87 resultados para 310-M0005C
Resumo:
There is general agreement in the scientific community that entrepreneurship plays a central role in the growth and development of an economy in rapidly changing environments (Acs & Virgill 2010). In particular, when business activities are regarded as a vehicle for sustainable growth at large, that goes beyond mere economic returns of singular entities, encompassing also social problems and heavily relying on collaborative actions, then we more precisely fall into the domain of ‘social entrepreneurship’(Robinson et al. 2009). In the entrepreneurship literature, prior studies demonstrated the role of intentionality as the best predictor of planned behavior (Ajzen 1991), and assumed that the intention to start a business derives from the perception of desirability and feasibility and from a propensity to act upon an opportunity (Fishbein & Ajzen 1975). Recognizing that starting a business is an intentional act (Krueger et al. 2000) and entrepreneurship is a planned behaviour (Katz & Gartner 1988), models of entrepreneurial intentions have substantial implications for intentionality research in entrepreneurship. The purpose of this paper is to explore the emerging practice of social entrepreneurship by comparing the determinants of entrepreneurial intention in general versus those leading to startups with a social mission. Social entrepreneurial intentions clearly merit to be investigated given that the opportunity identification process is an intentional process not only typical of for profit start-ups, and yet there is a lack of research examining opportunity recognition in social entrepreneurship (Haugh 2005). The key argument is that intentionality in both traditional and social entrepreneurs during the decision-making process of new venture creation is influenced by an individual's perceptions toward opportunities (Fishbein & Ajzen 1975). Besides opportunity recognition, at least two other aspects can substantially influence intentionality: human and social capital (Davidsson, 2003). This paper is set to establish if and to what extent the social intentions of potential entrepreneurs, at the cognitive level, are influenced by opportunities recognition, human capital, and social capital. By applying established theoretical constructs, the paper draws comparisons between ‘for-profit’ and ‘social’ intentionality using two samples of students enrolled in Economy and Business Administration at the University G. d’Annunzio in Pescara, Italy. A questionnaire was submitted to 310 potential entrepreneurs to test the robustness of the model. The collected data were used to measure the theoretical constructs of the paper. Reliability of the multi-item scale for each dimension was measured using Cronbach alpha, and for all the dimensions measures of reliability are above 0.70. We empirically tested the model using structural equation modeling with AMOS. The results allow us to empirically contribute to the argument regarding the influence of human and social cognitive capital on social and non-social entrepreneurial intentions. Moreover, we highlight the importance for further researchers to look deeper into the determinants of traditional and social entrepreneurial intention so that governments can one day define better polices and regulations that promote sustainable businesses with a social imprint, rather than inhibit their formation and growth.
Resumo:
The main cis-acting control regions for replication of the single-stranded DNA genome of maize streak virus (MSV) are believed to reside within an approximately 310 nt long intergenic region (LIR). However, neither the minimum LIR sequence required nor the sequence determinants of replication specificity have been determined experimentally. There are iterated sequences, or iterons, both within the conserved inverted-repeat sequences with the potential to form a stem-loop structure at the origin of virion-strand replication, and upstream of the rep gene TATA box (the rep-proximal iteron or RPI). Based on experimental analyses of similar iterons in viruses from other geminivirus genera and their proximity to known Rep-binding sites in the distantly related mastrevirus wheat dwarf virus, it has been hypothesized that the iterons may be Rep-binding and/or -recognition sequences. Here, a series of LIR deletion mutants was used to define the upper bounds of the LIR sequence required for replication. After identifying MSV strains and distinct mastreviruses with incompatible replication-specificity determinants (RSDs), LIR chimaeras were used to map the primary MSV RSD to a 67 nt sequence containing the RPI. Although the results generally support the prevailing hypothesis that MSV iterons are functional analogues of those found in other geminivirus genera, it is demonstrated that neither the inverted-repeat nor RPI sequences are absolute determinants of replication specificity. Moreover, widely divergent mastreviruses can trans-replicate one another. These results also suggest that sequences in the 67 nt region surrounding the RPI interact in a sequence-specific manner with those of the inverted repeat.
Resumo:
We conducted an in-situ X-ray micro-computed tomography heating experiment at the Advanced Photon Source (USA) to dehydrate an unconfined 2.3 mm diameter cylinder of Volterra Gypsum. We used a purpose-built X-ray transparent furnace to heat the sample to 388 K for a total of 310 min to acquire a three-dimensional time-series tomography dataset comprising nine time steps. The voxel size of 2.2 μm3 proved sufficient to pinpoint reaction initiation and the organization of drainage architecture in space and time. We observed that dehydration commences across a narrow front, which propagates from the margins to the centre of the sample in more than four hours. The advance of this front can be fitted with a square-root function, implying that the initiation of the reaction in the sample can be described as a diffusion process. Novel parallelized computer codes allow quantifying the geometry of the porosity and the drainage architecture from the very large tomographic datasets (20483 voxels) in unprecedented detail. We determined position, volume, shape and orientation of each resolvable pore and tracked these properties over the duration of the experiment. We found that the pore-size distribution follows a power law. Pores tend to be anisotropic but rarely crack-shaped and have a preferred orientation, likely controlled by a pre-existing fabric in the sample. With on-going dehydration, pores coalesce into a single interconnected pore cluster that is connected to the surface of the sample cylinder and provides an effective drainage pathway. Our observations can be summarized in a model in which gypsum is stabilized by thermal expansion stresses and locally increased pore fluid pressures until the dehydration front approaches to within about 100 μm. Then, the internal stresses are released and dehydration happens efficiently, resulting in new pore space. Pressure release, the production of pores and the advance of the front are coupled in a feedback loop.
