5,395 research outputs found
El copyright en la era digital : nuevas estrategias de control y explotación de productos audiovisuales en Internet
El artículo describe, en primer término, las nuevas formas de distribución y consumo de productos audiovisuales con copyright que se están articulando hoy en Internet, para luego analizar, en segundo término, las estrategias que los principales grupos multimedia están implementando para preservar el copyright de estos productos y poder así explotarlos comercialmente.This paper analyses, in the one hand, the new ways of distribution and consumption of audiovisual products with copyright in Internet and, in the second hand, the main strategies the multimedia groups are performing toward the control and commodification of these products
Characterization of the Hamamatsu R11265-103-M64 multi-anode photomultiplier tube
The aim of this paper is to fully characterize the new multi-anode
photomultiplier tube R11265-103-M64, produced by Hamamatsu. Its high effective
active area (77%), its pixel size, the low dark signal rate and the capability
to detect single photon signals make this tube suitable for an application in
high energy physics, such as for RICH detectors. Four tubes and two different
bias voltage dividers have been tested. The results of a standard
characterization of the gain and the anode uniformity, the dark signal rate,
the cross-talk and the device behaviour as a function of temperature have been
studied. The behaviour of the tube is studied in a longitudinal magnetic field
up to 100 Gauss. Shields made of a high permeability material are also
investigated. The deterioration of the device performance due to long time
operation at intense light exposure is studied. A quantitative analysis of the
variation of the gain and the dark signals rate due to the aging is described.Comment: 22 page
Constraining CP violation in neutral meson mixing with theory input
There has been a lot of recent interest in the experimental hints of CP
violation in B_{d,s}^0 mixing, which would be a clear signal of beyond the
standard model physics (with higher significance). We derive a new relation for
the mixing parameters, which allows clearer interpretation of the data in
models in which new physics enters in M_12 and/or \Gamma_12. Our results imply
that the central value of the D\O\ measurement of the semileptonic CP asymmetry
in B_{d,s}^0 decay is not only in conflict with the standard model, but in a
stronger tension with data on \Delta\Gamma_s than previously appreciated. This
result can be used to improve the constraint on \Delta\Gamma or A_SL, whichever
is less precisely measured.Comment: 5 pages, 2 figures, informed of prior derivation of eq. (21), title
modifie
Subfractionation of human very low density lipoproteins by heparin-Sepharose affinity chromatography.
Very low density lipoproteins obtained from normolipidemic subjects were fractionated into subclasses by means of affinity chromatography on a heparin-Sepharose column in the presence of MnCl2. The four subfractions eluted at 0.05, 0.12, 0.20, and 0.38 M NaCl and they differed in chemical composition and apoprotein pattern. The relative amounts of apoB and apoE in subfractions increased with increasing concentrations of the NaCl eluant. Modification of the arginyl residues with 1-2 cyclohexadione demonstrated that arginine plays an important role in determining the elution pattern of VLDL. In vitro studies indicated that only fractions eluted at 0.2 and 0.5 M NaCl compete with LDL for cellular receptors. These data suggest that the various subfractions may represent VLDL at different stages of catabolism
Innate Immune Responses in the Outcome of Haploidentical Hematopoietic Stem Cell Transplantation to Cure Hematologic Malignancies
In the context of allogeneic transplant platforms, human leukocyte antigen (HLA)-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) represents one of the latest and most promising curative strategies for patients affected by high-risk hematologic malignancies. Indeed, this platform ensures a suitable stem cell source immediately available for virtually any patents in need. Moreover, the establishment in recipients of a state of immunologic tolerance toward grafted hematopoietic stem cells (HSCs) remarkably improves the clinical outcome of this transplant procedure in terms of overall and disease free survival. However, the HLA-mismatch between donors and recipients has not been yet fully exploited in order to optimize the Graft vs. Leukemia effect. Furthermore, the efficacy of haplo-HSCT is currently hampered by several life-threatening side effects including the onset of Graft vs. Host Disease (GvHD) and the occurrence of opportunistic viral infections. In this context, the quality and the kinetic of the immune cell reconstitution (IR) certainly play a major role and several experimental efforts have been greatly endorsed to better understand and accelerate the post-transplant recovery of a fully competent immune system in haplo-HSCT. In particular, the IR of innate immune system is receiving a growing interest, as it recovers much earlier than T and B cells and it is able to rapidly exert protective effects against both tumor relapses, GvHD and the onset of life-threatening opportunistic infections. Herein, we review our current knowledge in regard to the kinetic and clinical impact of Natural Killer (NK), \u3b3\u3b4 and Innate lymphoid cells (ILCs) IRs in both allogeneic and haplo-HSCT. The present paper also provides an overview of those new therapeutic strategies currently being implemented to boost the alloreactivity of the above-mentioned innate immune effectors in order to ameliorate the prognosis of patients affected by hematologic malignancies and undergone transplant procedures
