The cosmogenic radionuclide 7Be is one of the best tracers for aerosol transport since its half-life of 53 days is in the time scale of many atmospheric circulation phenomena. In this work, we ...analyze a 12-years-long daily time-series for the airborne 7Be concentration for nine air filtering stations in the Southern Hemisphere or close to it. The observed latitudinal distribution of 7Be concentration, with its maximum at the southern subtropical high-pressure belt, is similar to the one in the Northern Hemisphere. A good time correlation was found between the 7°-shift of the 7Be concentration latitudinal distribution and the seasonal displacement of the extent of the Hadley cell. This is consistent with tropopause folding events, mostly occurring in spring, being the main contribution for the injection of stratospheric 7Be into the descending branch of the Hadley cell.
•We analyzed 12-year long 7Be concentrations time series from the Southern Hemisphere.•The 7Be latitudinal distribution shows a maximum at the subtropical high-pressure belt.•Time correlation found between the shift of this distribution and the seasonal displacement of the Hadley cell.
•Bovine necrotic vulvovaginitis (BNVV) is a polymicrobial disease.•Neutrophil recruitment to the necrotic vaginal lesions is impaired.•There are significant differences in microbial composition ...between vulvovaginitis and BNVV lesions.•Indicators of BNVV include Parvimonas, Porphyromonas, Veillonellaceae and Mycoplasma.
Bovine necrotic vulvovaginitis (BNVV) is a severe and potentially fatal disease of post-partum cows that emerged in Israel after large dairy herds were merged. While post-partum cows are commonly affected by mild vulvovaginitis (BVV), in BNVV these benign mucosal abrasions develop into progressive deep necrotic lesions leading to sepsis and death if untreated. The etiology of BNVV is still unknown and a single pathogenic agent has not been found. We hypothesized that BNVV is a polymicrobial disease where the normally benign vaginal microbiome is remodeled and affects the local immune response. To this end, we compared the histopathological changes and the microbial communities using 16S rDNA metagenetic technique in biopsies taken from vaginal lesions in post-partum cows affected by BVV and BNVV.
The hallmark of BNVV was the formation of complex polymicrobial communities in the submucosal fascia and abrogation of neutrophil recruitment in these lesions. Additionally, there was a marked difference in the composition of bacterial communities in the BNVV lesions in comparison to the benign BVV lesions. This difference was characterized by the abundance of Bacteroidetes and lower total community membership in BNVV. Indicator taxa for BNVV were Parvimonas, Porphyromonas, unclassified Veillonellaceae, Mycoplasma and Bacteroidetes, whereas unclassified Clostridiales was an indicator for BVV. The results support a polymicrobial etiology for BNVV.
In the analysis of elastic-scattering experimental data, optical-model parameters (usually, depths of real and imaginary potentials) are fitted and conclusions are drawn analyzing their variations at ...bombardment energies close to the Coulomb barrier (threshold anomaly). The judgement about the shape of this variation (related to the physical processes producing this anomaly) depends on these fitted values but the robustness of the conclusions strongly depends on the uncertainties with which these parameters are derived. We will show that previous published studies have not used a common criteriumfor the evaluation of the parameter uncertainties. In this work, a study of these uncertainties is presented, using conventional statistic tools as well as bootstrapping techniques. As case studies, these procedures are applied to re-analyze detailed elastic-scattering data for the 12C + 208Pb and the 6Li + 80Se systems.
Autoimmune glomerulonephritis (GN) is a potentially life-threatening renal inflammation occurring in a significant percentage of systemic lupus erythematosus (SLE) patients. It has been suggested ...that GN develops and persists due to a positive feedback loop, in which inflammation is promoted by the deposition in the kidney of immune complexes (IC) containing double-stranded DNA (dsDNA) and autoantibodies specific to it, leading to cellular death, additional release to circulation of dsDNA, continuous activation of dsDNA-specific autoreactive B cells and further formation of IC. We have recently presented a generic model exploring the dynamics of IC-mediated autoimmune inflammatory diseases, applicable also to GN. Here we extend this model by incorporating into it a specific B cell response targeting anti-dsDNA antibodies—a phenomenon whose occurrence in SLE patients is well-supported empirically. We show that this model retains the main results found for the original model studied, particularly with regard to the sensitivity of the steady state properties to changes in parameter values, while capturing some disease-specific observations found in GN patients which are unaccountable using our previous model. In particular, the extended model explains the findings that this inflammation can be ameliorated by treatment without lowering the level of anti-dsDNA antibodies. Moreover, it can account for the inverse oscillations of anti-dsDNA and anti–anti-dsDNA antibodies, previously reported in lupus patients. Finally, it can be used to suggest a possible explanation to the so-called regulatory role of TLR9, found in murine models of lupus; i.e., the fact that the knockdown of this DNA-sensing receptor leads, as expected, to a decrease in the level of anti-dsDNA antibodies, but at the same time results in a counter-intuitive amplification of the autoreactive immune response and an exacerbated inflammation. Several predictions can be derived from the analysis of the presented model, allowing its experimental verification.
