bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neurophobia Inception: A Study of Trainees' Perceptions of Neurology Education
Authors: Fantaneanu Tadeu A. , Moreau Katherine , Eady Kaylee , Clarkin Chantalle , DeMeulemeester Christine , Maclean Heather , Doja Asif 
Published: December 2014

Objectives:We wanted to examine the extent to which “neurophobia” exists among medical students and determine if students’ perceptions of neurology differ by year of study while exploring the factors that contribute to the development of “neurophobia”.Methods:We used a two-phase, sequential, mixed-methods explanatory design in this single centre study. Phase 1 involved the collection and analysis of a questionnaire administered to students in the first three years of medical school. Phase 2 involved focus groups of a subgroup of students who demonstrated evidence of neurophobia in Phase 1.Results:In total, 187 (39 %) undergraduate medical trainees responded to the questionnaire (response rates of 37%, 44% and 19% for first-, second- and third-year students, respectively). 24% of respondents indicated that they were afraid of clinical neurology and 32% were afraid of the academic neurosciences. Additionally, 46% of respondents thought that clinical neurology is one of the most difficult disciplines in medicine. Phase 2 findings revealed that many students reported negative preconceptions about neurology and commented on neurology’s difficulty. Some experienced changes in these conceptions following their neurology block. Past clinical, educational, and personal experiences in neurology impacted their comfort level.Conclusions:This study shows that the level of comfort towards clinical neurology increases following students’ participation in second-year neurology blocks, but that third-year students continue to show signs of neurophobia with lower comfort levels. It provides insight into why neurophobia exists amongst medical students and sheds light on pre-existing and emerging factors contributing to this sense of neurophobia.
A Unique Model for ONSD Part II: Inter/Intra-operator Variability
Authors: Zeiler F.A. , Unger B. , Zhu Q. , Xiao J. , Kirkpatrick A.W. , Kramer A.H. , Aleassa E.M. , Gillman L.M. 
Published: December 2014

Objective:To evauluate our novel ultrasound model for measurement of optic nerve sheath diameter (ONSD) and determine the intra- and inter-operator variability associated with this technique.Methods:We conducted ten measurements of ONSD per model amongst eight different models with a single experienced operator to examine intra-operator variability. Similarly, we had seven different operators measure the OSND twice in eight different models, in order to determine inter-operator variability analyzed with a three level linear statistical model.Results:For intra-operator variability, the intra-cluster correlation coefficients for the experienced and novice operators were 0.643 and 0.453 respectively. This displayed improvement in intra-operator variability with experience. The inter-cluster correlation coefficient was 0 for the group of novice operators, indicating negligible difference amongst multiple operators in measuring any given model of ONSD. A strong, statistically significant, linear relationship between the actual model disc size and the ultrasound ONSD measures was identified, implying the reliability of the images produced by our novel model.Conclusions:Utilizing a novel model for ONSD ultrasonography, we have determined the intraoperator reliability of ONSD measurement to be moderate, with no appreciable difference amongst multiple operators. Improvement in measurement reliability has been demonstrated between expert and novice operators with our model, indicating the potential benefit of simulation platforms for teaching the technique of ONSD ultrasound.
Hospitalized Head and Spine Injuries on Saskatchewan Farms
Authors: Paton Gillian R. , Hagel Louise , Fourney Daryl R. 
Published: December 2014

Introduction:With over 44,000 individual farms, farm dwellers account for 11% of the population of Saskatchewan. There is limited data on brain and spine injuries acquired on farms. The objective of this study was to evaluate the epidemiology of head and spine injuries on Saskatchewan farms to assist the development of injury prevention initiatives.Methods:Using the Canadian Centre for Agricultural Health and Safety's Saskatchewan Farm Injury Surveillance Database, farm-related head and spine injuries hospitalized > 24 hours were examined (1990-2007). We collected information regarding the type and mechanism of injury as well as the geographic location of both the injury and treatment.Results:The database captured 390 brain injuries and 228 spine injuries, including 16 spinal cord injuries. The majority of patients were male (73.3% of head injuries and 84.2% of spine injuries). The highest risk age groups were 50-59 years, with 24.1% of the spine injuries, and 40-49 years, with 19.2% of the head injuries. The most common causes of injury were falls and/or machinery-related. The average annual incidence of farm-related spine and head injury were 10.8 and 17.6 per 100,000 farm population, respectively. All patients included in this study were hospitalized for over 24 hours, with 44.7% of spine injuries spending over one week in hospital, and 20% of head injuries spending over three days in hospital.Conclusions:Injury prevention initiatives should be targeted towards males aged 40-59 years residing in the southern areas of the province, with increased awareness towards the dangers of falls and operating tractors.
Endoscopic Third Ventriculostomy for Hydrocephalus Due to Tectal Glioma
Authors: Diaz Roberto Jose , Girgis Fady M. , Hamiltonn Mark G. 
Published: December 2014

