UWB processing applied to multifrequency radar sounders. The case of MARSIS and comparison with SHARAD

We readapt ultrawideband (UWB) processing to enhance the range resolution of the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) up to a factor of 6 (25 m). The technique provides for the estimation of radar signature over a wider spectrum via the application of wellknown super-resolution (SR) techniques to adjoining subbands. The measured spectra are first interpolated and then extrapolated outside the original bands. The revised algorithm includes the estimation and removal of ionospheric effects impacting the two signals. Because the processing requires the realignment of the echoes at different frequencies, we derived the maximum tolerable retracking error to obtain reliable super-resolved range profiles. This condition is fulfilled by low-roughness areas compared to MARSIS wavelength, which proves to be suitable for the application of our processing. Examples of super-resolved experimental products over different geological scenarios show the detection of shallow dielectric interfaces not visible from original MARSIS products. Our results are validated by comparison with the Shallow Radar (SHARAD) data acquired at the crossovers, demonstrating the potential of the method to provide enhanced imaging capabilities

Levels of circulating myeloid subpopulations and of heme oxygenase-1 do not predict CD4+ T cell recovery after the initiation of antiretroviral therapy for HIV disease

The level (or frequency) of circulating monocyte subpopulations such as classical (CD14(hi)CD16(-)) and non-classical (CD14(dim)CD16(+)) monocytes varies during the course of HIV disease progression and antiretroviral therapy (ART). We hypothesized that such variation and/or differences in the degree to which these cells expressed the immunoregulatory enzyme, heme oxygenase-1 (HO-1), would be associated with CD4(+) T cell recovery after the initiation of ART. This hypothesis was tested in a cross-sectional study of four groups of HIV-infected subjects, including those who were seronegative, untreated virologic controllers [detectable viral load (VL) of <1000 copies/mL], untreated virologic non-controllers [VL > 10,000 copies/mL], and ART-mediated virologic controllers [VL < 75 copies/mL]. A longitudinal analysis of ART-treated subjects was also performed along with regression analysis to determine which biomarkers were associated with and/or predictive of CD4(+) T cell recovery. Suppressive ART was associated with increased levels of classical monocyte subpopulations (CD14(hi)CD16(-)) and decreased levels of non-classical monocyte populations (CD14(dim)CD16(+)). Among peripheral blood mononuclear cells (PBMCs), HO-1 was found to be most highly up-regulated in CD14(+) monocytes after ex vivo stimulation. Neither the levels of monocyte subpopulations nor of HO-1 expression in CD14(+) monocytes were significantly associated with the degree of CD4(+) T cell recovery. Monocyte subpopulations and HO-1 gene expression were, however, restored to normal levels by suppressive ART. These results suggest that the level of circulating monocyte subpopulations and their expression of HO-1 have no evident relationship to CD4(+) T cell recovery after the initiation of ART

