulties in predicting the smoke AOD field, which was discussed in the context of emissions shortcomings. The Cuiabá cerrado site was the only one where the highest quality AERONET data were unavailable for both total and FMF AOD. Thus, lower quality data were used. Root-mean-square error (RMSE between the model and observed FMF AOD decreased from 0.34 to 0.19 when extreme AOD events (FMF AOD550 nm ≥ 1.0 and Cuiabá were excluded from the analysis. Downward surface solar irradiance comparisons also followed similar trends when extreme AOD were excluded

  4. The Dual Role a Buddhist Monk Played in the American South: The Balance between Heritage and Citizenship in the Refugee Community

    Directory of Open Access Journals (Sweden)

    Daniel Rhodes

    2016-05-01

    Full Text Available Buddhist Monks in Vietnam struggle with cultural preservation differently from a monk in the U.S. where the forces of acculturation for new arrivals, often refugees, are extraordinarily overwhelming. The author provides a case study examining how Buddhist leaders engage in cultural preservation and community building in the American South. Fusing ideas of Engaged Buddhism and community building, the author will demonstrate how a Buddhist monk is able to navigate the broader American culture and assist Vietnamese immigrants and refugees to acculturate, while maintaining their own cultural heritage, beliefs and religious traditions; ultimately building a viable and sustainable Buddhist community that contributes greatly to its new host community.

  5. Capitalising on North American speech resources for the development of a South African English large vocabulary speech recognition system

    CSIR Research Space (South Africa)

    Kamper, H

    2014-11-01

    Full Text Available -West University, Vanderbijlpark, South Africa 2Human Language Technologies Research Group, Meraka Institute, CSIR, Pretoria, South Africa {etienne.barnard, marelie.davel, cvheerden}@gmail.com, {fdwet, jbadenhorst}@csir.co.za Abstract The NCHLT speech...

  6. Clonal evolution through loss of chromosomes and subsequent polyploidization in chondrosarcoma.

    Directory of Open Access Journals (Sweden)

    Linda Olsson

    Full Text Available Near-haploid chromosome numbers have been found in less than 1% of cytogenetically reported tumors, but seem to be more common in certain neoplasms including the malignant cartilage-producing tumor chondrosarcoma. By a literature survey of published karyotypes from chondrosarcomas we could confirm that loss of chromosomes resulting in hyperhaploid-hypodiploid cells is common and that these cells may polyploidize. Sixteen chondrosarcomas were investigated by single nucleotide polymorphism (SNP array and the majority displayed SNP patterns indicative of a hyperhaploid-hypodiploid origin, with or without subsequent polyploidization. Except for chromosomes 5, 7, 19, 20 and 21, autosomal loss of heterozygosity was commonly found, resulting from chromosome loss and subsequent duplication of monosomic chromosomes giving rise to uniparental disomy. Additional gains, losses and rearrangements of genetic material, and even repeated rounds of polyploidization, may affect chondrosarcoma cells resulting in highly complex karyotypes. Loss of chromosomes and subsequent polyploidization was not restricted to a particular chondrosarcoma subtype and, although commonly found in chondrosarcoma, binucleated cells did not seem to be involved in these events.

  7. The Role of Polyploidization and Interspecific Hybridization in the Breeding of Ornamental Crops

    NARCIS (Netherlands)

    Marasek-Ciolakowska, A.; Arens, P.F.P.; Tuyl, van J.M.

    2016-01-01

    Polyploidy and hybridisation are critical processes in plant evolution and speciation. Many current agricultural crops are either natural or agricultural hybrids or polyploids, including potato, sugarcane, wheat, strawberries, and banana. There is a great deal of potential to utilise these natural

  8. Polyploidization mechanisms: temperature environment can induce diploid gamete formation in Rosa sp.

    Science.gov (United States)

    Pécrix, Yann; Rallo, Géraldine; Folzer, Hélène; Cigna, Mireille; Gudin, Serge; Le Bris, Manuel

    2011-06-01

    Polyploidy is an important evolutionary phenomenon but the mechanisms by which polyploidy arises still remain underexplored. There may be an environmental component to polyploidization. This study aimed to clarify how temperature may promote diploid gamete formation considered an essential element for sexual polyploidization. First of all, a detailed cytological analysis of microsporogenesis and microgametogenesis was performed to target precisely the key developmental stages which are the most sensitive to temperature. Then, heat-induced modifications in sporad and pollen characteristics were analysed through an exposition of high temperature gradient. Rosa plants are sensitive to high temperatures with a developmental sensitivity window limited to meiosis. Moreover, the range of efficient temperatures is actually narrow. 36 °C at early meiosis led to a decrease in pollen viability, pollen ectexine defects but especially the appearance of numerous diploid pollen grains. They resulted from dyads or triads mainly formed following heat-induced spindle misorientations in telophase II. A high temperature environment has the potential to increase gamete ploidy level. The high frequencies of diplogametes obtained at some extreme temperatures support the hypothesis that polyploidization events could have occurred in adverse conditions and suggest polyploidization facilitating in a global change context.

  9. Frequency of polyploid cells in the bone marrow of rats fed irradiated wheat

    International Nuclear Information System (INIS)

    George, K.P.; Chaubey, R.C.; Sundaram, K.; Gopal-Ayengar, A.R.

    1976-01-01

    Diets containing different proportions of non-irradiated or irradiated wheat were fed to Wistar rats for 1 or 6 wk. Cytological analysis of the bone marrow showed no significant difference in the frequency of polyploid cells in the rats fed non-irradiated or irradiated wheat diets, even when the treated wheat was fed to the rats within 24 hr of irradiation. (author)

  10. Clonal evolution through loss of chromosomes and subsequent polyploidization in chondrosarcoma.

    Science.gov (United States)

    Olsson, Linda; Paulsson, Kajsa; Bovée, Judith V M G; Nord, Karolin H

    2011-01-01

    Near-haploid chromosome numbers have been found in less than 1% of cytogenetically reported tumors, but seem to be more common in certain neoplasms including the malignant cartilage-producing tumor chondrosarcoma. By a literature survey of published karyotypes from chondrosarcomas we could confirm that loss of chromosomes resulting in hyperhaploid-hypodiploid cells is common and that these cells may polyploidize. Sixteen chondrosarcomas were investigated by single nucleotide polymorphism (SNP) array and the majority displayed SNP patterns indicative of a hyperhaploid-hypodiploid origin, with or without subsequent polyploidization. Except for chromosomes 5, 7, 19, 20 and 21, autosomal loss of heterozygosity was commonly found, resulting from chromosome loss and subsequent duplication of monosomic chromosomes giving rise to uniparental disomy. Additional gains, losses and rearrangements of genetic material, and even repeated rounds of polyploidization, may affect chondrosarcoma cells resulting in highly complex karyotypes. Loss of chromosomes and subsequent polyploidization was not restricted to a particular chondrosarcoma subtype and, although commonly found in chondrosarcoma, binucleated cells did not seem to be involved in these events.

