Sensitive skin and stratum corneum reactivity to household cleaning products.

PubMed

Goffin, V; Piérard-Franchimont, C; Piérard, G E

1996-02-01

Products intended for individuals with sensitive skin are being increasingly developed by formulators of household cleaning products. However, there is currently no consensus about the definition and recognition of the biological basis of sensitive skin. We sought to determine the relation between the nature of environmental threat perceived as aggressive by panelists, and the stratum corneum reactivity to household cleaning products as measured by the corneosurfametry test. Results indicate substantial differences in irritancy potential between proprietary products. Corneosurfametry data show significant differences in stratum corneum reactivity between, on the one hand, individuals with either non-sensitive skin or skin sensitive to climate/fabrics, and, on the other hand, individuals with detergent-sensitive skin. It is concluded that sensitive skin is not one single condition. Sound information in rating detergent-sensitive skin may be gained by corneosurfametry.

Digital Inverter Amine Sensing via Synergistic Responses by n and p Organic Semiconductors.

PubMed

Tremblay, Noah J; Jung, Byung Jun; Breysse, Patrick; Katz, Howard E

2011-11-22

Chemiresistors and sensitive OFETs have been substantially developed as cheap, scalable, and versatile sensing platforms. While new materials are expanding OFET sensing capabilities, the device architectures have changed little. Here we report higher order logic circuits utilizing OFETs sensitive to amine vapors. The circuits depend on the synergistic responses of paired p- and n-channel organic semiconductors, including an unprecedented analyte-induced current increase by the n-channel semiconductor. This represents the first step towards 'intelligent sensors' that utilize analog signal changes in sensitive OFETs to produce direct digital readouts suitable for further logic operations.

Digital Inverter Amine Sensing via Synergistic Responses by n and p Organic Semiconductors

PubMed Central

Tremblay, Noah J.; Jung, Byung Jun; Breysse, Patrick; Katz, Howard E.

2013-01-01

Chemiresistors and sensitive OFETs have been substantially developed as cheap, scalable, and versatile sensing platforms. While new materials are expanding OFET sensing capabilities, the device architectures have changed little. Here we report higher order logic circuits utilizing OFETs sensitive to amine vapors. The circuits depend on the synergistic responses of paired p- and n-channel organic semiconductors, including an unprecedented analyte-induced current increase by the n-channel semiconductor. This represents the first step towards ‘intelligent sensors’ that utilize analog signal changes in sensitive OFETs to produce direct digital readouts suitable for further logic operations. PMID:23754969

An observational radiative constraint on hydrologic cycle intensification

DOE PAGES

DeAngelis, Anthony M.; Qu, Xin; Zelinka, Mark D.; ...

2015-12-09

We report that intensification of the hydrologic cycle is a key dimension of climate change, with substantial impacts on human and natural systems. A basic measure of hydrologic cycle intensification is the increase in global-mean precipitation per unit surface warming, which varies by a factor of three in current-generation climate models (about 1–3 per cent per kelvin). Part of the uncertainty may originate from atmosphere–radiation interactions. As the climate warms, increases in shortwave absorption from atmospheric moistening will suppress the precipitation increase. This occurs through a reduction of the latent heating increase required to maintain a balanced atmospheric energy budget.more » Using an ensemble of climate models, here we show that such models tend to underestimate the sensitivity of solar absorption to variations in atmospheric water vapour, leading to an underestimation in the shortwave absorption increase and an overestimation in the precipitation increase. This sensitivity also varies considerably among models due to differences in radiative transfer parameterizations, explaining a substantial portion of model spread in the precipitation response. Consequently, attaining accurate shortwave absorption responses through improvements to the radiative transfer schemes could reduce the spread in the predicted global precipitation increase per degree warming for the end of the twenty-first century by about 35 per cent, and reduce the estimated ensemble-mean increase in this quantity by almost 40 per cent.« less

Pocked surface neutron detector

DOEpatents

McGregor, Douglas; Klann, Raymond

2003-04-08

The detection efficiency, or sensitivity, of a neutron detector material such as of Si, SiC, amorphous Si, GaAs, or diamond is substantially increased by forming one or more cavities, or holes, in its surface. A neutron reactive material such as of elemental, or any compound of, .sup.10 B, .sup.6 Li, .sup.6 LiF, U, or Gd is deposited on the surface of the detector material so as to be disposed within the cavities therein. The portions of the neutron reactive material extending into the detector material substantially increase the probability of an energetic neutron reaction product in the form of a charged particle being directed into and detected by the neutron detector material.

23 CFR 774.15 - Constructive use determinations.

Code of Federal Regulations, 2014 CFR

2014-04-01

... projected noise level increase attributable to the project substantially interferes with the use and enjoyment of a noise-sensitive facility of a property protected by Section 4(f), such as: (i) Hearing the... significance; (iv) Enjoyment of an urban park where serenity and quiet are significant attributes; or (v...

23 CFR 774.15 - Constructive use determinations.

Code of Federal Regulations, 2013 CFR

2013-04-01

... projected noise level increase attributable to the project substantially interferes with the use and enjoyment of a noise-sensitive facility of a property protected by Section 4(f), such as: (i) Hearing the... significance; (iv) Enjoyment of an urban park where serenity and quiet are significant attributes; or (v...

23 CFR 774.15 - Constructive use determinations.

Code of Federal Regulations, 2012 CFR

2012-04-01

... projected noise level increase attributable to the project substantially interferes with the use and enjoyment of a noise-sensitive facility of a property protected by Section 4(f), such as: (i) Hearing the... significance; (iv) Enjoyment of an urban park where serenity and quiet are significant attributes; or (v...

Highly sensitive determination of iron (III) ion based on phenanthroline probe: Surface-enhanced Raman spectroscopy methods

NASA Astrophysics Data System (ADS)

Chen, Lei; Ma, Ning; Park, Yeonju; Jin, Sila; Hwang, Hoon; Jiang, Dayu; Jung, Young Mee

2018-05-01

In this paper, we introduced Raman spectroscopy techniques that were based on the traditional Fe3 + determination method with phenanthroline as a probe. Interestingly, surface-enhanced Raman spectroscopy (SERS)-based approach exhibited excellent sensitivities to phenanthroline. Different detection mechanisms were observed for the RR and SERS techniques, in which the RR intensity increased with increasing Fe3 + concentration due to the observation of the RR effect of the phenanthroline-Fe2 + complex, whereas the SERS intensity increased with decreasing Fe3 + concentration due to the observation of the SERS effect of the uncomplexed phenanthroline. More importantly, the determination sensitivity was substantially improved in the presence of a SERS-active substrate, giving a detection limit as low as 0.001 μg/mL, which is 20 times lower than the limit of the UV-vis and RR methods. Furthermore, the proposed SERS method was free from other ions interference and can be used quality and sensitivity for the determination of the city tap water.

Population viability analysis of Lower Missouri River shovelnose sturgeon with initial application to the pallid sturgeon

USGS Publications Warehouse

Bajer, P.G.; Wildhaber, M.L.

2007-01-01

Demographic models for the shovelnose (Scaphirhynchus platorynchus) and pallid (S. albus) sturgeons in the Lower Missouri River were developed to conduct sensitivity analyses for both populations. Potential effects of increased fishing mortality on the shovelnose sturgeon were also evaluated. Populations of shovelnose and pallid sturgeon were most sensitive to age-0 mortality rates as well as mortality rates of juveniles and young adults. Overall, fecundity was a less sensitive parameter. However, increased fecundity effectively balanced higher mortality among sensitive age classes in both populations. Management that increases population-level fecundity and improves survival of age-0, juveniles, and young adults should most effectively benefit both populations. Evaluation of reproductive values indicated that populations of pallid sturgeon dominated by ages ≥35 could rapidly lose their potential for growth, particularly if recruitment remains low. Under the initial parameter values portraying current conditions the population of shovelnose sturgeon was predicted to decline by 1.65% annually, causing the commercial yield to also decline. Modeling indicated that the commercial yield could increase substantially if exploitation of females in ages ≤12 was highly restricted.

The role of protein digestibility and antacids on food allergy outcomes

PubMed Central

Untersmayr, Eva; Jensen-Jarolim, Erika

2010-01-01

Digestion assays with simulated gastric fluid have been introduced for characterization of food proteins to imitate the effect of stomach proteolysis on dietary compounds in vitro. By using these tests, dietary proteins can be categorized as digestion-resistant class 1 (true allergens triggering direct oral sensitization) or as labile class 2 allergens (nonsensitizing elicitors). Thus the results of these digestion assays mirror situations of intact gastric proteolysis. Alterations in the gastric milieu are frequently experienced during a lifetime either physiologically in the very young and the elderly or as a result of gastrointestinal pathologies. Additionally, acid-suppression medications are frequently used for treatment of dyspeptic disorders. By increasing the gastric pH, they interfere substantially with the digestive function of the stomach, leading to persistence of labile food protein during gastric transit. Indeed, both murine and human studies reveal that antiulcer medication increases the risk of food allergy induction. Gastric digestion substantially decreases the potential of food proteins to bind IgE, which increases the threshold dose of allergens required to elicit symptoms in patients with food allergy. Thus antiulcer agents impeding gastric protein digestion have a major effect on the sensitization and effector phase of food allergy. PMID:18539189

State-dependent climate sensitivity in past warm climates and its implications for future climate projections.

PubMed

Caballero, Rodrigo; Huber, Matthew

2013-08-27

Projections of future climate depend critically on refined estimates of climate sensitivity. Recent progress in temperature proxies dramatically increases the magnitude of warming reconstructed from early Paleogene greenhouse climates and demands a close examination of the forcing and feedback mechanisms that maintained this warmth and the broad dynamic range that these paleoclimate records attest to. Here, we show that several complementary resolutions to these questions are possible in the context of model simulations using modern and early Paleogene configurations. We find that (i) changes in boundary conditions representative of slow "Earth system" feedbacks play an important role in maintaining elevated early Paleogene temperatures, (ii) radiative forcing by carbon dioxide deviates significantly from pure logarithmic behavior at concentrations relevant for simulation of the early Paleogene, and (iii) fast or "Charney" climate sensitivity in this model increases sharply as the climate warms. Thus, increased forcing and increased slow and fast sensitivity can all play a substantial role in maintaining early Paleogene warmth. This poses an equifinality problem: The same climate can be maintained by a different mix of these ingredients; however, at present, the mix cannot be constrained directly from climate proxy data. The implications of strongly state-dependent fast sensitivity reach far beyond the early Paleogene. The study of past warm climates may not narrow uncertainty in future climate projections in coming centuries because fast climate sensitivity may itself be state-dependent, but proxies and models are both consistent with significant increases in fast sensitivity with increasing temperature.

Enhancing the Sensitivity of Fluorescence Bronchoscopy for Early Lung Cancer Detection Using a Fluorescent Deoxyglucose Analog

DTIC Science & Technology

2013-11-01

overexpression of glucose transporters ( Gluts ) and the increased activity of mitochondria- bound hexokinases in tumors (5, 6). Since 1976, 2-(fluorine-18...glucose transport through the cell membrane via Gluts has been reported as an important factor in the increase of FDG uptake in malignant tumors (5). In...capabilities of bronchoscopy without substantially increasing cost. Although there has been no work evaluating the use of 2-NBDG for lung cancer

Characterizing the isotopic composition of atmospheric ammonia emission sources using passive samplers and a combined oxidation-bacterial denitrifier approach

USDA-ARS?s Scientific Manuscript database

Ammonia (NH3) emissions are a substantial source of nitrogen pollution to sensitive terrestrial, aquatic, and marine ecosystems. Dependable quantification of NH3 sources is of growing importance due to recently observed increases in ammonium (NH4+) deposition rates that are directly proportional to ...

Controlled release in transdermal pressure sensitive adhesives using organosilicate nanocomposites.

PubMed

Shaikh, Sohel; Birdi, Anil; Qutubuddin, Syed; Lakatosh, Eric; Baskaran, Harihara

2007-12-01

Polydimethyl siloxane (PDMS) based pressure sensitive adhesives (PSA) incorporating organo-clays at different loadings were fabricated via solution casting. Partially exfoliated nanocomposites were obtained for the hydroxyl terminated PDMS in ethyl acetate solvent as determined by X-ray diffraction and atomic force microscopy. Drug release studies showed that the initial burst release was substantially reduced and the drug release could be controlled by the addition of organo-clay. Shear strength and shear adhesion failure temperature (SAFT) measurements indicated substantial improvement in adhesive properties of the PSA nanocomposite adhesives. Shear strength showed more than 200% improvement at the lower clay loadings and the SAFT increased by about 21% due to the reinforcement provided by the nano-dispersed clay platelets. It was found that by optimizing the level of the organosilicate additive to the polymer matrix, superior control over drug release kinetics and simultaneous improvements in adhesive properties could be attained for a transdermal PSA formulation.

Repeatability of automated perimetry: a comparison between standard automated perimetry with stimulus size III and V, matrix, and motion perimetry.

PubMed

Wall, Michael; Woodward, Kimberly R; Doyle, Carrie K; Artes, Paul H

2009-02-01

Standard automated perimetry (SAP) shows a marked increase in variability in damaged areas of the visual field. This study was conducted to test the hypothesis that larger stimuli are associated with more uniform variability, by investigating the retest variability of four perimetry tests: standard automated perimetry size III (SAP III), with the SITA standard strategy; SAP size V (SAP V), with the full-threshold strategy; Matrix (FDT II), and Motion perimetry. One eye each of 120 patients with glaucoma was examined on the same day with these four perimetric tests and retested 1 to 8 weeks later. The decibel scales were adjusted to make the test's scales numerically similar. Retest variability was examined by establishing the distributions of retest threshold estimates, for each threshold level observed at the first test. The 5th and 95th percentiles of the retest distribution were used as point-wise limits of retest variability. Regression analyses were performed to quantify the relationship between visual field sensitivity and variability. With SAP III, the retest variability increased substantially with reducing sensitivity. Corresponding increases with SAP V, Matrix, and Motion perimetry were considerably smaller or absent. With SAP III, sensitivity explained 22% of the retest variability (r(2)), whereas corresponding data for SAP V, Matrix, and Motion perimetry were 12%, 2%, and 2%, respectively. Variability of Matrix and Motion perimetry does not increase as substantially as that of SAP III in damaged areas of the visual field. Increased sampling with the larger stimuli of these techniques is the likely explanation for this finding. These properties may make these stimuli excellent candidates for early detection of visual field progression.

The design of the MEG II experiment

NASA Astrophysics Data System (ADS)

Baldini, A. M.; Baracchini, E.; Bemporad, C.; Berg, F.; Biasotti, M.; Boca, G.; Cattaneo, P. W.; Cavoto, G.; Cei, F.; Chiappini, M.; Chiarello, G.; Chiri, C.; Cocciolo, G.; Corvaglia, A.; de Bari, A.; De Gerone, M.; D'Onofrio, A.; Francesconi, M.; Fujii, Y.; Galli, L.; Gatti, F.; Grancagnolo, F.; Grassi, M.; Grigoriev, D. N.; Hildebrandt, M.; Hodge, Z.; Ieki, K.; Ignatov, F.; Iwai, R.; Iwamoto, T.; Kaneko, D.; Kasami, K.; Kettle, P.-R.; Khazin, B. I.; Khomutov, N.; Korenchenko, A.; Kravchuk, N.; Libeiro, T.; Maki, M.; Matsuzawa, N.; Mihara, S.; Milgie, M.; Molzon, W.; Mori, Toshinori; Morsani, F.; Mtchedilishvili, A.; Nakao, M.; Nakaura, S.; Nicolò, D.; Nishiguchi, H.; Nishimura, M.; Ogawa, S.; Ootani, W.; Panareo, M.; Papa, A.; Pepino, A.; Piredda, G.; Popov, A.; Raffaelli, F.; Renga, F.; Ripiccini, E.; Ritt, S.; Rossella, M.; Rutar, G.; Sawada, R.; Signorelli, G.; Simonetta, M.; Tassielli, G. F.; Uchiyama, Y.; Usami, M.; Venturini, M.; Voena, C.; Yoshida, K.; Yudin, Yu. V.; Zhang, Y.

2018-05-01

The MEG experiment, designed to search for the {μ ^+ → e^+ γ } decay, completed data-taking in 2013 reaching a sensitivity level of {5.3× 10^{-13}} for the branching ratio. In order to increase the sensitivity reach of the experiment by an order of magnitude to the level of 6× 10^{-14}, a total upgrade, involving substantial changes to the experiment, has been undertaken, known as MEG II. We present both the motivation for the upgrade and a detailed overview of the design of the experiment and of the expected detector performance.

Configuring the Long-Baseline Neutrino Experiment

NASA Astrophysics Data System (ADS)

Barger, Vernon; Bhattacharya, Atri; Chatterjee, Animesh; Gandhi, Raj; Marfatia, Danny; Masud, Mehedi

2014-01-01

We study the neutrino oscillation physics performance of the Long-Baseline Neutrino Experiment in various configurations. In particular, we compare the case of a surface detector at the far site augmented by a near detector, to that with the far site detector placed deep underground but no near detector. In the latter case, information from atmospheric neutrino events is also utilized. For values of θ13 favored by reactor experiments and a 100 kt-yr exposure, we find roughly equivalent sensitivities to the neutrino mass hierarchy, the octant of θ23, and to CP violation. We also find that as the exposure is increased, the near detector helps increase the sensitivity to CP violation substantially more than atmospheric neutrinos.

Employee responses to health insurance premium increases.

PubMed

Goldman, Dana P; Leibowitz, Arleen A; Robalino, David A

2004-01-01

To determine the sensitivity of employees' health insurance decisions--including the decision to not choose health maintenance organization or fee-for-service coverage--during periods of rapidly escalating healthcare costs. A retrospective cohort study of employee plan choices at a single large firm with a "cafeteria-style" benefits plan wherein employees paid all the additional cost of purchasing more generous insurance. We modeled the probability that an employee would drop coverage or switch plans in response to employee premium increases using data from a single large US company with employees across 47 states during the 3-year period of 1989 through 1991, a time of large premium increases within and across plans. Premium increases induced substantial plan switching. Single employees were more likely to respond to premium increases by dropping coverage, whereas families tended to switch to another plan. Premium increases of 10% induced 7% of single employees to drop or severely cut back on coverage; 13% to switch to another plan; and 80% to remain in their existing plan. Similar figures for those with family coverage were 11%, 12%, and 77%, respectively. Simulation results that control for known covariates show similar increases. When faced with a dramatic increase in premiums--on the order of 20%--nearly one fifth of the single employees dropped coverage compared with 10% of those with family coverage. Employee coverage decisions are sensitive to rapidly increasing premiums, and single employees may be likely to drop coverage. This finding suggests that sustained premium increases could induce substantial increases in the number of uninsured individuals.

State-dependent climate sensitivity in past warm climates and its implications for future climate projections

PubMed Central

Caballero, Rodrigo; Huber, Matthew

2013-01-01

Projections of future climate depend critically on refined estimates of climate sensitivity. Recent progress in temperature proxies dramatically increases the magnitude of warming reconstructed from early Paleogene greenhouse climates and demands a close examination of the forcing and feedback mechanisms that maintained this warmth and the broad dynamic range that these paleoclimate records attest to. Here, we show that several complementary resolutions to these questions are possible in the context of model simulations using modern and early Paleogene configurations. We find that (i) changes in boundary conditions representative of slow “Earth system” feedbacks play an important role in maintaining elevated early Paleogene temperatures, (ii) radiative forcing by carbon dioxide deviates significantly from pure logarithmic behavior at concentrations relevant for simulation of the early Paleogene, and (iii) fast or “Charney” climate sensitivity in this model increases sharply as the climate warms. Thus, increased forcing and increased slow and fast sensitivity can all play a substantial role in maintaining early Paleogene warmth. This poses an equifinality problem: The same climate can be maintained by a different mix of these ingredients; however, at present, the mix cannot be constrained directly from climate proxy data. The implications of strongly state-dependent fast sensitivity reach far beyond the early Paleogene. The study of past warm climates may not narrow uncertainty in future climate projections in coming centuries because fast climate sensitivity may itself be state-dependent, but proxies and models are both consistent with significant increases in fast sensitivity with increasing temperature. PMID:23918397

Ranking site vulnerability to increasing temperatures in southern Appalachian brook trout streams in Virginia: An exposure-sensitivity approach

Treesearch

Bradly A. Trumbo; Keith H. Nislow; Jonathan Stallings; Mark Hudy; Eric P. Smith; Dong-Yun Kim; Bruce Wiggins; Charles A. Dolloff

2014-01-01

Models based on simple air temperature–water temperature relationships have been useful in highlighting potential threats to coldwater-dependent species such as Brook Trout Salvelinus fontinalis by predicting major losses of habitat and substantial reductions in geographic distribution. However, spatial variability in the relationship between changes...

10 CFR 71.51 - Additional requirements for Type B packages.

Code of Federal Regulations, 2014 CFR

2014-01-01

... sensitivity of 10−6 A2 per hour, no significant increase in external surface radiation levels, and no substantial reduction in the effectiveness of the packaging; and (2) Section 71.73 (“Hypothetical accident... radioactive material exceeding a total amount A2 in 1 week, and no external radiation dose rate exceeding 10 m...

10 CFR 71.51 - Additional requirements for Type B packages.

Code of Federal Regulations, 2012 CFR

2012-01-01

... sensitivity of 10−6 A2 per hour, no significant increase in external surface radiation levels, and no substantial reduction in the effectiveness of the packaging; and (2) Section 71.73 (“Hypothetical accident... radioactive material exceeding a total amount A2 in 1 week, and no external radiation dose rate exceeding 10 m...

10 CFR 71.51 - Additional requirements for Type B packages.

Code of Federal Regulations, 2013 CFR

2013-01-01

... sensitivity of 10−6 A2 per hour, no significant increase in external surface radiation levels, and no substantial reduction in the effectiveness of the packaging; and (2) Section 71.73 (“Hypothetical accident... radioactive material exceeding a total amount A2 in 1 week, and no external radiation dose rate exceeding 10 m...

10 CFR 71.51 - Additional requirements for Type B packages.

Code of Federal Regulations, 2011 CFR

2011-01-01

... sensitivity of 10−6 A2 per hour, no significant increase in external surface radiation levels, and no substantial reduction in the effectiveness of the packaging; and (2) Section 71.73 (“Hypothetical accident... radioactive material exceeding a total amount A2 in 1 week, and no external radiation dose rate exceeding 10 m...

10 CFR 71.51 - Additional requirements for Type B packages.

Code of Federal Regulations, 2010 CFR

2010-01-01

... sensitivity of 10−6 A2 per hour, no significant increase in external surface radiation levels, and no substantial reduction in the effectiveness of the packaging; and (2) Section 71.73 (“Hypothetical accident... radioactive material exceeding a total amount A2 in 1 week, and no external radiation dose rate exceeding 10 m...

Test-retest of self-reported exposure to artificial tanning devices, self-tanning creams, and sun sensitivity showed consistency.

PubMed

Beane Freeman, Laura E; Dennis, Leslie K; Lynch, Charles F; Lowe, John B; Clarke, William R

2005-04-01

Exposure to ultraviolet radiation has consistently been linked to an increased risk of melanoma. Epidemiologic studies are susceptible to measurement error, which can distort the magnitude of observed effects. Although the reliability of self-report of many sun exposure factors has been previously described in several studies, self-report of use of artificial tanning devices and self-tanning creams has been less well characterized. A mailed survey was re-administered 2-4 weeks after completion of the initial survey to 76 randomly selected participants in a case-control study of melanoma. Cases and controls were individuals diagnosed in 1999 and 2000 who were ascertained from the Iowa Cancer Registry in 2002. We assessed the consistency of self-reported use of sunlamps and self-tanning creams, sun sensitivity, and history of sunburns. There was substantial reliability in reporting the use of sunlamps or self-tanning creams (cases: Kappa (kappa)=1.0 for both exposures; controls: kappa=0.71 and 0.87, respectively). kappa estimates of 0.62-0.78 were found for overall reliability of several sun sensitivity factors. Overall, the survey instrument demonstrated substantial reproducibility for factors related to the use of sunlamps or tanning beds, self-tanning creams, and sun sensitivity factors.

Population level differences in thermal sensitivity of energy assimilation in terrestrial salamanders.

PubMed

Clay, Timothy A; Gifford, Matthew E

2017-02-01

Thermal adaptation predicts that thermal sensitivity of physiological traits should be optimized to thermal conditions most frequently experienced. Furthermore, thermodynamic constraints predict that species with higher thermal optima should have higher performance maxima and narrower performance breadths. We tested these predictions by examining the thermal sensitivity of energy assimilation between populations within two species of terrestrial-lungless salamanders, Plethodon albagula and P. montanus. Within P. albagula, we examined populations that were latitudinally separated by >450km. Within P. montanus, we examined populations that were elevationally separated by >900m. Thermal sensitivity of energy assimilation varied substantially between populations of P. albagula separated latitudinally, but did not vary between populations of P. montanus separated elevationally. Specifically, in P. albagula, the lower latitude population had a higher thermal optimum, higher maximal performance, and narrower performance breadth compared to the higher latitude population. Furthermore, across all individuals as thermal optima increased, performance maxima also increased, providing support for the theory that "hotter is better". Copyright © 2016 Elsevier Ltd. All rights reserved.

Increased alignment sensitivity improves the usage of genome alignments for comparative gene annotation.

PubMed

Sharma, Virag; Hiller, Michael

2017-08-21

Genome alignments provide a powerful basis to transfer gene annotations from a well-annotated reference genome to many other aligned genomes. The completeness of these annotations crucially depends on the sensitivity of the underlying genome alignment. Here, we investigated the impact of the genome alignment parameters and found that parameters with a higher sensitivity allow the detection of thousands of novel alignments between orthologous exons that have been missed before. In particular, comparisons between species separated by an evolutionary distance of >0.75 substitutions per neutral site, like human and other non-placental vertebrates, benefit from increased sensitivity. To systematically test if increased sensitivity improves comparative gene annotations, we built a multiple alignment of 144 vertebrate genomes and used this alignment to map human genes to the other 143 vertebrates with CESAR. We found that higher alignment sensitivity substantially improves the completeness of comparative gene annotations by adding on average 2382 and 7440 novel exons and 117 and 317 novel genes for mammalian and non-mammalian species, respectively. Our results suggest a more sensitive alignment strategy that should generally be used for genome alignments between distantly-related species. Our 144-vertebrate genome alignment and the comparative gene annotations (https://bds.mpi-cbg.de/hillerlab/144VertebrateAlignment_CESAR/) are a valuable resource for comparative genomics. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Fecal immunochemical tests in combination with blood tests for colorectal cancer and advanced adenoma detection—systematic review

PubMed Central

Niedermaier, Tobias; Weigl, Korbinian; Hoffmeister, Michael; Brenner, Hermann

2017-01-01

Background Colorectal cancer (CRC) is a common but largely preventable cancer. Although fecal immunochemical tests (FITs) detect the majority of CRCs, they miss some of the cancers and most advanced adenomas (AAs). The potential of blood tests in complementing FITs for the detection of CRC or AA has not yet been systematically investigated. Methods We conducted a systematic review of performance of FIT combined with an additional blood test for CRC and AA detection versus FIT alone. PubMed and Web of Science were searched until June 9, 2017. Results Some markers substantially increased sensitivity for CRC when combined with FIT, albeit typically at a major loss of specificity. For AA, no relevant increase in sensitivity could be achieved. Conclusion Combining FIT and blood tests might be a promising approach to enhance sensitivity of CRC screening, but comprehensive evaluation of promising marker combinations in screening populations is needed. PMID:29435309

Inhomogeneous Forcing and Transient Climate Sensitivity

NASA Technical Reports Server (NTRS)

Shindell, Drew T.

2014-01-01

Understanding climate sensitivity is critical to projecting climate change in response to a given forcing scenario. Recent analyses have suggested that transient climate sensitivity is at the low end of the present model range taking into account the reduced warming rates during the past 10-15 years during which forcing has increased markedly. In contrast, comparisons of modelled feedback processes with observations indicate that the most realistic models have higher sensitivities. Here I analyse results from recent climate modelling intercomparison projects to demonstrate that transient climate sensitivity to historical aerosols and ozone is substantially greater than the transient climate sensitivity to CO2. This enhanced sensitivity is primarily caused by more of the forcing being located at Northern Hemisphere middle to high latitudes where it triggers more rapid land responses and stronger feedbacks. I find that accounting for this enhancement largely reconciles the two sets of results, and I conclude that the lowest end of the range of transient climate response to CO2 in present models and assessments (less than 1.3 C) is very unlikely.

Technological advances in cosmogenic neutron detectors for measuring soil water content

NASA Astrophysics Data System (ADS)

Zreda, M. G.; Schrön, M.; Köhli, M.

2017-12-01

The cosmic-ray neutron probe is used for measuring area-average soil water content at the hectometer scale. Early work showed a simple exponential decrease with distance of the instrument's sensitivity and a footprint 300 m in radius. Recent research suggested a much higher sensitivity to local neutrons and reduced footprint. We show results confirming the high sensitivity to local neutrons, describe two ways to reduce local and increase far-field effects, and propose ways of measuring neutrons at different spatial scales. Measurements with moderated detectors across a 10-m-wide creek and a 2-m-wide water tank show a decrease by 30% and 20%, respectively, of neutron intensity over water compared to that over land nearby. These results mean that the detector is sensitive to meter-scale heterogeneities of water content. This sensitivity can be reduced by rising the detector or by shielding it from local neutrons. The effect of local water distributions on the measured neutron intensity decreases with height. In the water tank experiment it disappeared almost completely at the height of 2 m, leading to the conjecture that the height roughly equal to the horizontal scale of heterogeneity would eliminate the sensitivity. This may or may not be practical. Shielding the detector below by a hydrogenous material removes a substantial fraction of the local neutrons. The shielded detector has a reduced count rate, reduced sensitivity to local neutrons and increased sensitivity to neutrons farther afield, and a larger footprint. Such a detector could be preferable to the current cosmogenic-neutron probe under heterogeneous soil water conditions. The shielding experiments also inspired the development of a local-area neutron detector. It has hydrogenous neutron shields on all sides except the bottom, substantially blocking the neutrons coming from afar, while allowing the neutrons coming directly from below. Its footprint is equal to its physical dimension when the detector is placed on the surface. Once this detector is calibrated, it can be useful in calibrating the wide-area detector, for example over stony soils that are difficult to sample physically for water content determination, and in high-resolution mapping of neutron intensity and soil moisture.

Grating angle magnification enhanced angular sensor and scanner

NASA Technical Reports Server (NTRS)

Sun, Ke-Xun (Inventor); Byer, Robert L. (Inventor)

2009-01-01

An angular magnification effect of diffraction is exploited to provide improved sensing and scanning. This effect is most pronounced for a normal or near-normal incidence angle in combination with a grazing diffraction angle, so such configurations are preferred. Angular sensitivity can be further enhanced because the width of the diffracted beam can be substantially less than the width of the incident beam. Normal incidence configurations with two symmetric diffracted beams are preferred, since rotation and vertical displacement can be readily distinguished. Increased sensitivity to vertical displacement can be provided by incorporating an interferometer into the measurement system. Quad cell detectors can be employed to provide sensitivity to rotation about the grating surface normal. A 2-D grating can be employed to provide sensitivity to angular displacements in two different planes (e.g., pitch and yaw). Combined systems can provide sensitivity to vertical displacement and to all three angular degrees of freedom.

Determination of iridium in mafic rocks by atomic absorption

USGS Publications Warehouse

Grimaldi, F.S.; Schnepfe, M.M.

1970-01-01

Iridium is determined in mineralized mafic rocks by atomic absorption after fire-assay concentration into a gold bead. Interelement interferences in the atomic-absorption determination are removed and Ir sensitivity is increased by buffering the solutions with a mixture of copper and sodium sulphates. Substantial amounts of Ag, Al, Au, Bi, Ca, Cd, Co, Cr, Fe, Ho, Hg, K, La, Mg, Mn, Mo, Ni, Pb, Te, Ti, V, Y, Zn and platinum metals can be tolerated in the atomic-absorption determination. The sensitivity and detection limits are 3.2 and 0.25 ppm of Ir, respectively. ?? 1970.

Holograms for laser diode: Single mode optical fiber coupling

NASA Technical Reports Server (NTRS)

Fuhr, P. L.

1982-01-01

The low coupling efficiency of semiconductor laser emissions into a single mode optical fibers place a severe restriction on their use. Associated with these conventional optical coupling techniques are stringent alignment sensitivities. Using holographic elements, the coupling efficiency may be increased and the alignment sensitivity greatly reduced. Both conventional and computer methods used in the generation of the holographic couplers are described and diagrammed. The reconstruction geometries used are shown to be somewhat restrictive but substantially less rigid than their conventional optical counterparts. Single and double hologram techniques are examined concerning their respective ease of fabrication and relative merits.

Genetic stability of genome-scale deoptimized RNA virus vaccine candidates under selective pressure

PubMed Central

Le Nouën, Cyril; McCarty, Thomas; Brown, Michael; Smith, Melissa Laird; Lleras, Roberto; Dolan, Michael A.; Mehedi, Masfique; Yang, Lijuan; Luongo, Cindy; Liang, Bo; Munir, Shirin; DiNapoli, Joshua M.; Mueller, Steffen; Wimmer, Eckard; Collins, Peter L.; Buchholz, Ursula J.

2017-01-01

Recoding viral genomes by numerous synonymous but suboptimal substitutions provides live attenuated vaccine candidates. These vaccine candidates should have a low risk of deattenuation because of the many changes involved. However, their genetic stability under selective pressure is largely unknown. We evaluated phenotypic reversion of deoptimized human respiratory syncytial virus (RSV) vaccine candidates in the context of strong selective pressure. Codon pair deoptimized (CPD) versions of RSV were attenuated and temperature-sensitive. During serial passage at progressively increasing temperature, a CPD RSV containing 2,692 synonymous mutations in 9 of 11 ORFs did not lose temperature sensitivity, remained genetically stable, and was restricted at temperatures of 34 °C/35 °C and above. However, a CPD RSV containing 1,378 synonymous mutations solely in the polymerase L ORF quickly lost substantial attenuation. Comprehensive sequence analysis of virus populations identified many different potentially deattenuating mutations in the L ORF as well as, surprisingly, many appearing in other ORFs. Phenotypic analysis revealed that either of two competing mutations in the virus transcription antitermination factor M2-1, outside of the CPD area, substantially reversed defective transcription of the CPD L gene and substantially restored virus fitness in vitro and in case of one of these two mutations, also in vivo. Paradoxically, the introduction into Min L of one mutation each in the M2-1, N, P, and L proteins resulted in a virus with increased attenuation in vivo but increased immunogenicity. Thus, in addition to providing insights on the adaptability of genome-scale deoptimized RNA viruses, stability studies can yield improved synthetic RNA virus vaccine candidates. PMID:28049853

Impacts of enhanced fertilizer applications on tropospheric ozone and crop damage over sub-Saharan Africa

NASA Astrophysics Data System (ADS)

Huang, Yaoxian; Hickman, Jonathan E.; Wu, Shiliang

2018-05-01

Fertilizer-induced nitrogen oxides (NOx) emissions in sub-Saharan Africa are expected to increase substantially in the coming decades, driven by increasing application of fertilizers to increase crop yields in an effort to attain food security across the continent. In many parts of sub-Saharan Africa, surface ozone (O3) is sensitive to increasing atmospheric concentrations of NOx. In this study, we employ the GEOS-Chem chemical transport model to conduct a preliminary investigation of the impacts on O3 air quality and the consequential crop damage associated with increasing fertilizer-induced NOx emissions in sub-Saharan Africa. Our simulation results, constrained by field NO flux measurements for the years 2011 and 2012 in response to a variety of fertilizer application rates in western Kenya, show that the enhancements in NO flux with fertilizer application rate of 150 kg N ha-1 can increase surface NOx and O3 concentrations by up to 0.36 and 2.8 ppbv respectively during the growing season. At the same time, accumulated O3 exposure during the crop growing season (expressed as AOT40 values) could increase by up to 496 ppb h, leading to crop yield decline of about 0.8% for O3-sensitive crops. Our results suggest that, when accounting for the consequential impacts on surface O3 air quality and crop damage over sub-Saharan Africa, agricultural intensification is possible without substantial impacts on crop productivity because the relatively small decline of crop yield resulting from O3 damage appears unlikely to outweigh the gain in crop yield from fertilization.

