Human immunodeficiency virus prevention outcomes associated with arts-based sexual health workshop participation among Northern and Indigenous adolescents in the Northwest Territories, Canada

BACKGROUND

Contextually tailored, arts-based HIV prevention strategies hold potential to advance adolescent sexual health and wellbeing. We examined HIV prevention outcomes associated with arts-based sexual health workshop participation with Northern and Indigenous adolescents in the Northwest Territories (NWT), Canada.

METHODS

An Indigenous community-based youth agency delivered arts-based workshops in school settings to adolescents aged 13-18 in 24 NWT communities. Pre and post-test surveys included socio-demographic characteristics, sexually infections (STI) knowledge, HIV/STI risk perception, sexual relationship equity, condom use self-efficacy, and safer sex efficacy (SSE). Latent change score models were conducted to assess pre-post differences and factors associated with these differences.

RESULTS

Among participants (n = 344; mean age 14.3 years, SD: 1.3; Indigenous: 79%) most (66%) had previously attended this workshop. Latent change score models revealed a significant and large effect size for increased STI knowledge (β = 2.10, SE = 0.48, p < .001) and significant and small effect sizes for increased HIV/STI risk perception (β = 0.24, SE = 0.06, p < .001) and SSE (β = 0.16, SE = 0.07, p = .02). The largest increases across several outcomes occurred with first time workshop participants; yet previous workshop participants continued to report increases in HIV/STI risk perception and SSE.

CONCLUSION

Arts-based HIV prevention approaches show promise in advancing STI knowledge, risk perception, and SSE with Northern and Indigenous youth.

The effectiveness of maternal regulatory attempts in the development of infant emotion regulation

Caregivers are instrumental in the development of infant emotion regulation; however, few studies have focused on delineating the real-time effectiveness of strategies that caregivers use to reduce infant distress. It is also unclear whether certain caregiver traits facilitate engagement in more successful regulation strategies. This study addressed these gaps by: (1) examining the differential effectiveness of maternal regulatory attempts (MRAs; behavioral strategies initiated by mothers to assist infants with regulating emotional states) in reducing 12- to 24-month-old infants' frustration during a toy removal task; and (2) assessing whether maternal mind-mindedness (mothers' attunement to their infant's mental state) predicted mothers' selection of MRAs. Multilevel modeling revealed that distraction and control were the most effective MRAs in reducing infant negative affect across 5-s intervals (N = 82 dyads; M infant age = 18 months; 45 females). Greater use of non-attuned mind-related speech predicted less engagement in effective MRAs, supporting a link between caregivers' socio-cognitive skills and provision of in-the-moment regulation support. These findings highlight the value of considering caregiver regulatory behaviors as a target for elucidating how maternal socialization of emotion regulation occurs in real-time. They also underscore mothers' important role as socializing agents in the development of this foundational developmental ability.

Wipe it off: A meta-analytic review of the psychological consequences and antecedents of physical cleansing

Physical cleansing is a human universal. It serves health and survival functions. It also carries rich psychological meanings that interest scholars across disciplines. What psychological effects result from cleansing? What psychological states trigger cleansing? The present meta-analysis takes stock of all experimental studies examining the psychological consequences and antecedents of cleansing-related thoughts, feelings, and behaviors (e.g., feeling less guilty after cleansing; spontaneously cleansing oneself after thinking of unwelcomed sexual encounter). It includes 129 records, 230 experiments, and 551 effects from 42,793 participants. Effect sizes were synthesized in random-effects models using robust variance estimates with small-sample corrections, supplemented by other techniques. Outliers were excluded using leave-one-out diagnostics and sensitivity analysis. Publication bias was assessed and corrected for using eight methods. Theoretical, methodological, sample, and report moderators were coded. After excluding outliers, without bias correction, the synthesized effect size estimate was g = 0.315, 95% CI [0.277, 0.354]. Using various bias correction methods, the estimate ranged from g = 0.103 to 0.331 and always exhibited considerable heterogeneity. Effect sizes were especially large for behavioral measures and varied significantly between sample types, sample regions, and report types. Meanwhile, effects were domain-general (observed in the moral domain and beyond), bidirectional (physical cleansing ↔ psychological variables), and robust across theoretical types, manipulation operationalizations, and study designs. Limitations included mixed replicability, suboptimal methodological rigor, and restricted sample diversity. We recommend future studies to (a) incorporate power analysis, preregistration, and replication; (b) investigate generalizability across samples; (c) strengthen discriminant validity; and (d) test competing theoretical accounts. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Retrospective Analysis of Circumstances of Falls and Related Injuries across Levels of Care in Older Adult Retirement Home Facilities

Towards developing more effective interventions for fall-related injuries, this study analysed a novel database from six retirement home facilities over a 4-year period comprising 1,877 fallers and 12,445 falls. Falls were characterized based on location, activity, injury site, and type, and the database was stratified across four levels of care: Independent Living, Retirement Care, Assisted Care, and Memory care. Falls most occurred within the bedroom (62.8%), and during unknown (38.1%), walking (20.2%), and transfer tasks (14.6%). Approximately one in three (37%) of all falls resulted in an injury, most commonly involving the upper limb (31.8%), head (26.3%), and lower limb (22.2%), resulting in skin tears (35.3%), aches/pains (29.1%), or bruises (28.0%). While fall location, activity, and injury site were different across levels of care, injury type was not. The data from this study can assist in targeting fall-related injury prevention strategies across levels of care within retirement facilities.

Ultrastructure and Nanoporosity of Human Bone Shown with Correlative On-Axis Electron and Spectroscopic Tomographies

Mineralized collagen fibrils are the building block units of bone at the nanoscale. While it is known that collagen fibrils are mineralized both inside their gap zones (intra-fibrillar mineralization) and on their outer surfaces (extra-fibrillar mineralization), a clear visualization of this architecture in three dimensions (3D), combining structural and compositional information over large volumes, but without compromising the resolution, remains challenging. In this study, we demonstrate the use of on-axis Z-contrast electron tomography (ET) with correlative energy-dispersive X-ray spectroscopy (EDX) tomography to examine rod-shaped samples with diameters up to 700 nm prepared from individual osteonal lamellae in the human femur. Our work mainly focuses on two aspects: (i) low-contrast nanosized circular spaces ("holes") observed in sections of bone oriented perpendicular to the long axis of a long bone, and (ii) extra-fibrillar mineral, especially in terms of morphology and spatial relationship with respect to intra-fibrillar mineral and collagen fibrils. From our analyses, it emerges quite clearly that most "holes" are cross-sectional views of collagen fibrils. While this had been postulated before, our 3D reconstructions and reslicing along meaningful two-dimensional (2D) cross-sections provide a direct visual confirmation. Extra-fibrillar mineral appears to be composed of thin plates that are interconnected and span over several collagen fibrils, confirming that mineralization is cross-fibrillar, at least for the extra-fibrillar phase. EDX tomography shows mineral signatures (Ca and P) within the gap zones, but the signal appears weaker than that associated with the extra-fibrillar mineral, pointing toward the existence of dissimilarities between the two types of mineralization.

Dyads and Triads of Boron Difluoride Formazanate and Boron Difluoride Dipyrromethene Dyes

Dye-dye conjugates have attracted significant interest for their utility in applications such as bioimaging, theranostics, and light-harvesting. Many classes of organic dyes have been employed in this regard; however, building blocks don't typically extend beyond small chromophores. This can lead to minor changes to the optoelectronic properties of the original dye. The exploration of dye-dye structures is impeded by long synthetic routes, incompatible synthetic conditions, or a mismatch of the desired properties. Here, we present the first-of-their-kind dye-dye conjugates of boron difluoride complexes of formazanate and dipyrromethene ligands. These conjugates exhibit dual photoluminescence bands that reach the near-infrared spectral region and implicate anti-Kasha processes. Cyclic voltammetry experiments revealed the generation of polyanionic species that can reversibly tolerate the uptake of up to 6 electrons. Ultimately, we demonstrate that BF2 formazanates can serve as a synthetically accessible platform to build upon new classes of dye-dye conjugates.

Pain sensitivity predicts support for moral and political views across the aisle

We live in a time of exacerbating political polarization. Bridging the ideological divide is hard. Although some strategies have been found effective for interpersonal persuasion and interaction across the aisle, little is known about what intrapersonal attributes predict which individuals are more inclined to support their ideological opponent's views. The present work identifies a low-level attribute-sensitivity to physical pain-that robustly predicts individual variations in support for moral and political views typically favored by one's ideological opponent. We first summarize a psychophysical validation of an established pain sensitivity measure (n = 263), then report a series of exploratory and preregistered confirmatory studies and replications (N = 7,360) finding that more (vs. less) pain-sensitive liberal Americans show greater endorsement of moral foundations typically endorsed by conservatives (Studies 1a-1c), higher likelihood of voting for Trump over Biden in the 2020 presidential election, stronger support for Republican politicians, and more conservative attitudes toward contentious political issues (Studies 2a and 2b). Conservatives show the mirroring pattern. These "cross-aisle" effects of pain sensitivity are driven by heightened harm perception (Study 3). They defy lay intuitions (Study 4). They are not attributable to multicollinearity or response set. The consistent findings across studies highlight the value of deriving integrative predictions from multiple previously unconnected perspectives (social properties of pain, moral foundations theory, dyadic morality theory, principle of multiple determinants in higher mental processes). They open up novel directions for theorizing and research on why pain sensitivity predicts support for moral and political views across the aisle. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Photocatalyzed radiosynthesis of 11 C-phenylacetic acids

Fast and straightforward incorporation of radionuclides into pharmaceutically relevant molecules is one of the main barriers to preclinical and clinical tracer research. Late-stage direct incorporation of cyclotron-produced [11 C]CO2 to afford carbon-11-labeled radiopharmaceuticals has the potential to provide ready-to-inject positron emission tomography agents in less than an hour. The present work describes photocatalyzed carboxylation of alkylbenzene derivatives to afford 11 C-phenylacetic acids. Reaction conditions and scope are investigated followed by application of this methodology to the preparative radiosynthesis of [11 C]fenoprofen, a nonsteroidal anti-inflammatory drug.

