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Behavior is characterized by sequences of goal oriented conducts, such as food uptake, socializing and resting. Classically, one would define for each task a corresponding satisfaction level, with the agent engaging, at a given time, in the activity having the lowest satisfaction level. Alternatively, one may consider that the agent follows the overarching objective to generate sequences of distinct activities. To achieve a balanced distribution of activities would then be the primary goal, and not to master a specific task. In this setting the agent would show two types of behaviors, task-oriented and task-searching phases, with the latter interseeding the former. We study the emergence of autonomous task switching for the case of a simulated robot arm. Grasping one of several moving objects corresponds in this setting to a specific activity. Overall, the arm should follow a given object temporarily and then move away, in order to search for a new target and reengage. We show that this behavior can be generated robustly when modeling the arm as an adaptive dynamical system. The dissipation function is in this approach time dependent. The arm is in a dissipative state when searching for a nearby object, dissipating energy on approach. Once close, the dissipation function starts to increase, with the eventual sign change implying that the arm will take up energy and wander off. The resulting explorative state ends when the dissipation function becomes again negative and the arm selects a new target. We believe that our approach may be generalized to generate self-organized sequences of activities in general. [ABSTRACT FROM AUTHOR]

The multiple-breath washout (MBW) is a lung function test that measures the degree of ventilation inhomogeneity (VI). The test is used to identify small airway impairment in patients with lung diseases like cystic fibrosis. However, the physical and physiological factors that influence the test outcomes and differentiate health from disease are not well understood. Computational models have been used to better understand the interaction between anatomical structure and physiological properties of the lung, but none of them has dealt in depth with the tracer gas washout test in a whole. Thus, our aim was to create a lung model that simulates the entire MBW and investigate the role of lung morphology and tissue mechanics on the tracer gas washout procedure. To this end, we developed a multi-scale lung model to simulate the inert gas transport in airways of all size. We then applied systematically different modifications to geometrical and mechanical properties of the lung model (compliance, residual airway volume and flow resistance) which have been associated with VI. The modifications were applied to distinct parts of the model, and their effects on the gas distribution within the lung and on the gas concentration profile were assessed. We found that variability in compliance and residual volume of the airways, as well as the spatial distribution of this variability in the lung had a direct influence on gas distribution among airways and on the MBW pattern (washout duration, characteristic concentration profile during each expiration), while the effects of variable flow resistance were negligible. Based on these findings, it is possible to classify different types of inhomogeneities in the lung and relate them to specific features of the MBW pattern, which builds the basis for a more detailed association of lung function and structure. [ABSTRACT FROM AUTHOR]

Biophysical and biochemical data on hyaluronan (HA)-based dermal fillers strongly support their optimal use and design to meet specific requisites. Here, four commercially available (in Europe) HA “volumetric” fillers, among the most used in the clinical practice, have been characterized in vitro. Analyses revealed the highest amounts of water-soluble HA reported so far and provided hydrodynamic data for these soluble polymeric fractions. Volumetric gels exhibit a wide range of rigidity with most of them showing G’ values around 200-300Pa. They greatly differ in cohesivity. 1mL of gel hydrates up to 2.4–3.2mL. The products completely solubilize due to Bovine Testicular Hyaluronidase (BTH)’s action, thus predicting in vivo complete resorption. For the first time, filler degradation due to reactive oxygen species (ROS) was studied by rheological measurements and a rank in stability was established. Studies using Human Dermal Fibroblasts (HDF) indicated a positive biological response to the HA networks. Further, gel capacity to prompt collagen I, elastin and aquaporin3 synthesis was demonstrated, thus suggesting a positive effect on skin elasticity and hydration, besides the physical volumetric action. The findings are the first wide assessment of features for the volumetric class of HA-fillers and include first data on their resistance to degradation by ROS and biological effects on HDF. The study represents a valuable contribution to the understanding of HA-fillers, useful to optimize their use and manufacture. [ABSTRACT FROM AUTHOR]

To evaluate the effectiveness of high-flow nasal humidified oxygen (HFNHO) therapy in patients with mild hypoxemia after extubation. This study included 316 patients with mild hypoxemia after extubation from May 2016 to May 2018 from two intensive care units in China. Compare the effects of the Venturi Mask and High-Flow Nasal Humidified Oxygen (HFNHO) therapy on Heart Rate (HR), Respiratory Rate (RR), Oxygen Saturation (SpO2), Oxygen Partial Pressure (PO2), Partial Pressure Of Carbon Dioxide (PCO2), Oxygenation Index (PO2/FiO2) after extubation, the use of noninvasive mechanical ventilation and tracheal intubation after treatment failure were observed and recorded. Patients have both lower HR and RR than those who received mask treatment (75.4±18.5 vs. 83.0±20.4, p = 0.0004; 18±6.5 vs. 23.6±10.3, p<0.001, respectively). There was significant difference between those who had HFNHO and mask administration's SpO2 and PO2 (94.1±6.4 vs. 87.5±1.5, p<0.001; 88.16±2.9 vs. 77.3±2.3, p<0.001, respectively). For the HFNHO group, patients had lower PCO2 with the mask group. (41.3±0.99 vs 42.2±1.2, p<0.001). On the other hand, the levels of PO2/FiO2 was significantly higher in the HFNHO Group, (181.0±8.3 vs. 157.2±4.9, p<0.05). We concluded HFNHO therapy could significantly relieve the symptoms of dyspnea, improve oxygenation, reduce the use of noninvasive mechanical ventilation and reduce the rate of secondary tracheal intubation in patients with mild hypoxemia after extubation. [ABSTRACT FROM AUTHOR]

Protein-protein interactions are central to biological processes. In vitro methods to examine protein-protein interactions are generally categorized into two classes: in-solution and surface-based methods. Here, using the multivalent interactions between nucleocytoplasmic transport factors and intrinsically disordered FG repeat containing nuclear pore complex proteins as a model system, we examined the utility of three surface-based methods: atomic force microscopy, quartz crystal microbalance with dissipation, and surface plasmon resonance. Although results were comparable to those of previous reports, the apparent effect of mass transport limitations was demonstrated. Additional experiments with a loss-of-interaction FG repeat mutant variant demonstrated that the binding events that take place on surfaces can be unexpectedly complex, suggesting particular care must be exercised in interpretation of such data. [ABSTRACT FROM AUTHOR]

Pharmacological efficacy is based on the drug concentration in target tissues, which usually cannot be represented by the plasma concentration. The purpose of this study was to compare the pharmacokinetic characteristics of gemifloxacin in plasma and skeletal muscle and evaluate its tissue penetration in both healthy and MRSA (methicillin-resistant Staphylococcus aureus)-infected rats. A microdialysis (MD) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine free gemifloxacin concentrations in rat plasma and skeletal muscle simultaneously. The in vivo recoveries of MD were 23.21% ± 3.42% for skeletal muscle and 20.62% ± 3.19% for plasma, and were concentration independent. We provided evidence that the method developed here meets FDA requirements. Additionally, this method was successfully applied to the determination of free gemifloxacin in rats. Muscle and blood dialysates were collected after an 18 mg/kg intravenous bolus dose. The mean areas under the concentration-time curves (AUCs) from 0 to 9 h for skeletal muscle and plasma were 3641.50 ± 915.65 h*ng/mL and 7068.32 ± 1964.19 h*ng/mL in MRSA-infected rats and 3774.72 ± 700.36 h*ng/mL and 6927.49 ± 1714.86 h*ng/mL in healthy rats, respectively. There was no significant difference (P>0.05) in gemifloxacin exposure between healthy rats and MRSA-infected rats for plasma or muscle. The low ratio of AUC0-9 muscle to AUC0-9 plasma suggested lower drug exposure in skeletal muscle than in plasma for both healthy and MRSA-infected rats. Our study suggested that the administration of gemifloxacin according to drug levels in plasma to treat local infection is unreasonable and might result in an inadequate dose regimen. [ABSTRACT FROM AUTHOR]

