A comparison of weighted countermovement jumps loading modes using wearable accelerometers

Background

The countermovement jump (CMJ) is an integral part of force and velocity profiling; a movement that is regularly implemented in training protocols and testing of athletic performance. Adding external loads to CMJs may have an added benefit for assessing gains in power and, in turn, monitoring progressive development. However, these added loads can displace the centre of mass of individuals, which may alter jump kinetics.

Objectives

The study aimed to evaluate kinetics across various incremental modes of loading (barbell, trapezius barbell, and dumbbell) CMJs.

Methods

Thirty-two male athletes (age: 19±2 years; height: 1.86±0.06 m, mass: 90.4±5.3 kg) completed three weighted CMJs (20, 40, 60 kg) across three bar-type modes of loading (barbell, trapezius barbell, and dumbbell). Jump metrics were measured using a wearable accelerometer. A repeated measures ANOVA was used to compare jump metrics (p<0.05).

Results

The results indicated changes in jump kinetics as added loads increased across all bar-type jump modes (p<0.001). Additionally, jump modes yielded different jump kinetics (p<0.001). Specifically, dumbbell CMJs produced the greatest force (2559 ± 462 N) and power (4861±1632 W) outputs. In contrast, the trapezius barbell consistently produced significantly (p<0.001) higher velocity (2.52±0.44 m.s-1) and acceleration (12.59±4.49 m.s-2), with the barbell never producing the highest kinetic metrics. The athletes' ranges of movement and comfort loading levels during the CMJs may be influential factors affecting vertical jump output metrics.

Conclusion

Overall, jump kinetics were altered by loads and jump types. Practically, different loading methods may target distinct jump variables allowing for individualised training programs specific for the athletes' needs.

Gender bias in assessing narcissistic personality: Exploring the utility of the ICD-11 dimensional model

OBJECTIVES

Narcissistic personality disorder as captured in categorical diagnostic systems (e.g., DSM-5) emphasizes grandiose features more associated with masculine norms and under-emphasizes vulnerable features more associated with femininity. This poses significant implications in diagnostic outcome and clinical treatment in women with narcissistic preoccupations. Research finds that clinicians using the DSM-5 categorical system tend to diagnose vulnerable narcissism in women as other 'feminized' personality disorders (e.g., borderline), but no research has explored gender differences in narcissism using the new ICD-11 dimensional framework for personality disorders. This study investigated the clinical utility of the ICD-11 approach in capturing gender differences in narcissistic presentations.

METHODS

Adopting an online vignette-based study, mental health clinicians (N = 157; 71.3% female) completed ratings of ICD-11 personality disorder severity and trait domains for two cases reflecting 'grandiose' and 'vulnerable' narcissism in hypothetical male or female patients.

RESULTS

The results showed that ratings of core impairments in personality functioning and overall severity were consistent irrespective of patient or clinician gender, contrasting prior research using categorical models.

CONCLUSION

While some differences were observed in trait domain (e.g., negative affectivity) between patient gender, these results suggest the clinical utility of the ICD-11 model as emphasizing elements of personality functioning in the process of assessment and diagnosis, therefore potentially being less susceptible to influences of gender stereotype in aiding clinical conceptualization.

ICNIRP Statement on Short Wavelength Light Exposure from Indoor Artificial Sources and Human Health

ABSTRACT

Concerns have been raised about the possibility of effects from exposure to short wavelength light (SWL), defined here as 380-550 nm, on human health. The spectral sensitivity of the human circadian timing system peaks at around 480 nm, much shorter than the peak sensitivity of daytime vision (i.e., 555 nm). Some experimental studies have demonstrated effects on the circadian timing system and on sleep from SWL exposure, especially when SWL exposure occurs in the evening or at night. The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has identified a lack of consensus among public health officials regarding whether SWL from artificial sources disrupts circadian rhythm, and if so, whether SWL-disrupted circadian rhythm is associated with adverse health outcomes. Systematic reviews of studies designed to examine the effects of SWL on sleep and human health have shown conflicting results. There are many variables that can affect the outcome of these experimental studies. One of the main problems in earlier studies was the use of photometric quantities as a surrogate for SWL exposure. Additionally, the measurement of ambient light may not be an accurate measure of the amount of light impinging on the intrinsically photosensitive retinal ganglion cells, which are now known to play a major role in the human circadian timing system. Furthermore, epidemiological studies of long-term effects of chronic SWL exposure per se on human health are lacking. ICNIRP recommends that an analysis of data gaps be performed to delineate the types of studies needed, the parameters that should be addressed, and the methodology that should be applied in future studies so that a decision about the need for exposure guidelines can be made. In the meantime, ICNIRP supports some recommendations for how the quality of future studies might be improved.

Are Different Modes of Weight Loss Associated with Survival in Oropharyngeal Cancer?

