bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the Impact of SERVQUAL Dimensions on Customer Satisfaction: The Lessons Learnt from Serbian Travel Agencies
Authors: Marinković Veljko , Senić Vladimir , Kocić Milan , Šapić Srđan
Published: December 2011

Despite the rise of online travel booking services, it seems that traditional travel agencies remain an intractable part in the process of making travel arrangements for most travelers. Nevertheless, the question remains as to what triggers travelers' satisfaction with travel agencies. In order to explore this, we focused on Serbian travel agencies and researched the impact of the five individual SERVQUAL dimensions on travelers' satisfaction. Results revealed that four SERVQUAL dimensions (reliability, responsiveness, empathy and tangibility) had a significant influence on customer satisfaction. Copyright © 2011 John Wiley & Sons, Ltd.
High‐resolution mapping of human brain metabolites by free induction decay 1H MRSI at 7 T
Authors: Bogner W. , Gruber S. , Trattnig S. , Chmelik M.
Published: December 2011

This work describes a new approach for high‐spatial‐resolution 1H MRSI of the human brain at 7 T. 1H MRSI at 7 T using conventional approaches, such as point‐resolved spectroscopy and stimulated echo acquisition mode with volume head coils, is limited by technical difficulties, including chemical shift displacement errors, B0/B1 inhomogeneities, a high specific absorption rate and decreased T2 relaxation times. The method presented here is based on free induction decay acquisition with an ultrashort acquisition delay (TE*) of 1.3 ms. This allows full signal detection with negligible T2 decay or J‐modulation. Chemical shift displacement errors were reduced to below 5% per part per million in the in‐slice direction and were eliminated in‐plane. The B1 sensitivity was reduced significantly and further corrected using flip angle maps. Specific absorption rate requirements were well below the limit (~20 % = 0.7 W/kg). The suppression of subcutaneous lipid signals was achieved by substantially improving the point‐spread function. High‐quality metabolic mapping of five important brain metabolites was achieved with high in‐plane resolution (64 × 64 matrix with a 3.4 × 3.4 × 12 mm3 nominal voxel size) in four healthy subjects. The ultrashort TE* increased the signal‐to‐noise ratio of J‐coupled resonances, such as glutamate and myo‐inositol, several‐fold to enable the mapping of even these metabolites with high resolution. Four measurement repetitions in one healthy volunteer provided proof of the good reproducibility of this method. The high spatial resolution allowed the visualization of several anatomical structures on metabolic maps. Free induction decay MRSI is insensitive to T2 decay, J‐modulation, B1 inhomogeneities and chemical shift displacement errors, and overcomes specific absorption rate restrictions at ultrahigh magnetic fields. This makes it a promising method for high‐resolution 1H MRSI at 7 T and above. Copyright © 2011 John Wiley & Sons, Ltd.
THE LOGICAL LIMITS OF BEST PRACTICE ADMINISTRATIVE SOLUTIONS IN DEVELOPING COUNTRIES
Authors: Andrews Matt
Published: December 2011

Developing countries are pressured to adopt administrative solutions that the international community considers best practice. Some claim that these practices do not fit such contexts. How could one assess the fit or relevance of a best practice? This article suggests a basic answer: Look at the degree of difference between the proposed adoption context and the context in which such practice emerged as ‘best’. This answer emerges from a discussion on the basis of the new institutional ideas about change and diffusion. An empirical analysis of public financial management reform in African countries suggests support for this answer: Good practices are most evident in countries least different to the developed nations where practices originated and least evident in countries most different to these developed nations. The article contributes to a literature on best practice and yields fundamental messages for development, including the point that best practices are limited as administrative solutions in many developing countries. Copyright © 2011 John Wiley & Sons, Ltd.
Fast and accurate modeling of protein–protein interactions by combining template‐interface‐based docking with flexible refinement
Authors: Tuncbag Nurcan , Keskin Ozlem , Nussinov Ruth , Gursoy Attila
Published: December 2011

The similarity between folding and binding led us to posit the concept that the number of protein–protein interface motifs in nature is limited, and interacting protein pairs can use similar interface architectures repeatedly, even if their global folds completely vary. Thus, known protein–protein interface architectures can be used to model the complexes between two target proteins on the proteome scale, even if their global structures differ. This powerful concept is combined with a flexible refinement and global energy assessment tool. The accuracy of the method is highly dependent on the structural diversity of the interface architectures in the template dataset. Here, we validate this knowledge‐based combinatorial method on the Docking Benchmark and show that it efficiently finds high‐quality models for benchmark complexes and their binding regions even in the absence of template interfaces having sequence similarity to the targets. Compared to “classical” docking, it is computationally faster; as the number of target proteins increases, the difference becomes more dramatic. Further, it is able to distinguish binders from nonbinders. These features allow performing large‐scale network modeling. The results on an independent target set (proteins in the p53 molecular interaction map) show that current method can be used to predict whether a given protein pair interacts. Overall, while constrained by the diversity of the template set, this approach efficiently produces high‐quality models of protein–protein complexes. We expect that with the growing number of known interface architectures, this type of knowledge‐based methods will be increasingly used by the broad proteomics community. Proteins 2012; © 2011 Wiley Periodicals, Inc.
A simple and efficient authentication scheme for mobile satellite communication systems
Authors: Lee Cheng‐Chi , Li Chun‐Ta , Chang Rui‐Xiang
Published: December 2011

