544 research outputs found
Arachidonic acid-induced release of calcium in permeabilized human neutrophils
AbstractThe addition of arachidonic acid to a suspension of digitonin-permeabilized human neutrophils was found to induce, in a dose-dependent manner (ED50 about 15 μM), the release of calcium from internal stores. Arachidic acid was without effect, while linoleic acid and linolenic acid were (on a concentration basis) at least 5-times less active than arachidonic acid. The activity of arachidonic acid appears to be due to the fatty acid itself and not to one of its metabolites. The pool of calcium mobilized by arachidonic acid includes that sensitive to inositol 1,4,5-trisphosphate. These results demonstrate a significant intracellular role for arachidonic acid at the level of the internal mobilization of calcium in human neutrophils
Centrifugal terms in the WKB approximation and semiclassical quantization of hydrogen
A systematic semiclassical expansion of the hydrogen problem about the
classical Kepler problem is shown to yield remarkably accurate results. Ad hoc
changes of the centrifugal term, such as the standard Langer modification where
the factor l(l+1) is replaced by (l+1/2)^2, are avoided. The semiclassical
energy levels are shown to be exact to first order in with all higher
order contributions vanishing. The wave functions and dipole matrix elements
are also discussed.Comment: 5 pages, to appear in Phys. Rev.
A novel bocavirus in canine liver
Background: Bocaviruses are classified as a genus within the Parvoviridae family of single-stranded DNA viruses and are pathogenic in some mammalian species. Two species have been previously reported in dogs, minute virus of canines (MVC), associated with neonatal diseases and fertility disorders; and Canine bocavirus (CBoV), associated with respiratory disease.
Findings: In this study using deep sequencing of enriched viral particles from the liver of a dog with severe hemorrhagic gastroenteritis, necrotizing vasculitis, granulomatous lymphadenitis and anuric renal failure, we identified and characterized a novel bocavirus we named Canine bocavirus 3 (CnBoV3). The three major ORFs of CnBoV3 (NS1, NP1 and VP1) shared less than 60% aa identity with those of other bocaviruses qualifying it as a novel species based on ICTV criteria. Inverse PCR showed the presence of concatemerized or circular forms of the genome in liver.
Conclusions: We genetically characterized a bocavirus in a dog liver that is highly distinct from prior canine bocaviruses found in respiratory and fecal samples. Its role in this animal’s complex disease remains to be determined.
Keywords: Canine bocavirus 3; Episome; Coinfectio
ZnAl hydrotalcites modified with nanocomposites nZVI–PAA for environmental remediation
Diffraction patterns of polyacrylic acid (PAA) encapsulated-(Fe)-modified ZnAl hydrotalcite (ZnAlH) showed the integration of Fe in the H lattice, resulting in a hybrid nanocomposite (Fe-PAA-ZnAlH), which was mainly verified with the characteristic shift in the 59–63° (2θ) region of the ZnAlH (110) reflection plane. The rise in the unit cell parameters (c and a) as the Fe % incremented, denoted incorporation of Fe in the ZnAlH red. Nonetheless, changes in the immobilizer molecular weight (PAA MW) from 1250 kDa to 5.1 kDa did not cause a difference in the distance between layers (c parameter) but in the cation-cation separation (a parameter), which meant that the nanoparticle was not located between layers, but in the lattice. The resulting band gap energies of the calcined hybrid nanocomposites were among 1.07–1.21 eV, which is an additional support of Fe+3 integration, suggesting insertion of Fe+3 3d orbitals between the valence and the conduction band of ZnO. Furthermore, nZVI were prepared through a pre-agglomeration reduction method, where COOH-groups were bound to metal cations. Initially, aqueous Fe+2 was bound to PAA [Fe+2-PAA], then reduced to obtain enclosed hybrid (nZVI-PAA). Less stability and more aggregation were observed with the lower molecular weight PAA. Additionally, PAA dissociation caused by pH changes affected the clustering of the nZVI particles. At higher MW, the hydrodynamic diameter and size distribution become smaller and tighter, respectively, allowing a more monodispersed population with sphere shape and organized in core–shell beads chains.Fil: Nieto Zambrano, Sorelis. Universidad de Guanajuato; MéxicoFil: Ramos Ramirez, Esthela. Universidad de Guanajuato; MéxicoFil: Tzompantzi Morales, Francisco. Universidad Autónoma Metropolitana; MéxicoFil: Boffito, Daria Camilla. No especifíca;Fil: Naccache, Rafik. Concordia University; CanadáFil: Gutiérrez Ortega, Norma L.. Universidad de Guanajuato; MéxicoFil: Litter, Marta Irene. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Cipagauta Diaz, Sandra. Universidad Autónoma Metropolitana; MéxicoFil: Barbosa López, Aida Liliana. Universidad de Cartagena.; Colombi
Letter Binding and Invariant Recognition of Masked Words. Behavioral and Neuroimaging Evidence
The Flexibility of Nonconsciously Deployed Cognitive Processes: Evidence from Masked Congruence Priming
