217 research outputs found

    A Scalable & Energy Efficient Graphene-Based Interconnection Framework for Intra and Inter-Chip Wireless Communication in Terahertz Band

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    Network-on-Chips (NoCs) have emerged as a communication infrastructure for the multi-core System-on-Chips (SoCs). Despite its advantages, due to the multi-hop communication over the metal interconnects, traditional Mesh based NoC architectures are not scalable in terms of performance and energy consumption. Folded architectures such as Torus and Folded Torus were proposed to improve the performance of NoCs while retaining the regular tile-based structure for ease of manufacturing. Ultra-low-latency and low-power express channels between communicating cores have also been proposed to improve the performance of conventional NoCs. However, the performance gain of these approaches is limited due to metal/dielectric based interconnection. Many emerging interconnect technologies such as 3D integration, photonic, Radio Frequency (RF), and wireless interconnects have been envisioned to alleviate the issues of a metal/dielectric interconnect system. However, photonic and RF interconnects need the additional physically overlaid optical waveguides or micro-strip transmission lines to enable data transmission across the NoC. Several on-chip antennas have shown to improve energy efficiency and bandwidth of on-chip data communications. However, the date rates of the mm-wave wireless channels are limited by the state-of-the-art power-efficient transceiver design. Recent research has brought to light novel graphene based antennas operating at THz frequencies. Due to the higher operating frequencies compared to mm-wave transceivers, the data rate that can be supported by these antennas are significantly higher. Higher operating frequencies imply that graphene based antennas are just hundred micrometers in size compared to dimensions in the range of a millimeter of mm-wave antennas. Such reduced dimensions are suitable for integration of several such transceivers in a single NoC for relatively low overheads. In this work, to exploit the benefits of a regular NoC structure in conjunction with emerging Graphene-based wireless interconnect. We propose a toroidal folding based NoC architecture. The novelty of this folding based approach is that we are using low power, high bandwidth, single hop direct point to point wireless links instead of multihop communication that happens through metallic wires. We also propose a novel phased based communication protocol through which multiple wireless links can be made active at a time without having any interference among the transceiver. This offers huge gain in terms of performance as compared to token based mechanism where only a single wireless link can be made active at a time. We also propose to extend Graphene-based wireless links to enable energy-efficient, phase-based chip-to-chip communication to create a seamless, wireless interconnection fabric for multichip systems as well. Through cycle-accurate system-level simulations, we demonstrate that such designs with torus like folding based on THz links instead of global wires along with the proposed phase based multichip systems. We provide estimates that they are able to provide significant gains (about 3 to 4 times better in terms of achievable bandwidth, packet latency and average packet energy when compared to wired system) in performance and energy efficiency in data transfer in a NoC as well as multichip system. Thus, realization of these kind of interconnection framework that could support high data rate links in Tera-bits-per-second that will alleviate the capacity limitations of current interconnection framework

    Sterile alpha motif and histidine/aspartic acid domain-containing protein 1 (SAMHD1)-facilitated HIV restriction in astrocytes is regulated by miRNA-181a

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    Background Although highly active antiretroviral therapy (HAART) has significantly reduced the morbidity and mortality in HIV patients, virus continues to reside in the central nervous system (CNS) reservoir. Hence, a complete eradication of virus remains a challenge. HIV productively infects microglia/macrophages, but astrocytes are generally restricted to HIV infection. The relative importance of the possible replication blocks in astrocytes, however, is yet to be delineated. A recently identified restriction factor, sterile alpha motif and histidine/aspartic acid domain-containing protein 1 (SAMHD1), restricts HIV infection in resting CD4+T cells and in monocyte-derived dendritic cells. However, SAMHD1 expression and HIV-1 restriction activity regulation in the CNS cells are unknown. Though, certain miRNAs have been implicated in HIV restriction in resting CD4+T cells, their role in the CNS HIV restriction and their mode of action are not established. We hypothesized that varying SAMHD1 expression would lead to restricted HIV infection and host miRNAs would regulate SAMHD1 expression in astrocytes. Results We found increased SAMHD1 expression and decreased miRNA expression (miR-181a and miR-155) in the astrocytes compared to microglia. We report for the first time that miR-155 and miR-181a regulated the SAMHD1 expression. Overexpression of these cellular miRNAs increased viral replication in the astrocytes, through SAMHD1 modulation. Reactivation of HIV replication was accompanied by decrease in SAMHD1 expression. Conclusions Here, we provide a proof of concept that increased SAMHD1 in human astrocytes is in part responsible for the HIV restriction, silencing of which relieves this restriction. At this time, this concept is of theoretical nature. Further experiments are needed to confirm if HIV replication can be reactivated in the CNS reservoir

