The puzzling symbiotic X-ray system 4U1700+24

Symbiotic X-ray binaries form a subclass of low-mass X-ray binary systems consisting of a neutron star accreting material from a red giant donor star via stellar wind or Roche lobe overflow. Only a few confirmed members are currently known; 4U 1700+24 is a good candidate as it is a relatively bright X-ray object, possibly associated with the late-type star V934 Her. We analysed the archive {\it XMM}-Newton and Swift/XRT observations of 4U 1700+24 in order to have a uniform high-energy ($0.3-10$ keV) view of the source. We confirmed the existence of a red-shifted O VIII Ly-$\alpha$ transition (already observed in the 2002 {\it XMM}-Newton data) in the high-resolution spectra collected via the RGS instruments. The red-shift of the line is found in all the analysed observations and, on average, it was estimated to be $\simeq 0.009$. We also observed a modulation of the centroid energy of the line on short time scales (a few days) and discuss the observations in the framework of different scenarios. If the modulation is due to the gravitational red-shift of the neutron star, it might arise from a sudden re-organization of the emitting $X$-ray matter on the scale of a few hundreds of km. Alternatively, we are witnessing a uni-polar jet of matter (with typical velocity of $1000-4000$ km s$^{-1}$) possibly emitted by the neutron star in an almost face-on system. The second possibility seems to be required by the apparent lack of any modulation in the observed $X$-ray light curve. We also note also that the low-resolution spectra (both {\it XMM}-Newton and Swift/XRT in the $0.3-10$ keV band) show the existence of a black body radiation emitted by a region (possibly associated with the neutron star polar cap) with typical size from a few tens to hundreds of meters. The size of this spot-like region reduces as the overall luminosity of 4U 1700+24 decreases.Comment: In press on A&

L'area delle risorgive nel sistema insediativo mesolitico: alcuni esempi dal pordenonese

The authors present the work undertaken on the lithic material collected in the spring area between Orcenico Superiore and Savorgnano (Pordenone-Italy). The sites are located on an NE-SW elongated Lateglacial gravel ridge, which to the present day is to be considered a stable area (i.e. preserved from alluvial and erosive action of Tagliamento and Meduna rivers). Different periods are represented in the lithic industries, spanning from the Mesolithic to the Bronze Age. This paper presents the results of the study carried out on the Mesolithic industries, mainly to be ascribed to the Castelnovian tradition. The typological composition of the assemblages shows different activities which could be associated with residential camps, without any particular specialization although this kind of interpretation could be biased by the non systematic nature of the findings. Different operational chains were in place, aiming to produce either bladelets or flakes. Raw materials are mostly of local origin, although few pieces were brought in from the Prealps, showing a North-South mobility along river routes. At the same time, there are scarce lithic materials imported from the upper part of the Udine plain, which is rich in good quality flint pebbles. Further technological and typological differences show a rather neat separation between sites on either sides of Tagliamento river. When we consider the distribution of Mesolithic sites in Friuli, a logistical settlement system seems to emerge: bigger sites are located at the edge of ecologically differentiated areas in connection with stable water sources such as the spring area between Orcenico and S. Vito al Tagliamento and the piedmont; complementary to those, task-related short-term sites characterised by less materials and fewer lithic types are found in the Prealps at middle altitude

Hubungan Dukungan Keluarga Dengan Keputusan Inisiasi Hemodialisis Pada Penderita Penyakit Ginjal Kronik Di Ruang Dahlia Rsup Prof. Dr. R. D. Kandou Manado

:Initiation hemodialysis is start of the process hemodialysis as renal replacement therapy in patients with chronic kidney disease. Family support is attitude , actions and acceptance of family to patients where family support can influence the decision of initiation hemodialysis.Purpose of this study was to analyze the relationship of the family support with the decision of initiation hemodialysis on patient chronic kidneys disease in Dahlia Room RSUP.Prof.Dr.R.D.Kandou Manado. Research method is used descriptive analytic with cross sectional design. Sampling technique in research is purposive sampling with 41 samples. Data collected by using a questionnaire.the data processed by using SPSS with chi - square test, with a significance level of 95% ( =0,05).Results showed that the number of respondents with good family support there were 63.4% respondents who did not delay the initiation of hemodialysis decision 61% of respondents, while respondents with less family support 36.6% of the respondents and delaying decisions initiation of hemodialysis 31,7% of respondents and p value = <0.001.Conclusion there is a meaningful relationship between family support with the initiation of hemodialysis decision. Recomendation for further is expected to be a reference for more research on family support with decision of initiation hemodialysis

