274 research outputs found
Cortical Stimulation and Language Outcomes in Aphasia
With the increased focus on evidenced-based outcomes in Speech-Language Pathology, a trend towards inclusion of instrumentation and technology in the treatment of aphasia has emerged. One technique at the forefront of this movement is the use of cortical stimulation as an adjunct to behavioral interventions. The purposes of this brief analysis are to review articles published over the course of six years (2006-2011) that combine stimulation with language treatment and to report trends that emerge
Bose-Einstein Condensate in Weak 3d Isotropic Speckle Disorder
The effect of a weak three-dimensional (3d) isotropic laser speckle disorder
on various thermodynamic properties of a dilute Bose gas is considered at zero
temperature. First, we summarize the derivation of the autocorrelation function
of laser speckles in 1d and 2d following the seminal work of Goodman. The goal
of this discussion is to show that a Gaussian approximation of this function,
proposed in some recent papers, is inconsistent with the general background of
laser speckle theory. Then we propose a possible experimental realization for
an isotropic 3d laser speckle potential and derive its corresponding
autocorrelation function. Using a Fourier transform of that function, we
calculate both condensate depletion and sound velocity of a Bose-Einstein
condensate as disorder ensemble averages of such a weak laser speckle potential
within a perturbative solution of the Gross-Pitaevskii equation. By doing so,
we reproduce the expression of the normalfluid density obtained earlier within
the treatment of Landau. This physically transparent derivation shows that
condensate particles, which are scattered by disorder, form a gas of
quasiparticles which is responsible for the normalfluid component
Three-dimensional localization of ultracold atoms in an optical disordered potential
We report a study of three-dimensional (3D) localization of ultracold atoms
suspended against gravity, and released in a 3D optical disordered potential
with short correlation lengths in all directions. We observe density profiles
composed of a steady localized part and a diffusive part. Our observations are
compatible with the self-consistent theory of Anderson localization, taking
into account the specific features of the experiment, and in particular the
broad energy distribution of the atoms placed in the disordered potential. The
localization we observe cannot be interpreted as trapping of particles with
energy below the classical percolation threshold.Comment: published in Nature Physics; The present version is the initial
manuscript (unchanged compared to version 1); The published version is
available online at
http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys2256.htm
A Green's function approach to transmission of massless Dirac fermions in graphene through an array of random scatterers
We consider the transmission of massless Dirac fermions through an array of
short range scatterers which are modeled as randomly positioned -
function like potentials along the x-axis. We particularly discuss the
interplay between disorder-induced localization that is the hallmark of a
non-relativistic system and two important properties of such massless Dirac
fermions, namely, complete transmission at normal incidence and periodic
dependence of transmission coefficient on the strength of the barrier that
leads to a periodic resonant transmission. This leads to two different types of
conductance behavior as a function of the system size at the resonant and the
off-resonance strengths of the delta function potential. We explain this
behavior of the conductance in terms of the transmission through a pair of such
barriers using a Green's function based approach. The method helps to
understand such disordered transport in terms of well known optical phenomena
such as Fabry Perot resonances.Comment: 22 double spaced single column pages. 15 .eps figure
Integration of multiple platforms for the analysis of multifluorescent marking technology applied to pediatric GBM and dipg
The intratumor heterogeneity represents one of the most difficult challenges for the development of effective therapies to treat pediatric glioblastoma (pGBM) and diffuse intrinsic pontine glioma (DIPG). These brain tumors are composed of heterogeneous cell subpopulations that coexist and cooperate to build a functional network responsible for their aggressive phenotype. Understanding the cellular and molecular mechanisms sustaining such network will be crucial for the identification of new therapeutic strategies. To study more in-depth these mechanisms, we sought to apply the Multifluorescent Marking Technology. We generated multifluorescent pGBM and DIPG bulk cell lines randomly expressing six different fluorescent proteins and from which we derived stable optical barcoded single cell-derived clones. In this study, we focused on the application of the Multifluorescent Marking Technology in 2D and 3D in vitro/ex vivo culture systems. We discuss how we integrated different multimodal fluorescence analysis platforms, identifying their strengths and limitations, to establish the tools that will enable further studies on the intratumor heterogeneity and interclonal interactions in pGBM and DIPG
