bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimisation of droop coefficients of multiple distributed generators in a micro‐grid
Authors: Manna Dulal , Goswami Swapan K. , Chattopadhyay Pranab Kumar
Published: August 2018

An optimisation technique employing artificial bee colony algorithm has been proposed for determining the droop parameters of the distributed generators in a micro‐grid, operating in isolated mode. The proposed method minimises the active power loss and maintains a flat voltage profile. The bus interfacing the main and the micro‐grid has been treated as a voltage regulated bus so as to facilitate seamless transfer from the autonomous to the grid‐connected mode of operation and conversely.
Deep learning features for robust facial kinship verification
Authors: Tidjani Amina , Taleb‐Ahmed Abdelmalik , Samai Djamel , Kamal Eddine Aiadi
Published: August 2018

Facial automatic kinship verification is a novel challenging research problem in computer vision. It performs the automatic examining of the facial attributes and expecting whether two persons have a biological kin relation or not. In this study, the authors introduce a novel learning method for kinship verification which consists of four main stages. (i) A discrete cosine transform network (DCTNet) applied to each face image in order to extract the most significant inherited facial features through convolutional layers based on 2D DCT filter bank. (ii) The response of the last layer is binarised and partitioned into non‐overlapping block‐wise histograms. (iii) A tied rank normalisation is used to eliminate the disparity of histogram vectors of DCTNet. (iv) The last stage is to distinguish between the different pairs. The distances between data points in the same classes (positive pairs) are as small as possible, while the distances are as large as possible between data points in different classes (negative pairs). Experiments are conducted on three public databases (UBKinFace, KinFaceW‐I, and KinFaceW‐II). They show significant performance improvements compared to state‐of‐the‐art methods.
Dynamical stochastic resonance for non‐uniform illumination image enhancement
Authors: Zhang Yongbin , Liu Hongjun , Huang Nan , Wang Zhaolu
Published: August 2018

Images taken under poor illumination conditions have low contrast and dark tones. General dark image enhancement algorithms cannot effectively enhance these images without introducing over‐enhancement, detail loss, and noise amplification. In this study, a simple and fast enhancement technique of non‐uniform illumination images is proposed based on dynamical stochastic resonance (DSR). The low‐contrast images are enhanced through the nonlinear iteration by solving monostable Langevin equation. Iteration parameters are dynamically adjusted according to the intensity distribution of the original images, which ensure the balance of visibility and naturalness in the entire areas. A threshold is defined to automatically confirm the optimal outputs. The enhanced image is obtained by fusing the DSR result, original component, and illumination compensation component. The computational time, no‐reference perceptual quality assessment, and lightness order error are measured to evaluate the performance of experimental results. The subjective and objective comparison with state‐of‐the‐art methods shows that our method performs well to enhance the non‐uniform illumination images with a low‐computational complexity.
Data dissemination in service discovery for vehicular ad hoc networks: a survey
Authors: Tang Lei , Duan Zongtao , Zhu Yishui
Published: August 2018

One of the challenges posed by the study of vehicular ad hoc networks (VANETs) is the transmission of data issued by valued traffic information services under incomplete link conditions. Many dissemination protocols have been developed by the community to solve the issue. In this survey, the authors explore the service discovery where data dissemination should serve as a foundation. Then, they propose an overview and taxonomy of a large range of data dissemination available for VANETs. Finally, they illustrate the simulation infrastructure by collaborating two independent simulators. The objective is to provide guidelines to easily understand and extend the capabilities of protocols according to the users’ needs.
Using ALPR data to understand the vehicle use behaviour under TDM measures
Authors: Chang Yujiao , Duan Zhengyu , Yang Dongyuan
Published: August 2018

In Shanghai, China, two transportation demand management (TDM) measures, auctions of Shanghai vehicle licence plates and a narrow‐time‐based travel restriction policy, have been implemented to control the vehicle ownership and the use of vehicles registered outside Shanghai (VROS). To investigate the impact of these two TDM measures on VROS, vehicle use behaviour is analysed with automatic licence plate recognition (ALPR) data. A two‐step k ‐means clustering algorithm is proposed to classify VROS' use behaviour from ALPR raw data. Moreover, the spatiotemporal patterns of each type of VROS and the structure of total transportation demand are analysed. The results show that VROS in Shanghai expressway network can be classified into five types. Type 1 vehicles are used for commuting (COM), and type 2 vehicles are used with high intensity during both on workdays and non‐workdays (HHI). COM and HHI are mainly used by local Shanghai residents who cannot obtain a local licence plate under the auction policy. These two types of VROS only account for 3.6% of total vehicles but generate 14.2% of total traffic demand. If the users of COM and HHI transferred to public transit, the traffic congestion of expressway network would be greatly alleviated.
Study on isolation improvement between closely‐packed patch antenna arrays based on fractal metamaterial electromagnetic bandgap structures
Authors: Alibakhshikenari Mohammad , Virdee Bal S. , See Chan H. , Abd‐Alhameed Raed , Hussein Ali Ammar , Falcone Francisco , Limiti Ernesto
Published: August 2018

