Detection of Viral Hemorrhagic Septicemia virus (VHSV) from the leech Myzobdella lugubris Leidy, 1851

The leech Myzobdella lugubris is widespread in the Lake Erie Watershed, especially Lake St. Clair. However, its role in pathogen transmission is not fully understood. In this same watershed, several widespread fish mortalities associated with the Viral Hemorrhagic Septicemia virus (VHSV) were recorded. Viral Hemorrhagic Septicemia is an emerging disease in the Great Lakes Basin that is deadly to the fish population, yet little is known about its mode of transmission. To assess the potential role of M. lugubris in VHSV transmission, leeches were collected from Lake St. Clair and Lake Erie and pooled into samples of five. Cell culture and reverse transcriptase polymerase chain reaction (RT-PCR) were used to determine the presence of the virus and its identity. Results showed that 57 of the 91 pooled leech samples were positive by cell culture for VHSV and 66 of the 91 pooled leech samples were positive by RT-PCR for the VHSV. Two representative virus isolates were sequenced for further genetic confirmation and genotype classification. VHSV detected within M. lugubris was homologous to the Great Lakes strain of VHSV genotype IVb. This is the first record of the VHSV being detected from within a leech, specifically M. lugubris, and suggests the potential of M. lugubris being involved in VHSV transmission

Microgrid modelling and online management

Modern power network owners have to respond to a number of challenges such as significant load changes and growth in the geographical distribution of the customers. On the other hand, the environmental policy and economic requirements from the market are constantly growing. The presence of these problems has led to an increased interest in the local renewable energy generation at the distribution level. The Microgrid (MG) concept assumes a cluster of loads and microsources operating as a single controllable system that provides both power and heat to its local area. Not much is known about Microgrid behavior as a whole system. Some models exist which describe the components of the Microgrid. This thesis aims to model Microgrids at steady state and study their transient responses to changing inputs. Currently models of a Diesel Engine, a Fuel Cell, a Microturbine, a Windturbine, a Photovoltaic cell, and Battery storage have been developed. In this thesis, a generalized formulation is introduced to determine the optimal operating strategy, the goal to minimize the operating costs as well as the reduction of the emission costs and level for a MicroGrid. To solve such a management problem it is first formulated as a nonlinear constrained cost optimization problem. Since the management problem poses a number of simultaneous objectives and constraints a Multiobjective optimization problem is formulated by considering the emission level reduction. A daily income from sold power and cost to be paid to the utility of the purchased power is added to the problem. The model takes also into consideration the reduction of emissions caused by NOx, SO2 and CO2. The optimization is aimed to minimize the operating costs of the system, while constraints are adjusted to meet the customer demand and the safety of the system. Different optimization techniques are applied to solve the problem, such as Mesh Adaptive Direct Search, Sequential Quadratic Programming, Genetic Algorithms, and Game Theory. Test cases provide comparison and evidence of the efficiency of the proposed methods.reviewe

Pseudoxanthomaelasticum with congestive heart failure: A case report

Pseudoxanthomaelasticum (PXE) is a rare systemic disease of connective tissue primarily affecting the skin, retinae, and cardiovascular system. Clinically it has high hetrogenicity in age of onset, extent and severity of disease. Its cardiovascular effect has a wide clinical spectrum extending from mental fatigue to early death from myocardial infarction. Very rarely it may present with gastrointestinal haemorrhage. It has no specific treatment. However, adjustments of the life stile are important to reduce morbidity. Moreover, first degree relatives should be carefully examined for cutaneous and ophthalmic features of this disease. Here we describe one case of Pseudoxanthoma Elasticum. Sudan Journal of Medical Sciences Vol. 1(1) 2006: 62-6

FINE NEEDLE ASPIRATION CYTOLOGY (FNAC) IN DIAGNOSIS OF TUMORAL CALCINOSIS, A REPORT OF THREE CASES

Introduction: Tumoral calcinosis (T.C.) is very rare and generally of unknown aetiology characterized by calcific deposits in the soft tissues. Commonly seen in the second decade of life (reported age range 15 months to 83 years). We are reporting 3 cases of T. C. who were initially diagnosed by FNAC. Two of the 3 cases were female siblings who were referred to us as possible cases of recurrent fibrosarcomas following surgical excision. Case reports:  (1) Two female siblings aged 17 and 14 years  complaining of large swelling in the upper   outer right thigh and the left outer upper thigh around the hip joints respectively. There was no limitation of movement. The masses recurred within a short period after total excision. Neither specimen was subjected to histopathology. Clinical examination showed two masses each approximately 30cm maximum diameter and 10 cm width. In addition the younger sister showed an additional mass 4.5 cm in the outer aspect of her right elbow. (2) 18 months old female child, unrelated to the above two cases, presented with an egg-sized mass in the mid-lateral aspect of her right thigh  cystic and mobile.There is a history of quinine injection in the same area. No positive family history of a similar condition. All three cases showed normocalcaemia and hyperphosphataemia with specks of calcification on x - ray and cysts in ultrasound. FNAC showed structureless gung , calcium granules and inflammatory cells including foreign body type multinucleated giant cells. Histopathology confirmed the diagnosis of T. C. Discussion: Described the three types of T. C. (familial, idiopathic, and that in patients of chronic renal failure on dialysis). The differential diagnoses were also discussed as well as lines of management such as Ca++ supplementation, phosphate restriction, acetazolamide, parathyroidectomy and the treatment of choice is total surgical excision. To our best knowledge this is the first time to report the use of fine needle aspiration cytology in the diagnosis of T. C. in Sudan.&nbsp

IDS IN TELECOMMUNICATION NETWORK USING PCA

ABSTRAC

Power Quality and System Stability Impact of Large-Scale Distributed Generation on the Distribution Network: Case Study of 60 MW Derna Wind Farm

Wind energy (WE) has become one of the most promising and developed forms of renewable energy source due to its efficiency and the availability of different capacities according to the loading requirements. The integration of wind turbines in the Libyan network has become an indispensable choice due to Libya’s distinguished location and for the Libyan National Initiative. Despite the numerous benefits of WE, the penetration of WE sources in the distribution network has some negative impacts related to the quality and reliability of the electric power supplied to the network. Owing to, the intermittent nature of these sources and electronic circuits needed to regulate the extracted power to comply with the grid requirements. In this chapter, implementation of the eastern Libyan network in NEPLAN and MATLAB/SIMULINK packages are carried out to investigate and analyze the significance of wind farm penetration in the medium voltage level of Libyan Distribution Network. A 60 MVA wind farm system has been connected to the Libyan distribution network according to the Libyan National Initiative. Different penetration scenarios are simulated to testify the technical aspects of integrating WE on the distribution level

Pre-determination of partial discharge inception voltage in power cables using electrode gaps in air under AC voltage

The breakdown of insulation in cables while in service can cause considerable damage to equipment and the accessories to which they are connected. PD in cables arises due to the overstressing of cable insulation resulting from electric field enhancement caused by imperfections in cable core and screen. The nature and magnitude of PD activity depends upon the type of defect, aging, environmental factors, applied voltage and cable loading. Reduction in system voltage can potentially reduce PD, which will correspondingly extend the service life of the cable. Currently, industry voltage statutory requirements permit ±6% tolerance setting on nominal voltage on distribution networks. This ±6% voltage reduction on may have little or an adverse effect on PD magnitude depending on the nature of defect present in the cable. Hence there is a clear requirement to pre-determine the PD inception voltage in cables through laboratory experiments to understand the significance of voltage reduction. This means to verify the effect of voltage reduction on extinguishing or minimizing PD activity in cables. In this paper, range of voltages at which PD incepts termed as partial discharge inception voltage(PDIV) is measured using a test cell containing different types of electrode configuration having different spacing. PDIV measured using the test cell is verified by conducting partial discharge testing in paper insulated lead covered (PILC) and cross-linked poly ethylene(XLPE) cables. It has been found that PDIV measured using the test cell and cable are in good agreement