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Contact angle goniometry is an important characterization technique that can determine crucial information, such as the wettability, interfacial tension, and adhesion properties of solid and liquid surfaces alike. However, while this technique is already widespread, the by-hand analysis process of elucidating the advancing and receding contact angles (ARCAs) from the actual data set has many pitfalls and is fraught with human error. In this article, we introduce a graphical user interface (GUI) called ARCA Finder that drastically simplifies the analysis process by displaying the contact angle data in a novel perspective and aiding the user to determine the most accurate measurement from the available data based on the full definition of the dynamic contact angles. The goal of this invention is to improve measurement accuracy by reducing human error in goniometry, while also improving the repeatability of measurements among different researchers. By testing this approach alongside by-hand analysis on both synthetic and real dynamic contact angle videos, our results demonstrate a noticeable difference in the measured values, which suggests that the ARCA Finder GUI improves the measurement accuracy compared to the standard approach. [ABSTRACT FROM AUTHOR]

This report investigates how different splashing mechanisms affect the oblique splash threshold of drops impacting a dry solid surface. The splashing behaviors of water, ethanol, and a water/ethylene glycol solution are observed over a wide range of drop diameters (0.7 mm < D < 2.2 mm) and Weber numbers (10 < We < 1040), and several published models are tested in order to predict the thresholds between deposition, one-sided splashing, and two-sided splashing. We found that the splash threshold of liquids that exhibit the corona splashing mechanism can be readily predicted by existing models. However, for liquids such as water that exhibit prompt splashing, the oblique splash threshold is not successfully predicted by any presently established correlation. Hence, our findings identify a critical knowledge gap in the drop impact field, since the behavior of water is of fundamental importance to countless engineering problems. Finally, combining our own results with others reported in the literature, we address some contradictory reports about the influence of liquid viscosity on the splash threshold and demonstrate that the presence or lack of thin-sheet in different experiments could explain the contradictions present in the literature. [ABSTRACT FROM AUTHOR]

Single-step, contactless femtosecond laser micromachining of substrates to impart specific surface morphologies has been the focus of considerable recent work. This work has primarily focused on experimentation with metallic substrates, with fs-laser micromachining of polymeric materials being in its infancy. In the present work, we report on the fs-laser micromachining of urethane based, amorphous, non-block co-polymeric networks, where previously published literature has, to-date, solely discussed micromachining of homopolymeric substrates. The results of this work show that there exists regimes of micromachining where the imparted microstructure resembles those of selected irradiated homopolymers. Further inspection reveals the role of co-monomer added in determining the imparted microstructure through measurement of the material ionization threshold fluence, and incubation coefficient. Chemical and optical effects of co-monomer addition are also considered through XPS and UV–Vis spectroscopic analyses, respectively. Unlabelled Image • Porous microstructures are manifested on fs-laser irradiated copolymeric substrates. • The porous microstructures resemble those reported for irradiated homopolymers. • The regime for pore formation is governed by the material threshold fluence. • The addition of a comonomer depresses the material threshold fluence. • No correlation is seen between comonomer added and micromachining parameters. [ABSTRACT FROM AUTHOR]

Understanding how to influence ice adhesion to structures and prevent icing catastrophes is a paramount research question. Conventional industrial anti-icing methods are active, requiring an energy source. However, active strategies are energy intensive. Passive anti-icing surfaces have thus become an area of engineering interest. Such strategies, like low surface energy chemical coatings, produce highly anti-icing surfaces on a lab-scale but they have not succeeded in industrial applications. They lack efficacy over repeated icing/de-icing cycles and their materials are unsuited for harsh environments. The body feather of the sub-Antarctic Gento penguin Pygoscelis papua , which ornithologists note is perpetually free of ice despite its freezing environment, serves as a compelling source of passive anti-icing biomimetic inspiration which may overcome these aforementioned deficiencies. Through studying these feathers, it has become clear that two aspects of anti-icing (water-shedding and ice-shedding) are addressed in distinct ways by the Gentoo penguin. The water-shedding functionality of the feathers is derived from an air cushion created by the wire-like microstructure of the feather and is augmented by nano-scale grooves in the feather coated in preen oil. The preen oil is necessary to maintain water-shedding functionality, however once removed the ice-shedding functionality of the feathers is maintained. The ice-shedding functionality appears to be derived from wire-like morphology of the penguin body feather barbs and barbules which induce cracks that are easily opened at the ice-feather interface. Such a design strategy shows promise in addressing the common failings of passive systems. These anti-icing strategies were then tested on metallic biomimetic substrates. The barb structure of the penguin body feather was mimicked using ultra-fine woven stainless-steel wire cloth. Some stainless-steel wire cloths were laser machined to mimic the texturing and surface chemistry of the feathers. These cloths were indeed hydrophobic like the feathers. Both stainless-steel wire cloths had significantly reduced ice adhesion strengths compared to those of the flat monolithic stainless-steel sample. The laser-machined wire cloth had an ice adhesion strength of 63 ± 10 kPa compared to 603 ± 236 kPa for the flat sample. This both indicates that the ice-shedding capabilities of the sample are imparted by the structure and further strengthens the argument that water-shedding and ice-shedding are distinct phenomena that need to be addressed with two separate design strategies. • The sub-Antarctic penguin body feather exhibits ice-shedding and water-shedding functionality. • Ice-shedding functionality is derived from the wire-like morphology of the body feather. • Water-shedding functionality is derived from superimposed nano-ripples and preening oil. • Biomimicry using a woven cloth allows us to create a passive ice-shedding surface out of bare metal. • Laser-induced nano-ripples superimposed on the wire cloth mimics water-shedding functionality. [ABSTRACT FROM AUTHOR]

