Measurements, processing functions and laboratory test-bed experiments for evaluating diversity in broadcast network

This paper presents a test-bed development and measurement plan for evaluating transmit diversity and on-channel repeaters in the Digital Video Broadcasting Network. Transmit diversity reduces the complexity and improves the power consumption of the personal receiving devices by enhancing the transmission of signals in NLOS cluttered environments. It is more practical than receive diversity due to the difficulty of locating two receive antennas far enough apart in a small mobile device. The on-channel repeater is to extend the coverage of the DVB-T/H network in areas where services are inaccessible by receiving the DVB-T/H signals off air, amplifying and then retransmitting it on the same frequency as received. Test service scenarios were developed to illustrate the benefits of such technologies so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems.The work presented in this paper was supported by the European Commission IST project PLUTO

Laboratory measurement campaign of DVB-T signal with transmit delay diversity

The requirements for future DVB-T/H networks demand that broadcasters design and deploy networks that provide ubiquitous reception in challenging indoors and other obstructed situations. It is essential that such networks are designed cost-effectively and with minimized environmental impact. The EC funded project PLUTO has since its start in 2006 explored the use of diversity to improve coverage in these difficult situations. The purpose of this paper is to investigate the performance of Transmit Delay Diversity (DD) with two antennas to improve the reception of DVB-T/H systems operating in different realistic propagation conditions through a series of tests using a SPIRENT SR5500 dual channel emulator. The relationship between correlation coefficient between channels, receiver velocity and diversity gain is nvestigated. It is shown that transmit delay diversity significantly improves the quality of reception particularly in simulated fast fading mobile broadcasting applications. This paper documents research conducted by Brunel University and Broadreach Systems

Biomechanical analysis and modeling of different vertebral growth patterns in adolescent idiopathic scoliosis and healthy subjects

<p>Abstract</p> <p>Background</p> <p>The etiology of AIS remains unclear, thus various hypotheses concerning its pathomechanism have been proposed. To date, biomechanical modeling has not been used to thoroughly study the influence of the abnormal growth profile (i.e., the growth rate of the vertebral body during the growth period) on the pathomechanism of curve progression in AIS. This study investigated the hypothesis that AIS progression is associated with the abnormal growth profiles of the anterior column of the spine.</p> <p>Methods</p> <p>A finite element model of the spinal column including growth dynamics was utilized. The initial geometric models were constructed from the bi-planar radiographs of a normal subject. Based on this model, five other geometric models were generated to emulate different coronal and sagittal curves. The detailed modeling integrated vertebral body growth plates and growth modulation spinal biomechanics. Ten years of spinal growth was simulated using AIS and normal growth profiles. Sequential measures of spinal alignments were compared.</p> <p>Results</p> <p>(1) Given the initial lateral deformity, the AIS growth profile induced a significant Cobb angle increase, which was roughly between three to five times larger compared to measures utilizing a normal growth profile. (2) Lateral deformities were absent in the models containing no initial coronal curvature. (3) The presence of a smaller kyphosis did not produce an increase lateral deformity on its own. (4) Significant reduction of the kyphosis was found in simulation results of AIS but not when using the growth profile of normal subjects.</p> <p>Conclusion</p> <p>Results from this analysis suggest that accelerated growth profiles may encourage supplementary scoliotic progression and, thus, may pose as a progressive risk factor.</p

Simulated-Physiological Loading Conditions Preserve Biological and Mechanical Properties of Caprine Lumbar Intervertebral Discs in Ex Vivo Culture

Low-back pain (LBP) is a common medical complaint and associated with high societal costs. Degeneration of the intervertebral disc (IVD) is assumed to be an important causal factor of LBP. IVDs are continuously mechanically loaded and both positive and negative effects have been attributed to different loading conditions

Vitamin D exposure and Risk of Breast Cancer: a meta-analysis

The relationship between vitamin D and breast cancer is still controversial. The present meta-analysis examines the effects of the 25(OH)D, 1,25(OH)2D and vitamin D intake on breast cancer risk. For this purpose, a PubMed, Scopus and Web of Science-databases search was conducted including all papers published with the keywords "breast cancer" and "vitamin D" with at least one reported relative risk (RR) or odds ratio (OR). In total sixty eight studies published between 1998 and 2018 were analyzed. Information about type of study, hormonal receptors and menopausal status was retrieved. Pooled OR or RR were estimated by weighting individual OR/RR by the inverse of their variance Our study showed a protective effect between 25 (OH) D and breast cancer in both cohort studies (RR?=?0.85, 95%CI:0.74-0.98) and case-control studies (OR?=?0.65, 95%CI: 0.56-0.76). However, analyzing by menopausal status, the protective vitamin D - breast cancer association persisted only in the premenopausal group (OR?=?0.67, 95%CI: 0.49-0.92) when restricting the analysis to nested case-control studies. No significant association was found for vitamin D intake or 1,25(OH)2D. CONCLUSION: This systematic review suggests a protective relationship between circulating vitamin D (measured as 25(OH) D) and breast cancer development in premenopausal women