Synapses do not facilitate prion-like transfer of alpha-synuclein: a quantitative study in reconstructed unidirectional neural networks

Alpha-synuclein (aSyn) aggregation spreads between cells and underlies the progression of neuronal lesions in the brain of patients with synucleinopathies such as Parkinson's diseases. The mechanisms of cell-to-cell propagation of aggregates, which dictate how aggregation progresses at the network level, remain poorly understood. Notably, while prion and prion-like spreading is often simplistically envisioned as a "domino-like" spreading scenario where connected neurons sequentially propagate protein aggregation to each other, the reality is likely to be more nuanced. Here, we demonstrate that the spreading of preformed aSyn aggregates is a limited process that occurs through molecular sieving of large aSyn seeds. We further show that this process is not facilitated by synaptic connections. This was achieved through the development and characterization of a new microfluidic platform that allows reconstruction of binary fully oriented neuronal networks in vitro with no unwanted backward connections, and through the careful quantification of fluorescent aSyn aggregates spreading between neurons. While this allowed us for the first time to extract quantitative data of protein seeds dissemination along neural pathways, our data suggest that prion-like dissemination of proteinopathic seeding aggregates occurs very progressively and leads to highly compartmentalized pattern of protein seeding in neural networks.

Antisenescence Therapy Improves Function in a Human Model of Cardiac Fibrosis-on-a-Chip

Cardiac fibrosis is a significant contributor to heart failure and is characterized by abnormal ECM deposition and impaired contractile function. We have previously developed a model of cardiac fibrosis via TGF-β treatment of engineered microtissues using heart-on-a-chip technology which incorporates human induced pluripotent stem cell-derived cardiomyocytes and cardiac fibroblasts. Here, we describe that these cardiac fibrotic tissues expressed markers associated with cellular senescence via transcriptomic analysis. Treatment of fibrotic tissues with the senolytic drugs dasatinib and quercetin (D+Q) led to an improvement of contractile function, reduced passive tension, and downregulated senescence-related gene expression, an outcome we were previously unable to achieve using standard-of-care drugs. The improvement in functional parameters was also associated with a reduction in fibroblast density, though no changes in absolute collagen deposition were observed. This study demonstrates the benefit of senolytic treatment for cardiac fibrosis in a human-relevant model, supporting data in animal models, and will enable the further elucidation of cell-specific effects of senolytics and how they impact cardiac fibrosis and senescence.

Examining Pathways from Food Insecurity to Safer Sex Efficacy Among Northern and Indigenous Adolescents in the Northwest Territories, Canada

BACKGROUND

Food insecurity is a social determinant of health linked with elevated HIV exposure. Safer sex efficacy (SSE), the ability to navigate sexual decision-making and condom use, is an important marker of sexual wellbeing. Pathways from food insecurity to SSE are understudied, particularly among adolescents in Arctic regions who are at the nexus of food insecurity and sexual health disparities. We examined pathways from food insecurity to SSE among adolescents in the Northwest Territories (NWT), Canada.

METHODS

We implemented cross-sectional surveys with adolescents aged 13-18 recruited through venue-based sampling in 17 NWT communities. We conducted multivariable logistic regression to assess socio-demographic factors associated with food insecurity. We then conducted structural equation modeling (SEM) using maximum likelihood estimation to assess direct effects of food insecurity on SSE and indirect effects via resilience, depression, and relationship power inequity. We assessed both condom use SSE (e.g., confidence in using condoms) and situational SSE (e.g., SSE under partner pressure).

RESULTS

Most participants (n = 410) identified as Indigenous (79%) and 45% reported experiencing food insecurity. In SEM, we did not find a significant direct effect from food insecurity to SSE; however, we found indirect effects from food insecurity to condom use SSE through resilience and depression and from food insecurity to situational SSE through resilience.

CONCLUSIONS

Findings call for structural interventions to address food insecurity, alongside resilience-focused strategies that address the intersection of sexual and mental health. Sexual health strategies focused on individual behavior change are insufficient to address larger contexts of poverty among Northern youth.

Changes in synaptic inputs to dI3 INs and MNs after complete transection in adult mice

Introduction

Spinal cord injury (SCI) is a debilitating condition that disrupts the communication between the brain and the spinal cord. Several studies have sought to determine how to revive dormant spinal circuits caudal to the lesion to restore movements in paralyzed patients. So far, recovery levels in human patients have been modest at best. In contrast, animal models of SCI exhibit more recovery of lost function. Previous work from our lab has identified dI3 interneurons as a spinal neuron population central to the recovery of locomotor function in spinalized mice. We seek to determine the changes in the circuitry of dI3 interneurons and motoneurons following SCI in adult mice.

Methods

After a complete transection of the spinal cord at T9-T11 level in transgenic Isl1:YFP mice and subsequent treadmill training at various time points of recovery following surgery, we examined changes in three key circuits involving dI3 interneurons and motoneurons: (1) Sensory inputs from proprioceptive and cutaneous afferents, (2) Presynaptic inhibition of sensory inputs, and (3) Central excitatory glutamatergic synapses from spinal neurons onto dI3 INs and motoneurons. Furthermore, we examined the possible role of treadmill training on changes in synaptic connectivity to dI3 interneurons and motoneurons.

Results

Our data suggests that VGLUT1⁺ inputs to dI3 interneurons decrease transiently or only at later stages after injury, whereas levels of VGLUT1⁺ remain the same for motoneurons after injury. Levels of VGLUT2⁺ inputs to dI3 INs and MNs may show transient increases but fall below levels seen in sham-operated mice after a period of time. Levels of presynaptic inhibition to VGLUT1⁺ inputs to dI3 INs and MNs can rise shortly after SCI, but those increases do not persist. However, levels of presynaptic inhibition to VGLUT1⁺ inputs never fell below levels observed in sham-operated mice. For some synaptic inputs studied, levels were higher in spinal cord-injured animals that received treadmill training, but these increases were observed only at some time points.

Discussion

These results suggest remodeling of spinal circuits involving spinal interneurons that have previously been implicated in the recovery of locomotor function after spinal cord injury in mice.

Critical Care Cycling to Improve Lower Extremity Strength (CYCLE): protocol for an international, multicentre randomised clinical trial of early in-bed cycling for mechanically ventilated patients

INTRODUCTION

In-bed leg cycling with critically ill patients is a promising intervention aimed at minimising immobility, thus improving physical function following intensive care unit (ICU) discharge. We previously completed a pilot randomised controlled trial (RCT) which supported the feasibility of a large RCT. In this report, we describe the protocol for an international, multicentre RCT to determine the effectiveness of early in-bed cycling versus routine physiotherapy (PT) in critically ill, mechanically ventilated adults.

METHODS AND ANALYSIS

We report a parallel group RCT of 360 patients in 17 medical-surgical ICUs and three countries. We include adults (≥18 years old), who could ambulate independently before their critical illness (with or without a gait aid), ≤4 days of invasive mechanical ventilation and ≤7 days ICU length of stay, and an expected additional 2-day ICU stay, and who do not fulfil any of the exclusion criteria. After obtaining informed consent, patients are randomised using a web-based, centralised system to either 30 min of in-bed cycling in addition to routine PT, 5 days per week, up to 28 days maximum, or routine PT alone. The primary outcome is the Physical Function ICU Test-scored (PFIT-s) at 3 days post-ICU discharge measured by assessors blinded to treatment allocation. Participants, ICU clinicians and research coordinators are not blinded to group assignment. Our sample size estimate was based on the identification of a 1-point mean difference in PFIT-s between groups.

ETHICS AND DISSEMINATION

Critical Care Cycling to improve Lower Extremity (CYCLE) is approved by the Research Ethics Boards of all participating centres and Clinical Trials Ontario (Project 1345). We will disseminate trial results through publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03471247 (Full RCT); NCT02377830 (CYCLE Vanguard 46 patient internal pilot).

Motif elucidation in ChIP-seq datasets with a knockout control

Chromatin immunoprecipitation-sequencing (ChIP-seq) is widely used to find transcription factor binding sites, but suffers from various sources of noise. Knocking out the target factor mitigates noise by acting as a negative control. Paired wild-type and knockout experiments can generate improved motifs but require optimal differential analysis. We introduce peaKO—a computational method to automatically optimize motif analyses with knockout controls, which we compare to two other methods. PeaKO often improves elucidation of the target factor and highlights the benefits of knockout controls, which far outperform input controls. It is freely available at https://peako.hoffmanlab.org.

