Parallel Database Architectures: A Simulation Study.

Parallel database systems are gaining popularity as a solution that provides scalability in large and growing databases. A parallel database system is a DBS which exploits multiprocessing systems to improve performance. Parallel database computers can be classified into three categories: shared memory, shared disk, and shared nothing. In shared memory, all resources, including main memory and disk units, are shared among several processors. In shared disk, a group of processors share a common pool of disks, but each processor has its own private main memory. In the shared-nothing system, every processor has its own memory and disk unit, that is, except for communication links, no resources are shared among the processors. In this work, we· compare the performance of the three architecture classes. Simulation models for the various architectures are introduced. Using these models, a number of experiments were conducted to compare the system performance of these architectures under different workloads and transaction models. The aim of this work is to provide a tool for evaluating the different architectures and their appropriateness for a specific database application

Multicast Services for Multimedia Collaborative Applications

This work aims at providing multicast services for multimedia collaborative applications over large inter-networks such as the Internet. Multimedia collaborative applications are typically of small group size, slow group membership dynamics, and awareness of participants\u27 identities and locations. Moreover, they usually consist of several components such as audio, video, shared whiteboard, and single user application sharing engines that collectively help make the collaboration session successful. Each of these components has its demands from the communication layer that may differ from one component to another. This dissertation identifies the overall characteristics of multimedia collaborative applications and their individual components. It also determines the service requirements of the various components from the communication layer. Based on the analysis done in the thesis, new techniques of multicast services that are more suitable for multimedia collaborative applications are introduced. In particular, the focus will be on multicast address management and connection control, routing, congestion and flow control, and error control. First, we investigate multicast address management and connection control and provide a new technique for address management based on address space partitioning. Second, we study the problem of multicast routing and introduce a new approach that fits the real time nature of multimedia applications. Third, we explore the problem of congestion and flow control and introduce a new mechanism that takes into consideration the heterogeneity within the network and within the processing capabilities of the end systems. Last, we exploit the problem of error control and present a solution that supports various levels of error control to the different components within the collaboration session. We present analytic as well as simulation studies to evaluate our work, which show that our techniques outperform previous ones

Fault location using line impedance with the presence of ARC resistance

Many methods were developed to identify the estimated location of faults in distribution systems. They are either dealing with the travelling waves generated by faults at high frequencies or using the fundamental frequency components. Among them "Fault Impedance Methods" are the most popular, but their accuracy is affected by the presence of fault resistances and the presence of arcs. In this project, PSCAD is used for simulating several types of faults, focusing in three lines to ground faults with different cases, including faults with and without fault resistance in addition to faults with arc. The fault impedance method code that improved to consider the presence of arcs and its resistance and implemented using MATLAB programming environment is used to estimate the fault location for the previous cases. As expected, the method is sensitive to the presence of fault resistance and fault arcs. However, the improved method achieved good results for faults with arcs at distances higher than 15 Ian and slightly improved results for shorter distances

Role of Urinary Catheter in Post-Partum Urinary Retention and Genitourinary Infections in Caesarean Deliveries

Background: Urethral catheterization is done as a routine procedure in cesarean section. It is thought to be associated with high incidence of urinary tract infections, discomfort, delayed ambulation and longer hospital stay. The aim of our study were to determine the feasibility and safety of cesarean section without urethral catheterization. Subjects and Methods: A prospective, randomized controlled trial was carried out in Beni-Suef General Hospital from April 1, 2014 to April 1, 2015April. Among 100 patients who had undergone cesarean section 50 were catheterized and 50 were uncatheterized. Results: The study showed that the catheterized group took longer time till first voiding 7.80+ 2.88 hours versus 6.72+ 2.27 hours for the uncatheterized group (p value = 0.04*) and also took longer time till first ambulation 8.64+ 2.62 hours versus 6.10+ 1.94 hours for the uncatheterized group (p value = 0.001*). Further ,the females who were catheterized stayed for much longer period at hospital 30.56+6.19 hours versus 20.46+2.92 hours for the uncatheterized group (p value = 0.001*). The catheterized group had much higher numbers of UTI among its females, 36 female compared to only 15 females of the uncatheterized group (p value= 0.001*). Fmales who were subjected to catheterization were more likely to show urinary retention (p value = 0.039*). Conclusion: Cesarean section can be done safely without urethral catheterization with reduced morbidities. Keywords: Cesarean section, Urethral catheterization, Urinary tract infection, Urinary retentio

Determination of Best Refractories Suitable for Glass Forming Molds by Manual Blowing

Refractories are characterized by their ability to withstand high temperatures that reach 2800°C, their ability to withstand sudden changes in temperature, resist mechanical shocks, due to the formation of glass at a temperature of 1050-1100°C, it is required that the molds manufactured from refractories withstand that temperature. This is in addition to the ability of the refractory material to show the fine details and the prominent and recessed sculptural surfaces (smooth - rough) in the glass product, and to achieve the uniqueness and excellence of the glass product.This is due to the requirements of refractory mold in its manufacture and assortment with manual blowing in terms of its ability to withstand pressures, non-fragmentation, thermal endurance that reaches (1500 - 1750°C), and a low rate of expansion and contraction that reaches ± 0.05 mm, as well as its flat smoothness, which is considered as a mirror of a model formation.Since the glass material is acidic, it requires that the components of the refractory composition of the mold be acidic or neutral as well. To prevent the adhesion with the glass components thus, some refractories were selected that enter into the work of refractory formulations that can achieve chemical and natural properties suitable in the manufacture of glass forming molds by manual blowing. (16) Refractory compositions were made, and the research reached to find new refractories that meet the requirements. Thus, it is recommended to use refractories for producing the prototype of the glass products which are characterized by aesthetic products

