bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of printed circuit board components placement
Authors: Purwanto R E , Sulistyono  , Mandayatma E
Published: February 2021

In order to optimize the throughput rate of these automatic systems, the time taken for the pick and place electronic components for each board has to be minimized. This study focused on optimization problems faced in automated assembly of electronic component in Printed Circuit Board (PCB). Components are placed on PCB where the process of pick-up and placement occurs starting from the machines to pick up the components from the feeder magazine. The number of components to be picked and placed maximum four components, depending on its contribution to minimize tour distance. Increased complexity of PCB assemblies, components and shorter product obsolescence timescales implies machines utilization must be maximized in order to achieve cost efficiencies. The difference in size and shape of components is handled by the head, which brings the optimization problem closer to real machine situation. In hope that the electro-pneumatic arm design can speed up the working time of installing components on the PCB and can add new designs to be registered for patents.
Application of the cascade system to increase the capacity of a pico-hydro power generation
Authors: Hidayat M N , Ronilaya F , Eryk I H , Setiawan A , Rohadi E
Published: February 2021

The Pico-hydro power generation is a power plant with a scale below 5 kW. This type of power generation is suitable for areas with streams or rivers with low water levels. One area that has natural conditions like this is the Javan Langur Centre (JLC), a rehabilitation facility for one of the endangered primate species, the langur. To support the operation of JLC, a pico-hydro power plant has been built, which has a capacity of 300 watts. However, due to the water discharge is quite low, the efficiency of the generator is less than 10%, of which, the total output power from the pico-hydro generator is about 27,3 watts. While the electrical energy requirements in JLC is around 50 watts for lighting. To meet the shortage of electricity supply, it is necessary to increase the power generated by the existing pico-hydro power plant, i.e. by applying a cascade system. This system utilizes water from the existing pico-hydro power plant drainage channel as the intake flow for the new pico-hydro power plant. This system also utilizes differences in elevation or water level to make the terraces. With the application of the cascade pico-hydro system, the electrical power requirements at JLC can be met.
Design generator of magnetic power (Based on gap rotor-stator motor magnet)
Authors: Susilo S H , Jannah Z , Kasijanto K , Adiwidodo S
Published: February 2021

The paper discusses magnetic power generators; if a conductor moves across the magnetic field, a voltage difference will occur at the ends of the conductors. The voltage rises as it approaches the area and vice versa, so electricity arises in cycles: positive - zero - negative - zero. In this study utilizing the rotation of a magnetic motor caused by the unbalance repulsive force between magnets. The design of the tool starts with designing a generator model that will be made. The design of generators is based on calculations obtained through the reference of generator design. The generator design uses magnets instead of anchor coils on the rotor (source of magnetic flux) and copper wire coils as anchor coils on the stator. This design considers rotor and stator parameters, including the distance between magnets, rotor diameter, rotor plate thickness, area of a magnetic area, number of stator coils, number of stator windings, and stator coil dimensions, and calculate generator output power. Tool testing is done to obtain data from tools that have been made. In testing the comparison of the results obtained from the study of the target to be achieved, if the results have not yet reached the target, then improvements are made to the results obtained as expected. Tests were carried out with no load and burden. The results showed that the rotor speed in the generator design could be achieved by determining the number of rotor poles, the generator voltage is influenced by the flux density produced by permanent magnets and the number of stator windings.
Low-cost Transverse Electromagnetic (TEM) cell design for radiated emission measurement
Authors: Hariyawan M Y , Darwis R S , Habibi B A
Published: February 2021

The increasing use of electronic and electrical equipment that continuously emits radiated emissions in the industrial, military, communications, household, and medical fields has increased dramatically over the past few decades. Radiated emission can interfere performance of other electronic devices around it. There is a demand for electric devices to comply with electromagnetic compatibility (EMC) standards before being marketed, requiring manufacturers to carry out EMC testing before devices enter the market. Transverse Electromagnetic (TEM) cells are usually used by designers to ensure that electronic devices comply with EMC standards. TEM cells for radiated emission measurement are widely used because they are cheap and time-saving before full compliance testing is carried out, which expensive for one-time screening. The main problems of commercial open TEM cells are relatively high price, weight, handling problems and portability. In this study, low-cost TEM cells were designed that could be used to test radiated emission generated by electronic devices. The fabricated TEM cells can operate up to 960 MHz and it can be used to test radiated emission generated from small electronic devices. It has better performance and more sensitive than branded TEM cells in the radiated emission test of a mobile phone.
Optimisation solar and wind hybrid energy for model catamaran ship
Authors: Setiawan B , Putra E S , Siradjuddin I , Junus M
Published: February 2021

Based on WindSat data from 2004 to 2014, Indonesia has an average wind speed of above 8m/second at sea. In addition, the energy potential of the sun is around 4.8 kWh/m2. A mechanical model ship with a catamaran type will be installed photovoltaic module and wind turbine generator which are equipped with microprocessor to control the angle of the wind turbine blades, the energy generated by the PV and wind turbine generator will be regulated by the dual input buck boost converter using the PID method to regulated voltage to 14 Volt used to charge the battery. The power stored in the battery will be used to drive the ship model propulsion system. This paper discusses about pv performance, generator performance, dual input buck boost calculation, and simulation. From testing the energy obtained is 774WH. From the simulation of the dual input buck boost converter circuit, the setling time is 11ms when using the PID control system and 35ms when using PI. Energy from the sun and wind can be combined into one with a dual input buck boost converter so that the energy can be absorbed is more optimal.
Feedback remover on the sound system using inverse phase method
Authors: Hariyadi A , Perdana R H Y , Hidayati N , Ratnawati Y
Published: February 2021

