QoS-aware offloading policies for serverless functions in the Cloud-to-Edge continuum

Function-as-a-Service (FaaS) paradigm is increasingly attractive to bring the benefits of serverless computing to the edge of the network, besides traditional Cloud data centers. However, FaaS adoption in the emerging Cloud-to-Edge Continuum is challenging, mostly due to geographical distribution and heterogeneous resource availability. This emerging landscape calls for effective strategies to trade off low latency at the edge of the network with Cloud resource richness, taking into account the needs of different functions and users. In this paper, we present QoS-aware offloading policies for serverless functions running in the Cloud-to-Edge continuum. We consider heterogeneous functions and service classes, and aim to maximize utility given a monetary budget for resource usage. Specifically, we introduce a two-level approach, where (i) FaaS nodes rely on a randomized policy to schedule every incoming request according to a set of probability values, and (ii) periodically, a linear programming model is solved to determine the probabilities to use for scheduling. We show by extensive simulation that our approach outperforms alternative approaches in terms of generated utility across multiple scenarios. Moreover, we demonstrate that our solution is computationally efficient and can be adopted in large-scale systems. We also demonstrate the functionality of our approach through a proof-of-concept experiment on an open-source FaaS framework

Combined assessment of fluvial-marine sediment transport to determine the impact of coastal risks.

The study of morphological changes of a river channel, linked to erosion-deposition processes, taking place in the riverbed, is a topic of current interest in relation not only to the morphometric variations of the fluvial features (e.g., active channel width, area of sediment bars) and the sedimentary balance of the whole relative hydrographic basin but also in relation to the role of the sediment load transferred downstream up to the near shore area (Figure 1). These sediments constitute the solid transport that is pushed towards the coast and poured into the sea, representing a crucial sedimentary contribution to the beaches volumetric balance. The quantitative estimate of the volume of this fluvial load is currently achievable through robust approaches such as the morphological method grounded in the continuity principle applied to river sediments. To define the transport rates at selected locations (e.g., the river mouth) over a given time period, the method requires to measure the erosion and sedimentation volumes, which can be calculated using repeated Digital Elevation Models (DEM)and deriving a DEM of Difference (DoD) (Vericat et al., 2017; Capito et al., 2023). The coastal sedimentary balance is function of both the sediment load provided by rivers and the quantity of sediment transported by the longshore currents that move parallel to the coastline. For this reason, it is crucial to assess the impact of coastal erosion considering both the sediment input from the hydrographic basins and the longshore transport. Up to now there are no techniques capable of providing continuous and spatially distributed measurement of this sediment transfer, a fact of considerable interest if we think of the anthropic structures present along the shores, and the coast erosional problems. This study aims to evaluate, at the regional scale, the possibility of borrowing some techniques that are often used in fluvial contexts (e.g., geomorphological approach), to estimate the quantity of sediment that nourishes the coast. This information is essential as a preliminary step for further studies on the sediment transport process, considering, for instance, different climatic scenarios. A measured volume of sediments deposited over a specific time interval can be used to calibrate a physically-based sediment erosion and transport model, such as SMART-SED described by Gatti et al., 2023. Following calibration, the model can be employed to predict future scenarios by considering climate projections. An important aspect will be to assess the transferability of such methodologies taking into consideration the technical limitations (e.g., greater difficulty in acquiring bathymetric data in the submerged environment) and the morphodynamic differences of the two contexts (e.g., partial lack of lateral confinement of flows in the marine environment). Once it is established that meaningful estimates can be obtained, using the two solid transport estimates volumes (river and marine) it could be possible to obtain the budget of sediments that could benefit the near shore. This estimation certainly has a margin of error linked to all the uncertainties processes both in the river and coastal contexts, but it reveals an evaluation of sedimentary tendency of a coastal area: retreat, advancement or stationary. Today the studies of coastal balances certainly not considered the presence of submarine morphologies that favorthe sediments deposition (e.g., submerged bars and terraces) or the sediments removal (e.g., submarine canyons that arise very close to the coast) from near shore environment, significantly influencing the trend of longshore currents. In Italy there are many regions in which submarine canyons are very close to the coasts; these structures can act as collectors of sediments which are swallowed up towards greater depths (Lo Presti et al., 2022). Therefore, the quantitative study of sediment volume available on a near shore environment, linked to the presence of submarine morphologies favorable or not to the removal or stasis of sediments and to the intrinsic characteristic of the beach (e.g., long exposed beach, gulf, pocket beach), it constitutes a means of defining the sediment load that moves along a near shore area and which could influence and define possible scenarios of anthropic damage, as ports and fluvial bridges siltation but above coastal erosion risks

Photodinamic therapy with toipical aminolevulinic acid for the treatment of plantar warts

