Embedded System development with PSOC : orientation sensing and visualization with PSOC

This thesis describes a new embedded system development process. The thesis aims to demonstrate how embedded systems could be developed efficiently with the help of the new technological advances such as programmable systems on chips. A special focus is given on HW and SW programming of such systems. The project makes use of a new generation of a chip called Programmable System on Chip (PSoC) as its hardware platform. What distinguishes PSoC from a line of processors and system on chips is its programmable hardware. This feature allows embedded system designers to be able to customize part of the hardware programmatically in addition to writing a software application that runs on top of the system. This thesis introduces the development of an embedded system based on the PSoc chip and development environment provided by Cypress semiconductors. Finally, this thesis presents a position sensing application which demonstrates the development process of a modern day typical embedded system

Integration of rapid hot water treatments and biocontrol agents to control postharvest pathogens of tomato.

Masters Degree. University of KwaZulu-Natal, Pietermaritzburg.Anthracnose and sour rot caused by Colletotrichum and Galactomyces (syn. Geotrichum) species, respectively, are major fungal postharvest pathogens causing significant losses of tomato fruit. The growing public concern over human health and environmental risks posed by pesticides, the accumulation of chemical residues in fruit, and the production of secondary effects on fruit, as well as the development of resistant strains has reduced the available options of synthetic fungicides to control these pathogens. Finding alternatives or integrated approaches to provide disease control comparable to the use of synthetic fungicides is therefore needed, especially for the control of postharvest diseases, while maintaining a high quality of fruit during storage and marketing. The overall objective of this study was to develop an integrated treatment that combined rapid hot water treatments with biological control agents to control two postharvest pathogens of tomato, Colletotrichum and Galactomyces spp., and to track their impact on the postharvest quality of tomato fruit. The mechanisms of rHWTs and antagonist yeasts involved in decay control were also investigated, in passing. Isolation and Identity of the Pathogens Isolation and identification of fungal pathogens associated with tomato fruits were carried out to determine the most common fungi associated with tomato spoilage in South Africa. A total of 55 isolates were recovered from symptomatic tomato fruits with typical symptoms of anthracnose and sour rot. The cultural and morphological characteristics of all isolates were observed and compared with standard descriptions to establish their identity. Pathogenicity tests were performed. The effects of wound and non-wound inoculation methods on the infection process and disease development were studied by scanning electron microscopy (SEM). The identities of one of the most pathogenic isolates of each pathogen were then determined using the consensus sequences and the nucleotide Basic Local Alignment Search Tool (BLASTn) on The National Center for Biotechnology Information (NCBI) website. Out of the 55 isolates, 33 were Colletotrichum spp., and the other 22 isolates were Galactomyces speciesp. Colletotrichum isolates were further classified into Colletotrichum gloeosporioides and Colletotrichum acutatum, based on cultural and morphological analyses. All the Galactomyces isolates were similar and were identified as strains of Galactomyces candidum. Among the isolated strains, C24 and C37A from the Colletotrichum isolates, and G18, G23 and G29 from the Galactomyces isolates, were extremely pathogenic. SEM results showed that all wound and non-wound Colletotrichum inoculated fruits developed anthracnose, whereas non-wound Galactomyces inoculated fruits failed to develop sour rot, indicating that Galactomyces requires a wound for infection to occur. Molecular analyses confirmed the identities of the pathogens as Colletotrichum gloeosporioides (Penz.) and Galactomyces candidum Butler & Petersen (anamorph: Geotrichum candidum Link). The detection of these predominant fungal pathogens in this study indicated that both fungal pathogens are widely distributed on tomato fruit in KwaZulu-Natal. There is therefore a need to roll out effective and sustainable control strategies. Isolation, screening and identification of yeast strains A total of 148 yeast isolates were recovered from the surface of tomato fruits and were screened for antifungal activity in vitro using a dual culture assay. Only 25 isolates had strong antifungal activity against C. gloeosporioides and G. candidum. These isolates were then screened for phytotoxicity on healthy tomato fruits. Subsequently ten yeast isolates, which were non-phytotoxic to tomato fruits and which inhibited both pathogens, were selected for in