Sensitivity of Countermovement Jump Variables in Professional Rugby Union Players Within a Playing Season.

ABSTRACT: Howarth, DJ, McLean, BD, Cohen, DD, and Coutts, AJ. Sensitivity of countermovement jump variables in professional rugby union players within a playing season. J Strength Cond Res 37(7): 1463-1469, 2023-The aim of this study was to explore the measurement sensitivity of a wide range of countermovement jump (CMJ) variables to a full European professional rugby union season. A secondary purpose was to compare 3 different data treatment methods for the calculation of CMJ variables. Twenty-nine professional rugby union players (mean ± SD; age 24 ± 4 years, height 183.7 ± 8.0 cm, body mass 101.6 ± 10.7 kg) completed a minimum of 12 CMJ testing sessions on Thursdays-a day preceded by a rest day and a minimum of 96 hours after a match-throughout a season. Measurement sensitivity, quantified by signal-to-noise ratio (SNR), was determined for 74 CMJ variables and was calculated by dividing the signal, (week-to-week variation expressed as a coefficient of variation [CV%]) by the noise (interday test/retest reliability expressed as CV%). We also identified variables which had no overlap between the 95% confidence intervals (CIs) for the signal and the noise. The 3 data treatment methods for comparison were (a) mean output across 3 jump trials (Mean3), (b) single output from the trial with the highest jump (BestJH), and (c) the trial with the highest flight time to contraction time ratio (BestFTCT). Most variables had an SNR >1.0 (Mean3 = 60/74; BestFTCT = 59/74; BestJH = 48/74). Fewer variables displayed a nonoverlap of 95% CIs (Mean3 = 23/60; BestFTCT = 22/59; BestJH = 16/48). Most CMJ variables during a professional rugby season demonstrated a signal that exceeded measured noise (SNR > 1.0) and that using the Mean3 or BestFTCT data treatment methods yields a greater number of variables considered sensitive within a season (i.e., SNR > 1.0) than when using BestJH. We also recommend the calculation of the 95% CIs for both signal and noise, with nonoverlap indicative of a greater probability that the responsiveness of the variable at team level (i.e., SNR) also applies at the individual level. As sensitivity analysis is cohort and environment specific, practitioners should conduct a sensitivity analysis using internal signal and noise data to inform their own monitoring protocols.

English tort law and the pandemic: the dog that has not barked.

As of February 2023, no case has been reported in the U.K., either in the law reports or in the media, of a victim of COVID-19 suing in tort a person or organisation alleged to have caused the victim to contract the disease. This article considers the reasons this situation might have arisen. It provisionally concludes that the main legal reasons might lie in the applicable doctrines of factual causation and goes on to discuss whether uncertainty in those doctrines should be resolved in the courts.

Using intrinsic properties of quantum dots to provide additional security when uniquely identifying devices.

Unique identification of optical devices is important for anti-counterfeiting. Physical unclonable functions (PUFs), which use random physical characteristics for authentication, are advantageous over existing optical solutions, such as holograms, due to the inherent asymmetry in their fabrication and reproduction complexity. However, whilst unique, PUFs are potentially vulnerable to replication and simulation. Here we introduce an additional benefit of a small modification to an established model of nanoparticle PUFs by using a second measurement parameter to verify their authenticity. A randomly deposited array of quantum dots is encapsulated in a transparent polymer, forming a tag. Photoluminescence is measured as a function of excitation power to assess uniqueness as well as the intrinsic nonlinear response of the quantum material. This captures a fingerprint, which is non-trivial to clone or simulate. To demonstrate this concept practically, we show that these tags can be read using an unmodified smartphone, with its built-in flash for excitation. This development over constellation-style optical PUFs paves the way for more secure, facile authentication of devices without requiring complex fabrication or characterisation techniques.

Establishing the Noise: Interday Ecological Reliability of Countermovement Jump Variables in Professional Rugby Union Players.