Characterising strongly normalising intuitionistic sequent terms

This paper gives a characterisation, via intersection types, of the strongly normalising terms of an intuitionistic sequent calculus (where LJ easily embeds). The soundness of the typing system is reduced to that of a well known typing system with intersection types for the ordinary lambda-calculus. The completeness of the typing system is obtained from subject expansion at root position. This paper's sequent term calculus integrates smoothly the lambda-terms with generalised application or explicit substitution. Strong normalisability of these terms as sequent terms characterises their typeability in certain "natural'' typing systems with intersection types. The latter are in the natural deduction format, like systems previously studied by Matthes and Lengrand et al., except that they do not contain any extra, exceptional rules for typing generalised applications or substitution

A Method to Find Community Structures Based on Information Centrality

Community structures are an important feature of many social, biological and technological networks. Here we study a variation on the method for detecting such communities proposed by Girvan and Newman and based on the idea of using centrality measures to define the community boundaries (M. Girvan and M. E. J. Newman, Community structure in social and biological networks Proc. Natl. Acad. Sci. USA 99, 7821-7826 (2002)). We develop an algorithm of hierarchical clustering that consists in finding and removing iteratively the edge with the highest information centrality. We test the algorithm on computer generated and real-world networks whose community structure is already known or has been studied by means of other methods. We show that our algorithm, although it runs to completion in a time O(n^4), is very effective especially when the communities are very mixed and hardly detectable by the other methods.Comment: 13 pages, 13 figures. Final version accepted for publication in Physical Review

Flood susceptibility assessment in a highly urbanized alluvial fan: the case study of Sala Consilina (southern Italy)

Abstract. This paper deals with the risk assessment to alluvial fan flooding at the piedmont zone of carbonate massifs of the southern Apennines chain (southern Italy). These areas are prime spots for urban development and are generally considered to be safer than the valley floors. As a result, villages and towns have been built on alluvial fans which, during intense storms, may be affected by flooding and/or debris flow processes. The study area is located at the foothills of the Maddalena mountains, an elongated NW-SE trending ridge which bounds to the east the wide intermontane basin of Vallo di Diano. The area comprises a wide detrital talus (bajada) made up by coalescent alluvial fans, ranging in age from the Middle Pleistocene to the Holocene. Historical analysis was carried out to ascertain the state of activity of the fans and to identify and map the zones most hit by past flooding. According to the information gathered, the Sala Consilina fans would appear prone to debris flows; in the past these processes have produced extensive damage and loss of life in the urban area. The watershed basins feeding the fans have very low response times and may produce debris flow events with high magnitudes. Taking into account the historical damage, the fan surface morphology, and the present urban development (street orientation and hydraulic network), the piedmont area was zoned and various susceptibility classes were detected. These results may represent a useful tool for studies aiming at territorial hazard mapping and civil protection interventions

Phytosociological surveys: tools for weed science?

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Searching for supergiant fast X-ray transients with Swift

Supergiant fast X-ray transients (SFXTs) are high mass X-ray binaries (HMXBs) hosting a neutron star and an OB supergiant companion. We examine the available Swift data, as well as other new or archival/serendipitous data, on three sources: IGR J17407-2808, 2XMM J185114.3-000004, and IGR J18175-2419, whose X-ray characteristics qualify them as candidate SFXT, in order to explore their properties and test whether they are consistent with an SFXT nature. As IGR J17407-2808 and 2XMM J185114.3-000004 triggered the Burst Alert Telescope on board Swift, the Swift data allow us to provide their first arcsecond localisations, leading to an unequivocal identification of the source CXOU J174042.0-280724 as the soft X-ray counterpart of IGR J17407-2808, as well as their first broadband spectra, which can be fit with models generally describing accreting neutron stars in HMXBs. While still lacking optical spectroscopy to assess the spectral type of the companion, we propose 2XMM J185114.3-000004 as a very strong SFXT candidate. The nature of IGR J17407-2808 remains, instead, more uncertain. Its broad band properties cannot exclude that the emission originates from either a HMXB (and in that case, a SFXT) or, more likely, a low mass X-ray binary. Finally, based on the deep non-detection in our XRT monitoring campaign and a careful reanalysis of the original Integral data in which the discovery of the source was first reported, we show that IGR J18175-2419 is likely a spurious detection.Comment: Accepted for publication in Astronomy and Astrophysics. 12 pages, 11 figures, 6 table

An Experimentalist's View of Neutrino Oscillations

Neutrinos, and primarily neutrino oscillations, have undoubtedly been one of the most exciting topics in the field of high-energy physics over the past few years. The existence of neutrino oscillations would require an extension of the currently accepted description of sub-nuclear phenomena beyond the Standard Model. Compelling evidence of new physics, which seems to be pointing towards neutrino oscillations, is coming from the solar neutrino deficit and from the atmospheric neutrino anomaly. More controversial effects have been observed with artificially produced neutrinos. The present experimental status of neutrino oscillations is reviewed, as well as the planned future experimental programme, which, it is hoped, will solve most of the outstanding puzzles.Comment: 64 pages, 29 figures, to be published in Intern. J. Mod. Phys. A (2001