bluuebunny/crossref_metadata_2025 huggingface dataset:
Porous polymer composite membrane based nanogenerator: A realization of self-powered wireless green energy source for smart electronics applications
Authors: Ghosh Sujoy Kumar , Sinha Tridib Kumar , Mahanty Biswajit , Jana Santanu , Mandal Dipankar
Published: November 2016

An efficient, flexible and unvaryingly porous polymer composite membrane based nanogenerator (PPCNG) without any electrical poling treatment has been realised as wireless green energy source to power up smart electronic gadgets. Owing to self-polarized piezo- and ferro-electretic phenomenon of in situ platinum nanoparticles (Pt-NPs) doped porous poly(vinylidenefluoride-co-hexafluoropropylene)–membrane, a simple, inexpensive and scalable PPCNG fabrication is highlighted. The molecular orientations of the -CH2/-CF2 dipoles that cause self-polarization phenomenon has been realized by angular dependent near edge X-ray absorption fine structure spectroscopy. The square-like hysteresis loop with giant remnant polarization, Pr ∼ 68 μC/cm2 and exceptionally high piezoelectric charge coefficient, d33 ∼ − 836 pC/N promises a best suited ferro- and piezo-electretic membrane. The PPCNG exhibits a high electrical throughput such as, ranging from 2.7 V to 23 V of open-circuit voltage (Voc) and 2.9 μA to 24.7 μA of short-circuit current (Isc) under 0.5 MPa to 4.3 MPa of imparted stress amplitude by periodic human finger motion. The harvested mechanical and subsequent electrical energy by PPCNG is shown to transfer wirelessly via visible and infrared transmitter-receiver systems, where 17% and 49% of wireless power transfer efficiency, respectively, has been realized to power up several consumer electronics.
Coal price fluctuations in China: Economic effects and policy implications
Authors: Song Malin , Wang Jianlin
Published: November 2016

The price of coal fluctuated widely in the past few years in China. It is widely believed that rising coal prices can push up the inflation; this affected the determination of the policy of controlling coal price. This paper examines whether the rising coal price determines inflation in China. Bootstrap correlation test indicates that the Consumer price index (CPI) is not always positively correlated to the coal price in preceding months. The Bootstrap Granger test shows that coal price Granger-causes the CPI with 4–6 lags. However, many regression coefficients in the Granger test are negative and significant, which is consistent with the result of the bootstrap correlation test and contradicts the cost-push theory. Based on the Vector autoregression (VAR) model, bootstrap impulse response analysis reveals that coal price affects the CPI, but the directions of the effects vary and cancel each other out over a long period. Therefore, we find no evidence that shows a rise in coal price leads to cost-push inflation. Electricity price regulations, the price filter effect in the industry chain, and the Fisher currency trading equation theory can be used to explain this phenomenon. Finally, we conclude that both coal prices and the CPI are caused by inflation (in addition to market liquidity) instead of being the cause.
Charge density wave phase transition on the surface of electrostatically doped multilayer graphene
Authors: Long Gen , Xu Shuigang , Zhang Ting , Wu Zefei , Wong Wing Ki , Han Tianyi , Lin Jiangxiazi , Cai Yuan , Wang Ning
Published: November 2016

We demonstrate that the charge density wave (CDW) phase transition occurs on the surface of electronically doped multilayer graphene when the Fermi level approaches the M points (also known as van Hove singularities where the density of states diverge) in the Brillouin zone of the graphene band structure. The occurrence of such CDW phase transitions is supported by both the electrical transport measurement and optical measurements in electrostatically doped multilayer graphene. The CDW transition is accompanied with the sudden change of graphene channel resistance at Tm = 100 K, as well as the splitting of Raman G peak (1580 cm−1). The splitting of Raman G peak indicates the lifting of in-plane optical phonon branch degeneracy, and the non-degenerate phonon branches are correlated to the lattice reconstructions of graphene—the CDW phase transition.
Haar wavelet solution of the MHD Jeffery-Hamel flow and heat transfer in Eyring-Powell fluid
Authors: Khan Najeeb Alam , Sultan Faqiha , Shaikh Amber , Ara Asmat , Rubbab Qammar
Published: November 2016

This study deals with the numerical investigation of Jeffery-Hamel flow and heat transfer in Eyring-Powell fluid in the presence of an outer magnetic field by using Haar wavelet method. Jeffery-Hamel flows occur in various practical situations involving flow between two non-parallel walls. Applications of such fluids in biological and industrial sciences brought a great concern to the investigation of flow characteristics in converging and diverging channels. A suitable similarity transformation is applied to transform the nonlinear coupled partial differential equations (PDEs) into nonlinear coupled ordinary differential equations (ODEs), which govern the momentum and heat transfer properties of the fluid. Due to the high nonlinearity of resulting coupled ODEs, the exact solution is unlikely. Thus, the solution is approximated using a numerical scheme based on Haar wavelets and the results are verified by comparing with 4th order Runge-Kutta results.
Development of a novel two-dimensional ultrasonically actuated polishing process
Authors: Song Dunlan , Zhao Ji , Ji Shijun , Zhou Xiaoqin
Published: November 2016

