Sample records for ratsnake elaphe obsoleta

  1. Use of trees by the Texas ratsnake (Elaphe obsoleta) in eastern Texas (United States)

    Josh B. Pierce; Robert R. Fleet; Lance McBrayer; D. Craig Rudolph


    We present information on the use of trees by Elaphe obsoleta (Texas Ratsnake) in a mesic pine-hardwood forest in eastern Texas. Using radiotelemetry, seven snakes (3 females, 4 males) were relocated a total of 363 times from April 2004 to May 2005, resulting in 201 unique locations. Snakes selected trees containing cavities and used hardwoods and...

  2. Latitudinal variation in seasonal activity and mortality in ratsnakes (Elaphe obsoleta). (United States)

    Sperry, Jinelle H; Blouin-Demers, Gabriel; Carfagno, Gerardo L F; Weatherhead, Patrick J


    The ecology of ectotherms should be particularly affected by latitude because so much of their biology is temperature dependent. Current latitudinal patterns should also be informative about how ectotherms will have to modify their behavior in response to climate change. We used data from a total of 175 adult black ratsnakes (Elaphe obsoleta) radio-tracked in Ontario, Illinois, and Texas, a latitudinal distance of >1500 km, to test predictions about how seasonal patterns of activity and mortality should vary with latitude. Despite pronounced differences in temperatures among study locations, and despite ratsnakes in Texas not hibernating and switching from diurnal to nocturnal activity in the summer, seasonal patterns of snake activity were remarkably similar during the months that snakes in all populations were active. Rather than being a function of temperature, activity may be driven by the timing of reproduction, which appears similar among populations. Contrary to the prediction that mortality should be highest in the most active population, overall mortality did not follow a clinal pattern. Winter mortality did increase with latitude, however, consistent with temperature limiting the northern distribution of ratsnakes. This result was opposite that found in the only previous study of latitudinal variation in winter mortality in reptiles, which may be a consequence of whether or not the animals exhibit true hibernation. Collectively, these results suggest that, at least in the northern part of their range, ratsnakes should be able to adjust easily to, and may benefit from, a warmer climate, although climate-based changes to the snakes' prey or habitat, for example, could alter that prediction.

  3. Taxonomy Icon Data: Japanese Ratsnake [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Japanese Ratsnake Elaphe climacophora Chordata/Vertebrata/Reptilia/etc Elaphe_climacophora_L.png Elaphe_clim...acophora_NL.png Elaphe_climacophora_S.png Elaphe_climacophora_NS.png ...

  4. Experimentally reducing clutch size reveals a fixed upper limit to egg size in snakes, evidence from the king ratsnake, Elaphe carinata. (United States)

    Ji, Xiang; Du, Wei-Guo; Li, Hong; Lin, Long-Hui


    Snakes are free of the pelvic girdle's constraint on maximum offspring size, and therefore present an opportunity to investigate the upper limit to offspring size without the limit imposed by the pelvic girdle dimension. We used the king ratsnake (Elaphe carinata) as a model animal to examine whether follicle ablation may result in enlargement of egg size in snakes and, if so, whether there is a fixed upper limit to egg size. Females with small sized yolking follicles were assigned to three manipulated, one sham-manipulated and one control treatments in mid-May, and two, four or six yolking follicles in the manipulated females were then ablated. Females undergoing follicle ablation produced fewer, but larger as well as more elongated, eggs than control females primarily by increasing egg length. This finding suggests that follicle ablation may result in enlargement of egg size in E. carinata. Mean values for egg width remained almost unchanged across the five treatments, suggesting that egg width is more likely to be shaped by the morphological feature of the oviduct. Clutch mass dropped dramatically in four- and six-follicle ablated females. The function describing the relationship between size and number of eggs reveals that egg size increases with decreasing clutch size at an ever-decreasing rate, with the tangent slope of the function for the six-follicle ablation treatment being -0.04. According to the function describing instantaneous variation in tangent slope, the maximum value of tangent slope should converge towards zero. This result provides evidence that there is a fixed upper limit to egg size in E. carinata.

  5. First report of Hepatozoon (Apicomplexa: Adeleorina) from king ratsnakes (Elaphe carinata) in Shanghai, with description of a new species. (United States)

    Han, Hongyu; Wu, Youling; Dong, Hui; Zhu, Shunhai; Li, Liujia; Zhao, Qiping; Wu, Di; Pei, Enle; Wang, Yange; Huang, Bing


    Hepatozoon species are the most common hemoparasites of snakes. In this study, Hepatozoon parasites were examined for the first time in king rat snakes (Elaphe carinata) from Shanghai, China. All 10 snakes were found to be infected with Hepatozoon gamonts. The gamonts were folded back in a hook-wise fashion for about 3 μm at one end. Parasitemia levels ranged from 4-43 infected erythrocytes per 1,000 examined. The gamonts changed the morphology of the parasitized erythrocytes. Although the gamonts showed some distinct variations in both the parasite and its nucleus, phylogenetic analysis indicated that all the E. carinata in this study formed a monophyletic group, and were distinct from all other published Hepatozoon species. A new species, Hepatozoon chinensis, was proposed based on the molecular and morphologic evidence.

  6. Texas ratsnake predation on southern flying squirrels in red-cockaded woodpecker cavities (United States)

    D. Craig Rudolph; Richard R. Schaefer; Josh B. Pierce; Dan Saenz; Richard N. Conner


    Elaphe spp. (ratsnakes) are frequent predators on cavity-nesting birds and other vertebrates, including Glaucomys volans (Southern Flying Squirrels). They are known predators of Picoides borealis (Red-cockaded Woodpeckers), especially during the nestling phase. Picoides borealis cavities are frequently occupied by Southern Flying Squirrels, often several squirrels per...

  7. Using phylogenomics to understand the link between biogeographic origins and regional diversification in ratsnakes. (United States)

    Chen, Xin; Lemmon, Alan R; Lemmon, Emily Moriarty; Pyron, R Alexander; Burbrink, Frank T


    Globally distributed groups may show regionally distinct rates of diversification, where speciation is elevated given timing and sources of ecological opportunity. However, for most organisms, nearly complete sampling at genomic-data scales to reduce topological error in all regions is unattainable, thus hampering conclusions related to biogeographic origins and rates of diversification. We explore processes leading to the diversity of global ratsnakes and test several important hypotheses related to areas of origin and enhanced diversification upon colonizing new continents. We estimate species trees inferred from phylogenomic scale data (304 loci) while exploring several strategies that consider topological error from each individual gene tree. With a dated species tree, we examine taxonomy and test previous hypotheses that suggest the ratsnakes originated in the Old World (OW) and dispersed to New World (NW). Furthermore, we determine if dispersal to the NW represented a source of ecological opportunity, which should show elevated rates of species diversification. We show that ratsnakes originated in the OW during the mid-Oligocene and subsequently dispersed to the NW by the mid-Miocene; diversification was also elevated in a subclade of NW taxa. Finally, the optimal biogeographic region-dependent speciation model shows that the uptick in ratsnake diversification was associated with colonization of the NW. We consider several alternative explanations that account for regionally distinct diversification rates. Copyright © 2017 Elsevier Inc. All rights reserved.


    The Biocide Tributyltin Alters Testosterone Esterification in Mud Snails (Ilyanassa obsoleta)Meredith P. Gooding and Gerald A. LeBlanc Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, NC 27695-7633Tributyltin (TBT...

  9. Ratsnake: A Versatile Image Annotation Tool with Application to Computer-Aided Diagnosis

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    D. K. Iakovidis


    Full Text Available Image segmentation and annotation are key components of image-based medical computer-aided diagnosis (CAD systems. In this paper we present Ratsnake, a publicly available generic image annotation tool providing annotation efficiency, semantic awareness, versatility, and extensibility, features that can be exploited to transform it into an effective CAD system. In order to demonstrate this unique capability, we present its novel application for the evaluation and quantification of salient objects and structures of interest in kidney biopsy images. Accurate annotation identifying and quantifying such structures in microscopy images can provide an estimation of pathogenesis in obstructive nephropathy, which is a rather common disease with severe implication in children and infants. However a tool for detecting and quantifying the disease is not yet available. A machine learning-based approach, which utilizes prior domain knowledge and textural image features, is considered for the generation of an image force field customizing the presented tool for automatic evaluation of kidney biopsy images. The experimental evaluation of the proposed application of Ratsnake demonstrates its efficiency and effectiveness and promises its wide applicability across a variety of medical imaging domains.

  10. Four additional hepatozoon species (Apicomplexa: Hepatozoidae) from north Florida ratsnakes, genus Pantherophis. (United States)

    Telford, Sam R; Moler, Paul E; Butler, Jerry F


    Records from a colubrid host are reported for Hepatozoon horridus, described originally from a viperid snake. Hepatozoon horridus in Pantherophis guttatus (Colubridae) has gamonts 14-18.0 by 4.0-5.5 microm, with length by width (LW) 60-99 microm2, and L/W ratio 2.5-3.9. Spherical to elongate, usually ovoid oocysts with L/W ratio 1.0-3.7 contain 16-160 spherical to usually ovoid sporocysts 15-31 by 14-26 microm, with L/W ratio 1.0-1.4, that contain 5-24 sporozoites. Two additional Hepatozoon species are described from ratsnakes in north Florida. Hepatozoon quadrivittata n. sp. from Pantherophis obsoletus quadrivittatus has gamonts 12-17 by 4-6 microm, LW 56-102 microm2, and L/W ratio 2.6-3.8. Nearly spherical oocysts with L/W 1.0-1.1 contain 5-227 spherical to slightly ovoid sporocysts 20-48 by 19-45 microm, with L/W ratio 1.0-1.4, that contain 13-48 sporozoites. Hepatozoon spiloides n. sp. from Pantherophis obsoletus spiloides forms gamonts 12-15 by 4-5 microm with LW 48-75 microm2 and L/W ratio 2.6-3.5. Occasionally rounded but usually elongate oocysts, with L/W ratio 1.0-2.7, contain 5-21 spherical to elongate sporocysts 28-43 by 18-35 microm, L/W ratio 2.5-3.9. In the distinctive Hepatozoon sp. present in Pantherophis obsoletus spiloides, gamonts are 13-17 by 5-10 microm, with LW 75-140 microm2 and L/W ratio 1.4-3.0. Infected erythrocytes are always distorted and enlarged on average 2.5 times the size of uninfected cells, with nuclei enlarged by one-third and broadly elongated. Gamonts often stained deep blue, and cytoplasm of erythrocytes infected with mature gamonts was always dehemoglobinized. Sporogony could not be obtained in three feedings by hundreds of Aedes aegypti, which usually died within the first 24-48 hr.

  11. Proteomic profiling of liver from Elaphe taeniura, a common snake in eastern and southeastern Asia

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    Liang Chen


    Full Text Available Snake liver has been implicated in the adaptation of snakes to a variety of habitats. However, to date, there has been no systematic analysis of snake liver proteins. In this study, we undertook a proteomic analysis of liver from the colubrid snake Elaphe taeniura using a combination of two-dimensional electrophoresis (2-DE and matrix-assisted laser desorption/ionization time of flightmass spectrometry (MALDI-TOF MS. We also constructed a local protein sequence database based on transcriptome sequencing to facilitate protein identification. Of the 268 protein spots revealed by 2-DE 109 gave positive MS signals, 84 of which were identified by searching the NCBInr, Swiss-Prot and local databases. The other 25 protein spots could not be identified, possibly because their transcripts were not be stable enough to be detected by transcriptome sequencing. GO analysis showed that most proteins may be involved in binding, catalysis, cellular processes and metabolic processes. Forty-two of the liver proteins identified were found in other reptiles and in amphibians. The findings of this study provide a good reference map of snake liver proteins that will be useful in molecular investigations of snake physiology and adaptation.

  12. A preliminary investigations on infective parasites in King rat snakes(Elaphe carinata and Red-banded wolf snakes(Dinodon rufozonatum in Shanghai

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    WU Youling


    Full Text Available To investigate the infective status of parasites in snakes from Shanghai,19 snakes from 2 species ( 9 Dinodon rufozonatum and 10 Elaphe carinata confiscated from the market were dissected.The viscera (body,subcutaneous,muscles,heart,lungs,liver,stomach,intestinal organs and blood smears of the snakes were examined.The parasites from these viscera were collected and observed by microscope.The results showed nematodes,tapeworms and Hepatozoon were found,but no ectoparasites,trematodes and acanthocephalan.The parasitic infection rate of snakes checked was 100%.The infection rate of nematodes,tapeworms and Hepatozoon were 77.88%,100%,0 in Dinodon rufozonatum and 100%,100%,100% in Elaphe carinata, respectively.A total of 192 nematodes and 1236 tapeworms were collected in 19 snakes,and 69.79% of nematodes and 86.55% of tapeworms were from Elaphe carinata.According to the viscera,93.20% of tapeworms were found in subcutaneous and 65.63% of nematodes in stomach.The results indicated the parasitic infection rate and intensity of snakes from Shanghai market were very high.Sparganum mansoni found in this investigation was zoonotic parasite,and it is easy to infect humans through eating snake skin,meat and gall.Therefore,protecting wild animals like snakes is also to protect human themselves.

  13. Genomic and phylogenetic analyses of an adenovirus isolated from a corn snake (Elaphe guttata) imply a common origin with members of the proposed new genus Atadenovirus. (United States)

    Farkas, Szilvia L; Benko, Mária; Elo, Péter; Ursu, Krisztina; Dán, Adám; Ahne, Winfried; Harrach, Balázs


    Approximately 60% of the genome of an adenovirus isolated from a corn snake (Elaphe guttata) was cloned and sequenced. The results of homology searches showed that the genes of the corn snake adenovirus (SnAdV-1) were closest to their counterparts in members of the recently proposed new genus ATADENOVIRUS: In phylogenetic analyses of the complete hexon and protease genes, SnAdV-1 indeed clustered together with the atadenoviruses. The characteristic features in the genome organization of SnAdV-1 included the presence of a gene homologous to that for protein p32K, the lack of structural proteins V and IX and the absence of homologues of the E1A and E3 regions. These characteristics are in accordance with the genus-defining markers of atadenoviruses. Comparison of the cleavage sites of the viral protease in core protein pVII also confirmed SnAdV-1 as a candidate member of the genus ATADENOVIRUS: Thus, the hypothesis on the possible reptilian origin of atadenoviruses (Harrach, Acta Veterinaria Hungarica 48, 484-490, 2000) seems to be supported. However, the base composition of DNA sequence (>18 kb) determined from the SnAdV-1 genome showed an equilibrated GC content of 51%, which is unusual for an atadenovirus.

  14. ¿Huelgas y luchas obsoletas?

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    José Eduardo Rueda Enciso


    Full Text Available Petróleo y protesta obrera. La uso y los trabajadores petroleros en Colombia (1923-2008 En tiempos de la Tropical (t. 1, En tiempos de Ecopetrol (t. 2. Renán Vega Cantor, Luz Ángela Núñez Espinel y Alexander Pereira FernándezCorporación Aury Sará Marrugo, 2009, Bogotá, 413 y 492 págs.

  15. Nuestra obsoleta mentalidad de mercado Our obsolete market mentality

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    Polanyi Karl


    Full Text Available Karl Polanyi es poco conocido entre los economistas, aunque sea muy influyente en otras disciplinas. El derrumbamiento de los regímenes orientales de Europa Oriental ha renovado el interés en sus trabajos: ante todo entre quienes intentan justificar la ineficiencia económica de los regímenes totalitarios, apoyan el restablecimiento de los derechos humanos y buscan que los gobiernos sean responsables ante los ciudadanos, sin confiar críticamente sobre las fuerzas de mercado. Su obra empieza a ser consultada por quienes buscan alternativas para modernizar las sociedades latinoamericanas sin olvidar las complejas necesidades del ser humano. Las tradiciones liberales son insuficientes aquí y allá: no se pueden abandonar las libertades individuales, pero éstas deben ser recreadas; no se puede restaurar un sistema social obsoleto, cuyos males oculta la bruma de la ideología; la sociedad debe reconstruirse aprendiendo las lecciones que somos capaces de aprender; por ejemplo, que la motivaciones humanas no se circunscriben a una sola institución, la del mercado autoregulado, donde el hambre y la ganancia son los móviles aparentes del trabajo y la eficiencia. Esperar que el progreso y la paz mundial se logren a través del comercio es una ingenuidad engañosa y nociva. Ni un sistema nacional ni un sistema internacional pueden depender de reguladores automáticos. Los presupuestos equilibrados, la libre empresa, los tipos de cambio flexibles no garantizan el orden internacional. Sólo la sociedad puede garantizarlo, de modo que la sociedad internacional también debe ser recreada, creando las instituciones reguladoras adecuadas.Karl Polanyi is little-known among economists, though highly influential in other disciplines. The crumbling of the Eastern European regimes has renewed interest in his work, especially among those who, without wishing to justify the economic inefficiencies of the totalitarian regimes, support the restoration of human rights and would like to see governments behaving responsibly towards society, without
    relying uncritically on market forces. Liberal tradition is not enough, either there or here. Indi vidual freedoms cannot be abandoned: they must be re-created. An obsolete social sys tem , whose evils were hidden by the fog of ideology, cannot be brought back. Society must rebuild itself, learning such lessons as we are able to learn: for example, the fact that human motivation does not revolve around a single institution
    the self-regulating market where hunger and profitare the apparent motives for men to work and be efficient. It is ingenuous, and deceitfully and harmfully so, to believe that world peace and progress will be achieved by trade. Neither a national nor an international system can rely on self-regulation. Balanced budgets, free enterprise and flexible exchange rates will not secure international order: only
    society can achieve this, and international society must also be re-created, with the appropriate regulatory institutions.

  16. Environ: E00646 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available E00646 Colubridae slough (Japan) Crude drug ... Elaphe climacophora [TAX:31143], Elap...he quadrivirgata [TAX:86195], Rhabdophis tigrinus [TAX:126484] ... Colubridae Elaphe climacophora, Elaphe quadrivirgata, Rhabdophis tigrinus slough (dried) ...


    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...


