The geometry of null rotation identifications

The geometry of flat spacetime modded out by a null rotation (boost+rotation) is analysed. When embedding this quotient spacetime in String/M-theory, it still preserves one half of the original supersymmetries. Its connection with the BTZ black hole, supersymmetric dilatonic waves and one possible resolution of its singularity in terms of nullbranes are also discussed.Comment: 1+18 pages, 5 figures. v2 references adde

"No, We're Not Culturally Ready for That Yet": Chilean heterosexual women's discourses on Lesbian and Gay parenting. "No, Todavía No Estamos Culturalmente Preparados para Eso": Discursos de Mujeres Heterosexuales Chilenas sobre la Parentalidad Lésbica y Gay

This study examined Chilean heterosexual women's discourses concerning lesbian and gay (LG) parenting following a social constructionist perspective. Data from a convenience sample of 15 first-year psychology female students attending an evening university program in Concepción, Chile, were collected through 3 focus groups. Findings through a thematic analysis indicated that the major concern participants reported was that children of same-gender couples would be discriminated, because of their parents’ sexual identity. A minority of participants expressed that having LG parents could disrupt a child's gender and sexual identity development. It is concluded that children in LG parented families are still regarded at best as potentially vulnerable to secondary prejudice and at worst at risk of gender and sexual identity disruption. It would be worthwhile training Chilean psychology students about the development of children of LG parents and also highlighting subtle and enacted forms of sexual stigma. Este estudio examinó los discursos de mujeres heterosexuales chilenas sobre la parentalidad lésbica y gay (LG), siguiendo una perspectiva construccionista social. Los datos de una muestra por conveniencia de 15 estudiantes mujeres de primer año de psicología que asistían a un programa universitario vespertino en Concepción, Chile, se recopilaron a través de 3 grupos focales. Los hallazgos del análisis temático indicaron que la principal preocupación que informaron las participantes fue que los/as niños/as de parejas del mismo género serían discriminados/as, debido a la identidad sexual de sus madres/padres. Una minoría de las participantes expresó que tener madres/padres del mismo género podría perturbar el desarrollo del género y la identidad sexual de un/a niño/a. Se concluye que, los/as niños/as en familias de madres lesbianas y padres gay todavía se consideran, en el mejor de los casos, como potencialmente vulnerables a los prejuicios secundarios y, en el peor, en riesgo de perturbación de la identidad sexual y de género. Sería beneficioso entrenar a estudiantes de psicología chilenos/as acerca de la parentalidad LG y también destacar formas sutiles y explícitas de estigma sexual

Sustainability Assessment of indicators for integrated water resources management

The scientific community strongly recommends the adoption of indicators for the evaluation and monitoring of progress towards sustainable development. Furthermore, international organizations consider that indicators are powerful decision-making tools. Nevertheless, the quality and reliability of the indicators depends on the application of adequate and appropriate criteria to assess them. The general objective of this study was to evaluate how indicators related to water use and management perform against a set of sustainability criteria. Our research identified 170 indicators related to water use and management. These indicators were assessed by an international panel of experts that evaluated whether they fulfil the four sustainability criteria: social, economic, environmental, and institutional. We employed an evaluation matrix that classified all indicators according to the DPSIR (Driving Forces, Pressures, States, Impacts and Responses) framework. A pilot study served to test and approve the research methodology before carrying out the full implementation. The findings of the study show that 24 indicators comply with the majority of the sustainability criteria; 59 indicators are bi-dimensional (meaning that they comply with two sustainability criteria); 86 are one-dimensional indicators (fulfilling just one of the four sustainability criteria) and one indicator do not fulfil any of the sustainability criteria.Postprint (author's final draft

Global Aspects of T-Duality, Gauged Sigma Models and T-Folds

The gauged sigma-model argument that string backgrounds related by T-dual give equivalent quantum theories is revisited, taking careful account of global considerations. The topological obstructions to gauging sigma-models give rise to obstructions to T-duality, but these are milder than those for gauging: it is possible to T-dualise a large class of sigma-models that cannot be gauged. For backgrounds that are torus fibrations, it is expected that T-duality can be applied fibrewise in the general case in which there are no globally-defined Killing vector fields, so that there is no isometry symmetry that can be gauged; the derivation of T-duality is extended to this case. The T-duality transformations are presented in terms of globally-defined quantities. The generalisation to non-geometric string backgrounds is discussed, the conditions for the T-dual background to be geometric found and the topology of T-folds analysed.Comment: Minor corrections and addition

