bluuebunny/crossref_metadata_2025 huggingface dataset:
Regularization in parallel MR image reconstruction
Authors: Omer Hammad , Dickinson Robert
Published: March 2011

Parallel MRI has brought forward new applications by reducing the scan time in MR image acquisition. The acceleration is achieved by reducing the number of phase encode steps acquired during the image acquisition thus giving aliased images. Sensitivity encoding (SENSE) is a widely used method to unwrap the aliased images. One major problem is the noise amplification during the process of reconstruction as well as the artifacts, which may arise during the reconstruction process. Regularization is an important tool to reduce this noise amplification (measured by geometry factor [g‐factor]) and the artifacts, but it is computationally expensive. This work aims at exploring an alternative to regularization that would not be computationally expensive. The alternative suggested uses wavelet denoising of the coil sensitivity maps before applying standard SENSE reconstruction algorithm. The results of this reconstruction are compared with the reconstruction obtained by Tikhonov regularization. The results show that for lower acceleration factors (AFs; 2 and 3), the wavelet denoising of sensitivity maps before applying standard SENSE produces comparable results to those of Tikhonov regularization at much lesser computational cost but for higher AFs Tikhonov regularization is a better choice to acquire good quality images. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part A 38A: 52–60, 2011.
Three‐dimensional quadrature array coil elements for improved parallel magnetic resonance imaging performance at 1.5 Tesla
Authors: Mueller Matthias F. , Lanz Titus , Breuer Felix , Griswold Mark A. , Jakob Peter M.
Published: March 2011

In this study, a special concept of 3D quadrature array coil elements is presented. It allows for doubling the number of phased‐array coil elements over a localized region of interest (ROI) without the necessity of reducing the sizes of the elements below optimal dimensions and thus losing performance due to domination of the noise of the elements. In this study, a 3D quadrature array coil element is formed of a planar coil element in combination with a perpendicular orientated, geometrically decoupled, second coil element. Simulation results of such a perpendicular arrangement of single coil elements are presented demonstrating the improvement in spatial sensitivity distribution and signal‐to‐noise ratio (SNR) over the localized ROI. In addition, an eight‐channel prototype array coil was built out of 3D quadrature array elements approving the advantageous encoding capabilities and SNR performance of the presented concept by in vivo T2‐weighted spin‐echo imaging studies on the thoracic human spinal cord. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part A 38A: 61–73, 2011.
Configuring large‐scale storage using a middleware with machine learning
Authors: Eyers David M. , Routray Ramani , Zhang Rui , Willcocks Douglas , Pietzuch Peter
Published: March 2011

The proliferation of cloud services and other forms of service‐oriented computing continues to accelerate. Alongside this development is an ever‐increasing need for storage within the data centres that host these services. Management applications used by cloud providers to configure their infrastructure should ideally operate in terms of high‐level policy goals, and not burden administrators with the details presented by particular instances of storage systems. One common technology used by cloud providers is the Storage Area Network (SAN). Support for seamless scalability is engineered into SAN devices. However, SAN infrastructure has a very large parameter space: their optimal deployment is a difficult challenge, and subsequent management in cloud storage continues to be difficult.

parindent = 10pt In this article, we discuss our work in SAN configuration middleware, which aims to provide users of large‐scale storage infrastructure such as cloud providers with tools to assist them in their management and evolution of heterogeneous SAN environments. We propose a middleware rather than a stand‐alone tool so that the middleware can be a proxy for interacting with, and informing, a central repository of SAN configurations. Storage system users can have their SAN configurations validated against a knowledge base of best practices that are contained within the central repository. Desensitized information is exported from local management applications to the repository, and the local middleware can subscribe to updates that proactively notify storage users should particular configurations be updated to be considered as sub‐optimal, or unsafe. Copyright © 2011 John Wiley & Sons, Ltd.
Specifying and enforcing the principle of least privilege in role‐based access control
Authors: Ma Xiaopu , Li Ruixuan , Lu Zhengding , Lu Jianfeng , Dong Meng
Published: March 2011

The principle of least privilege in role‐based access control is an important area of research. There are two crucial issues related to it: the specification and the enforcement. We believe that the existing least privilege specification schemes are not comprehensive enough and few of the enforcement methods are likely to scale well. In this paper, we formally define the basic principle of least privilege problem and present different variations, called the delta‐approx principle of least privilege problem and the minimizing‐approx principle of least privilege problem. Since there may be more than one result to enforce the same principle of least privilege, we introduce the notation about weights of permissions and roles to optimize the results. Then we prove that all least privilege problems are NP‐complete. As an important contribution of the paper, we show that the principle of least privilege problem can be reduced to minimal cost set covering (MCSC) problem. We can borrow the existing solutions of MCSC to solve the principle of least privilege problems. Finally, different algorithms are designed to solve the proposed least privilege problems. Experiments on performance study prove the superiority of our algorithms. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of Spatial Constraints and Brønsted Acid Site Locations on para‐Terphenyl Ionization and Charge Transfer in Zeolites
Authors: Belhadj Fatima , Moissette Alain , Brémard Claude , Hureau Matthieu , Derriche Zoubir
Published: March 2011