vivo testing of their antifungal activity and their effects on tomato quality. The effects of delays between pathogen inoculation after yeast treatment, as well as the mechanism of decay control, were studied using SEM. Out of these 25 isolates, 4 were excluded for showing phytotoxic effect on the fruits. Isolates Y108, Y121 and Y124 showed strong antagonistic effects against both pathogens with no detrimental effect on the fruit. However, the application of the best 10 antagonist yeasts had no effect on the general quality parameters of the tomato fruits. The identity of the best three antagonist yeast isolates was then determined using molecular analysis of their sequences of the internal transcribed spacer (ITS) regions, which identified the best three isolates as strains of Meyerozyma guilliermondii (Wick) Kurtzman. The biocontrol efficacy of the yeast isolates was affected by the timing of their application. The yeast cells needed time to multiply, and thereby provide preventative protection. The sooner the application of the yeast treatments, the better was the biocontrol efficacy of the antagonist yeasts. Competition for nutrients, attachment to fungal hyphae and production of an extracellular matrix were among the probable modes of action of the antagonist yeasts in this study. The best isolates of M. guilliermondii, especially isolate Y108, were effective as biocontrol agents against C. gloeosporioides and G. candidum and could provide a sustainable alternative to the use of chemical pesticides. Hot water treatments with temperatures of 20, 44, 47, 50, 53, 56, 59, 62, 65, 68, 71 and 80℃ were applied to tomato fruit for periods of 10, 20 and 30s on non-inoculated and inoculated fruit, in order to determine the optimal temperature x time combinations on pathogen control and postharvest quality traits of fruits. The effect of shorter times at the best working temperatures were also tested. The mechanism of heat treatments on decay control was then studied using the SEM. The temperature regimes at which no heat damage occurred on the skin of tomato fruits were 20℃, and from 44℃ to 59℃, at all exposure times, and at 62℃ for 20s. With increased temperature x time combinations above these levels, all treatments caused heat damage, which appeared as peeling, scalding, cracking and ageing either at the same time of treatment, or after 10 days of storage at 25℃. The best combinations of the rHWTs significantly reduced disease incidence, while maintaining fruit quality. These were: 56℃ x 20s, 59℃ x 10s and 62℃ x 10s. Moreover, the combinations of 56℃ x 15s, and 62℃ x 8s were even more effective. Heat treatments caused the melting of the wax platelets of the fruit, sealing cracks in the wax cover of fruit, which remained highly visible on control fruits. Induction of host defence, and inhibition of sporulation and mycelial growth were among the possible modes of action of HWTs in this study. The results have demonstrated the high potential of rHWTs to control C. gloeosporioides and G. candidum, while maintaining postharvest quality during storage, thus prolonging the shelf-life of tomato fruit. Therefore, rHWTs should be considered as a viable technology for the control of postharvest diseases of tomato fruits on a commercial level. rHWT, equivalent to pasteurization, is a rapid process, and avoids introducing a delay in the processing time of large volumes of fruit going through a commercial packhouse. The application of rHWTs and antagonist yeasts each provided significant control of both C. gloeosporioides and G. candidum. The combination of these two treatments enhanced the efficacy of both individual treatments. The integration of rHWTs at 62 x 8s with the yeast M. guilliermondii isolate Y108 resulted in the best disease control against both C. gloeosporioides and G. candidum, and delivered enhanced tomato fruit quality postharvest. This enhanced effect of rHWTs in combination with antagonistic yeasts could be the result of various interactions between the heat treatments, antagonist yeasts and the fruit. The results presented in this thesis highlight the potential to use biological and physical disease control management strategies, as stand-alone treatments or in combination, as alternative control measures against postharvest tomato anthracnose and sour rot. Although both rHWTs and antagonist yeasts reduced both C. gloeosporioides and G. candidum incidence, the combined treatment provided the best disease control with the best fruit quality. Heat treatments partially disinfect fruit, allowing for the successful colonization of the fruit surfaces and wound sites with antagonist yeasts, which then provide a residual disease control effect for the fruits. Integration of these treatments enhanced persistence and stability of each single treatments, which would be valuable in the tomato industry as part of an effective disease management strategy, which would be economically viable, readily implemented and environmentally sound. Further research is required to implement the technology at an industrial scale