Among neurodegenerative diseases, Alzheimer’s disease (AD) is one of the most grievous disease. The oldest cholinergic hypothesis is used to elevate the level of cognitive impairment and acetylcholinesterase (AChE) comprises the major targeted enzyme in AD. Thus, acetylcholinesterase inhibitors (AChEI) constitutes the essential remedy for the treatment of AD. The study aims to evaluate the interactions between natural molecules and AChE by Surface Plasmon Resonance (SPR). The molecules like alkaloids, polyphenols and substrates of AChE have been considered for the study with a major emphasis on affinity and kinetics. To better understand the activity of small molecules, the investigation is supported by both experimental and theoretical approach such as fluorescence, Circular Dichroism (CD) and molecular docking studies. Amongst the screened ones tannic acid showed promising results compared with others. The methodology followed here have highlighted many molecules with a higher affinity towards AChE and these findings may take lead molecules generated in preclinical studies to treat neurodegenerative diseases. Additionally, we suggest a unique signature for the heterogeneous analyte model using competitive experiments for analyzing simultanous interactions of both the analytes. [ABSTRACT FROM AUTHOR]

Conventional geometric design methods for pre-signal systems usually use the expected traffic demand, which may obtain a short sorting area distance and lead to frequent queue spillbacks due to stochastic traffic arrivals. On the other hand, if one selects a longer sorting area distance, the geometric design will suffer from low spatial utilization with higher delay and lower capacity. In this paper, we propose a geometric design method for intersections with pre-signal systems using a phase swap strategy. The geometric design can balance the desire of storing more vehicles to prevent spillbacks and improve the spatial utilization of the road. We model the traffic dynamic within the pre-signal system using queue theory and shockwave theory to determine the furthest point a queue can reach. The length of the pre-signal system should be short enough to improve spatial utilization but longer than the furthest point of the queue to prevent queue spillback. The effectiveness of the pre-signal system is evaluated by the VISSIM Signal Control Application Programming Interfaces (SCAPI). The results indicate that the proposed design plan increases the spatial utilization of the pre-signal system by 7.5% while maintaining a similar delay, queue length and ratio of flow to saturation flow. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study was to evaluate the feasibility of intraosseous (i.o.) contrast media injection (CMI) for emergency computed tomography (CT) of severe trauma and the associated image quality compared to intravenous (i.v.) CMI. Materials and methods: The authors retrospectively analysed objective (contrast-to-noise ratio (CNR)) and subjective (4-point Likert scale) image quality of CTs after i.o. (n = 4, mean age (y) 57.0±11.0) versus i.v. (n = 20, mean age (y) 58.8±4.4) CMI. All patients underwent a native head CT scan, a cerebral CT angiography (CTA) and CTA of the supra-aortic vasculature as well as a chest and abdominal CT scan in the venous phase; one patient with an i.o. access additionally received a CTA of the lower limbs. Electronic patient records have been reviewed to determine i.o. access related complications. Results: Both groups were consistent in age, heart rate, scan parameters including the flow rate of the contrast agent, resulting in comparable radiation dose levels. The image noise and CNR had no significant difference between the two groups. Scoring the delineation of the main vessels after i.o. CMI showed no significant difference to the i.v. group. There were no CT or i.o. access related complications observed. Conclusion: The i.o. access is a safe and suitable alternative for emergency CMI in CT. Using established protocols good to very good image quality can be achieved, comparable to i.v. CMI. We show for the first time, that i.o. CMI is also feasible for CTA imaging of the head and neck region as well as of pelvic and leg vessels. [ABSTRACT FROM AUTHOR]

The relatively rapid inhibition of microplasmin by α2-AP leads to short functional half-life of the molecule in vivo, causing inefficient clot dissolution, even after site-specific, local catheter-based delivery. Here, we describe a PEGylation approach for improving the therapeutic potential via improving the survival of microplasmin in presence of its cognate inhibitor, α2-AP, wherein a series of strategically designed cysteine analogs of micro-plasminogen were prepared and expressed in E. coli, and further modified by covalent grafting in vitro with PEG groups of different molecular sizes so as to select single or double PEG chains that increase the molecular weight and hydrodynamic radii of the conjugates, but with a minimal discernible effect on intrinsic plasmin activity and structural framework, as explored by amidolytic activity and CD-spectroscopy, respectively. Interestingly, some of the purified PEG-coupled proteins after conversion to their corresponding proteolytically active forms were found to exhibit significantly reduced inhibition rates (up to 2-fold) by α2-AP relative to that observed with wild-type microplasmin. These results indicate an interesting, and not often observed, effect of PEG groups through reduced/altered dynamics between protease and inhibitor, likely through a steric hindrance mechanism. Thus, the present study successfully identifies single- and double-site PEGylated muteins of microplasmin with significantly enhanced functional half-life through enhanced resistance to inactivation by its in vivo plasma inhibitor. Such an increased survival of bioactivity in situ, holds unmistakable potential for therapeutic exploitation, especially in ischemic strokes where a direct, catheter-based deposition within the cranium has been shown to be promising, but is currently limited by the very short in vivo bioactive half-life of the fibrin dissolving agent/s. [ABSTRACT FROM AUTHOR]

Coffee farms have been adopting the microterraces system, a technique that reduces the effect of the slope by moving the soil between the crop lines. In this way, all the mechanized operations can be carried out normally, except for harvesting, due to the work limitation of the harvesters, who work in areas with a maximum slope of 20%. One option is to use unilateral harvesters, which crop one side at a time; however, there has been no research on these microterrace machines to evaluate their performance and to compare it with those of the other harvesting methods in those regions. This study aimed to compare the mechanized harvest performance in the microterraces with the manual and semimechanized harvesting methods. The study was carried out in an agricultural area of the municipality of Ouro Fino / MG, Brazil, in a crop production site where the microterraces were built six years before the experiment. The treatments were assigned to a split-block design with seven repetitions and consisted of mechanized harvest—unilateral harvester with bag storage; manual harvest—regionally experienced workers; and semimechanized harvest—with portable breakers. Through an analysis of the times and movements, the operational efficiency and operational and effective field capabilities were measured. The adoption of microterraces allows the efficient mechanization of areas previously impossible to mechanize. The unilateral harvester is a potential tool for the partial replacement of manual labor in the harvest, performing a service equivalent to that of 23.68 manual workers and 10.55 manual workers in the semimechanized system. [ABSTRACT FROM AUTHOR]

A theory for turbulent particle pair diffusion in the inertial subrange [Malik NA, PLoS ONE 13(10):e0202940 (2018)] is investigated numerically using a Lagrangian diffusion model, Kinematic Simulations [Kraichnan RH, Phys. Fluids 13:22 (1970); Malik NA, PLoS ONE 12(12):e0189917 (2017)]. All predictions of the theory are observed in flow fields with generalised energy spectra of the type, E(k) ∼ k− p. Most importantly, two non-Richardson regimes are observed: for short inertial subrange of size 102 the simulations yield quasi-local regimes for the pair diffusion coefficient, ; and for asymptotically infinite inertial subrange the simulations yield non-local regimes , with γ intermediate between the purely local scaling γl = (1 + p)/2 and the purely non-local scaling γnl = 2. For intermittent turbulence spectra, E(k) ∼ k−1.72, the simulations yield , in agreement with the revised 1926 dataset [Richardson LF, Proc. Roy. Soc. Lond. A 100:709 (1926); Malik NA, PLoS ONE 13(10):e0202940 (2018)]. These results lend support to the physical picture proposed in the new theory that turbulent diffusion in the inertial subrange is governed by both local and non-local diffusion transport processes. [ABSTRACT FROM AUTHOR]

