1,519 research outputs found
Small Unmanned Aircraft (sUAS)-Deployed Thermal Infrared (TIR) Imaging for Environmental Surveys with Implications in Submarine Groundwater Discharge (SGD): Methods, Challenges, and Novel Opportunities
Submarine Groundwater Discharge (SGD) represents a significant mode of chemical transport to water bodies, making it an important flux to understand. Small Unmanned Aircraft Systems-deployed thermal infrared sensors (sUAS-TIR) provide a financially and logistically inexpensive means of identifying SGD source zones and quantifying SGD thermal infrared (TIR) plume areas over regional scales at high spatial resolutions. sUAS-TIR additionally offers the unique capability of high temporal resolution measurements of SGD. As a developing science application, the use of sUAS-TIR to image SGD requires substantial background knowledge. We present a proposed methodological construct for implementing a sUAS-TIR program for SGD-TIR data gathering, with applications extending to other research fields that can benefit from airborne TIR. Several studies have used airborne TIR in combination with empirical SGD flux measurements to quantify SGD, reporting a consistently strong regression between SGD flux and SGD TIR plume area. We additionally discuss novel research opportunities for sUAS-TIR technologies, as applied to SGD flux. The combination of high spatial and temporal resolution capabilities, at relatively low costs, make sUAS-TIR a promising new technology to overcome the scaling challenges presented by empirical studies and modeling of SGD fluxes, and advance our understanding of the controls on SGD fluxes
Metabolic profiling predicts response to anti-tumor necrosis factor α therapy in patients with rheumatoid arthritis
<p>Objective: Antiâtumor necrosis factor (anti-TNF) therapies are highly effective in rheumatoid arthritis (RA) and psoriatic arthritis (PsA), but a significant number of patients exhibit only a partial or no therapeutic response. Inflammation alters local and systemic metabolism, and TNF plays a role in this. We undertook this study to determine if the patient's metabolic fingerprint prior to therapy could predict responses to anti-TNF agents.</p>
<p>Methods: Urine was collected from 16 RA patients and 20 PsA patients before and during therapy with infliximab or etanercept. Urine metabolic profiles were assessed using nuclear magnetic resonance spectroscopy. Discriminating metabolites were identified, and the relationship between metabolic profiles and clinical outcomes was assessed.</p>
<p>Results: Baseline urine metabolic profiles discriminated between RA patients who did or did not have a good response to anti-TNF therapy according to European League Against Rheumatism criteria, with a sensitivity of 88.9% and a specificity of 85.7%, with several metabolites contributing (in particular histamine, glutamine, xanthurenic acid, and ethanolamine). There was a correlation between baseline metabolic profiles and the magnitude of change in the Disease Activity Score in 28 joints from baseline to 12 months in RA patients (P = 0.04). In both RA and PsA, urinary metabolic profiles changed between baseline and 12 weeks of anti-TNF therapy. Within the responders, urinary metabolite changes distinguished between etanercept and infliximab treatment.</p>
<p>Conclusion: The clear relationship between urine metabolic profiles of RA patients at baseline and their response to anti-TNF therapy may allow development of novel approaches to the optimization of therapy. Differences in metabolic profiles during treatment with infliximab and etanercept in RA and PsA may reflect distinct mechanisms of action.</p>
Quantum-fluctuation-induced collisions and subsequent excitation gap of an elastic string between walls
An elastic string embedded between rigid walls is simulated by means of the
density-matrix renormalization group. The string collides against the walls
owing to the quantum-mechanical zero-point fluctuations. Such ``quantum
entropic'' interaction has come under thorough theoretical investigation in the
context of the stripe phase observed experimentally in doped cuprates. We found
that the excitation gap opens in the form of exponential singularity DeltaE ~
exp(-Ad^sigma) (d: wall spacing) with the exponent sigma =0.6(3), which is
substantially smaller than the meanfield value sigma=2. That is, the excitation
gap is much larger than that anticipated from meanfield, suggesting that the
string is subjected to robust pinning potential due to the quantum collisions.
