1,220 research outputs found
Hal Koch, Grundtvig and the rescue of the Danish Jews: A case study in the democratic mobilisation for non-violent resistance
Hal Koch, Grundtvig and the rescue of the Danish Jews: A case study in the democratic mobilisation for non-violent resistance[Hal Koch, Grundtvig og redningen af de danske jøder: Et case study i demokratisk mobilisering af ikke-voldelig modstand]Af Steven BorishDet danske folks mobilisering af en ikke-voldelig “kulturmodstand” mod den nazistiske besættelse (1940-1945) kulminerede i en redningsaktion, der fandt sted i efteråret 1943, hvor de lykkedes at fa bragt 7.220 af de omkring 7.800 jøder, som på det tidspunkt befandt sig i Danmark, i sikkerhed i det neutrale Sverige. I de aktiviteter, der blev iværksat efter invasionen den 9. april 1940 - specielt i løbet af sommeren 1940 og de følgende år - spillede den karismatiske leder Hal Koch, og gennem ham hans mindeværdige forgænger i det nittende århundrede, N. F. S. Grundtvig, en central rolle. Disse bemærkelsesværdige hændelser i Danmark bør indarbejdes ikke blot i dansk historieskrivning, men også i den verdensomspændende historieskrivning om demokratiske, nationale mål nået med ikke-voldelige midler
S. A. J. Bradley, N. F. S. Grundtvig: A life recalled
S.A.J. Bradley, N.F.S. Grundtvig: Et liv minde
Implementation and goals of quantum optics experiments in undergraduate instructional labs
As quantum information science and technology (QIST) is becoming more
prevalent and occurring not only in research labs but also in industry, many
educators are considering how best to incorporate learning about quantum
mechanics into various levels of education. Although much of the focus has been
on quantum concepts in non-lab courses, current work in QIST has a substantial
experimental component. Many instructors of undergraduate lab courses want to
provide their students the opportunity to work with quantum experiments. One
common way this is done is through a sequence of quantum optics experiments
often referred to as the ``single-photon experiments.'' These experiments
demonstrate fundamental quantum phenomena with equipment common to research
labs; however, they are resource intensive and cannot be afforded by all
institutions. It is therefore imperative to know what unique affordances these
experiments provide to students. As a starting point, we surveyed and
interviewed instructors who use the single-photon experiments in undergraduate
courses, asking how and why they use the experiments. We describe the most
commonly used experiments in both quantum and beyond-first-year lab courses,
the prevalence of actions the students perform, and the learning goals, ranging
from conceptual knowledge to lab skills to student affect. Finally, we present
some strategies from these data demonstrating how instructors have addressed
the common challenges of preparing students to work with conceptually and
technically complex experiments and balancing the practice of technical skills
with the completion of the experiments.Comment: 18 pages, 4 figures, minor edit
Th2 cytokines and asthma — Interleukin-4: its role in the pathogenesis of asthma, and targeting it for asthma treatment with interleukin-4 receptor antagonists
Interleukin-4 (IL-4) mediates important pro-inflammatory functions in asthma including induction of the IgE isotype switch, expression of vascular cell adhesion molecule-1 (VCAM-1), promotion of eosinophil transmigration across endothelium, mucus secretion, and differentiation of T helper type 2 lymphocytes leading to cytokine release. Asthma is a complex genetic disorder that has been linked to polymorphisms in the IL-4 gene promoter and proteins involved in IL-4 signaling. Soluble recombinant IL-4 receptor lacks transmembrane and cytoplasmic activating domains and can therefore sequester IL-4 without mediating cellular activation. We report the results of initial clinical trials, which demonstrate clinical efficacy of this naturally occurring IL-4 antagonist as a therapeutic agent in asthma
Seeing quantum effects in experiments
Quantum mechanics is a field often considered very mathematical, abstract,
and unintuitive. One way some instructors are hoping to help familiarize their
students with these complex topics is to have the students see quantum effects
in experiments in undergraduate instructional labs. Here, we present results
from an interview study about what it means to both instructors and students to
see quantum effects in experiments. We focus on a popular set of quantum optics
experiments, and find that students believe they are observing quantum effects
and achieving related learning goals by working with these experiments.
Although it is not possible to see the quantum phenomena directly with their
eyes, students point out different aspects of the experiments that contribute
to them observing quantum effects. This often includes seeing the experimental
results, sometimes in conjunction with interacting with or understanding part
of the experiment. There is additional variation across student achievement of
the various related learning goals, ranging from many of the students being
excited about these experiments and making a connection between the
mathematical theory and the experiments to only some of the students seeing a
connection between these experiments and quantum technologies. This work can
help instructors consider the importance and framing of quantum experiments and
raises questions about when and how in the curriculum quantum experiments can
be best utilized and how to make related learning goals available to all
students.Comment: 26 pages, 0 figure
Update on Allergy Immunotherapy
This article summarizes and provides commentary regarding guidelines on the administration of immunotherapy (IT) for allergic airway disease. Recent investigations have provided important insights into the immunologic mechanism of IT and the prominent role of interleukin-10-producing regulatory T lymphocytes. The most important aspect of successful IT is the administration of an appropriate dose of an extract containing a sufficient concentration of the relevant allergen. This is largely possible now only with standardized extracts. When the major allergen content of successful IT extracts was quantified, efficacy was demonstrated across a surprisingly narrow concentration range (approximately 5-24 ÎĽg per injection), irrespective of the extract. This presumably reflects the concentration of an antigen that drives an immune response toward tolerance. It may be predicted that as major allergen content is quantified in currently nonstandardized extracts, effective IT will also be achieved by administering a dose in this range, in contrast to current practices involving fairly arbitrary dosing decisions. With the availability of nonsedating antihistamines, intranasal corticosteroids, and the leukotriene modifiers, inadequate pharmacologic response or intolerable side effects are less commonly the major indications for starting IT for allergic rhinitis (AR). However, with the recognition that a relatively short course (3-5 years) of IT can provide long-term immunomodulation and clinical benefit, a desire to avoid long-term pharmacotherapy and the associated high costs may be the primary indication for IT in AR cases. While evidence overwhelmingly supports the beneficial influences of IT in asthma cases, the positioning of IT for this disorder is not established. The observed prevention of asthma in children who have AR is intriguing, but further studies are required to assess the extent to which the prevalence and severity of chronic asthma will be reduced when these children reach adulthood. Similarly, safety issues overwhelmingly suggest that uncontrolled asthma is the greatest risk factor for mortality associated with IT and that IT therefore may be contraindicated for most patients who have inadequate pharmacologic responses or are unable to tolerate useful pharmacologic agents. Paradoxically, these are the patients for whom a response to IT may be most desirable
Near infrared spectroscopy of the type IIn SN 2010jl: evidence for high velocity ejecta
The Type IIn supernova SN 2010jl was relatively nearby and luminous, allowing
detailed studies of the near-infrared (NIR) emission. We present 1 - 2.4 micron
spectroscopy over the age range of 36 - 565 days from the earliest detection of
the supernova. On day 36, the H lines show an unresolved narrow emission
component along with a symmetric broad component that can be modeled as the
result of electron scattering by a thermal distribution of electrons. Over the
next hundreds of days, the broad components of the H lines shift to the blue by
700 km/s, as is also observed in optical lines. The narrow lines do not show a
shift, indicating they originate in a different region. He I 1.0830 and 2.0587
micron lines both show an asymmetric broad emission component, with a shoulder
on the blue side that varies in prominence and velocity from -5500 km/s on day
108 to -4000 km/s on day 219. This component may be associated with the higher
velocity flow indicated by X-ray observations of the supernova. The absence of
the feature in the H lines suggests that this is from a He rich ejecta flow.
The He I 1.0830 micron feature has a narrow P Cygni line, with absorption
extending to ~100 km/s and strengthening over the first 200 days, and an
emission component which weakens with time. At day 403, the continuum emission
becomes dominated by a blackbody spectrum with a temperature of ~1900 K,
suggestive of dust emission.Comment: 17 pages, 18 figure
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