210 research outputs found

    A Survey of Limitations and Enhancements of the IPv6 Routing Protocol for Low-power and Lossy Networks: A Focus on Core Operations

    Get PDF
    Driven by the special requirements of the Low-power and Lossy Networks (LLNs), the IPv6 Routing Protocol for LLNs (RPL) was standardized by the IETF some six years ago to tackle the routing issue in such networks. Since its introduction, however, numerous studies have pointed out that, in its current form, RPL suffers from issues that limit its efficiency and domain of applicability. Thus, several solutions have been proposed in the literature in an attempt to overcome these identified limitations. In this survey, we aim mainly to provide a comprehensive review of these research proposals assessing whether such proposals have succeeded in overcoming the standard reported limitations related to its core operations. Although some of RPL’s weaknesses have been addressed successfully, the study found that the proposed solutions remain deficient in overcoming several others. Hence, the study investigates where such proposals still fall short, the challenges and pitfalls to avoid, thus would help researchers formulate a clear foundation for the development of further successful extensions in future allowing the protocol to be applied more widely

    Effects of Lipoic Acid Supplementation on Activities of Cyclooxygenases and Levels of Prostaglandins E 2 and F 2 Metabolites, in the Offspring of Rats with Streptozotocin-Induced Diabetes

    Get PDF
    Background. Our aim was to evaluate the protective effect of lipoic acid (LA) on fetal outcome of diabetic mothers. Methods. Diabetes was induced in female rats using streptozotocin and rats were made pregnant. Pregnant control (group 1; = 9; and group 2; = 7) or pregnant diabetic (group 3; = 10; and group 4; = 8) rats were treated daily with either LA (groups 2 and 4) or vehicle (groups 1 and 3) between gestational days 0 and 15. On day 15 of gestation, the fetuses, placentas, and membranes were dissected, examined morphologically, and then homogenized, to measure cyclooxygenase (COX) activities and metabolisms of prostaglandin (PG) E 2 (PGEM) and PGF 2 (PGFM) levels. The level of total glutathione was measured in the maternal liver and plasma and in all fetuses. Results. Supplementation of diabetic rats with LA was found to significantly ( < 0.05) reduce resorption rates in diabetic rats and led to a significant ( < 0.05) increase in liver, plasma, and fetuses total glutathione from LA-TD rats as compared to those from V-TD. Decreased levels of PGEM and elevated levels of PGFM in the fetuses, placentas, and membranes were characteristic of experimental diabetic gestation associated with malformation. The levels of PGEM in malformed fetuses from LA-TD mothers was significantly ( < 0.05) higher than those in malformed fetuses from V-TD rats. Conclusions. LA treatment did not completely prevent the occurrence of malformations. Thus, other factors may be involved in the pathogenesis of the diabetesinduced congenital malformations

    A Novel Chaotic Permutation-Substitution Image Encryption Scheme Based on Logistic Map and Random Substitution

    Get PDF
    Privacy is a serious concern related to sharing videos or images among people over the Internet. As a method to preserve images’ privacy, chaos-based image encryption algorithms have been used widely to fulfil such a requirement. However, these algorithms suffer from a low key-space, significant computational overhead, and a lag in resistance against differential attacks. This paper presents a novel chaos-based image encryption method based on permutation and substitution using a single Substitution Box (S-Box) to address issues in contemporary image encryption algorithms. The proposed encryption technique’s efficiency is validated through extensive experiments as compared to the state-of-the-art encryption algorithms using different measures and benchmarks. Precisely, the collected results demonstrate that the proposed technique is more resilient against well-known statistical attacks and performs well under plaintext attacks. Indeed, the proposed scheme exhibits very high sensitivity concerning the plaintext attack. A minor change in the encryption key or the plain text would result in a completely different encrypted image

    Egyptian consensus on treat-to-target approach for osteoporosis: a clinical practice guideline from the Egyptian Academy of bone health and metabolic bone diseases

