bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rates of Return to Four‐Year University Education: An Application of Regression Discontinuity Design
Authors: Fan Elliott , Meng Xin , Wei Zhichao , Zhao Guochang 
Published: April 2017

AbstractIt is invariably difficult to estimate the rate of return to university education, because of the problem of omitted variable bias. Using a regression discontinuity design, we estimate the effect of a four‐year university education on earnings, and we explore the pathways through which the effect operates. Our estimation exploits the centralized, score‐based college/university admission system in China, where the minimum scores required for university admission are externally determined by the provincial governments. Our findings suggest that being eligible for four‐year university admission implies a sizable increase in earnings. The payoff can be attributed to the prolonged length of education and improvements in education quality, although the quality effects cannot be precisely estimated.
Carriers of Change and Continuity: New Restaurants in Amsterdam
Authors: Terhorst Pieter , Erkuş‐Öztürk Hilal 
Published: April 2017

AbstractThis paper analyses new firm formation in the Amsterdam restaurant industry, on the basis of an in‐depth research of 37 new restaurants, through the lens of the theory of evolutionary economic geography. The findings show that restaurateur‐chefs largely replicate the kitchen of their parent firms whereas restaurateur‐managers can more easily switch to a different type of kitchen. It means that replication of individual knowledge and skills are more important than replication of routines. Restaurateurs who came from other related industries did not bring something special from their former jobs in their restaurants. In addition, new restaurants benefit differently from extra‐firm relations (with respect to attracting capital, monitoring other restaurants, finding chefs and cooks, relations with suppliers and media) during their start‐up process and thereafter. Those extra‐firm relations are found at the local, national, and global scale.
Effect of Physical Activity Intervention in Prediabetes: A Systematic Review With Meta-analysis
Authors: Jadhav Radhika Aditya , Hazari Animesh , Monterio Ashma , Kumar Sampath , Maiya Arun G. 
Published: April 2017

Background:Prediabetes is a strong risk factor for the development of Type2 Diabetes Mellitus (T2DM). Modification in lifestyle plays an important role to avoid the prognosis of T2DM and its complications in future. The aim of our study was to focus on the effectiveness of physical activity (PA) intervention program on different outcome measures in individuals with prediabetes. The effort of the present review was to contribute to the existing literature by strengthening the evidence pointing toward the positive impact of physical activity in individuals with prediabetes.Methods:Studies have been identified through database like PubMed, Scopus, and ProQuest. Randomized and nonrandomized controlled trials have been included. Nineteen articles have been selected for the qualitative analysis and 08 for meta-analysis.Results:PA intervention showed a favorable effect on improving oral glucose tolerance (Risk ratio [RR] –0.26, 95% CI –0.06 to 0.07) and fasting blood sugar (RR –0.05, 95% CI –0.14 to 0.04). It also showed the favorable effect on glycated hemoglobin (HbA1C), maximum oxygen uptake (VO2max), and body composition.Conclusion:Present review suggests that the PA promotion and participation can help to slow down the progression of disease in individuals with prediabetes and thus reduces the morbidity and mortality associated with T2DM.
Effectiveness of a Home-Based Eccentric-Exercise Program on the Torque-Angle Relationship of the Shoulder External Rotators: A Pilot Study
Authors: Uhl Timothy L. , Rice Thomas , Papotto Brianna , Butterfield Timothy A. 
Published: April 2017