A decoupling metamaterial (MTM) configuration based on fractal electromagnetic‐bandgap (EMBG) structure is shown to significantly enhance isolation between transmitting and receiving antenna elements in a closely‐packed patch antenna array. The MTM‐EMBG structure is cross‐shaped assembly with fractal‐shaped slots etched in each arm of the cross. The fractals are composed of four interconnected‐‘Y‐shaped’ slots that are separated with an inverted‐‘T‐shaped’ slot. The MTM‐EMBG structure is placed between the individual patch antennas in a 2 × 2 antenna array. Measured results show the average inter‐element isolation improvement in the frequency band of interest is 17, 37 and 17 dB between radiation elements #1 & #2, #1 & #3, and #1 & #4, respectively. With the proposed method there is no need for using metallic‐via‐holes. The proposed array covers the frequency range of 8–9.25 GHz for X‐band applications, which corresponds to a fractional‐bandwidth of 14.5%. With the proposed method the edge‐to‐edge gap between adjacent antenna elements can be reduced to 0.5λ0 with no degradation in the antenna array's radiation gain pattern. Across the array's operating band, the measured gain varies between 4 and 7 dBi, and the radiation efficiency varies from 74.22 and 88.71%. The proposed method is applicable in the implementation of closely‐packed patch antenna arrays used in SAR and MIMO systems.
Electric field distribution and SAR inside a human eye exposed to VR glasses
Authors: Cvetković Nenad , Krstić Dejan , Stanković Vladimir , Jovanović Dejan
Published: August 2018

The aim of this study is a numerical analysis of the electric field and the specific absorption rate (SAR) distribution within a realistic 3D‐human eye model exposed to electromagnetic (EM) wave of virtual reality (VR) glasses at the frequency of third generation, long‐term evolution‐4G, and the frequency of the latest generation of mobile networks – 5G. To obtain the values of the electric field and SAR, the numerical solution of equations of EM waves propagation has been used. A new realistic 3D‐human head and human eye model has been created. The obtained results are shown for different biological tissues of the eye exposed to EM radiation from VR glasses at different frequencies. The maximum absorption of EM energy will be discussed for the following frequencies: 900 MHz, 2.6 GHz, and 28 GHz. The maximum values of electric field strength in the human eye tissue at the frequencies 28 GHz and 900 MHz are 94.43 and 137.3 V/m, respectively (higher than referent values), whereas for 2.6 GHz amounts 8.62 V/m (lower than referent limits). The obtained SAR peaks do not overcome prescribed safety values.
Frequency reconfigurable patch antenna with bias tee for wireless LAN applications
Authors: Chattha Hassan Tariq , Aftab Noman , Akram Muhammad , Sheriff Nathirulla , Huang Yi , Abbasi Qammer H.
Published: August 2018

A frequency reconfigurable printed microstrip‐fed patch antenna is proposed here. The antenna consists of a microstrip feed connected to a circular radiating element divided into three patches which are connected through silicon PIN diodes used as switches for achieving reconfigurability as being cheap and easy to implement having high switching capabilities. The slots of different shapes are etched out in all the three patches to cover all used wireless local area network (WLAN) frequency bands, including 2.4, 3.6, 4.9, 5.1, and 5.9 GHz. A bias tee is designed and connected to provide a DC bias to the PIN diodes. A prototype of the reconfigurable antenna is fabricated and measured along with the bias tee. The measured and simulated results are found in good agreement.
Performance analysis of geometry‐free and ionosphere‐free code–carrier phase observation models in integer ambiguity resolution
Authors: Bolla Padma , Won Jong‐Hoon
Published: August 2018

Geometry‐free linear combination of dual‐frequency signal code and carrier phase observations have been used for multiple purpose such as to remove ionosphere‐delays, improve the success rate in integer ambiguity resolution and accuracy in position solution. Out of three civil signals in GPS L1/L2C/L5 and Galileo E1/E5/E6, a user has many ways to form geometry‐free linear combinations to solve integer ambiguity in carrier phase observations. In precise carrier phase positioning, probability of fixing integer ambiguities using code‐carrier and carrier‐carrier difference models rely on the ionosphere bias and code phase observation noise. When three frequency signals are available, the code phase observation noise can be reduced using ionosphere delay matched linear combination of carrier phase observations. Furthermore, the low noise smoothed code phase observations can be used to form a code‐carrier difference model to fix ionosphere‐free integer ambiguity. In this study, analyzed the propagation of observation noise and ionosphere bias in a geometry‐free linear combination of GPS L1/L2/L5 code and carrier phase observations, i.e. ionosphere‐free, wide‐lane, extra wide‐lane, medium‐lane, and narrow‐lane. Further, the feasibility and success‐rate of using smoothed code phase observations in a wide‐lane integer ambiguity solution is analyzed in precise positioning applications. Experimental validation is provided.
Motion compensation of the transmitter and receiver in bistatic frequency‐modulated continuous‐wave synthetic aperture radar
Authors: Marks Daniel L. , Smith David R.
Published: August 2018

Synthetic aperture radar (SAR) imaging with an independently moving transmitter and receiver introduces motion artefacts difficult to compensate for, especially between satellites in separate orbits that rendezvous over a target. A solution for polarisation‐resolved bistatic frequency‐modulated continuous‐wave (FMCW) SAR with independently moving platforms is derived and demonstrated through simulation. This solution accounts for the polarisation of the source, susceptibility tensor of the target, and the velocity and acceleration of the transmitter and receiver. The accuracy of the solution is demonstrated by reconstructing simulated point ground targets with a pair of X‐band SAR satellites of realistic parameters.
DOA estimation based on compressed sensing with gain/phase uncertainties
Authors: Hu Bin , Wu Xiaochuan , Zhang Xin , Yang Qiang , Deng Weibo
Published: August 2018

