bluuebunny/crossref_metadata_2025 huggingface dataset:
The network dimensions of intra-organizational social capital
Authors: Nonino Fabio
Published: January 2014

The article provides the results of research carried out within the organizational social capital theory and the network theory of organizations. The research contributes to these theories by identifying, through an analysis of the literature, 10 informal network sources of intra-organizational social capital. A model for representing and measuring intra-organizational social capital based on the 10 informal organizational networks identified and on three different conceptual perspectives (structural, relational and cognitive) is subsequently proposed. The model is validated through an empirical study conducted within five divisions of a knowledge-intensive company. The research results suggest that among the 10 informal relationships studied, the accessibility of individuals primarily predicts the emergence of more informal relationships, which are the real source of intra-organizational social capital through resource exchange and combination. Furthermore a continuous working cooperation and the willingness of colleagues to make themselves available for cooperation also create a shared organizational culture in terms of language, norms and values and maintain a stable working information flow within organizations.
A study of CEO power, pay structure, and firm performance
Authors: Tien Chengli , Chen Chien-Nan , Chuang Cheng-Min
Published: January 2014

This study has extended existing research on CEO power, pay structure, and firm performance, offering models based mainly on agency theory and managerial power theory, and testing hypotheses using data from 112 companies across a five-year span (2001–2005) in computer-related industry groups in the United States. The results indicated that power from executive directorship positively impacts a firm's return on assets and return on equity, and that CEO power from duality negatively impacts CEO long-term pay and total pay, while CEO power from tenure positively impacts CEO long-term pay and pay leverage, and composite power negatively impacts short-term pay. Evidence for CEO pay as a mediator between CEO power and firm performance revealed that CEO short-term pay positively impacts a firm's return on assets and international performance but negatively impacts its market value, regardless of which source of power is being controlled. CEO total pay positively impacts a firm's return on assets and international performance, with power from CEO duality, directorship, or composite power being controlled. Hence, and in general, CEO pay fails to significantly mediate the relationships between CEO power and firm performance. The contributions include a multiple-perspective study of CEO power, compensation, and firm performance to comprehensively discover each of their respective relationships. This study has further extended the debate over agency perspectives with stewardship perspectives to fill knowledge and theoretical gaps. Thus, evidence-based findings provide boards of directors with practical knowledge for sound governance with another avenue for future research in corporate governance.
Internal resources, local externalities and export performance: An application in the Iberian ham cluster
Authors: Díez-Vial Isabel , Fernández-Olmos Marta
Published: January 2014

This research aims to complement resource-based view with a cluster approach in identifying which elements, both internal to the firm and locally available, improve firms’ export performance. While in the resource-based view exporting firms are contingent upon the development of intangible resources, from a cluster approach exporters exploit local externalities, mainly related to local information, knowledge and resource spillovers. We present empirical evidence from the Iberian ham cluster in Spain, which confirms the relevance of intangibles such as R&D and marketing promotion, but also of cluster linkages with local institutions – technological centres, universities and use of Designation of Origins – in improving export performance. Contrary to expectations, employee education, organizational experience, and information and knowledge-based spillovers from proximate exporters have no significant effect. These findings suggest that an augmented framework may improve the predictive elements of export performance in clusters.
HEALTH AND BODY MASS INDEX CHANGES AMONG ITALIAN CONSCRIPTS BORN IN 1951 AND 1980
Authors: LANARI DONATELLA
Published: January 2014

This paper investigates changes in BMI in the second half of the twentieth century, focusing on two cohorts of Italian conscripts born in 1951 and 1980, and examines how the correlates of high and low BMI have changed over time. Data from conscript cohorts taken from the archives of Italian military districts show that younger conscripts exposed to the rising prevalence of immune-allergological and psychological diseases and metabolic dysfunctions underwent substantial increases in weight. These results are evidenced by quantile regression models, the largest BMI gains being found in diabetic conscripts at the 75th and 90th percentiles.
Effects of a latency period between pre-stimulation and teat cup attachment and periodic vacuum reduction on milking characteristics and teat condition in dairy cows
Authors: Vetter Anna , van Dorland H. Anette , Youssef Mohammed , Bruckmaier Rupert M.
Published: January 2014

The goal of the present study was to examine the suitability of a short pre-stimulation (P) for 15 s followed by a latency period (L) of 30 s before cluster attachment for machine milking. In addition we tested the effect of a periodic reduction of the vacuum under the teat (VR) during the massage phase from 43 kPa to 12–15 kPa on milking characteristics and teat tissue condition. The study was carried out in 9 cows in a cross-over design. Animals were milked twice daily, and each of the 4 treatment combinations was used for six subsequent milkings (P+L vs. continuous P, and standard pulsation vs. VR, respectively). Milk flow was recorded during all experimental milkings. Longitudinal ultrasound cross sections of the teat were performed by B-mode ultrasound after the last milking of each treatment at 0, 5, and 15 min after the end of milking, respectively. None of the evaluated milking characteristics (total milk yield, main milking time, peak flow rate, average milk flow) differed between treatments. Teat measures as obtained by ultrasound cross sections showed no significant difference if individual treatments were compared at the three time points individually. However, teat wall thickness (TWT) tended to be smaller in VR vs. non-VR treatments at 5 min after milking (P=0·05). In conclusion, teat preparation consisting of a short stimulation followed by a latency period represents a similarly efficient pre-stimulation as a continuous pre-stimulation. VR seems to reduce the load on the teat tissue during milking and thus reduces the development of oedema and hence a less pronounced increase of TWT while milking characteristics are similar with or without VR.
Metal mobility and bioaccumulation differences at lower trophic levels in marine ecosystems dominated bySargassumspecies
Authors: Hernández-Almaraz Pablo , Méndez-Rodríguez Lía , Zenteno-Savín Tania , García-Domínguez Federico , Vázquez-Botello Alfonso , Serviere-Zaragoza Elisa
Published: January 2014