Currently, almost all activities carried out by all parties are inseparable from the sound system. With the sound system, it is not necessary to speak loudly. There are several types of sound systems or models, ranging from the cheapest to the most expensive, with the usual quality up to good. However, there is a problem that can be obtained by a sound system that is of good quality or the usual quality, namely feedback from the speaker to the mic. Feedback will be very annoying because of the entry of sound from the speaker to the mic, which should be avoided. By using the inverse phase method and narrow bandpass filter, the simulation results can eliminate the feedback signal that is 100%. However, there are side effects on the band that occurs feedback, which is the reduction in the sound signal by the feedback power level that occurs between 30% - 100% that are in the frequency band range.
Object detection on dental x-ray images using deep learning method
Authors: Suryani D , Shoumi M N , Wakhidah R
Published: February 2021

Radiological examination has an important role in determining the diagnosis of dental problems and making decisions about the right type of treatment according to the case indications. Dental x-ray is a medical procedure for taking pictures of the inside of the mouth using radiation fluid, where the results are used diagnostically to help the dentist see the entire structure of the jaw bone and teeth, and dental problems that cannot be seen directly. Dental radiographic interpretation, which is generally performed by dentists, is a time-consuming and error-prone process due to high variations in tooth structure, low experience levels, and fatigue factors experienced by dentists. The workload of a dentist and the occurrence of misdiagnosis can be reduced by the existence of a system that can automatically interpret the x-ray results. To overcome these problems, a model will be developed to be able to detect objects in the dental panoramic x-ray images using Mask R-CNN, one of the methods in Deep Learning. Deep Learning is an artificial intelligence function that modelled the workings of human brain in processing data and creating patterns for use in decision making. With the detection of objects in panoramic x-ray image automatically, it is expected to save time, improve the quality of dental care, and also the quality of diagnosis made by dentists.
Software testing on e-learning Madrasahs using Blackbox testing
Authors: Sutiah S , Supriyono S
Published: February 2021

Distance learning in the pandemic era of COVID 19 must meet the needs of the system. E-Learning Madrasah is an application program developed from the Ministry of Religious Affairs of the Republic of Indonesia. The learning that can be done in the pandemic era of COVID 19 corresponds to government directives. E-Learning Madrasah has an essential role in distance learning at the basic education level up to secondary education. To improve the software functionality required testing system. The following research uses the Blackbox Testing approach to e-learning Madrasah software testing. The testing scenario includes several scenarios, including login form testing, class setting testing, computer-based test testing, student learning evaluation testing. The scenario can be used to test functionality so that the recommendation results can be used to develop e-learning madrasah in the future. The resulting results showed e-learning Madrasah using the BlackBox testing approach to testing software functionality levels with the need to reach 90%. These results show from the experiment of some of the scenarios.
Analysis of fuel pressure on the performance of motorcycle engine with ethanol fuel
Authors: Irawan B , Winoko Y A , Puspitasari E , Dwiyono T
Published: February 2021

Gasoline engines fuel cannot be directly replaced with pure ethanol, moreover ethanol contains a lot of water. The purpose of the study was to analyze the effect of fuel pump pressure on performance of 4-stroke engine motor cycle by ethanol fuel. The independent variable is pressure of the fuel and the engine speed. The dependent variable is the engine power, torque, and specific fuel consumption. The power and torque test use inertia dynamometer. The results showed the addition of fuel pump pressure, at 3.5 bar pressure can produce higher power at each engine speed with a maximum power of 6 HP at 8000 rpm. As for the best results torque obtained at a pressure of 3.5 bar which is 5,5 Nm at 7500 rpm, besides that the lowest specific fuel consumption SFC at a pressure of 3,5 bar is 0.409 kg/HPh. The results of this study can be concluded that gasoline vehicles can use ethanol fuel by increasing the fuel pressure up to 3.5 bar.
Transform Domain Analysis of Multimodal Medical Image Fusion
Authors: Hima Bindu Ch. , Sridevi G.
Published: February 2021

Fusion of multimodal medical images ensures the quality diagnosis in the field of medical sector. Fused image possess extra substance of data than input individual scanned images. The fusion process can be carried on different clinical scan images wherever more subjective data is required. In this work, we are supposed to discuss the subjective treatment of multiple transform techniques (Discrete Fourier Transform (DFT), Discrete Cosine Transform (DCT), Hadamard Transform (HT) & Discrete Wavelet Transform (DWT)) significance in fusion process. These coefficients are fused with the correlation of the spatial frequency (SF) and visibility (V) factor values. The resultant images are visually and qualitatively verified with standard execution estimates like Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE) and Root Mean Square Error (RMSE).
Expediting International Student Admission Process Using Data Analytics
Authors: Valavala Mounicasri , Alhamdani Wasim , Indukuri Hemalatha
Published: February 2021

