bluuebunny/crossref_metadata_2025_split huggingface dataset:
Projector‐based augmented reality system for interventional visualization inside MRI scanners
Authors: Mewes André , Heinrich Florian , Kägebein Urte , Hensen Bennet , Wacker Frank , Hansen Christian 
Published: August 2018

AbstractBackgroundNavigation support in interventional magnetic resonance imaging (MRI) is separated from the operating field, which makes it difficult to interpret positions and orientations and to coordinate the necessary hand movements.MethodsWe developed a projector‐based augmented reality system to enable visual navigation of tracked instruments on pre‐planned paths and visualization of risk structures directly on the patient inside the MRI bore. To assess the accuracy of the system, a user study was carried out with clinicians in a needle navigation test scenario.ResultsThe targets were reached with an error of 1.7 ± 0.5 mm and the entry points with an error of 1.7 ± 0.8 mm.ConclusionThe accuracy results are similar to those reached by live image–guided interventions and related work and confirm that this projective augmented reality prototype for the interventional MRI can serve as a platform for current and future research in augmented reality visualization and dynamic registration.
Fine orientation control of an insertable robotic camera system for single incision laparoscopic surgery
Authors: Yazdanpanah Abdolmalaki Reza , Liu Xiaolong , Mancini Gregory J. , Tan Jindong 
Published: August 2018

AbstractBackgroundInsertable laparoscopic camera systems were developed to improve the minimally invasive surgeries. Robotic degrees of freedom for an insertable laparoscopic camera are required to adjust the camera's orientation and position inside an abdominal cavity.MethodsThis paper demonstrates an insertable magnetic actuated robotic camera system with two‐degree‐of‐freedom (2‐DoF) orientation control for single incision laparoscopic surgery. The camera system design consists of an external magnetic control unit and a fully insertable camera capsule. This system features a unified mechanism for anchoring, navigating, and rotating the insertable camera capsule by externally generated rotational magnetic field from the control unit. The motor‐free camera capsule is encapsulated in an one‐piece housing with two ring‐shaped tail‐end magnets and one cylindrical central magnet. The control unit that positioned externally consists of both permanent magnets and electromagnetic coils to generate rotational magnetic field and control the camera capsule.ResultsThe experimental investigations indicated that the camera control system can achieve less than 1° control accuracies with average errors 0.594° and 0.524° for tilt motion and pan motion, respectively.ConclusionThe designed control system provides fine orientation control for the insertable camera capsule which guarantees proper vision for the surgeon during single incision laparoscopic surgery.
Stroke and dementia risk: A systematic review and meta‐analysis
Authors: Kuźma Elżbieta , Lourida Ilianna , Moore Sarah F. , Levine Deborah A. , Ukoumunne Obioha C. , Llewellyn David J. 
Published: August 2018

AbstractIntroductionStroke is an established risk factor for all‐cause dementia, though meta‐analyses are needed to quantify this risk.MethodsWe searched Medline, PsycINFO, and Embase for studies assessing prevalent or incident stroke versus a no‐stroke comparison group and the risk of all‐cause dementia. Random effects meta‐analysis was used to pool adjusted estimates across studies, and meta‐regression was used to investigate potential effect modifiers.ResultsWe identified 36 studies of prevalent stroke (1.9 million participants) and 12 studies of incident stroke (1.3 million participants). For prevalent stroke, the pooled hazard ratio for all‐cause dementia was 1.69 (95% confidence interval: 1.49–1.92; P < .00001; I2 = 87%). For incident stroke, the pooled risk ratio was 2.18 (95% confidence interval: 1.90–2.50; P < .00001; I2 = 88%). Study characteristics did not modify these associations, with the exception of sex which explained 50.2% of between‐study heterogeneity for prevalent stroke.DiscussionStroke is a strong, independent, and potentially modifiable risk factor for all‐cause dementia.
Magnetic reconnection driven by intense lasers
Authors: Zhong Jiayong , Yuan Xiaoxia , Han Bo , Sun Wei , Ping Yongli 
Published: August 2018