In this article, the authors shall propose a simple and efficient authentication scheme for mobile satellite communication systems. The proposed scheme can achieve the following security requirements: (S1) withstand impersonation attacks; (S2) withstand denial server attacks; (S3) withstand smart card loss attacks; (S4) withstand replay attacks; and (S5) withstand stolen‐verifier attacks, and achieve the following functionality requirements: (F1) freely choose identity; (F2) provide mutual authentication; (F3) provide session key agreement; (F4) provide user anonymity; and (F5) provide perfect forward secrecy. In additional, the proposed scheme does not use the high complex computation, such as public key cryptosystem or secret key cryptosystem, for the mobile users' side. The proposed scheme is only based on hash functions and exclusive‐OR operations. Compared with other schemes, the proposed scheme has a lower computation cost. It is more simple and efficient scheme. Copyright © 2011 John Wiley & Sons, Ltd.
Non-stringent tissue-source requirements for BMP ligand expression in regulation of body size inCaenorhabditis elegans
Authors: SAVAGE-DUNN CATHY , YU LING , GILL KWESI , AWAN MUHAMMAD , FERNANDO THILINI
Published: December 2011

InCaenorhabditis elegans, the Bone Morphogenetic Protein (BMP)-related ligand Dpp- and BMP-like-1 (DBL-1) regulates body size by promoting the larval and adult growth of the large epidermal syncytium hyp7 without affecting cell division. This system provides an excellent model for dissecting the growth-promoting activities of BMP ligands, since in this context the growth and differentiation functions of DBL-1 are naturally uncoupled.dbl-1is expressed primarily in neurons and the DBL-1 ligand signals to its receptors and Smad signal transducers in the target tissue of the epidermis. The requirements constraining the source(s) of DBL-1, however, have not previously been investigated. We show here thatdbl-1expression requirements are strikingly relaxed. Expression in non-overlapping subsets of the endogenous expression pattern, as well as ectopic expression, can provide sufficient levels of activity for rescue of the small body size ofdbl-1mutants. By analysingdbl-1expression levels in transgenic strains with different degrees of rescue, we corroborate the model that DBL-1 is a dose-dependent regulator of growth. We conclude that, for body size regulation, the site of expression ofdbl-1is less important than the level of expression.
msechBari, a new MITE-like element inDrosophila sechelliarelated to theBaritransposon
Authors: DIAS ELAINE SILVA , CARARETO CLAUDIA MARCIA APARECIDA
Published: December 2011

A few occurrences ofminiatureinverted-repeattransposableelements (MITEs) have been reported in species of the genusDrosophila. Here, we describemsechBari, a MITE-like element inDrosophila sechellia. The element is short, approximately 90 bp in length, AT-rich and occurs in association with, or close to, genes, characteristics that are typical for MITEs. The identification was performedin silicousing the sequenced genome ofD. sechelliaand confirmed in a laboratory strain. This short element is related to theBari_DMtransposon ofDrosophila melanogaster, havingterminalinvertedrepeats (TIRs) of a similar length and a high identity with the full-lengthBari_DMelement. The estimated recent origin of the element and the homogeneity observed between copies found in the genome suggests thatmsechBaricould be active inD. sechellia.
A South Asianist's Response to Lieberman'sStrange Parallels
Authors: Sreenivasan Ramya
Published: December 2011

In this response to Victor Lieberman'sStrange Parallels: Southeast Asia in Global Context, c. 800–1830, I provide an outline of some significant trends in the historiography of early modern South Asia as it has evolved in the last decade or so. Both the period and the themes reviewed here reflect my own research interests. While Lieberman cites much of the research that I describe here in his chapter on South Asia inStrange Parallels, my reading of the significance of that work is somewhat at odds with his interpretation. This outline is primarily intended for non-South Asianist readers of the JAS, who might find this thematic treatment to be a useful point of entry to the field. It was this thematically oriented conversation that provoked the liveliest discussion during the colloquium at the Hawaii Conference on which this response is based.
Strange Parallels and the Big Picture: “Asia” Writ Large Over a Turbulent Millennium
Authors: Tagliacozzo Eric
Published: December 2011

Every now and again a book comes along that “shakes foundations”, as it were. Such volumes let us know that something novel has appeared on the scene, in terms of new ways of knowing the shape and landscape of the past, the great “undiscovered country” of the proverb.Strange Parallels– not one book, but two – is this kind of project. In an age of hyperbole it is easy to believe the breathless hype of publishers when they tell us, the reading public, that such work has arrived. Many of us often end up feeling deflated, though, when the volume finally gets to our desks. On occasion, though, such books do live up to the praise, and happily this is the case with Victor Lieberman's absorbing two volumes. Lieberman is a well-respected historian of Burma; in recent years, his tastes have been ranging further afield, however, as he has sought to connect Burma to larger stories and themes.Strange Parallelsis the result of that philandering eye, an occasion when infidelity of one's locus of choice cannot only be forgiven, but applauded because of the result. Lieberman did not just covet his neighbors in this exercise – Siam and Vietnam and the other polities of mainland Southeast Asia. He ended up coveting Eurasia, or the expanse of an entire continent. What happens when you marry a very specific area studies expertise to this kind of vastly expanded vision? What paradigms can be shifted, and what new patterns can be seen? Perhaps most importantly, what new things can be discerned about the “undiscovered country” of the past that previously were hidden, even tocognoscenti?
Comments on Victor Lieberman, Strange Parallels
Authors: Wills John E.
Published: December 2011

