Sex differences in patterns of white matter neuroplasticity after balance training in young adults.

Introduction: In past work we demonstrated different patterns of white matter (WM) plasticity in females versus males associated with learning a lab-based unilateral motor skill. However, this work was completed in neurologically intact older adults. The current manuscript sought to replicate and expand upon these WM findings in two ways: (1) we investigated biological sex differences in neurologically intact young adults, and (2) participants learned a dynamic full-body balance task. Methods: 24 participants (14 female, 10 male) participated in the balance training intervention, and 28 were matched controls (16 female, 12 male). Correlational tractography was used to analyze changes in WM from pre- to post-training. Results: Both females and males demonstrated skill acquisition, yet there were significant differences in measures of WM between females and males. These data support a growing body of evidence suggesting that females exhibit increased WM neuroplasticity changes relative to males despite comparable changes in motor behavior (e.g., balance). Discussion: The biological sex differences reported here may represent an important factor to consider in both basic research (e.g., collapsing across females and males) as well as future clinical studies of neuroplasticity associated with motor function (e.g., tailored rehabilitation approaches).

Brain vital signs as a quantitative measure of cognition: Methodological implementation in a care home environment.

Introduction: Managing cognitive function in care homes is a significant challenge. Individuals in care have a variety of scores across standard clinical assessments, such as the Mini-Mental Status Exam (MMSE), and many of them have scores that fall within the range associated with dementia. A recent methodological advance, brain vital sign monitoring through auditory event-related potentials, provides an objective and sensitive physiological measurement to track abnormalities, differences, or changes in cognitive function. Taking advantage of point-of-care accessibility, the current study evaluated the methodological feasibility, the assessment of whether a particular research method can be successfully implemented, of quantitatively measuring cognition of care home residents using brain vital signs. Secondarily, the current study examined the relationship between brain vital signs, specifically the cognitive processing associated N400 component, and MMSE scores in care home residents. Materials and methods: Brain vital signs used the established N100 (auditory sensation), P300 (basic attention), and N400 (cognitive processing) event-related potential (ERP) components. A total of 52 residents were enrolled, with all participants evaluated using the MMSE. Participants were assigned into homogeneous groups based on their MMSE scores, and were categorized into low (n = 14), medium (n = 17), and high (n = 13) MMSE groups. Both brain vital sign measures and underlying ERP waveforms were examined. Statistical analyses used partial least squares correlation (PLS) analyses in which both MMSE and age were included as factors, as well as jackknife approaches, to test for significant brain vital sign changes. Results: The current study successfully measured and analyzed standardized, quantifiable brain vital signs in a care home setting. ERP waveform data showed specific N400 changes between MMSE groups as a function of MMSE score. PLS analyses confirmed significant MMSE-related and age-related differences in the N400 amplitude (p < 0.05, corrected). Similarly, the jackknife approach emphasized the N400 latency difference between the low and high MMSE groups. Discussion and conclusion: It was possible to acquire brain vital signs measures in care home residents. Additionally, the current study evaluated brain vital signs relative to MMSE in this group. The comparison revealed significant decreasing in N400 response amplitude (cognitive processing) as a function of both MMSE score and age, as well as a slowing of N400 latency. The findings indicate that objective neurophysiological measures of impairment are detectable in care home residents across the span of MMSE scores. Direct comparison to MMSE- and age-related variables represents a critical initial step ahead of future studies that will investigate relative improvements in sensitivity, validity, reliability and related advantages of brain vital sign monitoring.

Investigating female versus male differences in white matter neuroplasticity associated with complex visuo-motor learning.

Magnetic resonance imaging (MRI) has increasingly been used to characterize structure-function relationships during white matter neuroplasticity. Biological sex differences may be an important factor that affects patterns of neuroplasticity, and therefore impacts learning and rehabilitation. The current study examined a participant cohort before and after visuo-motor training to characterize sex differences in microstructural measures. The participants (N = 27) completed a 10-session (4 week) complex visuo-motor training task with their non-dominant hand. All participants significantly improved movement speed and their movement speed variability over the training period. White matter neuroplasticity in females and males was examined using fractional anisotropy (FA) and myelin water fraction (MWF) along the cortico-spinal tract (CST) and the corpus callosum (CC). FA values showed significant differences in the middle portion of the CST tract (nodes 38-51) across the training period. MWF showed a similar cluster in the inferior portion of the tract (nodes 18-29) but did not reach significance. Additionally, at baseline, males showed significantly higher levels of MWF measures in the middle body of the CC. Combining data from females and males would have resulted in reduced sensitivity, making it harder to detect differences in neuroplasticity. These findings offer initial insights into possible female versus male differences in white matter neuroplasticity during motor learning. This warrants investigations into specific patterns of white matter neuroplasticity for females versus males across the lifespan. Understanding biological sex-specific differences in white matter neuroplasticity may have significant implications for the interpretation of change associated with learning or rehabilitation.

Dominance Analysis of Bright and Dark Dispositional Predictors of Socially Desirable Responding.

Although the role of so-called dark traits in the prediction of maladaptive behavior has seen a large increase in interest by researchers, the Big Five still maintain their ubiquity in the prediction of most behaviors. This study uses measures of the Dark Tetrad and the Big Five personality traits to predict a very specific form of maladaptive behavior: the impression management form of socially desirable responding. In regression-based dominance analysis, results suggest that not all of the Big Five nor the Dark Tetrad provide statistically significant incremental validity but as a block, the Big Five dominate the Dark Tetrad in the prediction of the purposeful misrepresentation of one's self to others on self-report inventories. More specifically, four of the Big Five as well as the traits of Machiavellianism and sadism from the Dark Tetrad are significant predictors of impression management.

Rock properties and sediment caliber govern bedrock river morphology across the Taiwan Central Range.

Feedbacks between surface and deep Earth processes in collisional mountain belts depend on how erosion and topographic relief vary in space and time. One outstanding unknown lies in how rock strength influences bedrock river morphology and thus mountain relief. Here, we quantify boulder cover and channel morphology using uncrewed aerial vehicle surveys along 30 kilometers of bedrock-bound river corridors throughout the Taiwan Central Range where regional gradients in rock properties relate to tectonic history. We find that boulder size systematically increases with increasing metamorphic grade and depth of exhumation. Boulder size correlates with reach-scale channel steepness but does not explain observations of highly variable channel width. Transport thresholds indicate that rivers are adjusted to mobilize boulders and are well in excess of the threshold to transport gravel and cobbles, as previously assumed. The linkage between metamorphic history, boulder size, and channel steepness reveals how rock properties can influence feedbacks between tectonics and topography throughout the life span of a mountain range.

Females exhibit smaller volumes of brain activation and lower inter-subject variability during motor tasks.

Past work has shown that brain structure and function differ between females and males. Males have larger cortical and sub-cortical volume and surface area (both total and subregional), while females have greater cortical thickness in most brain regions. Functional differences are also reported in the literature, yet to date little work has systematically considered whether patterns of brain activity indexed with functional magnetic resonance imaging (fMRI) differ between females and males. The current study sought to remediate this issue by employing task-based whole brain motor mapping analyses using an openly available dataset. We tested differences in patterns of functional brain activity associated with 12 voluntary movement patterns in females versus males. Results suggest that females exhibited smaller volumes of brain activation across all 12 movement tasks, and lower patterns of variability in 10 of the 12 movements. We also observed that females had greater cortical thickness, which is in alignment with previous analyses of structural differences. Overall, these findings provide a basis for considering biological sex in future fMRI research and provide a foundation of understanding differences in how neurological pathologies present in females vs males.

Accelerated Miocene incision along the Yangtze River driven by headward drainage basin expansion.

Along the southeastern margin of the Tibetan Plateau, the onset of rapid fluvial incision during the Miocene is commonly attributed to growth of high topography. Recent recognition of lacustrine strata preserved atop interfluves, however, suggest that headward expansion of river networks drove migration of the topographic divide. Here, we explore the impact of this process on fluvial incision along the Yangtze River. Landscape evolution simulations demonstrate that expansion of the Yangtze watershed since the Late Miocene could be responsible for 1 to 2 kilometers of fluvial incision. The distribution of modern knickpoints and river profiles is consistent with this hypothesis. We suggest that increased erosive power associated with capture and basin integration drove accelerated incision during the Late Miocene. Our results imply that eastern Tibet was elevated before middle Cenozoic time and that the tempo of fluvial incision may be out of phase with uplift of plateau topography.

Real world evidence of improved attention and cognition during physical therapy paired with neuromodulation: a brain vital signs study.

Background: Non-invasive neuromodulation using translingual neurostimulation (TLNS) has been shown to advance rehabilitation outcomes, particularly when paired with physical therapy (PT). Together with motor gains, patient-reported observations of incidental improvements in cognitive function have been noted. Both studies in healthy individuals and case reports in clinical populations have linked TLNS to improvements in attention-related cognitive processes. We investigated if the use of combined TLNS/PT would translate to changes in objective neurophysiological cognitive measures in a real-world clinical sample of patients from two separate rehabilitation clinics. Methods: Brain vital signs were derived from event-related potentials (ERPs), specifically auditory sensation (N100), basic attention (P300), and cognitive processing (N400). Additional analyses explored the attention-related N200 response given prior evidence of attention effects from TLNS/PT. The real-world patient sample included a diverse clinical group spanning from mild-to-moderate traumatic brain injury (TBI), stroke, Multiple Sclerosis (MS), Parkinson's Disease (PD), and other neurological conditions. Patient data were also acquired from a standard clinical measure of cognition for comparison. Results: Results showed significant N100 variation between baseline and endpoint following TLNS/PT treatment, with further examination showing condition-specific significant improvements in attention processing (i.e., N100 and N200). Additionally, CogBAT composite scores increased significantly from baseline to endpoint. Discussion: The current study highlighted real-world neuromodulation improvements in neurophysiological correlates of attention. Overall, the real-world findings support the concept of neuromodulation-related improvements extending beyond physical therapy to include potential attention benefits for cognitive rehabilitation.

Increased myelination plays a central role in white matter neuroplasticity.

White matter (WM) neuroplasticity in the human brain has been tracked non-invasively using advanced magnetic resonance imaging techniques, with increasing evidence for improved axonal transmission efficiency as a central mechanism. The current study is the culmination of a series of studies, which characterized the structure-function relationship of WM transmission efficiency in the cortico-spinal tract (CST) during motor learning. Here, we test the hypothesis that increased transmission efficiency is linked directly to increased myelination using myelin water imaging (MWI). MWI was used to evaluate neuroplasticity-related improvements in the CST. The MWI findings were then compared to diffusion tensor imaging (DTI) results, with the secondary hypothesis that radial diffusivity (RD) would have a stronger relationship than axial diffusivity (AD) if the changes were due to increased myelination. Both MWI and RD data showed the predicted pattern of significant results, strongly supporting that increased myelination plays a central role in WM neuroplasticity.

Existence of a continental-scale river system in eastern Tibet during the late Cretaceous-early Palaeogene.