The student admission process is a critical step from both student and university perspectives. The students will benefit if the universities take admission decisions sooner rather than later, leaving them time to opt for another university in case of rejection. However, with the level of manual work involved in the student admission process, universities often take long durations for the admission decisions. Expediting the admission process using Data analytics starts new research across different tasks in educational institutes. The research presents a model to automate each step of the international student admission process in universities across the USA, using Data analytics. The model’s distinguishing capability is that it performs both predictive and descriptive analytics to analyze different student’s application sections and adapt to different admissions types with minor changes.
Reducing Complexity in PTS Scheme using Optimization Techniques to reduce PAPR in OFDM Systems
Authors: Sarankumar R. , Sumathi K. , Sai Sravanthi G. , Venkateswarlu B. , Rajasekar P.
Published: February 2021

OFDM is a technique used to combat Inter Symbol Interference (ISI) in wireless communication systems. OFDM offers high reliable data rate over frequency selective channels. But the drawback is high Peak to Average Power Ratio (PAPR) which will affect the power amplifier in the RF front end. Partial Transmit Sequence (PTS) has proven to be the efficient technique to minimize the PAPR in OFDM systems and it does not affect the Bit Error Rate (BER) much. But PTS in turn suffers from high search complexity. The optimization algorithms can offer a tradeoff between the search complexity and PAPR reduction. In this work the phase factor optimization in PTS scheme is converted into a one dimensional optimization problem. Genetic Algorithm (GA), Simulated Annealing (SA) and Particle Swarm Optimization (PSO) are applied to the problem defined. They are also compared in terms of PAPR reduction and complexity. The fitness functions are chosen according to the optimization technique.
Antibacterial PLGA and PCL membranes, modified by magnetron sputtering method of copper target
Authors: Badaraev A D , Sidelev D V , Tverdokhlebov S I
Published: February 2021

The paper discusses barrier membranes which were formed from poly(lactide-co-glycolide) and polycaprolactone by electrospinning method. Then, plasma modification of membranes was carried out by magnetron sputtering of copper target in argon atmosphere. The morphology, elemental composition, mechanical and antibacterial properties of the obtained samples were investigated. Modification with copper in the magnetron discharge plasma allows maintaining the original characteristics of pristine polymeric samples and imparting antibacterial properties to them.
Results of long-term permeability of small-diameter vascular prostheses modified by pro-angiogenic factors and athrombogenic drug coating (model of large laboratory animals)
Authors: Krivkina E O , Mironov A V , Shabaev A R , Rezvova M A , Velikanova E A , Tkachenko V O , Khanova M Yu , Sergeeva T Y , Krutitskiy S S , Antonova L V
Published: February 2021

Developed for bypass surgery, tissue-engineered vascular grafts should remain passable after implantation and have high rate of endothelialization to ensure long-term patency, atrombogenicity and biocompatibility. This study was aimed at assessing the long-term patency of polyhydroxybutyrate/valerate (PHBV)/polycaprolactone (PCL) vascular grafts modified by pro-angiogenic factors and athrombogenic drug coating in a large laboratory animal model.
The technology for concrete production using an activated mixture of wood processing waste and sand
Authors: Kuznetsova I N
Published: February 2021

The article presents a technology for producing concrete using the waste of wood processing plants as the concrete filler. The waste was activated by mechanical, hydromechanical and hydromechanochemical technologies in a centrifugal disk installation. The established optimal ratio of sand to the waste (activated mixture) is 70:30%. The accepted fraction of the activated mixture is 10 wt% (of the mass of cement). The tests confirmed the reduction in the average density of the cement stone, while preserving its strength; the thermophysical properties of the stone increase.
Damage accumulation after temperature aging in structural GFRP in interlayer shear tests
Authors: Lobanov D S , Zubova E M
Published: February 2021

A series of quasi-static tests of the structural fiberglass reinforced polymers samples in interlayer shear by the short-beam method were carried out in this work. Mechanical tests were carried out after preliminary temperature aging with different temperature regimes and exposure duration. Diagrams of dependence of the residual interlayer strength degradation on the mode of preliminary aging are constructed. An investigation of the microstructure of GFRP specimens before and after quasi-static tests in interlayer shear was carried out. During the experimental studies the control of the damage accumulation processes and destruction was carried out using the acoustic emission method (AE). Analysis of the AE signal parameters made it possible to assess the prevalence of different destruction types of composites depending on the mode of preliminary aging.
Surfacing of Rapidly-Wearing Parts
Authors: Nazarko A S , Plomodyalo R L
Published: February 2021

This paper considers the possibility of creating cast rods for surfacing of rapidly-wearing tillage tool parts of agricultural machinery, which would not contain scarce alloying elements and provide a wear-resistant deposited metal having high hardness and high resistance to crack formation in hardened condition. It was found that with an increase in boron concentration to 0.7 … 0.8%, the amount of boride eutectic increases, which helps to prevent crystallization cracks, and the impact toughness first increases, and then slightly decreases, which is associated with the appearance of large boride inclusions.
Features of reactive SPS of SrTiO3–TiO2biphasic ceramics
Authors: Zavjalov A P , Shichalin O O , Tikhonov S A , Kosyanov D Yu
Published: February 2021

