bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cerebellum and brain stem volume loss in relapsing remission multiple sclerosis by MRI volumetry: relation to neurological disability score and number of relapses
Authors: Elzayady Magdy , Debees Naglaa Lotfy , Khalil Mohamed , Dawoud Mohammed Mahmoud 
Published: January 2021

Abstract
Background
MRI is the method of choice in the diagnosis of MS as well as in monitoring the disease activity. MRI volumetry is used to assess whole or regional brain volume loss which reflects neurodegenerative aspect of the disease and plays an important role in all stages of disease. The aim of this work is to study MRI volumetry in the evaluation of cerebellum and brain stem volume loss in RRMS patients and its correlation with neurological disability score and number of relapses.

Results
Volumes of whole brainstem, medulla, and pons showed a significant decrease in RRMS cases compared to controls (p < 0.05). Brainstem volume had a mean volume of 22.17 and 25.09 cm3 in cases and controls, respectively. However, midbrain volume showed no significant difference between cases and controls (p = 0.134). Volume of left cerebellar cortex showed a significant decrease in RRMS cases compared to controls (p < 0.001). It had mean volumes of 81.64 and 92.14 ml in cases and controls, respectively, at left cerebellar hemisphere, while right cerebellar hemisphere cortex volumes were 80.37 and 91.97 ml in cases and controls, respectively. Cerebellar white matter showed no significant volume decrease in cases and controls.

Conclusion
Volumetric MR imaging is an important tool for quantifying the MS disease, assesses MS activity, progression, and tissue loss. The degree and the pattern of atrophy on MRI images correlate significantly with the neurological disability score and number of relapses.
Domain multiplexed computer-generated holography by embedded wavevector filtering algorithm
Authors: Wu Lin , Zhang Ziyang 
Published: January 2021

AbstractComputer-generated holography can obtain the wavefront required for constructing arbitrary intensity distributions in space. Currently, speckle noises in holography remain an issue for most computational methods. In addition, there lacks a multiplexing technology by which images from a single hologram and light source can be switched by a lens. In this work, we first come up with a new algorithm to generate holograms to project smoother images by wavevector filtering. Thereupon, we propose a unique multiplexing scheme enabled by a Fourier lens, as the incident light can be decomposed either by a superposition of spherical waves or plane waves. Different images are obtained experimentally in the spatial and wavevector domains, switchable by a lens. The embedded wavevector filtering algorithm provides a new prospective for speckle suppression without the need for postprocessing. The multiplexing technology can double the capacity of current holographic systems and exhibits potential for various interesting display applications.
Determinants of revenue management practices and their impacts on the financial performance of hotels in Kenya: a proposed theoretical framework
Authors: Murimi Michael , Wadongo Billy , Olielo Tom 
Published: January 2021

AbstractThis conceptual paper aims at identifying a theoretical framework for the determinants of revenue management (RM) practices and their impacts on the financial performance of hotels. To create this framework, a two-phased process is employed where the first stage involves an explicit examination of the literature related to practices of revenue management and their determinants and to hotel financial performance. The second stage involves an enhancement of the framework. The theoretical structure is developed based on past theoretical explanations, and empirical analysis is conducted in the fields of revenue management. The researchers propose a theoretical framework illustrating how revenue management practices and their determinants affect the financial performance of Kenyan hotels. The use of contingency theory and its justifications and inadequacies among studies on revenue management in hotels is highlighted. The methods highlighted by the reviewed theoretical framework may be utilized to organize revenue management (RM) practices and their determinants for Kenyan hotels. Measurements for the financial performance of hotels are also described. Last, the researchers call for empirical research that authenticates the proposed model using a cross-sectional survey. The present work can inspire scholars and specialists to determine how RM practices and their determinants impact the financial performance of hotels. By assimilating knowledge from numerous disciplines, this paper emphasizes aggregated awareness surrounding the conceptualization of RM, RM practices adopted in hotels, and the financial performance of hotels.
Out-of-time-order correlation and detection of phase structure in Floquet transverse Ising spin system
Authors: Kumar Shukla Rohit , Kamalakar Naik Gautam , Mishra Sunil Kumar 
Published: January 2021

