Enhancing infrared emission of mercury telluride (HgTe) quantum dots by plasmonic structures

The coupling of HgTe quantum dots to a gold nanobump plasmonic array can enhance the spontaneous infrared emission by a factor of five and reduce the influence of nonradiative decay channels

The Study of Job Satisfaction of Employment Guidance Teachers in Heilongjiang International University in China

In recent years, the employment guidance teachers in private colleges and universities in China have grown rapidly. Whether they can be attracted and retained, and whether stimulate their work vitality, job satisfaction is an important indicator. The study found that the overall job satisfaction of employment guidance teachers is low and their turnover intention is high. This article investigated the job satisfaction of employment guidance teachers in Heilongjiang International University (HIU), using a quantitative questionnaire. According to the survey results of 200 respondents, various influencing factors are found, and the factors affecting the job satisfaction of employment guidance teachers are determined. Multiple regression analysis was used in this study. The results show that work load, work salary, interpersonal relationship and position promotion have a significant impact on job satisfaction

Exploring HIV Integrase 3’-processing Using Designed DNA Substrates and Structural Study of HIV DNA Hairpins

In the HIV viral integration procedure, 3’-processing of the viral DNA by the integrase enzyme is an essential first step which is followed by the integration of viral DNA into the host genome. In 3’-processing, the integrase cleaves the backbone of the DNA substrate on the 3’ end of a conserved CA dinucleotide motif and inserts a helix between the two DNA strands, forcing them apart (Hare, S., 2012). Our study confirms that the presence of a G-amino group is crucial for 3’-processing. Substituting inosine for G in the CA step removes this amino group and results in loss of enzyme activity. Further work showed that the presence of a terminal duplex segment is not required for 3’-processing. Additional substrate modifications are studied in order to evaluate the actual importance of the CA step

Investigation of Non-coherent Discrete Target Range Estimation Techniques for High-precision Location

Ranging is an essential and crucial task for radar systems. How to solve the range-detection problem effectively and precisely is massively important. Meanwhile, unambiguity and high resolution are the points of interest as well. Coherent and non-coherent techniques can be applied to achieve range estimation, and both of them have advantages and disadvantages. Coherent estimates offer higher precision but are more vulnerable to noise and clutter and phase wrap errors, particularly in a complex or harsh environment, while the non-coherent approaches are simpler but provide lower precision. With the purpose of mitigating inaccuracy and perturbation in range estimation, miscellaneous techniques are employed to achieve optimally precise detection. Numerous elegant processing solutions stemming from non-coherent estimate are now introduced into the coherent realm, and vice versa. This thesis describes two non-coherent ranging estimate techniques with novel algorithms to mitigate the instinct deficit of non-coherent ranging approaches. One technique is based on peak detection and realised by Kth-order Polynomial Interpolation, while another is based on Z-transform and realised by Most-likelihood Chirp Z-transform. A two-stage approach for the fine ranging estimate is applied to the Discrete Fourier transform domain of both algorithms. An N-point Discrete Fourier transform is implemented to attain a coarse estimation; an accurate process around the point of interest determined in the first stage is conducted. For KPI technique, it interpolates around the peak of Discrete Fourier transform profiles of the chirp signal to achieve accurate interpolation and optimum precision. For Most-likelihood Chirp Z-transform technique, the Chirp Z-transform accurately implements the periodogram where only a narrow band spectrum is processed. Furthermore, the concept of most-likelihood estimator is introduced to combine with Chirp Z-transform to acquire better ranging performance. Cramer-Rao lower bound is presented to evaluate the performance of these two techniques from the perspective of statistical signal processing. Mathematical derivation, simulation modelling, theoretical analysis and experimental validation are conducted to assess technique performance. Further research will be pushed forward to algorithm optimisation and system development of a location system using non-coherent techniques and make a comparison to a coherent approach

