The effect of visual sensory interference during multitask obstacle crossing in younger and older adults.

When older adults step over obstacles during multitasking, their performance is impaired; the impairment results from central and/or sensory interference. The purpose was to determine if sensory interference alters performance under low levels of cognitive, temporal, and gait demand, and if the change in performance is different for younger versus older adults. Participants included 17 younger adults (20.9±1.9 years) and 14 older adults (69.7±5.4 years). The concurrent task was a single, simple reaction time (RT) task: depress button in response to light cue. The gait task was stepping over an obstacle (8 m walkway) in three conditions: (1) no sensory interference (no RT task), (2) low sensory interference (light cue on obstacle, allowed concurrent foveation of cue and obstacle), or (3) high sensory interference (light cue away from obstacle, prevented concurrent foveation of cue and obstacle). When standing, the light cue location was not relevant (no sensory interference). An interaction (sensory interference by task, p<0.01) indicated that RT was longer for high sensory interference during walking, but RT was not altered for standing, confirming that sensory interference increased RT during obstacle approach. An interaction (sensory interference by age, p<0.01) was observed for foot placement before the obstacle: With high sensory interference, younger adults placed the trail foot closer to the obstacle while older adults placed it farther back from the obstacle. The change increases the likelihood of tripping with the trail foot for younger adults, but with the lead limb for older adults. Recovery from a lead limb trip is more difficult due to shorter time for corrective actions. Overall, visual sensory interference impaired both RT and gait behavior with low levels of multitask demand. Changes in foot placement increased trip risk for both ages, but for different limbs, reducing the likelihood of balance recovery in older adults.

Risky behavior during stair descent for young adults: Differences in men versus women.

Injuries commonly occur on stairs, with high injury rates in young adults, especially young women. High injury rates could result from physiological and/or behavioral differences; this study focuses on behaviors. The purposes of this observational study were (1) to quantify young adult behaviors during stair descent and (2) to identify differences in stair descent behavior for young adult men versus women. Young adult pedestrians (N = 2,400, 1,470 men and 930 women) were videotaped during descent of two indoor campus staircases, a short staircase (2 steps) and a long staircase (17 steps). Behaviors during stair descent were coded by experimenters. Risky behaviors observed on the short staircase included: No one used the handrail, 16.1% used an electronic device, and 16.4% had in-person conversations. On the long staircase: 64.8% of pedestrians did not use the handrail, 11.9% used an electronic device, and 14.5% had in-person conversations. Risky behaviors observed more in women included: less likely to use the handrail (long staircase), more likely to carry an item in their hands (both staircases), more likely to engage in conversation (both staircases), and more likely to wear sandals or heels (both staircases) (p≤0.05). Protective behaviors observed more in women included: less likely to skip steps (both staircases), and more likely to look at treads during transition steps (long staircase) (p≤0.05). The number of co-occurring risky behaviors was higher in women: 1.9 vs 2.3, for men vs women, respectively (p<0.001). Five pedestrians lost balance but did not fall; four of these pedestrians lost balance on the top step and all five had their gaze diverted from the steps at the time balance was lost. The observed behaviors may be related to the high injury rate of stair-related falls in young adults, and young women specifically.

Nursing students' experiences of safety threats and coping processes during clinical practice: A qualitative study.

BACKGROUND: Nursing students are exposed to various safety incidents during clinical practice. Frequent safety incidents cause stress, undermining their will to continue studying. Therefore, more effort is needed to analyse the scope of training safety threats perceived by nursing students and their coping processes to improve the clinical practice environment. OBJECTIVES: This study aimed to explore nursing students' safety threat experiences and coping processes during clinical practice using focus group interviews. DESIGN: A qualitative study. SETTINGS: Four nursing departments located in the G and J cities in South Korea. PARTICIPANTS: Sixteen third- and fourth-year nursing students with more than six weeks of clinical practice experience. Participants who had experienced safety-threatening incidents during their clinical practice were selected. The inclusion criteria were indirect experiences of safety-threatening incidents and exposure to incivility or physical violence from patients or caregivers. Students with no prior experience of safety incidents were excluded from this study. METHODS: Data were collected through focus group interviews conducted between 9 December and 28, 2021. RESULTS: The five main data categories extracted were safety threat cognition, action-reaction, coping process, reinforcement experience, and reinforcing conditions, and thirteen subcategories were extracted. Nursing students experienced a growing sense of responsibility for their own and patients' safety through exposure to safety-threatening situations and coping processes in clinical practice. Ultimately, they reached the stage of the core category: "seeking to protect own and patients' safety while performing the dual role." CONCLUSIONS: This study delivers basic data on the safety threat situations experienced by nursing students during clinical practice and their coping processes. It can be used in developing clinical practice safety education programs for nursing students.