Abstract
We study the out-of-time-order correlation (OTOC) of the Floquet transverse Ising model and use it to verify the phase diagram of the system. First, we present the exact analytical solution of the transverse magnetization OTOC using the Jorden-Wigner transformation. We calculate the speed of correlation propagation and analyze the behavior of the revival time with the separation between the observables. In order to get the phase structure of the Floquet transverse Ising system, we use the longitudinal magnetization OTOC as it is known to serve as an order parameter of the system. We show the phase structure numerically in the transverse Ising Floquet system by using the long time average of the longitudinal magnetization OTOC. In both the open and the closed chain systems, we find distinct phases out of which two are paramagnetic (0-paramagnetic and π-paramagnetic), and two are ferromagnetic (0-ferromagnetic and π-ferromagnetic) as defined in the literature.
Development of species-specific SCAR markers for identification and authentication of three rare Peninsular Malaysian endemic Coelogyne (Orchidaceae) orchids
Authors: Kok Hon Yoh , Yong Christina Seok-Yien , Abdullah Janna Ong , Go Rusea 
Published: January 2021

Background: Coelogyne kaliana, Coelogyne stenochila and Coelogyne tiomanensis are three valuable rare orchid species endemic to Peninsular Malaysia, currently rampantly traded illegally via the internet and through local nurseries, which label them as hybrids to avoid enforcement detection. Drastic measures to ensure the continued existence of their populations in the wild should be introduced as they are rapidly diminishing into extinction, including the development of rapid and accurate species-specific identification tools. These three orchid species are highly similar morphologically and currently it is impossible to distinguish among them without their reproductive structures. Methods: RAPD-based species-specific SCAR markers were developed to distinguish and authenticate the identity of these three endemic Peninsular Malaysian Coelogyne species. Results: Three SCAR markers were successfully developed in this study. SCAR marker primer pair, CKL_f / CKL_r was specific to C. kaliana as it produced a unique single band of 271 bp but not in C. stenochila and C. tiomanensis. SCAR marker primer pair CST_f / CST_r amplified a single band of 854 bp in C. stenochila and two bands of different sizes (372 bp and 858 bp) in C. tiomanensis, but no amplification in C. kaliana. The third SCAR marker primer pair, CTI_f / CTI_r produced a single band (about 500 bp) for both C. stenochila and C. tiomanensis, but showed no amplification in C. kaliana. Conclusions: Although not all these SCAR markers were species amplification specific, they could be used to discriminate among the three Coelogyne species effectively. Accurate species identification is one of the most important steps to allow a proper management plan to be established in the effort to conserve these three endangered orchid species of Peninsular Malaysia. Besides, it could effectively put a stop to the illegal trading of these rare endangered orchid species worldwide.
Risk, Ambiguity, and the Value of Diversification
Authors: Berger Loïc , Eeckhoudt Louis 
Published: January 2021

Diversification is a basic economic principle that helps to hedge against uncertainty. It is, therefore, intuitive that both risk aversion and ambiguity aversion should positively affect the value of diversification. In this paper, we show that this intuition (1) is true for risk aversion but (2) is not necessarily true for ambiguity aversion. We derive sufficient conditions, showing that, contrary to the economic intuition, ambiguity and ambiguity aversion may actually reduce the diversification value. This paper was accepted by Manel Baucells, decision analysis.
Frequency comb generation in a pulse-pumped normal dispersion Kerr mini-resonator
Authors: Xu Yiqing , Sharples Alexander , Fatome Julien , Coen Stéphane , Erkintalo Miro , Murdoch Stuart G. 
Published: January 2021

