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[en] Recently, Warm (keV scale) Dark Matter emerged impressively over CDM (Cold Dark Matter) as the leading Dark Matter candidate. In the context of this new Dark Matter situation, which implies novelties in the astrophysical, cosmological and keV particle physics context, this 16. Paris Colloquium 2012 is devoted to the LambdaWDM Standard Model of the Universe. The topics of the colloquium are as follows: -) observational and theoretical progress on the nature of dark matter: keV scale warm dark matter, -) large and small scale structure formation in agreement with observations at large scales and small galactic scales, and -) neutrinos in astrophysics and cosmology. This document gathers the slides of the presentations.
[en] Several natural hazards exhibit power-law behavior on their frequency-size distributions. Self-organized criticality has become a promising candidate that could offer a more in-depth understanding of the origin of temporal and spatial scaling in dissipative nonequilibrium systems. The outcomes of this thesis are presented in three scientific papers followed by a concluding summary and an appendix.In paper (A) we present a semi-phenomenological approach to explain the complex scaling behavior of the Drossel-Schwabl forest-fire model (DS-FFM) in two dimensions. We derive the scaling exponent solely from the scaling exponent of the clusters' accessible perimeter. Furthermore, the unusual transition to an exponential decay is explained both qualitatively and quantitatively. The exponential decay itself could be reproduced at least qualitatively. In paper (B) we extend the DS-FFM towards anthropogenic ignition factors. The main outcomes are an increase of the scaling exponent with decreasing lightning probability as well as a splitting of the partial frequency-size distributions of lightning induced and man made fires. Lightning is identified as the dominant mechanism in the regime of the largest fires. The results could be validated through an analysis of the Canadian Large Fire Database.In paper (C) we obtain an almost complete theory of the Olami-Feder-Christensen (OFC) model's complex spatio-temporal behavior. Synchronization pushes the system towards a critical state and generates the Gutenberg-Richter law. Desynchronization prevents the system from becoming overcritical and generates foreshocks and aftershocks. Our approach also provides a simple explanation of Omori's law. Beyond this, it explains the phenomena of foreshock migration and aftershock diffusion and the occurrence of large earthquakes without any foreshocks. A novel integer algorithm for the numerics is presented in appendix (A).(author)
[de]Die Größenverteilungen verschiedener Naturgefahren folgen einem einfachen Potenzgesetz. Das Konzept der selbstorganisierten Kritizität gilt als vielversprechender Kandidat für die Erklärung solchen skaleninvarianten Verhaltens.Die Ergebnisse werden in drei wissenschaftlichen Aufsätzen (Papers) präsentiert, gefolgt von einer Abschlussdiskussion und einem Anhang.In Paper (A) präsentieren wir einen semi-phänomenologischen Ansatz zur Erklärung des komplexen Verhaltens des DS-FFM in zwei Dimensionen. Wir berechnen den Potenzgesetz-Exponenten rein aus dem zugänglichen Umfang der Modell-Cluster und erklären den charakteristischen Übergang zu einem exponentiellen Abfall sowohl qualitativ als auch quantitativ; der exponentielle Abfall selbst konnten wir zumindest qualitativ reproduzieren. In Paper (B) erweitern wir das DS-FFM um anthropogene Einflüsse. Die Simulationen ergeben einen Anstieg des Exponenten für die Häufigkeitsverteilung aller Brände mit abnehmender Wahrscheinlichkeit von Blitzschlägen. Wir beobachten eine Aufspaltung der Brände in zwei Untermengen, deren zugehörige Partialverteilungen ebenfalls einem Potenzgesetz folgen. Die größten Brände sollten vorwiegend durch Blitzschlag verursacht werden. Die Vorhersagen konnten durch eine Analyse der kanadischen Large Fire Database bestätigt werden.In Paper (C) präsentieren wir eine Theorie für das komplexe Raum-Zeit-Verhalten des Olami-Feder-Christensen (OFC) Modells. Synchronisationseffekte treiben das System in Richtung eines kritischen Zustands und sind Ursache für das Gutenberg-Richter Gesetz. Desynchronisationseffekte verhindern einen überkritischen Zustand und erzeugen Vor- und Nachbeben. Unser Ansatz liefert eine einfache Erklärung für das Omori Gesetz und erklärt, warum starke Erdbeben auch ohne Vorbeben auftreten können. Darüber hinaus erklären wir das Phänomen der Migration von Erdbebenherden. Für die Simulationen wurde ein neuartiger Algorithmus entwickelt (Anhang A).(author)