A method for visualising fluorescence of flavonoid therapeutics in vivo in the model eukaryote Dictyostelium discoideum
Naturstoff reagent A (diphenylboric acid 2-aminoethyl ester, DPBA) has been used historically in plant science to observe polyphenolic pigments, such as flavonoids, whose fluorescence requires enhancement to be visible by microscopy. Flavonoids are common dietary constituents and are the focus of considerable attention because of their potential as novel therapies for numerous diseases. The molecular basis of therapeutic activity is only gradually being established, and one strand of such research is making use of the social amoeba Dictyostelium discoideum. We extended the application of DPBA to flavonoid imaging in these preclinical studies and report the first method for use of DPBA in this eukaryotic model microbe, and its applicability alongside subcellular markers. This in vivo fluorescence imaging provided a useful adjunct to parallel chemical and genetic studies
Effect of random on-site energies on the critical temperature of a lattice Bose gas
We study the effect of random on-site energies on the critical temperature of
a non-interacting Bose gas on a lattice. In our derivation the on-site energies
are distributed according a Gaussian probability distribution function having
vanishing average and variance . By using the replicated action obtained
by averaging on the disorder, we perform a perturbative expansion for the Green
functions of the disordered system. We evaluate the shift of the chemical
potential induced by the disorder and we compute, for , the
critical temperature for condensation. We find that, for large filling,
disorder slightly enhances the critical temperature for condensation.Comment: To appear in Laser Physics, issue on the LPHYS'08 conference
(Trondheim, 2008
Caribbean Corals in Crisis: Record Thermal Stress, Bleaching, and Mortality in 2005
BACKGROUND The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. METHODOLOGY/PRINCIPAL FINDINGS Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. CONCLUSIONS/SIGNIFICANCE Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.This work was partially supported by salaries from the NOAA Coral Reef Conservation Program to the NOAA Coral Reef Conservation Program authors. NOAA provided funding to Caribbean ReefCheck investigators to undertake surveys of bleaching and mortality. Otherwise, no funding from outside authors' institutions was necessary for the undertaking of this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Parent-child interaction during adolescence, and the adolescent's sexual experience: Control, closeness, and conflict.
Diversity of lactic acid bacteria of the bioethanol process
<p>Abstract</p> <p>Background</p> <p>Bacteria may compete with yeast for nutrients during bioethanol production process, potentially causing economic losses. This is the first study aiming at the quantification and identification of Lactic Acid Bacteria (LAB) present in the bioethanol industrial processes in different distilleries of Brazil.</p> <p>Results</p> <p>A total of 489 LAB isolates were obtained from four distilleries in 2007 and 2008. The abundance of LAB in the fermentation tanks varied between 6.0 × 10<sup>5 </sup>and 8.9 × 10<sup>8 </sup>CFUs/mL. Crude sugar cane juice contained 7.4 × 10<sup>7 </sup>to 6.0 × 10<sup>8 </sup>LAB CFUs. Most of the LAB isolates belonged to the genus <it>Lactobacillus </it>according to rRNA operon enzyme restriction profiles. A variety of <it>Lactobacillus </it>species occurred throughout the bioethanol process, but the most frequently found species towards the end of the harvest season were <it>L. fermentum </it>and <it>L. vini</it>. The different rep-PCR patterns indicate the co-occurrence of distinct populations of the species <it>L. fermentum </it>and <it>L. vini</it>, suggesting a great intraspecific diversity. Representative isolates of both species had the ability to grow in medium containing up to 10% ethanol, suggesting selection of ethanol tolerant bacteria throughout the process.</p> <p>Conclusions</p> <p>This study served as a first survey of the LAB diversity in the bioethanol process in Brazil. The abundance and diversity of LAB suggest that they have a significant impact in the bioethanol process.</p
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