ABSTRACT: Howarth, DJ, Cohen, DD, McLean, BD, and Coutts, AJ. Establishing the noise: interday ecological reliability of countermovement jump variables in professional rugby union players. J Strength Cond Res 36(11): 3159-3166, 2022-The purpose of this study was to examine the interday "ecological" reliability of a wide range of ground reaction force-derived countermovement jump (CMJ) variables. Thirty-six male, professional rugby union players performed 3 CMJs on 4 separate days over an 8-day period during the first week of preseason. We calculated reliability for 86 CMJ variables across 5 interday combinations using 2 criteria: mean output across 3 jump trials (Mean 3 ) and single output from the highest jump (Best JH ). Interday coefficient of variation (CV) of the 86 variables in each CMJ phase, for Mean 3 and Best JH , respectively, ranged between concentric = 2-11% and 2-13%; eccentric = 1-45% and 1-107%; and landing = 4-32% and 6-45%. Mean 3 interday CV was lower in all 86 variables across every interday combination, compared with Best JH . CVs were lower in our cohort than previous studies, particularly for eccentric phase variables. There was no meaningful difference between interday conditions, suggesting any 2-day combination conducted within the first 8 days of preseason, represents a measure of "noise." We did not apply arbitrary reliability "cut-offs" used in previous work (e.g., CV <10%); therefore, our analysis provides reference reliability for a wide range of CMJ variables. However, we recommend that practitioners assess reliability in their athletes, as it is likely to be environment, protocol, and cohort specific.

Clinicopathological Correlates: Chronic Arsenic Toxicity Causing Bilateral Symmetric Progressive Optic Neuropathy.

A 70 year-old man presented with insidiously progressing central visual acuity loss in both eyes over several years. Objectively the only abnormality identified on the exam was questionable granularity in the fovea in each eye. Extensive work up which included neuro-imaging, screening blood work for toxic and nutritional causes of optic neuropathy as well as electroretinogram and fluorescein angiography to rule out subtle maculopathy was all unrevealing. When vision continued to deteriorate over the next several years investigations were repeated and again did not yield any positive results. Levels of heavy metals were then obtained after further progression of visual loss, revealing very high levels of arsenic. Subsequent investigations revealed that patient has been spending almost every weekend for the past 28 years alone at a remote country cottage where the sole supply of water was from the local well. He also recalled that 1.5 months after purchasing the cottage he developed hemorrhagic colitis requiring partial colectomy. The specimen from colectomy was located and total reflection x-ray fluorescence testing performed in a specialized lab revealed greatly increased level of arsenic particle in the colonic biopsy from 28 years ago. This case is a reminder that heavy metal toxicity should be considered in a differential diagnosis of patients with bilateral symmetric optic neuropathy.

Ex vivo quantification of lanthanum and gadolinium in post-mortem human tibiae with estimated barium and iodine concentrations using K x-ray fluorescence.

OBJECTIVES: Lanthanum (La) and gadolinium (Gd) are known to deposit in bone of exposed populations, namely those who are orally administered lanthanum carbonate (LaC, La2(CO3)3) or are injected with Gd-based contrast agents, respectively. In this work, bone La and Gd concentrations from the environment and diet were measured using x-ray fluorescence in ten post-mortem human tibiae. As a secondary objective, bone barium (Ba) and iodine concentrations were estimated. APPROACH: Two calibration lines were produced for La and Gd and the minimum detection limits (MDLs) of the system were determined using a 180° irradiation-detection geometry. MAIN RESULTS: The MDLs of the system were 0.4 µg La g-1 bone mineral and 0.5 µg Gd g-1 bone mineral. The mean concentrations were -0.02 ± 0.1 µg La g-1 bone mineral and 0.1 ± 0.2 µg Gd g-1 bone mineral in tibiae. The average Ba and iodine concentrations estimated from the experimental La calibration line and Monte-Carlo derived sensitivity factors were determined to be 3.4 ± 0.8 µg Ba g-1 bone mineral and -0.5 ± 0.3 µg iodine g-1 bone mineral. Since it was discovered that four donors previously received an iodine-based contrast agent, the mean concentrations in these donors was 27.8 ± 28.4 µg iodine g-1 bone mineral. SIGNIFICANCE: The XRF system has determined baseline concentrations of these four heavy metals in trace quantities from natural exposure pathways (with the exception of iodine in four donors). This indicates that the system can measure low levels in ex vivo tibiae samples and can potentially be further developed for in vivo studies involving live subjects who are directly exposed to these metals.

