bluuebunny/crossref_metadata_2025 huggingface dataset:
Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis of Ethylene (C2H4) and D4-Ethylene (C2D4) Ices Exposed to Ionizing Radiation via Combined Infrared Spectroscopy and Reflectron Time-of-flight Mass Spectrometry
Authors: Abplanalp Matthew J. , Kaiser Ralf I.
Published: February 2017

The processing of the hydrocarbon ice, ethylene (C2H4/C2D4), via energetic electrons, thus simulating the processes in the track of galactic cosmic-ray particles, was carried out in an ultrahigh vacuum apparatus. The chemical evolution of the ices was monitored online and in situ utilizing Fourier transform infrared spectroscopy (FTIR) and during temperature programmed desorption, via a quadrupole mass spectrometer utilizing electron impact ionization (EI-QMS) and a reflectron time-of-flight mass spectrometer utilizing a photoionization source (PI-ReTOF-MS). Several previous in situ studies of ethylene ice irradiation using FTIR were substantiated with the detection of six products: [CH4 (CD4)], acetylene [C2H2 (C2D2)], the ethyl radical [C2H5 (C2D5)], ethane [C2H6 (C2D6)], 1-butene [C4H8 (C4D8)], and n-butane [C4H10 (C4D10)]. Contrary to previous gas phase studies, the PI-ReTOF-MS detected several groups of hydrocarbon with varying degrees of saturation: C
n
H2n+2 (n = 4–10), C
n
H2n
(n = 2–12, 14, 16), C
n
H2n−2 (n = 3–12, 14, 16), C
n
H2n−4 (n = 4–12, 14, 16), C
n
H2n−6 (n = 4–10, 12), C
n
H2n−8 (n = 6–10), and C
n
H2n−10 (n = 6–10). Multiple laboratory studies have shown the facile production of ethylene from methane, which is a known ice constituent in the interstellar medium. Various astrophysically interesting molecules can be associated with the groups detected here, such as allene/methylacetylene (C3H4) or 1, 3-butadiene (C4H6) and its isomers, which have been shown to lead to polycyclic aromatic hydrocarbons. Finally, several hydrocarbon groups detected here are unique to ethylene ice versus ethane ice and may provide understanding of how complex hydrocarbons form in astrophysical environments.
Photoionization Models for the Inner Gaseous Disks of Herbig Be Stars: Evidence against Magnetospheric Accretion?*
Authors: Patel P. , Sigut T. A. A. , Landstreet J. D.
Published: February 2017

We investigate the physical properties of the inner gaseous disks of three hot Herbig B2e stars, HD 76534, HD 114981, and HD 216629, by modeling CFHT-ESPaDOns spectra using non-LTE radiative transfer codes. We assume that the emission lines are produced in a circumstellar disk heated solely by photospheric radiation from the central star in order to test whether the optical and near-infrared emission lines can be reproduced without invoking magnetospheric accretion. The inner gaseous disk density was assumed to follow a simple power-law in the equatorial plane, and we searched for models that could reproduce observed lines of H i (Hα and Hβ), He i, Ca ii, and Fe ii. For the three stars, good matches were found for all emission line profiles individually; however, no density model based on a single power-law was able to reproduce all of the observed emission lines. Among the single power-law models, the one with the gas density varying as ∼10−10(R
*/R)3 g cm−3 in the equatorial plane of a 25 R
* (0.78 au) disk did the best overall job of representing the optical emission lines of the three stars. This model implies a mass for the Hα-emitting portion of the inner gaseous disk of ∼10−9
M
*. We conclude that the optical emission line spectra of these HBe stars can be qualitatively reproduced by a ≈1 au, geometrically thin, circumstellar disk of negligible mass compared to the central star in Keplerian rotation and radiative equilibrium.
Logamediate Inflation in f(T) Teleparallel Gravity
Authors: Rezazadeh Kazem , Abdolmaleki Asrin , Karami Kayoomars
Published: February 2017

We study logamediate inflation in the context of f(T) teleparallel gravity. f(T)-gravity is a generalization of the teleparallel gravity which is formulated on the Weitzenbock spacetime, characterized by the vanishing curvature tensor (absolute parallelism) and the non-vanishing torsion tensor. We consider an f(T)-gravity model which is sourced by a canonical scalar field. Assuming a power-law f(T) function in the action, we investigate an inflationary universe with a logamediate scale factor. Our results show that, although logamediate inflation is completely ruled out by observational data in the standard inflationary scenario based on Einstein gravity, it can be compatible with the 68% confidence limit joint region of Planck 2015 TT,TE,EE+lowP data in the framework of f(T)-gravity.
Magnetohydrodynamic Simulations of the Formation of Molecular Clouds toward the Stellar Cluster Westerlund 2: Interaction of a Jet with a Clumpy Interstellar Medium
Authors: Asahina Yuta , Kawashima Tomohisa , Furukawa Naoko , Enokiya Rei , Yamamoto Hiroaki , Fukui Yasuo , Matsumoto Ryoji
Published: February 2017

The formation mechanism of CO clouds observed with the NANTEN2 and Mopra telescopes toward the stellar cluster Westerlund 2 is studied by 3D magnetohydrodynamic simulations, taking into account the interstellar cooling. These molecular clouds show a peculiar shape composed of an arc-shaped cloud on one side of the TeV γ-ray source HESS J1023-575 and a linear distribution of clouds (jet clouds) on the other side. We propose that these clouds are formed by the interaction of a jet with clumps of interstellar neutral hydrogen (H i). By studying the dependence of the shape of dense cold clouds formed by shock compression and cooling on the filling factor of H i clumps, we found that the density distribution of H i clumps determines the shape of molecular clouds formed by the jet–cloud interaction: arc clouds are formed when the filling factor is large. On the other hand, when the filling factor is small, molecular clouds align with the jet. The jet propagates faster in models with small filling factors.
A Small Fullerene (C24) may be the Carrier of the 11.2 μm Unidentified Infrared Band
Authors: Bernstein L. S. , Shroll R. M. , Lynch D. K. , Clark F. O.
Published: February 2017

