bluuebunny/crossref_metadata_2025 huggingface dataset:
Third‐grade teachers’ self‐reported use of multiplication and division models
Authors: Kosko Karl W.
Published: May 2019

Visual representations and manipulatives are a highly advocated mathematical tool for the teaching and learning of multiplication and division. Although there is some prior research on elementary teachers’ general use of manipulatives and visual representations, there is little to no specific focus on use of such representations on a specific mathematical concept. The present study examined third grade teachers’ reported use of visual representations for teaching multiplication and division. Findings indicate prevalent use of discrete models and infrequent use of continuous models. Length models and number lines are rarely used across all Common Core standards focusing on multiplication/division, with numeric‐only representations being reported frequently across all standards. Groups‐of and array models were the most prevalent visual model reported by third grade teachers. Although teachers report higher degrees of access to certain materials than previous reports on manipulative use, interview data suggests this may have more to do with purchase agreements between school districts and textbook companies than pedagogical preferences of classroom teachers. Supporting findings in prior decades, teachers in the present study report prevalent use of flashcards, charts and grid paper, and variations of counters.
Comparison of the Motor Performances of 11 and 12 Years Old Boys and Girls Skiing Athletes
Authors: Koca Feyzullah
Published: May 2019

The aim in this study, will comparison anthropometric characteristics and motor performance tests to be between according to the ages of boys and girls ski athletes. A total of 41 Girls and 47 Boys ski athletes participated in this study voluntarily. One Wey ANOVA and LSD tests were used.In this study, there were differences in height and body weights statistical (p <0.001). 12 year old girl ski athletes were taller. Again, the body weight of girls is higher than men. In this study, the Sit and Reach Test values of girls and boys at 11 years of age were significantly higher than the values of boys and girls at 12 years of age (p <0.001). There was no difference between boys and girls (p> 0.05). The flamingo test values of boys and girls 11 and 12 aged changed according to gender and age statistical (p <0.01). The plate tapping test values of boys and girls 11 and 12 aged changed according to gender and age not statistical (p >0.05). It was statistically significant that girls' sit up and Standing Long Jump value was better than boys (p <0.001). It was statistically significant that boys' Bent Arm Hang test and mini cooper test was better than girls (p <0.001).Conclusion: Anthropometric characteristics and motor performance tests were found to be within normal limits according to the ages of boys and girls ski athletes. Physical characteristics and motor performance parameters can change according age and sex for 11 and 12 aged Child. For ski training and education's plans, according age and gender should be taken into consideration on child.
Thermosensory mapping of skin wetness sensitivity across the body of young males and females at rest and following maximal incremental running
Authors: Valenza Alessandro , Bianco Antonino , Filingeri Davide
Published: May 2019

Key points

Humans lack skin receptors for wetness (i.e. hygroreceptors), yet we present a remarkable wetness sensitivity.

Afferent inputs from skin cold‐sensitive thermoreceptors are key for sensing wetness; yet, it is unknown whether males and females differ in their wetness sensitivity across their body and whether high intensity exercise modulates this sensitivity.

We mapped sensitivity to cold, neutral and warm wetness across five body regions and show that females are more sensitive to skin wetness than males, and that this difference is greater for cold than warm wetness sensitivity.

We also show that a single bout of maximal exercise reduced the sensitivity to skin wetness (i.e. hygro‐hypoesthesia) of both sexes as a result of concurrent decreases in thermal sensitivity.

These novel findings clarify the physiological mechanisms underpinning this fundamental human sensory experience. In addition, they indicate sex differences in thermoregulatory responses and will inform the design of more effective sport and protective clothing, as well as thermoregulatory models.

Humans lack skin hygroreceptors and we rely on integrating cold and tactile inputs from A‐type skin nerve fibres to sense wetness. Yet, it is unknown whether sex and exercise independently modulate skin wetness sensitivity across the body. We mapped local sensitivity to cold, neutral and warm wetness of the forehead, neck, underarm, lower back and dorsal foot in 10 males (27.8 ± 2.7 years; 1.92 ± 0.1 m2 body surface area) and 10 females (25.4 ± 3.9 years; 1.68 ± 0.1 m2 body surface area), at rest and post maximal incremental running. Participants underwent our quantitative sensory test where they reported the magnitude of thermal and wetness perceptions (visual analogue scale) resulting from the application of a cold (5°C below skin temperature) wet (0.8 mL of water), neutral wet and warm wet (5°C above skin temperature) thermal probe (1.32 cm2) to five skin sites. We found that: (i) females were ∼14% to ∼17% more sensitive to cold‐wetness than males, yet both sexes were as sensitive to neutral‐ and warm‐wetness; (ii) regional differences were present for cold‐wetness only, and these followed a craniocaudal increase that was more pronounced in males (i.e. the foot was ∼31% more sensitive than the forehead); and (iii) maximal exercise reduced cold‐wetness sensitivity over specific regions in males (i.e. ∼40% decrease in foot sensitivity), and also induced a generalized reduction in warm‐wetness sensitivity in both sexes (i.e. ∼4% to ∼6%). For the first time, we show that females are more sensitive to cold wetness than males and that maximal exercise induce hygro‐hypoesthesia. These novel findings expand our knowledge on sex differences in thermoregulatory physiology.
Effect of Leakage Flows on the Performance of a Family of Inline Centrifugal Compressors
Authors: Hazby Hamid , Casey Michael , Březina Luboš
Published: May 2019

