bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal Trends in Use of Composite End Points in Major Cardiovascular Randomized Clinical Trials in Prominent Medical Journals
Authors: Tan Nigel S. , Ali Sammy H. , Lebovic Gerald , Mamdani Muhammad , Laupacis Andreas , Yan Andrew T.
Published: September 2017

Background—

Cardiovascular mortality has decreased over the past 5 decades, making it increasingly difficult to demonstrate significant benefits of new therapies in randomized clinical trials. We sought to determine whether the use of composite end points in major cardiovascular trials has changed over time and examine temporal trends in the clinical importance of individual components of these composite end points.

Methods and Results—

Using a validated search strategy, we searched MEDLINE for randomized trials of therapies for primary or secondary cardiovascular prevention published in
New England Journal of Medicine
,
The Lancet
, and the
Journal of the American Medical Association
between 1986 and 2015. We abstracted and categorized study population demographics, type of intervention, and primary and secondary outcomes. Composite end point components were ranked according to importance (minor, moderate, major, critical, and death) and temporal trends analyzed. In total, 604 of 2607 trials retrieved met inclusion criteria. Use of composite end points increased significantly over time from 18.8% between 1986 and 1990 to 83.0% between 2011 and 2015 (
P
<0.001). The number of components in the primary end point also increased significantly (median 1 in 1986–1990, median 3 in 2011–2015;
P
<0.001). Contemporary trials were more likely to include end points of lesser importance to patients (minor 3.1% and moderate 6.3% in 1986–1990, minor 4.5% and moderate 44.6% in 2011–2015;
P
<0.001). Use of death as the sole primary end point declined significantly over time (53.1% in 1986–1990, 17.9% in 2011–2015;
P
<0.001).

Conclusions—

Contemporary cardiovascular randomized clinical trials are more likely to use primary composite end points that contain a larger number of components. Furthermore, these composite end points have increasingly incorporated components of lesser clinical importance. Clinicians and policymakers interpreting results of randomized trials should recognize that the significance of individual components in a composite end point is often heterogeneous.
Incorporating Stroke Severity Into Hospital Measures of 30-Day Mortality After Ischemic Stroke Hospitalization
Authors: Schwartz Jennifer , Wang Yongfei , Qin Li , Schwamm Lee H. , Fonarow Gregg C. , Cormier Nicole , Dorsey Karen , McNamara Robert L. , Suter Lisa G. , Krumholz Harlan M. , Bernheim Susannah M.
Published: September 2017

Background and Purpose—

The Centers for Medicare & Medicaid Services publicly reports a hospital-level stroke mortality measure that lacks stroke severity risk adjustment. Our objective was to describe novel measures of stroke mortality suitable for public reporting that incorporate stroke severity into risk adjustment.

Methods—

We linked data from the American Heart Association/American Stroke Association Get With The Guidelines-Stroke registry with Medicare fee-for-service claims data to develop the measures. We used logistic regression for variable selection in risk model development. We developed 3 risk-standardized mortality models for patients with acute ischemic stroke, all of which include the National Institutes of Health Stroke Scale score: one that includes other risk variables derived only from claims data (claims model); one that includes other risk variables derived from claims and clinical variables that could be obtained from electronic health record data (hybrid model); and one that includes other risk variables that could be derived only from electronic health record data (electronic health record model).

Results—

The cohort used to develop and validate the risk models consisted of 188 975 hospital admissions at 1511 hospitals. The claims, hybrid, and electronic health record risk models included 20, 21, and 9 risk-adjustment variables, respectively; the C statistics were 0.81, 0.82, and 0.79, respectively (as compared with the current publicly reported model C statistic of 0.75); the risk-standardized mortality rates ranged from 10.7% to 19.0%, 10.7% to 19.1%, and 10.8% to 20.3%, respectively; the median risk-standardized mortality rate was 14.5% for all measures; and the odds of mortality for a high-mortality hospital (+1 SD) were 1.51, 1.52, and 1.52 times those for a low-mortality hospital (−1 SD), respectively.

Conclusions—

We developed 3 quality measures that demonstrate better discrimination than the Centers for Medicare & Medicaid Services’ existing stroke mortality measure, adjust for stroke severity, and could be implemented in a variety of settings.
Noise-Robust Modes of the Retinal Population Code Have the Geometry of “Ridges” and Correspond to Neuronal Communities
Authors: Loback Adrianna , Prentice Jason , Ioffe Mark , Berry II Michael
Published: September 2017