The locations of Brønsted acid sites (BAS) in the channels of medium‐pore zeolites have a significant effect on the spontaneous ionization of para‐terphenyl (PP3) insofar as spatial constraints determine the stability of transition states and charge‐transfer complexes relevant to charge separation. The ionization rates and ionization yield values demonstrate that a strong synergy exists between the H+ polarization energy and spatial constraints imposed by the channel topology. Spectroscopic and modeling results show that PP3 incorporation, charge separation, charge transfer and charge recombination differ dramatically among zeolites with respect to channel structure (H‐FER, H‐MFI, H‐MOR) and BAS density in the channel. Compartmentalization of ejected electrons away from the initial site of ionization decreases dramatically the propensity for charge recombination. The main mode of PP3.+ decay is hole transfer to form AlO4H.+⋅⋅⋅PP3 charge‐transfer complexes characterized by intense absorption in the visible range. According to the nonadiabatic electron‐transfer theory, the small reorganization energy in constrained channels explains the slow hole‐transfer rate.
High‐Resolution Electronic Spectroscopy Studies of meta‐Aminobenzoic Acid in the Gas Phase Reveal the Origins of its Solvatochromic Behavior
Authors: Fleisher Adam J. , Morgan Philip J. , Pratt David W.
Published: March 2011

A theoretical and experimental investigation of meta‐aminobenzoic acid (MABA) in the gas phase is presented, with the goal of understanding counterintuitive observations on the solvatochromism of this “push‐pull” molecule. The adiabatic excitation energies, transition moments, and excited‐state structures are examined using the complete active space self‐consistent field approach (CASSCF and CASPT2), which shows the first excited electronic state of MABA to be of greater charge transfer character than was found in the para‐isomer (PABA). The rotationally resolved electronic spectrum of MABA reveals the existence of two rotamers, owing to asymmetry in the carboxylic acid functional group. Stark measurements in a molecular beam show the change in permanent dipole moment upon excitation to be Δμ≈3.5 D for both rotamers, more than three times larger than that found in PABA. The excited state measurements reported here, along with supporting data from theory, clearly demonstrate how the meta‐directing effects of asymmetric substitution in aniline derivatives can drive charge transfer pathways in the isolated molecule.
A class of digitally programmable nth‐order filters
Authors: Alzaher Hussain , Tasadduq Noman , Al‐Ees Osama
Published: March 2011

A family of new high‐order filters capable of providing all filter functions without changing the circuit topology is proposed for integrated circuit applications. The proposed filters are based on simple active elements, namely, digitally controlled current amplifiers (DCCAs) and unity gain voltage buffers (VBs). Gains of DCCAs are digitally programmed to adjust the coefficients of transfer functions. R2R ladders are also utilized to increase the tuning flexibility of the proposed filters. A filter replicating the famous KHN biquad is extended to realize general nth‐order filters. Comparison with the recent works shows that the proposed approach results in more efficient realizations compared with its counterparts based on other current‐mode active elements. Experimental results obtained from a fourth‐order filter implemented using devices fabricated in a 0.35‐µm CMOS process are provided. Copyright © 2011 John Wiley & Sons, Ltd.
Cytometric solutions in veterinary andrology: Developments, advantages, and limitations
Authors: Petrunkina A. M. , Harrison R. A. P.
Published: March 2011

Cytometric methodologies are becoming increasingly important in veterinary andrology as means of assessing sperm function. However, as yet, flow cytometric techniques in veterinary andrology have not kept up in sophistication with those in other areas of biology and medicine. In this brief review, we consider the present state of cytometry in andrological procedures for evaluating the fertility of domestic animal sires. We outline the aspects of sperm physiology, paying particular attention to the changes that take place during the process known as capacitation, which prepares the sperm for interaction with the egg. We then examine briefly but critically the cytometric techniques that are currently in commercial use or are being established in research laboratories for testing sperm characteristics. Current limitations and potential developments in semen assessment are discussed. Recent research knowledge offers possibilities for applying more subtle flow cytometric approaches to distinguish different levels of fertilizing potential in semen samples. For example, linking field fertility data to multiparametric kinetic studies of sperm capacitational changes rather than “single parameter—single time point” estimations may reveal that slower rather than rapid changes indicate high fertility. Moreover, the development of multicolor flow cytometric procedures as a means of evaluating multiple functional parameters in individual cells would reduce the uncertainties always inherent in predicting fertility from in vitro sperm evaluation tests. © 2011 International Society for Advancement of Cytometry
Scheduling of frequently communicating tasks
Authors: Papazachos Zafeirios C. , Karatza Helen D.
Published: March 2011

Gang scheduling is an efficient resource management scheme for distributed systems which combines elements of time sharing and space sharing. It is a suitable technique particularly in the case when parallel tasks have to be running concurrently to make progress in communication. This paper studies the impact on scheduling performance when dynamically generated sequential gangs exist in the workload. In the case of sequential gangs, a subsequent gang can be dynamically generated after the execution of the initial gang based on affinity information which resides on the caches of the previously seized processors. The performance of different gang‐scheduling algorithms is examined for various cases of workload compositions which range from cases with a low demand for dynamically generated gangs to cases with a high ratio of sequential gangs to solitary gangs. A simulation model is implemented to address associated performance issues. Copyright © 2011 John Wiley & Sons, Ltd.
Intravascular pillars and pruning in the extraembryonic vessels of chick embryos
Authors: Lee Grace S. , Filipovic Nenad , Lin Miao , Gibney Barry C. , Simpson Dinee C. , Konerding Moritz A. , Tsuda Akira , Mentzer Steven J.
Published: March 2011

