bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding the interplay between covariance forecasting factor models and risk‐based portfolio allocations in currency carry trades
Authors: Ames Matthew , Bagnarosa Guillaume , Peters Gareth W. , Shevchenko Pavel V.
Published: February 2018

With the exception of naive methods for portfolio selection, such as the equal weighted approaches, all other methods of portfolio allocation are more or less sensitive to the quality of the inputs considered in constructing the models and risk measures utilized in the allocation framework. The extensively used factor model proposed initially by Sharpe in 1963 has provided a robust backdrop for development of relevant, micro, macro, and context‐specific or asset specific explanatory variables to be incorporated in a statistical manner as inputs to forecasting models that can then be used to obtain risk measures upon which portfolio allocations are based. However, like all statistical models, a set of statistical assumptions accompany this factor model regression framework, one of which has recently been highlighted as seemingly nonvalidated in financial data. This is, of course, the assumption such factor models make on homoskedasticity or weak‐sense covariance stationarity of the returns processes being modeled. Such factor models, therefore, have typically failed to cope with an important and ubiquitous feature of financial assets data, which often demonstrates heteroskedasticity of the returns variances and covariances. We propose a novel generalized multifactor forecasting structure utilizing a covariance regression model, which allows us to incorporate the required heteroskedasticity effects while also admitting potential dependence in the idiosyncratic error terms. We argue that such a modeling approach allows for more explicit relationships to be interpreted between the driving factors and the conditional responses of the portfolio returns. We then compare the forecasting performances of our model with the multifactor model and the time series dynamic conditional correlation model through a currency portfolio application.
Prospective study of blood metabolites associated with colorectal cancer risk
Authors: Shu Xiang , Xiang Yong‐Bing , Rothman Nathaniel , Yu Danxia , Li Hong‐Lan , Yang Gong , Cai Hui , Ma Xiao , Lan Qing , Gao Yu‐Tang , Jia Wei , Shu Xiao‐Ou , Zheng Wei
Published: February 2018

Few prospective studies, and none in Asians, have systematically evaluated the relationship between blood metabolites and colorectal cancer risk. We conducted a nested case–control study to search for risk‐associated metabolite biomarkers for colorectal cancer in an Asian population using blood samples collected prior to cancer diagnosis. Conditional logistic regression was performed to assess associations of metabolites with cancer risk. In this study, we included 250 incident cases with colorectal cancer and individually matched controls nested within two prospective Shanghai cohorts. We found 35 metabolites associated with risk of colorectal cancer after adjusting for multiple comparisons. Among them, 12 metabolites were glycerophospholipids including nine associated with reduced risk of colorectal cancer and three with increased risk [odds ratios per standard deviation increase of transformed metabolites: 0.31–1.98; p values: 0.002–1.25 × 10−10]. The other 23 metabolites associated with colorectal cancer risk included nine lipids other than glycerophospholipid, seven aromatic compounds, five organic acids and four other organic compounds. After mutual adjustment, nine metabolites remained statistically significant for colorectal cancer. Together, these independently associated metabolites can separate cancer cases from controls with an area under the curve of 0.76 for colorectal cancer. We have identified that dysregulation of glycerophospholipids may contribute to risk of colorectal cancer.
Hemodialysis monitoring using mid‐ and near‐infrared spectroscopy with partial least squares regression
Authors: Henn Raphael , Kirchler Christian G. , Schirmeister Zora L. , Roth Andreas , Mäntele Werner , Huck Christian W.
Published: February 2018

Blood constituents such as urea, glucose, lactate, phosphate and creatinine are of high relevance in monitoring the process of detoxification in ambulant dialysis treatment. In the present work, 2 different vibrational spectroscopic techniques are used to determine those molecules quantitatively in artificial dialysate solutions. The goal of the study is to compare the performance of near‐infrared (NIR) and mid‐infrared (MIR) spectroscopy in hyphenation with partial least squares regression (PLSR) directly by using the same sample set. The results show that MIR spectroscopy is better suited to analyze the analytes of interest. Multilevel multifactor design is used to cover the relevant concentration variations during dialysis. MIR spectroscopy coupled to a multi reflection attenuated total reflection (ATR) cell enables reliable prediction of all target analytes. In contrast, the NIR spectroscopic method does not give access to all 5 components but only to urea and glucose. For both methods, coefficients of determination greater or equal to 0.86 can be achieved in the test‐set validation process for urea and glucose. Lactate, phosphate and creatinine perform well in the MIR with R2 ≥ 0.95 using test‐set validation.
Successful encapsulation of β‐glucosidase during the synthesis of siliceous mesostructured materials
Authors: Gascón Victoria , Márquez‐Álvarez Carlos , Blanco Rosa María
Published: February 2018

BACKGROUND

The biocatalysis field demands ‘universal’ supports able to encapsulate enzymes with a straightforward methodology, and at the same time, capable of retaining their catalytic activity. The employment of siliceous materials for such a purpose is a big challenge because drastic synthesis conditions are required and improved functionalization is needed to increase affinities towards the targeted enzyme. In this work, a compromise between the development of a well‐formed mesostructured support and an acceptable enzymatic activity was attempted via the in‐situ immobilization approach.

RESULTS

The immobilization of β‐glucosidase (EC 3.2.1.21) from Aspergillus niger was approached using different strategies. After trying to immobilize β‐glucosidase with a post‐synthesis approach, nonhigh loadings were achieved both with covalent linkage (using epoxy activated supports; 3.5 mgE g−1) and with noncovalent bonding (using amine‐functionalized materials; 7.6 mgE g−1). However, when the in‐situ approach was attempted, success in reaching the highest enzyme loading (close to 200 mgE g−1) was achieved.