Kerr microresonators driven in the normal dispersion regime typically require the presence of localized dispersion perturbations, such as those induced by avoided mode crossings, to initiate the formation of optical frequency combs. In this work, we experimentally demonstrate that this requirement can be lifted by driving the resonator with a pulsed pump source. We also show that controlling the desynchronization between the pump repetition rate and the cavity free-spectral range (FSR) provides a simple mechanism to tune the center frequency of the output comb. Using a fiber mini-resonator with a radius of only 6 cm, we experimentally present spectrally flat combs with a bandwidth of 3 THz whose center frequency can be tuned by more than 2 THz. By driving the cavity at harmonics of its 0.54 GHz FSR, we are able to generate combs with line spacings selectable between 0.54 and 10.8 GHz. The ability to tune both the center frequency and frequency spacing of the output comb highlights the flexibility of this platform. Additionally, we demonstrate that under conditions of large pump-cavity desynchronization, the same cavity also supports a new, to the best of our knowledge, form of Raman-assisted anomalous dispersion cavity soliton.
Nonlinear frequency conversion of 3D optical bottle beams generated using a single axicon
Authors: Rao A. Srinivasa , Yadav Deepika , Samanta G. K. 
Published: January 2021

We demonstrate a novel experimental scheme to generate and study the nonlinear frequency conversion of a three-dimensional (3D) optical Bessel bottle beam (BBB). Using a single axicon and standard optical components and controlling the spot size and divergence of the input Gaussian beam to the axicon, we have generated stable micron-size, high-power optical BBB with tunable spatial characteristics. The BBB has a series of low-intensity regions surrounded by high intensity with diameters of

∼

30

µ

m

and 17 µm, respectively, at a variable period of 2.3 to 6.4 mm along with the beam propagation. Using the single-pass second harmonic generation (SHG) of femtosecond BBB at 1064 nm in a bismuth triborate nonlinear crystal, we have generated BBB at 532 nm with output power as high as 75 mW and single-pass SHG efficiency of 1.9%. We also observed the self-healing of the BBB at both pump and SHG wavelengths. It is interesting to note that the pump beam truncation shows self-healing in the SHG beam. Such observation proves the direct transfer of the pump’s spatial characteristics to the SHG beam in the nonlinear process, potentially useful for imaging even in the turbid medium in biology. This generic scheme can be used at different wavelengths and timescales (continuous-wave to ultrafast).
What have we learned about positive changes experienced during COVID-19 lockdown? Evidence of the social patterning of change
Authors: Williams Lynn , Rollins Lesley , Young David , Fleming Leanne , Grealy Madeleine , Janssen Xanne , Kirk Alison , MacDonald Bradley , Flowers Paul 
Published: January 2021

Background
Multiple studies have highlighted the negative impact of COVID-19 and its particular effects on vulnerable sub-populations. Complementing this work, here, we report on the social patterning of self-reported positive changes experienced during COVID-19 national lockdown in Scotland.

Methods
The CATALYST study collected data from 3342 adults in Scotland during weeks 9–12 of a national lockdown. Using a cross-sectional design, participants completed an online questionnaire providing data on key sociodemographic and health variables, and completed a measure of positive change. The positive change measure spanned diverse domains (e.g., more quality time with family, developing new hobbies, more physical activity, and better quality of sleep). We used univariate analysis and stepwise regression to examine the contribution of a range of sociodemographic factors (e.g., age, gender, ethnicity, educational attainment, and employment status) in explaining positive change.

Results
There were clear sociodemographic differences across positive change scores. Those reporting higher levels of positive change were female, from younger age groups, married or living with their partner, employed, and in better health.

Conclusion
Overall our results highlight the social patterning of positive changes during lockdown in Scotland. These findings begin to illuminate the complexity of the unanticipated effects of national lockdown and will be used to support future intervention development work sharing lessons learned from lockdown to increase positive health change amongst those who may benefit.
Incidents of aggression in German psychiatric hospitals: Is there an increase?
Authors: Eisele Frank , Flammer Erich , Steinert Tilman 
Published: January 2021

Introduction
In a meta-analysis of international studies, 17% of admitted patients in psychiatric hospitals had exhibited violent behavior toward others. Reported data from studies in Germany were considerably lower until recent years. However, studies examining only single hospitals, as well as the quality of the data itself, have raised questions as to the validity of these findings. Indeed, a debate currently exists as to whether there has, in fact, been an increase of violent incidents in German mental institutions.