Laser-driven magnetic reconnection (LDMR) occurring with self-generated B fields has been experimentally and theoretically studied extensively, where strong B fields of more than megagauss are spontaneously generated in high-power laser–plasma interactions, which are located on the target surface and produced by non-parallel temperature and density gradients of expanding plasmas. For properties of the short-lived and strong B fields in laser plasmas, LDMR opened up a new territory in a parameter regime that has never been exploited before. Here we review the recent results of LDMR taking place in both high and low plasma beta environments. We aim to understand the basic physics processes of magnetic reconnection, such as particle accelerations, scale of the diffusion region, and guide field effects. Some applications of experimental results are also given especially for space and solar plasmas.
Convective carbon dioxide dissolution in a closed porous medium at low pressure
Authors: Wen Baole , Akhbari Daria , Zhang Li , Hesse Marc A. 
Published: August 2018

Motivated by the persistence of natural carbon dioxide ($\text{CO}_{2}$) fields, we investigate the convective dissolution of $\text{CO}_{2}$ at low pressure (below 1 MPa) in a closed system, where the pressure in the gas declines as convection proceeds. This introduces a negative feedback that reduces the convective dissolution rate even before the brine becomes saturated. We analyse the case of an ideal gas with a solubility given by Henry’s law, in the limits of very low and very high Rayleigh numbers. The equilibrium state in this system is determined by the dimensionless dissolution capacity, $\unicode[STIX]{x1D6F1}$, which gives the fraction of the gas that can be dissolved into the underlying brine. Analytic approximations of the pure diffusion problem with $\unicode[STIX]{x1D6F1}>0$ show that the diffusive base state is no longer self-similar and that diffusive mass transfer declines rapidly with time. Direct numerical simulations at high Rayleigh numbers show that no constant flux regime exists for $\unicode[STIX]{x1D6F1}>0$; nevertheless, the quantity $F/C_{s}^{2}$ remains constant, where $F$ is the dissolution flux and $C_{s}$ is the dissolved concentration at the top of the domain. Simple mathematical models are developed to predict the evolution of $C_{s}$ and $F$ for high-Rayleigh-number convection in a closed system. The negative feedback that limits convection in closed systems may explain the persistence of natural $\text{CO}_{2}$ accumulations over millennial time scales.
Dietary factors are associated with serum uric acid trajectory differentially by race among urban adults
Authors: Beydoun May A. , Fanelli-Kuczmarski Marie T. , Canas Jose-Atilio , Beydoun Hind A. , Evans Michele K. , Zonderman Alan B. 
Published: August 2018

AbstractSerum uric acid (SUA), a causative agent for gout, is linked to dietary factors, perhaps differentially by race. Cross-sectional (SUAbase, i.e. baseline SUA) and longitudinal (SUArate; i.e. annual rate of change in SUA) associations of SUA with diet were evaluated across race and sex–race groups, in a large prospective cohort study of urban adults. Of 3720 African American (AA) and White urban adults participating in the Healthy Aging in Neighborhoods of Diversity across the Life Span study, longitudinal data (2004–2013,k=1·7 repeats, follow-up, 4·64 (sd0·93) years) onn2138 participants were used. The main outcome consisted of up to two repeated measures on SUA. Exposures included the dietary factors such as ‘added sugar’, ‘alcoholic beverages’, ‘red meat’, ‘total fish’, ‘legumes’, ‘total dairy product’, ‘caffeine’, ‘vitamin C’ and a composite measure termed ‘dietary urate index’. Mixed-effects linear regression models were conducted, stratifying by race and by race×sex. A positive association between legume intake and SUAratewas restricted to AA, whereas alcohol intake was positively associated with SUAbaseoverall without racial differences. Added sugars were directly related to SUAbaseamong White men (P<0·05 for race×sex interaction), whereas dairy product intake was linked with slower SUArateamong AA women, unlike among White women. Nevertheless, dairy product intake was associated with a lower SUAbaseamong Whites. Finally, the dietary urate index was positively associated with both SUAbaseand SUArate, particularly among AA. In sum, race and sex interactions with dietary intakes of added sugars, dairy products and legumes were detected in determining SUA. Similar studies are needed to replicate these findings.
Nasal disease and quality of life in athletes
Authors: Walker A C , Surda P , Rossiter M , Little S A 
Published: August 2018