The histone demethylase Kdm6b regulates subtype diversification of mouse spinal motor neurons during development.

How a single neuronal population diversifies into subtypes with distinct synaptic targets is a fundamental topic in neuroscience whose underlying mechanisms are unclear. Here, we show that the histone H3-lysine 27 demethylase Kdm6b regulates the diversification of motor neurons to distinct subtypes innervating different muscle targets during spinal cord development. In mouse embryonic motor neurons, Kdm6b promotes the medial motor column (MMC) and hypaxial motor column (HMC) fates while inhibiting the lateral motor column (LMC) and preganglionic motor column (PGC) identities. Our single-cell RNA-sequencing analyses reveal the heterogeneity of PGC, LMC, and MMC motor neurons. Further, our single-cell RNA-sequencing data, combined with mouse model studies, demonstrates that Kdm6b acquires cell fate specificity together with the transcription factor complex Isl1-Lhx3. Our study provides mechanistic insight into the gene regulatory network regulating neuronal cell-type diversification and defines a regulatory role of Kdm6b in the generation of motor neuron subtypes in the mouse spinal cord.

Assessment of low salinity waterflooding in carbonate cores: Interfacial viscoelasticity and tuning process efficiency by use of non-ionic surfactant.

HYPOTHESIS: A large number of papers discuss merits and mechanisms of low salinity waterflooding. For each mechanism proposed, there are counter examples to invalidate the stated mechanism. The effect of wettability from low salinity water, which is predominantly stated in literature as the dominant mechanism, may not be valid. We introduce a direct correlation between oil-brine interfacial viscoelasticity and oil recovery from waterflooding. EXPERIMENTS: The oil recovery is investigated in carbonate rocks for three light crude oils, by injection of a wide range of aqueous phases, ranging from deionized water to very high salinity brine of 28 wt%, and low concentration of a non-ionic surfactant at 100 ppm. The oil-brine interfacial viscoelasticity is quantified and supplementary measurements of interfacial tension and wettability are performed. FINDINGS: In our experiments, oil recovery is higher from high salinity water injection than from low salinity water injection. A strong relationship is observed between interface elasticity and oil recovery for different concentrations of salt in the injected brine as well as for ultra-low concentration surfactant. An elastic oil-brine interface results in high oil recovery. The surfactant molecule we have selected prefers the oil-water interface despite high solubility in the oil phase and makes ultra-low concentration of 100 ppm in injection water very effective. Contrary to widespread assertions in the literature, we find no definitive correlation between oil recovery and wettability.

Falls in young adults: The effect of sex, physical activity, and prescription medications.

Falls are a major public health issue not only for older adults but also young adults, with fall-related injuries occurring more frequently in adult females than males. However, the sex differences in the frequency and circumstances of falls in young adults are understudied. This research quantified the frequency and circumstances of falls as a function of sex, physical activity, and prescription medications in young adults. For 16 weeks, young adult participants (N = 325; 89 males; 19.9±1.1 years) responded to a daily email asking if they had slipped, tripped, or fallen in the past 24 hours. Falls and fall-related injuries were not uncommon in young adults: 48% fell at least once, 25% fell more than once, and 10% reported an injury. The most common activities at the time of the fall for females were walking (44%) and sports (33%), and for males, sports (49%) and walking (37%). A zero-inflated Poisson model revealed that higher number of falls were associated with the following: higher levels of physical activity (p = 0.025), higher numbers of medications (p<0.0001), and being male (p = 0.008). Regarding circumstances of falling, females were more likely to be talking to a friend at the time of the fall (OR (95% CI): 0.35 (0.14-0.73); p = 0.01). For slips and trips without a fall, males and females reported the same number of slips (OR (95% CI): 0.885 (0.638-1.227) p = 0.46), but females reported more trips (OR (95% CI): 0.45 (0.30-0.67); p<0.01). Only females reported serious injuries such as concussion and fracture. In conclusion, the rate of falls in young adults was affected by physical activity levels, number of medications, and sex. Quantifying and understanding these differences leads to increased knowledge of falls across the lifespan and is instrumental in developing interventions to prevent falls.

