702 research outputs found
Reluctance Accelerator Efficiency Optimization via Pulse Shaping
Reluctance accelerators are used to apply linear forces to ferromagnetic projectiles via solenoids. Ef ciency increases for a single-stage reluctance accelerator were produced by manipulating the input current pulse supplied by a discharging capacitor. The development of a theoretical model allowed for the calculation of optimized pulse shapes. A digital pulsewidth modulated switching method was used to control the current pulse shape using an Arduino Uno microcontroller, which supplied signals to the gate of a MOSFET transistor that controlled the current to the system solenoid. An ef ciency increase of 5.7% was obtained for a reluctance accelerator with an optimized current pulse shape in comparison to a capacitor discharge with no pulse shapin
Sticker Price Elasticity as Predictor of Tuition Reset Success: A Quantitative Approach
Few quantitative studies exist on tuition outcomes resets despite increasing frequency and interest among industry practitioners. The purpose of this study is to examine the relationship between sticker price elasticity and changes in first-year student enrollment, net tuition and fee revenue from first-year students, percent of first-year students who are Pell-eligible, and changes in transfer student enrollment using multivariate logistic and linear regression models. The independent variable is the sticker price elasticity of demand from two years preceding the announcement of a reset.
This study contributes to the literature by adding to evidence regarding the signaling role of sticker price in higher education and provides a template for future studies regarding the impact of tuition resets. For industry practitioners, this study provides an overview of tuition reset outcomes and indicators of the suitability of tuition resets as a strategy at the institutional level. This study finds sticker price elasticity is a poor predictor of tuition reset success. Increases to advertising spending and gains in net assets in the years prior to the reset are more consistent predictors of success. This study also finds no evidence of a direct correlation or of “threshold effects” between the size of a reset and the number of first-year students enrolled or net tuition and fee revenue increases.
The study concludes with applications of findings and recommendations for future research with emphasis on the role of advertising as a mechanism to explain the rationale for resetting
Livestock density as risk factor for livestock-associated methicillin-resistant Staphylococcus aureus, the Netherlands
To determine whether persons living in areas of high animal density are at increased risk for carrying livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA), we used an existing dataset of persons in the Netherlands with LA-MRSA carriage and controls who carried other types of MRSA. Results of running univariate and multivariate logistic regression models indicated that living in livestock-dense areas increases the odds of nasal carriage of LA-MRSA. We found that doubling pig, cattle, and veal calf densities per municipality increased the odds of LA-MRSA carriage over carriage of other types of MRSA by 24.7% (95% CI 0.9%–54.2%), 76.9% (95% CI 11.3%–81.3%), and 24.1% (95% CI 5.5%–45.9%), respectively, after adjusting for direct animal contact, living in a rural area, and the probable source of MRSA carriage. Controlling the spread of LA-MRSA thus requires giving attention to community members in animal-dense regions who are unaffiliated with livestock farming
Hydrated lime matrix decreases ruminal biohydrogenation of flaxseed fatty acids
Omega-3 fatty acids are essential nutrients for humans, but dietary intake of these
nutrients by many Americans is inadequate due to low consumption of omega-3-rich
foods such as fish, walnuts, and flaxseed. In contrast, per capita consumption of red
meat is relatively high, but these products normally contain only small amounts of
omega-3 fatty acids. Feeding cattle diets that contain omega-3 fatty acids has consistently
increased the proportion of the desirable fats that accumulate in beef. Unfortunately,
the proportion of dietary omega-3 fats that are deposited into beef tissues is
relatively low, because microorganisms within the rumen biohydrogenate the unsaturated
omega-3 fatty acids extensively to produce the saturated fats that are characteristic
of beef fat. Encapsulation of fats has been proposed as a method for improving efficiency
of transfer of omega-3 fats into beef. Encapsulation processes apply a protective
barrier on the surface of fats or fat-containing feeds, which theoretically decreases fats’
susceptibility to microbial biohydrogenation. Protective coatings must remain intact to
retain their functionality, and physical damage to the coatings that occurs with normal
handling can result in poor efficacy because the core material is exposed to microorganisms
in the rumen. Embedding feed particles within a homogeneous protective matrix
constitutes a potentially useful alternative to protective surface barriers. The matrix is
created by mixing feed particles that are to be protected with a suitable matrix material
that is resistant to microbial digestion and subsequently forming the mixture into pills.
In cases where physical damage occurs, exposure of the core material is confined to the
broken surface, and the remainder of the matrix retains its ruminal stability.
The objective of this study was to determine if embedding flaxseed within a matrix of
hydrated dolomitic lime could be used as a method to decrease biohydrogenation of
polyunsaturated omega-3 fatty acids, thus improving efficiency of omega-3 fatty acids
absorption into the bloodstream
Self-sampling is appropriate for detection of Staphylococcus aureus: a validation study
<p>Abstract</p> <p>Background</p> <p>Studies frequently use nasal swabs to determine <it>Staphylococcus aureus</it> carriage. Self-sampling would be extremely useful in an outhospital research situation, but has not been studied in a healthy population. We studied the similarity of self-samples and investigator-samples in nares and pharynxes of healthy study subjects (hospital staff) in the Netherlands.</p> <p>Methods</p> <p>One hundred and five nursing personnel members were sampled 4 times in random order after viewing an instruction paper: 1) nasal self-sample, 2) pharyngeal self-sample, 3) nasal investigator-sample, and 4) pharyngeal investigator-sample.</p> <p>Results</p> <p>For nasal samples, agreement is 93% with a kappa coefficient of 0.85 (95% CI 0.74-0.96), indicating excellent agreement, for pharyngeal samples agreement is 83% and the kappa coefficient is 0.60 (95% CI 0.43-0.76), indicating good agreement. In both sampling sites self-samples even detected more <it>S. aureus</it> than investigator-samples.</p> <p>Conclusions</p> <p>This means that self-samples are appropriate for detection of <it>Staphylococcus aureus</it> and methicillin-resistant <it>Staphylococcus aureus</it>.</p
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