Autonomous Navigation for Unmanned Aerial Systems - Visual Perception and Motion Planning

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Observations on the morphology and histochemistry of the oviducts, uterus and placenta of the sheep

As has been mentioned in the Introduction, the literature on the reproductive tract of sheep is voluminous. The oestrous cycle and the cyclic changes in the reproduc¬ tive tract of the ewe have been studied by many investigators for different purposes. The study of the placenta of sheep also received much attention due to the unique position of the cotyledonazy placenta in the classification and evolution of the mammalian placentae.In this study the morphological and histochemical changes in the oviducts, uterus and placenta of sheep, during the oestrous cycle and pregnancy, have been further investigated and new histological and histochemical observations have been added. Use of the electron micro¬ scope, freeze-drying and freeze-substitution techniques were of great advantage in the present study.The material was taken from thirty-nine non-pregnant and fifty-four pregnant sheep of Scottish breedsj fourteen specimens of pregnant animals were of known history and the rest, of unknown history, were collected from the Edinburgh abattoir.The changes in the oviducts during the oestrous cycle have been described in the text and have more or less confirmed the findings of previous authors. The tubal epithelium was found to be in a phase of growth during pro-oestrum and by the onset of oestrous to be in a phase of secretory activity, which gradually diminished towards the end of the cycle.There were no marked changes in the oviducts during pregnancy and the author could find no reference to the morphology and the fine structure of the oviducts of pregnant sheep. In the present study, the fine structure and changes in the tubal epithelium of the pregnant ewe have been described; the epithelium was found to be quiescent and many cells were degenerating during the greater part of the pregnancy period. Only towards the end of gestation did any activity appear in the epithelial cells. The ultrastructure of the tubal epithelium revealed that it consisted of ciliated and non-ciliated columnar cells in alternating groups. It also showed that the ciliated cells are non-secretory and possibly have an absorptive function since they possess microvilli.The histochemical investigation showed that the active tubal epithelial cells are rich in carbohydrateprotein complex substances. They also contain ribonucleic acid, lipids and acid phosphatase. Alkaline phosphatase was found only at the free borders of the cells and iron was also demonstrable in traces along the cell borders. The cyclical variation in the quantity and distribution of these substances within the cells has been described in the text and the secretions of the oviducts were considered to be mainly carbohydrate-protein complexes, i.e. glyco¬ proteins or mucoproteins. The significance of the other chemical substances found in the tubal cells and the lumen of the oviduct was discussed.The uterine changes during the oestrous cycle were described. It has been observed that the cyclical changes in the uterus follow closely those of the oviducts. The endometrium showed a period of growth preceded by vascularisation during pro-oestrum, a period of secretory activity during metoestrum and early dioestrum, and, finally, a period of regression and infiltration of leucocytes towards the end of the cycle. The present observations have largely agreed with the findings of previous authors. In the endometrial stroma melanocytes were encountered in some of the specimens collected and were considered to be of no physiological value. Other lymphocyte-like cells containing important chemical substances were encountered in the subepithelial layer and around the uterine glands; these have been discussed in relation to similar cells in the gravid uterus.The uterine and glandular secretions have been studied histochemically and found to be rich in a variety of important chemical substances. The cells of the uterine and glandular epithelium showed the presence of ribonucleic acid, lipids, inorganic iron and acid phos¬ phatase; alkaline phosphatase is active only at the free borders of the cells. The histoohemical reaction at the free border of the uterine epithelium and in the lumen of the uterus and the ducts of the glands showed the presence of a carbohydrate-protein complex substance. Accordingly, a possible relationship between the phosphatases present at the free borders of the cells and the mucoid substance found outside the cells was suggested and discussed.The study of the morphology and histochemistry of the gravid uterus and placenta of the ewe was a major part of the present investigation. The changes in the gravid uterus and the development of the placenta have been described in the text at different stages of pregnancy. The