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Objectives: This study aimed to evaluate the influence of lower limb loss (LL) on mental workload by assessing neurocognitive measures in individuals with unilateral transtibial (TT) versus those with transfemoral (TF) LL while dual-task walking under varying cognitive demand. Methods: Electroencephalography (EEG) was recorded as participants performed a task of varying cognitive demand while being seated or walking (i.e., varying physical demand). Results: The findings revealed both groups of participants (TT LL vs. TF LL) exhibited a similar EEG theta synchrony response as either the cognitive or the physical demand increased. Also, while individuals with TT LL maintained similar performance on the cognitive task during seated and walking conditions, those with TF LL exhibited performance decrements (slower response times) on the cognitive task during the walking in comparison to the seated conditions. Furthermore, those with TF LL neither exhibited regional differences in EEG low-alpha power while walking, nor EEG high-alpha desynchrony as a function of cognitive task difficulty while walking. This lack of alpha modulation coincided with no elevation of theta/alpha ratio power as a function of cognitive task difficulty in the TF LL group. Conclusions: This work suggests that both groups share some common but also different neurocognitive features during dual-task walking. Although all participants were able to recruit neural mechanisms critical for the maintenance of cognitive-motor performance under elevated cognitive or physical demands, the observed differences indicate that walking with a prosthesis, while concurrently performing a cognitive task, imposes additional cognitive demand in individuals with more proximal levels of amputation.
We provide an update on diagnostic methods for the detection of urogenital schistosomiasis (UGS) in men and highlight that satisfactory urine-antigen diagnostics for UGS lag much behind that for intestinal schistosomiasis, where application of a urine-based point-of-care strip assay, the circulating cathodic antigen (CCA) test, is now advocated. Making specific reference to male genital schistosomiasis (MGS), we place greater emphasis on parasitological detection methods and clinical assessment of internal genitalia with ultrasonography. Unlike the advances made in defining a clinical standard protocol for female genital schistosomiasis, MGS remains inadequately defined. Whilst urine filtration with microscopic examination for ova of Schistosoma haematobium is a convenient but error-prone proxy of MGS, we describe a novel low-cost sampling and direct visualization method for the enumeration of ova in semen. Using exemplar clinical cases of MGS from our longitudinal cohort study among fishermen along the shoreline of Lake Malawi, the portfolio of diagnostic needs is appraised including: the use of symptomatology questionnaires, urine analysis (egg count and CCA measurement), semen analysis (egg count, circulating anodic antigen measurement and real-time polymerase chain reaction analysis) alongside clinical assessment with portable ultrasonography.
Tonsillectomy is one of the most common otolaryngological procedures. Nonetheless, there is still no universally approved ‘gold standard’ technique.
To compare the safety and efficacy of argon plasma coagulation and coblation techniques in tonsillectomy.
A multi-institutional, retrospective cohort study was conducted, comprising 283 patients who underwent bilateral tonsillectomies performed by a single surgeon between 2014 and 2017. The outcome measures included: operative time, intra-operative blood loss, post-operative pain and post-operative haemorrhage.
In the argon plasma coagulation group, mean operative time and post-operative haemorrhage rate were significantly reduced, p = 0.0006 and p = 0.003 respectively. There was no statistically significant difference between the two groups in terms of post-operative pain and intra-operative blood loss.
The argon plasma coagulation technique is easy, safe and efficacious. Argon plasma coagulation tonsillectomy seems cost-effective compared to coblation tonsillectomy: the single-use disposable electrode tip and wand used in this study cost AUD$76.50 and AUD$380 respectively. Argon plasma coagulation appears to be a favourable alternative to current modalities such as coblation.
One of the key problems in the development of morphing aircraft is the morphing structure, which should be able to carry loads and change its geometry simultaneously. This paper investigates a compliant structure, which has the potential to change the dihedral angle of morphing wing-tip devices. The compliant structure is able to induce deformation by unsymmetrical stiffness allocation and carry aerodynamic loads if the total stiffness of the structure is sufficient.
The concept has been introduced by building a simplified model of the structure and deriving the analytical equations. However, a properly designed stiffness asymmetry, which is optimised, can help to achieve the same deformation with a reduced actuation force.
In this paper, round corrugated panels are used in the compliant structure and the stiffness asymmetry is introduced by changing the geometry of the corrugation panel. A new equivalent model of the round corrugated panel is developed, which takes the axial and bending coupling of the corrugated panel into account. The stiffness matrix of the corrugated panel is obtained using the equivalent model, and then the deflections of the compliant structure can be calculated. The results are compared to those from detailed finite element models built in the commercial software Abaqus. Samples with different geometries were manufactured for experimental tests.
After verifying the equivalent model, optimisation is performed to find the optimum geometries of the compliant structures. The actuation force of a single compliant structure is first optimised, and then the optimisation is performed for a compliant structure consisting of multiple units. A case study is used to show the performance improvement obtained.
