AC electrokinetics is the study of the movement of polarisable particles under the influence of AC electric fields. The fields are applied to a suspension of particles by planar microelectrode ...structures and one particular design, the interdigitated bar electrode has been used in both dielectrophoretic (DEP) field flow fractionation and travelling wave dielectrophoresis. This paper presents, numerical solutions of the DEP and travelling wave forces for an interdigitated electrode array energised with either a 2- or 4-phase signal. The electrorotational torque experienced by the particle in the 4-phase travelling wave array is also calculated. The solutions are compared with previous results.
When measuring the dielectric properties of aqueous samples, the impedance of the electrode/sample interface can limit low frequency measurements. The electrode polarization problem can be reduced by ...increasing the effective surface area of the electrodes. In this work, impedance spectroscopy was used to characterize and compare three different electrode surfaces that can be used to mitigate this effect: platinum black, iridium oxide, and polypyrrole/poly(styrenesulphonate) (PPy/PSS) conducting polymer. All three materials were directly compared with a bright platinum electrode. Equivalent circuit models were used to extract the increase in the effective surface area of the electrodes: platinum black, iridium oxide and PPy/PSS increase the effective capacitance of the electrode by factors of approximately 240, 75, and 790, respectively. The practical aspects of all electrode materials are discussed. These results suggest that iridium oxide and PPy/PSS are good alternatives to the commonly used platinum black, which is prone to mechanical damage (scratches) and is potentially toxic to cells.
CASE DESCRIPTION A 62-year-old African American woman on dialysis with a medical history notable for end-stage renal disease, congestive heart failure, diabetes mellitus, hypertension, and possible ...sarcoidosis presented to the hospital with an altered mental status after experiencing a fall that broke her wrist.
Although bovine respiratory disease complex (BRDC) is common in post-weaning cattle, BRDC prediction models are seldom analyzed. The objectives of this study were to assess the ability to predict ...cumulative cohort-level BRDC morbidity using on-arrival risk factors and to evaluate whether or not adding BRDC risk classification and daily BRDC morbidity and mortality data to the models enhanced their predictive ability. Retrospective cohort-level and individual animal health data were used to create mixed negative binomial regression (MNBR) models for predicting cumulative risk of BRDC morbidity. Logistic regression models were used to illustrate that the percentage of correctly (within |5%| of actual) classified cohorts increased across days, but the effect of day was modified by arrival weight, arrival month, and feedlot. Cattle arriving in April had the highest (77%) number of lots correctly classified at arrival and cattle arriving in December had the lowest (28%). Classification accuracy at arrival varied according to initial weight, ranging from 17% (< 182 kg) to 91% (> 409 kg). Predictive accuracy of the models improved from 64% at arrival to 74% at 8 days on feed (DOF) when risk code was known compared to 56% accuracy at arrival and 69% at 8 DOF when risk classification was not known. The results of this study demonstrate how the predictive ability of models can be improved by utilizing more refined data on the prior history of cohorts, thus making these models more useful to operators of commercial feedlots.
Eccrine porocarcinomas (EPs) are rare malignant tumours of the intraepidermic sweat gland duct and most often arise from benign eccrine poromas. Some recurrent somatic genomic events have been ...identified in these malignancies, but very little is known about the complexity of their molecular pathophysiology. We describe the whole genome and whole transcriptome genomic profiling of a metastatic EP in a 66-year-old male patient with a previous history of localized porocarcinoma of the scalp. Whole genome and whole transcriptome genomic profiling was performed on the metastatic EP. Whole genome sequencing was performed on blood-derived DNA in order to allow a comparison between germline and somatic events. We found somatic copy losses of several tumour suppressor genes including
,
and
,
and
. We identified a somatic hemizygous
pathogenic splice site variant. De novo transcriptome assembly revealed abnormal splicing of
p14
and p16
. Elevated expression of oncogenes
and
was noted and no somatic mutations were found in these genes. Wnt pathway somatic alterations were also observed. In conclusion, our results suggest that the molecular pathophysiology of malignant EP features high complexity and subtle interactions of multiple key genes. Cell cycle dysregulation and
loss of function was found to be a new potential driver in EP tumourigenesis. Moreover, the combination of somatic copy number variants and abnormal gene expression perhaps partly related to epigenetic mechanisms, all likely contribute to the development of this rare malignancy in our patient.
Parkinson's disease is a common age-related neurodegenerative disorder affecting 10 million people worldwide, but the mechanisms underlying its pathogenesis are still unclear. The disease is ...characterised by dopamine nerve cell loss in the mid-brain and intra-cellular accumulation of α-synuclein that results in motor and non-motor dysfunction. In this review, we discuss the neuroprotective effects of the stomach hormone, ghrelin, in models of Parkinson's disease. Recent findings suggest that it may modulate mitochondrial function and autophagic clearance of impaired organelle in response to changes in cellular energy balance. We consider the putative cellular mechanisms underlying ghrelin-action and the possible role of ghrelin mimetics in slowing or preventing Parkinson's disease progression.
