bluuebunny/crossref_metadata_2025 huggingface dataset:
The earliest dental prosthesis in Celtic Gaul? The case of an Iron Age burial at Le Chêne, France
Authors: Seguin Guillaume , d'Incau Emmanuel , Murail Pascal , Maureille Bruno
Published: March 2015

The discovery of an iron pin in place of an upper incisor tooth from a La Tène burial at Le Chêne in northern France may represent one of the earliest examples of a dental implant in Western Europe. The body was that of a young woman who had been buried in a richly furnished timber chamber. The iron pin may have been inserted during life to replace a lost tooth, or before burial to restore the visual integrity of the corpse. The concept of the dental prosthesis may have been taken from the Etruscans by returning Celtic mercenaries, although dental implants of this specific kind have not been found in Etruscan contexts.
Wroxeter and the end of Roman Britain
Authors: Lane Alan
Published: March 2015

When and how did urban life in Roman Britain end? The excavations conducted by Philip Barker at Wroxeter from 1966–1990 produced evidence suggesting a post-Roman phase of urban activity that continued into the sixth or seventh century AD, up to 200 years beyond the traditionally accepted chronology. Careful re-examination of the evidence, however, throws doubt on these claims. More recent work on Late Roman Britain coupled with new discoveries in Wales and the west challenges the evidence for the post-Roman survival of Wroxeter as an urban centre and suggests that it may have been largely abandoned, along with other Roman towns, in the late fourth or early fifth century AD.
On thin ice: problems with Stanford and Bradley's proposed Solutrean colonisation of North America
Authors: O'Brien Michael J. , Boulanger Matthew T. , Collard Mark , Buchanan Briggs , Tarle Lia , Straus Lawrence G. , Eren Metin I.
Published: March 2015

Across Atlantic ice: the origin of America's Clovis culture(Stanford & Bradley 2012) is the latest iteration of a controversial proposal that North America was first colonised by people from Europe rather than from East Asia, as most researchers accept. The authors, Dennis Stanford and Bruce Bradley, argue that Solutrean groups from southern France and the Iberian Peninsula used watercraft to make their way across the North Atlantic and into North America during the Last Glacial Maximum (LGM). According to Stanford and Bradley, this 6000km journey was facilitated by a continuous ice shelf that provided fresh water and a food supply.AcrossAtlantic ice has received a number of positive reviews. Shea (2012: 294), for example, suggests that it is “an excellent example of hypothesis-building in the best tradition of processual archaeology. It challenges American archaeology in a way that will require serious research by its opponents”. Runnels (2012) is equally enthusiastic.
Solutreanism
Authors: O'Brien Michael J. , Boulanger Matthew T. , Collard Mark , Buchanan Briggs , Tarle Lia , Straus Lawrence G. , Eren Metin I.
Published: March 2015

The comments of Stanford and Bradley (above) do not address our criticisms and obfuscate the topic at hand with irrelevant data (e.g. the south-to-north movement of fluted points through the Ice Free Corridor), nonexistent data (e.g. ‘under the water’ or ‘destroyed sites’), and questionable data (e.g. Meadowcroft and Cactus Hill are by no means widely accepted, nor are Stanford and Bradley's ‘eight LGM sites’ in the mid-Atlantic region). Before touching on some of these points, we direct the reader to several recent articles (e.g. Morrow 2014; Raff & Bolnick 2014) that provide new evidence or arguments inconsistent with a trans-Atlantic migration, including the fact that DNA from the Clovis Anzick child (Montana) shows no European ancestry (Rasmussenet al. 2014). Although Stanford and Bradley describe their Solutrean ‘solution’ (Stanford & Bradley 1999) to the Pleistocene colonisation of North America as ‘testable’, their position is that the idea is correct until falsified. They propose that their colleagues have yet to provide sufficient ‘critiques’ or ‘challenges’ to discount it (see also Collins 2012; Collinset al. 2013). Yet they are the ones proposing a hypothesis inconsistent with overwhelming multidisciplinary evidence, and they ignore results of tests that do not support their claims.
Impact of a tannin extract on digestibility, ruminal fermentation and duodenal flow of amino acids in steers fed maize silage and concentrate containing soybean meal or canola meal as protein source
Authors: ÁVILA S. C. , KOZLOSKI G. V. , ORLANDI T. , MEZZOMO M. P. , STEFANELLO S.
Published: March 2015

