TrustShadow: Secure Execution of Unmodified Applications with ARM TrustZone

The rapid evolution of Internet-of-Things (IoT) technologies has led to an emerging need to make it smarter. A variety of applications now run simultaneously on an ARM-based processor. For example, devices on the edge of the Internet are provided with higher horsepower to be entrusted with storing, processing and analyzing data collected from IoT devices. This significantly improves efficiency and reduces the amount of data that needs to be transported to the cloud for data processing, analysis and storage. However, commodity OSes are prone to compromise. Once they are exploited, attackers can access the data on these devices. Since the data stored and processed on the devices can be sensitive, left untackled, this is particularly disconcerting. In this paper, we propose a new system, TrustShadow that shields legacy applications from untrusted OSes. TrustShadow takes advantage of ARM TrustZone technology and partitions resources into the secure and normal worlds. In the secure world, TrustShadow constructs a trusted execution environment for security-critical applications. This trusted environment is maintained by a lightweight runtime system that coordinates the communication between applications and the ordinary OS running in the normal world. The runtime system does not provide system services itself. Rather, it forwards requests for system services to the ordinary OS, and verifies the correctness of the responses. To demonstrate the efficiency of this design, we prototyped TrustShadow on a real chip board with ARM TrustZone support, and evaluated its performance using both microbenchmarks and real-world applications. We showed TrustShadow introduces only negligible overhead to real-world applications.Comment: MobiSys 201

Polarization of superfluid turbulence

We show that normal fluid eddies in turbulent helium II polarize the tangle of quantized vortex lines present in the flow, thus inducing superfluid vorticity patterns similar to the driving normal fluid eddies. We also show that the polarization is effective over the entire inertial range. The results help explain the surprising analogies between classical and superfluid turbulence which have been observed recently.Comment: 3 figure

Tracking official development assistance for reproductive health in conflict-affected countries: 2002-2011.

OBJECTIVE: To provide information on trends on official development assistance (ODA) disbursement patterns for reproductive health activities in 18 conflict-affected countries. DESIGN: Secondary data analysis. SAMPLE: 18 conflict-affected countries and 36 non-conflict-affected countries. METHODS: The Creditor Reporting System (CRS) database was analyzed for ODA disbursement for direct and indirect reproductive health activities to 18 conflict-affected countries (2002-2011). A comparative analysis was also made with 36 non-conflict-affected counties in the same 'least-developed' income category. Multivariate regression analyses examined associations between conflict status and reproductive health ODA and between reproductive needs and ODA disbursements. MAIN OUTCOME MEASURES: Patterns of ODA disbursements (constant U.S. dollars) for reproductive health activities. RESULTS: The average annual ODA disbursed for reproductive health to 18 conflict-affected countries from 2002 to 2011 was US$ 1.93 per person per year. There was an increase of 298% in ODA for reproductive health activities to the conflict-affected countries between 2002 and 2011; 56% of this increase was due to increases in HIV/AIDS funding. The average annual per capita reproductive health ODA disbursed to least-developed non-conflict-affected countries was 57% higher than to least-developed conflict-affected countries. Regression analyses confirmed disparities in ODA to and between conflict-affected countries. CONCLUSIONS: Despite increases in ODA for reproductive health for conflict-affected countries (albeit largely for HIV/AIDS activities), considerable disparities remains. TWEETABLE ABSTRACT: Study tracking 10 years of aid for reproductive aid shows major disparities for conflict-affected countries

Negotiating the transition from adolescence to motherhood: Coping with prenatal and parenting stress in teenage mothers in Mulago hospital, Uganda

<p>Abstract</p> <p>Background</p> <p>Adolescence is a transitional stage from childhood to adulthood that is characterized by physical, physiological, psychosocial and behavioral changes that are influenced to a large extent by the age, culture and socialization of the individual. To explore what adolescent mothers perceive as their struggles during the period of transition from childhood to parenthood (through motherhood) and to describe strategies employed in coping with stress of pregnancy, motherhood and parenthood.</p> <p>Methods</p> <p>Longitudinal qualitative study involving twenty two in-depth interviews and six focus group discussions among pregnant adolescents who were followed from pregnant to delivery, from January 2004 to August 2005. Participant were selected by theoretical sampling and data was analyzed using grounded theory.</p> <p>Results</p> <p>Overall, young adolescents reported more anxiety, loss of self esteem (when they conceived), difficulty in accessing financial, moral and material support from parents or partners and stigmatization by health workers when they sought care from health facilities. Three strategies by which adolescent mothers cope with parenting and pregnancy stress that were described as utilizing opportunities (thriving), accommodating the challenges (bargaining and surviving), or failure (despairing), and varied in the extent to which they enabled adolescents to cope with the stress.</p> <p>Conclusion</p> <p>Adolescents on the transition to motherhood have variable needs and aspirations and utilize different strategies to cope with the stress of pregnancy and parenthood.</p

Glacier Calving Rates Due to Subglacial Discharge, Fjord Circulation, and Free Convection