CONCLUSION

In this work, the support cages around the in‐situ encapsulated enzyme fully prevented its release through the narrow windows connecting cages, achieving a less than 5% release of the initially desorbed protein, as well as a further total absence of leaching. This enabled the biocatalyst to be reused at least eight times more without any loss in activity. © 2018 Society of Chemical Industry
Where have all the children gone? High HIV prevalence in infants attending nutrition and inpatient entry points
Authors: Kiyaga Charles , Urick Brittany , Fong Youyi , Okiira Christopher , Nabukeera‐Barungi Nicolette , Nansera Denis , Ochola Emmanuel , Nteziyaremye Julius , Bigira Victor , Ssewanyana Isaac , Olupot‐Olupot Peter , Peter Trevor , Ghadrshenas Anisa , Vojnov Lara
Published: February 2018

Introduction

Despite notable progress towards PMTCT, only 50% of HIV‐exposed infants in sub‐Saharan Africa were tested within the first 2 months of life and only 30% of HIV‐infected infants are on antiretroviral treatment. This study assessed HIV prevalence in infants and children receiving care at various service entry points in primary healthcare facilities in Uganda.

Methods

A total of 3600 infants up to 24 months of age were systematically enrolled and tested at four regional hospitals across Uganda. Six hundred infants were included and tested from six facility entry points: PMTCT, immunization, inpatient, nutrition, outpatient and community outreach services.

Findings

The traditional EID entry point, PMTCT, had a prevalence of 3.8%, representing 19.6% of the total HIV‐positive infants identified in the study. Fifty percent of the 117 identified HIV‐positive infants were found in the nutrition wards, which had a prevalence of 9.8% (p < 0.001 compared to PMTCT). Inpatient wards had a prevalence of 3.5% and yielded 17.9% of the HIV‐positive infants identified. Infants tested at immunization wards and through outreach services identified 0.8% and 1.7% of the HIV‐positive infants respectively, and had a prevalence of less than 0.3%.

Conclusions

Expanding routine early infant diagnosis screening beyond the traditional PMTCT setting to nutrition and inpatient entry points will increase the identification of HIV‐infected infants. Careful reflection for appropriate testing strategies, such as maternal re‐testing to identify new HIV infections and HIV‐exposed infants in need of follow‐up testing and care, at immunization and outreach services should be considered given the expectedly low prevalence rates. These findings may help HIV care programmes significantly expand testing to improve access to early infant diagnosis and paediatric treatment.
Diagnostic accuracy of a clinical carotid plaque MR protocol using a neurovascular coil compared to a surface coil protocol
Authors: Brinjikji Waleed , DeMarco J. Kevin , Shih Robert , Lanzino Giuseppe , Rabinstein Alejandro A. , Hilditch Christopher A. , Nicholson Patrick J. , Huston John
Published: February 2018

Background

Carotid plaque imaging with MRI is becoming more commonplace, but practical challenges exist in performing plaque imaging with surface coils.

Purpose

To compare the diagnostic performance of a carotid plaque MRI protocol using a standard neurovascular coil (Neurovascular Coil Protocol) to a higher‐resolution carotid plaque MRI using carotid surface coils (Surface Coil Protocol) in characterizing carotid plaque.

Study Type

Prospective study comparing two MR techniques in plaque characterization.

Population

Thirty‐eight consecutive carotid artery disease patients.

Field Strength/Sequence

Patients underwent 3T MRI using 1) a Neurovascular Coil Protocol including the following sequences: 3D‐FSE T1 pre/postcontrast and precontrast 3D IR‐FSPGR, and 2) a Surface Coil Protocol using standard multicontrast MRI sequences.

Assessment

Plaque characteristics analyzed by two independent neuroradiologists included intraplaque hemorrhage (IPH), lipid‐rich necrotic‐core (LRNC), and thin/ruptured fibrous cap (TRFC).

Statistical Tests

Diagnostic performance of the Neurovascular Coil Protocol was compared to the Surface Coil Protocol reference standard using receiver‐operating curves.

Results

For IPH, sensitivity, specificity, and area under the curve (AUC) of the Neurovascular Coil Protocol were 91.1% (95% confidence interval [CI] = 78.8–97.5%), 87.0% (95% CI = 66.4–97.2%), and 0.92, respectively. For LRNC without IPH sensitivity, specificity, and AUC were 73.3% (95% CI = 44.9–92.2%), 85.7% (95% CI = 67.3–96.0%), and 0.84, respectively. For TRFC, sensitivity, specificity, and AUC were 35.3% (95% CI = 14.2–61.7%), 97.6% (95% CI = 87.4–99.9%), and 0.66 respectively. Interobserver agreement for IPH, LRNC, and TRFC using the Neurovascular Coil Protocol were k = 0.87 (95% CI = 0.75–0.99), k = 0.54 (95% CI = 0.29–0.80), and k = 0.41 (95% CI = 0.08–0.74), respectively.

Data Conclusion

Our Neurovascular Coil Protocol has high sensitivity, specificity, and accuracy in identifying IPH and LRNC but is limited in assessment of TRFC.

