bluuebunny/crossref_metadata_2025 huggingface dataset:
The evolution of pitch angles of spiral arms
Authors: Pringle J E , Dobbs C L
Published: October 2019

In spiral galaxies, the pitch angle, α, of the spiral arms is often proposed as a discriminator between theories for the formation of the spiral structure. In Lin–Shu density wave theory, α stays constant in time, being simply a property of the underlying galaxy. In other theories (e.g. tidal interaction, and self-gravity), it is expected that the arms wind up in time, so that to a first approximation $\cot \alpha \propto t$. For these theories, it would be expected that a sample of galaxies observed at random times should show a uniform distribution of $\cot \alpha$. We show that a recent set of measurements of spiral pitch angles (Yu & Ho) is broadly consistent with this expectation.
The second-degree gravity coefficients of Phobos from two Mars Express flybys
Authors: Yang X , Yan J G , Andert T , Ye M , Pätzold M , Hahn M , Jin W T , Li F , Barriot J P
Published: October 2019

Several close spacecraft flybys of Phobos have been performed over the past 40 yr in order to determine the gravity field of this tiny Martian moon. In this work, the second-degree coefficients of the gravity field of Phobos were derived from the radio tracking data of two combined Mars Express flybys (2010 and 2013), by applying a least squares regularized inverse technique, that introduces as an a priori the gravity field retrieved from a shape model based on constant density hypothesis. A gravitational mass estimate of $(7.0765\pm 0.0075)\times 10^5 \, \mathrm{m^3\, s}^{-2}$ and second-degree gravity coefficients C20 = −0.1378 ± 0.0348 and C22 = 0.0166 ± 0.0153(3σ) were derived. The estimated C20 value, in contrast to the value of C20 computed from the shape model under the constant density assumption, supports an inhomogeneous distribution inside Phobos at a confidence interval of 95 per cent (1.96σ). This result indicates a denser mass in the equatorial region or lighter mass in polar areas.
X-shooter observations of strong H2-bearing DLAs at high redshift
Authors: Balashev S A , Klimenko V V , Noterdaeme P , Krogager J-K , Varshalovich D A , Ivanchik A V , Petitjean P , Srianand R , Ledoux C
Published: October 2019

We present results from spectroscopic observations with X-shooter at the Very Large Telescope of seven H2-bearing damped Lyman-α systems (DLAs) at high redshifts (zabs ∼ 2.5–3). These DLAs were originally selected from the presence of strong H2 lines directly seen at the DLA redshift in low-resolution low signal-to-noise ratio SDSS spectra. We confirm the detection of molecular hydrogen in all of them. We measure the column densities of H i, H2 in various rotational levels, and metal species, and associated dust extinction. The metallicities, obtained from undepleted species, are in the range log Z = −0.8 to −0.2. We discuss the chemical enrichment in these clouds and compare their properties with that of other molecular-rich systems selected by other means. In particular, we show that three different methods of pre-selection of H2-bearing DLAs in the SDSS have their own biases but complement each other mostly in terms of chemical enrichment. We use the rotational excitation of H2 molecules together with the fine-structure energy levels of neutral carbon to constrain the physical conditions in the gas with the help of numerical modelling as well as analytical expressions for the surface density at which atomic to molecular conversion happens. We find that the H2-bearing medium revealed by the studied DLAs has typical values for the kinetic temperature, hydrogen density, and UV radiation field of T ∼ 100 K, nH ∼ 100 cm−3, and IUV , respectively, about twice the intensity of the Draine field. Detailed studies combining different selections should therefore bring important clues to understand the H i-H2 transition at high redshift.
Primordial power spectrum and cosmology from black-box galaxy surveys
Authors: Leclercq Florent , Enzi Wolfgang , Jasche Jens , Heavens Alan
Published: October 2019

We propose a new, likelihood-free approach to inferring the primordial matter power spectrum and cosmological parameters from arbitrarily complex forward models of galaxy surveys where all relevant statistics can be determined from numerical simulations, i.e. black boxes. Our approach, which we call simulator expansion for likelihood-free inference (selfi), builds upon approximate Bayesian computation using a novel effective likelihood, and upon the linearization of black-box models around an expansion point. Consequently, we obtain simple ‘filter equations’ for an effective posterior of the primordial power spectrum, and a straightforward scheme for cosmological parameter inference. We demonstrate that the workload is computationally tractable, fixed a priori, and perfectly parallel. As a proof of concept, we apply our framework to a realistic synthetic galaxy survey, with a data model accounting for physical structure formation and incomplete and noisy galaxy observations. In doing so, we show that the use of non-linear numerical models allows the galaxy power spectrum to be safely fitted up to at least kmax = 0.5 h Mpc−1, outperforming state-of-the-art backward-modelling techniques by a factor of ∼5 in the number of modes used. The result is an unbiased inference of the primordial matter power spectrum across the entire range of scales considered, including a high-fidelity reconstruction of baryon acoustic oscillations. It translates into an unbiased and robust inference of cosmological parameters. Our results pave the path towards easy applications of likelihood-free simulation-based inference in cosmology. We have made our code pyselfi and our data products publicly available at http://pyselfi.florent-leclercq.eu.
Observational constraints on the magnetic field of the bright transient Be/X-ray pulsar SXP 4.78
Authors: Semena Andrey N , Lutovinov Alexander A , Mereminskiy Ilya A , Tsygankov Sergey S , Shtykovsky Andrey E , Molkov Sergey V , Poutanen Juri
Published: October 2019