Controlled Release in Transdermal Pressure Sensitive Adhesives using Organosilicate Nanocomposites

PubMed Central

Shaikh, Sohel; Birdi, Anil; Qutubuddin, Syed; Lakatosh, Eric; Baskaran, Harihara

2010-01-01

Polydimethyl siloxane (PDMS) based pressure sensitive adhesives (PSA) incorporating organo-clays at different loadings were fabricated via solution casting. Partially exfoliated nanocomposites were obtained for the hydroxyl terminated PDMS in ethyl acetate solvent as determined by X-ray diffraction (XRD) and atomic force microscopy (AFM). Drug release studies showed that the initial burst release was substantially reduced and the drug release could be controlled by the addition of organo-clay. Shear strength and shear adhesion failure temperature (SAFT) measurements indicated substantial improvement in adhesive properties of the PSA nanocomposite adhesives. Shear strength showed more than 200 % improvement at the lower clay loadings and the SAFT increased by about 21% due to the reinforcement provided by the nano-dispersed clay platelets. It was found that by optimizing the level of the organosilicate additive to the polymer matrix, superior control over drug release kinetics and simultaneous improvements in adhesive properties could be attained for a transdermal PSA formulation. PMID:17786555

Breakthrough Capability for UVOIR Space Astronomy: Reaching the Darkest Sky

NASA Technical Reports Server (NTRS)

Greenhouse, Matthew A.; Benson, Scott W.; Englander, Jacob; Falck, Robert D.; Fixsen, Dale J.; Gardner, Jonathan P.; Kruk, Jeffery W.; Oleson, Steven R.; Thronson, Harley A.

2015-01-01

We describe how availability of new solar electric propulsion (SEP) technology can substantially increase the science capability of space astronomy missions working within the near-UV to far-infrared (UVOIR) spectrum by making dark sky orbits accessible for the first time. We present two case studies in which SEP is used to enable a 700 kg Explorer-class and 7000 kg flagship-class observatory payload to reach an orbit beyond where the zodiacal dust limits observatory sensitivity. The resulting scientific performance advantage relative to a Sun-Earth L2 point (SEL2) orbit is presented and discussed. We find that making SEP available to astrophysics Explorers can enable this small payload program to rival the science performance of much larger long development-time systems. Similarly, we find that astrophysics utilization of high power SEP being developed for the Asteroid Redirect Robotics Mission (ARRM) can have a substantial impact on the sensitivity performance of heavier flagship-class astrophysics payloads such as the UVOIR successor to the James Webb Space Telescope.

Multistrip western blotting to increase quantitative data output.

PubMed

Kiyatkin, Anatoly; Aksamitiene, Edita

2009-01-01

The qualitative and quantitative measurements of protein abundance and modification states are essential in understanding their functions in diverse cellular processes. Typical western blotting, though sensitive, is prone to produce substantial errors and is not readily adapted to high-throughput technologies. Multistrip western blotting is a modified immunoblotting procedure based on simultaneous electrophoretic transfer of proteins from multiple strips of polyacrylamide gels to a single membrane sheet. In comparison with the conventional technique, Multistrip western blotting increases the data output per single blotting cycle up to tenfold, allows concurrent monitoring of up to nine different proteins from the same loading of the sample, and substantially improves the data accuracy by reducing immunoblotting-derived signal errors. This approach enables statistically reliable comparison of different or repeated sets of data, and therefore is beneficial to apply in biomedical diagnostics, systems biology, and cell signaling research.

Substantial replacement of lactose with fat in a high-lactose milk replacer diet increases liver fat accumulation but does not affect insulin sensitivity in veal calves.

PubMed

Pantophlet, A J; Gerrits, W J J; Vonk, R J; van den Borne, J J G C

2016-12-01

In veal calves, the major portion of digestible energy intake originates from milk replacer (MR), with lactose and fat contributing approximately 45 and 35%, respectively. In veal calves older than 4 mo, prolonged high intakes of MR may lead to problems with glucose homeostasis and insulin sensitivity, ultimately resulting in sustained insulin resistance, hepatic steatosis, and impaired animal performance. The contribution of each of the dietary energy sources (lactose and fat) to deteriorated glucose homeostasis and insulin resistance is currently unknown. Therefore, an experiment was designed to compare the effects of a high-lactose and a high-fat MR on glucose homeostasis and insulin sensitivity in veal calves. Sixteen male Holstein-Friesian calves (120±2.8kg of BW) were assigned to either a high-lactose (HL) or a high-fat (HF) MR for 13 consecutive weeks. After at least 7 wk of adaptation, whole-body insulin sensitivity and insulin secretion were assessed by euglycemic-hyperinsulinemic and hyperglycemic clamps, respectively. Postprandial blood samples were collected to assess glucose, insulin, and triglyceride responses to feeding, and 24-h urine was collected to quantify urinary glucose excretion. At the end of the trial, liver and muscle biopsies were taken to assess triglyceride contents in these tissues. Long-term exposure of calves to HF or HL MR did not affect whole-body insulin sensitivity (averaging 4.2±0.5×10 -2 [(mg/kg∙min)/(μU/mL)]) and insulin secretion. Responses to feeding were greater for plasma glucose and tended to be greater for plasma insulin in HL calves than in HF calves. Urinary glucose excretion was substantially higher in HL calves (75±13g/d) than in HF calves (21±6g/d). Muscle triglyceride content was not affected by treatment and averaged 4.5±0.6g/kg, but liver triglyceride content was higher in HF calves (16.4±0.9g/kg) than in HL calves (11.2±0.7g/kg), indicating increased hepatic fat accumulation. We conclude that increasing the contribution of fat to the digestible energy intake from the MR from 20 to 50%, at the expense of lactose does not affect whole-body insulin sensitivity and insulin secretion in calves. However, a high-lactose MR increases postprandial glucose and insulin responses, whereas a high-fat MR increases fat accumulation in liver but not muscle. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilcox, Kevin R.; Shi, Zheng; Gherardi, Laureano A.

Climatic changes are altering Earth's hydrological cycle, resulting in altered precipitation amounts, increased interannual variability of precipitation, and more frequent extreme precipitation events. These trends will likely continue into the future, having substantial impacts on net primary productivity (NPP) and associated ecosystem services such as food production and carbon sequestration. Frequently, experimental manipulations of precipitation have linked altered precipitation regimes to changes in NPP. Yet, findings have been diverse and substantial uncertainty still surrounds generalities describing patterns of ecosystem sensitivity to altered precipitation. Additionally, we do not know whether previously observed correlations between NPP and precipitation remain accurate when precipitationmore » changes become extreme. We synthesized results from 83 case studies of experimental precipitation manipulations in grasslands worldwide. Here, we used meta-analytical techniques to search for generalities and asymmetries of aboveground NPP (ANPP) and belowground NPP (BNPP) responses to both the direction and magnitude of precipitation change. Sensitivity (i.e., productivity response standardized by the amount of precipitation change) of BNPP was similar under precipitation additions and reductions, but ANPP was more sensitive to precipitation additions than reductions; this was especially evident in drier ecosystems. Additionally, overall relationships between the magnitude of productivity responses and the magnitude of precipitation change were saturating in form. The saturating form of this relationship was likely driven by ANPP responses to very extreme precipitation increases, although there were limited studies imposing extreme precipitation change, and there was considerable variation among experiments. Finally, this highlights the importance of incorporating gradients of manipulations, ranging from extreme drought to extreme precipitation increases into future climate change experiments. Additionally, policy and land management decisions related to global change scenarios should consider how ANPP and BNPP responses may differ, and that ecosystem responses to extreme events might not be predicted from relationships found under moderate environmental changes.« less

Subchronic sleep restriction causes tissue-specific insulin resistance.

PubMed

Rao, Madhu N; Neylan, Thomas C; Grunfeld, Carl; Mulligan, Kathleen; Schambelan, Morris; Schwarz, Jean-Marc

2015-04-01

Short sleep duration is associated with an increased risk of type 2 diabetes. Subchronic sleep restriction (SR) causes insulin resistance, but the mechanisms and roles of specific tissues are unclear. The purpose of this article was to determine whether subchronic SR altered (1) hepatic insulin sensitivity, (2) peripheral insulin sensitivity, and (3) substrate utilization. This was a randomized crossover study in which 14 subjects underwent 2 admissions separated by a washout period. Each admission had 2 acclimatization nights followed by 5 nights of either SR (4 hours time in bed) or normal sleep (8 hours time in bed). MAIN OUTCOME MEASURE/METHODS: Insulin sensitivity (measured by hyperinsulinemic-euglycemic clamp) and hepatic insulin sensitivity (measured by stable isotope techniques) were measured. In addition, we assayed stress hormone (24-hour urine free cortisol, metanephrine, and normetanephrine), nonesterified fatty acid (NEFA), and β-hydroxybutyrate (β-OH butyrate) levels. Resting energy expenditure (REE) and respiratory quotient (RQ) were measured by indirect calorimetry. Compared to normal sleep, whole-body insulin sensitivity decreased by 25% (P = .008) with SR and peripheral insulin sensitivity decreased by 29% (P = .003). Whereas hepatic insulin sensitivity (endogenous glucose production) did not change significantly, percent gluconeogenesis increased (P = .03). Stress hormones increased modestly (cortisol by 21%, P = .04; metanephrine by 8%, P = .014; normetanephrine by 18%, P = .002). Fasting NEFA and β-OH butyrate levels increased substantially (62% and 55%, respectively). REE did not change (P = 0.98), but RQ decreased (0.81 ± .02 vs 0.75 ± 0.02, P = .045). Subchronic SR causes unique metabolic disturbances characterized by peripheral, but not hepatic, insulin resistance; this was associated with a robust increase in fasting NEFA levels (indicative of increased lipolysis), decreased RQ, and increased β-OH butyrate levels (indicative of whole-body and hepatic fat oxidation, respectively). We postulate that elevated NEFA levels are partially responsible for the decrease in peripheral sensitivity and modulation of hepatic metabolism (ie, increase in gluconeogenesis without increase in endogenous glucose production). Elevated cortisol and metanephrine levels may contribute to insulin resistance by increasing lipolysis and NEFA levels.

Why Hasn't Earth Warmed as Much as Expected?

NASA Technical Reports Server (NTRS)

Schwartz, Stephen E.; Charlson, Robert J.; Kahn, Ralph A.; Ogren, John A.; Rodhe, Henning

2010-01-01

The observed increase in global mean surface temperature (GMST) over the industrial era is less than 40% of that expected from observed increases in long-lived greenhouse gases together with the best-estimate equilibrium climate sensitivity given by the 2007 Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). Possible reasons for this warming discrepancy are systematically examined here. The warming discrepancy is found to be due mainly to some combination of two factors: the IPCC best estimate of climate sensitivity being too high and/or the greenhouse gas forcing being partially offset by forcing by increased concentrations of atmospheric aerosols; the increase in global heat content due to thermal disequilibrium accounts for less than 25% of the discrepancy, and cooling by natural temperature variation can account for only about 15 %. Current uncertainty in climate sensitivity is shown to preclude determining the amount of future fossil fuel CO2 emissions that would be compatible with any chosen maximum allowable increase in GMST; even the sign of such allowable future emissions is unconstrained. Resolving this situation, by empirical determination of the earth's climate sensitivity from the historical record over the industrial period or through use of climate models whose accuracy is evaluated by their performance over this period, is shown to require substantial reduction in the uncertainty of aerosol forcing over this period.

Dyes designed for high sensitivity detection of double-stranded DNA

DOEpatents

Glazer, Alexander N.; Benson, Scott C.

2000-01-01

Novel fluorescent dyes are provided, characterized by having a fluorophore joined to a cationic chain. The dyes are found to provide for high enhancement upon binding to nucleic acid and have strong binding affinities to the nucleic acid, as compared to the fluorophore without the polycationic chain. The dyes find use in detection of dsDNA in gel electrophoresis and solution at substantially higher sensitivities using substantially less dye.

Dyes designed for high sensitivity detection of double-stranded DNA

DOEpatents

Glazer, Alexander N.; Benson, Scott C.

1998-01-01

Novel fluorescent dyes are provided, characterized by having a fluorophore joined to a cationic chain. The dyes are found to provide for high enhancement upon binding to nucleic acid and have strong binding affinities to the nucleic acid, as compared to the fluorophore without the polycationic chain. The dyes find use in detection of dsDNA in gel electrophoresis and solution at substantially higher sensitivities using substantially less dye.

Estimation of the notch sensitivity of a nitrided steel by acoustic emission

NASA Astrophysics Data System (ADS)

Rogachev, S. O.; Nikulin, S. A.; Khatkevich, V. M.; Ozherelkov, D. Yu.; Molyarov, A. V.

2017-10-01

The notch sensitivity of sheet corrosion-resistant 08Kh17T steel is estimated in the states before and after high-temperature (1000-1100°C) internal nitriding during tensile tests accompanied by the measurement of acoustic emission signals. A crack in the steel is shown to propagate according to a ductile mechanism is all states. As the nitrogen content increases from 0.60 to 0.85%, the ultimate tensile strength of the steel decreases by 15% in the presence of a stress concentrator and remains substantially higher than the yield strength of the sheet steel without a stress concentrator.

Online and offline tools for head movement compensation in MEG.

PubMed

Stolk, Arjen; Todorovic, Ana; Schoffelen, Jan-Mathijs; Oostenveld, Robert

2013-03-01

Magnetoencephalography (MEG) is measured above the head, which makes it sensitive to variations of the head position with respect to the sensors. Head movements blur the topography of the neuronal sources of the MEG signal, increase localization errors, and reduce statistical sensitivity. Here we describe two novel and readily applicable methods that compensate for the detrimental effects of head motion on the statistical sensitivity of MEG experiments. First, we introduce an online procedure that continuously monitors head position. Second, we describe an offline analysis method that takes into account the head position time-series. We quantify the performance of these methods in the context of three different experimental settings, involving somatosensory, visual and auditory stimuli, assessing both individual and group-level statistics. The online head localization procedure allowed for optimal repositioning of the subjects over multiple sessions, resulting in a 28% reduction of the variance in dipole position and an improvement of up to 15% in statistical sensitivity. Offline incorporation of the head position time-series into the general linear model resulted in improvements of group-level statistical sensitivity between 15% and 29%. These tools can substantially reduce the influence of head movement within and between sessions, increasing the sensitivity of many cognitive neuroscience experiments. Copyright © 2012 Elsevier Inc. All rights reserved.

Sensitivity to binaural timing in bilateral cochlear implant users.

PubMed

van Hoesel, Richard J M

2007-04-01

Various measures of binaural timing sensitivity were made in three bilateral cochlear implant users, who had demonstrated moderate-to-good interaural time delay (ITD) sensitivity at 100 pulses-per-second (pps). Overall, ITD thresholds increased at higher pulse rates, lower levels, and shorter durations, although intersubject differences were evident. Monaural rate-discrimination thresholds, using the same stimulation parameters, showed more substantial elevation than ITDs with increased rate. ITD sensitivity with 6000 pps stimuli, amplitude-modulated at 100 Hz, was similar to that with unmodulated pulse trains at 100 pps, but at 200 and 300 Hz performance was poorer than with unmodulated signals. Measures of sensitivity to binaural beats with unmodulated pulse-trains showed that all three subjects could use time-varying ITD cues at 100 pps, but not 300 pps, even though static ITD sensitivity was relatively unaffected over that range. The difference between static and dynamic ITD thresholds is discussed in terms of relative contributions from initial and later arriving cues, which was further examined in an experiment using two-pulse stimuli as a function of interpulse separation. In agreement with the binaural-beat data, findings from that experiment showed poor discrimination of ITDs on the second pulse when the interval between pulses was reduced to a few milliseconds.

Payments, promotion, and the purple pill.

PubMed

Ridley, David B

2015-01-01

Understanding competition in the US drug market requires knowing how sensitive demand is to prices. The relevant prices for insured consumers are copayments. There are many studies of copayment elasticity in the health literature, but they are of limited applicability for studies of competition. Because of a paucity of data, such studies typically control for neither competitor copayment nor advertising. Whereas previous studies examined copayment sensitivity when copayments for branded drugs move in unison, this study examines copayment sensitivity when copayments diverge. This study uses unique panel data of insurance copayments and utilization for 77 insurance groups, as well as data on advertising. The results indicate that demand can be much more sensitive to copayment than previously recognized. Manufacturers selling drugs with higher copayments than branded competitors can lose substantial market share. Manufacturers can offset the loss of demand by increasing advertising to physicians, but it is costly. Copyright © 2013 John Wiley & Sons, Ltd.

Nano-machining of biosensor electrodes through gold nanoparticles deposition produced by femtosecond laser ablation

NASA Astrophysics Data System (ADS)

Della Ventura, B.; Funari, R.; Anoop, K. K.; Amoruso, S.; Ausanio, G.; Gesuele, F.; Velotta, R.; Altucci, C.

2015-06-01

We report an application of femtosecond laser ablation to improve the sensitivity of biosensors based on a quartz crystal microbalance device. The nanoparticles produced by irradiating a gold target with 527-nm, 300-fs laser pulses, in high vacuum, are directly deposited on the quartz crystal microbalance electrode. Different gold electrodes are fabricated by varying the deposition time, thus addressing how the nanoparticles surface coverage influences the sensor response. The modified biosensor is tested by weighting immobilized IgG antibody from goat and its analyte (IgG from mouse), and the results are compared with a standard electrode. A substantial increase of biosensor sensitivity is achieved, thus demonstrating that femtosecond laser ablation and deposition is a viable physical method to improve the biosensor sensitivity by means of nanostructured electrodes.

Space station integrated propulsion and fluid systems study

NASA Technical Reports Server (NTRS)

Bicknell, B.; Wilson, S.; Dennis, M.; Shepard, D.; Rossier, R.

1988-01-01

The program study was performed in two tasks: Task 1 addressed propulsion systems and Task 2 addressed all fluid systems associated with the Space Station elements, which also included propulsion and pressurant systems. Program results indicated a substantial reduction in life cycle costs through integrating the oxygen/hydrogen propulsion system with the environmental control and life support system, and through supplying nitrogen in a cryogenic gaseous supercritical or subcritical liquid state. A water sensitivity analysis showed that increasing the food water content would substantially increase the amount of water available for propulsion use and in all cases, the implementation of the BOSCH CO2 reduction process would reduce overall life cycle costs to the station and minimize risk. An investigation of fluid systems and associated requirements revealed a delicate balance between the individual propulsion and fluid systems across work packages and a strong interdependence between all other fluid systems.

Method for rapid isolation of sensitive mutants

DOEpatents

Freyer, James P.

1997-01-01

Sensitive mammalian cell mutants are rapidly isolated using flow cytometry. A first population of clonal spheroids is established to contain both normal and mutant cells. The population may be naturally occurring or may arise from mutagenized cells. The first population is then flow sorted by size to obtain a second population of clonal spheroids of a first uniform size. The second population is then exposed to a DNA-damaging agent that is being investigated. The exposed second population is placed in a growth medium to form a third population of clonal spheroids comprising spheroids of increased size from the mammalian cells that are resistant to the DNA-damaging agent and spheroids of substantially the first uniform size formed from the mammalian cells that are sensitive to the DNA-damaging agent. The third population is not flow sorted to differentiate the spheroids formed from resistant mammalian cells from spheroids formed from sensitive mammalian cells. The spheroids formed from sensitive mammalian cells are now treated to recover viable sensitive cells from which a sensitive cell line can be cloned.

Method for rapid isolation of sensitive mutants

DOEpatents

Freyer, J.P.

1997-07-29

Sensitive mammalian cell mutants are rapidly isolated using flow cytometry. A first population of clonal spheroids is established to contain both normal and mutant cells. The population may be naturally occurring or may arise from mutagenized cells. The first population is then flow sorted by size to obtain a second population of clonal spheroids of a first uniform size. The second population is then exposed to a DNA-damaging agent that is being investigated. The exposed second population is placed in a growth medium to form a third population of clonal spheroids comprising spheroids of increased size from the mammalian cells that are resistant to the DNA-damaging agent and spheroids of substantially the first uniform size formed from the mammalian cells that are sensitive to the DNA-damaging agent. The third population is not flow sorted to differentiate the spheroids formed from resistant mammalian cells from spheroids formed from sensitive mammalian cells. The spheroids formed from sensitive mammalian cells are now treated to recover viable sensitive cells from which a sensitive cell line can be cloned. 15 figs.

Sensitivity and bias under conditions of equal and unequal academic task difficulty.

PubMed

Reed, Derek D; Martens, Brian K

2008-01-01

We conducted an experimental analysis of children's relative problem-completion rates across two workstations under conditions of equal (Experiment 1) and unequal (Experiment 2) problem difficulty. Results were described using the generalized matching equation and were evaluated for degree of schedule versus stimulus control. Experiment 1 involved a symmetrical choice arrangement in which the children could earn points exchangeable for rewards contingent on correct math problem completion. Points were delivered according to signaled variable-interval schedules at each workstation. For 2 children, relative rates of problem completion appeared to have been controlled by the schedule requirements in effect and matched relative rates of reinforcement, with sensitivity values near 1 and bias values near 0. Experiment 2 involved increasing the difficulty of math problems at one of the workstations. Sensitivity values for all 3 participants were near 1, but a substantial increase in bias toward the easier math problems was observed. This bias was possibly associated with responding at the more difficult workstation coming under stimulus control rather than schedule control.

Synthesis and spectral characterization of environmentally responsive fluorescent deoxycytidine analogs

PubMed Central

Elmehriki, Adam AH; Suchý, Mojmír; Chicas, Kirby J; Wojciechowski, Filip; Hudson, Robert HE

2014-01-01

Herein, we describe the synthesis and spectroscopic properties of five novel pyrrolodeoxycytidine analogs, and the related 5-(1-pyrenylethynyl)-2’-deoxycytidine analog; as well as fluorescence characterization of 5-(p-methoxyphenylethynyl)-2’-deoxyuridine. Within this series of compounds, rigidification of the structure from 6-phenylpyrrolodeoxycytidine to 5,6-benzopyrroldeoxycytidine made remarkable improvement of the fluorescence quantum yield (Φ ~1, EtOH) and substantially increased the Stokes shift. Exchange of the phenyl group of 6-phenylpyrrolodeoxycytidine for other heterocycles (benzofuryl or indolyl) produced an increase in the extinction coefficient at the excitation wavelength while preserving high quantum yields. The steady-state fluorescence response to the environment was determined by sensitivity of Stokes shift to solvent polarity. The effect of solvent polarity on fluorescence emission intensity was concurrently examined and showed that 5,6-benzopyrrolodeoxycytidine is highly sensitive to the presence of water. On the other hand, the previously synthesized 5-(p-methoxyphenylethynyl)-2’-deoxyuridine was found to be sensitive to solvent viscosity indicating molecular rotor behavior. PMID:25483932

Climate change amplifies the interactions between wind and bark beetle disturbances in forest landscapes.

PubMed

Seidl, Rupert; Rammer, Werner

2017-07-01

Growing evidence suggests that climate change could substantially alter forest disturbances. Interactions between individual disturbance agents are a major component of disturbance regimes, yet how interactions contribute to their climate sensitivity remains largely unknown. Here, our aim was to assess the climate sensitivity of disturbance interactions, focusing on wind and bark beetle disturbances. We developed a process-based model of bark beetle disturbance, integrated into the dynamic forest landscape model iLand (already including a detailed model of wind disturbance). We evaluated the integrated model against observations from three wind events and a subsequent bark beetle outbreak, affecting 530.2 ha (3.8 %) of a mountain forest landscape in Austria between 2007 and 2014. Subsequently, we conducted a factorial experiment determining the effect of changes in climate variables on the area disturbed by wind and bark beetles separately and in combination. iLand was well able to reproduce observations with regard to area, temporal sequence, and spatial pattern of disturbance. The observed disturbance dynamics was strongly driven by interactions, with 64.3 % of the area disturbed attributed to interaction effects. A +4 °C warming increased the disturbed area by +264.7 % and the area-weighted mean patch size by +1794.3 %. Interactions were found to have a ten times higher sensitivity to temperature changes than main effects, considerably amplifying the climate sensitivity of the disturbance regime. Disturbance interactions are a key component of the forest disturbance regime. Neglecting interaction effects can lead to a substantial underestimation of the climate change sensitivity of disturbance regimes.

Climate Sensitivity, Sea Level, and Atmospheric Carbon Dioxide

NASA Technical Reports Server (NTRS)

Hansen, James; Sato, Makiko; Russell, Gary; Kharecha, Pushker

2013-01-01

Cenozoic temperature, sea level and CO2 covariations provide insights into climate sensitivity to external forcings and sea-level sensitivity to climate change. Climate sensitivity depends on the initial climate state, but potentially can be accurately inferred from precise palaeoclimate data. Pleistocene climate oscillations yield a fast-feedback climate sensitivity of 3+/-1deg C for a 4 W/sq m CO2 forcing if Holocene warming relative to the Last Glacial Maximum (LGM) is used as calibration, but the error (uncertainty) is substantial and partly subjective because of poorly defined LGM global temperature and possible human influences in the Holocene. Glacial-to-interglacial climate change leading to the prior (Eemian) interglacial is less ambiguous and implies a sensitivity in the upper part of the above range, i.e. 3-4deg C for a 4 W/sq m CO2 forcing. Slow feedbacks, especially change of ice sheet size and atmospheric CO2, amplify the total Earth system sensitivity by an amount that depends on the time scale considered. Ice sheet response time is poorly defined, but we show that the slow response and hysteresis in prevailing ice sheet models are exaggerated. We use a global model, simplified to essential processes, to investigate state dependence of climate sensitivity, finding an increased sensitivity towards warmer climates, as low cloud cover is diminished and increased water vapour elevates the tropopause. Burning all fossil fuels, we conclude, would make most of the planet uninhabitable by humans, thus calling into question strategies that emphasize adaptation to climate change.

Enhanced leptin sensitivity and improved glucose homeostasis in mice lacking suppressor of cytokine signaling-3 in POMC-expressing cells.

PubMed

Kievit, Paul; Howard, Jane K; Badman, Michael K; Balthasar, Nina; Coppari, Roberto; Mori, Hiroyuki; Lee, Charlotte E; Elmquist, Joel K; Yoshimura, Akihiko; Flier, Jeffrey S

2006-08-01

Suppressor of cytokine signaling-3 (Socs-3) negatively regulates the action of various cytokines, as well as the metabolic hormones leptin and insulin. Mice with haploinsufficiency of Socs-3, or those with neuronal deletion of Socs-3, are lean and more leptin and insulin sensitive. To examine the role of Socs-3 within specific neurons critical to energy balance, we created mice with selective deletion of Socs-3 within pro-opiomelanocortin (POMC)-expressing cells. These mice had enhanced leptin sensitivity, measured by weight loss and food intake after leptin infusion. On chow diet, glucose homeostasis was improved despite normal weight gain. On a high-fat diet, the rate of weight gain was reduced, due to increased energy expenditure rather than decreased food intake; glucose homeostasis and insulin sensitivity were substantially improved. These studies demonstrate that Socs-3 within POMC neurons regulates leptin sensitivity and glucose homeostasis, and plays a key role in linking high-fat diet to disordered metabolism.

Increased sensitivity of prolonged P-wave during exercise stress test in detection of angiographically documented coronary artery disease.

PubMed

Wsol, Agnieszka; Wydra, Wioletta; Chmielewski, Marek; Swiatowiec, Andrzej; Kuch, Marek

2017-01-01

A retrospective study was designed to investigate P-wave duration changes in exercise stress test (EST) for the prediction of angiographically documented substantial coronary artery disease (CAD). We analyzed 265 cases of patients, who underwent EST and subsequently coronary angiography. Analysis of P-wave duration was performed in leads II, V5 at rest, and in the recovery period. The sensitivity and specificity for the isolated ST-segment depression were only 31% and 76%, respectively. The combination of ST-depression with other exercise-induced clinical and electrocardio-graphic abnormalities (chest pain, ventricular arrhythmia, hypotension, left bundle branch block) was characterized by 41% sensitivity and 69% specificity. The combination of abnormal recovery P-wave duration (≥ 120 ms) with ST-depression and other exercise-induced abnormalities had 83% sensitivity but only 20% specificity. Combined analysis of increased delta P-wave duration, ST-depression and other exercise-induced abnormalities had 69% sensitivity and 42% specificity. Sensitivity and specificity of the increase in delta P-wave duration for left CAD was 69% and 47%, respectively, and for 3-vessel CAD 70% and 50%, respectively. The presence of arterial hypertension negatively influenced the prog-nostic value of P-wave changes in the stress test. The results of the study show that an addition of P-wave duration changes assessment to ST-depression analysis and other exercise-induced abnormalities increase sensitivity of EST, especially for left CAD and 3-vessel coronary disease. We have also provided evidence for the negative influence of the presence of arterial hypertension on the predictive value of P-wave changes in the stress test. (Cardiol J 2017; 24, 2: 159-166).

Dyes designed for high sensitivity detection of double-stranded DNA

DOEpatents

Glazer, A.N.; Benson, S.C.

1998-07-21

Novel fluorescent dyes are provided, characterized by having a fluorophore joined to a cationic chain. The dyes are found to provide for high enhancement upon binding to nucleic acid and have strong binding affinities to the nucleic acid, as compared to the fluorophore without the polycationic chain. The dyes find use in detection of dsDNA in gel electrophoresis and solution at substantially higher sensitivities using substantially less dye. 10 figs.

Climate effects of a hypothetical regional nuclear war: Sensitivity to emission duration and particle composition

NASA Astrophysics Data System (ADS)

Pausata, Francesco S. R.; Lindvall, Jenny; Ekman, Annica M. L.; Svensson, Gunilla

2016-11-01

Here, we use a coupled atmospheric-ocean-aerosol model to investigate the plume development and climate effects of the smoke generated by fires following a regional nuclear war between emerging third-world nuclear powers. We simulate a standard scenario where 5 Tg of black carbon (BC) is emitted over 1 day in the upper troposphere-lower stratosphere. However, it is likely that the emissions from the fires ignited by bomb detonations include a substantial amount of particulate organic matter (POM) and that they last more than 1 day. We therefore test the sensitivity of the aerosol plume and climate system to the BC/POM ratio (1:3, 1:9) and to the emission length (1 day, 1 week, 1 month). We find that in general, an emission length of 1 month substantially reduces the cooling compared to the 1-day case, whereas taking into account POM emissions notably increases the cooling and the reduction of precipitation associated with the nuclear war during the first year following the detonation. Accounting for POM emissions increases the particle size in the short-emission-length scenarios (1 day/1 week), reducing the residence time of the injected particle. While the initial cooling is more intense when including POM emission, the long-lasting effects, while still large, may be less extreme compared to the BC-only case. Our study highlights that the emission altitude reached by the plume is sensitive to both the particle type emitted by the fires and the emission duration. Consequently, the climate effects of a nuclear war are strongly dependent on these parameters.

Improving LHC searches for dark photons using lepton-jet substructure

NASA Astrophysics Data System (ADS)

Barello, G.; Chang, Spencer; Newby, Christopher A.; Ostdiek, Bryan

2017-03-01

Collider signals of dark photons are an exciting probe for new gauge forces and are characterized by events with boosted lepton jets. Existing techniques are efficient in searching for muonic lepton jets but due to substantial backgrounds have difficulty constraining lepton jets containing only electrons. This is unfortunate since upcoming intensity frontier experiments are sensitive to dark photon masses which only allow electron decays. Analyzing a recently proposed model of kinetic mixing, with new scalar particles decaying into dark photons, we find that existing techniques for electron jets can be substantially improved. We show that using lepton-jet-substructure variables, in association with a boosted decision tree, improves background rejection, significantly increasing the LHC's reach for dark photons in this region of parameter space.

Breakthrough Capability for UVOIR Space Astronomy: Reaching the Darkest Sky

NASA Technical Reports Server (NTRS)

Greenhouse, Matthew A.; Benson, Scott W.; Englander, Jacob; Falck, Robert D.; Fixsen, Dale J.; Gardner, Jonathan P.; Kruk, Jeffrey W.; Oleson, Steven R.; Thronson, Harley A.

2014-01-01

We describe how availability of new solar electric propulsion (SEP) technology can substantially increase the science capability of space astronomy missions working within the near-UV to far-infrared (UVOIR) spectrum by making dark sky orbits accessible for the first time. We present a proof of concept case study in which SEP is used to enable a 700 kg Explorer-class observatory payload to reach an orbit beyond where the zodiacal dust limits observatory sensitivity. The resulting scientific performance advantage relative to a Sun-Earth L2 point orbit is presented and discussed. We find that making SEP available to astrophysics Explorers can enable this small payload program to rival the science performance of much larger long development-time systems. We also present flight dynamics analysis which illustrates that this concept can be extended beyond Explorers to substantially improve the sensitivity performance of heavier (7000 kg) flagship-class astrophysics payloads such as the UVOIR successor to the James Webb Space Telescope by using high power SEP that is being developed for the Asteroid Redirect Robotics Mission.

Visualization under ultraviolet light enhances 100-fold the sensitivity of peroxidase-stained blots.

PubMed

Domingo, A; Marco, R

1989-10-01

As described in this article, visualization and/or photography under uv light of 4-chloro-1-naphthol-developed, peroxidase-marked immunoblots allows an increase in sensitivity of more than 100 times over the apparent staining results observable under normal visible white light. This increase in sensitivity can be obtained with the minimal additional requirement of an uv lamp, with the actual chloronaphthol staining procedure remaining unaltered and thereby allowing the monitoring of specific reactions with much smaller quantities of antigen or antibodies. Substantial shortening of the procedure is another advantage, making it possible to complete in 20 min or even less a procedure usually requiring 3 to 6 h. The phenomenon depends on the uv absorption and the fluorescence quenching properties of the products of the peroxidase reaction. The absorption spectra of the membranes with or without peroxidase products indicate that an intermediate in the peroxidase reaction is responsible for the absorption under uv light. This intermediate accumulates under conditions where the final product absorbing in the visible light has not begun to be produced, thus explaining the large increase in sensitivity. The behaviors of three types of membranes, nitrocellulose, nylon, and Immobilon (PVDF), are compared. Due to its lower uv absorption, PVDF gives by far the best results, followed by nitrocellulose.

Goddard X-ray astronomy contributions to the IAU/COSPAR (1982)

NASA Technical Reports Server (NTRS)

Holt, S. S.; Petre, R.; Shafer, R. A.; Urry, C. M.; Mushotzky, R. F.

1982-01-01

The relation of X-ray flux to both the continuum flux in the optical and radio bands, and to the line emission properties of these objects were studied. The Einstein Observatory, because of increased sensitivity and improved angular resolution, increased substantially the number of known X-ray emitting active galactic nuclei. The Einstein imaging instruments detected morphology in AGN X-ray emission, in particular from jetlike structures in Cen-A, M87, and 3C273. The improved energy resolution and sensitivity of the spectrometers onboard the Observatory provide information on the geometry and ionization structure of the region responsible for the broad optical emission lines in a few AGN's. This information, combined with theoretical modeling and IUE and optical observations, allows the construction of a moderately detailed picture of the broad line region in these objects.

Dyes designed for high sensitivity detection of double-stranded DNA

DOEpatents

Glazer, Alexander N.; Benson, Scott C.

