4,846 research outputs found

    Poplar from phytoremediation as a renewable energy source:gasification properties and pollution analysis

    Get PDF
    Biomass gasification is a very efficient process to produce clean energy in the form of a fuel gas (syngas). Hazelnut shells and poplar have good energy production potential and they are abundant in nature. Hazelnut shells have the characteristics of a very good fuel and poplar is among the fastest growing trees; furthermore, poplar demonstrated the capability to absorb organic contaminants (i.e. heavy metals) from the soil in which they are cultivated. However, poplar is not usually used for biomass gasification and its potential is not fully assessed. Here, 3 types of biomass, hazelnut shells (HS), simple poplar (P) and poplar coming from a phytoremediation procedure (PHYP), were chosen as representative samples to be characterized and tested in a steam gasification process carried out on a bench scale fluidized bed gasifier. A comparison is reported on gasification results, such as gas composition, tar production and gas yield for the biomass feedstocks mentioned above. It was concluded that hazelnut shells and poplar (P and PHYP) could be easily gasified in a fluidized bed gasifier, thus producing a good quality gas with low polluting by-products. The PHYP sample showed lower tar content and higher gas yield. It is guessed that Ca and Mg, found in higher quantities in the PHYP sample, could have had a catalytic effect in tar reforming thus producing lower quantity of heavy hydrocarbons

    What does it take to evolve behaviorally complex organisms?

    Get PDF
    What genotypic features explain the evolvability of organisms that have to accomplish many different tasks? The genotype of behaviorally complex organisms may be more likely to encode modular neural architectures because neural modules dedicated to distinct tasks avoid neural interference, i.e., the arrival of conflicting messages for changing the value of connection weights during learning. However, if the connection weights for the various modules are genetically inherited, this raises the problem of genetic linkage: favorable mutations may fall on one portion of the genotype encoding one neural module and unfavorable mutations on another portion encoding another module. We show that this can prevent the genotype from reaching an adaptive optimum. This effect is different from other linkage effects described in the literature and we argue that it represents a new class of genetic constraints. Using simulations we show that sexual reproduction can alleviate the problem of genetic linkage by recombining separate modules all of which incorporate either favorable or unfavorable mutations. We speculate that this effect may contribute to the taxonomic prevalence of sexual reproduction among higher organisms. In addition to sexual recombination, the problem of genetic linkage for behaviorally complex organisms may be mitigated by entrusting evolution with the task of finding appropriate modular architectures and learning with the task of finding the appropriate connection weights for these architectures

    Objects, spatial compatibility, and affordances: A connectionist study

    Get PDF
    In two Artificial Life simulations we evolved artificial organisms possessing a visual and a motor system, and whose nervous system was simulated with a neural network. Each organism could see four objects, either upright or reversed, with a left or a right handle. In Task 1 they learned to reach the object handle independently of the handle\u27s position. In Task 2 they learned to reach one of two buttons located below the handle either to decide either where the handle was (Simulation 1) or whether the object was upright or reversed (Simulation 2). Task 1 simulated real life experience, Task 2 replicated either a classic spatial compatibility task (Simulation 1) or an experiment by Tucker & Ellis (1998) (Simulation 2). In both simulations learning occurred earlier in the Compatible condition, when the button to reach and the handle were on the same side, than in the Incompatible condition

    Thermo-economic assessment of a olive pomace gasifier for cogeneration applications

    Get PDF
    A thermo-economic analysis of a combined heat and power (CHP) plant fed by syngas produced through the gasification of dry olive pomace is presented. The plant is composed by a 800 kWtdowndraft gasifier, a gas clean-up system, a 200 kWemicroturbine (MGT) and a heat recovery system to cogenerate hot water. Surplus heat is used to dry olive pomace from 50% to 17% wb moisture content. The plant is modeled in ASPEN Plus. Real data from experimental tests are used to calibrate the gasifier model, while the technical specification and performance of the CHP plant are collected from commercial plants in operation and data from manufacturers. Mass and energy balances are reported throughout the paper. The thermodynamic simulation of the biomass gasifier coupled to the MGT, the thermal and electrical conversion efficiency and temperature of cogenerated heat available are also presented. A thermo-economic assessment is then proposed, to investigate the economic profitability of this small scale CHP plant in the Italian energy policy scenario and considering the subsidies available for renewable electricity in the form of feed-in tariffs. For this purpose, the case study of base load CHP plant operation and heat supplied to different typologies of energy end user is assumed. The results allow quantifying the most influencing economic and technical factors that affect the performance and profitability of such investment and the bottlenecks that should be faced to facilitate a broader implementation of such CHP schemes for on site generation