Mass spectrometric investigation of biomedically important glycosylation

Glycobiology is the comprehensive study of the structure, biosynthesis, function and evolution of saccharides which are also named sugars or glycans. Glycosylation is a type of modification in which sugars are added to another molecule, such as a protein molecule or a ceramide. Abnormal glycosylation is frequently associated with diseases such as cancer and immune responses. Defining glycan structures is therefore important for understanding glycan function in health and disease. In addition, identification of glycan populations can provide essential information for further research on glycoproteins and glycolipids. In this thesis, glycomic experimental approaches were employed to characterize the structures and populations of glycans of glycoconjugates from HeLa cells, normal human dermal fibroblast (NHDF) cells, myoblasts, myotubes and trophoblasts. These approaches include sample preparation methodologies which were followed by the application of highly sensitive mass spectrometry, particularly MALDI-TOF MS, MALDI-TOF/TOF MS/MS and GC-MS. Ribosome inactivating proteins (RIPs) and lectins from elderberry are more toxic to HeLa cells than to NHDF cells. The difference in the cytotoxicity was hypothesized to be caused by the difference in the glycome patterns of HeLa and NHDF cells. To test the hypothesis, glycome patterns on both glycoproteins and glycolipids of HeLa and NHDF cells were investigated. Glycomic results have revealed that glycome patterns in HeLa cells and NHDF are different, and this gives a possible explanation for the difference observed in the cytotoxicity assay. Glutamine-fructose-6-phosphate transaminase 1 (GFPT1) is the first enzyme of the hexosamine biosynthetic pathway which yields uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), an essential substrate for protein glycosylation. N-glycan branching is especially sensitive to alterations in the concentration of this sugar nucleotide. Mutations in the gene GFPT1 can result in “limb-girdle CMS with tubular aggregates” which is a subtype of congenital myasthenic syndromes (CMS). To investigate whether protein glycosylation at the neuromuscular junction might be involved in this impairment, the N-glycomes of myoblasts and myotubes derived from healthy controls and patients were investigated. My result showed that global glycosylation is not significantly impaired in the muscle cells from the CMS patients caused by GFPT1 mutations. The human fetoembryonic defense system hypothesis (hu-FEDS) is a hypothetical model depicting a way via which the human immune system is able to recognize foreign substances as "own species" as has been observed with maternal immune tolerance in pregnancy. The fundamental idea of this hypothesis is that glycoproteins existing in the reproductive system and exposed on gametes can either inhibit immune responses or prevent rejection of the foetus. This model has not been tested in human trophoblasts. My glycomic analyses of three trophoblast populations (CTB, STB and evCTB) revealed that functional glycan structures that are present on human gametes are also expressed on trophoblasts, and this provides further evidence for the hu-FEDS hypothesis.Open Acces

The Relationship Between Timber Chemical Compositions and Mechanical Properties

Timber is widely used both in modern and historic construction, with ageing being the most serious risk in the structural mechanical strength. A non-destructive test to predict timber mechanical properties is urgently needed and many studies indicated that chemical compositions have close relationships to the mechanical properties. Hence, this study focusses on the relationships between timber chemical composition and the corresponding mechanical strength, providing contributions to the non-destructive testing of timber mechanical properties. Non-destructive testing has a wide prospect both in evaluation of modern timber construction and historic timber framed building conservation. Heat treatment is a method to cause changes in timber, whilst FTIR is the technique for analysing its chemical compositions. Static and dynamic mechanical properties were tested by a 3-point bending and a dynamic thermal mechanical analysis (DMTA) facility, respectively. The changes of timber mechanical properties are the results of various combined chemical compositions. In general, condensation and cross-linking reactions play an essential role in timber strength improvement. The static bending mechanical properties, modulus of rupture (MOR) and modulus of elasticity (MOE) increase, whilst in the dynamic mechanical properties and Tan δ decrease, which indicates an increase in elasticity and/or decrease of viscosity. Pyrolysis reactions in hemicellulose and lignin, lead to a decrease in the timber static mechanical properties and increase in Tan δ of the dynamic ones. Both static bending mechanical properties (MOR and MOE) and dynamic bending mechanical properties (storage modulus, loss modulus and Tan δ) can be predicted by the peak areas of the normalised FTIR spectrum. The coefficients of determination (R-square) of all the regression models are between 0.62 and 0.9, which indicates that the models are functional. In studies of timber accelerated ageing, the changes of each peak area during heat treatment are regressed by a model where temperature and treatment period as independent variables. The model shows that new pine can be treated in a two-steps heat treatment, which involves an air and a vacuum step to obtain similar chemical compositions of 580 years old real timber by heat treatment. The R-square of the model is more than 0.7 and thus, shows effective regression

Realizing Video Analytic Service in the Fog-Based Infrastructure-Less Environments

Deep learning has unleashed the great potential in many fields and now is the most significant facilitator for video analytics owing to its capability to providing more intelligent services in a complex scenario. Meanwhile, the emergence of fog computing has brought unprecedented opportunities to provision intelligence services in infrastructure-less environments like remote national parks and rural farms. However, most of the deep learning algorithms are computationally intensive and impossible to be executed in such environments due to the needed supports from the cloud. In this paper, we develop a video analytic framework, which is tailored particularly for the fog devices to realize video analytic service in a rapid manner. Also, the convolution neural networks are used as the core processing unit in the framework to facilitate the image analysing process

Demonstration of Semantic Web-based Medical Ontologies and Clinical Decision Support Systems

Master's thesis in Information- and communication technology IKT590 - University of Agder 2016Konfidensiell til / confidential until 01.01.202