In the presence of such a powerhouse lineup of Asianists I think I will tiptoe off to the other end of Lieberman's Eurasia and presume on my unique qualifications in this company as having published over twenty pages for the general reader on the France of Louis XIV and fifteen on the Russia of Peter the Great. Also, I have a bee in my bonnet at the moment about how the world changed between 1770 and 1830, and will have most to say about what Lieberman offers on that period. I owe Jerry Bentley a review article on all this for the Journal of World History, because he got me a review copy of the large work of Jürgen Osterhammel, Die Verwandlung der Welt: Eine Geschichte des 19. Jahrhunderts. I also got hooked by listening in on a fine conference at the Clark Library in Los Angeles in 2008, which led to The Age of Revolutions in Global Context, edited by David Armitage and Sanjay Subrahmanyam. A less recent book which I think is an under-appreciated breakthrough for this effort is Chris Bayly's Imperial Meridian: The British Empire and the World, 1780–1830.
Environment, Law, and Democracy in India
Authors: Sivaramakrishnan K.
Published: December 2011

Some years ago, in his contribution to a collection of essays on the Supreme Court and the Indian Constitution, Pratap Bhanu Mehta emphasized the political significance of the Court, saying, “there is not a single important issue of political life in India that has not been, by accident or design, profoundly shaped by its interventions … the courts participate and collaborate in governing India” (Mehta 2006, 162). How exactly might this happen? In beginning to explore answers to this question, I want to focus on the formation of a distinct environmental jurisprudence and its relationship to the changing and dynamic qualities of a democratic polity in India. And in formulating my analysis I draw here on my current work on courts and the environment in India or how the environment came to be a legal object in India over the last century.
The dynamic architecture of photoreceptor ribbon synapses: Cytoskeletal, extracellular matrix, and intramembrane proteins
Authors: MERCER AARON J. , THORESON WALLACE B.
Published: December 2011

Rod and cone photoreceptors possess ribbon synapses that assist in the transmission of graded light responses to second-order bipolar and horizontal cells of the vertebrate retina. Proper functioning of the synapse requires the juxtaposition of presynaptic release sites immediately adjacent to postsynaptic receptors. In this review, we focus on the synaptic, cytoskeletal, and extracellular matrix proteins that help to organize photoreceptor ribbon synapses in the outer plexiform layer. We examine the proteins that foster the clustering of release proteins, calcium channels, and synaptic vesicles in the presynaptic terminals of photoreceptors adjacent to their postsynaptic contacts. Although many proteins interact with one another in the presynaptic terminal and synaptic cleft, these protein–protein interactions do not create a static and immutable structure. Instead, photoreceptor ribbon synapses are remarkably dynamic, exhibiting structural changes on both rapid and slow time scales.
Could cholinesterase inhibitors be harmful over the long term?
Authors: Schneider Lon S.
Published: December 2011

Given the rather modest clinical effects of cholinesterase inhibitors, an important question is: For how long should they be prescribed? The clinical trials that supported marketing of the drugs were only 3–6 months in duration. A couple of 12-month, placebo-controlled donepezil trials showed some advantage for Mini-Mental State Examination (MMSE) scores and maintaining a level of activities of daily living (ADL) function during that interval (Mohs et al., 2001; Winblad et al., 2001). The controversial AD2000 trial in the UK tended to show MMSE and ADL efficacy over at least two years (Courtney et al., 2004), but the authors questioned whether treatment was worthwhile or cost-effective.
The Shannon information content of hyperspectral shortwave cloud albedo measurements: Quantification and practical applications
Authors: Coddington Odele , Pilewskie Peter , Vukicevic Tomislava
Published: December 2011

The Shannon information content provides an objective measure of the information in a data set. In this paper, we quantify the information content of hyperspectral liquid water cloud measurements over a spectral range (300–2500 nm) representing approximately 95% of the total energy in the solar spectrum. We also use the Shannon information content to analyze the cloud retrieval wavelengths and weightings used by the Solar Spectral Flux Radiometer (SSFR) and to determine the cumulative information in the SSFR retrieval. These applications illustrate the utility of the Shannon information content in guiding the effective processing of hyperspectral data. Such efficiency is of growing importance considering the push toward spectrally resolved satellite measurements of reflected solar irradiance used to study climate.
Physical Activity and the Risk of Becoming Overweight or Obese in Middle‐Aged and Older Women
Authors: Britton Kathryn A. , Lee I‐Min , Wang Lu , Gaziano J. Michael , Manson JoAnn E. , Buring Julie E. , Sesso Howard D.
Published: December 2011

Although public health campaigns stress leisure time physical activity (LTPA) as essential for obesity prevention, few epidemiological studies have focused on the association of specific types and intensities of LTPA and the clinical endpoints of overweight and obesity. Therefore, we prospectively assessed whether moderate‐ and vigorous‐intensity as well as total LTPA were associated with the risk of becoming either overweight or obese using a prospective cohort design of 19,003 women enrolled in the Women's Health Study (WHS). Women reported their participation in walking and LTPA at baseline. During a median follow‐up of 11.6 years, 7,865 women became overweight or obese. In multivariable‐adjusted models that included demographic, lifestyle, and dietary factors, both vigorous‐intensity and total LTPA showed a modest inverse relationship with the development of overweight/obesity. The hazard ratios (HR) and 95% confidence interval (CI) for the highest categories of vigorous‐intensity LTPA (>2,000 kcal/week) and total LTPA (>3,000 kcal/week) compared with no LTPA were 0.79 (0.71–0.89) and 0.87 (0.78–0.96), respectively. In addition, a greater percentage of total LTPA spent performing vigorous intensity activities was associated with a lower risk of overweight/obesity (multivariable HR 0.93, 95% CI 0.87–0.98 for performing >50% compared with <50% of activity as vigorous). In conclusion, higher amounts of total LTPA should be encouraged to prevent obesity. Among those willing to participate in vigorous LTPA, and for whom such activities are not contraindicated, vigorous LPTA should be encouraged.
Alterations in the Common Pathway of Coagulation During Weight Loss Induced by Gastric Bypass in Severely Obese Patients
Authors: Pardina Eva , Ferrer Roser , Rivero Joaquín , Baena‐Fustegueras Juan A. , Lecube Albert , Fort Jose M. , Vargas Víctor , Catalán Roberto , Peinado‐Onsurbe Julia
Published: December 2011

