End effects in low aspect ratio Taylor-Couette flow.

Taylor-Couette flow with a low aspect ratio cylinder suffers from end effects due to the finite-span of the gap between the cylinder sides and the secondary flow in the region below the inner cylinder. We experimentally explore these end effects by varying the cylinder aspect ratio between 6.67 and 40 for a range of wall gap widths and bottom gap heights. For these geometries, end effects (i.e. non-ideal Taylor-Couette flow) can be substantial due to both features of the finite-span and the bottom secondary flow. In some cases, the finite-span effects extended between 20% and 30% of the way into the Taylor-Couette flow region, and the secondary flow at the bottom accounted for nearly half of the total measured torque. By taking these effects into consideration, our high aspect ratio results agreed well with those obtained by Taylor (Taylor 1936 Proc. R. Soc. Lond. A 157, 546-564. (doi:10.1098/rspa.1936.0215)) at considerably higher aspect ratios. This article is part of the theme issue 'Taylor-Couette and related flows on the centennial of Taylor's seminal Philosophical Transactions paper (part 1)'.

Unmasking governance failures: The impact of COVID-19 on small-scale fishing communities in South Africa.

The COVID-19 pandemic has highlighted the pre-existing vulnerability of the small-scale fisheries sector in South Africa and exposed the structural inequalities and ongoing injustices facing this sector. The failures within the fisheries governance and management system linked to the slow pace of implementing the Small-scale Fisheries Policy of 2012, have further exacerbated their vulnerability. This paper explores the immediate impacts of the COVID-19 pandemic on the small-scale fisheries sector and exposes how governance failures within the fisheries sector have increased their vulnerability. Restrictions on fishing activities and mobility, closure of conservation areas, unfair fines and arrests, loss of markets and barriers to sale of fish products as well as lack of access to water, have had significant impacts on small-scale fishers and coastal communities. The lack of social protection and the limited emergency relief provided by government further exacerbated their precarious position. Despite their vulnerability, fishers have demonstrated a measure of resilience, supporting those in need with food, lobbying government to amend restrictions and recognise their rights, and challenging efforts to fast-track development and exclude their voices. The crisis has highlighted an urgent need for broad, national level transformation to deal with the poverty and injustices facing poor coastal communities, as well as fisheries-specific policy reform.

Two-dimensional flow and linear stability properties of smectic A liquid crystals.

We examine some leading-order flow and stability properties of smectic A (SmA) liquid crystals (LCs) in two spatial dimensions by analysing a fully nonlinear continuum theory of these materials. We derive a system of equations for the dynamic variables describing the flow velocity and orientation of the material under suitable assumptions upon these quantities. This system can provide insight into the leading-order behaviour under quite general circumstances, and we provide an example of utilising this system to determine the flow induced by a constant pressure gradient applied normally to the smectic layers. We then consider the effect of oscillatory perturbations on a relaxed, stationary sample of SmA, and provide criteria under which one would expect to see the onset of instability in the form of inequalities between the material parameters and perturbative wave number. We find that instability occurs for physically realisable values of these quantities, and, in particular, that certain viscosities characterising the SmA phase can act as 'destabilising agents' such that one could, for a given sample with known parameter values, manipulate the behaviour of that sample.

Short-Term Radiographic Outcomes of Calcaneus Fractures Treated With 2-Incision, Minimally Invasive Approach.

BACKGROUND: The treatment of displaced, intra-articular calcaneus fractures is controversial. The extensile lateral approach has been historically preferred because it provides excellent exposure and visualization for fracture reduction. However, soft tissue complications with this approach can lead to poor outcomes for patients. Recently, there has been an interest in the minimally invasive treatment of calcaneus fractures. The purpose of the present study was to determine the radiographic reduction of displaced, intra-articular calcaneus fractures and the rate of complications using a 2-incision, minimally invasive approach. METHODS: A dual-incision, minimally invasive approach with plate and screw fixation was utilized for the treatment of 32 patients with displaced, intra-articular calcaneus fractures. Preoperative and postoperative calcaneal measurements were taken to assess fracture reduction. Additionally, a retrospective chart review was performed to assess for complications. RESULTS: The mean preoperative Bohler's angle measurement was 12.9 (range, -5 to 36) degrees and the final postoperative Bohler's angle was 31.7 (range, 16-40) degrees. One patient (3.1%) had postoperative numbness related to the medial incision in the calcaneal branch sensory nerve distribution. Two patients (6.2%) had a wound infection treated with local wound care and oral antibiotics, while 1 patient (3.1%) had a deep infection that required a secondary surgery for irrigation and debridement. Two patients (6.2%) returned to the operating room for removal of symptomatic hardware. CONCLUSION: Operative fixation of displaced, intra-articular calcaneus fractures treated with a 2-incision, minimally invasive approach resulted in acceptable fracture reduction with a minimal rate of complications. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Unilateral open extravesical ureteral reimplanation with contralateral dextronomer/hyaluronic acid injection performed as an outpatient therapy.

