bluuebunny/crossref_metadata_2025 huggingface dataset:
Using time-frequency analysis to determine time-resolved detonation velocity with microwave interferometry
Authors: Kittell David E. , Mares Jesus O. , Son Steven F.
Published: April 2015

Two time-frequency analysis methods based on the short-time Fourier transform (STFT) and continuous wavelet transform (CWT) were used to determine time-resolved detonation velocities with microwave interferometry (MI). The results were directly compared to well-established analysis techniques consisting of a peak-picking routine as well as a phase unwrapping method (i.e., quadrature analysis). The comparison is conducted on experimental data consisting of transient detonation phenomena observed in triaminotrinitrobenzene and ammonium nitrate-urea explosives, representing high and low quality MI signals, respectively. Time-frequency analysis proved much more capable of extracting useful and highly resolved velocity information from low quality signals than the phase unwrapping and peak-picking methods. Additionally, control of the time-frequency methods is mainly constrained to a single parameter which allows for a highly unbiased analysis method to extract velocity information. In contrast, the phase unwrapping technique introduces user based variability while the peak-picking technique does not achieve a highly resolved velocity result. Both STFT and CWT methods are proposed as improved additions to the analysis methods applied to MI detonation experiments, and may be useful in similar applications.
Self-organization of pulsing and bursting in a CO2 laser with opto-electronic feedback
Authors: Freire Joana G. , Meucci Riccardo , Arecchi Fortunato Tito , Gallas Jason A. C.
Published: April 2015

We report a detailed investigation of the stability of a CO2 laser with feedback as described by a six-dimensional rate-equations model which provides satisfactory agreement between numerical and experimental results. We focus on experimentally accessible parameters, like bias voltage, feedback gain, and the bandwidth of the feedback loop. The impact of decay rates and parameters controlling cavity losses are also investigated as well as control planes which imply changes of the laser physical medium. For several parameter combinations, we report stability diagrams detailing how laser spiking and bursting is organized over extended intervals. Laser pulsations are shown to emerge organized in several hitherto unseen regular and irregular phases and to exhibit a much richer and complex range of behaviors than described thus far. A significant observation is that qualitatively similar organization of laser spiking and bursting can be obtained by tuning rather distinct control parameters, suggesting the existence of unexpected symmetries in the laser control space.
From globally coupled maps to complex-systems biology
Authors: Kaneko Kunihiko
Published: April 2015

Studies of globally coupled maps, introduced as a network of chaotic dynamics, are briefly reviewed with an emphasis on novel concepts therein, which are universal in high-dimensional dynamical systems. They include clustering of synchronized oscillations, hierarchical clustering, chimera of synchronization and desynchronization, partition complexity, prevalence of Milnor attractors, chaotic itinerancy, and collective chaos. The degrees of freedom necessary for high dimensionality are proposed to equal the number in which the combinatorial exceeds the exponential. Future analysis of high-dimensional dynamical systems with regard to complex-systems biology is briefly discussed.
Computation of shear viscosity of colloidal suspensions by SRD-MD
Authors: Laganapan A. M. K. , Videcoq A. , Bienia M. , Ala-Nissila T. , Bochicchio D. , Ferrando R.
Published: April 2015

The behaviour of sheared colloidal suspensions with full hydrodynamic interactions (HIs) is numerically studied. To this end, we use the hybrid stochastic rotation dynamics-molecular dynamics (SRD-MD) method. The shear viscosity of colloidal suspensions is computed for different volume fractions, both for dilute and concentrated cases. We verify that HIs help in the collisions and the streaming of colloidal particles, thereby increasing the overall shear viscosity of the suspension. Our results show a good agreement with known experimental, theoretical, and numerical studies. This work demonstrates the ability of SRD-MD to successfully simulate transport coefficients that require correct modelling of HIs.
Free-energy functional method for inverse problem of self assembly
Authors: Torikai Masashi
Published: April 2015

A new theoretical approach is described for the inverse self-assembly problem, i.e., the reconstruction of the interparticle interaction from a given structure. This theory is based on the variational principle for the functional that is constructed from a free energy functional in combination with Percus’s approach [J. Percus, Phys. Rev. Lett. 8, 462 (1962)]. In this theory, the interparticle interaction potential for the given structure is obtained as the function that maximizes the functional. As test cases, the interparticle potentials for two-dimensional crystals, such as square, honeycomb, and kagome lattices, are predicted by this theory. The formation of each target lattice from an initial random particle configuration in Monte Carlo simulations with the predicted interparticle interaction indicates that the theory is successfully applied to the test cases.
Modeling of stretched-exponential and stretched-hyperbola time dependence of threshold voltage shift in thin-film transistors
Authors: Jung Taeho
Published: April 2015

