Shapes and singularities in triatic liquid crystal vesicles

Determining the equilibrium configuration and shape of curved two-dimensional films with (generalized) liquid crystalline (LC) order is a difficult infinite dimensional problem of direct relevance to the study of generalized polymersomes, soft matter and the fascinating problem of understanding the origin and formation of shape (morphogenesis). The symmetry of the free energy of the LC film being considered and the topology of the surface to be determined often requires that the equilibrium configuration possesses singular structures in the form of topological defects such as disclinations for nematic films. The precise number and type of defect plays a fundamental role in restricting the space of possible equilibrium shapes. Flexible closed vesicles with spherical topology and nematic or smectic order, for example, inevitably possess four elementary strength $+1/2$ disclination defects positioned at the four vertices of a tetrahedral shell. Here we address the problem of determining the equilibrium shape of flexible vesicles with generalized LC order. The order parameter in these cases is an element of $S^1/Z_p$, for any positive integer $p$. We will focus on the case $p =3$, known as triatic LCs. We construct the appropriate order parameter for triatics and find the associated free energy. We then describe the structure of the elementary defects of strength $+1/3$ in flat space. Finally, we prove that sufficiently floppy triatic vesicles with the topology of the 2-sphere equilibrate to octahedral shells with strength $+1/3$ defects at each of the six vertices, independently of scale.Comment: New results and new sections added, 4 new figures and updated abstrac

Antimicrobial activity of apple cider vinegar against Escherichia coli, Staphylococcus aureus and Candida albicans; downregulating cytokine and microbial protein expression

The global escalation in antibiotic resistance cases means alternative antimicrobials are essential. The aim of this study was to investigate the antimicrobial capacity of apple cider vinegar (ACV) against E. coli, S. aureus and C. albicans. The minimum dilution of ACV required for growth inhibition varied for each microbial species. For C. albicans, a 1/2 ACV had the strongest effect, S. aureus, a 1/25 dilution ACV was required, whereas for E-coli cultures, a 1/50 ACV dilution was required (p < 0.05). Monocyte co-culture with microbes alongside ACV resulted in dose dependent downregulation of inflammatory cytokines (TNFα, IL-6). Results are expressed as percentage decreases in cytokine secretion comparing ACV treated with non-ACV treated monocytes cultured with E-coli (TNFα, 99.2%; IL-6, 98%), S. aureus (TNFα, 90%; IL-6, 83%) and C. albicans (TNFα, 83.3%; IL-6, 90.1%) respectively. Proteomic analyses of microbes demonstrated that ACV impaired cell integrity, organelles and protein expression. ACV treatment resulted in an absence in expression of DNA starvation protein, citrate synthase, isocitrate and malate dehydrogenases in E-coli; chaperone protein DNak and ftsz in S. aureus and pyruvate kinase, 6-phosphogluconate dehydrogenase, fructose bisphosphate were among the enzymes absent in C.albican cultures. The results demonstrate ACV has multiple antimicrobial potential with clinical therapeutic implications

Developing Network Situational Awareness through Visualization of Fused Intrusion Detection System Alerts

With networks increasing in physical size, bandwidth, traffic volume, and malicious activity, network analysts are experiencing greater difficulty in developing network situational awareness. Traditionally, network analysts have used Intrusion Detection Systems to gain awareness but this method is outdated when analysts are unable to process the alerts at the rate they are being generated. Analysts are unwittingly placing the computer assets they are charged to protect at risk when they are unable to detect these network attacks. This research effort examines the theory, application, and results of using visualizations of fused alert data to develop network situational awareness. The fused alerts offer analysts fewer false-positives, less redundancy and alert quantity due to the pre-processing. Visualization offers the analyst quicker visual processing and potential pattern recognition. This research utilized the Visual Information Management toolkit created by Stanfield Systems Inc. to generate meaningful visualizations of the fused alert data. The fused alert data was combined with other network data such as IP address information, network topology and network traffic in the form of tcpdump data. The process of building Situational Awareness is an active process between the toolkit and the analyst. The analyst loads the necessary data into the visualization(s), he or she configures the visualization properties and filters the visualization(s). Results from generating visualizations of the network attack scenarios were positive. The analyst gained more awareness through the process of defining visualization properties. The analyst was able to filter the network data sources effectively to focus on the important alerts. Ultimately, the analyst was able to follow the attacker through the entry point in the network to the victims. The analyst was able to determine that the victims were compromised by the attacker. The analyst wasn\u27t able to definitively label the attack specifically yet the analyst was able to follow the attack effectively leading to Situational Awareness

Do grade II ankle sprains have chronic effects on the functional ability of ballet dancers performing single-leg flat-foot stance? An observational cross-sectional study

Ballet dancers have a higher risk than the general population of ankle sprains. Ankle proprioception is of the utmost importance for executing static and dynamic positions typical of ballet dancing. Ankle sprains can create changes in functional ability that may affect ballet performance. The aim of this cross-sectional observational study is to evaluate if non-professional ballet dancers that were previously injured with a grade II ankle sprain carry a long-term stability deficit in ballet specific positions (pass\ue9, arabesque) and in single-leg flat-foot stance, thereby affecting ballet performance. We enrolled 22 amateur female ballet dancers, 11 who previously had a grade II ankle injury and 11 who had no history of ankle injury. Stabilometric data (Center of Pressure Speed and Elipse Area) were assessed with the postural electronic multisensory baropodometer in normal, arabesque, and pass\ue8 positions with both open and closed eyes. Using an unpaired t-test, we compared healthy and pathological feet of the ankle injury group for a standard monopodalic position and two ballet-specific positions. No difference between pathological and healthy feet of non-professional ballet dancers who suffered grade II ankle injury was detected. According to the parameters considered in this study, grade II ankle sprains seem to have a favorable prognosis in the sample that we evaluated

