Role of resonances in rho^0 -> pi^+ pi^- gamma

We study the effect of the sigma(600) and a_1(1260) resonances in the rho^0 -> pi^+ pi^- gamma decay, within the meson dominance model. Major effects are driven by the mass and width parameters of the sigma(600), and the usually neglected contribution of the a_1(1260), although small by itself, may become sizable through its interference with pion bremsstrahlung, and the proper relative sign can favor the central value of the experimental branching ratio. We present a procedure, using the gauge invariant structure of the resonant amplitudes, to kinematically enhance the resonant effects in the angular and energy distribution of the photon. We also elaborate on the coupling constants involved.Comment: 5 pages, 5 figures, accepted for publication in PR

Market dynamics associated with credit ratings: a literature review.

Credit ratings produced by the major credit rating agencies (CRAs) aim to measure the creditworthiness, or more specifically the relative creditworthiness of companies, i.e. their ability to meet their debt servicing obligations. In principle, the rating process focuses on the fundamental long-term credit strength of a company. It is typically based on both public and private information, except for unsolicited ratings, which focus only on public information. The basic rationale for using ratings is to achieve information economies of scale and solve principal-agent problems. Partly for the same reasons, the role of credit ratings has expanded significantly over time. Regulators, banks and bondholders, pension fund trustees and other fiduciary agents have increasingly used ratings-based criteria to constrain behaviour. As a result, the influence of the opinions of CRAs on markets appears to have grown considerably in recent years. One aspect of this development is its potential impact on market dynamics (i.e. the timing and path of asset price adjustments, credit spreads, etc.), either directly, as a consequence of the information content of ratings themselves, or indirectly, as a consequence of the “hardwiring” of ratings into regulatory rules, fund management mandates, bond covenants, etc. When considering the impact of ratings and rating changes, two conclusions are worth highlighting. – First, ratings correlate moderately well with observed credit spreads, and rating changes with changes in spreads. However, other factors, such as liquidity, taxation and historical volatility clearly also enter into the determination of spreads. Recent research suggests that reactions to rating changes may also extend beyond the immediately-affected company to its peers, and from bond to equity prices. Furthermore, this price reaction to rating changes seems to be asymmetrical, i.e. more pronounced for downgrades than for upgrades, and may be more significant for equity prices than for bond prices. – Second, the hardwiring of regulatory and market rules, bond covenants, investment guidelines, etc., to ratings may influence market dynamics, and potentially lead to or magnify threshold effects. The more that different market participants adopt identical ratings-linked rules, or are subject to similar ratings-linked regulations, the more “spiky” the reaction to a credit event is likely to be. This reaction may include, in some cases, the emergence of severe liquidity pressures. Efforts have recently been made, notably with support from the rating agencies themselves, to encourage a more systematic disclosure of rating triggers and to renegotiate and smooth the possibly more destabilising forms of rating triggers. However, the lack of a clear disclosure regime makes it difficult to assess how far this process has evolved. Questions also remain as to the extent to which ratings-based criteria introduce a fundamentally new element into market behaviour, or, conversely, the extent to which they are simply a va riant of more traditional contractual covenants. Rating agencies strive to provide credit assessments that remain broadly stable through the course of the business cycle (rating “through the cycle”). Agencies and other analysts frequently contrast the fundamental credit analysis on which ratings are based with market sentiment — measured for example by bond spreads — which is arguably subject to more short-term influences. Agencies are adamant that they do not directly incorporate market sentiment into ratings (although they may use market prices as a diagnostic tool). On the contrary, they make every effort to exclude transient market sentiment. However, as reliance on ratings grows, CRAs are being increasingly expected to satisfy a widening range of constituencies, with different, and even sometimes conflicting, interests: issuers and “traditional” asset managers will look for more than a simple statement of near-term probability of loss, and will stress the need for ratings to exhibit some degree of stability over time. On the other hand, mark-to-market traders, active investors and risk managers may seek more frequent indications of credit changes. Hence, in the wake of major bankruptcies with heightened credit stress, rating agencies have been under considerable pressure to provide higher-frequency readings of credit status, without loss of quality. So far, they have responded to this challenge largely by adding more products to their traditional range, but also through modifications in the rating process. The rating process and the range of products offered by rating agencies have thus evolved over time, with, for instance, an increasing emphasis on the analysis of liquidity risks, a new focus on the hidden liabilities of companies and an increased use of market-based tools. It is too early, however, to judge whether these changes should simply be regarded as a refinement of the agencies’ traditional methodology or whether they suggest a more fundamental shift in the approach to credit risk measurement. For the same reason, it is not possible to draw any firm conclusions about changes in the effects of credit ratings on market dynamics.

