bluuebunny/crossref_metadata_2025 huggingface dataset:
Revealing the dual streams of speech processing
Authors: Fridriksson Julius , Yourganov Grigori , Bonilha Leonardo , Basilakos Alexandra , Den Ouden Dirk-Bart , Rorden Christopher
Published: December 2016

Significance

Relatively recently, the concept of dual route neural architecture, where dorsal and ventral brain regions process information synergistically, has been applied to study of speech processing. Although a large body of work has investigated these streams in relation to human speech processing, there is little consensus regarding specific cortical regions implicated. Relying on extensive behavioral and neuroimaging data from a large sample of stroke survivors, we used a data-driven approach to localize regions crucial for motor–phonological and lexical–semantic aspects of speech processing. Results revealed distinct anatomical boundaries between a dorsal frontoparietal stream supporting a form-to-articulation pathway and a ventral temporal–frontal stream supporting a form-to-meaning pathway. This study shows clear division between two processing routes underlying human speech.
Histone deacetylases control module-specific phenotypic plasticity in beetle weapons
Authors: Ozawa Takane , Mizuhara Tomoko , Arata Masataka , Shimada Masakazu , Niimi Teruyuki , Okada Kensuke , Okada Yasukazu , Ohta Kunihiro
Published: December 2016

Significance

Nutritional conditions during early development influence the plastic expression of adult phenotypes. Because heightened nutrition sensitivity often characterizes the development of exaggerated traits, there should be molecular mechanisms underlying trait-specific variability. This study reveals the molecular mechanisms underlying the expression of nutrition-sensitive mandibles in the beetle
Gnatocerus cornutus
. We found that epigenetic regulators, such as histone deacetylases (HDACs) and polycomb group (PcG) proteins, contribute specifically to the plastic expression of male mandibles, with little contribution to other body modules. In addition, HDAC1 and HDAC3 perturbation resulted in opposite phenotypic effects on mandible and wing modules. Our findings provide molecular evidence of a link between distinct epigenetic modifications and module-specific phenotypic plasticity of exaggerated traits.
Substitutions of short heterologous DNA segments of intragenomic or extragenomic origins produce clustered genomic polymorphisms
Authors: Harms Klaus , Lunnan Asbjørn , Hülter Nils , Mourier Tobias , Vinner Lasse , Andam Cheryl P. , Marttinen Pekka , Fridholm Helena , Hansen Anders Johannes , Hanage William P. , Nielsen Kaare Magne , Willerslev Eske , Johnsen Pål Jarle
Published: December 2016

Significance

Clustered genomic polymorphisms in DNA, such as microindels and stretches of nucleotide changes, play an important role in genome evolution. Here, we report a mutation mechanism responsible for such genomic polymorphisms where short, single-stranded DNA molecules invade double-stranded DNA and replace short genomic segments. We show, in a bacterial model organism, that the genomic replacements occur with very low levels of sequence identity (microhomologies). The invading DNA can be of intagenomic or foreign origin. Genotoxic stress, horizontally taken-up DNA, or lack of genome maintenance functions increase the mutation frequency up to 7,000-fold. Bioinformatic approaches suggest that this class of mutations is widespread in prokaryotes and eukaryotes and may have a role in tumorigenesis.
Twenty-first century approaches to ancient problems: Climate and society
Authors: d’Alpoim Guedes Jade A. , Crabtree Stefani A. , Bocinsky R. Kyle , Kohler Timothy A.
Published: December 2016

By documenting how humans adapted to changes in their environment that are often much greater than those experienced in the instrumental record, archaeology provides our only deep-time laboratory for highlighting the circumstances under which humans managed or failed to find to adaptive solutions to changing climate, not just over a few generations but over thelongue durée. Patterning between climate-mediated environmental change and change in human societies has, however, been murky because of low spatial and temporal resolution in available datasets, and because of failure to model the effects of climate change on local resources important to human societies. In this paper we review recent advances in computational modeling that, in conjunction with improving data, address these limitations. These advances include network analysis, niche and species distribution modeling, and agent-based modeling. These studies demonstrate the utility of deep-time modeling for calibrating our understanding of how climate is influencing societies today and may in the future.
Biasing genome-editing events toward precise length deletions with an RNA-guided TevCas9 dual nuclease
Authors: Wolfs Jason M. , Hamilton Thomas A. , Lant Jeremy T. , Laforet Marcon , Zhang Jenny , Salemi Louisa M. , Gloor Gregory B. , Schild-Poulter Caroline , Edgell David R.
Published: December 2016

Significance

Most genome-editing nucleases introduce a double-strand break at a target site, leaving compatible DNA ends that are repaired by the nonhomologous end joining repair pathway to regenerate the target site. This leads to a cycle of cleavage, target site regeneration by ligation, and subsequent recleavage by the nuclease. Here, we bypass this cycle by developing and testing an RNA-guided dual active site nuclease that introduces two noncompatible DNA breaks at a target site, deleting the majority of the target site so that it cannot be regenerated. The dual nuclease (TevCas9) robustly functions in HEK293 and biases genome-editing outcomes toward defined length deletions at high frequencies. Potential applications include directional oligonucleotide ligation, deletion of DNA-binding sites, and in-frame protein deletions.
Expression of KIR2DS1 by decidual natural killer cells increases their ability to control placental HCMV infection
Authors: Crespo Ângela C. , Strominger Jack L. , Tilburgs Tamara
Published: December 2016

