35 research outputs found
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The doubtful identity of fungus no. 517
Published in Proceedings of the American Wood Preservers' Association, 1937
First radial velocity results from the MINiature Exoplanet Radial Velocity Array (MINERVA)
The MINiature Exoplanet Radial Velocity Array (MINERVA) is a dedicated
observatory of four 0.7m robotic telescopes fiber-fed to a KiwiSpec
spectrograph. The MINERVA mission is to discover super-Earths in the habitable
zones of nearby stars. This can be accomplished with MINERVA's unique
combination of high precision and high cadence over long time periods. In this
work, we detail changes to the MINERVA facility that have occurred since our
previous paper. We then describe MINERVA's robotic control software, the
process by which we perform 1D spectral extraction, and our forward modeling
Doppler pipeline. In the process of improving our forward modeling procedure,
we found that our spectrograph's intrinsic instrumental profile is stable for
at least nine months. Because of that, we characterized our instrumental
profile with a time-independent, cubic spline function based on the profile in
the cross dispersion direction, with which we achieved a radial velocity
precision similar to using a conventional "sum-of-Gaussians" instrumental
profile: 1.8 m s over 1.5 months on the RV standard star HD 122064.
Therefore, we conclude that the instrumental profile need not be perfectly
accurate as long as it is stable. In addition, we observed 51 Peg and our
results are consistent with the literature, confirming our spectrograph and
Doppler pipeline are producing accurate and precise radial velocities.Comment: 22 pages, 9 figures, submitted to PASP, Peer-Reviewed and Accepte
Rapid testing versus karyotyping in Down's syndrome screening: cost-effectiveness and detection of clinically significant chromosome abnormalities
In all, 80% of antenatal karyotypes are generated by Down's syndrome screening programmes (DSSP). After a positive screening, women are offered prenatal foetus karyotyping, the gold standard. Reliable molecular methods for rapid aneuploidy diagnosis (RAD: fluorescence in situ hybridization (FISH) and quantitative fluorescence PCR (QF-PCR)) can detect common aneuploidies, and are faster and less expensive than karyotyping
The Euchromatic and Heterochromatic Landscapes Are Shaped by Antagonizing Effects of Transcription on H2A.Z Deposition
A role for variant histone H2A.Z in gene expression is now well established but little is known about the mechanisms by which it operates. Using a combination of ChIPâchip, knockdown and expression profiling experiments, we show that upon gene induction, human H2A.Z associates with gene promoters and helps in recruiting the transcriptional machinery. Surprisingly, we also found that H2A.Z is randomly incorporated in the genome at low levels and that active transcription antagonizes this incorporation in transcribed regions. After cessation of transcription, random H2A.Z quickly reappears on genes, demonstrating that this incorporation utilizes an active mechanism. Within facultative heterochromatin, we observe a hyper accumulation of the variant histone, which might be due to the lack of transcription in these regions. These results show how chromatin structure and transcription can antagonize each other, therefore shaping chromatin and controlling gene expression
DSIF and RNA Polymerase II CTD Phosphorylation Coordinate the Recruitment of Rpd3S to Actively Transcribed Genes
Histone deacetylase Rpd3 is part of two distinct complexes: the large (Rpd3L) and small (Rpd3S) complexes. While Rpd3L targets specific promoters for gene repression, Rpd3S is recruited to ORFs to deacetylate histones in the wake of RNA polymerase II, to prevent cryptic initiation within genes. Methylation of histone H3 at lysine 36 by the Set2 methyltransferase is thought to mediate the recruitment of Rpd3S. Here, we confirm by ChIPâChip that Rpd3S binds active ORFs. Surprisingly, however, Rpd3S is not recruited to all active genes, and its recruitment is Set2-independent. However, Rpd3S complexes recruited in the absence of H3K36 methylation appear to be inactive. Finally, we present evidence implicating the yeast DSIF complex (Spt4/5) and RNA polymerase II phosphorylation by Kin28 and Ctk1 in the recruitment of Rpd3S to active genes. Taken together, our data support a model where Set2-dependent histone H3 methylation is required for the activation of Rpd3S following its recruitment to the RNA polymerase II C-terminal domain
Pineoblastoma segregates into molecular sub-groups with distinct clinico-pathologic features: a Rare Brain Tumor Consortium registry study
