1,909 research outputs found
Feeding Stimulates Sphingosine-1-Phosphate Mobilization in Mouse Hypothalamus.
Previous studies have shown that the sphingolipid-derived mediator sphingosine-1-phosphate (S1P) reduces food intake by activating G protein-coupled S1P receptor-1 (S1PR1) in the hypothalamus. Here, we examined whether feeding regulates hypothalamic mobilization of S1P and other sphingolipid-derived messengers. We prepared lipid extracts from the hypothalamus of C57Bl6/J male mice subjected to one of four conditions: free feeding, 12 h fasting, and 1 h or 6 h refeeding. Liquid chromatography/tandem mass spectrometry was used to quantify various sphingolipid species, including sphinganine (SA), sphingosine (SO), and their bioactive derivatives SA-1-phosphate (SA1P) and S1P. In parallel experiments, transcription of S1PR1 (encoded in mice by the S1pr1 gene) and of key genes of sphingolipid metabolism (Sptlc2, Lass1, Sphk1, Sphk2) was measured by RT-PCR. Feeding increased levels of S1P (in pmol-mg-1 of wet tissue) and SA1P. This response was accompanied by parallel changes in SA and dihydroceramide (d18:0/18:0), and was partially (SA1P) or completely (S1P) reversed by fasting. No such effects were observed with other sphingolipid species targeted by our analysis. Feeding also increased transcription of Sptlc2, Lass1, Sphk2, and S1pr1. Feeding stimulates mobilization of endogenous S1PR1 agonists S1P and SA1P in mouse hypothalamus, via a mechanism that involves transcriptional up-regulation of de novo sphingolipid biosynthesis. The results support a role for sphingolipid-mediated signaling in the central control of energy balance
High resolution satellite imagery orientation accuracy assessment by leave-one-out method: accuracy index selection and accuracy uncertainty
The Leave-one-out cross-validation (LOOCV) was recently applied to the evaluation of High Resolution Satellite Imagery orientation accuracy and it has proven to be an effective method alternative with respect to the most common Hold-out-validation (HOV), in which ground points are split into two sets, Ground Control Points used for the orientation model estimation and Check Points used for the model accuracy assessment.
On the contrary, the LOOCV applied to HRSI implies the iterative application of the orientationmodel using all the known ground points as GCPs except one, different in each iteration, used as a CP. In every iteration the residual between imagery derived coordinates with respect to CP coordinates (prediction error of the model on CP coordinates) is calculated; the overall spatial accuracy achievable from the oriented image may be estimated by computing the usual RMSE or, better, a robust accuracy index like the mAD (median Absolute Deviation) of prediction errors on all the iterations.
In this way it is possible to overcome some drawbacks of the HOV: LOOCVis a reliable and robustmethod, not dependent on a particular set of CPs and on possible outliers, and it allows us to use each known ground point both as a GCP and as a CP, capitalising all the available ground information. This is a crucial problem in current situations, when the number of GCPs to be collected must be reduced as much as possible for obvious budget problems. The fundamentalmatter to deal with was to assess howwell LOOCVindexes (mADand RMSE) are able to represent the overall accuracy, that is howmuch they are stable and close to the corresponding HOV RMSE assumed as reference. Anyway, in the first tests the indexes comparison was performed in a qualitative way, neglecting their uncertainty. In this work the analysis has been refined on the basis of Monte Carlo simulations, starting from the actual accuracy of ground points and images coordinates, estimating the desired accuracy indexes (e.g. mAD and RMSE) in several trials, computing their uncertainty (standard deviation) and accounting for them in the comparison.
Tests were performed on a QuickBird Basic image implementing an ad hoc procedure within the SISAR software developed by the Geodesy and Geomatics Team at the Sapienza University of Rome. The LOOCV method with accuracy evaluated by mAD seemed promising and useful for practical case
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A protective role for N-acylphosphatidylethanolamine phospholipase D in 6-OHDA-induced neurodegeneration.