Components with super-smooth freeform surfaces are being applied more and more extensively in various fields. Among the valuable non-traditional finishing processes for generating super-smooth freeform surfaces that have been developed, the two-axis vibration assisted polishing process has attracted great attention from some scholars in recent years. However, in the existing two-axis vibration assisted polishing process, vibrational coupling occurs between the traverse and axial directions in the vibrating body and causes the actuating polishing tool to rotate, which limits the polishing effect. To solve the above-mentioned vibration coupling problem, herein we develop a novel two-dimensional ultrasonically actuated polishing process using two mutually perpendicular Lange in vibrators. Through theoretical analysis and experimental tests, the influences of the contact pressure, feed rate, and vibrational parameters on the material removal rate of the proposed polishing process were revealed. The experiments demonstrated that the polishing removal rate was greatly improved.
Spin-wave dispersion of nanostructured magnonic crystals with periodic defects
Authors: Zhang V. L. , Lim H. S. , Ng S. C. , Kuok M. H. , Zhou X. , Adeyeye A. O.
Published: November 2016

The spin-wave dispersions in nanostructured magnonic crystals with periodic defects have been mapped by Brillouin light scattering. The otherwise perfect crystals are one-dimensional arrays of alternating 460nm-wide Ni80Fe20 stripes and 40nm-wide air gaps, where one in ten Ni80Fe20 stripes is a defect of width other than 460 nm. Experimentally, the defects are manifested as additional Brillouin peaks, lying within the first and second bandgaps of the perfect crystal, whose frequencies decrease with increasing defect stripe width. Finite-element calculations, based on a supercell comprising one defect and nine perfect Py stripes, show that the defect modes are localized about the defects, with the localization exhibiting an approximate U-shaped dependence on defect size. Calculations also reveal extra magnon branches and the opening of mini-bandgaps, within the allowed bands of the perfect crystal, arising from Bragg reflections at the boundaries of the shorter supercell Brillouin zone. Simulated magnetization profiles of the band-edge modes of the major and mini-bandgaps reveal their different symmetries and localization properties. The findings could find application in microwave magnonic devices like single-frequency passband spin-wave filters.
Impact-initiated behavior and reaction mechanism of W/Zr composites with SHPB setup
Authors: Ren Huilan , Liu Xiaojun , Ning Jianguo
Published: November 2016

The dynamic compressive behavior of a hot pressed tungsten/zirconium (W/Zr) composite with a mass proportion of 34:64 (W:Zr) was experimentally investigated using a split Hopkinson pressure bar and a high-speed camera. The W/Zr composite has high strength but some brittle characteristics; when subjected to a strong enough impact loading, the sample is crushed, rapidly releasing high amounts of energy as a result. This impact-initiated reaction depends on the loading conditions, where a higher loading strain rate resulting a smaller fragment size. The Zr phase is involved in the reaction as the active component of the composite, and these fragments can be divided into small, medium, and large fragments with their reactions labeled as “fire ball,” “spark,” and “no react” respectively. A simple model is constructed to analyze the heat generated during plastic deformation based on yield stress, crack speed and the thermal properties of the brittle material. Our proposed model’s prediction of temperature increase at initiation may reach several hundred degrees Celsius.
Dielectric and magnetic characterizations of capacitor structures with an ionic liquid/MgO barrier and a ferromagnetic Pt electrode
Authors: Hayakawa D. , Obinata A. , Miwa K. , Ono S. , Hirai T. , Koyama T. , Chiba D.
Published: November 2016

The dielectric and magnetic properties of electric double layer (EDL) capacitor structures with a perpendicularly magnetized Pt/Co/Pt electrode and an insulating cap layer (MgO) are investigated. An electric field is applied through a mixed ionic liquid/MgO barrier to the surface of the top Pt layer, at which the magnetic moment is induced by the ferromagnetic proximity effect. The basic dielectric properties of the EDL capacitor are studied by varying the thickness of the MgO cap layer. The results indicate that the capacitance, i.e., the accumulated charge density at the Pt surface, is reduced with increasing the MgO thickness. From the MgO thickness dependence of the capacitance value, the effective dielectric constant of the ionic liquid is evaluated. Almost no electric field effect on the magnetic moment, the coercivity, or the Curie temperature is confirmed in the top Pt layer with the thickness of 1.3 nm, regardless of the presence or absence of the MgO cap layer, whereas the a clear change in the magnetic moment is observed when the top Pt layer is replaced by a Pd layer of 1.7 nm.
A possible high-mobility signal in bulk MoTe2: Temperature independent weak phonon decay
Authors: Li Titao , Zhang Zhaojun , Zheng Wei , Lv Yangyang , Huang Feng
Published: November 2016

Layered transition metal dichalcogenides (TMDs) have attracted great attention due to their non-zero bandgap for potential application in high carrier mobility devices. Recent studies demonstrate that the carrier mobility of MoTe2 would decrease by orders of magnitude when used for few-layer transistors. As phonon scattering has a significant influence on carrier mobility of layered material, here, we first reported temperature-dependent Raman spectra of bulk 2H-MoTe2 from 80 to 300 K and discovered that the phonon lifetime of both E12g and A1g vibration modes are independent with temperature. These results were explained by the weak phonon decay in MoTe2. Our results imply the existence of a carrier mobility higher than the theoretical value in intrinsic bulk 2H-MoTe2 and the feasibility to obtain MoTe2-based transistors with sufficiently high carrier mobility.
CH3NH3Cd0.875Pb0.125I3 perovskite as potential photovoltaic materials
Authors: Zhang Yuandi , Feng Jing
Published: November 2016

