25,472 research outputs found
D Mesons in Nuclear Matter: A DN Coupled-Channel Equations Approach
A set of coupled two-body scattering equations is solved for the DN system
embedded in an iso-symmetric nuclear matter. The in-medium behavior of charmed
D mesons: (D^+,D^0), is investigated from the self-consistent solution within
this scheme. The effective meson-baryon Lagrangian in charm quantum number one
sector, the key ingredient in the present study, is adopted from a recent model
by Hofmann and Lutz which has aimed at combining the charmed meson degree of
freedom in a consistent manner with chiral unitary models. After a critical
examination, the original model is modified in several important aspects, such
as the method of regularization, in order to be more consistent and practical
for our objective. The resultant interaction is used to reproduce the position
and width of the s-wave \Lambda_c(2593) resonance in the isospin zero DN
channel. In the isospin one channel, it generates a rather wide resonance at
\~2770 MeV. The corresponding in-medium solution is then sought by
incorporating Pauli blocking and the D- and \pi-meson dressing
self-consistently. At normal nuclear matter density, the resultant \Lambda_c
(2593) is found to stay narrow and shifted at a lower energy, while the I=1
resonance is lowered in position as well and broadened considerably. The
possible implication of our findings on the J/\Psi suppression, etc. in
relativistic heavy ion collisions is briefly discussed.Comment: 30 pages, 8 eps figures, some typos and coefficients corrected,
published in Phys. Rev.
The structure of algebraic covariant derivative curvature tensors
We use the Nash embedding theorem to construct generators for the space of
algebraic covariant derivative curvature tensors
Convex Independence in Permutation Graphs
A set C of vertices of a graph is P_3-convex if every vertex outside C has at
most one neighbor in C. The convex hull \sigma(A) of a set A is the smallest
P_3-convex set that contains A. A set M is convexly independent if for every
vertex x \in M, x \notin \sigma(M-x). We show that the maximal number of
vertices that a convexly independent set in a permutation graph can have, can
be computed in polynomial time
Detection of Leishmania infantum by PCR, serology and cellular immune response in a cohort study of Brazilian dogs
The sensitivity and specificity of PCR, serology (ELISA) and lymphoproliferative response to Leishmania antigen for the detection of Leishmania infantum infection were evaluated in a cohort of 126 dogs exposed to natural infection in Brazil. For PCR, Leishmania DNA from bone-marrow was amplified with both minicircle and ribosomal primers. The infection status and time of infection of each dog were estimated from longitudinal data. The sensitivity of PCR in parasite-positive samples was 98%. However, the overall sensitivity of PCR in post-infection samples, from dogs with confirmed infection, was only 68%. The sensitivity of PCR varied during the course of infection, being highest (78–88%) 0–135 days post-infection and declining to around 50% after 300 days. The sensitivity of PCR also varied between dogs, and was highest in sick dogs. The sensitivity of serology was similar in parasite-positive (84%), PCR-positive (86%) and post-infection (88%) samples. The sensitivity of serology varied during the course of infection, being lowest at the time of infection and high (93–100%) thereafter. Problems in determining the specificity of serology are discussed. The sensitivity and specificity of cellular responsiveness were low. These data suggest that PCR is most useful in detecting active or symptomatic infection, and that serology can be a more sensitive technique for the detection of all infected dogs
ASEAN Way: desafíos, problemas y oportunidades durante la COVID-19
The COVID-19 pandemic brought tremendous change to everyone's lifestyle as well as the social, political, and economic landscape. This novel global health crisis has challenged every state's healthcare system regardless of being a highly developed, newly developed, or developing economy. The southeast Asian region has been one of the heavily hit regions in the world because of its proximity to China, where the virus originated and the vulnerability of their lesser developed healthcare systems. However, despite these challenges to public health governance, these South East Asian countries were able to come up with innovative, inclusive, and effective public health policies, programs, and strategies to address the pandemic. Using the Global Health Governance theory, the study looked into four (4) thematic areas: Actions of the Government, Actions of the Private Sector, Criticisms of the People, and the Effects on the Economy to further gauge the landscape of the effects of the pandemic to the region. The researcher concluded from these responses to mitigate the effects of the pandemic and their continuing efforts to balance public health and socio-economic development agenda.
Keywords: ASEAN; COVID-19 Pandemic; Health Governance; Public Health Governance.La COVID-19 trajo cambios tremendos en el estilo de vida de todos, así como en el panorama social, político y económico. Esta nueva crisis de salud global ha desafiado el sistema de salud de todos los estados, independientemente de que sean economías altamente desarrolladas, recientemente desarrolladas o en desarrollo. La región del sudeste asiático ha sido una de las regiones más afectadas del mundo debido a su proximidad a China, donde se originó el virus y la vulnerabilidad de sus sistemas de salud menos desarrollados. Sin embargo, a pesar de estos desafíos para la gobernanza de la salud pública, estos países del sudeste asiático pudieron idear políticas, programas y estrategias de salud pública innovadores, inclusivos y efectivos para abordar la pandemia. Usando la teoría de la Gobernanza de la Salud Global, el estudio analizó cuatro (4) áreas temáticas: Acciones del Gobierno, Acciones del Sector Privado, Críticas de la Gente y los Efectos en la Economía para evaluar aún más el panorama de los efectos de la pandemia a la región. Se concluyó que desde países en desarrollo hasta países avanzados, no se puede negar que COVID-19 ha afectado a personas de todo el mundo de una forma u otra. Dejó (y sigue dejando) impactos en los sectores de un país, desde su economía hasta los ajustes educativos.
Palabras clave: TASEAN; COVID-19; Gobernanza en Salud; Gobernanza de la Salud Pública
Evaluating a guest satisfaction model through data mining
Purpose: This paper aims to propose a data mining approach to evaluate a conceptual model in tourism, encompassing a large data set characterized by dimensions grounded on existing literature. Design/methodology/approach: The approach is tested using a guest satisfaction model encompassing nine dimensions. A large data set of 84 k online reviews and 31 features was collected from TripAdvisor. The review score granted was considered a proxy of guest satisfaction and was defined as the target feature to model. A sequence of data understanding and preparation tasks led to a tuned set of 60k reviews and 29 input features which were used for training the data mining model. Finally, the data-based sensitivity analysis was adopted to understand which dimensions most influence guest satisfaction. Findings: Previous user’s experience with the online platform, individual preferences, and hotel prestige were the most relevant dimensions concerning guests’ satisfaction. On the opposite, homogeneous characteristics among the Las Vegas hotels such as the hotel size were found of little relevance to satisfaction. Originality/value: This study intends to set a baseline for an easier adoption of data mining to evaluate conceptual models through a scalable approach, helping to bridge between theory and practice, especially relevant when dealing with Big Data sources such as the social media. Thus, the steps undertaken during the study are detailed to facilitate replication to other models.info:eu-repo/semantics/acceptedVersio
- …