Background: Image-based blood flow simulations have been increasingly applied to investigate intracranial aneurysm (IA) hemodynamics. However, the acceptance among physicians remains limited due to the high variability in the underlying assumptions and quality of results. Methods: To evaluate the vessel segmentation as one of the most important sources of error, the international Multiple Aneurysms AnaTomy CHallenge 2018 (MATCH) was announced. 26 research groups from 13 different countries segmented three datasets, which contained five IAs in total. Based on these segmentations, 73 time-dependent blood flow simulations under consistent conditions were carried out. Afterwards, relevant flow and shear parameters (e.g., neck inflow rate, parent vessel flow rate, spatial mean velocity, and wall shear stress) were analyzed both qualitatively and quantitatively. Results: Regarding the entire vasculature, the variability of the segmented vessel radius is 0.13 mm, consistent and independent of the local vessel radius. However, the centerline velocity shows increased variability in more distal vessels. Focusing on the aneurysms, clear differences in morphological and hemodynamic parameters were observed. The quantification of the segmentation-induced variability showed approximately a 14% difference among the groups for the parent vessel flow rate. Regarding the mean aneurysmal velocity and the neck inflow rate, a variation of 30% and 46% was observed, respectively. Finally, time-averaged wall shear stresses varied between 28% and 51%, depending on the aneurysm in question. Conclusions: MATCH reveals the effect of state-of-the-art segmentation algorithms on subsequent hemodynamic simulations for IA research. The observed variations may lead to an inappropriate interpretation of the simulation results and thus, can lead to inappropriate conclusions by physicians. Therefore, accurate segmentation of the region of interest is necessary to obtain reliable and clinically helpful flow information. [ABSTRACT FROM AUTHOR]

The zero-speed fin stabilizer is used to stabilize the roll motion of the ship at full speed. It has two working modes, that is the lift-based normal anti-rolling mode and the drag-based zero-speed anti-rolling mode. Different force generation mechanisms cause different control methods, especially in the form of control. The zero-speed fin stabilizer works in a sinusoidal fashion in normal mode, the same as the conventional fin stabilizer. However, its control form at zero speed is not particularly clear. This paper aims to investigate the control form of fin stabilizer at zero speed through a composite method of theoretical analysis and experimental research. Based on the established reaction force model, the forces generated on the fin flapped in sinusoidal and trapezoidal forms are compared and analyzed. It is found that the trapezoidal form flapping with a small half-cycle ratio generates larger force than the sinusoidal flapping form when the flapping amplitude is the same. The forced rolling tank tests with the fins flapping in sinusoidal and trapezoidal forms were conducted. The test results are consistent with the theoretical analysis results, and the trapezoidal flapping form with a proper small half-cycle ratio is recommended for fin stabilizers at zero speed. The control strategy of fin stabilizer at zero speed is obtained based on the further analysis of the force characteristics of the trapezoidal flapping form and the limitations of the actual fin stabilizer actuation system. The model and full scale roll reduction tests at zero speed were conducted, achieving more than 70% and 60% of the anti-rolling effect respectively. The test results further verify the effectiveness, applicability and practicability of the obtained control form and strategy for fin stabilizers in at-anchor conditions, and can be a reference for engineering practice and other similar studies. [ABSTRACT FROM AUTHOR]

Understanding changes in wave attenuation by emergent vegetation as wetlands degrade or accrete over time is crucial for incorporation of wetlands into holistic coastal risk management. Linked SLAMM and XBeach models were used to investigate potential future changes in wave attenuation over a 50-year period in a degrading, subtropical wetland and a prograding, temperate wetland. These contrasting systems also have differing management contexts and were contrasted to demonstrate how the linked models can provide management-relevant insights. Morphological development of wetlands for different scenarios of sea-level rise and accretion was simulated with SLAMM and then coupled with different vegetation characteristics to predict the influence on future wave attenuation using XBeach. The geomorphological context, subsidence, and accretion resulted in large predicted reductions in the extent of vegetated land (e.g., wetland) and changes in wave height reduction potential across the wetland. These were exacerbated by increases in sea-level from +0.217 m to +0.386 m over a 50-year period, especially at the lowest accretion rates in the degrading wetland. Mangrove vegetation increased wave attenuation within the degrading, subtropical, saline wetland, while grazing reduced wave attenuation in the temperate, prograding wetland. Coastal management decisions and actions, related to coastal vegetation type and structure, have the potential to change future wave attenuation at a spatial scale relevant to coastal protection planning. Therefore, a coastal management approach that includes disaster risk reduction, biodiversity, and climate change, can be informed by coastal modeling tools, such as those demonstrated here for two contrasting case studies. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the impact of soft contact lens eye-fit on optical power by computational modelling and to produce correction maps for reversing this impact during the design process. Methods: Finite element models of spherical and toric hydrogel contact lenses at varying nominal powers of -20 D to +20 D, base curves radii (R1b) of 8.2, 8.5, 8.8 mm, and overall diameters (d3) of 14.5, 15.0, 15.5 mm were generated. Lenses were fitted to computational eye models generated with human eyes’ topography data. Combined eye-lens simulations were run under the boundary conditions of the tears’ surface tension between the contact lens and the eye in addition to the eyelid blink pressure. Lens optical zone power changes were calculated through computational light-ray tracing methods following each simulation. Results: Effective power changes (EPC) were affected negatively for all toric simulated lenses with power varying from -20 D to +20 D. Spherical lenses demonstrated similar behaviour, however with some positive EPC over the power range from -20 D to -10 D for spherical power (SPH) lenses. EPC assessment was between +0.25 D and -0.5 D for most lenses, however, lenses with prescriptions from +10 D to +20 D incurred EPC outside this range. The spherical lenses showed a maximum effective power change of +1.046 ± 0.338 D (Average Eye), and a minimum of -3.278 ± 0.731 D (Steep Eye). Similarly, the toric lenses showed a maximum of +1.501 ± 0.338 D (Average Eye), and a minimum of -3.514 ± 0.731 D (Steep Eye). EPC trends, along with minimum and maximum power, generally increased negatively as nominal lens prescription increased positively. Contact lens base curve selection affected the assessed effective power change for both spherical and toric lenses. The effect from lens total diameter for spherical lenses was less substantial than that for toric lenses. Conclusions: This study considered the impact of soft contact lens design parameters on effective optical power changes (EPC) after eye-fit. Spherical lenses experienced more EPC of clinical significance (>0.25 D) than toric lenses. Both types of lenses, spherical and toric (simple astigmatism), demonstrated similar trends in EPC on fitting from -20 D to +20 D, with lenses in the extremely positive and the extremely negative prescriptions demonstrating the highest EPCs. The lens base curve impacted the extent of EPC observed, with flatter base curves experiencing less power change. Diameter proved to impact toric lenses more than spherical ones, however generally the diameter has less effect on power change than base curve selection. [ABSTRACT FROM AUTHOR]

Humans exert a great deal of control over our local environments–selecting and arranging the many objects around us on the basis of conflicting task-demands, aesthetic preferences, and habitual convenience. Because routine behaviour necessitates that we regularly find and access these objects, the particular arrangements we choose can influence the likelihood and difficulty of engaging in different tasks and actions. Despite this importance, relatively little research has directly examined human organizational behaviours and tendencies. Here we investigate how objects in a computer-based search task are freely and dynamically arranged by participants over time, while manipulating the statistics of the target sequence. We report common organizational behaviours including reduction of distance between targets as well as separation of target subsets with high community. However, the extent of these behaviours and their relationship to individual differences in performance varies as a function of the target sequence structure. In particular, tasks composed of a larger number of smaller groups of targets lead to better organizational and performance outcomes than tasks composed of fewer larger groups. [ABSTRACT FROM AUTHOR]

Biological and bioinspired polymer microparticles have broad biomedical and industrial applications, including drug delivery, tissue engineering, surface modification, environmental remediation, imaging, and sensing. Full realization of the potential of biopolymer microparticles will require methods for rigorous characterization of particle sizes, morphologies, and dynamics, so that researchers may correlate particle characteristics with synthesis methods and desired functions. Toward this end, we evaluated biopolymer microparticles using flow imaging microscopy. This technology is widely used in the biopharmaceutical industry but is not yet well-known among the materials community. Our polymer, a genetically engineered elastin-like polypeptide (ELP), self-assembles into micron-scale coacervates. We performed flow imaging of ELP coacervates using two different instruments, one with a lower size limit of approximately 2 microns, the other with a lower size limit of approximately 300 nanometers. We validated flow imaging results by comparison with dynamic light scattering and atomic force microscopy analyses. We explored the effects of various solvent conditions on ELP coacervate size, morphology, and behavior, such as the dispersion of single particles versus aggregates. We found that flow imaging is a superior tool for rapid and thorough particle analysis of ELP coacervates in solution. We anticipate that researchers studying many types of microscale protein or polymer assemblies will be interested in flow imaging as a tool for quantitative, solution-based characterization. [ABSTRACT FROM AUTHOR]

In this paper, we present a method to estimate the market parameters modelled by an asymmetric jump diffusion process. The method proposed is based on Kou’s jump diffusion model while the market parameters refer to the market drift, the market volatility, the jump intensity on market price, and the rate of jump occurrence in a consistent manner throughout the entire paper. The model captures the asymmetric nature of the price fluctuation during up trend markets and down trend markets. The results are compared to conventional options to observe the impact of jump effects. The results from simulation show that the asymmetric jump diffusion model can estimate the fair prices of European call options and annuity better than the Black-Scholes model and the symmetric jump diffusion model proposed by Kou and Merton. [ABSTRACT FROM AUTHOR]

Introduction: Glucosamine dietary supplements are commonly used for the management of osteoarthritis (OA). However, clinical trials have reported varying outcomes with regard to joint function and disease progression. One of the possible reasons for variability in observed effects of glucosamine could be that, unlike prescription drugs, the quality of manufactured dietary supplements is not closely monitored in many countries. Therefore, there is the possibility that the actual amount of glucosamine present in a dietary supplement is different from that claimed on the label. The quality control of glucosamine supplements is further complicated by the unavailability of a simple and effective analytical method for the analysis of glucosamine. Therefore, the aim of this study was to develop a simple analytical method that could be easily adapted by the pharmaceutical industry for routine analysis of glucosamine. Aims: To develop a novel high-performance liquid chromatography (HPLC) method for the quantification of glucosamine, and determine the amount of glucosamine present in a sample of dietary supplements commercially available in Australia and India. Methods: Chromatographic separation of glucosamine was achieved using a zwitter-ionic hydrophilic interaction liquid chromatography column with a mobile phase consisting of 60% acetonitrile and 40% of 85 mM ammonium acetate, at a flow rate of 0.3 mL/min and column temperature 40°C. The developed method was validated for intra- and inter-day linearity, accuracy, precision, and reproducibility. The newly-developed method was subsequently used to analyse 12 glucosamine supplements. Results: The developed method was selective for glucosamine, which had a retention time of 5.9 min. The standard curve was linear with a correlation coefficient (r2) exceeding 0.99, over the range of 10–200 μg/mL for glucosamine. The relative standard deviations for intra- and inter-day accuracy, precision and reproducibility were all less than 4%. The amount of glucosamine determined in six Australian and six Indian glucosamine supplements ranged between 98.7–101.7% and 85.9–101.8% of the labelled values, respectively. Discussion: Unlike previous HPLC methods, this newly-developed HPLC technique does not require pre-derivatisation and can separate glucosamine from both hydrochloride and sulphate salts, and from other amino sugars, such as chondroitin sulphate present in dietary supplements. This simple and effective technique can be employed by analytical laboratories for the quality control of glucosamine dietary supplements. Conclusion: The current study has developed a new analytical technique using HPLC-Corona CAD, which can analyse underivatised glucosamine hydrochloride and sulphate within 6 minutes. Using the novel assay, we confirmed that unlike the tested Australian dietary supplements, only half of the tested Indian products had a glucosamine content within ±10% of what was claimed on the label. [ABSTRACT FROM AUTHOR]

Many parameters treated as constants in traditional physiologically based pharmacokinetic models must be formulated as time-varying quantities when modeling pregnancy and gestation due to the dramatic physiological and anatomical changes that occur during this period. While several collections of empirical models for such parameters have been published, each has shortcomings. We sought to create a repository of empirical models for tissue volumes, blood flow rates, and other quantities that undergo substantial changes in a human mother and her fetus during the time between conception and birth, and to address deficiencies with similar, previously published repositories. We used maximum likelihood estimation to calibrate various models for the time-varying quantities of interest, and then used the Akaike information criterion to select an optimal model for each quantity. For quantities of interest for which time-course data were not available, we constructed composite models using percentages and/or models describing related quantities. In this way, we developed a comprehensive collection of formulae describing parameters essential for constructing a PBPK model of a human mother and her fetus throughout the approximately 40 weeks of pregnancy and gestation. We included models describing blood flow rates through various fetal blood routes that have no counterparts in adults. Our repository of mathematical models for anatomical and physiological quantities of interest provides a basis for PBPK models of human pregnancy and gestation, and as such, it can ultimately be used to support decision-making with respect to optimal pharmacological dosing and risk assessment for pregnant women and their developing fetuses. The views expressed in this article are those of the authors and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency. [ABSTRACT FROM AUTHOR]

In many biological settings, two or more cells come into physical contact to form a cell-cell interface. In some cases, the cell-cell contact must be transient, forming on timescales of seconds. One example is offered by the T cell, an immune cell which must attach to the surface of other cells in order to decipher information about disease. The aspect ratio of these interfaces (tens of nanometers thick and tens of micrometers in diameter) puts them into the thin-layer limit, or “lubrication limit”, of fluid dynamics. A key question is how the receptors and ligands on opposing cells come into contact. What are the relative roles of thermal undulations of the plasma membrane and deterministic forces from active filopodia? We use a computational fluid dynamics algorithm capable of simulating 10-nanometer-scale fluid-structure interactions with thermal fluctuations up to seconds- and microns-scales. We use this to simulate two opposing membranes, variously including thermal fluctuations, active forces, and membrane permeability. In some regimes dominated by thermal fluctuations, proximity is a rare event, which we capture by computing mean first-passage times using a Weighted Ensemble rare-event computational method. Our results demonstrate a parameter regime in which the time it takes for an active force to drive local contact actually increases if the cells are being held closer together (e.g., by nonspecific adhesion), a phenomenon we attribute to the thin-layer effect. This leads to an optimal initial cell-cell separation for fastest receptor-ligand binding, which could have relevance for the role of cellular protrusions like microvilli. We reproduce a previous experimental observation that fluctuation spatial scales are largely unaffected, but timescales are dramatically slowed, by the thin-layer effect. We also find that membrane permeability would need to be above physiological levels to abrogate the thin-layer effect. [ABSTRACT FROM AUTHOR]

