65,029 research outputs found
The International Study of Insulin and Cancer
No full textThe international study of insulin and cancer.
Grimaldi-Bensouda L, Marty M, Pollak M, Cameron D, Riddle M, Charbonnel B, Barnett AH, Boffetta P, Boivin JF, Evans M, Rossignol M, Benichou J, Abenhaim L; ISICA group
Lower Bounds for Nonrelativistic Atomic Energies
No full textA recently developed lower bound theory for Coulombic problems (E. Pollak, R. Martinazzo, J. Chem. Theory Comput. 2021, 17, 1535) is further developed and applied to the highly accurate calculation of the ground-state energy of two- (He, Li+, and H-) and three- (Li) electron atoms. The method has been implemented with explicitly correlated many-particle basis sets of Gaussian type, on the basis of the highly accurate (Ritz) upper bounds they can provide with relatively small numbers of functions. The use of explicitly correlated Gaussians is developed further for computing the variances, and the necessary modifications are here discussed. The computed lower bounds are of submilli-Hartree (parts per million relative) precision and for Li represent the best lower bounds ever obtained. Although not yet as accurate as the corresponding (Ritz) upper bounds, the computed bounds are orders of magnitude tighter than those obtained with other lower bound methods, thereby demonstrating that the proposed method is viable for lower bound calculations in quantum chemistry applications. Among several aspects, the optimization of the wave function is shown to play a key role for both the optimal solution of the lower bound problem and the internal check of the theory
Visual vertigo: symptom assessment, spatial orientation and postural control
No full textCertain patients with balance disorders report a 'visual vertigo' in which their symptoms are provoked or aggravated by specific visual contexts (e.g. supermarkets, driving or movement of objects). In order to determine the causes of visual vertigo (VV), we assessed symptoms, anxiety and the influence of disorienting visual stimuli in 21 such patients. In 17 out of 21 patients, a peripheral vestibular disorder was diagnosed. Sixteen bilateral labyrinthine-defective subjects (LDS) and 25 normal subjects served as controls. Questionnaire assessment showed that the levels of trait anxiety and childhood motion sickness in the three subject groups were not significantly different. Reporting of autonomic symptoms and somatic anxiety was higher than normal in both patient groups but not significantly different between LDS and VV patients. Handicap levels were not different in the two patient groups, but the reporting of vestibular symptoms was higher in the VV than in the LDS group. The experimental stimuli required subjects to set the subjective visual vertical in three visual conditions: total darkness, in front of a tilted luminous frame (rod and frame test) and in front of a large disc rotating in the frontal plane (rod and disc test). Body sway was also measured in four visual conditions: eyes closed, eyes open, facing the tilted frame and during disc rotation. In psychophysical and postural tests, both LDS and VV patients showed: (i) a significant increase in the tilt of the visual vertical both with the static tilted frame and with the rotating disc; and (ii) an increased postural deviation whilst facing the tilted frame and the rotating disc. The ratio between sway path with eyes closed and eyes open (i.e. the stabilizing effect of vision) was increased in the LDS, but not in VV patients, compared with normal subjects. In contrast, the ratio between sway path during disc rotation and sway path during eyes open (i.e. the destabilizing effect of a moving visual stimulus) was increased in the VV patients but not in LDS. Taken together, these data show that VV patients have abnormally large perceptual and postural responses to disorienting visual environments. VV is not related to trait anxiety or a past history of motion sickness. The results indicate that VV emerges in vestibular patients if they have increased visual dependence and difficulty in resolving conflict between visual and vestibulo-proprioceptive inputs. It is argued that treating these patients with visual motion desensitization, e.g. repeated optokinetic stimulation, should be beneficial
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Production and performance of thin and thick film NTCR thermistors based on NiMn(_2)O(_4)+δ
