bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase transition-induced band edge engineering of BiVO4to split pure water under visible light
Authors: Jo Won Jun , Kang Hyun Joon , Kong Ki-Jeong , Lee Yun Seog , Park Hunmin , Lee Younghye , Buonassisi Tonio , Gleason Karen K. , Lee Jae Sung
Published: October 2015

Significance

Hydrogen has been recognized as one of the most promising energy carriers for the future, because it can generate enormous energy by clean combustion chemistry without any greenhouse gas emissions. Water splitting under visible light irradiation is an ideal route to cost-effective, large-scale, and sustainable hydrogen production, but it is challenging, because it requires a rare photocatalyst that carries a combination of suitable band gap energy, appropriate band positions, and photochemical stability. To create this rare photocatalyst, we engineered the band edges of BiVO4by simultaneously substituting In3+for Bi3+and Mo6+for V5+in the host lattice of monoclinic BiVO4, which induced partial phase transformation from pure monoclinic BiVO4to a mixture of monoclinic BiVO4and tetragonal BiVO4.
Allosteric activation of M
4
muscarinic receptors improve behavioral and physiological alterations in early symptomatic YAC128 mice
Authors: Pancani Tristano , Foster Daniel J. , Moehle Mark S. , Bichell Terry Jo , Bradley Emma , Bridges Thomas M. , Klar Rebecca , Poslusney Mike , Rook Jerri M. , Daniels J. Scott , Niswender Colleen M. , Jones Carrie K. , Wood Michael R. , Bowman Aaron B. , Lindsley Craig W. , Xiang Zixiu , Conn P. Jeffrey
Published: October 2015

Significance

Huntington’s disease (HD) is a devastating neurodegenerative genetic disorder characterized by progressive decline of motor control. Although the genetic mutation responsible for the syndrome associated with HD has been clearly identified, a specific treatment for HD is not yet available. Therefore, there is a tremendous need for new therapeutic approaches and new molecular therapeutic targets. Using HD mouse models, we show age-dependent alterations of corticostriatal transmission paralleled by alterations of M
4
muscarinic acetylcholine receptor (mAChR)-mediated control of corticostriatal glutamate signaling. Also, chronic treatment with the selective M
4
mAChR positive allosteric modulator VU0467154 improves motor and synaptic deficits in 5-mo-old YAC128 mice. This suggests that M
4
may represent a therapeutic target for the treatment of HD.
Discovery of the magnetic behavior of hemoglobin: A beginning of bioinorganic chemistry
Authors: Bren Kara L. , Eisenberg Richard , Gray Harry B.
Published: October 2015

Two articles published by Pauling and Coryell in PNAS nearly 80 years ago described in detail the magnetic properties of oxy- and deoxyhemoglobin, as well as those of closely related compounds containing hemes. Their measurements revealed a large difference in magnetism between oxygenated and deoxygenated forms of the protein and, along with consideration of the observed diamagnetism of the carbonmonoxy derivative, led to an electronic structural formulation of oxyhemoglobin. The key role of hemoglobin as the main oxygen carrier in mammalian blood had been established earlier, and its allosteric behavior had been described in the 1920s. The Pauling–Coryell articles on hemoglobin represent truly seminal contributions to the field of bioinorganic chemistry because they are the first to make connections between active site electronic structure and the function of a metalloprotein.
Hypophagia and metabolic adaptations in mice with defective ATGL-mediated lipolysis cause resistance to HFD-induced obesity
Authors: Schreiber Renate , Hofer Peter , Taschler Ulrike , Voshol Peter J. , Rechberger Gerald N. , Kotzbeck Petra , Jaeger Doris , Preiss-Landl Karina , Lord Caleb C. , Brown J. Mark , Haemmerle Guenter , Zimmermann Robert , Vidal-Puig Antonio , Zechner Rudolf
Published: October 2015

Significance

The mass of white adipose tissue (WAT) in an organism is tightly controlled by the balance of triglyceride (TG) synthesis and catabolism. Here, we show that these opposing pathways communicate. TG catabolism by adipose triglyceride lipase (ATGL) activates peroxisome proliferator-activated receptor gamma (PPAR-γ), a crucial transcription factor for TG synthesis and storage in WAT. Consequently, ATGL deficiency in WAT not only impairs TG breakdown, but also PPAR-γ–driven TG formation. This decrease in TG synthesis leads to a paradoxical resistance to high fat diet-induced obesity in mice lacking ATGL. Interdependence of lipid catabolism and synthesis provides a rational explanation for the lack of obesity in ATGL-deficient mice and humans and identifies ATGL inhibition as potential treatment target to prevent diet-induced obesity and insulin resistance.
Fundamental insights into ontogenetic growth from theory and fish
Authors: Sibly Richard M. , Baker Joanna , Grady John M. , Luna Susan M. , Kodric-Brown Astrid , Venditti Chris , Brown James H.
Published: October 2015

