Musculoskeletal modelling of the human cervical spine for the investigation of injury mechanisms during axial impacts

This is the final version. Available from Public Library of Science via the DOI in this record.All relevant data are available at Figshare [https://figshare.com/projects/SILVESTROS_PLOS_ONE_SUPPORTING_DOCUMENTS/58280] and musculoskeletal models and relevant project information is available on the OpenSim SimTK repository [https://simtk.org/projects/csibath].Head collisions in sport can result in catastrophic injuries to the cervical spine. Musculoskeletal modelling can help analyse the relationship between motion, external forces and internal loads that lead to injury. However, impact specific musculoskeletal models are lacking as current viscoelastic values used to describe cervical spine joint dynamics have been obtained from unrepresentative quasi-static or static experiments. The aim of this study was to develop and validate a cervical spine musculoskeletal model for use in axial impacts. Cervical spine specimens (C2-C6) were tested under measured sub-catastrophic loads and the resulting 3D motion of the vertebrae was measured. Specimen specific musculoskeletal models were then created and used to estimate the axial and shear viscoelastic (stiffness and damping) properties of the joints through an optimisation algorithm that minimised tracking errors between measured and simulated kinematics. A five-fold cross validation and a Monte Carlo sensitivity analysis were conducted to assess the performance of the newly estimated parameters. The impact-specific parameters were integrated in a population specific musculoskeletal model and used to assess cervical spine loads measured from Rugby union impacts compared to available models. Results of the optimisation showed a larger increase of axial joint stiffness compared to axial damping and shear viscoelastic parameters for all models. The sensitivity analysis revealed that lower values of axial stiffness and shear damping reduced the models performance considerably compared to other degrees of freedom. The impact-specific parameters integrated in the population specific model estimated more appropriate joint displacements for axial head impacts compared to available models and are therefore more suited for injury mechanism analysis.Rugby Football Union (RFU) Injured Players Foundatio

Intraoperative Evaluation of Nasal Valve Repair Interventions: A Prospective Analysis

Objectives: To allow for early identification and treatment of inadequate nasal valve repair interventions in the intraoperative setting, based on degree of nasal valve collapse quantified by suction-assisted pressure readings. Patient outcomes were measured by comparison of pre- and post-operative Nasal Obstruction Symptom Evaluation (NOSE) surveys. Study Design: Prospective study. Methods: All enrolled patients undergo suction-assisted evaluation of nasal valve collapse before surgical intervention. Patients randomized into the experimental group underwent repeat assessment after various nasal valve interventions, compared to a control group where adequacy of interventions was assessed by palpation of the nasal ala. Results: 20 patients who underwent nasal valve repair were first randomized into control (10) or experimental (10) groups. Two patients in the control group did not receive nasal valve work due to pre-operative readings and were excluded from further analysis. Nasal valve interventions included alar rim grafts (5), spreader grafts (10), batten grafts (2), and nasal valve suture suspension (8). After nasal valve interventions, average suction reading at first sign of collapse increased by 92% (p \u3c 0.0001) and average suction reading at maximal collapse increased by 16% (p \u3c 0.0001). Pre-operative NOSE scores decreased by 55% (p \u3c 0.0001) at the first follow-up visit at 9.3±3.5 days. No patients in the experimental group required additional nasal valve interventions after repeat suction-assisted evaluations intraoperatively. Conclusion: Intraoperative suction-assisted evaluation of nasal valve collapse can help assess adequacy of nasal valve interventions and determine whether additional interventions are necessary to improve nasal valve integrity.https://jdc.jefferson.edu/otoposters/1011/thumbnail.jp

Fat Graft for Parotidectomy Defect Reconstruction in the Setting of Malignant Disease

