bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal government spending in an economy with imperfectly competitive goods and labor markets
Authors: Chang Shu‐hua , Chang Juin‐jen
Published: May 2014

This article examines the growth‐ and welfare‐maximizing government spending in an economy that is characterized by market imperfections, namely, unionization in the labor market and monopolistic competition in the goods market. To thoughtfully explore the optimal spending, two distinct scenarios where the government spending is financed by labor/capital income taxes are considered. Our analysis shows that the optimal growth‐maximizing government spending is inconsistent with the welfare‐maximizing government spending. Moreover, the growth‐maximizing/welfare‐maximizing government spending have quite different responses to distinctive market imperfections (markups in the goods and labor markets), particularly in the scenarios with distinctive financing modes. Our numerical study indicates that the growth‐maximizing and welfare‐maximizing government expenditures, in general, are more responsive to the change in the labor market friction than that in the product market friction and the growth‐maximizing government spending is more likely to be lower than the welfare‐maximizing government spending.
Locating Cosmopolitanism Within Academic Mobility
Authors: Kirpitchenko Liudmila
Published: May 2014

Intensified academic mobility is an enticing platform for examining the emerging manifestations of cosmopolitanism in expanding intercultural encounters. Cosmopolitanism calls for a dialogue between cultures and for reciprocal appropriation and internalization of cultures within one’s own culture. This paper endeavors to locate empirical evidence on evolving cosmopolitanism in everyday intercultural interactions and academic experiences. It is guided by the methodological applications of cosmopolitanism and the way cosmopolitanism is redefining the sociological frame of reference. This paper presents discussion and empirical testing of three defining features of cosmopolitanism according to Beck (2002): globality, plurality and civility. Mirroring these guiding principles, this research attempted to identify and analyze cosmopolitan values and dispositions in everyday intercultural encounters, discourses, situations and experiences. This paper presented an argument that cosmopolitan values and dispositions tend to create mutually beneficial conditions for intercultural inclusion and academic mobility provides a fertile ground for their current and future exploration.
A Common Theme - Ethical Practice
Authors: Goodman James
Published: May 2014

DOI: http://dx.doi.org/10.5130/ccs.v6i1.3924
Atmospheric deposition of polybromodiphenyl ethers in remote mountain regions of Europe
Authors: Arellano L. , Fernández P. , López J. F. , Rose N. L. , Nickus U. , Thies H. , Stuchlik E. , Camarero L. , Catalan J. , Grimalt J. O.
Published: May 2014

Abstract. Polybromodiphenyl ethers (PBDEs) were analyzed in bulk atmospheric deposition collected in four European remote mountain areas over a period of two years (2004–2006): Lake Redon (Pyrenees, Catalonia, Spain), Gossenköllesee (Alps, Austria), Lochnagar (Grampian Mountains, Scotland) and Skalnate (Tatras, Slovakia). In all sites, the PBDE distributions were dominated by BDE209. BDE47 and BDE99 were the major low-brominated congeners, followed by BDE100 and BDE183. This composition is consistent with predominant inputs from the commercial mixtures decaBDE and pentaBDE. The total congener site-averaged fluxes ranged between 100 ng m−2 mo−1 (Alps) and 190 ng m−2 mo−1 (Tatras). Significant correlations between PBDE deposition and percent of North Atlantic backwards air mass trajectories in the collected samples of the westernmost sites, Lochnagar and Redon, suggested an impact of transcontinental transfer of these pollutants from North American sources into Europe. Skalnate, and to a lower extent Redon, recorded another main PBDE source from central Europe corresponding to secondary emissions of the pentaBDE commercial mixture. The fluxes of these secondary emissions were temperature dependent and correlated to total particle deposition and rainfall. Higher PBDE fluxes were observed at increasing temperature, particle deposition and precipitation. Another specific PBDE source was observed in United Kingdom and recorded in Lochnagar. Photolytic degradation during transport decreased the relative abundance of BDE209 and modified the emitted pentaBDE technical mixtures by depletion of the relative composition of BDE99 and, to a lower extent, BDE47. The transformations were more intense in the sites located above 2000 m (Redon and Gossenköllesee) and, particularly, during the warm periods.
Greenhouse gas network design using backward Lagrangian particle dispersion modelling – Part 2: Sensitivity analyses and South African test case
Authors: Nickless A. , Ziehn T. , Rayner P. J. , Scholes R. J. , Engelbrecht F.
Published: May 2014

