Garbage Collection Algorithms

This thesis focuses on an implementation of automatic memory management in C programming language. Mark-sweep method was modified for use in uncooperative programming language, which does not share data type information of memory slots accessible by the mutator. Due to this fact, decisions on pointer identity are conservative which guarantees safe collector operation - if value looks sufficiently like a pointer, it is considered a pointer (although it might not actually be one). Mark bits were moved from object's headers to bitmaps, stored in a seperate part of memory to prevent accidental writes to user's data by the collector. Finally, the usage of garbage collector was evaluated in practice

Garbage Collection Algorithms

This thesis focuses on an implementation of automatic memory management in C programming language. Mark-sweep method was modified for use in uncooperative programming language, which does not share data type information of memory slots accessible by the mutator. Due to this fact, decisions on pointer identity are conservative which guarantees safe collector operation - if value looks sufficiently like a pointer, it is considered a pointer (although it might not actually be one). Mark bits were moved from object's headers to bitmaps, stored in a seperate part of memory to prevent accidental writes to user's data by the collector. Finally, the usage of garbage collector was evaluated in practice

Monitoring and characterization of corrosion processes on steel in concrete

The aim of this thesis was to perform a critical comparison of a number of different electrochemical and physical methods for the monitoring of steel corrosion in concrete. Initially, some tests were performed on medium-sized reinforced-concrete columns located in a natural marine environment, into which electrical resistance probes were embedded. Electrochemical noise was measured using a\ud five-electrode assembly, and corrosion potentials and rates were determined by the galvanostatic pulse technique. Since the results obtained in the case of these in situ measurements proved to be relatively unreliable, further research was performed in the laboratory on small-scale test specimens using electrical impedance spectroscopy in addition to the previously described test methods. The small size of the specimens made it possible to also perform X-ray micro tomography analysis, which proved to\ud be highly important for our research results. These laboratory measurements were performed on different types of steel, which were embedded in carbonated mortar. The specimens were cyclically wetted with distilled water or a 3.5 % NaCl solution. The most reliable method for corrosion\ud monitoring proved to be a coupled multi-electrode array. However, this method is difficult to install in actual structures, and a large amount of recorded data has to be processed. Good results were also obtained on similar test specimens using a simpler method with electrical resistance probes, which, however, has some disadvantages in chloride environments at high corrosion rates. The galvanostatic\ud pulse technique, which is one of the most commonly used techniques for in situ corrosion monitoring, proved, on the basis of these laboratory tests, to be less reliable in the case of chloride contaminated concrete or mortar. On the other hand, X-ray computed micro-tomography turned out to be an extremely reliable non-destructive laboratory technique for the detection of corrosion type and the\ud extent of corrosion damage. This technique was therefore used to evaluate the accuracy of the other used methods

Treatment of Severe Steroid-Refractory Acute-Graft-vs.-Host Disease With Mesenchymal Stem Cells–Single Center Experience

The most effective treatment of steroid refractory acute graft vs. host disease (aGvHD) is not yet established and mesenchymal stem cells (MSC) appear to be a promising therapy for the condition. We report single center case series of three patients, who underwent allogeneic hematopoietic cell transplantation and later developed steroid refractory graft-vs.-host disease, treated with MSC infusions. Two patients achieved complete remission and one patient partial remission of skin and/or gastrointestinal aGvHD. We demonstrated application of MSC for treatment of severe steroid refractory aGvHD is feasible in clinical practice. Detailed description of patient's features and MSC production protocol is crucial for future comparison on efficacy and safety of cell-based therapies. However, for any substantial conclusions regarding efficacy of MSC higher patient numbers will be required

Chemical and toxicological characterisation of anticancer drugs in hospital and municipal wastewaters from Slovenia and Spain

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Risk of subsequent primary lymphoma in a cohort of 69,460 five-year survivors of childhood and adolescent cancer in Europe: The PanCareSurFup study.

BACKGROUND Survivors of Hodgkin lymphoma (HL) are at risk of developing non-Hodgkin lymphoma (NHL) after treatment; however, the risks of developing subsequent primary lymphomas (SPLs), including HL and NHL, after different types of childhood cancer are unknown. The authors quantified the risk of SPLs using the largest cohort of childhood cancer survivors worldwide. METHODS The Pan-European Network for Care of Survivors After Childhood and Adolescent Cancer (PanCare) Survivor Care and Follow-Up Studies (PanCareSurFup) cohort includes 69,460 five-year survivors of childhood cancer, diagnosed during 1940 through 2008, from 12 European countries. Risks of SPLs were quantified by standardized incidence ratios (SIRs) and relative risks (RRs) using multivariable Poisson regression. RESULTS Overall, 140 SPLs, including 104 NHLs and 36 HLs, were identified. Survivors were at 60% increased risk of an SPL compared with the general population (SIR, 1.6; 95% confidence interval [CI], 1.4-1.9). Survivors were twice as likely to develop NHL (SIR, 2.3; 95% CI, 1.9-2.8), with the greatest risks among survivors of HL (SIR, 7.1; 95% CI, 5.1-10.0), Wilms tumor (SIR, 3.1; 95% CI, 1.7-5.7), leukemia (SIR, 2.8; 95% CI, 1.8-4.4), and bone sarcoma (SIR, 2.7; 95% CI, 1.4-5.4). Treatment with chemotherapy for any cancer doubled the RR of NHL (RR, 2.1; 95% CI, 1.2-3.9), but treatment with radiotherapy did not (RR, 1.2; 95% CI, 0.7-2.0). Survivors were at similar risk of developing a subsequent HL as the general population (SIR, 1.1; 95% CI, 0.8-1.5). CONCLUSIONS In addition to HL, the authors show here for the first time that survivors of Wilms tumor, leukemia, and bone sarcoma are at risk of NHL. Survivors and health care professionals should be aware of the risk of NHL in these survivors and in any survivors treated with chemotherapy

Risk of subsequent gliomas and meningiomas among 69,460 5-year survivors of childhood and adolescent cancer in Europe:the PanCareSurFup study

BACKGROUND: Childhood cancer survivors are at risk of subsequent gliomas and meningiomas, but the risks beyond age 40 years are uncertain. We quantified these risks in the largest ever cohort.METHODS: Using data from 69,460 5-year childhood cancer survivors (diagnosed 1940-2008), across Europe, standardized incidence ratios (SIRs) and cumulative incidence were calculated.RESULTS: In total, 279 glioma and 761 meningioma were identified. CNS tumour (SIR: 16.2, 95% CI: 13.7, 19.2) and leukaemia (SIR: 11.2, 95% CI: 8.8, 14.2) survivors were at greatest risk of glioma. The SIR for CNS tumour survivors was still 4.3-fold after age 50 (95% CI: 1.9, 9.6), and for leukaemia survivors still 10.2-fold after age 40 (95% CI: 4.9, 21.4). Following cranial radiotherapy (CRT), the cumulative incidence of a glioma in CNS tumour survivors was 2.7%, 3.7% and 5.0% by ages 40, 50 and 60, respectively, whilst for leukaemia this was 1.2% and 1.7% by ages 40 and 50. The cumulative incidence of a meningioma after CRT in CNS tumour survivors doubled from 5.9% to 12.5% between ages 40 and 60, and in leukaemia survivors increased from 5.8% to 10.2% between ages 40 and 50.DISCUSSION: Clinicians following up survivors should be aware that the substantial risks of meningioma and glioma following CRT are sustained beyond age 40 and be vigilant for symptoms.</p