bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism for potential strengthening of Atlantic overturning prior to collapse
Authors: Ehlert D. , Levermann A.
Published: November 2014

Abstract. The Atlantic meridional overturning circulation (AMOC) carries large amounts of heat into the North Atlantic influencing climate regionally as well as globally. Palaeo-records and simulations with comprehensive climate models suggest that the positive salt-advection feedback may yield a threshold behaviour of the system. That is to say that beyond a certain amount of freshwater flux into the North Atlantic, no meridional overturning circulation can be sustained. Concepts of monitoring the AMOC and identifying its vicinity to the threshold rely on the fact that the volume flux defining the AMOC will be reduced when approaching the threshold. Here we advance conceptual models that have been used in a paradigmatic way to understand the AMOC, by introducing a density-dependent parameterization for the Southern Ocean eddies. This additional degree of freedom uncovers a mechanism by which the AMOC can increase with additional freshwater flux into the North Atlantic, before it reaches the threshold and collapses: an AMOC that is mainly wind-driven will have a constant upwelling as long as the Southern Ocean winds do not change significantly. The downward transport of tracers occurs either in the northern sinking regions or through Southern Ocean eddies. If freshwater is transported, either atmospherically or via horizontal gyres, from the low to high latitudes, this would reduce the eddy transport and by continuity increase the northern sinking which defines the AMOC until a threshold is reached at which the AMOC cannot be sustained. If dominant in the real ocean this mechanism would have significant consequences for monitoring the AMOC.
On linking an Earth system model to the equilibrium carbon representation of an economically optimizing land use model
Authors: Bond-Lamberty B. , Calvin K. , Jones A. D. , Mao J. , Patel P. , Shi X. Y. , Thomson A. , Thornton P. , Zhou Y.
Published: November 2014

Abstract. Human activities are significantly altering biogeochemical cycles at the global scale, and the scope of these activities will change with both future climate and socioeconomic decisions. This poses a significant challenge for Earth system models (ESMs), which can incorporate land use change as prescribed inputs but do not actively simulate the policy or economic forces that drive land use change. One option to address this problem is to couple an ESM with an economically oriented integrated assessment model, but this is challenging because of the radically different goals and underpinnings of each type of model. This study describes the development and testing of a coupling between the terrestrial carbon cycle of an ESM (CESM) and an integrated assessment (GCAM) model, focusing on how CESM climate effects on the carbon cycle could be shared with GCAM. We examine the best proxy variables to share between the models, and we quantify how carbon flux changes driven by climate, CO2 fertilization, and land use changes (e.g., deforestation) can be distinguished from each other by GCAM. The net primary production and heterotrophic respiration outputs of the Community Land Model (CLM), the land component of CESM, were found to be the most robust proxy variables by which to recalculate GCAM's assumptions of equilibrium ecosystem steady-state carbon. Carbon cycle effects of land use change are spatially limited relative to climate effects, and thus we were able to distinguish these effects successfully in the model coupling, passing only the latter to GCAM. This paper does not present results of a fully coupled simulation but shows, using a series of offline CLM simulations and an additional idealized Monte Carlo simulation, that our CESM–GCAM proxy variables reflect the phenomena that we intend and do not contain erroneous signals due to land use change. By allowing climate effects from a full ESM to dynamically modulate the economic and policy decisions of an integrated assessment model, this work will help link these models in a robust and flexible framework capable of examining two-way interactions between human and Earth system processes.
Observed groundwater temperature response to recent climate change
Authors: Menberg K. , Blum P. , Kurylyk B. L. , Bayer P.
Published: November 2014

Abstract. Climate change is known to have a considerable influence on many components of the hydrological cycle. Yet, the implications for groundwater temperature, as an important driver for groundwater quality, thermal use and storage, are not yet comprehensively understood. Furthermore, few studies have examined the implications of climate-change-induced groundwater temperature rise for groundwater-dependent ecosystems. Here, we examine the coupling of atmospheric and groundwater warming by employing stochastic and deterministic models. Firstly, several decades of temperature time series are statistically analyzed with regard to climate regime shifts (CRSs) in the long-term mean. The observed increases in shallow groundwater temperatures can be associated with preceding positive shifts in regional surface air temperatures, which are in turn linked to global air temperature changes. The temperature data are also analyzed with an analytical solution to the conduction–advection heat transfer equation to investigate how subsurface heat transfer processes control the propagation of the surface temperature signals into the subsurface. In three of the four monitoring wells, the predicted groundwater temperature increases driven by the regime shifts at the surface boundary condition generally concur with the observed groundwater temperature trends. Due to complex interactions at the ground surface and the heat capacity of the unsaturated zone, the thermal signals from distinct changes in air temperature are damped and delayed in the subsurface, causing a more gradual increase in groundwater temperatures. These signals can have a significant impact on large-scale groundwater temperatures in shallow and economically important aquifers. These findings demonstrate that shallow groundwater temperatures have responded rapidly to recent climate change and thus provide insight into the vulnerability of aquifers and groundwater-dependent ecosystems to future climate change.
NANOMATRIX STRUCTURE FORMED BY GRAFT COPOLYMERIZATION OF STYRENE ONTO FRESH NATURAL RUBBER
Authors: Fukuhara L. , Kado N. , Thuong N. T. , Loykulant S. , Suchiva K. , Kosugi K. , Yamamoto Y. , Ishii H. , Kawahara S.
Published: November 2014