    The role of the rehabilitation in subjects with Progressive Supranuclear Palsy: a narrative review

    Get PDF
    Progressive Supranuclear Palsy (PSP) is a progressive neurodegenerative disorder due to the deposition of abnormal proteins in neurons of the basal ganglia that limit motor ability producing disability and reduced quality of life. So far, no pharmacologic therapy has been developed and the treatment remains symptomatic. The aim of the present study was to investigate systematically literature, and to determine the types and effects of rehabilitative interventions. A search of all studies was conducted in MEDLINE/PubMed, the Cochrane Central Register of Controlled Trials, CINAHL and EMBASE. Twelve studies were individuated including 6 case reports, 3 case series, one case control, one quasi-RT crossover study and one RCT, with 88 patients investigated overall. Rehabilitative interventions varied in type, number, frequency and duration of sessions. The most commonly used clinical measures were Progressive Supranuclear Palsy-Rating Scale (PSP-RS) and Unified Parkinson's Disease Rating Scale (UPDRS). Physical exercises were the main rehabilitative strategy but were associated with other interventions and rehabilitative devices, in particular treadmill and robot-assisted gait training. All studies showed an improvement of balance and gait impairment with a reduction of falls after rehabilitation treatment. Due to poor methodological quality and the variability of rehabilitative approach with different and variable strategies, there was no evidence of the effectiveness of a specific rehabilitation intervention in PSP. Despite this finding, rehabilitation might improve balance and gait, thereby reducing falls in PSP subjects

    Benign intracranial hypertension associated to blood coagulation derangements

    Get PDF
    Benign Intracranial Hypertension (BIH) may be caused, at least in part, by intracranial sinus thrombosis. Thrombosis is normally due to derangements in blood coagulation cascade which may predispose to abnormal clotting activation or deficiency in natural inhibitors' control. The aim of the study is to examine the strength of the association between risk factors for thrombosis and BIH

    Soft Tissue Contour Impression with Analogic or Digital Work Flow: A Case Report

    Get PDF
    Transferring precise information to the dental laboratory is one of the key factors to achieving clinical success. The aim of the present study was to describe classical and digital work-flows used to rehabilitate an implant with a convergent collar in the aesthetic zone following the BOPT (biologically oriented preparation technique) approach and to report the three years follow-up outcomes of two patients rehabilitated following such procedures

    A network analysis on cloud gaming: Stadia, GeForce Now and PSNow

    Get PDF
    Cloud gaming is a new class of services that promises to revolutionize the videogame market. It allows the user to play a videogame with basic equipment while using a remote server for the actual execution. The multimedia content is streamed through the network from the server to the user. This service requires low latency and a large bandwidth to work properly with low response time and high-definition video. Three of the leading tech companies, (Google, Sony and NVIDIA) entered this market with their own products, and others, like Microsoft and Amazon, are planning to launch their own platforms in the near future. However, these companies released so far little information about their cloud gaming operation and how they utilize the network. In this work, we study these new cloud gaming services from the network point of view. We collect more than 200 packet traces under different application settings and network conditions for 3 cloud gaming services, namely Stadia from Google, GeForce Now from NVIDIA and PS Now from Sony. We analyze the employed protocols and the workload they impose on the network. We find that GeForce Now and Stadia use the RTP protocol to stream the multimedia content, with the latter relying on the standard WebRTC APIs. They result in bandwidth-hungry and consume up to 45 Mbit/s, depending on the network and video quality. PS Now instead uses only undocumented protocols and never exceeds 13 Mbit/s

    Zespół padaczkowy z drgawkami połowiczymi i porażeniem połowiczym. Wyniki badania za pomocą rezonansu magnetycznego u trzyletniego chłopca

