bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Relational and Team Characteristics on Individual Performance: A Social Network Perspective
Authors: Carboni Inga , Ehrlich Kate 
Published: July 2013

AbstractIncreasingly, researchers in human resource management are recognizing the impact of relational characteristics of work design on performance outcomes. In particular, complex task interdependencies associated with loosely structured teams call for an approach to work design that incorporates interpersonal relationships and informal communication to help individuals adapt to changing demands. Taking a social network perspective, we propose that position in the structure of informal communication networks shapes the opportunities and constraints to action for individuals and determines their informal roles. We present a multilevel model in which the relationship between position within a social structure and individual performance was examined within the context of team performance and team tenure. Hypotheses were tested using network data collected from nearly 300 employees in 30 sales teams. Results indicated that individuals close to the core of a team outperformed more peripheral individuals, but only to the extent that teams were high‐performing or had been together longer as a team. The article concludes with a general discussion of the implications for HR theory and practices targeted at improving individual performance outcomes.
Psychological Contracts and Informal Networks in Organizations: The Effects of Social Status and Local Ties
Authors: Dabos Guillermo E. , Rousseau Denise M. 
Published: July 2013

AbstractInformal social networks in organizations shape how employees understand their employment relationship. Networks can aid or undercut HR efforts to promote psychological contracts that benefit both employees and the employer. Data collected from 96 university faculty members demonstrate that network influence from both social status in the organization's larger informal structure and local ties with socially proximate colleagues shape psychological contract beliefs. Specific effects, however, vary by type of contract term. When contract terms involve resources employees compete for (e.g., opportunities for career advancement), effects are found for social status, such that those who are better positioned in the advice network hold more positive beliefs regarding the extent of the employer commitment. When contract terms involve noncompetitive resources broadly available to all employees (e.g., concern for employee well‐being), network effects reveal comparable beliefs between those who share a direct friendship tie (cohesion) or the same friends in common with other faculty members (structural equivalence). Implications for research and HR practice are discussed.
Developing Organizational Social Capital or Prima Donnas in MNEs? The Role of Global Leadership Development Programs
Authors: Espedal Bjarne , Gooderham Paul N. , Stensaker Inger G. 
Published: July 2013

AbstractThe aim of this article is to identify those aspects of global leadership development (GLD) programs that promote social capital and knowledge sharing in multinational enterprises (MNEs). The analysis is conducted within the context of two Scandinavian MNEs. Both MNEs had aimed at the development of inter‐unit social networks and knowledge sharing. In the one program, participants bonded with other participants while remaining socially embedded in their business units of origin. As a consequence, bridging social capital was developed, and knowledge sharing across the MNE increased. For the other program, despite apparent similarities in design and goals, we found the reverse. In addition to differences in the selection mechanisms employed by the two programs, our research identified contrasting modes of organizing the in‐program learning processes and dissimilarities in the roles played by top management and GLD consultants during the programs. Overall, while the one program was congruent with the Scandinavian corporate culture context, the other was at odds with it, and instead of developing social capital it turned out prima donnas. We argue that MNEs aiming to use GLD programs for developing social capital across their operations must be highly sensitive to the issue of congruence with the established corporate culture.
In vitro and in vivo evaluation of chitosan/β‐glycerol phosphate composite membrane for guided bone regeneration
Authors: Cui Jun , Liang Jie , Wen Yong , Sun Xiaoning , Li Tiejun , Zhang Gairong , Sun Kangning , Xu Xin 
Published: July 2013

