624 research outputs found
Sympathetic involvement in peripheral nerve injury
The aim of this study was to investigate the response of noradrenergic sympathetic efferent fibres to Injury In a peripheral nerve, and to attempt to elucidate the cytochemical basis for the abnormal Interaction between sympathetic efferent and sensory afferent fibres which develops in experimental neuromas. The painful nerve Injury model used throughout was the experimental neuroma. The numbers, distribution and morphological relationships of sympathetic efferent fibres in normal and injured rat sciatic nerve were studied. Noradrenaline (NA) was localized in fluorescence studies by a glyoxylic acid technique. Ultrastructural localization Involved treatment of animals with a monoamine oxidase Inhibitor, nialamide, followed by a 'false' transmitter, 5 - hydroxy dopamine (5-OH DA); or alternatively, cytochemical reaction according to a modified chromaffin technique, followed by x-ray microanalysis. Two pharmacological manipulations were employed. The first Involved treatment with guanethidine, a sympathetic blocking agent, and secondly, neonatally administered capsaicin, which selectively destroys afferent C fibres. The development of alpha adrenoreceptors and opiate receptors in the spinal cord, normal and transected sciatic nerves was studied, using autoradiography with tritiated para amino clonidine, an alpha-2 adrenoreceptor ligand and tritiated diprenorphine, an opiate receptor ligand. The fluorescence studies showed an accumulation of fluorescent material, NA, at the distal end of the proximal stump of the sectioned nerves, which was maximal 3 days after section. The number of sympathetic axons fell to below normal 14 days after section and returned towards normal by 8 weeks. NA could also be seen ultrastructurally, following pretreatment with nialamide and 5-OH DA, localized to electron-dense cored vesicles within sympathetic axons. Optimal localization of NA followed subsequent fixation in chromate containing fixative and electron probe x-ray microanalysis. Guanethidine treatment caused NA depletion, which was more marked in neuromas than normal nerves, especially at the distal tip of the proximal stumps, and varied between animals. Capsaicin treatment resulted in a loss of unmyelinated afferent axons, the effect being more obvious in the normal nerves. Autoradiographic studies showed a depletion of opiate receptors on the lesioned side of the spinal cord, but a slight Increase in the number of alpha adrenergic receptors on this side. The neuromas appeared to have increased numbers of both types of receptors when compared to the normal sciatic nerves, which were not labelled
Using Search Queries to Understand Health Information Needs in Africa
The lack of comprehensive, high-quality health data in developing nations
creates a roadblock for combating the impacts of disease. One key challenge is
understanding the health information needs of people in these nations. Without
understanding people's everyday needs, concerns, and misconceptions, health
organizations and policymakers lack the ability to effectively target education
and programming efforts. In this paper, we propose a bottom-up approach that
uses search data from individuals to uncover and gain insight into health
information needs in Africa. We analyze Bing searches related to HIV/AIDS,
malaria, and tuberculosis from all 54 African nations. For each disease, we
automatically derive a set of common search themes or topics, revealing a
wide-spread interest in various types of information, including disease
symptoms, drugs, concerns about breastfeeding, as well as stigma, beliefs in
natural cures, and other topics that may be hard to uncover through traditional
surveys. We expose the different patterns that emerge in health information
needs by demographic groups (age and sex) and country. We also uncover
discrepancies in the quality of content returned by search engines to users by
topic. Combined, our results suggest that search data can help illuminate
health information needs in Africa and inform discussions on health policy and
targeted education efforts both on- and offline.Comment: Extended version of an ICWSM 2019 pape
Analysis of Activity Dependent Development of Topographic Maps in Neural Field Theory with Short Time Scale Dependent Plasticity
Topographic maps are a brain structure connecting pre-synpatic and
post-synaptic brain regions. Topographic development is dependent on
Hebbian-based plasticity mechanisms working in conjunction with spontaneous
patterns of neural activity generated in the pre-synaptic regions. Studies
performed in mouse have shown that these spontaneous patterns can exhibit
complex spatial-temporal structures which existing models cannot incorporate.
Neural field theories are appropriate modelling paradigms for topographic
systems due to the dense nature of the connections between regions and can be
augmented with a plasticity rule general enough to capture complex time-varying
structures.
We propose a theoretical framework for studying the development of topography
in the context of complex spatial-temporal activity fed-forward from the
pre-synaptic to post-synaptic regions. Analysis of the model leads to an
analytic solution corroborating the conclusion that activity can drive the
refinement of topographic projections. The analysis also suggests that
biological noise is used in the development of topography to stabilise the
dynamics. MCMC simulations are used to analyse and understand the differences
in topographic refinement between wild-type and the knock-out mutant
in mice. The time scale of the synaptic plasticity window is estimated as
seconds in this context with a model fit of .</jats:p
Heart Strings and Purse Strings: Carryover Effects of Emotions on Economic Decisions
We examined the impact of specific emotions on the endowment effect, the tendency for selling prices to exceed buying or “choice” prices for the same object. As predicted by appraisal-tendency theory, disgust induced by a prior, irrelevant situation carried over to normatively unrelated economic decisions, reducing selling and choice prices and eliminating the endowment effect. Sadness also carried over, reducing selling prices but increasing choice prices—producing a “reverse endowment effect” in which choice prices exceeded selling prices. The results demonstrate that incidental emotions can influence decisions even when real money is at stake, and that emotions of the same valence can have opposing effects on such decisions
Recommended from our members
Analysis of Activity Dependent Development of Topographic Maps in Neural Field Theory with Short Time Scale Dependent Plasticity
Topographic maps are a brain structure connecting pre-synpatic and
post-synaptic brain regions. Topographic development is dependent on
Hebbian-based plasticity mechanisms working in conjunction with spontaneous
patterns of neural activity generated in the pre-synaptic regions. Studies
performed in mouse have shown that these spontaneous patterns can exhibit
complex spatial-temporal structures which existing models cannot incorporate.
