7,264 research outputs found
A heterogeneous "resting" pool of synaptic vesicles that is dynamically interchanged across boutons in mammalian CNS synapses
Using pHluorin-tagged synaptic vesicle proteins we have examined the partitioning of these probes into recycling and nonrecycling pools at hippocampal nerve terminals in cell culture. Our studies show that for three of the major synaptic vesicle components, vGlut-1, VAMP-2, and Synaptotagmin I, approximately 50-60% of the tagged protein appears in a recycling pool that responds readily to sustained action potential stimulation by mobilizing and fusing with the plasma membrane, while the remainder is targeted to a nonrecycling, acidic compartment. The fraction of recycling and nonrecycling (or resting) pools varied significantly across boutons within an individual axon, from 100% resting (silent) to 100% recycling. Single-bouton bleaching studies show that recycling and resting pools are dynamic and exchange between synaptic boutons. The quantitative parameters that can be extracted with the approaches outlined here should help elucidate the potential functional role of the resting vesicle pool
A heterogeneous "resting" pool of synaptic vesicles that is dynamically interchanged across boutons in mammalian CNS synapses
Using pHluorin-tagged synaptic vesicle proteins we have examined the partitioning of these probes into recycling and nonrecycling pools at hippocampal nerve terminals in cell culture. Our studies show that for three of the major synaptic vesicle components, vGlut-1, VAMP-2, and Synaptotagmin I, approximately 50-60% of the tagged protein appears in a recycling pool that responds readily to sustained action potential stimulation by mobilizing and fusing with the plasma membrane, while the remainder is targeted to a nonrecycling, acidic compartment. The fraction of recycling and nonrecycling (or resting) pools varied significantly across boutons within an individual axon, from 100% resting (silent) to 100% recycling. Single-bouton bleaching studies show that recycling and resting pools are dynamic and exchange between synaptic boutons. The quantitative parameters that can be extracted with the approaches outlined here should help elucidate the potential functional role of the resting vesicle pool
k-d Tree-Segmented Block Truncation Coding for Image Compression
Block truncation coding (BTC) is a class of image compression algorithms whose main technique is the partitioning of an image into pixel blocks that are then each encoded using a representative set of pixel values. It is commonly used because of its simplicity and low computational complexity. The Quadtree-segmented BTC (QTS-BTC), which utilizes a dynamic hierarchical segmentation technique, is among the most efficient in the BTC class. In this study, we propose a new BTC variant that introduces two ideas: (1) the use of a k-d tree for segmentation and (2) the use of a Mean Squared Error (MSE) threshold for dynamically determining the granularity of the blocks. We refer to this new BTC variant as the k-d Tree Segmented BTC (KTS-BTC), and we test this against some of the existing BTC variants by running the algorithms on a standard image compression dataset. The results show that the proposed variant yields low bit rates of the compressed images, even outperforming the state-of-the-art QTS-BTC, without a significant reduction in image quality as measured using the Peak Signal-to-Noise Ratio (PSNR). The utilization of k-d tree for image segmentation is further shown to have more impact than that of employing the MSE thresholding scheme as a block activity classifier
E.M.B.E.R. Home Protection
Despite the increased danger of wildfires in states such as California and Colorado, there is yet to exist a product that can autonomously extinguish the spot fires that ignite from windblown embers. This device could reduce countless civilian casualties and prevent millions of dollars in property damage. This is not to mention allowing homeowners to evacuate with a greater peace of mind. Mass ownership of this product would be analogous to the “herd immunity” of vaccines, where neighbors ultimately protect each other and save money through self-insurance.
There are products on the market, generally in the commercial domain, that can protect a building from wildfire. However, these devices come at a high cost that eliminates even the upper-middle class household. The device we are building is unlike anything in current existence because it utilizes thermal imaging technology to reduce the water consumption related to firefighting.
Through brainstorming and research, an understanding of the scope and specifications involved with this project was developed. These ideas were compiled and compared using various decision-making tools. After working our ideations into one solid design, we performed the necessary analyses and gathered parts and materials. The physical components were manufactured and assembled to create a stationary rotating device with a vertical array of sprinkler nozzles. Upon completion of the mechanical system, it was integrated with an electronic assembly that uses a single-board computer to analyze thermal imaging data from a FLIR camera, control rotation of the device, and dispense water in the appropriate direction
Urinalysis Screening for Rural Communities
Access to medical care and health screenings is a necessity for patients around the globe, but it can be difficult to provide this without screenings becoming costly or convoluted. In rural and underdeveloped areas, patients are often disadvantaged when it comes to finding reliable and affordable healthcare. The isolation provided by their location and the rising costs of physicians makes it impossible for most impoverished communities to attain personalized care. Because of this, treatable diseases often go unaddressed, allowing diseases to progress to a critical condition. Mortality rates have shown to be higher in communities located in rural areas and among destitute economies. Telemedicine is one solution to improve rural health care by allowing patients to have remote access to health services. Our goal for this project would be to provide simple and fast diagnosis to detect urine albumin levels, urobilinogen, nitrite, as well as pH and glucose levels combined with telemedicine to provide reliable results.
Thus far, we have completed tests for the previously mentioned parameters and have reached out to the World Health Partners in order to propose collaboration on the project. We have also reached out to the Computer Engineering team in order to normalize the images captured by the diagnostic device. Once the project reaches its conclusion, we believe that the introduction of this device into rural areas would effectively monitor patient health as well as improve the overall quality of life for those in impoverished conditions
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Mentoring the Mentors: Implementation and Evaluation of Four Fogarty-Sponsored Mentoring Training Workshops in Low-and Middle-Income Countries.
A growing body of evidence highlights the importance of competent mentoring in academic research. We describe the development, implementation, and evaluation of four regional 2-day intensive workshops to train mid- and senior-level investigators conducting public health, clinical, and basic science research across multiple academic institutions in low- and middle-income countries (LMICs) on tools and techniques of effective mentoring. Sponsored by the Fogarty International Center, workshops included didactic presentations, interactive discussions, and small-group problem-based learning and were conducted in Lima, Peru; Mombasa, Kenya; Bangalore, India; and Johannesburg, South Africa, from 2013 to 2016. Mid- or senior-level faculty from multiple academic institutions within each region applied and were selected. Thirty faculty from 12 South America-based institutions, 29 faculty from eight East Africa-based institutions, 37 faculty from 14 South Asia-based institutions, and 36 faculty from 13 Africa-based institutions participated, with diverse representation across disciplines, gender, and academic rank. Discussions and evaluations revealed important comparisons and contrasts in the practice of mentoring, and specific barriers and facilitators to mentoring within each cultural and regional context. Specific regional issues related to hierarchy, the post-colonial legacy, and diversity arose as challenges to mentoring in different parts of the world. Common barriers included a lack of a culture of mentoring, time constraints, lack of formal training, and a lack of recognition for mentoring. These workshops provided valuable training, were among the first of their kind, were well-attended, rated highly, and provided concepts and a structure for the development and strengthening of formal mentoring programs across LMIC institutions
Planetary Science Goals for the Spitzer Warm Era
The overarching goal of planetary astronomy is to deduce how the present collection of objects found in our Solar System were formed from the original material present in the proto-solar nebula. As over two hundred exo-planetary systems are now known, and multitudes more are expected, the Solar System represents the closest and best system which we can study, and the only one in which we can clearly resolve individual bodies other than planets. In this White Paper we demonstrate how to use Spitzer Space Telescope InfraRed Array Camera Channels 1 and 2 (3.6 and 4.5 µm) imaging photometry with large dedicated surveys to advance our knowledge of Solar System formation and evolution. There are a number of vital, key projects to be pursued using dedicated large programs that have not been pursued during the five years of Spitzer cold operations. We present a number of the largest and most important projects here; more will certainly be proposed once the warm era has begun, including important observations of newly discovered objects
The medicinal plant Tabebuia impetiginosa potently reduces pro-inflammatory cytokine responses in primary human lymphocytes
Bark from the Handroanthus impetiginosus (Mart. ex DC.) Mattos (Bignoniaceae) tree has long been used in traditional South American healing practises to treat inflammation. However, its anti-inflammatory activity has not been closely examined. Here we use chemical extraction, qualitative phytochemical examination, toxicity testing and quantitative examination of anti-inflammatory activity on human cells ex vivo. All extracts were found to be nontoxic. We found different extracts exhibited unique cytokine profiles with some extracts outperforming a positive control used in the clinic. These results verify the immunomodulatory activity of Handroanthus impetiginosus (Mart. ex DC.) Mattos (Bignoniaceae) tree bark-derived compounds. Collectively, combining a lack of toxicity and potency in human immune cells supports further fractionation and research
ARDA: Automatic Relational Data Augmentation for Machine Learning
Automatic machine learning (\AML) is a family of techniques to automate the
process of training predictive models, aiming to both improve performance and
make machine learning more accessible. While many recent works have focused on
aspects of the machine learning pipeline like model selection, hyperparameter
tuning, and feature selection, relatively few works have focused on automatic
data augmentation. Automatic data augmentation involves finding new features
relevant to the user's predictive task with minimal ``human-in-the-loop''
involvement.
We present \system, an end-to-end system that takes as input a dataset and a
data repository, and outputs an augmented data set such that training a
predictive model on this augmented dataset results in improved performance. Our
system has two distinct components: (1) a framework to search and join data
with the input data, based on various attributes of the input, and (2) an
efficient feature selection algorithm that prunes out noisy or irrelevant
features from the resulting join. We perform an extensive empirical evaluation
of different system components and benchmark our feature selection algorithm on
real-world datasets
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