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Molecular characterization of pediatric low-grade glioma (pLGG) over the last decade has identified recurrent alterations, most commonly involving BRAF, and less frequently other pathways including MYB and MYBL1. Many of these molecular markers have been exploited clinically to aid in diagnosis and treatment decisions. However, their frequency and prognostic significance remain unknown. Further, a significant portion of cases do not have any of these alterations and what underlies these cases remains unknown. To address this we compiled a cohort of 562 patients diagnosed at SickKids from 1990-2017. We identified molecular alterations in 454 cases (81% of the cohort). The most frequent events were those involving BRAF; either as fusions (most commonly with KIAA1549 (30%)) or V600E mutations (17%) and NF-1 (22%). Less frequently, we identified recurrent FGFR1 fusions and mutations (3%), MYB/MYBL alterations (2%), H3F3AK27M (2%) or IDH1R132H (0.5%) mutations, as well as other novel rare events. Survival analysis revealed significantly better progression-free survival (PFS) and overall survival (OS) of KIAA1549-BRAF fused patients compared to BRAFV600E with 10-year OS 97.7% (95%, CI 95.5-100) and 83.9% (95%, CI 72.5-95.6), respectively. In addition to survival, molecular alterations predicted differences in response to conventional therapeutics; BRAF fused patients showed a 46% response-rate, versus only 14% in V600E patients. pLGGs harboring H3F3AK27M progressed early with median PFS of 11 months. In patients with MYB/MYBL1, FGFR1/FGFR2 alterations, we observed only one death (FGFR1N546K case). The work here represents the largest cohort of pLGGs with molecular profiling and their impact on the clinical behaviour of the disease.
Phased Array Feed (PAF) technology is the next major advancement in radio astronomy in terms of combining high sensitivity and large field of view. The Focal L-band Array for the Green Bank Telescope (FLAG) is one of the most sensitive PAFs developed so far. It consists of 19 dual-polarization elements mounted on a prime focus dewar resulting in seven beams on the sky. Its unprecedented system temperature of ~17 K will lead to a 3 fold increase in pulsar survey speeds as compared to contemporary single pixel feeds. Early science observations were conducted in a recently concluded commissioning phase of the FLAG where we clearly demonstrated its science capabilities. We observed a selection of normal and millisecond pulsars and detected giant pulses from PSR B1937+21.
This study examines the interplay between individual and social–developmental factors in the development of positive functioning, substance use problems, and mental health problems. This interplay is nested within positive and negative developmental cascades that span childhood, adolescence, the transition to adulthood, and adulthood. Data are drawn from the Seattle Social Development Project, a gender-balanced, ethnically diverse community sample of 808 participants interviewed 12 times from ages 10 to 33. Path modeling showed short- and long-term cascading effects of positive social environments, family history of depression, and substance-using social environments throughout development. Positive family social environments set a template for future partner social environment interaction and had positive influences on proximal individual functioning, both in the next developmental period and long term. Family history of depression adversely affected mental health functioning throughout adulthood. Family substance use began a cascade of substance-specific social environments across development, which was the pathway through which increasing severity of substance use problems flowed. The model also indicated that adolescent, but not adult, individual functioning influenced selection into positive social environments, and significant cross-domain effects were found in which substance-using social environments affected subsequent mental health.
We present UBVRI photometry of the faint and highly erratic cataclysmic variable discovered by Hawkins (1983) from a sequence of U.K. Schmidt plates. Observations using the ANU 2.3 m telescope over two nights in September 1986 show pronounced and repeatable modulation at a binary period of 108.6 min. Dramatic colour differences are evident in the folded UBVRI light curves: in the U band, a single sinusoidal peak is present, while at longer wavelengths, a second red peak dominates at a phase separation of Δϕ = 0.5. This behaviour is strongly suggestive of cyclotron emission from two magnetic accretion funnels in an AM Herculis binary system. Furthermore, the binary period lies in the narrow range of 100-115 minutes that characterizes most of the AM Herculis variables lying on the short side of the 2-3 hour period gap. We conclude therefore that the object is almost certainly a new AM Herculis system, and develop a model in which the blue and red components originate from two non-diametrically opposed cyclotron regions that are characterized by differing electron temperatures and opacities. Predictions are made regarding the linear and circular polarization properties of this important new magnetic variable.
We have undertaken a study of the 3-D spatial distribution of the older (τ ≥ 1–2 Gyr) stellar population lying beyond ~ 2 kpc in projected radial distance from the centre of the SMC. The study will eventually cover 120 square degrees including six overlapping Schmidt fields. Here we present the results from an area of 80 square degrees including the western, northern and north-eastern outer parts of the SMC.