N-acylphosphatidylethanolamine phospholipase D (NAPE-PLD) catalyzes the cleavage of membrane NAPEs into bioactive fatty-acid ethanolamides (FAEs). Along with this precursor role, NAPEs might also serve autonomous signaling functions. Here, we report that injections of 6-hydroxydopamine (6-OHDA) into the mouse striatum cause a local increase in NAPE and FAE levels, which precedes neuronal cell death. NAPE, but not FAE, accumulation is enhanced in mice lacking NAPE-PLD, which display a substantial reduction in 6-OHDA-induced neurotoxicity, as shown by increased survival of substantia nigra dopamine neurons, integrity of striatal dopaminergic fibers, and striatal dopamine metabolite content. Reduced damage is accompanied by attenuation of the motor response evoked by apomorphine. Furthermore, NAPE-PLD silencing protects cathecolamine-producing SH-SY5Y cells from 6-OHDA-induced reactive oxygen species formation, caspase-3 activation and death. Mechanistic studies in mice suggest the existence of multiple molecular contributors to the neuroprotective effects of NAPE-PLD deletion, including suppression of Rac1 activity and attenuated transcription of several genes (Cadps, Casp9, Egln1, Kcnj6, Spen, and Uchl1) implicated in dopamine neuron survival and/or Parkinson's disease. The findings point to a previously unrecognized role for NAPE-PLD in the regulation of dopamine neuron function, which may be linked to the control of NAPE homeostasis in membranes
Application of the analytical hierarchy process to evaluate consumer acceptance and preferences for omega-3 enriched eggs
Purpose: The purpose of this paper is to analyse the appropriateness of the analytical hierarchy process (AHP) to measure consumers’ acceptance and preference for eggs enriched with omega-3 (n-3) fatty acids as a health claim and to compare its results with the traditional nine-point hedonic scale. Design/methodology/approach: The AHP was used as a multi-criteria decision analysis. Data were obtained from a face-to-face questionnaire completed by 122 consumers in a controlled environment in Cataluña (Spain). Findings: Results showed the capacity of the AHP to analyse consumers’ acceptance and preferences. An agreement between the AHP and the nine-point scale was found showing that n-3 enriched eggs had lower flavour acceptance, conventional eggs had higher yolk colour acceptance, and conventional and the free-range eggs had similar and higher odour acceptance than the other egg types. The most important attributes that determine preferences for egg purchase were the type and the egg price followed by the origin and the egg size. Research limitations/implications: The AHP approach seems to be a reliable tool to evaluate consumers’ hedonic preferences. However, further testing on other food products with larger sample size is needed. Originality/value: The AHP methodology has been widely used in many fields in the last decades, but to the knowledge, not in the sensory field. In the Spanish market, studies that analyse consumers’ preferences and acceptance of eggs are scarce, and new insights are needed particularly regarding n-3 enriched eggs.Postprint (author's final draft
Role of endocannabinoids in regulating drug dependence
This review will discuss the latest knowledge of how the endocannabinoid system might be involved in treating addiction to the most common illicit drugs. Experimental models are providing increasing evidence for the pharmacological management of endocannabinoid signaling not only to block the direct reinforcing effects of cannabis, opioids, nicotine and ethanol, but also for preventing relapse to the various drugs of abuse, including opioids, cocaine, nicotine, alcohol and metamphetamine. Preclinical and clinical studies suggest that the endocannabinoid system can be manipulated by the CBI receptor antagonist SR141716A, that might constitute a new generation of compounds for treating addiction across different classes of abused drugs
Testing goGPS low-cost RTK positioning with a web-based track log management system
Location-based online collaborative platforms are proving to be an effective and widely adopted solution for geospatial data collection, update and sharing. Popular collaborative projects like OpenStreetMap, Wikimapia and other services that collect and publish user-generated geographic contents have been fostered by the increasing availability of location-aware palmtop devices. These instruments include GPS-enabled mobile phones and low-cost GPS receivers, which are employed for quick field surveys at both professional and non-professional levels. Nevertheless, data collected with such devices are often not accurate enough to avoid heavy user intervention before using or sharing them. Providing tools for collecting and sharing accuracy-enhanced positioning data to a wide and diverse user base requires to integrate modern web technologies and online services with advanced satellite positioning techniques. A web-based prototype system for enhancing GPS tracks quality and managing track logs and points of interest (POI), originally developed using standard GPS devices, was tested by using goGPS software to apply kinematic relative positioning (RTK) with low-cost single-frequency receivers. The workflow consists of acquiring raw GPS measurements from the user receiver and from a network of permanent GPS stations, processing them by RTK positioning within goGPS Kalman filter algorithm, sending the accurate positioning data to the web-based system, performing further quality enhancements if needed, logging the data and displaying them. The whole system can work either in real-time or post-processing, the latter providing a solution to collect and publish enhanced location data without necessarily requiring mobile Internet connection on the field. Tests were performed in open areas and variously dense urban environments, comparing different indices for quality-based filtering. Results are promising and suggest that the integration of web technologies with advanced geodetic techniques applied to low-cost instruments can be an effective solution to collect, update and share accurate location data on collaborative platforms
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Elevated plasma ceramide levels in post-menopausal women: a cross-sectional study.