Induction of anti-tumor immunity by vaccination with dendritic cells pulsed with anti-CD44 IgG opsonized tumor cells

Due to the pivotal role that dendritic cells (DC) play in eliciting and maintaining functional anti-tumor T cell responses, these APC have been exploited against tumors. DC express several receptors for the Fc portion of IgG (Fcγ receptors) that mediate the internalization of antigen-IgG complexes and promote efficient MHC class I and II restricted antigen presentation. In this study, the efficacy of vaccination with DC pulsed with apoptotic B16 melanoma cells opsonized with an anti-CD44 IgG (B16-CD44) was explored. Immature bone marrow derived DC grown in vitro with IL-4 and GM-CSF were pulsed with B16-CD44. After 48 h of pulsing, maturation of DC was demonstrated by production of IL-12 and upregulation of CD80 and CD40 expression. To test the efficacy of vaccination with DC+B16-CD44, mice were vaccinated subcutaneously Lymphocytes from mice vaccinated with DC+B16-CD44 produced IFN-γ in response to B16 melanoma lysates as well as an MHC class I restricted B16 melanoma-associated peptide, indicating B16 specific CD8 T cell activation. Upon challenge with viable B16 cells, all mice vaccinated with DC alone developed tumor compared to 40% of mice vaccinated with DC+B16-CD44; 60% of the latter mice remained tumor free for at least 8 months. In addition, established lung tumors and distant metastases were significantly reduced in mice treated with DC+B16-CD44. Lastly, delayed growth of established subcutaneous tumors was induced by combination therapy with anti-CD44 antibodies followed by DC injection. This study demonstrates the efficacy of targeting tumor antigens to DC via Fcγ receptors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45862/1/262_2005_Article_104.pd

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Search for dark matter produced in association with a single top quark or a top quark pair in proton-proton collisions at s=13 TeV

A search has been performed for heavy resonances decaying to ZZ or ZW in 2l2q final states, with two charged leptons (l = e, mu) produced by the decay of a Z boson, and two quarks produced by the decay of a W or Z boson. The analysis is sensitive to resonances with masses in the range from 400 to 4500 GeV. Two categories are defined based on the merged or resolved reconstruction of the hadronically decaying vector boson, optimized for high- and low-mass resonances, respectively. The search is based on data collected during 2016 by the CMS experiment at the LHC in proton-proton collisions with a center-of-mass energy of root s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). No excess is observed in the data above the standard model background expectation. Upper limits on the production cross section of heavy, narrow spin-1 and spin-2 resonances are derived as a function of the resonance mass, and exclusion limits on the production of W' bosons and bulk graviton particles are calculated in the framework of the heavy vector triplet model and warped extra dimensions, respectively.A search has been performed for heavy resonances decaying to ZZ or ZW in 2l2q final states, with two charged leptons (l = e, mu) produced by the decay of a Z boson, and two quarks produced by the decay of a W or Z boson. The analysis is sensitive to resonances with masses in the range from 400 to 4500 GeV. Two categories are defined based on the merged or resolved reconstruction of the hadronically decaying vector boson, optimized for high- and low-mass resonances, respectively. The search is based on data collected during 2016 by the CMS experiment at the LHC in proton-proton collisions with a center-of-mass energy of root s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). No excess is observed in the data above the standard model background expectation. Upper limits on the production cross section of heavy, narrow spin-1 and spin-2 resonances are derived as a function of the resonance mass, and exclusion limits on the production of W' bosons and bulk graviton particles are calculated in the framework of the heavy vector triplet model and warped extra dimensions, respectively.A search for dark matter produced in association with top quarks in proton-proton collisions at a center-of-mass energy of 13 TeV is presented. The data set used corresponds to an integrated luminosity of 35.9 fb(-1) recorded with the CMS detector at the LHC. Whereas previous searches for neutral scalar or pseudoscalar mediators considered dark matter production in association with a top quark pair only, this analysis also includes production modes with a single top quark. The results are derived from the combination of multiple selection categories that are defined to target either the single top quark or the top quark pair signature. No significant deviations with respect to the standard model predictions are observed. The results are interpreted in the context of a simplified model in which a scalar or pseudoscalar mediator particle couples to a top quark and subsequently decays into dark matter particles. Scalar and pseudoscalar mediator particles with masses below 290 and 300 GeV, respectively, are excluded at 95% confidence level, assuming a dark matter particle mass of 1 GeV and mediator couplings to fermions and dark matter particles equal to unity.Peer reviewe