Las especies amenazadas son indicadoras de los puntos calientes de la regulación trófica en sentido descendente

Se ha considerado la introducción de mesopredadores y herbívoros extranjeros como el principal desencadenante de la extinción de mamíferos australianos. Estudios recientes sugieren que los efectos devastadores de las especies invasoras quedan mitigados por los superpredadores. Por lo tanto, la supervivencia de muchas especies amenazadas puede depender de la presencia y funcionalidad ecológica de los grandes predadores. El superpredador australiano, el dingo (Canis lupus dingo) ha sido muy perseguido por todo el continente, y es extremadamente raro encontrar poblaciones de dingos que no estén sujetas a un control letal. En este estudio pronosticamos que la presencia de especies amenazadas señala los lugares donde las poblaciones de dingos están relativamente intactas, y que su ausencia puede indicar que los dingos son raros o que sus poblaciones están socialmente fracturadas. La comparación entre un lugar que alberga a un marsupial amenazado, el kowari o rata marsupial de cola de pincel (Dasyuroides byrnei), y un lugar vecino, de donde falta el kowari, es concordante con el patrón que sugerimos. Palabras clave: Envenenamiento con 1080, Canis lupus dingo, Dasyuroides byrnei, Especie invasora, Control por predador, Superpredador.The introduction of alien mesopredators and herbivores has been implicated as the main driver of mammalian extinction in Australia. Recent studies suggest that the devastating effects of invasive species are mitigated by top–order predators. The survival of many threatened species may therefore depend on the presence and ecological functioning of large predators. Australia’s top predator, the dingo (Canis lupus dingo), has been intensively persecuted across the continent and it is extremely rare to find dingo populations that are not being subjected to lethal control. We predicted that the presence of threatened species point out places where dingo populations are relatively intact, and that their absence may indicate that dingoes are either rare or socially fractured. A comparison of a site which harbors a threatened marsupial, the kowari (Dasyuroides byrnei), and a neighboring site where the kowari is absent, offers support for this suggested pattern. Key words: 1080 poison–baiting, Canis lupus dingo, Dasyuroides byrnei, Invasive species, Predator control, Top predator.Se ha considerado la introducción de mesopredadores y herbívoros extranjeros como el principal desencadenante de la extinción de mamíferos australianos. Estudios recientes sugieren que los efectos devastadores de las especies invasoras quedan mitigados por los superpredadores. Por lo tanto, la supervivencia de muchas especies amenazadas puede depender de la presencia y funcionalidad ecológica de los grandes predadores. El superpredador australiano, el dingo (Canis lupus dingo) ha sido muy perseguido por todo el continente, y es extremadamente raro encontrar poblaciones de dingos que no estén sujetas a un control letal. En este estudio pronosticamos que la presencia de especies amenazadas señala los lugares donde las poblaciones de dingos están relativamente intactas, y que su ausencia puede indicar que los dingos son raros o que sus poblaciones están socialmente fracturadas. La comparación entre un lugar que alberga a un marsupial amenazado, el kowari o rata marsupial de cola de pincel (Dasyuroides byrnei), y un lugar vecino, de donde falta el kowari, es concordante con el patrón que sugerimos. Palabras clave: Envenenamiento con 1080, Canis lupus dingo, Dasyuroides byrnei, Especie invasora, Control por predador, Superpredador

Threatened species indicate hot-spots of top-down regulation

The introduction of alien mesopredators and herbivores has been implicated as the main driver of mammalian extinction in Australia. Recent studies suggest that the devastating effects of invasive species are mitigated by top-order predators. The survival of many threatened species may therefore depend on the presence and ecological functioning of large predators. Australia’s top predator, the dingo (Canis lupus dingo), has been intensively persecuted across the continent and it is extremely rare to find dingo populations that are not being subjected to lethal control. We predicted that the presence of threatened species point out places where dingo populations are relatively intact, and that their absence may indicate that dingoes are either rare or socially fractured. A comparison of a site which harbors a threatened marsupial, the kowari (Dasyuroides byrnei), and a neighboring site where the kowari is absent, offers support for this suggested pattern

Entanglement of subspaces in terms of entanglement of superpositions

We investigate upper and lower bounds on the entropy of entanglement of a superposition of bipartite states as a function of the individual states in the superposition. In particular, we extend the results in [G. Gour, arxiv.org:0704.1521 (2007)] to superpositions of several states rather than just two. We then investigate the entanglement in a subspace as a function of its basis states: we find upper bounds for the largest entanglement in a subspace and demonstrate that no such lower bound for the smallest entanglement exists. Finally, we consider entanglement of superpositions using measures of entanglement other than the entropy of entanglement.Comment: 7 pages, no figure

Description of a papillate tactile organ in the Typhlopidae

In a unique specimen of Rhinotyphlops, the rostrum supports approximately 250 elongate, flexible papillae. Each papilla consists of a tubular shaft and an expanded hair-like bulb weakly embedded in the epidermis. Immediately deep to the base of each papilla is a small cluster of neuronal cells and a vascular supply. Although this Rhinotyphlops is presumed to be fossorial, the morphology of these soft papilla suggest they function as mechanoreceptors

