674 research outputs found
Evaluation of a Water Channel-Based Platform for Characterizing Aerostat Flight Dynamics: A Case Study on a Lighter-Than-Air Wind Energy System
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140442/1/6.2014-2711.pd
RNA-Seq identifies SPGs as a ventral skeletal patterning cue in sea urchins
The sea urchin larval skeleton offers a simple model for formation of developmental patterns. The calcium carbonate skeleton is secreted by primary mesenchyme cells (PMCs) in response to largely unknown patterning cues expressed by the ectoderm. To discover novel ectodermal cues, we performed an unbiased RNA-Seq-based screen and functionally tested candidates; we thereby identified several novel skeletal patterning cues. Among these, we show that SLC26a2/7 is a ventrally expressed sulfate transporter that promotes a ventral accumulation of sulfated proteoglycans, which is required for ventral PMC positioning and skeletal patterning. We show that the effects of SLC perturbation are mimicked by manipulation of either external sulfate levels or proteoglycan sulfation. These results identify novel skeletal patterning genes and demonstrate that ventral proteoglycan sulfation serves as a positional cue for sea urchin skeletal patterning
In search of lost introns
Many fundamental questions concerning the emergence and subsequent evolution
of eukaryotic exon-intron organization are still unsettled. Genome-scale
comparative studies, which can shed light on crucial aspects of eukaryotic
evolution, require adequate computational tools.
We describe novel computational methods for studying spliceosomal intron
evolution. Our goal is to give a reliable characterization of the dynamics of
intron evolution. Our algorithmic innovations address the identification of
orthologous introns, and the likelihood-based analysis of intron data. We
discuss a compression method for the evaluation of the likelihood function,
which is noteworthy for phylogenetic likelihood problems in general. We prove
that after preprocessing time, subsequent evaluations take time almost surely in the Yule-Harding random model of -taxon
phylogenies, where is the input sequence length.
We illustrate the practicality of our methods by compiling and analyzing a
data set involving 18 eukaryotes, more than in any other study to date. The
study yields the surprising result that ancestral eukaryotes were fairly
intron-rich. For example, the bilaterian ancestor is estimated to have had more
than 90% as many introns as vertebrates do now
The impact of loco-regional recurrences on metastatic progression in early-stage breast cancer: a multistate model
To study whether the effects of prognostic factors associated with the occurrence of distant metastases (DM) at primary diagnosis change after the incidence of loco-regional recurrences (LRR) among women treated for invasive stage I or II breast cancer. The study population consisted of 3,601 women, enrolled in EORTC trials 10801, 10854, or 10902 treated for early-stage breast cancer. Data were analysed in a multivariate, multistate model by using multivariate Cox regression models, including a state-dependent covariate. The presence of a LRR in itself is a significant prognostic risk factor (HR: 3.64; 95%-CI: 2.02-6.5) for the occurrence of DM. Main prognostic risk factors for a DM are young age at diagnosis (</=40: HR: 1.79; 95%-CI: 1.28-2.51), larger tumour size (HR: 1.58; 95%-CI: 1.35-1.84) and node positivity (HR: 2.00; 95%-CI: 1.74-2.30). Adjuvant chemotherapy is protective for a DM (HR: 0.66; 95%-CI: 0.55-0.80). After the occurrence of a LRR the latter protective effect has disappeared (P = 0.009). The presence of LRR in itself is a significant risk factor for DM. For patients who are at risk of developing LRR, effective local control should be the main target of therapy
Le Forum, Vol. 41 No. 2
https://digitalcommons.library.umaine.edu/francoamericain_forum/1091/thumbnail.jp
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