bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rugby headgear and concussion prevention: misconceptions could increase aggressive play
Authors: Menger Richard , Menger Austin , Nanda Anil 
Published: April 2016

OBJECTIVE
Multiple studies have illustrated that rugby headgear offers no statistically significant protection against concussions. However, there remains concern that many players believe rugby headgear in fact does prevent concussions. Further investigation was undertaken to illustrate that misconceptions about concussion prevention and rugby headgear may lead to an increase in aggressive play.

METHODS
Data were constructed by Internet survey solicitation among United States collegiate rugby players across 19 teams. Initial information given was related to club, age, experience, use of headgear, playing time, whether the rugger played football or wrestling in high school, and whether the player believed headgear prevented concussion. Data were then constructed as to whether wearing headgear would increase aggressive playing style secondary to a false sense of protection.

RESULTS
A total of 122 players responded. All players were male. The average player was 19.5 years old and had 2.7 years of experience. Twenty-three of 122 players (18.9%) wore protective headgear; 55.4% of players listed forward as their primary position. Overall, 45.8% (55/120) of players played 70–80 minutes per game, 44.6% (54/121) played football or wrestled in high school, 38.1% (45/118) believed headgear prevented concussions, and 42.2% (51/121) stated that if they were using headgear they would be more aggressive with their play in terms of running or tackling. Regression analysis illustrated that those who believed headgear prevented concussions were or would be more likely to engage in aggressive play (p = 0.001).

CONCLUSIONS
Nearly 40% of collegiate rugby players surveyed believed headgear helped to prevent concussions despite no scientific evidence that it does. This misconception about rugby headgear could increase aggressive play. Those who believed headgear prevented concussion were, on average, 4 times more likely to play with increased aggressive form than those who believed headgear did not prevent concussions (p = 0.001). This can place all players at increased risk without providing additional protection. Further investigation is warranted to determine if headgear increases the actual measured incidence of concussion among rugby players in the United States.
Interhemispheric connectivity revealed by diffusion tensor imaging fiber tracking derived from navigated transcranial magnetic stimulation maps as a sign of language function at risk in patients with brain tumors
Authors: Sollmann Nico , Negwer Chiara , Tussis Lorena , Hauck Theresa , Ille Sebastian , Maurer Stefanie , Giglhuber Katrin , Bauer Jan S. , Ringel Florian , Meyer Bernhard , Krieg Sandro M. 
Published: April 2016

OBJECTIVE
Resection of brain tumors in language-eloquent areas entails the risk of postoperative aphasia. It has been demonstrated via navigated transcranial magnetic stimulation (nTMS) that language function can partially shift to the unaffected hemisphere due to tumor-induced plasticity. Therefore, this study was designed to evaluate whether interhemispheric connectivity (IC) detected by nTMS-based diffusion tensor imaging–fiber tracking (DTI-FT) can be used to predict surgery-related aphasia in patients with brain tumors.

METHODS
Thirty-eight patients with left-sided perisylvian brain lesions underwent cortical language mapping of both hemispheres by nTMS prior to awake surgery. Then, nTMS-based DTI-FT was conducted with a fractional anisotropy (FA) of 0.01 and 0.2 to visualize nTMS-based IC. Receiver operating characteristics were calculated for the prediction of a postoperative (irrespective of the preoperative state) and a new surgery-related aphasia by the presence of detectable IC.

RESULTS
Language mapping by nTMS was possible in all patients. Seventeen patients (44.7%) suffered from surgery-related worsening of language performance (transient aphasia according to 3-month follow-up in 16 subjects [42.1%]; new permanent aphasia according to 3-month follow-up in 1 patient [2.6%]). Regarding the correlation of aphasia to nTMS-based IC, statistically significant differences were revealed for both evaluated FA values. However, better results were observed for tractography with an FA of 0.2, which led to a specificity of 93% (postoperative aphasia) and 90% (surgery-related aphasia). For postoperative aphasia, the corresponding OR was 0.1282 (95% CI 0.0143–1.1520), and for surgery-related aphasia the OR was 0.1184 (95% CI 0.0208–0.6754).

