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As the problem of drug abuse intensifies in the U.S., many studies that primarily utilize social media data, such as postings on Twitter, to study drug abuse-related activities use machine learning as a powerful tool for text classification and filtering. However, given the wide range of topics of Twitter users, tweets related to drug abuse are rare in most of the datasets. This imbalanced data remains a major issue in building effective tweet classifiers, and is especially obvious for studies that include abuse-related slang terms. In this study, we approach this problem by designing an ensemble deep learning model that leverages both word-level and character-level features to classify abuse-related tweets. Experiments are reported on a Twitter dataset, where we can configure the percentages of the two classes (abuse vs. non abuse) to simulate the data imbalance with different amplitudes. Results show that our ensemble deep learning models exhibit better performance than ensembles of traditional machine learning models, especially on heavily imbalanced datasets.

BACKGROUND The development and use of mobile health (mHealth) apps for asthma management have risen dramatically over the past two decades. Asthma apps vary widely in their content and features; however, prior research has rarely examined preferences of users of publicly available apps. OBJECTIVE The goals of this study were to provide a descriptive overview of asthma mobile apps that are publicly available and to assess the usability of asthma apps currently available on the market to identify content and features of apps associated with positive and negative user ratings. METHODS Reviews were collected on June 23, 2020, and included publicly posted reviews until June 21, 2020. To characterize features associated with high or low app ratings, we first dichotomized the average user rating of the asthma app into 2 categories: a high average rating and a low average rating. Asthma apps with average ratings of 4 and above were categorized as having a high average rating. Asthma apps with average ratings of less than 4 were categorized as having a low average rating. For the sentiment analysis, we modeled both 2-word (bi-gram) and 3-word (tri-gram) phrases which commonly appeared across highly rated and lowly rated apps. RESULTS Of the 10 apps that met the inclusion criteria, a total of 373 reviews were examined across all apps. Among apps reviewed, 53.4% (199/373) received high ratings (average ratings of 4 or 5) and 47.2% (176/373) received low ratings (average ratings of 3 or less). The number of ratings across all apps ranged from 188 (AsthmaMD) to 10 (My Asthma App); 30% (3/10) of apps were available on both Android and iOS. From the sentiment analysis, key features of asthma management that were common among highly rated apps included the tracking of peak flow readings (n=48), asthma symptom monitoring (n=11), and action plans (n=10). Key features related to functionality that were common among highly rated apps included ease of use (n=5). Users most commonly reported loss of data (n=14) and crashing of app (n=12) as functionality issues among poorly rated asthma apps. CONCLUSIONS Our study results demonstrate that asthma app quality, maintenance, and updates vary widely across apps and platforms. These findings may call into question the long-term engagement with asthma apps, a crucial factor for determining their potential to improve asthma self-management and asthma clinical outcomes.

In this paper, a nonlinear adaptive control of a 3D overhead crane is investigated. A dynamic model of the overhead crane was developed, where the crane system is assumed as a lumped mass model. Under the mutual effects of the sway motions of the payload and the hoisting motion, the nonlinear behavior of the crane system is considered. A nonlinear control model-based scheme was designed to achieve the three objectives: (i) drive the crane system to the desired positions, (ii) suppresses the vibrations of the payload, and (iii) velocity tracking of hoisting motion. The nonlinear control scheme employs adaptation laws that estimate unknown system parameters, friction forces and the mass of the payload. The estimated values were used to compute control forces applied to the trolley of the crane. The asymptotic stability of the crane system is investigated by using the Lyapunov method. The effectiveness of the proposed control scheme is verified by numerical simulation results.

The strain-compensation (SC) technique to reduce the accumulation of strain is a promising approach to increase the design flexibility as well as the performance of quantum dot (QD) lasers. Here we have studied the application of tensile-strained ultra-thin GaP layers into multiple stacked InAs/GaAs QD grown by MBE. XRD analysis shows the controllability of the average strain in multiple-stacked QD active layer, revealing a reduction in accumulated strain. Fabricated QD laser diodes including thinner QD active layers realized by SC technology show a narrower vertical far-field angle and an increased small signal modulation bandwidth without loss of gain. Cross-sectional SEM image of SC-QD LD active region

We present a novel structure of GaAsP nano apertures realized by employing the in situ thermal diffusion of phosphorus during epitaxial growth on top of quantum dot layers. Such structures may have direct device-oriented applications for the selective injection of electrical current into the dots. AFM and cross-sectional SEM images reveal that we are able to create elongated apertures in a diffusion layer of GaAsP by introducing a phosphorus flux during the growth, and that the apertures naturally form directly above the underlying dots. We also find that these nanoscale apertures are formed only when the distance between the top of the quantum dots and the diffusion layer is small enough, indicating that the aperture formation is due to the local strain field induced by the dots themselves. Schematic illustration of InAs/GaAs quantum dot layers and GaAsP nano-apertures.