Significance

The etiology of pregnancy complications such as miscarriage, preterm birth, and preeclampsia are largely unknown. The combination of the maternal Killer Immunoglobulin-like Receptor-2DS1 (KIR2DS1) with fetal HLA-C was identified as a factor determining risk of pregnancy complications. Thus decidual natural killer cells (dNK) that express high levels of KIR may have a predominant role in pregnancy outcome. Although the dNK effect has been associated with cytokine and growth factor production to promote placentation, here we show that the combination of maternal KIR and HLA-C is also a factor that determines protection against placental human cytomegalovirus (HCMV) infections. Expression of KIR2DS1 by dNK increases the cytotoxic response of dNK to HLA-C2+ HCMV-infected maternal decidual stromal cells, preventing viral spread and placental pathology.
Interrogating the
Escherichia coli
cell cycle by cell dimension perturbations
Authors: Zheng Hai , Ho Po-Yi , Jiang Meiling , Tang Bin , Liu Weirong , Li Dengjin , Yu Xuefeng , Kleckner Nancy E. , Amir Ariel , Liu Chenli
Published: December 2016

Significance

How bacteria regulate cell division to achieve cell size homeostasis, with concomitant coordination of DNA replication, is a fundamental question. Currently, there exist several competing models for cell cycle regulation in
Escherichia coli
. We performed experiments where we systematically perturbed cell dimensions and found that average cell volume scales exponentially with the product of the growth rate and the time from initiation of DNA replication to the corresponding cell division. Our data support a model in which cells initiate replication on average at a constant volume per origin and divide a constant time thereafter.
DNA demethylation is initiated in the central cells of
Arabidopsis
and rice
Authors: Park Kyunghyuk , Kim M. Yvonne , Vickers Martin , Park Jin-Sup , Hyun Youbong , Okamoto Takashi , Zilberman Daniel , Fischer Robert L. , Feng Xiaoqi , Choi Yeonhee , Scholten Stefan
Published: December 2016

Significance

Flowering plant reproduction involves two fertilization events: a sperm–egg fusion that forms the embryo, and a sperm–central cell fusion that forms the nutritive extraembryonic endosperm. Chromosomes in the embryo, endosperm, and other plant tissues are modified by methylation, a covalent addition to cytosine in DNA that regulates gene expression. Maternal endosperm chromosomes inherited from the central cell display a pattern of extensive demethylation, which is essential for seed development in
Arabidopsis thaliana
. Demethylation is presumed to occur in the central cell, but direct evidence for this is very limited. Here, we provide a genome-wide DNA methylation analysis of
Arabidopsis
and rice central cells, which demonstrates that the demethylation observed in the endosperm is indeed initiated in the central cell.
Investigation of the 4-Quadrant behaviour of a mixed flow diffuser pump with CFD-methods and test rig evaluation
Authors: Höller S. , Benigni H. , Jaberg H.
Published: December 2016

The complete pump characteristics including its 4-quadrant behaviour are of essential interest for off-design operations such as a pump trip. At this exceptional load case the pump enters the dissipation mode and moves further into the turbine mode while the direction of rotation and the flow direction will change. The time-consuming and expensive experimental investigation of the 4-quadrant behaviour requires a specific test rig, allowing the flow direction as well as the rotational direction of the investigated pump to be reverted. By measuring the pump performance (head and efficiency) at variable positive and negative discharge and rotation the complete pump characteristics are evaluated. Nowadays CFD- analysis allows for the reliable prediction of the hydraulic performance of a pump near the design point. However, abnormal operating conditions lead to complex and unsteady flow phenomena inside the pump. Besides steady-state calculations in the normal operating conditions quite comprehensive transient CFD-investigations are required to simulate the whole pump characteristics accurately. The present study focuses on the comparison of the results obtained on the test rig and by numerical methods and shows a remarkably good agreement between them. It can be shown that it is possible to reliably simulate the 4-quadrant behaviour of a mixed flow diffuser pump based on CFD-methods. Furthermore an exemplary waterhammer calculation shows the successful application of the numerically calculated 4- quadrant behaviour.
Empirical Model With Excellent Statistical Properties for Describing Temperature-Dependent Developmental Rates of Insects and Mites
Authors: Ratkowsky David A. , Reddy Gadi V. P.
Published: December 2016

Previous empirical models for describing the temperature-dependent development rates for insects include the Briére, Lactin, Beta, and Ratkowsky models. Another nonlinear regression model, not previously considered in population entomology, is the Lobry–Rosso–Flandrois model, the shape of which is very close to that of the Ratkowsky model in the suboptimal temperature range, but which has the added advantage that all four of its parameters have biological meaning. A consequence of this is that initial parameter estimates, needed for solving the nonlinear regression equations, are very easy to obtain. In addition, the model has excellent statistical properties, with the estimators of the parameters being “close-to-linear,” which means that the least squares estimators are close to being unbiased, normally distributed, minimum variance estimators. The model describes the pooled development rates very well throughout the entire biokinetic temperature range and deserves to become the empirical model of general use in this area.
A new method for decontamination of de novo transcriptomes using a hierarchical
clustering algorithm
Authors: Lafond-Lapalme Joël , Duceppe Marc-Olivier , Wang Shengrui , Moffett Peter , Mimee Benjamin
Published: December 2016

