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Sample records for argentine hake merluccius

  1. Feeding strategy and cannibalism of the Argentine hake Merluccius hubbsi.

    PubMed

    Ocampo Reinaldo, M; González, R; Romero, M A

    2011-12-01

    The diet composition and feeding strategy of the Argentine hake Merluccius hubbsi in the San Matías Gulf were analysed in order to use this information for the sustainable management of the fishery. Merluccius hubbsi behaved as an opportunistic predator. Small M. hubbsi consumed planktonic crustaceans, whereas medium and large fish ate numerous prey taxa with low frequency of occurrence and variable specific abundance. Intra- and intercohort cannibalism were detected in all size groups and were particularly significant in large M. hubbsi. Medium-sized M. hubbsi consumed small conspecifics and large-sized M. hubbsi consumed both small and medium M. hubbsi. These results indicate that the removal of large M. hubbsi by fishing may increase the risk of overfishing by two combined effects: a direct effect of recruitment-overfishing and an indirect effect of growth-overfishing through an enhanced cannibalism of medium M. hubbsi on small M. hubbsi. Intra- and intercohort cannibalism and other trophic relationships in the M. hubbsi should therefore be considered explicitly in stock assessment models.

  2. Comparative study of spawning pattern and reproductive potential of the Northern and Southern stocks of Argentine hake (Merluccius hubbsi)

    NASA Astrophysics Data System (ADS)

    Rodrigues, Karina A.; Macchi, Gustavo J.; Militelli, Maria I.

    2015-08-01

    The reproductive biology of the Northern (Bonaerense) and Southern (Patagonian) stocks of Merluccius hubbsi in the Argentinean Sea is analyzed, including information on spawning areas, estimates of abundance and size composition of spawning females, fecundity, spawning frequency and egg quality. Samples of Argentine hake were obtained during the period of peak reproductive activity; May and January for the Northern and Southern stocks, respectively. The size of the reproductive area for the Northern stock (35-38°S) was clearly smaller than the one estimated for the Southern population (43°30‧-46°S), being 23,770 km2 and 52,460 km2 respectively. Spawning females from the Northern reproductive area were smaller (modal values between 35 and 40 cm TL) than those from the Southern stock (modal values between 38 and 50 cm TL), and they were also less abundant in number and had a lower spawning frequency (8-13 days and 5-7 days between partial spawning for the Northern and Southern stocks respectively). No differences in batch and relative fecundity between stocks were recorded (mean values of 526 and 530 hydrated oocytes g- 1), but the dry weights of hydrated oocytes from females of the Northern group were higher (3.08 mg for 100 hydrated oocytes) than those of the Patagonian stock (2.84 mg) for the same total length range. The egg production during the month of peak spawning of the Northern group depended mostly on the smaller females (< 50 cm TL) and was in average 1 to 2 orders of magnitude lower than that estimated for the Southern stock (9 × 1012-22 × 1012 eggs and 692 × 1012-1295 × 1012 eggs for the Northern and Southern stocks respectively). Those differences in egg production and the high productivity and retentive characteristics described for the spawning area and nursery ground in Patagonian waters would justify the greater abundance and resilience of the Southern stock of Argentine hake. The low abundance of females in spawning capable stage observed

  3. Myxozoans as biological tags for stock identification of the Argentine hake, Merluccius hubbsi (Gadiformes: Merlucciidae).

    PubMed

    Cantatore, D M P; Irigoitia, M M; Holzer, A S; Timi, J T

    2016-05-01

    Myxozoans have been successfully used as tags for fish stock identification around the world. However, few studies using myxozoan tags have been carried out in the Southern Atlantic, a region with complex oceanography that constitutes a potentially suitable scenario for testing the utility of myxozoans as indicators. Its usefulness was tested using six samples of Merluccius hubbsi in two different regions of the Argentine Sea. Generalized linear models were performed to assess the effects of fish size and sex, and year and region of capture and selected using the Information Theoretic approach. Three myxozoan species were recorded: Kudoa rosenbuschi, Myxoproteus meridionalis and Fabespora sp. Results of modelling species individually showed differential capabilities for detecting geographical population structure at different spatial scales, with K. rosenbuschi and Fabespora sp. allowing the discrimination of northern and southern stocks, but Fabespora sp. also as a promissory indicator of intrapopulation sub-structure due to different migratory routes during non-reproductive periods. This work confirms that myxozoans offer a set of suitable markers at different spatial scales, which can be selected individually or in any combination, depending on the geographical extent of the study, constituting tools adaptable to the objectives of further research on fish population structure.

  4. Spatial patterns of copepod biodiversity in relation to a tidal front system in the main spawning and nursery area of the Argentine hake Merluccius hubbsi

    NASA Astrophysics Data System (ADS)

    Temperoni, B.; Viñas, M. D.; Martos, P.; Marrari, M.

    2014-11-01

    Copepods play an important role in marine ecosystems as a direct link of energy transfer between primary producers and higher trophic level consumers, such as fish. In the Argentine Sea, the Patagonian stock of Argentine hake Merluccius hubbsi spawns from late austral spring (December) to early autumn (April) in the northern Patagonian shelf region (43°-45°30‧S), in association with a highly productive tidal front system. Since hake larvae prey mainly upon copepods, the objective of this study was to assess the spatial variability in the abundance and diversity of these potential food items in different sectors of the front, as one of the possible factors affecting hake recruitment success. Two complementary mesh sizes (67 and 300 μm) were used to accurately target the entire copepod size spectrum. The copepod community was dominated by developmental stages < 1 mm in total length (eggs, nauplii, copepodites of cyclopoids and calanoids), and adults of the species Oithona helgolandica, Microsetella norvegica, Ctenocalanus vanus and Drepanopus forcipatus. Their spatial distribution was highly influenced by the across-shelf characteristics of the tidal front system, highlighting the impact of environmental features, mainly bottom temperature and salinity, in shaping the community. Abundances were higher in the transitional relative to the stratified sector of the system. Such sector would provide the appropriate conditions to sustain M. hubbsi larval growth resulting from high availability of adequate prey, the suitable thermal ranges, and the existence of retention mechanisms.

  5. New tools (DNA barcoding), old hypothesis: the case of the taxonomic identity of the Argentine hakes (Actinopterygii: Merluccius).

    PubMed

    Deli Antoni, M Y; González-Castro, M; Díaz de Astarloa, J M

    2015-09-01

    The present study evaluated the possible occurrence of cryptic species among Merluccidae from Argentina by examining sequences of cytochrome c oxidase subunit I (coI) mtDNA. This approach can discriminate Merluccius hubbsi and Merluccius australis; specimens with morphological diagnostic characters of Merluccius patagonicus formed a cohesive cluster with M. hubbsi specimens. BIN analysis confirmed the effectiveness of barcoding within a global context.

  6. Fine spatial structure of Atlantic hake (Merluccius merluccius) stocks revealed by variation at microsatellite loci.

    PubMed

    Castillo, Ana G F; Martinez, Jose L; Garcia-Vazquez, Eva

    2004-01-01

    Genetic variation at 5 microsatellite loci was analyzed for European hake Merluccius merluccius sampled from 9 different regions in the Atlantic Ocean and the Mediterranean Sea. Significant genetic differentiation was found between samples, suggesting a fine subdivision of Atlantic and Mediterranean hake stocks. These results are discussed in the context of the decline of demersal fish species, probably due to overfishing.

  7. Identification of European Hake species (Merluccius merluccius) using real-time PCR.

    PubMed

    Sánchez, A; Quinteiro, J; Rey-Mendez, M; Perez-Martín, R I; Sotelo, C G

    2009-05-13

    A rapid and precise method for identifying European hake (Merluccius merluccius) based on TaqMan technology is presented. The method can be applied to fresh, frozen, and processed fish products to detect the fraudulent or unintentional mislabeling of this species. Specific primers and a minor groove binding (MGB) TaqMan probe were designed for this purpose based on partial sequences of the mitochondrial DNA control region. Combinations of primers and probe concentrations that gave the lowest Ct value and the highest final fluorescence value were selected to carry out efficiency, specificity, and cross-reactivity assays. The method was successfully tested on 31 commercial hake samples. A Ct value of about 16 was obtained when Merluccius merluccius was present; however, the fluorescence signal was not detected most of the time (Ct value 40) or presented significantly higher Ct values (38.2 +/- 0.96) for the nonhake species.

  8. A dynamic and mechanistic model of PCB bioaccumulation in the European hake ( Merluccius merluccius)

    NASA Astrophysics Data System (ADS)

    Bodiguel, Xavier; Maury, Olivier; Mellon-Duval, Capucine; Roupsard, François; Le Guellec, Anne-Marie; Loizeau, Véronique

    2009-08-01

    Bioaccumulation is difficult to document because responses differ among chemical compounds, with environmental conditions, and physiological processes characteristic of each species. We use a mechanistic model, based on the Dynamic Energy Budget (DEB) theory, to take into account this complexity and study factors impacting accumulation of organic pollutants in fish through ontogeny. The bioaccumulation model proposed is a comprehensive approach that relates evolution of hake PCB contamination to physiological information about the fish, such as diet, metabolism, reserve and reproduction status. The species studied is the European hake ( Merluccius merluccius, L. 1758). The model is applied to study the total concentration and the lipid normalised concentration of 4 PCB congeners in male and female hakes from the Gulf of Lions (NW Mediterranean sea) and the Bay of Biscay (NE Atlantic ocean). Outputs of the model compare consistently to measurements over the life span of fish. Simulation results clearly demonstrate the relative effects of food contamination, growth and reproduction on the PCB bioaccumulation in hake. The same species living in different habitats and exposed to different PCB prey concentrations exhibit marked difference in the body accumulation of PCBs. At the adult stage, female hakes have a lower PCB concentration compared to males for a given length. We successfully simulated these sex-specific PCB concentrations by considering two mechanisms: a higher energy allocation to growth for females and a transfer of PCBs from the female to its eggs when allocating lipids from reserve to eggs. Finally, by its mechanistic description of physiological processes, the model is relevant for other species and sets the stage for a mechanistic understanding of toxicity and ecological effects of organic contaminants in marine organisms.

  9. Genetic structure and environmental heterogeneity in the European hake (Merluccius merluccius).

    PubMed

    Cimmaruta, R; Bondanelli, P; Nascetti, G

    2005-07-01

    This study aimed at assessing the genetic structure and the state of the stocks of the European hake (Merluccius merluccius). To this end, 15 samples were taken from the whole range of the species and analysed using allozymes. Since 11 samples were taken from the poorly studied Mediterranean Sea, the results obtained provided a complete picture of the hake's genetic structure and an initial insight into its relationships with environmental features. Atlantic and Mediterranean hake populations are separated by the Almeria-Oran front. This area has been proved to be the boundary between Atlantic and Mediterranean stocks of many marine organisms, but some doubt exists concerning the efficaciousness of the local gyres as barriers to the gene flow. Our data have evidenced a latitudinal cline at loci Gapdh and Gpi-2 within the Mediterranean Sea, with a further steep change across the Almeria-Oran front. The genetic pattern showed a strong correlation with the values of the salinity both at the surface and at -320 m and of the salinity + temperature at the surface, suggesting a role for these parameters in maintaining the genetic differentiation among the two population groups through selective processes. Finally, the levels of genetic variability were found to be slightly lower in the depleted Atlantic stock than in the Mediterranean one.

  10. Outlier SNP markers reveal fine-scale genetic structuring across European hake populations (Merluccius merluccius).

    PubMed

    Milano, Ilaria; Babbucci, Massimiliano; Cariani, Alessia; Atanassova, Miroslava; Bekkevold, Dorte; Carvalho, Gary R; Espiñeira, Montserrat; Fiorentino, Fabio; Garofalo, Germana; Geffen, Audrey J; Hansen, Jakob H; Helyar, Sarah J; Nielsen, Einar E; Ogden, Rob; Patarnello, Tomaso; Stagioni, Marco; Tinti, Fausto; Bargelloni, Luca

    2014-01-01

    Shallow population structure is generally reported for most marine fish and explained as a consequence of high dispersal, connectivity and large population size. Targeted gene analyses and more recently genome-wide studies have challenged such view, suggesting that adaptive divergence might occur even when neutral markers provide genetic homogeneity across populations. Here, 381 SNPs located in transcribed regions were used to assess large- and fine-scale population structure in the European hake (Merluccius merluccius), a widely distributed demersal species of high priority for the European fishery. Analysis of 850 individuals from 19 locations across the entire distribution range showed evidence for several outlier loci, with significantly higher resolving power. While 299 putatively neutral SNPs confirmed the genetic break between basins (F(CT) = 0.016) and weak differentiation within basins, outlier loci revealed a dramatic divergence between Atlantic and Mediterranean populations (F(CT) range 0.275-0.705) and fine-scale significant population structure. Outlier loci separated North Sea and Northern Portugal populations from all other Atlantic samples and revealed a strong differentiation among Western, Central and Eastern Mediterranean geographical samples. Significant correlation of allele frequencies at outlier loci with seawater surface temperature and salinity supported the hypothesis that populations might be adapted to local conditions. Such evidence highlights the importance of integrating information from neutral and adaptive evolutionary patterns towards a better assessment of genetic diversity. Accordingly, the generated outlier SNP data could be used for tackling illegal practices in hake fishing and commercialization as well as to develop explicit spatial models for defining management units and stock boundaries. © 2013 John Wiley & Sons Ltd.

  11. Gonadotropin characterization, localization and expression in the European hake (Merluccius merluccius).

    PubMed

    Candelma, Michela; Fontaine, Romain; Colella, Sabrina; Santojanni, Alberto; Weltzien, Finn-Arne; Carnevali, Oliana

    2017-02-01

    In vertebrates, the regulation of gametogenesis is under the control of gonadotropins (Gth), follicle-stimulating hormone (Fsh) and luteinizing hormone (Lh). In fish, the physiological role of Gths is not fully understood, especially in species with asynchronous ovarian development. To elucidate the role of Gths in species with asynchronous ovary, we studied European hake (Merluccius merluccius) during the reproductive season. For this aim, we first cloned and sequenced both hormones. Then, we characterized their amino acid sequence and performed phylogenetic analyses to verify the relationship to their orthologues in other species. In addition, the quantification of gene expression during their natural reproductive season was analyzed in wild-caught female hake. Our results revealed that fshb peaked during the vitellogenic phase, remaining high until spawning. This is in contrast to the situation in species with synchronous ovary. lhb, on the other hand, peaked during maturation as it is also common in species with synchronous ovarian development. Finally, combining double-labeling fluorescent in situ hybridization (FISH) for Gth mRNAs with immunofluorescence for Lh protein, we evidenced the specific expression of fshb and lhb in different cells within the proximal pars distalis (PPD) of the pituitary. In addition to gonadotrope cells specific to expression of either fshb or lhb, some cells showed co-expression of both genes. This suggests either that gonadotropes with co-expression are not yet specified or they could have a plasticity that permits changes from one cell phenotype to another during certain life stages and in turn during different physiological states.

  12. Effect of Intestinal Tapeworm Clestobothrium crassiceps on Concentrations of Toxic Elements and Selenium in European Hake Merluccius merluccius from the Gulf of Lion (Northwestern Mediterranean Sea).

    PubMed

    Torres, Jordi; Eira, Catarina; Miquel, Jordi; Ferrer-Maza, Dolors; Delgado, Eulàlia; Casadevall, Margarida

    2015-10-28

    The capacity for heavy metal bioaccumulation by some fish parasites has been demonstrated, and their contribution to decreasing metal concentrations in tissues of parasitized fish has been hypothesized. The present study evaluated the effect of the cestode Clestobothrium crassiceps on the accumulation of trace elements in 30 European hake, Merluccius merluccius, in Spain (half of them infested by C. crassiceps). Tissue samples from all M. merluccius and specimens of C. crassiceps from the infected hakes were collected and stored until element analysis by inductively coupled plasma mass spectrometry (ICP-MS). Arsenic, mercury, and selenium were generally present in lower levels in the cestode than in all hake tissues. The mean value of the muscular Se:Hg molar ratio in the infested subsample was higher than that in hakes without cestodes. Values indicate that the edible part of infested hakes presents a lower amount of Cd and Pb in relation to noninfested hakes.

  13. First Record of Anisakis simplex Third-Stage Larvae (Nematoda, Anisakidae) in European Hake Merluccius merluccius lessepsianus in Egyptian Water

    PubMed Central

    Abou-Rahma, Yasmin; Abdel-Gaber, Rewaida; Kamal Ahmed, Amira

    2016-01-01

    The prevalence of infection and the identification of anisakid larvae in European hake Merluccius merluccius lessepsianus from Hurghada City, Red Sea Governorate, Egypt, were investigated. Fish samples were collected during the period of February and November 2014. Twenty-two (36.66%) out of sixty examined fish specimens were found to be naturally infected with Anisakis type I larvae mostly found as encapsulated larvae in visceral organs. There was a positive relationship between host length/weight and prevalence of infection. Based on morphological, morphometric, and molecular analyses, these nematodes were identified as third-stage larvae of Anisakis simplex. The present study was considered as the first report of anisakid larvae from European hake in the Egyptian water. PMID:26925257

  14. Estimation of freezing storage time and quality changes in hake (Merluccius merluccius, L.) by low field NMR.

    PubMed

    Sánchez-Alonso, Isabel; Martinez, Iciar; Sánchez-Valencia, Javier; Careche, Mercedes

    2012-12-01

    The potential of low field NMR (LF NMR) as a fast monitoring technique to estimate the quality of hake (Merluccius merluccius) frozen stored at -10°C for up to 6months was evaluated. LF NMR clearly detected three populations of water: water strongly bound to macromolecules (T(2b)), trapped water (T(21)) and free water (T(22)). As storage time increased, and concomitant with an increase in the T(22) and a decrease in the T(21) water populations, the water holding capacity (WHC) and apparent viscosity values decreased and the shear strength increased, reflecting the characteristic loss of juiciness and tougher texture developed by hake during frozen storage. Two mathematical models were constructed: a simple regression using the biexponential analysis of the relaxation times (T(21), T(22)) and amplitudes (A(21), A(22)) and a partial least square regression (PLS) of CONTIN analysis. Both models seemed suitable to estimate the quality of the product.

  15. Diel vertical migration of European hake Merluccius merluccius and associated temperature histories: insights from a pilot data-storage tagging (DST) experiment.

    PubMed

    De Pontual, H; Jolivet, A; Bertignac, M; Fablet, R

    2012-07-01

    A pioneering experiment of archival tagging of European hake Merluccius merluccius provided evidence of a diel vertical migration pattern which was analysed using an automatic method, developed and validated through time-frequency analyses. Frequent vertical movements across the thermocline were observed and fish experienced rapid temperature changes >7° C. These tagging-recapture data also suggested a homing behaviour to feeding grounds.

  16. Morphological and molecular characterisation of Aporocotyle margolisi Smith, 1967 (Digenea: Aporocotylidae) from the North Pacific hake Merluccius productus (Ayres) (Gadiformes: Merlucciidae) off Oregon, USA.

    PubMed

    Hernández-Orts, Jesus S; Hernández-Mena, David I; Alama-Bermejo, Gema; Kuchta, Roman; Jacobson, Kym C

    2017-07-06

    Aporocotylid blood flukes conspecific with Aporocotyle margolisi Smith, 1967 were collected from the bulbus arteriosus of the North Pacific hake Merluccius productus (Ayres). This study revisits the morphology of A. margolisi, including drawings, measurements and scanning electron microscopy images, and provides for the first time molecular data for the large subunit of the ribosomal RNA (28S rDNA) and the mitochondrial cytochrome c oxidase subunit 1 (cox1) genes for this species. A 28S rDNA phylogenetic study of A. margolisi, and all available Aporocotyle spp., was also performed. The distribution range of A. margolisi is extended to the Pacific coast of the USA. We provide a morphological comparison of Aporocotyle spp. from the Pacific coast in North America as well as other Aporocotyle spp. infecting hake. Comparisons with the original description revealed that the new specimens of A. margolisi were considerably larger with respect to all morphological features, except for shorter spines. Molecular results showed a close relationship between A. margolisi and A. argentinensis Smith, 1969 from the Argentine hake Merluccius hubbsi Marini. The phylogenetic relationships of Aporocotyle spp. point to a possible co-speciation of hakes species and these blood fluke parasites.

  17. Modeling real-time PCR kinetics: Richards reparametrized equation for quantitative estimation of European hake (Merluccius merluccius).

    PubMed

    Sánchez, Ana; Vázquez, José A; Quinteiro, Javier; Sotelo, Carmen G

    2013-04-10

    Real-time PCR is the most sensitive method for detection and precise quantification of specific DNA sequences, but it is not usually applied as a quantitative method in seafood. In general, benchmark techniques, mainly cycle threshold (Ct), are the routine method for quantitative estimations, but they are not the most precise approaches for a standard assay. In the present work, amplification data from European hake (Merluccius merluccius) DNA samples were accurately modeled by three sigmoid reparametrized equations, where the lag phase parameter (λc) from the Richards equation with four parameters was demonstrated to be the perfect substitute for Ct for PCR quantification. The concentrations of primers and probes were subsequently optimized by means of that selected kinetic parameter. Finally, the linear correlation among DNA concentration and λc was also confirmed.

  18. Evaluating the resolution power of new microsatellites for species identification and stock delimitation in the Cape hakes Merluccius paradoxus and Merluccius capensis (Teleostei: Merlucciidae).

    PubMed

    Hoareau, T B; Klopper, A W; Dos Santos, S M R; Oosthuizen, C J; Bloomer, P

    2015-05-01

    The utility of 15 new and 17 previously published microsatellite markers was evaluated for species identification and stock delimitation in the deep-water hake Merluccius paradoxus and the shallow-water hake Merluccius capensis. A total of 14 microsatellites were polymorphic in M. paradoxus and 10 in M. capensis. Two markers could individually discriminate the species using Bayesian clustering methods and a statistical power analysis showed that the set of markers for each species is likely to detect subtle genetic differentiation (FST < 0·006) that will be valuable to delimit and characterize genetic stocks.

  19. Structural and biochemical characterization and evolutionary relationships of the fatty acid-binding protein 10 (Fabp10) of hake (Merluccius hubbsi).

    PubMed

    Crovetto, Cecilia Alejandra; Córdoba, Osvaldo León

    2016-02-01

    A fatty acid-binding protein (FABP) from the liver of Argentine hake (Merluccius hubbsi) was isolated and characterized and its expression analyzed. The determination of its partial primary structures (72%) showed that it presents highest identity with Fabp10, commonly termed liver basic-type FABP. The evolutionary tree showed greater relationship between the Fabp10 of hake (Me Fabp10) and the Fabp10 and the Fabp10a of teleost fish. Me Fabp10 had low affinity for palmitic, oleic and palmitoleic acid and high affinity for bilirubin, lysophosphatidylcholine and lysophosphatidylethanolamine, all of them important in the metabolic functions of the liver. Me Fabp10 was able to bind only one cis-parinaric acid molecule and was found to be expressed only in the liver.

  20. Morphological, morphometric, meristic and osteological evidence for two species of hake (Actinopterygii: Gadiformes: Merluccius) in Argentinean waters.

    PubMed

    Díaz de Astarloa, J M; Bezzi, S I; González Castro, M; Mabragaña, E; Hernández, D; Delpiani, S M; Figueroa, D E; Cousseau, M B; Deli Antoni, M Y; Tringali, L

    2011-05-01

    Morphologically, both classic and landmark-based morphometry and meristic analyses of 241 specimens of Merluccius, along with the re-examination of six paratype specimens of Merluccius hubbsi, the holotype and three paratypes of Merluccius patagonicus and the syntype of Merluccius australis revealed the presence of only two species of Merluccius in Argentinean waters. Internal structures (hyomandibula, urohyal and sagitta otolith) of M. hubbsi were compared to those reported for M. patagonicus and were shown to have identical morphology. Type specimens of M. patagonicus showed a complete overlap in morphometric and meristic characters with M. hubbsi, whereas M. australis had a greater number of second dorsal and anal-fin rays, and more lateral-line scales. In addition, M. australis had a smaller eye and longer snout than M. hubbsi and M. patagonicus. The results indicate that there is no evidence for a third hake species in Argentinean waters. Merluccius patagonicus is a synonym of M. hubbsi.

  1. Age estimation of juvenile European hake Merluccius merluccius based on otolith microstructure analysis: a slow or fast growth pattern?

    PubMed

    Pattoura, P; Lefkaditou, E; Megalofonou, P

    2015-03-01

    The main goal of this study was to examine otolith microstructure and to estimate the age and growth of European hake Merluccius merluccius from the eastern Mediterranean Sea. One hundred and twenty-nine specimens ranging from 102 to 438 mm in total length (LT ) were used. Age estimations were based on the study of the otolith microstructure, which was revealed after grinding both frontal sides of otoliths. The enumerations of the daily growth increments (DGI) as well as their width (WDGI ) measurements were made on calibrated digital images. The number of DGI in otoliths ranged between 163 and 717. Four phases in the WDGI evolution were distinguished: (1) larval-juvenile pelagic phase, with an increasing trend in WDGI up to the 60th DGI, (2) settlement phase, with a short-term deceleration in WDGI between the 61st and 150th DGI, (3) juvenile demersal phase, characterized by a stabilization of WDGI from 151st to 400th DGI and (4) adult phase, with a decreasing trend in WDGI after the 400th DGI. Age, sex and month of formation were found to affect the WDGI in all phases, with the exception of age at the juvenile demersal phase. The power curve with intercept model described best the relationship of M. merluccius LT with age (TDGI ), according to Akaike criteria, revealing differences in growth between females [LT = 65 · 36(TDGI )(0 · 40) - 388 · 55] and males [LT = 69 · 32(TDGI )(0 · 37) - 352 · 88] for the sizes examined. The mean daily growth rates were 0·61 mm day(-1) for females and 0·52 mm day(-1) for males, resulting in an LT of 283 and 265 mm at the end of their first year of life. In comparison with previous studies on the Mediterranean Sea, the results of this study showed a greater growth rate, similar to results from tagging experiments and otolith microstructure analyses for M. merluccius in other geographic areas. © 2014 The Fisheries Society of the British Isles.

  2. Molecular cloning and measurement of telomerase reverse transcriptase (TERT) transcription patterns in tissues of European hake (Merluccius merluccius) and Atlantic cod (Gadus morhua) during aging.

    PubMed

    López de Abechuco, E; Bilbao, E; Soto, M; Díez, G

    2014-05-10

    Telomerase is a reverse transcriptase ribonucleoprotein that maintains the ends of linear chromosomes. This enzyme plays a major role in cell processes like proliferation, differentiation and tumorigenesis, being associated with aging and survival of species. In this study, the gene coding for TERT (Telomerase Reverse Transcriptase) of two commercial fish species, European hake (Merluccius merluccius) and Atlantic cod (Gadus morhua), has been partially cloned. A fragment of 1581bp (hake) and 633bp (cod) showed high homology (identity 74%, query cover 99%, E-value=0) with known Perciformes TERT sequences. TERT transcription patterns were assessed by qRT-PCR in different tissues of hake (brain, ovary, testis, muscle, skin, gills, liver and kidney) and cod (brain, muscle and skin) of different sizes/ages in order to understand its role in the physiological aging of teleosts. TERT was found to be ubiquitously transcribed in all tissues and size/age groups studied in both species. Significantly higher relative transcription levels (p<0.05) were found with increasing size/age of M. merluccius in the kidney, muscle, skin and gonad, the latter exhibiting particularly high relative transcription levels. Male hakes showed higher TERT relative transcription levels in the brain, gonad and liver than females, although these differences were not statistically significant (p<0.05). In G. morhua, higher TERT relative transcription levels were recorded in the muscle and brain of fry and juvenile individuals. Therefore, TERT relative transcription pattern exhibited a higher telomerase demand in early developmental stages and also in mature stages, suggesting tissue renewal or regeneration processes as a conserved mechanism for maintaining long-term cell proliferation capacity and preventing senescence. Thus, it can be concluded that TERT relative transcription level was species and tissue specific and changed with the age of fishes.

  3. Molecular Cytogenetic Analysis of the European Hake Merluccius merluccius (Merlucciidae, Gadiformes): U1 and U2 snRNA Gene Clusters Map to the Same Location.

    PubMed

    García-Souto, Daniel; Troncoso, Tomás; Pérez, Montse; Pasantes, Juan José

    2015-01-01

    The European hake (Merluccius merluccius) is a highly valuable and intensely fished species in which a long-term alive stock has been established in captivity for aquaculture purposes. Due to their huge economic importance, genetic studies on hakes were mostly focused on phylogenetic and phylogeographic aspects; however chromosome numbers are still not described for any of the fifteen species in the genus Merluccius. In this work we report a chromosome number of 2n = 42 and a karyotype composed of three meta/submetacentric and 18 subtelo/telocentric chromosome pairs. Telomeric sequences appear exclusively at both ends of every single chromosome. Concerning rRNA genes, this species show a single 45S rDNA cluster at an intercalary location on the long arm of subtelocentric chromosome pair 12; the single 5S rDNA cluster is also intercalary to the long arm of chromosome pair 4. While U2 snRNA gene clusters map to a single subcentromeric position on chromosome pair 13, U1 snRNA gene clusters seem to appear on almost all chromosome pairs, but showing bigger clusters on pairs 5, 13, 16, 17 and 19. The brightest signals on pair 13 are coincident with the single U2 snRNA gene cluster signals. Therefore, the use of these probes allows the unequivocal identification of at least 7 of the chromosome pairs that compose the karyotype of Merluccius merluccius thus opening the way to integrate molecular genetics and cytological data on the study of the genome of this important species.

  4. Molecular Cytogenetic Analysis of the European Hake Merluccius merluccius (Merlucciidae, Gadiformes): U1 and U2 snRNA Gene Clusters Map to the Same Location

    PubMed Central

    García-Souto, Daniel; Troncoso, Tomás; Pérez, Montse; Pasantes, Juan José

    2015-01-01

    The European hake (Merluccius merluccius) is a highly valuable and intensely fished species in which a long-term alive stock has been established in captivity for aquaculture purposes. Due to their huge economic importance, genetic studies on hakes were mostly focused on phylogenetic and phylogeographic aspects; however chromosome numbers are still not described for any of the fifteen species in the genus Merluccius. In this work we report a chromosome number of 2n = 42 and a karyotype composed of three meta/submetacentric and 18 subtelo/telocentric chromosome pairs. Telomeric sequences appear exclusively at both ends of every single chromosome. Concerning rRNA genes, this species show a single 45S rDNA cluster at an intercalary location on the long arm of subtelocentric chromosome pair 12; the single 5S rDNA cluster is also intercalary to the long arm of chromosome pair 4. While U2 snRNA gene clusters map to a single subcentromeric position on chromosome pair 13, U1 snRNA gene clusters seem to appear on almost all chromosome pairs, but showing bigger clusters on pairs 5, 13, 16, 17 and 19. The brightest signals on pair 13 are coincident with the single U2 snRNA gene cluster signals. Therefore, the use of these probes allows the unequivocal identification of at least 7 of the chromosome pairs that compose the karyotype of Merluccius merluccius thus opening the way to integrate molecular genetics and cytological data on the study of the genome of this important species. PMID:26716701

  5. Nursery areas of red mullet ( Mullus barbatus), hake ( Merluccius merluccius) and deep-water rose shrimp ( Parapenaeus longirostris) in the Eastern-Central Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Carlucci, Roberto; Giuseppe, Lembo; Porzia, Maiorano; Francesca, Capezzuto; Alessandra, Marano Chiara; Letizia, Sion; Teresa, Spedicato Maria; Nicola, Ungaro; Angelo, Tursi; D'Onghia, Gianfranco

    2009-08-01

    The spatial pattern of the nursery areas of red mullet ( Mullus barbatus), hake ( Merluccius merluccius) (Linnaeus, 1758) and deep-water rose shrimp ( Parapenaeus longirostris) (Lucas, 1846) was studied in the South Adriatic and North Ionian Seas (Eastern-Central Mediterranean) applying geostatistical techniques and data from time series trawl surveys conducted in the area. The analysed variables were: R (number of recruits/km 2) and R/Tot (fraction of recruits on the total sampled population). The structural analysis showed a spatial pattern of both variables characterized by continuity on a small scale. Predictions of nursery area localization with probability of finding recruits at different threshold values were obtained through median indicator kriging. For the red mullet the nurseries were mainly identified in the South Adriatic Sea off the Gargano peninsula and between Molfetta and Monopoli within 50 m in depth. The main concentration of hake juveniles was found to be between 100 and 200 m in depth along the Gargano peninsula and between Otranto and Santa Maria di Leuca, where a nursery of deep-water rose shrimp was also detected. An overlapping depth, between 100 and 200 m, was identified for hake and deep-water rose shrimp nurseries. Protection of these areas through limitations of fishing pressure is discussed.

  6. ITS1-rDNA-based methodology to identify world-wide hake species of the Genus Merluccius.

    PubMed

    Pérez, Montse; Vieites, Juan M; Presa, Pablo

    2005-06-29

    Species-specific DNA-based tags are valuable tools for the management of both fisheries and commercial fish products. In this study, we have developed a two-step molecular tool to detect the presence of hake DNA (Merluccius spp.) and to identify the exact hake species present in an blind sample. The first test involves PCR amplification of an ITS1-rDNA fragment of 193 bp using nested primers that are interspecifically conserved in Merluccius spp. and Atlantic cod, Gadus morhua. The second test consists of the PCR amplification of a 602-659 bp DNA fragment spanning part of the ribosomal cluster 18S-ITS1-5.8S and digesting it with four restriction enzymes whose targets map at interspecifically nonconserved sites of the ITS1. Alternatively, the identification of hake species can be achieved by FINS or BLAST, using the nucleotide sequence of either the whole ITS1 sequence or its nested fragment of 193 bp. Because of their high reproducibility and ease of execution, these procedures allow for routine analysis and constitute high reliable tools for the rapid identification of 12 species of hake.

  7. Seasonal and short spatial patterns in European hake ( Merluccius merluccius L.) recruitment process at the Balearic Islands (western Mediterranean): The role of environment on distribution and condition

    NASA Astrophysics Data System (ADS)

    Hidalgo, Manuel; Massutí, Enric; Moranta, Joan; Cartes, Joan; Lloret, Josep; Oliver, Pere; Morales-Nin, Beatriz

    2008-06-01

    This study evaluates the link between the recruitment process of European hake ( Merluccius merluccius L.) of the Balearic Islands (western Mediterranean) and the environmental and physiological conditions. Spatio-temporal variation of abundance and condition of fish were evaluated at two locations each with different oceanographic conditions, one in the north (Sóller, SO) and another in the south (Cabrera, CA) of Mallorca Island. Environmental variables explored were hydrography, sediment characteristics, phytoplankton pigment concentration (ppc) and the trophic resources of hake. Individuals were divided in three life stages: recruits, post-recruits and young adults. Hepatosomatic index (HSI), relative condition index (K n), gonadosomatic index (GSI) and fullness index (FI) were analysed for the three life stages. Recruitment starts in February with the incorporation of smaller hakes, and it can be followed through spring and early summer with a peak in April. However, some spatial heterogeneity in the recruitment process has been found between north and south of the Island. The main pulse of recruitment occurred at a different time in the two areas. Spatial heterogeneity was also consistent with the condition of hake recruits, with higher values of K n and HSI at SO than at CA. Maximum values of K n were found in February at SO and in April at CA, coinciding with the start of the different recruitment pulses to the fishing grounds. Post-recruits and young adults also showed higher condition at SO than at CA. The arrival in spring of the Western Winter Intermediate Waters (WIW) drives the spatial-temporal variation in abundance and condition of hake. Ppc was highly correlated with recruit abundance with a time lag of two months, while for post-recruits the time lag was three months. The observed differences in the condition of hake between areas could be a consequence of the fact that the waters to the north of Mallorca are comparatively more under the seasonal

  8. When homoplasy mimics hybridization: a case study of Cape hakes (Merluccius capensis and M. paradoxus)

    PubMed Central

    von der Heyden, Sophie; Matthee, Conrad A.

    2016-01-01

    In the marine environment, an increasing number of studies have documented introgression and hybridization using genetic markers. Hybridization appears to occur preferentially between sister-species, with the probability of introgression decreasing with an increase in evolutionary divergence. Exceptions to this pattern were reported for the Cape hakes (Merluccius capensis and M. paradoxus), two distantly related Merluciidae species that diverged 3–4.2 million years ago. Yet, it is expected that contemporary hybridization between such divergent species would result in reduced hybrid fitness. We analysed 1,137 hake individuals using nine microsatellite markers and control region mtDNA data to assess the validity of the described hybridization event. To distinguish between interbreeding, ancestral polymorphism and homplasy we sequenced the flanking region of the most divergent microsatellite marker. Simulation and empirical analyses showed that hybrid identification significantly varied with the number of markers, model and approach used. Phylogenetic analyses based on the sequences of the flanking region of Mmerhk-3b, combined with the absence of mito-nuclear discordance, suggest that previously reported hybridization between M. paradoxus and M. capensis cannot be substantiated. Our findings highlight the need to conduct a priori simulation studies to establish the suitability of a particular set of microsatellite loci for detecting multiple hybridization events. In our example, the identification of hybrids was severely influenced by the number of loci and their variability, as well as the different models employed. More importantly, we provide quantifiable evidence showing that homoplasy mimics the effects of heterospecific crossings which can lead to the incorrect identification of hybridization. PMID:27069785

  9. Effect of added lipids on the texture of minced hake (Merluccius merluccius L.), megrim (Lepidorhombus whiffiagonis W.) and sardine (Sardina pilchardus W.) during frozen storage.

    PubMed

    Careche, M; Tejada, M

    1991-12-01

    The effect of added cod liver oil and oxidized cod liver oil on the measurement of texture in minced hake (Merluccius merluccius L.), megrim (Lepidorhombus whiffiagonis W.) and sardine (Sardina pilchardus W.) has been measured during frozen storage (-18 degrees C). The results show that added neutral and oxidized lipids, even at high rancidity levels, do not affect shear resistances measured by the Kramer shear-compression cell in non-formaldehyde forming species such as megrim and sardine, over the frozen storage period. However, in a formaldehyde-forming species such as hake, in the presence of neutral and oxidized lipids at the end of the storage period, the values of shear resistances may be lower than in the absence of these lipids, probably owing to formation of less formaldehyde in these cases. Although it is very difficult to estimate the importance of a single compound or group of compounds on texture, these results seem to indicate that formaldehyde is a much more important factor than oxidized lipids in changes of texture in fish.

  10. Low field nuclear magnetic resonance (LF-NMR) relaxometry in hake (Merluccius merluccius, L.) muscle after different freezing and storage conditions.

    PubMed

    Sánchez-Alonso, Isabel; Moreno, Pilar; Careche, Mercedes

    2014-06-15

    Low field NMR T2 transverse relaxation measurements were performed on muscle samples from sixty hake (Merluccius merluccius, L.). Fish fillets from hake stored in ice for 3 and 14 days were subjected to different freezing methods (air blast, liquid nitrogen or walk-in freezer) and storage conditions (-20 and -10°C for 5 days, 8 and 18 weeks). Distribution analysis of T2 data of unfrozen muscle displayed a major band (T21), accounting for 90-92% of the total signal, with a relaxation time centred at 47-60 ms and a broad band with protons of higher mobility between 300 and 800 ms, accounting for 3-5% of the signal. Upon freezing, T21 became wider and an extra band appeared within the range 120-360 ms. Whereas no changes were detected at -20°C, the T21 time constant decreased during frozen storage at -10°C in a similar way for all three freezing methods. The relative abundance of T21 declined with storage time but differences were found as a function of freezing. Results are discussed in the light of morphological alterations and protein denaturation, and it is concluded that LF NMR relaxometry is sensitive to different freezing and frozen storage conditions which can have important implications for the quality of fish muscle.

  11. Endotoxin and biogenic amine levels in Atlantic mackerel (Scomber scombrus), sardine (Sardina pilchardus) and Mediterranean hake (Merluccius merluccius) stored at 22 degrees C.

    PubMed

    Prester, Ljerka; Macan, Jelena; Varnai, Veda Marija; Orct, Tatjana; Vukusic, Jelena; Kipcic, Dubravka

    2009-03-01

    Whole Atlantic mackerel (Scomber scombrus), sardine (Sardina pilchardus) and Mediterranean hake (Merluccius merluccius) from the Croatian Adriatic were stored at 22 degrees C and changes in histamine, putrescine, tyramine and cadaverine levels were monitored in relation to bacterial endotoxin. After 12 h, histamine levels in sardine were above the legal limit of 50 mg kg(-1), set by the US Food and Drug Administration, and an increase in putrescine content preceded the increase in histamine. After 24 h, histamine contents in mackerel and sardine reached 1090 +/- 101 and 577 +/- 275 mg kg(-1), respectively, which exceeded the toxic threshold of 500 mg kg(-1). At the same time, the putrescine content was also high in both fish (353-420 mg kg(-1)). The time-course of endotoxin production was similar in all fish species stored at 22 degrees C. A high correlation was found between endotoxin and histamine, and between endotoxin and putrescine in mackerel and sardine. On the other hand, high endotoxin levels in hake, after 24 h, were associated with the low histamine and putrescine content (40-60 mg kg(-1)).

  12. Influences of bioavailability, trophic position, and growth on methylmercury in hakes (Merluccius merluccius) from Northwestern Mediterranean and Northeastern Atlantic.

    PubMed

    Cossa, D; Harmelin-Vivien, M; Mellon-Duval, C; Loizeau, V; Averty, B; Crochet, S; Chou, L; Cadiou, J-F

    2012-05-01

    Methylmercury (MeHg) determinations in hake, its food-chain, and the surrounding waters and sediments allowed us to show that the higher length or age normalized mercury concentrations of Northwestern Mediterranean (Gulf of Lions: GoL) muscle hakes compared to its Northeastern Atlantic (Bay of Biscay: BoB) counterpart are due to both biotic and abiotic differences between their ecosystems. Bioenergetic modeling reveals that the slower growth rate of Mediterranean hake favors the MeHg bioaccumulation in the fish muscle and explains most of the difference between GOL and BoB hake populations. In addition, the waters of the Mediterranean hake habitat favor a higher MeHg exposition, due to the upper position of the thermohalocline, where MeHg is formed. Furthermore, we show that, within the Mediterranean hake population, a major increase in the biomagnification power (the slope of the relationships between logMeHg and δ(15)N), from 0.36 up to 1.12, occurs when individuals enter adulthood, resulting from the combined effects of lowering growth rate and change in feeding habits. Finally, δ(15)N normalized Hg concentrations indicate that the highest Hg concentrations are for hake from the shelf edge and the lowest are for hake from the Rhône prodelta area, suggesting a lower Hg bioavailability in inshore environments, consistent with MeHg distributions in water, sediment, and preys. © 2012 American Chemical Society

  13. Changes in the diet and feeding of the hake Merluccius merluccius at the shelf-break of the Balearic Islands: Influence of the mesopelagic-boundary community

    NASA Astrophysics Data System (ADS)

    Cartes, Joan E.; Hidalgo, Manuel; Papiol, Vanesa; Massutí, Enric; Moranta, Joan

    2009-03-01

    Short spatio-temporal variations in the feeding intensity and the diet of the European hake, Merluccius merluccius, together with the abundance of their potential prey were studied between August 2003 and June 2004 at two locations, northwest (Sóller) and south (Cabrera), off the island of Mallorca (Balearic Islands, Western Mediterranean) at depths between 150 and 750 m. The two areas present different oceanographic conditions. Hake was mainly distributed along the shelf-slope break and the upper slope (between 166 and 350 m) where recruits (TL<18 cm) were dominant. The hake's diet varied as a function of size. Recruits fed mainly on micronektonic prey, and the diet was influenced primarily by seasonality, with two dietary patterns (identified by MDS analyses) corresponding to August-September 2003 (summer) and to November 2003/February-April 2004 (autumn-winter). The summer pattern was consistent with a thermally stratified water column, while November and April were consistent with homogenized temperature and salinity throughout all the water column. The main prey of recruits were the euphausiid Meganyctiphanes norvegica and the midwater fish Maurolicus muelleri in autumn-winter and myctophids (mainly Ceratoscopelus maderensis) in summer. In contrast to recruits, the geographic factor (NW vs. S) was the main factor influencing the diets of post-recruits (TL between 18 and 21.9 cm) and adults (TL⩾22 cm). Hake recruits (and to a lesser extent post-recruits) and their preferred prey occupied different depth ranges during daylight periods. Meganyctiphanes norvegica and Ceratoscopelus maderensis were, for instance, distributed as much as 500 m deeper than hake that had eaten them. All these trends were especially obvious at NW, an area with a more abrupt slope and with a greater influence by northern winter intermediate water (WIW) inflow in early spring than the S area. These factors probably enhanced micronekton aggregation in April, when feeding intensity

  14. Pacific hake (Merluccius productus) hydrolysates as cryoprotective agents in frozen pacific cod fillet mince.

    PubMed

    Cheung, Imelda W Y; Liceaga, Andrea M; Li-Chan, Eunice C Y

    2009-10-01

    Fish protein hydrolysates produced by proteolysis of Pacific hake (Merluccius productus) with Alcalase (FPH-A) or Flavourzyme (FPH-F) were investigated as a potential alternative to the 1 : 1 blend of sucrose-sorbitol (SuSo) commonly used for cryoprotection of frozen fish mince. The physicochemical properties of cod mince samples in the absence (control) or presence of 8% FPH-A, FPH-F, or SuSo were evaluated before and after 6 freeze-thaw cycles, with differences noted at the 5% significance level. Freeze-thawing of control sample increased expressible moisture (from 22% to 33%) and cook loss (from 3% to 16%). These poor water retention properties were improved in samples containing FPH or SuSo. Differential scanning calorimetry showed higher proportion of unfrozen water in freeze-thawed samples containing FPH-F or FPH-A (0.36 g/g) compared to SuSo (0.33 g/g) and control (0.24 g/g) samples. Textural analysis of cooked mince from unfrozen samples indicated greater hardness for FPH than SuSo and control samples, while freeze-thawing resulted in decreased hardness for FPH and SuSo samples. Content and surface hydrophobicity of extractable natural actomyosin (NAM) were maintained after freeze-thawing of samples containing FPH-F or SuSo, compared to 50% decrease in extractable NAM and a significant increase in surface hydrophobicity for the control. The presence of oligopeptides in both hydrolysates and the high levels of free amino acids including Asp, Glu, Arg, and Lys in FPH-F might be responsible for their cryoprotective action. This study provides strong evidence to support development of FPH as a new generation cryoprotectant to maintain quality of frozen fish.

  15. [Lipid profile analysis of two species of hake "merluccius capensis and merluccius paradoxus" and its contribution to cardiovascular disease prevention].

    PubMed

    Piñeiro Corrales, Guadalupe; Lago Rivero, N; Olivera Fernández, R; Culebras-Fernandez, Jesus M

    2013-01-01

    Introducción: En los últimos 2013s se ha demostrado que los AGPI omega-3 presentan múltiples efectos protectores cardiovasculares. Actualmente, el pescado constituye la principal y la más importante fuente de ácidos grasos Omega-3. Objetivo: Analizar la composición en ácidos grasos en dos especies de merluza, determinar su contenido en ácidos grasos omega-3 y estudiar su aportación en la prevención de enfermedades cardiovasculares. Material y métodos: Se han analizado muestras de dos especies de merluza (Merluccius capensis y Merluccius paradoxus) en su estado natural y congeladas, cocinadas al microondas y muestras hervidas. Se ha estudiado el contenido en humedad, contenido lipídico y el análisis, composición e identificación de ácidos grasos. Resultados: Se observó que el contenido de AGPI w-3 fue mayor que el de AGPI w-6. Los ácidos grasos omega-3 DHA y EPA fueron los más representativos de la familia omega-3, destacando el contenido de DHA en todas lasmuestras analizadas. Asimismo, se ha demostrado la seguridad de los métodos de cocción «microondas» y «hervido» como métodos que aseguran la integridad de los AGPI w-3. Conclusión: Las muestras de merluza analizadas presentan un óptimo perfil lipídico. Su contenido en AGPI w-3 y sus propiedades, hacen que la merluza se distinga como pescado de referencia en dietas cardiosaludables.

  16. Genetic identification and distribution of the parasitic larvae of Anisakis pegreffii and Anisakis simplex (s. s.) in European hake Merluccius merluccius from the Tyrrhenian Sea and Spanish Atlantic coast: implications for food safety.

    PubMed

    Cipriani, Paolo; Smaldone, Giorgio; Acerra, Virginia; D'Angelo, Luisa; Anastasio, Aniello; Bellisario, Bruno; Palma, Giuseppe; Nascetti, Giuseppe; Mattiucci, Simonetta

    2015-04-02

    The consumption of the hake Merluccius merluccius is widespread in European countries, where this fish has a high commercial value. To date, different larval species of Anisakis have been identified as parasites in M. merluccius from European waters, Anisakis pegreffii and Anisakis simplex (s. s.) being the two most common. The aim of the study is to present data on the occurrence of Anisakis spp. larvae in the viscera and flesh of M. merluccius. Consequently, the distribution and infection rates of different species of Anisakis in different sites (viscera, and dorsal and ventral fillets) were investigated in hake caught in the central Tyrrhenian Sea (FAO 37.1.3) and the NE Atlantic Ocean (FAO 27 IXa). A sample of N=65 fish individuals (length>26 cm) was examined parasitologically from each fishing ground. The fillets were examined using the pepsin digestion method. A large number (1310) of Anisakis specimens were identified by multilocus allozyme electrophoresis (MAE) and mtDNA cox2 sequence analysis; among these, 814 larvae corresponded to A. simplex (s. s.) and 476 to A. pegreffii. They were found to infect both the flesh and the viscera. The two species co-infected the same individual fish (both in the viscera and in the flesh) from the FAO 27 area, whereas only A. pegreffii was found in hake from the Tyrrhenian Sea. The average parasite burden of A. pegreffii in hake from the Tyrrhenian Sea was significantly lower to that observed from hake off the Atlantic coast of Spain, both in prevalence and in abundance. In addition, whereas no significant difference in overall prevalence values was recorded between the two Anisakis species in the viscera of the FAO 27 sample, significant differences were found in the abundance levels observed between these species in the flesh, with A. simplex (s. s.) exhibiting significantly higher levels than that observed for A. pegreffii (p<0.001). Given that the pathogenic role in relation to man is known for these two species of

  17. The impact of overfishing and El Niño on the condition factor and reproductive success of Peruvian hake, Merluccius gayi peruanus

    NASA Astrophysics Data System (ADS)

    Ballón, Michael; Wosnitza-Mendo, Claudia; Guevara-Carrasco, Renato; Bertrand, Arnaud

    2008-10-01

    In this study we examine physiological responses of Peruvian hake ( Merluccius gayi peruanus) to changes in their population structure and physical environment during the period 1971-2004. In particular, we assess the relative investment of energy in growth and/or reproduction of small (20-35 cm) and large (35-50 cm) hake. We calculated the (i) condition (Fulton’s K), (ii) gonad and (iii) gut fullness indices for 42,761 female hakes sampled from commercial landings; these indices indicate fish somatic, reproductive and feeding condition, respectively. Using Generalized Additive Models we then examined potential relationships between these indices and sea surface temperature anomalies and date. Drastic energy exhaustion and a decrease in female hake fecundity were observed during El Niño events. The long-term trend showed a general increase in condition factor and a decrease in gonad index for large hake between 1971 and 2004. Small hake exhibited a different trend with an increase in reproductive activity, which was accompanied by an earlier maturation. We hypothesise that the observed low investment of energy in reproduction by large female hake might be related to the lack of large males, due to a sex-selective fishery and the impact of El Niño. We suggest that fishing diminished hake reproductive capacity, modified the sex ratio in favour of females and increased population vulnerability to environmental stress, in particular to the El Niño. The impact of multidecadal variability and predators like the squid, Dosidicus gigas, remain unresolved until longer time series become available.

  18. Influence of sex, maturity and reproduction on PCB and p,p'DDE concentrations and repartitions in the European hake (Merluccius merluccius, L.) from the Gulf of Lions (N.W. Mediterranean).

    PubMed

    Bodiguel, Xavier; Loizeau, Véronique; Le Guellec, Anne-Marie; Roupsard, François; Philippon, Xavier; Mellon-Duval, Capucine

    2009-12-20

    The main objective of this work was to establish the influence of sex, maturity and reproduction on the contamination of the demersal fish Merluccius merluccius by organochlorine compounds. Polychlorinated biphenyls (PCBs) and p,p'DDE were quantified in muscle, liver and gonads of female and male hakes collected in the Gulf of Lions in 2004 and 2005. Observed levels appeared higher than the population of the Bay of Biscay and lower than the population of the Thyrrenian Sea. Contaminant fingerprints were roughly constant whatever the studied organ and the hake biological condition. Concentrations varied significantly according to the sex and maturity of hakes. Mature specimens were more contaminated than immature, and males presented higher levels than females. This sex effect can be linked to a lower growth rate of males, and a contaminant elimination during female spawning. Gonadal contamination depends on the importance of lipid content and increases with the maturation degree. Although the main organ of energy and PCB storage is the liver, muscle appears as the main contributor to the gonad contamination.

  19. Cooperation between scientists, NGOs and industry in support of sustainable fisheries: the South African hake Merluccius spp. trawl fishery experience.

    PubMed

    Field, J G; Attwood, C G; Jarre, A; Sink, K; Atkinson, L J; Petersen, S

    2013-10-01

    This paper examines the increasingly close interaction between natural and social scientists, non-governmental organizations (NGO) and industry, in pursuit of responsible ecosystem-based management of fisheries. South Africa has committed to implementing an ecosystem approach to fisheries management. Management advice stems from multi-stakeholder representation on government-led scientific and management working groups. In the hake Merluccius capensis and Merluccius paradoxus fishery, the primary management measure is an annual total allowable catch (TAC), the level of which is calculated using a management procedure (MP) that is revised approximately every 4 years. Revision of the MP is a consultative process involving most stakeholders, and is based on simulation modelling of projected probable scenarios of resource and fishery dynamics under various management options. NGOs, such as the Worldwide Fund for Nature in South Africa (WWF-SA), have played an important role in influencing consumers, the fishing industry and government to develop responsible fishing practices that minimize damage to marine ecosystems. Cooperation between industry, government and scientists has helped to improve sustainability and facilitated the meeting of market-based incentives for more responsible fisheries. Research includes ecosystem modelling, spatial analysis and ecosystem risk assessment with increasing research focus on social and economic aspects of the fishery. A four-year cooperative experiment to quantify the effect of trawling on benthic community structure is being planned. The food requirements of top predators still need to be included in the TAC-setting formulae and more social and economic research is needed. This paper also demonstrates how NGO initiatives such as Marine Stewardship Council certification and the Southern African Sustainable Seafood Initiative, a traffic light system of classifying seafood for consumers, have contributed to responsible fishing

  20. Biannual otolith-zone formation of young shallow-water hake Merluccius capensis in the northern Benguela: age verification using otoliths sampled by a top predator.

    PubMed

    Wilhelm, M R; Roux, J-P; Moloney, C L; Jarre, A

    2015-07-01

    Otoliths collected at least monthly from scat samples of Cape fur seals Arctocephalus pusillus are used to show that shallow-water hake Merluccius capensis from the northern Benguela develop three translucent zones in their first 1·5 years of life. The novel sampling approach provided otoliths that belonged to four M. capensis cohorts of approximate known age (hatched in 1996, 1998, 2002 and 2005), allowing age verification. Following spawning in austral winter, translucent zones consistently formed first in summer and autumn (T1), then in winter and spring (T2) and again in summer and autumn (T3), with no difference in appearance of the zones (biannuli) for the four cohorts considered. The second translucent zone is usually the first true annulus (year mark). It forms during July to September in fish of 15-20 cm total length (LT ). Formation of the translucent zones appears to be determined by fish length or age, rather than by exogenous cues. It is suggested that length measurements should be used to help determine the first age group; fish with a translucent zone marked at otolith lengths >7·5 mm should be termed 1 year-old fish. Ages of M. capensis used in previous stock assessment models have been overestimated. Biannuli are an unusual occurrence in fish otoliths in general, but have been observed in other Merluccius species. © 2015 The Fisheries Society of the British Isles.

  1. Otolith Trace Elemental Analyses of South American Austral Hake, Merluccius australis (Hutton, 1872) Indicates Complex Salinity Structuring on their Spawning/Larval Grounds

    PubMed Central

    Brickle, Paul; Schuchert, Pia C.; Arkhipkin, Alexander I.; Reid, Malcolm R.; Randhawa, Haseeb S.

    2016-01-01

    Trace element signatures of otolith edges and cores from 335 austral hake (Merluccius autralis) were analysed using LA-ICPMS from samples collected in Chilean and Falkland Islands' waters, in order to provide potential insights into stock discrimination and migrations. Fish were caught in two locations in Chile and four locations in the south-west of the Falkland Islands Shelf. Univariate and multivariate analyses of trace element signatures in the edges of otoliths, representing adult fish, were not able to distinguish between samples collected in Chile and the Falkland Islands. Cluster analyses based on Ward’s similarity/distance metric suggested that it was possible to identify two groups from core signatures. Further analyses of this perceived clustering of the core concentrations revealed that this was largely due to the wide spread of Sr/Ca ratios in the otoliths’ cores. Gaussian finite mixtures using MCMC methods confirmed that Sr/Ca ratios form two separate distributions with significantly different mean values while concentrations of other elements showed no evidence of the presence of two or more distributions. The results suggest that there is only one spawning stock of austral hake with spawning situated in and around the Chilean fjords (43°30’S– 47°S) and the variation in Sr/Ca ratios likely suggests complex salinity structuring in this area. PMID:26727274

  2. Histopathological indices in sole (Solea solea) and hake (Merluccius merluccius) for implementation of the European Marine Strategy Framework Directive along the Basque continental shelf (SE Bay of Biscay).

    PubMed

    Cuevas, Nagore; Zorita, Izaskun; Costa, Pedro M; Quincoces, Iñaki; Larreta, Joana; Franco, Javier

    2015-05-15

    Sole and hake, together with sediments, were collected during two campaigns along the Basque continental shelf to study the utility of two existing histopathological indices for assessing the biological effects of contaminants to implement the European Marine Strategy Framework Directive. Hepatic and gonadal histopathology were measured, and metal and/or organic contaminants were determined in both liver and sediments. Sediments from the Basque continental shelf were found to be moderately impacted by metals but non-impacted by organic compounds. Metal bioaccumulation and histopathological lesions in liver were higher in sole than in hake, although non-specific and early non-neoplastic toxicopathic lesions were observed in both species. No gross alterations were recorded in gonad. The two histopathological indices applied were highly correlated in both organs but the lack of correlation between sediment contamination levels, bioaccumulation and histopathological indices suggests that other factors, rather than pollution alone, are responsible for the biological effects observed.

  3. Seasonal and annual variation in Chilean hake Merluccius gayi spawning locations and egg size off central Chile

    NASA Astrophysics Data System (ADS)

    Landaeta, Mauricio F.; Castro, Leonardo R.

    2012-01-01

    Variability in Chilean hake reproductive tactics off central Chile was assessed by analyzing ichthyoplankton samples from nine oceanographic cruises (1996-2005) and through experimental trials with early life stages (eggs, yolk-sac larvae) during the main (austral spring) and secondary (late summer-early autumn) spawning seasons. Abundant eggs in the plankton (1300-2000 eggs per 10 m 2) and historical adult reproductive data showed the highest reproductive activity in austral spring, with large egg aggregations near shelf break (50-100 m depth). Large, recently spawned eggs (1.15-1.20 mm diameter) were advected nearshore by coastward subsurface flows in the spring upwelling season. Experimental trials indicated that recently hatched larvae (3.4-3.5 mm) consumed their yolk-sac (0.17-0.41 mm 3) in 3-4 days at 10-12 °C; plankton sampling indicated that larval hake remained at mid-depth (50-100 m) without showing daily vertical migrations until completing their caudal fin formation (∼15 mm). During the secondary reproductive peak, hake spawned nearshore, when smaller eggs (0.95-1.13 mm) and recently hatched larvae (2.2-2.6 mm notochord length) occurred in surface waters (0-10 m depth). Their relatively large yolk-sac volumes (0.57 ± 0.11 mm 3) provided endogenous nourishment for at least 5 days at 10 °C, according to experiments. In the field, preflexion larvae occurred mainly in the mixed layer (0-25 m) and started ontogenetic daily vertical migrations at 7 mm. A strong decline occurred after 2002 in the adult Chilean hake biomass (estimated by hydroacoustic surveys) and body size, coinciding with variations in spawning locations (more coastward in early spring 2004 and 2005) and decline in egg size. Thus, recent variations in Chilean hake reproductive tactics may reflect an indirect effect of declines in the parental population size.

  4. Cholesterol oxidation is increased and PUFA decreased by frozen storage and grilling of Atlantic hake fillets (Merluccius hubbsi).

    PubMed

    Saldanha, Tatiana; Bragagnolo, Neura

    2007-07-01

    Fresh fillets of Atlantic hake were stored at -18 degrees C for 120 days and changes in lipid composition and the formation of cholesterol oxidation products (COP) during storage and subsequent grilling were evaluated. Fresh hake showed low COP levels (8.0 microg/g, dry basis); however, a significant increase in COP (P < 0.02) and a concomitant decrease in the cholesterol and polyunsaturated fatty acids content during frozen storage and after grilling were observed. The main cholesterol oxides present in the analyzed samples were: 19-Hydroxycholesterol, 24(S)-hydroxycholesterol, 22(S)-hydroxycholesterol, 25-hydroxycholesterol, 25(R)-hydroxycholesterol and 7-Ketocholesterol. The oxides which were more influenced by the thermal treatment were 24(S)-OH and 25(R)-OH; however, after 120 days of storage 7-ketocholesterol was the main product formed. Frozen storage and subsequent grilling under domestic conditions are important factors in damage of cholesterol and unsaturated fatty acids levels, with consequent production of cholesterol oxides, although the mechanism of the formation of these compounds by the different processes is probably different.

  5. Identification of commercial hake and grenadier species by proteomic analysis of the parvalbumin fraction.

    PubMed

    Carrera, Mónica; Cañas, Benito; Piñeiro, Carmen; Vázquez, Jesús; Gallardo, José Manuel

    2006-10-01

    Analysis of parvalbumin fractions through proteomic methodologies allowed the differential classification of ten commercial, closely related species of the family Merlucciidae. Muscle extracts from nine hake species of the genus Merluccius including two subspecies of Merluccius australis (australis and polylepsis) and one grenadier species Macruronus novaezelandiae with two populations (novaezelandiae and magellanicus) were evaluated by 2-DE and MALDI-TOF MS. 2-DE demonstrated that the species tested displayed a low intra-specific degree of polymorphism and the isoform patterns were noticeably species-specific. MALDI-TOF mass fingerprints showed clear differences in the pattern of peptides produced by tryptic digestion between the Merluccius and the Macruronus, making the genus differentiation possible. In addition, a selective peptide mass present in the spectra from certain hakes allowed its classification in two groups: Euro-African and American hakes. Besides, some specific masses allowed a clearly individual identification for M. bilinearis, M. australis polylepsis, M. australis australis, M. productus, M. paradoxus and M. polli, while the rest of the hake species can be grouped in two clusters, comprising M. hubbsi and M. gayi in one and M. merluccius and M. capensis in the other.

  6. Silver hake tracks changes in Northwest Atlantic circulation.

    PubMed

    Nye, Janet A; Joyce, Terrence M; Kwon, Young-Oh; Link, Jason S

    2011-08-02

    Recent studies documenting shifts in spatial distribution of many organisms in response to a warming climate highlight the need to understand the mechanisms underlying species distribution at large spatial scales. Here we present one noteworthy example of remote oceanographic processes governing the spatial distribution of adult silver hake, Merluccius bilinearis, a commercially important fish in the Northeast US shelf region. Changes in spatial distribution of silver hake over the last 40 years are highly correlated with the position of the Gulf Stream. These changes in distribution are in direct response to local changes in bottom temperature on the continental shelf that are responding to the same large scale circulation change affecting the Gulf Stream path, namely changes in the Atlantic meridional overturning circulation (AMOC). If the AMOC weakens, as is suggested by global climate models, silver hake distribution will remain in a poleward position, the extent to which could be forecast at both decadal and multidecadal scales.

  7. Use of sand wave habitats by silver hake

    USGS Publications Warehouse

    Auster, P.J.; Lindholm, J.; Schaub, S.; Funnell, G.; Kaufman, L.S.; Valentine, P.C.

    2003-01-01

    Silver hake Merluccius bilinearis are common members of fish communities in sand wave habitats on Georges Bank and on Stellwagen Bank in the Gulf of Maine. Observations of fish size v. sand wave period showed that silver hake are not randomly distributed within sand wave landscapes. Regression analyses showed a significant positive relationship between sand wave period and fish length. Correlation coefficients, however, were low, suggesting other interactions with sand wave morphology, the range of current velocities, and available prey may also influence their distribution. Direct contact with sand wave habitats varied over diel periods, with more fish resting on the seafloor during daytime than at night. Social foraging, in the form of polarized groups of fish swimming in linear formations during crepuscular and daytime periods, was also observed. Sand wave habitats may provide shelter from current flows and mediate fish-prey interactions. ?? 2003 The Fisheries Society of the British Isles.

  8. Contrasting energy allocation strategies of two sympatric Merluccius species in an upwelling system.

    PubMed

    Rey, J; Fernandez-Peralta, L; Quintanilla, L F; Hidalgo, M; Presas, C; Salmeron, F; Puerto, M A

    2015-03-01

    This study investigated the somatic growth and energy allocation strategy of two sympatric hake species (Merluccius polli and Merluccius senegalensis), coexisting under the strong influence of the Mauritanian upwelling. The results revealed that ontogeny, bathymetry, geography and reproduction shaped the differences found between the condition dynamics of the two species. Aside from species-specific differences, individuals were observed in better condition in the northernmost area (more influenced by the permanent upwelling) and in the deepest waters, probably the most favourable habitat for Merluccius spp. Both species also displayed contrasting trade-offs in energy allocation probably due to the dissimilarity of their habitats, which favours the existence of divergent adaptive strategies in response to different ontogenic requirements. It was hypothesized that M. polli invests in mass and energy reserves while sacrificing growth, as larger sizes may not provide an ecological advantage in a deeper and more stable environment. Moreover, M. senegalensis capitalizes on a steady growth without major disruptions, enabling earlier spawning at the expense of a lower somatic mass, which is fitting to a less stable shallower environment. This study sheds new light on differences in the biological traits and life strategies of Merluccius spp., which permit their overlap in a complex upwelling system and may contribute to the long-lasting scientific-based management of these species.

  9. Anisakid parasites in commercial hake ceviche in southern Chile.

    PubMed

    Torres-Frenzel, Pablo; Torres, Patricio

    2014-07-01

    The objective of this research was to determine the occurrence of anisakid nematode larvae in hake ceviche sold in restaurants in Valdivia (39°48'S, 73°14'W) and Niebla (39°49'S, 73°22'W), Chile. Between August and November 2012, 78 portions of ceviche were collected (6 from each of the 13 restaurants that sell this product). Each portion was weighed and divided into approximately 30-g samples, which were placed in petri dishes with 0.15 M NaCl. All samples were manually shredded and then examined with a stereomicroscope. Muscles of 41 southern hake (Merluccius australis), a fish sold fresh in Valdivia, also were examined by candling to determine the presence of anisakid larvae. The presence of Pseudoterranova larvae in ceviche sold in Chile was identified for the first time. The pH of ceviche ranges from 4.1 to 4.8, which favors the presence of viable anisakid larvae that tolerate the acid pH similar to that found in the stomach of their mammalian host. No significant differences (P > 0.05) in the prevalence, mean abundance, and mean density of anisakid larvae in ceviche were found between localities. Larvae were detected in ceviche from 3 of 6 restaurants in Valdivia and 4 of 7 restaurants in Niebla. Of the 78 examined portions of ceviche, 21.8% had larvae. The prevalence of viable larvae was 16.7 and 7.1% in the examined portions from Valdivia and Niebla, respectively. In the 41 hake muscle samples from Valdivia, the prevalence (4.9%), mean abundance (0.1), and mean density (0.03) was the same for Pseudoterranova and Anisakis larvae. No inspection processes or pretreatments are currently in place for raw fish to achieve safe conditions for ceviche in restaurants from Valdivia and Niebla.

  10. Quantifying the predation on sardine and hake by cetaceans in the Atlantic waters of the Iberian peninsula

    NASA Astrophysics Data System (ADS)

    Begoña Santos, M.; Saavedra, Camilo; Pierce, Graham J.

    2014-08-01

    Construction of ecosystem models requires detailed information on trophic interactions which may not be readily available, especially for top predators such as cetaceans. Such information can also be useful to estimate natural mortality (M) for fish stock assessments and to evaluate the potential for competition between cetaceans and fisheries. In the present paper we provide estimates and confidence limits, taking into account sampling error, for consumption of fish by the four most common cetaceans along the Atlantic coast of the Iberian Peninsula, while highlighting the uncertainties and biases inherent in the information presently available on energy requirements, diet and population size. We estimated that common dolphins (Delphinus delphis) consume around 6800 (95% CI, 4871-9476) tons of sardine (Sardina pilchardus), 8800 (6195-12,647) tons of gadids, 1100 (721-1662) tons of hake (Merluccius merluccius) and 1900 (1222-2752) tons of scads (Trachurus sp.) annually. For striped dolphins (Stenella coeruleoalba), prey consumed were 900 (196-2661) tons of sardine, 6200 (3448-11,129) tons of gadids, 200 (11-504) tons of hake and 1600 (0-5318) tons of scads. Estimated amounts taken by harbour porpoises (Phocoena phocoena) and bottlenose dolphins (Tursiops truncatus) are much lower, reflecting their low abundance in the area. Cetacean predation on sardine represents 2-8% of the current M value, indicating that cetaceans probably have little influence on sardine population dynamics. For the southern hake stock, estimated average removal by cetaceans often exceeds M. While this may indicate that both M and the consumption estimates for hake require revision it also suggests that cetaceans could have a more significant impact on hake populations. Different approaches to estimation of energy requirements of cetaceans can result in figures that differ by at least a factor of 2. The lack of good estimates of field metabolic rate for most species probably represents the most

  11. Multi-sensor Oceanographic Correlations for Pacific Hake Acoustic Survey Improvement

    NASA Astrophysics Data System (ADS)

    Brozen, M.; Hillyer, N.; Holt, B.; Armstrong, E. M.

    2010-12-01

    North Pacific hake (Merluccius productus), the most abundant groundfish along the Pacific coast of northwestern America, are an essential source of income for the coastal region from southern California to British Columbia, Canada. However, hake abundance and distribution are highly variable among years, exhibiting variance in both the north-south and east-west distribution as seen in the results from biannual acoustic surveys. This project is part of a larger undertaking, ultimately focused on the prediction of hake distribution to improve the distribution of survey effort and precision of stock assessments in the future. Four remotely sensed oceanographic variables are examined as a first step in improving our understanding the relationship between the intensity of coastal upwelling and other ocean dynamics, and the north-south summer hake distribution. Sea surface height, wind vectors, chlorophyll - a concentrations, and sea surface temperature were acquired from several satellites, including AVHRR, SeaWifs, TOPEX/Poseidon, Jason-1, Jason-2, SSM/I, ASMR-E, and QuikScat. Data were aligned to the same spatial and temporal resolution, and these re-gridded data were then analyzed using empirical orthogonal functions (EOFs). EOFs were used as a spatio-temporally compact representation of the data and to reduce the co-variability of the multiple time series in the dataset. The EOF results were plotted and acoustic survey results were overlaid to understand differences between regions. Although this pilot project used data from only a single year (2007), it demonstrated a methodology for reducing dimensionality of linearly related satellite variables that can used in future applications, and provided insight into multi-dimensional ocean characteristics important for hake distribution.

  12. Dynamics and fishery of the Peruvian hake: Between nature and man

    NASA Astrophysics Data System (ADS)

    Guevara-Carrasco, Renato; Lleonart, Jordi

    Mean length in the catch of Peruvian hake ( Merluccius gayi peruanus) declined drastically by 8 cm in a few months in 1992. The 1991-93 El Niño event marked the beginning of changes in bottom environmental conditions, that along with other changes in the ecosystem, were the cause of the disappearance of large sized old hake from the traditional fishing grounds and the invasion of these areas by high concentrations of small sized young hake, traditionally distributed in the southern areas. A misinterpretation of this change gave an optimistic perception of the state of the stock, leading to a large increase of the fishing fleet and therefore to an increase of the fishing pressure on this resource. Catch increased quickly to very high levels in 1996, the fishery indicators of relative abundance remained stable, while global abundance of hake was diminishing. The resource responded to these natural variations of environment and to the intense fishing pressure with changes in some aspects of its biology and ecology. The most remarkable was the decrease of the length and age at first maturity that led to spawning by 1 year old (19 cm) individuals in a species whose observed longevity was 14 years. In 2002 a total and indefinite fishery closure was established by the Peruvian government and a technical commission for the hake recovery was created, which carried out continuous monitoring of the stock. After a closure of 20 months the indicators showed signs of recovery and the fishery was reopened in 2004. However, after an encouraging beginning during 2004 and the first quarter of 2005, neither abundance nor age structure had improved by the end of 2005, and in fact were deteriorating by the start of 2006. The survival of the age 2 and 3 groups was very low and few 4+ years old individuals were observed. Several factors working at different time scales have been proposed to explain the status of hake. The impact of the fishery, variations in the abiotic environment

  13. Trophic structure of the Peruvian marine ecosystem in 2000-2006: Insights on the effects of management scenarios for the hake fishery using the IBM trophic model Osmose

    NASA Astrophysics Data System (ADS)

    Marzloff, Martin; Shin, Yunne-Jai; Tam, Jorge; Travers, Morgane; Bertrand, Arnaud

    2009-01-01

    The individual-based trophic model Osmose is applied to the upwelling marine ecosystem off the coast of Peru. The dynamics and life cycle of eight major species of the Peruvian marine ecosystem are explicitly considered in the model. Reference simulations provide an overview of the trophic structure of the Peruvian ecosystem during the period 2000-2006. Results of model calibration and simulations are discussed in the light of current empirical knowledge on the trophic functioning of the Peruvian ecosystem and are compared to outputs obtained recently using the trophic model Ecopath. The impacts on the ecosystem of restoration plans for the depleted hake ( Merluccius gayi peruanus) population are explored through two management scenarios: a) a long term reduction of fishing effort targeting hake and b) a moratorium on the hake fishery. The simulations help better understand the recent failure of a 20 month hake moratorium and provide long-term strategic support to ecosystem-based management. Limits of our approach are discussed and recommendations are detailed for future developments of the Osmose model and ecosystem approach to fishery management in the Peruvian context.

  14. X-Ray crystal structure and molecular dynamics simulations of silver hake parvalbumin (Isoform B).

    PubMed Central

    Richardson, R. C.; King, N. M.; Harrington, D. J.; Sun, H.; Royer, W. E.; Nelson, D. J.

