222 research outputs found
An integrated plasma spectroscopic and capacitive sensing platform for water quality diagnostics
Even in modern times, the consumption of polluted water continues to inflict tremendous suffering on millions of people worldwide that is largely preventable with adequate sanitation practices, routine water quality diagnostics, and treatment. However, conventional water quality monitoring practices remain a time consuming endeavor, where water samples collected on-site are transported to off-site laboratories for evaluation with laboratory-scale chemical analysis devices. While considerable efforts have been made to miniaturize these devices for in-field use, many of the devices reported in the literature provide an incomplete assessment of a water contaminant\u27s environmental impact by focusing on identifying its chemical composition and providing limited or no data regarding the contaminant\u27s concentration.
A water contaminant\u27s chemical composition and concentration must be known to adequately assess its human health and environmental impact, as well as coordinating effective restoration and maintenance efforts. The field portable water diagnostic system reported here addresses this need with dual miniaturized plasma spectroscopic and capacitive sensing elements. Both sensing platforms capitalize on a water sample preconcentration stage that isolates contaminant particles from the liquid water solution as a porous thin film. This arrangement yields a more robust spectral emission signature from which the contaminant can be spectroscopically identified and allows the contaminant\u27s concentration to be estimated as a function of the film\u27s capacitance. A numerical contaminant concentration-to-capacitance model was developed for water samples containing single and multiple contaminant species to interpret the capacitive sensor\u27s output, incorporating the physical parameters of the contaminant material and the device\u27s capacitive analysis chamber which houses the porous contaminant film.
Prototypes of each sensing platform were developed separately to investigate first generation design flaws and optimize the spectroscopic and capacitive analysis procedures. Design modifications for each platform a were then incorporated into an integrated diagnostic system, combining both sensing platforms, to perform a complete water quality analysis of a pollutant\u27s chemical composition and concentration. Performance testing of the integrated diagnostic system focused on analyzing representatives of suspended and dissolved water contaminants that promote the incubation and spread of waterborne pathogens at concentration ranges comparable to regulations set by the United States Environmental Protection Agency
2003 Manifesto on the California Electricity Crisis
The authors, an ad-hocgroup of professionals with experience in regulatory and energy economics, share a common concern with the continuing turmoil facing the electricity industry ("the industry") in California. Most ofthe authorsendorsed the first California Electricity Manifesto issued on January 25, 2001. Almost two years have passed since that first Manifesto. While wholesale electric prices have moderated and California no longer faces the risk of blackouts, in many ways the industry is in worse shape now than it was at the start of 2001. As a result, the group of signatories continues to have a deep concern with the conflicting policy directions being pursued for the industry at both the State and Federal levels of government and the impact the uncertainties associated with these conflicting policies will have, long term, on the economy of California. Theauthorshave once again convened under the auspices of the Institute of Management, Innovation and Organization at the University of California, Berkeley, to put forward ourtheir ideas on a basic set of necessary policies to move the industry forward for the benefit of all Californians and the nation. The authors point out that theydo not pretend to be "representative." They do bring, however, a very diverse range of backgrounds and expertise.Technology and Industry, Regulatory Reform
Identification and analysis of hepatitis C virus NS3 helicase inhibitors using nucleic acid binding assays
Typical assays used to discover and analyze small molecules that inhibit the hepatitis C virus (HCV) NS3 helicase yield few hits and are often confounded by compound interference. Oligonucleotide binding assays are examined here as an alternative. After comparing fluorescence polarization (FP), homogeneous time-resolved fluorescence (HTRF®; Cisbio) and AlphaScreen® (Perkin Elmer) assays, an FP-based assay was chosen to screen Sigma’s Library of Pharmacologically Active Compounds (LOPAC) for compounds that inhibit NS3-DNA complex formation. Four LOPAC compounds inhibited the FP-based assay: aurintricarboxylic acid (ATA) (IC50 = 1.4 μM), suramin sodium salt (IC50 = 3.6 μM), NF 023 hydrate (IC50 = 6.2 μM) and tyrphostin AG 538 (IC50 = 3.6 μM). All but AG 538 inhibited helicase-catalyzed strand separation, and all but NF 023 inhibited replication of subgenomic HCV replicons. A counterscreen using Escherichia coli single-stranded DNA binding protein (SSB) revealed that none of the new HCV helicase inhibitors were specific for NS3h. However, when the SSB-based assay was used to analyze derivatives of another non-specific helicase inhibitor, the main component of the dye primuline, it revealed that some primuline derivatives (e.g. PubChem CID50930730) are up to 30-fold more specific for HCV NS3h than similarly potent HCV helicase inhibitors.National Institutes of Health [RO1 AI088001]; Research Growth Initiative Award [101X219] from the University of Wisconsin-Milwaukee Research Foundation; National Institutes of Health Molecular Libraries Initiative [U54 HG005031]. Funding for open access charge: University of Wisconsin-Milwaukee Research Foundation
Substituting carbohydrate at lunch for added protein increases fat oxidation during subsequent exercise in healthy males
Context
How pre-exercise meal composition influences metabolic and health responses to exercise later in the day is currently unclear.