Resumo:
A PCR assay, using three primer pairs, was developed for the detection of Ureaplasma urealyticum, parvo biovar, mba types 1, 3, and 6, in cultured clinical specimens. The primer pairs were designed by using the polymorphic base positions within a 310- to 311-bp fragment of the 5* end and upstream control region of the mba gene. The specificity of the assay was confirmed with reference serovars 1, 3, 6, and 14 and by the amplified-fragment sizes (81 bp for mba 1, 262 bp for mba 3, and 193 bp for mba 6). A more sensitive nested PCR was also developed. This involved a first-step PCR, using the primers UMS-125 and UMA226, followed by the nested mba-type PCR described above. This nested PCR enabled the detection and typing of small numbers of U. urealyticum cells, including mixtures, directly in original clinical specimens. By using random amplified polymorphic DNA (RAPD) PCR with seven arbitrary primers, we were also able to differentiate the two biovars of U. urealyticum and to identify 13 RAPD-PCR subtypes. By applying these subtyping techniques to clinical samples collected from pregnant women, we established that (i) U. urealyticum is often a persistent colonizer of the lower genital tract from early midtrimester until the third trimester of pregnancy, (ii) mba type 6 was isolated significantly more often (P 5 0.048) from women who delivered preterm than from women who delivered at term, (iii) no particular ureaplasma subtype(s) was associated with placental infections and/or adverse pregnancy outcomes, and (iv) the ureaplasma subtypes most frequently isolated from women were the same subtypes most often isolated from infected placentas.
Resumo:
This article considers the implications for Queensland practitioners of the decision of the New South Wales Court of Appeal in Branson v Tucker [2012] NSWCA 310. That decision involved the question whether the court retained a jurisdiction to examine the reasonableness of costs charged by a barrister, who had entered a costs agreement with solicitors, in circumstances where where had been no application under the Legal Profession Act 2004 (NSW) for an assessment of the costs the subject of the bill and it was no longer possible for such an application to be made.
Resumo:
Reflection is an essential part of being an effective learner and working as a productive teacher. It enables the learner or teacher to deliberate about the factors that lead to successful learning and teaching for them and/or their students, in a particular place and for a specific purpose, so they can make reasoned and effective choices. This chapter introduces important frameworks that cover a century of thinking around reflection in education, and illustrates how preservice teachers can use these ideas across three phases. First, becoming a reflective learner as a university student to enhance learning and assessment outcomes; second, becoming a reflective teacher to improve classroom teaching and learning outcomes; and third, developing the reflective capacities of primary students so they can enhance their skills for lifelong learning.
Resumo:
The catalytic performance of Fe–Ni/PG (PG: palygorskite) catalysts pre-calcined and reduced at 500 ◦C for catalytic decomposition of tar derived through rice hull gasification was investigated. The materials were characterized by using X-ray diffraction, hydrogen temperature reduction, and transmission electron microscopy. The results showed that ferrites with spinel structure ((Fe, Ni)3O4) were formed during preparation of bimetallic systems during calcination and reduction of the precursors (Fe–Ni/PG catalysts) and NiO metal oxide particles were formed over Fe6–Ni9/PG catalyst. The obtained experimental data showed that Fe–Ni/PG catalysts had greater catalytic activity than natural PG. Tar removal using Fe6–Ni9/PG catalyst was as high as Fe10–Ni6/PG catalyst (99.5%). Fe6–Ni9/PG showed greater catalytic activity with greater H2 yield and showed stronger resistance to carbon deposition, attributed to the presence of NiO nanoparticles. Thus, the addition of nickel and iron oxides played an important role in catalytic cracking of rice hull biomass tar.
Resumo:
Pyrite and chalcopyrite mineral samples from Mangampet barite mine, Kadapa, Andhra Pradesh, India are used in the present study. XRD data indicate that the pyrite mineral has a face centered cubic lattice structure with lattice constant 5.4179 Å. Also it possesses an average particle size of 91.9 nm. An EPR study on the powdered samples confirms the presence of iron in pyrite and iron and Mn(II) in chalcopyrite. The optical absorption spectrum of chalcopyrite indicates presence of copper which is in a distorted octahedral environment. NIR results confirm the presence of water fundamentals and Raman spectrum reveals the presence of water and sulfate ions.
