2,365 research outputs found
Beta-Adrenergic Receptor Blockade By Propranolol Enhances Retention In A Multitrial Passive-Avoidance Procedure
The effect of beta -adrenergic receptor blockade on retention in a mildly aversive passive-avoidance procedure was investigated. Rats were given passive-avoidance training-1 trial per day for 4 days-and were administered saline, the centrally and peripherally acting beta -adrenergic blocker propranolol (4 or 10 mg/kg ip), or the peripherally acting P-adrenergic blocker sotalol (4 or 10 mg/kg ip) immediately or 2 hr after the Ist trial. Enhanced retention occurred only with the higher dose (10 mg/kg) of propranolol and only when it was administered immediately after training. The enhanced retention produced by propranolol is discussed in terms of opposing, regionally specific actions of beta -adrenergic receptor-mediated neural circuits on modulation of memory
A laminar flow model of aerosol survival of epidemic and non-epidemic strains of Pseudomonas aeruginosa isolated from people with cystic fibrosis
Cystic fibrosis (CF) is an inherited multi-system disorder characterised by chronic airway infection with pathogens such as Pseudomonas aeruginosa.
Acquisition of P. aeruginosa by patients with CF is usually from the environment, but recent studies have demonstrated patient to patient transmission of certain epidemic strains, possibly via an airborne route. This study was designed to examine the survival of P. aeruginosa within artificially generated aerosols.
Survival was effected by the solution used for aerosol generation. Within the aerosols it was adversely affected by an increase in air temperature. Both epidemic and non-epidemic strains of P. aeruginosa were able to survive within the aerosols, but strains expressing a mucoid phenotype had a survival advantage.
This would suggest that segregating individuals free of P. aeruginosa from those with chronic P. aeruginosa infection who are more likely to be infected with mucoid strains may help reduce the risk of cross-infection. Environmental factors also appear to influence bacterial survival. Warming and drying the air within clinical areas and avoidance of humidification devices may also be beneficial in reducing the risk of cross-infection
Low Cost Swarm Based Diligent Cargo Transit System
The goal of this paper is to present the design and development of a low cost
cargo transit system which can be adapted in developing countries like India
where there is abundant and cheap human labour which makes the process of
automation in any industry a challenge to innovators. The need of the hour is
an automation system that can diligently transfer cargo from one place to
another and minimize human intervention in the cargo transit industry.
Therefore, a solution is being proposed which could effectively bring down
human labour and the resources needed to implement them. The reduction in human
labour and resources is achieved by the use of low cost components and very
limited modification of the surroundings and the existing vehicles themselves.
The operation of the cargo transit system has been verified and the relevant
results are presented. An economical and robust cargo transit system is
designed and implemented.Comment: 6 pages, 9 figures, 1 block diagra
Stress-Dependent Impairment Of Passive-Avoidance Memory By Propranolol Or Naloxone
Previous work has shown that the effect of opioid-receptor blockade on memory modulation is critically dependent upon the intensity of stress. The current study determined the effect of adrenergic-receptor blockade on memory modulation under varied levels of stress and then compared the effect of adrenergic-receptor blockade under intense stress to that of a) opioid-receptor blockade and b) concurrent opioid- and adrenergic-receptor blockade. In the first experiment, the β-adrenergic-receptor blocker propranolol impaired retention in the passive-avoidance procedure when administered immediately after exposure to intense stress (passive-avoidance training followed by swim stress) but not mild stress (passive-avoidance training alone). In the second experiment, while separate administration of either propranolol or the opioid-receptor blocker naloxone immediately after exposure to intense stress impaired retention, the combined administration of propranolol and naloxone failed to do so. These findings demonstrate that the effect of β-adrenergic-receptor blockade or opioid-receptor blockade on memory modulation in the passive-avoidance procedure is dependent upon the intensity of stress, and suggest that concurrent inactivation of endogenous adrenergic- and opioid-based memory modulation systems under stressful conditions is protective of memory
Putting our money where their mouth is: alignment of charitable aims with charity investments - tensions in policy and practice
Given the values-driven nature of the mission of most charities, it might be expected that investment behaviour would be similarly values-driven. This paper documents the ethical investment policies and practices of the largest UK charities and explores how these are aligned with the charitable aims, drawing upon accountability, behavioural and managerial perspectives as theoretical lenses. The study employs two distinct research methods: responses to a postal questionnaire and follow-up semi-structured interviews with selected charities. The evidence indicates that a significant minority of large charities do not have a written ethical investment policy. Charities with larger investments, fundraising charities and religious charities were more likely to have a written ethical policy. We suggest that there is a pressing need for improved alignment between charities' aims and their investment practices and better monitoring of investment policies