The state of tourism in Eritrea : tourism development in the Dahlak Islands

Along its Red Sea coast Eritrea possesses not less than 350 Islands. Dahlak Kebir, the largest of all is located approximately 50kms off the coast of Massawa, the busiest port of Eritrea. Topographically, relatively low relief limestone encircled by clean waters, abundant coral reefs and bountiful of fish species are the dominant features of the Islands. Nevertheless, their rich resources are so far not harnessed. They are inhabited by small fishing communities. One could only witness a small hotel and few houses scattered here and there, except for the presence of a military base on both Dahlak Kebir and in the near by Nakura Islands. The archaeological site of the Necropolis, a large early Islamic cemetery, and nearby ancient cisterns and pre Islamic cemetery, lies on the southwestern side of the Island. The story of Dahlak and its ruins are clear testimony that the archipelago has a mine of very rich history that needs to be explored. In the 7th century, for instance, it was through these Islands that the Islamism has infiltrated and eventually penetrated deep into various parts of Eritrea and Ethiopia. In between the beginning of the 8th and mid-9th century, the archipelago was conquered and occupied by various external powers such as the Byzantine Empire. In the 13th century, during the period of internal uprising in the Arab world, Dahlak established its own autonomous Sultanate. In latter years, Portuguese and Ottoman Kingdoms used to control the Islands and to assert their supremacy in the Red Sea. In 16th century, however, Dahlak was exclusively occupied by the Ottomans and was used as a launching ground to conquer and control the costal part and highland of Eritrea. Finally, in the 1870s Mohammed Ali of Egypt became master of the Islands. Dahlak was also known to have been the centre of trade for slaves on the Horn from the beginning of its occupation by Ottomans until its occupation of the Islands and the Red Sea coast by the Egyptians. (Eritrean travel and trade manual 2000) The prospect of the Dahlak Archipelago for the development of a successful tourist industry in Eritrea could undoubtedly be feasible. The low-lying coral chains where these volcanic Islands are located is amazingly tantalizing, fascinating and picturesque beyond description. Environmentally unpolluted, they are hygienic health-wise and could therefore be the primary attractions for tourists. Clean water and warm climate being their outstanding features, tourists could easily be lured to enjoy themselves without much ado about worrying their welfare, given their graceful natural environment is protected from deteriorations by contamination. White sandy beaches, protective bays and lagoons, provide excellent conditions for diving, snorkeling, sailing wind surfing and other sport activities. (Travel Trade Manual of Eritrea, 2000)Dissertation (MPhil (Tourism Management))--University of Pretoria, 2008.Tourism ManagementMPhilunrestricte

On the Giant Component of Geometric Inhomogeneous Random Graphs

In this paper we study the threshold model of geometric inhomogeneous random graphs (GIRGs); a generative random graph model that is closely related to hyperbolic random graphs (HRGs). These models have been observed to capture complex real-world networks well with respect to the structural and algorithmic properties. Following comprehensive studies regarding their connectivity, i.e., which parts of the graphs are connected, we have a good understanding under which circumstances a giant component (containing a constant fraction of the graph) emerges. While previous results are rather technical and challenging to work with, the goal of this paper is to provide more accessible proofs. At the same time we significantly improve the previously known probabilistic guarantees, showing that GIRGs contain a giant component with probability 1 - exp(-?(n^{(3-?)/2})) for graph size n and a degree distribution with power-law exponent ? ? (2, 3). Based on that we additionally derive insights about the connectivity of certain induced subgraphs of GIRGs