Step length synergy is weaker in older adults during obstacle crossing.

Community ambulation requires gait adaptations to navigate environmental obstacles. It is well known that while crossing obstacles, variables quantifying the gait pattern are controlled relative to the obstacle's position. However, the stability of these gait variables is underexplored. We measured foot positions relative to an obstacle as young and older adults stepped over it. We report secondary analysis of this data in which we quantified the stability of the step length when the two feet are placed on either side of the obstacle. We employed the uncontrolled manifold approach to test the hypotheses that (1) synergistic across-trial co-variation in the distances of the front and the back heel from the obstacle edge will stabilize the step length, and (2) older adults will display weaker synergies (i.e., lower step length stability). We observed that the front and back heel distances relative to the obstacle's edge co-varied synergistically to stabilize the step length for both age groups. Therefore, foot placement during obstacle navigation is controlled not only with reference to a feature of the environment (i.e. the obstacle), but also to stabilize the step length, presumably to control COM motion. The synergy index was 38% lower for older adults than young adults. This decline may be associated with aging-related functional deficits and tripping-related falls.

Interpersonal skills mediate the relationship between communicative and clinical competencies among nursing students: A descriptive study.

BACKGROUND: The development of clinical competency reduces nursing students' stress and turnover intention and improves their clinical practice satisfaction and academic performance. Still, many nursing supervisors feel that new graduate nurses have inadequate communicative and clinical competencies, and no prior study has analyzed the mediating effect of interpersonal skills in the relationship between these two variables. OBJECTIVES: To examine the factors that affect nursing students' clinical competency, including the mediating effect of interpersonal skills, and to identify/determine interventions that promote it and improve students' clinical performance. DESIGN: This study employed a cross-sectional, descriptive correlational design. SETTING: Four departments of nursing in Jeollabuk-do, South Korea. PARTICIPANTS: Participants (N = 222; mean age = 22.7 years; 75.2% women) were students enrolled in the third and fourth year of nursing. METHODS: From February 5-28, 2018, we collected data through self-reported questionnaires; these asked about participants' demographic characteristics and measured their communicative competency, interpersonal skills, and clinical competency. The relationships among the variables were identified using Pearson's correlation coefficient. We also used the Sobel test and a three-step multiple regression analysis to verify the mediating effects of interpersonal skills. RESULTS: Students who were female, in their fourth year, satisfied with their major, and satisfied with their clinical practice had higher clinical competency scores than their counterparts. Interpersonal skills completely mediated the effects of communicative competency on clinical competency (explanatory power = 53.8%). CONCLUSIONS: The results suggest the need for a program that improves nursing students' social relationship skills and diminishes their anxiety. In particular, students in the third and fourth years need a continuous/intensified curriculum that fosters their communicative competencies, such as listening to patients' needs and establishing effective interpersonal relationships with peers/superiors. Longitudinal studies are warranted to identify differences in communicative/clinical competencies among nursing students in different academic years.

Changes to gait speed when romantic partners walk together: Effect of age and obstructed pathway.