We analyze the spectrum of the 11.2 μm unidentified infrared band (UIR) from NGC 7027 and identify a small fullerene (C24) as a plausible carrier. The blurring effects of lifetime and vibrational anharmonicity broadening obscure the narrower, intrinsic spectral profiles of the UIR band carriers. We use a spectral deconvolution algorithm to remove the blurring, in order to retrieve the intrinsic profile of the UIR band. The shape of the intrinsic profile—a sharp blue peak and an extended red tail—suggests that the UIR band originates from a molecular vibration–rotation band with a blue band head. The fractional area of the band-head feature indicates a spheroidal molecule, implying a nonpolar molecule and precluding rotational emission. Its rotational temperature should be well approximated by that measured for nonpolar molecular hydrogen, ∼825 K for NGC 7027. Using this temperature, and the inferred spherical symmetry, we perform a spectral fit to the intrinsic profile, which results in a rotational constant implying C24 as the carrier. We show that the spectroscopic parameters derived for NGC 7027 are consistent with the 11.2 μm UIR bands observed for other objects. We present density functional theory (DFT) calculations for the frequencies and infrared intensities of C24. The DFT results are used to predict a spectral energy distribution (SED) originating from absorption of a 5 eV photon, and characterized by an effective vibrational temperature of 930 K. The C24 SED is consistent with the entire UIR spectrum and is the dominant contributor to the 11.2 and 12.7 μm bands.
Advanced LIGO Constraints on Neutron Star Mergers and r-process Sites
Authors: Côté Benoit , Belczynski Krzysztof , Fryer Chris L. , Ritter Christian , Paul Adam , Wehmeyer Benjamin , O’Shea Brian W.
Published: February 2017

The role of compact binary mergers as the main production site of r-process elements is investigated by combining stellar abundances of Eu observed in the Milky Way, galactic chemical evolution (GCE) simulations, and binary population synthesis models, and gravitational wave measurements from Advanced LIGO. We compiled and reviewed seven recent GCE studies to extract the frequency of neutron star–neutron star (NS–NS) mergers that is needed in order to reproduce the observed [Eu/Fe] versus [Fe/H] relationship. We used our simple chemical evolution code to explore the impact of different analytical delay-time distribution functions for NS–NS mergers. We then combined our metallicity-dependent population synthesis models with our chemical evolution code to bring their predictions, for both NS–NS mergers and black hole–neutron star mergers, into a GCE context. Finally, we convolved our results with the cosmic star formation history to provide a direct comparison with current and upcoming Advanced LIGO measurements. When assuming that NS–NS mergers are the exclusive r-process sites, and that the ejected r-process mass per merger event is 0.01 M

, the number of NS–NS mergers needed in GCE studies is about 10 times larger than what is predicted by standard population synthesis models. These two distinct fields can only be consistent with each other when assuming optimistic rates, massive NS–NS merger ejecta, and low Fe yields for massive stars. For now, population synthesis models and GCE simulations are in agreement with the current upper limit (O1) established by Advanced LIGO during their first run of observations. Upcoming measurements will provide an important constraint on the actual local NS–NS merger rate, will provide valuable insights on the plausibility of the GCE requirement, and will help to define whether or not compact binary mergers can be the dominant source of r-process elements in the universe.
Lensing Constraints on the Mass Profile Shape and the Splashback Radius of Galaxy Clusters∗
Authors: Umetsu Keiichi , Diemer Benedikt
Published: February 2017

The lensing signal around galaxy clusters can, in principle, be used to test detailed predictions for their average mass profile from numerical simulations. However, the intrinsic shape of the profiles can be smeared out when a sample that spans a wide range of cluster masses is averaged in physical length units. This effect especially conceals rapid changes in gradient such as the steep drop associated with the splashback radius, a sharp edge corresponding to the outermost caustic in accreting halos. We optimize the extraction of such local features by scaling individual halo profiles to a number of spherical overdensity radii, and apply this method to 16 X-ray-selected, high-mass clusters targeted in the Cluster Lensing And Supernova survey with Hubble. By forward-modeling the weak- and strong-lensing data presented by Umetsu et al., we show that, regardless of the scaling overdensity, the projected ensemble density profile is remarkably well described by a Navarro–Frenk–White (NFW) or Einasto profile out to

R
∼
2.5

h

−
1

Mpc

, beyond which the profiles flatten. We constrain the NFW concentration to

c

200
c

=
3.66
±
0.11

at

M

200
c

≃
1.0
×

10

15

h

−
1

M

⊙

, consistent with and improved from previous work that used conventionally stacked lensing profiles, and in excellent agreement with theoretical expectations. Assuming the profile form of Diemer & Kravtsov and generic priors calibrated from numerical simulations, we place a lower limit on the splashback radius of the cluster halos, if it exists, of

R

sp

3
D

/

r

200
m

>
0.89

(

R

sp

3
D

>
1.83

h

−
1

Mpc

) at 68% confidence. The corresponding density feature is most pronounced when the cluster profiles are scaled by

r

200
m

, and smeared out when scaled to higher overdensities.
Young Galaxy Candidates in the Hubble Frontier Fields. IV. MACS J1149.5+2223
Authors: Zheng Wei , Zitrin Adi , Infante Leopoldo , Laporte Nicolas , Huang Xingxing , Moustakas John , Ford Holland C. , Shu Xinwen , Wang Junxian , Diego Jose M. , Bauer Franz E. , Iribarren Paulina Troncoso , Broadhurst Tom , Molino Alberto
Published: February 2017