Methods
In a group of 10 hospitals serving about half the population of the Federal State of Baden-Wuerttemberg with 11 million inhabitants, the Staff Observation Aggression Scale–Revised (SOAS-R) was introduced into patients’ electronic charts as part of routine documentation. Data recording was strongly supported by staff councils and unions. A completed data set is now available for the year 2019. For one hospital, data are available since 2006. Due to some doubts with respect to fully covering self-directed aggression, we restricted the analysis to aggression toward others and toward objects.

Results
In 2019, 17,599 aggressive incidents were recorded in 64,367 admissions (1,660 staying forensic psychiatric inpatients included). 5,084 (7.90%) of the admitted cases showed aggressive behavior toward others. Variation between hospitals was low to modest (SD = 1.50). The mean SOAS-R score was 11.8 (SD between hospitals 1.20%). 23% of the incidents resulted in bodily harm. The percentage of patients showing violent behavior was highest among patients with organic disorders (ICD-10 F0) and lowest among patients with addictive or affective disorders (F1, F3, F4). Forensic psychiatry had the highest proportion of cases with aggressive behavior (20.54%), but the number of incidents per bed was lower than in general adult psychiatry and child and adolescent psychiatry (indicating a lower risk for staff). In the hospital with longer-term recordings available, an increase could be observed since 2010, with considerable variation between years.

Conclusions
This is the most robust estimate of the frequency of violent incidents in German psychiatric hospitals thus far. The incidence is about half of what has been reported internationally, probably due to sample selection bias in previous studies and a relatively high number of hospital beds in Germany. Available data suggest an increase of violent incidents over the last ten years; however, it is unclear to which extent this is due to increased reporting.
Variability in Cerebral Palsy Diagnosis
Authors: Aravamuthan Bhooma R. , Fehlings Darcy , Shetty Sheetal , Fahey Michael , Gilbert Laura , Tilton Ann , Kruer Michael C. 
Published: January 2021

BACKGROUND:
Cerebral palsy (CP) is the most common childhood motor disability. The emergence of genetic CP etiologies, variable inclusion of hypotonic CP in international registries, and involvement of different medical disciplines in CP diagnosis can promote diagnostic variability. This variability could adversely affect patients’ understanding of their symptoms and access to care. Therefore, we sought to determine the presence and extent of practice variability in CP diagnosis.

METHODS:
We surveyed physicians in the United States and Canada interested in CP on the basis of membership in the American Academy of Cerebral Palsy and Developmental Medicine or the Child Neurology Society Neonatal Neurology, Movement Disorders, or Neurodevelopmental Disabilities Special Interest Groups. The survey included the 2007 consensus definition of CP and 4 hypothetical case scenarios.

RESULTS:
Of 695 contacted physicians, 330 (47%) completed the survey. Two scenarios yielded consensus: (1) nonprogressive spastic diplegia after premature birth with periventricular leukomalacia on brain MRI (96% would diagnose CP) and (2) progressive spastic diplegia (92% would not diagnose CP). Scenarios featuring genetic etiologies or hypotonia as the cause of nonprogressive motor disability yielded variability: only 46% to 67% of practitioners would diagnose CP in these settings.