The band structure, electronic and optical properties of the perovskite CH3NH3CdxPb1-xI3 are predicted using density functional theory. When Cd content is not over Pb content, the band gap of CH3NH3CdxPb1-xI3 is larger than that of CH3NH3PbI3, and the smallest band gap appears in CH3NH3Cd0.875Pb0.125I3 compound. In the wavelength range of 500-800 nm, the optical absorption coefficients of three kinds of composition CH3NH3CdxPb1-xI3 (x=5,6,7) are much larger than those of CH3NH3PbI3. Compared to CH3NH3PbI3, the absorption coefficients of CH3NH3Cd0.875Pb0.125I3 increase averagely 3.54 times in the visible light spectrum and the latter can absorb much more solar energy in infrared range than the former. The CH3NH3Cd0.875Pb0.125I3 compound is exceptional candidates of photovoltaic materials.
A half-metallic half-Heusler alloy having the largest atomic-like magnetic moment at optimized lattice constant
Authors: Zhang R. L. , Damewood L. , Fong C. Y. , Yang L. H. , Peng R. W. , Felser C.
Published: November 2016

For half-Heusler alloys, the general formula is XYZ, where X can be a transition or alkali metal element, Y is another transition metal element, typically Mn or Cr, and Z is a group IV element or a pnicitide. The atomic arrangements within a unit-cell show three configurations. Before this study, most of the predictions of half-metallic properties of half-Heusler alloys at the lattice constants differing from their optimized lattice constant. Based on the electropositivity of X and electronegativity of Z for half-Heusler alloys, we found that one of the configurations of LiCrS exhibits half-metallic properties at its optimized lattice constant of 5.803Å, and has the maximum atomic-like magnetic moment of 5μB. The challenges of its growth and the effects of the spin-orbit effect in this alloy will be discussed.
Cultivar resistance offers the first opportunity for effective management of the emerging powdery mildew (Erysiphe cruciferarum) threat to oilseed brassicas in Australia
Authors: Uloth M. B. , You M. P. , Barbetti M. J.
Published: November 2016

Powdery mildew of brassicas, caused by Erysiphe cruciferarum, is an emerging threat to oilseed Brassica production in Australia. Resistance to powdery mildew was assessed in 112 current and historic Australian Brassica napus canola cultivars and five cultivars of B. juncea mustard cultivars under controlled environmental conditions. Only 18% of leaf area was infested by the end of the test on the most resistant cultivars, compared with means of up to 70% for the most susceptible cultivars as well as severe stem and pod infection. For B. napus, cultivars with the greatest potential for reducing the impact of powdery mildew in the field were Trooper, Bravo TT, Summit, Tumby, Narendra and Hyola 650TT, all ranked in the 10% of cultivars with the lowest leaf infestation (Area Under The Disease Progress Curve (AUDPC) <537) and with <10% of stem area infested. For B. juncea, the level of leaf infestation was lowest for Sahara CL and Xceed X121 CL (AUDPC 303 and 380 respectively), but the high levels of stem infestation (42% and 28% respectively) in these cultivars may reduce their usefulness in the field. The most resistant cultivars identified can be immediately deployed into regions where powdery mildew is prevalent, providing the canola industry with an immediate and effective option for management of this increasingly troublesome disease.
A remotely sensed pigment index reveals photosynthetic phenology in evergreen conifers
Authors: Gamon John A. , Huemmrich K. Fred , Wong Christopher Y. S. , Ensminger Ingo , Garrity Steven , Hollinger David Y. , Noormets Asko , Peñuelas Josep
Published: November 2016

Significance

Evergreen photosynthetic activity has been difficult to determine from remote sensing, causing errors in terrestrial photosynthetic carbon uptake models. Using a reflectance chlorophyll/carotenoid index (CCI) sensitive to seasonally changing chlorophyll/carotenoid pigment ratios, we demonstrate a method of tracking photosynthetic phenology in evergreen conifers. The CCI reveals seasonally changing photosynthetic rates and detects the onset of the growing season in evergreen foliage. This method could improve our understanding of changing photosynthetic activity in a warming climate, and could improve assessment of the evergreen component of the terrestrial carbon budget, which has been elusive.
Structural basis for DNA recognition by STAT6
Authors: Li Jing , Rodriguez Jose Pindado , Niu Fengfeng , Pu Mengchen , Wang Jinan , Hung Li-Wei , Shao Qiang , Zhu Yanping , Ding Wei , Liu Yanqing , Da Yurong , Yao Zhi , Yang Jie , Zhao Yongfang , Wei Gong-Hong , Cheng Genhong , Liu Zhi-Jie , Ouyang Songying
Published: November 2016