SrTiO3and biphasic SrTiO3–TiO2ceramics were obtained by reactive spark plasma sintering (SPS) of mixtures of strontium carbonate SrCO3and titanium dioxide TiO2. For monophasic SrTiO3, there is a linear seal of the mixture in the heating process. Biphasic ceramics at a temperature of about 1320°C are characterized by eutectic melting of the SrTiO3–TiO2mixture, which allowed estimating the temperature gradient in the system ∼77°/sm. Microstructural studies have confirmed the formation of biphasic SrTiO3–TiO2ceramics with a homogeneous structure and a grain size of 1÷2 μm.
Mechanochemical synthesis and antibacterial effect of CuBi2O4 nanoparticles against P. aeruginosa and S. aureus
Authors: Vázquez-Olmos A R , Rubiales-Martinez A , Almaguer-Flores A , Vega-Jiménez A L , Prado-Prone G
Published: February 2021

Nanoparticles (NPs) of CuBi2O4 with an average size around 25 nm were obtained by a novel and eco-friendly synthesis method. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) reveal that CuBi2O4 NPs possess a tetragonal crystal structure. These NPs were characterised by Raman scattering, ultraviolet-visible (UV-Vis) absorption, photoluminescence (PL), and electron paramagnetic resonance (EPR) spectroscopies. Furthermore, an in vitro study of the antibacterial effect of CuBi2O4 NPs against two bacterial strains, Pseudomonas aeruginosa (ATCC 43636) and Staphylococcus aureus (ATCC 25923), was carried out. The results obtained from the counting of colony-forming units (CFUs) and by the XTT-PMS cell viability assay showed an inhibition of the bacterial growth by 88%–87% for P. aeruginosa and 100% for S. aureus, at 50 mg ml−1 of NPs concentration. The results of this work suggest that these nanoparticles have the potential to be used as antibacterial agents by embedding them into different surfaces or being dispersed in a coating, to prevent the bacterial colonisation.
Epitaxy of boron nitride monolayers for graphene-based lateral heterostructures
Authors: Wrigley James , Bradford Jonathan , James Tyler , Cheng Tin S , Thomas James , Mellor Christopher J , Khlobystov Andrei N , Eaves Laurence , Foxon C Thomas , Novikov Sergei V , Beton Peter H
Published: February 2021

Monolayers of hexagonal boron nitride (hBN) are grown on graphite substrates using high-temperature molecular beam epitaxy (HT-MBE). The hBN monolayers are observed to grow predominantly from step edges on the graphite surface and exhibit a strong dependence of the morphology, including the dominant crystallographic edge, of the hBN monolayers, on the growth temperature, as well as systematic variations in growth rate and coverage, and significant differences in the growth at monolayer and multilayer graphite steps. At graphite monolayer steps hBN grows laterally across the surface on the lower terrace, but hBN growth on the upper side of the graphite step is more limited and is nucleated by three-dimensional clusters. Multilayer graphite steps exhibit a much higher density of non-planar hBN aggregates and growth on both the upper and lower terraces occurs. The results show that the hBN monolayer growth edge type, hBN island shape and the presence of hBN aggregates can be controlled in HT-MBE, with the highest quality layers grown at a substrate temperature of about 1390 °C. Sequential HT-MBE growth of hBN, graphene (G) and a second cycle of hBN growth results in the formation of monolayer thick lateral hBN–G–hBN heterostructures, in which a strip of G is embedded between monolayers of hBN.
Modified fiber optic sensor for highly precise identification of mercuric ion (Hg2+) concentrations in aqueous solution
Authors: Qazi Hummad Habib , Salim Mohd Rashidi bin , Bin Mohd Supa’at Abu Sahmah , Ahmed Iftikhar , Abbasi Misbah Sehar , Ali Muhammad Mahmood , Idrus Sevia Mahdaliza , Mohammad Abu Bakar bin , Sultan Irshad Muhammad , Yasmeen Farhat
Published: February 2021

A fiber optic sensor for monitoring mercuric (Hg2+) ions in the aqueous sample have been developed based on modified cladding. To fabricate a D-shaped sensing zone onto the multimode optical fiber lengthwise polishing was utilized using a mechanical end and edge polishing system. The produced sensing region has dimensions of 10 mm × 125 μm × 62 μm (l × w × h). A 2 μm thin layer of Al2O3 nanoparticles sensitized with 4-(2-pyridylazo)-resorcinol was deposited onto the sensing element of multimode fiber optic sensor to make it sensitive and selective for Hg2+ ions. The analytical results demonstrate that the sensing device has a linear response for Hg2+ ions concentration over a range from 4 to 16 ppm along with a 4 ppm limit of detection in an aqueous sample at room temperature. The selectivity of the sensor is examined for the recognition of Hg2+ ions in presence of other cations such as zinc and/or lead ions up to 16 ppm in an aqueous solution. The main merits of this fabricated sensor are easy and safe installation, rapid response, enhanced linear response range, and better selectivity towards Hg2+ ions.
Deep-learning-based quantum vortex detection in atomic Bose–Einstein condensates
Authors: Metz Friederike , Polo Juan , Weber Natalya , Busch Thomas
Published: February 2021