    Aspergillus fumigatus cerebral abscess following hemodialysis: A case report

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    Background and Purpose: Cerebral aspergillosis is a notorious disease that causesrapid clinical deterioration and carries a poor prognosis. Therefore, it requires timelydiagnosis and prompt management.Case Report: This study reports a case of fungal cerebral abscess in a 26years old manfollowing hemodialysis,2 months afterdengue-induced acute kidney disease. Aspergillus fumigatus was recovered from a brain abscess specimen that was subjected to a parietal craniotomy. The patient was successfully treated with oral Voriconazole 400mg BD for 2 days, followed by 200 mg BD for 3monthsConclusion: Hemodialysis patients are at high risk offungal infections due to thefrequent use of catheters or the insertion of needles to access the bloodstream. Therefore, a high index of suspicion of fungal infection is required in patients with hemodialysis by the clinician for early diagnosis and treatment

    Vorinostat positively regulates synaptic plasticity genes expression and spine density in HIV infected neurons: role of nicotine in progression of HIV-associated neurocognitive disorder

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    Background HIV-associated neurocognitive disorder (HAND) is characterized by development of cognitive, behavioral and motor abnormalities, and occurs in approximately 50% of HIV infected individuals. In the United States, the prevalence of cigarette smoking ranges from 35-70% in HIV-infected individuals compared to 20% in general population. Cognitive impairment in heavy cigarette smokers has been well reported. However, the synergistic effects of nicotine and HIV infection and the underlying mechanisms in the development of HAND are unknown. Results In this study, we explored the role of nicotine in the progression of HAND using SK-N-MC, a neuronal cell line. SK-N-MC cells were infected with HIV-1 in the presence or absence of nicotine for 7 days. We observed significant increase in HIV infectivity in SK-N-MC treated with nicotine compared to untreated HIV-infected neuronal cells. HIV and nicotine synergize to significantly dysregulate the expression of synaptic plasticity genes and spine density; with a concomitant increase of HDAC2 levels in SK-N-MC cells. In addition, inhibition of HDAC2 up-regulation with the use of vorinostat resulted in HIV latency breakdown and recovery of synaptic plasticity genes expression and spine density in nicotine/HIV alone and in co-treated SK-N-MC cells. Furthermore, increased eIF2 alpha phosphorylation, which negatively regulates eukaryotic translational process, was observed in HIV alone and in co-treatment with nicotine compared to untreated control and nicotine alone treated SK-N-MC cells. Conclusions These results suggest that nicotine and HIV synergize to negatively regulate the synaptic plasticity gene expression and spine density and this may contribute to the increased risk of HAND in HIV infected smokers. Apart from disrupting latency, vorinostat may be a useful therapeutic to inhibit the negative regulatory effects on synaptic plasticity in HIV infected nicotine abusers

    Effect of yield potential, drought escape and drought tolerance on yield of pearl millet (Pennisetum glaucum) in different stress environments

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    An experiment was conducted during the rainy season of 1988 and 1989 and the dry season of 1989 and 1990 to study the effectof yield potential, drought escape and tolerance on the grain yield of pearl millet [Pennisetum glaucum (L.) R. Br. emend.Stuntz] under stress. Different types of drought and heat stress occurred, viz moderate and severe post-flowering drought andsevcrepre-flowecing drought, combined with either high or low temperature during grain filling. Yield potential was onlyrelated to yield under stress when pre-flowering drought was combined with low temperatures. Escape was the predominantfactor if temperature was high, except if combined with pre-flowering drought, in which case tolerance became more important.These results show that for stressed environments, selection for yield potential is of limited use. The importance of escapeand tolerance, however, depends on the timing and intensity of stress occurrence. If pearl millet-growing regions can becharaoterized based on occurrence of abiotic stress, breeders can select more efficiently for plant traits that enhancestress adaptation in specific target environment

    Influence of drying treatments on antioxidant capacity of forage legume leaves

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    This study was aimed to investigate the antioxidant capacities of four common forage legume leaves namely, Arachis pintoi (Pintoi), Calapogonium mucunoides (Calapo), Centrosema pubescens (Centro), and Stylosanthes guanensis (Stylo). Two different drying methods (oven-drying and freeze-drying) were employed and antioxidant activities were determined by DPPH, Ferric Reducing Antioxidant Power (FRAP) and β-carotene bleaching assays. Total phenolic content (TPC) was determined using Folin-Ciocalteu assay. Freeze-dried extract showed the highest antioxidant activities by DPPH (EC50 values 1.17–2.13 mg/ml), FRAP (147.08–246.42 μM of Fe2+/g), and β-carotene bleaching (57.11–78.60%) compared to oven drying. Hence, freeze drying treatment could be considered useful in retention of antioxidant activity and phenolic content

