bluuebunny/crossref_metadata_2025 huggingface dataset:
Erdheim–Chester Disease
Authors: Patil Mamatha , Jaiswal Deepak
Published: August 2016

Erdheim–Chester disease (ECD) is an extremely rare disorder that can affect many different organs of the body. This is an unusual form of non-Langerhans-cell histiocytosis. This is characterized by excessive production and accumulation of histiocytes. The normal function of the histiocytes is to fight infections. Histiocytes accumulate in the loose connective tissue of various organ systems of the body and cause thickening of tissues and may become dense and fibrotic. In the absence of successful treatment, the disease is debilitating and can result in multi-system organ failure. Erdheim–Chester disease is often described in the medical literature as an extremely rare1 entity. Erdheim–Chester disease usually presents in adults aged between 40 and 60 years. Here we present a case report of ECD in a 26-year-old young male patient with progressive course over a period of 4 years with symptoms suggestive of multi-organ involvement.

How to cite this article

Patil M, Jaiswal D. Erdheim–Chester Disease. J Med Sci 2015;1(3):55-57.
Squamous Cell Carcinoma under the Veil of a Trophic Ulcer in a Case of Hansen's Disease
Authors: Rahim Safal
Published: August 2016

Hansen's disease is seldom associated with trophic ulcers, which over a period of time when neglected has the potential for malignant transformation. In this case report, a 44-year-old male patient previously treated for Hansen's disease presented with non-healing plantar ulcer, who developed squamous cell carcinoma with metastasis in the lymph nodes. We highlight the importance of having a high degree of suspicion in each case as our patient was asymptomatic and repeated biopsies and lymph node Fine needle aspiration cytology (FNAC) were required to diagnosis.

How to cite this article

Rahim S. Squamous Cell Carcinoma under the Veil of a Trophic Ulcer in a Case of Hansen's Disease. J Med Sci 2015;1(3):60-61.
Postoperative Nausea and Vomiting in Day Care Patients: A Comparative Randomized Controlled Trial of Total Intravenous Anesthesia with Propofol, Air, and Oxygen vs Inhalation Anesthesia with Isoflurane and Nitrous Oxide
Authors: Sandhya A , Mamatha R , Banerjee Antara
Published: August 2016

Introduction

We compared the incidence of postoperative nausea and vomiting (PONV) after total intravenous anesthesia (TIVA) using propofol–air to inhalational anesthesia with isoflurane–nitrous oxide in day care patients at a tertiary care academic institution.

Materials and methods

We randomized 60 patients and assigned to either group I (inhalational anesthesia with isoflurane– nitrous oxide) or group II (TIVA with propofol–air). Incidence of PONV, use of anti-emetics, and duration of stay in the recovery were recorded for 72 hours by blinded observers.

Results

Total intravenous anesthesia reduced the PONV up to 72 hours by 27% among our patients (from 37 to 10%, p < 0.001). This effect was seen more in the early postoperative period. Overall, 13.3% of patients in the group I received antiemetic compared to 40% in group II. In our study, patients without PONV were discharged from the recovery room 15 minutes earlier after TIVA than after isoflurane and N2O anesthesia.

Conclusion

Total intravenous anesthesia with propofol and air resulted in a reduction of PONV compared with iso-flurane–nitrous oxide anesthesia. Overall, patients in group I required less rescue antiemetic, compared to group II. Total intravenous anesthesia resulted in shorter stay in the postoperative anesthetic care unit compared to isoflurane–N2O group.

How to cite this article

Sandhya A, Mamatha R, Banerjee A, Sahajananda H. Postoperative Nausea and Vomiting in Day Care Patients: A Comparative Randomized Controlled Trial of Total Intravenous Anesthesia with Propofol, Air, and OxygenvsInhalation Anesthesia with Isoflurane and Nitrous Oxide. J Med Sci 2015;1(4):63-68.
Infantile Hemangioma: An Overview
Authors: Dhanraj Prema
Published: August 2016

Infantile hemangiomas (IH) are benign vascular neoplasms that have a characteristic clinical course marked by early proliferation and followed by spontaneous involution. Hemangiomas are the most common tumors of infancy and usually are medically insignificant. The vast majority of infantile hemangiomas do not require any medical or surgical intervention. Treatment options for clinically significant hemangiomas include, laser surgery, surgical excision or Medication.

How to cite this article

Dhanraj P. Infantile Hemangioma: An Overview. J Med Sci 2015;1(4):69-71.
A Rare Case of Bicornuate Uterus with Embedded Intrauterine Contraceptive Device
Authors: Gayatri A , Prasad Nagendra
Published: August 2016

Early intrauterine contraceptive devices (IUCDs) like Lippes Loop were intended for long-term use until menopause and hence often retained for years, and many patients present well into menopause still bearing a Lippes Loop either deliberately or forgotten. We present a case of a 65-year-old postmenopausal female patient presented with complaints of spotting per vagina since 20 days, associated with white discharge per vagina. Ultrasound abdomen showed calcified endometrium with IUCD in the cervical canal. Hysteroscopy was done. As IUCD could be visualized but could not be removed, hence hysterectomy was done.