  11. Tempo and mode of recurrent polyploidization in the Carassius auratus species complex (Cypriniformes, Cyprinidae).

    Science.gov (United States)

    Luo, J; Gao, Y; Ma, W; Bi, X-y; Wang, S-y; Wang, J; Wang, Y-q; Chai, J; Du, R; Wu, S-f; Meyer, A; Zan, R-g; Xiao, H; Murphy, R W; Zhang, Y-p

    2014-04-01

    Polyploidization is an evolutionarily rare but important mechanism in both plants and animals because it increases genetic diversity. Goldfish of the Carassius auratus species complex can be tetraploids, hexaploids and octaploids. Polyploidization events have occurred repeatedly in goldfish, yet the extent of this phenomenon and its phyletic history are poorly understood. We explore the origin, tempo and frequency of polyploidization in Chinese and Japanese goldfish using both mitochondrial (mtDNA) and nuclear DNA sequences from up to 1202 individuals including the outgroup taxon, Cyprinus carpio. Analyses of de novo nuclear gene data resolve two clusters of alleles and the pattern supports the prior hypothesis of an ancient allotetraploidization for Carassius. Alleles shared by tetraploid and hexaploid individuals indicate recent autoploidizations within the C. auratus complex. Sympatric tetraploids and hexaploids share mtDNA haplotypes and these frequently occur independently within six well-supported lineages and sublineages on a small spatial scale. Gene flow estimates (Fst values) indicate that hexaploids differ only slightly from sympatric tetraploids, if at all. In contrast, allopatric populations of tetraploids and hexaploids differ from one another to a far greater extent. Gene flow between sampled localities appears to be limited. Coalescence-based time estimations for hexaploids reveal that the oldest lineage within any sampled locality is around one million years old, which is very young. Sympatric, recurrent autoploidization occurs in all sampled populations of the C. auratus complex. Goldfish experience polyploidization events more frequently than any other vertebrate.

  12. Repeated polyploidization of Gossypium genomes and the evolution of spinnable cotton fibres

    Science.gov (United States)

    Emergent phenotypes are common in polyploids relative to their diploid progenitors, a phenomenon exemplified by spinnable cotton fibers. Following 15-18 fold paleopolyploidy, allopolyploidy 1-2 million years ago reunited divergent Gossypium genomes, imparting new combinatorial complexity that might ...

  13. Experimental Evolution Reveals Interplay between Sch9 and Polyploid Stability in Yeast.

    Directory of Open Access Journals (Sweden)

    Yi-Jin Lu

    2016-11-01

    Full Text Available Polyploidization has crucial impacts on the evolution of different eukaryotic lineages including fungi, plants and animals. Recent genome data suggest that, for many polyploidization events, all duplicated chromosomes are maintained and genome reorganizations occur much later during evolution. However, newly-formed polyploid genomes are intrinsically unstable and often quickly degenerate into aneuploidy or diploidy. The transition between these two states remains enigmatic. In this study, laboratory evolution experiments were conducted to investigate this phenomenon. We show that robust tetraploidy is achieved in evolved yeast cells by increasing the abundance of Sch9-a protein kinase activated by the TORC1 (Target of Rapamycin Complex 1 and other signaling pathways. Overexpressing SCH9, but not TOR1, allows newly-formed tetraploids to exhibit evolved phenotypes and knocking out SCH9 diminishes the evolved phenotypes. Furthermore, when cells were challenged with conditions causing ancestral cells to evolve aneuploidy, tetraploidy was maintained in the evolved lines. Our results reveal a determinant role for Sch9 during the early stage of polyploid evolution.

  14. Synthetic polyploids of Tragopogon miscellus and T. mirus (Asteraceae): 60 Years after Ownbey's discovery.

    Science.gov (United States)

    Tate, Jennifer A; Symonds, V Vaughan; Doust, Andrew N; Buggs, Richard J A; Mavrodiev, Evgeny; Majure, Lucas C; Soltis, Pamela S; Soltis, Douglas E

    2009-05-01

    In plants, polyploidy has been a significant evolutionary force on both recent and ancient time scales. In 1950, Ownbey reported two newly formed Tragopogon allopolyploids in the northwestern United States. We have made the first synthetic lines of T. mirus and T. miscellus using T. dubius, T. porrifolius, and T. pratensis as parents and colchicine treatment of F(1) hybrids. We also produced allotetraploids between T. porrifolius and T. pratensis, which are not known from nature. We report on the crossability between the diploids, as well as the inflorescence morphology, pollen size, meiotic behavior, and fertility of the synthetic polyploids. Morphologically, the synthetics resemble the natural polyploids with short- and long-liguled forms of T. miscellus resulting when T. pratensis and T. dubius are reciprocally crossed. Synthetic T. mirus was also formed reciprocally, but without any obvious morphological differences resulting from the direction of the cross. Of the 27 original crosses that yielded 171 hybrid individuals, 18 of these lineages have persisted to produce 386 S(1) progeny; each of these lineages has produced S(2) seed that are viable. The successful generation of these synthetic polyploids offers the opportunity for detailed comparative studies of natural and synthetic polyploids within a nonmodel system.

  15. The South American fruit fly, Anastrepha fraterculus (Wied.); advances in artificial rearing, taxonomic status and biological studies. Proceedings of a workshop

    Energy Technology Data Exchange (ETDEWEB)

    1999-01-01

    One of the fruit flies of major concern, because of its economic and quarantine importance in the Americas, is the exotic Mediterranean fruit fly, Ceratitis capitata, which is established throughout the Central and South American countries, excluding Chile. Chile, Mexico and the USA have conducted multi-million dollar campaigns to prevent the establishment of this and other exotic fruit flies in their respective territories, in support of the development of important fruit production and export industries. Other important fruit fly species, which are native to the American continent, are those of the genus Anastrepha. In this group, of most economic importance are A. obliqua and A. ludens for Mexico and some Central American countries and A. fraterculus and A. obliqua for South America. In this publication, attention is focused on A. fraterculus, the South American fruit fly. This species, as it is presently recognized, occurs from Mexico to Argentina and is reported from approximately 80 host plants, including commercial fruits of economic importance, such as mango, citrus, guava, apple and coffee. As A. fraterculus if considered to be of high economic and quarantine importance in many countries in South America, it is justifiable to recommend and promote the implementation of activities to strengthen knowledge of the species and develop techniques for its control and/or eradication. The development of sterile insect technique (SIT) and other biological control methods are very encouraging alternatives, as can be seen from examples in Mexico and the USA, where these approaches are in use against A. ludens and A. obliqua Refs, figs, tabs

  16. The South American fruit fly, Anastrepha fraterculus (Wied.); advances in artificial rearing, taxonomic status and biological studies. Proceedings of a workshop

    International Nuclear Information System (INIS)

    1999-01-01

    One of the fruit flies of major concern, because of its economic and quarantine importance in the Americas, is the exotic Mediterranean fruit fly, Ceratitis capitata, which is established throughout the Central and South American countries, excluding Chile. Chile, Mexico and the USA have conducted multi-million dollar campaigns to prevent the establishment of this and other exotic fruit flies in their respective territories, in support of the development of important fruit production and export industries. Other important fruit fly species, which are native to the American continent, are those of the genus Anastrepha. In this group, of most economic importance are A. obliqua and A. ludens for Mexico and some Central American countries and A. fraterculus and A. obliqua for South America. In this publication, attention is focused on A. fraterculus, the South American fruit fly. This species, as it is presently recognized, occurs from Mexico to Argentina and is reported from approximately 80 host plants, including commercial fruits of economic importance, such as mango, citrus, guava, apple and coffee. As A. fraterculus if considered to be of high economic and quarantine importance in many countries in South America, it is justifiable to recommend and promote the implementation of activities to strengthen knowledge of the species and develop techniques for its control and/or eradication. The development of sterile insect technique (SIT) and other biological control methods are very encouraging alternatives, as can be seen from examples in Mexico and the USA, where these approaches are in use against A. ludens and A. obliqua

  17. Transient Activation of Apomixis in Sexual Neotriploids May Retain Genomically Altered States and Enhance Polyploid Establishment

    Directory of Open Access Journals (Sweden)

