Design methodology and performance analysis of a wideband 90º phase switch for radiometer applications

This paper presents the analysis, design, and characterization of a wideband 90º phase switch in Ka-band. The phase switch is based on two microstrip bandpass filters in which the commutation is performed by a novel single-pole double-throw (SPDT) switch. The analysis of π-network bandpass filters is provided, obtaining the phase difference and amplitude imbalance between filters and their scattering parameters; tested results show an average phase difference of 88.9º ± 5º and an amplitude imbalance of 0.15 dB from 24 to 37 GHz. The new broadband SPDT switch is based on a coplanar waveguide-to-slotline-to-microstrip structure, which enables a full planar integration with shifting branches. PIN diodes are used to perform the switching between outputs. The SPDT shows isolation better than 19 dB, insertion loss of around 1.8 dB, and return loss better than 15 dB. The full integration of the phase switch achieves a return loss better than 11 dB and insertion loss of around 4 dB over the band 26–36 GHz, with an average phase difference of 87.1º ± 4º and an average amplitude imbalance of 0.3 dB. It provides an excellent performance for this frequency range, suitable for radio-astronomy receivers.The authors would like to thank the Spanish Ministry for Science and Innovation for the financial support provided under the Project No. AYA2010–21766-C03–03 and the CONSOLIDER-INGENIO 2010 programme under Reference No. CSD2010–00064

Accuracy of p53 codon 72 polymorphism status determined by multiple laboratory methods: a latent class model analysis

INTRODUCTION: Studies on the association of a polymorphism in codon 72 of the p53 tumour suppressor gene (rs1042522) with cervical neoplasia have inconsistent results. While several methods for genotyping p53 exist, they vary in accuracy and are often discrepant. METHODS: We used latent class models (LCM) to examine the accuracy of six methods for p53 determination, all conducted by the same laboratory. We also examined the association of p53 with cytological cervical abnormalities, recognising potential test inaccuracy. RESULTS: Pairwise disagreement between laboratory methods occurred approximately 10% of the time. Given the estimated true p53 status of each woman, we found that each laboratory method is most likely to classify a woman to her correct status. Arg/Arg women had the highest risk of squamous intraepithelial lesions (SIL). Test accuracy was independent of cytology. There was no strong evidence for correlations of test errors. DISCUSSION: Empirical analyses ignore possible laboratory errors, and so are inherently biased, but test accuracy estimated by the LCM approach is unbiased when model assumptions are met. LCM analysis avoids ambiguities arising from empirical test discrepancies, obviating the need to regard any of the methods as a “gold” standard measurement. The methods we presented here to analyse the p53 data can be applied in many other situations where multiple tests exist, but where none of them is a gold standard

Polarimetric receiver in the forty gigahertz band: new instrument for the Q-U-I joint Tenerife experiment

This paper describes the analysis, design and characterization of a polarimetric receiver developed for covering the 35 to 47 GHz frequency band in the new instrument aimed at completing the ground-based Q-U-I Joint Tenerife Experiment. This experiment is designed to measure polarization in the Cosmic Microwave Background. The described high frequency instrument is a HEMT-based array composed of 29 pixels. A thorough analysis of the behaviour of the proposed receiver, based on electronic phase switching, is presented for a noise-like linearly polarized input signal, obtaining simultaneously I, Q and U Stokes parameters of the input signal. Wideband subsystems are designed, assembled and characterized for the polarimeter. Their performances are described showing appropriate results within the 35-to-47 GHz frequency band. Functionality tests are performed at room and cryogenic temperatures with adequate results for both temperature conditions, which validate the receiver concept and performance.The authors would like to thank the Spanish Ministry of Economy, Industry and Competitiveness for the financial support provided through the CONSOLIDER-INGENIO 2010 program under the grant CSD2010-00064 and under the grant ESP2015-70646-C2-2-R

“THOSE WHO LOVE, VACCINATE”: PARENTAL PERCEPTIONS OF HPV VACCINATION

Introduction: In March 2014, Brazil began its national HPV immunization campaign targeting girls ages 9-13. Objective: Describe determinants of parental decisions to vaccinate their daughters against HPV.Method: In this qualitative study, thirty semi-structured interviews were conducted at five health posts in São Paulo, Brazil. Interview questions explored parental opinions of disease prevention methods, vaccines in general, and the HPV vaccine. Interviews were analyzed using grounded theory. Results: Overall, parental knowledge about HPV and the vaccine was low, yet most eligible daughters had been vaccinated. Parents perceived the HPV vaccine to be normal, preventative, and protective. Parents viewed themselves as accountable for their children’s health, and saw the vaccine as a parenting tool for indirect control. Trust in healthcare professionals and an awareness of the dangers of “nowadays” (uncertainties regarding disease and sexual behavior) were also important in vaccine decision-making. These factors held more explanatory power for decisions to vaccinate than parental knowledge levels. This was the first study to qualitatively examine the perception of publically provided HPV vaccination among parents with eligible daughters in Brazil. The findings help interpret the greater than 90% coverage for the first HPV vaccine dose in Brazil. The results indicate that attempts to understand, maintain, or modify vaccination rates require the consideration of context specific factors, which influence both parent perspectives and vaccination decisions. Conclusion: HPV knowledge levels are not predictive of parental decisions to vaccinate daughters. Context specific factors from the sociocultural dimensions of parenting, sexuality, gender, and the healthcare system are more influential in vaccine decision-making