Stresul oxidativ în infecţiile de tract urinar la copii

Summary The preoperative and postoperative characteristics of the oxidative stress in children with urinary infections are presented, as well as the complications that can occur as a result of lipids peroxide oxidation. Introducere. Infecţiile tractului urinar reprezintă motivul pentru care copiii frecvent sunt consultaţi de medic. Lucrarea are caracter prospectiv şi analizează copiii cu malformaţii renourinare, asociate cu infecţie de tract urinar. Obiectivele lucrării. Stabilirea rolului radicalilor liberi în fiziopatologia infecţiei de tract urinar la copii, justificarea profilaxiei antioxidante şi reducerea stresului oxidativ la nivelul răspunsului inflamator sistemic. Material şi metode. Grupul de studiu cuprinde 342 copii cu vârstă de la 0 la 18 ani cu infecţie de tract urinar ce a survenit pe fundal de anomalii congenitale (rinichi dublu, rinichi în “potcoavă”, rinichi hipoplaziat, hidronefroză). Lotul martor a cuprins 20 copii practic sănătoşi. Determinarea indicilor proceselor de peroxidare lipidică şi activitatea antioxidantă serică s-a efectuat după metoda standard spectrofotometrică. S-a acceptat ca normă valoarea de 1,43 ± 0,13 un/ml pentru dienele conjugate (DC), 2,80 ± 0,20 mmol/l pentru dialdehida malonică (DAM), 35,20+1,42 % pentru activitatea antioxidantă totală (AAO). Evaluarea indicilor s-a efectuat începând cu internarea pacientului. S-a continuat determinarea lor în dinamică, la intervale de 3-4 zile, la cele 5 etape clinicoevolutive. Tuturor pacienţilor li s-a făcut anestezie generală. Tehnicile chirurgicale au fost individualizate. Rezultate. La copiii cu malformaţii congenitale şi infecţie urinară la toate etapele, inclusiv intra- şi postoperator, s-a constatat prezenţa unui grad de stres oxidativ exprimat prin creşterea peroxidării lipidice şi printr-o scădere a activităţii sistemelor antioxidante enzimatice. Parametrii urmăriţi au fost mai majoraţi la pacienţii cu rinichi dublu, rinichi în “potcoavă”, corespunzător cu martorul DC - 5,50 ± 0,64 un/ml; DAM 7,50 ± 0,41, AAO - 15,10 ± 4,35 % faţă de martor şi au corelat cu modificările gazelor sângelui. S-a constatat un nivel preexistent crescut al peroxidării lipidice serice la internare, preoperator, exprimând un grad de stres oxidativ preexistent intervenţiei chirurgicale. Este de remarcat tendinţa de creştere precoce şi constantă a radicalilor liberi la a 4-a zi postoperator, cu o scădere către ziua a 10-a postoperator, până la valori foarte apropiate de lotul martor. Toţi pacienţii au beneficiat de o strategie sofisticată de apărare antioxidantă cu utilizarea acidului ascorbic, Vit.E, Acidului linoleic, Solcoseril, etc. Concluzii: 1. În baza unei prelucrări statistice, putem conchide: însăşi prezenţa infecţiei urinare în malformaţiile congenitale renale pare să inducă o creştere a peroxidării lipidice sistemice, deci un grad de stres oxidativ. 2. Intervenţia chirurgicală individualizată de urgenţă şi programată în malformaţiile congenitale este însoţită de o creştere a peroxidării lipidice şi induce un stres oxidativ semnificativ. Durata intervenţiei chirurgicale (2-3 ore) pare a fi un factor foarte important de stres oxidativ în contextul sindromului de răspuns inflamator sistemic postagresiv. 3. Modificările constatate în sistemul de peroxidare lipidică ar putea coinstitui un argument în favoarea folosirii acestui marcher ca indicator de prognostic privind riscul dezvoltării comlicaţiilor şi totodată justifică tentativa de profilaxie antioxidantă, în scopul reducerii stresului oxidativ şi deci a nivelului răspunsului inflamator sistemic

Obstrucția infravezicală la copii

Summary Analyze the diagnostical experience and treatment of 505 children with IVO - including 320 girls with meatal stenozis, 163 boys with congenital stenozis and 22 with valves of posterior urethra. The diagnostical methods of IVO include miction cistourethrografy, uretrocistoscopy, and urethral calibration. The treatment of obstruction ant its consequences consists in transurethral excision of stenozis and valves rehabilitation (re-establishment) of superior urinary ways and the tract

Investigation of opening position on natural cross ventilation for an isolated building

The opening position is one of the factors that affect the ventilation performance of a building. In this study, the effect of opening position on natural cross ventilation of isolated building was investigated. The airflow pattern and ventilation rate under different opening configurations were analyzed. Eight different opening configurations were considered, including aligned and unaligned openings, as well as vertical-opening design. Computational fluid dynamics (CFD) simulation with 3D steady-state RANS equation Shear Stress Transport (SST) k-ω turbulence model was used. The parameters of streamwise dimensionless wind speed ratio (U/Uref), pressure coefficient (Cp) and dimensionless flow rate (DFR) were analyzed in this study. The results show that the aligned opening configuration Top-Top has the highest DFR at 0.60. This result is similar to that obtained from the literature. In addition, the design of vertical openings can improve the DFR of the building. The DFR of the building is mainly affected by the position of the opening on the windward side. This concludes that the opening positions exert an imperative role in affecting the internal airflow pattern, air recirculation and DFR of a naturally cross ventilated building