Significance

STAT6 is a transcription factor and plays a predominant role in IL-4/IL-13 and virus-mediated signaling pathways. Extensive studies have linked malfunctions of STAT6 to pathological features of asthma and cancer. Targeting the function of STAT6 has become an attractive therapy. Understanding the molecular mechanisms of STAT6 transcriptional regulation is still scarce. Here, we report the atomic-level structures of the phosphorylated STAT6 core fragment homodimer, both in DNA-free and complexed with N4 or N3 site DNA, uncovering both a larger dimer interface intersection angle and the unique residue H415 of STAT6 as important factors for discrimination of N4 from N3 site DNA. This study uncovers a dramatic conformational change in STAT6 dimer for recognizing and preferring N4 site DNA.
Transport efficiency of membrane-anchored kinesin-1 motors depends on motor density and diffusivity
Authors: Grover Rahul , Fischer Janine , Schwarz Friedrich W. , Walter Wilhelm J. , Schwille Petra , Diez Stefan
Published: November 2016

Significance

Molecular motors, such as kinesin-1, are essential molecules involved in active intracellular transport. Current mechanistic insights on transport by motors are mainly based on in vitro studies where the motors are bound to rigid substrates. However, when transporting membranous cargo under physiological conditions, multiple motors are often only loosely coupled via a lipid bilayer. In this study, we investigate how the motors’ transport efficiency is affected when bound to a lipid bilayer. In our reconstituted gliding motility assays, we show that membrane-anchored motors exhibit reduced transport efficiency due to slippage in the lipid bilayer. Notably, the efficiency increases at higher motor density and reduced membrane diffusivity, providing cells with an additional means of regulating the efficiency of cargo transport.
Dynamic updating of hippocampal object representations reflects new conceptual knowledge
Authors: Mack Michael L. , Love Bradley C. , Preston Alison R.
Published: November 2016

Significance

A cosmopolitan couple looking for a home may focus on trendy features. However, with news of a baby on the way, they must quickly learn which features make for a child-friendly home to conceptually reorganize their set of potential homes. We investigate how conceptual knowledge is updated in the brain when goals change and attention shifts to new information. By combining functional MRI with computational modeling, we find that object representations in the human hippocampus are dynamically updated with concept-relevant information during learning. We also demonstrate that when concept updating is most consequential, the hippocampus is functionally coupled with neocortex. Our findings suggest that the brain reorganizes when concepts change and provide support for a neurocomputational theory of concept formation.
Strength in diversity: multiple memories of the Soviet past in the Russian Communist Party (CPRF), 1993–2004
Authors: Kalashnikov Antony
Published: November 2016

This paper investigates collective memory of the Soviet experiment in the narratives of the Communist Party of the Russian Federation (CPRF), in the period of 1993–2004. My research finds that ideological differences within the CPRF led to the creation of multiple and contrasting depictions of the Soviet past in the discourse of its leaders. Challenging dominant assumptions, I argue that these differences did not conflict and undermine one another, but were structured to strengthen the public appeal of the CPRF. The paper adds empirical findings to the study of the CPRF and of collective memory at the (so far underdeveloped) level of public organizations. The paper also challenges the prevailing assumption that diverging historical narratives necessarily imply conflict and contestation.
Long-term survival and fate of the leg in de novo intermittent claudication
Authors: Kumakura Hisao , Kanai Hiroyoshi , Hojo Yoshiaki , Iwasaki Toshiya , Ichikawa Shuichi
Published: November 2016

Aims

The long-term life expectancy and fate of the leg, including progression rate to critical limb ischaemia (CLI), were analysed in de novo patients with intermittent claudication (IC).

Methods and results

A prospective cohort study was performed in 1107 patients with de novo IC. The endpoints were overall survival (OS), freedom from major adverse cardiovascular events (MACE), freedom from major adverse cardiovascular and limb events (MACLE), and fate of the leg. The 5-, 10-, 15-, and 20-year rates were 73.3, 47.8, 28.1, and 14.9% for OS, and 63.0, 35.6, 18.5, and 5.7% for freedom from MACE, respectively. In Cox multivariable analysis, body mass index, diabetes, haemodialysis, and C-reactive protein (CRP) level were correlated with OS (P < 0.05). Ankle brachial pressure index, diabetes, coronary artery disease, haemodialysis, and CRP level were independently correlated with freedom from MACE and MACLE. Statins improved mortality, MACE, and MACLE (P < 0.05). Revascularization did not improve mortality and MACE, and femoropopliteal revascularization increased MACLE (P < 0.05). There was no deterioration of claudication in 881 patients (79.6%). Worsening claudication was noted in 211 patients (14.8% per 5 years), and 15 patients (1.1% per 5 years) worsened to CLI. Diabetes and haemodialysis were independent predictors of CLI. A history of cerebral infarction and femoropopliteal revascularization tended to increase CLI.

Conclusions

Life expectancy in patients with IC was poor, but the rate of IC progression to CLI was low. Statins improved mortality and morbidity, revascularization did not improve mortality and MACE, and femoropopliteal revascularization reduced freedom from MACLE with a risk of CLI.
Progress of rechargeable lithium metal batteries based on conversion reactions
Authors: Xin Sen , Chang Zhiwen , Zhang Xinbo , Guo Yu-Guo
Published: November 2016

In this review, we focus on the conversion reaction in newly raised rechargeable lithium batteries instanced by lithium–sulfur and lithium–oxygen batteries. A comprehensive discussion is made on the fundamental electrochemistry and recent advancements in key components of both types of the batteries. The critical problems in the Li–S and Li–O2 conversion electrochemistry are addressed along with the corresponding improvement strategies, for the purpose of shedding light on the rational design of batteries to reach optimal performance.
Use of Nucleic Acid Amplification Tests in Tuberculosis Patients in California, 2010–2013
Authors: Peralta Gianna , Barry Pennan , Pascopella Lisa
Published: November 2016

Background

Nucleic acid amplification tests (NAATs) have been used as a diagnostic tool for tuberculosis (TB) in the United States for many years. We sought to assess NAAT use in TB patients in California during a period of time when NAAT availability increased throughout the world.