    Valorisation of agricultural biomass‑ash with CO2

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    This work is part of a study of different types of plant-based biomass to elucidate their capacity for valorisation via a managed carbonation step involving gaseous carbon dioxide (co2). the perspectives for broader biomass waste valorisation was reviewed, followed by a proposed closed‑loop process for the valorisation of wood in earlier works. the present work newly focusses on combining agricultural biomass with mineralised co2. Here, the reactivity of selected agricultural biomass ashes with co2 and their ability to be bound by mineralised carbonate in a hardened product is examined. three categories of agricultural biomass residues, including shell, fibre and soft peel, were incinerated at 900 ± 25 °C. The biomass ashes were moistened (10% w/w) and moulded into cylindrical samples and exposed to 100% CO2 gas at 50% RH for 24 h, during which they cemented into hardened monolithic products. the calcia in ashes formed a negative relationship with ash yield and the microstructure of the carbonate‑cementing phase was distinct and related to the particular biomass feedstock. this work shows that in common with woody biomass residues, carbonated agricultural biomass ash‑based monoliths have potential as novel low‑carbon construction products

    Global, regional, and national mortality among young people aged 10–24 years, 1950–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Summary: Background Documentation of patterns and long-term trends in mortality in young people, which reflect huge changes in demographic and social determinants of adolescent health, enables identification of global investment priorities for this age group. We aimed to analyse data on the number of deaths, years of life lost, and mortality rates by sex and age group in people aged 10–24 years in 204 countries and territories from 1950 to 2019 by use of estimates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. Methods We report trends in estimated total numbers of deaths and mortality rate per 100 000 population in young people aged 10–24 years by age group (10–14 years, 15–19 years, and 20–24 years) and sex in 204 countries and territories between 1950 and 2019 for all causes, and between 1980 and 2019 by cause of death. We analyse variation in outcomes by region, age group, and sex, and compare annual rate of change in mortality in young people aged 10–24 years with that in children aged 0–9 years from 1990 to 2019. We then analyse the association between mortality in people aged 10–24 years and socioeconomic development using the GBD Socio-demographic Index (SDI), a composite measure based on average national educational attainment in people older than 15 years, total fertility rate in people younger than 25 years, and income per capita. We assess the association between SDI and all-cause mortality in 2019, and analyse the ratio of observed to expected mortality by SDI using the most recent available data release (2017). Findings In 2019 there were 1·49 million deaths (95% uncertainty interval 1·39–1·59) worldwide in people aged 10–24 years, of which 61% occurred in males. 32·7% of all adolescent deaths were due to transport injuries, unintentional injuries, or interpersonal violence and conflict; 32·1% were due to communicable, nutritional, or maternal causes; 27·0% were due to non-communicable diseases; and 8·2% were due to self-harm. Since 1950, deaths in this age group decreased by 30·0% in females and 15·3% in males, and sex-based differences in mortality rate have widened in most regions of the world. Geographical variation has also increased, particularly in people aged 10–14 years. Since 1980, communicable and maternal causes of death have decreased sharply as a proportion of total deaths in most GBD super-regions, but remain some of the most common causes in sub-Saharan Africa and south Asia, where more than half of all adolescent deaths occur. Annual percentage decrease in all-cause mortality rate since 1990 in adolescents aged 15–19 years was 1·3% in males and 1·6% in females, almost half that of males aged 1–4 years (2·4%), and around a third less than in females aged 1–4 years (2·5%). The proportion of global deaths in people aged 0–24 years that occurred in people aged 10–24 years more than doubled between 1950 and 2019, from 9·5% to 21·6%. Interpretation Variation in adolescent mortality between countries and by sex is widening, driven by poor progress in reducing deaths in males and older adolescents. Improving global adolescent mortality will require action to address the specific vulnerabilities of this age group, which are being overlooked. Furthermore, indirect effects of the COVID-19 pandemic are likely to jeopardise efforts to improve health outcomes including mortality in young people aged 10–24 years. There is an urgent need to respond to the changing global burden of adolescent mortality, address inequities where they occur, and improve the availability and quality of primary mortality data in this age group
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