LLukas22/scidocs huggingface dataset:
Fracture and fatigue in graphene nanocomposites.

Graphene, a single-atom-thick sheet of sp-bonded carbon atoms, has generatedmuch interest due to its high specific area and novel mechanical, electrical, and thermal properties. Recent advances in the production of bulk quantities of exfoliated graphene sheets from graphite have enabled the fabrication of graphene–polymer composites. Such composites show tremendous potential for mechanical-property enhancement due to their combination of high specific surface area, strong nanofiller–matrix adhesion and the outstanding mechanical properties of the sp carbon bonding network in graphene. Graphene fillers have been successfully dispersed in poly(styrene), poly(acrylonitrile) and poly(methyl methacrylate) matrices and the responses of their Young’s modulus, ultimate tensile strength, andglass-transition temperaturehave been characterized. However, to the best of our knowledge there is no report on the fracture toughness and fatigue properties of graphene–polymer composites. Fracture toughness describes the ability of a material containing a crack to resist fracture and it is a critically important material property for design applications. Fatigue involves dynamic propagation of cracks under cyclic loading and it is one of the primary causes of catastrophic failure in structural materials. Consequently, the material’s resistance to fracture and fatigue crack propagation are of paramount importance to prevent failure. Herein we report the fracture toughness, fracture energy, and fatigue properties of an epoxy polymer reinforced with various weight fractions of functionalized graphene sheets. Remarkably, only 0.125% weight of functionalized graphene sheets was observed to increase the fracture toughness of the pristine (unfilled) epoxy by 65% and the fracture energy by 115%.Toachievecomparableenhancement,carbonnanotube (CNT) and nanoparticle epoxy composites require one to two orders of magnitude larger weight fraction of nanofillers. Under fatigue conditions, incorporation of 0.125% weight of functionalized graphene sheets drastically reduced the rate of crack propagation in the epoxy 25-fold. Fractography analysis
Suicide and friendships among American adolescents.

OBJECTIVES
We investigated the relationship between friendships and suicidality among male and female adolescents.


METHODS
We analyzed friendship data on 13,465 adolescents from the National Longitudinal Survey of Adolescent Health to explore the relationship between friendship and suicidal ideation and suicide attempts. We controlled for known factors associated with suicidality.


RESULTS
Having had a friend who committed suicide increased the likelihood of suicidal ideation and attempts for both boys and girls. Socially isolated females were more likely to have suicidal thoughts, as were females whose friends were not friends with each other. Among adolescents thinking about suicide, suicide attempts appear largely stochastic, with few consistent risk factors between boys and girls.


CONCLUSIONS
The friendship environment affects suicidality for both boys and girls. Female adolescents' suicidal thoughts are significantly increased by social isolation and friendship patterns in which friends were not friends with each other.
PREDATOR‐AVOIDANCE BEHAVIOR EXTENDS TROPHIC CASCADES TO REFUGE HABITATS

Consideration of how trait-mediated indirect interactions (TMIIs) affect community dynamics is recognized as an important focus for ecological research. Although these indirect effects have been shown to mediate trophic cascades in ecological communities, our understanding of how habitat refuge influences the strength and direction of cascading effects is limited. We examined whether or not oyster toadfish (top predator) affect mud crab (intermediate predator) foraging on juvenile hard clams (infaunal prey) in oyster reefs, a physically complex habitat that can provide refuge for both intermediate predators and basal prey. In particular, we manipulated toadfish presence in mesocosms containing experimental oyster reefs and quantified both mud crab and juvenile clam mortality. Toadfish significantly reduced mud crab foraging on clams and increased clam survivorship even though mud crabs foraging on the surface of the reef sought refuge from toadfish deeper within the oyster-shell matrix where they were more proximal to clams. This counterintuitive result suggests that toadfish suppression of mud crab foraging activity is far stronger than toadfish-avoidance behavior that potentially increases crab–clam encounter rates. Therefore, TMIIs can reinforce trophic cascades even in refuge habitats where intermediate predators and their prey are physically isolated from top predators. Determining the generality of cascading effects on lower trophic levels within refugia will require investigating how habitat refuge affects the relative importance of TMIIs.
In Vivo Molecular Imaging and Histological Analysis of Changes Induced by Electric Pulses Used for Plasmid DNA Electrotransfer to the Skin: A Study in a Dorsal Window Chamber in Mice

