bluuebunny/crossref_metadata_2025 huggingface dataset:
Ice nucleating particles in the Saharan Air Layer
Authors: Boose Yvonne , Sierau Berko , García M. Isabel , Rodríguez Sergio , Alastuey Andrés , Linke Claudia , Schnaiter Martin , Kupiszewski Piotr , Kanji Zamin A. , Lohmann Ulrike
Published: March 2016

Abstract. This study aims at quantifying the ice nucleation properties of desert dust in the Saharan Air Layer (SAL), the warm, dry and dust-laden layer that expands from North Africa to the Americas. By measuring close to the dust’s emission source, before aging processes during the transatlantic advection potentially modify the dust properties, the study fills a gap between in-situ measurements of dust ice nucleating particles (INPs) far away from the Sahara and laboratory studies of ground-collected soil. Two months of online INP concentration measurements are presented, which were part of the two CALIMA campaigns at the Izaña observatory in Tenerife, Spain (2373 m a.s.l.) in the summers of 2013 and 2014. INP concentrations were measured in the deposition and condensation mode at temperatures between 233 K and 253 K with the Portable Ice Nucleation Chamber (PINC). Additional aerosol information such as bulk chemical composition, concentration of fluorescent biological particles as well as the particle size distribution was used to investigate observed variations in the INP concentration. The concentration of INPs was found to range between 0.2 stdl−1 in the deposition mode and up to 2500 stdl−1 in the condensation mode at 241 K. It correlates well with the abundance of aluminum, iron, magnesium and manganese (R: 0.43–0.67) and less with that of calcium, sodium or carbonate. These observations are consistent with earlier results from laboratory studies which showed a higher ice nucleation efficiency of certain feldspar and clay minerals compared to other types of mineral dust. We find that an increase of ammonium sulfate, linked to anthropogenic emissions in upwind distant anthropogenic sources, mixed with the desert dust, has a small positive effect on the INP per dust mass ratio. Furthermore, the relative abundance of biological particles was found to be significantly higher in INPs compared to the ambient aerosol. Two common parameterization schemes for INP concentrations, which were derived mostly from atmospheric measurements far away from the Sahara, were found to predict more INPs based on the aerosol load than we observed in the SAL. Overall, this suggests that atmospheric aging processes in the SAL can lead to an increase in ice nucleation efficiency of mineral dust from the Sahara.
Different Pathways of the Formation of Highly Oxidized Multifunctional Organic Compounds (HOMs) from the Gas-Phase Ozonolysis of β-Caryophyllene
Authors: Richters Stefanie , Herrmann Hartmut , Berndt Torsten
Published: March 2016

Abstract. The gas-phase mechanism of the formation of highly oxidized multifunctional organic compounds (HOMs) from the ozonolysis of β-caryophyllene was investigated in a free-jet flow system at atmospheric pressure and a temperature of 295 ± 2 K. Reaction products, mainly highly oxidized RO2 radicals, containing up to 14 oxygen atoms were detected using chemical ionization – atmospheric pressure interface – time-of-flight mass spectrometry with nitrate and acetate ionization. These highly oxidized RO2 radicals react with NO, NO2, HO22 and other RO2 radicals under atmospheric conditions forming the first-generation HOM closed-shell products. Mechanistic information on the formation of the highly oxidized RO2 radicals are based on results obtained with isotopically labeled ozone (18O3) in the ozonolysis reaction and from H/D exchange experiments of acidic H atoms in the products. The experimental findings indicate that HOM formation in this reaction system is considerably influenced by the presence of a double bond in the RO2 radicals primarily formed from the β-caryophyllene ozonolysis. Three different reaction types for HOM formation can be proposed allowing to explain the detected main products, i.e. (i) the simple autoxidation, corresponding to the repetitive reaction sequence of intramolecular H-abstraction of a RO2 radical, RO2 → QOOH, and subsequent O2 addition forming a next peroxy radical, QOOH + O2 → R'O2, (ii) an extended autoxidation mechanism additionally involving the internal reaction of a RO2 radical with a double bond forming most likely an endoperoxide, and (iii) an extended autoxidation mechanism including CO2 elimination. The individual reaction steps of the reaction types (ii) and (iii) are uncertain at the moment. From the product analysis it can be followed that the simple autoxidation mechanism accounts only for about one third of the formed HOMs. Time-dependent measurements showed that the HOM formation proceeds at a timescale of 3 s or less under the concentration regime applied here. The new reaction pathways represent an extension of the mechanistic understanding of HOM formation via autoxidation in the atmosphere, as recently discovered from laboratory investigations on monoterpene ozonolysis.
Biogenic halocarbons from the Peruvian upwelling region as tropospheric halogen source
Authors: Hepach Helmke , Quack Birgit , Tegtmeier Susann , Engel Anja , Bracher Astrid , Fuhlbrügge Steffen , Galgani Luisa , Atlas Elliot , Lampel Johannes , Frieß Udo , Krüger Kirstin
Published: March 2016

Abstract. Halocarbons, halogenated short-chained hydrocarbons, are produced naturally in the oceans by biological and chemical processes. They are emitted from surface seawater into the atmosphere, where they take part in numerous chemical processes such as ozone destruction and the oxidation of mercury and dimethyl sulfide. Here we present oceanic and atmospheric halocarbon data for the Peruvian upwelling obtained during the M91 cruise onboard the research vessel Meteor in December 2012. Surface waters during the cruise were characterized by moderate concentrations of bromoform (CHBr3) and dibromomethane (CH2Br2) correlating with diatom biomass derived from marker pigment concentrations, which suggests this phytoplankton group as likely source. Concentrations measured for the iodinated compounds methyl iodide (CH3I) of up to 35.4 pmol L−1, chloroiodomethane (CH2ClI) of up to 58.1 pmol L−1 and diiodomethane (CH2I2) of up to 32.4 pmol L−1 in water samples were much higher than previously reported for the tropical Atlantic upwelling systems. Iodocarbons also correlated with the diatom biomass and even more significantly with dissolved organic matter (DOM) components measured in the surface water. Our results suggest a biological source of these compounds as significant driving factor for the observed large iodocarbon concentrations. Elevated atmospheric mixing ratios of CH3I (up to 3.2 ppt), CH2ClI (up to 2.5 ppt) and CH2I2 (3.3 ppt) above the upwelling were correlated with seawater concentrations and high sea-to-air fluxes. The enhanced iodocarbon production in the Peruvian upwelling contributed significantly to tropospheric iodine levels.
Ground-based remote sensing scheme for monitoring aerosol–cloud interactions
Authors: Sarna Karolina , Russchenberg Herman W. J.
Published: March 2016

Abstract. A new method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of the change of the cloud droplet size due to the change in the aerosol concentration. We use high-resolution measurements from a lidar, a radar and a radiometer, which allow us to collect and compare data continuously. This method is based on a standardised data format from Cloudnet and can be implemented at any observatory where the Cloudnet data set is available. Two example case studies were chosen from the Atmospheric Radiation Measurement (ARM) Program deployment on Graciosa Island, Azores, Portugal, in 2009 to present the method. We use the cloud droplet effective radius (re) to represent cloud microphysical properties and an integrated value of the attenuated backscatter coefficient (ATB) below the cloud to represent the aerosol concentration. All data from each case study are divided into bins of the liquid water path (LWP), each 10 g m−2 wide. For every LWP bin we present the correlation coefficient between ln re and ln ATB, as well as ACIr (defined as ACIr = −d ln re∕d ln ATB, change in cloud droplet effective radius with aerosol concentration). Obtained values of ACIr are in the range 0.01–0.1. We show that ground-based remote sensing instruments used in synergy can efficiently and continuously monitor aerosol–cloud interactions.
The importance of freshwater systems to the net exchange of atmospheric carbon dioxide and methane with rapidly changing high Arctic landscapes
Authors: Emmerton Craig A. , St. Louis Vincent L. , Lehnherr Igor , Graydon Jennifer A. , Kirk Jane L. , Rondeau Kimberly J.
Published: March 2016

Abstract. A warming climate is rapidly changing the distribution and exchanges of carbon within high Arctic ecosystems. Few data exist, however, which quantify exchange of both carbon dioxide (CO2) and methane (CH4) between the atmosphere and freshwater systems, or estimate freshwater contributions to total catchment exchange of these gases, in the high Arctic. During the summers of 2005 and 2007–2012, we quantified CO2 and CH4 concentrations in, and atmospheric exchange with, common freshwater systems in the high Arctic watershed of Lake Hazen, Nunavut, Canada. We identified four types of biogeochemically-distinct freshwater systems in the watershed, however mean CO2 concentrations (21–28 μmol L−1) and atmospheric exchange (−0.013–0.046 g C-CO2 m−2 d−1) were similar between these systems. Seasonal flooding of ponds bordering Lake Hazen generated considerable CH4 emissions to the atmosphere (0.008 g C-CH4 m−2 d−1), while all other freshwater systems were minimal emitters of this gas (< 0.001 g C-CH4 m−2 d−1). Measurements made on terrestrial landscapes in the same watershed between 2008–2012 determined that the near-barren polar semidesert was a very weak consumer of atmospheric CO2 (−0.004 g C-CO2 m−2 d−1), but an important consumer of atmospheric CH4 (−0.001 g C-CH4 m−2 d−1). Alternatively, meadow wetlands were very productive consumers of atmospheric CO2 (−0.96 g C-CO2 m−2 d−1) but relatively weak emitters of CH4 to the atmosphere (0.001 g C-CH4m−2 d−1). When using ecosystem-cover classification mapping, we found that freshwaters were unimportant contributors to total watershed carbon exchange, in part because they covered less than 10 % of total cover in the watershed. High Arctic watersheds are experiencing warmer and wetter climates than in the past, which may have implications for the net uptake of carbon greenhouse gases by currently underproductive polar semidesert and freshwater systems.
Circulation and oxygenation of the glacial South China Sea
Authors: Kao Shuh-Ji , Chiang Tzu-Ling , Li Da-Wei , Hsin Yi-Chia , Zheng Li-Wei , Yang Jin-Yu Terence , Hsu Shih-Chieh , Wu Chau-Ron , Dai Minhan
Published: March 2016

