52 research outputs found
Het virus der betrokkenheid
Het Internationaal Instituut voor Sociale Geschiedenis (IISG) is een van de meest vooraanstaande onderzoeksinstituten ter wereld op het terrein van de sociale geschiedenis, zowel in het wetenschappelijk onderzoek als in het verzamelen en beheren van een unieke internationale collectie archieven. Dit boek onderzoekt de geschiedenis van het Instituut van 1935 tot 1989. Centraal staat de ontwikkeling van het Instituut in de richting van een steeds sterkere professionalisering. Een ontwikkeling in wisselwerking met een driehoek van externe invloeden: de politieke en maatschappelijke context; de ontwikkeling van sociale geschiedenis als academische discipline; en het institutionele en bestuurlijke kader. Het is het verhaal van betrokken historici en activisten, die het erfgoed van en uit de arbeidersbeweging en andere emancipatiebewegingen wilden veiligstellen en voor onderzoek beschikbaar maken. Het boek neemt de lezer mee naar spectaculaire reddingsacties van archieven en bibliotheken die bedreigd waren door de opkomst van Hitler, de ineenstorting van het IISG tijdens de bezetting, en de wonderbaarlijke terugkeer van de meeste collecties na de oorlog. Tijdens de wederopbouw volgde een zoektocht naar een plaats in de academische infrastructuur. Intern raakte het Instituut ontregeld tijdens de roerige jaren zestig en zeventig. In de jaren tachtig vond het IISG de weg naar verdere professionalisering zonder zijn oorspronkelijke bestaansrecht en drijfveren uit het oog te verliezen
Vigorous star formation hidden by dust in a galaxy at
Near-infrared surveys have revealed a substantial population of enigmatic
faint galaxies with extremely red optical-to-near-infrared colours and with a
sky surface density comparable to that of faint quasars. There are two
scenarios for these extreme colours: (i) these distant galaxies have formed
virtually all their stars at very high redshifts and, due to the absence of
recently formed stars, the colours are extremely red and (ii) these distant
galaxies contain large amounts of dust, severely reddening the rest-frame
UV--optical spectrum. HR10 () is considered the archetype of the
extremely red galaxies. Here we report the detection of the continuum emission
from HR10 at 850m and at 1250m, demonstrating that HR10 is a very
dusty galaxy undergoing a major episode of star formation. Our result provides
a clear example of a high-redshift galaxy where the star formation rate
inferred from the ultraviolet luminosity would be underestimated by a factor up
to 1000, and shows that great caution should be used to infer the global star
formation history of the Universe from optical observations only.Comment: 12 pages, 1 figure, Nature, in press (30 April 1998
Strategy-focused writing instruction: just observing and reflecting on a model benefits 6th grade students
Three groups of typically-developing 6th grade students (total N = 62) each completed strategy-focused writing training. Using a combined lagged-group and cross-panel design we assessed the effectiveness of a sequence of four different instructional components: observation of and group reflection on a mastery model, direct (declarative) instruction, peer feedback and solo practice. Cumulative effects on written product and writing process were assessed at baseline and after each component. Findings supported the effectiveness of strategy-focused intervention: All three groups showed gains, relative to controls, in the quality of their written products assessed by both holistic and text-analytic measures, and a more structured and goal-focused planning processes. These effects were associated almost exclusively with the modelling and reflection component. Improved performance was sustained through other instructional components but there was no strong evidence that they provided additional benefit. This finding was replicated in all three groups, and across two different text-types
Magnetic Fields, Relativistic Particles, and Shock Waves in Cluster Outskirts
It is only now, with low-frequency radio telescopes, long exposures with
high-resolution X-ray satellites and gamma-ray telescopes, that we are
beginning to learn about the physics in the periphery of galaxy clusters. In
the coming years, Sunyaev-Zeldovich telescopes are going to deliver further
great insights into the plasma physics of these special regions in the
Universe. The last years have already shown tremendous progress with detections
of shocks, estimates of magnetic field strengths and constraints on the
particle acceleration efficiency. X-ray observations have revealed shock fronts
in cluster outskirts which have allowed inferences about the microphysical
structure of shocks fronts in such extreme environments. The best indications
for magnetic fields and relativistic particles in cluster outskirts come from
observations of so-called radio relics, which are megaparsec-sized regions of
radio emission from the edges of galaxy clusters. As these are difficult to
detect due to their low surface brightness, only few of these objects are
known. But they have provided unprecedented evidence for the acceleration of
relativistic particles at shock fronts and the existence of muG strength fields
as far out as the virial radius of clusters. In this review we summarise the
observational and theoretical state of our knowledge of magnetic fields,
relativistic particles and shocks in cluster outskirts.Comment: 34 pages, to be published in Space Science Review
Dust and star formation in distant radio galaxies
We present the results of an observing program with the SCUBA bolometer array
to measure the submillimetre (submm) dust continuum emission of 24 distant (z >
1) radio galaxies. We detected submm emission in 12 galaxies with S/N > 3,
including 9 detections at z > 3. When added to previous published results these
data almost triple the number of radio galaxies with z > 3 detected in the
submm and yield a sample of 69 observed radio galaxies over the redshift range
z = 1-5. We find that the range in rest-frame far-infrared luminosities is
about a factor of 10. We have investigated the origin of this dispersion,
correlating the luminosities with radio source power, size, spectral index,
K-band magnitude and Lya luminosity. No strong correlations are apparent in the
combined data set. We confirm and strengthen the result from previous submm
observations of radio galaxies that the detection rate is a strong function of
redshift. We compare the redshift dependence of the submm properties of radio
galaxies with those of quasars and find that for both classes of objects the
observed submm flux density increases with redshift to z ~ 4, beyond which, for
the galaxies, we find tentative evidence for a decline. We find evidence for an
anti-correlation between submm luminosity and UV polarisation fraction, for a
subsample of 13 radio galaxies, indicating that starbursts are the dominant
source of heating for dust in radio galaxies.Comment: 15 pages, 11 PS figures, accepted for publication in MNRAS; corrected
sample analysis, minor changes in tables and figure
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 nonâcritically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (nâ=â257), ARB (nâ=â248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; nâ=â10), or no RAS inhibitor (control; nâ=â264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ supportâfree days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ supportâfree days among critically ill patients was 10 (â1 to 16) in the ACE inhibitor group (nâ=â231), 8 (â1 to 17) in the ARB group (nâ=â217), and 12 (0 to 17) in the control group (nâ=â231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ supportâfree days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
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