Cutting edges at random in large recursive trees

We comment on old and new results related to the destruction of a random recursive tree (RRT), in which its edges are cut one after the other in a uniform random order. In particular, we study the number of steps needed to isolate or disconnect certain distinguished vertices when the size of the tree tends to infinity. New probabilistic explanations are given in terms of the so-called cut-tree and the tree of component sizes, which both encode different aspects of the destruction process. Finally, we establish the connection to Bernoulli bond percolation on large RRT's and present recent results on the cluster sizes in the supercritical regime.Comment: 29 pages, 3 figure

Solar Neutrinos: Status and Prospects

We describe the current status of solar neutrino measurements and of the theory -- both neutrino physics and solar astrophysics -- employed in interpreting measurements. Important recent developments include Super-Kamiokande's determination of the neutrino-electron elastic scattering rate for 8B neutrinos to 3%; the latest SNO global analysis in which the inclusion of low-energy data from SNO I and II significantly narrowed the range of allowed values for the neutrino mixing angle theta12; Borexino results for both the 7Be and pep neutrino fluxes, the first direct measurements constraining the rate of ppI and ppII burning in the Sun; global reanalyses of solar neutrino data that take into account new reactor results on theta13; a new decadal evaluation of the nuclear physics of the pp chain and CNO cycle defining best values and uncertainties in the nuclear microphysics input to solar models; recognition of an emerging discrepancy between two tests of solar metallicity, helioseismological mappings of the sound speed in the solar interior, and analyses of the metal photoabsorption lines based on our best current description of the Sun's photosphere; a new round of standard solar model calculations optimized to agree either with helioseismology or with the new photospheric analysis; and, motivated by the solar abundance problem, the development of nonstandard, accreting solar models, in order to investigate possible consequences of the metal segregation that occurred in the proto-solar disk. We review this progress and describe how new experiments such as SNO+ could help us further exploit neutrinos as a unique probe of stellar interiors.Comment: 82 pages, 11 figure

Schizoaffective disorder. How much belongs to schizophrenia? How much belongs to bipolar disorder?

Indexación: Web of Science; ScieloIntroducción: El Trastorno Esquizoafectivo constituye un área de controversias respecto a su nosología y criterios para su clasificación. Ha sido considerado como una variante de la Esquizofrenia, un cuadro mixto en el cual coexisten la Esquizofrenia y el Trastorno Bipolar y como un subtipo del Trastorno Bipolar. Método: Se revisan aspectos diagnósticos, clasificatorios y características psicopatológicas del trastorno en su concepción actual y aportes desde la perspectiva de la investigación neuropsicológica y la genética. Discusión y Conclusiones: El concepto actual de Trastorno Esquizoafectivo, difiere de su descripción original manteniéndose la falta de claridad definitiva respecto a su nosología. Tomando en consideración las alteraciones neurocognitivas que acompañan su evolución, el Trastorno Esquizoafectivo guardaría una mayor afinidad con las psicosis afectivas que con la Esquizofrenia. Desde la investigación genética surgen datos que cuestionan la distinción dicotómica clásica entre las psicosis afectivas y la Esquizofrenia establecida por E. Kraepelin, replanteándose la formulación de la psicosis en un continuum del cual el Trastorno Esquizoafectivo podría representar un estadio intermedio.Introduction: Schizoaffective Disorder represents a controversial clinical entity, in regard to nosology and classification criteria. It has been considered as a variant of Schizophrenia, as a mixed entity between Schizophrenia and Bipolar Disorder and as a Bipolar Disorder subtype Method: Classificatory, clinical issues, neuropsychology and genetics research contributions are reviewed. Discussion and Conclusion: Schizoaffective Disorder concept at present time, differs from its original description, maintaining lack of definitive clarity with respect to its nosology. Considering neurocognitive impairment within its course, Schizoaffective Disorder looks much closer to affective psychosis than to Schizophrenia. From genetic research field emerges data that challenge the classic dichotomist distinction between affective psychosis and Schizophrenia established by E. Kraepelin, raising again the question about thinking in psychosis as a continuum in which Schizoaffective Disorder could represent an intermediate state.http://ref.scielo.org/4rww3

A Systematic Literature Review of the Humanistic Burden of COPD

Background: Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide, causing substantial economic and social burden. Objective: This review assessed the patient-reported humanistic burden associated with moderate to very severe COPD, specifically the impact on health-related quality of life (HRQoL), symptoms, limitations in daily life, and emotional implications, through the use of HRQoL instruments. Methods: A systematic review was conducted to retrieve relevant clinical data from published literature using a representative sample of countries where healthcare systems provide wide availability of COPD medications and/or universal coverage includes respiratory medicines (Australia, Canada, China, France, Germany, Italy, Spain, the UK, and the USA). The primary inclusion criteria were patients with moderate to very severe COPD. HRQoL was quantified with non-disease-specific and disease-specific questionnaires. Results: In total, 82 studies from 95 publications presented HRQoL data from patients with moderate to very severe COPD. Patient-reported HRQoL declined with worsening airflow limitation, advancing GOLD group, and increasing exacerbation frequency. Both increasing frequency of hospitalization for COPD exacerbations and recurrent hospitalization adversely impacted HRQoL. Comorbidity incidence was higher in patients with increased airflow limitation. It was associated with a further decline in HRQoL and increased depression and anxiety, particularly as disease-associated pain worsened. Physical activity improved HRQoL over time. Conclusion: This review highlighted the impact of exacerbations and associated hospitalizations on the humanistic burden of COPD. These findings underline the importance of managing COPD actively, including prompt and appropriate use of pharmacological and non-pharmacological therapies that can improve symptoms and reduce the risk of exacerbations, thereby lessening the humanistic burden. Future reviews could consider a broader range of countries and publications to further assess the humanistic impact of COPD in low- and middle-income economies

Pure-radiation gravitational fields with a simple twist and a Killing vector

Pure-radiation solutions are found, exploiting the analogy with the Euler- Darboux equation for aligned colliding plane waves and the Euler-Tricomi equation in hydrodynamics of two-dimensional flow. They do not depend on one of the spacelike coordinates and comprise the Hauser solution as a special subcase.Comment: revtex, 9 page

Localization of thioredoxin in the rat brain and functional implications

The immunoreactivity for thioredoxin, which catalyzes protein disulfide reductions, has previously been shown to exist in nerve cells and their axons. Here we demonstrate the localization of thioredoxin mRNA as revealed by in situ hybridization in the rat brain. The gene is expressed in nerve cells of a variety of brain regions, for example, the cerebral cortex, the piriform cortex, the medial preoptic area, the CA3/CA4 region of the hippocampal formation, the dentate gyrus, the paraventricular nucleus of the hypothalamus, the arcuate nucleus, the substantia nigra pars compacta, the locus coeruleus, the ependyma of the 4th ventricle, and the epithelial cells of the choroid plexus. This distribution implicates an important function in nerve cell metabolism, especially in regions with high energy demands and indicates a role of the choroid plexus in nerve cell protection from environmental influences. It was found that after mechanical injury induced by partial unilateral hemitransection the thioredoxin mRNA expression is upregulated in the lesioned area and spreads to the cortical hemispheres at the lesioned level. This induction suggests a function of thioredoxin in the regeneration machinery of the brain following mechanical injury and oxidative stress