A control theoretic analysis of oscillator Ising machines.

This work advances the understanding of oscillator Ising machines (OIMs) as a nonlinear dynamic system for solving computationally hard problems. Specifically, we classify the infinite number of all possible equilibrium points of an OIM, including non-0/π ones, into three types based on their structural stability properties. We then employ the stability analysis techniques from control theory to analyze the stability property of all possible equilibrium points and obtain the necessary and sufficient condition for their stability. As a result of these analytical results, we establish, for the first time, the threshold of the binarization in terms of the coupling strength and strength of the second harmonic signal. Furthermore, we provide an estimate of the domain of attraction of each asymptotically stable equilibrium point by employing the Lyapunov stability theory. Finally, we illustrate our theoretical conclusions by numerical simulation.

Evaluation of Inbred Maize (Zea mays L.) for Tolerance to Low Phosphorus at the Seedling Stage.

In underdeveloped nations where low-input agriculture is practiced, low phosphorus (LP) in the soil reduces the production of maize. In the present study, a total of 550 inbred maize lines were assessed for seedling traits under LP (2.5 × 10-6 mol L-1 of KH2PO4) and NP (2.5 × 10-4 mol L-1 of KH2PO4) hydroponic conditions. The purpose of this study was to quantify the amount of variation present in the measured traits, estimate the genetic involvement of these characteristics, examine the phenotypic correlation coefficients between traits, and to integrate this information to prepare a multi-trait selection index for LP tolerance in maize. A great deal of variability in the maize genotype panel was confirmed by descriptive statistics and analysis of variance (ANOVA). Estimated broad-sense heritability (h2) ranged from 0.7 to 0.91, indicating intermediate to high heritability values for the measured traits. A substantial connection between MSL and other root traits suggested that the direct selection of MSL (maximum shoot length) could be beneficial for the enhancement of other traits. The principal component analysis (PCA) of the first two main component axes explained approximately 81.27% of the variation between lines for the eight maize seedling variables. TDM (total dry matter), SDW (shoot dry weight), RDW (root dry weight), SFW (shoot fresh weight), RFW (root fresh weight), MRL (maximum root length), and MSL measurements accounted for the majority of the first principal component (59.35%). The multi-trait indices were calculated based on PCA using all the measured traits, and 30 genotypes were selected. These selected lines might be considered as the potential source for the improvement of LP tolerance in maize.

Designing Ising machines with higher order spin interactions and their application in solving combinatorial optimization.

The Ising model provides a natural mapping for many computationally hard combinatorial optimization problems (COPs). Consequently, dynamical system-inspired computing models and hardware platforms that minimize the Ising Hamiltonian, have recently been proposed as a potential candidate for solving COPs, with the promise of significant performance benefit. However, prior work on designing dynamical systems as Ising machines has primarily considered quadratic interactions among the nodes. Dynamical systems and models considering higher order interactions among the Ising spins remain largely unexplored, particularly for applications in computing. Therefore, in this work, we propose Ising spin-based dynamical systems that consider higher order (> 2) interactions among the Ising spins, which subsequently, enables us to develop computational models to directly solve many COPs that entail such higher order interactions (i.e., COPs on hypergraphs). Specifically, we demonstrate our approach by developing dynamical systems to compute the solution for the Boolean NAE-K-SAT (K ≥ 4) problem as well as solve the Max-K-Cut of a hypergraph. Our work advances the potential of the physics-inspired 'toolbox' for solving COPs.

Epidemio-toxicological profile of fatal poisoning cases autopsied at a tertiary care centre of North India.

Background: Poisoning is an important health hazard and one of the leading causes of morbidity and mortality worldwide including in India. The study was conducted to understand the magnitude, pattern, and gender differentials of all poisoning fatalities in relation to the manner of death autopsied at a tertiary care center. Methods: A retrospective study of all fatal poisoning cases autopsied at the department of Forensic Medicine & Toxicology of a tertiary care institute in Northern India for the period 1st January 1998 to 31st December 2017 was conducted, and a profile of the victims of fatal poisoning was prepared. Data were analyzed with descriptive and inferential statistics. Results: The study included a total of 1099 cases of fatal poisoning autopsied at the department of Forensic medicine & Toxicology. Suicidal poisoning was reported in 90.2% of cases and accidental poisoning was seen in 8.9% of cases. Males were predominantly affected (63.8%). The majority of the victims were in the 3rd decade (40.0%) of life. The age of the victims ranged from 2 to 82 years with a mean age of 38.4 years. Agrochemical compounds were implicated in 44.4% of the total fatalities. Conclusion: Males in the 2nd to 4th decades of life were more prone to self-poisoning with Agrochemical compounds in the region of North India. Accidental poisoning deaths were uncommon and poisoning was not a preferred method of homicide in this region. Our approach to the study reveals that quantitative chemical (toxicological) analysis is required to further strengthen and improve the databases of the epidemiology of poisoning in this region.

