Relation between spectral changes and the presence of the lower kHz QPO in the neutron-star low-mass X-ray binary 4U 1636-53

We fitted the $3-180$-keV spectrum of all the observations of the neutron-star low-mass X-ray binary 4U 1636$-$53 taken with the {\it Rossi X-ray Timing Explorer} using a model that includes a thermal Comptonisation component. We found that in the low-hard state the power-law index of this component, $\Gamma$, gradually increases as the source moves in the colour-colour diagram. When the source undergoes a transition from the hard to the soft state $\Gamma$ drops abruptly; once the source is in the soft state $\Gamma$ increases again and then decreases gradually as the source spectrum softens further. The changes in $\Gamma$, together with changes of the electron temperature, reflect changes of the optical depth in the corona. The lower kilohertz quasi-periodic oscillation (kHz QPO) in this source appears only in observations during the transition from the hard to the soft state, when the optical depth of the corona is high and changes depends strongly upon the position of the source in the colour-colour diagram. Our results are consistent with a scenario in which the lower kHz QPO reflects a global mode in the system that results from the resonance between, the disc and/or the neutron-star surface, and the Comptonising corona.Comment: 9 pages, 6 figures. Accepted for publication in MNRA

Mitochondrial DNA lineages of Italian Giara and Sarcidano horses

Giara and Sarcidano are 2 of the 15 extant native Italian horse breeds with limited dispersal capability that originated from a larger number of individuals. The 2 breeds live in two distinct isolated locations on the island of Sardinia. To determine the genetic structure and evolutionary history of these 2 Sardinian breeds, the first hypervariable segment of the mitochondrial DNA (mtDNA) was sequenced and analyzed in 40 Giara and Sarcidano horses and compared with publicly available mtDNA data from 43 Old World breeds. Four different analyses, including genetic distance, analysis of molecular variance, haplotype sharing, and clustering methods, were used to study the genetic relationships between the Sardinian and other horse breeds. The analyses yielded similar results, and the FST values indicated that a high percentage of the total genetic variation was explained by between-breed differences. Consistent with their distinct phenotypes and geographic isolation, the two Sardinian breeds were shown to consist of 2 distinct gene pools that had no gene flow between them. Giara horses were clearly separated from the other breeds examined and showed traces of ancient separation from horses of other breeds that share the same mitochondrial lineage. On the other hand, the data from the Sarcidano horses fit well with variation among breeds from the Iberian Peninsula and North-West Europe: genetic relationships among Sarcidano and the other breeds are consistent with the documented history of this breed

Food and the Futurist ‘Revolution’. A Note

The Italian futurist movement dealt with all branches traditionally tied to high culture, but, at the same time, it approached ‘humbler’ fields as fashion, sports and cookery. In his french period, Marinetti met the chef Jules Maincave and they opened together a ‘Futurist’ restaurant. In 1913 Maincave published the manifesto La cuisine futuriste. In 1930, Marinetti issued in Turin the Manifesto of Futurist Cooking. The publication was preceded by a celebration dinner which took place at the Penna d’Oca restaurant in Milan. In Marinetti’s opinion, people think, dream and act according to what they eat and drink.The Futurist crusade against pasta reflects this point of view. If, on the one hand, Futurism embraced a new way of cooking, on the other hand Fascism promoted the reintroduction of traditional Italian cooking. Purpose of this essay is to delineate the contradiction between Futurism and the Fascist movement and regime, in Italy and in Europe, focusing on the aspects related to cooking.&nbsp

Bootstrap approximation for the exchange-correlation kernel of time-dependent density functional theory

A new parameter-free approximation for the exchange-correlation kernel $f_{\rm xc}$ of time-dependent density functional theory is proposed. This kernel is expressed as an algorithm in which the exact Dyson equation for the response as well as a further approximate condition are solved together self-consistently leading to a simple parameter-free kernel. We apply this to the calculation of optical spectra for various small bandgap (Ge, Si, GaAs, AlN, TiO$_2$, SiC), large bandgap (C, LiF, Ar, Ne) and magnetic (NiO) insulators. The calculated spectra are in very good agreement with experiment for this diverse set of materials, highlighting the universal applicability of the new kernel.Comment: 4 figures 5 page

Phylogenetic relationships in the “Pinnatella” clade of the moss family Neckeraceae (Bryophyta)