Robots for Exploration, Digital Preservation and Visualization of Archeological Sites

Monitoring and conservation of archaeological sites are important activities necessary to prevent damage or to perform restoration on cultural heritage. Standard techniques, like mapping and digitizing, are typically used to document the status of such sites. While these task are normally accomplished manually by humans, this is not possible when dealing with hard-to-access areas. For example, due to the possibility of structural collapses, underground tunnels like catacombs are considered highly unstable environments. Moreover, they are full of radioactive gas radon that limits the presence of people only for few minutes. The progress recently made in the artificial intelligence and robotics field opened new possibilities for mobile robots to be used in locations where humans are not allowed to enter. The ROVINA project aims at developing autonomous mobile robots to make faster, cheaper and safer the monitoring of archaeological sites. ROVINA will be evaluated on the catacombs of Priscilla (in Rome) and S. Gennaro (in Naples)

Use of reciproc instruments with different motions: cyclic fatigue testing with simulation of the body temperature

Aim: To assess the influence of different motions on the cyclic fatigue resistance of Reciproc instruments simulating the temperature of the clinical conditions. Methods: The sample size was determined using statistical software set with the following parameters: \u3b1=0.05, \u3b2=0.20, \u3b4=30.0, \u3c3=28.0. The experiment required 54 Reciproc files. Brand new R25 files were randomly allocated to three groups defined by the tested motion: continuous rotation at 300 rpm (n=18), \u201cRECIPROC\u201d mode (n=18), and \u201cWAVEONE\u201d mode (n=18). The same endodontic motor was used for all groups (X-Smart IQ). All files were rotated/reciprocated until fracture inside a custom-designed artificial canal with 60\ub0 angle and 5-mm radius of curvature milled in a stainless-steel block. The testing device was electrically heated to keep its internal temperature at 35\ub11\ub0C, which was constantly monitored with a thermometer. After file separation, the time to failure was registered with a digital chronometer and the length of the fractured fragment measured with a digital calliper. The fracture surface of each file was observed at the scanning electron microscope to perform a qualitative fractographic analysis. The collected data (time to fracture and fracture length) were tested for the normality of the distribution and the equality of variances with a Shapiro-Wilk and a Levene test, respectively. The dependent variables were compared amongst groups by means of a multivariate analysis of variance and Tuckey post-hoc test (p=0.05). Results: The continuous rotation group exhibited the shortest lifespan among the considered groups (85.4\ub19.5 s to failure). Both reciprocating motions were associated with a significant improvement of fatigue resistance (p<0.001). The \u201cRECIPROC\u201d mode allowed for longer time to failure than the \u201cWAVEONE\u201d mode, with 141.6\ub119.4 s and 117.2\ub111.2 s to failure, respectively. The absence of differences among the considered groups in terms of fracture length confirmed the correct positioning of the files inside the artificial canal. The scanning electron microscopic analysis showed signs of file separation ascribable to cyclic fatigue. Conclusion: The present study preliminary demonstrated that the native \u201cRECIPROC\u201d motion use of R25 Reciproc files should be preferred over other types of motions to prevent file separation in the clinical setting

Driven Dipolariton Transistors in Y-shaped Channels

Exciton-dipolaritons are investigated as a platform for realizing working elements of a polaritronic transistor. Exciton-dipolaritons are three-way superposition of cavity photons, direct and indirect excitons in a bilayer semiconducting system embedded in an optical microcavity. Using the forced diffusion equation for dipolaritons, we study the room-temperature dynamics of dipolaritons in a transition-metal dichalcogenide (TMD) heterogeneous bilayer. Specifically, we considered a MoSe2-WS2 heterostructure, where a Y-shaped channel guiding the dipolariton propagation is produced. We demonstrate that polaritronic signals can be redistributed in the channels by applying a driving voltage in an optimal direction. Our findings open a route towards the design of an efficient room-temperature dipolariton-based optical transistor

Nuclear Recoil Scintillation Linearity of a High Pressure 4^4He Gas Detector

We investigate scintillation linearity of a commercial high pressure $^4$He gas detector using monoenergetic 2.8 MeV neutrons from a deuterium-deuterium fusion neutron generator. The scintillation response of the detector was measured for a range of recoil energies between 83 keV and 626 keV by tagging neutrons scattering into fixed angles with a far-side organic scintillator detector. Detailed Monte Carlo simulations were compared to experimental data to determine the linearity of the detector response by comparing the scaling of the energy deposits in the simulations to the detector output. In this analysis, a linear scintillation response corresponds to a consistent value for the scaling factor between simulated energy deposits and experimental data for several different scattering angles. We demonstrate that the detector can be used to detect fast neutron interactions down to 83 keV recoil energies and can be used to characterize low-energy neutron sources, one of its potential applications