    2000-01-01

    Parvalbumins constitute a class of calcium-binding proteins characterized by the presence of several helix-loop-helix (EF-hand) motifs. In a previous study (Revett SP, King G, Shabanowitz J, Hunt DF, Hartman KL, Laue TM, Nelson DJ, 1997, Protein Sci 7:2397-2408), we presented the sequence of the major parvalbumin isoform from the silver hake (Merluccius bilinearis) and presented spectroscopic and structural information on the excised "EF-hand" portion of the protein. In this study, the X-ray crystal structure of the silver hake major parvalbumin has been determined to high resolution, in the frozen state, using the molecular replacement method with the carp parvalbumin structure as a starting model. The crystals are orthorhombic, space group C2221, with a = 75.7 A, b = 80.7 A, and c = 42.1 A. Data were collected from a single crystal grown in 15% glycerol, which served as a cryoprotectant for flash freezing at -188 degrees C. The structure refined to a conventional R-value of 21% (free R 25%) for observed reflections in the range 8 to 1.65 A [1 > 2sigma(I)]. The refined model includes an acetylated amino terminus, 108 residues (characteristic of a beta parvalbumin lineage), 2 calcium ions, and 114 water molecules per protein molecule. The resulting structure was used in molecular dynamics (MD) simulations focused primarily on the dynamics of the ligands coordinating the Ca2+ ions in the CD and EF sites. MD simulations were performed on both the fully Ca2+ loaded protein and on a Ca2+ deficient variant, with Ca2+ only in the CD site. There was substantial agreement between the MD and X-ray results in addressing the issue of mobility of key residues in the calcium-binding sites, especially with regard to the side chain of Ser55 in the CD site and Asp92 in the EF site. PMID:10739249

  15. X-Ray crystal structure and molecular dynamics simulations of silver hake parvalbumin (Isoform B).

    PubMed

    Richardson, R C; King, N M; Harrington, D J; Sun, H; Royer, W E; Nelson, D J

    2000-01-01

    Parvalbumins constitute a class of calcium-binding proteins characterized by the presence of several helix-loop-helix (EF-hand) motifs. In a previous study (Revett SP, King G, Shabanowitz J, Hunt DF, Hartman KL, Laue TM, Nelson DJ, 1997, Protein Sci 7:2397-2408), we presented the sequence of the major parvalbumin isoform from the silver hake (Merluccius bilinearis) and presented spectroscopic and structural information on the excised "EF-hand" portion of the protein. In this study, the X-ray crystal structure of the silver hake major parvalbumin has been determined to high resolution, in the frozen state, using the molecular replacement method with the carp parvalbumin structure as a starting model. The crystals are orthorhombic, space group C2221, with a = 75.7 A, b = 80.7 A, and c = 42.1 A. Data were collected from a single crystal grown in 15% glycerol, which served as a cryoprotectant for flash freezing at -188 degrees C. The structure refined to a conventional R-value of 21% (free R 25%) for observed reflections in the range 8 to 1.65 A [1 > 2sigma(I)]. The refined model includes an acetylated amino terminus, 108 residues (characteristic of a beta parvalbumin lineage), 2 calcium ions, and 114 water molecules per protein molecule. The resulting structure was used in molecular dynamics (MD) simulations focused primarily on the dynamics of the ligands coordinating the Ca2+ ions in the CD and EF sites. MD simulations were performed on both the fully Ca2+ loaded protein and on a Ca2+ deficient variant, with Ca2+ only in the CD site. There was substantial agreement between the MD and X-ray results in addressing the issue of mobility of key residues in the calcium-binding sites, especially with regard to the side chain of Ser55 in the CD site and Asp92 in the EF site.

  16. Novel Tools for Conservation Genomics: Comparing Two High-Throughput Approaches for SNP Discovery in the Transcriptome of the European Hake

    PubMed Central

    Milano, Ilaria; Babbucci, Massimiliano; Panitz, Frank; Ogden, Rob; Nielsen, Rasmus O.; Taylor, Martin I.; Helyar, Sarah J.; Carvalho, Gary R.; Espiñeira, Montserrat; Atanassova, Miroslava; Tinti, Fausto; Maes, Gregory E.; Patarnello, Tomaso; Bargelloni, Luca

    2011-01-01

    The growing accessibility to genomic resources using next-generation sequencing (NGS) technologies has revolutionized the application of molecular genetic tools to ecology and evolutionary studies in non-model organisms. Here we present the case study of the European hake (Merluccius merluccius), one of the most important demersal resources of European fisheries. Two sequencing platforms, the Roche 454 FLX (454) and the Illumina Genome Analyzer (GAII), were used for Single Nucleotide Polymorphisms (SNPs) discovery in the hake muscle transcriptome. De novo transcriptome assembly into unique contigs, annotation, and in silico SNP detection were carried out in parallel for 454 and GAII sequence data. High-throughput genotyping using the Illumina GoldenGate assay was performed for validating 1,536 putative SNPs. Validation results were analysed to compare the performances of 454 and GAII methods and to evaluate the role of several variables (e.g. sequencing depth, intron-exon structure, sequence quality and annotation). Despite well-known differences in sequence length and throughput, the two approaches showed similar assay conversion rates (approximately 43%) and percentages of polymorphic loci (67.5% and 63.3% for GAII and 454, respectively). Both NGS platforms therefore demonstrated to be suitable for large scale identification of SNPs in transcribed regions of non-model species, although the lack of a reference genome profoundly affects the genotyping success rate. The overall efficiency, however, can be improved using strict quality and filtering criteria for SNP selection (sequence quality, intron-exon structure, target region score). PMID:22132191

  17. [IMPACT OF SIX COOKING TECHNIQUES ON FATTY ACID COMPOSITION OF MARLIN (MAKAIRA NIGRICANS) AND HAKE (MERLUCCIUS PRODUCTUS)].

    PubMed

    Castro-González, María Isabel; Carrillo-Domínguez, Silvia

    2015-09-01

    Introducción: el consumo frecuente de pescado aporta beneficios a la salud por su contenido en ácidos grasos n-3. Generalmente se consume cocinado pero la cocción mejora o perjudica la concentración de ácidos grasos(AG), pues son susceptibles a oxidarse por las temperaturas y tiempos de cocción. Objetivos: analizar el efecto de seis técnicas de cocción sobre los lípidos totales (LT) y AG de marlín y merluza y seleccionar la que favorece una mejor conservación de AG de importancia para la salud. Métodos: se sometieron los filetes a diferentes técnicas de cocción: vapor (VA), empapelado papel-aluminio (EA), empapelado hoja-plátano (EP), horno-gas (HG), horno-microondas (HM) y sofrito (SF). Los AG se identificaron por cromatografía de gases/FID. Resultados y discusión: Marlín: el SF aumentó la concentración de LT y el HM la disminuyó. Estadísticamente, los AGS, AGP y EPA + DHA aumentaron con EA, los AGM disminuyeron con EP y aumentaron en el SF. Merluza: el SF aumentó la concentración en todos los grupos de AG, mientras que el VA la disminuyó. Por los valores de AGS, índices de aterogenicidad (IA), trombogenicidad (IT), susceptibilidad a la peroxidación y relación hipocolesterolémica/ hipercolesterolémica de los ácidos grasos (HH) encontrados, se sugiere que la merluza es un pescado con mayores beneficios para la salud, independientemente de la técnica que se aplique. Por su contenido en EPA + DHA el marlín parece ser una excelente opción si se cocina en papel aluminio. La técnica de sofrito en ambas especies disminuyó el IA, IT y aumentó significativamente la HH, sin embargo la relación n3/n6 disminuyó. La técnica menos conveniente para ambas especies resultó ser el VA.

  18. Argentine hemorrhagic fever vaccines.

    PubMed

    Ambrosio, Ana; Saavedra, Maria; Mariani, Mauricio; Gamboa, Graciela; Maiza, Andrea

    2011-06-01

    Argentine hemorrhagic fever (AHF), an acute disease caused by Junin virus (JUNV, Arenaviridae), has been an important issue to public health in Argentina since the early 1950s. The field rodent Calomys musculinus is JUNV natural reservoir and human disease is a consequence of contact with infected rodents. A steady extention of AHF endemic area is being observed since the first reports of the disease. Important achievements have been made in: (a) improvement of methods for the etiological diagnosis; (b) implementation and validation of therapeutical measures; (c) development of vaccines to protect against AHF. Reference is made to different research strategies used to obtain anti-AHF vaccines in the past and anti-arenaviral diseases in the present. Information is updated on features and field performance of Candid #1 vaccine, a live attenuted vaccine currently used to prevent AHF. This vaccine was developed through a joint international effort that envisioned it as an orphan drug. With transferred technology, Argentine government was committed to be Candid #1 manufacturer and to register this vaccine as a novel medical product under the Argentine regulatory authority. Candid #1 vaccine is the first one used to control an arenaviral hemorrhagic fever, the first live viral vaccine to be manufactured and registered in Argentina, reaching its target population through governmental effort.

  19. Argentine Space Assets.

    DTIC Science & Technology

    1997-09-01

    the Argentine Constitution [ Constitucion , 1994]. Its main objective is to contribute to the national defense in order to protect and warrant the...United States, the former Soviet Union, France, Japan, China, India, Luxembourg, Canada, Mexico , Thailand, Brazil, Turkey, Germany, Israel, Sweden...MCI-i1 MCINews Corp. 98 BSS 17.3-1 7.8 12.2-1 2.7 TBD 110W MCI-2 MCI/News Corp. 99 BSS 17.3-1 7.8 12.2-12.7 TBD 110W Megasat-i Mexico TBD ESS 28.35-30

  20. Acoustical Scattering, Propagation, and Attenuation Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake

    DTIC Science & Technology

    2011-09-30

    Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake Kelly J. Benoit-Bird College of Oceanic and Atmospheric Sciences 104...Attenuation Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...have successfully recruited graduate students that will conduct thesis research as part of this project. RESULTS Both hake and Humboldt squid

  1. [Immigration policies in Argentine law].

    PubMed

    Vichich, N P

    1988-12-01

    This paper analyzes contents of Argentine immigration laws in different periods of Argentine history and refers those contents to the State which enforced the corresponding immigration policies and to the socioeconomic structure they support. The Argentine constitution (1852) and subsequent immigration laws define 2 principal guidelines in population and immigration policies: 1) from 1852 until 1955 immigrants are seen as a part of socioeconomic growth, and 2) after 1955 the theory of national security prevails over considerations of an economic nature. With the return to democracy it should be possible to redefine immigration policies considering the country's demographic requirements and the migrants' own needs.

  2. Argentine tango in Parkinson disease.

    PubMed

    2016-10-28

    This article reports on a meta-analysis of 13 studies of the effects of Argentine tango (AT) as a music-based movement therapy for people with Parkinson's disease (PD). Nine studies involved randomised controlled trials.

  3. Acoustical Scattering, Propagation, and Attenuation Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake

    DTIC Science & Technology

    2015-09-30

    schools of squid and hake, we will combine information from field surveys of aggregations with measurements of the biological and physical habitat ...measurements, and predictions resulting from this work will be directly applicable to naval operations within the habitat of hake and squid and will extend

  4. Contemporary Argentine Cinema during Neoliberalism

    ERIC Educational Resources Information Center

    Rocha, Carolina

    2009-01-01

    In this article I analyze contemporary Argentine cinematic production assessing the impact of Law 24,377 that was implemented in 1995 and that provided much-needed funds for national productions. By looking at film production and consumption, the emergence of young filmmakers and the performance of both commercial films and those belonging to the…

  5. Contemporary Argentine Cinema during Neoliberalism

    ERIC Educational Resources Information Center

    Rocha, Carolina

    2009-01-01

    In this article I analyze contemporary Argentine cinematic production assessing the impact of Law 24,377 that was implemented in 1995 and that provided much-needed funds for national productions. By looking at film production and consumption, the emergence of young filmmakers and the performance of both commercial films and those belonging to the…

  6. Acoustical Scattering, Propagation, and Attenuation Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake

    DTIC Science & Technology

    2012-09-30

    Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake Kelly J. Benoit-Bird College of Oceanic and Atmospheric Sciences 104...Abundant Pacific Schooling Species: Humboldt Squid and Hake 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...with maximum lengths of up to 90 cm. A more recent immigrant to these waters, is the similarly sized and highly abundant jumbo or Humboldt squid

  7. Pacific Hake Characteristics Affecting the Conduct of an Acoustic Clutter Experiment off the West Coast of the United States

    DTIC Science & Technology

    2012-07-04

    the assessment process. Echo sounder /trawl surveys of hake have been conducted by the National Marine Fisheries Service (NMFS) since 1977 to assess...3] There will be an NMFS hake survey in 2012. [20] The echo sounder /trawl method uses echo sounders to measure the total acoustic backscattering...NMFS echo sounder /trawl surveys have focused on fish age two or greater. Age-1 hake are generally more southerly and closer to shore than adults and

  8. Marine fronts are important fishing areas for demersal species at the Argentine Sea (Southwest Atlantic Ocean)

    NASA Astrophysics Data System (ADS)

    Alemany, Daniela; Acha, Eduardo M.; Iribarne, Oscar O.

    2014-03-01

    The high primary and secondary production associated with frontal systems attract a diversity of organisms due to high prey availability; this is why a strong relationship between fronts and pelagic fisheries has been shown worldwide. In the Argentine Sea, demersal resources are the most important, both in economical and in ecological sense; so we hypothesize that fronts are also preferred fishing areas for demersal resources. We evaluated the relationship between spatial distribution of fishing effort and oceanographic fronts, analyzing three of the most important frontal systems located in the Argentine Sea: the shelf-break front, the southern Patagonia front and the mid-shelf front. Individual vessel satellite monitoring system data (VMS; grouped by fleet type: ice-trawlers, freezer-trawlers and jigging fleet) were studied and fishing events were identified. Fishing events per area were used as a proxy of fishing effort and its spatial distribution by fleet type was visualized and analyzed with Geographic Information Systems. Oceanographic fronts were defined using polygons based on satellite chlorophyll amplitude values, and the percentage of fishing events within each polygon was calculated. Results showed a positive association between fronts and fishing activities of the different fleets, which suggests the aggregation of target species in these zones. The coupling of the freezer-trawler and jigging fleets (that operate on lower trophic level species; Macruronus magellanicus and Illex argentinus respectively) with fronts was higher than the ice-trawler fleet, targeting species of higher trophic level (Merluccius hubbsi). Marine fronts represent important fishing areas, even for demersal resources, as the distribution of fishing fleets and fishing effort are positively associated with frontal zones.

  9. Selection of the Argentine indicator region

    NASA Technical Reports Server (NTRS)

    Ramirez, C. J.; Reed, C. R. (Principal Investigator)

    1982-01-01

    Determined from available Argentine crop statistics, selection of the Indicator Region was based on the highest wheat, corn, and soybean producing provinces, which were: Buenos Aires, Cordoba, Entre Rios, and Santa Fe. Each province in Argentina was examined for the availability of LANDSAT data; area, yield and production statistics; crop calendars; and other ancillary data. The Argentine Indicator Region is described.

  10. [Microbiological controls and control points in a hake fillets manufacturing process for exportation].

    PubMed

    Estevao Belchior, S; Pucci, O H

    2000-06-01

    Indicator and foodborne pathogen microorganisms in the "for export" hake fillets manufacturing were investigated in this study. Critical control points were identified and prevention activities and control were proposed during seafood elaboration process. 45 samples of hake from sequential processing operation stages, 15 ice samples and 12 water samples from utensil washing, were collected. The samples were analyzed for their content of aerobic mesophilic bacteria, psychrotrophic bacteria, enterobacteria, total and fecal coliform bacteria, Staphylococcus aureus and the presence of Escherichia coli, Salmonella and Shigella. The analysis of the samples collected from the factory revealed that the amounts of aerobic mesophile bacteria increased during manual filleting and packaging, in comparison with raw material. Psychrotrophic bacteria were the predominant microorganisms, specially in hake samples. In addition, high levels of enterobacteria, which do not occur normally in fish, were detected in raw hake samples. Staphylococcus aureus, Escherichia coli, Salmonella and Shigella, were not isolated from any samples in this study. The goal of this work is to establish microbiological risks in the hake fillets manufacturing process and, therefore to make possible corrective and control actions to assure the quality and safety of seafood.

  11. Trap-mulching Argentine ants.

    PubMed

    Silverman, Jules; Sorenson, Clyde E; Waldvogel, Michael G

    2006-10-01

    Argentine ant, Linepithema humile (Mayr), management is constrained, in large part, by polydomy where nestmates are distributed extensively across urban landscapes, particularly within mulch. Management with trap-mulching is a novel approach derived from trap-cropping where ants are repelled from a broad domain of nest sites to smaller defined areas, which are subsequently treated with insecticide. This concept was field-tested with mulch surrounding ornamental trees replaced with a narrow band of pine (Pinus spp.) needle mulch (trap) within a much larger patch of repellent aromatic cedar (Juniperus spp.) mulch. After ants reestablished around the trees, the pine needle mulch band was treated with 0.06% fipronil (Termidor). Poor results were obtained when the trap extended from the tree trunk to the edge of the mulched area. When the trap was applied as a circular band around the tree trunk reductions in the number of foraging ants were recorded through 14 d compared with an untreated mulch control, but not for longer periods. Reductions in the number of ant nests within mulch were no different between the trap mulch and any of the other treatments. We conclude that trap-mulching offers limited benefits, and that successful management of Argentine ants will require implementation of complementary or perhaps alternative strategies.

  12. Prediction of silver hake distribution on the Northeast U.S. shelf based on the Gulf Stream path index

    NASA Astrophysics Data System (ADS)

    Davis, Xujing Jia; Joyce, Terrence M.; Kwon, Young-Oh

    2017-04-01

    Over the past 40 years, the distribution of silver hake on the Northeast U.S. shelf is found to be significantly correlated with changes in the latitude of Gulf Stream path. The correlation coefficient between the fall Gulf Stream position and the center of biomass of spring silver hake reaches 0.75 when the Gulf Stream leads the silver hake for 6 months. Based on this lead-lag relationship and low-frequency variability of Gulf Stream position with a dominant periodicity of 9-10 years, the Gulf Stream position is used as a predictor for the center of biomass of silver hake in linear autoregressive (AR) models. The goal of this study is then to optimize the AR model for the prediction of silver hake based on the observed changes in Gulf Stream position. Fall Gulf Stream position is first predicted out to 5 years using a 5th order AR model and the observed Gulf Stream position in preceding years. An optimization process is proposed to choose best AR coefficients based on a newly proposed combined skill parameter. Furthermore, the robustness of our Gulf Stream prediction is verified by comparing the observed Gulf Stream path index data from 2009 to 2012, which are not used for optimizing the AR model, and the predicted Gulf Stream path values for the same time period. We then use this predicted Gulf Stream position to further predict the center of biomass of silver hake in the subsequent spring. Three different methods are used and compared for the silver hake prediction. The predicted silver hake time series can explain as much as 69% of the variance of the observation for the 1st year prediction and 41% for the 5th year prediction. Our results indicate that including Gulf Stream as a predictor produces better prediction skills of silver hake center of biomass than the AR model prediction solely based on the observed silver hake time series.

  13. Early intrauterine embryonic development of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost Merluccius merluccius (L., 1758) (Gadiformes: Merlucciidae).

    PubMed

    Swiderski, Zdzisław; Miquel, Jordi; Torres, Jordi; Delgado, Eulàlia

    2013-07-01

    The early intrauterine embryonic development of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost Merluccius merluccius (L., 1758), was studied by means of light (LM) and transmission electron microscopy (TEM). Contrary to the generic diagnosis given in the CABI Keys to the cestode parasites of vertebrates, the eggs of C. crassiceps, the type of species of Clestobothrium Lühe, 1899, are operculate and embryonated. Our LM and TEM results provide direct evidence that an operculum is present and that the eggs exhibit various stages of intrauterine embryonic development, and in fact represent a good example of early ovoviviparity. The intrauterine eggs of this species are polylecithal and contain numerous vitellocytes, generally ∼30, which are pushed to the periphery and remain close to the eggshell, whereas the dividing zygote and later the early embryo remain in the egg centre. During early intrauterine embryonic development, several cleavage divisions take place, which result in the formation of three types of blastomeres, i.e. macro-, meso- and micromeres. These can be readily differentiated at the TEM level, not only by their size, but also by the ultrastructural characteristics of their nuclei and cytoplasmic organelles. The total number of blastomeres in these early embryos, enclosed within the electron-dense eggshells, can be up to ∼20 cells of various sizes and characteristics. Mitotic divisions of early blastomeres were frequently observed at both LM and TEM levels. Simultaneously with the mitotic cleavage divisions leading to blastomere multiplication and their rapid differentiation, there is also a deterioration of some blastomeres, mainly micromeres. A similar degeneration of vitellocytes begins even earlier. Both processes show a progressive degeneration of both vitellocytes and micromeres, and are good examples of apoptosis, a process that provides nutritive substances, including lipids, for the

  14. Spermiogenesis and spermatozoon ultrastructure of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (Gadiformes: Merlucciidae).

    PubMed

    Marigo, Adji Mama; Delgado, Eulàlia; Torres, Jordi; Bâ, Cheikh Tidiane; Miquel, Jordi

    2012-01-01

    Spermiogenesis and the ultrastructure of the spermatozoon of the bothriocephalidean cestode Clestobothrium crassiceps (Rudolphi, 1819), a parasite of the teleost fish Merluccius merluccius (Linnaeus, 1758), have been studied by means of transmission electron microscopy. Spermiogenesis involves firstly the formation of a differentiation zone. It is characterized by the presence of two centrioles associated with striated rootlets, an intercentriolar body and an electron-dense material in the apical region of this zone. Later, two flagella develop from the centrioles, growing orthogonally in relation to the median cytoplasmic process. Flagella then undergo a rotation of 90° until they become parallel to the median cytoplasmic process, followed by the proximodistal fusion of the flagella with the median cytoplasmic process. The nucleus elongates and afterwards it migrates along the spermatid body. Spermiogenesis finishes with the appearance of the apical cone surrounded by the single helical crested body at the base of the spermatid. Finally, the narrowing of the ring of arched membranes detaches the fully formed spermatozoon. The mature spermatozoon of C. crassiceps is filiform and contains two axonemes of the 9 + "1" trepaxonematan pattern, a parallel nucleus, parallel cortical microtubules, and electron-dense granules of glycogen. The anterior extremity of the gamete exhibits a short electron-dense apical cone and one crested body, which turns once around the sperm cell. The first axoneme is surrounded by a ring of thick cortical microtubules that persist until the appearance of the second axoneme. Later, these thick cortical microtubules disappear and thus, the mature spermatozoon exhibits two bundles of thin cortical microtubules. The posterior extremity of the male gamete presents only the nucleus. Results are discussed and compared particularly with the available ultrastructural data on the former "pseudophyllideans". Two differences can be established

  15. 77 FR 48915 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; White Hake Trimester...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-15

    ... all common pool vessels fishing with trawl gear, sink gillnet gear, and longline/hook gear. The White... White Hake Trimester Total Allowable Catch (TAC) Area to all common pool vessels fishing with trawl gear, sink gillnet gear, or longline/hook gear for the remainder of Trimester 1, through August 31, 2012...

  16. Merluccius tasmanicus Matallanas & Lloris 2006 is a junior synonym of M. australis (Hutton 1872) (Gadiformes: Merluciidae) based on morphological and molecular data.

    PubMed

    Antoni, Mariana Y Deli; Delpiani, Sergio M; Stewart, Andrew L; González-Castro, Mariano; De Astarloa, Juan M Díaz

    2015-05-07

    The high intraspecific variation among and the conservative external morphology of Merluccius spp. have resulted in serious identification difficulties. Four hundred and twenty fresh and preserved specimens of Merluccius were analyzed, including the type series of Merluccius australis, M. tasmanicus and M. hubbsi; specimens of M. hubbsi from Argentina, Brazil and Uruguay, and individuals of M. australis from Argentina and New Zealand were examined. The nomenclatural status of the type specimens of M. australis is discussed and the designation of a lectotype and a paralectotype is proposed. The comparative study of morphology, meristic, traditional and landmark-based morphometry, both external and internal, and through DNA-based Barcoding molecular tools demonstrates that Merluccius tasmanicus is a junior synonym of Merluccius australis. Meristic and morphometric characters of types of M. tasmanicus completely overlap those of M. australis, whereas M. hubbsi show fewer scales along the lateral line, total vertebrae, second dorsal and anal-fin rays. A trend of a longer snout and wider head in M. australis and M. tasmanicus, and larger eyes and longer pelvic fins, in M. hubbsi was observed. While discriminant characters were found in the internal elements (hyomandibula, urohyal and sagitta otolith) between M. hubbsi and M. australis, none were observed between M. australis and those reported for M. tasmanicus. DNA barcoding analyses found no evidence of the existence of other species of Merluccius besides M. hubbsi and M. australis.

  17. Treatment of Argentine hemorrhagic fever.

    PubMed

    Enria, Delia A; Briggiler, Ana M; Sánchez, Zaida

    2008-04-01

    Argentine hemorrhagic fever (AHF) is a rodent-borne illness caused by the arenavirus Junin that is endemic to the humid pampas of Argentina. AHF has had significant morbidity since its emergence in the 1950s, with a case-fatality rate of the illness without treatment between 15% and 30%. The use of a live attenuated vaccine has markedly reduced the incidence of AHF. Present specific therapy involves the transfusion of immune plasma in defined doses of neutralizing antibodies during the prodromal phase of illness. However, alternative forms of treatment are called for due to current difficulties in early detection of AHF, related to its decrease in incidence, troubles in maintaining adequate stocks of immune plasma, and the absence of effective therapies for severely ill patients that progress to a neurologic-hemorrhagic phase. Ribavirin might be a substitute for immune plasma, provided that the supply is guaranteed. Immune immunoglobulin or monoclonal antibodies should also be considered. New therapeutic options such as those being developed for systemic inflammatory syndromes should also be valuated in severe forms of AHF.

  18. Antiviral treatment of Argentine hemorrhagic fever.

    PubMed

    Enria, D A; Maiztegui, J I

    1994-01-01

    Argentine hemorrhagic fever is a systemic viral disease caused by Junin virus, with a mortality of 15-30% in untreated individuals. Current specific therapy is highly effective in reducing mortality, and consists of the early administration of immune plasma in defined doses of specific neutralizing antibodies per kg of body weight. However, several reasons suggest the need to investigate alternative therapies. Ribavirin, a broad spectrum antiviral agent, is effective in the treatment of other viral hemorrhagic fevers, and the studies done with Junin virus infections to date indicate that this drug may also have a beneficial effect in Argentine hemorrhagic fever.

  19. Terpenoids and bibenzyls from three Argentine liverworts.

    PubMed

    Nagashima, Fumihiro; Asakawa, Yoshinori

    2011-12-16

    A new rosane diterpenoid, 3a-hydroxy-5,15-rosadien-11-one (3), was isolated, together with a known rosane diterpenoid, 5,15-rosadiene-3,11-dione (4), and an aromadendrane sesquiterpenoid, ent-cyclocolorenone (5), from the Et(2)O extract of an unidentified Argentine liverwort Anastrophyllum species. Moreover, four known sesquiterpene lactones 6-9 and two known bibenzyls 10, 11 were isolated from the Et(2)O extracts of Argentine Frullania brasiliensis and Radula voluta, respectively. The structures of compounds 3-11 were determined by the use of NMR techniques.

  20. Radiation Studies with Argentine Ion Exchange Material

    SciTech Connect

    Crawford, C.L.

    2002-06-28

    A recent technology exchange between Argentina Nuclear Energy Commission (CNEA) and the US Department of Energy involved vitrification studies of ion exchange resins. Details of the spent ion exchange resins currently stored at two Argentine nuclear power plants, Atucha I and Embalse, have been presented in earlier reports. The present study examines irradiation of simulant samples of ion exchange resins.

  1. Juvenile hake predation on Myctophidae and Sternoptychidae: Quantifying an energy transfer between mesopelagic and neritic communities

    NASA Astrophysics Data System (ADS)

    Modica, Larissa; Cartes, Joan E.; Velasco, Francisco; Bozzano, Anna

    2015-01-01

    Seasonal study of the diet and food consumption of juvenile hake has been carried out in the Central Mediterranean Sea (Southern Tyrrhenian Sea). Fish were the most important food resource in terms of weight (ca. 70%). Among the fish, Myctophidae and Sternoptychidae, which are usually distributed deeper than juvenile hake, are most important. During summer, Ceratoscopelus maderensis constituted up to 21% of weight of all prey, and Maurolicus muelleri represented almost 10%. During autumn M. muelleri became the most important food resource. The way in which these more deeply distributed prey enter shallower food webs relates to the daily vertical migrations of lanternfish. In upper water column strata at night or near dawn they become prey of the juvenile hake. Considering that trophic energy flows primarily downward, in the direction of the productivity gradient, the observed flow of energy from deep strata into epipelagic layers could be considered an inverse energy transfer. Daily food consumption of juvenile hake ranged between 4.11 and 4.72% of the body wet-weight (BWW). The application of a square-root model allowed calculation of the fraction of this consumption derived by ingestion of the more deeply distributed mesopelagic fish. Between 11.6% and 17.8% of food consumption was sustained by this energy flow. Such information is useful for understanding the interaction between communities distributed in different depth ranges and to reinforce the idea that marine communities are open systems in which migratory movements can dramatically change the assumptions and results of mass-balance models.

  2. Out of the Celtic cradle: The genetic signature of European hake connectivity in South-western Europe

    NASA Astrophysics Data System (ADS)

    Pita, Alfonso; Pérez, Montse; Balado, Miguel; Presa, Pablo

    2014-10-01

    Population genetic data of marine genetic resources add up to establish their pattern of connectivity. Such pattern determines the choice of a suitable management strategy to those resources in space and time. This study addresses the pattern of connectivity among European hake grounds upon the largest sampling effort so far developed in this species. Bayesian inference made on multilocus genotypic data provides evidence that a large genetic connectivity exists among Atlantic grounds and is mediated by significant migration rates stepping up from the Celtic Sea towards its adjacent Atlantic grounds. Therefore, the spawning biomass of the northern hake population could play a crucial role at ensuring the sustainability of southern hake fish grounds. The deepest restriction to gene flow was observed at the easternmost side of the Alboran Sea what suggests that the Almeria-Oran Oceanographic Front is an effective barrier keeping apart the two major gene pools so far shown in this species. A molecular clock calibrated for cytochrome b sequences of fishes and applied to the divergence between hake pools (0.3%) suggests that the Atlantic-Mediterranean population split might date back to the Middle Pleistocene (150,000 years BP). Complementarily, Bayesian treatments of multilocus genotypes indicate that such barrier to gene flow remains active nowadays. This study shows the upmost interest of future integrative efforts to incorporate population genetic data into current assessment practices, in order to better manage European hake populations and make its exploitation sustainable.

  3. Malvinas: the Argentine Perspective of the Falkland’s Conflict

    DTIC Science & Technology

    2010-05-01

    Guerra de las Malvinas:Historical background of the Malvinas Conflict. (Buenos Aires-Argentina: Circulo Militar, 1989), 121. 3 Argentine Army...the Argentine Air Force among others. Other important Argentine sources in general are: Carlos Landaburu’s La Guerra de las Malvinas : Historical... Guerra de las Malvinas : Historical background of the Malvinas Conflict (Buenos Aires-Argentina: Circulo Militar, 1988), 21. Port Egmond was a part of

  4. 75 FR 53731 - Culturally Significant Objects Imported for Exhibition Determinations: “Contemporary Argentine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-01

    ... for Exhibition Determinations: ``Contemporary Argentine Masterworks'' SUMMARY: Notice is hereby given... hereby determine that the objects to be included in the exhibition ``Contemporary Argentine...

  5. SAC-B, Argentine scientific satellite

    NASA Technical Reports Server (NTRS)

    Gulich, J. M.; White, C.

    1994-01-01

    The project and the missions of the Argentine scientific satellite, SAC-B, are summarized. SAC-B is an international cooperative project between NASA and the Secretariat of State of Science and Technology of the Argentine Republic. The objective of SAC-B is to advance the study of solar physics and astrophysics through the examination of solar flares, gamma ray burst sources and the diffuse soft X-ray cosmic background. The scientific payload comprises an instrument to measure the temporal evolution of X-ray emissions from solar flares as well as nonsolar gamma ray bursts, a combined soft X-ray and gamma ray burst detector, a diffuse X-ray background detector, and an energetic neutral atoms detector.

  6. SAC-B, Argentine scientific satellite

    NASA Technical Reports Server (NTRS)

    Gulich, J. M.; White, C.

    1994-01-01

    The project and the missions of the Argentine scientific satellite, SAC-B, are summarized. SAC-B is an international cooperative project between NASA and the Secretariat of State of Science and Technology of the Argentine Republic. The objective of SAC-B is to advance the study of solar physics and astrophysics through the examination of solar flares, gamma ray burst sources and the diffuse soft X-ray cosmic background. The scientific payload comprises an instrument to measure the temporal evolution of X-ray emissions from solar flares as well as nonsolar gamma ray bursts, a combined soft X-ray and gamma ray burst detector, a diffuse X-ray background detector, and an energetic neutral atoms detector.

  7. Chlorofluorocarbon distributions in the deep Argentine Basin

    SciTech Connect

    Warner, M.J. ); Weiss, R.F. ); Smethie, W.M. Jr. )

    1990-01-09

    The seawater concentrations of the chlorofluorocarbons (CFCs) F-11 and F-12 were measured in the Argentine Basin during the Abyssal Boundary Current Studies (1986) and the South Atlantic Ventilation Experiment (1988-89) expeditions. In most regions of the basin, the CFC concentrations are above the detection limit (0.015 pmol/kg) in the entire water column. The main features of the F-11 and F-12 profiles in the deep waters of the Argentine Basin are concentration mixima at depths of 2 to 3 km and generally increasing concentrations towards the bottom. The mid-depth CFC minima are associated with the salinity maximum of Circumpolar Deep Water (CDW). The higher CFC concentrations at the seafloor are correlated with the colder temperatures of Antarctic Bottom Water (AABW). The CFC concentrations in AABW are highest on the eastern portion of the basin along 47[degrees]S and along the southern and western boundaries. These distributions are consistent with a separation of the inflowing AABW into a cyclonic gyre in the eastern portion of the basin and a western boundary current which carries a detectable CFC singal as far noth as 17[degrees]S. Between CDW and AABW, there are local CFC maxima and minima which are not associated with extrema in other hydrographic properties. The local minima are found on a mean density of 46.07 [sigma][sub 4], which is the upper bound of the water entering the Argentine Basin from the Weddell Sea (Reid, Deep-Sea Res., 1989 submitted). The local CFC maxima are found at about the 46.00 [sigma][sub 4] isopycnal surface. Water of this density apparently is of circumpolar origin. The presence of these local CFC extrema in this density range carries information on the time-dependent vertical mixing in the deep Argentine Basin.

  8. High level of mislabeling in Spanish and Greek hake markets suggests the fraudulent introduction of African species.

    PubMed

    Garcia-Vazquez, Eva; Perez, Juliana; Martinez, Jose L; Pardiñas, Antonio F; Lopez, Belen; Karaiskou, Nikoletta; Casa, Mary F; Machado-Schiaffino, Gonzalo; Triantafyllidis, Alexander

    2011-01-26

    DNA analysis of hake products commercialized in southern European (Spanish and Greek) market chains have demonstrated more than 30% mislabeling, on the basis of species substitution. Tails and fillets were more mislabeled than other products, such as slices and whole pieces. African species were substitute species for products labeled as American and European species, and we suggest it is a case of deliberate economically profitable mislabeling because real market prices of European and American hake products are higher than those of African in Spanish market chains. The presented results suggest fraud detection that disadvantages African producers. Government-mandated genetic surveys of commercial hakes and the use of subsequent statements of fair trade on labels of seafood products could help to reduce fraud levels in a global market of increasingly conscious consumers sensitive to ethical issues.

  9. Hydrocarbon prospectivity of the Argentine Continental Slope

    SciTech Connect

    Light, M.P.R.; Keeley M.L.; Maslanyj, M.P.; Urien, C.M.; Hoggs, S.L.

    1993-02-01

    A rift basin containing stratigraphic and structural closures is developed along the Argentine slope over a distance of some 1000 km and area of 50,000 km[sup 2] in potentially exploitable water depths of 200 to 1500 m. No wells exist on this part of the continental margin. Rifting began during the Late Triassic/Jurassic and ended in Early Cretaceous. The first marine seaways flooded the Rift alluvial plains and lake. In Hauterian-Barrenian time, low circulation marine conditions with oxygen deficiency prevailed up to Rio Grande/Walvis Ridge flooding in part the coastal pull-apart basins. A major marine transgression in the Maastrichtian formed a widespread seal over the entire shelf and slope area. Four play types were identified: (1) a major north-east trending elongate delta system sourced inland from the San Julien (N. Malvinas) Basin and deposited on the southern Patagonian shelf and rise, (2) reworked deltaic barrier sands accumulated along the crest of the Outer Basement Ridge, (3) The Outer Basement Ridge, a major structural closure 400 km long, and (4) a series of margin-parallel rift systems in the offshore region between the 200 m and 1500 m isobaths. Regional seismic data and geological correlations suggest that oil prone source rocks are likely in the Middle and Upper Jurassic and Cretaceous formations. Source rocks are probably mature east and west of the Outer Basement Ridge and in the easterndepocenter of the Colorado Basin. Eastward migration from Jurassic age lacustrine source rocks in the Colorado Basin may have charged traps along the crest of the Outer Basement Ridge. Westward directed migration from deeply buried Aptian age marine source rocks in the Atlantic basins has probably charged prospective stratigraphic and structural traps in a suite of coast-parallel grabens developed on the Argentine continental shelf and slope. The Argentine offshore region, therefore, offers significant encouragement as a productive hydrocarbon province.

  10. Characterization of a helix-loop-helix (EF hand) motif of silver hake parvalbumin isoform B.

    PubMed Central

    Revett, S. P.; King, G.; Shabanowitz, J.; Hunt, D. F.; Hartman, K. L.; Laue, T. M.; Nelson, D. J.

    1997-01-01

    Parvalbumins are a class of calcium-binding proteins characterized by the presence of several helix-loop-helix (EF-hand) motifs. It is suspected that these proteins evolved via intragene duplication from a single EF-hand. Silver hake parvalbumin (SHPV) consists of three EF-type helix-loop-helix regions, two of which have the ability to bind calcium. The three helix-loop-helix motifs are designated AB, CD, and EF, respectively. In this study, native silver hake parvalbumin isoform B (SHPV-B) has been sequenced by mass spectrometry. The sequence indicates that this parvalbumin is a beta-lineage parvalbumin. SHPV-B was cleaved into two major fragments, consisting of the ABCD and EF regions of the native protein. The 33-amino acid EF fragment (residues 76-108), containing one of the calcium ion binding sites in native SHPV-B, has been isolated and studied for its structural characteristics, ability to bind divalent and trivalent cations, and for its propensity to undergo metal ion-induced self-association. The presence of Ca2+ does not induce significant secondary structure in the EF fragment. However, NMR and CD results indicate significant secondary structure promotion in the EF fragment in the presence of the higher charge-density trivalent cations. Sedimentation equilibrium analysis results show that the EF fragment exists in a monomer-dimer equilibrium when complexed with La3+. PMID:9385642

  11. Characterization of a helix-loop-helix (EF hand) motif of silver hake parvalbumin isoform B.

    PubMed

    Revett, S P; King, G; Shabanowitz, J; Hunt, D F; Hartman, K L; Laue, T M; Nelson, D J

    1997-11-01

    Parvalbumins are a class of calcium-binding proteins characterized by the presence of several helix-loop-helix (EF-hand) motifs. It is suspected that these proteins evolved via intragene duplication from a single EF-hand. Silver hake parvalbumin (SHPV) consists of three EF-type helix-loop-helix regions, two of which have the ability to bind calcium. The three helix-loop-helix motifs are designated AB, CD, and EF, respectively. In this study, native silver hake parvalbumin isoform B (SHPV-B) has been sequenced by mass spectrometry. The sequence indicates that this parvalbumin is a beta-lineage parvalbumin. SHPV-B was cleaved into two major fragments, consisting of the ABCD and EF regions of the native protein. The 33-amino acid EF fragment (residues 76-108), containing one of the calcium ion binding sites in native SHPV-B, has been isolated and studied for its structural characteristics, ability to bind divalent and trivalent cations, and for its propensity to undergo metal ion-induced self-association. The presence of Ca2+ does not induce significant secondary structure in the EF fragment. However, NMR and CD results indicate significant secondary structure promotion in the EF fragment in the presence of the higher charge-density trivalent cations. Sedimentation equilibrium analysis results show that the EF fragment exists in a monomer-dimer equilibrium when complexed with La3+.

  12. The Argentine Professorate: Occupational Insecurity and Political Interference

    ERIC Educational Resources Information Center

    Socolow, Daniel J.

    1973-01-01

    This article attempts to treat the sensitive issue of occupational insecurity in the Argentine university system and to suggest its effect on the future development of the academic community in Argentina. (Author)

  13. Exploration of Possible Astroblemes in the Argentine Puna

    NASA Astrophysics Data System (ADS)

    Acevedo, R. D.; Alonso, R.; Rocca, M.; Klajnik, K.; Tálamo, E.

    2014-09-01

    Potential three new astrobleme sites have been detected by remote sensors and checked in situ in Argentine Puna: an elevated plateau that it has remained stable and invariable across long geological periods.

  14. A Descriptive Study of the Argentine Music Teacher.

    ERIC Educational Resources Information Center

    Gratzer, Dina; Sima, Marta

    1987-01-01

    Reports on a research study which examined the professional status of music teachers in Argentina. Describes various areas of concern for Argentine music teachers including general training, the workplace, teacher training and musical activities. (RKM)

  15. Where and how Argentine ant (Linepithema humile) spreads in Corsica?

    PubMed

    Blight, Olivier; Orgeas, Jérôme; Renucci, Marielle; Tirard, Alain; Provost, Erick

    2009-08-01

    The Argentine ant, Linepithema humile (Dolichoderinae), is one of the most widespread invasive ant species in the world. When established in optimal habitat, this species usually excludes most other local ants and can heavily impact other arthropods as well. Although Argentine ants have been present in southern Europe for more than 100 years, they were first noted in Corsica, a French Mediterranean island, in 1957 in only one urban station. In this study, we aimed to map precisely their geographical distribution in Corsica and to quantify their presence by using an infestation index. We recorded changes in the distribution of Argentine ants in Corsica over the past decade. Argentine ants appeared to be well established within their introduced range and spreading along the Corsican coasts principally through Human-mediated jump-dispersal but not homogenously.

  16. Developmental instability as an indicator of natural stress on the Pacific Hake (Merlussius productus)

    USGS Publications Warehouse

    Alados, C.L.; Escos, J.; Emlen, J.M.

    1994-01-01

    Developmental lnstability (DI) has been proposed as an inexpensive, quickly applied, and sensitive indicator of stress that can be utilized in early warning and in monitoring anthropogenic impacts on fish and other animals and plants. A problem arises, however, to the extent that natural stressors confound the effects of human-induced disturbances. Our objective in this work was to investigate whether a natural stressor, in the form of EI Nino conditions, contributed to DI in the Pacific hake. Right-left (fluctuating> asymmetry of otolith length, width, growth rate, and weight, as well as right-left otolith shape differences, were used as measures of DI. Results show that indeed EI Nino disrupts development, indicating stress. This outcome suggests that DI, as an early warning and monitoring tool for stress, must be used with caution.

  17. Determination of the Geographical Origin of All Commercial Hake Species by Stable Isotope Ratio (SIR) Analysis.

    PubMed

    Carrera, Mónica; Gallardo, José M

    2017-02-08

    The determination of the geographical origin of food products is relevant to comply with the legal regulations of traceability, to avoid food fraud, and to guarantee food quality and safety to the consumers. For these reasons, stable isotope ratio (SIR) analysis using an isotope ratio mass spectrometry (IRMS) instrument is one of the most useful techniques for evaluating food traceability and authenticity. The present study was aimed to determine, for the first time, the geographical origin for all commercial fish species belonging to the Merlucciidae family using SIR analysis of carbon (δ(13)C) and nitrogen (δ(15)N). The specific results enabled their clear classification according to the FAO (Food and Agriculture Organization of the United Nations) fishing areas, latitude, and geographical origin in the following six different clusters: European, North African, South African, North American, South American, and Australian hake species.

  18. Protein gels and emulsions from mixtures of Cape hake and pea proteins.

    PubMed

    Tomé, Ana Sofia; Pires, Carla; Batista, Irineu; Sousa, Isabel; Raymundo, Anabela

    2015-01-01

    Portioning of frozen fish generates by-products such as fish 'sawdust' and cut-offs which can be further processed into protein concentrates and isolates. The objective of the present work was to produce gels and emulsions using recovered Cape hake protein powder (HPP). In previous works, the structures of the gels produced by HPP were found to be strong, with a high rubbery character. In this work, the addition of commercial pea proteins (PPC) to HPP gels and emulsions was studied. Physical properties of gels and emulsions prepared with different proportions of mixtures of PPC and HPP were evaluated. In general, gels and emulsions showed high values for whiteness and, as expected, the higher content of HPP in the protein mixtures led to higher firmness values of the gels. The gel network was rapidly formed upon heating due to the fish protein macromolecules and further reinforced by the pea protein macromolecules when cooled to 5 °C. Both visco-elastic parameters, storage and loss moduli, of the produced gels increased with the HPP proportion in the protein mixtures, corresponding to more structured systems. For the emulsions, two different pH environments were studied: 3.8 and 7.0. At neutral pH a synergy was found between the vegetable and fish protein, which is not so strong when pH is lowered to 3.8, near the isoelectric point of pea proteins (pI = 4.5). This evidence was supported by the results from the texture measurements, viscosity and visco-elastic parameters. Gels made from Cape hake proteins showed a softer texture and were less rubbery with the addition of pea proteins. Emulsions stabilised by these mixtures showed slightly different behaviour when produced at pH 7.0 or pH 3.8. © 2014 Society of Chemical Industry.

  19. Pheromone disruption of Argentine ant trail integrity

    USGS Publications Warehouse

    Suckling, D.M.; Peck, R.W.; Manning, L.M.; Stringer, L.D.; Cappadonna, J.; El-Sayed, A. M.

    2008-01-01

    Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m2) to 1- and 4-m2 plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected. ?? 2008 Springer Science+Business Media, LLC.

  20. Effect of cooking on total mercury content in Norway lobster and European hake and public health impact.

    PubMed

    Perugini, Monia; Zezza, Daniela; Tulini, Serena Maria Rita; Abete, Maria Cesarina; Monaco, Gabriella; Conte, Annamaria; Olivieri, Vincenzo; Amorena, Michele

    2016-08-15

    The risk of Hg poisoning by eating seafood is considered real from the several international agencies that recommended, by fish consumption advisories, to pregnant women and young children to avoid or severely limit the consumption of the fish and shellfish with a high-range mercury levels. The analyses of two common species, European hake and Norway lobster, collected from an area of Central Adriatic Sea, reported high mercury levels in crustaceans. For Norway lobster total mercury exceeded, in six out of ten analysed pools, the recommended 0.5mg/kg wet weight European limit. Moreover the increased amount of Hg concentrations in Norway lobster cooked samples suggests the necessity to review current procedures of Hg control in food, considering also consumption habits of consumers. The Hg values found in all European hake samples are below the legal limits and, in this species, the boiling did not modify the concentrations in fish tissues.

  1. Material properties of Pacific hake, Humboldt squid, and two species of myctophids in the California Current.

    PubMed

    Becker, Kaylyn N; Warren, Joseph D

    2015-05-01

    Material properties of the flesh from three fish species (Merluccius productus, Symbolophorus californiensis, and Diaphus theta), and several body parts of the Humboldt squid (Dosidicus gigas) collected from the California Current ecosystem were measured. The density contrast relative to seawater varied within and among taxa for fish flesh (0.9919-1.036), squid soft body parts (mantle, arms, tentacle, braincase, eyes; 1.009-1.057), and squid hard body parts (beak and pen; 1.085-1.459). Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast relative to seawater varied within and among taxa for fish flesh (0.986-1.027) and Humboldt squid mantle and braincase (0.937-1.028). Material properties in this study are similar to values from previous studies on species with similar life histories. In general, the sound speed and density of soft body parts of fish and squid were 1%-3% and 1%-6%, respectively, greater than the surrounding seawater. Hard parts of the squid were significantly more dense (6%-46%) than seawater. The material properties reported here can be used to improve target strength estimates from acoustic scattering models, which could increase the accuracy of biomass estimates from acoustic surveys for these nekton.

  2. Argentine nuclear development: capabilities and implications

    SciTech Connect

    Watson, C.A.

    1984-01-01

    Complacency was shattered in 1974 by the Indian explosion of a nuclear device developed from a civil nuclear program. The fear of nuclear weapon spread led the international system to consider the other states that could develop devices from what were assumed to be peaceful nuclear programs. Many states of the non-nuclear ranks, often the more developed states of the Third World, resented the nuclear suppliers weapon holders dictating to the developing states the types of technology that these states could handle. Some of these developing states had highly sophisticated nuclear programs that no longer rely on the suppliers for assistance. These states are using the options that their nuclear developments present in an attempt to alter the international system, or the balance of power, that has existed since the end of World War II. Argentina's nuclear program has become one of the most-sophisticated in the Third World. This work discusses the implications of the country's present capabilities as they affect Argentine actions in the foreign policy areas of nuclear commerce and the international nuclear weapons non-proliferation regime.

  3. Antigenicity and viability of Anisakis larvae infesting hake heated at different time-temperature conditions.

    PubMed

    Vidacek, Sanja; de las Heras, Cristina; Solas, Maria Teresa; Mendizábal, Angel; Rodriguez-Mahillo, Ana I; Tejada, Margarita

    2010-01-01

    Heat treatments (40 to 94 degrees Celsius, 30 s to 60 min) were applied to different batches of Anisakis simplex L3 larvae isolated from hake ovaries and viscera to study the effect of heat on the viability of the larvae measured as mobility, emission of fluorescence under UV light, and changes in color after staining with specific dyes, and on A. simplex antigenic proteins. The aim was to determine the lowest time-temperature conditions needed to kill the larvae to avoid anisakiasis in consumers, and to evaluate whether high temperature modifies the antigenicity of A. simplex extracts. Heating at 60 degrees Celsius for 10 min (recommended by some authors) was considered unsafe, as differences in viability between batches were found, with some larvae presenting spontaneous movements in one batch. At higher temperatures (> or = 70 degrees Celsius for > or = 1 min), no movement of the larvae was observed. Antigenic protein Ani s 4 and A. simplex crude antigens were detected in the larvae heated at 94 + or - 1 degrees Celsius for 3 min. This indicates that allergic symptoms could be provoked in previously sensitized consumers, even if the larvae were killed by heat treatment.

  4. Hake fish bone as a calcium source for efficient bone mineralization.

    PubMed

    Flammini, Lisa; Martuzzi, Francesca; Vivo, Valentina; Ghirri, Alessia; Salomi, Enrico; Bignetti, Enrico; Barocelli, Elisabetta

    2016-01-01

    Calcium is recognized as an essential nutritional factor for bone health. An adequate intake is important to achieve or maintain optimal bone mass in particular during growth and old age. The aim of the present study was to evaluate the efficiency of hake fish bone (HBF) as a calcium source for bone mineralization: in vitro on osteosarcoma SaOS-2 cells, cultured in Ca-free osteogenic medium (OM) and in vivo on young growing rats fed a low-calcium diet. Lithotame (L), a Ca supplement derived from Lithothamnium calcareum, was used as control. In vitro experiments showed that HBF supplementation provided bone mineralization similar to standard OM, whereas L supplementation showed lower activity. In vivo low-Ca HBF-added and L-added diet similarly affected bone deposition. Physico-chemical parameters concerning bone mineralization, such as femur breaking force, tibia density and calcium/phosphorus mineral content, had beneficial effects from both Ca supplementations, in the absence of any evident adverse effect. We conclude HBF derived from by-product from the fish industry is a good calcium supplier with comparable efficacy to L.

  5. [The Argentine Health System: organization and financial features].

    PubMed

    Arce, Hugo E

    2012-01-01

    The Argentine health system is defined by the following features: a) federal country organization; b) coexistence of public and private services with either outpatients or inpatients; c) fragmented entities of social security, most of these originated outside of the state organization. Components of the system are described and weighed; making decisions strength between national and provincial health authorities is analyzed and the Argentine system is compared with that of other countries. Statistical data on distribution of health expenditures and coverage of health services are presented as well as financial flow among diverse funding sources, insurers, providers and users of each sector.

  6. Genetic diversity of Argentine isolates of feline immunodeficiency virus.

    PubMed

    Pecoraro, M R; Tomonaga, K; Miyazawa, T; Kawaguchi, Y; Sugita, S; Tohya, Y; Kai, C; Etcheverrigaray, M E; Mikami, T

    1996-09-01

    We report the nucleotide sequence and genetic diversity of part of the envelope (env) gene of four strains of feline immunodeficiency virus (FIV) isolated from Argentine domestic cats. The DNA encoding the V3 to V5 regions of the env gene of the FIV isolates were amplified by PCR, cloned and sequenced. Phylogenetic analysis revealed that the Argentine isolates did not cluster into a single group; one isolate clustered with subtype B FIV isolated in the USA and Japan, whereas the others formed a new cluster of FIV which might represent a prototype sequence for subtype E.

  7. Different Argentine Rural Extensionists' Mindsets and Their Practical Implications

    ERIC Educational Resources Information Center

    Landini, Fernando

    2015-01-01

    Purpose: This paper reflects upon the practice of Argentine rural extensionists working in the extension public system through the process of identifying different rural extensionists' types of mindsets and comparing them with transfer of technology extension approach, dialogical processes of horizontal knowledge exchange, participatory…

  8. The Mindful Attention Awareness Scale (MAAS) in an Argentine Population

    ERIC Educational Resources Information Center

    Montes, Silvana Andrea; Ledesma, Rubén Daniel; García, Natalia Mariana; Poó, Fernando Martín

    2014-01-01

    The purpose of this study was to provide evidence of validity for the Mindful Attention Awareness Scale scores in an Argentine sample (Spanish-language version). Results indicated satisfactory psychometric properties (a one-factor structure, good item discrimination, high reliability, and significant correlations with additional measures). This…

  9. Different Argentine Rural Extensionists' Mindsets and Their Practical Implications

    ERIC Educational Resources Information Center

    Landini, Fernando

    2015-01-01

    Purpose: This paper reflects upon the practice of Argentine rural extensionists working in the extension public system through the process of identifying different rural extensionists' types of mindsets and comparing them with transfer of technology extension approach, dialogical processes of horizontal knowledge exchange, participatory…

  10. The Mindful Attention Awareness Scale (MAAS) in an Argentine Population

    ERIC Educational Resources Information Center

    Montes, Silvana Andrea; Ledesma, Rubén Daniel; García, Natalia Mariana; Poó, Fernando Martín

    2014-01-01

    The purpose of this study was to provide evidence of validity for the Mindful Attention Awareness Scale scores in an Argentine sample (Spanish-language version). Results indicated satisfactory psychometric properties (a one-factor structure, good item discrimination, high reliability, and significant correlations with additional measures). This…

  11. The Argentine ant persists through unfavorable winters via a mutualism facilitated by a native tree.

    PubMed

    Brightwell, Robert J; Silverman, Jules

    2011-10-01

    Mutualisms and facilitations can fundamentally change the relationship between an organism's realized and fundamental niche. Invasive species may prove particularly suitable models for investigating this relationship as many are dependent on finding new partners for successful establishment. We conducted field-based experiments testing whether a native tree facilitates the successful survival of the invasive Argentine ant, Linepithema humile (Mayr), through unfavorable winter conditions in the southeastern United States. We found Argentine ant nests aggregated around the native loblolly pine, Pinus taeda L., during the winter months. The bark of this tree absorbed enough radiant solar energy to reach temperatures suitable for Argentine ant foraging even when ambient temperatures should have curtailed all foraging. Conversely, foraging ceased when the trunk was shaded. The sun-warmed bark of this tree gave the Argentine ant access to a stable honeydew resource. Argentine ants were not found on or near deciduous trees even though bark temperatures were warm enough to permit Argentine ant foraging on cold winter days. Augmenting deciduous trees with sucrose water through the winter months lead to Argentine ant nests remaining at their base and Argentine ants foraging on the tree. The Argentine ant requires both foraging opportunity and a reliable winter food source to survive through unfavorable winter conditions in the southeastern United States. The loblolly pine provided both of these requirements extending the realized niche of Argentine ants beyond its fundamental niche.

  12. Parasitoids deter foraging by Argentine ants (Linepithema humile) in their native habitat in Brazil.

    PubMed

    Orr, Matthew R; Seike, Sergio H

    1998-12-01

    The Argentine ant, Linepithema humile, has invaded sites across Africa, Australia, Europe, and North America. In its introduced ranges it eliminates native ants and tends agricultural pests. Few studies have examined the ecology of Argentine ants in their native habitat. This study examined the effects of parasitoid flies, genus Pseudacteon, on the foraging behavior of Argentine ants in part of their native range in southern Brazil. Pseudacteon parasitoids commonly attacked Argentine ants, but not other ant species, in daylight at temperatures above 18°C. Argentine ants abandoned food resources and returned underground in the presence of parasitoids. Parasitoid attack rates diminished as Argentine ants retreated underground. Where parasitoids were present, Argentine ants were abundant at food resources only during times of day when parasitoids were inactive. Where parasitoids were absent, Argentine ants were abundant at food resources throughout the day. Overall, the presence of parasitoids explained observed variation in Argentine ant foraging far better than temperature, although temperature had some effect. The results suggest that Pseudacteon parasitoids inhibit the ability of Argentine ants to gather food resources in their native habitat in Brazil.

  13. Bottom current influenced sedimentation in the Argentine Basin and on the Argentine Continental Margin reflected in high resolution seismic data

    NASA Astrophysics Data System (ADS)

    von Lom-Keil, H.; Schacht, R.; Spiess, V.

    2003-04-01

    Sediment deposition and distribution in the western Argentine Basin and along the Argentine continental margin is strongly influenced by deep water current activity, i.e. the Antarctic Bottom Water (AABW), spreading northward along the continental margin below 4000 m, the southward flowing North Atlantic Deep Water (NADW) between 1500 and 3500 m and the northward oriented Antarctic Intermediate Water (AAIW) between 700 and 1100 m. Furthermore the Argentine continental margin is characterised by numerous deep incisions and channels, supporting vertical gravity driven sediment transport. In January 2000 and February 2001 cruises with R/V Meteor in the western South Atlantic Ocean, performed as part of the former Bremen Special Research Project 261 (Cruise M46/3) and as an ODP pre-site survey (Cruise M49/2), provided high resolution seismic information on the internal structure of these complex sedimentary structures. The south west Argentine Basin is covered by the huge Zapiola sediment drift, which reaches a sediment thickness of up to 3 km and is draped by extended fields of sediment waves. High resolution seismic profiles across the western part of the drift deposits allow a closer inspection of the onset and growth of the sediment wave coverage, which starts at 400 ms below seafloor. The data also suggest a movement of the western drift crest to the south west during the growth of the drift. Drift deposits, showing evidence of strong bottom water activity, are also a widespread feature along the deeper Argentine continental margin, especially in vicinity of deeply incised channels. These deposits are often associated with topside or embedded sediment layers showing a wavy topography. Further upslope indications for bottom current erosion can be identified as well as downslope sediment transport forming thick slump deposits.

  14. Two new species of Clestobothrium (Cestoda: Bothriocephalidea), parasites of Merluccius australis and m. hubbsi (Gadiformes: Merlucciidae) from the Patagonian shelf of Argentina, with comments on Clestobothrium crassiceps (Rudolphi, 1819).

    PubMed

    de Pertierra, Alicia A Gil; Incorvaia, Inés S; Arredondo, Nathalia J

    2011-06-01

    Abstract: Two new species of bothriocephalidean cestodes, Clestobothrium splendidum sp. n. from Merluccius australis (Hutton) and Clestobothrium cristinae sp. n. from Merluccius hubbsi Marini from the Patagonian shelf of Argentina, are described. Clestobothrium splendidum can be typified by the following characteristics: a medium-sized strobila composed of410-528 proglottides that are much wider than long; 49-90 testes per mature proglottis, partially surrounding the ovary posteriorly; a transversely elongated genital pore situated anterior to spurious articulations; presence of a genital atrium; a globular cirrus-sac occupying 4-6% of mature proglottis width; a vagina with sphincter and three pairs of osmoregulatory canals on each side of the proglottis. Clestobothrium cristinae is characterised by its small size; 71-219 proglottides; 39-64 testes per mature proglottis, usually surrounding completely the ovary posteriorly; a rounded genital pore situated at the same level of spurious articulations; an oval cirrus-sac occupying 8-16% of mature proglottis width; and three pairs of osmoregulatory canals on each side of the proglottis. Clestobothrium cristinae shares with C. splendidum the type and distribution of microtriches, except for the central surface delimited by two lips. Additionally, type and voucher materials of Clestobothrium crassiceps (Rudolphi, 1819) from Merluccius merluccius were studied. A key to species is provided.

  15. Exploitation and interference competition between the invasive Argentine ant, Linepithema humile, and native ant species.

    PubMed

    Human, Kathleen G; Gordon, Deborah M

    1996-02-01

    Interactions between the invasive Argentine ant, Linepithema humile, and native ant species were studied in a 450-ha biological reserve in northern California. Along the edges of the invasion, the presence of Argentine ants significantly reduced the foraging success of native ant species, and vice versa. Argentine ants were consistently better than native ants at exploiting food sources: Argentine ants found and recruited to bait more consistently and in higher numbers than native ant species, and they foraged for longer periods throughout the day. Native ants and Argentine ants frequently fought when they recruited to the same bait, and native ant species were displaced from bait during 60% of these encounters. In introduction experiments, Argentine ants interfered with the foraging of native ant species, and prevented the establishment of new colonies of native ant species by preying upon winged native ant queens. The Argentine ants' range within the preserve expanded by 12 ha between May 1993 and May 1994, and 13 between September 1993 and September 1994, with a corresponding reduction of the range of native ant species. Although some native ants persist locally at the edges of the invasion of Argentine ants, most eventually disappear from invaded areas. Both interference and exploitation competition appear to be important in the displacement of native ant species from areas invaded by Argentine ants.

  16. Fast and Flexible: Argentine Ants Recruit from Nearby Trails

    PubMed Central

    Flanagan, Tatiana P.; Pinter-Wollman, Noa M.; Moses, Melanie E.; Gordon, Deborah M.

    2013-01-01

    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources. PMID:23967129

  17. [Argentine consensus on the treatment of bipolar disorders].

    PubMed

    Vázquez, Gustavo Héctor; Strejilevich, Sergio; García Bonetto, Gerardo; Cetkovich-Bakmas, Marcelo; Zaratiegui, Rodolfo; Lagomarsino, Alejandro; Goldchluk, Aníbal; Kalina, Eduardo; Herbst, Luis; Gutiérrez, Benigno

    2005-01-01

    The consensus guidelines of argentine experts in the treatment of bipolar disorders are the result of three days of work of the 10 main local experts under the organization of the Argentine Association of Biological Psychiatry (AAPB). It was adopted a mixed criterion for its preparation: all the recent data of the evidence medicine based published until now were discussed and were balanced with the knowledge acquired from clinical experience of the local experts on the bipolar field. It presents general recommendations and suggested therapeutic sequences for the phase of maintenance, the manic/hypomanic or mixed episode and the depressive episode. These have been divided according to the classification in type I and II; with or without rapid cycling. Since the group of experts identified the delay and miss-diagnoses like the most important barrier for a suitable treatment enclosed a series of recommendations for differential diagnosis of bipolar disorders.

  18. Fast and flexible: argentine ants recruit from nearby trails.

    PubMed

    Flanagan, Tatiana P; Pinter-Wollman, Noa M; Moses, Melanie E; Gordon, Deborah M

    2013-01-01

    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

  19. Paleomagnetic confirmation of the Laurentian origin of the Argentine Precordillera

    NASA Astrophysics Data System (ADS)

    Rapalini, A. E.; Astini, R. A.

    1998-02-01

    Several recent tectonic models have portrayed the Argentine Precordillera has been recently portrayed as an Early Paleozoic Laurentian derived exotic terrane now found in southwestern South America. These models have primarily been based on strong biogeographic and stratigraphic evidence, however, no paleomagnetic data have previously been available to independently test them. A paleomagnetic study was, therefore, carried out on the Early Cambrian Cerro Totora Formation, exposed in the northern reaches of the Argentine Precordillera. After stepwise thermal demagnetization a pre-folding remanence was identified in ten sites of this formation, yielding a paleomagnetic pole (CT) at 37.0°N, 314.1°E, A95=5.8°. This pole is not consistent with the latest Proterozoic-Early Paleozoic apparent polar wander path for Gondwana, but it agrees with the Early Cambrian Section of the Laurentian path if the Argentine Precordillera is positioned as the conjugate margin of the Ouachita embayment in southeast Laurentia. This result confirms that the Precordillera is an allochthonous terrane derived from Laurentia in Cambrian times, that was later accreted to Gondwana, probably in Middle Ordovician times.

  20. Argentine Population Genetic Structure: Large Variance in Amerindian Contribution

    PubMed Central

    Seldin, Michael F.; Tian, Chao; Shigeta, Russell; Scherbarth, Hugo R.; Silva, Gabriel; Belmont, John W.; Kittles, Rick; Gamron, Susana; Allevi, Alberto; Palatnik, Simon A.; Alvarellos, Alejandro; Paira, Sergio; Caprarulo, Cesar; Guillerón, Carolina; Catoggio, Luis J.; Prigione, Cristina; Berbotto, Guillermo A.; García, Mercedes A.; Perandones, Carlos E.; Pons-Estel, Bernardo A.; Alarcon-Riquelme, Marta E.

    2011-01-01

    Argentine population genetic structure was examined using a set of 78 ancestry informative markers (AIMs) to assess the contributions of European, Amerindian, and African ancestry in 94 individuals members of this population. Using the Bayesian clustering algorithm STRUCTURE, the mean European contribution was 78%, the Amerindian contribution was 19.4%, and the African contribution was 2.5%. Similar results were found using weighted least mean square method: European, 80.2%; Amerindian, 18.1%; and African, 1.7%. Consistent with previous studies the current results showed very few individuals (four of 94) with greater than 10% African admixture. Notably, when individual admixture was examined, the Amerindian and European admixture showed a very large variance and individual Amerindian contribution ranged from 1.5 to 84.5% in the 94 individual Argentine subjects. These results indicate that admixture must be considered when clinical epidemiology or case control genetic analyses are studied in this population. Moreover, the current study provides a set of informative SNPs that can be used to ascertain or control for this potentially hidden stratification. In addition, the large variance in admixture proportions in individual Argentine subjects shown by this study suggests that this population is appropriate for future admixture mapping studies. PMID:17177183

  1. [Behavior of Argentine lymphocytic choriomeningitis virus strains in rodents].

    PubMed

    Saavedra, María del Cármen; Ambrosio, Ana M; Riera, Laura; Sabattini, Marta S

    2007-01-01

    The activity of LCM virus was first reported in Argentina at the beginning of the seventies and only five strains have been isolated from rodents Mus domesticus and two from humans. The objective of this paper was to find differential biological characteristics of Argentine strains of LCM virus comparing them in relation to the historical strains WE and Armstrong. Regarding the results obtained in tissue culture, when L 929 cells were used, plaque forming units (PFU) were obtained with human and mouse strains, whilst on Vero cells only human strains developed PFU. Differentials characteristics of historical and Argentine strain's plates were not found, neither differences related to the strain's origin. Neither historical nor Argentine strains were lethal to new-born mice giving a persistent infection, that was demonstrated when we inoculated new-born mouse by intracranial route with different strains of LCM virus and virus was isolated from brains harvested at different days post inoculation. The only exception was Cba An 13065 strain that exhibited virulence in new-born mice, only with 0.026 PFU was obtained 1 DL50. All the strains resulted lethal to adult mice. The mouse strains were more virulent than human strains, being Cba An 13065 the most virulent. These results demonstrate a different behavior in tissue culture between human and mouse strains and allow the identification of virulence markers by intracranial inoculation into new-born or adult mice.

  2. Trail Pheromone of the Argentine Ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae)

    PubMed Central

    Choe, Dong-Hwan; Villafuerte, David B.; Tsutsui, Neil D.

    2012-01-01

    The Argentine ant (Linepithema humile) is recognized as one of the world's most damaging invasive species. One reason for the ecological dominance of introduced Argentine ant populations is their ability to dominate food and habitat resources through the rapid mobilization and recruitment of thousands of workers. More than 30 years ago, studies showed that (Z)-9-hexadecenal strongly attracted Argentine ant workers in a multi-choice olfactometer, suggesting that (Z)-9-hexadecenal might be the trail pheromone, or a component of a trail pheromone mixture. Since then, numerous studies have considered (Z)-9-hexadecenal as the key component of the Argentine ant trails. Here, we report the first chemical analyses of the trails laid by living Argentine ants and find that (Z)-9-hexadecenal is not present in a detectible quantity. Instead, two iridoids, dolichodial and iridomyrmecin, appear to be the primary chemical constituents of the trails. Laboratory choice tests confirmed that Argentine ants were attracted to artificial trails comprised of these two chemicals significantly more often than control trails. Although (Z)-9-hexadecenal was not detected in natural trails, supplementation of artificial dolichodial+iridomyrmecin trails with an extremely low concentraion of (Z)-9-hexadecenal did increase the efficacy of the trail-following behavior. In stark contrast with previous dogma, our study suggests that dolichodial and iridomyrmecin are major components of the Argentine ant trail pheromone. (Z)-9-hexadecenal may act in an additive manner with these iridoids, but it does not occur in detectable quantities in Argentine ant recruitment trails. PMID:23028739

  3. Trail pheromone of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae).

    PubMed

    Choe, Dong-Hwan; Villafuerte, David B; Tsutsui, Neil D

    2012-01-01

    The Argentine ant (Linepithema humile) is recognized as one of the world's most damaging invasive species. One reason for the ecological dominance of introduced Argentine ant populations is their ability to dominate food and habitat resources through the rapid mobilization and recruitment of thousands of workers. More than 30 years ago, studies showed that (Z)-9-hexadecenal strongly attracted Argentine ant workers in a multi-choice olfactometer, suggesting that (Z)-9-hexadecenal might be the trail pheromone, or a component of a trail pheromone mixture. Since then, numerous studies have considered (Z)-9-hexadecenal as the key component of the Argentine ant trails. Here, we report the first chemical analyses of the trails laid by living Argentine ants and find that (Z)-9-hexadecenal is not present in a detectible quantity. Instead, two iridoids, dolichodial and iridomyrmecin, appear to be the primary chemical constituents of the trails. Laboratory choice tests confirmed that Argentine ants were attracted to artificial trails comprised of these two chemicals significantly more often than control trails. Although (Z)-9-hexadecenal was not detected in natural trails, supplementation of artificial dolichodial+iridomyrmecin trails with an extremely low concentraion of (Z)-9-hexadecenal did increase the efficacy of the trail-following behavior. In stark contrast with previous dogma, our study suggests that dolichodial and iridomyrmecin are major components of the Argentine ant trail pheromone. (Z)-9-hexadecenal may act in an additive manner with these iridoids, but it does not occur in detectable quantities in Argentine ant recruitment trails.

  4. Deterrency and Toxicity of Essential Oils to Argentine and Red Imported Fire Ants (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    Laboratory assays were conducted to evaluate deterrency and contact toxicity of six essential oils to the Argentine ant, Linepithema humile (Mayr), and the red imported fire ant, Solenopsis invicta Buren. In choice tests, both Argentine ants and fire ants crossed barriers treated with multiple rates...

  5. Gas-Phase Intramolecular Cyclization of Argentinated N-Allylbenzamides

    NASA Astrophysics Data System (ADS)

    Sun, Hezhi; Chai, Yunfeng; Jin, Zhe; Sun, Cuirong; Pan, Yuanjiang

    2015-05-01

    The fragmentations of argentinated N-allylbenzamides have been exhaustively studied through collision-induced dissociation and through deuterium labeling. The intriguing elimination of AgOH is certified as the consequence of intramolecular cyclization between terminal olefin and carbonyl carbon following proton transfer to carbonyl oxygen, rather than simple enolization of amide. Linear free energy correlations and density functional theory (DFT) calculations were performed to understand the competitive relationship between AgOH loss and AgH loss, which results from the 1,2-elimination of α-hydrogen (to the amido nitrogen) with the silver.

  6. From individual to collective dynamics in Argentine ants (Linepithema humile).

    PubMed

    Vela-Pérez, M; Fontelos, M A; Garnier, S

    2015-04-01

    In this paper we propose a model for the formation of paths in Argentine ants when foraging in an empty arena. Based on experimental observations, we provide a distribution for the random change in direction that they approximately undergo while foraging as a mixture of a Gaussian and a Pareto distribution. By following the principles described in previous work, we consider persistence and reinforcement to create a model for the motion of ants in the plane. Numerical simulations based on this model lead to the formation of branched ant-trails analogous to those observed experimentally. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Experience influences aggressive behaviour in the Argentine ant

    PubMed Central

    Van Wilgenburg, Ellen; Clémencet, Johanna; Tsutsui, Neil D.

    2010-01-01

    All animals interact with conspecifics during their life, and nearly all also display some form of aggression. An enduring challenge, however, is to understand how the experiences of an individual animal influence its later behaviours. Several studies have shown that prior winning experience increases the probability of initiating fights in later encounters. Using behavioural assays in the laboratory, we provide evidence that, in Argentine ants (Linepithema humile), the mere exposure to an opponent, without the encounter escalating to a fight, also increases the probability that it will display aggression in later encounters. Argentine ant workers differ in their propensity to attack non-colonymates, with some ants repeatedly aggressive and others consistently more docile. Although 78 per cent of the workers were consistent in their behaviour from one encounter to the next, workers that did change their behaviour after an encounter with a non-colonymate more often changed from non-aggressive to aggressive, rather than the reverse. Surprisingly, a single encounter with a non-colonymate increased a worker's propensity to fight in encounters up to a week later. An encounter with a non-colonymate also increased the probability that a worker would attack ants from a colony that it had not previously encountered. Thus, these interactions lowered the overall aggression threshold, rather than stimulating a specific aggressive response to a particular foreign colony. Finally, our data suggest that aggression towards non-colonymates increases with age. PMID:19793741

  8. Trail pheromone disruption of Argentine ant trail formation and foraging.

    PubMed

    Suckling, David Maxwell; Peck, Robert W; Stringer, Lloyd D; Snook, Kirsten; Banko, Paul C

    2010-01-01

    Trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. Argentine ant trail pheromone, (Z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against Argentine ant populations in 400 m2 field plots in Hawai'i Volcanoes National Park. A widely dispersed point source strategy for trail pheromone disruption was used. Traffic rates of ants in bioassays of treated filter paper, protected from rainfall and sunlight, indicated the presence of behaviorally significant quantities of pheromone being released from the formulation for up to 59 days. The proportion of plots, under trade wind conditions (2–3 m s−1), with visible trails was reduced for up to 14 days following treatment, and the number of foraging ants at randomly placed tuna-bait cards was similarly reduced. The success of these trail pheromone disruption trials in a natural ecosystem highlights the potential of this method for control of invasive ant species in this and other environments.

  9. Protein that makes sense in the Argentine ant

    NASA Astrophysics Data System (ADS)

    Ishida, Yuko; Chiang, Vicky; Leal, Walter

    2002-10-01

    With a protein-based approach, we have identified and cloned the cDNA encoding a chemosensory protein (LhumCSP) in the Argentine ant, Linepithema humile. The open reading frame of the cloned cDNA encoded a signal peptide (20 residues), and a mature protein (pI 4.62) of 106 amino acid residues. The calculated molecular mass (12,453 Da) was in agreement with the molecular mass measured by on-line chromatography-electrospray ionization mass spectrometry (12,448 Da), given the formation of two disulfide bridges. LhumCSP shared sequence similarity with various CSPs, particularly those identified and/or cloned from moth species. Also, LhumCSP showed the hallmark of the chemosensory proteins, i.e., four well conserved cysteine residues. The antennal protein was not detected in non-olfactory tissues (leg and thorax) contrary to a putative pheromone-binding protein isolated from the thorax of the red imported fire ant, Solenopsis invicta. In addition, these findings suggest that, as in Orthopterans and Phasmids, the protein that makes sense in the Argentine ant is not an odorant-binding protein, but rather a chemosensory protein.

  10. Trail Pheromone Disruption of Argentine Ant Trail Formation and Foraging

    USGS Publications Warehouse

    Suckling, D.M.; Peck, R.W.; Stringer, L.D.; Snook, K.; Banko, P.C.

    2010-01-01

    Trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. Argentine ant trail pheromone, (Z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against Argentine ant populations in 400 m2 field plots in Hawai'i Volcanoes National Park. A widely dispersed point source strategy for trail pheromone disruption was used. Traffic rates of ants in bioassays of treated filter paper, protected from rainfall and sunlight, indicated the presence of behaviorally significant quantities of pheromone being released from the formulation for up to 59 days. The proportion of plots, under trade wind conditions (2-3 m s-1), with visible trails was reduced for up to 14 days following treatment, and the number of foraging ants at randomly placed tuna-bait cards was similarly reduced. The success of these trail pheromone disruption trials in a natural ecosystem highlights the potential of this method for control of invasive ant species in this and other environments. ?? Springer Science+Business Media, LLC 2010.

