Employing 2D Projections for Fast Visual Exploration of Large Fiber Tracking Data

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hunting a light U(1)B gauge boson coupled to baryon number in collider experiments

We analyze several signals at HERA and the Tevatron of a light U(1)B gauge boson (γB) coupling to baryon number. We show that the study of the production of bb pairs at the (upgraded) Tevatron can exclude γB with masses (mB) in the range 40 ≲ mB ≲ 300 GeV for γB couplings (αB) greater than 2 × 10-2 (3 × 10-3). We also show that the HERA experiments cannot improve the present bounds on γB. Moreover, we demonstrate that the production at HERA and the Tevatron of di-jet events with large rapidity gaps between the jets cannot be explained by the existence of a light γB. © 1999 Published by Elsevier Science B.V. All rights reserved.

Diphoton signals for large extra dimensions at the Fermilab Tevatron and CERN LHC

We analyze the potentiality of hadron colliders to search for large extra dimensions via the production of photon pairs. The virtual exchange of Kaluza-Klein gravitons can significantly enhance this process provided the quantum gravity scale (MS) is in the TeV range. We studied in detail the subprocesses qq̄→γγ and gg → γγ taking into account the complete standard model and graviton contributions as well as the unitarity constraints. We show that the Fermilab Tevatron run II will be able to probe MS up to 1.5-1.9 TeV at 2σ level, while the CERN LHC can extend this search to 5.3-6.7 TeV, depending on the number of extra dimensions. ©2000 The American Physical Society.

Direct signals for large extra dimensions in the production of fermion pairs at linear colliders

We analyze the potential of the next generation of e+e- linear colliders to search for large extra dimensions via the production of fermion pairs in association with Kaluza-Klein gravitons (G), i.e., e+e- →ff̃G. This process leads to a final state exhibiting a significant amount of missing energy in addition to acoplanar lepton or jet pairs. We study in detail this reaction using the full tree level contributions due to the graviton emission and the standard model backgrounds. After choosing the cuts to enhance the signal, we show that a linear collider with a center-of-mass energy of 500 GeV will be able to probe quantum gravity scales from 0.96 (0.86) up to 4.1 (3.3) TeV at a 2 (5)σ level, depending on the number of extra dimensions. ©2001 The American Physical Society.

Managing large scale virtual environments using portals

This article describes a technique for Large Scale Virtual Environments (LSVEs) partitioning in hexagon cells and using portal in the cell interfaces to reduce the number of messages on the network and the complexity of the virtual world. These environments usually demand a high volume of data that must be sent only to those users who needs the information [Greenhalgh, Benford 1997].

Geotechnical and structural behavior of the railroad track in large-scale apparatus

This paper analyses the static and dynamic behavior of the railroad track model in laboratory. Measurements of stresses and strains on a large-scale railroad track apparatus were studied. The model includes: compacted soil, representing the final layers of platform, ballast layer, and ties (steel, wooden, and pre-stressed concrete). The soil and soil ballast interface were instrumented with pneumatic stress gauge. Settlement measurement device were positioned at the same levels as the load cells. Loads were applied by hydraulic actuators, statically and dynamically. After the prescribed number of load cycles, in pre-determined intervals, stresses and strains were measured. Observations indicate that stress and strain distributions, transmitted by wooden or steel ties, behave similarly. A more favorable behavior was observed with pre-stressed concrete mono block ties. Non-linear response was observed after a threshold numbers of cycles were surpassed, showing that the strain modulus increases with the numbers of cycles. © 2009 IOS Press.

Improving the accuracy of the optimum-path forest supervised classifier for large datasets

In this work, a new approach for supervised pattern recognition is presented which improves the learning algorithm of the Optimum-Path Forest classifier (OPF), centered on detection and elimination of outliers in the training set. Identification of outliers is based on a penalty computed for each sample in the training set from the corresponding number of imputable false positive and false negative classification of samples. This approach enhances the accuracy of OPF while still gaining in classification time, at the expense of a slight increase in training time. © 2010 Springer-Verlag.

Marine Protected Areas in Brazil: An ecological approach regarding the large marine ecosystems

The objective of this study was to address the importance of implementing Coastal and Marine Protected Areas in Brazil and to examine their distribution, based on the delimitation of Large Marine Ecosystems. Out of a total of 336 protected areas identified in Brazilian coastal and marine areas, the North Platform has the largest protected area, but the ecosystem with the largest number of protected area, predominantly sustainable areas, was the East Coast followed by the South Platform. One of the reasons the eastern coast of Brazil to have more protected areas is the fact that there is a largest amount of coral reefs. Additionally there was political opportunities for the creation of protected areas for sustainable use. The coastal region of Brazil has achieved the goal proposed by the Seventh Conference of the Parties to the Convention on Biological Diversity - 7, but only then through the category V of the International Union for Conservation of Nature, which is not the best efficient means of conserving resources. The goal for marine conservation shows only the area above the recommended under protection in North Platform. The Marine portion of the East Coast and the South Platform has few protected areas, regardless of category management. We consider the coastal region the range of 12 nautical miles from baselines determined in accordance with the United Nations Convention on the Law of the Sea. As for the number of strategies permitted by law and used for the conservation of coastal and marine systems, coastal systems show a higher number when compared with the marine system. We suggest that the Brazilian government should specify strategies for the protection of marine systems and expand the protected areas of all Large Marine Ecosystems. © 2013 Elsevier Ltd.