Four Holstein steers (297 ± 56 kg of body weight (BW)) fitted with duodenal cannula and rumen catheter, were housed in metabolism cages and used in a 4 × 4 Latin Square trial to evaluate the effect of both protein source andAcacia mearnsiitannin extract on digestibility, ruminal fermentation, rumen microbial protein synthesis, N utilization and on duodenal flow of individual amino acids. The diet was offered at restricted amount of 25 g of dry matter (DM)/kg BW and consisted of maize silage plus concentrate, in a proportion of 0·7:0·3 (DM basis) respectively. Concentrate was formulated with either soybean meal or canola meal as protein source, with or without 50 g/kg ofA. mearnsiitannin extract (i.e. 15 g/kg of total dietary DM). There was no effect of protein source on most variables. The apparent and true organic matter (OM) digestibilities, as well as neutral detergent fibre (NDF) digestibility were negatively affected by tannin extract inclusion without, however, affecting digestible OM intake. The amount of nitrogen (N) excreted in faeces increased whereas the urinary N excretion decreased in tannin extract treatments. No interaction time × treatment was detected for any rumen variable and no treatment effect was observed for rumen fluid pH and reducing sugars concentration. Rumen fluid concentration of ammonia N was lower for the canola meal plus tannin extract treatment. Rumen concentration ofα-amino compounds was not affected by tannin extract but was higher when canola meal was the protein source. The duodenal flow of OM, total N,α-amino N and non-ammonia non-microbial N increased with tannin extract inclusion, whereas the duodenal flow of microbial N was not affected by treatment. For both protein sources, the amount of most individual amino acids flowing to the duodenum increased due to tannin extract addition. In conclusion, the dietary inclusion of 15 g/kg DM of tannin extract fromA. mearnsiiimproved the amino acid supply independently of whether the protein source was canola meal or soybean meal, without affecting the amino acid profile, to steers fed maize silage plus concentrate, with a minor but significant impact on OM digestibility.
The War of Translation: Colonial Education, American English, and Tagalog Slang in the Philippines
Authors: Rafael Vicente L.
Published: March 2015

This paper examines the role of language in nationalist attempts at decolonization. In the case of the Philippines, American colonial education imposed English as the sole medium of instruction. Native students were required to suppress their vernacular languages so that the classroom became the site for a kind of linguistic war, or better yet, the war of translation. Nationalists have routinely denounced the continued use of English as a morbid symptom of colonial mentality. Yet, such a view was deeply tied to the colonial notion of the sheer instrumentality of language and the notion that translation was a means for the speaker to dominate language as such. However, other practices of translation existed based not on domination but play seen in the classroom and the streets. Popular practices of translation undercut colonial and nationalist ideas about language, providing us with an alternative understanding of translation in democratizing expression in a postcolonial context.
Fricative patterning in aspirating versus true voice languages
Authors: NICOLAE ANDREEA C. , NEVINS ANDREW
Published: March 2015

Building on the empirical insights of Beckman, Jessen & Ringen (2013), we compare the fricatives within the laryngeal systems of Russian and Turkish on the premise that the former is a final devoicing language, while the latter is not, but instead has alternations based on processes of intervocalic voicing and final fortition. This view has consequences for the analysis of fricatives in Russian vs. Turkish: Russian fricatives undergo final devoicing, while Turkish fricatives do not. By contrast, unlike Russian fricatives, Turkish fricatives induce [spread glottis] assimilation in following sonorants. We show that these differences are upheld in three phonetic studies, extending the relevance of the ‘laryngeal realism’ hypothesis to fricatives as well as stops.
Middle-passive voice in Albanian and Greek
Authors: MANZINI M. RITA , ROUSSOU ANNA , SAVOIA LEONARDO M.
Published: March 2015

In this paper we consider middle-passive voice in Greek and Albanian, which shows a many-to-many mapping between LF and PF. Different morphosyntactic shapes (conditioned by tense or aspect) are compatible with the same set of interpretations, which include the passive, the reflexive, the anticausative, and the impersonal (in Albanian only). Conversely, each of these interpretations can be encoded by any of the available morphosyntactic structures. Specialized person inflections (in Greek and Albanian), the clitic$u$(Albanian) and the affix -th- (Greek) lexicalize the internal argument (or the sole argument of intransitive in Albanian) either as a variable, which is LF-interpreted as bound by the EPP position (passives, anticausatives, reflexives) or as generically closed (impersonals, in Albanian only). The ambiguity between passives, anticausatives and reflexives depends on the interpretation assigned to the external argument (generic closure, suppression or unification with the internal argument respectively). In perfect tenses, auxiliaryjam‘be’ in Albanian derives the expression of middle-passive voice due to its selectional requirement for a participle with an open position. Crucially, no hidden features/abstract heads encoding interpretation are postulated, nor any Distributed Morphology-style realizational component.
Injection and induction acceleration of Ar3+ in the KEK Digital Accelerator
Authors: Liu X. , Yoshimoto T. , Takayama K. , Adachi T. , Kadokura E. , Munemoto N. , Takano S. , Kawakubo T. , Okamura K. , Kobayashi H. , Hirose M.
Published: March 2015

Four microseconds long Ar3+ beam with injection energy of 15 keV/u has been injected into the Digital Accelerator of the High-Energy Accelerator Research Organization. Beam production, transportation, and injection are described as well as machine properties. Results of a free running experiment under static magnetic field and longitudinal confinement and acceleration under a fast ramping magnetic field are presented in detail with a brief discussion on the beam lifetime.
Combined inhibitory effects of low temperature and N-acetyl-l-cysteine on the postovulatory aging of mouse oocytes
Authors: Li Qian , Cui Long-Bo
Published: March 2015

