110 research outputs found

    An investigation into the history of the airbrush and the impact of the conservation treatment of airbrushed canvas paintings

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    The research considers whether traditional approaches to easel paintings conservation are appropriate for the treatment of air brush paintings. The objectives were: -To investigate the aesthetic and technical history of the airbrush -To investigate surface changes in paint layers -To investigate the appropriateness of traditional conservation treatments for airbrush paintings and evaluate alternative approaches Although the first airbrush was introduced in 1883 it was initially rejected by many fine art circles as being too ‘mechanical’. Airbrush techniques have been little discussed in the field of fine art and the field of the conservation of fine art. A mixed methodology was followed for this research, qualitative through literature review carried out in line with the interdisciplinary nature of the research, and quantitative through various approaches including surveys. One survey was carried out in order to establish the use of air brush techniques by artists and its eventual acceptance as a fine art technique. A second survey was conducted to discover how well conservators understood the degradation characteristics of air brush paintings and their appropriate treatment. The research revealed that much of the eventual success of air brush painting resulted from the introduction of new types of paint in order to better manage the technique. It also revealed that there was a high level of uncertainty amongst practitioners in the field of paintings conservation with regard to the deterioration characteristics of air brush painting or their appropriate resolution. However the major concern with regard to conservation lay clearly within the field of image re-integration as a result of its characteristically smooth surface finish. Artificial light ageing was carried out on simulated mock ups in order to develop a clearer understanding of the type of surface changes that might be expected over time from a limited palette of colours. This was followed by technical visual examination and media analysis via FTIR and Py- GC-MS methods. It was found that there were changes in surface morphology in some colours, which appeared to further enhance the smooth surface finish of the paint layer. A range of approaches to image re-integration were trialled ranging from the traditional paint based approaches to the use of digital coloured light. The latter was of particular interest in offering a truly reversible none interventive approach to re-integration. The focus of the digital re-integration techniques was to evaluate the viability of its use in general practice. Due to the smooth surface as well as the build-up of multiple layers of colour the traditional approaches proved difficult to harmonise within the picture plain. The use of digital approaches using coloured light was more successful although further research is required in order to develop this approach for wide spread professional practice. The physical and chemical characteristics of the airbrushed paint layer present issues that are fundamentally different to those found in oil paintings. As yet these are not all fully understood and require further research. Until such time the use of none interventive, reversible image re-integration techniques such as coloured light would be recommended

    A scalable optoelectronic neural probe architecture with self-diagnostic capability

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    There is a growing demand for the development of new types of implantable optoelectronics to support both basic neuroscience and optogenetic treatments for neurological disorders. Target specification requirements include multi-site optical stimulation, programmable radiance profile, safe operation, and miniaturization. It is also preferable to have a simple serial interface rather than large numbers of control lines. This paper demonstrates an optrode structure comprising of a standard complementary metal-oxide-semiconductor process with 18 optical stimulation drivers. Furthermore, diagnostic sensing circuitry is incorporated to determine the long-term functionality of the photonic elements. A digital control system is incorporated to allow independent multisite control and serial communication with external control units

    Trends of Zambia’s tuberculosis burden over the past two decades

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    Objectives:  To study trends in Zambia’s TB notification rates between 1990 and 2010 and to ascertain progress made towards TB control. Methods:  Retrospective review of TB notification returns and TB programme reports for the period from 1990 to 2010. Results:  Two distinct TB trend periods were identified: a period of rising trends up to a peak between 1990 and 2004 and a period of moderately declining trends between 2004 and 2010. Treatment outcomes improved over the two decades. Data on trends in paediatric TB, TB in prisoners and TB in pregnant women remain scanty and unreliable owing to poor diagnostic capability. There were no data available on trends on drug-resistant TB because of the lack of laboratory services to perform drug sensitivity testing. Conclusions:  The period of increasing TB between 1990 and 2000 coincided with an increase in HIV/AIDS. The period of slightly decreasing TB between 2004 and 2010 can be attributed to improved TB care, sustained DOTS implementation and improvement in TB diagnostic services. Newer diagnostics technologies for the rapid diagnosis of active TB cases and for drug-resistant testing, recently endorsed by the WHO, need to be implemented into the national TB programmes to detect more cases and to provide epidemiological and surveillance data from which to obtain an evidence base for guided investments for TB control. Alignment of TB and HIV services is required to achieve improved management outcomes