Circulating ceramide levels are abnormally elevated in age-dependent pathologies such as cardiovascular diseases, obesity and Alzheimer's disease. Nevertheless, the potential impact of age on plasma ceramide levels has not yet been systematically examined. In the present study, we quantified a focused panel of plasma ceramides and dihydroceramides in a cohort of 164 subjects (84 women) 19 to 80 years of age. After adjusting for potential confounders, multivariable linear regression analysis revealed a positive association between age and ceramide (d18:1/24:0) (β (SE) = 5.67 (2.38); p = .0198) and ceramide (d18:1/24:1) (β (SE) = 2.88 (.61); p < .0001) in women, and between age and ceramide (d18:1/24:1) in men (β (SE) = 1.86 (.77); p = .0179). In women of all ages, but not men, plasma ceramide (d18:1/24:1) was negatively correlated with plasma estradiol (r = -0.294; p = .007). Finally, in vitro experiments in human cancer cells expressing estrogen receptors showed that incubation with estradiol (10 nM, 24 h) significantly decreased ceramide accumulation. Together, the results suggest that aging is associated with an increase in circulating ceramide levels, which in post-menopausal women is at least partially associated with lower estradiol levels
El complejo megalítico de Monte Baranta en Cerdeña: ¿centro de peregrinaje en la Edad del Bronce Antiguo?
The imposing megalithic complex located on the Monte Baranta plateau, near the town of Olmedo in North-west Sardinia is one of the best preserved monuments of the pre-nuragic period, and pertains to the cultural horizon called Monte Claro (2500-2200 BC circa). The complex is particularly interesting in the context of late-Neolithic architecture since it was abandoned already during the Monte Claro phase, and only sporadic frequentation is documented afterwards. The site is usually interpreted as a fortified stronghold but this interpretation has many drawbacks. As a consequence, we have subjected the site to a new survey with the specific aim of gaining a better understanding of its function. Our survey, based on classical topographic observations combined with GPS measurements has led to a new reading of the megalithic complex: topographical and archaeo-astronomical data indeed clearly point to a radically new interpretation of this site as a sacred place, probably a pilgrimage centre.El imponente complejo megalítico situado en la meseta del Monte Baranta, cerca del pueblo de Olmedo en el Noroeste de Cerdeña, es uno de los monumentos mejor preservados de la época pre-nurágica y pertenece al horizonte cultural Monte Claro (c. 2500-2200 a.C.). El interés del complejo, en el contexto de la arquitectura del Neolítico Final, se debe a que fue abandonado durante la propia fase Monte Claro y solo se ha documentado una ocupación de tipo esporádico posteriormente. El yacimiento se ha interpretado en general como un baluarte fortificado, pero esta interpretación presenta muchos problemas, y por ello hemos realizado una nueva prospección en el sitio para discernir mejor su función. Siguiendo los métodos clásicos topográficos combinados con mediciones de GPS, hemos podido realizar una nueva lectura del complejo, del cual los datos arqueoastronómicos y topográficos apuntan claramente a una interpretación completamente nueva como un lugar sagrado, probablemente un centro de peregrinación
Key performance indicators of ‘good practices’ of energy efficiency in industry: application to real cases in Italy and in the European Union
With the publication of the Energy Efficiency Directive (EED) in 2012, energy savings in the Industry processes have gained more and more importance in the European Union (EU). Industry (with building and transport) is one of the three main sectors where Energy consumption and efficiency play a fundamental role, to accomplish the EU energy objectives. Many countries in EU have already adopted schemes and mechanisms to implement the Directive: however deep differences of approaches still remain among the Member States (MSs), especially with respect to the identification of the real benefits of measures and to the assessment of their efficiency and sustainability. As a consequence, a huge amount of the efficiency potential still remains untapped. This paper proposes some criteria for the evaluation of the applied Energy Efficiency measures, leading to the identification of Good Practices of Energy Efficiency. These criteria are taken from the ‘real world’ of industry, and are susceptible to be replicated in other contexts (e.g. different sectors or other countries). The proposed criteria have been developed in the EU H2020 project EU MERCI (nr 693845) and through a national research (part of the ‘Ricerca di Sistema’ national funding system) both coordinated by RSE. The starting point is the harmonization of data sets related to projects developed in different EU countries within local efficiency implementation schemes. The second step is the definition of Key Performance Indicators (KPIs) reflecting the impact of measures against Energy, Environment and Economic aspects. The last step is the extraction of efficiency ‘Good Practices’ ranked according to the identified KPIs and other factors, including social elements. The real added value of this approach is that it is full based on tangibly implemented projects, in opposition to similar attempts, essentially theoretical. Ultimately, it offers a key of assessment of the effectiveness of efficiency measures implementing local and EU policies
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