bluuebunny/crossref_metadata_2025 huggingface dataset:
DSmT Decision-Making Algorithms for Finding Grasping Configurations of Robot Dexterous Hands
Authors: Gal Ionel-Alexandru , Bucur Danut , Vladareanu Luige
Published: June 2018

In this paper, we present a deciding technique for robotic dexterous hand configurations. This algorithm can be used to decide on how to configure a robotic hand so it can grasp objects in different scenarios. Receiving as input, several sensor signals that provide information on the object’s shape, the DSmT decision-making algorithm passes the information through several steps before deciding what hand configuration should be used for a certain object and task. The proposed decision-making method for real time control will decrease the feedback time between the command and grasped object, and can be successfully applied on robot dexterous hands. For this, we have used the Dezert–Smarandache theory which can provide information even on contradictory or uncertain systems.
Evolution of ERP Systems in the Cloud: A Study on System Updates
Authors: Bjelland Elise , Haddara Moutaz
Published: June 2018

Cloud-based enterprise resource planning (ERP) systems emerged around the new millennium, and since then there has been a lack of research regarding the evolution and update processes of these systems. From the users’ perspective, updates in a traditional on-premise ERP system are carried at their own request; while cloud-based ERPs are compulsory updated. Through an established ERP lifecycle framework, this study investigates how the process of updates is conducted in a cloud ERP context, from both the users’ and vendors’ perspectives. A multiple case study was conducted in Norway at 10 client organizations, as well as a cloud ERP vendor. Our main findings suggest that the vendor and the users view the process of updates differently. The main challenges with the process of updates from the users’ perspective are the size and date of the updates, lack of information and communication during the process, and extinction of certain functionalities. Yet, the main advantages are that all system users will always have the same version of the system, users do not need to spend time on updating the system and paying attention to the ERP market, which leads to more focus on their core competences instead.
Virological Sampling of Inaccessible Wildlife with Drones
Authors: Geoghegan Jemma L. , Pirotta Vanessa , Harvey Erin , Smith Alastair , Buchmann Jan P. , Ostrowski Martin , Eden John-Sebastian , Harcourt Robert , Holmes Edward C.
Published: June 2018

There is growing interest in characterizing the viromes of diverse mammalian species, particularly in the context of disease emergence. However, little is known about virome diversity in aquatic mammals, in part due to difficulties in sampling. We characterized the virome of the exhaled breath (or blow) of the Eastern Australian humpback whale (Megaptera novaeangliae). To achieve an unbiased survey of virome diversity, a meta-transcriptomic analysis was performed on 19 pooled whale blow samples collected via a purpose-built Unmanned Aerial Vehicle (UAV, or drone) approximately 3 km off the coast of Sydney, Australia during the 2017 winter annual northward migration from Antarctica to northern Australia. To our knowledge, this is the first time that UAVs have been used to sample viruses. Despite the relatively small number of animals surveyed in this initial study, we identified six novel virus species from five viral families. This work demonstrates the potential of UAVs in studies of virus disease, diversity, and evolution.
Variation in the Reported Management of Canine Prolapsed Nictitans Gland and Feline Herpetic Keratitis
Authors: White Constance N. , Jones Gareth , Baker Sarah , Dean Rachel S. , Brennan Marnie L.
Published: June 2018

Treatment variation in medicine may be driven by evidence gaps, clinician factors, and patient preferences. Although well-documented in human medicine, variation in clinical management is relatively unexplored in veterinary practice. Clinical vignette questionnaires were administered to a cross section of general practitioners (GPs) and veterinarians with postgraduate training in ophthalmology (PGs) to survey recommended management of canine prolapsed nictitans gland (“cherry eye”, PNG) and feline herpesvirus (FHV-1) keratitis. The majority of veterinarians (96.2%) suggested surgical replacement of cherry eye, with a pocketing technique being the most frequently nominated procedure. GPs were more likely to suggest gland excision in the event of surgical failure, while PGs more frequently nominated techniques incorporating a periosteal anchor for salvage repair. Most respondents managed FHV-1 keratitis with topical antibiotics (76.4%), with a minority suggesting topical antivirals (32.2%). GPs favoured topical acyclovir whilst PGs more frequently recommended topical trifluorothymidine. A significantly larger proportion of PGs nominated systemic famciclovir and lysine supplement for FHV-1 keratitis. This survey revealed moderate treatment variation for these conditions, both between and within practitioner groups. Additional research is needed to assess the reasons for this variation, particularly for conditions in which high quality evidence is scant.
Impacts of Climate Change on Soil Erosion in the Great Lakes Region
Authors: Wang Lili , Cherkauer Keith , Flanagan Dennis
Published: June 2018