What do the British public think of inequality in health, wealth, and power?

Despite the importance of public opinion for policy formation and the political salience of inequality, the public's views about the desirability of equality, not only in health but also in economics and politics, has attracted little attention. We report the results of an on-line survey administered in late 2016 in Great Britain (N = 1667 with a response rate of 35-50%). The survey allowed for testing the sensitivity of public opinion across two other variables: absolute versus relative (everyone should have the same versus inequality should be reduced) and bivariate versus univariate (inequality in one domain is judged in relation to inequality in another versus inequality in a domain is judged independently of other domains). It also allowed examination of how far support for equality in one domain overlaps with support for equality in another. We find that for health, economic and political equality a relative conception of equality attracts more support than an absolute conception, and that for health and political equality a bivariate conception attracts more support than a univariate conception. We also find that conceptions of equality affect how much overlap exists between support for different forms of equality, with a bivariate and relative conception resulting in more overlap than a univariate and absolute conception. We also find evidence for Walzer's 'complex equality' theory in which people tolerate inequality in one domain if it does not control inequality in another.

Dermatofibrosarcoma protuberans with a novel COL6A3-PDGFD fusion gene and apparent predilection for breast.

Dermatofibrosarcoma protuberans is a locally aggressive superficial mesenchymal neoplasm. It typically occurs in adulthood, and has been reported to have a slight male predilection. Tumors have a characteristic histopathologic appearance, including: storiform architecture, infiltrative "honeycomb" growth within subcutaneous adipose tissue, and immunoreactivity for CD34. Virtually all molecularly characterized cases to date have been found to harbor a COL1A1-PDGFB fusion product. Following identification of an index patient with a novel COL6A3-PDGFD fusion gene, we undertook a molecular investigation, using a combination of RNA sequencing and fluorescence in situ hybridization (FISH), to assess the prevalence of PDGFD rearrangement in dermatofibrosarcoma protuberans (N = 63). Three additional patients were found to have balanced PDGFD rearrangements. Interestingly, all 4 tumors arose on the breast of females. As a result, we subsequently examined 16 additional cases of primary breast dermatofibrosarcoma protuberans, identifying 2 additional tumors with PDGFD rearrangement. The morphology and immunophenotype of all 6 cases was analogous to those with the canonical COL1A1-PDGFB fusion; none of the cases showed fibrosarcomatous transformation. This study illustrates that the COL6A3-PDGFD fusion product is rare in dermatofibrosarcoma protuberans, and associated with an apparent predilection for breast. An awareness of this variant is important for pathologists, as it will not be detected using conventional reverse transcription polymerase chain reaction or FISH-based diagnostic assays for dermatofibrosarcoma protuberans.

Late unilateral hematoma after breast augmentation.