The establishment of continental-scale drainage systems on Earth is largely controlled by topography related to plate boundary deformation and buoyant mantle. Drainage patterns of the great rivers in Asia are thought to be highly dynamic during the Cenozoic collision of India and Eurasia, but the drainage pattern and landscape evolution prior to the development of high topography in eastern Tibet remain largely unknown. Here we report the results of petro-stratigraphy, heavy-mineral analysis, and detrital zircon U-Pb dating from late Cretaceous-early Palaeogene sedimentary basin strata along the present-day eastern margin of the Tibetan Plateau. Similarities in the provenance signatures among basins indicate that a continental-scale fluvial system once drained southward into the Neo-Tethyan Ocean. These results challenge existing models of drainage networks that flowed toward the East Asian marginal seas and require revisions to inference of palaeo-topography during the Late Cretaceous. The presence of a continent-scale river may have provided a stable long-term base level which, in turn, facilitated the development of an extensive low-relief landscape that is preserved atop interfluves above the deeply incised canyons of eastern Tibet.

A retrospective analysis of the number of therapy visits after distal radius fractures using a new provider-scored clinical severity scale.

STUDY DESIGN: Retrospective study. INTRODUCTION: Fractures of the distal radius are common as is a postfracture referral to occupational therapy (OT). This article examines factors that cause greater morbidity and a greater number of OT visits. PURPOSE OF THE STUDY: This study aims to analyze which of 5 common sequelae of the distal radius fracture is most significant for increasing the number of therapy visits. METHODS: Three-hundred Sixty charts were reviewed, and 89 were selected. Multiple regression was used to determine which of our 5 independent variables had the greatest predictive power for the total number of therapy visits. RESULTS: The regression model demonstrated significance at P ≤ .01. Total active motion (TAM) of the digits (P ≤ .01) and TAM of the forearm (P ≤ .01) were the only complications that demonstrated statistical significance and a positive relationship with the number of therapy visits. In addition to this, TAM of the forearm and digits showed a strong correlation with the number of therapy visits. TAM of the wrist, pain, and edema had a weak correlation. Patients with high total group score on the clinical severity scale also had a moderate correlation. DISCUSSION: The results of the study illustrate the importance of digital contractures on a patient's morbidity, function, and their need for OT visits. CONCLUSION: The information from this study is important for the clinician as it identifies patients at risk for increased morbidity and identifies the complications that the clinician may want to stress early in the rehabilitation of that patient. LEVEL OF EVIDENCE: 3.

Expansion of the Tibetan Plateau during the Neogene.

The appearance of detritus shed from mountain ranges along the northern margin of the Tibetan Plateau heralds the Cenozoic development of high topography. Current estimates of the age of the basal conglomerate in the Qaidam basin place this event in Paleocene-Eocene. Here we present new magnetostratigraphy and mammalian biostratigraphy that refine the onset of basin fill to ∼25.5 Myr and reveal that sediment accumulated continuously until ∼4.8 Myr. Sediment provenance implies a sustained source in the East Kunlun Shan throughout this time period. However, the appearance of detritus from the Qilian Shan at ∼12 Myr suggests emergence of topography north of the Qaidam occurred during the late Miocene. Our results imply that deformation and mountain building significantly post-date Indo-Asian collision and challenge the suggestion that the extent of the plateau has remained constant through time. Rather, our results require expansion of high topography during the past 25 Myr.

Strategic groups and outcomes in the US hospice care industry.

PURPOSE: As a result of a drastic increase in new patients, two major shifts are occurring in the US hospice care industry: an increase in the number of for-profit providers, and hospices are increasing in size through acquisitions and mergers. Hospices are trying to both increase the number of innovative programs they offer and decrease their operating expenses to improve their margins and attract more patients. This study seeks to investigate if strategic groups exist within the industry as hospices try to become more innovative and efficient, which grouping factors are most significant, and to determine whether there is a relationship between group membership and performance. DESIGN/METHODOLOGY/APPROACH: Cluster analysis and ANOVA are used to analyze data from 93 California hospices. FINDINGS: Three strategic groups exist within the market, innovative practices significantly affect group membership, and innovation-oriented groups outperform others in terms of quality of care. PRACTICAL IMPLICATIONS: Many hospices focus on innovation, and evidence suggests that continued pursuit of innovative practices is critical, whereas efficiency does not appear to have a significant impact on quality of care. Focus on such evidence-based practices is important for long-term success. ORIGINALITY/VALUE: This is the first study to investigate strategic group formation in the hospice care industry.

