504 research outputs found
Cognitive Bias Modification for Depression
No full textChapter titled, "Cognitive Bias Modification for Depression" written by Christopher G. Beevers, Mary E. McNamara, Mackenzie Zisser, and Rachel L. Weisenburger for a forthcoming book, APA Handbook of Depression, edited by Jeremy Pettit and Thomas Olino
Analysis code for manuscript and supplemental materials
No full textAnalysis code used in manuscript: Self-referent encoding and depression symptoms: An intensive sampling approach by Rachel L. Weisenburger, Justin Dainer-Best, Mackenzie Zisser, Mary E. McNamara, Christopher G. Beever
Making different decisions: the influence of climate model uncertainty on dynamic adaptation pathways
No full textDimond, J., Roose, W., & Beevers, L. (2025). Making different decisions: the influence of climate model uncertainty on dynamic adaptation pathways [Data set]. Zenodo. https://doi.org/10.5281/zenodo.1498749
Making different decisions: demonstrating the influence of climate model uncertainty on dynamic adaptation pathways
No full textDimond, J., Roose, W., & Beevers, L. (2025). Making different decisions: demonstrating the influence of climate model uncertainty on dynamic adaptation pathways [Data set]. Zenodo. https://doi.org/10.5281/zenodo.1519561
Pumped hydro storage plants with improved operational flexibility using constant speed Francis runners
No full textPumped hydro storage (PHS) is a crucial technology for balancing large steam power plants, and may become increasingly important for storing renewable energies. Hence, capacity ranges of PHS, as well as its dynamic response to renewable power variability, will become progressively relevant. In this paper, we focus on determining capacity ranges and efficiencies of PHS plants using conventional constant speed Francis runners, adopting unconventional runner sets, arranged in innovative fashion. In the pumping mode, it is assumed that the impellers run at a single speed, but that they can have, depending on the plant, either the same or different design capacities. In the turbine mode, it is assumed that the runners can access the well-established range from 60% to 100% of design capacity via wicket gate adjustment. In order to extend the capacity ranges with constant speed runners, bypass loops to balance the plant are considered. Because bypass operation implies losses, the possible efficiencies are studied. The results show that (a) bypass is an effective means of extending capacity ranges, but high by-pass ratios decrease efficiencies. (b) One of the impeller sets postulated in this work offers the possibility of almost continuous capacity at high efficiencies, with relatively small capacity variation within the set
Rotation-tunnel de l'ammonium dans l' alumine β
No full textWe present a study of the NMR spectrum of protons belonging to ammonium ions in ammonium β-alumina, at low temperature. We show that ammonium ions in Beevers-Ross sites undergo a fast rotational tunnelling which gives rise to a strong narrowing of their NMR spectrum, while ammonium ions in mid-oxygen sites are static and give a broad spectrum. By examining a mixed sodium-ammonium sample, we have been able to separate the spectrum of Beevers-Ross ions. The theory of magnetic resonance of protons belonging to NH+4 ions submitted to a fast rotational tunnelling, as formalized by Lalowicz et al., is applied. It yields a very nice agreement with the experimental spectrum. This also allows the stable orientation of the NH4 tetrahedron in the Beevers-Ross site to be determined.Nous présentons une étude du spectre de résonance magnétique des protons appartenant aux ions NH+4 dans l'alumine β à l'ammonium, à basse température. Nous montrons que les ions en site Beevers-Ross sont soumis à une rotation-tunnel rapide qui se manifeste par un rétrécissement de la raie de résonance, alors que les ions en site mid-oxygen apparaissent comme statiques et donnent une raie large. En opérant sur un échantillon mixte sodium-ammonium, nous avons pu isoler le spectre des ions Beevers-Ross. L'application de la théorie du spectre des protons de l'ion ammonium dans le cas d'un rétrécissement par la rotation-tunnel, formalisée par Lalowicz et al., fournit une description remarquablement bonne des spectres expérimentaux et permet de déterminer l'orientation d'équilibre du tétraèdre NH4 dans le site Beevers-Ross
Symptom centrality and infrequency of endorsement identify adolescent depression symptoms more strongly associated with life satisfaction
No full textAlthough depression symptoms are often treated as interchangeable, some symptoms may relate to adolescent life satisfaction more strongly than others. To assess this premise, we first conducted a network analysis on the Mood and Feelings Questionnaire (MFQ) in a large (N = 1,059), cross-sectional sample of community adolescents (age M = 14.72 ± 1.79). The most central symptoms of adolescent depression, as indexed by strength, were self-hatred, loneliness, sadness, and worthlessness while the least frequently endorsed symptoms were self-hatred, anhedonia, feeling like a bad person, and feeling unloved. Moreover, the more central a depression symptom was in the network (i.e., higher strength), the more variance it shared with life satisfaction (r = 0.59, 95% CI: 0.27, 0.76). How frequently a symptom was endorsed was negatively associated with the variance symptoms shared with life satisfaction (r = -0.48, 95% CI: -0.63, -0.21). Cross-validated, prediction focused models found central symptoms were expected to predict more out of fold variance in life satisfaction than peripheral symptoms and frequently endorsed symptoms, but not the least frequently endorsed symptoms. These findings show certain depression symptoms may be more strongly associated with life satisfaction in adolescence and these symptoms can be identified by multiple symptom-level metrics. Limitations include use of cross-sectional data and utilizing a community sample. Better understanding which symptoms of depression share more variance with important outcomes like life satisfaction could help us develop a more fine-grained understanding of adolescent depression
The influence of plastic deformation mechanisms on the corrosion-fatigue behaviour of ferritic stainless steels.