  11. New mutualism for old: indirect disruption and direct facilitation of seed dispersal following Argentine ant invasion.

    PubMed

    Rowles, Alexei D; O'Dowd, Dennis J

    2009-01-01

    The indirect effects of biological invasions on native communities are poorly understood. Disruption of native ant communities following invasion by the Argentine ant (Linepithema humile) is widely reported to lead indirectly to the near complete collapse of seed dispersal services. In coastal scrub in southeastern Australia, we examined seed dispersal and handling of two native and two invasive alien plant species at Argentine ant-invaded or -uninvaded sites. The Argentine ant virtually eliminates the native keystone disperser Rhytidoponera victoriae, but seed dispersal did not collapse following invasion. Indeed, Argentine ants directly accounted for 92% of all ant-seed interactions and sustained overall seed dispersal rates. Nevertheless, dispersal quantity and quality among seed species differed between Argentine ant-invaded and -uninvaded sites. Argentine ants removed significantly fewer native Acacia retinodes seeds, but significantly more small seeds of invasive Polygala myrtifolia than did native ants at uninvaded sites. They also handled significantly more large seeds of A. sophorae, but rarely moved them >5 cm, instead recruiting en masse, consuming elaiosomes piecemeal and burying seeds in situ. In contrast, Argentine ants transported and interred P. myrtifolia seeds in their shallow nests. Experiments with artificial diaspores that varied in diaspore and elaiosome masses, but kept seed morphology and elaiosome quality constant, showed that removal by L. humile depended on the interaction of seed size and percentage elaiosome reward. Small diaspores were frequently taken, independent of high or low elaiosome reward, but large artificial diaspores with high reward instead elicited mass recruitment by Argentine ants and were rarely moved. Thus, Argentine ants appear to favour some diaspore types and reject others based largely on diaspore size and percentage reward. Such variability in response indirectly reduces native seed dispersal and can directly

  12. Fecundity and longevity of Argentine ant (Hymenoptera: Formicidae) queens in response to irradiation

    USDA-ARS?s Scientific Manuscript database

    Irradiation is a postharvest quarantine treatment option to control ants and other hitchhiker pests on fresh horticultural products traded between countries. As little is known about irradiation effects on ants, radiotolerance of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae...

  13. Activity of Bifenthrin, Chlorfenapyr, Fipronil, and Thiamethoxam against Argentine Ants (Hymenoptera: Formicidae)

    USDA-ARS?s Scientific Manuscript database

    Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the Argentine ant, Linepithema humile (Mayr). Mobility impairment and lethal times were determined following topical treatments. Ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and th...

  14. A Framework for Improving Integrative Factors in C3I Systems of the Argentine Army

    DTIC Science & Technology

    1991-03-01

    improving integrative factors in C3I systems of the Argentine Army by Eduardo Alfredo Trotta Major, Argentine Army Ingeniero Militar, Escuela...commander’s intelligence, not as substitute of it. 39 Decision Aids can help military personnel by reducing stress, information overload and manual ...its antijamming characteristics. The system design goals include a manual -mode interface with the ACUS, and in the near future, an automated-mode

  15. A Basis for a Command, Control and Communications (C3) System Architecture for the Argentine Army

    DTIC Science & Technology

    1990-03-01

    System Architecture for the Argentine Army by Juan Carlos Maidana Major, Argentine Army Ingeniero Militar, Escuela Superior Tecnica, Buenos Aires...warfare (IEW), and combat service support (CSS). These proc- esses are automated or manual , and they are designed to support the internal technical mission...documents used to regulate command and control actixities within the Army up to that moment were the following: * The manual "Organization and Functioning of

  16. Lymphocyte subsets alteration in patients with argentine hemorrhagic fever.

    PubMed

    Vallejos, D A; Ambrosio, A M; Feuillade, M R; Maiztegui, J I

    1989-02-01

    Peripheral blood lymphocyte subpopulations were studied in 15 patients with Argentine Hemorrhagic Fever (AHF), during the acute period of the disease and in early convalescence. Anti-human Ig antibodies were used to identify B cells and monoclonal antibodies to assess T4 and T8 subsets. During the acute period of the disease, significant alterations were found in B, T4, and T8 lymphocytes (P less than .001), as well as in T4/T8 ratios (P less than .001). These abnormalities disappeared in early convalescence, around 30 days after the clinical onset. Diminished numbers of T4 lymphocytes are interpreted as relevant to the immunodepression that characterizes the acute phase of AHF.

  17. Space Weather Impact on Pipeline in La Plata City, Argentine

    NASA Astrophysics Data System (ADS)

    Gianibelli, J. C.; Dovico, R. O.; Peirtti, R. O.; Pretel, R. O.; Garcia, R. E.; Quaglino, N. M.

    2007-05-01

    In the Sun-Earth connection, some of the most important characteristic events involved are the Coronal Mass Ejections (CME) and the high speed particle streams events coming from the Coronal Holes at the Sun. These interplanetary events produce effects on space and ground-based technology. In the present work, the geomagnetic storm recorded at Las Acacias Digital Magnetic Observatory (LAS, Lat.:-35º.0; Long.: 302º.3) produced by a particle stream from a solar coronal hole and their relationship with the induction effects caused on a pipeline in the shore of La Plata city, Argentine. The result shows an increase of the induced current correlated with the registered geomagnetic storm. Also, the magnetically calm days are analized. It is concluded that the amplitude of induced current intensity verifies a logarithmic relation with the amplitude of total magnetic intensity recorded in Las Acacias Observatory.

  18. Argentine gas system underway for Gas del Estado

    SciTech Connect

    Bosch, H.

    1980-10-01

    Gas del Estado's giant 1074-mile Centro-Oeste pipeline project - designed to ultimately transport over 350 million CF/day of natural gas from the Neuquen basin to the Campo Duran-Buenos Aires pipeline system - is now underway. The COGASCO consortium of Dutch and Argentine companies awarded the construction project will also operate and maintain the system for 15 years after its completion. In addition to the 30-in. pipelines, the agreement calls for a major compressor station at the gas field, three intermediate compressor stations, a gas-treatment plant, liquids-recovery facilities, and the metering, control, communications, and maintenance equipment for the system. Fabricated in Holland, the internally and externally coated pipe will be double-jointed to 80-ft lengths after shipment to Argentina; welders will use conventional manual-arc techniques to weld the pipeline in the field.

  19. TGS pipeline primed for Argentine growth, CEO says

    SciTech Connect

    Share, J.

    1997-03-01

    Nowhere in Latin America has the privatization process been more aggressively pursued than in Argentina where President Carlos Menem has successfully turned over the bulk of state companies to the private sector. In the energy sector, that meant the divestiture in 1992 of Gas del Estado, the state-owned integrated gas transportation and distribution company. It was split in two transportation companies: Transportadora de Gas del Sur (TGS) and Transportadora de Gas del Norte (TGN), and eight distribution companies. TGS is the largest transporter of natural gas in Argentina, delivering more than 60 percent of that nation`s total gas consumption with a capacity of 1.9 Bcf/d. This is the second in a series of Pipeline and Gas Journal special reports that discuss the evolving strategies of the natural gas industry as it continues to restructure amid deregulation. The article focuses on TGS, the Argentine pipeline system in which Enron Corp. is a key participant.

  20. Trauma and Contemporary Forms of Subjectivity: Contributions of Argentine Psychoanalysis().

    PubMed

    Volnovich, Juan Carlos

    2017-04-01

    This paper offers arguments to justify the relevance of psychoanalysis-psychoanalyses-in present-day Argentina and reflects on the stance taken by psychoanalysts with different theoretical perspectives in the face of the havoc wreaked by state terror (1976-1983). To this end, the author focuses on the pioneers' traits, the significance of the Argentine Psychoanalytic Association in the 1950s and 1960s, and the impact of the departure of the Plataforma Group in 1971. The establishment of the latter opened the way for the development of a psychoanalysis tied to popular movements, sensitive to social conflict, and close to human rights organizations. The author explores both on psychoanalysts' intervention to address the social trauma resulting from the theft of babies during the dictatorship, and on their relationship with Grandmothers of Plaza de Mayo.

  1. Soils of the Galindez Island, Argentine archipelago, Western Antarctica

    NASA Astrophysics Data System (ADS)

    Abakumov, Evgeny; Parnikoza, Ivan

    2015-04-01

    Antarctic Peninsula is a part of Antarctica which is characterized by increased soil diversity, caused by specific of parent materials and diversity of non-vascular and vascular plants. Soils of Galindez Island have been investigated during the 18-th Ukranian Antarctic Expedition 2013/14. This Island situated in Argentine archipelago (coastal part of Antarctic Peninsula). Soils of Galindez Island presented by following types: Leptosols, Lithosols, Histic Lithosols and Leptosols and some Gleyic soils, located in lowlands and coastal parts. An average solum profile thickness is 3-19 cm which result from the small depth of debris's, underplayed by massive crystallic rocks. The permafrost layer is located within the massive rock, but not in coarse friable parent material. The soils with bird influence are widely spread both in coastal and central part of Island. In the coastal parts we can find typical Ornithosols in the penguin rockeries areas. The main aim of our investigation was characterization of soils formed under vegetation, exactly under Deschampsia antarctica Desv. localities. Argentine Islands is the central part of D. antarctica spreading area in region of Antarctic peninsula. Probably, these islands colonized by hairgrass mainly due to ornitogenic activity. So, coastal population appearance related with Larus dominicanus nest areas and feeding activity. Thus, we found typical post ornithogenic soils here. This kind of soils we also observed in population of hairgrass of Galindez mainland where it was connected with the other Antarctic bird - Catharacta maccormicki activity. Thus, the soil diversity and soil geochemistry of the Galindez Island are closely related to the activity of birds. The spatial pattern of soils, their chemistry and organic matter quality is discussed in relation with distribution of bird nesting and feeding activity.

  2. Colony-structure variation and interspecific competitive ability in the invasive Argentine ant.

    PubMed

    Holway, David A; Suarez, Andrew V

    2004-01-01

    The success of some invasive species may depend on phenotypic changes that occur following introduction. In Argentine ants (Linepithema humile) introduced populations typically lack intraspecific aggression, but native populations display such behavior commonly. We employ three approaches to examine how this behavioral shift might influence interspecific competitive ability. In a laboratory experiment, we reared colonies of Forelius mccooki with pairs of Argentine ant colonies that either did or did not exhibit intraspecific aggression. F. mccooki reared with intraspecifically non-aggressive pairs of Argentine ants produced fewer eggs, foraged less actively, and supported fewer living workers than those reared with intraspecifically aggressive pairs. At natural contact zones between competing colonies of L. humile and F. mccooki, the introduction of experimental Argentine ant colonies that fought with conspecific field colonies caused L. humile to abandon baits in the presence of F. mccooki, whereas the introduction of colonies that did not fight with field colonies of Argentine ants resulted in L. humile retaining possession of baits. Additional evidence for the potential importance of colony- structure variation comes from the Argentine ant's native range. At a site along the Rio de la Plata in Argentina, we found an inverse relationship between ant richness and density of L. humile (apparently a function of local differences in colony structure) in two different years of sampling.

  3. Molecular dynamics study of Ca(2+) binding loop variants of silver hake parvalbumin with aspartic acid at the "gateway" position.

    PubMed

    Fahie, Kamau; Pitts, Rebecca; Elkins, Kelly; Nelson, Donald J

    2002-04-01

    The helix-loop-helix (i.e., EF-hand) Ca(2+) ion binding motif is characteristic of a large family of high-affinity calcium ion binding proteins, including the parvalbumins, oncomodulins and calmodulins. In this work we describe a set of molecular dynamics computations on the major parvalbumin from the silver hake (SHPV-B) and on functional fragments of this protein, consisting of the first four helical regions (the ABCD fragment), and the internal helix-loop- helix region (the CD fragment). In both whole protein and protein fragments (i.e., ABCD and CD fragments), the 9th loop residue in the calcium ion binding site in the CD helix-loop-helix region (the so-called "gateway" position) has been mutated from glutamic acid to aspartic acid. Aspartic acid is one of the most common residues found at the gateway position in other (non-parvalbumin) EF- hand proteins, but has never been found at the gateway position of any parvalbumin. (Interestingly, aspartic acid does occur at the gateway position in the closely related rat and human oncomodulins.) Consistent with experimental observations, the results of our molecular dynamics simulations show that incorporation of aspartic acid at the gateway position is very disruptive to the structural integrity of the calcium ion coordination site in the whole protein. The aspartic acid mutation is somewhat less disruptive to the calcium ion coordination sites in the two parvalbumin fragments (i.e., the ABCD and CD fragments), presumably due to the higher degree of motional freedom allowable in these protein fragments. One problem associated with the E59D whole protein variant is a prohibitively close approach of the aspartate carboxyl group to the CD calcium ion observed in the energy-minimized (pre-molecular dynamics) structure. This steric situation does not emerge during energy-minimization of the wild-type protein. The damage to the structural integrity of the calcium ion coordination site in the whole protein E59D variant is

  4. Native predators living in invaded areas: responses of terrestrial amphibian species to an Argentine ant invasion.

    PubMed

    Alvarez-Blanco, Paloma; Caut, Stephane; Cerdá, Xim; Angulo, Elena

    2017-08-22

    Predator-prey interactions play a key role in the success and impacts of invasive species. However, the effects of invasive preys on native predators have been poorly studied. Here, we first reviewed hypotheses describing potential relationships between native predators and invasive preys. Second, we examined how an invasive prey, the Argentine ant (Linepithema humile), affected a native terrestrial amphibian community. In the field, we looked at the structure of the amphibian community in invaded versus uninvaded areas and characterized amphibian trophic ecology. The amphibian community sampled seemed to show a species-dependent response in abundance to invasion: adults of the natterjack toad (Bufo calamita), the species demonstrating the highest degree of ant specialization, were less abundant in invaded areas. Although available ant biomass was significantly greater in invaded than in uninvaded areas (only Argentine ants occurred in the former), amphibians consumed relatively fewer ants in invaded areas. In the lab, we quantified amphibian consumption of Argentine ants versus native ants and assessed whether consumption patterns could have been influenced by prior exposure to the invader. The lab experiments corroborated the field results: amphibians preferred native ants over Argentine ants, and prior exposure did not influence consumption. Differences in preference explained why amphibians consumed fewer Argentine ants in spite of their greater relative availability; they might also explain why the most ant-specialized amphibians seemed to avoid invaded areas. Our results suggest the importance to account for predator feeding capacities and dietary ranges to understand the effects of invasive species at higher trophic levels.

  5. The tropopause at southern extratropical latitudes: Argentine operational rawinsonde climatology

    NASA Astrophysics Data System (ADS)

    Bischoff, Susana A.; Canziani, Pablo O.; Yuchechen, Adrián E.

    2007-02-01

    Argentine operational rawinsonde records spanning a 30-year period (1968-1997) were used to study the climatology of the tropopause from the subtropics to the southern mid-latitudes, approximately along the 60°W meridian. The thermal tropopause annual cycle as well as its variability was analyzed at three sites: Resistencia (RES), Ezeiza (EZE), and Comodoro Rivadavia (CRD). Single and double tropopause observations were studied, given the comparatively frequent occurrence of double tropopause events at all three sites. The tropopause behavior at RES and CRD is distinct, whereas at EZE it shows a winter evolution similar to the one at CRD and a summer evolution closer to the one at RES, in agreement with the annual evolution of the subtropical jet. The tropopause evolution is discussed under the light of the dynamic climatology of southern South America. In the presence of double tropopause events and in terms of potential temperature, it should be noted that the upper tropopause temperature is close to the 380 K isentropic, i.e. the tropical tropopause layer. Moreover, the lower tropopause and single tropopause events are fairly close together, i.e. coincident with the lowermost stratosphere. Considering previous research and results from the present analysis, a definition of Extratropical Tropopause Layer (ExTL) is introduced in this work. It is proposed that the lowermost stratosphere should be regarded as the ExTL.

  6. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    DOE PAGES

    Hooper-Bui, L. M.; Kwok, E S.C.; Buchholz, B. A.; ...

    2015-07-03

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), butmore » dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). Moreover, the distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. The bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.« less

  7. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    SciTech Connect

    Hooper-Bui, L. M.; Kwok, E S.C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-07-03

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). Moreover, the distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. The bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  8. Insecticide transfer efficiency and lethal load in Argentine ants

    NASA Astrophysics Data System (ADS)

    Hooper-Bui, L. M.; Kwok, E. S. C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-10-01

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  9. First report of viral infections that affect argentine honeybees.

    PubMed

    Reynaldi, Francisco José; Sguazza, Guillermo Hernán; Pecoraro, Marcelo Ricardo; Tizzano, Marco Andrés; Galosi, Cecilia Mónica

    2010-12-01

    Honey is one of the most important agricultural products for export in Argentina. In fact, more than 3.5 million beehives and 50 000 beekeepers are related with this production, mainly located in Buenos Aires province. Honeybee mortality is a serious problem that beekeepers in Argentina have had to face during the last 3 years. It is known that the consequence of the complex interactions between environmental and beekeeping parameters added to the effect of different disease agents such as viruses, bacteria, fungi and parasitic mites may result in a sudden collapse of the colony. In addition, multiple viral infections are frequently detected concomitantly in bee colonies. We describe here the preliminary results of a survey of three honeybee-pathogenic viruses, acute bee paralysis viruses (ABPV), chronic bee paralysis viruses (CBPV) and Sacbrood viruses (SBV) detected during a screening of 61 apiaries located in the main honey producer province using a RT-PCR assay. This is the first molecular report of the presence of these viruses in Argentine apiaries.

  10. [Distribution of Lutzomyia longipalpis in the Argentine Mesopotamia, 2010].

    PubMed

    Salomon, Oscar D; Fernandez, Maria S; Santini, María S; Saavedra, Silvina; Montiel, Natalia; Ramos, Marina A; Rosa, Juan R; Szelag, Enrique A; Martinez, Mariela F

    2011-01-01

    The first case of visceral leishmaniasis (VL) in Argentina was reported in 2006 in Posadas, Misiones. During the summer 2008-2009 Lutzomyia longipalpis, the VL vector, and canine VL cases were already spread along the province of Corrientes. In order to know the distribution of VL risk, systematic captures of the vector were performed between February and March 2010, in 18 areas of the provinces of Entre Ríos and Corrientes, and the city of Puerto Iguazú, Misiones, with a total of 313 traps/night. We confirmed the presence of Lu. longipalpis, for the first time in Chajarí (Entre Ríos), Alvear, La Cruz, Curuzú Cuatiá and Bella Vista (Corrientes), and Puerto Iguazú (Misiones). In Santo Tome and Monte Caseros (Corrientes), where the vector had been previously reported, traps with more samples were obtained with 830 and 126 Lu. Longipalpis trap/site/night respectively. These results show that the vector of urban VL continues spreading in the Argentine territory. Simultaneously, the spread of the parasite and the resulting human VL cases are associated with the dispersion of reservoirs, infected dogs, with or without clinical symptoms or signs, due to human transit.

  11. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

    PubMed Central

    Hooper-Bui, L.M.; Kwok, E.S.C.; Buchholz, B.A.; Rust, M.K.; Eastmond, D.A.; Vogel, J.S.

    2015-01-01

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony. PMID:26504258

  12. Chemical signals associated with life inhibit necrophoresis in Argentine ants

    PubMed Central

    Choe, Dong-Hwan; Millar, Jocelyn G.; Rust, Michael K.

    2009-01-01

    One of the most conspicuous and stereotyped activities of social insects such as ants and honey bees is necrophoresis, the removal of dead colony members from the nest. Previous researchers suggested that decomposition products such as fatty acids trigger necrophoric behavior by ant workers. However, fatty acids elicit both foraging and necrophoric responses, depending on the current nest activities (e.g., feeding or nest maintenance). Furthermore, workers often carry even freshly killed workers (dead for <1 h) to refuse piles before significant decomposition has a chance to occur. Here, we show that the cuticular chemistry of Argentine ant workers, Linepithema humile, undergoes rapid changes after death. When the workers are alive or freshly killed, relatively large amounts of 2 characteristic ant-produced compounds, dolichodial and iridomyrmecin, are present on the ants' cuticle. However, these compounds disappear from the cuticle within about 1 h after death. We demonstrate how this phenomenon supports an alternative mechanism of ant necrophoresis in which the precise recognition and rapid removal of dead nestmates are elicited by the disappearance of these chemical signals associated with life. PMID:19416815

  13. BNCT for skin melanoma in extremities: updated Argentine clinical results.

    PubMed

    Menéndez, P R; Roth, B M C; Pereira, M D; Casal, M R; González, S J; Feld, D B; Santa Cruz, G A; Kessler, J; Longhino, J; Blaumann, H; Jiménez Rebagliati, R; Calzetta Larrieu, O A; Fernández, C; Nievas, S I; Liberman, S J

    2009-07-01

    As part of phase I/II melanoma BNCT clinical trial conducted in Argentina in a cooperative effort of the Argentine Atomic Energy Commission (CNEA) and the Oncology Institute Angel H. Roffo (IOAHR), 7 patients (6 female-1 male) received eight treatment sessions covering ten anatomical areas located in extremities. Mean age of the patients was 64 years (51-74). The treatments were performed between October 2003 and June 2007. All patients presented multiple subcutaneous skin metastases of melanoma and received an infusion containing approximately 14 gr/m(2) of (10)borophenyl-alanine (BPA) followed by the exposition of the area to a mixed thermal-epithermal neutron beam at the RA-6 reactor. The maximum prescribed dose to normal skin ranged from 16.5 to 24 Gy-Eq and normal tissue administered dose varied from 15.8 to 27.5 Gy-Eq. Considering evaluable nodules, 69.3% of overall response and 30.7% of no changes were seen. The toxicity was acceptable, with 3 out of 10 evaluable areas showing ulceration (30% toxicity grade 3).

  14. Insecticide Transfer Efficiency and Lethal Load in Argentine Ants.

    PubMed

    Hooper-Bui, L M; Kwok, E S C; Buchholz, B A; Rust, M K; Eastmond, D A; Vogel, J S

    2015-10-15

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of (14)C-sucrose, (14)C-hydramethylnon, and (14)C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  15. Clinical and epidemiological patterns of Argentine haemorrhagic fever

    PubMed Central

    Maiztegui, J. I.

    1975-01-01

    The epidemiology of Argentine haemorrhagic fever (AHF) is closely related to cricetine rodents acting as natural hosts of Junin virus. The endemo-epidemic area, which has increased 5 times since the disease was first recognized 15-20 years ago, is located in a densely populated region of Argentina. It has been shown that the virus of LCM is active in humans and rodents of the AHF endemic area; this demonstrates the simultaneous presence of two arenaviruses pathogenic for man in a given geographic location. The disease is characterized by haematological, renal, neurological and cardiovascular changes. Electron microscopy and immunohistochemical studies have shown cytopathic changes, characteristic intracellular virus-like particles, and antigenic determinants of Junin virus in different organs from 9 cases of AHF. No deposits of immunoglobulins or C3 were found in the kidneys; in addition, an absence of fibrinogen and C3 in the hepatocytes and of immunoglobulins in the spleen was observed. These findings suggest a direct viral pathogenic action in the human disease. Ultrastructural and immunofluorescence studies in tissues of guinea-pigs inoculated with two strains of Junin virus revealed the presence of the same types of virus-like particles and antigenic determinants of Junin virus as were encountered in the human subjects with AHF. ImagesFig. 2Fig. 3 PMID:1085212

  16. Biotic and abiotic controls of Argentine ant invasion success at local and landscape scales.

    PubMed

    Menke, S B; Fisher, R N; Jetz, W; Holway, D A

    2007-12-01

    Although the ecological success of introduced species hinges on biotic interactions and physical conditions, few experimental studies--especially on animals--have simultaneously investigated the relative importance of both types of factors. The lack of such research may stem from the common assumption that native and introduced species exhibit similar environmental tolerances. Here we combine experimental and spatial modeling approaches (1) to determine the relative importance of biotic and abiotic controls of Argentine ant (Linepithema humile) invasion success, (2) to examine how the importance of these factors changes with spatial scale in southern California (USA), and (3) to assess how Argentine ants differ from native ants in their environmental tolerances. A factorial field experiment that combined native ant removal with irrigation revealed that Argentine ants failed to invade any dry plots (even those lacking native ants) but readily invaded all moist plots. Native ants slowed the spread of Argentine ants into irrigated plots but did not prevent invasion. In areas without Argentine ants, native ant species showed variable responses to irrigation. At the landscape scale, Argentine ant occurrence was positively correlated with minimum winter temperature (but not precipitation), whereas native ant diversity increased with precipitation and was negatively correlated with minimum winter temperature. These results are of interest for several reasons. First, they demonstrate that fine-scale differences in the physical environment can eclipse biotic resistance from native competitors in determining community susceptibility to invasion. Second, our results illustrate surprising complexities with respect to how the abiotic factors limiting invasion can change with spatial scale, and third, how native and invasive species can differ in their responses to the physical environment. Idiosyncratic and scale-dependent processes complicate attempts to forecast where

  17. Combined effect of hemipteran control and liquid bait on Argentine ant populations.

    PubMed

    Brightwell, R J; Bambara, S B; Silverman, J

    2010-10-01

    The invasive Argentine ant, Linepithema humile (Mayr), has become a worldwide problem capable of inflicting significant ecological and economic injury on urban, agricultural, and natural environments. The mobility of this pest ant has long been noted, rapidly moving nests to new food resources and then away as resources are depleted. This ant, like many pest ant species, has a special affinity for honeydew excreted by phloem-feeding Hemiptera. We investigated the effect of various hemipteran control strategies on terrapin scale densities and measured their indirect effect on local Argentine ant densities and foraging effort. We then determined whether this indirect treatment strategy improved the performance of an ant bait. We predicted that Argentine ants would move nests away from trees treated for Hemiptera and then move nests back when a liquid bait was offered, followed by a decline in ant numbers due to intake of the toxicant. A horticultural oil spray and soil application of the systemic insecticide, imidacloprid, had no effect on terrapin scale numbers. However, trunk-injected dicrotophos caused a reduction in scale and a decline in local Argentine ant nest density and canopy foraging effort. We also recorded a reduction in local Argentine ant ground foraging when large amounts of liquid bait were applied, and we found no evidence that combining dicrotophos with liquid ant bait performed better than each treatment alone. We suggest that a strategy of combined hemipteran control plus application of liquid ant bait can reduce local Argentine ant densities, when both components of this system are highly efficacious.

  18. Biotic and abiotic controls of argentine ant invasion success at local and landscape scales

    USGS Publications Warehouse

    Menke, S.B.; Fisher, R.N.; Jetz, W.; Holway, D.A.

    2007-01-01

    Although the ecological success of introduced species hinges on biotic interactions and physical conditions, few experimental studies - especially on animals - have simultaneously investigated the relative importance of both types of factors. The lack of such research may stem from the common assumption that native and introduced species exhibit similar environmental tolerances. Here we combine experimental and spatial modeling approaches (1) to determine the relative importance of biotic and abiotic controls of Argentine ant (Linepithema humile) invasion success, (2) to examine how the importance of these factors changes with spatial scale in southern California (USA), and (3) to assess how Argentine ants differ from native ants in their environmental tolerances. A factorial field experiment that combined native ant removal with irrigation revealed that Argentine ants failed to invade any dry plots (even those lacking native ants) but readily invaded all moist plots. Native ants slowed the spread of Argentine ants into irrigated plots but did not prevent invasion. In areas without Argentine ants, native ant species showed variable responses to irrigation. At the landscape scale, Argentine ant occurrence was positively correlated with minimum winter temperature (but not precipitation), whereas native ant diversity increased with precipitation and was negatively correlated with minimum winter temperature. These results are of interest for several reasons. First, they demonstrate that fine-scale differences in the physical environment can eclipse biotic resistance from native competitors in determining community susceptibility to invasion. Second, our results illustrate surprising complexities with respect to how the abiotic factors limiting invasion can change with spatial scale, and third, how native and invasive species can differ in their responses to the physical environment. Idiosyncratic and scale-dependent processes complicate attempts to forecast where

  19. A mutualism with a native membracid facilitates pollinator displacement by Argentine ants.

    PubMed

    Lach, Lori

    2007-08-01

    The loss of biodiversity and associated ecosystem services are major threats posed by the spread of alien invasive species. Invasive ants are frequently associated with declines in the diversity of ground-dwelling arthropods but also may affect plants through their attraction to floral nectar and tending of hemipterans. Protea nitida is a tree native to the South African fynbos that hosts a native membracid, Beaufortiana sp., which is tended by ants. Here I compare Argentine ants (Linepithema humile) to native ants in their attraction to P. nitida inflorescences in the presence and absence of the membracid, and their effects on other floral arthropod visitors, seed set, and ovule predation. Argentine ant discovery of inflorescences increased at least 13-fold when membracids were present on the branch, whereas native ant discovery of inflorescences was only doubled by membracid presence at one site in one study year and was unaffected in the other three site-years. Excluding Argentine ants from inflorescences resulted in an increase in several arthropod taxa and potential pollinators; native ant exclusion had no positive effects. Thus the mutualism between Argentine ants and the membracid is facilitating pollinator deterrence by the ants. Though Argentine ants were not associated with a decline in P. nitida seed set or ovule predation, declines in generalist insect pollinators may have ramifications for the 83% of fynbos plants that are insect pollinated. Pitfall traps showed that Argentine ants were not more abundant than native ants in non-invaded sites. Focusing only on abundance on the ground and displacement of ground-dwelling arthropod fauna may lead to an underestimate of the effects of invasive ants on their adopted communities.

  20. Agronomic characterization of the Argentina Indicator Region. [U.S. corn belt and Argentine pampas

    NASA Technical Reports Server (NTRS)

    Hicks, D. R. (Principal Investigator)

    1982-01-01

    An overview of the Argentina indicator region including information on topography, climate, soils and vegetation is presented followed by a regionalization of crop livestock land use. Corn/soybean production and exports as well as agricultural practices are discussed. Similarities and differences in the physical agronomic scene, crop livestock land use and agricultural practices between the U.S. corn belt and the Argentine pampa are considered. The Argentine agricultural economy is described. Crop calendars for the Argentina indicator region, an accompanying description, notes on crop-livestock zones, wheat production, field size, and agricultural problems and practices are included.

  1. [The assimilation of Italians and their descendants in Argentine society (1880-1925)].

    PubMed

    Nascimbene, M C

    1996-09-01

    "The impact of massive immigration in the post-1870 period produced major changes in... Argentine society. Integration of immigrant groups (Italians, Spaniards, the French and others) was nevertheless fiercely opposed by local elites. The essay is firstly concerned with size and development of immigration flows; secondly it deals with the characteristics of local reaction against the immigrants; thirdly it reveals how, in spite of the latter, the Italians' integration did take place in the Argentine middle classes. Finally, a particular case-study is presented, in connection with integration of immigrants and their descendants in the national army." (SUMMARY IN ENG AND FRE) excerpt

  2. [Oxygen therapy during Argentine-based national and international flights].

    PubMed

    Martínez Fraga, Alejandro; Sívori, Martín; Alonso, Mariana

    2008-01-01

    There are no data about supplemental oxygen in flight in our country. The objective of our study was to evaluate arranging in-flight-oxygen required by a simulated traveler, system of administration and costs, and to compare the results between Argentine-based (A) and international (I) airlines. The questionnaire used was similar to that of Stoller et al12. Data collection consisted of telephone calls placed by one of the authors to all commercial air carriers listed in our two Buenos Aires City airports during July 2007. A structured interview with questions was addressed on issues that an oxygen-using air traveler would need to arrange in-flight oxygen. Of the 25 airlines, 6 were discarded because of lack of information (24%, three A -60%- and one I -16%-). All A allowed in-flight-oxygen vs. 80% of I (p<0.05), 100% of A and 94% of I required a medical certificate (p=NS); 71% of A and 100% of I required previous notification (p<0.05); 50% of A and 87% of I provided patient interphases of oxygen administration (p=NS). Free of charge oxygen could be provided by 100% of A and 50% of I, with airline charge between 70 to 300 dollars. In conclusion, we observed different policies, rules, availability, and a pronounced lack of standardization of airline information. The cost of oxygen was very different between airlines and it was superior on I. It will be necessary to carry out actions to facilitate patient access to oxygentherapy and to standardize medical information among airlines in our country.

  3. [Evaluation and treatment of interstitial lung disease in Argentine].

    PubMed

    Mosca, C; Quadrelli, S; Castro Zorrilla, L; Castagnino, J

    2000-01-01

    To determine the availability and usual management of interstitial lung diseases (ILD) in our country, the Section of Interstitial Lung Diseases of the Argentine Association for Respiratory Medicine (AAMR) made a survey about diagnostic methodology and treatment of ILD. A total of 115 answers were obtained (38.5%), 43% of them among physicians living in the provinces. Availability of diffusing capacity of the lung for carbon monoxide test (DLCO) is limited: 25.4% never have access to it and 35.6% can seldom use it. Availability to thoracic CT scan is wider: 85% may use if often (32.4%) or always (52.6%). Bronchoscopy is commonly available in 87.7% of the physicians either often (21.9%) or always (65.8%). However, only 20.2% perform BAL and 13.1% transbronchial biopsy in every patient. Only 16.6% perform open lung biopsy or thoracoscopic biopsy in all or most of their patients. Sixty eight percent of physicians who always have availability of DLCO perform it in every patient but only 7.1% of those who seldom have access to DLCO do so (p = 0.0003). Availability of bronchoscopy does not have any influence on the decision of performing BAL or transbronchial biopsy. Frequency of use of surgical biopsy or treatment with immunosuppressive drugs was not influenced by any variable. We conclude that there is a current trend to underuse diagnostic resources for ILD in Argentina. Limitations in availability are relevant regarding DLCO. An effort from the health authorities to centralize the management of patients with ILD would allow to study and treat them according to international recommendations.

  4. DNA barcoding identifies Argentine fishes from marine and brackish waters.

    PubMed

    Mabragaña, Ezequiel; Díaz de Astarloa, Juan Martín; Hanner, Robert; Zhang, Junbin; González Castro, Mariano

    2011-01-01

    DNA barcoding has been advanced as a promising tool to aid species identification and discovery through the use of short, standardized gene targets. Despite extensive taxonomic studies, for a variety of reasons the identification of fishes can be problematic, even for experts. DNA barcoding is proving to be a useful tool in this context. However, its broad application is impeded by the need to construct a comprehensive reference sequence library for all fish species. Here, we make a regional contribution to this grand challenge by calibrating the species discrimination efficiency of barcoding among 125 Argentine fish species, representing nearly one third of the known fauna, and examine the utility of these data to address several key taxonomic uncertainties pertaining to species in this region. Specimens were collected and morphologically identified during crusies conducted between 2005 and 2008. The standard BARCODE fragment of COI was amplified and bi-directionally sequenced from 577 specimens (mean of 5 specimens/species), and all specimens and sequence data were archived and interrogated using analytical tools available on the Barcode of Life Data System (BOLD; www.barcodinglife.org). Nearly all species exhibited discrete clusters of closely related haplogroups which permitted the discrimination of 95% of the species (i.e. 119/125) examined while cases of shared haplotypes were detected among just three species-pairs. Notably, barcoding aided the identification of a new species of skate, Dipturus argentinensis, permitted the recognition of Genypterus brasiliensis as a valid species and questions the generic assignment of Paralichthys isosceles. This study constitutes a significant contribution to the global barcode reference sequence library for fishes and demonstrates the utility of barcoding for regional species identification. As an independent assessment of alpha taxonomy, barcodes provide robust support for most morphologically based taxon concepts and

  5. DNA Barcoding Identifies Argentine Fishes from Marine and Brackish Waters

    PubMed Central

    Mabragaña, Ezequiel; Díaz de Astarloa, Juan Martín; Hanner, Robert; Zhang, Junbin; González Castro, Mariano

    2011-01-01

    Background DNA barcoding has been advanced as a promising tool to aid species identification and discovery through the use of short, standardized gene targets. Despite extensive taxonomic studies, for a variety of reasons the identification of fishes can be problematic, even for experts. DNA barcoding is proving to be a useful tool in this context. However, its broad application is impeded by the need to construct a comprehensive reference sequence library for all fish species. Here, we make a regional contribution to this grand challenge by calibrating the species discrimination efficiency of barcoding among 125 Argentine fish species, representing nearly one third of the known fauna, and examine the utility of these data to address several key taxonomic uncertainties pertaining to species in this region. Methodology/Principal Findings Specimens were collected and morphologically identified during crusies conducted between 2005 and 2008. The standard BARCODE fragment of COI was amplified and bi-directionally sequenced from 577 specimens (mean of 5 specimens/species), and all specimens and sequence data were archived and interrogated using analytical tools available on the Barcode of Life Data System (BOLD; www.barcodinglife.org). Nearly all species exhibited discrete clusters of closely related haplogroups which permitted the discrimination of 95% of the species (i.e. 119/125) examined while cases of shared haplotypes were detected among just three species-pairs. Notably, barcoding aided the identification of a new species of skate, Dipturus argentinensis, permitted the recognition of Genypterus brasiliensis as a valid species and questions the generic assignment of Paralichthys isosceles. Conclusions/Significance This study constitutes a significant contribution to the global barcode reference sequence library for fishes and demonstrates the utility of barcoding for regional species identification. As an independent assessment of alpha taxonomy, barcodes provide

  6. Effects of honeydew-producing hemipteran denial on local argentine ant distribution and boric acid bait performance.

    PubMed

    Brightwell, R J; Silverman, J

    2009-06-01

    The Argentine ant is well known for its affinity for honeydew and is often associated with hemipteran outbreaks in agricultural and urban environments. It has been suggested that Argentine ants may be controlled by restricting access to honeydew, thereby forcing the ants to move or by encouraging increased liquid toxicant intake. We tested this possible control strategy by restricting Argentine ant access to the honeydew-producing terrapin scale within the canopy of red maple trees and monitoring ant numbers with pitfall traps and nest counts in the mulch around the tree base. Argentine ant nest numbers fell dramatically in the mulch around ant-excluded trees; however, there was no reduction in Argentine ant numbers caught in pitfalls around trees with or without canopy access. We added 0.5% boric acid bait stations at the base of the red maples and monitored bait consumption. Pitfall and nest counts were not affected by the addition of boric acid, although bait consumption was lower around ant-excluded trees, suggesting that restricting access to honeydew-producing Hemiptera did not enhance bait performance. We attribute this result to the increased distance Argentine ant workers had to trail from nest to bait station when not tending nearby terrapin scale. We suggest an alternative management strategy concentrating direct insecticidal control of Argentine ants around a few host plants infested with honeydew-producing Hemiptera by controlling Hemiptera in nearby host plants.

  7. Behavioural and chemical evidence for multiple colonisation of the Argentine ant, Linepithema humile, in the Western Cape, South Africa

    PubMed Central

    2011-01-01

    Background The Argentine ant, Linepithema humile, is a widespread invasive ant species that has successfully established in nearly all continents across the globe. Argentine ants are characterised by a social structure known as unicoloniality, where territorial boundaries between nests are absent and intraspecific aggression is rare. This is particularly pronounced in introduced populations and results in the formation of large and spatially expansive supercolonies. Although it is amongst the most well studied of invasive ants, very little work has been done on this ant in South Africa. In this first study, we investigate the population structure of Argentine ants in South Africa. We use behavioural (aggression tests) and chemical (CHC) approaches to investigate the population structure of Argentine ants within the Western Cape, identify the number of supercolonies and infer number of introductions. Results Both the aggression assays and chemical data revealed that the Western Cape Argentine ant population can be divided into two behaviourally and chemically distinct supercolonies. Intraspecific aggression was evident between the two supercolonies of Argentine ants with ants able to discriminate among conspecific non-nestmates. This discrimination is linked to the divergence in cuticular hydrocarbon profiles of ants originating from the two supercolonies. Conclusions The presence of these two distinct supercolonies is suggestive of at least two independent introductions of this ant within the Western Cape. Moreover, the pattern of colonisation observed in this study, with the two colonies interspersed, is in agreement with global patterns of Argentine ant invasions. Our findings are of interest because recent studies show that Argentine ants from South Africa are different from those identified in other introduced ranges and therefore provide an opportunity to further understand factors that determine the distributional and spread patterns of Argentine ant

  8. Behavioural and chemical evidence for multiple colonisation of the Argentine ant, Linepithema humile, in the Western Cape, South Africa.

    PubMed

    Mothapo, Natasha P; Wossler, Theresa C

    2011-02-03

    The Argentine ant, Linepithema humile, is a widespread invasive ant species that has successfully established in nearly all continents across the globe. Argentine ants are characterised by a social structure known as unicoloniality, where territorial boundaries between nests are absent and intraspecific aggression is rare. This is particularly pronounced in introduced populations and results in the formation of large and spatially expansive supercolonies. Although it is amongst the most well studied of invasive ants, very little work has been done on this ant in South Africa. In this first study, we investigate the population structure of Argentine ants in South Africa. We use behavioural (aggression tests) and chemical (CHC) approaches to investigate the population structure of Argentine ants within the Western Cape, identify the number of supercolonies and infer number of introductions. Both the aggression assays and chemical data revealed that the Western Cape Argentine ant population can be divided into two behaviourally and chemically distinct supercolonies. Intraspecific aggression was evident between the two supercolonies of Argentine ants with ants able to discriminate among conspecific non-nestmates. This discrimination is linked to the divergence in cuticular hydrocarbon profiles of ants originating from the two supercolonies. The presence of these two distinct supercolonies is suggestive of at least two independent introductions of this ant within the Western Cape. Moreover, the pattern of colonisation observed in this study, with the two colonies interspersed, is in agreement with global patterns of Argentine ant invasions. Our findings are of interest because recent studies show that Argentine ants from South Africa are different from those identified in other introduced ranges and therefore provide an opportunity to further understand factors that determine the distributional and spread patterns of Argentine ant supercolonies.

  9. Evaluation of various infused cryoprotective ingredients for their freeze-thaw stabilizing and texture improving properties in frozen red hake muscle.

    PubMed

    Bigelow, W; Lee, C M

    2007-01-01

    Various cryoprotective ingredients were evaluated for their freeze-thaw stabilizing and texture improving properties during 6-mo frozen storage when red hake (Urophycis chuss) fillets were injected with sorbitol-sodium tripolyphosphate (STPP) (40% to 60% : 3%), 1.5% alginate, or 0.75% alginate with soy protein isolate (SPI)-sorbitol-STPP (5% to 10% : 40% : 3%). Injection of 10% SPI, 1.5% alginate, or 0.75% alginate-5% SPI effectively improved water binding and retarded the freeze-induced texture changes when drip and cooking loss, centrifugal expressible moisture, protein extractability, SDS-PAGE profile, and Instron and sensory texture were assessed. The sorbitol and STPP combination was not as effective as alginate and SPI. Freeze-susceptible whitefish can be injected with proper cryoprotective ingredients for improved frozen storability.

  10. Brazilian-Argentine Relations in the 1980s: from Wary Rivalry toward Friendly Competition

    DTIC Science & Technology

    1985-03-01

    mundo: entre la politica exterior esquizofre/nica y la poltica exterior independiente (Buenos Aires: El Cid Editor, 1983). 5 Wayne A. Selcher...Moneta, ed. Geopolftica y politica del poder en el Atlantico Sur (Buenos Aires: ?leamar, 1983), p. 29. 3Nuances of positive and negative Argentine images

  11. Argentine Hydrellia Robineau-Desvoidy (Diptera, Ephydridae): new species and key to identification.

    PubMed

    Rodrigues Júnior, Francisco De Assis; Mathis, Wayne Nielsen; Hauser, Martin

    2015-05-13

    Hydrellia egeriae sp. nov., a new species of Hydrellia from Campana (34 14' 04 S, 58 52' 32 W) and Hurlingham (3435'14 S, 5838'27 W), Buenos Aires province, Argentina is described. A key to the Argentine Hydrellia species is presented.

  12. "Capaz" and "Quizás" in Argentine Spanish: Epistemic Adverbs with Mood Variability

    ERIC Educational Resources Information Center

    Yelin, Boris; Czerwionka, Lori

    2017-01-01

    This article explores the use of two epistemic adverbs in Argentine Spanish, "quizás" and "capaz". While scholars have noted the existence of "capaz" as an epistemic adverb, it had not been systematically studied prior to this investigation. To examine the epistemic stance of the adverbs, 117 participants completed an…

  13. English as an Instrumental Language: Language Displacement in the Anglo-Argentine Community.

    ERIC Educational Resources Information Center

    Cortes-Conde, Florencia

    1994-01-01

    Surveyed 99 Anglo-Argentine students aged 10 through 18 at five Spanish-English bilingual schools in Buenos Aires about their language attitudes and usage. It found that, despite the prestige of the English language, Spanish had become the dominant language for most. Age and place of residency in Buenos Aires also had a significant effect on…

  14. Self-Assessment of Governance Teams in an Argentine Private University: Adapting to Difficult Times

    ERIC Educational Resources Information Center

    Durand, Julio; Pujadas, Carlos

    2004-01-01

    Argentine Universities like similar institutions all around the world are facing a complex and challenging environment that demands a more sophisticated leadership and the development of complex managerial skills. In this paper we propose that enhancing the quality of collective decision making, and building more complex teams as a way to preserve…

  15. Library Networks in Less-Developed Countries: Two Argentine Cases and Some Observations.

    ERIC Educational Resources Information Center

    Tang, Donna Taxco

    As an American Library Association/USIA International Library Fellow in Argentina from March to September 1989, the author worked with the Argentine National Protective Commission for People's Libraries. Included in her assignment was a charge "to assist in the development of a popular libraries network in Patagonia," the southernmost…

  16. Schooling and Governance: Pedagogical Knowledge and Bureaucratic Expertise in the Genesis of the Argentine Educational System

    ERIC Educational Resources Information Center

    Southwell, Myriam

    2013-01-01

    The consolidation of the Argentine Federal Government by the 1870s aimed to modernise local society, establish state institutions and reach political stabilisation. Building a modern schooling system articulated both utopia and bureaucracy by establishing the use of knowledge as an instrument of social intervention, vindicating and legitimising…

  17. Schooling and Governance: Pedagogical Knowledge and Bureaucratic Expertise in the Genesis of the Argentine Educational System

    ERIC Educational Resources Information Center

    Southwell, Myriam

    2013-01-01

    The consolidation of the Argentine Federal Government by the 1870s aimed to modernise local society, establish state institutions and reach political stabilisation. Building a modern schooling system articulated both utopia and bureaucracy by establishing the use of knowledge as an instrument of social intervention, vindicating and legitimising…

  18. Development of a Pheromone-Assisted Baiting Technique for Argentine Ants (Hymenoptera: Formicidae).

    PubMed

    Welzel, Kevin F; Choe, Dong-Hwan

    2016-02-24

    Current control measures for Argentine ants, Linepithema humile (Mayr), in urban settings typically include perimeter applications of insecticides around structures, resulting in potential problems with insecticide runoff and environmental contamination. Insecticidal baits can be an effective alternative to perimeter spray applications and are largely considered target-specific with minimal nontarget impact and environmental contamination. We report a "pheromone-assisted baiting technique" as an economically viable approach to maximize the efficacy of conventional baits targeting Argentine ants. Laboratory experiments with a commercially available gel bait indicated that foraging activity and final mortality of Argentine ants were significantly improved by incorporating (Z)-9-hexadecenal in the bait. The field study demonstrated that the pheromone-treated gel bait achieved a 74% reduction in Argentine ant activity by the end of 4 wk when it was compared with its own pretreatment value. This was a significant improvement over the untreated gel bait that provided a 42% reduction over the same period of time. The pheromone-assisted baiting technique has the potential in providing effective ant control with reduced amount of insecticides applied in the environment. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Draft genome of the globally widespread and invasive Argentine ant (Linepithema humile).

    PubMed

    Smith, Christopher D; Zimin, Aleksey; Holt, Carson; Abouheif, Ehab; Benton, Richard; Cash, Elizabeth; Croset, Vincent; Currie, Cameron R; Elhaik, Eran; Elsik, Christine G; Fave, Marie-Julie; Fernandes, Vilaiwan; Gadau, Jürgen; Gibson, Joshua D; Graur, Dan; Grubbs, Kirk J; Hagen, Darren E; Helmkampf, Martin; Holley, Jo-Anne; Hu, Hao; Viniegra, Ana Sofia Ibarraran; Johnson, Brian R; Johnson, Reed M; Khila, Abderrahman; Kim, Jay W; Laird, Joseph; Mathis, Kaitlyn A; Moeller, Joseph A; Muñoz-Torres, Monica C; Murphy, Marguerite C; Nakamura, Rin; Nigam, Surabhi; Overson, Rick P; Placek, Jennifer E; Rajakumar, Rajendhran; Reese, Justin T; Robertson, Hugh M; Smith, Chris R; Suarez, Andrew V; Suen, Garret; Suhr, Elissa L; Tao, Shu; Torres, Candice W; van Wilgenburg, Ellen; Viljakainen, Lumi; Walden, Kimberly K O; Wild, Alexander L; Yandell, Mark; Yorke, James A; Tsutsui, Neil D

    2011-04-05

    Ants are some of the most abundant and familiar animals on Earth, and they play vital roles in most terrestrial ecosystems. Although all ants are eusocial, and display a variety of complex and fascinating behaviors, few genomic resources exist for them. Here, we report the draft genome sequence of a particularly widespread and well-studied species, the invasive Argentine ant (Linepithema humile), which was accomplished using a combination of 454 (Roche) and Illumina sequencing and community-based funding rather than federal grant support. Manual annotation of >1,000 genes from a variety of different gene families and functional classes reveals unique features of the Argentine ant's biology, as well as similarities to Apis mellifera and Nasonia vitripennis. Distinctive features of the Argentine ant genome include remarkable expansions of gustatory (116 genes) and odorant receptors (367 genes), an abundance of cytochrome P450 genes (>110), lineage-specific expansions of yellow/major royal jelly proteins and desaturases, and complete CpG DNA methylation and RNAi toolkits. The Argentine ant genome contains fewer immune genes than Drosophila and Tribolium, which may reflect the prominent role played by behavioral and chemical suppression of pathogens. Analysis of the ratio of observed to expected CpG nucleotides for genes in the reproductive development and apoptosis pathways suggests higher levels of methylation than in the genome overall. The resources provided by this genome sequence will offer an abundance of tools for researchers seeking to illuminate the fascinating biology of this emerging model organism.

  20. Applied Ecology and Control of Imported Fire Ants and Argentine Ants

    USDA-ARS?s Scientific Manuscript database

    The red imported fire ant, Solenopsis invicta Buren, and Argentine ant, Linepithema humile (Mayr), are invasive species that are major pests in urban, natural, and agricultural habitats. The goal of this dissertation was to study aspects the chemical sensitivity, behavior, and ecology of each specie...

  1. Draft genome of the globally widespread and invasive Argentine ant (Linepithema humile)

    PubMed Central

    Smith, Christopher D.; Zimin, Aleksey; Holt, Carson; Abouheif, Ehab; Benton, Richard; Cash, Elizabeth; Croset, Vincent; Currie, Cameron R.; Elhaik, Eran; Elsik, Christine G.; Fave, Marie-Julie; Fernandes, Vilaiwan; Gadau, Jürgen; Gibson, Joshua D.; Graur, Dan; Grubbs, Kirk J.; Hagen, Darren E.; Helmkampf, Martin; Holley, Jo-Anne; Hu, Hao; Viniegra, Ana Sofia Ibarraran; Johnson, Brian R.; Johnson, Reed M.; Khila, Abderrahman; Kim, Jay W.; Laird, Joseph; Mathis, Kaitlyn A.; Moeller, Joseph A.; Muñoz-Torres, Monica C.; Murphy, Marguerite C.; Nakamura, Rin; Nigam, Surabhi; Overson, Rick P.; Placek, Jennifer E.; Rajakumar, Rajendhran; Reese, Justin T.; Robertson, Hugh M.; Suarez, Andrew V.; Suen, Garret; Suhr, Elissa L.; Tao, Shu; Torres, Candice W.; van Wilgenburg, Ellen; Viljakainen, Lumi; Walden, Kimberly K. O.; Wild, Alexander L.; Yandell, Mark; Yorke, James A.; Tsutsui, Neil D.

    2011-01-01

    Ants are some of the most abundant and familiar animals on Earth, and they play vital roles in most terrestrial ecosystems. Although all ants are eusocial, and display a variety of complex and fascinating behaviors, few genomic resources exist for them. Here, we report the draft genome sequence of a particularly widespread and well-studied species, the invasive Argentine ant (Linepithema humile), which was accomplished using a combination of 454 (Roche) and Illumina sequencing and community-based funding rather than federal grant support. Manual annotation of >1,000 genes from a variety of different gene families and functional classes reveals unique features of the Argentine ant's biology, as well as similarities to Apis mellifera and Nasonia vitripennis. Distinctive features of the Argentine ant genome include remarkable expansions of gustatory (116 genes) and odorant receptors (367 genes), an abundance of cytochrome P450 genes (>110), lineage-specific expansions of yellow/major royal jelly proteins and desaturases, and complete CpG DNA methylation and RNAi toolkits. The Argentine ant genome contains fewer immune genes than Drosophila and Tribolium, which may reflect the prominent role played by behavioral and chemical suppression of pathogens. Analysis of the ratio of observed to expected CpG nucleotides for genes in the reproductive development and apoptosis pathways suggests higher levels of methylation than in the genome overall. The resources provided by this genome sequence will offer an abundance of tools for researchers seeking to illuminate the fascinating biology of this emerging model organism. PMID:21282631

  2. From discard ban to exemption: How can gear technology help reduce catches of undersized Nephrops and hake in the Bay of Biscay trawling fleet?

    PubMed

    Vogel, Camille; Kopp, Dorothée; Méhault, Sonia

    2017-01-15

    On January 1st, 2016, the French mixed Nephrops and hake fishery of the Grande Vasière, an area located in the Bay of Biscay, fell under the discard ban implemented as part of the new European Common Fisheries Policy. The fleet records historically high levels of discard despite numerous gear selectivity studies. Together with high discards survival, new technological solutions to minimize catches of undersized individuals could justify local exemptions from the discard ban. Our study focuses on the effects of two selective devices, a square mesh cylinder (SMC) and a grid, on the escapement of undersized individuals and discard reduction. Relative catch probability of the modified gear compared with the traditional gear was modelled using the catch comparison method. Potential losses from the commercial fraction of the catch were taken into account to assess their influence on the economic viability of fishing with the modified gears. The two devices had similar effects on undersized Nephrops escapement and on discard reduction, with median values of 26.5% and 23.6% for the SMC and of 30.4% and 21.4% for the grid, respectively. Only the grid was efficient for undersized hake, recording median values of escapement and discard reduction equal to 25.0% and 20.6%, respectively. Some loss from the commercial fraction of the catch was to be expected with both devices, which could be compensated for in the long term by the contribution of undersized individuals to the stock biomass. Our results support the use of selective gears technology as part of an integrated framework including control and management measures to mitigate the effect of the discard ban both for fishers and for the ecosystem. Further work is needed to quantify the effect of additional escapement from the gear on stock dynamics.

  3. Powerful motors: Kinship, citizenship and the transformation of the Argentine oil industry

    NASA Astrophysics Data System (ADS)

    Shever, Elana

    The privatization of the Argentine oil industry has been described as an unprecedented transfer of property, capital and control from the state to the corporate sphere, but this study demonstrates that the privatization process is better understood as a transformation of the historical configurations of oil-fueled development, political communities and human subjectivities. This dissertation probes the development of the state-led oil industry, and the shift to a corporate-led one, through an ethnography of Argentines differently positioned in relation to the global oil industry. The ethnography explores the lives of middle class oil workers and their families in Northwest Patagonia, impoverished residents of the shanty neighborhoods near the refineries in metropolitan Buenos Aires, and affluent employees of the translocal corporations operating in the Argentine oil fields. After the Introduction delineates this study's four principal interventions into anthropological scholarship, each subsequent chapter engages a particular problem that cuts across the Argentine oil fields and the anthropological theoretical fields. Chapter Two scrutinizes the historical construction of the Argentine subterritory as a "natural" space of value. Chapters Three and Four investigate the articulation of capitalist production and filial reproduction. These chapters argue that sentiment is a crucial generative force that has shaped the oil industry, company towns and worker families from the founding of the state-owned oil company in beginning of the twentieth century to its conversion into a corporate-owned one at the century's close. Chapters Five and Six examine the emergence of consumer citizenship and corporate citizenship out of Argentine neoliberalismo and its transformation of the oil industry. They argue that consumer and corporate citizenship are both reformulations of the older traditions of liberalism and Peronism. All the chapters of this dissertation illustrate that the

  4. Trophic ecology of invasive Argentine ants in their native and introduced ranges

    PubMed Central

    Tillberg, Chadwick V.; Holway, David A.; LeBrun, Edward G.; Suarez, Andrew V.

    2007-01-01

    Although the ecological effects of invasions often become obvious soon after introduced species become established, more gradual effects may take years to manifest and can thus require long-term data for quantification. We analyzed an 8-year record of stable isotope data on Argentine ants (Linepithema humile) from southern California to infer how the trophic position of this widespread invasive species changes over time as native ant species are displaced. We couple this longitudinal analysis with a biregional comparison of stable isotope data (δ15N) on ants from Argentina (native range) and California (introduced range) to quantify (i) how the trophic position of L. humile differs between native and introduced populations, and (ii) how relative trophic position as estimated by δ15N values of Argentine ants compare with those of other ants at the same site. Both long-term and biregional comparisons indicate that the Argentine ant's relative trophic position is reduced at sites with a longer history of occupation. Over the course of 8 years, the relative trophic position of L. humile remained high at the leading edge of an invasion front but declined, on average, behind the front as native ants disappeared. Relative to native populations, where L. humile is among the most carnivorous of ants, Argentine ants from California occupied lower trophic positions. These results support the hypothesis that Argentine ants shift their diet after establishment as a result of resource depletion and increasing reliance on plant-based resources, especially honeydew-producing Hemiptera. Our results demonstrate the value of long-term and biregional data in uncovering ecological effects of invasions. PMID:18093925

  5. Abiotic factors control invasion by Argentine ants at the community scale.

    PubMed

    Menke, Sean B; Holway, David A

    2006-03-01

    1. A prominent and unresolved question in ecology concerns why communities differ in their susceptibility to invasion. While studies often emphasize biotic resistance, it is less widely appreciated how the physical environment affects community vulnerability to invasion. 2. In this study we performed field experiments to test how abiotic variation directly and indirectly influences the extent to which Linepithema humile Mayr (Argentine ants) invade seasonally dry environments in southern California. 3. In controlled and replicated experiments involving drip irrigation, we demonstrate (i) that elevated levels of soil moisture increased both the abundance of Argentine ants and their ability to invade native ant communities and (ii) that cessation of irrigation caused declines in the abundance of Argentine ants and led to their withdrawal from previously occupied areas. 4. Because drip irrigation stimulated plant growth, in an additional experiment we manipulated both soil moisture and plant cover to assess the direct vs. indirect effects of added water on the abundance of L. humile. 5. Local abundance of Argentine ants increased in irrigated plots but was 38% higher in irrigated plots with plants compared to irrigated plots where plant growth was suppressed. The results of this experiment thus argue for a direct role of soil moisture in influencing Argentine ant abundance but suggest that that the indirect effects of added water may also be important. 6. Our study illustrates more generally that fine-scale variation in the physical environment can control whether communities become invaded by non-native species and suggests that an understanding of community susceptibility to invasion will be improved by a better appreciation of interactions between the biotic and abiotic environment.

  6. Trophic ecology of invasive Argentine ants in their native and introduced ranges.

    PubMed

    Tillberg, Chadwick V; Holway, David A; Lebrun, Edward G; Suarez, Andrew V

    2007-12-26

    Although the ecological effects of invasions often become obvious soon after introduced species become established, more gradual effects may take years to manifest and can thus require long-term data for quantification. We analyzed an 8-year record of stable isotope data on Argentine ants (Linepithema humile) from southern California to infer how the trophic position of this widespread invasive species changes over time as native ant species are displaced. We couple this longitudinal analysis with a biregional comparison of stable isotope data (delta(15)N) on ants from Argentina (native range) and California (introduced range) to quantify (i) how the trophic position of L. humile differs between native and introduced populations, and (ii) how relative trophic position as estimated by delta(15)N values of Argentine ants compare with those of other ants at the same site. Both long-term and biregional comparisons indicate that the Argentine ant's relative trophic position is reduced at sites with a longer history of occupation. Over the course of 8 years, the relative trophic position of L. humile remained high at the leading edge of an invasion front but declined, on average, behind the front as native ants disappeared. Relative to native populations, where L. humile is among the most carnivorous of ants, Argentine ants from California occupied lower trophic positions. These results support the hypothesis that Argentine ants shift their diet after establishment as a result of resource depletion and increasing reliance on plant-based resources, especially honeydew-producing Hemiptera. Our results demonstrate the value of long-term and biregional data in uncovering ecological effects of invasions.

  7. Argentine ant invasion associated with loblolly pines in the southeastern United States: minimal impacts but seasonally sustained.

    PubMed

    Rowles, Alexei D; Silverman, Jules

    2010-08-01

    Invasive ants are notorious for directly displacing native ant species. Although such impacts are associated with Argentine ant invasions (Linepithema humile) worldwide, impacts within natural habitat are less widely reported, particularly those affecting arboreal ant communities. Argentine ants were detected in North Carolina mixed pine-hardwood forest for the first time but were localized on and around loblolly pines (Pinus taeda), probably because of association with honeydew-producing Hemiptera. We explored the potential impacts of L. humile on arboreal and ground-foraging native ant species by comparing interspersed loblolly pines invaded and uninvaded by Argentine ants. Impacts on native ants were assessed monthly over 1 yr by counting ants in foraging trails on pine trunks and in surrounding plots using a concentric arrangement of pitfall traps at 1, 2, and 3 m from the base of each tree. Of floristics and habitat variables, higher soil moisture in invaded plots was the only difference between plot types, increasing confidence that any ant community differences were caused by Argentine ants. Overall patterns of impact were weak. Composition differed significantly between Argentine ant invaded and uninvaded trunks and pitfalls but was driven only by the presence of Argentine ants rather than any resulting compositional change in native ant species. Native ant abundance and richness were similarly unaffected by L. humile. However, the abundance of individual ant species was more variable. Although numbers of the arboreal Crematogaster ashmeadi (Myrmicinae) declined on and around invaded pines, epigeic Aphaenogaster rudis (Myrmicinae) remained the most abundant species in all plots. Argentine ant densities peaked in late summer and fall, therefore overlapping with most native ants. Unexpected was their continued presence during even the coldest months. We provide evidence that Argentine ants can invade and persist in native North Carolina forests, probably

  8. Long-term field trial to control the invasive Argentine ant (Hymenoptera: Formicidae) with synthetic trail pheromone.

    PubMed

    Nishisue, K; Sunamura, E; Tanaka, Y; Sakamoto, H; Suzuki, S; Fukumoto, T; Terayama, M; Tatsuki, S

    2010-10-01

    Previous short-term experiments showed that trail following behavior of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), can be disrupted by a high concentration of synthetic trail pheromone component (Z)-9-hexadecenal. In this study, a long-term field trial was conducted in 100-m2 plots of house gardens in an urban area of Japan to see whether the control effect on Argentine ants can be obtained by permeating synthetic trail pheromone from dispensers. The dispensers were placed in the experimental plots during the ant's active season (April-November) for 2 yr with monthly renewal. To estimate Argentine ant population density, foraging activity of Argentine ants in the study plots was monitored by monthly bait surveys. Throughout the study period, Argentine ant foraging activity was suppressed in the presence of the dispensers, presumably via trail forming inhibition. In contrast, the level of foraging activity was not different between treatment and no-treatment plots when the dispensers were temporarily removed, suggesting that treatment with pheromone dispensers did not suppress Argentine ant density in the treatment plots. Population decline may be expected with larger-scale treatment that covers a significant portion of the ant colony or with improvement in the potency of the disruptant.

  9. Effects of aromatic cedar mulch on the Argentine ant and the odorous house ant (Hymenoptera: Formicidae).

    PubMed

    Meissner, H E; Silverman, J

    2001-12-01

    In laboratory studies, the Argentine ant, Linepithema humile (Mayr), and the odorous house ant, Tapinoma sessile (Say), avoided aromatic cedar mulch as a nesting substrate. Both ant species were killed when confined with fresh aromatic cedar mulch in sealed containers. However, when confined with cedar mulch that had been aged outdoors for up to 140 d, mortality of L. humile was complete regardless of mulch age, whereas T. sessile mortality declined significantly over the mulch-aging period. Argentine ant susceptibility to aromatic cedar mulch was also greater than that of the odorous house ant when colonies were restricted to mulch in open trays. In addition, commercial aromatic cedar oil was lethal to both ant species. Our results suggest that aromatic cedar mulch may serve as an effective component of a comprehensive urban ant management program.

  10. Draft Genome Sequences of Four Enterococcus faecium Strains Isolated from Argentine Cheese

    PubMed Central

    Martino, Gabriela P.; Quintana, Ingrid M.; Espariz, Martín; Blancato, Victor S.; Gallina Nizo, Gabriel; Esteban, Luis

    2016-01-01

    We report the draft genome sequences of four Enterococcus faecium strains isolated from Argentine regional cheeses. These strains were selected based on their technological properties, i.e., their ability to produce aroma compounds (diacetyl, acetoin, and 2,3-butanediol) from citrate. The goal of our study is to provide further genetic evidence for the rational selection of enterococci strains based on their pheno- and genotype in order to be used in cheese production. PMID:26847907

  11. Survey of Argentine Health Researchers on the Use of Evidence in Policymaking

    PubMed Central

    Corluka, Adrijana; Hyder, Adnan A.; Segura, Elsa; Winch, Peter; McLean, Robert K. D.

    2015-01-01

    Objective In this study, Argentine health researchers were surveyed regarding their perceptions of facilitators and barriers to evidence-based policymaking in Argentina, as well as their publication activities, and research environment satisfaction. Methods A self-administered online survey was sent to health researchers in Argentina. The survey questions were based on a preceding qualitative study of Argentine health researchers, as well as the scientific literature. Results Of the 647 researchers that were reached, 226 accessed the survey, for a response rate of 34.9%. Over 80% of researchers surveyed had never been involved in or contributed to decision-making, while over 90% of researchers indicated they would like to be involved in the decision-making process. Decision-maker self-interest was perceived to be the driving factor in the development of health and healthcare policies. Research conducted by a research leader was seen to be the most influential factor in influencing health policy, followed by policy relevance of the research. With respect to their occupational environment, researchers rated highest and most favourably the opportunities available to present, discuss and publish research results and their ability to further their education and training. Argentine researchers surveyed demonstrated a strong interest and willingness to contribute their work and expertise to inform Argentine health policy development. Conclusion Despite Argentina’s long scientific tradition, there are relatively few institutionalized linkages between health research results and health policymaking. Based on the results of this study, the disconnect between political decision-making and the health research system, coupled with fewer opportunities for formalized or informal researcher/decision-maker interaction, contribute to the challenges in evidence informing health policymaking in Argentina. Improving personal contact and the building of relationships between

  12. The Falklands War: Understanding the Power of Context in Shaping Argentine Strategic Decisions

    DTIC Science & Technology

    2007-09-01

    culture and to a lesser extent the strength of the military polity as a constituency, that explains the Argentine defeat in the Falklands. 15...NUMBER OF PAGES 87 14. SUBJECT TERMS Falklands War, Malvinas, Argentina, Great Britain, Limited War Culture , Inter-Service Rivalry, Military...context, specifically the power of limited war culture and to a lesser extent the strength of the military polity as a constituency, that explains

  13. Vitrification Demonstration with Argentine Ion Exchange Material in the Stir-Melter

    SciTech Connect

    Cicero-Herman, C.A.

    2002-06-28

    The Savannah River Technology Center (SRTC) is investigating the viability of vitrification treatment of Argentine ion exchange material as part of a Department of Energy (DOE) - Office of Science and Technology Development Task Plan. Bench-scale studies were performed by the SRTC to define the necessary vitrification process for this material. However, the process had to be demonstrated in a melter system before vitrification could be considered a viable treatment option.

  14. Draft Genome Sequences of Four Enterococcus faecium Strains Isolated from Argentine Cheese.

    PubMed

    Martino, Gabriela P; Quintana, Ingrid M; Espariz, Martín; Blancato, Victor S; Gallina Nizo, Gabriel; Esteban, Luis; Magni, Christian

    2016-02-04

    We report the draft genome sequences of four Enterococcus faecium strains isolated from Argentine regional cheeses. These strains were selected based on their technological properties, i.e., their ability to produce aroma compounds (diacetyl, acetoin, and 2,3-butanediol) from citrate. The goal of our study is to provide further genetic evidence for the rational selection of enterococci strains based on their pheno- and genotype in order to be used in cheese production. Copyright © 2016 Martino et al.

  15. Effect of aromatic cedar mulch on Argentine ant (Hymenoptera: Formicidae) foraging activity and nest establishment.

    PubMed

    Meissner, Heike E; Silverman, Jules

    2003-06-01

    In the laboratory, Argentine ant, Linepithema humile (Mayr), mortality was positively correlated to the length of an aromatic cedar mulch section that had to be crossed before food could be reached. When ants could access food without crossing the mulch, mortality was not correlated to mulch section length. In the field, Argentine ants showed a tendency to avoid aromatic cedar mulch as a nesting substrate. In plant beds alongside buildings the number of ant nests (pockets containing brood) found was not significantly different between aromatic cedar and cypress mulch. However, when pine straw mulch around oak trees was replaced with aromatic cedar or cypress mulch, a similar number of ant nests was found in the cypress mulch as in the original pine straw, whereas numbers in aromatic cedar mulch were significantly lower. Also, fewer ants were trailing on the trees surrounded by aromatic cedar mulch compared with cypress mulch or the original pine straw. The number of ants attracted to apple jelly baits placed alongside the buildings did not differ between mulch types; neither did the number of ant trails crossing the mulch beds around the buildings. We suggest that aromatic cedar mulch may help control Argentine ants and reduce insecticide input when applied in combination with conventional control methods.

  16. [Preclinical assay of candid #1 vaccine against Argentine Hemorrhagic Fever made in Argentina].

    PubMed

    Ambrosio, Ana M; Riera, Laura M; Saavedra, María del Carmen; Sottosanti, María J

    2005-01-01

    Candid #1 vaccine against Argentine Hemorrhagic Fever produced in USA versus lots of the same vaccine made in Argentina were compared in guinea pigs regarding safety, immunogenicity and protective efficacy against a challenge with pathogenic Junin virus. Lots No Exp 3, 7A and 8A of Argentine origin as well as lot TSI 5-1-92 from USA were inoculated in guinea pigs of 250-400 g in two consecutive assays. Ten animals inoculated with saline performed as normal controls in each experiment. Parameters studied were: a) temperature; b) body weight; c) neutralizing antibodies to Junin virus; d) response to viral challenge. Animals gained weight and remained normothermic up to the challenge. Guinea pigs that received Candid #1 from any manufacturer elicited neutralizing antibodies to Junin virus (titles from 40 to 81920) and survived to challenge whilst 8/10 animals died in each control group. Data presented demonstrated that Candid #1 vaccines from USA or Argentine manufacturers were equally safe, immunogenic and protective in guinea pigs.

  17. Hydrocarbon-released nestmate aggression in the Argentine ant, Linepithema humile, following encounters with insect prey.

    PubMed

    Liang, D; Blomquist, G J; Silverman, J

    2001-07-01

    Argentine ants, Linepithema humile, were attacked by their nestmates following contact with a particular prey item, the brown-banded cockroach, Supella longipalpa. Contact with prey, as brief as 2 min, provoked nestmate aggression. Argentine ants contaminated with hydrocarbons extracted from S. longipalpa also released nestmate aggression behavior similar to that released by the whole prey item, confirming the involvement of hydrocarbons. In contrast to S. longipalpa, little or no nestmate aggression was induced by other ant prey from diverse taxa. A comparison of prey hydrocarbon profiles revealed that all hydrocarbons of S. longipalpa were very long chain components with 33 or more carbons, while other prey had either less, or none, of the very long chain hydrocarbons of 33 carbons or greater. We identified the hydrocarbons of S. longipalpa and some new groups of long chain hydrocarbons of L. humile. The majority of S. longipalpa hydrocarbons were 35 and 37 carbons in length with one to three methyl branches, and closely resembled two previously unidentified groups of compounds from L. humile of similar chain length. The hydrocarbons of S. longipalpa and L. humile were compared and their role in the Argentine ant nestmate recognition is discussed.

  18. Obstetric care for resident immigrant women in Argentina compared with Argentine women.

    PubMed

    Vetter, Courtney L; Gibbons, Luz; Bonotti, Ana; Klein, Karen; Belizán, José M; Althabe, Fernando

    2013-08-01

    To evaluate inequities in obstetric care in Argentina between women from Argentina and resident immigrants. A secondary analysis was performed using data generated from a prospective, multicenter, descriptive study conducted in 2008 that assessed perinatal care in 12 public hospitals in the city of Buenos Aires and 70 public hospitals in Buenos Aires Province. In the original study, eligible women answered questions about their obstetric history, sociodemographic characteristics, and prenatal and intrapartum care within 48hours of delivery. In the present analysis, the associations between nationality and prenatal care, intrapartum care, and perinatal outcome were determined. The study included 10898 women. The sociodemographic characteristics were similar between the groups, although the proportion of adolescents was higher among Argentines than among immigrants (20.1% versus 12.5%), whereas immigrant women were less educated (30.7% of the immigrant women reported 0-6years of education compared with 7.3% of Argentines). Likewise, there were few differences in obstetric care during pregnancy and delivery, and the pregnancy outcomes were also similar between the groups. There were few clinically significant differences in medical care between Argentine women and resident immigrant women during the prepartum and intrapartum periods. Copyright © 2013 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  19. Acclimation effects on critical and lethal thermal limits of workers of the Argentine ant, Linepithema humile.

    PubMed

    Jumbam, Keafon R; Jackson, Susan; Terblanche, John S; McGeoch, Melodie A; Chown, Steven L

    2008-06-01

    For the Argentine ant Linepithema humile, bioclimatic models often predict narrower optimal temperature ranges than those suggested by behavioural and physiological studies. Although water balance characteristics of workers of this species have been thoroughly studied, gaps exist in current understanding of its thermal limits. We investigated critical thermal minima and maxima and upper and lower lethal limits following acclimation to four temperatures (15, 20, 25, 30 degrees C; 12L:12D photoperiod) in adult workers of the Argentine ant, L. humile, collected from Stellenbosch, South Africa. At an ecologically relevant rate of temperature change of 0.05 degrees Cmin(-1), CTMax varied between 38 and 40 degrees C, and CTMin varied between 0 and 0.8 degrees C. In both cases the response to acclimation was weak. A significant time by exposure temperature interaction was found for upper and lower lethal limits, with a more pronounced effect of acclimation at longer exposure durations. Upper lethal limits varied between 37 and 44 degrees C, whilst lower lethal limits varied between -4 and -10.5 degrees C, with an acclimation effect more pronounced for upper than lower lethal limits. A thermal envelope for workers of the Argentine ant is provided, demonstrating that upper thermal limits do likely contribute to distributional limits, but that lower lethal limits and limits to activity likely do not, or at least for workers who are not exposed simultaneously to the demands of load carriage and successful foraging behaviour.