Abstract. Degree of oxygenation in intermediate water modulates the downward transferring efficiency of primary productivity (PP) from surface water to deep water for carbon sequestration, consequently, the storage of nutrients versus the delivery and sedimentary burial fluxes of organic matter and associated biomarkers. To better decipher the PP history of the South China Sea (SCS), appreciation about the glacial-interglacial variation of the Luzon Strait (LS) throughflow, which determines the mean residence time and oxygenation of water mass in the SCS interior, is required. Based on a well-established physical model, we conducted a 3-D modeling exercise to quantify the effects of sea level drop and monsoon wind intensity on glacial circulation pattern, thus, to evaluate effects of productivity and circulation-induced oxygenation on the burial of organic matter. Under modern climatology wind conditions, a 135 m sea level drop results in a greater basin closeness and a ~ 23 % of reduction in the LS intermediate westward throughflow, consequently, an increase in the mean water residence time (from 19 to 23 year). However, when the wind intensity was doubled during glacial low, the throughflow restored largely to reach a similar residence time (18.4 years) as today regardless its closeness. Comparing with present day SCS, surface circulation pattern in glacial model exhibits (1) stronger upwellings at the west off Luzon Island and the east off Vietnam, and (2) an intensified southwestward jet current along the western boundary of the SCS basin. Superimposed hypothetically by stronger monsoon wind, the glacial SCS conditions facilitate greater primary productivity. Manganese, a redox sensitive indicator, in IMAGES core MD972142 at southeastern SCS revealed a relatively reducing environment in glacial periods. Considering the similarity in the mean water residence time between modern and glacial cases, the reducing environment of the glacial southeastern SCS was thus ascribed to a productivity-induced rather than ventilation-induced consequence.
Error assessment of satellite-derived lead fraction in the Arctic
Authors: Ivanova Natalia , Rampal Pierre , Bouillon Sylvain
Published: March 2016

Abstract. Leads within consolidated sea ice control heat exchange between the ocean and the atmosphere during winter, thus constituting an important climate parameter. These narrow elongated features occur when sea ice is fracturing under the action of wind and currents, reducing the local mechanical strength of the ice cover, which in turn impact the sea ice drift pattern. This creates a high demand for a high-quality lead fraction (LF) data set for sea ice model evaluation, initialization, and for the assimilation of such data in regional models. In this context, an available LF data set retrieved from satellite passive microwave observations (Advanced Microwave Scanning Radiometer – Earth Observing System, AMSR-E) is of great value, which has been providing pan-Arctic light- and cloud-independent daily coverage since 2002. In this study errors in this data set are quantified using accurate LF estimates retrieved from Synthetic Aperture Radar (SAR) images employing a threshold technique. A consistent overestimation of LF by a factor of 2–4 is found in the AMSR-E LF product. It is shown that a simple adjustment of the upper tie point used in the method to estimate the LF can reduce the pixel-wise error by a factor of 2 on average. Applying such an adjustment to the full data set may thus significantly increase the quality and value of the original data set.
Persistence and Variability of Ice Stream Grounding Lines on Retrograde Bed Slopes
Authors: Robel Alexander  A. , Schoof Christian , Tziperman Eli
Published: March 2016

Abstract. In many ice streams, basal resistance varies in space and time due to the dynamically-evolving properties of subglacial till. These variations can cause internally-generated oscillations in ice stream flow. However, the potential for such variations in basal properties are not considered by conventional theories of grounding line stability on retrograde bed slopes, which assume that bed properties are static in time. Using a numerical flowline model, we show how internally-generated, transient variations in ice stream state interact with retrograde bed slopes. In contrast to predictions from the theory of the marine ice sheet instability, our simulated grounding line is able to persist and reverse direction of migration on a retrograde bed when undergoing oscillations in the grounding line position. In turn, the presence of a retrograde bed may also suppress or reduce the amplitude of internal oscillations in ice stream state. We explore the physical mechanisms responsible for these behaviors and discuss the implications for observed grounding line migration in West Antarctica.
A tecnologia e a cultura de informação como espaço de pesquisa para a ciência
Authors: Lins Greyciane Souza
Published: March 2016

Reflete sobre a cultura da informação na internet e suas interpretações científicas. O objetivo é identificar áreas de estudos de cultura da informação do ponto de vista da comunicação e da tecnologia. A partir de uma revisão bibliográfica e descritiva, esboça conceitos de informação e cultura de sob o enfoque de pensamentos históricos e contemporâneos. Conclui que a ciência da informação está implícita nos estudos de cultura da informação por uma perspectiva acadêmica interdisciplinar.
Impact of rouble’s depreciation on Russian overnight stays in Finnish regions and cities
Authors: Falk Martin , Vieru Markku
Published: March 2016

This article investigates how the depreciation of the Russian rouble against the euro has affected Russian tourism demand in Finnish regions and cities. Using dynamic panel data models, the authors find that the elasticity of Russian tourists’ overnight hotel stays with respect to exchange rates is significantly larger than 1 (approximately 1.6) in absolute terms, indicating that Russian tourists are highly sensitive to changes in exchange rates. There is some evidence that the sensitivity of Russian tourism demand increased following the introduction of economic sanctions in August 2014. The sensitivity of tourism demand to exchange rate changes differs highly across regions and cities, with higher elasticities in border regions and cities not too far from the Russian border. These regions and areas attract a significant number of short-stay Russian visitors who are often motivated by cross-border shopping and other activities.
Feasibility of planned mini-laparotomy and adhesiolysis at the time of robotic-assisted radical prostatectomy in patients with prior major abdominal surgery
Authors: Rajih Emad , Alhathal Naif , Alenizi Abdullah M. , El-Hakim Assaad
Published: March 2016