Abstract. This is the second part of a two-part paper considering network design based on a Lagrangian stochastic particle dispersion model (LPDM), aimed at reducing the uncertainty of the flux estimates achievable for the region of interest by the continuous observation of atmospheric CO2 concentrations at fixed monitoring stations. The LPDM model, which can be used to derive the sensitivity matrix used in an inversion, was run for each potential site for the months of July (representative of the Southern Hemisphere Winter) and January (Summer). The magnitude of the boundary contributions to each potential observation site was tested to determine its inclusion in the network design, but found to be minimal. Through the use of the Bayesian inverse modelling technique, the sensitivity matrix, together with the prior estimates for the covariance matrices of the observations and surface fluxes were used to calculate the posterior covariance matrix of the estimated fluxes, used for the calculation of the cost function of the optimisation procedure. The optimisation procedure was carried out for South Africa under a standard set of conditions, similar to those applied to the Australian test case in Part 1, for both months and for the combined two months. The conditions were subtly changed, one at a time, and the optimisation routine re-run under each set of modified conditions, and compared to the original optimal network design. The results showed that changing the height of the surface grid cells, including an uncertainty estimate for the oceans, or increasing the night time observational uncertainty did not result in any major changes in the positioning of the stations relative to the basic design, but changing the covariance matrix or increasing the spatial resolution did. The genetic algorithm was able to find a slightly better solution than the incremental optimisation procedure, but did not drastically alter the solution compared to the standard case. Including correlation appeared to increase the spread in the layout of the stations. Increasing the surface resolution tended to clump the stations around areas of high activity. In conclusion, the specification used in an optimal network design should be chosen to best match the conditions under which an inversion would be run for the region of interest. Increasing the spatial resolution beyond that which the given network size could reasonably resolve may lead to a network which would ignore small areas of high activity and reduce the capacity of the network to resolve fluxes for subregions in the domain of interest. Overall the results suggest that a good improvement in knowledge of South African fluxes is available from a feasible atmospheric network and that the general features of this network are robust to many reasonable choices in a network design study.
Spatial variability in iron nutritional status of large diatoms in the Sea of Okhotsk with special reference to the Amur River discharge
Authors: Suzuki K. , Hattori-Saito A. , Sekiguchi Y. , Nishioka J. , Shigemitsu M. , Isada T. , Liu H. , McKay R. M. L.
Published: May 2014

Abstract. The Sea of Okhotsk is known as one of the most biologically productive regions among the world's oceans, and its productivity is supported in part by the discharge of iron (Fe)-rich water from the Amur River. However, little is known about the effect of riverine-derived Fe input on the physiology of the large diatoms which often flourish in surface waters of the productive continental shelf region. We conducted diatom-specific immunochemical ferredoxin (Fd) and flavodoxin (Fld) assays in order to investigate the spatial variability of Fe nutritional status in the microplankton-sized (20–200 μm; hereafter micro-sized) diatoms. The Fd index, defined as the proportion of Fd to the sum of Fd plus Fld accumulations in the cells, was used to assess their Fe nutritional status. Additionally, active chlorophyll fluorescence measurements using pulse–amplitude-modulated (PAM) fluorometry were carried out to obtain the maximum photochemical quantum efficiency (Fv/Fm) of photosystem II for the total micro-sized phytoplankton assemblages including diatoms. During our observations in the summer of 2006, the micro-sized diatoms were relatively abundant (> 10 μg C L−1) in the neritic region, and formed a massive bloom in Sakhalin Bay near the mouth of the Amur River. Values of the Fd index and Fv/Fm were high (>0.9 and >0.65, respectively) near the river mouth, indicating that Fe was sufficient for growth of the diatoms. However, in oceanic waters of the Sea of Okhotsk, the diatom Fd index declined as cellular Fld accumulation increased. These results suggest that there was a distinct gradient in Fe nutritional status in the micro-sized diatoms from near the Amur River mouth to open waters in the Sea of Okhotsk. A significant correlation between dissolved Fe (D-Fe) concentration and the Fd index was found in waters off Sakhalin Island, indicating that D-Fe was a key factor for the photophysiology of this diatom size class. In the vicinity of the Kuril Islands between the Sea of Okhotsk and the Pacific Ocean, micro-sized diatoms only accumulated Fld (i.e., Fd index = 0), despite strong vertical mixing consistent with elevated surface D-Fe levels (>0.4 nM). Since higher Fe quotas are generally required for diatoms growing under low-light conditions, the micro-sized diatoms off the Kuril Islands possibly encountered Fe and light co-limitations. The differential expressions of Fd and Fld in micro-sized diatoms helped us to understand how these organisms respond to Fe availability in the Sea of Okhotsk in connection with the Amur River discharge.
Response of plant community composition and productivity to warming and nitrogen deposition in a temperate meadow ecosystem
Authors: Zhang T. , Guo R. , Gao S. , Guo J. X. , Sun W.
Published: May 2014

Abstract. Climate change has profound influences on plant community composition and ecosystem functions. However, its effects on plant community composition and net primary productivity are not well understood. A field experiment was conducted to examine the effects of warming, nitrogen (N) addition, and their interactions on plant community composition and productivity in a temperate meadow ecosystem in northeast China. Experimental warming significantly increased species richness, evenness and diversity, by contrast, N addition highly reduced species richness, evenness and diversity. Warming reduced the importance value of gramineous species but increased in forbs, N addition had the opposite effect. Warming had a significant positive effect on belowground productivity, but had a negative effect on aboveground biomass. The influences of warming on aboveground productivity were dependent on precipitation. Experimental warming had little effect on aboveground productivity in the years with higher precipitation, but significantly suppressed the growth of aboveground in dry years. Our results suggest that warming had indirect effects on plant productivity via altering water availability. Nitrogen addition significantly increased above- and belowground productivity, suggesting that N is one of the most important limiting factors which determine plant productivity in the studied meadow steppe. Significant interactive effects of warming plus N addition on belowground productivity were also detected. Our observations revealed that climate changes (warming and N deposition) plays significant roles in regulating plant community composition and productivity in temperate meadow steppe.
Modeling stomatal conductance in the Earth system: linking leaf water-use efficiency and water transport along the soil-plant-atmosphere continuum
Authors: Bonan G. B. , Williams M. , Fisher R. A. , Oleson K. W.
Published: May 2014

