REED-SOLOMON CODED FREQUENCY-HOPPED PACKET RADIO NETWORKS WITH RECEIVER MEMORY, THROUGHPUT-DELAY ANALYSIS

This paper investigates the performance of frequency hopped packet radio networks which employ a memory at the receiver. The main feature of the memory is that all successive transmissions are utilized for packet reconstruction. Two schemes based on RS codes are investigated. System performance is analyzed in both slotted and unslotted channels. Fixed and adaptive packet lengths are considered. It is demonstrated that it is possible to achieve high throughput even in dense jamming environments

Factors Affecting Information Technology Studentsa Motivation; Case Study: Najran University, Saudi Arabia

The study of computer science and information systems requires commitment and dedication Students must learn above and beyond the standard requirements in order to compete in the job market Hence the motivation is the major driver to accomplish such requirements This paper investigates the possible factors affecting students motivation at Computer Science and Information System College in Najran University To find the best ways to improve student performance academic planning and improve college performance in general was behind the reason for the authors to study the motivation factors Fifty undergraduate students from a computer and information college participated in this research The students completed Academic Intrinsic Motivation Questionnaire MSLQ questionnaires In addition instructors answered interview questions related to factors affecting their students motivation Instructors who participated in seminars and interview believes the English language is the major barrier affecting motivation In addition instructors believes incentives and strict regulation may help improving students motivation Adding to incentives the sense of completion is missing beside no enough recognition from college and instructors The survey results shows students agreed that the Needs and Mastery factors motivate them Whilst the students wasn t able to decide on Power Fear Authority and Peers motivation factors The paper provides recommendations for college leaders and instructors on best ways to improve students motivation in order to reach better performanc

Effect of Phenobarbitone Treatment Against Signal Grass (Brachiaria decumbens) Toxicity in Sheep

The effect of phenobarbitone against signal grass (Brachiaria decumbens) toxicity was studied in 26 male crossbred sheep. Grazing on signal grass significantly decreased the concentration of cytochrome P-450 and the activity of drug metabolizing enzymes, viz. aminopyrine-N-demethylase, aniline-4-hydroxylase, UDP- glucuronyltransferase and glutathione-S-transferase in liver and kidneys of affected sheep. Oral administration of phenobarbitone (30 mg/kg body weight) for five consecutive days before grazing on B. decumbens pasture, and thereafter, for three consecutive days every two weeks, resulted in significant increases in hepatic and renal activities of drug-metabolizing enzymes. The induction of drug metabolizing activity in sheep grazing on signal grass group was found to be lower than in animals given phenobarbitone alone. Induction by phenobarbitone provided a degree of protection against the toxic effects of B. decumbens as indicated by the delay in the appearance of signs of toxicity. Furthermore, these were much milder compared to those in the sheep not treated with phenobarbitone. The present study suggests that phenobarbitone-type cytochrome P-450 isoenzyme-induction may increase resistance against signal grass (B. decumbens) toxicity in sheep

In vitro antiproliferative and antioxidant activities of the extracts of Muntingia calabura leaves.

The in vitro antiproliferative and antioxidant activities of the aqueous, chloroform and methanol extracts of Muntingia calabura leaves were determined in the present study. Assessed using the 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay, the aqueous and methanol extracts of M. calabura inhibited the proliferation of MCF-7, HeLa, HT-29, HL-60 and K-562 cancer cells while the chloroform extract only inhibited the proliferation of MCF-7, HeLa, HL-60 and K-562 cancer cells. Interestingly, all extracts of M. calabura, which failed to inhibit the MDA-MB-231 cells proliferation, did not inhibit the proliferation of 3T3 (normal) cells, indicating its safety. All extracts (20, 100 and 500 μg/ml) were found to possess antioxidant activity when tested using the DPPH radical scavenging and superoxide scavenging assays with the methanol, followed by the aqueous and chloroform, extract exhibiting the highest antioxidant activity in both assays. The total phenolic content for the aqueous, methanol and chloroform extracts were 2970.4 ± 6.6, 1279.9 ± 6.1 and 2978.1 ± 4.3 mg/100 g gallic acid, respectively. In conclusion, the M. calabura leaves possess potential antiproliferative and antioxidant activities that could be attributed to its high content of phenolic compounds, and thus, needs to be further explored

Handlebar Hernia: A Rare Type of Abdominal Wall Hernia

Handlebar hernias are abdominal wall hernias resulting from direct trauma to the anterior abdominal wall. They usually result at weak anatomic locations of the abdominal wall. Such traumatic hernias are rare, requiring a high index of suspicion for a clinical diagnosis. We report the case of a handlebar hernia resulting from an injury sustained during a vehicular injury, and discuss the management of such injuries