    Diego Hojsgaard

    2018-02-01

    Full Text Available Polyploid genomes evolve and follow a series of dynamic transfigurations along with adaptation and speciation. The initial formation of a new polyploid individual within a diploid population usually involves a triploid bridge, a two-step mechanism of cell fusions between ubiquitous (reduced and rare (unreduced gametes. The primary fusion event creates an intermediate triploid individual with unbalanced genome sets, a situation of genomic-shock characterized by gene expression dysregulation, high dosage sensitivity, disturbed cell divisions, and physiological and reproductive attributes drastically altered. This near-sterile neotriploid must produce (even eupolyploids through secondary fusion events to restore genome steadiness, meiotic balance, and fertility required for the demographic establishment of a nascent lineage. Natural conditions locate several difficulties to polyploid establishment, including the production of highly unbalanced and rarely unreduced (euploid gametes, frequency-dependent disadvantages (minority cytotype exclusion, severe fitness loss, and ecological competition with diploid parents. Persistence and adaptation of neopolyploids depend upon genetic and phenotypic novelty coupled to joint selective forces that preserve shock-induced genomic changes (subgenome homeolog partitioning and drive meiotic (reproductive stabilization and ecological diversification. Thus, polyploid establishment through the triploid bridge is a feasible but not ubiquitous process that requires a number of low-probability events and singular circumstances. Yet, frequencies of polyploids suggest that polyploid establishment is a pervasive process. To explain this disparity, and supported in experimental evidence, I propose that situations like hybridization and ploidy-state transitions associated to genomic shock and substantial developmental alterations can transiently activate apomixis as a mechanism to halt genomic instability and cancel factors

  18. Divergences in hydraulic architecture form an important basis for niche differentiation between diploid and polyploid Betula species in NE China.

    Science.gov (United States)

    Zhang, Wei-Wei; Song, Jia; Wang, Miao; Liu, Yan-Yan; Li, Na; Zhang, Yong-Jiang; Holbrook, N Michele; Hao, Guang-You

    2017-05-01

    Habitat differentiation between polyploid and diploid plants are frequently observed, with polyploids usually occupying more stressed environments. In woody plants, polyploidization can greatly affect wood characteristics but knowledge of its influences on xylem hydraulics is scarce. The four Betula species in NE China, representing two diploids and two polyploids with obvious habitat differentiation, provide an exceptional study system for investigating the impact of polyploidization on environmental adaptation of trees from the point view of xylem hydraulics. To test the hypothesis that changes in hydraulic architecture play an important role in determining their niche differentiation, we measured wood structural traits at both the tissue and pit levels and quantified xylem water transport efficiency and safety in these species. The two polyploids had significantly larger hydraulic weighted mean vessel diameters than the two diploids (45.1 and 45.5 vs 25.9 and 24.5 μm) although the polyploids are occupying more stressed environments. As indicated by more negative water potentials corresponding to 50% loss of stem hydraulic conductivities, the two polyploids exhibited significantly higher resistance to drought-induced embolism than the two diploids (-5.23 and -5.05 vs -3.86 and -3.13 MPa) despite their larger vessel diameters. This seeming discrepancy is reconciled by distinct characteristics favoring greater embolism resistance at the pit level in the two polyploid species. Our results showed clearly that the two polyploid species have remarkably different pit-level anatomical traits favoring greater hydraulic safety than their congeneric diploid species, which have likely contributed to the abundance of polyploid birches in more stressed habitats; however, less porous inter-conduit pits together with a reduced leaf to sapwood area may have compromised their competitiveness under more favorable conditions. Contrasts in hydraulic architecture between diploid and

  19. Phylogeny of Amazona barbadensis and the Yellow-headed Amazon complex (Aves: Psittacidae): a new look at South American parrot evolution.

    Science.gov (United States)

    Urantówka, Adam Dawid; Mackiewicz, Paweł; Strzała, Tomasz

    2014-01-01

    The Yellow-shouldered Amazon (Amazona barbadensis) is the sole parrot of the genus Amazona that inhabits only dry forests. Its population has been dropping; therefore it has been the topic of many studies and conservation efforts. However, the phylogenetic relationship of this species to potential relatives classified within the Yellow-Headed Amazon (YHA) complex are still not clear. Therefore, we used more extensive data sets, including the newly sequenced mitochondrial genome of A. barbadensis, to conduct phylogenetic analyses. Various combinations of genes and many phylogenetic approaches showed that A. barbadensis clustered significantly with A. ochrocephala ochrocephala from Colombia and Venezuela, which created the Northern South American (NSA) lineage, clearly separated from two other lineages within the YHA complex, the Central (CA) and South American (SA). Tree topology tests and exclusion of rapidly evolving sites provided support for a NSA+SA grouping. We propose an evolutionary scenario for the YHA complex and its colonization of the American mainland. The NSA lineage likely represents the most ancestral lineage, which derived from Lesser Antillean Amazons and colonized the northern coast of Venezuela about a million years ago. Then, Central America was colonized through the Isthmus of Panama, which led to the emergence of the CA lineage. The southward expansion to South America and the origin of the SA lineage happened almost simultaneously. However, more intensive or prolonged gene flow or migrations have led to much weaker geographic differentiation of genetic markers in the SA than in the CA lineage.

  20. Whole-genome characterization of Uruguayan strains of avian infectious bronchitis virus reveals extensive recombination between the two major South American lineages.

    Science.gov (United States)

    Marandino, Ana; Tomás, Gonzalo; Panzera, Yanina; Greif, Gonzalo; Parodi-Talice, Adriana; Hernández, Martín; Techera, Claudia; Hernández, Diego; Pérez, Ruben

    2017-10-01

    Infectious bronchitis virus (Gammacoronavirus, Coronaviridae) is a genetically variable RNA virus that causes one of the most persistent respiratory diseases in poultry. The virus is classified in genotypes and lineages with different epidemiological relevance. Two lineages of the GI genotype (11 and 16) have been widely circulating for decades in South America. GI-11 is an exclusive South American lineage while the GI-16 lineage is distributed in Asia, Europe and South America. Here, we obtained the whole genome of two Uruguayan strains of the GI-11 and GI-16 lineages using Illumina high-throughput sequencing. The strains here sequenced are the first obtained in South America for the infectious bronchitis virus and provide new insights into the origin, spreading and evolution of viral variants. The complete genome of the GI-11 and GI-16 strains have 27,621 and 27,638 nucleotides, respectively, and possess the same genomic organization. Phylogenetic incongruence analysis reveals that both strains have a mosaic genome that arose by recombination between Euro Asiatic strains of the GI-16 lineage and ancestral South American GI-11 viruses. The recombination occurred in South America and produced two viral variants that have retained the full-length S1 sequences of the parental lineages but are extremely similar in the rest of their genomes. These recombinant virus have been extraordinary successful, persisting in the continent for several years with a notorious wide geographic distribution. Our findings reveal a singular viral dynamics and emphasize the importance of complete genomic characterization to understand the emergence and evolutionary history of viral variants. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Sexual Polyploidization in Medicago sativa L.: Impact on the Phenotype, Gene Transcription, and Genome Methylation.

