A detailed description of the Halley-type Comet C/2001 OG108 (LONEOS) has been derived from visible, near-infrared, and mid-infrared observations obtained in October and November 2001. These data ...represent the first high- quality ground-based observations of a bare Halley-type comet nucleus and provide the best characterization of a Halley-type comet other than 1P/Halley itself. Analysis of time series photometry suggests that the nucleus has a rotation period of 57.2+/-0.5 h with a minimum nuclear axial ratio of 1.3, a phase-darkening slope parameter G of -0.01+/-0.10, and an estimated H=13.05+/-0.10. The rotation period of C/2001 OG108 is one of the longest observed among comet nuclei. The V-R color index for this object is measured to be 0.46+/-0.02, which is virtually identical to that of other cometary nuclei and other possible extinct comet candidates. Measurements of the comet's thermal emission constrain the projected elliptical nuclear radii to be 9.6+/-1.0 km and 7.4+/-1.0 km, which makes C/2001 OG108 one of the larger cometary nuclei known. The derived geometric albedo in V-band of 0.040+/- 0.010 is typical for comet nuclei. Visible-wavelength spectrophotometry and near-infrared spectroscopy were combined to derive the nucleus's reflectance spectrum over a 0.4 to 2.5 D*mm wavelength range. These measurements represent one of the few nuclear spectra ever observed and the only known spectrum of a Halley-type comet. The spectrum of this comet nucleus is very nearly linear and shows no discernable absorption features at a 5% detection limit. The lack of any features, especially in the 0.8 to 1.0 D*mm range such as are seen in the spectra of carbonaceous chondrite meteorites and many low-albedo asteroids, is consistent with the presence of anhydrous rather than hydrous silicates on the surface of this comet. None of the currently recognized meteorites in the terrestrial collections have reflectance spectra that match C/2001 OG108. The near-infrared spectrum, the geometric albedo, and the visible spectrophotometry all indicate that C/2001 OG108 has spectral properties analogous to the D-type, and possibly P-type asteroids. Comparison of the measured albedo and diameter of C/2001 OG108 with those of Damocloid asteroids reveals similarities between these asteroids and this comet nucleus, a finding which supports previous dynamical arguments that Damocloid asteroids could be composed of cometary-like materials. These observations are also consistent with findings that two Jupiter-family comets may have spectral signatures indicative of D-type asteroids. C/2001 OG108 probably represents the transition from a typical active comet to an extinct cometary nucleus, and, as a Halley-type comet, suggests that some comets originating in the Oort cloud can become extinct without disintegrating. As a near-Earth object, C/2001 OG108 supports the suggestion that some fraction of the near-Earth asteroid population consists of extinct cometary nuclei.
The Uranian rings were discovered serendipitously on 10 March 1977 during a stellar occultation (Elliot et al., 1977a; Millis et al., 1977), and a rich set of subsequent Earth-based occultations ...revealed that these narrow and sharp-edged rings were eccentric and inclined, precessing under the gravitational influence of the oblate central planet. Considerable progress has been made in understanding the observed characteristics of narrow rings and sharp edges (Nicholson et al., 2018) and their associated dynamics (Longaretti, 2018), but ever since their discovery, the Uranian rings have posed dynamical puzzles that resist simple explanations. The observational basis to address these questions for the Uranus system rests largely on occultation measurements of the narrow rings spanning nearly 30 years, beginning in 1977 and concluding most recently in 2006. Nearly all of these occultation data sets are available in digital form on NASA’s Planetary Data System (PDS) Ring-Moon Systems node, but many of them have not been previously published or described in detail. This paper serves as a guide to the PDS archive and provides essential information about the observations and the methods used to determine the ring widths, mean optical depths, and occultation event times from individual occultation profiles. Additional detail is provided in the Supplementary Online Material accompanying this publication. In a companion paper (French et al., 2023b), we make use of these observations to determine the Uranus ring orbits, pole direction, and gravity field, and the orbital characteristics and masses of three small Uranian moons – Cressida, Ophelia, and Cordelia – from their forced normal modes on the rings.
•All Uranus ring occultation observations from 1977–2006 are documented.•These data are available on the NASA Planetary Data System Ring-Moon Systems node.
We previously reported prevention of urolithiasis and associated rat urinary bladder tumors by urine acidification (via diet acidification) in male rats treated with the dual peroxisome ...proliferator-activated receptor (PPAR)α/γ agonist muraglitazar. Because urine acidification could potentially alter PPAR signaling and/or cellular proliferation in urothelium, we evaluated urothelial cell PPARα, PPARδ, PPARγ, and epidermal growth factor receptor (EGFR) expression, PPAR signaling, and urothelial cell proliferation in rats fed either a normal or an acidified diet for 5, 18, or 33 days. A subset of rats in the 18-day study also received 63 mg/kg of the PPARγ agonist pioglitazone daily for the final 3 days to directly assess the effects of diet acidification on responsiveness to PPARγ agonism. Urothelial cell PPARα and γ expression and signaling were evaluated in the 18- and 33-day studies by immunohistochemical assessment of PPAR protein (33-day study only) and quantitative real-time polymerase chain reaction (qRT-PCR) measurement of PPAR-regulated gene expression. In the 5-day study, EGFR expression and phosphorylation status were evaluated by immunohistochemical staining and
egfr and
akt2 mRNA levels were assessed by qRT-PCR. Diet acidification did not alter PPARα, δ, or γ mRNA or protein expression, PPARα- or γ-regulated gene expression, total or phosphorylated EGFR protein,
egfr or
akt2 gene expression, or proliferation in urothelium. Moreover, diet acidification had no effect on pioglitazone-induced changes in urothelial PPARγ-regulated gene expression. These results support the contention that urine acidification does not prevent PPARγ agonist-induced bladder tumors by altering PPARα, γ, or EGFR expression or PPAR signaling in rat bladder urothelium.