BACKGROUND: Walking at a brisk pace is widely recommended to promote health. When partners walk together, walking activity is increased and maintained due to enhanced social support and accountability, but at least one person must adjust their gait speed. Decreased gait speed could compromise health benefits, which may be especially relevant for the aging population. RESEARCH QUESTION: Do adults change gait speed when walking with their romantic partner, relative to walking alone, and is the change in speed affected by age or pathway conditions? METHODS: Participants were 141 individuals from 72 romantic couples; age range 25-79 years. The three couple conditions were walking alone, walking with their partner, and walking while holding hands with their partner. The two pathway conditions were clear pathway and pathway with obstacles. Gait speed was modeled as a function of the couple conditions, pathway conditions, and covariates (gender, age, relationship duration, and physical activity) using mixed-effects (3-level) regression. RESULTS: In both pathway conditions, both partners reduced speed when walking together (p < 0.001), and reduced speed further while holding hands (p < 0.001), when compared to walking alone. These effects were unchanged when covariates were included in the model. Further, speed was slower on the obstructed pathway for all participants, but the magnitude of slowing was greater with increasing age (p < 0.001) and in females (p=0.03). SIGNIFICANCE: Across the adult lifespan, when walking together, both partners decreased gait speed by a clinically meaningful amount (≥0.05 m/s). While walking with a partner may increase walking activity due to social support, reduced speed when walking together may unintentionally reduce health benefits and gait quality in both partners. Future research should identify how health is impacted by the trade-off between increased walking activity and reduced gait speed when romantic partners walk together.

PRC2 Acts as a Critical Timer That Drives Oligodendrocyte Fate over Astrocyte Identity by Repressing the Notch Pathway.

PRC2 creates the repressive mark histone H3 Lys27 trimethylation. Although PRC2 is involved in various biological processes, its role in glial development remains ambiguous. Here, we show that PRC2 is required for oligodendrocyte (OL) differentiation and myelination, but not for OL precursor formation. PRC2-deficient OL lineage cells differentiate into OL precursors, but they fail to trigger the molecular program for myelination, highlighting that PRC2 is essential for directing the differentiation timing of OL precursors. PRC2 null OL lineage cells aberrantly induce Notch pathway genes and acquire astrocytic features. The repression of the Notch pathway restores the myelination program and inhibits abnormal astrocytic differentiation in the PRC2-deficient OL lineage, indicating that Notch is a major target of PRC2. Altogether, our studies propose a specific action of PRC2 as a novel gatekeeper that determines the glial fate choice and the timing of OL lineage progression and myelination by impinging on the Notch pathway.

Effects of Environmental Enrichment on Neurotrophins in an MPTP-Induced Parkinson's Disease Animal Model: A Randomized Trial.

The aim of this study was to investigate the effect of environmental enrichment (EE) on neurotrophin expression in an animal model of Parkinson's disease (PD). PD was induced via intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Male mice (N = 42) were randomly divided into 3 groups: control, MPTP + standard condition (SC), and MPTP + EE. The groups were raised separately for 28 days. On Day 21 they received 1 injection (20 mg/kg MPTP or saline for MPTP and control groups, respectively) every 2 hr for a total of 4 injections. Animals were sacrificed 7 days after the final injection and their brains were immediately removed. Neurotrophins and messenger ribonucleic acid (mRNA) expression levels were measured. The BCL-2/Bax ratio significantly increased in the MPTP + EE compared to the MPTP + SC group. Nerve growth factor (NGF) mRNA level was upregulated (but not significantly) in the MPTP + EE compared to the MPTP + SC group. Tyrosine hydroxylase (TH) expression significantly increased in the MPTP + EE compared to the MPTP + SC group. Finally, expressions of proNGF and p75 neurotrophin receptor (p75NTR) were significantly downregulated in the MPTP + EE compared to the MPTP + SC group. Results confirm that EE has neuroprotective effects on dopaminergic neurons via suppression of activation of the p75NTR-mediated signaling pathway through the binding of proNGF and p75NTR. Findings suggest that use of EE as a therapeutic intervention would promote healthy aging by facilitating recovery following brain injury and preventing neurodegenerative diseases.

Layer-by-Layer Freezing of Nanoconfined Water.