The postovulatory aging of oocytes eventually affects the development of oocytes and embryos. Oxidative stress is known to accelerate the onset of apoptosis in oocytes and influence their capacity for fertilisation. This study aimed to reveal the roles of temperature and the antioxidant N-acetyl-l-cysteine in preventing the aging of postovulatory mouse oocytes. First, newly ovulated mouse oocytes were cultured at various temperature and time combinations in HCZB medium with varying concentrations of N-acetyl-l-cysteine to assess signs of aging and developmental potential. When cultured in HCZB with 300 μM N-acetyl-l-cysteine at different temperature and incubation time combinations (namely 25°C for 12 h, 15°C for 24 h and 5°C for 12 h), the increase in the susceptibility of oocytes to activating stimuli was efficiently prevented, and the developmental potential was maintained following Sr2+ activation or in vitro fertilisation. After incubation at either 15°C for 36 h or 5°C for 24 h, oocytes that had decreased blastocyst rates displayed unrecoverable abnormal cortical granule distribution together with decreased BCL2 levels, total glutathione concentrations and glutathione/glutathione disulphide (GSH/GSSG) ratios. In conclusion, postovulatory oocyte aging could be effectively inhibited by appropriate N-acetyl-l-cysteine addition at low temperatures. In addition, a simple method for the temporary culture of mature oocytes was established.
A Tool for Local Thickness Determination and Grain Boundary Characterization by CTEM and HRTEM Techniques
Authors: Kiss Ákos K. , Rauch Edgar F. , Pécz Béla , Szívós János , Lábár János L.
Published: March 2015

A new approach for measurement of local thickness and characterization of grain boundaries is presented. The method is embodied in a software tool that helps to find and set sample orientations useful for high-resolution transmission electron microscopic (HRTEM) examination of grain boundaries in polycrystalline thin films. The novelty is thesimultaneoustreatment of the two neighboring grains and orienting both grains and the boundary planesimultaneously. The same metric matrix-based formalism is used for all crystal systems. Input into the software tool includes orientation data for the grains in question, which is determined automatically for a large number of grains by the commercial ASTAR program. Grain boundaries suitable for HRTEM examination are automatically identified by our software tool. Individual boundaries are selected manually for detailed HRTEM examination from the automatically identified set. Goniometer settings needed to observe the selected boundary in HRTEM are advised by the software. Operation is demonstrated on examples from cubic and hexagonal crystal systems.
Maintaining everyday life in a family with a dying parent: Teenagers' experiences of adapting to responsibility
Authors: Melcher Ulrica , Sandell Rolf , Henriksson Anette
Published: March 2015

Objective:

Teenagers are living through a turbulent period in their development, when they are breaking away from the family to form their own identities, and so they are particularly vulnerable to the stressful situation of having a parent affected by a progessive and incurable illness. The current study sought to gain more knowledge about the ways that teenagers themselves describe living in a family with a seriously ill and dying parent. More specifically, the aims were to describe how teenagers are emotionally affected by everyday life in a family with a dying parent and to determine how they attempt to adapt to this situation.

Method:

The study employed a descriptive and interpretive design using qualitative content analysis. A total of 10 teenagers (aged 14–19 years, 7 boys and 3 girls) participated through repeated, individual, informal interviews that were carried out as free-ranging conversations.

Results:

While contending with their own vulnerable developmental period of life, the teenagers were greatly affected by their parent's illness and took on great responsibility for supporting their parents and siblings, and for maintaining family life. Lacking sufficient information and support left them rather unprepared, having to guess and to interpret the vague signs of failing health on their own, with feelings of uncertainty and loneliness as a consequence.

Significance of Results:

Support from healthcare professionals should be designed to help and encourage parents to have open communications about their illness with their teenaged children. Our results add further support to the literature, reinforcing the need for an approach that uses a systemic perspective and considers the family to be the appropriate unit of care and offers a suitable support system.
Observational aspects of AGN jets at high energy
Authors: Kataoka Jun
Published: March 2015

For the last two decades, significant and dramatic progress has been made in understanding astrophysical jet sources, particularly in the X-ray and gamma-ray energy bands. For example, the Chandra X-ray observatory reveals a number of AGN jets extending from kpc to Mpc scales. More recently, the Fermi Gamma-ray Space Telescopes launched in 2008 started monitoring the gamma-ray sky with excellent sensitivity of about ten times greater than that of EGRET onboard CGRO, and has detected more than 2,000 sources (mostly AGNs) as of 2014. Moreover, Fermi-LAT has discovered gamma-ray emissions not only from blazars but from a dozen radio galaxies not previously known to emit gamma-rays. Closer to home, the Fermi-bubbles were discovered to extend 50 degrees above and below the Galactic center. These large scale diffuse gamma-ray structures are similar in structure to AGN lobes such as those seen in Cen A and provide evidence for past activity in our Galactic center. In this review, I will first summarize recent highlights of large scale jets in radio galaxies, specifically resolved by the Chandra X-ray observatory. Next I will move on to the gamma-ray sky to present some highlights from Fermi-LAT observations of “misaligned” blazars, namely radio galaxies. I will discuss a unification scheme connecting blazars and misaligned radio galaxies. In the last part, I will also briefly comment on recent multiband observations of the Fermi-bubble and possible impacts on the AGN jet physics in the near future.
The connection between the 15 GHz radio and gamma-ray emission in blazars
Authors: Max-Moerbeck W. , Richards J. L. , Hovatta T. , Pavlidou V. , Pearson T. J. , Readhead A. C. S. , King O. G. , Reeves R.
Published: March 2015