The impact of the hub and shroud leakage flows on the compressor efficiency has been investigated for four compressor stages with flow coefficients of 0.017, 0.0265, 0.063, and 0.118 belonging to a family of centrifugal compressor stages, designed for process compressor applications. A very good agreement was observed between the measured and predicted performance when the detailed geometrical features were included in the calculations. The computational fluid dynamics (CFD) calculations indicated that addition of leakage cavities and leakage flows resulted in about 3% drop in stage polytropic efficiency for the highest flow coefficient stage. The detrimental effect of leakages increased to about 8% for the lowest flow coefficient stage investigated here. The increase in the compressor work input due to the disc windage and the leakage recirculation was estimated from the CFD calculations and compared with values obtained using 1D methods, showing a very good agreement between the two. The impact of parasitic losses on compressor efficiency has been investigated and the contribution of various loss sources to the stage efficiency is discussed.
A Review of Similitude Methods for Structural Engineering
Authors: Casaburo Alessandro , Petrone Giuseppe , Franco Francesco , De Rosa Sergio
Published: May 2019

Similitude theory allows engineers, through a set of tools known as similitude methods, to establish the necessary conditions to design a scaled (up or down) model of a full-scale prototype structure. In recent years, to overcome the obstacles associated with full-scale testing, such as cost and setup, research on similitude methods has grown and their application has expanded into many branches of engineering. The aim of this paper is to provide as comprehensive a review as possible about similitude methods applied to structural engineering and their limitations due to size effects, rate sensitivity phenomena, etc. After a brief historical introduction and a more in-depth analysis of the main methods, the paper focuses on similitude applications classified, first, by test article, then by engineering fields.
The sliding ladder problem revisited in phase space
Authors: Glane Sebastian , Müller Wolfgang H.
Published: May 2019

This paper solves the problem of a sliding ladder for the cases with and without friction at the wall and at the floor. Solutions for arbitrary initial conditions are obtained by strict application of the fundamental principles of mechanics. The validity of these solutions is discussed in context with the loss of contact of the ladder with the wall. A phase space representation is used to visualize for which initial conditions the ladder stays in contact with the wall and at which angle it would lose contact.
Coronary Artery Anomaly in a High School Football Player: A Case Report
Authors: Allen Gary , Smith Kristy , Tripp Brady , Zaremski Jason , Smith Seth
Published: May 2019

We present a case of a 17-year-old White male high school American football player who was diagnosed with an anomalous left coronary artery arising from the right coronary sinus after experiencing dizziness, near-syncope, and altered mental status during a football practice. The symptoms were recognized by an on-site certified athletic trainer who activated emergency medical response. After unremarkable initial emergency evaluation, referral to a sports cardiologist unveiled an anomalous left coronary artery arising from the right coronary sinus on echocardiogram. After surgical correction and rehabilitation, the patient was able to return to exercise activity. Anomalous coronary arteries are the second most common cause of autopsy-positive episodes of sudden cardiac death among athletes and are rarely recognized with abnormal electrocardiogram (EKG) findings prior to events. This case highlights the importance of prompt recognition, evaluation, and treatment of athletes with cardiac symptoms, and contributes to an ongoing discussion on whether echocardiograms should be considered in preparticipation evaluations.
Differing Physiological Adaptations Induced by Dry and Humid Short-Term Heat Acclimation
Authors: Tebeck Samuel T. , Buckley Jonathan D. , Bellenger Clint R. , Stanley Jamie
Published: May 2019

Purpose: To investigate the effect of a 5-day short-term heat acclimation (STHA) protocol in dry (43°C and 20% relative humidity) or humid (32°C and 80% relative humidity) environmental conditions on endurance cycling performance in temperate conditions (21°C). Methods: In a randomized, cross-over design, 11 cyclists completed each of the two 5-day blocks of STHA matched for heat index (44°C) and total exposure time (480 min), separated by 30 days. Pre- and post-STHA temperate endurance performance (4-min mean maximal power, lactate threshold 1 and 2) was assessed; in addition, a heat stress test was used to assess individual levels of heat adaptation. Results: Differences in endurance performance were unclear. Following dry STHA, gross mechanical efficiency was likely reduced (between-condition effect size dry vs humid −0.59; 90% confidence interval, −1.05 to −0.15), oxygen uptake was likely increased for a given workload (0.64 [0.14 to 1.07]), and energy expenditure likely increased (0.59 [0.17 to 1.03]). Plasma volume expansion at day 5 of acclimation was similar (within-condition outcome 4.6% [6.3%] and 5.3% [5.1%] dry and humid, respectively) but was retained for 3 to 4 days longer after the final humid STHA exposure (−0.2% [8.1%] and 4.5% [4.2%] dry and humid, respectively). Sweat rate was very likely increased during dry STHA (0.57 [0.25 to 0.89]) and possibly increased (0.18 [−0.15 to 0.50]) during humid STHA. Conclusion: STHA induced divergent adaptations between dry and humid conditions, but did not result in differences in temperate endurance performance.
Association Between Functional Movement Screen Scores and Injuries in Male College Basketball Players
Authors: Shimoura Kanako , Nakayama Yasuaki , Tashiro Yuto , Hotta Takayuki , Suzuki Yusuke , Tasaka Seishiro , Matsushita Tomofumi , Matsubara Keisuke , Kawagoe Mirei , Sonoda Takuya , Yokota Yuki , Aoyama Tomoki
Published: May 2019