This article is part of the Special Issue entitled ‘Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.’
It is well known that glaucoma results in performance impairments on tasks processed early in the visual pathways. Glaucoma should also impair cortical visual processing because of reduced input from ...retinal ganglion cells and also possibly because of abnormal cortical function. This study was undertaken to assess whether cortically processed global percepts are disrupted in glaucoma in areas of visual field classified as normal by standard automated perimetry (SAP). Performance on global tasks (motion and form) was compared to measures of presumed precortical magnocellular and parvocellular function in the same individuals.
Fifteen control subjects and 12 patients with primary open-angle glaucoma participated. Testing was performed foveally and midperipherally (12.5 degrees). Contrast-discrimination thresholds were measured by using the steady-pedestal (magnocellular) and pulsed-pedestal (parvocellular) contrast-discrimination tasks of Pokorny and Smith. Global motion coherence and global form coherence thresholds were measured at high and low contrast.
Patients with glaucoma demonstrated higher global motion and form-coherence thresholds than did control subjects for targets presented in the midperiphery (P < 0.05), but not foveally. Different individuals performed poorly on the motion and form tasks. The subjects with the greatest presumed magnocellular and parvocellular loss were those with the largest deficits on the global motion and form tasks, respectively.
Some subjects with glaucoma demonstrate profound impairments of global motion or global form integration in areas of visual field classified as normal by SAP. This finding implies that some people with glaucoma may have far greater difficulty with complex visual tasks (for example, navigation through the environment or face recognition) than is predicted by their visual field loss.
Objective
Unintentional injuries, the leading cause of death for American children, are caused by a range of psychosocial factors, including risk behavior. One factor that may impact child ...risk-taking is modeling of superhuman risk-taking from superhero media, both immediately following superhero exposure and based on lifetime exposure and engagement.
Methods
Fifty-nine 5-year-olds were randomly assigned to view either a 13-min age-appropriate superhero television show or a comparable nonsuperhero show. After the viewing, children engaged in three risk-taking measures: (a) activity room, unsupervised play for 5 min with assortment of apparently dangerous items that might encourage child risk-taking; (b) picture sort, 10 illustrations of children in risk situations, with participant response concerning intended risk-taking in that situation; and (c) vignettes, 10 stories presenting situations with varying degrees of risk, with participant response on intended choice. Parents completed questionnaires concerning children’s long-term superhero media exposure and individual superhero engagement (e.g., if child’s most recent Halloween costume was of a superhero). Correlations and regressions evaluated effects of immediate superhero exposure, lifetime superhero exposure, and lifetime superhero engagement on children’s risk-taking.
Results
Mixed results emerged. Lifetime superhero exposure was significantly related to children’s risk-taking outcomes in two bivariate (vignettes and picture sort) and one multivariate (picture sort) model. Neither immediate superhero exposure nor lifetime superhero engagement was strongly related to risk-taking.
Conclusions
Children’s lifetime superhero exposure may influence children’s risk-taking. Given American children’s substantial media exposure, research should continue to unpack the role of superhero media on children’s unintentional injury and other health risk behaviors.
Surgeon-specific outcome monitoring has become increasingly prevalent over the last 3 decades. The New Zealand Orthopaedic Association monitors individual surgeon performance through 2 mechanisms: ...arthroplasty revision rates derived from the New Zealand Joint Registry and a practice visit program. Despite remaining confidential, surgeon-level outcome reporting remains contentious. The purpose of this survey was to evaluate the opinions of hip and knee arthroplasty surgeons in New Zealand on the perceived importance of outcome monitoring, current methods used to evaluate surgeon-specific outcomes, and potential improvements identified through literature review and discussion with other registries.
The survey consisted of 9 questions on surgeon-specific outcome reporting, using a five-point Likert scale, and 5 demographic questions. It was distributed to all current hip and knee arthroplasty surgeons. There were 151 hip and knee arthroplasty surgeons who completed the survey, a response rate of 50%.
Respondents agreed that monitoring arthroplasty outcomes is important and that revision rates are an acceptable measure of performance. Reporting risk-adjusted revision rates and more recent timeframes were supported, as was including patient-reported outcomes when monitoring performance. Surgeons did not support public reporting of surgeon-level or hospital-level outcomes.
The findings of this survey support the use of revision rates to confidentially monitor surgeon-level arthroplasty outcomes and suggest that concurrent use of patient-reported outcome measures would be acceptable.
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