Imaging the Breakdown and Restoration of Topological Protection in Magnetic Topological Insulator MnBi2Te4.

Quantum anomalous Hall (QAH) insulators transport charge without resistance along topologically protected chiral 1D edge states. Yet, in magnetic topological insulators to date, topological protection is far from robust, with zero-magnetic field QAH effect only realized at temperatures an order of magnitude below the Néel temperature TN, though small magnetic fields can stabilize QAH effect. Understanding why topological protection breaks down is therefore essential to realizing QAH effect at higher temperatures. Here a scanning tunneling microscope is used to directly map the size of exchange gap (Eg,ex) and its spatial fluctuation in the QAH insulator 5-layer MnBi2Te4. Long-range fluctuations of Eg,ex are observed, with values ranging between 0 (gapless) and 70 meV, appearing to be uncorrelated to individual surface point defects. The breakdown of topological protection is directly imaged, showing that the gapless edge state, the hallmark signature of a QAH insulator, hybridizes with extended gapless regions in the bulk. Finally, it is unambiguously demonstrated that the gapless regions originate from magnetic disorder, by demonstrating that a small magnetic field restores Eg,ex in these regions, explaining the recovery of topological protection in magnetic fields. The results indicate that overcoming magnetic disorder is the key to exploiting the unique properties of QAH insulators.

Combined Video Laryngoscope and Fiberoptic Nasal Intubation.

Techniques for facilitating nasal intubation and reducing associated airway trauma are well documented in the literature. This case series describes an additional technique that combines the use of the video laryngoscope and fiberoptic bronchoscope for intubation. Rather than first starting with the fiberoptic bronchoscope, an endotracheal tube is passed through the nasopharynx and lined up with the glottis using video laryngoscopy. Subsequently, the fiberoptic bronchoscope is used only to guide the endotracheal tube through the glottis. The two perspectives simultaneously provide enhanced guidance to the operator, which can, in turn, reduce the burden of fiberoptic navigation through blood, secretions, and/or altered airway anatomy. Additionally, our report demonstrates that this procedure can be used as a rescue measure when Magill forceps are unsuccessful.

Intervention reporting and dissemination of information for the management of hand osteoarthritis.

INTRODUCTION: A variety of exercise programs are recognized to be effective for the management of hand osteoarthritis (HOA). It is important to report the essential elements of these exercise programs for clinicians to replicate properly and facilitate their implementation with individuals who suffers from HOA, especially if they are found to be effective programs. PURPOSE OF THE STUDY: The objective of this article was to assess content reporting using three exercise reporting standardized assessment tools among exercise interventions randomized controlled trials (RCTs) involving individuals with HOA. STUDY DESIGN: A descriptive study was used. METHODS: Two pairs of trained assessors independently identified, selected, and scored the reporting quality of the exercise programs of RCTs on the management of HOA using three standardized assessment tools: the Consensus on Exercise Reporting Template (CERT) checklist, Consensus on Therapeutic Exercise Training (CONTENT) scale, and Template for Intervention Description and Replication (TIDieR) checklist to review the quality of reporting of 11 RCTs included in a recent Ottawa Panel guideline. RESULTS: Based on consensus reached by two different pairs of reviewers and an arbitrator, the mean total scores for the 11 included exercise programs were reported as follows: the mean total score for the CERT, CONTENT, and TIDieR was 10.58/19 ± 4.34, 3.27/9 ± 1.90, and 5.92/12 ± 2.54, respectively. The overall Pearson's Correlation (r) between the methodological quality and intervention reporting was 0.86, 0.71, and 0.54 for moderate-to-high RCTs and 0.47, 0.79, and 0.42 for fair-to-poor methodological quality for the CERT checklist, CONTENT scale, and TIDieR checklist, respectively. CONCLUSIONS: The intervention reporting in the management of HOA is poor among low-, moderate-, and high-quality clinical trials. The least reported information was intervention parameters related to behavior change. Improving reporting is recommended to ensure replication of effective exercise programs to enhance quality of life of individuals with HOA.

Phenological mismatch in Arctic-breeding shorebirds: Impact of snowmelt and unpredictable weather conditions on food availability and chick growth.