Quantifying changes in potential soil erosion under projections of changing climate is important for the sustainable management of land resources, as soil loss estimates will be helpful in identifying areas susceptible to erosion, targeting future erosion control efforts, and/or conservation funding. Therefore, the macro-scale Variable Infiltration Capacity—Water Erosion Prediction Project (VIC-WEPP) soil erosion model was utilized to quantify soil losses under three climate change scenarios (A2, A1B, B1) using projections from three general circulation models (GFDL, PCM, HadCM3) for the Great Lakes region from 2000 to 2100. Soil loss was predicted to decrease throughout three future periods (2030s, 2060s, and 2090s) by 0.4–0.7 ton ha−1 year−1 (4.99–23.2%) relative to the historical period (2000s) with predicted air temperature increases of 0.68–4.34 °C and precipitation increases of 1.74–63.7 mm year−1 (0.23–8.6%). In the forested northern study domain erosion kept increasing by 0.01–0.18 ton ha−1 year−1 over three future periods due to increased precipitation of 9.7–68.3 mm year−1. The southern study domain covered by cropland and grassland had predicted soil loss decreases of 0.01–1.43 ton ha−1 year−1 due to air temperature increases of 1.75–4.79 °C and reduced precipitation in the summer. Fall and winter had greater risks of increased soil loss based on predictions for these two seasons under the A2 scenario, with the greatest cropland soil loss increase due to increased fall precipitation, and combined effects of increases in both precipitation and air temperature in the winter. Fall was identified with higher risks under the A1B scenario, while spring and summer were identified with the greatest risk of increased soil losses under the B1 scenario due to the increases in both precipitation and air temperature.
Spatial and Temporal Variations of Precipitation Extremes and Seasonality over China from 1961~2013
Authors: Tao Yiyuan , Wang Wen , Song Shuang , Ma Jun
Published: June 2018

Using the 0.5° × 0.5° gridded Chinese ground precipitation dataset from 1961~2013, spatial and temporal variations in precipitation extremes, total precipitation, the seasonality of precipitation and their linkages in the context of climate change are investigated using the Mann-Kendall trend test, Pettitt change-point test and correlation analysis. The investigation focuses on four extreme indices, i.e., the annual maximum number of consecutive dry days (CDD), the annual maximum number of consecutive wet days (CWD), the annual total precipitation when daily precipitation is greater than 95th percentile (R95pTOT), and the maximum 1-day precipitation (RX1day). The results show that precipitation extremes increased in northwestern China, especially Xinjiang, Tibet and Qinghai (CWD, R95pTOT and RX1day), and scattered parts of southeastern China (R95pTOT and RX1day), but decreased over considerable parts of southwestern China (CWD) and some small parts of northern China (CWD, R95pTOT and RX1day); the spatial patterns of the trends in precipitation extremes and that of total precipitation exhibit considerable similarity over China, which indicates the close relationship between changes in precipitation extremes and total precipitation; change points are detected in different periods ranging from early 1970s to early 2000s for different regions and extreme precipitation indices, and the spatial patterns of the abrupt changes of extreme indices are similar to those of the trends in extreme indices; the concentration index (CI) is strongly positively correlated with R95pTOT and RX1day in most areas in northern China (from the northeast to the northwest) and southwestern China (including Sichuan, Chongqing Guizhou and Guangxi), which means for these regions, the temporal heterogeneity of daily precipitation over a year is dominated by heavy rainfall amounts. The seasonality index of precipitation (SI) is positively related to R95pTOT and RX1day over most areas above 30° N, indicating that heavy precipitation events have a better chance to occur in places with a strong seasonal variation in annual precipitation in these areas, but for most areas below 30° N, the positive relationship is not significant.
Problemshed or Watershed? Participatory Modeling towards IWRM in North Ghana
Authors: Daré William’s , Venot Jean-Philippe , Le Page Christophe , Aduna Aaron
Published: June 2018

This paper is a reflexive analysis of a three-year participatory water research project conducted in the Upper East Region (UER) of Ghana, whose explicit objective was to initiate a multi-level dialogue to support the national Integrated Water Resources Management (IWRM) policy framework. The transdisciplinary team adopted the Companion Modeling approach (ComMod), using role-playing games and a computerized agent-based model to support the identification of a problemshed centered on issues of river bank cultivation, erosion, and flooding, and initiate a multi-level dialogue on ways that this problemshed could be tackled. On the basis of this experience, we identify three key criteria for transdisciplinary research to support innovative water governance: (1) the iterative adaptation of tools and facilitation techniques based on feedback from participants; (2) a common understanding of the objectives pursued and the approach used among researchers, who need to explicit their posture, and crucially; (3) the co-identification of a problemshed that diverse stakeholders are interested in tackling. Finally, we argue that the context in which research is funded and conducted in the development sector constitutes a challenge for researchers to be “participants like any other” in the projects they coordinate, which constitutes a barrier to true transdisciplinarity.
Applying the Theory of Reliability to the Assessment of Hazard, Risk and Safety in a Hydrologic System: A Case Study in the Upper Sola River Catchment, Poland
Authors: Ozga-Zielinski Bogdan , Adamowski Jan , Ciupak Maurycy
Published: June 2018

River basin safety issues and hazards arising from extreme hydrological and meteorological events pose significant risks to human life and can entail economic and financial losses. In this study, the practical aspects of reliability theory linked to reliability engineering, and the associated mathematical tools used to describe technical systems, were applied to explore the structural reliability of a quasi-natural system—a portion of the Upper Sola River catchment in Poland. As part of this study, methods such as the Fault Tree Method (FTM), Event Tree Method (ETM), Risk Matrix and Ranking Method for assessing hazard, risk and losses connected with the occurrence of such events are suggested to improve flood risk management and enhance the capacity to safeguard against such events by improving current flood protection protocols in accordance with EC Flood Directives.
Stakeholder Engagement in Maritime Spatial Planning: The Efficacy of a Serious Game Approach
Authors: Keijser Xander , Ripken Malena , Mayer Igor , Warmelink Harald , Abspoel Lodewijk , Fairgrieve Rhona , Paris Crawford
Published: June 2018