Background:Tectal gliomas commonly present with hydrocephalus from obstruction of the aqueduct of Sylvius. The creation of a ventriculostomy in the floor of the third ventricle (ETV) has been previously reported to by-pass aqueduct obstruction. The goal of this study was to determine the safety and efficacy of ETV in the presence of an obstructing tectal glioma.Methods:We retrospectively reviewed the clinical presentation, management, and clinical outcome after ETV in patients diagnosed with tectal glioma and obstructive hydrocephalus in our institution over a period of 15 years. Shunt freedom at follow-up was the main outcome variable. Long-term clinical outcome was assessed at the most recent clinic visit. Clinical outcome was ranked as excellent, good, or poor according to resolution of symptoms and patient functional status.Results:The median age at presentation was 16.5 years (range: 6.4 to 59 years) and the most common presenting symptom was headache. Eleven patients had ETV as a primary procedure and three patients underwent ETV as a substitute for shunt revision at the time of shunt failure. At follow-up (median 3.9 years, range: 2.2 to 7 years) 13 of 14 patients remain shunt independent with excellent (n=9) or good outcomes (n=5).Conclusions:In patients with tectal glioma causing obstructive hydrocephalus, ETV can be performed safely in the primary setting or as a substitute for shunt revision. A high rate of shunt freedom (78%-100%) at prolonged follow-up can be expected in this patient population.
Current Concepts in the Neuropathology and Pathogenesis of Multiple Sclerosis
Authors: Wayne Moore G.R. 
Published: December 2014

ABSTRACT:Multiple sclerosis (MS) has been classically regarded as an inflammatory demyelinating disease of the central nervous system. In recent years, the classification and pathogenesis of the disease have become controversial, particularly with respect to whether an individual patient demonstrates a single or multiple pathogenetic mechanisms in the establishment of the focal plaque of MS. It is also becoming increasingly apparent that there is a significant neurodegenerative component in the disease, involving not only plaques but the non-plaque parenchyma as well. Magnetic resonance imaging, together with histopathologic studies, will continue to shed light on the pathogenesis of these focal and diffuse abnormalities in MS.
A time-indexed reference standard of adverse drug reactions
Authors: Harpaz Rave , Odgers David , Gaskin Greg , DuMouchel William , Winnenburg Rainer , Bodenreider Olivier , Ripple Anna , Szarfman Ana , Sorbello Alfred , Horvitz Eric , White Ryen W. , Shah Nigam H. 
Published: December 2014

AbstractUndetected adverse drug reactions (ADRs) pose a major burden on the health system. Data mining methodologies designed to identify signals of novel ADRs are of deep importance for drug safety surveillance. The development and evaluation of these methodologies requires proper reference benchmarks. While progress has recently been made in developing such benchmarks, our understanding of the performance characteristics of the data mining methodologies is limited because existing benchmarks do not support prospective performance evaluations. We address this shortcoming by providing a reference standard to support prospective performance evaluations. The reference standard was systematically curated from drug labeling revisions, such as new warnings, which were issued and communicated by the US Food and Drug Administration in 2013. The reference standard includes 62 positive test cases and 75 negative controls, and covers 44 drugs and 38 events. We provide usage guidance and empirical support for the reference standard by applying it to analyze two data sources commonly mined for drug safety surveillance.
Lyot‐type flat‐top fibre multiwavelength filter based on polarisation‐diversity loop structure
Authors: Jo Songhyun , Park Kyoungsoo , Lee Yong Wook 
Published: December 2014

