Abstract

This study investigates the genetic basis of familial hypercholesterolemia (FH) in selected Libyan patients in Tripoli, focusing on variants associated with mutations in exon 12 of the low-density lipoprotein receptor (LDL-R) gene on chromosome 19. Genetic analysis was performed using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) based on DNA techniques to detect splicing defects of the LDL-R gene in exon 12. Participants were recruited from the Tajoura National Cardiac Center and the Endocrine and Diabetic Hospital in Tripoli. The results revealed the presence of the splicing defect (c.1845+11C>G) in exon 12 of the LDL-R gene in patients with hypercholesterolemia and ischemic heart disease, many of whom had a family history of hypercholesterolemia and other contributing factors such as diabetes, hypertension, chest pain, and obesity. The frequency of heterozygous FH patients in the sample was 0.86%, with statistical analysis showing {p-value > 0.05}, which is considered high according to clinical diagnostic criteria. In addition, the study detected the single nucleotide polymorphism (SNP) (1773C>T), which alters exon splicing efficiency and is linked to emerging functional genetic variants in exon 12. Molecular diagnosis confirmed that LDL-R gene mutations are strongly associated with premature coronary artery disease (P-CAD).

Abstract

This paper aims to summarize the reality of the Libyan agricultural sector from 1969 to 2007 by showing the development of agricultural production, performance of the agricultural sector, challenges, problems and constraints of agriculture in Libya. Agriculture and livestock have been important components of the Libyan social, political and economic fabric, with more than half the population engaged in agriculture in some form until the 1950s and 1960s. The sector has received generous subsidies in the quest for self-sufficiency. However, the Libyan agricultural growth has been inversely related with growth in the Libyan oil sector. Also, the agricultural sector’s contribution to gross domestic product (GDP) has been declining since the discovery of oil in 1958. According to the Ministry of Agriculture (MoA, 2008) food imports have rapidly increased over recent decades, reaching approximately $270 million in 2007. Cereals contribute the largest share of these imports with 35%; wheat alone representing 6% of total imports in 2007. Apart from limited wheat and barley production, the major agricultural production consists mostly of fruit and vegetables, especially dates, grapes, olives, citrus, watermelon, onions, tomatoes, and potatoes. In short, the agricultural sector still faces many challenges, problems and constraints including limited agricultural resources, and the ability to exploit these resources efficiently. Also, unfortunately, performance of agriculture in Libya has not been up to expectations and has been characterized over the decades by ups and downs. Keywords: Gross Domestic Product (GDP), Agriculture, Agricultural Production.

Abstract

Given a bitopological space , where both and belong to a certain class of topological spaces , we will show that there exist a graph which will give a graphic presentation of the bitopological space . Keywords: Graph; Bitopology; maps; Idempotent. 1. Preliminaries: 1-1. Definition: If is a set, a map is said to be an idempotent map if . 1-2. Lemma: If is any idempotent map, defined by for any , then is a closure operation in the set . Proof: see [1]. 1-3. Definition: If is a non-empty set, is an idempotent map. Let denotes the topology on such that: for any . We call the topology induced by the idempotent map . 1-4. Definition: A space is said to be space if and only if each one-point set is either open or closed in . The following theorem is 1.5.6 of [1]. 1-5. Theorem: If is the topology induced by an idempotent map , then the frontier of any one-point set is either empty or a one-point set. 1-6. Theorem: If is the topology induced by an idempotent map , then is a space.

Abstract

This paper is an experimental study to analyze the performance of Voice Over IP (VoIP) traffic over wired and wireless Local Area Networks (LANs) by observing VoIP Quality Of Service (QoS) parameters, these parameters comprise jitter, delay and packet loss ratio. Two widely deployed LANs technologies (IEEE 802.3Ethernet in wired and IEEE 802.11G in wireless) are chosen as the test environment to conduct this study, the test methodology adopted in this study is based on simulation of real voice traffic in both network environments, thus the study was conducted in the laboratory using real equipment. In order to evaluate VoIP traffic performance, Quality of Service (QoS) parameters on the Real-Time Transport Protocol (RTP) packet transmission under different background traffic loads are measured, File Transport Protocol (FTP) traffic is used as the back ground traffic. A set of graphs representing the jitter and delay graphs versus the RTP packets number are produced. The test results show that at high network loads, VoIP traffic in both network environments suffers high delay and jitter values. Also it shows that performance of VoIP traffic in wireless is much worse than the performance in Ethernet under the same load conditions. In both Ethernet and wireless, it was noticeable that there is a strong linear correlation between RTP packets delay and packet loss ratio.

Abstract

The effect of dilution on clad-stainless steel layers type (SS309L & SS308) deposited by Gas Metal Arc Welding technique was studied. The dilution effect was investigated by metallographic, and corrosion (both weight and electrochemical) techniques. The metallographic test showed that the first layer SS309 L has pitting corrosion and also some indications of brittle sigma phase at the interface between SS 309L & SS308 layers. The corrosion tests both weight loss and electrochemical tests were conducted in a solution of 4.5% NaCl and their results were in agreement with the metallographic results. In the electrochemical test the passivity region was lesser in SS 309L layer than that in SS 308 layer indicating the better corrosion resistance of SS 308 layer than that of SS309L. All tests results approved that SS 308 layer has superior corrosion resistance than SS 309L despite that the SS 309L is the thicker layer and has more Cr & Ni content but apparently these excellent properties were damaged due to the dilution effect.