We report results of the spectral and timing analysis of the Be/X-ray pulsar SXP 4.78 using the data obtained during its recent outburst with NuSTAR, Swift, Chandra, and NICER observatories. Using an overall evolution of the system luminosity, spectral analysis, and variability power spectrum we obtain constraints on the neutron star magnetic field strength. We found a rapid evolution of the variability power spectrum during the rise of the outburst, and absence of the significant changes during the flux decay. Several low frequency quasi-periodic oscillation features are found to emerge on the different stages of the outburst, but no clear clues on their origin were found in the energy spectrum and overall flux behaviour. We use several indirect methods to estimate the magnetic field strength on the neutron star surface and found that most of them suggest magnetic field B ≲ 2 × 1012 G. The strictest upper limit comes from the absence of the cyclotron absorption features in the energy spectra and suggests relatively weak magnetic field B < 6 × 1011 G.)
The total stellar halo mass of the Milky Way
Authors: Deason Alis J , Belokurov Vasily , Sanders Jason L
Published: October 2019

We measure the total stellar halo luminosity using red giant branch (RGB) stars selected from Gaia data release 2. Using slices in magnitude, colour, and location on the sky, we decompose RGB stars belonging to the disc and halo by fitting two-dimensional Gaussians to the Galactic proper motion distributions. The number counts of RGB stars are converted to total stellar halo luminosity using a suite of isochrones weighted by age and metallicity, and by applying a volume correction based on the stellar halo density profile. Our method is tested and calibrated using Galaxia and N-body models. We find a total luminosity (out to 100 kpc) of $L_{\rm halo} = 7.9 \pm 2.0 \times 10^8\, \mathrm{L}_\odot$ excluding Sgr, and $L_{\rm halo} = 9.4 \pm 2.4 \times 10^8\, \mathrm{L}_\odot$ including Sgr. These values are appropriate for our adopted stellar halo density profile and metallicity distribution, but additional systematics related to these assumptions are quantified and discussed. Assuming a stellar mass-to-light ratio appropriate for a Kroupa initial mass function (M⋆/L = 1.5), we estimate a stellar halo mass of $M^\star _{\rm halo} = 1.4 \pm 0.4\times 10^9 \, \mathrm{M}_\odot$. This mass is larger than previous estimates in the literature, but is in good agreement with the emerging picture that the (inner) stellar halo is dominated by one massive dwarf progenitor. Finally, we argue that the combination of a ${\sim}10^9\, \mathrm{M}_\odot$ mass and an average metallicity of 〈[Fe/H]〉 ∼ −1.5 for the Galactic halo points to an ancient (∼10 Gyr) merger event.
GPU empowered pipelines for calculating genome-wide kinship matrices with ultra-high dimensional genetic variants and facilitating 1D and 2D GWAS
Authors: Zhang Wenchao , Dai Xinbin , Xu Shizhong , Zhao Patrick X
Published: October 2019

Genome-wide association study (GWAS) is a powerful approach that has revolutionized the field of quantitative genetics. Two-dimensional GWAS that accounts for epistatic genetic effects needs to consider the effects of marker pairs, thus quadratic genetic variants, compared to one-dimensional GWAS that accounts for individual genetic variants. Calculating genome-wide kinship matrices in GWAS that account for relationships among individuals represented by ultra-high dimensional genetic variants is computationally challenging. Fortunately, kinship matrix calculation involves pure matrix operations and the algorithms can be parallelized, particular on graphics processing unit (GPU)-empowered high-performance computing (HPC) architectures. We have devised a new method and two pipelines: KMC1D and KMC2D for kinship matrix calculation with high-dimensional genetic variants, respectively, facilitating 1D and 2D GWAS analyses. We first divide the ultra-high-dimensional markers and marker pairs into successive blocks. We then calculate the kinship matrix for each block and merge together the block-wise kinship matrices to form the genome-wide kinship matrix. All the matrix operations have been parallelized using GPU kernels on our NVIDIA GPU-accelerated server platform. The performance analyses show that the calculation speed of KMC1D and KMC2D can be accelerated by 100–400 times over the conventional CPU-based computing.
Nicotine Standards in the United States
Authors: Stanton Cassandra A , Hatsukami Dorothy K
Published: October 2019

Implications

This Special Issue on nicotine standards in the United States will address many of the questions raised in the Advance Notice of Proposed Rulemaking (ANPRM) through a series of policy commentaries and timely empirical studies across a variety of topic areas within the proposed comprehensive nicotine standards plan. The questions addressed in this issue include: (1) the threshold dose of nicotine (and other constituents) that would lead to minimally addictive cigarettes; (2) the effects of a nicotine product standard in smokers with co-morbidity, youth and young adult smokers, and menthol smokers; (3) a step-down or targeted data approach to reducing nicotine in cigarettes; (4) perceptions and communications about product standards; and (5) requirements associated with the implementation of a nicotine product standard.
Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for high-energy RI beams in the parasitic gas cell
Authors: Sonoda T , Katayama I , Wada M , Iimura H , Sonnenschein V , Iimura S , Takamine A , Rosenbusch M , Kojima T M , Ahn D S , Fukuda N , Kubo T , Nishimura S , Shimizu Y , Suzuki H , Takeda H , Tanigaki M , Tomita H , Yoshida K , Ishiyama H
Published: October 2019