A new direction‐of‐arrival (DOA) estimation method for the sparse receiving array with gain/phase uncertainties is proposed. Because of the sparsity of the received signals, compressed sensing theory can be used to sample and recover receiving signals with less data. Owing to the existence of the gain/phase uncertainties, it would be difficult to estimate the DOA accurately when the sparse representation of the signals is not optimal. In order to reduce the influence of the gain/phase uncertainties on the sparse representation, the authors firstly transfer the array signal receiving model with the gain/phase uncertainties into an errors‐in‐variables (EIV) model, which treats the gain/phase uncertainties as an additive error matrix. Then a new DOA estimation method named simultaneous orthogonal matching pursuit‐total least squares algorithm based on the EIV model is proposed. The DOAs will be obtained by estimating the sparse coefficients through iterations with the proposed method. Simulation results show that the sparse regularised total least squares algorithm is able to provide a more accurate DOA estimation with the gain/phase uncertainties than the existing calibration algorithms even with the sparse array.
Study of time link calibration based on GPS carrier phase observation
Authors: Zhang Pengfei , Tu Rui , Gao Yuping , Guang Wei , Zhang Rui , Cai Hongbin
Published: August 2018

The time link calibration of Global Positioning System (GPS) based on carrier phase observation has been performed in the past few years. However, the calibration accuracy is expected to be improved. In this paper, an approach of time link calibration for reducing the uncertainty is proposed. The mechanism and procedure for time link calibration based on GPS are investigated in depth firstly. And then GPS data processing method and strategies in calibration are discussed, where the precise time transfer solution (PTTSol) software is also developed. The experiment of zero baseline time link is employed, of which the standard deviation (STD) value of clock difference reaches 0.03 ns. The root mean square (RMS) value of clock difference in long distance time link is 0.11 ns which compared with the international GPS service (IGS) value. At last, one calibration campaign was organized at the national time service center (NTSC) from modified Julian day (MJD) 57598 to MJD 57616. With a travel receiver forming three common clock difference (CCD) modes, the estimated uncertainty of the calibration value was 0.13 ns, which neglected uncertainty of 1 pulse per second (1 PPS) signal relative to the local time reference point.
Fabrication and characterisation of cellulose nanocrystals from microcrystalline cellulose by esterification and ultrasound treatment
Authors: Jiang Longwei , Yang Jingde , Wang Qian , Ren Lili , Zhou Jiang
Published: August 2018

In the present work, needle‐shaped cellulose nanocrystals (CNCs) were prepared from commercial microcrystalline cellulose (MCC) through esterification and ultrasound treatment. The prepared CNCs were characterised by using Fourier transform infrared, degree of substitution (DS), dynamic light scattering, scanning electron microscopy and X‐ray diffraction. The results revealed that the ultrasound disintegration of MCC was significantly improved after the esterification with maleic anhydride and the ultrasound treatment did not affect DS of the CNCs. With increasing power of the ultrasound treatment, smaller CNCs with narrower size distribution could be obtained. Average diameter and length of the CNCs could reach ∼14 and ∼180 nm, respectively. Furthermore, the crystal structure of cellulose was not changed during the esterification and ultrasound treatment and crystallinity of the CNCs increased comparing with MCC.
Split‐gate LDMOS with double vertical field plates
Authors: Wu Lijuan , Yuan Na , Lei Bing , Zhang Yinyan , Song Yue
Published: August 2018

In this study, a novel split‐gate lateral double‐diffused metal oxide semiconductor field effect transistor with double vertical field plates (SG DVFP LDMOS) is proposed. The first feature of the SG DVFP LDMOS is that the SG with gradient gate oxide is introduced. The SG not only optimises the bulk electric field distributions to increase the breakdown voltage (BV) but also reduces the gate‐drain charge (QGD) owing to the thick gate oxide. The second feature of the SG DVFP LDMOS is the presence of the DVFP and P‐pillar. They modulate the bulk electric field distributions and assist to deplete the drift region. So the specific on‐resistance (Ron,sp) is decreased and the BV is improved. The source vertical field plate reduces the contact region between the gate and drain, thereby the QGD is reduced. Compared with the conventional SG LDMOS and rectangle‐gate DVFP LDMOS, the figure of merit FOM1 of SG DVFP LDMOS is increased by 123.2 and 86.6%, and the loss figure of merit FOM2 is enhanced to 16.9 and 37.2%. Simultaneously, the key process steps of the SG DVFP LDMOS are proposed.
Acute effects of aerobic exercise performed with different volumes on strength performance and neuromuscular parameters
Authors: Ribeiro Natalia , Ugrinowitsch Carlos , Panissa Valéria Leme Gonçalves , Tricoli Valmor
Published: August 2018