INTRODUCTION: Historically, patients with unilateral high-grade vesicoureteral reflux (VUR) and contralateral low-grade or resolved VUR have been treated with bilateral intravesical ureteral reimplantation, which requires postoperative admission. If the high-grade VUR side is treated alone, then the contralateral side is at risk of developing recurrent or worsening VUR. Bilateral subureteric injection of dextronomer/hyaluronic acid (DHA) is another option that can be performed as an outpatient therapy, but a single injection is less effective for high-grade VUR. OBJECTIVE: The safety and efficacy of an outpatient combination of open extravesical ureteral reimplantation (EVUR) and contralateral DHA injection were investigated. STUDY DESIGN: A retrospective review of children who had concomitant EVUR and subureteric injection of DHA between January 2005 and December 2015 was performed. Exclusion criteria were diagnosis other than VUR, repeat procedures, and patients with no follow-up. Patient characteristics, postsurgical complications, and follow-up imaging were evaluated. Febrile urinary tract infection (fUTI) was defined as ≥50,000 Colony Forming Units (CFU) of an organism from clean-catch or catheterized urine and temperature ≥ 101.5 F. Clinical success is defined as no fUTI for 1 year after the initial operation. Univariate analyses were used to identify risk factors for treatment failure. RESULTS: A total of 117 patients met inclusion criteria. Mean age at surgery was 6.0 years, and 85% were female. The mean pre-operative grade of VUR was 3.3 on the EVUR side and 0.6 on the contralateral side (42% resolved before treatment). Median follow-up was 12.2 months (interquartile range, 3.1-25.4). Sixteen patients (14%) had documented fUTI within 1 year, with a clinical success rate of 86%. Of these, five had a postoperative imaging showing resolution of VUR, increasing overall success to 91%. Postoperative fUTI was more common in patients with pre-operative bowel and bladder dysfunction (BBD) (P = 0.003), but this was not associated with a higher reoperation rate (P = 0.168). There were 11 total complications, with three grade 3 complications. DISCUSSION: This study is the first to report safety and outcomes of EVUR and contralateral DHA injection for patients with high-grade VUR with contralateral low-grade or resolved VUR. It was shown that it is an effective and safe treatment that can be performed as an outpatient therapy. Limitations to this study include the retrospective design and the clinical definition of success that is used in a cohort of patients from across the mountain west region without routine postoperative voiding cystourethrogram. CONCLUSION: Extravesical ureteral reimplantation and contralateral DHA injection can safely be performed as an outpatient therapy and are effective in the treatment of higher grade VUR with contralateral low-grade or resolved VUR. Treatment failure is more likely in patients with BBD.

Configuration of a smectic A liquid crystal due to an isolated edge dislocation.

We discuss the static configuration of a smectic A liquid crystal subject to an edge dislocation under the assumption that the director and layer normal fields ([Formula: see text] and [Formula: see text], respectively) defining the smectic arrangement are not, in general, equivalent. After constructing the free energy for the smectic, we obtain exact solutions to the equilibrium equations which result from its minimisation at quadratic order in the variables which describe the distortion, and hence a complete description of the smectic configuration across the domain of the sample. We also examine the effect of relaxing the constraint [Formula: see text] for different values of the constants which characterise the response of the material to distortions, and compare these results with the 'classical' case considered by previous authors, in which equivalence of [Formula: see text] and [Formula: see text] is enforced.

Surgical Algorithm and Results of Isolated Traumatic Axillary Nerve Injuries.