Significance

Understanding growth of fish is important, both for regulating harvests of wild populations for sustained yields, and for using artificial selection and genetic engineering to increase productivity of domesticated fish stocks. We developed theory to account for how growth rate varies with body size, within individuals as they grow to maturity and across species as they evolve. Data on fish growth in FishBase supported our theoretical predictions. We found that growth rates scaled differently in populations of the same species than they scaled across species. We suggest that similar developmental programs of close relatives constrain growth, but as species diverge over evolutionary time they evolve the near-optimal −1/4 power scaling predicted by metabolic scaling theory.
The essential gene set of a photosynthetic organism
Authors: Rubin Benjamin E. , Wetmore Kelly M. , Price Morgan N. , Diamond Spencer , Shultzaberger Ryan K. , Lowe Laura C. , Curtin Genevieve , Arkin Adam P. , Deutschbauer Adam , Golden Susan S.
Published: October 2015

Significance

Cyanobacteria are model organisms for photosynthesis in the laboratory, are key producers of the chemical energy that drives life, and are being developed as biofuel and chemical producers for industry. Despite the importance of these organisms for environmental and biotechnological applications, only a small percentage of cyanobacterial genes and intergenic regions have been experimentally evaluated for their impact on the organisms’ survival. Here, we present experimental analysis of the complete set of genomic regions necessary for survival in a cyanobacterium achieved by screening for the fitness of hundreds of thousands of mutants. In addition to improving our fundamental understanding of Cyanobacteria, this research more broadly provides a snapshot of the essential genes and intergenic regions necessary to live the photosynthetic lifestyle.
Biochemical characteristics and antioxidant activity of crude and purified sulfated polysaccharides from Gracilaria fisheri
Authors: Imjongjairak Siriluck , Ratanakhanokchai Khanok , Laohakunjit Natta , Tachaapaikoon Chakrit , Pason Patthra , Waeonukul Rattiya
Published: October 2015

Sulfated polysaccharides (SPs) from Gracilaria fisheri of Thailand, which were extracted in low-temperature (25 °C) water showed the highest content of phenolic compounds compared with those extracted at high temperature (55 °C). Crude SP antioxidant activity was evaluated by measuring the DPPH free radical scavenging effect which is directly related to the level of phenolic compounds. The sulfate content, total sugar, and SPs yield were also directly related to the extraction temperature. All extracts contained galactose as a major monosaccharide. High antioxidant activity of crude SP, positively correlated with the phenolic compound contents (R2 = 0.996) contributed by the existence of sulfate groups and phenolic compounds. In purified SP, F1 fraction exhibited strong radical scavenging ability, but it was not significantly different compared to crude SP extracted at 25 °C. This indicated that the appropriate density and distribution of sulfate groups in the SP extract showed the best antioxidant activity.
Poor precompetitive sleep habits, nutrients’ deficiencies, inappropriate body composition and athletic performance in elite gymnasts
Authors: Silva M.‐R. G. , Paiva T.
Published: October 2015

This study aimed to evaluate body composition, sleep, precompetitive anxiety and dietary intake on the elite female gymnasts’ performance prior to an international competition. Sixty‐seven rhythmic gymnasts of high performance level were evaluated in relation to sport and training practice, body composition, sleep duration, daytime sleepiness by the Epworth Sleepiness Scale (ESS), sleep quality by the Pittsburgh Sleep Quality Index (PSQI), precompetitive anxiety by the Sport Competition Anxiety Test form A (SCAT‐A) and detailed dietary intake just before an international competition. Most gymnasts (67.2%) suffered from mild daytime sleepiness, 77.6% presented poor sleep quality and 19.4% presented high levels of precompetitive anxiety. The majority of gymnasts reported low energy availability (EA) and low intakes of important vitamins including folate, vitamins D, E and K; and minerals, including calcium, iron, boron and magnesium (p < .05). Gymnasts’ performance was positively correlated with age (p = .001), sport practice (p = .024), number of daily training hours (p = .000), number of hours of training/week (p = .000), waist circumference (WC) (p = .008) and sleep duration (p = .005). However, it was negatively correlated with WC/hip circumference (p = .000), ESS (p = .000), PSQI (p = .042), SCAT‐A (p = .002), protein g/kg (p = .028), EA (p = .002) and exercise energy expenditure (p = .000). High performance gymnasts presented poor sleep habits with consequences upon daytime sleepiness, sleep quality and low energy availability.
Profiling the Role of Mammalian Target of Rapamycin in the Vascular Smooth Muscle Metabolome in Pulmonary Arterial Hypertension
Authors: Kudryashova Tatiana V. , Goncharov Dmitry A. , Pena Andressa , Ihida‐Stansbury Kaori , DeLisser Horace , Kawut Steven M. , Goncharova Elena A.
Published: October 2015