The objective of this study was to establish the relationship between the plasminogen activator inhibitor‐1 (PAI‐1), antithrombin‐III (ATIII), fibrinogen, and white blood cell (WBC) levels in severely obese patients. We analyzed various plasma parameters implicated in the intrinsic and extrinsic coagulation pathway from 34 severely obese patients before and 1, 6, and 12 months after gastric bypass. In obese people, ATIII, fibrinogen, and WBC levels were in the upper limit of the normal range, and all were higher and significantly different from nonobese people. After bariatric surgery, the ATIII level continued to be high during the first month and increased until 12 months, while fibrinogen decreased only at that time. PAI‐1 plasma protein and PAI‐1 mRNA levels in liver and adipose tissue show similar profiles and had a strong positive correlation (r = 0.576, P = 0.0003 in liver; r = 0.433, P = 0.0004 in adipose tissue). They were higher in obese patients compared with nonobese control, but tended to recover normal values 1 month after surgery. Thus, the liver and adipose tissue could be an important source of PAI‐1 protein in plasma. Gastric bypass surgery leads to a normalization of the hematological profile and a decrease in PAI‐1 levels, which entails a decrease of risk for thromboembolism in severely obese.
Angiopoietin-like 4: a decade of research
Authors: Zhu Pengcheng , Goh Yan Yih , Chin Hwee Fang Alison , Kersten Sander , Tan Nguan Soon
Published: December 2011

The past decade has seen a rapid development and increasing recognition of ANGPTL4 (angiopoietin-like 4) as a remarkably multifaceted protein that is involved in many metabolic and non-metabolic conditions. ANGPTL4 has been recognised as a central player in various aspects of energy homoeostasis, at least in part, via the inhibitory interaction between the coiled-coil domain of ANGPTL4 and LPL (lipoprotein lipase). The fibrinogen-like domain of ANGPTL4 interacts and activates specific integrins to facilitate wound healing, modulates vascular permeability, and regulates ROS (reactive oxygen species) level to promote tumorigenesis. The present review summarizes these landmark findings about ANGPTL4 and highlights several important implications for future clinical practice. Importantly, these implications have also raised many questions that are in urgent need of further investigations, particularly the transcription regulation of ANGPTL4 expression, and the post-translation cleavage and modifications of ANGPTL4. The research findings over the past decade have laid the foundation for a better mechanistic understanding of the new scientific discoveries on the diverse roles of ANGPTL4.
Photoconductivity and trap-related decay in porous TiO2/ZnO nanocomposites
Authors: Wu Jun , Li Huayao , Liu Yuan , Xie Changsheng
Published: December 2011

Photoconductivity and trap-related decay were investigated in porous TiO2/ZnO nanocomposites. Photoconductivity responses of TiO2 and ZnO were completely different, which were attributed to electron-scavenging effect and hole trapping effect, respectively. When the mole ratio of TiO2:ZnO was from 9:1 to 6:4, the photoconductivity responses were consistent with TiO2. On the contrary, when the mole ratio of TiO2:ZnO was from 4:6 to 1:9, the photoconductivity responses were controlled by ZnO. Time constants were obtained by fitting the experiment data with an exponential function. We found that they tended to get larger with the percentage of ZnO while a turning point appeared at TiO2:ZnO = 1:9. The pattern was assigned to different carrier trapping mechanisms as well as carrier separation. Composition effect was defined by a quantitative formula to evaluate the recombination processes of composite materials. A mechanism was proposed to explain this phenomenon.
Gauge fields in spintronics
Authors: Fujita T. , Jalil M. B. A. , Tan S. G. , Murakami S.
Published: December 2011

We present an overview of gauge fields in spintronics, focusing on their origin and physical consequences. Important topics, such as the Berry gauge field associated with adiabatic quantum evolution as well as gauge fields arising from other non-adiabatic considerations, are discussed. We examine the appearance and effects of gauge fields across three spaces, namely real-space, momentum-space, and time, taking on a largely semiclassical approach. We seize the opportunity to study other “spin-like” systems, including graphene, topological insulators, magnonics, and photonics, which emphasize the ubiquity and importance of gauge fields. We aim to provide an intuitive and pedagogical insight into the role played by gauge fields in spin transport.
Exchange bias and enhanced coercivity in phase separated La0.45Sr0.55MnO3 and Pr0.55(Ca0.65S0.35)0.45MnO3 films
Authors: Kim Byeong-geon , Kumar Ashvani , Ki Sanghoon , Kim Sangwoo , Dho Joonghoe
Published: December 2011