Search for physics beyond the standard model in events with τ leptons, jets, and large transverse momentum imbalance in pp collisions at √s = 7 TeV

A search for physics beyond the standard model is performed with events having one or more hadronically decaying τ leptons, highly energetic jets, and large transverse momentum imbalance. The data sample corresponds to an integrated luminosity of 4.98 fb-1 of proton-proton collisions at √ = 7 TeV collected with the CMS detector at the LHC in 2011. The number of observed events is consistent with predictions for standard model processes. Lower limits on the mass of the gluino in supersymmetric models are determined. © 2013 CERN for the benefit of the CMS collaboration.

Law of large numbers for certain cylinder flows

We construct new examples of cylinder flows, given by skew product extensions of irrational rotations on the circle, that are ergodic and rationally ergodic along a subsequence of iterates. In particular, they exhibit a law of large numbers. This is accomplished by explicitly calculating, for a subsequence of iterates, the number of visits to zero, and it is shown that such number has a Gaussian distribution.

The conservation of number and location of 18S sites indicates the relative stability of rDNA in species of Pentatomomorpha (Heteroptera)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Trends in planktonic copepod diversity in reservoirs and lotic stretches in a large river basin in South America

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Next-generation sequencing reveals large connected networks of intra-host HCV variants

Background: Next-generation sequencing (NGS) allows for sampling numerous viral variants from infected patients. This provides a novel opportunity to represent and study the mutational landscape of Hepatitis C Virus (HCV) within a single host.Results: Intra-host variants of the HCV E1/E2 region were extensively sampled from 58 chronically infected patients. After NGS error correction, the average number of reads and variants obtained from each sample were 3202 and 464, respectively. The distance between each pair of variants was calculated and networks were created for each patient, where each node is a variant and two nodes are connected by a link if the nucleotide distance between them is 1. The work focused on large components having > 5% of all reads, which in average account for 93.7% of all reads found in a patient. The distance between any two variants calculated over the component correlated strongly with nucleotide distances (r = 0.9499; p = 0.0001), a better correlation than the one obtained with Neighbour-Joining trees (r = 0.7624; p = 0.0001). In each patient, components were well separated, with the average distance between (6.53%) being 10 times greater than within each component (0.68%). The ratio of nonsynonymous to synonymous changes was calculated and some patients (6.9%) showed a mixture of networks under strong negative and positive selection. All components were robust to in silico stochastic sampling; even after randomly removing 85% of all reads, the largest connected component in the new subsample still involved 82.4% of remaining nodes. In vitro sampling showed that 93.02% of components present in the original sample were also found in experimental replicas, with 81.6% of reads found in both. When syringe-sharing transmission events were simulated, 91.2% of all simulated transmission events seeded all components present in the source.Conclusions: Most intra-host variants are organized into distinct single-mutation components that are: well separated from each other, represent genetic distances between viral variants, robust to sampling, reproducible and likely seeded during transmission events. Facilitated by NGS, large components offer a novel evolutionary framework for genetic analysis of intra-host viral populations and understanding transmission, immune escape and drug resistance.

Evolutionary History of the PER3 Variable Number of Tandem Repeats (VNTR): Idiosyncratic Aspect of Primate Molecular Circadian Clock

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Impact of patient training patterns on peritonitis rates in a large national cohort study

Background. Ideal training methods that could ensure best peritoneal dialysis (PD) outcome have not been defined in previous reports. The aim of the present study was to evaluate the impact of training characteristics on peritonitis rates in a large Brazilian cohort.Methods. Incident patients with valid data on training recruited in the Brazilian Peritoneal Dialysis Multicenter Study (BRAZPD II) from January 2008 to January 2011 were included. Peritonitis was diagnosed according to International Society for Peritoneal Dialysis guidelines; incidence rate of peritonitis (episodes/patient-months) and time to the first peritonitis were used as end points.Results. Two thousand two hundred and forty-three adult patients were included in the analysis: 59 +/- 16 years old, 51.8% female, 64.7% with <= 4 years of education. The median training time was 15 h (IQI 10-20 h). Patients were followed for a median of 11.2 months (range 3-36.5). The overall peritonitis rate was 0.29 per year at risk (1 episode/41 patient-months). The mean number of hours of training per day was 1.8 +/- 2.4. Less than 1 h of training/day was associated with higher incidence rate when compared with the intervals of 1-2 h/day (P = 0.03) and > 2 h/day (P = 0.02). Patients who received a cumulative training of > 15 h had significantly lower incidence of peritonitis compared with < 15 h (0.26 per year at risk versus 0.32 per year at risk, P = 0.01). The presence of a caregiver and the number of people trained were not significantly associated with peritonitis incidence rate. Training in the immediate 10 days after implantation of the catheter was associated with the highest peritonitis rate (0.32 per year), compared with training prior to catheter implantation (0.28 per year) or > 10 days after implantation (0.23 per year). More experienced centers had a lower risk for the first peritonitis (P = 0.003).Conclusions. This is the first study to analyze the association between training characteristics and outcomes in a large cohort of PD patients. Low training time (particularly < 15 h), smaller center size and the timing of training in relation to catheter implantation were associated with a higher incidence of peritonitis. These results support the recommendation of a minimum amount of training hours to reduce peritonitis incidence regardless of the number of hours trained per day.