bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Annual Landsat Time Series for the Detection of Dry Forest Degradation Processes in South-Central Angola
Authors: Schneibel Anne , Frantz David , Röder Achim , Stellmes Marion , Fischer Kim , Hill Joachim
Published: August 2017

Dry tropical forests undergo massive conversion and degradation processes. This also holds true for the extensive Miombo forests that cover large parts of Southern Africa. While the largest proportional area can be found in Angola, the country still struggles with food shortages, insufficient medical and educational supplies, as well as the ongoing reconstruction of infrastructure after 27 years of civil war. Especially in rural areas, the local population is therefore still heavily dependent on the consumption of natural resources, as well as subsistence agriculture. This leads, on one hand, to large areas of Miombo forests being converted for cultivation purposes, but on the other hand, to degradation processes due to the selective use of forest resources. While forest conversion in south-central rural Angola has already been quantitatively described, information about forest degradation is not yet available. This is due to the history of conflicts and the therewith connected research difficulties, as well as the remote location of this area. We apply an annual time series approach using Landsat data in south-central Angola not only to assess the current degradation status of the Miombo forests, but also to derive past developments reaching back to times of armed conflicts. We use the Disturbance Index based on tasseled cap transformation to exclude external influences like inter-annual variation of rainfall. Based on this time series, linear regression is calculated for forest areas unaffected by conversion, but also for the pre-conversion period of those areas that were used for cultivation purposes during the observation time. Metrics derived from linear regression are used to classify the study area according to their dominant modification processes. We compare our results to MODIS latent integral trends and to further products to derive information on underlying drivers. Around 13% of the Miombo forests are affected by degradation processes, especially along streets, in villages, and close to existing agriculture. However, areas in presumably remote and dense forest areas are also affected to a significant extent. A comparison with MODIS derived fire ignition data shows that they are most likely affected by recurring fires and less by selective timber extraction. We confirm that areas that are used for agriculture are more heavily disturbed by selective use beforehand than those that remain unaffected by conversion. The results can be substantiated by the MODIS latent integral trends and we also show that due to extent and location, the assessment of forest conversion is most likely not sufficient to provide good estimates for the loss of natural resources.
Improving Satellite-Driven PM2.5 Models with VIIRS Nighttime Light Data in the Beijing–Tianjin–Hebei Region, China
Authors: Zhang Xiya , Hu Haibo
Published: August 2017

Previous studies have estimated ground-level concentrations of particulate matter 2.5 (PM2.5) using satellite-derived aerosol optical depth (AOD) in conjunction with meteorological and land use variables. However, the impacts of urbanization on air pollution for predicting PM2.5 are seldom considered. Nighttime light (NTL) data, acquired with the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite, could be useful for predictions because they have been shown to be good indicators of the urbanization and human activity that can affect PM2.5 concentrations. This study investigated the potential of incorporating VIIRS NTL data in statistical models for PM2.5 concentration predictions. We developed a mixed-effects model to derive daily estimations of surface PM2.5 levels in the Beijing–Tianjin–Hebei region using 3 km resolution satellite AOD and VIIRS NTL data. The results showed the addition of NTL information could improve the performance of the PM2.5 prediction model. The NTL data revealed additional details for predication results in areas with low PM2.5 concentrations and greater apparent seasonal variation due to the seasonal variability of human activity. Comparison showed prediction accuracy was improved more substantially for the model using NTL directly than for the model using the vegetation-adjusted NTL urban index that included NTL. Our findings indicate that VIIRS NTL data have potential for predicting PM2.5 and that they could constitute a useful supplemental data source for estimating ground-level PM2.5 distributions.
Three’s Company: An Additional Non-transiting Super-Earth in the Bright HD 3167 System, and Masses for All Three Planets
Authors: Christiansen Jessie L. , Vanderburg Andrew , Burt Jennifer , Fulton B. J. , Batygin Konstantin , Benneke Björn , Brewer John M. , Charbonneau David , Ciardi David R. , Cameron Andrew Collier , Coughlin Jeffrey L. , Crossfield Ian J. M. , Dressing Courtney , Greene Thomas P. , Howard Andrew W. , Latham David W. , Molinari Emilio , Mortier Annelies , Mullally Fergal , Pepe Francesco , Rice Ken , Sinukoff Evan , Sozzetti Alessandro , Thompson Susan E. , Udry Stéphane , Vogt Steven S. , Barman Travis S. , Batalha Natasha E. , Bouchy François , Buchhave Lars A. , Butler R. Paul , Cosentino Rosario , Dupuy Trent J. , Ehrenreich David , Fiorenzano Aldo , Hansen Brad M. S. , Henning Thomas , Hirsch Lea , Holden Bradford P. , Isaacson Howard T. , Johnson John A. , Knutson Heather A. , Kosiarek Molly , López-Morales Mercedes , Lovis Christophe , Malavolta Luca , Mayor Michel , Micela Giuseppina , Motalebi Fatemeh , Petigura Erik , Phillips David F. , Piotto Giampaolo , Rogers Leslie A. , Sasselov Dimitar , Schlieder Joshua E. , Ségransan Damien , Watson Christopher A. , Weiss Lauren M.
Published: August 2017