An appealing new principle for neural population codes is that correlations among neurons organize neural activity patterns into a discrete set of clusters, which can each be viewed as a noise-robust population codeword. Previous studies assumed that these codewords corresponded geometrically with local peaks in the probability landscape of neural population responses. Here, we analyze multiple data sets of the responses of approximately 150 retinal ganglion cells and show that local probability peaks are absent under broad, nonrepeated stimulus ensembles, which are characteristic of natural behavior. However, we find that neural activity still forms noise-robust clusters in this regime, albeit clusters with a different geometry. We start by defining a soft local maximum, which is a local probability maximum when constrained to a fixed spike count. Next, we show that soft local maxima are robustly present and can, moreover, be linked across different spike count levels in the probability landscape to form a ridge. We found that these ridges comprise combinations of spiking and silence in the neural population such that all of the spiking neurons are members of the same neuronal community, a notion from network theory. We argue that a neuronal community shares many of the properties of Donald Hebb's classic cell assembly and show that a simple, biologically plausible decoding algorithm can recognize the presence of a specific neuronal community.
Sparse Covariance Matrix Estimation by DCA-Based Algorithms
Authors: Phan Duy Nhat , Le Thi Hoai An , Dinh Tao Pham
Published: September 2017

This letter proposes a novel approach using the [Formula: see text]-norm regularization for the sparse covariance matrix estimation (SCME) problem. The objective function of SCME problem is composed of a nonconvex part and the [Formula: see text] term, which is discontinuous and difficult to tackle. Appropriate DC (difference of convex functions) approximations of [Formula: see text]-norm are used that result in approximation SCME problems that are still nonconvex. DC programming and DCA (DC algorithm), powerful tools in nonconvex programming framework, are investigated. Two DC formulations are proposed and corresponding DCA schemes developed. Two applications of the SCME problem that are considered are classification via sparse quadratic discriminant analysis and portfolio optimization. A careful empirical experiment is performed through simulated and real data sets to study the performance of the proposed algorithms. Numerical results showed their efficiency and their superiority compared with seven state-of-the-art methods.
Margin Error Bounds for Support Vector Machines on Reproducing Kernel Banach Spaces
Authors: Chen Liangzhi , Zhang Haizhang
Published: September 2017

Support vector machines, which maximize the margin from patterns to the separation hyperplane subject to correct classification, have received remarkable success in machine learning. Margin error bounds based on Hilbert spaces have been introduced in the literature to justify the strategy of maximizing the margin in SVM. Recently, there has been much interest in developing Banach space methods for machine learning. Large margin classification in Banach spaces is a focus of such attempts. In this letter we establish a margin error bound for the SVM on reproducing kernel Banach spaces, thus supplying statistical justification for large-margin classification in Banach spaces.
Effect of Morphologic Features of Neurons on the Extracellular Electric Potential: A Simulation Study Using Cable Theory and Electro-Quasi-Static Equations
Authors: Bestel R. , Appali R. , van Rienen U. , Thielemann C.
Published: September 2017

Microelectrode arrays serve as an indispensable tool in electro-physiological research to study the electrical activity of neural cells, enabling measurements of single cell as well as network communication analysis. Recent experimental studies have reported that the neuronal geometry has an influence on electrical signaling and extracellular recordings. However, the corresponding mechanisms are not yet fully understood and require further investigation. Allowing systematic parameter studies, computational modeling provides the opportunity to examine the underlying effects that influence extracellular potentials. In this letter, we present an in silico single cell model to analyze the effect of geometrical variability on the extracellular electric potentials. We describe finite element models of a single neuron with varying geometric complexity in three-dimensional space. The electric potential generation of the neuron is modeled using Hodgkin-Huxley equations. The signal propagation is described with electro-quasi-static equations, and results are compared with corresponding cable equation descriptions. Our results show that both the geometric dimensions and the distribution of ion channels of a neuron are critical factors that significantly influence both the amplitude and shape of extracellular potentials.
Dopamine, Inference, and Uncertainty
Authors: Gershman Samuel J.
Published: September 2017

The hypothesis that the phasic dopamine response reports a reward prediction error has become deeply entrenched. However, dopamine neurons exhibit several notable deviations from this hypothesis. A coherent explanation for these deviations can be obtained by analyzing the dopamine response in terms of Bayesian reinforcement learning. The key idea is that prediction errors are modulated by probabilistic beliefs about the relationship between cues and outcomes, updated through Bayesian inference. This account can explain dopamine responses to inferred value in sensory preconditioning, the effects of cue preexposure (latent inhibition), and adaptive coding of prediction errors when rewards vary across orders of magnitude. We further postulate that orbitofrontal cortex transforms the stimulus representation through recurrent dynamics, such that a simple error-driven learning rule operating on the transformed representation can implement the Bayesian reinforcement learning update.
What Does the Spirit Have to Do with Foreigners?
Authors: Estrada III Rodolfo Galvan
Published: September 2017

This article examines how Greco-Roman ethnoracial views inform our understanding of Peter and Cornelius’s encounter in Acts 10:28–48. By drawing from the Gentile perception of Jewish misanthropy mentioned by Diodorus of Sicily and Tacitus, we find that Peter was harboring a resistance to preach the gospel to the Caesareans. By rereading the narrative from this perspective, visions and Spirit baptism within Acts 10 become divine events that challenge the reluctance to preach the gospel and associate with foreigners.
osce Conflict Management in Central Asia
Authors: Dunay Pál
Published: September 2017