Since mid-2007 we have carried out a dedicated long-term monitoring programme at 15 GHz using the Owens Valley Radio Observatory 40 meter telescope (OVRO 40m). One of the main goals of this programme is to study the relation between the radio and gamma-ray emission in blazars and to use it as a tool to locate the site of high energy emission. Using this large sample of objects we are able to characterize the radio variability, and study the significance of correlations between the radio and gamma-ray bands. We find that the radio variability of many sources can be described using a simple power law power spectral density, and that when taking into account the red-noise characteristics of the light curves, cases with significant correlation are rare. We note that while significant correlations are found in few individual objects, radio variations are most often delayed with respect to the gamma-ray variations. This suggests that the gamma-ray emission originates upstream of the radio emission. Because strong flares in most known gamma-ray-loud blazars are infrequent, longer light curves are required to settle the issue of the strength of radio-gamma cross-correlations and establish confidently possible delays between the two. For this reason continuous multiwavelength monitoring over a longer time period is essential for statistical tests of jet emission models.
The jet of the quasar 4C+21.35 from parsec to kiloparces scales and its role in high energy photon production
Authors: Jorstad Svetlana G. , Marscher Alan P. , Morozova Daria A. , Bala Vishal , Agudo Ivan , Gómez José L. , Lähteenmäki Anne , Larionov Valeri M. , Smith Paul S. , Tornikoski Merja
Published: March 2015

We present an analysis of the parsec-scale jet structure of the quasar 4C+21.35 with a resolution of 0.1 milliarcseconds based on 63 epochs of Very Long Baseline Array observations at 43 GHz from 2007 June to 2014 May along with the Fermi LAT γ-ray light curve and multi-frequency optical photometric and polarimetric data. We find that the innermost jet of the quasar consists of a very compact core of size ~0.03 mas, as well as feature A1 located 0.16 ± 0.03 mas from the core. The distance of A1 remains fairly stable, but its position angle with respect to the core changes from -10 to +10 deg. We detect 4 superluminal knots in the inner jet with apparent speeds ranging from 10c to 20c. The first two components appeared in the jet during the high γ-ray state of the quasar from mid-2010 to early 2011, while the fourth knot appears to be connected with the γ-ray active state in late 2013 - early 2014. The first knot can be associated with the dramatic VHE flare in 2010 June and possesses an extreme Doppler factor ~60. We find that maxima in the γ-ray light curve coincide with epochs of interaction between the moving knots and the core and feature A1. This suggests that the core and A1 are recollimation shocks where γ-ray flares occur. The Chandra 0.5-6 keV image reveals the existence of X-ray emission in the kiloparsec scale jet of the quasar that can be explained via inverse Compton scattering off the cosmic microwave background by relativistic electrons if no deceleration occurs between the parsec- and kiloparsec-scale jets.
The core dominance parameter for gamma-ray loud blazars
Authors: Pei Z. Y. , Fan J. H. , Liu Y. , Xie H. J. , Gao Y. , Lin C.
Published: March 2015

In this work, we compiled 604 blazars with available core-dominance parameter, out of which 149 blazars are known to have γ-ray emissions. We compared the logR between the 149 Fermi-detected blazars (FDB) and the rest non-Fermi-detected blazars (non-FDB), and found that the average values are < logR > = 1.12 ± 0.88 for FDBs and < logR > = 0.05 ± 0.94 for non-FDBs. A K-S test shows that the probability for the distributions of FDB and non-FDB to come from the same parent distribution is P = 2.38 × 10−7. We also investigated the correlation between the core-dominance parameters and the γ-ray emission variability index (VI) for 125 FDBs (45 BLs and 79 FSRQs), and found that there is a tendency for VI to increase with the core-dominance parameter for 79 FSRQs, but there is no such tendency for 46 BLs.
Magnetization of AGN jets as imposed by leptonic models of luminous blazars
Authors: Janiak Mateusz , Sikora Marek , Moderski Rafal
Published: March 2015

Recent measurements of frequency-dependent shift of radio-core locations indicate that the ratio of the magnetic to kinetic energy flux (the σ parameter) is of the order of unity. These results are consistent with predictions of magnetically-arrested-disk (MAD) models of a jet formation, but contradict the predictions of leptonic models of γ-ray production in luminous blazars. We demonstrate this discrepancy by computing the γ-ray-to-synchrotron luminosity ratio (the q parameter) as a function of a distance from the black hole for different values of σ and using both spherical and planar models for broad-line region and dusty torus. We find that it is impossible to reproduce observed q ≫ 1 for jets with σ ≥ 1. This may indicate that blazar radiation is produced in reconnection layers or in spines of magnetically stratified jets.
Multi-wavelength polarimetry and variability study of the M87 jet
Authors: Avachat Sayali S. , Perlman Eric S. , Sparks William B , Cara Mihai , Owen Frazer N.
Published: March 2015

We present a high resolution polarimetry and variability study of the M87 jet using VLA and HST data taken during 2002 to 2008. Both data-sets have an angular resolution as high as 0.06”, which is 2-3 times better than previous observations. New morphological details are revealed in both the optical and radio, which can help to reveal the energetic and magnetic field structure of the jet. By comparing the data with previously published HST and VLA observations, we show that the jet's morphology in total and polarized light is changing significantly on timescales of ~1 decade. We compare the evolution of the inner jet (particularly the nucleus and knot HST-1), when our observations overlap with the multi-wavelength monitoring campaigns conducted with HST and Chandra. We use these data to comment on particle acceleration and main emission processes.
Time-variable linear polarization as a probe of the physical conditions in the compact jets of blazars
Authors: Marscher Alan P.
Published: March 2015