Pineoblastomas (PBs) are rare, aggressive pediatric brain tumors of the pineal gland with modest overall survival despite intensive therapy. We sought to define the clinical and molecular spectra of PB to inform new treatment approaches for this orphan cancer. Tumor, blood, and clinical data from 91 patients with PB or supratentorial primitive neuroectodermal tumor (sPNETs/CNS-PNETs), and 2 pineal parenchymal tumors of intermediate differentiation (PPTIDs) were collected from 29 centres in the Rare Brain Tumor Consortium. We used global DNA methylation profiling to define a core group of PB from 72/93 cases, which were delineated into five molecular sub-groups. Copy number, whole exome and targeted sequencing, and miRNA expression analyses were used to evaluate the clinico-pathologic significance of each sub-group. Tumors designated as group 1 and 2 almost exclusively exhibited deleterious homozygous loss-of-function alterations in miRNA biogenesis genes (DICER1, DROSHA, and DGCR8) in 62 and 100% of group 1 and 2 tumors, respectively. Recurrent alterations of the oncogenic MYC-miR-17/92-RB1 pathway were observed in the RB and MYC sub-group, respectively, characterized by RB1 loss with gain of miR-17/92, and recurrent gain or amplification of MYC. PB sub-groups exhibited distinct clinical features: group 1â3 arose in older children (median ages 5.2â14.0 years) and had intermediate to excellent survival (5-year OS of 68.0â100%), while Group RB and MYC PB patients were much younger (median age 1.3â1.4 years) with dismal survival (5-year OS 37.5% and 28.6%, respectively). We identified age
Death and the Societies of Late Antiquity
Ce volume bilingue, comprenant un ensemble de 28 contributions disponibles en français et en anglais (dans leur version longue ou abrĂ©gĂ©e), propose dâĂ©tablir un Ă©tat des lieux des rĂ©flexions, recherches et Ă©tudes conduites sur le fait funĂ©raire Ă lâĂ©poque tardo-antique au sein des provinces de lâEmpire romain et sur leurs rĂ©gions limitrophes, afin dâouvrir de nouvelles perspectives sur ses Ă©volutions possibles. Au cours des trois derniĂšres dĂ©cennies, les transformations considĂ©rables des mĂ©thodologies dĂ©ployĂ©es sur le terrain et en laboratoire ont permis un renouveau des questionnements sur les populations et les pratiques funĂ©raires de lâAntiquitĂ© tardive, pĂ©riode marquĂ©e par de multiples changements politiques, sociaux, dĂ©mographiques et culturels. Lâapparition de ce qui a Ă©tĂ© initialement dĂ©signĂ© comme une « Anthropologie de terrain », qui fut le dĂ©but de la dĂ©marche archĂ©othanatologique, puis le rĂ©cent dĂ©veloppement dâapproches collaboratives entre des domaines scientifiques divers (archĂ©othanatologie, biochimie et gĂ©ochimie, gĂ©nĂ©tique, histoire, Ă©pigraphie par exemple) ont Ă©tĂ© dĂ©cisives pour le renouvellement des problĂ©matiques dâĂ©tude : rĂ©vision dâanciens concepts comme apparition dâaxes dâanalyse inĂ©dits. Les recherches rassemblĂ©es dans cet ouvrage sont articulĂ©es autour de quatre grands thĂšmes : lâĂ©volution des pratiques funĂ©raires dans le temps, lâidentitĂ© sociale dans la mort, les ensembles funĂ©raires en transformation (organisation et topographie) et les territoires de lâempire (du cĆur aux marges). Ces Ă©tudes proposent un rĂ©examen et une rĂ©vision des donnĂ©es, tant anthropologiques quâarchĂ©ologiques ou historiques sur lâAntiquitĂ© tardive, et rĂ©vĂšlent, Ă cet Ă©gard, une mosaĂŻque de paysages politiques, sociaux et culturels singuliĂšrement riches et complexes. Elles accroissent nos connaissances sur le traitement des dĂ©funts, lâemplacement des aires funĂ©raires ou encore la structure des sĂ©pultures, en rĂ©vĂ©lant une diversitĂ© de pratiques, et permettent au final de relancer la rĂ©flexion sur la maniĂšre dont les sociĂ©tĂ©s tardo-antiques envisagent la mort et sur les Ă©lĂ©ments permettant dâidentifier et de dĂ©finir la diversitĂ© des groupes qui les composent. Elles dĂ©montrent ce faisant que nous pouvons vĂ©ritablement apprĂ©hender les structures culturelles et sociales des communautĂ©s anciennes et leurs potentielles transformations, Ă partir de lâĂ©tude des pratiques funĂ©raires.This bilingual volume proposes to draw up an assessment of the recent research conducted on funerary behavior during Late Antiquity in the provinces of the Roman Empire and on their borders, in order to open new perspectives on its possible developments. The considerable transformations of the methodologies have raised the need for a renewal of the questions on the funerary practices during Late Antiquity, a period marked by multiple political, social, demographic and cultural changes. The emergence field anthropology, which was the beginning of archaeothanatology, and then the recent development of collaborative approaches between various scientific fields (archaeothanatology, biochemistry and geochemistry, genetics, history, epigraphy, for example), have been decisive. The research collected in this book is structured around four main themes: Evolution of funerary practices over time; Social identity through death; Changing burial grounds (organisation and topography); Territories of the Empire (from the heart to the margins). These studies propose a review and a revision of the data, both anthropological and archaeological or historical on Late Antiquity, and reveal a mosaic of political, social, and cultural landscapes singularly rich and complex. In doing so, they demonstrate that we can truly understand the cultural and social structures of ancient communities and their potential transformations, based on the study of funerary practices