Background: It is well accepted in the subliminal priming literature that task-level properties modulate nonconscious processes. For example, in tasks with a limited number of targets, subliminal priming effects are limited to primes that are physically similar to the targets. In contrast, when a large number of targets are used, subliminal priming effects are observed for primes that share a semantic (but not necessarily physical) relationship with the target. Findings such as these have led researchers to conclude that task-level properties can direct nonconscious processes to be deployed exclusively over central (semantic) or peripheral (physically specified) representations. Principal Findings: We find distinct patterns of masked priming for "novel" and "repeated" primes within a single task context. Novel primes never appear as targets and thus are not seen consciously in the experiment. Repeated primes do appear as targets, thereby lending themselves to the establishment of peripheral stimulus-response mappings. If the source of the masked priming effect were exclusively central or peripheral, then both novel and repeated primes should yield similar patterns of priming. In contrast, we find that both novel and repeated primes produce robust, yet distinct, patterns of priming. Conclusions: Our findings indicate that nonconsciously elicited cognitive processes can be flexibly deployed over both central and peripheral representations within a single task context. While we agree that task-level properties can influence nonconscious processes, our findings sharply constrain the extent of this influence. Specifically, our findings are inconsistent with extant accounts which hold that the influence of task-level properties is strong enough to restrict the deployment of nonconsciously elicited cognitive processes to a single type of representation (i.e. central or peripheral).13 page(s
Helminth resistance is mediated by differential activation of recruited monocyte-derived alveolar macrophages and arginine depletion
Macrophages are known to mediate anti-helminth responses, but it remains uncertain which subsets are involved or how macrophages actually kill helminths. Here, we show rapid monocyte recruitment to the lung after infection with the nematode parasite Nippostrongylus brasiliensis. In this inflamed tissue microenvironment, these monocytes differentiate into an alveolar macrophage (AM)-like phenotype, expressing both SiglecF and CD11c, surround invading parasitic larvae, and preferentially kill parasites in vitro. Monocyte-derived AMs (Mo-AMs) express type 2-associated markers and show a distinct remodeling of the chromatin landscape relative to tissue-derived AMs (TD-AMs). In particular, they express high amounts of arginase-1 (Arg1), which we demonstrate mediates helminth killing through L-arginine depletion. These studies indicate that recruited monocytes are selectively programmed in the pulmonary environment to express AM markers and an anti-helminth phenotype
The Flexible Nature of Unconscious Cognition
The cognitive signature of unconscious processes is hotly debated recently. Generally, consciousness is thought to mediate flexible, adaptive and goal-directed behavior, but in the last decade unconscious processing has rapidly gained ground on traditional conscious territory. In this study we demonstrate that the scope and impact of unconscious information on behavior and brain activity can be modulated dynamically on a trial-by-trial basis. Participants performed a Go/No-Go experiment in which an unconscious (masked) stimulus preceding a conscious target could be associated with either a Go or No-Go response. Importantly, the mapping of stimuli onto these actions varied on a trial-by-trial basis, preventing the formation of stable associations and hence the possibility that unconscious stimuli automatically activate these control actions. By eliminating stimulus-response associations established through practice we demonstrate that unconscious information can be processed in a flexible and adaptive manner. In this experiment we show that the same unconscious stimulus can have a substantially different effect on behavior and (prefrontal) brain activity depending on the rapidly changing task context in which it is presented. This work suggests that unconscious information processing shares many sophisticated characteristics (including flexibility and context-specificity) with its conscious counterpart
Psychodynamic Experience Enhances Recognition of Hidden Childhood Trauma
BACKGROUND: Experimental psychology has only recently provided supporting evidence for Freud's and Janet's description of unconscious phenomena. Here, we aimed to assess whether specific abilities, such as personal psychodynamic experience, enhance the ability to recognize unconscious phenomena in peers - in other words, to better detect implicit knowledge related to individual self-experience. METHODOLOGY AND PRINCIPAL FINDINGS: First, we collected 14 videos from seven healthy adults who had experienced a sibling's cancer during childhood and seven matched controls. Subjects and controls were asked to give a 5-minute spontaneous free-associating speech following specific instructions created in order to activate a buffer zone between fantasy and reality. Then, 18 raters (three psychoanalysts, six medical students, three oncologists, three cognitive behavioral therapists and three individuals with the same experience of trauma) were randomly shown the videos and asked to blindly classify them according to whether the speaker had a sibling with cancer using a Likert scale. Using a permutation test, we found a significant association between group and recognition score (ANOVA: p = .0006). Psychoanalysts were able to recognize, above chance levels, healthy adults who had experienced sibling cancer during childhood without explicit knowledge of this history (Power = 88%; p = .002). In contrast, medical students, oncologists, cognitive behavioral therapists and individuals who had the same history of a sibling's cancer were unable to do so. CONCLUSION: This experiment supports the view that implicit recognition of a subject's history depends on the rater's specific abilities. In the case of subjects who did have a sibling with cancer during childhood, psychoanalysts appear better able to recognize this particular history
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