Kinetics of phase transformation in depletion driven colloids

PACS number(s): 82.70.Gg, 82.70.RrWe present results from a detailed numerical study of the kinetics of phase transformations in a model two-dimensional depletion-driven colloidal system. Transition from a single, dispersed phase to a two-phase coexistence of monomers and clusters is obtained as the depth of the interaction potential among the colloidal particles is changed. Increasing the well depth further, fractal clusters are observed in the simulation. These fractal clusters have a hybrid structure in the sense that they show hexagonal closed-packed crystalline ordering at short length scales and a ramified fractal nature at larger length scales. For sufficiently deep potential wells, the diffusion-limited cluster-cluster aggregation model is recovered in terms of the large-scale fractal dimension Df of the clusters, the kinetic exponent z, and the scaling form of the cluster size distribution. For shallower well depths inside the two-phase coexistence region, simulation results for the kinetics of cluster growth are compared with intermediate-stage phase separation in binary mixtures. In the single-phase region, growth kinetics agree well with a mean-field aggregation-fragmentation model of Sorensen, Zhang, and Taylor.J.J.C. and T.S. acknowledge financial support from the Spanish MCyT through Grant No. BMF2001-0341-C02-01. A.C. and C.S.were supported by NASA through Grant No. NAG 3-2360Peer reviewe

On the effect of measurementmodel misspecification in PLS Path Modeling: the reflective case

The specification of a measurement model as reflective or formative is the object of a lively debate. Part of the existing literature focuses on measurement model misspecification. This means that a true model is assumed and the impact on the path coefficients of using a wrong model is investigated. The majority of these studies is restricted to Structural Equation Modeling (SEM). Regarding PLS-Path Modeling (PLS-PM), a few authors have carried out simulation studies to investigate the robustness of the estimates, but their focus is the comparison with SEM. The present paper discusses the misspecification problem in the PLSPM context from a novel perspective. First, a real application on Alumni Satisfaction will be used to verify whether different assumptions for the measurements models influence the results. Second, the results of a Monte-Carlo simulation study, in the reflective case, will help to bring some clarity on a complex problem that has not been sufficiently studied yet

SiRCub - Brazilian Agricultural Crop Recognition System.

This paper presents a novel approach to classify agricultural crops using NDVI time series. The novelty lies in i) extracting a set of features from the each and every NDVI curve, and ii) using them to train a crop classification model using a Support Vector Machine (SVM). Specifically, we use the TIMESAT program package to: 1) smooth the time series, 2) decompose them into agricultural seasons?a season is the period between sowing and harvesting?, and 3) extract the features for each season.SBSR 2015

The genome of the vervet (Chlorocebus aethiops sabaeus)

Warren, Wesley C. et al.We describe a genome reference of the African green monkey or vervet (Chlorocebus aethiops). This member of the Old World monkey (OWM) superfamily is uniquely valuable for genetic investigations of simian immunodeficiency virus (SIV), for which it is the most abundant natural host species, and of a wide range of health-related phenotypes assessed in Caribbean vervets (C. a. sabaeus), whose numbers have expanded dramatically since Europeans introduced small numbers of their ancestors from West Africa during the colonial era. We use the reference to characterize the genomic relationship between vervets and other primates, the intra-generic phylogeny of vervet subspecies, and genome-wide structural variations of a pedigreed C. a. sabaeus population. Through comparative analyses with human and rhesus macaque, we characterize at high resolution the unique chromosomal fission events that differentiate the vervets and their close relatives from most other catarrhine primates, in whom karyotype is highly conserved. We also provide a summary of transposable elements and contrast these with the rhesus macaque and human. Analysis of sequenced genomes representing each of the main vervet subspecies supports previously hypothesized relationships between these populations, which range across most of sub-Saharan Africa, while uncovering high levels of genetic diversity within each. Sequence-based analyses of major histocompatibility complex (MHC) polymorphisms reveal extremely low diversity in Caribbean C. a. sabaeus vervets, compared to vervets from putatively ancestral West African regions. In the C. a. sabaeus research population, we discover the first structural variations that are, in some cases, predicted to have a deleterious effect; future studies will determine the phenotypic impact of these variations.Funding to R.K.W. was provided by NIH-NHGRI grant 5U54HG00307907. Support for the Vervet Research Colony was provided by NIH grant RR019963/OD010965 to J.R.K. Funding to N.B.F. was provided by NIH grants R01RR016300 and R01OD010980. The French National Agency for Research on AIDS and Viral Hepatitis (ANRS) provided funding to M.C.M.-T. Funding to M.R. and R.S. was provided by the Ministero della Universita’ e della Ricerca. Funding to K.D. was provided by Genome Canada and Genome Quebec. B.A. and R.N. acknowledge support from the Wellcome Trust (grant number WT095908) and the European Molecular Biology Laboratory.Peer reviewe