To gain insight into the underlying properties of the well-known stretched-exponential and stretched-hyperbola time dependence models, I propose a numerical method to study threshold voltage (Vt) shift caused by both defect creation and charge trapping using a generic kinetic equation. It is shown that during the early phase of Vt shift, the time evolution of the shift is determined by the density of barrier states or trap sites which exponentially increases with barrier energy or trap location from a channel and is characterized by the dispersion parameter β in the models. The later phase is effectively determined by reaction rates in the kinetic equation in addition to β. In the case of the stretched-hyperbola model, the later phase is distinguished by the backward reaction and characterized by the fitting parameter α in the model. It is shown that Vt shifts in which backward reactions dominate during the later phase are represented by the stretched-exponential model and the rest is represented by the stretched-hyperbola model. The proposed method is also used to analyze the logarithmic time dependence model and cases when two instances of the models coexist in order to show that it is useful to study Vt shift of arbitrary shape. It is concluded that the shape of Vt shift is determined by the reaction rates and the density of barrier states or trap sites.
Coupled ridge waveguide distributed feedback quantum cascade laser arrays
Authors: Liu Ying-Hui , Zhang Jin-Chuan , Yan Fang-Liang , Liu Feng-Qi , Zhuo Ning , Wang Li-Jun , Liu Jun-Qi , Wang Zhan-Guo
Published: April 2015

A coupled ridge waveguide quantum cascade laser (QCL) array consisting of fifteen elements with parallel integration was presented. In-phase fundamental mode operation in each element is secured by both the index-guided nature of the ridge and delicate loss management by properly designed geometries of the ridges and interspaces. Single-lobe lateral far-field with a nearly diffraction limited beam pattern was obtained. By incorporating a one-dimensional buried distributed feedback grating, the in-phase-operating coupled ridge waveguide QCL design provides an efficient solution to obtaining high output power and stable single longitudinal mode emission. The simplicity of this structure and fabrication process makes this approach attractive to many practical applications.
Communication: Practical and rigorous reduction of the many-electron quantum mechanical Coulomb problem to O(N2/3) storage
Authors: Pederson Mark R.
Published: April 2015

It is tacitly accepted that, for practical basis sets consisting of N functions, solution of the two-electron Coulomb problem in quantum mechanics requires storage of O(N4) integrals in the small N limit. For localized functions, in the large N limit, or for planewaves, due to closure, the storage can be reduced to O(N2) integrals. Here, it is shown that the storage can be further reduced to O(N2/3) for separable basis functions. A practical algorithm, that uses standard one-dimensional Gaussian-quadrature sums, is demonstrated. The resulting algorithm allows for the simultaneous storage, or fast reconstruction, of any two-electron Coulomb integral required for a many-electron calculation on processors with limited memory and disk space. For example, for calculations involving a basis of 9171 planewaves, the memory required to effectively store all Coulomb integrals decreases from 2.8 Gbytes to less than 2.4 Mbytes.
Charge transport of graphene ferromagnetic-insulator-superconductor junction with pairing state of broken time reversal symmetry
Authors: Hajati Yaser
Published: April 2015

We investigate the charge transport through a graphene-based ferromagnetic-insulator-superconductor junction with a broken time reversal symmetry (BTRS) of dx2−y2 + is and dx2−y2 + idxy superconductor using the extended Blonder-Tinkham-Klapwijk formalism. Our analysis have shown several charateristics in this junction, providing a useful probe to understand the role of the order parameter symmetry in the superconductivity. We find that the presence of the BTRS (X) state in the superconductor region has a strong effect on the tunneling conductance curves which leads to a decrease in the height of the zero-bias conductance peak (ZBCP). In particular, we show that the magnitude of the superconducting proximity effect depends to a great extent on X and by increasing X, the zero-bias charge conductance oscillations with respect to the rotation angle β are suppressed. In addition, we find that at the maximum rotation angle β = π/4, introducing BTRS in the FIS junction causes oscillatory behavior of the zero-bias charge conductance with the barrier strength (χG) by a period of π and by approaching the X to 1, the amplitude of charge conductance oscillations increases. This behavior is drastically different from none BTRS similar graphene junctions. At last, we suggest an experimental setup for verifying our predicted effects.
Towards a Global Genealogy of Biopolitics: Race, Colonialism, and Biometrics beyond Europe
Authors: Nishiyama Hidefumi
Published: April 2015

This paper examines, at the global scale, the biopolitical strategy of racism that Foucault articulated in the context of 19th-century Europe. Through my historical analysis both of the emergent notion of race and of biometric production of racial knowledge during Japanese colonialism, I endeavour to delineate a circulation of a political rationality of modern racism, which became globally generalised and constitutive of the formation of a non-Western nation-state. I argue that this emergence of global biopolitics, however, should not simply be reduced to a unitary operation but needs to be understood as the process of multiplication that reveals both the continuity and the contingency of the biopolitical strategy of racism in relation to particular spatiotemporal configurations. Furthermore, through an archaeological reading of Foucault on modern racism, I will suggest that Foucault's Society Must be Defended, albeit arguably underdeveloped in its geographical scope of analysis, can shed light on the operation of biopolitics and modern racism beyond the history of Europe.
Calcium : magnesium ratio affects environmental stress sensitivity in the serpentine-endemic Alyssum inflatum (Brassicaceae)
Authors: Ghasemi Rasoul , Chavoshi Zohreh Zare , Boyd Robert S. , Rajakaruna Nishanta
Published: April 2015