The ecological consequences of climate change have been recognized in numerous species, with perhaps phenology being the most well-documented change. Phenological changes may have negative consequences when organisms within different trophic levels respond to environmental changes at different rates, potentially leading to phenological mismatches between predators and their prey. This may be especially apparent in the Arctic, which has been affected more by climate change than other regions, resulting in earlier, warmer, and longer summers. During a 7-year study near Utqiagvik (formerly Barrow), Alaska, we estimated phenological mismatch in relation to food availability and chick growth in a community of Arctic-breeding shorebirds experiencing advancement of environmental conditions (i.e., snowmelt). Our results indicate that Arctic-breeding shorebirds have experienced increased phenological mismatch with earlier snowmelt conditions. However, the degree of phenological mismatch was not a good predictor of food availability, as weather conditions after snowmelt made invertebrate availability highly unpredictable. As a result, the food available to shorebird chicks that were 2-10 days old was highly variable among years (ranging from 6.2 to 28.8 mg trap-1 day-1 among years in eight species), and was often inadequate for average growth (only 20%-54% of Dunlin and Pectoral Sandpiper broods on average had adequate food across a 4-year period). Although weather conditions vary among years, shorebirds that nested earlier in relation to snowmelt generally had more food available during brood rearing, and thus, greater chick growth rates. Despite the strong selective pressure to nest early, advancement of nesting is likely limited by the amount of plasticity in the start and progression of migration. Therefore, long-term climatic changes resulting in earlier snowmelt have the potential to greatly affect shorebird populations, especially if shorebirds are unable to advance nest initiation sufficiently to keep pace with seasonal advancement of their invertebrate prey.

Content Reporting in Post-Stroke Therapeutic Circuit-Class Exercise Programs in randomized control trials.

BACKGROUND: Therapeutic exercise in the form of group circuit-class training can improve mobility and gait while being cost-effective among patients who survived a stroke. Accurate clinical replication of interventions, especially when they are effective, is needed to advance research and treatment. However, replication is difficult when reporting is not detailed. OBJECTIVE: The objective of this study was to assess the quality of reporting of interventions within the selected studies using three different scales and to assess the criterion validity between the scales. METHODS: Two independent assessors used the CERT, the CONTENT scale, and TIDieR checklist to review the quality of reporting of 16 randomized controlled trials (RCTs) from a recent Cochrane Review. Assessments were done independently before a consensus was reached with an experienced third reviewer mediating any disagreements. Criterion validity between the three quality reporting tools was measured using weighted Cohen's kappa coefficients. RESULTS: The mean (±SD) for the CERT was 9.31 (±1.66) out of 19 points; the TIDieR checklist was 8.81 (±1.33) out of 12 points; and the CONTENT was 4.82 (±1.22) out of 9 points for the 16 included RCTs. The CERT and CONTENT scale had a fair agreement (k = 0.455, p = 0.064), while both CERT and CONTENT had only slight agreement with TIDieR (k = 0.143, p = 0.267; k = 0.200, p = 0.182, respectively). CONCLUSIONS: The results of this study indicate a lack of reporting from the 16 RCTs on post-stroke therapeutic circuit-class exercise programs. This presents a major barrier to knowledge translation and clinical implementation of effective exercise programs for stroke rehabilitation.

A study of the description of exercise programs evaluated in randomized controlled trials involving people with fibromyalgia using different reporting tools, and validity of the tools related to pain relief.

RATIONALE:: Exercise programs for the management of fibromyalgia are well recognized as being effective. However, the incomplete descriptions of exercise programs make replication and implementation difficult. Also, existing reporting tools have not been validated in relation to pain relief as well as with each other. OBJECTIVES:: This study aimed to evaluate the description of exercise programs in randomized control trials for the management of fibromyalgia using different assessment tools, and the correlations of each tool in relation to effectiveness of pain relief of fibromyalgia, and the correlations between each tool. METHOD/RESULTS:: Through a consensus made by two different pairs of reviewers and an arbitrator, the mean total scores for the exercise programs were reported: 10.61/19 for Consensus on Exercise Reporting Template; 4.17/12 for Template for Intervention Description and Replication; 7.05/12 for the Consensus on Therapeutic Exercise Training; and 2.50/4 (aerobic) and 2.36/5 (flexibility and resistance) for the 2016 American College of Sports Medicine guidelines. This demonstrates generally low reporting scores (less than 60% out of the total number of items were reported). Overall, low correlations (Cohen's kappa value, ranging from -0.47 (poor) to 0.313 (fair)) were found between all tools and pain relief. Good to excellent correlations (0.680-0.908) among the reporting tools were shown. CONCLUSION:: Incomplete descriptions of exercise programs were consistently shown among the randomized clinical trials assessed in this study. The overall weak correlations demonstrated that the reporting tools have the limited ability to determine whether exercise programs were or were not effective for pain relief among individuals with fibromyalgia.