Concentrations of cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn) and iron (Fe) were measured in three macroalgal species,Codium simulans,Sargassum sinicolaandGracilaria pachydermatica, and in the sea slugElysia diomedea, living in marine ecosystems dominated bySargassumspecies and located near exploited phosphorite deposits. Metal concentrations in macroalgae and sea slugs were significantly different among sites. The highest concentrations of Cd recorded inC. simulansandS. sinicola, as well as inE. diomedeawere recorded at the site closest to the phosphorite deposit. In general, Cd and Zn concentrations inE. diomedeawere higher than those recorded in specimens ofC. simulans,S. sinicolaandG. pachydermatica. In contrast, Pb, Cu, and Fe concentrations inE. diomedeawere lower than or similar to those in macroalgae from all sampled sites. The information generated contributes to the knowledge about potential mobility and metal bioaccumulation at lower trophic levels in marine eco systems.
Growth, mortality and hatch-date distributions of striped sea bream Lithognathus mormyrus inhabiting the Çanakkale Strait, Turkey
Authors: Ayyildiz Hakan , Ozen Ozcan , Altin Aytac
Published: January 2014

This paper studies age, growth and hatch date distributions of young of the year striped sea bream Lithognathus mormyrus from Canakkale near shores by using a beach seine during September 2006–December 2007. Using otolith microstructure analysis, a total of 416 specimens ranging from 20 to 103 mm LT were aged and found to be between 30 and 307 days old. Average growth rates were estimated to 0.325 mm d−1. The juvenile instantaneous mortality coefficient was found to be 0.0219, which corresponds to a daily mortality of 2.16%. The hatching period of the striped sea bream was determined to occur between April and January, with relatively higher hatching frequency in August.
Emergency Medicine Systems Advancement through Community-based Development
Authors: Bloem Martha M. , Bloem Christina M. , Rosentsveyg Juliana , Arquilla Bonnie
Published: January 2014

Humanitarian health programs frequently focus on immediate relief and are supply side oriented or donor driven. More emphasis should be placed on long-term development projects that engage local community leaders to ensure sustainable change in health care systems. With the Emergency Medicine Educational Exchange (EMEDEX) International Rescue, Recover, Rebuild initiative in Northeast Haiti as a model, this paper discusses the opportunities and challenges in using community-based development to establish emergency medical systems in resource-limited settings.

BloemMM, BloemCM, RosentsveygJ, ArquillaB. Emergency medicine systems advancement through community-based development. Prehosp Disaster Med. 2014;29(1):1-5.
“Them's Fighting Words”: Violence, Masculinity, and the Texas Cowboy in the Late Nineteenth Century
Authors: Moore Jacqueline M.
Published: January 2014

Violence inevitably plays a part in discussions of the cowboy, historical or mythical. Traditionalists celebrated his manly fighting as what tamed the West and saved American manhood; revisionists have castigated the brutality with which he dealt with Native Americans and the environment. It is important, however, to consider what purpose violence served for the cowboy himself. To the working-class cowboy, violence could preserve social harmony, both through defending personal honor and through regulating social behavior of women and minorities. Its use was a clear marker of masculinity, as it allowed him both to show his equal worth with the men around him and to maintain social hierarchies that gave him an advantage over other people. The middle- and upper-class townspeople and cattlemen around cowboys, however, increasingly saw violence as counterproductive. Although parents encouraged aggression in boyhood, they thought that in order to become a real man, one should learn proper restraint and channel that aggression into socially acceptable activities. More and more, respectable ideas of maintaining social order left no room for violence, and consequently cowboys faced increasing social regulation of their masculine self-identities.
Treatment Responses to Tooth Whitening in Twins
Authors: Corby Patricia M. A. , Biesbrock Aaron , Gerlach Robert , Corby Andrea L. , Moreira Alexandre , Schork Nicholas J. , Bretz Walter A.
Published: January 2014

The aim of this study was to determine heritability estimates of treatment responses to a 10% hydrogen peroxide strip-based whitening system in twins. Eighty-five twin pairs were randomly assigned to 10% hydrogen peroxide whitening strips or placebo strips without peroxide. Both twins (monozygotic or dizygotic) received the same treatment. Maxillary teeth were treated for 30 minutes twice daily for 7 days. Efficacy was measured objectively as L* (light–dark), a* (red–green), and b* (yellow–blue) color change from digital images at baseline (∆) and day 8. Heritability estimates for tooth whitening treatment responses for changes from day 8 to baseline were obtained using variance-component methodologies. Whitening treatment responses were highly heritable (h2= 71.0) for ∆b* and ∆a*(p< .0001), but not for ∆L* (h2= 27.0), which was essentially modulated by environmental factors. This study has demonstrated that both genetic and environmental factors significantly contributed to seven-day whitening treatment responses achieved with 10% hydrogen peroxide strips.
Predictive value of the ankle brachial index in patients with acute ischemic stroke
Authors: Tziomalos Konstantinos , Giampatzis Vasilios , Bouziana Stella , Pavlidis Athinodoros , Spanou Marianna , Papadopoulou Maria , Kagelidis Giannis , Boutari Chrysoula , Savopoulos Christos , Hatzitolios Apostolos
Published: January 2014