Electropermeabilization/electroporation (EP) is a physical method that by application of electric pulses to cells increases cell membrane permeability and enables the introduction of molecules into the cells. One of the uses of EP in vivo is plasmid DNA electrotransfer to the skin for DNA vaccination. EP of tissues induces reduction of blood flow and, in combination with plasmid DNA, induction of an immune response. One of the EP protocols for plasmid DNA electrotransfer to the skin is a combination of high-voltage (HV) and low-voltage (LV) pulses. However, the effects of this pulse combination on skin-vessel blood flow are not known. Therefore, using intravital microscopy in a dorsal window chamber in mice and fluorescently labeled dextrans, the effects of one HV and eight LV pulses on skin vasculature were investigated. In addition, a detailed histological analysis was performed. Image analysis of fluorescence intensity changes demonstrated that EP induces a transient constriction and increased permeability of blood vessels as well as a “vascular lock.” Histological analysis revealed rounding up of endothelial cells and stacking up of erythrocytes at 1 h after EP. In addition, extravasation of erythrocytes and leukocyte infiltration accompanied by edema were determined up to 24 h after EP. In conclusion, our results show that blood flow modifying effects of EP in skin contribute to the infiltration of immune cells in the exposed area. When combined with plasmid DNA for vaccination, this could enable the initial and prolonged contact of immune cells with encoded therapeutic proteins.
Modeling of hard part machining: effect of insert edge preparation in CBN cutting tools

High speed machining of hardened steels for manufacturing dies and molds offers various advantages, but the productivity often limited by mainly tool life. This study investigates the influence of edge preparation in cubic boron nitrite (CBN) cutting tools on process parameters and tool performance by utilizing practical finite element (FE) simulations and high speed orthogonal cutting tests. The predicted process parameters through FE simulations in high speed orthogonal cutting are expected to help optimize tool life and surface finish in hard machining of AISI H-13 hot work tool steel. A set of orthogonal cutting experiments using honed and chamfered CBN tools was performed and primary cutting force and thrust force were measured by using a force dynamometer along with a PC-based data acquisition system. The same set of cutting conditions was used in numerical FE simulations to predict forces, stresses and temperatures developed at the honed and chamfered CBN tools. Simulation results provided a distribution of stresses and temperatures at the cutting zone, chip–tool and workpiece– tool interfaces. Numerical simulations include testing different edge preparation geometry for CBN tools at different cutting speeds and feeds. The results show that a zone of workpiece material is formed under the chamfer acting as an effective rake angle during cutting. The presence of a chamfer affects the cutting forces and temperatures while no significant change in chip formation observed. # 2003 Elsevier Science B.V. All rights reserved.
Stud krill herd algorithm

Recently, Gandomi and Alavi proposed a meta-heuristic optimization algorithm, called Krill Herd (KH), for global optimization [Gandomi AH, Alavi AH. Krill Herd: A New Bio-Inspired Optimization Algorithm. Communications in Nonlinear Science and Numerical Simulation, 17(12), 4831–4845, 2012.]. This paper represents an optimization method to global optimization using a novel variant of KH. This method is called the Stud Krill Herd (SKH). Similar to genetic reproduction mechanisms added to KH method, an updated genetic reproduction schemes, called stud selection and crossover (SSC) operator, is introduced into the KH during the krill updating process dealing with numerical optimization problems. The introduced SSC operator is originated from original Stud genetic algorithm. In SSC operator, the best krill, the Stud, provides its optimal information for all the other individuals in the population using general genetic operators instead of stochastic selection. This approach appears to be well capable of solving various functions. Several problems are used to test the SKH method. In addition, the influence of the different crossover types on convergence and performance is carefully studied. Experimental results indicate an instructive addition to the portfolio of swarm intelligence techniques. & 2013 Elsevier B.V. All rights reserved.
Obstructive sleep apnea in Parkinson’s disease patients: effect of Sinemet CR taken at bedtime

Obstructive sleep apnea (OSA) results from upper airway (UA) obstruction. In Parkinson’s disease (PD), levodopa improves UA obstruction during wakefulness. We hypothesized that bedtime controlled-release levodopa (Sinemet CR) is associated with less severe OSA (lower apnea-hypopnea index [AHI]) in PD patients. Idiopathic PD subjects underwent nocturnal polysomnography (PSG) and were divided into those taking bedtime Sinemet CR (SinCR+) and those not taking Sinemet CR (SinCR−). Outcomes were compared between groups for PSG recordings analyzed in whole and split at their mid-point with each half analyzed separately, using linear regression. Fifty-seven subjects were studied, eight SinCR+, and 49 SinCR−. They were 65 % male, aged 64.4 ± 10.3 years (mean ± SD), with body mass index 27.26 ± 3.98 kg/m2. The whole night AHI was 15.6 ± 13.3 and 29.1 ± 20.8 in SinCR+ and SinCR−, respectively (p = 0.07 unadjusted, p = 0.11 adjusted for confounders). A similar trend was observed in the first half of the night. In the second half, the SinCR+ group had significantly lower AHI (beta = −18.8; p = 0.01 adjusted) and respiratory arousal index (beta = −14.2; p = 0.02 adjusted) than the SinCR− group. Bedtime Sinemet CR appears to reduce OSA in PD patients. There were no significant differences between groups in the first half of the night likely because of residual effects of short-acting levodopa in both groups, while Sinemet CR had residual effect in the second half. These results possibly provide an alternative to help manage OSA and improve sleep quality in PD patients.
Improving the Integration of Wind Power Generation Into AC Microgrids Using Flywheel Energy Storage