  20. The Haleakala Argentine ant project: a synthesis of past research and prospects for the future.

    USGS Publications Warehouse

    Krushelnycky, Paul; Haines, William; Loope, Lloyd; Van Gelder, Ellen

    2011-01-01

    1. The Haleakala Argentine Ant Project is an ongoing effort to study the ecology of the invasive Argentine ant in the park, and if possible to develop a strategy to control this destructive species. 2. Past research has demonstrated that the Argentine ant causes very significant impacts on native arthropods where it invades, threatening a large portion of the park’s biodiversity in subalpine shrubland and alpine aeolian ecosystems. 3. Patterns of spread over the past 30+ years indicate that the invasion process is influenced to a substantial degree by abiotic factors such as elevation, rainfall and temperature, and that the ant has not reached its potential range. Predictions of total range in the park suggest that it has only invaded a small fraction of available suitable habitat, confirming that this species is one of most serious threats to the park’s natural resources. 4. Numerous experiments have been conducted since 1994 in an attempt to develop a method for eradicating the Argentine ant at Haleakala using pesticidal ant baits. Thirty baits have been screened for attractiveness to ants in the park, and ten of these were tested for effectiveness of control in field plots. While some of these baits have been very effective in reducing numbers of ants, none has been able to eliminate all nests in experimental plots. 5. Research into a secondary management goal of ant population containment was initiated in 1996. By treating only expanding margins of the park’s two ant populations with an ant pesticide, rates of outward spread were substantially reduced in some areas. While this strategy was implemented from 1997 to 2004, it was ultimately discontinued after 2004 because of the difficulty and insufficient effectiveness of the technique. 6. In order to achieve the types of results necessary for eradication, the project would probably need to explore the possibility of developing a specialized bait, rather than relying on a commercially produced bait. An

  1. Foraging activity and dietary spectrum of the Argentine ant (Hymenoptera: Formicidae) in invaded natural areas of the northeast Iberian Peninsula.

    PubMed

    Abril, S; Oliveras, J; Gómez, C

    2007-10-01

    We analyzed the foraging activity and the dietary spectrum of the Argentine ant (Linepithema humile Mayr) and select native ants on cork oaks from Mediterranean open cork oak (Quercus suber) secondary forests. The study areas included invaded and noninvaded zones in close proximity. The Argentine ant's daily foraging activity was correlated to the abiotic factors studied, whereas the seasonal foraging activity was related not only to the variations in the average air temperature, but also to the trophic needs of the colony. Argentine ant workers focused their attention on protein foods during the queens' oviposition periods and during the larvae development phase, and on carbohydrate foods, such as honeydew, when males and workers were hatching. There were no significant differences over the entire year in the quantity of liquid food collected by the Argentine ant workers in comparison with the native ants studied. The solid diet of the Argentine ant on cork oaks is composed of insects, most of which are aphids. Our results have clear applications for control methods based on toxic baits in the invaded natural ecosystems of the Iberian Peninsula.

  2. The distribution and evolutionary history of Wolbachia infection in native and introduced populations of the invasive argentine ant (Linepithema humile).

    PubMed

    Tsutsui, Neil D; Kauppinen, Seth N; Oyafuso, Alain F; Grosberg, Richard K

    2003-11-01

    Wolbachia pipientis is a maternally transmitted bacterium that often alters the life history of its insect host to maximize transmission to subsequent generations. Here we report on the frequency and distribution of Wolbachia infection in a widespread invasive species, the Argentine ant (Linepithema humile). We screened 1175 individual Argentine ants from 89 nests on five continents and several islands, including numerous locations in both the native (South American) and introduced ranges. We detected Wolbachia in four of 11 native populations, but only one of 21 introduced populations was infected. In the Argentine ant's native range, the distribution of Wolbachia supergroups A and B was nonoverlapping. By coupling infection frequency data with behaviourally defined colony boundaries, we show that infected and uninfected colonies are often adjacent to one another, supporting the proposition that little female-mediated gene flow occurs among Argentine ant colonies. We also conduct a phylogenetic analysis, and show that the Wolbachia infecting both native and introduced populations of Argentine ants belong to two lineages that appear to be specialized on infecting New World ants. One other lineage of Wolbachia has undergone frequent, recent episodes of horizontal transmission between distantly related, introduced insect hosts.

  3. Validation of an Argentine version of Lupus Quality of Life questionnaire.

    PubMed

    Machado Escobar, M A; Yacuzzi, M S; Martinez, R N; González Lucero, L; Bellomio, V I; Santana, M; Galindo, L; Mayer, M M; Barreira, J C; Sarano, J; Gomez, G; Collado, M V; Martinez, A; Orozco, M C; Betancur, G; Dal Pra, F; Sanchez, A; Juarez, V; Lucero, E V

    2016-12-01

    To determine reproducibility and validity of an Argentine version of the Lupus Quality of Life questionnaire (LupusQoL) and to determine cut-off values in the questionnaire. One hundred and forty-seven systemic lupus erythematosus patients (American College of Rheumatology 1982/1997) were assessed from April 2014 to July 2014. Demographic and socioeconomic variables were collected, as well as SELENA/SLEDAI, Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index Score, comorbidities and treatment data. Patients completed LupusQoL-Argentine version and European Quality of Life Questionnaire (EuroQoL-5D). Internal consistency and reliability were examined. Convergent validity with EuroQoL-5D was assessed through analysis of latent classes, which established homogeneous categories from the responses of each domain of LupusQoL and for the total. Out of 147 patients, 93.2% were female, mean age 36.4 ± 11.1 years, mean disease duration 2.7 ± 9 years, mean SELENA/SLEDAI 2.7 ± 3 points. The cut-off point that defined good or bad quality of life was 0.739 for EuroQoL 5D and 63 for LupusQoL. Cut-off values for each LupusQoL domain were also defined, creating two classes in each of them. There was moderate to high concordance to classify quality of life (Kappa = 0.74, 95% confidence interval = 0.54, 0.95). The Argentine version of LupusQoL is a valid, reliable and reproducible instrument to assess quality of life. In this study, cut-off points that allow the classification of patients regarding whether they have good or bad quality of life are established for the first time. © The Author(s) 2016.

  4. Hantavirus reservoir Oligoryzomys longicaudatus spatial distribution sensitivity to climate change scenarios in Argentine Patagonia

    PubMed Central

    Carbajo, Aníbal E; Vera, Carolina; González, Paula LM

    2009-01-01

    Background Oligoryzomys longicaudatus (colilargo) is the rodent responsible for hantavirus pulmonary syndrome (HPS) in Argentine Patagonia. In past decades (1967–1998), trends of precipitation reduction and surface air temperature increase have been observed in western Patagonia. We explore how the potential distribution of the hantavirus reservoir would change under different climate change scenarios based on the observed trends. Methods Four scenarios of potential climate change were constructed using temperature and precipitation changes observed in Argentine Patagonia between 1967 and 1998: Scenario 1 assumed no change in precipitation but a temperature trend as observed; scenario 2 assumed no changes in temperature but a precipitation trend as observed; Scenario 3 included changes in both temperature and precipitation trends as observed; Scenario 4 assumed changes in both temperature and precipitation trends as observed but doubled. We used a validated spatial distribution model of O. longicaudatus as a function of temperature and precipitation. From the model probability of the rodent presence was calculated for each scenario. Results If changes in precipitation follow previous trends, the probability of the colilargo presence would fall in the HPS transmission zone of northern Patagonia. If temperature and precipitation trends remain at current levels for 60 years or double in the future 30 years, the probability of the rodent presence and the associated total area of potential distribution would diminish throughout Patagonia; the areas of potential distribution for colilargos would shift eastwards. These results suggest that future changes in Patagonia climate may lower transmission risk through a reduction in the potential distribution of the rodent reservoir. Conclusion According to our model the rates of temperature and precipitation changes observed between 1967 and 1998 may produce significant changes in the rodent distribution in an equivalent

  5. Plasticity in queen number and social structure in the invasive Argentine ant (Linepithema humile).

    PubMed

    Ingram, Krista K

    2002-10-01

    In many polygynous social insect societies, ecological factors such as habitat saturation promote high queen numbers by increasing the cost of solitary breeding. If polygyny is associated with constrained environments, queen number in colonies of invasive social insects should increase as saturation of their new habitat increases. Here I describe the variation in queen number, nestmate relatedness, and nest size along a gradient of time since colonization in an invading population of Argentine ants (Linepithema humile) in Haleakala, Hawaii. Nest densities in this population increase with distance from the leading edge of the invasion, reaching a stable density plateau approximately 80 m from the edge (> 2 years after colonization). Although the number of queens per nest in Haleakala is generally lower than previously reported for Argentine ants, there is significant variation in queen number across this population. Both the observed and effective queen numbers increase across the density gradient, and nests in the center of the population contain queen numbers three to nine times higher than those on the edge of the invasion. The number of workers per nest is correlated with queen number, and nests in the center are six times larger than nests at the edge. Microsatellite analysis of relatedness among nestmates reveals that all nests in the Haleakala population are characterized by low relatedness and have evidence of multiple reproducing queens. Relatedness values are significantly lower in nests in the center of the population, indicating that the number of reproducing queens is greater in areas of high nest density. The variation in queen number and nestmate relatedness in this study is consistent with expectations based on changes in ecological constraints during the invasion of a new habitat, suggesting that the social structure of Argentine ant populations is strongly influenced by ecological factors. Flexibility in social structure may facilitate persistence

  6. ``You are what you eat'': Diet modifies cuticular hydrocarbons and nestmate recognition in the Argentine ant, Linepithema humile

    NASA Astrophysics Data System (ADS)

    Liang, D.; Silverman, J.

    2000-10-01

    Nestmate recognition plays a key role in the behavior and evolution of social insects. We demonstrated that hydrocarbons are the chemical cues used in Argentine ant, Linepithema humile, nestmate recognition, and that these hydrocarbons can be acquired from insect prey. Consequently, Argentine ant cuticular hydrocarbon patterns reveal the same hydrocarbons present in their diet. Diet alters both the recognition cues present on the cuticular surface and the response of nestmates to this new colony odor, resulting in aggression between former nestmates reared on different insect prey.

  7. "You are what you eat": diet modifies cuticular hydrocarbons and nestmate recognition in the Argentine ant, Linepithema humile.

    PubMed

    Liang, D; Silverman, J

    2000-09-01

    Nestmate recognition plays a key role in the behavior and evolution of social insects. We demonstrated that hydrocarbons are the chemical cues used in Argentine ant, Linepithema humile, nestmate recognition, and that these hydrocarbons can be acquired from insect prey. Consequently, Argentine ant cuticular hydrocarbon patterns reveal the same hydrocarbons present in their diet. Diet alters both the recognition cues present on the cuticular surface and the response of nestmates to this new colony odor, resulting in aggression between former nestmates reared on different insect prey.

  8. Tolerance and antiviral effect of ribavirin in patients with Argentine hemorrhagic fever.

    PubMed

    Enria, D A; Briggiler, A M; Levis, S; Vallejos, D; Maiztegui, J I; Canonico, P G

    1987-07-01

    Tolerance and antiviral effect of ribavirin was studied in 6 patients with Argentine hemorrhagic fever (AHF) of more than 8 days of evolution. Administration of ribavirin resulted in a neutralization of viremia and a drop of endogenous interferon titers. The average time of death was delayed. A reversible anemia was the only adverse effect observed. From these results, we conclude that ribavirin has an antiviral effect in advanced cases of AHF, and that anemia, the only secondary reaction observed, can be easily managed. The possible beneficial effect of ribavirin during the initial days of AHF is discussed.

  9. Therapeutic Argentine Tango Dancing for People with Mild Parkinson's Disease: A Feasibility Study.

    PubMed

    Blandy, Laura M; Beevers, Winifred A; Fitzmaurice, Kerry; Morris, Meg E

    2015-01-01

    Individuals living with Parkinson's disease (PD) can experience a range of movement disorders that affect mobility and balance and increase the risk of falls. Low health-related quality of life, depression, and anxiety are more common in people with PD than age-matched comparisons. Therapeutic dance is a form of physical activity believed to facilitate movement and therapy uptake. As well as being enjoyable, dancing is thought to improve mobility, balance, and well-being in some people living with PD. The primary objective of this study was to evaluate the feasibility and safety of a 4-week Argentine tango dance program for people with PD. Six community dwelling individuals with mild to moderate PD were recruited from Parkinson's support groups, movement disorder clinics, and the PD association in Australia. To minimize falls risk, participants were required to be <75 years of age and physically independent (Hoehn and Yahr stages I-III). They were also required to speak English. Participants attended a 1-hour dance class at a dance studio twice per week for 4 weeks. A professional dance instructor led and choreographed the Argentine tango dance classes. Physiotherapists were present to assist participants during the class and served as dance partners as necessary. The primary outcome was feasibility, which was determined by measures of recruitment, adherence, attrition, safety (falls, near misses and adverse events), and resource requirements. Secondary measures included the Beck Depression Inventory and the Euroqol-5D, administered at baseline and post intervention. Therapy outcomes pre- and post-intervention were analyzed descriptively as medians and interquartile ranges and using Wilcoxon matched pair signed-rank tests. The Argentine tango dance intervention was shown to be safe, with no adverse events. Adherence to the dance program was 89%. Depression scores improved after intervention (p = 0.04). Some challenges were associated with the need to quickly

  10. In vitro antibacterial activity of Argentine folk medicinal plants against Salmonella typhi.

    PubMed

    Pérez, C; Anesini, C

    1994-08-01

    Boiling water extracts of 132 samples from 54 plant families, commonly used in Argentine folk medicine, were screened for antibacterial activity against Salmonella typhi. The agar-well diffusion method was used. A reference concentration-response curve for ampicillin was used to estimate the apparent activity of the samples. Twenty four species showed antibacterial activity. Cassia occidentalis roots, Heimia salicifolia aerial parts, Punica granatum fruit pericarp and Rosa borboniana flowers produced some of the more active extracts. Taking into account the multiple resistance of Salmonella typhi, these findings could be useful in the search for new clinically useful antimicrobials.

  11. [Abstract bodies, concrete risks: clinical devices and the health of ova donors in Argentine reproductive medicine].

    PubMed

    Ariza, Lucía

    2016-01-01

    Using a methodological perspective grounded in science and technology studies, this article analyzes two sociotechnical devices used in Argentine reproductive medicine (biostatistical measures and donation registries) with the aim of controlling both the so-called "genetic risk" arising from the use of donated ova as well as the health risks to female donors. By examining how the deployment of monitoring criteria disregards the specificity of ova donation, the article suggests that it is not the absence of control measures and clinical criteria that produces an inadequate monitoring of such risks, but rather the concrete ways in which such measures are implemented that results in potential harms to the health of female donors.

  12. A new species of Havelockia Pearson, 1903 from the Argentine Sea (Holothuroidea: Dendrochirotida: Sclerodactylidae).

    PubMed

    Martinez, Mariano I; Thandar, Ahmed S; Penchaszadeh, Pablo E

    2013-02-04

    Havelockia pegi sp. nov., is here described from shallow waters of the Argentine Sea. This new species is distinctive in the purple colouration of its tentacles, scarcity of body wall ossicles and the presence of rosette-shaped ossicles in both the introvert and the tentacles. It is not closely related to any of its congenors. This is the first record of a true sclerodactylid from Argentina. Thandarum hernandezi Martinez & Brogger, 2012, described in the family Sclerodactylidae, is now classified in the family Sclerothyonidae.

  13. Equity during an economic crisis: financing of the Argentine health system.

    PubMed

    Cavagnero, Eleonora; Bilger, Marcel

    2010-07-01

    This article analyses the redistributive effect caused by health financing and the distribution of healthcare utilization in Argentina before and during the severe 2001/2002 economic crisis. Both dramatically changed during this period: the redistributive effect became much more positive and utilization shifted from pro-poor to pro-rich. This clearly demonstrates that when utilization is contingent on financing, changes can occur rapidly; and that an integrated approach is required when monitoring equity. From a policy perspective, the Argentine health system appears vulnerable to economic downturns mainly due to high reliance on out-of-pocket payments and the strong link between health insurance and employment.

  14. Complete mitochondrial genome of the argentine ant, Linepithema humile (Hymenoptera: Formicidae).

    PubMed

    Zhao, Ezi; Bi, Guiqi; Yang, Junqing; Zhang, Zhen; Liu, Guoqiang; Du, Qingwei; Shang, Erlei

    2017-03-01

    In this study, the complete mitochondrial genome of the widespread invasive Argentine ant (Linepithema humile) was first determined. The mitochondrial genome is 16 098 bp in length, and encodes one D-loop region, two ribosomal RNA genes, 13 protein-coding genes, and 18 transfer RNA genes. Average GC content of this genome is 19.68%. nad6 and cob genes were overlapped by 4 bp. The phylogenetic tree involving 13 available closely related species further validated the new determined sequences and phylogeny of L. humile.

  15. Nutrition and interference competition have interactive effects on the behavior and performance of Argentine ants.

    PubMed

    Kay, Adam D; Zumbusch, Taylor; Heinen, Justa L; Marsh, Tom C; Holway, David A

    2010-01-01

    Food availability often influences competitive outcomes through effects on consumer growth. Although it has received less attention, food availability may also affect competition through nutritional effects on behavior. One hypothesis linking nutrition and competition in ants posits that increased access to carbohydrates favors greater investment in worker traits that underlie behavioral dominance. We tested this hypothesis by varying dietary protein:carbohydrate (P:C) ratios and levels of interspecific interference for Argentine ants (Linepithema humile), a widespread invasive species. As predicted, colonies facing interference increased patrolling more when reared on low P:C diets; this result is the first demonstration of an interactive effect of nutrition and interference on ant colonies. Several results suggest that this dietary effect on patrolling was due primarily to changes in colony size rather than worker behavior. Colonies on lower P:C diets had lower worker mortality and larger final colony sizes. Diet had little effect on per capita patrolling, and worker behavior in performance assays depended more on previous exposure to interference than on diet. Our findings indicate that dietary P:C ratios can influence Argentine ant performance in a competitive environment and suggest a mechanism by which monopolization of carbohydrate-rich resources can help invasive ants displace native ant competitors.

  16. Development of virtual bait stations to control Argentine ants (Hymenoptera: Formicidae) in environmentally sensitive habitats.

    PubMed

    Choe, Dong-Hwan; Vetter, Richard S; Rust, Michael K

    2010-10-01

    A novel bait station referred to as a virtual bait station was developed and tested against field populations of the invasive Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), at White Beach, Camp Pendleton, in Oceanside, CA. White Beach is a nesting habitat for an endangered seabird, the California least tern (Sterna antillarum browni Mearns). The beach is heavily infested with Argentine ants, one of the threats for the California least tern chicks. Conventional pest control strategies are prohibited because of the existence of the protected bird species and the site's proximity to the ocean. The bait station consisted of a polyvinyl chloride pipe that was treated on the inside with fipronil insecticide at low concentrations to obtain delayed toxicity against ants. The pipe was provisioned with an inverted bottle of 25% sucrose solution, then capped, and buried in the sand. Foraging ants crossed the treated surface to consume the sucrose solution. The delayed toxicity of fipronil deposits allowed the ants to continue foraging on the sucrose solution and to interact with their nestmates, killing them within 3-5 d after exposure. Further modification of the bait station design minimized the accumulation of dead ants in the sucrose solution, significantly improving the longevity and efficacy of the bait station. The virtual bait station exploits the foraging behavior of the ants and provides a low impact approach to control ants in environmentally sensitive habitats. It excluded all insects except ants, required only milligram quantities of toxicant, and eliminated the problem of formulating toxicants into aqueous sugar baits.

  17. Quantitative analysis of the effects of the exotic Argentine ant on seed-dispersal mutualisms

    PubMed Central

    Rodriguez-Cabal, Mariano A.; Stuble, Katharine L.; Nuñez, Martin A.; Sanders, Nathan J.

    2009-01-01

    Although it is increasingly clear that exotic invasive species affect seed-dispersal mutualisms, a synthetic examination of the effect of exotic invasive species on seed-dispersal mutualisms is lacking. Here, we review the impacts of the invasive Argentine ant (Linepithema humile) on seed dispersal. We found that sites with L. humile had 92 per cent fewer native ant seed dispersers than did sites where L. humile was absent. In addition, L. humile did not replace native seed dispersers, as rates of seed removal and seedling establishment were all lower in the presence of L. humile than in its absence. We conclude that potential shifts in plant diversity and concomitant changes in ecosystem function may be a consequence of Argentine ant invasions, as well as invasions by other ant species. Because very few studies have examined the effects of non-ant invasive species on seed-dispersal mutualisms, the prevalence of disruption of seed-dispersal mutualisms by invasive species is unclear. PMID:19465575

  18. Determination of TBT in water and sediment samples along the Argentine Atlantic coast.

    PubMed

    de Waisbaum, R G; Rodriguez, C; Nudelman, N Sbarbati

    2010-11-01

    Cases of imposex have been reported for some organisms living in areas of the Argentine Atlantic coast. Since this is one of the known effects of the anti-fouling agent tributyltin (TBT), quantitative determinations of organotins in samples of water and sediments collected from sites along the Argentine coast were carried out. Severe cases of imposex were first reported for two gastropod species living in the Mar del Plata area, and determinations of TBT in samples collected from this site gave extremely high values and showed a close correlation between the degree of imposex and TBT concentration. Recent investigations in the area have shown a significant decrease. Surveys were also conducted in sites that exhibit highly irregular coastal profiles to examine the relevance of physical environments. Alarming concentrations of TBT were determined in most of the sites where heavy boat traffic and/or marine activities occur, demonstrating the urgent need for regulations to avoid further input of TBT. Reports from other sites in South America reveal that this should be a subject of regional concern in order to avoid severe damage to the biodiversity of regional marine organisms.

  19. Potential application of Northern Argentine propolis to control some phytopathogenic bacteria.

    PubMed

    Ordóñez, R M; Zampini, I C; Moreno, M I Nieva; Isla, M I

    2011-10-20

    The antimicrobial activity of samples of Northern Argentine propolis (Tucumán, Santiago del Estero and Chaco) against phytopathogenic bacteria was assessed and the most active samples were identified. Minimal inhibitory concentration (MIC) values were determined by agar macrodilution and broth microdilution assays. Strong antibacterial activity was detected against Erwinia carotovora spp carotovora CECT 225, Pseudomonas syringae pvar tomato CECT 126, Pseudomonas corrugata CECT 124 and Xanthomonas campestris pvar vesicatoria CECT 792. The most active propolis extract (Tucumán, T1) was selected to bioguide isolation and identified for antimicrobial compound (2',4'-dihydroxychalcone). The antibacterial chalcone was more active than the propolis ethanolic extract (MIC values of 0.5-1 μg ml(-1) and 9.5-15 μg ml(-1), respectively). Phytotoxicity assays were realized and the propolis extracts did not retard germination of lettuce seeds or the growth of onion roots. Propolis solutions applied as sprays on tomato fruits infected with P. syringae reduced the severity of disease. Application of the Argentine propolis extracts diluted with water may be promising for the management of post harvest diseases of fruits. Copyright © 2010 Elsevier GmbH. All rights reserved.

  20. Argentine ants (Linepithema humile) use adaptable transportation networks to track changes in resource quality.

    PubMed

    Latty, Tanya; Holmes, Michael J; Makinson, James C; Beekman, Madeleine

    2017-02-15

    Transportation networks play a crucial role in human and animal societies. For a transportation network to be efficient, it must have adequate capacity to meet traffic demand. Network design becomes increasingly difficult in situations where traffic demand can change unexpectedly. In humans, network design is often constrained by path dependency because it is difficult to move a road once it is built. A similar issue theoretically faces pheromone-trail-laying social insects; once a trail has been laid, positive feedback makes re-routing difficult because new trails cannot compete with continually reinforced pre-existing trails. In the present study, we examined the response of Argentine ant colonies and their trail networks to variable environments where resources differ in quality and change unexpectedly. We found that Argentine ant colonies effectively tracked changes in food quality such that colonies allocated the highest proportion of foragers to the most rewarding feeder. Ant colonies maximised access to high concentration feeders by building additional trails and routes connecting the nest to the feeder. Trail networks appeared to form via a pruning process in which lower traffic trails were gradually removed from the network. At the same time, we observed several instances where new trails appear to have been built to accommodate a surge in demand. The combination of trail building when traffic demand is high and trail pruning when traffic demand is low results in a demand-driven network formation system that allows ants to monopolise multiple dynamic resources.

  1. Geographical potential of Argentine ants (Linepithema humile Mayr) in the face of global climate change.

    PubMed Central

    Roura-Pascual, Núria; Suarez, Andrew V.; Gómez, Crisanto; Pons, Pere; Touyama, Yoshifumi; Wild, Alexander L.; Peterson, A. Townsend

    2004-01-01

    Determining the spread and potential geographical distribution of invasive species is integral to making invasion biology a predictive science. We assembled a dataset of over 1000 occurrences of the Argentine ant (Linepithema humile), one of the world's worst invasive alien species. Native to central South America, Argentine ants are now found in many Mediterranean and subtropical climates around the world. We used this dataset to assess the species' potential geographical and ecological distribution, and to examine changes in its distributional potential associated with global climate change, using techniques for ecological niche modelling. Models developed were highly predictive of the species' overall range, including both the native distributional area and invaded areas worldwide. Despite its already widespread occurrence, L. humile has potential for further spread, with tropical coastal Africa and southeast Asia apparently vulnerable to invasion. Projecting ecological niche models onto four general circulation model scenarios of future (2050s) climates provided scenarios of the species' potential for distributional expansion with warming climates: generally, the species was predicted to retract its range in tropical regions, but to expand at higher latitude areas. PMID:15615677

  2. [Detection of a founder mutation in an Argentine family with hereditary non polyposis colorectal cancer].

    PubMed

    Gómez, Laura; Adi, José; Ibarra, Jorge; Roqué, María

    2010-01-01

    Hereditary non polyposis colorectal cancer (HNPCC) has been related to mutations in the DNA mismatch repair genes (MLH1, MSH2 y MSH6). Mutation detection analysis requires the complete sequencing of these genes, given the high frequency of family-specific alterations. A point mutation (2269-2270insT) in the last codon of the MLH1 gene has been detected in families from a northern region of Italy (Reggio Emilia).Given that this alteration was registered only in people from this region, it has been considered a founder mutation. In this work, we present an Argentine HNPCC family whose ancestors were natives from the Reggio Emilia, Italy, and who were carriers for this mutation. In order to detect the genetic alteration, a PCR was developed followed by a restriction enzyme incubation assay. The mutation was detected in 3 family members, two of them without clinical symptoms. The PCR/restriction enzyme methodology has been sensitive and specific for the detection of this mutation. It has allowed the performance of a pre-symptomatic genetic diagnosis in the Argentine HNPCC family, avoiding sending samples abroad. It is worth mentioning that pre-symptomatic diagnosis of hereditary cancers allows enhanced surveillance and support for the affected families when it is performed by a multidisciplinary group.

  3. Quantitative analysis of the effects of the exotic Argentine ant on seed-dispersal mutualisms.

    PubMed

    Rodriguez-Cabal, Mariano A; Stuble, Katharine L; Nuñez, Martin A; Sanders, Nathan J

    2009-08-23

    Although it is increasingly clear that exotic invasive species affect seed-dispersal mutualisms, a synthetic examination of the effect of exotic invasive species on seed-dispersal mutualisms is lacking. Here, we review the impacts of the invasive Argentine ant (Linepithema humile) on seed dispersal. We found that sites with L. humile had 92 per cent fewer native ant seed dispersers than did sites where L. humile was absent. In addition, L. humile did not replace native seed dispersers, as rates of seed removal and seedling establishment were all lower in the presence of L. humile than in its absence. We conclude that potential shifts in plant diversity and concomitant changes in ecosystem function may be a consequence of Argentine ant invasions, as well as invasions by other ant species. Because very few studies have examined the effects of non-ant invasive species on seed-dispersal mutualisms, the prevalence of disruption of seed-dispersal mutualisms by invasive species is unclear.

  4. Laboratory and Field Evaluations of Polyacrylamide Hydrogel Baits Against Argentine Ants (Hymenoptera: Formicidae).

    PubMed

    Rust, Michael K; Soeprono, Andrew; Wright, Sarajean; Greenberg, Les; Choe, Dong-Hwan; Boser, Christina L; Cory, Coleen; Hanna, Cause

    2015-06-01

    The development of effective baits to control the Argentine ant, Linepithema humile (Mayr), has been problematic because foragers prefer sweet liquids, while many toxicants are insoluble in water and liquid baits are generally difficult to deliver. The incorporation of thiamethoxam and sucrose solutions into a water-absorbing polyacrylamide hydrogel provides a unique and novel carrier and method of application for liquid baits. Formulations of thiamethoxam affected the size of the hydrogels, and sucrose solutions containing 0.0003% technical thiamethoxam provided hydrogels as large as those made with 25% sucrose solution or deionized water. Concentrations of thiamethoxam as low as 0.000075% in the hydrogels provided 50% kill of workers within 3 d in a laboratory setting. In small colony studies, baiting with 0.00015 and 0.000075% thiamethoxam hydrogels provided 100% mortality of workers and queens within 8 d. An enzyme-linked immunosorbent assay indicated that thiamethoxam was absorbed into the interior of the polyacrylamide matrix. The water loss rates of the hydrogels were dependent upon the relative humidity. Polyacrylamide hydrogels with >50% water loss were less attractive to ants. Field studies in highly infested areas indicated that concentrations of 0.0006 or 0.0018% thiamethoxam were more effective than 0.00015%. Hydrogels may provide a cost-effective alternative to providing aqueous baits to control Argentine ants. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Flexibility in nest density and social structure in invasive populations of the Argentine ant, Linepithema humile.

    PubMed

    Ingram, Krista K

    2002-12-01

    The extraordinary success of unicolonial insect invaders has renewed interest in the origins and maintenance of unicoloniality, a social system characterized by the absence of aggressive behavior between individuals of neighboring conspecific nests. In this study, I explore how traits associated with unicoloniality, particularly nest budding and the local exchange of workers between nests, vary across environments. Comparisons of nest characteristics in three introduced populations of Argentine ants, Linepithema humile, reveal considerable variation in nest density and social structure across populations. The population with the highest nest density has smaller, less productive nests and fewer queens per nest than the two populations with low nest densities. Nestmate relatedness is low in all populations, but multi-locus genotype analyses reveal that levels of connectivity vary among populations. In particular, high nest density is associated with higher levels of genotypic similarity between nests. Assignment distances in the two populations with low nest density are similar to a native population, suggesting that the amount of mixing between neighboring nests is shared among some native and introduced populations. Because the study populations are similar in age and genetic diversity, these results suggest that the social structure of L. humile populations depend on the ecological context. Understanding the patterns of expression of unicolonial traits in different environments helps to shed light on the origins of unicoloniality and to explain the success of Argentine ants as invaders.

  6. Single-stranded RNA viruses infecting the invasive Argentine ant, Linepithema humile.

    PubMed

    Gruber, Monica A M; Cooling, Meghan; Baty, James W; Buckley, Kevin; Friedlander, Anna; Quinn, Oliver; Russell, Jessica F E J; Sébastien, Alexandra; Lester, Philip J

    2017-06-12

    Social insects host a diversity of viruses. We examined New Zealand populations of the globally widely distributed invasive Argentine ant (Linepithema humile) for RNA viruses. We used metatranscriptomic analysis, which identified six potential novel viruses in the Dicistroviridae family. Of these, three contigs were confirmed by Sanger sequencing as Linepithema humile virus-1 (LHUV-1), a novel strain of Kashmir bee virus (KBV) and Black queen cell virus (BQCV), while the others were chimeric or misassembled sequences. We extended the known sequence of LHUV-1 to confirm its placement in the Dicistroviridae and categorised its relationship to closest relatives, which were all viruses infecting Hymenoptera. We examined further for known viruses by mapping our metatranscriptomic sequences to all viral genomes, and confirmed KBV, BQCV, LHUV-1 and Deformed wing virus (DWV) presence using qRT-PCR. Viral replication was confirmed for DWV, KBV and LHUV-1. Viral titers in ants were higher in the presence of honey bee hives. Argentine ants appear to host a range of' honey bee' pathogens in addition to a virus currently described only from this invasive ant. The role of these viruses in the population dynamics of the ant remain to be determined, but offer potential targets for biocontrol approaches.

  7. Geographical potential of Argentine ants (Linepithema humile Mayr) in the face of global climate change.

    PubMed

    Roura-Pascual, Núria; Suarez, Andrew V; Gómez, Crisanto; Pons, Pere; Touyama, Yoshifumi; Wild, Alexander L; Peterson, A Townsend

    2004-12-22

    Determining the spread and potential geographical distribution of invasive species is integral to making invasion biology a predictive science. We assembled a dataset of over 1000 occurrences of the Argentine ant (Linepithema humile), one of the world's worst invasive alien species. Native to central South America, Argentine ants are now found in many Mediterranean and subtropical climates around the world. We used this dataset to assess the species' potential geographical and ecological distribution, and to examine changes in its distributional potential associated with global climate change, using techniques for ecological niche modelling. Models developed were highly predictive of the species' overall range, including both the native distributional area and invaded areas worldwide. Despite its already widespread occurrence, L. humile has potential for further spread, with tropical coastal Africa and southeast Asia apparently vulnerable to invasion. Projecting ecological niche models onto four general circulation model scenarios of future (2050s) climates provided scenarios of the species' potential for distributional expansion with warming climates: generally, the species was predicted to retract its range in tropical regions, but to expand at higher latitude areas.

  8. Optimisation in a natural system: Argentine ants solve the Towers of Hanoi.

    PubMed

    Reid, Chris R; Sumpter, David J T; Beekman, Madeleine

    2011-01-01

    Natural systems are a source of inspiration for computer algorithms designed to solve optimisation problems. Yet most 'nature-inspired' algorithms take only superficial inspiration from biology, and little is known about how real biological systems solve difficult problems. Moreover, ant algorithms, neural networks and similar methods are usually applied to static problems, whereas most biological systems have evolved to perform under dynamically changing conditions. We used the Towers of Hanoi puzzle to test whether Argentine ants can solve a potentially difficult optimisation problem. We also tested whether the ants can adapt to dynamic changes in the problem. We mapped all possible solutions to the Towers of Hanoi on a single graph and converted this into a maze for the ants to solve. We show that the ants are capable of solving the Towers of Hanoi, and are able to adapt when sections of the maze are blocked off and new sections installed. The presence of exploration pheromone increased the efficiency of the resulting network and increased the ants' ability to adapt to changing conditions. Contrary to previous studies, our study shows that mass-recruiting ant species such as the Argentine ant can forage effectively in a dynamic environment. Our results also suggest that novel optimisation algorithms can benefit from stronger biological mimicry.

  9. Sea Level and Ocean Bottom Pressure Variations From Altimetry, Mercator Model and GRACE Mission in the Argentine Basin

    NASA Astrophysics Data System (ADS)

    Garcia-Garcia, D.; Boy, J.; Chao, B. F.

    2008-12-01

    Sea Level Variations (SLV) in the Argentine basin, as already observed from space altimetry missions, show one of the most prominent variances in the oceans. Here we study two major signals in the Argentine basin, the annual and submonthly SLV signals, based on altimetry, various hydrographic data, and the time-variable gravity data from the GRACE mission. We demonstrate that the annual variation is mainly driven by density variations of the water column, that is the steric-SLV. In contrast, the submonthly SLV in the form of the so- called Argentine gyre, a barotropic counterclockwise gyre with a period around 25 days, is mainly mass- induced, that is, mostly produced by mass variations in the region [Fu et al. 2000]. The Argentine gyre signal is well reproduced by the MERCATOR ocean circulation (and bottom pressure) model, unlike the annual signal. We show that now the aliased form (into monthly sampling) is also captured in the GRACE time- variable gravity data after applying appropriated filters; further study awaits higher temporal-resolution GRACE data.

  10. Differential use of the Argentine shelf by wintering adults and juveniles southern giant petrels, Macronectes giganteus, from Patagonia

    NASA Astrophysics Data System (ADS)

    Blanco, Gabriela S.; Quintana, Flavio

    2014-08-01

    To study habitat use and at-sea movements of southern giant petrels (SGP) during non-breeding period, we deployed 15 satellite transmitters (six adults, nine juveniles) at Isla Arce and Isla Gran Robredo colonies in Patagonia, Argentina. Birds were instrumented during 81.4 ± 37 days. Adult birds used 74% of the Argentine shelf concentrating mainly at the shelf break, middle shelf waters, and the surroundings of the colony. After fledging, juveniles spread to the Argentine, Uruguayan and Brazilian shelves within the South Atlantic. Adults alternated at-sea excursions (12 ± 5 days) with periods at the colony of 3 ± 0.3 days. Contrarily, juveniles moved first to the shelf break and then traveled northwards reaching the south of Brazil. There was some spatial overlap between age classes, but only during the first 30 days after juveniles had fledged; thereafter there was not overlap between the areas used by both age classes. The Argentine shelf is widely used by different species offering a suitable environment for foraging; this may be why adults SGP from Patagonian colonies spend all year-round within the Argentine shelf. The identification of used areas of non-breeding SGP fills a gap in the species knowledge contributing not only to the preservation the species, but also to the management of marine areas globally recognized as important for many other Procellariiformes.

  11. A comparison of consumer sensory acceptance and value of domestic beef steaks and steaks from a branded, Argentine beef program.

    PubMed

    Killinger, K M; Calkins, C R; Umberger, W J; Feuz, D M; Eskridge, K M

    2004-11-01

    To determine consumer sensory acceptance and value of branded, Argentine (grass-finished, aged 30+ d) and domestic (U.S. grain-finished beef, aged 9 d) strip loins were paired based on similar Warner-Bratzler shear force values (P = 0.34) and similar marbling levels (P = 0.82). Consumers in Chicago, IL, and San Francisco, CA (n = 124 per city), evaluated one pair of Argentine and domestic steaks, and had the opportunity to participate in a silent, sealed-bid auction to purchase steaks matching the taste panel samples. Consumers were categorized into three groups based on overall acceptability ratings: 1) those who found Argentine steaks more acceptable, 2) those who found domestic steaks more acceptable, and 3) those who were indifferent. Consumers rated domestic steaks higher (P < 0.05) in juiciness, tenderness, flavor, and overall acceptability. Consumers in both Chicago and San Francisco were willing to pay more (P < 0.05) for domestic steaks (0.86 dollars and 0.52 dollars per 0.45 kg, respectively). In both cities, consumers who found Argentine samples more acceptable were willing to pay more (P < 0.05) for Argentine steaks (0.74 dollars per 0.45 kg in Chicago and 1.82 dollars per 0.45 kg in San Francisco), and consumers who found domestic samples more acceptable were willing to pay more (P < 0.05) for domestic steaks (1.66 dollars per 0.45 kg in Chicago and 1.34 dollars per 0.45 kg in San Francisco). Consumers who were indifferent were willing to pay similar (P = 0.99) amounts for Argentine and domestic steaks. Although some consumers found Argentine beef more acceptable than domestic beef (19.7 and 16.5% in Chicago and San Francisco, respectively) and were willing to pay more for it, most consumers found domestic beef to be more acceptable (59.0% in Chicago and 61.5% in San Francisco) and were willing to pay more to obtain a more acceptable product.

  12. The widespread collapse of an invasive species: Argentine ants (Linepithema humile) in New Zealand.

    PubMed

    Cooling, Meghan; Hartley, Stephen; Sim, Dalice A; Lester, Philip J

    2012-06-23

    Synergies between invasive species and climate change are widely considered to be a major biodiversity threat. However, invasive species are also hypothesized to be susceptible to population collapse, as we demonstrate for a globally important invasive species in New Zealand. We observed Argentine ant populations to have collapsed in 40 per cent of surveyed sites. Populations had a mean survival time of 14.1 years (95% CI = 12.9-15.3 years). Resident ant communities had recovered or partly recovered after their collapse. Our models suggest that climate change will delay colony collapse, as increasing temperature and decreasing rainfall significantly increased their longevity, but only by a few years. Economic and environmental costs of invasive species may be small if populations collapse on their own accord.

  13. Use of remote sensing and GIS to identify Flamingo habitat in the Argentine Altiplano

    USGS Publications Warehouse

    Boyle, Susan C.; Hoffer, Roger M.; Boyle, Terence P.; Bucher, Enrique H.

    1992-01-01

    The Argentine altiplano is a remote area which has never been adequately mapped. It is an arid region with harsh climate, little vegetation, sparse population, and an average elevation of over 3,500 feet. Little is known about the large populations of three species of flamingos which nest and feed in the altiplano lakes. In a study funded by the National Geographic Society satellite data (Landsat MSS and TM data) were used to map the location of major water bodies and to analyze the spectral characteristics of the aquatic ecosystems in the altiplano. A comparison of the two images revealed dramatic changes in the size, depth, and spectral reflectance of the lakes utilized by the flamingos.

  14. Adjective checklist to assess the big five personality factors in the Argentine population.

    PubMed

    Ledesma, Rubén D; Sánchez, Roberto; Díaz-Lázaro, Carlos M

    2011-01-01

    The aim of this work was to develop an adjective checklist to assess the Big Five personality factors in the Argentine population. The new instrument was administered to pilot (n= 112), validation (n= 372), and replication (n= 309) samples. The final version of the checklist included 67 adjectives encompassing its 5 dimensions. Factor analysis results were consistent with the Five-factor model. Internal consistency of scales was very good and convergent correlations with the Big Five Inventory (BFI; John, Donahue, & Kentle, 1991) were substantial. Face validity, as evaluated by 2 independent raters, was good. Preliminary evidence of validity for the checklist is presented. Finally, the Adjective Checklist for Personality Assessment and BFI are compared, taking into consideration their psychometric properties in our cultural context. Study limitations and future research are discussed.

  15. Screening of plants used in Argentine folk medicine for antimicrobial activity.

    PubMed

    Anesini, C; Perez, C

    1993-06-01

    Screening of 132 extracts from Argentine folk-medicinal plants for antimicrobial activity has been conducted using a penicillin G resistant strain of Staphylococcus aureus, Escherichia coli and Aspergillus niger as test microorganisms. Cephazolin, ampicillin and miconazole were used as standard antibiotics and concentration-response curves were obtained using the agar-well diffusion method. Boiling water extracts of plant materials were tested and 12 species were active against Staphylococcus aureus, whereas 10 were effective against Escherichia coli and 4 against Aspergillus niger. Tabebuia impetiginosa bark, Achyrocline sp. aerials parts, Larrea divaricata leaves, Rosa borboniana flowers, Punica granatum fruit pericarp, Psidium guineense fruit pericarp, Lithrea ternifolia leaves and Allium sativum bulbs produced some of the more active extracts.

  16. Protective efficacy of a live attenuated vaccine against Argentine hemorrhagic fever. AHF Study Group.

    PubMed

    Maiztegui, J I; McKee, K T; Barrera Oro, J G; Harrison, L H; Gibbs, P H; Feuillade, M R; Enria, D A; Briggiler, A M; Levis, S C; Ambrosio, A M; Halsey, N A; Peters, C J

    1998-02-01

    Argentine hemorrhagic fever (AHF), caused by the arenavirus Junin, is a major public health problem among agricultural workers in Argentina. A prospective, randomized, double-blind, placebo-controlled, efficacy trial of Candid 1, a live attenuated Junin virus vaccine, was conducted over two consecutive epidemic seasons among 6500 male agricultural workers in the AHF-endemic region. Twenty-three men developed laboratory-confirmed AHF during the study; 22 received placebo and 1 received vaccine (vaccine efficacy 95%; 95% confidence interval [CI], 82%-99%). Three additional subjects in each group developed laboratory-confirmed Junin virus infection associated with mild illnesses that did not fulfill the clinical case definition for AHF, yielding a protective efficacy for prevention of any illness associated with Junin virus infection of 84% (95% CI, 60%-94%). No serious adverse events were attributed to vaccination. Candid 1, the first vaccine for the prevention of illness caused by an arenavirus, is safe and highly efficacious.

  17. Junin virus replication in peripheral blood mononuclear cells of patients with Argentine haemorrhagic fever.

    PubMed

    Ambrosio, M; Vallejos, A; Saavedra, C; Maiztegui, J I

    1990-02-01

    To study the relationship of Junin virus (JV) to populations of peripheral blood mononuclear cells (PBMC) from patients with Argentine Haemorrhagic Fever (AHF), blood samples were obtained during the acute period of disease and cultured as total, adherent, and non-adherent cell populations. JV was sequentially sought in these cell populations by using an Infectious Centre (IC) assay, whereas free JV in the supernatants was evaluated by plaque formation. IC were obtained in cultures of total PBMC from 8 out of 19 patients. Maximum numbers of IC showed high variation among patients, ranging from 3 to 410 IC per 10(6) viable PBMC. In contrast, IC were sporadically demonstrated in the non-adherent cell population. The release of JV into culture supernatants was detected only in total PBMC cultures, thus in the presence of macrophages. These results demonstrate that circulating monocytes (macrophages) are targets for JV replication contributing to the viral spread in the acute phase of AHF.

  18. Development and validation of an Argentine set of facial expressions of emotion.

    PubMed

    Vaiman, Marcelo; Wagner, Mónica Anna; Caicedo, Estefanía; Pereno, Germán Leandro

    2017-02-01

    Pictures of facial expressions of emotion are used in a wide range of experiments. The last decade has seen an increase in the number of studies presenting local sets of emotion stimuli. However, only a few existing sets contain pictures of Latin Americans, despite the growing attention emotion research is receiving in this region. Here we present the development and validation of the Universidad Nacional de Cordoba, Expresiones de Emociones Faciales (UNCEEF), a Facial Action Coding System (FACS)-verified set of pictures of Argentineans expressing the six basic emotions, plus neutral expressions. FACS scores, recognition rates, Hu scores, and discrimination indices are reported. Evidence of convergent validity was obtained using the Pictures of Facial Affect in an Argentine sample. However, recognition accuracy was greater for UNCEEF. The importance of local sets of emotion pictures is discussed.

  19. Basis for the implementation of digital signature in Argentine's health environment

    NASA Astrophysics Data System (ADS)

    Escobar, P. P.; Formica, M.

    2007-11-01

    The growth of telemedical applications and electronic transactions in health environments is paced by the constant technology evolution. This implies a big cultural change in traditional medicine and in hospital information systems' users which arrival is delayed, basically, by the lack of solid laws and a well defined role-based infrastructure. The use of digital signature as a mean of identification, authentication, confidentiality and non-repudiation is the most suitable tool for assuring the electronic transactions and patient's data protection. The implementation of a Public Key Infrastructure (PKI) in health environment allows for authentication, encryption and use of digital signature for assuring confidentiality and control of the movement of sensitive information. This work defines the minimum technological, legal and procedural basis for a successful PKI implementation and establishes the roles for the different actors in the chain of confidence in the public health environment of Argentine.

  20. A mathematical model of foraging in a dynamic environment by trail-laying Argentine ants.

    PubMed

    Ramsch, Kai; Reid, Chris R; Beekman, Madeleine; Middendorf, Martin

    2012-08-07

    Ants live in dynamically changing environments, where food sources become depleted and alternative sources appear. Yet most mathematical models of ant foraging assume that the ants' foraging environment is static. Here we describe a mathematical model of ant foraging in a dynamic environment. Our model attempts to explain recent empirical data on dynamic foraging in the Argentine ant Linepithema humile (Mayr). The ants are able to find the shortest path in a Towers of Hanoi maze, a complex network containing 32,768 alternative paths, even when the maze is altered dynamically. We modify existing models developed to explain ant foraging in static environments, to elucidate what possible mechanisms allow the ants to quickly adapt to changes in their foraging environment. Our results suggest that navigation of individual ants based on a combination of one pheromone deposited during foraging and directional information enables the ants to adapt their foraging trails and recreates the experimental results. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Valvulopathy consistent with endocarditis in an Argentine boa (Boa constrictor occidentalis).

    PubMed

    Wernick, Morena B; Novo-Matos, José; Ebling, Alessia; Kühn, Karolin; Ruetten, Maja; Hilbe, Monika; Howard, Judith; Chang, Rita; Prohaska, Sarah; Hatt, Jean-Michel

    2015-03-01

    An Argentine boa (Boa constrictor occidentalis) of 5 yr 7 mo of age was presented for respiratory problems and regurgitation. Radiographs revealed evidence of cardiomegaly and pneumonia. Blood smear examination revealed the presence of intracytoplasmic inclusion bodies in peripheral lymphocytes, consistent with inclusion body disease. Cultures of a tracheal wash sample resulted in growth of Ochrobactrum intermedium and Pseudomonas putida. Echocardiographic examination revealed a large vegetative lesion on the right atrioventricular valve with valvular insufficiency, a mildly dilated right atrium, and pulmonary hypertension. Postmortem examination confirmed the presence of pneumonia and bacterial endocarditis with dystrophic mineralization of the right atrioventricular valve, associated with different bacteria than those cultured from the tracheal wash. The present case is the first report of endocarditis in a boa constrictor and contributes to the rare reports of cardiac disease in snakes.

  2. The widespread collapse of an invasive species: Argentine ants (Linepithema humile) in New Zealand

    PubMed Central

    Cooling, Meghan; Hartley, Stephen; Sim, Dalice A.; Lester, Philip J.

    2012-01-01

    Synergies between invasive species and climate change are widely considered to be a major biodiversity threat. However, invasive species are also hypothesized to be susceptible to population collapse, as we demonstrate for a globally important invasive species in New Zealand. We observed Argentine ant populations to have collapsed in 40 per cent of surveyed sites. Populations had a mean survival time of 14.1 years (95% CI = 12.9–15.3 years). Resident ant communities had recovered or partly recovered after their collapse. Our models suggest that climate change will delay colony collapse, as increasing temperature and decreasing rainfall significantly increased their longevity, but only by a few years. Economic and environmental costs of invasive species may be small if populations collapse on their own accord. PMID:22130172

  3. Floral visitation by the Argentine ant reduces bee visitation and plant seed set.

    PubMed

    Hanna, Cause; Naughton, Ida; Boser, Christina; Alarcón, Ruben; Hung, Keng-Lou James; Holway, David

    2015-01-01

    Ants often visit flowers, but have only seldom been documented to provide effective pollination services. Floral visitation by ants can also compromise plant reproduction in situations where ants interfere with more effective pollinators. Introduced ants may be especially likely to reduce plant reproductive success through floral visitation, but existing experimental studies have found little support for this hypothesis. Here, we combine experimental and observational approaches to examine the importance of floral visitation by the nonnative Argentine ant (Linepithema humile) on plant species native to Santa Cruz Island, California, USA. First, we determine how L. humile affects floral visitor diversity, bee visitation rates, and levels of pollen limitation for the common, focal plant species island morning glory (Calystegia macrostegia ssp. macrostegia). Second, we assess the broader ecological consequences of floral visitation by L. humile by comparing floral visitation networks between invaded and uninvaded sites. The Argentine ant and native ants both visited island morning glory flowers, but L. humile was much more likely to behave aggressively towards other floral visitors and to be the sole floral occupant. The presence of L. humile in morning glory flowers reduced floral visitor diversity, decreased rates of bee visitation, and increased levels of pollen limitation. Network comparisons between invaded and uninvaded. sites revealed differences in both network structure and species-level attributes. In. invaded sites, floral visitors were observed on fewer plant species, ants had a higher per-plant interaction strength relative to that of other visitors, and interaction strengths between bees and plants were weaker. These results illustrate that introduced ants can negatively affect plant reproduction and potentially disrupt pollination services at an ecosystem scale.

  4. By their own devices: invasive Argentine ants have shifted diet without clear aid from symbiotic microbes.

    PubMed

    Hu, Yi; Holway, David A; Łukasik, Piotr; Chau, Linh; Kay, Adam D; LeBrun, Edward G; Miller, Katie A; Sanders, Jon G; Suarez, Andrew V; Russell, Jacob A

    2017-03-01

    The functions and compositions of symbiotic bacterial communities often correlate with host ecology. Yet cause-effect relationships and the order of symbiont vs. host change remain unclear in the face of ancient symbioses and conserved host ecology. Several groups of ants exemplify this challenge, as their low-nitrogen diets and specialized symbioses appear conserved and ancient. To address whether nitrogen-provisioning symbionts might be important in the early stages of ant trophic shifts, we studied bacteria from the Argentine ant, Linepithema humile - an invasive species that has transitioned towards greater consumption of sugar-rich, nitrogen-poor foods in parts of its introduced range. Bacteria were present at low densities in most L. humile workers, and among those yielding quality 16S rRNA amplicon sequencing data, we found just three symbionts to be common and dominant. Two, a Lactobacillus and an Acetobacteraceae species, were shared between native and introduced populations. The other, a Rickettsia, was found only in two introduced supercolonies. Across an eight-year period of trophic reduction in one introduced population, we found no change in symbionts, arguing against a relationship between natural dietary change and microbiome composition. Overall, our findings thus argue against major changes in symbiotic bacteria in association with the invasion and trophic shift of L. humile. In addition, genome content from close relatives of the identified symbionts suggests that just one can synthesize most essential amino acids; this bacterium was only modestly abundant in introduced populations, providing little support for a major role of nitrogen-provisioning symbioses in Argentine ant's dietary shift.

  5. Teófilo Tabanera, Father of the Argentine Space Program

    NASA Astrophysics Data System (ADS)

    de León, Pablo; Tabanera, Marcela; Tabanera, Marisol

    2017-08-01

    No other figure was able to organize and catalyze the seminal interest of space exploration in Argentina more than Teófilo Tabanera. Born in 1909, Tabanera showed an early interest in the possibilities of space travel and dedicated most of his life to popularize it in his country. He created the Sociedad Argentina Interplanetaria (1949), which was the first space enthusiast's organization in Latin America. Present in the first meeting of representatives of various space societies, which led to the creation of the International Astronautical Federation, Tabanera was able to bring his enthusiasm to this new organization. A prolific writer, Tabanera wrote the first books about space exploration in Spanish, and organized many courses and conferences on the subject. When the Comisión Nacional de Investigaciones Espaciales (the Argentine Space Agency) was created in 1960 by a decree of President Arturo Frondizi, Tabanera was appointed as its first administrator. There, with meager funds, he organized launch campaigns and international projects on sounding rockets. Thanks to his knowledge of the international space sector, Tabanera invited many experts to Argentina, among them Wernher von Braun and even the Apollo XI crew, just a few months after their return from the Moon. He continued his activities in the IAF (International Astronautical Federation) serving as vice president for seven terms, and was a cofounder of the International Academy of Astronautics (I.A.A.). His many contributions, both to the Argentine and international space sector, are a testimony to his undying enthusiasm and interest in space as a way of advancing humankind.

  6. Portrayals of character smoking and drinking in Argentine-, Mexican- and US-produced films.

    PubMed

    Kollath-Cattano, Christy; Abad-Vivero, Erika N; Mejia, Raul; Perez-Hernandez, Rosaura; Sargent, James D; Thrasher, James F

    2016-09-01

    The aim of this study was to assess film character portrayals of tobacco and alcohol use in US and nationally-produced films that were popular in Argentina and Mexico from 2004-2012. We performed a content analysis of these films (n=82 Argentine, 91 Mexican, and 908 US films, respectively). Chi-squares and t-tests were used to compare characteristics of characters who smoked or drank by country of movie production. Then data from all countries were pooled, and generalized estimating equation (GEE) models were used to determine independent correlates of character smoking or drinking. There were 480 major characters for Argentine-, 364 for Mexican-, and 4962 for US-produced films. Smoking prevalence among movie characters was similar to population smoking prevalence in Mexico (21%) and Argentina (26%), but about half in the US (11%), where movie product placements are restricted. Movie smoking declined over the period in all three countries. Movie alcohol prevalence was 40-50% across all countries and did not change with time. Demographic predictors of character smoking included: being male, 18 and older, having negative character valence. Movie smoking was not associated with lower SES. Predictors of character drinking included: being age 18 and older and positive character valence. Smoking and drinking predicted each other, illicit drug use, and higher scores for other risk behaviors. This suggests that policy development in Mexico and Argentina may be necessary to reduce the amount of character tobacco and alcohol use in films. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    PubMed Central

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

    2009-01-01

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

  8. Consequences of the Argentine ant, Linepithema humile (Mayr), invasion on pollination of Euphorbia characias (L.) (Euphorbiaceae)

    NASA Astrophysics Data System (ADS)

    Blancafort, Xavier; Gómez, Crisanto

    2005-07-01

    We have studied the influence of the Argentine ant, Linepithema humile, on the pollination of Euphorbia characias, a deciduous insect-pollinated shrub. The observations were made in two adjacent areas (invaded and non-invaded by L. humile) in a Mediterranean cork-oak forest. In the invaded area, L. humile has replaced most of the native ants that climb up this plant's inflorescences. Five native ant species were detected in the non-invaded areas and only one in the invaded area. The number of visitors to infested inflorescences (1.54 ± 1.86 visitors/10 min observation) was lower than in non-infested inflorescences in the invaded area (3.74 ± 4.19 visitors/10'), and in the non-invaded areas (4.16 ± 5.00 visits/10'). For several species of flower-visiting insects, no differences were detected between the time spent in the flowers and the number of flowers visited in the two areas, except for Eristalis tenax, a dipteran which visited more flowers (15.2 ± 11.1 flowers visited/10') and spent more time (9.4 ± 5.8 sec) in the non-invaded area than in the invaded area (7.8 ± 8.2 flowers visited/10' and 5.3 ± 2.1 sec, respectively). The relative representation of insect orders in the two areas was not different. A significant reduction in fruit-set and seed-set was detected in the invaded area. These results suggest that the Argentine ant may greatly affect the reproductive success of components of the Mediterranean flora.

  9. Can the Argentine ant ( Linepithema humile Mayr) replace native ants in myrmecochory?

    NASA Astrophysics Data System (ADS)

    Gómez, Crisanto; Oliveras, Jordi

    2003-04-01

    We analyse the influence of the Argentine ant ( Linepithema humile Mayr) on the seed dispersal process of the myrmecochorous plants Euphorbia characias, E. biumbellata, Genista linifolia, G. triflora, G. monspessulana and Sarothamnus arboreus. The observations were made in two study plots of Mediterranean cork-oak secondary forest (invaded and non-invaded by L. humile). The presence of L. humile implies the displacement of all native ant species that disperse seeds. Seed transports in the non-invaded zone were carried out by eight ant species. In the invaded zone, L. humile workers removed and transported seeds to the nest. In vertebrate exclusion trials, we observed the same level of seed removal in the invaded and non-invaded zones. Two findings could explain this result. Although mean time to seed localization was higher for native ants (431.7 s) than that for L. humile (150.5 s), the mean proportion of seeds transported after being detected was higher (50.1%) in non-invaded than in invaded (16.8%) zones. The proportion of seeds removed and transported into an ant nest after an ant-seed interaction had dramatically reduced from non-invaded (41.9%) to invaded (7.4%) zones. The levels of seed dispersal by ants found prior to invasion are unlikely to be maintained in invaded zones. However, total replacement of seed dispersal function is possible if contact iteration finally offers similar levels or quantities of seeds reaching the nests. The results obtained confirm that the Argentine ant invasion may affect myrmecochory dramatically in the Mediterranean biome.

  10. First finding of melanic sylvatic Triatoma infestans (Hemiptera: Reduviidae) colonies in the Argentine Chaco.

    PubMed

    Ceballos, L A; Piccinali, R V; Berkunsky, I; Kitron, U; Gürtler, R E

    2009-09-01

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

  11. Use of an ELISA for detection of antibody responses in Argentine boa constrictors (Boa constrictor occidentalis).

    PubMed

    Lock, Brad A; Green, Linda G; Jacobson, Elliott R; Klein, Paul A

    2003-04-01

    To develop mouse monoclonal and rabbit polyclonal antibodies against immunoglobulin of Argentine boa constrictors and to demonstrate the ability of these reagents to detect antibody responses in boa constrictors by use of an ELISA and western blot analysis. Two 3-year-old Argentine boa constrictors. Procedure-Boa constrictors were immunized with 2,4-dinitrophenylated bovine serum albumin (DNP-BSA). Each snake received biweekly inoculations of 250 microg of DNP-BSA (half SC, half IP) for a total of 6 inoculations followed by monthly inoculations for 3 months. Preimmune blood samples were collected. Subsequently, blood was collected immediately prior to each booster inoculation. Anti-DNP antibodies were isolated from immune plasma samples by affinity chromatography. Affinity-purified boa anti-DNP immunoglobulin was used for production of polyclonal and monoclonal antibodies. An ELISA and western blot analysis were used to monitor immune responses, for purification of boa anti-DNP immunoglobulin, and for assessment of polyclonal and monoclonal antibody specificity. A 6-fold increase in optical density (OD405) of immune boa plasma, compared with preimmune plasma, was detected by the polyclonal antibody, and a 12- and 15-fold increase was detected by monoclonal antibodies HL1787 and HL1785, respectively, between weeks 4 and 8. Results of western blot analysis confirmed anti-DNP antibody activity in immunized boa plasma and in affinity column eluates. Polyclonal and monoclonal antibodies detected specific anti-DNP antibody responses in immunized boas. Polyclonal and monoclonal antibodies recognized boa constrictor immunoglobulin. These antibodies may be useful in serologic tests to determine exposure of snakes to pathogens.

  12. A Host-Oriented Inhibitor of Junin Argentine Hemorrhagic Fever Virus Egress

    PubMed Central

    Lu, Jianhong; Han, Ziying; Liu, Yuliang; Liu, Wenbo; Lee, Michael S.; Olson, Mark A.; Ruthel, Gordon; Freedman, Bruce D.

    2014-01-01

    ABSTRACT There are currently no U.S. Food and Drug Administration (FDA)-approved vaccines or therapeutics to prevent or treat Argentine hemorrhagic fever (AHF). The causative agent of AHF is Junin virus (JUNV); a New World arenavirus classified as a National Institute of Allergy and Infectious Disease/Centers for Disease Control and Prevention category A priority pathogen. The PTAP late (L) domain motif within JUNV Z protein facilitates virion egress and transmission by recruiting host Tsg101 and other ESCRT complex proteins to promote scission of the virus particle from the plasma membrane. Here, we describe a novel compound (compound 0013) that blocks the JUNV Z-Tsg101 interaction and inhibits budding of virus-like particles (VLPs) driven by ectopic expression of the Z protein and live-attenuated JUNV Candid-1 strain in cell culture. Since inhibition of the PTAP-Tsg101 interaction inhibits JUNV egress, compound 0013 serves as a prototype therapeutic that could reduce virus dissemination and disease progression in infected individuals. Moreover, since PTAP l-domain-mediated Tsg101 recruitment is utilized by other RNA virus pathogens (e.g., Ebola virus and HIV-1), PTAP inhibitors such as compound 0013 have the potential to function as potent broad-spectrum, host-oriented antiviral drugs. IMPORTANCE There are currently no FDA-approved vaccines or therapeutics to prevent or treat Argentine hemorrhagic fever (AHF). The causative agent of AHF is Junin virus (JUNV); a New World arenavirus classified as an NIAID/CDC category A priority pathogen. Here, we describe a prototype therapeutic that blocks budding of JUNV and has the potential to function as a broad-spectrum antiviral drug. PMID:24522922

  13. A host-oriented inhibitor of Junin Argentine hemorrhagic fever virus egress.

    PubMed

    Lu, Jianhong; Han, Ziying; Liu, Yuliang; Liu, Wenbo; Lee, Michael S; Olson, Mark A; Ruthel, Gordon; Freedman, Bruce D; Harty, Ronald N

    2014-05-01

    There are currently no U.S. Food and Drug Administration (FDA)-approved vaccines or therapeutics to prevent or treat Argentine hemorrhagic fever (AHF). The causative agent of AHF is Junin virus (JUNV); a New World arenavirus classified as a National Institute of Allergy and Infectious Disease/Centers for Disease Control and Prevention category A priority pathogen. The PTAP late (L) domain motif within JUNV Z protein facilitates virion egress and transmission by recruiting host Tsg101 and other ESCRT complex proteins to promote scission of the virus particle from the plasma membrane. Here, we describe a novel compound (compound 0013) that blocks the JUNV Z-Tsg101 interaction and inhibits budding of virus-like particles (VLPs) driven by ectopic expression of the Z protein and live-attenuated JUNV Candid-1 strain in cell culture. Since inhibition of the PTAP-Tsg101 interaction inhibits JUNV egress, compound 0013 serves as a prototype therapeutic that could reduce virus dissemination and disease progression in infected individuals. Moreover, since PTAP l-domain-mediated Tsg101 recruitment is utilized by other RNA virus pathogens (e.g., Ebola virus and HIV-1), PTAP inhibitors such as compound 0013 have the potential to function as potent broad-spectrum, host-oriented antiviral drugs. There are currently no FDA-approved vaccines or therapeutics to prevent or treat Argentine hemorrhagic fever (AHF). The causative agent of AHF is Junin virus (JUNV); a New World arenavirus classified as an NIAID/CDC category A priority pathogen. Here, we describe a prototype therapeutic that blocks budding of JUNV and has the potential to function as a broad-spectrum antiviral drug.

  14. Workers select mates for queens: a possible mechanism of gene flow restriction between supercolonies of the invasive Argentine ant

    NASA Astrophysics Data System (ADS)

    Sunamura, Eiriki; Hoshizaki, Sugihiko; Sakamoto, Hironori; Fujii, Takeshi; Nishisue, Koji; Suzuki, Shun; Terayama, Mamoru; Ishikawa, Yukio; Tatsuki, Sadahiro

    2011-05-01

    Some invasive ants form large networks of mutually non-aggressive nests, i.e., supercolonies. The Argentine ant Linepithema humile forms much larger supercolonies in introduced ranges than in its native range. In both cases, it has been shown that little gene flow occurs between supercolonies of this species, though the mechanism of gene flow restriction is unknown. In this species, queens do not undertake nuptial flight, and males have to travel to foreign nests and cope with workers before gaining access to alien queens. In this study, we hypothesized that male Argentine ants receive interference from workers of alien supercolonies. To test this hypothesis, we conducted behavioral and chemical experiments using ants from two supercolonies in Japan. Workers attacked males from alien supercolonies but not those from their own supercolonies. The level of aggression against alien males was similar to that against alien workers. The frequency of severe aggression against alien males increased as the number of recipient workers increased. Cuticular hydrocarbon profiles, which serve as cues for nestmate recognition, of workers and males from the same supercolony were very similar. Workers are likely to distinguish alien males from males of their own supercolony using the profiles. It is predicted that males are subject to considerable aggression from workers when they intrude into the nests of alien supercolonies. This may be a mechanism underlying the restricted gene flow between supercolonies of Argentine ants. The Argentine ant may possess a distinctive reproductive system, where workers participate in selecting mates for their queens. We argue that the aggression of workers against alien males is a novel form of reproductive interference.

  15. Floral visitation by the Argentine ant reduces pollinator visitation and seed set in the coast barrel cactus, Ferocactus viridescens.

    PubMed

    LeVan, Katherine E; Hung, Keng-Lou James; McCann, Kyle R; Ludka, John T; Holway, David A

    2014-01-01

    Mounting evidence indicates that trade-offs between plant defense and reproduction arise not only from resource allocation but also from interactions among mutualists. Indirect costs of plant defense by ants, for example, can outweigh benefits if ants deter pollinators. Plants can dissuade ants from occupying flowers, but such arrangements may break down when novel ant partners infiltrate mutualisms. Here, we examine how floral visitation by ants affects pollination services when the invasive Argentine ant (Linepithema humile) replaces a native ant species in a food-for-protection mutualism with the coast barrel cactus (Ferocactus viridescens), which, like certain other barrel cacti, produces extrafloral nectar. We compared the effects of floral visitation by the Argentine ant with those of the most prevalent native ant species (Crematogaster californica). Compared to C. californica, the Argentine ant was present in higher numbers in flowers. Cactus bees (Diadasia spp.), the key pollinators in this system, spent less time in flowers when cacti were occupied by the Argentine ant compared to when cacti were occupied by C. californica. Presumably as a consequence of decreased duration of floral visits by Diadasia, cacti occupied by L. humile set fewer seeds per fruit and produced fewer seeds overall compared to cacti occupied by C. californica. These data illustrate the importance of mutualist identity in cases where plants balance multiple mutualisms. Moreover, as habitats become increasingly infiltrated by introduced species, the loss of native mutualists and their replacement by non-native species may alter the shape of trade-offs between plant defense and reproduction.

  16. Workers select mates for queens: a possible mechanism of gene flow restriction between supercolonies of the invasive Argentine ant.

    PubMed

    Sunamura, Eiriki; Hoshizaki, Sugihiko; Sakamoto, Hironori; Fujii, Takeshi; Nishisue, Koji; Suzuki, Shun; Terayama, Mamoru; Ishikawa, Yukio; Tatsuki, Sadahiro

    2011-05-01

    Some invasive ants form large networks of mutually non-aggressive nests, i.e., supercolonies. The Argentine ant Linepithema humile forms much larger supercolonies in introduced ranges than in its native range. In both cases, it has been shown that little gene flow occurs between supercolonies of this species, though the mechanism of gene flow restriction is unknown. In this species, queens do not undertake nuptial flight, and males have to travel to foreign nests and cope with workers before gaining access to alien queens. In this study, we hypothesized that male Argentine ants receive interference from workers of alien supercolonies. To test this hypothesis, we conducted behavioral and chemical experiments using ants from two supercolonies in Japan. Workers attacked males from alien supercolonies but not those from their own supercolonies. The level of aggression against alien males was similar to that against alien workers. The frequency of severe aggression against alien males increased as the number of recipient workers increased. Cuticular hydrocarbon profiles, which serve as cues for nestmate recognition, of workers and males from the same supercolony were very similar. Workers are likely to distinguish alien males from males of their own supercolony using the profiles. It is predicted that males are subject to considerable aggression from workers when they intrude into the nests of alien supercolonies. This may be a mechanism underlying the restricted gene flow between supercolonies of Argentine ants. The Argentine ant may possess a distinctive reproductive system, where workers participate in selecting mates for their queens. We argue that the aggression of workers against alien males is a novel form of reproductive interference.

  17. Diet-related modification of cuticular hydrocarbon profiles of the Argentine ant, Linepithema humile, diminishes intercolony aggression.

    PubMed

    Buczkowski, Grzegorz; Kumar, Ranjit; Suib, Steven L; Silverman, Jules

    2005-04-01

    Territorial boundaries between conspecific social insect colonies are maintained through a highly developed nestmate recognition system modulated by heritable and, in some instances, nonheritable cues. Argentine ants, Linepithema humile, use both genetic and environmentally derived cues to discriminate nestmates from nonnestmates. We explored the possibility that intraspecific aggression in the Argentine ant might diminish when colonies shared a common diet. After segregating recently field-collected colony pairs into high or moderate aggression categories, we examined the effect of one of three diets: two hydrocarbon-rich insect prey, Blattella germanica and Supella longipalpa, and an artificial (insect-free) diet, on the magnitude of aggression loss. Aggression diminished between colony pairs that were initially moderately aggressive. However, initially highly aggressive colony pairs maintained high levels of injurious aggression throughout the study, independent of diet type. Each diet altered the cuticular hydrocarbon profile by contributing unique, diet-specific cues. We suggest that acquisition of common exogenous nestmate recognition cues from shared food sources may diminish aggression and promote fusion in neighboring colonies of the Argentine ant.

  18. Patterns of spread in biological invasions dominated by long-distance jump dispersal: Insights from Argentine ants

    PubMed Central

    Suarez, Andrew V.; Holway, David A.; Case, Ted J.

    2001-01-01

    Invading organisms may spread through local movements (giving rise to a diffusion-like process) and by long-distance jumps, which are often human-mediated. The local spread of invading organisms has been fit with varying success to models that couple local population growth with diffusive spread, but to date no quantitative estimates exist for the relative importance of local dispersal relative to human-mediated long-distance jumps. Using a combination of literature review, museum records, and personal surveys, we reconstruct the invasion history of the Argentine ant (Linepithema humile), a widespread invasive species, at three spatial scales. Although the inherent dispersal abilities of Argentine ants are limited, in the last century, human-mediated dispersal has resulted in the establishment of this species on six continents and on many oceanic islands. Human-mediated jump dispersal has also been the primary mode of spread at a continental scale within the United States. The spread of the Argentine ant involves two discrete modes. Maximum distances spread by colonies undergoing budding reproduction averaged 150 m/year, whereas annual jump-dispersal distances averaged three orders of magnitude higher. Invasions that involve multiple dispersal processes, such as those documented here, are undoubtedly common. Detailed data on invasion dynamics are necessary to improve the predictive power of future modeling efforts. PMID:11158600

  19. Effect of temperature on the oviposition rate of Argentine ant queens (Linepithema humile Mayr) under monogynous and polygynous experimental conditions.

    PubMed

    Abril, Sílvia; Oliveras, Jordi; Gómez, Crisanto

    2008-01-01

    Data concerning the influence of temperature on a species' physiological parameters can be a useful tool for predicting its potential distribution range, but in the case of the Argentine ant, data based on its physiological needs are too scarce and incomplete to make accurate predictions of this type. In the present study, we offer new and complete data concerning the Argentine ant queen's oviposition rate under a wide range of temperatures in the laboratory. We analyzed the oviposition rate of the Argentine ant (Linepithema humile) at 12 experimental temperatures: 10, 12, 14, 16, 18, 21, 24, 26, 28, 30, 32 and 34 degrees C under monogynous conditions (one queen per nest) and three different polygynous conditions (two, four and eight queens per nest). We found that temperature affected their oviposition rate and that the effect was similar regardless of the number of queens in the nest. Egg laying was at its maximum at 28 degrees C, with variation in the upper and lower temperature limits at which oviposition took place depending on the degree of polygyny. Oviposition rates were negatively correlated with the number of queens in the nest. We also observed a marked variation in the oviposition rate of queens subjected to the same experimental conditions.

  20. Exploitative strategies of the invasive Argentine ant (Linepithema humile) and native ant species in a southern Spanish pine forest.

    PubMed

    Carpintero, S; Retana, J; Cerdá, X; Reyes-López, J; Arias de Reyna, L

    2007-10-01

    The Argentine ant, Linepithema humile (Mayr, 1868), is displacing native ant species in Doñana National Park (Spain). This paper discusses the results of experiments aimed at analyzing exploitation competition between the invading species and other ant species in a park community. The Argentine ant was found to implement several strategies favoring its success in exploitation competition: mass recruitment, use of various microhabitats (on the ground and in trees), and activity over a wide range of temperatures. Although these strategies were not exclusive to L. humile, their joint use, together with the large number of workers forming each "unicolony," conferred a clear advantage for resource exploitation. Some native species were more severely affected than others by the presence of L. humile in terms of both abundance and behavior. The worst affected species were those whose ecological characteristics were similar to those of the Argentine ant, e.g., Pheidole pallidula (Nylander, 1849); the species least affected was Cataglyphis floricola Tinaut, 1993, possibly because of its subordinate and thermophilous nature (little overlap of daily activity rhythms with the exotic species).

  1. Palaeoceanographic significance of sedimentary features at the Argentine continental margin revealed by multichannel seismic reflection data

    NASA Astrophysics Data System (ADS)

    Gruetzner, Jens; Uenzelmann-Neben, Gabriele; Franke, Dieter

    2010-05-01

    The thermohaline circulation in the Argentine Basin today is characterized by the interaction of northward flowing Antarctic water masses (Antarctic Intermediate Water, AAIW; Circumpolar Deep Water, CDW; Antarctic Bottom Water, AABW) and southward flowing North Atlantic Deep Water (NADW). The transfer of heat and energy via both AABW and NADW constitutes an important component in maintaining the global conveyor belt. We aim at a better understanding of both paths and intensity of this current system in the past by investigating an extensive (> 11000 km) set of high quality seismic reflection profiles from the Argentine continental margin. The profiles show a significant contourite system containing both erosive and depositional features that formed through the evolution of water masses and their modifications (path, physical and chemical properties) due to plate tectonic events such as the opening of the Drake Passage or the extensive emplacement of volcanic flows at the Rio Grande Rise. Overall the depositional features indicate that along slope (contour current) transport dominates over down slope (turbiditic) processes at the southern Argentine margin south of 45° S. Further to the North down slope transport was more extensive as indicated by the presence of submarine canyons crossing the slope down to a depth of ~3500 m. Here we present preliminary results from the southern part of the continental margin (42°-50° S) where we focus on a set of ~50 km wide terraces on the slope and rise separated by contouritic channels. The terraces developed over time in alternating constructional (depositional) and erosive phases. An initial age frame was developed by mapping regional reflectors and seismic units known from previous studies. The sedimentary layer between regional reflectors AR 4 and AR 5 spanning roughly the time interval from the Eocene/Oligocene boundary to the early middle Miocene is thin (0.1 - 0.4 s TWT) below the Valentine Feilberg Terrace but

  2. [Argentine migration policy and movements of the European population (1876-1925)].

