Embedding based Link Prediction for Knowledge Graph Completion

This thesis proposes a novel Knowledge Graph (KG) embedding model for Link Prediction (LP) for Knowledge Graph Completion (KGC). The missing links in a KG are predicted based on the existing contextual information as well as textual entity descriptions. The model outperforms the state-of-the-art (SOTA) model DKRL for FB15k and FB15k-237 datasets

Entity Type Prediction in Knowledge Graphs using Embeddings

Open Knowledge Graphs (such as DBpedia, Wikidata, YAGO) have been recognized as the backbone of diverse applications in the field of data mining and information retrieval. Hence, the completeness and correctness of the Knowledge Graphs (KGs) are vital. Most of these KGs are mostly created either via an automated information extraction from Wikipedia snapshots or information accumulation provided by the users or using heuristics. However, it has been observed that the type information of these KGs is often noisy, incomplete, and incorrect. To deal with this problem a multi-label classification approach is proposed in this work for entity typing using KG embeddings. We compare our approach with the current state-of-the-art type prediction method and report on experiments with the KGs

Embedding Based Link Prediction for Knowledge Graph Completion

Knowledge Graphs (KGs) are the most widely used representation of structured information about a particular domain consisting of billions of facts in the form of entities (nodes) and relations (edges) between them. Besides, the KGs also encapsulate the semantic type information of the entities. The last two decades have witnessed a constant growth of KGs in various domains such as government, scholarly data, biomedical domains, etc. KGs have been used in Machine Learning based applications such as entity linking, question answering, recommender systems, etc. Open KGs are mostly heuristically created, automatically generated from heterogeneous resources such as text, images, etc., or are human-curated. However, these KGs are often incomplete, i.e., there are missing links between the entities and missing links between the entities and their corresponding entity types. This thesis focuses on addressing these two challenges of link prediction for Knowledge Graph Completion (KGC): \textbf{(i)} General Link Prediction in KGs that include head and tail prediction, triple classification, and \textbf{(ii)} Entity Type Prediction. Most of the graph mining algorithms are proven to be of high complexity, deterring their usage in KG-based applications. In recent years, KG embeddings have been trained to represent the entities and relations in the KG in a low-dimensional vector space preserving the graph structure. In most published works such as the translational models, convolutional models, semantic matching, etc., the triple information is used to generate the latent representation of the entities and relations. In this dissertation, it is argued that contextual information about the entities obtained from the random walks, and textual entity descriptions, are the keys to improving the latent representation of the entities for KGC. The experimental results show that the knowledge obtained from the context of the entities supports the hypothesis. Several methods have been proposed for KGC and their effectiveness is shown empirically in this thesis. Firstly, a novel multi-hop attentive KG embedding model MADLINK is proposed for Link Prediction. It considers the contextual information of the entities by using random walks as well as textual entity descriptions of the entities. Secondly, a novel architecture exploiting the information contained in a pre-trained contextual Neural Language Model (NLM) is proposed for Triple Classification. Thirdly, the limitations of the current state-of-the-art (SoTA) entity type prediction models have been analysed and a novel entity typing model CAT2Type is proposed that exploits the Wikipedia Categories which is one of the most under-treated features of the KGs. This model can also be used to predict missing types of unseen entities i.e., the newly added entities in the KG. Finally, another novel architecture GRAND is proposed to predict the missing entity types in KGs using multi-label, multi-class, and hierarchical classification by leveraging different strategic graph walks in the KGs. The extensive experiments and ablation studies show that all the proposed models outperform the current SoTA models and set new baselines for KGC. The proposed models establish that the NLMs and the contextual information of the entities in the KGs together with the different neural network architectures benefit KGC. The promising results and observations open up interesting scopes for future research involving exploiting the proposed models in domain-specific KGs such as scholarly data, biomedical data, etc. Furthermore, the link prediction model can be exploited as a base model for the entity alignment task as it considers the neighbourhood information of the entities

