216 research outputs found
Lock-and-key security : evaluation of Telnet as an authentication method usually associated with dynamic access control lists application
Dans les systèmes sans réseaux de communications ou bien les organisations juste avec intranet, les différentes machines et ressources sont souvent totalement isolées, ou bien accédées juste via l'intranet de l'entreprise; elles sont donc utilisées par les usagers éprouvés et autorisés par l'organisation. Les ressources de l'organisation de nos jours qui sont en réseau, tout en étant interconnectées par l'Internet, sont autrement toujours sujettes aux attaques réseautiques venant d'un nombre illimité d'usagers. Ainsi, dans les environnements informatiques en temps partagé, le système d'exploitation, aussi que d'autres mécanismes de sécurité, protègent les ressources bien que les usagers l'un de l'autre. Une telle protection de sécurité prend lieu par l'établissement de quelques règles d'accès pour les différents types d'utilisateurs. Afin de classifier les utilisateurs et les faire correspondre à leurs règles d'accès selon leurs droits d'accès, l'utilisateur doit s'identifier au processus de sécurité dès sa connexion aux ressources de l'organisation, ce processus est appelé : l'authentification de l'utilisateur. L'authentification de l'utilisateur est une pierre angulaire pour la sécurité réseautique de toutes les organisations, ainsi, c'est un des sujets principaux analysés par cette étude. Ce sujet va être élaboré en plus de détails dans chapitre IV, titré L'authentification de l'utilisateur. Comme le besoin des utilisateurs pour accéder via le Web aux ressources internes de différentes organisations a dernièrement émergé (afin d'accéder aux serveurs internes de leurs lieux de travail ou bien ceux des organisations offrant des différents services web), le besoin d'autoriser les utilisateurs a aussi augmenté (afin de sécuriser un tel accès à distance). Cela va nous amener à analyser l'usage des listes de contrôle d'accès dynamiques. Les listes de contrôle d'accès dynamiques sont des essentiels moyens de sécurité qui permettent à l'utilisateur d'accéder en sécurité aux ressources internes d'une organisation, tout en connectant à distance. Les listes de contrôle d'accès dynamiques dépendent complètement de l'authentification de l'utilisateur comme étant une garantie de sécurité de l'identité de l'utilisateur. Les listes de contrôle d'accès dynamiques vont être décrites en détail dans chapitre II, titré Les listes de contrôle d'accès. D'après Odom (Odom, 2009), Telnet est le protocole d'émulation de terminal standard de la couche d'application dans le TCP/IP empilage. Telnet est utilisé pour la connexion à distance au terminal, permettant les utilisateurs d'accéder aux systèmes distants et d'utiliser les ressources comme si elles étaient connectées à un système local. Telnet est défini dans RFC 854 et sera analysé en détail dans chapitre III comme étant une méthode d'authentification utilisée dans la configuration des listes de contrôle d'accès dynamiques. Les listes de contrôle d'accès dynamiques utilisent souvent Telnet comme une méthode d'authentification des utilisateurs. Cependant, Telnet est caractérisé par un nombre de désavantages de sécurité, ce qui ne peut pas garantir une authentification d'utilisateurs complément sécurisée. Ainsi, l'utilisation de Telnet pour établir le processus de l'authentification de l'utilisateur des listes de contrôle d'accès dynamiques est toujours sujette à exposer les ressources internes de l'organisation à plusieurs menaces et brèches de sécurité. À cause de ces raisons, notre étude a eu lieu afin d'évaluer Telnet comme étant une méthode d'authentification, à élaborer ses avantages et ses inconvénients et à suggérer des méthodes d'authentification alternatives qui peuvent être utilisées dans la configuration des listes de contrôle d'accès dynamiques, afin d'authentifier les utilisateurs à distance. Ainsi, dans chapitre 5, Telnet sera analysé comme étant une méthode d'authentification comparée à d'autres méthodes d'authentification utilisées dans la configuration des listes de contrôle d'accès dynamiques, comme les serveurs d'authentification, incluant TACACS+, RADIUS, DIAMETER et Kerberos. L'étude inclut un nombre important de codes de configuration qui sont spécifiquement développés afin d'appuyer les concepts de sécurité analysés et afin de présenter des directives pour guider les concepteurs des réseaux à faire de bons choix de sécurité, garantissant aux utilisateurs une connexion à distance plus sécurisée.\ud