Background: Peripheral arterial disease (PAD) is frequently present in patients with acute ischemic stroke. However, there are limited data regarding the association between ankle brachial index (ABI) ≤ 0.90 (which is diagnostic of PAD) or > 1.40 (suggesting calcified arteries) and the severity of stroke and in-hospital outcome in this population. We aimed to evaluate these associations in patients with acute ischemic stroke. Patients and methods: We prospectively studied 342 consecutive patients admitted for acute ischemic stroke (37.4 % males, mean age 78.8 ± 6.4 years). The severity of stroke was assessed with the National Institutes of Health Stroke Scale (NIHSS)and the modified Rankin scale (mRS) at admission. The outcome was assessed with the mRS and dependency (mRS 2 - 5) at discharge and in-hospital mortality. Results: An ABI ≤ 0.90 was present in 24.6 % of the patients whereas 68.1 % had ABI 0.91 - 1.40 and 7.3 % had ABI > 1.40. At admission, the NIHSS score did not differ between the 3 groups (10.4 ± 10.6, 8.3 ± 9.3 and 9.3 ± 9.4, respectively). The mRS score was also comparable in the 3 groups (3.6 ± 1.7, 3.1 ± 1.8 and 3.5 ± 2.3, respectively). At discharge, the mRS score did not differ between the 3 groups (2.9 ± 2.2, 2.3 ± 2.1 and 2.7 ± 2.5, respectively) and dependency rates were also comparable (59.5, 47.6 and 53.3 %, respectively). In-hospital mortality was almost two-times higher in patients with ABI ≤ 0.90 than in patients with ABI 0.91 - 1.40 or > 1.40 but this difference was not significant (10.9, 6.6 and 6.3 %, respectively). Conclusions: An ABI ≤ 0.90 or > 1.40 does not appear to be associated with more severe stroke or worse in-hospital outcome in patients with acute ischemic stroke.
Die Dokumentation der Entwicklung von 2- und 3-jährigen Kindern in Tageseinrichtungen
Authors: Straßburg Hans Michael , Mäder Britta , Sporrer Tobias
Published: January 2014

Es werden Daten zur Entwicklung von 99 Kindern zwischen 13 und 36 Monaten, die in deutschen Kindertagesstätten betreut wurden, für die Bereiche Motorik, Sprache, Spielverhalten sowie Verhalten bei der Nahrungsaufnahme und der Sauberkeitsentwicklung vorgestellt. Die Erhebung beruht auf dem Konzept des Pikler-Instituts in Budapest/Ungarn, mit dem die Entwicklung von mehreren tausend Kindern dokumentiert wurde. In den vorläufigen Schlussfolgerungen werden die aktuellen Diskussionen zur Tagesbetreuung von Kleinkindern berücksichtigt.
Bildung in der Familie und elterliche Betreuungsbedarfe als neue Themen des Monitorings frühkindlicher Bildung
Authors: Grgic Mariana , Alt Christian
Published: January 2014

Das Monitoring frühkindlicher Bildung im Rahmen der Nationalen Bildungsberichterstattung sowie der Evaluation des Kinderförderungsgesetzes (KiföG) hat in den letzten Jahren seine Perspektive zunehmend von der Beobachtung des Systems der frühkindlichen Bildung mit Hilfe von etablierten Indikatoren auf die Beobachtung von Bildungsprozessen in der Familie sowie der elterlichen Betreuungsbedarfe erweitert. Diese Themen haben eine große Relevanz für die kindliche Bildungsbiografie sowie die Planung des weiteren U3-Ausbaus. Elternbefragungen, die neben der Angebotsperspektive die kindliche Förderung in der Familie, deren Orientierungen und Sichtweisen beinhalten, ergänzen somit die Informationen aus der amtlichen Statistik. Die Ergebnisse der Elternbefragungen des Deutschen Jugendinstituts (AID:A, KiföG) zeigen, dass die kindliche Förderung stark von der elterlichen Bildung und den Erziehungsmilieus abhängt, in denen Kinder aufwachsen. Bildungsorientierte Eltern fördern ihre Kinder selbst häufiger, wünschen sich für ihr unter 3-jähriges Kind häufiger die Teilnahme an frühkindlicher Bildung und können dies – vor dem Hintergrund eines derzeit nicht bedarfsdeckenden Angebots – auch häufiger realisieren. Bereits in der frühen Kindheit werden somit Mechanismen sozialer Ungleichheit in der Teilnahme an frühkindlicher Bildung sichtbar, die in Zusammenhang mit dem weiteren U3-Ausbau weiterhin beobachtet werden müssen.
Importance of soil organic matter for the diversity of microorganisms involved in the degradation of organic pollutants
Authors: Neumann Dominik , Heuer Anke , Hemkemeyer Michael , Martens Rainer , Tebbe Christoph C
Published: January 2014

Many organic pollutants are readily degradable by microorganisms in soil, but the importance of soil organic matter for their transformation by specific microbial taxa is unknown. In this study, sorption and microbial degradation of phenol and 2,4-dichlorophenol (DCP) were characterized in three soil variants, generated by different long-term fertilization regimes. Compared with a non-fertilized control (NIL), a mineral-fertilized NPK variant showed 19% and a farmyard manure treated FYM variant 46% more soil organic carbon (SOC). Phenol sorption declined with overall increasing SOC because of altered affinities to the clay fraction (soil particles <2 mm in diameter). In contrast, DCP sorption correlated positively with particulate soil organic matter (present in the soil particle fractions of 63–2000 μm). Stable isotope probing identified Rhodococcus, Arthrobacter (both Actinobacteria) and Cryptococcus (Basidiomycota) as the main degraders of phenol. Rhodococcus and Cryptococcus were not affected by SOC, but the participation of Arthrobacter declined in NPK and even more in FYM. 14C-DCP was hardly metabolized in the NIL variant, more efficiently in FYM and most in NPK. In NPK, Burkholderia was the main degrader and in FYM Variovorax. This study demonstrates a strong effect of SOC on the partitioning of organic pollutants to soil particle size fractions and indicates the profound consequences that this process could have for the diversity of bacteria involved in their degradation.
Humboldt’s spa: microbial diversity is controlled by temperature in geothermal environments
Authors: Sharp Christine E , Brady Allyson L , Sharp Glen H , Grasby Stephen E , Stott Matthew B , Dunfield Peter F
Published: January 2014

Over 200 years ago Alexander von Humboldt (1808) observed that plant and animal diversity peaks at tropical latitudes and decreases toward the poles, a trend he attributed to more favorable temperatures in the tropics. Studies to date suggest that this temperature–diversity gradient is weak or nonexistent for Bacteria and Archaea. To test the impacts of temperature as well as pH on bacterial and archaeal diversity, we performed pyrotag sequencing of 16S rRNA genes retrieved from 165 soil, sediment and biomat samples of 36 geothermal areas in Canada and New Zealand, covering a temperature range of 7.5–99 °C and a pH range of 1.8–9.0. This represents the widest ranges of temperature and pH yet examined in a single microbial diversity study. Species richness and diversity indices were strongly correlated to temperature, with R2 values up to 0.62 for neutral–alkaline springs. The distributions were unimodal, with peak diversity at 24 °C and decreasing diversity at higher and lower temperature extremes. There was also a significant pH effect on diversity; however, in contrast to previous studies of soil microbial diversity, pH explained less of the variability (13–20%) than temperature in the geothermal samples. No correlation was observed between diversity values and latitude from the equator, and we therefore infer a direct temperature effect in our data set. These results demonstrate that temperature exerts a strong control on microbial diversity when considered over most of the temperature range within which life is possible.
The role of quorum sensing signalling in EPS production and the assembly of a sludge community into aerobic granules
Authors: Tan Chuan Hao , Koh Kai Shyang , Xie Chao , Tay Martin , Zhou Yan , Williams Rohan , Ng Wun Jern , Rice Scott A , Kjelleberg Staffan
Published: January 2014

Quorum sensing (QS) signalling has been extensively studied in single species populations. However, the ecological role of QS in complex, multi-species communities, particularly in the context of community assembly, has neither been experimentally explored nor theoretically addressed. Here, we performed a long-term bioreactor ecology study to address the links between QS, organization and composition of complex microbial communities. The conversion of floccular biomass to highly structured granules was found to be non-random, but strongly and positively correlated with N-acyl-homoserine-lactone (AHL)-mediated QS. Specific AHLs were elevated up to 100-fold and were strongly associated with the initiation of granulation. Similarly, the levels of particular AHLs decreased markedly during the granular disintegration phase. Metadata analysis indicated that granulation was accompanied by changes in extracellular polymeric substance (EPS) production and AHL add-back studies also resulted in increased EPS synthesis. In contrast to the commonly reported nanomolar to micromolar signal concentrations in pure culture laboratory systems, QS signalling in the granulation ecosystem occurred at picomolar to nanomolar concentrations of AHLs. Given that low concentrations of AHLs quantified in this study were sufficient to activate AHL bioreporters in situ in complex granular communities, AHL mediated QS may be a common feature in many natural and engineered ecosystems, where it coordinates community behaviour.
Deep-sea hydrothermal ventEpsilonproteobacteriaencode a conserved and widespread nitrate reduction pathway (Nap)
Authors: Vetriani Costantino , Voordeckers James W , Crespo-Medina Melitza , O’Brien Charles E , Giovannelli Donato , Lutz Richard A
Published: January 2014

Despite the frequent isolation of nitrate-respiring Epsilonproteobacteria from deep-sea hydrothermal vents, the genes coding for the nitrate reduction pathway in these organisms have not been investigated in depth. In this study we have shown that the gene cluster coding for the periplasmic nitrate reductase complex (nap) is highly conserved in chemolithoautotrophic, nitrate-reducing Epsilonproteobacteria from deep-sea hydrothermal vents. Furthermore, we have shown that the napA gene is expressed in pure cultures of vent Epsilonproteobacteria and it is highly conserved in microbial communities collected from deep-sea vents characterized by different temperature and redox regimes. The diversity of nitrate-reducing Epsilonproteobacteria was found to be higher in moderate temperature, diffuse flow vents than in high temperature black smokers or in low temperatures, substrate-associated communities. As NapA has a high affinity for nitrate compared with the membrane-bound enzyme, its occurrence in vent Epsilonproteobacteria may represent an adaptation of these organisms to the low nitrate concentrations typically found in vent fluids. Taken together, our findings indicate that nitrate reduction is widespread in vent Epsilonproteobacteria and provide insight on alternative energy metabolism in vent microorganisms. The occurrence of the nap cluster in vent, commensal and pathogenic Epsilonproteobacteria suggests that the ability of these bacteria to respire nitrate is important in habitats as different as the deep-sea vents and the human body.
Microorganisms persist at record depths in the subseafloor of the Canterbury Basin
Authors: Ciobanu Maria-Cristina , Burgaud Gaëtan , Dufresne Alexis , Breuker Anja , Rédou Vanessa , Ben Maamar Sarah , Gaboyer Frédéric , Vandenabeele-Trambouze Odile , Lipp Julius Sebastian , Schippers Axel , Vandenkoornhuyse Philippe , Barbier Georges , Jebbar Mohamed , Godfroy Anne , Alain Karine
Published: January 2014

