54 research outputs found
“The Street Was One Place We Could Not Go”: The American Army and Urban Combat in World War II Europe
Much has been written about the nature of the United States Army in World War
II and the topic of military effectiveness. This dissertation examines how the United
States responded to a combat environment, specifically, fighting in built-up areas, that it
had not planned to fight within before World War II. By following three infantry
divisions, the 1st, 3rd, and 5th Infantry Divisions through their combat in World War II,
this dissertation investigates how the Army of the United States fought within the urban
setting to see whether the American Army improved and became more effective as the
war continued.
It argues that the 1st, 3rd, and 5th Infantry Divisions learned and became more
proficient at urban combat over time. This dissertation asserts that as these divisions
embraced combined-arms operations in general, that is, mastered the coordination of
infantry weapons, armor, and artillery into battle, so they applied those lessons to the
urban environment. Whereas the American military had neither doctrine nor tradition of
urban combat before World War II, combat units learned to develop methods of fighting
within towns and cities. Further, the United States Army processed and incorporated
these battlefield lessons into military doctrine at a slower rate. The infantry divisions’
combat experience had a greater impact on army doctrine than the doctrine had on the
divisions’ warfighting practices
“The Street Was One Place We Could Not Go”: The American Army and Urban Combat in World War II Europe
Much has been written about the nature of the United States Army in World War
II and the topic of military effectiveness. This dissertation examines how the United
States responded to a combat environment, specifically, fighting in built-up areas, that it
had not planned to fight within before World War II. By following three infantry
divisions, the 1st, 3rd, and 5th Infantry Divisions through their combat in World War II,
this dissertation investigates how the Army of the United States fought within the urban
setting to see whether the American Army improved and became more effective as the
war continued.
It argues that the 1st, 3rd, and 5th Infantry Divisions learned and became more
proficient at urban combat over time. This dissertation asserts that as these divisions
embraced combined-arms operations in general, that is, mastered the coordination of
infantry weapons, armor, and artillery into battle, so they applied those lessons to the
urban environment. Whereas the American military had neither doctrine nor tradition of
urban combat before World War II, combat units learned to develop methods of fighting
within towns and cities. Further, the United States Army processed and incorporated
these battlefield lessons into military doctrine at a slower rate. The infantry divisions’
combat experience had a greater impact on army doctrine than the doctrine had on the
divisions’ warfighting practices
Planar Silicon Metamaterial Lenslet Arrays for Millimeter-wavelength Imaging
Large imaging arrays of detectors at millimeter and submillimeter wavelengths
have applications that include measurements of the faint polarization signal in
the Cosmic Microwave Background (CMB), and submillimeter astrophysics. We are
developing planar lenslet arrays for millimeter-wavelength imaging using
metamaterials microlithically fabricated using silicon wafers. This
metamaterial technology has many potential advantages compared to conventional
hemispherical lenslet arrays, including high precision and homogeneity, planar
integrated anti-reflection layers, and a coefficient of thermal expansion
matched to the silicon detector wafer. Here we describe the design process for
a gradient-index (GRIN) metamaterial lenslet using metal-mesh patterned on
silicon and a combination of metal-mesh and etched-hole metamaterial
anti-reflection layers. We optimize the design using a bulk-material model to
rapidly simulate and iterate on the lenslet design. We fabricated prototype
GRIN metamaterial lenslet array and mounted it on a Polarbear/Simons Array
90/150~GHz band transition edge sensor (TES) bolometer detector array with
sinuous planar antennas. Beam measurements of a prototype lenslet array agree
reasonably well with the model simulations. We plan to further optimize the
design and combine it with a broadband anti-reflection coating to achieve
operation over 70--350~GHz bandwidth.Comment: Presented at SPIE Millimeter, Submillimeter, and Far-Infrared
Detectors and Instrumentation for Astronomy X, December 13-18, 202
Mechanical design and development of TES bolometer detector arrays for the Advanced ACTPol experiment
The next generation Advanced ACTPol (AdvACT) experiment is currently underway
and will consist of four Transition Edge Sensor (TES) bolometer arrays, with
three operating together, totaling ~5800 detectors on the sky. Building on
experience gained with the ACTPol detector arrays, AdvACT will utilize various
new technologies, including 150mm detector wafers equipped with multichroic
pixels, allowing for a more densely packed focal plane. Each set of detectors
includes a feedhorn array of stacked silicon wafers which form a spline profile
leading to each pixel. This is then followed by a waveguide interface plate,
detector wafer, back short cavity plate, and backshort cap. Each array is
housed in a custom designed structure manufactured from high purity copper and
then gold plated. In addition to the detector array assembly, the array package
also encloses cryogenic readout electronics. We present the full mechanical
design of the AdvACT high frequency (HF) detector array package along with a
