Evaluation of Listeria monocytogenes biofilms attachment and formation on different surfaces using a CDC biofilm reactor.

Listeria monocytogenes can adapt, persist, and form biofilms on food premises surfaces, representing a challenge for food safety, since they led to disease transmission, food contamination and spoilage during production. Physical interventions (scrubbing and wiping) can help controlling formation, nevertheless when biofilms are formed, they are usually very resistant to current control strategies used in the food industry. Biofilm attachment and formation is influenced by environment characteristics, substrate properties and microbial motility. The purpose of this study was to evaluate the ability of L. monocytogenes to attach and form biofilms on different surfaces (wood, nylon, and polycarbonate) representative of the materials used during produce harvesting and storage. Multi-strain L. monocytogenes biofilms were grown in a CDC Biofilm reactor at 20 ± 2 °C up to 96-h and characterized for: a) attachment strength by enumerating cells after rinsing; b) hydrophobicity and interfacial tension by contact angle measurements; c) biofilm architecture by Laser Scanning Confocal Microscopy. All experiments were done in triplicate. Material, incubation, and solvent significantly affected the hydrophobicity and wetting properties of L. monocytogenes biofilms (P < 0.05). The type of material and incubation time significantly influenced hydrophobicity and wetting properties of L. monocytogenes biofilms (P < 0.05). Highest contact angle and lowest interfacial tension were observed on polycarbonate coupons. The data presented contributes to understanding Listeria biofilms grow on different surfaces commonly used in produce harvesting and storage. The data obtained in this study can be used when evaluating intervention strategies to control this pathogen in food premises.

Feasibility study of a high spatial and time resolution beam emission spectroscopy diagnostic for localized density fluctuation measurements in Lithium Tokamak eXperiment-ß (LTX-ß).

Trapped electron mode (TEM) is the main source of turbulence predicted for the unique operation regime of a flat temperature profile under low-recycling conditions in the LTX-ß tokamak, while ion temperature gradient driven turbulence may also occur with gas fueling from the edge. To investigate mainly TEM scale density fluctuations, a high spatial and time resolution 2D beam emission spectroscopy (BES) diagnostic is being developed. Apart from spatially localized density turbulence measurement, BES can provide turbulence flow and flow shear dynamics. This BES system will be realized using an avalanche photodiode-based camera and narrow band interference filter. The system can acquire data at 2 MHz. Simulations with the Simulation of Spectra (SOS) code indicate that a high signal to noise ratio can be achieved with the proposed system. This will enable sampling the density fluctuations at this high time resolution. The design considerations and system optimization using the SOS code are presented.

Validation of the bag-mediated filtration system for environmental surveillance of poliovirus in Nairobi, Kenya.

AIMS: This study compared the bag-mediated filtration system (BMFS) and standard WHO two-phase separation methods for poliovirus (PV) environmental surveillance, examined factors impacting PV detection and monitored Sabin-like (SL) PV type 2 presence with withdrawal of oral polio vaccine type 2 (OPV2) in April 2016. METHODS AND RESULTS: Environmental samples were collected in Nairobi, Kenya (Sept 2015-Feb 2017), concentrated via BMFS and two-phase separation methods, then assayed using the WHO PV isolation algorithm and intratypic differentiation diagnostic screening kit. SL1, SL2 and SL3 were detected at higher rates in BMFS than two-phase samples (P < 0·05). In BMFS samples, SL PV detection did not significantly differ with volume filtered, filtration time or filter shipment time (P > 0·05), while SL3 was detected less frequently with higher shipment temperatures (P = 0·027). SL2 was detected more frequently before OPV2 withdrawal in BMFS and two-phase samples (P < 1 × 10-5 ). CONCLUSIONS: Poliovirus was detected at higher rates with the BMFS, a method that includes a secondary concentration step, than using the standard WHO two-phase method. SL2 disappearance from the environment was commensurate with OPV2 withdrawal. SIGNIFICANCE AND IMPACT OF THE STUDY: The BMFS offers comparable or improved PV detection under the conditions in this study, relative to the two-phase method.

A preliminary investigation of the contribution of different tenderness factors to beef loin, tri-tip and heel tenderness.