Abstract. The empirical Ball–Berry stomatal conductance model is commonly used in Earth system models to simulate biotic regulation of evapotranspiration. However, the dependence of stomatal conductance (gs) on vapor pressure deficit (Ds) and soil moisture must both be empirically parameterized. We evaluated the Ball–Berry model used in the Community Land Model version 4.5 (CLM4.5) and an alternative stomatal conductance model that links leaf gas exchange, plant hydraulic constraints, and the soil–plant–atmosphere continuum (SPA) to numerically optimize photosynthetic carbon gain per unit water loss while preventing leaf water potential dropping below a critical minimum level. We evaluated two alternative optimization algorithms: intrinsic water-use efficiency (Δ An/Δ gs, the marginal carbon gain of stomatal opening) and water-use efficiency (Δ An/Δ El, the marginal carbon gain of water loss). We implemented the stomatal models in a multi-layer plant canopy model, to resolve profiles of gas exchange, leaf water potential, and plant hydraulics within the canopy, and evaluated the simulations using: (1) leaf analyses; (2) canopy net radiation, sensible heat flux, latent heat flux, and gross primary production at six AmeriFlux sites spanning 51 site–years; and (3) parameter sensitivity analyses. Without soil moisture stress, the performance of the SPA stomatal conductance model was generally comparable to or somewhat better than the Ball–Berry model in flux tower simulations, but was significantly better than the Ball–Berry model when there was soil moisture stress. Functional dependence of gs on soil moisture emerged from the physiological theory linking leaf water-use efficiency and water flow to and from the leaf along the soil-to-leaf pathway rather than being imposed a priori, as in the Ball–Berry model. Similar functional dependence of gs on Ds emerged from the water-use efficiency optimization. Sensitivity analyses showed that two parameters (stomatal efficiency and root hydraulic conductivity) minimized errors with the SPA stomatal conductance model. The critical stomatal efficiency for optimization (ι) was estimated from leaf trait datasets and is related to the slope parameter (g1) of the Ball–Berry model. The optimized parameter value was consistent with this estimate. Optimized root hydraulic conductivity was consistent with estimates from literature surveys. The two central concepts embodied in the stomatal model, that plants account for both water-use efficiency and for hydraulic safety in regulating stomatal conductance, imply a notion of optimal plant strategies and provide testable model hypotheses, rather than empirical descriptions of plant behavior.
Comparison of drought indicators derived from multiple data sets over Africa
Authors: Naumann G. , Dutra E. , Barbosa P. , Pappenberger F. , Wetterhall F. , Vogt J. V.
Published: May 2014

Abstract. Drought monitoring is a key component to mitigate impacts of droughts. Lack of reliable and up-to-date precipitation data sets is a common challenge across the globe. This study investigates different data sets and drought indicators on their capability to improve drought monitoring in Africa. The study was performed for four river basins located in different climatic regions (the Oum er-Rbia in Morocco, the Blue Nile in eastern Africa, the Upper Niger in western Africa, and the Limpopo in southeastern Africa) as well as the Greater Horn of Africa. The five precipitation data sets compared are the ECMWF ERA-Interim reanalysis, the Tropical Rainfall Measuring Mission satellite monthly rainfall product 3B-43, the Global Precipitation Climatology Centre gridded precipitation data set, the Global Precipitation Climatology Project Global Monthly Merged Precipitation Analyses, and the Climate Prediction Center Merged Analysis of Precipitation. The set of drought indicators used includes the Standardized Precipitation Index, the Standardized Precipitation-Evaporation Index, and Soil Moisture Anomalies. A comparison of the annual cycle and monthly precipitation time series shows a good agreement in the timing of the rainy seasons. The main differences between the data sets are in the ability to represent the magnitude of the wet seasons and extremes. Moreover, for the areas affected by drought, all the drought indicators agree on the time of drought onset and recovery although there is disagreement on the extent of the affected area. In regions with limited rain gauge data the estimation of the different drought indicators is characterized by a higher uncertainty. Further comparison suggests that the main source of differences in the computation of the drought indicators is the uncertainty in the precipitation data sets rather than the estimation of the distribution parameters of the drought indicators.
Sedimentological characteristics of ice-wedge polygon terrain in Adventdalen (Svalbard). Environmental and climatic implications for the Late Holocene
Authors: Oliva M. , Vieira G. , Pina P. , Pereira P. , Neves M. , Freitas M. C.
Published: May 2014

Abstract. Ice-wedges are widespread periglacial features in the landscape of Adventalen, Svalbard. The networks of ice-wedges have created areas with well-developed polygonal terrains in the lowest fluvial terraces in this valley. We have examined the sedimentological characteristics of the northern and southern banks of the Advent river for palaeoenvironmental purposes. The base of two sedimentary sections reported radiocarbon dates of 3.3 and 3.9 ka cal BP, respectively. The northern site is constituted by three very different lithostratigraphical units, which suggests that their formation should be related to different environmental and climate conditions. By contrast, the southern section shows a rather homogeneous composition, with no significant variations in grain size and organic matter content. In both cases the uppermost sediments are constituted by a thick aeolian deposit. According to our data, warmer climate conditions may have prevailed during the Mid Holocene until 3.3 ka cal BP with widespread peat formation in the valley bottom. Subsequently, a period with alternating soil formation and aeolian sedimentation took place from 3 to 2.5 ka cal BP, probably due to increasing climatic severity. During the last millennium a long-term cooling trend has favoured aeolian deposition in the lowest Adventalen valley.
High-resolution 900 year volcanic and climatic record from the Vostok area, East Antarctica
Authors: Osipov E. Y. , Khodzher T. V. , Golobokova L. P. , Onischuk N. A. , Lipenkov V. Y. , Ekaykin A. A. , Shibaev Y. A. , Osipova O. P.
Published: May 2014