We search for high-redshift dropout galaxies behind the Hubble Frontier Fields (HFF) galaxy cluster MACS J1149.5+2223, a powerful cosmic lens that has revealed a number of unique objects in its field. Using the deep images from the Hubble and Spitzer space telescopes, we find 11 galaxies at z > 7 in the MACS J1149.5+2223 cluster field, and 11 in its parallel field. The high-redshift nature of the bright z ≃ 9.6 galaxy MACS1149-JD, previously reported by Zheng et al., is further supported by non-detection in the extremely deep optical images from the HFF campaign. With the new photometry, the best photometric redshift solution for MACS1149-JD reduces slightly to z = 9.44 ± 0.12. The young galaxy has an estimated stellar mass of

(
7
±
2
)
×

10

8

M

⊙

, and was formed at

z
=

13.2

−
1.6

+
1.9

when the universe was ≈300 Myr old. Data available for the first four HFF clusters have already enabled us to find faint galaxies to an intrinsic magnitude of

M

UV

≃
−
15.5

, approximately a factor of 10 deeper than the parallel fields.
The Mysterious Dimmings of the T Tauri Star V1334 Tau
Authors: Rodriguez Joseph E. , Zhou George , Cargile Phillip A. , Stevens Daniel J. , Osborn Hugh P. , Shappee Benjamin J. , Reed Phillip A. , Lund Michael B. , Relles Howard M. , Latham David W. , Eastman Jason , Stassun Keivan G. , Bieryla Allyson , Esquerdo Gilbert A. , Berlind Perry , Calkins Michael L. , Vanderburg Andrew , Gaidos Eric , Ansdell Megan , Siverd Robert J. , Beatty Thomas G. , Kochanek Christopher S. , Pepper Joshua , Gaudi B. Scott , West Richard G. , Pollacco Don , James David , Kuhn Rudolf B. , Stanek Krzysztof Z. , Holoien Thomas W.-S. , Prieto Jose L. , Johnson Samson A. , Sergi Anthony , McCrady Nate , Johnson John A. , Wright Jason T. , Wittenmyer Robert A. , Horner Jonathan
Published: February 2017

We present the discovery of two extended ∼0.12 mag dimming events of the weak-lined T Tauri star V1334. The start of the first event was missed but came to an end in late 2003, and the second began in 2009 February, and continues as of 2016 November. Since the egress of the current event has not yet been observed, it suggests a period of >13 years if this event is periodic. Spectroscopic observations suggest the presence of a small inner disk, although the spectral energy distribution shows no infrared excess. We explore the possibility that the dimming events are caused by an orbiting body (e.g., a disk warp or dust trap), enhanced disk winds, hydrodynamical fluctuations of the inner disk, or a significant increase in the magnetic field flux at the surface of the star. We also find a ∼0.32 day periodic photometric signal that persists throughout the 2009 dimming which appears to not be due to ellipsoidal variations from a close stellar companion. High-precision photometric observations of V1334 Tau during K2 campaign 13, combined with simultaneous photometric and spectroscopic observations from the ground, will provide crucial information about the photometric variability and its origin.
Observational Signatures of Transverse Magnetohydrodynamic Waves and Associated Dynamic Instabilities in Coronal Flux Tubes
Authors: Antolin P. , Moortel I. De , Doorsselaere T. Van , Yokoyama T.
Published: February 2017

Magnetohydrodynamic (MHD) waves permeate the solar atmosphere and constitute potential coronal heating agents. Yet, the waves detected so far may be but a small subset of the true existing wave power. Detection is limited by instrumental constraints but also by wave processes that localize the wave power in undetectable spatial scales. In this study, we conduct 3D MHD simulations and forward modeling of standing transverse MHD waves in coronal loops with uniform and non-uniform temperature variation in the perpendicular cross-section. The observed signatures are largely dominated by the combination of the Kelvin–Helmholtz instability (KHI), resonant absorption, and phase mixing. In the presence of a cross-loop temperature gradient, we find that emission lines sensitive to the loop core catch different signatures compared to those that are more sensitive to the loop boundary and the surrounding corona, leading to an out-of-phase intensity and Doppler velocity modulation produced by KHI mixing. In all of the considered models, common signatures include an intensity and loop width modulation at half the kink period, a fine strand-like structure, a characteristic arrow-shaped structure in the Doppler maps, and overall line broadening in time but particularly at the loop edges. For our model, most of these features can be captured with a spatial resolution of 0.″33 and a spectral resolution of 25 km s−1, although we do obtain severe over-estimation of the line width. Resonant absorption leads to a significant decrease of the observed kinetic energy from Doppler motions over time, which is not recovered by a corresponding increase in the line width from phase mixing and KHI motions. We estimate this hidden wave energy to be a factor of 5–10 of the observed value.
8. L’échec dans la culture entrepreneuriale
Authors: Krauss Gerhard
Published: February 2017

