323 research outputs found

    A Chatbot Framework for Yioop

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    Over the past few years, messaging applications have become more popular than Social networking sites. Instead of using a specific application or website to access some service, chatbots are created on messaging platforms to allow users to interact with companies’ products and also give assistance as needed. In this project, we designed and implemented a chatbot Framework for Yioop. The goal of the Chatbot Framework for Yioop project is to provide a platform for developers in Yioop to build and deploy chatbot applications. A chatbot is a web service that can converse with users using artificial intelligence in messaging platforms. Chatbots feel more like a human and it changes the interaction between people and computers. The Chatbot Framework enables developers to create chatbots and allows users to connect with them in the user chosen Yioop discussion channel. A developer can incorporate language skills within a chatbot by creating a knowledge base so that the chatbot understands user messages and reacts to them like a human. A knowledge base is created by using a language understanding web interface in Yioop

    Statistical properties of fracture in a random spring model

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    Using large scale numerical simulations we analyze the statistical properties of fracture in the two dimensional random spring model and compare it with its scalar counterpart: the random fuse model. We first consider the process of crack localization measuring the evolution of damage as the external load is raised. We find that, as in the fuse model, damage is initially uniform and localizes at peak load. Scaling laws for the damage density, fracture strength and avalanche distributions follow with slight variations the behavior observed in the random fuse model. We thus conclude that scalar models provide a faithful representation of the fracture properties of disordered systems.Comment: 12 pages, 17 figures, 1 gif figur

    Crack avalanches in the three dimensional random fuse model

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    We analyze the scaling of avalanche precursors in the three dimensional random fuse model by numerical simulations. We find that both the integrated and non-integrated avalanche size distributions are in good agreement with the results of the global load sharing fiber bundle model, which represents the mean-field limit of the model.Comment: 6 pages, 2 figures, submitted for the proceedings of the conference "Physics Survey of Irregular Systems", in honor of Bernard Sapova

    Scaling of Fracture Strength in Disordered Quasi-Brittle Materials

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    This paper presents two main results. The first result indicates that in materials with broadly distributed microscopic heterogeneities, the fracture strength distribution corresponding to the peak load of the material response does not follow the commonly used Weibull and (modified) Gumbel distributions. Instead, a {\it lognormal} distribution describes more adequately the fracture strengths corresponding to the peak load of the response. Lognormal distribution arises naturally as a consequence of multiplicative nature of large number of random distributions representing the stress scale factors necessary to break the subsequent "primary" bond (by definition, an increase in applied stress is required to break a "primary" bond) leading up to the peak load. Numerical simulations based on two-dimensional triangular and diamond lattice topologies with increasing system sizes substantiate that a {\it lognormal} distribution represents an excellent fit for the fracture strength distribution at the peak load. The second significant result of the present study is that, in materials with broadly distributed microscopic heterogeneities, the mean fracture strength of the lattice system behaves as μf=μf(LogL)ψ+cL\mu_f = \frac{\mu_f^\star}{(Log L)^\psi} + \frac{c}{L}, and scales as μf1(LogL)ψ\mu_f \approx \frac{1}{(Log L)^\psi} as the lattice system size, LL, approaches infinity.Comment: 24 pages including 11 figure

    Pharmacovigilance: The Role Of Pharmaceutical Companies To Protect Patients From Adverse Drug Reactions

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    Health Care Professionals (HCPs) play a vital role in the early detection, assessment and reporting of Adverse Drug Reactions (ADRs) to the Regulatory Health Authority or Pharmaceutical Manufacturer. It’s always important that HCPs should improve continuously about their knowledge, attitude and their practice towards Pharmacovigilance and ADR reporting. The main goal of the research study is to evaluate whether if pharmacovigilance training provided by the Pharmaceutical Company will improve the HCP’s knowledge, their attitude and practice improves towards Pharmacovigilance and ADR reporting (Alan, Melike, Sule , Burcu, & Yusuf , 2013). The training is provided through the electronic learning management system. The learning management system (LMS) will be implemented using the Waterfall Methodology (Foreman, 2013)