HD 3167 is a bright (V = 8.9), nearby K0 star observed by the NASA K2 mission (EPIC 220383386), hosting two small, short-period transiting planets. Here we present the results of a multi-site, multi-instrument radial-velocity campaign to characterize the HD 3167 system. The masses of the transiting planets are 5.02 ± 0.38

for HD 3167 b, a hot super-Earth with a likely rocky composition (

=

g cm−3), and

for HD 3167 c, a warm sub-Neptune with a likely substantial volatile complement (

=

g cm−3). We explore the possibility of atmospheric composition analysis and determine that planet c is amenable to transmission spectroscopy measurements, and planet b is a potential thermal emission target. We detect a third, non-transiting planet, HD 3167 d, with a period of 8.509 ± 0.045 d (between planets b and c) and a minimum mass of 6.90 ± 0.71

. We are able to constrain the mutual inclination of planet d with planets b and c: we rule out mutual inclinations below 1.°3 because we do not observe transits of planet d. From 1.°3 to 40°, there are viewing geometries invoking special nodal configurations, which result in planet d not transiting some fraction of the time. From 40° to 60°, Kozai–Lidov oscillations increase the system’s instability, but it can remain stable for up to 100 Myr. Above 60°, the system is unstable. HD 3167 promises to be a fruitful system for further study and a preview of the many exciting systems expected from the upcoming NASA TESS mission.
Properties of the Irregular Satellite System around Uranus Inferred from K2, Herschel, and Spitzer Observations
Authors: Farkas-Takács A. , Kiss Cs. , Pál A. , Molnár L. , Szabó Gy. M. , Hanyecz O. , Sárneczky K. , Szabó R. , Marton G. , Mommert M. , Szakáts R. , Müller T. , Kiss L. L.
Published: August 2017

In this paper, we present visible-range light curves of the irregular Uranian satellites Sycorax, Caliban, Prospero, Ferdinand, and Setebos taken with the Kepler Space Telescope over the course of the K2 mission. Thermal emission measurements obtained with the Herschel/PACS and Spitzer/MIPS instruments of Sycorax and Caliban were also analyzed and used to determine size, albedo, and surface characteristics of these bodies. We compare these properties with the rotational and surface characteristics of irregular satellites in other giant planet systems and also with those of main belt and Trojan asteroids and trans-Neptunian objects. Our results indicate that the Uranian irregular satellite system likely went through a more intense collisional evolution than the irregular satellites of Jupiter and Saturn. Surface characteristics of Uranian irregular satellites seem to resemble the Centaurs and trans-Neptunian objects more than irregular satellites around other giant planets, suggesting the existence of a compositional discontinuity in the young solar system inside the orbit of Uranus.
Observations of the Ultraviolet-bright Star Y453 in the Globular Cluster M4 (NGC 6121)
Authors: Dixon William V. , Chayer Pierre , Latour Marilyn , Bertolami Marcelo Miguel Miller , Benjamin Robert A.
Published: August 2017

We present a spectral analysis of the UV-bright star Y453 in M4. Model fits to the star’s optical spectrum yield

 ∼ 56,000 K. Fits to the star’s FUV spectrum, obtained with the Cosmic Origins Spectrograph on board the Hubble Space Telescope, reveal it to be considerably hotter, with

 ∼ 72,000 K. We adopt

 = 72,000 ± 2000 K and

 = 5.7 ± 0.2 as our best-fit parameters. Scaling the model spectrum to match the star’s optical and near-infrared magnitudes, we derive a mass

and luminosity

, consistent with the values expected of an evolved star in a globular cluster. Comparing the star with post-horizontal-branch evolutionary tracks, we conclude that it most likely evolved from the blue horizontal branch, departing the asymptotic giant branch before third dredge-up. It should thus exhibit the abundance pattern (O-poor and Na-rich) characteristic of the second-generation (SG) stars in M4. We derive the star’s photospheric abundances of He, C, N, O, Si, S, Ti, Cr, Fe, and Ni. CNO abundances are roughly 0.25 dex greater than those of the cluster’s SG stars, while the Si and S abundances match the cluster values. Abundances of the iron-peak elements (except for iron itself) are enhanced by 1–3 dex. Rather than revealing the star’s origin and evolution, this pattern reflects the combined effects of diffusive and mechanical processes in the stellar atmosphere.
Modifying the Standard Disk Model for the Ultraviolet Spectral Analysis of Disk-dominated Cataclysmic Variables. I. The Novalikes MV Lyrae, BZ Camelopardalis, and V592 Cassiopeiae
Authors: Godon Patrick , Sion Edward M. , Balman Şölen , Blair William P.
Published: August 2017