Fatigue cracking in polycrystalline NiTi was investigated using a multiscale experimental framework for average grain sizes (GS) from 10 to 1500 nm for the first time. Macroscopic fatigue crack growth rates, measured by optical digital image correlation, were connected to microscopic crack opening and closing displacements, measured by scanning electron microscope DIC (SEM-DIC) using a high-precision external SEM scan controller. Among all grain sizes, the 1500 nm GS sample exhibited the slowest crack growth rate at the macroscale, and the largest crack opening level (stress intensity at first crack opening) and minimum crack opening displacements at the microscale. Smaller GS samples (10, 18, 42, and 80 nm) exhibited nonmonotonic trends in their fatigue performance, yet the correlation was strong between macroscale and microscale behaviors for each GS. The samples that exhibited the fastest crack growth rates (42 and 80 nm GS) showed a small crack opening level and the largest crack opening displacements. The irregular trends in fatigue performance across the nanocrystalline GS samples were consistent with nonmonotonic values in the elastic modulus reported previously, both of which may be related to the presence of residual martensite only evident in the small GS samples (10 and 18 nm).
We analyse the displacement of one fluid by a second immiscible fluid through a narrow channel of finite length which connects two reservoirs. We assume that the channel width slowly decreases in the direction of flow, and that the fluids have different viscosity and density. We examine the stability of the interface and find that there are Saffman–Taylor and Rayleigh–Taylor type modes, which may dominate in the narrow and wide regions of the channel, respectively. The gradient of the pressure jump across the interface associated with the surface tension acts to stabilise the interface, and for intermediate channel widths, this effect may dominate the destabilisation associated with both the Rayleigh–Taylor and Saffman–Taylor instabilities, provided the rate of change of the channel width with distance along the channel is sufficient. We also note that the effect of the converging channel leads to instability of long-wavelength modes owing to the quasi-static acceleration of the flow through the cell: we consider cases in which this effect only occurs at much lower wavenumbers than the most unstable Saffman–Taylor and Rayleigh–Taylor modes. We show that there is a maximum wavenumber for instability, which varies with position in the channel. By integrating the growth rate of each wavenumber in time as the interface moves across the channel, we predict the mode which grows to the greatest amplitude as the interface traverses the channel.
Acute mastoiditis remains the commonest intratemporal complication of otitis media in the paediatric population. There has been a lack of consensus regarding the diagnosis and management of acute mastoiditis, resulting in considerable disparity in conservative and surgical management.
To review the current literature, proposing recommendations for the management of paediatric acute mastoiditis and appraising the treatment outcomes.
A systematic review was conducted using PubMed, Web of Science and Cochrane Library databases.
Twenty-one studies were included, with a total of 564 patients. Cure rates of medical treatment, conservative surgery and mastoidectomy were 95.9 per cent, 96.3 per cent and 89.1 per cent, respectively.
Mastoidectomy may be the most definitive treatment available; however, reviewed data suggest that conservative treatment alone has high efficacy as first-line treatment in uncomplicated cases of acute mastoiditis, and conservative therapy may be an appropriate first-line management when treating acute mastoiditis.
Producers of food have always been troubled with weeds. Hand labor was the primary source of weed control for centuries, and selective weed control was not achieved until copper sulphate was used to control mustard (Brassica spp.) in wheat (Triticum aestivum L.) in 1896 (4, 42). Adequate crop selectivity was usually difficult to obtain with herbicides during the first 40 yr of the 20th century and the cost of the early herbicides was high.
The people of the world required from the dawn of time until 1830 to reach a population of 1 billion. By 1960, we reached 3 billion and by 1980 we had a population of about 4 billion. It is estimated that by the year 2000 there will be 7 billion people in the world. Just 30 yr from now the world's population will have doubled. This means that within the next 30 yr we must produce as much food as we have produced since the beginning of history. Can we feed this many people? Yes, but expanded research to develop improved technology will be required to meet the challenge.