Jobless Pandemic: Geography of Layoffs and Opportunity Zones

The Worker Adjustment and Retraining Notification (WARN) Act is a law designed to protect workers against employment losses. Employers are required to provide employees with a 60-day notice in the event of plant closings and mass layoffs. Under normal conditions, WARNs are required in the event of a) Plants closing or stopping operation either permanently or temporarily affecting 50 or more workers; b) Layoffs of 500 or more employees during a 30-day-period or when these layoffs constitute at least a third of the company’s workforce; and c) Temporary layoffs expected to exceed six months, in this case, when a temporary layoff originally not expected to exceed six months gets extended, it would trigger a WARN. This last scenario has been the case of many companies during the COVID-19 pandemic. In the event of “unforeseeable business circumstances,” businesses are not subject to the 60-day notice requirement, as was also the case of many COVID-19 related layoffs. When the stay-at-home orders caused a sudden loss of business outside of the employer’s control, the state of Ohio required that companies laying-off 50 or more employees due to lack of business must report the layoff within a 7-day period. Given this information, it should be noted that the nature of the WARNs does not allow a complete analysis of all the jobs lost in the region during the pandemic, as small businesses are not obligated to file a WARN and would not traditionally do so. Therefore, the following analysis does not reflect small- to medium-sized businesses. However, sizable layoffs are reflective of large regional employers whose layoffs might trigger considerable impacts in their supply chain. There were a total of 19,318 layoffs reported from companies in Northeast Ohio (NEO) between January and August of 2020, and 18,458 (96%) have occurred since March 19th, just a few days after the stay-at-home order was instated. Immediately after the stay-at-home order, companies began to state COVID-19 as one of the primary reasons behind their mass layoffs. 91% of the reported layoffs since March 19th have been attributed to the pandemic according to the companies’ own WARNs, for a total of 16,857 reported jobs lost. The months of March and April saw the most COVID-19 related layoffs with 6,190 affected, while April saw 5,129 layoffs. Following these huge losses, the numbers dropped to below 2,000, and during the month of August, only 309 lost jobs were reported, which may be a sign of a beginning stabilization in the region

A multiscale hybrid mathematical model of epidermal-dermal interactions during skin wound healing.

Following injury, skin activates a complex wound healing programme. While cellular and signalling mechanisms of wound repair have been extensively studied, the principles of epidermal-dermal interactions and their effects on wound healing outcomes are only partially understood. To gain new insight into the effects of epidermal-dermal interactions, we developed a multiscale, hybrid mathematical model of skin wound healing. The model takes into consideration interactions between epidermis and dermis across the basement membrane via diffusible signals, defined as activator and inhibitor. Simulations revealed that epidermal-dermal interactions are critical for proper extracellular matrix deposition in the dermis, suggesting these signals may influence how wound scars form. Our model makes several theoretical predictions. First, basal levels of epidermal activator and inhibitor help to maintain dermis in a steady state, whereas their absence results in a raised, scar-like dermal phenotype. Second, wound-triggered increase in activator and inhibitor production by basal epidermal cells, coupled with fast re-epithelialization kinetics, reduces dermal scar size. Third, high-density fibrin clot leads to a raised, hypertrophic scar phenotype, whereas low-density fibrin clot leads to a hypotrophic phenotype. Fourth, shallow wounds, compared to deep wounds, result in overall reduced scarring. Taken together, our model predicts the important role of signalling across dermal-epidermal interface and the effect of fibrin clot density and wound geometry on scar formation. This hybrid modelling approach may be also applicable to other complex tissue systems, enabling the simulation of dynamic processes, otherwise computationally prohibitive with fully discrete models due to a large number of variables

Navigating Government Statistics of Small Businesses for Pandemic Assistance

This brief examines various sources of government statistics to assist in understanding the scope of small businesses, the legal structure of their operations, and their distribution by industry in the Northeast Ohio (NEO) region. Under the current restrictions for business operations due to the COVID-19 pandemic, many entrepreneurs and small businesses need assistance to maintain cash flow and to retain both their employees and customers. Governments at all levels have developed business assistance programs to help small businesses; more recently, some of these programs have revised their rules. To illustrate who might be affected by the changing rules, several sources of government statistics can be used to define how many companies operate as a small business in the region. Entrepreneurs and small businesses play a crucial role in the regional economy, and for a successful recovery, it is imperative that small businesses and entrepreneurs stay afloat during this pivotal period

Composite fluxbranes with general intersections

Generalized composite fluxbrane solutions for a wide class of intersection rules are obtained. The solutions are defined on a manifold which contains a product of n Ricci-flat spaces M_1 x ... x M_n with 1-dimensional M_1. They are defined up to a set of functions H_s obeying non-linear differential equations equivalent to Toda-type equations with certain boundary conditions imposed. A conjecture on polynomial structure of governing functions H_s for intersections related to semisimple Lie algebras is suggested. This conjecture is valid for Lie algebras: A_m, C_{m+1}, m > 0. For simple Lie algebras the powers of polynomials coincide with the components of the dual Weyl vector in the basis of simple roots. Explicit formulas for A_1 + ... + A_1 (orthogonal), "block-ortogonal" and A_2 solutions are obtained. Certain examples of solutions in D = 11 and D =10 (II A) supergravities (e.g. with A_2 intersection rules) and Kaluza-Klein dyonic A_2 flux tube, are considered.Comment: 19 pages, Latex, 1 reference (on a pioneering paper of Gibbons and Wiltshire) and two missing relations are added Published: Class. Quantum Grav. 19 (2002) 3033-304

Birkhoff's Theorem for Three-Dimensional AdS Gravity

All three-dimensional matter-free spacetimes with negative cosmological constant, compatible with cyclic symmetry are identified. The only cyclic solutions are the 2+1 (BTZ) black hole with SO(2) x R isometry, and the self-dual Coussaert-Henneaux spacetimes, with isometry groups SO(2) x SO(2,1) or SO(2) x SO(2).Comment: 11 pages, RevTeX4; minor typos corrected, Ref. added, accepted for publication in Phys. Rev.