5,705 research outputs found

    From car to bike. Marketing and dialogue as a driver of change

    Get PDF
    The Paris Climate Agreement has sent a key message to the international community regarding the need to increase efforts to move towards a low-carbon economy and help slow climate change, while underpinning global long-term economic growth and sustainable development. COP 21 recognizes the social, economic and environmental value of voluntary mitigation actions and their co-benefits for adaptation, health and sustainable development. In this framework, the PTP Cycle project, running from 2013 to 2016 and funded by the European Commission through the Intelligent Energy Europe program, introduces a non-market approach through voluntary participation in the adoption of sustainable transport modes such as cycling, based on marketing to potential customers through Personalized Travel Plans. The medium-sized city of Burgos (Spain) and the cities of Ljubljana, Riga, Antwerp and London (boroughs of Haringey and Greenwich) developed a new policy instrument (Personalized Travel Plans) in order to increase bike patronage. Beyond potential savings of CO2, the results show that PTP as a form of Active Mobility Consultancy is a suitable instrument to influence modal shift to public transport, walking and cycling, and to address the challenges of climate change, while fostering sustainable transportation by changing mobility behaviour. These results, matching with the state-of-the-art of studies and pilot applications in other countries, allows deriving differentiated results for medium-size and large urban areas

    Comparison of nitrification inhibitors to restrict nitrate leaching in a maize crop irrigated under mediterranean conditions

    Get PDF
    The aim of this paper was to compare dicyandiamide (DCD) and 3,4 dimethylpyrazole phosphate (DMPP) as inhibitors of ammonium oxidation and nitrate leaching after applying fertilizer to a maize (Zea mays L.) crop grown under Mediterranean conditions. The effects of nitrification inhibitors were also compared to those of N fertilization without inhibitors and with split N application. In plots fertilized with ammonium sulphate nitrate (ASN), either DCD or DMPP lengthened ammonium presence in soil and produced lower soil NO3- concentrations (30% lower than in plots with no inhibitor). The use of DCD or DMPP achieved significant reductions in nitrate leaching. DCD showed excellent properties for controlling nitrate leaching, taking into account the fact that grain yield and N accumulated by plant were similar for the ASN-DCD and ASN treatments applied at the same N doses. The split N treatment did not offer any advantages in terms of leached nitrate, either with the use of single ammonium sulphate nitrate (ASN) or with single application of nitrification inhibitors. The nitrification inhibitors did not increase the yield but did not reduce it either. The drainage rate was the most important component of nitrate leaching. The low drainage values of the first year resulted in a sharp decline of nitrate leaching. However, the experiment of the second year, showed clear differences in nitrate leaching between treatments due to the greater drainage

    A New Approach to Analysis the Security of Compensated Measuring PUFs

    Get PDF
    In this paper we perform an entropy analysis and probability distribution analysis over simulated PUFs operating under a compensated measuring digitization scheme. The behavior of the PUFs have been simulated by generating a set of pseudorandom numbers uniformly distributed, which simulate the measured parameters, using the definition of the so called "topology of the PUF", i.e. the way in which different parameter measurements are compared to obtain a digital binary output. At this respect, we prove the existence of a shortcoming in the most commonly used PUF topologies. as well as provide some guidelines to overcome it

    Introduction to Physically Unclonable Fuctions: Properties and Applications

    Get PDF
    During the last years, Physically Unclonable Functions (PUFs) have become a very important research area in the field of hardware security due to their capability of generating volatile secret keys as well as providing a low-cost authentication. In this paper, an introduction to Physically Unclonable Functions is given, including their definition, properties and applications. Finally, as an example of how to design a PUF, the general structure of a ring oscillator PUF is presented

    Proposal and Analysis of a Novel Class of PUFs Based on Galois Ring Oscillators

    Get PDF
    In this article, the possibility of using Galois ring oscillators to construct physically unclonable functions (PUFs) has been studied. The idea is to use novel PUF architectures, similar as the ring oscillator PUFs that, instead of comparing frequencies, compare the statistical bias of pairs of oscillators implemented in different locations. To study the viability of these systems, three different Galois oscillators have been implemented in several locations in several FPGAs and we have studied the main properties of their bias: repeatability, variability with the location, variability with the FPGA and spatial autocorrelation. Based on this study, we have determined that the bias of these oscillators meet the requirements that are needed to be used to construct a PUF. Finally, a PUF based on comparing the bias of neighboring 7-LUT Galois ring oscillators have been implemented and analyzed. The experimental results show that this PUF generates uniform responses that are highly reproducible and unique, making this PUF suitable for being used in identification applications

    Tgfβ2 and 3 are coexpressed with their extracellular regulator Ltbp1 in the early limb bud and modulate mesodermal outgrowth and BMP signaling in chicken embryos