Context: The functional movement screen (FMS) is an assessment tool for movement dysfunction, which is used to reduce the risk of injury. Although the relationship between the FMS composite score and injuries has been extensively studied, the association between FMS scores and injuries in only college basketball players remains unknown. Objective: To examine the relationship between the FMS score and injuries in basketball players. Design: Cross-sectional study. Setting: University research laboratory. Participants: Eighty-one male college basketball players (average age 20.1 [1.3] y) participated. Main Outcome Measures: The FMS composite score was calculated from 7 movement tests. The incidence of injuries over a 1-year period prior to the test day was determined based on a questionnaire. Individuals were categorized into 2 groups: injury (with a serious basketball-related injury resulting in the loss of practice and game time for at least 4 wk) and noninjury groups. Mann–Whitney U and chi-square tests were used to evaluate group differences in the composite FMS and 7 movement scores, respectively. Furthermore, the scores significant on univariate analyses were submitted to a multivariate logistic analysis, adjusting for participant characteristics. Results: The composite FMS scores of the 2 groups were not significantly different (P = .38). Among the 7 tasks, only the deep squat and hurdle step showed significant group differences (P = .03 and P = .001, respectively). The multivariate logistic analysis revealed that deep squat (odds ratio, 6.48; 95% confidence interval, 1.23–34.01; P = .03) and hurdle step scores (odds ratio, 25.80; 95% confidence interval, 1.81–368.73; P = .02) were significantly associated with injuries, even after adjustment for participant characteristics. Conclusions: Deep squat and hurdle step scores may be associated with injuries in basketball players. Further research should be conducted to confirm that these 2 scores can predict the incidence of injuries in basketball players.
Rehabilitation Utilizing Controlled Aerobic Activity in Patients With a Concussion: A Critically Appraised Topic
Authors: Prince Janelle , Schussler Eric , McCann Ryan
Published: May 2019

Clinical Scenario:A sport-related concussion is a common injury to the brain that may cause a variety of symptoms ranging in duration and severity. The mainstay of treatment for concussion has been rest, followed by a stepwise return to activity. This recovery process may be lengthy when symptoms persist. Aerobic exercise conducted at subsymptom and submaximal intensities has been proposed as a potential intervention for symptoms following a concussion. Therefore, the purpose of this critically appraised topic is to examine the safety of varying aerobic exercise intensities in patients with a concussion.FocusedClinical Question:Are subsymptom and submaximal exercise programs safe when implemented in a population with a symptomatic sports-related concussion when compared with traditional rest?Summary of Key Findings:Four randomized controlled trials were included for critical appraisal. The 4 studies investigated supervised and controlled aerobic exercise as early as within 1 week of with a concussion; all studies conclude that exercise is safe and may be of benefit to individuals with a concussion. Two studies support the use of submaximal exercise as a therapeutic intervention for adolescents with persistent concussion symptoms.Clinical Bottom Line:The authors conclude that controlled exercise performed within the symptom or exertion threshold of patients with concussion is safe compared with rest. It was noted that symptom changes may occur; however, the changes did not have a negative impact on long-term recovery. This research should ease concerns about prescribing physical activity when an athlete with concussion is still experiencing lingering symptoms. While specific parameters of the activity performed have not been described in detail, the individualization of each exercise program was stressed.Strength of Recommendation:Grade A.
Effect of Graft Type on Thigh Circumference, Knee Range of Motion, and Lower-Extremity Strength in Pediatric and Adolescent Males Following Anterior Cruciate Ligament Reconstruction
Authors: Sugimoto Dai , Heyworth Benton E. , Yates Brandon A. , Kramer Dennis E. , Kocher Mininder S. , Micheli Lyle J.
Published: May 2019

Context:To treat anterior cruciate ligament (ACL) injury, ACL reconstruction (ACLR) surgery is currently a standard of the care. However, effect of graft type including bone–patellar tendon–bone (BTB), hamstring tendon, or iliotibial band (ITB) on thigh size, knee range of motion (ROM), and muscle strength are understudied.Objective:To compare postoperative thigh circumference, knee ROM, and hip and thigh muscle strength in adolescent males who underwent ACLR, based on the 3 different autograft types: BTB, hamstring (HS), and ITB.Setting:Biomechanical laboratory.Participants:Male ACLR patients who are younger than 22 years of age (total N = 164).Intervention:At 6- to 9-month postoperative visits, thigh circumference, knee ROM, and hip and thigh muscle strength were measured.Main Outcome Measures:Deficits of each variable between the uninvolved and ACLR limb were compared for pediatric and adolescent ACLR males in the BTB, HS, and ITB cohorts. Baseline characteristics, including physical demographics and meniscus tear status, were compared, and differences identified were treated as covariates and incorporated in analysis of covariance.Results:Data were from 164 adolescent male ACLR patients [mean age 15.7 (1.2) years]. There were no statistical differences in thigh circumference, knee ROM, hip abductor, and hip-extensor strength among the 3 autografts. However, patients with BTB demonstrated 12.2% deficits in quadriceps strength compared with 0.5% surplus in HS patients (P = .002) and 1.2% deficits in ITB patients (P = .03). Patients with HS showed 31.7% deficits in hamstring strength compared with 5.4% deficits in BTB (P = .001) and 7.7% deficits in ITB (P = .001) groups at 6- to 9-month postoperative visits.Conclusion:Adolescent male ACLR patients with BTB and HS autografts demonstrated significant deficits in quadriceps and hamstring strength, respectively, at 6 to 9 months postoperatively. Minimal lower-extremity strength deficits were demonstrated in pediatric male ACLR patients undergoing ITB harvest.
The Effects of Blood Flow Restriction on Muscle Activation and Hypoxia in Individuals With Chronic Ankle Instability
Authors: Killinger Brian , Lauver Jakob D. , Donovan Luke , Goetschius John
Published: May 2019