Par la voie d’économistes, de gestionnaires, de sociologues et de philosophes, l’échec entrepreneurial nourrit actuellement le débat intellectuel en France et à l’étranger. Le présent article aborde ce thème dans une perspective sociologique, situant le phénomène par rapport au contexte social. Longtemps dissimulé aux yeux du public, l’échec entrepreneurial devient de plus en plus visible dans les sociétés européennes. On commence à lui reconnaître des vertus. Il réunit des situations très hétérogènes, tout en résultant toujours d’un ensemble de classifications sociales. Face à l’ampleur du phénomène, les politiques publiques sont appelées à s’emparer du sujet et à proposer des solutions telles que la sécurisation des parcours entrepreneuriaux. Quant aux dirigeants d’entreprises établies, leur implication à l’égard des jeunes entrepreneurs s’avère cruciale.
11. L’économie sociale et solidaire : le renouveau d’un idéal ?
Authors: Tovar Élisabeth
Published: February 2017

L’économie sociale et solidaire, au lieu de rechercher la maximisation du profit, se fonde sur l’humain, son épanouissement et son bien-être. Son histoire que l’on peut faire remonter au début xix e  siècle trouve son origine dans la rupture avec le capitalisme industriel sauvage. Elle a depuis acquis en importance, en diversité et en dynamisme toujours au service de l’humain, sous des formes variées. L’emploi au sein des entreprises de l’ESS est cependant plus faiblement rémunéré et plus précaire que les emplois des entreprises concurrentielles mais avec une plus forte satisfaction au travail. L’ESS est aujourd’hui traversée par un mouvement de normalisation marchande, parfois asphyxiée par ses compromis avec l’État et le marché. Enfin la conjonction des crises multiples qui frappent l’Europe conduit aujourd’hui l’économie vers un renouveau entrepreneurial solidaire et social.
L’immagine della coppia nella pittura tombale arcaica dell’Etruria
Authors: Amann Petra
Published: February 2017

L’elaborato repertorio figurativo della pittura tombale etrusca si presta bene a un’analisi delle diverse ideologie della coppia. Il tema del banchetto/convivio e le attività connesse, come la danza, offrivano la possibilità di rappresentare insieme i due sessi senza forzature. Dal punto di vista iconografico, nella Tarquinia del periodo tardo-arcaico questo tema si manifesta in una varietà di soluzioni figurative (banchetto/simposio a terra o su klinai, con o senza donne, con donna seduta o recumbente, con una o più coppie) – soluzioni che vengono interpretate non come scelte casuali, ma come portatrici di precisi messaggi ideologici nel complesso tessuto della società tarquiniese. Tramite i diversi tipi della rappresentazione conviviale il committente poteva porre l’enfasi o sulla sua appartenenza a un gruppo di persone di ugual rango, o sul suo (ben governato) oikos aristocratico, ma il motivo poteva anche divenire espressione di speranze salvifiche di carattere elitario. Un ruolo chiave rivestono le diverse interpretazioni dell’immagine della coppia uomo-donna.
Les couples étrusques au banquet : pratiques rituelles et alimentaires
Authors: Hugot Laurent
Published: February 2017

Dans cette contribution, nous nous proposons d’étudier les représentations de couples en Étrurie en nous attachant en particulier aux deux célèbres figurations peintes de la tombe des Boucliers de Tarquinia. À ce moment, après une longue éclipse entre la fin du vie s. av. J.-C. et le ive s. av. J.-C., les représentations des couples fondateurs des lignées familiales réapparaissent en contexte funéraire, mais de manière différente. Nous étudions spécialement les représentations de victuailles déposées sur les tables situées devant les couples de la tombe des Boucliers en les mettant en relation avec les données archéologiques à notre disposition.
Tanaquil et les chemises noires et brunes
Authors: Haack Marie-Laurence
Published: February 2017

L’article traite de la réception de la figure antique de Tanaquil, donc des femmes étrusques, à l’époque du fascisme et du nazisme auprès de non-spécialistes de l’étruscologie. Il montre que les analyses de la figure antique de Tanaquil par J.J. Bachofen ont connu dans l’Italie et dans l’Allemagne des années 30 un véritable regain d’intérêt encouragé par la publication simultanée, en 1926, de deux anthologies de ses œuvres. A. Rosenberg et J. Evola interprètent tous deux Tanaquil en un sens raciste  : pour A. Rosenberg, Tanaquil incarne la menace de la dépravation orientale et J. Evola montre les efforts qu’a dû déployer le monde romain pour éliminer cette composante préromaine, orientale et gynécocrate.
Les statues des bains de Zeuxippe à Constantinople : collection et patrimoine dans l’Antiquité tardive
Authors: Puech Vincent
Published: February 2017

Les bains de Zeuxippe furent édifiés à Constantinople à la fin du règne de Constantin, dans les années 330, au cœur du complexe formé par le palais impérial et l’hippodrome. Ils étaient décorés par soixante-dix statues de bronze représentant des personnages mythologiques, des auteurs d’œuvres de l’esprit et des hommes d’État. Cette collection fut détruite lors d’un incendie en 532, mais décrite en grec vers 500 par le poète Christodoros de Coptos. Elle exalte surtout la légende troyenne et la figure d’Apollon, conformément à la décoration générale pensée par Constantin pour la Nouvelle Rome orientale. Par la place donnée à Apollon et Poséidon surtout, mais aussi à Aphrodite et Artémis, elle s’inscrit dans la tradition des cultes de l’Acropole de l’ancienne Byzance. À cette époque, Constantin lui-même ne se sentait plus personnellement concerné par ces cultes. Pour autant, en collectionnant des statues enlevées pour certaines à des temples, il n’a pas réuni un patrimoine purement artistique. Le premier empereur chrétien a cherché à satisfaire les aspirations religieuses païennes de la majorité de la population, dans un monument étroitement associé à la fondation de Constantinople.
Le Cardinal Capella de Henry de Montherlant. Fragments d’un récit inachevé
Authors: Duroisin Pierre
Published: February 2017