Context:The role of the rotator cuff is to provide dynamic stability to the glenohumeral joint. Human and animal studies have identified sarcomerogenesis as an outcome of eccentric training indicated by more torque generation with the muscle in a lengthened position.Objective:The authors hypothesized that a home-based eccentric-exercise program could increase the shoulder external rotators’ eccentric strength at terminal internal rotation (IR).Design:Prospective case series.Setting:Clinical laboratory and home exercising.Participants:10 healthy subjects (age 30 ± 10 y).Intervention:All participants performed 2 eccentric exercises targeting the posterior shoulder for 6 wk using a home-based intervention program using side-lying external rotation (ER) and horizontal abduction.Main Outcome Measures:Dynamic eccentric shoulder strength measured at 60°/s through a 100° arc divided into 4 equal 25° arcs (ER 50–25°, ER 25–0°, IR 0–25°, IR 25–50°) to measure angular impulse to represent the work performed. In addition, isometric shoulder ER was measured at 5 points throughout the arc of motion (45° IR, 30° IR, 15° IR, 0°, and 15° ER). Comparison of isometric and dynamic strength from pre- to posttesting was evaluated with a repeated-measure ANOVA using time and arc or positions as within factors.Results:The isometric force measures revealed no significant differences between the 5 positions (P = .56). Analysis of the dynamic eccentric data revealed a significant difference between arcs (P = .02). The percentage-change score of the arc of IR 25–50° was found to be significantly greater than that of the arc of IR 0–25° (P = .007).Conclusion:After eccentric training the only arc of motion that had a positive improvement in the capacity to absorb eccentric loads was the arc of motion that represented eccentric contractions at the longest muscle length.
Effect of Zr on the microstructures and mechanical properties of as-extruded Mg–2.3Zn–0.18Y–xZr alloys
Authors: Wang Yufan , Zhang Yingbo , Gao Wei 
Published: April 2017

The microstructures and mechanical properties of as-extruded Mg–2.3Zn–0.18Y–[Formula: see text]Zr ([Formula: see text] = 0.03, 0.06 and 0.13 at.%) alloys and aged Mg–2.3Zn–0.18Y–0.13Zr alloy were studied. The results revealed that the microstructures of as-extruded Mg–2.3Zn–0.18Y–[Formula: see text]Zr alloys are typical bimodal structures. The coarse [Formula: see text]-Mg grains are surrounded by fine dynamically recrystallized [Formula: see text]-Mg grains. The average size of [Formula: see text]-Mg grains decreases with increasing Zr content. Moreover, the addition of Zr (at.%) can improve the mechanical properties of alloy. The as-extruded Mg–2.3Zn–0.18Y–0.13Zr alloy has the best mechanical properties with ultimate tensile strength (UTS) and yield strength (YS) of 346 MPa and 292 MPa, respectively, and an elongation of 26.7%, which can be attributed to the grain refining effect and precipitate strengthening. The UTS and elongation of Mg–2.3Zn–0.18Y–0.13Zr alloy changed slightly after aging treatment, but the YS increases remarkably, with the maximum increase of 30 MPa. The fracture surfaces of all alloys consist of many tearing ridges and dimples.
The solidification and precipitation behaviors of AE42 magnesium alloy
Authors: Liao Huimin , Yang Gang , Zeng Ming , Wang Xiaoli 
Published: April 2017

The solidification and precipitation behaviors of AE42 magnesium at different quenching temperatures were studied. The results showed that the liquid–solid transition temperature range of AE42 alloy was from 630[Formula: see text]C to 590[Formula: see text]C. Precipitation of two kinds of rare earth compounds during solidification had been found. One was Al2RE phase at 616[Formula: see text]C. The other was Al[Formula: see text]RE3 phase at 604[Formula: see text]C. The solidification path of AE42 alloy was L [Formula: see text] [Formula: see text]-Mg [Formula: see text] [Formula: see text]-Mg+Al2RE [Formula: see text] Al2RE+[Formula: see text]-Mg+Al[Formula: see text]RE3.
Key Success Factors Positively Affecting Organizational Performance of Academic Spin-Offs
Authors: Poponi Stefano , Braccini Alessio Maria , Ruggieri Alessandro 
Published: April 2017

Universities create academic spin-offs (ASOs) as a strategy to market innovations produced through research. By their nature, ASOs are exposed to risky endeavors and often fail in achieving an adequate level of performance. In this paper, we focus on performance generation in ASOS. By way of a literature review, we contribute with the identification of nine factors associated with positive performance in ASOS: championed start-up, heterogeneity of founders’ skills, access to funding, environmental wealth, networking capital, relative size, trustworthiness, innovativeness and motivation for venturing. The paper describes and discusses the performance factors and suggests implications for research to further study performance in ASOS.
Syncope and Its Impact on Occupational Accidents and Employment
Authors: Numé Anna-Karin , Kragholm Kristian , Carlson Nicolas , Kristensen Søren L. , Bøggild Henrik , Hlatky Mark A. , Torp-Pedersen Christian , Gislason Gunnar , Ruwald Martin H. 
Published: April 2017

Background—
First-time syncopal episodes usually occur in adults of working age, but their impact on occupational safety and employment remains unknown. We examined the associations of syncope with occupational accidents and termination of employment.