Gestão do conhecimento em uma estrutura organizacional em rede

Partnership’s relations are more common among the organizations, creating structures in network and, in this context, the knowledge management is an important activity to the companies of providing services to improve the process of the customers. The purpose of this article is to examine the social and technical aspects of a structure in network to facilitate knowledge management and the continuous improvement activities in a real case. The firm searched implemented a structure constituted by "full service sites” that perform routine and improvement activities in full-time in the customers, as well as "centers of excellence", which assist in the process of knowledge management. To achieve this goal, a qualitative search was conducted in this company, based on exploratory case study. The research indicates that knowledge flow between individuals and also between different sites is enhanced because of the interactions in network, increasing the potential for improvement actions in the organization

Soluble HLA measurement in saliva and cerebrospinal fluid in Caucasian patients with multiple sclerosis: a preliminary study

BACKGROUND: Measurement of soluble HLA in body fluids has a potential role in assessing disease activity in autoimmune disorders. METHODS: We applied a solid phase, enzyme-linked immunoassay to measure soluble HLA class I (sHLA-I) and class II (sHLA-II) molecules in the saliva and cerebrospinal fluid (CSF) in 13 untreated patients with relapsing-remitting form of multiple sclerosis (MS). For comparison purposes, we also studied saliva from 53 healthy subjects. RESULTS: Saliva from normal controls had detectable sHLA-I levels in 41 of 53 individuals studied, with values ranging from 9–100 ng/ml (mean = 41 ± 2.8 ng/ml). sHLA-I was undetectable in the saliva in 11 of 13 MS patients, and in none of the CSF specimens. In contrast, mean sHLA-II concentration in the saliva of MS patients was significantly increased compared to controls (386 ± 52 unit/ml vs. 222 ± 18.4 unit/ml, t = 8.68, P < 0.005). The mean CSF sHLA-II level (369 ± 16 unit/ml) was equivalent to the mean sHLA-II concentration measured in saliva (mean = 386 ± 52 unit/ml) (P = 0.7). In patients with brain magnetic resonance imaging (MRI) enhancing lesions (n = 5), reflective of more active disease, CSF sHLA-II averaged 356 ± 26 unit/ml compared to 380 ± 51 in saliva. Similarly, in patients with non-enhancing lesions (n = 8), CSF sHLA-II averaged 377 ± 18 unit/ml compared to 390 ± 77 unit/ml in saliva. Thus, the mean sHLA-II concentration in saliva and CSF was essentially equivalent for MS patients with or without enhancing plaques. CONCLUSION: Our data suggest that the measurement of soluble HLA in saliva, specifically sHLA-II, correlates with the level found in the CSF. Therefore, if sHLA correlates with disease activity in MS, as has been proposed, saliva measurements provide a noninvasive correlate of CSF measurement

“DELTA DE CO2 Y SU ASOCIACIÓN CON EL CHOQUE HIPOVOLÉMICO HEMORRÁGICO GRADO III/IV POSTQUIRÚRGICO EN PACIENTES INGRESADOS AL SERVICIO DE TERAPIA INTENSIVA DEL CENTRO MÉDICO ISSEMYM TOLUCA, EN EL PERIODO COMPRENDIDO DE ENERO DEL 2013 A JUNIO DEL 2016”.