Motivation

The identification of contaminating sequences in a de novo assembly is challenging because of the absence of information on the target species. For sample types where the target organism is impossible to isolate from its matrix, such as endoparasites, endosymbionts and soil-harvested samples, contamination is unavoidable. A few post-assembly decontamination methods are currently available but are based only on alignments to databases, which can lead to poor decontamination.

Results

We present a new decontamination method based on a hierarchical clustering algorithm called MCSC. This method uses frequent patterns found in sequences to create clusters. These clusters are then linked to the target species or tagged as contaminants using classic alignment tools. The main advantage of this decontamination method is that it allows sequences to be tagged correctly even if they are unknown or misaligned to a database.

Availability and Implementation

Scripts and documentation about the MCSC decontamination method are available at https://github.com/Lafond-LapalmeJ/MCSC_Decontamination.

Supplementary information

Supplementary data are available at Bioinformatics online.
myGenomeBrowser: building and sharing your own genome browser
Authors: Carrere Sébastien , Gouzy Jérôme
Published: December 2016

myGenomeBrowser is a web-based environment that provides biologists with a way to build, query and share their genome browsers. This tool, that builds on JBrowse, is designed to give users more autonomy while simplifying and minimizing intervention from system administrators. We have extended genome browser basic features to allow users to query, analyze and share their data.

Availability and implementation: myGenomeBrowser is freely available at https://bbric-pipelines.toulouse.inra.fr/myGenomeBrowser and includes tutorial screencasts. Source code and installation instructions can be found at https://framagit.org/BBRIC/myGenomeBrowser. myGenomeBrowser is open-source and mainly implemented in Perl, JavaScript, Apache and Docker.
A Risk Assessment Tool for Identifying Pregnant and Postpartum Women Who May Benefit From Preexposure Prophylaxis
Authors: Pintye Jillian , Drake Alison L. , Kinuthia John , Unger Jennifer A. , Matemo Daniel , Heffron Renee A. , Barnabas Ruanne V. , Kohler Pamela , McClelland R. Scott , John-Stewart Grace
Published: December 2016

Background.

A human immunodeficiency virus (HIV) risk assessment tool for pregnant women could identify women who would most benefit from preexposure prophylaxis (PrEP) while minimizing unnecessary PrEP exposure.

Methods.

Data from a prospective study of incident HIV among pregnant/postpartum women in Kenya were randomly divided into derivation (n = 654) and validation (n = 650) cohorts. A risk score was derived using multivariate Cox proportional hazards models and standard clinical prediction rules. Ability of the tool to predict maternal HIV acquisition was assessed using the area under the curve (AUC) and Brier score.

Results.

The final risk score included the following predictors: having a male partner with unknown HIV status, number of lifetime sexual partners, syphilis, bacterial vaginosis (BV), and vaginal candidiasis. In the derivation cohort, AUC was 0.84 (95% confidence interval [CI], .72–.95) and each point increment in score was associated with a 52% (hazard ratio [HR], 1.52 [95% CI, 1.32–1.76]; P < .001) increase in HIV risk; the Brier score was 0.11. In the validation cohort, the score had similar AUC, Brier score, and estimated HRs. A simplified score that excluded BV and candidiasis yielded an AUC of 0.76 (95% CI, .67–.85); HIV incidence was higher among women with risk scores >6 than with scores ≤6 (7.3 vs 1.1 per 100 person-years, respectively; P < .001). Women with simplified scores >6 accounted for 16% of the population but 56% of HIV acquisitions.

Conclusions.

A combination of indicators routinely assessed in antenatal clinics was predictive of HIV risk and could be used to prioritize pregnant women for PrEP.
Efficacy and Tolerability of High-Dose Escitalopram in Posttraumatic Stress Disorder
Authors: Qi Wei , Gevonden Martin , Shalev Arieh
Published: December 2016

Background

Open-label trials suggest that escitalopram (up to 20 mg/d) is an effective treatment for some, but not all posttraumatic stress disorder (PTSD) patients. Higher doses of escitalopram effectively reduced major depression symptoms in patients who had not responded to regular doses. The current study examines the efficacy, tolerability, and adherence to high-dose escitalopram in PTSD.

Methods

Forty-five PTSD patients received 12 weeks of gradually increasing doses of escitalopram reaching 40 mg daily at 4 weeks. Among those, 12 participants received regular doses of antidepressants at study onset including escitalopram (n = 7). The Clinician-Administered PTSD Scale (CAPS) evaluated PTSD symptoms severity before treatment, at 3 months (upon treatment termination), and at 6 months (maintenance effect). A 20% reduction in CAPS scores was deemed clinically significant.

Results

Adverse events and medication adherence were monitored at each clinical session. Linear mixed-models analysis showed a significant reduction of mean CAPS scores (11.5 ± 18.1 points) at 3 months and maintenance of gains by 6 months (F
2,34.56 = 8.15, P = 0.001). Eleven participants (34.3%) showed clinically significant improvement at 3 months. Only 9 participants (20%) left the study. There were no serious adverse events and few mild ones with only 2 adverse events (diarrhea, 11.1%; drowsiness, 11.1%) reported by more than 10% of participants.

Conclusion

High doses of escitalopram are tolerable and well adhered to in PTSD. Their beneficial effect at a group level is due to a particularly good response in a subset of patients.Variability in prior pharmacological treatment precludes a definite attribution of the results to high doses of escitalopram.
A Validation Study of the International Consensus Diagnostic Criteria for Neuroleptic Malignant Syndrome
Authors: Gurrera Ronald J. , Mortillaro Gino , Velamoor Varadaraj , Caroff Stanley N.
Published: December 2016

Background

Neuroleptic malignant syndrome requires prompt recognition for effective management, but there are no established diagnostic criteria. This is the first validation study of recently published international expert consensus (IEC) diagnostic criteria, which include priority points assigned on the basis of the importance of each criterion for making a diagnosis of neuroleptic malignant syndrome.

Methods

Data were extracted from 221 archived telephone contact reports of clinician-initiated calls to a national telephone consultation service from 1997 to 2009; each case was given a total priority point score on the basis of the IEC criteria. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, (DSM-IV-TR) research criteria, in original form and modified to accept less than “severe” rigidity, served as the primary diagnostic reference standard. Consultants' diagnostic impressions were used as a secondary reference standard. Receiver operating characteristic curve analysis was used to optimize the priority point cutoff score with respect to the reference standards.

Results

Area under the receiver operating characteristic curve ranged from 0.715 (95% confidence interval, 0.645–0.785; P = 1.62 × 10−7) for consultant diagnoses to 0.857 (95% confidence interval, 0.808–0.907; P < 5 × 10−10) for modified DSM-IV-TR criteria. The latter was associated with 69.6% sensitivity and 90.7% specificity.

Conclusions

Agreement was best between IEC criteria with a cutoff score of 74 and modified DSM-IV-TR criteria (sensitivity, 69.6%; specificity, 90.7%); this cutoff score demonstrated the highest agreement in all comparisons. Consultant diagnoses showed much better agreement with modified, compared with original, DSM-IV-TR criteria, suggesting that the DSM-IV-TR criterion of “severe” rigidity may be more restrictive than what most knowledgeable clinicians use in practice.
Violent Extremism, Community-Based Violence Prevention, and Mental Health Professionals
Authors: Weine Stevan M. , Stone Andrew , Saeed Aliya , Shanfield Stephen , Beahrs John , Gutman Alisa , Mihajlovic Aida
Published: December 2016

New community-based initiatives being developed to address violent extremism in the United States are utilizing mental health services and leadership. This article reviews current approaches to preventing violent extremism, the contribution that mental illness and psychosocial problems can make to violent extremism, and the rationale for integrating mental health strategies into preventing violent extremism. The authors describe a community-based targeted violence prevention model and the potential roles of mental health professionals. This model consists of a multidisciplinary team that assesses at-risk individuals with comprehensive threat and behavioral evaluations, arranges for ongoing support and treatment, conducts follow-up evaluations, and offers outreach, education, and resources for communities. This model would enable mental health professionals in local communities to play key roles in preventing violent extremism through their practice and leadership.
Exploring the Effects of Using an Oral Appliance to Reduce Movement Dysfunction in an Individual With Parkinson Disease: A Single-Subject Design Study
Authors: Lane Hillary , Rose Lindsey E. , Woodbrey Megan , Arghavani David , Lawrence Michael , Cavanaugh James T.
Published: December 2016

Background and Purpose:

Clinical reports suggest that wearing an oral appliance can improve the gait and balance of an individual with Parkinson disease (PD). Our primary purpose was to systematically explore this effect using a single-subject study design and quantitative motion analysis. Secondarily, we sought to examine the quality-of-life outcomes following 1-month of routine oral appliance wear.

Methods:

The participant was a 73-year-old ambulatory man with mid-stage PD. Using an A-B-A design, for which a custom-made oral appliance served as the intervention, kinematic and kinetic data were captured during performance of Four Square Step Test, serpentine walk, and tandem walk tasks. Grip strength was quantified with a dynamometer. Quality-of-life outcomes were collected after 1 month of appliance wear using the Parkinson Disease Questionnaire-39 (PDQ-39). Perceived changes in balance, mobility, and quality of life were captured from the participant using an 11-point Global Rate of Change (GRC) scale.

Results:

Changes in mobility, postural control, and grip strength during appliance wear were suggestive of reduced movement dysfunction. The PDQ-39 revealed a significant improvement in quality of life, primarily related to increased emotional well-being, decreased stigma, and increased communication. GRC scores indicated a clinically significant improvement in ease of movement in the community (+3), ease of movement during the performance of activities of daily living (+4), and in standing balance while performing activities of daily living (+4).

Discussion and Conclusions:

Study findings provided quantitative evidence supporting the effectiveness of oral appliance wear for reducing movement dysfunction in a patient with mid-stage PD.

Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A155).
Reliability and Concurrent Validity of the Narrow Path Walking Test in Persons With Multiple Sclerosis
Authors: Rosenblum Uri , Melzer Itshak
Published: December 2016

Background and Purpose:

About 90% of people with multiple sclerosis (PwMS) have gait instability and 50% fall. Reliable and clinically feasible methods of gait instability assessment are needed. The study investigated the reliability and validity of the Narrow Path Walking Test (NPWT) under single-task (ST) and dual-task (DT) conditions for PwMS.

Methods:

Thirty PwMS performed the NPWT on 2 different occasions, a week apart. Number of Steps, Trial Time, Trial Velocity, Step Length, Number of Step Errors, Number of Cognitive Task Errors, and Number of Balance Losses were measured. Intraclass correlation coefficients (ICC2,1) were calculated from the average values of NPWT parameters. Absolute reliability was quantified from standard error of measurement (SEM) and smallest real difference (SRD). Concurrent validity of NPWT with Functional Reach Test, Four Square Step Test (FSST), 12-item Multiple Sclerosis Walking Scale (MSWS-12), and 2 Minute Walking Test (2MWT) was determined using partial correlations.

Results:

Intraclass correlation coefficients (ICCs) for most NPWT parameters during ST and DT ranged from 0.46–0.94 and 0.55–0.95, respectively. The highest relative reliability was found for Number of Step Errors (ICC = 0.94 and 0.93, for ST and DT, respectively) and Trial Velocity (ICC = 0.83 and 0.86, for ST and DT, respectively). Absolute reliability was high for Number of Step Errors in ST (SEM % = 19.53%) and DT (SEM % = 18.14%) and low for Trial Velocity in ST (SEM % = 6.88%) and DT (SEM % = 7.29%). Significant correlations for Number of Step Errors and Trial Velocity were found with FSST, MSWS-12, and 2MWT.

Discussion and Conclusions:

In persons with PwMS performing the NPWT, Number of Step Errors and Trial Velocity were highly reliable parameters. Based on correlations with other measures of gait instability, Number of Step Errors was the most valid parameter of dynamic balance under the conditions of our test.

Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A159).
A Cross-sectional Analysis of the Characteristics of Individuals With Parkinson Disease Who Avoid Activities and Participation Due to Fear of Falling
Authors: Landers Merrill R. , Lopker Morgan , Newman Molly , Gourlie Russell , Sorensen Spencer , Vong Rithea
Published: December 2016

Background and Purpose:

Avoidance behavior can have deleterious consequences on health and quality of life for persons with Parkinson disease (PD); for this reason, it is important to identify potentially mitigable characteristics. We compared the characteristics of individuals with PD who exhibit fear of falling (FOF) avoidance behavior with those who do not.

Methods:

Fifty-nine participants with PD were classified as avoiders (n = 27) or nonavoiders (n = 32) by using the Fear of Falling Avoidance Behavior Questionnaire and compared across 5 domains: demographic characteristics; PD-specific symptoms (subtype, Movement Disorder Society–Unified Parkinson's Disease Rating Scale [MDS-UPDRS], Hoehn and Yahr Scale, Parkinson's Disease Questionnaire–39 [PDQ-39]); balance and falls (fall history, Berg Balance Scale [BBS], Activities-Specific Balance Confidence [ABC] Scale, Impact of Events Scale, Consequences of Falling Questionnaire [CoFQ]); physical performance (30 Second Sit-to-Stand Test, Timed Up and Go Test, physical activity monitoring); and psychological factors (Zung Anxiety Scale, Beck Depression Inventory [BDI]).

Results:

There were no differences between avoiders and nonavoiders for demographic characteristics and fall history (Ps > 0.272). Avoiders had worse MDS-UPDRS (Ps < 0.014) and PDQ-39 scores (Ps < 0.028). Avoiders had poorer balance performance (BBS,P= 0.003), lower balance confidence (ABC,P< 0.001), and more fall catastrophization (CoFQ,P< 0.001). Avoiders reported more depression (P= 0.015) and anxiety (P= 0.028).

Discussion and Conclusions:

PD FOF avoiders had more involved symptoms and scored lower on balance and physical performance measures. In addition, they reported greater psychological stress. Several potentially mitigable characteristics of those with FOF avoidance behavior were identified.

Video Abstract availablefor more insights from the authors (see Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A153).
Effects of 2 Years of Exercise on Gait Impairment in People With Parkinson Disease: The PRET-PD Randomized Trial
Authors: Rafferty Miriam R. , Prodoehl Janey , Robichaud Julie A. , David Fabian J. , Poon Cynthia , Goelz Lisa C. , Vaillancourt David E. , Kohrt Wendy M. , Comella Cynthia L. , Corcos Daniel M.
Published: December 2016

Background and Purpose:

This study presents a secondary analysis from the Progressive Resistance Exercise Training in Parkinson Disease (PRET-PD) trial investigating the effects of progressive resistance exercise (PRE) and a Parkinson disease (PD)-specific multimodal exercise program, modified Fitness Counts (mFC), on spatial, temporal, and stability-related gait impairments in people with PD.

Methods:

Forty-eight people with PD were randomized to participate in PRE or mFC 2 times a week for 24 months; 38 completed the study. Gait velocity, stride length, cadence, and double-support time were measured under 4 walking conditions (off-/on-medication, comfortable/fast speed). Ankle strength was also measured off- and on-medication. Twenty-four healthy controls provided comparison data at one time point.

Results:

At 24 months, there were no significant differences between exercise groups. Both groups improved fast gait velocity off-medication, cadence in all conditions, and plantarflexion strength off-/on-medication. Both groups with PD had more gait measures that approximated the healthy controls at 24 months than at baseline. Plantarflexion strength was significantly associated with gait velocity and stride length in people with PD at baseline and 24 months, but changes in strength were not associated with changes in gait.

Discussion and Conclusions:

Twenty-four months of PRE and mFC were associated with improved off-medication fast gait velocity and improved cadence in all conditions, which is important because temporal gait measures can be resistant to medications. Spatial and stability-related measures were resistant to long-term improvements, but did not decline over 24 months. Strength gains did not appear to transfer to gait.

Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A161).
A Survey Assessment of Perceived Importance and Methods of Maintenance of Critical Procedural Skills in Pediatric Emergency Medicine
Authors: Mittiga Matthew R. , FitzGerald Michael R. , Kerrey Benjamin T.
Published: December 2016

Objective

The aim of this study was to delineate pediatric emergency medicine provider opinions regarding the importance of, and to ascertain existing processes by which practitioners maintain, the following critical procedural skills: oral endotracheal intubation, intraosseous line placement, pharmacologic and electrical cardioversion, tube thoracostomy, and defibrillation.

Methods

A customized survey was administered to all members of the Listserv for the American Academy of Pediatrics Section on Emergency Medicine. Perceived importance of maintaining critical pediatric procedural skills was measured using a 5-point Likert-type scale. Secondary outcomes included presence and type of mandatory training, availability of on-site backup, and perceived barriers to maintenance of skills.

Results

Two hundred sixty-two members (25%) responded representing 106 different institutions, 70% of freestanding children’s hospitals that received graduate medical education payments in 2014, and 68% of pediatric emergency medicine fellowship programs. More than 90% of respondents felt it was either very or extremely important to maintain competency for 5 of the 6 critical procedures, but no more than 49% of respondents felt that clinical care alone provided opportunity to maintain skills. The proportion of respondents indicating no mandatory training for each critical procedural skill was as follows: oral endotracheal intubation (23%), intraosseous line placement (30%), pharmacologic cardioversion (32%), electrical cardioversion (32%), tube thoracostomy (40%), and defibrillation (32%).

Conclusions

Critical procedural skills are perceived by emergency providers who care for children as extremely important to maintain. Direct care of pediatric patients likely does not provide sufficient opportunity to maintain these skills. There are widespread deficiencies relating to mandatory maintenance of critical procedural skill training.
Reliability of the Faces, Legs, Activity, Cry, and Consolability Scale in Assessing Acute Pain in the Pediatric Emergency Department
Authors: Kochman Adam , Howell John , Sheridan Michael , Kou Maybelle , Shelton Ryan Esther Emory , Lee Susan , Zettersten Wendy , Yoder Lauren
Published: December 2016

Objectives

The Faces, Legs, Activity, Cry, and Consolability (FLACC) scale is one of the most widely utilized observational pain assessment scales in clinical practice. Although designed and validated to assess postoperative pain, the tool is currently applied to assess acute pain in multiple settings, including the emergency department. Scarce literature exists evaluating the reliability of the FLACC scale in the nonsurgical population and none in the emergency department. We sought to investigate the reliability of the FLACC scale in assessing acute pain in the pediatric emergency department and to examine the sensitivity of FLACC scores after the administration of analgesia.

Methods

In phase 1 of this prospective study, a series of 2 independent evaluators, blinded to each other's evaluations, scored 66 patients using the FLACC tool. Degree of concordance among the 6 dyads was used to measure interrater reliability. In phase 2, FLACC scores were obtained just before the administration of analgesia in 35 patients and measured at 30 and at 60 minutes after administration.

Results

Among the 6 dyads of evaluators, Kendall W demonstrated a strong concordance (27 of 30 measures; range, 0.63–1.00) for individual components of the scale and for the composite scores (range, 0.85–0.96). Significant mean reductions from preanalgesia FLACC scores [5.54; 95% confidence interval (CI), 4.79–6.30] were seen at 30 minutes (2.00; 95% CI, 1.61–2.39) and 60 minutes (1.14; 95% CI, 0.79–1.50) postanalgesia (P < 0.0001 for all comparisons).