______________________________________________________________________________ \ud
MOTS-CLÉS DE L’AUTEUR : AAA server comparison, Access Control Lists, Authentication method lists, Authentication server, DIAMETER, Dynamic ACLs Authentication, KERBEROS, Network architecture, Network Security, OSI model, Proxy servers, RADIUS, SSH, Standard ACLs, TACACS+, TCP/IP model, Telnet, VPN
Thyroid dysfunction in systemic lupus erythematosus and rheumatoid arthritis: Its impact as a cardiovascular risk factor
AbstractIntroductionThyroid dysfunction and autoantibodies have been frequently associated with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA).Aim of the workTo assess thyroid function and anti-thyroid antibodies in both diseases and elucidate the effects of the thyroid dysfunction on the clinical parameters, disease activity and cardiovascular risk.Patients and methodsForty SLE and forty RA female patients in addition to twenty controls were included. Free thyroxine (FT3), free triiodothyronine (FT4), thyroid stimulating hormone (TSH), anti-thyroid peroxidase antibodies (TPOabs), anti-thyroglobulin antibodies (TGabs), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), triglycerides (TG), total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL) and intima-media thickness (IMT) were measured. Disease activities were assessed in both diseases. In RA patients, the anti-cyclic citrullinated peptide (anti-CCP) was evaluated.ResultsA significantly higher TSH level was found in SLE patients compared to RA patients and controls. No significant difference was present between the RA patients and controls. Anti-TPOabs and anti-TGabs were more frequently detected in SLE (85% and 55%) compared to RA (50% and 37.5%). Abnormal thyroid function tests were detected in SLE, RA patients and controls in 52.5%, 17.5% and 10%, respectively. Subclinical hypothyroidism was the most common abnormality present followed by clinical hypothyroidism then euthyroid sick syndrome in both SLE and RA patients. A positive anti-CCP and high disease activity score (DAS28) in RA were among the strongest independent determinants of cardiovascular disease.ConclusionThyroid dysfunction is frequent in SLE and RA patients. Those with thyroid dysfunction had increased cardiovascular risk
Soluble Triggering Receptor Expressed on Myeloid Cells-1 as a marker to differentiate septic from aseptic meningitis in children: comparison with procalcitonin and C-reactive protein
Background: Differentiating between septic and aseptic meningitis remains a challenge. Procalcitonin (PCT) was suggested by many researchers as a sensitive marker for early diagnosis of septic meningitis but with varying discriminative power. Triggering receptor expressed on myeloid cells-1 (TREM-1), a neutrophil and monocyte receptor, is up-regulated during infection with potential role during sepsis. Objectives: The aim of this study was to evaluate the diagnostic accuracy of soluble TREM-1 in comparison to PCT and C-reactive protein (CRP) in early diagnosis of septic meningitis and its usefulness to distinguish between septic and aseptic meningitis in children. Study design: Fifty-one children aged 2 to 162 months identified as possible cases of meningitis were included in this case control study. Beside Gram staining, cultures of blood and cerebrospinal fluid (CSF) and latex agglutination test of CSF, CRP, serum PCT and soluble TREM-1 (sTREM-1) measurement was done on admission, and after 48-72 hours of treatment. Results: Septic meningitis was diagnosed in 16 (44%) of the studied cases. Although patients with septic meningitis had a significant increase in serum sTREM-1 and PCT levels at the time of admission (median, 25.2 ng/ml and 79.1ng/ml, respectively) in comparison with patients with aseptic meningitis (4.6 ng/ml and 0.7 ng/ml, respectively) and control group (4.1 ng/ml and 0.3 ng/ml, respectively) (p < 0.0001), sTREM-1 showed significantly higher sensitivity (93.7%) and specificity (94.3%) in the early prediction of sepsis with an area under the Receiver Operator Characteristic (ROC) curve (95% CI) of 0.94 (0.84 - 0.99) at a cutoff value of 12.4 ng/ml. Moreover, sTREM-1 but not PCT or CRP concentration was significantly lower (P=0.007) at admission in patients with poor outcome than in those with good prognosis. Conclusions: Both serum PCT and sTREM-1 are valuable in early distinguishing septic from aseptic meningitis in children but with markedly higher diagnostic discriminatory power for sTREM-1. Moreover, sTREM-1 has a significant value in predicting the prognosis of cases with septic meningitis. Keywords: Soluble Triggering Receptor Expressed on Myeloid Cells-1 – Procalcitonin- C-Reactive Protein - Septic meningitisEgypt J Pediatr Allergy Immunol 2011;9(2):77-8