Level of Evidence: 1

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2018;47:1264–1272.
Optimization of mucilage extraction from chia seeds (Salvia hispanica L.) using response surface methodology
Authors: Orifici Stefania C , Capitani Marianela I , Tomás Mabel C , Nolasco Susana M
Published: February 2018

BACKGROUND

Chia mucilage has potential application as a functional ingredient; advances on maximizing its extraction yield could represent a significant technological and economic impact for the food industry. Thus, first, the effect of mechanical agitation time (1–3 h) on the exudation of chia mucilage was analyzed. Then, response surface methodology was used to determine the optimal combination of the independent variables temperature (15–85 °C) and seed: water ratio (1: 12–1: 40.8 w/v) for the 2 h exudation that give maximum chia mucilage yield. Experiments were designed according to central composite rotatable design.

RESULTS

A second‐order polynomial model predicted the variation in extraction mucilage yield with the variables temperature and seed: water ratio. The optimal operating conditions were found to be temperature 85 °C and a seed: water ratio of 1: 31 (w/v), reaching an experimental extraction yield of 116 ± 0.21 g kg−1 (dry basis). The mucilage obtained exhibited good functional properties, mainly in terms of water‐holding capacity, emulsifying activity, and emulsion stability.

CONCLUSION

The results obtained show that temperature, seed: water ratio, and exudation time are important variables of the process that affect the extraction yield and the quality of the chia mucilage, determined according to its physicochemical and functional properties. © 2018 Society of Chemical Industry
A Retrospective Evaluation of Echocardiograms to Establish Normative Inferior Vena Cava and Aortic Measurements for Children Younger Than 6 Years
Authors: Stenson Erin K. , Punn Rajesh , Ramsi Musaab , Kache Saraswati
Published: February 2018

Objectives

The ability to plot the inferior vena cava (IVC) size on a normal curve for pediatric patients may prove beneficial. First, in patients with normal cardiac anatomy who present in shock, assessing IVC size may be valuable for evaluating the degree of dehydration. Second, in children with heart disease, understanding how a child's IVC size compares to normal could be particularly beneficial for patients with right heart disease. We sought to create normal curves for the IVC and aorta in children younger than 6 years.

Methods

Data were gathered from 347 echocardiograms of healthy children younger than 6 years in a retrospective study at a quaternary care children's hospital. From the subcostal long‐ and short‐axis images, maximum diameters in the transverse and longitudinal views were obtained for both the IVC and the aorta.

Results

Both IVC and aortic dimensions increased in a linear fashion and had excellent correlations with the body surface area, body mass, and height (IVC, r = 0.78–0.81; P < .0001; aorta, r = 0.82–0.86; P < .0001).

Conclusions

In children younger than 6 years, the IVC and aorta increase linearly as the children grow. Such normal curves will be beneficial for assessing a pediatric patient's hydration status or right heart function in patients with congenital heart disease.
Assessment of Right Atrium Function in Patients With Systemic Lupus Erythematosus With Different Pulmonary Artery Systolic Pressures by 2‐Dimensional Speckle‐Tracking Echocardiography
Authors: Sun Lihua , Wang Ying , Dong Yu , Song Shengda , Luo Runlan , Li Guangsen
Published: February 2018

Objectives

To assess right atrium (RA) function of patients with systemic lupus erythematosus (SLE) and pulmonary artery hypertension (PAH) by 2‐dimensional speckle‐tracking echocardiography.

Methods

Thirty matched healthy adults were selected as group A. Then, 102 patients with SLE were divided into 3 groups according to the severity of PAH. Group B included 37 patients without PAH (pulmonary artery [PA] systolic pressure ≤ 30 mm Hg); group C included 34 patients with PAH (PA systolic pressure of 30–50 mm Hg); and group D included 31 patients with PAH (PA systolic pressure ≥ 50 mm Hg). Parameters evaluated included RA maximum volume, minimum volume, preatrial contraction volume, passive ejection fraction (EF), and active EF. The global peak longitudinal systolic strain rate and early and late diastolic strain rates of the RA were obtained by 2‐dimensional speckle‐tracking echocardiography.

Results

No significant differences were found in all parameters between groups B and A (P > .05). The RA maximum volume, minimum volume, preatrial contraction volume, active EF, and late diastolic strain rate in groups C and D were significantly increased compared with those in groups A and B, and the parameters in group D were significantly higher than those in group C (P < .05). Although the RA passive EF, early diastolic strain rate, and systolic strain rate in groups C and D were significantly decreased compared with those in groups A and B, those in group D were significantly lower than those in group C (P < .05).

Conclusions

Two‐dimensional speckle‐tracking echocardiography could effectively assess RA function in patients with SLE who have different severities of PAH.
The digital library
Authors: Geleijnse Hans
Published: February 2018

Gives an overview of the current situation in the development of the Digital Library at Tilburg University, addressing positive experiences as well as problems, and focusing on the online provision of primary information to end–users, both of journal articles and of papers produced by the institution’s own researchers. The first results of the electronic use of our Elsevier journals are described, and the policy of libraries with respect to publishers considered.
Cutting‐edge endonasal surgical approaches to thyroid ophthalmopathy
Authors: Tyler Matthew A. , Zhang Caroline C. , Saini Alok T. , Yao William C.
Published: February 2018

Objective

Thyroid orbitopathy is a poorly understood extrathyroidal manifestation of Graves' disease that can cause disfiguring proptosis and vision loss. Orbital decompression surgery for Graves' orbitopathy (GO) can address both cosmetic and visual sequelae of this autoimmune condition. Endonasal endoscopic orbital decompression provides unmatched visualization and access to inferomedial orbital wall and orbital apex. This review examines the state of the art approaches employed in endonasal endoscopic orbital decompression for GO.