Plants endemic to serpentine soils are adapted to harsh environmental conditions typical of those soils, particularly, low (<1) calcium (Ca) : magnesium (Mg) ratios. We compared survival of two perennial Alyssum species native to Iran under experimental manipulations of Ca : Mg ratio, including when Ca : Mg ratio was varied under conditions of high ammonium concentration and heat stress. Alyssum inflatum is a serpentine endemic capable of nickel (Ni) hyperaccumulation, whereas A. lanceolatum is found on non-serpentine soils and is not known to hyperaccumulate Ni. We grew plants of both species under four Ca : Mg ratios (0.4, 2, 20, 40) and tested survival when plants were exposed to elevated ammonium levels (0, 1 and 4 mM) and heat stress (control conditions vs a 5-h 36°C treatment daily for 5 days). Alyssum lanceolatum was more tolerant of Ca : Mg ratio variation (100% survival in all treatments), whereas A. inflatum survival was maximum at Ca : Mg = 2, reduced at Ca : Mg = 0.4, and very low for Ca : Mg ratios of 20 and 40. Alyssum lanceolatum also tolerated ammonium and heat stress, whereas survival of A. inflatum declined at higher Ca : Mg ratios when subjected to both stresses. We conclude that at higher Ca : Mg ratios, the serpentine endemic has reduced tolerance for these environmental stresses and may be more susceptible to human-driven climate change-associated stressors than the non-serpentine species.
Effect of Tides, River Flow, and Gate Operations on Entrainment of Juvenile Salmon into the Interior Sacramento–San Joaquin River Delta
Authors: Perry Russell W. , Brandes Patricia L. , Burau Jon R. , Sandstrom Philip T. , Skalski John R.
Published: April 2015

Juvenile Chinook Salmon Oncorhynchus tshawytscha emigrating from natal tributaries of the Sacramento River, California, must negotiate the Sacramento–San Joaquin River Delta (hereafter, the Delta), a complex network of natural and man‐made channels linking the Sacramento River with San Francisco Bay. Fish that enter the interior and southern Delta—the region to the south of the Sacramento River where water pumping stations are located—survive at a lower rate than fish that use alternative migration routes. Consequently, total survival decreases as the fraction of the population entering the interior Delta increases, thus spurring management actions to reduce the proportion of fish that are entrained into the interior Delta. To better inform management actions, we modeled entrainment probability as a function of hydrodynamic variables. We fitted alternative entrainment models to telemetry data that identified when tagged fish in the Sacramento River entered two river channels leading to the interior Delta (Georgiana Slough and the gated Delta Cross Channel). We found that the probability of entrainment into the interior Delta through both channels depended strongly on the river flow and tidal stage at the time of fish arrival at the river junction. Fish that arrived during ebb tides had a low entrainment probability, whereas fish that arrived during flood tides (i.e., when the river's flow was reversed) had a high probability of entering the interior Delta. We coupled our entrainment model with a flow simulation model to evaluate the effect of nighttime closures of the Delta Cross Channel gates on the daily probability of fish entrainment into the interior Delta. Relative to 24‐h gate closures, nighttime closures increased daily entrainment probability by 3 percentage points on average if fish arrived at the river junction uniformly throughout the day and by only 1.3 percentage points if 85% of fish arrived at night. We illustrate how our model can be used to evaluate the effects of alternative water management actions on fish entrainment into the interior Delta.
The reform–underdevelopmentalism nexus in a dependent state: a case study of the Nigerian banking sector reforms
Authors: Ebohon Sylvanus I.
Published: April 2015

This paper attempts to capture the link between reform and development of the Nigerian banking sector. As a single-resource economy, Nigeria's development is embedded in a dependence framework in which commission forms the basis of primitive accumulation. The analysis, which is based on empirical evidence from primary and secondary sources, shows capital flight, toxic assets, abnormal profitability and margin banking in the Nigerian reform. It argues that within the framework of dependence reformism tied to metropolitan technology, reforms cannot produce mega banks. Backward integration offers Nigeria the hope for transiting from economically underdeveloped south to economically developed north.
Isolation and characterization of bacterial strains with the ability to utilize high concentrations of levulinic acid, a platform chemical from inedible biomass
Authors: Habe Hiroshi , Sato Shun , Morita Tomotake , Fukuoka Tokuma , Kirimura Kohtaro , Kitamoto Dai
Published: April 2015

Nineteen levulinic acid (LA)-utilizing bacteria were isolated from environmental samples. Following examination of the use of 80 g/L LA by some isolated strains, Brevibacterium epidermidis LA39–2 consumed 62.6 g/L LA following 8 days incubation. The strain also utilized both 90 and 100 g/L LA, with consumption ratio of 84.3 and 53.3%, respectively, after 10 days incubation.
The effects of static stretching on speed and agility: One or multiple repetition protocols?
Authors: Avloniti Alexandra , Chatzinikolaou Athanasios , Fatouros Ioannis G. , Protopapa Maria , Athanailidis Ioannis , Avloniti Christina , Leontsini Diamanda , Mavropalias George , Jamurtas Athanasios Z.
Published: April 2015