Parvovirus B19 viremia in children with systemic lupus erythematosus
Background: Parvovirus B19 infection may present with fever, rash, nonerosive arthritis, hepatitis, anemia, thrombocytopenia, leucopenia and positive ANA, B19 infection may be misdiagnosed as new onset systemic lupus erythematosus. At the same time, B19 infection and systemic lupus erythematosus may occur simultaneously in some patients. A casual relationship between B19 infection and classic idiopathic systemic lupus erythematosus has not been demonstrated yet. Objectives: This study was undertaken to investigate the seroprevalence of parvovirus B19 in SLE patients and to search for the different correlates of this viremia with positive results. Methods: This case-control study was conducted on 30 patients with SLE and 30 normal controls. All the children were subjected to detailed medical history, Clinical examination, laboratory estimation as sera from them were examined for parvovirus B19 infection by serological assays using nested polymerase chain reaction and IgG and IgM antiB19 antibodies by ELISA. Results: Parvovirus B19 DNA was detected in 11 of the 30 patients with SLE (33.3 percent) while it was not detected in any of our normal controls. Of the 11 patients with B19 DNA, only two had IgG anti-B19 antibody and one had IgM anti-B19 antibodies, whereas IgG and IgM anti-B19 antibodies were detected in 11(57.8%)and 9 (47.3%)of 19 SLE patients without B19 DNA respectively. B19 DNA was found more commonly in sera from SLE patients without anti-B19 antibodies than in those with anti-B19 antibodies (P < 0.05). Conclusions: parvovirus B19 might induce either idiopathic SLE in a person who is genetically susceptible or it might induce a SLE-like picture. Parvovirus B19 infection in patients with SLE may be due to lack of anti-B19 antibodies because of either the immunocompromised nature of the host or the use of immunosuppressive drugs. There was a higher prevalence of hypocomplementemia in patients with parvovirus B19 viremia than in those without parvovirus. Keywords: Human parvovirus B19, Systemic lupus erythematosus, Nested PCREgypt J Pediatr Allergy Immunol 2011;9(2):71-7
«Learning and Confirming» in Pharmaforschung und -entwicklung. Von Sackgassen und Durchbrüchen
Louis Shreiner prägte den Begriff «Learn and Confirm», um die Trennung von Früh- und Spätphase der Medikamentenentwicklung zu bezeichnen. Frühe oder «Lern»-Phasen dienen der Charakterisierung des Medikaments. Die Beschreibung der Dosis-Wirkung, das Testen von Biomarkern und die Patientenauswahl sind die Ziele der frühen Phasen. Die späten Phasen, für Wirksamkeit und Sicherheit, sind zur Bestätigung, weil sie teuer und langwierig sind. Tritt das Lernen von Arzneimitteleigenschaften noch in einer späten Phase auf, besteht ein hohes Risiko des Scheiterns. Typischerweise gibt es Budget- und Zeitdruck, um die klinische Entwicklung zu beschleunigen, indem Phasen kombiniert oder überlagert werden und Fragen auf diejenigen beschränkt werden, die für den Phasenübergang erforderlich sind. Etwa neun von zehn Medikamentenkandidaten erhalten keine Zulassung, was enorme Auswirkungen auf die Gesamtkosten der Medikamentenentwicklung hat. Doch was treibt diese Misserfolge an und wie kann die Forschung die Produktivität bei der Verlagerung von Medikamentenkandidaten aus dem Labor in die Klinik verbessern? Und besonders: Wie lernen wir aus Fehlern
Acute oral toxicity of two products from a microbial pest control agent (Beauveria bassiana) on physiological status aspects of male albino rats