Array phasing device Patent

Apparatus for generating microwave signals at progressively related phase angles for driving antenna arra

Bromodeoxyuridine immunofluoresence and differential interference contrast imaging combination can precisely segregate adherent monolayer cells into specific cell-cycle phases

Most cellular-level cancer studies involve the identification of the cell cycle phases in which individual cells are progressing through. Traditional methods such as Fluorescent Activated Cell Sorting (FACS) require several treatments before harvesting the cells—procedures which alter cellular architecture. This study describes a novel method of the cell cycle analysis that preserves the cellular morphology and architecture with minimal in situ milieu perturbation. Primary rat skin fibroblasts were isolated and cultured at standard conditions. The cells were stained with anti-BrdU and examined with LSM 510 laser scanning microscopy. S-phase cells incorporated BrdU while M-phase appeared smaller and spherical. Damaged cells also tended to round-off in shape but, unlike M-phase cells, they did not bind anti-Phospho H3 antibody. G1 and G2 phases did not incorporate BrdU or Phospho H3. The two gap phases were differentiated on the basis of their sizes and subtleties in their shapes. The method is technically simple and less time-consuming while preserving the cellular in situ architecture. Due to its simplicity and accuracy the technique can be easily employed in resource-limited laboratories. Further studies are needed to verify the usefulness of the technique in clinical diagnostics such as cancer biomarkers

Morphometric parameters of clavicles among adult Black people in Tanzania

Morphological clavicular variation has been studied extensively by orthopaedic surgeons, anatomic and forensic experts to explain developmental,  gender and age-related differences. The design of fixation devices for displaced clavicular fracture management depends largely on anatomic  characteristics of clavicle. Eighty-one unpaired clavicles of unknown sex were studied, 42 clavicles were of right side and 39 clavicles of left side. All the clavicles were collected from adult cadavers which were dissected in Departments of Anatomy at Muhimbili and Herbert Kairuki Memorial  Universities. The length of clavicle was measured by a vernier calliper; the middle point of this length was taken as the point where midclavicular circumference was measured with the help of a measuring thread and the angle of curvature of clavicle was measured by using protractors. The  average lengths of the left and right clavicles were 15.23±1.12 cm and 15.43±1.01cm respectively. The average medial angle of curvature of left  clavicle was 155.33° ± 4.39°and that of right clavicle was 153.40° ± 3.96°. The mean total angle of curvature of left clavicle was 293.54˚± 9.55°and the average total angle of curvature of right clavicle was 290.05±8.94°. The average midclavicular circumference of left clavicle was 3.88cm ± 0.33cm and  that of right clavicle was 3.94cm±0.33cm. The right clavicle was longer than the left clavicle, the average medial angle of curvature of left clavicle was greater than medial angle of right clavicle, the average lateral angle of curvature of left clavicle was more than the average lateral angle of  curvature of right clavicle and the mean of midclavicular circumference of right clavicle was greater than that of left clavicle. Keywords: Morphometric, clavicle, curvatures, circumference&nbsp

Comparison of gross morphological and histological features of placenta between hypertensive and normotensive pregnant women attending Muhimbili National Hospital.

