An ensemble model to detect packet length covert channels

Covert channel techniques have enriched the way to commit dangerous and unwatched attacks. They exploit ways that are not intended to convey information; therefore, traditional security measures cannot detect them. One class of covert channels that difficult to detect, mitigate, or eliminate is packet length covert channels. This class of covert channels takes advantage of packet length variations to convey covert information. Numerous research articles reflect the useful use of machine learning (ML) classification approaches to discover covert channels. Therefore, this study presented an efficient ensemble classification model to detect such types of attacks. The ensemble model consists of five machine learning algorithms representing the base classifiers. The base classifiers include naive Bayes (NB), decision tree (DT), support vector machine (SVM), k-nearest neighbor (KNN), and random forest (RF). Whereas, the logistic regression (LR) classifier was employed to aggregate the outputs of the base classifiers and thus to generate the ensemble classifier output. The results showed a good performance of our proposed ensemble classifier. It beats all single classification algorithms, with a 99.3% accuracy rate and negligible classification errors

Effects of Irrigation Interval, Nitrogen and Phosphorus on Grain Yield and biomass of Wheat

This study was conducted for two successive seasons of 1998/1999 and 1999/2000, at the Gezira Research Station Farm, Agricultural Research Corporation, Sudan, to investigate the effects of irrigation interval, nitrogen and phosphorus levels on wheat (Triticum aestivum L.( yield and yield components. The study consisted of three irrigation intervals (7,14,21 days), three N levels (0, 43 and 86 kg N/ha) and two P levels (0 and 43 kg P205/ha). Treatments were arranged in a split-split plot design with three replications. Results showed that the irrigation intervals of 7 and 14 days had positive effects on wheat grain and total dry matter yield as compared to the 21 days irrigation interval which negatively affected these parameters. Plants of the latter treatment were dwarf with thin stems and matured earlier resulting in low grain and biomass yields. The study, also, showed that the highest wheat yield was obtained with the application of N and P at the rates of 86 kg N and 43 kg P2O5/ha, respectively, with the irrigation interval of 7 days. &nbsp

Sustainable and Stable Clay Sand Liners over Time

The washout of fine materials from liners consisting of clay–sand mixtures is expected to influence the hydraulic conductivity. Clay sand liners must be assessed for efficiency when initially subjected to flood or standing water as the wetting under a hydraulic gradient can cause fine material to move and migrate away from the mixture. During wetting and drying complex expansion and shrinkage, changes take place. These changes affect the hydraulic conductivity and are likely to go out of the design range set out for the facility. The research covers the behavior of two clay sand liners tested over an extended time. The hydraulic conductivity measured under a specific hydraulic gradient was measured continuously following the establishment of the test set-up. Self-recording sensors were used to measure the temperature during the tests. The results indicated that the hydraulic conductivity reduces after an initial period of increase and fluctuation caused by the loss of mass because of fine material migration and swelling initiated due to the high content of smectite minerals. The testing and monitoring continued for more than 400 days. The permanent reduction in the hydraulic conductivity occurs after the initial period of repeated rise and fall. The extent of the initial period for the two tested mixtures is subject to the fine content mass and the clay mineralogy. The continuous reduction in the hydraulic conductivity after the initial period is due to the rearrangement of particles and compression in the sand–clay mixture

Predicting Hydraulic Conductivity for Flexible Wall Conditions Using Rigid Wall Permeameter

The hydraulic conductivity is known as the soil properties that mostly vary over an order of magnitude. There are many laboratory test methods to determine the hydraulic conductivity of the soil. Each test has its own merits, drawbacks and limitations. One of these methods is the measurement using a rigid wall permeameter (RWP), which is a common practice to obtain the fluid transmissibility characteristics of the soil matrix. This type of permeameter has the advantages of low cost, simplicity of test equipment, and adaptability to many different types of permeant liquids. Another method is the measurement through a flexible wall permeameter (FWP). The hydraulic conductivity measured using the FWP is conducted in a confined cylinder in which water flow is forced into one direction. The main disadvantage of this type is being relatively more expensive and needs more time to perform the test compared to the RWP. This study is aimed at comparing three testing conditions to obtain an adjustment factor for the hydraulic conductivity test normally carried out in practice in order to cut down the time needed to perform the test as well as its cost. Different mixtures of sand and expansive clay addition were considered to examine the effect of expansive clay content on the values of the hydraulic conductivity. Tests results revealed that the clay content had a significant effect on the swelling potential, which was attributed to structural changes in the mixtures. The hydraulic conductivity of mixtures decreases with the increase in clay content. The hydraulic conductivity of mixtures tested using FWP was observed to be lower than that of mixtures tested using RWP at similar clay contents. The tests conducted enabled establishing a correction factor to adjust the hydraulic conductivity normally obtained in practice using rigid wall cells

Risk factors for peritoneal dialysis catheter failure in children

Background Peritoneal dialysis catheter (PDC) failure still remains a common clinical problem in pediatric patients despite advancements in catheter placement and dialysis techniques. Our aim was to determine the risk factors that may lead to PDC failure, especially those factors that could be potentially modified to minimize PDC failures. Patients and methods This study was designed as a retrospective chart review of 31 patients less than 12 years of age who had end-stage renal disease (ESRD) on whom a total of 54 operative PDC placements were carried out at the tertiary Children’s Hospital, King Fahad Medical City, Riyadh, Saudi Arabia, from January 2007 to December 2010. The data included patient demographics and perioperative and operative variables. Results Fifty-four PDCs were inserted in 31 pediatric patients with ESRD, of whom 17 (55%) were boys and 14 (45%) were girls. Young age showed a statistically significant effect on PDC failure [1.8 (± 5) vs. 5 (± 7.8), P = 0.007], whereas weight did not (P = 0.085). Five types of PDCs were used, which showed significant association with PDC failure (P =0.009). Supraumbilical paramedian abdominal entry incisions were used in 49 (90.7%) patients without peritoneal leakage in any case. Nonsimultaneous omentectomy and upward PDC exit site orientation showed significant association with PDC failure (Pr0.001). The causes of PDC failure included idiopathic peritonitis in 13 (56.5%), PDC occlusion by omentum in five (21.7%), PDC malposition in four (17.4%) patients, and PDC leakage in one (4.4%) patient. Peritonitis showed a high statistical significance in PDC failure with P value of less than 0.001. The serum albumin level at the time of PDC insertion was not statistically significant in terms of PDC failure (P = 0.40) but had a high association with idiopathic peritonitis. Conclusion Our study provides some recommendations to minimize PDC failures that include improvement of patients’ nutritional status, use of a swan-neck double-cuffed catheter, paramedian abdominal entry incision, simultaneous omentectomy, downward orientation of exit site, and use of an up-to-date technique by a dedicated team for proper use of PDC. However, prospective studies possibly on a multicentric basis are necessary to standardize the best PDC insertion and maintenance techniques to minimize PDC failures and improve the quality of life for children with ESRD

Functional alterations due to amino acid changes and evolutionary comparative analysis of ARPKD and ADPKD genes

A targeted customized sequencing of genes implicated in autosomal recessive polycystic kidney disease (ARPKD) phenotype was performed to identify candidate variants using the Ion torrent PGM next-generation sequencing. The results identified four potential pathogenic variants in PKHD1 gene [c.4870C>T, p.(Arg1624Trp), c.5725C>T, p.(Arg1909Trp), c.1736C>T, p.(Thr579Met) and c.10628T>G, p.(Leu3543Trp)] among 12 out of 18 samples. However, one variant c.4870C>T, p.(Arg1624Trp) was common among eight patients. Some patient samples also showed few variants in autosomal dominant polycystic kidney disease (ADPKD) disease causing genes PKD1 and PKD2 such as c.12433G>A, p.(Val4145Ile) and c.1445T>G, p.(Phe482Cys), respectively. All causative variants were validated by capillary sequencing and confirmed the presence of a novel homozygous variant c.10628T>G, p.(Leu3543Trp) in a male proband. We have recently published the results of these studies (Edrees et al., 2016). Here we report for the first time the effect of the common mutation p.(Arg1624Trp) found in eight samples on the protein structure and function due to the specific amino acid changes of PKHD1 protein using molecular dynamics simulations. The computational approaches provide tool predict the phenotypic effect of variant on the structure and function of the altered protein. The structural analysis with the common mutation p.(Arg1624Trp) in the native and mutant modeled protein were also studied for solvent accessibility, secondary structure and stabilizing residues to find out the stability of the protein between wild type and mutant forms. Furthermore, comparative genomics and evolutionary analyses of variants observed in PKHD1, PKD1, and PKD2 genes were also performed in some mammalian species including human to understand the complexity of genomes among closely related mammalian species. Taken together, the results revealed that the evolutionary comparative analyses and characterization of PKHD1, PKD1, and PKD2 genes among various related and unrelated mammalian species will provide important insights into their evolutionary process and understanding for further disease characterization and management

The educational value of ward rounds as a learning and teaching opportunity for house officers, medical officers, and registrars in Sudanese hospitals: a multi-center cross-sectional study

Abstract Background Ward rounds are a cornerstone in the educational experience of junior doctors and an essential part of teaching patient care. Here, we aimed to assess the doctors’ perception of ward rounds as an educational opportunity and to identify the obstacles faced in conducting a proper ward round in Sudanese hospitals. Method A cross-sectional study was conducted from the 15th to the 30th of January 2022 among house officers, medical officers, and registrars in about 50 teaching and referral hospitals in Sudan. House officers and medical officers were considered the learners, while specialist registrars were considered the teachers. Doctors’ perceptions were assessed using an online questionnaire, with a 5-level Likert scale to answer questions. Results A total of 2,011 doctors participated in this study (882 house officers, 697 medical officers, and 432 registrars). The participants were aged 26.9 ± 3.2 years, and females constituted about 60% of the sample. An average of 3.1 ± 6.8 ward rounds were conducted per week in our hospitals, with 11.1 ± 20.3 h spent on ward rounds per week. Most doctors agreed that ward rounds are suitable for teaching patient management (91.3%) and diagnostic investigations (89.1%). Almost all the doctors agreed that being interested in teaching (95.1%) and communicating appropriately with the patients (94.7%) make a good teacher in ward rounds. Furthermore, nearly all the doctors agreed that being interested in learning (94.3%) and communicating appropriately with the teacher (94.5%) make a good student on ward rounds. About 92.8% of the doctors stated that the quality of ward rounds could be improved. The most frequently reported obstacles faced during ward rounds were the noise (70%) and lack of privacy (77%) in the ward environment. Conclusion Ward rounds have a special value in teaching patient diagnosis and management. Being interested in teaching/learning and having good communication skills were the two major criteria that make a good teacher/learner. Unfortunately, ward rounds are faced with obstacles related to the ward environment. It is mandatory to ensure the quality of both ward rounds' teaching and environment to optimize the educational value and subsequently improve patient care practice