The aim of the present study was to investigate the acute effect of the aerobic exercise volume on maximum strength and strength‐endurance performance; and possible causes of strength decrements (i.e. central and peripheral fatigue). Twenty‐one moderately trained men were submitted to a maximal incremental test to determine anaerobic threshold (AnT) and maximum dynamic strength (1RM) and strength‐endurance (i.e. total volume load [TV]) tests to determine their baseline strength performance. Following, subjects performed six experimental sessions: aerobic exercise sessions (continuous running at 90% AnT) with different volumes (3 km, 5 km or 7 km) followed by 1RM or strength‐endurance test in the 45° leg press exercise. Maximum voluntary isometric contraction (MVIC), voluntary activation (VA) level, contractile properties, and electromyographic activity (root mean square [RMS]) of the knee extensor muscles were assessed before and after aerobic exercises and after strength tests. TV was lower after 5 km and 7 km runs than in the control condition (12% and 22%, respectively). Additionally, TV was lower after 7 km than 3 km (14%) and 5 km (12%) runs. MVIC, VA, RMS, and contractile properties were reduced after all aerobic exercise volumes (∼8%, ∼5%, ∼11% and ∼6–14%, respectively). Additionally, MVIC, VA, and contractile properties were lower after strength tests (∼15%, ∼6%, ∼9–26%, respectively). In conclusion, strength‐endurance performance is impaired when performed after aerobic exercise and the magnitude of this interference is dependent on the aerobic exercise volume; and peripheral and central fatigue indices could not explain the different TV observed.
A National Profile of Functional Limitations Among Asian Indians, Chinese, and Filipinos
Authors: Sharma Andy
Published: August 2018

Objectives

Asian Americans are the fastest-growing minority group in the United States, yet little is known about their functional mobility. To overcome such a gap, this study examined the association between demographic/economic characteristics and functional limitations for middle-aged and older Asian Indians, Chinese, and Filipinos.

Method

This study utilized microdata from the National Health Interview Survey pooled sample (2010–2016 IPUMS NHIS with a sample size of 6,767 Asians). Logit regressions were used to examine factors associated with functional limitations. Measures include age, gender, currently married, education (categorized as less than high school, high school, some college, college, advanced degree), birth and citizenship status, household income, home ownership, types of health insurance (e.g., Medicaid, Medicare, private), and geographic region (i.e., Northeast, Midwest, South, and West).

Results

Chinese (odds ratio [OR] 0.57, p < .01) and Filipinos (OR 0.74, p < .05) had lower odds for any functional limitations relative to Asian Indians. Currently married and individuals with a higher income were also associated with reduced odds for limitations in the overall analysis. As for the subgroup analysis, there was a positive association between age and the presence of any functional limitations for Asian Indians (OR 1.05, p < .01), Chinese (OR 1.08, p < .01), and Filipinos (OR 1.03, p < .01). In terms of gender, Asian Indian men were less likely (OR 0.51, p < .01), whereas Filipino men were more likely to have limitations (OR 1.09, p < .05).

Discussion

Asian Indians appeared to have a poorer health profile for limitations in dressing, eating, walking, or working when compared with Chinese and Filipinos. A pronounced difference at older ages was also apparent for Asian Indians by gender and the likelihood of having any limitations increased much faster for Asian Indian women. For Chinese, there was a dramatic increase in functional limitations after age 75 (particularly for women) and the predicted probability for this subgroup approximated 20%. For Filipinos, men were more likely to have limitations. These findings raise interesting questions about the on-set of disability by age and gender for Asian subgroups.
Commercial fisheries losses arising from interactions with offshore pipelines and other oil and gas infrastructure and activities
Authors: Rouse Sally , Hayes Peter , Wilding Thomas A
Published: August 2018

Interactions between fishing vessels and oil and gas infrastructure can result in damage to fishing gear, loss of fishing time/access, and risks to crew health and safety. The spatial and temporal patterns characterizing previous incidents (and subsequent losses) between fishers and oil and gas infrastructure were quantified and used to identify key risk factors associated with fisheries losses. Between the years 1989 and 2016, 1590 incidents that resulted in a financial loss, vessel abandonment, or an injury/fatality for UK commercial fishers were recorded. The annual number of recorded incidents decreased by 98.6% over a 27-year period. The majority of past incidences resulted in financial losses (rather than injuries or fatalities) and were associated with interactions between single otter trawlers and oil and gas production-related debris. The odds of an incidence occurring varied according to substrate type and fishing intensity. A risk-model for pipeline–fishing interactions in the Fladen Ground showed that there was significant spatial heterogeneity in the risk of an incident along a pipeline according to the angle and intensity of fishing. The results highlight the need to include the full spectrum of potential losses in fisheries impact assessments associated with the installation and decommissioning of oil and gas assets.
The therapy is making me sick: how online portal communications between breast cancer patients and physicians indicate medication discontinuation
Authors: Yin Zhijun , Harrell Morgan , Warner Jeremy L , Chen Qingxia , Fabbri Daniel , Malin Bradley A
Published: August 2018

Objective

Online platforms have created a variety of opportunities for breast patients to discuss their hormonal therapy, a long-term adjuvant treatment to reduce the chance of breast cancer occurrence and mortality. The goal of this investigation is to ascertain the extent to which the messages breast cancer patients communicated through an online portal can indicate their potential for discontinuing hormonal therapy.

Materials and Methods

We studied the de-identified electronic medical records of 1106 breast cancer patients who were prescribed hormonal therapy at Vanderbilt University Medical Center over a 12-year period. We designed a data-driven approach to investigate patients’ patterns of messaging with healthcare providers, the topics they communicated, and the extent to which these messaging behaviors associate with the likelihood that a patient will discontinue a prescribed 5-year regimen of therapy.