The subsurface realm is colonized by microbial communities to depths of >1000 meters below the seafloor (m.b.sf.), but little is known about overall diversity and microbial distribution patterns at the most profound depths. Here we show that not only Bacteria and Archaea but also Eukarya occur at record depths in the subseafloor of the Canterbury Basin. Shifts in microbial community composition along a core of nearly 2 km reflect vertical taxa zonation influenced by sediment depth. Representatives of some microbial taxa were also cultivated using methods mimicking in situ conditions. These results suggest that diverse microorganisms persist down to 1922 m.b.sf. in the seafloor of the Canterbury Basin and extend the previously known depth limits of microbial evidence (i) from 159 to 1740 m.b.sf. for Eukarya and (ii) from 518 to 1922 m.b.sf. for Bacteria.
Fast preparation of a hydrophobic monolith by redox initiation and its application in the separation of small molecules
Authors: Hao Mengbei , Zhong Jing , Li Ruo , Li Haijing , Bai Ligai , Yang Gengliang
Published: January 2014

A novel skeleton hydrophobic polymeric monolith was prepared by redox initiation and used to separate a mixture of benzenes.
Method validation and occurrence of dioxins and furans (PCDD/Fs) in fish from Brazil
Authors: Augusti Daniella Vasconcellos , Magalhães Elisângela Jaqueline , Nunes Carolina Mariana , Vieira dos Santos Eleonora , Dardot Prates Ravi Govinda , Pissinatti Rafael
Published: January 2014

An isotope dilution method, validated in accordance with specific requirements defined by the European Commission, for quantification of 17 polychlorinated dioxins and furans in fish from Brazil is described.
Determination of three curcuminoids in Curcuma longa by microemulsion electrokinetic chromatography with protective effects on the analytes
Authors: Li Feng , Liu Rui , Yang Fengqing , Xiao Wen , Chen Cheng , Xia Zhining
Published: January 2014

A microemulsion electrokinetic chromatography (MEEKC) method was developed for the simultaneous determination of three curcuminoids to avoid their alkaline degradation during capillary electrophoresis (CE) analysis with alkaline buffers.
Phototriggered formation and disappearance of surface-confined self-assembly composed of photochromic 2-thienyl-type diarylethene: a cooperative model at the liquid/solid interface
Authors: Yokoyama Soichi , Hirose Takashi , Matsuda Kenji
Published: January 2014

A photoresponsive self-assembly on a 2-D surface was investigated by STM and the behavior was analyzed by a cooperative model.
Trigonal bipyramidal 5d–4f molecules with SMM behavior
Authors: Saber Mohamed R. , Dunbar Kim R.
Published: January 2014

A family of trigonal bipyramidal (TBP) 5d–4f cyanide bridged aggregates have been synthesized that exhibit slow relaxation of the magnetization below 4 K as indicated by a signal in the out-of-phase ac susceptibility data under zero field.
Synthesis and high-throughput testing of multilayered supported ionic liquid catalysts for the conversion of CO2 and epoxides into cyclic carbonates
Authors: Agrigento Paola , Al-Amsyar Syed M. , Sorée Benjamin , Taherimehr Masoumeh , Gruttadauria Michelangelo , Aprile Carmela , Pescarmona Paolo P.
Published: January 2014

Multilayered covalently supported ionic liquid catalysts achieve excellent TON and productivity in the reaction of CO2 with various epoxides to produce cyclic carbonates.
The role of the CO adsorption on Pt monolayers supported on flat and stepped Au surfaces: a density functional investigation
Authors: Tereshchuk Polina , Freire Rafael L. H. , Da Silva Juarez L. F.
Published: January 2014

Ultrathin metal films supported on transition-metal surfaces have been considered as promising catalysts as their chemical activity can be controlled by substrate strain, composition, and ligand effects, however, our atomistic understanding of the atomic structure of those systems is far from satisfactory.
Preparation of low-crystalline POSS containing two types of alkylammonium groups and its optically transparent film
Authors: Tokunaga Takahiro , Shoiriki Miki , Mizumo Tomonobu , Kaneko Yoshiro
Published: January 2014

A low-crystalline POSS containing two types of alkylammonium groups was successfully prepared by hydrolytic condensation of two types of amino group-containing organotrialkoxysilanes,i.e.AEAPTMOS and APTMOS, using aqueous CF3SO3H, forming an optically transparent film.
Circulating miRNA profiles provide a biomarker for severity of stroke outcomes associated with age and sex in a rat model
Authors: Selvamani Amutha , Williams Madison H. , Miranda Rajesh C. , Sohrabji Farida
Published: January 2014