To investigate the local mechanical forces associated with intravascular pillars and vessel pruning, we studied the conducting vessels in the extraembryonic circulation of the chick embryo. During the development days 13–17, intravascular pillars and blood flow parameters were identified using fluorescent vascular tracers and digital time‐series video reconstructions. The geometry of selected vessels was confirmed by corrosion casting and scanning electron microscopy. Computational simulations of pruning vessels suggested that serial pillars form along pre‐existing velocity streamlines; blood pressure demonstrated no obvious spatial relationship with the intravascular pillars. Modeling a Reynolds number of 0.03 produced 4 pillars at approximately 20‐μm intervals matching the observed periodicity. In contrast, a Reynolds number of 0.06 produced only 2 pillars at approximately 63‐μm intervals. Our modeling data indicated that the combination of wall shear stress and gradient of shear predicted the location, direction, and periodicity of developing pillars. Developmental Dynamics 240:1335–1343, 2011. © 2011 Wiley‐Liss, Inc.
Conditional deletion of N‐Myc disrupts neurosensory and non‐sensory development of the ear
Authors: Kopecky Benjamin , Santi Peter , Johnson Shane , Schmitz Heather , Fritzsch Bernd
Published: March 2011

Ear development requires interactions of transcription factors for proliferation and differentiation. The proto‐oncogene N‐Myc is a member of the Myc family that regulates proliferation. To investigate the function of N‐Myc, we conditionally knocked out N‐Myc in the ear using Tg(Pax2‐Cre) and Foxg1KiCre. N‐Myc CKOs had reduced growth of the ear, abnormal morphology including fused sensory epithelia, disrupted histology, and disorganized neuronal innervation. Using Thin‐Sheet Laser Imaging Microscopy (TSLIM), 3D reconstruction and quantification of the cochlea revealed a greater than 50% size reduction. Immunochemistry and in situ hybridization showed a gravistatic organ‐cochlear fusion and a “circularized” apex with no clear inner and outer hair cells. Furthermore, the abnormally developed cochlea had cross innervation from the vestibular ganglion near the basal tip. These findings are put in the context of the possible functional relationship of N‐Myc with a number of other cell proliferative and fate determining genes during ear development. Developmental Dynamics 240:1373–1390, 2011. © 2011 Wiley‐Liss, Inc.
Representations and beliefs about eating disorders in a sample of french adolescents
Authors: Rousseau Amélie , Callahan Stacey , Chabrol Henri
Published: March 2011

Objective:

Body dissatisfaction and psychological problems are cited as the major cause of anorexia nervosa (AN) and bulimia nervosa (BN). Behavioral characteristics most often associated with AN and BN are food restriction, vomiting, and excessive exercise. The objective of this study was to examine representations and beliefs about AN and BN in a sample of French adolescents.

Method:

The sample was composed of 942 adolescents (16.4 years ± 1.2; 59.1% girls and 40.9% boys).

Results:

Excessive thinness and health problems were the physical characteristics most often associated with eating disorders (ED). A majority of the adolescents believe that ED most often manifest in adolescent females and were conscious of the gravity and chronic nature of ED; thinness was appropriately associated with AN, but many had erroneous beliefs regarding BN.

Discussion:

The results of this study provide insight into what young people in France believe and understand about the two major ED and advocate for more available information concerning BN for this population. © 2011 Wiley Periodicals, Inc. (Int J Eat Disord 2012)
Soluble flagellin, FliC, induces an Ag‐specific Th2 response, yet promotes T‐bet‐regulated Th1 clearance of Salmonella typhimurium infection
Authors: Bobat Saeeda , Flores‐Langarica Adriana , Hitchcock Jessica , Marshall Jennifer L. , Kingsley Robert A. , Goodall Margaret , Gil‐Cruz Cristina , Serre Karine , Leyton Denisse L. , Letran Shirdi E. , Gaspal Fabrina , Chester Rebecca , Chamberlain Jayne L. , Dougan Gordon , López‐Macías Constantino , Henderson Ian R. , Alexander James , MacLennan Ian C. M. , Cunningham Adam F.
Published: March 2011

Clearance of disseminated Salmonella infection requires bacterial‐specific Th1 cells and IFN‐γ production, and Th1‐promoting vaccines are likely to help control these infections. Consequently, vaccine design has focused on developing Th1‐polarizing adjuvants or Ag that naturally induce Th1 responses. In this study, we show that, in mice, immunization with soluble, recombinant FliC protein flagellin (sFliC) induces Th2 responses as evidenced by Ag‐specific GATA‐3, IL‐4 mRNA, and protein induction in CD62Llo CD4+ T cells without associated IFN‐γ production. Despite these Th2 features, sFliC immunization can enhance the development of protective Th1 immunity during subsequent Salmonella infection in an Ab‐independent, T‐cell‐dependent manner. Salmonella infection in sFliC‐immunized mice resulted in augmented Th1 responses, with greater bacterial clearance and increased numbers of IFN‐γ‐producing CD4+ T cells, despite the early induction of Th2 features to sFliC. The augmented Th1 immunity after sFliC immunization was regulated by T‐bet although T‐bet is dispensable for primary responses to sFliC. These findings show that there can be flexibility in T‐cell responses to some subunit vaccines. These vaccines may induce Th2‐type immunity during primary immunization yet promote Th1‐dependent responses during later infection. This suggests that designing Th1‐inducing subunit vaccines may not always be necessary since this can occur naturally during subsequent infection.
A dose‐dependent role for EBF1 in repressing non‐B‐cell‐specific genes
Authors: Lukin Kara , Fields Scott , Guerrettaz Lisa , Straign Desiree , Rodriguez Valerie , Zandi Sasan , Månsson Robert , Cambier John C. , Sigvardsson Mikael , Hagman James
Published: March 2011