1994-01-01

Novel fluorescent dyes are provided, characterized by having a fluorophore joined to a polycationic chain of at least two positive charges. The dyes are found to provide for high enhancement upon binding to nucleic acid and have strong binding affinities to the nucleic acid, as compared to the fluorophore without the polycationic chain. The dyes find use in detection of dsDNA in gel electrophoresis and solution at substantially higher sensitivities using substantially less dye.

Emissions pathways, climate change, and impacts on California

USGS Publications Warehouse

Hayhoe, K.; Cayan, D.; Field, C.B.; Frumhoff, P.C.; Maurer, E.P.; Miller, N.L.; Moser, S.C.; Schneider, S.H.; Cahill, K.N.; Cleland, E.E.; Dale, L.; Drapek, R.; Hanemann, R.M.; Kalkstein, L.S.; Lenihan, J.; Lunch, C.K.; Neilson, R.P.; Sheridan, S.C.; Verville, J.H.

2004-01-01

The magnitude of future climate change depends substantially on the greenhouse gas emission pathways we choose. Here we explore the implications of the highest and lowest Intergovernmental Panel on Climate Change emissions pathways for climate change and associated impacts in California. Based on climate projections from two state-of-the-art climate models with low and medium sensitivity (Parallel Climate Model and Hadley Centre Climate Model, version 3, respectively), we find that annual temperature increases nearly double from the lower B1 to the higher A1fi emissions scenario before 2100. Three of four simulations also show greater increases in summer temperatures as compared with winter. Extreme heat and the associated impacts on a range of temperature-sensitive sectors are substantially greater under the higher emissions scenario, with some interscenario differences apparent before midcentury. By the end of the century under the B1 scenario, heatwaves and extreme heat in Los Angeles quadruple in frequency while heat-related mortality increases two to three times; alpine/subalpine forests are reduced by 50-75%; and Sierra snowpack is reduced 30-70%. Under A1fi, heatwaves in Los Angeles are six to eight times more frequent, with heat-related excess mortality increasing five to seven times; alpine/subalpine forests are reduced by 75-90%; and snowpack declines 73-90%, with cascading impacts on runoff and streamflow that, combined with projected modest declines in winter precipitation, could fundamentally disrupt California's water rights system. Although interscenario differences in climate impacts and costs of adaptation emerge mainly in the second half of the century, they are strongly dependent on emissions from preceding decades.

Optical temperature compensation schemes of spectral modulation sensors for aircraft engine control

NASA Astrophysics Data System (ADS)

Berkcan, Ertugrul

1993-02-01

Optical temperature compensation schemes for the ratiometric interrogation of spectral modulation sensors for source temperature robustness are presented. We have obtained better than 50 - 100X decrease of the temperature coefficient of the sensitivity using these types of compensation. We have also developed a spectrographic interrogation scheme that provides increased source temperature robustness; this affords a significantly improved accuracy over FADEC temperature ranges as well as temperature coefficient of the sensitivity that is substantially and further reduced. This latter compensation scheme can be integrated in a small E/O package including the detection, analog and digital signal processing. We find that these interrogation schemes can be used within a detector spatially multiplexed architecture.

No effects of hydrocortisone and dexamethasone on pain sensitivity in healthy individuals.

PubMed

Wingenfeld, K; Wolf, S; Kunz, M; Krieg, J-C; Lautenbacher, S

2015-07-01

There is some evidence that stress-induced cortisol increase leads to a decrease in pain, while lowering cortisol levels enhances pain sensitivity, but no study has yet investigated both pharmacological enhancement and reduction of cortisol levels in the same individuals. Firstly, we tested in 16 healthy individuals whether the treatment with hydrocortisone and dexamethasone, respectively, results in altered pain thresholds. Secondly, we aimed to test whether hormone effects are different across the pain range by using ratings for pain stimuli with varying intensity; and thirdly, we tested whether cortisol levels influence the discrimination ability for painful stimuli. Despite substantial effects of dexamethasone and hydrocortisone administration on cortisol levels, no effect of these drugs was seen in terms of pain sensitivity (pain threshold, pain rating, pain discrimination ability), although comprehensively examined. However, in the placebo condition, a significant negative correlation between cortisol and pain thresholds was seen. Similarly, there were also strong negative associations between cortisol levels in the placebo condition and pain thresholds after drug treatment (especially after hydrocortisone). These findings suggest that short-term variations of cortisol do not influence pain sensitivity whereas, in general, high levels of cortisol are associated with increased pain sensitivity, at least for weak to moderate stimuli. © 2014 European Pain Federation - EFIC®

Sub-wavelength efficient polarization filter (SWEP filter)

DOEpatents

Simpson, Marcus L.; Simpson, John T.

2003-12-09

A polarization sensitive filter includes a first sub-wavelength resonant grating structure (SWS) for receiving incident light, and a second SWS. The SWS are disposed relative to one another such that incident light which is transmitted by the first SWS passes through the second SWS. The filter has a polarization sensitive resonance, the polarization sensitive resonance substantially reflecting a first polarization component of incident light while substantially transmitting a second polarization component of the incident light, the polarization components being orthogonal to one another. A method for forming polarization filters includes the steps of forming first and second SWS, the first and second SWS disposed relative to one another such that a portion of incident light applied to the first SWS passes through the second SWS. A method for separating polarizations of light, includes the steps of providing a filter formed from a first and second SWS, shining incident light having orthogonal polarization components on the first SWS, and substantially reflecting one of the orthogonal polarization components while substantially transmitting the other orthogonal polarization component. A high Q narrowband filter includes a first and second SWS, the first and second SWS are spaced apart a distance being at least one half an optical wavelength.

Development of short-form measures to assess four types of elder mistreatment: Findings from an evidence-based study of APS elder abuse substantiation decisions.

PubMed

Beach, Scott R; Liu, Pi-Ju; DeLiema, Marguerite; Iris, Madelyn; Howe, Melissa J K; Conrad, Kendon J

2017-01-01

Improving the standardization and efficiency of adult protective services (APS) investigations is a top priority in APS practice. Using data from the Elder Abuse Decision Support System (EADSS), we developed short-form measures of four types of elder abuse: financial, emotional/psychological, physical, and neglect. The EADSS data set contains 948 elder abuse cases (age 60+) with yes/no abuse substantiation decisions for each abuse type following a 30-day investigation. Item sensitivity/specificity analyses were conducted on long-form items with the substantiation decision for each abuse type as the criterion. Validity was further tested using receiver-operator characteristic (ROC) curve analysis, correlation with long forms and internal consistency. The four resulting short-form measures, containing 36 of the 82 original items, have validity similar to the original long forms. These short forms can be used to standardize and increase efficiency of APS investigations, and may also offer researchers new options for brief elder abuse assessments.

Development of short-form measures to assess four types of elder mistreatment: Findings from an evidence-based study of APS elder abuse substantiation decisions

PubMed Central

Beach, Scott R.; Liu, Pi-Ju; DeLiema, Marguerite; Iris, Madelyn; Howe, Melissa J.K.; Conrad, Kendon J.

2018-01-01

Improving the standardization and efficiency of adult protective services (APS) investigations is a top priority in APS practice. Using data from the Elder Abuse Decision Support System (EADSS), we developed short-form measures of four types of elder abuse: financial, emotional/psychological, physical, and neglect. The EADSS data set contains 948 elder abuse cases (age 60+) with yes/no abuse substantiation decisions for each abuse type following a 30-day investigation. Item sensitivity/specificity analyses were conducted on long-form items with the substantiation decision for each abuse type as the criterion. Validity was further tested using receiver–operator characteristic (ROC) curve analysis, correlation with long forms and internal consistency. The four resulting short-form measures, containing 36 of the 82 original items, have validity similar to the original long forms. These short forms can be used to standardize and increase efficiency of APS investigations, and may also offer researchers new options for brief elder abuse assessments. PMID:28590799

Climate sensitivity, sea level and atmospheric carbon dioxide

PubMed Central

Hansen, James; Sato, Makiko; Russell, Gary; Kharecha, Pushker

2013-01-01

Cenozoic temperature, sea level and CO2 covariations provide insights into climate sensitivity to external forcings and sea-level sensitivity to climate change. Climate sensitivity depends on the initial climate state, but potentially can be accurately inferred from precise palaeoclimate data. Pleistocene climate oscillations yield a fast-feedback climate sensitivity of 3±1°C for a 4 W m−2 CO2 forcing if Holocene warming relative to the Last Glacial Maximum (LGM) is used as calibration, but the error (uncertainty) is substantial and partly subjective because of poorly defined LGM global temperature and possible human influences in the Holocene. Glacial-to-interglacial climate change leading to the prior (Eemian) interglacial is less ambiguous and implies a sensitivity in the upper part of the above range, i.e. 3–4°C for a 4 W m−2 CO2 forcing. Slow feedbacks, especially change of ice sheet size and atmospheric CO2, amplify the total Earth system sensitivity by an amount that depends on the time scale considered. Ice sheet response time is poorly defined, but we show that the slow response and hysteresis in prevailing ice sheet models are exaggerated. We use a global model, simplified to essential processes, to investigate state dependence of climate sensitivity, finding an increased sensitivity towards warmer climates, as low cloud cover is diminished and increased water vapour elevates the tropopause. Burning all fossil fuels, we conclude, would make most of the planet uninhabitable by humans, thus calling into question strategies that emphasize adaptation to climate change. PMID:24043864

Climate sensitivity, sea level and atmospheric carbon dioxide.

PubMed

Hansen, James; Sato, Makiko; Russell, Gary; Kharecha, Pushker

2013-10-28

Cenozoic temperature, sea level and CO2 covariations provide insights into climate sensitivity to external forcings and sea-level sensitivity to climate change. Climate sensitivity depends on the initial climate state, but potentially can be accurately inferred from precise palaeoclimate data. Pleistocene climate oscillations yield a fast-feedback climate sensitivity of 3±1(°)C for a 4 W m(-2) CO2 forcing if Holocene warming relative to the Last Glacial Maximum (LGM) is used as calibration, but the error (uncertainty) is substantial and partly subjective because of poorly defined LGM global temperature and possible human influences in the Holocene. Glacial-to-interglacial climate change leading to the prior (Eemian) interglacial is less ambiguous and implies a sensitivity in the upper part of the above range, i.e. 3-4(°)C for a 4 W m(-2) CO2 forcing. Slow feedbacks, especially change of ice sheet size and atmospheric CO2, amplify the total Earth system sensitivity by an amount that depends on the time scale considered. Ice sheet response time is poorly defined, but we show that the slow response and hysteresis in prevailing ice sheet models are exaggerated. We use a global model, simplified to essential processes, to investigate state dependence of climate sensitivity, finding an increased sensitivity towards warmer climates, as low cloud cover is diminished and increased water vapour elevates the tropopause. Burning all fossil fuels, we conclude, would make most of the planet uninhabitable by humans, thus calling into question strategies that emphasize adaptation to climate change.

Sensitivity of managed boreal forests in Finland to climate change, with implications for adaptive management.

PubMed

Kellomäki, Seppo; Peltola, Heli; Nuutinen, Tuula; Korhonen, Kari T; Strandman, Harri

2008-07-12

This study investigated the sensitivity of managed boreal forests to climate change, with consequent needs to adapt the management to climate change. Model simulations representing the Finnish territory between 60 and 70 degrees N showed that climate change may substantially change the dynamics of managed boreal forests in northern Europe. This is especially probable at the northern and southern edges of this forest zone. In the north, forest growth may increase, but the special features of northern forests may be diminished. In the south, climate change may create a suboptimal environment for Norway spruce. Dominance of Scots pine may increase on less fertile sites currently occupied by Norway spruce. Birches may compete with Scots pine even in these sites and the dominance of birches may increase. These changes may reduce the total forest growth locally but, over the whole of Finland, total forest growth may increase by 44%, with an increase of 82% in the potential cutting drain. The choice of appropriate species and reduced rotation length may sustain the productivity of forest land under climate change.

Fundamental study of flow field generated by rotorcraft blades using wide-field shadowgraph

NASA Technical Reports Server (NTRS)

Parthasarathy, S. P.; Cho, Y. I.; Back, L. H.

1985-01-01

The vortex trajectory and vortex wake generated by helicopter rotors are visualized using a wide-field shadowgraph technique. Use of a retro-reflective Scotchlite screen makes it possible to investigate the flow field generated by full-scale rotors. Tip vortex trajectories are visible in shadowgraphs for a range of tip Mach number of 0.38 to 0.60. The effect of the angle of attack is substantial. At an angle of attack greater than 8 degrees, the visibility of the vortex core is significant even at relatively low tip Mach numbers. The theoretical analysis of the sensitivity is carried out for a rotating blade. This analysis demonstrates that the sensitivity decreases with increasing dimensionless core radius and increases with increasing tip Mach number. The threshold value of the sensitivity is found to be 0.0015, below which the vortex core is not visible and above which it is visible. The effect of the optical path length is also discussed. Based on this investigation, it is concluded that the application of this wide-field shadowgraph technique to a large wind tunnel test should be feasible. In addition, two simultaneous shadowgraph views would allow three-dimensional reconstruction of vortex trajectories.

Effect of Low-Temperature Sensitization on the Corrosion Behavior of AISI Type 304L SS Weld Metal in Simulated Groundwater

NASA Astrophysics Data System (ADS)

Suresh, Girija; Nandakumar, T.; Viswanath, A.

2018-04-01

The manuscript presents the investigations carried out on the effect of low-temperature sensitization (LTS) of 304L SS weld metal on its corrosion behavior in simulated groundwater, for its application as a canister material for long-term storage of nuclear vitrified high-level waste in geological repositories. AISI type 304L SS weld pad was fabricated by multipass gas tungsten arc welding process using 308L SS filler wire. The as-welded specimens were subsequently subjected to carbide nucleation and further to LTS at 500 °C for 11 days to simulate a temperature of 300 °C for 100-year life of the canister in geological repositories. Delta ferrite (δ-ferrite) content of the 304L SS weld metal substantially decreased on carbide nucleation treatment and further only a marginal decrease occurred on LTS treatment. The microstructure of the as-welded consisted of δ-ferrite as a minor phase distributed in austenite matrix. The δ-ferrite appeared fragmented in the carbide-nucleated and LTS-treated weld metal. The degree of sensitization measured by double-loop electrochemical potentokinetic reactivation method indicated an increase in carbide nucleation treatment when compared to the as-welded specimens, and further increase occurred on LTS treatment. Potentiodynamic anodic polarization investigations in simulated groundwater indicated a substantial decrease in the localized corrosion resistance of the carbide-nucleated and LTS 304L SS weld metals, when compared to the as-welded specimens. Post-experimental micrographs indicated pitting as the primary mode of attack in the as-welded, while pitting and intergranular corrosion (IGC) occurred in the carbide-nucleated weld metal. LTS-treated weld metal predominantly underwent IGC attack. The decrease in the localized corrosion resistance of the weld metal after LTS treatment was found to have a direct correlation with the degree of sensitization and the weld microstructure. The results are detailed in the manuscript.

Effect of Low-Temperature Sensitization on the Corrosion Behavior of AISI Type 304L SS Weld Metal in Simulated Groundwater

NASA Astrophysics Data System (ADS)

Suresh, Girija; Nandakumar, T.; Viswanath, A.

2018-05-01

The manuscript presents the investigations carried out on the effect of low-temperature sensitization (LTS) of 304L SS weld metal on its corrosion behavior in simulated groundwater, for its application as a canister material for long-term storage of nuclear vitrified high-level waste in geological repositories. AISI type 304L SS weld pad was fabricated by multipass gas tungsten arc welding process using 308L SS filler wire. The as-welded specimens were subsequently subjected to carbide nucleation and further to LTS at 500 °C for 11 days to simulate a temperature of 300 °C for 100-year life of the canister in geological repositories. Delta ferrite ( δ-ferrite) content of the 304L SS weld metal substantially decreased on carbide nucleation treatment and further only a marginal decrease occurred on LTS treatment. The microstructure of the as-welded consisted of δ-ferrite as a minor phase distributed in austenite matrix. The δ-ferrite appeared fragmented in the carbide-nucleated and LTS-treated weld metal. The degree of sensitization measured by double-loop electrochemical potentokinetic reactivation method indicated an increase in carbide nucleation treatment when compared to the as-welded specimens, and further increase occurred on LTS treatment. Potentiodynamic anodic polarization investigations in simulated groundwater indicated a substantial decrease in the localized corrosion resistance of the carbide-nucleated and LTS 304L SS weld metals, when compared to the as-welded specimens. Post-experimental micrographs indicated pitting as the primary mode of attack in the as-welded, while pitting and intergranular corrosion (IGC) occurred in the carbide-nucleated weld metal. LTS-treated weld metal predominantly underwent IGC attack. The decrease in the localized corrosion resistance of the weld metal after LTS treatment was found to have a direct correlation with the degree of sensitization and the weld microstructure. The results are detailed in the manuscript.

Effects of Detector Thickness on Geometric Sensitivity and Event Positioning Errors in the Rectangular PET/X Scanner

NASA Astrophysics Data System (ADS)

MacDonald, Lawrence R.; Hunter, William C. J.; Kinahan, Paul E.; Miyaoka, Robert S.

2013-10-01

We used simulations to investigate the relationship between sensitivity and spatial resolution as a function of crystal thickness in a rectangular PET scanner intended for quantitative assessment of breast cancers. The system had two 20 × 15-cm2 and two 10 × 15-cm2 flat detectors forming a box, with the larger detectors separated by 4 or 8 cm. Depth-of-interaction (DOI) resolution was modeled as a function of crystal thickness based on prior measurements. Spatial resolution was evaluated independent of image reconstruction by deriving and validating a surrogate metric from list-mode data ( dFWHM). When increasing crystal thickness from 5 to 40 mm, and without using DOI information, the dFWHM for a centered point source increased from 0.72 to 1.6 mm. Including DOI information improved dFWHM by 12% and 27% for 5- and 40-mm-thick crystals, respectively. For a point source in the corner of the FOV, use of DOI information improved dFWHM by 20% (5-mm crystal) and 44% (40-mm crystal). Sensitivity was 7.7% for 10-mm-thick crystals (8-cm object). Increasing crystal thickness on the smaller side detectors from 10 to 20 mm (keeping 10-mm crystals on the larger detectors) boosted sensitivity by 24% (relative) and degraded dFWHM by only 3%/8% with/without DOI information. The benefits of measuring DOI must be evaluated in terms of the intended clinical task of assessing tracer uptake in small lesions. Increasing crystal thickness on the smaller side detectors provides substantial sensitivity increase with minimal accompanying loss in resolution.

Photonic Crystal Enhanced Fluorescence for Early Breast Cancer Biomarker Detection

PubMed Central

Cunningham, Brian T.; Zangar, Richard C.

2013-01-01

Photonic crystal surfaces offer a compelling platform for improving the sensitivity of surface-based fluorescent assays used in disease diagnostics. Through the complementary processes of photonic crystal enhanced excitation and enhanced extraction, a periodic dielectric-based nanostructured surface can simultaneously increase the electric field intensity experienced by surface-bound fluorophores and increase the collection efficiency of emitted fluorescent photons. Through the ability to inexpensively fabricate photonic crystal surfaces over substantial surface areas, they are amenable to single-use applications in biological sensing, such as disease biomarker detection in serum. In this review, we will describe the motivation for implementing high-sensitivity, multiplexed biomarker detection in the context of breast cancer diagnosis. We will summarize recent efforts to improve the detection limits of such assays though the use of photonic crystal surfaces. Reduction of detection limits is driven by low autofluorescent substrates for photonic crystal fabrication, and detection instruments that take advantage of their unique features. PMID:22736539

Warping Armchair Graphene Nanoribbon Curvature Effect on Sensing Properties: A Computational Study

NASA Astrophysics Data System (ADS)

Sakina, S. H.; Johari, Zaharah; Auzar, Zuriana; Alias, N. Ezaila; Mohamad, Azam; Zakaria, N. Aini

2018-02-01

The aim of this paper is to investigate the interaction between gas molecules and warped armchair graphene nanoribbons (AGNRs) using Extended-Huckel Theory. There are two types of warping known as inward and upward. The sensing properties including binding energy, charge transfer and sensitivity were examined for both warped AGNR cases for 3m+1 configuration and were compared with previous work. Through simulation, it was found that a substantial increase in binding energy by more than 50% was achieved when warped at a higher angle. It is also showed that there was a significant difference in sensitivity for both warping cases when reacting with O2 and NH3 molecules. Interestingly, the ability of the inward warped in sensing O2 and NH3 considerably increases upon warping angle. By applying back gate bias, this shows that current conductivity of the inward warped is twice as high as the upward warped AGNR.

Reward and punishment sensitivity and alcohol use: the moderating role of executive control.

PubMed

Jonker, Nienke C; Ostafin, Brian D; Glashouwer, Klaske A; van Hemel-Ruiter, Madelon E; de Jong, Peter J

2014-05-01

Reward sensitivity and to a lesser extent punishment sensitivity have been found to explain individual differences in alcohol use. Furthermore, many studies showed that addictive behaviors are characterized by impaired self-regulatory processes, and that individual differences related to alcohol use are moderated by executive control. This is the first study that explores the potential moderating role of executive control in the relation between reward and punishment sensitivity and alcohol use. Participants were 76 university students, selected on earlier given information about their alcohol use. Half of the participants indicated to drink little alcohol and half indicated to drink substantial amounts of alcohol. As expected, correlational analyses showed a positive relationship between reward sensitivity and alcohol use and a negative relation between punishment sensitivity and alcohol use. Regression analysis confirmed that reward sensitivity was a significant independent predictor of alcohol use. Executive control moderated the relation between punishment sensitivity and alcohol use, but not the relation between reward sensitivity and alcohol use. Only in individuals with weak executive control punishment sensitivity and alcohol use were negatively related. The results suggest that for individuals with weak executive control, punishment sensitivity might be a protective factor working against substantial alcohol use. Copyright © 2013 Elsevier Ltd. All rights reserved.

Safe Glycemic Management during Closed-Loop Treatment of Type 1 Diabetes: The Role of Glucagon, Use of Multiple Sensors, and Compensation for Stress Hyperglycemia

PubMed Central

Ward, W Kenneth; Castle, Jessica R; Youssef, Joseph El

2011-01-01

Patients with type 1 diabetes mellitus (T1DM) must make frequent decisions and lifestyle adjustments in order to manage their disorder. Automated treatment would reduce the need for these self-management decisions and reduce the risk for long-term complications. Investigators in the field of closed-loop glycemic control systems are now moving from inpatient to outpatient testing of such systems. As outpatient systems are developed, the element of safety increases in importance. One such concern is the risk for hypoglycemia, due in part to the delayed onset and prolonged action duration of currently available subcutaneous insulin preparations. We found that, as compared to an insulin-only closed-loop system, a system that also delivers glucagon when needed led to substantially less hypoglycemia. Though the capability of glucagon delivery would mandate the need for a second hormone chamber, glucagon in small doses is tolerated very well. People with T1DM often develop hyperglycemia from emotional stress or medical stress. Automated closed-loop systems should be able to detect such changes in insulin sensitivity and adapt insulin delivery accordingly. We recently verified the adaptability of a model-based closed-loop system in which the gain factors that govern a proportional-integral-derivative-like system are adjusted according to frequently measured insulin sensitivity. Automated systems can be tested by physical exercise to increase glucose uptake and insulin sensitivity or by administering corticosteroids to reduce insulin sensitivity. Another source of risk in closed-loop systems is suboptimal performance of amperometric glucose sensors. Inaccuracy can result from calibration error, biofouling, and current drift. We found that concurrent use of more than one sensor typically leads to better sensor accuracy than use of a single sensor. For example, using the average of two sensors substantially reduces the proportion of large sensor errors. The use of more than two allows the use of voting algorithms, which can temporarily exclude a sensor whose signal is outlying. Elements such as the use of glucagon to minimize hypoglycemia, adaptation to changes in insulin sensitivity, and sensor redundancy will likely increase safety during outpatient use of closed-loop glycemic control systems. PMID:22226254

Nighttime dissolution in a temperate coastal ocean ecosystem increases under acidification

PubMed Central

Kwiatkowski, Lester; Gaylord, Brian; Hill, Tessa; Hosfelt, Jessica; Kroeker, Kristy J.; Nebuchina, Yana; Ninokawa, Aaron; Russell, Ann D.; Rivest, Emily B.; Sesboüé, Marine; Caldeira, Ken

2016-01-01

Anthropogenic emissions of carbon dioxide (CO2) are causing ocean acidification, lowering seawater aragonite (CaCO3) saturation state (Ωarag), with potentially substantial impacts on marine ecosystems over the 21st Century. Calcifying organisms have exhibited reduced calcification under lower saturation state conditions in aquaria. However, the in situ sensitivity of calcifying ecosystems to future ocean acidification remains unknown. Here we assess the community level sensitivity of calcification to local CO2-induced acidification caused by natural respiration in an unperturbed, biodiverse, temperate intertidal ecosystem. We find that on hourly timescales nighttime community calcification is strongly influenced by Ωarag, with greater net calcium carbonate dissolution under more acidic conditions. Daytime calcification however, is not detectably affected by Ωarag. If the short-term sensitivity of community calcification to Ωarag is representative of the long-term sensitivity to ocean acidification, nighttime dissolution in these intertidal ecosystems could more than double by 2050, with significant ecological and economic consequences. PMID:26987406

Nighttime dissolution in a temperate coastal ocean ecosystem increases under acidification.

PubMed

Kwiatkowski, Lester; Gaylord, Brian; Hill, Tessa; Hosfelt, Jessica; Kroeker, Kristy J; Nebuchina, Yana; Ninokawa, Aaron; Russell, Ann D; Rivest, Emily B; Sesboüé, Marine; Caldeira, Ken

2016-03-18

Anthropogenic emissions of carbon dioxide (CO2) are causing ocean acidification, lowering seawater aragonite (CaCO3) saturation state (Ω arag), with potentially substantial impacts on marine ecosystems over the 21(st) Century. Calcifying organisms have exhibited reduced calcification under lower saturation state conditions in aquaria. However, the in situ sensitivity of calcifying ecosystems to future ocean acidification remains unknown. Here we assess the community level sensitivity of calcification to local CO2-induced acidification caused by natural respiration in an unperturbed, biodiverse, temperate intertidal ecosystem. We find that on hourly timescales nighttime community calcification is strongly influenced by Ω arag, with greater net calcium carbonate dissolution under more acidic conditions. Daytime calcification however, is not detectably affected by Ω arag. If the short-term sensitivity of community calcification to Ω arag is representative of the long-term sensitivity to ocean acidification, nighttime dissolution in these intertidal ecosystems could more than double by 2050, with significant ecological and economic consequences.

Drought effects on US maize and soybean production: spatiotemporal patterns and historical changes

NASA Astrophysics Data System (ADS)

Zipper, Samuel C.; Qiu, Jiangxiao; Kucharik, Christopher J.

2016-09-01

Maximizing agricultural production on existing cropland is one pillar of meeting future global food security needs. To close crop yield gaps, it is critical to understand how climate extremes such as drought impact yield. Here, we use gridded, daily meteorological data and county-level annual yield data to quantify meteorological drought sensitivity of US maize and soybean production from 1958 to 2007. Meteorological drought negatively affects crop yield over most US crop-producing areas, and yield is most sensitive to short-term (1-3 month) droughts during critical development periods from July to August. While meteorological drought is associated with 13% of overall yield variability, substantial spatial variability in drought effects and sensitivity exists, with central and southeastern US becoming increasingly sensitive to drought over time. Our study illustrates fine-scale spatiotemporal patterns of drought effects, highlighting where variability in crop production is most strongly associated with drought, and suggests that management strategies that buffer against short-term water stress may be most effective at sustaining long-term crop productivity.

Implications of Changes in Households and Living Arrangements for Future Home-based Care Needs and Costs of Disabled Elders in China1

PubMed Central

Zeng, Yi; Chen, Huashuai; Wang, Zhenglian; Land, Kenneth C.

2016-01-01

Objectives Understand future home-based care needs/costs for disabled elders in China. Method Further develop/apply ProFamy extended cohort-component method. Results (1) Chinese disabled elders and percentage of national GDP devoted to home-based care costs for disabled elders will increase much quicker than growth of total elderly population; (2) Home-based care needs/costs for disabled oldest-old aged 80+ will increase much faster than that for disabled young-old aged 65–79 after 2030; (3) Disabled unmarried elders living alone and their home-based care costs increase substantially faster than disabled unmarried elders living with children; (4) Sensitivity analyses shown that possible changes in mortality and elderly disability status are the major factors affecting home-based care needs and costs; (5) Caregivers resources under two-child policy will be substantially better than under current fertility policy unchanged. Discussion Policy recommendations concerning reductions of prevalence of disability, gender equality, two-child policy, encouraging elder’s residential proximity to their adult children, etc. PMID:25213460

Surface air quality implications of volcanic injection heights

NASA Astrophysics Data System (ADS)

Thomas, Manu Anna; Brännström, Niklas; Persson, Christer; Grahn, Håkan; von Schoenberg, Pontus; Robertson, Lennart

2017-10-01

Air quality implications of volcanic eruptions have gained increased attention recently in association with the 2010 Icelandic eruption that resulted in the shut-down of European air space. The emission amount, injection height and prevailing weather conditions determine the extent of the impact through the spatio-temporal distribution of pollutants. It is often argued that in the case of a major eruption in Iceland, like Laki in 1783-1784, that pollutants injected high into the atmosphere lead to substantially increased concentrations of sulfur compounds over continental Europe via long-range transport in the jet stream and eventual large-scale subsidence in a high-pressure system. Using state-of-the-art simulations, we show that the air quality impact of Icelandic volcanoes is highly sensitive to the injection height. In particular, it is the infinitesimal injections into the lower half of the troposphere, rather than the substantial injections into the upper troposphere/lower stratosphere that contribute most to increased pollutant concentrations, resulting in atmospheric haze over mainland Europe/Scandinavia. Besides, the persistent high pressure system over continental Europe/Scandinavia traps the pollutants from dispersing, thereby prolonging the haze.

Assessment of Minimum Important Difference and Substantial Clinical Benefit with the Vascular Quality of Life Questionnaire-6 when Evaluating Revascularisation Procedures in Peripheral Arterial Disease.

PubMed

Nordanstig, J; Pettersson, M; Morgan, M; Falkenberg, M; Kumlien, C

2017-09-01

Patient reported outcomes are increasingly used to assess outcomes after peripheral arterial disease (PAD) interventions. VascuQoL-6 (VQ-6) is a PAD specific health-related quality of life (HRQoL) instrument for routine clinical practice and clinical research. This study assessed the minimum important difference for the VQ-6 and determined thresholds for the minimum important difference and substantial clinical benefit following PAD revascularisation. This was a population-based observational cohort study. VQ-6 data from the Swedvasc Registry (January 2014 to September 2016) was analysed for revascularised PAD patients. The minimum important difference was determined using a combination of a distribution based and an anchor-based method, while receiver operating characteristic curve analysis (ROC) was used to determine optimal thresholds for a substantial clinical benefit following revascularisation. A total of 3194 revascularised PAD patients with complete VQ-6 baseline recordings (intermittent claudication (IC) n = 1622 and critical limb ischaemia (CLI) n = 1572) were studied, of which 2996 had complete VQ-6 recordings 30 days and 1092 a year after the vascular intervention. The minimum important difference 1 year after revascularisation for IC patients ranged from 1.7 to 2.2 scale steps, depending on the method of analysis. Among CLI patients, the minimum important difference after 1 year was 1.9 scale steps. ROC analyses demonstrated that the VQ-6 discriminative properties for a substantial clinical benefit was excellent for IC patients (area under curve (AUC) 0.87, sensitivity 0.81, specificity 0.76) and acceptable in CLI (AUC 0.736, sensitivity 0.63, specificity 0.72). An optimal VQ-6 threshold for a substantial clinical benefit was determined at 3.5 scale steps among IC patients and 4.5 in CLI patients. The suggested thresholds for minimum important difference and substantial clinical benefit could be used when evaluating VQ-6 outcomes following different interventions in PAD and in the design of clinical trials. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

A High Sensitivity Preamplifier for Quartz Tuning Forks in QEPAS (Quartz Enhanced PhotoAcoustic Spectroscopy) Applications

PubMed Central

Starecki, Tomasz

2017-01-01

All the preamplifiers dedicated for Quartz Enhanced PhotoAcoustic Spectroscopy (QEPAS) applications that have so far been reported in the literature have been based on operational amplifiers working in transimpedance configurations. Taking into consideration that QEPAS sensors are based on quartz tuning forks, and that quartz has a relatively high voltage constant and relatively low charge constant, it seems that a transimpedance amplifier is not an optimal solution. This paper describes the design of a quartz QEPAS sensor preamplifier, implemented with voltage amplifier configuration. Discussion of an electrical model of the circuit and preliminary measurements are presented. Both theoretical analysis and experiments show that use of the voltage configuration allows for a substantial increase of the output signal in comparison to the transimpedance circuit with the same tuning fork working in identical conditions. Assuming that the sensitivity of the QEPAS technique depends directly on the properties of the preamplifier, use of the voltage amplifier configuration should result in an increase of QEPAS sensitivity by one to two orders of magnitude. PMID:29099765

A High Sensitivity Preamplifier for Quartz Tuning Forks in QEPAS (Quartz Enhanced PhotoAcoustic Spectroscopy) Applications.

PubMed

Starecki, Tomasz; Wieczorek, Piotr Z

2017-11-03

All the preamplifiers dedicated for Quartz Enhanced PhotoAcoustic Spectroscopy (QEPAS) applications that have so far been reported in the literature have been based on operational amplifiers working in transimpedance configurations. Taking into consideration that QEPAS sensors are based on quartz tuning forks, and that quartz has a relatively high voltage constant and relatively low charge constant, it seems that a transimpedance amplifier is not an optimal solution. This paper describes the design of a quartz QEPAS sensor preamplifier, implemented with voltage amplifier configuration. Discussion of an electrical model of the circuit and preliminary measurements are presented. Both theoretical analysis and experiments show that use of the voltage configuration allows for a substantial increase of the output signal in comparison to the transimpedance circuit with the same tuning fork working in identical conditions. Assuming that the sensitivity of the QEPAS technique depends directly on the properties of the preamplifier, use of the voltage amplifier configuration should result in an increase of QEPAS sensitivity by one to two orders of magnitude.

Functional analysis RaZIP1 transporter of the ZIP family from the ectomycorrhizal Zn-accumulating Russula atropurpurea.

PubMed

Leonhardt, Tereza; Sácký, Jan; Kotrba, Pavel

2018-04-01

A search of R. atropurpurea transcriptome for sequences encoding the transporters of the Zrt-, Irt-like Protein (ZIP) family, which are in eukaryotes integral to Zn supply into cytoplasm, allowed the identification of RaZIP1 cDNA with a predicted product belonging to ZIP I subfamily; it was subjected to functional studies in mutant Saccharomyces cerevisiae strains. The expression of RaZIP1, but not RaZIP1 H208A or RaZIP1 H232A mutants lacking conserved-among-ZIPs transmembrane histidyls, complemented Zn uptake deficiency in zrt1Δzrt2Δ yeasts. RaZIP1 substantially increased cellular Zn uptake in this strain and added to Zn sensitivity in zrc1Δcot1Δ mutant. The Fe uptake deficiency in ftr1Δ strain was not rescued and Mn uptake was insufficient for toxicity in Mn-sensitive pmr1Δ yeasts. By contrast, RaZIP1 increased Cd sensitivity in yap1Δ strain and conferred Cd transport activity in yeasts, albeit with substantially lower efficiency compared to Zn transport. In metal uptake assays, the accumulation of Zn in zrt1Δzrt2Δ strain remained unaffected by Cd, Fe, and Mn present in 20-fold molar excess over Zn. Immunofluorescence microscopy detected functional hemagglutinin-tagged HA::RaZIP1 on the yeast cell protoplast periphery. Altogether, these data indicate that RaZIP1 is a high-affinity plasma membrane transporter specialized in Zn uptake, and improve the understanding of the cellular and molecular biology of Zn in R. atropurpurea that is known for its ability to accumulate remarkably high concentrations of Zn.