condition of the uterus before implantation of the blastocyst was found to be similar to that of early dioestrous, i.e. the endometrium was in the active phase. When the blastocyst came in contact with the endometrium, the uterine epithelium was destroyed at the sites of contact and before the end of the first month of gestation the blastocyst had increased enormously and the endometrium was denuded of its lining epithelium in most of the caruncular and intercaruncular areas.The destruction of the uterine epithelium and some of the endometrial stroma of the caruncles was considered to be due mainly to an ingrowth of dark staining binucleate cells of the trophoblast which migrated to the maternal side and possibly were aided by other chorionic cells. Thi3 destruction was believed to be caused by some process of digestion and absorption but not by true phagocytic action because the dark staining binucleate cells frequently seen nearest to or within the degenerating maternal tissues were apparently non-phagocytic.In the present study the formation of the foetal villi and the maternal crypts in the sheep's placentome have been described. It was found that the crypts developed before the primitive villi were formed. The histological evidence showed that the maternal tissues had degenerated in the form of tracks vertical to the surface of the caruncle, the degenerative tissues eventually disappeared and then folds of chorionic epithelium or primitive villi entered the evacuated ciypt3.The fine structure of the junctional zone of a fully differentiated placentome was examined under the electron microscope and it was found that the foetal and maternal lining cells possess apical microvilli which were interdigitating with each other except where debris and secretory granules had intervened. Intracytoplasmic inclusions were found in both foetal and maternal cell3j the former showed characteristic large vesicles near the microvilli while the latter showed characteristic electron dense granules.The histochemical reactions showed that glycogen granules were present in the walls of the foetal and maternal blood vessels. The columnar chorionic cells at the bases of the villi contained glycogen. They contained inorganic iron which is believed to be liberated by the phagocytosed red blood corpuscles. Lipid droplets were also found towards the bases of these cells. Acid and alkaline phosphatases, lipids and ribonucleoproteins were observed in greater quantities in the syncytial lining of the maternal crypts than in the chorionic epithelium.In the light of the present observations and the findings of other authors, the syncytial lining of the crypts being of foetal origin, the foetal-maternal relationship in the placentome of the ewe is believed to be a syndesmochorial one. The phosphatases and lipids in the binucleate cells and the syncytial lining were considered to be of vital importance in the transfusion of substances across the placental membrane.In the intercotyledonary areas of the sheep's placenta, the uterine epithelium was eroded in the places which were in contact with the blastocyst during early pregnancy excepting that around the glands and at the junctional zone between the caruncular and intercamncular areas and the tapering parts of the horns. The epithelium was believed to be destroyed by a similar process to that described in the caruncular areas. However, the uterine epithelium was restored in the intercotyledonary areas after the second month of pregnancy, and the foetal maternal relationship had eventually become an epitheliochorial one. The chorionic epithelium in apposition to the openings of the uterine glands wa3 thickened and invaginated giving rise to depressions known in the pig's placenta as "areolae". The uterine milk and debris were found in the spaces between the areolae and the openings of the glands.The uterine glands increased in length and complexity and they were of wide diameter and functional throughout pregnancy. The histochemical reactions showed that a copious flow of secretion was poured out by the glands. The epithelial and glandular cells contained ribonucleic acid, acid and alkaline phosphatase, lipids, and inorganic iron.lymphocyte-like cells containing intracytopla3iaic granules were observed within the uterine and glandular i epithelium of pregnant ewes. The granules were eosinophilic PAS positive, stainable by pyronim Y, i.e. containing ribonucleic acid, and showed alkaline phos¬ phatase activity. The similarity and relationship between these cells, the lymphocytes of the endometrial stroma and the plasma cells were discussed.Large round cells containing pigments, PAS positive material, phosphatases and ribonucleic acid, were observed in the endometrial stroma of pregnant ewes and these cells were considered to be macrophages of the endometrial connective tissue

Genetic studies of bacterial wilt resistance and agronomic characters, and yield component analysis in tomato

Experiments were conducted to evaluate the inheritance and performance of six tomato parental lines (varieties) and their respective cross combinations. Inheritance of bacterial wilt resistance was evaluated in the greenhouse (screening experiment), while assessments of twelve agronomic characters were made under hydroponic conditions. Greenhouse inoculation studies indicated that, parents have different degree of susceptibility to bacterial wilt. There were significant differences (P = 0.01) among genotypes as indicated by their disease index. Studies carried out under hydroponic conditions showed that except for the number of branches per plant and stem diameter, there were significant differences (P = 0.01) among the means of all the characters studied. Different degree of heterosis have been expressed for different characters. For the three populations studied. resistance to bacterial wilt showed high heterosis over mid parental value and no heterosis over better parental value. On the other hand. for most of the agronomic characters in the five populations studied. a majority showed heterosis over better parent, but their values were not high. However. mid parental heterosis values were mostly high. Heritability estimates were generally high for most characters including disease index. This indicated that the additive genes were more important than non-additive genes. Yield characters (viz. number of fruits per plant, average weight per fruit and fruit diameter) were highly and positively correlated with each other. Maturity characters (days to flowering and days to first harvest) were in general negatively correlated with yield. The path coefficient analysis revealed that the number of fruits per plant, average weight per fruit, and fruit diameter were the most important characters that contributed directly to the yield. Therefore. in any breeding programme selection for disease resistant plants (genotypes) after each generation of selfing should also take into consideration other desirable agronomic characters

Effect of processing conditions on the microbiological quality of white pickled cheese

Effects of starter culture, nisin, H2O2 and potassium sorbate on Listeria monocytogenes, Staphylococcus aureus and Salmonella typhimurium in white pickled cheese made from pasteurized milk with 4% salt and preserved in 4% brine solution at 4°C for 60 days was studied. The starter culture inhibited all three pathogens while antimicrobials did not. Beyond day 50 in curd and day 30 in brine solution, L. monocytogenes was not detected by direct plating. S. aureus was not detected after day 30 in curd and day 20 in brine solution. S. typhimurium was not detected after day 30 in cheese curd, and was not detected in brine solution at any time. The pH of brine solution of starter treatment dropped below 4.7 in all experiments, while antimicrobial treatments had always pH above 5.5. The chemical composition of white pickled cheese made from pasteurized milk with 8% salt and preserved in the whey at 4°C for 60 days was determined, and the cheese was challenged with L. monocytogenes. While fat, protein, total solids and ash contents decreased in curd during ripening, the acidity and salt did not change. In cheese whey, fat, protein, acidity and salt showed a slight increase while total solids and ash contents were unchanged. High salt did not affect L. monocytogenes and suppressed the activity of lactic acid bacteria such that they were not able to produce acid and inhibit L. monocytogenes. During ripening, the pH never decreased below 6.0. A single strain of Lactococcus lactis ssp. cremoris was isolated from a commercial cheese culture and chemical mutation was attempted to develop salt-resistant mutants for use in high salt white pickled cheese. No salt-resistant mutant was isolated

PROPOSED METHODOLOGY FOR OPTIMIZING THE TRAINING PARAMETERS OF A MULTILAYER FEED-FORWARD ARTIFICIAL NEURAL NETWORKS USING A GENETIC ALGORITHM