Quantum vortices naturally emerge in rotating Bose–Einstein condensates (BECs) and, similarly to their classical counterparts, allow the study of a range of interesting out-of-equilibrium phenomena, such as turbulence and chaos. However, the study of such phenomena requires the determination of the precise location of each vortex within a BEC, which becomes challenging when either only the density of the condensate is available or sources of noise are present, as is typically the case in experimental settings. Here, we introduce a machine-learning-based vortex detector motivated by state-of-the-art object detection methods that can accurately locate vortices in simulated BEC density images. Our model allows for robust and real-time detection in noisy and non-equilibrium configurations. Furthermore, the network can distinguish between vortices and anti-vortices if the phase profile of the condensate is also available. We anticipate that our vortex detector will be advantageous for both experimental and theoretical studies of the static and dynamic properties of vortex configurations in BECs.
Sodium/Glucose Cotransporter 2 Inhibitors and the Risk of Diabetic Ketoacidosis: An Example of Complementary Evidence for Rare Adverse Events
Authors: Alkabbani Wajd , Pelletier Ryan , Gamble John-Michael
Published: February 2021

Evidence from observational studies may be considered complementary to that of randomized controlled trials (RCTs), particularly when assessing rare outcomes of drug therapies. Sodium/glucose cotransporter 2 (SGLT-2) inhibitors are a novel class of antidiabetic agents that have been linked to an increased risk of diabetic ketoacidosis (DKA). We conducted a systematic review and separately meta-analyzed data from RCTs (n = 18; 2013–2019) and cohort studies (n = 7; 2017–2020) to assess the consistency of the magnitude of association between SGLT-2 inhibitors and DKA risk. We illustrate the strengths and weaknesses of the 2 designs. Results from RCTs and observational studies consistently showed almost a doubling in the risk of DKA among patients using an SGLT-2 inhibitor as compared with placebo or an active comparator. In a random-effects model, the pooled relative risk was 2.08 (95% confidence interval (CI): 1.28, 3.40) from placebo-controlled RCTs and 0.82 (95% CI: 0.25, 2.68) from active-comparator RCTs. The pooled adjusted hazard ratio from observational studies was 1.74 (95% CI: 1.28, 2.38). Notably, the 2 designs complement each other in several domains, including external and internal validity and power. This demonstrates a need for more comprehensive evidence when assessing rare adverse events for both sources.
Brain Activity Fluctuations Propagate as Waves Traversing the Cortical Hierarchy
Authors: Gu Yameng , Sainburg Lucas E , Kuang Sizhe , Han Feng , Williams Jack W , Liu Yikang , Zhang Nanyin , Zhang Xiang , Leopold David A , Liu Xiao
Published: February 2021

The brain exhibits highly organized patterns of spontaneous activity as measured by resting-state functional magnetic resonance imaging (fMRI) fluctuations that are being widely used to assess the brain’s functional connectivity. Some evidence suggests that spatiotemporally coherent waves are a core feature of spontaneous activity that shapes functional connectivity, although this has been difficult to establish using fMRI given the temporal constraints of the hemodynamic signal. Here, we investigated the structure of spontaneous waves in human fMRI and monkey electrocorticography. In both species, we found clear, repeatable, and directionally constrained activity waves coursed along a spatial axis approximately representing cortical hierarchical organization. These cortical propagations were closely associated with activity changes in distinct subcortical structures, particularly those related to arousal regulation, and modulated across different states of vigilance. The findings demonstrate a neural origin of spatiotemporal fMRI wave propagation at rest and link it to the principal gradient of resting-state fMRI connectivity.
Factors Associated With Peripartum Virologic Suppression in Eastern Cape Province, South Africa: A Retrospective Cross-Sectional Analysis
Authors: Adeniyi Oladele Vincent , Obi Chikwelu Larry , Goon Daniel Ter , Iweriebor Benson , Selanto-Chairman Nonkosi , Carty Craig , Avramovic Gordana , Ajayi Anthony Idowu , Lambert John , Okoh Anthony
Published: February 2021

Background

This study describes the characteristics of pregnant women on antiretroviral therapy (ART) and the rate of peripartum virologic suppression in a large prevention of mother-to-child transmission cohort who delivered in some selected maternity centers in Eastern Cape Province, South Africa. In addition, the study examines the factors associated with virologic suppression in the cohort.

Methods

This multicenter, retrospective cross-sectional analysis included medical data of 1709 women with human immunodeficiency virus between September 2015 and May 2016 in Eastern Cape Province. The main outcome measure was the rate of peripartum virologic suppression, defined as viral load (VL) <1000 copies/mL and undetectable viremia (VL <20 copies/mL). Correlates of peripartum virologic suppression and undetectable viremia were examined by fitting logistic regression model analysis.

Results

Of 1463 women with available VL results, the overall rate of peripartum suppression was 82%, and undetectable viremia was 56.9%. Being aged 24 years or younger (adjusted odds ratio [AOR], 0.68 [95% confidence interval {CI}, .48–.94]), smoking during pregnancy (AOR, 0.50 [95% CI, .28–.90]), and starting ART in the first trimester were associated with lower odds of viral suppression (<1000 copies/mL). Women who had never defaulted ART had an increased odds of having an undetectable VL (AOR, 3.09 [95% CI, 2.12–4.49]) and virologic suppression (AOR, 3.88 [95% CI, 2.62–5.74]) compared to those who defaulted.

