4,791 research outputs found

    Altruism and the pressure to share: Lab evidence from Tanzania

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    We propose a novel laboratory experiment to document the pressure to share income within social networks in Africa. We find that the redistributive pressure exerted via the possibility of receiving a claim increases altruism, while the possibility of hiding from such claim reduces it. Our results indicate that sharing norms are crucial drivers of giving to other members of the network. We also find that pressure to share has a detrimental effect on the undertaking of profitable but risky investments

    The Impact Of Cultural Differences On The Effectiveness Of Advertisements On The Internet: A Comparison Among The United States, China, And Germany

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    Hall and Hall (1990) classify German culture as a low-context culture, American culture as a medium/low-context culture, and Chinese culture as a high-context culture. A low-context culture is one where the words contain most of the information needed and there is little need to rely on the context of the events/message to help interpreting the meaning of the message/events. In contrast, a high-context culture is one where the context of the message is as important as or even more important than the words. This paper focuses on selected cultural differences among Germany, United States, and China, and the impact of these differences on the various aspects of consumer behavior. Specifically, it is focusing on the impact of cultural context on the effectiveness of the different styles of advertising.

    Fluorescence Spectroscopy of the Tryptophan Microenvironment in Carcinus aestuarii Hemocyanin

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    The steady-state and time-resolved fluorescence properties of the multitryptophan minimal subunit CaeSS2 from Carcinus aestuarii hemocyanin have been studied with the aim of probing the environment of the fluorophores within the protein matrix. Subunit a of Panulirus interruptus hemocyanin, whose X-ray structure is known, has been also studied. The results are compared with those collected with other two monomeric fractions (CaeSS1, CaeSS3) produced by dissociation of the native, oligomeric protein as well as with those of the hexameric aggregate. Three classes of tryptophan residues can be singled out by a combination of fluorescence quenching and lifetime measurements on the holo-Hc (the copper containing, oxygen binding form) and the apo-Hc (the copper-free derivative). One class of tryptophans is exposed to the protein surface. Some of these residues are proposed to be involved in the intersubunit interactions in CaeSS1 and CaeSS3 fractions whereas in CaeSS2 the protein matrix masks them. This suggests the occurrence of conformational rearrangements after detachment of the subunit from the native aggregate, which could explain the inability of CaeSS2 to reassociate. A second class of tryptophan has been correlatively assigned, by comparison with the results obtained with Panulirus interruptus hemocyanin, to residues in close proximity to the active site. The third class includes buried, active site-distant, residues

    Statistical and Proactive Analysis of an Inter-Laboratory Comparison: The Radiocarbon Dating of the Shroud of Turin.

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    We review the sampling and results of the radiocarbon dating of the archaeological cloth known as the Shroud of Turin, in the light of recent statistical analyses of both published and raw data. The statistical analyses highlight an inter-laboratory heterogeneity of the means and a monotone spatial variation of the ages of subsamples that suggest the presence of contaminants unevenly removed by the cleaning pretreatments. We consider the significance and overall impact of the statistical analyses on assessing the reliability of the dating results and the design of correct sampling. These analyses suggest that the 1988 radiocarbon dating does not match the current accuracy requirements. Should this be the case, it would be interesting to know the accurate age of the Shroud of Turin. Taking into account the whole body of scientific data, we discuss whether it makes sense to date the Shroud again