Comme le manuscrit de Jules César qui fut présenté dans le n° 18 d’Anabases, celui du Cardinal Capella appartient au fonds Montherlant de la Bibliothèque nationale de France. Mais là s’arrête la ressemblance : Jules César est un dialogue datant de 1921 qui fut mené à son terme, alors que Le Cardinal Capella est un récit des années 1929-1930 et inachevé. Par ailleurs, le personnage de Jules César est partout dans l’œuvre de Montherlant, alors que Capella n’y est nulle part cité. Le sujet enfin est différent : la dimension politique qu’on avait dans le dialogue de 1921 est totalement absente du récit de 29-30. Capella est un prélat athée de la Renaissance italienne (il y a en cet Espagnol quelque chose des Borgia) dont le premier souci est la quête du plaisir, mais qui vit dans la peur, peur d’être démasqué, d’être trahi, d’être égorgé. L’expédition nocturne où l’a lancé son créateur fait un peu penser à celles que Suétone impute à Néron, ou à Caligula, mais le personnage est plus complexe qu’il n’y paraît, et s’il annonce par certains côtés le Costals des Jeunes Filles, le Guiscart de La Rose de sable ou le Don Juan de La Mort qui fait le trottoir, il est aussi parent, pour de plus hautes raisons, de l’abbé de Pradts de La Ville dont le prince est un enfant et des Garçons, voire du Celestino du Chaos et la nuit.
Observations d’un « profane » sur une réception singulière, celle de Weber « historien » de l’Antiquité
Authors: Chazel François
Published: February 2017

Après une période de purgatoire qui s’étend jusqu’aux années 60, les travaux de Weber relatifs à l’Antiquité ont acquis une réelle reconnaissance scientifique, en particulier sous l’influence d’A. Momigliano et de M. Finley. Cependant, cette réception n’a pas été exempte d’ambiguïtés et a abouti même à certaines formes de méconnaissance. La première ambiguïté tient à la rareté des commentaires de Finley sur l’apport propre de Weber. La seconde est liée à son interprétation biaisée sur quelques points majeurs  : Finley s’est plus intéressé à la typologie économique de la ville qu’aux idéaltypes contrastés de politique économique urbaine construits par Weber dans le cadre d’une comparaison entre ville médiévale et cité antique  ; la logique de l’idéaltype paraît lui avoir largement échappé. Enfin, l’œuvre de Weber a été si étroitement associée à l’approche de Finley qu’elle est devenue tributaire d’abord de son succès puis de son rejet plus ou moins radical. Comme l’a montré Christian Meier, Weber ne se laisse pas enfermer dans le vieux débat entre primitivisme et modernisme  ; sa méthode d’étude, centrée sur la mise en évidence de la spécificité du monde antique et le jeu des interdépendances entre les phénomènes qui la produit, conserve sa fécondité heuristique. C’est dans cet esprit qu’il convient d’approfondir la réception de Weber selon des voies multiples, brièvement évoquées en conclusion.
Hybrid Wrapper/Filter Gene Selection Using an Ensemble of Classifiers and PSO Algorithm
Authors: Boucheham Anouar , Batouche Mohamed
Published: February 2017

Bioinformatics has grown very quickly for the last 20 years, and it will grow even faster in the future. One of the long-standing open challenges in bioinformatics is biomarker identification and cancer diagnosis from gene expression. In this paper, the authors propose a novel hybrid wrapper/filter feature selection approach to identify the most informative genes for cancer diagnosis, named HWF-GS. It handles selection through two steps. The first one is an iterative filter-based mechanism to generate potential subsets of genes. The second step is the aggregation of the best-selected subsets by means of a wrapper-based consensus process that relies on a particle swarm optimization adapted to feature selection. An ensemble of classifiers (SVM and KNN) is employed to evaluate the selected genes. Experiments on nine publicly available cancer DNA microarray datasets have shown that HWF-GS selects robust signatures with high classification accuracy and competes with and even outperforms other methods in the literature.
Applicability of Cellular Automata in Cryptanalysis
Authors: Bhasin Harsh , Alam Naved
Published: February 2017

Cryptanalysis refers to finding the plaintext from the given cipher text. The problem reduces to finding the correct key from a set of possible keys, which is basically a search problem. Many researchers have put in a lot of effort to accomplish this task. Most of the efforts used conventional techniques. However, soft computing techniques like Genetic Algorithms are generally good in optimized search, though the applicability of such techniques to cryptanalysis is still a contentious point. This work carries out an extensive literature review of the cryptanalysis techniques, finds the gaps there in, in order to put the proposed technique in the perspective. The work also finds the applicability of Cellular Automata in cryptanalysis. A new technique has been proposed and verified for texts of around 1000 words. Each text is encrypted 10 times and then decrypted using the proposed technique. The work has also been compared with that employing Genetic Algorithm. The experiments carried out prove the veracity of the technique and paves way of Cellular automata in cryptanalysis. The paper also discusses the future scope of the work.
Privacy Aware Access Control
Authors: Bhatia Rekha , Gujral Manpreet Singh
Published: February 2017

Due to the ever increasing number of web services available through the Internet, the privacy as a fundamental human right is endangered. Informed consent and collection of information are two important aspects while interacting on the Internet through web services. The ease of data access and the ready availability of it through Internet, made it easier for interested parties to intrude into the individual's privacy in unprecedented ways. The regulatory and technical solutions adopted to curb this have achieved only a limited success. The main culprits in this regard are the incompatibilities in the regulatory measures and standards. This research work focuses on privacy preserving access control for sharing sensitive information in the arena of web services, provides some recent outlooks towards the critical need of privacy aware access control technologies and a comprehensive review of the existing work in this arena. Besides, a novel framework for privacy aware access to web services is also provided.
Fault-Recovery and Coherence in Internet of Things Choreographies
Authors: Cherrier Sylvain , Ghamri-Doudane Yacine M.
Published: February 2017