Conclusions

More than half of the women achieved undetectable VL, and 4 in 5 women achieved viral suppression at delivery in the region. Early antenatal booking, combined with enhanced adherence support for pregnant women on ART, would be crucial toward achieving the goal of elimination of mother-to-child transmission in the region.
Resources for Families during COVID-19: A Content Analysis of Information Provided on School District Web Sites
Authors: Iachini Aidyn L , Childs Tasha M
Published: February 2021

The novel coronavirus (COVID-19) pandemic has disrupted the educational system not only in regard to teaching and learning, but also in relation to the other services and supports (mental health services, meal and nutrition programs, and so on) provided to students and families. School district Web sites are critical access points for families during this crisis to learn information about key resources being provided during school closure. This study used content analysis to examine whether school district Web sites in one southeastern state provided information about COVID-19 and 11 other resources. Findings indicate that about half of the Web sites provided both COVID-19 information and additional resources. Few districts provided information on resources for students with disabilities, a subgroup of students at heightened vulnerability during this time of virtual learning. Approximately a third of school district Web sites provided no information on COVID-19 or any of the other resources. The article concludes with a discussion of the implications for school social workers related to crisis response and leadership around contributing to efforts that aim to address educational disparities and inequities and maximize student success during this time of crisis.
Disability, Loneliness and Health in the UK: cross-sectional survey
Authors: Emerson Eric , Stancliffe Roger , Fortune Nicola , Llewellyn Gwynnyth
Published: February 2021

Background

Research has suggested that exposure to loneliness can have a powerful detrimental impact on health, including mental health. Addressing socially determined health inequity requires understanding of the situation of marginalized or vulnerable groups. People with disability are increasingly being recognized as one such group. Little population-based research has addressed the association between loneliness and health among working age adults with and without disability.

Methods

Secondary analysis of data collected in waves 8 and 9 of Understanding Society, the UK’s main annual household panel study.

Results

Rates of exposure to substantial loneliness were 25.4% (95%CI 23.5–27.3%) among adults with persistent disability (disability at W8 and W9), 15.4% (13.3–17.5%) among adults with disability onset (disability at W9 only), 12.3% (10.1–14.5%) among adults with disability offset (disability at W8 only), and 6.9% (6.5–7.3%) among adults with no disability. Exposure to loneliness was positively associated with the incidence (GHQ-12) and prevalence (SF-12 Mental) of mental health problems, but not the prevalence of physical health problems (SF-12 Physical). Disability status appeared to moderate the association between loneliness and health, with the difference between the persistent disability and no disability group increasing with exposure to greater levels of loneliness.

Conclusion

Loneliness may be an important determinant of the poorer mental health of working age adults with disability in the UK. Exposure rates are significantly higher than among the non-disabled population. The strength of association between exposure to loneliness and poorer mental health is greater for people with persistent disability than people with no disability.
Non-contrast transoesophageal echo-guided transapical transcatheter aortic valve replacement: 10-year experience of a renoprotective strategy
Authors: Mosquera Victor X , Bouzas-Mosquera Alberto , Vilela-González Yago , Oujo-González Bárbara , Velasco-García Carlos , Cuenca-Castillo José J , Herrera-Noreña José M
Published: February 2021

OBJECTIVES

This study aims to evaluate the efficacy, safety and long-term outcomes of a renoprotective non-contrast, transoesophageal echocardiography-guided transapical (TA) transcatheter aortic valve replacement (TAVR) strategy with a balloon-expandable prosthesis, as well as to determine its impact on renal function.

METHODS

Between 2009 and 2019, 200 consecutive patients underwent a non-contrast, transoesophageal echocardiography-guided TA TAVR with a balloon-expandable prosthesis.

RESULTS

The device success rate was 95.5%. Transoesophageal echocardiography-guided deployment demonstrated a low rate of procedure-related complications: 9.5% of acute kidney injury, 8% postoperative bleeding, 6% low-cardiac output, 4.5% postprocedural aortic regurgitation ≥+2, 4% implantation of permanent pacemaker and 2% stroke. There were no significant differences between preoperative and on discharge estimated glomerular filtration rate (53.9 ± 22.2 vs 54.3 ± 22.9 ml/min/1.73 m2, P = 0.60). Logistic regression analysis confirmed postoperative bleeding as an independent predictor for acute kidney injury (odds ratio (OR) 11.148, 95% confidence interval 3.537–35.140, P < 0.001). In-hospital mortality was 7.5%. The mean follow-up was 48.5 ± 39.9 months. Renal function and patient’s chronic kidney disease stage did not significantly vary during follow-up. Long-term cumulative survival at 1, 5 and 10 years was 84.2 ± 0.027%, 42.9 ± 0.038% and 32.5 ± 0.044%, respectively. Renal function affected on neither in-hospital mortality nor long-term survival.