Conflicts and their management in Central Asia have never been prioritised by the osce although five states of the region are among its participating states. This has been due to that unlike in some other parts of the post-Soviet space most of the conflicts did not threaten with military escalation, and the intensity of strategic rivalry is less noticeable in this distant part of the osce area than closer to the heart of Europe. The fact Russia is not a direct party to the conflicts in Central Asia also reduces the interests of many participating states. There was one high intensity conflict in the region, the Tajik civil war that came too early for the osce. Lower intensity conflicts, ranging from border skirmishes, disputes about access to water, violation of rights of national minority groups, rigged elections are monitored and their resolutions are facilitated by the organisation. Some of them, like the 2010 Kyrgyz-Uzbek conflict had such short shelf-life internationally that no consensus-based inter-governmental organisation could have effectively intervened into it. The osce has been successful in conflict management when the party or parties also wanted to break the stale-mate that the Organization could facilitate. Domestic change in some Central Asian states is essential for advancing the osces cooperative security approach.
Ukraine Crisis and Mediation
Authors: Schläpfer Christian
Published: September 2017

This contribution examines mediation efforts undertaken by the Organization for Security and Cooperation in Europe (osce) in the context of the current crisis in and around Ukraine. It describes the establishment and evolution of the Trilateral Contact Group (tcg) and the mediated peace talks on the conflict in eastern Ukraine – the Minsk Process. Drawing from the author’s insider perspective, it sheds light on the unique aspects of the framework compared to classical mediation processes. It argues that, due to its connectivity with high-level diplomacy as well as its ability to adapt to a constantly evolving conflict, the Minsk Process represents a valuable, flexible, at times untypical, mediation framework.
A new Australian species of Eotetranychus (Acari: Tetranychidae) from buck spinifex Triodia mitchelli (Poaceae), intraspecific variation in Eotetranychus, and the synonymy of Platytetranychus with Eotetranychus
Authors: SEEMAN OWEN D. , BEARD JENNIFER J. , ZHANG LANNI
Published: September 2017

Eotetranychus spinophilus sp. nov. is described from adults and deutonymphs collected from the spinifex grass Triodia mitchelli (Poaceae) in Queensland, Australia. The species Eotetranychus sexmaculatus (Riley, 1890) is considered absent from Australia; all previous records are instead Eotetranychus queenslandicus Manson, 1967. A key to the six Australian species of Eotetranychus Oudemans, 1931 is provided. Although our new species is classified in Eotetranychus, it also resembles some species of Schizotetranychus Trägårdh, 1915. We reaffirm previous suggestions of polyphyly within Schizotetranychus and observed that the patterns of leg striae (e.g. longitudinal striae on tibiae and tarsi III–IV) may have taxonomic value within Schizotetranychus, but that such patterns are rarely included in descriptions of spider mites. We also discuss the relationships between Eotetranychus and the closely related genera Mononychellus Wainstein, 1971, Palmanychus Baker & Tuttle, 1972 and Platytetranychus Oudemans, 1931. We show that the type species of Platytetranychus, P. gibbosus Canestrini, 1889, is an incertae sedis taxon that is not a member of the Tetranychini, and for this and other reasons, we synonymise Platytetranychus with Eotetranychus.                                                                                                                          Leg setation is reported for all six Australian species and three European species of Eotetranychus. Although each species has a characteristic leg setation, variation is common, with 51% of specimens having at least one anomaly. Asymmetrical setal losses accounted for most variation (43% of specimens), but in five specimens (9%) the loss was symmetrical. Variation in the expression of setae was found mostly in setae added in the adult (21/27 variable setae), representing about two-thirds of the total 33 adult leg setae added in Eotetranychus. We therefore stress the need for multiple specimens when describing a new species, especially if species are being separated using differences in leg setation, and particularly those setae that are added in the adult life stage.
Fast and Slow Components of the Extratropical Atmospheric Circulation Response to CO2 Forcing
Authors: Ceppi Paulo , Zappa Giuseppe , Shepherd Theodore G. , Gregory Jonathan M.
Published: September 2017

Poleward shifts of the extratropical atmospheric circulation are a common response to CO2 forcing in global climate models (GCMs), but little is known about the time dependence of this response. Here it is shown that in coupled climate models, the long-term evolution of sea surface temperatures (SSTs) induces two distinct time scales of circulation response to steplike CO2 forcing. In most GCMs from phase 5 of the Coupled Model Intercomparison Project as well as in the multimodel mean, all of the poleward shift of the midlatitude jets and Hadley cell edge occurs in a fast response within 5–10 years of the forcing, during which less than half of the expected equilibrium warming is realized. Compared with this fast response, the slow response over subsequent decades to centuries features stronger polar amplification (especially in the Antarctic), enhanced warming in the Southern Ocean, an El Niño–like pattern of tropical Pacific warming, and weaker land–sea contrast. Atmosphere-only GCM experiments demonstrate that the SST evolution drives the difference between the fast and slow circulation responses, although the direct radiative effect of CO2 also contributes to the fast response. It is further shown that the fast and slow responses determine the long-term evolution of the circulation response to warming in the representative concentration pathway 4.5 (RCP4.5) scenario. The results imply that shifts in midlatitude circulation generally scale with the radiative forcing, rather than with global-mean temperature change. A corollary is that time slices taken from a transient simulation at a given level of warming will considerably overestimate the extratropical circulation response in a stabilized climate.
Darkode: Recruitment Patterns and Transactional Features of “the Most Dangerous Cybercrime Forum in the World”
Authors: Dupont Benoît , Côté Anne-Marie , Boutin Jean-Ian , Fernandez José
Published: September 2017