Context: Muscle dysfunction is common in patients with chronic ankle instability (CAI). Blood flow restriction (BFR) may enhance muscle responses during exercise and provide an opportunity to enhance muscle adaptations to ankle rehabilitation exercises; however, there is no evidence examining the effect of BFR on muscle function in CAI patients. Objective: Examine the effects of BFR on muscle activation and oxygen saturation during submaximal ankle eversion and dorsiflexion exercises in individuals with CAI. Design: Cross-over study design. Setting: Laboratory setting. Patients (or Other Participants): Nineteen young adults with a history of CAI. Interventions: Participants performed 4 sets (30, 15, 15, and 15) of eversion and dorsiflexion resistance exercises at 30% of maximum voluntary isometric contraction during 2 conditions, BFR and control. For BFR, a cuff was applied above the knee at 80% of blood flow occlusion. For control, the cuff was not inflated. Main Outcome Measures: Fibularis longus and tibialis anterior electromyography muscle activation, lower-leg muscle oxygen saturation, and ratings of perceived exertion were recorded during exercises. Results: Average grand mean muscle activation was 5.6% greater during eversion (P = .03) and 7.7% greater during dorsiflexion (P = .01) resistance exercises with BFR compared with control; however, the magnitudes of the effects of BFR were only clinically important during the dorsiflexion exercises. Lower-leg muscle oxygen saturation was 31% to 44% lower (P < .001) during BFR exercises. Ratings of perceived exertion were significantly higher during BFR exercises (P < .001). Conclusions: Greater muscle activation and hypoxia were present during submaximal resistance exercise with BFR in participants with CAI. Greater muscle activation and hypoxia during BFR exercises may be important acute responses mediating the training-related muscle adaptations that have been observed with BFR. The presence of these acute responses in CAI patients supports further research examining BFR as a potential ankle rehabilitation tool.
Influence of Shoulder Position on Functional Control Ratio During Isokinetic Assessment
Authors: Chen Bin , Zhao Yichao , Cao Xianxin , Hu Guojiong , Chen Lincoln B. , Niu Wenxin
Published: May 2019

Context:One of the possible mechanisms leading to secondary impingement syndrome may be the strength imbalance of shoulder rotators which is known as functional control ratio (FCR). The FCR is a ratio dividing the eccentric peak torque of the external rotators by the concentric peak torque of the internal rotators. Previous studies have focused on the reproducibility and reliability of isokinetic assessment, but there is little information on the influence of variable shoulder positions on FCR.Objective:To compare shoulder FCR across 3 different shoulder abduction positions during isokinetic assessment.Design:Cross-sectional study.Setting:Biomechanics laboratory.Participants:Thirty-one healthy young university students (age 22.35 [0.95] y, weight 60.52 [9.31] kg, height 168.23 [9.47] cm).Interventions:The concentric peak torque of internal rotators and eccentric peak torque of external rotators of right shoulder were measured on an isokinetic dynamometer.Main Outcome Measures:Concentric peak torque of the internal rotators and eccentric peak torque of the external rotators, measured using an isokinetic dynamometer.Results:The concentric peak torque of internal rotators was significantly lower at 120° shoulder abduction compared with other positions (P < .001). The FCR was significantly higher at 120° shoulder abduction than 90° (P = .002) or 60° (P < .001) shoulder abduction because of the lower concentric peak torque. No significant difference was found in the FCR between the other 2 shoulder positions (P = .14).Conclusions:Shoulder position variations may influence FCR because of weakness of the internal rotators. Rehabilitation and injury prevention training programs should specifically focus on strengthening the internal rotators at more elevated angles of shoulder abduction.
Effects of Taping and Balance Exercises on Knee and Lower-Extremity Function in Amateur Soccer Players: A Randomized Controlled Trial
Authors: Espí-López Gemma V. , Serra-Añó Pilar , Cobo-Pascual David , Zarzoso Manuel , Suso-Martí Luis , Cuenca-Martínez Ferran , Inglés Marta
Published: May 2019

Context: Knee injury prevention is a critical aspect in sport rehabilitation sciences, and taping is a widely used technique in this field. Nevertheless, the role and effectiveness of a long-term application of Kinesio Taping (KT) on knee function, disability, and injury prevention remain unclear. Objective: To determine the effect of KT, alone or in combination with balance exercises (BE), on dynamic and static knee balance and flexibility. Design: Randomized trial design. Setting: University of Valencia (Spain). Participants: Forty-eight male amateur soccer players. Intervention: Participants were assigned to 3 groups: Sham KT (sKT) + BE, KT + BE, and KT in isolation. The intervention period lasted 4 weeks. Three evaluations were performed: at baseline (pre), at 2 weeks (mid), and at 4 weeks posttreatment (post). Main outcome measures: Y Balance Test, unipedal stance test, the toe touch test, and the Knee Injury and Osteoarthritis Outcome Score. Results: Both sKT + BE and KT + BE groups achieved significant pre–post improvements in SEBT, unipedal stance test, and toe touch test. The KT group only showed significant intragroup differences in the left and right unipedal stance test variable (P < .05, d = 0.76, d = 0.62, respectively). The sham KT group obtained the strongest results in all physical variables. Regarding the Knee Injury and Osteoarthritis Outcome Score, pre–post significant changes were found in the sham group (P < .05, d = 0.28). Conclusions: Both sham and real KT in combination with BE achieved significant improvements on all physical variables, and these differences were significantly greater compared with those found in the KT in the isolation group, suggesting that benefits in knee function are due to the BE. Level of Evidence: Therapy level 1b.
Quantification of the Rockfloss® Floss Band Stretch Force at Different Elongation Lengths
Authors: Cheatham Scott W. , Baker Russell
Published: May 2019