A cell-based three-node triangular flat shell element with a bubble node is introduced to analyze frequencies of plates and shells. By smoothing the in-plane strains on sub-triangular domains created by connecting the bubble node to element nodes and applying the divergence theorem to derivatives in the gradient matrices, the integration of corresponding stiffness matrices are transformed from surface to line integrals. To remove the shear locking, the MITC3+ technique for three-node triangular degenerated shell elements with a bubble node is employed. The Craig-Bampton (CB) and enhanced Craig-Bampton (ECB) methods, which are well-known reduced-order modeling techniques based on substructuring strategy, are used for efficiently solving frequency analyses. Numerical results demonstrate the reliability and superiority of the present element, called CS-MITC3+, when combined with the substructuring methods to compute frequencies of plate and shell structures.

A highly X-ray-transparent, silicon nitride-based device has been designed and fabricated to harvest protein microcrystals for high-resolution X-ray diffraction data collection using microfocus beamlines and XFELs., Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (

We fabricated a two dimensional photonic crystal nanocavity embedding a spatially-isolated active region containing InAs quantum dots using crystal regrowth with molecular beam epitaxy. We observed a cavity mode with a quality factor over 10,000, despite the existence of a mound structure on top of the buried active region due to faceting during the regrowth.

As VLSI technology scales to deep sub-micron, design for interconnections becomes increasingly challenging. The traditional bus routing follows a sequential bit-by-bit order, and few works explicitly target inter-bit regularity for signal groups via multi-layer topology selection. To overcome these limitations, we present Streak, an efficient framework that combines topology generation and wire synthesis with a global view of optimization and constrained metal layer track resource allocation. In the framework, an identification stage decomposes binding groups into a set of representative objects; with the generated backbones, equivalent topologies are accompanied by the bits in every object; then a formulation guides the routing considering wire congestion and design regularity. Experimental results using industrial benchmarks demonstrate the effectiveness of the proposed technique.

Reducing static random-access memory (SRAM) operational voltage (Vmin) can greatly improve energy efficiency, yet SRAM Vmin does not scale with technology due to increased process variability. Assist techniques have been shown to improve the operation of SRAM, but previous investigations of assist techniques at design time have either relied on static metrics that do not account for important transient effects or make specific assumptions about failure distributions. This paper uses importance sampling of dynamic failure metrics to quantify and analyze the effect of different assist techniques, array organization, and timing on Vmin at design time. This approach demonstrates that the most effective technique for reducing SRAM Vmin is the negative bitline write assist, resulting in a Vmin of 600 mV for a 28-nm LP process in the typical corner.

We report on high speed InAs/GaAs quantum dot lasers at 1.3 µm range. Small signal modulation response measurement for fabricated ridge laser exhibited record high maximum 3 dB bandwidth of 13.1 and 8.8 GHz at 25 and 85°C, respectively as 1.3 µm-range QD lasers. We adopted higher QD density not only to increase differential gain but also to reduce the barrier thickness in between QD layers to 30 nm. A higher QD density enables to minimize the local strain above QDs because of strain overlapping from neighboring dots, resulting in suppressing vertical alignment just above embed dot even with thinner barrier layer. This approach contributes to reduce carrier capture time in active region with increasing gain and differential gain in multiple-stacked QD active layers.