The objective of this study was to identify the relative contribution of tenderness factors for three beef muscles with similar tenderness ratings. Longissimus lumborum (LL), tensor fascia latae (TF) and gastrocnemius (GC) were collected from 10 USDA low Choice beef carcasses and assigned to a 5 or 21 days aging period (n = 60). Sarcomere length, troponin-T degradation, collagen content, mature collagen crosslink density, intramuscular lipid content and trained panel analysis were measured. Correlation and multivariate regression analysis indicated each muscle has a specific tenderness factor that contributed to the overall tenderness evaluated by trained panelists. The equations indicated LL tenderness was driven by lipid content (P < .05); TF tenderness was driven by collagen content (P < .05). GC tenderness was driven by proteolysis (P < .01), and only collagen content can be casually used as an overall tenderness predictor for all three cuts.

A simple vacuum suitcase for enabling plasma facing component characterization in fusion devices.

We have demonstrated a vacuum suitcase to transport samples in vacuo to a surface analysis station for characterization of tokamak plasma facing components (PFCs). This technique enables surface analysis at powerful, dedicated stations that are not encumbered by design constraints imposed on them by a tokamak. The vacuum suitcase is an alternative solution to characterizing PFCs using diagnostics that are designed and built around a tokamak. The vacuum suitcase, called the Sample Exposure Probe (SEP), features mobile ultra-high vacuum pumping. Active pumping under high vacuum enables sample transfer between the Lithium Tokamak eXperiment-ß (LTX-ß) and a high resolution X-ray Photoelectron Spectroscopy (XPS) system that is situated close by. A thermocouple inserted in the back of the sample head measures heat flux from the plasma during exposure, and together with a button heater, allows the sample to match the LTX-ß PFCs in high temperature operations. As vacuum conditions are better during transfer and analysis than in the tokamak, less contamination is introduced to the samples. XPS scans on a dedicated analysis station enable peak identification due to higher resolution and signal to noise ratio. A similar probe could be implemented for other fusion devices. The SEP is the first vacuum suitcase implementation for fusion applications that incorporates active pumping.

Correlation of serum protein biomarkers with disease activity in psoriatic arthritis.

Objective: To assess the correlation of serum protein biomarkers with disease activity across different domains of psoriatic arthritis (PsA).Material and methods: A cross-sectional cohort of 45 adult patients with PsA fulfilling the classification for psoriatic arthritis (CASPAR) criteria was recruited from University of California San Diego (UCSD) Arthritis Clinics. Clinical data and serum samples were collected and serum was analyzed for protein biomarkers hypothesized to be relevant to disease activity in PsA. Correlations were evaluated for clinical disease activity measures across disease domains.Results: Biomarkers with the highest correlation to the composite indices and disease domains were SAA, IL-6, YKL-40, and ICAM-1. In addition, several biomarkers were moderately correlated with individual composite indices and/or disease domains. Low or no correlation was observed with some biomarkers, e.g. MMP-3, MMP-1, EGF, VEGF, and IL-6R. In contrast, the correlation of all biomarkers with certain disease domains was low; specifically, pain, percent body surface area of psoriasis, and patient global assessment. The multi-biomarker disease activity score (MBDA) developed for rheumatoid arthritis (RA) showed high correlations with most composite indices and some disease domains in PsA.Conclusions: These data suggest biomarker analysis can reflect disease activity across disease domains in PsA. Certain domains would likely benefit from the evaluation of additional biomarkers.

Secondary colonic stent insertion in acute large bowel obstruction following primary stent failure.

INTRODUCTION: Colonic stent insertion has been shown to be an effective treatment for patients with acute large bowel obstruction, either as a bridge to surgery or as definitive treatment. However, little is known of the role of secondary stent insertion following primary stent failure in patients considered inappropriate or high risk for emergency surgery. METHODS: Fourteen patients presenting with acute large bowel obstruction who had previously been treated with colonic stent insertion were studied. All underwent attempted placement of a secondary stent. RESULTS: Technical deployment of the stent was accomplished in 12 patients (86%) but only 9 (64%) achieved clinical decompression. Successful deployment and clinical decompression of a secondary stent was associated with older age (p=0.038). Sex, pathology, site of obstruction, duration of efficacy of initial stent and cause of primary failure were unrelated to outcome. No procedure related morbidity or mortality was noted following repeated intervention. CONCLUSIONS: Secondary colonic stent insertion appears an effective, safe treatment in the majority of patients presenting with acute large bowel obstruction following failure of a primary stent.

Platelet thrombus formation in eHUS is prevented by anti-MBL2.

