3,051 research outputs found
Impression cytology with scanning electron microscopy: a new method in the study of conjunctival microvilli.
Caspase-independent programmed cell death triggers Ca2PO4 deposition in an in vitro model of nephrocalcinosis
We provide evidence of caspase-independent cell death triggering the calcification process in GDNF-silenced HK-2 cells
Anti-Fas (CD95/Apo-I) autoantibodies and soluble Fas levels concur in T cell depletion in HIV type 1 infection.
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
Raman Microspectroscopy Analysis in the Treatment of Acanthamoeba Keratitis
Acanthamoeba keratitis is a rare but serious corneal disease, often observed in contact lens wearers. Clinical treatment of infected patients frequently involves the use of polyhexamethylene biguanide (PHMB), a polymer used as a disinfectant and antiseptic, which is toxic also for the epithelial cells of the cornea. Prompt and effective diagnostic tools are hence highly desiderable for both starting early therapy and timely suspension of the treatment. In this work we use Raman microspectroscopy to analyse in vitro a single Acanthamoeba cell in cystic phase. In particular, we investigate the effect of PHMB at the single-cell level, providing useful information on both the underlying biochemical mechanism and the time frame for Acanthamoeba eradication in ocular infections. Furthermore, we demonstrate that Raman spectroscopy, in conjunction with standard multivariate analysis methods, allows discriminating between live and dead Acanthamoebas, which is fundamental to optimizing patients' treatment
Replica symmetric evaluation of the information transfer in a two-layer network in presence of continuous+discrete stimuli
In a previous report we have evaluated analytically the mutual information
between the firing rates of N independent units and a set of multi-dimensional
continuous+discrete stimuli, for a finite population size and in the limit of
large noise. Here, we extend the analysis to the case of two interconnected
populations, where input units activate output ones via gaussian weights and a
threshold linear transfer function. We evaluate the information carried by a
population of M output units, again about continuous+discrete correlates. The
mutual information is evaluated solving saddle point equations under the
assumption of replica symmetry, a method which, by taking into account only the
term linear in N of the input information, is equivalent to assuming the noise
to be large. Within this limitation, we analyze the dependence of the
information on the ratio M/N, on the selectivity of the input units and on the
level of the output noise. We show analytically, and confirm numerically, that
in the limit of a linear transfer function and of a small ratio between output
and input noise, the output information approaches asymptotically the
information carried in input. Finally, we show that the information loss in
output does not depend much on the structure of the stimulus, whether purely
continuous, purely discrete or mixed, but only on the position of the threshold
nonlinearity, and on the ratio between input and output noise.Comment: 19 pages, 4 figure
Approximating the limit: the interaction between 'almost' and some temporal connectives in Italian
International audienceThis paper focuses on the interpretation of the Italian approximative adverb 'almost' by primarily looking at cases in which it modifies temporal connectives, a domain which, to our knowledge, has been largely unexplored thus far. Consideration of this domain supports the need for a scalar account of the semantics of (close in spirit to Hitzeman's semantic analysis of , in: Canakis et al. (eds) Papers from the 28th regional meeting of the Chicago Linguistic Society, 1992). When paired with suitable analyses of temporal connectives, such an account can provide a simple explanation of the patterns of implication that are observed when modifies locational (e.g. 'when'), directional (e.g. 'until' and 'since'), and event-sequencing temporal connectives (e.g. 'before' and 'after'). A challenging empirical phenomenon that is observed is a contrast between the modification of and by , on the one hand, and the modification of and by the same adverb, on the other. While and behave symmetrically, a puzzling asymmetry is observed between and . To explain the asymmetry, we propose an analysis of and on which the former has the meaning of the temporal comparative 'earlier', while the latter is seen as an atomic predicate denoting temporal succession between events (Del Prete, Nat Lang Semantics 16:157-203, 2008). We show that the same pattern of implication observed for is attested when modifies overt comparatives, and propose a pragmatic analysis of this pattern that uniformly applies to both cases, thus providing new evidence for the claim that is underlyingly a comparative. A major point of this paper is a discussion of the notion of scale which is relevant for the semantics of ; in particular, we show that the notion of Horn (entailment-based) scale is not well-suited for handling modification of temporal connectives, and that a more general notion of scale is required in order to provide a uniform analysis of as a cross-categorial modifier
Influences of dietary supplementation with Lepidium meyenii (Maca) on stallion sperm production and on preservation of sperm quality during storage at 5 °C.