An in-flight separator performs the important role of separating a single specific radioactive isotope (RI) beam from the thousands of RI beams produced by in-flight fission as well as projectile fragmentation. However, when looking at ``separation'' from a different viewpoint, more than 99% of simultaneously produced RI beams are just eliminated in the focal plane slits or elsewhere in the separator. In order to enhance the effective usability of the RIKEN in-flight separator BigRIPS, we have been developing an innovative method: parasitic laser ion source (PALIS), which implements parasitic low-energy RI beam production by saving eliminated RI beams during BigRIPS experiments. In this paper, we present the expected benefits and feasibility for the PALIS concept and the results of the first stopping examination for high-energy RI beams in the gas cell.
Headteachers’ and chairs of governors’ perspectives on adolescent obesity and its prevention in English secondary school settings
Authors: Booth E , Halliday V , Cooper R J
Published: October 2019

Background

Secondary schools are an important setting for preventing obesity in adolescence. Headteachers and chairs of governors are identified in national guidance as crucial stakeholders for school-based preventative action. Despite this, their views remain unexplored and unrepresented.

Methods

A sequential mixed method study was conducted. Semi-structured interviews were undertaken with a purposive sample of 22 secondary school headteachers and chairs of governors in England. Data were thematically analysed and informed the development of a descriptive cross-sectional survey, completed by 127 participants from the same population.

Results

Unhealthy dietary and sedentary behaviours were viewed as a more significant problem than adolescent obesity. Obesity was perceived as complex and multi-causal, and a range of stakeholders were deemed to have responsibility for its prevention, most notably parents. Support was identified for the role of secondary schools, although this was not an explicit priority and extensive internal and external barriers exist, which hinder preventative action.

Conclusions

Whilst secondary school settings in England remain an important setting for the prevention of adolescent obesity, it is crucial for policy makers and public health professionals to recognize the factors affecting school leaders’ ability and willingness to contribute to this agenda.
Further insights in the Tardigrada microbiome: phylogenetic position and prevalence of infection of four new Alphaproteobacteria putative endosymbionts
Authors: Guidetti Roberto , Vecchi Matteo , Ferrari Agnese , Newton Irene L G , Cesari Michele , Rebecchi Lorena
Published: October 2019

Data from a previous study showed that microbiomes of six tardigrade species are species-specific and distinct from associated environmental microbes. We here performed a more in-depth analyses of those data, to identify and characterize new potential symbionts. The most abundant bacterial operational taxonomic units (OTUs) found in tardigrades are classified, and their prevalence in other environments is assessed using public databases. A subset of OTUs was selected for molecular phylogenetic analyses based on their affiliation with host-associated bacterial families in tardigrades. Almost 22.6% of the most abundant OTUs found do not match any sequence at 99% identity in the IMNGS database. These novel OTUs include four putative tardigrade endosymbionts from Alphaproteobacteria (Anaplasmataceae and Candidatus Tenuibacteraceae), which are characterized by 16S rRNA gene analysis and investigated for their infection rates in: Echiniscus trisetosus, Richtersisus coronifer and Macrobiotus macrocalix. These putative endosymbionts have an infection prevalence between 9.1% and 40.0%, and are, therefore, likely secondary symbionts, not essential for tardigrade survival and reproduction. Using fluorescence in situ hybridization (FISH), we detected bacteria on the cuticle and within the ovary of E. trisetosus, suggesting possible vertical transmission. This study highlights the great contribution in biodiversity discovery that neglected phyla can provide in microbiome and symbiosis studies.
Improving Care Transitions to Drive Patient Outcomes
Authors: Campagna Vivian , Nelson Sheila A. , Krsnak Jean
Published: October 2019

Purpose:

The purpose of this article is to examine how case managers can support positive outcomes during care transitions by focusing on the goals of the Triple Aim (D. Berwick, T. Nolan, & J. Whittington, 2008) and Coleman's Four Pillars (E. Coleman, C. Parry, S. Chalmers, & S. Min, 2006). Case managers can play a pivotal role to ensure high-quality transitions by assessing patients and identifying those who are at high risk; coordinating care and services among providers and settings; reconciling medications; and facilitating education of patients and their support systems to improve self-management. These activities are congruent with an underlying value of case management as defined by the Code of Professional Conduct for Case Managers: “improving client [i.e., patient] health, wellness and autonomy through advocacy, communication, education, identification of service resources, and service facilitation” (Commission for Case Manager Certification [CCMC], Code, Rev. 2015).

Case Management Primary Practice Settings:

Case managers across health or human services must assess for, identify, and understand the vulnerability of patients during care transitions and must adopt best practices to support successful care transitions. This includes case managers in acute care, primary care, rehabilitation, home health, community-based, and other settings.