Tidewater glacier calving provides the most direct mechanism of ice transfer from land to the ocean. However, the physical melt processes influencing calving remain challenging to constrain. In this study we focus on calving rates at Kongsbreen, a tidewater glacier in Svalbard, due to three mechanisms of submarine melt: (1) free convection, (2) horizontal fjord circulation, and (3) meltwater discharge. To calculate an overall calving rate, we measure glacier velocity and terminus change using Sentinel imagery. We calculate free convection, fjord circulation, and meltwater discharge calving using mooring data for mid-fjord ocean temperature (30–80 m depth), reanalysis results for meltwater runoff, and georectified time-lapse imagery to track icebergs and infer surface circulation. Results show that the total glacier calving rate is highly correlated with ocean temperature during the 2016 melt season. When runoff was present, we found that subglacial discharge accounted for calving rates an order of magnitude greater than the maximum calving rates assigned to the other two melting mechanisms combined. Further, subglacial discharge at Kongsbreen was more efficient in inducing calving later in the season than earlier in the season, implying that the increase in ocean temperatures, the timing of meltwater discharge within a melt season, and/or the development of discrete meltwater exit channels are critical components to calving rates. As the recent atmospheric warming trend and subsequent increase in meltwater discharge is expected to continue, it is essential to understand the processes contributing to an increase in glacier calving and incorporate these processes into predictive models

Long-Term Transplantation Outcomes in Patients With Primary Hyperoxaluria Type 1 Included in the European Hyperoxaluria Consortium (OxalEurope) Registry

INTRODUCTION: In primary hyperoxaluria type 1 (PH1), oxalate overproduction frequently causes kidney stones, nephrocalcinosis, and kidney failure. As PH1 is caused by a congenital liver enzyme defect, combined liver–kidney transplantation (CLKT) has been recommended in patients with kidney failure. Nevertheless, systematic analyses on long-term transplantation outcomes are scarce. The merits of a sequential over combined procedure regarding kidney graft survival remain unclear as is the place of isolated kidney transplantation (KT) for patients with vitamin B6-responsive genotypes. METHODS: We used the OxalEurope registry for retrospective analyses of patients with PH1 who underwent transplantation. Analyses of crude Kaplan–Meier survival curves and adjusted relative hazards from the Cox proportional hazards model were performed. RESULTS: A total of 267 patients with PH1 underwent transplantation between 1978 and 2019. Data of 244 patients (159 CLKTs, 48 isolated KTs, 37 sequential liver–KTs [SLKTs]) were eligible for comparative analyses. Comparing CLKTs with isolated KTs, adjusted mortality was similar in patients with B6-unresponsive genotypes but lower after isolated KT in patients with B6-responsive genotypes (adjusted hazard ratio 0.07, 95% CI: 0.01–0.75, P = 0.028). CLKT yielded higher adjusted event-free survival and death-censored kidney graft survival in patients with B6-unresponsive genotypes (P = 0.025, P < 0.001) but not in patients with B6-responsive genotypes (P = 0.145, P = 0.421). Outcomes for 159 combined procedures versus 37 sequential procedures were comparable. There were 12 patients who underwent pre-emptive liver transplantation (PLT) with poor outcomes. CONCLUSION: The CLKT or SLKT remains the preferred transplantation modality in patients with PH1 with B6-unresponsive genotypes, but isolated KT could be an alternative approach in patients with B6-responsive genotypes

Women’s Perception of Quality of Maternity Services: A Longitudinal Survey in Nepal

Background: In the context of maternity service, the mother’s assessment of quality is central because emotional, cultural and respectful supports are vital during labour and the delivery process. This study compared client-perceived quality of maternity services between birth centres, public and private hospitals in a central hills district of Nepal. Methods: A cohort of 701 pregnant women of 5 months or more gestational age were recruited and interviewed, followed by another interview within 45 days of delivery. Perception of quality was measured by a 20-item scale with three sub-scales: health facility, health care delivery, and interpersonal aspects. Perceived quality scores were analysed by ANOVA with post-hoc comparisons and multiple linear regression.Results: Within the health facility sub-scale, birth centre was rated lowest on items ‘adequacy of medical equipment’, ‘health staff suited to women’s health’ and ‘adequacy of health staff’, whereas public hospital was rated the lowest with respect to ‘adequacy of room’, ‘adequacy of water’, ‘environment clean’, ‘privacy’ and ‘adequacy of information’. Mean scores of total quality and sub-scales health facility and health care delivery for women attending private hospital were higher (p < 0.001) than those using birth centre or public hospital. Mean score of the sub-scale interpersonal aspects for public hospital users was lower (p < 0.001) than those delivered at private hospital and birth centre. However, perception on interpersonal aspects by women using public hospital improved significantly after delivery (p< 0.001). Conclusions: Overall, perception of quality differed significantly by types of health facility used for delivery. They rated lowest the supplies and equipment in birth centres and the amenities and interpersonal aspects in the public hospital. Accordingly, attention to these aspects is needed to improve the quality

A Portuguese East Indiaman from the 1502-1503 Fleet of Vasco da Gama off Al Hallaniyah Island, Oman: An interim report

Two Portuguese naus from Vasco da Gama's second voyage to India, left behind to disrupt maritime trade between India and the Red Sea, were wrecked in May 1503 off the north-eastern coast of Al Hallaniyah Island, Oman. The ships, Esmeralda and São Pedro, had been commanded by da Gama's maternal uncles, Vicente and Brás Sodré, respectively. A detailed study and scientific analysis of an artefact assemblage recovered during archaeological excavations conducted in Al Hallaniyah in 2013 and 2014 confirms the location of an early 16th-century Portuguese wreck-site, initially discovered in 1998. Esmeralda is proposed as the probable source of the remaining, un-salved wreckage