Exploiting the neutronization burst of a galactic supernova

One of the robust features found in simulations of core-collapse supernovae (SNe) is the prompt neutronization burst, i.e. the first $\sim 25$ milliseconds after bounce when the SN emits with very high luminosity mainly $\nu_e$ neutrinos. We examine the dependence of this burst on variations in the input of current SN models and find that recent improvements of the electron capture rates as well as uncertainties in the nuclear equation of state or a variation of the progenitor mass have only little effect on the signature of the neutronization peak in a megaton water Cherenkov detector for different neutrino mixing schemes. We show that exploiting the time-structure of the neutronization peak allows one to identify the case of a normal mass hierarchy and large 13-mixing angle $\theta_{13}$, where the peak is absent. The robustness of the predicted total event number in the neutronization burst makes a measurement of the distance to the SN feasible with a precision of about 5%, even in the likely case that the SN is optically obscured.Comment: 14 pages, 17 eps figures, revtex4 style, minor comments adde

Signatures of supernova neutrino oscillations in the Earth mantle and core

The Earth matter effects on supernova (SN) neutrinos can be identified at a single detector through peaks in the Fourier transform of their ``inverse energy'' spectrum. The positions of these peaks are independent of the SN models and therefore the peaks can be used as a robust signature of the Earth matter effects, which in turn can distinguish between different neutrino mixing scenarios. Whereas only one genuine peak is observable when the neutrinos traverse only the Earth mantle, traversing also the core gives rise to multiple peaks. We calculate the strengths and positions of these peaks analytically and explore their features at a large scintillation detector as well as at a megaton water Cherenkov detector through Monte Carlo simulations. We propose a simple algorithm to identify the peaks in the actual data and quantify the chances of a peak identification as a function of the location of the SN in the sky.Comment: 17 pages, 9 figure

The Complete Structure of the Core Oligosaccharide from Edwardsiella tarda EIB 202 Lipopolysaccharide

The chemical structure and genomics of the lipopolysaccharide (LPS) core oligosaccharide of pathogenic Edwardsiella tarda strain EIB 202 were studied for the first time. The complete gene assignment for all LPS core biosynthesis gene functions was acquired. The complete structure of core oligosaccharide was investigated by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry MSn, and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry. The following structure of the undecasaccharide was established: The heterogeneous appearance of the core oligosaccharide structure was due to the partial lack of β-d-Galp and the replacement of α-d-GlcpNAcGly by α-d-GlcpNGly. The glycine location was identified by mass spectrometry

Effects on nasal nitric oxide production of 2 mechanisms of vasoconstriction

Background: Vasoconstrictor drugs reduce nitric oxide (NO) production in vitro by inhibiting the enzyme involved in the regulation of inducible and constitutive NO synthases (iNOS and cNOS). Intranasal vasoconstrictors also decrease nasal NO concentration in vivo. It is as yet unclear if this last finding is due to the effects of the drug on the enzyme or on the vessels. Physical exercise also induces nasal vasoconstriction and reduces nasal resistance. Objectives: The aim of this study was to clarify the mechanisms involved in xylometazoline-induced reduction of nasal NO concentration. Methods: We compared 2 randomized groups of patients with moderate-severe persistent allergic rhinitis. The fi rst group (n=24) underwent a physiological nasal vasoconstrictor stimulus (exercise) whereas the second group (n=29) was treated with a nasal vasoconstrictor drug (topical xylometazoline). Nasal volume and NO were determined at baseline and 15 to 20 minutes after the end of each stimulus using acoustic rhinometry and chemiluminescence, respectively. Results: Baseline values of nasal volume and NO did not differ between the 2 groups. Nasal volume increased by 57% (P = .0001) after exercise and 71% (P = .0001) after xylometazoline. Nasal NO decreased (25%, P = .001) after xylometazoline, but not after exercise. Conclusion: Physical exercise and topical xylometazoline cause vasoconstriction and similar effects on nasal volume. In contrast nasal NO decreased with xylometazoline but not after exercise. These fi ndings suggest that vasoconstrictor drugs reduce nasal NO by mechanisms other than vasoconstriction

Non-adiabatic level crossing in (non-) resonant neutrino oscillations

We study neutrino oscillations and the level-crossing probability P_{LZ}=\exp(-\gamma_n\F_n\pi/2) in power-law like potential profiles $A(r)\propto r^n$. After showing that the resonance point coincides only for a linear profile with the point of maximal violation of adiabaticity, we point out that the ``adiabaticity'' parameter $\gamma_n$ can be calculated at an arbitrary point if the correction function \F_n is rescaled appropriately. We present a new representation for the level-crossing probability, P_{LZ}=\exp(-\kappa_n\G_n), which allows a simple numerical evaluation of $P_{LZ}$ in both the resonant and non-resonant cases and where \G_n contains the full dependence of $P_{LZ}$ on the mixing angle $\theta$. As an application we consider the case $n=-3$ important for oscillations of supernova neutrinos.Comment: 4 pages, revtex, 3 eps figure