Objectives: Currently, limited data examines the safety of utilizing fat transfers in the setting of malignant parotid disease. Here we evaluate the safety of fat graft reconstruction of parotidectomy defects in the setting of malignant disease. Study Design: Retrospective cohort study Methods: Electronic chart review of patients who underwent parotidectomy from 2012-2020 were reviewed. Results: Three hundred and sixty-one patients were identified at a single institution who underwent parotidectomy, and 113 (31.3%) were for malignancy. One hundred and thirty-two patients underwent fat graft reconstruction (49.2%, n=65 for umbilical, 50.8%, n=67 for dermal). One-third of patients had malignant pathology (34.8%, n=46). The most common malignant tumors were squamous cell carcinoma (n=15), acinic cell carcinoma (n=9), and mucoepidermoid carcinoma (n=6). Twenty patients (45.5%) received postoperative radiation therapy. Complications included: surgical site necrosis (13%), hematoma (4.3%), and infection (2.2%). Overall incidence of malignant recurrence was 4.4% with a mean time of follow-up of 10.3 (range 0 – 77.3) months. Incidence of malignant recurrence in the fat graft reconstruction subset was 0% with a mean follow-up of 9.8 (range 0.2 – 49.3) months. There was no association with use of fat graft and recurrence (p\u3e0.05). Conclusion: Parotidectomy defects for malignant neoplasms can be reconstructed with fat graft transfers with no impact on surveillance for disease recurrence.https://jdc.jefferson.edu/otoposters/1010/thumbnail.jp

Paleophysical Oceanography with an Emphasis on Transport Rates

Paleophysical oceanography is the study of the behavior of the fluid ocean of the past, with a specific emphasis on its climate implications, leading to a focus on the general circulation. Even if the circulation is not of primary concern, heavy reliance on deep-sea cores for past climate information means that knowledge of the oceanic state when the sediments were laid down is a necessity. Like the modern problem, paleoceanography depends heavily on observations, and central difficulties lie with the very limited data types and coverage that are, and perhaps ever will be, available. An approximate separation can be made into static descriptors of the circulation (e.g., its water-mass properties and volumes) and the more difficult problem of determining transport rates of mass and other properties. Determination of the circulation of the Last Glacial Maximum is used to outline some of the main challenges to progress. Apart from sampling issues, major difficulties lie with physical interpretation of the proxies, transferring core depths to an accurate timescale (the “age-model problem”), and understanding the accuracy of time-stepping oceanic or coupled-climate models when run unconstrained by observations. Despite the existence of many plausible explanatory scenarios, few features of the paleocirculation in any period are yet known with certainty.National Science Foundation (U.S.) (grant OCE-0645936

The HERMIT in the Tree

This paper describes our experience using the HERMIT tool- kit to apply well-known transformations to the internal core language of the Glasgow Haskell Compiler. HERMIT provides several mechanisms to support writing general-purpose transformations: a domain-specific language for strategic programming specialized to GHC's core language, a library of primitive rewrites, and a shell-style{based scripting language for interactive and batch usage. There are many program transformation techniques that have been described in the literature but have not been mechanized and made available inside GHC - either because they are too specialized to include in a general-purpose compiler, or because the developers' interest is in theory rather than implementation. The mechanization process can often reveal pragmatic obstacles that are glossed over in pen-and-paper proofs; understanding and removing these obstacles is our concern. Using HERMIT, we implement eleven examples of three program transformations, report on our experience, and describe improvements made in the process

The future burden of lung cancer attributable to current modifiable behaviours: a pooled study of seven Australian cohorts

BACKGROUND: Knowledge of preventable disease and differences in disease burden can inform public health action to improve health and health equity. We quantified the future lung cancer burden preventable by behavioural modifications across Australia. METHODS: We pooled seven Australian cohort studies (n = 367 058) and linked them to national registries to identify lung cancers and deaths. We estimated population attributable fractions and their 95% confidence intervals (CIs) for modifiable risk factors, using risk estimates from the cohort data and risk factor exposure distribution from contemporary national health surveys. RESULTS: During the first 10-year follow-up, there were 2025 incident lung cancers and 20 349 deaths. Stopping current smoking could prevent 53.7% (95% CI, 50.0-57.2%) of lung cancers over 40 years and 18.3% (11.0-25.1%) in 10 years. The smoking-attributable burden is highest in males, those who smoke <20 cigarettes per day, are <75 years of age, unmarried, of lower educational attainment, live in remote areas or are healthy weight. Increasing physical activity and fruit consumption, if causal, could prevent 15.6% (6.9-23.4%) and 7.5% (1.3-13.3%) of the lung cancer burden, respectively. Jointly, the three behaviour modifications could prevent up to 63.0% (58.0-67.5%) of lung cancers in 40 years, and 31.2% (20.9-40.1%) or 43 300 cancers in 10 years. The preventable burden is highest among those with multiple risk factors. CONCLUSIONS: Smoking remains responsible for the highest burden of lung cancer in Australia. The uneven burden distribution distinguishes subgroups that could benefit the most from activities to control the world's deadliest cancer