In the absence of early B‐cell factor 1 (EBF1), B‐cell development is arrested at an uncommitted progenitor stage that exhibits increased lineage potentials. Previously, we investigated the roles of EBF1 and its DNA‐binding partner Runx1 by evaluating B lymphopoiesis in single (EBF1het and Runx1het) and compound haploinsufficent (Ebf1+/−Runx1+/−, ERhet) mice. Here, we demonstrate that decreased Ebf1 gene dosage results in the inappropriate expression of NK‐cell lineage‐specific genes in B‐cell progenitors. Moreover, prolonged expression of Ly6a/Sca‐1 suggested the maintenance of a relatively undifferentiated phenotype. These effects were exacerbated by reduced expression of Runx1 and occurred despite expression of Pax5. Repression of inappropriately expressed genes was restored in most pre‐B and all immature B cells of ERhet mice. Enforced EBF1 expression repressed promiscuous transcription in pro‐B cells of ERhet mice and in Ebf1−/−Pax5−/− fetal liver cells. Together, our studies suggest that normal levels of EBF1 are critical for maintaining B‐cell identity by directing repression of non‐B‐cell‐specific genes.
Amine‐Templated Cobalt(II) Coordination Polymer Exhibiting Novel Magnetic Properties: Effect of Dehydration
Authors: Nagaraja C. M. , Kumar Nitesh , Maji Tapas Kumar , Rao C. N. R.
Published: March 2011

An amine‐templated 2D coordination polymer of CoII with the formula {[EDAH2][Co2F2(SO4)2(H2O)2]}n (1) (EDA = ethylenediamine), has been synthesised and structurally characterised. It consists of a 1D chain bridged by F– ions, which are interconnected by SO42– tetrahedra forming a 2D [Co2F2(SO4)2(H2O)2]n2– corrugated sheet. The diprotonated cation [EDAH2] is intercalated between the sheets. Temperature‐dependent magnetic measurements reveal the presence of spin‐canted antiferromagnetism and hard‐magnet‐like behaviour with large a magnetic hysteresis with a coercive field (Hc) of 16.2 kOe and a remnant magnetisation (MR) of 1.64 μB. The coordinated water molecules in 1 can be removed by heating at 250 °C under vacuum to obtain the dehydrated phase {[EDAH2][Co2F2(SO4)2]}n (1′), which – upon exposure to water vapour for 24 h – gave the monoaqua compound, {[EDAH2][Co2F2(SO4)2(H2O)]}n (1″). This dehydration/rehydration process is accompanied by a structural transformation and a magnetic phase transition between the spin‐canted antiferromagnetic state of the hydrated phase to the antiferromagnetic state of the dehydrated phase.
Chemoselective Reduction of Isatin‐Derived Electron‐Deficient Alkenes Using Alkylphosphanes as Reduction Reagents
Authors: Cao Shu‐Hua , Zhang Xiu‐Chun , Wei Yin , Shi Min
Published: March 2011

Under mild reaction conditions, the C=C double bond inisatin‐derived electron‐deficient alkenes has been exclusively reduced in the presence of alkylphosphanes and water to afford the corresponding reduction products in good to excellent yields. A plausible mechanism is proposed on the basis of deuterium‐labeling experiments.
Calcium‐Catalyzed Direct Coupling of Alcohols with Organosilanes
Authors: Meyer Vera J. , Niggemann Meike
Published: March 2011

A calcium‐catalyzed direct substitution of π‐activated alcohols with different organosilanes under very mild reaction conditions is presented. The high reactivity of the calcium catalyst allows efficient conversion of secondary and tertiary allylic, secondary benzylic, and tertiary propargylic alcohols with allyltrimethylsilane at room temperature. Furthermore, the first direct substitution of an alcohol with (E)‐ as well as (Z)‐alkenylsilanes was achieved under mild reaction conditions.
Highly Stereoselective Total Synthesis of (+)‐9‐epi‐Dictyostatin and (–)‐12,13‐Bis‐epi‐dictyostatin
Authors: Zanato Chiara , Pignataro Luca , Ambrosi Andrea , Hao Zhongyan , Trigili Chiara , Díaz José Fernando , Barasoain Isabel , Gennari Cesare
Published: March 2011