The 2014 EU Directive on Maritime Spatial Planning (MSP) lays down obligations for the EU Member States to establish a maritime planning process, resulting in a maritime spatial plan by 2020. Consultation should be carried out with local, national and transnational stakeholders. Stakeholder engagement in MSP is complex because of the great number and diversity of maritime stakeholders and the unfamiliarity of some of these stakeholders with MSP and its potential impact. To facilitate stakeholder engagement in MSP, the ‘MSP Challenge’ table top strategy game was designed and played as part of several stakeholder events in different European countries. The authors study the efficacy of the game for stakeholder engagement. Background and evaluation data of nineteen game sessions with a total of 310 stakeholders with different backgrounds were collected through post-game surveys. Furthermore, the efficacy of the game for stakeholder engagement processes, organised by competent MSP authorities in Scotland and Belgium, is studied in more detail. The results show that the board game, overall, has been a very efficient and effective way of familiarising a great diversity of stakeholders with MSP and to create meaningful interaction and learning among stakeholders in formal planning processes. However, the case studies also show that contextual factors—the level of familiarity with MSP and participants’ perception to sustainability—influences the efficacy of the game.
Geothermometry and Isotope Geochemistry of CO2-Rich Thermal Waters in Choygan, East Tuva, Russia
Authors: Shestakova Anastasia , Guseva Natalia , Kopylova Yulia , Khvaschevskaya Albina , Polya David , Tokarev Igor
Published: June 2018

The Choygan area of southern Siberia, Russia hosts a variety of CO2-rich thermal mineral and other waters emerging from springs at temperatures between 7 °C and 39 °C. Chemical analyses of the spring waters (n = 33) were carried out to characterise the waters and determine their origin. A continuum of compositions was observed between relatively lower temperature (7 °C) HCO3-Ca-Na dominated waters with relatively low amount of total dissolved solids (TDS) and high Eh, and higher temperature (39 °C) HCO3-Na-Ca dominated waters with higher TDS and lower Eh—this reflects largely conservative mixing of these components between near surface low temperature, oxidising groundwaters and higher temperature, more reducing thermal waters derived from a deeper geothermal reservoir. Stable isotopic data are consistent with all the water ultimately being derived from meteoric water that has undergone varying degrees of isotopic fractionation following evaporation. The inferred δ18O and δ2H isotopic composition of the unfractionationed meteoric waters is lighter than that expected that of mean annual local precipitation, which together with a strong negative correlation between δ18O and the elevation of the sampled discharging springs, suggests recharge at higher elevations (1600 m to 3000 m; average 2600 m). Reservoir temperature, calculated using geothermometers and an analysis of saturation indices of plausible reservoir minerals, ranged from 70 °C to 100 °C at an inferred depth of 2 to 3 km. Not all chemical components were found to follow conservative mixing behaviour. In particular, (i) the CO2 contents of the waters were highly variable, suggesting either varying degrees of degassing and/or near discharge admixture with air, and (ii) SO4 concentrations in the lower temperature thermal CO2-rich waters were highly variable, suggesting a role of near surface oxidation processes, for example of pyrite, in modifying the concentration of redox sensitive components. Limited δ13C data are consistent with the CO2 predominately being derived from dissolution of metamorphic/igneous carbonate minerals in the reservoir. Based on geological conditions, isotope and chemical data, a conceptual circulation model of the Choygan hydrothermal system is proposed.
Sulfur-, nitrogen- and platinum-doped titania thin films with high catalytic efficiency under visible-light illumination
Authors: Žener Boštjan , Matoh Lev , Carraro Giorgio , Miljević Bojan , Cerc Korošec Romana
Published: June 2018

Titanium dioxide photocatalysts have received a lot of attention during the past decades due to their ability to degrade various organic pollutants to CO2 and H2O, which makes them suitable for use in environmental related fields such as air and water treatment and self-cleaning surfaces. In this work, titania thin films and powders were prepared by a particulate sol–gel route, using titanium tetrachloride (TiCl4) as a precursor. Afterwards, the prepared sols were doped with nitrogen (ammonium nitrate, urea), sulfur (thiourea) and platinum (chloroplatinic acid), coated onto glass substrates by dip-coating, and thermally treated in a muffle furnace to promote crystallization. The resulting thin films were then characterized by various techniques (i.e., TGA-DSC-MS, XRD, BET, XPS, SEM, band gap measurements). The photocatalytic activity of the prepared thin films was determined by measuring the degradation rate of plasmocorinth B (PB), an organic pigment used in the textile industry, which can pose an environmental risk when expelled into wastewater. A kinetic model for adsorption and subsequent degradation was used to fit the experimental data. The results have shown an increase in photocatalytic activity under visible-light illumination of nonmetal and metal doped and co-doped titania thin films compared to an undoped sample.
INSTITUTIONAL STRENGTH, PEACEBUILDING, AND PRODUCTIVE ENTREPRENEURSHIP - EXPLORATORY ANALYSIS IN COLOMBIA
Authors: Cortés-Sánchez Julián David
Published: June 2018

After more than half a century of armed conflict, Colombia is moving towards a post-conflict period. National and regional strategies aimed to strengthen institutional capacities, promote productive entrepreneurship and reduce organized violence and crime, are crucial lines of action for the alleviation of current (and future) grievances among ex-combatants, and Colombian society in general. This study presents an exploratory analysis on institutional strength, peacebuilding, and productive entrepreneurship in Colombia. Three composite indices based upon international assessments or seminal studies were developed, namely: Institutional Strength Index; Building Peace Index (based on the Negative Peace Index and Positive Peace Index); and Productive Entrepreneurship Index. The results showed a significant correlation between Institutional Strength Index and Productive Entrepreneurship Index. Population is the variable with the most significant correlation with productive entrepreneurship, employment, GDP, industrial sophistication, innovation, crime and certain types of violence (sexual and domestic).
PRIORITIZATION OF THE LAUNCH OF ICT PRODUCTS AND SERVICES THROUGH LINGUISTIC MULTI-CRITERIA DECISION-MAKING
Authors: CID-LÓPEZ Andr´es , HORNOS Miguel J. , CARRASCO-GÓNZÁLEZ Ram´on A. , HERRERA-VIEDMA Enrique
Published: June 2018

The market launch of new products and services is a basic pillar for large and medium-sized companies in the ICT (Information and Communications Technology) sector. Choosing the right moment for it is usually a differentiating factor in terms of competition, since it is a source of competitive advantage. There are several mechanisms and strategies to address this problem from the market perspective. However, the criteria of the different actors involved – managers, sales representatives, experts, etc. – coexist in the corporate sphere and they often differ, causing difficulties in priority setting processes in the launch of a product or service. The assessment of the prioritization of these criteria is usually expressed in natural language, thus adding a great deal of uncertainty. Fuzzy linguistic models have proved to be an efficient tool for managing the intrinsic uncertainty of this type of information. This paper presents a linguistic multi-criteria decision-making model, able to reconcile the different requirements and viewpoints existing in the corporate sector when planning the launch of new products and services. The proposed model is based on the fuzzy 2-tuple linguistic model, aimed at managing linguistic data expressing different corporate criteria, without compromising accuracy in the calculation of said data. In order to illustrate this, a practical case study is presented, in which the model is applied for scheduling the launch prioritization of several new products and services by a telecommunications company, within the deadlines set in its strategic planning.
Exo-Milankovitch Cycles. II. Climates of G-dwarf Planets in Dynamically Hot Systems
Authors: Deitrick Russell , Barnes Rory , Bitz Cecilia , Fleming David , Charnay Benjamin , Meadows Victoria , Wilhelm Caitlyn , Armstrong John , Quinn Thomas R.
Published: June 2018

Using an energy balance model with ice sheets, we examine the climate response of an Earth-like planet orbiting a G-dwarf star and experiencing large orbital and obliquity variations. We find that ice caps couple strongly to the orbital forcing, leading to extreme ice ages. In contrast with previous studies, we find that such exo-Milankovitch cycles tend to impair habitability by inducing snowball states within the habitable zone. The large amplitude changes in obliquity and eccentricity cause the ice edge, the lowest-latitude extent of the ice caps, to become unstable and grow to the equator. We apply an analytical theory of the ice edge latitude to show that obliquity is the primary driver of the instability. The thermal inertia of the ice sheets and the spectral energy distribution of the G-dwarf star increase the sensitivity of the model to triggering runaway glaciation. Finally, we apply a machine learning algorithm to demonstrate how this technique can be used to extend the power of climate models. This work illustrates the importance of orbital evolution for habitability in dynamically rich planetary systems. We emphasize that as potentially habitable planets are discovered around G dwarfs, we need to consider orbital dynamics.
A Window on the Earliest Star Formation: Extreme Photoionization Conditions of a High-ionization, Low-metallicity Lensed Galaxy at z ∼ 2*
Authors: Berg Danielle A. , Erb Dawn K. , Auger Matthew W. , Pettini Max , Brammer Gabriel B.
Published: June 2018

We report new observations of SL2S J021737–051329, a lens system consisting of a bright arc at z = 1.84435, magnified ∼17× by a massive galaxy at z = 0.65. SL2S0217 is a low-mass (M < 109
M
⊙), low-metallicity (Z ∼ 1/20 Z
⊙) galaxy, with extreme star-forming conditions that produce strong nebular UV emission lines in the absence of any apparent outflows. Here we present several notable features from rest-frame UV Keck/LRIS spectroscopy: (1) Very strong narrow emission lines are measured for C iv λλ1548, 1550, He ii λ1640, O iii] λλ1661, 1666, Si iii] λλ1883, 1892, and C iii] λλ1907, 1909. (2) Double-peaked Lyα emission is observed with a dominant blue peak and centered near the systemic velocity. (3) The low- and high-ionization absorption features indicate very little or no outflowing gas along the sight line to the lensed galaxy. The relative emission-line strengths can be reproduced with a very high ionization, low-metallicity starburst with binaries, with the exception of He ii, which indicates that an additional ionization source is needed. We rule out large contributions from active galactic nuclei and shocks to the photoionization budget, suggesting that the emission features requiring the hardest radiation field likely result from extreme stellar populations that are beyond the capabilities of current models. Therefore, SL2S0217 serves as a template for the extreme conditions that are important for reionization and thought to be more common in the early universe.
GRB 120729A: External Shock Origin for Both the Prompt Gamma-Ray Emission and Afterglow
Authors: Huang Li-Ye , Wang Xiang-Gao , Zheng WeiKang , Liang En-Wei , Lin Da-bin , Zhong Shu-Qing , Zhang Hai-Ming , Huang Xiao-Li , Filippenko Alexei V. , Zhang Bing
Published: June 2018