    Get PDF
    The term ‘hemiconvulsion-hemiplegia-epilepsy syndrome’ (HHE) was first used by Gastaut et al. to describe the sequential combination of unilateral or predominandy unilateral clonic seizures (hemiconvulsion), occurring during the first 2 years of life, immediately followed by an ipsilateral flaccid hemiplegia lasting 7 or more days. In the following phase partial epileptic seizures occur. We report a case of HHE syndrome in a 3-year-old boy with partial seizures (hemiconvulsion lasting 15–30 minutes) followed by left hemiplegia and hyporeflexia. Magnetic resonance imaging showed diffuse and high signal hyperintensity of the whole right cerebral hemisphere. Diffusion-weighted images showed a reduction of the apparent diffusion coefficient in the subcortical region. Magnetic resonance arteriography showed a narrow flow signal in the distal territory of the right middle cerebral artery. The authors emphasize the importance of neuroradiological findings in early diagnosis and in the follow-up of HHE syndrome.Określenia zespół padaczkowy z drgawkami połowiczymi i z porażeniem połowiczym” (hemiconvulsion-hemiplegia epilepsy – HHE) użyli po raz pierwszy Gastaut i wsp., aby opisać połączenie jednostronnych lub głównie jednostronnych drgawek klonicznych, pojawiających się w pierwszych dwóch latach życia, po których następuje tożstronne wiotkie porażenie połowicze utrzymujące się przez co najmniej tydzień. Następnie występują napady padaczkowe częściowe. W artykule przedstawiono przypadek zespołu HHE u trzyletniego chłopca z napadami częściowymi (drgawki połowicze trwające 15–30 minut), po których nastąpiło lewostronne porażenie połowicze z osłabionymi odruchami głębokimi. W badaniu za pomocą rezonansu magnetycznego uwidoczniono rozlane zmiany hiperintensywne w całej prawej półkuli mózgu. W obrazowaniu dyfuzji stwierdzono zmniejszenie współczynnika dyfuzji w obszarach podkorowych. W arteriografii rezonansu magnetycznego uwidoczniono wąski sygnał przepływu w dystalnych gałęziach prawej tętnicy środkowej mózgu. Autorzy podkreślają znaczenie wyników badań obrazowych układu nerwowego we wczesnym rozpoznaniu i obserwacji chorych na HHE

    Intranasal rapamycin ameliorates Alzheimer-like cognitive decline in a mouse model of Down syndrome

    Get PDF
    Background: Down syndrome (DS) individuals, by the age of 40s, are at increased risk to develop Alzheimer-like dementia, with deposition in brain of senile plaques and neurofibrillary tangles. Our laboratory recently demonstrated the disturbance of PI3K/AKT/mTOR axis in DS brain, prior and after the development of Alzheimer Disease (AD). The aberrant modulation of the mTOR signalling in DS and AD age-related cognitive decline affects crucial neuronal pathways, including insulin signaling and autophagy, involved in pathology onset and progression. Within this context, the therapeutic use of mTOR-inhibitors may prevent/attenuate the neurodegenerative phenomena. By our work we aimed to rescue mTOR signalling in DS mice by a novel rapamycin intranasal administration protocol (InRapa) that maximizes brain delivery and reduce systemic side effects. Methods: Ts65Dn mice were administered with InRapa for 12 weeks, starting at 6 months of age demonstrating, at the end of the treatment by radial arms maze and novel object recognition testing, rescued cognition. Results: The analysis of mTOR signalling, after InRapa, demonstrated in Ts65Dn mice hippocampus the inhibition of mTOR (reduced to physiological levels), which led, through the rescue of autophagy and insulin signalling, to reduced APP levels, APP processing and APP metabolites production, as well as, to reduced tau hyperphosphorylation. In addition, a reduction of oxidative stress markers was also observed. Discussion: These findings demonstrate that chronic InRapa administration is able to exert a neuroprotective effect on Ts65Dn hippocampus by reducing AD pathological hallmarks and by restoring protein homeostasis, thus ultimately resulting in improved cognition. Results are discussed in term of a potential novel targeted therapeutic approach to reduce cognitive decline and AD-like neuropathology in DS individuals
    corecore