Abstract. Ion chromatography measurements of 1730 snow and firn samples obtained from three short cores and one pit in the Vostok station area, East Antarctica, allowed for the production of the combined volcanic record of the last 900 years (AD 1093–2010). The resolution of the record is 2–3 samples per accumulation year. In total, 24 volcanic events have been identified, including seven well-known low-latitude eruptions (Pinatubo 1991, Agung 1963, Krakatoa 1883, Tambora 1815, Huanaputina 1600, Kuwae 1452, El Chichon 1259) found in most of the polar ice cores. In comparison with three other East Antarctic volcanic records (South Pole, Plateau Remote and Dome C), the Vostok record contains more events within the last 900 years. The differences between the records may be explained by local glaciological conditions, volcanic detection methodology, and, probably, differences in atmospheric circulation patterns. The strongest volcanic signal (both in sulfate concentration and flux) was attributed to the AD 1452 Kuwae eruption, similar to the Plateau Remote and Talos Dome records. The average snow accumulation rate calculated between volcanic stratigraphic horizons for the period AD 1260–2010 is 20.9 mm H2O. Positive (+13%) anomalies of snow accumulation were found for AD 1661–1815 and AD 1992–2010, and negative (−12%) for AD 1260–1601. We hypothesized that the changes in snow accumulation are associated with regional peculiarities in atmospheric transport.
Pulmonary Embolism after Arthroscopic Rotator Cuff Repair: A Case Report
Authors: Gwark Ji Yong , Koh Jin Sin , Park Hyung Bin
Published: May 2014

Pulmonary embolism (PE) is a serious complication that can occur after orthopedic surgery. Most instances of PE in the orthopedic field have occurred after hip or knee arthroplasties or after fracture surgeries. The occurrence of PE related to arthroscopic shoulder surgery is very rare. We report a case of PE that developed after arthroscopic rotator cuff repair, in which the patient did not show preoperatively any remarkable risk factors for PE. We also review the current literature related to this topic.
Imaging of uncommon peritoneal diseases
Authors: Srisajjakul Sitthipong , Tiengsittiwat Chanika , Bangchokdee Sirikan
Published: May 2014

Among peritoneal diseases, a well recognized lesion is peritoneal carcinomatosis which is the most frequently found neoplastic disease that involves the peritoneal cavity. However, there are many uncommon peritoneal diseases including malignant peritoneal mesothelioma, primary sclerosing encapsulating peritonitis, intraperitoneal loose body,peritoneal ecchinococcosis, primary serous papillary carcionoma of peritoneum, extrapelvic endometriosis, ruptured ovarian teratoma with peritoneal dissemination and peritoneal inclusion cyst. Knowledge of those imaging findings is helpful in making diagnosis or narrowing differential diagnosis.
Effect of Gamma Irradiation on Aflatoxins and Ochratoxin A Reduction in Almond Samples
Authors: Vita Di Stefano , Rosa Pitonzo , Giuseppe Avellone
Published: May 2014

The widespread contamination of food by mycotoxins may present a serious hazard to human and animal health. The gamma rays were applied to reduce ochratoxin A (OTA) and aflatoxins B1, B2, G1 and G2 (AFB1, AFB2, AFG1 and AFG2) in almonds artificially contaminated. In the present study we investigated the effect of gamma irradiation dosages, ranging from 0 to 15 kGy and the reduction of mycotoxins concentration in almond samples. In order to determine the efficiency of the method, a high-performance liquid chromatography method with fluorescence detection was used, the mycotoxins were extracted from almond samples and then purified with immunoaffinity columns. The maximum reduction was found at 15 kGy and it was 19.25%, 10.99%, 21.11%, 16.62%, 23.90% for AFB1, AFB2, AFG1, AFG2 and OTA respectively. Results showed that gamma radiations even at 15 kGy, were not effective in completely destroying aflatoxins and ochratoxin A.
A influência da qualidade do e-service bancário na satisfação com o serviço
Authors: Xavier Júnior Antonio Erivando , Batista Sales Luciana , Kato Heitor Takashi , Francisco Maffezzolli Eliane Cristine
Published: May 2014

O setor de serviços tem demonstrado crescente importância na economia brasileira. Especialmente no setor bancário, o investimento em serviços on-line oferece maior comodidade ao consumidor e menor custo de operação à empresa, e tem crescido muito nos últimos anos. Nesse contexto, esta pesquisa tem visa analisar se a qualidade do e-service bancário resulta em níveis mais elevados de satisfação com o serviço. Para isso, utilizou-se a escala E-SERVQUAL de Herington e Weaven (2009) e de satisfação com o serviço de Ribbink et al. (2004). Essas escalas foram compostas por 20 itens, distribuídos entre as dimensões: eficiência do site, necessidades pessoais, facilidade deutilização, organização do site e satisfação. Foram utilizados 204 questionários válidos, com a coleta realizada via online, com usuários do serviço em questão. Os resultados revelam que o modelo de mensuração da qualidade dos e-services parece adequado, com ênfase para a dimensão de eficiência do site. A hipótese da pesquisa foi testada com a utilização da Modelagem de Equações Estruturais, tendo como método de extração o Maximum Likelihood – ML. Foi observado o impacto positivo e significativo da qualidade do e-service bancário sobre a satisfação com o serviço. Esse resultado reforça a importância do investimento em serviços online que proporcionem eficiência, comodidade e agilidade dos serviços bancários para o consumidor final.
Estrutura do ensino superior brasileiro: um diagnóstico estratégico societário
Authors: Ferreira dos Reis Julio Adriano , Rocha da Rosa Martins Roberta , Gaio Jorge , Michelon Lohmann Luci
Published: May 2014

