211 research outputs found
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
Maintaining Information Dominance in Complex Environments
There are many risks to the U.S. Army’s command and control (C2) operations and to its intelligence and information warfare (IW) capabilities. The challenges include: significant uncertainty; sudden unexpected events; high noise and clutter levels in intelligence pictures; basic and complex deceptions exercised through a variety of channels; the actions of hidden malign actors; and novel forms of attack on U.S. and allied command, control, communications, computers, information/intelligence, surveillance, targeting acquisition, and reconnaissance (C4ISTAR) systems. If the U.S. Army is to secure and maintain information dominance in all environments, it must exploit complexity and uncertainty in the battlespace and not simply seek to overcome it. Innovation requires that new ideas are considered, and that old ideas should be robustly challenged. To achieve and maintain information dominance, the U.S. Army will also require a significant injection of innovation, a robust and resilient C2 and intelligence capability, novel technologies and an accelerated information operations capability development program that is broad, deep, sustained and well-coordinated. Furthermore, once information dominance is achieved, maintaining it will demand continuous change and development.https://press.armywarcollege.edu/monographs/1390/thumbnail.jp
Pharmacotherapy for Chronic Insomnia: A Brief Survey of PCP Attitudes and Preferences
Purpose: To examine primary care professionals (PCP) attitudes and prescribing preferences toward hypnotic medications to treat chronic insomnia. Methods: An online survey was sent to members of the Dartmouth CO-OP, a practice-based primary care research network in Maine, Vermont, and New Hampshire. The survey begins with a case vignette of a 64-year old woman suffering from chronic insomnia. Clinicians were then presented with eight questions about management of the patient and their attitudes toward prescribing medications, focusing on benzodiazepines/benzodiazepine receptor agonists (BDZ/BZRAs). Results: 103 of 198 clinicians (52%) responded. Regarding choice of medication for the case vignette, 80% of respondents preferred the off-label use of hypnotics such as trazodone or melatonin; 11% stated they would choose BDZs and 21% would choose BZRAs. Strong majorities expressed that negative consequences would occur with use of BDZ/BZRAs, including tolerance (77%), dependence (68%), other side effects (53%), and addiction (51%). PCP preference for off- label prescribing was correlated to levels of concern about harms (addiction, dependence, tolerance, side effects) of BDZ/BZRAs as measured on a global medication risk score in this survey. In addition, 14% of respondents felt that pharmacotherapy was not an appropriate therapeutic option for chronic insomnia in the case vignette. Conclusion: Most of the clinicians surveyed acknowledged a legitimate role for hypnotic medications in chronic insomnia but expressed reservations toward BDZ/BZRAs despite their FDA approval and proven efficacy. There appears to be a gap between published guidelines for selection of sedative-hypnotic medications and PCP preferences
Valence-dependent influence of serotonin depletion on model-based choice strategy.
Human decision-making arises from both reflective and reflexive mechanisms, which underpin goal-directed and habitual behavioural control. Computationally, these two systems of behavioural control have been described by different learning algorithms, model-based and model-free learning, respectively. Here, we investigated the effect of diminished serotonin (5-hydroxytryptamine) neurotransmission using dietary tryptophan depletion (TD) in healthy volunteers on the performance of a two-stage decision-making task, which allows discrimination between model-free and model-based behavioural strategies. A novel version of the task was used, which not only examined choice balance for monetary reward but also for punishment (monetary loss). TD impaired goal-directed (model-based) behaviour in the reward condition, but promoted it under punishment. This effect on appetitive and aversive goal-directed behaviour is likely mediated by alteration of the average reward representation produced by TD, which is consistent with previous studies. Overall, the major implication of this study is that serotonin differentially affects goal-directed learning as a function of affective valence. These findings are relevant for a further understanding of psychiatric disorders associated with breakdown of goal-directed behavioural control such as obsessive-compulsive disorders or addictions.This research was funded by Wellcome Trust Grants awarded to VV (Intermediate WT Fellowship) and Programme Grant (089589/Z/09/Z) awarded to TWR, BJE, ACR, JWD and BJS. It was conducted at the Behavioural and Clinical Neuroscience Institute, which is supported by a joint award from the Medical Research Council and Wellcome Trust (G00001354). YW was supported by the Fyssen Foundation. SP is supported by Marie Curie Intra-European Fellowship (FP7-People-2012-IEF).This is the final version of the article. It first appeared from NPG via http://dx.doi.org/10.1038/mp.2015.4
Estimation of State-of-Charge and Capacity of Used Lithium-Ion Cells
We describe an approach to estimate state-of-charge and faded capacity of cobalt-based lithium-ion cell based on timedomain analysis of a short-term transient. This approach requires a relatively short-duration test and is suitable for repurposing cells for less demanding applications. The successful estimation requires previous characterization of the cells for the given family because lithium ion chemistries differ significantly. Two algorithms were considered for estimation of unknown state-of-charge and capacity: Bayesian inference and boosted regression trees. The achieved accuracy was 95 % of capacity estimations; estimations were within 2 % of the nominal cell capacity from the true value
Cell bank characterization and fermentation optimization for production of recombinant heavy chain C-terminal fragment of botulinum neurotoxin serotype E (rBoNTE(H\u3csub\u3ec\u3c/sub\u3e): Antigen E) by \u3ci\u3ePichia pastoris\u3c/i\u3e
A process was developed for production of a candidate vaccine antigen, recombinant C-terminal heavy chain fragment of the botulinum neurotoxin serotype E, rBoNTE(Hc)in Pichia pastoris. P. pastoris strain GS115 was transformed with the rBoNTE(Hc) gene inserted into pHILD4 Escherichia coli—P. pastoris shuttle plasmid. The clone was characterized for genetic stability, copy number, and BoNTE(Hc) sequence. Expression of rBoNTE(Hc) from the Mut+ HIS4 clone was confirmed in the shake-flask, prior to developing a fed-batch fermentation process at 5 and 19 L scale. The fermentation process consists of a glycerol growth phase in batch and fed-batch mode using a defined medium followed by a glycerol/methanol transition phase for adaptation to growth on methanol and a methanol induction phase resulting in the production of rBoNTE(Hc). Specific growth rate, ratio of growth to induction phase, and time of induction were critical for optimal rBoNTE(Hc) production and minimal proteolytic degradation. A computer-controlled exponential growth model was used for process automation and off-gas analysis was used for process monitoring. The optimized process had an induction time of 9 h on methanol and produced up to 3 mg of rBoNTE(Hc) per gram wet cell mass as determined by HPLC and Western blot analysis
Cell bank characterization and fermentation optimization for production of recombinant heavy chain C-terminal fragment of botulinum neurotoxin serotype E (rBoNTE(H\u3csub\u3ec\u3c/sub\u3e): Antigen E) by \u3ci\u3ePichia pastoris\u3c/i\u3e
A process was developed for production of a candidate vaccine antigen, recombinant C-terminal heavy chain fragment of the botulinum neurotoxin serotype E, rBoNTE(Hc)in Pichia pastoris. P. pastoris strain GS115 was transformed with the rBoNTE(Hc) gene inserted into pHILD4 Escherichia coli—P. pastoris shuttle plasmid. The clone was characterized for genetic stability, copy number, and BoNTE(Hc) sequence. Expression of rBoNTE(Hc) from the Mut+ HIS4 clone was confirmed in the shake-flask, prior to developing a fed-batch fermentation process at 5 and 19 L scale. The fermentation process consists of a glycerol growth phase in batch and fed-batch mode using a defined medium followed by a glycerol/methanol transition phase for adaptation to growth on methanol and a methanol induction phase resulting in the production of rBoNTE(Hc). Specific growth rate, ratio of growth to induction phase, and time of induction were critical for optimal rBoNTE(Hc) production and minimal proteolytic degradation. A computer-controlled exponential growth model was used for process automation and off-gas analysis was used for process monitoring. The optimized process had an induction time of 9 h on methanol and produced up to 3 mg of rBoNTE(Hc) per gram wet cell mass as determined by HPLC and Western blot analysis
The properties of the 2175AA extinction feature discovered in GRB afterglows
The unequivocal, spectroscopic detection of the 2175 bump in extinction
curves outside the Local Group is rare. To date, the properties of the bump
have been examined in only two GRB afterglows (GRB 070802 and GRB 080607). In
this work we analyse in detail the detections of the 2175 extinction bump in
the optical spectra of the two further GRB afterglows: GRB 080605 and 080805.
We gather all available optical/NIR photometric, spectroscopic and X-ray data
to construct multi-epoch SEDs for both GRB afterglows. We fit the SEDs with the
Fitzpatrick & Massa (1990) model with a single or broken PL. We also fit a
sample of 38 GRB afterglows, known to prefer a SMC-type extinction curve, with
the same model. We find that the SEDs of GRB 080605 and GRB 080805 at two
epochs are fit well with a single PL with a derived extinction of A_V =
0.52(+0.13 -0.16) and 0.50 (+0.13 -0.10), and 2.1(+0.7-0.6) and 1.5+/-0.2
respectively. While the slope of the extinction curve of GRB 080805 is not
well-constrained, the extinction curve of GRB 080605 has an unusual very steep
far-UV rise together with the 2175 bump. Such an extinction curve has
previously been found in only a small handful of sightlines in the MW. One
possible explanation of such an extinction curve may be dust arising from two
different regions with two separate grain populations, however we cannot
distinguish the origin of the curve. We finally compare the four 2175 bump
sightlines to the larger GRB afterglow sample and to Local Group sightlines. We
find that while the width and central positions of the bumps are consistent
with what is observed in the Local Group, the relative strength of the detected
bump (A_bump) for GRB afterglows is weaker for a given A_V than for almost any
Local Group sightline. Such dilution of the bump strength may offer tentative
support to a dual dust-population scenario.Comment: 9 pages, 8 figures, 3 tables, accepted to Ap
Skunk River Review September 1990, vol 2
https://openspace.dmacc.edu/skunkriver/1005/thumbnail.jp
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