Although static stretching (SS) is utilized during warm‐up before training and competition, the results about its effects on performance remain controversial. We examined whether performing a stretch of short‐to‐moderate duration (<60 sec) in a single repetition produces a similar or different effect on speed and agility performance from the effect which is produced while performing the same stretch in multiple repetitions of the same total duration. According to a repeated measurement design, 40 trained males were randomly assigned to either (1) a single repetition group or (2) a multiple repetition group. The participants in each group performed five trials: a control trial (no stretches were performed) and four experimental trials of SS protocols consisting of five exercises performed at either 20 sec (2 × 10 in the second group), 30 sec (3 × 10 in the second group), 40 sec (4 × 10 in the second group) or 60 sec (6 × 10 in the second group) of total duration. A two‐way repeated measures analysis of variance showed that the participants in both group improved their speed performance in response to the 20‐sec trial, whereas agility remained unaffected. Data analysis also revealed that the repetition number did not affect speed and agility performance. These data suggest that SS of short duration (<30 sec) may actually improve acute speed performance, whereas SS of moderate duration may not hamper speed and agility performance. Moreover, the effects of SS protocols are related to the total duration of each exercise and not to the number of repetitions in which each exercise is performed.
Simulating the Trophic Impacts of Fishery Policy Options on the West Florida Shelf Using Ecopath with Ecosim
Authors: Chagaris David D. , Mahmoudi Behzad , Walters Carl J. , Allen Micheal S.
Published: April 2015

The recovery of several top predators in the Gulf of Mexico is likely to increase predation on and competition with other target and nontarget species, possibly causing the abundance of those species to decline. While changes are taking place at the upper trophic levels, exploitation of prey species and climate change are altering productivity at the lower levels. An Ecopath with Ecosim model was developed to simulate the ecosystem impacts of Reef Fish Fishery Management Plan Amendment 30B (which aims to rebuild Gag Mycteroperca microlepis) and Amendment 31 (which reduces effort in the longline fishery). We also evaluated the impact of a hypothetical increase in the exploitation of baitfish and future changes to phytoplankton productivity. The model predicted that rebuilding Gag will cause the biomass of Black Sea Bass Centropristis striata to be 20% lower than it is now and those of Black Grouper M. bonaci, King Mackerel Scomberomorus cavalla, and other shallow-water groupers to be 5–10% lower. Reducing effort in the longline fishery will lead to biomass declines for Black Sea Bass (13%) and Vermilion Snapper Rhomboplites aurorubens (7%). Harvesting baitfish at historically high levels caused the biomass of Red Snapper Lutjanus campechanus, Vermilion Snapper, Greater Amberjack Seriola dumerili, King Mackerel, and numerous species of dolphins and seabirds to be 5–12% lower after 20 years, while biomass increased for species whose diet consists of benthic-associated prey. This paper demonstrates that ecosystem models can be used to quantify the potential ecological impacts of management goals and that the predictions of such models should be considered alongside stock projections from single-species models that assume a constant environment. We intend for this research effort to lead to a more focused and coherent strategy for ecosystem-based fishery management in the Gulf of Mexico.

Received January 30, 2014; accepted September 9, 2014
Invariant polynomials on tensors under the action of a product of orthogonal groups
Authors: Williams Lauren
Published: April 2015

LetKKbe the productOn1×On2×⋯×OnrO_{n_1}\times O_{n_2} \times \cdots \times O_{n_r}of orthogonal groups. LetV=⨂i=1rCniV = \bigotimes _{i = 1}^r \mathbb {C}^{n_i}, therr-fold tensor product of defining representations of each orthogonal factor. We compute a stable formula for the dimension of theKK-invariant algebra of degreeddhomogeneous polynomial functions onVV. To accomplish this, we compute a formula for the number of matchings which commute with a fixed permutation. Finally, we provide formulas for the invariants and describe a bijection between a basis for the space of invariants and the isomorphism classes of certainrr-regular graphs onddvertices, as well as a method of associating each invariant to other combinatorial settings such as phylogenetic trees.
The adiabatic limit of wave map flow on a two-torus
Authors: Speight J.
Published: April 2015

TheS2S^2valued wave map flow on a Lorentzian domainR×Σ\mathbb {R}\times \Sigma, whereΣ\Sigmais any flat two-torus, is studied. The Cauchy problem with initial data tangent to the moduli space of holomorphic mapsΣ→S2\Sigma \rightarrow S^2is considered, in the limit of small initial velocity. It is proved that wave maps, in this limit, converge in a precise sense to geodesics in the moduli space of holomorphic maps, with respect to theL2L^2metric. This establishes, in a rigorous setting, a long-standing informal conjecture of Ward.
PROVEAN web server: a tool to predict the functional effect of amino acid substitutions and indels
Authors: Choi Yongwook , Chan Agnes P.
Published: April 2015

Summary: We present a web server to predict the functional effect of single or multiple amino acid substitutions, insertions and deletions using the prediction tool PROVEAN. The server provides rapid analysis of protein variants from any organisms, and also supports high-throughput analysis for human and mouse variants at both the genomic and protein levels.

Availability and implementation: The web server is freely available and open to all users with no login requirements at http://provean.jcvi.org.

Contact:  achan@jcvi.org

Supplementary information:  Supplementary data are available at Bioinformatics online.
Early Career Experience of Pediatric Orthopaedic Fellows: What to Expect and Need for Their Services
Authors: Glotzbecker Michael P. , Shore Benjamin J. , Fletcher Nicholas D. , Larson A. Noelle , Hydorn Christopher R. , Sawyer Jeffery R.
Published: April 2015

Introduction:

A dramatic increase in the number of pediatric orthopaedic fellows being trained has led to concerns that there may be an oversupply of pediatric orthopaedists. The purpose of this study was to determine whether this perception is accurate and whether the practice expectations of recent pediatric fellowship graduates are being met by surveying recent pediatric fellowship graduates about their early practice experiences.