Although high dose n-3 PUFA supplementation reduces exercise- and hyperpnoea-induced bronchoconstriction (EIB/HIB), there are concurrent issues with cost, compliance and gastrointestinal discomfort. It is thus pertinent to establish the efficacy of lower n-3 PUFA doses. Eight male adults with asthma and HIB and eight controls without asthma were randomly supplemented with two n-3 PUFA doses (6·2 g/d (3·7 g EPA and 2·5 g DHA) and 3·1 g/d (1·8 g EPA and 1·3 g DHA)) and a placebo, each for 21 d followed by 14 d washout. A eucapnic voluntary hyperpnoea (EVH) challenge was performed before and after treatments. Outcome measures remained unchanged in the control group. In the HIB group, the peak fall in forced expiratory volume in 1 s (FEV1) after EVH at day 0 (−1005 (sd 520) ml, −30 (sd 18) %) was unchanged after placebo. The peak fall in FEV1 was similarly reduced from day 0 to day 21 of 6·2 g/d n-3 PUFA (−1000 (sd 460) ml, −29 (sd 17) % v. −690 (sd 460) ml, −20 (sd 15) %) and 3·1 g/d n-3 PUFA (−970 (sd 480) ml, −28 (sd 18) % v. −700 (sd 420) ml, −21 (sd 15) %) (P<0·001). Baseline fraction of exhaled nitric oxide was reduced by 24 % (P=0·020) and 31 % (P=0·018) after 6·2 and 3·1 g/d n-3 PUFA, respectively. Peak increases in 9α, 11β PGF2 after EVH were reduced by 65 % (P=0·009) and 56 % (P=0·041) after 6·2 and 3·1 g/d n-3 PUFA, respectively. In conclusion, 3·1 g/d n-3 PUFA supplementation attenuated HIB and markers of airway inflammation to a similar extent as a higher dose. Lower doses of n-3 PUFA thus represent a potentially beneficial adjunct treatment for adults with asthma and EIB.
This study details the characterization of a glass sample exposed to hyperalkaline water and calcium-rich sediment for an extended time period (estimated as 2 - 70 years) at a lime (CaO) waste site in the UK. We introduce this site, known as Peak Dale, in reference to its use as a natural analogue for nuclear waste glass dissolution in the high pH environment of a cementitious engineered barrier of a geological disposal facility. In particular, a preliminary assessment of alteration layer chemistry and morphology is described and the initiation of a long-term durability assessment is outlined.
Polypharmacy is growing in Canada, along with adverse drug events and drug-related costs. Part of the solution may be deprescribing, the planned and supervised process of dose reduction or stopping of medications that may be causing harm or are no longer providing benefit. Deprescribing can be a complex process, involving the intersection of patients, health care providers, and organizational and policy factors serving as enablers or barriers. This article describes the justification, theoretical foundation, and process for developing a Canadian Deprescribing Network (CaDeN), a network of individuals, organizations, and decision-makers committed to promoting the appropriate use of medications and non-pharmacological approaches to care, especially among older people in Canada. CaDeN will deploy multiple levels of action across multiple stakeholder groups simultaneously in an ecological approach to health system change. CaDeN proposes a unique model that might be applied both in national settings and for different transformational challenges in health care.
A population of junglerice from Sunflower County, MS, exhibited resistance to fenoxaprop-P-ethyl. An 11-fold difference in ED50 (the effective dose needed to reduce growth by 50%) values was observed when comparing the resistant population (249 g ae ha–1) with susceptible plants (20 g ae ha–1) collected from a different field. The resistant population was controlled by clethodim and sethoxydim at the field rate. Sequencing of the acetyl coenzyme A carboxylase, which encodes the enzyme targeted by fenoxaprop-P-ethyl, did not reveal the presence of any known resistance-conferring point mutations. An enzyme assay confirmed that the acetyl coenzyme A carboxylase in the resistant population is herbicide sensitive. Further investigations with two cytochrome P450 inhibitors, malathion and piperonyl butoxide, and a glutathione-S-transferase inhibitor, 4-chloro-7-nitrobenzofurazan, did not indicate involvement of any metabolic enzymes inhibited by these compounds. The absence of a known target-site point mutation and the sensitivity of the ACCase enzyme to herbicide show that fenoxaprop-P-ethyl resistance in this population is due to a non–target-site mechanism or mechanisms.
There is a paucity of information on the risk from potable water in non-passenger merchant vessels (NPMVs) particularly with regard to Legionella and other bacteria. This retrospective study examined water samples from 550 NPMVs docked in eight UK ports. A total of 1027 samples from 412 NPMVs were examined for total aerobic colony counts (ACC), coliforms, Escherichia coli and enterococci; 41% of samples yielded ACC above the action level (>1 × 103 c.f.u./ml) and 4·5% contained actionable levels (>1 c.f.u./100 ml) of faecal indicator bacteria. Eight hundred and three samples from 360 NPMVs were cultured specifically for Legionella and 58% of vessels proved positive for these organisms with 27% of samples showing levels greater than the UK upper action limit of 1 × 103 c.f.u./l. Cabin showers (49%) and hospital shower (45%) were frequently positive. A subset of 106 samples was analysed by quantitative polymerase chain reaction for Legionella and identified a further 11 Legionella-positive NPMVs, returning a negative predictive value of 100%. There was no correlation between NPMV age or size and any microbial parameters (P > 0·05). Legionella pneumophila serogroup 1 was isolated from 46% of NPMVs and sequence-based typing of 17 isolates revealed four sequence types (STs) previously associated with human disease. These data raise significant concerns regarding the management of microbial and Legionella risks on board NPMVs and suggest that better guidance and compliance are required to improve control.