The Melbourne Shuffle: Improving Oblivious Storage in the Cloud

We present a simple, efficient, and secure data-oblivious randomized shuffle algorithm. This is the first secure data-oblivious shuffle that is not based on sorting. Our method can be used to improve previous oblivious storage solutions for network-based outsourcing of data

Diabetic patients served at a regional level hospital: What is their clinical picture?

Objectives: We describe the demographics, diabetic characteristics,  diabetic control and complications in the diabetes service in Edendale Regional Hospital, Pietermaritzburg, in this study. Diabetes mellitus, together with its complications, is increasing at an alarming rate worldwide. Good glycaemic control translates into lower long-term complications andlonger life expectancy. Previous studies performed in both the public and the private sectors have demonstrated that there is suboptimal diabetic control in South Africa.Design: This was a retrospective database analysis. Datasheets were designed to ensure a comprehensive and standardised assessment of patients attending Edendale Hospitalfs diabetic clinic. Data were stored in a designed-forpurpose database.Subjects and setting: Data from 653 first-visit diabetic patients visiting Edendale Hospitalfs diabetic clinic between 1 October 2012 and 30 September 2013 were collected.Outcome measures: Glycaemic control, diabetic complications and target blood pressure were the outcome measures studied.Results: A total of 653 first-visit patients were seen, of whom 77.03% were female and 83.40% were type 2 diabetes patients. Only 36.33% of the type 2, and 49.07% of the type 1, diabetes mellitus patients, achieved a target blood pressure of . 140/80 mmHg. Only 1.23% of the type 1, and 11.18% of the type 2, diabetes mellitus patients, achieved optimal  glycaemic control, defined as haemoglobin (Hb)A1c . 7%. The mean HbA1c in the patients with type 1 diabetes mellitus was 11.82%, and 10.52% in the type 2 diabetes mellitus patients.Conclusion: This study showed the suboptimal control of both diabetes mellitus and hypertension in the clinic, together with high rates of diabetes complications. Obesity remains a major modifiable risk factor in both type 1 and 2 diabetes patients. Blood glucose control in this resource-limited setting was similar in those patients with home blood glucose monitoring versus those without it

A deadly combination – HIV and diabetes mellitus: Where are we now?

Background. The combination of HIV infection and diabetes mellitus (DM) represents a collision of two chronic conditions. Both HIV and DM increase the risk of developing tuberculosis (TB). Health resources in developing countries are already under strain as a result of the TB epidemic and poor diabetic control would further worsen this epidemic. Optimal diabetic control provides one avenue of curbing the TB epidemic in developing countries.Objectives. To establish if there is a difference in blood pressure, lipid and glycaemic control and complications between HIV-infected and uninfected diabetic patients; and to compare characteristics among HIV-infected diabetic patients between those with optimal and suboptimal glycaemic control.Methods. This was a retrospective chart review of all patients who visited the Edendale Hospital diabetic clinic, Pietermaritzburg, from 1 October 2012 to 30 September 2013.Results. There were statistically significant differences noted in the following parameters between HIV-infected and uninfected diabetic patients: (i) mean HbA1c% (11.08% v. 10.14%, respectively); (ii) nephropathy defined by proteinuria (25.66% v. 15.43%); (iii) neuropathy (48.68% v. 42.10%); and (iv) Kidney Disease Outcomes Quality Initiative (KDOQI) stage ≥2 chronic kidney disease (30.87% v. 41.67%). There were no significant differences noted in the percentage of patients achieving the following target parameters between the two cohorts: (i) blood pressure (42.11% v. 35.62%); (ii) total cholesterol (36.84% v. 34.67%); and (iii) triglycerides (42.76% v. 40.19%). Within the HIV-infected diabetic cohort 85.23% displayed suboptimal glycaemic control. A significant percentage of HIV-infected diabetic patients on antiretroviral (ARV) therapy (89.36%) had suboptimal glycaemic control. HIV-infected female diabetic patients showed a significant increased waist circumference when compared with their HIV-uninfected counterparts.Conclusion. HIV-infected diabetic patients had significantly poorer blood sugar control and a higher incidence of neuropathy and nephropathy (when defined by overt proteinuria). There was a non-significant difference noted between the HIV-infected and uninfected diabetic patients with regard to blood pressure and lipid control. The majority of HIV-infected patients on ARVs failed to achieve target glycaemic control. Obesity remains a global challenge, as noted in both the HIV-infected and uninfected diabetic patients