How to cite this article

Gayatri A, Nagarathnamma R, Prasad N. A Rare Case of Bicornuate Uterus with Embedded Intrauterine Contraceptive Device. J Med Sci 2015;1(4): 72-73.
Anesthetic Management of an Elderly Patient with Permanent Pacemaker posted for Fixation of Tibial and Radial Fracture
Authors: Karthik GS , Halgunaki Praveen , LNU Rangalakshmi
Published: August 2016

Cardiac patients with pacemaker presenting for noncardiac surgery pose a considerable challenge to the anesthesiologists. In the United States it is said that there are more than 500,000 patients with pacemaker and every year more than 115,000 devices are implanted. Intraoperative care of the pacemaker as well as understanding its anesthetic implication is crucial in the management of these high-risk patients. We hereby present a case of an 85-year-old male posted for plating of tibial fracture with k-wiring of radius fracture who had permanent cardiac pacemakerin situ.

How to cite this article

Halgunaki P, Karthik GS, Rangalakshmi, Sahajananda H. Anesthetic Management of an Elderly Patient with Permanent Pacemaker posted for Fixation of Tibial and Radial Fracture. J Med Sci 2015;1(4):77-79.
Regulated Lignin Structural Units and Soil Organic Carbon Content by Cowpea Peroxidase
Authors: Osuji Godson O. , Madu Wenceslaus C. , Duffus Eustace , Johnson Paul , Weerasooriya Aruna , Ampim Peter A. Y. , Carson Laura , South Sanique , Johnson Dwiesha , Fares Ali , Johnson Alton
Published: August 2016

Peroxidases participate in lignin biosynthesis, but there is no biochemical resolution between the structural units of lignin and soil organic carbon (SOC) contents. Black-eyed beans are staple high-protein foods for millions of at-risk populations in every continent. Its cultivation in semiarid zones could be leveraged to maximize SOC sequestration. Cowpea was treated with stoichiometric mixes of mineral nutrients. Peroxidase was electrophoretically purified from leaves, and assayed for o-dianisidine (guaiacyl units) and pyrogallol (p-hydroxyphenyl units) substrate specificities. Lignin, and SOC compositions were determined by gravimetry. Sulfate-treated cowpea produced the highest lignin (318.88 kg·ha-1) because the o-dianisidine maximum velocity (Vmax) value (0.36 µM·min-1·mg-1) was higher than that for the pyrogallol (0.08 µM·min-1·mg-1), but the SOC (64.75 kg·ha-1) was low due to the guaiacyl being higher than p-hydroxyphenyl units. Peroxidase Vmax value was low (0.12 µM·min-1·mg-1) for both substrates in the control cowpea, and accordingly lignin (268.44 kg·ha-1) and SOC (42.33 kg·ha-1) compositions were very low. The pyrogallol Vmax value (0.5 µM·min-1·mg-1) was lower than the o-dianisidine value (1.0 µM·min-1·mg-1) for KK-treated cowpea, and accordingly the lignin contents (227.4 kg·ha-1) possessed variable compositions of guaiacyl and p-hydroxyphenyl units, leading to very high SOC composition (214.56 kg·ha-1). The high SOC sequestration technology involving fertilization with stoichiometric mixes of mineral nutrients could enable limited resource farmers who cultivate cowpeas as cover crop in the Sahel to improve SOM while producing their staple crop.
Effects of Oat (Avena sativa) and Hairy Vetch (Vicia villosa) Cover Crops on Nitrate Leaching, Soil Water, and Maize Yield in Subtropical Islands in Japan
Authors: Omae Hide , Nagumo Fujio
Published: August 2016

We determined the effects of oat (Avena sativa) and hairy vetch (Vicia villosa) winter cover crops on subsequent maize growth, soil erosion, water run-off, and nitrate leaching. Separate or combined plots of oat and hairy vetch cover crops were grown in winter, and maize was subsequently planted in all plots in the following summer season. The half-recommended N fertilizer (50 kg ha-1) applied to zero-tillage maize produced the same biomass and yield as the control (i.e., natural fallow-maize with tillage and fertilizer application of 100 N kg ha-1) when cultivated after hairy vetch (9.6 t ha-1). In contrast, maize grown after oat showed 40.4% lower biomass and 65.4% lower yield. Compared to the control, runoff and soil erosion were 85.3-92.9% (P < 0.001) and 68.6-98.7% lower with cover crop mulch irrespective of cover crop species (P > 0.05), respectively. Cumulative nitrate leaching 60 cm below the soil surface was highest in the control, followed by (in descending order) hairy vetch-maize, hairy vetch + oat-maize, and oat-maize. NO3-N release showed a twin-peak pattern in hairy vetch-maize plots at 18 and 37 days after sowing (DAS). Meanwhile, a single peak was observed in the control at 32 DAS immediately after top dressing at 31 DAS. The synchrony of N supply and crop demand were better in hairy vetch-maize than oat-maize or conventional cultivation owing to rapid maize growth under lower rainfall conditions.
Anatomical Studies of Two Jatropha Species with Importance for Biodiesel Production
Authors: Tavecchio N. , Reinoso H. , Castiglione M. Ruffini , Spanò C. , Pedranzani H. E.
Published: August 2016

Jatropha curcas L. and Jatropha macrocarpa Griseb. (Euphorbiaceae) are perennial species adapted to marginal conditions not suitable for agriculture, and have been recently exploited for oil and biodiesel production. The anatomy of different organs in members of this family exhibits a wide range of variations. However, knowledge of anatomical features is still incomplete. The aim of the present work was to analyze the anatomical structure of stem, leaf and root of J. curcas and J. macrocarpa seedling cultivated in a greenhouse. Fixed samples were properly treated using triple stain hematoxylin, safranin and fast green. Primary roots were diarch and triarch in J. curcas, whereas in J. macrocarpa were diarch and the cortex showed parenchyma cells, larger in J. macrocarpa than J. curcas. Stem cortex was thicker in J. macrocarpa than in J. curcas. Both species had parenchyma cells with cystolith, chloroplasts, laticifers and starch granules, these being more abundant in J. macrocarpa. Leaves were characterized by dorsoventral anatomy, with the epiderm showing amphistomatic condition with high stomata density at the lower surface. Both Jatropha species had paracytic stomata. Druses and non-articulated branched laticifers were recorded in the mesophyll. Some of the different anatomical features of J. curcas and J. macrocarpa could explain the different tolerance to abiotic stress.
On the $O(1/k)$ Convergence Rate of He's Alternating Directions Method for a Kind of Structured Variational Inequality Problem
Authors: Xu Haiwen
Published: August 2016