Methods and Results—
Through linkage of Danish population-based registers, we included all residents 18 to 64 years from 2008 to 2012. Among 3 410 148 eligible individuals, 21 729 with a first-time diagnosis of syncope were identified, with a median age 48.4 years (first to third quartiles, 33.0–59.5), and 10 757 (49.5%) employed at time of the syncope event. Over a median follow-up of 3.2 years (first to third quartiles, 2.0–4.5), 622 people with syncope had an occupational accident requiring hospitalization (2.1/100 person-years). In multiple Poisson regression analysis, the incidence rate ratio in the employed syncope population was higher than in the employed general population (1.44; 95% confidence interval [CI], 1.33–1.55) and more pronounced in people with recurrences (2.02; 95% CI, 1.47–2.78). The 2-year risk of termination of employment was 31.3% (95% CI, 30.4%–32.3%), which was twice the risk of the reference population (15.2%; 95% CI, 14.7%–15.7%), using the Aalen–Johansen estimator. Factors associated with termination of employment were age <40 years (incidence rate ratio, 1.48; 95% CI, 1.37–1.59), cardiovascular disease (1.20; 95% CI, 1.06–1.36), depression (1.72; 95% CI, 1.55–1.90), and low educational level (2.61; 95% CI, 2.34–2.91).

Conclusions—
In this nationwide cohort, syncope was associated with a 1.4-fold higher risk of occupational accidents and a 2-fold higher risk of termination of employment compared with the employed general population.
Incidence and Risk Factors of Venous Thromboembolism After Orthopaedic Foot and Ankle Surgery
Authors: Ahmad Jamal , Lynch Mary-Katherine , Maltenfort Mitchell 
Published: April 2017

Background. This study examines the incidence and risk of postoperative symptomatic venous thromboembolism (VTE) after orthopaedic foot/ankle surgery. Materials. Patients that received foot/ankle surgery between 2006 and 2016 were reviewed. Inclusion criteria were surgical patients that were without coagulopathy, previous VTE, and/or using anticoagulation medications including aspirin. Age, sex, body mass index, medical comorbidities, and surgical diagnosis and procedure(s) were noted. Records were reviewed to see who developed a symptomatic VTE within 90 days from surgery. Results. This study involved 2774 patients that received foot/ankle surgery between 2006 and 2016. Of them, 22 (0.79%) developed a VTE within 90 days from surgery. The mean age of these patients was 49.5 years. Twelve patients were male and 10 were female. Sixteen patients were obese and 6 were nonobese. Postoperative VTEs were 14 infrapopliteal deep vein thrombosis (DVT), 1 suprapopliteal DVT, and 7 pulmonary emboli. The most common surgeries involved were ankle fracture repair in 8 (0.29%), Achilles tendon repair in 2 (0.07%), ankle ligament reconstruction in 2, and hammer-toe correction in 2 patients. Obesity was predictive of a postoperative VTE to a statistically significant degree (P = .04). Age, sex, medical comorbidities, diagnosis, and type of surgery were not significantly prognostic for a postsurgical VTE (P ≥ .05). Discussion. The incidence of VTE after foot/ankle surgery is low. However, obese patients are at significantly higher risk for VTE after such procedures. Clinical Relevance. These findings are important when educating patients as to their risks of developing a VTE after orthopaedic foot/ankle surgery. Levels of Evidence: Level III: Retrospective cohort study
Impact of social media usage on daytime sleepiness: A study in a sample of tertiary students in Singapore
Authors: Nasirudeen A M A , Lee Chin Adeline Lau , Wat Neo Josephine Koh , Lay Seng Lim , Wenjie Li 
Published: April 2017