Proposed is a Lyot‐type flat‐top fibre multiwavelength filter based on a polarisation‐diversity loop structure, which has flat‐top and lossy flat‐top passbands and multiwavelength switching capability. The proposed filter is composed of a polarisation beam splitter, two half‐wave plates (HWPs) and two polarisation‐maintaining fibre (PMF) loops concatenated with a 60° offset between their principal axes. One of the two PMF loops is two times longer than the other. It is able to operate in a flat‐top or a lossy flat‐top band mode at the selected combination of the azimuthal orientation angles of two HWPs. In particular, through the adjustment of the orientation angles of the two HWPs, its multiwavelength channels can be interleaved in each mode, which cannot be realised in a previously reported Lyot‐Sagnac comb filter based on a fibre coupler. In addition to the channel interleaving capability, it provides narrower passbands compared with previous fibre multiwavelength filters with the same order. To make a quantitative comparison between the passband bandwidths of the proposed filter and other filters, both −1 and −3 dB passband bandwidths of a conventional zeroth‐order, a Solc‐type first‐order and the proposed multiwavelength filters were considered and compared with each other.
Electronic structure and aromaticity of large-scale hexagonal graphene nanoflakes
Authors: Hu Wei , Lin Lin , Yang Chao , Yang Jinlong 
Published: December 2014

With the help of the recently developed SIESTA-pole (Spanish Initiative for Electronic Simulations with Thousands of Atoms) - PEXSI (pole expansion and selected inversion) method [L. Lin, A. García, G. Huhs, and C. Yang, J. Phys.: Condens. Matter 26, 305503 (2014)], we perform Kohn-Sham density functional theory calculations to study the stability and electronic structure of hydrogen passivated hexagonal graphene nanoflakes (GNFs) with up to 11 700 atoms. We find the electronic properties of GNFs, including their cohesive energy, edge formation energy, highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap, edge states, and aromaticity, depend sensitively on the type of edges (armchair graphene nanoflakes (ACGNFs) and zigzag graphene nanoflakes (ZZGNFs)), size and the number of electrons. We observe that, due to the edge-induced strain effect in ACGNFs, large-scale ACGNFs’ edge formation energy decreases as their size increases. This trend does not hold for ZZGNFs due to the presence of many edge states in ZZGNFs. We find that the energy gaps Eg of GNFs all decay with respect to 1/L, where L is the size of the GNF, in a linear fashion. But as their size increases, ZZGNFs exhibit more localized edge states. We believe the presence of these states makes their gap decrease more rapidly. In particular, when L is larger than 6.40 nm, we find that ZZGNFs exhibit metallic characteristics. Furthermore, we find that the aromatic structures of GNFs appear to depend only on whether the system has 4N or 4N + 2 electrons, where N is an integer.
Human infrared vision is triggered by two-photon chromophore isomerization
Authors: Palczewska Grazyna , Vinberg Frans , Stremplewski Patrycjusz , Bircher Martin P. , Salom David , Komar Katarzyna , Zhang Jianye , Cascella Michele , Wojtkowski Maciej , Kefalov Vladimir J. , Palczewski Krzysztof 
Published: December 2014

Significance
This study resolves a long-standing question about the ability of humans to perceive near infrared radiation (IR) and identifies a mechanism driving human IR vision. A few previous reports and our expanded psychophysical studies here reveal that humans can detect IR at wavelengths longer than 1,000 nm and perceive it as visible light, a finding that has not received a satisfactory physical explanation. We show that IR light activates photoreceptors through a nonlinear optical process. IR light also caused photoisomerization of purified pigments and a model chromophore compound. These observations are consistent with our quantum mechanical model for the energetics of two-photon activation of rhodopsin. Thus, humans can perceive IR light via two-photon isomerization of visual pigment chromophores.
Multiple functional therapeutic effects of the estrogen receptor β agonist indazole-Cl in a mouse model of multiple sclerosis
Authors: Moore Spencer M. , Khalaj Anna J. , Kumar Shalini , Winchester Zachary , Yoon JaeHee , Yoo Timothy , Martinez-Torres Leonardo , Yasui Norio , Katzenellenbogen John A. , Tiwari-Woodruff Seema Kaushalya 
Published: December 2014