Novel screening test for celiac disease using peptide functionalised gold nanoparticles

© The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved. AIM To develop a screening test for celiac disease based on the coating of gold nanoparticles with a peptide sequence derived from gliadin, the protein that triggers celiac disease. METHODS 20 nm gold nanoparticles were first coated with NeutrAvidin. A long chain Polyethylene glycol (PEG) linker containing Maleimide at the Ω-end and Biotin group at the α-end was used to ensure peptide coating to the gold nanoparticles. The maleimide group with the thiol (-SH) side chain reacted with the cysteine amino acid in the peptide sequence and the biotinylated and PEGylated peptide was added to the NeutrAvidin coated gold nanoparticles. The peptide coated gold nanoparticles were then converted into a serological assay. We used the peptide functionalised gold nanoparticle-based assay on thirty patient serum samples in a blinded assessment and compared our results with the previously run serological and pathological tests on these patients. RESULTS A stable colloidal suspension of peptide coated gold nanoparticles was obtained without any aggregation. An absorbance peak shift as well as color change was caused by the aggregation of gold nanoparticles following the addition of anti-gliadin antibody to peptide coated nanoparticles at levels associated with celiac disease. The developed assay has been shown to detect anti-gliadin antibody not only in quantitatively spiked samples but also in a small-scale study on real non-hemolytic celiac disease patient’s samples. CONCLUSION The study demonstrates the potential of gold nanoparticle-peptide based approach to be adapted for developing a screening assay for celiac disease diagnosis. The assay could be a part of an exclusion based diagnostic strategy and prove particularly useful for testing high celiac disease risk populations

The sectional curvature remains positive when taking quotients by certain nonfree actions

We study some cases when the sectional curvature remains positive under the taking of quotients by certain nonfree isometric actions of Lie groups. We consider the actions of the groups $S^1$ and $S^3$ such that the quotient space can be endowed with a smooth structure using the fibrations $S^3/S^1{\simeq}S^2$ and $S^7/S^3\simeq S^4$. We prove that the quotient space carries a metric of positive sectional curvature, provided that the original metric has positive sectional curvature on all 2-planes orthogonal to the orbits of the action.Comment: 26 pages, 1 figure. Changed the spelling of the author's nam

Diffusion Of Responsibility And Level Of Risk Taking In Groups 1

This study reports evidence supporting the following propositions: (1) Group discussion and consensus concerning decisions that involve actual risk ana payoffs lead to greater risk taking than occurs in the absence of such discussion and consensus. (2) The mechanism that underlies this group‐induced shift toward greater risk taking consists of a diffusion or spreading of responsibility. Using risks and payoffs based on monetary gain and loss for problem‐solving performance, the above propositions received strong confirmation for male college subjects. The results of various experimental manipulations provided positive support for viewing diffusion of responsibility as the causal factor at work.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108279/1/ets200956.pd

Group Influence On Individual Risk Taking 1

Does group interaction lead to greater conservatism or to greater risk taking in decisions than would obtain were the decisions arrived at individually.–or is there an averaging effect? This question was investigated with a procedure in which the protagonist in each of 12 everyday life situations must choose between two courses of action, one of which involves considerably more risk than the other but also is much more rewarding if successful. The S must decide on the lowest level of probability for the success of the risky alternative that he would deem sufficient to warrant its choice. A total of 218 liberal arts university students participated in the study. In the experimental condition, the S s first arrived at individual decisions concerning each of the 12 situations; then, they were brought together in discussion groups of six with the request that they reach a group consensus on each decision; and afterward, they were asked to make all their decisions privately once again. Some S s also made private decisions yet another time two to six weeks later. The group members' judgments of one another's relative degrees of influence and of popularity within the group also were obtained. There were 14 all‐male and 14 all‐female groups. In the control condition, S s made their decisions individually each of two times with one week intervening, under instructions the second time that encouraged them to change rather than simply to recall their earlier decisions. It was found that (1) group decisions exhibit greater risk taking than appears in pre‐discussion individual decisions; (2) post‐discussion private decisions exhibit the same increase in risk taking as occurs in the group decisions; (3) the increase in risk taking resulting from the discussion process is still maintained after a subsequent period of two to six weeks has elapsed; (4) no shift in risk taking level occurs over time in the absence of the discussion process; and (5) degree of risk taking in pre‐discussion individual decisions and degree of judged influence within the group are positively related. Two interpretations of these findings were suggested, either or both of which may apply: (1) the knowledge that one's decisions are being made jointly with others leads to a diffusion of personal responsiblity, the outcome of which is an increased willingness to take risks; (2) high risk takers are more likely to take the initiative in social situations, with the result that they become more influential in the group.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108371/1/ets200112.pd