152 research outputs found

    Relevance of the weak equivalence principle and experiments to test it: lessons from the past and improvements expected in space

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    Tests of the Weak Equivalence Principle (WEP) probe the foundations of physics. Ever since Galileo in the early 1600s, WEP tests have attracted some of the best experimentalists of any time. Progress has come in bursts, each stimulated by the introduction of a new technique: the torsion balance, signal modulation by Earth rotation, the rotating torsion balance. Tests for various materials in the field of the Earth and the Sun have found no violation to the level of about 1 part in 1e13. A different technique, Lunar Laser Ranging (LLR), has reached comparable precision. Today, both laboratory tests and LLR have reached a point when improving by a factor of 10 is extremely hard. The promise of another quantum leap in precision rests on experiments performed in low Earth orbit. The Microscope satellite, launched in April 2016 and currently taking data, aims to test WEP in the field of Earth to 1e-15, a 100-fold improvement possible thanks to a driving signal in orbit almost 500 times stronger than for torsion balances on ground. The `Galileo Galilei' (GG) experiment, by combining the advantages of space with those of the rotating torsion balance, aims at a WEP test 100 times more precise than Microscope, to 1e-17. A quantitative comparison of the key issues in the two experiments is presented, along with recent experimental measurements relevant for GG. Early results from Microscope, reported at a conference in March 2017, show measurement performance close to the expectations and confirm the key role of rotation with the advantage (unique to space) of rotating the whole spacecraft. Any non-null result from Microscope would be a major discovery and call for urgent confirmation; with 100 times better precision GG could settle the matter and provide a deeper probe of the foundations of physics.Comment: To appear: Physics Letters A, special issue in memory of Professor Vladimir Braginsky, 2017. Available online: http://dx.doi.org/10.1016/j.physleta.2017.09.02

    Validity and measurement invariance of the Unified Multidimensional Calling Scale (UMCS): A three-wave survey study

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    The accumulation of scientific knowledge on calling is limited by the absence of a common theoretical and measurement framework. Many different models of calling have been proposed, and we do not know how much research results that refer to a specific model are generalizable to different theoretical accounts of calling. In this article, we investigate whether two leading models of calling tackle the same construct. The two models were merged into a comprehensive framework that measures calling across seven facets: Passion, Purposefulness, Sacrifice, Pervasiveness, Prosocial Orientation, Transcendent Summons, and Identity. We then developed the Unified Multidimensional Calling Scale (UMCS) drawing from previous published items. Across two surveys involving college students (N = 5886) and adult employees (N = 205) the UMCS was proved to be valid and reliable. We also observed that the UMCS is invariant across time and calling domains. Finally, we found that facets of calling have very different relationships with outcomes and concurrent measures, suggesting that results obtained with a smaller set of facets are not generalizable to the higher-order construct of calling or to a different model that does not share the same facets. \ua9 2018 Vianello et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    Testing the equivalence principle in space after the MICROSCOPE mission

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    Tests of the weak equivalence principle (WEP) can reveal a new, composition dependent, force of nature, or disprove many models of new physics. For the first time, such a test is being successfully carried out in space by the MICROSCOPE satellite. Early results show no violation of the WEP sourced by the Earth for Pt and Ti test masses with random errors (after 8.26 d of integration time) of about 1 part in 1014 and systematic errors of the same magnitude. This result improves by about 10 times over the best ground tests with rotating torsion balances despite 70 times less sensitivity to differential accelerations, thanks to the much stronger driving signal in orbit. The measurement is limited by thermal noise from internal damping in the gold wires used for electrical grounding, related to their fabrication and clamping. This noise was shown to decrease when the spacecraft was set to rotate faster than planned. The result will improve by the end of the mission, as thermal noise decreases with more data. Not so systematic errors. We investigate major nongravitational effects and find that MICROSCOPE's "zero-check" sensor, with test masses both made of Pt, does not allow their separation from the signal. The early test reports an upper limit of systematic errors in the Pt-Ti sensor, which are not detected in the Pt-Pt one, hence would not be distinguished from a violation. Once all the integration time available is used to reduce random noise, there will be no time left to check systematics. MICROSCOPE demonstrates the huge potential of space for WEP tests of very high precision and indicates how to reach it. To realize the potential, a new experiment needs the spacecraft to be in rapid, stable rotation around the symmetry axis (by conservation of angular momentum), needs high quality state-of-the-art mechanical suspensions as in the most precise gravitational experiments on ground, and must allow multiple checks to discriminate a violation signal from systematic errors. The design of the "Galileo Galilei" (GG) experiment, aiming to test the WEP to 1 part in 1017 unites all the needed features, indicating that a quantum leap in space is possible provided the new experiment heeds the lessons of MICROSCOPE