No full textC.J. Beevers ed.International audienc
The development and applications of the combined use of NMR and ultrasound
No full textThe objective of the research carried out in this report was to observe the first ever in-situ sonochemical reaction in the NMR Spectrometer in the megahertz region of ultrasound. Several reactions were investigated as potential systems for a sonochemical reaction followed by NMR spectroscopy. The primary problem to resolve when applying ultrasound to a chemical reaction is that of heating. Ultrasound causes the liquid to move and produces 'hot spots' resulting in an increase in sample temperature. The problem was confronted by producing a device that would counteract this effect and so remove the need to account for heating. However, the design of the device limited the length of time during which it would function. Longer reaction times were required to enable observations to be carried out in the NMR spectrometer. The fIrst and most obvious reactions attempted were those of the well-known ultrasonic dosimeter. Such a reaction would, theoretically, enable the author to simultaneously observe a reaction and determine the exact power entering the system for direct comparison of results. Unfortunately, in order to monitor the reactions in the NMR spectrometer the reactant concentrations had to be signifIcantly increased, which resulted in a notable increase in reaction time, making the experiment too lengthy to follow in the time allocated. The Diels-Alder Reaction is probably one of the most highly investigated reaction systems in the field of chemistry and it was this to which the author turned her attention. Previous authors have carried out ultrasonic investigations, with considerable success, for the reaction of anthracene with maleic anhydride. It was this reaction in particular that was next attempted. The first ever sonochemically enhanced reaction using a frequency of ultrasound in the megahertz (MHz) region was successfully carried out as bench experiments. Due to the complexity of the component reactants the product would precipitate from the solution and because the reaction could only be monitored by its formation, it was not possible to observe the reaction in the NMR spectrometer. The solvolysis of 2-chloro-2-methylpropane was examined in various solvent systems; the most suitable of which was determined to be aqueous 2-methylpropan-2-ol. The experiment was successfully enhanced by the application of ultrasound and monitored in-situ in the NMR spectrometer. The increase in product formation of an ultrasonic reaction over that of a traditional thermal reaction occurred. A range of 1.4 to 2.9 fold improvement was noted, dependent upon the reaction conditions investigated. An investigation into the effect of sonication upon a large biological molecule, in this case aqueous lysozyme, was carried out. An easily observed effect upon the sample was noted but no explanation for the observed effects could be established
Characterization of clathrin adaptor proteins from cotyledons of developing pea (Pisum sativum L.).
No full textProcedures have been developed for the dissociation of coat proteins from clathrin-coated vesicles isolated from cotyledons of developing pea, Pisum sativum L. Based on molecular sizing chromatography, immunoreactivity, subunit composition and interaction with both clathrin and vacuolar targeting receptors we have identified adaptor protein complexes among the dissociated proteins. These adaptor proteins exist as large globular complexes of similar molecular mass and subunit composition to those of mammals. A single 110kD subunit is immunologically related to the -adaptins of bovine brain. Candidates for subunits are also present. In addition to the large subunit homologs, two -adaptin candidates of 47 and 50kD bind to an affinity matrix coupled to antibodies against the mammalian adaptins, providing evidence for two adaptor complexes in plants. Pea cotyledon clathrin readily self-assembles into polyhedric coats upon dialysis under assembly conditions. Clathrin and calcium concentrations and pH have similar effects on cage assembly of both plant and brain clathrin. Under physiological conditions, pea cotyledon clathrin-adaptor proteins are incorporated into and affect both the diameter and size distribution of coats formed in their presence, but are not required for assembly. Adaptor proteins from bovine brain markedly stimulated assembly of pea clathrin into hybrid coats intermediate in size between those of brain and pea cotyledon. Both the brain adaptors were incorporated into these structures. In contrast, no stimulation of assembly was observed when pea cotyledon adaptors were dialyzed with brain clathrin under assembly conditions. Evidence of an "adaptor" function is provided by the binding of purified pea cotyledon adaptors to a transmembrane vacuolar targeting receptor, BP-80, present in clathrin-coated vesicles and a less-dense membrane fraction. In similarity to a number of mammalian transmembrane receptors, the cytoplasmic tail of BP-80 contains a canonical tyrosine-sorting motif of the form YXXO Component polypeptides of adaptors from pea cotyledon-, wheat germ- and bovine brain-coated vesicles bind specifically to an immobilized peptide corresponding to the entire cytoplasmic domain of the Arabidopsis homolog of BP-80, and to a trucated peptide containing the tyrosine motif, suggesting a universality in the mechanisms of protein sorting and targeting in the endomembrane systems of plants and animals
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