Molecular Mechanisms Orchestrating the Dynamics of Secretory Vesicle Pools.

The secretion of chemical messengers via Ca2+-dependent exocytosis of vesicles is fundamental to a wide-range of physiological events. Rab GTPases and SNARE proteins govern the temporal and spatial precision of transmitter release. Yet, little is known about their role in specifying the size and filling kinetics of functionally defined vesicle pools, which impact the strength and efficiency of exocytosis. We first sought to delineate the distinct vs. overlapping roles of highly homologous Rab GTPase proteins, Rab3 and Rab27, which display high sequence homology, share protein-effectors, and may functionally compensate. To define their actions, we overexpressed Rab3GAP and/or EPI64A GTPase-activating protein in wild-type or Rab27-null cells to transit the Rab3 family or Rab27A to a GDP-bound inactive state. We found Rab27A is essential for generation of the functionally defined immediately releasable pool, Rab3 is essential for a kinetically rapid filling of the RRP, and both cooperate in populating the readily releasable granule pool (RRP). We conclude that while Rab3 and Rab27A cooperate to generate release-ready vesicles in β-cells, they also direct unique kinetic and functional properties of the exocytotic pathway. We also investigated how the SNARE Tomosyn1 (Tomo1) regulates the partitioning of synaptic vesicle (SV) pools in hippocampal neurons. Tomo1 inhibits SV priming at the plasma membrane. Yet, its localization to SVs and cytosol uniquely positions it to coordinate SV pool partitioning. We that find that Tomo1 controls SV transition between the Resting Pool and Total Recycling Pool (TRP), and modulates the RRP size. Tomo1’s regulation of SV distribution between pools is sensitive to neural activity and requires Cdk5. We provide novel evidence for an interaction between Tomo1 and Rab3A-GTP, and through this with Synapsin1 proteins, known regulators of SV recruitment. In addition, Tomo1 regulatory control over the TRP occurred independent of its C-terminal SNARE domain. Hence, Tomo1 actions on neurotransmission extend beyond its known inhibition of SV priming into the RRP and may involve other effector proteins. Altogether, our results advance the understanding of how Rab and Tomosyn proteins coordinate steps of the vesicle cycle that lead to functional heterogeneity among vesicles and thus may determine modes of transmitter release.PHDNeuroscienceUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/116755/1/vcazares_1.pd

Disability Inclusive Transportation: Assessing First Mile Last Mile Conditions in the Richmond Region

Accessible public transportation services are vital to promoting a healthy, livable, and thriving region. For people with physical disabilities, the inability to access services and activities can have a harmful impact. A lack of personal mobility may lead to a decreased quality of life and the inability to advocate for one’s rights. Given the region\u27s growing population, as well as increased disability rates, providing accessible public transportation services is crucial. While public transportation services are required to be accessible under Title II of the Americans with Disabilities Act of 1990, supporting infrastructure oftentimes creates additional barriers. For example, poorly maintained sidewalks leading up to designated bus stops contribute to unsafe traveling conditions for people with disabilities. The purpose of the Disability Inclusive Transportation plan is to address these barriers, often referred to as First Mile Last Mile problems, to increase accessibility for individuals with physical impairments (i.e., visual, auditory, or ambulatory). Through a three-step methodology, this plan analyzes the nine localities in the Richmond region to better understand where there is a need for improvements, what barriers look like, and how they impact people with disabilities. This analysis is important for the Richmond region as it is experiencing rapid growth and development. The recommendations provided by this plan can be used to inform how the built environment should be integrated concurrently with development to enable more inclusive transportation systems

What makes a megaplasmid?