    PubMed

    Devoto, F J

    1989-04-01

    This work examines changes in Argentine migration policy from 1876-1925 and the relationship between public policy and population movements. Promoting immigration from Europe as proposed in article 25 of the Argentine constitution of 1853 was 1 of the most enduring objectives of Argentina's leadership. When Law of Immigration and Colonization (Law 817) was passed by the Chamber of Senators in 1876, the flow of immigration was at its lowest point in 8 years. Many of the provisions of Law 817 had already been put into practice occasionally or systematically, but the intent to use the law to attract a far greater number of immigrants and to select qualities seen as desirable were novel elements and the principal motives of the legislation. The unstated aim of reducing the preponderance of Italian immigration from about 2/3 was not immediately achieved. Argentina's immigration policy and actions were in competition with those of other Latin American countries and with the US. Information offices for prospective immigrants were opened in the 1880s in Paris, London, Brussels, Berlin, Vienna, Bern, and New York, and in 1887 legislation was passed permitting subsidized passages on a large scale. The continued predominance of Italian immigration demonstrated the limits of government policy influence, even when large sums of money were invested. The informal network of Italian immigrants already in Argentina and the activities of interested shipping companies on the other hand played major roles in maintaining Italian immigration. The total number of immigrants and the diversity of national origins were increased by the subsidized passages, but in 1891 the combination of a financial crisis and an end to subsidized passages decisively reduced the total flow. Changes occurred in the 1890s in regional flows within countries and in the occupational composition of immigrants from agricultors to day laborers, unskilled workers, and artisans. By about 1910 the conservative elements

  3. Characterization of Argentine honeys on the basis of their mineral content and some typical quality parameters

    PubMed Central

    2014-01-01

    Background The levels of 19 elements (As, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Se, Tl, U, V, Zn) from sixteen different Argentine production sites of unifloral [eucalyptus (Eucaliptus rostrata), chilca (Baccharis salicifolia), Algarrobo (Prosopis sp.), mistol (Ziziphus mistol) and citric] and multifloral honeys were measured with the aim to test the quality of the selected samples. Typical quality parameters of honeys were also determined (pH, sugar content, moisture). Mineral elements were determined by using inductively coupled plasma mass spectrometer (ICP-MS DRC). We also evaluated the suitability of honey as a possible biomonitor of environmental pollution. Thus, the sites were classified through cluster analysis (CA) and then pattern recognition methods such as Principal Component Analysis (PCA) and discriminant analysis (DA) were applied. Results Mean values for quality parameters were: pH, 4.12 and 3.81; sugar 82.1 and 82.0 °brix; moisture, 16.90 and 17.00% for unifloral and multifloral honeys respectively. The water content showed good maturity. Likewise, the other parameters confirmed the good quality of the honeys analysed. Potassium was quantitatively the most abundant metal, accounting for 92,5% of the total metal contents with an average concentration of 832.0 and 816.2 μg g-1 for unifloral and multifloral honeys respectively. Sodium was the second most abundant major metal in honeys with a mean value of 32.16 and 33.19 μg g-1 for unifloral and multifloral honeys respectively. Mg, Ca, Fe, Mn, Zn and Cu were present at low-intermediate concentrations. For the other 11 trace elements determined in this study (As, Be, Cd, Co, Cr, Ni, Pb, Se, Tl, U and V), the mean concentrations were very low or below of the LODs. The sites were classified through CA by using elements’ and physicochemical parameters data, then DA on the PCA factors was applied. Dendrograms identified three main groups. PCA explained 52.03% of the total variability

  4. Characterization of pectinase activity for enology from yeasts occurring in Argentine Bonarda grape

    PubMed Central

    Merín, María Gabriela; Martín, María Carolina; Rantsiou, Kalliopi; Cocolin, Luca; de Ambrosini, Vilma Inés Morata

    2015-01-01

    Pectinolytic enzymes are greatly important in winemaking due to their ability to degrade pectic polymers from grape, contributing to enhance process efficiency and wine quality. This study aimed to analyze the occurrence of pectinolytic yeasts during spontaneous fermentation of Argentine Bonarda grape, to select yeasts that produce extracellular pectinases and to characterize their pectinolytic activity under wine-like conditions. Isolated yeasts were grouped using PCR-DGGE and identified by partial sequencing of 26S rRNA gene. Isolates comprised 7 genera, with Aureobasidium pullulans as the most predominant pectinolytic species, followed by Rhodotorula dairenensis and Cryptococcus saitoi. No pectinolytic activity was detected among ascomycetous yeasts isolated on grapes and during fermentation, suggesting a low occurrence of pectinolytic yeast species in wine fermentation ecosystem. This is the first study reporting R. dairenensis and Cr. saitoi species with pectinolytic activity. R. dairenensis GM-15 produced pectinases that proved to be highly active at grape pH, at 12 °C, and under ethanol and SO2 concentrations usually found in vinifications (pectinase activity around 1.1 U/mL). This strain also produced cellulase activity at 12 °C and pH 3.5, but did not produce β-glucosidase activity under these conditions. The strain showed encouraging enological properties for its potential use in low-temperature winemaking. PMID:26413065

  5. Transfer of the Argentine Precordillera terrane from Laurentia: Constraints from detrital-zircon geochronology

    NASA Astrophysics Data System (ADS)

    Thomas, William A.; Astini, Ricardo A.; Mueller, Paul A.; Gehrels, George E.; Wooden, Joseph L.

    2004-11-01

    Ages from U-Pb and 207Pb/206Pb analyses of detrital zircons from synrift sandstone in the Lower Cambrian Cerro Totora Formation of the Argentine Precordillera have strong similarities to those from late synrift sandstones in the Lower Cambrian Rome Formation of southern Laurentia (Alabama). Ages of detrital zircons from the Cerro Totora sample cluster at 1160 970 Ma (60% of analyzed zircons), 1490 1300 Ma (24%), and 1890 1640 Ma (16%). Ages from two Rome samples cluster at 1240 970 Ma (32% of analyzed zircons), 1540 1270 Ma (31%), 1840 1610 Ma (14%), 1970 1890 Ma (5%), and 2930 2310 Ma (18%). The ages of detrital zircons from the Rome and Cerro Totora sandstones are consistent with sediment supply from the Grenville and older Proterozoic Laurentian provinces, and the older cluster in the Rome sandstones corresponds in age to the Laurentian Archean Superior province. Neither the Rome nor Cerro Totora samples include components younger than Grenville, and the lack of zircons from distinctly Gondwanan provinces is consistent with a Laurentian provenance. The detrital-zircon ages support previous interpretations that the Precordillera was rifted from the Ouachita embayment of Laurentia during Early Cambrian time and subsequently was transferred to Gondwana.

  6. [Prevalence of hepatitis C antibodies in plasma donors for the treatment of Argentine hemorrhagic fever].

    PubMed

    Saavedra, M C; Briggiler, A M; Enría, D; Riera, L; Ambrosio, A M

    1997-01-01

    For Argentine Hemorrhagic Fever, a disease caused by Junin virus (JV), there is an effective treatment, consisting of the transfusion of immune plasma (IP). This plasma is obtained from individuals who have had the disease. Since Hepatitis C virus (HCV) is transmitted parenterally, this study was aimed to estimate the prevalence of anti-HCV in a population of IP donors. In this study, 376 donors (47 females and 329 males) were studied: 95 individuals (24 females and 71 males) who had had FHA but had not received treatment and 88 laboratory workers (57 females and 31 males) who were included as controls. Serum samples were tested by EIA (Abbott, Germany) for HCV, and later confirmed by LIATEK (Organon, Ireland). Antibodies to HCV were detected in 29/376 donors (7.7%), in only 1/95 (1.0%) untreated convalescents of AHF and in 1/ 88 (1.1%) of laboratory workers. Retrospective analysis of the seroconversion for HCV in these individuals demonstrated that in 16/24 donors (66.6%) the infection by HCV was probably associated with the IP transfusion. The data presented herein show how the infection with HCV was disseminated among donors of IP, stressing the risk associated to transfusional practices, and emphasizing the need of vaccination to prevent AHF and also the risk inherent to its treatment.

  7. Efficacy and tolerability of an argentine intravenous immunoglobulin in pediatric patients with primary immunodeficiency diseases.

    PubMed

    Krasovec, S; Ornani, A; Oleastro, M; Rosenzweig, S; Roy, A; Perez, L; Campos, G; Marín, N; Martinez, A; Mahieu, C; Manfredi, M J; Sisti, A; Zelazko, M

    2007-03-01

    Inmunoglobulina G Endovenosa UNC is a 5% liquid Argentine intravenous immunoglobulin obtained from South American donors. This prospective trial was designed to evaluate if the product meets the minimal efficacy requirement of the US Food and Drug Administration of <1 serious infection/subject/year as well as its safety in pediatric patients with Primary Immunodeficiency Diseases. Thirty patients under the age of 18, with well-defined Primary Immunodeficiency Diseases received Inmunoglobulina G Endovenosa UNC (330-700 mg/kg every 3-4 weeks) for 6 months. Vital signs, laboratory abnormalities, adverse events and viral tests were assessed to evaluate safety. Two serious infections occurred (pneumonia and bacteriemia). The estimated infection rate was 0.114 serious infection/subject/year (95% CI, 0.003-0.2277). Minor adverse events occurred in 5.5% of infusions; fever and headache were the most common. Neither severe adverse events, nor abnormal laboratory values were observed. All viral assessments were negative. Inmunoglobulina G Endovenosa UNC meets the minimal efficacy requirement of the US Food and Drug Administration for pediatric Primary Immunodeficiency Diseases patients and showed efficacy and safety data comparable with other data published.

  8. Are ant-aphid associations a tritrophic interaction? Oleander aphids and Argentine ants.

    PubMed

    Bristow, C M

    1991-09-01

    Oleander aphids, (Aphis nerii), which are sporadically tended by ants, were used as a moded system to examine whether host plant factors associated with feeding site influenced the formation of ant-aphid associations. Seasonal patterns of host plant utilization and association with attendant ants were examined through bi-weekly censuses of the aphid population feeding on thirty ornamental oleander plands (Nerium oleander) in northern California in 1985 and 1986. Colonies occurred on both developing and senescing plant terminals, including leaf tips, floral structures, and pods. Aphids preferentially colonized leaf terminals early in the season, but showed no preference for feeding site during later periods. Argentine ants (Iridomyrmex humilis) occasionally tended aphid colonies. Colonies on floral tips were three to four times more likely to attract ants than colonies on leaf tips, even though the latter frequently contained more aphids. Ants showed a positive recruitment response to colonies on floral tips, with a significant correlation between colony size and number of ants. There was no recruitment response to colonies on leaf tips. These patterns were reproducible over two years despite large fluctuations in both aphid population density and ant activity. In a laboratory bioassay of aphid palatability, the generalist predator,Hippodamia convergens, took significantly more aphids reared on floral tips compared to those reared on leaf tips. The patterns reported here support the hypothesis that tritrophic factors may be important in modifying higher level arthropod mutualisms.

  9. Characterization of pectinase activity for enology from yeasts occurring in Argentine Bonarda grape.

    PubMed

    Merín, María Gabriela; Martín, María Carolina; Rantsiou, Kalliopi; Cocolin, Luca; de Ambrosini, Vilma Inés Morata

    2015-01-01

    Pectinolytic enzymes are greatly important in winemaking due to their ability to degrade pectic polymers from grape, contributing to enhance process efficiency and wine quality. This study aimed to analyze the occurrence of pectinolytic yeasts during spontaneous fermentation of Argentine Bonarda grape, to select yeasts that produce extracellular pectinases and to characterize their pectinolytic activity under wine-like conditions. Isolated yeasts were grouped using PCR-DGGE and identified by partial sequencing of 26S rRNA gene. Isolates comprised 7 genera, with Aureobasidium pullulans as the most predominant pectinolytic species, followed by Rhodotorula dairenensis and Cryptococcus saitoi. No pectinolytic activity was detected among ascomycetous yeasts isolated on grapes and during fermentation, suggesting a low occurrence of pectinolytic yeast species in wine fermentation ecosystem. This is the first study reporting R. dairenensis and Cr. saitoi species with pectinolytic activity. R. dairenensis GM-15 produced pectinases that proved to be highly active at grape pH, at 12 °C, and under ethanol and SO2 concentrations usually found in vinifications (pectinase activity around 1.1 U/mL). This strain also produced cellulase activity at 12 °C and pH 3.5, but did not produce β-glucosidase activity under these conditions. The strain showed encouraging enological properties for its potential use in low-temperature winemaking.

  10. Potential biocontrol actinobacteria: Rhizospheric isolates from the Argentine Pampas lowlands legumes.

    PubMed

    Solans, Mariana; Scervino, Jose Martin; Messuti, María Inés; Vobis, Gernot; Wall, Luis Gabriel

    2016-11-01

    Control of fungal plant diseases by using naturally occurring non-pathogenic microorganisms represents a promising approach to biocontrol agents. This study reports the isolation, characterization, and fungal antagonistic activity of actinobacteria from forage soils in the Flooding Pampa, Argentina. A total of 32 saprophytic strains of actinobacteria were obtained by different isolation methods from rhizospheric soil of Lotus tenuis growing in the Salado River Basin. Based on physiological traits, eight isolates were selected for their biocontrol-related activities such as production of lytic extracellular enzymes, siderophores, hydrogen cyanide (HCN), and antagonistic activity against Cercospora sojina, Macrophomia phaseolina, Phomopsis sp., Fusarium oxysporum, and Fusarium verticilloides. These actinobacteria strains were characterized morphologically, physiologically, and identified by using molecular techniques. The characterization of biocontrol-related activities in vitro showed positive results for exoprotease, phospholipase, fungal growth inhibition, and siderophore production. However, none of the strains was positive for the production of hydrogen cyanide (HCN). Streptomyces sp. MM140 presented the highest index for biocontrol, and appear to be promising pathogenic fungi biocontrol agents. These results show the potential capacity of actinobacteria isolated from forage soils in the Argentine Pampas lowlands as promising biocontrol agents, and their future agronomic applications.

  11. [Cross-cultural adaptation and Argentine validation of the Lower Extremity Functional Scale Questionnaire].

    PubMed

    Dell'Era, Silvina; Dimaro, Mariana; Gamboa, Anabella; Spath, María Belén; Salzberg, Sandra; Hernández, Daniel

    2016-01-01

    The Lower Extremity Functional Scale (LEFS) is a self-report questionnaire created to evaluate a patient's functional status in a wide spectrum of lower extremity musculoskeletal conditions. Thus far, there is no valid version in Argentina. The aims of this study were to translate the LEFS, cross-culturally adapt it for use in the Argentine population, and validate it in our country by determining its psychometric properties in patients over the age of 18 with lower extremity musculoskeletal conditions, comparing it with the SF-36 and the following functional tests: step test and timed up and go. One hundred and thirty three patients were included between July 2010 and January 2012. The test-retest reliability was high, with an ICC of 0.91 (95% CI 0.85 - 0.94). The correlation of the LEFS with the physical functioning subscale and the physical component summary score of the SF-36 was high (p < 0.001) and showed moderate response with the timed up and go and step test at the baseline (p < 0.001). This version of the LEFS is a valid, reliable tool used in Argentina to measure functional status in patients with lower extremity musculoskeletal conditions that we recommend for future clinical research projects and daily clinical use.

  12. Activity of bifenthrin, chlorfenapyr, fipronil, and thiamethoxam against Argentine ants (Hymenoptera: Formicidae).

    PubMed

    Wiltz, B A; Suiter, D R; Gardner, W A

    2009-12-01

    Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae). Mobility impairment and lethal times were determined after topical treatments. Ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and thiamethoxam. After 2 h, the number of fipronil-treated ants unable to walk out of test arenas did not differ from control ants. Median lethal time (LT50) after topical treatment was lowest in the bifenthrin treatment, followed by thiamethoxam, chlorfenapyr, and then fipronil. Mortality due to horizontal exposure was evaluated at 10, 20, or 30 degrees C, with topically treated ant corpses serving as donors. There was low to moderate horizontal activity in bifenthrin and chlorfenapyr treatments, with no temperature effect in bifenthrin treatments and a positive temperature effect in chlorfenapyr treatments. Mortality in the fipronil treatments was highest and was positively correlated with temperature. Thiamethoxam treatments did not differ from controls at 10 degrees C, but mortality increased with temperature. To evaluate contact activity, either all of 20% of the ants in a cohort were exposed to insecticide-treated pine needles. In both tests, mortality was highest in fipronil and bifenthrin treatments, followed by thiamethoxam, with lowest mortality in chlorfenapyr treatments. Effectiveness as a barrier was evaluated by providing a choice between bridges treated with insecticide or water. Although bifenthrin did not provide an impenetrable barrier, it was the only treatment having fewer ants than its paired control. Mortality data suggest that lack of recruitment rather than repellency account for this result.

  13. Evaluation of an enzyme immunosorbent assay for the diagnosis of Argentine haemorrhagic fever.

    PubMed

    Riera, L M; Feuillade, M R; Saavedra, M C; Ambrosio, A M

    1997-12-01

    To elaborate a set of serological tests for the diagnosis of Argentine haemorrhagic fever (AHF), an enzyme-linked immunosorbent assay (ELISA) for detection of specific anti-Junin virus (JV) IgG is described, and its performance is compared with that of the plaque reduction neutralization test (PRNT). The reproducibility, sensitivity, specificity, and confidence limits for positive and negative results for ELISA were statistically analysed. The value of 800 was demonstrated as the lowest positive titer. Titers > or = 800 varied within one (two-fold) dilution in 95.6% of the tests, while the sensitivity and specificity were 99.2% and 98.8%, respectively. The assay yielded 1% of false positives and 0.05% of false negatives. A comparison of ELISA to PRNT in detecting the seroconversion for JV was studied by the chi square test (comparison of proportions in paired samples) and the K parameter for agreement proportion. Comparison of ELISA to PRNT showed no significant difference in the proportions of positive and negative results of these assays (P < 0.01), demonstrating an equivalent performance (K = 0.98) in the diagnosis of AHF. In addition, the simplicity and safety of the procedures involved make this ELISA the most suitable test to detect natural human JV infections.

  14. Chromosomal variation in Argentine populations of Akodon montensis Thomas, 1913 (Rodentia, Cricetidae, Sigmodontinae)

    PubMed Central

    Malleret, Matías Maximiliano; Labaroni, Carolina Alicia; García, Gabriela Verónica; Ferro, Juan Martín; Martí, Dardo Andrea; Lanzone, Cecilia

    2016-01-01

    Abstract The genus Akodon Meyen, 1833 is one of the most species-rich among sigmodontine rodents and has great chromosome variability. Akodon montensis has a relatively broad distribution in South America, and Argentine populations are located in the southernmost region of its range. Brazilian populations have important chromosomal variability, but cytogenetic data from Argentina are scarce. We performed a chromosome characterization of natural populations of Akodon montensis using conventional staining, C-banding, Ag-NORs and base-specific fluorochromes. A total of 31 specimens from five localities of Misiones Province, in Argentina, were analyzed. The 2n=24 chromosomes was the most frequently observed karyotype. However, five individuals presented 25 chromosomes due to a supernumerary B-chromosome; and one individual had 2n=26 due to one B plus a trisomy for chromosome 11. Additionally, two XY females and two variants of the X chromosomes were found. C-positive centromeric bands occurred in all chromosomes; additional C-bands were observed in some autosomes, the X, Y and B chromosomes. Ag-NORs were observed in five autosomes, and the B chromosome was frequently marked. Fluorochrome banding was similar among karyotypes of the analyzed populations. Comparisons of cytogenetic data among populations of Argentina and Brazil showed the presence of high intraspecific variability in Akodon montensis and some differences among regions. PMID:27186343

  15. Bait preference by the Argentine ant (Hymenoptera: Formicidae) in Haleakala National Park, Hawaii

    USGS Publications Warehouse

    Krushelnycky, Paul D.; Reimer, Neil J.

    1998-01-01

    The Argentine ant, Linepithema humile (Mayr), has proven to be a threat to native arthropod species in Haleakala National Park, Maui, HI, and is also a potential threat to the park's native flora. As it continues to expand its range, an effort has been undertaken to eradicate it, or at the least, control its spread. The 1st part of this effort focused on finding a bait carrier for subsequent toxicant-based control tests. A year-long bait preference test was implemented at each of the ant's 2 infestation sites in Haleakala National Park, in which 6 solid baits and 2 liquid baits were assessed for attractiveness and feasibility for large scale control. At both sites, a toxicant-free formulation of Maxforce, a protein-based granular bait made from ground silkworm, Bombyx mori (L.), pupae, and a 25% sugar water solution were the most attractive baits. Ants took more Maxforce (without toxicant) and sugar water than all other baits, including honey granules and a fish protein bait. Sugar water, however, is difficult to distribute over large natural areas. Maxforce was therefore concluded to be the best bait carrier for toxicant-based control at Haleakala National Park because of its attractiveness and its ease for large scale broadcast dispersal.

  16. Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna.

    PubMed

    Alberto, M R; Zampini, I C; Isla, M I

    2009-09-01

    We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida) that grow in the Argentine Puna (3800 m above sea level) and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts showed high phenolic compound concentration (0.5-1.6 mg/mL), mainly flavones and flavonols (0.1-0.8 mg/mL). The extracts showed hydrogen donating ability (DPPH and ABTS) and reactive oxygen species scavenging activity (O2-, OH-, H2O2). The ability of the extracts to inhibit cyclooxygenase enzymes (COX-1 and COX-2) was determined by calculating percent inhibition of PGE2 production measured by enzyme immunoassay. All extracts inhibited both enzymes with IC50 values of 2.0 to 16.7 microg/mL. The anti-inflammatory activity of B. incarum and C. atacamensis extracts was higher than that of B. boliviensis and P. lucida. The IC50 values obtained for indomethacin were 0.11 and 0.78 microM for COX-1 and COX-2, respectively. The present results are consistent with the anecdotal use of these species in phytotherapic preparations.

  17. [Candid#1 vaccine against Argentine hemorrhagic fever produced in Argentina. Immunogenicity and safety].

    PubMed

    Enria, Delia A; Ambrosio, Ana M; Briggiler, Ana M; Feuillade, María Rosa; Crivelli, Eleonora

    2010-01-01

    A clinical study in 946 human volunteers was done to compare Candid #1 vaccine manufactured in Argentina with the vaccine produced in USA that had been previously used. The efficacy was evaluated using immunogenicity measured by the detection of neutralizing antibodies as a subrogate marker. Safety was evaluated comparing the rate of adverse events. Both vaccines showed a comparable rate of seroconversion, slightly higher than the efficacy estimated from previous studies (95.5%). There were no severe adverse events related to the vaccines. The general events considered related to the vaccines were not clinically relevant and disappeared either spontaneously or with symptomatic treatment. Similar rates of adverse events (29.9% for the Argentine vaccine and 35.0% for the USA vaccine) were found for both vaccines. These included: headache, weakness, myalgias, mild low blood cell (< 4,000/mm(3)) and platelet (< 150,000/mm(3)) counts, nausea and/or vomiting, fever, retroocular pain, dizziness, microhematuria, low backache and exantema. These results indicate that the vaccine Candid#1 manufactured in Argentina is equivalent to the manufactured in USA. These results allowed the National Institute of Human Viral Diseases (INEVH) to register the vaccine produced locally under the National Regulatory Authority (ANMAT).

  18. Individual variation in exploratory behaviour improves speed and accuracy of collective nest selection by Argentine ants

    PubMed Central

    Hui, Ashley; Pinter-Wollman, Noa

    2014-01-01

    Collective behaviours are influenced by the behavioural composition of the group. For example, a collective behaviour may emerge from the average behaviour of the group's constituents, or be driven by a few key individuals that catalyse the behaviour of others in the group. When ant colonies collectively relocate to a new nest site, there is an inherent trade-off between the speed and accuracy of their decision of where to move due to the time it takes to gather information. Thus, variation among workers in exploratory behaviour, which allows gathering information about potential new nest sites, may impact the ability of a colony to move quickly into a suitable new nest. The invasive Argentine ant, Linepithema humile, expands its range locally through the dispersal and establishment of propagules: groups of ants and queens. We examine whether the success of these groups in rapidly finding a suitable nest site is affected by their behavioural composition. We compared nest choice speed and accuracy among groups of all-exploratory, all-nonexploratory and half-exploratory–half-nonexploratory individuals. We show that exploratory individuals improve both the speed and accuracy of collective nest choice, and that exploratory individuals have additive, not synergistic, effects on nest site selection. By integrating an examination of behaviour into the study of invasive species we shed light on the mechanisms that impact the progression of invasion. PMID:25018558

  19. Chromosomal variation in Argentine populations of Akodon montensis Thomas, 1913 (Rodentia, Cricetidae, Sigmodontinae).

    PubMed

    Malleret, Matías Maximiliano; Labaroni, Carolina Alicia; García, Gabriela Verónica; Ferro, Juan Martín; Martí, Dardo Andrea; Lanzone, Cecilia

    2016-01-01

    The genus Akodon Meyen, 1833 is one of the most species-rich among sigmodontine rodents and has great chromosome variability. Akodon montensis has a relatively broad distribution in South America, and Argentine populations are located in the southernmost region of its range. Brazilian populations have important chromosomal variability, but cytogenetic data from Argentina are scarce. We performed a chromosome characterization of natural populations of Akodon montensis using conventional staining, C-banding, Ag-NORs and base-specific fluorochromes. A total of 31 specimens from five localities of Misiones Province, in Argentina, were analyzed. The 2n=24 chromosomes was the most frequently observed karyotype. However, five individuals presented 25 chromosomes due to a supernumerary B-chromosome; and one individual had 2n=26 due to one B plus a trisomy for chromosome 11. Additionally, two XY females and two variants of the X chromosomes were found. C-positive centromeric bands occurred in all chromosomes; additional C-bands were observed in some autosomes, the X, Y and B chromosomes. Ag-NORs were observed in five autosomes, and the B chromosome was frequently marked. Fluorochrome banding was similar among karyotypes of the analyzed populations. Comparisons of cytogenetic data among populations of Argentina and Brazil showed the presence of high intraspecific variability in Akodon montensis and some differences among regions.

  20. Quantifying uncertainty in the potential distribution of an invasive species: climate and the Argentine ant.

    PubMed

    Hartley, Stephen; Harris, Richard; Lester, Philip J

    2006-09-01

    Maps of a species' potential range make an important contribution to conservation and invasive species risk analysis. Spatial predictions, however, should be accompanied by an assessment of their uncertainty. Here, we use multimodel inference to generate confidence intervals that incorporate both the uncertainty involved in model selection as well as the error associated with model fitting. In the case of the invasive Argentine ant, we found that it was most likely to occur where the mean daily temperature in mid-winter was 7-14 degrees C and maximum daily temperatures during the hottest month averaged 19-30 degrees C. Uninvaded regions vulnerable to future establishment include: southern China, Taiwan, Zimbabwe, central Madagascar, Morocco, high-elevation Ethiopia, Yemen and a number of oceanic islands. Greatest uncertainty exists over predictions for China, north-east India, Angola, Bolivia, Lord Howe Island and New Caledonia. Quantifying the costs of different errors (false negatives vs. false positives) was considered central for connecting modelling to decision-making and management processes.

  1. Transfer of the Argentine Precordillera terrane from Laurentia: Constraints from detrital-zircon geochronology

    USGS Publications Warehouse

    Thomas, W.A.; Astini, R.A.; Mueller, P.A.; Gehrels, G.E.; Wooden, J.L.

    2004-01-01

    Ages from U-Pb and 207Pb/206Pb analyses of detrital zircons from synrift sandstone in the Lower Cambrian Cerro Totora Formation of the Argentine Precordillera have strong similarities to those from late synrift sandstones in the Lower Cambrian Rome Formation of southern Laurentia (Alabama). Ages of detrital zircons from the Cerro Totora sample cluster at 1160-970 Ma (60% of analyzed zircons , 1490-1300 Ma (24%), and 1890-1640 Ma (16%). Ages from two Rome samples cluster at 1240-970 Ma (32% of analyzed zircons), 1540-1270 Ma (31%), 1840-1610 Ma (14%), 1970-1890 Ma (5%), and 2930-2310 Ma (18%). The ages of detrital zircons from the Rome and Cerro Totora sandstones are consistent with sediment supply from the Grenville and older Proterozoic Laurentian provinces, and the older cluster in the Rome sandstones corresponds in age to the Laurentian Archean Superior province. Neither the Rome nor Cerro Totora samples include components younger than Grenville, and the lack of zircons from distinctly Gondwanan provinces is consistent with a Laurentian provenance. The detrital-zircon ages support previous interpretations that the Precordillera was rifted from the Ouachita embayment of Laurentia during Early Cambrian time and subsequently was transferred to Gondwana. ?? 2004 Geological Society of America.

  2. Aeromonas hydrophila and its relation with drinking water indicators of microbiological quality in Argentine.

    PubMed

    Fernández, M C; Giampaolo, B N; Ibañez, S B; Guagliardo, M V; Esnaola, M M; Conca, L; Valdivia, P; Stagnaro, S M; Chiale, C; Frade, H

    2000-01-01

    In Argentine, water municipal supplies disinfection is carried out by chlorine. We have isolated Aeromonas hydrophila from a chlorinated water supply in Buenos Aires that fulfilled Argentinean microbiological quality standards. It is an aquatic organism that could produce cytotoxins and enterotoxins associated with acute gastroenteritis and wound infections in human and hemorrhagic septicaemia of fish, reptiles and amphibians. The isolated strain produced protein bands at isoelectric point in the range of 4.6-5.3 lightly labile at 56 degrees C and heat labile at 100 degrees C non cholera antitoxin reactive in electrofocusing assay (IEF) and showed hemolytic activity thermolabile at 56 degrees C and 100 degrees C in 5% rabbit erythrocytes in phosphate buffered saline. A cytotoxic effect thermolabile at 56 degrees C and 100 degrees C and a cytotonic activity were demonstrated in Vero cell cultures. Survival assay of A. hydrophila and indicator organisms would show no correlation between their contamination sources. Biofilms production could explain the persistence of this gram negative pathogen organism in chlorinated tap water. A water system supply maintenance program and pasteurisation may be performed in spite of water chlorination.

  3. Effect of Temperature on the Development and Survival of the Argentine Ant, Linepithema humile

    PubMed Central

    Abril, Silvia; Oliveras, Jordi; Gómez, Crisanto

    2010-01-01

    The influence of temperature on the developmental times and survival of insects can largely determine their distribution. For invasive species, like the Argentine ant, Linepithema humile Mayr (Hymenoptera: Formicidae), these data are essential for predicting their potential range based on mechanistic models. In the case of this species, such data are too scarce and incomplete to make accurate predictions based on its physiological needs. This research provides comprehensive new data about brood survival and developmental times at a wide range of temperatures under laboratory conditions. Temperature affected both the complete brood development from egg to adult worker and each of the immature stages separately. The higher the temperature, the shorter the development times. Brood survival from egg to adult was low, with the maximum survival rate being only 16% at 26° C. Temperature also affected survival of each of the immature stages differently: eggs were negatively affected by high temperatures, while larvae were negatively affected by low temperatures, and the survival of pupae was apparently independent of environmental temperature. At 32° C no eggs survived, while at 18° C less than 2% of the eggs hatched into larva. The data from the present study are essential for developing prediction models about the distribution range of this tramp species based on its physiological needs in relation to temperature. PMID:20673121

  4. Genetic structure, behaviour and invasion history of the Argentine ant supercolony in Australia.

    PubMed

    Suhr, Elissa L; O'Dowd, Dennis J; McKechnie, Stephen W; Mackay, Duncan A

    2011-05-01

    Biological invasions have significant ecological, evolutionary and economic consequences. Ants are exemplary invaders and their invasion success is frequently attributed to a shift in social structure between native and introduced populations. Here, we use a multidisciplinary approach to determine the social structure, origin and expansion of the invasive Argentine ant, Linepithema humile, in Australia by linking behavioural and genetic studies with indicators of dispersal pathways and propagule pressure. Behavioural assays revealed a complete absence of aggression within and between three cities - Melbourne, Adelaide and Perth - spanning 2700 km across Australia. Microsatellite analyses showed intracity genetic homogeneity and limited but significant intercity genetic differentiation. Exceptions were two Perth nests that likely represent independent translocations from Adelaide. These patterns suggest efficient local gene flow with more limited jump dispersal via transport corridors between cities. Microsatellite analyses of L. humile from potential source regions, combined with data from port interceptions, trade pathways and the timeline of spread within Australia, implicate the main European supercolony as the source of L. humile in Melbourne. Such an introduction probably then redistributed across Australia and spread to New Zealand to form an expansive Australasian supercolony.

  5. Mating frequency and genetic structure of the Argentine ant Linepithema humile.

    PubMed

    Krieger, M J; Keller, L

    2000-02-01

    The nest and population genetic structures of the Argentine ant, Linepithema humile were investigated using eight microsatellite loci. Genotypes of the sperm from spermathecae of 87 queens were consistent with all queens being singly inseminated. The probability of a double mating remaining undetected was low (0.012) suggesting that no queens or only a very low proportion mate multiply. The relatedness between the queens and their mates was negative (R = -0.164 +/- 0.044) and significantly different to zero (P = 0.020). However, the high negative relatedness value was caused by a significant allele frequency difference between the sexes at a single locus (Lhum-28). When this locus was removed from the analyses, the relatedness was not significantly different from zero (R = 0.013 +/- 0.050, P = 0.812). Analysis of 10 nests revealed that the genetic differentiation among nests was weak (FST = 0.003) and not distinguishable from zero (P = 0.468). Similarly, the overall relatedness among nestmate females was not significantly different from zero (R = 0.007 +/- 0.018, P = 0.706). These results are consistent with the lack of distinct nest boundaries and the large number of queens per nest in the population studied. Although mating takes place inside the nest, the inbreeding coefficient was close to zero (F = 0.007 +/- 0.025, P = 0.786). Overall, these data indicate substantial local gene flow mediated by movement of reproductives among colonies.

  6. Genetic compatibility affects division of labor in the Argentine ant Linepithema humile.

    PubMed

    Libbrecht, Romain; Keller, Laurent

    2013-02-01

    Division of labor is central to the organization of insect societies. Within-colony comparisons between subfamilies of workers (patrilines or matrilines) revealed genetic effects on division of labor in many social insect species. Although this has been taken as evidence for additive genetic effects on division of labor, it has never been experimentally tested. To determine the relative roles of additive and nonadditive genetic effects (e.g., genetic compatibility, epistasis, and parent-of-origin imprinting effects) on worker behavior, we performed controlled crosses using the Argentine ant Linepithema humile. Three of the measured behaviors (the efficiency to collect pupae, the foraging propensity, and the distance between non-brood-tenders and brood) were affected by the maternal genetic background and the two others (the efficiency to feed larvae and the distance between brood-tenders and brood) by the paternal genetic background. Moreover, there were significant interactions between the maternal and paternal genetic backgrounds for three of the five behaviors. These results are most consistent with parent-of-origin and genetic compatibility effects on division of labor. The finding of nonadditive genetic effects is in strong contrast with the current view and has important consequences for our understanding of division of labor in insect societies. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  7. Effect of temperature on the development and survival of the Argentine ant, Linepithema humile.

    PubMed

    Abril, Silvia; Oliveras, Jordi; Gómez, Crisanto

    2010-01-01

    The influence of temperature on the developmental times and survival of insects can largely determine their distribution. For invasive species, like the Argentine ant, Linepithema humile Mayr (Hymenoptera: Formicidae), these data are essential for predicting their potential range based on mechanistic models. In the case of this species, such data are too scarce and incomplete to make accurate predictions based on its physiological needs. This research provides comprehensive new data about brood survival and developmental times at a wide range of temperatures under laboratory conditions. Temperature affected both the complete brood development from egg to adult worker and each of the immature stages separately. The higher the temperature, the shorter the development times. Brood survival from egg to adult was low, with the maximum survival rate being only 16% at 26 degrees C. Temperature also affected survival of each of the immature stages differently: eggs were negatively affected by high temperatures, while larvae were negatively affected by low temperatures, and the survival of pupae was apparently independent of environmental temperature. At 32 degrees C no eggs survived, while at 18 degrees C less than 2% of the eggs hatched into larva. The data from the present study are essential for developing prediction models about the distribution range of this tramp species based on its physiological needs in relation to temperature.

  8. Genetic structure, behaviour and invasion history of the Argentine ant supercolony in Australia

    PubMed Central

    Suhr, Elissa L; O'Dowd, Dennis J; McKechnie, Stephen W; Mackay, Duncan A

    2011-01-01

    Biological invasions have significant ecological, evolutionary and economic consequences. Ants are exemplary invaders and their invasion success is frequently attributed to a shift in social structure between native and introduced populations. Here, we use a multidisciplinary approach to determine the social structure, origin and expansion of the invasive Argentine ant, Linepithema humile, in Australia by linking behavioural and genetic studies with indicators of dispersal pathways and propagule pressure. Behavioural assays revealed a complete absence of aggression within and between three cities – Melbourne, Adelaide and Perth – spanning 2700 km across Australia. Microsatellite analyses showed intracity genetic homogeneity and limited but significant intercity genetic differentiation. Exceptions were two Perth nests that likely represent independent translocations from Adelaide. These patterns suggest efficient local gene flow with more limited jump dispersal via transport corridors between cities. Microsatellite analyses of L. humile from potential source regions, combined with data from port interceptions, trade pathways and the timeline of spread within Australia, implicate the main European supercolony as the source of L. humile in Melbourne. Such an introduction probably then redistributed across Australia and spread to New Zealand to form an expansive Australasian supercolony. PMID:25567996

  9. Loss of Wolbachia infection during colonisation in the invasive Argentine ant Linepithema humile.

    PubMed

    Reuter, M; Pedersen, J S; Keller, L

    2005-03-01

    WOLBACHIA are maternally inherited bacteria, which are very common in arthropods and nematodes. Wolbachia infection may affect host reproduction through feminisation, parthenogenesis, male-killing, cytoplasmic incompatibility and increased fecundity. Previous studies showing discrepancies between the phylogenies of Wolbachia and its arthropod hosts indicate that infection is frequently lost, but the causes of symbiont extinction have so far remained elusive. Here, we report data showing that colonisation of new habitats is a possible mechanism leading to the loss of infection. The presence and prevalence of Wolbachia were studied in three native and eight introduced populations of the Argentine ant Linepithema humile. The screening shows that the symbiont is common in the three native L. humile populations analysed. In contrast, Wolbachia was detected in only one of the introduced populations. The loss of infection associated with colonisation of new habitats may result from drift (founder effect) or altered selection pressures in the new habitat. Furthermore, a molecular phylogeny based on sequences of the Wolbachia wsp gene indicates that L. humile has been infected by a single strain. Horizontal transmission of the symbiont may be important in ants as suggested by the sequence similarity of strains in the three genera Linepithema, Acromyrmex, and Solenopsis native from South and Central America.

  10. Individual variation in exploratory behaviour improves speed and accuracy of collective nest selection by Argentine ants.

    PubMed

    Hui, Ashley; Pinter-Wollman, Noa

    2014-07-01

    Collective behaviours are influenced by the behavioural composition of the group. For example, a collective behaviour may emerge from the average behaviour of the group's constituents, or be driven by a few key individuals that catalyse the behaviour of others in the group. When ant colonies collectively relocate to a new nest site, there is an inherent trade-off between the speed and accuracy of their decision of where to move due to the time it takes to gather information. Thus, variation among workers in exploratory behaviour, which allows gathering information about potential new nest sites, may impact the ability of a colony to move quickly into a suitable new nest. The invasive Argentine ant, Linepithema humile, expands its range locally through the dispersal and establishment of propagules: groups of ants and queens. We examine whether the success of these groups in rapidly finding a suitable nest site is affected by their behavioural composition. We compared nest choice speed and accuracy among groups of all-exploratory, all-nonexploratory and half-exploratory-half-nonexploratory individuals. We show that exploratory individuals improve both the speed and accuracy of collective nest choice, and that exploratory individuals have additive, not synergistic, effects on nest site selection. By integrating an examination of behaviour into the study of invasive species we shed light on the mechanisms that impact the progression of invasion.

  11. Chemical defense by the native winter ant (Prenolepis imparis) against the invasive Argentine ant (Linepithema humile).

    PubMed

    Sorrells, Trevor R; Kuritzky, Leah Y; Kauhanen, Peter G; Fitzgerald, Katherine; Sturgis, Shelby J; Chen, Jimmy; Dijamco, Cheri A; Basurto, Kimberly N; Gordon, Deborah M

    2011-04-19

    The invasive Argentine ant (Linepithema humile) is established worldwide and displaces native ant species. In northern California, however, the native winter ant (Prenolepis imparis) persists in invaded areas. We found that in aggressive interactions between the two species, P. imparis employs a potent defensive secretion. Field observations were conducted at P. imparis nest sites both in the presence and absence of L. humile. These observations suggested and laboratory assays confirmed that P. imparis workers are more likely to secrete when outnumbered by L. humile. Workers of P. imparis were also more likely to secrete near their nest entrances than when foraging on trees. One-on-one laboratory trials showed that the P. imparis secretion is highly lethal to L. humile, causing 79% mortality. The nonpolar fraction of the secretion was chemically analyzed with gas chromatography/mass spectrometry, and found to be composed of long-chain and cyclic hydrocarbons. Chemical analysis of dissected P. imparis workers showed that the nonpolar fraction is derived from the Dufour's gland. Based on these conclusions, we hypothesize that this chemical defense may help P. imparis to resist displacement by L. humile.

  12. Patch sampling behaviour and future foraging expectations in Argentine ants, Linepithema humile

    PubMed

    Nonacs; Soriano

    1998-03-01

    Nests of Argentine ants, L. humile, were exposed to pairs of foraging patches of varying quality. These patches varied from never having food to having food for 4 h every day. After 15 days, colonies were allowed an added access to a new patch. The new patch, however, never contained food. The sampling behaviour of nests towards the initial patches and the new patch suggested that the nests were using a sampling rule based on maximizing net benefits of finding food minus the cost of sampling. The behaviour of the nests towards the new patch was also significantly affected by what the foraging workers had previouisly encountered in the foraging patches. The behaviour of the L. humile colonies is similar in pattern to what would result by Bayesian updating of expectations for success in novel foraging opportunities. These data are the first suggestions of such an ability in an insect. Copyright 1998 The Association for the Study of Animal Behaviour Copyright 1998 The Association for the Study of Animal Behaviour.

  13. Queen execution increases relatedness among workers of the invasive Argentine ant, Linepithema humile.

    PubMed

    Inoue, Maki N; Ito, Fuminori; Goka, Koichi

    2015-09-01

    Polygyny in social insects can greatly reduce within-nest genetic relatedness. In polygynous ant species, potential rival queens in colonies with multiple queens are often executed by other queens, workers, or both. The Argentine ant, Linepithema humile, native to South America, forms a "supercolony" that is composed of a large number of nests and is considered to contribute to the ant's invasion success. Currently, four mutually antagonistic supercolonies are contiguously distributed within a small area of Japan. Here, we analyzed the genetic structure and relatedness within and among the four supercolonies using microsatellite markers to clarify how L. humile maintains its supercoloniality. The results of AMOVA and BASP, the F ST values, and the existence of several private alleles indicated that the L. humile population in the Kobe area had a characteristic genetic structure. Within a given supercolony, there was significant genetic differentiation (F ST) among workers collected in May and those collected in September. The significant deviation from Hardy-Weinberg equilibrium increased, and the relatedness among workers significantly increased from May to September in all supercolonies. This result suggested that the supercolonies replaced old queens with new ones during the reproductive season, thus supporting the plausibility of queen execution. From the perspective of kin selection, workers collectively eliminate queens, thereby increasing their own inclusive fitness. Restricted gene flow among supercolonies, together with mating with sib and queen execution, could help to maintain the unique social structure of L. humile, the distribution of which is expanding worldwide.

  14. Chemical Defense by the Native Winter Ant (Prenolepis imparis) against the Invasive Argentine Ant (Linepithema humile)

    PubMed Central

    Kauhanen, Peter G.; Fitzgerald, Katherine; Sturgis, Shelby J.; Chen, Jimmy; Dijamco, Cheri A.; Basurto, Kimberly N.; Gordon, Deborah M.

    2011-01-01

    The invasive Argentine ant (Linepithema humile) is established worldwide and displaces native ant species. In northern California, however, the native winter ant (Prenolepis imparis) persists in invaded areas. We found that in aggressive interactions between the two species, P. imparis employs a potent defensive secretion. Field observations were conducted at P. imparis nest sites both in the presence and absence of L. humile. These observations suggested and laboratory assays confirmed that P. imparis workers are more likely to secrete when outnumbered by L. humile. Workers of P. imparis were also more likely to secrete near their nest entrances than when foraging on trees. One-on-one laboratory trials showed that the P. imparis secretion is highly lethal to L. humile, causing 79% mortality. The nonpolar fraction of the secretion was chemically analyzed with gas chromatography/mass spectrometry, and found to be composed of long-chain and cyclic hydrocarbons. Chemical analysis of dissected P. imparis workers showed that the nonpolar fraction is derived from the Dufour's gland. Based on these conclusions, we hypothesize that this chemical defense may help P. imparis to resist displacement by L. humile. PMID:21526231

  15. Cuticular hydrocarbons as queen adoption cues in the invasive Argentine ant.

    PubMed

    Vásquez, Gissella M; Schal, Coby; Silverman, Jules

    2008-04-01

    In social insects, individuals typically recognize and behave aggressively towards alien conspecifics, thereby maintaining colony integrity. This is presumably achieved via a nestmate recognition system in which cuticular compounds, usually cuticular hydrocarbons (CHC), of genetic and/or environmental origin serve as recognition cues. Most invasive populations of the Argentine ant, Linepithema humile (Mayr), display minimal nestmate-non-nestmate discrimination, resulting in low levels of intraspecific aggression allowing free movement of workers and queens among nests. However, invasive L. humile in the southeastern United States show relatively high levels of intraspecific aggression, and selectively adopt non-nestmate queens. Using behavioral assays and gas chromatography, we found an association between non-nestmate queen adoption and similarity of the CHC profiles of adopted and host colony queens. Also, nestmate and non-nestmate queen CHC profiles became more similar after adoption by queenless colonies. Furthermore, queens treated with non-nestmate queen CHC had distinct CHC profiles and were generally attacked by nestmate workers. We suggest that in L. humile, CHC are used as queen recognition cues, and that queen recognition errors are more likely to occur when the CHC profiles of non-nestmate and host colony queens are similar. Our findings provide further evidence for the complex and dynamic nature of L. humile nestmate discrimination, which may in part underlie the success of introduced populations of this invasive ant.

  16. Argentines' collective memories of the military Junta of 1976: differences and similarities across generations and ideology.

    PubMed

    Muller, Felipe; Bermejo, Federico; Hirst, William

    2016-08-01

    Although memories about a nation's past usually are semantic in nature, a distinction needs to be made between lived and distant semantic collective memories. The former refers to memories of community-relevant events occurring during the lifetime of the rememberer, whereas the latter to memories of distant events. Does the content of lived and distant semantic collective memories differ? Employing both free and cued recall, we examined the memories of younger and older Argentines of the Military Junta of 1976. We also examined the effects of political ideology. Content analysis indicated that (1) lived semantic collective memories were more likely to contain personal recollections than distant semantic collective memories, even though those with distant semantic collective memories could have incorporated memories of the parent's personal experience in their recollections, (2) lived semantic collective memories contained more causal statements, and (3) those on the Right with distant semantic collective memories were more likely to claim that they "Don't know" or offer positive accounts of the Junta, suggesting a need to "defend" the reputation of those on the Right. The results are discussed in terms of the goals and plans different generations might have when recollecting their nation's past.

  17. [Survival capacity of Corynebacterium pseudotuberculosis biovar ovis in different soil types from Chubut, Argentine Patagonia].

    PubMed

    Alvarez, Laura; William, Aillin; Castro, Isabel; Valenzuela, Fernanda; Estevao Belchior, Silvia

    Corynebacterium pseudotuberculosis is transmitted among sheep in Argentine Patagonia causing pseudotuberculosis. The bacterium penetrates the skin or mucous membrane wounds, infecting the superficial lymph nodes and viscera. When surface abscesses are cut during shearing, they drain their purulent contents and contaminate tools and the soil. The objective of this work was to evaluate the survival capacity of C. pseudotuberculosis over time, in soils from the extra-Andean Patagonia region. Five types of superficial soils were collected from different areas in Chubut province (extra-Andean Patagonia), having distinctive physicochemical properties including organic matter content (very high to nonexistent), pH (neutral to strongly alkaline), electrical conductivity (saline to non-saline) and texture (sandy, clayey, silty loam). Different aliquots of each type of soil were inoculated with C. pseudotuberculosis PAT10 strain isolated from a Patagonian sheep, and were stored at room temperature. The number of surviving bacteria was determined at various times. Sixty percent (60%) of the inoculated C. pseudotuberculosis population survived for 80 to 210 days in soils with moderate to high organic matter content respectively. Silty soils favored bacterial survival, whereas the variables pH and salinity had no effect on survival. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Using return on investment to maximize conservation effectiveness in Argentine grasslands.

    PubMed

    Murdoch, William; Ranganathan, Jai; Polasky, Stephen; Regetz, James

    2010-12-07

    The rapid global loss of natural habitats and biodiversity, and limited resources, place a premium on maximizing the expected benefits of conservation actions. The scarcity of information on the fine-grained distribution of species of conservation concern, on risks of loss, and on costs of conservation actions, especially in developing countries, makes efficient conservation difficult. The distribution of ecosystem types (unique ecological communities) is typically better known than species and arguably better represents the entirety of biodiversity than do well-known taxa, so we use conserving the diversity of ecosystem types as our conservation goal. We define conservation benefit to include risk of conversion, spatial effects that reward clumping of habitat, and diminishing returns to investment in any one ecosystem type. Using Argentine grasslands as an example, we compare three strategies: protecting the cheapest land ("minimize cost"), maximizing conservation benefit regardless of cost ("maximize benefit"), and maximizing conservation benefit per dollar ("return on investment"). We first show that the widely endorsed goal of saving some percentage (typically 10%) of a country or habitat type, although it may inspire conservation, is a poor operational goal. It either leads to the accumulation of areas with low conservation benefit or requires infeasibly large sums of money, and it distracts from the real problem: maximizing conservation benefit given limited resources. Second, given realistic budgets, return on investment is superior to the other conservation strategies. Surprisingly, however, over a wide range of budgets, minimizing cost provides more conservation benefit than does the maximize-benefit strategy.

  19. Emerging diseases and their impact on animal commerce: the Argentine lesson.

    PubMed

    Cané, B G; Leanes, L F; Mascitelli, L O

    2004-10-01

    As a result of the Argentine experience with foot-and-mouth disease (FMD) in 2001, a need was postulated for the establishment of efficient supranational schemes for continuous surveillance of the interrelations between tropical extractives livestock systems and the prairies that are optimal for the feeding of livestock in the southern region of South America. FMD in Argentina and in other countries, new or re-emerging risks from avian influenza with potential risks for public health, the spongiform encephalopathies, porcine reproductive and respiratory syndrome, and classical swine fever, among other animal diseases, have generated a strong reaction and evolution within the veterinary services of the country. These present lessons will influence decision-making within countries and should be accepted by the technical and scientific community. From the perspective of the official animal health sector and with the FMD eradication plan as a basis within the national territory, we have worked not only to achieve international recognition and credibility within animal health systems, but also to realize the formation of a regional block of countries that can be recognized internationally as an area with equivalent animal health status. We emphasize not only that this lesson is useful in FMD, but also that it is possible to apply the valuable conclusions reached for other emerging or re-emerging diseases.

  20. The role of abiotic conditions in shaping the long-term patterns of a high-elevation Argentine ant invasion

    USGS Publications Warehouse

    Krushelnycky, P.D.; Joe, S.M.; Medeiros, A.C.; Daehler, C.C.; Loope, L.L.

    2005-01-01

    Analysis of long-term patterns of invasion can reveal the importance of abiotic factors in influencing invasion dynamics, and can help predict future patterns of spread. In the case of the invasive Argentine ant (Linepithema humile), most prior studies have investigated this species' limitations in hot and dry climates. However, spatial and temporal patterns of spread involving two ant populations over the course of 30 years at a high elevation site in Hawaii suggest that cold and wet conditions have influenced both the ant's distribution and its rate of invasion. In Haleakala National Park on Maui, we found that a population invading at lower elevation is limited by increasing rainfall and presumably by associated decreasing temperatures. A second, higher elevation population has spread outward in all directions, but rates of spread in different directions appear to have been strongly influenced by differences in elevation and temperature. Patterns of foraging activity were strongly tied to soil temperatures, supporting the hypothesis that variation in temperature can influence rates of spread. Based on past patterns of spread, we predicted a total potential range that covers nearly 50% of the park and 75% of the park's subalpine habitats. We compared this rough estimate with point predictions derived from a degree-day model for Argentine ant colony reproduction, and found that the two independent predictions match closely when soil temperatures are used in the model. The cold, wet conditions that have influenced Argentine ant invasion at this site are likely to be influential at other locations in this species' current and future worldwide distribution. ?? 2005 Blackwell Publishing Ltd.

  1. A new genus and species of Platyischnopidae (Amphipoda: Gammaridea) from the Argentine sea, South-West Atlantic ocean.

    PubMed

    Chiesa, Ignacio L; Alonso, Gloria M

    2014-05-30

    The family Platyischnopidae is herein reported for the first time in the Argentine Sea, South-West Atlantic Ocean. A new genus and species, Platyisao holodividum gen. et. sp. nov., collected off the coast of Buenos Aires and Río Negro provinces, is fully described and illustrated. Platyisao gen. nov. is distinguished from the eight other genera of Platyischnopidae by the gnathopods subchelate, and the telson elongate, completely cleft. In addition, the distribution of Tiburonella viscana (Barnard J.L., 1964), up to now known in the South-West Atlantic Ocean from Brazilian waters, is extended to the coast off Buenos Aires province, Argentina.

  2. Giant mudwaves in the Northern Argentine Basin: born and buried by bottom currents

    NASA Astrophysics Data System (ADS)

    Borisov, Dmitrii; Murdmaa, Ivar; Ivanova, Elena; Levchenko, Oleg

    2014-05-01

    New sedimentary records and very high resolution seismic profiles collected during four cruises of the RV "Akademik Ioffe" (2011-2013) were correlated with seismic, multibeam and coring data obtained during cruises of the RV "Robert Conrad", "Knorr", "Meteor". A complex analysis of the geological-geophysical data revealed an extensive field of giant mudwaves (48 000 km2) in the northwestern Argentine Basin, South Atlantic. The symmetric waves up to 60 m in height and 4000 m in wavelength are oriented roughly parallel to contours. They partly cover the Santa Catarina Plateau and extend through the Santos Basin to the Sao Paulo Plateau. The mudwaves field is traced at the depth range from 3400 to 4000 m and divided into buried (northern) and non-buried (southern) parts. The non-buried sediment waves cover the surface of the huge drift in the Santa Catarina Plateau. The wave height increases from the drift summit to its flanks and decreases at the foot. Two cores retrieved from the drift top and its northern flank recovered muddy contourites with a greater amount of silt-size material in the core from the drift flank. The age of the recovered sediments is at least 130 ka. In the northern Santos basin, the sediment waves are buried under a large lens-like sediment body (drift?) inclined at the margins. Cores obtained from the buried part of the mudwaves field recovered an intercalation of hemipelagic clay and silty-clay contourite. The age of recovered sediments does not exceed 150 ka (Bleil et al., 1993). Contourites deposition in the study area is related to the activity of the Antarctic bottom water (AABW) contour current. The AABW flow is considered to be divided into two branches by the Santa Catarina Plateau. We suggest that this topographic obstacle causes a flow velocity increase. Wave height and grain-size variations indicate higher bottom current velocities at the plateau flanks and relative tranquil conditions at the flat summit of the plateau. The symmetric

  3. The Argentine Impact Record: Implications for Episodes of Increased Flux during the Last 10 Myr

    NASA Astrophysics Data System (ADS)

    Harris, R. S.; Schultz, P. H.

    2009-12-01

    Schultz et al. [1-6] have identified 8 impact melt breccia deposits in late Cenozoic strata of the Argentine Pampas. 40Ar/39Ar and fission track dating, combined with sequence and biostratigraphic controls, demonstrate that they represent separate events between 9.24 Ma and 6 ka. These ejecta contain shocked minerals and excavated basement clasts indicative of crater-forming events rather than air blasts. If each involved iron bolides ≤ 50 m across, 8 impacts over ~1.1 x 106 km2 in 10 Myr does not represent an anomaly. However, the melt volumes and distributions observed suggest at least half of the collisions were much larger. One event close to the Miocene-Pliocene boundary (5.28 Ma) appears to have spread microtektites as far as the South Tasman Rise. And three deposits contain meteoritic debris linked to stony and stony-iron asteroids (including HED and angrite-like material) [6,7]. Consequently, one or more increases in the impact flux since the mid-Miocene may be required to account for the Argentine record [8]. Farley et al. [9,10] propose that the disruption of a large main-belt asteroid 8.3 Ma increased the IDP flux in the inner solar system leading to a positive 3He anomaly in late Miocene (~6.8-8.3 Ma) sediments. The anomaly is comparable to the late Eocene (~34.2-36.4 Ma) 3He enhancement attributed to a comet [11] or asteroid [12] shower, which increased both the abundance of IDPs and large asteroids reaching the surface. But Farley et al. discount such a scenario in the late Miocene based on a perceived absence of coincident crater-forming impacts. Preserved ejecta and geochemical signatures, however, indicate the contrary. We suggest that the late Miocene contains at least as rich a record of terrestrial impacts as the late Eocene. The patterns of elevated 3He, main-belt breakups, and significant impact events are very similar through both intervals. Two reported asteroid breakups during the Pliocene and mid-Pleistocene [13,14] also appear to

  4. Major depression in hospitalized Argentine general medical patients: Prevalence and risk factors.

    PubMed

    Yanzón de la Torre, Andrés; Oliva, Nicolás; Echevarrieta, Paula L; Pérez, Bibiana G; Caporusso, Gabriela B; Titaro, Anabella J; Todaro Kicyla, Alejandro; Cuatz, Mariana; Locatelli, Mariana; Nelson, Lucila M; Mac Mullen, Mercedes; Baldessarini, Ross J; Daray, Federico M

    2016-06-01

    Depression is not uncommon among medically hospitalized patients, though reported prevalence has varied widely, often in samples involving elderly patients with particular illnesses. Accordingly, we evaluated risk of major depression in three metropolitan general hospitals in Buenos Aires, in subjects with a range of medical disorders and ages, comparing several standard screening methods to expert clinical examinations. Consecutively hospitalized general medical patients were evaluated over a six-months. Excluded were subjects under age 18 and those unable to participate in assessments because of illness, medication, sensory or speech impairment, or lack of language fluency, or scored <25 on the Mini Mental State Examination (MMSE). Consenting participants were examined for DSM-IV-TR major depression by psychiatrists guided by MINI examinations, compared with other standard screening methods. Risk factors were assessed by preliminary bivariate analyses followed by multivariate logistic regression modeling. Overall prevalence of major depression in 257 subjects was 27% by psychiatric examination. The rate was most similar (25%) with the Hospital Anxiety & Depression Scale (HADS), and much higher with the Beck Depression Inventory-II (BDI, 44%) and Patient Health Questionnaire (PHQ, 56%). Factors associated independently with depression by multivariate modeling included: prior psychotropic-drug treatment, female sex, more children, and heavy smoking. Depression was associated most with neoplastic, urological, and infectious disorders, least with pulmonary, neurological, and hematologic conditions. Modest numbers limited power to test for associations of depression with specific medical conditions. Major depression was identified in over one-quarter of Argentine, general medical inpatients, with marked differences among screening methods. Several risk factors were identified. The findings encourage assertive identification of depression in hospitalized medical

  5. Feeding behavior and social interactions of the Argentine ant Linepithema humile change with sucrose concentration.

    PubMed

    Sola, F J; Josens, R

    2016-08-01

    Liquid sugar baits are well accepted by the Argentine ant Linepithema humile and are suitable for the chemical control of this invasive species. We evaluated how sugar concentrations affect the foraging behavior of L. humile individuals. We quantified feeding variables for individual foragers (ingested load, feeding time and solution intake rate) when feeding on sucrose solutions of different concentrations, as well as post-feeding interactions with nestmates. Solutions of intermediate sucrose concentrations (10-30%) were the most consumed and had the highest intake rates, whereas solutions of high sucrose concentrations (60 and 70%) resulted in extended feeding times, low intake rates and ants having smaller crop loads. In terms of post-feeding interactions, individuals fed solutions of intermediate sucrose concentrations (20%) had the highest probability of conducting trophallaxis and the smallest latency to drop exposure (i.e. lowest time delay). Trophallaxis duration increased with increasing sucrose concentrations. Behavioral motor displays, including contacts with head jerking and walking with a gaster waggle, were lowest for individuals that ingested the more dilute sucrose solution (5%). These behaviors have been previously suggested to act as a communication channel for the activation and/or recruitment of nestmates. We show here that sucrose concentration affects feeding dynamics and modulates decision making related to individual behavior and social interactions of foragers. Our results indicate that intermediate sucrose concentrations (ca. 20%), appear to be most appropriate for toxic baits because they promote rapid foraging cycles, a high crop load per individual, and a high degree of stimulation for recruitment.

  6. Occurrence and fate of pesticides in the Argentine stretch of the Paraguay-Paraná basin.

    PubMed

    Etchegoyen, M A; Ronco, A E; Almada, P; Abelando, M; Marino, D J

    2017-02-01

    The Argentine stretch of the del Plata basin crosses regions devoted to extensive and intensive agriculture mostly with chemical pest control. The utilization of pesticides in the region has increased 900% in the last two decades associated with the introduction of biotech crops and direct-seeding techniques. Our objective was to study the occurrence, concentration, and fate of pesticides in surface water and bottom sediments of the principal tributaries and main watercourse of the Paraguay-Paraná River. We sampled 22 sites in the distal positions of the main affluents and main watercourse of the Paraná and report here results from two monitoring campaigns (2010-2012). Surface water and bottom sediments were analyzed according to standardized methods by matrix-solid-phase dispersion and liquid-liquid extraction, respectively. Twenty-three pesticide compounds were analyzed by gas chromatography. The results from both campaigns indicated a generalized but variable distribution in the concentrations detected throughout the basin. The ranges of total measured pesticide concentrations in water and sediments were, respectively, 0.004-6.62 μg/l and 0.16-221.3 μg/kg dry weight. Endosulfans, cypermethrin, and chlorpyrifos were ubiquitous compounds in both environmental compartments and quantitatively the most relevant. All concentrations detected in water were over the recommended guidelines for the protection of aquatic biota. The partitioning indicated a higher affinity for the sediments. Agricultural activity is the source of pesticide-pollution loads, transported by tributaries that reach the main watercourse and alter the quality of the aquatic ecosystem.

  7. The carbon budget of a large catchment in the Argentine Pampa plain through hydrochemical modeling.

    PubMed

    Glok Galli, M; Martínez, D E; Kruse, E E

    2014-09-15

    Mar Chiquita is a coastal lagoon located in the Argentine Buenos Aires province in South America. The aim of this study is to estimate the annual contribution of inland waters to the carbon cycle in this lagoon's catchment by estimating the corresponding local carbon budget. Fifteen pairs of water samples were chosen to carry out hydrogeochemical modeling using PHREEQC software. Groundwater samples were considered as recharge water (initial solutions), while streamwater samples were taken as groundwater discharge (final solutions for inverse modeling/reference solutions for direct modeling). Fifteen direct models were performed, where each groundwater sample was constrained to calcite equilibrium under two different carbon dioxide partial pressure (PCO2) conditions: atmospheric conditions (log PCO2 (atm) = -3.5) and a PCO2 value of log PCO2 (atm) = -3. Groundwater samples are close to calcite equilibrium conditions. The calcite precipitation process is kinetically slower than gas diffusion, causing oversaturation of this reactant phase in streamwater samples. This was accompanied by a pH increase of approximately two units due to a PCO2 decrease. From the fifteen inverse models it was estimated that, of the total carbon that enters per year in the hydrological cycle of the study area, about 11.9% is delivered to the atmosphere as CO2 and around 6.7% is buried in sediments. This would indicate that 81.4% of the remaining carbon is retained in equilibrium within the system or discharged into the Mar Chiquita lagoon and/or directly to the ocean through regional flows.

  8. Ordovician K-bentonites in the Argentine Precordillera: relations to Gondwana margin evolution

    USGS Publications Warehouse

    Huff, W.D.; Bergstrom, Stig M.; Kolata, Dennis R.; Cingolani, C.A.; Astini, R.A.

    1998-01-01

    This paper is included in the Special Publication entitled 'The proto- Andean margin of Gondwana', edited by R.J. Pankhurst and C.W. Rapela. Ordovician K-bentonites have now been recorded from >20 localities in the vicinity of the Argentine Precordillera. Most occur in the eastern thrust belts, in the San Juan Limestone and the overlying the Gualcamayo Formation, but a few ash beds are known also from the central thrust belts. The oldest occur in the middle Arenig I, victoriae lunatus graptolite (Oe. evae conodont) Zone, and the youngest in the middle Llanvirn P. elegans (P. suecicus) Zone. Mineralogical characteristics, typical of other Ordovician K-bentonites, include a matrix of illite/smectite mixed-layer clay and a typical felsic volcanic phenocryst assemblage: biotite, beta-form quartz, alkali and plagioclase feldspar, apatite, and zircon, with lesser amounts of hornblende, clinopyroxene, titanite and Fe-Ti oxides. The proportions of the mineral phases and variations in their crystal chemistry are commonly unique to individual (or small groups of) K-bentonite beds. Glass melt inclusions preserved in quartz are rhyolitic in composition. The sequence is unique in its abundance of K-bentonite beds, but a close association between the Precordillera and other Ordovician sedimentary basins cannot be established. The ash distribution is most consistent with palaeogeographical reconstructions in which early Ordovician drifting of the Precordillera occurred in proximity to one or more volcanic arcs, and with eventual collision along the Andean margin of Gondwana during the mid-Ordovician Ocloyic event of the Famatinian orogeny. The Puna-Famatina terrane northeast of the Precordillera might have served as the source of the K-bentonite ashes, possibly in concert with active arc magmatism on the Gondwana plate itself.

  9. Rapid diagnosis of Argentine hemorrhagic fever by reverse transcriptase PCR-based assay.

    PubMed Central

    Lozano, M E; Enría, D; Maiztegui, J I; Grau, O; Romanowski, V

    1995-01-01

    Argentine hemorrhagic fever (AHF) is an endemo-epidemic disease caused by Junín virus. This report demonstrates that a reverse transcriptase (RT) PCR-based assay developed in our laboratory to detect Junín virus in whole blood samples is sensitive and specific. The experiments were conducted in a double-blinded manner using 94 clinical samples collected in the area in which AHF is endemic. The RT-PCR-based assay was compared with traditional methodologies, including enzyme-linked immunosorbent assay, plaque neutralization tests, and occasionally viral isolation. The calculated parameters for RT-PCR diagnosis, with seroconversion as the "gold standard," were 98% sensitivity and 76% specificity. It is noteworthy that 94% of the patients with putative false-positive results (RT-PCR positive and no seroconversion detected) exhibited febrile syndromes of undefined etiology. These results could be interpreted to mean that most of those patients with febrile syndromes were actually infected with Junín virus but did not develop a detectable immune response. Furthermore, 8 laboratory-fabricated samples and 25 blood samples of patients outside the area in which AHF is endemic tested in a similar way were disclosed correctly (100% match). The RT-PCR assay is the only laboratory test available currently for the early and rapid diagnosis of AHF. It is sensitive enough to detect the low viremia found during the period in which immune plasma therapy can be used effectively, reducing mortality rates from 30% to less than 1%. PMID:7542268

  10. Practical Pest Management Strategies to Reduce Pesticide Runoff for Argentine Ant (Hymenoptera: Formicidae) Control.

    PubMed

    Greenberg, Les; Rust, Michael K; Richards, Jaben; Wu, Xiaoqin; Kabashima, John; Wilen, Cheryl; Gan, Jay; Choe, Dong-Hwan

    2014-12-01

    The purpose of this study was to involve pest management professionals in the design of application techniques and strategies that would be efficacious and also reduce insecticide runoff. Our study involved measuring both the efficacy of treatments for the Argentine ant, Linepithema humile (Mayr), and the concurrent runoff of fipronil and pyrethroids. Two collaborating companies used low-impact protocols for controlling ants while minimizing runoff. Protocol 1 involved bimonthly treatments, while Protocol 2 was monthly. Both protocols involved an initial treatment with a fipronil spray around the foundation. At the garage door-driveway interface, the fipronil application was done as a pin stream for Protocol 1, and as a crack and crevice application in the expansion joint near the garage for Protocol 2. Protocol 1 replaced most pyrethroid sprays with bifenthrin granules placed around bushes and away from the driveway. For the next treatment on day 63, Protocol 1 also included cyfluthrin spray treatments around the house foundation and crack and crevice applications around the edge of the driveway. For the first treatment in Protocol 2, the fipronil spray was supplemented with spot treatments of cyfluthrin. For subsequent Protocol 2 treatments, botanical insecticides were applied. For weeks 1 and 2 posttreatment combined, Protocol 1 had significantly higher reductions in ant numbers compared with Protocol 2. Thereafter there were no significant differences between the protocols. Runoff of bifenthrin from the granules used with Protocol 1 was much lower than in previous trials involving bifenthrin sprays. Day 1 fipronil runoff for Protocol 2 was significantly lower than that for Protocol 1. This difference may be because of the crack and crevice application applied in Protocol 2. Cyfluthrin runoff was minimal for Protocol 2, which involved spot treatments to supplement the fipronil on day 1, or the botanical insecticides for subsequent treatments. Protocol 1 had a

  11. Individual Rules for Trail Pattern Formation in Argentine Ants (Linepithema humile)

    PubMed Central

    Perna, Andrea; Granovskiy, Boris; Garnier, Simon; Nicolis, Stamatios C.; Labédan, Marjorie; Theraulaz, Guy; Fourcassié, Vincent; Sumpter, David J. T.

    2012-01-01

    We studied the formation of trail patterns by Argentine ants exploring an empty arena. Using a novel imaging and analysis technique we estimated pheromone concentrations at all spatial positions in the experimental arena and at different times. Then we derived the response function of individual ants to pheromone concentrations by looking at correlations between concentrations and changes in speed or direction of the ants. Ants were found to turn in response to local pheromone concentrations, while their speed was largely unaffected by these concentrations. Ants did not integrate pheromone concentrations over time, with the concentration of pheromone in a 1 cm radius in front of the ant determining the turning angle. The response to pheromone was found to follow a Weber's Law, such that the difference between quantities of pheromone on the two sides of the ant divided by their sum determines the magnitude of the turning angle. This proportional response is in apparent contradiction with the well-established non-linear choice function used in the literature to model the results of binary bridge experiments in ant colonies (Deneubourg et al. 1990). However, agent based simulations implementing the Weber's Law response function led to the formation of trails and reproduced results reported in the literature. We show analytically that a sigmoidal response, analogous to that in the classical Deneubourg model for collective decision making, can be derived from the individual Weber-type response to pheromone concentrations that we have established in our experiments when directional noise around the preferred direction of movement of the ants is assumed. PMID:22829756

  12. Development of a sperm cryopreservation protocol for the Argentine black and white tegu (Tupinambis merianae).

    PubMed

    Young, Carly; Ravida, Nicole; Curtis, Michelle; Mazzotti, Frank; Durrant, Barbara

    2017-01-01

    Of the 934 lizard species evaluated by the International Union for the Conservation of Nature (IUCN), at least one-third is threatened with extinction. However, there are no reports of semen cryopreservation efforts for lizards. Invasive Argentine black and white tegus were captured in the Florida Everglades, and sperm was collected postmortem. Initial motility score (IMS; % motile × speed of progression(2) × 100), plasma membrane integrity (IPL), and acrosome integrity (IAC) were recorded. Sperm was diluted in TEST-yolk buffer with a final glycerol or dimethylsulfoxide (DMSO)concentration of 8%, 12%, or 16%, and frozen at 0.3 °C, 1.0 °C, or 6.3 °C/min. At thaw, all variables were expressed as the percentage of initial (%IMS, %IPL, and %IAC). The 0.3 °C freeze rate was more successful than 1.0 °C and 6.3 °C/min in preserving %IMS and %IPL. DMSO preserved %IMS, %IPL, and %IAC better than glycerol. To determine the best overall cryopreservation protocol, a sperm quality index was calculated, giving equal weight to each of the three indicators of cryosurvival. Because there were significant interactions between freeze rate and cryoprotectant concentration, each treatment was compared with all others. The sperm quality index analysis revealed that tegu sperm frozen at 0.3 °C/min with 12% DMSO exhibited the highest postthaw viability compared with all other treatments. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Genetic structure and admixture in urban populations of the Argentine North-West.

    PubMed

    Alfaro, E L; Dipierri, J E; Gutiérrez, N I; Vullo, C M

    2005-01-01

    From the ethnic point of view, the Argentine North-West (ANW) constitutes one of the most noticeable areas in the country due to the cultural peculiarities that integrate it to the Andean world and the ethno-historical and demographic characteristics of how it became populated. The study analysed the genetic structure and diversity of the ANW urban populations, and the contribution of parental populations to its genetic pool. Previously reported data on allele frequencies of HLA-A and HLA-B loci of 1293 individuals from Jujuy, Salta, Tucumán, Santiago del Estero, Catamarca and La Rioja were used. Our estimates include: (a) genetic intra-population diversity; (b) genetic distances between populations; (c) linkage disequilibrium (LD); (d) admixture rates and genetic distances with respect to three parental populations (European, American Indian and African). Low intra-population genetic differentiation and low genetic distances between populations were found. Differential LD distribution varied according to province, with 60% variance due to intra-population differences. The Spanish contribution (50%) predominated in ANW, followed by the American Indian (40%) and African (10%) contributions, and a marked inter-population heterogeneity of genetic admixture rates was observed. The shortest genetic distance was found in the American Indian parental population, and the longest in the African parental population. Five hundred years after the Spanish conquest, urban populations at ANW that have probably been subject to the same evolutionary forces present low genetic diversity and a similar genetic structure. Genetic distances and admixture percentages observed agree with census and ethno-historical data on settlement in the region.

  14. Using return on investment to maximize conservation effectiveness in Argentine grasslands

    PubMed Central

    Murdoch, William; Ranganathan, Jai; Polasky, Stephen; Regetz, James

    2010-01-01

    The rapid global loss of natural habitats and biodiversity, and limited resources, place a premium on maximizing the expected benefits of conservation actions. The scarcity of information on the fine-grained distribution of species of conservation concern, on risks of loss, and on costs of conservation actions, especially in developing countries, makes efficient conservation difficult. The distribution of ecosystem types (unique ecological communities) is typically better known than species and arguably better represents the entirety of biodiversity than do well-known taxa, so we use conserving the diversity of ecosystem types as our conservation goal. We define conservation benefit to include risk of conversion, spatial effects that reward clumping of habitat, and diminishing returns to investment in any one ecosystem type. Using Argentine grasslands as an example, we compare three strategies: protecting the cheapest land (“minimize cost”), maximizing conservation benefit regardless of cost (“maximize benefit”), and maximizing conservation benefit per dollar (“return on investment”). We first show that the widely endorsed goal of saving some percentage (typically 10%) of a country or habitat type, although it may inspire conservation, is a poor operational goal. It either leads to the accumulation of areas with low conservation benefit or requires infeasibly large sums of money, and it distracts from the real problem: maximizing conservation benefit given limited resources. Second, given realistic budgets, return on investment is superior to the other conservation strategies. Surprisingly, however, over a wide range of budgets, minimizing cost provides more conservation benefit than does the maximize-benefit strategy. PMID:21098281

  15. Cardio-metabolic risk factors in Argentine children. A comparative study.

    PubMed

    Figueroa Sobrero, Angela; Evangelista, Patricia; Kovalskys, Irina; Digón, Patricia; López, Stella; Scaiola, Edit; Perez, Norma; Dieuzeide, Guillermo; Walz, Florencia; Mazza, Carmen

    2016-01-01

    Obesity and its complications are emerging in an epidemic manner in Latin American countries. To estimate the prevalence of Cardio-Metabolic Risk Factors (CMRFs) and Metabolic Syndrome (MS) in overweight/obese (OW/OB) and normal weight (NW) adolescents and to examine the associated variables. A cross-sectional comparative study was conducted in two groups of children, between 10 and 19 years of age, in seven Argentine provinces. A survey on dietary habits, physical activity, anthropometric and biochemical data was collected to identify CMRF and MS. The WHO definition adapted to children was used. 1009 children were assessed; 398 were male (39.4%), 601 (59.6%) were NW and 408 (40.4%) were OW/OB. The OW/OB had a significantly higher proportion of values defined as CMRF: 3.7% impaired fasting glucose >110mg/dl; 27.9% insulin >15 or 20μU/l as they were pubertal/prepubertal; 53.2% Homeostatic Model Assessment (HOMA)>2.5; 45.6% High Density Lipoprotein (HDL)<40mg/dl; 37.7% TG>110mg/dl and 13.5% hypertension (SBP and/or diastolic Blood Pressure percentile >90). Prevalence of the MS in OW/OB patients was 40.3%. The MS was not observed in NW children. Significant differences were found for: family history of OW/OB, birth weight (BW), age at menarche, presence of acanthosis nigricans, waist circumference (WC) >90th percentile. The WC was positively correlated with BP, TG, insulin, HOMA and Body mass index Z score and negatively with HDL in the study population. We confirm obesity as a major determinant of CMRF and MS (40%), especially fat centralization. We stress the need to address obesity prevention plans in children and adolescents. Copyright © 2015 Diabetes India. Published by Elsevier Ltd. All rights reserved.

