Welfare and Revenue Guarantees for Competitive Bundling Equilibrium

We study equilibria of markets with $m$ heterogeneous indivisible goods and $n$ consumers with combinatorial preferences. It is well known that a competitive equilibrium is not guaranteed to exist when valuations are not gross substitutes. Given the widespread use of bundling in real-life markets, we study its role as a stabilizing and coordinating device by considering the notion of \emph{competitive bundling equilibrium}: a competitive equilibrium over the market induced by partitioning the goods for sale into fixed bundles. Compared to other equilibrium concepts involving bundles, this notion has the advantage of simulatneous succinctness ($O(m)$ prices) and market clearance. Our first set of results concern welfare guarantees. We show that in markets where consumers care only about the number of goods they receive (known as multi-unit or homogeneous markets), even in the presence of complementarities, there always exists a competitive bundling equilibrium that guarantees a logarithmic fraction of the optimal welfare, and this guarantee is tight. We also establish non-trivial welfare guarantees for general markets, two-consumer markets, and markets where the consumer valuations are additive up to a fixed budget (budget-additive). Our second set of results concern revenue guarantees. Motivated by the fact that the revenue extracted in a standard competitive equilibrium may be zero (even with simple unit-demand consumers), we show that for natural subclasses of gross substitutes valuations, there always exists a competitive bundling equilibrium that extracts a logarithmic fraction of the optimal welfare, and this guarantee is tight. The notion of competitive bundling equilibrium can thus be useful even in markets which possess a standard competitive equilibrium

The historical role and contemporary use of corticosteroids in inflammatory bowel disease.

The use of corticosteroids to treat patients with inflammatory bowel disease (IBD) has been the bedrock of IBD therapeutics since the pioneering work of Truelove and Witts in the UK in the 1950s and subsequent large cohort studies in the US and Europe. Nevertheless, whilst effective for induction of remission, these agents do not maintain remission and are associated with a long list of recognised side effects, including a risk of increased mortality. With the arrival of an increasing number of therapies for patients with IBD, the question arises as to whether we are using these agents appropriately in contemporary practice. This review discusses the historical background to steroid usage in IBD, and also provides a brief review of the literature on side effects of corticosteroid treatment as relevant to IBD patients. Data on licensed medications is presented with specific reference to the achievement of corticosteroid-free remission. We review available international data on the incidence of corticosteroid exposure and excess and discuss some of the observations we and others have made concerning healthcare and patient-level factors associated with the risk of corticosteroid exposure, including identification of 'at-risk' populations

Electronic structure and dynamics of torsion-locked photoactive yellow protein chromophores

The photocycle of photoactive yellow protein (PYP) begins with small-scale torsional motions of the chromophore leading to large-scale movements of the protein scaffold triggering a biological response. The role of single-bond torsional molecular motions of the chromophore in the initial steps of the PYP photocycle are not fully understood. Here, we employ anion photoelectron spectroscopy measurements and quantum chemistry calculations to investigate the electronic relaxation dynamics following photoexcitation of four model chromophores, para-coumaric acid, its methyl ester, and two analogues with aliphatic bridges hindering torsional motions around the single bonds adjacent to the alkene group. Following direct photoexcitation of S1 at 400 nm, we find that both single bond rotations play a role in steering the PYP chromophore through the S1/S0 conical intersection but that rotation around the single bond between the alkene moiety and the phenoxide group is particularly important. Following photoexcitation of higher lying electronic states in the range 346-310 nm, we find that rotation around the single bond between the alkene and phenoxide groups also plays a key role in the electronic relaxation from higher lying states to the S1 state. These results have potential applications in tuning the photoresponse of photoactive proteins and materials with chromophores based on PYP

Functional Locomotor Consequences of Uneven Forefeet for Trot Symmetry in Individual Riding Horses