Introduction: Our aim was to report our experience on the feasibility of completing radical prostatectomy robotically after planned open adhesiolysis for prior major abdominal surgery with previous midline laparotomy scar.Methods: We searched our prospectively collected database of robotic assisted-radical prostatectomy (RARP) performed between October 2006 and October 2012 by a single fellowship-trained surgeon to identify all patients who underwent planned initial minilaparotomy for release of abdominal adhesions at time of RARP. Among 250 RARP patients, five patients fulfilled these criteria.Results: All patients had prostatectomy completed robotically. The mean values of patients’ demographics were as follows: Age 61.8 years (range 54‒69), body mass index 30.7 (range 24.3‒5.3), and prostate volume 41.5 ml (range 30.8‒54). Mean operative time was 245 min (range 190‒280) and estimated blood loss 410 ml (range 300‒650). Median hospital stay was one day (range 1‒7). Postoperatively, there was one prolonged ileus, which resolved spontaneously, and one myocardial infarction.Conclusions: Robotic completion of radical prostatectomy after open adhesiolysis is feasible. This approach maintains most minimally invasive advantages of RARP, despite a slightly longer hospital stay. In the best interest of patients, robotic surgeons are encouraged to finish the case robotically rather than attempting an open approach.
Effects of Different Pretreatments and Seed Coat on Dormancy and Germination of Seeds of Senna obtusifolia (L.) H.S. Irwin & Barneby (Fabaceae)
Authors: I. Mensah Stephen , Ekeke Chimezie
Published: March 2016

The seed dormancy of Senna obtusifolia was investigated through various methods, namely pretreatments in concentrated sulfuric acid, 2% potassium nitrate (KNO3), 99% ethanol, 99% methanol, and in hydrogen perioxide; examination of the seed coverings; and the determination of water uptake by the seeds in order to ascertain the most effective technique for breaking dormancy and also determine the dormancy type. The results showed that sulfuric acid treatment recorded the highest germination (100%); followed by 2% hydrogen peroxide treatment (24%) in 15minutes immersion. The methanol and ethanol pretreatments gave 18.33% and 16.5% germinations respectively. Pretreatment in 2% potassium nitrate gave the lowest germination (8.50%), while the intact seeds of S. obtusifiolia (control) gave 0% germination. The anatomy of the seed coat indicated the presence of hard, thickened and specialized cells of cuticle, macrosclereids, osteoscereids, and disintegrated parenchyma layers. The water uptake of intact seeds was low (13.5%) after 24 hr imbibitions. These findings revealed that the seed coat acts as barrier to germination by preventing water absorption, possibly gaseous diffusion in and out of the seed and conferring mechanical resistance to the protrusion of embryo. Pretreatments, such as immersion in H2SO4 will soften the seed coat and permit germination. Seed dormancy in S. obtusifolia can be considered of physical nature and classified as physical dormancy. The results obtained in this study may serve as useful information in the production and improvement of S. obtusifolia seedlings, as knowledge on seed dormancy and germination is a critical factor and requirements to the understanding of the propagation of this plant either in situ or ex-situ, in view of the economic potentials/attributes of this species.
Exploration de la socialisation à l’écrit d’élèves créolophones scolarisés en français langue seconde
Authors: Fleuret Carole
Published: March 2016

Cet article explore la socialisation à l’écrit de 11 élèves créolophones scolarisés en français langue seconde. Les résultats montrent que les élèves ont des connaissances du code alphabétique, mais qu’elles demeurent fragiles pour certains d’entre eux. Quant à la clarté cognitive du français écrit, une fluctuation plus grande apparaît dans les résultats. Les élèves ont une conscience de l’écrit, mais elle demande aussi à être renforcée. Pour soutenir la socialisation à l’écrit des élèves, nous pensons que la mise en place de programmes de littératie qui tiennent compte de l’habitus culturel de l’élève et de son environnement familial favoriserait le développement de leurs connaissances linguistiques en français langue seconde.
Les défis de l’intégration sociale et scolaire de jeunes d’origine haïtienne immigrés au Québec après le séisme survenu en Haïti en janvier 2010
Authors: Lafortune Gina
Published: March 2016

Cet article présente les résultats d’une recherche qui a documenté le cheminement socioscolaire d’une quarantaine de jeunes d’origine haïtienne immigrés au Québec après le séisme survenu en Haïti en janvier 2010. Des entretiens individuels ont été réalisés avec les jeunes, quelques parents, des enseignants et des intervenants psychosociaux ou communautaires. Ils ont permis de retracer le vécu socioscolaire des jeunes avant et après l’immigration, les besoins qu’ils ont manifestés à l’arrivée au Québec et les formes de soutien reçues de leur environnement. Les résultats montrent la grande résilience des jeunes qui essaient de surmonter les deuils, les traumas et les séparations générés par le séisme en s’investissant dans leur cheminement scolaire. Plusieurs ont pu s’intégrer remarquablement à l’école québécoise. D’autres présentent un cumul de vulnérabilités. Cet article discute de ces résultats.
Rap, langues, « québéquicité » et rapports sociaux de sexe : pratiques et expériences de rappeuses montréalaises d’origine haïtienne
Authors: Lesacher Claire
Published: March 2016

Depuis les récits retraçant ses premières heures, la scène rap montréalaise apparaît particulièrement investie par des acteurs d’origine haïtienne : un fait notamment palpable à travers les textes de rap, qui présentent fréquemment des occurrences en créole haïtien. Prenant acte de cette caractéristique du rap montréalais, nous proposons une réflexion sur les enjeux de la visibilité des migrants et descendants de migrants haïtiens au sein de l’espace public québécois, à travers une focalisation sur les pratiques et expériences de rappeuses montréalaises d’origine haïtienne. Dans cette contribution, qui vise à entrevoir les processus de majoration et de minoration à l’oeuvre dans le contexte montréalais et québécois, nous envisagerons notamment la manière dont les vecteurs de différenciation impliquant ce qui relève du linguistique, de la « québéquicité » ou des rapports sociaux de sexe s’actualisent et se reproduisent dans le cadre de la médiatisation des productions artistiques.
Small Municipalities and Planning: Dilemmas and Perspectives
Authors: Marquez Gabriel , Filippim Eliane Salete , Lazzarotti Fábio , Fischer Augusto
Published: March 2016

