Building the Brazilian Academic Genealogy Tree

Along the history, many researchers provided remarkable contributions to science, not only advancing knowledge but also in terms of mentoring new scientists. Currently, identifying and studying the formation of researchers over the years is a challenging task as current repositories of theses and dissertations are cataloged in a decentralized way through many local digital libraries. Following our previous work in which we created and analyzed a large collection of genealogy trees extracted from NDLTD, in this paper we focus our attention on building such trees for the Brazilian research community. For this, we use data from the Lattes Platform, an internationally renowned initiative from CNPq, the Brazilian National Council for Scientific and Technological Development, for managing information about individual researchers and research groups in Brazil

Revealing the impacts of passive cooling techniques on building energy performance: A residential case in Hong Kong

Environmental concerns and growing energy costs raise the importance of sustainable development and energy conservation. The building sector accounts for a significant portion of total energy consumption. Passive cooling techniques provide a promising and cost-efficient solution to reducing the energy demand of buildings. Based on a typical residential case in Hong Kong, this study aims to analyze the integration of various passive cooling techniques on annual and hourly building energy demand with whole building simulation. The results indicate that infiltration and insulation improvement are effective in regard to energy conservation in buildings, while the effectiveness of variations in building orientation, increasing natural ventilation rate, and phase change materials (PCM) are less significant. The findings will be helpful in the passive house standard development in Hong Kong and contribute to the further optimization work to realize both energy efficiency and favorably built environments in residential buildings.</jats:p

Deciphering interplay between Salmonella invasion effectors

Bacterial pathogens have evolved a specialized type III secretion system (T3SS) to translocate virulence effector proteins directly into eukaryotic target cells. Salmonellae deploy effectors that trigger localized actin reorganization to force their own entry into non-phagocytic host cells. Six effectors (SipC, SipA, SopE/2, SopB, SptP) can individually manipulate actin dynamics at the plasma membrane, which acts as a ‘signaling hub’ during Salmonella invasion. The extent of crosstalk between these spatially coincident effectors remains unknown. Here we describe trans and cis binary entry effector interplay (BENEFIT) screens that systematically examine functional associations between effectors following their delivery into the host cell. The results reveal extensive ordered synergistic and antagonistic relationships and their relative potency, and illuminate an unexpectedly sophisticated signaling network evolved through longstanding pathogen–host interaction

Surgical outcomes of patients with neuroblastoma in a tertiary centre in Hong Kong: A 12-year experience

Introduction: Neuroblastoma has a heterogeneous clinical course. The prognosis varies widely depending on the age of diagnosis, extent of disease and tumour biology. However, the specific clinical outcome of this disease in Hong Kong has not been well characterised thus far. Complete tumour excision has been demonstrated to confer survival benefit on patients with advanced disease even if there is metastasis. Since year 2004, we have adopted a revised, more aggressive surgical approach in managing these patients. Here, we aim to review our experience in the management of this disease. Methods: A retrospective review was performed for the past 12 years to include all patients who presented with neuroblastoma in our institution. Data such as the survival, age at diagnosis, MYCN amplification status, the extent of tumour excision, and stage of the disease were recorded and analysed. Results: 37 patients were included in this study. Overall survival of our patients was 67.6%. Patients with Stage 1, 2 and 4S have 100% survival whereas stage 4 patients only have 41.4% survival. Since our revised surgical approach in 2004, patients who had been operated had a better survival. Survival of stage 4 patients with operation after 2004 was 57.1% whereas the survival of patients at the same stage before 2004 was only 30%. Age at diagnosis, completeness of tumour excision and stage of disease are also correlated with overall prognosis. Further, patients with the presence of MYCN gene amplification have apparently poorer survival but it is not statistically significant due to the small sample size. Conclusion: The management of patients with neuroblastoma remains a challenge. Advanced stage of disease, incomplete tumour excision and increased age at diagnosis were all associated with poor survival. We demonstrated a better survival for those who underwent a more aggressive surgical approach, though this is a technically demanding and time consuming procedure. Thus, the management of advanced neuroblastoma should be centralised in a centre with combined surgical, oncological and paediatric intensive care expertise.published_or_final_versio

Goldstone Bosons in Effective Theories with Spontaneously Broken Flavour Symmetry