Gamma-ray burst (GRB) 120729A was detected by Swift/BAT and Fermi/GBM, and then rapidly observed by Swift/XRT, Swift/UVOT, and ground-based telescopes. It had a single long and smooth γ-ray emission pulse, which extends continuously to the X-rays. We report Lick/KAIT observations of the source, and make temporal and spectral joint fits of the multiwavelength light curves of GRB 120729A. It exhibits achromatic light-curve behavior, consistent with the predictions of the external shock model. The light curves are decomposed into four typical phases: onset bump (Phase I), normal decay (Phase II), shallow decay (Phase III), and post-jet break (Phase IV). The spectral energy distribution (SED) evolves from prompt γ-ray emission to the afterglow with a photon index from Γ
γ
 = 1.36 to Γ ≈ 1.75. There is no obvious evolution of the SED during the afterglow. The multiwavelength light curves from γ-ray to optical can be well modeled with an external shock by considering energy injection, and a time-dependent microphysics model with

ϵ

B

∝

t

α

B

for the emission at early times,

T
<

T

0

+
157

s

. Therefore, we conclude that both the prompt γ-ray emission and afterglow of GRB 120729A have the same external shock physical origin. Our model indicates that the ϵ

B
evolution can be described as a broken power-law function with α

B,1 = 0.18 ± 0.04 and α

B,2 = 0.84 ± 0.04. We also systematically investigate single-pulse GRBs in the Swift era, finding that only a small fraction of GRBs (GRBs 120729A, 051111, and 070318) are likely to originate from an external shock for both the prompt γ-ray emission and afterglow.
The Anatomy of the Column Density Probability Distribution Function (N-PDF)
Authors: Chen Hope How-Huan , Burkhart Blakesley , Goodman Alyssa , Collins David C.
Published: June 2018

The column density probability distribution function (N-PDF) of Giant Molecular Clouds (GMCs) has been used as a diagnostic of star formation. Simulations and analytic predictions have suggested that the N-PDF is composed of a low-density lognormal component and a high-density power-law component tracing turbulence and gravitational collapse, respectively. In this paper, we study how various properties of the true 2D column density distribution create the shape, or “anatomy,” of the PDF. We test our ideas and analytic approaches using both a real, observed PDF based on Herschel observations of dust emission and a simulation that uses the ENZO code. Using a dendrogram analysis, we examine the three main components of the N-PDF: the lognormal component, the power-law component, and the transition point between these two components. We find that the power-law component of an N-PDF is the summation of N-PDFs of power-law substructures identified by the dendrogram algorithm. We also find that the analytic solution to the transition point between lognormal and power-law components proposed by Burkhart et al. is applicable when tested on observations and simulations, within the uncertainties. Based on the resulting anatomy of the N-PDF, we suggest applying the N-PDF analysis in combination with the dendrogram algorithm to obtain a more complete picture of the global and local environments and their effects on the density structures.
Small-scale Dynamo Simulations: Magnetic Field Amplification in Exploding Granules and the Role of Deep and Shallow Recirculation
Authors: Rempel M.
Published: June 2018

We analyze recent high-resolution photospheric small-scale dynamo simulations that were computed with the MURaM radiative MHD code. We focus our analysis on newly forming downflow lanes in exploding granules, as they show how weakly magnetized regions in the photosphere (the center of granules) evolve into strongly magnetized regions (downflow lanes). We find that newly formed downflow lanes initially exhibit mostly a laminar converging flow that amplifies the vertical magnetic field embedded in the granule from a few 10 G to field strengths exceeding 800 G. This results in extended magnetic sheets that have a length comparable to granular scales. Field amplification by turbulent shear first happens a few 100 km beneath the visible layers of the photosphere. Shallow recirculation transports the resulting turbulent field into the photosphere within minutes, after which the newly formed downflow lane shows a mix of strong magnetic sheets and turbulent field components. We stress in particular the role of shallow and deep recirculation for the organization and strength of magnetic field in the photosphere and discuss the photospheric and sub-photospheric energy conversion associated with the small-scale dynamo process. While the energy conversion through the Lorentz force depends only weakly on the saturation field strength (and therefore deep or shallow recirculation), it is strongly dependent on the magnetic Prandtl number. We discuss the potential of these findings for further constraining small-scale dynamo models through high-resolution observations.
Gamma-Ray Burst Jet Breaks Revisited
Authors: Wang Xiang-Gao , Zhang Bing , Liang En-Wei , Lu Rui-Jing , Lin Da-Bin , Li Jing , Li Long
Published: June 2018

