99 research outputs found
Towards virtual machine integrity using introspection
The Integrity Measurements Architecture (IMA) provides attestation and integrity for Linux hosts. But what if an administrator wants to provide IMA functionality to an older (non-IMA capable) or a non Linux-based OS? If the system is deployed on top of a hypervisor, IMA functionality can be provided at the hypervisor level. This paper applies Virtual Machine Introspection (VMI) to provide IMA functionality to virtualized guest OSes. We implement a proof of concept library (using a shallow shadow filesystem) and integrate it with the Kernel-based Virtual Machine (KVM) hypervisor. The modifications provide the Linux host OS the ability to see when and what files are being accessed by the guest OS. This paper outlines the approach to its design, concept of execution, and describes the challenges encountered. The library is tested with a sample bash script created in a monitored partition; a hash of the file is printed before the file is loaded into memory
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Precision cancer monitoring using a novel, fully integrated, microfluidic array partitioning digital PCR platform.
A novel digital PCR (dPCR) platform combining off-the-shelf reagents, a micro-molded plastic microfluidic consumable with a fully integrated single dPCR instrument was developed to address the needs for routine clinical diagnostics. This new platform offers a simplified workflow that enables: rapid time-to-answer; low potential for cross contamination; minimal sample waste; all within a single integrated instrument. Here we showcase the capability of this fully integrated platform to detect and quantify non-small cell lung carcinoma (NSCLC) rare genetic mutants (EGFR T790M) with precision cell-free DNA (cfDNA) standards. Next, we validated the platform with an established chronic myeloid leukemia (CML) fusion gene (BCR-ABL1) assay down to 0.01% mutant allele frequency to highlight the platform's utility for precision cancer monitoring. Thirdly, using a juvenile myelomonocytic leukemia (JMML) patient-specific assay we demonstrate the ability to precisely track an individual cancer patient's response to therapy and show the patient's achievement of complete molecular remission. These three applications highlight the flexibility and utility of this novel fully integrated dPCR platform that has the potential to transform personalized medicine for cancer recurrence monitoring
SatCat5: A Low-Power, Mixed-Media Ethernet Network for Smallsats
In any satellite, internal bus and payload systems must exchange a variety of command, control, telemetry, and mission-data. In too many cases, the resulting network is an ad-hoc proliferation of complex, dissimilar protocols with incomplete system-to-system connectivity. While standards like CAN, MIL-STD-1553, and SpaceWire mitigate this problem, none can simultaneously solve the need for high throughput and low power consumption.
We present a new solution that uses Ethernet framing and addressing to unify a mixed-media network. Low-speed nodes (0.1-10 Mbps) use simple interfaces such as SPI and UART to communicate with extremely low power and minimal complexity. High-speed nodes use so-called “media-independent” interfaces such as RMII, RGMII, and SGMII to communicate at rates up to 1000 Mbps and enable connection to traditional COTS network equipment. All are interconnected into a single smallsat-area-network using a Layer-2 network switch, with mixed-media support for all these interfaces on a single network. The result is fast, easy, and flexible communication between any two subsystems.
SatCat5 is presented as a free and open-source reference implementation of this mixed-media network switch, with power consumption of 0.2-0.7W depending on network activity. Further discussion includes example protocols that can be used on such networks, leveraging IPv4 when suitable but also enabling full-featured communication without the need for a complex protocol stack
Considerations for Master Protocols Using External Controls
There has been an increasing use of master protocols in oncology clinical
trials because of its efficiency and flexibility to accelerate cancer drug
development. Depending on the study objective and design, a master protocol
trial can be a basket trial, an umbrella trial, a platform trial, or any other
form of trials in which multiple drugs and/or multiple subpopulations are
studied in parallel under a single protocol. External data and evidence (EDE)
can be used in the design and analysis of master protocols such as external
controls for treatment effect estimation, which can further improve efficiency
of the master protocol trial. This paper provides an overview of different
types of external controls and their unique features when used in master
protocols. Some key considerations in master protocols with external controls
are discussed including construction of estimands and assessment of fit-for-use
real-world data. A targeted learning-based causal roadmap is presented which
constitutes three key steps: (1) define a target statistical estimand that
aligns with the causal estimand for the study objective, (2) use an efficient
estimator to estimate the target statistical estimand and its uncertainty, and
(3) evaluate the impact of causal assumptions on the study conclusion by
performing a sensitivity analysis. Two illustrative examples are provided for
master protocols using external controls
In-Band Asymmetry Compensation for Accurate Time/Phase Transport over Optical Transport Network