The paper aims to understand the experience in preparing a training strategy linked to knowledge management, learning and organizational change done at a private institution of higher education. More specifically, it seeks to detail the stages of development, analyzing the difficulties faced and provide indicators of change throughout the process. A feature of the strategic process in the researched organization led the search for a theoretical discussion could involve strategy, knowledge and change. This association was fully viable when considering events that are mobilized by people interacting in a defined context. It uses a methodology of action research in which the investigative process includes a cycle of planning, action, observation and reflection. As a result, we defined four general indicators of the actions and influencers nine indicators of knowledge management should be promoted in the strategic process.
Prevalence of hepatitis B and C viruses in HIV‐positive patients in China: a cross‐sectional study
Authors: Xie Jing , Han Yang , Qiu Zhifeng , Li Yijia , Li Yanling , Song Xiaojing , Wang Huanling , Thio Chloe L , Li Taisheng
Published: March 2016

Introduction

Liver disease related to hepatitis B (HBV) and hepatitis C (HCV) may temper the success of antiretroviral therapy (ART) in China. Limited data exist on their prevalence in HIV‐positive Chinese. A multi‐centre, cross‐sectional study was carried out to determine the prevalence and disease characteristics of HBV and HCV co‐infection in HIV‐positive patients across 12 provinces.

Methods

HIV‐positive ART‐naïve patients were recruited from two parent cohorts established during November 2008–January 2010 and August 2012–September 2014. Hepatitis B surface antigen (HBsAg), hepatitis B e antigen and HCV antibody (anti‐HCV) status were retrieved from parent databases at the visit prior to ART initiation. HBV DNA was then determined in HBsAg+ patients. HCV RNA was quantified in anti‐HCV+ patients. Aspartate aminotransferase‐to‐platelet ratio index (APRI) and the fibrosis‐4 (FIB4) were calculated. Chi‐square test, Kruskal–Wallis test and logistic regression were used for statistical analysis, as appropriate.

Results

Of 1944 HIV‐positive patients, 186 (9.5%) were HIV–HBV co‐infected and 161 (8.3%) were HIV–HCV co‐infected. The highest HIV–HBV prevalence (14.5%) was in Eastern China while the highest HIV–HCV prevalence was in the Central region (28.2%). HIV–HBV patients had lower median CD4 + T cell count (205 cells/μL) than either HIV monoinfected (242 cells/μL, P=0.01) or HIV–HCV patients (274 cells/μL, P=0.001). Moderate‐to‐significant liver disease was present in >65% of the HIV–HCV, ~35% of the HIV–HBV and ~20% of the HIV monoinfected patients. Independent associations with moderate‐to‐significant liver disease based on APRI included HBV (Odds ratio, OR 2.37, P < 0.001), HCV (OR 9.64, P<0.001), CD4 count≤200 cells/μL (OR 2.55, P<0.001) and age ≥30 years (OR 1.80, P=0.001).

Conclusions

HBV and HCV prevalence is high in HIV‐positive Chinese and differs by geographic region. HBV and HCV co‐infection and HIV monoinfection are risks for moderate‐to‐significant liver disease. Only HIV–HBV is associated with greater HIV‐related immunosuppression. Incorporating screening and management of hepatitis virus infections into Chinese HIV programmes is needed.
GSK3β regulates AKT-induced central nervous system axon regeneration via an eIF2Bε-dependent, mTORC1-independent pathway
Authors: Guo Xinzheng , Snider William D , Chen Bo
Published: March 2016

Axons fail to regenerate after central nervous system (CNS) injury. Modulation of the PTEN/mTORC1 pathway in retinal ganglion cells (RGCs) promotes axon regeneration after optic nerve injury. Here, we report that AKT activation, downstream of Pten deletion, promotes axon regeneration and RGC survival. We further demonstrate that GSK3β plays an indispensable role in mediating AKT-induced axon regeneration. Deletion or inactivation of GSK3β promotes axon regeneration independently of the mTORC1 pathway, whereas constitutive activation of GSK3β reduces AKT-induced axon regeneration. Importantly, we have identified eIF2Bε as a novel downstream effector of GSK3β in regulating axon regeneration. Inactivation of eIF2Bε reduces both GSK3β and AKT-mediated effects on axon regeneration. Constitutive activation of eIF2Bε is sufficient to promote axon regeneration. Our results reveal a key role of the AKT-GSK3β-eIF2Bε signaling module in regulating axon regeneration in the adult mammalian CNS.
Appetite controlled by a cholecystokinin nucleus of the solitary tract to hypothalamus neurocircuit
Authors: D'Agostino Giuseppe , Lyons David J , Cristiano Claudia , Burke Luke K , Madara Joseph C , Campbell John N , Garcia Ana Paula , Land Benjamin B , Lowell Bradford B , Dileone Ralph J , Heisler Lora K
Published: March 2016

