1,285 research outputs found
Technology Development for the Caltech Submillimeter Observatory Balanced Receivers
The Caltech Submillimeter Observatory (CSO) is located on top of Mauna Kea,
Hawaii, at an altitude of 4.2 km. The existing suite of facility heterodyne
receivers covering the submillimeter band is rapidly aging and in need of
replacement. To facilitate deep integrations and automated spectral line
surveys, a family of remote programmable, synthesized, dual-frequency balanced
receivers covering the astronomical important 180 - 720 GHz atmospheric windows
is in an advanced stage of development. Installation of the first set of
receivers is expected in the spring of 2012.
Dual-frequency observation will be an important mode of operation offered by
the new facility instrumentation. Two band observations are accomplished by
separating the H and V polarizations of the incoming signal and routing them
via folded optics to the appropriate polarization sensitive balanced mixer.
Scientifically this observation mode facilitates pointing for the higher
receiver band under mediocre weather conditions and a doubling of scientific
throughput (2 x 4 GHz) under good weather conditions.Comment: 12 pages, 17 figures; IEEE Terahertz Science & Technology, January
2012, Volume 2, Issue
Hole-burning experiments within solvable glassy models
We reproduce the results of non-resonant spectral hole-burning experiments
with fully-connected (equivalently infinite-dimensional) glassy models that are
generalizations of the mode-coupling approach to nonequilibrium situations. We
show that an ac-field modifies the integrated linear response and the
correlation function in a way that depends on the amplitude and frequency of
the pumping field. We study the effect of the waiting and recovery-times and
the number of oscillations applied. This calculation will help descriminating
which results can and which cannot be attributed to dynamic heterogeneities in
real systems.Comment: 4 pages, 8 figures, RevTe
Maximizing the Benefit-Cost Ratio of Anthracyclines in Metastatic Breast Cancer: Case Report of a Patient with a Complete Response to High-Dose Doxorubicin
Despite the clinical efficacy of anthracycline agents such as doxorubicin, dose-limiting cardiac toxicities significantly limit their long-term use. Here, we present the case of a 33-year-old female patient with extensive metastatic ER+/PR+/HER2ā mucinous adenocarcinoma of the breast, who was started on doxorubicin/cyclophosphamide therapy after progressing on paclitaxel and ovarian suppressor goserelin with aromatase inhibitor exemestane. The patient was comanaged by cardiology, who carefully monitored measures of cardiac function, including EKGs, serial echocardiograms, and profiling of lipids, troponin, and pro-BNP every 2 months. The patient was treated with the cardioprotective agent dexrazoxane, and changes in cardiac markers [e.g. decreases in ejection fraction (EF)] were immediately addressed by therapeutic intervention with the ACE inhibitor lisinopril and beta-blocker metoprolol. The patient had a complete response to doxorubicin therapy, with a cumulative dose of 1,350 mg/m2, which is significantly above the recommended limits, and to our knowledge, the highest dose reported in literature. Two and a half years after the last doxorubicin cycle, the patient is asymptomatic with no cardiotoxicity and an excellent quality of life. This case highlights the importance of careful monitoring and management of doxorubicin-mediated cardiotoxicity, and that higher cumulative doses of anthracyclines can be considered in patients with ongoing clinical benefit
RDF Querying
Reactive Web systems, Web services, and Web-based publish/
subscribe systems communicate events as XML messages, and in
many cases require composite event detection: it is not sufficient to react
to single event messages, but events have to be considered in relation to
other events that are received over time.
Emphasizing language design and formal semantics, we describe the
rule-based query language XChangeEQ for detecting composite events.
XChangeEQ is designed to completely cover and integrate the four complementary
querying dimensions: event data, event composition, temporal
relationships, and event accumulation. Semantics are provided as
model and fixpoint theories; while this is an established approach for rule
languages, it has not been applied for event queries before
The Caenorhabditis elegans vulva: A post-embryonic gene regulatory network controlling organogenesis
The Caenorhabditis elegans vulva is an elegant model for dissecting a gene regulatory network (GRN) that directs postembryonic organogenesis. The mature vulva comprises seven cell types (vulA, vulB1, vulB2, vulC, vulD, vulE, and vulF), each with its own unique pattern of spatial and temporal gene expression. The mechanisms that specify these cell types in a precise spatial pattern are not well understood. Using reverse genetic screens, we identified novel components of the vulval GRN, including nhr-113 in vulA. Several transcription factors (lin-11, lin-29, cog-1, egl-38, and nhr-67) interact with each other and act in concert to regulate target gene expression in the diverse vulval cell types. For example, egl-38 (Pax2/5/8) stabilizes the vulF fate by positively regulating vulF characteristics and by inhibiting characteristics associated with the neighboring vulE cells. nhr-67 and egl-38 regulate cog-1, helping restrict its expression to vulE. Computational approaches have been successfully used to identify functional cis-regulatory motifs in the zmp-1 (zinc metalloproteinase) promoter. These results provide an overview of the regulatory network architecture for each vulval cell type
The Antarctic Submillimeter Telescope and Remote Observatory (AST/RO)
AST/RO, a 1.7 m diameter telescope for astronomy and aeronomy studies at
wavelengths between 200 and 2000 microns, was installed at the South Pole
during the 1994-1995 Austral summer. The telescope operates continuously
through the Austral winter, and is being used primarily for spectroscopic
studies of neutral atomic carbon and carbon monoxide in the interstellar medium
of the Milky Way and the Magellanic Clouds. The South Pole environment is
unique among observatory sites for unusually low wind speeds, low absolute
humidity, and the consistent clarity of the submillimeter sky. Four heterodyne
receivers, an array receiver, three acousto-optical spectrometers, and an array
spectrometer are installed. A Fabry-Perot spectrometer using a bolometric array
and a Terahertz receiver are in development. Telescope pointing, focus, and
calibration methods as well as the unique working environment and logistical
requirements of the South Pole are described.Comment: 57 pages, 15 figures. Submitted to PAS
Stretched exponential relaxation in the mode-coupling theory for the Kardar-Parisi-Zhang equation
We study the mode-coupling theory for the Kardar-Parisi-Zhang equation in the
strong-coupling regime, focusing on the long time properties. By a saddle point
analysis of the mode-coupling equations, we derive exact results for the
correlation function in the long time limit - a limit which is hard to study
using simulations. The correlation function at wavevector k in dimension d is
found to behave asymptotically at time t as C(k,t)\simeq 1/k^{d+4-2z}
(Btk^z)^{\gamma/z} e^{-(Btk^z)^{1/z}}, with \gamma=(d-1)/2, A a determined
constant and B a scale factor.Comment: RevTex, 4 pages, 1 figur
Solidity of Viscous Liquids
Recent NMR experiments on supercooled toluene and glycerol by Hinze and
Bohmer show that small rotation angles dominate with only few large molecular
rotations. These results are here interpreted by assuming that viscous liquids
are solid-like on short length scales. A characteristic length, the "solidity
length", separates solid-like behavior from liquid-like behavior.Comment: Plain RevTex file, no figure
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