Sensitivity, Specificity, and Public-Health Utility of Clinical Case Definitions Based on the Signs and Symptoms of Cholera in Africa.

PubMed

Nadri, Johara; Sauvageot, Delphine; Njanpop-Lafourcade, Berthe-Marie; Baltazar, Cynthia S; Banla Kere, Abiba; Bwire, Godfrey; Coulibaly, Daouda; Kacou N'Douba, Adele; Kagirita, Atek; Keita, Sakoba; Koivogui, Lamine; Landoh, Dadja E; Langa, Jose P; Miwanda, Berthe N; Mutombo Ndongala, Guy; Mwakapeje, Elibariki R; Mwambeta, Jacob L; Mengel, Martin A; Gessner, Bradford D

2018-04-01

During 2014, Africa reported more than half of the global suspected cholera cases. Based on the data collected from seven countries in the African Cholera Surveillance Network (Africhol), we assessed the sensitivity, specificity, and positive and negative predictive values of clinical cholera case definitions, including that recommended by the World Health Organization (WHO) using culture confirmation as the gold standard. The study was designed to assess results in real-world field situations in settings with recent cholera outbreaks or endemicity. From June 2011 to July 2015, a total of 5,084 persons with suspected cholera were tested for Vibrio cholerae in seven different countries of which 35.7% had culture confirmation. For all countries combined, the WHO case definition had a sensitivity = 92.7%, specificity = 8.1%, positive predictive value = 36.1%, and negative predictive value = 66.6%. Adding dehydration, vomiting, or rice water stools to the case definition could increase the specificity without a substantial decrease in sensitivity. Future studies could further refine our findings primarily by using more sensitive methods for cholera confirmation.

Land Use and Land Cover Change in the Qinghai Lake Region of the Tibetan Plateau and Its Impact on Ecosystem Services

PubMed Central

Gong, Jian; Yang, Jianxin; Tang, Wenwu

2017-01-01

Exploration of land use and land cover change (LULCC) and its impacts on ecosystem services in Tibetan plateau is valuable for landscape and environmental conservation. In this study, we conduct spatial analysis on empirical land use and land cover data in the Qinghai Lake region for 1990, 2000, and 2010 and simulate land cover patterns for 2020. We then evaluate the impacts of LULCC on ecosystem service value (ESV), and analyze the sensitivity of ESV to LULCC to identify the ecologically sensitive area. Our results indicate that, from 1990 to 2010, the area of forest and grassland increased while the area of unused land decreased. Simulation results suggest that the area of grassland and forest will continue to increase and the area of cropland and unused land will decrease for 2010–2020. The ESV in the study area increased from 694.50 billion Yuan in 1990 to 714.28 billion Yuan in 2000, and to 696.72 billion Yuan in 2020. Hydrology regulation and waste treatment are the top two ecosystem services in this region. The towns surrounding the Qinghai Lake have high ESVs, especially in the north of the Qinghai Lake. The towns with high ESV sensitivity to LULCC are located in the northwest, while the towns in the north of the Qinghai Lake experienced substantial increase in sensitivity index from 2000–2010 to 2010–2020, especially for three regulation services and aesthetic landscape provision services. PMID:28754029

Land Use and Land Cover Change in the Qinghai Lake Region of the Tibetan Plateau and Its Impact on Ecosystem Services.

PubMed

Gong, Jian; Li, Jingye; Yang, Jianxin; Li, Shicheng; Tang, Wenwu

2017-07-21

Exploration of land use and land cover change (LULCC) and its impacts on ecosystem services in Tibetan plateau is valuable for landscape and environmental conservation. In this study, we conduct spatial analysis on empirical land use and land cover data in the Qinghai Lake region for 1990, 2000, and 2010 and simulate land cover patterns for 2020. We then evaluate the impacts of LULCC on ecosystem service value (ESV), and analyze the sensitivity of ESV to LULCC to identify the ecologically sensitive area. Our results indicate that, from 1990 to 2010, the area of forest and grassland increased while the area of unused land decreased. Simulation results suggest that the area of grassland and forest will continue to increase and the area of cropland and unused land will decrease for 2010-2020. The ESV in the study area increased from 694.50 billion Yuan in 1990 to 714.28 billion Yuan in 2000, and to 696.72 billion Yuan in 2020. Hydrology regulation and waste treatment are the top two ecosystem services in this region. The towns surrounding the Qinghai Lake have high ESVs, especially in the north of the Qinghai Lake. The towns with high ESV sensitivity to LULCC are located in the northwest, while the towns in the north of the Qinghai Lake experienced substantial increase in sensitivity index from 2000-2010 to 2010-2020, especially for three regulation services and aesthetic landscape provision services.

Application of OMI Observations to a Space-Based Indicator of NOx and VOC Controls on Surface Ozone Formation

NASA Technical Reports Server (NTRS)

Duncan, Bryan N.; Yoshida, Yasuko; Olson, Jennifer R.; Sillman, Sanford; Martin, Randall V.; Lamsal, Lok; Hu, Yongtao; Pickering, Kenneth E.; Retscher, Christian; Allen, Dale J.;

Origin of embrittlement in metallic glasses

PubMed Central

Garrett, Glenn R.; Demetriou, Marios D.; Launey, Maximilien E.; Johnson, William L.

2016-01-01

Owing to their glassy nature, metallic glasses demonstrate a toughness that is extremely sensitive to the frozen-in configurational state. This sensitivity gives rise to “annealing embrittlement,” which is often severe and in many respects limits the technological advancement of these materials. Here, equilibrium configurations (i.e., “inherent states”) of a metallic glass are established around the glass transition, and the configurational properties along with the plane-strain fracture toughness are evaluated to associate the intrinsic glass toughness with the inherent state properties and identify the fundamental origin of embrittlement. The established correlations reveal a one-to-one correspondence between toughness and shear modulus continuous over a broad range of inherent states, suggesting that annealing embrittlement is controlled almost solely by an increasing resistance to shear flow. This annealing embrittlement sensitivity is shown to vary substantially between metallic glass compositions, and appears to correlate well with the fragility of the metallic glass. PMID:27573817

Fall season atypically warm weather event leads to substantial CH4 loss in Arctic ecosystems?

NASA Astrophysics Data System (ADS)

Zona, Donatella; Moreaux, Virginie; Liljedahl, Anna; Losacco, Salvatore; Murphy, Patrick; Oechel, Walter

2014-05-01

In the last century (during 1875-2008) high-latitudes are warming at a rate of 1.360C century-1, almost 2 times faster than the Northern Hemisphere trend (Bekryaev et al., 2010). This warming has been more intense outside of the summer season, with anomalies of 1.09, 1.59, 1.730C in the fall, winter, and spring season respectively (Bekryaev et al., 2010). This substantial temperature anomalies have the potential to increase the emission of greenhouse gas (CO2 and CH4) fluxes from arctic tundra ecosystems. In particular, CH4 emissions, which are primarily controlled by temperature (in addition to water table), can steeply increase with warming. Despite the potential relevance of CH4 emissions, very few measurements have been performed outside of the growing season across the entire Arctic, due to logistic constrains. Importantly, no flux measurements achieved a temporal and spatial data coverage sufficient to estimate with confidence an annual CH4 emissions from tundra ecosystem in Alaska, and its sensitivity to warming. Fall 2013 was unusually warm in central and northern Alaska. Following a relatively warm summer with dramatically above-average rainfall, the October mean monthly temperatures was the 4th and top warmest in Barrow (1949-2013) and Ivotuk (1998-2013), respectively. As we just upgraded several eddy covariance towers to measure CO2 and CH4 fluxes year-round, the atypical weather conditions of fall 2013 represented a unique chance for testing the sensitivity of CH4 loss to these atypically warm temperatures. All our sites across a latitudinal gradient (from the northern site, Barrow, to the southern site, Ivotuk), presented substantial CH4 loss in the fall. Importantly, in two of these sites (Barrow, Ivotuk) where the fall weather was substantially warmer than the long term trend, fall CH4 emission represented between 44-63% of the June-November cumulative emission. Surprisingly, in the southernmost site (Ivotuk), when the temperature anomaly was the highest, cumulative fall CH4 emission outpaced even the summer emission. This shows the sensitivity of CH4 loss to abnormal conditions, and the importance of fall periods for the annual CH4 budget in these Arctic ecosystems. Bekryaev, R. V., I. V. Polyakov, and V. A. Alexeev. 2010. Role of polar amplification in long-term surface air temperature variations and modern Arctic warming. Journal of Climate 23(14):3888-3906.

Asymmetric responses of primary productivity to precipitation extremes: A synthesis of grassland precipitation manipulation experiments

DOE PAGES

Wilcox, Kevin R.; Shi, Zheng; Gherardi, Laureano A.; ...

2017-04-02

Climatic changes are altering Earth's hydrological cycle, resulting in altered precipitation amounts, increased interannual variability of precipitation, and more frequent extreme precipitation events. These trends will likely continue into the future, having substantial impacts on net primary productivity (NPP) and associated ecosystem services such as food production and carbon sequestration. Frequently, experimental manipulations of precipitation have linked altered precipitation regimes to changes in NPP. Yet, findings have been diverse and substantial uncertainty still surrounds generalities describing patterns of ecosystem sensitivity to altered precipitation. Additionally, we do not know whether previously observed correlations between NPP and precipitation remain accurate when precipitationmore » changes become extreme. We synthesized results from 83 case studies of experimental precipitation manipulations in grasslands worldwide. Here, we used meta-analytical techniques to search for generalities and asymmetries of aboveground NPP (ANPP) and belowground NPP (BNPP) responses to both the direction and magnitude of precipitation change. Sensitivity (i.e., productivity response standardized by the amount of precipitation change) of BNPP was similar under precipitation additions and reductions, but ANPP was more sensitive to precipitation additions than reductions; this was especially evident in drier ecosystems. Additionally, overall relationships between the magnitude of productivity responses and the magnitude of precipitation change were saturating in form. The saturating form of this relationship was likely driven by ANPP responses to very extreme precipitation increases, although there were limited studies imposing extreme precipitation change, and there was considerable variation among experiments. Finally, this highlights the importance of incorporating gradients of manipulations, ranging from extreme drought to extreme precipitation increases into future climate change experiments. Additionally, policy and land management decisions related to global change scenarios should consider how ANPP and BNPP responses may differ, and that ecosystem responses to extreme events might not be predicted from relationships found under moderate environmental changes.« less

Asymmetric responses of primary productivity to precipitation extremes: A synthesis of grassland precipitation manipulation experiments.

PubMed

Wilcox, Kevin R; Shi, Zheng; Gherardi, Laureano A; Lemoine, Nathan P; Koerner, Sally E; Hoover, David L; Bork, Edward; Byrne, Kerry M; Cahill, James; Collins, Scott L; Evans, Sarah; Gilgen, Anna K; Holub, Petr; Jiang, Lifen; Knapp, Alan K; LeCain, Daniel; Liang, Junyi; Garcia-Palacios, Pablo; Peñuelas, Josep; Pockman, William T; Smith, Melinda D; Sun, Shanghua; White, Shannon R; Yahdjian, Laura; Zhu, Kai; Luo, Yiqi

2017-10-01

Climatic changes are altering Earth's hydrological cycle, resulting in altered precipitation amounts, increased interannual variability of precipitation, and more frequent extreme precipitation events. These trends will likely continue into the future, having substantial impacts on net primary productivity (NPP) and associated ecosystem services such as food production and carbon sequestration. Frequently, experimental manipulations of precipitation have linked altered precipitation regimes to changes in NPP. Yet, findings have been diverse and substantial uncertainty still surrounds generalities describing patterns of ecosystem sensitivity to altered precipitation. Additionally, we do not know whether previously observed correlations between NPP and precipitation remain accurate when precipitation changes become extreme. We synthesized results from 83 case studies of experimental precipitation manipulations in grasslands worldwide. We used meta-analytical techniques to search for generalities and asymmetries of aboveground NPP (ANPP) and belowground NPP (BNPP) responses to both the direction and magnitude of precipitation change. Sensitivity (i.e., productivity response standardized by the amount of precipitation change) of BNPP was similar under precipitation additions and reductions, but ANPP was more sensitive to precipitation additions than reductions; this was especially evident in drier ecosystems. Additionally, overall relationships between the magnitude of productivity responses and the magnitude of precipitation change were saturating in form. The saturating form of this relationship was likely driven by ANPP responses to very extreme precipitation increases, although there were limited studies imposing extreme precipitation change, and there was considerable variation among experiments. This highlights the importance of incorporating gradients of manipulations, ranging from extreme drought to extreme precipitation increases into future climate change experiments. Additionally, policy and land management decisions related to global change scenarios should consider how ANPP and BNPP responses may differ, and that ecosystem responses to extreme events might not be predicted from relationships found under moderate environmental changes. © 2017 John Wiley & Sons Ltd.

Sensitivity of southern hemisphere westerly wind to boundary conditions for the last glacial maximum

NASA Astrophysics Data System (ADS)

Jun, S. Y.; Kim, S. J.; Kim, B. M.

2017-12-01

To examine the change in SH westerly wind in the LGM, we performed LGM simulation with sensitivity experiments by specifying the LGM sea ice in the Southern Ocean (SO), ice sheet over Antarctica, and tropical pacific sea surface temperature to CAM5 atmosphere general circulation model (GCM). The SH westerly response to LGM boundary conditions in the CAM5 was compared with those from CMIP5 LGM simulations. In the CAM5 LGM simulation, the SH westerly wind substantially increases between 40°S and 65°S, while the zonal-mean zonal wind decreases at latitudes higher than 65°S. The position of the SH maximum westerly wind moves poleward by about 8° in the LGM simulation. Sensitivity experiments suggest that the increase in SH westerly winds is mainly due to the increase in sea ice in the SO that accounts for 60% of total wind change. In the CMIP5-PMIP3 LGM experiments, most of the models show the slight increase and poleward shift of the SH westerly wind as in the CAM5 experiment. The increased and poleward shifted westerly wind in the LGM obtained in the current model result is consistent with previous model results and some lines of proxy evidence, though opposite model responses and proxy evidence exist for the SH westerly wind change.

Comparison between surrogate indexes of insulin sensitivity/resistance and hyperinsulinemic euglycemic clamp estimates in rats

PubMed Central

Muniyappa, Ranganath; Chen, Hui; Muzumdar, Radhika H.; Einstein, Francine H.; Yan, Xu; Yue, Lilly Q.; Barzilai, Nir

2009-01-01

Assessing insulin resistance in rodent models gives insight into mechanisms that cause type 2 diabetes and the metabolic syndrome. The hyperinsulinemic euglycemic glucose clamp, the reference standard for measuring insulin sensitivity in humans and animals, is labor intensive and technically demanding. A number of simple surrogate indexes of insulin sensitivity/resistance have been developed and validated primarily for use in large human studies. These same surrogates are also frequently used in rodent studies. However, in general, these indexes have not been rigorously evaluated in animals. In a recent validation study in mice, we demonstrated that surrogates have a weaker correlation with glucose clamp estimates of insulin sensitivity/resistance than in humans. This may be due to increased technical difficulties in mice and/or intrinsic differences between human and rodent physiology. To help distinguish among these possibilities, in the present study, using data from rats substantially larger than mice, we compared the clamp glucose infusion rate (GIR) with surrogate indexes, including QUICKI, HOMA, 1/HOMA, log (HOMA), and 1/fasting insulin. All surrogates were modestly correlated with GIR (r = 0.34–0.40). Calibration analyses of surrogates adjusted for body weight demonstrated similar predictive accuracy for GIR among all surrogates. We conclude that linear correlations of surrogate indexes with clamp estimates and predictive accuracy of surrogate indexes in rats are similar to those in mice (but not as substantial as in humans). This additional rat study (taken with the previous mouse study) suggests that application of surrogate insulin sensitivity indexes developed for humans may not be appropriate for determining primary outcomes in rodent studies due to intrinsic differences in metabolic physiology. However, use of surrogates may be appropriate in rodents, where feasibility of clamps is an obstacle and measurement of insulin sensitivity is a secondary outcome. PMID:19706785

Climate change impacts on selected global rangeland ecosystem services.

PubMed

Boone, Randall B; Conant, Richard T; Sircely, Jason; Thornton, Philip K; Herrero, Mario

2018-03-01

Rangelands are Earth's dominant land cover and are important providers of ecosystem services. Reliance on rangelands is projected to grow, thus understanding the sensitivity of rangelands to future climates is essential. We used a new ecosystem model of moderate complexity that allows, for the first time, to quantify global changes expected in rangelands under future climates. The mean global annual net primary production (NPP) may decline by 10 g C m -2  year -1 in 2050 under Representative Concentration Pathway (RCP) 8.5, but herbaceous NPP is projected to increase slightly (i.e., average of 3 g C m -2  year -1 ). Responses vary substantially from place-to-place, with large increases in annual productivity projected in northern regions (e.g., a 21% increase in productivity in the US and Canada) and large declines in western Africa (-46% in sub-Saharan western Africa) and Australia (-17%). Soil organic carbon is projected to increase in Australia (9%), the Middle East (14%), and central Asia (16%) and decline in many African savannas (e.g., -18% in sub-Saharan western Africa). Livestock are projected to decline 7.5 to 9.6%, an economic loss of from $9.7 to $12.6 billion. Our results suggest that forage production in Africa is sensitive to changes in climate, which will have substantial impacts on the livelihoods of the more than 180 million people who raise livestock on those rangelands. Our approach and the simulation tool presented here offer considerable potential for forecasting future conditions, highlight regions of concern, and support analyses where costs and benefits of adaptations and policies may be quantified. Otherwise, the technical options and policy and enabling environment that are needed to facilitate widespread adaptation may be very difficult to elucidate. © 2017 John Wiley & Sons Ltd.

Emissions pathways, climate change, and impacts on California

PubMed Central

Hayhoe, Katharine; Cayan, Daniel; Field, Christopher B.; Frumhoff, Peter C.; Maurer, Edwin P.; Miller, Norman L.; Moser, Susanne C.; Schneider, Stephen H.; Cahill, Kimberly Nicholas; Cleland, Elsa E.; Dale, Larry; Drapek, Ray; Hanemann, R. Michael; Kalkstein, Laurence S.; Lenihan, James; Lunch, Claire K.; Neilson, Ronald P.; Sheridan, Scott C.; Verville, Julia H.

2004-01-01

The magnitude of future climate change depends substantially on the greenhouse gas emission pathways we choose. Here we explore the implications of the highest and lowest Intergovernmental Panel on Climate Change emissions pathways for climate change and associated impacts in California. Based on climate projections from two state-of-the-art climate models with low and medium sensitivity (Parallel Climate Model and Hadley Centre Climate Model, version 3, respectively), we find that annual temperature increases nearly double from the lower B1 to the higher A1fi emissions scenario before 2100. Three of four simulations also show greater increases in summer temperatures as compared with winter. Extreme heat and the associated impacts on a range of temperature-sensitive sectors are substantially greater under the higher emissions scenario, with some interscenario differences apparent before midcentury. By the end of the century under the B1 scenario, heatwaves and extreme heat in Los Angeles quadruple in frequency while heat-related mortality increases two to three times; alpine/subalpine forests are reduced by 50–75%; and Sierra snowpack is reduced 30–70%. Under A1fi, heatwaves in Los Angeles are six to eight times more frequent, with heat-related excess mortality increasing five to seven times; alpine/subalpine forests are reduced by 75–90%; and snowpack declines 73–90%, with cascading impacts on runoff and streamflow that, combined with projected modest declines in winter precipitation, could fundamentally disrupt California's water rights system. Although interscenario differences in climate impacts and costs of adaptation emerge mainly in the second half of the century, they are strongly dependent on emissions from preceding decades. PMID:15314227

Rapid determination of surfactant critical micelle concentration in aqueous solutions using fiber-optic refractive index sensing.

PubMed

Tan, Chun Hua; Huang, Zhen Jian; Huang, Xu Guang

2010-06-01

We describe a simple and rapid method for determining the critical micelle concentration (CMC) of surfactants from fiber-optic measurements of refractive index. The refractive index of an aqueous surfactant solution was monitored as the surfactant concentration was increased using an automated dispensing system. On reaching the surfactant's CMC value, an abrupt change was observed in the rate of increase of the refractive index with increasing concentration. The measurement system provides rapid semiautomatic data collection and analysis, increasing the precision, sensitivity, and range of applicability of the technique while substantially decreasing the amount of manual intervention required. Measurements of CMC for sodium dodecyl sulfate (8.10mM), cetyltrimethylammonium chloride (1.58mM), and Triton X-100 (0.21mM) were in excellent agreement with values previously reported in the literature. The method is applicable to cationic, anionic, and nonionic surfactants, and it offers a facile, in situ, and sensitive means of detecting micelle formation over a broad range of CMC values larger than 10(-1)mM. Copyright 2010 Elsevier Inc. All rights reserved.

Immunosuppressive effects of lead

USGS Publications Warehouse

Franson, J. Christian; Feierabend, J.Scott; Russell, A.Brooke

1986-01-01

Immunosuppressive effects of lead were reported as early as 1966, when it was noted that lead increased the sensitivity of rats to bacterial endotoxins (Selye et al. 1966). Since then a substantial body of literature has demonstrated adverse effects of lead on the immune system in a variety of laboratory animals, but very little has been done in this area with avian species. Such immunosuppressive effects could be of significance to waterfowl populations, considering the potential for lead ingestion by waterfowl and subsequent exposure of these birds to disease agents.

Bridging the Gap: Racial concordance as a strategy to increase African American participation in breast cancer research.

PubMed

Frierson, Georita M; Pinto, Bernardine M; Denman, Deanna C; Leon, Pierre A; Jaffe, Alex D

2017-11-01

Lack of African American females in breast cancer research has been receiving substantial attention. This study seeks to identify research perceptions and motivating factors needed to increase racial/ethnic minority participation in breast cancer research. A total of 57 African American women (Σ = 47.8 years), from Rhode Island and Texas, completed a questionnaire and focus group. While many participants were not breast cancer survivors, they reported knowledge of their racial group's risk for breast cancer. One major finding that could be seen as both a facilitator and barrier is racial concordance between participant and researcher. Cultural sensitivity and trust building is recommended to increase minority participation.

Migration, Remittances, and Educational Stratification among Blacks in Apartheid and Post-Apartheid South Africa.

PubMed

Lu, Yao; Treiman, Donald J

2011-06-01

This paper extends previous work on family structure and children's education by conceptualizing migration as a distinct form of family disruption that reduces parental input but brings substantial economic benefits through remittances. It examines the multiple and countervailing effects of migration on schooling in the context of substantial migration and limited educational opportunities for Blacks in South Africa. The receipt of remittances substantially increases Black children's school attendance, but has no such effect for Whites. The effect for Blacks is in part attributable to improved household economic conditions that increase household educational spending and reduce the demand for child labor. We also find a negative effect of parental absence due to migration, but it is largely cushioned by inflows of remittances. Sensitivity analyses using propensity score methods and contextual fixed-effect modeling suggest that the beneficial effect of remittances is relatively robust. We find further that remittances help ameliorate inter-familial socioeconomic inequality in schooling. Finally, we evaluate possible temporal changes and show that the positive and equalizing effects of remittances persisted during and after the apartheid regime. We conclude that labor migration and remittances, as institutionalized family strategies adopted by many Blacks, help reconfigure structural opportunities in the educational stratification process in South Africa.

Parenting responsibility expectations of senior Australian dental students: do the next generations' family responsibilities impact workforce planning?

PubMed

Alsharif, Ala'a; Kruger, Estie; Tennant, Marc

2012-10-01

Over the past twenty-five years, there has been a substantial increase in work-based demands, thought to be due to an intensifying, competitive work environment. However, more recently, the question of work-life balance is increasingly attracting attention. The purpose of this study was to discover the attitudes of the next generation of dentists in Australia to parenting responsibility and work-life balance perceptions. Questionnaires on work-life balance were distributed to all fourth-year students at three dental schools in Australia. A total of 137 (76 percent) surveys were completed and returned. Most respondents indicated that they would take time off to focus on childcare, and just over half thought childcare should be shared by both parents. Thirty-seven percent felt that a child would have a considerable effect on their careers. Differences were seen in responses when compared by gender. The application of sensitivity analysis to workforce calculations based around changing societal work-life expectations can have substantial effects on predicting workforce data a decade into the future. It is not just the demographic change to a more feminized workforce in Australia that can have substantial effect, but also the change in social expectations of males in regards to parenting.

Migration, Remittances, and Educational Stratification among Blacks in Apartheid and Post-Apartheid South Africa

PubMed Central

Lu, Yao; Treiman, Donald J.

2013-01-01

This paper extends previous work on family structure and children’s education by conceptualizing migration as a distinct form of family disruption that reduces parental input but brings substantial economic benefits through remittances. It examines the multiple and countervailing effects of migration on schooling in the context of substantial migration and limited educational opportunities for Blacks in South Africa. The receipt of remittances substantially increases Black children’s school attendance, but has no such effect for Whites. The effect for Blacks is in part attributable to improved household economic conditions that increase household educational spending and reduce the demand for child labor. We also find a negative effect of parental absence due to migration, but it is largely cushioned by inflows of remittances. Sensitivity analyses using propensity score methods and contextual fixed-effect modeling suggest that the beneficial effect of remittances is relatively robust. We find further that remittances help ameliorate inter-familial socioeconomic inequality in schooling. Finally, we evaluate possible temporal changes and show that the positive and equalizing effects of remittances persisted during and after the apartheid regime. We conclude that labor migration and remittances, as institutionalized family strategies adopted by many Blacks, help reconfigure structural opportunities in the educational stratification process in South Africa. PMID:23935219

Impact of weak water deficit on growth, photosynthetic primary processes and storage processes in pine and spruce seedlings.

PubMed

Zlobin, Ilya E; Ivanov, Yury V; Kartashov, Alexander V; Sarvin, Boris A; Stavrianidi, Andrey N; Kreslavski, Vladimir D; Kuznetsov, Vladimir V

2018-05-19

We investigated the influence of 40 days of drought on growth, storage processes and primary photosynthetic processes in 3-month-old Scots pine and Norway spruce seedlings growing in perlite culture. Water stress significantly affected seedling water status, whereas absolute dry biomass growth was not substantially influenced. Water stress induced an increase in non-structural carbohydrate content (sugars, sugar alcohols, starch) in the aboveground part of pine seedlings in contrast to spruce seedlings. Due to the relatively low content of sugars and sugar alcohols in seedling organs, their expected contribution to osmotic potential changes was quite low. In contrast to biomass accumulation and storage, photosynthetic primary processes were substantially influenced by water shortage. In spruce seedlings, PSII was more sensitive to water stress than PSI. In particular, electron transport in PSI was stable under water stress despite the substantial decrease of electron transport in PSII. The increase in thermal energy dissipation due to enhancement of non-photochemical quenching (NPQ) was evident in both species under water stress. Simultaneously, the yields of non-regulated energy dissipation in PSII were decreased in pine seedlings under drought. A relationship between growth, photosynthetic activities and storage processes is analysed under weak water deficit.

Protection of microelectronic devices during packaging

DOEpatents

Peterson, Kenneth A.; Conley, William R.

2002-01-01

The present invention relates to a method of protecting a microelectronic device during device packaging, including the steps of applying a water-insoluble, protective coating to a sensitive area on the device; performing at least one packaging step; and then substantially removing the protective coating, preferably by dry plasma etching. The sensitive area can include a released MEMS element. The microelectronic device can be disposed on a wafer. The protective coating can be a vacuum vapor-deposited parylene polymer, silicon nitride, metal (e.g. aluminum or tungsten), a vapor deposited organic material, cynoacrylate, a carbon film, a self-assembled monolayered material, perfluoropolyether, hexamethyldisilazane, or perfluorodecanoic carboxylic acid, silicon dioxide, silicate glass, or combinations thereof. The present invention also relates to a method of packaging a microelectronic device, including: providing a microelectronic device having a sensitive area; applying a water-insoluble, protective coating to the sensitive area; providing a package; attaching the device to the package; electrically interconnecting the device to the package; and substantially removing the protective coating from the sensitive area.

Temporary coatings for protection of microelectronic devices during packaging

DOEpatents

Peterson, Kenneth A.; Conley, William R.

2005-01-18

The present invention relates to a method of protecting a microelectronic device during device packaging, including the steps of applying a water-insoluble, temporary protective coating to a sensitive area on the device; performing at least one packaging step; and then substantially removing the protective coating, preferably by dry plasma etching. The sensitive area can include a released MEMS element. The microelectronic device can be disposed on a wafer. The protective coating can be a vacuum vapor-deposited parylene polymer, silicon nitride, metal (e.g. aluminum or tungsten), a vapor deposited organic material, cynoacrylate, a carbon film, a self-assembled monolayered material, perfluoropolyether, hexamethyldisilazane, or perfluorodecanoic carboxylic acid, silicon dioxide, silicate glass, or combinations thereof. The present invention also relates to a method of packaging a microelectronic device, including: providing a microelectronic device having a sensitive area; applying a water-insoluble, protective coating to the sensitive area; providing a package; attaching the device to the package; electrically interconnecting the device to the package; and substantially removing the protective coating from the sensitive area.

The potential of low-power laser for reducing dental sensitivity after in-office bleaching: a case report.

PubMed

Mayer-Santos, Eric; Anhesini, Brunna Haddad; Shimokawa, Carlos Alberto Kenji; Aranha, Ana Cecília Corrêa; Eduardo, Carlos Paula; de Freitas, Patricia Moreira

2017-01-01

Postoperative sensitivity is one of the most common side effects of in-office bleaching with hydrogen peroxide. Laser phototherapy (LPT) has been suggested as an adjunctive treatment to prevent or minimize tooth sensitivity. This case report aimed to verify the efficacy of LPT in the reduction of sensitivity after in-office bleaching. Tooth bleaching was performed with 35% hydrogen peroxide activated with a hybrid LED-laser device. Immediately after the bleaching treatment, the patient reported dental sensitivity, as measured with a visual analog scale (VAS). To reduce sensitivity, LPT was applied with a 780-nm laser using the following parameters: 70 mW, exposure time of 10 seconds per point of irradiation (middle region of the buccal surfaces of each compromised tooth) in contact mode, energy of 1 J per point. Immediately after LPT, the patient reported a substantially lower level of pain on the VAS. Twenty-four hours after bleaching, the score on the VAS indicated that sensitivity levels had rebounded, and the patient received additional LPT. After 48 hours, the patient reported no dental sensitivity. The results in this patient indicated that irradiation with an infrared low-power laser substantially reduced dental pain generated by bleaching, suggesting that LPT should be considered as an auxiliary method to reduce postbleaching tooth sensitivity.

Accuracy of screening women at familial risk of breast cancer without a known gene mutation: Individual patient data meta-analysis.

PubMed

Phi, Xuan-Anh; Houssami, Nehmat; Hooning, Maartje J; Riedl, Christopher C; Leach, Martin O; Sardanelli, Francesco; Warner, Ellen; Trop, Isabelle; Saadatmand, Sepideh; Tilanus-Linthorst, Madeleine M A; Helbich, Thomas H; van den Heuvel, Edwin R; de Koning, Harry J; Obdeijn, Inge-Marie; de Bock, Geertruida H

2017-11-01

Women with a strong family history of breast cancer (BC) and without a known gene mutation have an increased risk of developing BC. We aimed to investigate the accuracy of screening using annual mammography with or without magnetic resonance imaging (MRI) for these women outside the general population screening program. An individual patient data (IPD) meta-analysis was conducted using IPD from six prospective screening trials that had included women at increased risk for BC: only women with a strong familial risk for BC and without a known gene mutation were included in this analysis. A generalised linear mixed model was applied to estimate and compare screening accuracy (sensitivity, specificity and predictive values) for annual mammography with or without MRI. There were 2226 women (median age: 41 years, interquartile range 35-47) with 7478 woman-years of follow-up, with a BC rate of 12 (95% confidence interval 9.3-14) in 1000 woman-years. Mammography screening had a sensitivity of 55% (standard error of mean [SE] 7.0) and a specificity of 94% (SE 1.3). Screening with MRI alone had a sensitivity of 89% (SE 4.6) and a specificity of 83% (SE 2.8). Adding MRI to mammography increased sensitivity to 98% (SE 1.8, P < 0.01 compared to mammography alone) but lowered specificity to 79% (SE 2.7, P < 0.01 compared with mammography alone). In this population of women with strong familial BC risk but without a known gene mutation, in whom BC incidence was high both before and after age 50, adding MRI to mammography substantially increased screening sensitivity but also decreased its specificity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular epidemiology of antibiotic resistance of Salmonella enteritidis during a 7-year period in Greece.

PubMed Central

Tassios, P T; Markogiannakis, A; Vatopoulos, A C; Katsanikou, E; Velonakis, E N; Kourea-Kremastinou, J; Legakis, N J

1997-01-01

A significant increase in the frequency of isolation of Salmonella enteritidis has been observed during recent years in Greece, parallelled by an increasing rate of resistance of this organism to antibiotics. A substantial proportion of ampicillin- and doxycycline-resistant isolates exhibited cross-resistance to drugs of other classes, such as sulfonamides and streptomycin. Isolates of human origin were overall less resistant than those of animal or food-feed origin. Indeed, strains associated with animal infections were characterized by the highest rates of resistance to several antibiotics. These phenotypic data were correlated with genotypic information concerning two distinct populations: isolates from all sources that were resistant only to ampicillin, the drug toward which resistance rates were highest, and a control group of sensitive isolates. Ampicillin resistance was due to a 34-MDa conjugative plasmid. DNA fingerprinting by macrorestriction of genomic DNA revealed two types, A and B, common to both ampicillin-resistant and -sensitive strains, with 80 to 90% of strains being of type A. However, a third type, C, was specific for the sensitive population, representing 17% of those strains. Therefore, although the majority of resistant isolates were genetically related to sensitive ones, there existed a susceptible clone which had not acquired any resistance traits. PMID:9163436

The resolution sensitivity of the South Asian monsoon and Indo-Pacific in a global 0.35° AGCM

NASA Astrophysics Data System (ADS)

Johnson, Stephanie J.; Levine, Richard C.; Turner, Andrew G.; Martin, Gill M.; Woolnough, Steven J.; Schiemann, Reinhard; Mizielinski, Matthew S.; Roberts, Malcolm J.; Vidale, Pier Luigi; Demory, Marie-Estelle; Strachan, Jane

2016-02-01

The South Asian monsoon is one of the most significant manifestations of the seasonal cycle. It directly impacts nearly one third of the world's population and also has substantial global influence. Using 27-year integrations of a high-resolution atmospheric general circulation model (Met Office Unified Model), we study changes in South Asian monsoon precipitation and circulation when horizontal resolution is increased from approximately 200-40 km at the equator (N96-N512, 1.9°-0.35°). The high resolution, integration length and ensemble size of the dataset make this the most extensive dataset used to evaluate the resolution sensitivity of the South Asian monsoon to date. We find a consistent pattern of JJAS precipitation and circulation changes as resolution increases, which include a slight increase in precipitation over peninsular India, changes in Indian and Indochinese orographic rain bands, increasing wind speeds in the Somali Jet, increasing precipitation over the Maritime Continent islands and decreasing precipitation over the northern Maritime Continent seas. To diagnose which resolution-related processes cause these changes, we compare them to published sensitivity experiments that change regional orography and coastlines. Our analysis indicates that improved resolution of the East African Highlands results in the improved representation of the Somali Jet and further suggests that improved resolution of orography over Indochina and the Maritime Continent results in more precipitation over the Maritime Continent islands at the expense of reduced precipitation further north. We also evaluate the resolution sensitivity of monsoon depressions and lows, which contribute more precipitation over northeast India at higher resolution. We conclude that while increasing resolution at these scales does not solve the many monsoon biases that exist in GCMs, it has a number of small, beneficial impacts.