AbstractObjectivesNasal disease imposes a significant disease burden upon the individual in the general population, but is relatively under studied in athletes. This study sought to define the frequency of nasal symptoms in the active population, and to quantify the impact of these symptoms on quality of life and on the frequency of upper respiratory tract infections.ResultsA total of 296 participants completed the study (246 athletes and 50 sedentary controls). Nasal symptoms were significantly more frequent in the active group than in the sedentary controls (70 per cent vs 52 per cent). Upper respiratory tract infections were significantly more common in athletes with regular nasal symptoms than in athletes without nasal symptoms. Quality-of-life scores, as measured by the 22-item Sino-Nasal Outcome Test, were significantly worse in athletes with regular nasal symptoms.ConclusionThis study suggests that regular exercise is associated with a significant increase in the prevalence of troubling nasal symptoms, and nasal symptoms in athletes are associated with increased susceptibility to upper respiratory tract infections. Quality of life was negatively affected, confirming the importance of nasal health to athlete welfare.
Analysis of path following and obstacle avoidance for multiple wheeled robots in a shared workspace
Authors: Tanveer M. Hassan , Recchiuto Carmine T. , Sgorbissa Antonio 
Published: August 2018

SUMMARYThe article presents the experimental evaluation of an integrated approach for path following and obstacle avoidance, implemented on wheeled robots. Wheeled robots are widely used in many different contexts, and they are usually required to operate in partial or total autonomy: in a wide range of situations, having the capability to follow a predetermined path and avoiding unexpected obstacles is extremely relevant. The basic requirement for an appropriate collision avoidance strategy is to sense or detect obstacles and make proper decisions when the obstacles are nearby. According to this rationale, the approach is based on the definition of the path to be followed as a curve on the plane expressed in its implicit formf(x, y) = 0, which is fed to a feedback controller for path following. Obstacles are modeled through Gaussian functions that modify the original function, generating a resulting safe path which – once again – is a curve on the plane expressed asf′(x, y) = 0: the deformed path can be fed to the same feedback controller, thus guaranteeing convergence to the path while avoiding all obstacles. The features and performance of the proposed algorithm are confirmed by experiments in a crowded area with multiple unicycle-like robots and moving persons.
The Great Repudiator and Immigration Reform: Ronald Reagan and the Immigration Reform and Control Act of 1986
Authors: Kaplowitz Craig A. 
Published: August 2018

Abstract:In 1981, Ronald Reagan created a task force intended to gain the initiative on immigration reform. But immigration reform presented obstacles to his political stance in repudiation of his Democratic predecessors. After four years of wrangling, internally as well as with Congress, many on the Reagan team viewed the immigration task force as having shackled the president to an unwinnable issue. Frustrated politically, Reagan aides shifted focus to an emerging presidential tactic—the signing statement. This allowed the president to sign the Immigration Reform and Control Act while setting important precedents for his larger conservative agenda. The trajectory from presidential task force to presidential signing statement on immigration reform reveals the challenges Reagan faced on policy issues outside his core priorities, and also the development of a tactic to maneuver through the challenges. Immigration reform became less about immigration than about serving the administration’s larger core priorities.
Does global titling sustain informal taxation? Evidence from Ecuadorian urban slums
Authors: Boichev Georgi 
Published: August 2018

AbstractLow-income urban neighborhoods in developing countries receive low levels of public services, often not supplemented by community provision due to low rates of informal tax compliance. This paper presents evidence from low-income neighborhoods in Quito, Ecuador using an IV empirical strategy that the global titling of neighborhoods sustains informal taxation. The estimates reveal a sizable average effect of global titling on in-kind labor household that is drawn from a broad base. Evidence is also found which suggests that the possession of a global title provides a neighborhood organisation with tools that deter free-riding behavior even among the individually-titled residents.
Individual Differences in Uncertainty Tolerance Are not Associated	With Cognitive Control Functions in the Flanker Task
Authors: Schroeder Philipp Alexander , Dignath David , Janczyk Markus 
Published: August 2018