Methods

Review of literature evaluating novel surgical maneuvers for GO.

Results

Studies examining the efficacy of endonasal endoscopic orbital decompression are heterogenous and retrospective in design; however, they reveal this approach to be a safe and effective technique in the management of GO.

Conclusion

Subtle variations in endoscopic techniques significantly affect postsurgical outcomes and can be tailored to the specific clinical indication in GO making endonasal endoscopic decompression the most versatile approach available.

Level of Evidence

NA.
Coatable Photomobile Polymer Films Using Spring‐Like Photochromic Compounds
Authors: Kondo Mizuho , Makino Kotaro , Miyake Kazutoshi , Matsuo Yoshiaki , Fukae Ryohei , Kawatsuki Nobuhiro
Published: February 2018

Photoinduced macroscopic deformation behavior of crosslinked liquid‐crystalline polymer is induced in crosslinked N‐benzylideneaniline polymer films. The film is prepared by in situ polymer reaction using polymethacrylate‐containing phenylaldehyde side chains and o‐tolidine crosslinker. The film exhibits macroscopic bending upon exposure to UV light and then immediately reverts to the initial shape when the light is turned off. The bending behavior is strongly affected by the fabrication conditions; the changes in the macroscopic shape and photomechanical properties in response to UV light for the film prepared from a mixture solution are small, while those for the film prepared by top coating the crosslinker solution onto the prepolymer substrate are large.
Fully automatic segmentation and objective assessment of atrial scars for long‐standing persistent atrial fibrillation patients using late gadolinium‐enhanced MRI
Authors: Yang Guang , Zhuang Xiahai , Khan Habib , Haldar Shouvik , Nyktari Eva , Li Lei , Wage Ricardo , Ye Xujiong , Slabaugh Greg , Mohiaddin Raad , Wong Tom , Keegan Jennifer , Firmin David
Published: February 2018

Purpose

Atrial fibrillation (AF) is the most common heart rhythm disorder and causes considerable morbidity and mortality, resulting in a large public health burden that is increasing as the population ages. It is associated with atrial fibrosis, the amount and distribution of which can be used to stratify patients and to guide subsequent electrophysiology ablation treatment. Atrial fibrosis may be assessed noninvasively using late gadolinium‐enhanced (LGE) magnetic resonance imaging (MRI) where scar tissue is visualized as a region of signal enhancement. However, manual segmentation of the heart chambers and of the atrial scar tissue is time consuming and subject to interoperator variability, particularly as image quality in AF is often poor. In this study, we propose a novel fully automatic pipeline to achieve accurate and objective segmentation of the heart (from MRI Roadmap data) and of scar tissue within the heart (from LGE MRI data) acquired in patients with AF.

Methods

Our fully automatic pipeline uniquely combines: (a) a multiatlas‐based whole heart segmentation (MA‐WHS) to determine the cardiac anatomy from an MRI Roadmap acquisition which is then mapped to LGE MRI, and (b) a super‐pixel and supervised learning based approach to delineate the distribution and extent of atrial scarring in LGE MRI. We compared the accuracy of the automatic analysis to manual ground truth segmentations in 37 patients with persistent long‐standing AF.

Results

Both our MA‐WHS and atrial scarring segmentations showed accurate delineations of cardiac anatomy (mean Dice = 89%) and atrial scarring (mean Dice = 79%), respectively, compared to the established ground truth from manual segmentation. In addition, compared to the ground truth, we obtained 88% segmentation accuracy, with 90% sensitivity and 79% specificity. Receiver operating characteristic analysis achieved an average area under the curve of 0.91.

Conclusion

Compared with previously studied methods with manual interventions, our innovative pipeline demonstrated comparable results, but was computed fully automatically. The proposed segmentation methods allow LGE MRI to be used as an objective assessment tool for localization, visualization, and quantitation of atrial scarring and to guide ablation treatment.
‘Yams Have No Ears!’:Tekhne, Life and Images in Oceania
Authors: Coupaye Ludovic
Published: February 2018

This paper explores the imbrications between vital processes and technical processes in Oceania, from the angle of technical activities. Grounded in the ethnography of yam cultivation among the Abulës‐Speakers (‘Abelam’) of Papua New Guinea, it builds on previous critiques of the modernist bias sustaining concepts of ‘technology’ and ‘production’ to revaluate the analytical potential of the study of material activities and their ontogenetic properties as suggested by Gilbert Simondon. By paying attention to the temporality and the scale of practices, it suggests that the ethnography of techniques allows the unveiling of both emic dimensions of practices (or indigenous underlying theories of actions), and emic properties of entities in the world, be they living beings or artefacts. These dimensions and properties, to be tapped into and controlled, are thus made visible or elicited both within and through technical practices,viathe work of imagination. Thus, processes, vital, and/or technical, made visible through their performance or through their results, can take the shape of images, be they living beings or artefacts, presenting to society the possibility of reproduction and stability, without excluding their ontogenetic capacities.
Preparation and properties of permselective film coated with glutaraldehyde crosslinked polyvinyl alcohol/diethanolamine
Authors: Lu Li‐Xin , Wan Zhe , Lu Wan‐Qiu , Pan Liao , Ge Changfeng
Published: February 2018

