A device to characterize optical fibres

ATLAS is a general purpose experiment approved for the LHC collider at CERN. An important component of the detector is the central hadronic calorimeter; for its construction more than 600,000 Wave Length Shifting (WLS) fibres (corresponding to a total length of 1,120 Km) have been used. We have built and put into operation a dedicated instrument for the measurement of light yield and attenuation length over groups of 20 fibres at a time. The overall accuracy achieved in the measurement of light yield (attenuation length) is 1.5% (3%). We also report the results obtained using this method in the quality control of a large sample of fibres.Comment: 17 pages 20 figeres submitted to NIM journa

Nickel-and Fe3+-rich oxy-dravite from the Artana Mn prospect, Apuan Alps (Tuscany, Italy)

Nickel-and Fe3+-rich oxy-dravite was identified on a specimen collected in the Artana Mn prospect, Carrara, Apuan Alps, Tuscany, Italy. Oxy-dravite occurs as brownish-orange prismatic crystals, up to 0.3 mm in length, associated with quartz, carbonates, and hematite. Electron microprobe analysis gave (in wt. % – average of 7 spot analyses): SiO2 35.81, TiO2 0.41, B2 O3(calc) 10.38, Al2 O3 29.36, V2 O3 0.78, Cr2 O3 0.09, Fe2 O3 3.32, FeO 0.33, MgO 8.04, CaO 0.39, MnO 0.34, NiO 3.46, ZnO 0.40, Na2 O 2.84, F 0.29, H2 O(calc) 3.00, O = F –0.12, total 99.12. The Fe3+/Fetot ratio was calculated based on optical absorption spectroscopy. The empirical ordered formula of the studied sample is (with rounding errors)X(Na0.92 Ca0.07 □0.01)Σ1.00 Y (Mg2.01 Ni2+0.47Fe3+ Ti0.33 0.05Mn2+0.05Fe2+ Zn)Z (Al 0.05 0.05 Σ3.005.80 V0.10 Cr0.01 Fe3+) Si O (BO)V (OH) 0.09 Σ6.00 6 18 3 33W [O0.50 (OH)0.35 F0.15 ]Σ1.00 . This is an intermediate member of the dravite–oxy-dravite series. In naming it, the prefix oxy-was preferred sinceWO is very close to being larger than 0.5 atoms per formula unit. Infrared spectroscopy revealed the occurrence of significant amounts ofW(OH), and allowed to propose a specific short-range arrangements around the O(1) and O(3) sites. Unit-cell parameters are a = 15.9349(11), c = 7.2038(5) Å, V = 1584.1(2) Å3, space group R3m. The crystal structure was refined by single-crystal X-ray diffraction data to R1 = 0.0146 on the basis of 1138 unique reflections with Fo > 4σ(Fo) and 94 refined parameters. The optimized crystal-chemical formula isX(Na0.92 Ca0.07 □0.01)Σ1.00Y (Mg1.21 Al0.80 Ni2+0.47Fe3+0.26 Ti0.05 Mn2+ Zn V Cr)Z (Al 0.05 0.05 0.10 0.01 Σ3.005.00 Mg0.80 Fe3+ 0.16Fe2+) Si O (BO) O(3) O(1) (OH) 0.05 Σ6.00 6 18 3 33 [O0.50 (OH)0.35 F0.15 ]Σ1.00 . Nickel is ordered at the Y site, in agreement with results obtained on synthetic tourmalines. Oxy-dravite is likely the result of the metamorphic recrystallization of Mn-rich layers at the top of the Liassic carbonates belonging to the Marble Formation of the Apuan Alps Metamorphic Complex

Human Time-Frequency Acuity Beats the Fourier Uncertainty Principle

The time-frequency uncertainty principle states that the product of the temporal and frequency extents of a signal cannot be smaller than $1/(4\pi)$. We study human ability to simultaneously judge the frequency and the timing of a sound. Our subjects often exceeded the uncertainty limit, sometimes by more than tenfold, mostly through remarkable timing acuity. Our results establish a lower bound for the nonlinearity and complexity of the algorithms employed by our brains in parsing transient sounds, rule out simple "linear filter" models of early auditory processing, and highlight timing acuity as a central feature in auditory object processing.Comment: 4 pages, 2 figures; Accepted at PR

