994 resultados para Chemical Communication


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Case Number 91-151 Craig Gardner, an inmate in the Iowa prison system, was the subject of a force move by correctional officers while incarcerated at the Iowa State Penitentiary (ISP). This action involved the use of a chemical agent. This investigation began as a review of the use of a chemical agent in a forced cell move on June 30, 1991.

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Peter Karlson and Martin Lüscher used the term pheromone for the first time in 1959 to describe chemicals used for intra-species communication. Pheromones are volatile or non-volatile short-lived molecules secreted and/or contained in biological fluids, such as urine, a liquid known to be a main source of pheromones. Pheromonal communication is implicated in a variety of key animal modalities such as kin interactions, hierarchical organisations and sexual interactions and are consequently directly correlated with the survival of a given species. In mice, the ability to detect pheromones is principally mediated by the vomeronasal organ (VNO), a paired structure located at the base of the nasal cavity, and enclosed in a cartilaginous capsule. Each VNO has a tubular shape with a lumen allowing the contact with the external chemical world. The sensory neuroepithelium is principally composed of vomeronasal bipolar sensory neurons (VSNs). Each VSN extends a single dendrite to the lumen ending in a large dendritic knob bearing up to 100 microvilli implicated in chemical detection. Numerous subpopulations of VSNs are present. They are differentiated by the chemoreceptor they express and thus possibly by the ligand(s) they recognize. Two main vomeronasal receptor families, V1Rs and V2Rs, are composed respectively by 240 and 120 members and are expressed in separate layers of the neuroepithelium. Olfactory receptors (ORs) and formyl peptide receptors (FPRs) are also expressed in VSNs. Whether or not these neuronal subpopulations use the same downstream signalling pathway for sensing pheromones is unknown. Despite a major role played by a calcium-permeable channel (TRPC2) present in the microvilli of mature neurons TRPC2 independent transduction channels have been suggested. Due to the high number of neuronal subpopulations and the peculiar morphology of the organ, pharmacological and physiological investigations of the signalling elements present in the VNO are complex. Here, we present an acute tissue slice preparation of the mouse VNO for performing calcium imaging investigations. This physiological approach allows observations, in the natural environment of a living tissue, of general or individual subpopulations of VSNs previously loaded with Fura-2AM, a calcium dye. This method is also convenient for studying any GFP-tagged pheromone receptor and is adaptable for the use of other fluorescent calcium probes. As an example, we use here a VG mouse line, in which the translation of the pheromone V1rb2 receptor is linked to the expression of GFP by a polycistronic strategy.

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OBJECTIVE Replicating the training program in non-verbal communication based on the theoretical framework of interpersonal communication; non-verbal coding, valuing the aging aspects in the perspective of active aging, checking its current relevance through the content assimilation index after 90 days (mediate) of its application. METHOD A descriptive and exploratory field study was conducted in three hospitals under direct administration of the state of São Paulo that caters exclusively to Unified Health System (SUS) patients. The training lasted 12 hours divided in three meetings, applied to 102 health professionals. RESULTS Revealed very satisfactory and satisfactory mediate content assimilation index in 82.9%. CONCLUSION The program replication proved to be relevant and updated the setting of hospital services, while remaining efficient for healthcare professionals.

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Similar to aboveground herbivores, root-feeding insects must locate and identify suitable resources. In the darkness of soil, they mainly rely on root chemical exudations and, therefore, have evolved specific behaviours. Because of their impact on crop yield, most of our knowledge in belowground chemical ecology is biased towards soil-dwelling insect pests. Yet the increasing literature on volatile-mediated interactions in the ground underpins the great importance of chemical signalling in this ecosystem and its potential in pest control. Here, we explore the ecology and physiology of these chemically based interactions. An evolutionary approach reveals interesting patterns in the response of insects to particular classes of volatile or water-soluble organic compounds commonly emitted by roots. Food web analyses reasonably support that volatiles are used as long-range cues whereas water-soluble molecules serve in host acceptance/rejection by the insect; however, data are still scarce. As a case study, the chemical ecology of Diabrotica virgifera virgifera is discussed and applications of belowground signalling in pest management are examined. Soil chemical ecology is an expanding field of research and will certainly be a hub of our understanding of soil communities and subsequently of the management of belowground ecosystem services.

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When all three separate quorum-sensing signals act in concert in Vibrio harveyi, they maximize bioluminescence and fully repress type III secretion. V. harveyi has five qrr loci encoding small RNA regulatory molecules, each consisting of about 100 nucleotides; several of them are involved in repressing bioluminescence. Small RNAs also play roles in population density-dependent activities, including regulation of virulence factors, for bacterial pathogens such as Pseudomonas fluorescens, V. cholerae, Salmonella enterica, Pseudomonas aeruginosa, and Erwinia spp. Although some bacteria appear to carry redundant copies of small RNA genes with which to finely tune expression

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Morphological, chemical and developmental aspects of the Dufour gland in some eusocial bees (Hymenoptera, Apidae): a review. The present revision focused on the more recent data about the Dufour gland in some eusocial bees, taking in account general aspects of its morphology, secretion chemical nature, bio-synthetic pathway and development. Many functions have been attributed to this gland in eusocial bees, but none are convincing. With the new data about this gland, not only the secretion chemical pathway of the Dufour gland may be reasonable understood, as its function in some eusocial bees, especially Apis mellifera Linné, 1758, which has been extensively studied in the last years.