    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  19. Mice serve as paratenic hosts for the transmission of Caryospora duszynskii (Apicomplexa: Eimeriidae) between snakes of the genus Elaphe

    Czech Academy of Sciences Publication Activity Database

    Modrý, David; Šlapeta, Jan Roger; Koudela, Břetislav


    Roč. 52, č. 3 (2005), s. 205-208 ISSN 0015-5683 Grant - others:GA ČR(CZ) GP524/03/D104; GA ČR(CZ) GA524/00/P015 Institutional research plan: CEZ:AV0Z60220518 Keywords : Coccidia * Eimeriidae * Caryospora duszynskii * transmission * paratenic host Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.138, year: 2005

  20. Herbage intake and animal performance of cattle grazing dwarf elaphant grass with two access times to a forage peanut area

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    Diego Melo de Liz


    Full Text Available Relatively short grazing periods in a pure legume pasture can be an alternative for increasing animal performance in medium-quality tropical pastures. Thus, the aim was to evaluate the herbage intake and animal performance of steers grazing dwarf elephant grass (Pennisetum purpureum Schum. cv. BRS Kurumi with two access times [2 h (07:00 - 9:00 and 6 h (07:00 - 13:00] to an area of forage peanut (Arachis pintoi cv. Amarillo. Twelve steers (219 ± 28.8 kg LW were divided into four groups and assessed during three consecutive grazing cycles, from January to March 2013. The crude protein and neutral detergent fiber contents were 158 and 577 g/kg dry matter (DM for dwarf elephant grass and 209 and 435 g/kg DM for forage peanut, respectively. The pre-grazing height and leaf mass of dwarf elephant grass and forage peanut were 94 cm and 2782 kg DM/ha and 15 cm and 1751 kg DM/ha, respectively. The herbage intake (mean = 2.7 ± 0.06% LW and average daily weight gain (mean = 1.16 ± 0.31 kg/day were similar for both treatments. However, animals with 2-h access to the legume paddock grazed for 71% of the time, whereas those with 6-h access grazed for 48% of the time. The performance of the steers that were allowed to graze forage peanut pasture for 2 h is similar to that of those that were allowed to graze the legume pasture for 6 h.


    Imposex, the development of male sex characteristics by female gonochoristic snails, has been documented globally and is causally associated with exposure to the ubiquitous environmental contaminant tributyltin (TBT). Elevated testosterone levels in snails also are associated wit...


    ABSTRACT Imposex, the development of male sex characteristics by female gonochoristic snails, has been causally associated with exposure to the ubiquitous environmental contaminant tributyltin (TBT). Documentation of imposex distribution indicates that this masculinizat...


    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...


    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  5. Cardiovascular responses of semi-arboreal snakes to chronic, intermittent hypergravity (United States)

    Lillywhite, H. B.; Ballard, R. E.; Hargens, A. R.


    Cardiovascular functions were studied in semi-arboreal rat snakes (Elaphe obsoleta) following long-term, intermittent exposure to +1.5 Gz (head-to-tail acceleration) on a centrifuge. Snakes were held in a nearly straight position within horizontal plastic tubes during periods of centrifugation. Centrifugal acceleration, therefore, subjected snakes to a linear force gradient with the maximal force being experienced at the tail. Compared to non-centrifuged controls, Gz-acclimated snakes showed greater increases of heart rate during head-up tilt or acceleration, greater sensitivity of arterial pressure to circulating catecholamines, higher blood levels of corticosterone, and higher blood ratios of prostaglandin F 2 alpha/prostaglandin E2. Cardiovascular tolerance to increased gravity during graded Gz acceleration was measured as the maximum (caudal) acceleration force at which carotid arterial blood flow became null. When such tolerances were adjusted for effects of body size and other continuous variables incorporated into an analysis of covariance, the difference between the adjusted mean values of control and acclimated snakes (2.37 and 2.84 Gz, respectively) corresponded closely to the 0.5 G difference between the acclimation G (1.5) and Earth gravity (1.0). As in other vertebrates, cardiovascular tolerance to Gz stress tended to be increased by acclimation, short body length, high arterial pressure, and comparatively large blood volume. Voluntary body movements were important for promoting carotid blood flow at the higher levels of Gz stress.

  6. Heterochrony and Early Left-Right Asymmetry in the Development of the Cardiorespiratory System of Snakes (United States)

    van Soldt, Benjamin J.; Metscher, Brian D.; Poelmann, Robert E.; Vervust, Bart; Vonk, Freek J.; Müller, Gerd B.; Richardson, Michael K.


    Snake lungs show a remarkable diversity of organ asymmetries. The right lung is always fully developed, while the left lung is either absent, vestigial, or well-developed (but smaller than the right). A ‘tracheal lung’ is present in some taxa. These asymmetries are reflected in the pulmonary arteries. Lung asymmetry is known to appear at early stages of development in Thamnophis radix and Natrix natrix. Unfortunately, there is no developmental data on snakes with a well-developed or absent left lung. We examine the adult and developmental morphology of the lung and pulmonary arteries in the snakes Python curtus breitensteini, Pantherophis guttata guttata, Elaphe obsoleta spiloides, Calloselasma rhodostoma and Causus rhombeatus using gross dissection, MicroCT scanning and 3D reconstruction. We find that the right and tracheal lung develop similarly in these species. By contrast, the left lung either: (1) fails to develop; (2) elongates more slowly and aborts early without (2a) or with (2b) subsequent development of faveoli; (3) or develops normally. A right pulmonary artery always develops, but the left develops only if the left lung develops. No pulmonary artery develops in relation to the tracheal lung. We conclude that heterochrony in lung bud development contributes to lung asymmetry in several snake taxa. Secondly, the development of the pulmonary arteries is asymmetric at early stages, possibly because the splanchnic plexus fails to develop when the left lung is reduced. Finally, some changes in the topography of the pulmonary arteries are consequent on ontogenetic displacement of the heart down the body. Our findings show that the left-right asymmetry in the cardiorespiratory system of snakes is expressed early in development and may become phenotypically expressed through heterochronic shifts in growth, and changes in axial relations of organs and vessels. We propose a step-wise model for reduction of the left lung during snake evolution. PMID:25555231

  7. Heterochrony and early left-right asymmetry in the development of the cardiorespiratory system of snakes. (United States)

    van Soldt, Benjamin J; Metscher, Brian D; Poelmann, Robert E; Vervust, Bart; Vonk, Freek J; Müller, Gerd B; Richardson, Michael K


    Snake lungs show a remarkable diversity of organ asymmetries. The right lung is always fully developed, while the left lung is either absent, vestigial, or well-developed (but smaller than the right). A 'tracheal lung' is present in some taxa. These asymmetries are reflected in the pulmonary arteries. Lung asymmetry is known to appear at early stages of development in Thamnophis radix and Natrix natrix. Unfortunately, there is no developmental data on snakes with a well-developed or absent left lung. We examine the adult and developmental morphology of the lung and pulmonary arteries in the snakes Python curtus breitensteini, Pantherophis guttata guttata, Elaphe obsoleta spiloides, Calloselasma rhodostoma and Causus rhombeatus using gross dissection, MicroCT scanning and 3D reconstruction. We find that the right and tracheal lung develop similarly in these species. By contrast, the left lung either: (1) fails to develop; (2) elongates more slowly and aborts early without (2a) or with (2b) subsequent development of faveoli; (3) or develops normally. A right pulmonary artery always develops, but the left develops only if the left lung develops. No pulmonary artery develops in relation to the tracheal lung. We conclude that heterochrony in lung bud development contributes to lung asymmetry in several snake taxa. Secondly, the development of the pulmonary arteries is asymmetric at early stages, possibly because the splanchnic plexus fails to develop when the left lung is reduced. Finally, some changes in the topography of the pulmonary arteries are consequent on ontogenetic displacement of the heart down the body. Our findings show that the left-right asymmetry in the cardiorespiratory system of snakes is expressed early in development and may become phenotypically expressed through heterochronic shifts in growth, and changes in axial relations of organs and vessels. We propose a step-wise model for reduction of the left lung during snake evolution.

  8. Inter- and intraspecific variation in mercury bioaccumulation by snakes inhabiting a contaminated river floodplain. (United States)

    Drewett, David V V; Willson, John D; Cristol, Daniel A; Chin, Stephanie Y; Hopkins, William A


    Although mercury (Hg) is a well-studied contaminant, knowledge about Hg accumulation in snakes is limited. The authors evaluated Hg bioaccumulation within and among four snake species (northern watersnakes, Nerodia sipedon; queen snakes, Regina septemvittata; common garter snakes, Thamnophis sirtalis; and rat snakes, Elaphe obsoleta [Pantherophis alleghaniensis]) from a contaminated site on the South River (Waynesboro, VA, USA) and two nearby reference sites. Total Hg (THg) concentrations in northern watersnake tail tissue at the contaminated site ranged from 2.25 to 13.84 mg/kg dry weight (mean: 4.85 ± 0.29), or 11 to 19 times higher than reference sites. Blood THg concentrations (0.03-7.04 mg/kg wet wt; mean: 2.24 ± 0.42) were strongly correlated with tail concentrations and were the highest yet reported in a snake species. Within watersnakes, nitrogen stable isotope values indicated ontogenetic trophic shifts that correlated with THg bioaccumulation, suggesting that diet plays a substantial role in Hg exposure. Female watersnakes had higher mean THg concentrations (5.67 ± 0.46 mg/kg) than males (4.93 ± 0.49 mg/kg), but no significant differences between sexes were observed after correcting for body size. Interspecific comparisons identified differences in THg concentrations among snake species, with more aquatic species (watersnakes and queen snakes) accumulating higher mean concentrations (5.60 ± 0.40 and 4.59 ± 0.38 mg/kg in tail tissue, respectively) than the more terrestrial species, garter snakes and rat snakes (1.28 ± 0.32 and 0.26 ± 0.09 mg/kg, respectively). The results of the present study warrant further investigation of potential adverse effects and will aid in prioritizing conservation efforts. Copyright © 2013 SETAC.

  9. Linking snake behavior to nest predation in a Midwestern bird community. (United States)

    Weatherhead, Patrick J; Carfagno, Gerardo L F; Sperry, Jinelle H; Brawn, Jeffrey D; Robinson, Scott K


    Nest predators can adversely affect the viability of songbird populations, and their impact is exacerbated in fragmented habitats. Despite substantial research on this predator-prey interaction, however, almost all of the focus has been on the birds rather than their nest predators, thereby limiting our understanding of the factors that bring predators and nests into contact. We used radiotelemetry to document the activity of two snake species (rat snakes, Elaphe obsoleta; racers, Coluber constrictor) known to prey on nests in Midwestern bird communities and simultaneously monitored 300 songbird nests and tested the hypothesis that predation risk should increase for nests when snakes were more active and in edge habitat preferred by both snake species. Predation risk increased when rat snakes were more active, for all nests combined and for two of the six bird species for which we had sufficient nests to allow separate analyses. This result is consistent with rat snakes being more important nest predators than racers. We found no evidence, however, that nests closer to forest edges were at greater risk. These results are generally consistent with the one previous study that investigated rat snakes and nest predation simultaneously. The seemingly paradoxical failure to find higher predation risk in the snakes' preferred habitat (i.e., edge) might be explained by the snakes using edges at least in part for non-foraging activities. We propose that higher nest predation in fragmented habitats (at least that attributable to snakes) results indirectly from edges promoting larger snake populations, rather than from edges directly increasing the risk of nest predation by snakes. If so, the notion of edges per se functioning as ecological "traps" merits further study.

  10. Power lines, roads, and avian nest survival: effects on predator identity and predation intensity. (United States)

    DeGregorio, Brett A; Weatherhead, Patrick J; Sperry, Jinelle H


    1 Anthropogenic alteration of landscapes can affect avian nest success by influencing the abundance, distribution, and behavior of predators. Understanding avian nest predation risk necessitates understanding how landscapes affect predator distribution and behavior. 2 From a sample of 463 nests of 17 songbird species, we evaluated how landscape features (distance to forest edge, unpaved roads, and power lines) influenced daily nest survival. We also used video cameras to identify nest predators at 137 nest predation events and evaluated how landscape features influenced predator identity. Finally, we determined the abundance and distribution of several of the principal predators using surveys and radiotelemetry. 3 Distance to power lines was the best predictor of predator identity: predation by brown-headed cowbirds (Molothrus ater), corvids (Corvus sp. and Cyanocitta cristata), racers (Coluber constrictor), and coachwhips (Masticophis flagellum) increased with proximity to power lines, whereas predation by rat snakes (Elaphe obsoleta) and raptors decreased. In some cases, predator density may reliably indicate nest predation risk because racers, corvids, and cowbirds frequently used power line right-of-ways. 4 Of five bird species with enough nests to analyze individually, daily nest survival of only indigo buntings (Passerina cyanea) decreased with proximity to power lines, despite predation by most predators at our site being positively associated with power lines. For all nesting species combined, distance to unpaved road was the model that most influenced daily nest survival. This pattern is likely a consequence of rat snakes, the locally dominant nest predator (28% of predation events), rarely using power lines and associated areas. Instead, rat snakes were frequently associated with road edges, indicating that not all edges are functionally similar. 5 Our results suggest that interactions between predators and landscape features are likely to be specific to

  11. Cardiovascular Responses of Snakes to Gravitational Gradients (United States)

    Hsieh, Shi-Tong T.; Lillywhite, H. B.; Ballard, R. E.; Hargens, A. R.; Holton, Emily M. (Technical Monitor)


    Snakes are useful vertebrates for studies of gravitational adaptation, owing to their elongate body and behavioral diversification. Scansorial species have evolved specializations for regulating hemodynamics during exposure to gravitational stress, whereas, such adaptations are less well developed in aquatic and non-climbing species. We examined responses of the amphibious snake,\\italicize (Nerodia rhombifera), to increments of Gz (head-to-tail) acceleration force on both a short- and long-arm centrifuge (1.5 vs. 3.7 m radius, from the hub to tail end of snake). We recorded heart rate, dorsal aortic pressure, and carotid arterial blood flow during stepwise 0.25 G increments of Gz force (referenced at the tail) in conscious animals. The Benz tolerance of a snake was determined as the Gz level at which carotid blood flow ceased and was found to be significantly greater at the short- than long-arm centrifuge radius (1.57 Gz vs. 2.0 Gz, respectively; P=0.016). A similar pattern of response was demonstrated in semi-arboreal rat snakes,\\italicize{Elaphe obsoleta}, which are generally more tolerant of Gz force (2.6 Gz at 1.5m radius) than are water snakes. The tolerance differences of the two species reflected cardiovascular responses, which differed quantitatively but not qualitatively: heart rates increased while arterial pressure and blood flow decreased in response to increasing levels of Gz. Thus, in both species of snakes, a reduced gradient of Gz force (associated with greater centrifuge radius) significantly decreases the Gz level that can be tolerated.

  12. Cardiovascular responses of snakes to hypergravity (United States)

    Lillywhite, H. B.; Ballard, R. E.; Hargens, A. R.; Rosenberg, H. I.


    Snakes have provided useful vertebrate models for understanding circulatory adaptation to gravity, attributable to their elongate body shape and evolutionary diversificaton in terms of ecology and behavior. Recently we have studied cardiovascular responses of snakes to hypergravic acceleration forces produced acutely in the head-to-tail direction (+Gz) on a short-arm centrifuge. Snakes were held in a nearly straight position within a horizontal plastic tube and subjected to a linear force gradient during acceleration. Carotid blood flow provided an integrated measure of cardiovascular performance. Thus, cardiovascular tolerance of snakes to stepwise increments of Gz was measured as the caudal Gz force at which carotid blood flow ceased. Tolerance to increasing Gz varies according to adaptive evolutionary history inferred from the ecology and behavior of species. With respect to data for six species we investigated, multiple regression analysis demonstrates that Gz tolerance correlates with gravitational habitat, independently of body length. Relative to aquatic and non-climbing species, carotid blood flow is better maintained in arboreal or scansorial species, which tolerate hypergravic forces of +2 to +3.5 Gz. Additionally, semi-arboreal rat snakes (Elaphe obsoleta) exhibit plasticity of responses to long-term, intermittent +1.5 Gz stress. Compared to non-acclimated controls, acclimated snakes show greater increases of heart rate during head-up tilt or acceleration, greater sensitivity of arterial pressure to circulating catecholamines, higher blood levels of prostaglandin ratios favorable to maintenance of arterial blood pressure, and medial hypertrophy in major arteries and veins. As in other vertebrates, Gz tolerance of snakes is enhanced by acclimation, high arterial pressure, comparatively large blood volume, and body movements. Vascular studies of snakes suggest the importance to acclimation of local responses involving vascular tissue, in addition to

  13. Heterochrony and early left-right asymmetry in the development of the cardiorespiratory system of snakes.

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    Benjamin J van Soldt

    Full Text Available Snake lungs show a remarkable diversity of organ asymmetries. The right lung is always fully developed, while the left lung is either absent, vestigial, or well-developed (but smaller than the right. A 'tracheal lung' is present in some taxa. These asymmetries are reflected in the pulmonary arteries. Lung asymmetry is known to appear at early stages of development in Thamnophis radix and Natrix natrix. Unfortunately, there is no developmental data on snakes with a well-developed or absent left lung. We examine the adult and developmental morphology of the lung and pulmonary arteries in the snakes Python curtus breitensteini, Pantherophis guttata guttata, Elaphe obsoleta spiloides, Calloselasma rhodostoma and Causus rhombeatus using gross dissection, MicroCT scanning and 3D reconstruction. We find that the right and tracheal lung develop similarly in these species. By contrast, the left lung either: (1 fails to develop; (2 elongates more slowly and aborts early without (2a or with (2b subsequent development of faveoli; (3 or develops normally. A right pulmonary artery always develops, but the left develops only if the left lung develops. No pulmonary artery develops in relation to the tracheal lung. We conclude that heterochrony in lung bud development contributes to lung asymmetry in several snake taxa. Secondly, the development of the pulmonary arteries is asymmetric at early stages, possibly because the splanchnic plexus fails to develop when the left lung is reduced. Finally, some changes in the topography of the pulmonary arteries are consequent on ontogenetic displacement of the heart down the body. Our findings show that the left-right asymmetry in the cardiorespiratory system of snakes is expressed early in development and may become phenotypically expressed through heterochronic shifts in growth, and changes in axial relations of organs and vessels. We propose a step-wise model for reduction of the left lung during snake evolution.

  14. The influence of the temperature at the intensity of the spread of the cotton bollworm (heliothis obsoleta fabr. = helicoverpa armigera hb.) as a pest of the peppers in the Strumica region


    Spasov, Dusan; Spasova, Dragica; Ilievski, Mite; Atanasova, Biljana


    H. armigera is typical polyphagous insect which attacks: tomatoes, peppers, tobacco, maize, cotton, garlic, onions, cabbage, soy, beans and many other leguminous and pumpkin crops and various weed plants. The damages from the cotton bollworm have economic importance, especially when the species is in progradation. It is widespread all over the world, especially in warmer climates. The increase in the population of this cotton bollworm is associated with global warming.