The total syntheses of (+)‐9‐epi‐dictyostatin (1a) and (–)‐12,13‐bis‐epi‐dictyostatin (1b), diastereomers of the antimitotic marine sponge‐derived macrolide (–)‐dictyostatin (1), were achieved by creating 11 stereogenic centers and 4stereogenic double bonds with a high level of stereocontrol. The yield for the 29‐step longest linear sequence from Roche ester was 1.53 and 1.52 %, respectively. The final key steps to these unnatural products were the addition of vinylzincates C10‐C26 to aldehyde C1–C9 (leading surprisingly to complete stereoselectivity for the 9R‐configuration in 28a and for the 9S‐configuration in 12,13‐bis‐epimeric 28b), followed by Yamaguchi macrolactonization and global deprotection. (–)‐12,13‐Bis‐epi‐dictyostatin (1b) displayed a dramatic decrease of cytotoxicity and of the affinity toward the paclitaxel binding site of microtubules.
Environmental and cultural changes in highland Guatemala inferred from Lake Amatitlán sediments
Authors: Velez Maria I. , Curtis Jason H. , Brenner Mark , Escobar Jaime , Leyden Barbara W. , Popenoe de Hatch Marion
Published: March 2011

We inferred the late Holocene environmental history of the Guatemala highlands from multiple lines of evidence in a sediment core from Lake Amatitlán. Inferred environmental changes are generally synchronous with archaeologically documented highland Maya cultural shifts. Population increases in the Middle Preclassic, Early Classic, and Late Postclassic are associated with deforestation and soil erosion. Land abandonment in the Late Preclassic, Late Classic, and Early Postclassic is associated with evidence for reforestation and soil stabilization. Diatoms indicate relatively lower lake level and greater trophic status at times of reduced human impact, from ca. 250 B.C. to A.D. 125 and from ca. A.D. 875 to 1375. Decreased water levels were probably due to drier climate, to reforestation, or both. Lake eutrophication was caused by reduced water volume combined with a legacy of long‐term agricultural activity. Our data contribute to the understanding of relations among ancient Maya culture, climate, and environment. © 2011 Wiley Periodicals, Inc.
Neuropsychological screening performance and the association with activities of daily living and instrumental activities of daily living in dementia: baseline and 18‐ to 24‐month follow‐up
Authors: Monaci Linda , Morris Robin G.
Published: March 2011

Objective

The use of neuropsychological assessment beyond diagnosis is related partly to the extent to which it can indicate everyday function. This study investigates whether the associations between neuropsychological functioning, activities of daily living (ADL) and instrumental activities of daily living (IADL) change over an 18‐ to 24‐month follow‐up, exploring whether these change with dementia progression.

Method

Thirty‐four patients with probable Alzheimer's disease were assessed at baseline and again after between 18 and 24 months. Neuropsychological function was assessed using the revised Cambridge Cognitive Examination, which includes in it the Mini mental state examination and an executive functions scale. ADL and IADL were also measured, together with background neuropsychiatric features by using the Neuropsychiatric Inventory.

Results

Pearson correlations between the measures of daily functioning and cognitive abilities and neuropsychiatric symptoms showed that initially neuropsychological test results tended to correlate with IADL rather than ADL measures. Neuropsychiatric symptoms were not correlated whether IADL or ADL. At follow‐up, none of the neuropsychological function measures correlated with IADL or ADL, but neuropsychiatric symptoms were correlated with IADL.

Conclusions

At baseline, neuropsychological function is associated with IADL but not ADL. At follow‐up, the association between neuropsychological function and IADL diminishes, and associations between neuropsychiatric disturbances and IADL emerge. Copyright © 2011 John Wiley & Sons, Ltd.
Substituent effect on the antimony atom in organostibine‐mediated living radical polymerization
Authors: Kayahara Eiichi , Kondo Noriaki , Yamago Shigeru
Published: March 2011

The substituent effect on the antimony atom in organostibine‐mediated degenerative transfer living radical polymerization has been studied. 2‐Diphenylstibanyl‐2‐methylpropionitrile (1a) was synthesized as an organostibine chain transfer agent (CTA), and its effect was compared with the previously reported dimethylstibanyl analogue 1b. Both CTAs successfully polymerized butyl acrylate (BA) in a highly controlled manner giving poly(butyl acrylate)s possessing number average molecular weights close to the theoretical values determined by BA/1 ratios and narrow molecular weight distribution. The controllability of styrene polymerization by 1a was slightly decreased but the decrease is still at an acceptable level. However, 1a did not control the polymerization of methyl methacrylate (MMA). The results are in sharp contrast that 1b can highly control the polymerization of styrene and MMA. Kinetic studies using diphenylstibanyl‐substituted polystyrene macro‐CTA 2 in styrene polymerization revealed that the degenerative chain transfer reaction of the diphenylstibanyl group takes place faster than that of the dimethylstibanyl group, suggesting that the reactivity of the diphenylstibanyl group is not the origin of the low control. Chain extension experiments revealed the formation of a considerable amount of dead polymers when 1a was used as a CTA, and the frequent occurrence of termination reaction is the most probable origin of the low control. The addition of tetraphenyldistibine significantly increased the control of styrene and MMA polymerization, and structurally well‐defined polystyrene and poly(methyl methacrylate) were obtained by applying a binary system consisting from 1a and tetraphenyldistibine. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:307–315, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20681
Modular synthesis and photophysical and electrochemical properties of 2,3,5,6‐tetraaryl‐substituted benzo[1,2‐b:5,4‐b′]difurans
Authors: Tsuji Hayato , Mitsui Chikahiko , Sato Yoshiharu , Nakamura Eiichi
Published: March 2011

