6 research outputs found
A CubeSat for Calibrating Ground-Based and Sub-Orbital Millimeter-Wave Polarimeters (CalSat)
We describe a low-cost, open-access, CubeSat-based calibration instrument
that is designed to support ground-based and sub-orbital experiments searching
for various polarization signals in the cosmic microwave background (CMB). All
modern CMB polarization experiments require a robust calibration program that
will allow the effects of instrument-induced signals to be mitigated during
data analysis. A bright, compact, and linearly polarized astrophysical source
with polarization properties known to adequate precision does not exist.
Therefore, we designed a space-based millimeter-wave calibration instrument,
called CalSat, to serve as an open-access calibrator, and this paper describes
the results of our design study. The calibration source on board CalSat is
composed of five "tones" with one each at 47.1, 80.0, 140, 249 and 309 GHz. The
five tones we chose are well matched to (i) the observation windows in the
atmospheric transmittance spectra, (ii) the spectral bands commonly used in
polarimeters by the CMB community, and (iii) The Amateur Satellite Service
bands in the Table of Frequency Allocations used by the Federal Communications
Commission. CalSat would be placed in a polar orbit allowing visibility from
observatories in the Northern Hemisphere, such as Mauna Kea in Hawaii and
Summit Station in Greenland, and the Southern Hemisphere, such as the Atacama
Desert in Chile and the South Pole. CalSat also would be observable by
balloon-borne instruments launched from a range of locations around the world.
This global visibility makes CalSat the only source that can be observed by all
terrestrial and sub-orbital observatories, thereby providing a universal
standard that permits comparison between experiments using appreciably
different measurement approaches
ライティング コミュニケーション オ トオシタ キョウシ ガクセイ セイト カン ノ シンライ カンケイ オ コウチク スル ホウホウ : クラス ジャーナル オ モチイタ ダイガク チュウガッコウ デノ ジレイ ショウカイ
教師にとって学生全員とコミュニケーションをとることは信頼関係を築くためや、クラスを運営していく上で必要なことですが、実際の教育現場では人数または時間の関係から十分なコミュニケーションをとる事は難しいと思います。本文が紹介するクラス・ジャーナルは教師ー学生・生徒間でコメントのやり取り等をするための用紙であり、私たちは、教師と学生・生徒がダイアローグを通してコミュニケーションをとることで、学生一人一人との関係性(relatedness)を高めることができると考えています。 また、クラス・ジャーナルを利用することによって、学生自身が学習状況を振り返ることができるほか、管理することが可能になります。ここでは、大学と中学校でのクラス・ジャーナル活用術とそれぞれで現れた効果を記載しています
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
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Essential Role of Human T Cell Leukemia Virus Type 1 orf-I in Lethal Proliferation of CD4+ Cells in Humanized Mice
Human T cell leukemia virus type 1 (HTLV-1) is the ethological agent of adult T cell leukemia/lymphoma (ATLL) and a number of lymphocyte-mediated inflammatory conditions, including HTLV-1-associated myelopathy/tropical spastic paraparesis. HTLV-1 orf-I encodes two proteins, p8 and p12, whose functions in humans are to counteract innate and adaptive responses and to support viral transmission. However, the in vivo requirements for orf-I expression vary in different animal models. In macaques, the ablation of orf-I expression by mutation of its ATG initiation codon abolishes the infectivity of the molecular clone HTLV-1p12KO. In rabbits, HTLV-1p12KO is infective and persists efficiently. We used humanized mouse models to assess the infectivity of both wild-type HTLV-1 (HTLV-1WT) and HTLV-1p12KO. We found that NOD/SCID/γC-/- c-kit+ mice engrafted with human tissues 1 day after birth (designated NSG-1d mice) were highly susceptible to infection by HTLV-1WT, with a syndrome characterized by the rapid polyclonal proliferation and infiltration of CD4+ CD25+ T cells into vital organs, weight loss, and death. HTLV-1 clonality studies revealed the presence of multiple clones of low abundance, confirming the polyclonal expansion of HTLV-1-infected cells in vivo. HTLV-1p12KO infection in a bone marrow-liver-thymus (BLT) mouse model prone to graft-versus-host disease occurred only following reversion of the orf-I initiation codon mutation within weeks after exposure and was associated with high levels of HTLV-1 DNA in blood and the expansion of CD4+ CD25+ T cells. Thus, the incomplete reconstitution of the human immune system in BLT mice may provide a window of opportunity for HTLV-1 replication and the selection of viral variants with greater fitness.IMPORTANCE Humanized mice constitute a useful model for studying the HTLV-1-associated polyclonal proliferation of CD4+ T cells and viral integration sites in the human genome. The rapid death of infected animals, however, appears to preclude the clonal selection typically observed in human ATLL, which normally develops in 2 to 5 of individuals infected with HTLV-1. Nevertheless, the expansion of multiple clones of low abundance in these humanized mice mirrors the early phase of HTLV-1 infection in humans, providing a useful model to investigate approaches to inhibit virus-induced CD4+ T cell proliferation