BACKGROUND: Axillary nerve injuries are common and typically occur during high-energy, traumatic events. The purpose of this study is to propose a treatment algorithm for acute isolated axillary nerve injuries and report the outcomes of surgically treated patients. METHODS: A retrospective review identified 14 patients surgically treated for an isolated axillary nerve injury. Axillary nerve neurolysis was performed for all patients, and a triceps branch of the radial nerve was transferred to the axillary nerve in patients without evidence of deltoid function following intraoperative axillary nerve stimulation. Four patients were treated with neurolysis alone and 10 patients received a transfer. Pre- and postoperative deltoid strength, shoulder abduction, and the Disabilities of the Arm, Shoulder, and Hand (DASH) outcome score were evaluated. RESULTS: At most recent follow-up, both the neurolysis and nerve transfer groups had significant improvement in deltoid strength, with 86% achieving M4 or greater. Shoulder abduction improved from a mean of 63 to 127 degrees. This difference was significant in the nerve transfer group and when all patients were analyzed together. DASH scores significantly improved from a mean of 47 to 34 when all patients were analyzed together. No patients experienced a decrease in elbow extension strength following nerve transfer. CONCLUSIONS: In patients with preserved triceps strength, a triceps branch of the radial nerve can be coapted directly to the axillary nerve in the absence of deltoid contraction following electrical stimulation. Functional improvements were seen in patients treated with neurolysis alone and in combination with nerve transfer, supporting the use of intraoperative axillary nerve stimulation to guide treatment.

Idh1 protects murine hepatocytes from endotoxin-induced oxidative stress by regulating the intracellular NADP(+)/NADPH ratio.

Isocitrate dehydrogenase-1 (Idh1) is an important metabolic enzyme that produces NADPH by converting isocitrate to α-ketoglutarate. Idh1 is known to reduce reactive oxygen species (ROS) induced in cells by treatment with lipopolysaccharide (LPS) in vitro. Here, we used Idh1-deficient knockout (Idh1 KO) mice to investigate the role of Idh1 in antioxidant defense in vivo. Idh1 KO mice showed heightened susceptibility to death induced by LPS and exhibited increased serum levels of inflammatory cytokines such as tumor necrosis factor-α and interleukin-6. The serum of LPS-injected Idh1 KO mice also contained elevated levels of AST, a marker of inflammatory liver damage. Furthermore, after LPS injection, livers of Idh1 KO mice showed histological evidence of elevated oxidative DNA damage compared with livers of wild-type (WT) mice. Idh1 KO livers showed a faster and more pronounced oxidative stress than WT livers. In line with that, Idh1 KO hepatocytes showed higher ROS levels and an increase in the NADP(+)/NADPH ratio when compared with hepatocytes isolated from WT mice. These results suggest that Idh1 has a physiological function in protecting cells from oxidative stress by regulating the intracellular NADP(+)/NADPH ratio. Our findings suggest that stimulation of Idh1 activity may be an effective therapeutic strategy for reducing oxidative stress during inflammatory responses, including the early stages of septic shock.

Medical service redesign shares the load saving 6000 bed days and improving morale.

BACKGROUND AND AIMS: In 2010, demand on the Auckland City Hospital general medical service exceeded capacity. A review by the Royal Australasian College of Physicians was critical of training offered to registered medical officers, and low morale was a problem across the service. Management offered support for an improved model that would solve these problems. METHODS: A project to redesign the general medical service was undertaken. Baseline analysis found uneven workload and insufficient capacity at peak times for patient presentations. Workshops involving the entire service led to a new model that splits workload and teams into patients likely to have a short stay from those requiring longer, ward-based care. Admissions are now distributed over 12 teams on weekdays and 4 on the weekends. There was an increase of approximately 2.5 in consultant full time equivalents but no change in registrar or house officer staffing. RESULTS: Since the introduction of the new model, the average length of stay has fallen from 3.7 to 3.2 days (14%) and the median length of stay by 28%, resulting in a saving of 6000 bed days per year. Readmission, inpatient and 30-day mortality rates are unchanged. These results have been sustained over 18 months with signs of continuing improvement. CONCLUSION: This project owes its success to the following factors - management support; iterative engagement of a range of staff; provision of timely data analysis; increases in senior medical officer staffing and reorganisation leading to more predictable and fair work practices. One challenge is discontinuity, whether between doctors and patients or within the medical team.

Chemically induced twist-bend nematic liquid crystals, liquid crystal dimers, and negative elastic constants.