The radionudeide cystoureterography and uroflowmetry

IMSPIMC, Centrul Naţional Știinţifico-Practic de Chirurgie Pediatrică "Natalia Gheorghiu", Catedra de Chirurgie Pediatrică, Departamentul de urologie pediatrică, Al VI-lea Congres de Urologie, Dializă şi Transplant Renal din Republica Moldova cu participare internaţională (21-23 octombrie 2015)În articol sunt prezentate rezultatele unui studiu privind diagnosticarea refluxului vezico-renal şi aprecierea urodinamicii ureterului refluxant, realizat pe un lot de 42 pacienţi, trataţi în cadrul CNŞP de Chirugie Pediatrică„Natalia Georghiu". Rezultatele studiului au demonstrat că urofloumetria radionudeidă oferă informaţie sumară şi regională privind vezica urinară, uretra posterioară şi anterioară.Summary This article presents the results of a study for diagnosis the renal vesicoureteral reflux and ureteral urodynamics reflux, conducted on a sample of 42 patients treated in the Pediatric Surgery of National Scientific and Practical Center of Pediatric Surgery "Natalia Gheorghiu". The study results demonstrated that radionuclides uroflowmetry provides summary and regional information about the bladder and the anterior and posterior urethra

Correlations between VIMS and RADAR data over the surface of Titan: Implications for Titan's surface properties

We apply a multivariate statistical method to Titan data acquired by different instruments onboard the Cassini spacecraft. We have searched through Cassini/VIMS hyperspectral cubes, selecting those data with convenient viewing geometry and that overlap with Cassini/RADAR scatterometry footprints with a comparable spatial resolution. We look for correlations between the infrared and microwave ranges the two instruments cover. Where found, the normalized backscatter cross-section obtained from the scatterometer measurement, corrected for incidence angle, and the calibrated antenna temperature measured along with the scatterometry echoes, are combined with the infrared reflectances, with estimated errors, to produce an aggregate data set, that we process using a multivariate classification method to identify homogeneous taxonomic units in the multivariate space of the samples.In medium resolution data (from 20 to 100. km/pixel), sampling relatively large portions of the satellite's surface, we find regional geophysical units matching both the major dark and bright features seen in the optical mosaic. Given the VIMS cubes and RADAR scatterometer passes considered in this work, the largest homogeneous type is associated with the dark equatorial basins, showing similar characteristics as each other on the basis of all the considered parameters.On the other hand, the major bright features seen in these data generally do not show the same characteristics as each other. Xanadu, the largest continental feature, is as bright as the other equatorial bright features, while showing the highest backscattering coefficient of the entire satellite. Tsegihi is very bright at 5 μm but it shows a low backscattering coefficient, so it could have a low roughness on a regional scale and/or a different composition. Another well-defined region, located southwest of Xanadu beyond the Tui Regio, seems to be detached from the surrounding terrains, being bright at 2.69, 2.78 and 5 μm but having a low radar brightness. In this way, other units can be found that show correlations or anti-correlations between the scatterometric response and the spectrophotometric behavior, not evident from the optical remote sensing data. © 2010 Elsevier Inc

Titan's diverse landscapes as evidenced by Cassini RADAR's third and fourth looks at Titan

International audienceCassini's third and fourth radar flybys, T7 and T8, covered diverse terrains in the high southern and equatorial latitudes, respectively. The T7 synthetic aperture radar (SAR) swath is somewhat more straightforward to understand in terms of a progressive poleward descent from a high, dissected, and partly hilly terrain down to a low flat plain with embayments and deposits suggestive of the past or even current presence of hydrocarbon liquids. The T8 swath is dominated by dunes likely made of organic solids, but also contain somewhat enigmatic, probably tectonic, features that may be partly buried or degraded by erosion or relaxation in a thin crust. The dark areas in T7 show no dune morphology, unlike the dark areas in T8, but are radiometrically warm like the dunes. The Huygens landing site lies on the edge of the T8 swath; correlation of the radar and Huygens DISR images allows accurate determination of its coordinates, and indicates that to the north of the landing site sit two large longitudinal dunes. Indeed, had the Huygens probe trajectory been just 10 km north of where it actually was, images of large sand dunes would have been returned in place of the fluvially dissected terrain actually seen?illustrating the strong diversity of Titan's landscapes even at local scales