The demands of precise time/phase synchronization have been increasing recently due to the next generation of telecommunication synchronization. This paper studies the issues that are relevant to distributing accurate time/phase over optical transport network (OTN). Each node and link can introduce asymmetry, which affects the adequate time/phase accuracy over the networks. In order to achieve better accuracy, protocol level full timing support is used (e.g., Telecom-Boundary clock). Due to chromatic dispersion, the use of different wavelengths consequently causes fiber link delay asymmetry. The analytical result indicates that it introduces significant time error (i.e., phase offset) within 0.3397 ns/km in C-band or 0.3943 ns/km in L-band depending on the wavelength spacing. With the proposed scheme in this paper, the fiber link delay asymmetry can be compensated relying on the estimated mean fiber link delay by the Telecom-Boundary clock, while the OTN control plane is responsible for processing the fiber link delay asymmetry to determine the asymmetry compensation in the timing chain
The Effects of a Glutamine-Free Diet on Tumor Progression and the Immune Landscape of the Ovarian Tumor Microenvironment
https://openworks.mdanderson.org/sumexp23/1053/thumbnail.jp
A Preliminary Psychometric Investigation of a Chinese Version of the Engaged Teachers Scale (C-ETS)
This study examines the psychometric properties of a Chinese version of the Engaged Teacher Scale (C-ETS). A translated questionnaire with 16 items was administered to a sample of 341 primary and secondary school teachers in Hong Kong. A series of confirmatory factor analyses were performed to assess the construct, convergent, and discriminant validity of the scale in alternative models. Results provide support for a second-order model with teacher engagement as an overarching construct with four hypothesized dimensions: emotional engagement, cognitive engagement, social engagement (students), and social engagement (colleagues). The C-ETS provides a useful measure for teacher engagement in Chinese societies. Contributions and limitations of the study are discussed
Synthesis and Characterization of Metal Hydride/Carbon Aerogel Composites for Hydrogen Storage
Two materials currently of interest for onboard lightweight hydrogen storage applications are sodium aluminum hydride (NaAlH4), a complex metal hydride, and carbon aerogels (CAs), a light porous material connected by several spherical nanoparticles. The objectives of the present work have been to investigate the synthesis, characterization, and hydrogenation behavior of Pd-, Ti- or Fe-doped CAs, NaAlH4, and MgH2 nanocomposites. The diameters of Pd nanoparticles onto CA’s surface and BET surface area of CAs were 3–10 nm and 700–900 m2g−1, respectively. The H2 storage capacity of metal hydrides has been studied using high-pressure TGA microbalance and they were 4.0, 2.7, 2.1, and 1.2 wt% for MgH2-FeTi-CAs, MgH2-FeTi, CAs-Pd, and 8 mol% Ti-doped NaAlH4, respectively, at room temperature. Carbon aerogels with higher surface area and mesoporous structures facilitated hydrogen diffusion and adsorption, which accounted for its extraordinary hydrogen storage phenomenon. The hydrogen adsorption abilities of CAs notably increased after inclusion of metal hydrides by the “hydrogen spillover” mechanisms
Effects of Single and Integrated Water, Sanitation, Handwashing, and Nutrition Interventions on Child Soil-Transmitted Helminth and Giardia infections: A Cluster-Randomized Controlled Trial in Rural Kenya
Helminth and protozoan infections affect more than 1 billion children globally. Improving water quality, sanitation, handwashing, and nutrition could be more sustainable control strategies for parasite infections than mass drug administration, while providing other quality of life benefits
Cluster-randomised controlled trials of individual and combined water, sanitation, hygiene and nutritional interventions in rural Bangladesh and Kenya: the WASH Benefits study design and rationale.
INTRODUCTION: Enteric infections are common during the first years of life in low-income countries and contribute to growth faltering with long-term impairment of health and development. Water quality, sanitation, handwashing and nutritional interventions can independently reduce enteric infections and growth faltering. There is little evidence that directly compares the effects of these individual and combined interventions on diarrhoea and growth when delivered to infants and young children. The objective of the WASH Benefits study is to help fill this knowledge gap. METHODS AND ANALYSIS: WASH Benefits includes two cluster-randomised trials to assess improvements in water quality, sanitation, handwashing and child nutrition-alone and in combination-to rural households with pregnant women in Kenya and Bangladesh. Geographically matched clusters (groups of household compounds in Bangladesh and villages in Kenya) will be randomised to one of six intervention arms or control. Intervention arms include water quality, sanitation, handwashing, nutrition, combined water+sanitation+handwashing (WSH) and WSH+nutrition. The studies will enrol newborn children (N=5760 in Bangladesh and N=8000 in Kenya) and measure outcomes at 12 and 24 months after intervention delivery. Primary outcomes include child length-for-age Z-scores and caregiver-reported diarrhoea. Secondary outcomes include stunting prevalence, markers of environmental enteropathy and child development scores (verbal, motor and personal/social). We will estimate unadjusted and adjusted intention-to-treat effects using semiparametric estimators and permutation tests. ETHICS AND DISSEMINATION: Study protocols have been reviewed and approved by human subjects review boards at the University of California, Berkeley, Stanford University, the International Centre for Diarrheal Disease Research, Bangladesh, the Kenya Medical Research Institute, and Innovations for Poverty Action. Independent data safety monitoring boards in each country oversee the trials. This study is funded by a grant from the Bill & Melinda Gates Foundation to the University of California, Berkeley. REGISTRATION: Trial registration identifiers (http://www.clinicaltrials.gov): NCT01590095 (Bangladesh), NCT01704105 (Kenya)
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