[en] Elevation of intracellular free calcium concentration ([Ca2+]i) is a key signal during T cell activation and is commonly used as a read-out parameter for stimulation of T cell signaling. Upon T cell stimulation a variety of calcium signals is produced by individual cells of the T cell population and the type of calcium signal strongly influences cell fate decisions. The heterogeneous nature of T cells is masked in ensemble measurements, which highlights the need for single-cell measurements. In this study we used single-cell calcium measurements in Jurkat cells to investigate signaling pathways, which are triggered by different proteins, namely CD3 and CD59. By application of an automated cluster algorithm the presented assay provides unbiased analysis of a large data set of individual calcium time traces generated by the whole cell population. By using this method we could demonstrate that the Jurkat population generates heterogeneous calcium signals in a stimulus-dependent manner. Furthermore, our data revealed the existence of a link between CD3- and CD59-mediated signaling pathways. Single-cell calcium measurements in Jurkat cells expressing different levels of the T cell receptor (TCR) complex indicated that CD59-mediated calcium signaling is critically dependent on TCR surface expression levels. In addition, triggering CD59-mediated calcium signaling resulted in down-regulation of TCR surface expression levels, which is known to happen upon direct TCR triggering too. Moreover, by using siRNA-mediated protein knock-downs and protein knock-out Jurkat mutants we could show that CD3- and CD59-mediated calcium signaling require identical key proteins. We therefore explored by which mechanism CD59-mediated signaling couples into TCR-mediated signaling. Fluorescence recovery after photobleaching (FRAP) experiments and live-cell protein-protein interaction assays provided no evidence of a direct physical interaction between CD3- and CD59-mediated signaling pathways at the membrane level. Further testing for more downstream signaling molecules revealed that the src family kinase Lck is the most upstream possible candidate for mediating a link between CD59- and CD3-mediated signaling pathways. Measuring CD3 surface expression dynamics in Lck knock-down cells and forced interaction of Lck and CD3ζ upon anti-CD59 stimulation demonstrated that Lck is a key component coupling CD59-mediated signaling into the CD3-mediated signaling pathway. Altogether, these results support the idea that CD59 is acting as a modulator of TCR-mediated T cell activation. (author)
[de]Eines der wichtigsten Ereignisse bei der Aktivierung von T-Zellen ist der Anstieg der intrazellulären freien Kalziumkonzentration ([Ca2+]i) und ist damit Ausleseparameter für die Charakterisierung der Stimulation von T-Zellen. Wird eine T-Zellpopulation stimuliert, generieren die individuellen T-Zellen eine Vielfalt an verschiedenen Kalziumsignalen, welche das Schicksal einer T-Zelle beeinflussen. Diese Heterogenität in der T-Zellpopulation kommt erst bei der Anwendung von Einzelzellmessungen zum Vorschein. In dieser Studie haben wir daher Einzelzellkalziummessungen in Jurkat T-Zellen durchgeführt, um Signalwege zu untersuchen, die von zwei unterschiedlichen Proteinen, nämlich CD3 und CD59, ausgelöst werden. Für eine hypothesenfreie Analyse der individuellen Kalziumspuren in der Jurkat Zellpopulation wurde ein automatisierter Clusteralgorithmus implementiert. Mithilfe dieser Methode konnten wir heterogene Kalziumsignale innerhalb der Jurkat Zellpopulation nachweisen, welche vom spezifischen Stimulus (CD3 bzw. CD59) abhängig waren. Darüber hinaus haben unsere Daten gezeigt, dass eine Verknüpfung zwischen CD3- und CD59-vermittelten Signalwegen besteht. Einzelzellkalziummessungen in Jurkat Zellen mit unterschiedlich hohen Expressionsniveaus des T-Zellrezeptors (TCR) haben gezeigt, dass die CD59-vermittelte