The connection of wind power generation into ac microgrids (MGs) is steadily increasing. This incorporation can bring problems onto the power quality and dynamics of the electrical grid due to the lack of controllability over the wind. In this work, a flywheel energy storage (FES) is used to mitigate problems introduced by wind generation into MGs. A dynamic model of the FES device is briefly presented and a technique to control the power exchanged between the device and the power system is proposed. The control technique has three modes, namely: voltage control (VC), frequency control (FC), and active power stabilization (APS). Simulation tests on the behavior of the FES device are analyzed when it works in combination with wind generation in the electrical microgrid. Results show an acceptable performance of the proposed control techniques along with a high effectiveness to smooth the active power fluctuations of wind generation.
Accessing an Information System by Chatting

In this paper, we describe a new way to access information by “chatting” to an information source. This involves a chatbot, a program that emulates human conversation; the chatbot must be trainable with a text, to accept input and match it against the text to generate replies in the conversation. We have developed a Machine Learning approach to retrain the ALICE chatbot with a transcript of human dialogue, and used this to develop a range of chatbots conversing in different styles and languages. We adapted this chatbot-training program to the Qur’an, to allow users to learn from the Qur’an in a conversational information-access style. The process and results are illustrated in this paper.
Efficacy of entecavir in chronic hepatitis B patients with mildly elevated alanine aminotransferase and biopsy-proven histological damage.

UNLABELLED
Current guidelines for management of chronic hepatitis B recommend treatment for patients presenting with elevated hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) >2 x upper limit of normal (ULN) or histological evidence of liver disease. Retrospective analyses have demonstrated that significant hepatic necroinflammation and fibrosis were present in a substantial proportion of patients with ALT 1 to 2 x ULN. To assess therapeutic efficacy in this clinical setting, we retrospectively examined treatment endpoints among the subset of nucleoside-naïve chronic hepatitis B (CHB) patients treated in phase 3 clinical trials of entecavir who had both screening and baseline serum ALT 1.3 to 2 x ULN. A total of 1347 patients were randomized to treatment with entecavir or lamivudine. Three hundred thirty-six patients, constituting 25% of the total study population, had screening and baseline ALT 1.3 to 2 x ULN. Clinically significant necroinflammation (Knodell necroinflammation score > or =7) was observed in 60% and 72% of hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients, respectively, whereas marked fibrosis (Ishak fibrosis score > or =4) was observed in 8% and 15% of HBeAg-positive and HBeAg-negative patients, respectively. Among entecavir-treated HBeAg-negative patients, the proportions of patients achieving histological improvement, HBV DNA <300 copies/mL, and ALT normalization were similar between patients with mildly elevated ALT and those with ALT >2 x ULN. However, entecavir-treated HBeAg-positive patients with mildly elevated ALT had lower response rates for histological improvement, HBV DNA less than 300 copies/mL, ALT normalization, and HBeAg seroconversion than those with ALT greater than 2 x ULN.


CONCLUSION
This retrospective analysis demonstrated that HBeAg-negative CHB patients treated with entecavir responded similarly irrespective of baseline ALT level. However, HBeAg-positive patients with mildly elevated ALT responded less well to treatment with entecavir than did those with ALT greater than 2 x ULN.
George Fort Milton and the Art of History.

HISTORIOGRAPHY is an often exciting branch of the discipline of history. The many splendid articles or books that have reviewed either a large body of work on a topic, a period, or say, even the works of one historian are not, at their best, either derivative scholarship or mere laundry lists of titles or ideas. Rather they have brought new understandings and insights as well as suggesting new paths of scholarship that only wide reading and seasoned thought could produce. Nevertheless, though historians discoursed endlessly in writing at the numerous professional meetings on each other's articles and books, only in recent years has there been sustained interest in how historians go about their daily task of teaching, an activity immensely enjoyed by most and one that supports the scholarly life of most historians wherever they work and live. But equally fascinating is how different historians actually practice the art of history and their thoughts about the difficult problems of writing good history. Talk to any colleague who has done so, or read the autobiography or biographies of great historians, and listen to the different techniques, styles, and tricks of the trade that come tumbling out, as well as insight into the interaction of the artist with the art. How George Fort Milton, who earned his keep as a newspaper publisher and editor, did history is especially interesting because his was a career different from that of the usual scholarteacher. Milton neither saw the inside of a graduate seminar room nor did he experience the red slash of a graduate professor's pen. But Milton, in the late 1920s through the mid-1940s, would write five history books, give numerous lectures with historical themes,
STAR: a dementia-specific training program for staff in assisted living residences.

PURPOSE
This article describes, and provides data on, an innovative, comprehensive, dementia-specific training program designed to teach direct care staff in assisted living residences to improve care and reduce problems in residents with dementia.


DESIGN AND METHODS
STAR-which stands for Staff Training in Assisted living Residences-provides two 4-hr workshops augmented by four individualized on-site consultations and three leadership sessions. Developed by means of an iterative process of implementation and revision, it was then evaluated in a small randomized controlled trial. A total of 114 staff and 120 residents in 15 residences participated.


RESULTS
STAR was exceptionally well received. Training details are provided with a discussion of unique challenges inherent in implementation. Following training, STAR residents evidenced significantly reduced levels of affective and behavioral distress compared with control residents. Furthermore, STAR residents improved whereas control residents worsened (p < .05). Staff with STAR staff training reported less adverse impact and reaction to residents' problems (p < .05) and more job satisfaction (p < .10) compared with control staff.


IMPLICATIONS
STAR is an effective training program for direct care staff working with dementia residents in assisted living. The importance of continued development and investigation of STAR efficacy and effectiveness is underscored by the growing numbers of residents with dementia who are receiving care in these settings.
Synchronization methods in parallel and distributed discrete-event simulation

This work attempts to provide insight into the problem of executing discrete event simulation in a distributed fashion. The article serves as the state of the art in Parallel DiscreteEvent Simulation (PDES) by surveying existing algorithms and analyzing the merits and drawbacks of various techniques. We discuss the main characteristics of existing synchronization methods for parallel and distributed discrete event simulation. The two major categories of synchronization protocols, namely conservative and optimistic, are introduced and various approaches within each category are presented. We also present the latest efforts towards PDES on emerging platforms such as heterogeneous multicore processors, Web services, as well as Grid and Cloud environment. 2012 Elsevier B.V. All rights reserved. 1. Parallel discrete-event simulation With the computing power and advanced software available today, modeling and simulation has become a cost-effective tool for detailed analysis of a broad array of natural and artificial systems. Parallel and distributed simulation is widely accepted as the technology of choice to speed up large-scale discrete-event simulation and to promote reusability and interoperability of simulation components. Parallel Discrete-Event Simulation (PDES) has received increasing interest as simulations become more time consuming and geographically distributed. A rich literature has already been developed in the last three decades, taking advantage of the increasing availability of highly parallel and distributed computing platforms. It has been several years since the last survey by Perumalla [5] and a refreshed review of the latest developments would be needed for us to ponder new research initiatives, especially on emerging platforms such as many-core processors, Internetscale simulation environments, and cloud-based virtualized infrastructures. In parallel and distributed simulations, the entire simulation task is divided into a set of smaller subtasks with each executed on a different processor or node. Hence, the simulation system is viewed as a collection of concurrent processes, each modeling a different part of the physical system and executing on a dedicated processor in a sequential fashion. These processes communicate with each other by exchanging time-stamped event messages. An event refers to an update to simulation system state at a specific simulation time instant. Throughout the simulation, events arrive at destination processes, and depending on the delivery ordering system of the simulation, they are processed differently. The two commonly used orderings are (1) receive-order and (2) timestamp-order. With the first type, events are delivered to the destination processes when they arrive at the destination. On the other hand, with the timestamp-order, events are delivered in non-decreasing order of their timestamp, requiring runtime checks and buffering to ensure such ordering. . All rights reserved. x: +1 613 520 5727.
Data Wrangling: Making data useful again

Data analysis has become an everyday business and advancements of data management routines open up new opportunities. Nevertheless, transforming and assembling newly acquired data into a suitable form remains tedious. It is often stated, that data cleaning is a critical part of the overall process, but also consumes sublime amounts of time and resources. Data Wrangling is not only about transforming and cleaning procedures. Many other aspects like data quality, merging of different sources, reproducible processes, and managing data provenance have to be considered. Although various tools designed for specific tasks are available, software solutions accompanying the whole process are still rare. In this paper, some aspects of this first phase of most data driven projects, also known as data wrangling, data munging or janitorial work are described. Beginning with an overview on the topic and current problems, concrete common tasks as well as selected software solutions and techniques are discussed.