RESUMEN Introducción: El delta CO2 es considerado un marcador útil para la evaluación de la hipoperfusión tisular temprana en el estado de choque, desconociéndose su asociación en el choque hipovolémico hemorrágico postquirúrgico. Material y métodos: Se realizó un estudio observacional, analítico, longitudinal y retrolectivo, en pacientes con choque hipovólemico hemorrágico grado III/IV ingresados al servicio de Terapia Intensiva del Centro Médico ISSEMYM Toluca, de enero del 2013 a junio del 2016, en el postquirúrgico inmediato. Divididos según el delta CO2 al ingreso, 6 mmHg, determinando su evolución a las 24hrs. Resultados: De 49 pacientes, 28 cursaron con delta CO2 6 mmHg. Choque hipovolémico grado III en el 36% en el grupo 1, 43% en el grupo 2, p=0.612; grado IV con 64% en el grupo 1 y 57% en el grupo 2, p=0.612. Delta SOFA del 17.8% en el grupo 1 y 19.0% en el grupo 2. Asociación delta delta CO2 y delta SOFA, con p=0.62. Días de estancia en UCI, 4.5 (1 – 46) días en el grupo 1 y 6 días para el grupo dos (2 -149 días). Conclusión:Existe una tendencia positiva entre el delta delta CO2 y el delta SOFA, así como el tiempo de estancia hospitalaria en UCI asociado a delta CO2 > 6mmHg, por lo que se deberá de valorar nuevos estudios de tipo prospectivo

Effect of heating rate on gas emissions and properties of fired clay bricks and fired clay bricks incorporated with cigarette butts

In general, the firing process of clay bricks generates a range of gas emissions into the atmosphere. At high concentrations, these volatile emissions can be a serious source of environmental pollutions. The main purpose of this study was to evaluate the effect of different heating rates on gas emissions and properties during the firing of clay bricks and clay bricks incorporated with cigarette butts (CBs). In this investigation, four different heating rates were used: 0.7 °C min−1−1, 2 °C min−1, 5 °C min−1 and 10 °C min. The samples were fired in solid form from room temperature to 1050 °C. During the firing cycles, carbon monoxide, carbon dioxide, nitrogen oxides,hydrogen cyanide and chlorine emissions were measured at different heating rates. All bricks were also tested for their physical and mechanical properties including dry density, compressive strength, tensile strength, water absorption and initial rate of absorption. Results show that gas emissions were reduced significantly with higher heating rates (10 °C min) followed by 5 °C min−1−1 and 2 °C min for both types of brick samples. Higher heating rates also decrease the compressive strength and tensile strength value but demonstrate an insignificant effect on the water absorption properties respectively. In conclusion, a higher heating rate is preferable in terms of decreasing gas emissions and it is also able to produce adequate physical and mechanical properties especially for the CB brick

Soil microbial communities respond to an environmental gradient of grazing intensity in south Patagonia Argentina

Soil microorganisms communities regulate key functions in terrestrial ecosystems and contributes to the formation of stable organic matter and hence climate change mitigation. The structure, diversity and activity of soil microbial communities are influenced by the quantity and quality of organic compounds entering soils through the contribution of their root exudates and plant litter, which the microorganisms use as a substrate for biosynthesis and energy source. However, grazing effect on the soil microorganisms showed variable results dependent on the ecosystem under study. One of the main challenges of this millennium is the sustainability of agricultural production, especially in fragile soils such as those present in Patagonia. Therefore, our objective was to evaluate the responses of microbial biomass carbon (MBC), soil basal respiration (SBR), the derived coefficients and the abundance of fungi and bacteria under contrasting long-term grazing intensities in an environmental gradient. The study was established in three ecological areas Mata Negra Thicket (MNT), Dry Magellanic Steppe (DMS) and Humid Magellanic Steppe (HMS) with two grazing intensities. Soil samples were taken over two years in different seasons (autumn, winter, spring and summer). Results showed that biotic and abiotic factors (temperature and precipitation), plant communities and soil characteristics modulated the microbial structure and function in ecological area. On the other hand, high grazing intensity decreased the MBC and microbial coefficient (qM). There was a seasonal and interannual dynamic in the MBC and the bacteria and fungal communities, attributed mainly to temperature and precipitation. The results indicated that the effect of grazing intensity in soil microbial communities depends largely on intrinsic characteristics of each ecological area defined by the environmental gradient.EEA Santa CruzFil: Toledo, Santiago. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Correa, Olga S. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos; ArgentinaFil: Gargaglione, Veronica Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Gonzalez Polo, Marina. Consejo Nacional de Investigaciones Cientificas y Tecnicas.Fil: Toledo, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gargaglione, Veronica Beatriz. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Gargaglione, Veronica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gonzalez Polo, Marina. Universidad Nacional del Comahue. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin