On radio interference filter measurement

A new measurement method for on site testing of multiport radio interference filters (RIF) on shielded chamber is designed. The method is based on scalar measurement only and makes possible a pessimistic estimate of the filters damping in frequency band from DC-3 GHz. More than 120 dB dynamic of measurement can be expected. At the time being there is no acceptable standard for these multiport measurements

Noise Figure Measurement of Highly Mismatched DUT

A device mismatch seriously degrades the accuracy of its noise figure characterization. A new second stage correction technique for highly mismatched device under test is proposed and compared to the standard technique. The presented method is based on additional vector measurement. It takes into account measuring receiver noise figure dependence on the DUT output mismatch besides an available gain correction. Significant accuracy improvement of measured data and decreased error variation is demonstrated. The suggested method is in principle able to eliminate all systematic errors in noise figure measurement

A New Concept of PTP Vector Network Analyzer

A new concept for vector network analyzers design based on a perturbation two-port (PTP) is presented. The approach uses redundant states of the PTP. The best states of the PTP for a certain place in Smith chart and frequency are chosen to determine a reflection coefficient with minimum uncertainty. Four criteria for the selection are designed. The criteria were tested on measured parameters of different states of the PTP. Significant improvements in PTP bandwidth and uncertainty of measured data were achieved

Association Between Hearing and Vision Impairment and Risk of Dementia: Results of a Case-Control Study Based on Secondary Data

Introduction: Hearing and vision loss are highly prevalent in elderly adults, and thus frequently occur in conjunction with cognitive impairments. Studies have shown that hearing impairment is associated with a higher risk of dementia. However, evidence concerning the association between vision loss and dementia, as well as the co-occurrence of vision and hearing loss and dementia, has been inconclusive. Objectives: To assess the association between: (i) either hearing or vision loss and the risk of dementia, as well as between; and (ii) the combination of both sensory impairments and the risk of dementia. Methods: This case-control study was based on a 5-year data set that included patients aged 65 years and older who had initially been diagnosed with dementia diseases by one of 1,203 general practitioners in Germany between January 2013 and December 2017. In total, 61,354 identified dementia cases were matched to non-dementia controls, resulting in a sample size of 122,708 individuals. Hearing loss and vision loss were identified using the ICD-10 diagnoses documented in the general practitioners’ files prior to the initial dementia diagnosis. Multivariate logistic regression models were fitted to evaluate the associations between visual and/or hearing impairment and the risk of dementia and controlled for sociodemographic and clinical variables. Results: Hearing impairment was documented in 11.2% of patients with a dementia diagnosis and 9.5% of patients without such a diagnosis. Some form of vision impairment was documented in 28.4% of patients diagnosed with dementia and 28.8% of controls. Visual impairment was not significantly associated with dementia (OR = 0.97, CI = 95% 0.97–1.02, p = 0.219). However, patients with hearing impairment were at a significantly higher risk of developing dementia (OR = 1.26, CI = 95% 1.15–1.38, p < 0.001), a finding that very likely led to the observed significant association of the combination of both visual and hearing impairments and the risk of dementia (OR = 1.14, CI = 95% 1.04–1.24, p = 0.005). Discussion: This analysis adds important evidence that contributes to the limited body of knowledge about the association between hearing and/or vision loss and dementia. It further demonstrates that, of the two, only hearing impairment affects patients’ cognition and thus contributes to dementia risk

Myocardial Ischemia and Reperfusion Leads to Transient CD8 Immune Deficiency and Accelerated Immunosenescence in CMV-Seropositive Patients

Rationale: There is mounting evidence of a higher incidence of coronary heart disease (CHD) in cytomegalovirus (CMV) seropositive individuals. Objective: The aim of this study was to investigate whether acute MI triggers an inflammatory T-cell response that might lead to accelerated immunosenescence in CMV-seropositive patients. Methods and Results: Thirty-four patients with acute MI undergoing primary PCI (PPCI) were longitudinally studied within 3 months following reperfusion (Cohort A). In addition, 54 patients with acute and chronic MI were analyzed in a cross-sectional study (Cohort B). CMV-seropositive patients demonstrated a greater fall in the concentration of terminally differentiated CD8 effector memory T cells (TEMRA) in peripheral blood during the first 30 min of reperfusion compared with CMV-seronegative patients (-192 vs. -63 cells/µl; p=0.008), correlating with the expression of programmed cell death-1 (PD-1) before PPCI (r=0.8; p=0.0002). A significant proportion of TEMRA cells remained depleted for at least 3 months in CMV-seropositive patients. Using high-throughput 13-parameter flow cytometry and HLA class I CMV-specific dextramers, we confirmed an acute and persistent depletion of terminally differentiated TEMRA and CMV-specific CD8+ cells in CMV-seropositive patients. Long-term reconstitution of the TEMRA pool in chronic CMV-seropositive post-MI patients was associated with signs of terminal differentiation including an increase in KLRG1 and shorter telomere length in CD8+ T cells (2225 bp vs. 3397 bp; p<0.001). Conclusions: Myocardial ischemia and reperfusion in CMV-seropositive patients undergoing PPCI leads to acute loss of antigen-specific, terminally differentiated CD8 T-cells, possibly through PD-1-dependent programmed cell death. Our results suggest that acute MI and reperfusion accelerate immunosenescence in CMV-seropositive patients