A single measurement of linear polarization of a nonthermal source provides direct information about the mean direction and level of ordering of the magnetic field. Monitoring of the polarization in blazars, combined with millimeter-wave VLBI imaging in both total and polarized intensity, has the potential to determine the geometry of the magnetic field. This is a key probe of the physical processes in the relativistic jet, such as ordered field components, turbulence, magnetic reconnections, magnetic collimation and acceleration of the jet flow, particle acceleration, and radiative processes that produce extremely luminous, highly variable nonthermal emission. Well-sampled monitoring observations of multi-waveband flux and radio-optical polarization of blazars show a variety of behavior. In some cases, the observed polarization patterns appear systematic, while in others randomness dominates. Explanations involve helical magnetic fields, turbulence, and perhaps particle acceleration that depends on the angle between the magnetic field and shock fronts that might be present. Simulations from the author's TEMZ model, with turbulent plasma crossing a standing conical shock in the jet, show that a mixture of turbulent and toroidal magnetic field can produce the level of polarization variability that is observed, even when the two field components are roughly equal.
Relativistic Alfvén Waves on the jet of BL Lacertae
Authors: Cohen Marshall H. , Meier David L.
Published: March 2015

The jet of BL Lac displays transverse patterns that propagate downstream superluminally. We suggest that they are transverse Alfvén waves propagating on the longitudinal component of a helical magnetic field. The speed of the wave adds relativistically to the speed of the beam, and the apparent speed of the pattern is greater than the beam speed. Models for the jet and the MHD waves give values for the Lorentz factor of the beam of 3–4.4 and pitch angle of the helical magnetic field of 43° - 65°. These are consistent with other estimates, if the beam and pattern speeds are allowed to differ.
Spectra and fast multi-wavelength variability of compact jets powered by internal shocks
Authors: Malzac Julien , Drappeau Samia
Published: March 2015

The emission of steady compact jets observed in the hard spectral state of X-ray binaries is likely to be powered by internal shocks caused by fluctuations of the outflow velocity. The dynamics of the internal shocks and the resulting spectral energy distribution (SED) of the jet is very sensitive to the shape of the Power Spectral Density (PSD) of the fluctuations of the jet Lorentz factor. It turns out that Lorentz factor fluctuations injected at the base of the jet with a flicker noise power spectrum (i.e. P(f) ∝1/f) naturally produce the canonical flat SED observed from radio to IR band in X-ray binary systems in the hard state. This model also predicts a strong, wavelength dependent, variability that resembles the observed one. In particular, strong sub-second variability is predicted in the infrared and optical bands. The assumed fluctuations of the jet Lorentz factor are likely to be triggered by the variability of the accretion flow which is best traced by the X-ray emission. In the case of GX339-4 for which high quality and simultaneous multi-wavelength data are available, we performed simulations assuming that the fluctuation of the jet Lorentz factor have the same PSD as the observed X-ray PSD. The synthetic SED calculated under this assumption provides a remarkable match to the observed radio to IR SED. In this case the model also produces strong mid-infrared spectral variability that is comparable to that reported in this source.
Lepton-hadronic processes and high-energy neutrinos in NGC 1275
Authors: Fraija N. , Marinelli A. , Luviano-Valenzuela U. , Galván-Gaméz A. , Peterson-Bórquez C.
Published: March 2015

The nearby active galaxy NGC 1275, has been widely detected from radio to gamma rays. Its spectral energy distribution (SED) shows a double-peak feature, which is well explained by synchrotron self-Compton (SSC) model. However, recent TeV detections might suggest that very-high-energy γ-rays (E⩾100 GeV) may not have a leptonic origin. We test a lepto-hadronic model to describe the whole SED through SSC emission and neutral pion decay resulting from pγ interactions. Also, we estimate the neutrino events expected in a km3 Cherenkov telescope.
Hadronic flares and associated neutrinos for Markarian 421
Authors: Marinelli Antonio , Patricelli Barbara , Fraija Nissim
Published: March 2015

Markarian 421 (Mrk 421) is one of the brightest, fastest and closest BL Lac objects known. Its very high energy (VHE) spectrum has been successfully modeled with both leptonic and hadronic models and no conclusive results have been achieved yet about the origin of its VHE emission. Here we investigate the possibility that a fraction of the VHE flares of Mrk 421 are due to hadronic processes and calculate the expected associated neutrino flux. We introduce the obtained neutrino flux in a Monte Carlo simulation to see the expectation for a km3 Cherenkov neutrino telescope.
Influence of an AGN complex photon field on the jet bulk Lorentz factor through Compton rocket effect
Authors: Vuillaume Thomas , Henri Gilles , Petrucci Pierre-Olivier
Published: March 2015

In this work, we study the acceleration of hot plasma to relativistic speed through the Compton rocket effect which is viable in the two-flow paradigm.
Understanding jets from sources straddling the Fanaroff-Riley divide
Authors: Kharb Preeti , Stanley Ethan , Lister Matthew , Marshall Herman , O'Dea Chris , Baum Stefi
Published: March 2015

Results from Chandra-HST-VLA observations of 13 hybrid sources are presented. Data from ten sources in the literature are analysed along with new data from three hybrid blazars belonging to the MOJAVE sample. Studies of such hybrid sources displaying both FRI and FRII jet characteristics could provide the key to resolving the long-standing Fanaroff-Riley dichotomy issue. A majority of the 13 hybrid sources show FRII-like total radio powers, i.e., they are “hybrid” in radio morphology but not in total radio power. VLBI observations of ten of the 13 sources show that the X-ray jet is on the same side as the one-sided VLBI jet. X-rays are therefore emitted from relativistically-boosted approaching jets. This is consistent with the X-ray emission being IC/CMB in origin in the majority of sources. It is not completely clear from our study that asymmetries in the surrounding medium can create hybrid sources. Hybrid radio morphologies could also be indicative of intrinsically asymmetric jets.
Extragalactic jets of broad absorption line (BAL) quasars
Authors: Kunert-Bajraszewska M. , Cegłowski M. , Roskowiński C. , Gawroński M.
Published: March 2015

Fast outflows of the ionized plasma, probably lunched in proximity of Supermassive Black Hole, are responsible for blue-shifted Broad Absorption Lines (BALs) in quasar spectrum. Outflows together with powerful jets produced in AGN are important feedback processes. Therefore, understanding physics behind BAL outflows might be a key to comprehend Galaxy Evolution as a whole. Discovery of the existence of radio-loud BAL quasars gave us another opportunity to study the BAL phenomenon, this time on the ground on radio emission. The radio emission is an additional tool to understand the BAL quasars, their orientation and age, by the VLBI imaging (detection of radio jets and their direction, size determination), the radio-loudness parameter distribution and variability study.
The 3C Chandra snapshot survey
Authors: Paggi Alessandro , Massaro F. , Harris D. E.
Published: March 2015

We present a uniform analysis of Chandra archival observations of a complete sample of ~ 200 3C sources at z < 0.5. We measured the X-ray intensity of the nuclei and of any radio hot spots and jet features with associated X-ray emission. X-ray fluxes in three energy bands, i.e., soft, medium, and hard, for all the sources analyzed are also reported. For the stronger nuclei, we also applied the standard spectral analysis, which provides the best-fit values of the X-ray spectral index and absorbing column density. In addition, a detailed analysis of bright X-ray nuclei that could be affected by pile-up has been performed. X-ray emission was detected for all the nuclei of the radio sources in our sample.
On the relation between the AGN jet and accretion disk emissions
Authors: Petrosian Vahe' , Singal Jack
Published: March 2015

AGN jets are detected via their radio and/or gamma-ray emissions while the accretion disks are detected by their optical and UV radiation. Observations of the radio and optical luminosities show a strong correlation between the two luminosities. However, part of this correlation is due to the redshift or distances of the sources that enter in calculating the luminosities from the observed fluxes and part of it could be due to the differences in the cosmological evolution of luminosities. Thus, the determination of the intrinsic correlations between the luminosities is not straightforward. It is affected by the observational selection effects and other factors that truncate the data, sometimes in a complex manner [Antonucci (2011) and Pavildouet al. (2010)]. In this paper we describe methods that allow us to determine the evolution of the radio and optical luminosities, and determine the true intrinsic correlation between the two luminosities. We find a much weaker correlation than observed and sub-linear relations between the luminosities. This has a significant implication for the jet and accretion disk physics.
Inhomogeneous SSC model for the γ-ray production in jets of microquasars
Authors: Banasinski Piotr , Bednarek Wlodek
Published: March 2015

We present an inhomogeneous synchrotron self-Compton (SSC) model for active parts of jets in low mass microquasars. We compare results of our model computed, for typical parameters of microquasars, with the sensitivity of Fermi-LAT.
The story of one Seyfert: from intriguingly ultrasoft to unremarkably average
Authors: Starling R. L. C. , Done C. , Jin C.
Published: March 2015

We use 4 broadband SEDs spanning 7 years to study the spectral shape and long term variability of RE J2248-511: an unusual AGN discovered in the extreme-UV by the ROSAT Wide Field Camera. This implies a large ultrasoft X-ray flux, which is typical of narrow-line Seyfert 1s, yet its optical lines are clearly broader than the NLS1 definition allows. Here we show that the continuum SED for the brightest epoch dataset is consistent with the mean SED of a standard quasar, and matches well to that from an XMM–SDSS sample of AGN with M/M⊙ ~ 108 and L/LEdd ~ 0.2. All the correlated optical and soft X-ray variability can be due entirely to a major absorption event. The only remarkable aspect of this AGN is that there is no measurable intrinsic X-ray absorption column in the brightest epoch dataset. The observed FUV flux is determined by the combination of this and the fact that the source lies within a local absorption hole. RE J2248-511, which once defied classification, demonstrates that characterisation of such objects requires multi-epoch, multi-wavelength campaigns.
Study of pulse structure and radiative mechanisms associations of long GRBs atz~1
Authors: Quirola Jonathan , Vásquez Nicolás
Published: March 2015