The nucleus of the solitary tract (NTS) is a key gateway for meal-related signals entering the brain from the periphery. However, the chemical mediators crucial to this process have not been fully elucidated. We reveal that a subset of NTS neurons containing cholecystokinin (CCKNTS) is responsive to nutritional state and that their activation reduces appetite and body weight in mice. Cell-specific anterograde tracing revealed that CCKNTS neurons provide a distinctive innervation of the paraventricular nucleus of the hypothalamus (PVH), with fibers and varicosities in close apposition to a subset of melanocortin-4 receptor (MC4RPVH) cells, which are also responsive to CCK. Optogenetic activation of CCKNTS axon terminals within the PVH reveal the satiating function of CCKNTS neurons to be mediated by a CCKNTS→PVH pathway that also encodes positive valence. These data identify the functional significance of CCKNTS neurons and reveal a sufficient and discrete NTS to hypothalamus circuit controlling appetite.
A simple generative model of the mouse mesoscale connectome
Authors: Henriksen Sid , Pang Rich , Wronkiewicz Mark
Published: March 2016

Recent technological advances now allow for the collection of vast data sets detailing the intricate neural connectivity patterns of various organisms. Oh et al. (2014) recently published the most complete description of the mouse mesoscale connectome acquired to date. Here we give an in-depth characterization of this connectome and propose a generative network model which utilizes two elemental organizational principles: proximal attachment ‒ outgoing connections are more likely to attach to nearby nodes than to distant ones, and source growth ‒ nodes with many outgoing connections are likely to form new outgoing connections. We show that this model captures essential principles governing network organization at the mesoscale level in the mouse brain and is consistent with biologically plausible developmental processes.
Label-free detection of low-molecular-weight samples using a terahertz chemical microscope
Authors: Kuwana Takuya , Ogawa Masahiro , Sakai Kenji , Kiwa Toshihiko , Tsukada Keiji
Published: March 2016

A terahertz chemical microscope (TCM) has been proposed and developed to visualize the distribution of biomolecular interactions on a sensing plate without any labels. In this study, the concanavalin A (Con A)–d-(+)-mannose (mannose) interaction was detected using the TCM with mannose applied as the analyte and Con A immobilized on the sensing plate. To demonstrate this interaction, the amplitude of terahertz pulses as a function of Con A–mannose interaction time, as well as the Con A–mannose coupling concentration, was evaluated. The results suggest that coupling kinetics may be evaluated using a TCM.
Proposal of tunneling- and diffusion-current hybrid MOSFET: A device simulation study
Authors: Furukawa Kiichi , Teramoto Akinobu , Kuroda Rihito , Suwa Tomoyuki , Hashimoto Keiichi , Kojiri Takashi , Sugawa Shigetoshi
Published: March 2016

Transistors with low-power operation and sufficient signal processing speed have been widely required especially for mobile applications. To meet these requirements, we propose a novel tunneling- and diffusion-current hybrid MOSFETs which utilize both a small S-factor of tunneling-current and a high current drivability of diffusion-current. On the basis of the device concept and the working principle that we propose, device structures and parameters of the hybrid MOSFET were examined in detail with device simulation. We investigated the optimum structure of the tunneling and diffusion parts, and the effects of various structural parameters. In particular, we found that the threshold voltage adjustment of each current and the suppression of leakage current were the most important to maximize the characteristics of the hybrid MOSFET. From the result of structural parameter optimization, a minimum S-factor of 20 mV/decade and a high current drivability of 500 µA/µm were obtained simultaneously. In addition, a process flow idea to fabricate three-dimensional structure hybrid MOSFETs with tunneling-current side channels and diffusion-current top channel is presented.
Field emitters with nanoscale tips based on Mo oxide fabricated by electrochemical methods
Authors: Tsukamoto Takeo , Sato Takahiro , Kitamura Shin , Kitao Akiko , Kubota Oichi , Ozaki Eiji , Motoi Taiko
Published: March 2016

Field emitters with nanoscale tips and a fabrication technique using a nanoscale gap are described. Each fabrication technique makes it possible to form emitters on a meter-scale glass substrate. The emitter has a configuration with one side gate to reduce the electron scattering losses at the counter electrode to improve the emission efficiency. All thin film layers constituting the emitter are fabricated by plasma-enhanced chemical vapor deposition and sputtering deposition. Nanoscale tips are formed between a shallow gap less than 7 nm deep by the joule heating of a Mo complex oxide, which is produced by the electro chemical etching of a deposited Mo layer. To our knowledge, this is the first work that shows a uniform efficiency of 5% or more achieved at an anode voltage of 10 kV and an operation voltage of 23 V.
Analyzing charge distribution in the termination area of 4H-SiC diodes by measuring depletion-layer capacitance
Authors: Matsushima Hiroyuki , Okino Hiroyuki , Mochizuki Kazuhiro , Yamada Renichi
Published: March 2016

The distribution of positive-charge density at the SiO2/SiC interface of the termination area (Q
TM) was analyzed by measuring the depletion-layer capacitance of 4H-SiC PN diodes with different termination structures. A change in Q
TM induced by reverse-bias stressing (ΔQ
TM) caused a change in the breakdown voltage of the diodes. By comparing the measured depletion-layer capacitance to the simulated value, the initial Q
TM (

) and the distribution of ΔQ
TM were clarified. It is concluded from these results that the distribution of ΔQ
TM was not uniform but that positive charges mostly accumulated in the termination area under a high applied electric field.
Prevalence of asymptomatic urinary tract infections in morbidly obese dogs
Authors: Wynn Susan G. , Witzel Angela L. , Bartges Joseph W. , Moyers Tamberlyn S. , Kirk Claudia A.
Published: March 2016

Background.Obesity has reached epidemic proportions in dogs and, as in humans, cost of care has increased due to associated comorbidities. In humans, asymptomatic urinary tract infections (UTI) may be more prevalent in the obese. Asymptomatic bacteriuria (AB) is the term used when UTI are asymptomatic. We hypothesized that morbidly obese dogs are similarly more likely to have asymptomatic bacteriuria than lean, overweight, and moderately obese dogs.