Collision-avoidance and landing responses are mediated by separate pathways in the fruit fly, Drosophila melanogaster
Flies rely heavily on visual feedback for several aspects of flight control. As a fly approaches an object, the image projected across its retina expands, providing the fly with visual feedback that can be used either to trigger a collision-avoidance maneuver or a landing response. To determine how a fly makes the decision to land on or avoid a looming object, we measured the behaviors generated in response to an expanding image during tethered flight in a visual closed-loop flight arena. During these experiments, each fly varied its wing-stroke kinematics to actively control the azimuth position of a 15°×15° square within its visual field. Periodically, the square symmetrically expanded in both the horizontal and vertical directions. We measured changes in the fly's wing-stroke amplitude and frequency in response to the expanding square while optically tracking the position of its legs to monitor stereotyped landing responses. Although this stimulus could elicit both the landing responses and collision-avoidance reactions, separate pathways appear to mediate the two behaviors. For example, if the square is in the lateral portion of the fly's field of view at the onset of expansion, the fly increases stroke amplitude in one wing while decreasing amplitude in the other, indicative of a collision-avoidance maneuver. In contrast, frontal expansion elicits an increase in wing-beat frequency and leg extension, indicative of a landing response. To further characterize the sensitivity of these responses to expansion rate, we tested a range of expansion velocities from 100 to 10000° s^(-1). Differences in the latency of both the collision-avoidance reactions and the landing responses with expansion rate supported the hypothesis that the two behaviors are mediated by separate pathways. To examine the effects of visual feedback on the magnitude and time course of the two behaviors, we presented the stimulus under open-loop conditions, such that the fly's response did not alter the position of the expanding square. From our results we suggest a model that takes into account the spatial sensitivities and temporal latencies of the collision-avoidance and landing responses, and is sufficient to schematically represent how the fly uses integration of motion information in deciding whether to turn or land when confronted with an expanding object
Vehicle to Vehicle (V2V) Communication for Collision Avoidance for Multi-Copters Flying in UTM -TCL4
NASAs UAS Traffic management (UTM) research initiative is aimed at identifying requirements for safe autonomous operations of UAS operating in dense urban environments. For complete autonomous operations vehicle to vehicle (V2V) communications has been identified as an essential tool. In this paper we simulate a complete urban operations in an high fidelity simulation environment. We design a V2V communication protocol and all the vehicles participating communicate over this system. We show how V2V communication can be used for finding feasible, collision-free paths for multi agent systems. Different collision avoidance schemes are explored and an end to end simulation study shows the use of V2V communication for UTM TCL4 deployment
Spatial learning and memory in the tortoise (Geochelone carbonaria)
A single tortoise (Geochelone carbonaria) was trained in an eight-arm radial maze, with the apparatus and general procedures modeled on those used to demonstrate spatial learning in rats. The tortoise learned to perform reliably above chance, preferentially choosing baited arms, rather than returning to arms previously visited on a trial. Test sessions that examined control by olfactory cues revealed that they did not affect performance. No systematic, stereotyped response patterns were evident. In spite of differences in brain structure, the tortoise showed spatial learning abilities comparable to those observed in mammals
Adaptive immunity in cancer immunology and therapeutics.
Copyright:
© the authors; licensee
ecancermedicalscience. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction
in any medium, provided the original work is properly cited.The vast genetic alterations characteristic of tumours produce a number of tumour antigens that enable the immune system to differentiate tumour cells from normal cells. Counter to this, tumour cells have developed mechanisms by which to evade host immunity in their constant quest for growth and survival. Tumour-associated antigens (TAAs) are one of the fundamental triggers of the immune response. They are important because they activate, via major histocompatibility complex (MHC), the T cell response, an important line of defense against tumourigenesis. However, the persistence of tumours despite host immunity implies that tumour cells develop immune avoidance. An example of this is the up-regulation of inhibitory immune checkpoint proteins, by tumours, which induces a form of self-tolerance. The majority of monoclonal antibodies in clinical practice have been developed to target tumour-specific antigens. More recently there has been research in the down-regulation of immune checkpoint proteins as a way of increasing anti-tumour immunity
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