Cognitive and functional impairment increase risk for post-coronary artery bypass graft (CABG) surgery delirium (PCD), but how much impairment is necessary to increase PCD risk remains unclear.
The Neuropsychiatric Outcomes After Heart Surgery (NOAHS) study is a prospective, observational cohort study of participants undergoing elective CABG surgery. Pre-operative cognitive and functional status based on Clinical Dementia Rating (CDR) scale and neuropsychological battery are assessed. We defined mild cognitive impairment (MCI) based on either (1) CDR global score 0.5 (CDR-MCI) or (2) performance 1.5 SD below population means on any cognitive domain on neurocognitive battery (MCI-NC). Delirium was assessed daily post-operative day 2 through discharge using the confusion assessment method (CAM) and delirium index (DI). We investigate whether MCI – either definition – predicts delirium or delirium severity.
So far we have assessed 102 participants (mean age 65.1 ± 9; male: 75%) for PCD. Twenty six participants (25%) have MCI-CDR; 38 (62% of those completing neurocognitive testing) met MCI-NC criteria. Fourteen participants (14%) developed PCD. After adjusting for age, sex, comorbidity, and education, MCI-CDR, MMSE, and Lawton IADL score predicted PCD on logistic regression (OR: 5.6, 0.6, and 1.5, respectively); MCI-NC did not (OR [95% CI]: 11.8 [0.9, 151.4]). Using similarly adjusted linear regression, MCI-CDR, MCI-NC, CDR sum of boxes, MMSE, and Lawton IADL score predicted delirium severity (adjusted R2: 0.26, 0.13, 0.21, 0.18, and 0.32, respectively).
MCI predicts post-operative delirium and delirium severity, but MCI definition alters these relationships. Cognitive and functional impairment independently predict post-operative delirium and delirium severity.
We examined and described colonization of MRSA in the anterior nares and throat from 184 community-recruited injection drug users. Thirty-seven (20%) were positive for MRSA: most (34, 92%) were carriers in the nares; while only three (8%) were carriers detected by throat swabs alone. The majority (29, 78%) of MRSA isolates were PVL positive.
An extremely simple and inexpensive apparatus for preparation of the C60 and C70 fullerenes is described. An efficient separatory technique is described which implements a phenylglycine based HFLC column for preparation of high purity (99.99%) C60 and C70 samples. Treatment of C60 with osmium tetroxide and pyridine gives the osmate ester (2:1 adduct) and establishes that oxygen functionality can be added to C60 without disrupting the carbon framework. Raman spectroscopy of high purity C60 indicates that several lines previously not assigned to C60 (D.S.Bethune, G.Meijer, W.C.Tang, and H.J.Rosen, Chem.Phys.Lett.174, 219(1990)) are attributable to C60.
A three-dimensional Monte Carlo computer program is used to study the time-dependent coarsening of a precipitate population in a solid. The emphasis is on the influence of the escape rate of solute atoms from a precipitate on the coarsening behavior. Three models for the escape attempt frequency are compared. The time when coarsening is observed and the extent of coarsening depend on the model as does the percentage of solute precipitated in a given time. The qualitative results of the present calculations are compared with earlier findings.
In this paper we review the current understanding of laser-induced silicon thin film crystal growth on bulk amorphous substrates. We propose a model for oriented nucleation and show that the silicon reflectivity jump on melting coupled with radiant heating lead naturally to this autonucleation mechanism. We then survey various techniques for control of lateral epitaxial growth and conclude with the results of some recent electrical device characterization.
We demonstrate self-trapping of a two-dimensional beam at 1.3 microns wavelength in resonantly-enhanced InP. The self-trapped beam also induces a two-dimensional optical waveguide in bulk InP, which guides a second beam at 1.55 micron wavelength.
Uncertainties exist regarding the population risks of hospitalization due to pandemic influenza A(H1N1). Understanding these risks is important for patients, clinicians and policy makers. This study aimed to clarify these uncertainties. A national surveillance system was established for patients hospitalized with laboratory-confirmed pandemic influenza A(H1N1) in England. Information was captured on demographics, pre-existing conditions, treatment and outcomes. The relative risks of hospitalization associated with pre-existing conditions were estimated by combining the captured data with population prevalence estimates. A total of 2416 hospitalizations were reported up to 6 January 2010. Within the population, 4·7 people/100 000 were hospitalized with pandemic influenza A(H1N1). The estimated hospitalization rate of cases showed a U-shaped distribution with age. Chronic kidney disease, chronic neurological disease, chronic respiratory disease and immunosuppression were each associated with a 10- to 20-fold increased risk of hospitalization. Patients who received antiviral medication within 48 h of symptom onset were less likely to be admitted to critical care than those who received them after this time (adjusted odds ratio 0·64, 95% confidence interval 0·44–0·94, P=0·024). In England the risk of hospitalization with pandemic influenza A(H1N1) has been concentrated in the young and those with pre-existing conditions. By quantifying these risks, this study will prove useful in planning for the next winter in the northern and southern hemispheres, and for future pandemics.