Implications for Case Management Practice:

Two frameworks that support care transitions are the Triple Aim of improving the individual's experience of care, advancing the health of populations, and reducing the costs of care (D. Berwick, T. Nolan, & J. Whittington, 2008), and Coleman's “Four Pillars” of care transition activities of medication management, patient-centered health records, follow-up visits with providers and specialists, and patient knowledge about red flags that indicate worsening conditions or drug reactions (E. Coleman, C. Parry, S. Chalmers, & S. Min, 2006). From a case management perspective, these approaches and their goals are interrelated. As an advocate for the individual and at the hub of the care team, the professional case manager engages in important activities such as facilitating communication across multiple providers and care settings, arranging “warm handoffs,” undertaking medication reconciliation, and engaging in follow-up, particularly with high-risk patients. To support successful transitions of care, case managers must adopt best practices and advocate within their organizations for systematic approaches to care transitions to improve outcomes.
Association between CCR5-Δ32 homozygosity and mortality in 37,650 participants from three U.S.-based cohorts
Authors: Jiang Xia , Huang Hongyan , Grodstein Francine , Kraft Peter
Published: October 2019

An analysis of 409,693 UK Biobank participants recently published in Nature Medicine identified a relative 21% increase in all-cause mortality among participants who were homozygous for the Δ32 deletion in the C-C motif chemokine receptor 5 gene (CCR5).1 This is a timely and potentially cautionary result in light of He Jiankui’s controversial germline editing of CCR5 to induce mutations that putatively mimic the effects of Δ32, which is known to reduce the risk of HIV infection. To provide additional evidence on the association between the Δ32 deletion and mortality and assess its generalizability, we present results from three large-scale population-based US cohorts: the Nurses’ Health Study (NHS),2 the NHSII and the Health Professional Follow-Up Study (HPFS).3
Bone morphogenetic protein signaling regulates Id1 mediated neural stem cell quiescence in the adult zebrafish brain via a phylogenetically conserved enhancer module
Authors: Zhang Gaoqun , Ferg Marco , Lübke Luisa , Takamiya Masanari , Beil Tanja , Gourain Victor , Diotel Nicolas , Strähle Uwe , Rastegar Sepand
Published: October 2019

In the telencephalon of adult zebrafish, the inhibitor of DNA binding 1 (id1) gene is expressed in radial glial cells (RGCs), behaving as neural stem cells (NSCs), during constitutive and regenerative neurogenesis. Id1 controls the balance between resting and proliferating states of RGCs by promoting quiescence. Here, we identified a phylogenetically conserved cis-regulatory module (CRM) mediating the specific expression of id1 in RGCs. Systematic deletion mapping and mutation of conserved transcription factor binding sites in stable transgenic zebrafish lines reveal that this CRM operates via conserved smad1/5 and 4 binding motifs (SBMs) under both homeostatic and regenerative conditions. Transcriptome analysis of injured and uninjured telencephala as well as pharmacological inhibition experiments identify a crucial role of bone morphogenetic protein (BMP) signaling for the function of the CRM. Our data highlight that BMP signals control id1 expression and thus NSC proliferation during constitutive and induced neurogenesis.
Deciphering the combinatorial interaction landscape
Authors: Cappuccio Antonio , Jensen Shane T. , Hartmann Boris , Sealfon Stuart C. , Soumelis Vassili , Zaslavsky Elena
Published: October 2019

From cellular activation to drug combinations, the control of biological systems involves multiple stimuli that can elicit complex nonlinear interactions. To elucidate the functions and logic of stimulus interactions, we developed SAIL (Synergistic/Antagonistic Interaction Learner). SAIL uses a machine learning classifier trained to categorize interactions across a complete taxonomy of possible combinatorial effects. The strategy resolves the most informative interactions, and helps infer their functions and regulatory mechanisms. SAIL-predicted interaction mechanisms controlling key immune functions were experimentally validated. SAIL can integrate results from multiple datasets to derive general properties of how cells respond to multiple stimuli. Using public immunological datasets, we assembled a fine-grained landscape of ∼30000 interactions. Analysis of the landscape shows the context-dependent functions of individual modulators, and reveals a probabilistic algebra that links the separate and combined stimulus effects. SAIL is available through a user friendly interface to resolve the effect of stimulus and drug combinations.
The persistence in time of distributional patterns in marine megafauna impacts zonal conservation strategies
Authors: Lambert C. , Dorémus G. , Ridoux V.
Published: October 2019

The main type of zonal conservation approach corresponds to Marine Protected Areas (MPAs), which are spatially defined and generally static entities aiming at the protection of some target populations by the implementation of a management plan. For highly mobile species the relevance of an MPA over time might be hampered by temporal variations in distributions or home ranges. In the present work, we used habitat model-based predicted distributions of cetaceans and seabirds within the Bay of Biscay from 2004 to 2017 to characterise the aggregation and persistence of mobile species distributional patterns and the relevance of the existing MPA network. We explored the relationship between population abundance and spatial extent of distribution to assess the aggregation level of species distribution. We used the smallest spatial extent including 75% of the population present in the Bay of Biscay to define specific core areas of distributions, and calculated their persistence over the 14 studied years. We inspected the relevance of the MPA network with respect to aggregation and persistence. We found that aggregation and persistence are two independent features of marine megafauna distributions. Indeed, strong persistence was shown in both aggregated (bottlenose dolphins, auks) and loosely distributed species (northern gannets), while some species with aggregated distributions also showed limited year-to-year persistence in their patterns (black-legged kittiwakes). We thus have demonstrated that both aggregation and persistence have potential impact on the amount of spatio-temporal distributional variability encompassed within static MPAs. Our results exemplified the need to have access to a minimal temporal depth in the species distribution data when aiming to designate new site boundaries for the conservation of mobile species.
Multistep metabolic engineering ofBacillus licheniformisto improve pulcherriminic acid production
Authors: Wang Shiyi , Wang Huan , Zhang Dan , Li Xiaoyun , Zhang Jin’ge , Zhan Yangyang , Cai Dongbo , Ma Xin , Wang Dong , Chen Shouwen
Published: October 2019