Methods:

A 36-question survey approved by the Pediatric Orthopaedic Society of North America (POSNA) leadership was electronically distributed to 120 recent graduates of pediatric orthopaedic fellowships; 81 responses were ultimately obtained (67.5% response rate).

Results:

Almost all (91%) of the respondents were very or extremely satisfied with their fellowship experience. Half of the respondents had at least 1 job offer before they entered their fellowships. After completion of fellowships, 35% received 1 job offer and 62.5% received ≥2 job offers; only 2.5% did not receive a job offer. Most reported a practice consisting almost entirely of pediatric orthopaedics, and 93.5% thought this was in line with their expectations; 87% indicated satisfaction with their current volume of pediatric orthopaedics, and 85% with the complexity of their pediatric orthopaedic cases. Despite the high employment percentages and satisfaction with practice profiles, nearly a third (28%) of respondents replied that too many pediatric orthopaedists are being trained.

Conclusions:

Positive messages from this survey include the satisfaction of graduates with their fellowship training, the high percentage of graduates who readily found employment, and the satisfaction of graduates with their current practice environments; this indicates that the pediatric orthopaedic job environment is not completely saturated and there are continued opportunities for graduating pediatric fellows despite the increased number of fellows being trained. Although not determined by this study, it may be that the stable demand for pediatric orthopaedic services is being driven by the expansion of the scope of practice as well as subspecialization within the practice of pediatric orthopaedics.
Disproportionate Participation of Males and Females in Academic Pediatric Orthopaedics: An Analysis of Abstract Authorship at POSNA 2009-2013
Authors: Sharkey Melinda S. , Feinn Richard S. , Tate Victoria V. , Carter Cordelia W. , Cassese Todd T.
Published: April 2015

Background:

Despite increasing numbers of female orthopaedic surgeons, we hypothesized that women were not actively participating at national and international meetings in numbers proportional to their membership.

Methods:

A retrospective review of the 2009-2013 POSNA Annual Meeting Final Programs was performed. The following information was recorded for all members: name, sex, membership level, years of membership, and if the individual was an author on at least 1 abstract. To compare proportion of abstract authorship between sexes across years, while controlling for years of membership, general estimating equations with a binomial model and logit link were used. The study population was limited to candidate and active POSNA members only, as this group represents the most active practicing pediatric orthopaedic surgeons.

Results:

Over the 5-year period studied, females comprised 16.6% (204/1227) of the total POSNA membership and 20.9% (184/880) of members at candidate and active status. The percentage of females with candidate or active member status in POSNA who had at least 1 abstract presentation during the 5 years was 37% and this was significantly lower (P=0.003) than the percentage of men (49%) who presented at least 1 abstract. Analysis across the 5 years showed a consistent difference between the sexes with no trend of convergence in abstract rates (P=0.65). Controlling for years membership, female members still presented abstracts at lower rates than their male colleagues (P=0.002).

Conclusions:

Female members of POSNA, in the most active part of their careers, participated at significantly lower rates than their male peers as accepted abstract authors for the 2009-2013 POSNA meetings than would be expected for their proportional size of total membership.
Orbital Mucormycosis Following Periorbital Cutaneous Infection
Authors: Chahal Harinder S. , Abgaryan Narine , Lakshminarayanan Renuka , Glover A. Tyrone
Published: April 2015

Mucormycosis is an aggressive fungal infection characterized by rapidly progressive angioinvasion and tissue necrosis. When present in the orbit, mucormycosis can quickly lead to permanent visual loss and potentially fatal cerebral extension. Orbital involvement is almost universally preceded by infection of the paranasal sinuses. Secondary infection of the orbit via direct extension of neighboring cutaneous mucormycosis has not been previously described. The authors present a case of cutaneous mucormycosis with orbital extension in a poorly controlled diabetic patient.
Low-Molecular-Weight Heparins as Immunomodulators in Dermatology Practice
Authors: Solak Berna
Published: April 2015

Low-molecular-weight heparins (LMWHs) have some effects on cell proliferation and inflammation beyond mere anticoagulation. They have been tried on treatment of a few dermatological disorders such as lichen planus, skin wound healing, recurrent aphtous stomatitis, chronic urticaria, and contact hypersensitivity. LMWHs are generally well-tolerated drugs, rarely can lead to severe reactions. In this article, we will review the novel indications of LMWHs in dermatology practice and common skin reactions associated with their use.
Accountability: Challenges to Getting It Right
Authors: Duthie Elizabeth Ann
Published: April 2015

Patient safety experts debated accountability in health care at the 2014 annual National Patient Safety Foundation Congress. The debate reflected the struggles organizations are facing with ensuring a responsible workforce committed to patient safety versus the need to redesign flawed systems that are error prone. The question, “is it the systems or the individual?” was at issue. This article proposes that it is the wrong question, and the failure to apply patient safety science in clinical practice is contributing to the ambiguity fueling the debate. To transform accountability from a source of confusion to a powerful tool for fulfilling health care's fiduciary responsibility to protect patients from harm, we need to reframe our approach. This article presents the science and strategies to create clarity that will redirect the dialogue from a debate in which accountability resides to one about learning for improvement when adverse events occur.
Adaptive evolution of anti-viral siRNAi genes in bumblebees
Authors: Helbing Sophie , Lattorff H. Michael G.
Published: April 2015