Fresh NR was adopted to prepare rubber with a nanomatrix structure. The nanomatrix structure was formed by graft-copolymerization of styrene onto deproteinized fresh NR (fresh DPNR) in the latex stage using tert-butyl hydroperoxide/tetraethylenepentamine as an initiator. Graft-copolymer consisting of fresh DPNR and polystyrene (fresh DPNR-graft-PS) was characterized by 1H-NMR spectroscopy and transmission electron microscopy. Under a suitable condition of the graft-copolymerization, conversion and grafting efficiency of styrene was 98 and 80 mol%, respectively. Morphology of fresh DPNR-graft-PS was observed by transmission electron microscopy. The rubber particles of about 1 μm in diameter were found to be dispersed in polystyrene matrix of 10–30 nm in thickness. Tensile properties of fresh DPNR were dramatically improved by forming the nanomatrix structure, compared with DPNR.
Theoretical Calculations of Mechanical, Electronic, and Chemical Bonding in CaN2, SrN2, and BaN2
Authors: Zhang Li-Qin , Cheng Yan , Niu Zhen-Wei , Piao Chang-Ge , Ji Guang-Fu
Published: November 2014

We present a first-principles density functional theory-based study about the impact of pressure on the structural and elastic properties of bulk CaN2, SrN2, and BaN2. Non-spin and spin polarized calculations indicate that the non-spin polarized ground state was more favourable with magnetic moments of 1.049 μB, 1.059 μB, and 1.014 μB for CaN2, SrN2, and BaN2, respectively, and these were in good agreement with previous experimental and theoretical data. The high bulk modulus of CaN2, SrN2, and BaN2 confirm that those compounds have low compressibility and high hardness. The obtained bulk modulus, N-N bond length, and optimized structure parameters are similar to those from previous studies.With an increase in applied pressure the independent elastic constants of CaN2, SrN2, and BaN2 indicated the presence of mechanical instability at 20, 15, and 10 GPa, which is possibly related to phase transitions in addition to a decrease in N-N bond length.
Development of Predictive Models for Continuous Flow Left Ventricular Assist Device Patients using Bayesian Networks
Authors: Loghmanpour Natasha A. , Kanwar Manreet K. , Benza Raymond L. , Murali Srinivas , Antaki James F.
Published: November 2014

Background: Existing prognostic tools for patient selection for ventricular assist devices (VADs) such as the Destination Therapy Risk Score (DTRS) and newly published HeartMate II Risk Score (HMRS) have limited predictive ability, especially with the current generation of continuous flow VADs (cfVADs). This study aims to use a modern machine learning approach, employing Bayesian Networks (BNs), which overcomes some of the limitations of traditional statistical methods.
Methods: Retrospective data from 144 patients at Allegheny General Hospital and Integris Health System from 2007 to 2011 were analyzed. 43 data elements were grouped into four sets: demographics, laboratory tests, hemodynamics, and medications. Patients were stratified by survival at 90 days post LVAD.
Results: The independent variables were ranked based on their predictive power and reduced to an optimal set of 10: hematocrit, aspartate aminotransferase, age, heart rate, transpulmonary gradient, mean pulmonary artery pressure, use of diuretics, platelet count, blood urea nitrogen and hemoglobin. Two BNs, Naïve Bayes (NB) and Tree-Augmented Naïve Bayes (TAN) outperformed the DTRS in identifying low risk patients (specificity: 91% and 93% vs. 78%) and outperformed HMRS predictions of high risk patients (sensitivity: 80% and 60% vs. 25%). Both models were more accurate than DTRS and HMRS (90% vs. 73% and 84%), Kappa (NB: 0.56 TAN: 0.48, DTRS: 0.14, HMRS: 0.22), and AUC (NB: 80%, TAN: 84%, DTRS: 59%, HMRS: 59%).
Conclusion: The Bayesian Network models developed in this study consistently outperformed the DTRS and HMRS on all metrics. An added advantage is their intuitive graphical structure that closely mimics natural reasoning patterns. This warrants further investigation with an expanded patient cohort, and inclusion of adverse event outcomes.
Graphical Investigation of Threshold Choice Effect on Odds Ratio Related to Prognostic Factors in Stroke Recovery
Authors: Iosa Marco , Morone Giovanni , Fusco Augusto , Paolucci Stefano
Published: November 2014

The aim of this study was to assess the effects of the arbitrary choices of threshold-values for dichotomizing not binary factors on the computation of odds ratio (OR) for the identification of prognostic factors, in particular of motor recovery after stroke.
Data of a sample of 1000 patients with subacute stroke have been analysed. We considered as dependent variable the effectiveness of neurorehabilitation (i.e. the achieved level of independency in activities of daily living, measured using the Barthel Index, expressed in percentage of the maximum achievable improvement), and as independent variables age, time between stroke acute event and beginning of neurorehabilitation, gender, type of stroke (ischemic vs. haemorragic) and side of hemiparesis. We performed univariate analyses for computing OR with respect to different choices of threshold for dichotomizing age and time from stroke. In this analysis median value of effectiveness was used for dichotomizing subjects in good and poor responders. Then these analyses were repeated also varying the threshold-value of effectiveness. Finally multivariate analyses based on forward binary logistic regression were performed varying at the same time the thresholds of age and time from stroke. With respect to threshold choice, OR-values of age resulted stable, but those of time from stroke resulted more variable. Variability increased when also the threshold chosen for dichotomizing the independent variable was changed. Multivariate analyses showed that these choices could even make not statistically significant the effect of a binary prognostic factor such as gender. In conclusion, OR-values resulted affected by threshold choices. It can increase the difficulties in marking predictions of outcomes after stroke. In this study we reported a possible graphical evaluation of the variability of OR-values with respect of threshold choice, that can be helpful whenever threshold is arbitrary chosen.
Estimating the Population Standard Deviation with Confidence Interval: A Simulation Study under Skewed and Symmetric Conditions
Authors: Banik Shipra , Albatineh Ahmed N. , Abu-Shawiesh Moustafa Omar Ahmed , Golam Kibria B. M.
Published: November 2014

This paper investigates the performance of ten methods for constructing a confidence interval estimator for the population standard deviation by a simulation study. Since a theoretical comparison among the interval estimators is not possible, a simulation study has been conducted to compare the performance of the selected interval estimators. Data were randomly generated from several distributions with a range of sample sizes. Various evaluation criterions are considered for performance comparison. Two health related data have been analyzed to illustrate the application of the proposed confidence intervals. Based on simulation results, some intervals with the best performance have been recommended for practitioners.
Determinants of Wasting Among Under-Five Children in Ethiopia: (A Multilevel Logistic Regression Model Approach)
Authors: Dabale Gutu Adugna , Sharma M. K
Published: November 2014

Child malnutrition in Ethiopia is one of the most serious public health problems and the highest in the world. Wasting refers to low weight-for-height and measures the body’s mass in relation to body length. The objective of this study was to identify determinants of wasting among under-five children in Ethiopia. The study used data collected in the Ethiopian Demographic and Health Survey in 2010/2011. A total of 9611 under-five age children were included in the present study. To analyze the data descriptive statistics and multilevel binary logistic regression techniques were employed. The descriptive statistics results indicate that about 11.7 % of under-five children in Ethiopia were wasted. The results of study indicated that the risk of wasting was highest among male children, small size at birth, children whose parents resided in rural areas, children’s of illiterate mothers, children whose mother’s body mass index was low, children from poor families and children who had diarrhea and fever two weeks before the date of the survey. The multilevel model also showed the existence of significant variations in the prevalence of wasting among the regions in Ethiopia.
Examining the Probabilities of Type I Error for Unadjusted All Pairwise Comparisons and Bonferroni Adjustment Approaches in Hypothesis Testing for Proportions
Authors: Cangur Sengul , Ankarali Handan
Published: November 2014

The aim of this study is to examine the association among the probabilities of Type I error obtained by Unadjusted All Pairwise Comparisons (UAPC) and Bonferroni-adjustment approaches, the sample size and the frequency of occurrence of an event (prevalence, proportion) in hypothesis testing of difference among the proportions in studies. In the simulation experiment planned for this purpose, 4 groups were formed and the proportions in each group were chosen between 0.10 and 0.90 so that they will be equal at each experiment. Furthermore, the sample sizes were chosen from 20 to 1000. In accordance with these scenarios, the probabilities of Type I error were calculated by both of approaches. In each approach, a significant S-curve relationship was found between the probability of Type I error and sample size. However, a significant quadratic relationship was found between the probabilities of Type I error and the proportions in each group. Nonlinear functional relations were put forward in order to estimate the observed Type I error rates obtained by the two different approaches where sample size and the proportion in each group are known. Furthermore, it was founded that Bonferroni-adjustment approach cannot always protect Type I error level. It was observed that the probability of Type I error estimated by the functional relation on Type I error rate for UAPC approach is lower than the values calculated using the formula in the literature.
Modeling the spreading of glacial meltwater from the Amundsen and Bellingshausen Seas
Authors: Nakayama Y. , Timmermann R. , Rodehacke C. B. , Schröder M. , Hellmer H. H.
Published: November 2014

It has been suggested that an increased melting of continental ice in the Amundsen Sea (AS) and Bellingshausen Sea (BS) is a likely source of the observed freshening of Ross Sea (RS) water. To test this hypothesis, we simulate the spreading of glacial meltwater using the Finite Element Sea Ice/Ice Shelf/Ocean Model. Based on the spatial distribution of simulated passive tracers, most of the basal meltwater from AS ice shelves flows toward the RS with more than half of the melt originating from the Getz Ice Shelf. Further, the model results show that a slight increase of the basal mass loss can substantially intensify the transport of meltwater into the RS due to a strengthening of the melt‐driven shelf circulation and the westward flowing coastal current. This supports the idea that the basal melting of AS and BS ice shelves is one of the main sources for the RS freshening.
Counteracting the climate effects of volcanic eruptions using short‐lived greenhouse gases
Authors: Fuglestvedt Jan S. , Samset Bjørn H. , Shine Keith P.
Published: November 2014

A large volcanic eruption might constitute a climate emergency, significantly altering global temperature and precipitation for several years. Major future eruptions will occur, but their size or timing cannot be predicted. We show, for the first time, that it may be possible to counteract these climate effects through deliberate emissions of short‐lived greenhouse gases, dampening the abrupt impact of an eruption. We estimate an emission pathway countering a hypothetical eruption 3 times the size of Mount Pinatubo in 1991. We use a global climate model to evaluate global and regional responses to the eruption, with and without counteremissions. We then raise practical, financial, and ethical questions related to such a strategy. Unlike the more commonly discussed geoengineering to mitigate warming from long‐lived greenhouse gases, designed emissions to counter temporary cooling would not have the disadvantage of needing to be sustained over long periods. Nevertheless, implementation would still face significant challenges.
A low‐frequency near‐field interferometric‐TOA 3‐D Lightning Mapping Array
Authors: Lyu Fanchao , Cummer Steven A. , Solanki Rahulkumar , Weinert Joel , McTague Lindsay , Katko Alex , Barrett John , Zigoneanu Lucian , Xie Yangbo , Wang Wenqi
Published: November 2014