This feature supports Zaanen's ``order out of disorder'' mechanism which would
be responsible to the stabilization of the stripe phase
Strange quarks and lattice QCD
The last few years have seen a dramatic improvement in our knowledge of the
strange form factors of the nucleon. With regard to the vector from factors the
level of agreement between theory and experiment gives us considerable
confidence in our ability to calculate with non-perturbative QCD. The
calculation of the strange scalar form factor has moved significantly in the
last two years, with the application of new techniques which yield values
considerably smaller than believed for the past 20 years. These new values turn
out to have important consequences for the detection of neutralinos, a
favourite dark matter candidate. Finally, very recent lattice studies have
resurrected interest in the famed H-dibaryon, with modern chiral extrapolation
of lattice data suggesting that it may be only slightly unbound. We review some
of the major sources of uncertainty in that chiral extrapolation.Comment: Invited talk at the Asia-Pacific few Body Conference, Seoul Kore
Robust irrigation system institutions: A global comparison
In many places irrigation systems rely on robust governance for continued existence. Elinor Ostrom listed design principles that should achieve robust governance, but doubted that any list could be both necessary and sufficient to result in robust governance. To date this assumption has never been formally tested. We conduct a meta-analysis and ultimately evaluate 62 case studies via fuzzy-set qualitative
comparative analysis to identify necessary/sufficient conditions for robust irrigation system governance. We identify four necessary conditions and seven configurations sufficient for robust governance. Further, we identify a union of conditions that, when absent, are likely to result in system failure.Sitti Rahma Ma'Muna, Adam Loch, Michael D. Youn
Pulse shape analysis in segmented detectors as a technique for background reduction in Ge double-beta decay experiments
The need to understand and reject backgrounds in Ge-diode detector
double-beta decay experiments has given rise to the development of pulse shape
analysis in such detectors to discern single-site energy deposits from
multiple-site deposits. Here, we extend this analysis to segmented Ge detectors
to study the effectiveness of combining segmentation with pulse shape analysis
to identify the multiplicity of the energy deposits.Comment: 12 pages, 13 figures, will be submitted to NI
Direct amplification of nodD from community DNA reveals the genetic diversity of Rhizobium leguminosarum in soil
Sequences of nodD, a gene found only in rhizobia, were amplified from total community DNA isolated from a pasture soil. The polymerase chain reaction (PCR) primers used, Y5 and Y6, match nodD from Rhizobium leguminosarum biovar trifolii, R. leguminosarum biovar viciae and Sinorhizobium meliloti. The PCR product was cloned and yielded 68 clones that were identified by restriction pattern as derived from biovar trifolii [11 restriction fragment length polymorphism (RFLP) types] and 15 clones identified as viciae (seven RFLP types). These identifications were confirmed by sequencing. There were no clones related to S. meliloti nodD. For comparison, 122 strains were isolated from nodules of white clover (Trifolium repens) growing at the field site, and 134 from nodules on trap plants of T. repens inoculated with the soil. The nodule isolates were of four nodD RFLP types, with 77% being of a single type. All four of these patterns were also found among the clones from soil DNA, and the same type was the most abundant, although it made up only 34% of the trifolii-like clones. We conclude that clover selects specific genotypes from the available soil population, and that R. leguminosarum biovar trifolii was approximately five times more abundant than biovar viciae in this pasture soil, whereas S. meliloti was rare
Pervasive and standalone computing: The perceptual effects of variable multimedia quality.
The introduction of multimedia on pervasive and mobile communication devices raises a number of perceptual quality issues, however, limited work has been done examining the 3-way interaction between use of equipment, quality of perception and quality of service. Our work measures levels of informational transfer (objective) and user satisfaction (subjective)when users are presented with multimedia video clips at three different frame rates, using four different display devices, simulating variation in participant mobility. Our results will show that variation in frame-rate does not impact a userâs level of information assimilation, however, does impact a usersâ perception of multimedia video âqualityâ. Additionally, increased visual immersion can be used to increase transfer of video information, but can negatively affect the usersâ perception of âqualityâ. Finally, we illustrate the significant affect of clip-content on the transfer of video, audio and textual information, placing into doubt the use of purely objective quality definitions when considering multimedia
presentations
Ground state of the random-bond spin-1 Heisenberg chain
Stochastic series expansion quantum Monte Carlo is used to study the ground
state of the antiferromagnetic spin-1 Heisenberg chain with bond disorder.
Typical spin- and string-correlations functions behave in accordance with
real-space renormalization group predictions for the random-singlet phase. The
average string-correlation function decays algebraically with an exponent of
-0.378(6), in very good agreement with the prediction of , while the average spin-correlation function is found to decay with an
exponent of about -1, quite different from the expected value of -2. By
implementing the concept of directed loops for the spin-1 chain we show that
autocorrelation times can be reduced by up to two orders of magnitude.Comment: 9 pages, 10 figure
- âŠ