PURPOSE/OBJECTIVE(S)

Patients with oropharyngeal squamous cell carcinomas (OPSCC) often lose weight during radical radiotherapy (RT). Nutritional intervention is required in case of severe weight loss. However, weight loss does not provide full insight into body composition changes. Muscle mass is emerging as an important prognostic factor in cancer patients. We employed on-treatment cone-beam CT (CBCT) scans to monitor muscle mass and weight loss under the hypothesis that different modes of weight loss exist and may impact overall survival (OS).

MATERIALS/METHODS

A retrospective analysis of 197 OPSCC patients treated with definitive or adjuvant (chemo)RT. Weekly weight measurements & CBCTs were collected. Patients were included if at least two time-points were available and the interval between the first and last was between 15-50 days. CBCTs were normalized to account for calibration differences between treatment machines. An in-house deep-learning model automatically segmented the skeletal muscle compartment at C3 on all CBCTs. Segmentations were visually checked and failures removed. Skeletal muscle volume (SMV, in mm3) was extracted after thresholding for intra-muscular fat. Relative changes in weight & SMV were then calculated. Linear models were fitted to each trajectory for every patient and slopes were estimated. The following weight & SMV categories were defined to generate equal groups: lost (more than 0.4 standard deviations (SDs) below the mean (M)), maintained (within +/- 0.4 SDs of M) or gained (more than 0.4 SDs above the M). Table 1 highlights the nine modes of body composition change. The prognostic value of these was investigated in multivariable Cox models accounting for age, sex, disease stage, oropharynx subsite, smoking status, performance status (PS), tumor p16 status, baseline weight & SMV, and treatment prescribed. The primary endpoint was OS.

RESULTS

Mean weight & SMV changes during treatment were -0.047±0.001% & -0.044±0.019% per day. In multivariable analysis, gaining weight & losing SMV was identified as a significant risk factor for OS (p = 0.01, hazard ratio [95% CI]: 4.59 [1.40-15.10]). In this sub-group, mean weight & SMV change were +0.054±0.008% & -0.396±0.030% per day. PS>2 (p<0.001) & lower baseline weight (p = 0.02) were also significantly associated with OS.

CONCLUSION

Patients losing substantial SMV but mildly gaining weight have significantly worse OS than others. This suggests there exists a group of patients where nutritional support is needed, but not offered because they maintain weight during treatment. Although our results need validation, continual monitoring of muscle condition during RT would allow these patients to be identified and promptly targeted for nutritional support.

Registration of essential medicines in Kenya, Tanzania and Uganda: a retrospective analysis

OBJECTIVES

To audit national drug registers (NDRs) in Kenya, United Republic of Tanzania and Uganda with respect to national Essential Medicine Lists (EMLs) and to conduct an analysis of highly registered products including a sub-analysis of highly registered antimicrobial products.

DESIGN

Retrospective analysis of registration of essential medicines and medicinal products on NDRs as of February 2018.

SETTING

Not applicable.

PARTICIPANTS

None.

MAIN OUTCOME MEASURES

Registration status of essential medicines by country, essential medicine status of registered products by country and medicines with more than 50 registrations across all three countries.

RESULTS

A high proportion of essential medicines are not registered: Kenya 28% (175/632), United Republic of Tanzania 50% (400/797) and Uganda 40% (266/663). Of registered products on the NDRs, more than half are not essential: Kenya 71% (4350/6151), United Republic of Tanzania 64% (2278/3590) and Uganda 58% (2268/3896). When the three NDRs were combined, there were 42 medicines with over 50 registered products, accounting for 30% (4153/13637) of products, many of which were non-essential.

CONCLUSIONS

Non-registration of essential medicines is a barrier to availability. Over-registration of medicines, particularly non-essential medicines, diverts regulatory resources towards registering non-priority and, sometimes, clinically sub-optimal medicines. The East African Community Medicines Registration Harmonization Project has the potential to improve access to key medicines if registration of essential medicines is prioritised and registration of non-essential medicines is restricted.

The cycle ergometer test is not a reliable alternative to the countermovement jump in the assessment of power output

Background

Rugby union is a physically demanding collision sport that requires optimal neuromuscular function for maximal power output, with mechanical power an integral component of performance. Peak power (P_p) and relative P_p are parameters of neuromuscular function commonly assessed through the countermovement jump (CMJ) as a measure of fatigue. The Wattbike cycle ergometer test (CET) is a non-load bearing method of evaluating lower limb power. The cost-effective CET could therefore offer a viable alternative to the CMJ.

Objectives

This study aimed to determine the concurrent validity of the CMJ and CET.

Methods

Thirty-eight professional rugby union players performed twelve CMJs on a force platform with four loads (bodyweight: BW-CMJ; 20kg: 20-CMJ; 40kg: 40-CMJ and 60kg: 60-CMJ) and a six second peak power (6PPO) CET assessment on a Wattbike ergometer.

Results

CMJ power outputs were [BW-CMJ: P_p - 3101±648 W; 20-CMJ: P_p - 2724±513 W; 40-CMJ: P_p - 2490±496 W; 60-CMJ: P_p - 2238±366 W] and CET [P_p - 1310±161 W]. None of the CMJ-P_p values showed relationships with any CET power variables. Large (r = 0.51-0.63; p = 0.000 - 0.001) relationships were found to be between relative CMJ and relative CET power outputs. Bland-Altman plots, which were used to determine the level of agreement between the two assessments, showed the agreement between the tests was poor.