The standard disk is often inadequate to model disk-dominated cataclysmic variables (CVs) and generates a spectrum that is bluer than the observed UV spectra. X-ray observations of these systems reveal an optically thin boundary layer (BL) expected to appear as an inner hole in the disk. Consequently, we truncate the inner disk. However, instead of removing the inner disk, we impose the no-shear boundary condition at the truncation radius, thereby lowering the disk temperature and generating a spectrum that better fits the UV data. With our modified disk, we analyze the archival UV spectra of three novalikes that cannot be fitted with standard disks. For the VY Scl systems MV Lyr and BZ Cam, we fit a hot inflated white dwarf (WD) with a cold modified disk (

a few 10−9
M
⊙ yr−1). For V592 Cas, the slightly modified disk (

) completely dominates the UV. These results are consistent with Swift X-ray observations of these systems, revealing BLs merged with ADAF-like flows and/or hot coronae, where the advection of energy is likely launching an outflow and heating the WD, thereby explaining the high WD temperature in VY Scl systems. This is further supported by the fact that the X-ray hardness ratio increases with the shallowness of the UV slope in a small CV sample we examine. Furthermore, for 105 disk-dominated systems, the International Ultraviolet Explorer spectra UV slope decreases in the same order as the ratio of the X-ray flux to optical/UV flux: from SU UMa’s, to U Gem’s, Z Cam’s, UX UMa’s, and VY Scl’s.
Dynamical Properties of Internal Shocks Revisited
Authors: Pe’er Asaf , Long Killian , Casella Piergiorgio
Published: August 2017

Internal shocks between propagating plasma shells, originally ejected at different times with different velocities, are believed to play a major role in dissipating the kinetic energy, thereby explaining the observed light curves and spectra in a large range of transient objects. Even if initially the colliding plasmas are cold, following the first collision, the plasma shells are substantially heated, implying that in a scenario of multiple collisions, most collisions take place between plasmas of non-zero temperatures. Here, we calculate the dynamical properties of plasmas resulting from a collision between arbitrarily hot plasma shells, moving at arbitrary speeds. We provide simple analytical expressions valid for both ultrarelativistic and Newtonian velocities for both hot and cold plasmas. We derive the minimum criteria required for the formation of the two-shock wave system, and show that in the relativistic limit, the minimum Lorentz factor is proportional to the square root of the ratio of the initial plasmas enthalpies. We provide basic scaling laws of synchrotron emission from both the forward and reverse-shock waves, and show how these can be used to deduce the properties of the colliding shells. Finally, we discuss the implications of these results in the study of several astronomical transients, such as X-ray binaries, radio-loud quasars, and gamma-ray bursts.
Insights on the Spectral Signatures of Stellar Activity and Planets from PCA
Authors: Davis Allen B. , Cisewski Jessi , Dumusque Xavier , Fischer Debra A. , Ford Eric B.
Published: August 2017

Photospheric velocities and stellar activity features such as spots and faculae produce measurable radial velocity signals that currently obscure the detection of sub-meter-per-second planetary signals. However, photospheric velocities are imprinted differently in a high-resolution spectrum than are Keplerian Doppler shifts. Photospheric activity produces subtle differences in the shapes of absorption lines due to differences in how temperature or pressure affects the atomic transitions. In contrast, Keplerian Doppler shifts affect every spectral line in the same way. With a high enough signal-to-noise (S/N) and resolution, statistical techniques can exploit differences in spectra to disentangle the photospheric velocities and detect lower-amplitude exoplanet signals. We use simulated disk-integrated time-series spectra and principal component analysis (PCA) to show that photospheric signals introduce spectral line variability that is distinct from that of Doppler shifts. We quantify the impact of instrumental resolution and S/N for this work.
An Optically Faint Quasar Survey at z ∼ 5 in the CFHTLS Wide Field: Estimates of the Black Hole Masses and Eddington Ratios
Authors: Ikeda H. , Nagao T. , Matsuoka K. , Kawakatu N. , Kajisawa M. , Akiyama M. , Miyaji T. , Morokuma T.
Published: August 2017

We present the result of our spectroscopic follow-up observation for faint quasar candidates at z ∼ 5 in part of the Canada–France–Hawaii Telescope Legacy Survey wide field. We select nine photometric candidates and identify three z ∼ 5 faint quasars, one z ∼ 4 faint quasar, and a late-type star. Since two faint quasar spectra show the C iv emission line without suffering from a heavy atmospheric absorption, we estimate their black hole masses (

) and Eddington ratios (

). The inferred

are 9.04 ± 0.14 and 8.53 ± 0.20, respectively. In addition, the inferred

are −1.00 ± 0.15 and −0.42 ± 0.22, respectively. If we adopt that

, the seed black hole masses (

) of our z ∼ 5 faint quasars are expected to be

in most cases. We also compare the observational results with a mass accretion model, where angular momentum is lost due to supernova explosions. Accordingly,

of the z ∼ 5 faint quasars in our sample can be explained even if

is

. Since z ∼ 6 luminous qusars and our z ∼ 5 faint quasars are not on the same evolutionary track, z ∼ 6 luminous quasars and our z ∼ 5 quasars are not the same populations but different populations, due to the difference of a period of the mass supply from host galaxies. Furthermore, we confirm that one can explain

of z ∼ 6 luminous quasars and our z ∼ 5 faint quasars even if their seed black holes are formed at z ∼ 7.
High-energy Gamma Rays from the Milky Way: Three-dimensional Spatial Models for the Cosmic-Ray and Radiation Field Densities in the Interstellar Medium
Authors: Porter T. A. , Jóhannesson G. , Moskalenko I. V.
Published: August 2017

