Variation in duplex peak systolic velocity measurement in a multi-site vascular service

Objective:

Duplex US (DUS) is increasingly utilised as a first-line investigation for the assessment of carotid disease. For clinical decision-making, DUS assessment must be accurate and reproducible to ensure reliability. We aimed to investigate the variability in peak systolic velocity (PSV) measurement in a multi-site vascular network.

Methods:

DUS measurements of PSV were taken from continuous and pulsatile flow, generated by a high fidelity phantom, by 12 experienced vascular scientists across four hospitals. Participants were blinded to the actual PSV value (50 cm/s).

Results:

We observed an average error of 13.2% (± 8.3) and 11.6% (± 7.5) in PSV measurements taken from pulsatile and continuous waveforms, respectively. Measurements of PSV using the pulsatile waveform demonstrated statistically significant variation across all hospitals; ((hospital/mean) A 43.9 cm/s, B 61.7 cm/s, C 57.4 cm/s, D 47.7 cm/s, p=0.001). Further analysis demonstrated statistically significant variation in 4 instrumentation-related factors when measuring from a pulsatile waveform (Doppler angle, angle of insonation, velocity range, scale range).

Conclusion:

We observed a significant level of error and variation in PSV measurements across four sites within our vascular network. Variation in instrumentation-related factors may be accountable for this. In light of the centralisation of vascular services, it is increasingly important to unify and implement scanning protocols in order to reduce error and inter-site variability.

Rangeland Rummy - a board game to support adaptive management of rangeland-based livestock systems

Rangeland-based livestock systems have to deal with the significant instability and uncertainty of the agricultural context (policy changes, volatility of input prices, etc.), and especially of the climatic context. Thus, they are particularly concerned by adaptive management strategies. To support the development of such strategies, we developed a board game including a computer model called "Rangeland Rummy". It is to be used by groups of farmers and agricultural consultants in the context of short workshops (about 3 h). Rangeland Rummy builds upon five types of material object: (i) a game board; (ii) a calendar stick indicating the starting date of the game board; (iii) sticks marked with the feed resources available for combinations of vegetation types and their management practices; (iv) cards to define animal groups and their feeding requirements throughout the year; (v) cards related to types of feed that can be attributed to animal groups throughout the year. Using these material objects, farmers collectively design a rangeland-based livestock system. This system is immediately evaluated using a computer model, i.e. a spreadsheet providing graphs and indicators providing information on, among other things, the extent to which quantitative and qualitative animal feeding requirements are covered across the year. Playing the game thus consists in collectively and iteratively designing and evaluating rangeland-based livestock systems, while confronting the players with new contextual challenges (e.g. interannual variability of weather, volatility of input prices) or new farmers' objectives (e.g. being self-sufficient for animal feeding). An example of application of Rangeland Rummy with 3 farmers in southern France is reported. Applications show that it tends to develop farmers' adaptive capacity by stimulating their discussions and the exchange of locally-relevant knowledge on management strategies and practices in rangeland-based livestock systems.

Psychotic experiences and psychological distress predict contemporaneous and future non-suicidal self-injury and suicide attempts in a sample of Australian school-based adolescents

BACKGROUND

Recent cross-sectional studies have shown psychotic experiences (PEs) are associated with suicidal ideation and behaviours. We aimed to examine associations between psychotic experiences (including persistent PE), and contemporaneous and incident non-suicidal self-injury (NSSI) and suicide attempts.

METHOD

Participants were from an Australian longitudinal cohort of 1896 adolescents (12-17 years). NSSI and suicide attempts were measured using the Self-Harm Behaviour Questionnaire. Items from the Diagnostic Interview Schedule for Children were used to assess psychotic experiences, and the General Health Questionnaire-12 measured psychological distress.

RESULTS

Adolescents both psychologically distressed and endorsing psychotic experiences had increased odds of contemporaneous and incident NSSI and attempted suicide. Psychotic experiences alone did not predict future risk. Persistent psychotic experiences were associated with increased risk of NSSI and suicide attempts.

CONCLUSIONS

Psychological distress with accompanying psychotic experiences and persistent psychotic experiences are important predictors of NSSI and suicide attempts. Screening these phenotypes in adolescents will assist in discerning those adolescents most at risk, providing opportunities for targeted suicide prevention strategies.

Development of a real-time PCR for Escherichia coli based on gadE, an acid response regulatory gene

Increasingly, molecular methods have become important in identification and confirmation of bacteria at the species level. Rapid molecular methods provide sensitivity and specificity while reducing cost and resources. The primary goal of this study was to develop a real-time PCR assay for identification of Escherichia coli from an agar plate. GadE (gadE) directly regulates the glutamate-dependent acid response system (GDAR) in E. coli and is responsible for survival of at pH 2. Based on gene sequence data, a real-time PCR assay targeting gadE was developed for this purpose. Seventy bacterial isolates recovered from ground beef enrichments and 714 isolates from caecal contents were identified biochemically and tested with the real-time PCR assay developed in this study. The PCR assay and the biochemical identification had 100% agreement on the tested isolates. The gadE real-time PCR assay was demonstrated in this study to be an inexpensive, reliable method for confirming E. coli colonies within 1.5 h from an agar plate, thereby saving on final identification time.