Abstract Right-wing authoritarianism (RWA) has shown inconsistent results as a predictor of beliefs in conspiracy theories (CTs). The present investigation attempted to clarify these results by separating anti-establishment CTs, which challenge the existing social order, from pro-establishment CTs, which seek to justify and reinforce it against external threats. In two MTurk samples (N = 294, 200), RWA correlated strongly with pro-establishment CTs but weakly with anti-establishment CTs. Regression analyses suggest that after controlling for exposure to the CTs, this gap in the predictive power of RWA can be explained by differences in attitudes toward their alleged perpetrators, highlighting the importance of intergroup attitudes as an important driver of CT endorsement. [ABSTRACT FROM AUTHOR]

The present study investigates the characteristics of discussion of conspiracy theories about the Zika virus outbreak of 2015-16 on Twitter. Content and social network analysis of a dataset of 25,162 original Tweets about Zika virus conspiracy theories showed that relative to debunking messages, conspiracy theories spread through a more decentralized network, are more likely to invoke supposedly knowledgeable authorities in making arguments, and ask more rhetorical questions. These trends can be understood in the context of previous work on conspiracy theories, including the "just asking questions" style of rhetoric, the importance of sourcing and authority, and the tendency to simultaneously consider many different potential conspiracies that might underlie an important topic or event. [ABSTRACT FROM AUTHOR]

Research on the psychology of conspiracy theories has shown recent steps towards a standardization of measures. The present article seeks to continue that trend by presenting the Flexible Inventory of Conspiracy Suspicions ( FICS), a questionnaire template that can be adapted to measure suspicions of a conspiracy around nearly any topic of public interest. Compared to conspiracy belief measures that ask about specific theories on a given topic, the FICS is worded in such a way as to provide relatively stable validity across time and cultural context. Using a hybrid approach incorporating classical test theory and Rasch scaling, three questionnaire studies on Mechanical Turk demonstrate the validity of the FICS in measuring conspiracy suspicions regarding 9/11, vaccine safety, and US elections, with good psychometric properties in most situations. However, the utility of the FICS is limited in the case of climate change due to the existence of two opposing conspiracy theories that share essentially no common assumptions ('climate change is a hoax' vs. 'there is a conspiracy to make people believe that climate change is a hoax'). The results indicate that the FICS is a reliable and valid measure of conspiracy suspicions within certain parameters, and suggest a three-level model that differentiates general conspiracist ideation, relatively vague conspiracy suspicions, and relatively specific conspiracy beliefs. [ABSTRACT FROM AUTHOR]

'Conspiracy theory' is widely acknowledged to be a loaded term. Politicians use it to mock and dismiss allegations against them, while philosophers and political scientists warn that it could be used as a rhetorical weapon to pathologize dissent. In two empirical studies conducted on Amazon Mechanical Turk, I present an initial examination of whether this concern is justified. In Experiment 1, 150 participants judged a list of historical and speculative theories to be no less likely when they were labeled 'conspiracy theories' than when they were labeled 'ideas.' In Experiment 2 (N = 802), participants who read a news article about fictitious 'corruption allegations' endorsed those allegations no more than participants who saw them labeled 'conspiracy theories.' The lack of an effect of the conspiracy-theory label in both experiments was unexpected and may be due to a romanticized image of conspiracy theories in popular media or a dilution of the term to include mundane speculation regarding corruption and political intrigue. [ABSTRACT FROM AUTHOR]