  16. Adaptation to Interannual and Interdecadal Climate Variability in Agricultural Production Systems of the Argentine Pampas

    NASA Astrophysics Data System (ADS)

    Podestá, G. P.; Bert, F.; Weber, E.; Laciana, C.; Rajagopalan, B.; Letson, D.

    2007-05-01

    Agricultural ecosystems play a central role in world food production and food security, and involve one of the most climate-sensitive sectors of society-agriculture. We focus on crop production in the Argentine Pampas, one of the world's major agricultural regions. Climate of the Pampas shows marked variability at both interannual and decadal time scales. We explored the scope for adaptive management in response to climate information on interannual scales. We show that different assumptions about what decision makers are trying to achieve (i.e., their objective functions) may change what actions are considered as "optimal" for a given climate context. Optimal actions also were used to estimate the economic value of forecasts of an ENSO phase. Decision constraints (e.g., crop rotations) have critical influence on value of the forecasting system. Gaps in knowledge or misconceptions about climate variability were identified in open-ended "mental model" interviews. Results were used to design educational interventions. A marked increase in precipitation since the 1970s, together with new production technologies, led to major changes in land use patterns in the Pampas. Continuous cropping has widely replaced agriculture-pasture rotations. Nevertheless, production systems that evolved partly in response to increased rainfall may not be viable if climate reverts to a drier epoch. We use historical data to define a range of plausible climate trajectories 20-30 years hence. Regional scenarios are downscaled using semi-parametric weather generators to produce multiple realizations of daily weather consistent with decadal scenarios. Finally, we use the synthetic climate, crop growth models, and realistic models of decision-making under risk to compute risk metrics (e.g., probability of yields or profits being below a threshold). Climatically optimal and marginal locations show differential responses: probabilities of negative economic results are much higher in currently

  17. Colony fusion in Argentine ants is guided by worker and queen cuticular hydrocarbon profile similarity.

    PubMed

    Vásquez, Gissella M; Schal, Coby; Silverman, Jules

    2009-08-01

    Introduced populations of the Argentine ant, Linepithema humile, have experienced moderate to severe losses of genetic diversity, which may have affected nestmate recognition to various degrees. We hypothesized that cuticular hydrocarbons (CHC) serve as nestmate recognition cues, and facilitate colony fusion of unrelated L. humile colonies that share similar CHC profiles. In this study, we paired six southeastern U.S. L. humile colonies in a 6-month laboratory fusion assay, and determined if worker and queen CHC profile similarity between colonies was associated with colony fusion and intercolony genetic similarity. We also compared worker and queen CHC profiles between fused colony pairs and unpaired controls to determine if worker and queen chemical profiles changed after fusion. We found that colony fusion correlated with the CHC similarity of workers and queens, with the frequency of fusion increasing with greater CHC profile similarity between colonies. Worker and queen CHC profile similarity between colonies also was associated with genetic similarity between colonies. Queen CHC profiles in fused colonies appeared to be a mix of the two colony phenotypes. In contrast, when only one of the paired colonies survived, the CHC profile of the surviving queens did not diverge from that of the colony of origin. Similarly, workers in non-fused colonies maintained their colony-specific CHC, whereas in fused colonies the worker CHC profiles were intermediate between those of the two colonies. These results suggest a role for CHC in regulating interactions among mutually aggressive L. humile colonies, and demonstrate that colony fusion correlates with both genetic and CHC similarities. Further, changes in worker and queen chemical profiles in fused colonies suggest that CHC plasticity may sustain the cohesion of unrelated L. humile colonies that had fused.

  18. An experimental study of competition between fire ants and Argentine ants in their native range.

    PubMed

    LeBrun, E G; Tillberg, C V; Suarez, A V; Folgarait, P J; Smith, C R; Holway, D A

    2007-01-01

    An understanding of why introduced species achieve ecological success in novel environments often requires information about the factors that limit the abundance of these taxa in their native ranges. Although numerous recent studies have evaluated the importance of natural enemies in this context, relatively few have examined how ecological success may result from differences in the magnitude of interference competition between communities in the native and introduced ranges of nonnative species. Here we examine how native-range competitive environments may relate to invasion success for two important invasive species, the red imported fire ant (Solenopsis invicta) and the Argentine ant (Linepithema humile), in a region of native-range sympatry. At two study sites in northern Argentina, we used stable-isotope analysis, a variety of observational approaches, and two different reciprocal removal experiments to test (1) whether S. invicta competes asymmetrically with L. humile (as suggested by the 20th century pattern of replacement in the southeastern United States) and (2) the extent to which these two species achieve behavioral and numerical dominance. Stable-isotope analysis and activity surveys indicated that S. invicta and L. humile are both omnivores and forage during broadly overlapping portions of the diel cycle. Short-term removal experiments at baits revealed no competitive asymmetry between S. invicta and L. humile. Longer-term colony removal experiments illustrated that S. invicta and L. humile experience an approximately equal competitive release upon removal of the other. Our results indicate that neither S. invicta nor L. humile achieves the same degree of behavioral or ecological dominance where they co-occur in native populations as they do in areas where either is common in their introduced range. These results strongly suggest that interspecific competition is an important limiting factor for both S. invicta and L. humile in South America.

  19. Individual rules for trail pattern formation in Argentine ants (Linepithema humile).

    PubMed

    Perna, Andrea; Granovskiy, Boris; Garnier, Simon; Nicolis, Stamatios C; Labédan, Marjorie; Theraulaz, Guy; Fourcassié, Vincent; Sumpter, David J T

    2012-01-01

    We studied the formation of trail patterns by Argentine ants exploring an empty arena. Using a novel imaging and analysis technique we estimated pheromone concentrations at all spatial positions in the experimental arena and at different times. Then we derived the response function of individual ants to pheromone concentrations by looking at correlations between concentrations and changes in speed or direction of the ants. Ants were found to turn in response to local pheromone concentrations, while their speed was largely unaffected by these concentrations. Ants did not integrate pheromone concentrations over time, with the concentration of pheromone in a 1 cm radius in front of the ant determining the turning angle. The response to pheromone was found to follow a Weber's Law, such that the difference between quantities of pheromone on the two sides of the ant divided by their sum determines the magnitude of the turning angle. This proportional response is in apparent contradiction with the well-established non-linear choice function used in the literature to model the results of binary bridge experiments in ant colonies (Deneubourg et al. 1990). However, agent based simulations implementing the Weber's Law response function led to the formation of trails and reproduced results reported in the literature. We show analytically that a sigmoidal response, analogous to that in the classical Deneubourg model for collective decision making, can be derived from the individual Weber-type response to pheromone concentrations that we have established in our experiments when directional noise around the preferred direction of movement of the ants is assumed.

  20. Suspending the next turn as a form of repair initiation: evidence from Argentine Sign Language.

    PubMed

    Manrique, Elizabeth; Enfield, N J

    2015-01-01

    Practices of other-initiated repair deal with problems of hearing or understanding what another person has said in the fast-moving turn-by-turn flow of conversation. As such, other-initiated repair plays a fundamental role in the maintenance of intersubjectivity in social interaction. This study finds and analyses a special type of other-initiated repair that is used in turn-by-turn conversation in a sign language: Argentine Sign Language (Lengua de Señas Argentina or LSA). We describe a type of response termed a "freeze-look," which occurs when a person has just been asked a direct question: instead of answering the question in the next turn position, the person holds still while looking directly at the questioner. In these cases it is clear that the person is aware of having just been addressed and is not otherwise accounting for their delay in responding (e.g., by displaying a "thinking" face or hesitation, etc.). We find that this behavior functions as a way for an addressee to initiate repair by the person who asked the question. The "freeze-look" results in the questioner "re-doing" their action of asking a question, for example by repeating or rephrasing it. Thus, we argue that the "freeze-look" is a practice for other-initiation of repair. In addition, we argue that it is an "off-record" practice, thus contrasting with known on-record practices such as saying "Huh?" or equivalents. The findings aim to contribute to research on human understanding in everyday turn-by-turn conversation by looking at an understudied sign language, with possible implications for our understanding of visual bodily communication in spoken languages as well.

  1. Variations in sediment transport at the central Argentine continental margin during the Cenozoic

    NASA Astrophysics Data System (ADS)

    Gruetzner, Jens; Uenzelmann-Neben, Gabriele; Franke, Dieter

    2012-10-01

    The construction of the sedimentary cover at most passive continental margins includes gravitational downslope transport and along-slope contourite deposition, which are controlled by tectonics, climate and oceanography. At the eastern continental margin of Argentina the history of deposition and erosion is intimately linked to the evolution of the South Atlantic and its water masses. Here we present a detailed seismic investigation of the mixed depositional system located between 41°S and 45°S. The study provides a northward complement to prior investigations from the southern Argentine margin and together with these may be used as background information for future ocean drilling in the region. Prominent features in our seismic cross sections are submarine canyons, mass wasting deposits, contourite channels, and sediment drifts. Four major seismic units above regional reflector PLe (˜65 Ma) are separated by distinct unconformities of regional extent. Using a dense grid of reflection seismic profiles, we mapped the depocenter geometries of the seismic units and derived a chronology of the depositional processes during the Cenozoic. While the Paleocene/Eocene (˜65-34 Ma) is characterized by hemipelagic sedimentation under relatively sluggish bottom water conditions, strong Antarctic bottom water (AABW) circulation led to widespread erosion on the slope and growth of a detached sediment drift during the Oligocene and early Miocene (˜34-17 Ma). After deposition of an aggradational seismic unit interpreted to represent the Mid-Miocene climatic optimum (˜17-14 Ma), gravitational downslope sediment transport increased during the middle to late Miocene (˜14-6 Ma) possibly related to tectonic uplift in South America. The Pliocene to Holocene unit (<˜6 Ma) is very heterogeneous and formed by interactions of downslope and along-slope sediment transport processes as indicated by the evolution of canyons, slope plastered drifts and channels.

  2. Circadian analysis of myocardial infarction incidence in an Argentine and Uruguayan population

    PubMed Central

    D'Negri, Carlos E; Nicola-Siri, Leonardo; Vigo, Daniel E; Girotti, Luis A; Cardinali, Daniel P

    2006-01-01

    Background The occurrence of variations in the spectrum of cardiovascular disease between different regions of the world and ethnic groups have been the subject of great interest. This study report the 24-h variation of myocardial infarction (MI) occurrence in patients recruited from CCU located in Argentina and Uruguay. Methods A cohort of 1063 patients admitted to the CCU within 24 h of the onset of symptoms of an acute MI was examined. MI incidence along the day was computed in 1 h-intervals. Results A minimal MI incidence between 03:00 and 07:00 h and the occurrence of a first maximum between 08:00 and 12:00 h and a second maximum between 15:00 and 22:00 h were verified. The best fit curve was a 24 h cosinor (acrophase ~ 19:00 h, accounting for 63 % of variance) together with a symmetrical gaussian bell (maximum at ~ 10:00 h, accounting for 37 % of variance). A similar picture was observed for MI frequencies among different excluding subgroups (older or younger than 70 years; with or without previous symptoms; diabetics or non diabetics; Q wave- or non-Q wave-type MI; anterior or inferior MI location). Proportion between cosinor and gaussian probabilities was maintained among most subgroups except for older patients who had more MI at the afternoon and patients with previous symptoms who were equally distributed among the morning and afternoon maxima. Conclusion The results support the existence of two maxima (at morning and afternoon hours) in MI incidence in the Argentine and Uruguayan population. PMID:16401349

  3. Suspending the next turn as a form of repair initiation: evidence from Argentine Sign Language

    PubMed Central

    Manrique, Elizabeth; Enfield, N. J.

    2015-01-01

    Practices of other-initiated repair deal with problems of hearing or understanding what another person has said in the fast-moving turn-by-turn flow of conversation. As such, other-initiated repair plays a fundamental role in the maintenance of intersubjectivity in social interaction. This study finds and analyses a special type of other-initiated repair that is used in turn-by-turn conversation in a sign language: Argentine Sign Language (Lengua de Señas Argentina or LSA). We describe a type of response termed a “freeze-look,” which occurs when a person has just been asked a direct question: instead of answering the question in the next turn position, the person holds still while looking directly at the questioner. In these cases it is clear that the person is aware of having just been addressed and is not otherwise accounting for their delay in responding (e.g., by displaying a “thinking” face or hesitation, etc.). We find that this behavior functions as a way for an addressee to initiate repair by the person who asked the question. The “freeze-look” results in the questioner “re-doing” their action of asking a question, for example by repeating or rephrasing it. Thus, we argue that the “freeze-look” is a practice for other-initiation of repair. In addition, we argue that it is an “off-record” practice, thus contrasting with known on-record practices such as saying “Huh?” or equivalents. The findings aim to contribute to research on human understanding in everyday turn-by-turn conversation by looking at an understudied sign language, with possible implications for our understanding of visual bodily communication in spoken languages as well. PMID:26441710

  4. Disabling injuries of the cervical spine in Argentine rugby over the last 20 years

    PubMed Central

    Secin, F. P.; Poggi, E. J.; Luzuriaga, F.; Laffaye, H. A.

    1999-01-01

    OBJECTIVE: To investigate the incidence and risk factors of disabling injuries to the cervical spine in rugby in Argentina. METHODS: A retrospective review of all cases reported to the Medical Committee of the Argentine Rugby Union (UAR) and Rugby Amistad Foundation was carried out including a follow up by phone. Cumulative binomial distribution, chi 2 test, Fisher test, and comparison of proportions were used to analyse relative incidence and risk of injury by position and by phase of play (Epi Info 6, Version 6.04a). RESULTS: Eighteen cases of disabling injury to the cervical spine were recorded from 1977 to 1997 (0.9 cases per year). The forwards (14 cases) were more prone to disabling injury of the cervical spine than the backs (four cases) (p = 0.03). Hookers (9/18) were at highest risk of injury (p < 0.01). The most frequent cervical injuries occurred at the 4th, 5th, and 6th vertebrae. Seventeen of the injuries occurred during match play. Set scrums were responsible for most of the injuries (11/18) but this was not statistically significant (p = 0.44). The mean age of the injured players was 22. Tetraplegia was initially found in all cases. Physical rehabilitation has been limited to the proximal muscles of the upper limbs, except for two cases of complete recovery. One death, on the seventh day after injury, was reported. CONCLUSIONS: The forwards suffered a higher number of injuries than the backs and this difference was statistically significant. The chance of injury for hookers was statistically higher than for the rest of the players and it was particularly linked to scrummaging. However, the number of injuries incurred in scrums was not statistically different from the number incurred in other phases of play. 


 PMID:10027055

  5. CELL WALL VARIABILITY IN THE GREEN SEAWEED CODIUM VERMILARA (BRYOPSIDALES CHLOROPHYTA) FROM THE ARGENTINE COAST(1).

    PubMed

    Fernández, Paula V; Ciancia, Marina; Estevez, José Manuel

    2011-08-01

    Cell wall chemistry in the coencocytic green seaweed Codium vermilara (Olivi) Delle Chiaje (Bryopsidales, Chlorophyta) is well understood. These cell walls are composed of major amounts of neutral β-(1→4)-D-mannans (Mn), sulfated polysaccharides (SPs), which include pyranosic arabinan sulfates (ArpS), pyruvylated galactan sulfates (pGaS), and mannan sulfates (MnS); also minor amounts of O-glycoproteins are present. In this study, cell wall samples of C. vermilara were investigated with regard to their monosaccharide composition and infrared spectra (using Fourier transform infrared spectroscopy coupled to principal component [FTIR-PC] analysis). Samples from three different populations of C. vermilara from the Argentine coast showed: (i) an important variation in the relative arabinan content, which increases from north to south, and (ii) a measurable degree of cell wall variability in the sulfate distribution between the different sulfated polysaccharides, independent of the amount of each polysaccharide present and of total sulfate content. When cell wall composition was analyzed over three consecutive years in a single geographic location, the quantity of Mn and overall sulfate content on SPs remained constant, whereas the pGaS:ArpS molar ratio changed over the time. Besides, similar cell wall composition was found between actively growing and resting zones of the thallus, suggesting that cell wall composition is independent of growth stage and development. Overall, these results suggest that C. vermilara has developed a mechanism to adjust the total level of cell wall sulfation by modulating the ArpS:pGaS:MnS molar ratio and also by adjusting the sulfation level in each type of polymer, whereas nonsulfated Mn, as the main structural polysaccharide, did not change over the time or growing stage.

  6. Disabling injuries of the cervical spine in Argentine rugby over the last 20 years.

    PubMed

    Secin, F P; Poggi, E J; Luzuriaga, F; Laffaye, H A

    1999-02-01

    To investigate the incidence and risk factors of disabling injuries to the cervical spine in rugby in Argentina. A retrospective review of all cases reported to the Medical Committee of the Argentine Rugby Union (UAR) and Rugby Amistad Foundation was carried out including a follow up by phone. Cumulative binomial distribution, chi 2 test, Fisher test, and comparison of proportions were used to analyse relative incidence and risk of injury by position and by phase of play (Epi Info 6, Version 6.04a). Eighteen cases of disabling injury to the cervical spine were recorded from 1977 to 1997 (0.9 cases per year). The forwards (14 cases) were more prone to disabling injury of the cervical spine than the backs (four cases) (p = 0.03). Hookers (9/18) were at highest risk of injury (p < 0.01). The most frequent cervical injuries occurred at the 4th, 5th, and 6th vertebrae. Seventeen of the injuries occurred during match play. Set scrums were responsible for most of the injuries (11/18) but this was not statistically significant (p = 0.44). The mean age of the injured players was 22. Tetraplegia was initially found in all cases. Physical rehabilitation has been limited to the proximal muscles of the upper limbs, except for two cases of complete recovery. One death, on the seventh day after injury, was reported. The forwards suffered a higher number of injuries than the backs and this difference was statistically significant. The chance of injury for hookers was statistically higher than for the rest of the players and it was particularly linked to scrummaging. However, the number of injuries incurred in scrums was not statistically different from the number incurred in other phases of play.

  7. Study of the TP53 codon 72 polymorphism in oral cancer and oral potentially malignant disorders in Argentine patients.

    PubMed

    Zarate, Ana Maria; Don, Julieta; Secchi, Dante; Carrica, Andres; Galindez Costa, Fernanda; Panico, Rene; Brusa, Martin; Barra, José Luis; Brunotto, Mabel

    2017-05-01

    The aim of this work was to evaluate the prevalence of TP53Arg72Pro mutations and their possible relationship with oral carcinoma and oral potentially malignant disorders in Argentine patients. A cross-sectional study was performed on 111 exfoliated cytologies from patients with oral cancer (OC), oral potentially malignant disorders (OPMD) and controls. The TP53Arg72Pro mutations were determined using conventional PCR. We evaluated univariate and multivariate study variables, setting p < 0.05. We found: (a) a low frequency of Pro72 variant in control group and a high frequency in OC and OPMD, as well in OC and oral leukoplakia (OL) diagnosis; (b) multivariate association among the TP53CC genotype and females over 45 years with no tobacco nor alcohol habits with oral lichen planus pathology; (c) multivariate association between the TP53GC genotype and males with alcohol and tobacco habits and OC and OL pathologies. Our results showed that the wild-type Arg72variant was related to control patients and Pro72variant was related to OC and OPMD, in Argentine patients.

  8. Deglacial changes in the strength of deep southern component water and sediment supply at the Argentine continental margin

    NASA Astrophysics Data System (ADS)

    Warratz, Grit; Henrich, Rüdiger; Voigt, Ines; Chiessi, Cristiano M.; Kuhn, Gerhard; Lantzsch, Hendrik

    2017-08-01

    The deep southern component water (SCW), comprising Lower Circumpolar Deep Water (LCDW) and Antarctic Bottom Water (AABW), is a major component of the global oceanic circulation. It has been suggested that the deep Atlantic water mass structure changed significantly during the last glacial/interglacial cycle. However, deep SCW source-proximal records remain sparse. Here we present three coherent deep SCW paleocurrent records from the deep Argentine continental margin shedding light on deep water circulation and deep SCW flow strength in the Southwest Atlantic since the Last Glacial Maximum (LGM). Based on increased sortable silt values, we propose enhanced deep SCW flow strength from 14 to 10 cal ka B.P. relative to the early deglacial/LGM and the Holocene. We propose a direct influence of deep northern component water (NCW) on deep SCW flow strength due to vertical narrowing of deep SCW spreading, concurrent with a migration of the high-energetic LCDW/AABW interface occupying our core sites. We suggest a shoaled NCW until 13 cal ka B.P., thereby providing space for deep SCW spreading that resulted in reduced carbonate preservation at our core sites. Increased carbonate content from 13 cal ka B.P. indicates that the NCW expanded changing deep water properties at our core sites in the deep Southwest Atlantic. However, southern sourced terrigenous sediments continued to be deposited at our core sites, suggesting that deep SCW flow was uninterrupted along the Argentine continental margin since the LGM.

  9. Eddy-driven sediment transport in the Argentine Basin: Is the height of the Zapiola Rise hydrodynamically controlled?

    DOE PAGES

    Weijer, Wilbert; Maltrud, Mathew E.; Homoky, William B.; ...

    2015-03-27

    In this study, we address the question whether eddy-driven transports in the Argentine Basin can be held responsible for enhanced sediment accumulation over the Zapiola Rise, hence accounting for the existence and growth of this sediment drift. To address this question, we perform a 6 year simulation with a strongly eddying ocean model. We release two passive tracers, with settling velocities that are consistent with silt and clay size particles. Our experiments show contrasting behavior between the silt fraction and the lighter clay. Due to its larger settling velocity, the silt fraction reaches a quasisteady state within a few years,more » with abyssal sedimentation rates that match net input. In contrast, clay settles only slowly, and its distribution is heavily stratified, being transported mainly along isopycnals. Yet, both size classes display a significant and persistent concentration minimum over the Zapiola Rise. We show that the Zapiola Anticyclone, a strong eddy-driven vortex that circulates around the Zapiola Rise, is a barrier to sediment transport, and hence prevents significant accumulation of sediments on the Rise. We conclude that sediment transport by the turbulent circulation in the Argentine Basin alone cannot account for the preferred sediment accumulation over the Rise. We speculate that resuspension is a critical process in the formation and maintenance of the Zapiola Rise.« less

  10. Interaction between the Hawaiian dark-rumped petrel and the Argentine ant in Haleakala National Park, Maui, Hawaii

    USGS Publications Warehouse

    Krushelnycky, Paul D.; Hodges, Cathleen S.N.; Medeiros, Arthur C.; Loope, Lloyd L.

    2001-01-01

    The endemic biota of the Hawaiian islands is believed to have evolved in the absence of ant predation. However, it was suspected that this endemic biota is highly vulnerable to the effect of immigrant ants especially with regard to an aggressive predator known as the Argentine ant (Linepithema humile). First recorded in the Haleakala National Park on the island of Maui in 1967, this ant was believed to have reduced populations of native arthropods in high-elevation subalpine shrublands. In addition, concerns were raised that this immigrant ant may have also reduced the breeding success of the endangered Hawaiian Dark-rumped Petrel (Pterodroma phaeopygia sandwichensis), a native seabird. If so, then it was believe that this ant could become another major threat to the survival of this endangered seabird in addition to the threat that was caused by the introduction of introduced mammals, the advent of hunting by the Polynesians, and a loss of breeding habitat. As a result, the purpose of this study was to determine if the Argentine ant affects the nesting success of this native Hawaiian seabird.

  11. A paleomagnetic and relative paleointensity record from the Argentine Basin (western South Atlantic Ocean) for the last ~125 kyrs

    NASA Astrophysics Data System (ADS)

    Heil, C. W., Jr.; Stoner, J. S.; St-Onge, G.; King, J. W.

    2015-12-01

    The paucity of paleomagnetic records from the western South Atlantic Ocean presents a significant gap in our understanding of the spatial variations in geomagnetic field dynamics as they relate to the occurrence of geomagnetic excursions and changes in field strength. As such, high quality records from this region can help build upon Holocene observations and extend the geographic and temporal data coverage for spherical harmonic models. To that end, we present paleomagnetic directional (inclination) and strength (relative paleointensity) records from two cores from the Argentine Basin (RC11-49 and RC16-88). Although the cores were collected more than 40 years ago, the sediments appear to hold a stable remanence and reliable magnetic directions, as evidenced by their reproducibility between the two cores that are separated by ~25 km. The records show evidence of 4 excursional features in the uppermost 16-m of the sediments from the basin. A comparison of the relative paleointensity records from these cores to the South Atlantic Paleointensity Stack (SAPIS) (Stoner et al., 2002) and the relative paleointensity record from ODP Site 1089 (Stoner et al., 2003) indicate that the sediments reliably record relative changes in geomagnetic field intensity and suggests that the longest record (RC11-49) spans the last ~125 kyrs. Our results indicate that the sediments of the Argentine Basin are an important sedimentary archive of geomagnetic field behavior and strength at least through the Holocene and Late Pleistocene and highlight the need for further studies of cores within the basin.

  12. An oral bioassay for the toxicity of hydramethylnon to individual workers and queens of Argentine ants, Linepithema humile.

    PubMed

    Hooper-Bùi, L M; Rust, M K

    2001-11-01

    We have developed an oral bioassay to determine the toxicity of hydramethylnon to individual workers and queens of the Argentine ant, Linepithema humile. We fed seven concentrations of hydramethylnon in suspension to individual workers or queens, determined the amount of hydramethylnon ingested and evaluated the individual ants for mortality 14 days later. At concentrations > or = 0.37 g liter-1, the amount of liquid the queens ingested decreased dramatically, indicating that Argentine ant queens may detect hydramethylnon. Significantly larger volumes of the two highest concentrations of the hydramethylnon suspension were ingested by the workers, compared to the lower concentrations, suggesting that hydramethylnon may act as a feeding stimulant for the workers. Worker mortality was higher than queen mortality at the highest concentrations tested. The highest worker mortality resulted when the ants ingested 1.03 micrograms of hydramethylnon per mg of ant tissue. At the highest concentration (1.0 g liter-1) tested, workers ingested almost 12 times as much active ingredient per mg of body weight as did queens, suggesting that, in order to increase mortality of queens, multiple feedings must occur.

  13. Relationships among native and introduced populations of the Argentine ant (Linepithema humile) and the source of introduced populations.

    PubMed

    Tsutsui, N D; Suarez, A V; Holway, D A; Case, T J

    2001-09-01

    The Argentine ant (Linepithema humile) is a damaging invasive species that has become established in many Mediterranean-type ecosystems worldwide. To identify likely sources of introduced populations we examined the relationships among native Linepithema populations from Argentina and Brazil and introduced populations of L. humile using mitochondrial cytochrome b sequence data and nuclear microsatellite allele frequencies. The mitochondrial phylogeny revealed that the populations in Brazil were only distantly related to both the introduced populations and the native populations in Argentina, and confirmed that populations in Brazil, previously identified as L. humile, are likely a different species. The microsatellite-based analysis provided resolution among native and introduced populations of L. humile that could not be resolved using the mitochondrial sequences. In the native range, colonies that were geographically close to one another tended to be genetically similar, whereas more distant colonies were genetically different. Most samples from the introduced range were genetically similar, although some exceptions were noted. Most introduced populations were similar to native populations from the southern Rio Parana and were particularly similar to a population from Rosario, Argentina. These findings implicate populations from the southern Rio Parana as the most likely source of introduced populations. Moreover, these data suggest that current efforts to identify natural enemies of the Argentine ant for biological control should focus on native populations in the southern Rio Parana watershed.

  14. Declaration of local chemical eradication of the Argentine ant: Bayesian estimation with a multinomial-mixture model.

    PubMed

    Sakamoto, Yoshiko; Kumagai, Naoki H; Goka, Koichi

    2017-06-13

    Determining the success of eradication of an invasive species requires a way to decide when its risk of reoccurrence has become acceptably low. In Japan, the area populated by the Argentine ant, Linepithema humile (Mayr), is expanding, and eradication via chemical treatment is ongoing at various locations. One such program in Tokyo was apparently successful, because the ant population decreased to undetectable levels within a short time. However, construction of a population model for management purposes was difficult because the probability of detecting ants decreases rapidly as the population collapses. To predict the time when the ant was eradicated, we developed a multinomial-mixture model for chemical eradication based on monthly trapping data and the history of pesticide applications. We decided when to declare that eradication had been successful by considering both 'eradication' times, which we associated with eradication probabilities of 95% and 99%, and an optimal stopping time based on a 'minimum expected economic cost' that considered the possibility that surveys were stopped too soon. By applying these criteria, we retroactively declared that Argentine ants had been eradicated 38-42 months after the start of treatments (16-17 months after the last sighting).

  15. Risk of introducing viral hemorrhagic septicemia virus (VHSV) to the Chilean South Pacific via sardine imports from Europe.

    PubMed

    Hervé-Claude, Luis Pablo; Carpenter, Tim E; Hedrick, Ronald P

    2008-01-24

    Chile imports from Spain 100s of metric tons of frozen sardine Sardina pilchardus fished in European oceans, which, with several other clupeids, are presumed susceptible to infection with viral hemorrhagic septicemia virus (VHSV). The frozen sardines are directly introduced into the sea as bait to catch southern hake Merluccius australis in the same areas where wild and pen-raised salmonids are present. A simulation model was therefore developed to evaluate the potential risk of infection of wild Chilean southern hake with VHSV from imported bait. The model indicated that VHSV-susceptible fish species present in Chilean waters, like southern hake, are not at immediate risk of infection. However, sensitivity analyses showed that infectious doses at lower concentrations of VHSV combined with higher VHSV-prevalence import scenarios could likely result in VHSV infections of a moderate number of indigenous southern hake (> or =54 fish yr(-1)).

  16. Hydroacoustical evidence of the expansion of pelagic swarms of Munida gregaria (Decapoda, Munididae) in the Beagle Channel and the Argentine Patagonian Shelf, and its relationship with habitat features

    NASA Astrophysics Data System (ADS)

    Diez, Mariano J.; Cabreira, Ariel G.; Madirolas, Adrián; Lovrich, Gustavo A.

    2016-08-01

    Squat lobsters are highly diversified and widespread decapods, of which only three species form pelagic swarms. Here we infer the expansion of Munida gregaria populations in the Beagle Channel and the Argentine Patagonian Shelf by means of acoustic surveys of pelagic swarms. We also describe the habitat characteristics in which these swarms occur. Acoustic data was collected during three multidisciplinary scientific cruises on board of the R/V Puerto Deseado during 2009, 2012 and 2014. Despite differences in the environmental conditions between the two surveyed areas, between 2009 and 2014 pelagic swarms increased their occurrence and abundance both in the Beagle Channel and on the Argentine Patagonian Shelf. Towards the end of the studied period, pelagic swarms of M. gregaria occurred in new locations, supporting the notion of a population expansion. Within the Beagle Channel swarm expansions were more marked than on the Patagonian Shelf. We here postulate that M. gregaria expansions occur in association with productive areas of the Argentine continental shelf, such as frontal zones, favoured by the squat lobster phenotypic plasticity that permit to exploit resources in both the neritic and benthic environments. At a regional scale on the Patagonian Shelf, three main groups of pelagic swarms of M. gregaria were clearly associated to respective frontal zones. The information presented here is necessary to understand fluctuations in both distribution and abundance patterns of a key species on the Argentine continental shelf. These fluctuations could be direct or indirect indicators of changes in the ecosystem.

  17. Argentine tango in Parkinson disease--a systematic review and meta-analysis.

    PubMed

    Lötzke, Désirée; Ostermann, Thomas; Büssing, Arndt

    2015-11-05

    Parkinson's Disease (PD) is a neurodegenerative disease with increasing motor and non-motor symptoms in advanced stages. In addition to conventional exercise therapy and drug treatment, Argentine Tango (AT) is discussed as an appropriate intervention for patients to improve physical functioning and health-related quality of life. This review aimed to summarize the current research results on the effectiveness of AT for individuals with PD. The global literature search with the search terms "(Parkinson OR Parkinson's disease) AND tango" was conducted in PubMED, AMED, CAMbase, and Google Scholar for publications in English and German. There were no limitations on the study design, year of publication, stage of disease, considered outcome or the age of participants. Thirteen studies met the inclusion criteria. These included 9 randomized-controlled trials, one non-randomized trial, two case studies and one uncontrolled pre-post study. Our meta-analysis revealed significant overall effects in favor of tango for motor severity measured with the Unified Parkinson's Disease Rating Scale 3 (ES = -0.62, 95 % CI [-.1.04, -0.21]), balance as measured with the Mini-BESTest (ES = 0.96 [0.60, 1.31]) or Berg Balance Scale (ES = 0.45 [0.01, 0.90]), and gait with the Timed Up and Go Test (ES = -.46 [-0.72, -0.20]). However, gait as measured with a 6-Minute Walk Test did not demonstrate statistical significance (ES = 0.36 [-0.06, 0.77]). For freezing of gait, no significant effects were observed in favor of AT (ES = 0.16 [-.62, 0.31]). Further, our systematic review revealed a tendency for positive effects on fatigue, activity participation and Parkinson-associated quality of life. A limitation of the studies is the small number of participants in each study (maximum 75). Moreover, most studies are from the same research groups, and only a few are from other researchers. Future studies should enroll more individuals and should also focus on long-term effects. In addition, future

  18. The Pacific-Atlantic connection: Biogeochemical signals in the southern end of the Argentine shelf

    NASA Astrophysics Data System (ADS)

    Garzón, J. E. Cardona; Martínez, A. M.; Barrera, F.; Pfaff, F.; Koch, B. P.; Freije, R. H.; Gómez, E. A.; Lara, R. J.

    2016-11-01

    The Cape Horn Current transports low-salinity waters from the SE Pacific Ocean into the Atlantic, which are transported further north by the Malvinas current. Biogeochemical signals of this connection were studied by characterization of dissolved organic matter (DOM) by determination of dissolved organic carbon (DOC), fluorescent dissolved organic matter (FDOMc), and DOM humification index (HIX). Further, inorganic nutrients, salinity, temperature, stable isotopic composition of particulate organic nitrogen (δ15N) and chlorophyll a (Chla) were measured in the southern end of the Argentine shelf in March 2012. Three water types were characterized: waters of the Beagle Channel (BCW), coastal waters (CW) and oceanic waters (OW). Highest values of ammonium, DOC, FDOMc and HIX were found in BCW, the lowest in OW, suggesting that terrigenous input is a main source of ammonium and refractory carbon, which is supported by a highly significant inverse correlation of these parameters with salinity. In turn, lowest concentrations of nitrate, silicate and phosphate were found in BCW and CW, and highest in OW, with highly significant correlations of these nutrients with salinity, indicating the contribution of the saltier, nutrient-rich Antarctic Circumpolar Current (ACC) to the Pacific-Atlantic connection system. In general there was an inverse distribution pattern between Chla and those nutrients contributed by the ACC, which is consistent with the transition from coastal waters to the low-silicate, high-nitrate, low-chlorophyll, iron-limited setting of the Subantarctic oceanic waters north of the Polar Front. In contrast, in the low-salinity, internal BCW, high values of ammonium, DOC, HIX and FDOM indicate continental inputs, likely including iron complexes, which could have led to the observed high Chla values. δ15N values were positive in the study region, and same as ammonium, reached a maximum in the inner part of the BCW, declining towards OW. This does not support a

  19. Quantifying sediment dynamics on alluvial fans, Iglesia basin, south Central Argentine Andes

    NASA Astrophysics Data System (ADS)

    Harries, Rebekah; Kirstein, Linda; Whittaker, Alex; Attal, Mikael; Peralta, Silvio

    2017-04-01

    Qualitative interpretations of environmental change drawn from alluvial fan stratigraphy typically tie the deposition of greater volumes of coarser sediment to wetter climatic periods. For example, step changes in sediment flux and discharge associated with glacial-interglacial cycles are often linked to the progradation and back stepping of a fan's toe (Harvey et al, 2002). Indeed, more recent quantitative stratigraphic models demonstrate changes in the volume and calibre of sediment fluxed from an uplifted catchment can produce predictable shifts in the rate at which fluvial deposits fine downstream (Duller et al. 2010, Armitage et al. 2011). These interpretations, however, make three important assumptions: 1) the volume and calibre of the sediment transferred from an eroding mountain belt to a depositional basin is directly related to climate through some value of time-averaged discharge or catchment wetness; 2) lateral sources of sediment, such as tributaries, do not significantly influence the pattern of deposition in a basin and, similarly, 3) the reworking of older fan surfaces is minimal and does not impact the depositional pattern of younger deposits. Here we demonstrate each of these assumptions underestimates the importance of variance in transportable grain sizes in influencing the local and basin-wide deposited grain size trends. Using the Iglesia basin in the Argentine south Central Andes as a natural laboratory, we compare three large, adjacent, alluvial fan systems whose catchments experience the same background tectonic and climatic forcing. We find regional climate forcing is not expressed uniformly in the downstream grain size fining rates of their modern systems. Furthermore, we observe the variance in transportable grain sizes supplied from each primary catchment and the variance of material introduced by tributaries and fan surfaces downstream can act as first order controls on the rate of downstream fining. We also raise the importance of

  20. Sulfur cycling in an iron oxide-dominated, dynamic marine depositional system: The Argentine continental margin

    NASA Astrophysics Data System (ADS)

    Riedinger, Natascha; Brunner, Benjamin; Krastel, Sebastian; Arnold, Gail L.; Wehrmann, Laura M.; Formolo, Michael J.; Beck, Antje; Bates, Steven M.; Henkel, Susann; Kasten, Sabine; Lyons, Timothy W.

    2017-05-01

    The interplay between sediment deposition patterns, organic matter type and the quantity and quality of reactive mineral phases determines the accumulation, speciation and isotope composition of pore water and solid phase sulfur constituents in marine sediments. Here, we present the sulfur geochemistry of siliciclastic sediments from two sites along the Argentine continental slope—a system characterized by dynamic deposition and reworking, which result in non-steady state conditions. The two investigated sites have different depositional histories but have in common that reactive iron phases are abundant and that organic matter is refractory—conditions that result in low organoclastic sulfate reduction rates. Deposition of reworked, isotopically light pyrite and sulfurized organic matter appear to be important contributors to the sulfur inventory, with only minor addition of pyrite from organoclastic sulfate reduction above the sulfate-methane transition (SMT). Pore-water sulfide is limited to a narrow zone at the SMT. The core of that zone is dominated by pyrite accumulation. Iron monosulfide and elemental sulfur accumulate above and below this zone. Iron monosulfide precipitation is driven by the reaction of low amounts of hydrogen sulfide with ferrous iron and is in competition with the oxidation of sulfide by iron (oxyhydr)oxides to form elemental sulfur. The intervals marked by precipitation of intermediate sulfur phases at the margin of the zone with free sulfide are bordered by two distinct peaks in total organic sulfur. Organic matter sulfurization appears to precede pyrite formation in the iron-dominated margins of the sulfide zone, potentially linked to the presence of polysulfides formed by reaction between dissolved sulfide and elemental sulfur. Thus, SMTs can be hotspots for organic matter sulfurization in sulfide-limited, reactive iron-rich marine sedimentary systems. Furthermore, existence of elemental sulfur and iron monosulfide phases meters

  1. Occurrence of Mislabelling in Prepared Fishery Products in Southern Italy.

    PubMed

    Tantillo, Giuseppina; Marchetti, Patrizia; Mottola, Anna; Terio, Valentina; Bottaro, Marilisa; Bonerba, Elisabetta; Bozzo, Giancarlo; Di Pinto, Angela

    2015-06-30

    Fish authentication is a major concern not only for the prevention of commercial fraud, but also for the assessment of safety risks deriving from the undeclared introduction of potentially dangerous toxic or allergenic substances or environmentally damaging fish where endangered species are involved. Moreover, food authentication might affect the diet of certain groups of consumers, such as followers of religious practices. Considering the authentication of fish products is one of the key issues in food safety, quality and sustainability, the aim of this work was to investigate the prevalence of mislabelling in sole (Solea solea), plaice (Pleuronectes platessa), Atlantic salmon (Salmo salar), and hake (Merluccius merluccius) fillets from markets and supermarkets located in Apulia (Southern Italy) using DNA barcoding. The results of the molecular investigations reveal that 42/98 (42.8%) fillet samples were not correctly labelled. In particular, 12/27 (44.4%) fillets of sole (Solea solea) were identified as belonging to Solea senegalensis. In addition, 13/28 (46.4%) plaice (Pleuronectes platessa) samples were identified as Pangasius hypophtalmus. All Atlantic salmon (Salmo salar) samples were correctly labelled. Post-sequencing data analysis revealed that 17/30 (56.6%) hake fillets (Merluccius merluccius) were not correctly labelled, of which 8/30 samples identified as Merluccius hubbsi, 5/30 samples as Merluccius products and 4/30 as Merluccius capensis. The study reveals a high occurrence of species mislabelling in the prepared fish fillet products, further evidence of the need for increased traceability and assessment of the authenticity of food products.

  2. Species composition and biogeography of diatoms in antarctic and subantarctic (Argentine shelf) waters (37-76°S)

    NASA Astrophysics Data System (ADS)

    Olguín, Héctor F.; Alder, Viviana A.

    2011-03-01

    A large spatial scale study of the diatom species inhabiting waters from the subantarctic (Argentine shelf) to antarctic was made for the first time in order to understand the relationships between these two regions with regard to the fluctuations in diatom abundances in relation with environmental features, their floristic associations and the effect of the Polar Front as a biogeographic barrier. Species-specific diatom abundance, nutrient and chlorophyll- a concentration were assessed from 64 subsurface oceanographic stations carried out during the austral summer 2002, a period characterized by an anomalous sea-ice coverage corresponding to a "warm year". Significant relationships of both diatom density and biomass with chlorophyll- a (positive) and water temperature (negative) were found for the study area as a whole. Within the Subantarctic region, diatom density and biomass values were more uniform and significantly (in average: 35 and 11 times) lower than those of the Antarctic region, and did not correlate with chlorophyll- a. In antarctic waters, instead, biomass was directly related with chlorophyll- a, thus confirming the important contribution of diatoms to the Antarctic phytoplanktonic stock. A total of 167 taxa were recorded for the entire study area, with Chaetoceros and Thalassiosira being the best represented genera. Species richness was maximum in subantarctic waters (46; Argentine shelf) and minimum in the Antarctic region (21; Antarctic Peninsula), and showed a significant decrease with latitude. Floristic associations were examined both qualitatively (Jaccard Index) and quantitatively (correlation) by cluster analyses and results allowed differentiating a similar number of associations (12 vs. 13, respectively) and two main groups of stations. In the Drake Passage, the former revealed that the main floristic change was found at the Polar Front, while the latter reflected the Southern ACC Front as a main boundary, and yielded a higher number of

  3. Dubinectes infirmus, a new species of deep-water Munnopsidae (Crustacea, Isopoda, Asellota) from the Argentine Basin, South Atlantic Ocean

    PubMed Central

    Malyutina, Marina; Brandt, Angelika

    2011-01-01

    Abstract Dubinectes infirmus sp. n., Munnopsidae, is described from the Argentine Basin, southwest Atlantic, at depths between 4586–4607 m. The new species is distinguished by a narrow rim of the pleotelson posterior margin which is not raising over its dorsal surface; article 3 of the antennula is subequal in length to article 2; distomedial lobes of male pleopod 1 are of same size as distolateral lobes; stylet of male pleopod 2 is subequal in length to protopod; uropod exopod is more than a half of endopod length. Some generic characters which are weakly pronounced in the new species or have different state are defined more precisely in the revised diagnosis of Dubinectes. The modified diagnosis of the genus, a key to the species of Dubinectes as well as the distribution of the genus are presented. PMID:22207784

  4. [Prevalence and evolution of helmet use in motorcycle riders in an Argentine city (Mar del Plata, 2006-2014)].

    PubMed

    Tosi, Jeremías David; Ledesma, Ruben Daniel; Poó, Fernando Martín; Montes, Silvana Andrea; López, Soledad Susana

    2016-03-01

    Traffic collisions involving motorcyclists are a growing problem in low and middle income countries. Helmet use is the foremost protective measure for this group of road users, however many riders do not wear them. The objective of the present study is to report the changes in helmet use during the period 2006-2014 in an Argentine city and discover associated factors for the year 2014. The sample includes more than 6,900 observations of motorcyclists carried out during the years 2006 (n=962), 2008 (n=977), 2012 (n=2,542), and 2014 (n=2,466). The data indicates a progressive increase in helmet use over time, but differences due to gender and type of rider remain. Factors associated to helmet use in motorcycle drivers during 2014 were: passenger helmet use, motorcycle type, license plate use and gender. Although the results are positive, it is necessary to be attentive to the negative consequences of the growing fleet of motorcycles.

  5. Environmental radiation dosimetry at Argentine Antarctic Marambio Base (64° 13' S, 56° 43' W): preliminary results.

    PubMed

    Zanini, Alba; Ciancio, Vicente; Laurenza, Monica; Storini, Marisa; Esposito, Adolfo; Terrazas, Juan Carlos; Morfino, Paolo; Liberatore, Alessandro; Di Giovan, Gustavo

    2017-09-01

    The preliminary results obtained in the first environmental radiation dosimetry campaign performed in the Antarctic region are presented. This experiment is carried out in the framework of CORA (COsmic Rays in Antarctica) Project, a collaboration between Argentine and Italian institutions. After a feasibility study performed in the Antarctic summer 2013, a new campaign has been carried out, started in March 2015, to measure various components of cosmic ray induced secondary atmospheric radiation at the Argentine Marambio Base (Antarctica; 196 m a.s.l., 64°13' S, 56°43' W). Due to a very few dosimetric data available in literature at high southern latitudes, accurate measurements are performed by using a set of different active and passive detectors. Special attention is dedicated to measure the neutron ambient dose equivalent in different energy ranges, by using an active detector, the Atomtex Rem Counter, for neutron energy between 0.025 eV-14 MeV and a set of passive bubble dosimeters, sensitive to thermal neutrons and neutrons in the energy range 100 keV-20 MeV. The results obtained in the first six months of measurements for X and γ radiation and for low and intermediate energy neutrons (En ≤ 20 MeV) are presented in this paper and show that at high latitude, also at sea level and at distance from the South Magnetic Pole, the ambient dose equivalent is significant, in particular for the high contribution of neutron component. This involves that at higher altitude (i.e. Antarctic Plateau, over 3000 m a.s.l.) the yearly ambient dose equivalent could be higher than the limit of 1 mSv recommended for general public by the International Commission on Radiological Protection (ICRP). Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Physical fitness and future cardiovascular risk in argentine children and adolescents: an introduction to the ALPHA test battery.

    PubMed

    Secchi, Jeremías David; García, Gastón César; España-Romero, Vanesa; Castro-Piñero, José

    2014-04-01

    A high level of physical fitness is associated with cardiovascular health in children and adolescents. At present, there is no systematic implementation of a test battery to assess physical fitness at schools in Argentina. The main objective of this study was to implement the ALPHA test battery to determine the physical fitness of a sample made up of Argentine children and adolescents and to establish the proportion of subjects whose aerobic capacity is indicative of future cardiovascular risk. A sample of 1867 participants (967 girls) aged 6 to 19.5 years old assessed using the ALPHA test battery. Four components of physical fitness were measured: 1) morphological component: height, body weight, and waist circumference; 2) musculoskeletal component: standing long jump test; 3) motor component: speed/agility test (4x10 m shuttle run); 4) cardiorespiratory component: course-navette 20 m, shuttle run test and estimation of maximal oxygen consumption. The 5th, 25th, 50th, 75th, and 95th percentiles were estimated for the main tests. The mean body mass index was 20.8 kg/m2, and 7.8% of participants were classified as obese. In ddition, male participants had a better performance in all physical fitness tests when compared to girls (p< 0.001). An aerobic capacity indicative of cardiovascular risk was observed in 31.6% of all participants. Argentine male children and adolescents included in the sample showed higher levels of physical fitness. Such differences increase with age. Approximately one every three participants had an aerobic capacity indicative of future cardiovascular risk.

  7. A community-based Argentine tango dance program is associated with increased activity participation among individuals with Parkinson disease

    PubMed Central

    Foster, Erin R.; Golden, Laura; Duncan, Ryan P.; Earhart, Gammon M.

    2012-01-01

    Objective To determine the effect of a 12-month community-based tango dance program on activity participation among individuals with Parkinson disease (PD). Design Randomized controlled trial with assessment at baseline, 3, 6, and 12 months. Setting The intervention was administered in the community; assessments were completed in a university laboratory. Participants Sixty-two volunteers with PD enrolled in the study and were randomized to treatment group. Ten participants did not receive the allocated intervention, so the final analyzed sample included 52 participants. Intervention Participants were randomly assigned to the Tango group, which involved 12 months of twice weekly Argentine tango dance classes, or to the no intervention Control group (n = 26 per group). Main Outcome Measures Current, new and retained participation in instrumental, leisure and social activities as measured by the Activity Card Sort (with the “dance” activity removed). Results Total Current participation in the Tango group was higher at 3, 6, and 12 months compared to baseline (ps ≤ 0.008), while the Control group did not change (ps ≥ 0.11). Total Activity Retention (since onset of PD) in the Tango group increased from 77% to 90% (p = 0.006) over the course of the study, whereas the Control group remained around 80% (p = 0.60). These patterns were similar in the separate activity domains. The Tango group gained a significant number of New Social activities (p = 0.003), but the Control group did not (p = 0.71). Conclusions Individuals with PD who participated in a community-based Argentine tango class reported increased participation in complex daily activities, recovery of activities lost since the onset of PD, and engagement in new activities. Incorporating dance into the clinical management of PD may benefit participation and subsequently quality of life for this population. PMID:22902795

  8. Community-based Argentine tango dance program is associated with increased activity participation among individuals with Parkinson's disease.

    PubMed

    Foster, Erin R; Golden, Laura; Duncan, Ryan P; Earhart, Gammon M

    2013-02-01

    To determine the effects of a 12-month community-based tango dance program on activity participation among individuals with Parkinson's disease (PD). Randomized controlled trial with assessment at baseline, 3, 6, and 12 months. Intervention was administered in the community; assessments were completed in a university laboratory. Volunteers with PD (n=62) enrolled in the study and were randomized to a treatment group; 10 participants did not receive the allocated intervention, and therefore the final analyzed sample included 52 participants. Participants were randomly assigned to the tango group, which involved 12 months of twice-weekly Argentine tango dance classes, or to the no intervention control group (n=26 per group). Current, new, and retained participation in instrumental, leisure, and social activities, as measured by the Activity Card Sort (with the dance activity removed). Total current participation in the tango group was higher at 3, 6, and 12 months compared with baseline (Ps≤.008), while the control group did not change (Ps≥.11). Total activity retention (since onset of PD) in the tango group increased from 77% to 90% (P=.006) over the course of the study, whereas the control group remained around 80% (P=.60). These patterns were similar in the separate activity domains. The tango group gained a significant number of new social activities (P=.003), but the control group did not (P=.71). Individuals with PD who participated in a community-based Argentine tango class reported increased participation in complex daily activities, recovery of activities lost since the onset of PD, and engagement in new activities. Incorporating dance into the clinical management of PD may benefit participation and subsequently quality of life for this population. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  9. Structure, composition and metagenomic profile of soil microbiomes associated to agricultural land use and tillage systems in Argentine Pampas.

    PubMed

    Carbonetto, Belén; Rascovan, Nicolás; Álvarez, Roberto; Mentaberry, Alejandro; Vázquez, Martin P

    2014-01-01

    Agriculture is facing a major challenge nowadays: to increase crop production for food and energy while preserving ecosystem functioning and soil quality. Argentine Pampas is one of the main world producers of crops and one of the main adopters of conservation agriculture. Changes in soil chemical and physical properties of Pampas soils due to different tillage systems have been deeply studied. Still, not much evidence has been reported on the effects of agricultural practices on Pampas soil microbiomes. The aim of our study was to investigate the effects of agricultural land use on community structure, composition and metabolic profiles on soil microbiomes of Argentine Pampas. We also compared the effects associated to conventional practices with the effects of no-tillage systems. Our results confirmed the impact on microbiome structure and composition due to agricultural practices. The phyla Verrucomicrobia, Plactomycetes, Actinobacteria, and Chloroflexi were more abundant in non cultivated soils while Gemmatimonadetes, Nitrospirae and WS3 were more abundant in cultivated soils. Effects on metabolic metagenomic profiles were also observed. The relative abundance of genes assigned to transcription, protein modification, nucleotide transport and metabolism, wall and membrane biogenesis and intracellular trafficking and secretion were higher in cultivated fertilized soils than in non cultivated soils. We also observed significant differences in microbiome structure and taxonomic composition between soils under conventional and no-tillage systems. Overall, our results suggest that agronomical land use and the type of tillage system have induced microbiomes to shift their life-history strategies. Microbiomes of cultivated fertilized soils (i.e. higher nutrient amendment) presented tendencies to copiotrophy while microbiomes of non cultivated homogenous soils appeared to have a more oligotrophic life-style. Additionally, we propose that conventional tillage systems may

  10. Structure, Composition and Metagenomic Profile of Soil Microbiomes Associated to Agricultural Land Use and Tillage Systems in Argentine Pampas

    PubMed Central

    Carbonetto, Belén; Rascovan, Nicolás; Álvarez, Roberto; Mentaberry, Alejandro; Vázquez, Martin P.

    2014-01-01

    Agriculture is facing a major challenge nowadays: to increase crop production for food and energy while preserving ecosystem functioning and soil quality. Argentine Pampas is one of the main world producers of crops and one of the main adopters of conservation agriculture. Changes in soil chemical and physical properties of Pampas soils due to different tillage systems have been deeply studied. Still, not much evidence has been reported on the effects of agricultural practices on Pampas soil microbiomes. The aim of our study was to investigate the effects of agricultural land use on community structure, composition and metabolic profiles on soil microbiomes of Argentine Pampas. We also compared the effects associated to conventional practices with the effects of no-tillage systems. Our results confirmed the impact on microbiome structure and composition due to agricultural practices. The phyla Verrucomicrobia, Plactomycetes, Actinobacteria, and Chloroflexi were more abundant in non cultivated soils while Gemmatimonadetes, Nitrospirae and WS3 were more abundant in cultivated soils. Effects on metabolic metagenomic profiles were also observed. The relative abundance of genes assigned to transcription, protein modification, nucleotide transport and metabolism, wall and membrane biogenesis and intracellular trafficking and secretion were higher in cultivated fertilized soils than in non cultivated soils. We also observed significant differences in microbiome structure and taxonomic composition between soils under conventional and no- tillage systems. Overall, our results suggest that agronomical land use and the type of tillage system have induced microbiomes to shift their life-history strategies. Microbiomes of cultivated fertilized soils (i.e. higher nutrient amendment) presented tendencies to copiotrophy while microbiomes of non cultivated homogenous soils appeared to have a more oligotrophic life-style. Additionally, we propose that conventional tillage systems

  11. Malvinas Current variations: dissipation of mesoscale activity over the Malvinas Plateau and recurrent blocking events in the Argentine Basin.

    NASA Astrophysics Data System (ADS)

    Provost, C.; Artana, C.; Ferrari, R.; Koenig, Z.; Saraceno, M.; Piola, A. R.

    2016-12-01

    The Malvinas Current (MC) is an offshoot of the Antarctic Circumpolar Current (ACC). Downstream of Drake Passage, the northern fronts of the ACC veer northward, cross over the North Scotia Ridge (NSR) and the Malvinas Plateau and enter the Argentine Basin. We investigate the variations of the MC circulation between the NSR and 41°S and their possible relations with the ACC circulation using data from Argo floats and satellite altimetry. The data depict meandering and eddy-shedding of the northern ACC jets as they cross the NSR. The satellite fields (altimetry and high resolution sea surface temperature images) show that these eddies are trapped, break down and dissipate over the Malvinas Plateau, suggesting that this region is a hot spot for dissipation of mesoscale variability. Variations of sea level anomalies (SLA) across the NSR do not impact the MC further north, except for intra-seasonal variability associated with coastal trapped waves. Altimetry and float trajectories show events during which a large fraction of the MC is cut off from the ACC. During these blocking events, the MC does not collapse as a robust cyclonic cell is established to the north of the cut-off. The MC becomes the western boundary current of the cell and small cyclonic eddies locally reinforce the circulation. Blocking events at around 48.5°S are a recurrent feature of the MC circulation. Over the 23 year altimetry record, we detected 26 events during which the MC surface transport at 48.5°S was reduced to less than half its long term mean. Blocking events last from 10 to 35 days and do not present any significant trend. These events were tracked back to positive SLA that built up over the Argentine Abyssal Plain.

  12. Population genetics and colony structure of the Argentine ant (Linepithema humile) in its native and introduced ranges.

    PubMed

    Tsutsui, N D; Case, T J

    2001-05-01

    Introduced species often possess low levels of genetic diversity relative to source populations as a consequence of the small population sizes associated with founder events. Additionally, native and introduced populations of the same species can possess divergent genetic structuring at both large and small geographic scales. Thus, genetic systems that have evolved in the context of high diversity may function quite differently in genetically homogeneous introduced populations. Here we conduct a genetic analysis of native and introduced populations of the Argentine ant (Linepithema humile) in which we show that the population-level changes that have occurred during introduction have produced marked changes in the social structure of this species. Native populations of the Argentine ant are characterized by a pattern of genetic isolation by distance, whereas this pattern is absent in introduced populations. These differences appear to arise both from the effects of recent range expansion in the introduced range as well as from differences in gene flow within each range. Relatedness within nests and colonies is lower in the introduced range than in the native range as a consequence of the widespread genetic similarity that typifies introduced populations. In contrast, nestmates and colony-mates in the native range are more closely related, and local genetic differentiation is evident. Our results shed light on the problem posed for kin selection theory by the low levels of relatedness that are characteristic of many unicolonial species and suggest that the loss of genetic variation may be a common mechanism for the transition to a unicolonial colony structure.

  13. Impact of selenium on mortality, bioaccumulation and feeding deterrence in the invasive Argentine ant, Linepithema humile (Hymenoptera: Formicidae).

    PubMed

    De La Riva, Deborah G; Vindiola, Beatriz G; Castañeda, Tracy N; Parker, David R; Trumble, John T

    2014-05-15

    Ants are known for the important roles they play in processes contributing to ecosystem functioning in many habitats. However, pollutants can impact the ecosystem services provided by ants. The Argentine ant, an invasive species in North America, was investigated for the potential impact selenium (Se) may have on ants residing within a contaminated habitat. Mortality tests were conducted using worker ants fed an artificial nectar source containing 1-of-4 environmentally common Se compounds (forms): seleno-l-methionine, methylselenocysteine, selenate or selenite. Accumulation of Se in ant bodies at the end of two weeks was quantified with the use of hydride generation atomic absorption spectroscopy. Lastly, we conducted choice tests using dyes to determine whether ants might avoid a carbohydrate diet containing Se by providing them a choice between sucrose with or without Se. Choice tests also tested the responses of ants to selenium when provided in different background sucrose concentrations. The results of this study indicated that form and quantity of Se, as well as time of exposure, impact mortality in Argentine ant workers. Methylselenocysteine and selenate were found to be the most toxic among the 4 chemical forms when presented in sucrose solutions, whereas seleno-l-methionine and selenite caused greater Se body burdens. Furthermore, choice tests showed that ants did not prefer control sucrose solution to sucrose treated with Se regardless of the background sucrose concentration. These findings serve as first look into the possible detrimental impacts these contaminants may pose for ants that frequent sugary nectar sources. Copyright © 2014. Published by Elsevier B.V.

  14. Integrating physiology, population dynamics and climate to make multi-scale predictions for the spread of an invasive insect: the Argentine ant at Haleakala National Park, Hawaii

    USGS Publications Warehouse

    Hartley, Stephen; Krushelnycky, Paul D.; Lester, Philip J.

    2010-01-01

    Mechanistic models for predicting species’ distribution patterns present particular advantages and challenges relative to models developed from statistical correlations between distribution and climate. They can be especially useful for predicting the range of invasive species whose distribution has not yet reached equilibrium. Here, we illustrate how a physiological model of development for the invasive Argentine ant can be connected to differences in micro-site suitability, population dynamics and climatic gradients; processes operating at quite different spatial scales. Our study is located in the subalpine shrubland of Haleakala National Park, Hawaii, where the spread of Argentine ants Linepithema humile has been documented for the past twenty-five years. We report four main results. First, at a microsite level, the accumulation of degree-days recorded in potential ant nest sites under bare ground or rocks was significantly greater than under a groundcover of grassy vegetation. Second, annual degree-days measured where population boundaries have not expanded (456-521 degree-days), were just above the developmental requirements identified from earlier laboratory studies (445 degree-days above 15.98C). Third, rates of population expansion showed a strong linear relationship with annual degree-days. Finally, an empirical relationship between soil degree-days and climate variables mapped at a broader scale predicts the potential for future range expansion of Argentine ants at Haleakala, particularly to the west of the lower colony and the east of the upper colony. Variation in the availability of suitable microsites, driven by changes in vegetation cover and ultimately climate, provide a hierarchical understanding of the distribution of Argentine ants close to their cold-wet limit of climatic tolerances. We conclude that the integration of physiology, population dynamics and climate mapping holds much promise for making more robust predictions about

  15. Acoustic Resonance Classification of Swimbladder-Bearing Fish at Multiple Scales

    DTIC Science & Technology

    2011-09-30

    Clupea harengus ). Red: Acadian redfish (Sebastes fasciatus). 12 Franklin Swell 2011: Individual fish at 1-6 kHz...trawl hauls. Trawls were conducted on an ad hoc basis, when aggregations of fish were observed in the echo-sounder data. Atlantic herring ( Clupea ... harengus ), Acadian redfish (Sebastes fasciatus), and silver hake (Merluccius bilinearis) comprised the majority of the trawl catches. Other finfish and

  16. Trophic ecology of the invasive argentine ant: spatio-temporal variation in resource assimilation and isotopic enrichment

    PubMed Central

    Suarez, Andy V.; Tillberg, Chadwick V.; Chou, Cheng T.; Holway, David A.

    2010-01-01

    Studies of food webs often employ stable isotopic approaches to infer trophic position and interaction strength without consideration of spatio-temporal variation in resource assimilation by constituent species. Using results from laboratory diet manipulations and monthly sampling of field populations, we illustrate how nitrogen isotopes may be used to quantify spatio-temporal variation in resource assimilation in ants. First, we determined nitrogen enrichment using a controlled laboratory experiment with the invasive Argentine ant (Linepithema humile). After 12 weeks, worker δ15N values from colonies fed an animal-based diet had δ15N values that were 5.51% greater compared to colonies fed a plant-based diet. The shift in δ15N values in response to the experimental diet occurred within 10 weeks. We next reared Argentine ant colonies with or without access to honeydew-producing aphids and found that after 8 weeks workers from colonies without access to aphids had δ15N values that were 6.31% larger compared to colonies with access to honeydew. Second, we sampled field populations over a 1-year period to quantify spatio-temporal variability in isotopic ratios of L. humile and those of a common native ant (Solenopsis xyloni). Samples from free-living colonies revealed that fluctuations in δ15N were 1.6–2.4‰ for L. humile and 1.8–2.9‰ for S. xyloni. Variation was also detected among L. humile castes: time averaged means of δ15N varied from 1.2 to 2.5‰ depending on the site, with δ15N values for queens ≥ workers > brood. The estimated trophic positions of L. humile and S. xyloni were similar within a site; however, trophic position for each species differed significantly at larger spatial scales. While stable isotopes are clearly useful for examining the trophic ecology of arthropod communities, our results suggest that caution is warranted when making ecological interpretations when stable isotope collections come from single time periods or

  17. Trophic ecology of the invasive argentine ant: spatio-temporal variation in resource assimilation and isotopic enrichment.

    PubMed

    Menke, Sean B; Suarez, Andy V; Tillberg, Chadwick V; Chou, Cheng T; Holway, David A

    2010-11-01

    Studies of food webs often employ stable isotopic approaches to infer trophic position and interaction strength without consideration of spatio-temporal variation in resource assimilation by constituent species. Using results from laboratory diet manipulations and monthly sampling of field populations, we illustrate how nitrogen isotopes may be used to quantify spatio-temporal variation in resource assimilation in ants. First, we determined nitrogen enrichment using a controlled laboratory experiment with the invasive Argentine ant (Linepithema humile). After 12 weeks, worker δ(15)N values from colonies fed an animal-based diet had δ(15)N values that were 5.51% greater compared to colonies fed a plant-based diet. The shift in δ(15)N values in response to the experimental diet occurred within 10 weeks. We next reared Argentine ant colonies with or without access to honeydew-producing aphids and found that after 8 weeks workers from colonies without access to aphids had δ(15)N values that were 6.31% larger compared to colonies with access to honeydew. Second, we sampled field populations over a 1-year period to quantify spatio-temporal variability in isotopic ratios of L. humile and those of a common native ant (Solenopsis xyloni). Samples from free-living colonies revealed that fluctuations in δ(15)N were 1.6-2.4‰ for L. humile and 1.8-2.9‰ for S. xyloni. Variation was also detected among L. humile castes: time averaged means of δ(15)N varied from 1.2 to 2.5‰ depending on the site, with δ(15)N values for queens ≥ workers > brood. The estimated trophic positions of L. humile and S. xyloni were similar within a site; however, trophic position for each species differed significantly at larger spatial scales. While stable isotopes are clearly useful for examining the trophic ecology of arthropod communities, our results suggest that caution is warranted when making ecological interpretations when stable isotope collections come from single time periods or

  18. Reconciling tectonic shortening, sedimentation and spatial patterns of erosion from 10Be paleo-erosion rates in the Argentine Precordillera

    NASA Astrophysics Data System (ADS)

    Val, Pedro; Hoke, Gregory D.; Fosdick, Julie C.; Wittmann, Hella

    2016-09-01

    The temporal evolution of erosion over million-year timescales is key to understand the development of mountain ranges and adjacent fold-and-thrust belts. While models of orogenic wedge dynamics predict an instantaneous response of erosion to pulses of rock uplift, stream-power based models predict that catchment-wide erosion maxima significantly lag behind a pulse of rock uplift. Here, we explore the relationships between rock uplift, erosion, and sediment deposition in the Argentine Precordillera fold-and-thrust belt at 30°S. Using a combination of 10Be-derived paleo-erosion rates, constraints on re-exposure using 26Al/10Be ratios, geomorphic observations and detrital zircon provenance, we demonstrate that the attainment of maximum upland erosion rates lags the maximum rate of deformation over million-year timescales. The magnitudes and causes of the erosional delays shed new light on the catchment erosional response to tectonic deformation and rock uplift in orogenic wedges.

  19. A longitudinal study of hantavirus infection in three sympatric reservoir species in agroecosystems on the Argentine Pampa.

    PubMed

    Mills, James N; Schmidt, Karina; Ellis, Barbara A; Calderón, Gladys; Enría, Delia A; Ksiazek, Thomas G

    2007-01-01

    Prevalence of antibody reactive with Sin Nombre hantavirus (SNV) was evaluated from rodents captured over 31 months (March 1988 to September 1990) from six mark-recapture grids on the central Argentine Pampa. The most frequently infected rodents were: Akodon azarae (31/459), Necromys benefactus (8/141), and Oligoryzomys flavescens (10/281), which are known hosts of Pergamino, Maciel, and Lechiguanas hantaviruses, respectively. Relative population density and antibody prevalence varied seasonally and from year to year, population densities were highest in fall and prevalences were highest in spring. A positive association between antibody prevalence and body weight corroborated findings from other studies suggesting that hantaviruses are maintained in reservoir populations by horizontal transmission. In two of three host species, transmission was more frequent among male than among female mice. We found no evidence for a detrimental effect of hantavirus infection on host body weight, growth, longevity, movement, or reproductive preparedness. This analysis, based on cryopreserved specimens, represents the earliest conducted longitudinal, mark-recapture study of the dynamics of infection of autochthonous American hantaviruses in their sigmodontine host populations.

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

    PubMed

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

    2014-11-01

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

  1. Modelling American trypanosomiasis in an endemic zone: application to the initial spread of household infection in the Argentine Chaco.

    PubMed

    Fabrizio, M C; Schweigmann, N J; Bartoloni, N J

    2014-12-01

    The complex dynamics of Trypanosoma cruzi infection (Chagas disease) involves different actors and multiple transmission routes. Based on the information currently available, here, we propose a new and more comprehensive model to better understand the dynamics of the infection. This mathematical deterministic model was formulated considering: (i) the three clinical forms in humans: acute, chronic indeterminate and chronic with determinate pathology, (ii) the three main modes of transmission in the human population: vector-borne, congenital and transfusional, (iii) populations of triatomines and dogs as the main domestic reservoirs of T. cruzi and (iv) open populations. A numerical simulation was also performed to estimate the initial spread of the infection in a typical rural household in the endemic zone of the Argentine Gran Chaco. We also analysed the incidence of infected individuals corresponding to each of the three species (humans/triatomines/dogs) over times until the appearance of the first case in the other species. The model predicts that, in the absence of control measures, a few infected individuals are sufficient for the establishment and dispersion of the infection in all the inhabitants of the household. The model proposed and the results obtained allow describing the consequences of the presence of infected individuals in any of the three species considered in the dynamics and the output of the infection.

  2. The Usefulness of Edible and Medicinal Fabaceae in Argentine and Chilean Patagonia: Environmental Availability and Other Sources of Supply

    PubMed Central

    Molares, Soledad; Ladio, Ana

    2012-01-01

    Fabaceae is of great ethnobotanical importance in indigenous and urban communities throughout the world. This work presents a revision of the use of Fabaceae as a food and/or medicinal resource in Argentine-Chilean Patagonia. It is based on a bibliographical analysis of 27 ethnobotanical sources and catalogues of regional flora. Approximately 234 wild species grow in Patagonia, mainly (60%) in arid environments, whilst the remainder belong to Sub-Antarctic forest. It was found that 12.8% (30 species), mainly woody, conspicuous plants, are collected for food or medicines. Most of the species used grow in arid environments. Cultivation and purchase/barter enrich the Fabaceae offer, bringing it up to a total of 63 species. The richness of native and exotic species, and the existence of multiple strategies for obtaining these plants, indicates hybridization of knowledge and practices. Only 22% of the total species used are mentioned in bothcontexts of food and medicine, reflecting low-use complementation. This study suggests a significant ecological appearance and a high level of availability in shops and exchange networks in Patagonia, highlighting the need to consider the full set of environmental and socioeconomic factors in research related to the use and cultural importance of plants in regional contexts. PMID:22194774

  3. Evolution of the northern Argentine margin during the Cenozoic controlled by bottom current dynamics and gravitational processes

    NASA Astrophysics Data System (ADS)

    Gruetzner, J.; Uenzelmann-Neben, G.; Franke, D.

    2016-08-01

    A detailed reflection seismic investigation on sediment deposition at the northern Argentine margin (37°S-42°S) resolves major modifications in oceanographic circulation during the Cenozoic, which resulted from variations in both climatic and tectonic processes. After an extensive erosional period following the onset of glaciation of Antartica at ˜34 Ma, which affected all water depth levels, a buried elongated mounded drift within the continental shelf was shaped by bottom current activity during the Miocene. This may represent the earliest deposits of the Malvinas Current that branches from the Antartic Circumpolar Current and today is part of a complex shallow water circulation system known as the Brazil-Malvinas confluence. At the same time, a major terrace grew to its present form on the upper slope indicating that a precursor of Antarctic Intermediate Water was also part of the Brazil-Malvinas confluence. After another major erosional phase inferred from a seismic unconformity at ˜6 Ma, sheeted drifts, mounded drifts, and sediment waves formed at the continental rise during the Pliocene/Pleistocene. These extensive contourite deposits are diagnostic for a steady north setting bottom flow at the depth level of today's Antarctic Bottom Water. Evidence for downslope transport mainly stems from the presence of buried turbidites and canyon-related depocenters. These features can be related to Andean uplift during the Eocene and to the activation of the canyon system during the Pliocene.

  4. Relationship between beak morphological variables and body size and mantle length of male and female Argentine shortfin squid ( Illex argentinus)

    NASA Astrophysics Data System (ADS)

    Chen, Xinjun; Lu, Huajie; Liu, Bilin; Fang, Zhou

    2012-12-01

    Beak of cephalopod is an important hard tissue. Understanding the morphology of beak can yield critical information on the role of cephalopods in the ecosystem. The south patagonic stock of the Argentine shortfin squid, Illex argentinus, is not only one of the most important fishing targets, but also one of the most important species in the marine eco-system of the southwest Atlantic. A total of 430 samples of I. argentinus, including 229 females 103-346mm in mantle length (ML) and 201 males 140-298mm in ML, were collected from the area off the Exclusive Economic Zone of Argentinean waters by Chinese squid jigging vessels during February to May 2007. The morphology of their beaks was evaluated. The relationships between beak morphological variables and ML differed significantly among males and females. They could be best described by logarithmic functions for females and linear functions for males except for upper wing length (UWL) and lower rostrum length (LRL), which followed exponential functions in their relationships with ML. The results showed the sexual dimorphism in the relationship between ML and beak morphology for the south patagonic stock of I. argentinus. However, no significant difference was found between males and females in the relationships of beak morphological variables (except for UWL) versus body weight (BW), suggesting that the relationship between beak morphological variables and BW can be used for estimating the biomass consumed by their predators.

  5. Microgeographic Spatial Structuring of Triatoma infestans (Hemiptera: Reduviidae) Populations Using Wing Geometric Morphometry in the Argentine Chaco

    PubMed Central

    GASPE, M. S.; SCHACHTER-BROIDE, J.; GUREVITZ, J. M.; KITRON, U.; GÜRTLER, R. E.; DUJARDIN, J. P.

    2013-01-01

    We investigated the occurrence of spatial structuring in Triatoma infestans (Klug) (Hemiptera: Reduviidae) populations 12 yr after the last community-wide insecticide spraying campaign in rural Pampa del Indio, in the Gran Chaco of northeastern Argentina. In total, 172 male and 149 female right wings collected at 16 georeferenced sites with at least 10 individuals of the same sex were analyzed using geometric morphometry. Mean female body length and wing centroid size (CS) were significantly larger than for males. Log-transformed CS and length were significantly and positively correlated both for males and females. Males collected in domiciles had significantly smaller CS than those collected in peridomestic structures both closed (kitchens or storerooms) or open (chicken coops), in agreement with our previous results elsewhere in the dry Argentine Chaco. Female wing CS was not significantly different between ecotopes. Wing shape analyses showed the occurrence of significant geographic structuring in males and females combined and in males only. Male wings showed a strong association between Mahalanobis distance and geographic distance. In general, Mahalanobis distances were significantly different between collection sites located >4 km apart. For collection sites located <4 km apart, the greater the geographic distance the larger the difference in wing shape variables. Among females, only a partial correspondence between geographic groups and Mahalanobis distances was recorded. The strong spatial structuring found in T. infestans populations may be useful for the identification of putative reinfestation sources after vector control interventions. PMID:22679857

  6. Strength in numbers: large and permanent colonies have higher queen oviposition rates in the invasive Argentine ant (Linepithema humile, Mayr).