E. coli associated Hemolytic Uremic Syndrome (epidemic hemolytic uremic syndrome, eHUS) caused by Shiga toxin-producing bacteria is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury that cause acute renal failure in up to 65% of affected patients. We hypothesized that the mannose-binding lectin (MBL) pathway of complement activation plays an important role in human eHUS, as we previously demonstrated that injection of Shiga Toxin-2 (Stx-2) led to fibrin deposition in mouse glomeruli that was blocked by co-injection of the anti-MBL-2 antibody 3F8. However, the markers of platelet thrombosis in affected mouse glomeruli were not delineated. To investigate the effect of 3F8 on markers of platelet thrombosis, we used kidney sections from our mouse model (MBL-2+/+ Mbl-A/C-/-; MBL2 KI mouse). Mice in the control group received PBS, while mice in a second group received Stx-2, and those in a third group received 3F8 and Stx-2. Using double immunofluorescence (IF) followed by digital image analysis, kidney sections were stained for fibrin(ogen) and CD41 (marker for platelets), von-Willebrand factor (marker for endothelial cells and platelets), and podocin (marker for podocytes). Electron microscopy (EM) was performed on ultrathin sections from mice and human with HUS. Injection of Stx-2 resulted in an increase of both fibrin and platelets in glomeruli, while administration of 3F8 with Stx-2 reduced both platelet and fibrin to control levels. EM studies confirmed that CD41-positive objects observed by IF were platelets. The increases in platelet number and fibrin levels by injection of Stx-2 are consistent with the generation of platelet-fibrin thrombi that were prevented by 3F8.

The charge exchange recombination spectroscopy diagnostic on the upgraded Lithium Tokamak eXperiment (LTX-ß).

The Lithium Tokamak eXperiment has undergone an upgrade to LTX-ß, a major part of which is the addition of neutral beam injection (NBI). NBI has allowed for a new charge exchange recombination spectroscopy (CHERS) system to be installed in order to measure impurity concentrations, ion temperature, and toroidal velocity. Previously on LTX measuring these parameters relied on passive spectroscopy and inversion techniques and had large uncertainty. The CHERS system has 52 total views, split into four groups of 13, half facing toward the beam and half symmetrically facing away from the beam, so the background non-beam related emission can be simultaneously subtracted. Both sets of views sample a major radius of 27-59 cm, with resolution through the beam of 1.5-2.5 cm. LTX-ß is expected to have its magnetic axis near 35 cm, with minor radii of 18-23 cm. Three separate spectrometers will be used for the diagnostic, giving the system great flexibility to simultaneously measure emission from multiple impurity lines. The viewing optics are f/1.8, allowing all of the spectrometers to be fully illuminated. Design and calibration of the system as well as the advantages of various configurations of the spectrometers will be highlighted.

Magnetic perturbation diagnostics in the high-temperature lithiated environment of LTX-ß.

Magnetic perturbation measurements will be invaluable for characterizing Lithium Tokamak Experiment Beta (LTX-ß) plasmas due to the time-evolving 3D nature of the magnetic fields generated by eddy currents in the vessel and copper shell segments, as well as enhanced MHD instability drive due to newly introduced neutral beam heating. The LTX-ß upgrade includes two new arrays of Mirnov coils: a shell eddy sensor array of two-axis coils distributed over the back surface of one shell segment and a toroidal array of poloidal field coils at the low-field side midplane gap. Evaporative lithium wall-coating and the high temperatures required for liquid lithium wall operation both complicate the implementation of in-vessel diagnostics. While the shell array is protected from lithium exposure, the shell segment to which it is mounted will at times exceed 300 °C. The toroidal array, however, will experience direct line-of-sight exposure to the lithium evaporator as well as close proximity to the hot shell and may also be subject to poorly confined beam-driven fast ions. We describe how the two new Mirnov coil arrays meet these environmental challenges and enhance the LTX-ß diagnostic suite.

Millimeter-wave interferometry and far-forward scattering for density fluctuation measurements on LTX-ß.

The λ ≈ 1 mm (f = 288 GHz) interferometer for the Lithium Tokamak Experiment-ß (LTX-ß) will use a chirped-frequency source and a centerstack-mounted retro-reflector mirror to provide electron line density measurements along a single radial chord at the midplane. The interferometer is unique in the use of a single source (narrow-band chirped-frequency interferometry) and a single beam splitter for separating and recombining the probe and reference beams. The current work provides a documentation of the interferometry hardware and evaluates the capabilities of the system as a far-forward collective scattering diagnostic. As such, the current optical setup is estimated to have a detection range of 0.4 ≲ k ⊥ ≲ 1.7 cm-1, while an improved layout will extend the upper k ⊥ limit to ∼3 cm-1. Measurements with the diagnostic on LTX are presented, showing interferometry results and scattered signal data. These diagnostics are expected to provide routine measurements on LTX-ß for high frequency coherent density oscillations (e.g., Alfvénic modes during neutral beam injection) as well as for broadband turbulence.