Context: Floss bands are a popular intervention used by sports medicine professionals to enhance myofascial function and mobility. The bands are often wrapped around a region of the body in an overlapping fashion (eg, 50%) and then tensioned by stretching the band to a desired length (eg, 50%). To date, no research has investigated the stretch force of the bands at different elongation lengths. Objective: The purpose of this clinical study was to quantify the Rockfloss® band stretch force at 6 different elongation lengths (ie, 25%–150%) for the 5.08- and 10.16-cm width bands. Design: Controlled laboratory study. Setting: University kinesiology laboratory. Participants: One trained researcher conducted all measurements. Procedures: The stretch force of a floss band was measured at 6 different elongation lengths with a force gauge. Main Outcome Measures: Band tension force at different band elongation lengths. Results: The stretch force values for the 5.08-cm width (2 in) were as follows: 25% = 13.53 (0.25) N, 50% = 24.57 (0.28) N, 75% = 36.18 (0.39) N, 100% = 45.89 (0.62) N, 125% = 54.68 (0.26) N, and 150% = 62.54 (0.40) N. The stretch force values for the 10.16-cm width (4 in) were as follows: 25% = 16.70 (0.35) N, 50% = 31.90 (0.52) N, 75% = 47.45 (0.44) N, 100% = 57.75 (0.24) N, 125% = 69.02 (0.28) N, and 150% = 81.10 (0.67) N. Both bandwidths demonstrated a linear increase in stretch force as the bands became longer. Conclusion: These values may help professionals to understand and document the tension force being applied at different lengths to produce a more beneficial application during treatment. Future research should determine how the different length/tensions effect the local myofascia, arterial, and vascular systems.
Climate scientists say no to flying
Authors: Langin Katie
Published: May 2019

Limiting air travel to reduce carbon footprint works for some, but not all are on board.
Single-cell genomics identifies cell type–specific molecular changes in autism
Authors: Velmeshev Dmitry , Schirmer Lucas , Jung Diane , Haeussler Maximilian , Perez Yonatan , Mayer Simone , Bhaduri Aparna , Goyal Nitasha , Rowitch David H. , Kriegstein Arnold R.
Published: May 2019

Brain cell transcriptomes in autism

Autism manifests in many ways. Despite that diversity, the disorder seems to affect specific cellular pathways, including those observed in the neocortex of patients' brains. Velmeshev
et al.
analyzed the transcriptomes of single brain cells, including neurons and glia, from patients with autism. Single-nucleus RNA sequencing analysis suggested that affected pathways regulate synapse function as well as neural outgrowth and migration. Furthermore, in patient samples, specific sets of genes enriched in upper-layer projection neurons and microglia correlated with clinical severity.

Science
, this issue p.
685
Hierarchical reasoning by neural circuits in the frontal cortex
Authors: Sarafyazd Morteza , Jazayeri Mehrdad
Published: May 2019

The brain circuits of strategic decisions

Primates can compute and integrate low-level decisions to make strategic adjustments to higher-level decisions. The neural substrates and mechanisms that allow this process are not known. Sarafyazd and Jazayeri performed single-cell recordings in the dorsomedial frontal cortex and the anterior cingulate cortex of monkeys. They observed that the two brain areas, which have been implicated in error monitoring and the control of adaptive behavior, processed signals involved in causal inference. The anterior cingulate acted downstream of the dorsomedial frontal cortex. It used graded evidence derived from errors in low-level processes in a decision hierarchy to select between longer-term behavioral strategies.

Science
, this issue p.
eaav8911
Hydrodealkenylative C(sp
3
)–C(sp
2
) bond fragmentation
Authors: Smaligo Andrew J. , Swain Manisha , Quintana Jason C. , Tan Mikayla F. , Kim Danielle A. , Kwon Ohyun
Published: May 2019

Excising an olefin

Plants produce an abundance of structurally complex terpene compounds that are useful precursors to pharmaceuticals and other fine chemicals. However, the carbon frameworks of these compounds constrain the available pathways for diversification. Smaligo
et al.
now show that successive treatment with ozone, an iron oxidant, and a hydrogen-atom donor can cleanly cleave pendant olefins from terpenes and related compounds (see the Perspective by Caille). Breaking the bond between saturated and double-bonded carbon centers offers a direct route to desirable chiral intermediates from readily available, inexpensive precursors.

Science
, this issue p.
681
; see also p.
635
An exhibition fit for a king

T. rex: The Ultimate Predator
Mark Norell, curator

American Museum of Natural History Through 9 August 2020
Authors: Black Riley
Published: May 2019

Towering models, engaging interactives, and virtual reality bring the
Tyrannosaurus rex
to life
Validation of a novel diabetic retinopathy utility index using discrete choice experiments
Authors: Fenwick Eva K , Bansback Nick , Gan Alfred Tau Liang , Ratcliffe Julie , Burgess Leonie , Wong Tien Yin , Lamoureux Ecosse Luc
Published: May 2019

Background/aims

To validate a preference-based Diabetic Retinopathy Utility Index (DRU-I) using discrete choice experiment (DCE) methods and assess disutilities associated with vision-threatening DR (VTDR: severe non-proliferative DR, proliferative DR and clinically significant macular oedema) and associated vision impairment.

Methods

The DRU-I comprises five quality-of-life dimensions, including Visual symptoms, Activity limitation/mobility, Lighting and glare, Socio-emotional well-being and Inconvenience, each rated as no, some, or a lot of difficulty. The DRU-I was developed using a DCE comprising six blocks of nine choice sets which, alongside the EuroQoL-5D (EQ-5D-3L) and Vision and Quality of Life (VisQoL) utility instruments, were interviewer-administered to participants. To ensure the DRU-I was sensitive to severe disease, we oversampled patients with VTDR. Data were analysed using conditional logit regression.

Results

Of the 220 participants (mean±SD age 60.1±11.3 years; 70.9% men), 57 (29.1%) and 139 (70.9%) had non-VTDR and VTDR, respectively, while 157 (71.4%), 20 (9.4%) and 37 (17.3%) had no, mild or moderate/severe vision impairment, respectively. Regression coefficients for all dimensions were ordered as expected, with worsening levels in each dimension being less preferred (theoretical validity). DRU-I utilities decreased as DR severity (non-VTDR=0.87; VTDR=0.80; p=0.021) and better eye vision impairment (none=0.84; mild=0.78; moderate/severe=0.72; p=0.012) increased. DRU-I utilities had low (r=0.39) and moderate (r=0.58) correlation with EQ-5D and VisQoL utilities, respectively (convergent validity).

Discussion

The DRU-I can estimate utilities associated with vision-threatening DR and associated vision impairment. It has the potential to assess the cost-effectiveness of DR interventions from a patient perspective and inform policies on resource allocation relating to DR.
Retinal haemangioblastoma associated with peripheral non-perfusion: widefield fluorescein angiography analysis of 41 cases
Authors: Dalvin Lauren A , Yu Michael D , Ancona-Lezama David Arturo , Pulido Jose S , Olsen Timothy W , Shields Carol L
Published: May 2019

Aims

To investigate the association of peripheral retinal non-perfusion with retinal haemangioblastoma.

Methods

Medical and widefield fluorescein angiography records of patients diagnosed with retinal haemangioblastoma from 1990 to 2018 were reviewed for patient demographics, tumour features, fluorescein angiography features and characteristics of peripheral retinal non-perfusion.

Results

There were 41 eyes of 40 patients with retinal haemangioblastoma imaged by widefield fluorescein angiography during this time period. Of 41 eyes, 14 (34%) had haemangioblastoma-associated peripheral retinal non-perfusion on fluorescein angiography. A comparison of eyes with versus without non-perfusion revealed younger mean age at presentation (28 vs 43 years old, p=0.05), increased prevalence of von Hippel-Lindau (VHL) disease (62% vs 22%, p=0.01), greater mean largest tumour basal diameter (3.7 vs 2.5 mm, p=0.04), greater tumour distance from optic nerve (8.4 vs 1.9 mm, p<0.01) and increased prevalence of vascular leakage from the tumour (86% vs 52%, p=0.03). After mean follow-up of 97 versus 71 months (p=0.52), eyes with non-perfusion were significantly more likely to develop neovascularisation (40% vs 0%, p<0.01) and experience a three-line or greater decrease in visual acuity (60% vs 11%, p<0.01).

Conclusion

Peripheral retinal non-perfusion can be associated with retinal haemangioblastoma, and could be more common with larger, more peripheral tumours in younger patients with VHL disease. Eyes with haemangioblastoma-associated peripheral non-perfusion could be more likely to develop neovascularisation and lose visual acuity.
Occurrence and nature of questionable research practices in the reporting of messages and conclusions in international scientific Health Services Research publications: a structured assessment of publications authored by researchers in the Netherlands
Authors: Gerrits Reinie G , Jansen Tessa , Mulyanto Joko , van den Berg Michael J , Klazinga Niek S , Kringos Dionne S
Published: May 2019

Objectives

Explore the occurrence and nature of questionable research practices (QRPs) in the reporting of messages and conclusions in international scientific Health Services Research (HSR) publications authored by researchers from HSR institutions in the Netherlands.

Design

In a joint effort to assure the overall quality of HSR publications in the Netherlands, 13 HSR institutions in the Netherlands participated in this study. Together with these institutions, we constructed and validated an assessment instrument covering 35 possible QRPs in the reporting of messages and conclusions. Two reviewers independently assessed a random sample of 116 HSR articles authored by researchers from these institutions published in international peer-reviewed scientific journals in 2016.

Setting

Netherlands, 2016.

Sample

116 international peer-reviewed HSR publications.

Main outcome measures

Median number of QRPs per publication, the percentage of publications with observed QRP frequencies, occurrence of specific QRPs and difference in total number of QRPs by methodological approach, type of research and study design.

Results

We identified a median of six QRPs per publication out of 35 possible QRPs. QRPs occurred most frequently in the reporting of implications for practice, recommendations for practice, contradictory evidence, study limitations and conclusions based on the results and in the context of the literature. We identified no differences in total number of QRPs in papers based on different methodological approach, type of research or study design.

Conclusions

Given the applied nature of HSR, both the severity of the identified QRPs, and the recommendations for policy and practice in HSR publications warrant discussion. We recommend that the HSR field further define and establish its own scientific norms in publication practices to improve scientific reporting and strengthen the impact of HSR. The results of our study can serve as an empirical basis for continuous critical reflection on the reporting of messages and conclusions.
Trends in acute stroke presentations to an emergency department: implications for specific communities in accessing acute stroke care services
Authors: Bhaskar Sonu , Thomas Peter , Cheng Qi , Clement Nik , McDougall Alan , Hodgkinson Suzanne , Cordato Dennis
Published: May 2019

Background and purpose

South Western Sydney comprises of a culturally and linguistically diverse (CALD) and lower socioeconomic status population group within the state of New South Wales. Geographic location and sociodemographic factors play important roles in access to healthcare and may be crucial in the success of time-critical acute stroke intervention. The aim of this study was to examine the trends in the delayed presentation to emergency department (ED) and identify factors associated with prehospital delay for an acute stroke/transient ischaemic attack (TIA) at a comprehensive stroke centre.

Methods

Patient health-related data were extracted for stroke/TIA discharges for the period 2009–2017. Electronic medical record data were used to determine sociodemographic characteristics and prehospital factors, and their associations with delayed presentation≥4.5 hours from stroke onset were studied.

Results

During the 9-year period, population-adjusted stroke/TIA discharge rates increased from 540 to 676 per 100 000. A significant reduction in the proportion of patients presenting to ED<4.5 hours (56% in 2009 versus 46% in 2017, p<0.001) was observed. Younger patients aged 55–64 and 65–74 years, those belonging to Polynesia, South Asia and Mainland Southeast Asia, and those not using state ambulance as the mode of arrival to the hospital were at increased risk of prehospital delay.

Conclusions

Comprehensive reappraisal of educational programmes for early stroke recognition is required in our region due to delayed ED presentations of younger and specific CALD communities of stroke/TIA patients.
Factors associated with anorectalChlamydia trachomatisorNeisseria gonorrhoeaetest positivity in women: a systematic review and meta-analysis
Authors: Lau Andrew , Kong Fabian Yuh Shiong , Huston Willa , Chow Eric P F , Fairley Christopher K , Hocking Jane S
Published: May 2019

Objectives

There has been considerable discussion about anorectalChlamydia trachomatis(CT) in women, with some calling for anorectal CT screening, but little about anorectalNeisseria gonorrhoeae(NG). Given that urogenital NG is more strongly associated with pelvic inflammatory disease, this is an evidence gap. This systematic review and meta-analysis investigates the associations between anorectal CT in women and CT positivity at other sites (urogenital/oropharyngeal) and with anal intercourse, and compares these with anorectal NG within the same study populations.

Methods

Electronic databases were searched for English-language studies published to October 2018 using the following terms: (“Chlamydia” OR “Chlamydia trachomatis”) AND ((“anal” OR “rect*” OR “anorect*”) OR (“extra?genital” OR “multi?site”)). Studies were included if anorectal NG data were available. Random-effects meta-analyses calculated pooled estimates; heterogeneity was investigated using meta-regression.

Results

25 studies were eligible. Anorectal CT positivity ranged from 0% to 17.5%, with a summary estimate of 8.0% (95% CI 7.0 to 9.1; I2=88.5%). Anorectal NG positivity ranged from 0% to 17.0%, with a summary estimate of 2.1% (95% CI 1.6 to 2.8; I2=92.7%). The association between urogenital and anorectal positivity was stronger for NG than CT (summary prevalence ratio (PR)=89.3 (95% CI 53.1 to 150.3; I2=80.1%), PR=32.2 (95% CI 25.6 to 40.7; I2=70.3%), respectively), and between oropharyngeal and anorectal positivity it was stronger for NG than CT (PR=34.8 (95% CI 10.2 to 118.2; I2=89.9%), PR=8.8 (95% CI 6.8 to 11.5; I2=58.1%), respectively). Anal intercourse was associated with anorectal NG (PR=4.3; 95% CI 2.2 to 8.6; I2=0.0%) but not with anorectal CT (PR=1.0; 95% CI 0.7 to 1.4; I2=0.0%).

Conclusions

Anorectal CT is more common than anorectal NG, but anorectal NG is more strongly associated with anal intercourse, urogenital and oropharyngeal NG, suggesting that ongoing discussion about anorectal CT should also include NG. Longitudinal data are required to further understanding of the aetiology of anorectal STIs and assess whether anorectal screening is needed in women.

Trial registration number

CRD42df017080188.
Small-mammal abundance differs between pipelines, edges, and interior boreal forest habitat
Authors: Darling A.F. , Leston L. , Bayne E.M.
Published: May 2019