High-energy γ-rays of interstellar origin are produced by the interaction of cosmic-ray (CR) particles with the diffuse gas and radiation fields in the Galaxy. The main features of this emission are well understood and are reproduced by existing CR propagation models employing 2D galactocentric cylindrically symmetrical geometry. However, the high-quality data from instruments like the Fermi Large Area Telescope reveal significant deviations from the model predictions on few to tens of degrees scales, indicating the need to include the details of the Galactic spiral structure and thus requiring 3D spatial modeling. In this paper, the high-energy interstellar emissions from the Galaxy are calculated using the new release of the GALPROP code employing 3D spatial models for the CR source and interstellar radiation field (ISRF) densities. Three models for the spatial distribution of CR sources are used that are differentiated by their relative proportion of input luminosity attributed to the smooth disk or spiral arms. Two ISRF models are developed based on stellar and dust spatial density distributions taken from the literature that reproduce local near- to far-infrared observations. The interstellar emission models that include arms and bulges for the CR source and ISRF densities provide plausible physical interpretations for features found in the residual maps from high-energy γ-ray data analysis. The 3D models for CR and ISRF densities provide a more realistic basis that can be used for the interpretation of the nonthermal interstellar emissions from the Galaxy.
The Importance of Preventive Feedback: Inference from Observations of the Stellar Masses and Metallicities of Milky Way Dwarf Galaxies
Authors: Lu Yu , Benson Andrew , Wetzel Andrew , Mao Yao-Yuan , Tonnesen Stephanie , Peter Annika H. G. , Boylan-Kolchin Michael , Wechsler Risa H.
Published: August 2017

Dwarf galaxies are known to have remarkably low star formation efficiency due to strong feedback. Adopting the dwarf galaxies of the Milky Way (MW) as a laboratory, we explore a flexible semi-analytic galaxy formation model to understand how the feedback processes shape the satellite galaxies of the MW. Using Markov Chain Monte Carlo, we exhaustively search a large parameter space of the model and rigorously show that the general wisdom of strong outflows as the primary feedback mechanism cannot simultaneously explain the stellar mass function and the mass–metallicity relation of the MW satellites. An extended model that assumes that a fraction of baryons is prevented from collapsing into low-mass halos in the first place can be accurately constrained to simultaneously reproduce those observations. The inference suggests that two different physical mechanisms are needed to explain the two different data sets. In particular, moderate outflows with weak halo mass dependence are needed to explain the mass–metallicity relation, and prevention of baryons falling into shallow gravitational potentials of low-mass halos (e.g., “pre-heating”) is needed to explain the low stellar mass fraction for a given subhalo mass.
Where and When: Optimal Scheduling of the Electromagnetic Follow-up of Gravitational-wave Events Based on Counterpart Light-curve Models
Authors: Salafia Om Sharan , Colpi Monica , Branchesi Marica , Chassande-Mottin Eric , Ghirlanda Giancarlo , Ghisellini Gabriele , D. Vergani Susanna
Published: August 2017

The electromagnetic (EM) follow-up of a gravitational-wave (GW) event requires scanning a wide sky region, defined by the so-called “skymap,” to detect and identify a transient counterpart. We propose a novel method that exploits the information encoded in the GW signal to construct a “detectability map,” which represents the time-dependent (“when”) probability of detecting the transient at each position of the skymap (“where”). Focusing on the case of a neutron star binary inspiral, we model the associated short gamma-ray burst afterglow and macronova emission using the probability distributions of binary parameters (sky position, distance, orbit inclination, mass ratio) extracted from the GW signal as inputs. The resulting family of possible light curves is the basis for constructing the detectability map. As a practical example, we apply the method to a simulated GW signal produced by a neutron star merger at 75 Mpc whose localization uncertainty is very large (∼1500 deg2). We construct observing strategies for optical, infrared, and radio facilities based on the detectability maps, taking VST, VISTA, and MeerKAT as prototypes. Assuming limiting fluxes of

,

(AB magnitudes), and

(

) for ∼1000 s of exposure each, the afterglow and macronova emissions are successfully detected with a minimum observing time of 7, 15, and 5 hr respectively.
X-Ray Morphological Analysis of the Planck ESZ Clusters
Authors: Lovisari Lorenzo , Forman William R. , Jones Christine , Ettori Stefano , Andrade-Santos Felipe , Arnaud Monique , Démoclès Jessica , Pratt Gabriel W. , Randall Scott , Kraft Ralph
Published: August 2017

X-ray observations show that galaxy clusters have a very large range of morphologies. The most disturbed systems, which are good to study how clusters form and grow and to test physical models, may potentially complicate cosmological studies because the cluster mass determination becomes more challenging. Thus, we need to understand the cluster properties of our samples to reduce possible biases. This is complicated by the fact that different experiments may detect different cluster populations. For example, Sunyaev–Zeldovich (SZ) selected cluster samples have been found to include a greater fraction of disturbed systems than X-ray selected samples. In this paper we determine eight morphological parameters for the Planck Early Sunyaev–Zeldovich (ESZ) objects observed with XMM-Newton. We found that two parameters, concentration and centroid shift, are the best to distinguish between relaxed and disturbed systems. For each parameter we provide the values that allow selecting the most relaxed or most disturbed objects from a sample. We found that there is no mass dependence on the cluster dynamical state. By comparing our results with what was obtained with REXCESS clusters, we also confirm that the ESZ clusters indeed tend to be more disturbed, as found by previous studies.
On Estimation of Contamination from Hydrogen Cyanide in Carbon Monoxide Line-intensity Mapping
Authors: Chung Dongwoo T. , Li Tony Y. , Viero Marco P. , Church Sarah E. , Wechsler Risa H.
Published: August 2017