The high density of frequently interacting and closely related individuals in social insects enhance pathogen transmission and establishment within colonies. Group-mediated behavior supporting immune defenses tend to decrease selection acting on immune genes. Along with low effective population sizes this will result in relaxed constraint and rapid evolution of genes of the immune system. Here we show that sociality is the main driver of selection in antiviral siRNAi genes in social bumblebees compared to their socially parasitic cuckoo bumblebees that lack a worker caste. RNAi genes show frequent positive selection at the codon level additionally supported by the occurrence of parallel evolution and their evolutionary rate is linked to their pathway specific position with genes directly interacting with viruses showing the highest rates of molecular evolution. We suggest that indeed higher pathogen load in social insects drive adaptive evolution of immune genes, if not compensated by behavior.
TheIn situgrowth of Nanostructures on Surfaces (INS) endstation of the ESRF BM32 beamline: a combined UHV–CVD and MBE reactor forin situX-ray scattering investigations of growing nanoparticles and semiconductor nanowires
Authors: Cantelli V. , Geaymond O. , Ulrich O. , Zhou T. , Blanc N. , Renaud G.
Published: April 2015

This paper presents the upgraded `In situ growth of Nanoscructures on Surfaces' (INS) endstation of the InterFace beamline IF-BM32 at the European Synchrotron Radiation Facility (ESRF). This instrument, originally designed to investigate the structure of clean surfaces/interfaces/thin-films by surface X-ray diffraction, has been further developed to investigate the formation and evolution of nanostructures by combining small- and wide-angle X-ray scattering methodologies,i.e.grazing-incidence small-angle X-ray scattering (GISAXS) and grazing-incidence X-ray diffraction (GIXD). It consists of a UHV chamber mounted on az-axis type goniometer, equipped with residual gas analysis, reflection high-energy electron diffraction (RHEED) and Auger electron spectroscopy (AES) to complete the X-ray scattering investigations. The chamber has been developed so as up to eight sources of molecular beam epitaxy (MBE) can be simultaneously mounted to elaborate the nanostructures. A chemical vapor deposition (CVD) set-up has been added to expand the range of growing possibilities, in particular to investigatein situthe growth of semiconductor nanowires. This setup is presented in some detail, as well as the firstin situX-ray scattering measurements during the growth of silicon nanowires.
Bunch mode specific rate corrections for PILATUS3 detectors
Authors: Trueb P. , Dejoie C. , Kobas M. , Pattison P. , Peake D. J. , Radicci V. , Sobott B. A. , Walko D. A. , Broennimann C.
Published: April 2015

PILATUS X-ray detectors are in operation at many synchrotron beamlines around the world. This article reports on the characterization of the new PILATUS3 detector generation at high count rates. As for all counting detectors, the measured intensities have to be corrected for the dead-time of the counting mechanism at high photon fluxes. The large number of different bunch modes at these synchrotrons as well as the wide range of detector settings presents a challenge for providing accurate corrections. To avoid the intricate measurement of the count rate behaviour for every bunch mode, a Monte Carlo simulation of the counting mechanism has been implemented, which is able to predict the corrections for arbitrary bunch modes and a wide range of detector settings. This article compares the simulated results with experimental data acquired at different synchrotrons. It is found that the usage of bunch mode specific corrections based on this simulation improves the accuracy of the measured intensities by up to 40% for high photon rates and highly structured bunch modes. For less structured bunch modes, the instant retrigger technology of PILATUS3 detectors substantially reduces the dependency of the rate correction on the bunch mode. The acquired data also demonstrate that the instant retrigger technology allows for data acquisition up to 15 million photons per second per pixel.
A dihydrogen phosphate anionic network as a host lattice for cations in 1-methylpiperazine-1,4-diium bis(dihydrogen phosphate) and 2-(pyridin-2-yl)pyridinium dihydrogen phosphate–orthophosphoric acid (1/1)
Authors: Jagan R. , Sathya D. , Sivakumar K.
Published: April 2015

In the salt 1-methylpiperazine-1,4-diium bis(dihydrogen phosphate), C5H13N22+·2H2PO4−, (I), and the solvated salt 2-(pyridin-2-yl)pyridinium dihydrogen phosphate–orthophosphoric acid (1/1), C10H9N2+·H2PO4−·H3PO4, (II), the formation of O—H...O and N—H...O hydrogen bonds between the dihydrogen phosphate (H2PO4−) anions and the cations constructs a three- and two-dimensional anionic–cationic network, respectively. In (I), the self-assembly of H2PO4−anions forms a two-dimensional pseudo-honeycomb-like supramolecular architecture along the (010) plane. 1-Methylpiperazine-1,4-diium cations are trapped between the (010) anionic layers through three N—H...O hydrogen bonds. In solvated salt (II), the self-assembly of H2PO4−anions forms a two-dimensional supramolecular architecture with open channels projecting along the [001] direction. The 2-(pyridin-2-yl)pyridinium cations are trapped between the open channels by N—H...O and C—H...O hydrogen bonds. From a study of previously reported structures, dihydrogen phosphate anions show a supramolecular flexibility depending on the nature of the cations. The dihydrogen phosphate anion may be suitable for the design of the host lattice for host–guest supramolecular systems.
Crystal structure of febuxostat–acetic acid (1/1)
Authors: Wu Min , Hu Xiu-Rong , Gu Jian-Ming , Tang Gu-Ping
Published: April 2015