CMOS-compatible ising machines built using bistable latches coupled through ferroelectric transistor arrays.

Realizing compact and scalable Ising machines that are compatible with CMOS-process technology is crucial to the effectiveness and practicality of using such hardware platforms for accelerating computationally intractable problems. Besides the need for realizing compact Ising spins, the implementation of the coupling network, which describes the spin interaction, is also a potential bottleneck in the scalability of such platforms. Therefore, in this work, we propose an Ising machine platform that exploits the novel behavior of compact bi-stable CMOS-latches (cross-coupled inverters) as classical Ising spins interacting through highly scalable and CMOS-process compatible ferroelectric-HfO2-based Ferroelectric FETs (FeFETs) which act as coupling elements. We experimentally demonstrate the prototype building blocks of this system, and evaluate the scaling behavior of the system using simulations. Our work not only provides a pathway to realizing CMOS-compatible designs but also to overcoming their scaling challenges.

Demonstration of Efficient Ultrathin Side-Emitting InGaN/GaN Flip-Chip Light-Emitting Diodes by Double Side Reflectors.

This work proposes an InGaN/GaN multiple-quantum-well flip-chip blue ultrathin side-emitting (USE) light-emitting diode (LED) and describes the sidewall light emission characteristics for the application of backlight units in display technology. The USE-LEDs are fabricated with top (ITO/distributed Bragg reflector) and bottom (Ag) mirrors that cause light emission from the four sidewalls in a lateral direction. The effect of light output power (LOP) on lateral direction is consistently investigated for improving the optoelectronic performances of USE-LEDs. Initially, the reference USE-LED suffers from very low LOP because of poor light extraction efficiency (LEE). Therefore, the LEE is improved by fabricating ZnO nanorods at each sidewall through hydrothermal method. The effects of ZnO nanorod lengths and diameters on LOP are systematically investigated for optimizing the dimensions of ZnO nanorods. The optimized ZnO nanorods improve the LEE of USE-LED, which thus results in increasing the LOP > 80% compared to the reference LED. In addition, the light-tools simulator is also used for elucidating the increase in LEE of ZnO nanorods USE-LED.

32 × 32 Pixelated High-Power Flip-Chip Blue Micro-LED-on-HFET Arrays for Submarine Optical Communication.

This work proposes the use of integrated high-power InGaN/GaN multiple-quantum-well flip-chip blue micro light-emitting diode (µ-LED) arrays on an AlGaN/GaN-based heterojunction field-effect transistor (HFET), also known as a high electron mobility transistor (HEMT), for various applications: underwater wireless optical communication (UWOC) and smart lighting. Therefore, we demonstrate high-power µ-LED-on-HEMT arrays that consist of 32 × 32 pixelated µ-LED arrays and 32 × 32 pixelated HEMT arrays and that are interconnected by a solder bump bonding technique. Each pixel of the µ-LED arrays emits light in the HEMT on-state. The threshold voltage, the off-state leakage current, and the drain current of the HEMT arrays are -4.6 V, <~1.1 × 10-9 A at gate-to-source voltage (VGS) = -10 V, and 21 mA at VGS = 4 V, respectively. At 12 mA, the forward voltage and the light output power (LOP) of µ-LED arrays are ~4.05 V and ~3.5 mW, respectively. The LOP of the integrated µ-LED-on-HEMT arrays increases from 0 to ~4 mW as the VGS increases from -6 to 4 V at VDD = 10 V. Each pixel of the integrated µ-LEDs exhibits a modulated high LOP at a peak wavelength of ~450 nm, showing their potential as candidates for use in UWOC.

Progressive Genomic Approaches to Explore Drought- and Salt-Induced Oxidative Stress Responses in Plants under Changing Climate.

Drought and salinity are the major environmental abiotic stresses that negatively impact crop development and yield. To improve yields under abiotic stress conditions, drought- and salinity-tolerant crops are key to support world crop production and mitigate the demand of the growing world population. Nevertheless, plant responses to abiotic stresses are highly complex and controlled by networks of genetic and ecological factors that are the main targets of crop breeding programs. Several genomics strategies are employed to improve crop productivity under abiotic stress conditions, but traditional techniques are not sufficient to prevent stress-related losses in productivity. Within the last decade, modern genomics studies have advanced our capabilities of improving crop genetics, especially those traits relevant to abiotic stress management. This review provided updated and comprehensive knowledge concerning all possible combinations of advanced genomics tools and the gene regulatory network of reactive oxygen species homeostasis for the appropriate planning of future breeding programs, which will assist sustainable crop production under salinity and drought conditions.