Three on Three: Universal and High-Affinity Molecular Recognition of the Symmetric Homotrimeric Spike Protein of SARS-CoV-2 with a Symmetric Homotrimeric Aptamer

Our previously discovered monomeric aptamer for SARS-CoV-2 (MSA52) possesses a universal affinity for COVID-19 spike protein variants but is ultimately limited by its ability to bind only one subunit of the spike protein. The symmetrical shape of the homotrimeric SARS-CoV-2 spike protein presents the opportunity to create a matching homotrimeric molecular recognition element that is perfectly complementary to its structural scaffold, causing enhanced binding affinity. Here, we describe a branched homotrimeric aptamer with three-fold rotational symmetry, named TMSA52, that not only possesses excellent binding affinity but is also capable of binding several SARS-CoV-2 spike protein variants with picomolar affinity, as well as pseudotyped lentiviruses expressing SARS-CoV-2 spike protein variants with femtomolar affinity. Using Pd-Ir nanocubes as nanozymes in an enzyme-linked aptamer binding assay (ELABA), TMSA52 was capable of sensitively detecting diverse pseudotyped lentiviruses in pooled human saliva with a limit of detection as low as 6.3 × 103 copies/mL. The ELABA was also used to test 50 SARS-CoV-2-positive and 60 SARS-CoV-2-negative patient saliva samples, providing sensitivity and specificity values of 84.0 and 98.3%, respectively, thus highlighting the potential of TMSA52 for the development of future rapid tests.

Todurujo na Kadurok (empowering youth): study protocol of an HIV self-testing and edutainment comic cluster randomised trial among refugee youth in a humanitarian setting in Uganda

INTRODUCTION

Refugees experience HIV vulnerabilities due to the confluence of displacement, violence and poverty. HIV self-testing, understudied with refugees, is a promising method to increase testing uptake, yet challenges remain with linkages to confirmatory testing following a positive HIV self-test. This study aims to evaluate the effectiveness of HIV self-testing kits and 'edutainment' comics in increasing HIV testing and HIV status knowledge among refugee youth aged 16-24 years in Bidi Bidi Refugee Settlement, Uganda.

METHODS AND ANALYSIS

This study will be conducted in Bidi Bidi. We conducted a qualitative formative phase with focus groups (n=40) to generate knowledge of barriers and facilitators of HIV prevention, testing and care among refugee youth (aged 16-24) in Bidi Bidi. These findings were used to create comic scenarios aligning with edutainment approaches to health promotion and inform a four-arm cluster randomised controlled trial in Bidi Bidi using a 2×2 factorial design: (1) HIV self-testing alongside edutainment comics, (2) HIV self-testing alone, (3) edutainment comic alone and (4) standard of care. The target sample size will be 120 youth (30 per arm), who will be enrolled in the trial and followed for 3 months. Data will be collected at baseline and 3 months after enrolment. The primary outcomes (HIV testing frequency, HIV status knowledge) and secondary outcomes (linkage to confirmatory HIV testing, HIV care linkage, HIV self-test kit use, HIV-related stigma, HIV knowledge, safer sex efficacy, condom use, adolescent sexual and reproductive health (SRH) stigma, sexual relationship power, access to SRH services) will be evaluated using descriptive statistics and regression analyses.

ETHICS AND DISSEMINATION

This study was approved by the University of Toronto Research Ethics Board, Mildmay Uganda Research Ethics Committee and the Uganda National Council for Science and Technology. Results will be shared in peer-reviewed publications and community knowledge sharing.

TRIAL REGISTRATION NUMBER

NCT05213689.

Density Functional Theory Study on the Selective Reductive Amination of Aldehydes and Ketones over Their Reductions to Alcohols Using Sodium Triacetoxyborohydride

Reductive amination is one of the most important methods to synthesize amines, having a wide application in the pharmaceutical, fine chemicals, and materials industries. In general, the reaction begins with dehydration between a carbonyl compound and an amine compound, forming an imine, which is then reduced to an alkylated amine product. Sodium triacetoxyborohydride (STAB) is a popular choice for the reducing agent as it shows selectivity for imines over aldehydes and ketones, which is particularly important in direct reductive amination where the imine and carbonyl compounds are present concurrently. Here, we analyze the reaction pathways of acid-catalyzed direct reductive amination in 1,2-dichloroethane (DCE) with acetaldehyde and methylamine. We find that the transition states for the formation and subsequent reduction of Z-methylethylideneimine (resultant aldimine from acetaldehyde and methylamine) have lower energies than the reduction of acetaldehyde. Transition state structures for the hydride transfers are organized by the Lewis-acidic sodium ion. Additionally, reduction reactions with formaldehyde and acetone and their imine derivatives (with methylamine) are investigated, and again, the hydride transfer to the resultant aldimine or ketimine is lower in energy than that of their parent carbonyl compound.

Transcranial Direct Current Stimulation Over Motor Areas Improves Reaction Time in Parkinson's Disease

Background

Transcranial direct current stimulation (tDCS) has been shown to modulate cortical motor excitability and improve bradykinesia symptoms in Parkinson's disease. It is unclear how targeting different cortical motor areas with tDCS may differentially influence upper limb function for individuals diagnosed with PD.

Objective

This study investigated whether anodal tDCS applied separately to the primary motor cortex and the supplementary motor area would improve upper limb function for individuals with Parkinson's disease. In addition, a startling acoustic stimulus was used to differentiate between the effect of stimulation on motor preparatory and initiation processes associated with upper limb movements.

Methods

Eleven participants with idiopathic Parkinson's disease performed two upper limb simple reaction time tasks, involving elbow extension or a button press before and after either anodal tDCS or sham tDCS was applied over the primary motor cortex or supplementary motor area. A loud, startling stimulus was presented on a selection of trials to involuntarily trigger the prepared action.

Results

Anodal tDCS led to improved premotor reaction time in both tasks, but this was moderated by reaction time in pre-tDCS testing, such that individuals with slower pre-tDCS reaction time showed the greatest reaction time improvements. Startle-trial reaction time was not modified following tDCS, suggesting that the stimulation primarily modulated response initiation processes.

Conclusion

Anodal tDCS improved response initiation speed, but only in slower reacting individuals with PD. However, no differences attributable to tDCS were observed in clinical measures of bradykinesia or kinematic variables, suggesting that reaction time may represent a more sensitive measure of some components of bradykinesia.

Sensitivity of discrete symmetry metrics: Implications for metric choice

Gait asymmetry is present in several pathological populations, including those with Parkinson’s disease, Huntington’s disease, and stroke survivors. Previous studies suggest that commonly used discrete symmetry metrics, which compare single bilateral variables, may not be equally sensitive to underlying effects of asymmetry, and the use of a metric with low sensitivity could result in unnecessarily low statistical power. The purpose of this study was to provide a comprehensive assessment of the sensitivity of commonly used discrete symmetry metrics to better inform design of future studies. Monte Carlo simulations were used to estimate the statistical power of each symmetry metric at a range of asymmetry magnitudes, group/condition variabilities, and sample sizes. Power was estimated by repeated comparison of simulated symmetric and asymmetric data with a paired t-test, where the proportion of significant results is equivalent to the power. Simulation results confirmed that not all common discrete symmetry metrics are equally sensitive to reference effects of asymmetry. Multiple symmetry metrics exhibit equivalent sensitivities, but the most sensitive discrete symmetry metric in all cases is a bilateral difference (e.g. left—right). A ratio (e.g. left/right) has poor sensitivity when group/condition variability is not small, but a log-transformation produces increased sensitivity. Additionally, two metrics which included an absolute value in their definitions showed increased sensitivity when the absolute value was removed. Future studies should consider metric sensitivity when designing analyses to reduce the possibility of underpowered research.

Investigating acute changes in osteoarthritic cartilage by integrating biomechanics and statistical shape models of bone: data from the osteoarthritis initiative

Objective

Methods

Results

Discussion

Supplementary Information

Changes in Sensorimotor Connectivity to dI3 Interneurons in Relation to the Postnatal Maturation of Grasping

Primitive reflexes are evident shortly after birth. Many of these reflexes disappear during postnatal development as part of the maturation of motor control. This study investigates the changes of connectivity related to sensory integration by spinal dI3 interneurons during the time in which the palmar grasp reflex gradually disappears in postnatal mice pups. Our results reveal an increase in GAD65/67-labeled terminals to perisomatic Vglut1-labeled sensory inputs contacting cervical and lumbar dI3 interneurons between postnatal day 3 and day 25. In contrast, there were no changes in the number of perisomatic Vglut1-labeled sensory inputs to lumbar and cervical dI3 interneurons other than a decrease between postnatal day 15 and day 25. Changes in postsynaptic GAD65/67-labeled inputs to dI3 interneurons were inconsistent with a role in the sustained loss of the grasp reflex. These results suggest a possible link between the maturation of hand grasp during postnatal development and increased presynaptic inhibition of sensory inputs to dI3 interneurons.

