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Simultaneous VLBI observations of the SiO masers of the J = 1 → 0 rotational line in the v = 1 and v = 2 vibrational levels toward Mira variables are presented. Because SiO maser lines are formed deep in circumstellar envelopes they serve as a unique tool to study the innermost envelopes of evolved stars. Although the first interpretation of SiO maser emission was made in 1974, observational features are only partially explained by models which have been suggested since then. Positional coincidence of the J = 1 → 0 masers of v = 1 and v = 2 has been argued as a way to distinguish among the maser pumping models, but it requires simultaneous observations of the two lines using high resolution. We have developed the technique for such observations during the last few years and here we report successful results of our simultaneous observations of the SiO v = 1 and v = 2 J = 1 → 0 masers using the Very Long Baseline Array (VLBA). We discuss the pumping mechanism in terms of our observational results.
Twenty-two consecutive VLBI images of supernova 1993J in the galaxy M81 taken over 7 years show, in unprecedented detail, the dynamic evolution of the expanding radio shell of an exploded star. High precision astrometry using phase-referencing shows that the supernova expands isotropically, and that its geometric center has a formal proper motion of 190±110 km s−1 w.r.t. the core of M81. Systematic changes in the images most likely reflect a pattern of inhomogeneities in the medium left over from the progenitor star, or possibly instabilities in the expanding shell. As the shockfront sweeps up the medium, it is progressively decelerated, and after 7 years it has slowed to less than 1/2 its original expansion velocity. SN1993J is likely now entering the early stages of the adiabatic phase common in much older supernova remnants.
Twenty consecutive VLBI images of supernova 1993J in M81 from the time of explosion to the present show the dynamic evolution of the expanding radio shell of an exploded star. No clear sign of a pulsar nebula, expected to have a spectral luminosity 10 to 1,000 times larger than that of the Crab, has yet been seen. The upper limit on the brightness at 8.4 GHz in the center of the shell in one of the latest images is 0.15 mJy per beam of 0.4 mas2, corresponding to a spectral luminosity of that of the Crab. Any nebula that may have formed in the center is probably still obscured by the surrounding thermal matter with no substantial filamentation having yet occurred in the latter.
A method of improving image fidelity by using observations at multiple frequencies is described. We discuss the power and possible limitations of the technique. Results of narrow frequency range observations with MERLIN and global VLBI are presented. We conclude with a consideration of the possible future impact of this technique.
The public health burden of alcohol is unevenly distributed across the life course, with levels of use, abuse, and dependence increasing across adolescence and peaking in early adulthood. Here, we leverage this temporal patterning to search for common genetic variants predicting developmental trajectories of alcohol consumption. Comparable psychiatric evaluations measuring alcohol consumption were collected in three longitudinal community samples (N = 2,126, obs = 12,166). Consumption-repeated measurements spanning adolescence and early adulthood were analyzed using linear mixed models, estimating individual consumption trajectories, which were then tested for association with Illumina 660W-Quad genotype data (866,099 SNPs after imputation and QC). Association results were combined across samples using standard meta-analysis methods. Four meta-analysis associations satisfied our pre-determined genome-wide significance criterion (FDR < 0.1) and six others met our ‘suggestive’ criterion (FDR <0.2). Genome-wide significant associations were highly biological plausible, including associations within GABA transporter 1, SLC6A1 (solute carrier family 6, member 1), and exonic hits in LOC100129340 (mitofusin-1-like). Pathway analyses elaborated single marker results, indicating significant enriched associations to intuitive biological mechanisms, including neurotransmission, xenobiotic pharmacodynamics, and nuclear hormone receptors (NHR). These findings underscore the value of combining longitudinal behavioral data and genome-wide genotype information in order to study developmental patterns and improve statistical power in genomic studies.
This study introduces a special series on validity studies of the Cognition Battery (CB) from the U.S. National Institutes of Health Toolbox for the Assessment of Neurological and Behavioral Function (NIHTB) (Gershon, Wagster et al., 2013) in an adult sample. This first study in the series describes the sample, each of the seven instruments in the NIHTB-CB briefly, and the general approach to data analysis. Data are provided on test–retest reliability and practice effects, and raw scores (mean, standard deviation, range) are presented for each instrument and the gold standard instruments used to measure construct validity. Accompanying papers provide details on each instrument, including information about instrument development, psychometric properties, age and education effects on performance, and convergent and discriminant construct validity. One study in the series is devoted to a factor analysis of the NIHTB-CB in adults and another describes the psychometric properties of three composite scores derived from the individual measures representing fluid and crystallized abilities and their combination. The NIHTB-CB is designed to provide a brief, comprehensive, common set of measures to allow comparisons among disparate studies and to improve scientific communication. (JINS, 2014, 20, 1–12)
The partial excavation under rescue conditions in 1961–63 of the ditches and
interior of an enclosure of the earlier neolithic period is described. The
enclosure, covering a total area of approximately 2.4 ha, was defined by
double concentric interrupted ditches, which were for the most part
naturally filled. There were many traces of activity within the interior,
presumed to be contemporary with the ditches, including pits, gullies, post-
and stake-holes, and varying concentrations of struck and burnt flint and
pottery. Human burials were found. There is a little Ebbsfleet pottery in
secondary contexts and there are later prehistoric, Roman and medieval
finds. It is probably not possible to ascribe a single or specific role to
the site, which may have been important as a place where several activities
were concentrated, including occupation, subsistence, exchange, enclosure or
defence, burial and ritual.