Objective Many tertiary students access social networking sites on a daily basis. With the increased usage of smartphones, accessing social networking sites while commuting, in schools, waiting for friends, television commercial breaks has become prevalent among tertiary students. What started as a lifestyle choice has now become a daily necessity. Such behavior among tertiary students raises an important question for educators: how does social media usage affect tertiary students’ sleep patterns and daytime sleepiness, their attention difficulties, especially in school? Thus, the aim of this study was to examine the relationships between tertiary students' self-reports of social media usage and daytime sleepiness. Design The design was a cross-sectional, quantitative research study. Methods We used a survey that contained questions concerning demographic data, daytime sleepiness, total sleep time and social media usage and a version of the Cleveland Adolescent Sleepiness Questionnaire, modified for use in tertiary students, were used for data collection ( n = 969). Results The most preferred tool for accessing social networking sites was smartphones and WhatsApp was the most accessed site. Results indicated that nocturnal technology use has a weak, negative impact on tertiary students’ quantity of sleep that may lead to daytime sleepiness. Local Singapore students spent significantly more time on social networking sites at night compared to foreign students. As a result, local students experienced more daytime sleepiness compared to foreign students. Conclusions Prolonged social media usage, especially in bed, has a negative impact on tertiary students’ daytime sleepiness. Since the technology is such an integral part of most tertiary students’ lives, it is important to understand the impact it has on their sleep and daytime sleepiness.
Brachial Plexopathy After Cervical Spine Surgery
Authors: Than Khoi D. , Mummaneni Praveen V. , Smith Zachary A. , Hsu Wellington K. , Arnold Paul M. , Fehlings Michael G. , Mroz Thomas E. , Riew K. Daniel 
Published: April 2017

Study Design: Retrospective, multicenter case-series study and literature review. Objectives: To determine the prevalence of brachial plexopathy after cervical spine surgery and to review the literature to better understand the etiology and risk factors of brachial plexopathy after cervical spine surgery. Methods: A retrospective case-series study of 12 903 patients at 21 different sites was performed to analyze the prevalence of several different complications, including brachial plexopathy. A literature review of the US National Library of Medicine and the National Institutes of Health (PubMed) database was conducted to identify articles pertaining to brachial plexopathy following cervical spine surgery. Results: In our total population of 12 903 patients, only 1 suffered from postoperative brachial plexopathy. The overall prevalence rate was thus 0.01%, but the prevalence rate at the site where this complication occurred was 0.07%. Previously reported risk factors for postoperative brachial plexopathy include age, anterior surgical procedures, and a diagnosis of ossification of the posterior longitudinal ligament. The condition can also be due to patient positioning during surgery, which can generally be detected via the use of intraoperative neuromonitoring. Conclusions: Brachial plexopathy following cervical spine surgery is rare and merits further study.
Hypoglossal Nerve Palsy After Cervical Spine Surgery
Authors: Ames Christopher P. , Clark Aaron J. , Kanter Adam S. , Arnold Paul M. , Fehlings Michael G. , Mroz Thomas E. , Riew K. Daniel 
Published: April 2017

Study Design: Multi-institutional retrospective study. Objective: The goal of the current study is to quantify the incidence of 2 extremely rare complications of cervical spine surgery; hypoglossal and glossopharyngeal nerve palsies. Methods: A total of 8887 patients who underwent cervical spine surgery from 2005 to 2011 were included in the study from 21 institutions. Results: No glossopharyngeal nerve injuries were reported. One hypoglossal nerve injury was reported after a C3-7 laminectomy (0.01%). This deficit resolved with conservative management. The rate by institution ranged from 0% to 1.28%. Although not directly injured by the surgical procedure, the transient nerve injury might have been related to patient positioning as has been described previously in the literature. Conclusions: Hypoglossal nerve injury during cervical spine surgery is an extremely rare complication. Institutional rates may vary. Care should be taken during posterior cervical surgery to avoid hyperflexion of the neck and endotracheal tube malposition.
Recurrent Laryngeal Nerve Palsy After Cervical Spine Surgery: A Multicenter AOSpine Clinical Research Network Study
Authors: Gokaslan Ziya L. , Bydon Mohamad , De la Garza-Ramos Rafael , Smith Zachary A. , Hsu Wellington K. , Qureshi Sheeraz A. , Cho Samuel K. , Baird Evan O. , Mroz Thomas E. , Fehlings Michael , Arnold Paul M. , Riew K. Daniel 
Published: April 2017