Improvement noted after a multifaceted approach to diabetes mellitus management

Background: Optimal control of diabetes mellitus remains elusive, especially in developing countries. A comprehensive and standardised approach, coupled with intensive patient and clinician education, may provide the solution.Methods: Comprehensive datasheets accompanied by patient education from a multidisciplinary team and clinician retraining on diabetes management was introduced into the Edendale Hospital diabetes clinic in 2012. This study compares diabetes control starting October 1, 2012 to September 30, 2013 (Y1) to October 1, 2013 to September 30, 2014 (Y2).Results: Significant changes (p-values < 0.005) were noted in the following parameters between Y2 and Y1 respectively:* Mean HbA1c% (10.41 ± 2.91 vs. 11.26 ± 2.99).* Mean HbA1c in males (9.46 vs. 10.57) and (10.38 vs. 11.19) for females.* Mean HbA1c for type 1 (11.80 vs.10.77) and type 2 patients (10.91 vs.10.10).* Percentage of patients achieving triglyceride control (64.28 vs. 52.85).* Percentage of patients making lifestyle changes and performing home glucose monitoring.* Increase in female waist circumference (97.29 vs. 85.95 cm).* Increase in BMI in males (29.65 vs. 27.92 kg/m2).Conclusion: This multifaceted approach to diabetes care in a resource-limited clinic significantly improved glycaemic and triglyceride control. Obesity remains a major challenge. This model could serve as a blueprint for other such resource-limited clinics

The burden of diabetes mellitus in KwaZulu-Natal’s public sector: A 5-year perspective

Background. Diabetes mellitus (DM), together with its devastating complications, has a huge impact on both the patients it affects and the global economy as a whole. The economies of developing countries are already under threat from communicable diseases. More needs to be done to stem the tide of non-communicable diseases like DM. In order for us to develop new strategies to tackle this dread disease we need to obtain and analyse as many data as possible from the geographical area where we work.Objective. To describe the burden of DM in the public sector of the province of KwaZulu-Natal (KZN), South Africa (SA).Method. Data on the number of diabetes visits, DM patients that were initiated on treatment, defaulters and DM-related amputations were accessed from the Department of Health records for the period 2010 - 2014 inclusive.Results. There was a decline in the number of patients initiated on treatment per 100 000 population from 2010 to 2014 inclusive (265.9 v. 197.5 v. 200.7 v. 133.4 v. 148.7). Defaulter rates for 2013 compared with 2014 were 3.31% v. 1.75%, respectively and amputation rates were 0.09% v. 0.05% for 2013 and 2014, respectively. There was a strong proportional relationship observed between the number of defaulters and number of diabetes-related amputations (r=0.801; p=0.000) (Pearson correlation). A notable percentage of DM patients ranging between 63% and 80% were commenced on pharmacological therapy at their local clinics rather than at hospitals in the province.Conclusion. Strategies directed towards detection and treatment of DM, together with decreasing defaulter rates and thereby decreasing diabetes-related amputations, need to be addressed urgently. The majority of patients were initiated on therapy at the clinic level. This emphasises the need to strengthen our clinics in terms of resources, staffing, and nursing and clinician education, as this is where diabetes control begins. Although this study was based solely in KZN, the second most populous province in SA, it probably reflects the current situation regarding DM in other provinces of SA as well