Significance
In the search for effective multiple sclerosis treatment, much effort has been invested in estrogens and estrogen receptor (ER) agonists because of their neuroprotective benefits. However, because estrogens can produce ERα-based feminizing effects and cancer, ERβ agonists represent more desirable therapeutic candidates. The structurally unique ERβ ligand indazole chloride (Ind-Cl), a halogen-substituted phenyl-2H-indazole core, is a preclinical development candidate with a strong dossier. Our results indicate that Ind-Cl is effective in functionally ameliorating disease even when treatment is initiated at peak experimental autoimmune encephalomyelitis clinical disease. Ind-Cl’s immunomodulatory and direct remyelinating effects result in motor dysfunction amelioration. These findings support Ind-Cl's potential to provide unique therapeutic benefits to patients with multiple sclerosis, as well as patients affected by other demyelinating disorders.
Evolutionary limits to cooperation in microbial communities
Authors: Oliveira Nuno M. , Niehus Rene , Foster Kevin R. 
Published: December 2014

Significance
Microbes form dense and diverse communities that affect every aspect of our lives. Microbial communities are often viewed as cooperative networks with species working together toward a common goal. Here, we critically evaluate this view using an ecoevolutionary model. We show that cooperating with other species can be a poor evolutionary strategy, because it renders a cell dependent on species that may not be nearby. Moreover, when cooperative exchanges do evolve, they are inefficient and reduce the productivity of the community. Evolution by natural selection then limits the potential for productive cooperation between microbial species. We argue that understanding these limits and how to overcome them will be key to engineering microbial communities for our own ends.
Power transduction of actin filaments ratcheting in vitro against a load
Authors: Démoulin Damien , Carlier Marie-France , Bibette Jérôme , Baudry Jean 
Published: December 2014

Significance
How the continuous polymerization of actin filaments pushes the cell membrane forward in migrating cells is an intriguing issue that has yet to be fully understood. Molecular mechanisms were proposed, but testing them experimentally is a challenge, due to hardly accessible length scales and to the influence of regulatory proteins constantly changing the mechanical properties of polymerizing filaments. We present an experimental setup designed to minimize the number of parameters influencing filament growth to focus on the mechanism of force generation. We demonstrate that it is consistent with the Brownian ratchet model. Furthermore, we define a criterion for cell migration efficiency and quantify the number of filaments that need to push the membrane to maximize this efficiency.
Antibody-driven design of a human cytomegalovirus gHgLpUL128L subunit vaccine that selectively elicits potent neutralizing antibodies
Authors: Kabanova Anna , Perez Laurent , Lilleri Daniele , Marcandalli Jessica , Agatic Gloria , Becattini Simone , Preite Silvia , Fuschillo Dario , Percivalle Elena , Sallusto Federica , Gerna Giuseppe , Corti Davide , Lanzavecchia Antonio 
Published: December 2014

Significance
To design an effective subunit vaccine, it is essential to identify the most relevant protective antigen. One way to achieve this goal is to analyze, at the clonal level, the human antibody response and identify the molecules targeted by the most effective neutralizing antibodies. Here we provide an example of this approach in the case of human cytomegalovirus (HCMV), a pathogen causing severe disease in newborns and immunosuppressed individuals. Through the analysis of the human antibody response to HCMV, we identified the gHgLpUL128L pentamer as the target of the most potent neutralizing antibodies and demonstrated that a pentamer vaccine elicited in mice extremely high levels of HCMV neutralizing antibodies. This example illustrates a general approach to develop subunit vaccines against complex pathogens.
American mastodon extirpation in the Arctic and Subarctic predates human colonization and terminal Pleistocene climate change
Authors: Zazula Grant D. , MacPhee Ross D. E. , Metcalfe Jessica Z. , Reyes Alberto V. , Brock Fiona , Druckenmiller Patrick S. , Groves Pamela , Harington C. Richard , Hodgins Gregory W. L. , Kunz Michael L. , Longstaffe Fred J. , Mann Daniel H. , McDonald H. Gregory , Nalawade-Chavan Shweta , Southon John R. 
Published: December 2014

