Mini Baja Frame Analysis

The purpose of our senior design project is to optimize the Baja frame to reduce its weight and material cost while keeping the required rigidity. Through force analysis we will be able to determine if any rigidity is lost by removing a set of tubes (figure 1), along with the other forces seen by the frame. If it is found that the frame rigidity is still within the determined factor of safety, 2, then we will be able to reduce the frame weight and the number of tubes that make up the frame. Along with force analysis, we will use finite elemental analysis to manipulate dimensions and material to possibly reduce weight and cost

Electrically Enhanced Free Dendrite Growth in Polar and Non-polar Systems

We describe the electrically enhanced growth of needle crystals from the vapor phase, for which there exists a morphological instability above a threshold applied potential. Our improved theoretical treatment of this phenomenon shows that the instability is present in both polar and non-polar systems, and we provide an extension of solvability theory to include electrical effects. We present extensive experimental data for ice needle growth above the electrical threshold, where at $T=-5$C high-velocity shape-preserving growth is observed. These data indicate that the needle tip assumes an effective radius} $R^{\ast}$ which is nearly independent of both supersaturation and the applied potential. The small scale of $R^{\ast}$ and its response to chemical additives suggest that the needle growth rate is being limited primarily by structural instabilities, possibly related to surface melting. We also demonstrate experimentally that non-polar systems exhibit this same electrically induced morphological instability

Validity of Ultrasound Imaging of Abductor Hallucis Volume Demonstrated by Strong Agreement with MRI

Intrinsic foot muscles such as abductor hallucis (ABDH) are crucial for function and mobility while influencing quality of life. Thus, being able to accurately measure foot muscle volume is important. While magnetic resonance imaging (MRI) is often considered to be the reference standard of medical imaging, ultrasound (US) provides a cost effective, rapid and dynamic way of assessing muscle size and function. PURPOSE: To investigate the validity and intratester reliability of US imaging in assessing ABDH volume compared to MRI. METHODS: US and MRI were employed to measure the right and left ABDH muscle volume involving 9 participants (females = 3; males = 6). Muscle volume of the ABDH was calculated across the muscle belly every 0.5 cm both manually by utilizing a truncated cone (TC) formula and with a semi-automation tool in the Osirix (OX) software. Pearson product correlation (r), intraclass correlation coefficients (ICC), standard error of the measurement (SEm) and minimal detectable difference (MDD) were calculated. RESULTS: High correlations were detected between the US and MRI volume (cm3) measurements (r = 0.887) and between MRI TC and MRI OX (r = 0.986). Test reliability was excellent for both MRI and US measurements (ICC = 0.947 to 0.989). SEm value for the US was 0.409 cm3 with the percent SEm equal to 0.028%, while the SEm for MRI OX was 1.145 cm3 with a percent SEm of 0.072% and finally the SEm for MRI TC was 1.142 cm3 with a percent SEm of 0.071%. MDD value for the US was 1.135 cm3, while MRI OX MDD value was 3.174 cm3 and MRI TC MDD value was 3.166 cm3. CONCLUSIONS: US appears to be a valid and reliable alternative to MRI when measuring volume of the ABDH muscle. This method of US and MRI measurement can likely be used for assessing any of the deep small muscles of the foot

Model-Based Reverse Translation Between Veterinary and Human Medicine: The One Health Initiative

There is growing concern about the limitations of rodent models with regard to recapitulation of human disease pathogenesis. Computational modeling of data from humans and animals sharing similar diseases provides an opportunity for parallel drug development in human and veterinary medicine. This “reverse translational” approach needs to be supported by continuing efforts to refine the in silico tools that allow extrapolation of results between species

BYOE: Making Connections between Fluid Mechanics and Abstract Painting

This bring your own experiment (BYOE) paper details two iterations of a hands-on painting project that has been well-received by fluid mechanics students. In the conception of this project the authors have explored many of the relevant parameters for different painting techniques: drip painting, pendulum painting spray painting, and acrylic pours – one subset of which is spinning pours. These methods were explored both in terms of relevant fluid mechanic phenomenon as well as with hands-on experimentation, reviewing instructional videos and talking with artists. These efforts led to creation of short instructional videos that students can watch before undertaking their own attempts at creating a work of art. To date this project has been conducted as an extra credit opportunity, though discussion is presented on how the general idea could be deployed as a more traditional experimental lab or as a fun, yet relevant, end of semester lab activity. While the act of creating the fluid art inherently involves learning outcomes related to the importance of thinking creatively, exploring curiosity, prototyping and creating a product with limited project constraints, the instructor can determine the rigor of learning outcomes related to fluid mechanic principles with an accompanying written assignment. This BYOE paper is written with the goal of making the implementation of this project, or some variation of it, straightforward for instructors. Keeping material costs low was part of this consideration and set-up descriptions are provided as well as parts lists

Loss of Gata6 causes dilation of the hair follicle canal and sebaceous duct

The uppermost aspect of the hair follicle, known as the infundibulum or hair canal, provides a passageway for hair shaft egress and sebum secretion. Recent studies have indicated that the infundibulum and sebaceous ducts are lined by molecularly distinct differentiated cells expressing markers including Keratin 79 and Gata6. Here, we ablated Gata6 from the skin and observed dilation of both the hair canal and sebaceous ducts, independent of gender and hair cycle stage. Constitutive loss of Gata6 yielded only a mild delay in depilation‐induced entry into anagen, while unperturbed mutant mice possessed overtly normal skin and hair. Furthermore, we noted that Keratin 79 and Gata6 expression and localization did not depend upon each other. Our findings implicate Gata6 in maintaining the upper hair follicle and suggest that regulation of this transcription factor may be compromised in pathologies such as acne or infundibular cystic diseases that are characterized by abnormal expansion of this follicular domain.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149235/1/exd13757_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149235/2/exd13757-sup-0001-FigS1-S9.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149235/3/exd13757.pd

Greenhouse Gas and Noxious Emissions from Dual Fuel Diesel and Natural Gas Heavy Goods Vehicles.

