9,423 research outputs found

    Authors' Response to Letter to the Editor

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98450/1/end%2E2012%2E1527.pd

    Long-term Outcomes of Immediate Versus Delayed Nephroureterectomy for Upper Tract Urothelial Carcinoma

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    Purpose: To compare immediate nephroureterectomy with delayed nephroureterectomy after a trial of nephron-sparing endoscopic surgery in patients who were treated initially at our institution from 1996 to 2004 for upper tract urothelial carcinoma. Patients were monitored for upper tract recurrences, metastases, cancer-specific and overall survival. Survival outcomes and perioperative measurements were compared between treatment groups. Results: Of 73 patients, 62 underwent immediate nephroureterectomy and 11 proceeded to nephroureterectomy after failed endoscopic management. Mean follow-up for all patients was 58 months and 75 months for patients who were alive at last follow-up. Patients treated initially with endoscopy averaged a surveillance procedure every 3.7 months and had a median delay to nephroureterectomy of 10 months. Perioperative measurements at time of nephroureterectomy did not differ between groups. Overall survival 5 years from initial resection in the delayed group and from nephroureterectomy in the immediate group was 64% and 59%, respectively; the corresponding 5-year cancer-specific and metastasis-free survival estimates were 91% vs 80% and 77% vs 73%, respectively (P>0.05). Pathologic progression from low to high-grade occurred in three of seven patients from the delayed group. Conclusions: Failure of endoscopic management necessitating nephroureterectomy does not appear to affect survival outcomes compared with immediate nephroureterectomy in patients with upper tract urothelial carcinoma. A trial of endoscopic management can be considered in patients with low-grade disease and a normal contralateral kidney. Endoscopy is a viable option when there are imperative indications for nephron sparing in the setting of high-grade disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90447/1/end-2E2011-2E0220.pd

    The Effect of Land Albedo on the Climate of Land-Dominated Planets in the TRAPPIST-1 System

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    Variations in the reflective properties of the bulk material that comprises the surface of land-dominated planets will affect the planetary energy balance by interacting differently with incident radiation from the host star. Furthermore, low-mass cool stars, such as nearby M8V dwarf TRAPPIST-1, emit a significant fraction of their flux in longer wavelengths relative to the Sun in regions where terrestrial materials may exhibit additional variability in albedo. Using the Community Earth System Model (CESM) we investigate the effect of the composition of the land surface and its albedo on planetary climate in the context of spatially homogeneous, entirely land-covered planets with dry atmospheres at the orbital separation of TRAPPIST-1d, TRAPPIST-1e, and TRAPPIST-1f. We use empirically derived spectra of four terrestrial compositional endmembers (granite, calcite, aridisol, and dune sand) and a composite spectrum of TRAPPIST-1 for these simulations and compare these model output to an aquaplanet and several Sol-spectrum control cases. We report a difference of approximately 50 K in global mean surface temperature, variations in atmospheric rotational features, and a reduction in cross-equatorial heat transport between scenarios in which materials with higher albedo in the infrared (calcite and dune sand) were used and those with more absorptive crustal material, such as granite or dry soils. An aquaplanet TRAPPIST-1d scenario results in an unstable runaway greenhouse regime. Therefore, we demonstrate that determining the composition and albedo of continental landmasses is crucial for making accurate determinations of the climate of terrestrial exoplanets.Comment: 18 pages, 11 figures. Accepted for publication in the Astrophysical Journal (ApJ

    Dispersal of thermophilic beetles across the intercontinental Arctic forest belt during the early Eocene

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    Abstract Massive biotic change occurred during the Eocene as the climate shifted from warm and equable to seasonal and latitudinally stratified. Mild winter temperatures across Arctic intercontinental land bridges permitted dispersal of frost-intolerant groups until the Eocene-Oligocene boundary, while trans-Arctic dispersal in thermophilic groups may have been limited to the early Eocene, especially during short-lived hyperthermals. Some of these lineages are now disjunct between continents of the northern hemisphere. Although Eocene climate change may have been one of the most important drivers of these ancient patterns in modern animal and plant distributions, its particular events are rarely implicated or correlated with group-specific climatic requirements. Here we explored the climatic and geological drivers of a particularly striking Neotropical-Oriental disjunct distribution in the rove beetle Bolitogyrus, a suspected Eocene relict. We integrated evidence from Eocene fossils, distributional and climate data, paleoclimate, paleogeography, and phylogenetic divergence dating to show that intercontinental dispersal of Bolitogyrus ceased in the early Eocene, consistent with the termination of conditions required by thermophilic lineages. These results provide new insight into the poorly known and short-lived Arctic forest community of the Early Eocene and its surviving lineages