Abstract. Cognitive control refers to the ability to make correct decisions concurrent to distracting information, and to adapt to conflicting stimulus configurations, eventually promoting goal-directed behavior. Previous research has linked individual differences in cognitive control to psychopathological conditions such as anxiety. However, a link with uncertainty tolerance (UT) has not been tested so far, although both constructs describe cognitive and behavioral performance in ambiguous situations, thus they share some similarities. We probed cognitive control in web-based experimentation (jsPsych) with a simple flanker task (N = 111) and a version without confounds in episodic memory (N = 116). Both experiments revealed two well-established behavioral indices: congruency effects (CEs) and congruency-sequence effects (CSEs). Only small-to-zero correlations emerged between CEs, UT, and need for cognitive closure (NCC), a personality trait inversely related to UT. A subtle correlation (r = .18) was noted in Experiment 2 between NCC and CSE. Throughout, Bayesian analyses provided anecdotal-to-moderate evidence for the null-hypotheses.
Error Propagation in the Derivation of Noble Gas Diffusion Parameters for Minerals From Step Heating Experiments
Authors: Ginster U. , Reiners P. W. 
Published: August 2018

AbstractStep heating is an important tool in the derivation of thermochronologic models based on diffusive noble‐gas loss from minerals. This technique investigates noble‐gas diffusion in minerals at length scales of natural crystals. Like any scientific measurement, step heating requires realistic assessment of assumptions and uncertainties; however, uncertainties are often not presented or roughly approximated. Here we propagate errors associated with temperature, step duration, evolved gas quantity, and diffusion domain size. Other potential error sources (e.g., nonideal shapes, fractures, and zonation of aliquots) are not discussed. We provide error propagation formulas for the derivation of diffusivities and diffusion parameters for infinite plane sheet, spherical, and infinite cylinder geometry. We show that a variance in uncertainty (heteroscedasticity) in diffusivity and temperature may lead to erroneous estimates of activation energy (Ea) and frequency factor (D0) and an underestimation of their uncertainties during unweighted regression. The effect becomes significant if the variance in uncertainty exceeds a factor of two to five. The effect of the difference inD0values is demagnified in the calculation of closure temperature (which calls on lnD0rather thanD0) and its uncertainty. To make this a practical resource, we provide spreadsheets with a step heating data set, diffusivity calculations with associated analytical error propagation formulas, and unweighted and weighted regression models to deriveEaandD0for all three geometries. We also provide spreadsheets with Monte Carlo and numerical error propagation for plane sheet geometry.
A New Method for Deriving Equatorial Plasma Bubble Velocity by Tracing OI 630 nm All‐Sky Images
Authors: Yu Tao , Li Mingyuan , Xia Chunliang , Zuo Xiaomin , Liu Zhizhao , Zhao Biqiang 
Published: August 2018

AbstractA new method for estimating the equatorial plasma bubbles (EPBs) motions from airglow emission all‐sky images is presented in this paper. This method, which is called cloud motion wind (CMW) and widely used in satellite observation of wind, could reasonably derive zonal and meridional velocity vectors of EPBs drift by tracking a series of successive airglow images. Airglow emission images data are available from all‐sky airglow camera in Hainan Fuke (19.5°N, 109.2°E) supported by China Meridional Project, which can receive the 630.0 nm emission from ionosphere F region at low latitudes to observe plasma bubbles. A series of pretreatment technology is utilized to preprocess the raw observation. Then the regions of plasma bubble extracted from the images are divided into several small tracing windows, and each tracing window can find a target window in the searching area in following image, which is considered as the position tracing window moved to. According to this, velocity of each tracing window was calculated by CMW. The maximum correlation coefficient is adopted to analyze the velocity of plasma bubbles due to its better performance than histogram of oriented gradient. All‐sky images from Hainan Fuke, an example on 17 September 2014, are analyzed to investigate the plasma bubble drift velocities using CMW. For comparison and validation, EPBs motions obtained from three traditional methods are also investigated. The advantages and disadvantages of using CMW are discussed. The results of CMW are compared with slant total electron contents data and show a good consistency, but some errors are also discussed.
Comparison of Subseasonal‐to‐Seasonal Model Forecasts for Major Stratospheric Sudden Warmings
Authors: Taguchi M. 
Published: August 2018

