87 research outputs found
Rays of light from the LHC
We consider models for the di-photon resonance observed at ATLAS (with 3.6
fb^{-1}) and CMS (with 2.6 fb^{-1}). We find there is no conflict between the
signal reported at 13 TeV, and the constraints from both experiments at 8 TeV
with 20.3 fb^{-1}. We make a simple argument for why adding only one new
resonance to the standard model (SM) is not sufficient to explain the
observation. We explore four viable options: (i): resonance production and
decay through loops of messenger fermions or scalars; (ii): a resonant
messenger which decays to the di-photon resonance + X; (iii): an edge
configuration where A -> B gamma -> C gamma gamma, and (iv): Hidden Valley-like
models where the resonance decays to a pair of very light (sub-GeV) states,
each of which in turn decays to a pair of collimated photons that cannot be
distinguished from a single photon. Since in each case multiple new states have
been introduced, a wealth of signatures is expected to ensue at Run-2 of LHC.Comment: 20 pages, 9 figures. Typos corrected, appendix A updated and
references adde
Evaluating the burden of amblyopia treatment from the parent and child’s perspective
To evaluate the psychometric properties of the original Parent and new Child Amblyopia Treatment Index (ATI), questionnaires that assess the burden of amblyopia treatment in children and families, and to compare scores between children treated with atropine or patching
Lutein supplementation in retinitis pigmentosa: PC-based vision assessment in a randomized double-masked placebo-controlled clinical trial [NCT00029289]
BACKGROUND: There is no generally accepted medical or surgical treatment to stop the progressive course of retinitis pigmentosa. Previous studies have suggested lutein as a potential treatment with positive effects on macular pigment density. The objective of this study was to examine the effect of lutein supplementation on preservation of visual function in patients with retinitis pigmentosa (RP) METHODS: In a double-masked randomized placebo-controlled phase I/II clinical trial with a cross-over design, 34 adult patients with RP were randomized to two groups. One group, consisted of 16 participants, received lutein supplementation (10 mg/d for 12 wks followed by 30 mg/d) for the first 24 weeks and then placebo for the following 24 weeks, while the other group included 18 participants for whom placebo (24 weeks) was administered prior to lutein. Visual acuity, contrast sensitivity, and central visual field were measured at different illumination levels at baseline and every week using a PC-based test at home. RESULTS: For visual acuity (VA) at normal illumination level, treatment with lutein reduced logMAR, i.e. improved VA, but this effect was not statistically significant. The changes in normal (100%), low (4%), and very low (0.1%) illumination log CS were not statistically significant (p-values: 0.34, 0.23, and 0.32, respectively). Lutein had a statistically significant effect on visual field (p-value: 0.038) and this effect increased in the model assuming a 6-week delay in effect of lutein. Comparing the development of vision measures against the natural loss expected to occur over the course of 48 weeks, most measures showed reduced decline, and these reductions were significant for normal illumination VA and CS. CONCLUSION: These results suggest that lutein supplementation improves visual field and also might improve visual acuity slightly, although these results should be interpreted cautiously. As a combined phase I and II clinical trial, this study demonstrated the efficacy and safety of lutein supplementation
When mobile networks meet content delivery networks
In this paper we design a novel mobile network architecture where we merge the advantages of using Distributed Mobility Management (DMM) functionalities with the flexibility brought by implementing mobile Content Delivery Networks (CDN). DMM is seen as one of the key technologies allowing distribution of mobility functions (i.e., mobility anchors) up to now centralized at single and expensive points. CDN is a crucial design choice for Network Operators, which enables large scale content distribution at a reasonable cost and without overloading the operator's core network. As a result of the combination of these two concepts, this paper discusses system and architectural aspects, and provides insights into the design of mobile networks as a global delivery platform and not as a stand alone mobility service. New business opportunities derived from this novel delivery architecture are discussed, as well considerations for practical deployment in next generation cellular networks
Online path selection for video delivery over cellular networks2012 IEEE Globecom Workshops
none4The increasing amount of online video content offered by network operators to mobile users opens the door to new challenging optimizations. In a mobile network video applications can be served through several video delivery paths, resulting in different video quality experienced by the end user. The mobile operator is in charge of guiding the video services to keep a target video quality and to optimize the network resource usage, taking into account network metrics related to both core and wireless access networks. We design a framework which runs online algorithms to select the best path for video delivery based on a set of performance metrics evaluated for a range of settings by means of simulation.noneDaniele Munaretto;Telemaco Melia;Sabine Randriamasy;Michele ZorziMunaretto, Daniele; Telemaco, Melia; Sabine, Randriamasy; Zorzi, Michel
Evaluation of the Intermittent Exotropia Questionnaire Using Rasch Analysis
IMPORTANCE: The Intermittent Exotropia Questionnaire (IXTQ) is a patient, proxy, and parental report of quality of life specific to children with intermittent exotropia. We refine the IXTQ using Rasch analysis to improve reliability and validity. OBSERVATION: Rasch analysis was performed on responses of 575 patients with intermittent exotropia enrolled from May 15, 2008, through July 24, 2013, and their parents from each of the 4 IXTQ health-related quality-of-life questionnaires (child 5 through 7 years of age and child 8 through 17 years of age, proxy, and parent questionnaires). Questionnaire performance and structure were confirmed in a separate cohort of 379 patients with intermittent exotropia. One item was removed from the 12-item child and proxy questionnaires, and response options in the 8- to 17-year-old child IXTQ and proxy IXTQ were combined into 3 response options for both questionnaires. Targeting was relatively poor for the child and proxy questionnaires. For the parent questionnaire, 3 subscales (psychosocial, function, and surgery) were evident. One item was removed from the psychosocial subscale. Resulting subscales had appropriate targeting. CONCLUSIONS AND RELEVANCE: The Rasch-revised IXTQ may be a useful instrument for determining how intermittent exotropia affects health-related quality of life of children with intermittent exotropia and their parents, particularly for cohort studies
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