Oil and gas development alters boreal forests by creating early-successional habitat and an increased amount of edge. We evaluated which small-mammal species used pipeline rights of way, the influence of vegetation recovery on pipelines, and edge effects in the adjacent forest. Meadow voles (Microtus pennsylvanicus (Ord, 1815)) were the most common species on pipelines, whereas adjacent forest was dominated by southern red-backed voles (Myodes gapperi (Vigors, 1830)), northern red-backed voles (Myodes rutilus (Pallas, 1779)), and North American deer mice (Peromyscus maniculatus (Wagner, 1845)). Deer mouse abundance was greater along pipeline transects with greater vegetation recovery. Within the forest, irrespective of vegetation recovery on pipelines, meadow voles and deer mice increased near edges. Red-backed voles showed a mixed (i.e., neutral or positive) response to edge. Vegetation variables (i.e., canopy type and cover, ground cover, stem counts, and volume of downed woody material) were important predictors of small-mammal abundance in the forest, but they could not fully account for observed edge effects. Altered small-mammal communities on and adjacent to pipelines may have implications for boreal forest management and conservation through potential changes in predator–prey dynamics and boreal food webs; these implications require further study.
Efficacy and Safety of Berberine Alone or Combined with Statins for the Treatment of Hyperlipidemia: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials
Authors: Zhang Li-Shuang , Zhang Jun-Hua , Feng Rui , Jin Xin-Yao , Yang Feng-Wen , Ji Zhao-Chen , Zhao Meng-Yu , Zhang Ming-Yan , Zhang Bo-Li , Li Xue-Mei
Published: May 2019

To systematically evaluate the efficacy and safety of berberine for the treatment of hyperlipidemia, six electronic literature databases including SinoMed, CNKI, WanFang Data, PubMed, Embase and The Cochrane Library were searched to collect clinical randomized controlled trials (RCTs) of berberine alone or combined with statins for the treatment of hyperlipidemia from the inception to 8 March 2018. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included RCTs. Then, meta-analysis was performed by using RevMan 5.3 software. A total of 11 RCTs involving 1386 patients were finally included. The results of meta-analysis showed that compared with the placebo group, berberine could significantly reduce the total cholesterol and low-density lipoprotein levels and elevate the high density lipoprotein level ([Formula: see text]). Compared with the simvastatin group, berberine was effective only in reducing the level of triglyceride ([Formula: see text], 95% CI: [Formula: see text]0.66, [Formula: see text]0.07, [Formula: see text]). There, however, was no statistical significance between the BBR group and simvastatin group in the low density lipoprotein and high density lipoprotein levels. Compared with the simvastatin group, berberine plus simvastatin was more effective in reducing the level of triglyceride ([Formula: see text], 95% CI: [Formula: see text]0.46, [Formula: see text]0.20, [Formula: see text]) and total cholesterol ([Formula: see text], 95% CI: [Formula: see text]0.60, [Formula: see text]0.12, [Formula: see text]). In terms of adverse reactions, the incidence of adverse reactions including transaminase elevation and muscle aches was lower in the berberine alone or combined with simvastatin group than that in the control group, while the instance of constipation was higher. This study suggests that berberine is effective for hyperlipidemia. The quality and quantity of included studies, however, were dissatisfactory, which might decrease the reliability of the results. Higher quality studies are needed to provide more high quality evidence.
Dynamic analysis of second kind soft-matter quasicrystals of point group 14mm
Authors: Wang Fang , Fan Tian You , Cheng Hui , Sun Zhu Feng
Published: May 2019

The hydrodynamic model for soft-matter quasicrystals with 14-fold symmetry is investigated. The 14-fold symmetry soft-matter quasicrystals belong to the second kind of soft-matter quasicrystals. The most distinction between the first and the second kinds of the soft-matter quasicrystals lies in the four elementary excitations including two phason elementary excitations exist for the latter. The equations of motion for point group 14 mm soft-matter qusicrystals are given, and an initial-boundary value problem of the equations is solved by applying the finite difference method. The effects of the phonons, first phasons, second phasons, fluid phonon and their interactions in space-time domain are explored.
Extracting the Boundaries of Clusters: A Post-Clustering Tool for Spatial Datasets
Authors: İnkaya Tülin , Kayalıgil Sinan , Özdemirel Nur Evin
Published: May 2019

Boundary extraction is a fundamental post-clustering problem. It facilitates interpretability and usability of clustering results. Also, it provides visualization and dataset reduction. However, it has not attracted much attention compared to the clustering problem itself. In this work, we address the boundary extraction of clusters in 2- and 3-dimensional spatial datasets. We propose two algorithms based on Delaunay Triangulation (DT). Numerical experiments show that the proposed algorithms generate the cluster boundaries effectively. Also, they yield significant amounts of dataset reduction.
Positive curvature and symmetry in small dimensions
Authors: Amann Manuel , Kennard Lee
Published: May 2019

Extending existing work in small dimensions, Dessai computed the Euler characteristic, signature, and elliptic genus for [Formula: see text]-manifolds of positive sectional curvature in the presence of torus symmetry. He also computes the diffeomorphism type by restricting his results to classes of manifolds known to admit non-negative curvature, such as biquotients. The first part of this paper extends Dessai’s calculations to even dimensions up to [Formula: see text]. In particular, we obtain a first characterization of the Cayley plane in such a setting. The second part studies a closely related family of manifolds called positively elliptic manifolds, and we prove a conjecture of Halperin in this context for dimensions up to [Formula: see text] or Euler characteristics up to [Formula: see text].
Existence and uniqueness of propagating terraces
Authors: Giletti Thomas , Matano Hiroshi
Published: May 2019

This work focuses on dynamics arising from reaction-diffusion equations, where the profile of propagation is no longer characterized by a single front, but by a layer of several fronts which we call a propagating terrace. This means, intuitively, that transition from one equilibrium to another may occur in several steps, that is, successive phases between some intermediate stationary states. We establish a number of properties on such propagating terraces in a one-dimensional periodic environment under very wide and generic conditions. We are especially concerned with their existence, uniqueness, and their spatial structure. Our goal is to provide insight into the intricate dynamics arising from multistable nonlinearities.