How people with dementia and their families decide about moving to a care home and support their needs: development of a decision aid, a qualitative study

yesBackground: People with dementia and their relatives find decisions about the person with dementia living in a care home difficult. Methods: We interviewed 20 people with dementia or family carers around the time of this decision in order to design a decision-aid. Results: Decision-makers balanced the competing priorities of remaining somewhere familiar, family’s wish they remain at home, reduction of risk and effects on carer’s and person with dementia’s physical health. The person with dementia frequently resented their lack of autonomy as decisions about care home moves were made after insight and judgment were impaired. Family consultation usually helped carers but sometimes exacerbated tensions. Direct professional support was appreciated where it was available. There is a need for healthcare professionals to facilitate these conversations around decision-making and to include more than signposting to other organisations. Conclusions: There is a need for a healthcare professional facilitated decision-aid. This should detail what might change for the person with dementia and their carer, possible resources and alternatives and assist in facilitating discussion with the wider family; further research will develop and test a tool to facilitate decision making about place of care needs

Neonicotinoid pesticide limits improvement in buzz pollination by bumblebees

Neonicotinoid pesticides have been linked to global declines of beneficial insects such as bumblebees. Exposure to trace levels of these chemicals causes sub-lethal effects, such as reduced learning and foraging efficiency. Complex behaviours may be particularly vulnerable to the neurotoxic effects of neonicotinoids. Such behaviours may include buzz pollination (sonication), in which pollinators, usually bees, use innate and learned behaviours to generate high-frequency vibrations to release pollen from flowers with specialised anther morphologies. This study assesses the effect of field-realistic, chronic exposure to the widely-used neonicotinoid thiamethoxam on the development of sonication buzz characteristics over time, as well as the collection of pollen from buzz-pollinated flowers. We found that the pollen collection of exposed bees improved less with increasing experience than that of unexposed bees, with exposed bees collecting between 47% and 56% less pollen by the end of 10 trials. We also found evidence of two distinct strategies for maximising pollen collection: (1) extensions to the duration of individual buzzes and (2) extensions of the overall time spent buzzing. We find new complexities in buzz pollination, and conclude that the impacts of field-realistic exposure to a neonicotinoid pesticide may seriously compromise this important ecosystem service

Polycation-π Interactions Are a Driving Force for Molecular Recognition by an Intrinsically Disordered Oncoprotein Family

Molecular recognition by intrinsically disordered proteins (IDPs) commonly involves specific localized contacts and target-induced disorder to order transitions. However, some IDPs remain disordered in the bound state, a phenomenon coined "fuzziness", often characterized by IDP polyvalency, sequence-insensitivity and a dynamic ensemble of disordered bound-state conformations. Besides the above general features, specific biophysical models for fuzzy interactions are mostly lacking. The transcriptional activation domain of the Ewing's Sarcoma oncoprotein family (EAD) is an IDP that exhibits many features of fuzziness, with multiple EAD aromatic side chains driving molecular recognition. Considering the prevalent role of cation-π interactions at various protein-protein interfaces, we hypothesized that EAD-target binding involves polycation- π contacts between a disordered EAD and basic residues on the target. Herein we evaluated the polycation-π hypothesis via functional and theoretical interrogation of EAD variants. The experimental effects of a range of EAD sequence variations, including aromatic number, aromatic density and charge perturbations, all support the cation-π model. Moreover, the activity trends observed are well captured by a coarse-grained EAD chain model and a corresponding analytical model based on interaction between EAD aromatics and surface cations of a generic globular target. EAD-target binding, in the context of pathological Ewing's Sarcoma oncoproteins, is thus seen to be driven by a balance between EAD conformational entropy and favorable EAD-target cation-π contacts. Such a highly versatile mode of molecular recognition offers a general conceptual framework for promiscuous target recognition by polyvalent IDPs. © 2013 Song et al