Nanoconfined water plays a pivotal role in a vast number of fields ranging from biological and materials sciences to catalysis, nanofluidics and geochemistry. Here, we report the freezing and melting behavior of water (D2O) nanoconfined in architected silica-based matrices including Vycor glass and mesoporous silica SBA-15 and SBA-16 with pore diameters ranging between 4-15 nm, which are investigated using differential scanning calorimetry and 2H nuclear magnetic resonance spectroscopy. The results provide compelling evidence that the extreme dynamical heterogeneity of water molecules is preserved over distances as small as a few angstroms. Solidification progresses in a layer-by-layer fashion with a coexistence of liquid-like and solid-like dynamical fraction at all temperatures during the transition process. The previously reported fragile-to-strong dynamic transition in nanoconfined water is argued to be a direct consequence of the layer-by-layer solidification.

Author Correction: Single cell transcriptome analysis of developing arcuate nucleus neurons uncovers their key developmental regulators.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The effects of self-performance management video program on patients receiving hemodialysis.

AIM: This study attempted to investigate the effects of a self-performance management video program using a tablet PC on self-care knowledge, self-care behavior, state anxiety and physiological index in patients receiving hemodialysis. METHODS: This study was an experimental research design. The participants of this study were 46 patients who were diagnosed with end-stage renal failure and received hemodialysis on a regular basis in kidney centers (23: experimental group, 23: control group). The data collection period was from November 24, 2016 to January 3, 2017. The program was designed and organized by the researchers of this study according to previous studies consisting of six categories in a total 70-min video program. The contents of the self-performance management program were stored on the tablet PC, so that the patients were self-led. All the patients who participated in the program were asked to complete three categories in a week. Therefore, it took 2 weeks to complete all contents of the six categories. After that, the patients were asked to repeat the 2-week course twice. Therefore, the program was carried out for a total of 6 weeks. For the control group, a pamphlet was used. RESULTS: The anxiety of the experimental group was significantly decreased compared to the control group. Among the physiological index, potassium and albumin levels were statistically significant. CONCLUSIONS: The self-performance management video program using a tablet PC developed in this study seems to be applicable to patients receiving hemodialysis who need anxiety and physiological index management.

The Effect of Holding an Object on Postural Stability and Suprapostural Task Performance.

Holding an object has been found to reduce postural sway during quiet standing. However, people normally stand to accomplish suprapostural goals, such as fitting a key into a lock. Postural control should therefore be assessed by examining postural outcomes in the context of suprapostural task performance. This study assessed whether holding an object increased standing postural stability and improved the performance of a concurrent precision manual task. A total of 15 young adults performed a precision manual task with their dominant hand while holding or not holding an object in their nondominant hand. Postural stability was assessed using measures of postural sway and time to boundary. Suprapostural task performance was assessed as an error count. Holding did not influence postural sway or suprapostural task performance. Discrepancies among previous studies coupled with the present findings suggest that the effects of holding an object on standing posture are highly sensitive to the experimental context. The authors provide several explanations for their findings and discuss the limitations of previous suggestions that holding an object may have clinical relevance for balance-compromised populations.

Gaze diversion affects cognitive and motor performance in young adults when stepping over obstacles.

BACKGROUND: In many common multi-tasks, vision is used for two or more of the tasks, such as viewing cars, traffic signals, and the sidewalk curb at a crosswalk. RESEARCH QUESTION: How does gaze diversion affect adaptive locomotion in young adults? METHODS: Seventeen young adults completed a simple reaction time (RT) task while (1) standing and (2) during the approach to an obstacle on an 8 m walkway. Participants pressed a remote switch in response to a light cue (activated once during approach phase). The light cue was located either (1) on the obstacle (gaze diverted to obstacle) or (2) at eye level (gaze diverted away from obstacle). A gait baseline task with no RT task was included. RESULTS: An interaction was observed (task (standing versus walking) by gaze location (on versus away from obstacle), p = 0.01), where RT was not affected by the gaze location in the standing task, but RT was longer when gaze was diverted away from the obstacle in the gait task. Furthermore, trail foot placement was closer to the obstacle when the gaze was diverted away from the obstacle (p = 0.002), which increased risk of tripping. SIGNIFICANCE: Gaze diversion did not affect cognitive performance in the standing task, as information regarding the obstacle was not relevant for the standing task. However, completing a simple discrete visual cognitive task during obstacle crossing impaired both cognitive and gait performance, but only when gaze was diverted away from the obstacle. The impaired performance is likely due to the larger amount of structural interference when gaze was diverted away from the obstacle. These findings highlight the critical role of vision during the approach phase to an obstacle.