Gamma-ray Burst (GRB) collimation has been inferred with the observations of achromatic steepening in GRB light curves, known as jet breaks. Identifying a jet break from a GRB afterglow light curve allows a measurement of the jet opening angle and true energetics of GRBs. In this paper, we re-investigate this problem using a large sample of GRBs that have an optical jet break that is consistent with being achromatic in the X-ray band. Our sample includes 99 GRBs from 1997 February to 2015 March that have optical and, for Swift GRBs, X-ray light curves that are consistent with the jet break interpretation. Out of the 99 GRBs we have studied, 55 GRBs are found to have temporal and spectral behaviors both before and after the break, consistent with the theoretical predictions of the jet break models, respectively. These include 53 long/soft (Type II) and 2 short/hard (Type I) GRBs. Only 1 GRB is classified as the candidate of a jet break with energy injection. Another 41 and 3 GRBs are classified as the candidates with the lower and upper limits of the jet break time, respectively. Most jet breaks occur at 90 ks, with a typical opening angle θ

j
 = (2.5 ± 1.0)°. This gives a typical beaming correction factor

f

b

−
1

∼
1000

for Type II GRBs, suggesting an even higher total GRB event rate density in the universe. Both isotropic and jet-corrected energies have a wide span in their distributions: log(E

γ,iso/erg) = 53.11 with σ = 0.84; log(E
K,iso/erg) = 54.82 with σ = 0.56; log(E

γ
/erg) = 49.54 with σ = 1.29; and log(E
K/erg) = 51.33 with σ = 0.58. We also investigate several empirical correlations (Amati, Frail, Ghirlanda, and Liang–Zhang) previously discussed in the literature. We find that in general most of these relations are less tight than before. The existence of early jet breaks and hence small opening angle jets, which were detected in the Swfit era, is most likely the source of scatter. If one limits the sample to jet breaks later than 104 s, the Liang–Zhang relation remains tight and the Ghirlanda relation still exists. These relations are derived from Type II GRBs, and Type I GRBs usually deviate from them.
Effects of Anomalous Cosmic Rays on the Structure of the Outer Heliosphere
Authors: Guo Xiaocheng , Florinski Vladimir , Wang Chi
Published: June 2018

Based on Voyager 1 observations, some anomalous cosmic rays (ACRs) may have crossed the heliopause and escaped into the interstellar medium, providing a mechanism of energy transfer between the inner and outer heliosheaths that is not included in conventional magnetohydrodynamics (MHD) models. In this paper, we study the effect of energetic particles’ escape through the heliopause on the size and shape of the heliosphere using a simple model that includes diffusive transport of cosmic rays. We show that the presence of ACRs significantly changes the heliosphere structure, including the location of the heliopause and termination shock. It was found that the heliopause would contract for certain values of the ACR diffusion coefficients when the diffusive particles’ pressure is comparable to the pressure of the plasma background. The difference in Voyager 1 and 2 observations of energetic particles during their respective termination shock crossings is interpreted here as due to the differences in diffusion environments during the different phases of the solar cycle. The shorter period of enhanced ACR intensities upstream of the shock measured by Voyager 2 may have been caused by weaker radial diffusive transport compared with the time of Voyager 1 crossing. We conclude that ACR diffusive effects could be prominent and should be included in MHD models of the heliosphere.
The First Empirical Determination of the Fe10+ and Fe13+ Freeze-in Distances in the Solar Corona
Authors: Boe Benjamin , Habbal Shadia , Druckmüller Miloslav , Landi Enrico , Kourkchi Ehsan , Ding Adalbert , Starha Pavel , Hutton Joseph
Published: June 2018

Heavy ions are markers of the physical processes responsible for the density and temperature distribution throughout the fine-scale magnetic structures that define the shape of the solar corona. One of their properties, whose empirical determination has remained elusive, is the “freeze-in” distance (R

f
) where they reach fixed ionization states that are adhered to during their expansion with the solar wind. We present the first empirical inference of R

f
for

and

derived from multi-wavelength imaging observations of the corresponding Fe xi (

) 789.2 nm and Fe xiv (

) 530.3 nm emission acquired during the 2015 March 20 total solar eclipse. We find that the two ions freeze-in at different heliocentric distances. In polar coronal holes (CHs) R

f
is around 1.45 R
⊙ for

and below 1.25 R
⊙ for

. Along open field lines in streamer regions, R

f
ranges from 1.4 to 2 R
⊙ for

and from 1.5 to 2.2 R
⊙ for

. These first empirical R

f
values: (1) reflect the differing plasma parameters between CHs and streamers and structures within them, including prominences and coronal mass ejections; (2) are well below the currently quoted values derived from empirical model studies; and (3) place doubt on the reliability of plasma diagnostics based on the assumption of ionization equilibrium beyond 1.2 R
⊙.
Fully Kinetic Large-scale Simulations of the Collisionless Magnetorotational Instability
Authors: Inchingolo Giannandrea , Grismayer Thomas , Loureiro Nuno F. , Fonseca Ricardo A. , Silva Luis O.
Published: June 2018