Kalziumsignalisierung von der Expression des TCR abhängt. Des Weiteren führte Stimulation der CD59-vermittelten Kalziumsignalisierung zu einer Herunterregulierung der Oberflächenexpression des TCR, ähnlich, wie sie auch für direkte Stimulierung des TCRs gezeigt wurde. Damit ergibt sich eine Kopplung der beiden Signalwege. Experimente mit siRNA-vermittelten Protein knock-downs und knock-out Jurkat Mutanten haben darüberhinaus gezeigt, dass beide Signalwege, CD3- und CD59-vermittelte, von identischen Schlüsselproteinen abhängen. Daher haben wir untersucht durch welchen Mechanismus die CD59-vermittelte Kalziumsignalisierung in den TCR-vermittelten Signalweg eingegliedert wird. Durch Anwendung von fluorescence recovery after photobleaching (FRAP) und eines live-cell protein-protein interaction assays konnten wir keine direkte physische Kopplung der beiden Signalwege auf Membranebene nachweisen. Jedoch konnten wir durch Experimente mit nachfolgenden Molekülen in der Signalkaskade die Proteintyrosinkinase Lck als den frühestmöglichen Kandidaten zur Vermittlung der Kopplung identifizieren. Durch Messung der CD3 Oberflächenexpression in Lck knock-down Zellen und erzwungener Interaktion zwischen Lck und CD3ζ konnten wir zeigen, dass Lck eine Schlüsselkomponente für die Kopplung der CD59-vermittelten Signalisierung in die CD3-vermittelte Signalisierung ist. Zusammenfassend unterstützen unsere Daten die Idee, dass CD59 als Modulator der TCR-vermittelten T-Zellaktivierung agiert. (author)
[en] BCG has been used for more than 30 years and is currently the most effective agent for non-muscle invasive bladder cancer therapy after transurethral resection. The high-grade T1 lesion treated by transurethral resection alone is reported to progress to muscle invasion in 30% to 50% of the patients. Until now, optimal treatment schedule and optimal dose have not been defined as the toxicity related to BCG therapy is significant. In this study we tried to evaluate the efficacy and toxicity of 60 mg intravesical BCG (Pasteur strain) therapy in patients with T1 transitional cell carcinoma of the bladder. Patients and Methods: From January 2000 till December 2007, 74 patients with single T1 transitional cell carcinoma (TCC) of the urinary bladder (grade 3 in 24 patients and grade 2 in 50 patients) were treated by complete transurethral resection followed by a 6-weeks course of 60 mg BCG intravesically. Follow-up ranged from 26- 96 months with median of 61 months. Results: Nine patients (12.1%) exhibited recurrence with muscle invasion after 6-18 months (5 with grade 3 tumors and 4 with grade 2), all were subjected to radical cystectomy and urine diversion. Whereas 19 patients (29.2%) showed recurrent T1 tumor after 16-45 months (7 with grade 3 tumors and 12 with grade 2) and were treated by TUR-T followed by a second 6-weeks course of 60 mg BCG intravesically. Recurrence index was 0.82/100 patients/month and the median tumor free period was 20 months. Regarding toxicity; irritative symptoms occurred in 24% of patients, fever in 9%, microscopic hematuria in 14%; which appeared to be significantly low when compared with the rates reported for higher doses of BCG. Conclusion: Intravesical therapy of 60 mg BCG is effective in prophylaxis against recurrence and progression of T1 TCC of the bladder. Decreasing the dose resulted
[en] Following gene expression profiling which compared the two well established prognostic markers in CLL, ZAP-70 and CD 38 with un mutated and mutated IgVH, ZAP-70 has emerged as the most promising surrogate marker for the IgVH mutation status. CD38 expression has also been suggested as a surrogate marker for the IgVH mutation status. Aim: We aimed to investigate the impact of ZAP-70 and CD38 expressions as well as their combined expressions on the treatment outcome and survival of our CLL patients. Patients and Methods: This study included 50 CLL patients as well as 10 normal volunteers as a control group. All patients were subjected to complete work up and immuno phenotyping to confirm the diagnosis. ZAP-70 and CD38 expressions were studied in (CD19 +, CD5+) B cells. Results were expressed as percent expression and mean flourecent index (MFI). Results were correlated to the treatment outcome and survival as well as to other prognostic markers of CLL