Assessment of the content reporting for therapeutic exercise interventions among existing randomized controlled trials on knee osteoarthritis.

Purpose/Rationale: Physical exercise interventions for the management of knee osteoarthritis are well known to be effective and accessible forms of rehabilitation and symptom management. However, without adequate reporting of these interventions, accurate replication and clinical use is negatively impacted. OBJECTIVES: The main objective of this article was to assess content reporting using The Consensus on Exercise Reporting Template list and 2016 American College of Sports Medicine guidelines among moderate- to high-quality exercise interventions randomized controlled trials (total score of ≥6/10 on the PEDro scale) involving individuals with knee osteoarthritis. RESULTS: The Consensus on Exercise Reporting Template mean total score for all 47 included randomized controlled trials was 4.42 out of 19, demonstrating generally low quality of reporting. The Consensus on Exercise Reporting Template list and the 2016 American College of Sports Medicine guidelines scores were moderately correlated (based on 95% confidence interval, intraclass correlation coefficient = 0.508) for aerobic interventions only. CONCLUSION: The content analysis of exercise interventions in knee osteoarthritis demonstrated low scores for moderate- to high-quality trials. Improved standardized reporting is recommended to ensure knowledge transfer and replication of effective exercise programs for individuals with knee osteoarthritis.

Bold, Sedentary Fathead Minnows Have More Parasites.

Parasites that rely on trophic transmission can manipulate the behavior of an intermediate host to compromise the host's antipredator competence and increase the probability of reaching the next host. Selection for parasite manipulation is diminished when there is significant risk of host death to causes other than consumption by a suitable definitive host for the parasite. Consequently, behavioral manipulation by parasites can be expected to be subtle. Ornithodiplostomum ptychocheilus (Op) is a trematode parasite that has a bird-snail-fish host life cycle. Fathead minnows are a common intermediate host of Op, where metacercariae encyst in the minnow brain. In this study, we report a link between metacercarial intensity and behavior in fathead minnows. In the field, we found that roaming distance by free-living minnows over 24 h was negatively correlated with parasite intensity. In the laboratory, we found that boldness in an open field test was positively correlated with parasite intensity. These parasite-induced behavioral changes may render infected minnows more susceptible to predators, which would serve to facilitate trophic transmission of parasites to the bird host.

An Integrated Metabolomic and Microbiome Analysis Identified Specific Gut Microbiota Associated with Fecal Cholesterol and Coprostanol in Clostridium difficile Infection.

Clostridium difficile infection (CDI) is characterized by dysbiosis of the intestinal microbiota and a profound derangement in the fecal metabolome. However, the contribution of specific gut microbes to fecal metabolites in C. difficile-associated gut microbiome remains poorly understood. Using gas-chromatography mass spectrometry (GC-MS) and 16S rRNA deep sequencing, we analyzed the metabolome and microbiome of fecal samples obtained longitudinally from subjects with Clostridium difficile infection (n = 7) and healthy controls (n = 6). From 155 fecal metabolites, we identified two sterol metabolites at >95% match to cholesterol and coprostanol that significantly discriminated C. difficile-associated gut microbiome from healthy microbiota. By correlating the levels of cholesterol and coprostanol in fecal extracts with 2,395 bacterial operational taxonomic units (OTUs) determined by 16S rRNA sequencing, we identified 63 OTUs associated with high levels of coprostanol and 2 OTUs correlated with low coprostanol levels. Using indicator species analysis (ISA), 31 of the 63 coprostanol-associated bacteria correlated with health, and two Veillonella species were associated with low coprostanol levels that correlated strongly with CDI. These 65 bacterial taxa could be clustered into 12 sub-communities, with each community containing a consortium of organisms that co-occurred with one another. Our studies identified 63 human gut microbes associated with cholesterol-reducing activities. Given the importance of gut bacteria in reducing and eliminating cholesterol from the GI tract, these results support the recent finding that gut microbiome may play an important role in host lipid metabolism.