Results

The results indicates that messaging rate over time [hazard ratio (HR) = 1.373, P = 0.002], mentions of side effects (HR = 1.214, P = 0.006), and surgery-related topics (HR = 1.170, P = 0.034) were associated with increased risk of early medication discontinuation. In contrast, seeking professional suggestions (HR = 0.766, P = 0.002), expressing gratitude to healthcare providers (HR = 0.872, P = 0.044), and mentions of drugs used to treat side effects (HR = 0.807, P = 0.013) were associated with decreased risk of medication discontinuation.

Discussion and Conclusion

This investigation suggests that patient-generated content can inform the study of health-related behaviors. Given that approximately 50% of breast cancer patients do not complete a course of hormonal therapy as described, the identification of factors associated with medication discontinuation can facilitate real-time interventions to prevent early discontinuation.
Colorectal Cancer Incidence and Mortality Rates Among New York City Adults Ages 20–54 years during 1976–2015
Authors: Van Beck Kellie C , Jasek John , Roods Kristi , Brown Jennifer J , Farley Shannon M , List Justin M
Published: August 2018

Colorectal cancer (CRC) incidence rates are rising in younger Americans and mortality rates are increasing among younger white Americans. We used New York State Cancer Registry data to examine New York City CRC incidence and mortality trends among adults ages 20–54 years by race from 1976 to 2015. Annual percent change (APC) was considered statistically significant at P less than .05 using a two-sided test. CRC incidence increased among those ages 20–49 years, yet blacks had the largest APC of 2.2% (1993–2015; 95% confidence interval [CI] = 1.4% to 3.1%) compared with 0.5% in whites (1976–2015; 95% CI = 0.2% to 0.7%). Among those aged 50–54 years, incidence increased among blacks by 0.8% annually (1976–2015; 95% CI = 0.4% to 1.1%), but not among whites. CRC mortality decreased among both age and race groups. These findings emphasize the value of local registry data to understand trends locally, the importance of timely screening, and the need for clinicians to consider CRC among all patients with compatible signs and symptoms.
Temporal Trends in Co-trimoxazole Use Among Children on Antiretroviral Therapy and the Impact of Co-trimoxazole on Mortality Rates in Children Without Severe Immunodeficiency
Authors: Boettiger David C , Law Matthew G , Sohn Annette H , Davies Mary-Ann , Wools-Kaloustian Kara , Leroy Valeriane , Yotebieng Marcel , Vinikoor Michael , Vreeman Rachel , Amorissani-Folquet Madeleine , Edmonds Andrew , Fatti Geoffrey , Batte James , Renner Lorna , Adedimeji Adebola , Kariminia Azar ,   The International Epidemiology Databases to Evaluate AIDS
Published: August 2018

Background

Co-trimoxazole is recommended for all children with human immunodeficiency virus. In this analysis, we evaluate trends in pediatric co-trimoxazole use and survival on co-trimoxazole in children using antiretroviral therapy (ART).

Methods

We used data collected between January 1, 2006, and March 31, 2016, from the International Epidemiology Databases to Evaluate AIDS. Logistic regression was used to evaluate factors associated with using co-trimoxazole at ART initiation. Competing risk regression was used to assess factors associated with death.

Results

A total of 54113 children were included in this study. The prevalence of co-trimoxazole use at ART initiation increased from 66.5% in 2006 to a peak of 85.6% in 2010 and then declined to 48.5% in 2015–2016. A similar trend was observed among children who started ART with severe immunodeficiency. After adjusting for year of ART initiation, younger age (odds ratio [OR], 1.18 for <1 vs 1 to <5 years of age [95% confidence interval (CI), 1.09–1.28]), lower height-for-age z score (OR, 1.15 for less than −3 vs greater than −2 [95% CI, 1.08–1.22]), anemia (OR, 1.08 [95% CI, 1.02–1.15]), severe immunodeficiency (OR, 1.25 [95% CI, 1.18–1.32]), and receiving care in East Africa (OR, 8.97 vs Southern Africa [95% CI, 8.17–9.85]) were associated with a high prevalence of co-trimoxazole use. Survival did not differ according to co-trimoxazole use in children without severe immunodeficiency (hazard ratio, 1.01 for nonusers versus users [95% CI, 0.77–1.34]).

Conclusions

Recent declines in co-trimoxazole use may not be linked to the current shift toward early ART initiation. Randomized trial data might be needed to establish the survival benefit of co-trimoxazole in children without severe immunodeficiency.
Returns to Operating Room After Neurosurgical Procedures in a Tertiary Care Academic Medical Center: Implications for Health Care Policy and Quality Improvement
Authors: Kerezoudis Panagiotis , Glasgow Amy E , Alvi Mohammed Ali , Spinner Robert J , Meyer Fredric B , Bydon Mohamad , Habermann Elizabeth B
Published: August 2018

BACKGROUND

Return to the operating room (ROR) has been put forth by the National Quality Forum and the American College of Surgeons as a surgical quality indicator. However, current quality metrics fail to consider the nature and etiology of the ROR.

OBJECTIVE

To provide a comprehensive description of all reoperations after neurosurgical procedures and assess the validity of ROR as a quality measure in neurosurgery.

METHODS

We retrospectively analyzed all neurosurgical procedures performed in a high-volume, tertiary care academic medical center between June 1, 2014 and December 31, 2016. Based on a system constructed and validated at our institution, we classified RORs into (a) unplanned related, (b) planned return due to complications, (c) planned-staged return, or (d) unrelated return.