Developmental Programming: Impact of Gestational Steroid and Metabolic Milieus on Adiposity and Insulin Sensitivity in Prenatal Testosterone-Treated Female Sheep.

PubMed

Cardoso, Rodolfo C; Veiga-Lopez, Almudena; Moeller, Jacob; Beckett, Evan; Pease, Anthony; Keller, Erica; Madrigal, Vanessa; Chazenbalk, Gregorio; Dumesic, Daniel; Padmanabhan, Vasantha

2016-02-01

Prenatally testosterone (T)-treated sheep present metabolic disruptions similar to those seen in women with polycystic ovary syndrome. These females exhibit an increased ratio of small to large adipocytes, which may be the earliest event in the development of adult insulin resistance. Additionally, our longitudinal studies suggest the existence of a period of compensatory adaptation during development. This study tested whether 1) in utero cotreatment of prenatally T-treated sheep with androgen antagonist (flutamide) or insulin sensitizer (rosiglitazone) prevents juvenile insulin resistance and adult changes in adipocyte size; and 2) visceral adiposity and insulin sensitivity are both unaltered during early adulthood, confirming the predicted developmental trajectory in this animal model. Insulin sensitivity was tested during juvenile development and adipose tissue distribution, adipocyte size, and concentrations of adipokines were determined during early adulthood. Prenatal T-treated females manifested juvenile insulin resistance, which was prevented by prenatal rosiglitazone cotreatment. Neither visceral adiposity nor insulin sensitivity differed between groups during early adulthood. Prenatal T-treated sheep presented an increase in the relative proportion of small adipocytes, which was not substantially prevented by either prenatal intervention. A large effect size was observed for increased leptin concentrations in prenatal T-treated sheep compared with controls, which was prevented by prenatal rosiglitazone. In conclusion, gestational alterations in insulin-glucose homeostasis likely play a role in programming insulin resistance, but not adipocyte size distribution, in prenatal T-treated sheep. Furthermore, these results support the notion that a period of compensatory adaptation of the metabolic system to prenatal T exposure occurs between puberty and adulthood.

Sensitivity of endoscopic ultrasound, multidetector computed tomography, and magnetic resonance cholangiopancreatography in the diagnosis of pancreas divisum: a tertiary center experience.

PubMed

Kushnir, Vladimir M; Wani, Sachin B; Fowler, Kathryn; Menias, Christine; Varma, Rakesh; Narra, Vamsi; Hovis, Christine; Murad, Faris M; Mullady, Daniel K; Jonnalagadda, Sreenivasa S; Early, Dayna S; Edmundowicz, Steven A; Azar, Riad R

2013-04-01

There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: (1) evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP), and multidetector computed tomography (MDCT) for pancreas divisum; and (2) assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent endoscopic retrograde pancreatography and cross-sectional imaging. The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than the sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) (P < 0.001 for each). On review by expert radiologists, the sensitivity of MDCT increased to 83.3% in cases where the pancreatic duct was visualized, with fair IOA (κ = 0.34). Expert review of MRCPs did not identify any additional cases of pancreas divisum; IOA was moderate (κ = 0.43). Endoscopic ultrasound is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum.

Method for modeling driving cycles, fuel use, and emissions for over snow vehicles.

PubMed

Hu, Jiangchuan; Frey, H Christopher; Sandhu, Gurdas S; Graver, Brandon M; Bishop, Gary A; Schuchmann, Brent G; Ray, John D

2014-07-15

As input to a winter use plan, activity, fuel use, and tailpipe exhaust emissions of over snow vehicles (OSV), including five snow coaches and one snowmobile, were measured on a designated route in Yellowstone National Park (YNP). Engine load was quantified in terms of vehicle specific power (VSP), which is a function of speed, acceleration, and road grade. Compared to highway vehicles, VSP for OSVs is more sensitive to rolling resistance and less sensitive to aerodynamic drag. Fuel use rates increased linearly (R2>0.96) with VSP. For gasoline-fueled OSVs, fuel-based emission rates of carbon monoxide (CO) and nitrogen oxides (NOx) typically increased with increasing fuel use rate, with some cases of very high CO emissions. For the diesel OSVs, which had selective catalytic reduction and diesel particulate filters, fuel-based NOx and particulate matter (PM) emission rates were not sensitive to fuel flow rate, and the emission controls were effective. Inter vehicle variability in cycle average fuel use and emissions rates for CO and NOx was substantial. However, there was relatively little inter-cycle variation in cycle average fuel use and emission rates when comparing driving cycles. Recommendations are made regarding how real-world OSV activity, fuel use, and emissions data can be improved.

An improved protocol for optical projection tomography imaging reveals lobular heterogeneities in pancreatic islet and β-cell mass distribution

PubMed Central

2011-01-01

Optical projection tomography (OPT) imaging is a powerful tool for three-dimensional imaging of gene and protein distribution patterns in biomedical specimens. We have previously demonstrated the possibility, by this technique, to extract information of the spatial and quantitative distribution of the islets of Langerhans in the intact mouse pancreas. In order to further increase the sensitivity of OPT imaging for this type of assessment, we have developed a protocol implementing a computational statistical approach: contrast limited adaptive histogram equalization (CLAHE). We demonstrate that this protocol significantly increases the sensitivity of OPT imaging for islet detection, helps preserve islet morphology and diminish subjectivity in thresholding for tomographic reconstruction. When applied to studies of the pancreas from healthy C57BL/6 mice, our data reveal that, at least in this strain, the pancreas harbors substantially more islets than has previously been reported. Further, we provide evidence that the gastric, duodenal and splenic lobes of the pancreas display dramatic differences in total and relative islet and β-cell mass distribution. This includes a 75% higher islet density in the gastric lobe as compared to the splenic lobe and a higher relative volume of insulin producing cells in the duodenal lobe as compared to the other lobes. Altogether, our data show that CLAHE substantially improves OPT based assessments of the islets of Langerhans and that lobular origin must be taken into careful consideration in quantitative and spatial assessments of the pancreas. PMID:21633198

Brief Exposures to the Taste of Ethanol (EtOH) and Quinine Promote Subsequent Acceptance of EtOH in a Paradigm that Minimizes Postingestive Consequences.

PubMed

Loney, Gregory C; Meyer, Paul J

2018-03-01

Aversion to the orosensory properties of concentrated ethanol (EtOH) solutions is often cited as a primary barrier to initiation of drinking and may contribute to abstention. These aversive properties include gustatory processes which encompass both bitter-like taste qualities and trigeminal-mediated irritation. Chronic intermittent EtOH access (CIA) results in substantial and persistent increases in EtOH consumption, but the degree to which this facilitation involves sensory responding to EtOH and other bitter stimuli is currently undetermined. Long-Evans rats were given brief-access licking tests designed to examine the immediate, taste-guided assessment of the palatability of EtOH and quinine solutions. Rats were assessed once in a naïve state and again following previous brief-access exposure, or following 4 weeks of CIA. The relationship between the sensitivity to the aversive orosensory properties of EtOH and quinine following EtOH access and the impact of antecedent quinine exposure on the acceptance of EtOH were determined in 2 parallel studies. Both brief access to EtOH and 4-week CIA resulted in substantial rightward shifts in the concentration-response function of brief-access EtOH licking, indicating that EtOH exposure increased acceptance of the taste of EtOH. The initial sensitivity to the aversive orosensory properties of EtOH and quinine was positively correlated in naïve rats, such that rats that were initially more accepting of quinine were also more accepting of EtOH. Rats that sampled quinine immediately prior to tasting EtOH exhibited successive positive contrast in that they were more accepting of highly concentrated EtOH, relative to a water-control group. Increased EtOH acceptance following exposure is, at least in part, facilitated by a decrease in its aversive sensory properties. Both long- and short-term access increase the palatability of the taste of EtOH in brief-access licking tests. Moreover, the sensitivity to the bitterness of quinine was predictive of acceptance of EtOH indicating some commonality in the sensory mechanisms that mediate the initial acceptance of the 2 stimuli. Accordingly, immediate prior exposure to quinine results in increased acceptance of EtOH, suggesting that successive positive contrast between oral stimuli may contribute to increased alcohol consumption. Copyright © 2017 by the Research Society on Alcoholism.

Refinement of a Brief Anxiety Sensitivity Reduction Intervention

ERIC Educational Resources Information Center

Keough, Meghan E.; Schmidt, Norman B.

2012-01-01

Objective: Anxiety disorders are the most prevalent psychiatric disorders in the United States and result in substantial burden to the individual and society. Although effective treatments for anxiety disorders have been developed, there has been substantially less focus on interventions aimed at the amelioration of anxiety-related risk and…

Inhibitor of Nicotinamide Phosphoribosyltransferase Sensitizes Glioblastoma Cells to Temozolomide via Activating ROS/JNK Signaling Pathway.

PubMed

Feng, Jun; Yan, Peng-Fei; Zhao, Hong-Yang; Zhang, Fang-Cheng; Zhao, Wo-Hua; Feng, Min

2016-01-01

Overcoming temozolomide (TMZ) resistance is a great challenge in glioblastoma (GBM) treatment. Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme in the biosynthesis of nicotinamide adenine dinucleotide and has a crucial role in cancer cell metabolism. In this study, we investigated whether FK866 and CHS828, two specific NAMPT inhibitors, could sensitize GBM cells to TMZ. Low doses of FK866 and CHS828 (5 nM and 10 nM, resp.) alone did not significantly decrease cell viability in U251-MG and T98 GBM cells. However, they significantly increased the antitumor action of TMZ in these cells. In U251-MG cells, administration of NAMPT inhibitors increased the TMZ (100  μ M)-induced apoptosis and LDH release from GBM cells. NAMPT inhibitors remarkably enhanced the activities of caspase-1, caspase-3, and caspase-9. Moreover, NAMPT inhibitors increased reactive oxygen species (ROS) production and superoxide anion level but reduced the SOD activity and total antioxidative capacity in GBM cells. Treatment of NAMPT inhibitors increased phosphorylation of c-Jun and JNK. Administration of JNK inhibitor SP600125 or ROS scavenger tocopherol with TMZ and NAMPT inhibitors substantially attenuated the sensitization of NAMPT inhibitor on TMZ antitumor action. Our data indicate a potential value of NAMPT inhibitors in combined use with TMZ for GBM treatment.

Sensitivity of UV Erythemal Radiation to Total Ozone Changes under Different Sky Conditions: Results for Granada, Spain.

PubMed

Antón, Manuel; Cazorla, Alberto; Mateos, David; Costa, Maria J; Olmo, Francisco J; Alados-Arboledas, Lucas

2016-01-01

This study focuses on the analysis of the sensitivity of UV erythemal radiation (UVER) to variations in the total ozone column (TOC) under different sky conditions at Granada (southeastern Spain). The sensitivity is studied both in relative terms by means of the Radiation Amplification Factor (RAF) and in absolute terms using the Ozone Efficiency (OE). These two variables are determined for diverse sky conditions characterized by the cloud cover information given by a sky camera (in oktas) and the cloud optical depth (COD) estimated from global solar radiation measurements. As expected, in absolute terms, the TOC variations cause substantially smaller UVER changes during completely overcast situations than during cloud-free cases. For instance, the OE (SZA = 30°, TOC = 290 DU) decreases from 0.68 mW m(-2) per unit of TOC (0 oktas) to 0.50 mW m(-2) per unit of TOC (8 oktas). However, the opposite is observed when the analysis is performed in relative terms. Thus, the RAF (determined for SZA cases below 80°) increases from 1.1 for cloud-free cases (0 oktas) to 1.4 for completely overcast situations (8 oktas). This opposite behavior is also found when both RAF and OE are analyzed as functions of COD. Thus, while the OE strongly decreases with increasing COD, the RAF increases as COD increases. © 2015 The American Society of Photobiology.

Characterization of constitutive and acid-induced outwardly rectifying chloride currents in immortalized mouse distal tubular cells.

PubMed

Valinsky, William C; Touyz, Rhian M; Shrier, Alvin

2017-08-01

Thiazides block Na + reabsorption while enhancing Ca 2+ reabsorption in the kidney. As previously demonstrated in immortalized mouse distal convoluted tubule (MDCT) cells, chlorothiazide application induced a robust plasma membrane hyperpolarization, which increased Ca 2+ uptake. This essential thiazide-induced hyperpolarization was prevented by the Cl - channel inhibitor 5-Nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), implicating NPPB-sensitive Cl - channels, however the nature of these Cl - channels has been rarely described in the literature. Here we show that MDCT cells express a dominant, outwardly rectifying Cl - current at extracellular pH7.4. This constitutive Cl - current was more permeable to larger anions (Eisenman sequence I; I - >Br - ≥Cl - ) and was substantially inhibited by >100mM [Ca 2+ ] o , which distinguished it from ClC-K2/barttin. Moreover, the constitutive Cl - current was blocked by NPPB, along with other Cl - channel inhibitors (4,4'-diisothiocyanatostilbene-2,2'-disulfonate, DIDS; flufenamic acid, FFA). Subjecting the MDCT cells to an acidic extracellular solution (pH<5.5) induced a substantially larger outwardly rectifying NPPB-sensitive Cl - current. This acid-induced Cl - current was also anion permeable (I - >Br - >Cl - ), but was distinguished from the constitutive Cl - current by its rectification characteristics, ion sensitivities, and response to FFA. In addition, we have identified similar outwardly rectifying and acid-sensitive currents in immortalized cells from the inner medullary collecting duct (mIMCD-3 cells). Expression of an acid-induced Cl - current would be particularly relevant in the acidic IMCD (pH<5.5). To our knowledge, the properties of these Cl - currents are unique and provide the mechanisms to account for the Cl - efflux previously speculated to be present in MDCT cells. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Frontal, Striatal, and Medial Temporal Sensitivity to Value Distinguishes Risk-Taking from Risk-Aversive Older Adults during Decision Making.

PubMed

Goh, Joshua O S; Su, Yu-Shiang; Tang, Yong-Jheng; McCarrey, Anna C; Tereshchenko, Alexander; Elkins, Wendy; Resnick, Susan M

2016-12-07

Aging compromises the frontal, striatal, and medial temporal areas of the reward system, impeding accurate value representation and feedback processing critical for decision making. However, substantial variability characterizes age-related effects on the brain so that some older individuals evince clear neurocognitive declines whereas others are spared. Moreover, the functional correlates of normative individual differences in older-adult value-based decision making remain unclear. We performed a functional magnetic resonance imaging study in 173 human older adults during a lottery choice task in which costly to more desirable stakes were depicted using low to high expected values (EVs) of points. Across trials that varied in EVs, participants decided to accept or decline the offered stakes to maximize total accumulated points. We found that greater age was associated with less optimal decisions, accepting stakes when losses were likely and declining stakes when gains were likely, and was associated with increased frontal activity for costlier stakes. Critically, risk preferences varied substantially across older adults and neural sensitivity to EVs in the frontal, striatal, and medial temporal areas dissociated risk-aversive from risk-taking individuals. Specifically, risk-averters increased neural responses to increasing EVs as stakes became more desirable, whereas risk-takers increased neural responses with decreasing EV as stakes became more costly. Risk preference also modulated striatal responses during feedback with risk-takers showing more positive responses to gains compared with risk-averters. Our findings highlight the frontal, striatal, and medial temporal areas as key neural loci in which individual differences differentially affect value-based decision-making ability in older adults. Frontal, striatal, and medial temporal functions implicated in value-based decision processing of rewards and costs undergo substantial age-related changes. However, age effects on brain function and cognition differ across individuals. How this normative variation relates to older-adult value-based decision making is unclear. We found that although the ability make optimal decisions declines with age, there is still much individual variability in how this deterioration occurs. Critically, whereas risk-averters showed increased neural activity to increasingly valuable stakes in frontal, striatal, and medial temporal areas, risk-takers instead increased activity as stakes became more costly. Such distinct functional decision-making processing in these brain regions across normative older adults may reflect individual differences in susceptibility to age-related brain changes associated with incipient cognitive impairment. Copyright © 2016 the authors 0270-6474/16/3612498-12$15.00/0.

A community change in the algal endosymbionts of a scleractinian coral following a natural bleaching event: field evidence of acclimatization.

PubMed

Jones, A M; Berkelmans, R; van Oppen, M J H; Mieog, J C; Sinclair, W

2008-06-22

The symbiosis between reef-building corals and their algal endosymbionts (zooxanthellae of the genus Symbiodinium) is highly sensitive to temperature stress, which makes coral reefs vulnerable to climate change. Thermal tolerance in corals is known to be substantially linked to the type of zooxanthellae they harbour and, when multiple types are present, the relative abundance of types can be experimentally manipulated to increase the thermal limits of individual corals. Although the potential exists for this to translate into substantial thermal acclimatization of coral communities, to date there is no evidence to show that this takes place under natural conditions. In this study, we show field evidence of a dramatic change in the symbiont community of Acropora millepora, a common and widespread Indo-Pacific hard coral species, after a natural bleaching event in early 2006 in the Keppel Islands (Great Barrier Reef). Before bleaching, 93.5% (n=460) of the randomly sampled and tagged colonies predominantly harboured the thermally sensitive Symbiodinium type C2, while the remainder harboured a tolerant Symbiodinium type belonging to clade D or mixtures of C2 and D. After bleaching, 71% of the surviving tagged colonies that were initially C2 predominant changed to D or C1 predominance. Colonies that were originally C2 predominant suffered high mortality (37%) compared with D-predominant colonies (8%). We estimate that just over 18% of the original A. millepora population survived unchanged leaving 29% of the population C2 and 71% D or C1 predominant six months after the bleaching event. This change in the symbiont community structure, while it persists, is likely to have substantially increased the thermal tolerance of this coral population. Understanding the processes that underpin the temporal changes in symbiont communities is key to assessing the acclimatization potential of reef corals.

The human Nav1.5 F1486 deletion associated with long QT syndrome leads to impaired sodium channel inactivation and reduced lidocaine sensitivity

PubMed Central

Song, Weihua; Xiao, Yucheng; Chen, Hanying; Ashpole, Nicole M; Piekarz, Andrew D; Ma, Peilin; Hudmon, Andy; Cummins, Theodore R; Shou, Weinian

2012-01-01

The deletion of phenylalanine 1486 (F1486del) in the human cardiac voltage-gated sodium channel (hNav1.5) is associated with fatal long QT (LQT) syndrome. In this study we determined how F1486del impairs the functional properties of hNav1.5 and alters action potential firing in heterologous expression systems (human embryonic kidney (HEK) 293 cells) and their native cardiomyocyte background. Cells expressing hNav1.5-F1486del exhibited a loss-of-function alteration, reflected by an 80% reduction of peak current density, and several gain-of-function alterations, including reduced channel inactivation, enlarged window current, substantial augmentation of persistent late sodium current and an increase in ramp current. We also observed substantial action potential duration (APD) prolongation and prominent early afterdepolarizations (EADs) in neonatal cardiomyocytes expressing the F1486del channels, as well as in computer simulations of myocyte activity. In addition, lidocaine sensitivity was dramatically reduced, which probably contributed to the poor therapeutic outcome observed in the patient carrying the hNav1.5-F1486del mutation. Therefore, despite the significant reduction in peak current density, the F1486del mutation also leads to substantial gain-of-function alterations that are sufficient to cause APD prolongation and EADs, the predominant characteristic of LQTs. These data demonstrate that hNav1.5 mutations can have complex functional consequences and highlight the importance of identifying the specific molecular defect when evaluating potential treatments for individuals with prolonged QT intervals. PMID:22826127

Antacids and dietary supplements with an influence on the gastric pH increase the risk for food sensitization

PubMed Central

Pali-Schöll, I.; Herzog, R.; Wallmann, J.; Szalai, K.; Brunner, R.; Lukschal, A.; Karagiannis, P.; Diesner, S. C.; Jensen-Jarolim, E.

2010-01-01

Summary Background Elevation of the gastric pH increases the risk for sensitization against food allergens by hindering protein breakdown. This can be caused by acid-suppressing medication like sucralphate, H2-receptor blockers and proton pump inhibitors, as shown in recent murine experimental and human observational studies. Objective The aim of the present study was to assess the sensitization capacity of the dietary supplement base powder and of over-the-counter antacids. Methods Changes of the pH as well as of protein digestion due to base powder or antacids were measured in vitro. To examine the in vivo influence, BALB/c mice were fed codfish extract with one of the acid-suppressing substances. Read-out of antibody levels in the sera, of cytokine levels of stimulated splenocytes and of intradermal skin tests was performed. Results The pH of hydrochloric acid was substantially increased in vitro by base powder as well as antacids in a time- and dose-dependent manner. This elevation hindered the digestion of codfish proteins in vitro. A significant increase in codfish-specific IgE antibodies was found in the groups fed codfish combined with Rennie® Antacidum or with base powder; the latter also showed significantly elevated IgG1 and IgG2a levels. The induction of an anaphylactic immune response was proven by positive results in intradermal skin tests. Conclusions Antacids and dietary supplements influencing the gastric pH increase the risk for sensitization against allergenic food proteins. As these substances are commonly used in the general population without consulting a physician, our data may have a major practical and clinical impact. PMID:20214670

Variability in larval gut pH regulation defines sensitivity to ocean acidification in six species of the Ambulacraria superphylum.

PubMed

Hu, Marian; Tseng, Yung-Che; Su, Yi-Hsien; Lein, Etienne; Lee, Hae-Gyeong; Lee, Jay-Ron; Dupont, Sam; Stumpp, Meike

2017-10-11

The unusual rate and extent of environmental changes due to human activities may exceed the capacity of marine organisms to deal with this phenomenon. The identification of physiological systems that set the tolerance limits and their potential for phenotypic buffering in the most vulnerable ontogenetic stages become increasingly important to make large-scale projections. Here, we demonstrate that the differential sensitivity of non-calcifying Ambulacraria (echinoderms and hemichordates) larvae towards simulated ocean acidification is dictated by the physiology of their digestive systems. Gastric pH regulation upon experimental ocean acidification was compared in six species of the superphylum Ambulacraria. We observed a strong correlation between sensitivity to ocean acidification and the ability to regulate gut pH. Surprisingly, species with tightly regulated gastric pH were more sensitive to ocean acidification. This study provides evidence that strict maintenance of highly alkaline conditions in the larval gut of Ambulacraria early life stages may dictate their sensitivity to decreases in seawater pH. These findings highlight the importance of identifying and understanding pH regulatory systems in marine larval stages that may contribute to substantial energetic challenges under near-future ocean acidification scenarios. © 2017 The Author(s).

Skin sensitizer identification by IL-8 secretion and CD86 expression on THP-1 cells.

PubMed

Parise, Carolina Bellini; Sá-Rocha, Vanessa Moura; Moraes, Jane Zveiter

2015-12-25

Substantial progress has been made in the development of alternative methods for skin sensitization in the last decade in several countries around the world. Brazil is experiencing an increasing concern about using animals for product development, since the publication of the Law 9605/1998, which prohibits the use of animals when an alternative method is available. In this way, an in vitro test to evaluate allergenic potential is a pressing need.This preliminary study started setting the use of myelomonocytic THP-1 cell line, according to the human cell line activation test (h-CLAT), already under validation process. We found that 48-h chemical exposure was necessary to identify 22 out of 23 sensitizers by the analyses of CD86 expression. In addition, the CD54 expression analyses presented a poor efficiency to discriminate sensitizers from non-sensitizers in our conditions. In view of these results, we looked for changes of pro-inflammatory interleukin profile. The IL-8 secretion analyses after 24-h chemical incubation seemed to be an alternative for CD54 expression assessing.Altogether, our findings showed that the combination of the analyses of CD86 expression and IL-8 secretion allowed predicting allergenicity.

Assessing societal vulnerability of U.S. Pacific Northwest communities to storm-induced coastal change

USGS Publications Warehouse

Baron, Heather M.; Wood, Nathan J.; Ruggerio, Peter; Allan, Jonathan; Corcoran, Patrick

2010-01-01

Progressive increases in storm intensities and extreme wave heights have been documented along the U.S. West Coast. Paired with global sea level rise and the potential for an increase in El Niño occurrences, these trends have substantial implications for the vulnerability of coastal communities to natural coastal hazards. Community vulnerability to hazards is characterized by the exposure, sensitivity, and adaptive capacity of human-environmental systems that influence potential impacts. To demonstrate how societal vulnerability to coastal hazards varies with both physical and social factors, we compared community exposure and sensitivity to storm-induced coastal change scenarios in Tillamook (Oregon) and Pacific (Washington) Counties. While both are backed by low-lying coastal dunes, communities in these two counties have experienced different shoreline change histories and have chosen to use the adjacent land in different ways. Therefore, community vulnerability varies significantly between the two counties. Identifying the reasons for this variability can help land-use managers make decisions to increase community resilience and reduce vulnerability in spite of a changing climate.

Double-gated Si NW FET sensors: Low-frequency noise and photoelectric properties

NASA Astrophysics Data System (ADS)

Gasparyan, F.; Khondkaryan, H.; Arakelyan, A.; Zadorozhnyi, I.; Pud, S.; Vitusevich, S.

2016-08-01

The transport, noise, and photosensitivity properties of an array of silicon nanowire (NW) p+-p-p+ field-effect transistors (FETs) are investigated. The peculiarities of photosensitivity and detectivity are analyzed over a wide spectrum range. The absorbance of p-Si NW shifts to the short wavelength region compared with bulk Si. The photocurrent and photosensitivity reach increased values in the UV range of the spectrum at 300 K. It is shown that sensitivity values can be tuned by the drain-source voltage and may reach record values of up to 2-4 A/W at a wavelength of 300 nm at room temperature. Low-frequency noise studies allow calculating the photodetectivity values, which increase with decreasing wavelength down to 300 nm. We show that the drain current of Si NW biochemical sensors substantially depends on pH value and the signal-to-noise ratio reaches the high value of 105. Increasing pH sensitivity with gate voltage is revealed for certain source-drain currents of pH-sensors based on Si NW FETs. The noise characteristic index decreases from 1.1 to 0.7 with the growth of the liquid gate voltage. Noise behavior is successfully explained in the framework of the correlated number-mobility unified fluctuation model. pH sensitivity increases as a result of the increase in liquid gate voltage, thus giving the opportunity to measure very low proton concentrations in the electrolyte medium at certain values of the liquid gate voltage.

Reactivating p53 and Inducing Tumor Apoptosis (RITA) Enhances the Response of RITA-Sensitive Colorectal Cancer Cells to Chemotherapeutic Agents 5-Fluorouracil and Oxaliplatin.

PubMed

Wiegering, Armin; Matthes, Niels; Mühling, Bettina; Koospal, Monika; Quenzer, Anne; Peter, Stephanie; Germer, Christoph-Thomas; Linnebacher, Michael; Otto, Christoph

2017-04-01

Colorectal carcinoma (CRC) is the most common cancer of the gastrointestinal tract with frequently dysregulated intracellular signaling pathways, including p53 signaling. The mainstay of chemotherapy treatment of CRC is 5-fluorouracil (5FU) and oxaliplatin. The two anticancer drugs mediate their therapeutic effect via DNA damage-triggered signaling. The small molecule reactivating p53 and inducing tumor apoptosis (RITA) is described as an activator of wild-type and reactivator of mutant p53 function, resulting in elevated levels of p53 protein, cell growth arrest, and cell death. Additionally, it has been shown that RITA can induce DNA damage signaling. It is expected that the therapeutic benefits of 5FU and oxaliplatin can be increased by enhancing DNA damage signaling pathways. Therefore, we highlighted the antiproliferative response of RITA alone and in combination with 5FU or oxaliplatin in human CRC cells. A panel of long-term established CRC cell lines (n=9) including p53 wild-type, p53 mutant, and p53 null and primary patient-derived, low-passage cell lines (n=5) with different p53 protein status were used for this study. A substantial number of CRC cells with pronounced sensitivity to RITA (IC 50 <3.0 μmol/l) were identified within established (4/9) and primary patient-derived (2/5) CRC cell lines harboring wild-type or mutant p53 protein. Sensitivity to RITA appeared independent of p53 status and was associated with an increase in antiproliferative response to 5FU and oxaliplatin, a transcriptional increase of p53 targets p21 and NOXA, and a decrease in MYC mRNA. The effect of RITA as an inducer of DNA damage was shown by a strong elevation of phosphorylated histone variant H2A.X, which was restricted to RITA-sensitive cells. Our data underline the primary effect of RITA, inducing DNA damage, and demonstrate the differential antiproliferative effect of RITA to CRC cells independent of p53 protein status. We found a substantial number of RITA-sensitive CRC cells within both panels of established CRC cell lines and primary patient-derived CRC cell lines (6/14) that provide a rationale for combining RITA with 5FU or oxaliplatin to enhance the antiproliferative response to both chemotherapeutic agents. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

VARIABILITY OF VISUAL FIELD MEASUREMENTS IS CORRELATED WITH THE GRADIENT OF VISUAL SENSITIVITY

PubMed Central

Wyatt, Harry J.; Dul, Mitchell W.; Swanson, William H.

2007-01-01

Conventional static automated perimetry provides important clinical information, but its utility is limited by considerable test-retest variability. Fixational eye movements during testing could contribute to variability. To assess this possibility, it is important to know how much sensitivity change would be caused by a given eye movement. To investigate this, we have evaluated the gradient, the rate at which sensitivity changes with location. We tested one eye each, twice within 3 weeks, of 29 patients with glaucoma, 17 young normal subjects and 13 older normal subjects. The 10-2 test pattern with the SITA Standard algorithm was used to assess sensitivity at locations with 2° spacing. Variability and gradient were calculated at individual test locations. Matrix correlations were determined between variability and gradient, and were substantial for the patients with glaucoma. The results were consistent with a substantial contribution to test-retest variability from small fixational eye movements interacting with visual field gradient. Successful characterization of the gradient of sensitivity appears to require sampling at relatively close spacing, as in the 10-2 test pattern. PMID:17320924

Variability of visual field measurements is correlated with the gradient of visual sensitivity.

PubMed

Wyatt, Harry J; Dul, Mitchell W; Swanson, William H

2007-03-01

Conventional static automated perimetry provides important clinical information, but its utility is limited by considerable test-retest variability. Fixational eye movements during testing could contribute to variability. To assess this possibility, it is important to know how much sensitivity change would be caused by a given eye movement. To investigate this, we have evaluated the gradient, the rate at which sensitivity changes with location. We tested one eye each, twice within 3 weeks, of 29 patients with glaucoma, 17 young normal subjects and 13 older normal subjects. The 10-2 test pattern with the SITA Standard algorithm was used to assess sensitivity at locations with 2 degrees spacing. Variability and gradient were calculated at individual test locations. Matrix correlations were determined between variability and gradient, and were substantial for the patients with glaucoma. The results were consistent with a substantial contribution to test-retest variability from small fixational eye movements interacting with visual field gradient. Successful characterization of the gradient of sensitivity appears to require sampling at relatively close spacing, as in the 10-2 test pattern.

Interplay between structure, stoichiometry, and electron transfer dynamics in SILAR-based quantum dot-sensitized oxides.

PubMed

Wang, Hai; Barceló, Irene; Lana-Villarreal, Teresa; Gómez, Roberto; Bonn, Mischa; Cánovas, Enrique

2014-10-08

We quantify the rate and efficiency of picosecond electron transfer (ET) from PbS nanocrystals, grown by successive ionic layer adsorption and reaction (SILAR), into a mesoporous SnO2 support. Successive SILAR deposition steps allow for stoichiometry- and size-variation of the QDs, characterized using transmission electron microscopy. Whereas for sulfur-rich (p-type) QD surfaces substantial electron trapping at the QD surface occurs, for lead-rich (n-type) QD surfaces, the QD trapping channel is suppressed and the ET efficiency is boosted. The ET efficiency increase achieved by lead-rich QD surfaces is found to be QD-size dependent, increasing linearly with QD surface area. On the other hand, ET rates are found to be independent of both QD size and surface stoichiometry, suggesting that the donor-acceptor energetics (constituting the driving force for ET) are fixed due to Fermi level pinning at the QD/oxide interface. Implications of our results for QD-sensitized solar cell design are discussed.

Exploring Pacific Climate Variability and Its Impacts on East African Water Resources and Food Security

NASA Astrophysics Data System (ADS)

Funk, C. C.; Hoerling, M. P.; Hoell, A.; Liebmann, B.; Verdin, J. P.; Eilerts, G.

2014-12-01

In 8 out the past 15 boreal springs (1999, 2000, 2004, 2008, 2009, 2011, 2012, and 2013), substantial parts of eastern East Africa experienced very low boreal spring rains. These rainfall deficits have triggered widespread food insecurity, and even contributed to the outbreak of famine conditions in Somalia in 2011. At both seasonal and decadal time scales, new science supported by the USAID Famine Early Warning Systems Network seeks to understand the mechanisms producing these droughts. We present research suggesting that the ultimate and proximate causes of these increases in aridity are i) stronger equatorial Pacific SST gradients and ii) associated increases in the strength of the Indo-Pacific Walker circulation. Using observations and new modeling ensembles, we explore the relative contributions of Pacific Decadal Variability (PDV) and global warming under warm and cold east Pacific Ocean states. This question is addressed in two ways: by using atmospheric GCMs forced with full and ENSO-only SSTs, and ii) by decomposing coupled ocean-atmosphere climate simulations into PDV and non-PDV components. These analyses allow us to explore the Walker circulation's sensitivity to climate change under various PDV states, and inform a tentative bracketing of 2030 climate conditions. We conclude by discussing links to East African development. Regions of high rainfall sensitivity are delineated and intersected with recent changes in population and land cover/land use. The interaction of elevation and climate is shown to create climatically secure regions that are likely to remain viable even under drier and warmer conditions; such regions may be logical targets for agricultural intensification. Conversely, arid low elevation regions are likely to experience substantial temperature impacts. Continued expansion into these areas may effectively create more 'drought' even if rainfall increases.

Partitioning the Water Budget in a Glacierized Basin

NASA Astrophysics Data System (ADS)

O'Neel, S.; Sass, L.; McGrath, D.; McNeil, C.; Myers, K. F.; Bergstrom, A.; Koch, J. C.; Ostman, J. S.; Arendt, A. A.; LeWinter, A.; Larsen, C. F.; Marshall, H. P.

2017-12-01

Glaciers couple to the ecosystems in which they reside through their mass balance and subsequent runoff. The unique timing and composition of glacier runoff notably impacts ecological and socio-economically important processes, including thermal modulation of streams, nearshore primary production, and groundwater exchange. Predicting how these linkages will evolve as glaciers continue to retreat requires a better understanding of basin- to region-scale water budgets. Here we develop a partitioned water balance for Alaska's Wolverine Glacier basin for 2016. Our presentation will highlight mass-balance forcing and sensitivity, as well as analyses of hydrometric and geochemical partitioning. These observations provide constraints for hypsometry-based regional projections of glacier change, which form the basis of future biogeochemical scenarios. Local climate records show relatively minor warming and drying over the 1967 -2016 interval, yet the impact on the glacier was substantial; the average annual balance rate over the study interval is -0.5 m/yr. We performed a sensitivity experiment that suggests that elevation-independent processes drive first-order variability in glacier-wide mass balance solutions Analysis of runoff and precipitation data suggest that previously ignored components of the hydrologic cycle (groundwater, evapotranspiration, off-glacier snowpack storage, and snow redistribution) may substantially contribute to the basin wide water budget. Initial geochemical assessments (carbon, water isotopes, major ions) highlight unique source signatures (glacier-derived, snow-melt, groundwater), which will be further explored using a mixing model approach. Applying a range of climate forcings over centennial time-scales suggests the regional equilibrium line altitude is likely to increase by more than 100 m, which will result in extensive glacier area losses. Such changes will likely modify the runoff from this basin by increasing inter-annual streamflow variability and increasing the fraction of runoff delivered early in the melt season.

