Rural Surgery Training Programs in the United States: A Review of the Literature

RURAL SURGERY TRAINING PROGRAMS IN THE UNITED STATES: A REVIEW OF THE LITERATURE Abstract: Rural surgery training programs have been developed to train general surgeons for community and rural service. There are 10 rural surgery training programs in the United States. Rural surgery training began in 1974 in LaCrosse, Wisconsin to prepare general surgery residents for rural service. There is a national shortage of general surgeons which translates into a deficit of surgeons in rural areas. The terms “general surgeon” and “rural surgeon” are not synonymous as rural surgery is more extensive, more broad-based and more subspecialty with more trauma, burn care and wound care and far more endoscopic and laparoscopic procedures. There are many advantages to rural general surgery training programs. A well-trained rural surgeon with OB/GYN experience can handle 66% of all inpatient operations in a rural hospital. Rural surgery programs have been developed to address the above problems and attract graduating general surgeons to communities and rural areas. These programs have had high general surgery practice and high rural placement. Selection of appropriate campus, hospital and attending staff is critical for the educational experience to be maximal. Attending surgeons need to be general surgeons, rural surgeons and subspecialty surgeons. The American College of Surgeons (ACS) has developed the Advisory Council for Rural Surgery (ACRS). The ACRS has developed a repository of rural training experiences and training sites. There are five different types of training experience ranging from rotations to dedicated tracks to fellowships. Rural surgery training programs are a mechanism to attract more medical students to general surgery residencies, more graduating chief general surgery residents to private practice in community and rural areas, improve the case numbers and confidence of graduating surgery residents, and improve the quality of surgical care in this country

Measuring the Ellipticity of M 87* Images

The Event Horizon Telescope (EHT) images of the supermassive black hole at the center of the galaxy M 87 provided the first image of the accretion environment on horizon scales. General relativity predicts that the image of the shadow should be nearly circular, given the inclination angle of the black hole M 87*. A robust detection of ellipticity in the image reconstructions of M 87* could signal new gravitational physics on horizon scales. Here we analyze whether the imaging parameters used in EHT analyses are sensitive to ring ellipticity and measure the constraints on the ellipticity of M 87*. We find that the top set is unable to recover ellipticity. Even for simple geometric models, the true ellipticity is biased low, preferring circular rings. Therefore, to place a constraint on the ellipticity of M 87*, we measure the ellipticity of 550 simulated data sets of GRMHD simulations. We find that images with intrinsic axis ratios of 2:1 are consistent with the ellipticity seen from the EHT image reconstructions.Comment: accepted for publication to Ap

Hydrodynamical Simulations of the Lyman Alpha Forest: Model Comparisons

We investigate the properties of the Lyman alpha forest as predicted by numerical simulations for a range of currently viable cosmological models. This is done in order to understand the dependencies of the forest on cosmological parameters. Focusing on the redshift range from two to four, we show that: (1) most of the evolution in the distributions of optical depth, flux and column density can be understood by simple scaling relations, (2) the shape of optical depth distribution is a sensitive probe of the amplitude of density fluctuations on scales of a few hundred kpc, (3) the mean of the b distribution (a measure of the width of the absorption lines) is also very sensitive to fluctuations on these scales, and decreases as they increase. We perform a preliminary comparison to observations, where available. A number of other properties are also examined, including the evolution in the number of lines, the two-point flux distribution and the HeII opacity.Comment: 37 pages, 21 figures, submitted to Ap

Epigenome-wide association study of physical activity and physiological parameters in discordant monozygotic twins

An epigenome-wide association study (EWAS) was performed on buccal cells from monozygotic-twins (MZ) reared together as children, but who live apart as adults. Cohorts of twin pairs were used to investigate associations between neighborhood walkability and objectively measured physical activity (PA) levels. Due to dramatic cellular epigenetic sex differences, male and female MZ twin pairs were analyzed separately to identify differential DNA methylation regions (DMRs). A priori comparisons were made on MZ twin pairs discordant on body mass index (BMI), PA levels, and neighborhood walkability. In addition to direct comparative analysis to identify specific DMRs, a weighted genome coexpression network analysis (WGCNA) was performed to identify DNA methylation sites associated with the physiological traits of interest. The pairs discordant in PA levels had epigenetic alterations that correlated with reduced metabolic parameters (i.e., BMI and waist circumference). The DNA methylation sites are associated with over fifty genes previously found to be specific to vigorous PA, metabolic risk factors, and sex. Combined observations demonstrate that behavioral factors, such as physical activity, appear to promote systemic epigenetic alterations that impact metabolic risk factors. The epigenetic DNA methylation sites and associated genes identified provide insight into PA impacts on metabolic parameters and the etiology of obesity

Impact of Mineral Dust on Nitrate, Sulfate, and Ozone in Transpacific Asian Pollution Plumes

