977 research outputs found
Powering production. The case of the sisal fibre production in the Tanga region, Tanzania
Energy plays a crucial role in economic development. The article presents a framework for the analysis of alternative energy technology mixes in agricultural production and applies it in the context of sisal production in the Tanga region, Tanzania. Through scenario analysis, the paper presents both case-specific and generalizable insights. Case-specific insights show the key role that modern uses of energy and modern agricultural technologies could play in increasing productivity and revenues, in minimizing environmental degradation, and in promoting local development. Generalizable insights demonstrate the value of using sector-specific micro-structural frameworks and scenario analysis for assessing different technologies mixes in the energy and agriculture planning process
Glutathione limits Ero1-dependent oxidation in the endoplasmic reticulum
Many proteins of the secretory pathway contain disulfide bonds that are essential for structure and function. In the endoplasmic reticulum (ER), Ero1alpha and Ero1beta oxidize protein disulfide isomerase (PDI), which in turn transfers oxidative equivalents to newly synthesized cargo proteins. However, oxidation must be limited, as some reduced PDI is necessary for disulfide isomerization and ER-associated degradation. Here we show that in semipermeable cells, PDI is more oxidized, disulfide bonds are formed faster, and high molecular mass covalent protein aggregates accumulate in the absence of cytosol. Addition of reduced glutathione (GSH) reduces PDI and restores normal disulfide formation rates. A higher GSH concentration is needed to balance oxidative folding in semipermeable cells overexpressing Ero1alpha, indicating that cytosolic GSH and lumenal Ero1alpha play antagonistic roles in controlling the ER redox. Moreover, the overexpression of Ero1alpha significantly increases the GSH content in HeLa cells. Our data demonstrate tight connections between ER and cytosol to guarantee redox exchange across compartments: a reducing cytosol is important to ensure disulfide isomerization in secretory proteins
Network Slicing for IEEE 802.11 Wireless Networks
Future networks will pave the way for a myriad of applications with different requirements. In such a context, the today's \emph{one-size-fits-all} approach will not be able to efficiently address the different demands that verticals impose in terms of \gls{qos} and involved data volumes. To this end, network slicing is a new network paradigm which may provide the needed flexibility. It allows to offer multiple logical networks over a common infrastructure, tailored to the services which run on the network.
In today's Wi-Fi networks, all the users are connected to the same wireless channel, which allows service differentiation only at the traffic level. Thus, in this study we propose a standard-compliant network slicing approach for the radio access segment of Wi-Fi, often neglected by the literature on network slicing.
We present two algorithms to realize network slicing at the access level. The first assigns resources according to the requirements of the slices in a static way. On the other hand, the second, more advanced, dynamically configures the slices according to the network conditions and relevant \glspl{kpi}. These techniques can be applied to the IEEE 802.11 standard and, in general, to all the protocols that use \gls{csma} as channel access technique.
The proposed algorithms were validated through extensive simulations, conducted with \emph{ns-3} network simulator and accompanied by theoretical calculations. Particular attention, often neglected in similar simulation-based works, has been paid to the electromagnetic properties of the spectrum, which play a fundamental role in radio communications.