AbstractChitosan and β‐glycerol phosphate (CS/β‐GP) composite, with a thermosensitive sol–gel transition behavior, has been tested as one of the viable materials for barrier membrane fabrication. These studies have provided us with a new concept for a guided bone regeneration (GBR) membrane design. The composition, porous structure of the membrane, and the neutral mild preparation procedures make the CS/β‐GP membrane a potentially active guide for bone regeneration. In this study, the CS/β‐GP composite membrane, with different concentrations of β‐GP, was studied to assess their potential utility in GBR application. The initial attachment of the ST2 stromal cell line to the CS/β‐GP composite membrane was better than their attachment to the pure CS membrane. The proliferation and osteoblastic differentiation of the cells were much higher on the CS/β‐GP composite membrane as compared to the pure CS membrane (p < 0.05). A mild inflammatory response was observed around the implanted CS/β‐GP composite membrane without any foreign body reaction that continued up to 4 weeks of postsurgery. This primary study indicated that the in vitro and in vivo bioactivities of the CS/β‐GP composite membrane fulfilled the requirements for GBR technique. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2911–2917, 2014.
Trabecular titanium can inducein vitroosteogenic differentiation of human adipose derived stem cells without osteogenic factors
Authors: Benazzo Francesco , Botta Laura , Scaffino Manuela Federica , Caliogna Laura , Marullo Matteo , Fusi Simonetta , Gastaldi Giulia 
Published: July 2013

AbstractTrabecular Titanium (TT) is an innovative highly porous structure that imitates the morphology of trabecular bone with good mechanical properties. Adipose‐derived stem cells are a multipotent cell population that can be used in regenerative medicine, in particular, for bone therapeutic applications. The ability of TT to induce the osteogenic differentiation of human adipose derived stem cells (hASCs) in the absence of osteogenic factors was evaluated using molecular biological, biochemical, and immunohistochemical methods. At 7 and 21 days from differentiation, the hASCs grown on TT scaffolds showed similar expressions of alkaline phosphatase (ALP) and Runx‐2 both in the presence and in the absence of osteogenic factors, as well as at transcript and protein levels. hASCs cultured on monolayer in the presence of the medium obtained from the wells where hASCs/scaffold constructs were cultured in the absence of osteogenic factors differentiated towards the osteogenic phenotype: their gene and protein expression of ALP and Runx‐2 was similar to that of the same cells cultured in the presence of osteogenic factors, and significantly higher than that of the ones cultured in growth medium. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2061–2071, 2014.
Biocompatibility of a porous alumina ceramic scaffold coated with hydroxyapatite and bioglass
Authors: Kido Hueliton Wilian , Ribeiro Daniel Araki , de Oliveira Poliani , Parizotto Nivaldo Antônio , Camilo Claudia Cristiane , Fortulan Carlos Alberto , Marcantonio Elcio , da Silva Victor Hugo Pereira , Muniz Renno Ana Claudia 
Published: July 2013

AbstractThis study aimed to evaluate the osteointegration and genotoxic potential of a bioactive scaffold, composed of alumina and coated with hydroxyapatite and bioglass, after their implantation in tibias of rats. For this purpose, Wistar rats underwent surgery to induce a tibial bone defect, which was filled with the bioactive scaffolds. Histology analysis (descriptive and morphometry) of the bone tissue and the single‐cell gel assay (comet) in multiple organs (blood, liver, and kidney) were used to reach this aim after a period of 30, 60, 90, and 180 days of material implantation. The main findings showed that the incorporation of hydroxyapatite and bioglass in the alumina scaffolds produced a suitable environment for bone ingrowth in the tibial defects and did not demonstrate any genotoxicity in the organs evaluated in all experimental periods. These results clearly indicate that the bioactive scaffolds used in this study present osteogenic potential and still exhibit local and systemic biocompatibility. These findings are promising once they convey important information about the behavior of this novel biomaterial in biological system and highlight its possible clinical application. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2072–2078, 2014.
The stimulation of osteogenic differentiation of mesenchymal stem cells and vascular endothelial growth factor secretion of endothelial cells by β‐CaSiO3/β‐Ca3(PO4)2 scaffolds
Authors: Wang Chen , Lin Kaili , Chang Jiang , Sun Jiao 
Published: July 2013