Evaluation of Psychometric Properties of Hindi Versions of Geriatric Depression Scale and Patient Health Questionnaire in Older Adults.

BACKGROUND: A limited number of studies have evaluated the psychometric properties of rating scales used to assess depression in the older adults. The present study aimed to assess the validity of the Hindi Geriatric Depression Scale (GDS, 30, 15, 10, 5, 4, and 1 item version) and Hindi Patient Health Questionnaire (nine and two items version) in a group of older adults residing in a rural community. METHODS: The psychometric properties of these scales were assessed against the diagnosis of depression a qualified psychiatrist made by using a semistructured interview. RESULTS: Total 125 older adults were recruited from a rural community, with a mean age of 65.5 (SD: 6.4) years. The prevalence of depression was 36.8% as per the evaluation by the psychiatrist. When the agreement of different scales with the clinicians' diagnosis was evaluated, it was seen that sensitivity, specificity, and Cohen Kappa value of GDS-30 and 15 were better than the other scales used to assess depression. When the sensitivity and specificity were evaluated using newer cutoffs, the specificity and sensitivity of GDS-30 were more than that of other scales. CONCLUSION: Hindi version of GDS-30 with a cutoff of 13 has excellent psychometric properties.

Jojoba oil-based microemulsion for transdermal drug delivery.

BACKGROUND AND PURPOSE: Microemulsions are gaining an increased interest in transdermal drug delivery. Microemulsions are stable, easy to prepare, and provide high solubilizing capacity for various drugs. The aim of this work was to prepare microemulsions from jojoba oil for transdermal delivery of ketorolac and lidocaine HCl with improved permeation. EXPERIMENTAL APPROACH: Microemulsions based on jojoba oil as the oil phase were formulated for transdermal delivery of lidocaine HCl and ketorolac. Brij 97 was selected as surfactant and hexanol as cosurfactant. Pseudoternary phase diagrams were constructed. Selected microemulsion formulations were characterized for their physical properties and in vitro drug permeation. FINDINGS/RESULTS: Water-in-oil microemulsions were obtained with droplet sizes not more than 220 nm. The viscosity of the microemulsions was linked to the viscosity of the surfactant used. Improved drug permeation rates were observed for both model drugs. The significant increase in permeation rate in presence of hexanol was due to its impact on skin integrity as indicated by the histopathological study. Drug permeation enhancements were caused by the surfactant, the cosurfactant used, jojoba oil itself, and the microemulsion formulation. Higher surfactant content showed lower lag times and better flux. CONCLUSION AND IMPLICATIONS: Jojoba oil microemulsions are considered promising vehicles for transdermal delivery of ketorolac and lidocaine HCl with improved drug permeation. Jojoba oil-based microemulsion would present a safe and effective means for delivering drugs through the skin.

Tendencies and attitudes towards dietary supplements use among undergraduate female students in Bangladesh.

BACKGROUND: Dietary supplements (DS) are products that improve the overall health and well-being of individuals and reduce the risk of disease. Evidence indicates a rising prevalence of the use of these products worldwide especially among the age group 18-23 years. AIM: The study investigates the tendencies and attitudes of Bangladeshi undergraduate female students towards dietary supplements (DS). METHODS: A three-month (March 2018-May 2018) cross-sectional face-to-face survey was conducted in undergraduate female students in Chittagong, Bangladesh using a pre-validated dietary supplement questionnaire. The study was carried among the four private and three public university students of different disciplines in Chittagong to record their prevalent opinions and attitudes toward using DS. The results were documented and analyzed by SPSS version 22.0. RESULTS: Ninety two percent (N = 925, 92.0%) of the respondents answered the survey questions. The prevalence of DS use was high in undergraduate female students. The respondents cited general health and well-being (n = 102, 11.0%) and physician recommendation (n = 101, 10.9%) as a reason for DS use. Majority of the students (n = 817, 88.3%) used DS cost monthly between USD 0.12 and USD 5.90. Most of the students (n = 749, 81.0%) agreed on the beneficial effect of DS and a significant portion (n = 493, 53.3%) recommended for a regular use of DS. Highly prevalent use of dietary supplements appeared in Chittagonian undergraduate female students. They were tremendously positive in using DS. The results demonstrate an increasing trend of using DS by the undergraduate females for both nutritional improvement and amelioration from diseases. CONCLUSION: Dietary supplements prevalence was so much higher in students of private universities as compared to students of public universities. Likewise, maximal prevalence is indicated in pharmacy department compared to other departments. Students preferred brand products, had positive opinions and attitudes towards dietary supplements.

