Simultaneous Doppler maps of IP Peg in outburst

IP Pegasi is an eclipsing dwarf nova lying above the period gap with an orbital period of 3.8h. It is the first cataclysmic variable to show evidence of spiral arms in its accretion disc. We present new time-resolved echelle spectroscopic observations of IP Peg, covering the 3900-7700 Angstrom range. This allows us to produce simultaneous Doppler Maps in 9 emission lines

IP Pegasi in outburst: Echelle spectroscopy & Modulation Doppler Tomography

We analyse a unique set of time-resolved echelle spectra of the dwarf nova IP Peg, obtained at ESO's NTT with EMMI. The dataset covers the wavelength range of 4000-7500A and shows Balmer, HeI, HeII and heavier elements in emission. IP Peg was observed one day after the peak of an outburst. The trailed spectra, spectrograms and Doppler maps show characteristics typical of IP Pegasi during the early stages of its outburst. The high-ionisation line of HeII 4686A is the most centrally located line and has the greatest radial extension compared to the HeI lines. The Balmer lines extend from close to the white dwarf up to approximately 0.45 times R_L, with the outer radius gradually increasing when moving from H delta to H alpha. The application, for the first time, of the modulation Doppler tomography technique, maps any harmonically varying components present in the system configuration. We find, as expected, that part of the strong secondary star emission in Balmer and HeI lines is modulated predominantly with the cosine term, consistent with the emission originating from the irradiated front side of the mass-donor star, facing the accreting white dwarf. For the Balmer lines the level of the modulation, compared to the average emission, decreases when moving to higher series. Emission from the extended accretion disk appears to be only weakly modulated, with amplitudes of at most a few percent of the non-varying disk emission. We find no evidence of modulated emission in the spiral arms, which if present, is relatively weak at that our signal-to-noise ratio was good enough to put a lower detection limit of any modulated emission at 5--6%. Only in one arm of the HeII 4686A line, is there a possibility of modulated emission, but again, we cannot be sure this is not caused by blending with the nearby Bowen complex of lines.Comment: 20 pages, 8 figures, submitted to Journal of Astronomical Dat

Hybrid microfibers based on polylactic acid/hydroxypropyl-methyl-cellulose loaded with curcumin

En aquest estudi s'ha preparat una matriu polimèrica basada en microfibres obtingudes mitjançant la tècnica d'electrospinning. Les microfibres es caracteritzen per la composició d'àcid polilàctic (PLA, polímer hidròfob) i hidroxipropilmetilcel·lulosa (HPMC, polímer hidròfil). Així, podem caracteritzar les fibres com una barreja híbrida de PLA i HPMC. Aquestes fibres es van carregar amb curcumina, una molècula activa amb propietats antitumorals i antibacterianes i naturalesa hidrofòbica. Per a l'obtenció de les matrius es va estudiar la solubilitat dels polímers i establir els dissolvents compatibles per a l'optimització del procés d'electrospinning. Les diferents matrius preparades es van caracteritzar per la morfologia de les fibres que les componen. Finalment, es duu a terme l’estudi de l’alliberament de curcumina a partir de les matrius de fibres. El caràcter dual (hidròfob/hidròfil) de les microfibres de PLA/HPMC permet la càrrega de qualsevol fàrmac, amb la garantia de la seva compatibilitat i distribució uniforme a les fibres, per la qual cosa es podria considerar com un sistema general d'alliberament de fàrmacs.En este estudio se ha preparado una matriz polimérica basada en microfibras obtenidas mediante la técnica de electrospinning. Las microfibras se caracterizan por su composición de ácido poliláctico (PLA, polímero hidrófobo) e hidroxipropilmetilcelulosa (HPMC, polímero hidrófilo). Así, podemos caracterizar las fibras como una mezcla híbrida de PLA y HPMC. Estas fibras se cargaron con curcumina, una molécula activa con propiedades antitumorales y antibacterianas y naturaleza hidrofóbica. Para la obtención de las matrices se procedió a estudiar la solubilidad de los polímeros y establecer los disolventes compatibles para la optimización del proceso de electrospinning. Las diferentes matrices preparadas se caracterizaron por la morfología de las fibras que las componen. Por último, se lleva a cabo el estudio de la liberación de curcumina a partir de las matrices de fibras. El carácter dual (hidrófobo/hidrófilo) de las microfibras de PLA/HPMC permite la carga de cualquier fármaco, con la garantía de su compatibilidad y distribución uniforme en las fibras, por lo que podría considerarse como un sistema general de liberación de fármacos.In this study, a polymer matrix based on microfibers obtained by the electrospinning technique has been prepared. Microfibers are characterized by their composition of polylactic acid (PLA, hydrophobic polymer) and hydroxypropyl-methyl-cellulose (HPMC, hydrophilic polymer). Thus, we can characterize the fibers as a hybrid blend of PLA and HPMC. These fibers were loaded with curcumin, an active molecule with antitumor and antibacterial properties and hydrophobic nature. To obtain the matrices, we proceed to study the solubility of the polymers and establish the compatible solvents for the optimization of the electrospinning process. The different matrices prepared were characterized by the morphology of their constituent fibers. Finally, the curcumin release from the fiber matrices is studied. The dual character (hydrophobic/hydrophilic) of PLA/HPMC microfibers allows the loading of any drug, with the assurance of its compatibility and uniform distribution in the fibers, and therefore this could be considered as a general drug delivery system.Incomin