CONCLUSIONS
According to these results, IC detected by preoperative nTMS-based DTI-FT might be regarded as a risk factor for surgery-related aphasia, with a specificity of up to 93%. However, because the majority of enrolled patients suffered from transient aphasia postoperatively, it has to be evaluated whether this approach distinctly leads to similar results among patients with permanent language deficits. Despite this restriction, this approach might contribute to individualized patient consultation prior to tumor resection in clinical practice.
Prediction of outcome after subarachnoid hemorrhage: timing of clinical assessment
Authors: van Donkelaar Carlina E. , Bakker Nicolaas A. , Veeger Nic J. G. M. , Uyttenboogaart Maarten , Metzemaekers Jan D. M. , Eshghi Omid , Mazuri Aryan , Foumani Mahrouz , Luijckx Gert-Jan , Groen Rob J. M. , van Dijk J. Marc C. 
Published: April 2016

OBJECTIVE
Currently, early prediction of outcome after spontaneous subarachnoid hemorrhage (SAH) lacks accuracy despite multiple studies addressing this issue. The clinical condition of the patient on admission as assessed using the World Federation of Neurosurgical Societies (WFNS) grading scale is currently considered the gold standard. However, the timing of the clinical assessment is subject to debate, as is the contribution of additional predictors. The aim of this study was to identify either the conventional WFNS grade on admission or the WFNS grade after neurological resuscitation (rWFNS) as the most accurate predictor of outcome after SAH.

METHODS
This prospective observational cohort study included 1620 consecutive patients with SAH admitted between January 1998 and December 2014 at our university neurovascular center. The primary outcome measure was a poor modified Rankin Scale score at the 2-month follow-up. Clinical predictors were identified using multivariate logistic regression analyses. Area under the receiver operating characteristic curve (AUC) analysis was used to test discriminative performance of the final model. An AUC of > 0.8 was regarded as indicative of a model with good prognostic value.

RESULTS
Poor outcome (modified Rankin Scale Score 4–6) was observed in 25% of the patients. The rWFNS grade was a significantly stronger predictor of outcome than the admission WFNS grade. The rWFNS grade was significantly associated with poor outcome (p < 0.001) as well as increasing age (p < 0.001), higher modified Fisher grade (p < 0.001), larger aneurysm size (p < 0.001), and the presence of an intracerebral hematoma (OR 1.8, 95% CI 1.2–2.8; p = 0.002). The final model had an AUC of 0.87 (95% CI 0.85–0.89), which indicates excellent prognostic value regarding the discrimination between poor and good outcome after SAH.

CONCLUSIONS
In clinical practice and future research, neurological assessment and grading of patients should be performed using the rWFNS to obtain the best representation of their clinical condition.
Impact of Glasgow Coma Scale score and pupil parameters on mortality rate and outcome in pediatric and adult severe traumatic brain injury: a retrospective, multicenter cohort study
Authors: Emami Pedram , Czorlich Patrick , Fritzsche Friederike S. , Westphal Manfred , Rueger Johannes M. , Lefering Rolf , Hoffmann Michael 
Published: April 2016

OBJECTIVE
Prediction of death and functional outcome is essential for determining treatment strategies and allocation of resources for patients with severe traumatic brain injury (TBI). The aim of this study was to evaluate, by using pupillary status and Glasgow Coma Scale (GCS) score, if patients with severe TBI who are ≤ 15 years old have a lower mortality rate and better outcome than adults with severe TBI.

METHODS
A retrospective cohort analysis of patients suffering from severe TBI registered in the Trauma Registry of the German Society for Trauma Surgery between 2002 and 2013 was undertaken. Severe TBI was defined as an Abbreviated Injury Scale of the head (AIShead) score of ≥ 3 and an AIS score for any other part of the body that does not exceed the AIShead score. Only patients with complete data (GCS score, age, and pupil parameters) were included. To assess the impact of GCS score and pupil parameters, the authors also used the recently introduced Eppendorf-Cologne Scale and divided the study population into 2 groups: children (0–15 years old) and adults (16–55 years old). Each patient's outcome was measured at discharge from the trauma center by using the Glasgow Outcome Scale.