    Pegaso: an ultra-light long duration stratospheric

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    Launched from the Mario Zuccelli Station (Baia Terra Nova) in Antarctica during the 2005/06 austral summer, the PEGASO-D payload lifted into the stratospheric anticyclone over the southern polar region. This effort marks the first Long Duration Scientific payload to be launched from this location and is the fourth such payload launched in the polar regions. Performing in the framework of the NOBILE/AMUNDSEN collaborative LDB development between ASI-ARR. The Italian Institute of Geophysics and Volcanology (INGV), with the sponsorship of the Italian Antarctic Program (PNRA) and the Italian Space Agency (ASI),designed and built the Ultra-Light system together with three Universities in Italy. The Pegaso program has been created to investigate the Earth magnetic field and provide a precursor series of small payload launches for the bigger LDB program such as OLIMPO, BOOMERanG and BArSPOrt through this collaboration between ASI and ARR. The Italian scientific community, aware of the big advantages that LDB balloons can offer to their experiments, proposed to extend the LDB program to Southern polar regions, besides performing launches from the newly initiated Nobile/Amundsen Stratospheric Balloon Center in Svalbard, Norway.Three PEGASO (Polar Explorer for Geomagnetics And other Scientific Observations) payloads have been launched from the Svalbard (No) in collaboration with Andoya Rocket Range, ASI and ISTAR (Operations and logistics) during the past two northern summers. These stratospheric (altitude m.35000) small 10kmc balloons have floated in the stratosphere between 14 to 39 days measuring the magnetic field of polar regions, by means of a 3-axys-fluxgate magnetometer, during a three year campaign. The study of the magnetic field and its variations is done through permanent observatories. They provide us with high quality data but their spatial distribution is not quite regular, specially in Antarctica due to logistic difficulties. The coverage is improved through marine and aeromagnetic surveys, and also through satellite missions. There exists nevertheless a gap in the wavelengths of the magnetic field represented by these kind of measurements. Satellite data are too far away from Earth's surface to individuate wavelengths lower than 1000 km, and near-ground sur- veys are not able to represent wavelengths longer than the dimensions of the surveyed area. Moreover, there is a region empty of data around the geographical pole for the satellite measurements. The size of these gaps depends on the orbital parameters, but it can reach up to 10 degrees around the pole. PEGASO allows to bridge this gap in the measurements of the magnetic field. Surveys carried out at 35 km height allow the study of crustal anomalies in the range between, we can say, 60 and 1000 km. Taking into account that pathfinders (smaller non-recoverable balloon systems) are usually sent to explore the atmospheric currents, the use of PEGASO as pathfinder allows us to obtain all these results at a very affordable cost. The PEGASO payload was also developed as a single source system integrating science, housekeeping and operational control of the entire balloon borne configuration.Satellite telemetry sent the scientific (magnetometric) data, house-keeping (temperature, solar panel voltage and current, altitude and time) and telecommand (four ballast, two parachute release system, system reset), and powered the terminate system. Data flows through the IRIDIUM telephone service. The onboard systems were kept inside a vessel (white painted and pressurizzed vessel due to power dissipation) except for external flexible solar panels and magnetometer, attached to an external boom. Two redundant tracking systems have been used: a first GPS was integrated inside the on-board telemetry system, necessary to reconstruct position and time of scientific data, while an independent GPS-ARGOS system gave the balloon trajectory, including its descent. Continuous trajectory predictions were made during the missions; they have been necessary, in particular, for the flight safety requirements of the northern hemisphere. The evaluation of the statistical error is proposed. The PEGASO payload was developed to be a light, cost effective way to explore the potential of Ultra-Light Long Duration Ballooning for science as well as an introduction to the earth-space possibilities for students.PublishedBeijing, China1A. Geomagnetismo e Paleomagnetism

    Multimodal Imaging of Macular Telangiectasia Type 2: Focus on Vascular Changes Using Optical Coherence Tomography Angiography

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    PURPOSE. To report morphologic features of idiopathic macular telangiectasia (MacTel) type 2 by means of optical coherence tomography angiography (OCTA) and to compare these findings to fundus fluorescein angiography (FFA), fundus autofluorescence (FAF), confocal blue reflectance (CBR), and spectral-domain OCT (SD-OCT). In addition, foveal vessel density and parafoveal vascular density (PFVD), and foveal retinal thickness and parafoveal retinal thickness (PFRT) were compared between MacTel 2 patients and normal aged-matched controls. METHODS. Eight patients (15 eyes) with MacTel 2 and 17 normal controls (17 eyes) underwent retinal multimodal imaging assessment and grading. Results from different imaging techniques were used to compare interimaging modalities. Objective quantification of retinal vessel density and macular thickness was evaluated in MacTel 2 patients (15 eyes). RESULTS. In MacTel 2 eyes a comparison of OCTA to the other imaging techniques showed that the strongest correlations were present with SD-OCT, early FFA, and late FFA. Moderate correlations were found between OCTA and CBR and FAF. Foveal vessel density was significantly lower in MacTel 2 eyes than control eyes both in the superficial plexus (23.74% vs. 33.14%; P = 0.003) and in the deep plexus (24.63% vs. 34.21%; P = 0.005). Superficial PFVD was significantly different in the two groups (47.06% vs. 51.40%; P = 0.005) but not the deep PFVD. Foveal retinal thickness was 214.13 mu m in MacTel 2 eyes and 258.18 mu m in normal controls, and PFRT was 279.60 and 323.29 mu m, respectively (P CONCLUSIONS. Optical coherence tomography angiography is useful for retinal vasculature characterization in MacTel type 2 patients and showed a high correlation with well-established imaging techniques
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