An epitaxial La0.45Sr0.55MnO3 (LSMO) film, which has a paramagnetic-to-ferromagnetic transition at ∼260 K and a partial ferromagnetic-to-antiferromagnetic transition at ∼150 K upon cooling, was synthesized on (001) (La0.18Sr0.82)(Al0.59Ta0.41)O3 with pulsed laser deposition. The x-ray diffraction pattern showed interference fringes around the (002) LSMO peak, indicating a successful growth of a high quality and smooth film. When the LSMO film was cooled down in a magnetic field of 5 kOe, it exhibited a large exchange bias (HEX) of ∼490 Oe and an enhanced coercivity (HC) of ∼800 at 10 K, respectively. The observed exchange bias effect, which is associated with phase coexistence of the ferromagnetic (FM) and antiferromagnetic (AF) phases, displayed a distinctive training effect, which is probably due to a competing spin order at the boundary between the FM and AF phases. Similarly, we also observed a large exchange bias and enhanced coercivity in a phase separated Pr0.55(Ca0.65S0.35)0.45MnO3 film, which had simultaneous FM and AF transitions at ∼150 K. Our results show that the exchange bias effect can be induced even in single layer films with a magnetic phase coexistence state of FM and AF phases, which may be exploited as a very simple structure for spin-valve devices.
Atomic-scale structural evolution from disorder to order in an amorphous metal
Authors: Li F. , Liu X. J. , Hou H. Y. , Chen G. , Chen G. L.
Published: December 2011

In this paper, we performed molecular dynamics simulations to study the atomic-scale structural evolution from disorder to order during the isothermal annealing of an amorphous Ni. Three plateaus in the time dependent potential energy and mean square displacement (MSD) curves were observed, indicating that the atomic ordering process from amorphous to nanocrystalline Ni undergoes three distinct stages. The structural analyses reveal that the atomic structural evolution is associated with these three stages: Disordered atoms adjust their relative positions to form a one-dimensional (1D) periodic structure at the first stage, then form a 2D periodic structure at the second stage, and finally form a 3D periodic nanocrystal. Further analyses of potential energy and MSD difference and dynamics demonstrate that the structural change from the 2D to 3D structure is more difficult than that from the 1D to 2D structure, because both the 1D and 2D quasi-ordered structures belong to transition states and have similar structural features in nature. Our findings may provide new insights into the nanocrystallization of amorphous alloys and implications for producing nanostructured materials.
Misfit strain dependence of ferroelectric and piezoelectric properties of clamped (001) epitaxial Pb(Zr0.52,Ti0.48)O3 thin films
Authors: Nguyen Minh D. , Dekkers Matthijn , Houwman Evert , Steenwelle Ruud , Wan Xin , Roelofs Andreas , Schmitz-Kempen Thorsten , Rijnders Guus
Published: December 2011

A study on the effects of the residual strain in Pb(Zr0.52Ti0.48)O3 (PZT) thin films on the ferroelectric and piezoelectric properties is presented. Epitaxial (001)-oriented PZT thin film capacitors are sandwiched between SrRuO3 electrodes. The thin film stacks are grown on different substrate-buffer-layer combinations by pulsed laser deposition. Compressive or tensile strain caused by the difference in thermal expansion of the PZT film and substrate influences the ferroelectric and piezoelectric properties. All the PZT stacks show ferroelectric and piezoelectric behavior that is consistent with the theoretical model for strained thin films in the ferroelectric r-phase. We conclude that clamped (001) oriented Pb(Zr0.52Ti0.48)O3 thin films strained by the substrate always show rotation of the polarization vector.
Interfacial thermal resistance between metallic carbon nanotube and Cu substrate
Authors: Gao Feng , Qu Jianmin , Yao Matthew
Published: December 2011

A comprehensive model was developed to calculate the interfacial thermal resistance between a metallic carbon nanotube (CNT) and a Cu substrate. The new model accounts for both phonon-mediated and electron-mediated thermal transfer at the interface, as well as the effect of electron-phonon coupling within CNT and Cu. The phonon-mediated thermal transfer was simulated using the non-equilibrium molecular dynamics, while the electron-mediated thermal transfer was computed by the non-equilibrium Green’s function method in conjunction with the density function theory. The effect of electron-phonon coupling within Cu and CNT was investigated by using the kinetic theory. Our results show that (1) electron-phonon coupling within Cu and CNT contributes significantly to the overall thermal transfer across the CNT/Cu interface, and (2) contributions to the overall thermal conductance at the CNT/Cu interface from the electron-mediated thermal transfer are comparable to that from the phonon-mediated thermal transfer.
Electrical and optical properties of p-type InN
Authors: Mayer Marie A. , Choi Soojeong , Bierwagen Oliver , Smith Holland M. , Haller Eugene E. , Speck James S. , Walukiewicz Wladek
Published: December 2011

We have performed comprehensive studies of the optical, thermoelectric, and electrical properties of Mg doped InN with varying Mg doping levels and sample thicknesses. Room temperature photoluminescence spectra show a Mg acceptor related emission and the thermopower provides clear evidence for the presence of mobile holes. Although the effects of the hole transport are clearly observed in the temperature dependent electrical properties, the sign of the apparent Hall coefficient remains negative in all samples. We show that the standard model of two electrically well connected layers (n-type surface electron accumulation and p-type bulk) does not properly describe Hall effect in p-type InN.
Finite-size scaling relation of the Curie temperature in barium hexaferrite platelets
Authors: Wang Jun , Zhao Fan , Wu Wei , Zhao Guo-meng
Published: December 2011