A Primal-Dual Algorithm for Multicommodity Flows and Multicuts in Treewidth-2 Graphs

We study the problem of multicommodity flow and multicut in treewidth-2 graphs and prove bounds on the multiflow-multicut gap. In particular, we give a primal-dual algorithm for computing multicommodity flow and multicut in treewidth-2 graphs and prove the following approximate max-flow min-cut theorem: given a treewidth-2 graph, there exists a multicommodity flow of value f with congestion 4, and a multicut of capacity c such that c ? 20 f. This implies a multiflow-multicut gap of 80 and improves upon the previous best known bounds for such graphs. Our algorithm runs in polynomial time when all the edges have capacity one. Our algorithm is completely combinatorial and builds upon the primal-dual algorithm of Garg, Vazirani and Yannakakis for multicut in trees and the augmenting paths framework of Ford and Fulkerson

Efficient Constructions for the Gy\H{o}ri-Lov\'{a}sz Theorem on Almost Chordal Graphs

In the 1970s, Gy\H{o}ri and Lov\'{a}sz showed that for a $k$-connected $n$-vertex graph, a given set of terminal vertices $t_1, \dots, t_k$ and natural numbers $n_1, \dots, n_k$ satisfying $\sum_{i=1}^{k} n_i = n$, a connected vertex partition $S_1, \dots, S_k$ satisfying $t_i \in S_i$ and $|S_i| = n_i$ exists. However, polynomial algorithms to actually compute such partitions are known so far only for $k \leq 4$. This motivates us to take a new approach and constrain this problem to particular graph classes instead of restricting the values of $k$. More precisely, we consider $k$-connected chordal graphs and a broader class of graphs related to them. For the first, we give an algorithm with $O(n^2)$ running time that solves the problem exactly, and for the second, an algorithm with $O(n^4)$ running time that deviates on at most one vertex from the given required vertex partition sizes

Balanced Crown Decomposition for Connectivity Constraints

We introduce the balanced crown decomposition that captures the structure imposed on graphs by their connected induced subgraphs of a given size. Such subgraphs are a popular modeling tool in various application areas, where the non-local nature of the connectivity condition usually results in very challenging algorithmic tasks. The balanced crown decomposition is a combination of a crown decomposition and a balanced partition which makes it applicable to graph editing as well as graph packing and partitioning problems. We illustrate this by deriving improved approximation algorithms and kernelization for a variety of such problems. In particular, through this structure, we obtain the first constant-factor approximation for the Balanced Connected Partition (BCP) problem, where the task is to partition a vertex-weighted graph into k connected components of approximately equal weight. We derive a 3-approximation for the two most commonly used objectives of maximizing the weight of the lightest component or minimizing the weight of the heaviest component

Connected k-Partition of k-Connected Graphs and c-Claw-Free Graphs

w_k. In particular for the balanced version, i.e. w? = w? == w_k, this gives a partition with 1/3w_i ? w(T_i) ? 3w_i

Estimating the chemical composition of secondary compounds of Iraqi wild Agaricus bellaniae characterized morphologically and genetically