Methods

We conducted a retrospective review of surveillance data from 6051 patients with culture-confirmed pulmonary TB who were reported to the California TB registry during 2010–2013.

Results

Only 2336 of 6051 (39%) TB patients had a NAAT for diagnosis before culture results. Although 90% (N = 2101) with NAAT had positive test results, 9% (N = 217) had falsely negative NAAT results, and 0.8% (N = 18) had indeterminate NAAT results. The median time from specimen collection to TB treatment initiation was shorter when NAAT was used (3 vs 14 days, P < .0001), and patients with a positive NAAT result initiated treatment earlier than patients with a falsely negative result (1 vs 11 days from NAAT report, P < .0001). We confirmed the increased sensitivity of NAAT compared with acid-fast bacilli (AFB) smear microscopy in our study population; 92 of 145 AFB smear-negative patients had positive NAATs. Median time from specimen collection to NAAT result report differed by health jurisdiction, from 1 to 11 working days.

Conclusions

Increased use of NAATs in diagnosis of pulmonary TB could decrease the time-to-treatment initiation and consequently decrease transmission. However, differential use and access to NAAT may prevent full realization of NAAT benefits in California.
Intra-abdominal Infections: The Role of Anaerobes, Enterococci, Fungi, and Multidrug-Resistant Organisms
Authors: Marcus Gil , Levy Samuel , Salhab Ghaleb , Mengesha Bethlehem , Tzuman Oran , Shur Shira , Burke Erica , Mayeda Rebecca Cruz , Cochavi Lior , Perluk Idan , Zaidenstein Ronit , Lazarovitch Tsilia , Dadon Mor , Marchaim Dror
Published: November 2016

Background

Intra-abdominal infections (IAI) constitute a common reason for hospitalization. However, there is lack of standardization in empiric management of (1) anaerobes, (2) enterococci, (3) fungi, and (4) multidrug-resistant organisms (MDRO). The recommendation is to institute empiric coverage for some of these organisms in “high-risk community-acquired” or in “healthcare-associated” infections (HCAI), but exact definitions are not provided.

Methods

Epidemiological study of IAI was conducted at Assaf Harofeh Medical Center (May–November 2013). Logistic and Cox regressions were used to analyze predictors and outcomes of IAI, respectively. The performances of established HCAI definitions to predict MDRO-IAI upon admission were calculated by receiver operating characteristic (ROC) curve analyses.

Results

After reviewing 8219 discharge notes, 253 consecutive patients were enrolled (43 [17%] children). There were 116 patients with appendicitis, 93 biliary infections, and 17 with diverticulitis. Cultures were obtained from 88 patients (35%), and 44 of them (50%) yielded a microbiologically confirmed IAI: 9% fungal, 11% enterococcal, 25% anaerobic, and 34% MDRO. Eighty percent of MDRO-IAIs were present upon admission, but the area under the ROC curve of predicting MDRO-IAI upon admission by the commonly used HCAI definitions were low (0.73 and 0.69). Independent predictors for MDRO-IAI were advanced age and active malignancy.

Conclusions

Multidrug-resistant organism-IAIs are common, and empiric broad-spectrum coverage is important among elderly patients with active malignancy, even if the infection onset was outside the hospital setting, regardless of current HCAI definitions. Outcomes analyses suggest that empiric regimens should routinely contain antianaerobes (except for biliary IAI); however, empiric antienterococcal or antifungals regimens are seldom needed.
Virologic Failure and Human Immunodeficiency Virus Drug Resistance in Rural Cameroon With Regard to the UNAIDS 90-90-90 Treatment Targets
Authors: Boullé Charlotte , Guichet Emilande , Kouanfack Charles , Aghokeng Avelin , Onambany Benjamin , Ikaka Catherine Massama , Ngock Emile , Tsoumsta Landry , Msellati Philippe , Mpoudi-Ngolé Eitel , Peeters Martine , Delaporte Eric , Laurent Christian
Published: November 2016

Background

In rural Africa, data on virologic effectiveness of antiretroviral treatment (ART) are not sufficient to assess the gap with the UNAIDS 90-90-90 treatment targets. We investigated the prevalences of unsuppressed viral load and antiretroviral drug resistance and the profile of genotypic resistance mutations among patients routinely treated in rural Cameroon.

Methods

A cross-sectional study was performed in 2013–2014 among patients ≥15 years and on first-line ART for ≥6 months in a district hospital. Patients were offered free access to human immunodeficiency virus viral load testing. Genotypic drug resistance testing was done when the viral load was >1000 copies/mL. Multivariate logistic regression models were used to assess the relationship of unsuppressed viral load or antiretroviral drug resistance with sociodemographic and medical characteristics.