O ensino superior brasileiro encontra-se numa perspectiva crescente jamais percebida na história do país. Tal afirmação é baseada na proposta de democratização do acesso da população de baixa renda ao ensino superior, que prevê a meta de prover educação superior de qualidade a no mínimo 30% da população de 18 a 24 anos no período de 10 anos (2005-2015). Atento a tal resolução, o Governo Federal brasileiro lançou o Programa Universidade para Todos (PROUNI), instituído por meio da lei 11.096/05, que oferece bolsas nas modalidades parcial e integral. Nesse sentido, a presente pesquisa expost-facto, de característica descritiva e de levantamento, tem como objetivo principal, por meio de análise de dados secundários, de amostra aleatória estratificada, apresentar o contexto geral do ensino superior brasileiro em suas variáveis geográficas, societárias e tributárias, possibilitando mensurar e sugerir posicionamentos estratégicos a novas políticas públicas e empresariais. Assim sendo, percebe-se que a variável geográfica demonstra de forma clara a centralidade das IES nas regiões Sudeste e Sul, o que acarreta o perfil de desigualdade territorial entre as diferentes regiões. Sobre os aspectos societários, percebe-se que a educação superior brasileira está centrada principalmente na iniciativa privada, pelas faculdades majoritariamente. Importante também a complexidade tributária praticada pelas IES brasileiras, à medida que suas opções e enquadramentos permeiam uma série de possibilidades, que podem sugerir oportunidades de geração de economia para as IES, bem como para o Estado, por meio da renúncia ou imunidade fiscal relacionada à aderência de programas de desenvolvimento do ensino superior como o PROUNI.
O retrato
Authors: Peralva Osvaldo
Published: May 2014

O retrato é um dos mais importantes e contundentes relatos políticos brasileiros do século XX. Fervoroso militante e membro da cúpula do Partido Comunista Brasileiro, o jornalista e escritor Osvaldo Peralva foi enviado a Moscou em 1953 para estudar. Lá constatou que a utopia bolchevista havia se convertido em pesadelo totalitário. Três anos depois, quando voltou ao Brasil, percebeu que o PCB reproduzia em escala provinciana e farsesca tanto o terrorismo ideológico quanto o culto à personalidade que prevaleciam na URSS. O livro é a história da trajetória de Peralva no Partido Comunista, desde a apaixonada adesão na juventude até a traumática ruptura no final dos anos 1950. Com a argúcia de um repórter e a verve de um romancista, ele transforma suas memórias em arrebatadora narrativa sobre os bastidores sinistros do comunismo na União Soviética e os descaminhos do PCB, traçando retratos implacáveis de seus líderes, como Luís Carlos Prestes e Carlos Marighella.
Cerebellar modules operate at different frequencies
Authors: Zhou Haibo , Lin Zhanmin , Voges Kai , Ju Chiheng , Gao Zhenyu , Bosman Laurens WJ , Ruigrok Tom JH , Hoebeek Freek E , De Zeeuw Chris I , Schonewille Martijn
Published: May 2014

Due to the uniform cyto-architecture of the cerebellar cortex, its overall physiological characteristics have traditionally been considered to be homogeneous. In this study, we show in awake mice at rest that spiking activity of Purkinje cells, the sole output cells of the cerebellar cortex, differs between cerebellar modules and correlates with their expression of the glycolytic enzyme aldolase C or zebrin. Simple spike and complex spike frequencies were significantly higher in Purkinje cells located in zebrin-negative than zebrin-positive modules. The difference in simple spike frequency persisted when the synaptic input to, but not intrinsic activity of, Purkinje cells was manipulated. Blocking TRPC3, the effector channel of a cascade of proteins that have zebrin-like distribution patterns, attenuated the simple spike frequency difference. Our results indicate that zebrin-discriminated cerebellar modules operate at different frequencies, which depend on activation of TRPC3, and that this property is relevant for all cerebellar functions.
Prospective identification of functionally distinct stem cells and neurosphere-initiating cells in adult mouse forebrain
Authors: Mich John K , Signer Robert AJ , Nakada Daisuke , Pineda André , Burgess Rebecca J , Vue Tou Yia , Johnson Jane E , Morrison Sean J
Published: May 2014

Neurosphere formation is commonly used as a surrogate for neural stem cell (NSC) function but the relationship between neurosphere-initiating cells (NICs) and NSCs remains unclear. We prospectively identified, and isolated by flow cytometry, adult mouse lateral ventricle subventricular zone (SVZ) NICs as GlastmidEGFRhighPlexinB2highCD24−/lowO4/PSA-NCAM−/lowTer119/CD45− (GEPCOT) cells. They were highly mitotic and short-lived in vivo based on fate-mapping with Ascl1CreERT2 and Dlx1CreERT2. In contrast, pre-GEPCOT cells were quiescent, expressed higher Glast, and lower EGFR and PlexinB2. Pre-GEPCOT cells could not form neurospheres but expressed the stem cell markers Slc1a3-CreERT, GFAP-CreERT2, Sox2CreERT2, and Gli1CreERT2 and were long-lived in vivo. While GEPCOT NICs were ablated by temozolomide, pre-GEPCOT cells survived and repopulated the SVZ. Conditional deletion of the Bmi-1 polycomb protein depleted pre-GEPCOT and GEPCOT cells, though pre-GEPCOT cells were more dependent upon Bmi-1 for Cdkn2a (p16Ink4a) repression. Our data distinguish quiescent NSCs from NICs and make it possible to study their properties in vivo.
Association of consecutive Pi2‐Ps6 band pulsations with earthward fast flows in the plasma sheet in response to IMF variations
Authors: Cheng Ching‐Chang , Mann Ian R. , Baumjohann Wolfgang
Published: May 2014