This article explores the social and market dynamics of Darkode, an invitation-only cybercrime forum that was dismantled by the FBI in July 2015 and was described by a U.S. Attorney as “the most sophisticated English-speaking forum for criminal computer hackers in the world.” Based on a leaked database of 4,788 discussion threads, we examine the selection process through which 344 potential new members introduced themselves to the community in order to be accepted into this exclusive group. Using a qualitative approach, we attempt to assess whether this rigorous procedure significantly enhanced the trust between traders, and therefore, contributed to the efficiency of this online illicit marketplace. We find that trust remained elusive and interactions were often fraught with suspicion and accusations. Even hackers who were considered successful faced significant challenges in trying to profit from the sale of malicious software and stolen data.
Awareness and use of electronic cigarettes: Perceptions of health science programme students in Malaysia
Authors: Goh Yin Hoong , Dujaili Juman Abdulelah , Blebil Ali Qais , Ahmed Syed Imran
Published: September 2017

Objectives:

In recent years, electronic nicotine delivery systems (ENDS) or e-cigarettes appear to be gaining in popularity despite controversy over their health effects and public health impacts. This paper is the first in Malaysia to assess sociodemographic and behavioural characteristics associated with ENDS awareness, perceptions and use among students enrolled in health science programmes.

Design:

Online self-reported use and perceptions of ENDS were assessed using a cross-sectional design.

Setting:

The study was conducted at the International Medical University, Malaysia.

Method:

An anonymous Internet-based, cross-sectional survey was conducted among a cohort of 404 undergraduate students at International Medical University, Malaysia, in September 2016. Data were collected over a period of 6 weeks. A 31-question web-based survey was developed to assess sociodemographic and behavioural characteristics associated with ENDS awareness, perceptions and use. Logistic regression analysis was performed to assess the impact of a set of predictors on e-cigarette use.

Results:

Almost 95% of respondents were aware of e-cigarettes, 13.8% reported ever-use and students had varied perceptions towards e-cigarettes. Characteristics associated with greater likelihood of ever-use included gender, ethnicity and parents educational level. Other correlates included prior conventional cigarette smoking, prior hookah smoking, parents’ tobacco use and higher sensation-seeking behaviour total score.

Conclusion:

In this sample of young adults, e-cigarette awareness was high and ever-use was evident especially among ever cigarette smokers. Nearly half of ever-users had not used an e-cigarette in the past 30 days of the survey and mostly reported flavoured over unflavoured e-cigarette use. These findings highlight the importance of e-cigarette surveillance and health promotion interventions targeting young adults.
Composite modular floor prototype for emergency housing applications: Experimental and analytical approach
Authors: Abdolpour Hassan , Garzón-Roca Julio , Escusa Gonçalo , Sena-Cruz José M , Barros Joaquim AO , Valente Isabel B
Published: September 2017

The present paper explores a new modular floor prototype to be used in emergency houses. The prototype is composed of a frame structure made of glass-fibre-reinforced polymer tubular pultruded profiles, a slab made of sandwich panels with a polyurethane foam core and glass-fibre-reinforced polymer skins, and a tailored connection system that provides integrity between assembled components. A series of experimental tests are carried out including flexural tests on a single panel, on two and three connected panels, and on the assembled floor prototype. The behaviour of the panels is analysed when they are not considered part of the glass-fibre-reinforced polymer framed structure, namely the failure mechanisms and the efficiency of the proposed connection system between the panels. The performance of the floor prototype to support typical load conditions of residential houses is also assessed. Additionally, an analytical model was used to deeper study the behaviour of the developed sandwich panels, connection system and the modular floor prototype.
Uncertainty quantification of fiber orientation distribution measurements for long-fiber-reinforced thermoplastic composites
Authors: Sharma Bhisham N , Naragani Diwakar , Nguyen Ba Nghiep , Tucker Charles L , Sangid Michael D
Published: September 2017