Objective
Examine the effects of substituting carbohydrate for protein at lunch on subsequent exercise metabolism, appetite, and energy intake.
Methods
Twelve healthy males completed three trials in randomized, counterbalanced order. Following a standardized breakfast (779 ± 66 kcal; ∼08:15), participants consumed a lunch (1186 ± 140 kcal; ∼13:15) containing either 0.2 g·kg-1 carbohydrate and ∼2 g·kg-1 protein (LO-CARB), 2 g·kg-1 carbohydrate and ∼0.4 g·kg-1 protein (HI-CARB), or fasted (FAST). Participants later cycled at ∼60% V̇O2peak for 1 h (∼16:15) and post-exercise ad-libitum energy intake was measured (∼18:30). Substrate oxidation, subjective appetite, and plasma concentrations of glucose, insulin, non-esterified fatty acids (NEFA), peptide YY (PYY), glucagon-like peptide-1 (GLP-1), and acylated ghrelin (AG) were measured for 5 h post-lunch.
Results
Fat oxidation was greater during FAST (+11.66 ± 6.63 g) and LO-CARB (+8.00 ± 3.83 g) than HI-CARB (p < 0.001), with FAST greater than LO-CARB (+3.67 ± 5.07 g; p < 0.05). NEFA were lowest in HI-CARB and highest in FAST, with insulin demonstrating the inverse response (all p < 0.01). PYY and GLP-1 demonstrated a stepwise pattern, with LO-CARB greatest and FAST lowest (all p < 0.01). AG was lower during HI-CARB and LO-CARB versus FAST (p < 0.01). Energy intake in LO-CARB was lower than FAST (-383 ± 233 kcal; p < 0.001) and HI-CARB (-313 ± 284 kcal; p < 0.001).
Conclusion
Substituting carbohydrate for protein in a pre-exercise lunch increased fat oxidation, suppressed subjective and hormonal appetite, and reduced post-exercise energy intake
Quantifying interictal intracranial EEG to predict focal epilepsy
Intracranial EEG (IEEG) is used for 2 main purposes, to determine: (1) if
epileptic networks are amenable to focal treatment and (2) where to intervene.
Currently these questions are answered qualitatively and sometimes differently
across centers. There is a need for objective, standardized methods to guide
surgical decision making and to enable large scale data analysis across centers
and prospective clinical trials.
We analyzed interictal data from 101 patients with drug resistant epilepsy
who underwent presurgical evaluation with IEEG. We chose interictal data
because of its potential to reduce the morbidity and cost associated with ictal
recording. 65 patients had unifocal seizure onset on IEEG, and 36 were
non-focal or multi-focal. We quantified the spatial dispersion of implanted
electrodes and interictal IEEG abnormalities for each patient. We compared
these measures against the 5 Sense Score (5SS), a pre-implant estimate of the
likelihood of focal seizure onset, and assessed their ability to predict the
clinicians choice of therapeutic intervention and the patient outcome.
The spatial dispersion of IEEG electrodes predicted network focality with
precision similar to the 5SS (AUC = 0.67), indicating that electrode placement
accurately reflected pre-implant information. A cross-validated model combining
the 5SS and the spatial dispersion of interictal IEEG abnormalities
significantly improved this prediction (AUC = 0.79; p<0.05). The combined model
predicted ultimate treatment strategy (surgery vs. device) with an AUC of 0.81
and post-surgical outcome at 2 years with an AUC of 0.70. The 5SS, interictal
IEEG, and electrode placement were not correlated and provided complementary
information.
Quantitative, interictal IEEG significantly improved upon pre-implant
estimates of network focality and predicted treatment with precision
approaching that of clinical experts.Comment: 25 pages, 4 Figures, 1 tabl
The Pan-STARRS Moving Object Processing System
We describe the Pan-STARRS Moving Object Processing System (MOPS), a modern
software package that produces automatic asteroid discoveries and
identifications from catalogs of transient detections from next-generation
astronomical survey telescopes. MOPS achieves > 99.5% efficiency in producing
orbits from a synthetic but realistic population of asteroids whose
measurements were simulated for a Pan-STARRS4-class telescope. Additionally,
using a non-physical grid population, we demonstrate that MOPS can detect
populations of currently unknown objects such as interstellar asteroids.