The effect of glutaraldehyde on the properties of polyvinyl alcohol/diethanolamine permselective film was investigated. A new permselective film was prepared by coating low‐density polyethylene containing diatomaceous earth. In the coating solution, diethanolamine, glutaraldehyde, and polyvinyl alcohol were used as an amine carrier, a crosslinking agent and a substrate respectively. The effects of the amount of glutaraldehyde on the tensile properties, moisture permeability, thermal stability and the morphologies of permselective film were characterized. The influence of relative humidity on the permeability of permselective film was investigated. The results show that with the increasing amount of glutaraldehyde, the permeability coefficient of CO2/O2, tensile strength, and thermal stability increase gradually. However, water vapor permeability coefficient and elongation at break of permselective film decrease with the content of glutaraldehyde on the rise. When the content of glutaraldehyde is 0.7%, the selectivity coefficient of CO2/O2 is up to 9.23, and the tensile properties and moisture resistance are also in the high level. Based on the results obtained, it can be concluded that the crosslinked permselective film prepared in this study has good comprehensive properties, and the relative humidity has little influence on the permselective film. POLYM. COMPOS., 40:1061–1067, 2019. © 2018 Society of Plastics Engineers
Can a QED Photon Propagate Out of the Black‐Hole Horizon?
Authors: Emelyanov Viacheslav A.
Published: February 2018

We show at one‐loop approximation that the QED photon acquires a negative gauge‐invariant mass‐squared in the near‐horizon region of an evaporating Schwarzschild black hole. This result may imply that information about the inner structure of evaporating black holes is accessible, even without invoking the modification of the basic QFT and GR principles.
Indium‐Assisted Plasma‐Enhanced Low‐Temperature Growth of Silicon Oxide Nanowires
Authors: Khmel Sergey , Baranov Evgeniy , Barsukov Andrey , Zamchiy Alexandr , Zaikovskii Alexey , Maximovskiy Evgeniy , Gulyaev Dmitry , Zhuravlev Konstantin
Published: February 2018

The nanowires of the silicon oxide SiOx (x ≤ 2) are synthesized on an indium catalyst by the gas‐jet electron beam plasma chemical vapor deposition (GJ EBP CVD) method using a monosilane‐argon‐hydrogen mixture with the simultaneous supply of the oxygen into the vacuum chamber. The arrays of the aligned microropes (bundles) of nanowires are formed at the substrate temperatures of 200–335 °С. At the temperature of 160 °С the cocoon‐like structures of SiOx nanowires are synthesized. The obtained results are explained within the synthesis model suggested previously. The Fourier transform infrared (FTIR) transmittance spectra are recorded to study the chemical composition of the nanowires. It is shown that the nanowires synthesized at temperatures of 200–335 °С consist of SiOx with x = 1.93 ± 0.04. The arrays of the oriented microropes of the SiOx nanowires exhibit the intense photoluminescence at a room temperature with a maximum in a range of the energies from 2 to 3 eV. The photoluminescence spectra of the oriented microropes synthesized on silicon substrates with the indium catalyst are shifted toward lower energies from 2.7–2.8 to 2.4–2.5 eV at the changing growth temperatures from 200 to 335 °C.
Electronic Transport Properties in AlInGaN/AlGaN Heterostructures
Authors: Li Yao , Zhang Jinfeng , Xue Junshuai , Liu Guipeng , Quan Rudai , Duan Xiaoling , Zhang Jincheng , Hao Yue
Published: February 2018

The AlGaN‐channel III‐N heterostructure effect transistor (HFET) devices with high breakdown voltage and acceptable on‐resistance has shown great potential for next generation of power switching. The electronic transport property of two‐dimensional electron gases (2DEGs) in AlInGaN/AlGaN heterostructures is investigated for the first time, and the effects of the alloy disorder scattering from both the barrier layer and the channel layer are analyzed. The quaternary alloy composition dependences of the 2DEG density and mobility and the sheet resistance (positively proportional to the device on‐resistance) are studied in nearly lattice matched AlInGaN/Al0.2Ga0.8N heterostructures. The alloy composition ranges of the AlxInyGa1−x−yN barrier layer of 0.58 ≤ x ≤ 0.76 and 0 ≤ y ≤ 0.14 is found to be optimal in all aspects, which corresponds to the threshold voltage of −1.55 ∼ −6.24 V for an AlInGaN/Al0.2Ga0.8N HFET with a nickel gate. Moreover, the temperature dependence of 2DEG mobility in lattice‐matched AlInGaN/AlGaN heterostructures is discussed with various scattering models. The results show that the magnitudes of the mobility in the sample Al0.3In0.05Ga0.65N/Al0.05Ga0.95N, Al0.5In0.06Ga0.44N/Al0.2Ga0.8N, and Al0.8In0.06Ga0.14N/Al0.5Ga0.5N heterostructures reduces by 61%, 47%, and 37% with the temperature increasing from 300 to 600 K. Our research may provide some instructions for the application of AlInGaN/AlGaN heterojunction to high voltage power devices.
Local Piezoelectric Behavior of Potassium Sodium Niobate Prepared by a Facile Synthesis via Water Soluble Precursors
Authors: Senes Nina , Iacomini Antonio , Domingo Neus , Enzo Stefano , Mulas Gabriele , Cuesta‐Lopez Santiago , Garroni Sebastiano
Published: February 2018