هدفت هذه الدراسة التي تعد الأولى من نوعها في العالم والوطن العربي التي أجريت في مختبر أنتاج الفطر التابع لوحدة بحوث النباتات الطبية/ كليةعلوم الهندسة الزراعية– جامعة بغداد للفترة من 21 تموز 2016 ولغاية  30 كانون الأول 2018 إلى عزل وتنقية الغزل الفطري للعزلة البرية ، ثم إجراء التشخيص المظهري والجيني لها ،إذ اظهر ان العزلة البرية تعود للفطر Agaricus bellaniae بعدها تم ترميز العزلة النقية  التي تم الحصول عليها في منظمة NCBI الأمريكية بالرمز MF987843.1وبذا يكون العراق ثاني دولة في العالم ينمو فيها الفطر بعد الولايات المتحدة الامريكية ،كما تم تحديد درجات الحرارة المثلى لسرعة نمو الغزل الفطري مختبريا ،إذ تراوحت مابين50 -60◦م ،كما تم اجراء التشخيص النوعي والكمي لمحتوى الاجسام الثمرية المجففة للفطرالبري لمعرفة محتواه من المركبات الفعالة طبيا ،إذ اظهرت ارتفاع نسبة كل من  Linoleic acid47.77 % و مضادات الاكسدةالكليةوالفينولاتالكلية والفلافونويدات الكلية ، فضلا عن محتوى الاجسام الثمرية من المركبات الكيمائية الاساسية وخصوصا ارتفاع نسبة البروتين 44% والعناصر المعدنية خصوصا عنصر السلينيوم0.3691ppm والاحماض الامينية والتي سجل كل من حامضي الكلوتاميكوالاسبارتيك نسبة مرتفعة بلغت 4.02 % و2.26 % على التوالي.   This study, which is considered the first of its kind in the world and the Arab homeland, was carried out in the laboratory of mushroom production belonging to the Medicinal Plant Unit/ College Of Agricultural Engineering Sciences/ University of  Baghdad during the period from July 21, 2016, to December 30, 2018, aiming to isolate and purify the mycelium of the wild isolation in addition to the genetic and morphological identification of the mushroom Agaricus bellaniae. The obtained pure isolation was tagged in the American National Center for Biotechnology Information (NCBI) with symbol MF987843.1, thus Iraq would be the second country in the world in which the mushroom is grown following the United States of America. The optimum temperature for the mycelium growth rate was also determined in the laboratory, as they ranged between 50 -60 ◦C. Furthermore, the dried fruit bodies were recognized qualitatively and quantitatively to identify their content of medicinally active compounds. Theyhave shown a high percentage of  Linoleic acid (47.77%), total anti-oxidants, and total phenols in addition to the high content of essential chemicals including high protein percentage (44%), mineral elements- selenium in particular (0.369 ppm), and amino acid where glutamic and aspartic acids recorded the highest percentage, reached 4.02% and 2.226% respectively

Improving propagation of Echinacea purpurea and its content of some active compounds by using Tyrosine and Salicylic acid in vitro

The seed propagation is the predominant method of Echinacea propagation, which has been criticized for its time-consuming control over the separation factor and the uncertainty of pathogen-free plants produced by this method. The technology of tissue culture has provided multiple opportunities for the production of secondary metabolites continuously without being restricted to a specific season, due to the possibility of controlling the environmental conditions and the components of the nutrient medium needed by the plant. This study was conducted to investigate the effects of salicylic acid as elicitor and tyrosine as precursor on propagation and some secondary compounds production in coneflower in vitro. The result showed the superiority of 2 mg / liter SA over the other treatments, which gave the highest average number of branches formed reaching 33.6 branches / plant part, number of leaves 33.6 leaves/vegetable part, fresh 1.067g and dry 0.058g weights as well as echinacoside concentration  of 291.3427 μg / g DW. However, the treatment 100 mg/l tyrosine gave a maximum of average number of branches 11.80 branches / plant part, number of leaves 11.80 leaves/vegetable part, fresh and dry weight 0.152 and 0.023 g respectively. Concerning echinacoside value, its maximum 318.5203 μg / g DW was recorded with 150 mg/l tyrosine. From this study, we concluded that caffeic acid derivatives such as echinacosides are one of the main phytochemical components of Echinacea extracts. The system of cell culture is a tool for the large-scale, year-round culture of plant cells, so it is a continuous source for the production of active compound