Stress changes from the 2008 Wenchuan earthquake and increased hazard in the Sichuan basin.

On 12 May 2008, the devastating magnitude 7.9 (Wenchuan) earthquake struck the eastern edge of the Tibetan plateau, collapsing buildings and killing thousands in major cities aligned along the western Sichuan basin in China. After such a large-magnitude earthquake, rearrangement of stresses in the crust commonly leads to subsequent damaging earthquakes. The mainshock of the 12 May earthquake ruptured with as much as 9 m of slip along the boundary between the Longmen Shan and Sichuan basin, and demonstrated the complex strike-slip and thrust motion that characterizes the region. The Sichuan basin and surroundings are also crossed by other active strike-slip and thrust faults. Here we present calculations of the coseismic stress changes that resulted from the 12 May event using models of those faults, and show that many indicate significant stress increases. Rapid mapping of such stress changes can help to locate fault sections with relatively higher odds of producing large aftershocks.

A study of the effects of innovative and efficient practices on the performance of hospice care organizations.

BACKGROUND: Due to changes in social norms, funding initiatives, and other environmental factors, the business of hospice care has significantly evolved over the past 40 years. There has been an influx of for-profit firms, increased consolidation, and significant funding changes. We have witnessed a growth in utilization rates, an increase in insurance coverage, and improved governmental funding. Hospice care organizations have responded to these pressures by pursuing more efficient and innovative business practices. PURPOSE: Drawing upon institutional theory, this study seeks to address whether quality of care provided to hospice patients is affected as organizations respond to environmental pressures for innovative and efficient business practices. METHODOLOGY/APPROACH: This study uses hierarchical regression to analyze data from 111 hospices in California. FINDINGS: Innovative practices are positively related to quality of care. However, efficient practices have no significant relationship with quality of care. PRACTICAL IMPLICATIONS: It appears that incorporating innovative practices is positively related to quality of care. Although cost containment may be necessary for continued survival, efficiency improvement efforts do not seem to lead to improved quality of care.

The impact of competition on the importance of conforming to social norms: strategies for managed care organizations.

PURPOSE: This study focuses around the central question of whether or not the relative importance of conformity to institutional norms varies as markets become more competitive. DESIGN/METHODOLOGY/APPROACH: Using data gathered for 187 managed health care plans in the U.S., this study uses hierarchical regression analysis involving blocked variables. FINDINGS: This study finds that conformity to technical environmental requirements has a significant impact on performance at all levels of competition. However, the importance of conformity to institutional norms increases as markets becomes more competitive. PRACTICAL IMPLICATIONS: From the perspective of MCOs, this means that managers need to carefully monitor the prevailing technical and institutional environmental forces and match their responses according to the competitiveness of their individual markets. From a societal perspective, this study suggests that improved health care delivery is likely to result from increased competition in the managed care market. ORIGINALITY/VALUE: Prior research has shown that conformity to social norms is important for MCO performance. However, this is the first study to examine the whether the importance of conformity to social norms varies as a function of market competition.

A comparative analysis of stakeholder power in the Mexican and U.S. health care systems.

The primary focus of this paper is to analyze the Mexican health care system and the forces driving its change. To facilitate this, the paper conducts an analysis of the key stakeholders in both the U.S. and Mexican health care systems. The Mexican system is dominated by an autocratic federal government that is gradually relinquishing its role as provider of health care in exchange for control of the reform efforts. The U.S. system is characterized by a relatively equal distribution of power among the key stakeholders, in which changes occur primarily through incrementalism. The results of the analysis indicate that the key differences lie in terms of relative stakeholder power and rate of change in the systems. Compared with the U.S.,Mexico is making rapid changes to its health care system and both countries are struggling with the same key issues: Cost, access, and quality.