Role of high dose octreotide LAR for the treatment of GEP-NETs

Neuroendocrine Tumours (NETs) are a heterogeneous group of rare neoplasms that account for 0,5% of all malignancies. The increased incidence observed in the last few decades may be accounted for by increased awareness, improved diagnostic tools and a revision in the definition. The main primary sites are the gastro-entero-pancreatic (GEP) tract (62-67%), and the lung (22-27%). In patients with GEP-NETs, the strongest predictor of 5-years survival is the staging. An adequate clinical management of GEP-NETs should be multidisciplinary and should aim at assuring a good quality of life. Somatostatin (sst) analogues are widely used in these tumours, which often express sst receptors, since they are demonstrated to reduce clinical symptoms and tumour growth. Herein we explore the usefulness of doubling octreotide LAR dose in selected patients after escaping from symptoms control and/or tumour stabilization in course of treatment with standard dose

Duration of untreated illness and depression severity are associated with cognitive impairment in mood disorders

Introduction: In this study we estimated the rate and the trajectory of cognitive impairment in a naturalistic sample of outpatients with major depressive disorder (MDD) and bipolar disorder (BD) and its correlation with different variables. Materials and methods: An overall sample of 109 outpatients with MDD or BD was assessed for multiple clinical variables, including duration of untreated illness (DUI), and tested using the Montreal Cognitive Assessment (MoCA) during Major Depressive Episodes (MDE) and after remission. Correlations between MoCA scores and the clinical variables were then computed. Results: About 50% of patients with MDD and BD showed mild cognitive impairment during MDE. Improvement of cognitive function between depression and remission was significant, even though residual symptoms were observed especially in the most impaired patients. Of note, cognitive performance during depression was negatively associated with depression severity and DUI. Discussion: Present findings confirm available evidence about patterns of cognitive impairment in mood disorders, in terms of prevalence and persistence beyond remission in most severe cases. Moreover, a longer DUI was associated with worse cognitive performance during depression, and consequently with poorer outcome, underlining the importance of prompt treatment of these disorders also in light of a cognitive perspective. Keywords: bipolar disorder, cognitive dysfunction, duration of untreated illness, major depressive disorder, Montreal cognitive assessmen

Reconstructing 3D x-ray CT images of polymer gel dosimeters using the zero-scan method

In this study x-ray CT has been used to produce a 3D image of an irradiated PAGAT gel sample, with noise-reduction achieved using the ‘zero-scan’ method. The gel was repeatedly CT scanned and a linear fit to the varying Hounsfield unit of each pixel in the 3D volume was evaluated across the repeated scans, allowing a zero-scan extrapolation of the image to be obtained. To minimise heating of the CT scanner’s x-ray tube, this study used a large slice thickness (1 cm), to provide image slices across the irradiated region of the gel, and a relatively small number of CT scans (63), to extrapolate the zero-scan image. The resulting set of transverse images shows reduced noise compared to images from the initial CT scan of the gel, without being degraded by the additional radiation dose delivered to the gel during the repeated scanning. The full, 3D image of the gel has a low spatial resolution in the longitudinal direction, due to the selected scan parameters. Nonetheless, important features of the dose distribution are apparent in the 3D x-ray CT scan of the gel. The results of this study demonstrate that the zero-scan extrapolation method can be applied to the reconstruction of multiple x-ray CT slices, to provide useful 2D and 3D images of irradiated dosimetry gels

Assessing the effects of Bt maize on the non-target pest Rhopalosiphum maidis by demographic and life-history measurement endpoints

The most commercialized Bt maize plants in Europe were transformed with genes which express a truncated form of the insecticidal delta-endotoxin (Cry1Ab) from the soil bacterium Bacillus thuringiensis (Bt) specifically against Lepidoptera. Studies on the effect of transgenic maize on non-target arthropods have mainly converged on beneficial insects. However, considering the worldwide extensive cultivation of Bt maize, an increased availability of information on their possible impact on non-target pests is also required. In this study, the impact of Bt-maize on the non-target corn leaf aphid, Rhopalosiphum maidis, was examined by comparing biological traits and demographic parameters of two generations of aphids reared on transgenic maize with those on untransformed near-isogenic plants. Furthermore, free and bound phenolics content on transgenic and near-isogenic plants were measured. Here we show an increased performance of the second generation of R. maidis on Bt-maize that could be attributable to indirect effects, such as the reduction of defense against pests due to unintended changes in plant characteristics caused by the insertion of the transgene. Indeed, the comparison of Bt-maize with its corresponding near-isogenic line strongly suggests that the transformation could have induced adverse effects on the biosynthesis and accumulation of free phenolic compounds. In conclusion, even though there is adequate evidence that aphids performed better on Bt-maize than on non-Bt plants, aphid economic damage has not been reported in commercial Bt corn fields in comparison to non-Bt corn fields. Nevertheless, Bt-maize plants can be more easily exploited by R. maidis, possibly due to a lower level of secondary metabolites present in their leaves. The recognition of this mechanism increases our knowledge concerning how insect-resistant genetically modified plants impact on non-target arthropods communities, including tritrophic web interactions, and can help support a sustainable use of genetically modified crops