RESULTS
A total of 9959 patients fulfilled the study inclusion criteria; 888 (8.9%) patients were ≤ 15 years old (median 10 years). The overall mortality rate and the mortality rate for patients with a GCS of 3 and bilaterally fixed and dilated pupils (19.9% and 16.3%, respectively) were higher for the adults than for the pediatric patients (85% vs 80.9%, respectively), although cardiopulmonary resuscitation rates were significantly higher in the pediatric patients (5.6% vs 8.8%, respectively). In the multivariate logistic regression analysis, no motor response (OR 3.490, 95% CI 2.240–5.435) and fixed pupils (OR 4.197, 95% CI 3.271–5.386) and bilateral dilated pupils (OR 2.848, 95% CI 2.282–3.556) were associated with a higher mortality rate. Patients ≤ 15 years old had a statistically lower mortality rate (OR 0.536, 95% CI 0.421–0.814; p = 0.001). The rate of good functional outcomes (Glasgow Outcome Scale Score 4 or 5) was higher in pediatric patients than in the adults (72.2% vs 63.1%, respectively).

CONCLUSIONS
This study found that severe TBI in children aged ≤ 15 years is associated with a lower mortality rate and superior functional outcome than in adults. Also, children admitted with a missing motor response or fixed and bilaterally dilated pupils also have a lower mortality rate and higher functional outcome than adults with the same initial presentation. Therefore, patients suffering from severe TBI, especially pediatric patients, could benefit from early and aggressive treatment.
Childhood hydrocephalus secondary to posterior fossa tumor is both an intra- and extraaxial process
Authors: Bateman Grant A. , Fiorentino Mark 
Published: April 2016

OBJECTIVE
Ventricular dilation secondary to tumor obstruction of the posterior fossa CSF outflow in childhood is an intraaxial process. However, third ventriculostomy or complete tumor removal often fails to reduce the pressure in some children, and in others there is a delayed reduction in intracranial pressure; this is termed the adaptation period. The cause of this adaptation period has not been studied. Venous sinus compression is highly correlated with other forms of childhood hydrocephalus, and this study seeks to follow the changes that occur in sinus cross-sectional area after surgery.

METHODS
Twelve children with posterior fossa tumors underwent MRI examination that included standard T2-weighted and 3D contrast-enhanced images obtained preoperatively, in the immediate postoperative period, and after several months. The volumes of the lateral and third ventricles and the minimum cross-sectional area of the transverse and sigmoid sinuses were measured. Patients were categorized by 1) shunt status (those who required a shunt vs those who did not) and 2) by age (those younger than 3 years vs those older than 3 years at diagnosis).

RESULTS
There was a significant reduction in ventricular volume in both the immediate and secondary follow-up periods for all patients. There was preoperative venous sinus compression in all groups, which did not change significantly in the immediate postoperative period but did improve in the secondary follow-up period. The younger children had larger ventricles and smaller sinuses before surgery compared with the older children.

CONCLUSIONS
In children with obstructed hydrocephalus caused by tumor, there is secondary compression of venous outflow, indicating both an intra- and extraaxial process. The expansion of the sinuses following decompression of the posterior fossa is delayed and may correlate with the adaptation period. Younger children have greater sinus compression than older ones.
Toward a better understanding of the cellular basis for cerebrospinal fluid shunt obstruction: report on the construction of a bank of explanted hydrocephalus devices
Authors: Hanak Brian W. , Ross Emily F. , Harris Carolyn A. , Browd Samuel R. , Shain William 
Published: April 2016

OBJECTIVE
Shunt obstruction by cells and/or tissue is the most common cause of shunt failure. Ventricular catheter obstruction alone accounts for more than 50% of shunt failures in pediatric patients. The authors sought to systematically collect explanted ventricular catheters from the Seattle Children's Hospital with a focus on elucidating the cellular mechanisms underlying obstruction.