In this work, we have studied five different GRBs detected bySwift: GRB 071010B (z= 0.94), GRB 080411 (z= 1.03), GRB 080413B (z= 1.10), GRB 091208B (z= 1.06) and GRB 110715A (z= 0.82); Those GRBs, with similarzand have well defined pulses. To obtain spectral lag, we fit the light curves with a model having exponential rise and decay parts. In addition, we performed spectral analysis using three spectral models for different GRBs' regions:power law,cutoff power lawandband model. Additionaly, we releated spectral parameters such as photon index and luminosity with spectral lag. The analysis suggests that there are two types of pulses associated to specific radiation mechanisms which would reveal the radiation process of long gamma-ray bursts.
The “Christmas burst” GRB 101225A revisited
Authors: Thöne C. C. , de Ugarte Postigo A. , Fryer C. L. , Kann D. A.
Published: March 2015

Long GRBs are related to the death of massive stars and reveal themselves through synchrotron emission from highly relativistic jets. The ‘Christmas Burst’ GRB 101225A was an exceptionally long GRB with a thermal afterglow, very different from the standard GRB. Initially, no spectroscopic redshift could be obtained and SED modeling yielded z=0.33. A plausible model was a He-NS star merger where the He-star had ejected part of its envelope in the common envelope phase during inspiral. The interaction between the jet and the previously ejected shell can explains the thermal emission. We obtained deep spectroscopy of the host galaxy which leads to a correction of the redshift to z=0.847. Despite the higher redshift, our model is still valid and theoretically better justified than the alternative suggestion of a blue supergiant progenitor proposed by Levan et al. (2014) for several “ultra-long” GRBs.
Land Grabbing, Sustainable Development and Human Rights
Authors: Grant Evadné , Das Onita
Published: March 2015

Increasing investment in agricultural land by global corporations and investors from wealthy developed nations in poorer, less developed countries has significant human rights and environmental impacts. Proponents of such land deals argue that they provide opportunities for improvements in agricultural practices and generate employment, which will benefit economic growth in host countries. However, there is growing evidence that the phenomenon known as ‘land grabbing’ displaces poor and vulnerable populations and damages the environment, which in turn exacerbates poverty and food insecurity. This article explores the impact of land grabbing in Ethiopia and examines the human rights and sustainable development frameworks within which land grabbing takes place. The article argues that a human rights approach is fundamental to reconcile the sustainable development imperatives of economic development and environmental protection in the context of land grabbing. It advocates an integrated human rights and sustainable development approach as a holistic framework for assessing the impact of land grabbing and for the development of policy and regulatory responses.
As Forests Age, Their Climate Effects Shift
Authors: Shultz David
Published: March 2015

The amount of moisture transpired from leaves increases for some tree species but drops on average.
Mycobacterium tuberculosis infection of the ‘non‐classical immune cell’
Authors: Randall Philippa J , Hsu Nai‐Jen , Quesniaux Valerie , Ryffel Bernhard , Jacobs Muazzam
Published: March 2015

Mycobacterium tuberculosis can infect ‘non‐classical immune cells’, which comprise a significant constituency of cells that reside outside of those defined as ‘classical immune cells’ from myeloid or lymphoid origin. Here we address the influence of specific ‘non‐classical immune cells’ in host responses and their effects in controlling mycobacterial growth or enabling an environment conducive for bacilli persistence. The interaction of M. tuberculosis with epithelial cells, endothelial cells, fibroblasts, adipocytes, glia and neurons and downstream cellular responses that often dictate immune regulation and disease outcome are discussed. Functional integration and synergy between ‘classical’ and ‘non‐classical immune cells’ are highlighted as critical for determining optimal immune outcomes that favour the host.
Unravelling the hidden ancestry of American admixed populations
Authors: Montinaro Francesco , Busby George B.J. , Pascali Vincenzo L. , Myers Simon , Hellenthal Garrett , Capelli Cristian
Published: March 2015

The movement of people into the Americas has brought different populations into contact, and contemporary American genomes are the product of a range of complex admixture events. Here we apply a haplotype-based ancestry identification approach to a large set of genome-wide SNP data from a variety of American, European and African populations to determine the contributions of different ancestral populations to the Americas. Our results provide a fine-scale characterization of the source populations, identify a series of novel, previously unreported contributions from Africa and Europe and highlight geohistorical structure in the ancestry of American admixed populations.
Trainable hardware for dynamical computing using error backpropagation through physical media
Authors: Hermans Michiel , Burm Michaël , Van Vaerenbergh Thomas , Dambre Joni , Bienstman Peter
Published: March 2015

Neural networks are currently implemented on digital Von Neumann machines, which do not fully leverage their intrinsic parallelism. We demonstrate how to use a novel class of reconfigurable dynamical systems for analogue information processing, mitigating this problem. Our generic hardware platform for dynamic, analogue computing consists of a reciprocal linear dynamical system with nonlinear feedback. Thanks to reciprocity, a ubiquitous property of many physical phenomena like the propagation of light and sound, the error backpropagation—a crucial step for tuning such systems towards a specific task—can happen in hardware. This can potentially speed up the optimization process significantly, offering important benefits for the scalability of neuro-inspired hardware. In this paper, we show, using one experimentally validated and one conceptual example, that such systems may provide a straightforward mechanism for constructing highly scalable, fully dynamical analogue computers.
Portable Microfluidic Integrated Plasmonic Platform for Pathogen Detection
Authors: Tokel Onur , Yildiz Umit Hakan , Inci Fatih , Durmus Naside Gozde , Ekiz Okan Oner , Turker Burak , Cetin Can , Rao Shruthi , Sridhar Kaushik , Natarajan Nalini , Shafiee Hadi , Dana Aykutlu , Demirci Utkan
Published: March 2015