We present two-dimensional particle-in-cell simulations of the fully kinetic collisionless magnetorotational instability (MRI) in weakly magnetized (high β) pair plasma. The central result of this numerical analysis is the emergence of a self-induced turbulent regime in the saturation state of the collisionless MRI, which can only be captured for large enough simulation domains. One of the underlying mechanisms for the development of this turbulent state is the drift-kink instability (DKI) of the current sheets resulting from the nonlinear evolution of the channel modes. The onset of the DKI can only be observed for simulation domain sizes exceeding several linear MRI wavelengths. The DKI and ensuing magnetic reconnection activate the turbulent motion of the plasma in the late stage of the nonlinear evolution of the MRI. At steady-state, the magnetic energy has an MHD-like spectrum with a slope of k
−5/3 for kρ < 1 and k
−3 for sub-Larmor scale (kρ > 1). We also examine the role of the collisionless MRI and associated magnetic reconnection in the development of pressure anisotropy. We study the stability of the system due to this pressure anisotropy, observing the development of mirror instability during the early-stage of the MRI. We further discuss the importance of magnetic reconnection for particle acceleration during the turbulence regime. In particular, consistent with reconnection studies, we show that at late times the kinetic energy presents a characteristic slope of ϵ
−2 in the high-energy region.
The Structure of a Quasi-Keplerian Accretion Disk around Magnetized Stars
Authors: Habumugisha Isaac , Jurua Edward , Tessema Solomon B. , Simon Anguma K.
Published: June 2018

In this paper, we present the complete structure of a quasi-Keplerian thin accretion disk with an internal dynamo around a magnetized neutron star. We assume a full quasi-Keplerian disk with the azimuthal velocity deviating from the Keplerian fashion by a factor of ξ (0 < ξ < 2). In our approach, we vertically integrate the radial component of the momentum equation to obtain the radial pressure gradient equation for a thin quasi-Keplerian accretion disk. Our results show that, at large radial distance, the accretion disk behaves in a Keplerian fashion. However, close to the neutron star, pressure gradient force (PGF) largely modifies the disk structure, resulting into sudden dynamical changes in the accretion disk. The corotation radius is shifted inward (outward) for ξ > 1 (for ξ < 1), and the position of the inner edge with respect to the new corotation radius is also relocated accordingly, as compared to the Keplerian model. The resulting PGF torque couples with viscous torque (when ξ < 1) to provide a spin-down torque and a spin-up torque (when ξ > 1) while in the advective state. Therefore, neglecting the PGF, as has been the case in previous models, is a glaring omission. Our result has the potential to explain the observable dynamic consequences of accretion disks around magnetized neutron stars.
Nano-indentation of native phytoliths and dental tissues: implications for herbivore-plant combat and dental wear proxies
Authors: Kaiser Thomas M. , Braune Caroline , Kalinka Gerhard , Schulz-Kornas Ellen
Published: June 2018

Tooth wear induced by abrasive particles is a key process affecting dental function and life expectancy in mammals. Abrasive particles may be plant endogenous opal phytoliths, exogene wind-blown quartz dust or rain borne mineral particles ingested by mammals. Nano-indentation hardness of abrasive particles and dental tissues is a significant yet not fully established parameter of this tribological system. We provide consistent nano-indentation hardness data for some of the major antagonists in the dental tribosystem (tooth enamel, tooth dentine and opaline phytoliths from silica controlled cultivation). All indentation data were gathered from native tissues under stable and controlled conditions and thus maximize comparability to natural systems. Here we show that native (hydrated) wild boar enamel exceeds any hardness measures known for dry herbivore tooth enamel by at least 3 GPa. The native tooth enamel is not necessarily softer then environmental quartz grit, although there is little overlap. The native hardness of the tooth enamel exceeds that of any silica phytolith hardness recently published. Further, we find that native reed phytoliths equal native suine dentine in hardness, but does not exceed native suine enamel. We also find that native suine enamel is significantly harder than dry enamel and dry phytoliths are harder than native phytoliths. Our data challenge the claim that the culprit of tooth wear may be the food we chew, but suggest instead that wear may relates more to exogenous than endogenous abrasives.
Factors Influencing Clinical Performance of Baccalaureate Nursing Majors: A Retrospective Audit
Authors: Johnston Sandra , Fox Amanda , Coyer Fiona Maree
Published: June 2018

Background:

Transition of nursing student to new graduate depends on successful completion of clinical work placement during an undergraduate course. Supporting students during the clinical placement is imperative. This study examined associations between grade point average, domestic or international status, course entry qualification, and single or dual nursing degree to successful completion of clinical placement.

Method:

A retrospective audit of 665 students in a baccalaureate nursing program was conducted to examine factors influencing clinical performance of baccalaureate nursing students.

Results:

A significant association between entry qualification, lower grade point average, international status, and receipt of a constructive note was found: χ
2
= 8.678,
df
= 3,
p
= .034,
t
(3.862),
df
= 663,
p
⩽ .001, and Fisher's exact test = 8.581,
df
= 1,
p
= .003, respectively.

Conclusion:

Understanding factors that affect clinical performance may help early identification of students at risk and allow for supportive intervention during placement and subsequent program completion. [
J Nurs Educ.
2018;57(6):333–338.]
Generating Gratitude in the Workplace to Improve Faculty Job Satisfaction
Authors: Stegen Amy , Wankier Jamie
Published: June 2018

Background:

The current nursing shortage affects all settings. In an effort to promote retention of nursing faculty, an “attitude of gratitude” was cultivated to improve job satisfaction and increase collaboration in one school of nursing.

Method:

This was a quantitative study using a convenience sample of faculty at one school of nursing. A presurvey of faculty on perceived gratitude levels and job satisfaction was administered prior to the start of the school year. Multiple gratitude interventions were implemented throughout the year and a postsurvey was administered to measure the effectiveness of interventions.