We developed a versatile synthesis of tetraaryl‐substituted benzo[1,2‐b:5,4‐b′]difurans (m‐BDFs) via a zinc‐mediated intramolecular double cyclization reaction of 4,6‐bis(phenylethynyl)‐1,3‐benzenediol, followed by a palladium‐catalyzed cross‐coupling reaction. In comparison with the corresponding benzo[1,2‐b:4,5‐b′]difuran (p‐BDF) isomers reported previously, the m‐BDFs are slightly wider between HOMO and LUMO, as well as a lower energy level of the former. These differences in properties between the structural isomers can be ascribed to the difference in the conjugation type. The compounds had high charge carrier mobility up to 1 × 10−3 cm2/Vs, which makes them attractive materials for organoelectronics applications. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:316–324, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20682
Intensive NMR study of 1‐t‐butyl‐3‐methyl‐2,4‐bis(2,4,6‐tri‐t‐butylphenyl)‐1,3‐diphosphacyclobutane‐2,4‐diyl
Authors: Yoshifuji Masaaki , Osborn Stefan T. , Arduengo Anthony J. , Belmore Kenneth A. , Ito Shigekazu
Published: March 2011

Detailed 1H‐, 13C‐, and 31P NMR studies of 1‐t‐butyl‐3‐methyl‐2,4‐bis(2,4,6‐tri‐t‐butylphenyl)‐1,3‐diphosphacyclobutane‐2,4‐diyl reveal several unusual coupling constants together with recognition of the diastereotopicity of the compound. These new data support an uncommon phosphorus‐containing molecular structure for the ring system. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:331–338, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20684
Isolation of tetraphenylselenurane
Authors: Bienfait André Marcel , Kubella Paul , Mueller Birgit , Seppelt Konrad
Published: March 2011

Tetraphenylselenurane has been isolated and structurally characterized by a single crystal structure determination. (a = 1752.1(7), b = 99.6(), c = 1074.2(4) pm, ß = 98.97(1)°, P21/c) It is a yellow crystalline material that explodes on warming to room temperature. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:576–578, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20686
Implicit social cognition and safety culture
Authors: Marquardt Nicki , Gades Ricarda , Robelski Swantje
Published: March 2011

Most models define safety culture as basic assumptions, attitudes, or values concerning organizational safety issues. When measuring safety cultures, many researchers have had their main focus on explicit safety‐critical attitudes and generally relied on specific survey instruments. It is questionable, however, whether self‐report measures can capture all aspects of organizational safety culture. Instead of getting direct answers, implicit measures rely on activating automatic attitudes derived from long‐term memory and measure the time it takes an individual to react to attitude‐evoking stimuli. This article deals with the relationship between implicit safety‐critical attitudes and safety culture. The first study involved the measurement of explicit and implicit safety‐critical attitudes from 376 participants working in various industries. The Implicit Association Test (IAT)—a latency‐based measurement approach—was applied to assess implicit safety‐critical attitudes. Explicit safety attitudes were measured by questionnaire. Implicit and explicit attitudes are both related to organizational safety performance indicators, such as data concerning accidents and near misses. The second study involved both types of safety‐critical attitudes that were used for predicting safety culture indicators on an individual level. An example of this is risk awareness. The first study's results show that explicit and implicit safety‐critical attitudes represent various aspects of an organizational safety culture and can be related to safety performance indicators on an organizational level. The second study's results indicate that implicitly measured attitudes have been better at predicting safety culture indicators on an individual level compared to explicit attitude. Recommendations for future research in the field of safety culture assessment are made. © 2011 Wiley Periodicals, Inc.
Performing ergonomics analyses through virtual interactive design: Validity and reliability assessment
Authors: Wu Tinghao , Tian Renran , Duffy Vincent G.
Published: March 2011

Virtual interactive design methodology was initially proposed as an integrated environment for digital human model–based ergonomics analysis of human–machine interactions, which uses a motion capture system and virtual environment to realize task simulation. The validity and reliability of this analysis methodology has not been systematically studied. In this article, potential errors are first investigated based on the technology used in the system structure and work process; then, three experimental integration levels are proposed to use different resources for creating manikin postures. Validity and reliability to use this integrated environment for static ergonomics analysis are then assessed by comparing the ergonomics analysis outputs achieved based on the three integration levels. The results indicate that the reliability of this methodology is good; however, the validity of the integrated system is affected by the limitation of the virtual environment used in the testing. © 2011 Wiley Periodicals, Inc.
The role of calculative attachment in the relationship between diversity climate and retention
Authors: Kaplan David M. , Wiley Jack W. , Maertz Carl P.
Published: March 2011

This study enhances our understanding of the complex relationship between diversity and employee retention. The study found that positive perceptions of an organization's “diversity climate” were related to decreased turnover intentions and found support for the proposition that calculative attachment mediated this relationship. In addition, the study considered potential interactions with diversity climate perceptions in predicting calculative attachment and found support for satisfaction with pay as a moderator, but not supervisor effectiveness. Finally, the study determined that the benefits of a positive diversity climate may extend to all employees, including White men. ©2011 Wiley Periodicals, Inc.
Inducements, contributions, and fulfillment in new employee psychological contracts
Authors: Lee Cynthia , Liu Jun , Rousseau Denise M. , Hui Chun , Chen Zhen Xiong
Published: March 2011

