1,203 research outputs found
Reexposure to the amnestic agent alleviates Cycloheximide induced retrograde amnesia for reactivated and extinction memories
We investigated whether reexposure to an amnestic agent would reverse amnesia for extinction of learned fear similar to that of a reactivated memory. When cycloheximide (CHX) was administered immediately after a brief cue-induced memory reactivation (15 sec) and an extended extinction session (12 min) rats showed retrograde amnesia for both memories. CHX did not produce amnesia for a moderate extinction session (6 min). Re-administering CHX before testing reversed the amnestic effect for both memories (i.e., the memories were recovered). These results are discussed using a modified state dependent model of retrograde amnesia
Transfer of memory retrieval cues attenuates the context specificity of latent inhibition
Previous studies have demonstrated that the transfer of retrieval cues for original acquisition memories, old \u27reactivatedâ memories, and extinction memories attenuated the context shift effect. This study examined whether latent inhibition (CS preexposure) cues would also transfer, thus alleviating the context specificity. Rats preexposed to a particular context were immediately exposed to a different, novel context. When these rats were trained and tested in the shifted context following preexposure/exposure they showed the latent inhibition effect, i.e., retarded learning in the context that differed from preexposure. That the rats treated the shifted context as the preexposure context demonstrates that the preexposure retrieval cues transferred. These results are consistent with other findings that a novel context can serve as retrieval cues for an event learned in a different setting
Performance Measures Using Electronic Health Records: Five Case Studies
Presents the experiences of five provider organizations in developing, testing, and implementing four types of electronic quality-of-care indicators based on EHR data. Discusses challenges, and compares results with those from traditional indicators
The Australian Cancer Anaemia Survey: a snapshot of anaemia in adult patients with cancer
The document attached has been archived with permission from the editor of the Medical Journal of Australia (09 January 2008). An external link to the publisherâs copy is included.Objective: To evaluate the frequency and management of anaemia in Australian adults with solid and haematological malignancies. Design: 6-month observational, prospective, multicentre study. Participants: 694 patients recruited from outpatient oncology clinics in 24 hospitals in five Australian states between 9 April 2001 and 31 July 2001. Main outcome measures: Frequency of anaemia (haemoglobin [Hb] level < 120 g/L) at enrolment and over ensuing 6 months, by tumour type, disease status and cancer treatment; anaemia treatment and âtriggerâ Hb level for this treatment. Results: Participants had median age 60 years, and 61% were women. Prevalence of anaemia at enrolment was 35% (199/562), with 78% of these 199 having mild anaemia (Hb, 100â119 g/L). Frequency of anaemia (either present at enrolment or developing during the study) was 57% overall (323/566), and varied with tumour type, from 49% (lymphoma/myeloma) to 85% (urogenital cancer). Patients who received radiotherapy either in combination or concomitant with chemotherapy were more likely to have anaemia (73%) than those receiving chemotherapy alone (58%) (P = 0.004). Of all chemotherapy patients not anaemic at enrolment, 23% developed anaemia by the second monthly follow-up. Independent predictors for anaemia in chemotherapy patients were low baseline Hb level (odds ratio [OR], 5.4; 95% CI, 2.7â10.9) and use of platinum chemotherapeutic agents (OR, 4.8; 95% CI, 2.1â11.4) (P < 0.001). Anaemia was treated in 41% of patients with anaemia at enrolment â by transfusion (36%), iron (5%) and erythropoietic agents (2%). Frequency of anaemia treatment varied between tumour types, from 19% (breast cancer) to 60% (leukaemia). The mean âtrigger Hbâ for initiating transfusion was 95 g/L. Conclusions: Anaemia is prevalent among Australian patients with cancer managed in hospital oncology units. Its management varies between tumour types. Many patients do not receive treatment for their anaemia.Tara Seshadri, H Miles Prince, David R Bell, Paul B Coughlin, Philip P B James, Gary E Richardson, Boris Chern, Peter Briggs, John Norman, Ian N Olver, Chris Karapetis and John Stewart, for the Australia Cancer Anaemia Study (ACAS) Grou
The Lyman-alpha Forest Power Spectrum from the Sloan Digital Sky Survey
We measure the power spectrum, P_F(k,z), of the transmitted flux in the
Ly-alpha forest using 3035 high redshift quasar spectra from the Sloan Digital
Sky Survey. This sample is almost two orders of magnitude larger than any
previously available data set, yielding statistical errors of ~0.6% and ~0.005