Pulcherriminic acid, a cyclodipeptide, possesses the excellent antibacterial activities by chelating iron ions from environment, however, the low yield has hindered its application. In this study, high-level production of pulcherriminic acid was achieved by the multistep metabolic engineering ofBacillus licheniformisDWc9n*. Firstly, leucine (Leu) supply was increased by overexpressing the genesilvBHC-leuABCDandilvDinvolved in the Leu synthetic pathway and deleting the genebkdABencoding a branched-chain α-keto acid dehydrogenase. The intracellular Leu content and pulcherriminic acid yield of strain W2 reached 147.4 mg/g DCW and 189.9 mg/L respectively, which corresponded to a 226.7% and 49.1% higher than those of DWc9n*. Secondly, the strain W3 was obtained by overexpressing leucyl-tRNA synthase LeuS in W2, which lead to a 190% improvement compared to DWc9n*, pulcherriminic acid yield increase to 367.7 mg/L. Thirdly, overexpression of the cytochrome synthase gene clusteryvmC-cypXfurther increased the yield of pulcherriminic acid to 507.4 mg/L. Finally, the secretion capability was improved by overexpressing the pulcherriminic acid transporter geneyvmA. This resulted in the 556.1 mg/L pulcherriminic acid was produced in W4/pHY-yvmA, increased by 340% as compared with DWc9n*, and it is the highest pulcherriminic acid production currently reported. Taken together, this study provided an efficient strategy for enhancing pulcherriminic acid production and might also be applied for high-level production of other cyclodipeptides.

Importance

Pulcherriminic acid is a cyclodipeptide that derived from cyclo(L-Leu-L-Leu), which has the same iron chelation group with hydroxamate siderophores. Pulcherriminic acid producing strains can inhibit the growths of various bacteria and plant pathogenic fungi. However, the expected pulcherriminic acid yield was not achieved. This study reports efficient microbial production of pulcherriminic acid inBacillus licheniformisDWc9n* via multistep metabolic engineering strategies. The combination of these interventions resulted in the establishment of a pulcherriminic acid overproducing strain. In combination with bioprocess engineering efforts, pulcherriminic acid was produced at a final yield of 556 mg/L in a shake flask. This is the highest pulcherriminic acid yield ever reported so far using rationally engineered microbial cell factories.
Spatiotemporal Maps of Proprioceptive Inputs to the Cervical Spinal Cord During Three-Dimensional Reaching and Grasping
Authors: Kibleur Pierre , Tata Shravan R , Greiner Nathan , Conti Sara , Barra Beatrice , Zhuang Katie , Kaeser Melanie , Ijspeert Auke , Capogrosso Marco
Published: October 2019

Proprioceptive feedback is a critical component of voluntary movement planning and execution. Neuroprosthetic technologies aiming at restoring movement must interact with it to restore accurate motor control. Optimization and design of such technologies depends on the availability of quantitative insights into the neural dynamics of proprioceptive afferents during functional movements. However, recording proprioceptive neural activity during unconstrained movements in clinically relevant animal models presents formidable challenges. In this work, we developed a computational framework to estimate the spatiotemporal patterns of proprioceptive inputs to the cervical spinal cord during three-dimensional arm movements in monkeys. We extended a biomechanical model of the monkey arm with ex-vivo measurements, and combined it with models of mammalian group-Ia, Ib and II afferent fibers. We then used experimental recordings of arm kinematics and muscle activity of two monkeys performing a reaching and grasping task to estimate muscle stretches and forces with computational biomechanics. Finally, we projected the simulated proprioceptive firing rates onto the cervical spinal roots, thus obtaining spatiotemporal maps of spinal proprioceptive inputs during voluntary movements. Estimated maps show complex and markedly distinct patterns of neural activity for each of the fiber populations spanning the spinal cord rostro-caudally. Our results indicate that reproducing the proprioceptive information flow to the cervical spinal cord requires complex spatio-temporal modulation of each spinal root. Our model can support the design of neuroprosthetic technologies as well as in-silico investigations of the primate sensorimotor system.
Spironolactone but not Eplerenone Exacerbates Cisplatin Nephrotoxicity
Authors: Estrela Gabriel R. , Bonnard Benjamin , Barrera-Chimal Jonatan , Jaisser Frédéric
Published: October 2019