    PubMed

    Abril, Sílvia; Gómez, Crisanto

    2014-03-01

    Polydomy associated with unicoloniality is a common trait of invasive species. In the invasive Argentine ant, colonies are seasonally polydomous. Most follow a seasonal fission-fussion pattern: they disperse in the spring and summer and aggregate in the fall and winter. However, a small proportion of colonies do not migrate; instead, they inhabit permanent nesting sites. These colonies are large and highly polydomous. The aim of this study was to (1) search for differences in the fecundity of queens between mother colonies (large and permanent) and satellite colonies (small and temporal), (2) determine if queens in mother and satellite colonies have different diets to clarify if colony size influences social organization and queen feeding, and (3) examine if colony location relative to the invasion front results in differences in the queen's diet. Our results indicate that queens from mother nests are more fertile than queens from satellite nests and that colony location does not affect queen oviposition rate. Ovarian dissections suggest that differences in ovarian morphology are not responsible for the higher queen oviposition rate in mother vs. satellite nests, since there were no differences in the number and length of ovarioles in queens from the two types of colonies. In contrast, the higher δ(15)N values of queens from mother nests imply that greater carnivorous source intake accounts for the higher oviposition rates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Invasive Argentine ants (Linepithema humile) do not replace native ants as seed dispersers of Dendromecon rigida (Papaveraceae) in California, USA.

    PubMed

    Carney, Shanna E; Byerley, M Brooke; Holway, David A

    2003-05-01

    We investigated the indirect effects of Argentine ant (Linepithema humile) invasions on patterns of seed dispersal and predation in the myrmecochorous tree poppy Dendromecon rigida in coastal San Diego County, California. Significantly more seeds were removed from ant-accessible seed stations at sites numerically dominated by a common harvester ant (Pogonomyrmex subnitidus), a native disperser of these seeds and a species sensitive to displacement by L. humile, than from those stations at sites where L. humile was in the majority. Predation of seeds was high, but variable, across sites, suggesting that reduced dispersal could result in increased seed predation in some habitats. Removal of elaiosomes did not affect the frequency with which predators removed seeds, but ants removed significantly more seeds with elaiosomes than without. In behavior trials, only P. subnitidus was able to carry seeds of Dendromecon rigida effectively. L. humile and a small native ant species, Dorymyrmex insanus, while displaying interest in the diaspores, were seldom able to carry whole seeds and, when they did, only carried them a few centimeters. Displacement of native harvester ants by L. humile appears to decrease the dispersal of Dendromecon rigida seeds and may be increasing loss of seeds due to predation.

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

    PubMed Central

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

    2014-01-01

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

  9. Variation in the level of aggression, chemical and genetic distance among three supercolonies of the Argentine ant in Europe.

    PubMed

    Blight, O; Berville, L; Vogel, V; Hefetz, A; Renucci, M; Orgeas, J; Provost, E; Keller, L

    2012-08-01

    In their invasive ranges, Argentine ant populations often form one geographically vast supercolony, genetically and chemically uniform within which there is no intraspecific aggression. Here we present regional patterns of intraspecific aggression, cuticular hydrocarbons (CHCs) and population genetics of 18 nesting sites across Corsica and the French mainland. Aggression tests confirm the presence of a third European supercolony, the Corsican supercolony, which exhibits moderate to high levels of aggression, depending on nesting sites, with the Main supercolony, and invariably high levels of aggression with the Catalonian supercolony. The chemical analyses corroborated the behavioural data, with workers of the Corsican supercolony showing moderate differences in CHCs compared to workers of the European Main supercolony and strong differences compared to workers of the Catalonian supercolony. Interestingly, there were also clear genetic differences between workers of the Catalonian supercolony and the two other supercolonies at both nuclear and mitochondrial markers, but only very weak genetic differentiation between nesting sites of the Corsican and Main supercolonies (F(ST) = 0.06). A detailed comparison of the genetic composition of supercolonies also revealed that, if one of the last two supercolonies derived from the other, it is the Main supercolony that derived from the Corsican supercolony rather than the reverse. Overall, these findings highlight the importance of conducting more qualitative and quantitative analyses of the level of aggression between supercolonies, which has to be correlated with genetic and chemical data. © 2012 Blackwell Publishing Ltd.

  10. The Major Determinant of Attenuation in Mice of the Candid1 Vaccine for Argentine Hemorrhagic Fever Is Located in the G2 Glycoprotein Transmembrane Domain▿

    PubMed Central

    Albariño, César G.; Bird, Brian H.; Chakrabarti, Ayan K.; Dodd, Kimberly A.; Flint, Mike; Bergeron, Éric; White, David M.; Nichol, Stuart T.

    2011-01-01

    Candid1, a live-attenuated Junin virus vaccine strain, was developed during the early 1980s to control Argentine hemorrhagic fever, a severe and frequently fatal human disease. Six amino acid substitutions were found to be unique to this vaccine strain, and their role in virulence attenuation in mice was analyzed using a series of recombinant viruses. Our results indicate that Candid1 is attenuated in mice through a single amino acid substitution in the transmembrane domain of the G2 glycoprotein. This work provides insight into the molecular mechanisms of attenuation of the only arenavirus vaccine currently available. PMID:21795336

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  12. On deep-current and hydrographic observations from a mudwave region and elsewhere in the Argentine Basin

    NASA Astrophysics Data System (ADS)

    Weatherly, Georges L.

    Near-bottom current measurements from both sides of a mudwave, in an extensive mudwave region of the mid-Argentine Basin, are examined for evidence of lee waves. Such waves appear to exist when the across-crest flow exceeds a critical value [predicted by FLOOD (1988), Deep-Sea Research, 35, 973-983] of about 9 cm s -1. The observations agree with the predictions of BLUMSACK and WEATHERLY (1989, Deep-Sea Research, 36, 155-172) in three of four cases. However, if it is assumed that the flow perturbations induced by lee waves are shifted slightly downcurrent from that predicted by the Blumsack and Weatherly model, then there is agreement in all four cases. The mudwave region is characterized as having a strong (˜ 10 cm s -1), steady (eddy kinetic energy < mean kinetic energy) current. The westward flow is consistent with the anticyclonic abyssal gyre centered about the Zapiola Drift inferred by FLOOD and SHOR (1987, Deep-Sea Research, 35, 973-983). Near-bottom flow measurements made further to the west, in the region of confluence of the Brazil and Malvinas Current Extensions, reveal relatively energetic fluctuations, and equatorward flowing deep western boundary currents along the continental slope. Along the continental rise a poleward flow is observed, consistent with that inferred by REID (1989, Progress in Oceanography, 23, 149-244). Too-cold bottom layers were found to be common only on the lower continental slope (4000 m depth) and at the mid-basin, mudwave site.

  13. Skeletal involvement in Gaucher disease: An observational multicenter study of prognostic factors in the Argentine Gaucher disease patients.

    PubMed

    Drelichman, Guillermo; Fernández Escobar, Nicolás; Basack, Nora; Aversa, Luis; Larroude, María Silvia; Aguilar, Gabriela; Szlago, Marina; Schenone, Andrea; Fynn, Alcyra; Cuello, María Fernanda; Aznar, Marcela; Fernández, Ramiro; Ruiz, Alba; Reichel, Paola; Guelbert, Norberto; Robledo, Hugo; Watman, Nora; Bolesina, Moira; Elena, Graciela; Veber, S Ernesto; Pujal, Graciela; Galván, Graciela; Chain, Juan José; Arizo, Adriana; Bietti, Julieta; Bar, Daniel; Dragosky, Marta; Marquez, Marisa; Feldman, Leonardo; Muller, Katja; Zirone, Sandra; Buchovsky, Greogorio; Lanza, Victoria; Sanabria, Alba; Fernández, Ignacio; Jaureguiberry, Rossana; Contte, Marcelo; Barbieri María, Angie; Maro, Alejandra; Zárate, Graciela; Fernández, Gabriel; Rapetti, María Cristina; Donato, Hugo; Degano, Adriana; Kantor, Gustavo; Albina, Roberto; Á Lvarez Bollea, María; Brun, María; Bacciedoni, Viviana; Del Río, Francis; Soberón, Bárbara; Boido, Nazario; Schweri, Maya; Borchichi, Sandra; Welsh, Victoria; Corrales, Marcela; Cedola, Alejandra; Carvani, Analía; Diez, Blanca; Richard, Lucía; Baduel, Ccecilia; Nuñez, Gabriela; Colimodio, Rubén; Barazzutti, Lucía; Medici, Hugo; Meschengieser, Susana; Damiani, Germán; Nucifora, María; Girardi, Beatriz; Gómez, Sergio; Papucci, Maura; Verón, David; Quiroga, Luis; Carro, Gustavo; De Ambrosio, Patricia; Ferro, José; Pujol, Marcelo; Castella, Cristina Cabral; Franco, Liliana; Nisnovich, Gisela; Veloso, María; Pacheco, Isabel; Savarino, Mario; Marino, Andrés; Saavedra, José Luis

    2016-10-01

    Patients with Gaucher type 1 (GD1) throughout Argentina were enrolled in the Argentine bone project to evaluate bone disease and its determinants. We focused on presence and predictors of bone lesions (BL) and their relationship to therapeutic goals (TG) with timing and dose of enzyme replacement therapy (ERT). A total of 124 patients on ERT were enrolled in a multi-center study. All six TG were achieved by 82% of patients: 70.1% for bone pain and 91.1% for bone crisis. However, despite the fact that bone TGs were achieved, residual bone disease was present in 108 patients on ERT (87%) at time 0. 16% of patients showed new irreversible BL (bone infarcts and avascular osteonecrosis) despite ERT, suggesting that they appeared during ERT or were not detected at the moment of diagnosis. We observed 5 prognostic factors that predicted a higher probability of being free of bone disease: optimal ERT compliance; early diagnosis; timely initiation of therapy; ERT initiation dose ≥45 UI/kg/EOW; and the absence of history of splenectomy. Skeletal involvement was classified into 4 major phenotypic groups according to BL: group 1 (12.9%) without BL; group 2 (28.2%) with reversible BL; group 3 (41.9%) with reversible BL and irreversible chronic BL; and group 4 (16.9%) with acute irreversible BL. Our study identifies prognostic factors for achieving best therapeutic outcomes, introduces new risk stratification for patients and suggests the need for a redefinition of bone TG. Am. J. Hematol. 91:E448-E453, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Analytical methodology optimization to estimate the content of non-flavonoid phenolic compounds in Argentine propolis extracts.

    PubMed

    Isla, María Inés; Salas, Ana; Danert, Fatima C; Zampini, Iris Catiana; Ordoñez, Roxana Mabel

    2014-07-01

    Traditionally, the content of total phenolics (flavonoid phenolics (FP) and non-flavonoid phenolics (NFP)) and flavonoids (flavone/flavonol and flavonone/dihydroflavonol) in propolis has been determined by different methodologies. Until now, the percentage of total phenolic (TP) compounds that corresponds to FP and NFP, expressed in the same units by a spectrophotometric method, has not been determined. The current study proposes a quick and simple methodology that separates FP and NFP in propolis samples and determines TP, FP, and NFP by the same method. Propolis samples from five Argentine provinces (Tucumán, Santiago del Estero, Salta, Misiones, and Jujuy) were used. Extraction of TP from the propolis samples was carried out by maceration with 80% ethanol and quantified by Folin-Ciocalteu reagent (FC-R). Then, FP was precipitated with formaldehyde in acid medium. After centrifugation, NFP were determined in the supernatant using FC-R. FP content was calculated as the difference between the content of TP and NFP. The method was also validated using commercial flavonoids and chalcones. FP recovery in all experiments was between 85.95% and 98.29%. Propolis from Tucumán had significantly higher amounts of total phenols than propolis from other provinces. SE5 showed higher content of FP (81.52%) followed by SA1 (74.75%). The propolis from TUC4, SA4, SE3, and MI showed the lowest FP content and highest content of NFP. This method provides a simple, reliable, and specific spectrophotometric assay to estimate the content of NFP, FP, and TP in propolis samples.

  15. Efficacy of Maxforce bait for control of the Argentine ant (Hymenoptera: Formicidae) in Haleakala National Park, Maui, Hawaii

    USGS Publications Warehouse

    Krushelnycky, Paul D.; Reimer, Neil J.

    1998-01-01

    In an effort to develop a chemical control strategy for the invasive Argentine ant, Linepithema humile (Mayr), in Haleakala National Park, Maxforce, which is formulated with 0.9% hydramethylnon, was used in test plots to determine the efficacy of the ant bait in the field. Initially, Maxforce was tested at 2 application rates: broadcast at 2.25 kg/ha (2 lb/acre) and 4.5 kg/ha (4 lb/acre). Later, the following treatments were also tested: a Maxforce and honey granule mix, Maxforce with 0.5% hydramethylnon, Maxforce with a different solvent, Maxforce distributed in exposed piles, and Maxforce distributed in covered piles. Although there were significant differences in the magnitude of ant reduction among the various treatments, all yielded the same general result. Foraging ant numbers at monitoring bait stations declined an average maximum of 97.0% in the test plots, with no plots achieving 100% reduction. At 2 mo after treatment the mean number of foraging ants was reduced by 92.1%. Nest survival in the plots appeared to be affected to a lesser degree, but could not be monitored accurately over the longer term because of the phenomenon of nest movement. A 2nd identical application 1 mo after the initial application in plots treated with Maxforce at 2.25 and 4.5 kg/ha did not result in eradication. Bait molding, quick mortality, and toxicant breakdown from UV radiation created a short exposure time to the bait and toxicant, which may have been the main obstacle to achieving eradication.

  16. Selection and characterization of Argentine isolates of Trichoderma harzianum for effective biocontrol of Septoria leaf blotch of wheat.

    PubMed

    Stocco, Marina C; Mónaco, Cecilia I; Abramoff, Cecilia; Lampugnani, Gladys; Salerno, Graciela; Kripelz, Natalia; Cordo, Cristina A; Consolo, Verónica F

    2016-03-01

    Species of the genus Trichoderma are economically important as biocontrol agents, serving as a potential alternative to chemical control. The applicability of Trichoderma isolates to different ecozones will depend on the behavior of the strains selected from each zone. The present study was undertaken to isolate biocontrol populations of Trichoderma spp. from the Argentine wheat regions and to select and characterize the best strains of Trichoderma harzianum by means of molecular techniques. A total of 84 out of the 240 strains of Trichoderma were able to reduce the disease severity of the leaf blotch of wheat. Thirty-seven strains were selected for the reduction equal to or greater than 50% of the severity, compared with the control. The percentage values of reduction of the pycnidial coverage ranged between 45 and 80%. The same last strains were confirmed as T. harzianum by polymerase chain reaction amplification of internal transcribed spacers, followed by sequencing. Inter-simple sequence repeat was used to examine the genetic variability among isolates. This resulted in a total of 132 bands. Further numerical analysis revealed 19 haplotypes, grouped in three clusters (I, II, III). Shared strains, with different geographical origins and isolated in different years, were observed within each cluster. The origin of the isolates and the genetic group were partially related. All isolates from Paraná were in cluster I, all isolates from Lobería were in cluster II, and all isolates from Pergamino and Santa Fe were in cluster III. Our results suggest that the 37 native strains of T. harzianum are important in biocontrol programs and could be advantageous for the preparation of biopesticides adapted to the agroecological conditions of wheat culture.

  17. Interactive Effects of Large- and Small-Scale Sources of Feral Honey-Bees for Sunflower in the Argentine Pampas

    PubMed Central

    Sáez, Agustín; Sabatino, Malena; Aizen, Marcelo A.

    2012-01-01

    Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated “sierras”, and narrow (3–7 m wide) strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus). We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group) at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0–10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services. PMID:22303477

  18. Influence of weeds on Argentine ant (Hymenoptera: Formicidae) and obscure mealybug (Hemiptera: Pseudococcidae) in a central California vineyard.

    PubMed

    Costello, Michael J; Welch, Mark D

    2014-06-01

    Obscure mealybug is a pest of grapes in the cool climate regions of coastal California, is found on some vineyard weeds, and is tended by the Argentine ant. A study was conducted at a vineyard in Arroyo Grande, CA, to evaluate the impact of weeds on ant activity on grapevines, and the role that ants and weeds have on obscure mealybug infestation in grape clusters. The incidence of the fungus Botrytis cinerea was recorded as well. Treatments were weed exclusion versus the presence of weeds, and ant exclusion versus the presence of ants. Ant activity was evaluated weekly using sugar-based monitoring stations, and mealybug infestation and Botrytis incidence of clusters were evaluated at harvest. Ant exclusion reduced the overall number of ant visits by 82%, and ants increased mealybug infestation of clusters by 53%. Ant activity was 33% higher in the weeds treatment, but there was no impact of weeds on mealybug infestation. We suggest that the higher ant activity recorded in the weeds treatment may have been an artifact of the sugar-based sampling method. Botrytis incidence was three times higher with ants, but did not differ between weeds and weed exclusion treatments. The study supports other research showing a relationship between mealybug infestation and the presence of ants, as well as the lack of impact of floor vegetation on mealybug infestation of grape clusters. It is the first report of a relationship between ants and Botrytis, although it is more likely that the higher Botrytis incidence found here is a result of increased mealybug density than a direct effect by ants.

  19. Effect of latitudinal gradient and impact of logging on genetic diversity of Cedrela lilloi along the Argentine Yungas Rainforest

    PubMed Central

    Inza, Maria V; Zelener, Noga; Fornes, Luis; Gallo, Leonardo A

    2012-01-01

    Cedrela lilloi C. DC. (cedro coya, Meliaceae), an important south American timber species, has been historically overexploited through selective logging in Argentine Yungas Rainforest. Management and conservation programs of the species require knowledge of its genetic variation patterns; however, no information is available. Molecular genetic variability of the species was characterized to identify high-priority populations for conservation and domestication purposes. Fourteen native populations (160 individuals) along a latitudinal gradient and with different logging's intensities were assessed by 293 polymorphic AFLP (amplified fragment length polymorphism) markers. Genetic diversity was low (Ht = 0.135), according to marginal location of the species in Argentina. Most of the diversity was distributed within populations (87%). Northern populations showed significant higher genetic diversity (R2= 0.69) that agreed with latitudinal pattern of distribution of taxonomic diversity in the Yungas. Three clusters were identified by Bayesian analysis in correspondence with northern, central, and southern Yungas. An analysis of molecular variance (AMOVA) revealed significant genetic differences among latitudinal clusters even when logging (ΦRT = 0.07) and unlogging populations (ΦPT = 0.10) were separately analyzed. Loss of genetic diversity with increasing logging intensity was observed between neighboring populations with different disturbance (ΦPT = 0.03–0.10). Bottlenecks in disturbed populations are suggested as the main cause. Our results emphasize both: the necessity of maintaining the genetic diversity in protected areas that appear as possible long-term refuges of the species; and to rescue for the national system of protected areas some high genetic diversity populations that are on private fields. PMID:23170208

  20. Is the Invasive Species Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae) (Argentine Stem Weevil) a Threat to New Zealand Natural Grassland Ecosystems?

    PubMed

    Barratt, Barbara I P; Barton, Diane M; Philip, Bruce A; Ferguson, Colin M; Goldson, Stephen L

    2016-01-01

    Listronotus bonariensis (Argentine stem weevil) is a stem-boring weevil that has become a major pasture pest in New Zealand, and cool climate turf grass in Australia. This species is also frequently found in native tussock grassland in New Zealand. Laboratory and field trials were established to determine the risk posed to both seedlings and established plants of three native grass species compared to what happens with a common host of this species, hybrid ryegrass (L. perenne X L. multiflorum). Adult weevil feeding damage scores were higher on Poa colensoi and Festuca novae-zelandiae than Chionochloa rigida. Oviposition was lower on P. colensoi than hybrid ryegrass, and no eggs were laid on F. novae-zelandiae. In field trials using the same four species established as spaced plants L. bonariensis laid more eggs per tiller in ryegrass in a low altitude pasture site than in ryegrass in a higher altitude site. No eggs were found on the three native grass species at the tussock sites, and only low numbers were found on other grasses at the low altitude pasture site. Despite this, numbers of adult weevils were extracted from the plants in the field trials. These may have comprised survivors of the original weevils added to the plants, together with new generation weevils that had emerged during the experiment. Irrespective, higher numbers were recovered from the tussock site plants than from those from the pasture site. It was concluded that L. bonariensis is likely to have little overall impact, but a greater impact on native grass seedling survival than on established plants.

  1. Is the Invasive Species Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae) (Argentine Stem Weevil) a Threat to New Zealand Natural Grassland Ecosystems?

    PubMed Central

    Barratt, Barbara I. P.; Barton, Diane M.; Philip, Bruce A.; Ferguson, Colin M.; Goldson, Stephen L.

    2016-01-01

    Listronotus bonariensis (Argentine stem weevil) is a stem-boring weevil that has become a major pasture pest in New Zealand, and cool climate turf grass in Australia. This species is also frequently found in native tussock grassland in New Zealand. Laboratory and field trials were established to determine the risk posed to both seedlings and established plants of three native grass species compared to what happens with a common host of this species, hybrid ryegrass (L. perenne X L. multiflorum). Adult weevil feeding damage scores were higher on Poa colensoi and Festuca novae-zelandiae than Chionochloa rigida. Oviposition was lower on P. colensoi than hybrid ryegrass, and no eggs were laid on F. novae-zelandiae. In field trials using the same four species established as spaced plants L. bonariensis laid more eggs per tiller in ryegrass in a low altitude pasture site than in ryegrass in a higher altitude site. No eggs were found on the three native grass species at the tussock sites, and only low numbers were found on other grasses at the low altitude pasture site. Despite this, numbers of adult weevils were extracted from the plants in the field trials. These may have comprised survivors of the original weevils added to the plants, together with new generation weevils that had emerged during the experiment. Irrespective, higher numbers were recovered from the tussock site plants than from those from the pasture site. It was concluded that L. bonariensis is likely to have little overall impact, but a greater impact on native grass seedling survival than on established plants. PMID:27507979

  2. Faulting and erosion in the Argentine Precordillera during changes in subduction regime: Reconciling bedrock cooling and detrital records

    NASA Astrophysics Data System (ADS)

    Fosdick, Julie C.; Carrapa, Barbara; Ortíz, Gustavo

    2015-12-01

    The Argentine Precordillera is an archetypal retroarc fold-and-thrust belt that records tectonics associated with changing subduction regimes. The interactions between exhumation and faulting in the Precordillera were investigated using apatite and zircon (U-Th-Sm)/He and apatite fission track thermochronometry from the Precordillera and adjacent geologic domains. Inverse modeling of thermal histories constrains eastward in-sequence rock cooling associated with deformation and erosion from 18 to 2 Ma across the Central Precordillera tracking thrusting during this time. The youngest AHe ages (5-2 Ma) and highest erosion rates are located in the eastern and western extremities of the Precordillera and indicate that recent denudation is concentrated at its structural boundaries. Moreover, synchronous rapid Pliocene cooling of the Frontal Cordillera, Eastern Precordillera, and Sierra del Valle Fértil was coeval with initiation of basement-involved faulting in the foreland. Detrital zircon U-Pb geochronology from the ca. 16-8.1 Ma Bermejo foreland basin strata suggests fluvial connectivity westward beyond the Frontal Cordillera to the Main Cordillera and Coast Range followed by an important shift in sediment provenance at ca. 10 Ma. At this time, we suggest that a substantial decrease in Permo-Triassic igneous sources in the Frontal Cordillera and concurrent increase in recycled zircons signatures of Paleozoic strata are best explained by uplift and erosion of the Precordillera during widening of the thrust-belt. Bedrock thermochronology and modeling indicate a 2-6 Myr lag time between faulting-related cooling in the hinterland and the detrital record of deformation in the foreland basin, suggesting that for tectonically active semi-arid settings, bedrock cooling may be more sensitive to onset of faulting. We suggest that high erosion rates in the Frontal Cordillera and Eastern Precordillera are associated with increased interplate coupling during shallowing of the

  3. Isolation of Salmonella spp. from yacare caiman (Caiman yacare) and broad-snouted caiman (Caiman latirostris) from the Argentine Chaco.

    PubMed

    Uhart, Marcela; Ferreyra, Hebe; Mattiello, Rosana; Caffer, María Inés; Terragno, Raquel; Schettino, Adriana; Prado, Walter

    2011-04-01

    Presence of Salmonella spp. was evaluated in yacare caiman (Caiman yacare) and broad-snouted caiman (Caiman latirostris) from a ranching facility in the Argentine Chaco. Crocodilian ranching programs are based on captive breeding of wild-harvested eggs and release of excess hatchlings into the wild. Samples for bacterial isolation were collected from 102 captive (35 C. yacare and 67 C. latirostris) and seven free-ranging caiman (four C. yacare and three C. latirositris) between 2001 and 2005 and from three artificially incubated C. yacare wild eggs. Two Salmonella spp. of known zoonotic potential, S. infantis and S. nottingham, were isolated from captive caiman in 2001 and 2002, respectively. This is the first report for S. nottingham in reptiles and of S. infantis in caiman. Salmonella spp. prevalence varied significantly between years, with a 77% prevalence peak in 2002. Although the cause of this increase was not confirmed, we found no correlation with the type of enclosure, caiman species, or body weight. Deteriorated physical condition of caiman hatchlings due to dietary changes in 2002 could have influenced Salmonella spp. shedding. However, external sources such as food, water, or enclosures could not be ruled out. Pathogenic Salmonella spp. present a risk for human infection. Inadvertent introduction of Salmonella spp. or other bacteria into the environment when caiman are released could pose a threat to wild caiman populations. Prophylactic measures to detect and decrease Salmonella spp. presence in caiman ranching facilities are recommended to reduce risk to humans and make caiman-ranching a sound conservation strategy for crocodilian species.

  4. Interactive effects of large- and small-scale sources of feral honey-bees for sunflower in the Argentine Pampas.

    PubMed

    Sáez, Agustín; Sabatino, Malena; Aizen, Marcelo A

    2012-01-01

    Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated "sierras", and narrow (3-7 m wide) strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus). We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group) at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0-10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services.

  5. Activities with Argentina. Spring 1999. A U.S. Department of Energy Cooperative Program with the National Atomic Energy Commission of the Argentine Republic

    SciTech Connect

    1999-06-01

    In 1989, the US Department of Energy (DOE) responded to the need to redirect resources from weapons production to environmental restoration and waste management by establishing the Office of Environmental Management (EM) and delegated to this office the responsibility of cleaning up the US nuclear weapons complex. Now in its eight year, EM`s mission has three central facets: (1) to assess, remediate, and monitor contaminated sites and facilities; (2) to store, treat, and dispose of waste from past and current operations; and (3) to develop and implement innovative technologies for environmental cleanup. To this end, EM has established domestic and international cooperative technology development programs, including one with the Republic of Argentina. Cooperating with Argentine scientific institutes and industries meets US cleanup objectives by: (1) identifying and accessing Argentine EM-related technologies, thereby leveraging investments and providing cost-savings; (2) improving access to technical information, scientific expertise, and technologies applicable to EM needs; and (3) fostering the development of innovative environmental technologies by increasing US private sector opportunities in Argentina in EM-related areas.

  6. [Factors influencing the distribution of nests of the Argentine ant Linepithema humile Mayr (hymenoptera: formicidae), in a foothills ecosystem of the central zone of Chile].

    PubMed

    Ipinza-Regla, J; Castro, L; Eissemann, R; Morales, M A

    2010-01-01

    The purpose of this research was to demonstrate the dependant relationship between the Argentine ant Linepithema humile Mayr, plant coverage, and human settlements. A method was designed in order to sample the presence of the Argentine ant and other ant species that may had influenced L. humile distribution, under different types of vegetation and percentages of plant coverage, taking in consideration the distance from human settlements. Eight sample stations were established. Four of these stations were found on a dwelling home and the other four were found on similar areas, but far from human settlements. Three transects were established from the center of each sampling station (Tt1, shrublike vegetation, Tt2, herblike vegetation and Tt3, no vegetation). Transects were compound by 10 m side quadrants. A negative correlation was found between nest number of L. humile and human settlement distance, therefore nests were not found at distances higher than 80 m, in all studied areas. There was a positive and significant correlation between nest number of L. humile and plant coverage percentage, regardless the type of vegetation found. The same trend was found for other ant species studied in the area. Finally, it was proved that the distribution of L. humile nests is not influenced by other ant species.

  7. Characterizing and predicting species distributions across environments and scales: Argentine ant occurrences in the eye of the beholder

    USGS Publications Warehouse

    Menke, S.B.; Holway, D.A.; Fisher, R.N.; Jetz, W.

    2009-01-01

    Aim: Species distribution models (SDMs) or, more specifically, ecological niche models (ENMs) are a useful and rapidly proliferating tool in ecology and global change biology. ENMs attempt to capture associations between a species and its environment and are often used to draw biological inferences, to predict potential occurrences in unoccupied regions and to forecast future distributions under environmental change. The accuracy of ENMs, however, hinges critically on the quality of occurrence data. ENMs often use haphazardly collected data rather than data collected across the full spectrum of existing environmental conditions. Moreover, it remains unclear how processes affecting ENM predictions operate at different spatial scales. The scale (i.e. grain size) of analysis may be dictated more by the sampling regime than by biologically meaningful processes. The aim of our study is to jointly quantify how issues relating to region and scale affect ENM predictions using an economically important and ecologically damaging invasive species, the Argentine ant (Linepithema humile). Location: California, USA. Methods: We analysed the relationship between sampling sufficiency, regional differences in environmental parameter space and cell size of analysis and resampling environmental layers using two independently collected sets of presence/absence data. Differences in variable importance were determined using model averaging and logistic regression. Model accuracy was measured with area under the curve (AUC) and Cohen's kappa. Results: We first demonstrate that insufficient sampling of environmental parameter space can cause large errors in predicted distributions and biological interpretation. Models performed best when they were parametrized with data that sufficiently sampled environmental parameter space. Second, we show that altering the spatial grain of analysis changes the relative importance of different environmental variables. These changes apparently result

  8. Vestiges of an Ordovician west-vergent thin-skinned Ocloyic thrust belt in the Argentine Precordillera, southern Central Andes

    NASA Astrophysics Data System (ADS)

    Thomas, William A.; Astini, Ricardo A.

    2007-08-01

    Collision of the down-going, Laurentia-derived Argentine Precordillera terrane with the Gondwanan margin drove the Ordovician Ocloyic orogeny, including subduction volcanism, metamorphism, and top-to-west shearing east of the Precordillera. In the Precordillera, above passive-margin carbonates (Lower Ordovician San Juan Limestone and older carbonates), a Middle to Upper Ordovician westward-prograding synorogenic clastic wedge of black shale (Gualcamayo Shale) and coarser clastic sediment (Las Vacas Conglomerate and Trapiche Formation) fills a peripheral foreland basin. New research has identified vestiges of a west-directed thin-skinned Ocloyic foreland thrust belt that has been fragmented by east-directed Andean thrusting. The El Corral thrust sheet, with hanging-wall detachment in the San Juan Limestone, extends over a west-directed footwall frontal ramp and extensive flat to low-angle footwall cutoff in the Gualcamayo and Las Vacas formations. Las Vacas conglomerates in the footwall include olistoliths (10-m scale) exclusively of San Juan Limestone and Gualcamayo Shale; the beds in some olistoliths are folded. The advancing El Corral thrust sheet successively supplied and overrode the stratigraphically restricted olistoliths. In the El Corral footwall, tight west-vergent folds and faults within an anticlinorium in the San Juan Limestone and Gualcamayo Shale suggest a deeper (unexposed) thrust fault, the Los Celestitos fault. West of the anticlinorium, easterly dip (restored to remove Andean deformation) beneath an angular unconformity between Las Vacas and Trapiche beds is consistent geometrically with the trailing limb of a west-vergent fault-propagation anticline in the hanging wall of the subsurface Los Celestitos fault. The same angular unconformity truncates the El Corral fault and hanging-wall strata. In the Trapiche Formation, contrasting sedimentary facies from sandy turbidites westward to limestone-clast megabeds and olistoliths suggest another frontal

  9. Successive reactivation of older structures under variable heat flow conditions evidenced by K-Ar fault gouge dating in Sierra de Ambato, northern Argentine broken foreland

    NASA Astrophysics Data System (ADS)

    Nóbile, Julieta C.; Collo, Gilda; Dávila, Federico M.; Martina, Federico; Wemmer, Klaus

    2015-12-01

    The Argentine broken foreland has been the subject of continuous research to determine the uplift and exhumation history of the region. High-elevation mountains are the result of N-S reverse faults that disrupted a W-E Miocene Andean foreland basin. In the Sierra de Ambato (northern Argentine broken foreland) the reverse faults offset Neogene sedimentary rocks (Aconquija Fm., ˜9 Ma) and affect the basement comprising Paleozoic metamorphic rocks that have been dated at ˜477-470 Ma. In order to establish a chronology of these faults affecting the previous continuous basin we date the formation age of clay minerals associated with fault gouge using the K-Ar dating technique. Clay mineral formation is a fundamental process in the evolution of faults under the brittle regime (<<300 °C). K-Ar ages (9 fractions from 3 samples collected along a transect in the Sierra de Ambato) vary from Late Devonian to Late Triassic (˜360-220 Ma). This age distribution can be explained by a long lasting brittle deformation history with a minimum age of ˜360 Ma and a last clay minerals forming event at ˜220 Ma. Moreover, given the progression of apparent ages decreasing from coarse to fine size fractions (˜360-311 Ma for 2-1 μm grain size fraction, ˜326-286 Ma for 1-0.2 μm and ˜291-219 Ma of <0.2 μm), we modeled discrete deformation events at ˜417 Ma (ending of the Famatinian cycle), ˜317-326 Ma (end of Gondwanic orogeny), and ˜194-279 Ma (Early Permian - Jurassic deformation). According to our data, the Neogene reactivation would not have affected the K-Ar system neither generated a significant clay minerals crystallization in the fault gouge, although an exhumation of more than 2 Km is recorded in this period from stratigraphic data.

  10. Coordination of the U.S. DOE-Argentine National Atomic Energy Commission (CNEA) science and technology implementing arrangement. Final report

    SciTech Connect

    Ebadian, M.A.

    1998-01-01

    In 1989, the US Department of Energy (DOE) established the Office of Environmental Management (EM) and delegated to the office the responsibility of cleaning up the US nuclear weapons complex. EM`s mission has three primary activities: (1) to assess, remediate, and monitor contaminated sites and facilities; (2) to store, treat, and dispose of wastes from past and current operations; and (3) to develop and implement innovative technologies for environmental remediation. To this end, EM has established domestic and international cooperative technology development programs, including one with the Republic of Argentina. Cooperating with Argentine scientific institutes and industry meets US cleanup objectives by: (1) identifying and accessing Argentine EM-related technologies, thereby leveraging investments and providing cost-savings; (2) improving access to technical information, scientific expertise, and technologies applicable to EM needs; and (3) fostering the development of innovative environmental technologies by increasing US private sector opportunities in Argentina in EM-related areas. Florida International University`s Hemispheric Center for Environmental Technology (FIU-HCET) serves as DOE-OST`s primary technology transfer agent. FIU-HCET acts as the coordinating and managing body for the Department of Energy (DOE)-Argentina National Atomic Energy Commission (CNEA) Arrangement. Activities include implementing standard operating procedures, tracking various technical projects, hosting visiting scientists, advising DOE of potential joint projects based on previous studies, and demonstrating/transferring desired technology. HCET hosts and directs the annual Joint Coordinating Committee for Radioactive and Mixed Waste Management meeting between the DOE and CNEA representatives. Additionally, HCET is evaluating the possibility of establishing similar arrangements with other Latin American countries.

  11. Transcultural adaptation and validation of the CRAFFT as a screening test for problematic alcohol and substance use, abuse and dependence in a group of Argentine adolescents.

    PubMed

    Bertini, María Carolina; Busaniche, Julio; Baquero, Ferney; Eymann, Alfredo; Krauss, Mariana; Paz, Marcela; Catsicaris, Cristina

    2015-04-01

    Substance use and abuse and their consequences are a major problem among adolescents. The screening for problematic alcohol and substance use, abuse and dependence should be part of the case-taking process for adolescents. The Problem Oriented Screening Instrument for Teenagers (POSIT) and the Car, Relax, Alone, Forget, Family/Friends, Trouble questionnaire (CRAFFT) are used to this end. 17 items corresponding to substance use and abuse (POSITsua); it has been validated in Spanish. six questions; it has not been validated in Argentina. To assess the validity of a version of the CRAFFT screening test adapted to Spanish in a group of Argentine adolescents using the POSITsua test as reference. The CRAFFTa and the POSITsua tests were administered to 14-20 year-old adolescents. An affirmative answer was scored as 1, and a negative answer, as 0. An individual was considered to have an increased risk of problematic use, abuse and dependence if he/she scored >2 in the CRAFFTa and POSITsua tests. Two hundred and eighty-six adolescents were included; 52% were female; mean age: 16.6 years old. The CRAFFTa score was >2 for 29%, while the POSIT score was >2 for 37%. CRAFFTa sensitivity: 59%; specificity: 88%. CRAFFTa positive predictive value: 0.74; negative predictive value: 0.78. The area under the curve was 0.73. In the linear regression, the R for the six CRAFFT questions was 0.60. Gender and age did not modify results. Cronbach's alpha was 0.64. CRAFFTa sensitivity was 59%, and its specificity was 88%, compared to the POSITsua test as a screening tool for problematic alcohol and substance use, abuse and dependence among Argentine adolescents.

  12. Relationship Among Establishment Durations, Kin Relatedness, Aggressiveness, and Distance Between Populations of Eight Invasive Argentine Ant (Hymenoptera: Formicidae) Supercolonies in Japan.

    PubMed

    Sato, K; Sakamoto, H; Hirata, M; Kidokoro-Kobayashi, M; Ozaki, M; Higashi, S; Murakami, T

    2017-08-01

    We investigated kin relatedness and kin-recognition abilities of the Argentine ant, Linepithema humile (Mayr), an invader from North America that has pervaded Japan for 20 yr, using genetic analyses and behavioral bioassays. From these data and interactions among factors, we formulated an eradication and management time-scale pattern diagram. Relatedness within a colony using microsatellite markers was effectively zero, whereas relatedness estimated by multilocus DNA fingerprinting markers was relatively high. Specifically, relatedness of recently invaded populations was estimated at nearly 0.3. From the results of behavioral bioassays on the invading populations of the Argentine ant, all colonies except the Kobe supercolonies did not show clearly aggressive behaviors toward workers belonging to other colonies, even when distantly located. Because they are critical factors for eradicating and managing invasive organisms, we assessed the relationships among kin relatedness using multilocus DNA fingerprinting and microsatellite markers, with aggressiveness, in 2011 and 2012, including the establishment durations, and distances among supercolonies. A generalized linear model (GLM) analysis, with establishment durations as an explanatory variable, strongly contributed to explaining estimated relatedness from the two methods. Specifically, models using kin relatedness for both multilocus DNA fingerprinting and microsatellite markers provided the strongest contribution to explaining the establishment durations. Within 3 yr after establishment in a native area, eradication is possible because of their low genetic diversity and small colony size. After 15 yr, eradication will be more difficult, but it is preferable to just monitor the impact for a nonnative ecosystem. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Glyphosate and AMPA content in the PM10 emitted by a soil of the central semiarid region of Argentine (CSRA)

    NASA Astrophysics Data System (ADS)

    Mendez, Mariano; Aimar, Silvia; Aparicio, Virginia; Buschiazzo, Daniel; De Geronimo, Eduardo; Costa, Jose Luis

    2017-04-01

    Particle matter with aerodynamic diameter lesser than 10 um (PM10) has shown adverse effects on health even at low concentrations. Entic Haplustoll dominates central semiarid region of Argentine (CSRA) and PM10 are emitted from the soil by tillage and wind erosion. The aim of study was measure glyphosate concentration in the PM10 emitted by a soil fine-sandy loam Entic Haplustoll. The study was carried in Santa Rosa La Pampa (S36° 46´; W64° 16´; 210 m a.s.l.) in a plot where 3.7 kg ha-1 active ingredient of glyphosate was used in the last two year and glyphosate was not used in the last 12 months. Soil samples were air dried and sieved with a rotary sieve to separate the following aggregate fractions: <0.42 mm, 0.42 to 0.84 mm, 0.84 to 2 mm, 2 to 6.4 mm, 6.4 to 19.2 mm, and > 19.2 mm. The Easy Dust Generator (EDG) was used to generate dust from the soil and its aggregate fractions. The PM10 emitted by EDG was collected using an electrostatic precipitator (C&L model number GH-939). The following determinations were carried out in the soil, aggregates and PM10 emitted by them: organic matter contents (OM) (Walkley & Black, 1934), particle size composition (Malvern martersizer2000) and the Glyphosate and AMPA content. Results showed that mean geometric diameter (MGD) of the material collected in the electrostatic precipitator and emitted by the aggregate fraction and the soil was between 4.6 and 5.3 µm. OM content in the aggregates fraction and soil ranged between 1.4% and 2.9% while than in the PM10 emitted by them ranged between 3.5% and 3.7 %. Clay content in aggregates and soil ranged between 6.5% and 8.5% while than in PM10 emitted by them ranged between 17.5% and 19.0%. Glyphosate content in aggregates fraction and soil ranged between 1 and 3 ppb. Glyphosate in PM10 emitted by aggregates and soil did not show differences in despite of it ranged between 11.0 ppb and 19.5 ppb. OM and clay in aggregate fractions and PM10 do not explained glyphosate content in

  14. Presence of harbour seals ( Phoca vitulina) may increase exploitable fish biomass in the Strait of Georgia

    NASA Astrophysics Data System (ADS)

    Li, Lingbo; Ainsworth, Cameron; Pitcher, Tony

    2010-10-01

    We tested what degree harbour seal ( Phoca vitulina) populations compete with fisheries for commercially harvested species, and to what degree seal populations depend on exploited species as prey. In the Strait of Georgia (SoG), harbour seals mainly feed on fisheries target species, Pacific herring ( Clupea pallasii) and Pacific hake ( Merluccius productus), while herring is also a main prey of hake. Using an Ecopath model constructed based on 2005 conditions, we ran three scenarios: altering herring fishing mortality, removing seal populations and sensitivity analyses of the herring vulnerability parameter. Our results show that with more herring available, the seal population will increase greatly, but with less herring available, the seal populations in the SoG decreases gradually. Our model suggests that the total biomass of commercial fish populations in the SoG may decrease substantially with seals absent. A cull of harbour seals may not increase total fisheries catch in the SoG. Herring benefit from seal predation on herring’s largest predator, hake, so that herring may decline when seals are removed. However, this result is highly dependent on model parameterization. When juvenile herring are considered less vulnerable to hake predation (i.e., when we assume there are many refuges in which to hide), the herring population is less negatively impacted by seal removals. This indicates that survival during this crucial life-stage is important to herring abundance. The model also suggests that, with seals removed, the ecosystem would be dominated by hake.

  15. Ingestion of microplastics by demersal fish from the Spanish Atlantic and Mediterranean coasts.

    PubMed

    Bellas, Juan; Martínez-Armental, José; Martínez-Cámara, Ariana; Besada, Victoria; Martínez-Gómez, Concepción

    2016-08-15

    Microplastic pollution has received increased attention over the last few years. This study documents microplastic ingestion in three commercially relevant demersal fish species from the Spanish Atlantic and Mediterranean coasts, the lesser spotted dogfish Scyliorhinus canicula, the European hake Merluccius merluccius and the red mullet Mullus barbatus. Overall 212 fish were examined, 72 dogfish, 12 hakes and 128 red mullets. The percentage of fish with microplastics was 17.5% (15.3% dogfish, 18.8% red mullets and 16.7% hakes), averaging 1.56±0.5 items per fish, and the size of the microplastics ranged from 0.38 to 3.1mm. These fish species are used currently as biomonitors for marine pollution monitoring within the Spanish Marine Pollution Monitoring Programme (SMP), and may be as well suitable candidates for monitoring spatial and temporal trends of ingested litter. The data presented here represent a baseline for the implementation of the Marine Strategy Framework Directive descriptor 10 in Spain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Climate variability, precipitation trends, and impacts on surface processes in humid to arid climate transition zones of the NW Argentine Andes (24° S, 65° W)

    NASA Astrophysics Data System (ADS)

    Castino, Fabiana; Bookhagen, Bodo; Strecker, Manfred

    2015-04-01

    In the Andes of NW Argentina the distribution and amount of rainfall and associated surface processes are intimately correlated with pronounced topographic gradients and relief contrasts that intercept easterly moisture-bearing winds related to the South American Monsoon System. These conditions have led to a pronounced elevation-dependent distribution of rainfall, which involves areally limited transition zones between the humid eastern flanks of the orogen (eastern foreland and eastern flanks of the E Cordillera) and the arid orogen interior (Puna Plateau). At interannual scales rainfall patterns in this area can be modulated by different atmospheric disturbances, such as the South Atlantic Convergent Zone and the El Niño Southern Oscillation, resulting in drought or flooding events. During the last two decades, field observations document fluvial aggradation in many intermontane valleys along the eastern flanks of the orogen. This may be related to changing overall climatic conditions, impacting hillslope erosion processes at high elevation, but contemporaneously overwhelming the fluvial system and reducing transport capacity, leading to transient sediment storage. We analyzed rainfall trends in the humid to arid climatic transition zone in the NW Argentine Andes over different time periods to characterize the spatiotemporal variability of rainfall patterns during the last five decades. We relied on both daily ground station (40 stations, 1956-2012) and three-hourly remote sensing rainfall data (3B42 V7 TRMM data, 1998-2014). Seasonal total anomalies analysis shows a complex rainfall pattern, reflected both in station data and remote sensing observations with clear positive (negative) statistically significant trends in the northern Puna Plateau and in the northern part of the foreland basin (southern part of the eastern foreland basin) of up to +20mm/yr (-20mm/yr). Quantile regression of three-hourly and daily data furthermore shows that, on average

  17. Discussion about decision support systems using continuous multi-criteria methods for planning in areas with hydro-basins, agriculture and forests, from examples in Argentine.

    NASA Astrophysics Data System (ADS)

    Anton, J. M.; Grau, J. B.; Tarquis, A. M.; Andina, D.; Cisneros, J. M.; Sanchez, E.

    2012-04-01

    The authors were involved last years in projects considering diverse decision problems on the use of some regions in Argentine, and also related to rivers or rural services in them. They used sets of multi-criteria decision methods, first discrete when the problem included few distinct alternatives, such as e.g. forestry, traditional or intensive agriculture. For attributes they were different effects, classified then in environmental, economic and social criteria. Extending to other gentler areas, such as at South of the Province of Córdoba, Arg., they have balanced more delicately effects of continuous levels of actions, with a combination of Goal Programming linked methods, and they adopted compromises to have precise solutions. That has shown, and in part open, a line of research, as the setting of such models require various kinds of definitions and valuations, including optimizations, goals with penalties in deviations and restrictions. That can be in diverse detail level and horizon, in presence of various technical and human horizons, and that can influence politics of use of terrain and production that will require public and private agents. The research will consider consideration of use and conservation of soils, human systems and agro productions, and hence models for optimization, preferably in such Goal Programming ways. That will require considering various systems of models, first in theory to be reliable, and then in different areas to evaluate the quality of conclusions, and maybe that successively if results are found advantageous. The Bayesian ways will be considered, but they would require a prospective of sets of precise future states of nature or markets with elicited probabilities, which are neither evident nor decisive for the moment, as changes may occur in years but will be very unexpected or uncertain. The results will be lines of models to aid to establish policies of use of territories, by public agencies setting frames for private

  18. A comparison of spring larval fish assemblages in the Strait of Georgia (British Columbia, Canada) between the early 1980s and late 2000s

    NASA Astrophysics Data System (ADS)

    Guan, Lu; Dower, John F.; McKinnell, Skip M.; Pepin, Pierre; Pakhomov, Evgeny A.; Hunt, Brian P. V.

    2015-11-01

    The concentration and composition of the larval fish assemblage in the Strait of Georgia (British Columbia, Canada) has changed between the early 1980s (1980 and 1981) and the late 2000s (2007, 2009 and 2010). During both periods, the spring larval fish assemblages were dominated by pelagic species: Clupea pallasi (Pacific herring), Merluccius productus (Pacific hake), Leuroglossus schmidti (northern smoothtongue) and Theragra chalcogramma (walleye Pollock). The average concentration of Merluccius productus, Theragra chalcogramma, Leuroglossus schmidti, and Sebastes spp. declined between the early 1980s and the late 2000s; in contrast, the absolute concentration and proportion of Pleuronectidae and several demersal fish taxa increased in the spring larval assemblage. Examination of the associations between larval fish assemblages and environmental fluctuations suggests that large-scale climate processes are potential contributors to variations in overall larval concentrations of the dominant taxa and assemblage composition in the Strait of Georgia.

  19. From fish chemical characterisation to the benefit-risk assessment--part A.

    PubMed

    Afonso, Cláudia; Lourenço, Helena Maria; Cardoso, Carlos; Bandarra, Narcisa Maria; Carvalho, Maria Luísa; Castro, Matilde; Nunes, Maria Leonor

    2013-04-15

    Proximate composition, fatty acid profile, cholesterol, α-tocoferol content and essential (K, Na, Cl, S, Mg, Ca, Zn, Cu, Fe, Mn, and Se) and contaminant element (Hg/MeHg, Cd, Pb, and As) levels in silver scabbardfish (Lepidopus caudatus), hake (Merluccius merluccius), and ray (Raja spp.) were investigated. Results showed that these species contain high protein, low cholesterol and energy levels, being its consumption recommended. Polyunsaturated fatty acids (PUFA) were the dominant group of the fatty acids, being 80% of the n-3 family. Attending to the dietary reference intakes (DRIs), these fish species are a good source of Se and the other minerals can give a relevant contribution to the DRIs in a balanced diet. More than one weekly meal of silver scabbardfish has to be avoided due to the organic mercury concentration. More accurate dietary recommendations require a probabilistic assessment, which will be the focus of this study's Part B.

  20. Passive acoustic monitoring, development of disturbance calls and differentiation of disturbance and advertisement calls in the Argentine croaker Umbrina canosai (Sciaenidae).

    PubMed

    Tellechea, J S; Fine, M L; Norbis, W

    2017-04-01

    Disturbance and advertisement calls of the Argentine croaker Umbrina canosai were recorded from coastal Uruguayan waters. Dissections indicate typical sciaenid extrinsic swimbladder muscles present exclusively in males. Disturbance calls were produced when captive U. canosai were startled, chased with a net or grabbed by the tail. Calls were unusual for sciaenids because each pulse consisted of multiple cycles. The number of cycles per pulse and dominant frequency did not change with U. canosai size, but pulse duration and interpulse interval increased. Advertisement calls were recorded from unseen choruses in the field and confirmed with captive individuals in a large tank. Advertisement calls were recorded throughout the known range of the species in Uruguay indicating a continuous belt of spawning populations. Tank recordings of the same individuals permitted explicit comparisons between the two calls. Advertisement call pulses averaged 2·4 more cycles (11·0-8·6) although pulses of both calls were basically similar as were durations and dominant frequencies. Pulse number, however, differed markedly, averaging 13·6 and 3·4 pulses for disturbance and advertisement calls respectively. Furthermore, disturbance calls were produced as a rapid series with an interpulse interval of 26-31 ms whereas advertisement call patterns were less stereotyped and ranged from <100 to 450 ms. Multicycle pulses distinguished U. canosai from other sympatric sciaenids. © 2017 The Fisheries Society of the British Isles.

  1. Analysis of the pX region of bovine leukemia virus in different clinical stages of Enzootic Bovine Leukemia in Argentine Holstein cattle.

    PubMed

    Panei, Carlos Javier; Serena, María Soledad; Metz, Germán Ernesto; Bravi, María Emilia; González, Ester Teresa; Echeverría, María Gabriela

    2013-01-01

    Bovine leukemia virus (BLV) infection in cattle causes Enzootic Bovine Leukemia (EBL). About 30% of infected cattle develop persistent lymphocytosis (PL), a 0.1-5% develops tumors, and a 70% remains asymptomatic in an aleukemic stage (AL). Regulatory genes of BLV (Tax, Rex, R3 and G4) are located in a region known as pX(BLV). The variability of those genes had been postulated with the progression of the disease. The aim of this work was to compare the wild-type proviral pX(BLV) region at different stages of BLV natural infected cattle from Argentine Holstein. Pairs of primers were designed to amplify the proviral pX region of 12 cattle by PCR, and products were then sequenced, aligned and compared both with each other and with the reference sequence. Results show a divergence percentage from 0 to 6.1 for the Tax gene, from 0 to 9.4% for the Rex gene, from 0 to 12.1% for the R3 gene and finally from 0 to 6.5% for the G4 gene. Results obtained with hierarchical clustering showed two clusters well differentiated, where the members of each cluster are cattle that had tumor, PL and AL, not allowing differentiate those two cluster by clinical stage. Copyright © 2012. Published by Elsevier B.V.

  2. [Quali-quantitative study of the social variables defining transmission scenarios of Argentine Hemorrhagic Fever in the provinces of Buenos Aires and Santa Fe, 2001-2010].

    PubMed

    Mastrangelo, Andrea; Tagliabue, Paula; Berro, Lorena; De Carolis, Darío; Sinchi, Anabel; Digilio, Clara; Enria, Delia

    2014-08-01

    The aim of this paper was to characterize transmission scenarios of Argentine Hemorrhagic Fever in the post-vaccination period (2001-2010). The study was made up of three phases. The first consisted of a quantitative analysis using the database of the Dr. Julio I. Maiztegui National Institute of Human Viral Diseases [Instituto Nacional de Enfermedades Virales Humanas] regarding the confirmed cases in the period of study (221 cases). Taking into account the transmission site and the known endemic area, cases were grouped into three hypothetical transmission scenarios, identified as: a) classical, b) emerging-reemerging, c) traveling. In the second phase, in order to test these hypotheses, in-depth interviews were carried out from August to September 2011 within an intentionally selected sample of patients distributed proportionally among the three hypotheses. Finally, in the third stage, the data obtained for each hypothetical scenario were grouped into three spatiotemporal scales: the microscale (subject), the mesoscale (locality) and macroscale (region). The results show that new transmission sites are associated with the social dynamics of cereal production and port-bound routes.

  3. Tethyan calpionellids in the Neuquén Basin (Argentine Andes), their significance in defining the Jurassic/Cretaceous boundary and pathways for Tethyan-Eastern Pacific connections

    NASA Astrophysics Data System (ADS)

    López-Martínez, Rafael; Aguirre-Urreta, Beatriz; Lescano, Marina; Concheyro, Andrea; Vennari, Verónica; Ramos, Victor A.

    2017-10-01

    The study of calpionellid distribution in the well-documented Las Loicas section of the Vaca Muerta Formation in the Neuquén Basin, Argentine Andes, allows the recognition of the upper part of the Crassicollaria Zone and the lower part of Calpionella Zone across the Jurassic/Cretaceous boundary. The Crassicollaria Zone, Colomi Subzone (Upper Tithonian) is composed of Calpionella alpina Lorenz, Crassicollaria colomi Doben, Crassicollaria parvula Remane, Crassicollaria massutiniana (Colom), Crassicollaria brevis Remane, Tintinnopsella remanei (Borza) and Tintinnopsella carpathica (Murgeanu and Filipescu). The Calpionella Zone, Alpina Subzone (Lower Berriasian) is indicated by the explosion of the small and globular form of Calpionella alpina dominating over very scarce Crassicollaria massutiniana. The FAD of Nannoconus wintereri can be clearly correlated with the upper part of Crassicollaria Zone and the FAD of Nannoconus kamptneri minor with the Calpionella Zone. Additional studies are necessary to establish a more detailed calpionellid biozonation and its correlation with other fossil groups. The present work confirms similar calpionellid bioevents in westernmost Tethys (Cuba and Mexico) and the Andean region, strengthening the Paleo-Pacific-Tethyan connections through the Hispanic Corridor already known from other fossil groups.

  4. [Comparison of FRAX Score without bone mineral density determination and the criteria proposed by the Argentine Osteoporosis Society for the use of antiresorptive therapy in postmenopausal women].

    PubMed

    Camporro, Fernando; Redondo, Laura; Bulacio, Exequiel; Gutiérrez Magaldi, Ignacio; Chamale, Elías; Sáenz, Fabián

    2015-01-01

    To identify patients at high risk of fracture using clinical risk factors could reduce health costs arising from the realization of a bone densitometry. The aim of this study was to compare the FRAX score without bone mineral density (BMD) with the criteria proposed by the Argentine Society of Osteoporosis (SAO) to consider starting antiresorptive treatment. We conducted an observational, cross-sectional study where 330 postmenopausal women between 40 and 90 years of age were included. The number of treatments given if the FRAX tool without BMD had been followed was compared with the number of treatments indicated using the SAO criteria. Using the SAO criteria, 85 (25.8%) patients would initiate antiresorptive treatment compared with 15 (4.5%) using the FRAX without BMD (p = 0.0019). Among the 67 patients with a diagnosis of osteoporosis by BMD determination, all of them (100%) would have received treatment by using the SAO criteria compared with 10 (15%) using the FRAX score (p = 0.011). The use of FRAX without BMD significantly underestimates the number of patients who should receive antiresorptive treatment. In patients diagnosed with osteoporosis by BMD, the FRAX score underestimates the number of patients to be treated.

  5. [New transmission scenarios of the Argentine hemorrhagic fever since the introduction of the live attenuated junin virus vaccine (Candid #1): an experience in migrant workers].

    PubMed

    Briggiler, Ana; Sinchi, Anabel; Coronel, Florencia; Sánchez, Zaida; Levis, Silvana; Taylor, Jorge; Enria, Delia

    2015-01-01

    The Argentine hemorrhagic fever (AHF) is a severe acute viral disease caused by the Junin virus of the Arenaviridae family. The AHF endemic area coincides geographically with the largest grain export agro-industrial complex of the country [Argentina]. Since the implementation of vaccination with the Candid #1 vaccine, a significant reduction in incidence was achieved and risk patterns were modified. A previous study allowed characterizing these changes and identifying three transmission scenarios: classic, emergent-reemergent, and traveler. The latter scenario includes seasonal migrant workers who move each year, mainly from the province of Santiago del Estero, the endemic area to work in the detasseling of maize. With the objective of protecting this group of workers, a prevention campaign was initiated which included: capacity building of health personnel in the province, health education, and immunization with the vaccine Candid #1. 3,021 workers were vaccinated. Prior to vaccination, serum samples were taken from a group of 104 volunteers. Tests for neutralizing antibodies specific to the Junin virus were performed and 6 (5.76%) tested positive. The unexpected finding of a high percentage of workers with antibodies suggests the need to evaluate several hypotheses: a) that the result is the product of non-probabilistic sampling; b) that it could be people who fell ill in previous travels, c) or who were vaccinated in previous travels; or d) consider this region as an emerging scenario.

  6. The influence of disturbed habitat on the spatial ecology of Argentine black and white tegu (Tupinambis merianae), a recent invader in the Everglades ecosystem (Florida, USA)

    USGS Publications Warehouse

    Klug, Page E.; Reed, Robert N.; Mazzotti, Frank J.; McEachern, Michelle A.; Vinci, Joy J.; Craven, Katelin K.; Yackel Adams, Amy A.

    2015-01-01

    The threat of invasive species is often intensified in disturbed habitat. To optimize control programs, it is necessary to understand how degraded habitat influences the behavior of invasive species. We conducted a radio telemetry study to characterize movement and habitat use of introduced male Argentine black and white tegus (Tupinambis merianae) in the Everglades of southern Florida from May to August 2012 at the core and periphery of the introduced range. Tegus at the periphery moved farther per day (mean 131.7 ± 11.6 m, n = 6) compared to tegus at the core (mean 50.3 ± 12.4 m, n = 6). However, activity ranges were not significantly smaller in the core (mean 19.4 ± 8.4 ha, n = 6) compared to periphery (mean 29.1 ± 5.2 ha, n = 6). Peripheral activity ranges were more linear due to activity being largely restricted to levee habitat surrounded by open water or marsh. Tegus were located in shrub or tree habitat (mean 96%) more often than expected based on random locations (mean 58%), and the percent cover of trees and shrubs was higher in activity ranges (mean 61%) than the general study area (17%). Our study highlighted the ability of tegus to spread across the Florida landscape, especially in linear disturbed habitats where increased movement occurred and in areas of altered hydrology where movement is not restricted by water.

  7. Paleogeographic significance of Clavohamulus hintzei Miller (Conodonta) and other Ibexian conodonts in an early Paleozoic carbonate platform facies of the Argentine Precordillera

    USGS Publications Warehouse

    Lehnert, O.; Miller, J.F.; Repetski, J.E.

    1997-01-01

    Pre-Tremadocian conodonts and trilobites and Tremadocian conodonts are reported from the Cambrian and Ordovician La Silla Formation in the Cerro La Silla section in east-southeast Ja??chal, San Juan Province, Argentina. A shallow marine conodont fauna contains elements of Clavohamulus hintzei Miller, a common species in North America, but reported for the first time from the early Paleozoic platform carbonates of the western Argentine Precordillera. The presence of this species suggests a correlation with the Clavohamulus hintzei conodont subbiozone of the Cordylodus intermedius conodont biozone in North America, considered Early Ordovician (Skullrockian Stage, Ibexian Series) in North America, but by South American and European standards, this biozone would be of latest Cambrian age. C. hintzei and associated conodonts of the La Silla Formation are typical of the tropical faunas of the North American Midcontinent Faunal Province; Late Cambrian trilobites from lower in the formation also are typical North American taxa. The presence of these faunas in the platform carbonates is consistent with plate reconstructions suggesting that the Precordillera was in a tropical or subtropical position close to Laurentia during the late Precambrian and early Paleozoic. These new paleontological data provide one more argument for recent models of the Precordillera as a displaced terrane derived from the Ouachita Embayment at the southern margin of Laurentia.

  8. Irradiation of Argentine (U,Pu)O 2 MOX fuels. Post-irradiation results and experimental analysis with the BACO code

    NASA Astrophysics Data System (ADS)

    Marino, Armando Carlos; Pérez, Edmundo; Adelfang, Pablo

    1996-04-01

    The irradiation of the first Argentine prototypes of pressurized heavy water reactor (PHWR) (U,Pu)O 2 MOX fuels began in 1986. These experiments were carried out in the High Flux Reactor (HFR)-Petten, Holland. The rods were prepared and controlled in the CNEA's α Facility. The postirradiation examinations were performed in the Kernforschungszentrum, Karlsruhe, Germany and in the Joint Research Center (JRC), Petten. The first rod has been used for destructive pre-irradiation analysis. The second one as a pathfinder to adjust systems in the HFR. Two additional rods including iodine doped pellets were intended to simulate 15 000 MWd/T(M) burnup. The remaining two rods were irradiated until 15 000 MWd/T(M). One of them underwent a final ramp with the aim of verifying fabrication processes and studying the behaviour under power transients. BACO (BArra COmbustible) code was used to define the power histories and to analyse the experiments. This paper presents a description of the different experiments and a comparison between the results of the postirradiation examinations and the BACO outputs.

  9. Long-term dynamics of the distribution of the invasive Argentine ant, Linepithema humile, and native ant taxa in northern California.

    PubMed

    Sanders, Nathan J; Barton, Kasey E; Gordon, Deborah M

    2001-03-01

    Invasive species, where successful, can devastate native communities. We studied the dynamics of the invasive Argentine ant, Linepithema humile, for 7 years in Jasper Ridge, a biological preserve in northern California. We monitored the distributions at the hectare scale of native ant taxa and L. humile in the spring and fall from 1993 to 1999. We also studied the invasion dynamics at a finer resolution by searching for ants in 1-m(2) plots. Our results are similar at both scales. The distributions of several native species are not random with regard to L. humile; the distributions of several epigeic species with similar habitat affinities overlap much less frequently than expected with the distribution of L. humile. We found that season had a significant influence on the distributions of L. humile and several native taxa. Over the 7-year period, L. humile has increased its range size in Jasper Ridge largely at the expense of native taxa, but there is seasonal and yearly variation in this rate of increase. Studies of invasions in progress which sample across seasons and years may help to predict the spread and effects of invasive species.

  10. Are economic evaluations and health technology assessments increasingly demanded in times of rationing health services? The case of the Argentine financial crisis.

    PubMed

    Rubinstein, Adolfo; Belizán, María; Discacciati, Vilda

    2007-01-01

    After 4 years of deepening recession, Argentina's economy plummeted after default in 2002. This crisis critically affected health expenditures and triggered acute rationing. Our objective was to explore health decision-makers' knowledge and attitudes about economic evaluations (EE) and whether health technology assessment (HTA) were increasingly used for decision making. A qualitative design based on semistructured interviews and focus groups was used to explore how decision makers belonging to different health sectors implement resource allocation decisions. Informants were mostly unaware of EE. The most important criteria mentioned to adopt a treatment were evidence of effectiveness, social/stakeholder demand, or resource availability. Despite general positive attitudes about EE, knowledge was rather limited. Although cost considerations were widely accepted by purchasers and managers, clinicians argued about these issues as interfering with the doctor-patient relationship. Other important perceived barriers to HTA use were lack of confidence in the transferability of studies conducted in developed countries and institutional fragmentation of the Argentine healthcare system. The new macroeconomic context was cited as a justification of implicit rationing measures. Although explicit priority setting was implemented by many purchasers and managers, HTA was not used to improve technical and/or allocative efficiency. The crisis seems to be a strong incentive to extend the use of HTA in Argentina, provided decision makers are aware as well as involved in the generation of local studies.

  11. Molecular identification, morphological characterization and new insights into the ecology of larval Pseudoterranova cattani in fishes from the Argentine coast with its differentiation from the Antarctic species, P. decipiens sp. E (Nematoda: Anisakidae).

    PubMed

    Timi, Juan T; Paoletti, Michela; Cimmaruta, Roberta; Lanfranchi, Ana L; Alarcos, Ana J; Garbin, Lucas; George-Nascimento, Mario; Rodríguez, Diego H; Giardino, Gisela V; Mattiucci, Simonetta

    2014-01-17

    Larvae of the genus Pseudoterranova constitute a risk for human health when ingested through raw or undercooked fish. They can provoke pseudoterranovosis in humans, a fish-borne zoonotic disease whose pathogenicity varies with the species involved, making their correct specific identification a necessary step in the knowledge of this zoonosis. Larvae of Pseudoterranova decipiens s.l. have been reported in several fish species from off the Argentine coasts; however, there are no studies dealing with their specific identification in this region. Here, a genetic identification and morphological characterization of larval Pseudoterranova spp. from three fish species sampled from Argentine waters and from Notothenia coriiceps from Antarctic waters was carried out. Larvae were sequenced for their genetic/molecular identification, including the mitochondrial cytochrome c oxidase subunit II (mtDNA cox2), the first (ITS-1) and the second (ITS-2) internal transcribed spacers of the nuclear ribosomal DNA, and compared with all species of the P. decipiens (sensu lato) species complex (sequences available in GenBank). Further, adults of Pseudoterranova spp. from the definitive host, the southern sea lion, Otaria flavescens, from Argentine and Chilean coasts were sequenced at the same genes. The sequences obtained at the ITS-1 and ITS-2 genes from all the larvae examined from fish of Argentine waters, as well as the adult worms, matched 100% the sequences for the species P. cattani. The sequences obtained at mtDNA cox2 gene for Antarctic larvae matched 99% those available in GenBank for the sibling P. decipiens sp. E. Both MP and BI phylogenetic trees strongly supported P. cattani and P. decipiens sp. E as two distinct phylogenetic lineages and depicted the species P. decipiens sp. E as sister taxon to the remaining taxa of the P. decipiens complex. Larval morphometry was similar between specimens of P. cattani from Argentina, but significantly different from those of P

  12. Results of treatment with an intensive combination induction regimen containing idarubicin in children with acute myeloblastic leukemia: preliminary report of the Argentine Group for Treatment of Acute Leukemia.

    PubMed

    Sackmann-Muriel, F; Fernández-Barbieri, M A; Santarelli, M T; Matus-Ridley, M; Rosso, A; Negri-Aranguren, P; Cerutti, I; Gomel, M; Kvicala, R

    1993-12-01

    In April 1990, the Argentine Group for Treatment of Acute Leukemia began a multicenter trial for the treatment of previously untreated acute myeloblastic leukemia patients who were under 21 years of age. Initial treatment consisted of an 8-day induction phase with cytarabine together with idarubicin on days 3 to 5 and etoposide on days 6 to 8. A multidrug consolidation phase was subsequently administered and, after a treatment-free interval of 2 to 4 weeks, two 5-day intensification courses with high-dose cytarabine and etoposide were delivered with a 4-week interval between each course. Continuation therapy was started 2 to 4 weeks after the second course, with 6-thioguanine daily and cytarabine daily for 4 days every 4 weeks. Treatment was stopped after 18 months in children in continuous complete remission. A preliminary evaluation of this ongoing study included 36 patients with a mean age of 7.5 years (age range, 5 months to 16 years). The majority of patients had a French-American-British classification of M2 (n = 13) or M4 (n = 8). Complete remission was achieved by 91.7% of patients, while one died from sepsis in bone marrow hypoplasia and two were regarded as treatment failures. At a median follow-up of 12 months (range, 2 to 23 months) there were 12 adverse events: six bone marrow relapses, one bone marrow/skin relapse, and five deaths in complete remission (all deaths occurred during the consolidation phase). During the induction phase most of the patients experienced prolonged myelosuppression, and grade 3 to 4 toxicity (according to the Children's Cancer Group criteria) was frequently seen. Alopecia was universal. However, toxicity was manageable. We conclude that idarubicin in combination with cytarabine and etoposide is a highly effective regimen for induction in children with acute myeloblastic leukemia.

  13. A comparative study of Trypanosoma cruzi infection in sylvatic mammals from a protected and a disturbed area in the Argentine Chaco.

    PubMed

    Orozco, M M; Enriquez, G F; Cardinal, M V; Piccinali, R V; Gürtler, R E

    2016-03-01

    Understanding the complex epidemiology of Trypanosoma cruzi transmission cycles requires comparative studies in widely different environments. We assessed the occurrence of T. cruzi infection in sylvatic mammals, their infectiousness to the vector, and parasite genotypes in a protected area of the Argentine Chaco, and compared them with information obtained similarly in a nearby disturbed area. A total of 278 mammals from >23 species in the protected area were diagnosed for T. cruzi infection using xenodiagnosis, kDNA-PCR and nuclear satellite DNA-PCR (SAT) from blood samples. The relative abundance and species composition differed substantially between areas. Didelphis albiventris opossums were less abundant in the protected area; had a significantly lower body mass index, and a stage structure biased toward earlier stages. The capture of armadillos was lower in the protected area. The composite prevalence of T. cruzi infection across host species was significantly lower in the protected area (11.1%) than in the disturbed area (22.1%), and heterogeneous across species groups. The prevalence of infection in D. albiventris and Thylamys pusilla opossums was significantly lower in the protected area (nil for D. albiventris), whereas infection in sigmodontine rodents was three times higher in the protected area (17.5 versus 5.7%). Parasite isolates from the two xenodiagnosis-positive mammals (1 Dasypus novemcinctus and 1 Conepatus chinga) were typed as TcIII; both specimens were highly infectious to Triatoma infestans. Fat-tailed opossums, bats and rodents were kDNA-PCR-positive and xenodiagnosis-negative. Desmodus rotundus and Myotis bats were found infected with T. cruzi for the first time in the Gran Chaco.

  14. Oral cancer mortality in the province of Cordoba, Argentine Republic in the period 1975-2000. A comparative study with other populations.

    PubMed

    Morelatto, Rosana Andrea; López de Blanc, Silvia Adriana

    2006-05-01

    Malignant neoplasm (MN) mortality worldwide ranks among the first four causes of death, in the 1990 decade (1-4). The aim of this work is to study the eight most frequent MN mortality rates, and especially that one caused by oral cancer (OC) in the province of Cordoba, Argentine Republic, in the period between 1975 and 2000, in order to analyze its characteristics and compare with other populations in America and Europe. The data were provided by the provincial and national Health Ministry and Globocan 2000. The highest male rates were those of Slovakia and France, prevailing lung and bronchus tumors; whereas in females the highest rate was that of breast cancer in the United Kingdom and Germany, and lung cancer in the United States. Regarding to OC in the populations under study, Slovakia and France held the highest rates for both sexes, being Cordoba and Argentina among the lowest values, especially in women. Tongue was the most frequent site in Cordoba (43.5%), followed by salivary glands (23.7%). Male prevailed over female and the oldest ages were observed in the period 1995-2000. The mortality rates by MN in all sites increased 6.6% in both sexes, and by OC 77% in women within the period under study in Cordoba. Oral cancer is a serious problem for public health causing great morbidity and mortality, a situation that has not improved in decades. Mortality rates are an important tool towards implementation and planning of health policies and programs for cancer prevention.

  15. Effects of cigarette smoking on early arthritis: a cross-sectional study-data from the Argentine Consortium for Early Arthritis (CONAART).

    PubMed

    Haye Salinas, María Jezabel; Retamozo, Soledad; Alvarez, Ana Cecilia; Maldonado Ficco, Hernán; Dal Pra, Fernando; Citera, Gustavo; Benegas, Mariana; Chaparro del Moral, Rafael; Rillo, Oscar; Secco, Anastasia; Marino Claverie, Lucila; Catalan Pellet, Antonio; Marcos, Josefina; García, Mercedes Argentina; Marcos, Juan Carlos; Barbaglia, Ana; Bellomio, Verónica; Berman, Alberto; Quiroz, Cristian; Soriano, Enrique R; Ceccato, Federico; Paira, Sergio; Vazquez, Doralia; Juarez, Vicente Ricardo; Velozo, Edson Javier; Salvatierra, Gabriela; Caeiro, Francisco

    2015-05-01

    Our objective was to analyze the effects of cigarette smoking on disease activity, functional capacity, radiographic damage, serology and presence of extraarticular manifestations in patients with rheumatoid arthritis and undifferentiated arthritis. This is a cross-sectional study of 1,305 patients (729 with rheumatoid arthritis and 576 with undifferentiated arthritis) from CONAART, the Argentine Consortium for Early Arthritis that includes patients older than 16 years with <2 years of disease. Sociodemographic data, clinical characteristics of the disease and smoking history were collected. In patients with rheumatoid arthritis the disease activity score of 28 joints was 5.4 ± 1.3 in current smokers, 5.2 ± 1.4 in former smokers and 5.1 ± 1.4 in never smokers (p = 0.011). The simple erosion narrowing score was higher in current smokers and former smokers than in never smokers (M 14.0, R Q 6.0-21.0; M 15.0, R Q 7.0-24.0; M 10.0, R Q 5.0-17.0; p = 0.006). Current smokers had higher rheumatoid factor titer (M 160.0, R Q 80.0-341.0) than former smokers (M 146.8, R Q 6.03-255.5) and never smokers (M 15.0, R Q 9.0-80.0) (p = 0.004). The variable independently associated with tobacco exposure was simple erosion narrowing score (OR = 1.03, 95 % CI 1.00-1.05; p = 0.012). In patients with undifferentiated arthritis, an association between smoking status and parameters of activity or radiographic damage was not observed. Neither was tobacco exposure related to the presence of extraarticular manifestations or to the degree of disability in any of the two groups of patients. No relation was found between disease activity and severity, and number of packs smoked per year. Tobacco.

  16. The Development of Low-Level Measurement Capabilities for Total and Isotopic Uranium in Environmental Samples at Brazilian and Argentine Laboratories by ABACC

    SciTech Connect

    Guidicini, Olga M.; Olsen, Khris B.; Hembree, Doyle M.; Carter, Joel A.; Whitaker, Michael; Hayes, Susan M.