on, respectively, the overall amplitude and logarithmic slope of P_F(k,z). This
unprecedented statistical power requires a correspondingly careful analysis of
the data and of possible systematic contaminations in it. For this purpose we
reanalyze the raw spectra to make use of information not preserved by the
standard pipeline. We investigate the details of the noise in the data,
resolution of the spectrograph, sky subtraction, quasar continuum, and metal
absorption. We find that background sources such as metals contribute
significantly to the total power and have to be subtracted properly. We also
find clear evidence for SiIII correlations with the Ly-alpha forest and suggest
a simple model to account for this contribution to the power. While it is
likely that our newly developed analysis technique does not eliminate all
systematic errors in the P_F(k,z) measurement below the level of the
statistical errors, our tests indicate that any residual systematics in the
analysis are unlikely to affect the inference of cosmological parameters from
P_F(k,z). These results should provide an essential ingredient for all future
attempts to constrain modeling of structure formation, cosmological parameters,
and theories for the origin of primordial fluctuations.Comment: 92 pages, 45 of them figures, submitted to ApJ, data available at
http://feynman.princeton.edu/~pmcdonal/LyaF/sdss.htm
The High-Density Ionized Gas in the Central Parsecs of the Galaxy
We report the results from observations of H30 line emission in Sgr A
West with the Submillimeter Array at a resolution of 2\arcsec and a field of
view of about 40\arcsec. The H30 line is sensitive to the high-density
ionized gas in the minispiral structure. We compare the velocity field obtained
from H30 line emission to a Keplerian model, and our results suggest
that the supermassive black hole at Sgr A* dominates the dynamics of the
ionized gas. However, we also detect significant deviations from the Keplerian
motion, which show that the impact of strong stellar winds from the massive
stars along the ionized flows and the interaction between Northern and Eastern
arms play significant roles in the local gas dynamics.Comment: 4 pages, 2 figure
The Discovery of New Galaxy Members in the NGC 5044 and NGC 1052 Groups
We present the results of neutral hydrogen (HI) observations of the NGC 5044
and NGC 1052 groups, as part of a GEMS (Group Evolution Multiwavelength Study)
investigation into the formation and evolution of galaxies in nearby groups.
Two new group members have been discovered during a wide-field HI imaging
survey conducted using the ATNF Parkes telescope. These results, as well as
those from followup HI synthesis and optical imaging, are presented here.
J1320-1427, a new member of the NGC 5044 Group, has an HI mass of
M_HI=1.05e9Msun and M_HI/L_B=1.65 Msun/Lsun, with a radial velocity of
v=2750km/s. The optical galaxy is characterised by two regions of star
formation, surrounded by an extended, diffuse halo. J0249-0806, the new member
of the NGC 1052 Group, has M_HI=5.4e8Msun, M_HI/L_R=1.13 Msun/Lsun and
v=1450km/s. The optical image reveals a low surface brightness galaxy. We
interpret both of these galaxies as irregular type, with J0249-0806 possibly
undergoing first infall into the NGC 1052 group.Comment: Accepted for publication in MNRAS. 21 pages, 13 figures. Also
available with high-resolution figures at
http://www.astro.livjm.ac.uk/~npfm/Papers/mmb04.ps.g
The cooperative parallel: A discussion about run-time schedulers for nested parallelism
Nested parallelism is a well-known parallelization strategy to exploit irregular parallelism in HPC applications. This strategy also fits in critical real-time embedded systems, composed of a set of concurrent functionalities. In this case, nested parallelism can be used to further exploit the parallelism of each functionality. However, current run-time implementations of nested parallelism can produce inefficiencies and load imbalance. Moreover, in critical real-time embedded systems, it may lead to incorrect executions due to, for instance, a work non-conserving scheduler. In both cases, the reason is that the teams of OpenMP threads are a black-box for the scheduler, i.e., the scheduler that assigns OpenMP threads and tasks to the set of available computing resources is agnostic to the internal execution of each team.
This paper proposes a new run-time scheduler that considers dynamic information of the OpenMP threads and tasks running within several concurrent teams, i.e., concurrent parallel regions. This information may include the existence of OpenMP threads waiting in a barrier and the priority of tasks ready to execute. By making the concurrent parallel regions to cooperate, the shared computing resources can be better controlled and a work conserving and priority driven scheduler can be guaranteed.Peer ReviewedPostprint (author's final draft
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