    Neural correlates of eye contact and social function in autism spectrum disorder

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    Reluctance to make eye contact during natural interactions is a central diagnostic criterion for autism spectrum disorder (ASD). However, the underlying neural correlates for eye contacts in ASD are unknown, and diagnostic biomarkers are active areas of investigation. Here, neuroimaging, eye-tracking, and pupillometry data were acquired simultaneously using two-person functional near-infrared spectroscopy (fNIRS) during live "in-person" eye-to-eye contact and eye-gaze at a video face for typically-developed (TD) and participants with ASD to identify the neural correlates of live eye-to-eye contact in both groups. Comparisons between ASD and TD showed decreased right dorsal-parietal activity and increased right ventral temporal-parietal activity for ASD during live eye-to-eye contact (p≤0.05, FDR-corrected) and reduced cross-brain coherence consistent with atypical neural systems for live eye contact. Hypoactivity of right dorsal-parietal regions during eye contact in ASD was further associated with gold standard measures of social performance by the correlation of neural responses and individual measures of: ADOS-2, Autism Diagnostic Observation Schedule, 2nd Edition (r = -0.76, -0.92 and -0.77); and SRS-2, Social Responsiveness Scale, Second Edition (r = -0.58). The findings indicate that as categorized social ability decreases, neural responses to real eye-contact in the right dorsal parietal region also decrease consistent with a neural correlate for social characteristics in ASD

    The Spectra of T Dwarfs I: Near-Infrared Data and Spectral Classification

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    We present near-infrared spectra for a sample of T dwarfs, including eleven new discoveries made using the Two Micron All Sky Survey. These objects are distinguished from warmer (L-type) brown dwarfs by the presence of methane absorption bands in the 1--2.5 \micron spectral region. A first attempt at a near-infrared classification scheme for T dwarfs is made, based on the strengths of CH4_4 and H2_2O bands and the shapes of the 1.25, 1.6, and 2.1 \micron flux peaks. Subtypes T1 V through T8 V are defined, and spectral indices useful for classification are presented. The subclasses appear to follow a decreasing Teff_{eff} scale, based on the evolution of CH4_4 and H2_2O bands and the properties of L and T dwarfs with known distances. However, we speculate that this scale is not linear with spectral type for cool dwarfs, due to the settling of dust layers below the photosphere and subsequent rapid evolution of spectral morphology around Teff_{eff} \sim 1300--1500 K. Similarities in near-infrared colors and continuity of spectral features suggest that the gap between the latest L dwarfs and earliest T dwarfs has been nearly bridged. This argument is strengthened by the possible role of CH4_4 as a minor absorber shaping the K-band spectra of the latest L dwarfs. Finally, we discuss one peculiar T dwarf, 2MASS 0937+2931, which has very blue near-infrared colors (J-Ks_s = 0.89±-0.89\pm0.24) due to suppression of the 2.1 \micron peak. The feature is likely caused by enhanced collision-induced H2_2 absorption in a high pressure or low metallicity photosphere.Comment: 74 pages including 26 figures, accepted by ApJ v563 December 2001; full paper including all of Table 3 may be downloaded from http://www.gps.caltech.edu/~pa/adam/classification ;also see submission 010844

    OGFOD1 catalyzes prolyl hydroxylation of RPS23 and is involved in translation control and stress granule formation

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    2-Oxoglutarate (2OG) and Fe(II)-dependent oxygenase domain-containing protein 1 (OGFOD1) is predicted to be a conserved 2OG oxygenase, the catalytic domain of which is related to hypoxia-inducible factor prolyl hydroxylases. OGFOD1 homologs in yeast are implicated in diverse cellular functions ranging from oxygen-dependent regulation of sterol response genes (Ofd1, Schizosaccharomyces pombe) to translation termination/mRNA polyadenylation (Tpa1p, Saccharomyces cerevisiae). However, neither the biochemical activity of OGFOD1 nor the identity of its substrate has been defined. Here we show that OGFOD1 is a prolyl hydroxylase that catalyzes the posttranslational hydroxylation of a highly conserved residue (Pro-62) in the small ribosomal protein S23 (RPS23). Unusually OGFOD1 retained a high affinity for, and forms a stable complex with, the hydroxylated RPS23 substrate. Knockdown or inactivation of OGFOD1 caused a cell type-dependent induction of stress granules, translational arrest, and growth impairment in a manner complemented by wild-type but not inactive OGFOD1. The work identifies a human prolyl hydroxylase with a role in translational regulation
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