Using noise to augment synchronization among oscillators.

Noise is expected to play an important role in the dynamics of analog systems such as coupled oscillators which have recently been explored as a hardware platform for application in computing. In this work, we experimentally investigate the effect of noise on the synchronization of relaxation oscillators and their computational properties. Specifically, in contrast to its typically expected adverse effect, we first demonstrate that a common white noise input induces frequency locking among uncoupled oscillators. Experiments show that the minimum noise voltage required to induce frequency locking increases linearly with the amplitude of the oscillator output whereas it decreases with increasing number of oscillators. Further, our work reveals that in a coupled system of oscillators-relevant to solving computational problems such as graph coloring, the injection of white noise helps reduce the minimum required capacitive coupling strength. With the injection of noise, the coupled system demonstrates frequency locking along with the desired phase-based computational properties at 5 × lower coupling strength than that required when no external noise is introduced. Consequently, this can reduce the footprint of the coupling element and the corresponding area-intensive coupling architecture. Our work shows that noise can be utilized as an effective knob to optimize the implementation of coupled oscillator-based computing platforms.

Using synchronized oscillators to compute the maximum independent set.

Not all computing problems are created equal. The inherent complexity of processing certain classes of problems using digital computers has inspired the exploration of alternate computing paradigms. Coupled oscillators exhibiting rich spatio-temporal dynamics have been proposed for solving hard optimization problems. However, the physical implementation of such systems has been constrained to small prototypes. Consequently, the computational properties of this paradigm remain inadequately explored. Here, we demonstrate an integrated circuit of thirty oscillators with highly reconfigurable coupling to compute optimal/near-optimal solutions to the archetypally hard Maximum Independent Set problem with over 90% accuracy. This platform uniquely enables us to characterize the dynamical and computational properties of this hardware approach. We show that the Maximum Independent Set is more challenging to compute in sparser graphs than in denser ones. Finally, using simulations we evaluate the scalability of the proposed approach. Our work marks an important step towards enabling application-specific analog computing platforms to solve computationally hard problems.

Overcoming the health system barriers to early diagnosis and management of multidrug-resistant tuberculosis in a rural setting in North India.

India contributes a quarter of the global burden of multidrug-resistant tuberculosis (MDR-TB) and has inadequate diagnostic infrastructure and institutional capacities for drug susceptibility testing. Subsequently, this leads to a large number of undetected and untreated cases of MDR-TB. In this report, we describe a case of a 55-year-old man from rural North India presenting with complaints of continued symptoms of chronic cough, fever and dyspnoea despite being recently diagnosed with recurrent tuberculosis and receiving treatment from the local community health centre. MDR-TB was suspected, but confirmatory diagnostic capabilities were not available in the local setting. The patient was finally diagnosed with MDR-TB. Treatment was coordinated by the district tuberculosis programme officer. Through this case, we describe the various barriers to detecting MDR-TB in the rural regions of India. Prompt identification of patients with presumptive MDR-TB, diagnosis of the disease and initiation of treatment are crucial to preventing disease transmission and reducing morbidity and mortality.

Monitoring Silane Sol-Gel Kinetics with In-Situ Optical Turbidity Scanning and Dynamic Light Scattering.

Organosilanes (e.g., R'-SiOR3) provide hydrophobic functionality in thin-film coatings, porous gels, and particles. Compared with tetraalkoxysilanes (SiOR4), organosilanes exhibit distinct reaction kinetics and assembly mechanisms arising from steric and electronic properties of the R' group on the silicon atom. Here, the hydrolysis and condensation pathways of n-propyltrimethoxy silane (nPM) and a tri-fluorinated analog of nPM, 3,3,3-trifluoropropyl trimethoxy silane (3F), were investigated under aqueous conditions at pH 1.7, 2.0, 3.0, and 4.0. Prior to hydrolysis, 3F and nPM are insoluble in water and form a lens at the bottom (3F) or top (nPM) of the solutions. This phase separation was employed to follow reaction kinetics using a Turbiscan instrument to monitor hydrolysis through solubilization of the neat silane lens while simultaneously tracking condensation-induced turbidity throughout the bulk solution. Dynamic light scattering confirmed the silane condensation and particle aggregation processes reported by the turbidity scanning. Employing macroscopic phase separation of the starting reactants from the solvent further allows for control over the reaction kinetics, as the interfacial area can be readily controlled by reaction vessel geometry, namely by controlling the surface area to volume. In-situ turbidity scanning and dynamic light scattering revealed distinct reaction kinetics for nPM and 3F, attributable to the electron withdrawing and donating nature of the fluoro- and organo-side chains of 3F and nPM, respectively.