Here we report the chemical induction of the twist-bend nematic phase in a nematic mixture of ether-linked liquid crystal dimers by the addition of a dimer with methylene links; all dimers have an odd number of groups in the spacer connecting the two mesogenic groups. The twist-bend phase has been identified from its optical texture and x-ray scattering pattern as well as NMR spectroscopy, which demonstrates the phase chirality. Theory predicts that the key macroscopic property required for the stability of this chiral phase formed from achiral molecules is for the bend elastic constant to tend to be negative; in addition the twist elastic constant should be smaller than half the splay elastic constant. To test these important aspects of the prediction we have measured the bend and splay elastic constants in the nematic phase preceding the twist-bend nematic using the classic Frederiks methodology and all three elastic constants employing the dynamic light scattering approach. Our results show that, unlike the splay, the bend elastic constant is small and decreases significantly as the transition to the induced twist-bend nematic phase is approached, but then exhibits unexpected behavior prior to the phase transition.

Use of antipsychotic medications in patients with Parkinson's disease at Auckland City Hospital.

BACKGROUND: The American Academy of Neurology considers clozapine first line treatment for psychosis in Parkinson's disease (PD). In practice, patients are typically treated with quetiapine initially despite only level C evidence for use due to concern about side-effects, and changed to clozapine if they fail this. AIM: To review the use of antipsychotics in patients with PD and the demographics of PD patients who develop psychosis. METHODS: Patients with PD on antipsychotic medications were identified by the Movement Disorder Nurse Specialist database and by reviewing patients admitted to Auckland City Hospital from January 2006 until March 2008. The demographic data, details of PD and antipsychotic use and comorbidities were recorded. RESULTS: Sixty-six patients with PD on antipsychotics were identified. The mean age was 75 years and 48 (73%) were in residential care. Patients admitted on antipsychotics had longer disease duration (P < 0.001) and were more likely to have cognitive impairment (P= 0.02) than those admitted not on antipsychotics. The most common indication for use was hallucinations. Patients on clozapine were younger (P < 0.005) and had less comorbidity (P= 0.04) than those on quetiapine. Fifty per cent (6/12) of patients on clozapine had previously failed quetiapine. CONCLUSION: Quetiapine has a good efficacy rate with minimal side-effects. This study lends support to the assumption that quetiapine is a useful medication. However, clozapine also was well tolerated and could be considered for use more frequently than it is.

Non-invasive vesicoureteral reflux detection: heating risk studies for a new device.

OBJECTIVE: To investigate a novel non-invasive device developed to warm bladder urine and to measure kidney temperature to detect vesicoureteral reflux. MATERIALS AND METHODS: Microwave antennas focused energy within the bladder. Phantom experiments measured the results. The heating protocol was optimized in an in-vivo porcine model, and then tested once, twice and three times consecutively in three pigs followed by pathologic examinations. RESULTS: Computer simulations showed a dual concentric conductor square slot antenna to be the best. Phantom studies revealed that this antenna easily heated a bladder phantom without over heating intervening layers. In-vivo a bladder heating protocol of 3 min with 30 W each to two adjacent antennas 45 s on 15 s off followed by 15 min of 15 s on and 45 s off was sufficient. When pigs were heated once, twice and three times with this heating protocol, pathologic examination of all tissues in the heated area showed no thermal changes. More intensive heating in the animal may have resulted in damage to muscle fibers in the anterior abdominal wall. CONCLUSIONS: Selective warming of bladder urine was successfully demonstrated in phantom and animals. Localized heating for this novel vesicoureteral reflux device requires low-power levels and should be safe for humans.

Botulinum toxin assessment, intervention and after-care for upper limb hypertonicity in adults: international consensus statement.

Upper limb spasticity affecting elbow, wrist, and finger flexors can be safely and effectively reduced with injections of botulinum toxin type-A (BoNT-A). It has been best studied in adults in the context of post-stroke spasticity. The clinical benefits include reduction in pain and deformity, improvement in washing and dressing the upper limb, and a reduction in caregiver burden (Class I evidence, recommendation level A). Some patients show improvement in function performed by active movement of the affected upper limb (Class III evidence, recommendation C), but predicting and measuring this is difficult, and further research is needed. An individually based approach to treatment and outcome measurement is preferred (Class IV, recommendation U). More research is needed to resolve many unknown issues of assessment and treatment, using research methods appropriate to the question.

Haplotypes and gene expression implicate the MAPT region for Parkinson disease: the GenePD Study.