Walking on Mild Slopes and Altering Arm Swing Each Induce Specific Strategies in Healthy Young Adults

Slopes are present in everyday environments and require specific postural strategies for successful navigation; different arm strategies may be used to manage external perturbations while walking. It has yet to be determined what impact arm swing has on postural strategies and gait stability during sloped walking. We investigated the potentially interacting effects of surface slope and arm motion on gait stability and postural strategies in healthy young adults. We tested 15 healthy adults, using the CAREN-Extended system to simulate a rolling-hills environment which imparted both incline (uphill) and decline (downhill) slopes (± 3°). This protocol was completed under three imposed arm swing conditions: held, normal, active. Spatiotemporal gait parameters, mediolateral margin of stability, and postural kinematics in anteroposterior (AP), mediolateral (ML), and vertical (VT) directions were assessed. Main effects of conditions and interactions were evaluated by 2-way repeated measures analysis of variance. Our results showed no interactions between arm swing and slope; however, we found main effects of arm swing and main effects of slope. As expected, uphill and downhill sections of the rolling-hills yielded opposite stepping and postural strategies compared to level walking, and active and held arm swings led to opposite postural strategies compared to normal arm swing. Arm swing effects were consistent across slope conditions. Walking with arms held decreased gait speed, indicating a level of caution, but maintained stability comparable to that of walking with normal arm swing. Active arm swing increased both step width variability and ML-MoS during downhill sections. Alternately, ML-MoS was larger with increased step width and double support time during uphill sections compared to level, which demonstrates that distinct base of support strategies are used to manage arm swing compared to slope. The variability of the rolling-hills also required proactive base of support changes despite the mild slopes to maintain balance.

Statistical Design of Biocarbon Reinforced Sustainable Composites from Blends of Polyphthalamide (PPA) and Polyamide 4,10 (PA410)

A full factorial design with four factors (the ratio of polyphthalamide (PPA) and polyamide 4,10 (PA410) in the polymer matrix, content percent of biocarbon (BioC), the temperature at which it was pyrolyzed and the presence of a chain extender (CE)), each factor with two levels (high and low), was carried out to optimize the mechanical properties of the resulting composites. After applying a linear model, changes in tensile strength, elongation at break and impact energy were not statistically significant within the considered material space, while the ones in the flexural modulus, the tensile modulus, density and heat deflection temperature (HDT) were. The two most influential factors were the content of BioC and its pyrolysis temperature, followed by the content of PPA. The affinity of PPA with a high-temperature biocarbon and the affinity of PA410 with a lower-temperature biocarbon, appear to explain the mechanical properties of the resulting composites. The study also revealed that the addition of CE hindered the mechanical properties. By maximizing the flexural modulus, tensile modulus and HDT, while minimizing the density, the optimal composite predicted is an 80 [PPA:PA410 (25:75)] wt% polymer composite, with 20 wt% of a BioC, pyrolyzed at a calculated 823 °C.

From tissue retrieval to electron tomography: nanoscale characterization of the interface between bone and bioactive glass

The success of biomaterials for bone regeneration relies on many factors, among which osseointegration plays a key role. Biogran (BG) is a bioactive glass commonly employed as a bone graft in dental procedures. Despite its use in clinical practice, the capability of BG to promote osseointegration has never been resolved at the nanoscale. In this paper, we present the workflow for characterizing the interface between newly formed bone and BG in a preclinical rat model. Areas of bone-BG contact were first identified by backscattered electron imaging in a scanning electron microscope. A focused ion beam in situ lift-out protocol was employed to prepare ultrathin samples for transmission electron microscopy analysis. The bone-BG gradual interface, i.e. the biointerphase, was visualized at the nanoscale with unprecedented resolution thanks to scanning transmission electron microscopy. Finally, we present a method to view the bone-BG interface in three dimensions using electron tomography.

Modulating the Thermoresponse of Polymer-Protein Conjugates with Hydrogels for Controlled Release

Sustained release is being explored to increase plasma and tissue residence times of polymer-protein therapeutics for improved efficacy. Recently, poly(oligo(ethylene glycol) methyl ether methacrylate) (PEGMA) polymers have been established as potential PEG alternatives to further decrease immunogenicity and introduce responsive or sieving properties. We developed a drug delivery system that locally depresses the lower critical solution temperature (LCST) of PEGMA-protein conjugates within zwitterionic hydrogels for controlled release. Inside the hydrogel the conjugates partially aggregate through PEGMA-PEGMA chain interactions to limit their release rates, whereas conjugates outside of the hydrogel are completely solubilized. Release can therefore be tuned by altering hydrogel components and the PEGMA's temperature sensitivity without the need for traditional controlled release mechanisms such as particle encapsulation or affinity interactions. Combining local LCST depression technology and degradable zwitterionic hydrogels, complete release of the conjugate was achieved over 13 days.

Self-assessment of Competence in Endoscopy: Challenges and Insights

BACKGROUND

Endoscopists use self-assessment to monitor the development and maintenance of their skills. The accuracy of these self-assessments, which reflects how closely one's own rating corresponds to an external rating, is unclear.

METHODS

In this narrative review, we critically examine the current literature on self-assessment in gastrointestinal endoscopy with the aim of informing training and practice and identifying opportunities to improve the methodological rigor of future studies.

RESULTS

In the seven included studies, the evidence regarding self-assessment accuracy was mixed. When stratified by experience level, however, novice endoscopists were least accurate in their self-assessments and tended to overestimate their performance. Studies examining the utility of video-based interventions using observation of expert benchmark performances show promise as a mechanism to improve self-assessment accuracy among novices.

CONCLUSIONS

Based on the results of this review, we highlight problematic areas, identify opportunities to improve the methodological rigor of future studies on endoscopic self-assessment and outline potential avenues for further exploration.

Development of HDAC Inhibitors Exhibiting Therapeutic Potential in T-Cell Prolymphocytic Leukemia

Epigenetic targeting has emerged as an efficacious therapy for hematological cancers. The rare and incurable T-cell prolymphocytic leukemia (T-PLL) is known for its aggressive clinical course. Current epigenetic agents such as histone deacetylase (HDAC) inhibitors are increasingly used for targeted therapy. Through a structure-activity relationship (SAR) study, we developed an HDAC6 inhibitor KT-531, which exhibited higher potency in T-PLL compared to other hematological cancers. KT-531 displayed strong HDAC6 inhibitory potency and selectivity, on-target biological activity, and a safe therapeutic window in nontransformed cell lines. In primary T-PLL patient cells, where HDAC6 was found to be overexpressed, KT-531 exhibited strong biological responses, and safety in healthy donor samples. Notably, combination studies in T-PLL patient samples demonstrated KT-531 synergizes with approved cancer drugs, bendamustine, idasanutlin, and venetoclax. Our work suggests HDAC inhibition in T-PLL could afford sufficient therapeutic windows to achieve durable remission either as stand-alone or in combination with targeted drugs.

Text mining to support abstract screening for knowledge syntheses: a semi-automated workflow

BACKGROUND

Current text mining tools supporting abstract screening in systematic reviews are not widely used, in part because they lack sensitivity and precision. We set out to develop an accessible, semi-automated "workflow" to conduct abstract screening for systematic reviews and other knowledge synthesis methods.

METHODS

We adopt widely recommended text-mining and machine-learning methods to (1) process title-abstracts into numerical training data; and (2) train a classification model to predict eligible abstracts. The predicted abstracts are screened by human reviewers for ("true") eligibility, and the newly eligible abstracts are used to identify similar abstracts, using near-neighbor methods, which are also screened. These abstracts, as well as their eligibility results, are used to update the classification model, and the above steps are iterated until no new eligible abstracts are identified. The workflow was implemented in R and evaluated using a systematic review of insulin formulations for type-1 diabetes (14,314 abstracts) and a scoping review of knowledge-synthesis methods (17,200 abstracts). Workflow performance was evaluated against the recommended practice of screening abstracts by 2 reviewers, independently. Standard measures were examined: sensitivity (inclusion of all truly eligible abstracts), specificity (exclusion of all truly ineligible abstracts), precision (inclusion of all truly eligible abstracts among all abstracts screened as eligible), F1-score (harmonic average of sensitivity and precision), and accuracy (correctly predicted eligible or ineligible abstracts). Workload reduction was measured as the hours the workflow saved, given only a subset of abstracts needed human screening.

RESULTS

With respect to the systematic and scoping reviews respectively, the workflow attained 88%/89% sensitivity, 99%/99% specificity, 71%/72% precision, an F1-score of 79%/79%, 98%/97% accuracy, 63%/55% workload reduction, with 12%/11% fewer abstracts for full-text retrieval and screening, and 0%/1.5% missed studies in the completed reviews.

CONCLUSION

The workflow was a sensitive, precise, and efficient alternative to the recommended practice of screening abstracts with 2 reviewers. All eligible studies were identified in the first case, while 6 studies (1.5%) were missed in the second that would likely not impact the review's conclusions. We have described the workflow in language accessible to reviewers with limited exposure to natural language processing and machine learning, and have made the code available to reviewers.