    The Developmental Trajectories of Calling: Predictors and Outcomes:

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    There are many open questions concerning the development of calling, and longitudinal empirical evidence is limited. We know that a calling is associated with many beneficial outcomes, but we do not know how it changes through time and what predicts these changes. Previous studies have shown that calling is relatively stable at the sample level. We show that, at the individual level, calling shows huge variations through time. We identified nine developmental trajectories that are typical across facets of calling, and we found evidence that the development of a calling is fostered by the extent to which individuals have lived it out. We also observed that the more a calling has grown over a 2-year period, the more it is lived out during the third year. These results provide support for a developmental model of calling according to which having a calling and living it out reciprocally influence each other. The practical and theoretical implications of these results are discussed

    The Developmental Trajectories of Calling: Predictors and Outcomes

    Get PDF
    There are many open questions concerning the development of calling, and longitudinal empirical evidence is limited. We know that a calling is associated with many beneficial outcomes, but we do not know how it changes through time and what predicts these changes. Previous studies have shown that calling is relatively stable at the sample level. We show that, at the individual level, calling shows huge variations through time. We identified nine developmental trajectories that are typical across facets of calling, and we found evidence that the development of a calling is fostered by the extent to which individuals have lived it out. We also observed that the more a calling has grown over a 2-year period, the more it is lived out during the third year. These results provide support for a developmental model of calling according to which having a calling and living it out reciprocally influence each other. The practical and theoretical implications of these results are discussed

    COPSEC: Compliance-Oriented IoT Security and Privacy Evaluation Framework

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    A rising number of Internet of Things (IoT) security and privacy threats have been documented over the last few years. However, IoT devices' domain designs are out-of-date and do not take into consideration the changing dangers associated with them. In this paper, we present COPSEC, a novel framework for evaluating whether IoT devices are compliant with security guidelines and privacy regulations. We extract metrics from existing guidelines and regulations and test them on a set of devices by performing hundreds of automated experiments. Our results indicate not only that these devices are not compliant with basic security guidelines, but also that their data collection operations may introduce privacy risks for the users that adopt them

    Weekend mortality in an Italian hospital: immediate versus delayed bedside critical care treatment

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    Background: a number of studies highlighted increased mortality associated with hospital admissions during weekends and holidays, the so-call "weekend effect". In this retrospective study of mortality in an acute care public hospital in Italy between 2009 and 2015, we compared inpatient mortality before and after a major organizational change in 2012. The new model (Model 2) implied that the intensivist was available on call from outside the hospital during nighttime, weekends, and holidays. The previous model (Model 1) ensured the presence of the intensivist coordinating a Medical Emergency Team (MET) inside the hospital 24 h a day, 7 days a week. Methods: life status at discharge after 9298 and 8223 hospital admissions that occurred during two consecutive periods of 1185 days each (organizational Model 1 and 2), respectively, were classified into "discharged alive", "deceased during nighttime-weekends-holidays" and "deceased during daytime-weekdays". We estimated Relative Risk Ratios (RRR) for the associations between the organizational model and life status at discharge using multinomial logistic regression models adjusted for demographic and case-mix indicators, and timing of admission (nighttime-weekends-holidays vs. daytime-weekdays). Results: there were 802 and 840 deaths under Models 1 and 2, respectively. Total mortality was higher for hospital admissions under Model 2 compared to Model 1. Model 2 was associated with a significantly higher risk of death during nighttime-weekends-holidays (IRR: 1.38, 95% CI 1.20-1.59) compared to daytime-weekdays (RRR: 1.12, 95% CI 0.97-1.31) (p = 0.04). Respiratory diagnoses, in particular, acute and chronic respiratory failure (ICD 9 codes 510-519) were the leading causes of the mortality excess under Model 2. Conclusions: our data suggest that the immediate availability of an intensivist coordinating a MET 24 h, 7 days a week can result in a better prognosis of in-hospital emergencies compared to delayed consultation
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