MOPS has been adapted successfully to the prototype Pan-STARRS1 telescope
despite differences in expected false detection rates, fill-factor loss and
relatively sparse observing cadence compared to a hypothetical Pan-STARRS4
telescope and survey. MOPS remains >99.5% efficient at detecting objects on a
single night but drops to 80% efficiency at producing orbits for objects
detected on multiple nights. This loss is primarily due to configurable MOPS
processing limits that are not yet tuned for the Pan-STARRS1 mission.
The core MOPS software package is the product of more than 15 person-years of
software development and incorporates countless additional years of effort in
third-party software to perform lower-level functions such as spatial searching
or orbit determination. We describe the high-level design of MOPS and essential
subcomponents, the suitability of MOPS for other survey programs, and suggest a
road map for future MOPS development.Comment: 57 Pages, 26 Figures, 13 Table
Recommended from our members
Using atmospheric observations to quantify annual biogenic carbon dioxide fluxes on the Alaska North Slope
The continued warming of the Arctic could release vast stores of carbon into the atmosphere from high-latitude ecosystems, especially from thawing permafrost. Increasing uptake of carbon dioxide (CO2) by vegetation during longer growing seasons may partially offset such release of carbon. However, evidence of significant net annual release of carbon from site-level observations and model simulations across tundra ecosystems has been inconclusive. To address this knowledge gap, we combined top-down observations of atmospheric CO2 concentration enhancements from aircraft and a tall tower, which integrate ecosystem exchange over large regions, with bottom-up observed CO2 fluxes from tundra environments and found that the Alaska North Slope is not a consistent net source nor net sink of CO2 to the atmosphere (ranging from −6 to +6 Tg C yr−1 for 2012–2017). Our analysis suggests that significant biogenic CO2 fluxes from unfrozen terrestrial soils, and likely inland waters, during the early cold season (September–December) are major factors in determining the net annual carbon balance of the North Slope, implying strong sensitivity to the rapidly warming freeze-up period. At the regional level, we find no evidence of the previously reported large late-cold-season (January–April) CO2 emissions to the atmosphere during the study period. Despite the importance of the cold-season CO2 emissions to the annual total, the interannual variability in the net CO2 flux is driven by the variability in growing season fluxes. During the growing season, the regional net CO2 flux is also highly sensitive to the distribution of tundra vegetation types throughout the North Slope. This study shows that quantification and characterization of year-round CO2 fluxes from the heterogeneous terrestrial and aquatic ecosystems in the Arctic using both site-level and atmospheric observations are important to accurately project the Earth system response to future warming.</p
The association between symptomatic, severe hypoglycaemia and mortality in type 2 diabetes: retrospective epidemiological analysis of the ACCORD study
Objective To determine whether there is a link between hypoglycaemia and mortality among participants in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial
B Cells Regulate Neutrophilia during Mycobacterium tuberculosis Infection and BCG Vaccination by Modulating the Interleukin-17 Response
We have previously demonstrated that B cells can shape the immune response to Mycobacterium tuberculosis, including the level of neutrophil infiltration and granulomatous inflammation at the site of infection. The present study examined the mechanisms by which B cells regulate the host neutrophilic response upon exposure to mycobacteria and how neutrophilia may influence vaccine efficacy. To address these questions, a murine aerosol infection tuberculosis (TB) model and an intradermal (ID) ear BCG immunization mouse model, involving both the μMT strain and B cell-depleted C57BL/6 mice, were used. IL (interleukin)-17 neutralization and neutrophil depletion experiments using these systems provide evidence that B cells can regulate neutrophilia by modulating the IL-17 response during M. tuberculosis infection and BCG immunization. Exuberant neutrophilia at the site of immunization in B cell-deficient mice adversely affects dendritic cell (DC) migration to the draining lymph nodes and attenuates the development of the vaccine-induced Th1 response. The results suggest that B cells are required for the development of optimal protective anti-TB immunity upon BCG vaccination by regulating the IL-17/neutrophilic response. Administration of sera derived from M. tuberculosis-infected C57BL/6 wild-type mice reverses the lung neutrophilia phenotype in tuberculous μMT mice. Together, these observations provide insight into the mechanisms by which B cells and humoral immunity modulate vaccine-induced Th1 response and regulate neutrophila during M. tuberculosis infection and BCG immunization. © 2013 Kozakiewicz et al
- …