Stallion semen is damaged by oxidative stress during cooling and transport. Semen processing and extenders have been tested to improve the fertilizing capacity of semen and to preserve semen during transport. Dietary supplementation with natural antioxidants has been proposed to prevent oxidative damages. In this study, for the first time, the effect of dietary supplementation with Lepidium meyenii (Maca) on the characteristics of fresh and chilled stallion semen was evaluated. Maca is a traditional Andean crop used as a nutraceutical for the fertility-enhancing properties that are linked with antioxidant activity. The diet of five stallions was supplemented with 20 g of Maca powder daily for a total of 60 days. A control group of five stallions received the same diet without Maca. Semen was collected once before the administration of Maca (D0), twice during the administration at 30 and 60 days (D30 and D60), and finally twice at 30 and 60 days after the end of the administration (D90 and D120). Ejaculates were processed for cooled shipping at 5 °C and evaluated in the laboratory for total and progressive motility, acrosome integrity, and lipid peroxidation after collection and after 24, 48, and 72 h of storage. Dietary supplementation with Maca improved sperm concentration (from 213 ± 80.4 to 447 ± 73.1 × 106 spz/mL) and total sperm count (from 10,880 ± 4377 to 24,783 ± 4419 × 106 spz). The beneficial effects of Maca supplementation on motility and acrosome integrity in the raw semen were detected from the end of treatment with Maca (D60) until the end of the study (D120). Furthermore, during cooling storage, total motility, progressive motility, and acrosome integrity declined more slowly in the Maca-treated group than in the control group. Lipid peroxidation did not change during cooling storage in either group and did not show a significant difference between the two groups. In this study, the dietary supplementation with Maca increased sperm production and stabilized semen quality during chilled storage
A PMT-Block test bench
The front-end electronics of the ATLAS hadronic calorimeter (Tile Cal) is
housed in a unit, called {\it PMT-Block}. The PMT-Block is a compact instrument
comprising a light mixer, a PMT together with its divider and a {\it 3-in-1}
card, which provides shaping, amplification and integration for the signals.
This instrument needs to be qualified before being assembled on the detector. A
PMT-Block test bench has been developed for this purpose. This test bench is a
system which allows fast, albeit accurate enough, measurements of the main
properties of a complete PMT-Block. The system, both hardware and software, and
the protocol used for the PMT-Blocks characterisation are described in detail
in this report. The results obtained in the test of about 10000 PMT-Blocks
needed for the instrumentation of the ATLAS (LHC-CERN) hadronic Tile
Calorimeter are also reported.Comment: 23 pages, 10 figure
Numerical Simulation of Machining Nickel-Based Alloy
none3The phenomenological models for material flow stress and fracture, typically used in the Finite Element simulations of machining Nickel-based alloys, are often deemed to represent only certain metallurgical material states. In contrast, these models are not suitable to describe the constitutive behavior of the workpiece for different metallurgical states (i.e., annealed, aged, etc.) and, consequently, different hardness values. Since the description of the material behavior requires correct formulation of the constitutive law, new flow stress models which include also the hardness effect should be developed and used, for computer simulation of machining Nickel-based alloys. This paper describes the development of a hardness-based flow stress and fracture models for machining Inconel 718 alloy which can be applied for a wide range of work material hardness. These models have been implemented in a non-isothermal viscoplastic numerical model to simulate the influence of work material hardness on the chip formation process. The predicted results are being validated with experimental results properly carried out for this research. They are found to satisfactory predict the cutting forces, the temperature and the chip morphology from continuous to segmented chip as the hardness values changeopenDel Prete A.; Filice L.; Umbrello D.;DEL PRETE, Antonio; Filice, L.; Umbrello, D
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