Two-week virtual reality training for dementia: Single case feasibility study.

Persons with dementia (PWD) are known to have difficulty with participation and focus during physical activity. Virtual reality (VR) offers a unique medium for motor learning but has only been used previously for cognitive assessment for PWD. Our study had two objectives: (1) investigate the feasibility and safety of an exercise-based VR training program in PWD, and (2) investigate its effects on balance and mobility. The intervention consisted of daily (5 d/wk, 1 h each) VR training sessions for 2 wk for a single research participant. Clinical balance and mobility measures were assessed 1 wk prior to, during, 1 wk following, and 1 mo after the intervention. Postintervention interviews provided qualitative feedback from the participant and his caregivers. Results indicate that VR training is feasible, safe, and enjoyable for PWD. However, balance and mobility measures were unaffected. VR training is well tolerated in a single research participant with dementia and is an engaging medium for participation in exercise.

Virtual reality exercise improves mobility after stroke: an inpatient randomized controlled trial.

BACKGROUND AND PURPOSE: Exercise using virtual reality (VR) has improved balance in adults with traumatic brain injury and community-dwelling older adults. Rigorous randomized studies regarding its efficacy, safety, and applicability with individuals after stroke are lacking. The purpose of this study was to determine whether an adjunct VR therapy improves balance, mobility, and gait in stroke rehabilitation inpatients. METHODS: A blinded randomized controlled trial studying 59 stroke survivors on an inpatient stroke rehabilitation unit was performed. The treatment group (n=30) received standard stroke rehabilitation therapy plus a program of VR exercises that challenged balance (eg, soccer goaltending, snowboarding) performed while standing. The control group (n=29) received standard stroke rehabilitation therapy plus exposure to identical VR environments but whose games did not challenge balance (performed in sitting). VR training consisted of 10 to 12 thirty-minute daily sessions for a 3-week period. Objective outcome measures of balance and mobility were assessed before, immediately after, and 1 month after training. RESULTS: Confidence intervals and effect sizes favored the treatment group on the Timed Up and Go and the Two-Minute Walk Test, with both groups meeting minimal clinical important differences after training. More individuals in the treatment group than in the control group showed reduced impairment in the lower extremity as measured by the Chedoke McMaster Leg domain (P=0.04) immediately after training. CONCLUSIONS: This VR exercise intervention for inpatient stroke rehabilitation improved mobility-related outcomes. Future studies could include nonambulatory participants as well as the implementation strategies for the clinical use of VR. CLINICAL TRIAL REGISTRATION URL: http://www.ANZCTR.org.au/. Unique identifier: ACTRN12613000710729.

High intensity and prevalence of two species of trematode metacercariae in the fathead minnow (Pimephales promelas) with no compromise of minnow anti-predator competence.

Opportunity for parasites to manipulate host behavioral phenotype may be influenced by several factors, including the host ecology and the presence of cohabiting parasites in the same host. Metacercariae of Ornithodiplostomum ptychocheilus and "black spot" Crassiphiala bulboglossa have similar life cycles. Each parasite uses a littoral snail as a first intermediate host, fathead minnows as a second intermediate host, and a piscivorous bird as a final host. Metacercariae of black spot encyst in the dermal and epidermal tissues, while metacercariae of O. ptychocheilus encyst on the brain over a region that coordinates optomotor responses. Because of site differences within the host, we predicted that O. ptychocheilus metacercariae might manipulate the behavioral phenotype of minnows to facilitate transmission to the final host, but metacercariae of black spot would not. In our study population, prevalence was 100% for O. ptychocheilus , with an overall median intensity of 105 metacercariae per minnow. Prevalence of black spot was 60%, with a median abundance and intensity of 12 and 20 metacercariae per minnow for the overall sample and for infected fish, respectively. Minnows accumulated both parasites over time, producing significant correlations between intensity and minnow body length and between intensities of the 2 parasites. Minnows infected with black spot had on average twice as many O. ptychocheilus metacercariae as similar-sized minnows without any black spot cercariae. We found no correlation between body condition of minnows and intensity for either parasite. We measured 2 aspects of anti-predator competence to test for effects linked to parasite intensity. We found no correlation between intensity of either species of parasite and latency to behavioral response to attack from a mechanical model heron, nor was there any effect of parasite intensity on a measure of shoaling affinity. The absence of any detectable effect of metacercariae on anti-predator competence in minnows may reflect selection against parasite pathology from predation by non-hosts of the parasites and overwinter mortality due to low dissolved oxygen.