    Directory of Open Access Journals (Sweden)

    María del Carmen González Viaña


    Full Text Available Este trabalho tem por objetivo apresentar a aplicação de conceitos teóricos do desenvolvimento turísitico da Linea Sur (provincia de Rio Negro, uma zona rural tradicional na produção pecuária, fortemente castigada pelas mudanças ocorridas na economia global e pela escassa visão estatégica de longo prazo de seus atores, que a tem levado a um estado de prostação, pauperização e de falta de perspectivas. Ao mesmo tempo, trata-se de uma zona que apresenta um rico patrimônio humano, material e cultural, que a faz propicia para o desenvolvimento turísitico. Palavras-chave: Desenvolvimento local. Turismo rural. Turismo criativo.

  16. Threatened Vertebrate Species Occurring or Believed to Occur in the Floodplains of the Mississippi River between Cairo, Illinois, and Minneapolis, Minnesota, and of the Illinois Waterway between Grafton, Illinois, and Chicago, Illinois, (United States)


    heterophylla), and black willow (Salix nigra), with swamp white oak ( Quercus bicolor) and pin oak (p. valustri3) also important. Skorepa and Ozment (1968...of its original prairie habitat has seen destroyed. GREAT PLAINS RAT SNAKE Elaphe guttata emoryi (Baird and Girard) (Ill. -Rare) The Great Plains Rat...forficatus 119 F Clemmys guttata 41, 117 Elaphe guttata emoryi 49, 118 Cnemidophorus sexlineatus 43, 44, 117 Elassoma zonatum. 27, 114 Colinus virginianus

  17. Isolating weather effects from seasonal activity patterns of a temperate North American Colubrid (United States)

    Andrew D. George; Frank R. III Thompson; John. Faaborg


    Forecasting the effects of climate change on threatened ecosystems and species will require an understanding of how weather influences processes that drive population dynamics. We have evaluated weather effects on activity patterns of western ratsnakes, a widespread predator of birds and small mammals in eastern North America. From 2010-2013 we radio-tracked 53...

  18. Análisis, diseño e implementación de una página web y su gestión para un grupo de centros médicos


    Salinero Comesaña, Javier


    Aquest projecte tracta l'actualització d'una pàgina Web d'un centre mèdic, que amb el pas del temps és obsoleta, i que vol obrir nous centres. Este proyecto trata la actualización de una página Web de un centro médico, que con el paso del tiempo está obsoleta, y que quiere abrir nuevos centros. This project aims at updating a medical center website, which over time is no longer up-to-date, and tries to open new centers.

  19. Relics of the Europe's warm past: Phylogeography of the Aesculapian snake

    Czech Academy of Sciences Publication Activity Database

    Musilová, Radka; Zavadil, V.; Marková, Silvia; Kotlík, Petr


    Roč. 57, - (2010), s. 1245-1252 ISSN 1055-7903 R&D Projects: GA MŠk LC06073 Institutional research plan: CEZ:AV0Z50450515 Keywords : Elaphe longissima * Holocene climatic optimum * Isolated populations Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.889, year: 2010

  20. The king of snakes: performance and morphology of intraguild predators (Lampropeltis) and their prey (Pantherophis). (United States)

    Penning, David A; Moon, Brad R


    Across ecosystems and trophic levels, predators are usually larger than their prey, and when trophic morphology converges, predators typically avoid predation on intraguild competitors unless the prey is notably smaller in size. However, a currently unexplained exception occurs in kingsnakes in the genus Lampropeltis Kingsnakes are able to capture, constrict and consume other snakes that are not only larger than themselves but that are also powerful constrictors (such as ratsnakes in the genus Pantherophis ). Their mechanisms of success as intraguild predators on other constrictors remain unknown. To begin addressing these mechanisms, we studied the scaling of muscle cross-sectional area, pulling force and constriction pressure across the ontogeny of six species of snakes ( Lampropeltis californiae , L. getula , L. holbrooki , Pantherophis alleghaniensis , P. guttatus and P. obsoletus ). Muscle cross-sectional area is an indicator of potential force production, pulling force is an indicator of escape performance, and constriction pressure is a measure of prey-handling performance. Muscle cross-sectional area scaled similarly for all snakes, and there was no significant difference in maximum pulling force among species. However, kingsnakes exerted significantly higher pressures on their prey than ratsnakes. The similar escape performance among species indicates that kingsnakes win in predatory encounters because of their superior constriction performance, not because ratsnakes have inferior escape performance. The superior constriction performance by kingsnakes results from their consistent and distinctive coil posture and perhaps from additional aspects of muscle structure and function that need to be tested in future research. © 2017. Published by The Company of Biologists Ltd.

  1. Diseño de un biorreactor a partir de un autoclave en deshuso

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    Teresa Salazar-Rojas


    Este artículo detalla el proceso de construcción de un prototipo de biorreactor piloto, con todas las características necesarias para su funcionalidad, partiendo de una autoclave obsoleta. Con el fin de dar ejemplo de cómo se puede extender la vida útil de un material de desecho y, además, minimizar costos al obtener un equipo 100% funcional.

  2. Molecular Identification of Cryptosporidium Species from Pet Snakes in Thailand


    Yimming, Benjarat; Pattanatanang, Khampee; Sanyathitiseree, Pornchai; Inpankaew, Tawin; Kamyingkird, Ketsarin; Pinyopanuwat, Nongnuch; Chimnoi, Wissanuwat; Phasuk, Jumnongjit


    Cryptosporidium is an important pathogen causing gastrointestinal disease in snakes and is distributed worldwide. The main objectives of this study were to detect and identify Cryptosporidium species in captive snakes from exotic pet shops and snake farms in Thailand. In total, 165 fecal samples were examined from 8 snake species, boa constrictor (Boa constrictor constrictor), corn snake (Elaphe guttata), ball python (Python regius), milk snake (Lampropeltis triangulum), king snake (Lampropel...

  3. Karyotype Reorganization in the Hokou Gecko (Gekko hokouensis, Gekkonidae): The Process of Microchromosome Disappearance in Gekkota


    Srikulnath, Kornsorn; Uno, Yoshinobu; Nishida, Chizuko; Ota, Hidetoshi; Matsuda, Yoichi


    The Hokou gecko (Gekko hokouensis: Gekkonidae, Gekkota, Squamata) has the chromosome number 2n = 38, with no microchromosomes. For molecular cytogenetic characterization of the gekkotan karyotype, we constructed a cytogenetic map for G. hokouensis, which retains the ancestral karyotype of Gekkota, with 86 functional genes, and compared it with cytogenetic maps for four Toxicofera species that have many microchromosomes (Elaphe quadrivirgata, Varanus salvator macromaculatus, Leiolepis reevesii...

  4. Debunking the viper's strike: harmless snakes kill a common assumption. (United States)

    Penning, David A; Sawvel, Baxter; Moon, Brad R


    To survive, organisms must avoid predation and acquire nutrients and energy. Sensory systems must correctly differentiate between potential predators and prey, and elicit behaviours that adjust distances accordingly. For snakes, strikes can serve both purposes. Vipers are thought to have the fastest strikes among snakes. However, strike performance has been measured in very few species, especially non-vipers. We measured defensive strike performance in harmless Texas ratsnakes and two species of vipers, western cottonmouths and western diamond-backed rattlesnakes, using high-speed video recordings. We show that ratsnake strike performance matches or exceeds that of vipers. In contrast with the literature over the past century, vipers do not represent the pinnacle of strike performance in snakes. Both harmless and venomous snakes can strike with very high accelerations that have two key consequences: the accelerations exceed values that can cause loss of consciousness in other animals, such as the accelerations experienced by jet pilots during extreme manoeuvres, and they make the strikes faster than the sensory and motor responses of mammalian prey and predators. Both harmless and venomous snakes can strike faster than the blink of an eye and often reach a target before it can move. © 2016 The Author(s).

  5. El propósito del dibujo


    Salgado de la Rosa, María Asunción; Fullaondo Buigas de Dalmau, María; Márquez Salmerón, Ciro


    La organización de las asignaturas de dibujo en las escuelas de arquitectura ha respondido tradicionalmente a un patrón heredado de tiempos pasados cuyas fórmulas hoy en día, han quedado completamente obsoletas. Tradicionalmente este aprendizaje se concentraba exclusivamente en el primer año de carrera y algunas escuelas ampliaban esa formación al segundo curso. Durante ese primer año de carrera el alumno adquiría los conocimientos básicos sobre los distintos tipos de dibujo, que eran bás...

  6. Transformación de zonas portuarias y costeras en desuso: experiencias, posibilidades y problemas


    Schubert, Dirk


    El concepto de revitalización urbana se aplica a procesos y planteamientos muy diferentes relacionados con la actuación sobre áreas costeras y portuarias obsoletas de todo el mundo. Se trata de actuaciones todas ellas con una gran trascendencia sobre la estructura general de las ciudades pero, a menudo, sus objetivos son muy distintos e incluso contradictorios. El artículo analiza algunos de los proyectos de revitalización portuaria más conocidos y los clasifica en función de su meta caracter...


    Directory of Open Access Journals (Sweden)

    Z. M. Mamedov


    Full Text Available Two hundreds and twenty species parasites and predators of pests of various agricultures are revealed in Azerbaijan. The complex of entomophages of certain pests of agricultures is studied: 48 species of parasites and predators of Chloridea obsoleta 21 species of entomophages of Pectinophora malvella Hb., over 160 species of entomophages of pests of ozehards and vegetables, 34 species of entomophages of pests of forests. The hundreds species of entomophages and some entomophogenous microbes and antagonists are revealed. Biology and ecology of over 60 species of entomophages and useful microorganisims which are prospective as biological control agents are studied.

  8. Doubtful records of reptile species in some areas of the Danube Delta Biosphere Reserve (Romania

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    TÖRÖK Zsolt Csaba


    Full Text Available In the present paper there are provided details on the doubtful data on the occurrence of some reptile species in various parts of the Danube Delta Biosphere Reserve. Testudo graeca was indicated by mistake at Sfântu Gheorghe (probably the authors saw the species in some places from the continental plateau nearby of Sfântu Gheorghe branch, not inside the Danube Delta. Lacerta viridis was mentioned in the so-called “maritime Delta” and at the ruins of Histria fortress (due to confusion with specimens of Lacerta agilis. Also, Podarcis muralis was “recorded” at the ruins of Histria fortress (due to misidentification of specimens belonging to species P. taurica. A corps of snake found at Letea forest was considered by mistake as belonging to species Eryx jaculus. In several official reports (grey literature the species Elaphe longissima (Zamenis longissimus was mentioned by mistake as occurring at Letea forest. Elaphe (quatuorlineata sauromates was “recorded” at the ruins of Histria fortress and at Sfântu Gheorghe due to confusion with specimens belonging to other snake species. Specimens of Vipera urisnii from the Danube Delta were considered as belonging to the species Vipera berus. Also, Vipera ursinii was metioned by mistake at Caraorman marine levee and at Chituc marine levee, based only on the idea that if the species occurs on other marine levees, it has to be present on these two marine levees, too.

  9. Adopción de mejores prácticas en la prestación de servicios de infraestructura de TI: de la teoría a la práctica


    Pineda Jiménez, Gloria


    Las organizaciones viven en un entorno de constante cambio, que tiene ciclos cada vez más rápidos -- Sin embargo, la tecnología no ha cambiado dentro de las organizaciones, al mismo ritmo que los cambios de las organizaciones -- Las pequeñas y medianas empresas tienen tecnología obsoleta; por lo que las inversiones en tecnología tienden a ser más grande y más costoso en el tiempo si no se hacen de manera planeada -- Esto crea una situación más compleja para vender una inversión en TI a nivel ...

  10. Milpa y capitalismo: opciones para los campesinos mayas yucatecos contemporáneos

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    Manuel Martín Castillo


    Full Text Available La mayoría de los mayas yucatecos contemporáneos vive en la pobreza. El eje de su economía y cultura es la agricultura de milpa, que los jóvenes no encuentran atractiva como opción económica. La teoría económica convencional explica la pobreza por la escasez de capital, el uso de tecnologías obsoletas y la baja productividad. Aunque se concibe como un sistema productivo arcaico, la milpa tiene características para explorar opciones de vinculación entre las economías campesina y capitalista, para mejorar las condiciones de vida de los campesinos y contribuir al desarrollo de su cultura en el actual contexto de globalización económica.

  11. Ciencia y tecnología, más allá los medios masivos

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    Marco Ordóñez Andrade


    Full Text Available Es menester superar la creencia tradicional que circunscribe la comunicación al uso de los medios de comunicación social, o lo que es más grave a operativos de las llamadas "relaciones públicas" cuya base conceptual resulta obsoleta e impropia para la concepción de los problemas de la comunicación y la sociedad. Un tipo de información que acumule conocimientos -educación bancaria- no tiene ningún valor, hay que optar por sistemas de comunicación que induzcan a la reflexión crítica de los problemas en los que están inmersos los grupos o segmentos de la sociedad.


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    Cindy Hörmansdörfer


    Resultados: La IPEM alcanzó una sensibilidad de 57,50%, detectando 23 de 40 casos de trisomía, y una tasa de falsos positivos de 21,60%. En comparación, todos los programas obtuvieron mejores resultados alcanzando una sensibilidad entre 90,00% (AFS y 92,50% (PIA, PRC, JOY, AFS-3D y una tasa de falsos positivos entre 2,64% (AFS-3D y 7,87% (PIA. La diferencia fue de alta significancia (p<0,0001. Conclusiones: La IPEM es obsoleta e inadecuada en comparación a los programas de cálculo de riesgo, de los cuales todos demostraron rendimientos que se encuentran dentro del rango de publicaciones internacionales comparables. Entre estos programas JOY, AFS y AFS-3D obtuvieron los mejores resultados.

  13. Infective larvae of Rhabdiasidae (Nematoda): comparative morphology of seven European species. (United States)

    Kuzmin, Yuriy; Junker, Kerstin; Bain, Odile


    The morphology of infective third-stage larvae of Rhabdias bufonis, R. rubrovenosa, R. sphaerocephala, R. fuscovenosa, R. elaphe, Entomelas entomelas and E. dujardini is described. The sheath structure in the studied larvae appeared to be similar to that described in other species of the family Rhabdiasidae, its chequered aspect being caused by a combination of outer longitudinal striations and inner longitudinal as well as transverse ridges. The larvae were similar in general morphology but differed in the presence/absence of anterior apical protuberances (pseudolabia), the shape and ornamentation of the tail tip, and the structure of lateral alae in the caudal region of the body. No relationship between the morphological characters of the larvae of the studied species and their taxonomic position or specificity of adult parasites to a particular host group was observed. Regardless, the larvae of each species can be identified by a combination of morphological peculiarities in the anterior and caudal regions of the body.

  14. Completion of the life cycle of Sarcocystis zuoi , a parasite from the Norway rat, Rattus norvegicus. (United States)

    Hu, Jun-Jie; Meng, Yu; Guo, Yan-Mei; Liao, Jie-Ying; Song, Jing-Ling


    Transmission experiments were performed to elucidate the life cycle of Sarcocystis zuoi found in Norway rats ( Rattus norvegicus ) in China. Two king rat snakes ( Elaphe carinata ) fed sarcocysts from the muscles of 4 naturally infected Norway rats shed sporocysts measuring 10.8 ± 0.7 × 8.0 ± 0.7 µm, with a prepatent period of 8-9 days. Sporocysts from the intestine of 2 experimentally infected king rat snakes were given to the laboratory Sprague-Dawley (SD) rats ( R. norvegicus ) and Kunming (KM) mice ( Mus musculus ). Microscopic sarcocysts developed in the skeletal muscles of SD rats. No sarcocysts were observed in KM mice. Characters of ultrastructure and molecule of sarcocysts from SD rats were confirmed as S. zuoi . Our results indicate that king rat snake is the definitive host of S. zuoi .

  15. Ontogenetic shifts of heart position in snakes. (United States)

    Lillywhite, Harvey B; Lillywhite, Steven M


    Heart position relative to total body length (TL) varies among snakes, with anterior hearts in arboreal species and more centrally located hearts in aquatic or ground-dwelling species. Anterior hearts decrease the cardiac work associated with cranial blood flow and minimize drops in cranial pressure and flow during head-up climbing. Here, we investigate whether heart position shifts intraspecifically during ontogenetic increases in TL. Insular Florida cottonmouth snakes, Agkistrodon conanti, are entirely ground-dwelling and have a mean heart position that is 33.32% TL from the head. In contrast, arboreal rat snakes, Pantherophis obsoleta, of similar lengths have a mean heart position that is 17.35% TL from the head. In both species, relative heart position shifts craniad during ontogeny, with negative slopes = -.035 and -.021% TL/cm TL in Agkistrodon and Pantherophis, respectively. Using a large morphometric data set available for Agkistrodon (N = 192 individuals, 23-140 cm TL), we demonstrate there is an anterior ontogenetic shift of the heart position within the trunk (= 4.56% trunk length from base of head to cloacal vent), independent of head and tail allometry which are both negative. However, in longer snakes > 100 cm, the heart position reverses and shifts caudally in longer Agkistrodon but continues toward the head in longer individuals of Pantherophis. Examination of data sets for two independent lineages of fully marine snakes (Acrochordus granulatus and Hydrophis platurus), which do not naturally experience postural gravity stress, demonstrate both ontogenetic patterns for heart position that are seen in the terrestrial snakes. The anterior migration of the heart is greater in the terrestrial species, even if TL is standardized to that of the longer P. obsoleta, and compensates for about 5 mmHg gravitational pressure head if they are fully upright. © 2017 Wiley Periodicals, Inc.

  16. Nocturnal arboreality in snakes in the swamplands of the Atchafalaya Basin of south-central Louisiana and Big Thicket National Preserve of Southeast Texas (United States)

    Glorioso, Brad M.; Waddle, J. Hardin


    The southeastern United States is home to a diverse assemblage of snakes, but only one species, the Rough Greensnake (Opheodrys aestivus), is considered specialized for a predominantly arboreal lifestyle. Other species, such as Ratsnakes (genus Pantherophis) and Ribbonsnakes/Gartersnakes (genus Thamnophis), are widely known to climb into vegetation and trees. Some explanations given for snake climbing behavior are foraging, thermoregulation, predator avoidance, and response to flood. Reports of arboreality in snake species typically not associated with life in the trees (such as terrestrial, aquatic, and even fossorial species) usually come from single observations, with no knowledge of prevalence of the behavior. Here, we report on arboreality of snake species detected during 8 years of night surveys in the Atchafalaya Basin of south-central Louisiana and 5+ years of night surveys in Big Thicket National Preserve in southeast Texas. We recorded a total of 1,088 detections of 19 snake species between the two study areas, with 348 detections above ground level (32%). The Rough Greensnake and Western Ribbonsnake (Thamnophis proximus) accounted for nearly 75% of total arboreal detections among the two study areas. However, with one exception, all snake species detected more than once between both study areas had at least one arboreal detection. These observations demonstrate that snakes with widely varying natural histories may be found in the trees at night, and for some species, this behavior may be more common than previously believed.

