Simple Technique for source reflection coefficient measurement while characterizing active devices

This paper describes a simple, yet rigorous technique for fast and accurate determination of the source reflection coefficient during the characterization of microwave active devices. The solution consists in measuring the waves at the DUT reference plane under two different bias conditions. Since the DUT small signal impedance value depends on the bias voltage, the waves at the DUT input port changes as well. We proved that their measurements give enough information to compute the source reflection coefficient with accuracy suitable for most applications. The correction for systematic errors is based in the traditional error-box model and it does not require any exotic calibration procedures. Experimental results are presented and compared to data obtained with more traditional technique

Novel software techniques for automatic microwave measurements

Although many microwave measurement techniques are heavily based on special purpose software, the application of modern software techniques like object oriented programming and new programming language like C++ is seldom used. The impact of such new software solutions can drastically improve the overall design of a microwave test set. The paper presents the design and implementation of a new multiport network analyzer with particular attention to the control program architecture. The use of Object Oriented Programming techniques results in a clear and easy to maintain solution which boosts both the user interface and the overall test set organizatio

Load pull techniques for millimetre-wave device characterization

Load-pull experimental characterisation of active devices under non linear operation is a well proved technique still used in designing power amplifiers. When applied to the MMIC, this technique shall require special solutions to be extended to on-wafer devices up to millimetre waves. The paper presents an overview on the traditional load pull measurement techniques focusing the attention on millimetre wave application. An example of a fully automatic on-wafer system is described along with the more useful calibration techniques. By means of this test set a very detailed characterisation of devices can be carried out in short time, by setting the loads either at the fundamental or at the harmonic frequencies with independent controls

Allelic Variants of HLA-C Upstream Region, PSORS1C3, MICA, TNFA and Genes Involved in Epidermal Homeostasis and Barrier Function Influence the Clinical Response to Anti-IL-12/IL-23 Treatment of Patients with Psoriasis

Several biologic therapies have been developed to treat moderate-to-severe psoriasis, with patients exhibiting different clinical benefits, possibly due to the heterogeneity of pathogenic processes underlying their conditions. Ustekinumab targets the IL-12/IL-23-p40 subunit and inhibits type-1 and type-17 T-cell responses. Although ustekinumab is effective as both short- and long-term treatment, therapeutic response varies considerably among patients. Ustekinumab biosimilars will be commercialized in the very next future, likely broadening the use of this drug in the treatment of psoriasis patients. Our pharmacogenomic study evaluated the influence of 417 single-nucleotide polymorphisms (SNPs) in psoriasis-risk alleles on the clinical response to ustekinumab in a cohort of 152 patients affected by moderate-to-severe plaque-type psoriasis. Differences in SNP pattern characterizing HLA-Cw6(+) or HLA-Cw6(-) patients, showing high or low responses to ustekinumab, were also analysed. We identified twelve SNPs in HLA-C upstream region (rs12189871, rs4406273, rs9348862 and rs9368670), PSORS1C3 (rs1265181), MICA (rs2523497), LCE3A-B intergenic region (rs12030223, rs6701730), CDSN (rs1042127, rs4713436), CCHCR1 (rs2073719) and in TNFA (rs1800610) genes associated with excellent response to ustekinumab. We also found that HLA-Cw6(+) and HLA-Cw6(-) patients carried out distinct patterns of SNPs associated with different clinical responses. The assessment of HLA-C alleles, together with other genetic variants, could be helpful for defining patients who better benefit from anti-IL-12/IL-23 therapy

High prevalence of anti-hepatitis e virus antibodies among blood donors in central Italy, february to march 2014

Prevalence of anti-hepatitis E virus (HEV) antibodies is highly variable in developed countries, which seems partly due to differences in assay sensitivity. Using validated sensitive assays, we tested 313 blood donors attending a hospital transfusion unit in central Italy in January and February 2014 for anti-HEV IgG and IgM and HEV RNA. Data on HEV exposure were collected from all donors. Overall anti-HEV IgG prevalence was 49% (153/313). Eating raw dried pig-liver sausage was the only independent predictor of HEV infection (adjusted prevalence rate ratio = 2.14; 95% confidence interval: 1.23–3.74). Three donors were positive for either anti-HEV IgM (n = 2; 0.6%) or HEV RNA (n = 2; 0.6%); they were completely asymptomatic, without alanine aminotransferase (ALT) abnormalities. Of the two HEV RNA-positive donors (both harbouring genotype 3), one was anti-HEV IgG- and IgM-positive, the other was anti-HEV IgG- and IgM-negative. The third donor was positive for anti-HEV IgG and IgM but HEV RNA-negative. HEV infection is therefore hyperendemic among blood donors (80% men 18–64 years-old) from central Italy and associated with local dietary habits. Nearly 1% of donors have acute or recent infection, implying potential transmission to blood recipients. Neither ALT nor anti-HEV IgM testing seems useful to prevent transfusion-transmitted HEV infection. © 2016, European Centre for Disease Prevention and Control