Role of Position 627 of PB2 and the Multibasic Cleavage Site of the Hemagglutinin in the Virulence of H5N1 Avian Influenza Virus in Chickens and Ducks

Highly pathogenic H5N1 avian influenza viruses have caused major disease outbreaks in domestic and free-living birds with transmission to humans resulting in 59% mortality amongst 564 cases. The mutation of the amino acid at position 627 of the viral polymerase basic-2 protein (PB2) from glutamic acid (E) in avian isolates to lysine (K) in human isolates is frequently found, but it is not known if this change affects the fitness and pathogenicity of the virus in birds. We show here that horizontal transmission of A/Vietnam/1203/2004 H5N1 (VN/1203) virus in chickens and ducks was not affected by the change of K to E at PB2-627. All chickens died between 21 to 48 hours post infection (pi), while 70% of the ducks survived infection. Virus replication was detected in chickens within 12 hours pi and reached peak titers in spleen, lung and brain between 18 to 24 hours for both viruses. Viral antigen in chickens was predominantly in the endothelium, while in ducks it was present in multiple cell types, including neurons, myocardium, skeletal muscle and connective tissues. Virus replicated to a high titer in chicken thrombocytes and caused upregulation of TLR3 and several cell adhesion molecules, which may explain the rapid virus dissemination and location of viral antigen in endothelium. Virus replication in ducks reached peak values between 2 and 4 days pi in spleen, lung and brain tissues and in contrast to infection in chickens, thrombocytes were not involved. In addition, infection of chickens with low pathogenic VN/1203 caused neuropathology, with E at position PB2-627 causing significantly higher infection rates than K, indicating that it enhances virulence in chickens

Unbinned Deep Learning Jet Substructure Measurement in High Q2Q^2 ep collisions at HERA

The radiation pattern within high energy quark- and gluon-initiated jets (jet substructure) is used extensively as a precision probe of the strong force as well as an environment for optimizing event generators with numerous applications in high energy particle and nuclear physics. Looking at electron-proton collisions is of particular interest as many of the complications present at hadron colliders are absent. A detailed study of modern jet substructure observables, jet angularities, in electron-proton collisions is presented using data recorded using the H1 detector at HERA. The measurement is unbinned and multi-dimensional, using machine learning to correct for detector effects. All of the available reconstructed object information of the respective jets is interpreted by a graph neural network, achieving superior precision on a selected set of jet angularities. Training these networks was enabled by the use of a large number of GPUs in the Perlmutter supercomputer at Berkeley Lab. The particle jets are reconstructed in the laboratory frame, using the $k_{\mathrm{T}}$ jet clustering algorithm. Results are reported at high transverse momentum transfer $Q^2>150$ GeV${}^2$, and inelasticity $0.2 < y < 0.7$. The analysis is also performed in sub-regions of $Q^2$, thus probing scale dependencies of the substructure variables. The data are compared with a variety of predictions and point towards possible improvements of such models.Comment: 33 pages, 10 figures, 8 table

Acute mountain sickness.

Acute mountain sickness (AMS) is a clinical syndrome occurring in otherwise healthy normal individuals who ascend rapidly to high altitude. Symptoms develop over a period ofa few hours or days. The usual symptoms include headache, anorexia, nausea, vomiting, lethargy, unsteadiness of gait, undue dyspnoea on moderate exertion and interrupted sleep. AMS is unrelated to physical fitness, sex or age except that young children over two years of age are unduly susceptible. One of the striking features ofAMS is the wide variation in individual susceptibility which is to some extent consistent. Some subjects never experience symptoms at any altitude while others have repeated attacks on ascending to quite modest altitudes. Rapid ascent to altitudes of 2500 to 3000m will produce symptoms in some subjects while after ascent over 23 days to 5000m most subjects will be affected, some to a marked degree. In general, the more rapid the ascent, the higher the altitude reached and the greater the physical exertion involved, the more severe AMS will be. Ifthe subjects stay at the altitude reached there is a tendency for acclimatization to occur and symptoms to remit over 1-7 days

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements