Background: Zinc, selenium, and vitamin C are vital antioxidants that mitigate oxidative stress. Pregnancy-induced metabolic changes may alter their levels, affecting maternal and fetal health. Aim: This study evaluated zinc, selenium, and vitamin C concentrations in maternal and umbilical cord blood of women in labor in Enugu Metropolis, Nigeria. Methods: A cross-sectional study was conducted among 48 mother-neonate pairs. Maternal and umbilical cord blood samples (5 mL each) were collected postpartum. Zinc and selenium were analyzed using atomic absorption spectrophotometry, while vitamin C was measured colorimetrically. Results: Mean maternal and cord serum zinc levels were 41.61 ± 2.45 µg/dL and 42.65 ± 4.7 µg/dL, respectively, indicating deficiency. Selenium averaged 168.10 ± 14.47 µg/L in maternal serum and 197.56 ± 16.74 µg/L in cord blood, with neonatal levels exceeding physiological limits. Vitamin C concentrations were 7.53 ± 0.26 mg/L (maternal) and 7.11 ± 0.50 mg/L (cord), both within normal ranges. Correlation analysis showed a weak maternal-cord zinc relationship (r = 0.11, P = 0.46), a significant positive correlation for selenium (r = 0.48, P = 0.00059), and a slight negative correlation for vitamin C (r = −0.022, P = 0.88). Conclusion: Zinc deficiency in maternal and cord blood highlights the need for routine monitoring and supplementation. Elevated neonatal selenium suggests potential toxicity risks, requiring further research. Adequate vitamin C levels indicate sufficient nutrition, supporting immune function and oxidative stress reduction. These findings emphasize the importance of maternal micronutrient balance for neonatal health.
In the case of compute-intensive machine learning, efficient operating system scheduling is crucial for performance and energy efficiency. This paper conducts a comparative study over FIFO(First-In-First-Out) and RR(Round-Robin) scheduling policies with the application of real-time machine learning training processes and data pipelines on Ubuntu-based systems. Knowing a few patterns of CPU usage and energy consumption, we identify which policy (the exclusive or the shared) provides higher performance and/or lower energy consumption for typical modern workloads. Results of this study would help in providing better operating system schedulers for modern systems like Ubuntu, working to improve performance and reducing energy consumption in compute intensive workloads.
Stefan Wallentowitz, Bastian Kersting, Dan Mihai Dumitriu
Application virtual machines provide strong isolation properties and are established in the context of software portability. Those opportunities make them interesting for scalable and secure IoT deployments. WebAssembly is an application virtual machine with origins in web browsers, that is getting rapidly adopted in other domains. The strong and steadily growing ecosystem makes WebAssembly an interesting candidate for Embedded Systems. This position paper discusses the usage of WebAssembly in Embedded Systems. After introducing the basic concepts of WebAssembly and existing runtime environments, we give an overview of the challenges for the efficient usage of WebAssembly in Embedded Systems. The paper concludes with a real world case study that demonstrates the viability, before giving an outlook on open issues and upcoming work.
Alain Tchana, Raphael Colin, Adrien Le Berre
et al.
The General Data Protection Regulation (GDPR) forces IT companies to comply with a number of principles when dealing with European citizens' personal data. Non-compliant companies are exposed to penalties which may represent up to 4% of their turnover. Currently, it is very hard for companies driven by personal data to make their applications GDPR-compliant, especially if those applications were developed before the GDPR was established. We present rgpdOS, a GDPR-aware operating system that aims to bring GDPR-compliance to every application, while requiring minimal changes to application code.
A conventional data center that consists of monolithic-servers is confronted with limitations including lack of operational flexibility, low resource utilization, low maintainability, etc. Resource disaggregation is a promising solution to address the above issues. We propose a concept of disaggregated cloud data center architecture called Flow-in-Cloud (FiC) that enables an existing cluster computer system to expand an accelerator pool through a high-speed network. FlowOS-RM manages the entire pool resources, and deploys a user job on a dynamically constructed slice according to a user request. This slice consists of compute nodes and accelerators where each accelerator is attached to the corresponding compute node. This paper demonstrates the feasibility of FiC in a proof of concept experiment running a distributed deep learning application on the prototype system. The result successfully warrants the applicability of the proposed system.
Oliver Horst, Johannes Wiesböck, Raphael Wild
et al.
An important characteristic of cyber-physical systems is their capability to respond, in-time, to events from their physical environment. However, to the best of our knowledge there exists no benchmark for assessing and comparing the interrupt handling performance of different software stacks. Hence, we present a flexible evaluation method for measuring the interrupt latency and throughput on ARMv8-A based platforms. We define and validate seven test-cases that stress individual parts of the overall process and combine them to three benchmark functions that provoke the minimal and maximal interrupt latency, and maximal interrupt throughput.
The utilization of paging for virtual machine (VM) memory management is the root cause of memory virtualization overhead. This paper shows that paging is not necessary in the hypervisor. In fact, memory fragmentation, which explains paging utilization, is not an issue in virtualized datacenters thanks to VM memory demand patterns. Our solution Compromis, a novel Memory Management Unit, uses direct segment for VM memory management combined with paging for VM's processes. The paper presents a systematic methodology for implementing Compromis in the hardware, the hypervisor and the datacenter scheduler. Evaluation results show that Compromis outperforms the two popular memory virtualization solutions: shadow paging and Extended Page Table by up to 30% and 370% respectively.
Modern FaaS systems perform well in the case of repeat executions when function working sets stay small. However, these platforms are less effective when applied to more complex, large-scale and dynamic workloads. In this paper, we introduce SEUSS (serverless execution via unikernel snapshot stacks), a new system-level approach for rapidly deploying serverless functions. Through our approach, we demonstrate orders of magnitude improvements in function start times and cacheability, which improves common re-execution paths while also unlocking previously-unsupported large-scale bursty workloads.
Solid state drives have a number of interesting characteristics. However, there are numerous file system and storage design issues for SSDs that impact the performance and device endurance. Many flash-oriented and flash-friendly file systems introduce significant write amplification issue and GC overhead that results in shorter SSD lifetime and necessity to use the NAND flash overprovisioning. SSDFS file system introduces several authentic concepts and mechanisms: logical segment, logical extent, segment's PEBs pool, Main/Diff/Journal areas in the PEB's log, Diff-On-Write approach, PEBs migration scheme, hot/warm data self-migration, segment bitmap, hybrid b-tree, shared dictionary b-tree, shared extents b-tree. Combination of all suggested concepts are able: (1) manage write amplification in smart way, (2) decrease GC overhead, (3) prolong SSD lifetime, and (4) provide predictable file system's performance.
Efficient, reliable trapping of execution in a program at the desired location is a linchpin technique for dynamic malware analysis. The progression of debuggers and malware is akin to a game of cat and mouse - each are constantly in a state of trying to thwart one another. At the core of most efficient debuggers today is a combination of virtual machines and traditional binary modification breakpoints (int3). In this paper, we present a design for Virtual Breakpoints. a modification to the x86 MMU which brings breakpoint management into hardware alongside page tables. In this paper we demonstrate the fundamental abstraction failures of current trapping methods, and design a new mechanism from the hardware up. This design incorporates lessons learned from 50 years of virtualization and debugger design to deliver fast, reliable trapping without the pitfalls of traditional binary modification.
This paper presents the study of part of the dispute process around the Audiovisual Communication Services law in the argentine public space during the year 2009. Specifically, it shows how the signification of democracy was configured in the Regional Participatory Forums of Public Consultation (FPCP) organized by the Federal Broadcasting Committee (COMFER) which were held during 2009 as a previous stage to the presentation of the Audiovisual Communication Services Bill. Thus, from the analysis of the interventions in the FPCP, the paper presents the emergence of democracy as democratic gradualness configured in three analytical dimensions: what democracy is not, democracy as plurality, and democracy as participation.
Vyacheslav Dubeyko, Cyril Guyot, Luis Cargnini
et al.
Modern Operating Systems are typically POSIX-compliant. The system calls are the fundamental layer of interaction between user-space applications and the OS kernel and its implementation of fundamental abstractions and primitives used in modern computing. The next generation of NVM/SCM memory raises critical questions about the efficiency of modern OS architecture. This paper investigates how the POSIX API drives performance for a system with NVM/SCM memory. We show that OS and metadata related system calls represent the most important area of optimization. However, the synchronization related system calls (poll(), futex(), wait4()) are the most time-consuming overhead that even a RAMdisk platform fails to eliminate. Attempting to preserve the POSIX-based approach will likely result in fundamental inefficiencies for any future applications of NVM/SCM memory.
Disaggregating resources in data centers is an emerging trend. Recent work has begun to explore memory disaggregation, but suffers limitations including lack of consideration of the complexity of cloud-based deployment, including heterogeneous hardware and APIs for cloud users and operators. In this paper, we present FluidMem, a complete system to realize disaggregated memory in the datacenter. Going beyond simply demonstrating remote memory is possible, we create an entire Memory as a Service. We define the requirements of Memory as a Service and build its implementation in Linux as FluidMem. We present a performance analysis of FluidMem and demonstrate that it transparently supports remote memory for standard applications such as MongoDB and genome sequencing applications.
Reseña del libro:Guerrero, Mauricio (ed.) (2014). Objetos públicos, espacios privados. Usuarios y relaciones sociales en tres centros comerciales de Santiago de Cali. Cali: Universidad Icesi, pp. 158.
Nathan Fisher, Joël Goossens, Pradeep M. Hettiarachchi
et al.
In this work, we investigate the potential utility of parallelization for meeting real-time constraints and minimizing energy. We consider malleable Gang scheduling of implicit-deadline sporadic tasks upon multiprocessors. We first show the non-necessity of dynamic voltage/frequency regarding optimality of our scheduling problem. We adapt the canonical schedule for DVFS multiprocessor platforms and propose a polynomial-time optimal processor/frequency-selection algorithm. We evaluate the performance of our algorithm via simulations using parameters obtained from a hardware testbed implementation. Our algorithm has up to a 60 watt decrease in power consumption over the optimal non-parallel approach.
Virtualization is a term that refers to the abstraction of computer resources. The purpose of virtual computing environment is to improve resource utilization by providing a unified integrated operating platform for users and applications based on aggregation of heterogeneous and autonomous resources. More recently, virtualization at all levels (system, storage, and network) became important again as a way to improve system security, reliability and availability, reduce costs, and provide greater flexibility. Virtualization has rapidly become a go-to technology for increasing efficiency in the data center. With virtualization technologies providing tremendous flexibility, even disparate architectures may be deployed on a single machine without interference This paper explains the basics of server virtualization and addresses pros and cons of virtualization
Operating system is a bridge between system and user. An operating system (OS) is a software program that manages the hardware and software resources of a computer. The OS performs basic tasks, such as controlling and allocating memory, prioritizing the processing of instructions, controlling input and output devices, facilitating networking, and managing files. It is difficult to present a complete as well as deep account of operating systems developed till date. So, this paper tries to overview only a subset of the available operating systems and its different categories. OS are being developed by a large number of academic and commercial organizations for the last several decades. This paper, therefore, concentrates on the different categories of OS with special emphasis to those that had deep impact on the evolution process. The aim of this paper is to provide a brief timely commentary on the different categories important operating systems available today.
Race condition is a timing sensitive problem. A significant source of timing variation comes from nondeterministic hardware interactions such as cache misses. While data race detectors and model checkers can check races, the enormous state space of complex software makes it difficult to identify all of the races and those residual implementation errors still remain a big challenge. In this paper, we propose deterministic real-time scheduling methods to address scheduling nondeterminism in uniprocessor systems. The main idea is to use timing insensitive deterministic events, e.g, an instruction counter, in conjunction with a real-time clock to schedule threads. By introducing the concept of Worst Case Executable Instructions (WCEI), we guarantee both determinism and real-time performance.