High-temperature magnetic measurements were carried out on barium ferrite BaFe12O19 nanoparticles coated with amorphous silica. We find that the Curie temperature of this material decreases with decreasing particle size, in agreement with the finite-size scaling theory. In contrast to what one expects, the observed particle-size dependence of the Curie temperature does not follow a finite-size scaling relation for a zero-dimensional magnetic system. Instead, the data follow a finite-size scaling relation for a two-dimensional magnetic system with the scaling exponent ν = 0.78±0.06. The validity of the two-dimensional scaling relation in this material is due to the fact that the nanoparticles have a platelet-like shape.
The role of vicinal silicon surfaces in the formation of epitaxial twins during the growth of III-V thin films
Authors: Devenyi G. A. , Woo S. Y. , Ghanad-Tavakoli S. , Hughes R. A. , Kleiman R. N. , Botton G. A. , Preston J. S.
Published: December 2011

We examine the role of vicinal surface steps in the formation and propagation of twins during the growth of epitaxial III-V thin films (GaAs, InP, GaSb, AlSb) on silicon substrates. This is achieved through the combined use of two-dimensional X-ray diffraction and conventional transmission electron microscopy techniques, which allow for both a macro and nano/micro characterization of the material systems. Observed is a systematic suppression of twins formed opposite to the tilt direction of vicinal substrates through a process of step-flow overgrowth of nucleated twins, and an enhancement of twins toward the tilt direction when the fastest growth planes are aligned with the step-flow. These results indicate a probable path to the enhancement of the electronic mobility of lateral devices based on III-V semiconductors on silicon.
On the origin of enhanced photoconduction and photoluminescence from Au and Ti nanoparticles decorated aligned ZnO nanowire heterostructures
Authors: Dhara Soumen , Giri P. K.
Published: December 2011

We have investigated the mechanism of photoinduced charge transport and origin of enhanced PC and PL from Au and Ti NPs decorated vertically aligned ZnO NWs arrays. Uniform decoration of metal NPs on the surface of the ZnO NWs was confirmed by high resolution electron microscopy imaging. Absorption spectra also indicate the presence of metal NPs layer with different thicknesses. At a fixed bias, the dark current of the Au/ZnO heterostructures decreases with the increase of Au coverage, while the Ti/ZnO heterostructures show very high dark current. The photocurrent (PC) spectra show a strong peak at the UV region due to the band-edge absorption followed by generation of the photocarriers and two other peaks in the visible region. For the Au/ZnO heterostructures, the PC increases with increase of Au coverage up to a certain thickness and then decreased. On the other hand, the PC in Ti/ZnO heterostructures increases with the increase of the Ti coverage. The PL spectra for both the system are consistent with the respective PC spectra, which show significant improvement in the band-edge related UV emission and quenching of green emission. The Ti/ZnO heterostructures shows much faster photoresponse compared to the Au/ZnO heterostructures. The changes in the PC and PL spectra with the size of the metal NPs are studied systematically and explained. A model based on energy band alignment is proposed to explain the results.
Blueshift of bandgap energy and reduction of non-radiative defect density due to precise control of InAs-on-GaSb interface in type-II InAs/GaSb superlattice
Authors: Jasik A. , Sankowska I. , Pierścińska D. , Regiński K. , Pierściński K. , Kubacka-Traczyk J.
Published: December 2011

We have investigated the influence of As-soak parameters at InAs-on-GaSb interfaces on the structural and optical parameters of InAs/GaSb superlattices (SLs). The lattice-matched SLs were obtained for two sets of technological parameters. For a long As-soak time of 12.0 s and high V/III ratio of 10, the photoluminescence (PL) analysis indicates the presence of a non-radiative recombination channel. For a shorter time of 2.8 s and a reduced V/III ratio of 5.6, the PL excitation power dependence is close to that relevant for a clear excitonic recombination. The spectral blueshift of the bandgap energy of 23 meV was observed for SLs with GaAs-like interface thicknesses of 0.4 ML and 1.0 ML and other fixed parameters.
Anomalies of inverse direct current susceptibility in spin-chain compounds Ca3Co2-xMnxO6
Authors: Sheng S. S. , Ouyang Z. W. , Xia N. M. , Chen J. , Wu Y. Y. , Xia Z. C. , Li L.
Published: December 2011

Various types of anomalies of inverse dc susceptibility (H/M) have been observed in spin-chain compounds Ca3Co2-xMnxO6. For x = 1.0, the H/M curve exhibits a field-dependent downturn from the paramagnetic Curie-Weiss behavior, signaling the presence of a Griffiths-like cluster phase. A slight decrease of x leads to a rapid suppression of the Griffiths-like singularity, followed by an appearance of field-independent, non-Griffiths-like behavior at x = 0.92. This feature persists until x = 0.33, at and below which the H/M curve presents an unambiguous, field-independent upturn from the Curie-Weiss law. These Mn-doping-dependent anomalies of H/M curves are associated with complex competing magnetic interactions.
Room-temperature ground magnetic state of ɛ-Fe2O3: In-field Mössbauer spectroscopy evidence for collinear ferrimagnet
Authors: Tucek Jiri , Ohkoshi Shin-ichi , Zboril Radek
Published: December 2011