We report on the development of an easily deployable LF near‐field interferometric‐time of arrival (TOA) 3‐D Lightning Mapping Array applied to imaging of entire lightning flashes. An interferometric cross‐correlation technique is applied in our system to compute windowed two‐sensor time differences with submicrosecond time resolution before TOA is used for source location. Compared to previously reported LF lightning location systems, our system captures many more LF sources. This is due mainly to the improved mapping of continuous lightning processes by using this type of hybrid interferometry/TOA processing method. We show with five station measurements that the array detects and maps different lightning processes, such as stepped and dart leaders, during both in‐cloud and cloud‐to‐ground flashes. Lightning images mapped by our LF system are remarkably similar to those created by VHF mapping systems, which may suggest some special links between LF and VHF emission during lightning processes.
Black carbon radiative forcing over the Tibetan Plateau
Authors: He Cenlin , Li Qinbin , Liou Kuo‐Nan , Takano Yoshi , Gu Yu , Qi Ling , Mao Yuhao , Leung L. Ruby
Published: November 2014

We estimate the snow albedo forcing and direct radiative forcing (DRF) of black carbon (BC) in the Tibetan Plateau using a global chemical transport model in conjunction with a stochastic snow model and a radiative transfer model. The annual mean BC snow albedo forcing is 2.9 W m−2 averaged over snow‐covered plateau regions, which is a factor of 3 larger than the value over global land snowpack. BC‐snow internal mixing increases the albedo forcing by 40–60% compared with external mixing, and coated BC increases the forcing by 30–50% compared with uncoated BC aggregates, whereas Koch snowflakes reduce the forcing by 20–40% relative to spherical snow grains. The annual BC DRF at the top of the atmosphere is 2.3 W m−2 with uncertainties of −70–85% in the plateau after scaling the modeled BC absorption optical depth to Aerosol Robotic Network observations. The BC forcings are attributed to emissions from different regions.
The source altitude, electric current, and intrinsic brightness of terrestrial gamma ray flashes
Authors: Cummer Steven A. , Briggs Michael S. , Dwyer Joseph R. , Xiong Shaolin , Connaughton Valerie , Fishman Gerald J. , Lu Gaopeng , Lyu Fanchao , Solanki Rahulkumar
Published: November 2014

Many details of how thunderstorms generate terrestrial gamma ray flashes (TGFs) and other forms of high‐energy radiation remain uncertain, including the basic question of where they are produced. We exploit the association of distinct low‐frequency radio emissions with generation of terrestrial gamma ray flashes (TGFs) to directly measure for the first time the TGF source altitude. Analysis of two events reveals source altitudes of 11.8 ± 0.4 km and 11.9 ± 0.9 km. This places the source region in the interior of the thunderstorm between the two main charge layers and implies an intrinsic TGF brightness of approximately 1018 runaway electrons. The electric current in this nontraditional lightning process is found to be strong enough to drive nonlinear effects in the ionosphere, and in one case is comparable to the highest peak current lightning processes on the planet.
Adaptive nonsingular terminal sliding mode control of MEMS gyroscope based on backstepping design
Authors: Fei Juntao , Yan Weifeng , Yang Yuzheng
Published: November 2014

An adaptive nonsingular terminal sliding mode (NTSM) tracking control scheme based on backstepping design is presented for micro‐electro‐mechanical systems (MEMS) vibratory gyroscopes in this paper. The NTSM controller is designed based on backstepping strategy to eliminate the singularity, while ensuring the control system to reach the sliding surface and converge to equilibrium point in a finite period of time from any initial state. In addition, the proposed approach develops an online identifier scheme, which can real‐time estimate the angular velocity and the damping and stiffness coefficients. All adaptive laws in the control system are derived in the same Lyapunov framework, which can guarantee the globally asymptotical stability of the closed‐loop system. Numerical simulations for a MEMS gyroscope are investigated to demonstrate the validity of the proposed control approaches. Copyright © 2014 John Wiley & Sons, Ltd.
Integration of 2D and 3D Thin Film Glassy Carbon Electrode Arrays for Electrochemical Dopamine Sensing in Flexible Neuroelectronic Implants
Authors: VanDersarl Jules J. , Mercanzini André , Renaud Philippe
Published: November 2014

Here we present the development and characterization of a flexible implantable neural probe with glassy carbon electrode arrays. The use of carbon electrodes allows for these devices to be used as chemical sensors, in addition to their typical use as electrical sensors and stimulators. The devices are fabricated out of polyimide, platinum, titanium, and carbon with standard microfabrication techniques on carrier wafers. The devices are released from the substrate through either chemical or electrochemical dissolution of the underlying substrate material. The glassy carbon electrode arrays are produced through the pyrolysis of SU‐8 pillars at 900 °C as the first process step, as this temperature is incompatible with the other device materials. The process demonstrated here is generally applicable, allowing for the integration of various high temperature materials into flexible devices.
Enhanced Vertical Charge Transport in a Semiconducting P3HT Thin Film on Single Layer Graphene
Authors: Skrypnychuk Vasyl , Boulanger Nicolas , Yu Victor , Hilke Michael , Mannsfeld Stefan C. B. , Toney Michael F. , Barbero David R.
Published: November 2014

The crystallization and electrical characterization of the semiconducting polymer poly(3‐hexylthiophene) (P3HT) on a single layer graphene sheet is reported. Grazing incidence X‐ray diffraction revealed that P3HT crystallizes with a mixture of face‐on and edge‐on lamellar orientations on graphene compared to mainly edge‐on on a silicon substrate. Moreover, whereas ultrathin (10 nm) P3HT films form well oriented face‐on and edge‐on lamellae, thicker (50 nm) films form a mosaic of lamellae oriented at different angles from the graphene substrate. This mosaic of crystallites with π–π stacking oriented homogeneously at various angles inside the film favors the creation of a continuous pathway of interconnected crystallites, and results in a strong enhancement in vertical charge transport and charge carrier mobility in the thicker P3HT film. These results provide a better understanding of polythiophene crystallization on graphene, and should help the design of more efficient graphene based organic devices by control of the crystallinity of the semiconducting film.
Electron‐Driven Self‐Assembly of Salt Nanocrystals in Liquid Helium
Authors: Daxner Matthias , Denifl Stephan , Scheier Paul , Ellis Andrew M.
Published: November 2014