Aim. treatment currently employed for plantar warts (PW) are often painfl and poorly effective. This study evaluates the effect of photodynamic therapy (PDT) with δ-aminolevulinic acid (ALA) on PW. Methods. Before treatment, the superficial hyperkeratotic layer of warts was removed by the application, for 7 days, of an ointment containing 10% urea and 10% salicylic acid. Then, after gentle curettage, a cream containing 20% ALA was applied under occlusive dressing for 3h on 3 patients with 84 warts, while 30 patients with 62 warts (controls) receveid only base cream. Both groups were irradiated using a visible light lamp (range 400-700 n, peaking at 630 nm). The light dose was 50 J/cm2 each session. Patients were followed-up for 12 months. During the treatemtn some patients referred mild burning sensation or slight pain. The absorption of ALA in warts was investigated and demonstrated by in vivo fluorescence spectroscopy. Results. Two months after the last irradiative session, 84.5% of the ALA-PDT treated lesions and 22.5% of controls had resolved. Conclusions. The results of this study suggest that topical ALA-PDT can be considered as alternative treatment for PW

Early cementation and accommodation space dictate the evolution of an overstepping barrier system during the Holocene

The morphology and stratigraphic features of a well-preserved drowned barrier system, located on the western coast of Sardinia (Mediterranean Sea), are presented here. The barriers were mapped using a multibeam echosounder. The Digital Terrain Model of the seabed revealed five sub-parallel barriers in a depth range of 18\u201337 m, with a distance of ~ 300 m between each single barrier. Direct inspection by scuba diving, revealed that the barriers consist of beachrocks, topped by seagrass meadows growing on a biogenic hardground. The inner-most barrier is limited landward by a steep cliff, 10 m high, bordering the back-barrier area. About 200 km of seismic lines were collected along the barrier system using a 0.4\u20131.0 kJ sparker source and a 3.5 kHz Chirp Subbottom profiler. The seismic data, calibrated with vibrocores, allowed us to recognize the subaerial topographic surface of the last glacial maximum as well as several seismic units interpreted as the Pliocene marine sediments, the pre-Holocene deposits and the Holocene barrier\u2013lagoon complex composed of shoreface, barrier, lagoonal/deltaic and beach deposits. Despite the relatively high seabed gradient (0.3\ub0\u20130.4\ub0) and the relatively low rate of sea-level rise (10\u201315 mm y 12 1), the barriers were well preserved due to the early diagenetic processes which led to a rapid cementation with the formation of beachrocks, and the subsequent overstepping with the rise of the sea level. The development of the overstepping barrier system is strictly related to the antecedent subaerial topography which is, in turn, related to the tectonic setting of the area. The Pliocene seismic unit was lowered by a direct fault at the entrance of the gulf forming a depression filled by sediments. The overstepping barrier system developed following the increase of the seabed gradient and was limited landward by the above-mentioned depression which increased the accommodation space. Following the sea-level rise and the barrier formation, this depression was filled by lagoonal sediments, washover fans and sediments coming from the rivers. The age model of barrier evolution, based on previous sea-level-rise curves during the Holocene, supported by radiocarbon data, highlighted that the whole system evolved over a time period of 1 ka; while the time elapsed from this formation to the drowning of single barriers was estimated to be in the order of magnitude of centuries. Scenarios of short-term evolution of modern barrier\u2013lagoon systems of the adjacent coastal sector, under conditions of accelerated sea-level rise, according to Church et al. (2013) (2013 IPCC report) and Rahmstorf (2007) projections, were elaborated. The study of this ancient analogue suggests that the processes of adaptation of coastal systems to the rising sea level would require times evaluable from centuries to millennia

Vitamin D in Prevention of Autoimmune Diseases

Vitamin D is essential for the regulation of the immune system. In recent years, the role of vitamin D in the control of several autoimmune conditions such as inflammatory bowel disease (IBD), celiac disease, type 1 diabetes mellitus (T1DM), and others has been investigated. The aim of this review was to define the level of knowledge on vitamin D's role in these disorders, as well as the preventive and therapeutic role of vitamin D supplementation. Relevant studies published over the last 20 years were identified via a PubMed/Medline (http://www.ncbi.nlm.nih.gov/pubmed/) search using the keywords: vitamin D, autoimmune disease, and prevention. Vitamin D deficiency or impaired function of the enzymes necessary for its activity has been shown to affect the onset and severity of the autoimmune diseases examined. Vitamin D supplementation appears useful in the support therapy of IBD. Its role in celiac disease, autoimmune hepatitis, T1DM, and autoimmune thyroiditis is unclear. In conclusion, further studies are needed to define whether vitamin D is a cause or a result of the most common autoimmune, extra-skeletal diseases, such as IBD. Vitamin D should be provided to all newborns during their first year of life. Afterwards, the vitamin D supplementation regimen should be tailored to the presence of risk factors for vitamin D deficiency and/or specific disease

FIGARO: reinForcement learnInG mAnagement acRoss the computing cOntinuum

The widespread adoption of Artificial Intelligence applications to analyze data generated by Internet of Things sensors leads to the development of the edge computing paradigm. Deploying applications at the periphery of the network effectively addresses cost and latency concerns associated with cloud computing. However, it generates a highly distributed environment with heterogeneous devices, opening the challenges of how to select resources and place application components. Starting from a state-of-the-art design-time tool, we present in this paper a novel framework based on Reinforcement Learning, named FIGARO (reinForcement learnInG mAnagement acRoss the computing cOntinuum). It handles the runtime adaptation of a computing continuum environment, dealing with the variability of the incoming load and service times. To reduce the training time, we exploit the design-time knowledge, achieving a significant reduction in the violations of the response time constraint