The new Core-XAS (X-ray absorption spectroscopy) beamline (B18) at Diamond aims to provide a reliable spectrometer for a broad scientific community. With this in mind, B18 has been built as a general-purpose beamline and offers to users a variety of sample environments and detection methods. Here we will present the first commissioning results and some of the capabilities of this versatile instrument.
During the past decade, the number known shallow-amplitude, yet totally eclipsing, extreme-mass-ratio binaries has increased from one (AW UMa, which is now in doubt) to about a dozen. Statistics are accumulating that will tell us the nature of these once rare systems. These individual interacting field binaries are believed to be the progenitors of FK Comae-type fast-rotating subgiants, which are similar to the cluster stars called ‘variable blue stragglers.’ We review our recent observations and new analyses of the individual systems, V409 Hya, GSC 1283 0053 Ori, GSC 2537 520 CVn, using the 2007 Wilson Code and summarize results from our previous observations (V802 Aql, V902 Sgr) and those from the literature (e.g., CK Boo, GR Vir, HV Aqr, UY UMa, EM Pis, CU Tau, TV Mus) to disclose a preliminary picture of the character of this interesting class of binary stars.
This experiment sought to establish the response to increasing levels of coconut oil (CO) supplementation with a fixed 0·50:0·50 forage:concentrate diet on intake, digestibility and methane (CH4) emissions. Sixteen continental cross beef heifers (mean starting weight 481±36 kg) were assigned randomly to one of four levels of CO; 0 g/day, 125 g/day, 250 g/day or 375 g/day in an incomplete (three periods) multiple (no. =4) Latin-square design experiment (no. =12 per treatment). A linear reduction in CH4 output occurred as the level of CO in the diet increased ( P<0·001) with the greatest reduction at the 375 g/day level (394, 341, 314 and 240 l/day for animals fed 0, 125, 250 and 375 g/day CO, respectively). As the level of CO increased dry-matter (DM) intake (DMI) decreased, however these differences were only statistically significant at the 375 g/day level ( P <0·001). The proportional reduction in CH4 output was greater than the proportional reduction in DMI and hence CH4 l/kg DMI decreased from 39·8 l/kg when no CO was given to 29·7 l/kg when 375 g/day CO was given. The addition of CO to the diet resulted in a significant decline in dry-matter digestibility (DMD) at the 375 g/day level (P<0·05). These data demonstrate that the inclusion of CO at levels from 0·013 to 0·045 of the dietary DM within a 0·50:0·50 silage and concentrate ration reduces CH4 production with no adverse effect on DMI or DMD up to the 250 g/day level (0·027 of dietary DM).
Coral reefs are the most diverse shallow water marine ecosystem but in many parts of the world they are becoming degraded rapidly by a combination of human stresses and climate change (Birkeland, 1997 Wilkinson, this volume). Recent analyses suggest that at least 58% of corals reefs worldwide are directly threatened by human activities (Bryant et al., 1998). Major stressors impacting reef habitats include sediment and nutrient pollution from coastal development, land clearing and agriculture, over- fishing, pest and disease outbreaks, and global warming (Polunin and Roberts, 1996 Birkeland, 1997 Hoegh- Guldberg, 1999).
An estimated 20%of reefs have already been destroyed (Wilkinson, this volume), while less than a half of the 16% of reefs seriously damaged by global warming- induced increases in sea- surface temperatures in 1998 have recovered (Wilkinson, 2000). Where reefs are exposed to multiple stresses recovery could be slow or may not occur (Connell, 1997). In the Caribbean,; Gardner et al. (2003) have shown a region- wide decline in coral cover from 50% to 10% between 1977 and 2001. Spalding and Grenfell (1997) estimated that there are 20 000 km2 of reefs in the Caribbean, implying a loss of 8000 km2 of coral in 24 years, or 333 km2 of coral per year. Analyses of fossil records from the Caribbean suggest that recent reef degradation has been unprecedented over the last 100 000 years (Jackson et al., 2001 Wapnick et al., 2004 Precht and Aronson, this volume).
We have found photometric indications that Interacting Eclipsing Binaries of early to mid F spectral type (and possibly A) have strong magnetic activity which would arise from convective atmospheres. Light curve solutions and periodicity studies revealing spots, magnetic breaking and magnetic cycles are presented in XZ CMi, V965 Cyg and V963 Cyg.