CONCLUSIONS:
There is practice variability in whether a child with a nonprogressive motor disability due to a genetic etiology or generalized hypotonia will be diagnosed with CP. This variability occurred despite anchoring questions with the 2007 consensus definition of CP. On the basis of these results, we have suggested ways to reduce diagnostic variability, including clarification of the consensus definition.
The prediction of repeated sprint and speed endurance performance by parameters of critical velocity models in soccer
Authors: Arı Erdal , Deliceoğlu Gökhan 
Published: January 2021

Background and Study Aim. The prediction of running anaerobic sprint test and 800 m performance by parameters of critical velocity was examined in this study.
Material and Methods. The participants of study were consisted of thirteen amateur soccer players (n=13, age=22.69±5.29 years, weight=72.46±6.32 kg, height=176.92±6.73 cm). The 800 and 2400 m running tests were performed for determination of critical velocity and anaerobic distance capacity. The critical velocity and anaerobic distance capacity were determined by three mathematical models (linear total distance, linear velocity, non-linear two parameter model). The repeated sprint and sprint endurance ability was determined by running anaerobic sprint test and 800 m running test. The simple and multiple linear regression analysis was used for prediction of dependent variables (running anaerobic sprint test and 800 m running performance) by independent variables (critical velocity and anaerobic distance capacity) of study. The correlation between variables was determined by Pearson correlation coefficient.
Results. It was found that anaerobic distance capacity was a significant predictor of running anaerobic sprint test and 800 m running performance (p˂0.05). However, it was determined that critical velocity predicted significantly only time parameters of running anaerobic sprint test and 800 m test (p˂0.05). Also, the parameters of 800 m test (except for average velocity) were significantly predicted by running anaerobic sprint test parameters (p˂0.05).
Conclusions. It may be concluded that anaerobic distance capacity is an indicator of repeated sprint and speed endurance ability in soccer and may be used in improvement of sprint endurance performance.
Electroencephalography: basic biophysical and technological aspects important for clinical applications
Authors: Beniczky Sándor , Schomer Donald L. 
Published: January 2021

AbstractElectroencephalography (EEG) is the most commonly used functional investigative method in epilepsy. The goal of this educational review paper is to summarize the most important aspects related to the biophysical phenomena of EEG signal generation and the technical features that a clinician needs to understand in order to read and interpret EEGs. We explain the EEG electrodes and recording arrays, amplifiers, filters, analogue‐to‐digital conversion and signal display. We describe the advantages and disadvantages of the different montages and the indications for the various types of EEG recordings and provocative maneuvers. We explain how to use topographic maps to estimate the source of the cortical generator.
Vertiginous epilepsy: documentation of clinical and electrophysiological findings of nine patients
Authors: Surmeli Reyhan , Yalcin Ayse Destina , Surmeli Mehmet , Gunay Gozde 
Published: January 2021

AbstractAims. Epileptic vertigo is often a diagnostic problem. We aimed to present the clinical and electrophysiological features of patients with epileptic vertigo with a view to addressing the pathophysiology of this rare aura symptom.Methods. Nine epileptic vertigo patients were included in the study. All patients were subjected to neuro‐otologic examination, interictal electroencephalogram (EEG), audiogram, cervical vestibular evoked myogenic potential testing (cVEMP), video head impulse testing (vHIT) and brain magnetic resonance imaging (MRI).Results. Eight patients described their aura as epileptic vertigo and one as dizziness. In three patients, auditory hallucinations preceded epileptic vertigo. The semiology of epileptic vertigo was true vertigo in five patients, vertigo with nausea in two patients and vertigo with hearing loss in one patient. Two patients suffered from focal seizures, and in seven patients the seizures were evaluated as focal to bilateral tonic‐clonic seizures. MRI was normal in all patients. EEG was abnormal in all cases and showed high‐voltage spike or spike‐slow‐wave complexes, or both, located more frequently in the temporal region, more left than right. On vHIT examination, abnormal responses were recorded bilaterally or unilaterally in five patients. Similarly, cVEMP revealed no response bilaterally or unilaterally in five patients. In three patients, the side of no response to cVEMP corresponded to the side of epileptiform pathology based on EEG. Two patients with bilateral abnormalities on EEG showed bilateral abnormalities either on cVEMP or vHIT, or on both. Taken together, these findings support the involvement of the brainstem connections of the peripheral vestibular system in vertiginous epilepsy.Conclusion. The pathological results of vestibular tests in the majority of our patients, combined with the EEG abnormalities, support the hypothesis of system epilepsies which is based on the dysfunction of specific neural systems.