When Words Matter Most: Positive Psychology Perspectives on Condolence Letters

While the focus of positive psychology is uncontestably on the positive, there is an emerging direction in the field indicating that the coexistence of both negative and positive emotions is critical to well-being. The act of writing a condolence letter is a good example of precisely this coexistence: loss and sorrow giving rise to the act of expressive writing to convey positive emotions of sympathy, solace, and more. Viewed through the lens of positive psychology, writing a condolence letter has the potential to activate a unique alchemy of elements that the science of positive psychology has identified with well-being, from calling to action over inaction, meaning over despair, and resilience over hopelessness; to identifying character strengths and virtues and enhancing social bonds and generativity; to practicing the master virtue of practical wisdom in modulating the letter’s message to the context; and more. A review of condolence letters written over modern history illustrates how these elements have been used over the past two millennia. As there is little relevant empirical research on the impact of engaging in the practice of writing condolence letters on well-being, further study is in order, particularly given the challenges of Covid-19. For now, the practice of writing condolence letters would appear to offer numerous and unexpected opportunities to give rise to positive outcomes associated with increased well-being. This, in turn, enriches the support for the coexistence of the negative and the positive in a life well-lived in the science of positive psychology

Clinical challenge: Deteriorating liver function in TB and HIV co-treatment

Editor’s note: In this section of the Journal, we present complex, real-world HIV medicine cases to two experienced clinicians working in very different environments, and ask them to describe the approach that they would take if they saw the case in their local hospital setting. In our first edition, a patient with deteriorating liver function is presented by Prof. Francois Venter and Dr Ntsakisi Masingi, and then discussed by Dr Sarah Stacey in Johannesburg and Dr Sarah Fidler in London

Narrow line width frequency comb source based on an injection-locked III–V-on-silicon mode-locked laser

In this paper, we report the optical injection locking of an L-band (similar to 1580 nm) 4.7 GHz III-V-on-silicon mode-locked laser with a narrow line width continuous wave (CW) source. This technique allows us to reduce the MHz optical line width of the mode-locked laser longitudinal modes down to the line width of the source used for injection locking, 50 kHz. We show that more than 50 laser lines generated by the mode-locked laser are coherent with the narrow line width CW source. Two locking techniques are explored. In a first approach a hybrid mode-locked laser is injection-locked with a CW source. In a second approach, light from a modulated CW source is injected in a passively mode-locked laser cavity. The realization of such a frequency comb on a chip enables transceivers for high spectral efficiency optical communication. (C) 2016 Optical Society of Americ

Predicting Dust Distribution in Protoplanetary Discs

We present the results of three-dimensional numerical simulations that include the effects of hydrodynamical forces and gas drag upon an evolving dusty gas disk. We briefly describe a new parallel, two phase numerical code based upon the smoothed particle hydrodynamics (SPH) technique in which the gas and dust phases are represented by two distinct types of particles. We use the code to follow the dynamical evolution of a population of grains in a gaseous protoplanetary disk in order to understand the distribution of grains of different sizes within the disk. Our ``grains'' range from metre to submillimetre in size.Comment: 2 pages, LaTeX with 1 ps figure embedded, using newpasp.sty (supplied). To appear in the proceedings of the XIXth IAP colloquium "Extrasolar Planets: Today and Tomorrow" held in Paris, France, 2003, June 30 -- July 4, ASP Conf. Se

Detecting Galaxy Tidal Features Using Self-Supervised Representation Learning

Low surface brightness substructures around galaxies, known as tidal features, are a valuable tool in the detection of past or ongoing galaxy mergers, and their properties can answer questions about the progenitor galaxies involved in the interactions. The assembly of current tidal feature samples is primarily achieved using visual classification, making it difficult to construct large samples and draw accurate and statistically robust conclusions about the galaxy evolution process. With upcoming large optical imaging surveys such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), predicted to observe billions of galaxies, it is imperative that we refine our methods of detecting and classifying samples of merging galaxies. This paper presents promising results from a self-supervised machine learning model, trained on data from the Ultradeep layer of the Hyper Suprime-Cam Subaru Strategic Program optical imaging survey, designed to automate the detection of tidal features. We find that self-supervised models are capable of detecting tidal features, and that our model outperforms previous automated tidal feature detection methods, including a fully supervised model. An earlier method achieved 76% completeness for 22% contamination, while our model achieves considerably higher (96%) completeness for the same level of contamination. We emphasise a number of advantages of self-supervised models over fully supervised models including maintaining excellent performance when using only 50 labelled examples for training, and the ability to perform similarity searches using a single example of a galaxy with tidal features.Comment: 11 pages, submitted to MNRAS. arXiv admin note: text overlap with arXiv:2307.0496

Detecting Tidal Features using Self-Supervised Representation Learning

Low surface brightness substructures around galaxies, known as tidal features, are a valuable tool in the detection of past or ongoing galaxy mergers. Their properties can answer questions about the progenitor galaxies involved in the interactions. This paper presents promising results from a self-supervised machine learning model, trained on data from the Ultradeep layer of the Hyper Suprime-Cam Subaru Strategic Program optical imaging survey, designed to automate the detection of tidal features. We find that self-supervised models are capable of detecting tidal features and that our model outperforms previous automated tidal feature detection methods, including a fully supervised model. The previous state of the art method achieved 76% completeness for 22% contamination, while our model achieves considerably higher (96%) completeness for the same level of contamination.Comment: Accepted at the ICML 2023 Workshop on Machine Learning for Astrophysic