Conclusions

The FLACC scale demonstrated high interrater reliability for both individual FLACC items and total scores in a convenience sample of patients aged 6 months to 5 years in a pediatric emergency department. It seems to be an appropriate observational tool to assess acute pain in this population.
Hugoniot equation of state of rock materials under shock compression
Authors: Zhang Q. B. , Braithwaite C. H. , Zhao J.
Published: December 2016

Two sets of shock compression tests (i.e. conventional and reverse impact) were conducted to determine the shock response of two rock materials using a plate impact facility. Embedded manganin stress gauges were used for the measurements of longitudinal stress and shock velocity. Photon Doppler velocimetry was used to capture the free surface velocity of the target. Experimental data were obtained on a fine-grained marble and a coarse-grained gabbro over a shock pressure range of approximately 1.5–12 GPa. Gabbro exhibited a linear Hugoniot equation of state (EOS) in the pressure–particle velocity (P–up) plane, while for marble a nonlinear response was observed. The EOS relations between shock velocity (US) and particle velocity (up) are linearly fitted asUS = 2.62 + 3.319upandUS = 5.4 85 + 1.038upfor marble and gabbro, respectively.

This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.
Simplified strategies based on damage mechanics for concrete under dynamic loading
Authors: Mazars Jacky , Grange Stéphane
Published: December 2016

Based on previous work, the
µ
damage model has been designed to figure out the various damage effects in concrete correlated with monotonic and cyclic loading, including unilateral effects. Assumptions are formulated to simplify constitutive relationships while still allowing for a correct description of the main nonlinear effects. In this context, the paper presents an enhanced simplified finite-element description including a damage description, based on the use of multifibre beam elements and including strain rate effects. Applications show that such a strategy leads to an efficient tool to simulate dynamic loading at low, medium and high velocities.

This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.
Measurement of fracture properties of concrete at high strain rates
Authors: Rey-De-Pedraza V. , Cendón D. A. , Sánchez-Gálvez V. , Gálvez F.
Published: December 2016

An analysis of the spalling technique of concrete bars using the modified Hopkinson bar was carried out. A new experimental configuration is proposed adding some variations to previous works. An increased length for concrete specimens was chosen and finite-element analysis was used for designing a conic projectile to obtain a suitable triangular impulse wave. The aim of this initial work is to establish an experimental framework which allows a simple and direct analysis of concrete subjected to high strain rates. The efforts and configuration of these primary tests, as well as the selected geometry and dimensions for the different elements, have been focused to achieve a simple way of identifying the fracture position and so the tensile strength of tested specimens. This dynamic tensile strength can be easily compared with previous values published in literature giving an idea of the accuracy of the method and technique proposed and the possibility to extend it in a near future to obtain other mechanical properties such as the fracture energy. The tests were instrumented with strain gauges, accelerometers and high-speed camera in order to validate the results by different ways. Results of the dynamic tensile strength of the tested concrete are presented.

This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.
In situ
observation of fracture processes in high-strength concretes and limestone using high-speed X-ray phase-contrast imaging
Authors: Parab Niranjan D. , Guo Zherui , Hudspeth Matthew , Claus Benjamin , Lim Boon Him , Sun Tao , Xiao Xianghui , Fezzaa Kamel , Chen Weinong W.
Published: December 2016

The mechanical properties and fracture mechanisms of geomaterials and construction materials such as concrete are reported to be dependent on the loading rates. However, the
in situ
cracking inside such specimens cannot be visualized using traditional optical imaging methods since the materials are opaque. In this study, the
in situ
sub-surface failure/damage mechanisms in Cor-Tuf (a reactive powder concrete), a high-strength concrete (HSC) and Indiana limestone under dynamic loading were investigated using high-speed synchrotron X-ray phase-contrast imaging. Dynamic compressive loading was applied using a modified Kolsky bar and fracture images were recorded using a synchronized high-speed synchrotron X-ray imaging set-up. Three-dimensional synchrotron X-ray tomography was also performed to record the microstructure of the specimens before dynamic loading. In the Cor-Tuf and HSC specimens, two different modes of cracking were observed: straight cracking or angular cracking with respect to the direction of loading. In limestone, cracks followed the grain boundaries and voids, ultimately fracturing the specimen. Cracks in HSC were more tortuous than the cracks in Cor-Tuf specimens. The effects of the microstructure on the observed cracking behaviour are discussed.

This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.
High-performance concrete engineered for protective barriers
Authors: Dancygier Avraham N.
Published: December 2016

This paper reviews the effects of high-performance concrete mix ingredients on its resistance to impact of non-deforming projectiles, and on the resistance of layered barriers, engineered based on these findings. First, the reported effects of the aggregate types and sizes and the application of steel fibres, which were observed experimentally, are presented, considering resistance parameters that include the impact energy at the ballistic limit, the extent of the damaged areas at the impacted (front) and rear faces and the overall damage. These findings indicate that a protective barrier may be engineered to have layers that utilize these effects to produce a better performance under impact. Results from reported experiments of double-layered specimens, which examined the effects of the aggregate size and application of fibres, confirm this idea to a certain extent. They lead to conclusions regarding the importance of fibres in mitigating the damage, the use of large aggregates in a thicker front layer and their associated effect on increasing the damage at the front, impacted face. A ‘resistance index’ is proposed to quantify the resistance in a comprehensive way and the experimental results have been re-evaluated in view of this parameter.

