4,626 research outputs found
Understanding jumping to conclusions in patients with persecutory delusions: working memory and intolerance of uncertainty
Background. Persecutory delusions are a key psychotic experience. A reasoning style known as âjumping to conclusionsâ (JTC) â limited information gathering before reaching certainty in decision making â has been identified as a contributory factor in the occurrence of delusions. The cognitive processes that underpin JTC need to be determined in order to develop effective interventions for delusions. In the current study two alternative perspectives were tested: that JTC partially results from impairment in information-processing capabilities and that JTC is a motivated strategy to avoid uncertainty.Method. A group of 123 patients with persistent persecutory delusions completed assessments of JTC (the 60:40 beads task), IQ, working memory, intolerance of uncertainty, and psychiatric symptoms. Patients showing JTC were compared with patients not showing JTC.Results. A total of 30 (24%) patients with delusions showed JTC. There were no differences between patients who did and did not jump to conclusions in overall psychopathology. Patients who jumped to conclusions had poorer working memory performance, lower IQ, lower intolerance of uncertainty and lower levels of worry.Working memory and worry independently predicted the presence of JTC.Conclusions. Hasty decision making in patients with delusions may partly arise from difficulties in keeping information in mind. Interventions for JTC are likely to benefit from addressing working memory performance, while in vivo techniques for patients with delusions will benefit from limiting the demands on working memory. The study provides little evidence for a contribution to JTC from top down motivational beliefs about uncertainty
XXIII On the sources of the nitrogen of vegetation; with special reference to the question whether plants assimilate free or uncombined nitrogen
After referring to the earlier history of the subject, and especially' to the conclusion of Saussure, that plants derive their nitrogen from the nitrogenous compounds of the soil and the small amount of ammonia which he found to exist in the atmosphere, the Authors preface the discussion of their own experiments on the sources of the nitrogen of plants, by a consideration of the most prominent facts established by their own investigations concerning the amount of nitrogen yielded by different crops over a given area of land, and of the relation of these to certain measured, or known sources of it. On growing the same crop year after year on the same land, without any supply of nitrogen by manure, it was found that wheat, over a period of 14 years, had given rather more than 30 lbs.âbarley, over a period of 6 years, somewhat lessâmeadow-hay, over a period of 3 years, nearly 40 lbs.â and beans, over 11 years, rather more than 50 lbs. of nitrogen, per acre, per annum. Clover, another leguminous crop, grown in 3 out of 4 consecutive years, had given an average of 120 lbs. Turnips, over 8 consecutive years, had yielded about 45 lbs
FOULING DURING THE USE OF âFRESHâ WATER AS COOLANT- THE DEVELOPMENT OF A âUSER GUIDEâ
IHS ESDU recently published its latest âUser Guideâ to fouling in heat exchange systems, for systems with fresh water as the coolant. ESDU 07006 [1] is the third in a group, following the development of the Crude Oil Fouling User Guide [2] issued in 2000 and the Seawater Fouling User Guide [3] issued in 2004. ESDU 07006 was developed by IHS ESDU over a period of five years under the guidance of the Oil Industry Fouling Working Party, a collaborative team of oil refiners, heat transfer equipment and services suppliers and Universities. It provides designers and operators of cooling water facilities with a practical source of guidance on the occurrence, the mechanisms and the mitigation of fresh water fouling in these systems. IHS ESDUâs Oil Industry Fouling Working Party was formed in recognition of the huge economic and environmental importance of heat exchanger fouling and the potential benefits that can accrue from better understanding of mitigation strategies. Work is now underway on reboiler and FCCU fouling. The development of the User Guide ESDU 07006 is discussed in this paper and its technical content is summarized
Antimatter production in proton-proton and heavy-ion collisions at ultrarelativistic energies
One of the striking features of particle production at high beam energies is
the near equal abundance of matter and antimatter in the central rapidity
region. In this paper we study how this symmetry is reached as the beam energy
is increased. In particular, we quantify explicitly the energy dependence of
the approach to matter/antimatter symmetry in proton-proton and in heavy-ion
collisions. Expectations are presented also for the production of more complex
forms of antimatter like antihypernuclei.Comment: 7 pages, 5 figure
Distribution of periodic points of polynomial diffeomorphisms of C^2
This paper deals with the dynamics of a simple family of holomorphic
diffeomorphisms of \C^2: the polynomial automorphisms. This family of maps
has been studied by a number of authors. We refer to [BLS] for a general
introduction to this class of dynamical systems. An interesting object from the
point of view of potential theory is the equilibrium measure of the set
of points with bounded orbits. In [BLS] is also characterized
dynamically as the unique measure of maximal entropy. Thus is also an
equilibrium measure from the point of view of the thermodynamical formalism. In
the present paper we give another dynamical interpretation of as the
limit distribution of the periodic points of
Quantifying the Energetics and Length Scales of Carbon Segregation to Fe Symmetric Tilt Grain Boundaries Using Atomistic Simulations
Segregation of impurities to grain boundaries plays an important role in both
the stability and macroscopic behavior of polycrystalline materials. The
research objective in this work is to better characterize the energetics and
length scales involved with the process of solute and impurity segregation to
grain boundaries. Molecular dynamics simulations are used to calculate the
segregation energies for carbon within multiple grain boundary sites over a
database of 125 symmetric tilt grain boundaries in Fe. The simulation results
show that the majority of atomic sites near the grain boundary have segregation
energies lower than in the bulk. Moreover, depending on the boundary, the
segregation energies approach the bulk value approximately 5-12 \AA\ away from
the center of the grain boundary, providing an energetic length scale for
carbon segregation. A subsequent data reduction and statistical representation
of this dataset provides critical information such as about the mean
segregation energy and the associated energy distributions for carbon atoms as
a function of distance from the grain boundary, which quantitatively informs
higher scale models with energetics and length scales necessary for capturing
the segregation behavior of impurities in Fe. The significance of this research
is the development of a methodology capable of ascertaining segregation
energies over a wide range of grain boundary character (typical of that
observed in polycrystalline materials), which herein has been applied to carbon
segregation in a specific class of grain boundaries in iron
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