Due to the ever‐increasing restrictions connected to the use of toxic lead‐based materials, the developing of lead‐free piezoceramics has become one of the most urgent tasks. In this context, potassium sodium niobate materials (KNN) have attracted a lot of interest as promising candidates due to their excellent piezo properties. For this reason, many efforts have been addressed to optimize the synthesis process now suffering by several drawbacks including the high volatilization of potassium and sodium at the conventional high temperature treatments and the use of expensive metal precursors. To overcome these issues, a new modified Pechini method to synthesize single phase K0.5Na0.5NbO3 powders, from water soluble metal precursors, is presented. Microstructural and structural parameters are characterized by X‐ray diffraction (XRD). Depending on the amount of citric acid added to the starting reagents, two pure single‐phase K0.5Na0.5NbO3 (2 g citric acid) and K0.3Na0.7NbO3 (0.2 g citric acid), respectively, are obtained with a good crystallinity at a moderate temperature of 500 °C. The piezo responses of the as calcined systems are tested by piezoresponse force microscopy (PFM). K0.5Na0.5NbO3 exhibits a much higher response with respect to the other phase, which relates to the larger crystallinity and to the chemical composition.
Houttuynia cordata extract increased systemic exposure and liver concentrations of metformin through OCTs and MATEs in rats
Authors: You Byoung Hoon , Chin Young‐Won , Kim Hojun , Choi Han Seok , Choi Young Hee
Published: February 2018

The synergistic activity of Houttuynia cordata ethanol extract (HCT) and metformin combination in diabetic rats has been previously reported, but the fundamental causes remain unsolved. Organic cation transporters (OCTs) and multidrug and toxin extrusion proteins (MATEs) transport metformin to the liver and kidneys. Therefore, pharmacological activity and systemic exposure of metformin in HCT–metformin combination were determined from pharmacokinetic change and glucose‐lowering activity using in vitro HEK‐293 cells expressing human OCTs or human MATEs and in vivo rats. HCT inhibited human OCT2 and human MATE1‐mediated metformin transports in vitro. In in vivo rats, treatment with HCT and metformin for 28 days in rats (28MH rats) reduced the rat Oct2‐mediated renal excretion of metformin and thereby the increased systemic exposure of metformin compared with only metformin‐treated rats for 28 days (28M rats). In 28MH rats, rat Oct1‐mediated metformin uptake into the liver was enhanced, leading to an improved glucose‐lowering effect without hypoglycaemia compared with 28M rats. There was no impairment of renal function in HCT and metformin treatments. These results suggest that HCT–metformin combination therapy is applicable in terms of efficacy and safety.
Catalpol provides a protective effect on fibrillary Aβ1–42‐induced barrier disruption in an in vitro model of the blood–brain barrier
Authors: Liu Chenyang , Chen Kang , Lu Yunwei , Fang Zhuyuan , Yu Guran
Published: February 2018

Excessive amyloid beta (Aβ) deposition in brain is mainly responsible for cell damage and blood–brain barrier (BBB) disruption in Alzheimer's disease (AD). Catalpol, an iridoid glucoside extracted from the root of Rehmannia glutinosa Libosch, has neuroprotective effect against AD. It is unclear whether catalpol has a protective effect on Aβ‐induced BBB leakage. We employed an immortalized endothelial cell line (bEnd.3) and astrocytes co‐culture to mimic a BBB model in vitro and investigated the effect of catalpol on BBB. We found that treatment with catalpol decreased BBB hyperpermeability induced by fibrillar Aβ1–42. Data from western blotting showed that catalpol prevented fibrillar Aβ1–42‐induced bEnd.3 cell apoptosis through mitochondria‐dependent and death receptor pathways; decreased the levels of matrix metalloproteinases (MMPs), MMP‐2, MMP‐9, and the receptor for advanced glycation end products; and increased the levels of tight junction proteins (ZO‐1, occludin, and claudin‐5), low‐density lipoprotein receptor‐related protein 1, and P‐glycoprotein in fibrillar Aβ1–42‐treated bEnd.3 cells. Moreover, catalpol also enhanced soluble Aβ efflux across the fibrillar Aβ1–42‐treated bEnd.3 cells BBB monolayer model. Altogether, our results suggest that catalpol alleviate fibrillar Aβ1–42‐induced BBB disruption, enhance soluble Aβ clearance, and offer a feasible therapeutic application in AD treatment.
5‐Hydroxyferulic acid methyl ester isolated from wasabi leaves inhibits 3T3‐L1 adipocyte differentiation
Authors: Misawa Naoki , Hosoya Takahiro , Yoshida Shuhei , Sugimoto Osamu , Yamada‐Kato Tomoe , Kumazawa Shigenori
Published: February 2018

To investigate the compounds present in wasabi leaves (Wasabia japonica Matsumura) that inhibit the adipocyte differentiation, activity‐guided fractionation was performed on these leaves. 5‐Hydroxyferulic acid methyl ester (1: 5‐HFA ester), one of the phenylpropanoids, was isolated from wasabi leaves as a compound that inhibits the adipocyte differentiation. Compound 1 suppressed the intracellular lipid accumulation of 3T3‐L1 cells without significant cytotoxicity. Gene expression analysis revealed that 1 suppressed the mRNA expression of 2 master regulators of adipocyte differentiation, PPARγ and C/EBPα. Furthermore, 1 downregulated the expression of adipogenesis‐related genes, GLUT4, LPL, SREBP‐1c, ACC, and FAS. Protein expression analysis revealed that 1 suppressed PPARγ protein expression. Moreover, to investigate the relationship between the structure and activity of inhibiting the adipocyte differentiation, we synthesized 12 kinds of phenylpropanoid analog. Comparison of the activity among 1 and its analogs suggested that the compound containing the substructure that possess a common functional group at the ortho position such as a catechol group exhibits the activity of inhibiting the adipocyte differentiation. Taken together, our findings suggest that 1 from wasabi leaves inhibits adipocyte differentiation via the downregulation of PPARγ.
Boost success of students facing housing insecurity
Authors: Hallett Ronald E. , Crutchfield Rashida
Published: February 2018