Small non-coding RNA [miRNA (microRNA)] found in the circulation have been used successfully as biomarkers and mechanistic targets for chronic and acute disease. The present study investigated the impact of age and sex on miRNA expression following ischaemic stroke in an animal model. Adult (6 month) and middle-aged (11–12 months) female and male rats were subject to MCAo (middle cerebral artery occlusion) using ET-1 (endothelin-1). Circulating miRNAs were analysed in blood samples at 2 and 5 days post-stroke, and brain miRNAs were analysed at 5 days post-stroke. Although stroke-associated infarction was observed in all groups, infarct volume and sensory-motor deficits were significantly reduced in adult females compared with middle-aged females, adult males or middle-aged males. At 2 days post-stroke, 21 circulating miRNAs were differentially regulated and PCA (principal component analysis) confirmed that most of the variance was due to age. At 5 days post-stroke, 78 circulating miRNAs exhibited significantly different regulation, and most of the variance was associated with sex. A small cohort (five) of miRNAs, miR-15a, miR-19b, miR-32 miR-136 and miR-199a-3p, were found to be highly expressed exclusively in adult females compared with middle-aged females, adult males and middle-aged males. Predicted gene targets for these five miRNAs analysed for KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways revealed that the top ten KEGG pathways were related to growth factor signalling, cell structure and PI3K (phosphoinositide 3-kinase)/Akt and mTOR (mammalian target of rapamycin) signalling. Overall, the pattern of circulating miRNA expression suggests an early influence of age in stroke pathology, with a later emergence of sex as a factor for stroke severity.
The transition probability and the probability for the left-most particle's position of the q-totally asymmetric zero range process
Authors: Korhonen Marko , Lee Eunghyun
Published: January 2014

We treat the N-particle zero range process whose jumping rates satisfy a certain condition. This condition is required to use the Bethe ansatz and the resulting model is the q-boson model by Sasamoto and Wadati [“Exact results for one-dimensional totally asymmetric diffusion models,” J. Phys. A 31, 6057–6071 (1998)] or the q-totally asymmetric zero range process (TAZRP) by Borodin and Corwin [“Macdonald processes,” Probab. Theory Relat. Fields (to be published)]. We find the explicit formula of the transition probability of the q-TAZRP via the Bethe ansatz. By using the transition probability we find the probability distribution of the left-most particle's position at time t. To find the probability for the left-most particle's position we find a new identity corresponding to identity for the asymmetric simple exclusion process by Tracy and Widom [“Integral formulas for the asymmetric simple exclusion process,” Commun. Math. Phys. 279, 815–844 (2008)]. For the initial state that all particles occupy a single site, the probability distribution of the left-most particle's position at time t is represented by the contour integral of a determinant.
Kinetic modeling of particle dynamics in H− negative ion sources (invited)
Authors: Hatayama A. , Shibata T. , Nishioka S. , Ohta M. , Yasumoto M. , Nishida K. , Yamamoto T. , Miyamoto K. , Fukano A. , Mizuno T.
Published: January 2014

Progress in the kinetic modeling of particle dynamics in H− negative ion source plasmas and their comparisons with experiments are reviewed, and discussed with some new results. Main focus is placed on the following two topics, which are important for the research and development of large negative ion sources and high power H− ion beams: (i) Effects of non-equilibrium features of EEDF (electron energy distribution function) on H− production, and (ii) extraction physics of H− ions and beam optics.
Preparation of a primary argon beam for the CERN fixed target physics
Authors: Küchler D. , O’Neil M. , Scrivens R. , Thomae R.
Published: January 2014

The fixed target experiment NA61 in the North Area of the Super Proton Synchrotron is studying phase transitions in strongly interacting matter. Up to now they used the primary beams available from the CERN accelerator complex (protons and lead ions) or fragmented beams created from the primary lead ion beam. To explore a wider range of energies and densities a request was made to provide primary argon and xenon beams. This paper describes the results of the setting up and 10 week test run of the Ar11+ beam from the 14.5 GHz ECR ion source and the linear accelerator (Linac3) at CERN.
Fluorescence excitation and ultraviolet absorption spectra and theoretical calculations for benzocyclobutane: Vibrations and structure of its excited S1(π,π*) electronic state
Authors: Shin Hee Won , Ocola Esther J. , Kim Sunghwan , Laane Jaan
Published: January 2014

The fluorescence excitation spectra of jet-cooled benzocyclobutane have been recorded and together with its ultraviolet absorption spectra have been used to assign the vibrational frequencies for this molecule in its S1(π,π*) electronic excited state. Theoretical calculations at the CASSCF(6,6)/aug-cc-pVTZ level of theory were carried out to compute the structure of the molecule in its excited state. The calculated structure was compared to that of the molecule in its electronic ground state as well as to the structures of related molecules in their S0 and S1(π,π*) electronic states. In each case the decreased π bonding in the electronic excited states results in longer carbon-carbon bonds in the benzene ring. The skeletal vibrational frequencies in the electronic excited state were readily assigned and these were compared to the ground state and to the frequencies of five similar molecules. The vibrational levels in both S0 and S1(π,π*) states were remarkably harmonic in contrast to the other bicyclic molecules. The decreases in the frequencies of the out-of-plane skeletal modes reflect the increased floppiness of these bicyclic molecules in their S1(π,π*) excited state.
Wave function for harmonically confined electrons in time-dependent electric and magnetostatic fields
Authors: Zhu Hong-Ming , Chen Jin-Wang , Pan Xiao-Yin , Sahni Viraht
Published: January 2014