  17. Linking snake habitat use to nest predation risk in grassland birds: the dangers of shrub cover. (United States)

    Klug, Page E; Jackrel, Sara L; With, Kimberly A


    Extremes in rangeland management, varying from too-frequent fire and intensive grazing to the suppression of both, threaten rangeland ecosystems worldwide. Intensive fire and grazing denude and homogenize vegetation whereas their suppression increases woody cover. Although habitat loss is implicated in grassland bird declines, degradation through intensive management or neglect also decreases breeding habitat and may reduce nesting success through increased rates of nest predation. Snakes are important nest predators, but little is known about how habitat use in snakes relates to predation risk for grassland birds nesting within tallgrass prairie subjected to different grazing and fire frequencies. We evaluated nest survival in the context of habitat used by nesting songbirds and two bird-eating snakes, the eastern yellowbelly racer Coluber constrictor flaviventris and Great Plains ratsnake Pantherophis emoryi. Daily nest survival rates decreased with increasing shrub cover and decreasing vegetation height, which characterize grasslands that have been neglected or intensively managed, respectively. Discriminant function analysis revealed that snake habitats were characterized by higher shrub cover, whereas successful nests were more likely to occur in areas with tall grass and forbs but reduced shrub cover. Because snakes often use shrub habitat, birds nesting in areas with increased shrub cover may be at higher risk of nest predation by snakes in addition to other predators known to use shrub habitat (e.g., mid-sized carnivores and avian predators). Depredated nests also occurred outside the discriminant space of the snakes, indicating that other predators (e.g., ground squirrels Spermophilus spp. and bullsnakes Pituophis catenifer) may be important in areas with denuded cover. Targeted removal of shrubs may increase nest success by minimizing the activity of nest predators attracted to shrub cover.

  18. La sucesión "mortis causa" en la explotación agrícola familiar

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    José Luis De Los Mozos


    Full Text Available Llevo nada menos que cuarenta años dando vueltas al tema de la sucesión mortis causa en el Derecho agrario y más concretamente, al de la sucesión en la explotación agrícola. Esto no constituye ningún mérito, naturalmente, no es más que una mera circunstancia que acredita, cuando mucho, la firmeza de una convicción. Durante este tiempo, con mayor o menor contacto con la realidad social, he seguido y sigo fiel a mis puntos de vista originarios; no es que nada haya cambiado en todos estos años, sino que ha cambiado casi todo.Pero es que las soluciones que me parecían entonces muy dudosas, ahora me parecen inadmisibles.La evolución económica y social, ha puesto de relieve que las ideas que se utilizaban hace medio siglo en la materia, actualmente han quedado obsoletas (...Contenido: Una distinción obligada y un recuerdo inevitable. El recurso a la atribución preferente. Las condicionantes de la atribución preferente. El concepto de explotación agrícola. La reforma del derecho sucesorio como recapitulación

  19. Optimization of Conditions for In Vitro Culture of the Microphallid Digenean Gynaecotyla adunca

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    Jenna West


    Full Text Available In vitro cultivation of digeneans would aid the development of effective treatments and studies of the biology of the parasites. The goal of this study was to optimize culture conditions for the trematode, Gynaecotyla adunca. Metacercariae of the parasite from fiddler crabs, Uca pugnax, excysted in trypsin, were incubated overnight to permit fertilization, and were cultured in different conditions to find those that resulted in maximum worm longevity and egg production. When cultured in media lacking serum, worms lived longer in Hanks balanced salt solution and Dulbecco’s Modified Eagle medium/F-12 (DME/F-12 than in RPMI-1640 but produced the most eggs in DME/F-12. Worm longevity and egg production increased when worms were grown in DME/F-12 supplemented with 20% chicken, horse, or newborn calf serum but the greatest number of eggs was deposited in cultures containing horse or chicken serum. Horse serum was chosen over chicken serum due to the formation of a precipitate in chicken serum. The optimal concentration of horse serum with respect to egg production ranged from 5 to 20%. Infectivity of eggs deposited by worms in culture was tested by feeding eggs to mud snails, Ilyanassa obsoleta. None of these snails produced G. adunca cercariae.

  20. La pregunta por el cambio social y su conceptualización en términos de contradicción, conflicto y crisis

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    Eugenia Fraga


    Full Text Available En el presente trabajo indagaremos en las distintas respuestas que se han dado desde dos grandes paradigmas del pensamiento occidental a la pregunta por el cambio social. En particular, nos interesa rastrear de qué manera las diversas variantes de la perspectiva estructuralista y de la perspectiva historicista han conceptualizado el cambio social, especialmente en términos de contradicción, de conflicto y de crisis. Dentro de la perspectiva estructuralista recorreremos los aportes clásicos de Chalmers Johnson y Gino Germani, para luego pasar a algunos referentes contemporáneos como Theda Skocpol, Peter Evans y Fred Block; dentro de la perspectiva historicista, nos detendremos en los aportes clásicos de Karl Marx y luego en dos referentes del siglo xx como Beverly Silver y Norbert Elias. Hacia el final del trabajo, veremos, entre otras cosas, cómo esta primera división en paradigmas resulta en cierta medida, y para el caso entre manos, obsoleta.

  1. Testosterone-Fatty Acid esterification: a unique target for the endocrine toxicity of tributyltin to gastropods. (United States)

    Leblanc, Gerald A; Gooding, Meredith P; Sternberg, Robin M


    Over the past thirty years, a global occurrence of sexual aberration has occurred whereby females among populations of prosobranch snails exhibit male sex characteristics. This condition, called imposex, has been causally associated with exposure to the biocide tributyltin. Tributyltin-exposed, imposex snails typically have elevated levels of testosterone which have led to the postulate that this endocrine dysfunction is responsible for imposex. This overview describes recent evidence that supports this postulate. Gastropods maintain circulating testosterone levels and administration of testosterone to females or castrates stimulates male sex differentiation in several snail species. Studies in the mud snail (Ilyanassa obsoleta) have shown that gastropods utilize a unique strategy for regulating free testosterone levels. Excess testosterone is converted to fatty acid esters by the action of a testosterone-inducible, high capacity/low affinity enzyme, acyl-CoA:testosterone acyl transferase, and stored within the organisms. Free testosterone levels are regulated during the reproductive cycle apparently due to changes in esterification/desterification suggesting that testosterone functions in the reproductive cycle of the organisms. Testosterone esterification provides a unique target in the testosterone regulatory machinery of snails that is altered by tributyltin. Indeed, imposex and free testosterone levels were elevated in field collected snails containing high tin levels, while testosterone-fatty acid ester pools were reduced in these organisms. These observations indicate that tributyltin elevates free testosterone by reducing the retention of testosterone as fatty acid-esters. This endocrine effect of tributyltin may be responsible for imposex.

  2. El plan de mejora del hábitat minero de Asturias (1966-1969. Bases, contexto y balance territorial.

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    Faustino Suárez Antuña


    Full Text Available El fin del periodo autárquico dejaba las comarcas mineras asturianas en una difícil situación. Las estructuras productivas estaban obsoletas, lo que dificultaba la competitividad de su carbón y acero en un nuevo contexto de mercado libre y abierto. Pero más acuciante aún era lo que se refería a su tejido urbano y social. En los años sesenta del siglo XX muchos lugares carecían aún de infraestructuras básicas como carreteras, luz o agua, y todas las cuencas presentaban escasos equipamientos educativos, deportivos, y culturales. El Plan de Mejora del Hábitat Minero intentó corregir estos desequilibrios antes de abordar la reestructuración de sus sectores industriales principales.The autarkic period end left the Asturian mining regions in a difficult situation. Production structures were obsolete, leaving little room to the competitiveness of its coal and steel in a new context of free and open trade. But even more pressing it was regarding its urban and social fabric. In the Sixties of the twentieth century many places still lacked basic infrastructures like roads, electricity or water, and all the basins had little education facilities, sports, and libraries. The Mining Habitat Improvement Plan of will try to correct these imbalances before addressing the restructuring of its main industrial sectors.

  3. De la sociedad de trabajo a la sociedad tecnológica

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    Full Text Available En la sociedad actual, caracterizada por la revolución tecnoproductiva (el crecimiento y la difusión acelerados de industrias de alta tecnología, como, por ejemplo, el tratamiento de la información, las comunicaciones avanzadas, y la biotecnología y por un cambio en la mentalidad del "estado de bienestar" en lo que concierne a las preocupaciones por la calidad de vida y la intimidad, es recomendable que los valores tradicionales rígidos con respecto al trabajo, sean reestructurados según los nuevos criterios sociales y económicos. Los problemas sociales actuales - por ejemplo, el alto desempleo y las injusticias sociales entre aquéllos incluidos en la jerarquía de la alta tecnología y aquéllos que son excluidos a causa de unas habilidades y una educación obsoletas - se podrían mejorar por medio de una mayor preocupación por el capital humano, la desburocratización, y a través de iniciativas sociales. Se detallan las estrategias específicas para tales cambios, como por ejemplo aquellas propuestas por A. Gorz ("El que no trabaje, comerá", Letra Internacional, 1986, 3.

  4. Effects of Silver and Other Metals on the Cytoskeleton (United States)

    Conrad, Gary W.


    Directly or indirectly, trace concentrations of silver ion (Ag(+)) stabilize microtubules (Conrad, A.H., et al. Cell Motil. & Cytoskel. 27:117-132), as does taxol (Conrad, A.H., et al. J. Exp. Zool. 262:154-165), an effect with major consequences for cellular shape changes and development. Polymerization of microtubules is gravity-sensitive (Tabony and Job, Proc. Natl. Acad. Sci. USA 89:6948-6952), so trace amounts of Ag(+) may alter cellular ability to respond to gravity. If Ag electrolysis is used to purify water on NASA space vehicles, plants and animals/astronauts will be exposed continuously to Ag(+), a regimen with unknown cellular and developmental consequences. Fertilized eggs of the marine mudsnail, Ilyanassa obsoleta, are the cells in which the effects of A(+) on microtubules were discovered. They distribute visible cytoplasmic contents according to gravity and contain cytoplasmic morphogenetic determinants for heart development. The objectives are to determine if the effects of Ag(+), AU(3+), (of biosensor relevance), or Gd(3+) (inhibitor of some stretch-activated ion channels) on the cytoskeleton (in the presence and absence of mechanical loading) will affect cellular responses to gravity.

  5. Empire. 

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    Francisco José Robles Rodrí­guez


    Full Text Available Michael Hardt y Antonio Negri han pensado el estado de cosas resultante del proceso globalizador, -acelerado desde el fin de la guerra fría-, desde la noción de Imperio, confrontándola a la de imperialismo económico -la cual estaría obsoleta desde la caída del bloque comunista. Ahora bien, si, con Negri y Hardt, puede afirmarse el carácter no imperialista sino imperial del Imperio actualmente existente y, también con Negri y Hardt, debe reconocerse el carácter acosmista, de riesgo constante de las intervenciones y de desigualdad en las imposiciones y reestructuraciones de este nuestro Imperio, lo que no puede ser admitido desde el materialismo filosófico es la renuncia al entendimiento dialéctico del momento histórico presente para introducir como sucedáneo sustitutivo las nociones deleuzianas de diferencia y repetición.

  6. Grazer Functional Roles, Induced Defenses, and Indirect Interactions: Implications for Eelgrass Restoration in San Francisco Bay

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    Jeffrey T. Lewis


    Full Text Available Understanding the individual and interactive roles of consumer species is more than academic when the host plant is a subject of intense conservation interest. In a mesocosm experiment, we compared effects of common invertebrate grazers in San Francisco Bay seagrass (Zostera marina, eelgrass beds, finding that some species (a native opisthobranch, Phyllaplysia taylori; a native isopod, Idotea resecata; and an introduced gastropod, Ilyanassa obsoleta enhanced eelgrass growth through removal of epiphytic algae, as is often predicted for small invertebrate grazers on seagrasses, while one (an introduced caprellid amphipod, Caprella cf. drepanochir had neutral effects. In contrast, the putatively-introduced gammaridean amphipod, Ampithoe valida, had strong negative effects on eelgrass (in addition to epiphytes through consumption, as we had previously observed in the field during restoration programs. We tested whether other common grazer species could influence the effects of the eelgrass-grazing Ampithoe, and found that Idotea induced production of phenolic compounds and limited eelgrass damage by Ampithoe, without affecting Ampithoe abundance. These results have implications for restoration strategies, and contribute to a growing awareness of the importance of trait-mediated indirect grazer interactions through grazer-induced changes in plant traits, providing the first example in a seagrass system.

  7. Convergencia y televisión: retos del legislador

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    Lic. Alberto Pérez Gómez


    Full Text Available El proceso de convergencia entre los medios de comunicación, las telecomunicaciones y las tecnologías de la información que está teniendo lugar en la actualidad abre un nuevo mundo de posibilidades, pero el resultado del proceso no depende sólo de los aspectos técnicos, sino también en buena medida de la postura que adopte el legislador. Los cambios que introduce este proceso de convergencia en el sector de la televisión hacen que muchas de las normas existentes pasen a ser obsoletas. El legislador está obligado, en primer lugar, a analizar cuáles son las implicaciones sociales, culturales, técnicas y económicas del proceso de convergencia sobre la televisión, para poder así a continuación dar cumplida respuesta a los nuevos retos que se le plantean: el control de los contenidos, la redefinición del servicio público, el control de la concentración empresarial, la garantía del derecho de acceso de los ciudadanos, la concesión de licencias, la transición del sistema analógico al digital, la creación de autoridades independientes en esta materia...

  8. Ophidascaris wangi sp. n. and O. najae (Gedoelst, 1916) (Ascaridida: Ascaridoidea) from snakes in China. (United States)

    Li, Liang; Guo, Yan-Ning; Li, Jian; Zhang, Lu-Ping


    Ophidascaris wangi sp. n. collected from the king rat snake Elaphe carinata (Günther) (Serpentes: Colubridae) in China is described using both light and scanning electron microscopy. The new species differs from its congeners in the presence of narrow lateral alae originating a short distance posterior to the base of the ventrolateral lips, its relatively long oesophagus (3.57-4.54 mm long, representing 6.6-7.6% of body length), its short spicules (1.89-2.14 mm long, representing 3.9-4.3% of body length), the number and arrangement of caudal papillae (49-57 pairs in total, arranged as follows: 43-51 pairs precloacal, 2 pairs joined paracloacal and 4 pairs postcloacal), the presence of a particular papilliform medioventral, postcloacal ornamentation and the morphology of the eggs and tip of the female tail. In addition, Ophidascaris najae (Gedoelst, 1916), collected from the king cobra Ophiophagus hannah Cantor (Serpentes: Elapidae) in China, is also redescribed. The morphology of the cervical papillae, labial denticles and phasmids of the female is described for the first time.

  9. Molecular Identification of Cryptosporidium Species from Pet Snakes in Thailand. (United States)

    Yimming, Benjarat; Pattanatanang, Khampee; Sanyathitiseree, Pornchai; Inpankaew, Tawin; Kamyingkird, Ketsarin; Pinyopanuwat, Nongnuch; Chimnoi, Wissanuwat; Phasuk, Jumnongjit


    Cryptosporidium is an important pathogen causing gastrointestinal disease in snakes and is distributed worldwide. The main objectives of this study were to detect and identify Cryptosporidium species in captive snakes from exotic pet shops and snake farms in Thailand. In total, 165 fecal samples were examined from 8 snake species, boa constrictor (Boa constrictor constrictor), corn snake (Elaphe guttata), ball python (Python regius), milk snake (Lampropeltis triangulum), king snake (Lampropeltis getula), rock python (Python sebae), rainbow boa (Epicrates cenchria), and carpet python (Morelia spilota). Cryptosporidium oocysts were examined using the dimethyl sulfoxide (DMSO)-modified acid-fast staining and a molecular method based on nested-PCR, PCR-RFLP analysis, and sequencing amplification of the SSU rRNA gene. DMSO-modified acid-fast staining revealed the presence of Cryptosporidium oocysts in 12 out of 165 (7.3%) samples, whereas PCR produced positive results in 40 (24.2%) samples. Molecular characterization indicated the presence of Cryptosporidium parvum (mouse genotype) as the most common species in 24 samples (60%) from 5 species of snake followed by Cryptosporidium serpentis in 9 samples (22.5%) from 2 species of snake and Cryptosporidium muris in 3 samples (7.5%) from P. regius.

  10. Evidence of IgY subclass diversification in snakes: evolutionary implications. (United States)

    Wang, Tao; Sun, Yi; Shao, Wenwei; Cheng, Gang; Li, Lingxiao; Cao, Zubing; Yang, Zhi; Zou, Huiying; Zhang, Wei; Han, Binyue; Hu, Yang; Ren, Liming; Hu, Xiaoxiang; Guo, Ying; Fei, Jing; Hammarström, Lennart; Li, Ning; Zhao, Yaofeng


    Mammalian IgG and IgE are thought to have evolved from IgY of nonmammalian tetrapods; however, no diversification of IgY subclasses has been reported in reptiles or birds, which are phylogenetically close to mammals. To our knowledge, we report the first evidence of the presence of multiple IgY-encoding (υ) genes in snakes. Two υ genes were identified in the snake Elaphe taeniura, and three υ genes were identified in the Burmese python (Python molurus bivittatus). Although four of the υ genes displayed a conventional four-H chain C region exon structure, one of the υ genes in the Burmese python lacked the H chain C region 2 exon, thus exhibiting a structure similar to that of the mammalian γ genes. We developed mouse mAbs specific for the IgY1 and IgY2 of E. taeniura and showed that both were expressed in serum; each had two isoforms: one full-length and one truncated at the C terminus. The truncation was not caused by alternative splicing or transcriptional termination. We also identified the μ and δ genes, but no α gene, in both snakes. This study provides valuable clues for our understanding of Ig gene evolution in tetrapods.

  11. Odorous and non-fatal skin secretion of adult wrinkled frog (Rana rugosa is effective in avoiding predation by snakes.

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    Yuri Yoshimura

    Full Text Available The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes' responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes.