AbstractThis study explores forecasts for five distinctive major stratospheric sudden warmings (MSSWs) using subseasonal‐to‐seasonal prediction data with lead times up to about 2 weeks. Results reveal model‐to‐model variability of the forecasts, as some models, such as the European Centre for Medium‐Range Weather Forecasts and National Centers for Environmental Prediction models, forecast the MSSWs better. Results also demonstrate greater difficulty of forecasting the vortex split MSSWs (three of the five) than the vortex displacement MSSWs (the other two). It is also shown that the variable forecasts among different lead times and models for each MSSW are characterized by how well the models reproduce the weakenings and deformations of the stratospheric polar vortex around the MSSWs and the intensifications of tropospheric planetary waves before them. The variability is well captured by planetary wave activity, or poleward heat flux, in the lower stratosphere. This underlines the importance of enhanced planetary waves in the troposphere and lower stratosphere for successful forecasts of the forecasting MSSWs, although the causality between the MSSWs and enhanced planetary waves will deserve further investigation.
Study of Mean Wind Variations and Gravity Wave Forcing Via a Meteor Radar Chain and Comparison with HWM‐07 Results
Authors: Ma Zheng , Gong Yun , Zhang Shaodong , Zhou Qihou , Huang Chunming , Huang Kaiming , Dong Wenjun , Li Guozhu , Ning Baiqi 
Published: August 2018

AbstractWe present an analysis of long‐term observation of the mean winds in the mesosphere and lower thermosphere region. The neutral wind data are collected over the period of January 2009 to November 2017 from a chain of meteor radars along the 120°E meridian in the Northern Hemisphere which consists of four stations at Mohe (MH; 53.5°N, 122.3°E), Beijing (BJ; 40.3°N, 116.2°E), Wuhan (WH; 30.5°N, 114.6°E), and Sanya (SY; 18.3°N, 109.6°E). The annual oscillation dominates the neutral wind pattern at midlatitudes while both the annual oscillation and semiannual oscillations are important at low latitudes. The mean zonal wind pattern in midlatitudes exhibits two eastward jets. One is in the period from April to October above 85 km and the other is from November to March below 90 km. A reversal of the mean zonal winds from eastward to westward is observed in midlatitudes around the spring equinox. Gravity wave forcing during this season shows a rapid change from westward to eastward, which is consistent with the reversals. A three‐cell southward wind pattern is observed over WH and SY. A strong vertical wind shear with northward flow below ~90 km and southward flow above is observed over SY from September to April. Composite‐year comparisons between the observations and the Horizontal Wind Model‐07 show large discrepancies during winter time. HWM‐07 predictions agree with the meteor radar observations better in the zonal component than in the meridional component. The model predictions at low latitude are not as accurate as the middle latitudes.
Extreme Climate Event Changes in China in the 1.5 and 2 °C Warmer Climates: Results From Statistical and Dynamical Downscaling
Authors: Li Donghuan , Zou Liwei , Zhou Tianjun 
Published: August 2018

AbstractThis study compared statistical downscaling model (SD) and dynamical downscaling model (DD) for changes in extreme temperature and precipitation indices, driven by the same global climate model output, in the 1.5 and 2 °C warmer climates in China. Simple bias correction (BC) methods were used to correct the climatology of temperature and precipitation in both models. After BC, both models show comparable performance in reproducing the spatial distributions of the extreme temperature and precipitation indices. Corrected model data were used to analyze future changes. Changing patterns of the extreme temperature indices are similar in the two models. Compared with the 2 °C warmer climate, warming 0.5 °C less can help reduce about 6% of summer day (SU) and 11% of tropical night (TR) increases (relative to 1986–2005) in China. Specifically, the reduced values of TR in northwest and northeast China are larger than 30% and 70%, respectively, in both models. Extreme wet indices will increase in most parts of China in the warmer climates. In DD, 5‐day maximum precipitation (RX5day) will increase by approximately 10% and 14% in the 1.5 and 2 °C warmer climates, respectively, with maximal values (17% and 28%, respectively) occurring in north China. In SD, differences in extreme wet indices between the two warmer climates are small, and RX5day will increase more than 20% in northeast China. In DD, specific humidity will increase, and the East Asian summer monsoon will be enhanced in the warmer climates, favoring a larger increase in wet extremes in north China compared to other parts of east China.