Conclusion

Though positive relationships existed between relative CMJ and relative CET power variables, analyses of the level of agreement in the Bland-Altman plots suggest that the two power assessment methods are not interchangeable measures of power.

Stabilized Radiation Pressure Acceleration and Neutron Generation in Ultrathin Deuterated Foils

Premature relativistic transparency of ultrathin, laser-irradiated targets is recognized as an obstacle to achieving a stable radiation pressure acceleration in the "light sail" (LS) mode. Experimental data, corroborated by 2D PIC simulations, show that a few-nm thick overcoat surface layer of high Z material significantly improves ion bunching at high energies during the acceleration. This is diagnosed by simultaneous ion and neutron spectroscopy following irradiation of deuterated plastic targets. In particular, copious and directional neutron production (significantly larger than for other in-target schemes) arises, under optimal parameters, as a signature of plasma layer integrity during the acceleration.

Efficacy of tPBM on ADHD symptoms and Executive Function Deficits in Adults with high-functioning Autism Spectrum Disorder

Introduction

Executive function (EF) deficits are often associated with Autism Spectrum Disorder (ASD), even in the absence of Attention Deficit Hyperactivity Disorder (ADHD) diagnosis. To date, no approved medication treatments exist for EF deficits associated with ASD.

Objectives

To assess the efficacy of transcranial photobiomodulation (tPBM) on EF in adults with ASD.

Methods

Adults (18-59) with high-functioning (HF)-ASD received twice a week tPBM for 8 weeks in an open-label single group design. ASD and EF deficits were assessed by clinician-rated Clinical Global Impression Scale and patient-rated scales of Behavior Rating Inventory of Executive Function-Adult (BRIEF-A).

Results

Eleven participants were enrolled. Ten participants completed the study. Nine participants who completed the study had comorbid ADHD diagnosis. All 10 participants were included in efficacy analyses of EF deficits. Statistically significant improvements in executive function deficits were found in BRIEF-A total score and in subdomains of Inhibition, Emotional Control, Planning and Organization, Organization of Materials, Behavioral Regulation, Metacognitive Index and Global Executive Control. All participants were found to have mild to moderate improvement in their ADHD symptom severity per clinician rated CGIs. Statistically significant improvements in ADHD symptoms were noted in self-rated scales. No adverse events required changes in tPBM protocol.

Conclusions

tPBM is a safe and feasible treatment approach that has the potential to treat core features of ASD. Further research is necessary and warranted.

Disclosure

This work is funded by Alan and Lorraine Bressler Clinical and Research Program for Autism Spectrum Disorder and the MGH Pediatric Psychopharmacology Council Fund.

Absolute calibration of Fujifilm BAS-TR image plate response to laser driven protons up to 40 MeV

Image plates (IPs) are a popular detector in the field of laser driven ion acceleration, owing to their high dynamic range and reusability. An absolute calibration of these detectors to laser-driven protons in the routinely produced tens of MeV energy range is, therefore, essential. In this paper, the response of Fujifilm BAS-TR IPs to 1-40 MeV protons is calibrated by employing the detectors in high resolution Thomson parabola spectrometers in conjunction with a CR-39 nuclear track detector to determine absolute proton numbers. While CR-39 was placed in front of the image plate for lower energy protons, it was placed behind the image plate for energies above 10 MeV using suitable metal filters sandwiched between the image plate and CR-39 to select specific energies. The measured response agrees well with previously reported calibrations as well as standard models of IP response, providing, for the first time, an absolute calibration over a large range of proton energies of relevance to current experiments.

Pathways from Diagnosis to Death from Keratinocyte Cancer in Kidney Transplant Recipients

BACKGROUND

Kidney transplant recipients are at increased risk of developing and dying from keratinocyte cancer. We aimed to describe the clinical course of keratinocyte cancer-related deaths in a cohort of kidney transplant recipients.

METHODS

In kidney transplant recipients transplanted between 1995 and 2014 in Queensland, Australia, we ascertained keratinocyte cancer deaths by searching national transplant and state death registries to March 2020. Deceased transplant recipients' medical records were reviewed to assess features of the primary lesion of the fatal keratinocyte cancer, metastases, and clinical information before death.

RESULTS

Of 658 kidney transplant recipient deaths, 49 (7%) were due to keratinocyte cancer, and medical records were available for 36 (73%). One death was due to basal cell carcinoma, and 35 were from squamous cell carcinoma (SCC), primarily from the head and neck (24; 69%). The most common site of metastasis was the lungs (21; 58%). Median time (minimum, maximum) from the diagnosis of primary SCC to metastasis was 5 months (0, 29). After this, the median time to death was 9 months (1, 50).

CONCLUSION

Fatal keratinocyte cancers overwhelmingly arise on the head and neck, with lungs the most common metastasis site. The short time from diagnosis of primary to death indicates the aggressive nature of these keratinocyte cancers.