    The Impact of National Private Investment on Manufacturing in Egypt

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    This paper aims to present national private investment development phases and its contribution in manufacturing sector in Egypt. Moreover it devoted to examine the effect of national private investment on Egyptian manufacturing. Vector Auto Regressive analysis (VAR) was adopted based on yearly data for the period (1990-2015). Time series stationarity are checked by Augmented Dicky Fuller (ADF) test, and co- integration existence tested by Johansen co- integration test. The vector Error Correction model (VECM) utilized to check the existence of long run relationship between the manufactured product as a dependent variable and the national private investment as explanatory variable. Finally this paper concluded that, however national private investment contribute high share to manufacturing sector, the empirical analysis results obtained negative impact of this type of investment on manufacturing sector in short and long run. Keywords: national private investment, manufactured product, vector error correction model. JEL Classifications: E22, C22, L60, N6

    Comparison between different optical systems for optogenetics based head mounted device for retina pigmentosa

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    Optogenetics is a fast growing neuromodulation techniques as it can remotely stimulate neural activities of a genetically modified cells. The advantage of remotely controlling the neural activity triggered researchers to implement a headset to externally stimulate retina cells for people with retina pigmentosa. The wearable device requires an efficient optical system to focus the transmitted light pattern into the retina surface. In this work, three different lenses; contact lens, folded prism and linear lenses are used to evaluate the headset performance. A 90x90 μLED display is used as a light source and the optical efficiency for each lens is measured for different points over the lens area. Moreover, the impact of each lens on the headset performance in power and processing will be discussed in this work

    In-vitro evaluation of selected Egyptian traditional herbal medicines for treatment of Alzheimer disease

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    BACKGROUND: Egyptians recognized the healing power of herbs and used them in their medicinal formulations. Nowadays, “Attarin” drug shops and the public use mainly the Unani medicinal system for treatment of their health problems including improvement of memory and old age related diseases. Numerous medicinal plants have been described in old literature of Arabic traditional medicine for treatment of Alzheimer’s disease (AD) (or to strengthen memory). METHODS: In this study, some of these plants were evaluated against three different preliminary bioassays related to AD to explore the possible way of their bio-interaction. Twenty three selected plants were extracted with methanol and screened in vitro against acetylcholinesterase (AChE) and cycloxygenase-1 (COX-1) enzymes. In addition, anti-oxidant activity using DPPH was determined. RESULTS: Of the tested plant extracts; Adhatoda vasica and Peganum harmala showed inhibitory effect on AChE at IC50 294 μg/ml and 68 μg/ml respectively. Moreover, A. vasica interacted reversibly with the enzyme while P. harmala showed irreversible inhibition. Ferula assafoetida (IC50 3.2 μg/ml), Syzygium aromaticum (34.9 μg/ml) and Zingiber officinalis (33.6 μg/ml) showed activity against COX-1 enzyme. Potent radical scavenging activity was demonstrated by three plant extracts Terminalia chebula (EC50 2.2 μg/ml), T. arjuna (3.1 μg/ml) and Emblica officinalis (6.3 μg/ml). CONCLUSION: Interestingly, differential results have been obtained which indicate the variability of the mode of actions for the selected plants. Additionally, the reversible interaction of A. vasica against AChE and the potent activity of F. assafoetida against COX-1 make them effective, new and promising agents for treatment of AD in the future, either as total extracts or their single bioactive constituents.Science and Technology Development Fund (STDF), Egypt (project number 251)http://www.biomedcentral.com/1472-6882/13/121am2014mn201