ɛ-Fe2O3 is a remarkable iron(III) oxide polymorph exhibiting a large room-temperature (RT) coercive field, coupled magnetoelectric properties, and millimeter-wave ferromagnetic resonance. Despite great application potential, its room-temperature ground magnetic state is still under scrutiny. Employing in-field 57Fe Mössbauer spectroscopy, we unambiguously demonstrate that at room temperature, ɛ-Fe2O3 behaves as a collinear ferrimagnet, hence excluding any canting of sublattice magnetizations. When exposed to an external magnetic field, ɛ-Fe2O3 can be modeled as a two-sublattice ferrimagnetic nanomaterial with the highest coercivity among all currently known ferrimagnetic (nano)materials.
Synthesis and characterization of titanium-alloyed hematite thin films for photoelectrochemical water splitting
Authors: Tang Houwen , Matin M. A. , Wang Heli , Deutsch Todd , Al-Jassim Mowafak , Turner John , Yan Yanfa
Published: December 2011

We have synthesized pure and Ti-alloyed hematite thin films on F doped SnO2 coated glass substrates by radio frequency magnetron co-sputtering of iron oxide and titanium targets in mixed Ar/O2 and mixed N2/O2 ambient. We found that the hematite films deposited in the N2/O2 ambient exhibit much poorer crystallinity than the films deposited in the Ar/O2 ambient. We determined that Ti alloying leads to increased electron carrier concentration and crystallinity, and reduced bandgaps. Moreover, Ti-alloyed hematite thin films exhibited improved photoelectrochemical performance as compared with the pure hematite films: The photocurrents were enhanced and the photocurrent onset shifted to less positive potentials.
High-resolution Fourier-transform extreme ultraviolet photoabsorption spectroscopy of 14N15N
Authors: Heays A. N. , Dickenson G. D. , Salumbides E. J. , de Oliveira N. , Joyeux D. , Nahon L. , Lewis B. R. , Ubachs W.
Published: December 2011

The first comprehensive high-resolution photoabsorption spectrum of 14N15N has been recorded using the Fourier-transform spectrometer attached to the Desirs beamline at the Soleil synchrotron. Observations are made in the extreme ultraviolet and span 100 000–109 000 cm−1 (100–91.7 nm). The observed absorption lines have been assigned to 25 bands and reduced to a set of transition energies, f values, and linewidths. This analysis has verified the predictions of a theoretical model of N2 that simulates its photoabsorption and photodissociation cross section by solution of an isotopomer independent formulation of the coupled-channel Schrödinger equation. The mass dependence of predissociation linewidths and oscillator strengths is clearly evident and many local perturbations of transition energies, strengths, and widths within individual rotational series have been observed.
Effects of chain stiffness and salt concentration on responses of polyelectrolyte brushes under external electric field
Authors: Cao Qianqian , Zuo Chuncheng , Li Lujuan , Yan Guang
Published: December 2011

We report a molecular dynamics study on non-equilibrium dynamics of polyelectrolyte brushes under external electric fields. In this work, the effects of chain stiffness and salt concentration on static and dynamic responses of the brushes are addressed in detail. Our simulations indicate that varying these parameters induce rich electro-responsive behavior of the brushes. The increase of salt concentration results in the enhancement of an opposite electric field formed by non-equilibrium distribution of cations and anions, which resists stretching or shrinkage of grafted chains. At strong positive electric fields, the flexible brushes are more sensitive to the change of salt concentration. When reversing the electric field, the stiff brushes undergo a conformational transition from collapse to complete stretching. At high salt concentrations, dynamic responsive magnitude of the brush thickness to added electric field is strongly reduced. It was found that the fall time for the stiff brush becomes much shorter than that for the flexible brush. Additionally, increasing ion concentration leads to an excess extension or shrinkage of flexible brushes. For strongly stiff brushes, such phenomenon occurs in the presence or absence of salt.
Interdisciplinary perspectives on the management of the unsettled baby: key strategies for improved outcomes
Authors: Douglas Pamela S. , Mares Renata E. , Hill Peter S.
Published: December 2011

The objectives of this study were to analyse the perspectives of key informants with clinical expertise in the care of unsettled babies in the first few months of life and their families, concerning changes required to improve outcomes. The research used a purposive selection strategy and thematic analysis of key informant interviews of 24 health professionals from 11 disciplines. Informants were selected for extensive experience in the management of unsettled babies and their families.Participants corroborated existing evidence that post-birth care in Australia is fragmented. All held the view that, first, early primary care intervention for unsettled infants and their families, and second, improved cross-professional communication, are vital if the burden of this problem to the infant, family and health system are to be minimised. There was consensus, third, that significant gaps exist in health professionals’ knowledge base and management behaviours.The development of education resources, best practice guidelines, shared assessment frameworks for primary care practitioners and strategies for improved cross-professional communication are necessary to improve the health outcomes and decrease the burden of this common yet complex post-birth problem.
Historical overview of church involvement in health and wellbeing in Australia: implications for health promotion partnerships
Authors: Ayton Darshini , Carey Gemma , Keleher Helen , Smith Ben
Published: December 2011

Health promotion practice requires partnerships with different sectors of society and at all levels of government to achieve health equity as the prerequisites for health include domains that exist outside of the health sphere. Therefore existing partnerships for health need to be strengthened and the potential for new partnerships must be considered in order to address health holistically. The literature base exploring the church as a partner and setting for health promotion is predominantly from the US and therefore there is a need for research exploring the opportunities and challenges of partnering with churches in the Australian context. This paper presents an historical overview of the involvement of churches and church affiliated organisations in health and welfare in Australia recognising that while some of the values, practices and beliefs of churches may have considerable synergies with health promotion, others may be sources of contention or difference.
The c-MYC oncoprotein, the NAMPT enzyme, the SIRT1-inhibitor DBC1, and the SIRT1 deacetylase form a positive feedback loop
Authors: Menssen Antje , Hydbring Per , Kapelle Karsten , Vervoorts Jörg , Diebold Joachim , Lüscher Bernhard , Larsson Lars-Gunnar , Hermeking Heiko
Published: December 2011