Background Primary health care facilities frequently manage dengue cases on an ambulatory basis for the duration of the patient’s illness. There is a great opportunity for specific messaging, aimed to reduce dengue virus (DENV) transmission in and around the home, to be directly targeted toward this high-risk ambulatory patient group, as part of an integrated approach to dengue management. The extent however, to which physicians understand, and can themselves effectively communicate strategies to stop focal DENV transmission around an ambulatory dengue case is unknown; the matter of patient comprehension and recollection then ensues. In addition, the effectiveness of N,N-diethyl-3-methylbenzamide (DEET)-based insect repellent in protecting dengue patients from Aedes aegypti mosquitoes’ bites has not been investigated. Methodology A knowledge, attitude and practice (KAP) survey, focusing on the mechanisms of DENV transmission and prevention, was performed using semi-structured questionnaires. This survey was targeted towards the patients and family members providing supportive care, and physicians routinely involved in dengue patient management in Southern Vietnam. An additional clinical observational study was conducted to measure the efficacy of a widely-used 13% DEET-based insect repellent to repel Ae. aegypti mosquitoes from the forearms of dengue cases and matched healthy controls. Principal Findings Among both the physician (n = 50) and patient (n = 49) groups there were several respondents lacking a coherent understanding of DENV transmission, leading to some inappropriate attitudes and inadequate acute preventive practices in the household. The application of insect repellent to protect patients and their relatives from mosquito bites was frequently recommended by majority of physicians (78%) participating in the survey. Nevertheless, our tested topical application of 13% DEET conferred only ~1hr median protection time from Ae. aegypti landing. This is notably shorter than that advertised on the manufacturer’s label. No differences in landing time between febrile dengue cases or matched healthy controls (n = 19 experiments) were observed. Conclusion/Significance Our study identifies missed opportunities for primary care physicians to improve public health through communication of strategies that could prevent focal dengue transmission in and around a case household. We advocate better access to more efficient communication methods for physicians and auxilliary health workers, supporting to educate those at high risk of DENV transmission. Our empirical testing of a widely-available 13% DEET-based repellent was limited in its protective efficacy against Ae. aegypti mosquito bites, and therefore DENV transmission, suggesting more frequent application is necessary to be beneficial., Author Summary In endemic countries many dengue cases are managed on an ambulatory basis throughout their illness. Many of these ambulatory cases will be infectious to Ae. aegypti mosquitoes for some period of the febrile phase. A survey of two key actors, physicians who manage dengue cases and the primary caregiver to dengue cases, was performed to assess their knowledge, attitudes and practices on the mechanism of DENV transmission and prevention. In addition, the duration of protection from mosquito landing was measured and compared between febrile dengue patients and healthy volunteers using a locally available, and widely-used 13% N,N-Diethyl-3-methylbenzamide (DEET)-based topical insect repellent. This KAP survey demonstrated an incomplete understanding of DENV transmission among several patients and physicians, leading to some inappropriate attitudes and inadequate preventive practices in the household. This suggests that aspects of the knowledge, communication between physicians and patients about dengue, and what patients have retained from the clinical consultation, can be improved. The use of topical insect repellent to protect patients and relatives from mosquito bites was recommended by a large proportion of physicians. However, the repellent used in this experiment provided only a modest repellent effect to Ae. aegypti mosquitoes, with no difference in protection time when applied to either dengue patients or healthy controls. Future recommendations to patients should continue to promote repellent use, but advocate much more frequent application. To directly target those patients at risk of onward DENV transmission, this research highlights the potential benefits of physicians imparting practicable and effective advice on preventive measures of dengue case management, as part of a holistic approach to dengue control. Finally, findings of this work can provide data for approaching effectively preventive practices for DENV and other flaviviruses transmitted by Aedes spp.

We demonstrate two dimensional photonic crystal nanocavities embedding spatially-isolated active regions containing InAs/GaAs self-assembled quantum dots. We fabricated the GaAs-based structures by a combination of electron-beam lithography, dry/wet etching and crystal regrowth using molecular beam epitaxy. The fabricated nanocavity based on a photonic crystal double heterostructure supports a cavity mode with a high experimental quality factor over 10,000, despite the existence of a mound structure on the nanocavity formed during the regrowth. Using electromagnetic simulations, we discuss the origin of the cavity mode and a direction for further increasing the quality factor. The two dimensional photonic crystal nanocavities with buried quantum dot active regions will provide a useful platform for developing high performance nanolasers.

MicroRNAs (miRNAs or miRs) are a class of evolutionary conserved small non-coding RNAs that act as post-transcriptional regulators of gene expression. A wide number of studies has shown that the aberrant expression of miRNAs could be responsible for initiation and development of human cancers. Most of these deregulated miRNAs are overexpressed, thus being oncogenic. For these reasons, the inhibition of oncogenic miRNAs function or production would be a very promising approach for the development of new anticancer therapies [1]. The purpose of this work is the discovery of small-molecule drugs targeting the precursors of specific oncogenic miRNAs thus modulating their production. We have focused our attention on miRNA-372 and miRNA- 373 that are implicated in various cancers. For example, these two oncogenics (pre-miRNAs 372 and pre-miRNAs 373): two stem-loop structured RNAs that lead to mature miRNAs after cleavage by the enzyme Dicer. In the aim of inhibiting this biogenesis step and based on our previous works [2], we synthesized a novel series of RNA ligands composed of two different domains: (i) 2-deoxystreptamine (2-DOS) known as RNA-interacting group due to its role as a central scaffold of any known aminoglycosides [3] and (ii) aromatic or heteroaromatic groups that should improve affinity and selectivity of these ligands for the targeted RNAs. These two domains have been conjugated through carbamate, triazole and ether bonds in order to develop a simple and straightforward synthetic methodology and obtain a large number of diversified compounds. We obtained a library of 16 compounds which will be evaluated in vitro in order to identify the strongest RNA ligands that could be able to inhibit the production of the targeted oncogenic miRNAs and eventually lead to the inhibition of cancer cells proliferation.