Association of six-minute walk test distance with postoperative complications in non-cardiac surgery: a secondary analysis of a multicentre prospective cohort study

PURPOSE

The six-minute walk test (6MWT) is a simple and valid test for assessing cardiopulmonary fitness. Nevertheless, the relationship between preoperative 6MWT distance and postoperative complications is uncertain. We conducted a secondary analysis of the 6MWT nested cohort substudy of the Measurement of Exercise Tolerance before Surgery study to determine if 6MWT distance predicts postoperative complications or death.

METHODS

This analysis included 545 adults (≥ 40 yr) who were at elevated cardiac risk and had elective inpatient non-cardiac surgery at 15 hospitals in Canada, Australia, and New Zealand. Each participant performed a preoperative 6MWT and was followed for 30 days after surgery. The primary outcome was moderate or severe in-hospital complications. The secondary outcome was 30-day death or myocardial injury. Multivariable logistic regression modelling was used to characterize the adjusted association of 6MWT distance with these outcomes.

RESULTS

Seven participants (1%) terminated their 6MWT sessions early because of lower limb pain, dyspnea, or dizziness. Eighty-one (15%) participants experienced moderate or severe complications and 69 (13%) experienced 30-day myocardial injury or death. Decreased 6MWT distance was associated with increased odds of moderate or severe complications (adjusted odds ratio, 1.32 per 100 m decrease; 95% confidence interval, 1.01 to 1.73; P = 0.045). There was no association of 6MWT distance with myocardial injury or 30-day death (non-linear association; P = 0.49).

CONCLUSION

Preoperative 6MWT distance had a modest association with moderate or severe complications after inpatient non-cardiac surgery. Further studies are needed to determine the optimal role of the 6MWT as an objective exercise test for informing preoperative risk stratification.

Regularity of kinematic data between single and dual-task treadmill walking in people with Parkinson's disease

BACKGROUND

Regularity, quantified by sample entropy (SampEn), has been extensively used as a gait stability measure. Yet, there is no consensus on the calculation process and variant approaches, e.g. single-scale SampEn with and without incorporating a time delay greater than one, multiscale SampEn, and complexity index, have been used to calculate the regularity of kinematic or kinetic signals. The aim of the present study was to test the discriminatory performance of the abovementioned approaches during single and dual-task walking in people with Parkinson's disease (PD).

METHODS

Seventeen individuals with PD were included in this study. Participants completed two walking trials that included single and dual-task conditions. The secondary task was word searching with twelve words randomly appearing in the participants' visual field. Trunk linear acceleration at sternum level, linear acceleration of the center of gravity, and angular velocity of feet, shanks, and thighs, each in three planes of motion were collected. The regularity of signals was computed using approaches mentioned above for single and dual-task conditions.

RESULTS

Incorporating a time delay greater than one and considering multiple scales helped better distinguish between single and dual-task walking. For all signals, the complexity index, defined as the summary of multiscale SampEn analysis, was the most efficient discriminatory index between single-task walking and dual-tasking in people with Parkinson's disease. Specifically, the complexity index of the trunk linear acceleration of the center of gravity distinguished between the two walking conditions in all three planes of motion.

CONCLUSIONS

The significant results observed across the 24 signals studied in this study are illustrative examples of the complexity index's potential as a gait feature for classifying different walking conditions.

Fluorine-18-Labeled Fluorescent Dyes for Dual-Mode Molecular Imaging

Recent progress realized in the development of optical imaging (OPI) probes and devices has made this technique more and more affordable for imaging studies and fluorescence-guided surgery procedures. However, this imaging modality still suffers from a low depth of penetration, thus limiting its use to shallow tissues or endoscopy-based procedures. In contrast, positron emission tomography (PET) presents a high depth of penetration and the resulting signal is less attenuated, allowing for imaging in-depth tissues. Thus, association of these imaging techniques has the potential to push back the limits of each single modality. Recently, several research groups have been involved in the development of radiolabeled fluorophores with the aim of affording dual-mode PET/OPI probes used in preclinical imaging studies of diverse pathological conditions such as cancer, Alzheimer's disease, or cardiovascular diseases. Among all the available PET-active radionuclides, 18F stands out as the most widely used for clinical imaging thanks to its advantageous characteristics (t1/2 = 109.77 min; 97% β+ emitter). This review focuses on the recent efforts in the synthesis and radiofluorination of fluorescent scaffolds such as 4,4-difluoro-4-bora-diazaindacenes (BODIPYs), cyanines, and xanthene derivatives and their use in preclinical imaging studies using both PET and OPI technologies.

FOCAL3D: A 3-dimensional clustering package for single-molecule localization microscopy

Single-molecule localization microscopy (SMLM) is a powerful tool for studying intracellular structure and macromolecular organization at the nanoscale. The increasingly massive pointillistic data sets generated by SMLM require the development of new and highly efficient quantification tools. Here we present FOCAL3D, an accurate, flexible and exceedingly fast (scaling linearly with the number of localizations) density-based algorithm for quantifying spatial clustering in large 3D SMLM data sets. Unlike DBSCAN, which is perhaps the most commonly employed density-based clustering algorithm, an optimum set of parameters for FOCAL3D may be objectively determined. We initially validate the performance of FOCAL3D on simulated datasets at varying noise levels and for a range of cluster sizes. These simulated datasets are used to illustrate the parametric insensitivity of the algorithm, in contrast to DBSCAN, and clustering metrics such as the F1 and Silhouette score indicate that FOCAL3D is highly accurate, even in the presence of significant background noise and mixed populations of variable sized clusters, once optimized. We then apply FOCAL3D to 3D astigmatic dSTORM images of the nuclear pore complex (NPC) in human osteosaracoma cells, illustrating both the validity of the parameter optimization and the ability of the algorithm to accurately cluster complex, heterogeneous 3D clusters in a biological dataset. FOCAL3D is provided as an open source software package written in Python.

We have developed an accurate, highly-efficient and flexible algorithm for quantifying spatial clustering in large, 3-dimensional single-molecule localization microscopy (SMLM) datasets. Our method, FOCAL3D, is provided as an open-source software package written in Python. FOCAL3D scales linearly with the number of localizations and the algorithmic parameters may be systematically optimized so that the resulting analysis is insensitive to variation over a range of parameter choices. We initially validate the performance and parametric insensitivity of FOCAL3D on simulated datasets, then apply the algorithm to 3-dimensional, astigmatic dSTORM images of the nuclear pore complex in human osteosarcoma cells.

Conceptualizing LGBT Stigma and Associated HIV Vulnerabilities Among LGBT Persons in Lesotho

Social marginalization harms lesbian, gay, bisexual, and transgender (LGBT) persons’ wellbeing in Lesotho. Socio-cultural mechanisms linking LGBT stigma, depression, substance use, and HIV among LGBT persons in Lesotho are understudied. We explore associations between LGBT stigma, mental health stressors, and HIV vulnerabilities among LGBT persons in Lesotho. We conducted in-depth, semi-structured interviews with 46 LGBT persons and six key informants (e.g. healthcare providers). Participants described depression, substance use, and HIV as mutually reinforcing and situated in larger social contexts of stigma. Alcohol use was a stigma coping strategy and a way to build LGBT connections. At the same time, alcohol use elevated HIV vulnerabilities by lowering condom use uptake. Pervasive stigma reinforced barriers to healthcare engagement. Community-led support and services were leveraged to navigate stigma, reduce HIV vulnerabilities, and ultimately improve health. Findings emphasize the key role contexts play in shaping sexual and mental health among LGBT persons in Lesotho.

The role of drug treatment and recovery services: an opportunity to address injection initiation assistance in Tijuana, Mexico

BACKGROUND

In the U.S. and Canada, people who inject drugs' (PWID) enrollment in medication-assisted treatment (MAT) has been associated with a reduced likelihood that they will assist others in injection initiation events. We aimed to qualitatively explore PWID's experiences with MAT and other drug treatment and related recovery services in Tijuana Mexico, a resource-limited setting disproportionately impacted by injection drug use.

METHODS

PReventing Injecting by Modifying Existing Responses (PRIMER) seeks to assess socio-structural factors associated with PWID provision of injection initiation assistance. This analysis drew on qualitative data from Proyecto El Cuete (ECIV), a Tijuana-based PRIMER-linked cohort study. In-depth qualitative interviews were conducted with a subset of study participants to further explore experiences with MAT and other drug treatment services. Qualitative thematic analyses examined experiences with these services, including MAT enrollment, and related experiences with injection initiation assistance provision.

RESULTS

At PRIMER baseline, 607(81.1%) out of 748 participants reported recent daily IDU, 41(5.5%) reported recent injection initiation assistance, 92(12.3%) reported any recent drug treatment or recovery service access, and 21(2.8%) reported recent MAT enrollment (i.e., methadone). Qualitative analysis (n = 21; female = 8) revealed that, overall, abstinence-based recovery services did not meet participants' recovery goals, with substance use-related social connections in these contexts potentially shaping injection initiation assistance. Themes also highlighted individual-level (i.e., ambivalence and MAT-related stigma) and structural-level (i.e., cost and availability) barriers to MAT enrollment.

CONCLUSION

Tijuana's abstinence-based drug treatment and recovery services were viewed as unable to meet participants' recovery-related goals, which could be limiting the potential benefits of these services. Drug treatment and recovery services, including MAT, need to be modified to improve accessibility and benefits, like preventing transitions into drug injecting, for PWID.