Methods.A retrospective study was undertaken to explore a possible association between obesity and asymptomatic bacteriuria. Records from lean, overweight, and obese dogs receiving both a dual energy absorptiometry (DXA) scan and urine culture were included.

Results.Six positive urine cultures were identified among 46 dogs fulfilling search criteria. All six positive cultures were found in dogs with body fat percentage of >45%. In dogs with body fat percentage of <45%, there were no positive urine cultures.

Discussion.There was an increased prevalence of asymptomatic bacteriuria in the morbidly obese dogs in this study compared to those that were lean, overweight, or moderately obese. Whether antibiotic therapy is necessary in such cases is still being debated, but because asymptomatic bacteriuria may be associated with ascending infections, uroliths, or other complications, the data reported herein support the screening of obese patients for bacteriuria.
Seismic shear waves as Foucault pendulum
Authors: Snieder Roel , Sens‐Schönfelder Christoph , Ruigrok Elmer , Shiomi Katsuhiko
Published: March 2016

Earth's rotation causes splitting of normal modes. Wave fronts and rays are, however, not affected by Earth's rotation, as we show theoretically and with observations made with USArray. We derive that the Coriolis force causes a small transverse component for P waves and a small longitudinal component for S waves. More importantly, Earth's rotation leads to a slow rotation of the transverse polarization of S waves; during the propagation of S waves the particle motion behaves just like a Foucault pendulum. The polarization plane of shear waves counteracts Earth's rotation and rotates clockwise in the Northern Hemisphere. The rotation rate is independent of the wave frequency and is purely geometric, like the Berry phase. Using the polarization of ScS and ScS2 waves, we show that the Foucault‐like rotation of the S wave polarization can be observed. This can affect the determination of source mechanisms and the interpretation of observed SKS splitting.
Evaluation of landfalling atmospheric rivers along the U.S. West Coast in reanalysis data sets
Authors: Jackson Darren L. , Hughes Mimi , Wick Gary A.
Published: March 2016

An intercomparison of landfalling atmospheric rivers (ARs) between four reanalysis data sets using one satellite‐derived AR detection method as a metric to characterize landfalling atmospheric rivers (ARs) along the U.S. West Coast is performed over 15 cool seasons (October–March) during the period from water years 1998 to 2012. The four reanalysis data sets analyzed in this study are the Climate System Forecast Reanalysis (CFSR), Modern‐Era Retrospective Analysis for Research and Applications (MERRA), ERA‐Interim (ERA‐I), and the Twentieth Century Reanalysis version 2 (20CR) data set. The Atmospheric River Detection Tool is used to identify AR features in the total vertically integrated water vapor (IWV) data of the reanalysis data, and validation of the reanalysis AR data are compared with AR data derived from satellite IWV observations. The AR landfall data from reanalysis were generally found to be in good agreement with satellite observations. Reanalysis data with less (CFSR) or no assimilation (20CR) of the satellite data used in this study had greater bias with AR characteristics such as IWV, width, and landfall location. The 20CR ensemble data were found to better characterize the AR landfall characteristics than the 20CR ensemble mean although all 20CR data underestimated AR landfalls particularly in the southern section of the U.S. West Coast. Overall AR landfall detections for the 15 year cool season period were within 5% of the satellite for the CFSR, MERRA, and ERA‐I data.
Future summer precipitation changes over CORDEX‐East Asia domain downscaled by a regional ocean‐atmosphere coupled model: A comparison to the stand‐alone RCM
Authors: Zou Liwei , Zhou Tianjun
Published: March 2016

Climate changes under the RCP8.5 scenario over the Coordinated Regional Downscaling Experiment (CORDEX)‐East Asia domain downscaled by a regional ocean‐atmosphere coupled model Flexible Regional Ocean‐Atmosphere Land System (FROALS) are compared to those downscaled by the corresponding atmosphere‐only regional climate model driven by a global climate system model. Changes in the mean and interannual variability of summer rainfall were discussed for the period of 2051–2070 with respect to the present‐day period of 1986–2005. Followed by an enhanced western North Pacific subtropical high and an intensified East Asian summer monsoon, an increase in total rainfall over north China, the Korean Peninsula, and Japan but a decrease in total rainfall over southern China are observed in the FROALS projection. Homogeneous increases of extreme rainfall amounts were found over the CORDEX‐East Asia domain. A predominant increase in the interannual variability was evident for both total rainfall and the extreme rainfall amount. The spatial patterns of the projected rainfall changes by FROALS were generally consistent with those from the driving global model at a broad scale due to similar projected circulation changes. In both models, the enhanced southerlies over east China increased the moisture divergences over southern China and enhanced the moisture advection over north China. However, the atmosphere‐only regional climate model (RCM) exhibited responses to the underlying sea surface temperature (SST) warming anomalies that were too strong, which induced an anomalous cyclone over the north South China Sea, followed by increases (decreases) of total and extreme rainfall over southern China (central China). The differences of the projected changes in both rainfall and circulation between FROALS and the atmosphere‐only RCM were partly affected by the differences in the projected SST changes. The results recommend the employment of a regional ocean‐atmosphere coupled model in the dynamical downscaling of climate change over the CORDEX‐East Asian domain.
Hollow‐Fiber Methodology for Pharmacokinetic/Pharmacodynamic Studies of Antimalarial Compounds
Authors: Caton Emily , Nenortas Elizabeth , Bakshi Rahul P. , Shapiro Theresa A.
Published: March 2016

