A method for forensic artifact collection, analysis and incident response in environments running Session Initiation Protocol (SIP) and Session Description protocol

In this paper, we perform an analysis of SIP, a popular voice over IP (VoIP) protocol and propose a framework for capturing and analysing volatile VoIP data in order to determine forensic readiness requirements for effectively identifying an attacker. The analysis was performed on real attack data and the findings were encouraging. It seems that if appropriate forensic readiness processes and controls are in place, a wealth of evidence can be obtained. The type of the end user equipment of the internal users, the private IP, the software that is used can help build a reliable baseline information database. On the other hand the private IP addresses of the potential attacker even during the presence of NAT services, as well as and the attack tools employed by the malicious parties are logged for further analysis

Effect of polydispersity and bubble clustering on the steady shear viscosity of dilute bubble suspensions in Newtonian media

This work examines the steady shear viscosity of dilute polydisperse bubble suspensions generated in a mixture of mineral oil and span 80. We proved theoretically that, in polydisperse bubble suspensions, the shear-thinning behavior spans a capillary number (Ca) range between 0.01 and 100, instead of occurring at Ca~1, which is the case for monodisperse suspensions. However, for the effect of polydispersity to become apparent, the bubble size distribution should be bimodal, with very small and very large bubbles having similar volume fractions. In any other case, we can consider the polydisperse suspension as monodisperse, with a volume-weighted average diameter (d43). To confirm the theoretical results, we carried out steady shear rheological tests. Our measurements revealed an unexpected double power-law decay of the relative viscosity. To investigate this behavior further, we visualized the produced bubble suspensions under shear. The visualization experiments revealed that bubbles started forming clusters and threads at average capillary number around 0.01, where we observed the first decay of viscosity. CFD simulations confirmed that under the presence of bubble clusters and threads the fluid streamlines distort less, thus resulting in a decrease of the suspension viscosity. Consequently, we can attribute the first decay of the relative viscosity to the formation of bubble clusters and threads, proving that the novel shear-thinning behavior we observed is due to a combination of bubble clustering and deformation

Privacy-preserving, User-centric VoIP CAPTCHA Challenges: an Integrated Solution in the SIP Environment

Purpose – This work aims to argue that it is possible to address discrimination issues that naturally arise in contemporary audio CAPTCHA challenges and potentially enhance the effectiveness of audio CAPTCHA systems by adapting the challenges to the user characteristics. Design/methodology/approach – A prototype has been designed, called PrivCAPTCHA, to offer privacy-preserving, user-centric CAPTCHA challenges. Anonymous credential proofs are integrated into the Session Initiation Protocol (SIP) protocol and the approach is evaluated in a real-world Voice over Internet Protocol (VoIP) environment. Findings – The results of this work indicate that it is possible to create VoIP CAPTCHA services offering privacy-preserving, user-centric challenges while maintaining sufficient efficiency. Research limitations/implications – The proposed approach was evaluated through an experimental implementation to demonstrate its feasibility. Additional features, such as appropriate user interfaces and efficiency optimisations, would be useful for a commercial product. Security measures to protect the system from attacks against the SIP protocol would be useful to counteract the effects of the introduced overhead. Future research could investigate the use of this approach on non-audio CAPTCHA services. Practical implications – PrivCAPTCHA is expected to achieve fairer, non-discriminating CAPTCHA services while protecting the user’s privacy. Adoption success relies upon the general need for employment of privacy-preserving practices in electronic interactions. Social implications – This approach is expected to enhance the quality of life of users, who will now receive CAPTCHA challenges closer to their characteristics. This applies especially to users with disabilities. Additionally, as a privacy-preserving service, this approach is expected to increase trust during the use of services that use it. Originality/value – To the best of authors’ knowledge, this is the first comprehensive proposal for privacy-preserving CAPTCHA challenge adaptation. The proposed system aims at providing an improved CAPTCHA service that is more appropriate for and trusted by human users

Transplantation of pediatric renal allografts from donors less than 10 kg

Few transplant programs use kidneys from donors with body weight (BW) BW \u3c 10 kg would provide similar transplant outcomes to larger grafts. All pediatric en bloc renal transplants performed at our center between 2001 and 2017 were reviewed (N = 28). Data were stratified by smaller (donor BW \u3c 10 kg; n = 11) or larger donors (BW \u3e 10 kg; n = 17). Renal volume was assessed during follow-up with ultrasound. Demographic characteristics were similar between the 2 groups of recipients. After mean follow-up of 44 months (smaller donors) and 124 months (larger donors), graft and patient outcomes were similar between groups. Serum creatinine at 1, 3, and 5 years was no different between groups. At 1 day posttransplant, mean total renal volume in the smaller donors was 28 +/- 9 mm(3) vs 45 +/- 12 mm(3) (P \u3c .01). By 3 weeks, it was 53 +/- 19 mm(3) (smaller donors) versus 73 +/- 19 mm(3) (larger donors) (P = NS). Complication rates were similar between both groups with 1 case of venous thrombosis in the smaller group. With experience, outcomes are equivalent to those from larger pediatric donors

Intra-Renal Hemodynamic Changes After Habitual Physical Activity in Patients with Chronic Kidney Disease

Background: Chronic Kidney Disease (CKD) is considered a silent epidemic with a continuously growing prevalence around the world. Due to uremia many functional and morphological abnormalities occur in almost all systems. Mostly affected, the cardiovascular system, leads to diminished cardiac function that affects patients’ functional capacity and physical activity levels, reducing survival and increasing all-cause mortality. Systematic exercise training ameliorates uremia induced body deficits and significantly improves the survival of CKD patients. Intradialytic exercise training has been recommended as a complementary therapeutic modality equally important to hemodialysis. Methods: The aim of this systematic review is to provide an update on recent advances in our understanding of how exercise training improves functionality of the cardiovascular system through the hemodynamic changes induced by habitual or intradialytic and/or home-based exercise training programs. Results: Systematic exercise training induces beneficial adaptive responses and influences many sensitive physiological biomarkers, such as oxidative stress biomarkers that are implicated in the development of atherosclerosis. Additionally, exercise training decreases the cardiovascular risk by improving the autonomic nervous system activity and the left ventricular function and by reducing nontraditional risk factors such as epicardial adipose tissue. It seems that all these central and peripheral adaptations to exercise training significantly contribute to improvements in functional capacity and exercise tolerance among CKD patients and result in the risk reduction of CKD-associated disorders. Conclusion: Exercise training could serve as a complimentary therapeutic strategy in CKD patients while health care providers should motivate patients to engage in any type of exercise training programs

On X-ray Optical Depth in the Coronae of Active Stars

We have investigated the optical thickness of the coronal plasma through the analysis of high-resolution X-ray spectra of a large sample of active stars observed with the High Energy Transmission Grating Spectrometer on Chandra. In particular, we probed for the presence of significant resonant scattering in the strong Lyman series lines arising from hydrogen-like oxygen and neon ions. The active RS CVn-type binaries II Peg and IM Peg and the single M dwarf EV Lac show significant optical depth. For these active coronae, the Lya/Lyb ratios are significantly depleted as compared with theoretical predictions and with the same ratios observed in similar active stars. Interpreting these decrements in terms of resonance scattering of line photons out of the line-of-sight, we are able to derive an estimate for the typical size of coronal structures, and from these we also derive estimates of coronal filling factors. For all three sources we find that the both the photon path length as a fraction of the stellar radius, and the implied surface filling factors are very small and amount to a few percent at most. The measured Lya/Lyb ratios are in good agreement with APED theoretical predictions, thus indicating negligible optical depth, for the other sources in our sample. We discuss the implications for coronal structuring and heating flux requirements. For the stellar sample as a whole, the data suggest increasing quenching of Lya relative to Lyb as function of both L_x/L_bol and the density-sensitive MgXI forbidden to intercombination line ratio, as might generally be expected.Comment: Accepted for publication on the Astrophysical Journa

Systemic Redox Imbalance in Chronic Kidney Disease: A Systematic Review.