Line-intensity mapping surveys probe large-scale structure through spatial variations in molecular line emission from a population of unresolved cosmological sources. Future such surveys of carbon monoxide line emission, specifically the CO(1-0) line, face potential contamination from a disjointed population of sources emitting in a hydrogen cyanide emission line, HCN(1-0). This paper explores the potential range of the strength of HCN emission and its effect on the CO auto power spectrum, using simulations with an empirical model of the CO/HCN–halo connection. We find that effects on the observed CO power spectrum depend on modeling assumptions but are very small for our fiducial model, which is based on current understanding of the galaxy–halo connection. Given the fiducial model, we expect the bias in overall CO detection significance due to HCN to be less than 1%.
Contester dans l’espace éducatif : l’expérience de l’occupation des lycées par le mouvement étudiant chilien
Authors: Montoni Angelo
Published: August 2017

Comment l’espace éducatif est-il devenu le lieu où se produisent la plupart des expériences politiques des jeunes Chiliens ? Une enquête réalisée de 2011 à 2012 à Santiago du Chili, lors de la mobilisation sociale la plus importante de l’histoire récente du pays, observe de nouvelles formes de contestation utilisées par les lycéens et les étudiants chiliens. Sur la base d’une série de récits biographiques et d’observations, cette étude se centre sur les pratiques politiques radicales mises en place lors des occupations de lycées par les jeunes. Parmi les plus visibles se trouvent l’organisation de collectifs, l’autogestion éducative, la démocratie directe et l’action directe violente. Cette enquête fait le constat que les jeunes engagés dans l’occupation de lycées transforment leur espace principal de sociabilité, au moins pour une période, en espace émancipateur et de subversion de l’ordre dominant.
A preliminary study to investigate the prevalence of pain in elite dressage riders during competition in the United Kingdom
Authors: Lewis V. , Kennerley R.
Published: August 2017

Equestrianism is more dangerous than many sports including motorcycle riding, skiing, football, and rugby with one in five equestrians seriously injured during their riding career. Current research has focused on acute riding injuries but as seen in other sports over-use injuries, repetitive strain and lifestyle could aggravate symptoms causing chronic pain. An elite rider suffering from pain may still choose to compete with pain due to the pressures from sponsors and owners and the need for competition success. The aim of the study was to investigate the prevalence of riders at the elite level competing with pain, and whether they perceived this pain to have a negative effect on their performance. A quantitative approach was used due to the experimental nature of the study. Fifty questionnaires were distributed to elite dressage riders (British Dressage Group 3 and above) at the Festival of Dressage, Hartpury College to establish the prevalence of riders competing with pain. 74% of elite dressage riders competed while experiencing pain, 62% of this pain was classed as chronic and 76% of riders stated that this pain was in the low back. Over half (51%) relieved the symptoms of pain by using over the counter pain medication. There was a highly significant relationship between riders competing with pain and the perception that this pain affecting negatively on performance (χ2=16.216a, df=1, P=0.001). This high incidence of elite dressage riders who compete with pain, particularly lower back pain (LBP), could be problematic given the longevity of a rider’s career which can span over four decades. This research reports rider’s perceptions and self-reported pain and management options, which may affect the data. Further research is needed to establish the causes of back pain and appropriate management strategies.
Correlation and variability between weighing, counting and analytical methods to determine ergot (Claviceps purpurea) contamination of grain
Authors: Grusie T. , Cowan V. , Singh J. , McKinnon J. , Blakley B.
Published: August 2017

Ergot alkaloid mycotoxins produced by the fungusClaviceps purpurea, are contaminants of cereal crops and grasses. The objectives of this study were to determine the correlation between number of ergot sclerotia and weight compared to the total ergot alkaloid concentration, to evaluate the effect of grinding process (i.e. particle size (PS)) on ergot alkaloid analysis using high performance liquid chromatography – tandem mass spectrometry, and to determine the impact of sample volume on analytical variability. This study demonstrated that correlations exist between both ergot sclerotia count (R2=0.7242,P<0.001) and ergot sclerotia weight (R2=0.9618,P<0.001) compared to the total alkaloid concentration of 6 ergot alkaloids. However, at alkaloid ergot concentrations below 350 µg/kg grain, ergot sclerotia count (R2=0.0002,P=0.956) and ergot sclerotia weight (R2=0.0064,P=0.769) were not correlated to the total alkaloid concentration. A lower variability (P=0.041), defined by coefficient of variation (CV), was observed using a commercial UDY cyclone sample mill (PS=192 µm, CV=9 µg/kg) as compared to a household coffee grinder (PS=516 µm, CV=66 µg/kg). Total amount and concentration of individual ergot alkaloids varied (P<0.05) among sclerotia of similar weight. For the analytical method, CV was numerically reduced as sample volume increased (97% CV for 75 ml to 64% CV for 1000 ml; mean of all concentrations) but increased as sample concentration declined (17% CV for 81,678 µg/kg to 284% for 35 µg/kg; mean of all sample volumes). This implies that analysis of small sample volumes at low ergot alkaloid concentrations may result in highly variable and potentially misleading results. In conclusion, number of ergot sclerotia and weight are unreliable indicators of alkaloid content at ergot concentrations below 350 µg/kg and particle size influences the variability. An analytical approach with fine grinding (mean PS<200 µm, 85% particles <400 µm) of a large sample should be used to assess low-level ergot contamination.
Digital Entrepreneurial Charity, Solidarity, and Social Change
Authors: Saiz-Alvarez José Manuel , Colvin-Díez Jorge , Cuñado Jorge Hernando
Published: August 2017