    Science.gov (United States)

    Rosellini, Daniele; Ferradini, Nicoletta; Allegrucci, Stefano; Capomaccio, Stefano; Zago, Elisa Debora; Leonetti, Paola; Balech, Bachir; Aversano, Riccardo; Carputo, Domenico; Reale, Lara; Veronesi, Fabio

    2016-04-07

    Polyploidization as the consequence of 2n gamete formation is a prominent mechanism in plant evolution. Studying its effects on the genome, and on genome expression, has both basic and applied interest. We crossed two diploid (2n = 2x = 16) Medicago sativa plants, a subsp. falcata seed parent, and a coerulea × falcata pollen parent that form a mixture of n and 2n eggs and pollen, respectively. Such a cross produced full-sib diploid and tetraploid (2n = 4x = 32) hybrids, the latter being the result of bilateral sexual polyploidization (BSP). These unique materials allowed us to investigate the effects of BSP, and to separate the effect of intraspecific hybridization from those of polyploidization by comparing 2x with 4x full sib progeny plants. Simple sequence repeat marker segregation demonstrated tetrasomic inheritance for all chromosomes but one, demonstrating that these neotetraploids are true autotetraploids. BSP brought about increased biomass, earlier flowering, higher seed set and weight, and larger leaves with larger cells. Microarray analyses with M. truncatula gene chips showed that several hundred genes, related to diverse metabolic functions, changed their expression level as a consequence of polyploidization. In addition, cytosine methylation increased in 2x, but not in 4x, hybrids. Our results indicate that sexual polyploidization induces significant transcriptional novelty, possibly mediated in part by DNA methylation, and phenotypic novelty that could underpin improved adaptation and reproductive success of tetraploid M. sativa with respect to its diploid progenitor. These polyploidy-induced changes may have promoted the adoption of tetraploid alfalfa in agriculture. Copyright © 2016 Rosellini et al.

  2. Sexual Polyploidization in Medicago sativa L.: Impact on the Phenotype, Gene Transcription, and Genome Methylation

    Directory of Open Access Journals (Sweden)

    Daniele Rosellini

    2016-04-01

    Full Text Available Polyploidization as the consequence of 2n gamete formation is a prominent mechanism in plant evolution. Studying its effects on the genome, and on genome expression, has both basic and applied interest. We crossed two diploid (2n = 2x = 16 Medicago sativa plants, a subsp. falcata seed parent, and a coerulea × falcata pollen parent that form a mixture of n and 2n eggs and pollen, respectively. Such a cross produced full-sib diploid and tetraploid (2n = 4x = 32 hybrids, the latter being the result of bilateral sexual polyploidization (BSP. These unique materials allowed us to investigate the effects of BSP, and to separate the effect of intraspecific hybridization from those of polyploidization by comparing 2x with 4x full sib progeny plants. Simple sequence repeat marker segregation demonstrated tetrasomic inheritance for all chromosomes but one, demonstrating that these neotetraploids are true autotetraploids. BSP brought about increased biomass, earlier flowering, higher seed set and weight, and larger leaves with larger cells. Microarray analyses with M. truncatula gene chips showed that several hundred genes, related to diverse metabolic functions, changed their expression level as a consequence of polyploidization. In addition, cytosine methylation increased in 2x, but not in 4x, hybrids. Our results indicate that sexual polyploidization induces significant transcriptional novelty, possibly mediated in part by DNA methylation, and phenotypic novelty that could underpin improved adaptation and reproductive success of tetraploid M. sativa with respect to its diploid progenitor. These polyploidy-induced changes may have promoted the adoption of tetraploid alfalfa in agriculture.

  3. Y-chromosome and mtDNA variation confirms independent domestications and directional hybridization in South American camelids.

    Science.gov (United States)

    Marín, J C; Romero, K; Rivera, R; Johnson, W E; González, B A

    2017-10-01

    Investigations of genetic diversity and domestication in South American camelids (SAC) have relied on autosomal microsatellite and maternally-inherited mitochondrial data. We present the first integrated analysis of domestic and wild SAC combining male and female sex-specific markers (male specific Y-chromosome and female-specific mtDNA sequence variation) to assess: (i) hypotheses about the origin of domestic camelids, (ii) directionality of introgression among domestic and/or wild taxa as evidence of hybridization and (iii) currently recognized subspecies patterns. Three male-specific Y-chromosome markers and control region sequences of mitochondrial DNA are studied here. Although no sequence variation was found in SRY and ZFY, there were seven variable sites in DBY generating five haplotypes on the Y-chromosome. The haplotype network showed clear separation between haplogroups of guanaco-llama and vicuña-alpaca, indicating two genetically distinct patrilineages with near absence of shared haplotypes between guanacos and vicuñas. Although we document some examples of directional hybridization, the patterns strongly support the hypothesis that llama (Lama glama) is derived from guanaco (Lama guanicoe) and the alpaca (Vicugna pacos) from vicuña (Vicugna vicugna). Within male guanacos we identified a haplogroup formed by three haplotypes with different geographical distributions, the northernmost of which (Peru and northern Chile) was also observed in llamas, supporting the commonly held hypothesis that llamas were domesticated from the northernmost populations of guanacos (L. g. cacilensis). Southern guanacos shared the other two haplotypes. A second haplogroup, consisting of two haplotypes, was mostly present in vicuñas and alpacas. However, Y-chromosome variation did not distinguish the two subspecies of vicuñas. © 2017 Stichting International Foundation for Animal Genetics.

  4. Reliability and Validity of a Questionnaire for Physical Activity Assessment in South American Children and Adolescents: The SAYCARE Study.

    Science.gov (United States)

    Nascimento-Ferreira, Marcus Vinícius; De Moraes, Augusto César Ferreira; Toazza-Oliveira, Paulo Vinícius; Forjaz, Claudia L M; Aristizabal, Juan Carlos; Santaliesra-Pasías, Alba M; Lepera, Candela; Nascimento-Junior, Walter Viana; Skapino, Estela; Delgado, Carlos Alberto; Moreno, Luis Alberto; Carvalho, Heráclito Barbosa

    2018-03-01

    The objective of this article is to test the reliability and validity of the new and innovative physical activity (PA) questionnaire. Subsamples from the South American Youth/Child Cardiovascular and Environment Study (SAYCARE) study were included to examine its reliability (children: n = 161; adolescents: n = 177) and validity (children: n = 82; adolescents: n = 60). The questionnaire consists of three dimensions of PA (leisure, active commuting, and school) performed during the last week. To assess its validity, the subjects wore accelerometers for at least 3 days and 8 h/d (at least one weekend day). The reliability was analyzed by correlation coefficients. In addition, Bland-Altman analysis and a multilevel regression were applied to estimate the measurement bias, limits of agreement, and influence of contextual variables. In children, the questionnaire showed consistent reliability (ρ = 0.56) and moderate validity (ρ = 0.46), and the contextual variable variance explained 43.0% with -22.9 min/d bias. In adolescents, the reliability was higher (ρ = 0.76) and the validity was almost excellent (ρ = 0.88), with 66.7% of the variance explained by city level with 16.0 min/d PA bias. The SAYCARE PA questionnaire shows acceptable (in children) to strong (in adolescents) reliability and strong validity in the measurement of PA in the pediatric population from low- to middle-income countries. © 2018 The Obesity Society.

  5. Morphology, chemistry and function of the postpharyngeal gland in the South American digger wasps Trachypus boharti and Trachypus elongatus.