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This paper presents material and gas sensing properties of Pt/SnO2 nanowires/SiC metal oxide semiconductor devices towards hydrogen. The SnO2 nanowires were deposited onto the SiC substrates by vapour-liquid-solid growth mechanism. The material properties of the sensors were investigated using scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The current-voltage characteristics have been analysed. The effective change in the barrier height for 1% hydrogen was found to be 142.91 meV. The dynamic response of the sensors towards hydrogen at different temperatures has also been studied. At 530°C, voltage shift of 310 mV for 1% hydrogen was observed.
Resumo:
Pt/SnO2 nanowires/SiC based metal-oxidesemiconductor (MOS) devices were fabricated and tested for their gas sensitivity towards hydrogen. Tin oxide (SnO2) nanowires were grown on SiC substrates by the vapour liquid solid growth process. The material properties of the SnO2 nanowires such as its formation and dimensions were analyzed using scanning electron microscopy (SEM). The currentvoltage (I-V) characteristics at different hydrogen concentrations are presented. The effective change in the barrier height for 0.06 and 1% hydrogen were found to be 20.78 and 131.59 meV, respectively. A voltage shift of 310 mV at 530°C for 1% hydrogen was measured.
Resumo:
The influence of pH on interfacial energy and wettability distributed over the phospholipid bilayer surface were studied, and the importance of cartilage hydrophobicity (wettability) on the coefficient of friction (f) was established. It is argued that the wettability of cartilage signifi antly depends on the number of phospholipid bilayers acting as solid lubricant; the hypothesis was proven by conducting friction tests with normal and lipid- depleted cartilage samples. A lamellar-roller-bearing lubrication model was devised involving two mechanisms: (i) lamellar frictionless movement of bilayers, and (ii) roller-bearing lubrication mode through structured synovial fluid, which operates when lamellar spheres, liposomes and macromolecules act like a roller-bearing situated between two cartilage surfaces in effective biological lubrication.
Resumo:
The sidewall additions of diazomethane to (n, n), n = 3–10 armchair single-walled carbon nanotubes (SWCNTs) on two different orientations of C–C bonds have been studied using the ONIOM(B3LYP/6-31G(d):PM3) approach. The binding energies of SWCNTs complexes with CH2N2, CH2 and their transition-state structures were computed at the B3LYP/6-31G(d) level. The effects of diameters of armchair SWCNTs on their binding energies were studied. Relative reactivities of all the SWCNTs and their complexes based on their frontier orbital energies gaps are reported.
Resumo:
Ultra-performance LC coupled to quadrupole TOF/MS (UPLC-QTOF/MS) in positive and negative ESI was developed and validated to analyze metabolite profiles for urine from healthy men during the day and at night. Data analysis using principal components analysis (PCA) revealed differences between metabolic phenotypes of urine in healthy men during the day and at night. Positive ions with mass-to-charge ratio (m/z) 310.24 (5.35 min), 286.24 (4.74 min) and 310.24 (5.63 min) were elevated in the urine from healthy men at night compared to that during the day. Negative ions elevated in day urine samples of healthy men included m/z 167.02 (0.66 min), 263.12 (2.55 min) and 191.03 (0.73 min), whilst ions m/z 212.01 (4.77 min) were at a lower concentration in urine of healthy men during the day compared to that at night. The ions m/z 212.01 (4.77 min), 191.03 (0.73 min) and 310.24 (5.35 min) preliminarily correspond to indoxyl sulfate, citric acid and N-acetylneuraminic acid, providing further support for an involvement of phenotypic difference in urine of healthy men in day and night samples, which may be associated with notably different activities of gut microbiota, velocity of tricarboxylic acid cycle and activity of sialic acid biosynthesis in healthy men as regulated by circadian rhythm of the mammalian bioclock.
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Time plays an important role in norms. In this paper we start from our previously proposed classification of obligations, and point out some shortcomings of Event Calculus (EC) to represent obligations. We proposed an extension of EC that avoids such shortcomings and we show how to use it to model the various types of obligations.
Resumo:
To identify multiple sclerosis (MS) susceptibility loci, we conducted a genome-wide association study (GWAS) in 1,618 cases and used shared data for 3,413 controls. We performed replication in an independent set of 2,256 cases and 2,310 controls, for a total of 3,874 cases and 5,723 controls. We identified risk-associated SNPs on chromosome 12q13-14 (rs703842, P = 5.4 x 10(-11); rs10876994, P = 2.7 x 10(-10); rs12368653, P = 1.0 x 10(-7)) and upstream of CD40 on chromosome 20q13 (rs6074022, P = 1.3 x 10(-7); rs1569723, P = 2.9 x 10(-7)). Both loci are also associated with other autoimmune diseases. We also replicated several known MS associations (HLA-DR15, P = 7.0 x 10(-184); CD58, P = 9.6 x 10(-8); EVI5-RPL5, P = 2.5 x 10(-6); IL2RA, P = 7.4 x 10(-6); CLEC16A, P = 1.1 x 10(-4); IL7R, P = 1.3 x 10(-3); TYK2, P = 3.5 x 10(-3)) and observed a statistical interaction between SNPs in EVI5-RPL5 and HLA-DR15 (P = 0.001).