Microcredit has been studied from many perspectives. In this work, the authors analyze KIVA, the most important Person-to-Person microfinance organization from the viewpoint of social change, and they consider how it has impacted on the nascent of a new wave of entrepreneurs known as digital entrepreneurial charity. Applied to KIVA, the authors analyze the impact of the digital space and its Internet-based Peer-to-Peer Lending to create social change in the poor, while alleviating the poverty thanks to solidarity and charity. This work concludes affirming that banking the poor and education, with the intensive use of Internet-based devices, is the best way to alleviate poverty in the digital and globalized economic world. Finally, after their last research, the authors found some critics about Kiva and microcredits which might be interesting to be considered and these have been analyzed at the end of this work.
An Intuitionistic Fuzzy Multi-Criteria Decision-Making Method Based on an Exponential-Related Function
Authors: Aikhuele Daniel , Turan Faiz
Published: August 2017

Intuitionistic fuzzy multiple criteria decision making (MCDM) method which is based on an exponential-related function, adopted in the Technique for order preference by similarity to ideal solution (TOPSIS) has been proposed in this study. The exponential-related function which is used for comparing intuitionistic-fuzzy-sets (IFS), and as a replacement for the traditional exponential score function which is only effective for determining priority weights that involve pairwise-comparison, has been applied, for computing the separation measure from the fuzzy positive and negative ideal solution to determine the relative closeness-coefficients of alternatives. The main advantage of this method includes (1) its ability to account for Decision-makers (DMs) attitudinal-character in the decision-making process as-well-as to represent the aggregated effect of the positive/negative evaluations in the performance ratings of the alternatives based on the IFS-data and (2) The simplicity of the method both in its concept and computational procedures. To demonstrate the feasibility of the method, it has been applied for the evaluation of some hypothetical design-related problems and for a real-life case study.
Fuzzy Logic Based Clustering Algorithm for Wireless Sensor Networks
Authors: El Alami Hassan , Najid Abdellah
Published: August 2017

WSNs have many applications in modern life. Thus, optimization of the network operation is required to maximize its lifetime. The energy is a major issue in order to increase the lifetime of WSNs. The clustering algorithm is one of the proposed algorithms to enhance the lifetime of WSNs. The operation of the clustering algorithm is divided into cluster heads (CHs) selection and cluster formation. However, most of the previous works have focused on CHs selection, and have not considered the cluster formation process, which is the important issue in clustering algorithm based routing schemes, and it can drastically affect the lifetime of WSNs. In this paper, a Fuzzy Logic based Clustering Algorithm for WSN (CAFL) has been proposed to improve the lifetime of WSNs. This approach uses fuzzy logic for CHs selection and clusters formation processes by using residual energy and closeness to the sink as fuzzy inputs in terms of CH selection, and residual energy of CH and closeness to CHs as fuzzy inputs in terms of clusters formation. Simulation results justify its efficiency.
An Efficient Time Series Forecasting Method Exploiting Fuzziness and Turbulences in Data
Authors: Pandey Prateek , Kumar Shishir , Shrivastava Sandeep
Published: August 2017

In recent years, there has been a growing interest in Time Series forecasting. A number of time series forecasting methods have been proposed by various researchers. However, a common trend found in these methods is that they all underperform on a data set that exhibit uneven ups and downs (turbulences). In this paper, a new method based on fuzzy time-series (henceforth FTS) to forecast on the fundament of turbulences in the data set is proposed. The results show that the turbulence based fuzzy time series forecasting is effective, especially, when the available data indicate a high degree of instability. A few benchmark FTS methods are identified from the literature, their limitations and gaps are discussed and it is observed that the proposed method successfully overcome their deficiencies to produce better results. In order to validate the proposed model, a performance comparison with various conventional time series models is also presented.
On Exploring Research Methods for Business Information Security Alignment and Artefact Engineering
Authors: Bobbert Yuri
Published: August 2017

This paper examines research methods for designing and engineering a Business Information Security (BIS) artefact. Preventing and responding to cybercrime is becoming an integral part of management practices which are supervised by the Board of Directors (BoD), and it can no longer be perceived as just traditional IT. In order to improve the maturity of business information security a transformation is needed and this requires adequate reporting and dashboarding. Dashboard functions such as the current versus the desired state of the Maturity of Business Information Security (MBIS) reflect certain parameters that boards can influence. Determining the key dashboard functions that reflect these parameters of control was the main motivation for this research paper and the ultimate goal was to engineer a BIS artefact. We propose a research and design method that could be used to establish an experimental dashboard with initial parameters of control based on a Group Support System (GSS) approach. Finally, GSS is evaluated as a method for a) examining which parameters are effective for BIS, from multiple perspectives and b) helping to implement the artefact (make it fit the purpose) as well as the associated business alignment and decision-making.
How IT Governance Practices Contribute to Inter-Municipal ICT Cooperation and Its Benefits
Authors: Dahlberg Tomi , Helin Ari
Published: August 2017

