Estimation and analysis of multi-GNSS differential code biases using a hardware signal simulator

In ionospheric modeling, the differential code biases (DCBs) are a non-negligible error source, which are routinely estimated by the different analysis centers of the International GNSS Service (IGS) as a by-product of their global ionospheric analysis. These are, however, estimated only for the IGS station receivers and for all the satellites of the different GNSS constellations. A technique is proposed for estimating the receiver and satellites DCBs in a global or regional network by first estimating the DCB of one receiver set as reference. This receiver DCB is then used as a ‘known’ parameter to constrain the global ionospheric solution, where the receiver and satellite DCBs are estimated for the entire network. This is in contrast to the constraint used by the IGS, which assumes that the involved satellites DCBs have a zero mean. The ‘known’ receiver DCB is obtained by simulating signals that are free of the ionospheric, tropospheric and other group delays using a hardware signal simulator. When applying the proposed technique for Global Positioning System legacy signals, mean offsets in the order of 3 ns for satellites and receivers were found to exist between the estimated DCBs and the IGS published DCBs. It was shown that these estimated DCBs are fairly stable in time, especially for the legacy signals. When the proposed technique is applied for the DCBs estimation using the newer Galileo signals, an agreement at the level of 1–2 ns was found between the estimated DCBs and the manufacturer’s measured DCBs, as published by the European Space Agency, for the three still operational Galileo in-orbit validation satellites

Morphological characterization of the blood cells in the endangered Sicilian endemic pond turtle,Emys trinacris(Testudines: Emydidae)

In this study, measurements of morphological parameters, sizes and frequencies of peripheral blood cells (erythrocytes, leukocytes, thrombocytes) on blood smear preparation devices stained with May-Grünwald stain were evaluated for both sexes in 20 Emys trinacris (Testudines: Emydidae) specimens. Erythrocytes were higher in male than in female specimens. The leukocyte of E. trinacris contains eosinophil, basophil, monocyte, heterophil and lymphocyte. The eosinophil was higher in males than in females whereas lymphocytes were higher in females than in males. The erythrocyte morphological parameters (EL [erythrocyte length], EW [erythrocyte width], L/W [length/width], ES [erythrocyte size]) were compared with the same data from Emys orbicularis s.l, and from species belonging to other chelonian genera. The erythrocyte size did not vary within the studied Palearctic Emys taxa, whereas it proved to differ from that observed in other chelonians

Dialysis and pediatric acute kidney injury: choice of renal support modality

Dialytic intervention for infants and children with acute kidney injury (AKI) can take many forms. Whether patients are treated by intermittent hemodialysis, peritoneal dialysis or continuous renal replacement therapy depends on specific patient characteristics. Modality choice is also determined by a variety of factors, including provider preference, available institutional resources, dialytic goals and the specific advantages or disadvantages of each modality. Our approach to AKI has benefited from the derivation and generally accepted defining criteria put forth by the Acute Dialysis Quality Initiative (ADQI) group. These are known as the risk, injury, failure, loss, and end-stage renal disease (RIFLE) criteria. A modified pediatrics RIFLE (pRIFLE) criteria has recently been validated. Common defining criteria will allow comparative investigation into therapeutic benefits of different dialytic interventions. While this is an extremely important development in our approach to AKI, several fundamental questions remain. Of these, arguably, the most important are “When and what type of dialytic modality should be used in the treatment of pediatric AKI?” This review will provide an overview of the limited data with the aim of providing objective guidelines regarding modality choice for pediatric AKI. Comparisons in terms of cost, availability, safety and target group will be reviewed

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Changes in the size distribution of goat steroidogenic luteal cells during pregnancy

WOS: 000181212200007Experiments were conducted to investigate the size distribution of goat steroidogenic luteal cells throughout pregnancy. Corpora lutea were collected from very early ( 0.01) as pregnancy progressed. Mean diameter of 3beta-HSD positive cells increased from 14.73 +/- 0.35 mum in the corpus luteum of very early pregnancy to 24.20 +/- 0.45 mum in the corpus luteum of late pregnancy. The ratio of large (>20 mum in diameter) to small (5-20 mum in diameter) luteal cells was 0.28:1.0 in very early pregnancy, with the 7.5-15 mum cell size class being dominant. However, the ratio of large-to-small luteal cells was increased to 1.77:1.0 mum as pregnancy advanced and 25-35 mum cell sizes became predominant. It is likely that small luteal cells could develop into large cells as pregnancy progresses. Development of pregnancy is also associated with an increase in size of steroidogenic luteal cells. (C) 2002 Elsevier Science B.V. All rights reserved

Size distribution of steroidogenic and non-steroidogenic ovine luteal cells throughout pregnancy

WOS: 000179577200011The present study examines the size distribution of ovine steroidogenic and non-steroidogenic luteal cells throughout pregnancy. Cells were isolated from corpora lutea collected from early (:! 8 weeks), mid (9 to 14 weeks) or late (15 to 18 weeks) stages of pregnancy. Cells were stained for 3,3beta-hydroxysteroid dehydrogenase (3beta-HSD) activity, a marker for steroidogenic cells. Both 3beta-HSD positive and beta-HSD negative cells covered a wide spectrum of size ranging from 7 to 37mum in diameter. There was a significant increase (P > 0.01) in mean diameter of nonsteroidogenic luteal cells as pregnancy progressed. Mean diameter of 3beta-HSD negative cells increased from 17.8 (s.e. 0.4) mum in the corpus luteum of early stage of pregnancy to 22.4 (s.e. 0.3) mum in the corpus luteum of advanced pregnancy. However, there was no significant increase in the mean diameter of 3beta-HSD positive cells. Corpora lutea obtained from early stages of the pregnancy contained more steroidogenic cells than the cells obtained from mid and late pregnancy (P < 0.01). Percentage of 3beta-HSD negative cells had increased 2.07-fold by 18 weeks of pregnancy when compared with the early stage of pregnancy. In contrast, percentage of 3,3beta-HSD positive cells had decreased to 50% of starting values during the same period (P < 0.05). These results indicate that the ovine corpus luteum of pregnancy is morphologically dynamic over the course of pregnancy. Steroidogenic activity of luteal cells may decrease as pregnancy progresses, especially activity of the large luteal cells