A soft‐cache strategy for pathologist's navigation in virtual microscopy

Navigation through large microscopical images demands special characteristics like flexibility to access image data and progressive recovery or relevant information, i.e., several qualities, magnifications, and random accesses to any desired Window of Interest in the Virtual Slide (VS). Nowadays there exist systems that allow such interaction, but with a certain delay, which is dependent on the application. It has been shown that caching or prefetching policies can speed up interaction with these systems. This article presents an optimal soft‐cache strategy, which improves the navigation times in virtual microscopy. The entire method includes an optimal soft‐cache strategy and a dynamical probabilistic model of a pathologist's navigation. This strategy was implemented as a Client‐Server application, using the JPEG2000‐JPIP standard and evaluated using different navigation patterns, namely, four different pathologists exploring 10 VS, stained with different dyes. The present approach was compared with a conventional soft‐cache method and the cache performance improved, in average, in about a 10%. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.     

Bioactive glass scaffolds for bone tissue engineering: state of the art and future perspectives

The repair and regeneration of large bone defects resulting from disease or trauma remains a significant clinical challenge. Bioactive glass has appealing characteristics as a scaffold material for bone tissue engineering, but the application of glass scaffolds for the repair of load-bearing bone defects is often limited by their low mechanical strength and fracture toughness. This paper provides an overview of recent developments in the fabrication and mechanical properties of bioactive glass scaffolds. The review reveals the fact that mechanical strength is not a real limiting factor in the use of bioactive glass scaffolds for bone repair, an observation not often recognized by most researchers and clinicians. Scaffolds with compressive strengths comparable to those of trabecular and cortical bones have been produced by a variety of methods. The current limitations of bioactive glass scaffolds include their low fracture toughness (low resistance to fracture) and limited mechanical reliability, which have so far received little attention. Future research directions should include the development of strong and tough bioactive glass scaffolds, and their evaluation in unloaded and load-bearing bone defects in animal models.     

Graphene Devices: Structured Graphene Devices for Mass Transport (Small 6/2011)

The reversible atomic‐mass transport along graphene devices has been achieved. The motion of Al and Au in the form of atoms or clusters is driven by applying an electric field between the metal electrodes that contact the graphene sheet. It is shown that Al moves in the direction of the applied electric field whereas Au tends to diffuse in all directions. The control of the motion of Al is further demonstrated by achieving a 90° turn, using a graphene device patterned in a crossroads configuration. The controlled motion of Al is attributed to the charge transfer from Al onto the graphene so that the Al is effectively charged and can be accelerated by the applied electric field. To get further insight into the actuation mechanism, theoretical simulations of individual Al and Au impurities on a perfect graphene sheet were performed. The direct (electrostatic) force was found to be ～1 pN and dominant over the wind force. These findings hold promise for practical use in future mass transport in complex circuits.     

Analysis of the necessary radioprotection procedures in manufacture of iodine-125 sources used in brachytherapy: A preliminary study

The estimates for the year 2009 predict that 466,730 new cancer cases would occur in Brazil. Prostate cancer is the second most incident in our country, with almost 50,000 new cases in 2009. Brachytherapy, a type of radiotherapy, with iodine-125 sources is an important form of treatment for this kind of cancer. The “Instituto de Pesquisas Energéticas e Nucleares” (Institute for Nuclear and Energy Research - IPEN) created a project to produce a national prototype of these sources and develop a facility for local production. Manufacturing seeds locally will diminish the overall treatment cost making such treatment available to a larger number of patients. While the laboratory is under development, the IPEN imports and distributes seeds. This work aims to present and evaluate the radiological protection procedures applied to imported sources in order to assist in the setup of the new laboratory. Although iodine-125 presents low energy photons, around 29 keV, local and personal dosimeters are used during the separation and distribution process of seeds as described in CNEN NN 3.01 standard “Diretrizes Básicas de Proteção Radiológica” (Radiological Protection Basic Guidelines). All testing has demonstrated that there is no area contamination and very low exposure, suggesting that the application of the standards outlined in CNEN NN 3.01 has been effective. As a result of this work, a new dosimeter should be installed and evaluated in a future study.     

Solar irradiation and PV module temperature dispersion at a large‐scale PV plant

When evaluating the performance of a photovoltaic (PV) system, it is extremely important to correctly measure the plant operating conditions: incident irradiation and cell temperature. At large‐size PV plants, the possible dispersion of the plant operating conditions may affect the representativeness of the values measured at one single point. The available literature contains many observations on irradiance dispersion (typically associated to high temporal resolution experiments) and its effects on the PV power output (unexpected power transients, power fluctuations, etc.). However no studies have been made on the long‐term energy‐related effects of geographic dispersion of solar irradiation, which could affect, for example, to the uncertainty in determining energy performance indexes like PR. This paper analyses the geographical dispersion in the PV operating conditions observed at low temporal resolutions (day, month and year) at two PV plants located, respectively, in the south of Portugal and the north of Spain. It shows that daily irradiation deviations are significantly higher than is commonly supposed. Furthermore, once the measurement points are a certain distance apart (a few hundred metres), the deviations in irradiation appear to be independent of distance. This could help to determine how many irradiance sensors to install in order to reduce uncertainty. Daily mean temperature differences between different points at a large‐scale PV plant range from 1 to 7 K and are not related to the distance between measurement points. Copyright © 2014 John Wiley & Sons, Ltd.     