Changes in tundra pond limnology: re-sampling Alaskan ponds after 40 years.

The arctic tundra ponds at the International Biological Program (IBP) site in Barrow, AK, were studied extensively in the 1970s; however, very little aquatic research has been conducted there for over three decades. Due to the rapid climate changes already occurring in northern Alaska, identifying any changes in the ponds' structure and function over the past 30-40 years can help identify any potential climate-related impacts. Current research on the IBP ponds has revealed significant changes in the physical, chemical, and biological characteristics of these ponds over time. These changes include increased water temperatures, increased water column nutrient concentrations, the presence of at least one new chironomid species, and increased macrophyte cover. However, we have also observed significant annual variation in many measured variables and caution that this variation must be taken into account when attempting to make statements about longer-term change. The Barrow IBP tundra ponds represent one of the very few locations in the Arctic where long-term data are available on freshwater ecosystem structure and function. Continued monitoring and protection of these invaluable sites is required to help understand the implications of climate change on freshwater ecosystems in the Arctic.

Multi-decadal changes in tundra environments and ecosystems: synthesis of the International Polar Year-Back to the Future project (IPY-BTF).

Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512). This article synthesizes the results from 13 papers within this Ambio Special Issue. Abiotic changes include glacial recession in the Altai Mountains, Russia; increased snow depth and hardness, permafrost warming, and increased growing season length in sub-arctic Sweden; drying of ponds in Greenland; increased nutrient availability in Alaskan tundra ponds, and warming at most locations studied. Biotic changes ranged from relatively minor plant community change at two sites in Greenland to moderate change in the Yukon, and to dramatic increases in shrub and tree density on Herschel Island, and in subarctic Sweden. The population of geese tripled at one site in northeast Greenland where biomass in non-grazed plots doubled. A model parameterized using results from a BTF study forecasts substantial declines in all snowbeds and increases in shrub tundra on Niwot Ridge, Colorado over the next century. In general, results support and provide improved capacities for validating experimental manipulation, remote sensing, and modeling studies.

Effects of ankle and hip muscle fatigue on postural sway and attentional demands during unipedal stance.

The effect of muscle fatigue on quiet standing is equivocal, including its duration/recovery and whether it leads to an increase in attentional demands. The purpose of this study was to assess the effects of ankle and hip muscle fatigue on postural sway and simple reaction time during a unipedal task. Two groups of 14 young adults (mean age=22.50±3.23) had to stand on their dominant leg for 30-s trials before and after fatigue of hip or ankle flexors and extensors. Half of the unipedal trials were performed in a dual-task condition where subjects, in addition to standing, had to respond verbally to an auditory stimulus. Sway area, and sway variability and velocity in the AP and ML planes were calculated using center of pressure data obtained from a force platform. Voice reaction time was recorded seated and during the dual-task condition to assess attentional demands. A main effect of fatigue was found for AP sway variability (p=0.027), AP sway velocity (p=0.017) and ML sway velocity (p=0.004). Both groups showed increased sway velocity in both directions and in reaction time during the dual-task condition (p<0.001), but reaction time did not increase with fatigue. A group by fatigue interaction was found significant for ML sway velocity (p=0.043). Results suggest that hip and ankle fatigue affected postural control in the fatigued plane (AP) but only hip fatigue affected postural control in the non-fatigued plane (ML sway velocity). However, fatigue did not lead to an increase in attentional demands and increased AP and ML sway velocity had recovered within 30min.