detailed look at the detector array stack assemblies. This experiment will also
make use of extensive hardware and software previously developed for ACT, which
will be modified to incorporate the new AdvACT instruments. Therefore, we
discuss the integration of all AdvACT arrays with pre-existing ACTPol
infrastructure.Comment: 9 pages, 5 figures, SPIE Astronomical Telescopes and Instrumentation
conference proceeding
The Atacama Cosmology Telescope: Two-Season ACTPol Lensing Power Spectrum
We report a measurement of the power spectrum of cosmic microwave background
(CMB) lensing from two seasons of Atacama Cosmology Telescope Polarimeter
(ACTPol) CMB data. The CMB lensing power spectrum is extracted from both
temperature and polarization data using quadratic estimators. We obtain results
that are consistent with the expectation from the best-fit Planck LCDM model
over a range of multipoles L=80-2100, with an amplitude of lensing A_lens =
1.06 +/- 0.15 (stat.) +/- 0.06 (sys.) relative to Planck. Our measurement of
the CMB lensing power spectrum gives sigma_8 Omega_m^0.25 = 0.643 +/- 0.054;
including baryon acoustic oscillation scale data, we constrain the amplitude of
density fluctuations to be sigma_8 = 0.831 +/- 0.053. We also update
constraints on the neutrino mass sum. We verify our lensing measurement with a
number of null tests and systematic checks, finding no evidence of significant
systematic errors. This measurement relies on a small fraction of the ACTPol
data already taken; more precise lensing results can therefore be expected from
the full ACTPol dataset.Comment: 17 pages, 11 figures, to be submitted to Physical Review
The Atacama Cosmology Telescope: Two-Season ACTPol Spectra and Parameters
We present the temperature and polarization angular power spectra measured by
the Atacama Cosmology Telescope Polarimeter (ACTPol). We analyze night-time
data collected during 2013-14 using two detector arrays at 149 GHz, from 548
deg of sky on the celestial equator. We use these spectra, and the spectra
measured with the MBAC camera on ACT from 2008-10, in combination with Planck
and WMAP data to estimate cosmological parameters from the temperature,
polarization, and temperature-polarization cross-correlations. We find the new
ACTPol data to be consistent with the LCDM model. The ACTPol
temperature-polarization cross-spectrum now provides stronger constraints on
multiple parameters than the ACTPol temperature spectrum, including the baryon
density, the acoustic peak angular scale, and the derived Hubble constant.
Adding the new data to planck temperature data tightens the limits on damping
tail parameters, for example reducing the joint uncertainty on the number of
neutrino species and the primordial helium fraction by 20%.Comment: 23 pages, 25 figure
CORE: A Phylogenetically-Curated 16S rDNA Database of the Core Oral Microbiome
Comparing bacterial 16S rDNA sequences to GenBank and other large public databases via BLAST often provides results of little use for identification and taxonomic assignment of the organisms of interest. The human microbiome, and in particular the oral microbiome, includes many taxa, and accurate identification of sequence data is essential for studies of these communities. For this purpose, a phylogenetically curated 16S rDNA database of the core oral microbiome, CORE, was developed. The goal was to include a comprehensive and minimally redundant representation of the bacteria that regularly reside in the human oral cavity with computationally robust classification at the level of species and genus. Clades of cultivated and uncultivated taxa were formed based on sequence analyses using multiple criteria, including maximum-likelihood-based topology and bootstrap support, genetic distance, and previous naming. A number of classification inconsistencies for previously named species, especially at the level of genus, were resolved. The performance of the CORE database for identifying clinical sequences was compared to that of three publicly available databases, GenBank nr/nt, RDP and HOMD, using a set of sequencing reads that had not been used in creation of the database. CORE offered improved performance compared to other public databases for identification of human oral bacterial 16S sequences by a number of criteria. In addition, the CORE database and phylogenetic tree provide a framework for measures of community divergence, and the focused size of the database offers advantages of efficiency for BLAST searching of large datasets. The CORE database is available as a searchable interface and for download at http://microbiome.osu.edu
Chronic Activation of γ2 AMPK Induces Obesity and Reduces β Cell Function.
Despite significant advances in our understanding of the biology determining systemic energy homeostasis, the treatment of obesity remains a medical challenge. Activation of AMP-activated protein kinase (AMPK) has been proposed as an attractive strategy for the treatment of obesity and its complications. AMPK is a conserved, ubiquitously expressed, heterotrimeric serine/threonine kinase whose short-term activation has multiple beneficial metabolic effects. Whether these translate into long-term benefits for obesity and its complications is unknown. Here, we observe that mice with chronic AMPK activation, resulting from mutation of the AMPK γ2 subunit, exhibit ghrelin signaling-dependent hyperphagia, obesity, and impaired pancreatic islet insulin secretion. Humans bearing the homologous mutation manifest a congruent phenotype. Our studies highlight that long-term AMPK activation throughout all tissues can have adverse metabolic consequences, with implications for pharmacological strategies seeking to chronically activate AMPK systemically to treat metabolic disease
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