Facilitating the creation of applications for the Internet of Things (IoT) is a major concern to increase its development. D-LITe, our previous work, introduces genericity by providing a universal programming interface. Objects are dynamically configured to have their own behaviour, and their actions/reactions are considered as part of a whole application. D-LITeful Objects describe their capabilities, receives the application logic to be executed, and interacts with other. The application is seen as a choreography of behaviours. But the main issue of choreographies is the loss of coherence. Because of their unreliability, some networks used in IoT may introduce de-synchronization, leading to interactions errors. We propose to reintroduce coherence in order to keep the advantages of choreography while dealing with this main issue. An overlay of logical check-points defines the dependence between the coherent states of objects and triggers re-synchronizations. This paper ends with a discussion on the trade-off between the checking cost and the reliability improvement.
Stromal Cell Niches in the Inflamed Central Nervous System
Authors: Pikor Natalia B. , Cupovic Jovana , Onder Lucas , Gommerman Jennifer L. , Ludewig Burkhard
Published: February 2017

Inflammation in the CNS must be tightly regulated to respond efficiently to infection with neurotropic pathogens. Access of immune cells to the CNS and their positioning within the tissue are controlled by stromal cells that construct the barriers of the CNS. Although the role of the endothelium in regulating the passage of leukocytes and small molecules into the CNS has been studied extensively, the contribution of fibroblastic stromal cells as portals of entry into the CNS was only recently uncovered. We review the critical immune-stimulating role of meningeal fibroblasts in promoting recruitment and retention of lymphocytes during CNS inflammation. Activated meningeal fibroblastic stromal cells have the capacity to rapidly elaborate an immune-competent niche that sustains protective immune cells entering the CNS from the draining cervical lymph node. Such stromal cell niches can ultimately foster the establishment of tertiary lymphoid tissues during chronic neuroinflammatory conditions.
Reading Zimbabwe’s structural and political violence through the trope of the unnameable and unnamed in Brian Chikwava’s Harare North
Authors: Siziba Gugulethu
Published: February 2017

This article reads Zimbabwe’s structural and physical violence which extends to the country’s diaspora through Brian Chikwava’s novel Harare North (2009). The central argument the article makes is that the unnamed narrator is symbolic of the complex texture of Zimbabwe’s crisis whose most evident characteristics are predatory politics and state-sanctioned violence. The unnamed narrator stands as a core part of the shadowy figures of violence that are unleashed on those who are perceived as anti-state. On the contrary, he also represents the subjectification and precariousness that epitomises being Zimbabwean at this moment in the country’s history. The namelessness also evidences the slipperiness of the crisis and how it resists being made sense of and given form in simplistic ways. Notwithstanding the deformity assailing Zimbabweans as a mark of their country’s failure, the unnamed character also demonstrates the desire to survive under harsh, confused and confusing circumstances.
The effect of methylphenidate-OROS® on the narrative ability of children with attention-deficit hyperactivity disorder
Authors: Rausch Tessa L. , Kendall Diane L. , Kover Sara T. , Louw Elizabeth M. , Zsilavecz Ursula L. , Van der Merwe Anita
Published: February 2017

Background and objective: Children with attention-deficit hyperactivity disorder (ADHD) experience difficulty with expressive language, including form (e.g. grammatical construction) and content (e.g. coherence). The current study aimed to investigate the effect of methylphenidate-Osmotic Release Oral System® (MPH-OROS®) on the narrative ability of children with ADHD and language impairment, through the analysis of microstructure and macrostructure narrative elements.Method: In a single group off–on medication test design, narratives were obtained from 12 children with ADHD, aged 7–13 years, using wordless picture books. For microstructure, number of words, type–token ratio and mean length of utterance were derived from narrative samples using Systematic Analysis of Language Transcripts conventions. For macrostructure, the narratives were coded according to the Narrative Scoring Scheme, which includes seven narrative characteristics, as well as a composite score reflecting the child’s overall narrative ability.Results: The administration of MPH-OROS® resulted in a significant difference in certain aspects of language macrostructure: cohesion and overall narrative ability. Little effect was noted in microstructure elements.Conclusion: We observed a positive effect of stimulant medication on the macrostructure, but not on the microstructure, of narrative production. Although stimulant medication improves attention and concentration, it does not improve all aspects of language abilities in children with ADHD. Language difficulties associated with ADHD related to language content and use may be more responsive to stimulant medication than language form, which is likely to be affected by cascading effects of inattention, hyperactivity and impulsivity beginning very early in life and to progress over a more protracted period. Therefore, a combination of treatments is advocated to ensure that children with ADHD are successful in reaching their full potential.
Analysis of biological and meteorological controls of evapotranspiration in pristine forests and a pasture site in Amazonia
Authors: Junior Narciso Paulino , Von Randow Rita Cássia Silva , Von Randow Celso
Published: February 2017

