180 research outputs found

    Information Systems Undergraduate Degree Project: Gaining a Better Understanding of the Final Year Project Module

    Get PDF
    The place of an individual project in the final year of Information Systems (IS) undergraduate degrees at UK universities is well established. In this paper we compare the final year project modules at four UK universities: the University of Brighton, the University of South Wales, University of West London and the University of Westminster. We find that the aims of the projects are similar, emphasising the application of the knowledge and skills from the taught element of their course in a complex development project, often including interactions with a real client. Although we show in this analysis that projects serve a similar purpose in the IS degree courses, the associated learning outcomes and the assessment practice varies across the institutions. We identify some gaps in the skills and abilities that are not being assessed. In further work we are planning to consult final year students undertaking their projects and their supervisors, in order to gain an understanding of how project assessment criteria are actually put to use

    The prolate-to-oblate shape transition of phospholipid vesicles in response to frequency variation of an AC electric field can be explained by the dielectric anisotropy of a phospholipid bilayer

    Full text link
    The external electric field deforms flaccid phospholipid vesicles into spheroidal bodies, with the rotational axis aligned with its direction. Deformation is frequency dependent: in the low frequency range (~ 1 kHz), the deformation is typically prolate, while increasing the frequency to the 10 kHz range changes the deformation to oblate. We attempt to explain this behaviour with a theoretical model, based on the minimization of the total free energy of the vesicle. The energy terms taken into account include the membrane bending energy and the energy of the electric field. The latter is calculated from the electric field via the Maxwell stress tensor, where the membrane is modelled as anisotropic lossy dielectric. Vesicle deformation in response to varying frequency is calculated numerically. Using a series expansion, we also derive a simplified expression for the deformation, which retains the frequency dependence of the exact expression and may provide a better substitute for the series expansion used by Winterhalter and Helfrich, which was found to be valid only in the limit of low frequencies. The model with the anisotropic membrane permittivity imposes two constraints on the values of material constants: tangential component of dielectric permittivity tensor of the phospholipid membrane must exceed its radial component by approximately a factor of 3; and the membrane conductivity has to be relatively high, approximately one tenth of the conductivity of the external aqueous medium.Comment: 17 pages, 6 figures; accepted for publication in J. Phys.: Condens. Matte

    Efficient Synthesis of Fluorescent Coumarins and Phosphorous-Containing Coumarin-Type Heterocycles via Palladium Catalyzed Cross-Coupling Reactions

    Get PDF
    Quantum-chemical calculations on the spectral properties of some aryl substituted 3- phosphonocoumarins were performed, and the effect of the substituents in the aryl moiety was evaluated. The structures possessing promising fluorescent properties were successfully synthesized via Suzuki and Sonogashira cross-coupling. The synthetic protocol was also applied for the phosphorous chemoisomer of 3-phosphonocoumarin, 1,2-benzoxaphosphorin, and their carboxylate analogues. The optical properties of the arylated and alkynylated products were experimentally determined. The obtained quantum-chemical and experimental results give the possibility for a fine tuning of the optical properties of phosphorous-containing coumarin systems by altering the substituent at its C-6 position

    Turismo y crisis: el comportamiento del inmobiliario turístico en la montaña española durante la última década. Estudio de casos: la Val d’Aran y Sierra Nevada

    Get PDF
    En esta comunicación se analiza, como respuesta al enunciado del título, la evolución reciente del parque de viviendas que puede estar vinculado a una función turístico-residencial. Se pretende valorar, a partir de los resultados, el papel que desempeña esta función en el proceso de dinamización local y de renovación de la montaña española como escenario turístico y detectar, asimismo, otros posibles fundamentos de dicha renovación. Se analizan específicamente los datos de los censos de vivienda y las estadísticas de viviendas construidas en destinos significativos previamente seleccionados. El estudio se centra en los últimos quince años, y se realiza a escala municipal. La comarca y el municipio constituyen unidades espaciales operativas idóneas a efectos del tratamiento estadístico de la información obtenida

    Comparative analysis of main clinical features in melanoma patients with and without sentinel lymph node biopsy