Background: Synthetic pesticides have accumulated in environment causing harm to humans and ecosystems. As a result, the use of biopesticides in agriculture and public health has expanded as a substitute for traditional pesticides. Purpose: To investigate the acute oral toxicity of Beauveria bassiana, on physiological status aspects of male rats. Material and Methods: Metabolic crude (MC), and wettable powder formulation (2.5% WP) from the local isolate of B. bassiana (AUMC 9896) were tested on adult Sprague Dawley (SD) male rats by single oral dose. Results: There was no evidence of death or toxic symptoms in any of the treated groups. In contrast, each product caused a significant increase in the body weight gain and relative liver weights of B. bassiana-exposed male and reduced the brain somatic index with WP only as compared to the control. The studied bioinsecticide also caused a substantial rise in total erythrocyte and absolute differential leucocyte counts, while red blood cell distribution width (RDW) and platelet count (Plt) were decreased significantly. Furthermore, male rats exposed to both types of B. bassiana, aspartate aminotransferases (AST), total protein (TP), albumin (Alb), AST/ALT, triglyceride, and very low-density lipoprotein cholesterol (VLDL) were elevated compared to the untreated group, whereas alkaline phosphatase (ALP) activity, globulin (Glb), Alb/Glb, urea content, and low-density lipoprotein cholesterol (LDL) count fluctuated between increased and decreased. Also, B. bassiana-treated rats had lower serum cholesterol and high-density lipoprotein cholesterol levels (HDL) values.Conclusion: These results suggest that both treatments have slight effects on complete blood count (CBC) of treated male rats and marked effect on liver function, lipid profile, body weight gain and somatic index of the liver and brain
Metabolismo lipídico en ratas alimentadas con mantequilla o productos derivados de la mantequilla como fuente grasa
Albino rats were administered four different fat sources; corn oil, butter, samn and morta combined with corn oil. The butter rat group exhibited the highest rates of serum cholesterol, total lipids and triglycerides but the lowest one of phospholipid. The heart, liver and spleen organs of this group showed a similar trend. Both liver and renal functions of this group were impaired. Both samn and morta rat groups were close to the control in the distribution of lipid fractions either in serum or organs and showed slight effects on liver and renal functions.Cuatro fuentes de grasas diferentes se administraron a ratas albino: aceite de maíz, mantequilla, "samn" y "morta" combinados con aceite de maíz. El grupo de ratas al que se le suministró mantequilla exhibió los índices más altos de colesterol, lípidos totales y triglicéridos en suero pero los más bajos de fosfolípidos, mostrando una tendencia similar los órganos corazón, hígado y bazo. Por otra parte, tanto las funciones hepáticas como renales de este grupo fueron dañadas. Los grupos de ratas a los que se les administró "samn" y "morta" se acercaron al control en la distribución de las fracciones lipídicas, tanto en suero como en órganos y mostraron débiles efectos sobre las funciones hepáticas y renales
Evaluation of different biochemical markers in prediction of metabolic syndrome in polycystic ovary syndrome patients
Background: Polycystic ovary syndrome (PCOS) is the commonest cause of chronic hyperandrogenic anovulation. Insulin resistance and compensatory hyperinsulinemia are keys of the pathogenesis of PCOS. It is also considered as a metabolic disorder. Since the components of metabolic syndrome (MBS) namely obesity, glucose intolerance, dyslipidemia, and hypertension are the common features of this syndrome. The association between MBS and PCOS can be explained by different theories as insulin resistance, obesity, and related adipose tissue factors (adipocytokines) independent of insulin resistance are the main pathogenic contributors to both disorders.Methods: A total of 143 women with PCOS were recruited as study subjects. All participants were subjected to anthropometric measurements, clinical assessment, and biochemical tests [fasting glucose, fasting insulin, and homeostatic model assessment-insulin resistance (HOMA-IR)]. Hormonal profile particularly leptin and homocysteine levels were also evaluated.Results: 25 patients (17.4%) out of 143 women with PCOS met the criteria for MBS. Patients with MBS had significantly higher body mass index, blood pressure, HOMA-IR, leptin, and homocysteine levels compared to PCOS only patients. When HOMA-IR cut off was ≥4.3 sensitivity and specificity were 90%, 88.6%, but when leptin level was ≥34.5 the corresponding statistics were 79.6%, 75.5%.Conclusions: Serum leptin, homocysteine, HOMA-IR as well as other biochemical markers are significantly higher in women with PCOS and MBS compared to PCOS only women. PCOS is associated with various factors like insulin resistance, obesity, and dyslipidemia. Consequently, adipocytokines and HOMA-IR play important role in the prediction of MBS in patients with PCOS