Male circumcision and the incidence and clearance of genital human papillomavirus (HPV) infection in men: the HPV Infection in men (HIM) cohort study

Background: Reported associations of male circumcision (MC) with human papillomavirus (HPV) infection in men have been inconsistent. Methods: 4,033 healthy men were examined every six months for a median of 17.5 months. In each study visit, exfoliated cell specimens from the coronal sulcus/glans penis, penile shaft, and scrotum were collected and combined into one sample per person for HPV DNA detection. Samples were tested for 37 HPV types. Cox proportional hazards models were used to evaluate the association between MC and the incidence and clearance of HPV infections and specific genotypes. Results: The overall incidence of new HPV infections did not differ by MC status (for any HPV, adjusted hazard ratio (aHR) 1.08, 95% confidence interval (CI) 0.91-1.27). However, incidence was significantly lower among circumcised versus uncircumcised men for HPV types 58 (p = 0.01), 68 (p < 0.001), 42 (p = 0.01), 61 (p < 0.001), 71 (p < 0.001), 81 (p = 0.04), and IS39 (p = 0.01), and higher for HPV types 39 (p = 0.01) and 51 (p = 0.02). Despite the lack of an overall association in the risk of HPV clearance by MC (for any HPV, aHR 0.95, 95% CI 0.88-1.02), median times to clearance were significantly shorter among circumcised than uncircumcised men for HPV types 33 (p = 0.02) and 64 (p = 0.04), and longer for HPV types 6 (p < 0.001), 16 (p < 0.001), and 51 (p = 0.02). Conclusions: MC is not associated with the incidence and clearance of genital HPV detection, except for certain HPV types. The use of a single combined sample from the penis and scrotum for HPV DNA detection likely limited our ability to identify a true effect of MC at the distal penis

HPV type infection in different anogenital sites among HIV-positive Brazilian women

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Prevalence of human papillomavirus in archival samples obtained from patients with cervical pre-malignant and malignant lesions from Northeast Brazil

<p>Abstract</p> <p>Background</p> <p>Human Papillomavirus (HPV) is considered as a necessary, but not sufficient, cause of cervical cancer. In this study, we aimed to assess the prevalence of HPV in a series of pre-malignant and malignant cervical lesion cases, to identify the virus genotypes, and to assess their distribution pattern according to lesion type, age range, and other considered variables. The samples were submitted to histopathological revision examination and analysed by polymerase chain reaction (PCR) for the presence of HPV DNA, followed by HPV typing by dot blot hybridisation.</p> <p>Findings</p> <p>Of the analysed samples, 53.7% showed pre-malignant cervical lesions, and 46.3% presented with cervical cancer. Most cancer samples (84.1%) were classified as invasive carcinoma. The mean age of these cancer patients was 47.3 years. The overall HPV prevalence was 82.4% in patients with pre-malignant lesions and 92.0% in the cancer patients. HPV 16 was the most prevalent type, followed by HPV 18 and 58, including both single and double infections. Double infection was detected in 11.6% of the samples, and the most common combination was HPV 16+18.</p> <p>Conclusions</p> <p>Cervical cancer appears to occur in women in a lower age range in the studied area, compared to the situation in other Brazilian regions. Furthermore, among the patients with CIN 3 and those with cancer, we observed a higher proportion of married women, women with more than one sexual partner, smokers, and individuals with less than an elementary education, relative to their counterparts.</p> <p>Findings</p> <p>The overall HPV prevalence was 82.4% in patients with pre-malignant lesions and 92.0% in the cervical cancer patients from Northeast Brazil. HPV 16 was the most prevalent type, followed by HPV 18 and 58. The most common double infection was HPV 16+18. Cervical cancer appears to occur in women in a lower age range in the Northeast Brazil. Among the patients with CIN 3 and those with cancer, we observed a higher proportion of married women, women with more than one sexual partner, smokers, and individuals with less than an elementary education, relative to their counterparts.</p

Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP

Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~ events. Spin correlations are favoured by data, and found to agree with the Standard Model predictions. In addition, correlations between the W-boson decay planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events. Decay-plane correlations, consistent with zero and with the Standard Model predictions, are measured

Ultrarelativistic sources in nonlinear electrodynamics

The fields of rapidly moving sources are studied within nonlinear electrodynamics by boosting the fields of sources at rest. As a consequence of the ultrarelativistic limit the delta-like electromagnetic shock waves are found. The character of the field within the shock depends on the theory of nonlinear electrodynamics considered. In particular, we obtain the field of an ultrarelativistic charge in the Born-Infeld theory.Comment: 10 pages, 3 figure