Bioengineering, which studies the principles and design of biological systems, is a field that has inspired the development of several technologies that are currently in use. In this work, we use concepts from the fish lateral line sensing mechanism and apply them to seismic imaging processing. The lateral line is a sensory system composed of an integrated array of mechanical sensors spanning along the fish body. We compare the array of sensors along body fish with the seismic acquisition, which employs an array of equally spaced identical mechanical sensors to image the Earth’s subsurface. In both situations, the mechanical sensors capture and process mechanical vibrations from the environment to produce useful information. We explore the strategy of using the low-pass and high-pass sensors schema of fish lateral line to improve the seismic technique. We use the full-wave inversion method to compare the conventional acquisition procedure of identical sensors with alternative sets of different sensors, which mimics the fish lateral line. Our results show that the alternate sensors arrangement surpasses the performance of the conventional acquisition method, using just half of the input information. The results point at an image processing technique that is computationally more efficient and economical than the usual seismic processing method. [ABSTRACT FROM AUTHOR]

Surfactin has antiviral activity against various enveloped viruses by inhibiting viral membrane fusion. However, the potential utility of surfactin as an antiviral drug is limited by its cytotoxicity. In this study, 10 surfactin analogues were obtained by chemical synthesis and evaluated to determine their anti-PEDV activities, hemolytic activities, and critical micelle concentrations. The main goal of our study was to develop a safer drug; a surfactin analogue with high anti-PEDV activity and low hemolytic activity. Compared with surfactin, one of the analogues we developed, SLP5, has lower hemolytic activity, with the same antiviral activity. The selectivity index of SLP5 is 52, while the SI for surfactin is 4, in other words, the safe and effective concentration range of SLP5 is 12 times greater than that of surfactin. Like surfactin, SLP5 has a direct antiviral effect on PEDV. Structurally, SLP5 is a linear lipopeptide with three carboxyl groups. Surfactin derivatives similar to SLP5 could be obtained by lactone bond hydrolyzation of surfactin, as well as total synthesis. [ABSTRACT FROM AUTHOR]

The traditional U-turn design has significantly improved traffic operations for relieving traffic congestion. However, the U-turn diversion and merge segments still cause traffic conflicts and delays. In this paper, an exclusive spur dike U-turn lane (ESUL) is proposed with the aim of addressing the disadvantages of the traditional U-turn design. ESUL provides a separate U-turn lane to diverge, decelerate, U-turn, accelerate and merge without interacting with through traffic. The effectiveness of ESUL is demonstrated through a field data investigation, simulation and analysis with VISSIM software. The proposed design is evaluated in terms of three parameters: travel time, delay and number of stops. Compared to the traditional U-turn design, ESUL can reduce travel time by 29.15%, delay by 66.70% and the number of stops by 100% at most. The results showed that ESUL has better performance than the traditional U-turn design and could be implemented to reduce traffic congestion and the potential hazards caused by U-turn maneuvers. [ABSTRACT FROM AUTHOR]

In this paper we set the previously reported pressure-dependent, ordinary differential equation outflow model by Smith and Gardiner for the human eye, into a new three-dimensional (3D) porous media outflow model of the eye, and calibrate model parameters using data reported in the literature. Assuming normal outflow through anterior pathways, we test the ability of 3D flow model to predict the pressure elevation with a silicone oil tamponade. Then assuming outflow across the retinal pigment epithelium is normal, we test the ability of the 3D model to predict the pressure elevation in Schwartz-Matsuo syndrome. For the first time we find the flow model can successfully model both conditions, which helps to build confidence in the validity and accuracy of the 3D pressure-dependent outflow model proposed here. We employ this flow model to estimate the translaminar pressure gradient within the optic nerve head of a normal eye in both the upright and supine postures, and during the day and at night. Based on a ratio of estimated and measured pressure gradients, we define a factor of safety against acute interruption of axonal transport at the laminar cribrosa. Using a completely independent method, based on the behaviour of dynein molecular motors, we compute the factor of safety against stalling the dynein molecule motors, and so compromising retrograde axonal transport. We show these two independent methods for estimating factors of safety agree reasonably well and appear to be consistent. Taken together, the new 3D pressure-dependent outflow model proves itself to capable of providing a useful modeling platform for analyzing eye behaviour in a variety of physiological and clinically useful contexts, including IOP elevation in Schwartz-Matsuo syndrome and with silicone oil tamponade, and potentially for risk assessment for optic glaucomatous neuropathy. [ABSTRACT FROM AUTHOR]

Lipid monolayers are used as experimental model systems to study the physical chemical properties of biomembranes. With this purpose, surface pressure/area per molecule isotherms provide a way to obtain information on packing and compressibility properties of the lipids. These isotherms have been interpreted considering the monolayer as a two dimensional ideal or van der Waals gas without contact with the water phase. These modelistic approaches do not fit the experimental results. Based on Thermodynamics of Irreversible Processes (TIP), the expansion/compression process is interpreted in terms of coupled phenomena between area changes and water fluxes between a bidimensional solution of hydrated head groups in the monolayer and the bulk solution. The formalism obtained can reproduce satisfactorily the surface pressure/area per lipid isotherms of monolayer in different states and also can explain the area expansion and compression produced in particles enclosed by bilayers during osmotic fluxes. This novel approach gives relevance to the lipid-water interaction in restricted media near the membrane and provides a formalism to understand the thermodynamic and kinetic response of biointerphases to biological effectors. [ABSTRACT FROM AUTHOR]

We revisit the CROS (“CRitical OScillations”) model which was recently proposed as an attempt to reproduce both scale-invariant neuronal avalanches and long-range temporal correlations. With excitatory and inhibitory stochastic neurons locally connected in a two-dimensional disordered network, the model exhibits a transition where alpha-band oscillations emerge. Precisely at the transition, the fluctuations of the network activity have nontrivial detrended fluctuation analysis (DFA) exponents, and avalanches (defined as supra-threshold activity) have power law distributions of size and duration. We show that, differently from previous results, the exponents governing the distributions of avalanche size and duration are not necessarily those of the mean-field directed percolation universality class (3/2 and 2, respectively). Instead, in a narrow region of parameter space, avalanche exponents obtained via a maximum-likelihood estimator vary continuously and follow a linear relation, in good agreement with results obtained from M/EEG data. In that region, moreover, the values of avalanche and DFA exponents display a spread with positive correlations, reproducing human MEG results. [ABSTRACT FROM AUTHOR]

Flow patterns of a Taylor-Couette-Poiseuille flow were studied at low axial Reynolds and rotational Taylor numbers (Re ≤ 10.5, Ta ≤ 319). The radius ratio of the inner and outer cylinders was 0.804 and the ratio of the length of the annulus to the gap width was 44.5. Complete map of the studied flow regimes was elaborated. The axial and azimuthal components of the wall shear rate γ were measured at the outer fixed cylinder using a three-segment electrodiffusion probe. The components of the wall shear rate of helices have never been measured in previous investigations. Spatio-temporal description of multiple flow patterns was obtained using flow visualizations and simultaneous measurements of wall shear rate components. The flow structures include Taylor vortices, helices winding in the same direction as the base flow or in the opposite direction, helices that were stagnant or moving in the axial direction, smooth or with superposed azimuthal waves, among others. The influence of different flow structures on the wall shear stress components is discussed with and without axial base flow. It was found that the wall shear stress is a function of Ta but no significant dependence on Re was observed for the studied flow regimes and that the mean wall shear stress increases with the number of azimuthal waves. It was also noted that the ED probes provide a more detailed information about flow patterns than torque measurements and visualizations described in the literature. [ABSTRACT FROM AUTHOR]