BACKGROUND: Late hematoma after breast augmentation is a rare phenomenon with unproven etiology. METHODS: Five patients presented with a late unilateral hematoma after receiving bilateral, submuscular, smooth, round, silicone gel implants for cosmetic breast augmentation. All patients underwent explantation and capsulectomy. Extensive clinical and histological analysis of all capsules was performed. RESULTS: All patients presented with progressive unilateral breast enlargement with at least a doubling of their breast size. Breast enlargement developed nine, 12, 14, 22 and 38 years, respectively, after initial implant insertion and in the absence of any known trauma. Patients presented for treatment one, three, four, nine and 12 months, respectively, after initially noticing breast enlargement. This enabled a sequential analysis of the events occurring on the surface of the capsule and within the structure of the capsule. Macroscopic and microscopic analysis of all capsules demonstrated multiple areas of recent and older hemorrhage, both within the structure of capsules and on the surface of the capsule. Continuing recurrent bouts of acute hemorrhage were observed even nine and 12 months after initial hematoma development. The position of medium-size vessels within the capsules corresponded to the sites of recurrent bleeding within capsules. CONCLUSIONS: Late hematomas presented from nine to 38 years after submuscular breast augmentation with a doubling of breast size. Late hematomas appeared to result from multiple recurrent bouts of bleeding within the structure of the capsules. This leads to recurrent bleeding on the surface of the capsules. Breast enlargement develops progressively over time rather than acutely. Continuing acute hemorrhage persisted up to one year after initial hematoma development. This progression suggests a process analogous to a chronic expanding hematoma that has been described in other areas of the body. Failure to remove a capsule could result in long-term continuing bleeding from vessels within the capsule.

HISTORIQUE: L'apparition d'un hématome tardif après une augmentation mammaire est un phénomène rare dont l'étiologie n'est pas démontrée. MÉTHODOLOGIE: Cinq patientes ont consulté à cause d'un hématome unilatéral tardif consécutif à l'installation d'implants mammaires bilatéraux en gel de silicone à surface lisse et de forme ronde en position rétromusculaire en vue d'une augmentation mammaire esthétique. Toutes les patientes ont subi une explantation et une capsulectomie. Les chercheurs ont effectué une analyse clinique et histologique approfondie de toutes les capsules. RÉSULTATS: Toutes les patients présentaient une hypertrophie mammaire unilatérale progressive ayant au moins doublé la taille de leur sein. Cette hypertrophie s'est manifesté neuf, 12, 14, 22 et 38 ans, respectivement, après l'insertion initiale des implants, en l'absence de tout traumatisme connu. Les patientes ont consulté pour être traitées un, trois, quatre, neuf, et 12 mois, respectivement, après avoir remarqué l'hypertrophie. Il a donc été possible de procéder à une analyse séquentielle des événéments se produisant à la surface et dans la structure de la capsule. L'analyse macroscopique et microscopique de toutes les capsules a démontré de nombreuses zones d'hémorragies récentes et anciennes, à la fois dans la structure et à la surface des capsules. Des accès récurrents d'hémorragie aiguë ont même continué de se produire neuf et 12 mois après l'apparition de l'hématome. La position de vaisseaux de taille moyenne dans les capsules correspondait aux foyers de saignements récurrents s'y produisant. CONCLUSIONS: Les hématomes tardifs se sont manifestés de neuf à 38 ans après une augmentation mammaire en position rétromusculaire et ont doublé la taille du sein. Ils semblaient découler de multiples accès récurrents de saignements dans la structure des capsules. L'hypertrophie mammaire s'est produite progressivement plutôt que de manière subite. Les hémorragies aiguës ont persisté jusqu'à un an après l'apparition initiale de l'hématome. Cette progression laisse supposer un processus analogue à l'expansion chronique des hématomes décrite dans d'autres parties du corps. Si on n'extrait pas la capsule, les saignements risquent de s'y poursuivre à long terme.

Sampling modality influences the predictive value of grading in adult soft tissue extremity sarcomas.