including TLC, Hb level, platelets count, modified Rai staging at diagnosis, P53 and BCL 2. Results: A significant association was found between ZAP-70 percent expression and the diffuse pattern of bone marrow infiltration (p<0.002) as well as the P53 percent expression (p=0.005). A Significant increase in serum levels of LDH and B2M in ZAP-70 positive as compared to negative groups was detected (p=0.049 and 0.007 respectively). A higher number of non-responding patients was reported in the ZAP70 positive as compared to ZAP70 negative group (p<0.001). ZAP-70 percent expression was significantly associated with shorter time to disease progression (TDP) and shorter overall survival (p=0.025 and 0.029 respectively). A significant increase in serum levels of B2M in CD38 percent positive as compared to negative group was en- countered (p=0.045). CD38-MFI showed a significant associations to advanced modified Rai staging at diagnosis (p=0.019) and to higher serum levels of both LDH and B2M (p=0.03 and 0.05 respectively). CD38, either expressed as a percentage or as MFI, showed a significant association with the non-responders (p=0.034 and 0.006 respectively). There was a significant inverse relation between CD38 expression and time to disease progression (p=0.033) while no significant relation was encountered with overall survival (p=0.197). Combined expression of both markers, ZAP-70+ /CD38+ was reported in 5 patients (10%) while ZAP-70- /CD38- expression was encountered in 24 patients (48%). Patients with either ZAP-70+ or CD38+ represented 42% of the cases (21 patients).There were significant differences between the three groups and the initial response to chemotherapy (p=<0.001) and the pattern of bone morrow infiltration (p=0.015), while no significant relation was found with age, sex, modified Rai staging at diagnosis or BCL2 percent expression. Patients with combined expression of ZAP-70 and CD38 had significantly shorter TDP and overall survival (p<0.001 and 0.03 respectively). Conclusion: ZAP-70 is one of the most important prognostic markers in CLL, it appears to be more predictive of disease progression and poor outcome than CD38 expression. Semi quantification of the CD38 antigen by flow cytometry greatly improves the prognostic value of its expression. The combination of ZAP-70 and CD38 increases the prognostic power of either alone
[en] Hepcidin, a key regulator of iron metabolism, is synthesized by the liver. Hepcidin binds to the iron exporter ferroportin to regulate the release of iron into plasma from macrophages, hepatocytes, and enterocytes. Aim: To study hepcidin expression in liver tissue of patients with hepatocellular carcinoma (HCC), chronic hepatitis C (CHC) and normal human liver biopsies and to compare its level with serum and liver iron indices. Patients and Methods: Liver biopsies from 66 patients (36 HCC and 30 CHC) were analysed as well as normal human liver biopsies obtained from 20 healthy liver transplant donors as a control group. Liver function tests, AFP, hepatitis markers, HCV-RNA levels, hemoglobin concentration and serum iron parameters were analyzed. Hepcidin mRNA was quantified in all liver biopsies of patients and controls by real-time PCR. Liver iron concentration (LIC) was evaluated and hepatic iron index (HII) was calculated by dividing LIC in mmol/gm dry weight by the patient's age. Results: The mean level for hepcidin mRNA in HCC, CHC and healthy controls were 2351±505, 5735±2403 and 16308±2194 copies/ml, respectively; with significant decrease in cancerous (HCC) than non-cancerous (CHC) and control liver tissues. The level was significantly lower in patients with multiple tumour masses. Hepcidin mRNA had a significant positive correlation with synthetic function of the liver (serum albumin and prothrombin concentration) and haemoglobin. In contrast, hepcidin mRNA was negatively correlated with parameters of iron stores as (serum ferritin and HII) and grade of liver fibrosis in both patient groups. Conclusion: The expression of hepcidin mRNA is decreased in liver tissues of CHC patients and more suppressed in the liver tissues of patients with HCC, suggesting that hepcidin expression appears to be appropriately responsive to iron status and disease progression in cirrhosis and hepato carcinogenesis.
[en] Autocatalytic quaternary Ni-P-Cu-Fe film was prepared using NiCl2.6H2O, CuSO4, and Fe2SO4, as a source of metal ions and NaH2PO2 as a reducing agent. Energy dispersive X-ray analysis (EDAX) showed that the quaternary Ni-P-Cu-Fe alloy deposits contained 1.79% Fe, 6.38% P , 9.55% Cu and 82,28% Ni. Scanning electron microscopy (SEM) studies of the deposits showed smooth nodules for Ni-P-Cu-Fe coatings. The coating thickness was measured using weight method. The corrosion resistance properties of the Ni-P-Cu-Fe coatings in 3% NaCl solution were investigated by electrochemical potentiodynamic polarization technique. The results showed that the corrosion resistance of the Ni-P-Cu-Fe alloy coating was better than that of electroless Ni-P coating
[en] Immediately after unilateral nephrectomy, different mechanisms of compensatory adaptation begin to act followed by a restoration of sufficient kidney function in a short time period. Some animal studies showed that prostaglandins (PG) are important for renal function after unilateral nephrectomy. The aim of the present study was to investigate the role of prostaglandins on renal function in the fully adapted remnant kidney in healthy uninephrectomized sheep and the acute effect of indomethacin on renal haemodynamics. In order to investigate the importance of prostaglandins on the renal function in the fully adapted remnant kidney, indomethacin (0.8 mg/kg) was injected intravenously immediately before and after unilateral nephrectomy. Forty sheep with unilateral nephrectomy were divided randomly into two groups; twenty sheep (group 1) untreated with indomethacin (unsuppressed PG) and the other twenty ones (group 2) were treated with indomethacin (suppressed PG) before and after clamping the renal pedicle and then instantaneously, the glomerular filtration rate (GFR) and the effective renal plasma flow (ERPF) were measured using non-invasive radionuclide technique then the filtration fraction (FF) was calculated. The study showed that there was considerable and instantaneous increase in GFR (148%) and a proportionate increase in the ERPF (91%) in the remaining kidney post-uninephrectomy, and treatment with indomethacin for suppression of prostaglandins synthesis showed non-significant changes in these measured values. The present study showed enhanced function, as measured by GFR and ERPF, in the remaining kidney as a compensatory effect of unilateral nephrectomy and the changes are not prostaglandins mediated
[en] The project was reviewed new current IAEA documents on Radiation Protection and Safety of Radiation Sources GSR Part 3. The revised International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (commonly referred to as “the BSS”) are structured on the basis of 'planned exposure situations' , 'emergency exposure situations' and 'existing exposure situations', with each main section of the text having the same layout covering occupational exposure, public exposure and (for planned exposure situations only) medical exposure, following the ICRP 2007 recommendations. There is also a main section dealing with generic requirements that are applicable in all exposure situations. The revised BSS covers protection of the environment and is consistent with the Fundamental Safety Principles. It also covers protection of the Public exposure due to radon indoors and Exposure due to radionuclides in commodities. The revised BSS finally also cover protection against Exposure of aircrew and space crew due to cosmic radiation. Framework for source-related dose constraints and reference levels with examples of constraints for workers and the public from single dominant sources for all exposure situations that can be controlled are also covered .Some changes have been introduced for Tissue weighting factors and radiation weighting factors. Dose limits have not changed. Member States of IAEA are required to comment on the documents and adopt or adapted to update their radiation protection programmes to be consistent with the new recommendations. (author)
[en] This paper explores the feasibility of the electromagnetic acoustic resonance (EMAR) for monitoring the axial stresses in the railroad rails. An electromagnetic acoustic transducer (EMAT) is used to generate and detect the polarized shear waves propagating transversely to the rail axis. The EMAT is incorporated with a resonance spectrometer to accomplish the non-contacting stress measurements at the web, where the surfaces are nearly parallel with each other and support the thickness oscillations. Compressive axial load was raised until 60 tons with the Shinkansen (bullet train) rail samples, which exceeds the buckling load of long rails. Measured birefrengence showed a linear response to stress with a sufficient sensitivity and robustness, which promises the development to the practical railroad maintenance technology. The effects of the liftoff and the residual stress distribution are determined.