This longitudinal study of newly hired Chinese college graduates (N = 143) investigates the effects of contract fulfillment, employee reports of company inducements (organizational support and job rewards), and supervisory reports of individual contributions (job performance and extra‐role citizenship behavior) upon changes in the graduates' psychological contracts. Three survey waves were administered a year apart, starting with the recruits' job offer acceptance. Analyses revealed that employee fulfillment and perceived contributions predicted particular changes in employer psychological contract obligations, whereas employer fulfillment and perceived inducements predicted changes in employee obligations. The effects of inducements on employee obligation changes and contributions on employer obligation changes were mediated by their respective fulfillment measures. Changes in obligations were greater in the first year of employment than in the second. This study yields implications for managing newcomers and researching the initial phase of employment. ©2011 Wiley Periodicals, Inc.
Mandatory and binding arbitration: Effects on employee attitudes and recruiting results
Authors: Bernardin H. John , Richey Brenda E. , Castro Stephanie L.
Published: March 2011

This paper reports the results of two studies undertaken in the same Fortune 500 company as it adopted an Alternative Dispute Resolution (ADR) program. Study 1 assessed employees' perceptions of fairness, trust, and turnover intentions regarding ADR options. Compared with other options for ADR, a program consisting of mandatory mediation followed by mandatory and binding arbitration (MMBA) resulted in significantly lower levels of procedural fairness perception, organizational trust, and intentions to stay with the firm. Contrary to previous research, no significant effects were found related to respondents' demographic characteristics and their reactions to ADR program characteristics. In Study 2, job‐applicant flow data were evaluated and compared by corporate region to determine the effects of an MMBA program installed in one region. Results revealed no significant effects related to the MMBA program on the organization's ability to recruit and ultimately fill key positions. As in Study 1, no significant effects were found in Study 2 for the demographic characteristics of applicant race/ethnicity, gender, or age on applicant recruitment decisions. Although Study 2 results indicated job candidates are unaffected by the existence of an MMBA program, given Study 1's results, practitioners should be cautious about implementing such a program for current employees. © 2011 Wiley Periodicals, Inc.
The effect of primed goals on employee performance: Implications for human resource management
Authors: Shantz Amanda , Latham Gary
Published: March 2011

Overwhelming evidence in the behavioral sciences shows that consciously set goals can increase an employee's performance. Thus, HR professionals have had little, if any, reason to be interested in subconscious processes. In the past decade, however, laboratory experiments by social psychologists have shown that goals can be primed. That is, people's behavior is affected by goals of which they are unaware. Because a conscious goal consumes cognitive resources, this finding has important implications for employee efficiency in the workplace. This paper discusses the results of priming a performance goal in two organizational settings. Call center employees who were primed using a photograph of a woman winning a race raised significantly more money from donors than those who were randomly assigned to a control group. A meta‐analysis revealed that a photograph can prime the subconscious to increase job performance. The results of the present study demonstrate that subconscious motivation is a concept worthy of exploration for both human resource scholars and practitioners. © 2011 Wiley Periodicals, Inc.
Continuous measurement of spectrophotometric absorbance in peatland streamwater in northern England: implications for understanding fluvial carbon fluxes
Authors: Grayson Richard , Holden Joseph
Published: March 2011

Bog systems tend to have a flashy hydrological regime with low baseflows and rapid and high storm peaks. Water derived from peatlands often contains significant amounts of organic humic and fulvic materials which form the largest fraction of the dissolved organic carbon component of the fluvial carbon flux. However, most estimates of dissolved organic carbon flux from peatlands are based on sampling that is infrequent and which may miss the periods of high flux during storm events. In order to better characterize the behaviour and fluxes of fluvial carbon it is necessary to operate more frequent sampling. This paper presents data from a continuously operating field‐based spectrophotometer simultaneously measuring absorbance across 200–730 nm at 2·5 nm intervals in runoff from an upland peatland stream. It is shown that absorbance at different wavelengths that have previously been used to characterize dissolved organic carbon varies rapidly during storm events. The probe is shown to even detect changes in absorbance characteristics in response to rainfall events before the stream discharge starts to rise. The high‐resolution behaviour of absorbance characteristics during storm events is different depending on the wavelength studied. Thus, the choice of wavelength used as a proxy for dissolved organic carbon needs careful attention and it may be that automated spectrophotometric methods which provide rich time‐series data from across the spectrum can tell us more about fluxes, processes and sources of aquatic carbon in peatland systems in the future than traditional practices have hitherto allowed. Copyright © 2011 John Wiley & Sons, Ltd.
EFFECTS OF SEASONAL WATER USE AND APPLIED N FERTILIZER ON WHEAT WATER PRODUCTIVITY INDICES
Authors: Montazar Aliasghar , Azadegan Behzad
Published: March 2011

