Fibre Channel Switch Modeling at Fibre Channel-2 Level for Large Fabric Storage Area Network Simulations using OMNeT++

Abstract—Typically, in the current enterprise data centers dedicated fabrics or networks are implemented to meet their LAN, Inter-Processor communication and storage traffic requirements. The storage traffic requirements of a group of servers are met through multiple storage area networks based on fibre channel, which has become the standard connection type. Typically, this fibre channel storage area networks are small (maximum of 32 switches/directors in a single fabric) and do not experience any scaling, stability and other performance issues.The advent of I/O consolidation in enterprise data centers for multiple traffic types to converge on to a single fabric or network (typically Ethernet platform) to reduce hardware, energy and management costs has also the potential to allow implementation of large storage area networks based on the fibre channel standards. Large storage area networks are being planned with more than two hundred switches/directors in a single fabric or network in addition to servers and storages connected to the fabric on Ethernet platforms. Even though these large storage area networks are envisioned to operate on Ethernet platform, they still have to satisfy the stringent operating and performance requirement set forth by the fibre channel standards. The two important issues of concern with large storage area networks are scaling and stability. The scaling and stability issues are dependent on the interactions and performance capabilities of various fabric servers located on each switch/director in the fabric in order to provide fabric services. In order to determine the extent of scaling and stability issues of a large fabric first the detailed models of the switch/director addressing the operations of the individual fabric servers are required. Next, the interactions of the switches/directors using the detailed models are to be simulated to study the scaling and stability issues.In this paper, the detailed modeling of the fibre channel switch and the fabric servers using the OMNeT++ discrete event simulator is presented first. Detailed models are developed addressing the behavior of the switch at the level-2 of the fibre channel protocol since this layer addresses the requirements and operations of various mandatory fabric services like fabric build, directory, login, nameserver, management, etc. Next, using the OMNET++ discrete event simulator large fabrics are simulated. The results from the simulation are compared against the test bed traffic and the accuracy is demonstrated. Also, results and analysis of multiple simulations with increasing fabric size are presented

STAT3 gain-of-function mutations connect leukemia with autoimmune disease by pathological NKG2Dhi CD8+T cell dysregulation and accumulation

The association between cancer and autoimmune disease is unexplained, exemplified by T cell large granular lymphocytic leukemia (T-LGL) where gain-of-function (GOF) somatic STAT3 mutations correlate with co -exist-ing autoimmunity. To investigate whether these mutations are the cause or consequence of CD8+ T cell clonal expansions and autoimmunity, we analyzed patients and mice with germline STAT3 GOF mutations. STAT3 GOF mutations drove the accumulation of effector CD8+ T cell clones highly expressing NKG2D, the receptor for stress-induced MHC-class-I-related molecules. This subset also expressed genes for granzymes, perforin, interferon-y, and Ccl5/Rantes and required NKG2D and the IL-15/IL-2 receptor IL2RB for maximal accumula-tion. Leukocyte-restricted STAT3 GOF was sufficient and CD8+ T cells were essential for lethal pathology in mice. These results demonstrate that STAT3 GOF mutations cause effector CD8+ T cell oligoclonal accumu-lation and that these rogue cells contribute to autoimmune pathology, supporting the hypothesis that somatic mutations in leukemia/lymphoma driver genes contribute to autoimmune disease.Peer reviewe

Taxonomy based on science is necessary for global conservation

Peer reviewe

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

OFDM AND SOQPSK TRANSCEIVER HARDWARE IMPLEMENTATION WITH PRELIMINARY RESULTS

This paper presents a hardware implementation of a transceiver capable of both orthogonal frequency-division multiplexing (OFDM) and shaped-offset quadrature phase shift keying (SOQPSK) transmissions using a dataflow programming language. Based on the physical layer iNET standard, we introduce a transceiver implementation that utilizes both waveforms with low density parity check (LDPC) forward error correction (FEC) codes. This testbed is intended to test and enable an adaptive algorithm that uses both waveforms as its modulation schemes. As such, it has the ability to dynamically select various modulation parameters and coding rates. The hardware implementations are described and performance utilizations are presented.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

LINK QUALITY METRICS FOR ADAPTIVE CODING AND MODULATION WITH SOQPSK AND OFDM

In previous work, we presented a link quality metric for adaptive modulation and coding of two standard telemetry waveforms, orthogonal frequency-division multiplexing (OFDM) and shaped-offset quadrature phase shift keying (SOQPSK). That metric unified error vector magnitude (EVM) and Godard dispersion, for OFDM and SOQPSK, respectively, in the contexts of additive white Gaussian noise (AWGN) channels. In this paper, we present an alternative metric based on low density parity check (LDPC) decoding iterations. We show this new metric to be an equally effective substitute for AWGN channels but also to be applicable to a wider variety of channels, including those with multipath and interference. Furthermore, we show the metric to be robust within sub-optimal, lower complexity receiver architectures.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

Obligatory role of hyperaemia and shear stress in microvascular adaptation to repeated heating in humans

The endothelium, a single layer of cells lining the entire circulatory system, plays a key role in maintaining vascular health. Endothelial dysfunction independently predicts cardiovascular events and improvement in endothelial function is associated with decreased vascular risk. Previous studies have suggested that exercise training improves endothelial function in macrovessels, a benefit mediated via repeated episodic increases in shear stress. However, less is known of the effects of shear stress modulation in microvessels. In the present study we examined the hypothesis that repeated skin heating improves cutaneous microvascular vasodilator function via a shear stress-dependent mechanism. We recruited 10 recreationally active males who underwent bilateral forearm immersion in warm water (42°C), 3 times per week for 30 min. During these immersion sessions, shear stress was manipulated in one arm by inflating a pneumatic cuff to 100 mmHg, whilst the other arm remained uncuffed. Vasodilatation to local heating, a NO-dependent response assessed using laser Doppler, improved across the 8 week intervention period in the uncuffed arm (cutaneous vascular conductance week 0 vs. week 4 at 41°C: 1.37 ± 0.45 vs. 2.0 ± 0.91 units, P= 0.04; 42°C: 2.06 ± 0.45 vs. 2.68 ± 0.83 units; P= 0.04), whereas no significant changes were evident in the cuffed arm. We conclude that increased blood flow, and the likely attendant increase in shear stress, is a key physiological stimulus for enhancing microvascular vasodilator function in humans