The self‐assembly of salt nanocrystals from chemical reactions inside liquid helium is reported for the first time. Reaction is initiated by an electron impacting a helium nanodroplet containing sodium atoms and SF6 molecules, leading to preferential production of energetically favorable structures based on the unit cell of crystalline NaF. These favorable structures are observed as magic number ions (anomalously intense peaks) in mass spectra and are seen in both cationic and anionic channels in mass spectra, for example, (NaF)nNa+ and (NaF)nF−. In the case of anions the self‐assembly is not directly initiated by electrons: the dominant process involves resonant electron‐induced production of metastable electronically excited He− anions, which then initiate anionic chemistry by electron transfer.
“They are always there for me”: The convergence of social support and information in an online breast cancer community
Authors: Rubenstein Ellen L.
Published: November 2014

This research examines interactions among members of an online breast cancer community, focusing on how information and social support were exchanged, how these exchanges influenced health decisions, and how the community was integrated into participants' everyday lives. This article is the result of a 2‐year ethnography comprising online archives analysis, participant observation, and 31 interviews. In the course of the research, the findings revealed that, not only did participants exchange valuable information and helpful social support, there was often little separation between the two, with each overlaying the other throughout most interactions. Expressions of support permeated many informational messages and at the same time served as information to participants. This article argues that social support and information were inextricably connected within participant interactions and that social support is, itself, a form of information that impacts actions and emotional experiences, contributing to participants being able to make sense of their experiences and to move forward both physically and emotionally. This research builds on work in information science that looks at the ways in which people exchange information in informal environments and extends that research by drawing on conceptualizations of social support to exhibit the connections between social support and information.
Professional information disclosure on social networks: The case of Facebook and LinkedIn in Israel
Authors: Zhitomirsky‐Geffet Maayan , Bratspiess Yair
Published: November 2014

Disclosure of personal information on social networks has been extensively researched in recent years from different perspectives, including the influence of demographic, personality, and social parameters on the extent and type of disclosure. However, although some of the most widespread uses of these networks nowadays are for professional, academic, and business purposes, a thorough investigation of professional information disclosure is still needed. This study's primary aim, therefore, is to conduct a systematic and comprehensive investigation into patterns of professional information disclosure and various factors involved on different types of social networks. To this end, a user survey was conducted. We focused specifically on Facebook and LinkedIn, the 2 diverse networks most widely used in Israel. Significant differences were found between these networks. For example, we found that on Facebook professional pride is a factor in professional information disclosure, whereas on LinkedIn, work seniority and income have a significant effect. Thus, our findings shed light on the attitudes and professional behavior of network members, leading to recommendations regarding advertising strategies and network‐appropriate self‐presentation, as well as approaches that companies might adopt according to the type of manpower required.
Determination of a temporally and spatially resolved supernova rate from OB stars within 5 kpc
Authors: Schmidt J. G. , Hohle M. M. , Neuhäuser R.
Published: November 2014

We spatially and temporally resolve the future Supernova (SN) rate in the Solar vicinity and the whole Galaxy by comparing observational parameters of massive stars with theoretical models for estimating age and mass and, hence, the remaining lifetime until the SN explosion. Our SN rate derived in time and space for the future (few Myr) should be the same as in the last few Myr by assuming a constant rate. From BVRIJHK photometry, parallax, spectral type, and luminosity class we compile a Hertzsprung‐Russell diagram (HRD) for 25027 massive stars and derive extinction, and luminosity, then mass, age, and remaining lifetime from evolutionary models. Within 600 pc our sample of SN progenitors and, hence, SN prediction, is complete, and all future SN events of our sample stars take place in 8 % of the area of the sky, whereas 90 % of the events take place in 7 % of the area of the sky. The current SN rate within 600 pc is increased by a factor of 5–6 compared with the Galactic rate. For a distance of 5 kpc our sample is incomplete, nevertheless 90 % of those SN events take place in only 12 % of the area of the projected sky. If the SN rate in the near future is the same as the recent past, there should be unknown young neutron stars concentrated in those areas. Our distribution can be used as input for constraints of gravitational waves detection and for neutron star searches. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of Er3+ concentration on the photoluminescence characteristics and excitation mechanism of Gd2O3:Er3+ phosphor synthesized via a solid‐state reaction method
Authors: Tamrakar R. K. , Bisen D. P. , Bramhe N.
Published: November 2014

An Er3+‐doped phosphor of Gd2O3 (Gd2O3:Er3+) was prepared using a conventional solid‐state reaction method. The structure and particle size were determined from X‐ray powder diffraction measurements. The average particle size of the phosphor was in between 20 and 50 nm. The particle size and structure of the phosphor were further confirmed by transmission electron microscopy (TEM) analysis. Luminescence spectra were recorded under excitation wavelengths of 275, 380, 515 and 980 nm. The visible upconversion and downconversion luminescence spectra of the Gd2O3:Er3+ phosphor were investigated as a function of Er3+ ion concentration. The upconverted emission at 980 nm excitation shows enhanced red emission with respect to green emission as the dopant concentration increased. Similar results were observed for downconversion emission under 275 and 380 nm excitation wavelengths. The mechanisms responsible for populating the 4S3/2 and 4 F9/2 levels, for green and red emissions, respectively, are different for different excitations and for different concentrations of Er3+. Copyright © 2014 John Wiley & Sons, Ltd.
Representative mammalian cell culture test materials for assessment of primary recovery technologies: A rapid method with industrial applicability
Authors: Popova Daria , Stonier Adam , Pain David , Titchener‐Hooker Nigel J. , Farid Suzanne S.
Published: November 2014

Mammalian cell culture material is often difficult to produce accurately and reproducibly for downstream studies. This article presents a methodology for the creation of a set of cell culture test materials where key variables including cell density, cell viability, product, and the host cell protein (HCP) load can be manipulated individually. The methodology was developed using a glutamine synthetase Chinese hamster ovary cell line cultured at 5‐L and 70‐L scales. Cell concentration post‐cell growth was manipulated using tangential flow filtration to generate a range of target cell densities of up to 100 × 106 cells/mL. A method to prepare an apoptotic cell stock to achieve target viabilities of 40–90% is also described. In addition, a range of IgG1 and HCP concentrations was achieved. The results illustrate that the proposed methodology is able to mimic different cell culture profiles by decoupling the control of the key variables. The cell culture test materials were shown to be representative of typical cell culture feed material in terms of particle size distribution and HCP population. This provides a rapid method to create the required feeds for assessing the feasibility of primary recovery technologies designed to cope with higher cell density cultures.
A two‐enzyme immobilization approach using carbon nanotubes/silica as support
Authors: Du Kun , Sun Jian , Zhou Xiaoyu , Feng Wei , Jiang Xia , Ji Peijun
Published: November 2014

Multiple enzyme mixtures are attractive for the production of many compounds at an industrial level. We report a practical and novel approach for coimmobilization of two enzymes. The system consists of a silica microsphere core coated with two layers of individually immobilized enzymes. The model enzymes α‐amylase (AA) and glucoamylase (GluA) were individually immobilized on carbon nanotubes (CNTs). A CNT‐GluA layer was formed by adsorbing CNT‐GluA onto silica microsphere. A sol‐gel layer with entrapped CNT‐AA was then formed outside the CNT‐GluA/silica microsphere conjugate. The coimmobilized α‐amylase and glucoamylase exhibited 95.1% of the activity of the mixture of free α‐amylase and glucoamylase. The consecutive use exhibited a good stability of the coimmobilized enzymes. The developed approach demonstrates advantages, including controlling the ratio of coimmobilized enzymes in an easy way, facilitating diffusion of small molecules in and out of the matrix, and preventing the leaching of enzymes. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:42–47, 2015
A comparative study of monoclonal antibodies. 1. phase behavior and protein–protein interactions
Authors: Lewus Rachael A. , Levy Nicholas E. , Lenhoff Abraham M. , Sandler Stanley I.
Published: November 2014

Protein phase behavior is involved in numerous aspects of downstream processing, either by design as in crystallization or precipitation processes, or as an undesired effect, such as aggregation. This work explores the phase behavior of eight monoclonal antibodies (mAbs) that exhibit liquid–liquid separation, aggregation, gelation, and crystallization. The phase behavior has been studied systematically as a function of a number of factors, including solution composition and pH, in order to explore the degree of variability among different antibodies. Comparisons of the locations of phase boundaries show consistent trends as a function of solution composition; however, changing the solution pH has different effects on each of the antibodies studied. Furthermore, the types of dense phases formed varied among the antibodies. Protein–protein interactions, as reflected by values of the osmotic second virial coefficient, are used to correlate the phase behavior. The primary findings are that values of the osmotic second virial coefficient are useful for correlating phase boundary locations, though there is appreciable variability among the antibodies in the apparent strengths of the intrinsic protein–protein attraction manifested. However, the osmotic second virial coefficient does not provide a clear basis to predict the type of dense phase likely to result under a given set of solution conditions. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:268–276, 2015
ChemInform Abstract: A Structural Comparison of Two Thallium Copper Erbium Sulfides: TlCu3Er2S5 and Tl2Cu5Er3S8.
Authors: Eberle Marcel A. , Babo Jean‐Marie , Schleid Thomas
Published: November 2014

Orange TlCu3Er2S5 (I) is prepared by solid state reaction of a 2:1:3 molar mixture of Cu, Er, and S to which an excess TlCl is given as a flux (evacuated silica tubes, 850 °C, 8 d).
ChemInform Abstract: Sulfur as a Selectivity Modifier in a Highly Active Rh/Fe2O3/ZrO2 Catalyst for Water‐Gas Shift.
Authors: Hakeem Abrar A. , Rajendran Jaikishen , Kapteijn Freek , Makkee Michiel Makkee Michiel
Published: November 2014

The water‐gas shift selectivity and stability of a Rh/Fe2O3/ZrO2 catalyst under typical industrial conditions is improved by the presence of small amounts of sulfur (<500 ppm).
ChemInform Abstract: C2‐Symmetric N,N′‐Bis(terpenyl)ethylenediamines — Synthesis and Application in the Enantioselective Nitroaldol Reaction.
Authors: Malhotra Sanjay V. , Brown Herbert C.
Published: November 2014

Optically pure ethylenediamines are prepared and screened for the enantioselective nitroaldol reaction.
ChemInform Abstract: Nickel‐Catalyzed Asymmetric Ring Opening of Oxabenzonorbornadienes with Arylboronic Acids.
Authors: Zeng Zhongyi , Yang Dingqiao , Long Yuhua , Pan Xuejing , Huang Guobao , Zuo Xiongjun , Zhou Wen
Published: November 2014