Results

Of 407 patients (women 74.9%, median age 41.8 years, median time on ART 29.2 months), 96 (23.6%; 95% confidence interval [CI], 19.5–28.0) had unsuppressed viral load and 74 (18.2%; 95% CI, 14.6–22.3) had antiretroviral drug resistance. The prevalences of unsuppressed viral load and resistance increased with time on ART, from 12.0% and 8.0% in the 6- to 12-month group to 31.3% and 27.1% in the >72-month group, respectively. All 74 patients with antiretroviral drug resistance were resistant to nonnucleoside reverse-transcriptase inhibitors, and 57 of them were also resistant to nucleoside reverse-transcriptase inhibitors.

Conclusions

Our estimations were among the highest observed in the west and central African region. The proportion of patients with virologic failure should be divided at least by 2 to reach the UNAIDS 90-90-90 treatment targets.
Improving Learner Handovers in Medical Education
Authors: Warm Eric J. , Englander Robert , Pereira Anne , Barach Paul
Published: November 2016

Multiple studies have demonstrated that the information included in the Medical Student Performance Evaluation fails to reliably predict medical students’ future performance. This faulty transfer of information can lead to harm when poorly prepared students fail out of residency or, worse, are shuttled through the medical education system without an honest accounting of their performance. Such poor learner handovers likely arise from two root causes: (1) the absence of agreed-on outcomes of training and/or accepted assessments of those outcomes, and (2) the lack of standardized ways to communicate the results of those assessments. To improve the current learner handover situation, an authentic, shared mental model of competency is needed; high-quality tools to assess that competency must be developed and tested; and transparent, reliable, and safe ways to communicate this information must be created.

To achieve these goals, the authors propose using a learner handover process modeled after a patient handover process. The CLASS model includes a description of the learner’s Competency attainment, a summary of the Learner’s performance, an Action list and statement of Situational awareness, and Synthesis by the receiving program. This model also includes coaching oriented towards improvement along the continuum of education and care. Just as studies have evaluated patient handover models using metrics that matter most to patients, studies must evaluate this learner handover model using metrics that matter most to providers, patients, and learners.
Creating a Cadre of Fellowship-Trained Medical Educators, Part II: A Formal Needs Assessment to Structure Postgraduate Fellowships in Medical Education Scholarship and Leadership
Authors: Jordan Jaime , Yarris Lalena M. , Santen Sally A. , Guth Todd A. , Rougas Steven , Runde Daniel P. , Coates Wendy C.
Published: November 2016

Purpose

Education leaders at the 2012 Academic Emergency Medicine Consensus Conference on education research proposed that dedicated postgraduate education scholarship fellowships (ESFs) might provide an effective model for developing future faculty as scholars. A formal needs assessment was performed to understand the training gap and inform the development of ESFs.

Method

A mixed-methods needs assessment was conducted of four emergency medicine national stakeholder groups in 2013: department chairs; faculty education/research leaders; existing education fellowship directors; and current education fellows/graduates. Descriptive statistics were reported for quantitative data. Qualitative data from semistructured interviews and free-text responses were analyzed using a thematic approach.

Results

Participants were 11/15 (73%) education fellowship directors, 13/20 (65%) fellows/graduates, 106/239 (44%) faculty education/research leaders, and a convenience sample of 26 department chairs. Department chairs expected new education faculty to design didactics (85%) and teach clinically (96%). Faculty education/research leaders thought new faculty were inadequately prepared for job tasks (83.7%) and that ESFs would improve the overall quality of education research (91.1%). Fellowship directors noted that ESFs provide skills, mentorship, and protected time for graduates to become productive academicians. Current fellows/graduates reported pursing an ESF to develop skills in teaching and research methodology.

Conclusions

Stakeholder groups uniformly perceived a need for training in education theory, clinical teaching, and education research. These findings support dedicated, deliberate training in these areas. Establishment of a structure for scholarly pursuits prior to assuming a full-time position will effectively prepare new faculty. These findings may inform the development, implementation, and curricula of ESFs.
Residency Placement Fever: Is It Time for a Reevaluation?
Authors: Gruppuso Philip A. , Adashi Eli Y.
Published: November 2016

The transition from undergraduate medical education to graduate medical education (GME) involves a process rooted in the final year of medical school. Students file applications through the Electronic Residency Application Service platform, interview with residency training (i.e., GME) programs from which they have received invitations, and generate a rank-ordered preference list. The National Resident Matching Program reconciles applicant and program rank lists with an eye towards matching students and GME programs. This process has effectively served generations of graduating medical students. However, the past several decades have seen an intensification of the residency placement process that is exemplified by an inexorable increase in the number of applications filed and number of interviews accepted and attended by each student. The authors contend that this trend has untoward effects on both applicants and departments that are home to GME programs. Relevant information in the peer-reviewed literature on the consequences and benefits of the intensification of the residency placement process is scant. The authors address factors that may contribute to the intensity of the residency placement process and the relative paucity of data. They propose approaches to reverse current trends, and conclude that any reevaluation of the process will have to include the generation of outcome data to afford medical educators the opportunity to explore changes in an evidence-based manner.
Seven Dirty Words: Hot-Button Language That Undermines Interprofessional Education and Practice
Authors: Cahn Peter S.
Published: November 2016

An increasingly common goal of health professions education is preparing learners to collaborate with the full range of members on a health care team. While curriculum developers have identified many logistical and conceptual barriers to interprofessional education, one overlooked factor threatens to undermine interprofessional education and practice: language. Language reveals the mental metaphors governing thoughts and actions. The words that faculty members and health care providers use send messages that can—consciously or not—undermine explicit lessons about valuing each member of the care team. Too often, word choices make visible hierarchies in health care that may contradict overt messages about collaboration.