A field experiment was conducted for three growing seasons to study the effects of seasonal water use and applied N fertilizer on grain yield and water productivity indices of wheat in an arid region. The results revealed that the yield response to N was associated with water application levels. The water productivity indices were influenced by irrigation strategies, and deficit irrigation effectively boosted productivity of irrigation water (WPI). The highest WPI was obtained at a seasonal irrigation water of 156 mm for different levels of applied nitrogen. For levels of applications 70% of the required nitrogen, required nitrogen, and 120% of the required nitrogen, WPI ranged between 0.93 and 2.28, 1.30 and 2.75, and 0.98 and 2.47 kg m−3, respectively. The data generated here indicate that maximum water productivity (WPE) would be achieved when 98 kg N ha−1 is combined with 156 mm of supplemental irrigation (2.72 kg m−3). Consequently, when limited irrigation water is combined with N fertilizer appropriate management, water productivity can be substantially and consistently increased in arid regions. Copyright © 2011 John Wiley & Sons, Ltd.
Decellularized extracellular matrix derived from human adipose tissue as a potential scaffold for allograft tissue engineering
Authors: Choi Ji Suk , Kim Beob Soo , Kim Jun Young , Kim Jae Dong , Choi Young Chan , Yang Hyun‐Jin , Park Kinam , Lee Hee Young , Cho Yong Woo
Published: March 2011

Decellularized tissues composed of extracellular matrix (ECM) have been clinically used to support the regeneration of various human tissues and organs. Most decellularized tissues so far have been derived from animals or cadavers. Therefore, despite the many advantages of decellularized tissue, there are concerns about the potential for immunogenicity and the possible presence of infectious agents. Herein, we present a biomaterial composed of ECM derived from human adipose tissue, the most prevalent, expendable, and safely harvested tissue in the human body. The ECM was extracted by successive physical, chemical, and enzymatic treatments of human adipose tissue isolated by liposuction. Cellular components including nucleic acids were effectively removed without significant disruption of the morphology or structure of the ECM. Major ECM components were quantified, including acid/pepsin‐soluble collagen, sulfated glycosaminoglycan (GAG), and soluble elastin. In an in vivo experiment using mice, the decellularized ECM graft exhibited good compatibility to surrounding tissues. Overall results suggest that the decellularized ECM containing biological and chemical cues of native human ECM could be an ideal scaffold material not only for autologous but also for allograft tissue engineering. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2011.
Fabrication, characterization, and biological assessment of multilayer DNA coatings on sandblasted‐dual acid etched titanium surface
Authors: Liu Li , Song Li‐Na , Yang Guo‐Li , Zhao Shi‐Fang , He Fu‐Ming
Published: March 2011

As local gene therapy has received attention, immobilizing functional gene onto irregular oral implant surface has become an advanced challenge. Electrostatic layer‐by‐layer (LBL) assembly technique could achieve this goal and allow local and efficient administration of genes to the target cells. In this study, multilayers of cationic lipid/plasmid DNA (pEGFP‐C1) complex (LDc) and anionic hyaluronic acid were assembled onto sandblasted‐dual acid etched titanium disks by the LBL technique. Surface characteristics of the coatings were performed by x‐ray photospectroscopy (XPS), contact angle measurements, and scanning electron microscopy (SEM). The cell biological characteristics of the coatings were evaluated by in vitro experiments. SEM results demonstrated that the porous titanium surface was gradually flattened with the increase of the multilayer. The XPS survey indicated that the N element was found from the coating. The coating degradation and pEGFP‐C1 releasing kinetics showed that the more assembled layer numbers were, the larger the amount of DNA released in the first 30 h. MC3T3‐E1 cells were cultured directly on the DNA‐loaded surface. Higher enhanced green fluorescent protein (EGFP) expression efficiency was achieved by increasing the number of layers when cells were cultured after 24 or 72 h. The MC3T3‐E1 cell viability on the surface of multilayer DNA coatings was significantly higher than that on control porous titanium surface. It was concluded that the approach established by the LBL technique had great potential in immobilizing gene coatings onto the porous titanium surface and subsequently influenced the function of the cultured cell. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2011.
Short duration gluteraldehyde cross linking of decellularized bovine pericardium improves biological response
Authors: Umashankar P. R. , Arun T. , Kumari T. V.
Published: March 2011

Gluteraldehyde stabilized bovine pericardium is used for clinical application since 1970s because of its desirable features such as less immunogenicity and acceptable durability. However, a propensity for calcification and long term implant failure is reported because of gluteraldehyde treatment. There is also failure of implant to integrate into host tissue because of its resistance to tissue remodeling. Decellularized bovine pericardium, a potential alternative allows tissue remodeling but it has problems such as immunogenicity and chronic inflammatory response. In this study, decellularized bovine pericardium was subjected to short duration, low concentration gluteraldehyde cross‐linking at two levels and its biological response (both in vitro and in vivo) was compared with un‐crosslinked decellularized bovine pericardium and fully crosslinked normal bovine pericardium. It was observed that both un‐crosslinked and partially crosslinked decellularized bovine pericardium to be non‐cytotoxic and it caused significantly less inflammatory cytokine release such as TNF alpha and IL1beta from activated macrophages. Among all groups, short duration 0.2% Gluteraldehyde treated decellularized bovine pericardium showed significantly less antibody response and inflammatory response compared to un‐crosslinked decellularized pericardium, short duration 0.6% gluteraldehyde treated decellularized bovine pericardium or completely cross linked bovine pericardium in juvenile rat subcutaneous implantation model. Moreover, short duration 0.2% gluteraldehyde crosslinked decellularized bovine pericardium showed minimum calcification, better host fibroblast incorporation, new collagen deposition and angiogenesis within the implant. These attributes may finally lead to better implant remodeling and sustained implant function during clinical use. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2011.