This work studied the behavior and seasonality of evapotranspiration influenced by biotic and abiotic factors through analysis of diurnal variation of aerodynamic resistance (ra), stomatal resistance (rs) and decoupling factor (Ω). This index was proposed by Jarvis and McNaughton (1986) as an indicative of the control of these resistances on the evapotranspiration of vegetation. Selection of representative data from wet and dry seasons from a primary forest in Central Amazonia and a primary forest and a pasture sites in Southwestern Amazonia had shown that: (i) ra is about 20 s.m-1 in both forests in both seasons, and ranges from 70 to 100 s.m-1 in the pasture site; (ii) rs varies both throughout the day and seasonally, with medians increasing from 40 in the morning, to 150 s.m-1 in late afternoon, in the wet season in the forests and from 50 to 160 s.m-1 in the pasture. These values increase in the dry season, with the forests rs ranging from 50 up to 500 s.m-1 and pasture rs starting from 140 s.m‑1 and reaching up to more than 1800 s.m-1 in the dry afternoons; (iii) Ω ranges from 0.5 to 0.8 during the wet season, and reduces to values below 0.5 in the afternoons during the dry season, indicating that, although a strong influence of net radiation in the evaporative loss is present, to a large extent the evapotranspiration fluxes are coupled to the biotic control of stomatal closure in the vegetation, especially in the pasture and during dry periods.
Simulação numérica da dispersão do sulfeto de hidrogênio emitido por um reator UASB para tratamento de esgoto doméstico
Authors: Augusto Matheus Ribeiro , Calheiros Herlane Costa , Carvalho Vanessa Silveira Barreto
Published: February 2017

O tratamento anaeróbio de águas residuárias pode produzir elevadas concentrações de sulfeto de hidrogênio (H2S), substância que apresenta forte odor, além de ser corrosivo e tóxico. Alguns dos métodos existentes para o controle do H2S demandam elevado custo de implantação e operação e, portanto, não são adotados. Dessa forma, o planejamento adequado da instalação de uma estação de tratamento de esgoto (ETE) pode auxiliar na prevenção do impacto e de possíveis problemas com a população. Modelos matemáticos de dispersão atmosférica podem ser aplicados previamente para verificar o alcance do poluente e, portanto, subsidiar a definição do local mais adequado para instalação de uma ETE. Dessa forma, o objetivo deste trabalho foi analisar a dispersão atmosférica do H2S proveniente de uma unidade anaeróbia de tratamento de águas residuárias localizada em um bairro rural do município de Itajubá, MG, Brasil. Para isso, foi aplicado o modelo gaussiano AERMOD utilizando-se dados reais da taxa de emissão do poluente no reator anaeróbio, além de informações meteorológicas e geofísicas (relevo e uso do solo). Como resultado das simulações verificou-se que a pluma de odor foi orientada pelo relevo e se concentrou nas proximidades da unidade de tratamento, limitando o impacto ao bairro rural. O vento também exerceu influência direta na orientação do H2S para o período 1. No entanto, para o período 2, não se verificou a mesma tendência. Dessa maneira, constatou-se que a análise de características meteorológicas (principalmente a direção predominante dos ventos) e geofísicas da região e a aplicação de modelos matemáticos podem auxiliar na escolha do local mais adequado para a instalação de uma ETE.
Ocorrência e remoção de estrogênios por processos de tratamento biológico de esgotos
Authors: Cunha Danieli Lima da , Paula Lícia Murito de , Camargo da Silva Samuel Muylaert , Bila Daniele Maia , Fonseca Estefan Monteiro da , Mota Oliveira Jaime Lopes da
Published: February 2017

Os estrogênios são micropoluentes capazes de causar alterações no sistema endócrino de organismos aquáticos. Uma das principais fontes da sua introdução no meio hídrico é através do lançamento de esgotos domésticos. Este artigo apresenta uma revisão sobre a ocorrência dos estrogênios estrona, estradiol, estriol e etinilestradiol em esgotos brutos e tratados e em águas superficiais, bem como sobre sua remoção por diferentes processos de tratamento biológico de esgoto. Os poucos trabalhos realizados no Brasil mostram que a concentração desses compostos nestas matrizes é expressiva. Além disso, foi observado um decaimento nas concentrações desses estrogênios do esgoto bruto ao tratado. Os sistemas aeróbios, como lodos ativados, mostraram melhor desempenho na remoção de estrogênios, sobretudo por meio da sorção ao lodo. No entanto, pouco se sabe sobre os mecanismos de degradação de tais compostos nestes processos e sobre o comportamento de seus conjugados. Portanto, os processos de tratamento biológico de esgoto representam uma barreira à introdução de estrogênios nos corpos hídricos.
Secas e seus impactos no município de Boqueirão, PB, Brasil
Authors: Farias André Aires de , De Sousa Francisco de Assis Salviano , Moraes Neto João Miguel , Alves Anailson De Sousa
Published: February 2017

Secas são fenômenos naturais que ocorrem quando a precipitação é inferior às médias pluviométricas de uma determinada região. Contudo, não há um consenso para se definir o real significado do tema, em razão de que as variáveis hidrometeorológicas e socioeconômicas são diferentes nas diversas regiões do mundo. Objetivou-se caracterizar e analisar as secas e seus impactos no município de Boqueirão - PB. Para se identificar as secas foi utilizado o Índice Padronizado de Precipitação (IPP) com dados de 1963-2014. Com relação aos impactos, foram analisados dados referentes à agricultura (de 2011, 2012 e 2013), dados da pecuária e de produtos agropecuários produzidos nos anos de 2011, 2012, 2013 e 2014. As secas mais graves no município de Boqueirão ocorreram nos anos de 1980-1982, 1998-2000 e 2012-2013. Destas, a mais impactante foi a de 1998-2000. Essa seca reduziu drasticamente a produção agropecuária e o abastecimento de água da região. Os impactos mais intensos durante a seca 2012-2014 ocorreram em 2012 e 2013. As culturas agrícolas temporárias foram mais impactadas do que as permanentes. Isso ocorreu porque a maioria das permanentes eram irrigadas, diferente das temporárias. A maior redução de animais também ocorreu durante 2012 e 2013, com uma relação direta entre precipitação e o efetivo dos rebanhos. Não houve redução do valor da produção em função das secas.
Avaliação do uso de extratos vegetais para controle da hemoncose em ovinos naturalmente infectados
Authors: Gonçalves Coêlho Matheus Diniz , Xavier Thalyta Baldim , Da Costa Jaqueline Fabiana , Rodrigues Maciel Lucas Tobias , Ormachea Bozo Lilian Saito , Da Silva Coêlho Francine Alves , Akisue Gokithi
Published: February 2017