DESIGN AND ANALYSIS OF AN INNOVATIVE CUBESAT THERMAL CONTROL SYSTEM FOR BIOLOGICAL EXPERIMENT IN LUNAR ENVIRONMENT
After about 50 years since the Apollo missions, Space Agencies are planning new manned missions beyond LEO,
aiming to full functional Lunar and Martian outposts. Leaving the protection of Earth’s magnetic field, human body
will be exposed by a huge amount of harmful radiations coming from both solar wind and cosmic rays, which represent
a risk for the astronauts. In order to prepare for future manned exploration missions, many biological experiments have
been conducted inside and outside the International Space Station (ISS). From these experiments, engineers and
scientists gained knowledge about biological degradation after a long period of exposure to space radiations. Similar
experiments were also carried out in small free-flyers. For example, the O/OREOS mission is built with a 3U CubeSat
that is evaluating how microorganisms can survive and can adapt to the harsh orbit environment. Small platforms, such
as CubeSats, are gaining interest for many applications including science experiments. Biological payloads require
very stable environmental conditions, implying that environment requirements are very stringent and that existing
passive thermal control systems may not be sufficient to support these class of experiments. The goal of this paper is
to describe and discuss the design of an active environmental control system suitable for supporting biological payloads
hosted onboard nanosatellites. In particular, we focused the attention on the case of a payload constituted by a bacterial
culture that needs oxygen supply for growing up. The rate of growth and vitality are measured through bacteria
metabolic parameters. The reference mission is built with a 6U CubeSat in Lunar Polar Orbit, with the main scientific
objective of measuring the effect of the lunar radiation environment on a culture of “Bacterium Deinococcus
Radiodurans”. This kind of bacteria exhibits significant resistance to ionising radiation and the survival temperature
range is 30°C ± 10°C. The thermal control system (TCS) is constituted by Stirling cryocooler, Peltier cells and heaters.
The aforementioned pieces of equipment operate on the oxygen tank and test chamber in order to control temperature
of the oxygen necessary for the growth of the bacteria. To verify the temperature requirements, two kinds of analysis
are performed: radiative analysis, to have information about the heat fluxes from space environment; and lastly, a
thermo-fluid dynamics analysis, to gather data about temperature in the test chamber. As result, it is possible to confirm
that, with the chosen TCS, the temperature requirement is verified during the mission
La industria de la música en Internet
La presente comunicación analiza algunas de las transformaciones que están operando hoy en el seno de la industria de la música a partir del surgimiento y expansión de las nuevas tecnologías digitales, tales como los reproductores de música MP3, los soportes digitales DVD y fundamentalmente Internet. Asimismo, ésta se centra en las nuevas estrategias y modelos de negocio que las grandes compañías discográficas multinacionales (Majors) están ensayando en Internet, tomando como caso de estudio el modelo de explotación que la empresa Apple está desarrollando con su reproductor de música iPod y su plataforma web iTunes, e incluyendo algunas referencias a otras plataformas web, tales como la que está desarrollando actualmente la empresa Napste
First characterization of the Hamamatsu R11265 multi-anode photomultiplier tube
The characterization of the new Hamamatsu R11265-103-M64 multi-anode photomultiplier tube is presented. The sample available in our laboratory was tested and in particular the response to single photon was extensively studied. The gain, the anode uniformity and the dark current were measured. The tube behaviour in a longitudinal magnetic field up to 100 G was studied and the gain loss due to the ageing was quantified. The characteristics and performance of the photomultiplier tube make the R11265-103-M64 particularly tailored for an application in high energy physics experiments, such as in the LHCb Ring Imaging Cherenkov (RICH) detector at LHC
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