In this report we investigate the performance of various beam shutter technologies when applied to femtosecond laser micromachining. Three different shutter options are considered: a mechanical blade shutter, a bistable rotary solenoid shutter, and an electro-optic modulator (EOM) shutter. We analyzed the behavior of each shutter type during repeated open/close commands (period of 10 ≤ T ≤ 200 ms) using both high-speed videography and practical micromachining experiments. To quantify the performance at varying cycle periods, we introduce a new variable called the compliance that characterizes the average state of the shutter with respect to its intended position. We found that the solenoid shutter responds poorly to sequential commands. The mechanical shutter provides reliable performance for cycled commands as short as T = 40 ms, but begins to lag significantly behind the control signal for T ≤ 20 ms. The EOM shutter provides the most precise and reliable performance, with an opening time of only 0.6 ms and a high compliance with the signal commands, even when cycled very quickly (T = 10 ms). Overall, this study acts as an extensive practical guide for other laser users when considering different shutter options for their laser system and desired application. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study is to examine the use of daikenchuto (DKT), a traditional Japanese medicine, as a potential treatment for opiate-induced slowing of intestinal transit in an isolated guinea pig colon model of motility. Methods: Isolated segments of distal guinea pig colon were mounted in a perfusion chamber and imaged with a digital video camera interfaced with a computer. Fecal pellets were inserted into the oral end of the colonic segment and the rates of propulsive motility over a 3 to 4cm segment of colon were determined in the presence and absence of test compounds. In addition, intracellular recordings were obtained from intact circular muscle, and the responsiveness of inhibitory and excitatory junction potentials to DKT was evaluated. Results: The addition of D-Ala2, N-Me-Phe4, Gly-ol5 (DAMGO), a selective μ-receptor agonist, caused a concentration dependent decrease in colon motility. Naloxone did not affect basal activity, but partially restored motility in the DAMGO treated preparations. DKT (1×10−4–3×10−4g/mL) also reversed the inhibitory effect of DAMGO treated colon in a concentration dependent manner. At higher concentrations (1×10−3–3×10−3g/mL), however, this effect was lost. Motility slowed even further when naloxone and DKT were combined with noticeable disruptions in spatiotemporal patterns. Interestingly, when added alone, DKT resulted in reverse peristalsis of the pellet. In electrophysiologic studies DKT inhibited both excitatory and inhibitory junction potentials. Conclusions: DKT appears to be as effective as naloxone in restoring motility in DAMGO treated colon. These two agents, however, do not appear to have an additive effect. When used on untreated colon segments, DKT appears to cause disruptions in the intrinsic reflex circuit of the gut resulting in a disruption of neuromuscular communication. [ABSTRACT FROM AUTHOR]

In this work, we investigate the fabrication of stainless-steel substrates decorated with laser-induced periodic surface structures (LIPSS) of both hydrophilic and hydrophobic wettability through different post-processing manipulation. In carrying out these experiments, we have found that while a CO2-rich atmosphere during irradiation does not affect final wettability, residence in such an atmosphere after irradiation does indeed increase hydrophobicity. Contrarily, residence in a boiling water bath will instead lead to a hydrophilic surface. Further, our experiments show the importance of removing non-sintered nanoparticles and agglomerates after laser micromachining. If they are not removed, we demonstrate that the nanoparticle agglomerates themselves become hydrophobic, creating a Cassie air-trapping layer on the surface which presents with water contact angles of 180°. However, such a surface lacks robustness; the particles are removed with the contacting water. What is left behind are LIPSS which are integral to the surface and have largely been blocked from reacting with the surrounding atmosphere. The actual surface presents with a water contact angle of approximately 80°. Finally, we show that chemical reactions on these metallic surfaces decorated with only LIPSS are comparatively slower than the reactions on metals irradiated to have hierarchical roughness. This is shown to be an important consideration to achieve the highest degree of hydro-philicity/phobicity possible. For example, repeated contact with water from goniometric measurements over the first 30 days following laser micromachining is shown to reduce the ultimate wettability of the surface to approximately 65°, compared to 135° when the surface is left undisturbed for 30 days. [ABSTRACT FROM AUTHOR]

Introduction: In recent years, Clostridium difficile-associated infection has emerged as an increasingly problematic entity. More virulent strains have been isolated and new manifestations of the infection have been described.Purpose: The primary aim of this manuscript is to describe what we believe to be the first reported case of devastating C. difficile enteritis in a patient with an ileal reservoir.Conclusion: A high index of suspicion is required in the appropriate clinical setting in light of the apparently changing spectrum of C. difficile disease. [ABSTRACT FROM AUTHOR]