Homelessness likely affects a significant number of college students across the United States, according to an emerging body of research.
Discover 5 ways to develop a gratitude practice
Authors: Costa Karen
Published: February 2018

A growing body of research is looking at the positive impacts of gratitude. The Harvard Mental Health newsletter detailed the connections between gratitude practices and individual well‐being, employee motivation, happiness, and fundraising initiatives. Gratitude feels good, motivates us, makes us happier, increases our generosity, and is equally beneficial to both giver and receiver.
Did court give dismissed student opportunity to finish a semester?
Authors: Gelpi Aileen
Published: February 2018

University of Notre Dame students John Doe and Jane Roe began a tumultuous relationship in 2015.
Prepare for and manage challenging circumstances by embracing an approach that ‘CARES’
Authors: McCarthy Claudine
Published: February 2018

The nonrenewal or layoff of staff members. Cuts to budgets and programs. Proliferation in on‐campus mental health concerns. Political sabotage from colleagues. Increases in sexual misconduct reporting. The negative, divisive tone and tenor of campus climate and diversity issues.
Estimating the effect of a rare time‐dependent treatment on the recurrent event rate
Authors: Smith Abigail R. , Zhu Danting , Goodrich Nathan P. , Merion Robert M. , Schaubel Douglas E.
Published: February 2018

In many observational studies, the objective is to estimate the effect of treatment or state‐change on the recurrent event rate. If treatment is assigned after the start of follow‐up, traditional methods (eg, adjustment for baseline‐only covariates or fully conditional adjustment for time‐dependent covariates) may give biased results. We propose a two‐stage modeling approach using the method of sequential stratification to accurately estimate the effect of a time‐dependent treatment on the recurrent event rate. At the first stage, we estimate the pretreatment recurrent event trajectory using a proportional rates model censored at the time of treatment. Prognostic scores are estimated from the linear predictor of this model and used to match treated patients to as yet untreated controls based on prognostic score at the time of treatment for the index patient. The final model is stratified on matched sets and compares the posttreatment recurrent event rate to the recurrent event rate of the matched controls. We demonstrate through simulation that bias due to dependent censoring is negligible, provided the treatment frequency is low, and we investigate a threshold at which correction for dependent censoring is needed. The method is applied to liver transplant (LT), where we estimate the effect of development of post‐LT End Stage Renal Disease (ESRD) on rate of days hospitalized.
Liposome Crosslinked Polyacrylamide/DNA Hydrogel: a Smart Controlled‐Release System for Small Molecular Payloads
Authors: Lyu Danya , Chen Shanshan , Guo Weiwei
Published: February 2018

A novel stimuli‐responsive hydrogel system with liposomes serving as both noncovalent crosslinkers and functional small molecules carriers for controlled‐release is developed. Liposomes can crosslink polyacrylamide copolymers functionalized with cholesterol‐modified DNA motifs to yield a DNA hydrogel system, due to the hydrophobic interaction between cholesteryl groups and the lipid bilayer of liposomes. Functional information encoded DNA motifs on the polymer backbones endow the hydrogel with programmable smart responsive properties. In a model system, the hydrogel exhibits stimuli‐responsive gel‐to‐sol transformation triggered by the opening of DNA motifs upon the presence of a restriction endonuclease enzyme, EcoR I, or temperature change, realizing the controlled‐release of liposomes which are highly efficient carriers of active small molecules payloads. Two active molecules, 1,1‐dioctadecyl‐3,3,3,3‐tetramethylindodicarbocyanine perchlorate (DiIC18(5)) and calcein, are chosen as the hydrophobic and hydrophilic model payloads, respectively, to address the feasibility of the releasing strategy. Moreover, the hydrogel exhibits injectable property as well as self‐recovery behaviors.
Fall and Winter Microhabitat Use and Suitability for Spring Chinook Salmon Parr in a U.S. Pacific Northwest River
Authors: Favrot Scott D. , Jonasson Brian C. , Peterson James T.
Published: February 2018

Habitat degradation has been implicated as a primary threat to Pacific salmon Oncorhynchus spp. Habitat restoration and conservation are key toward stemming population declines; however, winter microhabitat use and suitability knowledge are lacking for small juvenile salmonids. Our objective was to characterize microhabitat use and suitability for spring Chinook Salmon Oncorhynchus tshawytscha parr during fall and winter. Using radiotelemetry techniques during October–February (2009–2011), we identified fall and winter microhabitat use by spring Chinook Salmon parr in Catherine Creek, northeastern Oregon. Tagged fish occupied two distinct gradient reaches (moderate and low). Using a mixed‐effects logistic regression resource selection function (RSF) model, we found evidence that microhabitat use was similar between free‐flowing and surface ice conditions. However, habitat use shifted between seasons; most notably, there was greater use of silt substrate and areas farther from the bank during winter. Between gradients, microhabitat use differed with greater use of large wood (LW) and submerged aquatic vegetation in the low‐gradient reach. Using a Bayesian RSF approach, we developed gradient‐specific habitat suitability criteria. Throughout the study area, deep depths and slow currents were most suitable, with the exception of the low‐gradient reach where moderate depths were optimal. Near‐cover coarse and fine substrates were most suitable in the moderate‐ and low‐gradient reaches, respectively. Near‐bank LW was most suitable throughout the study area. Multivariate principal component analyses (PCA) indicated co‐occurring deep depths supporting slow currents near cover were intensively occupied in the moderate‐gradient reach. In the low‐gradient reach, PCA indicated co‐occurring moderate depths, slow currents, and near‐bank cover were most frequently occupied. Our study identified suitable and interrelated microhabitat combinations that can guide habitat restoration for fall migrant and overwintering Chinook Salmon parr in Catherine Creek and potentially the Pacific Northwest.
Magnetic Mapping of Banded Iron Formation of Sandur Schist Belt, Dharwar Craton, India
Authors: Kumar K. Satish , Srinivas K. N. S. S. S. , Kumar V. Pradeep , Prasad P. Prabhakara , Seshunarayana T.
Published: February 2018