We discuss recent measurements of proper motions of the hotspots of compact symmetric objects (CSOs). Source expansion has been detected in 10 CSOs so far and all these objects are very young (≤ 3 × 103 yr). In a few sources ages have also been estimated from energy supply and spectral ageing arguments and these estimates are comparable. This argues that these sources are close to equipartition and that standard spectral ageing models apply. Proper motion studies are now constraining hotspot accelerations, side-to-side motions, and differences in hotspot advance speeds between the two hotspots of a source. Although most CSOs are young sources their evolution is unclear. There is increasing evidence that in some objects the CSO structure represents a new phase of activity within a recurrent source.
Insurance accounting has for many years proved a challenging topic for standard setters, preparers and users, often described as a “black box”. Will recent developments, in particular the July 2010 Insurance Contracts Exposure Draft, herald a new era?
This paper reviews these developments, setting out key issues and implications. It concentrates on issues relevant to life insurers, although much of the content is also relevant to non-life insurers.
The paper compares certain IFRS and Solvency II developments, recognising that UK insurers face challenges in implementing new financial and regulatory reporting requirements in similar timeframes. The paper considers resulting external disclosure requirements and a possible future role for supplementary information.
There remains a lack of comprehensive pediatric emergency preparedness planning worldwide. A disaster or mass-casualty incident (MCI) involving pediatric patients could overwhelm existing pediatric resources within the New York City (NYC) metropolitan region. The NYC Department of Health and Mental Hygiene (DOHMH) recognizing the importance to plan for a MCI with a large number of pediatric victims, implemented a project (the Pediatric Disaster Coalition; PDC), to address gaps in the healthcare system to provide effective and timely pediatric care during a MCI.
The PDC includes experts in emergency preparedness, critical care, surgery, and emergency medicine from the NYC pediatric/children's hospitals, DOHMH, Office of Emergency Management, and Fire Department (FDNY). Two committees addressed pediatric prehospital triage, transport, and pediatric critical care (PCC) surge capacities. They developed guidelines and recommendations for pediatric field triage and transport, matching patients' needs to resources, and increasing PCC Surge Capacities.
Surge recommendations were formulated. The algorithm developed provides specific pediatric triage criteria that identify severity of illness using the traditional Red, Yellow, and Green categories plus an Orange designation for continual reassessments that has been adopted by FDNY that has trained > 3,000 FDNY EMS personnel in its use. Triaged patients can be transported to appropriate resources based on a tiered system that defines pediatric hospital capabilities. The Surge Committee has created PCC Surge Capacity Guideline that can be used by hospitals to create their individual PCC surge plans. 15 of 25 NYC hospitals with PCC capabilities are participating with PDC planning; 5 have completed surge plans, 3 are nea completion, and 7 are in development. The completed plans add 92 surge beds to 244 regularly available PICU beds. The goal is to increase the PCC surge bed capacity by 200 + beds.
The project is an effective, multidisciplinary group approach to planning for a regional, large-scale pediatric MCI. Regional lead agencies must emphasize pediatric emergency preparedness in their disaster plans.
Children frequently are the victims of disasters due to natural hazards or terrorist attacks. However, there is a lack of specific pediatric emergency preparedness planning worldwide. To address these gaps, the federal grant-funded New York City Pediatric Disaster Coalition (PDC) established guidelines for creating Pediatric Critical care (PCC) surge plans and assisted hospitals in creating their plans. To date, five hospitals completed plans, thereby adding 92 beds to surge capacity. On 01 May 2010, 18:00h, there was an attempt to detonate a car bomb in Times Square, a large urban attraction in the heart of New York City. The perpetrator was later convicted of the attempted use of a weapon of mass destruction. Had the bomb exploded, given the location and time of day, it is possible that many critically injured victims would have been children.
The unit director or a senior attending of nine major hospitals in the NYC area (five in close proximity and four at secondary sites) were surveyed for the number of their vacant pediatric critical care beds at the time of the event before activation of surge plans.
At the time the car bomb was discovered, the nine hospitals, which have a total of 141 PCC beds, had only 29 vacant approved pediatric critical care beds.
Had the event resulted in many pediatric casualties, the existing PCC vacant beds at these hospitals may not have satisfied the need. Activating surge plans at five of these hospitals would have added 92 to the 29 available PCC beds for a total of 121. In order to provide PCC to a large number of victims, it is crucial that hospitals prepare PCC surge plans.