The production of millimetric liquid droplets has importance in a wide range of applications both in the laboratory and industrially. As such, much effort has been put forth to devise methods to generate these droplets on command in a manner which results in high diameter accuracy and precision, well-defined trajectories followed by successive droplets and low oscillations in droplet shape throughout their descents. None of the currently employed methods of millimetric droplet generation described in the literature adequately addresses all of these desired droplet characteristics. The reported methods invariably involve the cohesive separation of the desired volume of liquid from the bulk supply in the same step that separates the single droplet from the solid generator. We have devised a droplet generation device which separates the desired volume of liquid within a tee-apparatus in a step prior to the generation of the droplet which has yielded both high accuracy and precision of the diameters of the final droplets produced. Further, we have engineered a generating tip with extreme antiwetting properties which has resulted in reduced adhesion forces between the liquid droplet and the solid tip. This has yielded the ability to produce droplets of low mass without necessitating different diameter generating tips or the addition of surfactants to the liquid, well-defined droplet trajectories, and low oscillations in droplet volume. The trajectories and oscillations of the droplets produced have been assessed and presented quantitatively in a manner that has been lacking in the current literature. [ABSTRACT FROM AUTHOR]

The contact angle (CA) of a drop is a common quantitative measurement that describes a surface's wettability. However, manual selection of the drop's solid–liquid–vapor contact points (CPs) by the user introduces substantial human error to the final measured CA. Hence, in this article we introduce a novel method for CA measurement that uses a smoothing spline function to simultaneously cancel probable image noise, find the solid–liquid contact point, and calculate the CA at the contact point. The accuracy of this technique is tested through measurement of a series of synthetic drop images with known CAs ranging from 5°to 175°, which are generated using a new mathematical approach and include a reflection area to accurately model real experiments. In these tests, the smoothing splines approach is shown to be extremely accurate in measuring both the CP position and the CA, with negligible error ( R 2 = 0. 9999). Then, for added validation, the smoothing splines approach is tested on four real surfaces of different wettability: glass, single crystal silicon, polished polytetrafluoroethylene, and patterned superhydrophobic polytetrafluoroethylene. When tested on real surfaces, the smoothing splines measurement approach provides reliable contact angle data for all four different surfaces tested, while also reducing human error. Overall, our proposed measurement approach for the CA is shown to be more accurate than traditional measurement approaches such as the commonly used polynomial fitting approach, and the more recently introduced mask approach, which also includes automatic CP detection. [Display omitted] • Automated contact point detection. • Smooth spline method is implemented to find the contact point and measure the contact angle. • Canceling probable noises. • Creating synthetic drop to evaluate the method accuracy. • Testing method with real surfaces of different wettability. [ABSTRACT FROM AUTHOR]

OBJECTIVES:Changes in mucosal serotonin (5-HT) signaling have been detected in a number of functional and inflammatory disorders of the gastrointestinal (GI) tract. This study was undertaken to determine whether chronic constipation (CC) is associated with disordered 5-HT signaling and to evaluate whether constipation caused by opiate use causes such changes.METHODS:Human rectal biopsy samples were obtained from healthy volunteers, individuals with idiopathic CC, and individuals taking opiate medication with or without occurrence of constipation. EC cells were identified by 5-HT immunohistochemistry. 5-HT content and release levels were determined by enzyme immunoassay, and mRNA levels for the synthetic enzyme tryptophan hydroxylase-1 (TpH-1) and serotonin-selective reuptake transporter (SERT) were assessed by quantitative real-time reverse transcription PCR.RESULTS:CC was associated with increases in TpH-1 transcript, 5-HT content, and 5-HT release under basal and stimulated conditions, whereas EC cell numbers and SERT transcript levels were not altered. No changes in these elements of 5-HT signaling were detected in opiate-induced constipation (OIC).CONCLUSIONS:These findings demonstrate that CC is associated with a pattern of altered 5-HT signaling that leads to increased 5-HT availability but does not involve a decrease in SERT expression. It is possible that increased 5-HT availability due to increased synthesis and release contributes to constipation due to receptor desensitization. Furthermore, the finding that elements of 5-HT signaling were not altered in the mucosa of individuals with OIC indicates that constipation as a condition does not lead to compensatory changes in 5-HT synthesis, release, or signal termination. [ABSTRACT FROM AUTHOR]