Cisplatin is a highly successful chemotherapeutic agent used for the treatment of solid tumors. However, nephrotoxicity is a limiting factor that occurs in 30% of patients under treatment. Many mechanisms are involved in cisplatin-induced nephrotoxicity, such as epithelial and endothelial injury, inflammation, oxidative stress, and renal vasoconstriction. The mineralocorticoid receptor (MR) has an important role in inflammation and vascular function. MR blockage and ablation have been shown to be effective in preventing renal ischemia-reperfusion injury and cyclosporine A-induced nephrotoxicity. We investigated whether MR antagonism with spironolactone or eplerenone could prevent cisplatin-induced nephrotoxicity. Here, we show that spironolactone treatment exacerbates nephrotoxicity in mice treated with acute and long-term cisplatin regimes. Moreover, spironolactone potentiated the toxicity induced by cisplatin treatment in a cell viability assay in human embryonic kidney cells. In contrast, eplerenone neither prevented nor increased cisplatin toxicity in mice or cultured cells. Thus, our studies support recent findings showing that spironolactone potentiates cisplatin-induced cytotoxicity, independently of mineralocorticoid receptor inhibition.
Integration of eye-centered and landmark-centered codes in frontal eye field gaze responses
Authors: Bharmauria Vishal , Sajad Amirsaman , Li Jirui , Yan Xiaogang , Wang Hongying , Crawford J. Douglas
Published: October 2019

The visual system is thought to separate egocentric and allocentric representations, but behavioral experiments show that these codes are optimally integrated to influence goal-directed movements. To test if frontal cortex participates in this integration process, we recorded primate frontal eye field (FEF) activity during a cue-conflict memory delay saccade task. To dissociate egocentric and allocentric coordinates, we surreptitiously shifted a visual landmark during the delay period, causing saccades to deviate by 37% in the same direction. To assess the cellular mechanisms, we fit neural response fields against an egocentric (eye centered target-to-gaze) continuum, and an allocentric shift (eye-to-landmark centered) continuum. Initial visual responses best fit target position. Motor responses (after the landmark shift) predicted future gaze position but embedded within the motor code was a 29% shift toward allocentric coordinates. This shift appeared transiently in memory-related visuomotor activity, and then reappeared in motor activity before saccades. Notably, fits along the egocentric and allocentric shift continua were initially independent, but became correlated just before the motor burst. Overall, these results implicate frontal cortex in the integration of egocentric and allocentric visual information for goal-directed action, and demonstrate the cell-specific, temporal progression of signal multiplexing for this process in the gaze system.
Crystal structure, Hirshfeld surface analysis and physicochemical characterization of bis[4-(dimethylamino)pyridinium] di-μ-chlorido-bis[dichloridomercurate(II)]
Authors: Garci Fatma , Ferjani Hela , Chebbi Hammouda , Ben Jomaa Mariem , Zid Mohamed Faouzi
Published: October 2019

The title molecular salt, (C7H11N2)2[Hg2Cl6], crystallizes with two 4-(dimethylamino)pyridinium cations (AandB) and two half hexachloridodimercurate(II) anions in the asymmetric unit. The organic cations exhibit essentially the same features with an almost planar pyridyl ring (r.m.s. deviations of 0.0028 and 0.0109 Å), which forms an inclined dihedral angle with the dimethyamino group [3.06 (1) and 1.61 (1)°, respectively]. The dimethylamino groups in the two cations are planar, and the C—N bond lengths are shorter than that in 4-(dimethylamino)pyridine. In the crystal, mixed cation–anion layers lying parallel to the (010) plane are formed through N—H...Cl hydrogen bonds and adjacent layers are linked by C—H...Cl hydrogen bonds, forming a three-dimensional network. The analyses of the calculated Hirshfeld surfaces confirm the relevance of the above intermolecular interactions, but also serve to further differentiate the weaker intermolecular interactions formed by the organic cations and inorganic anions, such as π–π and Cl...Cl interactions. The powder XRD data confirms the phase purity of the crystalline sample. Furthermore, the vibrational absorption bands were identified by IR spectroscopy and the optical properties were studied by using optical UV–visible absorption spectroscopy.
Crystal structure and DFT study of a zinc xanthate complex
Authors: Qadir Adnan M. , Kansiz Sevgi , Dege Necmi , Rosair Georgina M. , Fritsky Igor O.
Published: October 2019

In the title compound, bis(2-methoxyethyl xanthato-κS)(N,N,N′,N′-tetramethylethylenediamine-κ2
N,N′)zinc(II) acetone hemisolvate, [Zn(C4H7O2S2)2(C6H16N2)]·0.5C3H6O, the ZnII ion is coordinated by two N atoms of the N,N,N′,N′-tetramethylethylenediamine ligand and two S atoms from two 2-methoxyethyl xanthate ligands. The amine ligand is disordered over two orientations and was modelled with refined occupancies of 0.538 (6) and 0.462 (6). The molecular structure features two C—H...O and two C—H...S intramolecular interactions. In the crystal, molecules are linked by weak C—H...O and C—H...S hydrogen bonds, forming a three-dimensional supramolecular architecture. The molecular structure was optimized using density functional theory (DFT) at the B3LYP/6–311 G(d,p) level. The smallest HOMO–LUMO energy gap (3.19 eV) indicates the suitability of this crystal for optoelectronic applications. The molecular electrostatic potential (MEP) further identifies the positive, negative and neutral electrostatic potential regions of the molecules. Half a molecule of disordered acetone was removed with the solvent-mask procedure in OLEX2 [Dolomanov et al. (2009). J. Appl. Cryst.
42, 339–341] and this contribition is included in the formula.
One-dimensional ladder gallium coordination polymer
Authors: Simões Andrea B. , Figueira Flávio , Mendes Ricardo F. , Barbosa Jéssica S. , Rocha João , Paz Filipe A. Almeida
Published: October 2019