Effects of mycoplasma contamination on phenotypic expression of mitochondrial mutants in human cells.

PubMed

Doersen, C J; Stanbridge, E J

1981-04-01

HeLa cells sensitive to the mitochondrial protein synthesis inhibitors erythromycin (ERY) and chloramphenicol (CAP) and HeLa variants resistant to the effects of these drugs were purposefully infected with drug-sensitive and -resistant mycoplasma strains. Mycoplasma hyorhinis and the ERY-resistant strain of Mycoplasma orale, MO-ERYr, did not influence the growth of HeLa and ERY-resistant ERY2301 cells in the presence or absence of ERY. M. hyorhinis also did not affect the growth of HeLa and CAP-resistant Cap-2 cells in the presence or absence of CAP. However, both HeLa and Cap-2 cells infected with the CAP-resistant strain of M. hyorhinis, MH-CAPr, were more sensitive to the cytotoxic effect of CAP. This may be due to the glucose dependence of the cells, which was compromised by the increased utilization of glucose by MH-CAPr in these infected cell cultures. In vitro protein synthesis by isolated mitochondria was significantly altered by mycoplasma infection of the various cell lines. A substantial number of mycoplasmas copurified with the mitochondria, resulting in up to a sevenfold increase in the incorporation of [3H]leucine into the trichloroacetic acid-insoluble material. More importantly, the apparent drug sensitivity or resistance of mitochondrial preparations from mycoplasma-infected cells reflected the drug sensitivity or resistance of the contaminating mycoplasmas. These results illustrate the hazards in interpreting mitochondrial protein synthesis data derived from mycoplasma-infected cell lines, particularly putative mitochondrially encoded mutants resistant to inhibitors of mitochondrial protein synthesis.

Multistrip Western blotting: a tool for comparative quantitative analysis of multiple proteins.

PubMed

Aksamitiene, Edita; Hoek, Jan B; Kiyatkin, Anatoly

2015-01-01

The qualitative and quantitative measurements of protein abundance and modification states are essential in understanding their functions in diverse cellular processes. Typical Western blotting, though sensitive, is prone to produce substantial errors and is not readily adapted to high-throughput technologies. Multistrip Western blotting is a modified immunoblotting procedure based on simultaneous electrophoretic transfer of proteins from multiple strips of polyacrylamide gels to a single membrane sheet. In comparison with the conventional technique, Multistrip Western blotting increases data output per single blotting cycle up to tenfold; allows concurrent measurement of up to nine different total and/or posttranslationally modified protein expression obtained from the same loading of the sample; and substantially improves the data accuracy by reducing immunoblotting-derived signal errors. This approach enables statistically reliable comparison of different or repeated sets of data and therefore is advantageous to apply in biomedical diagnostics, systems biology, and cell signaling research.

Development of a sensitive GC-C-IRMS method for the analysis of androgens.

PubMed

Polet, Michael; Van Gansbeke, Wim; Deventer, Koen; Van Eenoo, Peter

2013-02-01

The administration of anabolic steroids is one of the most important issues in doping control and is detectable through a change in the carbon isotopic composition of testosterone and/or its metabolites. Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS), however, remains a very laborious and expensive technique and substantial amounts of urine are needed to meet the sensitivity requirements of the IRMS. This can be problematic because only a limited amount of urine is available for anti-doping analysis on a broad spectrum of substances. In this work we introduce a new type of injection that increases the sensitivity of GC-C-IRMS by a factor of 13 and reduces the limit of detection, simply by using solvent vent injections instead of splitless injection. This drastically reduces the amount of urine required. On top of that, by only changing the injection technique, the detection parameters of the IRMS are not affected and there is no loss in linearity. Copyright © 2012 John Wiley & Sons, Ltd.

First application of calorimetric low-temperature detectors in accelerator mass spectrometry

NASA Astrophysics Data System (ADS)

Kraft, S.; Andrianov, V.; Bleile, A.; Egelhof, P.; Golser, R.; Kiseleva, A.; Kiselev, O.; Kutschera, W.; Meier, J. P.; Priller, A.; Shrivastava, A.; Steier, P.; Vockenhuber, C.

2004-03-01

For the first time, calorimetric low-temperature detectors were applied in accelerator mass spectrometry, a well-known method for determination of very small isotope ratios with high sensitivity. The aim of the experiment was to determine with high accuracy the isotope ratio of 236U/238U for several samples of natural uranium, 236U being known as a sensitive monitor for neutron flux. Measurements were performed at the VERA tandem accelerator at Vienna, Austria. The detectors consist of sapphire absorbers and superconducting transition edge thermometers operated at T≈ 1.5 K. The relative energy resolution obtained for 17.39 MeV 238U is ΔE/E=4-9×10-3, depending on the experimental conditions. This performance enabled to substantially reduce background from neighbouring isotopes and to increase the detection efficiency. Due to the high sensitivity achieved, a value of 236U/238U=6.5×10-12 could be obtained, representing the smallest 236U/238U ratio measured until now.

Optimization Issues with Complex Rotorcraft Comprehensive Analysis

NASA Technical Reports Server (NTRS)

Walsh, Joanne L.; Young, Katherine C.; Tarzanin, Frank J.; Hirsh, Joel E.; Young, Darrell K.

1998-01-01

This paper investigates the use of the general purpose automatic differentiation (AD) tool called Automatic Differentiation of FORTRAN (ADIFOR) as a means of generating sensitivity derivatives for use in Boeing Helicopter's proprietary comprehensive rotor analysis code (VII). ADIFOR transforms an existing computer program into a new program that performs a sensitivity analysis in addition to the original analysis. In this study both the pros (exact derivatives, no step-size problems) and cons (more CPU, more memory) of ADIFOR are discussed. The size (based on the number of lines) of the VII code after ADIFOR processing increased by 70 percent and resulted in substantial computer memory requirements at execution. The ADIFOR derivatives took about 75 percent longer to compute than the finite-difference derivatives. However, the ADIFOR derivatives are exact and are not functions of step-size. The VII sensitivity derivatives generated by ADIFOR are compared with finite-difference derivatives. The ADIFOR and finite-difference derivatives are used in three optimization schemes to solve a low vibration rotor design problem.

Modelling the sensitivity of soil mercury storage to climate-induced changes in soil carbon pools

NASA Astrophysics Data System (ADS)

Hararuk, O.; Obrist, D.; Luo, Y.

2013-04-01

Substantial amounts of mercury (Hg) in the terrestrial environment reside in soils and are associated with soil organic carbon (C) pools, where they accumulated due to increased atmospheric deposition resulting from anthropogenic activities. The purpose of this study was to examine potential sensitivity of surface soil Hg pools to global change variables, particularly affected by predicted changes in soil C pools, in the contiguous US. To investigate, we included a soil Hg component in the Community Land Model based on empirical statistical relationships between soil Hg / C ratios and precipitation, latitude, and clay; and subsequently explored the sensitivity of soil C and soil Hg densities (i.e., areal-mass) to climate scenarios in which we altered annual precipitation, carbon dioxide (CO2) concentrations and temperature. Our model simulations showed that current sequestration of Hg in the contiguous US accounted for 15 230 metric tons of Hg in the top 0-40 cm of soils, or for over 300 000 metric tons when extrapolated globally. In the simulations, US soil Hg pools were most sensitive to changes in precipitation because of strong effects on soil C pools, plus a direct effect of precipitation on soil Hg / C ratios. Soil Hg pools were predicted to increase beyond present-day values following an increase in precipitation amounts and decrease following a reduction in precipitation. We found pronounced regional differences in sensitivity of soil Hg to precipitation, which were particularly high along high-precipitation areas along the West and East Coasts. Modelled increases in CO2 concentrations to 700 ppm stimulated soil C and Hg accrual, while increased air temperatures had small negative effects on soil C and Hg densities. The combined effects of increased CO2, increased temperature and increased or decreased precipitation were strongly governed by precipitation and CO2 showing pronounced regional patterns. Based on these results, we conclude that the combination of precipitation and CO2 should be emphasised when assessing how climate-induced changes in soil C may affect sequestration of Hg in soils.

Caffeic Acid Phenethyl Ester Regulates PPAR's Levels in Stem Cells-Derived Adipocytes

PubMed Central

Vanella, Luca; Tibullo, Daniele; Godos, Justyna; Pluchinotta, Francesca Romana; Di Giacomo, Claudia; Sorrenti, Valeria; Acquaviva, Rosaria; Russo, Alessandra; Li Volti, Giovanni; Barbagallo, Ignazio

2016-01-01

Hypertrophic obesity inhibits activation of peroxisome proliferators-activated receptor gamma (PPARγ), considered the key mediator of the fully differentiated and insulin sensitive adipocyte phenotype. We examined the effects of Caffeic Acid Phenethyl Ester (Cape), isolated from propolis, a honeybee hive product, on Adipose Stem Cells (ASCs) differentiation to the adipocyte lineage. Finally we tested the effects of Cape on insulin-resistant adipocytes. Quantification of Oil Red O-stained cells showed that lipid droplets decreased following Cape treatment as well as radical oxygen species formation. Additionally, exposure of ASC to high glucose levels decreased adiponectin and increased proinflammatory cytokines mRNA levels, which were reversed by Cape-mediated increase of insulin sensitivity. Cape treatment resulted in decreased triglycerides synthesis and increased beta-oxidation. Exposure of ASCs to Lipopolysaccharide (LPS) induced a reduction of PPARγ, an increase of IL-6 levels associated with a well-known stimulation of lipolysis; Cape partially attenuated the LPS-mediated effects. These observations reveal the main role of PPARγ in the adipocyte function and during ASC differentiation. As there is now substantial interest in functional food and nutraceutical products, the observed therapeutic value of Cape in insulin-resistance related diseases should be taken into consideration. PMID:26904104

Size-exclusion chromatography for the determination of the boiling point distribution of high-boiling petroleum fractions.

PubMed

Boczkaj, Grzegorz; Przyjazny, Andrzej; Kamiński, Marian

2015-03-01

The paper describes a new procedure for the determination of boiling point distribution of high-boiling petroleum fractions using size-exclusion chromatography with refractive index detection. Thus far, the determination of boiling range distribution by chromatography has been accomplished using simulated distillation with gas chromatography with flame ionization detection. This study revealed that in spite of substantial differences in the separation mechanism and the detection mode, the size-exclusion chromatography technique yields similar results for the determination of boiling point distribution compared with simulated distillation and novel empty column gas chromatography. The developed procedure using size-exclusion chromatography has a substantial applicability, especially for the determination of exact final boiling point values for high-boiling mixtures, for which a standard high-temperature simulated distillation would have to be used. In this case, the precision of final boiling point determination is low due to the high final temperatures of the gas chromatograph oven and an insufficient thermal stability of both the gas chromatography stationary phase and the sample. Additionally, the use of high-performance liquid chromatography detectors more sensitive than refractive index detection allows a lower detection limit for high-molar-mass aromatic compounds, and thus increases the sensitivity of final boiling point determination. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sensitivity of Ocean Chemistry and Oxygen Change to the Uncertainty in Climate Change

NASA Astrophysics Data System (ADS)

Cao, L.; Wang, S.; Zheng, M.; Zhang, H.

2014-12-01

With increasing atmospheric CO2 and climate change, global ocean is undergoing substantial physical and biogeochemical changes. In particular, changes in ocean oxygen and carbonate chemistry have great implication for marine biota. There is considerable uncertainty in the projections of future climate change, and it is unclear how the uncertainty in climate change would affect the projection of ocean oxygen and carbonate chemistry. To examine the effect of climate change on ocean oxygen and carbonate chemistry, we used an Earth system model of intermediate complexity to perform simulations that are driven by atmospheric CO2 concentration pathway of RCP 8.5 with climate sensitivity varying from 0.0°C to 4.5 °C. Climate change affects carbonate chemistry and oxygen mainly through its impact on ocean temperature, ocean ventilation, and concentration of dissolved inorganic carbon and alkalinity. Our simulations show that climate change mitigates the decrease of carbonate ions at the ocean surface but has negligible effect on surface ocean pH. Averaged over the whole ocean, climate change acts to decrease oxygen concentration but mitigates the CO2-induced reduction of carbonate ion and pH. In our simulations, by year 2500, every degree increase of climate sensitivity warms the ocean by 0.8 °C and reduces ocean-mean dissolved oxygen concentration by 5.0%. Meanwhile, every degree increase of climate sensitivity buffers CO2-induced reduction in ocean-mean carbonate ion concentration and pH by 3.4% and 0.02 units, respectively. Our study demonstrates different sensitivities of ocean temperature, carbonate chemistry, and oxygen, in terms of both the sign and magnitude, to the amount of climate change, which have great implications for understanding the response of ocean biota to climate change.

Patients with chronic tension-type headache demonstrate increased mechano-sensitivity of the supra-orbital nerve.

PubMed

Fernández-de-Las-Peñas, César; Coppieters, Michel W; Cuadrado, María Luz; Pareja, Juan A

2008-04-01

This study aimed to establish whether increased sensitivity to mechanical stimuli is present in neural tissues in chronic tension-type headache (CTTH). Muscle hyperalgesia is a common finding in CTTH. No previous studies have investigated the sensitivity of peripheral nerves in patients with CTTH. A blinded controlled study. Pressure pain thresholds (PPT) and pain intensity following palpation of the supra-orbital nerve (V1) were compared between 20 patients with CTTH and 20 healthy matched subjects. A pressure algometer and numerical pain rate scale were used to quantify PPT and pain to palpation. A headache diary was kept for 4 weeks to substantiate the diagnosis and record the pain history. The analysis of variance demonstrated significantly lower PPT for patients (0.86+/-0.13 kg/cm2) than controls (1.50+/-0.19 kg/cm2) (P<.001). Pain to palpation was also higher for patients (2.73+/-1.58) than controls (0.15+/-0.28) (P<.001). Within the CTTH group, intensity, frequency, and duration of the headaches were negatively correlated with PPT (rsor=0.72; P<.001). These findings reveal that mechanical hypersensitivity is not limited to muscles but also occurs in cranial nerves, and that the level of sensitization, either due to peripheral or central processes, is related to the severity of the primary headache.

SENSITIVITY OF ENDOSCOPIC ULTRASOUND, MULTIDETECTOR COMPUTER TOMOGRAPHY AND MAGNETIC RESONANCE CHOLANGIOPANCREATOGRAPHY IN THE DIAGNOSIS OF PANCREAS DIVISUM: A TERTIARY CENTER EXPERIENCE

PubMed Central

Kushnir, Vladimir M.; Wani, Sachin B.; Fowler, Kathryn; Menias, Christine; Varma, Rakesh; Narra, Vamsi; Hovis, Christine; Murad, Faris; Mullady, Daniel; Jonnalagadda, Sreenivasa S.; Early, Dayna S.; Edmundowicz, Steven A.; Azar, Riad R.

2014-01-01

OBJECTIVES There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: 1. Evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP) and multi-detector computed tomography (MDCT) for pancreas divisum. 2. Assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. METHODS For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography (ERP) who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent ERP and cross-sectional imaging. RESULTS The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) [p<0.001 for each]. On review by expert radiologists the sensitivity of MDCT increased to 83.3% in cases where the pancreatic duct was visualized, with fair IOA (қ=0.34). Expert review of MRCPs did not identify any additional cases of pancreas divisum; IOA was moderate (қ=0.43). CONCLUSIONS EUS is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum. PMID:23211370

Inflammatory cytokine biomarkers to identify women with asymptomatic sexually transmitted infections and bacterial vaginosis who are at high risk of HIV infection.

PubMed

Masson, Lindi; Arnold, Kelly B; Little, Francesca; Mlisana, Koleka; Lewis, David A; Mkhize, Nonhlanhla; Gamieldien, Hoyam; Ngcapu, Sinaye; Johnson, Leigh; Lauffenburger, Douglas A; Abdool Karim, Quarraisha; Abdool Karim, Salim S; Passmore, Jo-Ann S

2016-05-01

Untreated sexually transmitted infections (STIs) and bacterial vaginosis (BV) cause genital inflammation and increase the risk of HIV infection. WHO-recommended syndromic STI and BV management is severely limited as many women with asymptomatic infections go untreated. The purpose of this cross-sectional study was to evaluate genital cytokine profiles as a biomarker of STIs and BV to identify women with asymptomatic, treatable infections. Concentrations of 42 cytokines in cervicovaginal lavages from 227 HIV-uninfected women were measured using Luminex. All women were screened for BV by microscopy and STIs using molecular assays. Multivariate analyses were used to identify cytokine profiles associated with STIs/BV. A multivariate profile of seven cytokines (interleukin (IL)-1α, IL-1β, tumour necrosis factor-β, IL-4, fractalkine, macrophage-derived chemokine, and interferon-γ) most accurately predicted the presence of a treatable genital condition, with 77% classification accuracy and 75% cross-validation accuracy (sensitivity 72%; specificity 81%, positive predictive value (PPV) 86%, negative predictive value (NPV) 64%). Concomitant increased IL-1β and decreased IP-10 concentrations predicted the presence of a treatable genital condition without a substantial reduction in predictive value (sensitivity 77%, specificity 72%, PPV 82% and NPV 65%), correctly classifying 75% of the women. This approach performed substantially better than clinical signs (sensitivity 19%, specificity 92%, PPV 79% and NPV 40%). Supplementing syndromic management with an assessment of IL-1β and IP-10 as biomarkers of genital inflammation may improve STI/BV management for women, enabling more effective treatment of asymptomatic infections and potentially reducing their risk of HIV infection. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Salt Sensitivity and Hypertension: A Paradigm Shift from Kidney Malfunction to Vascular Endothelial Dysfunction

PubMed Central

Choi, Hoon Young; Park, Hyeong Cheon

2015-01-01

Hypertension is a complex trait determined by both genetic and environmental factors and is a major public health problem due to its high prevalence and concomitant increase in the risk for cardiovascular disease. With the recent large increase of dietary salt intake in most developed countries, the prevalence of hypertension increases tremendously which is about 30% of the world population. There is substantial evidence that suggests some people can effectively excrete high dietary salt intake without an increase in arterial BP, and another people cannot excrete effectively without an increase in arterial BP. Salt sensitivity of BP refers to the BP responses for changes in dietary salt intake to produce meaningful BP increases or decreases. The underlying mechanisms that promote salt sensitivity are complex and range from genetic to environmental influences. The phenotype of salt sensitivity is therefore heterogeneous with multiple mechanisms that potentially link high salt intake to increases in blood pressure. Moreover, excess salt intake has functional and pathological effects on the vasculature that are independent of blood pressure. Epidemiologic data demonstrate the role of high dietary salt intake in mediating cardiovascular and renal morbidity and mortality. Almost five decades ago, Guyton and Coleman proposed that whenever arterial pressure is elevated, pressure natriuresis enhances the excretion of sodium and water until blood volume is reduced sufficiently to return arterial pressure to control values. According to this hypothesis, hypertension can develop only when something impairs the excretory ability of sodium in the kidney. However, recent studies suggest that nonosmotic salt accumulation in the skin interstitium and the endothelial dysfunction which might be caused by the deterioration of vascular endothelial glycocalyx layer (EGL) and the epithelial sodium channel on the endothelial luminal surface (EnNaC) also play an important role in nonosmotic storage of salt. These new concepts emphasize that sodium homeostasis and salt sensitivity seem to be related not only to the kidney malfunction but also to the endothelial dysfunction. Further investigations will be needed to assess the extent to which changes in the sodium buffering capacity of the skin interstitium and develop the treatment strategy for modulating the endothelial dysfunction. PMID:26240595

A method of increasing test range and accuracy of bioindicators: Geobacillus stearothermophilus spores.

PubMed

Lundahl, Gunnel

2003-01-01

Spores of Geobacillus stearothermophilus are very sensitive to changes in temperature. When validating sterilizing processes, the most common bioindicator (BI) is spores of Geobacillus stearothermophilus ATCC12980 and ATCC7953 with about 10(6) spores /BI and a D121-value of about 2 minutes in water. Because these spores of Geobacillus stearothermophilus do not survive at a F0-value above 12 minutes, it has not been possible to evaluate the agreement between the biological F-value (F(BIO)) and physical measurements (time and temperature) when the physical F0-value exceeds that limit. However, it has been proven that glycerin substantially increases the heat resistance of the spores, and it is possible to utilize that property when manufacturing BIs suitable to use in processes with longer sterilization time or high temperature (above 121 degrees C). By the method described, it is possible to make use of the sensitivity and durability of Geobacillus stearothermophilus' spores when glycerin has increased both test range and accuracy. Experience from years of development and validation work with the use of the highly sensitive glycerin-water-spore-suspension sensor (GWS-sensor) is reported. Validation of the steam sterilization process at high temperature has been possible with the use of GWS-sensors. It has also been shown that the spores in suspension keep their characteristics for a period of 19 months when stored cold (8 degrees C).

Implications of changes in households and living arrangements for future home-based care needs and costs for disabled elders in China.

PubMed

Zeng, Yi; Chen, Huashuai; Wang, Zhenglian; Land, Kenneth C

2015-04-01

To better understand future home-based care needs and costs for disabled elders in China. To further develop and apply the ProFamy extended cohort-component method and the most recent census and survey data. (a) Chinese disabled elders and the annual growth rate of the percentage of national gross domestic product (GDP) devoted to home-based care costs for disabled elders will increase much more rapidly than the growth of total elderly population; (b) home-based care needs and costs for disabled oldest-old aged 80+ will increase much faster than that for disabled young-old aged 65-79 after 2030; (c) disabled unmarried elders living alone and their home-based care costs increase substantially faster than those disabled unmarried elders living with children; (d) percent of rural disabled oldest-old will be substantially higher than that of rural population after 2030; (e) sensitivity analyses show that possible changes in mortality and elderly disability status are the major direct factors affecting home-based care needs and costs; (f) caregivers resources under the universal two-child policy will be substantially better than that under the rigorous fertility policy unchanged. We discuss policy recommendations concerning pathways to healthy aging with relatively reduced care costs, including reductions of the prevalence of disability, gender equality, the universal two-child policy and resources of caregivers, encouragements of rural-to-urban family migration and elder's residential proximity to their adult children, and remarriages of not-married elders. © The Author(s) 2014.

Different sensitivities of snowpacks to warming in Mediterranean climate mountain areas

NASA Astrophysics Data System (ADS)

López-Moreno, J. I.; Gascoin, S.; Herrero, J.; Sproles, E. A.; Pons, M.; Alonso-González, E.; Hanich, L.; Boudhar, A.; Musselman, K. N.; Molotch, N. P.; Sickman, J.; Pomeroy, J.

2017-07-01

In this study we quantified the sensitivity of snow to climate warming in selected mountain sites having a Mediterranean climate, including the Pyrenees in Spain and Andorra, the Sierra Nevada in Spain and California (USA), the Atlas in Morocco, and the Andes in Chile. Meteorological observations from high elevations were used to simulate the snow energy and mass balance (SEMB) and calculate its sensitivity to climate. Very different climate sensitivities were evident amongst the various sites. For example, reductions of 9%-19% and 6-28 days in the mean snow water equivalent (SWE) and snow duration, respectively, were found per °C increase. Simulated changes in precipitation (±20%) did not affect the sensitivities. The Andes and Atlas Mountains have a shallow and cold snowpack, and net radiation dominates the SEMB; and explains their relatively low sensitivity to climate warming. The Pyrenees and USA Sierra Nevada have a deeper and warmer snowpack, and sensible heat flux is more important in the SEMB; this explains the much greater sensitivities of these regions. Differences in sensitivity help explain why, in regions where climate models project relatively greater temperature increases and drier conditions by 2050 (such as the Spanish Sierra Nevada and the Moroccan Atlas Mountains), the decline in snow accumulation and duration is similar to other sites (such as the Pyrenees and the USA Sierra Nevada), where models project stable precipitation and more attenuated warming. The snowpack in the Andes (Chile) exhibited the lowest sensitivity to warming, and is expected to undergo only moderate change (a decrease of <12% in mean SWE, and a reduction of < 7 days in snow duration under RCP 4.5). Snow accumulation and duration in the other regions are projected to decrease substantially (a minimum of 40% in mean SWE and 15 days in snow duration) by 2050.

Emotions and stress increase respiratory resistance in asthma.

PubMed

Ritz, T; Steptoe, A; DeWilde, S; Costa, M

2000-01-01

Clinical reports suggest that various emotions and types of stress can precipitate asthmatic symptoms, but there is little experimental evidence to substantiate this claim. We studied the impact of different emotional states and stress on respiratory resistance in asthmatic and nonasthmatic individuals. Participants (24 asthmatic and 24 nonasthmatic patients) viewed short film sequences selected to induce anxiety, anger, depression, elation, happiness, contentment, or a neutral affective state and completed two stressful tasks, mental arithmetic to induce active coping efforts and viewing of medical slides to induce passive coping efforts. Oscillatory resistance, heart rate, blood pressure, baroreflex sensitivity, skin conductance level, respiration rate and volume, and self-reported affective state were measured throughout the session. Uniform increases in oscillatory resistance were found in all emotional states compared with the neutral state and during mental arithmetic in both groups. Asthmatic patients showed stronger reactions to the medical slides than healthy control subjects, with significant increases in oscillatory resistance, blood pressure, skin conductance level, and minute volume, as well as higher levels of self-reported depression, arousal, and shortness of breath. Changes in oscillatory resistance were inconsistently correlated with other physiological indices. Various emotional states and stress increase oscillatory resistance largely independently of concurrent increases in autonomic or ventilatory activity. The particular sensitivity of asthmatics to passive coping demand requires additional research.

JNK pathway activation is controlled by Tao/TAOK3 to modulate ethanol sensitivity.

PubMed

Kapfhamer, David; King, Ian; Zou, Mimi E; Lim, Jana P; Heberlein, Ulrike; Wolf, Fred W

2012-01-01

Neuronal signal transduction by the JNK MAP kinase pathway is altered by a broad array of stimuli including exposure to the widely abused drug ethanol, but the behavioral relevance and the regulation of JNK signaling is unclear. Here we demonstrate that JNK signaling functions downstream of the Sterile20 kinase family gene tao/Taok3 to regulate the behavioral effects of acute ethanol exposure in both the fruit fly Drosophila and mice. In flies tao is required in neurons to promote sensitivity to the locomotor stimulant effects of acute ethanol exposure and to establish specific brain structures. Reduced expression of key JNK pathway genes substantially rescued the structural and behavioral phenotypes of tao mutants. Decreasing and increasing JNK pathway activity resulted in increased and decreased sensitivity to the locomotor stimulant properties of acute ethanol exposure, respectively. Further, JNK expression in a limited pattern of neurons that included brain regions implicated in ethanol responses was sufficient to restore normal behavior. Mice heterozygous for a disrupted allele of the homologous Taok3 gene (Taok3Gt) were resistant to the acute sedative effects of ethanol. JNK activity was constitutively increased in brains of Taok3Gt/+ mice, and acute induction of phospho-JNK in brain tissue by ethanol was occluded in Taok3Gt/+ mice. Finally, acute administration of a JNK inhibitor conferred resistance to the sedative effects of ethanol in wild-type but not Taok3Gt/+ mice. Taken together, these data support a role of a TAO/TAOK3-JNK neuronal signaling pathway in regulating sensitivity to acute ethanol exposure in flies and in mice.

The relevance of using 3D cell cultures, in addition to 2D monolayer cultures, when evaluating breast cancer drug sensitivity and resistance

PubMed Central

Breslin, Susan; O'Driscoll, Lorraine

2016-01-01

Solid tumours naturally grow in 3D wherein the spatial arrangement of cells affects how they interact with each other. This suggests that 3D cell culture may mimic the natural in vivo setting better than traditional monolayer (2D) cell culture, where cells are grown attached to plastic. Here, using HER2-positive breast cancer cell lines as models (BT474, HCC1954, EFM192A), the effects of culturing cells in 3D using the poly-HEMA method compared to 2D cultures were assessed in terms of cellular viability, response/resistance to anti-cancer drugs, protein expression and enzyme activity. Scanning electron microscopy showed the morphology of cells in 3D to be substantially different to those cultured in 2D. Cell viability in 3D cells was substantially lower than that of cells in 2D cultures, while 3D cultures were more resistant to the effects of HER-targeted (neratinib) and classical chemotherapy (docetaxel) drugs. Expression of proteins involved in cell survival, transporters associated with drug resistance and drug targets were increased in 3D cultures. Finally, activity of drug metabolising enzyme CYP3A4 was substantially increased in 3D compared to 2D cultures. Together this data indicates that the biological information represented by 3D and 2D cell cultures is substantially different i.e. 3D cell cultures demonstrate higher innate resistance to anti-cancer drugs compared to 2D cultures, which may be facilitated by the altered receptor proteins, drug transporters and metabolising enzyme activity. This highlights the importance of considering 3D in addition to 2D culture methods in pre-clinical studies of both newer targeted and more traditional anti-cancer drugs. PMID:27304190

Effects of ultraviolet-B radiation on fungal disease development in Cucumis sativus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orth, A.B.; Teramura, A.H.; Sisler, H.D.

1990-09-01

Stratospheric ozone depletion due to increased atmospheric pollutants has received considerable attention because of the potential increase in ultraviolet-B (UV-B, 280-320 nm) radiation that will reach the earth's surface. Three cucumber (Cucumis sativus L.) cultivars were exposed to a daily dose of 11.6 kJ m{sup {minus}2} biologically effective ultraviolet-B (UV-B{sub BE}) radiation in an unshaded greenhouse before and/or after injection by Colletotrichum lagenarium (Pass.) Ell. and Halst. or Cladosporium cucumerinum Ell. and Arth. and analyzed for disease development. Two of these cultivars, Poinsette and Calypso Hybrid, were disease resistant, while the third cultivar, Straight-8, was disease susceptible. Preinfectional treatment ofmore » 1 to 7 days with UV-B{sub BE} in Straight-8 led to greater severity of both diseases. Postinfectional UV treatment did not lead to increased disease severity caused by C. lagenarium, while preinfectional UV treatment in both Straight-8 and Poinsette substantially increased disease severity. Although resistant cultivars Poinsette and Calypso Hybrid showed increased anthracnose disease severity when exposed to UV-B, this effect was apparent only on the cotyledons. Both higher spore concentration and exposure to UV-B radiation resulted in greater disease severity. Of the cucumber cultivars tested for UV-B sensitivity, growth in Poinsette was most sensitive and Calypso Hybrid was least sensitive. These preliminary results indicate that the effects of UV-B radiation on disease development in cucumber vary depending on cultivar, timing and duration of UV-B exposure, inoculation level, and plant age.« less

Constraints on High Northern Photosynthesis Increase Using Earth System Models and a Set of Independent Observations

NASA Astrophysics Data System (ADS)

Winkler, A. J.; Brovkin, V.; Myneni, R.; Alexandrov, G.

2017-12-01

Plant growth in the northern high latitudes benefits from increasing temperature (radiative effect) and CO2 fertilization as a consequence of rising atmospheric CO2 concentration. This enhanced gross primary production (GPP) is evident in large scale increase in summer time greening over the 36-year record of satellite observations. In this time period also various global ecosystem models simulate a greening trend in terms of increasing leaf area index (LAI). We also found a persistent greening trend analyzing historical simulations of Earth system models (ESM) participating in Phase 5 of the Coupled Model Intercomparison Project (CMIP5). However, these models span a large range in strength of the LAI trend, expressed as sensitivity to both key environmental factors, temperature and CO2 concentration. There is also a wide spread in magnitude of the associated increase of terrestrial GPP among the ESMs, which contributes to pronounced uncertainties in projections of future climate change. Here we demonstrate that there is a linear relationship across the CMIP5 model ensemble between projected GPP changes and historical LAI sensitivity, which allows using the observed LAI sensitivity as an "emerging constraint" on GPP estimation at future CO2 concentration. This constrained estimate of future GPP is substantially higher than the traditional multi-model mean suggesting that the majority of current ESMs may be significantly underestimating carbon fixation by vegetation in NHL. We provide three independent lines of evidence in analyzing observed and simulated CO2 amplitude as well as atmospheric CO2 inversion products to arrive at the same conclusion.

Double-gated Si NW FET sensors: Low-frequency noise and photoelectric properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gasparyan, F.; Forschungszentrum Jülich, Peter Grünberg Institute; Khondkaryan, H.

2016-08-14

The transport, noise, and photosensitivity properties of an array of silicon nanowire (NW) p{sup +}-p-p{sup +} field-effect transistors (FETs) are investigated. The peculiarities of photosensitivity and detectivity are analyzed over a wide spectrum range. The absorbance of p-Si NW shifts to the short wavelength region compared with bulk Si. The photocurrent and photosensitivity reach increased values in the UV range of the spectrum at 300 K. It is shown that sensitivity values can be tuned by the drain-source voltage and may reach record values of up to 2–4 A/W at a wavelength of 300 nm at room temperature. Low-frequency noise studies allow calculatingmore » the photodetectivity values, which increase with decreasing wavelength down to 300 nm. We show that the drain current of Si NW biochemical sensors substantially depends on pH value and the signal-to-noise ratio reaches the high value of 10{sup 5}. Increasing pH sensitivity with gate voltage is revealed for certain source-drain currents of pH-sensors based on Si NW FETs. The noise characteristic index decreases from 1.1 to 0.7 with the growth of the liquid gate voltage. Noise behavior is successfully explained in the framework of the correlated number-mobility unified fluctuation model. pH sensitivity increases as a result of the increase in liquid gate voltage, thus giving the opportunity to measure very low proton concentrations in the electrolyte medium at certain values of the liquid gate voltage.« less

Impact of variations in triage cytology interpretation on human papillomavirus-based cervical screening and implications for screening algorithms.

PubMed

Ronco, Guglielmo; Zappa, Marco; Franceschi, Silvia; Tunesi, Sara; Caprioglio, Adele; Confortini, Massimo; Del Mistro, Annarosa; Carozzi, Francesca; Segnan, Nereo; Zorzi, Manuel; Giorgi-Rossi, Paolo

2016-11-01

Women positive to human papillomavirus (HPV+) testing at cervical screening need triage, typically cytology and immediate colposcopy in case of atypical squamous cells of undetermined significance (ASCUS) or worse (ASCUS+) or, in cytology-normal HPV+ women, HPV test repeat after 1 year and colposcopy referral if still HPV+. Our hypothesis was that substantial variations in triage positivity and sensitivity may produce little variation in overall referral to colposcopy and on sensitivity of the entire screening process. Centre- and age-aggregated data from 72,869 women aged 35-64 years were derived from 10 organised screening programmes which have piloted HPV screening in Italy since 2012. Overall colposcopy referral was evaluated as a function of immediate colposcopy referral and overall CIN2+ detection as a function of the proportion of all CIN2+ detected by immediate referral (a proxy of cytology's sensitivity). We fitted additive regression models, adjusted for centre, age, compliance to HPV retesting and to colposcopy, by generalised estimation equations. The proportion of HPV+ women directly referred to colposcopy varied across programmes (20-57%; average 37%) and so did CIN2+ detection (49-94%; average 77%). Overall, 63% (range 41-75%) of HPV+ were referred to colposcopy either immediately or at HPV repeat. An absolute 10% increase in immediate colposcopy referral resulted in 4.2% (95% CI: 3.3-5.1%) increase in overall referral. An absolute 10% increase in cytology's sensitivity resulted in a 1.1% (95% CI: 0.1-2.0%) increase in overall CIN2+ detection. Repeat HPV testing limits the effect of subjectivity of cytology interpretation on overall referral and sensitivity. These will change only slightly when replacing cytology with another test if the interval to HPV repeat remains unchanged. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Increased atmospheric ammonia over the world's major agricultural areas detected from space

NASA Astrophysics Data System (ADS)

Warner, J. X.; Dickerson, R. R.; Wei, Z.; Strow, L. L.; Wang, Y.; Liang, Q.