Background Rituximab is a monoclonal antibody directed at CD20 positive B-lymphocytes and a potential therapeutic option in the treatment of multiple sclerosis. The safety of recurrent dosing is not established. Objectives The objective of this work was to report the experience of long-term rituximab administration in a comprehensive multiple sclerosis care clinic. Methods This was a single-center retrospective observational analysis of patients receiving rituximab for the treatment of multiple sclerosis from 2004 to 2015. Different dosing regimens were reviewed to determine whether frequency or dose may affect safety. CD19 and CD20 counts were collected to evaluate B-cell suppression during therapy. Relapses, magnetic resonance imaging activity and rituximab-related adverse events were collected by chart review and prospective database entry. Results Of 107 patients included, the average duration of treatment was 33.2 months. Seventy-seven patients received recurrent rituximab dosing after initiation. CD19/20 reconstitution occurred in approximately 20% of patients at 6 months, regardless of dosing strategy. Despite CD19/20 counts of 0, three patients had relapses or magnetic resonance imaging activity. Mostly mild side effects in relation to therapy were seen, with the exception of three patients requiring hospitalization for urinary tract infections. Conclusions In our clinic population, rituximab was well tolerated and safe with recurrent administration.

In this paper we introduce Chisel, a new hardware construction language that supports advanced hardware design using highly parameterized generators and layered domain-specific hardware languages. By embedding Chisel in the Scala programming language, we raise the level of hardware design abstraction by providing concepts including object orientation, functional programming, parameterized types, and type inference. Chisel can generate a high-speed C++-based cycle-accurate software simulator, or low-level Verilog designed to map to either FPGAs or to a standard ASIC flow for synthesis. This paper presents Chisel, its embedding in Scala, hardware examples, and results for C++ simulation, Verilog emulation and ASIC synthesis.

In this document, we report our activities on the subcontract with Kitware where we carefully study the upcoming ITK v4 pipeline design to help the ITK v4 development team to add support of modern dataflow architectures to ITK.

Fast acquisition and high axial resolution are two primary requirements for three-dimensional microscopy. However, they are sometimes conflicting: imaging modalities such as confocal imaging can deliver superior resolution at the expense of sequential acquisition at different axial planes, which is a time-consuming process. Optical scanning holography (OSH) promises to deliver a good trade-off between these two goals. With just a single scan, we can capture the entire three-dimensional volume in a digital hologram; the data can then be processed to obtain the individual sections. An accurate modeling of the imaging system is key to devising an appropriate image reconstruction algorithm, especially for real data where random noise and other imaging imperfections must be taken into account. In this paper we demonstrate sectional image reconstruction by applying an inverse imaging sectioning technique to experimental OSH data of biological specimens and visualizing the sections using the OSA Interactive Science Publishing software. (C) 2009 Optical Society of America

By using 15N techniques, the effect of Ca levels and some fertilizer application formulas on yield, N2 fixation and residual benefit by peanut (Arachis hypogaea L.) were examined on grey degraded soil in Vietnam. At an optimum Ca rate of 213 kg Ca ha-1, the highest values for the following parameters were obtained; seed yield — 1.47 ton ha-1 (increased 111% over the control treatment without Ca); N2 fixation — 101 kg N ha-1 (increased 197%); residual benefit — +31 kg N ha-1. Different fertiliser formulas have also effected the yield, N2 fixation and residual benefit to peanut. Of all the treatments, the new fertiliser plus 600 kg coconut ash treatment resulted in the highest yield, N2 fixation and residual benefit. With this treatment, the seed yield was 1331 kg ha-1 (increased 61%), N2 fixation was 103 kg N ha-1 (increased 81%) and residual benefit was +39 kg N ha-1.