A one-dimensional ladder-type coordination polymer, poly[[(μ2-hydroxido)(μ2-1H-pyrazole-3,5-dicarboxylato)gallium(III)] monohydrate], [Ga(C5H2N2O4)(OH)(H2O)]
n
or [Ga(HPDC)(OH)(H2O)]
n
, I, isotypic with a V3+ coordination polymer previously reported by Chen et al. [J. Coord. Chem. (2008). 61, 3556–3567] was prepared from Ga3+ and pyrazole-3,5-dicarboxylic acid monohydrate (H3PDC·H2O). Compound I was isolated using three distinct experimental methods: hydrothermal (HT), microwave-assisted (MWAS) and one-pot (OP) and the crystallite size should be fine-tuned according to the method employed. The coordination polymeric structure is based on a dimeric Ga3+ moiety comprising two μ2-bridging hydroxide groups, which are interconnected by HPDC2− anionic organic linkers. The close packing of individual polymers is strongly directed by the supramolecular interactions, namely several O—H...O and N—H...O hydrogen-bonding interactions.
A framework for contextualising the formation and transformation of the medina in North Africa
Authors: Abudib Huyam Hadi , Remali Adel Mohammad
Published: October 2019

Purpose

The purpose of this paper is to offer a framework to contextualise the formation and transformation of three major medinas in North Africa, namely, Tripoli, Tunis and Fez. The framework is designed to identify key factors that formed these medinas in the first place, and key causes of transformation in reference to three distinctive forces: colonisation, modernisation and globalisation, which include political, economic and social changes that influenced the transformation process.

Design/methodology/approach

Colonisation, modernisation and globalisation changed the physical appearance and urban fabric, introduced new architectural styles and at the same time changed the social structure, lifestyle, and the inhabitants’ perception and use of spaces within their medinas. Physical aspects of the transformation process are investigated using comparative case studies, while social aspects are studied through interviewing three main actors in housing: users, decision makers and professional architects.

Findings

By identifying key factors of formation and main drivers of transformation, together with analysing the physical and social aspects associated with the transformation process, the framework aims at developing a holistic, complex picture of housing transformation within a specific context: the medinas of North Africa. However, the framework is introduced as a valuable tool for exploring the transformation of other cities with relevant and similar context.

Originality/value

Through the use of comparative case studies and interviews, the study focuses on capturing the essence of traditional medinas, understanding the reality of social change within housing transformation and contextualising the physical aspects of housing transformation.
Confronting extractivism – the role of local struggles in the (un)making of place
Authors: Ehrnström-Fuentes Maria
Published: October 2019

Purpose

The purpose of this paper is to examine the politics involved in local struggles against forestry extractivism. The forestry sector is dependent on vast areas of land for tree plantations. This creates deep-rooted conflicts between global corporations that seek access to natural resources and locals whose way of life requires the use of the same land.

Design/methodology/approach

This study draws on a political ontology frame of reference and storytelling methodology to build on testimonies of three small-scale farmers who actively seek to resist forestry plantations next to their land in rural Uruguay. The stories reveal the impossibilities they face when raising claims in the public political sphere and how they lack the means to organise strong collective resistance.

Findings

One of the testimonies reveals how the farmers engage in a form of “politics of place” (Escobar, 2001, 2008) to counter the power of the proponents of forestry and the further expansion of plantations. This form of politics strengthens and politicises the ontological difference between extractive and non-extractive worlds. The farmers seek to build new imaginations of rural living and sustainable futures without the presence of extractive corporations. They fulfil this aim by designing community projects that aim to revitalise ancient indigenous legends, set up agro-ecological farms, and teach schoolchildren about the environment.

Originality/value

The struggles of the farmers indicate the territorial transformations involved in (un)making (non)extractive places and the need to expand the analysis of the politics involved in struggles against extractivism beyond social struggles.
Structural key factors of participatory sustainability reporting for universities
Authors: Klußmann Coco , Sassen Remmer , Gansel Elisa
Published: October 2019

Purpose

The purpose of this paper is to answer the following research question: What are the key factors of the participatory process for establishing sustainability reporting in German universities?

Design/methodology/approach

To answer the research question, this study uses qualitative methodology, following the grounded theory approach and triangulation of qualitative methods for accessing data.

Findings

The findings show that universities face a high level of difficulty in introducing sustainability reporting, which has an external and an internal dimension.