    Get PDF
    Introduction. Sentinel lymph node biopsy is fundamental in the treatment and prognosis of cutaneous malignant melanoma. This study aims to identify differences in baseline clinical characteristics and survival of patients with melanoma with and without a sentinel lymph node biopsy (SLNB) performed.  Material and methods. In 2018, a retrospective study of 151 patients with malignant melanoma (MM) was conducted. The patients were hospitalized at the Second Clinic of University Hospital — Pleven, from 2012 to 2017. The patients were divided into two groups: Group A included 58 (38.4%) patients with SLNB performed; Group B included 93 (61.6%) patients who did not undergo SLNB. A double-detection method was used while performing SLNB.  Results. The incidence of achromatic malignant melanoma is significantly higher in patients without SLNB (12 or 12.9%) than in patients with SLNB (2 or 3.4%) — c2 = 3.796, df = 1, p = 0.051. Of all 151 patients in the study, 46 died, representing 30.5% of patients with melanoma. The mortality rate was higher in the patients without SLNB (32.3% vs. 27.6% in Group A). However, the differences in the two groups are not statistically significant.  Conclusions. Patients with achromatic melanoma have significantly fewer sentinel lymph node (SLN) biopsies performed because of a late diagnosis. Most of our patients are diagnosed at a later stage when lymphatic metastases are already present, which leads to a significant increase in lymph node dissections performed. There is no significant difference in mortality and survival in the SLNB and non-SLNB groups

    Global Gene Expression Associated with Hepatocarcinogenesis in Adult Male Mice Induced by in Utero Arsenic Exposure

    Get PDF
    Our previous work has shown that exposure to inorganic arsenic in utero produces hepatocellular carcinoma (HCC) in adult male mice. To explore further the molecular mechanisms of transplacental arsenic hepatocarcinogenesis, we conducted a second arsenic transplacental carcinogenesis study and used a genomewide microarray to profile arsenic-induced aberrant gene expression more extensively. Briefly, pregnant C3H mice were given drinking water containing 85 ppm arsenic as sodium arsenite or unaltered water from days 8 to 18 of gestation. The incidence of HCC in adult male offspring was increased 4-fold and tumor multiplicity 3-fold after transplacental arsenic exposure. Samples of normal liver and liver tumors were taken at autopsy for genomic analysis. Arsenic exposure in utero resulted in significant alterations (p < 0.001) in the expression of 2,010 genes in arsenic-exposed liver samples and in the expression of 2,540 genes in arsenic-induced HCC. Ingenuity Pathway Analysis revealed that significant alterations in gene expression occurred in a number of biological networks, and Myc plays a critical role in one of the primary networks. Real-time reverse transcriptase–polymerase chain reaction and Western blot analysis of selected genes/proteins showed > 90% concordance. Arsenic-altered gene expression included activation of oncogenes and HCC biomarkers, and increased expression of cell proliferation–related genes, stress proteins, and insulin-like growth factors and genes involved in cell–cell communications. Liver feminization was evidenced by increased expression of estrogen-linked genes and altered expression of genes that encode gender-related metabolic enzymes. These novel findings are in agreement with the biology and histology of arsenic-induced HCC, thereby indicating that multiple genetic events are associated with transplacental arsenic hepatocarcinogenesis

    Effect of cytisine on some brain and hepatic biochemical parameters in spontaneously hypertensive rats

    Get PDF
    Tobacco smoking is a risk factor for variety of cardio-vascular diseases, such as hypertension, myocardial infarction, stroke and many others. It is of great importance for hypertensive patients to stop smoking. One of the medicines widely used for smoking cessation in Bulgaria is the original Bulgarian product Tabex®, which is developed on the basis of natural plant alkaloid cytisine. The aim of the following study was to ivestigate the effects of cytisine on some brain and hepatic biochemical parameters in spontaneously hypertensive rats (SHR), an widely used rodent model for human essential hypertension, and to compare the obtained results with their age-matched normotensive controls Wistar Kyoto (WKY). Multiple cytisine administration did not affect the activity of ethylmorphine-N-demethylase (EMND) and anylinehydroxylase (AH), as well as the quantity of cytochrome P 450, nor in WKY neither in SHR In the liver cytisine increased the MDA quantity both in SHR and in WKY, by 25% (p<0.05) and by 29% (p<0.05) respectively, while the GSH level was not significantly changed by the compound in both strains. In contrast, on the brain level, cytisine administration to SHR caused more prominent toxicity, resulted in GSH depletion and increased MDA quantity, while in WKY strain did not exert any toxicity. Cytisine did not significantly affect ALAT and ASAT activity in both strains. In conclusion, the results of our study suggest higher brain toxicity of cytisine in spontaneously hypertensive rats, that might be due to their pathophysiological characteristics
    corecore