  12. Spatial complexity of carcass location influences vertebrate scavenger efficiency and species composition. (United States)

    Smith, Joshua B; Laatsch, Lauren J; Beasley, James C


    Scavenging plays an important role in shaping communities through inter- and intra-specific interactions. Although vertebrate scavenger efficiency and species composition is likely influenced by the spatial complexity of environments, heterogeneity in carrion distribution has largely been disregarded in scavenging studies. We tested this hypothesis by experimentally placing juvenile bird carcasses on the ground and in nests in trees to simulate scenarios of nestling bird carrion availability. We used cameras to record scavengers removing carcasses and elapsed time to removal. Carrion placed on the ground was scavenged by a greater diversity of vertebrates and at > 2 times the rate of arboreal carcasses, suggesting arboreal carrion may represent an important resource to invertebrate scavengers, particularly in landscapes with efficient vertebrate scavenging communities. Nonetheless, six vertebrate species scavenged arboreal carcasses. Rat snakes (Elaphe obsolete), which exclusively scavenged from trees, and turkey vultures (Cathartes aura) were the primary scavengers of arboreal carrion, suggesting such resources are potentially an important pathway of nutrient acquisition for some volant and scansorial vertebrates. Our results highlight the intricacy of carrion-derived food web linkages, and how consideration of spatial complexity in carcass distribution (i.e., arboreal) may reveal important pathways of nutrient acquisition by invertebrate and vertebrate scavenging guilds.

  13. Does Sexual Selection Influence Ornamentation of Hemipenes in Old World Snakes? (United States)

    Andonov, Kostadin; Natchev, Nikolay; Kornilev, Yurii V; Tzankov, Nikolay


    In the present study, we investigated and documented the morphology of the male copulatory organs (hemipenes) in fifteen wide-ranging snake species. The species represent four families (Boidae, Colubridae, Lamprophiidae, and Viperidae) and ten genera. We applied the same preparation techniques for all species, successfully everting and expanding the organs completely. The detailed description of the general morphology of the male copulatory organs was based on 31 specimens. Our data were compared with published observations and we point out some incorrectly described details in previous investigations. We provide the first description of the hemipenial morphology for three ophidian species (Elaphe sauromates, Telescopus fallax, and Malpolon insignitus). In addition to the morphological characteristics of the hemipenes presented in the research, we propose the adoption of a standardized index describing the hemipenial proportions. The immense variation in hemipenial morphology presupposes its dynamic evolution, but we suggest that many of the significant structures observed here may have escaped previous researchers due to differing methodologies. Some of the highly ornamented morphologies that we describe are consistent with a locking mechanism during copulation. However, other morphologies may relate to the variety of mating behaviors observed. As a result, we propose that sexual selection is the major driver affecting the hemipenial ornamentation in snakes. Anat Rec, 300:1680-1694, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Odorous and non-fatal skin secretion of adult wrinkled frog (Rana rugosa) is effective in avoiding predation by snakes. (United States)

    Yoshimura, Yuri; Kasuya, Eiiti


    The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa) has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes' responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping) behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes.

  15. Spatial Distribution and a Retrospective Analysis of the Herpetofauna in the City of Plovdiv, Bulgaria

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    Ivelin A. Mollov


    Full Text Available The current study presents the contemporary status and distribution of theamphibians and reptiles in the city of Plovdiv. To track changes in the status ofamphibians and reptiles in the research area through time, a retrospective analysis wasmade based on available literary data. During the past 100 years four species ofamphibians (Triturus karelinii, Lissotriton vulgaris, Bombina bombina, B. variegata and fourspecies of reptiles (Coronella austriaca, Zamenis longissimus, Elaphe sauromates, Viperaammodytes probably have disappeared from the study area; one amphibian species (Bufobufo and one reptile (Natrix natrix have not changed their status, one amphibian(Pelobates syriacus and two reptile species (Ablepharus kitaibelii, Podarcis muralis havereduced their localities and four amphibian species (Epidalea viridis, Rana dalmatina,Pelophylax ridibundus, Hyla arborea and seven species of reptiles (Mediodactylus kotschyi,Lacerta trilineata, Lacerta viridis, Podarcis tauricus, Emys orbicularis, Dolichophis caspius,Natrix tessellata have increased their localities and frequency of occurrence. The recordsof the two tortoise species (Testudo hermanni and T. graeca in the city, and the presence ofthe Red-eared slider (Trachemys scripta elegans should be considered as accidental.Important Herpetological Areas (IHA in the study region are also identified.

  16. Identification of the linkage group of the Z sex chromosomes of the sand lizard (Lacerta agilis, Lacertidae) and elucidation of karyotype evolution in lacertid lizards. (United States)

    Srikulnath, Kornsorn; Matsubara, Kazumi; Uno, Yoshinobu; Nishida, Chizuko; Olsson, Mats; Matsuda, Yoichi


    The sand lizard (Lacerta agilis, Lacertidae) has a chromosome number of 2n = 38, with 17 pairs of acrocentric chromosomes, one pair of microchromosomes, a large acrocentric Z chromosome, and a micro-W chromosome. To investigate the process of karyotype evolution in L. agilis, we performed chromosome banding and fluorescent in situ hybridization for gene mapping and constructed a cytogenetic map with 86 functional genes. Chromosome banding revealed that the Z chromosome is the fifth largest chromosome. The cytogenetic map revealed homology of the L. agilis Z chromosome with chicken chromosomes 6 and 9. Comparison of the L. agilis cytogenetic map with those of four Toxicofera species with many microchromosomes (Elaphe quadrivirgata, Varanus salvator macromaculatus, Leiolepis reevesii rubritaeniata, and Anolis carolinensis) showed highly conserved linkage homology of L. agilis chromosomes (LAG) 1, 2, 3, 4, 5(Z), 7, 8, 9, and 10 with macrochromosomes and/or macrochromosome segments of the four Toxicofera species. Most of the genes located on the microchromosomes of Toxicofera were localized to LAG6, small acrocentric chromosomes (LAG11-18), and a microchromosome (LAG19) in L. agilis. These results suggest that the L. agilis karyotype resulted from frequent fusions of microchromosomes, which occurred in the ancestral karyotype of Toxicofera and led to the disappearance of microchromosomes and the appearance of many small macrochromosomes.

  17. Karyotype Reorganization in the Hokou Gecko (Gekko hokouensis, Gekkonidae: The Process of Microchromosome Disappearance in Gekkota.

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    Kornsorn Srikulnath

    Full Text Available The Hokou gecko (Gekko hokouensis: Gekkonidae, Gekkota, Squamata has the chromosome number 2n = 38, with no microchromosomes. For molecular cytogenetic characterization of the gekkotan karyotype, we constructed a cytogenetic map for G. hokouensis, which retains the ancestral karyotype of Gekkota, with 86 functional genes, and compared it with cytogenetic maps for four Toxicofera species that have many microchromosomes (Elaphe quadrivirgata, Varanus salvator macromaculatus, Leiolepis reevesii rubritaeniata, and Anolis carolinensis and that for a lacertid species (Lacerta agilis with only one pair of autosomal microchromosomes. Ten pairs of G. hokouensis chromosomes [GHO1, 2, 3, Z(4, 6, 7, 8, 13, 14, and 15] showed highly conserved linkage homology with macrochromosomes and/or macrochromosome arms of the four Toxicofera species and corresponded to eight L. agilis macrochromosomes (LAG. However, GHO5, GHO9, GHO10, GHO11, and LAG6 were composed of chromosome segments that have a homology with Toxicofera microchromosomes, and no homology was found in the chromosomes between G. hokouensis and L. agilis. These results suggest that repeated fusions of microchromosomes may have occurred independently in each lineage of Gekkota and Lacertidae, leading to the disappearance of microchromosomes and appearance of small-sized macrochromosomes.

  18. Karyotype Reorganization in the Hokou Gecko (Gekko hokouensis, Gekkonidae): The Process of Microchromosome Disappearance in Gekkota. (United States)

    Srikulnath, Kornsorn; Uno, Yoshinobu; Nishida, Chizuko; Ota, Hidetoshi; Matsuda, Yoichi


    The Hokou gecko (Gekko hokouensis: Gekkonidae, Gekkota, Squamata) has the chromosome number 2n = 38, with no microchromosomes. For molecular cytogenetic characterization of the gekkotan karyotype, we constructed a cytogenetic map for G. hokouensis, which retains the ancestral karyotype of Gekkota, with 86 functional genes, and compared it with cytogenetic maps for four Toxicofera species that have many microchromosomes (Elaphe quadrivirgata, Varanus salvator macromaculatus, Leiolepis reevesii rubritaeniata, and Anolis carolinensis) and that for a lacertid species (Lacerta agilis) with only one pair of autosomal microchromosomes. Ten pairs of G. hokouensis chromosomes [GHO1, 2, 3, Z(4), 6, 7, 8, 13, 14, and 15] showed highly conserved linkage homology with macrochromosomes and/or macrochromosome arms of the four Toxicofera species and corresponded to eight L. agilis macrochromosomes (LAG). However, GHO5, GHO9, GHO10, GHO11, and LAG6 were composed of chromosome segments that have a homology with Toxicofera microchromosomes, and no homology was found in the chromosomes between G. hokouensis and L. agilis. These results suggest that repeated fusions of microchromosomes may have occurred independently in each lineage of Gekkota and Lacertidae, leading to the disappearance of microchromosomes and appearance of small-sized macrochromosomes.

  19. The behavioral responses of amphibians and reptiles to microgravity on parabolic flights. (United States)

    Wassersug, Richard J; Roberts, Lesley; Gimian, Jenny; Hughes, Elizabeth; Saunders, Ryan; Devison, Darren; Woodbury, Jonathan; O'Reilly, James C


    In the present study, we exposed 53 animals from 23 different species of amphibians and reptiles to microgravity (mug). This nearly doubles the number of amphibians and reptiles observed so far in mug. The animals were flown on a parabolic flight, which provided 20-25s of mug, to better characterize behavioral reactions to abrupt exposure to mug. Highly fossorial limbless caecilians and amphisbaenians showed relatively limited movement in mug. Limbed quadrupedal reptiles that were non-arboreal in the genera Leiocephalus, Anolis, and Scincella showed the typical righting response and enormous amounts of body motion and tail rotation, which we interpreted as both righting responses and futile actions to grasp the substrate. Both arboreal and non-arboreal geckos in the genera Uroplatus, Palmatogecko, Stenodactylus, Tarentola, and Eublepharis instead showed a skydiving posture previously reported for highly arboreal anurans. Some snakes, in the genera Thamnophis and Elaphe, which typically thrashed and rolled in mug, managed to knot their own bodies with their tails and immediately became quiescent. This suggests that these reptiles gave stable physical contact, which would indicate that they were not falling, primacy over vestibular input that indicated that they were in freefall. The fact that they became quiet upon self-embrace further suggests a failure to distinguish self from non-self. The patterns of behavior seen in amphibians and reptiles in mug can be explained in light of their normal ecology and taxonomic relations.

  20. Diversidad y distribución de mariposas Satyrinae (Lepidoptera: Nymphalidae en la cuenca del río Coello, Colombia

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    Jack F García-Perez


    Full Text Available Este estudio describe los patrones de diversidad y distribución de la subfamilia Satyrinae en la cuenca del río Coello (4º 17’ 08’’ N y 74º 35´ 36" W; 1 899.31 km², en un gradiente altitudinal de 433 a 3 600 m.s.n.m, con el fin de determinar la diversidad y composición regional y local de este grupo de mariposas y su posible uso como indicador biológico de zonas montanas y de Páramo. Se establecieron 11 estaciones de muestreo las cuales incluyen distintas zonas de vida. Las muestras se recolecciónron durante un periodo de 11 días en marzo, mayo, julio y octubre de 2003, en tres tipos de hábitat (bosque, borde de bosque y pradera. La recolección fue al azar en transectos de longitud no definida, entre las 09:00 y las 15:00 hr, empleando para ello redes lepidopterológicas de 0.5 m de diámetro y 1.20 m de longitud. Para el análisis de datos se calculó el índice de riqueza de Margalef (D y se registró el porcentaje de abundancia relativa para las especies. La diversidad total por localidad y por hábitat se analizó a través del índice de Shannon (H’. De las matrices de presencia-ausencia se obtuvo índices de similitud entre estaciones, según coeficiente de Jaccard. Se recolectó un total de 239 individuos de 13 géneros y 34 especies. Las especies más abundantes fueron especialmente del género Pedaliodes, representando el 41.4%. La riqueza y diversidad, presentaron un comportamiento similar, mostrando altos valores en zonas montanas y de Páramo (> 2000 m.s.n.m. En cuanto a la diversidad por hábitat, se observó la mayor diversidad en el borde de bosque. El análisis de similitud evidenció dos grupos claramente definidos. El primer grupo contempla especies propias de zonas cálidas (Euptychia hesione y Hermeuptychia hermes y templadas (Pseudohaetera hypaesia y Taygetis celia, mientras el segundo presenta especies exclusivas de zonas montanas y de Páramo (Lymanopoda obsoleta, Pedaliodes polusca y Eretris calisto

  1. La fauna del pleistoceno inferior de la Sierra de Quibas (Abanilla, Murcia

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    Szyndlar, Z.


    Full Text Available The Quaternary karstic site of Sierra de Quibas (Abanilla, Murcia, Spain has provided a wide faunistic list with 53 species distributed among gastropods, myriapods, amphibians, reptiles, birds and mammals. Especially interesting among the gastropods is Palaeoglandina that became extinct in Europe during the Pliocene. It remains as a relict genus in the Pleistocene of the Iberian Peninsula. Two of the birds, Gypaetus barbatus and Geronticus eremita, and a snake, Elaphe cf. E. sealaris, are scarcely represented in the fossil record. For several birds, it is the first record in the Lower Pleistocene of the Iberian Peninsula. Among the mammals, the presence of the Cercopithecine Macaca sylvanus is especially relevant one. The assemblage of the taxa Arvicola deucalion, Castillomys rivas rivas, Eliomys intermedius, Equus altidens and Capra sp. aff. C. alba allows the correlation with Plines 1, Orce 3 and Venta Micena, among other sites. Therefore Quibas can be dated before the end of Lower Pleistocene, between 1.3 and 1 Ma. A dry paleoclimatic regime, very similar to the current climate in the geographical area, though perhaps slightly wetter and warmer, can be inferred from the faunistic assemblage. The environment of the karstic cavity was a rocky place with open brushwood areas, but in the proximities there were wetlands and woodlands, as can be inferred from the presence of birds and micromammals characteristic of these habitats.El yacimiento kárstico cuaternario de la Sierra de Quibas (Abanilla, Murcia ha proporcionado una amplia lista faunística constituida por 53 especies repartidas entre gasterópodos, miriápodos, anfibios, reptiles, aves y mamíferos. En el conjunto de los gasterópodos destaca Palaeoglandina, un género que se extingue en el resto de Europa durante el Plioceno y que se mantiene como relicto en el Pleistoceno de la Península Ibérica. Dos de las especies de aves determinadas, Gypaetus barbatus y Gerontieus eremita, y una

  2. Estado ecológico de algunos humedales colombianos en los últimos 15 años: una evaluación prospectiva

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    Juan Pablo Rodríguez


    Full Text Available Los humedales desempeñan un papel fundamental desde una perspectiva ecológica y socioeconómica. Contrario a la idea ya obsoleta de lugares insalubres y de poca productividad, hoy son considerados ecosistemas estratégicos, amortiguadores de crecientes, sitios especiales de conservación de biota y cruciales por los servicios ecosistémicos que prestan. Partiendo de una revisión bibliográfica referente al estado ecológico de los humedales en Colombia en los últimos 15 años, se analizó cuáles son los factores, problemáticas e impactos más frecuentes y comunes que se presentan en 29 humedales colombianos. Se aplicó una metodología prospectiva, mediante el software MICMAC®, con el fin de conocer y priorizar los factores que son más sensibles a la transformación del ecosistema y sobre los cuales habría que tomar acciones de mitigación, preservación y/o conservación. Se encontró que los procesos urbanísticos son un factor de alto impacto en el deterioro del humedal. Se pudo comprobar la potencialidad y robustez del software MICMAC® como herramienta de análisis prospectivo, lo cual podría ser usado por las autoridades ambientales para mejorar la toma de decisiones respecto a qué hacer, cómo actuar y qué esperar de los factores y problemáticas que se presentan en los humedales.

  3. Modernization of the subsystem man-machine interface for operation of the combined cycle central of Gomez Palacio; Modernizacion del subsistema de interfaz hombre-maquina para operacion de la central de ciclo combinado de Gomez Palacio

    Energy Technology Data Exchange (ETDEWEB)

    Rivas S, Alfonso; Uribe B, Carlos E; Alvarez C, Victor [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)


    In order to take care of the modernization of the Combined Cycle Central of Gomez Palacio (CCCGP) of the Comision Federal de Electricidad (CFE), the Instituto de Investigaciones Electricas (IIE), through the Management of Supervision of Processes (GSP) developed the subsystem of Interface Man-Machine (IMM), to replace the workstations that are deteriorated and obsolete by personal computers, maintaining the same functions of the IMM of the present system, including the management and processing functions that at the present time another system makes. Also, to replace the equipment of the concentrators of communications by a PC with greater capacity, than allows improving in general the flexibility and robustness of the system. Among the main functions integrated in the IMM subsystem there are: the communications master with the controllers (equipment SAC), redundancy of servers, database, historical registry storage, alarm management, tabulations, tendency graphs in real time and historical, process diagrams and Control Panels. [Spanish] Con el objeto de atender las necesidades de modernizacion de la Central de Ciclo Combinado Gomez Palacio (CCCGP) de la Comision Federal de Electricidad (CFE), el Instituto de Investigaciones Electricas (IIE), a traves de la Gerencia de Supervision de Procesos (GSP) desarrollo el subsistema de Interfaz Hmbre-Maquina (IHM), para reemplazar las estaciones de trabajo que se encuentran deterioradas y obsoletas por computadoras personales, manteniendo las mismas funciones de la IHM del sistema actual, incluyendo las funciones de administracion y procesamiento que en la actualidad realiza otro sistema. Asimismo, para reemplazar los equipos de los concentradores de comunicaciones por PC con mayor capacidad, que permitan mejorar la flexibilidad y robustez del sistema en general. Entre las principales funciones integradas en el subsistema de IHM se encuentran: el Maestro de comunicaciones con los controladores (equipo SAC), redundancia de

  4. Nuevo Mercado Nacional de Ganado

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    Sánchez de Dios, Alejandro


    Full Text Available The new National Livestock Market of Santiago de Compostela is the result of the need to move the present obsolete and badly located buildings to a new place which will have better access roads, better parking and circulation space for vehicles and more modem and complete installations. The complex is also meant to be a general purpose fairground. The article briefly describes the most important elements of the new installation, including the main 17,000 m2 building, with a laminated wood structure of a 53 m span, and the computer equipment which is one of the most complete ones in Europe in this type of installations.

    El nuevo Mercado Nacional de Ganado de Santiago de Compostela nace como consecuencia de la necesidad de trasladar las actuales edificaciones, obsoletas y mal ubicadas, a un nuevo recinto, que estará dotado de mejores accesos, mayor espacio para estacionamiento y circulación de vehículos y más modernas y completas instalaciones. Se pretende además que sirva como recinto ferial de carácter general. A lo largo del artículo se aborda una descripción somera de los elementos más significativos de la nueva instalación, desde la edificación principal, de 17.000 m2, con estructura de madera laminada de 53 m de luz, hasta el equipamiento informático, uno de los más completos de Europa en este tipo de instalaciones.