Increased proliferation and resistance to apoptosis of pulmonary arterial vascular smooth muscle cells (PAVSMCs), coupled with metabolic reprogramming, are key components of pulmonary vascular remodeling, a major and currently irreversible pathophysiological feature of pulmonary arterial hypertension (PAH). We recently reported that activation of mammalian target of rapamycin (mTOR) plays a key role in increased energy generation and maintenance of the proliferative, apoptosis‐resistant PAVSMC phenotype in human PAH, but the downstream effects of mTOR activation on PAH PAVSMC metabolism are not clear. Using liquid and gas chromatography–based mass spectrometry, we performed pilot metabolomic profiling of human microvascular PAVSMCs from idiopathic‐PAH subjects before and after treatment with the selective adenosine triphosphate–competitive mTOR inhibitor PP242 and from nondiseased lungs. We have shown that PAH PAVSMCs have a distinct metabolomic signature of altered metabolites—components of fatty acid synthesis, deficiency of sugars, amino sugars, and nucleotide sugars—intermediates of protein and lipid glycosylation, and downregulation of key biochemicals involved in glutathione and nicotinamide adenine dinucleotide (NAD) metabolism. We also report that mTOR inhibition attenuated or reversed the majority of the PAH‐specific abnormalities in lipogenesis, glycosylation, glutathione, and NAD metabolism without affecting altered polyunsaturated fatty acid metabolism. Collectively, our data demonstrate a critical role of mTOR in major PAH PAVSMC metabolic abnormalities and suggest the existence of de novo lipid synthesis in PAVSMCs in human PAH that may represent a new, important component of disease pathogenesis worthy of future investigation.
A Julia-Wolff-Carathéodory theorem for infinitesimal generators in the unit ball
Authors: Abate Marco , Raissy Jasmin
Published: October 2015

We prove a Julia-Wolff-Carathédory theorem on angular derivatives of infinitesimal generators of one-parameter semigroups of holomorphic self-maps of the unit ball

B
n

⊂

C

n

B^n\subset \mathbb {C}^n

, starting from results recently obtained by Bracci and Shoikhet.
Omokage search: shape similarity search service for biomolecular structures in both the PDB and EMDB
Authors: Suzuki Hirofumi , Kawabata Takeshi , Nakamura Haruki
Published: October 2015

Summary:  Omokage search is a service to search the global shape similarity of biological macromolecules and their assemblies, in both the Protein Data Bank (PDB) and Electron Microscopy Data Bank (EMDB). The server compares global shapes of assemblies independent of sequence order and number of subunits. As a search query, the user inputs a structure ID (PDB ID or EMDB ID) or uploads an atomic model or 3D density map to the server. The search is performed usually within 1 min, using one-dimensional profiles (incremental distance rank profiles) to characterize the shapes. Using the gmfit (Gaussian mixture model fitting) program, the found structures are fitted onto the query structure and their superimposed structures are displayed on the Web browser. Our service provides new structural perspectives to life science researchers.

Availability and implementation:  Omokage search is freely accessible at http://pdbj.org/omokage/.

Contact:  hirofumi@protein.osaka-u.ac.jp

Supplementary information:  Supplementary data are available at Bioinformatics online.
caRpools: an R package for exploratory data analysis and documentation of pooled CRISPR/Cas9 screens
Authors: Winter Jan , Breinig Marco , Heigwer Florian , Brügemann Dirk , Leible Svenja , Pelz Oliver , Zhan Tianzuo , Boutros Michael
Published: October 2015

Motivation: Genetic screens by CRISPR/Cas9-mediated genome engineering have become a powerful tool for functional genomics. However, there is currently a lack of end-to-end software pipelines to analyze CRISPR/Cas9 screens based on next generation sequencing.

Results: The CRISPR-AnalyzeR for pooled screens (caRpools) is an R package for exploratory data analysis that provides a complete workflow to analyze CRISPR/Cas9 screens. To further support the analysis of large-scale screens, caRpools integrates screening documentation and generation of standardized analysis reports.

Availability and implementation: caRpools, manuals and an open virtual appliance are available at http://github.com/boutroslab/caRpools.

Contact:  m.boutros@dkfz.de
PPIXpress: construction of condition-specific protein interaction networks based on transcript expression
Authors: Will Thorsten , Helms Volkhard
Published: October 2015

Summary: Protein–protein interaction networks are an important component of modern systems biology. Yet, comparatively few efforts have been made to tailor their topology to the actual cellular condition being studied. Here, we present a network construction method that exploits expression data at the transcript-level and thus reveals alterations in protein connectivity not only caused by differential gene expression but also by alternative splicing. We achieved this by establishing a direct correspondence between individual protein interactions and underlying domain interactions in a complete but condition-unspecific protein interaction network. This knowledge was then used to infer the condition-specific presence of interactions from the dominant protein isoforms. When we compared contextualized interaction networks of matched normal and tumor samples in breast cancer, our transcript-based construction identified more significant alterations that affected proteins associated with cancerogenesis than a method that only uses gene expression data. The approach is provided as the user-friendly tool PPIXpress.

Availability and implementation: PPIXpress is available at https://sourceforge.net/projects/ppixpress/.