Chloride-binding in organic–water mixtures: the powerful synergy of C–H donor groups within a bowl-shaped cavity

2,3,4,5-Tetrafluorobenzyl and imidazolium groups within an open-chain receptor allow for the effective binding of chloride in organic–water solution

Millstones as indicators of relative sea-level changes in northern Sicily and southern Calabria coast lines, Italy

New data are presented for late Holocene relative sea-level changes in two coastal sites of Sicily and Calabria, southern Italy. Reconstructions are based on precise measurements of submerged archaeological remains that are valuable indicators of past sea-level position. The archaeological remains are millstone quarries carved on sandstone coastal rocks and nowadays partially submerged which, to the authors’ knowledge, are used for the first time as sea-level markers. Millstones of similar typology are located on the coast of Capo d’Orlando (northern Sicily) and Capo dell’Armi (southern Calabria). When the archeologically-based sea-level position is compared with the shoreline elevation provided by geological markers (Holocene beachrock, Late Pleistocene marine terraces), a refined understanding of relative sea-level changes and rates of vertical tectonic movements for these coastline locations is gained

A game-theoretic approach to computation offloading in mobile cloud computing

We consider a three-tier architecture for mobile and pervasive computing scenarios, consisting of a local tier ofmobile nodes, a middle tier (cloudlets) of nearby computing nodes, typically located at the mobile nodes access points but characterized by a limited amount of resources, and a remote tier of distant cloud servers, which have practically infinite resources. This architecture has been proposed to get the benefits of computation offloading from mobile nodes to external servers while limiting the use of distant servers whose higher latency could negatively impact the user experience. For this architecture, we consider a usage scenario where no central authority exists and multiple non-cooperative mobile users share the limited computing resources of a close-by cloudlet and can selfishly decide to send their computations to any of the three tiers. We define a model to capture the users interaction and to investigate the effects of computation offloading on the users’ perceived performance. We formulate the problem as a generalized Nash equilibrium problem and show existence of an equilibrium.We present a distributed algorithm for the computation of an equilibrium which is tailored to the problem structure and is based on an in-depth analysis of the underlying equilibrium problem. Through numerical examples, we illustrate its behavior and the characteristics of the achieved equilibria

Double-Framed Thin Elastomer Devices

Elastomers and, in particular, polydimethylsiloxane (PDMS) are widely adopted as biocompatible mechanically compliant substrates for soft and flexible micro-nanosystems in medicine, biology, and engineering. However, several applications require such low thicknesses (e.g., <100 μm) that make peeling-off critical because very thin elastomers become delicate and tend to exhibit strong adhesion with carriers. Moreover, microfabrication techniques such as photolithography use solvents which swell PDMS, introducing complexity and possible contamination, thus limiting industrial scalability and preventing many biomedical applications. Here, we combine low-adhesion and rectangular carrier substrates, adhesive Kapton frames, micromilling-defined shadow masks, and adhesive-neutralizing paper frames for enabling fast, easy, green, contaminant-free, and scalable manufacturing of thin elastomer devices, with both simplified peeling and handling. The accurate alignment between the frame and shadow masks can be further facilitated by micromilled marking lines on the back side of the low-adhesion carrier. As a proof of concept, we show epidermal sensors on a 50 μm-thick PDMS substrate for measuring strain, the skin bioimpedance and the heart rate. The proposed approach paves the way to a straightforward, green, and scalable fabrication of contaminant-free thin devices on elastomers for a wide variety of applications.Elastomers and, in particular, polydimethylsiloxane (PDMS) are widely adopted as biocompatible mechanically compliant substrates for soft and flexible micro-nanosystems in medicine, biology, and engineering. However, several applications require such low thicknesses (e.g., <100 μm) that make peeling-off critical because very thin elastomers become delicate and tend to exhibit strong adhesion with carriers. Moreover, microfabrication techniques such as photolithography use solvents which swell PDMS, introducing complexity and possible contamination, thus limiting industrial scalability and preventing many biomedical applications. Here, we combine low-adhesion and rectangular carrier substrates, adhesive Kapton frames, micromilling-defined shadow masks, and adhesive-neutralizing paper frames for enabling fast, easy, green, contaminant-free, and scalable manufacturing of thin elastomer devices, with both simplified peeling and handling. The accurate alignment between the frame and shadow masks can be further facilitated by micromilled marking lines on the back side of the low-adhesion carrier. As a proof of concept, we show epidermal sensors on a 50 μm-thick PDMS substrate for measuring strain, the skin bioimpedance and the heart rate. The proposed approach paves the way to a straightforward, green, and scalable fabrication of contaminant-free thin devices on elastomers for a wide variety of applications