  5. La reestructuración de los recursos sanitarios dedicados a la salud ambiental en la Comunidad de Madrid (1989-1999

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    J. M. Ordóñez Iriarte


    Full Text Available La Salud Ambiental, en su acepción más amplia, que engloba lo que administrativamente se entiende por Sanidad Ambiental e Higiene Alimentaria, tradicionalmente estuvo desempeñada por los Titulares Farmacéuticos, Médicos y Veterinarios que ejercían sus funciones en el ámbito de las demarcaciones de Partidos. Sobre estas estructuras, creadas en el año 1953 han ido incidiendo a lo largo de los años distintos eventos de tipo técnico y político que han hecho necesaria su reestructuración para ser capaces de dar respuesta al conjunto de problemas que preocupan a la Salud Pública.En este trabajo se pretende describir el modelo de reestructuración de los Servicios Farmacéuticos y Veterinarios realizado en la Comunidad de Madrid, analizar este modelo de reestructuración y proponer un modelo de estos Servicios que pueda servir de paradigma a las Comunidades Autónomas que todavía no han abordado el proceso.La metodología usada es la del análisis de la situación antes y después de la reestructuración de los Servicios Veterinarios y Farmacéuticos realizada a través de sendos Decretos de la Comunidad de Madrid.Las estructuras de Partidos han quedado obsoletas por lo que la reestructuración de los recursos es una necesidad. El abordaje de esta reestructuración debe hacerse lejos de cualquier tentación corporativista y contemplando la posibilidad de incorporar otros profesionales distintos a los tradicionales dada la complejidad creciente de los problemas de Salud Ambiental.

  6. Prácticas basadas en la evidencia: pasado, presente y futuro

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    Alba Elisabeth Mustaca


    Full Text Available Las prácticas basadas en la evidencia (PBE y la subclase de ellas, los tratamientos con apoyo empírico (TAE, si bien su nomenclatura es reciente, tienen antecedentes remotos. Se presentan algunos hitos históricos sobre las PBE (pasado y sus antecedentes más próximos, los resultados de las primeras listas que aparecieron de prácticas psicoterapéuticas con apoyo empírico y su comparación con las últimas, como una manera sencilla de evaluar su desarrollo en la psicología clínica (presente. Finalmente, se presentarán algunas de las limitaciones que se deben superar (futuro. Respecto de las primeras listas de PBE, aumentaron las de fuerte apoyo empírico, se agregaron las subcategorías controvertidas y nocivas, presentan TAE para comorbilidades y algunas recomendaciones específicas para cada TAE en particular. Continúa el predominio de las terapias cognitivas-conductuales como las más válidas. Estos resultados muestran un avance considerable en el estudio sistemático de las PBE. En el futuro deberán incrementarse las PBE para comorbilidades, las investigaciones en otros países, las relaciones entre ciencia básica y tecnológica y disminuir la importante disociación que existe entre la investigación, tanto clínica como básica y la práctica profesional, como la cantidad de programas de psicología basados en escuelas psicológicas y bibliografías obsoletas.


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    Ignacio Santa Cruz


    Full Text Available Mondragón es hoy el séptimo grupo empresarial de España según la variablecifra de “ventas”, y el tercero de acuerdo con la variable “empleo”. Se trata de una cooperativaque ofrece una alternativa no capitalista cuyo éxito demuestra la posibilidadde transformación social, dejando obsoletas las Teorías de la Reproducción que defiendenque la educación no puede contribuir a superar las desigualdades sociales. Este artículoanaliza la relevancia que Mondragón ha otorgado a la educación a lo largo de másde 50 años, convirtiéndola en un elemento clave para su éxito y para la mejora de lascondiciones de vida de las personas que participan en esta experiencia.Mondragón is at present the seventh entrepreneurial group in Spain accordingto sales volume and the third according to employment. As a cooperative, it offers anon-capitalist alternative of success, demonstrating that social transformation is possibleand invalidating the theories of reproduction, which defend that education can not contributeto the overcoming of social inequalities. The present article analyses the importancegiven to education by Mondragón throughout its 50 years of history, making outof it a key factor both for the corporation’s success as well as for the improvement ofthe life condition of those who participate in this experience.

  8. Gestão documental da informação jurídica

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    Ana Cláudia Carvalho de Miranda

    Full Text Available Este artigo apresenta uma nova performance da gestão documental, voltada para o desenvolvimento das coleções no âmbito da informação jurídica, estabelecendo critérios de qualidade para os processos de seleção, aquisição e avaliação das informações. Para esse propósito, é feita uma avaliação das várias dimensões que permeiam a gestão documental da informação jurídica como um todo. A rapidez com que a informação jurídica se inova torna a literatura (ainda que recente ultrapassada e obsoleta, ocasionando, assim, uma maior dificuldade das bibliotecas permanecerem com suas publicações sempre atualizadas. Por isso, é preciso que sejam elaborados mecanismos de controle e que seja efetuado um bom desenvolvimento dos serviços prestados pelas mesmas. Esses mecanismos são criados por meio da política de desenvolvimento de coleções, pois, quando bem fundamentada, assegura o bibliotecário na tomada de decisões, tanto em relação ao processo de seleção, aquisição e descarte do acervo, como na sustentação da qualidade na atualização da coleção. O processo de desenvolvimento da coleção é visto sob o viés da abordagem sistêmica das organizações.

  9. Initiation and patterning of the snake dentition are dependent on Sonic hedgehog signaling. (United States)

    Buchtová, Marcela; Handrigan, Gregory R; Tucker, Abigail S; Lozanoff, Scott; Town, Liam; Fu, Katherine; Diewert, Virginia M; Wicking, Carol; Richman, Joy M


    Here we take the first look at cellular dynamics and molecular signaling in the developing snake dentition. We found that tooth formation differs from rodents in several respects. The majority of snake teeth bud off of a deep, ribbon-like dental lamina rather than as separate tooth germs. Prior to and after dental lamina ingrowth, we observe asymmetries in cell proliferation and extracellular matrix distribution suggesting that localized signaling by a secreted protein is involved. We cloned Sonic hedgehog from the African rock python Python sebae and traced its expression in the species as well as in two other snakes, the closely-related Python regius and the more derived corn snake Elaphe guttata (Colubridae). We found that expression of Shh is first confined to the odontogenic band and defines the position of the future dental lamina. Shh transcripts in pythons are progressively restricted to the oral epithelium on one side of the dental lamina and remain in this position throughout the prehatching period. Shh is expressed in the inner enamel epithelium and the stellate reticulum of the tooth anlagen, but is absent from the outer enamel epithelium and its derivative, the successional lamina. This suggests that signals other than Shh are responsible for replacement tooth formation. Functional studies using cyclopamine to block Hh signaling during odontogenesis prevented initiation and extension of the dental lamina into the mesenchyme, and also affected the directionality of this process. Further, blocking Hh signaling led to disruptions of the inner enamel epithelium. To explore the role of Shh in lamina extension, we looked at its expression in the premaxillary teeth, which form closer to the oral surface than elsewhere in the mouth. Oral ectodermal Shh expression in premaxillary teeth is lost soon after the teeth form reinforcing the idea that Shh is controlling the depth of the dental lamina. In summary, we have found diverse roles for Shh in patterning the

  10. Intra-genomic GC heterogeneity in sauropsids: evolutionary insights from cDNA mapping and GC3 profiling in snake (United States)


    Background Extant sauropsids (reptiles and birds) are divided into two major lineages, the lineage of Testudines (turtles) and Archosauria (crocodilians and birds) and the lineage of Lepidosauria (tuatara, lizards, worm lizards and snakes). Karyotypes of these sauropsidan groups generally consist of macrochromosomes and microchromosomes. In chicken, microchromosomes exhibit a higher GC-content than macrochromosomes. To examine the pattern of intra-genomic GC heterogeneity in lepidosaurian genomes, we constructed a cytogenetic map of the Japanese four-striped rat snake (Elaphe quadrivirgata) with 183 cDNA clones by fluorescence in situ hybridization, and examined the correlation between the GC-content of exonic third codon positions (GC3) of the genes and the size of chromosomes on which the genes were localized. Results Although GC3 distribution of snake genes was relatively homogeneous compared with those of the other amniotes, microchromosomal genes showed significantly higher GC3 than macrochromosomal genes as in chicken. Our snake cytogenetic map also identified several conserved segments between the snake macrochromosomes and the chicken microchromosomes. Cross-species comparisons revealed that GC3 of most snake orthologs in such macrochromosomal segments were GC-poor (GC3 < 50%) whereas those of chicken orthologs in microchromosomes were relatively GC-rich (GC3 ≥ 50%). Conclusion Our results suggest that the chromosome size-dependent GC heterogeneity had already occurred before the lepidosaur-archosaur split, 275 million years ago. This character was probably present in the common ancestor of lepidosaurs and but lost in the lineage leading to Anolis during the diversification of lepidosaurs. We also identified several genes whose GC-content might have been influenced by the size of the chromosomes on which they were harbored over the course of sauropsid evolution. PMID:23140509

  11. Molecular evidence of Sarcocystis species in captive snakes in Japan. (United States)

    Abe, Niichiro; Matsubara, Katsuki; Tamukai, Kenichi; Miwa, Yasutsugu; Takami, Kazutoshi


    Sarcocystis nesbitti, using snakes as the definitive host, is a causative agent of acute human muscular sarcocystosis in Malaysia. Therefore, it is important to explore the distribution and prevalence of S. nesbitti in snakes. Nevertheless, epizootiological information of S. nesbitti in snakes remains insufficient because few surveys have assessed Sarcocystis infection in snakes in endemic countries. In Japan, snakes are popular exotic pet animals that are imported from overseas, but the degree of Sarcocystis infection in them remains unclear. The possibility exists that muscular sarcocystosis by S. nesbitti occurs in contact with captive snakes in non-endemic countries. For a total of 125 snake faecal samples from 67 snake species collected at animal hospitals, pet shops and a zoo, this study investigated the presence of Sarcocystis using polymerase chain reaction (PCR) for the 18S ribosomal RNA gene (18S rDNA). Four (3.2%) faecal samples were positive by PCR. Phylogenetic analysis of the 18S rDNA sequences obtained from four amplification products revealed one isolate from a beauty snake (Elaphe taeniura), Sarcocystis zuoi, which uses rat snakes as the definitive host. The isolate from a Macklot's python (Liasis mackloti) was closely related with unidentified Sarcocystis sp. from reticulated pythons in Malaysia. The remaining two isolates from tree boas (Corallus spp.) were closely related with Sarcocystis lacertae, Sarcocystis gallotiae and unidentified Sarcocystis sp. from smooth snakes, Tenerife lizards and European shrews, respectively. This report is the first of a study examining the distribution of Sarcocystis species in captive snakes in Japan.

  12. Tetrathyridia of Mesocestoides lineatus in Chinese Snakes and Their Adults Recovered from Experimental Animals (United States)

    Cho, Shin-Hyeong; Kim, Tong-Soo; Kong, Yoon; Na, Byoung-Kuk


    Morphological characteristics of Mesocestoides lineatus tetrathyridia collected from Chinese snakes and their adults recovered from experimental animals were studied. The tetrathyridia were detected mainly in the mesentery of 2 snake species, Agkistrodon saxatilis (25%) and Elaphe schrenckii (20%). They were 1.73 by 1.02 mm in average size and had an invaginated scolex with 4 suckers. Adult tapeworms were recovered from 2 hamsters and 1 dog, which were orally infected with 5-10 larvae each. Adults from hamsters were about 32 cm long and those from a dog were about 58 cm long. The scolex was 0.56 mm in average width with 4 suckers of 0.17 by 0.15 mm in average size. Mature proglottids measured 0.29 by 0.91 mm (av.). Ovaries and vitellaria bilobed and located in the posterior portion of proglottids. The cirrus sac was oval-shaped and located median. Testes were follicular, distributed in both lateral fields of proglottids, and 41-52 in number per proglottid. Gravid proglottids were 1.84 by 1.39 mm (av.) with a characteristic paruterine organ. Eggs were 35 by 27 µm in average size with a hexacanth embryo. These morphological characteristics of adult worms were identical with those of M. lineatus reported previously. Therefore, it has been confirmed that the tetrathyridia detected in 2 species of Chinese snakes are the metacestodes of M. lineatus, and 2 snake species, A. saxatilis and E. schrenckii, play the role of intermediate hosts. PMID:24327778

  13. Transferencia de recursos económico financieros e impactos territoriales en Venezuela. Caso de estudio: Región Zuliana vs. Región Capital

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    Belén García


    Full Text Available El análisis de los efectos territoriales de la generación, captación y, sobre todo, asignación de los recursos económico-financieros en dos regiones venezolanas, Zulia y Capital, constituyen el objeto de análisis de este artículo. Los recursos económico-financieros constituyen el punto a partir del cual se analizan los desequilibrios interregionales, dado que son ellos, por una parte, los que soportan, impulsan, promueven o en su defecto limitan y detienen el proceso de desarrollo regional, reforzado por la ausencia o débil presencia de un verdadero liderazgo sociopolítico regional, así como una anacrónica y obsoleta gerencia públicaThis paper achieves an analysis of the unbalances between different regions, starting with the analysis of some variables of the financial system, viewed as the sector through which the transfer of the economic surplus produced by one region to another represents the benefits for some regions and the sacrifice the of other. In this analysis, two regions are analysed, one is the exporter region and the other one is the importer of economics and financial resources: the first one is the Zulia region, and the other is the Capital region. These unbalanced conditions are revealed in different ways. Thereby, we find that the "importer" region has higher rates of growth, higher levels of income, lower rates of unemployment, and higher rates of capital/product, etc. On the other hand we find that the "exporter" region has higher levels of stalemate. The first point to be analyzed are the unbalanced conditions in the analysis of the economical and financial resources, because we begin with the premise that resources support, promote or the other hand, limit and stop the process of development of the region. The importance of the analysis is to know and define the causes that originate unbalanced conditions in order to design corrective actions in order to find a more balanced regional structure and with higher

  14. Abordagem atual dos pacientes com doença de Hodgkin Current approach to patients with Hodgkin's disease

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    Nelson Spector


    Full Text Available Nos últimos anos, houve um progresso substancial na abordagem do paciente com doença de Hodgkin. Uma nova classificação histopatológica foi adotada, e fatores prognósticos reprodutíveis foram identificados. Os pacientes são tratados de acordo com o estádio clínico e, no caso de pacientes com doença localizada, também de acordo com os fatores prognósticos. Uma consistente série de estudos em pacientes com doença localizada tornou obsoleta a realização de laparotomia e a abordagem radioterápica isolada. Nos pacientes com doença avançada, o ABVD emergiu como o regime com a melhor relação risco/benefício após uma dura seqüência de comparações com o MOPP e combinações de MOPP e ABVD. Dois regimes inovadores estão em testes, o Stanford V e o BEACOPP. Entretanto, o avanço dos resultados terapêuticos depende da redução da toxicidade nos pacientes de baixo risco e da melhora do controle da doença nos pacientes de alto risco.In recent years, significant progress has been made in the approach to the patient with Hodgkin's disease. A new histopathologic classification has been adopted and reproducible prognostic factors have been recognized. Patients are treated according to their clinical stage and, in patients with early-stage disease, also according to their prognostic factors. A consistent sequence of studies in patients with early-stage disease has made laparotomy followed by radiation therapy obsolete. In patients with advanced disease, ABVD emerged as the regimen with the best risk/benefit ratio after a hard series of direct comparisons against MOPP and combinations of MOPP and ABVD. Two innovative regimens, Stanford V and BEACOPP, are currently undergoing a thorough evaluation. However, the improvement of treatment outcome is ultimately dependent on reducing the therapy-related toxicity for patients with low-risk disease, while improving disease control for patients with poor-risk disease through a risk


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    María Marcos Ramos


    Full Text Available A debate opened on the use in these moments of named TIC in the classroom. We must not forget the great value that in all of them has the image. Probably many people think that the cinema and the television already are not new technologies, but without seizure the majority of these new technologies - today qualified like new but they will be considered to be obsolete in a little time - they are based on the use of the image. We should form, therefore, our pupils in the conscious and effective use of this one. We should be able to take advantage of his potential in the classroom since it is a resource which we can have with relative facility and which continues being, the image and for extension his use in the mass media, one of the most important agents of socialization. Of the good use that our pupils do of the image and of the mass media, two of the more important instruments of mediation, his socialization and education depends, largely.Se plantea en estos momentos un debate abierto sobre el uso de las denominadas TICs en el aula. No debemos olvidar el gran valor que en todas ellas tiene la imagen. Quizá muchos consideren que el cine y la televisión ya no son nuevas tecnologías, pero sin embargo la mayoría de estas nuevas tecnologías –hoy calificadas como nuevas pero probablemente consideradas obsoletas en poco tiempo- se basan en el uso de la imagen. Deberíamos, por tanto, formar a nuestros alumnos en el uso consciente y eficaz de ésta. Deberíamos saber aprovechar su potencial en el aula, ya que es un recurso del que podemos disponer con relativa facilidad y que sigue siendo, la imagen y por extensión su uso en los medios de comunicación, uno de los más importantes agentes socializadores. Del buen uso que nuestros alumnos hagan de la imagen y de los medios de comunicación, dos de los instrumentos de mediación más importantes, depende, en gran parte, su socialización y educación.

  16. La investigación histórica y el debate actual sobre la salud masculina: el caso de Alemania

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    Dinges, Martin


    Full Text Available The current discourse on men’s health refers too insistently to an obsolete and monolithic pattern of masculinity contrasting “men” with “women” in a simplistic manner. However, historical analysis shows the remarkable changes that have occurred in the health of men, both in terms of their attitudes and their behaviors, since the industrial revolution; so, for example, the relationship between masculinity and risk behavior throughout life, the professional life and the world of work, and also the medical evaluation of certain high-risk behaviors such as smoking. Differences of the life expectancy between men and women deserve an explanation more accurate and less simplistic. From a historical perspective of longue-durée, it is also a myth that men keep silent on matters of health.El discurso actual sobre la salud masculina remite con demasiada insistencia a una imagen obsoleta y monolítica de la masculinidad contrastando de manera simplista el colectivo “hombres” con el de las “mujeres”. Sin embargo, el análisis histórico hace muy evidentes los notables cambios que se han producido en la salud de los hombres, tanto en lo que se refiere a sus actitudes como a sus comportamientos, desde la revolución industrial; así, por ejemplo, se ha transformado no solamente la vida profesional y el mundo del trabajo, sino también la relación entre la masculinidad y el comportamiento de riesgo a lo largo de la vida y, asimismo, la evaluación médica de ciertos comportamientos de alto riesgo como fumar. Las diferencias en la esperanza de vida entre hombres y mujeres merecen una explicación más precisa y menos simplista. Desde una perspectiva histórica de longue-durée, también es un mito que los hombres guarden silencio en asuntos de salud.