Single cell transcriptome analysis of developing arcuate nucleus neurons uncovers their key developmental regulators.

Despite the crucial physiological processes governed by neurons in the hypothalamic arcuate nucleus (ARC), such as growth, reproduction and energy homeostasis, the developmental pathways and regulators for ARC neurons remain understudied. Our single cell RNA-seq analyses of mouse embryonic ARC revealed many cell type-specific markers for developing ARC neurons. These markers include transcription factors whose expression is enriched in specific neuronal types and often depleted in other closely-related neuronal types, raising the possibility that these transcription factors play important roles in the fate commitment or differentiation of specific ARC neuronal types. We validated this idea with the two transcription factors, Foxp2 enriched for Ghrh-neurons and Sox14 enriched for Kisspeptin-neurons, using Foxp2- and Sox14-deficient mouse models. Taken together, our single cell transcriptome analyses for the developing ARC uncovered a panel of transcription factors that are likely to form a gene regulatory network to orchestrate fate specification and differentiation of ARC neurons.

Circulating MicroRNA Expression Levels Associated With Internet Gaming Disorder.

BACKGROUND: Addictive use of the Internet and online games is a potential psychiatric disorder termed Internet gaming disorder (IGD). Altered microRNA (miRNA) expression profiles have been reported in blood and brain tissue of patients with certain psychiatric disorders and suggested as biomarkers. However, there have been no reports on blood miRNA profiles in IGD. METHODS: To discover IGD-associated miRNAs, we analyzed the miRNA expression profiles of 51 samples (25 IGD and 26 controls) using the TaqMan Low Density miRNA Array. For validation, we performed quantitative reverse transcription PCR with 36 independent samples (20 IGD and 16 controls). RESULTS: Through discovery and independent validation, we identified three miRNAs (hsa-miR-200c-3p, hsa-miR-26b-5p, hsa-miR-652-3p) that were significantly downregulated in the IGD group. Individuals with all three miRNA alterations had a much higher risk of IGD than those with no alteration [odds ratio (OR) 22, 95% CI 2.29-211.11], and the ORs increased dose dependently with number of altered miRNAs. The predicted target genes of the three miRNAs were associated with neural pathways. We explored the protein expression of the three downstream target genes by western blot and confirmed that expression of GABRB2 and DPYSL2 was significantly higher in the IGD group. CONCLUSION: We observed that expressions of hsa-miR-200c-3p, hsa-miR-26b-5p, and hsa-miR-652-3p were downregulated in the IGD patients. Our results will be helpful to understand the pathophysiology of IGD.

Recapitulation of Candidate Systemic Lupus Erythematosus-Associated Variants in Koreans.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects multiple organ systems. Although the etiology of SLE remains unclear, it is widely accepted that genetic factors could be involved in its pathogenesis. A number of genome-wide association studies (GWASs) have identified novel single-nucleotide polymorphisms (SNPs) associated with the risk of SLE in diverse populations. However, not all the SNP candidates identified from non-Asian populations have been validated in Koreans. In this study, we aimed to replicate the SNPs that were recently discovered in the GWAS; these SNPs have not been validated in Koreans or have only been replicated in Koreans with an insufficient sample size to conclude any association. For this, we selected five SNPs (rs1801274 in FCGR2A and rs2286672 in PLD2, rs887369 in CXorf21, rs9782955 in LYST, and rs3794060 in NADSYN1). Through the replication study with 656 cases and 622 controls, rs1801274 in FCGR2A was found to be significantly associated with SLE in Koreans (odds ratio, 1.26, 95% confidence interval, 1.06 to 1.50; p = 0.01 in allelic model). This association was also significant in two other models (dominant and recessive). The other four SNPs did not show a significant association. Our data support that FCGR polymorphisms play important roles in the susceptibility to SLE in diverse populations, including Koreans.