The Discovery of Two New Satellites of Pluto

Pluto's first known moon, Charon, was discovered in 1978 (Christy 1978) and has a diameter about half that of Pluto (Buie 1992,Young 1994, Sicardy 2005), which makes it larger relative to its primary than any other moon in the Solar System. Previous searches for other satellites around Pluto have been unsuccessful (Stern 1991, Stern 1994, Stern 2003), but they were not sensitive to objects <=150 km in diameter and there are no fundamental reasons why Pluto should not have more satellites (Stern 1994). Here we report the discovery of two additional moons around Pluto, provisionally designated S/2005 P1 (hereafter P1) and S/2005 P2 (hereafter P2), which makes Pluto the first Kuiper belt object (KBO) known to have multiple satellites. These new satellites are much smaller than Charon (diameter~1200 km), with P1 ranging in diameter from 60-165 km depending on the surface reflectivity, and P2 about 20% smaller than P1. Although definitive orbits cannot be derived, both new satellites appear to be moving in circular orbits in the same orbital plane as Charon, with orbital periods of ~38 days (P1) and ~25 days (P2). The implications of the discovery of P1 and P2 for the origin and evolution of the Pluto system, and for the satellite formation process in the Kuiper belt, are discussed in a companion paper (Stern 2006).Comment: Preprint of a paper accepted for publication in the journal Natur

Self-complementary AAV Virus (scAAV) Safe and Long-term Gene Transfer in the Trabecular Meshwork of Living Rats and Monkeys

AAV vectors produce stable transgene expression and elicit low immune response in many tissues. AAVs have been the vectors of choice for gene therapy for the eye, in particular the retina. scAAVs are modified AAVs that bypass the required second-strand DNA synthesis to achieve transcription of the transgene. The goal was to investigate the ability of AAV vectors to induce long-term, safe delivery of transgenes to the trabecular meshwork of living animals

Histological changes of the peripheral zone in small and large prostates and possible clinical implications

Jonathan A Guzman,1 Pranav Sharma,1 Lisa A Smith,1 John D Buie,2 Werner T de Riese1 1Department of Urology, Texas Tech University Health Sciences Center, Lubbock, TX, USA; 2Department of Pathology, Texas Tech University Health Sciences Center, Lubbock, TX, USA Introduction: It is well documented in literature that most prostate carcinomas (PCa) arise in the peripheral zone (PZ). Additionally, an inverse relationship between prostate size and the incidence of PCa has been demonstrated in recent studies. However, little is known about gland distribution in the peripheral zone of larger prostates compared to smaller prostates. In this study, we examined the histo-anatomical gland distribution within the peripheral zone in small and large prostates and discuss possible clinical implications. Methods: A semi-quantitative analysis of gland density and capsule thickness was performed using light microscopy on 10 large (&ge;80 g) prostate specimens and 10 small ( Results: Large prostates possessed a significantly lower mean gland count per field compared to small prostates (10.34&plusmn;4.15, n=50 vs 18.00&plusmn;5.41, n=50; t=8.16, df=49, P&lt;0.001). Additionally, large prostates showed a significantly higher average capsule thickness in millimeters compared to small prostates (1.80 mm, &plusmn;1.12 mm, n=30 vs 0.90 mm, &plusmn;0.56, n=30; t=8.16, df=49, P&lt;0.001). Conclusion: The results demonstrate that prostate hypertrophy leads to both decreased gland density in the peripheral zone and increased capsule thickness, suggesting that growth-induced expansion of the prostate against its capsule leads to compression-induced atrophy and fibrosis of glandular tissue within the peripheral zone (PZ). A decrease in gland density within the PZ may have clinical implications shedding light, for instance, on the reduction in PCa incidence in patients with large prostates as compared to smaller prostates, a phenomenon well documented in the literature. Keywords: prostate, adenocarcinoma, prostatic hyperplasia, peripheral zon

Observed glacier and volatile distribution on Pluto from atmosphere–topography processes

International audiencePluto has a variety of surface frosts and landforms as well as a complex atmosphere. There is ongoing geological activity related to the massive Sputnik Planitia glacier, mostly made of nitrogen (N2) ice mixed with solid carbon monoxide and methane, covering the 4-kilometre-deep, 1,000-kilometre-wide basin of Sputnik Planitia near the anti-Charon point. The glacier has been suggested to arise from a source region connected to the deep interior, or from a sink collecting the volatiles released planetwide. Thin deposits of N2 frost, however, were also detected at mid-northern latitudes and methane ice was observed to cover most of Pluto except for the darker, frost-free equatorial regions. Here we report numerical simulations of the evolution of N2, methane and carbon monoxide on Pluto over thousands of years. The model predicts N2 ice accumulation in the deepest low-latitude basin and the threefold increase in atmospheric pressure that has been observed to occur since 1988. This points to atmospheric-topographic processes as the origin of Sputnik Planitia’s N2 glacier. The same simulations also reproduce the observed quantities of volatiles in the atmosphere and show frosts of methane, and sometimes N2, that seasonally cover the mid- and high latitudes, explaining the bright northern polar cap reported in the 1990s and the observed ice distribution in 2015. The model also predicts that most of these seasonal frosts should disappear in the next decade

Gastrointestinal Problems in Children with Autism, Developmental Delays or Typical Development

OBJECTIVES: To compare GI problems among children with: 1) autism spectrum disorder (ASD), 2) developmental delay (DD) and 3) typical development (TD). METHODS: In 960 children from the CHildhood Autism Risks from Genetics and the Environment (CHARGE) study, we assessed GI symptom frequency. We examined scores on five Aberrant Behavior Checklist subscales comparing ASD children with high vs. low frequency GI symptoms. RESULTS: Compared to TD children, those with ASD (aOR 7.92[4.89–12.85]) and DD (aOR 4.55 [2.51–8.24]) were more likely to have at least one frequent GI symptom. Restricting to ASD children, those with frequent abdominal pain, gaseousness, diarrhea, constipation or pain on stooling scored worse on Irritability, Social Withdrawal, Stereotypy, and Hyperactivity compared with children having no frequent GI symptoms. CONCLUSIONS: Frequent GI problems affect young children with ASD and DD more commonly than those with TD. Maladaptive behaviors correlate with GI problems, suggesting these comorbidities require attention

Charon's light curves, as observed by New Horizons’ Ralph color camera (MVIC) on approach to the Pluto system

Light curves produced from color observations taken during New Horizons’ approach to the Pluto-system by its Multi-spectral Visible Imaging Camera (MVIC, part of the Ralph instrument) are analyzed. Fifty seven observations were analyzed, they were obtained between 9th April and 3rd July 2015, at a phase angle of 14.5° to 15.1°, sub-observer latitude of 51.2 °N to 51.5 °N, and a sub-solar latitude of 41.2°N. MVIC has four color channels; all are discussed for completeness but only two were found to produce reliable light curves: Blue (400–550 nm) and Red (540–700 nm). The other two channels, Near Infrared (780–975 nm) and Methane-Band (860–910 nm), were found to be potentially erroneous and too noisy respectively. The Blue and Red light curves show that Charon's surface is neutral in color, but slightly brighter on its Pluto-facing hemisphere. This is consistent with previous studies made with the Johnson B and V bands, which are at shorter wavelengths than that of the MVIC Blue and Red channel respectively