    Directory of Open Access Journals (Sweden)

    Gudrun Herzner

    Full Text Available Microbes pose severe threats to animals as competitors or pathogens and strongly affect the evolution of life history traits like parental care. Females of the European beewolf Philanthus triangulum, a solitary digger wasp, provision their offspring with paralyzed honeybees and embalm them with the secretion from large postpharyngeal glands (PPG that contain mainly unsaturated hydrocarbons. This coating changes the physico-chemical properties of the prey surface, causes a reduction of water condensation and retards growth of mold fungi. Here we examined the closely related South American genus Trachypus, which shows a life-history similar to Philanthus. We investigated whether Trachypus spp. also possess PPGs and embalm larval provisions. Using histological methods and 3D reconstructions we show that Trachypus boharti and T. elongatus possess PPGs that are similar to P. triangulum but somewhat smaller. The ultrastructure of the gland epithelium suggests that the gland content is at least partly sequestered from the hemolymph. Chemical analyses using gas chromatography / mass spectrometry revealed that both the cuticle and PPGs of Trachypus contain mainly unsaturated long-chain hydrocarbons. The gland of T. boharti additionally contains long-chain ketones. The hydrocarbons from the PPG of T. elongatus occurred on prey bees excavated from nests in the field but not on conspecific control bees. While the embalming only slightly elevated the amount of hydrocarbons on prey bees, the proportion of unsaturated hydrocarbons, which is crucial for the antifungal effect, was significantly increased. The Trachypus species under study possess PPGs that are very similar to the PPG of P. triangulum with regard to morphology, ultrastructure and chemistry. Moreover, we provide clear evidence that T. elongatus females embalm their prey, presumably as a means of prey preservation. The observed differences among Trachypus and Philanthus in gland size and prey

  6. Sequence analysis of the 5′ third of glycoprotein C gene of South American bovine herpesviruses 1 and 5

    Energy Technology Data Exchange (ETDEWEB)

    Traesel, C.K.; Bernardes, L.M. [Setor de Virologia, Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Spilki, F.R. [Laboratório de Microbiologia Molecular, Universidade Feevale, Novo Hamburgo, RS (Brazil); Weiblen, R.; Flores, E.F. [Setor de Virologia, Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil)

    2015-03-06

    Bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5) share high genetic and antigenic similarities, but exhibit marked differences in tissue tropism and neurovirulence. The amino-terminal region of glycoprotein C (gC), which is markedly different in each of the viruses, is involved in virus binding to cellular receptors and in interactions with the immune system. This study investigated the genetic and antigenic differences of the 5′ region of the gC (5′ gC) gene (amino-terminal) of South American BoHV-1 (n=19) and BoHV-5 (n=25) isolates. Sequence alignments of 374 nucleotides (104 amino acids) revealed mean similarity levels of 97.3 and 94.2% among BoHV-1 gC (gC1), respectively, 96.8 and 95.6% among BoHV-5 gC (gC5), and 62 and 53.3% between gC1 and gC5. Differences included the absence of 40 amino acid residues (27 encompassing predicted linear epitopes) scattered throughout 5′ gC1 compared to 5′ gC5. Virus neutralizing assays testing BoHV-1 and BoHV-5 antisera against each isolate revealed a high degree of cross-neutralization between the viruses, yet some isolates were neutralized at very low titers by heterologous sera, and a few BoHV-5 isolates reacted weakly with either sera. The virus neutralization differences observed within the same viral species, and more pronounced between BoHV-1 and BoHV-5, likely reflect sequence differences in neutralizing epitopes. These results demonstrate that the 5′ gC region is well conserved within each viral species but is divergent between BoHV-1 and BoHV-5, likely contributing to their biological and antigenic differences.

  7. Chile's seismogenic coupling zones - geophysical and neotectonic observations from the South American subduction zone prior to the Maule 2010 earthquake

    Science.gov (United States)

    Oncken With Tipteq, Onno; Ipoc Research Groups

    2010-05-01

    supported from recent findings along the exhumed, fossil seismogenic coupling zone of the European Alps. The data provide additional evidence that the degree of interseismic locking is closely mirrored by subsequent megathrust failure as evidenced by the slip and aftershock pattern of the Maule 2010 earthquake. Neogene surface deformation in Chile has been complex exhibiting tectonically uplifting areas along the coast driven by interseismically active reverse faulting. In addition, we observe coseismically subsiding domains along other parts of the coast. Moreover, the coseismic and interseismic vertical displacement identified is not coincident with long-term vertical motion that probably is superseded by slow basal underplating or tectonic erosion occurring at the downdip parts of the seismogenic zone causing discontinuous uplift. Analogue and numerical modelling lend additional support to the kinematic patterns linking slip at the seismogenic coupling zone and upper plate response. Finally we note that the characteristic peninsulas along the South American margin constitute stable rupture boundaries/barriers and appear to have done so for a protracted time as evidenced by their long-term uplift history since at least the Late Pliocene that points to anomalous properties of the plate interface affecting the mode of strain accumulation and plate interface rupture.

  8. Evolution of naturally occurring 5'non-coding region variants of Hepatitis C virus in human populations of the South American region

    Directory of Open Access Journals (Sweden)

    García-Aguirre Laura

    2007-08-01

    Full Text Available Abstract Background Hepatitis C virus (HCV has been the subject of intense research and clinical investigation as its major role in human disease has emerged. Previous and recent studies have suggested a diversification of type 1 HCV in the South American region. The degree of genetic variation among HCV strains circulating in Bolivia and Colombia is currently unknown. In order to get insight into these matters, we performed a phylogenetic analysis of HCV 5' non-coding region (5'NCR sequences from strains isolated in Bolivia, Colombia and Uruguay, as well as available comparable sequences of HCV strains isolated in South America. Methods Phylogenetic tree analysis was performed using the neighbor-joining method under a matrix of genetic distances established under the Kimura-two parameter model. Signature pattern analysis, which identifies particular sites in nucleic acid alignments of variable sequences that are distinctly representative relative to a background set, was performed using the method of Korber & Myers, as implemented in the VESPA program. Prediction of RNA secondary structures was done by the method of Zuker & Turner, as implemented in the mfold program. Results Phylogenetic tree analysis of HCV strains isolated in the South American region revealed the presence of a distinct genetic lineage inside genotype 1. Signature pattern analysis revealed that the presence of this lineage is consistent with the presence of a sequence signature in the 5'NCR of HCV strains isolated in South America. Comparisons of these results with the ones found for Europe or North America revealed that this sequence signature is characteristic of the South American region. Conclusion Phylogentic analysis revealed the presence of a sequence signature in the 5'NCR of type 1 HCV strains isolated in South America. This signature is frequent enough in type 1 HCV populations circulating South America to be detected in a phylogenetic tree analysis as a distinct

  9. A new cryptic species of South American freshwater pufferfish of the genus Colomesus (Tetraodontidae, based on both morphology and DNA data.

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    Cesar R L Amaral

    Full Text Available The Tetraodontidae are an Acantomorpha fish family with circumglobal distribution composed of 189 species grouped in 19 genera, occurring in seas, estuaries, and rivers between the tropical and temperate regions. Of these, the genus Colomesus is confined to South America, with what have been up to now considered only two species. C. asellus is spread over the entire Amazon, Tocantins-Araguaia drainages, and coastal environments from the Amazon mouth to Venezuela, and is the only freshwater puffers on that continent. C. psittacus is found in coastal marine and brackish water environments from Cuba to the northern coast of South America as far south as to Sergipe in Brazil. In the present contribution we used morphological data along with molecular systematics techniques to investigate the phylogeny and phylogeography of the freshwater pufferfishes of the genus Colomesus. The molecular part is based on a cytochrome C oxidase subunit I dataset constructed from both previously published and newly determined sequences, obtained from specimens collected from three distinct localities in South America. Our results from both molecular and morphological approaches enable us to identify and describe a new Colomesus species from the Tocantins River. We also discuss aspects of the historical biogeography and phylogeography of the South American freshwater pufferfishes, suggesting that it could be more recent than previously expected.