We use a 3-D global chemical transport model (GEOS-Chem) to interpret aircraft observations of nitrate and sulfate partitioning in transpacific dust plumes during the INTEX-B campaign of April–May 2006. The model includes explicit transport of size-resolved mineral dust and its alkalinity, nitrate, and sulfate content. The observations show that particulate nitrate is primarily associated with dust, sulfate is primarily associated with ammonium, and Asian dust remains alkaline across the Pacific. This can be reproduced in the model by using a reactive uptake coefficient for $HNO_3$ on dust $(\gamma(HNO_3) \sim10^{−3})$ much lower than commonly assumed in models and possibly reflecting limitation of uptake by dust dissolution. The model overestimates gas-phase $HNO_3$ by a factor of 2–3, typical of previous model studies; we show that this cannot be corrected by uptake on dust. We find that the fraction of aerosol nitrate on dust in the model increases from ~30% in fresh Asian outflow to 80–90% over the Northeast Pacific, reflecting in part the volatilization of ammonium nitrate and the resulting transfer of nitrate to the dust. Consumption of dust alkalinity by uptake of acid gases in the model is slow relative to the lifetime of dust against deposition, so that dust does not acidify (at least not in the bulk). This limits the potential for dust iron released by acidification to become bio-available upon dust deposition. Observations in INTEX-B show no detectable ozone depletion in Asian dust plumes, consistent with the model. Uptake of $HNO_3$ by dust, suppressing its recycling to $NO_x$, reduces Asian pollution influence on US surface ozone in the model by 10–15% or up to 1 ppb.Engineering and Applied Science

Neuroregulation of protein synthesis in odontoblasts of the first molar of the rat after wounding

Odontoblasts respond to occlusal trauma by increased elaboration of a matrix which is subsequently calcified to form reparative dentin. The purpose of the present study was to analyze quantitatively and compare the ability of odontoblasts to synthesize collagen after wounding in rats with an intact innervation (baseline) and in rats with sensory (inferior alveolar nerve, IAN) and/or sympathetic (superior cervical ganglion, SCG) surgical denervation. Surgery was performed 7 days prior to wounding. All rats had 1 mm of enamel and dentin removed from the occlusal surface of the first mandibular molar (resected side) with the contralateral tooth serving as a control. Rats were killed 1 h after injection with 3 H-proline on days 0, 5, 10 or 15 after wounding, and mandibles were removed and processed for autoradiography. Grain counts were performed over odontoblasts throughout the pulp horns for each time period and for control and experimental molars in intact (baseline) and denervated groups. When compared to the control baseline, the experimental baseline data showed increased 3 -proline uptake throughout the study with a peak at 5 days. When compared to the baseline data, IAN and SCG results demonstrated a delay or attenuation of the protein synthetic response. The results indicate that the sensory and sympathetic neural components may regulate odontoblastic response to wounding.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47683/1/441_2005_Article_BF01239971.pd

North American Influence on Tropospheric Ozone and the Effects of Recent Emission Reductions: Constraints from ICARTT Observations

We use observations from the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign over eastern North America in summer 2004, interpreted with a global 3‐D model of tropospheric chemistry (GEOS‐Chem), to improve and update estimates of North American influence on global tropospheric ozone and the effect of recent U.S. anthropogenic reductions on surface ozone pollution. We find that the 50% decrease in U.S. stationary NOx sources since 1999 has decreased mean U.S. boundary layer ozone concentrations by 6–8 ppbv in the southeast and 4–6 ppbv in the Midwest. The observed dO3/dCO molar enhancement ratio in the U.S. boundary layer during ICARTT was 0.46 mol mol−1, larger than the range of 0.3–0.4 from studies in the early 1990s, possibly reflecting the decrease in the NOx/CO emission ratio as well as an increase in the ozone production efficiency per unit NOx. North American NOx emissions during summer 2004 as constrained by the ICARTT observations (0.72 Tg N fossil fuel, 0.11 Tg N biomass burning, 0.28 Tg N lightning for 1 July to 15 August) enhanced the hemispheric tropospheric ozone burden by 12.4%, with comparable contributions from fossil fuel and lightning (5–6%), but only 1% from biomass burning emissions despite 2004 being a record fire year over Alaska and western Canada.Earth and Planetary Science

Photoacoustic dose monitoring in clinical high-energy photon beams

This work describes all stages of development (setup, optimization, performance, and first experimental measurements) of an acoustic sensor that can be used for range monitoring and dosimetry of clinical radiotherapy beams. The detection device consists of an ultrasonic transducer, a combination of preamplifiers and differential amplifiers with filtered outputs and a digital oscilloscope. Simulations of the experimental setup were carried out to study the optimal measurement geometry and choice of transducer. The dose distributions were calculated with the Monte Carlo code FLUKA, while the acoustic simulations were performed with the analytical wave transport code k-Wave. The temporal profiles of the dose pulses, in the order of mu s, were measured with a scintillating crystal coupled to a photomultiplier and used as input for the acoustic simulation. Measurements were performed in a Cyberknife (TM) radiosurgery beam and a TrueBeam unit. A lead block was submerged in water and placed partially or totally in the irradiation field in order to increase the acoustic signal. Photoacoustic signals were detected with both beams with the expected shape and time-delay, after the frequency response of the detection system was taken into account. The proposed setup can detect photoacoustic signals originating from the penumbra of the treatment fields after being processed with the appropriate image analysis tools