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Transforming growth factor β proteins (Tgfβs) are secreted cytokines with well-defined functions in the differentiation of the musculoskeletal system of the developing limb. Here we have studied in chicken embryos, whether these cytokines are implicated in the development of the embryonic limb bud at stages preceding tissue differentiation.</p> <p>Results</p> <p>Immunohistochemical detection of phosphorylated Smad2 and Smad3 indicates that signaling by this pathway is active in the undifferentiated mesoderm and AER. Gene expression analysis shows that transcripts of <it>tgfβ2 </it>and <it>tgfβ3 </it>but not <it>tgfβ1 </it>are abundant in the growing undifferentiated limb mesoderm. Transcripts of <it>tgfβ2 </it>are also found in the AER, which is the signaling center responsible for limb outgrowth. Furthermore, we show that Latent Tgfβ Binding protein 1 (LTBP1), which is a key extracellular modulator of Tgfβ ligand bioavailability, is coexpressed with <it>Tgfβs </it>in the early limb bud. Administration of exogenous Tgfβs to limb buds growing in explant cultures provides evidence of these cytokines playing a role in the regulation of mesodermal limb proliferation. In addition, analysis of gene regulation in these experiments revealed that Tgfβ signaling has no effect on the expression of master genes of musculoskeletal tissue differentiation but negatively regulates the expression of the BMP-antagonist Gremlin.</p> <p>Conclusion</p> <p>We propose the occurrence of an interplay between Tgfβ and BMP signaling functionally associated with the regulation of early limb outgrowth by modulating limb mesenchymal cell proliferation.</p

    A 1 Gbps Chaos-Based Stream Cipher Implemented in 0.18 m CMOS Technology

    Get PDF
    In this work, a novel chaos-based stream cipher based on a skew tent map is proposed and implemented in a 0.18 µm CMOS (Complementary Metal-Oxide-Semiconductor) technology. The proposed ciphering algorithm uses a linear feedback shift register that perturbs the orbits generated by the skew tent map after each iteration. This way, the randomness of the generated sequences is considerably improved. The implemented stream cipher was capable of achieving encryption speeds of 1 Gbps by using an approximate area of ~20,000 2-NAND equivalent gates, with a power consumption of 24.1 mW. To test the security of the proposed cipher, the generated keystreams were subjected to National Institute of Standards and Technology (NIST) randomness tests, proving that they were undistinguishable from truly random sequences. Finally, other security aspects such as the key sensitivity, key space size, and security against reconstruction attacks were studied, proving that the stream cipher is secure

    Protein-energy wasting syndrome in advanced chronic kidney disease: Prevalence and specific clinical characteristics

    Full text link
    Introduction: Protein-energy wasting (PEW) is associated with increased mortality and differs depending on the chronic kidney disease (CKD) stage and the dialysis technique. The prevalence in non-dialysis patients is understudied and ranges from 0 to 40.8%. Objective: To evaluate the nutritional status of a group of Spanish advanced CKD patients by PEW criteria and subjective global assessment (SGA). Patients and methods: Cross-sectional study of 186 patients (101 men) with a mean age of 66.1 ± 16 years. The nutritional assessment consisted of: SGA, PEW criteria, 3-day dietary records, anthropometric parameters and bioelectrical impedance vector analysis. Results: The prevalence of PEW was 30.1%, with significant differences between men and women (22.8 vs. 33.8%, p &lt; 0.005), while 27.9% of SGA values were within the range of malnutrition. No differences were found between the 2 methods. Men had higher proteinuria, percentage of muscle mass and nutrient intake. Women had higher levels of total cholesterol, HDL and a higher body fat percentage. The characteristics of patients with PEW were low albumin levels and a low total lymphocyte count, high proteinuria, low fat and muscle mass and a high Na/K ratio. The multivariate analysis found PEW to be associated with: proteinuria (OR: 1.257; 95% CI: 1.084–1.457, p = 0.002), percentage of fat intake (OR: 0.903; 95% CI: 0.893–0.983, p = 0.008), total lymphocyte count (OR: 0.999; 95% CI: 0.998–0.999, p = 0.001) and cell mass index (OR: 0.995; 95% CI: 0.992–0.998). Conclusion: Malnutrition was identified in Spanish advanced CKD patients measured by different tools. We consider it appropriate to adapt new diagnostic elements to PEW criteria.Introducción: El desgaste proteico energético (DPE) se asocia a mayor mortalidad y difieredependiendo del estadio de la enfermedad renal y de la técnica de diálisis. Su prevalenciaen pacientes sin diálisis se encuentra poco estudiada y oscila entre el 0 y el 40,8%.Objetivo: Evaluar el estado nutricional según criterios de DPE y por valoración global subje-tiva (VGS) de un colectivo de pacientes espa˜noles con enfermedad renal crónica avanzada(ERCA).Pacientes y métodos: Estudio transversal de 186 pacientes (101 hombres) con edad media de66,1 ± 16 a˜nos. Se realizó evaluación nutricional mediante: VGS, criterios de DPE, registrodietético de 3 días, parámetros antropométricos y bioimpedancia vectorial.Resultados: Un 30,1% presentaba DPE, con diferencias significativas entre hombres y mujeres(22,8 vs. 33,8%; p < 0,005) y un 27,9% tenía valores de VGS en rangos de desnutrición. Sindiferencia entre los 2 métodos estudiados. Los hombres presentaron mayores niveles deproteinuria, porcentaje de masa muscular e ingesta de nutrientes. Las mujeres tuvieronmayores niveles de colesterol total, HDL y porcentaje de masa grasa. Las característicasde los pacientes con DPE fueron: bajos valores de albúmina y recuento total de linfocitos,elevada proteinuria, baja masa grasa, baja masa muscular y cociente Na/K elevado.El análisis multivariante mostró asociación de DPE con proteinuria (OR: 1,257; IC 95%:1,084-1,457; p = 0,002), porcentaje de ingesta lipídica (OR: 0,903; IC 95%: 0,893-0,983; p = 0,008),recuento total de linfocitos (OR: 0,999; IC 95%: 0,998-0,999; p = 0,001) y el índice de masacelular (OR: 0,995; IC 95%: 0,992-0,998)
    corecore