Silent information regulator 1 (SIRT1) represents an NAD
+
-dependent deacetylase that inhibits proapoptotic factors including p53. Here we determined whether SIRT1 is downstream of the prototypic c-
MYC
oncogene, which is activated in the majority of tumors. Elevated expression of c-MYC in human colorectal cancer correlated with increased SIRT1 protein levels. Activation of a conditional c-
MYC
allele induced increased levels of SIRT1 protein, NAD
+
, and nicotinamide-phosphoribosyltransferase (
NAMPT
) mRNA in several cell types. This increase in SIRT1 required the induction of the
NAMPT
gene by c-MYC. NAMPT is the rate-limiting enzyme of the NAD
+
salvage pathway and enhances SIRT1 activity by increasing the amount of NAD
+
. c-MYC also contributed to SIRT1 activation by sequestering the SIRT1 inhibitor deleted in breast cancer 1 (DBC1) from the SIRT1 protein. In primary human fibroblasts previously immortalized by introduction of c-MYC, down-regulation of SIRT1 induced senescence and apoptosis. In various cell lines inactivation of SIRT1 by RNA interference, chemical inhibitors, or ectopic DBC1 enhanced c-MYC-induced apoptosis. Furthermore, SIRT1 directly bound to and deacetylated c-MYC. Enforced SIRT1 expression increased and depletion/inhibition of SIRT1 reduced c-MYC stability. Depletion/inhibition of SIRT1 correlated with reduced lysine 63-linked polyubiquitination of c-Myc, which presumably destabilizes c-MYC by supporting degradative lysine 48-linked polyubiquitination. Moreover, SIRT1 enhanced the transcriptional activity of c-MYC. Taken together, these results show that c-MYC activates SIRT1, which in turn promotes c-MYC function. Furthermore, SIRT1 suppressed cellular senescence in cells with deregulated c-MYC expression and also inhibited c-MYC–induced apoptosis. Constitutive activation of this positive feedback loop may contribute to the development and maintenance of tumors in the context of deregulated c-MYC.
A role for neuronal cAMP responsive-element binding (CREB)-1 in brain responses to calorie restriction
Authors: Fusco Salvatore , Ripoli Cristian , Podda Maria Vittoria , Ranieri Sofia Chiatamone , Leone Lucia , Toietta Gabriele , McBurney Michael W. , Schütz Günther , Riccio Antonella , Grassi Claudio , Galeotti Tommaso , Pani Giovambattista
Published: December 2011

Calorie restriction delays brain senescence and prevents neurodegeneration, but critical regulators of these beneficial responses other than the NAD
+
-dependent histone deacetylase Sirtuin-1 (Sirt-1) are unknown. We report that effects of calorie restriction on neuronal plasticity, memory and social behavior are abolished in mice lacking cAMP responsive-element binding (CREB)-1 in the forebrain. Moreover, CREB deficiency drastically reduces the expression of Sirt-1 and the induction of genes relevant to neuronal metabolism and survival in the cortex and hippocampus of dietary-restricted animals. Biochemical studies reveal a complex interplay between CREB and Sirt-1: CREB directly regulates the transcription of the sirtuin in neuronal cells by binding to Sirt-1 chromatin; Sirt-1, in turn, is recruited by CREB to DNA and promotes CREB-dependent expression of target gene peroxisome proliferator-activated receptor-γ coactivator-1α and neuronal NO Synthase. Accordingly, expression of these CREB targets is markedly reduced in the brain of Sirt KO mice that are, like CREB-deficient mice, poorly responsive to calorie restriction. Thus, the above circuitry, modulated by nutrient availability, links energy metabolism with neurotrophin signaling, participates in brain adaptation to nutrient restriction, and is potentially relevant to accelerated brain aging by overnutrition and diabetes.
Tumor suppression by cell competition through regulation of the Hippo pathway
Authors: Chen Chiao-Lin , Schroeder Molly C. , Kango-Singh Madhuri , Tao Chunyao , Halder Georg
Published: December 2011

Homeostatic mechanisms can eliminate abnormal cells to prevent diseases such as cancer. However, the underlying mechanisms of this surveillance are poorly understood. Here we investigated how clones of cells mutant for the neoplastic tumor suppressor gene
scribble
(
scrib
) are eliminated from
Drosophila
imaginal discs. When all cells in imaginal discs are mutant for
scrib,
they hyperactivate the Hippo pathway effector Yorkie (Yki), which drives growth of the discs into large neoplastic masses. Strikingly, when discs also contain normal cells, the
scrib
−
cells do not overproliferate and eventually undergo apoptosis through JNK-dependent mechanisms. However, induction of apoptosis does not explain how
scrib
−
cells are prevented from overproliferating. We report that cell competition between
scrib
−
and wild-type cells prevents hyperproliferation by suppressing Yki activity in
scrib
−
cells. Suppressing Yki activation is critical for
scrib
−
clone elimination by cell competition, and experimental elevation of Yki activity in
scrib
−
cells is sufficient to fuel their neoplastic growth. Thus, cell competition acts as a tumor-suppressing mechanism by regulating the Hippo pathway in
scrib
−
cells.