We present a detailed methodology for experimental measurement of fiber orientation distribution in injection-molded discontinuous fiber composites using the method of ellipses on two-dimensional cross sections. Best practices to avoid biases occurring during surface preparation and optical imaging of carbon-fiber-reinforced thermoplastics are discussed. A marker-based watershed transform routine for efficient image segmentation and the separation of touching fiber ellipses is developed. The sensitivity of the averaged orientation tensor to the image sample size is studied for the case of long-fiber thermoplastics. A Mori–Tanaka implementation of the Eshelby model is then employed to quantify the sensitivity of elastic stiffness predictions to biases in the fiber orientation distribution measurements.
No Exit: Social Reproduction in an Era of Rising Income Inequality
Authors: Flynn Lindsay B. , Schwartz Herman Mark
Published: September 2017

What explains the unexpected, uneven, but unquestionably pervasive trend toward re-familialization in the rich OECD countries? The usual arguments about political responses to rising income inequality, unstable families, and unstable employment predicted that the state would increasingly shelter people against risk, producing greater individuation and de- rather than re-familialization. By contrast, we argue three things. First, re-familialization has replaced de-familialization. Second, unequal access to housing drives a large part of re-familialization. Rather than becoming more “Anglo-Nordic,” countries are becoming more “southern European” in the way that younger cohorts access housing. Third, this inequality-driven insecurity and unequal access is felt differently not only between generational cohorts but also within cohorts.
Intensive Supervision Programs and Recidivism: How Michigan Successfully Targets High-Risk Offenders
Authors: DeVall Kristen E. , Lanier Christina , Hartmann David J. , Williamson Sarah Hupp , Askew LaQuana N.
Published: September 2017

The United States has witnessed enormous criminal justice system growth in the past 60 years. In response to calls for reform, several jurisdictions have implemented programs that provide intensive supervision for high-risk offenders, swiftly responding to violations with sanctions. This quasi-experimental study is the first comprehensive analysis of Michigan’s Swift and Sure Sanctions Probation Program (SSSPP), an alternative-to-incarceration program. The findings indicate that SSSPP participants had lower recidivism rates compared with individuals sentenced to probation-as-usual. Policy implications and suggestions for future research are offered.
A study of tubular braided structure with negative Poisson’s ratio behavior
Authors: Jiang Ning , Hu Hong
Published: September 2017

Textile structures with negative Poisson’s ratio (PR) behavior are called auxetic textile structures. They have received increasing attention in recent years and have been designed and fabricated through spinning, knitting, weaving and non-woven methods. However, auxetic textile structures fabricated using braiding method have not been reported so far. This paper reported a novel type of auxetic braided structure based on a helical structural arrangement. The geometry of the structure and its deformation mechanism were first introduced and described. Then a special manufacturing process was developed by the modification of commonly used tubular braiding technology. Various auxetic braids were fabricated with different structural parameters and yarns and tested under uniaxial extension conditions. The results showed that all manufactured braids exhibited high negative PR behavior and maintained this behavior until the fracture of the component wrap yarn. Among three structural parameters discussed, namely wrap angle, braiding angle and braiding yarn diameter, the wrap angle had more effects on the tensile properties of auxetic braided structure than the other two parameters. The success of fabricating auxetic braids with commercially available yarns in this study provides an alternative way to manufacture auxetics from positive PR materials.
Validation of the Basic Psychological Needs Scale in a South African student group
Authors: Cromhout Amanda , Schutte Lusilda , Wissing Marié P
Published: September 2017

The aim of this study was to validate the English version of the Basic Psychological Needs Scale with subscales Autonomy, Competence, and Relatedness in a South African student sample. The participants were a nonprobability sample of 322 students from a South African university. Confirmatory factor analysis was used to examine the scale’s factorial validity. Neither a one-factor nor a three-factor model fitted the original 21-item scale. After problematic items were removed, a 17-item Basic Psychological Needs Scale with a negatively worded method effect fitted the data best, but the fit was inadequate. Although the 17-item scale exhibited good convergent and discriminant validity, the internal consistency reliability remained low. The Basic Psychological Needs Scale had limited application in a South African student sample as a domain-general measure of basic psychological need satisfaction. Questions are raised regarding the extent to which the scale taps the construct under study in the current sample.
Interdependent Effects of Autonomous and Controlled Regulation on Exercise Behavior
Authors: Phillips L. Alison , Johnson Melissa A.
Published: September 2017

Self-determination theory (SDT) is used to predict individual differences in goal-directed behavior. A fundamental tenet of SDT is that autonomously regulated behavior is more likely to be engaged in and sustained than externally controlled behavior. Unidimensional treatment of regulation is suboptimal. The current study utilizes a multidimensional approach—polynomial regression—to evaluate the interdependent effects of autonomous and controlled regulation on physical activity. Results from three samples of healthy, younger adults demonstrate a mostly positive influence of autonomous regulation but a curvilinear effect of controlled regulation on behavior such that greater activity was associated with moderate levels of controlled regulation—an effect that cannot be identified with “unidimensional” methods. Results from Sample 3 showed that autonomous regulation was associated with greater exercise levels only when controlled regulation was moderate or high. Results suggest that controlled regulation is not wholly detrimental to behavioral promotion.
Sharing Extraordinary Experiences Fosters Feelings of Closeness
Authors: Min Kate E. , Liu Peggy J. , Kim Soo
Published: September 2017