SignificanceNew radiocarbon (14C) dates on American mastodon (Mammut americanum) fossils in Alaska and Yukon suggest this species suffered local extirpation before terminal Pleistocene climate changes or human colonization. Mastodons occupied high latitudes during the Last Interglacial (∼125,000–75,000 y ago) when forests were established. Ecological changes during the Wisconsinan glaciation (∼75,000 y ago) led to habitat loss and population collapse. Thereafter, mastodons were limited to areas south of the continental ice sheets, where they ultimately died out ∼10,00014C years B.P. Extirpation of mastodons and some other megafaunal species in high latitudes was thus independent of their later extinction south of the ice. Rigorous pretreatment was crucial to removing contamination from fossils that originally yielded erroneously “young”14C dates.
Dendrites are dispensable for basic motoneuron function but essential for fine tuning of behavior
Authors: Ryglewski Stefanie , Kadas Dimitrios , Hutchinson Katie , Schuetzler Natalie , Vonhoff Fernando , Duch Carsten 
Published: December 2014

SignificanceApproximately 100 billion neurons in our brain form 100 trillion synapses onto 100,000 miles of dendritic cable. Accordingly, dendritic defects are consistent anatomical correlates of numerous brain diseases, but specific causality remains unproven. Here we genetically remove dendrites inDrosophilamotoneurons, followed by analysis of functional outcomes. We find that dendrites are surprisingly dispensable for basic nervous system function and simple behavioral tasks. By contrast, highly complex dendritic architecture is required for adaptive refinement of sophisticated motor tasks that are vital for survival and reproduction. Here the degree of dendritic defect scales with the degree of performance deficit. We postulate that during evolution the maintenance of complex dendritic structure is under high selective pressure.
Conformational dynamics of a crystalline protein from microsecond-scale molecular dynamics simulations and diffuse X-ray scattering
Authors: Wall Michael E. , Van Benschoten Andrew H. , Sauter Nicholas K. , Adams Paul D. , Fraser James S. , Terwilliger Thomas C. 
Published: December 2014

Significance
A major challenge of protein crystallography is to accurately describe protein structure variations. Whereas Bragg peaks only yield a picture in which the variations are superimposed, diffuse X-ray scattering (diffraction between the peaks) reports on the way different atoms move together and can be used to increase the accuracy of models. We have performed a molecular-dynamics (MD) simulation of crystalline staphylococcal nuclease, yielding a rich picture of functionally important motions. This simulation is 100-fold longer than previous studies and yields reproducible calculations of diffuse intensity, overcoming a major challenge in the field. Experimental data support the MD models and indicate that diffuse scattering can be used both to validate and to improve MD simulations.
Label-free imaging of Schwann cell myelination by third harmonic generation microscopy
Authors: Lim Hyungsik , Sharoukhov Denis , Kassim Imran , Zhang Yanqing , Salzer James L. , Melendez-Vasquez Carmen V. 
Published: December 2014

Significance
Myelin, a specialized membrane wrapping around the axon, is crucial for proper neuronal information processing. We describe a label-free imaging method, i.e., third harmonic generation microscopy (THGM), for visualization of Schwann cell myelination in live culture and ex vivo and in vivo tissue. THGM is capable of imaging compact myelin as well as non–compact subcellular domains, including nodal segments, Schmidt–Lanterman incisures, and Cajal bands, thus attractive for elucidating their functional roles; it also facilitates image-based morphometry, allowing the g-ratio of myelinated fibers to be measured in physiological conditions. The demonstrated capabilities of THGM are valuable for investigating the intricate interaction between axon and myelin-forming glial cell underlying formation and maintenance of myelin in the peripheral nervous system.
Local plant names reveal that enslaved Africans recognized substantial parts of the New World flora
Authors: van Andel Tinde R. , van ‘t Klooster Charlotte I. E. A. , Quiroz Diana , Towns Alexandra M. , Ruysschaert Sofie , van den Berg Margot 
Published: December 2014

SignificanceEnslaved Africans had to familiarize themselves with the American flora, which was largely alien to them, to survive. The process of species recognition, knowledge acquisition, and replacement has hardly been documented. We compared 2,350 Afro-Surinamese vernacular plant names with those vernacular plant names used in western Africa for botanically related taxa. Sixty-five percent of the Afro-Surinamese plant names contained European lexical elements, but among Maroons, descendants of escaped slaves, more than 40% of the vernaculars showed strong resemblance in sound, structure, and meaning to African plant names for related taxa. The greatest correspondence was found among plant names from Gabon and Angola, the main areas where the Dutch purchased their slaves. Our paper shows that Africans recognized substantial parts of the American flora.