In this Perspective, the author draws on his experience as an outsider coming to academic medicine, noticing that certain words triggered negative responses in colleagues from different professions. He reflects on some of the most charged (or hot-button) words commonly heard in health care and educational settings and suggests possible alternatives that have similar denotations but that also have more collaborative connotations. By exploring seven of these dirty words, the author intends to raise awareness about the unintended effects of word choices. Changing exclusionary language may help promote the adoption of new metaphors for professional relationships that will more easily facilitate interprofessional collaboration and reinforce the formal messages about collaborative practice aimed at learners.
Type I Cutaneous Meningioma (Rudimentary Meningocele) With Intradural Attachment to the Phylum Terminale
Authors: Mazloom Sean E. , Holliday Alex C. , Coman Garrett C. , Chavan Rahul N. , Kolodney Michael S. , Grider Douglas J.
Published: November 2016

Cutaneous meningiomas (CM) are a small subset of meningiomas, further classified into three subtypes. The authors present a 15-year-old male with a symptomatic congenital type I CM and describe the histopathological and immunohistochemical findings. To the authors' knowledge, this is the first report of an extraspinal lumbar type I CM with intradural attachment to the phylum terminale.
Update on abortion policy
Authors: Conti Jennifer A. , Brant Ashley R. , Shumaker Heather D. , Reeves Matthew F.
Published: November 2016

Purpose of review

To review the status of antiabortion restrictions enacted over the last 5 years in the United States and their impact on abortion services.

Recent findings

In recent years, there has been an alarming rise in the number of antiabortion laws enacted across the United States. In total, various states in the union enacted 334 abortion restrictions from 2011 to July 2016, accounting for 30% of all abortion restrictions since the legalization of abortion in 1973. Data confirm, however, that more liberal abortion laws do not increase the number of abortions, but instead greatly decrease the number of abortion-related deaths. Several countries including Romania, South Africa and Nepal have seen dramatic decreases in maternal mortality after liberalization of abortion laws, without an increase in the total number of abortions. In the United States, abortions are incredibly safe with very low rates of complications and a mortality rate of 0.7 per 100 000 women. With increasing abortion restrictions, maternal mortality in the United States can be expected to rise over the coming years, as has been observed in Texas recently.

Liberalization of abortion laws saves women's lives. The rising number of antiabortion restrictions will ultimately harm women and their families.
Moving Nursing Program Portfolio Assessment From Midterm to End of Program
Authors: Hickey Kari , Rossetti Jeanette , Oldenburg Nancy , Abendroth Maryann , Uhlken Connie , Musker Kathleen , Peters Bradley , Paramore Patricia
Published: November 2016

Portfolio assessment promotes a culture of evidence, evaluates program outcomes, and provides an opportunity to assess the acquisition of knowledge and skills that are not easily assessed by examinations and other traditional assessment methods in nursing curricula. The portfolio program of 1 Midwestern school of nursing recently moved portfolio assessment to the end of program. The process of this change including logistics, rubric development, and lessons learned is highlighted.
Fixation Stability and Viewing Distance in Patients with AMD
Authors: Tarita-Nistor Luminita , González Esther G. , Brin Taylor , Mandelcorn Mark S. , Scherlen Anne-Catherine , Mandelcorn Efrem D. , Steinbach Martin J.
Published: November 2016

Purpose

People with normal vision perform activities of daily living binocularly, while changing viewing distance frequently and effortlessly. Typically, in patients with age-related macular degeneration (AMD), fixation stability is recorded with monocular instruments at a fixed viewing distance (i.e. optical infinity) to determine the location and precision of the preferred retinal loci (PRLs)—the part of the functional retina that fulfills the role of a pseudo-fovea. Fixation stability recorded with these instruments has been related to performance on visual tasks at shorter viewing distances, although it is not known how viewing distance affects the precision of ocular motor control in these patients. This study examined whether viewing distance affects fixation stability during binocular and monocular viewing.

Methods

Thirty patients with bilateral AMD, 10 older controls, and 10 younger controls participated. Each patient’s better eye (BE) and worse eye (WE) were identified based on their visual acuity. Fixation stability was recorded with a binocular eye-tracker at three viewing distances (40 cm, 1 m, 6 m) in binocular and monocular (with BE and with WE) viewing conditions. Fixation stability was evaluated with a bivariate contour ellipse area.

Results

For the AMD group, there was no effect of viewing distance on fixation stability, regardless of viewing condition (i.e. binocular, monocular with the BE or with the WE). The same pattern of results was found for the two control groups.

Conclusions

Viewing distance does not affect fixation stability in patients with AMD. Fixation stability data recorded with an instrument at a fixed viewing distance can be related to performance on visual tasks at other viewing distances.
Differential Associations of Socioeconomic Status With Global Brain Volumes and White Matter Lesions in African American and White Adults: the HANDLS SCAN Study
Authors: Waldstein Shari R. , Dore Gregory A. , Davatzikos Christos , Katzel Leslie I. , Gullapalli Rao , Seliger Stephen L. , Kouo Theresa , Rosenberger William F. , Erus Guray , Evans Michele K. , Zonderman Alan B.
Published: November 2016

Objective

The aim of the study was to examine interactive relations of race and socioeconomic status (SES) to magnetic resonance imaging (MRI)–assessed global brain outcomes with previously demonstrated prognostic significance for stroke, dementia, and mortality.

Methods

Participants were 147 African Americans (AAs) and whites (ages 33–71 years; 43% AA; 56% female; 26% below poverty) in the Healthy Aging in Neighborhoods of Diversity across the Life Span SCAN substudy. Cranial MRI was conducted using a 3.0 T unit. White matter (WM) lesion volumes and total brain, gray matter, and WM volumes were computed. An SES composite was derived from education and poverty status.

Results

Significant interactions of race and SES were observed for WM lesion volume (b = 1.38; η
2 = 0.036; p = .028), total brain (b = 86.72; η
2 = 0.042; p < .001), gray matter (b = 40.16; η
2 = 0.032; p = .003), and WM (b = 46.56; η
2 = 0.050; p < .001). AA participants with low SES exhibited significantly greater WM lesion volumes than white participants with low SES. White participants with higher SES had greater brain volumes than all other groups (albeit within normal range).

Conclusions

Low SES was associated with greater WM pathology—a marker for increased stroke risk—in AAs. Higher SES was associated with greater total brain volume—a putative global indicator of brain health and predictor of mortality—in whites. Findings may reflect environmental and interpersonal stressors encountered by AAs and those of lower SES and could relate to disproportionate rates of stroke, dementia, and mortality.
Living on the edge of a shrinking habitat: the ivory gull,
Pagophila eburnea
, an endangered sea-ice specialist
Authors: Gilg Olivier , Istomina Larysa , Heygster Georg , Strøm Hallvard , Gavrilo Maria V. , Mallory Mark L. , Gilchrist Grant , Aebischer Adrian , Sabard Brigitte , Huntemann Marcus , Mosbech Anders , Yannic Glenn
Published: November 2016

The ongoing decline of sea ice threatens many Arctic taxa, including the ivory gull. Understanding how ice-edges and ice concentrations influence the distribution of the endangered ivory gulls is a prerequisite to the implementation of adequate conservation strategies. From 2007 to 2013, we used satellite transmitters to monitor the movements of 104 ivory gulls originating from Canada, Greenland, Svalbard-Norway and Russia. Although half of the positions were within 41 km of the ice-edge (75% within 100 km), approximately 80% were on relatively highly concentrated sea ice. Ivory gulls used more concentrated sea ice in summer, when close to their high-Arctic breeding ground, than in winter. The best model to explain the distance of the birds from the ice-edge included the ice concentration within approximately 10 km, the month and the distance to the colony. Given the strong links between ivory gull, ice-edge and ice concentration, its conservation status is unlikely to improve in the current context of sea-ice decline which, in turn, will allow anthropogenic activities to develop in regions that are particularly important for the species.
Diverse drug-resistant subpopulations of
Mycobacterium tuberculosis
are sustained in continuous culture
Authors: Ayabina Diepreye , Hendon-Dunn Charlotte , Bacon Joanna , Colijn Caroline
Published: November 2016

Drug resistance to tuberculosis (TB) has become more widespread over the past decade. As such, understanding the emergence and fitness of antibiotic-resistant subpopulations is crucial for the development of new interventions. Here we use a simple mathematical model to explain the differences in the response to isoniazid (INH) of
Mycobacterium tuberculosis
cells cultured under two growth rates in a chemostat. We obtain posterior distributions of model parameters consistent with data using a Markov chain Monte Carlo (MCMC) method. We explore the dynamics of diverse INH-resistant subpopulations consistent with these data in a multi-population model. We find that the simple model captures the qualitative behaviour of the cultures under both dilution rates and also present testable predictions about how diversity is maintained in such cultures.
From resource to female defence: the impact of roosting ecology on a bat's mating strategy
Authors: Günther Linus , Lopez Marlena D. , Knörnschild Mirjam , Reid Kyle , Nagy Martina , Mayer Frieder
Published: November 2016

With their extraordinary species richness and diversity in ecological traits and social systems, bats are a promising taxon for testing socio-ecological hypotheses in order to get new insights into the evolution of animal social systems. Regarding its roosting habits, proboscis bats form an extreme by occupying sites which are usually completely exposed to daylight (e.g. tree trunks, vines or rocks). This is accompanied by morphological and behavioural adaptations to remain cryptic in exposed day roosts. With long-term behavioural observations and genetic parentage analyses of individually marked proboscis bats, we assessed its social dispersion and male mating strategy during day and night. Our results reveal nocturnal male territoriality—a strategy which most closely resembles a resource-defence polygyny that is frequent also in other tropical bats. Its contrasting clumped social dispersion during the day is likely to be the result of strong selection for crypsis in exposed roosts and is accompanied by direct female defence in addition to male territoriality. To the best of our knowledge, such contrasting male mating strategies within a single day–night cycle have not been described in a vertebrate species so far and illustrate a possible evolutionary trajectory from resource-defence to female-defence strategy by small ecologically driven evolutionary steps.