  10. A next-generation sequencing method for overcoming the multiple gene copy problem in polyploid phylogenetics, applied to Poa grasses

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    Robin Charles

    2011-03-01

    Full Text Available Abstract Background Polyploidy is important from a phylogenetic perspective because of its immense past impact on evolution and its potential future impact on diversification, survival and adaptation, especially in plants. Molecular population genetics studies of polyploid organisms have been difficult because of problems in sequencing multiple-copy nuclear genes using Sanger sequencing. This paper describes a method for sequencing a barcoded mixture of targeted gene regions using next-generation sequencing methods to overcome these problems. Results Using 64 3-bp barcodes, we successfully sequenced three chloroplast and two nuclear gene regions (each of which contained two gene copies with up to two alleles per individual in a total of 60 individuals across 11 species of Australian Poa grasses. This method had high replicability, a low sequencing error rate (after appropriate quality control and a low rate of missing data. Eighty-eight percent of the 320 gene/individual combinations produced sequence reads, and >80% of individuals produced sufficient reads to detect all four possible nuclear alleles of the homeologous nuclear loci with 95% probability. We applied this method to a group of sympatric Australian alpine Poa species, which we discovered to share an allopolyploid ancestor with a group of American Poa species. All markers revealed extensive allele sharing among the Australian species and so we recommend that the current taxonomy be re-examined. We also detected hypermutation in the trnH-psbA marker, suggesting it should not be used as a land plant barcode region. Some markers indicated differentiation between Tasmanian and mainland samples. Significant positive spatial genetic structure was detected at Conclusions Our results demonstrate that 454 sequencing of barcoded amplicon mixtures can be used to reliably sample all alleles of homeologous loci in polyploid species and successfully investigate phylogenetic relationships among

  11. Sibling Rivalry in Myxococcus xanthus Is Mediated by Kin Recognition and a Polyploid Prophage.

    Science.gov (United States)

    Dey, Arup; Vassallo, Christopher N; Conklin, Austin C; Pathak, Darshankumar T; Troselj, Vera; Wall, Daniel

    2016-01-19

    Myxobacteria form complex social communities that elicit multicellular behaviors. One such behavior is kin recognition, in which cells identify siblings via their polymorphic TraA cell surface receptor, to transiently fuse outer membranes and exchange their contents. In addition, outer membrane exchange (OME) regulates behaviors, such as inhibition of wild-type Myxococcus xanthus (DK1622) from swarming. Here we monitored the fate of motile cells and surprisingly found they were killed by nonmotile siblings. The kill phenotype required OME (i.e., was TraA dependent). The genetic basis of killing was traced to ancestral strains used to construct DK1622. Specifically, the kill phenotype mapped to a large "polyploid prophage," Mx alpha. Sensitive strains contained a 200-kb deletion that removed two of three Mx alpha units. To explain these results, we suggest that Mx alpha expresses a toxin-antitoxin cassette that uses the OME machinery of M. xanthus to transfer a toxin that makes the population "addicted" to Mx alpha. Thus, siblings that lost Mx alpha units (no immunity) are killed by cells that harbor the element. To test this, an Mx alpha-harboring laboratory strain was engineered (by traA allele swap) to recognize a closely related species, Myxococcus fulvus. As a result, M. fulvus, which lacks Mx alpha, was killed. These TraA-mediated antagonisms provide an explanation for how kin recognition specificity might have evolved in myxobacteria. That is, recognition specificity is determined by polymorphisms in traA, which we hypothesize were selected for because OME with non-kin leads to lethal outcomes. The transition from single cell to multicellular life is considered a major evolutionary event. Myxobacteria have successfully made this transition. For example, in response to starvation, individual cells aggregate into multicellular fruiting bodies wherein cells differentiate into spores. To build fruits, cells need to recognize their siblings, and in part, this is

  12. Spatial Epidemiology of Alcohol- and Drug-Related Health Problems Among Northern Plains American Indians: Nebraska and South Dakota, 2007 to 2012.

    Science.gov (United States)

    Ponicki, William R; Henderson, Jeffrey A; Gaidus, Andrew; Gruenewald, Paul J; Lee, Juliet P; Moore, Roland S; Davids, Sharice; Tilsen, Nick

    2018-03-01

    Despite high abstinence rates, American Indians experience elevated rates of many alcohol and other drug problems. American Indians also predominantly reside in poor and rural areas, which may explain some observed health disparities. We investigated whether geographic areas including reservations or large American Indian populations exhibited greater incidence of alcohol- and drug-related hospitalizations. We obtained inpatient hospitalization records for 2 Northern Plain states (Nebraska and South Dakota) for the years 2007 to 2012. We constructed zip code counts for 10 categories of hospitalization with diagnoses or injury causation commonly associated with alcohol or drug use. We related these to community sociodemographic characteristics using Bayesian Poisson space-time regression models and examined associations with and without controls for whether each zip code was located within an American Indian reservation. Controlling for other demographic and economic characteristics, zip codes with greater percentage of American Indians exhibited greater incidence for all 10 substance abuse-related health outcomes (9 of 10 well supported); zip code areas within American Indian reservations had greater incidence of self-inflicted injury and drug dependence and abuse, and reduced incidence of alcohol cirrhosis and prescription opioid poisoning. However, the analyses generally demonstrated no well-supported differences in incidence associated with local residence percentages of American Indian versus African American. In our analyses, ethnicity or heredity alone did not account for alcohol- and drug-related hospitalizations among Native populations. Aspects of social, economic, and political dimensions of Native lives must be considered in the etiology of alcohol- and drug-related problems for rural-dwelling indigenous peoples. Copyright © 2018 by the Research Society on Alcoholism.

  13. Ecological niche differentiation of polyploidization is not supported by environmental differences among species in a cosmopolitan grass genus.

    Science.gov (United States)

    Visser, Vernon; Molofsky, Jane

    2015-01-01

    Polyploidization frequently results in the creation of new plant species, the establishment of which is thought to often be facilitated by ecological niche differentiation from the diploid species. We tested this hypothesis using the cosmopolitan grass genus Phalaris (Poaceae), consisting of 19 species that range from diploid to tetraploid to hexaploid. Specifically, we tested whether (1) polyploids occupy more extreme environments and/or (2) have broader niche breadths and/or (3) whether the polyploid species' distributions indicate a niche shift from diploid species.• We employed a bootstrapping approach using distribution data for each species and eight environmental variables to investigate differences between species in the means, extremes, and breadths of each environmental variable. We used a kernel smoothing technique to quantify niche overlap between species.• Although we found some support for the three hypotheses for a few diploid-polyploid pairs and for specific environmental variables, none of these hypotheses were generally supported.• Our results suggest that these commonly held hypotheses about the effects of polyploidization on ecological distributions are not universally applicable. Correlative biogeographic studies like ours provide a necessary first step for suggesting specific hypotheses that require experimental verification. A combination of genetic, physiological, and ecological studies will be required to achieve a better understanding of the role of polyploidization in niche evolution. © 2015 Botanical Society of America, Inc.

  14. The Maule, 2010, earthquake - geophysical and kinematic observations of the South American margin prior to the earthquake (Invited)

    Science.gov (United States)

    Oncken, O.; Haberland, C. A.; Moreno, M.; Melnick, D.; Tilmann, F.; Tipteq Research Groups

    2010-12-01

    distribution as evidenced by the recent Maule earthquake. Moreover, the latter coseismic rupture pattern was foreseeable from its pre-seismic locking pattern as derived by inversion of GPS observations during the previous decade. Neogene surface deformation at the Chilean coast related to these locking properties has been complex exhibiting tectonically uplifting areas along the coast driven by interseismically active reverse faulting. In addition, we observe coseismically subsiding domains along other parts of the coast - mostly above fully locked patches. Finally, we note that the characteristic peninsulas along the South American margin constitute stable rupture boundaries and appear to have done so for a protracted time as evidenced by their long-term uplift history since at least the Late Pliocene. This suggests barriers to rupture being related to anomalous properties of the plate interface affecting the mode of strain accumulation and plate interface rupture - like e.g. velocity strengthening in contrast to the weakening property of most of the remaining domains.