Information and Communication technologies as agricultural extension tools

Knowledge and innovation society are becoming priorities to the welfare and quality of life of the rural population. This is based substantially on scientific and technological progress. Information and Communication Technologies (ICTs) accelerate rural development by contributing to more efficient management and rapid knowledge dissemination. ICTs are defined as a different set of technological tools and resources used for communication and for the creation, processing, dissemination, storage and information management. The rapid revolution in modern agriculture has led to investigations in many regions. One of them is the rural region of the prefecture of Pella that exists many years in the agricultural sector. The objective of this research is to evaluate the adoption of ICTs among farmers and determine the importance of agricultural extension as an information source in the region of Central Macedonia. For this purpose, the approaches of summary statistics in combination with multivariate statistical analysis techniques have been used. In particular, through the statistical package SPSS (v.16.0), there were employed two correlation methods: (a) the categorical regression model and (b) the two-step clustering. The primary research data were collected using a specifically constructed questionnaire, supplemented by personal interviews with farmers of the prefecture of Pella. The sampling result was to collect a general sample of 303 valid questionnaires.Categorical Regression, Central Macedonia, Information and Communication Technologies, Rural development, Two-step clustering

CLASSIFYING AND RESPONDING TO NETWORK INTRUSIONS

Intrusion detection systems (IDS) have been widely adopted within the IT community, as passive monitoring tools that report security related problems to system administrators. However, the increasing number and evolving complexity of attacks, along with the growth and complexity of networking infrastructures, has led to overwhelming numbers of IDS alerts, which allow significantly smaller timeframe for a human to respond. The need for automated response is therefore very much evident. However, the adoption of such approaches has been constrained by practical limitations and administrators' consequent mistrust of systems' abilities to issue appropriate responses. The thesis presents a thorough analysis of the problem of intrusions, and identifies false alarms as the main obstacle to the adoption of automated response. A critical examination of existing automated response systems is provided, along with a discussion of why a new solution is needed. The thesis determines that, while the detection capabilities remain imperfect, the problem of false alarms cannot be eliminated. Automated response technology must take this into account, and instead focus upon avoiding the disruption of legitimate users and services in such scenarios. The overall aim of the research has therefore been to enhance the automated response process, by considering the context of an attack, and investigate and evaluate a means of making intelligent response decisions. The realisation of this objective has included the formulation of a response-oriented taxonomy of intrusions, which is used as a basis to systematically study intrusions and understand the threats detected by an IDS. From this foundation, a novel Flexible Automated and Intelligent Responder (FAIR) architecture has been designed, as the basis from which flexible and escalating levels of response are offered, according to the context of an attack. The thesis describes the design and operation of the architecture, focusing upon the contextual factors influencing the response process, and the way they are measured and assessed to formulate response decisions. The architecture is underpinned by the use of response policies which provide a means to reflect the changing needs and characteristics of organisations. The main concepts of the new architecture were validated via a proof-of-concept prototype system. A series of test scenarios were used to demonstrate how the context of an attack can influence the response decisions, and how the response policies can be customised and used to enable intelligent decisions. This helped to prove that the concept of flexible automated response is indeed viable, and that the research has provided a suitable contribution to knowledge in this important domain

The importance of uncoupling troponin I phosphorylation from Ca2+ sensitivity in the pathogenesis of cardiomyopathy

Heart muscle contraction is regulated via the β adrenergic response that results to phosphorylation of Protein Kinase A (PKA), which in turn decreases the Ca2+ sensitivity of the cardiac myofilament, which is very important for the heart muscle to relax. Mutations in the thin filament that cause Dilated Cardiomyopathy (DCM) and some that cause Hypertrophic Cardiomyopathy (HCM) abolish this relationship, so that the Ca2+ sensitivity becomes independent of Troponin I (TnI) phosphorylation (uncoupling). The aim of the thesis is to unravel the molecular mechanism of the uncoupling phenomenon. It is known that there is a specific interaction between the phosphorylatable TnI N terminal peptide and the Ca2+ binding site on TnC, that is weakened by phosphorylation and we hypothesize that it is disrupted in case of a DCM or HCM mutation, giving rise to the uncoupling phenomenon. Ca2+ sensitisers and desensitisers change the Ca2+ sensitivity of the cardiac muscle like mutations do but their relationship with TnI phosphorylation has never been studied before. Using the in vitro motility assay I showed that the Ca2+ sensitisers EMD 57033 and Bepridil increased the Ca2+ sensitivity of donor thin filaments and additionally they uncoupled the Ca2+ sensitivity from the TnI phosphorylation. Epigallocatechin-3-gallate (EGCG) decreased the Ca2+ sensitivity of donor thin filaments whilst retaining the coupling. On the other hand, EGCG reduced the Ca2+ sensitivity of phosphorylated but not dephosphorylated mutant thin filaments restoring the Ca2+ sensitivity change to TnI phosphorylation. EGCG re-coupled 5 DCM (TPM1 E54K and E40K, TNNI3 K36Q, TNNC1 G159D, ACTC E361G) mutants and 3 HCM (TPM1 E180G, TNNT2 K280N, ACTC E99K) mutants which were originally uncoupled. We were given 30 analogue compounds structurally similar to EGCG and nine of them were able to re-couple uncoupled TPM1 E180G HCM mutant thin filaments. The working compounds re-coupled DCM mutation TPM1 E54K and HCM mutation ACTC E99K. I show for the first time that it is possible to mimic and reverse the effect of DCM and HCM mutations on troponin pharmacologically. EGCG and its analogue compounds might have significant implications for the effective treatment of thin filament cardiomyopathies that uncouple the Ca2+ sensitivity from TnI phosphorylation. In a separate study I investigated 11 mutations in skeletal muscle tropomyosin associated with various myopathies. I found that 7 mutations cause a gain of function that could be accounted for at the molecular level due to destabilising specific actin-tropomyosin interactions. Gain of function at the molecular level correlates with a hypercontractile phenotype in patients.Open Acces

Detection of minimal residual disease in Acute Myeloid Leukemia with t(8;21) translocation

Acute myeloid leukemia (AML) with t(8;21) rearrangement, constitutes about 5% of all AML cases and is characterized by the presence of RUNX1-RUNX1T1 fusion gene. Although this subtype, referred as CBF leukemia, belongs to the favorable cytogenetic risk group, 25% to 30% of the patients relapse. Detection of minimal residual disease (MRD) is of major importance since it evaluates the “depth” of the remission and therefore, risk adapted therapy based on early detection of relapse becomes feasible. RUNX1-RUNX1T1 fusion gene could be used for MRD detection using RQ-PCR. Within this work, a sensitive, specific and easy to perform, calibrator normalized relative quantification with external standards assay for RUNX1-RUNX1T1 transcript levels, was established and has consequently been integrated in the routine diagnostic work-up of RUNX1-RUNX1T1 positive patients. ABL1 was used as a reference gene and cDNA of the Kasumi-1 cell line as a calibrator. Relative quantification was performed by calculating the RUNX1-RUNX1T1/ ABL1 ratio, which was further normalized to the RUNX1-RUNX1T1/ABL1 expression ratio of Kasumi-1 calibrator. Maximum sensitivity of the assays for both target and reference gene, was higher than 10-4 (5x10-4). The sensitivity of 5x10-4 was also confirmed using cDNA dilutions from Kasumi-1 cell line as well as dilutions of patients’ cDNA. The specificity of the assay was determined when RUNX1-RUNX1T1 negative patients were tested; along with cDNA from negative cell lines and no amplification was observed. 184 samples from 39 patients, were quantified in order to assess the clinical usefulness of the assay. Transcript levels in 12 patients were measured on day 16 and were correlated to the clinical outcome. Moreover in 20 patients, comparison of the RUNX1-RUNX1T1 ratios at diagnosis and before consolidation revealed a 3 log10 decrease, which was also correlated to the disease outcome. 28% (11/39) of the patients in the study relapsed, consistent with previous studies. Very importantly, due to the good correlation of RUNX1-RUNX1T1 transcripts with the disease course, this assay will also be used to monitor MRD of t(8;21) positive patients within the recently launched AMLCG2014 study

Mapping out different discourses of mathematical horizon

‘Knowledge at the mathematical horizon’ refers to a particular domain of teachers’ knowledge related to connections across mathematics. This construct has been used and elaborated in research. Nonetheless, ‘knowledge at the mathematical horizon’ is still considered a ‘grey area’ with different interpretations and meanings. In this paper, I report a preliminary commognitive analysis of a sample of papers about knowledge at the mathematical horizon attending to the use of the term in the related research. The aim of this paper is to investigate different narratives in relation to the construct and how these narratives might be linked to how knowledge at the mathematical horizon is conceptualised and operationalised into research. To conclude, I argue that a discursive approach might provide better insight about the nature and use of mathematical horizon in research and set the scene for further development of these ideas as part of mathematics teachers’ discourses