We derive via the interaction “representation” the many-body wave function for harmonically confined electrons in the presence of a magnetostatic field and perturbed by a spatially homogeneous time-dependent electric field—the Generalized Kohn Theorem (GKT) wave function. In the absence of the harmonic confinement – the uniform electron gas – the GKT wave function reduces to the Kohn Theorem wave function. Without the magnetostatic field, the GKT wave function is the Harmonic Potential Theorem wave function. We further prove the validity of the connection between the GKT wave function derived and the system in an accelerated frame of reference. Finally, we provide examples of the application of the GKT wave function.
The influence of a presence of a heavy atom on the spin-spin coupling constants between two light nuclei in organometallic compounds and halogen derivatives
Authors: Wodyński Artur , Pecul Magdalena
Published: January 2014

The 1JCC and 1JCH spin-spin coupling constants have been calculated by means of density functional theory (DFT) for a set of derivatives of aliphatic hydrocarbons substituted with I, At, Cd, and Hg in order to evaluate the substituent and relativistic effects for these properties. The main goal was to estimate HALA (heavy-atom-on-light-atom) effects on spin-spin coupling constants and to explore the factors which may influence the HALA effect on these properties, including the nature of the heavy atom substituent and carbon hybridization. The methods applied range, in order of reduced complexity, from Dirac-Kohn-Sham method (density functional theory with four-component Dirac-Coulomb Hamiltonian), through DFT with two- and one-component Zeroth Order Regular Approximation (ZORA) Hamiltonians, to scalar non-relativistic effective core potentials with the non-relativistic Hamiltonian. Thus, we are able to compare the performance of ZORA-DFT and Dirac-Kohn-Sham methods for modelling of the HALA effects on the spin-spin coupling constants.
Chemical stability of molten 2,4,6-trinitrotoluene at high pressure
Authors: Dattelbaum Dana M. , Chellappa Raja S. , Bowden Patrick R. , Coe Joshua D. , Margevicius Madeline A.
Published: January 2014

2,4,6-trinitrotoluene (TNT) is a molecular explosive that exhibits chemical stability in the molten phase at ambient pressure. A combination of visual, spectroscopic, and structural (x-ray diffraction) methods coupled to high pressure, resistively heated diamond anvil cells was used to determine the melt and decomposition boundaries to >15 GPa. The chemical stability of molten TNT was found to be limited, existing in a small domain of pressure-temperature conditions below 2 GPa. Decomposition dominates the phase diagram at high temperatures beyond 6 GPa. From the calculated bulk temperature rise, we conclude that it is unlikely that TNT melts on its principal Hugoniot.
Experimental and numerical characterization of the sound pressure in standing wave acoustic levitators
Authors: Stindt A. , Andrade M. A. B. , Albrecht M. , Adamowski J. C. , Panne U. , Riedel J.
Published: January 2014

A novel method for predictions of the sound pressure distribution in acoustic levitators is based on a matrix representation of the Rayleigh integral. This method allows for a fast calculation of the acoustic field within the resonator. To make sure that the underlying assumptions and simplifications are justified, this approach was tested by a direct comparison to experimental data. The experimental sound pressure distributions were recorded by high spatially resolved frequency selective microphone scanning. To emphasize the general applicability of the two approaches, the comparative studies were conducted for four different resonator geometries. In all cases, the results show an excellent agreement, demonstrating the accuracy of the matrix method.
Statistical analysis of variations in impurity ion heating at reconnection events in the Madison Symmetric Torus
Authors: Cartolano M. S. , Craig D. , Den Hartog D. J. , Kumar S. T. A. , Nornberg M. D.
Published: January 2014

The connection between impurity ion heating and other physical processes in the plasma is evaluated by studying variations in the amount of ion heating at reconnection events in the Madison Symmetric Torus (MST). Correlation of the change in ion temperature with individual tearing mode amplitudes indicates that the edge-resonant modes are better predictors for the amount of global ion heating than the core-resonant modes. There is also a strong correlation between ion heating and current profile relaxation. Simultaneous measurements of the ion temperature at different toroidal locations reveal, for the first time, a toroidal asymmetry to the ion heating in MST. These results present challenges for existing heating theories and suggest a stronger connection between edge-resonant tearing modes, current profile relaxation, and ion heating than has been previously thought.
A rugged, high precision capacitance diaphragm low pressure gauge for cryogenic use
Authors: Lago Leatitia , Herbeaux Christian , Bol Marc , Roy Pascale , Manceron Laurent
Published: January 2014

In order to carry out precise laboratory measurements of infrared absorption intensities, line profiles of molecules and organic volatile compounds for atmospheric chemistry in planetary and upper earth atmospheric layers, precise gas pressure measurement between 10−3 and a few mbars in the 77–300 K temperature range is necessary. A prototype, rugged, precision capacitive pressure gauge for cryogenic use has been designed, built at SOLEIL and tested down to 77 K. The design includes corrosion-resistant materials and has been tailored to operate on a differential measurement scheme based on a simple, precision capacitance-to-digital converter chip, instead of high precision floating capacitive bridges, as are used in other designs. The designs conception and performance specifications are presented here, illustrated by a precision of better than 1% in the 0.2–40 mbar range, with a resolution of 2 × 10−3 mbar. The gauge is tunable and can be adjusted for higher precision and a better resolution, at the expense of the maximum high-pressure range.
First negative ion beam measurement by the Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE)
Authors: Serianni G. , De Muri M. , Muraro A. , Veltri P. , Bonomo F. , Chitarin G. , Pasqualotto R. , Pavei M. , Rizzolo A. , Valente M. , Franzen P. , Ruf B. , Schiesko L.
Published: January 2014

