513 research outputs found
Reducing the Visual Signature of the M4A1 Rifle
The Maneuver Center of Excellence (MCoE) presented a directive to reduce the visual signature for small arms weapons by altering the color of the M4A1 rifle from its traditional black color. This research utilizes the Systems Decision Process (SDP) to develop and analyze alternatives to create a feasible and permanent solution to reduce the weapon’s visual signature. The research consisted of an extensive stakeholder and functional analysis to develop a value model and framework that provides a values-based recommendation. The model establishes an optimal color change process that accounts for the design and performance characteristics of the weapon system and the stakeholder’s values. The research also analyzes the potential integration of short wave infrared (SWIR) mitigation into the new color of the weapon. This analysis will establish a baseline methodology for weapon color change for all Army small arms weapons
Integration of FHIR to Facilitate Electronic Case Reporting: Results from a Pilot Study
Current approaches to gathering sexually transmitted infection (STI) case information for surveillance efforts are inefficient and lead to underreporting of disease burden. Electronic health information systems offer an opportunity to improve how STI case information can be gathered and reported to public health authorities. To test the feasibility of a standards-based application designed to automate STI case information collection and reporting, we conducted a pilot study where electronic laboratory messages triggered a FHIR-based application to query a patient’s electronic health record for details needed for an electronic case report (eCR). Out of 214 cases observed during a one week period, 181 (84.6%) could be successfully confirmed automatically using the FHIR-based application. Data quality and information representation challenges were identified that will require collaborative efforts to improve the structure of electronic clinical messages as well as the robustness of the FHIR application
Values of harmonic weak Maass forms on Hecke orbits
Let , where . For an even integer , let
be a meromorphic modular form of
weight on . For a positive integer , let be the th
Hecke operator and be a divisor of a modular curve with level . Both
subjects, the exponents of a modular form and the distribution of the
points in the support of , have been widely investigated.
When the level is one, Bruinier, Kohnen, and Ono obtained, in terms of
the values of -invariant function, identities between the exponents
of a modular form and the points in the support of . In this paper, we
extend this result to general in terms of values of harmonic weak
Maass forms of weight . By the distribution of Hecke points, this applies to
obtain an asymptotic behaviour of convolutions of sums of divisors of an
integer and sums of exponents of a modular form
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Plxnd1 Expression in Thymocytes Regulates Their Intrathymic Migration While That in Thymic Endothelium Impacts Medullary Topology
An important role for plexinD1 in thymic development is inferred from studies of germline Plxnd1 knockout (KO) mice where mislocalized CD69+ thymocytes as well as ectopic thymic subcapsular medullary structures were observed. Given embryonic lethality of the Plxnd1−/− genotype, fetal liver transplantation was employed in these prior analyses. Such embryonic hematopoietic reconstitution may have transferred Plxnd1 KO endothelial and/or epithelial stem cells in addition to Plxnd1 KO lymphoid progenitors, thereby contributing to that phenotype. Here we use Plxnd1flox/flox mice crossed to pLck-Cre, pKeratin14-Cre, or pTek-Cre transgenic animals to create cell-type specific conditional knockout (CKO) lines involving thymocytes (D1ThyCKO), thymic epithelium (D1EpCKO), and thymic endothelium (D1EnCKO), respectively. These CKOs allowed us to directly assess the role of plexinD1 in each lineage. Loss of plexinD1 expression on double positive (DP) thymocytes leads to their aberrant migration and cortical retention after TCR-mediated positive selection. In contrast, ectopic medulla formation is a consequence of loss of plexinD1 expression on endothelial cells, in turn linked to dysregulation of thymic angiogenesis. D1EpCKO thymi manifest neither abnormality. Collectively, our findings underscore the non-redundant roles for plexinD1 on thymocytes and endothelium, including the dynamic nature of medulla formation resulting from crosstalk between these thymic cellular components
Dual function filtration and catalytic breakdown of organic pollutants in wastewater using ozonation with titania and alumina membranes
Water recycling via treatment from industrial and/or municipal waste sources is one of the key strategies
for resolving water shortages worldwide. Polymer membranes are effective at improving the water quality
essential for recycling, but depend on regular cleaning and replacement. Pure ceramic membranes
can reduce the cleaning need and last significantly longer in the same applications while possessing the
possibility of operating in more aggressive environments not suitable for polymers. In the current work,
filtration using a tubular ceramic membrane (�-Al2O3 or TiO2) was combined with ozonation to remove
organic compounds present in a secondary effluent to enhance key quality features of the water (colour
and total organic carbon, TOC) for its potential reuse.
‘Bare’ commercial �-Al2O3 filters (pore size
∼0.58 �m) were tested as a microfiltration membrane and
compared with the more advanced catalytically active TiO2 layer that was formed by the sol–gel method.