AbstractPorous β‐CaSiO3/β‐Ca3(PO4)2 (β‐CS/β‐TCP) composite scaffolds have been previously shown to promote bone formation in vivo. However, the mechanisms underlying such beneficial effects remain unclear. In this study, we recreated an extracellular environment using the extracts of β‐CS/β‐TCP composites developed in our previous in vivo study, and investigated the effects of the extracts on osteogenic differentiation of rat bone marrow‐derived mesenchymal stem cells (rBMSCs) and its related mechanisms. The angiogenic potential of the extracts was also evaluated using human umbilical vein endothelial cells (HUVECs). In the absence of osteogenic supplements, the osteogenic differentiation of rBMSCs was detected by alkaline phosphatase (ALP) activity assay and the messenger RNA expression of a panel of osteoblast markers. The results showed that the soluble ions of porous β‐CS/β‐TCP composites were capable of promoting cell viability, directly inducing cell differentiation. The increase in phosphorylation of AMP‐activated protein kinase (AMPK) and ERK1/2 were observed in rBMSCs cultured in β‐CS/β‐TCP composite extracts. The ALP expression, calcium deposition, and ERK1/2 phosphorylation of rBMSCs, which was promoted by ions released from β‐CS/β‐TCP composites, were blocked by an AMPK inhibitor, Compound C. These results indicate that bioactive ions extracted from β‐CS/β‐TCP composites could stimulate the osteogenic differentiation of rBMSCs via the AMPK‐Erk1/2 pathway. Interestingly, the secretion of vascular endothelial growth factor and the viability of HUVECs were shown to be enhanced in the presence of extracts from the β‐CS/β‐TCP composite scaffolds. Our findings suggest that 50 or 80% wt. CS could promote bone regeneration by stimulating osteogenesis and angiogenesis. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2096–2104, 2014.
Perfluorocarbon emulsion improves oxygen transport of normal and sickle cell human blood in vitro
Authors: Torres Filho Ivo P. , Pedro José Ricardo P. , Narayanan Srinivasan V. , Nguyen Nguyen M. , Roseff Susan D. , Spiess Bruce D. 
Published: July 2013

AbstractPerfluorocarbons (PFC) are compounds with high gas solubility that could help deliver O2 to tissues and have been suggested as adjunct therapy to ischemia. Using a newly designed in vitro system, we tested the hypothesis that a third generation PFC emulsion (Oxycyte) increased O2 transport of blood by measuring changes in O2 extraction ratio. The system included a computer‐controlled pump and blood‐gas exchange chambers to oxygenate and deoxygenate the blood from nine sickle cell disease (SCD) patients and five healthy donors. The flowing blood reached various levels of hemoglobin O2 saturation and O2 partial pressures (PO2), measured using a CO‐oximeter and a blood gas analyzer. The mixtures were kept at physiological blood pressure and temperature, constant flow, normobaric conditions, and FiO2 = 0.30. After adding PFC, the measurements suggested an increase in the transport of O2 and CO. Addition of PFC resulted in larger PO2 difference from 15 ± 2 mmHg to 23 ± 2 mmHg. Using normal blood and blood from SCD patients, the average O2 extraction ratio (O2ER) after PFC was significantly higher than baseline. Addition of saline did not cause statistically significant changes. The data suggest increased (facilitated) O2 transport by this PFC emulsion in both normal and SCD blood. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2105–2115, 2014.
A review of block copolymer‐based biomaterials that control protein and cell interactions
Authors: Bhushan Bharat , Schricker Scott R. 
Published: July 2013

AbstractBlock copolymers posses the ability to phase separate into micro and nanoscale patterns resulting in nonhomogeneous surfaces and solids. This nonhomogeneity has been harnessed to improve mechanical properties, control degradation, and add functionality to biomaterials. The ability of block copolymers to generate a wide variety of surface chemistries and morphologies can also be harnessed to control protein adsorption, protein conformation, and cell adhesion. Proteins and cells will respond to periodically structured surfaces, so block copolymers have a great deal of potential as biomaterials. This review will explore the ability of block copolymers to control specific biological responses such as cell adhesion, protein adsorption and conformation, parameters that govern the overall host response to a material. In addition, some of the specific applications of block copolymer, antithrombogenic materials and their ability to pattern proteins, will be discussed. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2467–2480, 2014.
Adipose‐derived mesenchymal stem cells for cartilage tissue engineering: State‐of‐The‐Art inin vivostudies
Authors: Veronesi Francesca , Maglio Melania , Tschon Matilde , Aldini Nicolò Nicoli , Fini Milena 
Published: July 2013

AbstractSeveral therapeutic approaches have been developed to address hyaline cartilage regeneration, but to date, there is no universal procedure to promote the restoration of mechanical and functional properties of native cartilage, which is one of the most important challenges in orthopedic surgery. For cartilage tissue engineering, adult mesenchymal stem cells (MSCs) are considered as an alternative cell source to chondrocytes. Since little is known about adipose‐derived mesenchymal stem cell (ADSC) cartilage regeneration potential, the aim of this review was to give an overview ofin vivostudies about the chondrogenic potential and regeneration ability of culture‐expanded ADSCs when implanted in heterotopic sites or in osteoarthritic and osteochondral defects. The review compares the different studies in terms of number of implanted cells and animals, cell harvesting sites,in vitroexpansion and chondrogenic induction conditions, length of experimental time, defect dimensions, used scaffolds and post‐explant analyses of the cartilage regeneration. Despite variability of thein vivoprotocols, it seems that good cartilage formation and regeneration were obtained with chondrogenically predifferentiated ADSCs (1 × 107cells for heterotopic cartilage formation and 1 × 106cells/scaffold for cartilage defect regeneration) and polymeric scaffolds, even if many other aspects need to be clarified in future studies. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2448–2466, 2014.
Speciation Analysis of Cr(III) and Cr(VI) after Solid Phase Extraction Using Modified Magnetite Nanoparticles
Authors: Karimi Mohammad Ali , Shahin Rasul , Mohammadi Sayed Zia , Hatefi‐Mehrjardi Abdolhamid , Hashemi Javad , Yarahmadi Javad 
Published: July 2013

AbstractA new solid phase extraction (SPE) method has been developed for the speciation of Cr(III) and Cr(VI). This method is based on the adsorption of Cr(VI) on modified alumina‐coated magnetite nanoparticles (ACMNPs). Total chromium in different samples was determined as Cr(VI) after oxidation of Cr(III) to Cr(VI) using H2O2. The chromium concentration has been determined by flame atomic absorption spectrometric (FAAS) technique and amount of Cr(III) was calculated by substracting the concentration of Cr(VI) from total chromium concentration. The effect of parameters such as pH, amount of adsorbent, contact time, sample volume, eluent type, H2O2 concentration and cetyltrimethylammonium bromide (CTAB) concentration as modifier on the quantitative recovery of Cr(VI) were investigated. Under the optimal experimental conditions, the preconcentration factor, detection limit, linear range and relative standard deviation (RSD) of Cr(VI) were 140 (for 350 mL of sample solution), 0.083 ng mL−1, 0.1‐10.0 ng mL−1 and 4.6% (for 5.0 ng mL−1, n = 7), respectively. This method avoided the time‐consuming column‐passing process of loading large volume samples in traditional SPE through the rapid isolation of CTAB@ACMNPs with an adscititious magnet. The proposed method was successfully applied to the determination and speciation of chromium in different water and wastewater samples and suitable recoveries were obtained.
Development of a Liquid Chromatography Tandem Mass Spectrometry Method for Identification of Flavonoids in Ginkgo biloba
Authors: Ko Yen‐Chen , Lee Ren‐Jye , Feng Hai‐Tung , Lee Maw‐Rong 
Published: July 2013

AbstractA rapid, selective and sensitive method for analysis of trace flavonoids and its glycoside derivatives in ginkgo has proposed. Ultrasonic‐assisted extraction of sample preparation was adopted to extract trace flavonoids in ginkgo leaf and its processed product. The compounds were identified using liquid chromatography negative electrospray ionization triple quadrupole tandem mass spectrometry (MS/MS). The neutral loss scan mode of MS/MS was used to screen flavonoid compounds and those compounds with acid group, or having rhamnosyl, glucosyl, or coumaroyl moiety in the samples. The successive data‐dependent product ion scan mode of MS/MS was used to identify the structure of the components. The analytical results represented three aglycone flavonoids and seven flavonoid glycosides in ginkgo. The method detection limits were evaluated for the analytes analyzed in the range of 0.88 to 2.67 μg/mL.
Ionization emissions associated with N2+ 1N band in halos without visible sprite streamers
Authors: Kuo C. L. , Williams E. , Bór J. , Lin Y. H. , Lee L. J. , Huang S. M. , Chou J. K. , Chen A. B. , Su H. T. , Hsu R. R. , Sátori G. , Frey H. U. , Mende S. B. , Takahashi Y. , Lee L. C. 
Published: July 2013

