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

Stuck in the slow lane: reconceptualising the links between gender, transport and social exclusion

This article draws upon primary research undertaken with over 3,000 women in the North East of England to explore the links between women, transport and the labour market. The research, funded by the ESF, advances the idea of spatiality as a social construction and builds on seminal studies relating to women and poverty to consider the way in which a gender division of transport constrains women's mobility and restricts their employment opportunities. It is likely to contribute to important debates, concerning strategies to tackle worklessness and the most effective spatial level at which to configure public transport networks

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

Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) after nine years of operation: a summary

Mars Express, the first European interplanetary mission, carries the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) to search for ice and water in the Martian subsurface. Developed by an Italian–US team, MARSIS transmits low-frequency, wide-band radio pulses penetrating below the surface and reflected by dielectric discontinuities linked to structural or compositional changes. MARSIS is also a topside ionosphere sounder,transmitting a burst of short, narrow-band pulses at different frequencies that are reflected by plasma with varying densities at different altitudes.The radar operates since July 2005, after the successful deployment of its 40 m antenna, acquiring data at altitudes lower than 1200 km. Subsurface sounding (SS)data are processed on board by stacking together a batch of echoes acquired at the same frequency. Onground, SS data are further processed by correlating the received echo with the transmitted waveform and compensating de-focusing caused by the dispersive ionosphere. Ground processing of active ionospheric sounding (AIS)data consists in the reconstruction of the electron density profile as a function of altitude. MARSIS observed the internal structure of Planum Boreum outlining the Basal Unit, an icy deposit lying beneath the North Polar Layered Deposits thought to have formed in an epoch in which climate was markedly different from the current one.The total volume of ice in polar layered deposits could be estimated, and parts of the Southern residual ice cap were revealed to consist of 10 m of CO2 ice. Radar properties of the Vastitas Borealis Formation point to the presence of large quantities of ice buried beneath the surface. Observations of the ionosphere revealed the complex interplay between plasma, crustal magnetic field and solar wind, contributing to space weather studies at Mars. The presence of three-dimensional plasma structures in the ionosphere was revealed for the first time. MARSIS could successfully operate at Phobos, becoming the first instrument of its kind to observe an asteroid-like body. The main goal pursued by MARSIS, the search for liquid water beneath the surface, remains elusive. However, because of the many factors affecting detection and of the difficulties in identifying water in radar echoes, a definitive conclusion on its presence cannot yet be drawn

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

Rem2-Targeted shRNAs Reduce Frequency of Miniature Excitatory Postsynaptic Currents without Altering Voltage-Gated Ca2+ Currents

Ca2+ influx through voltage-gated Ca2+ channels (VGCCs) plays important roles in neuronal cell development and function. Rem2 is a member of the RGK (Rad, Rem, Rem2, Gem/Kir) subfamily of small GTPases that confers potent inhibition upon VGCCs. The physiologic roles of RGK proteins, particularly in the brain, are poorly understood. Rem2 was implicated in synaptogenesis through an RNAi screen and proposed to regulate Ca2+ homeostasis in neurons. To test this hypothesis and uncover physiological roles for Rem2 in the brain, we investigated the molecular mechanisms by which Rem2 knockdown affected synaptogenesis and Ca2+ homeostasis in cultured rat hippocampal neurons. Expression of a cocktail of shRNAs targeting rat Rem2 (rRem2) reduced the frequency of miniature excitatory postsynaptic currents (mEPSCs) measured 10 d after transfection (14 d in vitro), but did not affect mEPSC amplitude. VGCC current amplitude after rRem2-targeted knockdown was not different from that in control cells, however, at either 4 or 10 d post transfection. Co-expression of a human Rem2 that was insensitive to the shRNAs targeting rRem2 was unable to prevent the reduction in mEPSC frequency after rRem2-targeted knockdown. Over-expression of rRem2 resulted in 50% reduction in VGCC current, but neither the mEPSC frequency nor amplitude was affected. Taken together, the observed effects upon synaptogenesis after shRNA treatment are more likely due to mechanisms other than modulation of VGCCs and Ca2+ homeostasis, and may be independent of Rem2. In addition, our results reveal a surprising lack of contribution of VGCCs to synaptogenesis during early development in cultured hippocampal neurons