One year of CNR-IMAA multi-wavelength Raman lidar measurements in coincidence with CALIPSO overpasses: Level 1 products comparison

At CNR-IMAA, an aerosol lidar system has operated since May 2000 in the framework of EARLINET (European Aerosol Research Lidar Network), the first lidar network for tropospheric aerosol study on a continental scale. High quality multi-wavelength measurements make this system a reference point for the validation of data products provided by CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations), the first satellite-borne lidar specifically designed for aerosol and cloud study. Since 14 June 2006, dedicated measurements have been performed at CNR-IMAA in coincidence with CALIPSO overpasses. For the first time, results on 1-year comparisons between ground-based multi-wavelength Raman lidar measurements and corresponding CALIPSO lidar Level 1 profiles are presented. A methodology for the comparison is presented and discussed in detail. Night-time cases are considered to take advantage from Raman capability of the ground based lidar. Cases with the detection of cirrus clouds in CALIPSO data are separately analysed for taking into account multiple scattering effects. For cirrus cloud cases, few cases are available to draw any conclusions. For clear sky conditions, the comparison shows good performances of the CALIPSO on-board lidar: the mean relative difference between the ground-based and CALIPSO Level 1 measurements is always within its standard deviation at all altitudes, with a mean difference in the 3–8 km altitude range of (−2±12)%. At altitude ranges corresponding to the typical PBL height observed at CNR-IMAA, a mean difference of (−24±20)% is observed in CALIPSO data, probably due to the difference in the aerosol content at the location of PEARL and CALIPSO ground-track location. Finally, the mean differences are on average lower at all altitude ranges for the closest overpasses (at about 40 km) respect to the 80-km overpasses

CIAO: the CNR-IMAA advanced observatory for atmospheric research

Long-term observations of aerosol and clouds are of crucial importance to understand the weather climate system. At the Istituto di Metodologie per l'Analisi Ambientale of the Italian National Research Council (CNR-IMAA) an advanced atmospheric observatory, named CIAO, is operative. CIAO (CNR-IMAA Atmospheric Observatory) main scientific objective is the long term measurement for the climatology of aerosol and cloud properties. Its equipment addresses the state-of-the-art for the ground-based remote sensing of aerosol, water vapour and clouds including active and passive sensors, like lidars, ceilometers, radiometers, and a radar. This paper describes the CIAO infrastructure, its scientific activities as well as the observation strategy. The observation strategy is mainly organized in order to provide quality assured measurements for satellite validation and model evaluation and to fully exploit the synergy and integration of the active and passive sensors for the improvement of atmospheric profiling. Data quality is ensured both by the application of protocols and dedicated quality assurance programs mainly related to the projects and networks in which the infrastructure is involved. The paper also introduces examples of observations performed at CIAO and of the synergies and integration algorithms (using Raman lidar and microwave profiler data) developed and implemented at the observatory for the optimization and improvement of water vapour profiling. CIAO database represents an optimal basis to study the synergy between different sensors and to investigate aerosol-clouds interactions, and can give a significant contribution to the validation programs of the incoming new generation satellite missions

Arithmetically Cohen-Macaulay Bundles on complete intersection varieties of sufficiently high multidegree

Recently it has been proved that any arithmetically Cohen-Macaulay (ACM) bundle of rank two on a general, smooth hypersurface of degree at least three and dimension at least four is a sum of line bundles. When the dimension of the hypersurface is three, a similar result is true provided the degree of the hypersurface is at least six. We extend these results to complete intersection subvarieties by proving that any ACM bundle of rank two on a general, smooth complete intersection subvariety of sufficiently high multi-degree and dimension at least four splits. We also obtain partial results in the case of threefolds.Comment: 15 page