A randomized, double-blind, placebo-controlled, parallel-group comparative clinical study was conducted to examine the effects of ubiquinol (the reduced form of Coenzyme Q10) on secretion of saliva. This interventional study enrolled 40 subjects aged 65 years or younger who were healthy, but noted slight dryness of the mouth. Subjects were randomized with stratification according to gender and age to ingestion of gummy candy containing 50 mg of ubiquinol or placebo twice daily for 8 weeks. At the end of study, along with a significant increase of the CoQ10 level in saliva (p = 0.025*, d = 0.65), there was a significant increase of the saliva flow rate (p = 0.048*, d = 0.66) in the ubiquinol candy group (n = 18; 47.4±6.2 years; 6 men and 12 women) compared to the placebo group (n = 20; 52.2±7.7 years; 4 men and 16 women). The strength of the stomatognathic muscles was not significantly enhanced by ingestion of ubiquinol candy. Compared with baseline, significant improvement of the following four questionnaire items was observed in the ubiquinol group at the end of the study: feeling tired (p = 0.00506, d = −0.726), dryness of the mouth (p = 0.04799, d = −0.648), prone to catching a cold (p = 0.00577, d = −0.963), and diarrhea (p = 0.0166, d = −0.855). There were no serious adverse events. An in vitro study revealed that ubiquinol stimulated a significant and concentration-dependent increase of ATP production by a cell line derived from human salivary gland epithelial cells (p<0.05), while 1 nM ubiquinol significantly suppressed (p = 0.028) generation of malondialdehyde by cells exposed to FeSO4-induced oxidative stress. These findings suggest that ubiquinol increases secretion of saliva by suppressing oxidative stress in the salivary glands and by promoting ATP production. Trial Registration: UMIN-CTR . [ABSTRACT FROM AUTHOR]

Forests have become increasingly fragmented throughout the US, with residential development serving as the primary driver of these changes. These altered landscapes have provided suitable conditions for a broad range of wildlife, including blacklegged ticks and their hosts. Lawns dominate residential landscapes, and thus their management has the potential to reduce the likelihood of contact with ticks in residential yards. We tested the hypothesis that lawn mowing frequency influences tick occurrence in 16 suburban yards in Springfield, MA. We conducted 144 tick drags in lawns of various lawn mowing frequencies (mowed every week, every 2-weeks and every 3-weeks) and did not collect any ticks of any species. Promoting frequent mowing (i.e., shorter lawns) and the removal of grass clippings could have minimal impacts on tick microhabitats, but is consequential for beneficial wildlife and other ecosystem services associated with urban biodiversity. [ABSTRACT FROM AUTHOR]

The formation of metastases is driven by the ability of cancer cells to disseminate from the site of the primary tumour to target organs. The process of dissemination is constrained by anatomical features such as the flow of blood and lymph in the circulatory system. We exploit this fact in a stochastic network model of metastasis formation, in which only anatomically feasible routes of dissemination are considered. By fitting this model to two different clinical datasets (tongue & ovarian cancer) we show that incidence data can be modelled using a small number of biologically meaningful parameters. The fitted models reveal site specific relative rates of dissemination and also allow for patient-specific predictions of metastatic involvement based on primary tumour location and stage. Applied to other data sets this type of model could yield insight about seed-soil effects, and could also be used in a clinical setting to provide personalised predictions about the extent of metastatic spread. [ABSTRACT FROM AUTHOR]

Background: Colonoscopy remains the gold standard for the investigation of abnormalities within the colon. However, its success is highly dependent on the quality of bowel preparation. The objective of this study was to compare the bowel preparation efficacy of picosulfate/magnesium citrate (PMC) vs polyethylene glycol (PEG) in a one-day vs two-day split dose regimen. Methods: A prospective, randomized, controlled trial was conducted at the Forzani & MacPhail Colon Cancer Screening Centre in Calgary, Canada. 171 colonoscopy outpatients were randomized to split-dose PMC or PEG lavage as well as into one-day split or two-day split regimens in blocks of eight. Bowel preparation quality was recorded in a blinded manner by the endoscopist using the Ottawa Bowel Preparation Scale (OBPS) prior to washing or suctioning. The scale results were analyzed using a two-factor analysis of variance. Results: 141 patients received complete colonoscopies (PMC-71; PEG-70). PEG was found to be superior to PMC (mean OBPS: 4.14 ± 2.64 vs 5.11 ± 3.44, p = 0.019), when adjusted for administration regimen, leading to significantly more adequate bowel preparations (79.7% vs 59.7%, p = 0.007). A two-day split dose was superior to a one-day split dose regimen (mean OBPS: 3.68± 2.82 vs 5.69 ± 3.06, p<0.001). Two-day split dosing also resulted in a better right colon cleanliness score (right bowel OBPS 1.27±0.11 vs 2.10±0.12 for one-day split, P<0.001). Conclusions: Optimal bowel preparation was achieved with the use of PEG lavage when administered in a two-day split dose regimen. This trial is registered with ClinicalTrials.gov under identifier NCT01415687. [ABSTRACT FROM AUTHOR]

Background and objective: The idiopathic interstitial pneumonias (IIPs) are diffuse parenchymal lung disorders that are associated with substantial morbidity and mortality. Early diagnosis and disease stratification of IIP patients are important because these are related with the treatment and prognosis. Idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonia (NSIP) are two major distinctive pathologic patterns of pulmonary fibrosis. We researched the application of the fluid-structure interaction (FSI) to the respiratory system and compared the pulmonary acinus mechanics and functions in healthy and IIP models. Methods: The human pulmonary alveolus is idealized by a three-dimensional honeycomb-like geometry, and a fluid-structure interaction analysis is performed to study the normal and diseased breathing mechanics. The computational domain consists of two generations of alveolar ducts within the pulmonary acinus, with alveolar geometries approximated as closely packed 14-sided polygons. Findings: In a normal breathing cycle, the flow rate of the healthy model is significantly larger than that of the NSIP and IPF models. Similar trends are observed for the volume change and the maximum pressure drop. The flow rate and the volume change of the NSIP are almost the same as those of IPF. The maximum pressure drop of NSIP is 5.5% larger than that of IPF. There is a 47% decrease in the pulmonary acinus compliance for the NSIP and IPF compared with that of the healthy model. The acinus resistances of NSIP and IPF are higher than those of the healthy lung by 6.4~11.2%. In particular, the pulmonary acinus resistance of the NSIP lung is higher than that of the IPF lung by 4.5%. Conclusions: Our study demonstrates the differences of air flow and lung function in the pulmonary acinus between the healthy and the IIP models. These changes in the lung are important considerations for early diagnosis and disease stratification in patients. Patient-based geometry can to be included in the computational models in future studies. [ABSTRACT FROM AUTHOR]

Objective: Delay discounting (DD) is the choice of a smaller immediate reward over a larger delayed reward, which has been associated with a number of maladaptive behaviors. Episodic future thinking (EFT), the ability to project oneself into the future, is an intervention designed to reduce DD. EFT has reliable effects on DD, but the size of the effect varies, which could be due in part to the use of different control groups. Episodic recent thinking (ERT) serves as a common control for many EFT studies, but the temporal window of “recent” cues ranges from 24 hours ago to 12 days past. Since prior research has shown that retrospection can lead to prospection, it may be important to ensure that EFT controls do not inadvertently lead to prospection for some participants thereby increasing the variability of the control condition. The present study sought to develop a comparison group that standardizes the time frame and experiences that are the basis for the recent thinking control. Methods: Participants (n = 53, 18–45) were randomized to one of three conditions: EFT, ERT, or standardized episodic thinking (SET). Participants attended a laboratory appointment where they played mobile application games, created cues, and completed a DD task. Results: There was a significant difference between groups (p<0.05), with EFT reducing discounting more than either control (p<0.05), and no differences between ERT and SET (p>0.05). Conclusion: This study established that SET provides an alternative control in EFT studies and provides the advantage of standardizing the participant’s recent experience without changing the relationship between EFT and recent thinking controls. [ABSTRACT FROM AUTHOR]

A ride control system (RCS) based linear quadratic regulator (LQR) and genetic algorithm (GA) design is presented, to reduce the heave, roll and pitch motion (three degrees of freedom motion (3 DOF motion)) of the wave piercing catamarans (WPC) in beam waves. A detailed 3 DOF ride control model which consists of the coupling and decoupling relationships between longitudinal and transverse motion is proposed for the WPC vessel. And the complex hydrodynamic coefficients and disturbances induced by beam waves are analyzed. Moreover, two stern flaps are designed for the system in the way of alternate flapping. In the controller design, the LQR method based on GA method is adopted to reduce the 3 DOF motion of the ship. Depending on the robust search mechanism and global optimum of GA, weighting parameters can be obtained to calculate the desired gain. Finally, the motion reduction and motion sickness incidence (MSI) results demonstrate the feasibility and effectiveness of the proposed controller, and the comfort of passengers and crews can also be improved. [ABSTRACT FROM AUTHOR]

This study introduces a new method to understand how added load affects human performance across a broad range of athletic tasks (ten obstacles) embedded in an outdoor obstacle course. The method employs an array of wearable inertial measurement units (IMUs) to wirelessly record the movements of major body segments to derive obstacle-specific metrics of performance. The effects of load are demonstrated on (N = 22) participants who each complete the obstacle course under four conditions including unloaded (twice) and with loads of 15% and 30% of their body weight (a total of 88 trials across the group of participants). The IMU-derived performance metrics reveal marked degradations in performance with increasing load across eight of the ten obstacles. Overall, this study demonstrates the significant potential in using this wearable technology to evaluate human performance across multiple tasks and, simultaneously, the adverse effects of body-borne loads on performance. The study addresses a major need of military organizations worldwide that frequently employ standardized obstacle courses to understand how added loads influence warfighter performance. Importantly, the findings and conclusions drawn from IMU data would not be possible using traditional timing metrics used to evaluate task performance. [ABSTRACT FROM AUTHOR]

This work describes the use of entomological studies combined with in silico models (computer simulations derived from numerical models) to assess the efficacy of a novel device for controlled release of spatial repellents. Controlled Release Devices (CRDs) were tested with different concentrations of metofluthrin and tested against An. quadrimaculatus mosquitoes using arm-in cage, semi-field, and outdoor studies. Arm-in-cage trials showed an approximate mean values for mosquito knockdown of 40% and mosquito bite reduction of 80% for the optimal metofluthrin formulation for a 15-minute trial. Semi-field outdoor studies showed a mean mortality of a 50% for 24 hour trial and 75% for a 48 hour trial for optimal concentrations. Outdoors studies showed an approximate mean mortality rate of 50% for a 24 hour trial for optimal concentrations. Numerical simulations based on Computational Fluid Dynamics (CFD) were performed in order to obtain spatial concentration profiles for 24 hour and 48 hour periods. Experimental results were correlated with simulation results in order to obtain a functional model that linked mosquito mortality with the estimated spatial concentration for a given period of time. Such correlation provides a powerful insight in predicting the effectiveness of the CRDs as a vector-control tool. While CRDs represent an alternative to current spatial repellent delivery methods, such as coils, candles, electric repellents, and passive emanators based on impregnated strips, the presented method can be applied to any spatial vector control treatment by correlating entomological endpoints, i.e. mortality, with in-silico simulations to predict overall efficacy. The presented work therefore presents a new methodology for improving design, development and deployment of vector-control tools to reduce transmission of vector-borne diseases, including malaria and dengue. [ABSTRACT FROM AUTHOR]

Blood tests provide crucial diagnostic information regarding several diseases. A key factor that affects the precision and accuracy of blood tests is the interference of red blood cells; however, the conventional methods of blood separation are often complicated and time consuming. In this study, we devised a simple but high-efficiency blood separation system on a self-strained microfluidic device that separates 99.7 ± 0.3% of the plasma in only 6 min. Parameters, such as flow rate, design of the filter trench, and the relative positions of the filter trench and channel, were optimized through microscopic monitoring. Moreover, this air-difference-driven device uses a cost-effective and easy-to-use heater device that creates a low-pressure environment in the microchannel within minutes. With the aforementioned advantages, this blood separation device could be another platform choice for point-of-care testing. [ABSTRACT FROM AUTHOR]

In phytophagous sap-sucking insects, the precibarial valve plays an important role in sap ingestion. We used light and electron microspcopy to study the morphology and the ultrastructure of the precibarial valve of the meadow spittlebug, Philaenus spumarius (Hemiptera, Aphrophoridae), in order to better understand the operative mechanism of this structure. The precibarial valve revealed to be a complex structure with a bell-like invagination in the middle of the precibarium (on the epipharynx). Unlike the current hypothesis, we propose that the valve opens by dilator muscles and closes through cuticular and fluid tensions, the latter leading to morphological changes to the plane of the valve based on sap flow. Moreover, the presence of a precibarial secretory structure is described for the first time for auchenorrhynchan insects. In light of these observations, functions are hypothesized and discussed for this secretory structure. [ABSTRACT FROM AUTHOR]

Numerous technologies exist to detect circulating tumor cells (CTCs), although reports on cytological detection of CTCs remain limited. We recently developed a cytology-based CTC detection device using glass slides and light microscopy. In this study, we automated this previously manual device to improve its efficiency and cost effectiveness for clinical applications. We conducted a pilot study using this device to compare CTCs in peripheral blood (PB) and draining venous blood (DVB) from patients with colorectal cancer (CRC). The cytology-based automated CTC detection platform consisted of a disposable filtration device with a three-dimensional (3D) metal filter and multichannel automated CTC enrichment device. This platform allowed rapid and gentle filtration of CTCs and their efficient transfer from the filter to glass slides for subsequent Papanicolaou (Pap) and immunocytochemical (ICC) staining. Cytological diagnosis of CTCs was performed by observing permanent glass slide specimens by light microscopy. The current pilot clinical study enrolled CRC patients (n = 26) with stage I–IV tumors, who underwent surgery. PB was collected before surgery, and DVB was obtained from the mesenteric vein immediately after resection. Based on the CTC morphology obtained from PB and DVB samples, we proposed the following cytological criteria for the diagnosis of CTCs: pan-cytokeratin-positive, atypical cells with malignant morphological features identified by Pap staining. The numbers of CTCs defined by these criteria were significantly higher in DVB than PB from CRC patients (p<0.01), and the number of CTCs in DVB was increased significantly with stage progression (p<0.05). These results suggest that DVB may be another potential source of CTCs other than PB for liquid biopsies including downstream analysis. This automated cytology-based CTC detection device therefore provides a unique and powerful tool to investigate the significance of CTCs in CRC patients in a clinical setting. [ABSTRACT FROM AUTHOR]

Recent advancements have been made toward understanding the diagnostic and therapeutic potential of cerebrospinal fluid (CSF) and related hydrodynamics. Increased understanding of CSF dynamics may lead to improved detection of central nervous system (CNS) diseases and optimized delivery of CSF based CNS therapeutics, with many proposed therapeutics hoping to successfully treat or cure debilitating neurological conditions. Before significant strides can be made toward the research and development of interventions designed for human use, additional research must be carried out with representative subjects such as non-human primates (NHP). This study presents a geometric and hydrodynamic characterization of CSF in eight cynomolgus monkeys (Macaca fascicularis) at baseline and two-week follow-up. Results showed that CSF flow along the entire spine was laminar with a Reynolds number ranging up to 80 and average Womersley number ranging from 4.1–7.7. Maximum CSF flow rate occurred ~25 mm caudal to the foramen magnum. Peak CSF flow rate ranged from 0.3–0.6 ml/s at the C3-C4 level. Geometric analysis indicated that average intrathecal CSF volume below the foramen magnum was 7.4 ml. The average surface area of the spinal cord and dura was 44.7 and 66.7 cm2 respectively. Subarachnoid space cross-sectional area and hydraulic diameter ranged from 7–75 mm2 and 2–3.7 mm, respectively. Stroke volume had the greatest value of 0.14 ml at an axial location corresponding to C3-C4. [ABSTRACT FROM AUTHOR]