RESULTS

A total of 9200 unique neurosurgical cases were identified, of which 788 had an ROR within 45 d (8.6%). Median time to ROR (interquartile range) was 9 d (4-15). Specifically, 4.2% were planned-staged returns, 3.4% were unplanned related, 0.3% were unrelated, and 0.6% were planned because of previous complications. Cranial procedures had the highest unplanned ROR rate (4.2%), followed by spinal (2.8%) and peripheral nerve (0.4%). The most common reason for an unplanned ROR was wound complication/surgical site infection (34.3%), followed by hematoma evacuation (13.9%) and cerebrospinal fluid (CSF) leak (11.3%).

CONCLUSION

Unplanned RORs were relatively rare and most commonly associated with wound complication, postoperative hematoma, and CSF leak. To better reflect surgical quality, ROR metrics should indicate whether the return was planned or unrelated.
Low Case Finding Among Men and Poor Viral Load Suppression Among Adolescents Are Impeding Namibia’s Ability to Achieve UNAIDS 90-90-90 Targets
Authors: Agolory Simon , de Klerk Michael , Baughman Andrew L , Sawadogo Souleymane , Mutenda Nicholus , Pentikainen Ndumbu , Shoopala Naemi , Wolkon Adam , Taffa Negussie , Mutandi Gram , Jonas Anna , Mengistu Assegid Tassew , Dzinotyiweyi Edington , Prybylski Dimitri , Hamunime Ndapewa , Medley Amy
Published: August 2018

Background

In 2015, Namibia implemented an Acceleration Plan to address the high burden of HIV (13.0% adult prevalence and 216 311 people living with HIV [PLHIV]) and achieve the UNAIDS 90-90-90 targets by 2020. We provide an update on Namibia’s overall progress toward achieving these targets and estimate the percent reduction in HIV incidence since 2010.

Methods

Data sources include the 2013 Namibia Demographic and Health Survey (2013 NDHS), the national electronic patient monitoring system, and laboratory data from the Namibian Institute of Pathology. These sources were used to estimate (1) the percentage of PLHIV who know their HIV status, (2) the percentage of PLHIV on antiretroviral therapy (ART), (3) the percentage of patients on ART with suppressed viral loads, and (4) the percent reduction in HIV incidence.

Results

In the 2013 NDHS, knowledge of HIV status was higher among HIV-positive women 91.8% (95% confidence interval [CI], 89.4%–93.7%) than HIV-positive men 82.5% (95% CI, 78.1%–86.1%). At the end of 2016, an estimated 88.3% (95% CI, 86.3%–90.1%) of PLHIV knew their status, and 165 939 (76.7%) PLHIV were active on ART. The viral load suppression rate among those on ART was 87%, and it was highest among ≥20-year-olds (90%) and lowest among 15–19-year-olds (68%). HIV incidence has declined by 21% since 2010.

Conclusions

With 76.7% of PLHIV on ART and 87% of those on ART virally suppressed, Namibia is on track to achieve UNAIDS 90-90-90 targets by 2020. Innovative strategies are needed to improve HIV case identification among men and adherence to ART among youth.
Posterior Cervical Laminoplasty for Resection Intradural Extramedullary Spinal Meningioma: 2-Dimensional Operative Video
Authors: Dekker Simone E , Ostergard Thomas A , Glenn Chad A , Cox Efrem , Bambakidis Nicholas C
Published: August 2018

This operative video demonstrates a posterior cervical laminoplasty for the resection of a cervical intradural extramedullary meningioma. In addition, the natural history, treatment options, and potential complications are discussed. The patient is a 68-yr-old male who presented with left-hand grip weakness and paresthesias. Magnetic resonance imaging (MRI) demonstrated an enhancing mass that displacing the spinal cord anteriorly and causing severe flattening of the cord at C4 and C5. The patient underwent a posterior cervical laminoplasty for tumor resection. Removal of the dorsal elements with a high-speed drill was performed at C3, C4, and C5. A midline durotomy was performed and a large extra-axial intradural tumor was encountered. The tumor was resected en bloc and specimens were sent for permanent pathological analysis. The dura was closed in a watertight fashion using 6-0 Prolene sutures. The laminoplasty was performed by using titanium miniplates and screws to reconstruct the dorsal bony elements, and the wound was closed in layers using sutures. There were no complications. Final pathology was consistent with a WHO grade I meningioma. Postoperative MRI demonstrated gross total resection. The patient's perioperative course was uncomplicated and his preoperative weakness completely resolved by time of discharge.
‘For the Many, Not the Few’: Strategising the Campaign Trail at the 2017 UK General Election
Authors: Middleton Alia
Published: August 2018

During the 2017 general election campaign, the Conservative and Labour leaders toured the country. While Theresa May operated a conventional approach, encapsulated by limited interactions with the public, Jeremy Corbyn participated in public rallies and appeared at music festivals. This article examines the strategic decisions underpinning leader visits in the 2017 campaign trail. It finds that May and Corbyn’s electoral strategies had more in common than at first sight. The article adds to existing studies by using new interview data from local party campaigners to understand visit organisation and impact on the local campaign. It also makes an important step towards unpicking the causal mechanism through which these visits may affect voter behaviour.
Is the infrared background excess explained by the isotropic zodiacal light from the outer solar system?
Authors: Tsumura Kohji
Published: August 2018

