4,265 research outputs found
The Non-Compact Weyl Equation
A non-compact version of the Weyl equation is proposed, based on the infinite
dimensional spin zero representation of the sl_2 algebra. Solutions of the
aforementioned equation are obtained in terms of the Kummer functions. In this
context, we discuss the ADHMN approach in order to construct the corresponding
non-compact BPS monopoles.Comment: 10 pages Latex. Extra comments and an Appendix added. To appear in
JHE
k-Dirac operator and parabolic geometries
The principal group of a Klein geometry has canonical left action on the
homogeneous space of the geometry and this action induces action on the spaces
of sections of vector bundles over the homogeneous space. This paper is about
construction of differential operators invariant with respect to the induced
action of the principal group of a particular type of parabolic geometry. These
operators form sequences which are related to the minimal resolutions of the
k-Dirac operators studied in Clifford analysis
Contact Manifolds, Contact Instantons, and Twistor Geometry
Recently, Kallen and Zabzine computed the partition function of a twisted
supersymmetric Yang-Mills theory on the five-dimensional sphere using
localisation techniques. Key to their construction is a five-dimensional
generalisation of the instanton equation to which they refer as the contact
instanton equation. Subject of this article is the twistor construction of this
equation when formulated on K-contact manifolds and the discussion of its
integrability properties. We also present certain extensions to higher
dimensions and supersymmetric generalisations.Comment: v3: 28 pages, clarifications and references added, version to appear
in JHE
AIPvariant causing familial prolactinoma
Pathogenic variants in the aryl hydrocarbon receptor-interacting protein (AIP) gene are increasingly recognised as a cause of familial isolated pituitary adenoma. AIP-associated tumours are most commonly growth hormone (GH) producing. In our cohort of 175 AIP mutation positive patients representing 93 kindreds, 139 (79%) have GH excess, 19 have prolactinoma (17 familial and 2 sporadic cases) and out of the 17 clinically non-functioning tumours 4 were subsequently operated and found to be GH or GH & prolactin immunopositive adenoma. Here we report a family with an AIP variant, in which multiple family members are affected by prolactinoma, but none with GH excess. To our knowledge this is the first reported family with an AIP pathogenic variant to be affected solely by prolactinoma. These data suggest that prolactinoma families represent a small subset of AIP mutation positive kindreds, and similar to young-onset sporadic prolactinomas, AIP screening would be indicated
Using a model of group psychotherapy to support social research on sensitive topics
This article describes the exploratory use of professional therapeutic support by social researchers working on a sensitive topic. Talking to recently bereaved parents about the financial implications of their child's death was expected to be demanding work, and the research design included access to an independent psychotherapeutic service. Using this kind of professional support is rare within the general social research community, and it is useful to reflect on the process. There are likely to be implications for collection and interpretation of data, research output and the role and experience of the therapist. Here, the primary focus is the potential impact on researcher well-being
Recommended from our members
Complex picture for likelihood of ENSO-driven flood hazard
El Niño and La Niña events, the extremes of ENSO climate variability, influence river flow and flooding at the global scale. Estimates of the historical probability of extreme (high or low) precipitation are used to provide vital information on the likelihood of adverse impacts during extreme ENSO events. However, the nonlinearity between precipitation and flood magnitude motivates the need for estimation of historical probabilities using analysis of hydrological datasets. Here, this analysis is undertaken using the ERA-20CM-R river flow reconstruction for the 20th Century. Our results show that the likelihood of increased or decreased flood hazard during ENSO events is much more complex than is often perceived and reported; probabilities vary greatly across the globe, with large uncertainties inherent in the data and clear differences when comparing the hydrological analysis to precipitation
Genuine Personality Recognition from Highly Constrained Face Images
People are able to accurately estimate personality traits, merely on the basis of \u201cpassport\u201d-style neutral faces and, thus, cues must exist that allow for such estimation. However, up to date, there has been little progress in identifying the form and location of these cues. In this paper we address the problem of inferring true personality traits in highly constrained images using state of art machine learning techniques, in particular, deep networks and class activation maps analysis. The novelty of our work consists in that, differently from the vast majority of the current and past approaches (that refer to the problem of consensus personality rating prediction) we predict the genuine personality based on highly constrained images: the target\u2019s are self ratings on a validated personality inventory and we restrict to passport-like photos, in which so-called controllable cues are minimized. Our results show that self-reported personality traits can be accurately evaluated from facial features. A preliminar analysis on the features activation maps shows promising results for a deeper understanding on relevant facial cues for traits estimation
Submillimeter Studies of Prestellar Cores and Protostars: Probing the Initial Conditions for Protostellar Collapse
Improving our understanding of the initial conditions and earliest stages of
protostellar collapse is crucial to gain insight into the origin of stellar
masses, multiple systems, and protoplanetary disks. Observationally, there are
two complementary approaches to this problem: (1) studying the structure and
kinematics of prestellar cores observed prior to protostar formation, and (2)
studying the structure of young (e.g. Class 0) accreting protostars observed
soon after point mass formation. We discuss recent advances made in this area
thanks to (sub)millimeter mapping observations with large single-dish
telescopes and interferometers. In particular, we argue that the beginning of
protostellar collapse is much more violent in cluster-forming clouds than in
regions of distributed star formation. Major breakthroughs are expected in this
field from future large submillimeter instruments such as Herschel and ALMA.Comment: 12 pages, 9 figures, to appear in the proceedings of the conference
"Chemistry as a Diagnostic of Star Formation" (C.L. Curry & M. Fich eds.
Photodissociation dynamics of methyl iodide probed using femtosecond extreme ultraviolet photoelectron spectroscopy
Femtosecond pump-probe photoelectron spectroscopy measurements using an extreme ultraviolet probe have been made on the photodissociation dynamics of UV (269 nm) excited CH3I. The UV excitation leads to population of the 3Q0 state which rapidly dissociates. The dissociation is manifested as shifts in the measured photoelectron kinetic energy that map the extending C-I bond. The increased energy available in the XUV probe relative to a UV probe means the dynamics are followed over the chemically important region as far as C-I bond lengths of approximately 4 Å
- …