Originality/value

This paper contributes to the understanding of sustainability reporting processes of universities from an internal perspective, specifically through experts who are involved in the preparation of sustainability reports. Furthermore, it delivers insights for a theory-based discussion, which may support universities in starting sustainability reporting activities and improving reporting processes.
Damage mechanism of giant orthogonal grid barrel vault under strong earthquake
Authors: Qi Lin , Zhang Wenbo , Sun Ronglai , Liu Fang
Published: October 2019

Purpose

Giant orthogonal grid barrel vault is generated by deleting members in the inessential force transfer path of the two-layer lattice barrel vault. Consisting of members in the essential transfer path only, giant orthogonal grid barrel vault is a new type of structure with clear mechanical behavior and efficient material utilization. The paper aims to discuss this issue.

Design/methodology/approach

The geometrical configuration of this structure is analyzed, and the geometrical modeling method is proposed. When necessary parameters are determined, such as the structural span, length, vault rise, longitudinal and lateral giant grid number and section height to top chord length ratio of the lattice member, the structure geometrical model can be generated.

Findings

Numerical models of giant orthogonal grid barrel vaults with different rise–span ratios are built using the member model that can simulate the pre-buckling and post-buckling behavior. So the possible member buckle-straighten process and the plastic hinge form–disappear process of the structure under strong earthquake can be simulated.

Originality/value

Seismic analysis results indicate that when the structure damages under strong earthquake there are a large number of buckling members and few endpoint plastic hinges in the structure. Dynamic damage of giant orthogonal grid barrel vault under strong earthquake is caused by buckling members that weaken the structural bearing capacity.
The impact of country-level and fund-level factors on mutual fund performance in Vietnam
Authors: Nguyen Hoa Thi , Nguyen Dung Thi Nguyet
Published: October 2019

Purpose

The purpose of this paper is to examine the determinants of mutual funds’ performance at both a country level and a fund level in Vietnam.

Design/methodology/approach

The different types of funds with more than three-year operation are selected to remove outliers of the stock market boom from 2015 to 2018. The data set includes 54 mutual funds operating during the period from 2008 until November 2018.

Findings

The research finds that there is a positive relationship between macroeconomics and mutual funds’ performance. Furthermore, country-level governance such as regulation effectiveness, political stability, economic growth and financial development has a positive correlation with mutual funds’ performance. However, the impact of fund-level factors is diverse with the no significant impact of board size on mutual fund’s performance, while passive funds perform better than active funds in Vietnam.

Practical implications

The research results suggest that investors should pay attention to the types of funds and operating expense when making an investment decision in mutual funds. There are some recommendations for both government policy-makers and the mutual fund industry that are likely to facilitate the development of this field in Vietnam.

Originality/value

The research contributes to the understanding of what are the factors that should be considered when investing in mutual funds.
Assessing the health, safety, and environment culture in the United Arab Emirates oil and gas industry
Authors: Almazrouei Mohmaed , Khalid Khalizani , Abdallah Salam , Davidson Ross
Published: October 2019

Purpose

This paper aims to assess the ways through which the concept of health, safety and environment (HSE) is perceived by workers in the United Arab Emirates (UAE) oil and gas industry. The study focused on different aspects of the HSE culture and how employees with and without leadership responsibilities differed in their conceptualization of HSE culture.

Design/methodology/approach

Semi-structured interviews were conducted for 30 staff of the state-owned Abu Dhabi National Oil Company in the UAE. The interviewees were purposively selected which included both those in leadership and non-leadership roles.

Findings

The findings revealed that the interviewees viewed HSE culture as a descriptive term, a causal phenomenon, a systemic approach or a legal requirement/obligation. Interviewees in the production and maintenance units mentioned safety most often. Employees and managers exhibited negligible differences in their usage of the HSE culture concept. Managers predominantly featured in the narratives as important drivers of HSE culture. Physical conditions, behavior and procedures, management, competence and collaboration emerged as important components of a sound HSE culture.

Originality/value

To enable better communication and subsequent improvement of the HSE culture, an analogical HSE culture “vehicle” was developed in the study. The vehicle is a novel illustration based on the key roles of managers and employees, as well as the main components of a sound HSE culture.
WARRN – a formulation-based risk assessment procedure for Child and Adolescent Mental Health Services (CAMHS): the view of clinicians
Authors: Gray Nicola S. , Tiller Jacqui , Snowden Robert J.
Published: October 2019

Purpose

Wales Applied Risk Research Network (WARRN) is a formulation-based technique for the assessment and management of serious risk (e.g. violence to others, suicide, etc.) for users of mental health services which has been adopted across most Child and Adolescent Mental Health Services (CAMHS) across Wales. The paper aims to discuss this issue.

Design/methodology/approach

An online survey was disseminated to National Health Service clinicians in CAMHS to evaluate their perceptions of the use and effectiveness of WARRN. Data from 88 clinicians were analysed with both quantitative and qualitative methods.

Findings

Clinicians reported increased clinical skills, increased confidence in their assessment and management of risk and in safety planning, the increased safety of service users and the general public, and a belief that WARRN had saved lives. The qualitative data showed that clinicians thought a common risk evaluation instrument across Wales and different agencies had created a common language and understanding that improved communication.

Practical implications

WARRN appears well accepted in CAMHS services with the view that it is having a very positive effect on service user well-being and safety and could be implemented in other services.

Originality/value

This is the first report of a formulation-based approach to the management of serious problem behaviours in CAMHS services.