    Get PDF
    Background: This study was carried out to achieve an Egyptian expert consensus on a treat-to-target managementstrategy for osteoporosis using Delphi technique. A scientific committee identified researchers and clinicians with expertise in osteoporosis in Egypt. Delphi process was implemented (2 rounds) to establish a consensus on 15 clinical standards: (1) concept, (2) diagnosis, (3) case identification, (4) whom to treat, (5) who should treat?, (6) case stratification and intervention thresholds, (7) falls risk, (8) investigations, (9) treatment target, (10) management, (11) optimum treatment duration, (12) monitoring, (13) drug holiday, (14) osteoporosis in men, and (15) post-fracture care and fracture liaison service. Results: The surveys were sent to an expert panel (n = 25), of whom 24 participated in the two rounds. Respondents were drawn from different governorates and health centres across Egypt including the Ministry of Health. Most of the participants were rheumatologists (76%), followed by internists (8%), orthopaedic doctors (4%), rehabilitation doctors (4%), primary care (4%), and ortho-geriatrics (4%) physicians. Seventy-two recommendations, categorised into 15 sections, were obtained. Agreement with the recommendations (rank 7–9) ranged from 83.4 to 100%. Consensus was reached (i.e. ≥ 75% of respondents strongly agreed or agreed) on the wording of all 15 clinical standards identified by the scientific committee. An algorithm for the management of postmenopausal osteoporosis has been suggested. Conclusion: A wide and representative panel of experts established a consensus regarding the management of osteoporosis in Egypt. The developed guidelines provide a comprehensive approach to the assessment and management of osteoporosis for all Egyptian healthcare professionals who are involved in its management

    An adaptive behavioral-based incremental batch learning malware variants detection model using concept drift detection and sequential deep learning

    Get PDF
    Malware variants are the major emerging threats that face cybersecurity due to the potential damage to computer systems. Many solutions have been proposed for detecting malware variants. However, accurate detection is challenging due to the constantly evolving nature of the malware variants that cause concept drift. Existing malware detection solutions assume that the mapping learned from historical malware features will be valid for new and future malware. The relationship between input features and the class label has been considered stationary, which doesn't hold for the ever-evolving nature of malware variants. Malware features change dynamically due to code obfuscations, mutations, and the modification made by malware authors to change the features' distribution and thus evade the detection rendering the detection model obsolete and ineffective. This study presents an Adaptive behavioral-based Incremental Batch Learning Malware Variants Detection model using concept drift detection and sequential deep learning (AIBL-MVD) to accommodate the new malware variants. Malware behaviors were extracted using dynamic analysis by running the malware files in a sandbox environment and collecting their Application Programming Interface (API) traces. According to the malware first-time appearance, the malware samples were sorted to capture the malware variants' change characteristics. The base classifier was then trained based on a subset of historical malware samples using a sequential deep learning model. The new malware samples were mixed with a subset of old data and gradually introduced to the learning model in an adaptive batch size incremental learning manner to address the catastrophic forgetting dilemma of incremental learning. The statistical process control technique has been used to detect the concept drift as an indication for incrementally updating the model as well as reducing the frequency of model updates. Results from extensive experiments show that the proposed model is superior in terms of detection rate and efficiency compared with the static model, periodic retraining approaches, and the fixed batch size incremental learning approach. The model maintains an average of 99.41% detection accuracy of new and variants malware with a low updating frequency of 1.35 times per month

    Zebrafish Krüppel-Like Factor 4a Represses Intestinal Cell Proliferation and Promotes Differentiation of Intestinal Cell Lineages

    Get PDF
    BACKGROUND:Mouse krüppel-like factor 4 (Klf4) is a zinc finger-containing transcription factor required for terminal differentiation of goblet cells in the colon. However, studies using either Klf4(-/-) mice or mice with conditionally deleted Klf4 in their gastric epithelia showed different results in the role of Klf4 in epithelial cell proliferation. We used zebrafish as a model organism to gain further understanding of the role of Klf4 in the intestinal cell proliferation and differentiation. METHODOLOGY/PRINCIPAL FINDINGS:We characterized the function of klf4a, a mammalian klf4 homologue by antisense morpholino oligomer knockdown. Zebrafish Klf4a shared high amino acid similarities with human and mouse Klf4. Phylogenetic analysis grouped zebrafish Klf4a together with both human and mouse Klf4 in a branch with high bootstrap value. In zebrafish, we demonstrate that Klf4a represses intestinal cell proliferation based on results of BrdU incorporation, p-Histone 3 immunostaining, and transmission electron microscopy analyses. Decreased PepT1 expression was detected in intestinal bulbs of 80- and 102-hours post fertilization (hpf) klf4a morphants. Significant reduction of alcian blue-stained goblet cell number was identified in intestines of 102- and 120-hpf klf4a morphants. Embryos treated with γ-secretase inhibitor showed increased klf4a expression in the intestine, while decreased klf4a expression and reduction in goblet cell number were observed in embryos injected with Notch intracellular domain (NICD) mRNA. We were able to detect recovery of goblet cell number in 102-hpf embryos that had been co-injected with both klf4a and Notch 1a NICD mRNA. CONCLUSIONS/SIGNIFICANCE:This study provides in vivo evidence showing that zebrafih Klf4a is essential for the repression of intestinal cell proliferation. Zebrafish Klf4a is required for the differentiation of goblet cells and the terminal differentiation of enterocytes. Moreover, the regulation of differentiation of goblet cells in zebrafish intestine by Notch signaling at least partially mediated through Klf4a

    The contemporary management accounting practices adoption in the public industry: Evidence from Jordan

    Get PDF
    The present study examines the effect of variables on contemporary management accounting practices' adoption in the public sector. The present research further investigates the relationship between the uptake of contemporary management accounting practices and organizational performance and change. 520 surveys were mailed to the public sector in Jordan to gather data, which was subsequently analyzed employing SEM. The findings of the research indicate that there are substantial relationships between accounting staff qualifications and management accounting practices. Results indicate that modern management accounting practices could help public sector practitioners enhance performance and promote organizational change. The investigation offers concrete insight into the public sector's uptake of management accounting practices. The research conducted offers a field study of the impact of implementing a suite of management accounting practices in the public sector

    Pathogenic variants in THSD4, encoding the ADAMTS-like 6 protein, predispose to inherited thoracic aortic aneurysm

    Get PDF
    Purpose Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening disease with often unrecognized inherited forms. We sought to identify novel pathogenic variants associated with autosomal dominant inheritance of TAAD. Methods We analyzed exome sequencing data from 35 French TAAD families and performed next-generation sequencing capture panel of genes in 1114 unrelated TAAD patients. Functional effects of pathogenic variants identified were validated in cell, tissue, and mouse models. Results We identified five functional variants inTHSD4of which two heterozygous variants lead to a premature termination codon.THSD4encodes ADAMTSL6 (member of the ADAMTS/L superfamily), a microfibril-associated protein that promotes fibrillin-1 matrix assembly. TheTHSD4variants studied lead to haploinsufficiency or impaired assembly of fibrillin-1 microfibrils.Thsd4(+/-)mice showed progressive dilation of the thoracic aorta. Histologic examination of aortic samples from a patient carrying aTHSD4variant and fromThsd4(+/-)mice, revealed typical medial degeneration and diffuse disruption of extracellular matrix. Conclusion These findings highlight the role of ADAMTSL6 in aortic physiology and TAAD pathogenesis. They will improve TAAD management and help develop new targeted therapies

    Medication errors in the Middle East countries: a systematic review of the literature

    Get PDF
    Background: Medication errors are a significant global concern and can cause serious medical consequences for patients. Little is known about medication errors in Middle Eastern countries. The objectives of this systematic review were to review studies of the incidence and types of medication errors in Middle Eastern countries and to identify the main contributory factors involved. Methods: A systematic review of the literature related to medication errors in Middle Eastern countries was conducted in October 2011 using the following databases: Embase, Medline, Pubmed, the British Nursing Index and the Cumulative Index to Nursing & Allied Health Literature. The search strategy included all ages and languages. Inclusion criteria were that the studies assessed or discussed the incidence of medication errors and contributory factors to medication errors during the medication treatment process in adults or in children. Results: Forty-five studies from 10 of the 15 Middle Eastern countries met the inclusion criteria. Nine (20%) studies focused on medication errors in paediatric patients. Twenty-one focused on prescribing errors, 11 measured administration errors, 12 were interventional studies and one assessed transcribing errors. Dispensing and documentation errors were inadequately evaluated. Error rates varied from 7.1% to 90.5% for prescribing and from 9.4% to 80% for administration. The most common types of prescribing errors reported were incorrect dose (with an incidence rate from 0.15% to 34.8% of prescriptions), wrong frequency and wrong strength. Computerised physician rder entry and clinical pharmacist input were the main interventions evaluated. Poor knowledge of medicines was identified as a contributory factor for errors by both doctors (prescribers) and nurses (when administering drugs). Most studies did not assess the clinical severity of the medication errors. Conclusion: Studies related to medication errors in the Middle Eastern countries were relatively few in number and of poor quality. Educational programmes on drug therapy for doctors and nurses are urgently needed
    corecore