In comparison to related transition metal‐catalyzed protocols, this procedure is characterized by utilization of a cheaper catalyst precursor, low catalyst loading, higher efficiency, enantioselectivity, and functional group tolerance.
ChemInform Abstract: Double Axial Chirality Promoted Asymmetric [2,3] Stevens Rearrangement of N‐Cinnamyl L‐Alanine Amide‐Derived Ammonium Ylides.
Authors: Tayama Eiji , Naganuma Noriko , Iwamoto Hajime , Hasegawa Eietsu
Published: November 2014

The Stevens rearrangement proceeds via a double axially chiral intermediate.
ChemInform Abstract: Trifluoroacetic Acid Catalyzed Thiophenylmethylation and Thioalkylmethylation of Lactams and Phenols via Domino Three‐Component Reaction in Water.
Authors: Vishwakarma Ram A. , et al. et al.
Published: November 2014

A facile protocol for the three component reaction of thiols and formaldehyde with lactams or isatins to give the corresponding N‐substituted compounds is presented.
ChemInform Abstract: A Pd‐Catalyzed Cascade Reaction of N—H Insertion and Oxidative Dehydrogenative Aromatization: A New Entry to 2‐Amino‐phenols.
Authors: Ding Dong , Lv Xiaobing , Li Jian , Qiu Lin , Xu Guangyang , Sun Jiangtao
Published: November 2014

The use of piperidine and pyrrolidine as amine substrates fails to give the desired products.
ChemInform Abstract: One Pot Direct Synthesis of β‐Ketoesters via Carbonylation of Aryl Halides Using Cobalt Carbonyl.
Authors: Baburajan Poongavanam , Elango Kuppanagounder P.
Published: November 2014

Microwave assisted three‐component reaction of aryl bromides and iodides with carbon monoxide and potassium mono ethyl malonate allows the synthesis of a wide variety of β‐ketoesters.
ChemInform Abstract: Novel One‐Pot Synthesis of Diverse γ,δ‐Unsaturated β‐Ketoesters by Thermal Cascade Reactions of Diazodicarbonyl Compounds and Enol Ethers: Transformation into Substituted 3,5‐Diketoesters.
Authors: Pandit Rameshwar Prasad , Lee Yong Rok
Published: November 2014

Wolff rearrangement of α‐diazo‐β‐ketoesters (I) and (IV) followed by trapping of the ketene intermediates with enol ethers (II) and (V) generates a variety of trans‐γ,δ‐unsaturated β‐ketoesters (III) and (VI), respectively.
ChemInform Abstract: Palladium Nanoparticles Supported in a Polymeric Membrane: An Efficient Phosphine‐Free “Green” Catalyst for Suzuki—Miyaura Reactions in Water.
Authors: Faria Vinicius W. , Oliveira Deyvid G. M. , Kurz Marcia H. S. , Goncalves Fabio F. , Scheeren Carla W. , Rosa Gilber R.
Published: November 2014

The title polymeric catalyst is successfully applied to Suzuki—Miyaura reactions of aryl iodides and bromides in water as the solvent.
ChemInform Abstract: An Expeditious Approach to Highly Functionalized Angularly Fused 5—5—n Ring Systems Through Ring Opening—Ring Closing Metathesis of Norbornene Derivatives.
Authors: Datta Ritabrata , Bose Sritama , Viththlbhai Pipaliya B. , Ghosh Subrata
Published: November 2014

A facile protocol is reported for the synthesis of angularly fused 5,5,5‐, 5,5,6‐ and 5,5,7‐ring systems which are present in several natural products.
ChemInform Abstract: Role of ortho‐Substituents on Rhodium‐Catalyzed Asymmetric Synthesis of β‐Lactones by Intramolecular C—H Insertions of Aryldiazoacetates.
Authors: Fu Liangbing , Wang Hengbin , Davies Huw M. L.
Published: November 2014

Oxetane products are obtained in good yields and with high levels of diastereo‐ and enantioselectivity.
ChemInform Abstract: Highly Regio‐ and Enantioselective Synthesis of Polysubstituted 2H‐Pyrroles via Pd‐Catalyzed Intermolecular Asymmetric Allylic Dearomatization of Pyrroles.
Authors: Zhuo Chun‐Xiang , Zhou Yong , You Shu‐Li
Published: November 2014

This is the first example using multisubstituted pyrroles as substrates in asymmetric allylic alkylation reactions.
ChemInform Abstract: One‐Pot Reactions of Nitroenamines with Anilines and Ethyl Glyoxylate.
Authors: Pilipecz Mihaly V. , Scheiber Pal , Vincze Zoltan , Varga Tamas R. , Toth Gabor , Nemes Peter
Published: November 2014

A novel three‐component method for the condensation of anilines, ethyl glyoxylate, and cyclic nitroenamines is described to yield multi‐substituted ethyl propiolates (IV).
ChemInform Abstract: Application of Nano SnO2 as a Green and Recyclable Catalyst for the Synthesis of 2‐Aryl or Alkylbenzoxazole Derivatives under Ambient Temperature
Authors: Vahdat Seyed Mohammad , Raz Shima Ghafouri , Baghery Saeed
Published: November 2014

via condensation reactions of 2‐aminophenols (I) with aromatic aldehydes or orthoesters
ChemInform Abstract: Mild and Efficient Synthesis of Polyfunctionalized 4H‐Pyran‐3‐carboxamide Derivatives
Authors: Pagadala Ramakanth , Maddila Suresh , Jonnalagadda Sreekanth B.
Published: November 2014

via a multicomponent reaction using water as solvent
ChemInform Abstract: Lewis Acid Promoted C—C and Copper‐Catalyzed C—O Bond Formation: Synthesis of Neoflavans.
Authors: Suchand B. , Krishna J. , Mritunjoy K. , Satyanarayana G.
Published: November 2014