This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.
A pulse-shaping technique to investigate the behaviour of brittle materials subjected to plate-impact tests
Authors: Forquin Pascal , Zinszner Jean-Luc
Published: December 2016

Owing to their significant hardness and compressive strengths, ceramic materials are widely employed for use with protective systems subjected to high-velocity impact loadings. Therefore, their mechanical behaviour along with damage mechanisms need to be significantly investigated as a function of loading rates. However, the classical plate-impact testing procedures produce shock loadings in the brittle sample material which cause unrealistic levels of loading rates. Additionally, high-pulsed power techniques and/or functionally graded materials used as flyer plates to smooth the loading pulse remain costly, and are generally difficult to implement. In this study, a shockless plate-impact technique based on the use of either a wavy-machined flyer plate or buffer plate that can be produced by chip-forming is proposed. A series of numerical simulations using an explicit transient dynamic finite-element code have been performed to design and validate the experimental testing configuration. The calculations, conducted in two-dimensional (2D) plane-strain or in 2D axisymmetric modes, prove that the ‘wavy’ contact surface will produce a pulse-shaping effect, whereas the buffer plate will produce a homogenizing effect of the stress field along the transverse direction of the sample. In addition, ‘wavy-shape’ geometries of different sizes provide an easy way to change the level of loading rate and rise time in an experimentally tested ceramic specimen. Finally, when a shockless compression loading method is applied to the sample, a Lagrangian analysis of data is made possible by considering an assemblage of ceramic plates of different thicknesses in the target, so the axial stress–strain response of the brittle sample material can be provided.

This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.
Brittle materials at high-loading rates: an open area of research
Authors: Forquin Pascal
Published: December 2016

Brittle materials are extensively used in many civil and military applications involving high-strain-rate loadings such as: blasting or percussive drilling of rocks, ballistic impact against ceramic armour or transparent windshields, plastic explosives used to damage or destroy concrete structures, soft or hard impacts against concrete structures and so on. With all of these applications, brittle materials are subjected to intense loadings characterized by medium to extremely high strain rates (few tens to several tens of thousands per second) leading to extreme and/or specific damage modes such as multiple fragmentation, dynamic cracking, pore collapse, shearing, mode II fracturing and/or microplasticity mechanisms in the material. Additionally, brittle materials exhibit complex features such as a strong strain-rate sensitivity and confining pressure sensitivity that justify expending greater research efforts to understand these complex features. Currently, the most popular dynamic testing techniques used for this are based on the use of split Hopkinson pressure bar methodologies and/or plate-impact testing methods. However, these methods do have some critical limitations and drawbacks when used to investigate the behaviour of brittle materials at high loading rates. The present theme issue ofPhilosophical Transactions Aprovides an overview of the latest experimental methods and numerical tools that are currently being developed to investigate the behaviour of brittle materials at high loading rates.

This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.
Charge influences substrate recognition and self-assembly of hydrophobic FG sequences
Authors: Chen Wesley G. , Witten Jacob , Grindy Scott C. , Holten-Andersen Niels , Ribbeck Katharina
Published: December 2016

The nuclear pore complex controls the passage of molecules via hydrophobic phenylalanine-glycine (FG) domains on nucleoporins. Such FG-domains consist of repeating units of FxFG, FG, or GLFG sequences, which can be interspersed with highly charged amino acid sequences. Despite the high density of charge exhibited in certain FG-domains, if and how charge influences FG-domain self-assembly and selective binding of nuclear transport receptors is largely unexplored. Studying how individual charged amino acids contribute to nuclear pore selectivity is challenging with modernin vivoandin vitrotechniques due to the complexity of nucleoporin sequences. Here, we present a rationally designed approach to deconstruct essential components of nucleoporins down to 14 amino acid sequences. With these nucleoporin-based peptides, we systematically dissect how charge type and placement of charge influences self-assembly and selective binding of FG-containing gels. Specifically, we find that charge type determines which hydrophobic substrates FG sequences recognize while spatial localization of charge tunes hydrophobic self-assembly and receptor selectivity of FG sequences.
Genetic variation and RNA structure regulate microRNA biogenesis
Authors: Fernandez Noemi , Cordiner Ross A. , Young Robert S. , Hug Nele , Macias Sara , Cáceres Javier F.
Published: December 2016

MiRNA biogenesis is highly regulated at the post-transcriptional level; however, the role of sequence and secondary RNA structure in this process has not been extensively studied. A single G to A substitution present in the terminal loop of pri-mir-30c-1 in breast cancer patients had been previously described to result in increased levels of mature miRNA. Here, we report that this genetic variant directly affects Drosha-mediated processing of pri-mir-30c-1 invitroand in cultured cells. Structural analysis of this variant revealed an altered RNA structure that facilitates the interaction with SRSF3, an SR protein family member that promotes pri-miRNA processing. Our results are compatible with a model whereby a genetic variant in pri-mir-30c-1 leads to a secondary RNA structure rearrangement that facilitates binding of SRSF3 resulting in increased levels of miR-30c. These data highlights that primary sequence determinants and RNA structure are key regulators of miRNA biogenesis.