Timely detection of infectious agents is critical in early diagnosis and treatment of infectious diseases. Conventional pathogen detection methods, such as enzyme linked immunosorbent assay (ELISA), culturing or polymerase chain reaction (PCR) require long assay times and complex and expensive instruments, which are not adaptable to point-of-care (POC) needs at resource-constrained as well as primary care settings. Therefore, there is an unmet need to develop simple, rapid and accurate methods for detection of pathogens at the POC. Here, we present a portable, multiplex, inexpensive microfluidic-integrated surface plasmon resonance (SPR) platform that detects and quantifies bacteria, i.e., Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) rapidly. The platform presented reliable capture and detection of E. coli at concentrations ranging from ~105 to 3.2 × 107 CFUs/mL in phosphate buffered saline (PBS) and peritoneal dialysis (PD) fluid. The multiplexing and specificity capability of the platform was also tested with S. aureus samples. The presented platform technology could potentially be applicable to capture and detect other pathogens at the POC and primary care settings.
Configuration of ripple domains and their topological defects formed under local mechanical stress on hexagonal monolayer graphene
Authors: Park Yeonggu , Choi Jin Sik , Choi Taekjib , Lee Mi Jung , Jia Quanxi , Park Minwoo , Lee Hoonkyung , Park Bae Ho
Published: March 2015

Ripples in graphene are extensively investigated because they ensure the mechanical stability of two-dimensional graphene and affect its electronic properties. They arise from spontaneous symmetry breaking and are usually manifested in the form of domains with long-range order. It is expected that topological defects accompany a material exhibiting long-range order, whose functionality depends on characteristics of domains and topological defects. However, there remains a lack of understanding regarding ripple domains and their topological defects formed on monolayer graphene. Here we explore configuration of ripple domains and their topological defects in exfoliated monolayer graphenes on SiO2/Si substrates using transverse shear microscope. We observe three-color domains with three different ripple directions, which meet at a core. Furthermore, the closed domain is surrounded by an even number of cores connected together by domain boundaries, similar to topological vortex and anti-vortex pairs. In addition, we have found that axisymmetric three-color domains can be induced around nanoparticles underneath the graphene. This fascinating configuration of ripple domains may result from the intrinsic hexagonal symmetry of two-dimensional graphene, which is supported by theoretical simulation using molecular dynamics. Our findings are expected to play a key role in understanding of ripple physics in graphene and other two-dimensional materials.
MicroRNA-26a prevents endothelial cell apoptosis by directly targeting TRPC6 in the setting of atherosclerosis
Authors: Zhang Yong , Qin Wei , Zhang Longyin , Wu Xianxian , Du Ning , Hu Yingying , Li Xiaoguang , Shen Nannan , Xiao Dan , Zhang Haiying , Li Zhange , Zhang Yue , Yang Huan , Gao Feng , Du Zhimin , Xu Chaoqian , Yang Baofeng
Published: March 2015

Atherosclerosis, a chronic inflammatory disease, is the major cause of life-threatening complications such as myocardial infarction and stroke. Endothelial apoptosis plays a vital role in the initiation and progression of atherosclerotic lesions. Although a subset of microRNAs (miRs) have been identified as critical regulators of atherosclerosis, studies on their participation in endothelial apoptosis in atherosclerosis have been limited. In our study, we found that miR-26a expression was substantially reduced in the aortic intima of ApoE−/− mice fed with a high-fat diet (HFD). Treatment of human aortic endothelial cells (HAECs) with oxidized low-density lipoprotein (ox-LDL) suppressed miR-26a expression. Forced expression of miR-26a inhibited endothelial apoptosis as evidenced by MTT assay and TUNEL staining results. Further analysis identified TRPC6 as a target of miR-26a and TRPC6 overexpression abolished the anti-apoptotic effect of miR-26a. Moreover, the cytosolic calcium and the mitochondrial apoptotic pathway were found to mediate the beneficial effects of miR-26a on endothelial apoptosis. Taken together, our study reveals a novel role of miR-26a in endothelial apoptosis and indicates a therapeutic potential of miR-26a for atherosclerosis associated with apoptotic cell death.
Entrainment of heterogeneous glycolytic oscillations in single cells
Authors: Gustavsson Anna-Karin , Adiels Caroline B. , Mehlig Bernhard , Goksör Mattias
Published: March 2015

Cell signaling, gene expression and metabolism are affected by cell-cell heterogeneity and random changes in the environment. The effects of such fluctuations on cell signaling and gene expression have recently been studied intensively using single-cell experiments. In metabolism heterogeneity may be particularly important because it may affect synchronisation of metabolic oscillations, an important example of cell-cell communication. This synchronisation is notoriously difficult to describe theoretically as the example of glycolytic oscillations shows: neither is the mechanism of glycolytic synchronisation understood nor the role of cell-cell heterogeneity. To pin down the mechanism and to assess its robustness and universality we have experimentally investigated the entrainment of glycolytic oscillations in individual yeast cells by periodic external perturbations. We find that oscillatory cells synchronise through phase shifts and that the mechanism is insensitive to cell heterogeneity (robustness) and similar for different types of external perturbations (universality).