Neural field theories are appropriate modelling paradigms for topographic
systems due to the dense nature of the connections between regions and can be
augmented with a plasticity rule general enough to capture complex time-varying
structures.
We propose a theoretical framework for studying the development of topography
in the context of complex spatial-temporal activity fed-forward from the
pre-synaptic to post-synaptic regions. Analysis of the model leads to an
analytic solution corroborating the conclusion that activity can drive the
refinement of topographic projections. The analysis also suggests that
biological noise is used in the development of topography to stabilise the
dynamics. MCMC simulations are used to analyse and understand the differences
in topographic refinement between wild-type and the knock-out mutant
in mice. The time scale of the synaptic plasticity window is estimated as
seconds in this context with a model fit of .</jats:p
Burn Rate Sensitization of Solid Propellants Using A Nano-Titania Additive
Adding nanoparticles as a catalyst to solid propellant fuel to increase and enhance burn rates of the fuel by up to 10 times or more and or modifying the pressure index. A preferred embodiment uses titanium dioxide nanoparticles mixed with a solid propellant fuel, where the nanoparticles are approximately 2% or less of total propellant mixture. The high surface to volume ratio of the nanoparticles improve the performance of the solid propellant fuel
Burn Rate Sensitization of Solid Propellants Using A Nano-Titania Additive
Adding nanoparticles as a catalyst to solid propellant fuel to increase and enhance burn rates of the fuel by up to 10 times or more and or modifying the pressure index. A preferred embodiment uses titanium dioxide nanoparticles mixed with a solid propellant fuel, where the nanoparticles are approximately 2% or less of total propellant mixture. The high surface to volume ratio of the nanoparticles improve the performance of the solid propellant fuel
Mentoring Each Other: Creating a community of practice for aspiring and current library managers
Integrating formal management training into library school curriculum has been a topic of discussion for years, with varying progress. And in our experience, librarians are rarely given formal training on the job before becoming managers. We need to find ways to support new managers, helping them to acquire skills to handle the interpersonal, economic, and political challenges. Human Resources departments can provide valuable training in policy and procedures of the organization, but libraries have unique management challenges that may not exist elsewhere on campus. Librarians may be asked to manage faculty, staff, and student workers. They may need to arrange for coverage for service points, as well as work as an academic department. They work on projects with people from all parts of campus. Sometimes only other librarians understand the different dynamics of our situation. But when you’re a manager, it can be awkward to discuss specific management concerns with colleagues in your organization. Meeting with librarians from other institutions provides a comfortable level of anonymity
Developing global climate anomalies suggest potential disease risks for 2006 – 2007
BACKGROUND: El Niño/Southern Oscillation (ENSO) related climate anomalies have been shown to have an impact on infectious disease outbreaks. The Climate Prediction Center of the National Oceanic and Atmospheric Administration (NOAA/CPC) has recently issued an unscheduled El Niño advisory, indicating that warmer than normal sea surface temperatures across the equatorial eastern Pacific may have pronounced impacts on global tropical precipitation patterns extending into the northern hemisphere particularly over North America. Building evidence of the links between ENSO driven climate anomalies and infectious diseases, particularly those transmitted by insects, can allow us to provide improved long range forecasts of an epidemic or epizootic. We describe developing climate anomalies that suggest potential disease risks using satellite generated data. RESULTS: Sea surface temperatures (SSTs) in the equatorial east Pacific ocean have anomalously increased significantly during July – October 2006 indicating the typical development of El Niño conditions. The persistence of these conditions will lead to extremes in global-scale climate anomalies as has been observed during similar conditions in the past. Positive Outgoing Longwave Radiation (OLR) anomalies, indicative of severe drought conditions, have been observed across all of Indonesia, Malaysia and most of the Philippines, which are usually the first areas to experience ENSO-related impacts. This dryness can be expected to continue, on average, for the remainder of 2006 continuing into the early part of 2007. During the period November 2006 – January 2007 climate forecasts indicate that there is a high probability for above normal rainfall in the central and eastern equatorial Pacific Islands, the Korean Peninsula, the U.S. Gulf Coast and Florida, northern South America and equatorial east Africa. Taking into consideration current observations and climate forecast information, indications are that the following regions are at increased risk for disease outbreaks: Indonesia, Malaysia, Thailand and most of the southeast Asia Islands for increased dengue fever transmission and increased respiratory illness; Coastal Peru, Ecuador, Venezuela, and Colombia for increased risk of malaria; Bangladesh and coastal India for elevated risk of cholera; East Africa for increased risk of a Rift Valley fever outbreak and elevated malaria; southwest USA for increased risk for hantavirus pulmonary syndrome and plague; southern California for increased West Nile virus transmission; and northeast Brazil for increased dengue fever and respiratory illness. CONCLUSION: The current development of El Niño conditions has significant implications for global public health. Extremes in climate events with above normal rainfall and flooding in some regions and extended drought periods in other regions will occur. Forecasting disease is critical for timely and efficient planning of operational control programs. In this paper we describe developing global climate anomalies that suggest potential disease risks that will give decision makers additional tools to make rational judgments concerning implementation of disease prevention and mitigation strategies
- …