On 11 March 2009, the H component had four consecutive bay‐like variations accompanied by positive and negative deflections in the D component across the Atlantic like those affected by the substorm current wedge formation. A train of pulsations with a frequency range 2–10 mHz (referred to as Pi2‐Ps6 band), sensed by Time History of Events and Macroscale Interactions during Substorms (THEMIS)/Canadian Array for Real‐time Investigations of Magnetic Activity (CARISMA) magnetometers, had clearly three consecutive Pi2s followed by a Ps6 at low latitudes, but first Pi2 and then Ps6 at high latitudes mixed with large‐amplitude Ps6 at midlatitudes. The geostationary orbit magnetometers sensed similar magnetic perturbations. THEMIS probes first observed earthward fast flows, magnetic dipolarizations, and modulated energetic particle fluxes at ~ XGSM −9.2 RE, then at ~ XGSM −7.5 RE for Pi2 and at ~ XGSM −18.0 RE only for Ps6. They appeared during a very quiet period for northward interplanetary magnetic field (IMF) with a clock angle variation of low to high and then low. The H spectrum shows two harmonic frequencies ~2–4 mHz and ~8–10 mHz but the D spectrum one dominant frequency ~2–4 mHz. Pi2 can result from a combination of fast magnetospheric and plasmaspheric cavity resonances and Ps6 from a fast magnetospheric cavity resonance. The surface waves at the interface separating braking earthward fast flows from the ambient plasma convection region could lead to large‐amplitude Ps6 at midlatitudes. Hence, consecutive Pi2‐Ps6 band pulsations can be associated with earthward fast flows in the plasma sheet, expectedly driven by magnetotail reconnection, respectively, in the near‐Earth region and the distant Earth one in response to IMF variations as in the two‐neutral‐point model.
Investigation of the temperature gradient instability as the source of midlatitude quiet time decameter‐scale ionospheric irregularities: 1. Observations
Authors: de Larquier S. , Eltrass A. , Mahmoudian A. , Ruohoniemi J. M. , Baker J. B. H. , Scales W. A. , Erickson P. J. , Greenwald R. A.
Published: May 2014

Super Dual Auroral Radar Network (SuperDARN) radars regularly observe decameter‐scale ionospheric irregularities at midlatitudes during quiet geomagnetic conditions. The mechanism responsible for the growth of such irregularities is still unknown. Previous results based on data from the Wallops SuperDARN HF radar and Incoherent Scatter Radar have suggested that the Temperature Gradient Instability (TGI) could be responsible for only part of the observed irregularities. This conclusion was reached based on the relative orientation of horizontal electron temperature and density gradients. However, the TGI theory requires driving gradients to be perpendicular to perpendicular to the geomagnetic field B. Since midlatitude field lines are approximately 20° off vertical, we have reexamined the original data and computed gradients along the meridional direction perpendicular to B. Distinctions have to be made between the topside and bottomside F region due to the strong influence of vertical gradients. We find that the TGI growth is possible in the topside F region for the duration of the experiment, even before irregularities were observed. We show that the absence of observed irregularities during favorable TGI growth conditions is not a consequence of HF propagation but of higher E region electron irregularity growth. We conclude that the TGI is a valid mechanism to explain the generation of all irregularities observed during the experiment.
Investigation of the temperature gradient instability as the source of midlatitude quiet time decameter‐scale ionospheric irregularities: 2. Linear analysis
Authors: Eltrass A. , Mahmoudian A. , Scales W. A. , de Larquier S. , Ruohoniemi J. M. , Baker J. B. H. , Greenwald R. A. , Erickson P. J.
Published: May 2014

Previous joint measurements by the Millstone Hill incoherent scatter radar and the Super Dual Auroral Radar Network (SuperDARN) HF radar located at Wallops Island, Virginia, have identified the presence of opposed meridional electron density and temperature gradients in the region of decameter‐scale electron density irregularities that have been proposed to be responsible for low‐velocity Sub‐Auroral Ionospheric Scatter observed by SuperDARN radars. The temperature gradient instability (TGI) and the gradient drift instability (GDI) have been extended into the kinetic regime appropriate for SuperDARN radar frequencies and investigated as the causes of these irregularities. A time series for the growth rate of both TGI and GDI has been developed for midlatitude ionospheric irregularities observed by SuperDARN Greenwald et al. (2006). The time series is computed for both perpendicular and meridional density and temperature gradients. This growth rate comparison shows that the TGI is the most likely generation mechanism for the irregularities observed during the experiment and the GDI is expected to play a relatively minor role in irregularity generation.
Observations of gas phase hydrochloric acid in the polluted marine boundary layer
Authors: Crisp Timia A. , Lerner Brian M. , Williams Eric J. , Quinn Patricia K. , Bates Timothy S. , Bertram Timothy H.
Published: May 2014