High ground magnetic anomalies are observed at western basin of the Sandur schist belt (SSB) near Muraripura village, Karnataka. Sources for these anomalies are inferred due to presence of exposed banded iron formations hosted by metabasalts, arenaous and argillaceous rocks associated with the Donimali Formation of the schist belt. Two varieties of BIF bands are observed in the study area viz. Band 1 and Band 2. The bands 1 and 2 are displaced by lateral strike-slip fault. Band 1 is dominantly composed of banded iron formation, rich in iron ore minerals and silica chert. Band 2 is largely composed of ferruginous quartzite and quartz arenites. Qualitative analysis of the magnetic data indicates that the study area can be divided into three lithologically important BIF/BQ formations. Spectral and quantitative analysis of the magnetic data indicates, the average depth of band 1 is 70 m and band 2 is 130 m. The magnetic data results are well correlated with chemical analysis of borehole and surface rock samples data.
Development of a Model to Identify the Flow at any Location of an Ungauged Stream for Selection of Sites for Small Hydel in the Kalimpong Subdivision of West Bengal
Authors: Paul Prabir Kumar , Das Santasmita
Published: February 2018

Before the implementation of any small scale hydropower scheme, it is essential to determine the availability of sufficient and reliable amount of water to make the scheme economically viable. The sites for small hydels are generally located in the inaccessible tracts of hilly regions. This hinders the proper evaluation of the site. The investments in the small hydels are also comparatively very low as compared to a big hydel power plant; as such not much of fund can be allocated to the initial site suitability decisions. Once a best site in a stream having suitable head has been identified then proper and detailed survey of the site could be undertaken for the construction of the plant. The streams on which small hydel plants are planned are mostly ungauged, which again poses a problem in identifying the amount of flow at certain location. In this work an attempt has been made to create a model for identification of flow at any location of a watershed. The two components of flow that is the base flow and runoff has been taken into consideration for calculating the flow. The base flow has been identified by direct measurement and run off has been delineated using the distributed curve number method. Finally a regression has been done to come to a generalized equation for determination of total flow at any point of a watershed in the Kalimpong subdivision.
Role of MineVue Radar for Proving Abandoned and Unapproachable Mine Galleries for the Safety of Surface Structures
Authors: Singh K. K. K. , Singh S. K. , Singh A. K. , Ghosh C. N. , Singh P. K.
Published: February 2018

During the pre-nationalisation period due to unscientific mining, large number of old workings exist below important structures at various coal fields in India. Mostly these old workings exist below National Highways and Railway track. These workings are generally at shallow depth. It has been observed that subsidence and pot holing are common in those areas. As a result the safety of vehicles and passenger trains plying over these areas endangered. Since the old workings are more than 60 years old in most of the cases the proper plan and survey documents are not available. So it is extremely difficult to exactly locate the underground mine workings/galleries/voids from the surface such that precautionary measures can be initiated for the safety of roads and railway tracks. Eastern Coalfields Limited (ECL) has indicated that there may be some old workings below the national highway (NH–2) near Dalmia colliery of Salanpur Area of ECL. The most sophisticated system, MineVue Radar was used for delineation of abandoned mine workings or mine galleries below NH-2. Two voids of size 1.8 m height at depth of 40 m and another of size 1.35 m height at a depth of 33.5 m were delineated and confirmed using direct core drilling method. After that, Mine management was informed about these voids to take precautionary measures for the safety of NH-2. Thus, this system has played an important role for the safety of important surface structures. This paper deals the application of MineVue radar system for delineation of mine galleries below NH-2.
Reconstruction of Paleoclimate and Environmental Fluctuations Since the Early Holocene Period Using Organic Matter and C:N Proxy Records: A Review
Authors: Lone Aasif , Fousiya A. A. , Shah Rayees , Achyuthan Hema
Published: February 2018

In this review, the shifts in organic matter (OM) accumulation and C:N ratios in lake sediments to reconstruct paleoclimate and paleo-environmental changes since the early Holocene period are presented. The C:N proxy data of total OM reflect wet climatic conditions during early Holocene (10 to 8.2 kyrs BP) due to enhanced southwest monsoon. This was followed by intermittent arid conditions during the mid and late Holocene period (8.2 to 2.8 kyr BP). Enhanced values of C:N ratio during middle to late Holocene (7.8-2.3 kyrs B.P) indicate periods with lower lake levels and minimum precipitation, while decreased C:N ratio point to stronger SW monsoon and expansion of the lakes. Further, C:N and δ13C results from the lake sediments reveal a detailed and continuous paleo-environmental changes in the relative sources of OM (allochthonous vs autochthonous). Proxy records using such natural archives have also been utilized to reconstruct past extreme events and environmental changes around the lake systems, such as causes for lake desiccation, hydrographic changes, alternations between C3 and C4 vegetation and historical disturbances in the catchment area since the early-late Holocene period coupled with the Indian summer monsoon.