Droplet mixer based on siphon-induced flow discretization and phase shifting

We present a novel mixing principle for centrifugal microfluidic platforms. Siphon structures are designed to disrupt continuous flows in a controlled manner into a sequence of discrete droplets, displaying individual volumes as low as 60 nL. When discrete volumes of different liquids are alternately issued into a common reservoir, a striation pattern of alternating liquid layers is obtained. In this manner diffusion distances are drastically decreased and a fast and homogeneous mixing is achieved. Efficient mixing is demonstrated for a range of liquid combinations of varying fluid properties such as aqueous inks or saline solutions and human plasma. Volumes of 5 muL have been mixed in less than 20 s to a high mixing quality. One-step dilutions of plasma in a standard phosphate buffer solution up to 1:5 are also demonstrated

Umbuzeiro (Spondia tuberosa, Arr. Câm) de frutos gigantes.

O umbuzeiro é originado dos chapadões semi-áridos do Nordeste brasileiro (Piauí, Paraíba, Pernambuco e Bahia) e do Norte de Minas Gerais. Até o momento, essa planta não foi difundida para nenhum outro país, sendo possível sua adaptação para outras regiões secas fora do país de origem. Árvore de pequeno porte (6 m de altura), de tronco curto, copa em forma de guarda-chuva (10 a 15 m de diâmetro), xerófita e de vida longa (mais de 100 anos), possui raiz túbera ou batata (xilopódio), onde armazena água, mucilagem, glicose, taninos, entre outras).bitstream/item/25866/1/http-agrosoft.com-pdfID27248Fonseca.pdfDisponível em: Acesso em: 21 jan. 2011

Dynamical star-disk interaction in the young stellar system V354 Mon

The main goal of this work is to characterize the mass accretion and ejection processes of the classical T Tauri star V354 Mon, a member of the young stellar cluster NGC 2264. In March 2008, photometric and spectroscopic observations of V354 Mon were obtained simultaneously with the CoRoT satellite, the 60 cm telescope at the Observat\'orio Pico dos Dias (LNA - Brazil) equipped with a CCD camera and Johnson/Cousins BVRI filters, and the SOPHIE \'echelle spectrograph at the Observatoire de Haute-Provence (CNRS - France). The light curve of V354 Mon shows periodical minima (P = 5.26 +/- 0.50 days) that vary in depth and width at each rotational cycle. From the analysis of the photometric and spectroscopic data, it is possible to identify correlations between the emission line variability and the light-curve modulation of the young system, such as the occurrence of pronounced redshifted absorption in the H_alpha line at the epoch of minimum flux. This is evidence that during photometric minima we see the accretion funnel projected onto the stellar photosphere in our line of sight, implying that the hot spot coincides with the light-curve minima. We applied models of cold and hot spots and a model of occultation by circumstellar material to investigate the source of the observed photometric variations. We conclude that nonuniformly distributed material in the inner part of the circumstellar disk is the main cause of the photometric modulation, which does not exclude the presence of hot and cold spots at the stellar surface. It is believed that the distortion in the inner part of the disk is created by the dynamical interaction between the stellar magnetosphere, inclined with respect to the rotation axis, and the circumstellar disk, as also observed in the classical T Tauri star AA Tau and predicted by magnetohydrodynamical numerical simulations.Comment: Accepted by Astronomy and Astrophysic

Conditions for the onset of the current filamentation instability in the laboratory

Current Filamentation Instability (CFI) is capable of generating strong magnetic fields relevant to explain radiation processes in astrophysical objects and lead to the onset of particle acceleration in collisionless shocks. Probing such extreme scenarios in the laboratory is still an open challenge. In this work, we investigate the possibility of using neutral $e^{-}$ $e^{+}$ beams to explore the CFI with realistic parameters, by performing 2D particle-in-cell simulations. We show that CFI can occur unless the rate at which the beam expands due to finite beam emittance is larger than the CFI growth rate and as long as the role of competing electrostatic two-stream instability (TSI) is negligible. We also show that the longitudinal energy spread, typical of plasma based accelerated electron-positron fireball beams, plays a minor role in the growth of CFI in these scenarios

On the end-to-end delay analysis for an IEEE 802.11P/WAVE protocol

The use of IEEE 802.11p for supporting intelligent transportation systems (ITS) allows a wide spectrum of applications providing vehicle occupants useful information related to public safety and road efficiency. The Wireless Access for Vehicular Environment (WAVE) standard is specifically tailored for delivering safety and multimedia messages in a highly dynamic vehicular communication environment. Such dynamic characteristics along with the delay critical nature of safety services turn the medium access control protocol (MAC) timings very important. Therefore, it becomes of great interest to analyze a major performance metric, the end-to-end delay.info:eu-repo/semantics/publishedVersio