No full textIn this study reliable film type NTCR thermistors based on NiMn(_2)O(_4)+δ were produced and their electrical properties were studied in detail. Electron-beam evaporation procedures have been applied to produce thin film NTCR thermistors. Phase pure NiMn(_2)O(_4)+δ target material was produced via a traditional ceramic precursor oxide route and thin films were deposited in an optimised procedure. The thickness distribution of evaporated films showed good agreement with a theoretical model, derived from evaporation theory and the sticking coefficient of the vapour on the substrates was approximately 80% ± 1.5%. The composition of electron-beam evaporated films was found to be not controllable in terms of the phase purity and the Ni : Mn ratio. In order to avoid these problems thick film NiMn(_2)O(_4)+δ NTCR thermistors were developed using direct screen-printing techniques. Detailed Rietveld refinement analysis was carried out for the source powder used for screen-printing. The main focus of the work was the measurement of resistance-temperature (R-T) characteristics of thin and thick films and pellets. In the temperature range of concern (77 K -550 K) conduction was found to be by variable-range hopping (VRH) and nearest-neighbour hopping (NNH); R ~ exp (TʆT)(^p), where the index p depends on the mode of hopping. Detailed analysis of R-T data showed that screen-printed films and pellets exhibited a p-value of 0.5, which was identified with VRH with a parabolic density of states (DOS) with an exponential dependence of resistance: R ~ exp (TʆT)(^0.5). For electron-beam evaporated films the mechanisms detected were NNH: R ~ exp (TʆT); and VRH with a constant DOS {p = 0.25) following: R ~ exp (TʆT)(_0.25). For screen-printed films with incorporated glass phase the electrical conduction mechanism was analysed using a.c. impedance spectroscopy and at low frequencies the hopping conduction was in agreement with the d.c. behaviour. The time constant of this mechanism could be described by an equivalent circuit containing a RC element. For higher frequencies a second mechanism was found, best described by a CRL element
Stable voters in an unstable party environment : continuity and change in Italian electoral behaviour
No full textM.24981-1999 Paolo Segatti, Paolo Bellucci and Marco Maraffi. 30 cm. A previous version of this paper was presented at a symposium on Political Parties : Changing Roles in Contemporary Democracies, held at the Center for Advanced Study in the Social Sciences of the Juan March Institute, Madrid, December 15-17, 1994. -- P.1. Includes bibliographical references (p. 56-59
Barrett_Supplemental_Material – Supplemental material for Emotional Expressions Reconsidered: Challenges to Inferring Emotion From Human Facial Movements
No full textSupplemental material, Barrett_Supplemental_Material for Emotional Expressions Reconsidered: Challenges to Inferring Emotion From Human Facial Movements by Lisa Feldman Barrett, Ralph Adolphs, Stacy Marsella, Aleix M. Martinez and Seth D. Pollak in Psychological Science in the Public Interest</p
sj-docx-1-asm-10.1177_10731911221134601 – Supplemental material for The Process Model of Emotion Regulation Questionnaire: Assessing Individual Differences in Strategy Stage and Orientation
No full textSupplemental material, sj-docx-1-asm-10.1177_10731911221134601 for The Process Model of Emotion Regulation Questionnaire: Assessing Individual Differences in Strategy Stage and Orientation by Sally Olderbak, Andero Uusberg, Carolyn MacCann, Katja M. Pollak and James J. Gross in Assessment</p
Gary Becker's Contributions to Family and Household Economics
No full textGary Becker's influence on the economics of the family has been pervasive. His ideas have dominated research in the economics of the family, shaping the tools we use, the questions we ask, and the answers we give. The foundational assumptions of Becker's economic approach to the family -- maximizing behavior and equilibrium -- as well as such primary auxiliary assumptions as household production and interdependent preferences, are now widely accepted not only by economists but also by family sociologists, demographers, and others who study the family. Yet the interesting and provocative implications of Becker's economic approach to the family do not follow from the foundational assumptions or from the primary auxiliary assumptions. Instead they depend on contested auxiliary assumptions to which neoclassical economics has no commitment and which lack empirical support. This paper discusses the crucial role of auxiliary assumptions in Becker's analysis of the family, first in the context of preferences, then in the context of household production, and finally in the context of family or household collective choice.
Word-sense Induction on a Corpus of Buddhist Sanskrit
No full textMatej Martinc, Andraž Pelicon, Senja Pollak, Ligeia Lugli. 2023. Word-sense Induction on a Corpus of Buddhist Sanskrit Literature. In Medveď, M. & Měchura, M. & Tiberius, C. & Kosem, I. & Kallas, J. & Jakubíček, M. & Krek, S. (eds.). Electronic lexicography in the 21st century (eLex 2023): Invisible Lexicography. Proceedings of the eLex 2023 conference, pages 201-215.</p
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