  15. Gomphrena claussenii, the first South American metallophyte species with indicator-like Zn and Cd accumulation and extreme metal tolerance

    Directory of Open Access Journals (Sweden)

    Mina eT. Villafort Carvalho

    2013-06-01

    Full Text Available Plant species with the capacity to tolerate heavy metals are potentially useful for phytoremediation since they have adapted to survive and reproduce under toxic conditions and to accumulate high metal concentrations. Gomphrena claussenii Moq., a South-American species belonging to the Amaranthaceae, is found at a zinc (Zn mining area in the state of Minas Gerais, Brazil. Through soil and hydroponic experiments, the metal tolerance and accumulation capacities of G. claussenii were assessed and the effects on physiological characteristics were compared with a closely-related non-tolerant species, Gomphrena elegans Mart. Gomphrena. claussenii plants grown in soil sampled at the Zn smelting area accumulated up to 5318 µg g-1 of Zn and 287 µg g-1 of Cd in shoot dry biomass after 30 days of exposure. Plants were grown in hydroponics containing up to 3000 µM of Zn and 100 µM of Cd for G. claussenii and 100 µM of Zn and 5 µM of Cd for G. elegans. Gomphrena claussenii proved to be an extremely tolerant species to both Zn and Cd, showing only slight metal toxicity symptoms at the highest treatment levels, without significant decrease in biomass and no effects on root growth, whereas the non-tolerant species G. elegans showed significant toxicity effects at the highest exposure levels. Both species accumulated more Zn and Cd in roots than in shoots. In G. elegans over 90% of the Cd remained in the roots, but G. claussenii showed a root:shoot concentration ratio of around 2, with shoots reaching 0.93 % Zn and 0.13 % Cd on dry matter base. In G. claussenii shoots, the concentrations of other minerals, such as Fe and Mn, were only affected by the highest Zn treatment while in G. elegans the Fe and Mn concentrations in shoots decreased drastically at both Zn and Cd treatments. Taking together, these results indicate that G. claussenii is a novel metallophyte, extremely tolerant of high Zn and Cd exposure and an interesting species for further

  16. Acute effects of temperature and hypercarbia on cutaneous and branchial gas exchange in the South American lungfish, Lepidosiren paradoxa.

    Science.gov (United States)

    Zena, Lucas A; Bícego, Kênia C; da Silva, Glauber S F; Giusti, Humberto; Glass, Mogens L; Sanchez, Adriana P

    2017-01-01

    The South American lungfish, Lepidosiren paradoxa inhabits seasonal environments in the Central Amazon and Paraná-Paraguay basins that undergo significant oscillations in temperature throughout the year. They rely on different gas exchange organs, such as gills and skin for aquatic gas exchange while their truly bilateral lungs are responsible for aerial gas exchange; however, there are no data available on the individual contributions of the skin and the gills to total aquatic gas exchange in L. paradoxa. Thus, in the present study we quantify the relative contributions of skin and gills on total aquatic gas exchange during warm (35°C) and cold exposure (20°C) in addition to the effects of aerial and aquatic hypercarbia on aquatic gas exchange and gill ventilation rate (f G ; 25°C), respectively. Elevated temperature (35°C) caused a significant increase in the contribution of cutaneous (from 0.61±0.13 to 1.34±0.26ml. STPD.h -1 kg -1 ) and branchial (from 0.54±0.17 to 1.73±0.53ml. STPD.h -1 kg -1 ) gas exchange for V̇CO 2 relative to the lower temperature (20°C), while V̇O 2 remained relatively unchanged. L. paradoxa exhibited a greater branchial contribution in relation to total aquatic gas exchange at lower temperatures (20 and 25°C) for oxygen uptake. Aerial hypercarbia decreased branchial V̇O 2 whereas branchial V̇CO 2 was significantly increased. Progressive increases in aquatic hypercarbia did not affect f G . This response is in contrast to increases in pulmonary ventilation that may offset any increase in arterial partial pressure of CO 2 owing to CO 2 loading through the animals' branchial surface. Thus, despite their reduced contribution to total gas exchange, cutaneous and branchial gas exchange in L. paradoxa can be significantly affected by temperature and aerial hypercarbia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Effects of gamma radiation on the ovarian development of the south american fruit fly, Anastrepha fraterculus (Wiedemann, 1830)

    International Nuclear Information System (INIS)

    Mastrangelo, Thiago; Botteon, Victor; Scopel, Wanessa

    2017-01-01

    The South American fruit fly, Anastrepha fraterculus (Wied.) represents 98.5% of the flies captured in commercial apple orchards from Brazil. Looking for environmentally friendly alternatives to suppress this fruit fly pest, researchers from USP and EMBRAPA, along with the Brazilian Association of Apple Producers, created the MOSCASUL Biological Control Center, which intends to apply an Area-Wide Integrated Pest Management Program that integrates the Sterile Insect Technique (SIT). The assurance of sterility of the released flies is a critical assumption of an SIT program, since the unintentional release of thousands of fertile females could cause severe damages to the orchards nearby. Females of A. fraterculus are more radiosensitive than males, but the morphology of the ovaries of the sterile females was not investigated so far. The objective of this study, therefore, was to characterize the morphology of the ovaries of A. fraterculus treated with different doses of gamma radiation. Pupae with 48 h before adult emergence were irradiated with 0 (control), 15, 25, 35, and 45 Gy at the Gammabeam-650® irradiator from CENA/USP. Twelve hours after initial emergence, adults were sorted by sex, and for each radiation dose, 1 day old nonirradiated males were placed with irradiated females of the same age in cages. Adult females were then dissected in a saline solution at 1, 7, and 15 days of age, and the ovaries were examined under stereo microscope. The length, width and area of each ovary were measured from the images made. On the 1 st day after the emergence of the adults, no morphological differences were observed among irradiated and nonirradiated ovaries. On the 7 th day, however, the nonirradiated ovaries showed to be larger than the irradiated ones. Doses of 15 Gy or higher induced complete atrophy of the ovaries and, on the 15 th day, no signs of regeneration of the ovaries were observed. On the last day of observation, the irradiated ovaries presented mean area

  18. Effects of gamma radiation on the ovarian development of the south american fruit fly, Anastrepha fraterculus (Wiedemann, 1830)

    Energy Technology Data Exchange (ETDEWEB)

    Mastrangelo, Thiago; Botteon, Victor, E-mail: piaui@cena.usp.br, E-mail: victor.botteon@usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Scopel, Wanessa, E-mail: scopelw@usp.br [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil)

    2017-07-01

    The South American fruit fly, Anastrepha fraterculus (Wied.) represents 98.5% of the flies captured in commercial apple orchards from Brazil. Looking for environmentally friendly alternatives to suppress this fruit fly pest, researchers from USP and EMBRAPA, along with the Brazilian Association of Apple Producers, created the MOSCASUL Biological Control Center, which intends to apply an Area-Wide Integrated Pest Management Program that integrates the Sterile Insect Technique (SIT). The assurance of sterility of the released flies is a critical assumption of an SIT program, since the unintentional release of thousands of fertile females could cause severe damages to the orchards nearby. Females of A. fraterculus are more radiosensitive than males, but the morphology of the ovaries of the sterile females was not investigated so far. The objective of this study, therefore, was to characterize the morphology of the ovaries of A. fraterculus treated with different doses of gamma radiation. Pupae with 48 h before adult emergence were irradiated with 0 (control), 15, 25, 35, and 45 Gy at the Gammabeam-650® irradiator from CENA/USP. Twelve hours after initial emergence, adults were sorted by sex, and for each radiation dose, 1 day old nonirradiated males were placed with irradiated females of the same age in cages. Adult females were then dissected in a saline solution at 1, 7, and 15 days of age, and the ovaries were examined under stereo microscope. The length, width and area of each ovary were measured from the images made. On the 1{sup st} day after the emergence of the adults, no morphological differences were observed among irradiated and nonirradiated ovaries. On the 7{sup th} day, however, the nonirradiated ovaries showed to be larger than the irradiated ones. Doses of 15 Gy or higher induced complete atrophy of the ovaries and, on the 15{sup th} day, no signs of regeneration of the ovaries were observed. On the last day of observation, the irradiated ovaries

  19. Population Structure of mtDNA Variation due to Pleistocene Fluctuations in the South American Maned Wolf (Chrysocyon brachyurus, Illiger, 1815): Management Units for Conservation.