ICT is significant for municipal' services. Yet, they are usually operated with limited resources, which motivates cooperation. We investigated, how ICT cooperation was governed in 20 Finnish regions. As the theoretical basis, we reviewed TCE, RBV, IT governance practice and Granovetter's social network theories. The theory basis was used to identify theory-proposed cooperation benefits and to link these benefits to IT governance practices. We then compared theory-proposed benefits and practices to those detected in the 20 regions. Our findings revealed differences in ICT cooperation, in the gaining of benefits, and in the use of IT governance practices. The lack of social ties helped to understand differences. Our findings indicate that the emperor will not enjoy new clothes – ICT cooperation benefits – unless ICT cooperation is systematically organized for governance. We contribute to research by augmenting the theory base of IT governance research, by extending IT governance research to inter-organizational contexts and by showing how this theory base can be used empirically.
Simulation and Validation of Forming, Milling, Welding and Heat Treatment of an Alloy 718 Component
Authors: Steffenburg-Nordenström Joachim , Svensson Lars-Erik
Published: August 2017

This paper describes finite element simulations of a manufacturing process chain consisting of forming, weld preparation by milling, laser welding and stress relief heat treatment of an alloy 718 aero-engine part. The work also includes experimental validation with optical measurements of the part after each process step. Approximation and discretization errors were avoided by keeping the same mesh and constitutive model. The results show that the remaining stresses affect the subsequent manufacturing process step and therefore, simulation of the process chain is essential. The accuracy with respect to the geometry showed relatively good agreement between measurement and simulation.
Effect of Process Parameters on MRR and Surface Roughness in ECM of EN 31 Tool Steel Using WPCA
Authors: Das Milan Kumar , Barman Tapan Kumar , Kumar Kaushik , Sahoo Prasanta
Published: August 2017

Weighted principal component analysis is used to predict the optimal machining parameters for EN 31 tool steel in electrochemical machining for minimum surface roughness and maximum material removal rate based on L27 Taguchi orthogonal design. For this, multi-response performance index is calculated to derive an equivalent single objective function and then Taguchi method is used to optimize the process parameters. The separable influence of individual machining parameters and the interaction between these parameters are also investigated by using analysis of variance (ANOVA). Results show that the main significant factor on MRR and surface roughness is electrolyte concentration. The effects of process parameters viz. electrolyte concentration, voltage, feed rate and inter-electrode gap on MRR and surface roughness are also investigated using 3D surface and contour plots. Finally, the surface morphology is studied with the help of scanning electron microscopy (SEM) images.
A New Multi-Objective Green Location Routing Problem with Heterogonous Fleet of Vehicles and Fuel Constraint
Authors: Rabbani Masoud , Davoudkhani Mohsen , Farrokhi-Asl Hamed
Published: August 2017

This paper introduces a new variant of Multi-Objective Green Location Routing Problem (MOGLRP) in which the start and end location of each route can be distinct. In this paper, the authors present a new mathematical formulation for the MOGLRP with consideration of environmentally issues. MOGLRP states for the problem of finding routes for vehicles to serve a set of customers while minimizes the total traveled distance, minimizes the total cost including vehicle fixed cost and variable travel cost and the co2 emissions. In order to solve the proposed model, two solution methods are used. Firstly, an exact method which is able to solve small sized problems is applied. Since the exact methods are not able to solve NP-hard problems in a reasonable time, the second method which is called multi-objective evolutionary algorithms (MOEA) are taken into account to deal with large instances. Furthermore, four well-known multi-objective evolutionary algorithms, including non-dominated sorting genetic algorithm (NSGA-II) and multi-objective particle swarm optimization (MOPSO), Strength Pareto Evolutionary Algorithm II (SPEA- II) and Pareto Envelope-based Selection Algorithm II (PESA-II) are used to compare obtained results. A comparison results show the proficiency of the proposed algorithm with respect to the four performance metrics, including quantity metric, diversification metric, spacing metrics and mean ideal distance. Finally, concluding remarks and future research directions are provided.
IL-1β and IL-23 Promote Extrathymic Commitment of CD27+CD122− γδ T Cells to γδT17 Cells
Authors: Muschaweckh Andreas , Petermann Franziska , Korn Thomas
Published: August 2017