ABSTRACT: Left-right symmetrical distal limb conformation can be an important prerequisite for a successful performance, and it is often hypothesized that asymmetric or uneven feet are important enhancing factors for the development of lameness. On a population level, it has been demonstrated that uneven footed horses are retiring earlier from elite level competition, but the biomechanical consequences are not yet known. The objectives of this study were to compare the functional locomotor asymmetries of horses with uneven to those with even feet. Hoof kinetics and distal limb kinematics were collected from horses (n = 34) at trot. Dorsal hoof wall angle was used to classify horses as even or uneven (1.5° difference between forefeet respectively) and individual feet as flat (55°). Functional kinetic parameters were compared between even and uneven forefeet using MANOVA followed by ANOVA. The relative influences of differences in hoof angle between the forefeet and of absolute hoof angle on functional parameters were analysed using multiple regression analysis (P<0.05). In horses with uneven feet, the side with the flatter foot showed a significantly larger maximal horizontal braking and vertical ground reaction force, a larger vertical fetlock displacement and a suppler fetlock spring. The foot with a steeper hoof angle was linearly correlated with an earlier braking-propulsion transition. The conformational differences between both forefeet were more important for loading characteristics than the individual foot conformation of each individual horse. The differences in vertical force and braking force between uneven forefeet could imply either an asymmetrical loading pattern without a pathological component or a subclinical lameness as a result of a pathological development in the steeper foot

Influence of music on driver psychology and safety-relevant behaviours: a multi-study inductive content analysis

Supplemental data for this article is available online at https://doi.org/10.1080/1463922X.2021.2009933 .Copyright © 2021 The Author(s). Underpinned by pragmatism and symbolic interactionism, an inductive content analysis was conducted to assess driving experiences under a variety of music conditions. Many quantitative studies have addressed the effects of music on drivers, but there has been a conspicuous dearth of qualitative research to provide a more nuanced understanding of music-related phenomena. Data collection took place over three simulated driving studies, each with different tasks/participants (Study 1 – n = 34, Study 2 – n = 46, and Study 3 – n = 27). The inductive content analysis was conducted by two members of the research team and a peer debriefing was conducted by a third. Findings show that music can have a range of affective, behavioural and cognitive effects (both positive and negative), that are moderated by the driving environment (i.e. urban vs. highway) and aspects of the musical stimulus (i.e. inclusion/non-inclusion of lyrics, loudness and tempo). Participants were mindful of the implications of in-vehicle music vis-à-vis the safety–performance–pleasure trade-off. The analysis suggested a perceived beneficial effect of music and consequent contribution to driving style/safety-related performance. Younger drivers’ apparent reliance on music as a means by which to regulate their emotion highlights an education need in terms of optimising selections.UKRI Economic and Social Research Council grant (ES/R005559/1); Direct Line Group (UK)

Psychological and psychophysiological effects of music intensity and lyrics on simulated urban driving

© 2021 The Authors. The main aim of this study was to investigate the effect of musical characteristics (i.e., presence of lyrics and loudness) in the context of simulated urban driving. Previous work has seldom isolated musical characteristics and examined these both singularly and interactively. We investigated the potentially distracting effects of processing lyrics through exposing young drivers to the same piece of music with/without lyrics and at different sound intensities (60 dBA [soft] and 75 dBA [loud]) using a counterbalanced, within-subjects design (N = 34; Mage = 22.2 years, SD = 2.0 years). Six simulator conditions were included that comprised low-intensity music with/without lyrics, high-intensity music with/without lyrics, plus two controls – ambient in-car noise and spoken lyrics. Between-subjects variables of driving style (defensive vs. assertive) and sex (women vs. men) were explored. A key finding was that the no lyrics/soft condition yielded lower affective arousal scores when compared to the other music conditions. There was no main effect of condition for HRV data (SDNN and RMSSD). Exploratory analyses showed that, for assertive drivers, NASA-TLX Performance scores were lower in the no lyrics/soft condition compared to the lyrics/loud condition. Moreover, women exhibited higher mean heart rate than men in the presence of lyrics. Although some differences emerged in subjective outcomes, these were not replicated in HRV, which was used as an objective index of emotionality. Drivers should consider the use of soft, non-lyrical music to optimise their affective state during urban driving.UKRI Economic and Social Research Council grant (ES/R005559/ 1); Direct Line Group (UK)