An artificial neural network (ANN), or shortly "neural network" (NN), is a powerful mathematical or computational model that is inspired by the structure and/or functional characteristics of biological neural networks. Despite the fact that ANN has been developing rapidly for many years, there are still some challenges concerning the development of an ANN model that performs effectively for the problem at hand. ANN can be categorized into three main types: single layer, recurrent network and multilayer feed-forward network. In multilayer feed-forward ANN, the actual performance is highly dependent on the selection of architecture and training parameters. However, a systematic method for optimizing these parameters is still an active research area. This work focuses on multilayer feed-forward ANNs due to their generalization capability, simplicity from the viewpoint of structure, and ease of mathematical analysis. Even though, several rules for the optimization of multilayer feed-forward ANN parameters are available in the literature, most networks are still calibrated via a trial-and-error procedure, which depends mainly on the type of problem, and past experience and intuition of the expert. To overcome these limitations, there have been attempts to use genetic algorithm (GA) to optimize some of these parameters. However most, if not all, of the existing approaches are focused partially on the part of architecture and training parameters. On the contrary, the GAANN approach presented here has covered most aspects of multilayer feed-forward ANN in a more comprehensive way. This research focuses on the use of binaryencoded genetic algorithm (GA) to implement efficient search strategies for the optimal architecture and training parameters of a multilayer feed-forward ANN. Particularly, GA is utilized to determine the optimal number of hidden layers, number of neurons in each hidden layer, type of training algorithm, type of activation function of hidden and output neurons, initial weight, learning rate, momentum term, and epoch size of a multilayer feed-forward ANN. In this thesis, the approach has been analyzed and algorithms that simulate the new approach have been mapped out

Analysis of IVAT laboratory grounding system using CDEGS software

Practical tests on grounding systems has proved very costly and pose hazards on operating personnel. Therefore, numerical methods using computers provide the m ost appropriate tool to assess the earthing systems. The research has been conducted with the utilization o f CDEGS software as a tool to simulate all necessary phenomena on the built CDEGS model o f the grounding system in IV A T’s laboratory. In particular, the ground potential rise, touch voltages, and step voltages plots are the main outputs generated. Six lightning scenarious catergorized into low, medium and hight levels are applied on the proposed grounding system to assess for the IVAT’s earthing structure safety. The IEEE 80-2000 standard is used to calculate the maximum allowable limits for surface potentials and employed as set point. Obtained results were compared to the safety lim it of the standard and proved safe only for the low level when no protective layer is in use. However, the system was completely safe and m et the standard’s limits for low, medium and high levels of lightning strikes when a protective layer is in place

Design and Simulation of a Low Frequency Electrostatic Comb-drive Energy Harvester Using 0.35μm CMOS Technology

This project is to design, model and simulate an electrostatic comb-drive energy harvester. The device harvests the vibration energy from outside source and converts it into electric energy to supply wireless node sensors. Simulation is conducted using the CoventorWare software to simulate and optimize the device. CoventorWare simulation result has obtained a resonant frequency of 5 KHz

Production and Characterization of Pectic Enzymes of Xanthomonas campestris pv. sesami