    Development of new thiazolidine-2,4-dione hybrids as aldose reductase inhibitors endowed with antihyperglycaemic activity: design, synthesis, biological investigations, and in silico insights

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    This research study describes the development of new small molecules based on 2,4-thiazolidinedione (2,4-TZD) and their aldose reductase (AR) inhibitory activities. The synthesis of 17 new derivatives of 2,4-TZDs hybrids was feasible by incorporating two known bioactive scaffolds, benzothiazole heterocycle, and nitro phenacyl moiety. The most active hybrid (8b) was found to inhibit AR in a non-competitive manner (0.16 µM), as confirmed by kinetic studies and molecular docking simulations. Furthermore, the in vivo experiments demonstrated that compound 8b had a significant hypoglycaemic effect in mice with hyperglycaemia induced by streptozotocin. Fifty milligrams per kilogram dose of 8b produced a marked decrease in blood glucose concentration, and a lower dose of 5 mg/kg demonstrated a noticeable antihyperglycaemic effect. These outcomes suggested that compound 8b may be used as a promising therapeutic agent for the treatment of diabetic complications

    Self-Assembled Lipoplexes of Short Interfering RNA (siRNA) Using Spermine-Based Fatty Acid Amide Guanidines: Effect on Gene Silencing Efficiency

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    Four guanidine derivatives of N4,N9-diacylated spermine have been designed, synthesized, and characterized. These guanidine-containing cationic lipids bound siRNA and formed nanoparticles. Two cationic lipids with C18 unsaturated chains, N1,N12-diamidino-N4,N9-dioleoylspermine and N1,N12-diamidino-N4-linoleoyl-N9-oleoylspermine, were more efficient in terms of GFP expression reduction compared to the other cationic lipids with shorter C12 (12:0) and very long C22 (22:1) chains. N1,N12-Diamidino-N4-linoleoyl-N9-oleoylspermine siRNA lipoplexes resulted in GFP reduction (26%) in the presence of serum, and cell viability (64%). These data are comparable to those obtained with TransIT TKO. Thus, cationic lipid guanidines based on N4,N9-diacylated spermines are good candidates for non-viral delivery of siRNA to HeLa cells using self-assembled lipoplexes

    Nutritive Value of Ajuga iva as a Pastoral Plant for Ruminants: Plant Phytochemicals and In Vitro Gas Production and Digestibility

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    This study aims to evaluate the nutritive value of Ajuga iva (A. iva) harvested from three distinct altitude regions in Tunisia (Dougga, Mograne, and Nabeul). The chemical composition, phenolic concentration, gas production, and in vitro dry matter (DM) digestibility were determined. The highest concentrations of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were for A. iva cultivated in Nabeul. In contrast, the highest crude protein (CP) concentration was observed in that cultivated in Mograne, and the lowest (p < 0.01) CP concentration was noted in that cultivated in Dougga. Additionally, the cultivation regions affected the concentrations of free-radical scavenging activity, total flavonoids, and total polyphenols (p < 0.01). The highest free-radical scavenging activity was observed with A. iva cultivated in Dougga and Mograne. The highest (p < 0.05) gas production rate and lag time were observed in A. iva cultivated in Mograne and Nabeul regions. DM digestibility differed between regions and methods of determination. The highest (p < 0.01) DM degradability, determined by the method of Tilley and Terry and the method of Van Soest et al., was for A. iva cultivated in Mograne and Dougga, while the lowest (p < 0.01) value was recorded for that cultivated in the Nabeul region. Likewise, metabolizable energy (ME) and protein digestibility values were higher for A. iva collected from Mograne region than that collected from the other sampling areas. In conclusion, the nutritive value of A. iva differed between regions. Therefore, care should be taken when developing recommendations for using A. iva in an entire region. Season- and region-specific feeding strategies for feeding A. iva are recommended
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