Every social relationship begins somewhere. Yet, little is known about which initial encounters bring people closer. This article investigates whether feelings of closeness are shaped by the type of experience shared between two individuals. Using different procedures and stimuli, we find that one determining factor is whether unacquainted individuals initially share a relatively more ordinary or extraordinary experience: more extraordinary (vs. ordinary) experiences facilitate greater closeness between unacquainted individuals (Studies 1a-1c). We also find that this closeness-fostering effect does not occur for interactions between well-acquainted individuals (Study 2), when there is presumably little discomfort associated with the interaction. Furthermore, this effect appears to be driven by more extraordinary experiences’ capacity to absorb individuals’ attention (Study 3). Thus, we suggest that extraordinary experiences foster feelings of closeness because they direct unacquainted individuals’ attention toward the extraordinariness of the experience and away from the discomfort of initial interactions.
The Information Product Methods: A Unified Approach to Dual-Purpose Computerized Adaptive Testing
Authors: Zheng Chanjin , He Guanrui , Gao Chunlei
Published: September 2017

This article gives a brief summary of major approaches in dual-purpose computerized adaptive testing (CAT) in which the test is tailored interactively to both an examinee’s overall ability level, [Formula: see text], and attribute mastery level, [Formula: see text]. It also proposes an information product approach whose connections to the current methods are revealed. An updated comprehensive empirical study demonstrated that the information product approach not only can offer a unified framework to connect all other approaches but also can mitigate the weighting issue in the dual-information approach.
A validation study of the Caregiver Mastery Scale for partners of patients with acquired brain injury
Authors: Cox Vincent CM , Schepers Vera PM , Ketelaar Marjolijn , Kruithof Willeke J , van Heugten Caroline M , Visser-Meily Johanna MA
Published: September 2017

Objective:

To validate the Caregiver Mastery Scale for partners of patients with acquired brain injury.

Design:

The score distributions, internal consistency and convergent validity of the Caregiver Mastery Scale were determined.

Subjects:

A total of 92 partners (53% male, age 62 years) of patients with acquired brain injury (91% stroke) discharged from inpatient rehabilitation (time since injury 32 months).

Main measures:

Outcome measure: Caregiver Mastery Scale. Reference measures: Caregiver Strain Index, Hospital Anxiety and Depression Scale and CarerQoL.

Results:

The Caregiver Mastery Scale has a normal distribution, with no floor or ceiling effects. Its internal consistency is acceptable (Cronbach’s alpha: 0.75). The convergent validity analyses confirmed our hypothesis that higher scores on the Caregiver Mastery Scale correlate with less burden, lower levels of anxiety and depression and greater well-being. Furthermore, partners scoring high on the Caregiver Mastery Scale mostly scored below the clinical cut-off scores on the Caregiver Strain Index and the anxiety and depression subscales of the Hospital Anxiety and Depression Scale, whereas partners scoring low on the Caregiver Mastery Scale were more likely to score above the cut-off points.

Conclusion:

The Caregiver Mastery Scale is a valid instrument to assess the caregiver mastery of partners of patients with acquired brain injury.
The Dorsal Medial Habenula Minimally Impacts Circadian Regulation of Locomotor Activity and Sleep
Authors: Hsu Yun-Wei A. , Gile Jennifer J. , Perez Jazmine G. , Morton Glenn , Ben-Hamo Miriam , Turner Eric E. , de la Iglesia Horacio O.
Published: September 2017

In nocturnal rodents, voluntary wheel-running activity (WRA) represents a self-reinforcing behavior. We have previously demonstrated that WRA is markedly reduced in mice with a region-specific deletion of the transcription factor Pou4f1 (Brn3a), which leads to an ablation of the dorsal medial habenula (dMHb). The decrease in WRA in these dMHb-lesioned (dMHbCKO) mice suggests that the dMHb constitutes a critical center for conveying reinforcement by exercise. However, WRA also represents a prominent output of the circadian system, and the possibility remains that the dMHb is a source of input to the master circadian pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus. To test this hypothesis, we assessed the integrity of the circadian system in dMHbCKO mice. Here we show that the developmental lesion of the dMHb reduces WRA under both a light-dark cycle and constant darkness, increases the circadian period of WRA, but has no effect on the circadian amplitude or period of home cage activity or the daily amplitude of sleep stages, suggesting that the lengthening of period is a result of the decreased WRA in the mutant mice. Polysomnographic sleep recordings show that dMHbCKO mice have an overall unaltered daily amplitude of sleep stages but have fragmented sleep and an overall increase in total rapid eye movement (REM) sleep. Photoresponsiveness is intact in dMHbCKO mice, but compared with control animals, they reentrain faster to a 6-h abrupt phase delay protocol. Circadian changes in WRA of dMHbCKO mice do not appear to emerge within the central pacemaker, as circadian expression of the clock genes Per1 and Per2 within the SCN is normal. We do find some evidence for fragmented sleep and an overall increase in total REM sleep, supporting a model in which the dMHb is part of the neural circuitry encoding motivation and involved in the manifestation of some of the symptoms of depression.
A Model-Based Approach to Optimizing Ultradian Forced Desynchrony Protocols for Human Circadian Research
Authors: Stack Nora , Barker David , Carskadon Mary , Diniz Behn Cecilia
Published: September 2017

The human circadian system regulates internal 24-h rhythmicity and plays an important role in many aspects of human health and behavior. To investigate properties of the human circadian pacemaker such as intrinsic period and light sensitivity, experimental researchers have developed forced desynchrony (FD) protocols in which manipulations of the light-dark (LD) cycle are used to desynchronize the intrinsic circadian rhythm from the rest-activity cycle. FD protocols have typically been based on exposure to long LD cycles, but recently, ultradian FD protocols with short LD cycles have been proposed as a new methodology for assessing intrinsic circadian period. However, the effects of ultradian FD protocol design, including light intensity or study duration, on estimates of intrinsic circadian period have not, to our knowledge, been systematically studied. To address this gap, we applied a light-sensitive, dynamic mathematical model of the human circadian pacemaker to simulate ultradian FD protocols and analyze the effects of protocol design on estimates of intrinsic circadian period. We found that optimal estimates were obtained using protocols with low light intensities, at least 10 d of exposure to ultradian cycling, and a 7-h LD cycle duration that facilitated uniform light exposure across all circadian phases. Our results establish a theoretical framework for ultradian FD protocols that can be used to provide insights into data obtained under existing protocols and to optimize protocols for future experiments.
Radical Visions, Structural Constraints
Authors: Boucher Lisa
Published: September 2017

Based on a qualitative study of two feminist organizations located in Ontario, Canada, this article considers the tensions that state-funded organizations must negotiate in their efforts to engage in anti-oppressive (AO) practice. The rise of neoliberalism and neoconservatism in Canada has produced a political climate that threatens feminist organizations’ social justice mandates. This climate undermines feminist organizations’ efforts to advocate for their communities, to create inclusive organizations, and to provide compassionate service informed by AO principles. However, to argue that feminist service organizations are depoliticized through their relationship with state funding agencies simplifies the complexity of state-social movement relations. This article illustrates the contradictory influence state funding has on AO practice in feminist organizations and examines the ways organizations navigate challenges presented by their political climate. Despite the structural constraints facing AO practice in feminist organizations, I argue that AO frameworks can provide organizations with a renewed focus on their social justice mandates.
Antisocial Personality Disorder in Older Adults: A Critical Review
Authors: Holzer Katherine J. , Vaughn Michael G.
Published: September 2017

Antisocial personality disorder (ASPD) has enormous negative impacts on the affected individuals, their loved ones, and society. This burden is intensified by the social and functional changes related to age. The lower prevalence of ASPD in older adults compared to younger adults is well-documented. This discrepancy, often attributed solely to antisocial “burnout,” contributes to the lack of attention given to this disorder in older adults and may signify difficulty measuring ASPD in this population. These measurement issues likely stem from problems with the validity of the diagnostic criteria for older adults which may not effectively capture changes that occur with age. This review focuses on the current literature surrounding the validity of ASPD criteria with older adults and relevant concepts, including the connection between criminality and ASPD. Issues with screening tools and the measurement of ASPD caused by problems with the criteria are also discussed. Finally, recommendations for improvement, including use of dimensional models of personality disorders, a potential geriatric subclassification of criteria, and modification of the existing criteria are presented with clinical implications and suggestions for future research.
Impact of Latin Dance on Physical Activity, Cardiorespiratory Fitness, and Sedentary Behavior Among Latinos Attending an Adult Day Center
Authors: Aguiñaga Susan , Marquez David X.
Published: September 2017

Objective: The aim of this study was to determine whether a Latin dance program with sedentary behavior information would have an impact on physical activity, cardiorespiratory fitness (CRF), and sedentary behavior among older Latinos attending an adult day center (ADC). Method: Participants ( N = 21, 75.4 ± 6.3 years old, Mini-Mental State Examination [MMSE] score = 22.4 ± 2.8) were randomized into a dance or wait-list control group. Participants wore an accelerometer and inclinometer and completed a sedentary behavior questionnaire, and a nonexercise equation was used to calculate CRF. Results: Findings indicate small to medium effect sizes in the desired direction during midpoint of the intervention for physical activity, sedentary behavior–related outcomes, CRF, and self-reported sedentary behavior in the dance group; however; dance participants did not maintain that trajectory for the remaining 2 months of the intervention. Discussion: Future studies may consider implementing behavioral strategies during midpoint of the intervention to encourage participants attending an ADC to maintain physical activity and sedentary behavior changes.
Childhood Disadvantage, Psychosocial Resiliency, and Later Life Functioning: Linking Early-Life Circumstances to Recovery From Mobility Limitation
Authors: Latham-Mintus Kenzie , Aman Katelyn M.
Published: September 2017

Objective: There is limited knowledge about whether childhood disadvantage, defined as economic and health disadvantage, influences recovery from functional impairment. Method: Using data from the Health and Retirement Study (2008-2010), this research explores whether childhood disadvantage shapes recovery from mobility limitation. In addition, this research examines whether measures of psychosocial resiliency such as mastery, optimism, and religiosity moderate the relationship between childhood disadvantage and recovery. Results: Childhood disadvantage appeared to shape recovery from mobility limitation in later life. Greater number of chronic childhood conditions and low maternal education decreased the odds of recovery. Mastery was a robust predictor of recovery and also a moderator of childhood disadvantage (i.e., moving for financial reasons) and recovery. Discussion: Findings suggest that mastery may be able to diminish the negative effects of financial hardship in childhood on recovery outcomes in later life.
Driveline instability of racing motorcycles in straight braking manoeuvre
Authors: Leonelli Luca , Cattabriga Stefano , Sorrentino Silvio
Published: September 2017

Experimental evidence shows that a self-excited vibration may appear during braking manoeuvres performed by road-racing motorcycles. It involves vertical oscillation of front and rear wheel axles as well as angular oscillation of the driveline in a frequency range between 17 and 22 Hz. As a consequence, severe oscillations of the tyre-ground vertical loads can be observed, leading to a loss of grip and ultimately weakening the vehicle overall performance. Several contributions on this topic can be accounted for in the literature; however, a comprehensive description of the phenomenon has not been given yet. The present work is aimed at simulating the above vibration with a planar multibody motorcycle model, and then at analyzing its driving mechanism. Stability maps are drawn for time-invariant braking manoeuvres, and validated with respect to time domain simulations.
Reprioritization of Features of Multidimensional Objects Stored in Visual Working Memory
Authors: Park Young Eun , Sy Jocelyn L. , Hong Sang Wook , Tong Frank
Published: September 2017

A prevalent view of visual working memory (VWM) is that visual information is actively maintained in the form of perceptually integrated objects. Such reliance on object-based representations would predict that after an object is fully encoded into VWM, all features of that object would need to be maintained as a coherent unit. Here, we evaluated this idea by testing whether memory resources can be redeployed to a specific feature of an object already stored in VWM. We found that observers can utilize a retrospective cue presented during the maintenance period to attenuate both the gradual deterioration and complete loss of memory for a cued feature over time, but at the cost of accelerated loss of information regarding the uncued feature. Our findings demonstrate that object representations held within VWM can be decomposed into individual features and that having to retain additional features imposes greater demands on active maintenance processes.
Joint modeling of longitudinal and survival data with a covariate subject to a limit of detection
Authors: Sattar Abdus , Sinha Sanjoy K
Published: September 2017

We develop and study an innovative method for jointly modeling longitudinal response and time-to-event data with a covariate subject to a limit of detection. The joint model assumes a latent process based on random effects to describe the association between longitudinal and time-to-event data. We study the role of the association parameter on the regression parameters estimators. We model the longitudinal and survival outcomes using linear mixed-effects and Weibull frailty models, respectively. Because of the limit of detection, missing covariate (explanatory variable, x) values may lead to the non-ignorable missing, resulting in biased parameter estimates with poor coverage probabilities of the confidence interval. We define and estimate the probability of missing due to the limit of detection. Then we develop a novel joint density and hence the likelihood function that incorporates the effect of left-censored covariate. Monte Carlo simulations show that the estimators of the proposed method are approximately unbiased and provide expected coverage probabilities for both longitudinal and survival submodels parameters. We also present an application of the proposed method using a large clinical dataset of pneumonia patients obtained from the Genetic and Inflammatory Markers of Sepsis study.
Sample size considerations for paired experimental design with incomplete observations of continuous outcomes
Authors: Zhu Hong , Xu Xiaohan , Ahn Chul
Published: September 2017

Paired experimental design is widely used in clinical and health behavioral studies, where each study unit contributes a pair of observations. Investigators often encounter incomplete observations of paired outcomes in the data collected. Some study units contribute complete pairs of observations, while the others contribute either pre- or post-intervention observations. Statistical inference for paired experimental design with incomplete observations of continuous outcomes has been extensively studied in literature. However, sample size method for such study design is sparsely available. We derive a closed-form sample size formula based on the generalized estimating equation approach by treating the incomplete observations as missing data in a linear model. The proposed method properly accounts for the impact of mixed structure of observed data: a combination of paired and unpaired outcomes. The sample size formula is flexible to accommodate different missing patterns, magnitude of missingness, and correlation parameter values. We demonstrate that under complete observations, the proposed generalized estimating equation sample size estimate is the same as that based on the paired t-test. In the presence of missing data, the proposed method would lead to a more accurate sample size estimate comparing with the crude adjustment. Simulation studies are conducted to evaluate the finite-sample performance of the generalized estimating equation sample size formula. A real application example is presented for illustration.