إنتاج ودراسة خصائص الإنزيمات البكتينية للبكتيريا Xanthomonas campestris pv. sesami   ملخص الدراسة            البكتيريا  Xanthomonas campestris pv. sesami ، هي المسبب لمرض تبقع أوراق نبات السمسم. الأنزيمات البكتينية التي تنتج بواسطة العديد من البكتيريا الممــرضة للنبات اتضـح أنها تلعب دوراً هاماً في عمــلية الأمراض. هنالك ثلاث أنواع رئيـسـية من الإنزيمات البكــتينية (بوليجلاكتيورونيز، PG وبوليجلاكتيورونيت ترانس - امنيز، PTE و بكتين ميثايل - اٍستريز، PME). هـدف هذا البحث على دراسة قدرة البكتيريا، X.  campestris pv. sesami  على إنتاج الإنزيمات البكتينية المختلفة. استخدم في هذه الدراسة وسط غذائي من الأملاح مضافاً إليه مواد بكتينية مختلفة كمصدر للكربون. الإنزيمات المنتجة تمت دراسة خصائصها باستخدام اختبارات محددة. أوضحت النتائج أن البكتيريا كانت قادرة إنتاج الإنزيم بوليجلاكتيورونيت ترانس - اٍمنيز ((PTE فقط ولم تنتج الانزيم بكتين ميثايل - اٍستريز، PME)). أشارت النتائج الى أن ملح بولي بكتات الصوديوم وحمض البولي جلاكتيورونيك  هي الأفضل لإنتاج هذا الإنزيم حيث أعطت  9 .26 و 19.8 وحدات لزوجة إنزيمية، على التوالي. . كان أعلى إنتاج للإنزيم في اليوم السادس (9.3 وحدات لزوجة)  ثم انخفض الإنتاج مع زيادة فترة التحضين. اختبار تأثير درجة الأس الهيدروجيني أوضح أن الدرجة المثلى لنشاط  الإنزيم كانت 9.0. أظهرت دراسة اختبار تاثيز ايونات لمعادن مختلفة على نشاط الانزيم أن أيونات الكالسيوم هي التي أعطت اكبر نشاط 12.2  وحدة لزوجة. وعند اختبار تراكيز مختلفة من  ايونات الكالسيوم ووجد ان اعلى نشاط كان على التركيز  50 ملج / مل حيث أعطى 18.0 وحدة لزوجة. توصي الدراسة على اختبار قدرة البكتيريا على انتاج إنزيمات السليولوز وشبه السليولوز والتي لها دور ايضاً في عملية الاٍمراض.       The bacterium Xanthomonas campestris pv. sesami, is the causal organism of the leaf spot disease (Marad eldum) in sesame plants. Pectic enzymes which were reported to be produced by many plant pathogenic bacteria,  were found to play an important role in pathogenesis. There are three main types of pectic enzymes (Polygalacturonase, PG, Polygalacturonate trans-eliminase PTE and Pectin methylesterase PME). The present study was conducted to investigate the capacity of the bacterium X. campestris pv. sesami,  to produce the different types of pectic enzymes. A salt medium supplemented with different pectic materials as carbon sources were tested for the production of the enzymes. The produced enzymes were characterized using different selective tests, both the viscosity and reducing group methods were used to measure the enzyme activity. The results showed that no pectin methylestrease (PME) was produced and only the Polygalacturonase trans-eliminase (PTE) was produced by the bacterium. Sodium polypectate and polygalacturonic acid were found as the best substrates giving 26.9 and 19.8 viscosity enzyme units, respectively. The enzyme activity was maximum at the 6th day (9.3 viscosity units), then the activity was decreasing with further incubation time. The test of the effect of the pH indicated that the  pH optimum of the enzyme activity was at pH 9.0. The effects of different metallic ions to the enzyme activity showed that,= a higher activity was found with Ca++ which gave 12.2 viscosity    units. When different concentrations of Ca++ were tested, the maximum activity of the enzyme was found at 50 mg/ ml concentration, which gave 18.0 viscosity units. It could be recommended that the tested bacterium should be investigated for the production of the cellulases and hemi-cellulases which also have a role in the pathogenesis process

Classification of customer call details records using Support Vector Machine (SVMs) and Decision Tree (DTs)

On a daily basis, telecom businesses create a massive amount of data. Decision-makers underlined that acquiring new customers is more difficult than maintaining current ones. Further, existing churn customers' data may be used to identify churn consumers as well as their behavior patterns. This study provides a churn prediction model for the telecom industry that employs SVMs and DTs to detect churn customers. The suggested model uses classification techniques to churn customers' data, with the Support Vector Machine (SVMs) method performing well 98.36 % properly categorized instances) and the Decision Tree (DTs) approach performing poorly 33.04 % and the decision tree algorithm deliver outstanding results

Detection of Most Congested Roads in Khartoum City Center using Geographical Information Systems Methods

The aim of this research is to Detect the Most Congested Roads in Khartoum City Center by studying the different causes of traffic congestion using GIS methods . Spatial and descriptive data of the congestion causes have been collected In the last three months, site plan, traffic plan ,random parking, bus lines and bus stations, natural and artificial obstacles ,entrance and exit of study area. Geographical database is created for geometrical analysis, to find out the most affected roads. This helps in developing economical solutions to the problem of traffic congestion