2017-03-01

This study provides evidence of substantial increases in atmospheric ammonia (NH3) concentrations (14 year) over several of the worlds major agricultural regions, using recently available retrievals from the Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite. The main sources of atmospheric NH3 are farming and animal husbandry involving reactive nitrogen ultimately derived from fertilizer use; rates of emission are also sensitive to climate change. Significant increasing trends are seen over the U.S. (2.61% yr-1), the European Union (EU) (1.83% yr-1), and China (2.27% yr-1). Over the EU, the trend results from decreased scavenging by acid aerosols. Over the U.S., the increase results from a combination of decreased chemical loss and increased soil temperatures. Over China, decreased chemical loss, increasing temperatures, and increased fertilizer use all play a role. Over South Asia, increased NH3 emissions are masked by increased SO2 and NOx emissions, leading to increased aerosol loading and adverse health effects.

Increased atmospheric ammonia over the world’s major agricultural areas detected from space

PubMed Central

Warner, J. X.; Dickerson, R. R.; Wei, Z.; Strow, L. L.; Wang, Y.; Liang, Q.

2018-01-01

This study provides evidence of substantial increases in atmospheric ammonia (NH3) concentrations (14-year) over several of the worlds major agricultural regions, using recently available retrievals from the Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite. The main sources of atmospheric NH3 are farming and animal husbandry involving reactive nitrogen ultimately derived from fertilizer use; rates of emission are also sensitive to climate change. Significant increasing trends are seen over the US (2.61% yr−1), the European Union (EU) (1.83% yr−1), and China (2.27% yr−1). Over the EU, the trend results from decreased scavenging by acid aerosols. Over the US, the increase results from a combination of decreased chemical loss and increased soil temperatures. Over China, decreased chemical loss, increasing temperatures, and increased fertilizer use all play a role. Over South Asia, increased NH3 emissions are masked by increased SO2 and NOx emissions, leading to increased aerosol loading and adverse health effects. PMID:29657344

Increased Atmospheric Ammonia over the World's Major Agricultural Areas Detected from Space

NASA Technical Reports Server (NTRS)

Warner, J. X.; Dickerson, R. R.; Wei, Z.; Strow, L. L.; Wang, Y.; Liang, Q.

2017-01-01

This study provides evidence of substantial increases in atmospheric ammonia (NH3) concentrations (14-year) over several of the worlds major agricultural regions, using recently available retrievals from the Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite. The main sources of atmospheric NH3 are farming and animal husbandry involving reactive nitrogen ultimately derived from fertilizer use; rates of emission are also sensitive to climate change. Significant increasing trends are seen over the U.S. (2.61%?per yr), the European Union (EU) (1.83%?per yr), and China (2.27%?per yr). Over the EU, the trend results from decreased scavenging by acid aerosols. Over the U.S., the increase results from a combination of decreased chemical loss and increased soil temperatures. Over China, decreased chemical loss, increasing temperatures, and increased fertilizer use all play a role. Over South Asia, increased NH3 emissions are masked by increased SO2 and NOX emissions, leading to increased aerosol loading and adverse health effects.

Effects of Chronic Consumption of Sugar-Enriched Diets on Brain Metabolism and Insulin Sensitivity in Adult Yucatan Minipigs.

PubMed

Ochoa, Melissa; Malbert, Charles-Henri; Meurice, Paul; Val-Laillet, David

2016-01-01

Excessive sugar intake might increase the risk to develop eating disorders via an altered reward circuitry, but it remains unknown whether different sugar sources induce different neural effects and whether these effects are dependent from body weight. Therefore, we compared the effects of three high-fat and isocaloric diets varying only in their carbohydrate sources on brain activity of reward-related regions, and assessed whether brain activity is dependent on insulin sensitivity. Twenty-four minipigs underwent 18FDG PET brain imaging following 7-month intake of high-fat diets of which 20% in dry matter weight (36.3% of metabolisable energy) was provided by starch, glucose or fructose (n = 8 per diet). Animals were then subjected to a euglycemic hyperinsulinemic clamp to determine peripheral insulin sensitivity. After a 7-month diet treatment, all groups had substantial increases in body weight (from 36.02±0.85 to 63.33±0.81 kg; P<0.0001), regardless of the diet. All groups presented similar insulin sensitivity index (ISI = 1.39±0.10 mL·min-1·μUI·kg). Compared to starch, chronic exposure to fructose and glucose induced bilateral brain activations, i.e. increased basal cerebral glucose metabolism, in several reward-related brain regions including the anterior and dorsolateral prefrontal cortex, the orbitofrontal cortex, the anterior cingulate cortex, the caudate and putamen. The lack of differences in insulin sensitivity index and body weight suggests that the observed differences in basal brain glucose metabolism are not related to differences in peripheral insulin sensitivity and weight gain. The differences in basal brain metabolism in reward-related brain areas suggest the onset of cerebral functional alterations induced by chronic consumption of dietary sugars. Further studies should explore the underlying mechanisms, such as the availability of intestinal and brain sugar transporter, or the appearance of addictive-like behavioral correlates of these brain functional characteristics.

Body fat distribution modulates insulin sensitivity in post-menopausal overweight and obese women: a MONET study.

PubMed

Tousignant, B; Faraj, M; Conus, F; Garrel, D; Brochu, M; Rabasa-Lhoret, R; Coderre, L

2008-11-01

Central fat mass (CFM) correlates with insulin resistance and increases the risk of type 2 diabetes and cardiovascular complications. On the other hand, increased peripheral fat mass (PFM) is associated with higher insulin sensitivity. Thus, we examined the contribution of adipose tissue distribution, as assessed by the PFM/CFM ratio, to insulin sensitivity in overweight and obese postmenopausal women. A total of 124 nondiabetic overweight and obese postmenopausal women underwent an oral glucose tolerance test (OGTT) and a hyperinsulinemic/euglycemic (HI) clamp. Body composition was determined using computed tomography for visceral adipose tissue (VAT) and dual X-ray absorptiometry for fat mass, lean body mass and their respective proportions. Participants were divided by tertiles of the PFM/CFM ratio. Participants with preferential CFM (group 1) had higher fasting insulin levels and insulin area under the curve (AUC) during OGTT, as well as lower glucose infusion rates during the HI clamp, whether it was expressed per kg of body weight (M) or per kg of fat-free mass (Mm), compared with the other two groups. The PFM/CFM ratio also correlated significantly with fasting insulin (r=-0.32, P<0.001), the insulin AUC (r=-0.42 P<0.001), M (r=0.39 P<0.001) and Mm (r=0.37 P<0.001). Using hierarchical regression, we demonstrated that the PFM/CFM ratio was an independent predictor of insulin AUC, M and Mm and that its sequential addition to CFM and VAT improved significantly the predictive value of the model for insulin sensitivity for all variables except fasting insulin. The PFM/CFM ratio, which integrates the antagonistic effects of both central and peripheral depots on insulin sensitivity, added substantially to the prediction of insulin sensitivity over VAT and CFM alone.

Effects of gasoline engine emissions on preexisting allergic airway responses in mice.

PubMed

Day, Kimberly C; Reed, Matthew D; McDonald, Jacob D; Seilkop, Steven K; Barrett, Edward G

2008-10-01

Gasoline-powered vehicle emissions contribute significantly to ambient air pollution. We hypothesized that exposure to gasoline engine emissions (GEE) may exacerbate preexisting allergic airway responses. Male BALB/c mice were sensitized by injection with ovalbumin (OVA) and then received a 10-min aerosolized OVA challenge. Parallel groups were sham-sensitized with saline. Mice were exposed 6 h/day to air (control, C) or GEE containing particulate matter (PM) at low (L), medium (M), or high (H) concentrations, or to the H level with PM removed by filtration (high-filtered, HF). Immediately after GEE exposure mice received another 10-min aerosol OVA challenge (pre-OVA protocol). In a second (post-OVA) protocol, mice were similarly sensitized but only challenged to OVA before air or GEE exposure. Measurements of airway hyperresponsiveness (AHR), bronchoalveolar lavage (BAL), and blood collection were performed approximately 24 h after the last exposure. In both protocols, M, H, and HF GEE exposure significantly decreased BAL neutrophils from nonsensitized mice but had no significant effect on BAL cells from OVA-sensitized mice. In the pre-OVA protocol, GEE exposure increased OVA-specific IgG(1) but had no effect on BAL interleukin (IL)-2, IL-4, IL-13, or interferon (IFN)-gamma in OVA-sensitized mice. Nonsensitized GEE-exposed mice had increased OVA-specific IgG(2a), IgE, and IL-2, but decreased total IgE. In the post-OVA protocol, GEE exposure reduced BAL IL-4, IL-5, and IFN-gamma in nonsensitized mice but had no effect on sensitized mice. These results suggest acute exposure to the gas-vapor phase of GEE suppressed inflammatory cells and cytokines from nonsensitized mice but did not substantially exacerbate allergic responses.

Cell-intrinsic determinants of ibrutinib-induced apoptosis in Chronic Lymphocytic Leukemia

PubMed Central

Amin, Nisar A.; Balasubramanian, Sriram; Saiya-Cork, Kamlai; Shedden, Kerby; Hu, Nan; Malek, Sami N.

2016-01-01

Purpose Ibrutinib, a Bruton’s tyrosine kinase (BTK) inhibitor, is approved for the treatment of relapsed CLL and CLL with del17p. Mechanistically, ibrutinib interferes with BCR signaling as well as multiple CLL cell to microenvironment interactions. Given the importance of ibrutinib in the management of CLL, a deeper understanding of factors governing sensitivity and resistance is warranted. Experimental Design We studied 48 longitudinally sampled paired CLL samples, 42 of which were procured before and after standard CLL chemotherapies, and characterized them for well-studied CLL molecular traits as well as by whole exome sequencing and SNP 6.0 array profiling. We exposed these samples to 0.25 μM – 5 μM of ibrutinib ex vivo and measured apoptosis fractions as well as BCR signaling by immunoblotting. We disrupted TP53 in HG3, PGA1 and PG-EBV cell lines and measured BCR signaling and ibrutinib responses. Results CLL samples demonstrated a surprisingly wide range of ex vivo sensitivities to ibrutinib with IC50 values ranging from 0.4 μM – 9.7 μM. Unmutated IGVH status, elevated ZAP70 expression and trisomy 12 were associated with heightened sensitivity to ibrutinib treatment. Five CLL samples were substantially more resistant to ibrutinib following relapse from chemotherapy; of these, three had acquired a del17p/TP53 mutated status. A validation sample of 15 CLL carrying TP53 mutations, of which 13 carried both del17p and a TP53 mutation confirmed substantially less sensitivity to ibrutinib-induced apoptosis. Conclusions This study identifies that CLL harboring del17p/TP53 mutated cells are substantially less sensitive to ibrutinib-induced apoptosis than del17p/TP53 wild type cells. PMID:27535981

Stress in adolescence and drugs of abuse in rodent models: Role of dopamine, CRF, and HPA axis

PubMed Central

Burke, Andrew R.; Miczek, Klaus A.

2014-01-01

Rationale Research on adolescence and drug abuse increased substantially in the past decade. However, drug-addiction related behaviors following stressful experiences during adolescence are less studied. We focus on rodent models of adolescent stress cross-sensitization to drugs of abuse. Objectives Review the ontogeny of behavior, dopamine, corticotropin-releasing factor (CRF), and the hypothalamic pituitary adrenal (HPA) axis in adolescent rodents. We evaluate evidence that stressful experiences during adolescence engender hypersensitivity to drugs of abuse and offer potential neural mechanisms. Results and Conclusions Much evidence suggests that final maturation of behavior, dopamine systems, and HPA axis occurs during adolescence. Stress during adolescence increases amphetamine- and ethanol-stimulated locomotion, preference, and self-administration under many conditions. The influence of adolescent stress on subsequent cocaine- and nicotine-stimulated locomotion and preference is less clear. The type of adolescent stress, temporal interval between stress and testing, species, sex, and the drug tested are key methodological determinants for successful cross-sensitization procedures. The sensitization of the mesolimbic dopamine system is proposed to underlie stress cross-sensitization to drugs of abuse in both adolescents and adults through modulation by CRF. Reduced levels of mesocortical dopamine appear to be a unique consequence of social stress during adolescence. Adolescent stress may reduce the final maturation of cortical dopamine through D2 dopamine receptor regulation of dopamine synthesis or glucocorticoid-facilitated pruning of cortical dopamine fibers. Certain rodent models of adolescent adversity are useful for determining neural mechanisms underlying the cross-sensitization to drugs of abuse. PMID:24370534

Poly(ADP-ribose) polymerase inhibitors sensitize cancer cells to death receptor-mediated apoptosis by enhancing death receptor expression.

PubMed

Meng, X Wei; Koh, Brian D; Zhang, Jin-San; Flatten, Karen S; Schneider, Paula A; Billadeau, Daniel D; Hess, Allan D; Smith, B Douglas; Karp, Judith E; Kaufmann, Scott H

2014-07-25

Recombinant human tumor necrosis factor-α-related apoptosis inducing ligand (TRAIL), agonistic monoclonal antibodies to TRAIL receptors, and small molecule TRAIL receptor agonists are in various stages of preclinical and early phase clinical testing as potential anticancer drugs. Accordingly, there is substantial interest in understanding factors that affect sensitivity to these agents. In the present study we observed that the poly(ADP-ribose) polymerase (PARP) inhibitors olaparib and veliparib sensitize the myeloid leukemia cell lines ML-1 and K562, the ovarian cancer line PEO1, non-small cell lung cancer line A549, and a majority of clinical AML isolates, but not normal marrow, to TRAIL. Further analysis demonstrated that PARP inhibitor treatment results in activation of the FAS and TNFRSF10B (death receptor 5 (DR5)) promoters, increased Fas and DR5 mRNA, and elevated cell surface expression of these receptors in sensitized cells. Chromatin immunoprecipitation demonstrated enhanced binding of the transcription factor Sp1 to the TNFRSF10B promoter in the presence of PARP inhibitor. Knockdown of PARP1 or PARP2 (but not PARP3 and PARP4) not only increased expression of Fas and DR5 at the mRNA and protein level, but also recapitulated the sensitizing effects of the PARP inhibition. Conversely, Sp1 knockdown diminished the PARP inhibitor effects. In view of the fact that TRAIL is part of the armamentarium of natural killer cells, these observations identify a new facet of PARP inhibitor action while simultaneously providing the mechanistic underpinnings of a novel therapeutic combination that warrants further investigation.

Effects of mycoplasma contamination on phenotypic expression of mitochondrial mutants in human cells.

PubMed Central

Doersen, C J; Stanbridge, E J

1981-01-01

HeLa cells sensitive to the mitochondrial protein synthesis inhibitors erythromycin (ERY) and chloramphenicol (CAP) and HeLa variants resistant to the effects of these drugs were purposefully infected with drug-sensitive and -resistant mycoplasma strains. Mycoplasma hyorhinis and the ERY-resistant strain of Mycoplasma orale, MO-ERYr, did not influence the growth of HeLa and ERY-resistant ERY2301 cells in the presence or absence of ERY. M. hyorhinis also did not affect the growth of HeLa and CAP-resistant Cap-2 cells in the presence or absence of CAP. However, both HeLa and Cap-2 cells infected with the CAP-resistant strain of M. hyorhinis, MH-CAPr, were more sensitive to the cytotoxic effect of CAP. This may be due to the glucose dependence of the cells, which was compromised by the increased utilization of glucose by MH-CAPr in these infected cell cultures. In vitro protein synthesis by isolated mitochondria was significantly altered by mycoplasma infection of the various cell lines. A substantial number of mycoplasmas copurified with the mitochondria, resulting in up to a sevenfold increase in the incorporation of [3H]leucine into the trichloroacetic acid-insoluble material. More importantly, the apparent drug sensitivity or resistance of mitochondrial preparations from mycoplasma-infected cells reflected the drug sensitivity or resistance of the contaminating mycoplasmas. These results illustrate the hazards in interpreting mitochondrial protein synthesis data derived from mycoplasma-infected cell lines, particularly putative mitochondrially encoded mutants resistant to inhibitors of mitochondrial protein synthesis. PMID:6965101

Accuracy of a disability instrument to identify workers likely to develop upper extremity musculoskeletal disorders.

PubMed

Stover, Bert; Silverstein, Barbara; Wickizer, Thomas; Martin, Diane P; Kaufman, Joel

2007-06-01

Work related upper extremity musculoskeletal disorders (MSD) result in substantial disability, and expense. Identifying workers or jobs with high risk can trigger intervention before workers are injured or the condition worsens. We investigated a disability instrument, the QuickDASH, as a workplace screening tool to identify workers at high risk of developing upper extremity MSDs. Subjects included workers reporting recurring upper extremity MSD symptoms in the past 7 days (n = 559). The QuickDASH was reasonably accurate at baseline with sensitivity of 73% for MSD diagnosis, and 96% for symptom severity. Specificity was 56% for diagnosis, and 53% for symptom severity. At 1-year follow-up sensitivity and specificity for MSD diagnosis was 72% and 54%, respectively, as predicted by the baseline QuickDASH score. For symptom severity, sensitivity and specificity were 86% and 52%. An a priori target sensitivity of 70% and specificity of 50% was met by symptom severity, work pace and quality, and MSD diagnosis. The QuickDASH may be useful for identifying jobs or workers with increased risk for upper extremity MSDs. It may provide an efficient health surveillance screening tool useful for targeting early workplace intervention for prevention of upper extremity MSD problems.

RNA editing of the GABAA receptor α3 subunit alters the functional properties of recombinant receptors

PubMed Central

Nimmich, Mitchell L.; Heidelberg, Laura S.; Fisher, Janet L.

2009-01-01

RNA editing provides a post-transcriptional mechanism to increase structural heterogeneity of gene products. Recently, the α3 subunit of the GABAA receptors has been shown to undergo RNA editing. As a result, a highly conserved isoleucine residue in the third transmembrane domain is replaced with a methionine. To determine the effect of this structural change on receptor function, we compared the GABA sensitivity, pharmacological properties and macroscopic kinetics of recombinant receptors containing either the edited or unedited forms of the α3 subunit along with β3 and γ2L. Editing substantially altered the GABA sensitivity and deactivation rate of the receptors, with the unedited form showing a lower GABA EC50 and slower decay. Comparable effects were observed with a mutation at the homologous location in the α1 subunit, suggesting a common role for this site in regulation of channel gating. Except for the response to GABA, the pharmacological properties of the receptor were unaffected by editing, with similar enhancement by a variety of modulators. Since RNA editing of the α3 subunit increases through development, our findings suggest that GABAergic neurotransmission may be more effective early in development, with greater GABA sensitivity and slower decay rates conferred by the unedited α3 subunit. PMID:19367790

Nanoprobe-Enhanced, Split Aptamer-Based Electrochemical Sandwich Assay for Ultrasensitive Detection of Small Molecules.

PubMed

Zhao, Tao; Liu, Ran; Ding, Xiaofan; Zhao, Juncai; Yu, Haixiang; Wang, Lei; Xu, Qing; Wang, Xuan; Lou, Xinhui; He, Miao; Xiao, Yi

2015-08-04

It is quite challenging to improve the binding affinity of antismall molecule aptamers. We report that the binding affinity of anticocaine split aptamer pairs improved by up to 66-fold by gold nanoparticles (AuNP)-attached aptamers due to the substantially increased local concentration of aptamers and multiple and simultaneous ligand interactions. The significantly improved binding affinity enables the detection of small molecule targets with unprecedented sensitivity, as demonstrated in nanoprobe-enhanced split aptamer-based electrochemical sandwich assays (NE-SAESA). NE-SAESA replaces the traditional molecular reporter probe with AuNPs conjugated to multiple reporter probes. The increased binding affinity allowed us to use 1,000-fold lower reporter probe concentrations relative to those employed in SAESA. We show that the near-elimination of background in NE-SAESA effectively improves assay sensitivity by ∼1,000-100,000-fold for ATP and cocaine detection, relative to equivalent SAESA. With the ongoing development of new strategies for the selection of aptamers, we anticipate that our sensor platform should offer a generalizable approach for the high-sensitivity detection of diverse targets. More importantly, we believe that NE-SAESA represents a novel strategy to improve the binding affinity between a small molecule and its aptamer and potentially can be extended to other detection platforms.

Immunologic studies of poisonous Anacardiaceae: I. Production of tolerance and desensitization to poison Ivy and oak urushiols using esterified urushiol derivatives in guinea pigs.

PubMed

Watson, E S; Murphy, J C; Wirth, P W; Waller, C W; Elsohly, M A

1981-03-01

The development of contact sensitivity to poison ivy urushiol in Hartley guinea pigs was inhibited by i.v. injection of the diacetate esters of poison ivy and oak urushiols into guinea pigs 2 weeks prior to attempted sensitization with homologous antigen. Immune tolerance to urushiols of poison ivy and oak developed in 80% or more of the treated animals and persisted for the duration of the study, 8 weeks. The tolerance was immunologically specific for urushiols since the tolerant animals were sensitizable to the unrelated sensitizer 2, 4-dinitrochlorobenzene. Guinea pigs already sensitive to urushiol were also desensitized or hyposensitizied by i.v. injection of urushiol acetates in successively increasing doses. After receiving the equivalent of 16 mg of poison ivy and oak urushiols in the acetate form over a period of 12 weeks, 54% of a group of guinea pigs were desensitized to poison ivy. all of the remaining 46% of the guinea pigs still sensitive to poison ivy were substantially hyposensitized (no longer responded to 1.5 or 0.80 microgram test doses of PDC). A control group of guinea pigs was not hyposensitized by injection of vehicle, and remained highly sensitive throughout the 15 week study. The majority of treated animals (less than 80%) were also hyposensitized to poison sumac and cashew nut shell liquid allergens.

Energetic materials and methods of tailoring electrostatic discharge sensitivity of energetic materials

DOEpatents

Daniels, Michael A.; Heaps, Ronald J.; Wallace, Ronald S.; Pantoya, Michelle L.; Collins, Eric S.

2016-11-01

An energetic material comprising an elemental fuel, an oxidizer or other element, and a carbon nanofiller or carbon fiber rods, where the carbon nanofiller or carbon fiber rods are substantially homogeneously dispersed in the energetic material. Methods of tailoring the electrostatic discharge sensitivity of an energetic material are also disclosed.

Sensitivity of summer stream temperatures to climate variability in the Pacific Northwest

Treesearch

Charles Luce; Brian Staab; Marc Kramer; Seth Wenger; Dan Isaak; Callie McConnell

2014-01-01

Estimating the thermal response of streams to a warming climate is important for prioritizing native fish conservation efforts. While there are plentiful estimates of air temperature responses to climate change, the sensitivity of streams, particularly small headwater streams, to warming temperatures is less well understood. A substantial body of literature correlates...

When does mass screening for open neural tube defects in low-risk pregnancies result in cost savings?

PubMed Central

Tosi, L L; Detsky, A S; Roye, D P; Morden, M L

1987-01-01

Using a decision analysis model, we estimated the savings that might be derived from a mass prenatal screening program aimed at detecting open neural tube defects (NTDs) in low-risk pregnancies. Our baseline analysis showed that screening v. no screening could be expected to save approximately $8 per pregnancy given a cost of $7.50 for the maternal serum alpha-feto-protein (MSAFP) test and a cost of $42,507 for hospital and rehabilitation services for the first 10 years of life for a child with spina bifida. When a more liberal estimate of the costs of caring for such a child was used, the savings with the screening program were more substantial. We performed extensive sensitivity analyses, which showed that the savings were somewhat sensitive to the cost of the MSAFP test and highly sensitive to the specificity (but not the sensitivity) of the test. A screening program for NTDs in low-risk pregnancies may result in substantial savings in direct health care costs if the screening protocol is followed rigorously and efficiently. PMID:2433011

Effects of temperature on biochemical reactions and drug resistance of virulent and avirulent Aeromonas salmonicida

USGS Publications Warehouse

Hahnel, G.B.; Gould, R.W.

1982-01-01

Incubation temperatures of 11°, 18° and 28° did not substantially affect biochemical reactions of either virulent or avirulent forms of Aeromonas salmonicida subspecies salmonicida. The only change observed, amygdalin fermentation, was positive at 11° and 18° but negative at 28°C. Several isolates utilized sucrose, a characteristic not normally recognized for A. salmonicida subspecies salmonicida.Antimicrobial susceptibility screening indicated resistance to novobiocin increased at the higher incubation temperatures. Standardized drug sensitivity testing procedures and precise zone diameter interpretive standards for bacterial fish pathogens are needed.

Climate impacts on agricultural land use in the USA: the role of socio-economic scenarios

USGS Publications Warehouse

Mu, Jianhong E.; Sleeter, Benjamin M.; Abatzoglou, John T.; Antle, John M.

2017-01-01

We examine the impacts of climate on net returns from crop and livestock production and the resulting impact on land-use change across the contiguous USA. We first estimate an econometric model to project effects of weather fluctuations on crop and livestock net returns and then use a semi-reduced form land-use share model to study agricultural land-use changes under future climate and socio-economic scenarios. Estimation results show that crop net returns are more sensitive to thermal and less sensitive to moisture variability than livestock net returns; other agricultural land uses substitute cropland use when 30-year averaged degree-days or precipitation are not beneficial for crop production. Under future climate and socio-economic scenarios, we project that crop and livestock net returns are both increasing, but with crop net returns increasing at a higher rate; cropland increases with declines of marginal and pastureland by the end of the twenty-first century. Projections also show that impacts of future climate on agricultural land uses are substantially different and a larger variation of land-use change is evident when socio-economic scenarios are incorporated into the climate impact analysis.

Repeated Solid-state Dewetting of Thin Gold Films for Nanogap-rich Plasmonic Nanoislands.

PubMed

Kang, Minhee; Park, Sang-Gil; Jeong, Ki-Hun

2015-10-15

This work reports a facile wafer-level fabrication for nanogap-rich gold nanoislands for highly sensitive surface enhanced Raman scattering (SERS) by repeating solid-state thermal dewetting of thin gold film. The method provides enlarged gold nanoislands with small gap spacing, which increase the number of electromagnetic hotspots and thus enhance the extinction intensity as well as the tunability for plasmon resonance wavelength. The plasmonic nanoislands from repeated dewetting substantially increase SERS enhancement factor over one order-of-magnitude higher than those from a single-step dewetting process and they allow ultrasensitive SERS detection of a neurotransmitter with extremely low Raman activity. This simple method provides many opportunities for engineering plasmonics for ultrasensitive detection and highly efficient photon collection.

Repeated Solid-state Dewetting of Thin Gold Films for Nanogap-rich Plasmonic Nanoislands

PubMed Central

Kang, Minhee; Park, Sang-Gil; Jeong, Ki-Hun

2015-01-01

This work reports a facile wafer-level fabrication for nanogap-rich gold nanoislands for highly sensitive surface enhanced Raman scattering (SERS) by repeating solid-state thermal dewetting of thin gold film. The method provides enlarged gold nanoislands with small gap spacing, which increase the number of electromagnetic hotspots and thus enhance the extinction intensity as well as the tunability for plasmon resonance wavelength. The plasmonic nanoislands from repeated dewetting substantially increase SERS enhancement factor over one order-of-magnitude higher than those from a single-step dewetting process and they allow ultrasensitive SERS detection of a neurotransmitter with extremely low Raman activity. This simple method provides many opportunities for engineering plasmonics for ultrasensitive detection and highly efficient photon collection. PMID:26469768

Climate reddening increases the chance of critical transitions

NASA Astrophysics Data System (ADS)

van der Bolt, Bregje; van Nes, Egbert H.; Bathiany, Sebastian; Vollebregt, Marlies E.; Scheffer, Marten

2018-06-01

Climate change research often focuses on trends in the mean and variance. However, analyses of palaeoclimatic and contemporary dynamics reveal that climate memory — as measured for instance by temporal autocorrelation — may also change substantially over time. Here, we show that elevated temporal autocorrelation in climatic variables should be expected to increase the chance of critical transitions in climate-sensitive systems with tipping points. We demonstrate that this prediction is consistent with evidence from forests, coral reefs, poverty traps, violent conflict and ice sheet instability. In each example, the duration of anomalous dry or warm events elevates chances of invoking a critical transition. Understanding the effects of climate variability thus requires research not only on variance, but also on climate memory.

Top-down regulation, climate and multi-decadal changes in coastal zoobenthos communities in two Baltic Sea areas.

PubMed

Olsson, Jens; Bergström, Lena; Gårdmark, Anna

2013-01-01

The structure of many marine ecosystems has changed substantially during recent decades, as a result of overexploitation, climate change and eutrophication. Despite of the apparent ecological and economical importance of coastal areas and communities, this aspect has received relatively little attention in coastal systems. Here we assess the temporal development of zoobenthos communities in two areas on the Swedish Baltic Sea coast during 30 years, and relate their development to changes in climate, eutrophication and top-down regulation from fish. Both communities show substantial structural changes, with a decrease in marine polychaetes and species sensitive to increased water temperatures. Concurrently, opportunistic species tolerant to environmental perturbation have increased in abundance. Species composition show a similar temporal development in both communities and significant changes in species composition occurred in both data sets in the late 1980s and early 1990s. The change in species composition was associated with large scale changes in climate (salinity and water temperature) and to the structure of the local fish community, whereas we found no effects of nutrient loading or ambient nutrient concentrations. Our results suggest that these coastal zoobenthos communities have gone through substantial structural changes over the last 30 years, resulting in communities of different species composition with potentially different ecological functions. We hence suggest that the temporal development of coastal zoobenthos communities should be assessed in light of prevailing climatic conditions considering the potential for top-down effects exerted by local fish communities.

Top-Down Regulation, Climate and Multi-Decadal Changes in Coastal Zoobenthos Communities in Two Baltic Sea Areas

PubMed Central

Olsson, Jens; Bergström, Lena; Gårdmark, Anna

2013-01-01

The structure of many marine ecosystems has changed substantially during recent decades, as a result of overexploitation, climate change and eutrophication. Despite of the apparent ecological and economical importance of coastal areas and communities, this aspect has received relatively little attention in coastal systems. Here we assess the temporal development of zoobenthos communities in two areas on the Swedish Baltic Sea coast during 30 years, and relate their development to changes in climate, eutrophication and top-down regulation from fish. Both communities show substantial structural changes, with a decrease in marine polychaetes and species sensitive to increased water temperatures. Concurrently, opportunistic species tolerant to environmental perturbation have increased in abundance. Species composition show a similar temporal development in both communities and significant changes in species composition occurred in both data sets in the late 1980s and early 1990s. The change in species composition was associated with large scale changes in climate (salinity and water temperature) and to the structure of the local fish community, whereas we found no effects of nutrient loading or ambient nutrient concentrations. Our results suggest that these coastal zoobenthos communities have gone through substantial structural changes over the last 30 years, resulting in communities of different species composition with potentially different ecological functions. We hence suggest that the temporal development of coastal zoobenthos communities should be assessed in light of prevailing climatic conditions considering the potential for top-down effects exerted by local fish communities. PMID:23737998

RNA-Seq study reveals genetic responses of diverse wild soybean accessions to increased ozone levels.

PubMed

Waldeck, Nathan; Burkey, Kent; Carter, Thomas; Dickey, David; Song, Qijian; Taliercio, Earl

2017-06-29

Ozone is an air pollutant widely known to cause a decrease in productivity in many plant species, including soybean (Glycine max (L.) Merr). While the response of cultivated soybean to ozone has been studied, very little information is available regarding the ozone response of its wild relatives. Ozone-resistant wild soybean accessions were identified by measuring the response of a genetically diverse group of 66 wild soybean (Glycine soja Zucc. and Sieb.) accessions to elevated ozone levels. RNA-Seq analyses were performed on leaves of different ages from selected ozone-sensitive and ozone-resistant accessions that were subjected to treatment with an environmentally relevant level of ozone. Many more genes responded to elevated ozone in the two ozone-sensitive accessions than in the ozone-resistant accessions. Analyses of the ozone response genes indicated that leaves of different ages responded differently to ozone. Older leaves displayed a consistent reduction in expression of genes involved in photosynthesis in response to ozone, while changes in expression of defense genes dominated younger leaf tissue in response to ozone. As expected, there is a substantial difference between the response of ozone-sensitive and ozone-resistant accessions. Genes associated with photosystem 2 were substantially reduced in expression in response to ozone in the ozone-resistant accessions. A decrease in peptidase inhibitors was one of several responses specific to one of the ozone resistant accessions. The decrease in expression in genes associated with photosynthesis confirms that the photosynthetic apparatus may be an early casualty in response to moderate levels of ozone. A compromise of photosynthesis would substantially impact plant growth and seed production. However, the resistant accessions may preserve their photosynthetic apparatus in response to the ozone levels used in this study. Older leaf tissue of the ozone-resistant accessions showed a unique down-regulation of genes associated with endopeptidase inhibitor activity. This study demonstrates the existence of significant diversity in wild soybean for ozone response. Wild soybean accessions characterized in this study can be used by soybean breeders to enhance ozone tolerance of this important food crop.

pH-Triggered Echogenicity and Contents Release from Liposomes

PubMed Central

2015-01-01

Liposomes are representative lipid nanoparticles widely used for delivering anticancer drugs, DNA fragments, or siRNA to cancer cells. Upon targeting, various internal and external triggers have been used to increase the rate for contents release from the liposomes. Among the internal triggers, decreased pH within the cellular lysosomes has been successfully used to enhance the rate for releasing contents. However, imparting pH sensitivity to liposomes requires the synthesis of specialized lipids with structures that are substantially modified at a reduced pH. Herein, we report an alternative strategy to render liposomes pH sensitive by encapsulating a precursor which generates gas bubbles in situ in response to acidic pH. The disturbance created by the escaping gas bubbles leads to the rapid release of the encapsulated contents from the liposomes. Atomic force microscopic studies indicate that the liposomal structure is destroyed at a reduced pH. The gas bubbles also render the liposomes echogenic, allowing ultrasound imaging. To demonstrate the applicability of this strategy, we have successfully targeted doxorubicin-encapsulated liposomes to the pancreatic ductal carcinoma cells that overexpress the folate receptor on the surface. In response to the decreased pH in the lysosomes, the encapsulated anticancer drug is efficiently released. Contents released from these liposomes are further enhanced by the application of continuous wave ultrasound (1 MHz), resulting in substantially reduced viability for the pancreatic cancer cells (14%). PMID:25271780

pH-triggered echogenicity and contents release from liposomes.

PubMed

Nahire, Rahul; Hossain, Rayat; Patel, Rupa; Paul, Shirshendu; Meghnani, Varsha; Ambre, Avinash H; Gange, Kara N; Katti, Kalpana S; Leclerc, Estelle; Srivastava, D K; Sarkar, Kausik; Mallik, Sanku

2014-11-03

Liposomes are representative lipid nanoparticles widely used for delivering anticancer drugs, DNA fragments, or siRNA to cancer cells. Upon targeting, various internal and external triggers have been used to increase the rate for contents release from the liposomes. Among the internal triggers, decreased pH within the cellular lysosomes has been successfully used to enhance the rate for releasing contents. However, imparting pH sensitivity to liposomes requires the synthesis of specialized lipids with structures that are substantially modified at a reduced pH. Herein, we report an alternative strategy to render liposomes pH sensitive by encapsulating a precursor which generates gas bubbles in situ in response to acidic pH. The disturbance created by the escaping gas bubbles leads to the rapid release of the encapsulated contents from the liposomes. Atomic force microscopic studies indicate that the liposomal structure is destroyed at a reduced pH. The gas bubbles also render the liposomes echogenic, allowing ultrasound imaging. To demonstrate the applicability of this strategy, we have successfully targeted doxorubicin-encapsulated liposomes to the pancreatic ductal carcinoma cells that overexpress the folate receptor on the surface. In response to the decreased pH in the lysosomes, the encapsulated anticancer drug is efficiently released. Contents released from these liposomes are further enhanced by the application of continuous wave ultrasound (1 MHz), resulting in substantially reduced viability for the pancreatic cancer cells (14%).