BACKGROUND: Microtubule-associated protein tau (MAPT) has been associated with several neurodegenerative disorders including forms of parkinsonism and Parkinson disease (PD). We evaluated the association of the MAPT region with PD in a large cohort of familial PD cases recruited by the GenePD Study. In addition, postmortem brain samples from patients with PD and neurologically normal controls were used to evaluate whether the expression of the 3-repeat and 4-repeat isoforms of MAPT, and neighboring genes Saitohin (STH) and KIAA1267, are altered in PD cerebellum. METHODS: Twenty-one single-nucleotide polymorphisms (SNPs) in the region of MAPT on chromosome 17q21 were genotyped in the GenePD Study. Single SNPs and haplotypes, including the H1 haplotype, were evaluated for association to PD. Relative quantification of gene expression was performed using real-time RT-PCR. RESULTS: After adjusting for multiple comparisons, SNP rs1800547 was significantly associated with PD affection. While the H1 haplotype was associated with a significantly increased risk for PD, a novel H1 subhaplotype was identified that predicted a greater increased risk for PD. The expression of 4-repeat MAPT, STH, and KIAA1267 was significantly increased in PD brains relative to controls. No difference in expression was observed for 3-repeat MAPT. CONCLUSIONS: This study supports a role for MAPT in the pathogenesis of familial and idiopathic Parkinson disease (PD). Interestingly, the results of the gene expression studies suggest that other genes in the vicinity of MAPT, specifically STH and KIAA1267, may also have a role in PD and suggest complex effects for the genes in this region on PD risk.

Graduated compression stockings: physiological and perceptual responses during and after exercise.

The aim of this study was to examine the effect of wearing graduated compression stockings on physiological and perceptual variables during and after intermittent (Experiment 1) and continuous (Experiment 2) running exercise. Fourteen recreational runners performed two multi-stage intermittent shuttle running tests with 1 h recovery between tests (Experiment 1). A further 14 participants performed a fast-paced continuous 10-km road run (Experiment 2). Participants wore commercially available knee-length graduated compression stockings (pressure at ankle 18 - 22 mmHg) beneath ankle-length sports socks (experimental trials) or just the latter (control trials) in a randomized counterbalanced design (for both experiments). No performance or physiological differences were observed between conditions during intermittent shuttle running. During the 10-km trials, there was a reduction in delayed-onset muscle soreness 24 h after exercise when wearing graduated compression stockings (P < 0.05). There was a marked difference in the frequency and location of soreness: two participants in the stockings trial but 13 participants in the control trial indicated soreness in the lower legs. Wearing graduated compression stockings during a 10-km road run appears to reduce delayed-onset muscle soreness after exercise in recreationally active men.

Line defects and temperature effects in liquid crystal tunable planar Bragg gratings.

Liquid crystal tunable planar Bragg Gratings produced by Direct UV Writing are capable of wavelength tuning of over 100GHz. However, such devices exhibit non-linear tuning curves with threshold points and hysteresis. We show that these effects are due to the formation of disclination structures in the liquid crystal and discuss the role of electrode defects and sample temperature on wavelength tuning.

Vsx1, a rapidly evolving paired-like homeobox gene expressed in cone bipolar cells.

The paired-like homeodomain (HD) protein Chx10 is distinguished by the presence of the CVC domain, a conserved 56 amino acid sequence C-terminal to the HD. In mammals, Chx10 is essential both for the proliferation of retinal progenitor cells and for the formation or survival of retinal bipolar interneurons. We describe the cloning and characterization of a mouse Chx10 homologue, Vsx1; phylogenetic analysis suggests that Vsx1 and its putative vertebrate orthologues have evolved rapidly. Vsx1 expression in the adult is predominantly retinal. Whereas Chx10 is expressed both in retinal progenitors in the developing eye and apparently in all bipolar cells of the mature retina, Vsx1 expression is first detected in the eye at postnatal day 5, where it is restricted to cone bipolar cells.

Regulation of PTEN transcription by p53.

PTEN tumor suppressor is frequently mutated in human cancers and is a negative regulator of PI3'K/PKB/Akt-dependent cellular survival. Investigation of the human genomic PTEN locus revealed a p53 binding element directly upstream of the PTEN gene. Deletion and mutation analyses showed that this element is necessary for inducible transactivation of PTEN by p53. A p53-independent element controlling constitutive expression of PTEN was also identified. In contrast to p53 mutant cell lines, induction of p53 in primary and tumor cell lines with wild-type p53 increased PTEN mRNA levels. PTEN was required for p53-mediated apoptosis in immortalized mouse embryonic fibroblasts. Our results reveal a unique role for p53 in regulation of cellular survival and an interesting connection in tumor suppressor signaling.