AbstractWe report the ionization emission associated with N2+ 1N band in a halo event without visible sprite streamers. To avoid the lightning contamination to the ionization emission, we find halos whose parent lightning light is blocked by the Earth's limb. Five halos in the 2004–2010 Imager of Sprites and Upper Atmospheric Lightning data set were identified as halos without visible sprite streamers. A halo with maximum N2 1P brightness had significant ionization emission of N2+ 1N. The time‐integrated photon intensity of N2 1P, N2 2P, and N2+ 1N emission is 2.2 × 105, 2.1 × 104, and 7.4 × 102 photons cm−2, respectively at a distance of 4130 km. The total number of photons of N2 1P, N2 2P, and N2+ 1N band emissions are 4.6 × 1023, 4.3 × 1022, and 1.6 × 1021 photons, respectively. In the halo region, the electron density increased as 1–2 orders of magnitude higher than ambient electron density. From the emission ratio of N2+ 1N to N2 2P, the reduced electric field is estimated to be 275–325 Td that is higher than the conventional breakdown electric field. The recorded electric field related to this halo event is produced by a lightning discharge that has a total charge moment change of −1450 C km. Based on the estimated electric field from optical emissions, it is found that the lightning‐induced electric field in the bright halo region is significantly relaxed with a rate faster than that estimated using ambient electron density, in agreement with previous modeling results showing that the electron density enhancement due to the ionization processes leads to a short dielectric relaxation time inside the halo region.
Rapid‐run ionosonde observations of traveling ionospheric disturbances in the auroral ionosphere
Authors: Kozlovsky Alexander , Turunen Tauno , Ulich Thomas 
Published: July 2013

AbstractSince 2007, the Sodankylä Geophysical Observatory routinely performs vertical ionosphere soundings once per minute, using a frequency‐modulated continuous‐wave chirp at the rate of 500 kHz/s from 500 kHz to 16 MHz. We used these data to study traveling ionospheric disturbances (TIDs) during 10–16 local time. The observations were made between April 2007 and June 2012, mostly during low solar activity. The TIDs were studied in five bands of periods corresponding to the following: infrasonic (acoustic) waves and the buoyancy cutoff (periods from 5 to 10 min); small‐scale gravity waves (GWs; 10–15 min); medium‐scale (MS; 15–30 min) GWs; medium‐large scale (MS‐LS; 30–60 min) GWs; and large‐scale (LS; 60–120 min) GWs. Relative contribution (with respect to LS TIDs) of the short‐period (5–15 min) and MS (15–30 min) TIDs shows minima in winter and maxima in summer. These annual variations anticorrelate with variations of true height, namely, the largest relative amplitudes occur in summer, when TIDs were observed at minimal heights. We suggest that the summer increase of shorter‐period TIDs is due to lowering reflection to the height where the Brunt‐Väisälä period is smaller and, hence, shorter‐period gravity waves exist. The summer maxima were most prominent during the 3 years of minimal solar activity (2008–2010). In 2011, when solar activity increased, the annual variation seems less prominent. Annual variations of the longer‐period (30–120 min) TIDs are essentially less significant. For all TIDs, no obvious dependences on the AE and Ap indices of magnetic activity were found.
Arctic warming and your weather: public belief in the connection
Authors: Hamilton Lawrence C. , Lemcke‐Stampone Mary 
Published: July 2013

ABSTRACTWill Arctic warming affect mid‐latitude weather? Many researchers think so, and have addressed this question through scientific articles and news media. Much of the public accepts such a connection as well. Across three New Hampshire surveys with more than 1500 interviews, 60% of respondents say they think future Arctic warming would have major effects on their weather. Arctic/weather responses changed little after Superstorm Sandy brushed the region, but exhibit consistently strong partisan divisions that grow wider with education. Belief in an Arctic/weather connection also varies, in a nonlinear pattern, with the temperature anomaly around day of interview. Interviewed on unseasonably warm or cool days, respondents are more likely to think that Arctic warming would have major effects on their weather. This unscientific response seems to mirror the scientific discussion about extremes.