Ship‐based measurements of gas phase hydrochloric acid (HCl), particulate chloride (pCl−), and reactive nitrogen oxides (NOy) were made in the polluted marine boundary layer along the California coastline during spring 2010. These observations are used to assess both the rate of Cl atom production from HCl and the role of direct HCl emissions and subsequent partitioning as a source for pCl−. Observations of HCl made in coastal Southern California are broadly correlated with NOz (NOz ≡ NOy – NOx), peaking at 11 A.M. The observed median HCl mixing ratio in Southern California is 1.3 ppb (interquartile range: 0.53–2.7 ppb), as compared to 0.19 ppb (interquartile range: 0.10–0.38 ppb) measured along the Sacramento River between San Francisco and Sacramento. Concurrent measurements of aerosol ion chemistry indicate that aerosol particles sampled in Northern California are heavily depleted in Cl−, corresponding to a mean pCl− deficit of 0.05 ± 0.03 (1σ) ppb for sub‐10 µm aerosol particles. In comparison, aerosols measured in Southern California indicate that over 25% of particles showed an addition of Cl− to the particle population. Observations presented here suggest that primary sources of HCl, or gas phase chlorine precursors to HCl, are likely underestimated in the California Air Resource Board emissions inventory. These results highlight the need for future field observations designed to better constrain direct reactive halogen emissions.
Theoretical and numerical analysis of radiation belt electron precipitation by coherent whistler mode waves
Authors: Harid V. , Gołkowski M. , Bell T. , Inan U. S.
Published: May 2014

The interaction between coherent whistler mode waves and energetic radiation belt electrons can result in pitch angle scattering of electrons into the bounce loss cone and subsequent precipitation. In studying the effects of VLF transmitter signals on particle precipitation, past modeling efforts have focused on the computation of diffusion coefficients for a Fokker‐Planck model. In contrast, to capture the nonlinear effects of large‐amplitude coherent waves, we evaluate particle precipitation using a Vlasov‐Liouville (VL) model which computes the phase space particle distribution function directly using a characteristic‐based solution of the Vlasov equation. Previous work has shown that in the case of large‐amplitude coherent waves, phase trapping can significantly perturb resonant particles from their adiabatic paths. We evaluate the importance of phase trapping over a range of wave amplitudes (up to 200 pT); the percentage of particles that precipitate after being phase trapped is computed over a phase space grid in the loss cone. The results demonstrate that phase trapping contributes significantly to precipitation when a large‐amplitude wave (>100 pT) is present. Additionally, linear theory can be valid over a broad range of amplitudes and the relative accuracy of linear theory in calculating the precipitated flux depends strongly on the initial particle distribution. Additionally, we demonstrate the ability of the VL model to calculate the time evolution of the precipitated flux due to short‐duration whistler mode pulses. The physical parameters used in this study are typical of those associated with the Siple Station wave injection experiment.
Gravity wave signatures in the dip equatorial ionosphere‐thermosphere system during the annular solar eclipse of 15 January 2010
Authors: Manju G. , Madhav Haridas M. K. , Ramkumar G. , Pant Tarun K. , Sridharan R. , Sreelatha P.
Published: May 2014

The present work pertains to the eclipse‐induced gravity wave modulations in the ionosphere‐thermosphere region over Trivandrum (8.5°N, 77°E, dip 2°N) during the annular solar eclipse of 15 January 2010. Electron density and neutral wind rocket payload measured horizontal winds and electron densities at E region altitudes, and ionosonde‐derived foF1 and foF2 parameters are used to analyze the characteristics of the eclipse‐induced gravity waves. The analysis reveals an intensification of gravity waves with periods around 30–100 min during the peak phase of the eclipse. The vertical wavelength of the prevalent wave is found to be around 2 km. The role of gravity wave‐induced winds in generating blanketing Es over the equator is also examined.
Pulsating nighttime magnetic background noise in the upper ULF band at low latitudes
Authors: Bösinger T. , Demekhov A. G. , Ermakova E. N. , Haldoupis C. , Zhou Q.
Published: May 2014

We model long‐period (~2 h) irregular pulsations in the ellipticity of magnetic background noise (MBN) in the upper ULF band which were frequently observed during nighttime at a low‐latitude site on the Island of Crete. It is shown that such pulsations cannot be reproduced in the calculations when using the ionosphere parameters from the statistical IRI (International Reference Ionosphere) model, while regular diurnal signatures of the ellipticity spectrum at sunset and sunrise are successfully reproduced. We apply the same approach to the location of the Arecibo incoherent scatter radar and show that using actually measured ionosphere profiles (up to a height of 400 km) instead of IRI profiles produces the ellipticity pulsations very similar to those observed at Crete. Comparison of model results with the calculated behavior of Alfvén mode refractive index allows us to conclude that the observed nighttime long‐period irregular pulsations in the MBN ellipticity are caused by dynamic processes at the upper boundary of the ionospheric E‐F valley which serves as a subionospheric Alfvén resonator. Irregular widening, shrinking, and/or deepening of the valley with time scales of 1 to 4 h affect the electrodynamical properties of this resonator and manifest themselves in the magnetic background noise properties.
EMHD theory and observations of electron solitary waves in magnetotail plasmas
Authors: Ji Xiao‐Fei , Wang Xiao‐Gang , Sun Wei‐Jie , Xiao Chi‐Jie , Shi Quan‐Qi , Liu Jiang , Pu Zu‐Yin
Published: May 2014