Contact:  volkhard.helms@bioinformatik.uni-saarland.de

Supplementary information:  Supplementary data are available at Bioinformatics online.
Do radio mini-halos and gas heating in cool-core clusters have a common origin?
Authors: Bravi L. , Gitti M. , Brunetti G.
Published: October 2015

In this Letter, we present a study of the central regions of cool-core clusters hosting radio mini-halos, which are diffuse synchrotron sources extended on cluster-scales surrounding the radio-loud brightest cluster galaxy. We aim to investigate the interplay between the thermal and non-thermal components in the intracluster medium in order to get more insights into these radio sources, whose nature is still unclear. It has recently been proposed that turbulence plays a role for heating the gas in cool cores. By assuming that mini-halos are powered by the same turbulence, we expect that the integrated radio luminosity of mini-halos, νPν, depends on the cooling flow power, PCF, which in turn constrains the energy available for the non-thermal components and emission in the cool-core region. We carried out a homogeneous re-analysis of X-ray Chandra data of the largest sample of cool-core clusters hosting radio mini-halos currently available (∼20 objects), finding a quasi-linear correlation, $\nu P_{\nu } \propto P_{\rm CF}^{0.8}$. We show that the scenario of a common origin of radio mini-halos and gas heating in cool-core clusters is energetically viable, provided that mini-halos trace regions where the magnetic field strength is B ≫ 0.5 μG.
Zhu Chen: health care reform in China
Authors: Poo Mu-ming , Wang Ling
Published: October 2015

As China's economy continues to prosper, adequate health care for all people has become an uppermost issue for the government. In 2007, as China began its reform of the health care system on a scale unprecedented in recent history, Zhu Chen was appointed to head the Ministry of Health and took charge of this formidable task. Since leaving his Ministry post in 2013, Chen remains actively involved in the formulation of China's health care-related policies in his capacity as a Vice Chairman of the Standing Committee of the National People's Congress of China, the Chairman of the Chinese Peasants and Workers Democratic Party, and most recently the President of the Red Cross Society of China. In addition to his achievements in administrative services, Chen also had a distinguished research career and is internationally recognized for his contribution in developing the most effective therapy for acute promyelocytic leukemia (APL). In a recent interview with NSR, Chen summarized and reflected upon his experience as the Health Minister, and expressed his view on the current status and future prospect of health care reform in China, and a variety of related issues in translational medicine, medical personnel training, precision medicine, and big data for health care in China.
Where were the monsoon regions and arid zones in Asia prior to the Tibetan Plateau uplift?
Authors: Liu Xiaodong , Guo Qingchun , Guo Zhengtang , Yin Zhi-Yong , Dong Buwen , Smith Robin
Published: October 2015

The impact of the Tibetan Plateau uplift on the Asian monsoons and inland arid climates is an important but also controversial question in studies of paleoenvironmental change during the Cenozoic. In order to achieve a good understanding of the background for the formation of the Asian monsoons and arid environments, it is necessary to know the characteristics of the distribution of monsoon regions and arid zones in Asia before the plateau uplift. In this study, we discuss in detail the patterns of distribution of the Asian monsoon and arid regions before the plateau uplift on the basis of modeling results without topography from a global coupled atmosphere–ocean general circulation model, compare our results with previous simulation studies and available biogeological data, and review the uncertainties in the current knowledge. Based on what we know at the moment, tropical monsoon climates existed south of 20°N in South and Southeast Asia before the plateau uplift, while the East Asian monsoon was entirely absent in the extratropics. These tropical monsoons mainly resulted from the seasonal shifts of the Inter-Tropical Convergence Zone. There may have been a quasi-monsoon region in central-southern Siberia. Most of the arid regions in the Asian continent were limited to the latitudes of 20–40°N, corresponding to the range of the subtropical high pressure year-around. In the meantime, the present-day arid regions located in the relatively high latitudes in Central Asia were most likely absent before the plateau uplift. The main results from the above modeling analyses are qualitatively consistent with the available biogeological data. These results highlight the importance of the uplift of the Tibetan Plateau in the Cenozoic evolution of the Asian climate pattern of dry–wet conditions. Future studies should be focused on effects of the changes in land–sea distribution and atmospheric CO2 concentrations before and after the plateau uplift, and also on cross-comparisons between numerical simulations and geological evidence, so that a comprehensive understanding of the evolution of the Cenozoic paleoenvironments in Asia can be achieved.
p16 Immunohistochemistry is Less Useful Than MDM2 and CDK4 to Distinguish Dedifferentiated Liposarcomas From Other Retroperitoneal Mimics
Authors: Kang Yuna , Horvai Andrew E.
Published: October 2015

Dedifferentiated liposarcoma (DDL) frequently involves the retroperitoneum. In the absence of a lipogenic component histologically, the differential diagnosis of a retroperitoneal DDL includes other sarcomas and, if the tumor has visceral involvement, sarcomatoid carcinoma. DDL demonstrates amplification of chromosome subregion 12q13-q15. Detection of the amplification itself, or the resulting overexpression of the MDM2 and CDK4 genes by genetic and immunohistochemical methods, is a useful ancillary test in the diagnosis of DDL. More recently, immunohistochemistry for p16Ink4A, the product of the CDKN2A gene, was shown to be a useful adjunct in differentiating well-differentiated liposarcoma from benign adipocytic tumors. In the present study, we examined the utility of p16 immunohistochemistry to distinguish DDL (n=44) from other high-grade and low-grade retroperitoneal mimics (n=73). p16 positivity was observed in 43/44 (98%) DDLs, with the majority of these showing strong, diffuse, staining. The rate of p16 positivity in other retroperitoneal tumors was lower (37/73, 51%) and staining was not as consistently diffuse or intense. Furthermore, p16 positivity varied between the control sarcomas based on tumor type as follows: 11/11 leiomyosarcomas, 8/11 pleomorphic undifferentiated sarcomas, 9/39 sarcomatoid carcinomas, 7/7 desmoid tumors, 1/3 endometrial stromal sarcomas, and 1/2 malignant gastrointestinal stromal tumors. On the basis of these findings, we conclude that p16 is highly sensitive for retroperitoneal DDL. However, the lack of specificity limits the diagnostic utility compared with the more established markers MDM2 and CDK4.
Breeding phenology and winter activity predict subsequent breeding success in a trans-global migratory seabird
Authors: Shoji A. , Aris-Brosou S. , Culina A. , Fayet A. , Kirk H. , Padget O. , Juarez-Martinez I. , Boyle D. , Nakata T. , Perrins C. M. , Guilford T.
Published: October 2015