The  alternating directions method for a kind of structured variational inequality problem (He, 2001) is an attractive method for structured monotone variational inequality problems. In each iteration, the subproblemsare  convex quadratic minimization problem with simple constraintsand a well-conditioned system of nonlinear equations that can be efficiently solvedusing classical methods. Researchers have recently described the convergence rateof projection and contraction methods for variational inequality problems andthe original ADM and its linearized variant. Motivated and inspired by researchinto the convergence rate of these methods, we provide a simple proof to show the $O(1/k)$ convergencerate of  alternating directions methods for structured monotone variational inequality problems (He, 2001).
Exosomal MicroRNAs Derived From Umbilical Mesenchymal Stem Cells Inhibit Hepatitis C Virus Infection
Authors: Qian Xijing , Xu Chen , Fang Shuo , Zhao Ping , Wang Yue , Liu Houqi , Yuan Wen , Qi Zhongtian
Published: August 2016

Hepatitis C virus (HCV) is a significant global public health problem, causing more than 350,000 deaths every year. Although the development of direct-acting antivirals has improved the sustained virological response rate in HCV patients, novel anti-HCV agents with higher efficacy as well as better tolerance and cheaper production costs are still urgently needed. Cell-based therapy, especially its unique and strong paracrine ability to transfer information to other cells via extracellular vesicles such as exosomes, has become one of the most popular therapeutic methods in recent years. In our study, exosomes secreted from umbilical mesenchymal stem cells (uMSCs), which are widely used in regenerative medicine, inhibited HCV infection in vitro, especially viral replication, with low cell toxicity. Our analysis revealed that microRNAs (miRNAs) from uMSC-derived exosomes (uMSC-Exo) had their unique expression profiles, and these functional miRNAs, mainly represented by let-7f, miR-145, miR-199a, and miR-221 released from uMSC-Exo, largely contributed to the suppression of HCV RNA replication. These four miRNAs possessed binding sites in HCV RNA as demonstrated by the target prediction algorithm. In addition, uMSC-Exo therapy showed synergistic effect when combined with U.S. Food and Drug Administration-approved interferon-α or telaprevir, enhancing their anti-HCV ability and thus improving the clinical significance of these regenerative substances for future application as optimal adjuvants of anti-HCV therapy.

Significance

This work reported, for the first time, the identification of stem cell-derived exosomes of antiviral activity. Umbilical mesenchymal stem cell-secreted exosomes inhibited hepatitis C virus infection through transporting a mixture of microRNAs complementing the viral genomes to the host cells. This finding provides insights and prospects for physiologically secreted substances for antiviral therapy.
Homozygous YME1L1 mutation causes mitochondriopathy with optic atrophy and mitochondrial network fragmentation
Authors: Hartmann Bianca , Wai Timothy , Hu Hao , MacVicar Thomas , Musante Luciana , Fischer-Zirnsak Björn , Stenzel Werner , Gräf Ralph , van den Heuvel Lambert , Ropers Hans-Hilger , Wienker Thomas F , Hübner Christoph , Langer Thomas , Kaindl Angela M
Published: August 2016

Mitochondriopathies often present clinically as multisystemic disorders of primarily high-energy consuming organs. Assembly, turnover, and surveillance of mitochondrial proteins are essential for mitochondrial function and a key task of AAA family members of metalloproteases. We identified a homozygous mutation in the nuclear encoded mitochondrial escape 1-like 1 gene YME1L1, member of the AAA protease family, as a cause of a novel mitochondriopathy in a consanguineous pedigree of Saudi Arabian descent. The homozygous missense mutation, located in a highly conserved region in the mitochondrial pre-sequence, inhibits cleavage of YME1L1 by the mitochondrial processing peptidase, which culminates in the rapid degradation of YME1L1 precursor protein. Impaired YME1L1 function causes a proliferation defect and mitochondrial network fragmentation due to abnormal processing of OPA1. Our results identify mutations in YME1L1 as a cause of a mitochondriopathy with optic nerve atrophy highlighting the importance of YME1L1 for mitochondrial functionality in humans.
TAK1 adaptor proteins, TAB2 and TAB3, link the signalosome to B‐cell receptor‐induced IKK activation
Authors: Shinohara Hisaaki , Yasuda Tomoharu , Kurosaki Tomohiro
Published: August 2016

Transforming growth factor‐β‐activated kinase (TAK)1‐binding proteins (TAB) activate nuclear factor‐κB by linking TAK1 to signaling molecules. We investigated the mechanisms underlying B‐cell receptor (BCR) signaling in TAB2‐ and TAB3‐deficient and TAB3 domain deletion mutant DT40 B cell lines. Loss of TAB2 and TAB3 abolished BCR‐induced inhibitor of κB kinase (IKK) activation and TAK1 binding to caspase recruitment domain membrane‐associated guanylate kinase protein (CARMA)1. Deletion of TAB3, coupling of ubiquitin conjugation to ER degradation, coiled‐coil, and zinc finger domains blocked IKK activation and association with CARMA1. Thus, TAB2 and TAB3 connect signaling molecules that activate IKK in BCR signaling.
Chromatin programming by developmentally regulated transcription factors: lessons from the study of haematopoietic stem cell specification and differentiation
Authors: Obier Nadine , Bonifer Constanze
Published: August 2016