Investigating the relationship between noise transfer inside the x-ray framing cameras and their imaging ability.

We apply a cascaded linear model analysis to a micro-channel plate x-ray framing camera. We establish a theoretical expression of the Noise Power Spectrum (NPS) at the detector's output and assess its accuracy by comparing it to the NPS of Monte Carlo simulations of the detector's response to a uniform illumination. We also demonstrate that fitting the NPS of experimental data against a parametric model based on this expression can yield valuable information on the imaging ability of framing cameras, offering an alternative approach to the usual method employed to measure their modulation transfer functions.

Physical Activity, Fatigue, and Sleep in People with Parkinson's Disease: A Secondary per Protocol Analysis from an Intervention Trial.

Symptoms of Parkinson's can result in low physical activity and poor sleep patterns which can have a detrimental effect on a person's quality of life. To date, studies looking into exercise interventions for people with Parkinson's (PwP) for symptom management are promising but inconclusive. The aim of this study is to estimate the effect of a clearly defined exercise prescription on general physical activity levels, fatigue, sleep, and quality of life in PwP. Method. PwP randomised into either an exercise group (29; 16 males, 13 females; mean age 67 years (7.12)) or a control handwriting group (36; 19 males; 17 females; mean age 67 years (5.88)) as part of a larger trial were included in this substudy if they had completed a 6-month weekly exercise programme (intervention group) and had complete objective physical activity data (intervention and control group). Sleep and fatigue were recorded from self-reported measures, and physical activity levels measured through the use of accelerometers worn 24 hours/day over a seven-day testing period at baseline and following the 24-week intervention. A Wilcoxon's test followed by a Mann-Whitney post hoc analysis was used, and effect sizes were calculated. Results. Participants showed a significant increase in time spent in sedentary and light activities during the overnight period postintervention in both exercise and handwriting groups (p < 0.05) with a moderate effect found for the change in sedentary and light activities in the overnight hours for both groups, over time (0.32 and 0.37-0.38, resp.). There was no impact on self-reported fatigue or sleep. Conclusion. The observed moderate effect on sedentary and light activities overnight could suggest an objective improvement in sleep patterns for individuals participating in both exercise and handwriting interventions. This supports the need for further studies to investigate the role of behavioural interventions for nonmotor symptoms.

Decreased photosynthetic rate under high temperature in wheat is due to lipid desaturation, oxidation, acylation, and damage of organelles.

BACKGROUND: High temperature is a major abiotic stress that limits wheat (Triticum aestivum L.) productivity. Variation in levels of a wide range of lipids, including stress-related molecular species, oxidative damage, cellular organization and ultrastructural changes were analyzed to provide an integrated view of the factors that underlie decreased photosynthetic rate under high temperature stress. Wheat plants of cultivar Chinese Spring were grown at optimum temperatures (25/15 °C, maximum/minimum) until the onset of the booting stage. Thereafter, plants were exposed to high temperature (35/25 °C) for 16 d. RESULTS: Compared with optimum temperature, a lower photosynthetic rate was observed at high temperature which is an interplay between thylakoid membrane damage, thylakoid membrane lipid composition, oxidative damage of cell organelle, and stomatal and non-stomatal limitations. Triacylglycerol levels were higher under high temperature stress. Polar lipid fatty acyl unsaturation was lower at high temperature, while triacylglycerol unsaturation was the same at high temperature and optimum temperature. The changes in lipid species indicates increases in activities of desaturating, oxidizing, glycosylating and acylating enzymes under high temperature stress. Cumulative effect of high temperature stress led to generation of reactive oxygen species, cell organelle and membrane damage, and reduced antioxidant enzyme activity, and imbalance between reactive oxygen species and antioxidant defense system. CONCLUSIONS: Taken together with recent findings demonstrating that reactive oxygen species are formed from and are removed by thylakoid lipids, the data suggest that reactive oxygen species production, reactive oxygen species removal, and changes in lipid metabolism contribute to decreased photosynthetic rate under high temperature stress.

Which attributes within target product profiles for tuberculosis diagnostics are the most important to focus on?