Dual fuel diesel and natural gas heavy goods vehicles (HGVs) operate on a combination of the two fuels simultaneously. By substituting diesel for natural gas, vehicle operators can benefit from reduced fuel costs and as natural gas has a lower CO2 intensity compared to diesel, dual fuel HGVs have the potential to reduce greenhouse gas (GHG) emissions from the freight sector. In this study, energy consumption, greenhouse gas and noxious emissions for five after-market dual fuel configurations of two vehicle platforms are compared relative to their diesel-only baseline values over transient and steady state testing. Over a transient cycle, CO2 emissions are reduced by up to 9%; however, methane (CH4) emissions due to incomplete combustion lead to CO2e emissions that are 50-127% higher than the equivalent diesel vehicle. Oxidation catalysts evaluated on the vehicles at steady state reduced CH4 emissions by at most 15% at exhaust gas temperatures representative of transient conditions. This study highlights that control of CH4 emissions and improved control of in-cylinder CH4 combustion are required to reduce total GHG emissions of dual fuel HGVs relative to diesel vehicles.The authors would like to acknowledge support from the UK Engineering and Physical Sciences Research Council (EP/K00915X/1), the UK Department for Transport, the Office for Low Emission Vehicles and Innovate UK (project reference: 400266) and the industrial partners of the Centre for Sustainable Road Freight.This is the final version of the article. It first appeared from the American Chemical Society via http://dx.doi.org/10.1021/acs.est.5b0424

Contracting Out: A Study of the Honduran Experience

This study was conducted by the National Association of Schools of Public Affairs and Administration (NASPAA) at the request of USAID/Honduras under the terms of NASPAA\u27s Technical Cooperative Agreement with USAID. The study examined the experiences of USAID/Honduras and the Government of Honduras with the contracting out of construction activities in three sectors. The purpose of the study was to document empirical evidence regarding the performance of contracting out as a policy measure to increase private sector initiatives in Honduras

Selective and regulated trapping of nicotinic receptor weak base ligands and relevance to smoking cessation

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in eLife 6 (2017): e25651, doi:10.7554/eLife.25651.To better understand smoking cessation, we examined the actions of varenicline (Chantix) during long-term nicotine exposure. Varenicline reduced nicotine upregulation of α4β2-type nicotinic receptors (α4β2Rs) in live cells and neurons, but not for membrane preparations. Effects on upregulation depended on intracellular pH homeostasis and were not observed if acidic pH in intracellular compartments was neutralized. Varenicline was trapped as a weak base in acidic compartments and slowly released, blocking 125I-epibatidine binding and desensitizing α4β2Rs. Epibatidine itself was trapped; 125I-epibatidine slow release from acidic vesicles was directly measured and required the presence of α4β2Rs. Nicotine exposure increased epibatidine trapping by increasing the numbers of acidic vesicles containing α4β2Rs. We conclude that varenicline as a smoking cessation agent differs from nicotine through trapping in α4β2R-containing acidic vesicles that is selective and nicotine-regulated. Our results provide a new paradigm for how smoking cessation occurs and suggest how more effective smoking cessation reagents can be designed.This work was supported by National Institutes of Health RO1DA 035430 and a Pilot Project from the University of Chicago Can- cer Center

Surface and lightning sources of nitrogen oxides over the United States: Magnitudes, chemical evolution, and outflow

We use observations from two aircraft during the ICARTT campaign over the eastern United States and North Atlantic during summer 2004, interpreted with a global 3-D model of tropospheric chemistry (GEOS-Chem) to test current understanding of regional sources, chemical evolution, and export of NOx. The boundary layer NOx data provide top-down verification of a 50% decrease in power plant and industry NOx emissions over the eastern United States between 1999 and 2004. Observed NOx concentrations at 8–12 km altitude were 0.55 ± 0.36 ppbv, much larger than in previous U.S. aircraft campaigns (ELCHEM, SUCCESS, SONEX) though consistent with data from the NOXAR program aboard commercial aircraft. We show that regional lightning is the dominant source of this upper tropospheric NOx and increases upper tropospheric ozone by 10 ppbv. Simulating ICARTT upper tropospheric NOx observations with GEOS-Chem requires a factor of 4 increase in modeled NOx yield per flash (to 500 mol/ flash). Observed OH concentrations were a factor of 2 lower than can be explained from current photochemical models, for reasons that are unclear. A NOy-CO correlation analysis of the fraction f of North American NOx emissions vented to the free troposphere as NOy (sum of NOx and its oxidation products) shows observed f = 16 ± 10% and modeled f = 14 ± 9%, consistent with previous studies. Export to the lower free troposphere is mostly HNO3 but at higher altitudes is mostly PAN. The model successfully simulates NOy export efficiency and speciation, supporting previous model estimates of a large U.S. anthropogenic contribution to global tropospheric ozone through PAN export