Although the body plan of individuals is encoded in their genomes, each cell type expresses a different gene expression programme and therefore has access to only a subset of this information. Alterations to gene expression programmes are the underlying basis for the differentiation of multiple cell types and are driven by tissue‐specific transcription factors (TFs) that interact with the epigenetic regulatory machinery to programme the chromatin landscape into transcriptionally active and inactive states. The haematopoietic system has long served as a paradigm for studying the molecular principles that regulate gene expression in development. In this review article, we summarize the current knowledge on the mechanism of action of TFs regulating haematopoietic stem cell specification and differentiation, and place this information into the context of general principles governing development.
Interactions of meningococcal virulence factors with endothelial cells at the human blood–cerebrospinal fluid barrier and their role in pathogenicity
Authors: Simonis Alexander , Schubert‐Unkmeir Alexandra
Published: August 2016

The Gram‐negative extracellular bacterium Neisseria meningitidis is one of the most common aetiological agents of bacterial meningitis affecting predominantly young children worldwide. This bacterium is normally a quiescent coloniser of the upper respiratory tract, but in some individuals it enters the blood stream and causes invasive diseases, such as septicaemia and meningitis. Interactions of N. meningitidis with human endothelial cells are crucially involved in pathogencitiy, and great efforts have been made to understand these molecular interactions. The aim of this review article is to provide an overview of the interactions of meningococcal virulence factors with host endothelial cells at the blood–cerebrospinal fluid barrier.
Dissolved organic carbon uptake in streams: A review and assessment of reach‐scale measurements
Authors: Mineau Madeleine M. , Wollheim Wilfred M. , Buffam Ishi , Findlay Stuart E. G. , Hall Robert O. , Hotchkiss Erin R. , Koenig Lauren E. , McDowell William H. , Parr Thomas B.
Published: August 2016

Quantifying the role that freshwater ecosystems play in the global carbon cycle requires accurate measurement and scaling of dissolved organic carbon (DOC) removal in river networks. We reviewed reach‐scale measurements of DOC uptake from experimental additions of simple organic compounds or leachates to inform development of aquatic DOC models that operate at the river network, regional, or continental scale. Median DOC uptake velocity (vf) across all measurements was 2.28 mm min−1. Measurements using simple compound additions resulted in faster vf (2.94 mm min−1) than additions of leachates (1.11 mm min−1). We also reviewed published data of DOC bioavailability for ambient stream water and leaf leachate DOC from laboratory experiments. We used these data to calculate and apply a correction factor to leaf leachate uptake velocity to estimate ambient stream water DOC uptake rates at the reach scale. Using this approach, we estimated a median ambient stream DOC vf of 0.26 mm min−1. Applying these DOC vf values (0.26, 1.11, 2.28, and 2.94 mm min−1) in a river network inverse model in seven watersheds revealed that our estimated ambient DOC vf value is plausible at the network scale and 27 to 45% of DOC input was removed. Applying the median measured simple compound or leachate vf in whole river networks would require unjustifiably high terrestrial DOC inputs to match observed DOC concentrations at the basin mouth. To improve the understanding and importance of DOC uptake in fluvial systems, we recommend using a multiscale approach coupling laboratory assays, with reach‐scale measurements, and modeling.
Energetic particle imaging: The evolution of techniques in imaging high‐energy neutral atom emissions
Authors: Mitchell D. G. , Brandt P. C. , Westlake J. H. , Jaskulek S. E. , Andrews G. B. , Nelson K. S.
Published: August 2016

Energetic neutral atom imaging instruments have been flown on a variety of space missions to satisfy a variety of science requirements. In this paper we discuss the most recent developments that lead to improvements in energy range, angular resolution, and background rejection for the high‐energy range, as represented in the past by the Cassini magnetosphere imaging instrument Ion and Neutral Camera, the Imager for Magnetopause‐to‐Aurora Global Exploration (IMAGE) mission High‐Energy Neutral Atom instrument, and to some degree the IMAGE mission Medium‐Energy Neutral Atom instrument. The new approaches discussed here rely on the use of ultrathin foils without UV filters and on very high speed coincidence logic to reduce accidentals from intense background sources. We present laboratory results demonstrating an electrostatic design that meets the coincidence timing requirements, position, and scattering performance consistent with angular resolution (full width at half maximum) of ~2° for hydrogen above 10 keV and a hydrogen energy threshold ≤1 keV.
Field‐aligned currents in Saturn's magnetosphere: Local time dependence of southern summer currents in the dawn sector between midnight and noon
Authors: Hunt G. J. , Cowley S. W. H. , Provan G. , Bunce E. J. , Alexeev I. I. , Belenkaya E. S. , Kalegaev V. V. , Dougherty M. K. , Coates A. J.
Published: August 2016