CONTEXT: Histologic grade is one of the best predictors of outcome in adult soft tissue sarcomas. Current grading systems were validated on resection specimens; however, there has been a trend toward the use of biopsies to diagnosis these tumors. OBJECTIVES: To determine whether the grade of an extremity soft tissue sarcoma determined on tissue obtained by either core needle biopsy or incisional biopsy is predictive of metastasis- or disease-free survival, and whether either sampling modality is superior. DESIGN: One hundred three core needle biopsies and 107 incisional biopsies of nonmetastatic spindle cell sarcomas of the extremities were retrieved from the archives. All cases had a minimum 2-year follow-up. Patient data and outcome and tumor characteristics were recorded. Tumors were reviewed and evaluated using the French Federation of Cancer Centers Sarcoma Group grading system. Kaplan-Meier survival curves were generated to correlate tumor grade with metastasis- and disease-free survival for both groups. RESULTS: Patient and tumor characteristics were similar between groups except that more tumors were grade 3 and superficial in the incisional biopsy group. Grade determined on core needle biopsy was not predictive of either metastasis-free survival (P = .59) or disease-free survival (P = .50). In contrast, grade determined on incisional biopsy was predictive of both metastasis-free survival (P < .001) and disease-free survival (P = .001). CONCLUSIONS: Biopsy, particularly core needle biopsy, represents a convenient diagnostic tool, particularly in the context of neoadjuvant therapy. However, based on these results incisional biopsy is recommended if grading is to be used to predict prognosis in spindle cell soft tissue sarcomas of the extremities.

Synovial sarcoma of the brachial plexus: case report.

BACKGROUND AND IMPORTANCE: Synovial sarcoma (SS) is a malignant soft-tissue tumor that rarely involves brachial plexus. The authors report a case of brachial plexus SS and review the relevant literature. CLINICAL PRESENTATION: A 53-year-old woman presented with gradually enlarging right subclavicular mass over 5 years associated with sharp aching pain radiating down toward the radial 3 fingers. On examination, she had a corresponding firm mass in the supraclavicular region with a positive Tinel sign. There was no objective neurological deficit. She underwent partial excision of this mass without any further adjuvant radiation or chemotherapy. Pathology was consistent with SS. CONCLUSION: Lack of any recurrence in this case 6 years after incomplete excision with no adjuvant therapy suggests slow clinical course in some of these sarcomas.

p63 expression in adamantinoma.

Adamantinoma is a rare primary bone neoplasm with epithelial differentiation that is frequently associated with a concomitant fibrous component. Clinical, cytogenetic and histomorphologic overlap has previously been described with osteofibrous dysplasia, thereby suggesting a relationship between these two lesions. We performed a retrospective review of our archives to characterize the clinical and pathologic aspects of adamantinoma and osteofibrous dysplasia diagnosed at our institution, and to compare the expression patterns of p63 and keratin. Nine cases of adamantinoma (six classical, three osteofibrous dysplasia-like) and 11 cases of osteofibrous dysplasia were identified. The epithelial component in adamantinoma was found to stain for p63. Rare cells expressing p63 were also identified in eight cases of osteofibrous dysplasia. Expression of p63 was not identified in any of the five cases of fibrous dysplasia controls. The presence of staining for p63, albeit rare, in osteofibrous dysplasia supports the notion of a possible relationship between osteofibrous dysplasia and adamantinoma. Furthermore, our results suggest that, in some situations, p63 may be useful in helping differentiate metastatic carcinoma from adamantinoma.

Sterile single use cover for the G-probe Transscleral Cyclodiode.

PURPOSE: Multiuse of the G-probe transscleral cyclophotocoagulation (TSCPC) device can lead to contamination. We evaluated the mechanical stability and clinical efficacy of a disposable sterile barrier for the G-probe footplate. METHODS: We measured diode laser output with and without the G-probe barrier both before and after cadaver TSCPC (18 shots at 2000 mW for 2000mS). Qualitative analyses of the laser aiming beam were made before each trial in the barrier and nonbarrier state. After each trial, the G-probe barrier was examined for microperforations and footplate for debris and/or damage. Microbiology was taken on the cadaver eye and the G-probe before and after 20 cycles. Histologic analysis after TSCPC with and without barrier was carried out on a cadaver eye. RESULTS: Qualitatively, laser focus dispersion was minimized by the G-probe cover. Mean (95% CI) laser output was measured for the nonbarrier, with barrier pre-TSCPC and with barrier post-TSCPC, respectively as 980 mW (899,1061), 1247 mW (1115, 1378), and 1240 mW (1132, 1347). The difference between the nonbarrier and barrier both preTSCPC and postTSCPC was statistically significant (df=2, F=36.26, P<0.01). No perforations in the G-probe barrier were evident and no debris or damage was detected on the G-probe. Pathology was consistent with earlier reports of TSCPC in cadaver eyes. Microbial segregation of the cadaver eye and the G-probe footplate was maintained. CONCLUSIONS: The G-probe barrier is an effective and robust method to protect consecutive patients from contamination during TSCPC. Although energy levels were slightly higher in probes with barrier, histologic differences were not evident and the clinical significance of this finding is likely limited.