Post-sigh sleep apneas in mice: Systematic review and data-driven definition

Sleep apneas can be categorized as post-sigh (prevailing in non-rapid eye movement sleep) or spontaneous (prevailing in rapid eye movement sleep) according to whether or not they are preceded by an augmented breath (sigh). Notably, the occurrence of these apnea subtypes changes differently in hypoxic/hypercapnic environments and in some genetic diseases, highlighting the importance of an objective discrimination. We aim to: (a) systematically review the literature comparing the criteria used in categorizing mouse sleep apneas; and (b) provide data-driven criteria for this categorization, with the final goal of reducing experimental variability in future studies. Twenty-two wild-type mice, instrumented with electroencephalographic/electromyographic electrodes, were placed inside a whole-body plethysmographic chamber to quantify sleep apneas and sighs. Wake\u2013sleep states were scored on 4-s epochs based on electroencephalographic/electromyographic signals. Literature revision showed that highly different criteria were used for post-sigh apnea definition, the intervals for apnea occurrence after sigh ranging from 1 breath up to 20 s. In our data, the apnea occurrence rate during non-rapid eye movement sleep was significantly higher than that calculated before the sigh only in the 1st and 2nd 4-s epochs following a sigh. These data suggest that, in mice, apneas should be categorized as post-sigh only if they start within 8 s from a sigh; the choice of shorter or longer time windows might underestimate or slightly overestimate their occurrence rate, respectively

PORTULACA OLERACEA L. IN THE ERA OF GLOBALISATION: A SPECIES OF GREAT NUTRACEUTICAL VALUE

Portulaca oleracea L. is a common ruderal, synanthropic, cosmopolitan taxon, highly polymorphic, typical of warm sites (Danin and Raus, 2012; Danin et al., 2014; Danin et al., submitted). In Italy its status as a native species is doubtful (Pignatti, 1982). It is well known since the antiquity for its medicinal and nutrient qualities (Bosi et al., 2009): all parts of the plant have therapeutic properties (Gastaldo, 1987). It has been used for a long time as an analgesic, anti-inflammatory, antipyretic, diuretic, emollient, lenitive and anaphrodisiac. Many of such properties have been recently confirmed; furthermore, P. oleracea is very rich in omega-3 polyunsaturated fatty acids (Ezekwe et al., 1999), so that its use is recommended to contrast the excess of fatty acids assumed by fast foods (Picchi and Pieroni, 2005) and its seeds are good to counteract diabetes mellitus (El-Sayed, 2011)

Si and Sn doping of ε-Ga2O3 layers

Low resistivity n-type e-Ga2O3 epilayers were obtained for the first time either by adding silane to the gas phase during the metal organic vapour phase epitaxy deposition or by diffusing Sn in nominally undoped layers after the growth. The highest doping concentrations were few 1018 cm−3 and about 1017 cm−3 for Si and Sn doping, with corresponding resistivity below 1 and 10 Ω cm, respectively. Temperature dependent transport investigation in the range of 10-600 K shows a resistivity behavior consistent with the Mott law, suggesting that conduction through localized states dominates the electrical properties of Si- and Sn-doped samples. For both types of dopants, two different mechanisms of conduction through impurity band states seem to be present, each of them determining the transport behavior at the lower and higher temperatures of the measurement range.Low resistivity n-type e-Ga2O3 epilayers were obtained for the first time either by adding silane to the gas phase during the metal organic vapour phase epitaxy deposition or by diffusing Sn in nominally undoped layers after the growth. The highest doping concentrations were few 1018 cm−3 and about 1017 cm−3 for Si and Sn doping, with corresponding resistivity below 1 and 10 Ω cm, respectively. Temperature dependent transport investigation in the range of 10-600 K shows a resistivity behavior consistent with the Mott law, suggesting that conduction through localized states dominates the electrical properties of Si- and Sn-doped samples. For both types of dopants, two different mechanisms of conduction through impurity band states seem to be present, each of them determining the transport behavior at the lower and higher temperatures of the measurement range