We examine and compare the magnetic field perturbations associated with field‐aligned ionosphere‐magnetosphere coupling currents at Saturn, observed by the Cassini spacecraft during two sequences of highly inclined orbits in 2006/2007 and 2008 under late southern summer conditions. These sequences explore the southern currents in the dawn‐noon and midnight sectors, respectively, thus allowing investigation of possible origins of the local time (LT) asymmetry in auroral Saturn kilometric radiation (SKR) emissions, which peak in power at ~8 h LT in the dawn‐noon sector. We first show that the dawn‐noon field data generally have the same four‐sheet current structure as found previously in the midnight data and that both are similarly modulated by “planetary period oscillation” (PPO) currents. We then separate the averaged PPO‐independent (e.g., subcorotation) and PPO‐related currents for both LT sectors by using the current system symmetry properties. Surprisingly, we find that the PPO‐independent currents are essentially identical within uncertainties in the dawn‐dusk and midnight sectors, thus providing no explanation for the LT dependence of the SKR emissions. The main PPO‐related currents are, however, found to be slightly stronger and narrower in latitudinal width at dawn‐noon than at midnight, leading to estimated precipitating electron powers, and hence emissions, that are on average a factor of ~1.3 larger at dawn‐noon than at midnight, inadequate to account for the observed LT asymmetry in SKR power by a factor of ~2.7. Some other factors must also be involved, such as a LT asymmetry in the hot magnetospheric auroral source electron population.
Relativistic electron precipitation as seen by NOAA POES
Authors: Yahnin A. G. , Yahnina T. A. , Semenova N. V. , Gvozdevsky B. B. , Pashin A. B.
Published: August 2016

We performed a survey of relativistic electron precipitation (REP) events revealed by the Medium Energy Proton and Electron Detector instrument on board NOAA Polar‐orbiting Operational Environmental Satellites during a 38 day interval. We have divided the observed REP events into three groups with respect to the simultaneous observations of energetic (>30 keV) electron and proton precipitation. The first group consists of REP enhancements forming the isotropy zone at the poleward edge of trapped relativistic electron fluxes. These REP events are observed on the nightside, and they are, apparently, produced by isotropization process related to nonadiabatic motion of particles in the stretched magnetic field. The second group are the REP events related to simultaneous enhancements of energetic >30–300 keV electrons. These events have a wider magnetic local time range of occurrence with a maximum in the premidnight sector. They can be related to the interaction of electrons with waves whose possible nature is briefly discussed on the basis of comparison with the cold plasma density in the conjugated region of the equatorial plane. The third group consists of the REP events correlated with the burst‐like precipitation of >30–keV protons within an anisotropy zone, where the trapped flux dominates. These events are found in the dusk sector in association with enhanced cold plasma density in the conjugate equatorial magnetosphere. As is known, proton bursts within the anisotropy zone indicate the location of the electromagnetic ion cyclotron (EMIC) wave source. Such REP events can be due to scattering of the relativistic electrons by EMIC waves. However, we noted that some of these REP events are associated with precipitation of energetic electrons with low‐energy cutoff below 100 keV. We suggest that in such cases the electrons within a wide energy range are precipitated by other waves (probably, by plasmaspheric hiss).
Electric and magnetic radial diffusion coefficients using the Van Allen probes data
Authors: Ali Ashar F. , Malaspina David M. , Elkington Scot R. , Jaynes Allison N. , Chan Anthony A. , Wygant John , Kletzing Craig A.
Published: August 2016

ULF waves are a common occurrence in the inner magnetosphere and they contribute to particle motion, significantly, at times. We used the magnetic and the electric field data from the Electric and Magnetic Field Instrument Suite and Integrated Sciences (EMFISIS) and the Electric Field and Waves instruments (EFW) on board the Van Allen Probes to estimate the ULF wave power in the compressional component of the magnetic field and the azimuthal component of the electric field, respectively. Using L∗, Kp, and magnetic local time (MLT) as parameters, we conclude that the noon sector contains higher ULF Pc‐5 wave power compared with the other MLT sectors. The dawn, dusk, and midnight sectors have no statistically significant difference between them. The drift‐averaged power spectral densities are used to derive the magnetic and the electric component of the radial diffusion coefficient. Both components exhibit little to no energy dependence, resulting in simple analytic models for both components. More importantly, the electric component is larger than the magnetic component by one to two orders of magnitude for almost all L∗ and Kp; thus, the electric field perturbations are more effective in driving radial diffusion of charged particles in the inner magnetosphere. We also present a comparison of the Van Allen Probes radial diffusion coefficients, including the error estimates, with some of the previous published results. This allows us to gauge the large amount of uncertainty present in such estimates.
In situ stress state and strength in mudrocks
Authors: Casey Brendan , Germaine John T. , Flemings Peter B. , Fahy Brian P.
Published: August 2016

The stress state of mudrocks buried under uniaxial strain conditions is defined through a large number of laboratory triaxial tests performed on water‐saturated resedimented mudrocks from a diverse set of geologic backgrounds. Unique relationships are found between the horizontal stresses that develop during normal uniaxial compression (given by K0NC), critical state friction angle, and shear strength during undrained loading. Tests were performed over the effective stress range of 0.1 to 100 MPa. Smectite‐rich mudrocks display a more rapid reduction in shear strength with increasing effective stress, which corresponds with a more rapid increase in horizontal stresses. The relationship between horizontal stresses and critical state friction angle found in this study compares favorably with the well‐known correlation of Jâky (1948), which was developed for very low stresses, even for friction angle values as low as 11°. Results for one mudrock suggest that this relationship also applies to mudrocks sheared from an unloaded (overconsolidated) state. The correlation between friction angle and K0NC is independent of the stress path applied during the compression phase of a test. This is not the case for shearing under undrained conditions, however, and the application of a stress path that produces uniaxial compression is necessary to measure a reliable shear strength. Systematic variations in K0NC and strength properties reflect an overall change in the shape and orientation of a mudrock's yield surface with effective stress level. The results of this study can aid in estimating the in situ stress state and strength properties of mudrocks, and this will have significant impact on a range of geoscience and engineering problems.
Joint inversion of teleseismic and ambient noise Rayleigh waves for phase velocity maps, an application to Iceland
Authors: Harmon Nicholas , Rychert Catherine A.
Published: August 2016