    2005-07-01

    In June 1998, the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC), with assistance from the U.S. Department of Energy (DOE), began a program to assess environmental sampling and analysis capabilities at laboratories in Argentina and Brazil. The program began with staff training conducted in South America and the United States by Oak Ridge National Laboratory (ORNL) and Pacific Northwest National Laboratory (PNNL). Both laboratories are participating members of DOE’s Network of Analytical Laboratories (NWAL) that support IAEA’s environmental sampling program. During the initial planning meeting, representatives from ABACC and all the participating analytical laboratories supporting ABACC were briefed on how the first exercise would be managed and on key aspects necessary to analyze low-level environmental samples for uranium. Subsequent to this training, a laboratory evaluation exercise (Exercise 1) was conducted using standard swipe samples prepared for this exercise by the International Atomic Energy Agency (IAEA). The results of Exercise 1 determined that sample contamination was a major factor in the analysis, and a thorough review of laboratory procedures was required to reduce the level of contamination to acceptable levels. Following modification of sample preparation procedures, the laboratories performed Exercise 2, an analysis of a National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 1547, Peach Leaves. The results of Exercise 2 demonstrated that several laboratories were capable of accurately determining the total uranium and uranium isotopic distribution in the peach leaves. To build on these successes, Exercise 3 was performed using a series of standard swipe samples prepared by the IAEA and distributed to laboratories supporting ABACC and to PNNL and ORNL. The results of Exercise 3 demonstrate that ABACC now has support laboratories in both Argentina and Brazil, which are capable

  17. Gravimetric determination of the continental-oceanic boundary of the Argentine continental margin (from 36°S to 50°S)

    NASA Astrophysics Data System (ADS)

    Arecco, María Alejandra; Ruiz, Francisco; Pizarro, Guillermo; Giménez, Mario; Martínez, Patricia; Ramos, Víctor A.

    2016-01-01

    This paper presents the gravimetric analysis together with seismic data as an integral application in order to identify the continental-oceanic crust boundary (COB) of the Argentine continental margin from 36°S to 50°S in a continuous way. The gravimetric and seismic data are made up of large grids of data obtained from satellite altimetry and marine research. The methodology consists of three distinct methods: (i) the application of enhancement techniques to gravimetric anomalies, (ii) the calculation of crustal thinning from 3-D gravity inversion modelling of the crust-mantle discontinuity and (iii) 2-D gravimetric modelling supported by multichannel reflection and refraction seismic profiles. In the first method, the analytic signal, Theta map, and tilt angle and its horizontal derivative were applied. In the second method, crustal thickness was obtained as the difference in the depths of the crystalline basement and the crust-mantle discontinuity; the latter was obtained via gravimetric inversion. Finally, 2-D modelling was performed from free-air anomalies in two representative sections by considering as restriction surfaces those coming from the interpretation of seismic data. The results of the joint application of enhancement techniques and 2-D and 3-D modelling have enabled continuous interpretation of the COB. In this study, the COB was determined continuously from the integration of 2-D profiles of the enhancement techniques, taking account of crustal thickness and performing 2-D gravimetric modelling. The modelling technique was complemented by regional studies integrated with multichannel seismic reflection and seismic refraction lines, resulting in consistent enhancement techniques.

  18. Assessing potential for community-based management of peccaries through common pool resource theory in the rural area of the Argentine Chaco.

    PubMed

    Altrichter, Mariana

    2008-03-01

    Community-based management (CBM) has been recognized as an appropriate approach to conservation, assuming that local communities have higher stakes than the state in their natural resources and have better knowledge of local resources and, therefore, can manage them more efficiently. However, the implementation of CBM has not always been successful. The objective of this research was to assess the potential for the implementation of a governmental proposal for community-based management of peccaries (Tayassuidae) in the Impenetrable northern Argentine, through the examination of the reasons why arrangements to avoid overexploitation have not evolved in this region. I used the theory of common pool resources (CPRs) as a framework for this analysis. CPRs theory explains the conditions under which appropriators of a resource are likely to engage in devising and altering governing arrangements and the conditions under which such arrangements are likely to succeed. Fieldwork was conducted between June 2000 and August 2003 using a mixed methods approach. It was found that most of the condition of the resource and users identified by the CPR theory as associated with an increased likelihood of successful management of natural resources are absent or scarcely developed in the Impenetrable. Thus, the situation in the Impenetrable does not seem appropriate for the implementation of CBM of peccaries. It is first necessary to invest in training and development of local institutions' capacities and social capital. It is also important to increase the flow of relevant information, which will enable institutions to be effective, responsible, and accountable to the community. For the moment, a more appropriate approach will have to include a mixture of protectionism and comanagement of collared peccaries while the propitious conditions for a complete local management of the resource are developed.

  19. Deep-water fisheries at the Atlantic Frontier

    NASA Astrophysics Data System (ADS)

    Gordon, J. D. M.

    2001-05-01

    ( Micromesistius poutassou). The other semipelagic fishery is on spawning aggregations of the greater silver smelt or argentine ( Argentina silus). Spanish and UK vessels that target mainly hake ( Merluccius merluccius) and a Norwegian fleet that targets ling ( Molva molva), blue ling and tusk ( Brosme brosme) dominate the upper slope longline fishery. West of Shetland, the fishery on the upper slope has some similarities with that of the Hebridean slope, with anglerfish and blue ling being important target species. A quite different fishery occurs in the transition zone between the Atlantic and Norwegian Sea waters. Here the main target species is Greenland halibut ( Reinhardtius hippoglossoides). Below the transition zone biomass decreases rapidly and there is no fishery. It is generally agreed that many deep-water species have slow growth, a high age at first maturity and a low fecundity, which makes them vulnerable to over-exploitation. Other features of these fishes such as high mortality of discards and escapees will add to the problems. Despite this the only management procedures in place are general limitation of effort measures within the area of jurisdiction of the European Union.

  20. Plio-Pleistocene paleo-erosion rates as a recorder of orographic barrier uplift in the NW-Argentine Andes (Humahuaca Basin)

    NASA Astrophysics Data System (ADS)

    Pingel, Heiko; Schildgen, Taylor; Wittmann, Hella

    2017-04-01

    As an integral part of the Eastern Cordillera, the intermontane Humahuaca Basin in the NW Argentine Andes is located in transition between the arid and internally drained Puna Plateau to the west and the humid broken foreland to the east. In combination with moisture-bearing air masses sourced in the Atlantic Ocean and the Amazon Basin, the present-day topographic gradient of the eastern Andean margin comprises an efficient orographic barrier that results in a strong precipitation gradient, with rainfall of more than 2,000 mm/a along the eastern flanks and <200 mm/a on the plateau. Ultimately, variable moisture availability affects surface processes, such as fluvial erosion and transport of eroded material, with decreasing erosion rates towards the orogenic hinterland. Paleoenvironmental reconstructions of the Humahuaca Basin suggest that this region became disconnected from the foreland during the Mio-Pliocene by the growth of fault-bounded mountain ranges. This led to an increase in accommodation space and enabled the trapping of largely fluvial, late Miocene to Quaternary basin filling units. Subsequently, the basin was uplifted and internally deformed. Fossil records, sedimentologic evidence, and stable-isotopes (δD from volcanic glass) moreover imply that the re-routing of the fluvial network, an initial increase in precipitation, and, as the windward ranges attained threshold elevations to incoming moisture, reduced moisture availability by ca. 3 Ma, were all a consequence of the Mio-Pliocene uplift. In this study, we present first results of terrestrial cosmogenic nuclide-derived paleo-erosion rates from quartz-bearing fluvial sands and gravels of known stratigraphic age. In most cases, the age control is based on previously published U-Pb zircon data of intercalated volcanic ash deposits, but also utilizes new OSL and AMS14C ages. A reassessment of the sediment-accumulation history of the basin highlights important changes of the depositional system

  1. Determination of soil degradation in argentine semi-arid environments from remote sensors: case department of patagones, province of buenos aires

    NASA Astrophysics Data System (ADS)

    Pezzola, Alejandro; Cacella, Alejandra; Enrique, Mario; Winschel, Cristina

    2017-04-01

    The continental territory of the Argentine Republic owns 75% of its surface under arid and semiarid conditions to the west of the meridian of 64°. Wind erosion is the main physical cause of desertification. In the Pampena area, studies showed that the sandy loam soils were more pronounced than the sandy loam with significant losses of organic matter, decreases in the cation exchange capacity and modification of the mineral composition of the very fine sand fraction (From 73 to 100 μm), with increases in the proportion of heavy minerals (magnetite) relative to light (quartz). In the Patagones department, Buenos Aires province, the soils with a sandy-loamy texture, which are transported by wind and deposited on calcium carbonate (tosca), with little moisture retention and susceptible to wind erosion. In the 1980s and 1990s, increases in rainfall above the historical average led to a shift of the isohytes towards the southwest, leading to agricultural intensification that caused greater pressure on the soil and native vegetation. This advance on the native vegetation within the Patagones produced a reduction between 1975 and 2009 of 432,280 ha, leaving only 31% of the area covered by native forest - shrub xerophyte today. Between 2005-2009, the call "agricultural drought" caused losses in crops, wheat - oats and natural pastures associated with the native forest, causing a significant deterioration of the soil, exposing them to wind erosion. Remote sensors represent a very valuable technology for the mapping and evaluation of soil erosion. The availability of multispectral images allows the mapping and monitoring of changes in the dynamics of the erosion process. The objective of this work was to make an expeditious diagnosis of the surface affected by wind erosion and to evaluate the degree to which the soils destined for agriculture and livestock were affected. For this purpose, Terra's MODIS (Moderate-Resolution Imaging Spectroradiometer) sensor information was

  2. Diet of bottlenose dolphins (Tursiops truncatus) from the Gulf of Cadiz: Insights from stomach content and stable isotope analyses.

    PubMed

    Giménez, Joan; Marçalo, Ana; Ramírez, Francisco; Verborgh, Philippe; Gauffier, Pauline; Esteban, Ruth; Nicolau, Lídia; González-Ortegón, Enrique; Baldó, Francisco; Vilas, César; Vingada, José; G Forero, Manuela; de Stephanis, Renaud

    2017-01-01

    The ecological role of species can vary among populations depending on local and regional differences in diet. This is particularly true for top predators such as the bottlenose dolphin (Tursiops truncatus), which exhibits a highly varied diet throughout its distribution range. Local dietary assessments are therefore critical to fully understand the role of this species within marine ecosystems, as well as its interaction with important ecosystem services such as fisheries. Here, we combined stomach content analyses (SCA) and stable isotope analyses (SIA) to describe bottlenose dolphins diet in the Gulf of Cadiz (North Atlantic Ocean). Prey items identified using SCA included European conger (Conger conger) and European hake (Merluccius merluccius) as the most important ingested prey. However, mass-balance isotopic mixing model (MixSIAR), using δ13C and δ15N, indicated that the assimilated diet consisted mainly on Sparidae species (e.g. seabream, Diplodus annularis and D. bellottii, rubberlip grunt, Plectorhinchus mediterraneus, and common pandora, Pagellus erythrinus) and a mixture of other species including European hake, mackerels (Scomber colias, S. japonicus and S. scombrus), European conger, red bandfish (Cepola macrophthalma) and European pilchard (Sardina pilchardus). These contrasting results highlight differences in the temporal and taxonomic resolution of each approach, but also point to potential differences between ingested (SCA) and assimilated (SIA) diets. Both approaches provide different insights, e.g. determination of consumed fish biomass for the management of fish stocks (SCA) or identification of important assimilated prey species to the consumer (SIA).

  3. Assessment of the F9 genotype-specific FIX inhibitor risks and characterization of 10 novel severe F9 defects in the first molecular series of Argentine patients with haemophilia B

    PubMed Central

    Radic, Claudia Pamela; Rossetti, Liliana Carmen; Abelleyro, Miguel Martín; Candela, Miguel; Bianco, Raúl Pérez; Pinto, Miguel de Tezanos; Larripa, Irene Beatriz; Goodeve, Anne; De Brasi, Carlos Daniel

    2014-01-01

    In Haemophilia B (HB) (factor IX (FIX) deficiency), F9 genotype largely determines clinical phenotype. Aimed to characterise Argentine families with HB, this study presents F9 genotype frequencies and their specific FIX inhibitor risk and 10 novel F9 mutations. Ninety-one DNA samples from HB patients and relatives were subjected to a new scheme: a primary screen for large deletions, a secondary screen for point mutations using conformation sensitive gel electrophoresis, DNA-sequencing and bioinformatic analysis. Our unbiased HB population (N=52)(77% with severe, 11.5% moderate and 11.5% mild HB) showed 32 missense (61.5%) including three novel mutations predicting specific structural/functional defects in silico, 7 nonsense (13.5%)(one novel), 5 large deletions, 4 splice including three novel mutations affecting predicted splicing scores, 3 indels (two novel) and one Leiden mutation. Our comprehensive HB population included five patients with long-lasting FIX inhibitors: three nonsense (p.E35* (novel), p.R75*, p.W240*) and two entire-F9 deletions. A further patient with an indel (p.A26Rfs*14) developed transient inhibitors. A case-control analysis, based on our global prevalence of 3.05% for developing inhibitors in HB revealed that missense mutations were associated with a low risk odds ratio (OR) of 0.05 and a prevalence of 0.39%, whereas nonsense and entire-F9 deletions had significantly higher risks (OR 11.0 and 32.7) and prevalence (14.3% and 44.5%, respectively). Our cost-effective practical approach enabled identification of the causative mutation in all 55 Argentine families with HB, analysis of the molecular pathology of novel F9 defects and determination of mutation-associated FIX inhibitor risks. PMID:23093250

  4. Hypertension and the risk of acute myocardial infarction in Argentina. The Argentine Factores de Riesgo Coronario en America del Sur (FRICAS) Investigators.

    PubMed

    Ciruzzi, M; Pramparo, P; Rozlosnik, J; Zylberstjn, H; Delmonte, H; Haquim, M; Abecasis, B; de La Cruz Ojeda, J; Mele, E; La Vecchia, C; Schargrodsky, H

    2001-01-01

    interval, 2.40-4.87) when the value was >140 mm Hg. If the most recent diastolic blood pressure was less-than-or-equal90 mm Hg, the risk increased more than two fold (odds ratio=2.48; 95% confidence interval, 1.91-3.22), and if it was >90 mm Hg, it increased nearly four-fold (odds ratio=3.72; 95% confidence interval, 2.33-5.96). In smokers, the odds ratio was 2.28 in the absence of hypertension and increased to 7.51 when hypertension was present. In this Argentine population, hypertension is a strong and independent risk factor for acute myocardial infarction. In routine clinical practice, the control of blood pressure to levels below 140/90 seems to be required in order to reduce part (but not all) of the risk of acute myocardial infarction in hypertensive patients. (c) 2001 by CHF, Inc.

  5. Argentine tango: Another behavioral addiction?

    PubMed Central

    Targhetta, Remi; Nalpas, Bertrand; Pascal, Perney

    2013-01-01

    Background: Behavioral addiction is an emerging concept based on the resemblance between symptoms or feelings provided by drugs and those obtained with various behaviors such as gambling, etc. Following an observational study of a tango dancer exhibiting criteria of dependence on this dance, we performed a survey to assess whether this case was unique or frequently encountered in the tango dancing community. Methods: We designed an online survey based on both the DSM-IV and Goodman's criteria of dependence; we added questions relative to the positive and negative effects of tango dancing and a self-evaluation of the degree of addiction to tango. The questionnaire was sent via Internet to all the tango dancers subscribing to “ToutTango”, an electronic monthly journal. The prevalence of dependence was analyzed using DSM-IV, Goodman's criteria and self-rating scores separately. Results: 1,129 tango dancers answered the questionnaire. Dependence rates were 45.1, 6.9 and 35.9%, respectively, according to the DSM-IV, Goodman's criteria and self-rating scores. Physical symptoms of withdrawal were reported by 20% of the entire sample and one-third described a strong craving for dancing. Positive effects were high both in dependent and non-dependent groups and were markedly greater than negative effects. Long practice of tango dancing did not modify the dependence rate or reduce the level of positive effects. Conclusions: Tango dancing could lead to dependence as currently defined. However, this dependence is associated with marked and sustained positive effects whilst the negative are few. Identifying the precise substratum of this dependence needs further investigation. PMID:25215199

  6. Drought Analysis in Northeastern Argentine

    NASA Astrophysics Data System (ADS)

    Garcia, N. O.

    2005-12-01

    The objetive of the present work was analyze the occurrence of droughts in the context of the climatic variability, in a wide region of the Argentinean territory that encompass the six provinces of the northeastern (Misiones, Corrientes, Entre Rios, Santa Fe, Chaco and Formosa). In order to define the droughts a decilic analysis of the monthly precipitation records was used, and the temporal and spatial variability were analyzed with Spectral Analysis of the composite dry year (From January of the year of droughts onset until December of the following year), this period contain the complete hydrologic dry-year. It was observed that the occurrence of annual droughts change along the last century, verifying an average of one drought each three years up to 1969 and one drought each five year from 1970. From the point of view of the relative amount of fallen water, it was observed that the extreme dry periods take place in autumn, winter and spring and weak dry period during the summer or to along the complete hydrologic year. The spatial and temporal behavior of the dry periods showed that the composite dry-years are more significant in amplitude and phase than composite LA NIÑA years. So much the rains of summer like the winters droughts accentuate the second harmonic amplitude, that contains information of the amount of fallen water and also represent the annual cycle of the precipitations, while the droughts of summer attenuate it. The harmonic dials in the analyzed region showed that the second spectral component is the most significant, while the first component indicates their relationship with the region EL NIÑO, in the Equatorial Pacific Ocean. The results indicate a regional homogeneous characterization regarding the first harmonic in the north, the same as the area center-eastern, while the southwest and south area has a behavior with characteristic very particular characteristics during the dry events (second harmonic not significant).

  7. NASA Spacecraft Tracks Argentine Flooding

    NASA Image and Video Library

    2015-08-19

    Northwest of Buenos Aires, Argentina, seven straight days of torrential rains of up to 16 inches 40 centimeters in August 2015 resulted in flooding between the cities of Escobar and Campana as seen by NASA Terra spacecraft. The flooding has since eased, allowing some evacuated residents of the 39 affected municipalities to return to their homes. The flooding was captured in this satellite image acquired Aug. 16, 2015, by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft. The image covers an area of 16.7 by 17.4 miles (26.9 by 28 kilometers), and is located at 34.2 degrees south, 58.6 degrees west. http://photojournal.jpl.nasa.gov/catalog/PIA19871

  8. [Argentine Consensus of Respiratory Rehabilitation].

    PubMed

    Sívori, Martín; Benzo, Roberto; Rhodius, Edgardo; Jolly, Enrique; Boim, Clarisa; Saadia, Marcela; Conti, Ernesto; Guevara, Ivan; Carles, Daniel; Victorio, Carlos; Santini, Fabian; Ratto, Patricia; Capparelli, Ignacio; Prieto, Ernesto; Azvalinsky, Marcos; Alais, Maria

    2004-01-01

    A group of pulmonologists and physical therapists from the Asociacion Argentina de Medicina Respiratoria revised the scientific literature on Respiratory Rehabilitation (RR) to elaborate evidence-based national recommendations to promote its use. RR is a multidisciplinary program of care for patients with chronic respiratory impairment, individually tailored, designed to optimize physical and social performance and autonomy of patients. It is particularly indicated in patients with Chronic Obstructive Pulmonary Disease (COPD) with exercise intolerance. Inclusion and exclusion criteria, guidelines for initial evaluation and follow up have been defined. The resources needed were defined. It was recommended a hospital ambulatory program with domiciliary complement. A pulmonologist and physical therapist were required for the program as minimum. Aerobic training was recommended for lower limb (LL) (Evidence A) and upper limb (UL) (Evidence B), strength training for LL and UL (Evidence C), as well as respiratory muscles training by resistive inspiratory threshold load (Evidence D) and other physiotherapy techniques were recommended for specific patients. In addition recommendations have been made for educational objectives of the program, nutritional and psychological support. The positive impact of RR on health care was analyzed through the reduction in exacerbation of COPD, length of hospital stay and cost. RR is a key component in the treatment of COPD patients. This evidenced-based consensus statement was prepared to provide recommendations to be implemented nationally.

  9. Predicting Argentine Jet Fuel Prices

    DTIC Science & Technology

    2007-03-01

    Federico Sturzenegger. La Privatización de Reservas en el Sector Hidrocarburifero. El caso de Argentina. Torcuato Di Tella University. Buenos Aires...for Business and Economics (9th Edition). New Jersey. Pearson, 2005. Mercuri Pablo Antonio . “Asimetrías en la respuesta de los precios de los...combustibles líquidos a cambios en el precio del crudo: El caso argentino.” Political Economy Asociation., XXXIV Annual Meeting, 2001. 14 August 2006

  10. Silver Hake Tracks Changes in Northwest Atlantic Circulation

    EPA Science Inventory

    Recent studies documenting shifts in spatial distribution of many organisms in response to a warming climate highlight the need to understand the mechanisms underlying species distribution at large spatial scales. Here we present one noteworthy example of remote oceanographic pro...

  11. Silver Hake Tracks Changes in Northwest Atlantic Circulation

    EPA Science Inventory

    Recent studies documenting shifts in spatial distribution of many organisms in response to a warming climate highlight the need to understand the mechanisms underlying species distribution at large spatial scales. Here we present one noteworthy example of remote oceanographic pro...

  12. Species- and size-specific variability of mercury concentrations in four commercially important finfish and their prey from the northwest Atlantic.

    PubMed

    Staudinger, Michelle D

    2011-04-01

    Total mercury was analyzed as a function of body length, season, and diet in four commercially and recreationally important marine fish, bluefish (Pomatomus saltatrix), goosefish (Lophius americanus), silver hake (Merluccius bilinearis), and summer flounder (Paralichthys dentatus), collected from continental shelf waters of the northwest Atlantic Ocean. Mercury levels in the dorsal muscle tissue of 115 individuals ranged from 0.006 to 1.217 μg/g (wet weight) and varied significantly among species. The relationship between predator length and mercury concentration was linear for bluefish and summer flounder, while mercury levels increased with size at an exponential rate for silver hake and goosefish. Mercury burdens were the highest overall in bluefish, but increased with size at the greatest rate in silver hake. Seasonal differences were detected for bluefish and goosefish with mercury levels peaking during summer and spring, respectively. Prey mercury burdens and predator foraging habits are discussed as the primary factors influencing mercury accumulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Assessment of ochratoxin A occurrence in Argentine red wines using a novel sensitive quechers-solid phase extraction approach prior to ultra high performance liquid chromatography-tandem mass spectrometry methodology.

    PubMed

    Mariño-Repizo, Leonardo; Gargantini, Raquel; Manzano, Humberto; Raba, Julio; Cerutti, Soledad

    2017-06-01

    The assessment of ochratoxin A (OTA) in wine is relevant for food safety and its continuous control allows to reduce the risk of intake. Thus, a novel sensitive QuEChERS-SPE (Quick, Easy, Cheap, Effective, Rugged and Safe - Solid Phase Extraction) pretreatment prior to liquid chromatography coupled to tandem mass spectrometry was developed for the determination of OTA in red wine samples from different grape-growing regions in Argentine. A sensitive methodology was achieved and thus the limits of detection and quantification were 0.02 and 0.05 µg L(-1) , respectively. Recoveries ranged from 89.0% to 105.3%. The method was applied to 136 red wine samples (Argentina's flagship varieties: Malbec and Cabernet Sauvignon) from ten grape-growing regions, during vintages 2013-2015. Although all of the samples investigated were contaminated with OTA (concentrations ranged from 0.02 to 0.98 µg L(-1) ), the levels detected were lower than the maximum allowable concentration limit of 2.0 µg L(-1) established by international regulations. The methodology proposed is suitable for reliable OTA analysis in red wines. Similarly, the values obtained from the samples analyzed were in accordance with the current regulations and, as a consequence, preventive actions to reduce this mycotoxin incidence can be undertaken. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. [First Argentine consensus guidelines for in vitro antimicrobial susceptibility testing of clinically relevant anaerobic bacteria in humans/ Anaerobic Subcommittee of the Asociación Argentina de Microbiología].

    PubMed

    Legaria, María C; Bianchini, Hebe M; Castello, Liliana; Carloni, Graciela; Di Martino, Ana; Fernández Canigia, Liliana; Litterio, Mirta; Rollet, Raquel; Rossetti, Adelaida; Predari, Silvia C

    2011-01-01

    Through time, anaerobic bacteria have shown good susceptibility to clinically useful antianaerobic agents. Nevertheless, the antimicrobial resistance profile of most of the anaerobic species related to severe infections in humans has been modified in the last years and different kinds of resistance to the most active agents have emerged, making their effectiveness less predictable. With the aim of finding an answer and for the purpose of facilitating the detection of anaerobic antimicrobial resistance, the Anaerobic Subcommittee of the Asociación Argentina de Microbiología developed the First Argentine consensus guidelines for in vitro antimicrobial susceptibility testing of clinically relevant anaerobic bacteria in humans. This document resulted from the compatibilization of the Clinical and Laboratory Standards Institute recommendations, the international literature and the work and experience of the Subcommittee. The Consensus document provides a brief taxonomy review, and exposes why and when anaerobic antimicrobial susceptibility tests should be conducted, and which antimicrobial agents can be used according to the species involved. The recommendations on how to perform, read and interpret in vitro anaerobic antimicrobial susceptibility tests with each method are exposed. Finally, the antibiotic susceptibility profile, the classification of antibiotics according to their in vitro activities, the natural and acquired mechanisms of resistance, the emerging resistance and the regional antibiotic resistance profile of clinically relevant anaerobic species are shown.

  15. Rescue from Cloned cDNAs and In Vivo Characterization of Recombinant Pathogenic Romero and Live-Attenuated Candid #1 Strains of Junin Virus, the Causative Agent of Argentine Hemorrhagic Fever Disease ▿

    PubMed Central

    Emonet, Sebastien F.; Seregin, Alexey V.; Yun, Nadezhda E.; Poussard, Allison L.; Walker, Aida G.; de la Torre, Juan C.; Paessler, Slobodan

    2011-01-01

    The New World arenavirus Junin virus (JUNV) is the causative agent of Argentine hemorrhagic fever (AHF), which is associated with high morbidity and significant mortality. Several pathogenic strains of JUNV have been documented, and a highly attenuated vaccine strain (Candid #1) was generated and used to vaccinate the human population at risk. The identification and functional characterization of viral genetic determinants associated with AHF and Candid #1 attenuation would contribute to the elucidation of the mechanisms contributing to AHF and the development of better vaccines and therapeutics. To this end, we used reverse genetics to rescue the pathogenic Romero and the attenuated Candid #1 strains of JUNV from cloned cDNAs. Both recombinant Candid #1 (rCandid #1) and Romero (rRomero) had the same growth properties and phenotypic features in cultured cells and in vivo as their corresponding parental viruses. Infection with rRomero caused 100% lethality in guinea pigs, whereas rCandid #1 infection was asymptomatic and provided protection against a lethal challenge with Romero. Notably, Romero and Candid #1 trans-acting proteins, L and NP, required for virus RNA replication and gene expression were exchangeable in a minigenome rescue assay. These findings support the feasibility of studies aimed at determining the contribution of each viral gene to JUNV pathogenesis and attenuation. In addition, we rescued Candid #1 viruses with three segments that efficiently expressed foreign genes introduced into their genomes. This finding opens the way for the development of a safe multivalent arenavirus vaccine. PMID:21123388

  16. Intra-annual recruitment events of a shelf species around an island system in the NW Mediterranean

    NASA Astrophysics Data System (ADS)

    Hidalgo, M.; Tomás, J.; Moranta, J.; Morales-Nin, B.

    2009-06-01

    Seasonal pattern of fish recruitment can vary over years, and the coupling of such pattern with favourable trophic-environmental conditions may trigger non-stationary and non-linear effects on the yearly recruitment variability. The relative contribution of intra-annual discrete recruitment events (REs) to recruitment is often the basis of the inter-annual fluctuations in abundance and biomass of exploited fish populations which are based on a small number of age classes. In this study, REs of European hake ( Merluccius merluccius L.) were identified in the north and south of the Balearic Islands (NW Mediterranean) during the 2004 recruitment season and investigated for growth and physiological and morphological condition. Five REs were identified with different contributions in abundance to the annual recruitment in each area coming from different intra-annual spawning batches. Growth rates were similar between the REs with the exception of the last event of the season. Conversely, large differences in morphological and physiological condition were observed between REs and were due to: different environmental-trophic scenarios encountered, and ontogenetic changes related to the recruitment to the shelf-break grounds (ca. 11 cm, 5-6 months of life) which triggered a trade-off in the energy allocation strategy. The spatial-temporal variability in the physiological condition among REs at the beginning of the recruitment season might be explained in the basis on a 'condition expanded match-mismatch hypothesis'. We advance that individuals recruiting in the north, which were in better condition and temporally and spatially differenced from the south, have most probably hatched in separated locations with different food availability for larvae and early life stages. We propose that hake recruiting to the north and south of the island are from different origins, mainland and the islands respectively, and have benefited from different environmental conditions. This

  17. 77 FR 66169 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery Management Plan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-02

    ... silver hake, northern red hake, southern red hake, and offshore hake), and is managed through a series of... 25th percentile for both silver hake stocks. In order to account for offshore hake, which are caught.... There is no overfishing definition for offshore hake because there is insufficient information for...

  18. Absence of an N-Linked Glycosylation Motif in the Glycoprotein of the Live-Attenuated Argentine Hemorrhagic Fever Vaccine, Candid #1, Results in Its Improper Processing, and Reduced Surface Expression

    PubMed Central

    Manning, John T.; Seregin, Alexey V.; Yun, Nadezhda E.; Koma, Takaaki; Huang, Cheng; Barral, José; de la Torre, Juan C.; Paessler, Slobodan

    2017-01-01

    Junin virus (JUNV), a highly pathogenic New World arenavirus, is the causative agent of Argentine hemorrhagic fever (AHF). The live-attenuated Candid #1 (Can) strain currently serves as a vaccine for at-risk populations. We have previously shown that the Can glycoprotein (GPC) gene is the primary gene responsible for attenuation in a guinea pig model of AHF. However, the mechanisms through which the GPC contributes to the attenuation of the Can strain remain unknown. A more complete understanding of the mechanisms underlying the attenuation and immunogenicity of the Can strain will potentially allow for the rational design of additional safe and novel vaccines. Here, we provide a detailed comparison of both RNA and protein expression profiles between both inter- and intra-segment chimeric JUNV recombinant clones expressing combinations of genes from the Can strain and the pathogenic Romero (Rom) strain. The recombinant viruses that express Can GPC, which were shown to be attenuated in guinea pigs, displayed different RNA levels and GPC processing patterns as determined by Northern and Western blot analyses, respectively. Analysis of recombinant viruses containing amino acid substitutions selected at different mouse brain passages during the generation of Can revealed that altered Can GPC processing was primarily due to the T168A substitution within G1, which eliminates an N-linked glycosylation motif. Incorporation of the T168A substitution in the Rom GPC resulted in a Can-like processing pattern of Rom GPC. In addition, JUNV GPCs containing T168A substitution were retained within the endoplasmic reticulum (ER) and displayed significantly lower cell surface expression than wild-type Rom GPC. Interestingly, the reversion A168T in Can GPC significantly increased GPC expression at the cell surface. Our results demonstrate that recombinant JUNV (rJUNV) expressing Can GPC display markedly different protein expression and elevated genomic RNA expression when compared to

  19. Hummocky cross-stratification-like structures and combined-flow ripples in the Punta Negra Formation (Lower-Middle Devonian, Argentine Precordillera): A turbiditic deep-water or storm-dominated prodelta inner-shelf system?

    NASA Astrophysics Data System (ADS)

    Basilici, Giorgio; de Luca, Pedro Henrique Vieira; Poiré, Daniel G.

    2012-08-01

    Turbidity-current and storm-induced deposits may exhibit similarities, in particularly when the latter is laid down by a combination of oscillatory and unidirectional flows. Recent progress in facies analysis helps to discriminate the sedimentary effects of oscillatory from unidirectional components of the flow. On the basis of detailed analysis of sedimentary facies, strata geometry, and palaeocurrent data, the present study reinterprets the Punta Negra Formation (PNF) (Lower-Middle Devonian, Argentine Precordillera), previously considered as a depositional system of deep-water, as a storm-dominated prodeltaic shelf depositional system. In the sandstone beds of the PNF, planar, low-angle and undulating laminations with weakly asymmetric hummocky and swaley bedforms, combined-flow ripples, accretionary hummocky cross-stratification-like (HCS-like), and anisotropic HCS-like suggest the action of oscillatory currents combined with unidirectional currents in forming the deposits. Different hypotheses on the origin of the oscillatory currents have been examined. The most convincing interpretation is that the oscillatory component of the velocity is attributed to storm-induced waves. The palaeocurrent data indicate offshore current directions, suggesting that the unidirectional flow was a gravity-induced bottom current. Inverse grading at the base and overlying normally graded divisions of the sandstone beds testify to waxing-waning behaviour of the depositional flows; interbedding of sedimentary structures (undulating laminations, low-angle and parallel laminations, and combined-flow ripples) in the lower and intermediate divisions of the beds indicate fluctuations of flow velocity. This organisation of the sedimentary structures permits association of the unidirectional component with hyperpycnal bottom currents. The terrestrial origin of the hyperpycnal flows is suggested by the abundance of terrestrial plant remains, the mineralogical and textural immaturity of the

  20. Trophic structure of pelagic species in the northwestern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Albo-Puigserver, Marta; Navarro, Joan; Coll, Marta; Layman, Craig A.; Palomera, Isabel

    2016-11-01

    Ecological knowledge of food web interactions within pelagic marine communities is often limited, impairing our capabilities to manage these ecologically and economically important marine fish species. Here we used stable isotope analyses to investigate trophic interactions in the pelagic ecosystem of the northwestern Mediterranean Sea during 2012 and 2013. Our results suggest that European sardine, Sardina pilchardus, and anchovy, Engraulis encrasicolus, are consumers located at relatively low levels of the pelagic food web. Unexpectedly, the round sardinella, Sardinella aurita, appeared to be located at a higher trophic level than the other small pelagic fish species, although previous studies found similarity in their diets. Isotope data suggested that trophic niches of species within the genera Trachurus spp. and Scomber spp., were distinct. Atlantic bonito Sarda sarda, European hake Merluccius merluccius and European squid Loligo vulgaris, appeared to feed at higher trophic levels than other species. Despite some intraspecific seasonal variability for some species, community trophic structure appeared relatively stable through the year. These data provide an important step for developing models of food web dynamics in the northwestern Mediterranean Sea.

  1. Polycyclic aromatic hydrocarbons in marine organisms from the Gulf of Naples, Tyrrhenian Sea.

    PubMed

    Perugini, Monia; Visciano, Pierina; Manera, Maurizio; Turno, Giuseppe; Lucisano, Antonia; Amorena, Michele

    2007-03-07

    Polycyclic aromatic hydrocarbons (PAHs) were determined by an HPLC method with fluorescence detection in bivalves (Mitylus galloprovincialis), cephalopods (Todarodes sagittatus), crustaceans (Aristeus antennatus), and fish (Mullus surmeletus, Scomber scombrus, Micromesistius poutassou, and Merluccius merluccius) caught in the Gulf of Naples (Tyrrhenian Sea, Italy). Anthracene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, and benzo(k)fluoranthene were detected, at different concentrations, in all of the examined marine organisms, whereas benzo(a)pyrene, dibenz(a,h)anthracene, benzo(g,h,i)perylene, and indeno(1,2,3-cd)pyrene were found only in Mediterranean mussels. Of mussels collected in winter 71.43% exceeded the maximum residual levels (MRL) fixed for the benzo(a)pyrene in European Regulation 208/2005/EC, whereas all samples collected in summer reported values lower than this limit. In comparison to the other marine organisms, the mussels showed the highest PAH concentrations (p < 0.01). Fish showed total PAH levels lower than those of cephalopods and, in particular, European hake showed the lowest values (6.06 ng/g of fresh weight).

  2. Behaviour of fish by-catch in the mouth of a crustacean trawl.

    PubMed

    Queirolo, D; Gaete, E; Montenegro, I; Soriguer, M C; Erzini, K

    2012-06-01

    The behaviour of fish by-catch was recorded and characterized by in situ observations in the mouth of a crustacean trawl using an underwater camera system with artificial light, at depths between 106 and 461 m, along the central coast of Chile. The groups or species studied were rattails (family Macrouridae), Chilean hake Merluccius gayi gayi, sharks (orders Carcharhiniformes and Squaliformes), skates (family Rajidae), flatfishes (genus Hippoglossina) and small benthopelagic and demersal fishes (orders Osmeriformes, Stomiiformes, Gadiformes, Ophidiiformes and Perciformes). The fish behaviour was categorized in terms of (1) position in the water column, (2) initial orientation with respect to the trawl, (3) locomotion and (4) swimming speed with respect to the trawl. Rattails, sharks, skates and flatfishes were passive in response to the trawl and showed similar behavioural patterns, with most fishes observed sitting or touching the bottom with no swimming or other activity. Merluccius gayi gayi was the most active species, displaying a wide combination of behavioural responses when the trawl approached. This species showed several behavioural patterns, mainly characterized by swimming forward at variable speed. A fraction of small bentho-pelagic and demersal fishes also showed an active behaviour but always at lower speed than the trawl. The species-specific differences in behaviour in the mouth of the trawl suggest that improvements at the level of the footrope can be made to reduce by-catch, especially of passive species.

  3. Ecology and Genetic Structure of Zoonotic Anisakis spp. from Adriatic Commercial Fish Species

    PubMed Central

    Poljak, Vedran

    2014-01-01

    Consumption of raw or thermally inadequately treated fishery products represents a public health risk, with the possibility of propagation of live Anisakis larvae, the causative agent of the zoonotic disease anisakidosis, or anisakiasis. We investigated the population dynamics of Anisakis spp. in commercially important fish—anchovies (Anisakis), sardines (Sardina pilchardus), European hake (Merluccius merluccius), whiting (Merlangius merlangus), chub mackerel (Scomber japonicus), and Atlantic bluefin tuna (Thunnus thynnus)—captured in the main Adriatic Sea fishing ground. We observed a significant difference in the numbers of parasite larvae (1 to 32) in individual hosts and between species, with most fish showing high or very high Anisakis population indices. Phylogenetic analysis confirmed that commercial fish in the Adriatic Sea are parasitized by Anisakis pegreffii (95.95%) and Anisakis simplex sensu stricto (4.05%). The genetic structure of A. pegreffii in demersal, pelagic, and top predator hosts was unstructured, and the highest frequency of haplotype sharing (n = 10) was between demersal and pelagic fish. PMID:24317085

  4. Ecology and genetic structure of zoonotic Anisakis spp. from adriatic commercial fish species.

    PubMed

    Mladineo, Ivona; Poljak, Vedran

    2014-02-01

    Consumption of raw or thermally inadequately treated fishery products represents a public health risk, with the possibility of propagation of live Anisakis larvae, the causative agent of the zoonotic disease anisakidosis, or anisakiasis. We investigated the population dynamics of Anisakis spp. in commercially important fish-anchovies (Anisakis), sardines (Sardina pilchardus), European hake (Merluccius merluccius), whiting (Merlangius merlangus), chub mackerel (Scomber japonicus), and Atlantic bluefin tuna (Thunnus thynnus)-captured in the main Adriatic Sea fishing ground. We observed a significant difference in the numbers of parasite larvae (1 to 32) in individual hosts and between species, with most fish showing high or very high Anisakis population indices. Phylogenetic analysis confirmed that commercial fish in the Adriatic Sea are parasitized by Anisakis pegreffii (95.95%) and Anisakis simplex sensu stricto (4.05%). The genetic structure of A. pegreffii in demersal, pelagic, and top predator hosts was unstructured, and the highest frequency of haplotype sharing (n = 10) was between demersal and pelagic fish.

  5. Removal of Anisakis simplex allergens from infected fish during the washing step of surimi production.

    PubMed

    Olivares, Fabiola; González-Muñoz, Miguel; Carballeda-Sangiao, Noelia; Rodríguez-Mahillo, Ana; Careche, Mercedes; de Las Heras, Cristina; Navas, Alfonso; Tejada, Margarita

    2015-10-01

    The washing operation of fish muscle is one of the key steps in the production of surimi. The aim of this study was to assess in parasitised minced fish the effect of the washing steps on the allergen removal of Anisakis simplex and on protein yield during surimi processing. Experimentally infected hake (Merluccius merluccius) (50 Anisakis simplex s.s L3 larvae per 100 g of muscle) underwent three successive washing steps with water, phosphate buffer (20 mmol L(-1) ), sodium bicarbonate (60 mmol L(-1) ), or sodium hypochlorite (0.27 mmol L(-1) ) in the surimi processing (4 kg muscle, 1:4 w/v for each solution). Total protein concentration and A. simplex antigens and allergens were evaluated in each waste fraction. The highest removal of Ani s 4 and A. simplex antigens was achieved by using phosphate buffer, together with a good protein yield in the raw surimi. Decrease of the concentration of allergens and antigens as a function of the washing steps rendered a linear trend (R(2) = 0.95 and 0.98 for Ani s 4 and A. simplex antigens, respectively). The conditions for an optimal removal of Anisakis allergens can be established and calculated as a function of the washing steps. This approach opens a line to utilise parasitised fish in a safer way. © 2014 Society of Chemical Industry. © 2014 Society of Chemical Industry.

  6. Identification of gadoid species in fish meat by polymerase chain reaction (PCR) on genomic DNA.

    PubMed

    Hubalkova, Zora; Kralik, Petr; Kasalova, Janka; Rencova, Eva

    2008-05-28

    Identification of fish species is significant due to the increasing interest of consumers in the meat of sea fish. Methods focusing on fish species identification help to reveal fraudulent substitution among economically important gadoid species in commercial seafood products. The objective of this work was to develop a conventional PCR method for the differentiation of the following gadoid fish species in fish products: Alaska pollack ( Theragra chalcogramma), blue whiting ( Micromesistius poutassou), hake spp. ( Merluccius spp.), Atlantic cod ( Gadus morhua), saithe ( Pollachius virens), and whiting ( Merlangius merlangus). The species-specific primer pairs for gadoid species determination were based on the partial pantophysin I ( PanI) genomic sequence. Sequence identification was confirmed by cloning and sequencing of the PCR products obtained from the species considered. For the simultaneous detection of Alaska pollack, blue whiting, and hake spp., a quadruplex PCR system was constructed. Other gadoid species were detected in separate PCR reactions. After optimization of the reactions, the developed PCR systems were used for the analysis of codfish samples obtained from the Czech market and the customs' laboratories. This method represents an alternative approach in the use of genomic DNA for the identification of fish species. This method is rapid, simple, and reliable without the need for further confirmative methods. Furthermore, the identification of a mixture of more than one species is possible. The PCR system has been optimized for routine diagnostic purposes.

  7. Variation in wind and piscivorous predator fields affecting the survival of Atlantic salmon, Salmo salar, in the Gulf of Maine

    USGS Publications Warehouse

    Friedland, K.D.; Manning, J.P.; Link, Jason S.; Gilbert, J.R.; Gilbert, A.T.; O'Connell, A.F.

    2012-01-01

    Observations relevant to the North American stock complex of Atlantic salmon, Salmo salar L., suggest that marine mortality is influenced by variation in predation pressure affecting post-smolts during the first months at sea. This hypothesis was tested for Gulf of Maine (GOM) stocks by examining wind pseudostress and the distribution of piscivorous predator fields potentially affecting post-smolts. Marine survival has declined over recent decades with a change in the direction of spring winds, which is likely extending the migration of post-smolts by favouring routes using the western GOM. In addition to changes in spring wind patterns, higher spring sea surface temperatures have been associated with shifting distributions of a range of fish species. The abundance of several pelagic piscivores, which based on their feeding habits may predate on salmon post-smolts, has increased in the areas that serve as migration corridors for post-smolts. In particular, populations of silver hake, Merluccius bilinearis (Mitchell), red hake, Urophycis chuss (Walbaum), and spiny dogfish, Squalus acanthias L., increased in size in the portion of the GOM used by post-smolts. Climate variation and shifting predator distributions in the GOM are consistent with the predator hypothesis of recruitment control suggested for the stock complex.

  8. The Southern Argentine Agile Meteor Radar (SAAMER)

    NASA Astrophysics Data System (ADS)

    Janches, Diego

    2014-11-01

    The Southern Argentina Agile Meteor Radar (SAAMER) is a new generation system deployed in Rio Grande, Tierra del Fuego, Argentina (53 S) in May 2008. SAAMER transmits 10 times more power than regular meteor radars, and uses a newly developed transmitting array, which focuses power upward instead of the traditional single-antenna-all-sky configuration. The system is configured such that the transmitter array can also be utilized as a receiver. The new design greatly increases the sensitivity of the radar enabling the detection of large number of particles at low zenith angles. The more concentrated transmitted power enables additional meteor studies besides those typical of these systems based on the detection of specular reflections, such as routine detections of head echoes and non-specular trails, previously only possible with High Power and Large Aperture radars. In August 2010, SAAMER was upgraded to a system capable to determine meteoroid orbital parameters. This was achieved by adding two remote receiving stations approximately 10 km away from the main site in near perpendicular directions. The upgrade significantly expands the science that is achieved with this new radar enabling us to study the orbital properties of the interplanetary dust environment. Because of the unique geographical location, SAAMER allows for additional inter-hemispheric comparison with measurements from Canadian Meteor Orbit Radar, which is geographically conjugate. Initial surveys show, for example, that SAAMER observes a very strong contribution of the South Toroidal Sporadic meteor source, of which limited observational data is available. In addition, SAAMER offers similar unique capabilities for meteor showers and streams studies given the range of ecliptic latitudes that the system enables detailed study of showers at high southern latitudes (e.g July Phoenicids or Puppids complex). Finally, SAAMER is ideal for the deployment of complementary instrumentation in both, permanent and campaign, operational mode. Results from various radar meteor investigations as well as radar/optical observation campaign will be presented in this paper.

  9. Argentine Air Power in the Falklands War

    DTIC Science & Technology

    1988-05-01

    p. 161 8 local tactical air support, and forward air control. Tht; Comando Aviacion Naval Argentina (CANA), or the aviation element of the Navy, was... Aviacion del Ejercito (CAE), the aviation element of the Army, also made no new organizational changes for the war. CAE deployed from its main base at

  10. Antiviral activity in Argentine medicinal plants.

    PubMed

    Kott, V; Barbini, L; Cruañes, M; Muñoz, J D; Vivot, E; Cruañes, J; Martino, V; Ferraro, G; Cavallaro, L; Campos, R

    1999-01-01

    In an ethnopharmacological screening of selected medicinal plants used in Argentina for the treatment of infectious diseases, aqueous extracts of five species were assayed in vitro to detect antiviral activity against herpes simplex virus type 1 (HSV-1), respiratory syncytial virus (RSV) and adenovirus serotype 7 (ADV-7). Polygonum punctatum, Lithraea molleoides, Sebastiania brasiliensis and Sebastiania klotzschiana but not Myrcianthes cisplatensis showed in vitro antiherpetic activity with 50% effective dose (ED50) ranging from 39 to 169 microg/ml. P. punctatum, L. molleoides and M. cisplatensis showed antiviral activity against RSV with ED50 ranging from 78 to 120 microg/ml. None of the extracts had antiviral activity against ADV-7. The differences between their maximal non cytotoxic concentration and their antiviral activity values were high enough to justify further analysis.

  11. [Argentine guidelines for urticaria and angioedema].

    PubMed

    Máspero, Jorge; Cabrera, Hugo; Ardusso, Ledit; De Gennaro, Mónica; Fernández Bussy, Ramón; Galimany, José; Galimberti, Daniel; Label, Marcelo; La Forgia, Marta; Medina, Iris; Neffen, Hugo; Troielli, Patricia

    2014-01-01

    This interdisciplinary paper summarizes the news in the diagnosis and treatment of chronic urticaria (CU), and provides concepts, definitions and evidence-based suggestions for its management. Urticaria occurs in at least 20% of the population at some point in their lives. Acute urticaria (less than 6 weeks' duration), differs from CU in its etiology, but the onset of this disease is always acute. CU may occur as spontaneous (SCU) or induced (ICU). The diagnosis is simple, although a careful evaluation is necessary for differential diagnosis. ICU's diagnosis is mainly clinical, even if provocation tests can be useful. Supplementary studies should be limited and based on the clinical suspicion. Treatment may be divided into three approaches: avoidance, elimination or treatment of the cause, and pharmacological treatment. Recently treatment has been modified with the use of second-generation antihistamines as first-line and increased doses of nonsedating H1 antihistamines, up to 4 times, as second line. Antihistamines are essential to treat CU; however, 40% of patients do not achieve good control despite increased doses and require additional treatment. The most recent evidence indicates a group of drugs to be used as third line in these cases, to improve quality of life and to limit toxicity from frequent or chronic use of systemic steroids. Only 3 drugs are recommended as third line: omalizumab, cyclosporin A or anti-leukotrienes.

  12. The basins on the Argentine continental margin

    SciTech Connect

    Urien, C.M.

    1996-08-01

    After the stabilization of the central Gondwana Craton, orogenic belts were accreted, as a result of convergence events and an extensive passive margin developed in southwestern Gondwana. Thermal subsidence in Parana, Karoo-Ventania basins and the Late Paleozoic-Early Mesozoic rifts, were modified by the Gondwana breakup and the South Atlantic opening. Early Paleozoic marine transgressions deposited the Table Mountain Group in Ventania. In southwestern Patagonia foreland clastics were deposited. Magmatic arcs and marine units indicate a tectonic trough was formed, alternating with continental sequences, over Late Paleozoic metamorphics and intrusives, resulting from plastered terrains along the Gondwana margin. In Patagonia, Permo-Carboniferous continental and glacio marine clastics infill the basins, while in Ventania, paralic sequences, grade from neritic to continental to the northeast, extending beneath the continental margin. The Triassic-Jurassic rift basins progressed onto regional widespread acid lavas and were infilled by lagoonal organic-rich sequences. Early drift phase built basins transverse to the margin, with fluvio-lacustrine sequences: Salado, Colorado, Valdes-Rawson, San Julian and North Malvinas intracratonic basins, which underwent transtensional faulting. Post-Oxfordian to Neocomian brackish sequences, onlapped the conjugate basins during the margin`s drift, with petroleum systems, as in Austral and Malvinas. In the Valanginian, basic extrusions commenced to form on the continental border, heralding the oceanic phase. Due to thermal subsidence, offlaping sediments prograded onto the remaining half-grabens. Several petroleum systems, proven and hypothetical, are identified in this region.

  13. Argentine Flooding Observed by NASA Satellite

    NASA Image and Video Library

    2016-01-07

    Since August 2015, heavy rains have caused rivers to overflow and forced tens of thousands from their homes in Paraguay, Argentina and Brazil. Rosario, Argentina is located 186 miles (300 kilometers) northwest of Buenos Aires, on the western shore of the Parana River. The entire Parana River floodplain for hundreds of kilometers is still under water or wet, as seen in this image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft, acquired Jan. 6, 2016. The image covers an area of 30.8 by 33.9 miles (49.5 by 54.6 kilometers), and is located at 33 degrees south, 61 degrees west. http://photojournal.jpl.nasa.gov/catalog/PIA20295

  14. Argentine plant increases capacity, improves NGL recoveries

    SciTech Connect

    Lynch, J.T.; Fernandez, C.L.

    1997-10-06

    Total cryogenic processing capacity at Transportadora de Gas del Sur S.A.`s (TGS) Cerri complex in Bahia Blanca, Argentina, is being increased from 22 MMcmd to 40 MMcmd (776 to 1,410 MMcfd) with a future ethane-recovery capacity of 1,900 metric tons/day (mtd; 33,600 b/d) using Ortloff technology. Very high propane recovery can be maintained as the ethane recovery is controlled over a range of 1,000--1,900 mtd as needed to meet local ethane demand. Total NGL recovery can be increased from 2,600 mtd to 4,500 mtd without additional compression. The paper describes current operations, inlet-residue compression, train retrofit, C{sub 3} recovery, C{sub 2} rejection, C{sub 2} recovery, and the final dual-mode design.

  15. Transformation of the Argentine wholesale electricity market

    SciTech Connect

    Caruso, L.M. )

    1994-06-01

    The electricity industry in Argentina has undertaken a very deep restructuring in recent years, from a 100% state-owned, integrated activity to a true market of electricity, in which more than seventy free private agents (generators, transmission companies, distribution companies, and big customers) operate in a framework of rules completely different from those in force at the beginning of the transformation. Today, almost 3 years later, an observer can notice a number of changes already in place. As a consequence, there is an increased interest from companies and government as well, in old and new issues such as electrical markets integration, or global business. The purpose of this presentation is to examine this emergent market, its rules, and its players, and to assess which of the patterns associated with the integration of business, markets, and culture are for the benefit of final users.

  16. Four Argentine crudes in world market

    SciTech Connect

    Aalund, L.R.

    1995-04-17

    The deregulation of Argentina`s oil industry and the privatization of its state-owned oil company are putting more of the country`s crude oil into the international oil market. Analyses, furnished by YPF, of the four major export crudes--Rincon de los Sauces, Canadon Seco, Medanito, and Escalante--are given in this article. Also presented are true boiling point curves for all except Canadon Seco. The producing areas and supply systems for moving these crude to shipping terminals were described in OGJ, Feb. 13, pp. 50--52. Information is given on the shipping facilities for the crudes.

  17. Bechtel team to study Argentine oil complex

    SciTech Connect

    Not Available

    1993-08-23

    A US joint venture has won a contract for a feasibility study that could lead to a $1-billion petrochemical complex in Argentina. Bechtel International Inc., San Francisco, is teamed with Chem Systems, New York City, on the $430,000 study. Under contract with the Province of Neuquen's Counsel for Planning and Development and the US Trade and Development Agency, the consultant will evaluate the economic, financial and environmental feasibility of the proposed project, conduct a market analysis and advise on site selection. The study is expected in six months. Bechtel and Chem Systems will explore the feasibility of extracting liquids from natural gas and transporting them by pipeline from the province's extensive gas fields.

  18. The Argentine regulators framework: A new approach

    SciTech Connect

    Garcia, R.

    1993-12-31

    Three aspects of the economic reorganization implemented by the government of Argentina are described. These include privatization, the regulatory framework, and the regulatory agency. On the privatizations undertaken by the Argentina government have as their main goals the increase in efficiency, to promote investment, and to separate economic from political aspects.

  19. Sign Order in Argentine Sign Language

    ERIC Educational Resources Information Center

    Massone, Maria Ignacia; Curiel, Monica

    2004-01-01

    This article focuses on word order - the order of constituents in the sentence - as one way in which languages establish the relationship between a verb and its arguments. The spoken languages of the world have been classified into three, major word-order types: SVO, VSO, and SOV. Greenberg' work (1963) on language typology has been a stimulus to…

  20. Les langues sur le gril argentin (Languages on the Argentine Grill).

    ERIC Educational Resources Information Center

    Cagnolait, Beatriz

    1994-01-01

    A survey of secondary students, French language teachers, managers, and university students in Buenos Aires (Argentina) gives insight into the role of French there and reasons for studying it. Students in general appreciated the language for its aesthetic aspects, managers and teachers for its contribution to culture in general. (MSE)

  1. Acoustical Scattering, Propagation, and Attenuation Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake

    DTIC Science & Technology

    2014-09-30

    Oceanography Admin Bldg Oregon State University Corvallis, OR 97331-5503 phone: (541) 737-2063 fax: (541) 737-2064 email: kbenoit...NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Oregon State...Catherine T. MacArthur Foundation 2011 Ocean Sciences Meeting Plenary Speaker 2012 PopTech Science Fellow 11 2012 Oregon State University Promising

  2. Acoustical Scattering, Propagation, and Attenuation Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake

    DTIC Science & Technology

    2013-09-30

    larval fish and squid, and gelatinous zooplankton ). Two manuscripts detailing these results are undergoing internal revision and are planned to be...primarily different zooplankton species. Zooplankton density contrast values varied both within and among different species (Figure 5) as well as for...different zooplankton taxa. The lower line of each box represents the 1st quartile, the middle bolded line represents the median, and the top line of the box

  3. 77 FR 72242 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; White Hake Trimester...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    ... fishing with trawl gear, sink gillnet gear, or longline/hook gear for the remainder of Trimester 2... common pool vessels fishing with trawl, sink gillnet, and longline/hook gear at the beginning of... NE multispecies fishery are found at 50 CFR part 648, subpart F. Beginning in fishing year (FY) 2012...

  4. Alkylphenols and alkylphenol ethoxylates contamination of crustaceans and fishes from the Adriatic Sea (Italy).

    PubMed

    Ferrara, Fulvio; Fabietti, Fabio; Delise, Mirella; Funari, Enzo

    2005-05-01

    This paper presents the results of an investigation on the occurrence of alkylphenols (APs) and their ethoxylates (APEs) in 8 edible marine species from the Adriatic Sea and tries to estimate the corresponding intake for the Italian population. Two crustaceans, Nephrops norvegicus (Norway lobster) and Squilla mantis (spottail mantis shrimp), plus six fish species, Engraulis enchrascicolus (anchovy), Scomber scombrus (Atlantic mackerel), Merluccius merluccius (European hake), Mullus barbatus (red mullet), Solea vulgaris (common sole) and Lophius piscatorius (angler) were analyzed for their content of nonylphenol (NP), octylphenol (OP) and octylphenol polyethoxylates (OPEs). These compounds were found in all analysed samples. NP was detected at the highest concentrations: 118-399 and 9.5-1431 ng g(-1) fresh weight (fw) respectively in crustaceans and fish. OP was found at respective levels of 2.7-4.7 and 0.3-3.8 ng g(-1) fw in crustaceans and fish, whereas OPE was determined at respective concentrations of 1.2-16.8 and 0.2-21.1 ng g(-1) fw in the same species. These results, together with those from a previous study on 4 edible mollusc, allow to estimate respective daily intakes for NP, OP, and OPE of about 12, 0.1, and 0.1 microg day(-1) for an Italian adult living along the Adriatic Coast. In relation to NP and OP, these intakes are much lower than the doses associated with toxic effects in laboratory animals (9 mg kg(-1) bw for rats). Nevertheless, data of exposure from other sources to these chemicals and others with similar biological characteristics are needed.

  5. Gap analysis on the biology of Mediterranean marine fishes.

    PubMed

    Dimarchopoulou, Donna; Stergiou, Konstantinos I; Tsikliras, Athanassios C

    2017-01-01

    We estimated the current level of knowledge concerning several biological characteristics of the Mediterranean marine fishes by carrying out a gap analysis based on information extracted from the literature, aiming to identify research trends and future needs in the field of Mediterranean fish biology that can be used in stock assessments, ecosystem modeling and fisheries management. Based on the datasets that emerged from the literature review, there is no information on any biological characteristic for 43% (n = 310) of the Mediterranean fish species, whereas for an additional 15% (n = 109) of them there is information about just one characteristic. The gap between current and desired knowledge (defined here as having information on most biological characteristics for at least half of the Mediterranean marine fishes) is smaller in length-weight relationships, which have been studied for 43% of the species, followed by spawning (39%), diet (29%), growth (25%), maturity (24%), lifespan (19%) and fecundity (17%). The gap is larger in natural mortality for which information is very scarce (8%). European hake (Merluccius merluccius), red mullet (Mullus barbatus), annular seabream (Diplodus annularis), common pandora (Pagellus erythrinus), European anchovy (Engraulis encrasicolus), European pilchard (Sardina pilchardus) and bogue (Boops boops) were the most studied species, while sharks and rays were among the least studied ones. Only 25 species were fully studied, i.e. there was available information on all their biological characteristics. The knowledge gaps per characteristic varied among the western, central and eastern Mediterranean subregions. The number of available records per species was positively related to total landings, while no relationship emerged with its maximum reported length, trophic level and commercial value. Future research priorities that should be focused on less studied species (e.g. sharks and rays) and mortality/fecundity instead of length

  6. Gap analysis on the biology of Mediterranean marine fishes

    PubMed Central

    Dimarchopoulou, Donna; Stergiou, Konstantinos I.

    2017-01-01

    We estimated the current level of knowledge concerning several biological characteristics of the Mediterranean marine fishes by carrying out a gap analysis based on information extracted from the literature, aiming to identify research trends and future needs in the field of Mediterranean fish biology that can be used in stock assessments, ecosystem modeling and fisheries management. Based on the datasets that emerged from the literature review, there is no information on any biological characteristic for 43% (n = 310) of the Mediterranean fish species, whereas for an additional 15% (n = 109) of them there is information about just one characteristic. The gap between current and desired knowledge (defined here as having information on most biological characteristics for at least half of the Mediterranean marine fishes) is smaller in length-weight relationships, which have been studied for 43% of the species, followed by spawning (39%), diet (29%), growth (25%), maturity (24%), lifespan (19%) and fecundity (17%). The gap is larger in natural mortality for which information is very scarce (8%). European hake (Merluccius merluccius), red mullet (Mullus barbatus), annular seabream (Diplodus annularis), common pandora (Pagellus erythrinus), European anchovy (Engraulis encrasicolus), European pilchard (Sardina pilchardus) and bogue (Boops boops) were the most studied species, while sharks and rays were among the least studied ones. Only 25 species were fully studied, i.e. there was available information on all their biological characteristics. The knowledge gaps per characteristic varied among the western, central and eastern Mediterranean subregions. The number of available records per species was positively related to total landings, while no relationship emerged with its maximum reported length, trophic level and commercial value. Future research priorities that should be focused on less studied species (e.g. sharks and rays) and mortality/fecundity instead of length

  7. Feeding strategies and ecological roles of three predatory pelagic fish in the western Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Navarro, Joan; Sáez-Liante, Raquel; Albo-Puigserver, Marta; Coll, Marta; Palomera, Isabel

    2017-06-01

    Knowing the feeding ecology of marine predators is pivotal to developing an understanding of their ecological role in the ecosystem and determining the trophic relationships between them. Despite the ecological importance of predatory pelagic fish species, research on these species in the Mediterranean Sea is limited. Here, by combining analyses of stomach contents and stable isotope values, we examined the feeding strategies of swordfish, Xiphias gladius, little tunny, Euthynnus alletteratus and Atlantic bonito, Sarda sarda, in the western Mediterranean Sea. We also compared the trophic niche and trophic level of these species with published information of other sympatric pelagic predators present in the ecosystem. Results indicated that, although the diet of the three species was composed mainly by fin-fish species, a clear segregation in their main feeding strategies was found. Swordfish showed a generalist diet including demersal species such as blue whiting, Micromesistius poutassou, and European hake, Merluccius merluccius, and pelagic fin-fish such as barracudina species (Arctozenus risso and Lestidiops jayakari) or small pelagic fish species. Little tunny and Atlantic bonito were segregated isotopically between them and showed a diet basically composed of anchovy, Engraulis encrasicolus, and round sardinella, Sardinella aurita, and sardines, Sardina pilchardus, respectively. This trophic segregation, in addition to potential segregation by depth, is likely a mechanism that allows their potential coexistence within the same pelagic habitat. When the trophic position of these three predatory pelagic fish species is compared with other pelagic predators such as bluefin tuna, Thunnus thynnus, and dolphinfish, Coryphaena hippurus, present in the western Mediterranean Sea, we found that they show similar intermediate trophic position in the ecosystem. In conclusion, the combined stomach and isotopic results highlight, especially for little tunny and Atlantic

  8. Food web and fish stock changes in central Chile: comparing the roles of jumbo squid (Dosidicus gigas) predation, the environment, and fisheries

    NASA Astrophysics Data System (ADS)

    Neira, Sergio; Arancibia, Hugo

    2013-10-01

    We analyzed recent food web and fish stock changes in the central Chile marine ecosystem, comparing the roles of jumbo squid (Dosidicus gigas) as predator, the environment, and fishing. To accomplish this we used food web modeling and the Ecopath with Ecosim software (EwE). The principal fish stocks have experienced wide decadal fluctuations in the past 30 years, including stock collapses of horse mackerel (Trachurus murphyi) and hake (Merluccius gayi), and there was a large influx of jumbo squid during the mid-2000s. We used two EwE models representing the food web off central Chile to test the hypothesis that predation by jumbo squid has been significant in explaining the dynamics of the main fishing resources and other species in the study area. Results indicate that predation by jumbo squid on fish stocks is lower than that of other predators (e.g. hake) and the fishery. Long-term fluctuations (1978-2004) in the biomass of the main fish stocks (as well as other components of the food web) seem to be related to fishing and to variation in primary production, rather than to predation by jumbo squid alone. Jumbo squid seems to play a role as predator rather than prey in the system, but its impacts are low when compared with the impacts of other predators and fishing. Therefore, we conclude that jumbo squid predation on its prey was not the primary force behind the collapse of important fish stocks off central Chile. Future efforts should be directed to better understanding factors that trigger sudden increases in jumbo squid abundance off central Chile, as well as modeling its trophic impacts.

  9. Biases in determining the diet of jumbo squid Dosidicus gigas (D' Orbigny 1835) (Cephalopoda: Ommastrephidae) off southern-central Chile (34°S-40°S)

    NASA Astrophysics Data System (ADS)

    Ibáñez, Christian M.; Arancibia, Hugo; Cubillos, Luis A.

    2008-12-01

    The diet of jumbo squid ( Dosidicus gigas) off southern-central Chile is described to examine potential biases in the determination of their main prey. Specimens were collected from catches using different fishing gear (jigging, trawl and purse-seine), from July 2003 to January 2004, and from December 2005 to October 2006. The stomach contents were analyzed in terms of frequency of occurrence, number, and weight of prey items and the diet composition was analyzed using Detrended Correspondence Analysis. In the industrial purse-seine fleet for jack mackerel ( Trachurus murphyi), the dominant prey of D. gigas was T. murphyi. In the industrial mid-trawl fishery for Patagonian grenadier ( Macruronus magellanicus), the dominant species in the diet of D. gigas was M. magellanicus. Similarly, Chilean hake ( Merluccius gayi) was the main prey in the diet of D. gigas obtained in the industrial trawl fishery for Chilean hake; and, in both artisanal fisheries (purse-seine for small pelagics and jigging), small pelagic fish and D. gigas were the main prey in the stomach contents of D. gigas. Cannibalism in D. gigas varied between different fleets and probably is related to stress behavior during fishing. The Detrended Correspondence Analysis ordination showed that the main prey in the diet of D. gigas is associated with the target species of the respective fishery. Consequently, biases are associated with fishing gear, leading to an overestimate in the occurrence of the target species in the diet. We recommend analyzing samples from jigging taken at the same time and place where the trawl and purse-seine fleets are operating to avoid this problem, and the application of new tools like stable isotope, heavy metal, and fatty acid signature analyses.

  10. Material properties of zooplankton and nekton from the California current

    NASA Astrophysics Data System (ADS)

    Becker, Kaylyn

    This study measured the material properties of zooplankton, Pacific hake (Merluccius productus), Humboldt squid (Dosidicus gigas), and two species of myctophids (Symbolophorus californiensis and Diaphus theta) collected from the California Current ecosystem. The density contrast (g) was measured for euphausiids, decapods (Sergestes similis), amphipods (Primno macropa, Phronima sp., and Hyperiid spp.), siphonophore bracts, chaetognaths, larval fish, crab megalopae, larval squid, and medusae. Morphometric data (length, width, and height) were collected for these taxa. Density contrasts varied within and between zooplankton taxa. The mean and standard deviation for euphausiid density contrast were 1.059 +/- 0.009. Relationships between zooplankton density contrast and morphometric measurements, geographic location, and environmental conditions were investigated. Site had a significant effect on euphausiid density contrast. Density contrasts of euphausiids collected in the same geographic area approximately 4-10 days apart were significantly higher (p < 0.001). Sound speed contrast (h) was measured for euphausiids and pelagic decapods (S. similis) and it varied between taxa. The mean and standard deviation for euphausiid sound speed were 1.019 +/- 0.009. Euphausiid mass was calculated from density measurements and volume, and a relationship between euphausiid mass and length was produced. We determined that euphausiid from volumes could be accurately estimated two dimensional measurements of animal body shape, and that biomass (or biovolume) could be accurately calculated from digital photographs of animals. Density contrast (g) was measured for zooplankton, pieces of hake flesh, myctophid flesh, and of the following Humboldt squid body parts: mantle, arms, tentacle, braincase, eyes, pen, and beak. The density contrasts varied within and between fish taxa, as well as among squid body parts. Effects of animal length and environmental conditions on nekton density

  11. Benzo[a]pyrene and Benzo[k]fluoranthene in Some Processed Fish and Fish Products

    PubMed Central

    Olatunji, Olatunde S.; Fatoki, Olalekan S.; Opeolu, Beatrice O.; Ximba, Bhekumusa J.

    2015-01-01

    In this study, the concentration levels of the probable carcinogenic PAH fractions, benzo[a]pyrene (BaP) and benzo[k]fluoranthrene (BkF) in fillets of some processed fish species were investigated. Fish species comprising Merluccius poli (hake), Tyrsites atun (snoek), Seriola lalandi (yellow-tail) and Brama brama (angel fish) were bought in fish shops at Gordon’s Bay, Western Cape, South Africa. The fish were gutted, filleted and prepared for edibility by frying, grilling and boiling. Polycyclic aromatic hydrocarbons were extracted from each homogenized fish sample, cleaned-up using solid phase extraction (SPE), and analysed for the PAH fractions, BaP and BkF using a Gas Chromatograph coupled with a Flame Ionization Detector (GC-FID). The sum of the two PAHs (∑2PAH) i.e., BaP and BkF ranged between 0.56 and 1.46 µg/kg, in all boiled, grilled and fried fish species. The fried fish extracts showed significantly higher (p < 0.05) abundance of ∑2PAH, than grilled and boiled fish. Dietary safety and PAHs toxicity was also discussed. PMID:25607603

  12. Seafloor habitat mapping of the New York Bight incorporating sidescan sonar data

    USGS Publications Warehouse

    Lathrop, R.G.; Cole, M.; Senyk, N.; Butman, B.

    2006-01-01

    The efficacy of using sidescan sonar imagery, image classification algorithms and geographic information system (GIS) techniques to characterize the seafloor bottom of the New York Bight were assessed. The resulting seafloor bottom type map was compared with fish trawl survey data to determine whether there were any discernable habitat associations. An unsupervised classification with 20 spectral classes was produced using the sidescan sonar imagery, bathymetry and secondarily derived spatial heterogeneity to characterize homogenous regions within the study area. The spectral classes, geologic interpretations of the study region, bathymetry and a bottom landform index were used to produce a seafloor bottom type map of 9 different bottom types. Examination of sediment sample data by bottom type indicated that each bottom type class had a distinct composition of sediments. Analysis of adult summer flounder, Paralichthys dentatus, and adult silver hake, Merluccius bilinearis, presence/absence data from trawl surveys did not show evidence of strong associations between the species distributions and seafloor bottom type. However, the absence of strong habitat associations may be more attributable to the coarse scale and geographic uncertainty of the trawl sampling data than conclusive evidence that no habitat associations exist for these two species. ?? 2006 Elsevier Ltd. All rights reserved.

  13. Effect of processing conditions on trace elements in fish roe from six commercial new zealand fish species.

    PubMed

    Bekhit, Alaa El-Din A; Morton, James D; Dawson, Chris O

    2008-06-25

    The concentrations of trace elements in fish roes and the effect of processing conditions (karasumi-like or karashi mentaiko) were investigated in six commercial fish species from New Zealand. The studied elements were As, Cd, Cr, Cu, Hg, Pb, and Zn, and the roes were from the following species: chinook salmon ( Oncorhynchus tshawytscha), hoki ( Macruronus novaezelandiae), southern blue whiting ( Micromesistius australis), hake ( Merluccius australis), blue warehou ( Seriolella brama), and barracouta ( Thyrsites atun). The concentrations of As, Cd, Cr, Hg, and Pb in the roes were lower than literature values for fish muscles. Only Zn in barracouta roe and Cu in salmon roe and their products were relatively higher than the generally accepted levels in fish muscles and could be of safety concern. Hence, the consumption of barracouta and salmon roes among certain parts of the population needs to be monitored and assessed. Dry salting (karasumi-like) processing increased ( P < 0.001) the concentrations of the studied trace elements while salting fermentation (karashi mentaiko) processing tended to decrease the levels of trace elements. Fermentation may be a useful process to decrease the level of toxic trace elements.

  14. Epidemiology of enteric adenovirus infection in prospectively monitored Argentine families.

    PubMed Central

    Mistchenko, A. S.; Huberman, K. H.; Gomez, J. A.; Grinstein, S.

    1992-01-01

    To examine the role of enteric adenoviruses (EAV) in an urban area of Buenos Aires (Argentina), we prospectively studied faecal samples from 49 families of newborns. These were monitored weekly for diarrhoea for 2 years. A total of 180 samples from cases of diarrhoea and 766 samples obtained during diarrhoea-free periods were studied by dot-blot hybridization with an EAV-specific DNA probe. EAV were found in 6/180 (3.3%) cases of diarrhoea and 6/766 (0.8%) asymptomatic samples (P < 0.015). Incidence of EAV was 3.9 cases per 100 person-years in children < 60 months old. EAV-related diarrhoeas were slight and of short duration. In addition, 129 faeces from hospital out-patients, 1-30 months old, were also studied. EAV was identified in 7/129 cases (5.4%). These cases were 9.5 +/- 3.5 months old and the diarrhoea was mild or severe, of 3 +/- 1.5 days of duration. We suggest that EAV are low-risk causes of diarrhoea under natural conditions, although a few children may develop more severe diarrhoea. The diagnosis of EAV needs to be considered in these patients. PMID:1468536

  15. Extremist Media and the Rise of Terrorism: The Argentine Case.

    ERIC Educational Resources Information Center

    Day, J. Laurence

    In the 20 months that Isabel Peron served as the first female chief of state of a South American country, the mass media in Argentina underwent extreme stress. The Montoneros, a militant leftist organization, called for mass demonstrations against the orthodox Peronist people in their tabloid "La Causa Peronista." The tabloid's…

  16. Education for Citizenship: The Argentine Case in Comparison

    ERIC Educational Resources Information Center

    Astiz, M. Fernanda; Mendez, Gabriela

    2006-01-01

    This article considers how Argentina produces its citizens following its transition to democracy in the early 1980s. We ask how the schooling system is preparing the next generation to participate in the democratic political process, and the responsibilities of nation building in a world that has become more politically and economically entangled.…

  17. Extremist Media and the Rise of Terrorism: The Argentine Case.

    ERIC Educational Resources Information Center

    Day, J. Laurence

    In the 20 months that Isabel Peron served as the first female chief of state of a South American country, the mass media in Argentina underwent extreme stress. The Montoneros, a militant leftist organization, called for mass demonstrations against the orthodox Peronist people in their tabloid "La Causa Peronista." The tabloid's…

  18. [Epidemiological status of mycoses in the Argentine Republic].

    PubMed

    Davel, G; Canteros, C E

    2007-01-01

    We herein report the results of a retrospective nationwide survey on mycoses diagnosed between January and December, 2004. The study included data provided by 72 laboratories located in 19 provinces and in Buenos Aires City. Out of 801,805 microbiological specimens processed that year, only 62,681 (8%) were submitted to mycological studies. A total of 23,600 mycoses cases were diagnosed: 11,107 (47%) superficial mycoses, 10,830 (46%) mucosal candidiasis and 1,663 (7%) deep mycoses. Relative frequencies of superficial mycoses did not differ significantly (p > 0.05) from frequencies observed in a previous study covering Buenos Aires City and Province (1993), and from two countrywide surveys conducted by the National Network of Mycology Laboratories and National Quality Control Program (NNML and NQCP) in 1999 and 2002. The most frequent deep mycoses were yeast fungaemia (34%), cryptococcosis (20%), broncho-pulmonary aspergillosis (13%), histoplasmosis (11%), paracoccidioidomycosis (7%) and pneumocystosis (5%). In contrast with results of four previous nationwide studies on broncho-pulmonary mycoses including a survey performed by NNML and NQCP in 2002, our study revealed that histoplasmosis prevailed over paracoccidioidomycosis, thus ranking for the first time as the most frequent endemic mycosis in Argentina.

  19. Quaternary Glaciations in the Rio Mendoza Valley, Argentine Andes

    NASA Astrophysics Data System (ADS)

    Espizua, Lydia E.

    1993-09-01

    In the Rio Mendoza valley, five Pleistocene drifts and one