Naturally occurring plasmids come in different sizes. The smallest are less than a kilobase of DNA, while the largest can be over three orders of magnitude larger. Historically, research has tended to focus on smaller plasmids that are usually easier to isolate, manipulate and sequence, but with improved genome assemblies made possible by long-read sequencing, there is increased appreciation that very large plasmids—known as megaplasmids—are widespread, diverse, complex, and often encode key traits in the biology of their host microorganisms. Why are megaplasmids so big? What other features come with large plasmid size that could affect bacterial ecology and evolution? Are megaplasmids 'just' big plasmids, or do they have distinct characteristics? In this perspective, we reflect on the distribution, diversity, biology, and gene content of megaplasmids, providing an overview to these large, yet often overlooked, mobile genetic elements. This article is part of the theme issue ‘The secret lives of microbial mobile genetic elements’

Land Use and Operational Controls in the Planned Development

This Article takes a look at the historical development of land use controls and planned development; the internal organization and operational of a home owners\u27 association; and legal considerations in establishing effective and viable covenants, conditions, and restrictions

Virtual Stethoscope - Otoscope

The purpose of this report was to develop a working prototype for a virtual stethoscope and otoscope. Sponsored by Courtney Farr, the virtual diagnostic care system – HouseCalls Mobile digital stethoscope/otoscope is meant for use by medical professionals and non – medical professionals for preliminary medical exams while physically not in a medical setting. The HouseCalls Mobile device is to characterize key biometric parameters such as breathing patterns, heart irregularities, and visual clinical evaluation of the inner ear. This device is intended for pediatric use

Beer-spoilage Bacterial Strains in Large and Small Corporations in Breweries

Bacteria-spoilage strains are the root cause of unwanted flavors and unaesthetic appearances of beer. This accidental introduction of bacteria is causing economic loss to businesses and is affecting the health and loyalty of the breweries\u27 consumers. The two most studied strains are from the genera Pediococcus and Lactobacillus are a result of either primary or secondary contamination from the production process. Craft beers, such as Hazy Beers, produced by small-scale breweries are more prone to spoilage than commercial beers produced by large-scale breweries. The goal of this study is to test for the presence of bacteria-spoilage strains in small-scale breweries and large-scale breweries to determine if production size has a direct effect on bacterial growth in their final product. Using the spread plate technique, we inoculated two different media with six beer samples in an anaerobic environment and observed growth using the gram staining method to identify the strain by looking at the bacteria’s morphology under the microscope. Hazy Lady IPA, produced by Six Rivers Brewery, a small-scale brewery, was the only beer in our sample size that showed significant growth on both WLDs media showing significant Lactobacillus and Pediococcus bacterial contamination. Future studies should continue to explore the relationship between production size and bacterial contamination in larger sample sizes to determine if this correlation is unique to Humboldt County’s small-scale brewery, Six Rivers, or all small-scale breweries

Attitude, knowledge and perception of the altruistic donation of blood in a city in Northeastern Mexico

Objectives: To identify the causes due to which potential blood donors do not make voluntary donations: lack of knowledge, attitude, and the perception of blood donations as unwholesome. Materials and methods: We conducted a transversal, observational, descriptive, prospective, and a survey-based study of 435 subjects in Monterrey, Mexico in November of 2011. Results: 135 (31%) subjects were already donors, of which only 16 (3.6%) did it altruistically. Of the total amount of subjects, 161 (37%) were associated with some benefits from donating blood, 154 (35%) identified some kind of damage, the most mentioned was transmission of diseases with 77 (50%) mentions. The most common cause of refusal toward donation was ‘‘saving blood for a relative in need’’ with 137 (33%) mentions. Of the subjects surveyed, 55% (n = 240) refer having very few thoughts for donating blood voluntarily. Also, 360 (86%) subjects will donate without expecting something in return. Finally, 348 (80%) subjects do not remember seeing or hearing any kind of promotional information about altruistic blood donation. Conclusions: A great deal of people will donate blood altruistically without receiving any reward for doing so. 80% of the subjects do not remember seeing or hearing any kind of advertisement for blood donation which is proof of lack of adequate publicity. The analysis of perception of damages or benefits from blood donation will help in the development of more focused blood donation campaigns

Optimization of the investment casting process

Rapid prototyping is an important technique for manufacturing. This work refers to the manufacture of hollow patterns made of polymeric materials by rapid prototyping technologies for its use in the preparation of ceramic molds in the investment casting process. This work is focused on the development of a process for manufacturing patterns different from those that currently exist due to its hollow interior design, allowing its direct use in the fabrication of ceramic molds; avoiding cracking and fracture during the investment casting process, which is an important process for the foundry industry