    Crystal-Amorphous Transformation Via Defect-Templating in Phase-Change Materials

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    Phase-change materials (PCM) such as GeTe and Ge-Sb-Te alloys are potential candidates for non-volatile memory applications, because they can reversibly and rapidly transform between a crystalline phase and an amorphous phase with medium-range order. Traditionally, crystal-amorphous transformation in these materials has been carried out via melt-quench pathway, where the crystalline phase is heated beyond its melting point by the rising edge of an electric pulse, and the melt phase is quenched by the falling edge into a glassy phase. Formation of an intermediate melt phase in this transformation pathway requires usage of large switching current densities, resulting in energy wastage, and device degradation issues. Furthermore, melt-quench pathway is a brute force strategy of amorphizing PCM, and does not utilize the peculiar structural properties in crystalline phase. It will be beneficial from a device perspective that crystal-amorphous transformation is carried out via subtler solid-state pathways. Single-crystalline nanowire phase-change memory, owing to its lateral geometry and large volumes of active material, offers a platform to construct a crystal-amorphous transformation pathway via gradually increasing disorder in the crystalline phase, and study it. Using in situ transmission electron microscopy on GeTe and Ge2Sb2Te5 systems, we showed that the application of an electric pulse (heat-shock) creates dislocations in the PCM that migrate with the hole-wind force, and interact with the already existing ferroelectric boundaries in case of GeTe, changing their nature. We adapted novel tools such as optical second harmonic generation polarimety to carefully study these defect interactions. These defects accumulate at a region of local inhomogeneity, and upon addition of defects beyond a critical limit to that region via electrical pulsing, an amorphous phase nucleates . We also studied the effect of defect dynamics on carrier transport using temperature dependent transport measurements in GeTe, which transforms from a metal to a weakly localized metal to finally an Andersons insulator, upon defect accumulation, prior to amorphization. Taking lessons from these fundamental studies, we defect-engineered GeTe into insulating crystalline states as the starting crystalline states, and demonstrated orders of magnitude drop in the power densities required for switching, compared with those required for melt-quench pathway

    DEVELOPMENT OF ABUSE DETERRENT FORMULATIONS USING HOT MELT EXTRUSION

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    In recent years prescription drug diversion, misuse, abuse represent a growing problem for the United States. Oral ingestion, snorting, injection are most commonly employed routes of abuse. To circumvent this problem hot melt extrusion (HME) was employed to prepare abuse deterrent formulation (ADF). Abuse Deterrent Immediate Release Egg-Shaped Tablet Using 3D Printing Technology: Quality by Design to Optimize Drug Release and Extraction. In current work, we developed egg-shaped tablet (egglet) using fused deposition modeling (FDM) 3D printing. Drug-loaded polymeric filaments (1.5 mm) were prepared using HME followed by printing into egglets of different sizes and infill densities. Based on printability, crush resistance polyvinyl alcohol (PVA) was used further. Later, egglets were evaluated for abuse deterrence properties based on USFDA guidance. A multifactorial design was used to optimize solvent extraction, drug release. Extreme hardness (\u3e 500 N), large particle size (\u3e 1 mm) on mechanical manipulation established snorting deterring property while \u3c20% drug extraction in 5 min (% Sext) demonstrated deterrence for injection abuse. Quality target product profile D85 \u3c 30 min, % Sext \u3c 20 was achieved with egglets of 6 mm diameter, 45% infill density, 15% w/w drug loading. Development of Multi-dose Oral Abuse Deterrent Formulation of Loperamide Using Hot melt extrusion. Loperamide, an over the counter anti-diarrheal drug, also referred as poor man\u27s methadone . Abusers consume more than 30 tablets to achieve euphoria and to combat opioid withdrawal. But supratherapeutic doses causes respiratory depression, cardiac dysrhythmia, mortality. Aim is designing a tablet which can immediate release loperamide in diarrheic patients (single tablet) while stops release in case of intentional multi-dose ingestion. Loperamide was molecularly dispersed into gastric soluble cationic polymers - Eudragit® EPO, Kollicoat® Smartseal 100P using HME to obtain filament. Filaments were milled and compressed into tablets ((Eudragit® EPO (SJU1) and Kollicoat® Smartseal (SJU2)) with optimized amount of L-arginine. Dissolution in 250 mL of Fasted state simulated gastric fluid (FaSSGF) revealed that single tablet of Imodium® (marketed formulation) and SJU1 showed \u3e85% of release in 15 min. In multi-unit dissolution (15 tablets), Imodium® exhibited \u3e90% release but SJU tablets showed \u3c5% of release thus demonstrating its ability to deter multi-dose oral abuse