Peer reviewe

Evidence for impurity-induced frustration in La2CuO4

Zero-field muon spin rotation and magnetization measurements were performed in La2Cu{1-x}MxO4, for 0<x< 0.12, where Cu2+ is replaced either by M=Zn2+ or by M=Mg2+ spinless impurity. It is shown that while the doping dependence of the sublattice magnetization (M(x)) is nearly the same for both compounds, the N\'eel temperature (T_N(x)) decreases unambiguously more rapidly in the Zn-doped compound. This difference, not taken into account within a simple dilution model, is associated with the frustration induced by the Zn2+ impurity onto the Cu2+ antiferromagnetic lattice. In fact, from T_N(x) and M(x) the spin stiffness is derived and found to be reduced by Zn doping more significantly than expected within a dilution model. The effect of the structural modifications induced by doping on the exchange coupling is also discussed.Comment: 4 pages, 4 figure

YBCO microwave resonators for strong collective coupling with spin ensembles

Coplanar microwave resonators made of 330 nm-thick superconducting YBCO have been realized and characterized in a wide temperature ($T$, 2-100 K) and magnetic field ($B$, 0-7 T) range. The quality factor $Q_L$ exceeds 10$^4$ below 55 K and it slightly decreases for increasing fields, remaining 90$\%$ of $Q_L(B=0)$ for $B=7$ T and $T=2$ K. These features allow the coherent coupling of resonant photons with a spin ensemble at finite temperature and magnetic field. To demonstrate this, collective strong coupling was achieved by using DPPH organic radical placed at the magnetic antinode of the fundamental mode: the in-plane magnetic field is used to tune the spin frequency gap splitting across the single-mode cavity resonance at 7.75 GHz, where clear anticrossings are observed with a splitting as large as $\sim 82$ MHz at $T=2$ K. The spin-cavity collective coupling rate is shown to scale as the square root of the number of active spins in the ensemble.Comment: to appear in Appl. Phys. Let

Going beyond archiving - a collaborative tool for typological research

The work described in this paper aims to outline some of the design aspects for a collaborative tool for typological research. This tool is designed to allow for the collation, from multiple contributors, of linguistic examples and their analysis with regards to an open set of variation dimensions of both onomasiological and semasiological nature. The resulting knowledge base combines linguistically relevant categories of human conceptualisation (e.g. in-group, such as ethnic or family group, categories) together with their linguistic coding (e.g. in gender affixes, verbal agreement), all based on actual linguistic examples from diverse natural languages as its underlying data-driven foundation. The system is based on Semantic Web technology and hence can be queried in a flexible way that allows for combining any variation dimensions within a query (e.g. it allows to answer questions such as which languages exhibit joint attention marking by way of verbal suffixing). We will focus on design aspects relating to sustainable data. How can sustainable data for such a project be delimited? Surely, this encompasses commonly accepted aspects such as standards conformity, longevity, and accessibility, which we will address in the paper. Additionally and in particular, however, we will argue that user orientation and involvement is a critical factor. Following on from this, the tool is designed in a way that it (i) does not require linguistic users to be trained extensively in system usage, (ii) allows linguists to deploy their standard methods of data entry (e.g. interlinear glossing), and (iii) provides contributors with immediate integration of their own with previously entered data and access to the resulting analysis (i.e. querying) and research potential. The paper will roughly be structured as follows: We will describe the background and aims of the project, and contextualise it in relation to other similar projects. We will then concentrate on how sustainability is addressed, discussing a number of different facets of sustainability. This includes data storage formats, user interface and workflow modelling, knowledge base design, and system features (in particular system output). We will also outline some problems that have arisen so far and close with an outlook on future development.PARADISEC (Pacific And Regional Archive for Digital Sources in Endangered Cultures), Australian Partnership for Sustainable Repositories, Ethnographic E-Research Project and Sydney Object Repositories for Research and Teaching

Slow magnetic fluctuations and superconductivity in fluorine-doped NdFeAsO

Among the widely studied superconducting iron-pnictide compounds belonging to the Ln1111 family (with Ln a lanthanide), a systematic investigation of the crossover region between the superconducting and the antiferromagnetic phase for the Ln = Nd case has been missing. We fill this gap by focusing on the intermediate doping regime of NdFeAsO(1-x)F(x) by means of dc-magnetometry and muon-spin spectroscopy measurements. The long-range order we detect at low fluorine doping is replaced by short-range magnetic interactions at x = 0.08, where also superconductivity appears. In this case, longitudinal-field muon-spin spectroscopy experiments show clear evidence of slow magnetic fluctuations that disappear at low temperatures. This fluctuating component is ascribed to the glassy-like character of the magnetically ordered phase of NdFeAsO at intermediate fluorine doping