Results:

The findings of this study show an improvement of 17.9% in overall job satisfaction, which is consistent with other studies on the topic. Collaboration was not affected by gratitude interventions.

Conclusion:

Implementing gratitude is a cost-effective and easy way to improve job satisfaction to increase faculty retention rates. [
J Nurs Educ.
2018;57(6):375–378.]
Phytochemical profile and antioxidant capacity of virgin olive oil obtained from the olive cultivar ‘Roghiani’ from different regions of northern Libya
Authors: Esalami S. M. , Dimic E. B. , Rabrenovic B. B.
Published: June 2018

The aim of this work was to determine the fatty acids (FA), tocopherols, phenols, and antioxidant capacity (AC) of five virgin olive oils (VOO) obtained from the olive cultivar ‘Roghiani’, from different regions of northern Libya during the crop year 2015. The parameters determined for the oils were investigated for the first time. Seven principal FAs were detected in the VOO samples. Oleic, palmitic, and linoleic acids were the dominant ones. The highest percentage of palmitic acid was found in Tripoli VOO (P ≤ 0.05). Oleic acid was dominant in all the VOO samples. Gharyan VOO possessed the highest value of oleic acid, O/L ratio, monounsaturated fatty acids (MUFA), total phenols content (TPC), total tocopherol and tocotrienol contents (TTC), and ACDPPH % (P ≤ 0.05). A strong positive relationship between TPC and (AC) as (1/EC50DPPH) was observed, (r) was +0.831. On the other hand, (1/EC50DPPH) showed a positive correlation with TTC, (r) was +0.768.
DURABILITY PERFORMANCE AND DIMENSIONAL STABILITY OF POLYPROPYLENE FIBER REINFORCED CONCRETE
Authors: Mardani-Aghabaglou Ali , Özen Süleyman , Altun Muhammet Gökhan
Published: June 2018

In this study, the durability performance and dimensional stability of polypropylene fiber reinforced concrete mixture were investigated. For this purpose, two series of concrete mixtures, including a 0.45 water/cement ratio was prepared both in the absence and presence of fiber. A CEMI 42.5 R type portland cement and crushed limestone aggregate with a maximum particle size of 25 mm were used. In addition to the control mixture without fiber, three different concrete mixtures were prepared by adding polypropylene fiber as 0.4%, 0.8% and 1% of total volume into the mixture. The time-dependent fresh state properties, strength, ultrasonic pulse velocity, transport properties, drying shrinkage and freeze-thaw resistance of concrete mixtures, sodium sulfate attack and abrasion were investigated comparatively. Test results demonstrated that utilization of fiber affected the fresh properties of the concrete mixtures negatively. However, the 0.8% fiber-bearing mixture showed the highest performance in terms of durability and dimensional stability. Beyond this utilization ratio, the durability performance of the concrete mixture was negatively affected. The risk of nonhomogeneous dispersion of the fiber in the mixture was relatively high in the excess fiber-bearing mixture. Consequently, with the formation of flocculation in the mixture the void ratio of concrete mixture increased.
CARBON EMISSION-BASED MEASUREMENT OF FLOOR AREA RATIO BONUS FOR RESIDENTIAL GREEN BUILDINGS IN CHINA
Authors: Mao Yanhui , Gong Xuemei , Ye Yun
Published: June 2018

Green building development in China relies mainly on compulsory measures that lack incentive policies to motivate the enthusiasm of real estate developers. A floor area ratio bonus is encouraged by the Chinese State Council. In order to ensure the feasibility of a reward quota, residential buildings that met the requirement for energy efficiency during the official assessment in Ningbo in 2014 were selected as research objects. The amount of energy and water savings in terms of the Assessment Standard for Green Building is converted into carbon emissions. Carbon emissions of different star-rated green buildings are then measured in accordance with the actual water and power consumption of residential dwellings in 2014. A regression equation is set up concerning the floor area ratio and index for residential land per capita. A carbon emission-based method is proposed for measuring the reward quota associated with floor area ratio and recommendations are given for development using green building.
Awareness of Musicians on Ear Protection and Tinnitus: A Preliminary Study
Authors: Dinakaran Tychicus , Deborah D. Ruth , RejoyThadathil Chitra
Published: June 2018

Music induced hearing loss (MIHL) is linked to chronic, extended exposure, and progress at a rate proportionate to exposure conditions. The aim was to document hearing deterioration; awareness of ear protection devices (EPDs); presence of tinnitus, measurement of temporary threshold shift. Thirty-four musicians filled a questionnaire regarding: years of experience, instrument/splayed, hours of music exposure per week with/without amplification, through earphones and speakers, use of EPDs and tinnitus. Hearing screening in five subjects was done before and after one hour and ten minutes of practice session. Among the participants, 8.8% reported hearing deterioration subjectively and 38.2% reported unilateral intermittent tinnitus, 79.4% lacked awareness about EPDs and 21.6 % were aware but never used them. Mean for temporary threshold shift at 500 Hz and 1 KHz was 5dB HL and 10dBHL at 2 KHz. Musicians are at risk for hearing problems, but the awareness on auditory damage is limited, hence conservative measures must be taken for their well being.