    ROLE OF CALCIUM AND NITRIC OXIDE SYNTHASE (NOS) IN BRAIN MITOCHONDRIAL DYSFUNCTION

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    Mitochondria are essential for promoting cell survival and growth through aerobic metabolism and energy production. Mitochondrial function is typically analyzed using mitochondria freshly isolated from tissues and cells because they yield tightly coupled mitochondria, whereas those from frozen tissue can consist of broken mitochondria and membrane fragments. A method, utilizing a well-characterized cryoprotectant such as dimethyl sulfoxide (DMSO), is described. Such mitochondria show preserved structure and function that presents us with a possible strategy to considerably expand the time-frame and the range of biochemical, molecular and metabolic studies that can be performed without the constraints of mitochondrial longevity ex vivo. Mitochondrial dysfunction is implicated in Alzheimer’s disease (AD) mainly through oxidative stress and altered metabolism. Mitochondria are isolated from post-mortem brain samples from selective regions of AD and control patients and, utilizing the cryopreservation strategy, analyzed for respiration and oxidative damage. While we did not observe increases in free radicals, we did observe decreased respiration and increases in oxidative damage markers in AD patients, suggesting a role for oxidative stress in mitochondrial dysfunction. While in the mitochondria, calcium (Ca2+) increases free radical generation by processes not completely understood. A new isoform of nitric oxide synthase (mtNOS) has been isolated and localized to mitochondria; though its existence and physiological role is debated. Nitric oxide synthase (NOS), when activated by Ca2+, produces nitric oxide (NO•) that can interact with ROS producing various reactive nitrogen species (RNS). These highly reactive radical species can damage DNA, proteins and lipids, ultimately resulting in cell death via apoptosis or necrosis. The current research is aimed at understanding the role of Ca2+ and NOS in oxidative stress leading to mitochondrial dysfunction. We observed a significant reduction in mitochondrial respiration with increasing doses of calcium. We also observed NOS enzyme activity and detected NOS protein in the purified mitochondrial fraction. Lastly, we were also able to show that Ca2+ increased the levels of free radicals and changes in oxidative damage markers. These results suggest the presence of NOS in mitochondria that could play a role in Ca2+ induced mitochondrial dysfunction and potentially leading to cell death as relevant to aging and neurodegenerative diseases

    Efficient finite element modeling of WT sections subjected to uniaxial tension

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    Present design specifications for statically loaded tension members do not consider the effects of connection eccentricity as it induces bending in statically loaded members. Previous experimental tests conducted at West Virginia University [WVU] have shown that connection eccentricity induced bending effects have the potential to significantly reduce the net section rupture capacity of a section.;The present study is focused on developing finite element tools capable of capturing the peak loads and behavioral response exhibited is the previous WVU experimental tests. The main objective of the finite element analysis is not only to estimate the failure loads of the WT section specimens but also to trace the entire load versus deflection path. For an accurate representation of the failure load it is essential to capture the underlying necking behavior in the vicinity of the lead bolthole. The finite element analysis is performed using 3D solid elements that are capable of representing large deformation geometric and material nonlinearities. The commercial finite element program ABAQUS is used to perform the analysis. (Abstract shortened by UMI.)
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