SETTING: New diagnostic tools for tuberculosis (TB) are urgently needed. To guide investment decisions, sufficient information regarding which test attributes are the most important for users and decision makers interested in introducing TB diagnostics should be made available. OBJECTIVE: To rank test attributes in a target product profile (TPP) in order of importance for a sputum smear replacement test for TB. DESIGN: An online survey was administered among 33 participants representing 14 of the 22 TB high-burden countries. Respondents included laboratory personnel, national TB program managers, donors, technical experts, patients and researchers. Participants were asked to rank 21 TPP test attributes in order of importance using a maximum-differential method that required ranking of relative trade-offs. RESULTS: Sensitivity was ranked as the most important test attribute, followed by maintenance/calibration, reagent kit storage/stability, sample preparation steps and time to results. CONCLUSION: Consulting widely regarding which TPP attributes are valued most by users and decision-makers involved in introducing TB diagnostics can assist TB test developers to prioritize their investments, and guide decision making if trade-offs are necessary.

Observation of Flat Electron Temperature Profiles in the Lithium Tokamak Experiment.

It has been predicted for over a decade that low-recycling plasma-facing components in fusion devices would allow high edge temperatures and flat or nearly flat temperature profiles. In recent experiments with lithium wall coatings in the Lithium Tokamak Experiment (LTX), a hot edge (>200 eV) and flat electron temperature profiles have been measured following the termination of external fueling. Reduced recycling was demonstrated by retention of ∼60% of the injected hydrogen in the walls following the discharge. Electron energy confinement followed typical Ohmic confinement scaling during fueling, but did not decrease with density after fueling terminated, ultimately exceeding the scaling by ∼200%. Achievement of the low-recycling, hot edge regime has been an important goal of LTX and lithium plasma-facing component research in general, as it has potentially significant implications for the operation, design, and cost of fusion devices.

A frequency-modulated continuous-wave reflectometer for the Lithium Tokamak Experiment.

The frequency-modulated continuous-wave reflectometer on LTX (Lithium Tokamak Experiment) and the data analysis methods used for determining electron density profiles are described. The diagnostic uses a frequency range of 13.1-33.5 GHz, for covering a density range of 0.21-1.4×1013 cm-3 (in O-mode polarization) with a time resolution down to 8 µs. The design of the diagnostic incorporates the concept of an "optimized" source frequency sweep, which minimizes the large variation in the intermediate frequency signal due to a long dispersive transmission line. The quality of the raw data is dictated by the tuning characteristics of the microwave sources, as well as the group delay ripple in the transmission lines, which can generate higher-order nonlinearities in the frequency sweep. Both effects are evaluated for our diagnostic and best practices are presented for minimizing "artifacts" generated in the signals. The quality of the reconstructed profiles is also improved using two additional data analysis methods. First, the reflectometer data are processed as a radar image, where clutter due to echoes from the wall and backscattering from density fluctuations can be easily identified and removed. Second, a weighed least-squares lamination algorithm POLAN (POLynomial ANalysis) is used to reconstruct the electron density profile. Examples of density profiles in LTX are presented, along with comparisons to measurements from the Thomson scattering and the λ = 1 mm interferometer diagnostics.

Acoustic power delivery to pipeline monitoring wireless sensors.

The use of energy harvesting for powering wireless sensors is made more challenging in most applications by the requirement for customization to each specific application environment because of specificities of the available energy form, such as precise location, direction and motion frequency, as well as the temporal variation and unpredictability of the energy source. Wireless power transfer from dedicated sources can overcome these difficulties, and in this work, the use of targeted ultrasonic power transfer as a possible method for remote powering of sensor nodes is investigated. A powering system for pipeline monitoring sensors is described and studied experimentally, with a pair of identical, non-inertial piezoelectric transducers used at the transmitter and receiver. Power transmission of 18mW (Root-Mean-Square) through 1m of a118mm diameter cast iron pipe, with 8mm wall thickness is demonstrated. By analysis of the delay between transmission and reception, including reflections from the pipeline edges, a transmission speed of 1000m/s is observed, corresponding to the phase velocity of the L(0,1) axial and F(1,1) radial modes of the pipe structure. A reduction of power delivery with water-filling is observed, yet over 4mW of delivered power through a fully-filled pipe is demonstrated. The transmitted power and voltage levels exceed the requirements for efficient power management, including rectification at cold-starting conditions, and for the operation of low-power sensor nodes. The proposed powering technique may allow the implementation of energy autonomous wireless sensor systems for monitoring industrial and network pipeline infrastructure.