A new approach of electron magnetohydrodynamics (EMHD) is developed by including the anisotropy of the electron pressure tensor to take Biermann battery effect into account. Based on the model, the dispersion relation of slow and fast electron magnetosonic modes are derived. A Korteweg‐de Vries equation is then obtained from the wave equation to get a solution of one‐dimensional slow‐mode soliton. Furthermore, according to measurements of Cluster and Time History of Events and Macroscale Interactions during Substorms, we find a good agreement between the theory and observations of magnetic field depression and perpendicular pressure increase.
Thermo‐poro‐mechanics of chemically active creeping faults: 3. The role of serpentinite in episodic tremor and slip sequences, and transition to chaos
Authors: Poulet T. , Veveakis E. , Regenauer‐Lieb K. , Yuen D. A.
Published: May 2014

During the last decade, knowledge over episodic tremor and slip (ETS) events has increased dramatically owing to the widespread installation of GPS and seismic networks. The most puzzling observations are (i) the periodic nature of slow seismic events, (ii) their localization at intermediate depths (estimated 15–40 km), and (iii) the origin of the nonvolcanic fluids that are responsible for the tremor activity. We reconcile these observations using a first principles approach relying on physics, continuum mechanics, and chemistry of serpentinite in the megathrust interface. The approach reproduces the GPS sequences of 17 years of recording in Cascadia, North America, as well as over 10 years in the Hikurangi Trench of New Zealand. We show that strongly endothermic reactions, such as serpentinite dehydration, are required for ETS events. We report that in this tectonic setting, it is its chemical reaction kinetics, not the low friction, that marks serpentinite as a key mineral for stable, self‐sustained oscillations. We find that the subduction zone instabilities are driven from the ductile realm rather than the brittle cover. Even when earthquakes in the cover perturb the oscillator, it relaxes to its fundamental mode. Such a transition from stable oscillations to chaos is witnessed in the ETS signal of NZ following the M6.8, 2007 seismic event, which triggered a secondary mode of oscillations lasting for a few years. We consequently suggest that the rich dynamics of ductile modes of failure may be used to decipher the chaotic time sequences underpinning seismic events.
Binding Functions of Microbe Cement
Authors: Rong Hui , Qian Chun‐Xiang
Published: May 2014

Microbe cement as a new technique of consolidating loose particles has drawn much attention because of the ever increasing awareness of environmental protection. The technique relies on the microbial‐induced calcite precipitation at particle–particle contacts and around individual particles. In order to further explain the binding essence of microbe cement, this paper firstly compares the effect of cementing loose particles by microbial calcite cement with that by chemical precipitated calcite. Moreover, the morphology of calcite produced by above‐mentioned two methods and the microstructure between calcite and loose sand particles are analyzed by transmission electron microscope (TEM), infra‐red spectra (IR), X‐ray photoelectron spectroscopy (XPS), and nuclear magnetic resonance (NMR), respectively. The TEM results indicate that the microbial calcite consists of many fine grains with irregular shape, however, the chemical calcite has significant growth steps. The IR, XPS, and NMR results all show that the microbial‐induced precipitation of calcite in loose sand particles interacts with other particles to generate hydrogen bond, which play a role in binding function between loose sand particles and calcite produced by microbe cement.
Triboelectric Nanogenerators as a Self‐Powered Motion Tracking System
Authors: Chen Mengxiao , Li Xiaoyi , Lin Long , Du Weiming , Han Xun , Zhu Jing , Pan Caofeng , Wang Zhong Lin
Published: May 2014

Motion tracking is a key area of sensor systems for security, transportation, and high‐tech industry. In this work, a self‐powered motion tracking system is developed to monitor moving speed, direction, acceleration, starting and ending positions, and even the moving path of a moving object. Such a system is based on a set of triboelectric nanogenerators (TENGs) that are composed of two friction layers with opposite triboelectric polarities (Kapton and Aluminum) and operates in the sliding mode. Velocities of a moving object are monitored from −0.1 m s‐1 to +0.1 m s‐1 at a step of 0.01 m s‐1, and accelerations from −0.1 m s‐2 to +0.1 m s‐2 at a step of 0.02 m s‐2. Furthermore, an 8 × 8 two‐dimensional coordinates system with 16 groups of TENGs is created, and the moving path of an object is obtained. This study opens up a new area of TENGs as active sensors with great potential in self‐powered systems, positioning detecting, motion tracking, environmental and infrastructure monitoring, and security.
Directed Ruthenium‐Catalyzed C(sp3)H α‐Alkylation of Cyclic Amines Using Dioxolane‐Protected Alkenones
Authors: Kulago Artem A. , Van Steijvoort Ben F. , Mitchell Emily A. , Meerpoel Lieven , Maes Bert U. W.
Published: May 2014

A catalytic system for ruthenium‐catalyzed C(sp3)H α‐alkylation of piperidines with dioxolane‐protected alkenones is reported. Dioxolane protection of the ketone proved crucial to obtain alkylation products. A diverse set of highly substituted piperidines was readily prepared in moderate to good yields via this methodology from easily accessible starting materials (C‐2, C‐3 and C‐4 substituted piperidines). When the methodology is applied to C‐3 substituted piperidines, featuring two α positions, only monoalkylated products (2,5‐disubstituted) are observed. Even bicyclic amines, which feature a fused piperidine moiety, can be used. The successful directing group as well as protecting group (ketal) removal is also demonstrated. The methodology thus allows one to further derivatize and access hitherto unknown functionalized cyclic amine derivatives and will be useful in molecular library synthesis.

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