    Science.gov (United States)

    González, Susana; Cosse, Mariana; Franco, María del Rosario; Emmons, Louise; Vynne, Carly; Duarte, José Maurício Barbanti; Beccacesi, Marcelo D; Maldonado, Jesús E

    2015-01-01

    The maned wolf (Chrysocyon brachyurus) is one of the largest South American canids, and conservation across this charismatic carnivore's large range is presently hampered by a lack of knowledge about possible natural subdivisions which could influence the population's viability. To elucidate the phylogeographic patterns and demographic history of the species, we used 2 mtDNA markers (D-loop and cytochrome b) from 87 individuals collected throughout their range, in Argentina, Bolivia, Brazil, and Uruguay. We found moderate levels of haplotype and nucleotide diversity, and the 14 D-loop haplotypes were closely related. Genetic structure results revealed 4 groups, and when coupled with model inferences from a coalescent analysis, suggested that maned wolves have undergone demographic fluctuations due to changes in climate and habitat during the Pleistocene glaciation period approximately 24000 years before present (YBP). This genetic signature points to an event that occurred within the timing estimated for the start of the contraction of the Cerrado around 50000 YBP. Our results reveal a genetic signature of population size expansion followed by contraction during Pleistocene interglaciations, which had similar impacts on other South American mammals. The 4 groups should for now be considered management units, within which future monitoring efforts should be conducted independently. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Food Insecurity, Not Stress is Associated with Three Measures of Obesity in Low-Income, Mexican-American Women in South Texas.

    Science.gov (United States)

    Salinas, Jennifer J; Shropshire, William; Nino, Ana; Parra-Medina, Deborah

    2016-01-01

    To determine the relationship between obesity, food insecurity and perceived stress in very low income Mexican American women. Cross-sectional baseline data analysis of a randomized clinical trial. Texas-Mexico border region of South Texas. Very Low Income Mexican American Women. The relationship between obesity and food insecurity in a sample of very low income Hispanic women living in South Texas depends on the measure of obesity and the dimension of food insecurity. The only measure of food insecurity associated with all measures of obesity was often not having enough money to afford to eat balanced meals. Waist circumference was associated with the most dimensions of food insecurity, while BMI had the least associations. Finally, perceived stress was not significantly associated with BMI, waist circumference or percent body fat when adjusted for other covariates. We have found a strong and significant relationship between food insecurity related to having enough resources to eat a balanced diet and BMI, waist circumference, and percent body fat in low-income Mexican American women. While behavioural change is an important strategy for reducing obesity, consideration may need to be made as to how food access with high nutritional value, may be in and of itself a contributing factor in obesity in low income populations.

  1. Whole-body X-irradiation of mice accelerates polyploidization of hepatocytes

    International Nuclear Information System (INIS)

    Shima, A.; Egami, N.

    1985-01-01

    Male C57BL/6 mice were whole-body irradiated with 4.75 gy of X-rays at the age of 2 months and killed at 2, 6, 12 and 19 months after irradiation. The percentage survival began to decline earlier and faster in the irradiated group than the controls up to 19 months after exposure when the study was terminated. The nuclear DNA content of individual hepatocytes was measured by a Feulgen-DNA microfluorometric method, and hepatocytes were classified into various ploidy classes. In the irradiated mice, the degree of polyploidization was significantly higher than the controls by 2 months after exposure and steadily increased up to 6 months after exposure. Thereafter, however, a slow return to the control level was found up to 19 months after irradiation. These results appear to support a hypothesis that radiation accelerates the ageing process as judged from hepatocyte polyploidization. (author)

  2. The mistress, the midwife, and the medical doctor: pregnancy and childbirth on the plantations of the antebellum American South, 1800-1860.

    Science.gov (United States)

    Tunc, Tanfer Emin

    2010-01-01

    This article represents a step towards examining the relationship between three key figures in the antebellum American South: the plantation mistress, the slave-midwife, and the professional male physician. It elucidates how the experiences of pregnancy and childbirth, which brought women close to death, formed the basis of a deeper, positive relationship between the black and white women of the antebellum South, and assesses the ways in which the professionalization of medicine affected this reproductive bond. Evaluating such a complicated network of relationships necessitates dissecting numerous layers of social interaction, including black and white women's shared cultural experiences and solidarity as reproductive beings; the role, power, and significance of slave-midwives and other enslaved caretakers in white plantation births; the cooperation between pregnant bondswomen and plantation mistresses; and the impact that the burgeoning profession of medicine had on the procreative union between antebellum black and white women.

  3. TGFbeta Induces Binucleation/Polyploidization in Hepatocytes through a Src-Dependent Cytokinesis Failure.

    Directory of Open Access Journals (Sweden)

    Marco De Santis Puzzonia

    Full Text Available In all mammals, the adult liver shows binucleated as well as mononucleated polyploid hepatocytes. The hepatic polyploidization starts after birth with an extensive hepatocyte binucleation and generates hepatocytes of several ploidy classes. While the functional significance of hepatocyte polyploidy is becoming clearer, how it is triggered and maintained needs to be clarified. Aim of this study was to identify a major inducer of hepatocyte binucleation/polyploidization and the cellular and molecular mechanisms involved. We found that, among several cytokines analyzed, known to be involved in early liver development and/or mass control, TGFbeta1 was capable to induce, together with the expected morphological changes, binucleation in hepatocytes in culture. Most importantly, the pharmacological inhibition of TGFbeta signaling in healthy mice during weaning, when the physiological binucleation occurs, induced a significant decrease of hepatocyte binucleation rate, without affecting cell proliferation and hepatic index. The TGFbeta-induced hepatocyte binucleation resulted from a cytokinesis failure, as assessed by video microscopy, and is associated with a delocalization of the cytokinesis regulator RhoA-GTPase from the mid-body of dividing cells. The use of specific chemical inhibitors demonstrated that the observed events are Src-dependent. Finally, the restoration of a fully epithelial phenotype by TGFbeta withdrawal gave rise to a cell progeny capable to maintain the polyploid state. In conclusion, we identified TGFbeta as a major inducer of hepatocyte binucleation both in vitro and in vivo, thus ascribing a novel role to this pleiotropic cytokine. The production of binucleated/tetraploid hepatocytes is due to a cytokinesis failure controlled by the molecular axis TGFbeta/Src/RhoA.

  4. TGFbeta Induces Binucleation/Polyploidization in Hepatocytes through a Src-Dependent Cytokinesis Failure.

    Science.gov (United States)

    De Santis Puzzonia, Marco; Cozzolino, Angela Maria; Grassi, Germana; Bisceglia, Francesca; Strippoli, Raffaele; Guarguaglini, Giulia; Citarella, Franca; Sa