From the conducted simulations, we found that our slicing approaches largely outperform the today's Wi-Fi access technique. They allow to reach higher goodput (i.e. a lower error probability) and lower latency, when needed. At the same time, tailored slicing saves energy to low-power devices and increases the spectrum efficiency
Changes in miRNA Expression Profiling during Neuronal Differentiation and Methyl Mercury-Induced Toxicity in Human in Vitro Models
MicroRNAs (miRNAs) are implicated in the epigenetic regulation of several brain developmental processes, such as neurogenesis, neuronal differentiation, neurite outgrowth and synaptic plasticity. The main aim of this study was to evaluate whether miRNA expression profiling could be a useful approach to detect in vitro developmental neurotoxicity. For this purpose, we assessed the changes in miRNA expression caused by methyl mercury chloride (MeHgCl), a well-known developmental neurotoxicant, comparing carcinoma pluripotent stem cells (NT-2) with human embryonic stem cells (H9), both analyzed during the early stage of neural progenitor commitment into neuronal lineage. The data indicate the activation of two distinct miRNA signatures, one activated upon neuronal differentiation and another upon MeHgCl-induced toxicity. Particularly, exposure to MeHgCl elicited, in both neural models, the down-regulation of the same six out of the ten most upregulated neuronal pathways, as shown by the up-regulation of the corresponding miRNAs and further assessment of gene ontology (GO) term and pathway enrichment analysis. Importantly, some of these common miRNA-targeted pathways defined in both cell lines are known to play a role in critical developmental processes, specific for neuronal differentiation, such as axon guidance and neurotrophin-regulated signaling. The obtained results indicate that miRNAs expression profiling could be a promising tool to assess developmental neurotoxicity pathway perturbation, contributing towards improved predictive human toxicity testing.JRC.I.5 - Systems Toxicolog
Blood oxygen level-dependent cerebrovascular reactivity (BOLD-CVR) and non-invasive optimal vascular analysis (NOVA) hemodynamic imaging in patients with Moyamoya vasculopathy undergoing bypass surgery
Surgical revascularization of the symptomatic hemisphere is an effective treatment option in patients with moyamoya vasculopathy and ischemic symptoms. However, a careful patient selection is mandatory. Ideally, such selection should be supported by multimodal hemodynamic and flow imaging. Recently, two novel quantitative techniques have been introduced and are increasingly used in evaluating patients with steno-occlusive disease: 1) Blood oxygenation level-dependent functional MRI (BOLD-fMRI) to assess cerebrovascular reactivity (CVR) of brain parenchyma and 2) quantitative magnetic resonance angiography (qMRA) with non-invasive optimal vessel analysis (NOVA) to measure the volume flow rate (VFR) of large intracranial arteries. The purpose of this study is to present the results of BOLD-CVR and qMRA-NOVA imaging as well as the changes in cerebral hemodynamics and flow status after surgical revascularization with STA-MCA bypass in our cohort of patients with Moyamoya vasculopathy
Exposure and connectedness to natural environments: An examination of the measurement invariance of the Nature Exposure Scale (NES) and Connectedness to Nature Scale (CNS) across 65 nations, 40 languages, gender identities, and age groups
Reporting Rules for U.S. and International Lawyers Under Sarbanes-Oxley: Exporting an Unfinished Product?
The cost of cooking a meal. The case of Nyeri County, Kenya
Energy for cooking is considered essential in achieving modern energy access. Despite this, almost three billion people worldwide still use solid fuels to meet their cooking needs. To better support practitioners and policy-makers, this paper presents a new model for comparing cooking solutions and its key output metric: the 'levelized cost of cooking a meal' (LCCM). The model is applied to compare several cooking solutions in the case study area of Nyeri County in Kenya. The cooking access targets are connected to the International Workshop Agreement and Global Tracking Framework's tiers of cooking energy access. Results show how an increased energy access with improved firewood and charcoal cookstoves could reduce both household's LCCMs and the total costs compared to traditional firewood cooking over the modelling period. On the other hand, switching to cleaner cooking solutions, such as LPG- and electricity, would result in higher costs for the end-user highlighting that this transition is not straightforward. The paper also contextualizes the results into the wider socio-economic context. It finds that a tradeoff is present between minimizing costs for households and meeting household priorities, thus maximizing the potential benefits of clean cooking without dismissing the use of biomass altogether
5G Network Slicing for Wi-Fi Networks
Future networks will pave the way for a myriad of applications with different requirements and Wi-Fi will play an important role in local area networks. This is why network slicing is proposed by 5G networks, allowing to offer multiple logical networks tailored to the different user requirements, over a common infrastructure. However, this is not supported by current Wi-Fi networks. In this paper, we propose a standard-compliant network slicing approach for the radio access segment of Wi-Fi by defining multiple Service Set Identifiers (SSIDs) per Access Point (AP). We present two algorithms, one that assigns resources according to the requirements of slices in a static way, and another that dynamically configures the slices according to the network’s conditions and relevant Key Performance Indicators (KPIs). The proposed algorithms were validated through extensive simulations, conducted in the ns-3 network simulator, and complemented by theoretical assessments. The obtained results reveal that the two proposed slicing approaches outperform today’s Wi-Fi access technique, reaching lower error probability for bandwidth intensive slices and lower latency for time-critical slices. Simultaneously, the proposed approach is up to 32 times more energy efficient, when considering slices tailored for lowpower and low-bandwidth devices, while increasing the overall spectrum efficiency.publishedVersio
- …