Cultivating Connections at Philabundance

Philabundance is a Philadelphia-based food bank, serving the food insecure in nine counties in Pennsylvania and Southern New Jersey. Owing to its ambitious goal of not just relieving hunger, but ending it, a dispersed and diverse team working out of multiple sites and leadership turnover, issues with silos, morale and productivity have developed over recent years. Based on a situational analysis and a review of potentially applicable positive psychology research, Team Black believes that the organization could benefit from the positive psychology theories and research relating to (1) positive emotions and positivity resonance, (2) character strengths, and (3) meaning and mattering. Team Black has suggested a menu of positive interventions that would serve to bring these theories to life at Philabundance, to be introduced based on a timing that will depend on operational feasibility, particularly given the Covid-19 crisis. It is hoped that these interventions, all cultivating more connections at the organization, will not only help Philabundance to weather the crisis, but to cultivate connections among individuals, team and the organization as a whole, and ultimately increase well-being for all

Quantifying sudden changes in dynamical systems using symbolic networks

We characterise the evolution of a dynamical system by combining two well-known complex systems' tools, namely, symbolic ordinal analysis and networks. From the ordinal representation of a time-series we construct a network in which every node weights represents the probability of an ordinal patterns (OPs) to appear in the symbolic sequence and each edges weight represents the probability of transitions between two consecutive OPs. Several network-based diagnostics are then proposed to characterize the dynamics of different systems: logistic, tent and circle maps. We show that these diagnostics are able to capture changes produced in the dynamics as a control parameter is varied. We also apply our new measures to empirical data from semiconductor lasers and show that they are able to anticipate the polarization switchings, thus providing early warning signals of abrupt transitions.Comment: 18 pages, 9 figures, to appear in New Journal of Physic

The stellar mass - size relation for cluster galaxies at z=1 with high angular resolution from the Gemini/GeMS multi-conjugate adaptive optics system

We present the stellar mass - size relation for 49 galaxies within the $z$ = 1.067 cluster SPT-CL J0546$-$5345, with FWHM $\sim$80-120 mas $K_{\mathrm s}$-band data from the Gemini multi-conjugate adaptive optics system (GeMS/GSAOI). This is the first such measurement in a cluster environment, performed at sub-kpc resolution at rest-frame wavelengths dominated by the light of the underlying old stellar populations. The observed stellar mass - size relation is offset from the local relation by 0.21 dex, corresponding to a size evolution proportional to $(1+z)^{-1.25}$, consistent with the literature. The slope of the stellar mass - size relation $\beta$ = 0.74 $\pm$ 0.06, consistent with the local relation. The absence of slope evolution indicates that the amount of size growth is constant with stellar mass. This suggests that galaxies in massive clusters such as SPT-CL J0546$-$5345 grow via processes that increase the size without significant morphological interference, such as minor mergers and/or adiabatic expansion. The slope of the cluster stellar mass - size relation is significantly shallower if measured in $HST$/ACS imaging at wavelengths blueward of the Balmer break, similar to rest-frame UV relations at $z$ = 1 in the literature. The stellar mass - size relation must be measured at redder wavelengths, which are more sensitive to the old stellar population that dominates the stellar mass of the galaxies. The slope is unchanged when GeMS $K_s$-band imaging is degraded to the resolution of $K$-band HST/NICMOS resolution but dramatically affected when degraded to $K_s$-band Magellan/FourStar resolution. Such measurements must be made with AO in order to accurately characterise the sizes of compact, $z$ = 1 galaxies.Comment: 24 pages, 13 figures, 3 tables. Accepted for publication in MNRAS. Typos corrected, DOI adde

Society and analogy : notes on the contribution of Louis de Bonald to political theology

Among the counter-revolutionary figures who emerged after the French Revolution, the figure and works of Louis de Bonald (1754-1840), unlike those of Joseph de Maistre, remain shrouded in obscurity. Yet, he was in his own time recognised as the foremost critique of the excesses of the revolutionary period. His attempt at articulating a traditionalist philosophy of society and authority deserve to be better known among scholars if only because of the originality of his doctrine of the primitive revelation, which seeks to give an account of human knowledge based upon a particular understanding of human reason, and of the nature and function of language. His works also contain most invaluable insights about the ways in which societies are constituted, through a trifunctional and tripersonal understanding of the structure of social hierarchy. From his engagement on the questions of relations of the religious and the political, Louis de Bonald’s works seems ideally framed for providing a fresh perspective to the study of political theology. The acknowledged indebtedness of some of the modern proponents of political theology, e.g., Carl Schmitt, is sufficient a motive for attempting a delineation of the main features of Bonald’s political, social and epistemological doctrines in the light of an analogy of social forms. However, Bonald’s vindication of the traditional social and customary institutions is also to be complemented by a commitment for a jusnaturalist understanding of the dignity, freedom and rights of human beings as put forward by the luminaries of the Aristotelean-Thomist school, namely Jacques Maritain and Charles Journet. The present attempt at redefining political theology, in the light of Bonald’s thought, regards the social as a fundamental category of being. It is from the perspective of the permanence of society, in its immutable structure and logic of self-conservation, that man’s social nature can be properly understood