Contact osteogenesis by biodegradable 3D-printed poly(lactide-co-trimethylene carbonate)

Background To support bone regeneration, 3D-printed templates function as temporary guides. The preferred materials are synthetic polymers, due to their ease of processing and biological inertness. Poly(lactide-co-trimethylene carbonate) (PLATMC) has good biological compatibility and currently used in soft tissue regeneration. The aim of this study was to evaluate the osteoconductivity of 3D-printed PLATMC templates for bone tissue engineering, in comparison with the widely used 3D-printed polycaprolactone (PCL) templates. Methods The printability and physical properties of 3D-printed templates were assessed, including wettability, tensile properties and the degradation profile. Human bone marrow-derived mesenchymal stem cells (hBMSCs) were used to evaluate osteoconductivity and extracellular matrix secretion in vitro. In addition, 3D-printed templates were implanted in subcutaneous and calvarial bone defect models in rabbits. Results Compared to PCL, PLATMC exhibited greater wettability, strength, degradation, and promoted osteogenic differentiation of hBMSCs, with superior osteoconductivity. However, the higher ALP activity disclosed by PCL group at 7 and 21 days did not dictate better osteoconductivity. This was confirmed in vivo in the calvarial defect model, where PCL disclosed distant osteogenesis, while PLATMC disclosed greater areas of new bone and obvious contact osteogenesis on surface. Conclusions This study shows for the first time the contact osteogenesis formed on a degradable synthetic co-polymer. 3D-printed PLATMC templates disclosed unique contact osteogenesis and significant higher amount of new bone regeneration, thus could be used to advantage in bone tissue engineering.publishedVersio

Longitudinal changes in peri-papillary retinal nerve fiber layer thickness in patients with unilateral branch retinal vein occlusion

Background: Associations between retinal venous occlusion (RVO), elevated intraocular pressure, and glaucoma have been reported. Further investigations into structural alterations in the fellow eyes of individuals with unilateral RVO have revealed that the peripapillary retinal nerve fiber layer is thinner than in healthy eyes, suggesting that there may be systemic risk factors common to both RVO and glaucoma. We aimed to evaluate changes in peripapillary retinal nerve fiber layer thickness (pRNFLT) among individuals with unilateral branch retinal vein occlusion (BRVO). Methods: This prospective observational study recruited 30 individuals (60 eyes) with newly diagnosed unilateral BRVO and macular edema, and a control group of 30 healthy individuals (30 eyes) with no abnormalities on fundus examination or concurrent systemic comorbidities. After baseline measurements, the participants were reassessed at 6, 12, and 24 months by measuring global and sectoral pRNFLT using spectral-domain optical coherence tomography. Results: The mean age and sex distributions were comparable between the patient and control groups (both P > 0.05). When compared to fellow eyes, global and sectoral pRNFLT in eyes with BRVO were significantly higher at baseline (all P < 0.05). Over time, pRNFLT decreased dramatically, and by the conclusion of the two-year follow-up, there was a significant reduction from baseline in the affected eyes (all P < 0.05). Likewise, affected eyes experienced a significant improvement in best-corrected distance visual acuity and central macular thickness over the two-year follow-up (both P Less than or equal to 0.001). Comparing the global and all-sector pRNFLT of fellow eyes in the patient group with those of normal eyes in the control group, there were no significant differences at any visit, except in the temporal sector, which revealed a significant reduction in pRNFLT at 24 months in the fellow eyes of patients with unilateral BRVO (P = 0.02).   Conclusions: Patients with unilateral BRVO experienced a significant reduction in pRNFLT in the affected eyes and, to a lesser extent, in the fellow eyes, compared with that of the control arm, suggesting that they are prone to retinal nerve fiber layer damage. The reduction in pRNFLT in the normal fellow eyes of patients with BRVO may be attributed to age or concurrent systemic comorbidities. Further studies with long follow-up periods are required to shed light on the etiology of functional and structural changes in both the retinal nerve fiber layer and ganglion cell complex in the normal and affected eyes of patients with unilateral BRVO

Medication Sector in Qatar: Hand in Hand Facing the Blockade

Conference agend

Impact of Anisakis pegreffi Infection on Gonadal Health and Gonadosomatic Index of European Hake (Merluccius merluccius)

Parameters belonging to the physical status and gonadal size of certain fish provide crucial information for assessing both the productivity and fecundity of declining fish populations. These parameters are vulnerable to the negative impacts of disease agents such as internal or systemic parasites. Although parasitic diseases might influence these parameters, the literature investigating these pathophysiological alterations is scanty. Therefore, the current study represents one of the scarcest studies that document the possible link between parasitism, gonadal health, and the growth of European hake (Merluccius merluccius). Screening of imported European halves indicated a relatively high prevalence of Anisakis pegreffi Larvae 3 infestation, with an 80% prevalence rate, a mean intensity of 24.4, and a mean abundance of 19.5. However, the prevalence of Anisakid larvae infection in native fish was 36% with a mean intensity of 7.36 and mean abundance of 2.65.The current research revealed remarkable ovarian pathology that involved several forms of degenerative changes in ovarian tissues. Such gonadal pathologies were attributed to the damaging effect of the retrieved Anisakis pegreffi Larvae 3. Gonadosomatic index of both heavily infected imported / native hakes was relatively impacted by the progressive gonadal pathology resulting from Anisakis pegreffi L3 infection. Morphometric measurements of the gonads and body have revealed that, gonadosomatic index of both heavily infected imported / native hakes was relatively impacted by the progressive gonadal pathology resulting from Anisakis pegreffi L3 infection

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London