This paper investigates whether an isotropic zodiacal light from the outer solar system can account for the detected background excess in the near-infrared. Assuming that interplanetary dust particles are distributed in a thin spherical shell at the outer solar system (>200 au), thermal emission from such cold (<30 K) dust in the shell has a peak at the far-infrared (∼100 μm). By comparing the calculated thermal emission from the dust shell with the observed background emissions at the far-infrared, the permissible dust amount in the outer solar system is obtained. Even if the maximum dust amount is assumed, the isotropic zodiacal light as the reflected sunlight from the dust shell at the outer solar system cannot explain the detected background excess at the near-infrared.
Resting state functional connectivity patterns associated with pharmacological treatment resistance in temporal lobe epilepsy
Authors: Pressl Christina , Brandner Philip , Schaffelhofer Stefan , Blackmon Karen , Dugan Patricia , Holmes Manisha , Thesen Thomas , Kuzniecky Ruben , Devinsky Orrin , Freiwald Winrich A.
Published: August 2018

There are no functional imaging based biomarkers for pharmacological treatment response in temporal lobe epilepsy (TLE). In this study, we investigated whether there is an association between resting state functional brain connectivity (RsFC) and seizure control in TLE. We screened a large database containing resting state functional magnetic resonance imaging (Rs-fMRI) data from 286 epilepsy patients. Patient medical records were screened for seizure characterization, EEG reports for lateralization and location of seizure foci to establish uniformity of seizure localization within patient groups. Rs-fMRI data from patients with well-controlled left TLE, patients with treatment-resistant left TLE, and healthy controls were analyzed. Healthy controls and cTLE showed similar functional connectivity patterns, whereas trTLE exhibited a significant bilateral decrease in thalamo-hippocampal functional connectivity. This work is the first to demonstrate differences in neural network connectivity between well-controlled and treatment-resistant TLE. These differences are spatially highly focused and suggest sites for the etiology and possibly treatment of TLE. Altered thalamo-hippocampal RsFC thus is a potential new biomarker for TLE treatment resistance.

Resting State functional magnetic resonance imaging (Rs-fMRI), previously utilized to predict lateralization of seizure foci in temporal lobe epilepsy (TLE), is utilized to determine potential mechanisms and biomarkers for treatment-resistant and well-controlled unilateral TLE. We found significant differences in thalamo-hippocampal functional connectivity between treatment-resistant and well-controlled TLE patients. Differences in functional connectivity were focused to thalamo-hippocampal connections and more pronounced in the hemisphere ipsilateral to seizure foci. Aberrant functional connectivity patterns as measured by Rs-fMRI could thus serve as biomarkers for treatment response in TLE.
Morphological and genomic characterisation of the hybrid schistosome infecting humans in Europe reveals a complex admixture between Schistosoma haematobium and Schistosoma bovis parasites
Authors: Kincaid-Smith Julien , Tracey Alan , Augusto Ronaldo , Bulla Ingo , Holroyd Nancy , Rognon Anne , Rey Olivier , Chaparro Cristian , Oleaga Ana , Mas-Coma Santiago , Allienne Jean-François , Grunau Christoph , Berriman Matthew , Boissier Jérôme , Toulza Eve
Published: August 2018

Schistosomes cause schistosomiasis, the world’s second most important parasitic disease after malaria. A peculiar feature of schistosomes is their ability to produce viable and fertile hybrids. Originally only present in the tropics, schistosomiasis is now also endemic in Europe. Based on two genetic markers the European species had been identified as a hybrid between the ruminant-infective Schistosoma bovis and the human-infective Schistosoma haematobium.

Here we describe for the first time the genomic composition of the European schistosome hybrid (77% of S. haematobium and 23% of S. bovis origins), its morphometric parameters and its compatibility with the European vector snail and intermediate host Compatibility is a key parameter for the parasites life cycle progression. We also show that egg morphology (a classical diagnostic parameter) does not allow for differential diagnosis while genetic tests do so. Additionally, we performed genome assembly improvement and annotation of S. bovis, the parental species for which no satisfactory genome assembly was available.

For the first time since the discovery of hybrid schistosomes, these results reveal at the whole genomic level a complex admixture of parental genomes highlighting (i) the high permeability of schistosomes to other species’ alleles, and (ii) the importance of hybrid formation for pushing species boundaries not only conceptionally but also geographically.
Hierarchical Patient-centric Caregiver Network Method for Clinical Outcomes Study
Authors: Park Yoonyoung , Karampourniotis Panagiotis D. , Sylla Issa , Das Amar K.
Published: August 2018

In clinical outcome studies, analysis has traditionally been performed using patient-level factors, with minor attention given to provider-level features. However, the nature of care coordination and collaboration between caregivers (providers) may also be important in determining patient outcomes. Using data from patients admitted to intensive care units at a large tertiary care hospital, we modeled the caregivers that provided medical service to a specific patient as patient-centric subnetwork embedded within larger caregiver networks of the institute. The caregiver networks were composed of caregivers who treated either a cohort of patients with particular disease or any patient regardless of disease. Our model can generate patient-specific caregiver network features at multiple levels, and we demonstrate that these multilevel network features, in addition to patient-level features, are significant predictors of length of hospital stay and in-hospital mortality.
Hyperspectral Reflectance-Derived Relationship Matrices for Genomic Prediction of Grain Yield in Wheat
Authors: Krause Margaret R. , González-Pérez Lorena , Crossa José , Pérez-Rodríguez Paulino , Montesinos-López Osval , Singh Ravi P. , Dreisigacker Susanne , Poland Jesse , Rutkoski Jessica , Sorrells Mark , Gore Michael A. , Mondal Suchismita
Published: August 2018