Exact calculations of first-passage quantities on recursive networks

We present general methods to exactly calculate mean-first passage quantities on self-similar networks defined recursively. In particular, we calculate the mean first-passage time and the splitting probabilities associated to a source and one or several targets; averaged quantities over a given set of sources (e.g., same-connectivity nodes) are also derived. The exact estimate of such quantities highlights the dependency of first-passage processes with respect to the source-target distance, which has recently revealed to be a key parameter to characterize transport in complex media. We explicitly perform calculations for different classes of recursive networks (finitely ramified fractals, scale-free (trans)fractals, non-fractals, mixtures between fractals and non-fractals, non-decimable hierarchical graphs) of arbitrary size. Our approach unifies and significantly extends the available results in the field.Comment: 16 pages, 10 figure

Cutoff for the East process

The East process is a 1D kinetically constrained interacting particle system, introduced in the physics literature in the early 90's to model liquid-glass transitions. Spectral gap estimates of Aldous and Diaconis in 2002 imply that its mixing time on $L$ sites has order $L$. We complement that result and show cutoff with an $O(\sqrt{L})$-window. The main ingredient is an analysis of the front of the process (its rightmost zero in the setup where zeros facilitate updates to their right). One expects the front to advance as a biased random walk, whose normal fluctuations would imply cutoff with an $O(\sqrt{L})$-window. The law of the process behind the front plays a crucial role: Blondel showed that it converges to an invariant measure $\nu$, on which very little is known. Here we obtain quantitative bounds on the speed of convergence to $\nu$, finding that it is exponentially fast. We then derive that the increments of the front behave as a stationary mixing sequence of random variables, and a Stein-method based argument of Bolthausen ('82) implies a CLT for the location of the front, yielding the cutoff result. Finally, we supplement these results by a study of analogous kinetically constrained models on trees, again establishing cutoff, yet this time with an $O(1)$-window.Comment: 33 pages, 2 figure

Particle Systems with Stochastic Passing

We study a system of particles moving on a line in the same direction. Passing is allowed and when a fast particle overtakes a slow particle, it acquires a new velocity drawn from a distribution P_0(v), while the slow particle remains unaffected. We show that the system reaches a steady state if P_0(v) vanishes at its lower cutoff; otherwise, the system evolves indefinitely.Comment: 5 pages, 5 figure

Autophagy gene expression profiling identifies a defective microtubule-associated protein light chain 3A mutant in cancer.

The cellular stress response autophagy has been implicated in various diseases including neuro-degeneration and cancer. The role of autophagy in cancer is not clearly understood and both tumour promoting and tumour suppressive effects of autophagy have been reported, which complicates the design of therapeutic strategies based on targeting the autophagy pathway. Here, we have systematically analyzed gene expression data for 47 autophagy genes for deletions, amplifications and mutations in various cancers. We found that several cancer types have frequent autophagy gene amplifications, whereas deletions are more frequent in prostate adenocarcinomas. Other cancer types such as glioblastoma and thyroid carcinoma show very few alterations in any of the 47 autophagy genes. Overall, individual autophagy core genes are altered at low frequency in cancer, suggesting that cancer cells require functional autophagy. Some autophagy genes show frequent single base mutations, such as members of the ULK family of protein kinases. Furthermore, we found hotspot mutations in the arginine-rich stretch in MAP1LC3A resulting in reduced cleavage of MAP1LC3A by ATG4B both in vitro and in vivo, suggesting a functional implication of this gene mutation in cancer development

Empires and Percolation: Stochastic Merging of Adjacent Regions

We introduce a stochastic model in which adjacent planar regions $A, B$ merge stochastically at some rate $\lambda(A,B)$, and observe analogies with the well-studied topics of mean-field coagulation and of bond percolation. Do infinite regions appear in finite time? We give a simple condition on $\lambda$ for this {\em hegemony} property to hold, and another simple condition for it to not hold, but there is a large gap between these conditions, which includes the case $\lambda(A,B) \equiv 1$. For this case, a non-rigorous analytic argument and simulations suggest hegemony.Comment: 13 page