Patients with chronic kidney disease (CKD) experience imbalance between oxygen reactive species (ROS) production and antioxidant defenses leading to cell and tissue damage. However, it remains unclear at which stage of renal insufficiency the redox imbalance becomes more profound. The aim of this systematic review was to provide an update on recent advances in our understanding of how the redox status changes in the progression of renal disease from predialysis stages 1 to 4 to end stage 5 and whether the various treatments and dialysis modalities influence the redox balance. A systematic review was conducted searching PubMed and Scopus by using the Cochrane and PRISMA guidelines. In total, thirty-nine studies met the inclusion criteria and were reviewed. Even from an early stage, imbalance in redox status is evident and as the kidney function worsens it becomes more profound. Hemodialysis therapy per se seems to negatively influence the redox status by the elevation of lipid peroxidation markers, protein carbonylation, and impairing erythrocyte antioxidant defense. However, other dialysis modalities do not so far appear to confer advantages. Supplementation with antioxidants might assist and should be considered as an early intervention to halt premature atherogenesis development at an early stage of CKD

The Structure of Stellar Coronae in Active Binary Systems

A survey of 28 stars using EUV spectra has been conducted to establish the structure of stellar coronae in active binary systems from the EMD, electron densities, and scale sizes. Observations obtained by the EUVE during 9 years of operation are included for the stars in the sample. EUVE data allow a continuous EMD to be constructed in the range log T~5.6-7.4, using iron emission lines. These data are complemented with IUE observations to model the lower temperature range. Inspection of the EMD shows an outstanding narrow enhancement, or ``bump'' peaking around log T~6.9 in 25 of the stars, defining a fundamental coronal structure. The emission measure per unit stellar area decreases with increasing orbital (or photometric) periods of the target stars; stars in binaries generally have more material at coronal temperatures than slowly rotating single stars. High electron densities (Ne>10^12 cm^-3) are derived at ~10 MK for some targets, implying small emitting volumes. The observations suggest the magnetic stellar coronae of these stars are consistent with two basic classes of magnetic loops: solar-like loops with maximum temperature around log T~6.3 and lower electron densities (Ne>10^9-10.5), and hotter loops peaking around log T~6.9 with higher electron densities (Ne>10^12). For the most active stars, material exists at much higher temperatures (log T>6.9) as well. However, current ab initio stellar loop models cannot reproduce such a configuration. Analysis of the light curves of these systems reveals signatures of rotation of coronal material, as well as apparent seasonal changes in the activity levels.Comment: 45 pages, 9 figures (with 20 eps files). Accepted for its publication in ApJ

Hyperthyroidism from autoimmune thyroiditis in a man with type 1 diabetes mellitus: a case report

<p>Abstract</p> <p>Introduction</p> <p>The presentation, diagnosis, clinical course and treatment of a man with hyperthyroidism secondary to autoimmune thyroiditis in the setting of type 1 diabetes mellitus has not previously been described.</p> <p>Case presentation</p> <p>A 32-year-old European-American man with an eight-year history of type 1 diabetes mellitus presented with an unintentional 22-pound weight loss but an otherwise normal physical examination. Laboratory studies revealed a suppressed thyroid-stimulating hormone concentration and an elevated thyroxine level, which are consistent with hyperthyroidism. His anti-thyroid peroxidase antibodies were positive, and his thyroid-stimulating immunoglobulin test was negative. Uptake of radioactive iodine by scanning was 0.5% at 24 hours. The patient was diagnosed with autoimmune thyroiditis. Six weeks following his initial presentation he became clinically and biochemically hypothyroid and was treated with thyroxine.</p> <p>Conclusion</p> <p>This report demonstrates that autoimmune thyroiditis presenting as hyperthyroidism can occur in a man with type 1 diabetes mellitus. Autoimmune thyroiditis may be an isolated manifestation of autoimmunity or may be part of an autoimmune polyglandular syndrome. Among patients with type 1 diabetes mellitus who present with hyperthyroidism, Graves' disease and other forms of hyperthyroidism need to be excluded as autoimmune thyroiditis can progress quickly to hypothyroidism, requiring thyroid hormone replacement therapy.</p