We present a method for joint inversion of teleseismic and ambient noise Rayleigh wave data for phase velocity maps from 18 to 50 s period. We adapt the two‐plane wave method for teleseismic data to include ambient noise phase data. We apply the method to data from Iceland's ICEMELT and HOTSPOT arrays. Checkerboard tests show that the joint inversion improves phase velocity model recovery over methods that use the data sets independently, particularly at 18 s period. The addition of ambient noise data also extends resolution to shallower depths and shorter periods in comparison to previous teleseismic results beneath Iceland. We show there are significant differences in the phase velocity maps from the joint approach in comparison to other approaches, for instance, using only teleseismic data, only ambient noise data, or the mean of the two. The difference in phase velocities in turn affects the resulting shear velocity models. The advantage of the joint inversion is that it produces a single phase velocity map that satisfies both data sets simultaneously. Our phase velocity maps show a transition from low velocities centered beneath the main volcanic centers in Iceland at 18–25 s period, primarily crustal depths, to a low‐velocity region that traces the rift zones from the Reykjanes Ridge in the south to the Kolbeinsey Ridge in the north at 29–50 s period, greater depths. These results are consistent with previous studies, although with an extended and improved region of resolution, which extends further into the Atlantic and Arctic Ocean.
Evaluating the use of 1‐D transit time distributions to infer the mean state and variability of oceanic ventilation
Authors: Shao Andrew E. , Mecking Sabine , Thompson LuAnne , Sonnerup Rolf E.
Published: August 2016

An offline tracer transport model transport is used to simulate chlorofluorocarbon (CFCs), sulfur hexafluoride (SF6), oxygen, ideal age, and model transit time distributions (TTDs) to evaluate how well tracers can be used to constrain both the mean state and variability of oceanic ventilation. Using climatological transports, the two‐parameter 1‐D inverse Gaussian approximation of the model TTD is found to be an adequate representation of ventilation pathways within the parts of the subtropical gyres with simple ventilation dynamics, but a poor approximation for regions with large gradients in ideal age (i.e., near the base of the thermocline and the continental boundaries). TTDs inferred from CFC‐12 and SF6 using a Peclet number‐based lookup table approach yield poor representations of the model TTD with a consistent bias toward ventilation being strongly dominated by along‐isopycnal diffusion. In a run with variable circulation, ideal age is used to track changes in thermocline ventilation. Variability in both apparent oxygen utilization (AOU) and tracer‐inferred TTD mean ages inferred using CFC‐12 (assuming fixed Peclet number) and dual tracers (SF6 and CFC‐12) are well‐correlated to ideal age variability in most of the thermocline. Changes in AOU are correlated with ideal age variability in even more regions compared to the TTD ages both horizontally and vertically down to intermediate depths. Generally, when changes in TTD mean age and AOU agreed in sign, correlations of both with ideal age changes were positive indicating the usefulness of tracers in diagnosing ventilation changes.
Bomb‐produced radiocarbon in the western tropical Pacific Ocean: Guam coral reveals operation‐specific signals from the Pacific Proving Grounds
Authors: Andrews Allen H. , Asami Ryuji , Iryu Yasufumi , Kobayashi Donald R. , Camacho Frank
Published: August 2016

High‐resolution radiocarbon (14C) analyses on a coral core extracted from Guam, a western tropical Pacific island, revealed a series of early bomb‐produced 14C spikes. The typical marine bomb 14C signal—phase lagged and attenuated relative to atmospheric records—is present in the coral and is consistent with other regional coral records. However, 14C levels well above what can be attributed to air‐sea diffusion alone punctuate this pattern. This anomaly was observed in other Indo‐Pacific coral records, but the Guam record is unmatched in magnitude and temporal resolution. The Guam coral Δ14C record provided three spikes in 1954–1955, 1956–1957, and 1958–1959 that are superimposed on a normal 14C record. Relative to mean prebomb levels, the first peak rises an incredible ∼700‰ and remained elevated for ∼1.2 years. A follow up assay with finer resolution increased the peak by ∼300‰. Subsequent spikes were less intense with a rise of ∼35 and ∼70‰. Each can be linked to thermonuclear testing in the Pacific Proving Grounds at Bikini and Enewetak atolls in Operations Castle (1954), Redwing (1956), and Hardtack I (1958). These 14C signals can be explained by vaporization of coral reef material in the nuclear fireball, coupled with neutron activation of atmospheric nitrogen (14C production), and subsequent absorption of 14CO2 to form particulate carbonates of close‐in fallout. The lag time in reaching Guam and other coral records abroad was tied to ocean surface currents and modeling provided validation of 14C arrival observations.
Estimates of greenhouse gas and black carbon emissions from a major Australian wildfire with high spatiotemporal resolution
Authors: Surawski N. C. , Sullivan A. L. , Roxburgh S. H. , Polglase P. J.
Published: August 2016