A radio-sensitive primary osteosarcoma in the lung.

We report an unusual case of a primary osteosarcoma of the lung in an asymptomatic 77-year-old male, who underwent lobectomy with complete resection of the lung lesion. His pattern of relapse was to multiple lymph nodes. The first relapse was 11 weeks after lobectomy in subcarinal lymph nodes, confirmed on needle aspiration to be consistent with sarcoma. Given his excellent performance status, this was treated with radical radiotherapy to 70 Gy in 35 fractions with good control. He relapsed to other lymph node regions. A biopsy of the external iliac lymph node was done and revealed osteoid production, consistent with osteosarcoma. He received palliative radiotherapy to several nodal areas with good clinical response. We review the literature of this rare tumor with an unusual pattern of relapse.

Barriers to weight loss in obese patients with knee osteoarthritis.

INTRODUCTION: Obesity contributes to the development of knee osteoarthritis and complicates its surgical treatment. The aim of this study was to explore barriers to effective weight management in obese patients with knee osteoarthritis. PATIENTS AND METHODS: A cross-sectional questionnaire study was performed in an elective out-patient setting and on an orthopaedic ward on patients with a body mass index (BMI) of 30 kg/m2 or over and knee osteoarthritis. RESULTS: Of 47 patients approached, 45 agreed to participate. Forty of 45 patients (89%) had tried to lose weight at some point, 35 of 40 (87.5%) by adjusting their diet. Forty of 45 (89%) patients considered lack of motivation to be the greatest barrier to weight loss and only 13 of 45 (28%) pain in the knee. Patients with a BMI of less than 40 kg/m2 expressed a preference for dietary advice to help with weight loss, compared with those with a BMI of over 40 kg/m2 who expressed a preference for an NHS or other support group. CONCLUSIONS: Obesity is a significant problem for many patients with knee osteoarthritis. Attendance at an orthopaedic clinic is an opportunity to address obesity, by providing information about diet and possibly support groups for morbidly obese patients. Patients may be motivated to lose weight to improve their symptoms.

Magnetic resonance in systems with equivalent spin-1/2 nuclides. Part 3: Ket analysis and spectral intensities.

In earlier papers (Parts 1 and 2), featuring group-theoretical analysis, it was shown that the isotropic EPR spectra of free radical (S=1/2) species XL(n), where the n equivalent nuclei also have spin 1/2, have a more complicated form than disclosed by the usual (first-order) oversimplified analysis. Explicit solutions for n=3 (analytic, as well as computational) of the spin-hamiltonian matrix H(s) for the energies and spin states were obtained and given in Part 2, but are amplified herein, and differences in several important representations of H(s) are discussed. In the present work, we focus also on details of relative spectral intensities, some of which are not straightforward. Subtle asymmetry effects in relevant EPR spectra are demonstrated. The crucial factor here turns out to reside in the difference between field-swept and frequency-swept spectra, and hinges on the fact that H(s) for the two states involved in any transition depends on Zeeman-field B as a variable in field-swept spectra, but B is a constant in frequency-swept spectra. An experimental spectrum of the free radical CF(3) is used as a quantitative example.