The Source for Production of Ion of Deuterium Extracted from Rf plasma (SPIDER) test facility is under construction in Padova to optimise the operation of the beam source of ITER neutral beam injectors. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon-fibre-carbon-composite tiles. A small-scale version of the entire system has been employed in the BAvarian Test MAchine for Negative ions (BATMAN) testbed by arranging two prototype tiles in the vertical direction. The paper presents a description of the mini-STRIKE system and of the data analysis procedures, as well as some results concerning the BATMAN beam under varying operating conditions.
Formation of regularly arranged large grain silicon islands by using embedded micro mirrors in the flash crystallization of amorphous silicon
Authors: Henke Thomas , Bartha Johann W. , Rebohle Lars , Merkel Ulrich , Hübner René , Albert Matthias , Skorupa Wolfgang
Published: January 2014

The well-controlled formation of large silicon grains on predetermined positions is a key issue in order to produce single-grain thin film transistors on insulating substrates and thus to enable monolithic 3D integration. One way to achieve this is to artificially control the solidification of molten silicon during the flash crystallization of amorphous silicon. In this work, we present such an approach in which we used patterned metal layers below the amorphous silicon. The metal spots act as embedded micro mirrors and consequently introduce a lateral temperature gradient into the silicon film during flash crystallization. As a result, the grain growth from molten silicon is seeded from the predefined regions with the lowest temperature and thus the formation of large crystal silicon islands proceeds in a controlled manner. In the scope of this study, we evaluated a variety of different mirror patterns with respect to their suitability for this approach and observed that patterns of both circular and line-shaped mirrors are the most promising variants. The resulting silicon islands have pillow-like shapes and are located exclusively in regions between neighboring mirrors. They exhibit dimensions of a few tens of micrometers and consist of grains with sizes up to 28 μm. The formation of single-grain silicon pillow-like structures was observed for particular mirror patterns having circular mirrors. On the other hand, the application of mirror patterns with line-shaped mirrors resulted in the formation of elongated silicon grains which we explained in terms of lateral solidification starting from one edge. Furthermore, this approach exhibits grain filter characteristics leading to the controlled growth of large single grains at predetermined positions.
Interaction of light with the ZnO surface: Photon induced oxygen “breathing,” oxygen vacancies, persistent photoconductivity, and persistent photovoltage
Authors: Gurwitz Ron , Cohen Rotem , Shalish Ilan
Published: January 2014

ZnO surfaces adsorb oxygen in the dark and emit CO2 when exposed to white light, reminiscent of the lungs of living creatures. We find that this exchange of oxygen with the ambient affects the integrity of the ZnO surface. Thus, it forms a basis for several interesting surface phenomena in ZnO, such as photoconductivity, photovoltage, and gas sensing, and has a role in ZnO electrical conduction. Using x-ray photoelectron spectroscopy on ZnO nanowires, we observed a decomposition of ZnO under white light and formation of oxygen-depleted surface, which explains photoconductivity by the electron donation of oxygen vacancies. Our findings suggest that the observed decomposition of the ZnO lattice may only take place due to photon-induced reduction of ZnO by carbon containing molecules (or carbo-photonic reduction), possibly from the ambient gas, accounting in a consistent way for both the reduced demands on the energy required for decomposition and for the observed emission of lattice oxygen in the form of CO2. The formation of oxygen-vacancy rich surface is suggested to induce surface delta doping, causing accumulation of electrons at the surface, which accounts for both the increase in conductivity and the flattening of the energy bands. Using surface photovoltage spectroscopy in ultra high vacuum, we monitored changes in the deep level spectrum. We observe a wide optical transition from a deep acceptor to the conduction band, which energy position coincides with the position of the so called “green luminescence” in ZnO. This green transition disappears with the formation of surface oxygen vacancies. Since the oxygen vacancies are donors, while the green transition involves surface acceptors, the results suggest that the initial emission of oxygen originates at the defect sites of the latter, thereby eliminating each other. This suggests that the green transition originates at surface Zn vacancy acceptors. Removing an oxygen atom from a Zn vacancy completes the vacancy to become a full ZnO molecule vacancy, which does not produce deep levels. Our results explain why ZnO finds use as an electrical detector for oxygen and for carbon containing gas molecules. They may also shed new light on photocatalytic uses of ZnO. It is suggested that similar surface phenomena may affect other semiconducting oxides.
Complexation of n SO2 molecules (n = 1, 2, 3) with formaldehyde and thioformaldehyde
Authors: Azofra Luis Miguel , Scheiner Steve
Published: January 2014

Ab initio and density functional theory calculations are used to examine complexes formed between H2CO and H2CS with 1, 2, and 3 molecules of SO2. The nature of the interactions is probed by a variety of means, including electrostatic potentials, natural bond orbital, atoms in molecules, energy decomposition, and electron density redistribution maps. The dimers are relatively strongly bound, with interaction energies exceeding 5 kcal/mol. The structures are cyclic, containing both a O/S⋯S chalcogen bond and a CH⋯O H-bond. Addition of a second SO2 molecule leads to a variety of heterotrimer structures, most of which resemble the original dimer, where the second SO2 molecule engages in a chalcogen bond with the first SO2, and a C⋯O attraction with the H2CX. Some cooperativity is apparent in the trimers and tetramers, with an attractive three-body interaction energy and shortened intermolecular distances.