Estimates of greenhouse gases and particulate emissions are made with a high spatiotemporal resolution from the Kilmore East fire in Victoria, Australia, which burnt approximately 100,000 ha over a 12 h period. Altogether, 10,175 Gigagrams (Gg) of CO2 equivalent (CO2‐e) emissions occurred, with CO2 (∼68%) being the dominant chemical species emitted followed by CH4 (∼17%) and black carbon (BC) (∼15%). About 63% of total CO2‐e emissions were estimated to be from coarse woody debris, 22% were from surface fuels, 7% from bark, 6% from elevated fuels, and less than 2% from tree crown consumption. To assess the quality of our emissions estimates, we compared our results with previous estimates which used the Global Fire Emissions Database version 3.1 (GFEDv3.1) and the Fire INventory from the National Center for Atmospheric Research version 1.0 (FINNv1), as well as Australia's National Inventory System (and its revision). The uncertainty in emission estimates was addressed using truncated Monte Carlo analysis, which derived a probability density function for total emissions from the uncertainties in each input. The distribution of emission estimates from Monte Carlo analysis was lognormal with a mean of 10,355 Gigagrams (Gg) and a ±1 standard deviation (σ) uncertainty range of 7260–13,450 Gg. Results were in good agreement with the global data sets (when using the same burnt area), although they predicted lower total emissions by 15–37% due to underestimating fuel consumed. Emissions estimates can be improved by obtaining better estimates of fuel consumed and BC emission factors. Overall, this study presents a methodological template for high‐resolution emissions accounting and its uncertainty, enabling a step toward process‐based emissions accounting to be achieved.
Enhancement of volcanism and geothermal heat flux by ice‐age cycling: A stress modeling study of Greenland
Authors: Stevens Nathan T. , Parizek Byron R. , Alley Richard B.
Published: August 2016

Ice‐age cycling of the Greenland ice sheet likely contributed to locally elevated subglacial geothermal heat fluxes (GHFs), based on recent thermal modeling. Borehole and geophysical data indicate higher GHF in some areas than suggested by current knowledge of underlying geology, particularly at the head of the Northeast Greenland Ice Stream. Changes in lithospheric loading during ice‐sheet growth and decay cycles produce large and geologically rapid changes in the effective stress state beneath and near the ice sheet. Oscillations in melt fraction from cyclic loading through multiple ice‐age cycles will enhance upward magma migration through the nonlinear increase of melt migration velocity with melt fraction. We simulate periodic ice‐sheet loading scenarios along an east‐west transect across central Greenland on an Elastic Lithosphere, Relaxed Asthenosphere Earth model. Under likely parameter ranges, deviatoric stresses in the elastic lithosphere across widespread regions are sufficiently high to meaningfully enhance dike emplacement and also allow vug‐wave propagation in some scenarios. Stress patterns migrate laterally in response to ice‐sheet dynamics, favoring multistage magma ascent. If melt occurs at depth, our modeling suggests that ice‐age cycling could help it migrate upward to shallow depth or erupt, contributing to the high observed GHF. Furthermore, shallow magma emplacement might feed hydrothermal systems exploiting enhanced faulting or fracturing from ice‐age cycling, adding to elevated GHF. The preglacial passage of the Iceland‐Jan Mayen hot spot could have sourced such magmas. Direct observations of these lithospheric processes needed to further constrain our models are limited, highlighting the value of more targeted geophysical studies informing future modeling.
Simulating effects of a wind‐turbine array using LES and RANS
Authors: Vanderwende Brian J. , Kosović Branko , Lundquist Julie K. , Mirocha Jeffrey D.
Published: August 2016

Growth in wind power production has motivated investigation of wind‐farm impacts on in situ flow fields and downstream interactions with agriculture and other wind farms. These impacts can be simulated with both large‐eddy simulations (LES) and mesoscale wind‐farm parameterizations (WFP). The Weather Research and Forecasting (WRF) model offers both approaches. We used the validated generalized actuator disk (GAD) parameterization in WRF‐LES to assess WFP performance. A 12‐turbine array was simulated using the GAD model and the WFP in WRF. We examined the performance of each scheme in both convective and stable conditions. The GAD model and WFP produced qualitatively similar wind speed deficits and turbulent kinetic energy (TKE) production across the array in both stability regimes, though the magnitudes of velocity deficits and TKE production levels were underestimated and overestimated, respectively. While wake growth slowed in the latter half of the WFP array as expected, wakes did not approach steady state by the end of the array as simulated by the GAD model. A sensitivity test involving the deactivation of explicit TKE production by the WFP resulted in turbulence levels within the array well that were below those produced by the GAD in both stable and unstable conditions. Finally, the WFP overestimated downwind power production deficits in stable conditions because of the lack of wake stabilization in the latter half of the array.
Single‐ion spectroscopy system for the 2S1/2(F = 0) − 2D3/2(F = 2) transition in 171Yb+
Authors: Imai Yasutaka , Nishi Tatsuya , Nishizaki Masatoshi , Kawajiri Sho , Muroki Yuto , Ikuta Rikizo , Matsumoto Kai , Kitano Masao , Sugiyama Kazuhiko
Published: August 2016

We report on our system and scheme for single‐ion spectroscopy of the
clock transition in 171Yb+. Spectroscopy of the clock transition requires decoupling of the
state from the laser cooling cycle. We investigate this decoupling of the
state by using independent light sources for driving of all the transitions between the hyperfine structures contained in the cooling and repumping transitions. We observe the carrier spectrum of the
magnetic‐insensitive transition with a spectral width of 380 Hz.
Physics‐based RF/microwave characterization of wave interactions within electrical connectors with partial insertion faults
Authors: Tokgöz Çağatay , Dardona Sameh
Published: August 2016