Can multiscale traffic analysis be used to differentiate Internet applications?

An accurate mapping of Internet traffic to applications can be important for a broad range of network management and measurement tasks, including traffic engineering, service differentiation, performance/failure monitoring and security. Traditional mapping approaches have become increasingly inaccurate because many applications use non-default or ephemeral port numbers, use well-known port numbers associated with other applications, change application signatures or use traffic encryption. In this paper we will demonstrate that multiscale traffic analysis based on multi-order wavelet spectrum can be used as a discriminator of Internet applications traffic profiles. By performing clustering analysis over the multiscale wavelet spectrum coefficients that are inferred from the measured traffic, the proposed methodology is able to efficiently differentiate different IP applications without using any payload information. This characteristic will allow the differentiation of traffic flows in unencrypted and encrypted scenarios. In order to compare the differentiating potential of different traffic application data, upload, download and joint upload and download flow statistics are considered to evaluate the identification approach for each selected protocol. Moreover, we also evaluate which timescales and spectrum orders are more relevant for the traffic differentiation. From the analysis of the obtained results we can conclude that the proposed methodology is able to achieve good identification results using a small set of timescales of a single order wavelet spectrum of a general raw traffic statistic.     

Description of the immatures of workers of the ant Linepithema micans forel (Hymenoptera: Formicidae)

Linepithema micans Forel is a poorly studied species that is now considered a pest in vineyards in South Brazil. Larval characters have been used in a few phylogenetic studies, and their importance greatly depends in the amount of available information on different species. This study presents a complete panorama on the external morphology of the immatures of L. micans based on observations by light and scanning electron microscopy. The number of larval instars was estimated as three based on the frequency distribution of head widths of 965 larvae. Larvae of L. micans were similar to other Linepithema Mayr in the general format of body and mandibles, presenting a dorsal abdominal protuberance, nine pairs of spiracle, and unbranched hairs. On the other hand, L. micans was unique for having shorter hairs, predominantly denticulate, intraspecific variation in the number of antennal sensilla and in the types of sensilla on the labial palps were reported. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.     

Nano and submicrometric fibers of poly(D,L‐lactide) obtained by solution blow spinning: Process and solution variables

Nano and submicrometric fibers of poly(D ,L ‐lactide) (PDLLA or PLA) were spun from solutions using a solution blow spinning (SBS) apparatus. Fiber morphology and diameter were investigated by scanning electron microscopy as a function of polymer concentration, feed rate, and air pressure. A more systematic understanding of the SBS process parameters was obtained, and a quantitative relationship between these parameters and average fiber diameter was established by design of experiments and response surface methodology. It was observed that polymer concentration played an important role in fiber diameter, which ranges from 70 to 2000 nm, and its distribution. Lower polymer concentration tended to increase the formation of bead‐on‐string structures, whereas smooth fibers were formed at higher concentrations. Fiber diameter tended to increase with polymer concentration and decrease with feed rate. Based on these results, optimal conditions could be obtained for solution‐blow spun fibers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Review of kinetic models for supercritical fluid extraction

The supercritical fluid extraction (SFE) of liquids and solid materials is gaining increasing interest and commercial application in last decades, most particularly under the recent concept of green chemistry and biorefinery. Hence, it is fundamental to provide adequate modeling of the SFE, in order to optimize operating conditions and simulate the global process. This work intends to review the most significant and physically sound models published in the literature for countercurrent liquid-supercritical fluid extraction and SFE of solid matrices, such as the linear driving force, shrinking core, broken and intact cells, and the combination of BIC and shrinking core models. The main assumptions and mass transfer expressions are presented and discussed.     

Critical investigation of preconditioned GMRES via incomplete LU factorization applied to power flow simulation

For solving the power flow sublinear problem efficiently by the GMRES preconditioned via incomplete LU factorization (ILU), this paper investigates causes associated to the preconditioner low quality and proposes a method to improve it and the GMRES convergence rate as well. The goal is provide a well-organized ILU-GMRES for solving linear systems of difficult solution comprising ill-conditioned coefficient matrices, normally associated to heavy load power systems. The investigations reveal that a dropping rule for nonzero elements (fill-ins) based on a relative tolerance may introduce large errors during the preconditioner construction, lowering its quality and the GMRES performance. Based on that, it is proposed a fill-in dropping rule making use of two criteria; one based on the resulting error and the other based on a relative tolerance, applied to the preconditioner lower (L) and upper (U) triangular matrices, respectively. Ordering schemes are also considered. Numerical experiments taking into account different power system configurations operating under heavy load conditions corroborate the efficiency of such strategies.