Inter-seasonal events are believed to connect and affect reproductive performance (RP) in animals. However, much remains unknown about such carry-over effects (COEs), in particular how behaviour patterns during highly mobile life-history stages, such as migration, affect RP. To address this question, we measured at-sea behaviour in a long-lived migratory seabird, the Manx shearwater (Puffinus puffinus) and obtained data for individual migration cycles over 5 years, by tracking with geolocator/immersion loggers, along with 6 years of RP data. We found that individual breeding and non-breeding phenology correlated with subsequent RP, with birds hyperactive during winter more likely to fail to reproduce. Furthermore, parental investment during one year influenced breeding success during the next, a COE reflecting the trade-off between current and future RP. Our results suggest that different life-history stages interact to influence RP in the next breeding season, so that behaviour patterns during winter may be important determinants of variation in subsequent fitness among individuals.
Resurrecting embryos of the tuatara,
Sphenodon punctatus
, to resolve vertebrate phallus evolution
Authors: Sanger Thomas J. , Gredler Marissa L. , Cohn Martin J.
Published: October 2015

The breadth of anatomical and functional diversity among amniote external genitalia has led to uncertainty about the evolutionary origins of the phallus. In several lineages, including the tuatara,
Sphenodon punctatus
, adults lack an intromittent phallus, raising the possibility that the amniote ancestor lacked external genitalia and reproduced using cloacal apposition. Accordingly, a phallus may have evolved multiple times in amniotes. However, similarities in development across amniote external genitalia suggest that the phallus may have a single evolutionary origin. To resolve the evolutionary history of amniote genitalia, we performed three-dimensional reconstruction of Victorian era tuatara embryos to look for embryological evidence of external genital initiation. Despite the absence of an intromittent phallus in adult tuataras, our observations show that tuatara embryos develop genital anlagen. This illustrates that there is a conserved developmental stage of external genital development among all amniotes and suggests a single evolutionary origin of amniote external genitalia.
The ice-breaker effect: singing mediates fast social bonding
Authors: Pearce Eiluned , Launay Jacques , Dunbar Robin I. M.
Published: October 2015

It has been proposed that singing evolved to facilitate social cohesion. However, it remains unclear whether bonding arises out of properties intrinsic to singing or whether any social engagement can have a similar effect. Furthermore, previous research has used one-off singing sessions without exploring the emergence of social bonding over time. In this semi-naturalistic study, we followed newly formed singing and non-singing (crafts or creative writing) adult education classes over seven months. Participants rated their closeness to their group and their affect, and were given a proxy measure of endorphin release, before and after their class, at three timepoints (months 1, 3 and 7). We show that although singers and non-singers felt equally connected by timepoint 3, singers experienced much faster bonding: singers demonstrated a significantly greater increase in closeness at timepoint 1, but the more gradual increase shown by non-singers caught up over time. This represents the first evidence for an ‘ice-breaker effect’ of singing in promoting fast cohesion between unfamiliar individuals, which bypasses the need for personal knowledge of group members gained through prolonged interaction. We argue that singing may have evolved to quickly bond large human groups of relative strangers, potentially through encouraging willingness to coordinate by enhancing positive affect.
Histological evidence for a supraspinous ligament in sauropod dinosaurs
Authors: Cerda Ignacio A. , Casal Gabriel A. , Martinez Rubén D. , Ibiricu Lucio M.
Published: October 2015

Supraspinous ossified rods have been reported in the sacra of some derived sauropod dinosaurs. Although different hypotheses have been proposed to explain the origin of this structure, histological evidence has never been provided to support or reject any of them. In order to establish its origin, we analyse and characterize the microstructure of the supraspinous rod of two sauropod dinosaurs from the Upper Cretaceous of Argentina. The supraspinous ossified rod is almost entirely formed by dense Haversian bone. Remains of primary bone consist entirely of an avascular tissue composed of two types of fibre-like structures, which are coarse and longitudinally (parallel to the main axis of the element) oriented. These structures are differentiated on the basis of their optical properties under polarized light. Very thin fibrous strands are also observed in some regions. These small fibres are all oriented parallel to one another but perpendicular to the element main axis. Histological features of the primary bone tissue indicate that the sacral supraspinous rod corresponds to an ossified supraspinous ligament. The formation of this structure appears to have been a non-pathological metaplastic ossification, possibly induced by the continuous tensile forces applied to the element.
Guided waves' dispersion curves in anisotropic viscoelastic single- and multi-layered media
Authors: Quintanilla F. Hernando , Fan Z. , Lowe M. J. S. , Craster R. V.
Published: October 2015

Guided waves propagating in lossy media are encountered in many problems across different areas of physics such as electromagnetism, elasticity and solid-state physics. They also constitute essential tools in several branches of engineering, aerospace and aircraft engineering, and structural health monitoring for instance. Waveguides also play a central role in many non-destructive evaluation applications. It is of paramount importance to accurately represent the material of the waveguide to obtain reliable and robust information about the guided waves that might be excited in the structure. A reasonable approximation to real solids is the perfectly elastic approach where the frictional losses within the solid are ignored. However, a more realistic approach is to represent the solid as a viscoelastic medium with attenuation for which the dispersion curves of the modes are, in general, different from their elastic counterparts. Existing methods are capable of calculating dispersion curves for attenuated modes but they can be troublesome to find and the solutions are not as reliable as in the perfectly elastic case. In this paper, in order to achieve robust and accurate results for viscoelasticity a spectral collocation method is developed to compute the dispersion curves in generally anisotropic viscoelastic media in flat and cylindrical geometry. Two of the most popular models to account for material damping, Kelvin–Voigt and Hysteretic, are used in various cases of interest. These include orthorhombic and triclinic materials in single- or multi-layered arrays. Also, and due to its importance in industry, a section is devoted to pipes filled with viscous fluids. The results are validated by comparison with those from semi-analytical finite-element simulations.
Stochastic rainfall-runoff model with explicit soil moisture dynamics
Authors: Bartlett M. S. , Daly E. , McDonnell J. J. , Parolari A. J. , Porporato A.
Published: October 2015

Stream runoff is perhaps the most poorly represented process in ecohydrological stochastic soil moisture models. Here we present a rainfall-runoff model with a new stochastic description of runoff linked to soil moisture dynamics. We describe the rainfall-runoff system as the joint probability density function (PDF) of rainfall, soil moisture and runoff forced by random, instantaneous jumps of rainfall. We develop a master equation for the soil moisture PDF that accounts explicitly for a general state-dependent rainfall-runoff transformation. This framework is then used to derive the joint rainfall-runoff and soil moisture-runoff PDFs. Runoff is initiated by a soil moisture threshold and a linear progressive partitioning of rainfall based on the soil moisture status. We explore the dependence of the PDFs on the rainfall occurrence PDF (homogeneous or state-dependent Poisson process) and the rainfall magnitude PDF (exponential or mixed-exponential distribution). We calibrate the model to 63 years of rainfall and runoff data from the Upper Little Tennessee watershed (USA) and show how the new model can reproduce the measured runoff PDF.
Initial stress symmetry and its applications in elasticity
Authors: Gower A. L. , Ciarletta P. , Destrade M.
Published: October 2015

An initial stress within a solid can arise to support external loads or from processes such as thermal expansion in inert matter or growth and remodelling in living materials. For this reason, it is useful to develop a mechanical framework of initially stressed solids irrespective of how this stress formed. An ideal way to do this is to write the free energy density
Ψ
in terms of initial stress
τ
and the elastic deformation gradient
F
, so we write
Ψ
=
Ψ
(
F
,
τ
). In this paper, we present a new constitutive condition for initially stressed materials, which we call the initial stress symmetry (ISS). We focus on two consequences of this condition. First, we examine how ISS restricts the possible choices of free energy densities
Ψ
=
Ψ
(
F
,
τ
) and present two examples of
Ψ
that satisfy the ISS. Second, we show that the initial stress can be derived from the Cauchy stress and the elastic deformation gradient. To illustrate, we take an example from biomechanics and calculate the optimal Cauchy stress within an artery subjected to internal pressure. We then use ISS to derive the optimal target residual stress for the material to achieve after remodelling, which links nicely with the notion of homeostasis.
Cambrian cinctan echinoderms shed light on feeding in the ancestral deuterostome
Authors: Rahman Imran A. , Zamora Samuel , Falkingham Peter L. , Phillips Jeremy C.
Published: October 2015

Reconstructing the feeding mode of the latest common ancestor of deuterostomes is key to elucidating the early evolution of feeding in chordates and allied phyla; however, it is debated whether the ancestral deuterostome was a tentaculate feeder or a pharyngeal filter feeder. To address this, we evaluated the hydrodynamics of feeding in a group of fossil stem-group echinoderms (cinctans) using computational fluid dynamics. We simulated water flow past three-dimensional digital models of a Cambrian fossil cinctan in a range of possible life positions, adopting both passive tentacular feeding and active pharyngeal filter feeding. The results demonstrate that an orientation with the mouth facing downstream of the current was optimal for drag and lift reduction. Moreover, they show that there was almost no flow to the mouth and associated marginal groove under simulations of passive feeding, whereas considerable flow towards the animal was observed for active feeding, which would have enhanced the transport of suspended particles to the mouth. This strongly suggests that cinctans were active pharyngeal filter feeders, like modern enteropneust hemichordates and urochordates, indicating that the ancestral deuterostome employed a similar feeding strategy.
Health and disease imprinted in the time variability of the human microbiome
Authors: Martí Jose Manuel , Martínez Daniel M. , Gracia César , Latorre Amparo , Moya Andrés , Garay Carlos P.
Published: October 2015

Human microbiota plays an important role in determining changes from health to disease. Increasing research activity is dedicated to understand its diversity and variability. We analyse 16S rRNA and whole genome sequencing (WGS) data from the gut microbiota of 97 individuals monitored in time. Temporal fluctuations in the microbiome reveal significant differences due to factors that affect the microbiota such as dietary changes, antibiotic intake, early gut development or disease. Here we show that a fluctuation scaling law describes the temporal variability of the system and that a noise-induced phase transition is central in the route to disease. The universal law distinguishes healthy from sick microbiota and quantitatively characterizes the path in the phase space, which opens up its potential clinical use and, more generally, other technological applications where microbiota plays an important role.

PACS numbers:
Are positive learning experiences levers for lifelong learning among low educated workers?
Authors: Sanders Jos M.A.F. , Damen Marc A.W. , Van Dam Karen
Published: October 2015

Purpose

– Based on the theory of planned behaviour and social learning theory, the purpose of this paper is to investigate the effect of training participation and learning experience on the beliefs of low-educated employees about their self-efficacy for learning.

Design/methodology/approach

– Low-educated workers of three different organizations (n=359) filled out a questionnaire at three different points in time, with a half-yearly interval. Regression analyses were used to establish the effects of training participation and learning experience on learning self-efficacy.

Findings

– Training participation alone did not affect low-educated workers’ learning self-efficacy, but a positive learning experience did contribute to workers’ post-training learning self-efficacy. These results support the relevance of positive learning experiences.

Research limitations/implications

– Follow-up studies could focus on the effects of learning self-efficacy for subsequent learning activities, establish which aspects of training contribute to a positive learning experience, and include contextual characteristics that may predict learning self-efficacy.

Practical implications

– To stimulate learning among lower educated workers, it is necessary that they have confidence in their ability to successfully complete their training. Trainers and training developers working for this specific target group of lower educated workers should aim to provide training that is a positive experience, besides being a learning exercise.

Originality/value

– The study is the first to analyse the longitudinal effects of training participation and learning experience on post-training learning self-efficacy among low-educated workers.
Incentives and gaming in a nonlinear compensation scheme
Authors: Owan Hideo , Tsuru Tsuyoshi , Uehara Katsuhito
Published: October 2015

Purpose

– Under a discontinuous and nonlinear compensation scheme, which is prevalent among car dealerships, the amount of a salesperson’s expected daily commission depends primarily on his position in the pay schedule on the day he makes a sale. Salespeople thus vary their efforts and adopt a different pricing strategy week by week, or even day by day. The purpose of this paper is to examine the incentive effect of such a nonlinear scheme and provide the evidence that salespeople’s behavior is consistent with the theory.

Design/methodology/approach

– The authors conduct regression analyses using the transaction data provided by two North American auto dealerships. The authors construct a daily measure of varying incentive intensity and evaluate its impact on the distribution of individual daily sales and the dealership’s gross profit rate.

Findings

– The authors find that the daily measure of varying incentive intensity has a positive effect on the distribution of individual daily sales and a negative impact on the dealership’s gross profit rate. The results suggest that: salespeople adjust their effort levels in response to the intensity of incentives; and they game the system by lowering the prices when the marginal return to doing so is high.

Research limitations/implications

– The study shows that there is a high cost associated with the discontinuous nonlinear pay scheme, raising the question of why many auto dealerships use it.

Originality/value

– This paper sheds light on the undesirable aspects of discontinuous and nonlinear incentive schemes, varied performance and gaming, by quantifying the effects of the worker’s behavior.
HPWS, technology and flexibility in the Spanish manufacturing industry
Authors: Shijaku Elio , Larraza-Kintana Martin , Urtasun-Alonso Ainhoa
Published: October 2015

Purpose

– High-Performance Work Systems (HPWS) are viewed as strategic levers to a firm’s core competencies’ sustainability and continuous competitive advantage. The purpose of this paper is to explore what factors facilitate HPWS utilization, with a particular focus on the extent to which social capital (SC) derived from buyer-supplier relationships functions as a communication channel to spread effective HPWS implementation.

Design/methodology/approach

– The authors propose a model of HPWS in which external SC not only favors the use of HPWS but also moderates the incidence of other common facilitators such as technology and flexibility. The study uses data from Spanish manufacturing industry.

Findings

– Firms yielding external SC use HPWS more intensely, and the effect of technology constituents on HPWS utilization is contingent on SC accumulation. The findings are consistent with the existing HR literature on the subject but broaden its perspective by analyzing a specific pattern of SC and its pivotal role in the HPWS utilization process.

Research limitations/implications

– The cross-sectional nature of the database leaves open the possibility of causality relationship exploration between the variables of interest, which means that any causal interpretation should be cautious and properly motivated. The study is conducted in the Spanish manufacturing industry context, hence aims to generalize its results by explaining the logic behind the coexistence of HPWS and SC on a same conceptual level. This should be carefully treated and could be further strengthened by other country-level research. The approach does not consider the internal synergic mechanisms and the integration of HR practices.

Practical implications

– The paper reveals the importance of inter-organizational SC in the Spanish manufacturing industry by showing how its embodiment in buyer-supplier relationships may allow firms to better understand the context in which HPWS are more likely to be useful.

Social implications

– The impact of social relationships on effective human resource management practices is highlighted.

Originality/value

– The authors explore the factors that facilitate HPWS utilization, with a particular focus on the extent to which SC derived from buyer-supplier relationships functions as a communication channel to spread effective HPWS implementation.
Financial and economic stability as ‘two sides of a coin’
Authors: Nasir Muhammad Ali , Ahmad Mushtaq , Ahmad Ferhan , Wu Junjie
Published: October 2015

Purpose

– The purpose of this paper is to provide a different context for considering issues of financial stability and instability, with reference to economic growth and price stability in particular.

Design/methodology/approach

– This paper pursued an empirical exploration of six pillars of financial stability, based on a data set for the UK extending from 1985 (Q1) to 2008 (Q2), through the construction of a vector error correction model, including an impulse response function analysis.

Findings

– The findings show a strong association between the financial and economic stability even in a non-crisis regime. This includes, for example, a strong association exists between the stock market and the real economy; exchange rate appreciation may not provide for long-term real economic growth; inflation does not contribute to real economic growth, both the sensitivity of the economy to yields and a significant lag in transitional effects from financial markets to the real sector; a positive role of credit creation within a non-crisis regime; exchange rate appreciation affects purchasing power; and potential points of linkage between sovereign debt activity and general price levels.

Research limitations/implications

– The findings should be considered in the context of a concept of the economy as fundamentally dynamic and subject to complex cumulative processes.

Practical implications

– The findings indicate there is a role for state oversight and intervention within a non-crisis regime based on the complexity of possible interactions that may undermine financial and price stability, with consequences for their association with economic growth.

Originality/value

– The study provides a new perspective for considering issues of financial stability and instability.
Was there a regulatory approval market for mortgages?
Authors: Crawford Peggy , Forsyth Joetta
Published: October 2015

Purpose

– The purpose of this paper is to examine whether the underserved area requirements for Fannie Mae and Freddie Mac (the government-sponsored enterprises [GSEs]) and the community needs requirements of the Community Reinvestment Act (CRA) contributed to the house price run-up in the USA.

Design/methodology/approach

– This paper predicts the incidence of “Rebounds”, which indicate that a mortgage had been previously denied, to provide evidence on whether certain regulations caused excessively risky mortgage originations. As a different lender rejected the loan given the interest rate that they were willing to charge and information on the borrower, a higher incidence of Rebounds provides evidence that lenders were more frequently disagreeing about loans. This can indicate differences in regulatory pressure or oversight across lenders.

Findings

– This paper provides evidence that the GSEs were purchasing fewer Rebounds directly from lenders. However, evidence suggests that indirectly, the securitization market served as a conduit for Rebounds to the GSEs that needed to satisfy regulatory underserved area requirements. The necessity of complying with the CRA was found to increase Rebounds. Among regulators, the Federal Reserve was found to have been particularly associated with Rebounds.

Originality/value

– The paper’s contribution comes from linking Rebounds to legislative and regulatory influences. This contributes to the literature on excess credit and fraud, as well as the effect of underserved area requirements and the CRA. Also, this paper adds a new dimension to the literature on securitization, by showing the influence of regulation on the securitization of risky mortgages.
Country risk, stock prices, and the exchange rate of the renminbi
Authors: Umar Muhammad , Sun Gang
Published: October 2015

Purpose

– The purpose of this study is to analyze the relationship between country risk, stock prices and the exchange rate of the renminbi (RMB) compared to that of the US dollar.

Design/methodology/approach

– An extended open macroeconomic model with investment–saving, liquidity preference–money supply and aggregate supply functions was used by applying comparative static analysis. After checking the series for stationarity and cointegration, a vector autoregressive model was applied. Lag length was selected based on the Akaike information criterion, and the coefficients were calculated for the overall sample and for pre- and post-July 2005 periods.

Findings

– The stock market index is a significant determinant of variation in the exchange rate: when the Chinese stock market performs well, the RMB appreciates and vice versa. Country risk is not a significant determinant of the exchange rate, but the exchange rate of the RMB is a highly significant determinant of the country risk of China: depreciation of the RMB results in higher country risk and vice versa.

Research limitations/implications

– Linear interpolation was used to calculate the monthly values of some of the variables for which only annual data were available.

Practical implications

– The authorities should revalue the exchange rate of the RMB against the US dollar, which will result in lower country risk for China. One way to achieve this is to strengthen the performance of stock markets.

Originality/value

– To the best of the authors’ knowledge, this is the first study to explore the relationship between the country risk of China and the exchange rate of the RMB. Using an open macroeconomic model, this novel research analyzes the relationships between country risk, stock prices and the exchange rate of the RMB from a different perspective.