CONCLUSIONS

Non-contrast, transoesophageal echocardiography-guided TA TAVR is a safe and reproducible technique with a low incidence of periprocedural complications that avoids the use of contrast and mitigates the incidence of acute kidney injury.
Asynchronous quadratic control for constrained hidden markov jump linear systems with incomplete MTPM and MOCPM
Authors: Zhu Jin , Xia Kai , Dullerud Geir E
Published: February 2021

This paper investigates the quadratic optimal control problem for constrained Markov jump linear systems with incomplete mode transition probability matrix (MTPM). Considering original system mode is not accessible, observed mode is utilized for asynchronous controller design where mode observation conditional probability matrix (MOCPM), which characterizes the emission between original modes and observed modes is assumed to be partially known. An LMI optimization problem is formulated for such constrained hidden Markov jump linear systems with incomplete MTPM and MOCPM. Based on this, a feasible state-feedback controller can be designed with the application of free-connection weighting matrix method. The desired controller, dependent on observed mode, is an asynchronous one which can minimize the upper bound of quadratic cost and satisfy restrictions on system states and control variables. Furthermore, clustering observation where observed modes recast into several clusters, is explored for simplifying the computational complexity. Numerical examples are provided to illustrate the validity.
L2-Betti Numbers ofC*-Tensor Categories Associated with Totally Disconnected Groups
Authors: Valvekens Matthias
Published: February 2021

We prove that the $L^2$-Betti numbers of a rigid $C^*$-tensor category vanish in the presence of an almost-normal subcategory with vanishing $L^2$-Betti numbers, generalising a result of [ 7]. We apply this criterion to show that the categories constructed from totally disconnected groups in [ 6] have vanishing $L^2$-Betti numbers. Given an almost-normal inclusion of discrete groups $\Lambda <\Gamma $, with $\Gamma $ acting on a type $\textrm{II}_1$ factor $P$ by outer automorphisms, we relate the cohomology theory of the quasi-regular inclusion $P\rtimes \Lambda \subset P\rtimes \Gamma $ to that of the Schlichting completion $G$ of $\Lambda <\Gamma $. If $\Lambda <\Gamma $ is unimodular, this correspondence allows us to prove that the $L^2$-Betti numbers of $P\rtimes \Lambda \subset P\rtimes \Gamma $ are equal to those of $G$.
Reduced Birth Weight Caused by Sextuple Drug-Resistant Plasmodium falciparum Infection in Early Second Trimester
Authors: Hansson Helle , Minja Daniel T R , Moeller Sofie L , Lusingu John P A , Bygbjerg Ib C , Yde Anna-Mathilde , Jensen Rasmus W , Nag Sidsel , Msemo Omari A , Theander Thor G , Alifrangis Michael , Schmiegelow Christentze
Published: February 2021

Mutations in the Plasmodium falciparum genes Pfdhfr and Pfdhps, particularly the sextuple mutant haplotype threatens the antimalarial effectiveness of sulfadoxine-pyrimethamine (SP) as intermittent preventive treatment during pregnancy (IPTp). To explore the impact of sextuple mutant haplotype infections on outcome measures after provision of IPTp with SP, we monitored birth outcomes in women followed up from before conception or from the first trimester until delivery. Women infected with sextuple haplotypes, in the early second trimester specifically, delivered newborns with a lower birth weight compared with women who did not have malaria during pregnancy (difference, −267 g; 95% confidence interval, −454 to −59; P = .01) and women infected with less SP-resistant haplotypes (−461 g; −877 to −44; P = .03). Thus, sextuple haplotype infections seem to affect the effectiveness of SP for IPTp and directly affect birth outcome by lowering birth weight. Close monitoring and targeted malaria control during early pregnancy is therefore crucial to improving birth outcomes.
Scanning ion-conductance microscopy with a double-barreled nanopipette for topographic imaging of charged chromosomes
Authors: Iwata Futoshi , Shirasawa Tatsuru , Mizutani Yusuke , Ushiki Tatsuo
Published: February 2021

Scanning ion conductance microscopy (SICM) is useful for imaging soft and fragile biological samples in liquids because it probes the samples’ surface topography by detecting ion currents under non-contact and force-free conditions. SICM acquires the surface topographical height by detecting the ion current reduction that occurs when an electrolyte-filled glass nanopipette approaches the sample surface. However, most biological materials have electrically charged surfaces in liquid environments, which sometimes affect the behavior of the ion currents detected by SICM and, especially, make topography measurements difficult. For measuring such charged samples, we propose a novel imaging method that uses a double-barrel nanopipette as an SICM probe. The ion current between the two apertures of the nanopipette desensitizes the surface charge effect on imaging. In this study, metaphase chromosomes of Indian muntjac were imaged by this technique because, owing to their strongly negatively charged surfaces in phosphate-buffered saline, it is difficult to obtain the topography of the chromosomes by the conventional SICM with a single-aperture nanopipette. Using the proposed method with a double-barrel nanopipette, the surfaces of the chromosomes were successfully measured, without any surface charge confounder. Since the detailed imaging of sample topography can be performed in physiological liquid conditions regardless of the sample charge, it is expected to be used for analyzing the high-order structure of chromosomes in relation to their dynamic changes in the cell division.
Diet Quality and Breast Cancer Recurrence and Survival: The Pathways Study
Authors: Ergas Isaac J , Cespedes Feliciano Elizabeth M , Bradshaw Patrick T , Roh Janise M , Kwan Marilyn L , Cadenhead Jen , Santiago-Torres Margarita , Troeschel Alyssa N , Laraia Barbara , Madsen Kristine , Kushi Lawrence H
Published: February 2021

Background

Prior research suggests a relationship between overall diet quality and breast cancer survival, although few studies have reported on this topic. We evaluated whether 4 dietary quality indices consistent with healthy eating recommendations around the time of breast cancer diagnosis were associated with risk of recurrence, cause-specific, and all-cause mortality.