The pinewood nematode, Bursaphelenchus xylophilus, in Madeira Island

The environmental conditions in Madeira Island are favorable for the presence and dissemination of the pinewood nematode (PWN), Bursaphelenchus xylophilus. Five hundred Pinus pinaster wood samples were collected in several forest areas and PWN was detected in 22.8 % of the samples. Bursaphelenchus xylophilus isolates from Madeira Island displayed the species-specific diagnostic characters. A morphological variation in the female tail terminus was detected. In most females, the tail presented a broadly rounded terminus and, occasionally, a digitate terminus with a terminal nipple-like extension resembling a mucro. PCR ITS-RFLP analysis revealed that Madeira Island isolates exhibited patterns specific to the species B. xylophilus and similar to virulent isolates. Amplified ITS regions were further sequenced and no genetic diversity was found for this genomic region among 17 Portuguese isolates (Madeira Island and Continental Portugal). Phylogenetic analysis revealed that Portuguese isolates grouped with isolates from China, Korea and one isolate from Japa

On Dirac-like Monopoles in a Lorentz- and CPT-violating Electrodynamics

We study magnetic monopoles in a Lorentz- and CPT-odd electrodynamical framework in (3+1) dimensions. This is the standard Maxwell model extended by means of a Chern-Simons-like term, $b_\mu\tilde{F}^{\mu\nu}A_\nu$ ($b_\mu$ constant), which respects gauge invariance but violates both Lorentz and CPT symmetries (as a consequence, duality is also lost). Our main interest concerns the analysis of the model in the presence of Dirac monopoles, so that the Bianchi identity no longer holds, which naively yields the non-conservation of electric charge. Since gauge symmetry is respected, the issue of charge conservation is more involved. Actually, the inconsistency may be circumvented, if we assume that the appearance of a monopole induces an extra electric current. The reduction of the model to (2+1) dimensions in the presence of both the magnetic sources and Lorentz-violating terms is presented. There, a quantization condition involving the scalar remnant of $b_\mu$, say, the mass parameter, is obtained. We also point out that the breaking of duality may be associated with an asymmetry between electric and magnetic sources in this background, so that the electromagnetic force experienced by a magnetic pole is supplemented by an extra term proportional to $b_\mu$, whenever compared to the one acting on an electric charge.Comment: 10 pages, no figures, typed in te

Alocação Renal: Novas Contribuições para um Desafio Permanente

info:eu-repo/semantics/publishedVersio

Comparative study between sequential use of Foley catheter with vaginal misoprostol versus sequential use of oral mifepristone with vaginal misoprostol for second trimester medical abortion

Background: Abortions are one of the most commonly performed procedures in gynaecological departments worldwide. They are still a major problem in developing countries contributing to a significant percentage of maternal morbidity and mortality. The main objective of this study is to compare the efficacy, side effects and acceptability of intracervical Foley and oral Mifepristone both followed with sequential administration of vaginal misoprostol for second trimester medical abortion.Methods: This was a prospective randomized trial of 36 healthy women opting for termination of pregnancy with ultrasound confirmed intrauterine gestation between 12 to 20 completed weeks. Intracervical Foley catheter with administration of misoprostol (200µg) vaginally was done for Group A. Mifepristone 200mg was administered on day one followed by misoprostol (200µg) vaginally, 48 hours later, to Group B. Both groups received misoprostol (200µg) vaginally at 4 hourly intervals. Completeness of abortion was assessed, and surgical evacuation was performed, if abortion was found to be incomplete.Results: The two groups were comparable with respect to age, parity and gestational age. 83-89% of the women in both the groups had complete abortion. The mean induction abortion interval was 20.11 hours in Group A and 54.77 hours in Group B, which was statistically significant. Side effect profile was comparable in both groups however the intensity and the duration of persistence of pain was greater among patients from Group A.Conclusions: Authors conclude that medical abortions with both methods were found to be safe, effective, inexpensive and acceptable methods. Whereas a shorter induction abortion interval was observed in the Foley induction group, induction with mifepristone was the preferred regimen in second trimester abortion because of its high efficacy, low incidence of side effects, better tolerance by the patients and due to lower dose of misoprostol required following mifepristone administration