Evaluation of selective peripheral neurotomies in the treatment of refractory lower limb spasticity in adults
Background: ‘‘Selective peripheral neurotomies” (SPNs) are indicated for the treatment of refractory focal and multifocal spasticity of lower limbs in adults.Objective: To evaluate the surgical results of selective peripheral neurotomies in 20 adult patients who had refractory focal & multifocal spasticity of the lower limbs, follow up period of one year.Patients and Methods: Prospective study included 20 adult patients who had refractory spasticity of the lower limbs. Preoperative evaluation for muscle tone using Modified Ashworth Score (MAS), muscle power using Medical Research Council Scale (MRCS), functional assessment using Oswestry Functional Scale (OFS) and Range Of Motion (ROM) using manual goniometry were done for all patients. All cases underwent surgery in the form of SPN of tibial, obturator, sciatic and/or femoral nerves. Follow up of the patients was done at 10th day, 3, 6 months and one year postoperatively.Results: The mean age of patients was 31.35 ± 12.42 years. There were statistically significant improvement of muscle tone, muscle power, functional assessment and range of motion between preoperative and one year postoperative values. Improvement of the muscle tone was from a preoperative Mean ± SD of 3.60 ± 0.68 on MAS to a postoperative 2.30 ± 0.86 at one year, improvement of muscle power on MRCS was from preoperative Mean ± SD 3.75 ± 1.08 to postoperative 4.08 ± 0.69 at one year, There was a functional improvement from a preoperative Mean ± SD of 3.0 ± 0.73 on OFS to 3.60 ± 0.60 at one year postoperatively. Also, there was a significant improvement between preoperative ROM Mean ± SD 61.25 ± 15.29 and one year postoperatively 72.25 ± 12.19.Conclusions: Selective peripheral neurotomies could effectively improve muscle tone, muscle power, functional performance & range of motion in patients with refractory focal and multifocal spasticity in the lower limbs.Keywords: Selective peripheral neurotomies, Spasticity, Neuroablative surgeries, Functional neurosurger
A Cyber-Physical Architecture for Microgrids based on Deep learning and LORA Technology
This paper proposes a cyber-physical architecture for the secured social
operation of isolated hybrid microgrids (HMGs). On the physical side of the
proposed architecture, an optimal scheduling scheme considering various
renewable energy sources (RESs) and fossil fuel-based distributed generation
units (DGs) is proposed. Regarding the cyber layer of MGs, a wireless
architecture based on low range wide area (LORA) technology is introduced for
advanced metering infrastructure (AMI) in smart electricity grids. In the
proposed architecture, the LORA data frame is described in detail and designed
for the application of smart meters considering DGs and ac-dc converters.
Additionally, since the cyber layer of smart grids is highly vulnerable to
cyber-attacks, t1his paper proposes a deep-learning-based cyber-attack
detection model (CADM) based on bidirectional long short-term memory (BLSTM)
and sequential hypothesis testing (SHT) to detect false data injection attacks
(FDIA) on the smart meters within AMI. The performance of the proposed energy
management architecture is evaluated using the IEEE 33-bus test system. In
order to investigate the effect of FDIA on the isolated HMGs and highlight the
interactions between the cyber layer and physical layer, an FDIA is launched
against the test system. The results showed that a successful attack can highly
damage the system and cause widespread load shedding. Also, the performance of
the proposed CADM is examined using a real-world dataset. Results prove the
effectiveness of the proposed CADM in detecting the attacks using only two
samples
- …