Hyperspectral reflectance phenotyping and genomic selection are two emerging technologies that have the potential to increase plant breeding efficiency by improving prediction accuracy for grain yield. Hyperspectral cameras quantify canopy reflectance across a wide range of wavelengths that are associated with numerous biophysical and biochemical processes in plants. Genomic selection models utilize genome-wide marker or pedigree information to predict the genetic values of breeding lines. In this study, we propose a multi-kernel GBLUP approach to genomic selection that uses genomic marker-, pedigree-, and hyperspectral reflectance-derived relationship matrices to model the genetic main effects and genotype × environment (G×E) interactions across environments within a bread wheat (Triticum aestivumL.) breeding program. We utilized an airplane equipped with a hyperspectral camera to phenotype five differentially managed treatments of the yield trials conducted by the Bread Wheat Improvement Program, International Maize and Wheat Improvement Center (CIMMYT) at Ciudad Obregón, México over four breeding cycles. We observed that single-kernel models using hyperspectral reflectance-derived relationship matrices performed similarly or superior to marker-and pedigree-based genomic selection models when predicting within and across environments. Multi-kernel models combining marker/pedigree information with hyperspectral reflectance phentoypes had the highest prediction accuracies; however, improvements in accuracy over marker-and pedigree-based models were marginal when correcting for days to heading. Our results demonstrates the potential of hyperspectral imaging in predicting grain yield within a multi-environment context, it also supports further studies on integration of hyperspectral reflectance phenotyping in breeding programs.
Octave plots for visualizing diversity of microbial OTUs
Authors: Edgar Robert C. , Flyvbjerg Henrik
Published: August 2018

Next-generation sequencing of marker genes such as 16S ribosomal RNA is widely used to survey microbial communities. The abundance distribution (AD) of Operational Taxonomic Units (OTUs) in a sample is typically summarized by alpha diversity metrics, e.g. richness and entropy, discarding information about the AD shape. In this work, we describe octave plots, histograms which visualize the shape of microbial ADs by binning on a logarithmic scale with base 2. Optionally, histogram bars are colored to indicate possible spurious OTUs due to sequence error and cross-talk. Octave plots enable assessment of (a) the shape and completeness of the distribution, (b) the effects of noise on measured diversity, (c) whether low-abundance OTUs should be discarded, (d) whether alpha diversity metrics and estimators are reliable, and (e) the additional sampling effort (i.e., read depth) required to obtain a complete census of the community. The utility of octave plots is illustrated in a re-analysis of a prostate cancer study showing that the reported core microbiome is most likely an artifact of experimental error.
Type IV pilin post-translational modifications modulate materials properties of bacterial colonies
Authors: Zöllner R. , Cronenberg T. , Kouzel N. , Welker A. , Koomey M. , Maier B.
Published: August 2018

Bacterial type 4 pili (T4P) are extracellular polymers that initiate the formation of microcolonies and biofilms. T4P continuously elongate and retract. These pilus dynamics crucially affects the local order, shape, and fluidity of microcolonies. The major pilin subunit of the T4P bears multiple post-translational modifications. By interfering with different steps of the pilin glycosylation and phosphoform modification pathways, we investigated the effect of pilin post-translational modification on the shape and dynamics of microcolonies formed by Neisseria gonorrhoeae. Deleting the phosphotransferase responsible for phosphoethanolamine modification at residue serine 68 (S68) inhibits shape relaxations of microcolonies after pertubation and causes bacteria carrying the phosphoform modification to segregate to the surface of mixed colonies. We relate these mesoscopic phenotypes to increased attractive forces generated by T4P between cells. Moreover, by deleting genes responsible for the pilin glycan structure, we show that the number of saccharides attached at residue serine 63 (S63) affect the ratio between surface tension and viscosity and cause sorting between bacteria carrying different pilin glycoforms. We conclude that different pilin post-translational modifications moderately affect the attractive forces between bacteria but have severe effects on the materials properties of microcolonies.
Latent Structure of Risk Perception
Authors: Pabon Elisa , MacKillop James , Palmer Abraham A. , de Wit Harriet
Published: August 2018

Risk-taking behavior affects many aspects of life, including maladaptive behaviors such as illicit substance use, unsafe driving, and risky sexual behavior. Risk-taking has been measured using both self-report measures and behavioral tasks designed for the purpose, but there is little consensus in the associations among measures and our understanding of the latent constructs underlying different forms of risk is limited. In the present study we examined the construct of risk using data from over 1000 young adults who completed measures of risk-taking, including self-reports of perception of risk, propensity to engage in risky behaviors and performance on behavioral tasks designed to measure risk. To examine the latent structure of risk preferences, we conducted a principal component analysis (PCA). The PCA revealed a latent structure of three distinct components of risk-taking behavior: “Lifestyle Risk Sensitivity”, “Financial Risk Sensitivity”, and “Behavioral Risk Sensitivity”,which consisted only of the Balloon Analogue Risk Task (BART; Lejuez et al., 2002). As expected, risk-taking and perception of risk differed in men and women. Yet, the PCA components were similar in men and women. Future work utilizing additional measures of risk-taking behavior in more heterogeneous samples will help to identify the true biobehavioral constructs underlying these behaviors.