METHODS
In the operating room, explanted hardware was placed in 4% paraformaldehyde. Weekly, samples were transferred to buffer solution and stored at 4°C. After consent was obtained for their use, catheters were labeled using cell-specific markers for astrocytes (glial fibrillary acidic protein), microglia (ionized calcium-binding adapter molecule 1), and choroid plexus (transthyretin) in conjunction with a nuclear stain (Hoechst). Catheters were mounted in custom polycarbonate imaging chambers. Three-dimensional, multispectral, spinning-disk confocal microscopy was used to image catheter cerebrospinal fluid–intake holes (10× objective, 499.2-μm-thick z-stack, 2.4-μm step size, Olympus IX81 inverted microscope with motorized stage and charge-coupled device camera). Values are reported as the mean ± standard error of the mean and were compared using a 2-tailed Mann-Whitney U-test. Significance was defined at p < 0.05.

RESULTS
Thirty-six ventricular catheters have been imaged to date, resulting in the following observations: 1) Astrocytes and microglia are the dominant cell types bound directly to catheter surfaces; 2) cellular binding to catheters is ubiquitous even if no grossly visible tissue is apparent; and 3) immunohistochemical techniques are of limited utility when a catheter has been exposed to Bugbee wire electrocautery. Statistical analysis of 24 catheters was performed, after excluding 7 catheters exposed to Bugbee wire cautery, 3 that were poorly fixed, and 2 that demonstrated pronounced autofluorescence. This analysis revealed that catheters with a microglia-dominant cellular response tended to be implanted for shorter durations (24.7 ± 6.7 days) than those with an astrocyte-dominant response (1183 ± 642 days; p = 0.027).

CONCLUSIONS
Ventricular catheter occlusion remains a significant source of shunt morbidity in the pediatric population, and given their ability to intimately associate with catheter surfaces, astrocytes and microglia appear to be critical to this pathophysiology. Microglia tend to be the dominant cell type on catheters implanted for less than 2 months, while astrocytes tend to be the most prevalent cell type on catheters implanted for longer time courses and are noted to serve as an interface for the secondary attachment of ependymal cells and choroid plexus.
The cobra's tongue: Rethinking the function of the “fishtail appendage” on the pitcher plant Darlingtonia californica
Authors: Armitage David W. 
Published: April 2016

PREMISE OF STUDY:Carnivorous pitcher plants employ a variety of putative adaptations for prey attraction and capture. One example is the peculiar forked “fishtail appendage”, a foliar structure widely presumed to function as a prey attractant on adult leaves of Darlingtonia californica (Sarraceniaceae). This study tests the prediction that the presence of the appendage facilitates prey capture and can be considered an example of an adaptation to the carnivorous syndrome.METHODS:In a field experiment following a cohort of Darlingtonia leaves over their growing season, before the pitcher traps opened, the fishtail appendages from half of the leaves were removed. Additionally, all appendages were removed from every plant at two small, isolated populations. After 54 and 104 d, prey items were collected to determine whether differences in prey composition and biomass existed between experimental and unmanipulated control leaves.KEY RESULTS:Removal of the fishtail appendage did not reduce pitcher leaves' prey biomass nor alter their prey composition at either the level of individual leaves or entire populations. Fishtail appendages on plants growing in shaded habitats contained significantly greater chlorophyll concentrations than those on plants growing in full sun.CONCLUSIONS:These results call into question the longstanding assumption that the fishtail appendage on Darlingtonia is an adaptation critical for the attraction and capture of prey. I suggest alternative evolutionary explanations for the role of the fishtail structure and repropose a hypothesis on the mutualistic nature of pitcher plant–arthropod trophic interactions.
THE EATING HABITS OF MILKY WAY-MASS HALOS: DESTROYED DWARF SATELLITES AND THE METALLICITY DISTRIBUTION OF ACCRETED STARS
Authors: Deason Alis J. , Mao Yao-Yuan , Wechsler Risa H. 
Published: April 2016

ABSTRACT
We study the mass spectrum of destroyed dwarfs that contribute to the accreted stellar mass of Milky Way (MW)-mass (M
vir ∼ 1012.1
M
⊙) halos using a suite of 45 zoom-in dissipationless simulations. Empirical models are employed to relate (peak) subhalo mass to dwarf stellar mass, and we use constraints from z = 0 observations and hydrodynamical simulations to estimate the metallicity distribution of the accreted stellar material. The dominant contributors to the accreted stellar mass are relatively massive dwarfs with M
star ∼ 108–1010
M
⊙. Halos with more quiescent accretion histories tend to have lower mass progenitors (108–109
M
⊙), and lower overall accreted stellar masses. Ultra-faint mass (M
star < 105
M
⊙) dwarfs contribute a negligible amount (≪1%) to the accreted stellar mass and, despite having low average metallicities, supply a small fraction (∼2%–5%) of the very metal-poor stars with [Fe/H] < −2. Dwarfs with masses 105 < M
star/M
⊙ < 108 provide a substantial amount of the very metal-poor stellar material (∼40%–80%), and even relatively metal-rich dwarfs with M
star > 108
M
⊙ can contribute a considerable fraction (∼20%–60%) of metal-poor stars if their metallicity distributions have significant metal-poor tails. Finally, we find that the generic assumption of a quiescent assembly history for the MW halo seems to be in tension with the mass spectrum of its surviving dwarfs. We suggest that the MW could be a “transient fossil”; a quiescent halo with a recent accretion event(s) that disguises the preceding formation history of the halo.
STARBURST-DRIVEN GALACTIC SUPERBUBBLES RADIATING TO 10 K
Authors: Tanner Ryan , Cecil Gerald , Heitsch Fabian 
Published: April 2016

ABSTRACT
Our three-dimensional hydrodynamical simulations of starbursts examine the formation of superbubbles over a range of driving luminosities and mass loadings that determine superbubble growth and wind velocity. From this we determine the relationship between the velocity of a galactic wind (GW) and the power of the starburst. We find a threshold for the formation of a wind, above which the speed of the wind is not affected by grid resolution or the temperature floor of our radiative cooling. We investigate the effect that two different temperature floors in our radiative cooling prescription have on wind kinematics and content. We find that cooling to 10 K instead of to 104 K increases the mass fraction of cold neutral and hot X-ray gas in the GW, while halving that in warm Hα. Our simulations show that the mass of cold gas transported into the lower halo does not depend on the starburst strength. Optically bright filaments form at the edge of merging superbubbles, or where a cold dense cloud has been disrupted by the wind. Filaments formed by merging superbubbles will persist and grow to

>
400

pc in length if anchored to a star forming complex. Filaments embedded in the hot GW contain warm and cold gas that moves 300−1200 km s−1 slower than the surrounding wind, with the coldest gas hardly moving with respect to the Galaxy. Warm and cold matter in the GW show asymmetric absorption profiles consistent with observations, with a thin tail up to the wind velocity.
SPECTROSCOPIC BINARIES IN THE ORION NEBULA CLUSTER AND NGC 2264
Authors: Kounkel Marina , Hartmann Lee , Tobin John J. , Mateo Mario , Bailey John I. , Spencer Meghin 
Published: April 2016

ABSTRACT
We examine the spectroscopic binary population for two massive nearby regions of clustered star formation, the Orion Nebula Cluster (ONC) and NGC 2264, supplementing the data presented by Tobin et al. with more recent observations and more extensive analysis. The inferred multiplicity fraction up to 10 au based on these observations is 5.3 ± 1.2% for NGC 2264 and 5.8 ± 1.1% for the ONC; these values are consistent with the distribution of binaries in the field in the relevant parameter range. Eight of the multiple systems in the sample have enough epochs to perform an initial fit for the orbital parameters. Two of these sources are double-lined spectroscopic binaries; for them, we determine the mass ratio. Our reanalysis of the distribution of stellar radial velocities toward these clusters presents a significantly better agreement between stellar and gas kinematics than was previously thought.