Blebs are cellular protrusions observed in migrating cells and in cells undergoing spreading, cytokinesis, and apoptosis. Here we investigate the flow of cytoplasm during bleb formation and the concurrent changes in cell volume using zebrafish primordial germ cells (PGCs) as an in vivo model. We show that bleb inflation occurs concomitantly with cytoplasmic inflow into it and that during this process the total cell volume does not change. We thus show that bleb formation in primordial germ cells results primarily from redistribution of material within the cell rather than being driven by flow of water from an external source. [ABSTRACT FROM AUTHOR]

A model has two main aims: predicting the behavior of a physical system and understanding its nature, that is how it works, at some desired level of abstraction. A promising recent approach to model building consists in deriving a Langevin-type stochastic equation from a time series of empirical data. Even if the protocol is based upon the introduction of drift and diffusion terms in stochastic differential equations, its implementation involves subtle conceptual problems and, most importantly, requires some prior theoretical knowledge about the system. Here we apply this approach to the data obtained in a rotational granular diffusion experiment, showing the power of this method and the theoretical issues behind its limits. A crucial point emerged in the dense liquid regime, where the data reveal a complex multiscale scenario with at least one fast and one slow variable. Identifying the latter is a major problem within the Langevin derivation procedure and led us to introduce innovative ideas for its solution. [ABSTRACT FROM AUTHOR]

Solar energy has become an important renewable energy source for reducing the use of fossil fuels and to mitigate global warming, for which solar collectors constitute a technology that is to be promoted. The use of nanofluids can increase the efficiency of solar into thermal energy conversion in solar collectors. Experimental values for the specific heat, thermal conductivity and viscosity of alumina/water nanofluids are needed to evaluate the influence of the solid content (from 0.25 to 5 v%) and the flow rate on the Reynolds, Nusselt and the heat transfer coefficient. In the laminar flow regime, thermal conductivity enhancement over specific heat decrement is key parameter, and a 2.34% increase in the heat transfer coefficient is theoretically obtained for 1 v% alumina nanofluid. To corroborate the results, experimental tests were run in a flat plate solar collector. A reduction in efficiency from 47% to 41.5% and a decrease in the heat removal factor were obtained using the nanofluid due to the formation of a nanoparticle deposition layer adding an addition thermal resistance to heat transfer. Nanofluids are recommended only if the nanoparticle concentration is high enough to enhance thermal conductivity, but no so high so as to avoid wall deposition. [ABSTRACT FROM AUTHOR]

We have developed the first computational model of solute and water transport from Bowman space to the papillary tip of the nephron of a human kidney. The nephron is represented as a tubule lined by a layer of epithelial cells, with apical and basolateral transporters that vary according to cell type. The model is formulated for steady state, and consists of a large system of coupled ordinary differential equations and algebraic equations. Model solution describes luminal fluid flow, hydrostatic pressure, luminal fluid solute concentrations, cytosolic solute concentrations, epithelial membrane potential, and transcellular and paracellular fluxes. We found that if we assume that the transporter density and permeabilities are taken to be the same between the human and rat nephrons (with the exception of a glucose transporter along the proximal tubule and the H+-pump along the collecting duct), the model yields segmental deliveries and urinary excretion of volume and key solutes that are consistent with human data. The model predicted that the human nephron exhibits glomerulotubular balance, such that proximal tubular Na+ reabsorption varies proportionally to the single-nephron glomerular filtration rate. To simulate the action of a novel diabetic treatment, we inhibited the Na+-glucose cotransporter 2 (SGLT2) along the proximal convoluted tubule. Simulation results predicted that the segment’s Na+ reabsorption decreased significantly, resulting in natriuresis and osmotic diuresis. [ABSTRACT FROM AUTHOR]

A new dynamic mode decomposition (DMD) method is introduced for simultaneous system identification and denoising in conjunction with the adoption of an extended Kalman filter algorithm. The present paper explains the extended-Kalman-filter-based DMD (EKFDMD) algorithm which is an online algorithm for dataset for a small number of degree of freedom (DoF). It also illustrates that EKFDMD requires significant numerical resources for many-degree-of-freedom (many-DoF) problems and that the combination with truncated proper orthogonal decomposition (trPOD) helps us to apply the EKFDMD algorithm to many-DoF problems, though it prevents the algorithm from being fully online. The numerical experiments of a noisy dataset with a small number of DoFs illustrate that EKFDMD can estimate eigenvalues better than or as well as the existing algorithms, whereas EKFDMD can also denoise the original dataset online. In particular, EKFDMD performs better than existing algorithms for the case in which system noise is present. The EKFDMD with trPOD, which unfortunately is not fully online, can be successfully applied to many-DoF problems, including a fluid-problem example, and the results reveal the superior performance of system identification and denoising. [ABSTRACT FROM AUTHOR]

Changes in 137Cs export over time following clearcutting were investigated in a Japanese forested catchment affected by the Fukushima nuclear accident. A total of 13% of the catchment area was clear-cut 2 years after the accident. Annual suspended solids (SS) export at the catchment outlet increased 1.4 to 2.0 times after clearcutting; however, 137Cs export increased slightly (up to 1.1 times), corresponding to 0.21% to 0.30% of the 137Cs inventory in the catchment. The smaller change in 137Cs export than in SS export was due to a rapid decrease in the activity concentration following clearcutting. This decrease was likely caused by both natural attenuation and SS derived from sources with a low activity concentration in the clear-cut area. Monitoring of the sediment transport from hillslopes in small-scale experimental plots showed that the 137Cs yield in the skid trail was 3.6 to 21 times greater than those in clear-cut and unlogged forest floors. This significant 137Cs transport was due to greater soil erosion (by up to two orders of magnitude) along the skid trail, despite the lower activity concentration than those in the other plots. This indicates that while skid trails were involved in the rapid decrease of the activity concentration of SS, they were a potential source of the increased export of 137Cs and SS. Net 137Cs export increased by clearcutting (the export excluding the decrease accompanied by natural attenuation) was estimated to account for only 0.092% of the inventory in the catchment for 2.5 years. These results imply that the impact of clearcutting on 137Cs export was temporary in this catchment. [ABSTRACT FROM AUTHOR]

The only way to visually observe cellular viscosity, which can greatly influence biological reactions and has been linked to several human diseases, is through viscosity imaging. Imaging cellular viscosity has allowed the mapping of viscosity in cells, and the next frontier is targeted viscosity imaging of organelles and their microenvironments. Here we present a fluorescent molecular rotor/FLIM framework to image both organellar viscosity and membrane fluidity, using a combination of chemical targeting and organelle extraction. For demonstration, we image matrix viscosity and membrane fluidity of mitochondria, which have been linked to human diseases, including Alzheimer’s Disease and Leigh’s syndrome. We find that both are highly dynamic and responsive to small environmental and physiological changes, even under non-pathological conditions. This shows that neither viscosity nor fluidity can be assumed to be fixed and underlines the need for single-cell, and now even single-organelle, imaging. [ABSTRACT FROM AUTHOR]