Electrical failures in avionics systems may result from connector faults. If fault precursors are not detected in advance, they may lead to hard failures such as open and short circuits that could ultimately result in fire or loss of flight critical systems. Therefore, It is crucial to detect, locate, and characterize fault precursors for timely preventive maintenance and mitigation before hard failures occur. In this paper, a physics‐based connector model consisting of multiple coaxial line sections with different characteristic impedances and lengths is proposed. Method of Moments (MoM) analyses were performed using commercial electromagnetic simulation software, FEKO, for transverse electric and magnetic (TEM) wave propagation through a connector. The physical parameters of the connector were optimized to match the measured S parameters for multiple insertion depths. The proposed models represent the connector for multiple insertion depths by varying only two length parameters at a time while other parameters are fixed. Insertion depth‐dependent resonant frequency shifts observed during measurement are also captured by the model over the full range of fully inserted to barely touching contacts. Hence, the models provide accurate representations of the connector and properly detect precursors to partial insertion faults.
Recent Advances in Doping of Molybdenum Disulfide: Industrial Applications and Future Prospects
Authors: Pham Viet Phuong , Yeom Geun Young
Published: August 2016

Owing to their excellent physical properties, atomically thin layers of molybdenum disulfide (MoS2) have recently attracted much attention due to their nonzero‐gap property, exceptionally high electrical conductivity, good thermal stability, and excellent mechanical strength, etc. MoS2‐based devices exhibit great potential for applications in optoelectronics and energy harvesting. Here, a comprehensive review of various doping strategies is presented, including wet doping and dry doping of atomically crystalline MoS2 thin layers, and the progress made so far for their doping‐based prospective applications is also discussed. Finally, several significant research issues for the prospects of doped‐MoS2 in industry, as a guide for 2D material community, are also provided.
Morphological Investigation of Poly(2‐aminothiazole) Prepared by Rapid Initiated Polymerization
Authors: Nabid Mohammad Reza , Bide Yasamin
Published: August 2016

The bulk and template‐free method to synthesize poly(2‐aminothiazole) (P2AT) and also morphological investigation by scanning electron microscopy are presented. The approach uses rapid initiated strategy by sodium hypochlorite as the oxidant and acetic acid, hydrochloric acid or camphorsulfonic acid as the dopant. Moreover, size controlling of P2AT nanoparticles was accomplished by employing different dopants, molar ratios of reactants, temperature and time, ranged from 20 to 380 nm in diameter. These nanoparticles can self‐assemble into plate‐like microstructures under certain conditions. According to the results, the amount of doping agent has a critical role in tailoring the nano‐ and microstructure of P2AT. The as‐obtained P2AT with plate‐like microstructure containing nanoparticles exhibited fluorescence emission at 430 nm. According to the nitrogen adsorption isotherm, the P2AT has a porous structure as the surface area was determined to be 38.54 m2 g−1 with the average pore size of 2.1 nm.
On the Effect of Prevalent Carbazole Homocoupling Defects on the Photovoltaic Performance of PCDTBT:PC71BM Solar Cells
Authors: Lombeck Florian , Komber Hartmut , Fazzi Daniele , Nava Diego , Kuhlmann Jochen , Stegerer Dominik , Strassel Karen , Brandt Josef , de Zerio Mendaza Amaia Diaz , Müller Christian , Thiel Walter , Caironi Mario , Friend Richard , Sommer Michael
Published: August 2016

The photophysical properties and solar cell performance of the classical donor–acceptor copolymer PCDTBT

(poly(N‐9′‐heptadecanyl‐2,7‐carbazole‐alt ‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole))) in relation to unintentionally formed main chain defects are investigated. Carbazole–carbazole homocouplings (Cbz hc) are found to significant extent in PCDTBT made with a variety of Suzuki polycondensation conditions. Cbz hc vary between 0 and 8 mol% depending on the synthetic protocol used, and are quantified by detailed nuclear magnetic resonance spectroscopy including model compounds, which allows to establish a calibration curve from optical spectroscopy. The results are corroborated by extended time‐dependent density functional theory investigations on the structural, electronic, and optical properties of regularly alternating and homocoupled chains. The photovoltaic properties of PCDTBT:fullerene blend solar cells significantly depend on the Cbz hc content for constant molecular weight, whereby an increasing amount of Cbz hc leads to strongly decreased short circuit currents JSC. With increasing Cbz hc content, JSC decreases more strongly than the intensity of the low energy absorption band, suggesting that small losses in absorption cannot explain the decrease in JSC alone, rather than combined effects of a more localized LUMO level on the TBT unit and lower hole mobilities found in highly defective samples. Homocoupling‐free PCDTBT with optimized molecular weight yields the highest efficiency up to 7.2% without extensive optimization.
Bismuth Interfacial Doping of Organic Small Molecules for High Performance n‐type Thermoelectric Materials
Authors: Huang Dazhen , Wang Chao , Zou Ye , Shen Xingxing , Zang Yaping , Shen Hongguang , Gao Xike , Yi Yuanping , Xu Wei , Di Chong‐an , Zhu Daoben
Published: August 2016

Development of chemically doped high performance n‐type organic thermoelectric (TE) materials is of vital importance for flexible power generating applications. For the first time, bismuth (Bi) n‐type chemical doping of organic semiconductors is described, enabling high performance TE materials. The Bi interfacial doping of thiophene‐diketopyrrolopyrrole‐based quinoidal (TDPPQ) molecules endows the film with a balanced electrical conductivity of 3.3 S cm−1 and a Seebeck coefficient of 585 μV K−1. The newly developed TE material possesses a maximum power factor of 113 μW m−1 K−2, which is at the forefront for organic small molecule‐based n‐type TE materials. These studies reveal that fine‐tuning of the heavy metal doping of organic semiconductors opens up a new strategy for exploring high performance organic TE materials.