γδT17 cells are a subset of γδ T cells committed to IL-17 production and are characterized by the expression of IL-23R and CCR6 and lack of CD27 expression. γδT17 cells are believed to arise within a narrow time window during prenatal thymic development. In agreement with this concept, we show in this study that adult Rag1−/− recipient mice of Il23rgfp/+ (IL-23R reporter) bone marrow selectively lack IL-23R+ γδT17 cells. Despite their absence in secondary lymphoid tissues during homeostasis, γδT17 cells emerge in bone marrow chimeric mice upon induction of skin inflammation by topical treatment with imiquimod cream (Aldara). We demonstrate that IL-1β and IL-23 together are able to promote the development of bona fide γδT17 cells from peripheral CD122−IL-23R− γδ T cells, whereas CD122+ γδ T cells fail to convert into γδT17 cells and remain stable IFN-γ producers (γδT1 cells). IL-23 is instrumental in expanding extrathymically generated γδT17 cells. In particular, TCR-Vγ4+ chain–expressing CD122−IL-23R− γδ T cells are induced to express IL-23R and IL-17 outside the thymus during skin inflammation. In contrast, TCR-Vγ1+ γδ T cells largely resist this process because prior TCR engagement in the thymus has initiated their commitment to the γδT1 lineage. In summary, our data reveal that the peripheral pool of γδ T cells retains a considerable degree of plasticity because it harbors “naive” precursors, which can be induced to produce IL-17 and replenish peripheral niches that are usually occupied by thymus-derived γδT17 cells.
Chemokine Receptor–Dependent Control of Skin Tissue–Resident Memory T Cell Formation
Authors: Zaid Ali , Hor Jyh Liang , Christo Susan N. , Groom Joanna R. , Heath William R. , Mackay Laura K. , Mueller Scott N.
Published: August 2017

Infection or inflammation of the skin recruits effector CD8+ T cells that enter the epidermis and form populations of long-lived tissue-resident memory T (TRM) cells. These skin TRM cells migrate within the constrained epidermal environment by extending multiple dynamic dendritic projections and squeezing between keratinocytes to survey the tissue for pathogens. In this study, we examined the signals required for this distinctive mode of T cell migration by inhibiting key cytoskeletal components and performing intravital two-photon microscopy to visualize TRM cell behavior. We found that TRM cell motility and dendrite formation required an intact actomyosin cytoskeleton and the Rho-associated coiled-coil containing kinases. We also identified an essential role for microtubules for maintaining skin TRM cell shape and cellular integrity. We reveal a role for pertussis toxin–sensitive signaling for TRM cell dendritic morphology and migration that is independent of CXCR3 or CXCR6, or the skin-selective chemokine receptors CCR10 and CCR8. However, we found that CXCR6 and CCR10 expression by CD8+ T cells was required for the optimal formation of memory T cell populations, in particular TRM cell populations in the skin.
Vascular anomalies in the mesenteric circulation of patients with Crohn’s disease: a pilot study
Authors: Zamboni Matilde , Sibilla Maria Grazia , Galeotti Roberto , Pedriali Massimo , Ascanelli Simona
Published: August 2017

Crohn’s disease (CD) is a chronic inflammatory bowel disease and its pathogenesis is still not well understood. Previous studies suggested the possibility of the involvement of vascular system, but, todate, the mesenteric circulation has poor been investigated, especially in complicated CD cases requiring colectomy. We investigated the mesenteric circulation in a case-control pilot study, including 19 controls and 7 patients affected by complicated cases of CD. Cases and controls underwent selective angiography of both superior and inferior mesenteric district. Transit time was found either significantly shortened in 2/7 cases (29%), or prolonged 5/7 (71%) (P=0.0034 in the superior mesenteric district; P=0.0079 in the inferior mesenteric district), respectively due to the presence of A-V malformations and of a miscellaneous of venous abnormalities, which included thrombosis, hypoplasia and extra-truncular venous malformations. Our study demonstrates the presence of congenital or acquired vascular anomalies in a small sample of CD patients not responder to current treatment and with severe complications. The present pilot study warrants further investigations.
Consumer ethnocentrism in developing countries: Application of a model in Zimbabwe
Authors: Makanyeza Charles , Du Toit Francois
Published: August 2017

Orientation: The study focused on the application of a model of consumer ethnocentrism in Zimbabwe, a developing country.Research purpose: The study sought to determine the effect of consumer ethnocentrism on consumer attitude, to determine the effect of consumer attitude on purchase intention and to establish the moderating effects of gender, age, education, income, ethnic grouping and city of residence on the effect of consumer ethnocentrism on consumer attitude.Motivation for the study: Research on consumer ethnocentrism in developing countries is still in its infancy. There is a need to conduct more research on consumer ethnocentrism in developing countries in order to enhance an understanding of this important construct in international marketing.Research design, approach and method: The study uses a cross section of 289 consumers from Harare and Bulawayo, the two largest cities in Zimbabwe. Structural equation modeling and moderated regression analysis were conducted to test the research hypotheses.Main findings: The study found that consumer ethnocentrism has a negative effect on consumer attitude, and consumer attitude has a positive effect on purchase intention. None of the demographic variables was found to significantly moderate the effect of consumer ethnocentrism on consumer attitude.Practical and managerial implications: Marketers who intend to expand into developing markets such as Zimbabwe are advised to consider consumer ethnocentrism and attitudes towards foreign poultry products. Firms targeting foreign markets where consumers are ethnocentric, such as in Zimbabwe, are advised to set up manufacturing facilities in such countries instead of exporting.Contribution and value-add: The study enhances our understanding of consumer ethnocentrism in developing countries where research on consumer ethnocentrism is still in its infancy.