Microwave Assisted Sol-Gel Synthesis of Silica-Spider Silk Composites.

This study introduces a simple and environmentally friendly method to synthesize silica-protein nanocomposite materials using microwave energy to solubilize hydrophobic protein in an aqueous solution of pre-hydrolyzed organo- or fluoro-silane. Sol-gel functionality can be enhanced through biomacromolecule incorporation to tune mechanical properties, surface energy, and biocompatibility. Here, synthetic spider silk protein and organo- and fluoro-silane precursors were dissolved and mixed in weakly acidic aqueous solution using microwave technology. Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) images revealed the formation of spherical nanoparticles with sizes ranging from 100 to 500 nm depending, in part, on silane fluoro- or organo-side chain chemistry. The silane-protein interaction in the nanocomposite was assessed through infrared spectroscopy. Deconvoluted ATR-FTIR (Attenuated total reflectance Fourier-transform infrared spectroscopy) spectra revealed silane chemistry-specific conformational changes in the protein-silane nanocomposites. Relative to microwave-solubilized spider silk protein, the ß structure content increased by 14% in the spider silk-organo-silica nanocomposites, but decreased by a net 20% in the spider silk-fluoro-silica nanocomposites. Methods of tuning the secondary structures, and in particular ß-sheets that are the cross-linking moieties in spider silks and other self-assembling fibrillar proteins, may provide a unique means to promote protein interactions, favor subsequent epitaxial growth process, and enhance the properties of the protein-silane nanocomposites.

Prevalence of Elder Abuse and its Association with Psychiatric Morbidity in a Rural Setting.

AIM: The aim of this study was to evaluate the prevalence of elder abuse in a rural setting. In addition, the study aimed to evaluate the association of elder abuse with psychiatric morbidity and demographic factors. METHODOLOGY: A total of 125 elderly (age ≥55 years) were evaluated for psychiatric diagnosis as per the International Classification of Diseases, 10th revision (ICD-10) criteria by the qualified psychiatrist and were evaluated on Vulnerability to Abuse Screening Scale for elder abuse. RESULTS: More than half (58.4%) of the participants had one psychiatric disorder, with depression being the most common. Elder abuse was seen in more than one-third (41.6%) of the study participants. Those with psychiatric morbidity had significantly higher prevalence of abuse. None of the demographic factors was associated with abuse. CONCLUSION: Elder abuse is highly prevalent in rural setting, especially among those with psychiatric morbidity. IMPLICATIONS: Considering the high prevalence of elder abuse, there is an urgent need to address the problem. Public awareness, education, and sensitization of people toward the abuse are need of the day.

Optoelectronic Performance Variations in InGaN/GaN Multiple-Quantum-Well Light-Emitting Diodes: Effects of Potential Fluctuation.

We investigate the cause of the optoelectronic performance variations in InGaN/GaN multiple-quantum-well blue light-emitting diodes, using three different samples from an identical wafer grown on a c-plane sapphire substrate. Various macroscopic measurements have been conducted, revealing that with increasing strain in the quantum wells (QWs), the crystal quality improves with an increasing peak internal quantum efficiency while the droop becomes more severe. We propose to explain these variations using a model where the in-plane local potential fluctuation in QWs is considered. Our work is contrasted with prior works in that macroscopic measurements are utilized to find clues on the microscopic changes and their impacts on the device performances, which has been rarely attempted.

So near, yet so far: access to safe abortion services remains elusive for poor women in India.

In this case study, we describe our experiences with a woman employed as a housemaid who sought unsafe abortion services from a private doctor. This was her sixth pregnancy, after previously giving birth to one son and two daughters and undergoing two induced abortions. Her husband remained opposed to the use of contraception. Initially, she had sought medical termination of pregnancy through a government hospital but was denied because of procedural delays, specifically the non-availability of an ultrasonography report consequent to a lack of proof of identity (ie, the AADHAAR card, a unique identification card for recording biometric and demographic data in India). She finally sought the services of an unqualified private physician and received oral abortifacient agents. Consequently, she was required to seek treatment for bleeding per vaginum from the dispensary staff at a government hospital. We note that many such incidents occur in our daily practice but remain unnoticed and undocumented. Although this patient was eligible for sterilisation (ie, tubectomy), her husband was uncooperative. This case illustrates the lack of decision-making power experienced by Indian women who have a low societal status.