Methods

A total of 3660 women diagnosed with invasive breast cancer were included. Diet was assessed an average of 2.3 (range = 0.7-18.7) months after diagnosis, from which 4 dietary quality indices were derived: the American Cancer Society guidelines (ACS), the alternate Mediterranean Diet Index (aMED), the Dietary Approaches to Stop Hypertension (DASH), and the 2015 Healthy Eating Index (HEI). Over 40 888 person-years of follow-up, 461 breast cancer recurrences, and 655 deaths were ascertained. Cox models were used to estimate hazards ratios (HRs) and 95% confidence intervals (CIs).

Results

Adjusted comparisons between extreme quintiles showed all 4 dietary quality indices to be inversely associated with all-cause mortality, suggesting a 21%-27% lower risk (ACS HR = 0.73, 95% CI = 0.56 to 0.95; aMED HR = 0.79, 95% CI = 0.61 to 1.03; DASH HR = 0.76, 95% CI = 0.58 to 1.00; HEI HR = 0.77, 95% CI = 0.60 to 1.01). Similar patterns were noted for non-breast cancer mortality (ACS HR = 0.69, 95% CI = 0.48 to 0.98; aMED HR = 0.73, 95% CI = 0.50 to 1.05; DASH HR = 0.55, 95% CI = 0.38 to 0.79; HEI HR = 0.67, 95% CI = 0.48 to 0.94). None of the dietary quality indices were associated with recurrence or breast cancer–specific mortality.

Conclusion

Food intake patterns concordant with dietary quality indices consistent with recommendations for healthy eating may be beneficial for women with breast cancer.
Directionality of butterfly leaves and nonuniform deformation mechanism in gob-side entry driving roadway
Authors: Li Ji , Wang Wenshuo , Li Bin , Tan Jihao , Peng Bo
Published: February 2021

Existing rock pressure theory, with the pressure-plastic zone as the core, cannot reveal the nonuniform large deformation mechanism of the surrounding rock in a deep roadway. To address this problem, the 11030 gob-side entry driving roadway of the Zhaogu No. 2 Mine is used as an example, in conjunction with elastoplastic mechanics theoretical analysis, to study the butterfly plastic region and the direction of the butterfly leaf in the homogeneous circular roadway. In addition, the finite-element method was used to study the environmental characteristics of the stress field of the surrounding rock before the excavation of the gob-side entry driving roadway and to analyze the effect of the principal stress on the butterfly plastic region of the surrounding rock. The results showed that, under the combined action of high ground stress and disturbed stress, the surrounding rock of the deep front edge of the gob in the central area of the main stress could form a large range for the butterfly leaf plastic area. The deflection angle of the four butterfly leaves in the plastic region was the same as that of the main stress direction. The butterfly plate plastic zone that formed in the deep surrounding rock of the gob-side entry driving roadway led to not only extension, degradation and disappearance to different degrees, but also deflection under the action of the main stress. This led to large deformation of the rock strata in the butterfly leaf plastic region, ultimately causing uneven deformation and failure of the 11030 roadway.
Toward a new generation of databases and database applications for describing ancient manuscripts
Authors: Andrist Patrick
Published: February 2021

This article analyses the reasons why current manuscript databases provide unsatisfying results about a codex’s historical layers and why they fall short when scanned for data with a date limit. It links this primarily to the fact that the data model (how the information is organized internally) and the description model (how the information is organized in the description presented to the users) are too closely and rigidly aligned. It advocates for developing a new model that would first allow users to define and save their own structural and historical interpretation of a codex, and use this when displaying or searching manuscripts. Secondly, users should be able to select the description model according to which manuscript information is displayed, including new and more detailed description models.
ORBIT
Authors: Alison Laurence J. , Alison Emily , Shortland Neil , Surmon-Bohr Frances
Published: February 2021

ORBIT is an evidence-based approach to the analysis and training for interviewing high-value detainees by law enforcement, security services, and the military. Although its origins go as far back as 2005, it gained considerable traction after 2012, when the High-Value Detainee Interrogation Group, formed by the Obama Administration in the United States, funded work for assessment of its application in the context of interviews with high-value targets. Since then, the authors have collected the largest corpus of data anywhere in the world on real suspect interviews with terrorist detainees. This book shows what they found—that rapport-based methods work and that coercion, persuasion, and threats do not. Outlining the development of their own unique stance on rapport and its influences drawn from humanistic psychology, the authors show, through real-life examples and careful analysis, the reasons why “harsh methods” must be rejected and why compassion and understanding work in interrogation.