Probing a dielectric resonator acting as passive sensor through a wireless microwave link

Dielectric resonators, generally used for frequency filtering in oscillator loops, can be used as passive cooperative targets for wireless sensor applications. In the present work, we demonstrate such an approach by probing their spectral characteristics using a microwave RADAR system. The unique spectral response and energy storage capability of resonators provide unique responses allowing to separate the sensor response from clutter. Although the dielectric resonator is not designed for high temperature sensitivity, the accurate determination of the resonance frequency allows for a remote estimate of the temperature with Kelvin resolution.

Large-mode-area infrared guiding in ultrafast laser written waveguides in sulfur-based chalcogenide glasses

Current demands in astrophotonics impose advancing optical functions in infrared domains within embedded refractive index designs. We demonstrate concepts for large-mode-area guiding in ultrafast laser photowritten waveguides in bulk Sulfur-based chalcogenide glasses. If positive index contrasts are weak in As2S3, Ge doping increases the matrix rigidity and allows for high contrast (10(-3)) positive refractive index changes. Guiding with variable mode diameter and large-mode-area light transport is demonstrated up to 10 μm spectral domain using transverse slit-shaped and evanescently-coupled multicore traces.

Local oscillator phase noise limitation on the resolution of acoustic delay line wireless passive sensor measurement

The role of the phase noise of a local oscillator driving a pulsed-mode RADAR used for probing surface acoustic wave sensors is investigated. The echo delay, representative of the acoustic velocity, and hence the physical quantity probed by the sensor, is finely measured as a phase. Considering that the intrinsic oscillator phase fluctuation defines the phase noise measurement resolution, we experimentally and theoretically assess the relation between phase noise, measurement range, and measurand resolution.

[The pedicled temporal fascia flap for facial defect coverage]

INTRODUCTION

The fascia superficialis temporalis (FST) can be used as a pedicled flap. Its span allows covering important head and neck defects. We present our experience with four patients.

OBSERVATION

The FST flap, grafted with thin skin allowed covering: zygomatic defect after resection of Merkel cell carcinoma; the upper part of the right auricle after exeresis due to an arterial and venous malformation; the left orbital and palpebral region after exeresis of a basal cell carcinoma; the total auricle amputation site after exeresis of a squamous cell carcinoma. The cosmetic results were satisfactory in every case.

DISCUSSION

The thinness and the plasticity of the FST make it an excellent flap for facial reconstruction. Rapid surgery and low rate of sampling morbidity are assets for reconstruction in patients often fragile and old.

α,β-Acetylenic amino thiolester inhibitors of aldehyde dehydrogenases 1&3: suppressors of apoptogenic aldehyde oxidation and activators of apoptosis

The aim of this minireview is to recapitulate the evidence in the literature supporting a role for the aldehyde dehydrogenases (ALDH1, ALDH2 and ALDH3) in controlling the levels of 3 endogenous apoptogenic aldehydes: methional, malondialdehyde (MDA) and 4-hydroxynonenal (HNE). All 3 aldehydes are formed during the metabolism of cellular constituents. Methional is derived from the oxidative decarboxylation of 4-methylthio-2-oxobutanoate coming from the methionine salvage pathway. MDA arises from the peroxidation of lipids and also from methional subjected to attack by reactive oxygen species (ROS). HNE is formed primarily from lipid peroxidation by ROS attack. One major origin of ROS is the dysfunctional electron transport chain in the mitochondria of cancer cells. As bifunctional electrophilic compounds, HNE forms adducts with cellular nucleophiles e.g. GSH, whilst MDA acts as a potent DNA/protein cross-linking agent in vitro and in vivo. Cancer cells protect themselves from the apoptogenic effect of these aldehydes by the ALDHs that oxidize them to their non-apoptogenic carboxylic acids. Indeed, the over-expression of ALDH3 protects cells from HNE-induced apoptosis. The inhibition of ALDH1 allows methional to reach its apoptogenic threshold in BAF3bcl2 that were resistant to methional-inducible apoptosis. One member of the α,β-acetylenic N-substituted aminothiol ester family is an "active-enzyme-dependent", competitive, irreversible inhibitor of ALDH1 in vitro, an inhibitor of ALDH1 and ALDH3 in rat and human cancer cells in culture, an irreversible apoptogen on chemoresistant bcl2(+++) murine lymphoid and human epithelial cancer cells but a reversible cytostatic compound on human prostate epithelial normal cells in culture.