Defining pain and interference recovery trajectories after acute non-catastrophic musculoskeletal trauma through growth mixture modeling

BACKGROUND

Recovery trajectories support early identification of delayed recovery and can inform personalized management or phenotyping of risk profiles in patients. The objective of this study was to investigate the trajectories in pain severity and functional interference following non-catastrophic musculoskeletal (MSK) trauma in an international, mixed injury sample.

METHODS

A prospective longitudinal cohort (n = 241) was formed from patients identified within four weeks of trauma, from attendance at emergency or urgent care centres located in London, ON, Canada, or Chicago, IL, USA. Pain interference was measured via the Brief Pain Inventory (London cohort) or the Neck Disability Index (Chicago cohort). Pain severity was captured in both cohorts using the numeric pain rating scale. Growth mixture modeling and RM repeated measures ANOVA approaches identified distinct trajectories of recovery within pain interference and pain severity data.

RESULTS

For pain interference, the three trajectories were labeled accordingly: Class 1 = Rapid recovery (lowest intercept, full or near full recovery by 3 months, 32.0% of the sample); Class 2 = Delayed recovery (higher intercept, recovery by 12 months, 26.7% of the sample); Class 3 = Minimal or no recovery (higher intercept, persistently high interference scores at 12 months, 41.3% of the sample). For pain severity, the two trajectories were labeled: Class 1 = Rapid recovery (lower intercept, recovery by 3 months, 81.3% of the sample); and Class 2 = Minimal or no recovery (higher intercept, flat curve, 18.7% of the sample). The "Minimal or No Recovery" trajectory could be predicted by female sex and axial (vs. peripheral) region of trauma with 74.3% accuracy across the 3 classes for the % Interference outcome. For the Pain Severity outcome, only region (axial trauma, 81.3% accuracy) predicted the "Minimal or No Recovery" trajectory.

CONCLUSIONS

These results suggest that three meaningful recovery trajectories can be identified in an international, mixed-injury sample when pain interference is the outcome, and two recovery trajectories emerge when pain severity is the outcome. Females in the sample or people who suffered axial injuries (head, neck, or low back) were more likely to be classed in poor outcome trajectories.

TRIAL REGISTRATION

National Institutes of Health - clinicaltrials.gov ( NCT02711085 ; Retrospectively registered Mar 17, 2016).

Flash Solid-Solid Synthesis of Silicon Oxide Nanorods

1D silicon-based nanomaterials, renowned for their unique chemical and physical properties, have enabled the development of numerous advanced materials and biomedical technologies. Their production often necessitates complex and expensive equipment, requires hazardous precursors and demanding experimental conditions, and involves lengthy processes. Herein, a flash solid-solid (FSS) process is presented for the synthesis of silicon oxide nanorods completed within seconds. The innovative features of this FSS process include its simplicity, speed, and exclusive use of solid precursors, comprising hydrogen-terminated silicon nanosheets and a metal nitrate catalyst. Advanced electron microscopy and X-ray spectroscopy analyses favor a solid-liquid-solid reaction pathway for the growth of the silicon oxide nanorods with vapor-liquid-solid characteristics.

Contextual factors associated with depression among urban refugee and displaced youth in Kampala, Uganda: findings from a cross-sectional study

BACKGROUND

Advancing mental health among refugee and displaced adolescents and youth is critically important, as chronic psychological stress can have lifelong harmful impacts. These groups experience socio-environmental stressors that can harm mental health. Informed by a social contextual framework, this study explored the prevalence of depression among urban refugee and displaced youth in Kampala, Uganda and associations with symbolic (violence), relational (social support), and material (food and community insecurity) contexts.

METHODS

We implemented a cross-sectional survey with refugee and displaced adolescent girls and young women and adolescent boys and young men aged 16-24 living in Kampala's informal settlements. We conducted peer-driven recruitment, whereby peer navigators shared study information with their networks and in turn participants were invited to recruit their peers. We conducted gender disaggregated analyses, including stepwise multiple regression to examine factors associated with depression. We then conducted structural equation modeling (SEM) using weighted least squares estimation to examine direct paths from violence, food insecurity, and community insecurity to depression, and indirect effects through social support.

RESULTS

Among participants (n = 445), young women (n = 333) reported significantly higher depression symptoms than young men (n = 112), including any symptoms (73.9% vs. 49.1%, p < 0.0001), mild to moderate symptoms (60.4% vs. 45.5%, p = 0.008), and severe symptoms (13.5% vs 3.6%, p = 0.002). SEM results among young women indicate that the latent violence factor (lifetime sexual and physical violence) had direct effects on depression and social support, but social support did not mediate the path from violence to depression. The model fit the data well: χ2(3) = 9.82, p = 0.020; RMSEA = 0.08, 90% CI [0.03, 0.14], CFI = 0.96). Among young men, SEM findings indicate that food insecurity had direct effects on social support, and an indirect effect on depression through the mediating role of social support. Fit indices suggest good model fit: χ2(3) = 2.09, p = 0.352; RMSEA = 0.02, 90% CI [0.000, 0.19], CFI = 0.99.

CONCLUSIONS

Findings reveal widespread depression among urban refugee and displaced youth in Kampala, disproportionately impacting young women. Contextual factors, including food insecurity and violence, increase depression risks. Strategies that reduce gender-based violence and food insecurity, and increase social support networks, have the potential to promote mental health among urban refugee and displaced youth.

Recent Advances in Monitoring Cell Behavior Using Cell-Based Impedance Spectroscopy

Cell-based impedance spectroscopy (CBI) is a powerful tool that uses the principles of electrochemical impedance spectroscopy (EIS) by measuring changes in electrical impedance relative to a voltage applied to a cell layer. CBI provides a promising platform for the detection of several properties of cells including the adhesion, motility, proliferation, viability and metabolism of a cell culture. This review gives a brief overview of the theory, instrumentation, and detection principles of CBI. The recent applications of the technique are given in detail for research into cancer, neurodegenerative diseases, toxicology as well as its application to 2D and 3D in vitro cell cultures. CBI has been established as a biophysical marker to provide quantitative cellular information, which can readily be adapted for single-cell analysis to complement the existing biomarkers for clinical research on disease progression.

A R2R3-MYB gene-based marker for the non-darkening seed coat trait in pinto and cranberry beans (Phaseolus vulgaris L.) derived from 'Wit-rood boontje'

KEY MESSAGE

The gene Phvul.010G130600 which codes for a MYB was shown to be tightly associated with seed coat darkening in Phaseolus vulgaris and a single nucleotide deletion in the allele in Wit-rood disrupts a transcription activation region that likely prevents its functioning in this non-darkening genotype. The beige and white background colors of the seed coats of conventional pinto and cranberry beans turn brown through a process known as postharvest darkening (PHD). Seed coat PHD is attributed to proanthocyanidin accumulation and its subsequent oxidation in the seed coat. The J gene is an uncharacterized classical genetic locus known to be responsible for PHD in common bean (P. vulgaris) and individuals that are homozygous for its recessive allele have a non-darkening (ND) seed coat phenotype. A previous study identified a major colorimetrically determined QTL for seed coat color on chromosome 10 that was associated with the ND trait. The objectives of this study were to identify a gene associated with seed coat postharvest darkening in common bean and understand its function in promoting seed coat darkening. Amplicon sequencing of 21 candidate genes underlying the QTL associated with the ND trait revealed a single nucleotide deletion (c.703delG) in the candidate gene Phvul.010G130600 in non-darkening recombinant inbred lines derived from crosses between ND 'Wit-rood boontje' and a regular darkening pinto genotype. In silico analysis indicated that Phvul.010G130600 encodes a protein with strong amino acid sequence identity (70%) with a R2R3-MYB-type transcription factor MtPAR, which has been shown to regulate proanthocyanidin biosynthesis in Medicago truncatula seed coat tissue. The deletion in the 'Wit-rood boontje' allele of Phvul.010G130600 likely causes a translational frame shift that disrupts the function of a transcriptional activation domain contained in the C-terminus of the R2R3-MYB. A gene-based dominant marker was developed for the dominant allele of Phvul.010G130600 which can be used for marker-assisted selection of ND beans.

BOLD and GenBank revisited - Do identification errors arise in the lab or in the sequence libraries?

Applications of biological knowledge, such as forensics, often require the determination of biological materials to a species level. As such, DNA-based approaches to identification, particularly DNA barcoding, are attracting increased interest. The capacity of DNA barcodes to assign newly encountered specimens to a species relies upon access to informatics platforms, such as BOLD and GenBank, which host libraries of reference sequences and support the comparison of new sequences to them. As parameterization of these libraries expands, DNA barcoding has the potential to make valuable contributions in diverse applied contexts. However, a recent publication called for caution after finding that both platforms performed poorly in identifying specimens of 17 common insect species. This study follows up on this concern by asking if the misidentifications reflected problems in the reference libraries or in the query sequences used to test them. Because this reanalysis revealed that missteps in acquiring and analyzing the query sequences were responsible for most misidentifications, a workflow is described to minimize such errors in future investigations. The present study also revealed the limitations imposed by the lack of a polished species-level taxonomy for many groups. In such cases, applications can be strengthened by mapping the geographic distributions of sequence-based species proxies rather than waiting for the maturation of formal taxonomic systems based on morphology.