The asymmetric unit of the title compound [systematic name: 2-(3-cyano-4-isobutyloxyphenyl)-4-methylthiazole-5-carboxylic acid–acetic acid (1/1)], C16H16N2O3S·CH3COOH, contains a febuxostat molecule and an acetic acid molecule. In the febuxostat molecule, the thiazole ring is nearly coplanar with the benzene ring [dihedral angle = 3.24 (2)°]. In the crystal, the febuxostat and acetic acid molecules are linked by O—H...O, O—H...N hydrogen bonds and weak C—H...O hydrogen bonds, forming supramolecular chains propagating along theb-axis direction. π–π stacking is observed between nearly parallel thiazole and benzene rings of adjacent molecules; the centroid-to-centroid distances are 3.8064 (17) and 3.9296 (17) Å.
Crystal structure of tetrabutylammonium bromide–1,2-diiodo-3,4,5,6-tetrafluorobenzene–dichloromethane (2/2/1)
Authors: Viger-Gravel Jasmine , Korobkov Ilia , Bryce David L.
Published: April 2015

The crystallization of a 1:1 molar solution of 1,2-diiodo-3,4,5,6-tetrafluorobenzene (o-DITFB) and tetrabutylammonium bromide (n-Bu4NBr) from dichloromethane yielded pure white crystals of a halogen-bonded compound, C16H36N+·Br−·C6F4I2·0.5CH2Cl2or [(n-Bu4NBr)(o-DITFB)]·0.5CH2Cl2. The compound may be described as a quaternary system and may be classified as a salt–cocrystal solvate. The asymmetric unit contains one molecule of solvent, twoo-DITFB molecules, two cations (n-Bu4N+) and two crystallographically distinct bromide ions [θI...Br-...I= 144.18 (1) and 135.35 (1)°]. The bromide ion is a bidentate halogen-bond acceptor which interacts with two covalently bonded iodines (i.e.halogen-bond donors), resulting in a one-dimensional polymeric zigzag chain network approximately along theaaxis. The observed short contacts and angles are characteristic of the non-covalent interaction [dC—I...Br= 3.1593 (4)–3.2590 (5) Å; θC—I...Br= 174.89 (7) and 178.16 (7)°]. It is noted that iodine acts as both a halogen-bond donor and a weak CH hydrogen-bond acceptor, while the bromide ions act as acceptors for weak CH hydrogen bonds and halogen bonds.
Crystal structure of 2-(1H-imidazol-4-yl)ethanaminium chloride
Authors: Belfilali Imene , Yebdri Siham , Louhibi Samira , Boukli-hacene Leila , Roisnel Thierry
Published: April 2015

The title molecular salt, C5H10N3+·Cl−, was obtained as by-product in the attempted synthesis of a histamine derivative. The terminal amino group of the starting material is protonated. The Cimidazole—C—C—N(H3)+group in the cation is in ananticonformation with a torsion angle of 176.22 (10)°. In the crystal, cations and anions are linkedviaN—H...N and N—H—Cl hydrogen bonds, forming a two-dimensional network parallel to (10-1). A single weak C—H...Cl hydrogen bond completes a three-dimensional network.
Distribution of the gender wage gap with endogenous human capital: evidence for Spain
Authors: Navarro-Gómez Lucía , Rueda-Narvaez Mario F.
Published: April 2015

Purpose

– The purpose of this paper is to provide empirical evidence on gender wage discrimination and how it is distributed among women in the Spanish labour market, where female participation has been rising for decades. The empirical approach aims to assess to which extent discrimination is evenly distributed or not among women, and how different subgroups of workers are affected by it.

Design/methodology/approach

– Using data from the Spanish section of the European Community Household Panel (1994-2001) the authors estimate earnings equations for men and women using the instrumental variable (IV) method proposed by Hausman and Taylor (1981). This aims to avoid biases resulting from endogeneity of regressors. Building on these results, the authors follow the proposal of Jenkins (1994) and estimate a bivariate wage distribution for women, containing individual expected earnings with and without discrimination.

Findings

– The results show that discrimination is distributed unevenly across female workers and that the degree to which women are discriminated against grows as they move upward in the wage distribution. Also, when wage determinants are allowed to be endogenous, the results experience drastic changes, both in average and distributional terms.

Research limitations/implications

– The results point to a “glass ceiling” operating on female earnings and also show that endogeneity of human capital should be taken into account when analysing discrimination. Therefore, more empirical evidence in this line would be welcome.

Originality/value

– By using IV estimation of wages, the authors control for the existence of endogeneity in earnings equations. Also, the authors provide unexplained wage differentials for particular groups of female wage earners, specially according to education, experience and job tenure.
Developing enterprise skills through peer-assessed pitch presentations
Authors: Faherty Anna
Published: April 2015

Purpose

– The purpose of this paper is to investigate the impact of using summative peer assessment to develop enterprise skills within higher education.