► Anti–anti-dsDNA Abs explain the persistence of anti-dsDNA Abs in disease remission. ► Their occurrence does not change the parameter sensitivity of IC-mediated disease. ► These Abs explain why the knockout of TLR9 can lead to an exacerbated inflammation. ► Limit cycles account for reported inverse oscillations of the two antibody types.
A number of autoimmune diseases are thought to feature a particular type of self-sustaining inflammation, caused by the deposition of immune complexes (IC) in the inflamed tissue and a consequent ...activation of local effector cells. The persistence of this inflammation is due to a positive feedback loop, where autoantigen particles released as part of the tissue damage caused by the inflammation stimulate autoreactive B cells, leading to the formation of further immune complexes and their subsequent deposition. We present a mathematical model for the exploration of IC-mediated autoimmune inflammation and its clinical implications. We characterize the possible differences between normal individuals and those susceptible to such inflammation, and show that both random perturbations and bifurcations can lead to disease onset. Our model explains how defects in the mechanisms responsible for cellular debris clearance contribute to the development of disease, in agreement with empirical evidence. Moreover, we show that parameters governing the dynamics of immune complexes, such as their clearance rate, have an even stronger effect in determining the behavior of the system. We demonstrate the existence of hysteresis, implying that once IC-mediated autoimmune inflammation is triggered, its long-term suppression may be difficult to achieve. Our results can serve to guide the development of novel therapies to autoimmune diseases involving this type of inflammation.
The 10Be/9Be ratios in marine sediments samples from the Southern Chile Trench have been measured using accelerator mass spectrometry (AMS). The samples were measured at the TANDAR accelerator, where ...the discrimination of the 10Be radionuclides was achieved by means of a passive absorber in front of an ionization chamber. This setup along with the high voltage available, provided a complete suppression of the 10B isobar interference. The obtained values for the 10Be concentrations, of the order of 109atoms/g, are the first 10Be measurements from the Southern Chile Trench and offer an excellent tracer to quantitatively study the recycling of sediments in Andean magmas.
Radioactive Ion beams in Brazil (RIBRAS) Lichtenthäler, R.; Lépine-Szily, A.; Guimar aes, V. ...
The European physical journal. A, Hadrons and nuclei,
09/2005, Letnik:
25, Številka:
S1
Journal Article
129I/127I ratios and iodine concentrations in bovine thyroids stemming from Argentina were determined by accelerator mass spectrometry (AMS) and gas chromatography (GC), respectively. From these ...measurements, a relationship of the 129I/127I ratio with iodine content in the gland was obtained. A weak correlation between the two isotopes was found, suggesting that 129I re-emission from the ocean is not the only process for the 129I deposition in Argentina. Moreover, contributions to the total 129I inventory in the Southern hemisphere from both natural and anthropogenic sources were theoretically studied. Surface compartments present similar contribution from natural sources and nuclear explosions fallout.
129I and 127I concentrations in animal thyroids coming from several regions of Argentina were determined by accelerator mass spectrometry (AMS) and gas chromatography (GC), respectively. The measured ...129I/127I ratios, ranging from 3×10−12 to 4×10−10, are significantly lower than those typical for areas in the northern hemisphere (10−10–10−7). The 129I concentrations show a clear dependence with latitude and season, which can be understood considering tropospheric circulation patterns, possible 129I sources and regional precipitation rates.
► This is the first determination of 129I in thyroids from the southern hemisphere via AMS. ► Isotopic ratios measured are lower than those found in areas of the northern hemisphere. ► Two samples represent 129I/127I ratios similar to pre-anthropogenic values. ► Our data show a clear dependence with latitude and season, related with deposition pathways. ► We find a strong decorrelation between 129I and iodine sources.
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