A mathematical model describing the localization and spread of influenza A virus infection within the human respiratory tract

Within the human respiratory tract (HRT), virus diffuses through the periciliary fluid (PCF) bathing the epithelium. But virus also undergoes advection: as the mucus layer sitting atop the PCF is pushed along by the ciliated cell's beating cilia, the PCF and its virus content are also pushed along, upwards towards the nose and mouth. While many mathematical models (MMs) have described the course of influenza A virus (IAV) infections in vivo, none have considered the impact of both diffusion and advection on the kinetics and localization of the infection. The MM herein represents the HRT as a one-dimensional track extending from the nose down towards the lower HRT, wherein stationary cells interact with IAV which moves within (diffusion) and along with (advection) the PCF. Diffusion was found to be negligible in the presence of advection which effectively sweeps away IAV, preventing infection from disseminating below the depth at which virus first deposits. Higher virus production rates (10-fold) are required at higher advection speeds (40 μm/s) to maintain equivalent infection severity and timing. Because virus is entrained upwards, upper parts of the HRT see more virus than lower parts. As such, infection peaks and resolves faster in the upper than in the lower HRT, making it appear as though infection progresses from the upper towards the lower HRT, as reported in mice. When the spatial MM is expanded to include cellular regeneration and an immune response, it reproduces tissue damage levels reported in patients. It also captures the kinetics of seasonal and avian IAV infections, via parameter changes consistent with reported differences between these strains, enabling comparison of their treatment with antivirals. This new MM offers a convenient and unique platform from which to study the localization and spread of respiratory viral infections within the HRT.

Benchtop-fabricated lipid-based electrochemical sensing platform for the detection of membrane disrupting agents

There are increasing concerns about the danger that water-borne pathogens and pollutants pose to the public. Of particular importance are those that disrupt the plasma membrane, since loss of membrane integrity can lead to cell death. Currently, quantitative assays to detect membrane-disrupting (lytic) agents are done offsite, leading to long turnaround times and high costs, while existing colorimetric point-of-need solutions often sacrifice sensitivity. Thus, portable and highly sensitive solutions are needed to detect lytic agents for health and environmental monitoring. Here, a lipid-based electrochemical sensing platform is introduced to rapidly detect membrane-disrupting agents. The platform combines benchtop fabricated microstructured electrodes (MSEs) with lipid membranes. The sensing mechanism of the lipid-based platform relies on stacked lipid membranes serving as passivating layers that when disrupted generate electrochemical signals proportional to the membrane damage. The MSE topography, membrane casting and annealing conditions were optimized to yield the most reproducible and sensitive devices. We used the sensors to detect membrane-disrupting agents sodium dodecyl sulfate and Polymyxin-B within minutes and with limits of detection in the ppm regime. This study introduces a platform with potential for the integration of complex membranes on MSEs towards the goal of developing Membrane-on-Chip sensing devices.

Evaluating networked drug checking services in Toronto, Ontario: study protocol and rationale

BACKGROUND

The increasing incidence of fatal opioid overdose is a public health crisis in Canada. Given growing consensus that this crisis is related to the presence of highly potent opioid adulterants (e.g., fentanyl) in the unregulated drug supply, drug checking services (DCS) have emerged as part of a comprehensive approach to overdose prevention. In Canada's largest city, Toronto, a network of DCS launched in 2019 to prevent overdose and overdose-related risk behaviors. This network employs mass spectrometry technologies, with intake sites co-located with supervised consumption services (SCS) at three frontline harm reduction agencies. The protocol and rationale for assessing the impact of this multi-site DCS network in Toronto is described herein. The aims of this study are to (1) evaluate the impact of DCS access on changes in and factors influencing overdose and related risk behaviors, (2) investigate the perceived capacity of DCS to prevent overdose, and (3) identify composition (qualitative and quantitative) trends in Toronto's unregulated drug supply.

METHODS

We will use a parallel-mixed-methods design with complementary data sources (including data from chemical analysis of drug samples, quantitative intake and post-test surveys, SCS, coroners, paramedic services, and qualitative interviews), followed by a meta-inference process wherein results from analyses are synthesized.

RESULTS

Whereas most DCS globally target "recreational drug users," in Toronto, this networked DCS will primarily target marginalized people who use drugs accessing frontline services, many of whom use drugs regularly and by injection. This evolution in the application of DCS poses important questions that have not yet been explored, including optimal service delivery models and technologies, as well as unique barriers for this population. Increasing information on the unregulated drug supply may modify the risk environment for this population of people who use drugs.

CONCLUSIONS

This study addresses evidence gaps on the emerging continuum of overdose prevention responses and will generate critical evidence on a novel approach to reducing the ongoing high incidence of drug-related morbidity and mortality in Canada and elsewhere.

Social ecological factors associated with experiencing violence among urban refugee and displaced adolescent girls and young women in informal settlements in Kampala, Uganda: a cross-sectional study

BACKGROUND

Research on violence targeting urban forcibly displaced adolescent girls and young women (AGYW) is limited, particularly regarding polyvictimization (exposure to multiple forms of violence). Yet there is a global trend of refugee urbanization, and urban AGYW are at the nexus of violence disparities among adolescents, forcibly displaced persons, and slum dwellers. This study explored factors associated with young adulthood violence (> 16 years) (YAV) and intimate partner violence (IPV) among forcibly displaced AGYW in Kampala, Uganda.

METHODS

We conducted a cross-sectional survey with forcibly displaced AGYW aged 16-24 from five informal settlement (slum) communities across Kampala (Kabalagala, Rubaga, Kansanga, Katwe, Nsambya) using peer network sampling. We assessed YAV (experienced at age 16 or above) (sexual, physical, emotional violence) and recent (past 12-month) IPV (physical, sexual, control violence). We conducted descriptive statistics, followed by multinomial logistic regression analyses to explore social ecological factors (e.g., intrapersonal: depression; interpersonal: sexual relationship power, community: food insecurity) associated with experiencing YAV and YAV polyvictimization, and IPV and IPV polyvictimization.

RESULTS

Over half of participants (n = 333; mean age = 19.31; SD = 2.56, range = 16-24) reported YAV (n = 179; 53.7%) and 9.3% (n = 41) reported YAV polyvictimization. Most participants that were in an intimate relationship in the last 12 months (n = 200; 85.8%) reported IPV, among these, 45.5% reported one form of IPV and 54.5% reported IPV polyvictimization. In adjusted analyses, experiencing any YAV was significantly associated with: adolescent sexual and reproductive health (SRH) stigma; sexual relationship power; mobile app usage; depressive symptoms; childhood abuse; and childhood polyvictimization. In adjusted analyses YAV polyvictimization was associated with: depressive symptoms; childhood polyvictimization; sexual relationship power; and food insecurity. Recent IPV polyvictimization in adjusted analyses was associated with owning/using a mobile phone and depressive symptoms. Participants with higher sexual relationship power had lower odds of recent IPV polyvictimization.

CONCLUSION

Findings suggest that YAV and IPV polyvictimization require urgent attention among forcibly displaced AGYW in Kampala. Multi-level strategies are required to address intrapersonal e.g. (depression), interpersonal (e.g. childhood abuse, sexual relationship power) and community (e.g. adolescent SRH stigma, food insecurity) factors associated with experiencing violence. Future research can tailor approaches to advance health, agency and human rights among urban forcibly displaced AGYW.

Comparative effectiveness and safety of pharmacological and non-pharmacological interventions for insomnia: an overview of reviews

BACKGROUND

This review aimed to assess the existing evidence regarding the clinical effectiveness and safety of pharmacological and non-pharmacological interventions in adults with insomnia and identify where research or policy development is needed.

METHODS

MEDLINE, Embase, PsycINFO, The Cochrane Library, and PubMed were searched from inception until June 14, 2017, along with relevant gray literature sites. Two reviewers independently screened titles/abstracts and full-text articles, and a single reviewer with an independent verifier completed charting, data abstraction, and quality appraisal.

RESULTS

A total of 64 systematic reviews (35 with meta-analysis) were included after screening 5024 titles and abstracts and 525 full-text articles. Eight of the included reviews were rated as high quality using the Assessment of Multiple Systematic Reviews 2 (AMSTAR2) tool, and over half of the included articles (n = 40) were rated as low or critically low quality. Consistent evidence of effectiveness across multiple outcomes based on more than one high- or moderate quality review with meta-analysis was found for zolpidem, suvorexant, doxepin, melatonin, and cognitive behavioral therapy (CBT), and evidence of effectiveness across multiple outcomes based on one high-quality review with meta-analysis was found for temazepam, triazolam, zopiclone, trazodone, and behavioral interventions. These interventions were mostly evaluated in the short term (< 16 weeks), and there was very little harms data available for the pharmacological interventions making it difficult to evaluate their risk-benefit ratio.

CONCLUSIONS

Assuming non-pharmacological interventions are preferable from a safety perspective CBT can be considered an effective first-line therapy for adults with insomnia followed by other behavioral interventions. Short courses of pharmacological interventions can be supplements to CBT or behavioral therapy; however, no evidence regarding the appropriate duration of pharmacological therapy is available from these reviews.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017072527.

Genome-wide association analysis for β-hydroxybutyrate concentration in Milk in Holstein dairy cattle

BACKGROUND

Ketosis in dairy cattle has been shown to cause a high morbidity in the farm and substantial financial losses to dairy farmers. Ketosis symptoms, however, are difficult to identify, therefore, the amount of ketone bodies (mainly β-hydroxybutyric acid, BHB) is used as an indicator of subclinical ketosis in cows. It has also been shown that milk BHB concentrations have a strong correlation with ketosis in dairy cattle. Mid-infrared spectroscopy (MIR) has recently became a fast, cheap and high-throughput method for analyzing milk components. The aim of this study was to perform a genome-wide association study (GWAS) on the MIR-predicted milk BHB to identify genomic regions, genes and pathways potentially affecting subclinical ketosis in North American Holstein dairy cattle.

RESULTS

Several significant regions were identified associated with MIR-predicted milk BHB concentrations (indicator of subclinical ketosis) in the first lactation (SCK1) and second and later lactations (SCK2) in Holstein dairy cows. The strongest association was located on BTA6 for SCK1 and BTA14 on SCK2. Several SNPs on BTA6 were identified in regions and variants reported previously to be associated with susceptibility to ketosis and clinical mastitis in Jersey and Holstein dairy cattle, respectively. One highly significant SNP on BTA14 was found within the DGAT1 gene with known functions on fat metabolism and inflammatory response in dairy cattle. A region on BTA6 and three SNPs on BTA20 were found to overlap between SCK1 and SCK2. However, a novel region on BTA20 (55-63 Mb) for SCK2 was also identified, which was not reported in previous association studies. Enrichment analysis of the list of candidate genes within the identified regions for MIR-predicted milk BHB concentrations yielded molecular functions and biological processes that may be involved in the inflammatory response and lipid metabolism in dairy cattle.

CONCLUSIONS

The results of this study confirmed several SNPs and genes identified in previous studies as associated with ketosis susceptibility and immune response, and also found a novel region that can be used for further analysis to identify causal variations and key regulatory genes that affect clinical/ subclinical ketosis.

MagA expression attenuates iron export activity in undifferentiated multipotent P19 cells

Magnetic resonance imaging (MRI) is a non-invasive imaging modality used in longitudinal cell tracking. Previous studies suggest that MagA, a putative iron transport protein from magnetotactic bacteria, is a useful gene-based magnetic resonance contrast agent. Hemagglutinin-tagged MagA was stably expressed in undifferentiated embryonic mouse teratocarcinoma, multipotent P19 cells to provide a suitable model for tracking these cells during differentiation. Western blot and immunocytochemistry confirmed the expression and membrane localization of MagA in P19 cells. Surprisingly, elemental iron analysis using inductively-coupled plasma mass spectrometry revealed significant iron uptake in both parental and MagA-expressing P19 cells, cultured in the presence of iron-supplemented medium. Withdrawal of this extracellular iron supplement revealed unexpected iron export activity in P19 cells, which MagA expression attenuated. The influence of iron supplementation on parental and MagA-expressing cells was not reflected by longitudinal relaxation rates. Measurement of transverse relaxation rates (R₂* and R₂) reflected changes in total cellular iron content but did not clearly distinguish MagA-expressing cells from the parental cell type, despite significant differences in the uptake and retention of total cellular iron. Unlike other cell types, the reversible component R₂′ (R₂* ‒ R₂) provided only a moderately strong correlation to amount of cellular iron, normalized to amount of protein. This is the first report to characterize MagA expression in a previously unrecognized iron exporting cell type. The interplay between contrast gene expression and systemic iron metabolism substantiates the potential for diverting cellular iron toward the formation of a novel iron compartment, however rudimentary when using a single magnetotactic bacterial gene expression system like magA. Since relatively few mammalian cells export iron, the P19 cell line provides a tractable model of ferroportin activity, suitable for magnetic resonance analysis of key iron-handling activities and their influence on gene-based MRI contrast.

Class A scavenger receptor expression and function in eight novel tadpole cell lines from the green frog (Lithobates clamitans) and the wood frog (Lithobates sylvatica)

A total of eight tadpole cell lines were established from green frogs (Lithobates clamitans) and wood frogs (Lithobates sylvatica). The five green frog cell lines were named GreenTad-HF1, GreenTad-HF2, GreenTad-HF3, GreenTad-HE4, and GreenTad-gill. The three wood frog cell lines were named WoodTad-HE1, WoodTad-Bone, and WoodTad-rpe. DNA barcoding confirmed the cell lines to be from the correct species and the growth characteristics (optimal temperature and FBS requirement) were elucidated. In order to begin studying the innate immune capacity for each cell line, class A scavenger receptor expression and function were next explored. All cell lines expressed genes for at least 3 of the 5 class A scavenger receptor (SR-A) family members, but the gene expression patterns varied between cell lines. MARCO was only expressed in GreenTad-HE4 and WoodTad-Bone, while only GreenTad-HF3 did not express SCARA5 and only WoodTad-rpe did not express SR-AI. Acetylated low density lipoprotein (AcLDL) is a well-defined ligand for SR-As and WoodTad-rpe was the only cell line to which it was unable to bind. In the other seven tadpole cell lines, the SR-A competitive ligands (dextran sulfate, fucoidan, polyinosinic acid) blocked AcLDL binding whereas the SR-A non-competitive ligand counterparts (chondroitin sulfate, fetuin, polycytidylic acid, respectively) did not. Overall, these new eight cell lines can become important tools in the study of innate immunity in general and SR-A functions in particular in green frogs and wood frogs.

Government policy interventions to reduce human antimicrobial use: A systematic review and evidence map

BACKGROUND

Growing political attention to antimicrobial resistance (AMR) offers a rare opportunity for achieving meaningful action. Many governments have developed national AMR action plans, but most have not yet implemented policy interventions to reduce antimicrobial overuse. A systematic evidence map can support governments in making evidence-informed decisions about implementing programs to reduce AMR, by identifying, describing, and assessing the full range of evaluated government policy options to reduce antimicrobial use in humans.

METHODS AND FINDINGS

Seven databases were searched from inception to January 28, 2019, (MEDLINE, CINAHL, EMBASE, PAIS Index, Cochrane Central Register of Controlled Trials, Web of Science, and PubMed). We identified studies that (1) clearly described a government policy intervention aimed at reducing human antimicrobial use, and (2) applied a quantitative design to measure the impact. We found 69 unique evaluations of government policy interventions carried out across 4 of the 6 WHO regions. These evaluations included randomized controlled trials (n = 4), non-randomized controlled trials (n = 3), controlled before-and-after designs (n = 7), interrupted time series designs (n = 25), uncontrolled before-and-after designs (n = 18), descriptive designs (n = 10), and cohort designs (n = 2). From these we identified 17 unique policy options for governments to reduce the human use of antimicrobials. Many studies evaluated public awareness campaigns (n = 17) and antimicrobial guidelines (n = 13); however, others offered different policy options such as professional regulation, restricted reimbursement, pay for performance, and prescription requirements. Identifying these policies can inform the development of future policies and evaluations in different contexts and health systems. Limitations of our study include the possible omission of unpublished initiatives, and that policies not evaluated with respect to antimicrobial use have not been captured in this review.

CONCLUSIONS

To our knowledge this is the first study to provide policy makers with synthesized evidence on specific government policy interventions addressing AMR. In the future, governments should ensure that AMR policy interventions are evaluated using rigorous study designs and that study results are published.

PROTOCOL REGISTRATION

PROSPERO CRD42017067514.

Visual processing is diminished during movement execution

Recent research has suggested that visual discrimination and detection may be enhanced during movement preparation and execution, respectively. The current study examined if visual perceptual processing is augmented prior to or during a movement through the use of an Inspection Time (IT) task. The IT task involved briefly presenting (e.g., 15-105 ms) a "pi" figure with differing leg lengths, which was then immediately masked for 400 ms to prevent retinal afterimages. Participants were subsequently required to choose which of the two legs was longer. In Experiment 1, participants (n = 28) completed the IT task under three movement conditions: no-movement (NM), foreperiod (FP), and peak velocity (PV). In the NM condition, participants solely engaged in the IT paradigm. In the FP condition, the IT stimulus was presented prior to movement execution when response planning was expected to occur. Finally, in the PV condition, participants made a rapid movement to a target, and the IT stimulus was presented when their limb reached peak velocity. In Experiment 2, participants (n = 18) also performed the IT task in the PV and NM condition; however, vision of the limb's motion was made available during the PV trials (PV-FV) to investigate the potential influence of visual feedback on IT performance. Results showed no significant differences in performance in the IT task between the NM and FP conditions, suggesting no enhancement of visual processing occurred due to response preparation (Experiment 1). However, IT performance was significantly poorer in the PV condition in comparison to both the NM and FP conditions (Experiment 1), and was even worse when visual feedback was provided (Experiment 2). Together, these findings suggest that visual perceptual processing is degraded during execution of a fast, goal-directed movement.