Study Design: Multicenter retrospective study. Objectives: To investigate the risk of symptomatic recurrent laryngeal nerve palsy (RLNP) following cervical spine surgery, to examine risk factors for its development, and to report its treatment and outcomes. Methods: A multicenter study from 21 high-volume surgical centers from the AOSpine North America Clinical Research Network was performed. Each center screened for rare complications following cervical spine surgery, including RLNP. Patients were included if they underwent cervical spine surgery (levels from C2 to C7) between January 1, 2005 and December 31, 2011. Data were analyzed with regard to complication treatment and outcome. Cases were compared to a control group from the AOSpine CSM and CSM-I studies. Results: Three centers reported 19 cases of RLNP from a cohort of 1345 patients. The reported incidence of RLNP ranged from 0.6% to 2.9% between these 3 centers. Fifteen patients (79%) in the RLNP group were approached from the left side. Ten patients (52.6%) required treatment for RLNP—6 required medical therapy (steroids), 1 interventional treatment (injection laryngoplasty), and 3 conservative therapy (speech therapy). When examining outcomes, 73.7% (14/19) of cases resolved completely, 15.8% (3/19) resolved with residual effects, and in 10.5% (2/19) of cases this could not be determined. Conclusions: In this multicenter study examining rare complications following cervical spine surgery, the risk of RLNP after cervical spine surgery ranged from 0.6% to 2.9% between centers. Though rare, it was found that 16% of patients may experience partial resolution with residual effects, and 74% resolve completely.
Rare Complications of Cervical Spine Surgery: Horner’s Syndrome
Authors: Traynelis Vincent C. , Malone Hani R. , Smith Zachary A. , Hsu Wellington K. , Kanter Adam S. , Qureshi Sheeraz A. , Cho Samuel K. , Baird Evan O. , Isaacs Robert E. , Rahman Ra’Kerry K. , Polevaya Galina , Smith Justin S. , Shaffrey Christopher , Tortolani P. Justin , Stroh D. Alex , Arnold Paul M. , Fehlings Michael G. , Mroz Thomas E. , Riew K. Daniel 
Published: April 2017

Study Design: A multicenter retrospective case series. Objective: Horner’s syndrome is a known complication of anterior cervical spinal surgery, but it is rarely encountered in clinical practice. To better understand the incidence, risks, and neurologic outcomes associated with Horner’s syndrome, a multicenter study was performed to review a large collective experience with this rare complication. Methods: We conducted a retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network. Medical records for 17 625 patients who received subaxial cervical spine surgery from 2005 to 2011 were reviewed to identify occurrence of 21 predefined treatment complications. Descriptive statistics were provided for baseline patient characteristics. Paired t test was used to analyze changes in clinical outcomes at follow-up compared to preoperative status. Results: In total, 8887 patients who underwent anterior cervical spine surgery at the participating institutions were screened. Postoperative Horner’s syndrome was identified in 5 (0.06%) patients. All patients experienced the complication following anterior cervical discectomy and fusion. The sympathetic trunk appeared to be more vulnerable when operating on midcervical levels (C5, C6), and most patients experienced at least a partial recovery without further treatment. Conclusions: This collective experience suggests that Horner’s syndrome is an exceedingly rare complication following anterior cervical spine surgery. Injury to the sympathetic trunk may be limited by maintaining a midline surgical trajectory when possible, and performing careful dissection and retraction of the longus colli muscle when lateral exposure is necessary, especially at caudal cervical levels.
Nutrition and metabolism in burn patients
Authors: Clark Audra , Imran Jonathan , Madni Tarik , Wolf Steven E. 
Published: April 2017

AbstractSevere burn causes significant metabolic derangements that make nutritional support uniquely important and challenging for burned patients. Burn injury causes a persistent and prolonged hypermetabolic state and increased catabolism that results in increased muscle wasting and cachexia. Metabolic rates of burn patients can surpass twice normal, and failure to fulfill these energy requirements causes impaired wound healing, organ dysfunction, and susceptibility to infection. Adequate assessment and provision of nutritional needs is imperative to care for these patients. There is no consensus regarding the optimal timing, route, amount, and composition of nutritional support for burn patients, but most clinicians advocate for early enteral nutrition with high-carbohydrate formulas.Nutritional support must be individualized, monitored, and adjusted throughout recovery. Further investigation is needed regarding optimal nutritional support and accurate nutritional endpoints and goals.