Disentangling protostellar evolutionary stages in clustered environments using Spitzer-IRS spectra and comprehensive SED modeling

When studying the evolutionary stages of protostars that form in clusters, the role of any intracluster medium cannot be neglected. High foreground extinction can lead to situations where young stellar objects (YSOs) appear to be in earlier evolutionary stages than they actually are, particularly when using simple criteria like spectral indices. To address this issue, we have assembled detailed SED characterizations of a sample of 56 Spitzer-identified candidate YSOs in the clusters NGC 2264 and IC 348. For these, we use spectra obtained with the Infrared Spectrograph onboard the Spitzer Space Telescope and ancillary multi-wavelength photometry. The primary aim is twofold: 1) to discuss the role of spectral features, particularly those due to ices and silicates, in determining a YSO's evolutionary stage, and 2) to perform comprehensive modeling of spectral energy distributions (SEDs) enhanced by the IRS data. The SEDs consist of ancillary optical-to-submillimeter multi-wavelength data as well as an accurate description of the 9.7 micron silicate feature and of the mid-infrared continuum derived from line-free parts of the IRS spectra. We find that using this approach, we can distinguish genuine protostars in the cluster from T Tauri stars masquerading as protostars due to external foreground extinction. Our results underline the importance of photometric data in the far-infrared/submillimeter wavelength range, at sufficiently high angular resolution to more accurately classify cluster members. Such observations are becoming possible now with the advent of the Herschel Space Observatory.Comment: Accepted for publication in Ap

mRNA transcription profile of potato (Solanum tuberosum L.) exposed to ultrasound during different stages of in vitro plantlet development

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Experimental Demonstration of a Frequency-Domain Volterra Series Nonlinear Equalizer in Polarization-Multiplexed Transmission

Experimental demonstration of a dual-polarization Volterra series nonlinear equalizer applied in frequency-domain is carried out for 100G polarization-multiplexed QPSK test signals. We were able to reduce the BER by a factor of ~2.5x relatively to the single-polarization approach, with a 1 dB increase in the optimum power

Transcriptomic Response of In Vitro Potato (Solanum tuberosum L.) to Piezoelectric Ultrasound

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Complementation of wild strawberry (Fragaria vesca L.) SPATULA (FvSPT) and SPIRAL (FvSPR) genes in Arabidopsis thaliana

This study assessed the function of genes involved in wild strawberry (Fragaria vesca L.) fruit development and maturation to better understand the mechanism of non-climacteric fruit ripening. SPATULA (FvSPT) and SPIRAL (FvSPR) genes of Fragaria vesca displayed differential expression between the green and red ripening stages. SPT, which encodes a bHLH transcription factor, was characterized in Arabidopsis thaliana L. where its recessive mutation caused degenerative carpel and fruit development. The spt mutant of A. thaliana had shorter, smaller, and wider spatula-shaped siliques than the wild type. SPT was expressed throughout the development of marginal and transmission tract tissues, confirming its role in regulating the growth of these tissues. Two A. thaliana SPIRAL genes, SPR1 and SPR2, are required for directional control of cell elongation. Recessive mutations in either of these genes decreased anisotropic growth of endodermal and cortical root cells and etiolated hypocotyls and caused right-handed helical growth in epidermal cells. The strawberry SPATULA (FvSPT) and SPIRAL (FvSPR) genes were amplified and spt and spr mutant A. thaliana plants were transformed with FvSPT::pGWB401, FvSPR1-1::pGWB401 and FvSPR1-2::pGWB401 vector constructs. Silique length and seed number/silique in the A. thaliana spt mutant were effectively complemented by FvSPT whereas spr was almost fully complemented by FvSPR1-2, but not by FvSPR1-1

In vitro tissue culture of apple and other Malus species: recent advances and applications

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mRNA transcription profile of potato (Solanum tuberosum L.) in response to explant cutting

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Assessing Noncoding Sequence Variants of GJB2 for Hearing Loss Association.

Involvement of GJB2 noncoding regions in hearing loss (HL) has not been extensively investigated. However, three noncoding mutations, c.-259C>T, c.-23G>T, and c.-23+1G>A, were reported. Also, c.-684 -675del, of uncertain pathogenicity, was found upstream of the basal promoter. We performed a detailed analysis of GJB2 noncoding regions in Portuguese HL patients (previously screened for GJB2 coding mutations and the common GJB6 deletions) and in control subjects, by sequencing the basal promoter and flanking upstream region, exon 1, and 3’UTR. All individuals were genotyped for c.-684 -675del and 14 SNPs. Novel variants (c.-731C>T, c.-26G>T, c.∗45G>A, and c.∗985A>T) were found in controls. A hearing individual homozygous for c.-684 - 675del was for the first time identified, supporting the nonpathogenicity of this deletion. Our data indicate linkage disequilibrium (LD) between SNPs rs55704559 (c.∗168A>G) and rs5030700 (c.∗931C>T) and suggest the association of c.[∗168G;∗931T] allele with HL. The c.∗168A>G change, predicted to alter mRNA folding, might be involved in HL.info:eu-repo/semantics/publishedVersio

Spectrum and Frequency of GJB2 Mutations in a Cohort of 264 Portuguese Nonsyndromic Sensorineural Hearing Loss Patients

OBJECTIVE: To assess the spectrum and prevalence of mutations in the GJB2 gene in Portuguese nonsyndromic sensorineural hearing loss (NSSHL) patients. DESIGN: Sequencing of the coding region, basal promoter, exon 1, and donor splice site of the GJB2 gene; screening for the presence of the two common GJB6 deletions. STUDY SAMPLE: A cohort of 264 Portuguese NSSHL patients. RESULTS: At least one out of 21 different GJB2 variants was identified in 80 (30.2%) of the 264 patients analysed. Two mutant alleles were found in 53 (20%) of these probands, of which 83% (44/53) harboured at least one c.35delG allele. Twenty-seven (10.2%) of the probands harboured only one mutant allele. Subsequent analysis revealed that the GJB6 deletion del(GJB6-D13S1854) was present in at least 7.4% (2/27) of the patients carrying only one mutant GJB2 allele. Overall, one in five (55/264) of the patients were diagnosed as having DFNB1-related NSSHL, of which the vast majority (53/55) harboured only GJB2 mutations. CONCLUSIONS: This study provides clear demonstration that mutations in the GJB2 gene are an important cause of NSSHL in Portugal, thus representing a valuable indicator as regards therapeutical and rehabilitation options, as well as genetic counseling of these patients and their families

Promoter analysis of the SPATULA (FvSPT) and SPIRAL (FvSPR) genes in the woodland diploid strawberry (Fragaria vesca L.)

The aim of this study was to identify transcription factor (TF) binding sites and cis-regulatory elements (CREs) on the promoters of FvSPR1-like2 (SPIRAL) and FvSPT (SPATULA) genes in the woodland diploid strawberry (Fragaria vesca L.). We identified: (1) MYB59, WRKY25 and WRKY8 TFs which play a role in ethylene signaling; (2) ARF family of TFs which play a role in ARF-mediated auxin signaling on the promoter of FvSPR1-like2 gene; (3) ARR family of TFs which play a role in cytokinin signaling; (4) ERF family of TFs which play a role in ethylene signaling on the promoter of FvSPT. This bioinformatic analysis of TFs and CREs may provide a better understanding of the function of genes involved in, and the mechanism underlying, non-climateric ripening during strawberry fruit maturation