Background: Placenta is the vital fetomaternal organ that is responsible for the maintenance of the pregnancy and promotion of fetal growth and development. The optimal survival, growth, and development of the fetus correspond to the appropriate formation and development of the placenta. Hypertensive disorders of pregnancy exert a great impact on the placenta and reflect changes both morphological and histological.  Objective: To compare the morphological and histological features of the placenta between hypertensive pregnant mothers and non-hypertensive pregnant mothers who attended Muhimbili National Hospital (MNH). Methods: A hospital-based cross-sectional study was conducted from June 2020 to August 2020 at Muhimbili National Hospital (MNH).  A total of 80 placentas were studied morphologically and histologically, of which 40 placentas were from hypertensive pregnant mothers and 40 placentas were from normotensive pregnant mothers. In the morphological aspect shape, weight, the site of insertion of the umbilical cord, the number of cotyledons of each placenta and thickness of the placenta were noted. In the histological part, Neutral buffered formalin (NBF) was used the routine staining technique which was Hematoxylin and Eosin (H&E) and a light microscope was used. The data were analyzed by using SPSS version 20 computer software and the results were summarized in means and proportions. ‘T-test’ and chi-square’ tests were used and the difference was statistically significant when the p-value>0.05   Results: The irregular shape of the placenta and marginal insertion of the umbilical cord were more in the hypertensive group and were statistically significant (p>0.01). The mean placenta weight, mean placenta thickness and mean numbers of cotyledons were significantly less in a hypertensive group compared to the normotensive group (p<0.01). A microscopic study of the placenta revealed the presence of fibrinoid necrosis, syntial knots, calcifications and villous hypoplasia in both normotensive and hypertensive group however these findings were significantly higher in the hypertensive group (p>0.01). Conclusion: Hypertensive disorders of pregnancy (HDP) exert a profound impact on the placenta. Morphologically altering its dimensions and histologically fibrinoid necrosis, calcifications, syntial knots, and villous hypoplasia were significantly more in the hypertensive group than in the normotensive (p>0.01)

The choice of gadolinium-based contrast agents: a radiologist’s responsibility between pharmaceutical equivalence and bioethical issues

Contrast Agents (CA) are among the most commonly prescribed drugs worldwide, and are used, with a variety of techniques, to increase and intensify the differences between body tissues and to help radiologist make diagnoses in a fast and precise way. In recent decades, advancements in research have resulted in significant improvements in their composition, and have made them safer and better-tolerated by patients; this notwithstanding, although the currently available CA are generally considered to be safe, their use is not completely without risk. The use of CA faces the radiologist with economic considerations, bioethical dilemmas, and possible profiles of professional responsibility. In fact, to achieve the best results in diagnostic imaging, radiologists have to focus on making an appropriate choice of CA, in consideration of efficacy, safety and appropriateness. Moreover, besides by cost/benefit models widely introduced in health management, radiologists are also influenced by their responsibility of appropriate use for the various diagnostic tests and, finally, the choice of best CA to utilise for each individual patient. Thus, the dilemma of choosing between the best and the most cost-effective tests and procedures is occurring more frequently every day. Different variables, such as the patient, examinations, and technology available, can affect the choice of CA in terms of obtaining the highest diagnostic quality, minimum impact on higher-risk patients, and optimisation of used volumes and injection flow

Donor selection for allogenic hemopoietic stem cell transplantation: clinical and ethical considerations

Allogenic hematopoietic progenitor cell transplantation (allo-HSCT) is an established treatment for many diseases. Stem cells may be obtained from different sources: mobilized peripheral blood stem cells, bone marrow, and umbilical cord blood. The progress in transplantation procedures, the establishment of experienced transplant centres, and the creation of unrelated adult donor registries and cord blood banks gave those without an human leucocyte antigen- (HLA-) identical sibling donor the opportunity to find a donor and cord blood units worldwide. HSCT imposes operative cautions so that the entire donation/transplantation procedure is safe for both donors and recipients; it carries with it significant clinical, moral, and ethical concerns, mostly when donors are minors. The following points have been stressed: the donation should be excluded when excessive risks for the donor are reasonable, donors must receive an accurate information regarding eventual adverse events and health burden for the donors themselves, a valid consent is required, and the recipient’s risks must be outweighed by the expected benefits. The issue of conflict of interest, when the same physician has the responsibility for both donor selection and recipient care, is highlighted as well as the need of an adequate insurance protection for all the parties involved

Virtual image out-the-window display system study. Volume 2 - Appendix

Virtual image out-the-window display system imaging techniques and simulation devices - appendices containing background materia