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    Dirección de Planificación Estratégic Institucional del ICE


    Full Text Available La elaboración y ejecución de las políticas monetarias y fiscales restrictivas en las dos últimas décadas en nuestro país, han afectado el correcto funcionamiento del ICE. Las metas que se plantean las autoridades monetarias y hacendarias año tras año, conllevan a una serie de restricciones en el ámbito presupuestario, limitándose el nivel de gastos corrientes, de inversiones y de endeudamiento de dicha institución. Con el argumento de que el ICE es parte del problema (cuando en realidad ha contribuido ha aminorarlo del desequilibrio en las finanzas públicas, se ha cercenado su autonomía e independencia; sin atacar la verdadera causa de dicho desbalance, tal y como son el déficit del gobierno central y de la autoridad monetaria.A nivel de las finanzas públicas, se incorporan las estadísticas del ICE bajo un formato contable que difiere de manera importante con los principios de la contabilidad que utilizan las empresas del sector privado. Dicha metodología es obsoleta, presentado serias deficiencias que el mismo FMI (quien la elaboró reconoce. Este mismo organismo ya ha elaborado una nueva metodología que aún no se utiliza en nuestro país. Más aún, existen países que utilizan metodologías diferentes, las cuales están mas acordes con la contabilidad tradicional de empresa privada.Los impactos positivos o negativos que la actuación del ICE pueda tener sobre el equilibrio macroeconómico, el crecimiento y el desarrollo del país, es algo aún no medido, cuyas relaciones de causa y efecto no se han establecido de manera real. En el debate y las discusiones, han prevalecido más bien las posturas políticas e ideológicas (en respuesta a intereses particulares, en detrimento del análisis científico y técnico. Así mismo, las discusiones se han fundamentado en postulados teóricos, sin ser contrarrestados contra la realidad.

  18. Um modelo evolucionário setorial

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    Mario L. Possas


    Full Text Available Este artigo apresenta um modelo evolucionário setorial de simulação que combina microfundamentos neo-schumpeterianos e pós-keynesianos e expõe alguns resultados preliminares das primeiras simulações. Estes resultados apontam, quanto a distintas condições do ambiente de mercado: o efeito positivo da taxa de crescimento da produtividade na fronteira tecnológica sobre a concentração de mercado; o efeito ambíguo do aprendizado, capaz de produzir um lock-in de firmas inovadoras pioneiras em tecnologias que se tornam eventualmente obsoletas; o efeito "anti-seletivo" de taxas de juros muito elevadas, endividando e prejudicando o esforço de investimento e o sucesso competitivo das inovadoras em benefício das imitadoras. Quanto à simulação das estratégias de preços, constatou-se: a maior seletividade de estratégias em que as firmas inovadoras dão mais peso ao mark-up desejado, gerando maior concentração de mercado, efeito que é atenuado pelo crescimento da demanda e pelo aprendizado; a importância, para a sobrevivência de empresas menos inovadoras, do feedback do desempenho competitivo sobre o mark-up desejado e o efetivo, aumentando a adaptabilidade das empresas às condições de seleção do mercado.This paper presents a sectoral evolutionary simulation model combining neo-Schumpeterian and Post-Keynesian microfoundations, and exhibits some preliminary results. As to different market environment conditions, the simulations suggest: a positive effect of productivity growth of the technological frontier on market concentration; an ambiguous result of "learning by doing", from which innovation leaders may be found "locked in" new technologies that eventually become obsolete; a "counter-selective" effect of very high interest rates which may increase innovators indebtedness to the extent of impairing their investment efforts and competitive success as compared to some imitators. As to different price strategies, major findings

  19. El Desarrollo de Viviendas de Interés Social y la Recuperación de Plusvalías en el Centro de Guayaquil: ¿Restricción u Oportunidad?

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    Alina Delgado Bohorquez


    Full Text Available La recuperación de los centros urbanos es una tarea a la que se han abocado los gobiernos de países de América Latina desde hace algunos años y que sigue a la tendencia implantada desde Europa y Estados Unidos. Los mayores costos del desarrollo periurbano y el elevado deterioro de los sectores centrales de las ciudades con la consecuente subutilización de recursos de infraestructura ha despertado un renovado interés por potencializar el desarrollo de estas áreas. En el corazón urbano de la ciudad de Guayaquil se encuentran importantes ejes viales como las calles Quito y Machala. Existen, sin embargo, a lo largo de estas vías solares vacíos, edificaciones obsoletas o en desuso, destinos comerciales no compatibles con la dinámica urbana, ausencia de áreas verdes e inseguridad. El objetivo del presente artículo fue analizar estrategias e instrumentos de gestión territorial que pudieran ser aplicables para la recuperación de plusvalías y el financiamiento de proyectos de vivienda social en el centro de Guayaquil. Se planteó la hipótesis de que a través de la utilización de estos instrumentos se podrían atraer inversiones al centro, y al mismo tiempo asegurar la inclusión de vivienda social, mejorar la calidad de los espacios públicos y contribuir a recuperar la memoria histórica del centro. La metodología utilizada surge de conceptualizaciones, estudio de casos y análisis de aplicabilidad de instrumentos de gestión para la renovación urbana del centro. Se concluye con una reflexión acerca de cómo las visiones diversas de la ciudad (la de las elites y de los grupos de menores ingresos pueden y deben ser integradas, por medio de la aplicación de instrumentos de recuperación de plusvalías enmarcados dentro de la discusión del derecho a la vivienda, la ciudad y a la función social de la propiedad.

  20. Modelling knowledge creation, investment decisions and economic growth in a spatial CGE setting

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    Francesco Di Comite


    Full Text Available La creación del conocimiento es habitualmente entendida como un vector clave de crecimiento económico. Mientras que la producción de conocimiento y el crecimiento económico han sido estudiados extensamente por separado, pocos estudios han intentado formalizar el mecanismo conectando los dos elementos desde la perspectiva de un modelo de equilibrio general espacial. Para rellenar este vacío, proponemos un modelo de creación de conocimiento aprovechando el modelo CGE multirregional RHOMOLO para la producción endógena de conocimientos y decisiones de inversión a nivel regional. El proceso de innovación se modeliza teniendo en cuenta la interacción entre investigadores, inversores y productores de bienes de consumo. Más en detalle, los investigadores en cada región usan su capital humano junto a activos que incorporan I+D y bienes intermedios para la producción de nuevas ideas, las cuales son mejoradas por la transferencia de conocimientos desde otras regiones. En la siguiente etapa, estas ideas son adquiridas por inversores locales y se combinan en el proceso de generar nuevos activos que incorporan I+D junto al capital humano y bienes intermedios, así aumentando el stock existente después de haber reemplazado la parte obsoleta. Por último, después del pago de los costes fijos de entrada, empresas regionales producen tanto bienes intermedios como bienes de consumo, alquilando capital humano y activos que incorporan I+D, combinándolos junto con un conjunto interregional de bienes intermedios en el proceso de producción, donde la disponibilidad de bienes y servicios públicos influye en su productividad. El modelo ha sido diseñado para ser calibrado con las versiones regionalizadas de matrices de contabilidad social, como son las que se pueden obtener de la base de datos World Input Output.

  1. Adiós al Vaticano II? Tres superaciones del Concilio Vaticano II

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    José María Vigil


    Full Text Available Resumen El autor confiesa que pertenece a la generación que ha dedicado su vida a implementar la herencia del Concilio Vaticano II, generación que ha tenido a ese concilio como el punto de referencia más importante - eclesialmente hablando - en los últimos 40 años. Sin embargo, aventura la hipótesis de que la problemática del Vaticano II ha quedado ya obsoleta, y lo justifica presentando tres olas de nuevos signos de los tiempos que han transformado radicalmente el panorama teológico y pastoral: la teología de la liberación, el pluralismo religioso y la crisis de la religión. El artículo trata de las grandes olas que avalan esa superación: la teología y la espiritualidad de la liberación, la teología del pluralismo religioso y la revisión de paradigma que provoca la actual crisis de la religión. Estas tres "superaciones" del Vaticano II son, pues, las que nos permiten pensar que lo que se dirimió en el Concilio ya no es el punto de referencia principal de la vida de la Iglesia, ni de las necesidades religiosas más urgentes de la Humanidad. Palabras clave: Concilio Vaticano II; Cambio de paradigma; Teología de la liberación; Pluralismo religioso; Crisis de la religión. Abstract The author belongs to the generation that has dedicated its life to implement the heritage of Vatican Council II, and has taken that Council as the most relevant point of reference, in ecclesiastical terms, for the last 40 years. However, he formulates the hypothesis that the problematics of Vatican II has become obsolete, and justifies that viewpoint presenting three new waves that have transformed radically the theological and pastoral panorama: the theology of liberation, religious pluralism and the crisis in religion. The article focuses on the signs that support such surpassing: the theology and spirituality of liberation, the theology of religious pluralism and the review of paradigms that has brought about the current crisis in religion

  2. Molecular insight into systematics, host associations, life cycles and geographic distribution of the nematode family Rhabdiasidae. (United States)

    Tkach, Vasyl V; Kuzmin, Yuriy; Snyder, Scott D


    Rhabdiasidae Railliet, 1915 is a globally distributed group of up to 100 known species of nematodes parasitic in amphibians and reptiles. This work presents the results of a molecular phylogenetic analysis of 36 species of Rhabdiasidae from reptiles and amphibians from six continents. New DNA sequences encompassing partial 18S rDNA, ITS1, 5.8S rDNA, ITS2 and partial 28S rDNA regions of nuclear ribosomal DNA were obtained from 27 species and pre-existing sequences for nine species were incorporated. The broad taxonomic, host and geographical coverage of the specimens allowed us to address long-standing questions in rhabdiasid systematics, evolution, geographic distribution, and patterns of host association. Our analysis demonstrated that rhabdiasids parasitic in snakes are an independent genus sister to the rest of the Rhabdiasidae, a status supported by life cycle data. Based on the combined evidence of molecular phylogeny, morphology and life cycle characteristics, a new genus Serpentirhabdias gen. nov. with the type species Serpentirhabdias elaphe (Sharpilo, 1976) comb. nov. is established. The phylogeny supports the monophyly of Entomelas Travassos, 1930, Pneumonema Johnston, 1916 and the largest genus of the family, Rhabdias Stiles and Hassall, 1905. DNA sequence comparisons demonstrate the presence of more than one species in the previously monotypic Pneumonema from Australian scincid lizards. The distribution of some morphological characters in the genus Rhabdias shows little consistency within the phylogenetic tree topology, in particular the apical structures widely used in rhabdiasid systematics. Our data suggest that some of the characters, while valuable for species differentiation, are not appropriate for differentiation among higher taxa and are of limited phylogenetic utility. Rhabdias is the only genus with a cosmopolitan distribution, but some of the lineages within Rhabdias are distributed on a single continent or a group of adjacent

  3. Grassland bird productivity in warm season grass fields in southwest Wisconsin (United States)

    Byers, Carolyn M.; Ribic, Christine; Sample, David W.; Dadisman, John D.; Guttery, Michael


    Surrogate grasslands established through federal set-aside programs, such as U.S. Department of Agriculture's Conservation Reserve Program (CRP), provide important habitat for grassland birds. Warm season grass CRP fields as a group have the potential for providing a continuum of habitat structure for breeding birds, depending on how the fields are managed and their floristic composition. We studied the nesting activity of four obligate grassland bird species, Bobolink (Dolichonyx oryzivorus), Eastern Meadowlark (Sturnella magna), Grasshopper Sparrow (Ammodramus savannarum), and Henslow's Sparrow (A. henslowii), in relation to vegetative composition and fire management in warm season CRP fields in southwest Wisconsin during 2009–2011. Intraspecific variation in apparent nest density was related to the number of years since the field was burned. Apparent Grasshopper Sparrow nest density was highest in the breeding season immediately following spring burns, apparent Henslow's Sparrow nest density was highest 1 y post burn, and apparent Bobolink and Eastern Meadowlark nest densities were higher in post fire years one to three. Grasshopper Sparrow nest density was highest on sites with more diverse vegetation, specifically prairie forbs, and on sites with shorter less dense vegetation. Bobolink, Eastern Meadowlark, and Henslow's Sparrow apparent nest densities were higher on sites with deeper litter; litter was the vegetative component that was most affected by spring burns. Overall nest success was 0.487 for Bobolink (22 d nesting period), 0.478 for Eastern Meadowlark (25 d nesting period), 0.507 for Grasshopper Sparrow (22 d nesting period), and 0.151 for Henslow's Sparrow (21 d nesting period). The major nest predators were grassland-associated species: thirteen-lined ground squirrel (Ictidomys tridecemlineatus), striped skunk (Mephitis mephitis), milk snake (Lampropeltis triangulum), American badger (Taxidea taxus), and western fox snake (Elaphe vulpina). Overall

  4. Catalogue of Tenebrionidae (Coleoptera of North America

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    Yves Bousquet


    angustula Casey, 1890, Stethasida stricta Casey, 1912, Stethasida muricatula languida Casey, 1912, Stethasida pertinax Casey, 1912, Stethasida socors Casey, 1912, Stethasida angustula inepta Casey, 1912, Stethasida tenax Casey, 1912, and Stethasida vegrandis Casey, 1912 [= Stenomorpha muricatula (LeConte, 1851]; Stethasida obsoleta expansa Casey, 1912, Stethasida obsoleta opacella Casey, 1912, Stethasida brevipes Casey, 1912, Stethasida torpida Casey, 1912, Stethasida convergens Casey, 1912, Stethasida discreta Casey, 1912, Stethasida longula Casey, 1912, Stethasida adumbrata Casey, 1912, Stethasida occulta Casey, 1912, Stethasida tarsalis Casey, 1912, Stethasida unica Casey, 1912, and Pelecyphorus laevigatus Papp, 1961 [= Stenomorpha obsoleta (LeConte, 1851]; Trichiasida eremica Wilke, 1922 [= Stenomorpha difficilis (Champion, 1884]; Trichiasida lineatopilosa Casey, 1912 [= Stenomorpha hirsuta (LeConte, 1851]; Trichiasida tenella Casey, 1912 [= Stenomorpha hispidula (LeConte, 1851]; Trichiasida duplex Casey, 1912 [= Stenomorpha villosa (Champion, 1884]; Alaudes squamosa Blaisdell, 1919, Alaudes testacea Blaisdell, 1919, and Alaudes fallax Fall, 1928 [= Alaudes singularis Horn, 1870]; Edrotes barrowsi Dajoz, 1999 [=Edrotes ventricosus LeConte, 1851]; Nyctoporis tetrica Casey, 1907 and Nyctoporis maura Casey, 1907 [= Nyctoporis aequicollis Eschscholtz, 1831]; Nyctoporis pullata Casey, 1907 [= Nyctoporis sponsa Casey, 1907]; Eleodes tibialis forma oblonga Blaisdell, 1909 [= Eleodes tibialis Blaisdell, 1909]; Eleodes (manni var. variolosa Blaisdell, 1917 [= Eleodes constrictus LeConte, 1858]; Eleodes cordata forma sublaevis Blaisdell, 1909, Eleodes cordata forma intermedia Blaisdell, 1909, Eleodes cordata forma oblonga Blaisdell, 1909, Eleodes cordata forma elongata Blaisdell, 1909, and Eleodes (cordata var. adulterina Blaisdell, 1917 [= Eleodes cordata Eschscholtz, 1829]; Eleodes hornii var. monticula Blaisdell, 1918 and Eleodes manni sierra Blaisdell, 1925 [= Eleodes fuchsii

  5. Stakeholder perceptions of decision-making process on marine biodiversity conservation on sal island (Cape Verde

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    Jorge Ramos


    e recifes (naturais e artificiais e recolhemos as expectativas dos utilizadores de RAs. Assim, foi elaborado um projecto teórico cujo objectivo é a conservação da biodiversidade marinha, no qual são propostas algumas medidas de gestão. Através da utilização do método designado por processo analítico hierárquico (PAH foi escrutinada a percepção dos utilizadores sobre as melhores práticas para a conservação da biodiversidade marinha na Ilha do Sal. Os resultados mostraram que o afundamento de estruturas obsoletas em áreas rochosas ou mistas parece ter um grande potencial, mas não é consensual. Em conclusão, a limitação de actividades de mergulho afigura-se como uma opção a considerar futuramente.

  6. Using biodiversity of diatoms to identify hydrological connectivity in the hillslope-riparian zone-stream system (United States)

    Wetzel, C. E.; Martínez-Carreras, N.; Ector, L.; Hlubikova, D.; Frentress, J.; McDonnell, J. J.; Hoffmann, L.; Pfister, L.


    very intense rainfall events cause a single-tailed rather small rise of the hydrograph in the Weierbach. Mixing diagrams suggest a very brief and intense switch from groundwater to soil water contribution. Almost simultaneously to incoming precipitation, terrestrial diatom abundance increases to 20-30% inside the stream. Species composition was also seasonally structured. During winter season (November 2010 and January 2011 events) the diatom drift was characterized and dominated by colony forming species (e.g. Fragilaria nevadensis Linares-Cuesta & Sánchez-Castillo and Fragilariforma virescens (Ralfs) Williams & Round), while summer events were characterized by a large number of small aerophytic species (i.e. Chamaepinnularia evanida (Hustedt) Lange-Bertalot, Eolimna tantula (Hustedt) Lange-Bertalot, Navicula obsoleta Hustedt, Navicula parsura Hustedt and Stauroneis thermicola (Petersen) Lund). Chemical tracers suggest a substantial role of soil water contributions to storm hydrographs in the Weierbach, regardless of the season, with overland flow playing no prominent role at all. Meanwhile, terrestrial diatom abundance in drift samples strongly increases during precipitation events, suggesting a rapid onset of connectivity between the soil surface and the stream. We assume the terrestrial diatoms to be mobilized during precipitation and eventually flushed to the stream through a subsurface network of macropores in the shallow soils and cracks in the fractured and weathered schistose bedrock.

  7. El ocaso del profesor Binns: Un ensayo acerca de la enseñanza del derecho en Chile

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    Rodrigo Coloma Correa


    Full Text Available La manera habitual de abordar la enseñanza el derecho en nuestro país presenta fuertes deficiencias sobre las que periódicamente distintos autores llaman la atención. En este artículo tales deficiencias son relacionadas con los currículos, la metodología de enseñanza y los mecanismos de evaluación de los aprendizajes. Una vez hecha la clarificación relativa al escenario ante el cual estamos operando, se exploran algunas de las razones que explicarían la relativamente sorprendente pervivencia de prácticas pedagógicas obsoletas, habida consideración de las competencias que serían esperables de parte de los recién licenciados en ciencias jurídicas. Además de plantearse argumentos tales como la carencia de un modelo educativo que pueda ser fácilmente visualizado como reemplazante del actualmente imperante, se sugiere que la resistencia al cambio estaría relacionada con una concepción de los estudiantes como recipientes a ser llenados, incapaces para negociar significados. Considerando que los futuros abogados debieran estar adecuadamente preparados para operar en una sociedad cambiante, lo que implica la capacidad de autoaprendizaje y el dominio de una serie de competencias que van más allá de la mera memorización de información, se sugieren cambios en la manera de abordar el proceso de enseñanza aprendizaje con miras a aprovechar adecuadamente las potencialidades de los estudiantes, lo que implica pasar a verlos como sujetos capaces para construir nuevos conocimientos y de hacerse cargo de los ya acumulados.The traditional way of teaching law in Chile presents grave deficiencies which are periodically analyzed by different authors. In this article, those deficiencies are related to the curricula, the teaching methodology and the mechanisms for assessing learning. Once the scenario is set, the reasons for the rather perplexing persistence of obsolete pedagogical practices are examined, in light of the competences to be

  8. Weberian versus Pluralistic Legal Forces in the Global Political Economy

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    Volkmar Gessner


    desde las formas tradicionales a las formas irracionales formales y burocráticas de dominación legal. Desde el punto de vista de Weber la racionalización jurídica es nuestro "destino" y las normas e instituciones informales necesariamente obsoleta serán examinadas de nuevo desde una perspectiva histórica y confrontadas con los datos empíricos recogidos en el ámbito del gobierno de las transacciones comerciales globales. En este artículo trataremos de mostrar que a pesar de que el enfoque influyente de Weber todavía ayuda a explicar gran parte de lo que ocurre en los modelos internos del capitalismo, no parece comprender la creciente complejidad del capitalismo globalizado.


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    Mayra Rosario Moreno Pino


    Full Text Available The Venezuelan university before the Bolivarian Revolution was characterized by institutional behavior that essentially promoted the exclusion for income level, university management linked to capitalist bourgeois interests, outdated laws remained in force and decontextualized, in its generality, the practice of university graduates was reproductive foreign models characteristic of the capitalist system. This reality has been changing radically progressive and after the enactment of the Constitution of the Bolivarian Republic of Venezuela in 1999, the creation of the Bolivarian University, the Sucre Mission, Mission Alma Mater, the decree of Education Law, among other initiatives of the Bolivarian government. In this reality, originates the National Training Program in Quality Systems and Environment (PNFSCA as a college project, designed for a social, political, economic and cultural different: XXI century socialism. This paper aims to present the experience of reconstruction curriculum of this PNFSCA, through the joint efforts of Venezuelan and Cuban specialists in the areas of quality, environment and curriculum. As main results are, first, the determination of PNFSCA links with the Simón Bolívar National Project 2007-2013, curricular reconstruction of their goals, objectives, structure, curriculum, professional profiles and development of several programs Synoptics. Finally done, as a proposal, design and presentation of a master in the same program, aimed at teachers who administer it.RESUMENLa universidad venezolana antes de la Revolución Bolivariana se caracterizó por un comportamiento institucional que esencialmente promovía la exclusión para el ingreso al nivel, una gestión universitaria ligada a intereses de la burguesía capitalista, mantuvo en vigencia leyes obsoletas y descontextualizadas; en su generalidad, la práctica de los egresados universitarios era reproductora de modelos foráneos característicos del sistema

  10. Radioisotopes and Radiation in Animal and Plant Insect Pest Control; Emploi des radioisotopes et des rayonnements dans la lutte contre les insectes nuisibles aux plantes et aux animaux; Ispol'zovanie radioizotopov i radiashchi v bor'be s nasekomymi-vreditelyami rastenij i zhivotnykh; Utilizacion de los radioisotopos y de las radiaciones en la lucha contra los insectos nocivos para las plantas y los animales

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, S. V.; Martens, B. K.; Samojlova, V. A.; Molchanova, Z. I. [Vsesoyuznyj Institut Zashchity Rastenij, Leningrad, SSSR (Russian Federation)


    degrees of stability when subjected to the action of herbicides. Pesticides containing trace quantities of isotopes with short half-lives can be used as a means of judging the merits of various spraying systems for treating seeds and agricultural crops with pesticides; this method also provides information about the optimum doses. Experiments have shown that ionizing radiations can be used to increase the virulence of insect nosophytes (Beauveria vassiana Unill.) and thus improve the efficiency of microbiological insect-pest-control methods. The sterilizing and lethal effects of ionizing radiations are also useful in combatting insect pests. Gamma-ray experiments have made it possible to establish sterilizing doses for a number of insect pests which attack crops and stored products (Calandra granaria L., Acanthoscelides obtectus Say, Pectinophora malvella Hb., Leptinotarsa decemlineota Say, Chloridea obsoleta F.). The data obtained in these investigations will be used to develop and improve the methods of insect-pest control used in agriculture. (author) [French] Le probleme de la lutte contre les parasites des cultures presente une grande importance pour l'economie nationale. Il importe, pour le resoudre, de tirer parti des realisations scientifiques les plus recentes. Pour rationaliser les methodes actuelles de lutte contre les insectes nuisibles et accroitre l'efficacite de ces methodes, on a fait appel aux radioisotopes et aux rayonnements. Grace a remploi des radioisotopes et des rayonnements, il est possible de rationaliser dans une large mesure les methodes utilisees et d'augmenter leur efficacite. A cet effet, il est indispensable d'etudier a fond les problemes d'ecologie, de toxicologie, etc. Dans le domaine de l'ecologie, la methode du radiomarquage des insectes est particulierement prometteuse. L'emploi de radioisotopes pour le marquage des insectes ravageurs des cereales (Eurygaster integriceps Put. et Hadena sordida Skh.) et de leurs parasites (Meniscus

  11. El nuevo tratamiento legal de las enfermedades profesionales en comparación con lo derogado y con la recomendación Europea sobre el tema

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    N. Gambí Pisonero


    Full Text Available Los avances producidos en los procesos industriales, la introducción de nuevos elementos y sustancias, el progreso en el ámbito científico y la necesidad de ajustarse a las recomendaciones europeas han desembocado en la aprobación del nuevo Real Decreto 1299/2006 de enfermedades profesionales. Conocer y manejar de forma adecuada la lista de enfermedades profesionales vigente es paso indispensable para proceder a declarar todas y cada una de estas enfermedades. Nuestro trabajo se centra en el análisis de la estructura y los cambios que muestra el nuevo cuadro respecto al ya derogado y comparación con las recomendaciones europeas acerca del tema La infradeclaración de EP a la que hemos estado asistiendo podría explicarse en parte por la vigencia hasta hace poco de una lista obsoleta. La reciente publicación del nuevo cuadro de EP ha generado muchas expectativas aunque no faltan opiniones críticas que ponen en duda su eficacia en la consecución del objetivo de subsanar esta infradeclaración. En general el nuevo Real Decreto se ajusta a las Recomendaciones Europeas y aporta importantes cambios estructurales y de contenido, ajustándose a un modelo mixto. Si bien carece del enfoque preventivo que incentivaba la Unión Europea y deja a un lado las enfermedades por riesgos psicosociales.The advances produced in the industrial processes, introduction of new elements and substances, progress in the scientific scope and the need to harmonize the national regulation to the European recommendations have ended at the approval of the new Real Decree 1299/2006 of professional diseases. To know and to handle in a suitable way the effective professional diseases list it is an indispensable step in order to notify all and each one of these diseases. Our study is focused in the analysis of the structure and the changes that the new list shows with respect to the precedent one and the comparison with the European recommendation concerning this subjet

  12. Three new Hepatozoon species (Apicomplexa: Hepatozoidae) infecting the Florida kingsnake, Lampropeltis getula floridana. (United States)

    Telford, Sam R


    The Florida kingsnake, Lampropeltis getula floridana, is host to 3 species of Hepatozoon at the type locality, Miramar, Broward County, Florida, and 2, possibly all 3, species at Cedar Key, Levy County, approximately 480 km to the northwest. Hepatozoon eurytopis, n. sp. was present also in Diadophis punctatus and Elaphe guttata in Jupiter Farms, Palm Beach County, and in Thamnophis sirtalis at Gainesville, Alachua County. Specific identity in D. punctatus was determined from gamont morphology and from sporogonic stages and gamont morphology in the infections obtained from E. guttata and T. sirtalis. Infection with all 3 species by ingestion of infected mosquitoes was easily obtained in E. guttata, but only H. eurytopis produced experimental infection in T. sirtalis and Storeria occipitomaculata. Hepatozoon eurytopis differed from the other 2 species, H. karyolysi n. sp. and H. rexi n. sp., by its short and broad, recurved gamonts with average dimensions 11.2-13.1 x 4.5-5.4 microm, length x maximum width (LW) 56-64 microm(2), and L/W ratios 2.13-2.80 in all host species, large round oocysts 95-303 x 91-285 microm, L/W ratios 1.03-1.05 with spherical to ovoid sporocysts 22-50 x 21-44 microm, L/W ratios 1.00-1.82 that contain 33.5-44.4 (16-76) sporozoites. The nucleus in immature gamonts is highly irregular, often fragmented in separate masses of chromatin, and commonly appears to form binucleate gamonts before maturity. Hepatozoon karyolysi has elongate, non-recurved gamonts, 15-20 x 4-7 microm, LW 64-143 microm(2), L/W ratios 2.3-4.5 that usually cause lysis or irregular margins of the nucleus in infected erythrocytes of the type host. Oocysts are spherical, 127-243 x 122-233 microm, L/W ratio 1.0-1.1 that contain spherical to usually ovoid sporocysts 17-30 x 17-24 microm, and produce 12-20 sporozoites. Gamonts of Hepatozoon rexi are non-recurved, 14-18 x 4-6 microm, LW 67-102 microm(2), and L/W ratio 2.8-4.1, and are usually surrounded by a prominent cyst wall

  13. A systematic revision of Baconia Lewis (Coleoptera, Histeridae, Exosternini

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    Michael Caterino


    Full Text Available Here we present a complete revision of the species of Baconia. Up until now there have been 27 species assigned to the genus (Mazur, 2011, in two subgenera (Binhister Cooman and Baconia s. str., with species in the Neotropical, Nearctic, Palaearctic, and Oriental regions. We recognize all these species as valid and correctly assigned to the genus, and redescribe all of them. We synonymize Binhister, previously used for a polyphyletic assemblage of species with varied relationships in the genus. We move four species into Baconia from other genera, and describe 85 species as new, bringing the total for the genus to 116 species. We divide these into 12 informal species groups, leaving 13 species unplaced to group. We present keys and diagnoses for all species, as well as habitus photos and illustrations of male genitalia for nearly all. The genus now contains the following species and species groups: Baconia loricata group [B. loricata Lewis, 1885, B. patula Lewis, 1885, B. gounellei (Marseul, 1887a, B. jubaris (Lewis, 1901, B. festiva (Lewis, 1891, B. foliosoma sp. n., B. sapphirina sp. n., B. furtiva sp. n., B. pernix sp. n., B. applanatis sp. n., B. disciformis sp. n., B. nebulosa sp. n., B. brunnea sp. n.], B. godmani group [B. godmani (Lewis, 1888, B. venusta (J. E. LeConte, 1845, B. riehli (Marseul, 1862, comb. n., B. scintillans sp. n., B. isthmia sp. n., B. rossi sp. n., B. navarretei sp. n., B. maculata sp. n., B. deliberata sp. n., B. excelsa sp. n., B. violacea (Marseul, 1853, B. varicolor (Marseul, 1887b, B. dives (Marseul, 1862, B. eximia (Lewis, 1888, B. splendida sp. n., B. jacinta sp. n., B. prasina sp. n., B. opulenta sp. n., B. illustris (Lewis, 1900, B. choaspites (Lewis, 1901, B. lewisi Mazur, 1984], B. salobrus group [B. salobrus (Marseul, 1887b, B. turgifrons sp. n., B. crassa sp. n., B. anthracina sp. n., B. emarginata sp. n., B. obsoleta sp. n.], B. ruficauda group [B. ruficauda sp. n., B. repens sp. n.], B. angusta group [B

  14. A systematic revision of Baconia Lewis (Coleoptera, Histeridae, Exosternini). (United States)

    Caterino, Michael S; Tishechkin, Alexey K


    turgifrons sp. n., Baconia crassa sp. n., Baconia anthracina sp. n., Baconia emarginata sp. n., Baconia obsoleta sp. n.], Baconia ruficauda group [Baconia ruficauda sp. n., Baconia repens sp. n.], Baconia angusta group [Baconia angusta Schmidt, 1893a, Baconia incognita sp. n., Baconia guartela sp. n., Baconia bullifrons sp. n., Baconia cavei sp. n., Baconia subtilis sp. n., Baconia dentipes sp. n., Baconia rubripennis sp. n., Baconia lunatifrons sp. n.], Baconia aeneomicans group [Baconia aeneomicans (Horn, 1873), Baconia pulchella sp. n., Baconia quercea sp. n., Baconia stephani sp. n., Baconia irinae sp. n., Baconia fornix sp. n., Baconia slipinskii Mazur, 1981, Baconia submetallica sp. n., Baconia diminua sp. n., Baconia rufescens sp. n., Baconia punctiventer sp. n., Baconia aulaea sp. n., Baconia mustax sp. n., Baconia plebeia sp. n., Baconia castanea sp. n., Baconia lescheni sp. n., Baconia oblonga sp. n., Baconia animata sp. n., Baconia teredina sp. n., Baconia chujoi (Cooman, 1941), Baconia barbarus (Cooman, 1934), Baconia reposita sp. n., Baconia kubani sp. n., Baconia wallacea sp. n., Baconia bigemina sp. n., Baconia adebratti sp. n., Baconia silvestris sp. n.], Baconia cylindrica group [Baconia cylindrica sp. n., Baconia chatzimanolisi sp. n.], Baconia gibbifer group [Baconia gibbifer sp. n., B. piluliformis sp. n., Baconia maquipucunae sp. n., Baconia tenuipes sp. n., Baconia tuberculifer sp. n., Baconia globosa sp. n.], Baconia insolita group [Baconia insolita (Schmidt, 1893a), comb. n., Baconia burmeisteri (Marseul, 1870), Baconia tricolor sp. n., Baconia pilicauda sp. n.], Baconia riouka group [Baconia riouka (Marseul, 1861), Baconia azuripennis sp. n.], Baconia famelica group [Baconia famelica sp. n., Baconia grossii sp. n., Baconia redemptor sp. n., Baconia fortis sp. n., Baconia longipes sp. n., Baconia katieae sp. n., Baconia cavifrons (Lewis, 1893), comb. n., Baconia haeterioides sp. n.], Baconia micans group [Baconia micans (Schmidt, 1889a), Baconia


    Noguchi, H


    Ten varieties of North American shellfish were examined for the occurrence of Cristispira in their styles. A cristispira was found in various numbers in Ostrea virginiana, Venus mercenaria, and Modiola modiolus, but none in Ensis americana, Mya arenaria, Mactra solidissima, Pecten irradians, Mytilus edulis, Fulgur canaliculatus, or Nassa obsoleta. Of 298 oysters, only 128 showed the crystalline styles, in which cristispiras were present in 99. Active cristispiras were found in 59 styles only and degenerated forms in the remaining 40. In 110 clams (Venus mercenaria) 70 styles were found, and only 8 of these contained cristispiras; 5 yielded active and the other 3 degenerated cristispiras. In 97 modiolas there were 73 styles, only 4 of which contained cristispiras. The physical properties of the crystalline styles of these shellfish varied considerably. The styles of the oysters were moderately soft, and when exposed to the air or mixed with sea water they underwent liquefaction, forming a clear, viscid material. The styles from clams and modiolas were opaque and were more firm, not easily crushed even in a mortar. The styles of the scallops were the most solid of all the styles examined. It happened that the softer the styles, the more frequent was the occurrence of the cristispira; in fact, no cristispira was detected in styles other than those of oysters, clams, and modiolas, of which oysters had the softest styles and the largest percentage of cristispira invasion. The following observations were made regarding the structure of the cristispira found in oysters. The body is a long, flexible cylinder, with blunt extremities, towards which the diameter gradually diminishes. In motion the body rapidly stretches and contracts, forming in the contracted state several serpentine undulations. A membranous appendage (Gross' crista) winds about the body throughout its entire length. The inner margin is in connection with the body, the outer margin is free and is distinctly

  16. La Unidad Médica Nacional

    Directory of Open Access Journals (Sweden)

    Gilberto Rueda Pérez


    Full Text Available

    La medicina en Colombia y su ejercicio ético se encuentran frente a una encrucijada que se abre en caminos de difícil escogencia.

    La alta y avasalladora tecnología científica que, con la sistematización, la bioingeniería, la electrónica, la informática y la masificación, ha llevado los procedimientos, especialmente los de diagnóstico y los quirúrgicos, a metas no soñadas hace pocos años, pero que facilitan el diagnóstico y el tratamiento de procesos hasta hace poco incurables, han incrementado los costos operativos a niveles imposibles de alcanzar por la generalidad de las unidades médicas del país, reduciéndose a unos muy pocos, privilegiados, centros hospitalarios, entre nosotros llamados Clínicas, que pueden actualizarse a esos niveles.

    Mientras esta tecnología avanzada se ha logrado implementar para pequeños grupos de población que pueden acceder a ella, la medicina ofrecida a la población general del país, o sea la de menores recursos, ha ido bajando en calidad casi en la misma proporción en que la otra ha ascendido. Solamente es necesario observar la penuria de nuestros hospitales generales con dotaciones obsoletas imposibles de reparar y menos aún de reemplazar, con edificios al borde de la ruina por falta de mantenimiento; con plantas de personal congeladas desde hace 10 o más años, constituidas por trabajadores de la salud descontentos con el desempeño de sus funciones, sino, no menos grave, por los pobres resultados de su gestión.

    Esto ha ido creando en el estamento médico una sensación de insatisfacción, de malestar, de inconformidad, que se manifestar claramente en el ejercicio profesional y que lleva con frecuencia a fallas en la atención, a errores funestos ya manejos reñidos con la ética y no pocas veces con el código penal.

    Esto último se encargan de penalizarlo los innumerables tribunales y organizaciones éticas y administrativas creadas con el objeto de descubrir