Design/methodology/approach

– An empirical investigation analysing students own perceptions of the peer assessment process to evaluate its impact.

Findings

– Participating students indicate that peer assessment aided the achievement of an enterprise learning outcome relating to persuading and influencing. They also report developing skills that will be useful for the workplace, and identify additional learning benefits. Qualitative feedback suggests some discomfort with the inherent non-traditional instructor-learner relationship.

Research limitations/implications

– Acknowledging the limitations of using students’ own perceptions, the narrow focus on one course and the singular experience of summative peer assessment this investigation highlights the need for additional research into the impact of pedagogies where “teachers” deliver more of a facilitation role.

Practical implications

– The study reinforces the need for educators to invest time and effort in explaining the processes and issues involved with peer assessment. It highlights the contribution that creative industries’ educators might be able to make to the wider development of enterprise skills across higher education disciplines.

Originality/value

– The study contributes to two important but under-explored areas of educational research: the development of enterprise skills outside the business school and the use of peer assessment within enterprise education. It provides a case study for non-traditional assessment and identifies a key challenge associated with the emergent pedagogical approach of heutagogy.
Child schooling in India: the role of gender
Authors: Mohanty Itismita , RAMMOHAN ANU
Published: April 2015

Purpose

– This paper aims to analyse factors that influence child schooling outcomes in India, specifically the role of gender.

Design/methodology/approach

– This paper uses data from the nationally representative Indian National Family Health Surveys 1995-1996 and 2005-2006 and estimates Heckman sample selection, cluster fixed-effects and household fixed-effects econometric models. The dependent variables are the child’s enrolment status and conditional on enrolment child’s years of schooling.

Findings

– This analysis finds statistically significant evidence of male advantage both in schooling enrolment as well as years of schooling. However, using a cluster fixed-effects model, our analysis finds that within a village, conditional on being enrolled, girls spend more years in school relative to boys. Other results show that parental schooling has a positive and statistically significant impact on child schooling. There is statistically significant wealth effect, community effect and regional disparities between states in India.

Originality/value

– The large sample size and the range of questions available in this data set, allows us to explore the influence of individual, household and village level social, economic and cultural factors on child schooling. The role of gender on child schooling within a village, intrahousehold resource allocation for schooling and regional gender differences in schooling are important issues in India, where education outcomes remain poor for large segments of the population.
Multiple model adaptive control using second level adaptation for a delta-wing aircraft
Authors: Ahmadian Narjes , Khosravi Alireza , Sarhadi Pouria
Published: April 2015

Purpose

– The purpose of this paper is to design a stable controller such that the control input is applied to the delta-wing aircraft in order to adjust the roll dynamics. The controller must provide a desired tracking performance with minimum tracking error.

Design/methodology/approach

– In this paper, the second level adaptation (SLA) strategy is applied to control a delta-wing aircraft using multiple models. The implemented control structure is compared with the first level adaptation (FLA) and model reference adaptive control (MRAC) techniques.

Findings

– SLA architecture not only copes with a wide uncertainty domain caused by aerodynamic effects, but also its rapid and accurate convergence is one of its most important features. Furthermore, this strategy makes a smoother control signal with respect to FLA and MRAC even at the same initial times. It should be also noted that SLA using three models, copes with uncertainty that may occur to the aircraft at high Angle Of Attacks (AOAs) at the entire flight envelope.

Originality/value

– In this paper for the first time the application of this strategy is used to identify and control a delta-wing aircraft. Furthermore a systematic block diagram approach is proposed for the design.
Factors influencing the use of social media by SMEs and its performance outcomes
Authors: Ainin Sulaiman , Parveen Farzana , Moghavvemi Sedigheh , Jaafar Noor Ismawati , Mohd Shuib Nor Liyana
Published: April 2015

Purpose

– The purpose of this paper is to investigate the factors that influence Facebook usage among small and medium enterprises (SMEs). In addition, it examines the impact of Facebook usage on financial and non-financial performance of the SMEs.

Design/methodology/approach

– Using integrated model, this study examined the influence of compatibility, cost effectiveness, interactivity and trust on Facebook usage and its subsequent impact on organizations performance. Statistical analyses were based on the data collected, through survey questionnaire from 259 SMEs in Malaysia. Partial Least Square (PLS) method was used to test the hypotheses.

Findings

– The study revealed that Facebook usage has a strong positive impact on financial performance of SMEs; similarly it was also found that Facebook usage positively impacts the non-financial performance of SMEs in terms of cost reduction on marketing and customer service, improved customer relations and improved information accessibility. Additionally, factors such as compatibility, cost effectiveness and interactivity was identified as factors that influence Facebook usage among SMEs.

Research limitations/implications

– This study is limited in selection of samples. The sample only covered one community of SME in Malaysia which limits generalizability of the findings. This study provided a clearer idea on the real importance of Facebook and its benefits. The results would motivate and guide organizations in the adoption of Facebook for business activities. The study also has various theoretical and practical contributions.

Originality/value

– Very few empirical studies investigated the actual impact of Facebook usage among organizations. This study investigated the effect of Facebook usage on the financial performance of the organizations which is really important to study as it reveals the exact value of using Facebook for business activities.