A facile four‐step strategy for the synthesis of neoflavons is developed.
ChemInform Abstract: An Efficient Microwave‐Assisted Synthesis and Antimicrobial Activity of Novel 2‐Amino 3‐Cyano Pyridine Derivatives Using Two Reusable Solid Acids as Catalysts.
Authors: Thakrar Shailesh , Bavishi Abhay , Radadiya Ashish , Vala Hardevsinh , Parekh Shrey , Bhavsar Dhairya , Chaniyara Ravi , Shah Anamik
Published: November 2014

Title compounds are prepared under microwave irradiation in the presence of Fe(III)‐montmorillonite K10 or zeolite HY.
ChemInform Abstract: Facile Synthesis of 2‐Amino‐3‐bromoquinolines by Palladium‐Catalyzed Isocyanide Insertion and Cyclization of gem‐Dibromovinylanilines.
Authors: Jiang Baishan , Hu Langxi , Gui Weijun
Published: November 2014

The optimized conditions allow the synthesis of 3‐bromoquinoline derivatives in good yields from gem‐dibromovinylanilines and tert‐butylisocyanide.
ChemInform Abstract: Palladium Catalyzed, Heteroatom‐Guided C—H Functionalization in the Synthesis of Substituted Isoquinolines and Dihydroisoquinolines.
Authors: Tiwari Virendra Kumar , Pawar Govind Goroba , Jena Himanshu Sekhar , Kapur Manmohan
Published: November 2014

The crude reactions mixtures obtained after conversion of (I) or (IV) contain small to significant amounts of the corresponding 3‐arylated products which are in most cases not isolated.
ChemInform Abstract: An Efficient Ultrasound‐Assisted Synthesis of N‐Alkyl Derivatives of Carbazole, Indole, and Phenothiazine.
Authors: Zhao Sanhu , Kang Jin , Du Yuting , Kang Jingyan , Zhao Xiaoni , Xu Yinfeng , Chen Ruixi , Wang Qianqian , Shi Xitao
Published: November 2014

N‐Heterocycles (I), (VI), and (VIII) are alkylated under ultrasonic irradiation in the presence of KOH as a base.
ChemInform Abstract: Synthesis, Characterization, and Reactivity of Novel 6H‐1,3,5‐Oxathiazine S,S‐Dioxides.
Authors: Islam Md. Rafiqul , Takikawa Yuji , Lim Kwon Taek
Published: November 2014

S,S‐Dioxides (II) are prepared from oxathiazines (I) by oxidation with an excess of m‐chloroperbenzoic acid.
ChemInform Abstract: Polycyclic N‐Heterocyclic Compounds. Part 76. Synthesis and Antiplatelet Evaluation of 2,4‐Disubstituted 5,6‐Dihydro[1]benzofuro[3′,2′:2,3]oxepino[4,5‐d]pyrimidines.
Authors: Okuda Kensuke , Takano Jun‐ichi , Hirota Takashi , Sasaki Kenji , Nishina Yuta , Ishida Hiroyuki
Published: November 2014

25 Title compounds of type (IV), (VI), or (VIII) are prepared and evaluated for their antiplatelet activities.
ChemInform Abstract: Zinc Mediated Allylations of Chlorosilanes Promoted by Ultrasound: Synthesis of Novel Constrained Sila Amino Acids.
Authors: Ramesh Remya , Reddy D. Srinivasa
Published: November 2014

The prepared unsaturated organosilanes are very good starting materials for the polymer industry.
ChemInform Abstract: Water Mediated Eco‐Friendly Green Protocol for One‐Pot Synthesis of α‐Aminophosphonates at Ambient Conditions.
Authors: Mandha Santhosh Reddy , Alla Manjula , Bommena Vittal Rao
Published: November 2014

The title compounds (IV) are simply obtained by reaction of various aldehydes, amines, and trimethyl phosphite under totally solvent‐free and catalyst‐free conditions.
ChemInform Abstract: A Novel Type of Luciferin from the Siberian Luminous Earthworm Fridericia heliota: Structure Elucidation by Spectral Studies and Total Synthesis.
Authors: Petushkov Valentin N. , Dubinnyi Maxim A. , Tsarkova Aleksandra S. , Rodionova Natalja S. , Baranov Mikhail S. , Kublitski Vadim S. , Shimomura Osamu , Yampolsky Ilia V.
Published: November 2014

The fridericia luciferin (I) is a key component of a novel ATP‐dependent bioluminescence system.
ChemInform Abstract: Magnetic Entropy Change Involving Martensitic Transition in NiMn‐based Heusler Alloys
Authors: Hu Feng‐Xia , Shen Bao‐Gen , Sun Ji‐Rong
Published: November 2014

Review: 86 refs.
ChemInform Abstract: Platinum Organometallic Compounds: Classification and Analysis of Crystallographic and Structural Data of Monomeric Five and Higher Coordinated
Authors: Melnik Milan , Mikus Peter , Holloway Clive Eduard
Published: November 2014

Review: 353 refs.
ChemInform Abstract: Addition of CF3 Across Unsaturated Moieties: A Powerful Functionalization Tool
Authors: Merino Estibaliz , Nevado Cristina
Published: November 2014

Review: recent methodologies for the simultaneous formation of C—CF3 and C—C or C‐heteroatom bonds by formal addition reactions to alkenes; 70 refs.