The Flavour Symmetry of the Standard Model (SM) gauge sector is broken by the fermion Yukawa couplings. Promoting the Yukawa matrices to scalar spurion fields, one can break the flavour symmetry spontaneously by giving appropriate vacuum expectation values (VEVs) to the spurion fields, and one encounters Goldstone modes for every broken flavour symmetry generator. In this paper, we point out various aspects related to the possible dynamical interpretation of the Goldstone bosons: (i) In an effective-theory framework with local flavour symmetry, the Goldstone fields represent the longitudinal modes for massive gauge bosons. The spectrum of the latter follows the sequence of flavour-symmetry breaking related to the hierarchies in Yukawa couplings and flavour mixing angles. (ii) Gauge anomalies can be consistently treated by adding higher-dimensional operators. (iii) Leaving the U(1) factors of the flavour symmetry group as global symmetries, the respective Goldstone modes behave as axions which can be used to resolve the strong CP problem by a modified Peccei-Quinn mechanism. (iv) The dynamical picture of flavour symmetry breaking implies new sources of flavour-changing neutral currents, which arise from integrating out heavy scalar spurion fields and heavy gauge bosons. The coefficients of the effective operators follow the minimal-flavour violation principle.Comment: 27 pages, abstract and introduction extended, more detailed discussion of heavy gauge boson spectrum and auxiliary heavy fermions, outline restructured. Matches version to be published in JHE

Bounds for State Degeneracies in 2D Conformal Field Theory

In this note we explore the application of modular invariance in 2-dimensional CFT to derive universal bounds for quantities describing certain state degeneracies, such as the thermodynamic entropy, or the number of marginal operators. We show that the entropy at inverse temperature 2 pi satisfies a universal lower bound, and we enumerate the principal obstacles to deriving upper bounds on entropies or quantum mechanical degeneracies for fully general CFTs. We then restrict our attention to infrared stable CFT with moderately low central charge, in addition to the usual assumptions of modular invariance, unitarity and discrete operator spectrum. For CFT in the range c_left + c_right < 48 with no relevant operators, we are able to prove an upper bound on the thermodynamic entropy at inverse temperature 2 pi. Under the same conditions we also prove that a CFT can have a number of marginal deformations no greater than ((c_left + c_right) / (48 - c_left - c_right)) e^(4 Pi) - 2.Comment: 23 pages, LaTeX, minor change

Low-frequency cortical activity is a neuromodulatory target that tracks recovery after stroke.

Recent work has highlighted the importance of transient low-frequency oscillatory (LFO; &lt;4 Hz) activity in the healthy primary motor cortex during skilled upper-limb tasks. These brief bouts of oscillatory activity may establish the timing or sequencing of motor actions. Here, we show that LFOs track motor recovery post-stroke and can be a physiological target for neuromodulation. In rodents, we found that reach-related LFOs, as measured in both the local field potential and the related spiking activity, were diminished after stroke and that spontaneous recovery was closely correlated with their restoration in the perilesional cortex. Sensorimotor LFOs were also diminished in a human subject with chronic disability after stroke in contrast to two non-stroke subjects who demonstrated robust LFOs. Therapeutic delivery of electrical stimulation time-locked to the expected onset of LFOs was found to significantly improve skilled reaching in stroke animals. Together, our results suggest that restoration or modulation of cortical oscillatory dynamics is important for the recovery of upper-limb function and that they may serve as a novel target for clinical neuromodulation

Positron kinetics in an idealized PET environment

The kinetic theory of non-relativistic positrons in an idealized positron emission tomography PET environment is developed by solving the Boltzmann equation, allowing for coherent and incoherent elastic, inelastic, ionizing and annihilating collisions through positronium formation. An analytic expression is obtained for the positronium formation rate, as a function of distance from a spherical source, in terms of the solutions of the general kinetic eigenvalue problem. Numerical estimates of the positron range - a fundamental limitation on the accuracy of PET, are given for positrons in a model of liquid water, a surrogate for human tissue. Comparisons are made with the 'gas-phase' assumption used in current models in which coherent scattering is suppressed. Our results show that this assumption leads to an error of the order of a factor of approximately 2, emphasizing the need to accurately account for the structure of the medium in PET simulations

Theoretical Uncertainties in Electroweak Boson Production Cross Sections at 7, 10, and 14 TeV at the LHC

We present an updated study of the systematic errors in the measurements of the electroweak boson cross-sections at the LHC for various experimental cuts for a center of mass energy of 7, 10 and 14 TeV. The size of both electroweak and NNLO QCD contributions are estimated, together with the systematic error from the parton distributions. The effects of new versions of the MSTW, CTEQ, and NNPDF PDFs are considered.Comment: PDFLatex with JHEP3.cls. 22 pages, 43 figures. Version 2 adds the CT10W PDF set to analysis and updates the final systematic error table and conclusions, plus several citations and minor wording changes. Version 3 adds some references on electroweak and mixed QED/QCD corrections. Version 4 adds more references and acknowledgement