The presence of anatase with a 4 nm pore size at the membrane surface was confirmed by X-ray diffraction
(XRD) and N2 adsorption. Filtration of the effluent over a 2 h period led to a reduction in flux to 45% and
60% of the initial values for the �-alumina and TiO2 membrane, respectively. However, a brief dose (2 min)
of ozone at the start of the run resulted in reductions to only 70% of the initial flux for both membranes. It
is likely that the oxide’s functional property facilitated the formation of hydroxyl (OH•) or other radicals
on the membrane surface from ozone decomposition which targeted the breakdown of organic foulants
thus inhibiting their deposition. Interestingly, the porous structure therefore acted in a synergistic, dual
function mode to physically separate the particulates while also catalytically breaking down organic
matter. The system also greatly improved the efficiency of membrane filtration for the reduction of
colour, A254 (organics absorption at the wavelength of 254 nm) and TOC. The best performance came
from combined ozonation (2 min ozonation time with an estimated applied ozone dose of 8 mg L−1)
with the TiO2 membrane, which was able to reduce colour by 88%, A254 by 75% and TOC by 43%. It is
clearly evident that a synergistic effect occurs with the process combination of ozonation and ceramic
membrane filtration demonstrating the practical benefit of combining ceramic membrane filtration with
conventional water ozonation
Protein logic: a statistical mechanical study of signal integration at the single-molecule level
Information processing and decision making is based upon logic operations,
which in cellular networks has been well characterized at the level of
transcription. In recent years however, both experimentalists and theorists
have begun to appreciate that cellular decision making can also be performed at
the level of a single protein, giving rise to the notion of protein logic. Here
we systematically explore protein logic using a well known statistical
mechanical model. As an example system, we focus on receptors which bind either
one or two ligands, and their associated dimers. Notably, we find that a single
heterodimer can realize any of the 16 possible logic gates, including the XOR
gate, by variation of biochemical parameters. We then introduce the novel idea
that a set of receptors with fixed parameters can encode functionally unique
logic gates simply by forming different dimeric combinations. An exhaustive
search reveals that the simplest set of receptors (two single-ligand receptors
and one double-ligand receptor) can realize several different groups of three
unique gates, a result for which the parametric analysis of single receptors
and dimers provides a clear interpretation. Both results underscore the
surprising functional freedom readily available to cells at the single-protein
level.Comment: 19 pages, 4 figures and 9 pages S
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Application of X-ray micro-computed tomography on high-speed cavitating diesel fuel flows
The flow inside a purpose built enlarged single-orifice nozzle replica is quantified using time-averaged X-ray micro-computed tomography (micro-CT) and high-speed shadowgraphy. Results have been obtained at Reynolds and cavitation numbers similar to those of real-size injectors. Good agreement for the cavitation extent inside the orifice is found between the micro-CT and the corresponding temporal mean 2D cavitation image, as captured by the high-speed camera. However, the internal 3D structure of the developing cavitation cloud reveals a hollow vapour cloud ring formed at the hole entrance and extending only at the lower part of the hole due to the asymmetric flow entry. Moreover, the cavitation volume fraction exhibits a significant gradient along the orifice volume. The cavitation number and the needle valve lift seem to be the most influential operating parameters, while the Reynolds number seems to have only small effect for the range of values tested. Overall, the study demonstrates that use of micro-CT can be a reliable tool for cavitation in nozzle orifices operating under nominal steady-state conditions
Genome-wide analysis of ivermectin response by Onchocerca volvulus reveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity
Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana-exposed to more than a decade of regular ivermectin treatment-have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread.Pooled next generation sequencing (Pool-seq) was used to characterise genetic diversity within and between 108 adult female worms differing in ivermectin treatment history and response. Genome-wide analyses revealed genetic variation that significantly differentiated good responder (GR) and sub-optimal responder (SOR) parasites. These variants were not randomly distributed but clustered in ~31 quantitative trait loci (QTLs), with little overlap in putative QTL position and gene content between the two countries. Published candidate ivermectin SOR genes were largely absent in these regions; QTLs differentiating GR and SOR worms were enriched for genes in molecular pathways associated with neurotransmission, development, and stress responses. Finally, single worm genotyping demonstrated that geographic isolation and genetic change over time (in the presence of drug exposure) had a significantly greater role in shaping genetic diversity than the evolution of SOR.This study is one of the first genome-wide association analyses in a parasitic nematode, and provides insight into the genomics of ivermectin response and population structure of O. volvulus. We argue that ivermectin response is a polygenically-determined quantitative trait (QT) whereby identical or related molecular pathways but not necessarily individual genes are likely to determine the extent of ivermectin response in different parasite populations. Furthermore, we propose that genetic drift rather than genetic selection of SOR is the underlying driver of population differentiation, which has significant implications for the emergence and potential spread of SOR within and between these parasite populations
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