Sheep husbandry is considered an important economic practice in Brazil. However, there are problems associated with this practice. Haemonchosis stands out among these, and is known among sheep farmers for being a difficult disease to treat. Haemonchus contortus is considered the main helminth parasite of sheep, due to the fact that it is the only direct blood-sucking parasite, which can cause anemia, weight loss, submandibular swelling (mumps), low quality of meat and wool, and death of a large percentage of the herd. Currently, the predominant treatment is allopathic medicines, but resistance is increasing due to their repetitive use. In this sense, herbal medicine has emerged as a promising alternative. This study therefore aimed to evaluate the in vivo anti-parasitic activity of three plant extracts: hydroalcoholic extracts obtained by the percolation of Lepidium didymum and Momordica charantia and aqueous extract of Tagetes minuta. Animals of the Santa Inês breed were screened to identify parasitized specimens and separated into four groups of six animals each. One was used as an untreated control group, and the others were treated with 200 mg/day (5 mg/kg body weight) of the three extracts for 5 days. After treatment, EPG (eggs per gram of feces) was determined by the Mac Master method with modification. The animals in the groups treated with extracts of L. didymum and M. charantia showed a significant reduction (p <0.05) of EPG. These extracts may therefore be useful in the treatment of sheep haemonchosis.
Hybrid gravitational microfiltration system for drinking water purification
Authors: Yamaguchi Natália Ueda , Liwa Abe Silvia Amélia , Silva Medeiros Flávia Vieira da , Salcedo Vieira Angélica Marquetotti , Bergamasco Rosangela
Published: February 2017

This study evaluates the application of a polymeric microfiltration membrane in a gravitational filtration module and its combination with granular activated carbon (GAC) impregnated with copper, resulting in a hybrid process. The proposed system would be used to improve the quality of water for human consumption in developing countries.  Permeate flux, pH, Escherichia coli removal, color, turbidity and free chlorine removals were evaluated in the applied process. Instrumental techniques, such as N2 adsorption at 77 K, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) analyses were used to characterize the proposed membrane and adsorbent. The GAC ensured higher chlorine removals, as well as higher permeate flux. Furthermore, the GAC impregnated with copper oxide nanoparticles exhibited higher Escherichia coli removal. Therefore, the hybrid gravitational membrane system applying GAC impregnated with copper oxide could be considered as a potential alternative point-of-use treatment to improve the quality of water for human consumption.
Computing minimal interpolants in $C^{1,1}(\mathbb R^d)$
Authors: Herbert-Voss Ariel , Hirn Matthew J. , McCollum Frederick
Published: February 2017

We consider the following interpolation problem. Suppose one is given a finite set

E \subset \mathbb R^d

, a function

f \colon E \to \mathbb R

, and possibly the gradients of

f

at the points of

E

. We want to interpolate the given information with a function

F \in C^{1,1}(\mathbb R^d)

with the minimum possible value of Lip

(\nabla F)

. We present practical, efficient algorithms for constructing an

F

such that Lip

(\nabla F)

is minimal, or for less computational effort, within a small dimensionless constant of being minimal.
The double of the doubles of Klein surfaces
Authors: Costa Antonio F. , Cristofori Paola , Porto Ana M.
Published: February 2017

A Klein surface is a surface with a dianalytic structure. A double of a Klein surface

X

is a Klein surface

Y

such that there is a degree two morphism (of Klein surfaces)

Y \to X

. There are many doubles of a given Klein surface and among them the so-called natural doubles which are: the complex double, the Schottky double and the orienting double. We prove that if

X

is a non-orientable Klein surface with non-empty boundary, the three natural doubles, although distinct Klein surfaces, share a common double: “the double of doubles” denoted by

DX

. We describe how to use the double of doubles in the study of both moduli spaces and automorphisms of Klein surfaces. Furthermore, we show that the morphism from

DX

to

X

is not given by the action of an isometry group on classical surfaces.
Hypergroup properties for the deltoid model
Authors: Bakry Dominique , Zribi Olfa
Published: February 2017

We investigate the hypergroup property for the family of orthogonal polynomials associated with the deltoid curve in the plane, related to the

A_2

root system. This provides also the same property for another family of polynomials related to the

G_2

root system.
Multiplicity theorems for nonlinear nonhomogeneous Robin problems
Authors: Papageorgiou Nikolaos S. , Rădulescu Vicenţiu D.
Published: February 2017

We study a nonlinear Robin boundary value driven by a nonhomogeneous differential operator with a Carathéodory reaction and we look for multiple nontrivial solutions with sign information. We prove four such multiplicity theorems producing three nontrivial solutions, for resonant problems and for problems in which no global growth restriction is assumed on the reaction. Also, in the semilinear case, we show that we can have four nontrivial solutions, by producing a second nodal solution.
Interpolation of data by smooth nonnegative functions
Authors: Fefferman Charles , Israel Arie , Luli Garving K.
Published: February 2017

We prove a finiteness principle for interpolation of data by nonnegative

C^m

and

C^{m−1,1}

functions. Our result raises the hope that one can start to understand constrained interpolation problems in which, e.g., the interpolating function

F

is required to be nonnegative.