Diabetes (DM) is a major contributor to risk for hospital readmission. The Diabetes Early Readmission Risk Indicator (DERRI) is a predictor of 30-day readmission in patients with DM that may allow ...early identification and intervention for high-risk patients. A limitation to DERRI is the absence of DM-specific factors as contributors to this risk. To address this, we investigated HbA1c, glycemic measures and variability (GV), changes in DM therapy at discharge, and patient responses to a novel post-discharge questionnaire directed at Patient Comprehension (PC) of instructions provided for home DM management. Non-critically ill adult patients with DM were contacted by phone within 48 hours of hospital discharge to complete the PC Questionnaire. To date, 70 subjects (type 1 n=9, type 2 n=53, pancreatogenic DM n=8) (mean age 57.2 ± 12.8 years, BMI 31 ± 8.8 kg/m2, 56% men, 71% Caucasian, HbA1c 8.6 ± 2.0%, DM duration 19 ± 12 years, mean BG prior to discharge (210 ± 49 mg/dL), GV (66 ± 35 mg/dl) have been recruited. Of 41 subjects completing the PC questionnaire, those reporting that discharge instructions for home DM management were not provided had lower PC scores (70.6% vs. 81.5%, p=0.025) and more readmissions (OR 5.6, p=0.04) than those reporting that instructions were given. Among the 60 subjects with one-month post-discharge data, 22 patients (37%) reporting ≥1 readmission had higher DERRI scores than those without readmissions (26% vs. 20%, p=0.023). HbA1c, GV and changes in DM treatment regimens were not associated with readmission.
In summary, these results demonstrate that PC of discharge instructions may be a novel mediator of readmission risk and may add an additional measure of risk for hospital readmission.
Disclosure
J. Swami: None. A. Donihi: None. E. Karslioglu French: None. K. Delisi: None. D.S. Hlasnik: None. N. Patel: None. D. Pinkhasova: None. D.J. Rubin: Research Support; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc. M.T. Korytkowski: Advisory Panel; Self; Novo Nordisk Inc.. Other Relationship; Self; JAEB Center For Health Research.
A population-based case-control study in Utah of 358 cases diagnosed with prostate cancer between 1984 and 1985, and 679 controls categorically matched by age and county of residence, were ...interviewed to investigate the association between dietary intake of energy (kcal), fat, protein, vitamin A, β-carotene, vitamin C, zinc, cadmium, selenium, and prostate cancer. Dietary data were ascertained using a quantitative food-frequency questionnaire. Data were analyzed separately by age (45-67, 68-74) and by tumor aggressiveness. The most significant associations were seen for older males and aggressive tumors. Dietary fat was the strongest risk factor for these males, with an odds ratio (OR) of 2.9 (95 percent confidence interval CI 1.0-8.4) for total fat; OR = 2.2 (CI = 0.7-6.6) for saturated fat; OR = 3.6 (CI = 1.3-9.7) for monounsaturated fat; and OR = 2.7 (CI = 1.1-6.8) for polyunsaturated fat. Protein and carbohydrates had positive but nonsignificant associations. Energy intake had an OR of 2.5 (CI = 1.0-6.5). In these older men, no effects were seen for dietary cholesterol, body mass, or physical activity. There was little association between prostate cancer and dietary intake of zinc, cadmium, selenium, vitamin C, and β-carotene. Total vitamin A had a slight positive association with all prostate cancer (OR = 1.6, CI = 0.9-2.4), but not with aggressive tumors. No associations were found in younger males, with the exception of physical activity which showed active males to be at an increased but nonsignificant risk for aggressive tumors (OR = 2.0, CI = 0.8-5.2) and β-carotene which showed a nonsignificant protective effect (OR = 0.6, CI = 0.3-1.6). The findings suggest that dietary intake, especially fats, may increase risk of aggressive prostate tumors in older males.
Screening programs relying primarily on physical examination techniques for the early detection and treatment of congenital hip abnormalities have not been as consistently successful as expected. ...Since the 1980s, increased attention has been given to ultrasound imaging of the hip in young infants (less than five months of age) as a possible tool for improving patient outcomes. Although ultrasound examination may not provide advantages over careful repeated physician examination for universal screening, a growing body of evidence indicates that ultrasound surveillance of mild abnormalities can reduce the need for bracing without worsening outcomes. Radiographic documentation of hip normality after the femoral nucleus of ossification has appeared (at three to five month of age) is still appropriate to rule out hip dysplasia.
Summary The discovery of somatic mutations in the gene encoding isocitrate dehydrogenase-1 (IDH1) in glioblastomas was remarkable because the enzyme was not previously identified with any known ...oncogenic pathway. IDH1 is mutated in up to 75% of grade II and grade III diffuse gliomas. Apart from acute myeloid leukaemia, other tumour types do not carry IDH1 mutations. Mutations in a homologous gene, IDH2 , have also been identified, although they are much rarer. Although TP53 mutations and 1p/19q codeletions are mutually exclusive in gliomas, in both of these genotypes IDH1 mutations are common. IDH1 and IDH2 mutations are early events in the development of gliomas. Moreover, IDH1 and IDH2 mutations are a major prognostic marker for overall and progression-free survival in grade II–IV gliomas. Mutated IDH1 has an altered catalytic activity that results in the accumulation of 2-hydroxyglutarate. Molecularly, IDH1 and IDH2 mutations are heterozygous, affect only a single codon, and rarely occur together. Because IDH1 does not belong to a traditional oncogenic pathway and is specifically and commonly mutated in gliomas, the altered enzymatic activity of IDH1 may provide a fundamentally new understanding of diffuse glioma.