Knowledge of pharmacokinetic/pharmacodynamic (PK/PD) relationships can enhance the speed and economy of drug development by enabling informed and rational decisions at every step, from lead selection to clinical dosing. For anti‐infective agents in particular, dynamic in vitro hollow‐fiber cartridge experiments permit exquisite control of kinetic parameters and the study of their consequent impact on pharmacodynamic efficacy. Such information is of great interest for the cost‐restricted but much‐needed development of new antimalarial drugs, especially since the major human pathogen Plasmodium falciparum can be cultivated in vitro but is not readily available in animal models. This protocol describes the materials and procedures for determining the PK/PD relationships of antimalarial compounds. © 2016 by John Wiley & Sons, Inc.
Functional Coatings Based on Preceramic Polymers
Authors: Barroso Gilvan , Kraus Tobias , Degenhardt Ulrich , Scheffler Michael , Motz Günter
Published: March 2016

Polymer‐derived ceramic (PDC) processing represents a versatile complement for the preparation of ceramic coatings. Filler‐loaded preceramic polymer layers can be deposited by methods such as dip coating even on substrates with a complex geometry, and subsequent thermal processing results in the formation of ceramic coatings. This specific polymer‐to‐ceramic processing route allows to tailor the coating's characteristics, e.g., surface‐structured coatings, thermal barrier coatings, and coatings for tribological applications. As coating systems polysilazanes and polysilsesquioxanes were combined in different approaches with PDC spheres, hexagonal, and cubic boron nitride.
Sustained Water Oxidation by Direct Electrosynthesis of Ultrathin Organic Protection Films on Silicon
Authors: Azarpira Anahita , Schedel‐Niedrig Thomas , Lewerenz H.‐J. , Lublow Michael
Published: March 2016

Artificial photosynthesis allows exceeding the efficiency and stability limits of natural photosynthesis. Based on the use of semiconducting absorbers, high efficiency in water photolysis has been achieved in various photoelectrode configurations. However, integrated systems are limited in their stability, and more stable half‐cell electrodes use protection films prepared by laborious methods. Herein, the facile low‐temperature preparation of ultrathin organic protection coatings is demonstrated. The formation is based on the catalytic properties of water oxidation catalysts toward alcohol‐polymerization reactions, which results in the formation of hitherto unknown protection layers on silicon. The interfacial layers are generated via iodine‐mediated electro‐reductive polymerization of ethanol, concomitantly forming during electrophoretic transport of RuO2 onto silicon supports. Reaction chemistry analyses show that the RuO2‐induced catalysis introduces E2‐elimination reactions which result in a carbon sp3–sp2 transformation of the film. For the two modes of photoelectrochemical operation, the photovoltaic and the photoelectrocatalytic mode, 20 and 15 mA cm−2 photocurrent densities, respectively, are obtained with unaltered output for 8 and 24 h. The interfacial layer enables Si photovoltages of 500 mV, demonstrating extraordinary electronic interface quality. Since only hydrogen termination of the surface is a prerequisite for growth of the organic protection layer, the method is applicable to a wide range of semiconductors.
Long‐term outcome of patients with POEMS syndrome: An update of the Mayo Clinic experience
Authors: Kourelis Taxiarchis V. , Buadi Francis K. , Kumar Shaji K. , Gertz Morie A. , Lacy Martha Q. , Dingli David , Go Ronald S. , Kapoor Prashant , Lust John A. , Hayman Suzanne R. , Hwa Yi , Rajkumar S. Vincent , Zeldenrust Steven R. , Russell Stephen J. , Lin Yi , Leung Nelson , Kyle Robert A. , Gonsalves Wilson I. , Dispenzieri Angela
Published: March 2016

Over the past decade, a number of changes have occurred in the diagnostic evaluation, management, and long‐term follow‐up of patients with POEMS syndrome at our institution. This study included 291 patients with POEMS syndrome diagnosed at the Mayo Clinic between 1974 and 2014. Patients diagnosed after 2003 had more features of the syndrome identified at diagnosis and were more likely to receive an autologous transplant (49% versus 8%, P < 0.0001) and to have achieved a hematologic complete response (CR) to treatment (41% vs 25%, P < 0.0001). With 2273 person‐years of follow‐up, 10‐year overall survival (OS) was 62% (95% C.I., 56%, 67%). On multivariate analysis, the three factors associated with superior OS were younger age (RR 0.98 [0.96–1.00]), albumin greater‐than 3.2 g/dL (RR 0.5 [0.32–0.89]) and attainment of complete hematologic response (RR 0.4 [0.2, 0.9]). This study confirms the very good long‐term outcomes of patients with POEMS syndrome and identifies two new prognostic risk factors: albumin at diagnosis and attainment of complete hematologic response. Am. J. Hematol. 91:585–589, 2016. © 2016 Wiley Periodicals, Inc.