4,197 research outputs found
Role of antiviral therapy in the natural history of hepatitis B virus-related chronic liver disease
Hepatitis B virus (HBV) infection is a dynamic state of interactions among HBV, hepatocytes, and the host immune system. Natural history studies of chronic hepatitis B (CHB) infection have shown an association between active viral replication and adverse clinical outcomes such as cirrhosis and hepatocellular carcinoma. The goal of therapy for CHB is to improve quality of life and survival by preventing progression of the disease to cirrhosis, decompensation, end-stage liver disease, hepatocellular carcinoma (HCC) and death. This goal can be achieved if HBV replication is suppressed in a sustained manner. The accompanying reduction in histological activity of CHB lessens the risk of cirrhosis and of HCC, particularly in non-cirrhotic patients. However, CHB infection cannot be completely eradicated, due to the persistence of covalently closed circular DNA in the nucleus of infected hepatocytes, which may explain HBV reactivation. Moreover, the integration of the HBV genome into the host genome may favour oncogenesis, development of HCC and may also contribute to HBV reactivation
A novel background reduction strategy for high level triggers and processing in gamma-ray Cherenkov detectors
Gamma ray astronomy is now at the leading edge for studies related both to
fundamental physics and astrophysics. The sensitivity of gamma detectors is
limited by the huge amount of background, constituted by hadronic cosmic rays
(typically two to three orders of magnitude more than the signal) and by the
accidental background in the detectors. By using the information on the
temporal evolution of the Cherenkov light, the background can be reduced. We
will present here the results obtained within the MAGIC experiment using a new
technique for the reduction of the background. Particle showers produced by
gamma rays show a different temporal distribution with respect to showers
produced by hadrons; the background due to accidental counts shows no
dependence on time. Such novel strategy can increase the sensitivity of present
instruments.Comment: 4 pages, 3 figures, Proc. of the 9th Int. Syposium "Frontiers of
Fundamental and Computational Physics" (FFP9), (AIP, Melville, New York,
2008, in press
Efecto del embolsado y deschire del cultivo de banano (Musa acuminata Colla) sobre las poblaciones de trips (Thysanoptera: Thripidae)
La producción bananera argentina está destinada exclusivamente al consumo interno y muestra deficiencias de manejo en las etapas de producción y poscosecha. Los frutos del banano son muy sensibles cuando se producen lesiones, por lo que los daños ocasionados por insectos, como los trips (Thysanoptera), favorecen la pérdida de valor comercial. El objetivo de este trabajo fue estudiar los efectos del embolsado, asociado o no al deschire, en la incidencia de trips en la floración y fructificación del banano (Musa acuminata Colla) durante dos ciclos de producción (2010-2011 y 2011-2012), en Laguna Naineck (Formosa, Argentina). Se utilizó un diseño de bloques completamente aleatorizados (RCBD) con cuatro tratamientos y cuatro repeticiones. La abundancia de los insectos se determinó en tres estratos del racimo, y la incidencia, durante la cosecha. La única especie de trips presente durante el estudio fue Frankliniella brevicaulis Hood. Se detectó un mayor número de larvas de trips en los estratos inferiores del racimo. El embolsado de los racimos con deschire redujo la incidencia de F. brevicaulis en un 54% y 66% cada ciclo de estudio respectivamente y favoreció el aumento en la longitud de los dedos con respecto al control, en 9% y 10% para el primer y segundo año de estudio, respectivamente
New Eco-gas mixtures for the Extreme Energy Events MRPCs: results and plans
The Extreme Energy Events observatory is an extended muon telescope array,
covering more than 10 degrees both in latitude and longitude. Its 59 muon
telescopes are equipped with tracking detectors based on Multigap Resistive
Plate Chamber technology with time resolution of the order of a few hundred
picoseconds. The recent restrictions on greenhouse gases demand studies for new
gas mixtures in compliance with the relative requirements. Tetrafluoropropene
is one of the candidates for tetrafluoroethane substitution, since it is
characterized by a Global Warming Power around 300 times lower than the gas
mixtures used up to now. Several mixtures have been tested, measuring
efficiency curves, charge distributions, streamer fractions and time
resolutions. Results are presented for the whole set of mixtures and operating
conditions, %. A set of tests on a real EEE telescope, with cosmic muons, are
being performed at the CERN-01 EEE telescope. The tests are focusing on
identifying a mixture with good performance at the low rates typical of an EEE
telescope.Comment: 8 pages, 6 figures, proceedings for the "XIV Workshop on Resistive
Plate Chambers and Related Detectors" (19-23 February 2018), Puerto Vallarta,
Jalisco State, Mexic
A simulation tool for MRPC telescopes of the EEE project
The Extreme Energy Events (EEE) Project is mainly devoted to the study of the
secondary cosmic ray radiation by using muon tracker telescopes made of three
Multigap Resistive Plate Chambers (MRPC) each. The experiment consists of a
telescope network mainly distributed across Italy, hosted in different building
structures pertaining to high schools, universities and research centers.
Therefore, the possibility to take into account the effects of these structures
on collected data is important for the large physics programme of the project.
A simulation tool, based on GEANT4 and using GEMC framework, has been
implemented to take into account the muon interaction with EEE telescopes and
to estimate the effects on data of the structures surrounding the experimental
apparata.A dedicated event generator producing realistic muon distributions,
detailed geometry and microscopic behavior of MRPCs have been included to
produce experimental-like data. The comparison between simulated and
experimental data, and the estimation of detector resolutions is here presented
and discussed
Design and construction of new central and forward muon counters for CDF II
New scintillation counters have been designed and constructed for the CDF
upgrade in order to complete the muon coverage of the central CDF detector, and
to extend this coverage to larger pseudorapidity. A novel light collection
technique using wavelength shifting fibers, together with high quality
polystyrene-based scintillator resulted in compact counters with good and
stable light collection efficiency over lengths extending up to 320 cm. Their
design and construction is described and results of their initial performance
are reported.Comment: 20 pages, 15 figure
The Extreme Energy Events HECR array: status and perspectives
The Extreme Energy Events Project is a synchronous sparse array of 52
tracking detectors for studying High Energy Cosmic Rays (HECR) and Cosmic
Rays-related phenomena. The observatory is also meant to address Long Distance
Correlation (LDC) phenomena: the network is deployed over a broad area covering
10 degrees in latitude and 11 in longitude. An overview of a set of preliminary
results is given, extending from the study of local muon flux dependance on
solar activity to the investigation of the upward-going component of muon flux
traversing the EEE stations; from the search for anisotropies at the sub-TeV
scale to the hints for observations of km-scale Extensive Air Shower (EAS).Comment: XXV ECRS 2016 Proceedings - eConf C16-09-04.
Identification and assessment of intimate partner violence in nurse home visitation
Aims and objectives: To develop strategies for the identification and assessment of intimate partner violence in a nurse home visitation programme. Background: Nurse home visitation programmes have been identified as an intervention for preventing child abuse and neglect. Recently, there is an increased focus on the role these programmes have in addressing intimate partner violence. Given the unique context of the home environment, strategies for assessments are required that maintain the therapeutic alliance and minimise client attrition. Design: A qualitative case study. Methods: A total of four Nurse–Family Partnership agencies were engaged in this study. Purposeful samples of nurses (n = 32), pregnant or parenting mothers who had self-disclosed experiences of abuse (n = 26) and supervisors (n = 5) participated in this study. A total of 10 focus groups were completed with nurses: 42 interviews with clients and 10 interviews with supervisors. The principles of conventional content analysis guided data analysis. Data were categorised using the practice–problem–needs analysis model for integrating qualitative findings in the development of nursing interventions. Results: Multiple opportunities to ask about intimate partner violence are valued. The use of structured screening tools at enrolment does not promote disclosure or in-depth exploration of women\u27s experiences of abuse. Women are more likely to discuss experiences of violence when nurses initiate nonstructured discussions focused on parenting, safety or healthy relationships. Nurses require knowledge and skills to initiate indicator-based assessments when exposure to abuse is suspected as well as strategies for responding to client-initiated disclosures. Conclusion: A tailored approach to intimate partner violence assessment in home visiting is required. Relevance to clinical practice: Multiple opportunities for exploring women\u27s experiences of violence are required. A clinical pathway outlining a three-pronged approach to identification and assessment was developed
Effect of Addition of an Intimate Partner Violence Intervention to a Nurse Home Visitation Program on Maternal Quality of Life: A Randomized Clinical Trial
Importance: Intimate partner violence (IPV) is a public health problem with significant adverse consequences for women and children. Past evaluations of a nurse home visitation program for pregnant women and first-time mothers experiencing social and economic disadvantage have not consistently shown reductions in IPV. Objective: To determine the effect on maternal quality of life of a nurse home visitation program augmented by an IPV intervention, compared with the nurse home visitation program alone. Design, Setting, and Participants: Cluster-based, single-blind, randomized clinical trial at 15 sites in 8 US states (May 2011-May 2015) enrolling 492 socially disadvantaged pregnant women (≥16 years) participating in a 2.5-year nurse home visitation program. Interventions: In augmented program sites (n = 229 participants across 7 sites), nurses received intensive IPV education and delivered an IPV intervention that included a clinical pathway to guide assessment and tailor care focused on safety planning, violence awareness, self-efficacy, and referral to social supports. The standard program (n = 263 participants across 8 sites) included limited questions about violence exposure and information for abused women but no standardized IPV training for nurses. Main Outcomes and Measures: The primary outcome was quality of life (WHOQOL-BREF; range, 0-400; higher score indicates better quality of life) obtained through interviews at baseline and every 6 months until 24 months after delivery. From 17 prespecified secondary outcomes, 7 secondary end points are reported, including scores on the Composite Abuse Scale, SPAN (Startle, Physiological Arousal, Anger, and Numbness), Prime-MD Patient Health Questionnaire, TWEAK (Tolerance/Worry About Drinking/Eye-Opener/Amnesia/C[K]ut Down on Drinking), Drug Abuse Severity Test, and the 12-Item Short-Form Health Survey (physical and mental health), version 2. Results: Among 492 participants enrolled (mean age, 20.4 years), 421 (86%) completed the trial. Quality of life improved from baseline to 24 months in both groups (change in WHOQOL-BREF scores from 299.5 [SD, 54.4] to 308.2 [SD, 52.6] in the augmented program group vs from 293.6 [SD, 56.4] to 316.4 [SD, 57.5] in the standard program group). Based on multilevel growth curve analysis, there was no statistically significant difference between groups (modeled score difference, -4.9 [95% CI, -16.5 to 6.7]). There were no statistically significant differences between study groups in any of the secondary participant end points. There were no adverse events recorded in either group. Conclusions and Relevance: Among pregnant women experiencing social and economic disadvantage and preparing to parent for the first time, augmentation of a nurse home visitation program with a comprehensive IPV intervention, compared with the home visitation program alone, did not significantly improve quality of life at 24 months after delivery. These findings do not support the use of this intervention. Trial Registration: ClinicalTrials.gov Identifier: NCT01372098
Proton-proton elastic scattering at the LHC energy of {\surd} = 7 TeV
Proton-proton elastic scattering has been measured by the TOTEM experiment at
the CERN Large Hadron Collider at {\surd}s = 7 TeV in dedicated runs with the
Roman Pot detectors placed as close as seven times the transverse beam size
(sbeam) from the outgoing beams. After careful study of the accelerator optics
and the detector alignment, |t|, the square of four-momentum transferred in the
elastic scattering process, has been determined with an uncertainty of d t =
0.1GeV p|t|. In this letter, first results of the differential cross section
are presented covering a |t|-range from 0.36 to 2.5GeV2. The differential
cross-section in the range 0.36 < |t| < 0.47 GeV2 is described by an
exponential with a slope parameter B = (23.6{\pm}0.5stat {\pm}0.4syst)GeV-2,
followed by a significant diffractive minimum at |t| =
(0.53{\pm}0.01stat{\pm}0.01syst)GeV2. For |t|-values larger than ~ 1.5GeV2, the
cross-section exhibits a power law behaviour with an exponent of -7.8_\pm}
0.3stat{\pm}0.1syst. When compared to predictions based on the different
available models, the data show a strong discriminative power despite the small
t-range covered.Comment: 12pages, 5 figures, CERN preprin
- …