The holistic phase model of early adult crisis

The objective of the current study was to explore the structural, temporal and experiential manifestations of crisis episodes in early adulthood, using a holistic-systemic theoretical framework. Based on an analysis of 50 interviews with individuals about a crisis episode between the ages of 25 and 35, a holistic model was developed. The model comprises four phases: (1) Locked-in, (2) Separation/Time-out, (3) Exploration and (4) Rebuilding, which in turn have characteristic features at four levels—person-in-environment, identity, motivation and affect-cognition. A crisis starts out with a commitment at work or home that has been made but is no longer desired, and this is followed by an emotionally volatile period of change as that commitment is terminated. The positive trajectory of crisis involves movement through an exploratory period towards active rebuilding of a new commitment, but ‘fast-forward’ and ‘relapse’ loops can interrupt Phases 3 and 4 and make a positive resolution of the episode less likely. The model shows conceptual links with life stage theories of emerging adulthood and early adulthood, and it extends current understandings of the transitional developmental challenges that young adults encounter

Quantum Symmetries and Marginal Deformations

We study the symmetries of the N=1 exactly marginal deformations of N=4 Super Yang-Mills theory. For generic values of the parameters, these deformations are known to break the SU(3) part of the R-symmetry group down to a discrete subgroup. However, a closer look from the perspective of quantum groups reveals that the Lagrangian is in fact invariant under a certain Hopf algebra which is a non-standard quantum deformation of the algebra of functions on SU(3). Our discussion is motivated by the desire to better understand why these theories have significant differences from N=4 SYM regarding the planar integrability (or rather lack thereof) of the spin chains encoding their spectrum. However, our construction works at the level of the classical Lagrangian, without relying on the language of spin chains. Our approach might eventually provide a better understanding of the finiteness properties of these theories as well as help in the construction of their AdS/CFT duals.Comment: 1+40 pages. v2: minor clarifications and references added. v3: Added an appendix, fixed minor typo

Is the qualitative research interview an acceptable medium for research with palliative care patients and carers?

<p>Abstract</p> <p>Background</p> <p>Contradictory evidence exists about the emotional burden of participating in qualitative research for palliative care patients and carers and this raises questions about whether this type of research is ethically justified in a vulnerable population. This study aimed to investigate palliative care patients' and carers' perceptions of the benefits and problems associated with open interviews and to understand what causes distress and what is helpful about participation in a research interview.</p> <p>Methods</p> <p>A descriptive qualitative study. The data were collected in the context of two studies exploring the experiences of care of palliative care patients and carers. The interviews ended with questions about patients' and carers' thoughts on participating in the studies and whether this had been a distressing or helpful event. We used a qualitative descriptive analysis strategy generated from the interviews and the observational and interactional data obtained in the course of the study.</p> <p>Results</p> <p>The interviews were considered helpful: sharing problems was therapeutic and being able to contribute to research was empowering. However, thinking about the future was reported to be the most challenging. Consent forms were sometimes read with apprehension and being physically unable to sign was experienced as upsetting. Interviewing patients and carers separately was sometimes difficult and not always possible.</p> <p>Conclusion</p> <p>The open interview enables the perspectives of patients and carers to be heard, unfettered from the structure of closed questions. It also enables those patients or carers to take part who would be unable to participate in other study designs. The context is at least as important as the format of the research interview taking into account the relational circumstances with carers and appropriate ways of obtaining informed consent. Retrospective consent could be a solution to enhancing participants control over the interview.</p