Large angle solid state position sensitive x-ray detector system

DOEpatents

Kurtz, David S.; Ruud, Clay O.

1998-01-01

A method and apparatus for x-ray measurement of certain properties of a solid material. In distinction to known methods and apparatus, this invention employs a specific fiber-optic bundle configuration, termed a reorganizer, itself known for other uses, for coherently transmitting visible light originating from the scintillation of diffracted x-radiation from the solid material gathered along a substantially one dimensional linear arc, to a two-dimensional photo-sensor array. The two-dimensional photodetector array, with its many closely packed light sensitive pixels, is employed to process the information contained in the diffracted radiation and present the information in the form of a conventional x-ray diffraction spectrum. By this arrangement, the angular range of the combined detector faces may be increased without loss of angular resolution. Further, the prohibitively expensive coupling together of a large number of individual linear diode photodetectors, which would be required to process signals generated by the diffracted radiation, is avoided.

Observed Arctic sea-ice loss directly follows anthropogenic CO2 emission.

PubMed

Notz, Dirk; Stroeve, Julienne

2016-11-11

Arctic sea ice is retreating rapidly, raising prospects of a future ice-free Arctic Ocean during summer. Because climate-model simulations of the sea-ice loss differ substantially, we used a robust linear relationship between monthly-mean September sea-ice area and cumulative carbon dioxide (CO 2 ) emissions to infer the future evolution of Arctic summer sea ice directly from the observational record. The observed linear relationship implies a sustained loss of 3 ± 0.3 square meters of September sea-ice area per metric ton of CO 2 emission. On the basis of this sensitivity, Arctic sea ice will be lost throughout September for an additional 1000 gigatons of CO 2 emissions. Most models show a lower sensitivity, which is possibly linked to an underestimation of the modeled increase in incoming longwave radiation and of the modeled transient climate response. Copyright © 2016, American Association for the Advancement of Science.

Flower-shaped ZnO nanocrystallite aggregates synthesized through a template-free aqueous solution method for dye-sensitized solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Wei-Chen, E-mail: changpeter@iner.gov.tw; Institute of Nuclear Energy Research, Atomic Energy Council, Executive Yuan, 1000 Wenhua Rd., Chiaan Village, Lungtan, Taoyuan 325, Taiwan; Chen, Hung-Shuo

Hierarchically structured flower-shaped aggregates composed of ZnO nanocrystals were synthesized through a template-free aqueous solution method. The synthesized nanocrystallite aggregates were demonstrated to be promising photoanode materials for dye-sensitized solar cells (DSSCs). Compared with commercially available ZnO nanoparticles (ZnONPs), the flower-like aggregates (ZnONFs), each having an overall dimension of 400–600 nm, exhibited similar dye loading but higher light-scattering ability, which led to a substantial increase in the light-harvesting efficiency of resulting cells. The unique morphology of ZnONFs also boosted the absorbed photon-to-electric current generation efficiency. Consequently, DSSCs constructed from ZnONFs showed significantly improved photocurrent and achieved an overall conversion efficiency ofmore » 4.42%, which was 47% higher than that attained by ZnONP-based cells.« less

The Simplexa™ Group A Strep Direct Assay: a sample-to-answer molecular assay for the diagnosis of group A streptococcal pharyngitis.

PubMed

Tabb, Michelle M; Batterman, Hollis J

2016-01-01

The Simplexa™ Group A Strep Direct assay is intended for use on the Integrated Cycler for detection of Group A Streptococcus (GAS) directly from throat swabs that have not undergone nucleic acid extraction. A prospective study of 1352 samples in 4 geographically diverse sites showed an overall prevalence of GAS of 15.4%. The assay demonstrated 97.4% sensitivity and 95.2% specificity versus culture. The positive predictive value compared to culture was 72.7%. However, 46 out of 57 discrepant samples were Group A Strep positive when tested using a bi-directional sequencing method illustrating the increased sensitivity of the assay compared to culture for detection of GAS. Rapid and accurate diagnosis of GAS allows for timely treatment to decrease complications of this prevalent organism that continues to cause substantial morbidity and mortality worldwide.

Simultaneous multiple wavelength upconversion in a core-shell nanoparticle for enhanced near infrared light harvesting in a dye-sensitized solar cell.

PubMed

Yuan, Chunze; Chen, Guanying; Li, Lin; Damasco, Jossana A; Ning, Zhijun; Xing, Hui; Zhang, Tianmu; Sun, Licheng; Zeng, Hao; Cartwright, Alexander N; Prasad, Paras N; Ågren, Hans

2014-10-22

The efficiency of most photovoltaic devices is severely limited by near-infrared (NIR) transmission losses. To alleviate this limitation, a new type of colloidal upconversion nanoparticles (UCNPs), hexagonal core-shell-structured β-NaYbF4:Er(3+)(2%)/NaYF4:Nd(3+)(30%), is developed and explored in this work as an NIR energy relay material for dye-sensitized solar cells (DSSCs). These UCNPs are able to harvest light energy in multiple NIR regions, and subsequently convert the absorbed energy into visible light where the DSSCs strongly absorb. The NIR-insensitive DSSCs show compelling photocurrent increases through binary upconversion under NIR light illumination either at 785 or 980 nm, substantiating efficient energy relay by these UCNPs. The overall conversion efficiency of the DSSCs was improved with the introduction of UCNPs under simulated AM 1.5 solar irradiation.

Process Monitoring Evaluation and Implementation for the Wood Abrasive Machining Process

PubMed Central

Saloni, Daniel E.; Lemaster, Richard L.; Jackson, Steven D.

2010-01-01

Wood processing industries have continuously developed and improved technologies and processes to transform wood to obtain better final product quality and thus increase profits. Abrasive machining is one of the most important of these processes and therefore merits special attention and study. The objective of this work was to evaluate and demonstrate a process monitoring system for use in the abrasive machining of wood and wood based products. The system developed increases the life of the belt by detecting (using process monitoring sensors) and removing (by cleaning) the abrasive loading during the machining process. This study focused on abrasive belt machining processes and included substantial background work, which provided a solid base for understanding the behavior of the abrasive, and the different ways that the abrasive machining process can be monitored. In addition, the background research showed that abrasive belts can effectively be cleaned by the appropriate cleaning technique. The process monitoring system developed included acoustic emission sensors which tended to be sensitive to belt wear, as well as platen vibration, but not loading, and optical sensors which were sensitive to abrasive loading. PMID:22163477

The magnitude and colour of noise in genetic negative feedback systems.

PubMed

Voliotis, Margaritis; Bowsher, Clive G

2012-08-01

The comparative ability of transcriptional and small RNA-mediated negative feedback to control fluctuations or 'noise' in gene expression remains unexplored. Both autoregulatory mechanisms usually suppress the average (mean) of the protein level and its variability across cells. The variance of the number of proteins per molecule of mean expression is also typically reduced compared with the unregulated system, but is almost never below the value of one. This relative variance often substantially exceeds a recently obtained, theoretical lower limit for biochemical feedback systems. Adding the transcriptional or small RNA-mediated control has different effects. Transcriptional autorepression robustly reduces both the relative variance and persistence (lifetime) of fluctuations. Both benefits combine to reduce noise in downstream gene expression. Autorepression via small RNA can achieve more extreme noise reduction and typically has less effect on the mean expression level. However, it is often more costly to implement and is more sensitive to rate parameters. Theoretical lower limits on the relative variance are known to decrease slowly as a measure of the cost per molecule of mean expression increases. However, the proportional increase in cost to achieve substantial noise suppression can be different away from the optimal frontier-for transcriptional autorepression, it is frequently negligible.

[Clinical MR at 3 Tesla: current status].

PubMed

Baudendistel, K T; Heverhagen, J T; Knopp, M V

2004-01-01

Clinical MRI is mostly performed at field strengths up to 1.5 Tesla (T). Recently, approved clinical whole-body MR-systems with a field strength of 3 T became available. Its installation base is more rapidly growing than anticipated. While site requirements and operation of these systems do not differ substantially from systems with lower field strength, there are differences in practical applications. Imaging applications can use the gain in signal-to-noise for increased spatial resolution or gain in speed. This comes at a trade off in increased sensitivity to field inhomogeneities and changes in relaxation times, which lead to changes in image contrast. The benefit of high field for spectroscopy consists in increased signal-to-noise-ratio and improvement in frequency resolution. The increase in energy deposition necessitates the use of special strategies to reduce the specific absorption rate (SAR). This paper summarizes the current state of MR at 3 T.

The development of a Planetary Broadband Seismometer (PBBS) for the Lunar Geophysical Network and the Ocean World

NASA Astrophysics Data System (ADS)

Chui, T. C.; Stone, K. J.; Paik, H. J.; Shelton, D. S.; Kedar, S.; Griggs, C. E.; Moody, M. V.; Hahn, I.; Schmerr, N. C.; Banerdt, W. B.; Neal, C. R.; Vance, S.; Williamson, P. R.

2017-12-01

The NRC decadal survey identified the Lunar Geophysical Network (LGN) as a high-yield New-Frontiers-class mission concept that will place a long-lived and globally distributed network of geophysical instruments on the surface of the Moon to understand the nature and evolution of the lunar interior from the crust to the core. This will allow the examination of the initial stages of planetary differentiation frozen in time some 3-3.5 billion years ago. The objectives of LGN hinge on the capabilities of an ultra-sensitive, very broad-band (VBB) seismometer. We will present a progress report on the development and testing of the PBBS which employs a novel Electrostatic Frequency Reduction (EFR) technique to reduce the resonance frequency of the suspended mass in a seismometer to near zero by a voltage adjustment. We will explain how EFR works, how it can be used to substantially increase the sensitivity of seismic detections and to maintain the sensitivity at the cryogenic temperatures of icy moons in the Ocean World.

Polymers imprinted with PAH mixtures--comparing fluorescence and QCM sensors.

PubMed

Lieberzeit, Peter A; Halikias, Konstantin; Afzal, Adeel; Dickert, Franz L

2008-12-01

Molecular imprinting with binary mixtures of different polycyclic aromatic hydrocarbons (PAH) is a tool for design of chemically highly sensitive layers for detection of these analytes. Sensor responses increase by one order of magnitude compared with layers imprinted with one type of template. Detection limits, e.g. for pyrene, reach down to 30 ng L(-1) in water, as could be observed with a naphthalene and pyrene-imprinted polyurethane. Comparing sensor characteristics obtained by QCM and fluorescence reveals different saturation behaviours indicating that, first, single PAH molecules occupy the interaction centres followed by gradual excimer incorporation at higher concentrations finally leading to substantial quenching, when all accessible cavities are occupied. The plateau in the mass-sensitive measurements suggests that up to 80% of the cavities generated in the MIP are re-occupied. Displacement measurements between chrysene and pyrene revealed that for imprinted layers with very high pyrene sensitivities the signals of both PAH are additive, whereas in materials with lower pyrene uptake the two analytes replace each other in the interaction sites of the polymer.

Global-scale combustion sources of organic aerosols: sensitivity to formation and removal mechanisms

NASA Astrophysics Data System (ADS)

Tsimpidi, Alexandra P.; Karydis, Vlassis A.; Pandis, Spyros N.; Lelieveld, Jos

2017-06-01

Organic compounds from combustion sources such as biomass burning and fossil fuel use are major contributors to the global atmospheric load of aerosols. We analyzed the sensitivity of model-predicted global-scale organic aerosols (OA) to parameters that control primary emissions, photochemical aging, and the scavenging efficiency of organic vapors. We used a computationally efficient module for the description of OA composition and evolution in the atmosphere (ORACLE) of the global chemistry-climate model EMAC (ECHAM/MESSy Atmospheric Chemistry). A global dataset of aerosol mass spectrometer (AMS) measurements was used to evaluate simulated primary (POA) and secondary (SOA) OA concentrations. Model results are sensitive to the emission rates of intermediate-volatility organic compounds (IVOCs) and POA. Assuming enhanced reactivity of semi-volatile organic compounds (SVOCs) and IVOCs with OH substantially improved the model performance for SOA. The use of a hybrid approach for the parameterization of the aging of IVOCs had a small effect on predicted SOA levels. The model performance improved by assuming that freshly emitted organic compounds are relatively hydrophobic and become increasingly hygroscopic due to oxidation.

cWINNOWER algorithm for finding fuzzy dna motifs

NASA Technical Reports Server (NTRS)

Liang, S.; Samanta, M. P.; Biegel, B. A.

2004-01-01

The cWINNOWER algorithm detects fuzzy motifs in DNA sequences rich in protein-binding signals. A signal is defined as any short nucleotide pattern having up to d mutations differing from a motif of length l. The algorithm finds such motifs if a clique consisting of a sufficiently large number of mutated copies of the motif (i.e., the signals) is present in the DNA sequence. The cWINNOWER algorithm substantially improves the sensitivity of the winnower method of Pevzner and Sze by imposing a consensus constraint, enabling it to detect much weaker signals. We studied the minimum detectable clique size qc as a function of sequence length N for random sequences. We found that qc increases linearly with N for a fast version of the algorithm based on counting three-member sub-cliques. Imposing consensus constraints reduces qc by a factor of three in this case, which makes the algorithm dramatically more sensitive. Our most sensitive algorithm, which counts four-member sub-cliques, needs a minimum of only 13 signals to detect motifs in a sequence of length N = 12,000 for (l, d) = (15, 4). Copyright Imperial College Press.

cWINNOWER Algorithm for Finding Fuzzy DNA Motifs

NASA Technical Reports Server (NTRS)

Liang, Shoudan

2003-01-01

The cWINNOWER algorithm detects fuzzy motifs in DNA sequences rich in protein-binding signals. A signal is defined as any short nucleotide pattern having up to d mutations differing from a motif of length l. The algorithm finds such motifs if multiple mutated copies of the motif (i.e., the signals) are present in the DNA sequence in sufficient abundance. The cWINNOWER algorithm substantially improves the sensitivity of the winnower method of Pevzner and Sze by imposing a consensus constraint, enabling it to detect much weaker signals. We studied the minimum number of detectable motifs qc as a function of sequence length N for random sequences. We found that qc increases linearly with N for a fast version of the algorithm based on counting three-member sub-cliques. Imposing consensus constraints reduces qc, by a factor of three in this case, which makes the algorithm dramatically more sensitive. Our most sensitive algorithm, which counts four-member sub-cliques, needs a minimum of only 13 signals to detect motifs in a sequence of length N = 12000 for (l,d) = (15,4).

Accounting for parameter uncertainty in the definition of parametric distributions used to describe individual patient variation in health economic models.

PubMed

Degeling, Koen; IJzerman, Maarten J; Koopman, Miriam; Koffijberg, Hendrik

2017-12-15

Parametric distributions based on individual patient data can be used to represent both stochastic and parameter uncertainty. Although general guidance is available on how parameter uncertainty should be accounted for in probabilistic sensitivity analysis, there is no comprehensive guidance on reflecting parameter uncertainty in the (correlated) parameters of distributions used to represent stochastic uncertainty in patient-level models. This study aims to provide this guidance by proposing appropriate methods and illustrating the impact of this uncertainty on modeling outcomes. Two approaches, 1) using non-parametric bootstrapping and 2) using multivariate Normal distributions, were applied in a simulation and case study. The approaches were compared based on point-estimates and distributions of time-to-event and health economic outcomes. To assess sample size impact on the uncertainty in these outcomes, sample size was varied in the simulation study and subgroup analyses were performed for the case-study. Accounting for parameter uncertainty in distributions that reflect stochastic uncertainty substantially increased the uncertainty surrounding health economic outcomes, illustrated by larger confidence ellipses surrounding the cost-effectiveness point-estimates and different cost-effectiveness acceptability curves. Although both approaches performed similar for larger sample sizes (i.e. n = 500), the second approach was more sensitive to extreme values for small sample sizes (i.e. n = 25), yielding infeasible modeling outcomes. Modelers should be aware that parameter uncertainty in distributions used to describe stochastic uncertainty needs to be reflected in probabilistic sensitivity analysis, as it could substantially impact the total amount of uncertainty surrounding health economic outcomes. If feasible, the bootstrap approach is recommended to account for this uncertainty.

Meta-Analysis of the Relations of Anxiety Sensitivity to the Depressive and Anxiety Disorders

ERIC Educational Resources Information Center

Naragon-Gainey, Kristin

2010-01-01

There is a substantial literature relating the personality trait "anxiety sensitivity" (AS; tendency to fear anxiety-related sensations) and its lower order dimensions to the mood and anxiety (i.e., internalizing) disorders. However, particularly given the disorders' high comorbidity rates, it remains unclear whether AS is broadly related to these…

Variability of temperature sensitivity of extreme precipitation from a regional-to-local impact scale perspective

NASA Astrophysics Data System (ADS)

Schroeer, K.; Kirchengast, G.

2016-12-01

Relating precipitation intensity to temperature is a popular approach to assess potential changes of extreme events in a warming climate. Potential increases in extreme rainfall induced hazards, such as flash flooding, serve as motivation. It has not been addressed whether the temperature-precipitation scaling approach is meaningful on a regional to local level, where the risk of climate and weather impact is dealt with. Substantial variability of temperature sensitivity of extreme precipitation has been found that results from differing methodological assumptions as well as from varying climatological settings of the study domains. Two aspects are consistently found: First, temperature sensitivities beyond the expected consistency with the Clausius-Clapeyron (CC) equation are a feature of short-duration, convective, sub-daily to sub-hourly high-percentile rainfall intensities at mid-latitudes. Second, exponential growth ceases or reverts at threshold temperatures that vary from region to region, as moisture supply becomes limited. Analyses of pooled data, or of single or dispersed stations over large areas make it difficult to estimate the consequences in terms of local climate risk. In this study we test the meaningfulness of the scaling approach from an impact scale perspective. Temperature sensitivities are assessed using quantile regression on hourly and sub-hourly precipitation data from 189 stations in the Austrian south-eastern Alpine region. The observed scaling rates vary substantially, but distinct regional and seasonal patterns emerge. High sensitivity exceeding CC-scaling is seen on the 10-minute scale more than on the hourly scale, in storms shorter than 2 hours duration, and in shoulder seasons, but it is not necessarily a significant feature of the extremes. To be impact relevant, change rates need to be linked to absolute rainfall amounts. We show that high scaling rates occur in lower temperature conditions and thus have smaller effect on absolute precipitation intensities. While reporting of mere percentage numbers can be misleading, scaling studies can add value to process understanding on the local scale, if the factors that influence scaling rates are considered from both a methodological and a physical perspective.

Dementia with Lewy bodies

PubMed Central

McKeith, Ian

2004-01-01

Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia in older people, accounting for 10% to 15% of all cases, it occupies part of a spectrum that includes Parkinson's disease and primary autonomic failure. All these diseases share a neuritic pathology based upon abnormal aggregation of the synaptic protein α-synuciein. It is important to identify DLB patients accurately because they have specific symptoms, impairments, and functional disabilities thai differ from other common dementia syndromes such as Alzheimer's disease, vascular cognitive impairment, and frontotemporal dementia. Clinical diagnostic criteria for DLB have been validated against autopsy, but fail to detect a substantial minority of cases with atypical presentations that are often due to the presence of mixed pathology. DLB patients frequently have severe neuroleptic sensitivity reactions, which are associated with significantly increased morbidity and mortality. Cholinesterase inhibitor treatment is usually well tolerated and substantially improves cognitive and neuropsychiatrie symptoms. Although virtually unrecognized 20 years ago, DLB could within this decade become one of the most treatable neurodegenerative disorders of late life. PMID:22033743

Nanocrystalline High-Entropy Alloys: A New Paradigm in High-Temperature Strength and Stability.

PubMed

Zou, Yu; Wheeler, Jeffrey M; Ma, Huan; Okle, Philipp; Spolenak, Ralph

2017-03-08

Metals with nanometer-scale grains or nanocrystalline metals exhibit high strengths at ambient conditions, yet their strengths substantially decrease with increasing temperature, rendering them unsuitable for usage at high temperatures. Here, we show that a nanocrystalline high-entropy alloy (HEA) retains an extraordinarily high yield strength over 5 GPa up to 600 °C, 1 order of magnitude higher than that of its coarse-grained form and 5 times higher than that of its single-crystalline equivalent. As a result, such nanostructured HEAs reveal strengthening figures of merit-normalized strength by the shear modulus above 1/50 and strength-to-density ratios above 0.4 MJ/kg, which are substantially higher than any previously reported values for nanocrystalline metals in the same homologous temperature range, as well as low strain-rate sensitivity of ∼0.005. Nanocrystalline HEAs with these properties represent a new class of nanomaterials for high-stress and high-temperature applications in aerospace, civilian infrastructure, and energy sectors.

Para hydrogen equilibration in the atmospheres of the outer planets

NASA Technical Reports Server (NTRS)

Conrath, Barney J.

1986-01-01

The thermodynamic behavior of the atmospheres of the Jovian planets is strongly dependent on the extent to which local thermal equilibration of the ortho and para states of molecular hydrogen is achieved. Voyager IRIS data from Jupiter imply substantial departures of the para hydrogen fraction from equilibrium in the upper troposphere at low latitudes, but with values approaching equilibrium at higher latitudes. Data from Saturn are less sensitive to the orth-para ratio, but suggest para hydrogen fractions near the equilibrium value. Above approximately the 200 K temperature level, para hydrogen conversion can enhance the efficiency of convection, resulting in a substantial increase in overturning times on all of the outer planets. Currently available data cannot definitively establish the ortho-para ratios in the atmospheres of Uranus and Neptune, but suggest values closer to local equilibrium than to the 3.1 normal ratio. Modeling of sub-millimeter wavelength measurements of these planets suggest thermal structures with frozen equilibrium lapse rates in their convective regions.

The influence of childhood traffic-related air pollution exposure on asthma, allergy and sensitization: a systematic review and a meta-analysis of birth cohort studies.

PubMed

Bowatte, G; Lodge, C; Lowe, A J; Erbas, B; Perret, J; Abramson, M J; Matheson, M; Dharmage, S C

2015-03-01

The impact of early childhood traffic-related air pollution (TRAP) exposure on development of asthma and allergies remains unclear. Birth cohort studies are the best available study design to answer this question, but the evidence from such studies has not been synthesized to date. We conducted a systematic review and meta-analyses of published birth cohort studies to understand the association between early childhood TRAP exposure, and subsequent asthma, allergies and sensitization. Increased longitudinal childhood exposure to PM2.5 and black carbon was associated with increasing risk of subsequent asthma in childhood (PM2.5 : OR 1.14, 95%CI 1.00 to 1.30 per 2 μg/m(3) and black carbon: OR 1.20, 95%CI 1.05 to 1.38 per 1 × 10(-5) m(-1) ). Also, early childhood exposure to TRAP was associated with development of asthma across childhood up to 12 years of age. The magnitude of these associations increased with age, and the pattern was prominent for PM2.5 . Increasing exposure to PM2.5 was associated with sensitization to both aero- and food allergens. There was some evidence that TRAP was associated with eczema and hay fever. In summary, exposure to TRAP was related to asthma and allergic diseases. However, the substantial variability across studies warrants long-term birth cohort studies with regular repeated follow-ups to confirm these findings. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Extended Monopole antenna Array with individual Shield (EMAS) coil: An improved monopole antenna design for brain imaging at 7 tesla MRI.

PubMed

Woo, Myung-Kyun; Hong, Suk-Min; Lee, Jongho; Kang, Chang-Ki; Park, Sung-Yeon; Son, Young-Don; Kim, Young-Bo; Cho, Zang-Hee

2016-06-01

To propose a new Extended Monopole antenna Array with individual Shields (EMAS) coil that improves the B1 field coverage and uniformity along the z-direction. To increase the spatial coverage of Monopole antenna Array (MA) coil, each monopole antenna was shielded and extended in length. Performance of this new coil, which is referred to as EMAS coil, was compared with the original MA coil and an Extended Monopole antenna Array coil with no shield (EMA). For comparison, flip angle, signal-to-noise ratio (SNR), and receive sensitivity maps were measured at multiple regions of interest (ROIs) in the brain. The EMAS coil demonstrated substantially larger flip angle and receive sensitivity than the MA and EMA coils in the inferior aspect of the brain. In the brainstem ROI, for example, the flip angle in the EMAS coil was increased by 45.5% (or 60.0%) and the receive sensitivity was increased by 26.9% (or 14.9%), resulting in an SNR gain of 84.8% (or 76.3%) when compared with the MA coil (or EMA). The EMAS coil provided 25.7% (or 24.4%) more uniform B1+ field distribution compared with the MA (or EMA) coil in sagittal. The EMAS coil successfully extended the imaging volume in lower part of the brain. Magn Reson Med 75:2566-2572, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

CPRA for allocation of kidneys in the US: More candidates ≥98% CPRA, lower positive crossmatch rates and improved transplant rates for sensitized patients.

PubMed

Baxter-Lowe, Lee Ann; Kucheryavaya, Anna; Tyan, Dolly; Reinsmoen, Nancy

2016-05-01

In 2009 calculated panel reactive antibody (CPRA) replaced PRA as the metric for HLA sensitization in the US kidney allocation system. During the next four years, registrants with at least one unacceptable antigen increased (34-40%) and registrants with ≥98% PRA/CPRA increased from 7% to 9% of the waitlist. These changes were accompanied by a reduction in kidney offers refused for positive crossmatch: 14,137 (1.7%) in 2009 and 3,310 in 2013 (0.4%). Registrants with ≥98% PRA/CPRA had highest rates of refusal but also showed substantial improvement (20% in 2009 vs 8% in 2013). For registrants with ≥98% PRA/CPRA, 45% of accepted offers in 2009 were not transplanted into the intended recipient compared to 11% in 2013. Transplant rates remained low for these patients (∼50/1000 active patient-years), but rates improved for patients with 80-97% PRA/CPRA (223/1000 active patient-years in 2009 vs 354/1000 in 2013). In 2013, 40% regraft candidates had CPRA ≥98% compared to 4% of primary graft candidates. More females than males were ≥98% CPRA (14% vs 7%) and more females had CPRA above 0 (50% vs 28%). In the CPRA era, listing of unacceptable antigens increased, positive crossmatches were diminished and transplant rates for sensitized patients improved. Copyright © 2016 American Society for Histocompatibility and Immunogenetics. All rights reserved.

Modelling predicts that tolerance to drought during reproductive development will be required for high yield potential and stability of wheat in Europe

NASA Astrophysics Data System (ADS)

Semenov, Mikhail A.; Stratonovitch, Pierre; Paul, Matthew J.

2017-04-01

Short periods of extreme weather, such as a spell of high temperature or drought during a sensitive stage of development, could result in substantial yield losses due to reduction in grain number and grain size. In a modelling study (Stratonovitch & Semenov 2015), heat tolerance around flowering in wheat was identified as a key trait for increased yield potential in Europe under climate change. Ji et all (Ji et al. 2010) demonstrated cultivar specific responses of yield to drought stress around flowering in wheat. They hypothesised that carbohydrate supply to anthers may be the key in maintaining pollen fertility and grain number in wheat. It was shown in (Nuccio et al. 2015) that genetically modified varieties of maize that increase the concentration of sucrose in ear spikelets, performed better under non-drought and drought conditions in field experiments. The objective of this modelling study was to assess potential benefits of tolerance to drought during reproductive development for wheat yield potential and yield stability across Europe. We used the Sirius wheat model to optimise wheat ideotypes for 2050 (HadGEM2, RCP8.5) climate scenarios at selected European sites. Eight cultivar parameters were optimised to maximise mean yields, including parameters controlling phenology, canopy growth and water limitation. At those sites where water could be limited, ideotypes sensitive to drought produced substantially lower mean yields and higher yield variability compare with tolerant ideotypes. Therefore, tolerance to drought during reproductive development is likely to be required for wheat cultivars optimised for the future climate in Europe in order to achieve high yield potential and yield stability.

Neuronal hyperexcitability in the ventral posterior thalamus of neuropathic rats: modality selective effects of pregabalin

PubMed Central

Dickenson, Anthony H.

2016-01-01

Neuropathic pain represents a substantial clinical challenge; understanding the underlying neural mechanisms and back-translation of therapeutics could aid targeting of treatments more effectively. The ventral posterior thalamus (VP) is the major termination site for the spinothalamic tract and relays nociceptive activity to the somatosensory cortex; however, under neuropathic conditions, it is unclear how hyperexcitability of spinal neurons converges onto thalamic relays. This study aimed to identify neural substrates of hypersensitivity and the influence of pregabalin on central processing. In vivo electrophysiology was performed to record from VP wide dynamic range (WDR) and nociceptive-specific (NS) neurons in anesthetized spinal nerve-ligated (SNL), sham-operated, and naive rats. In neuropathic rats, WDR neurons had elevated evoked responses to low- and high-intensity punctate mechanical stimuli, dynamic brushing, and innocuous and noxious cooling, but less so to heat stimulation, of the receptive field. NS neurons in SNL rats also displayed increased responses to noxious punctate mechanical stimulation, dynamic brushing, noxious cooling, and noxious heat. Additionally, WDR, but not NS, neurons in SNL rats exhibited substantially higher rates of spontaneous firing, which may correlate with ongoing pain. The ratio of WDR-to-NS neurons was comparable between SNL and naive/sham groups, suggesting relatively few NS neurons gain sensitivity to low-intensity stimuli leading to a “WDR phenotype.” After neuropathy was induced, the proportion of cold-sensitive WDR and NS neurons increased, supporting the suggestion that changes in frequency-dependent firing and population coding underlie cold hypersensitivity. In SNL rats, pregabalin inhibited mechanical and heat responses but not cold-evoked or elevated spontaneous activity. PMID:27098028

Neuronal hyperexcitability in the ventral posterior thalamus of neuropathic rats: modality selective effects of pregabalin.

PubMed

Patel, Ryan; Dickenson, Anthony H

2016-07-01

Neuropathic pain represents a substantial clinical challenge; understanding the underlying neural mechanisms and back-translation of therapeutics could aid targeting of treatments more effectively. The ventral posterior thalamus (VP) is the major termination site for the spinothalamic tract and relays nociceptive activity to the somatosensory cortex; however, under neuropathic conditions, it is unclear how hyperexcitability of spinal neurons converges onto thalamic relays. This study aimed to identify neural substrates of hypersensitivity and the influence of pregabalin on central processing. In vivo electrophysiology was performed to record from VP wide dynamic range (WDR) and nociceptive-specific (NS) neurons in anesthetized spinal nerve-ligated (SNL), sham-operated, and naive rats. In neuropathic rats, WDR neurons had elevated evoked responses to low- and high-intensity punctate mechanical stimuli, dynamic brushing, and innocuous and noxious cooling, but less so to heat stimulation, of the receptive field. NS neurons in SNL rats also displayed increased responses to noxious punctate mechanical stimulation, dynamic brushing, noxious cooling, and noxious heat. Additionally, WDR, but not NS, neurons in SNL rats exhibited substantially higher rates of spontaneous firing, which may correlate with ongoing pain. The ratio of WDR-to-NS neurons was comparable between SNL and naive/sham groups, suggesting relatively few NS neurons gain sensitivity to low-intensity stimuli leading to a "WDR phenotype." After neuropathy was induced, the proportion of cold-sensitive WDR and NS neurons increased, supporting the suggestion that changes in frequency-dependent firing and population coding underlie cold hypersensitivity. In SNL rats, pregabalin inhibited mechanical and heat responses but not cold-evoked or elevated spontaneous activity. Copyright © 2016 the American Physiological Society.

Combined effects of endurance training and dietary unsaturated fatty acids on physical performance, fat oxidation and insulin sensitivity.

PubMed

Boss, Andreas; Lecoultre, Virgile; Ruffieux, Christiane; Tappy, Luc; Schneiter, Philippe

2010-04-01

Endurance training improves exercise performance and insulin sensitivity, and these effects may be in part mediated by an enhanced fat oxidation. Since n-3 and n-9 unsaturated fatty acids may also increase fat oxidation, we hypothesised that a diet enriched in these fatty acids may enhance the effects of endurance training on exercise performance, insulin sensitivity and fat oxidation. To assess this hypothesis, sixteen normal-weight sedentary male subjects were randomly assigned to an isoenergetic diet enriched with fish and olive oils (unsaturated fatty acid group (UFA): 52 % carbohydrates, 34 % fat (12 % SFA, 12 % MUFA, 5 % PUFA), 14 % protein), or a control diet (control group (CON): 62 % carbohydrates, 24 % fat (12 % SFA, 6 % MUFA, 2 % PUFA), 14 % protein) and underwent a 10 d gradual endurance training protocol. Exercise performance was evaluated by measuring VO2max and the time to exhaustion during a cycling exercise at 80 % VO2max; glucose homeostasis was assessed after ingestion of a test meal. Fat oxidation was assessed by indirect calorimetry at rest and during an exercise at 50 % VO2max. Training significantly increased time to exhaustion, but not VO2max, and lowered incremental insulin area under the curve after the test meal, indicating improved insulin sensitivity. Those effects were, however, of similar magnitude in UFA and CON. Fat oxidation tended to increase in UFA, but not in CON. This difference was, however, not significant. It is concluded that a diet enriched with fish- and olive oil does not substantially enhance the effects of a short-term endurance training protocol in healthy young subjects.

High fat diet-fed obese rats are highly sensitive to doxorubicin-induced cardiotoxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitra, Mayurranjan S.; Donthamsetty, Shashikiran; White, Brent

Often, chemotherapy by doxorubicin (Adriamycin) is limited due to life threatening cardiotoxicity in patients during and posttherapy. Recently, we have shown that moderate diet restriction remarkably protects against doxorubicin-induced cardiotoxicity. This cardioprotection is accompanied by decreased cardiac oxidative stress and triglycerides and increased cardiac fatty-acid oxidation, ATP synthesis, and upregulated JAK/STAT3 pathway. In the current study, we investigated whether a physiological intervention by feeding 40% high fat diet (HFD), which induces obesity in male Sprague-Dawley rats (250-275 g), sensitizes to doxorubicin-induced cardiotoxicity. A LD{sub 10} dose (8 mg doxorubicin/kg, ip) administered on day 43 of the HFD feeding regimen ledmore » to higher cardiotoxicity, cardiac dysfunction, lipid peroxidation, and 80% mortality in the obese (OB) rats in the absence of any significant renal or hepatic toxicity. Doxorubicin toxicokinetics studies revealed no change in accumulation of doxorubicin and doxorubicinol (toxic metabolite) in the normal diet-fed (ND) and OB hearts. Mechanistic studies revealed that OB rats are sensitized due to: (1) higher oxyradical stress leading to upregulation of uncoupling proteins 2 and 3, (2) downregulation of cardiac peroxisome proliferators activated receptor-{alpha}, (3) decreased plasma adiponectin levels, (4) decreased cardiac fatty-acid oxidation (666.9 {+-} 14.0 nmol/min/g heart in ND versus 400.2 {+-} 11.8 nmol/min/g heart in OB), (5) decreased mitochondrial AMP-{alpha}2 protein kinase, and (6) 86% drop in cardiac ATP levels accompanied by decreased ATP/ADP ratio after doxorubicin administration. Decreased cardiac erythropoietin and increased SOCS3 further downregulated the cardioprotective JAK/STAT3 pathway. In conclusion, HFD-induced obese rats are highly sensitized to doxorubicin-induced cardiotoxicity by substantially downregulating cardiac mitochondrial ATP generation, increasing oxidative stress and downregulating the JAK/STAT3 pathway.« less

Exploring productivity and collaboration in Australian Indigenous health research, 1995-2008.

PubMed

Rumbold, Alice R; Cunningham, Joan; Purbrick, Brydie; Lewis, Jenny M

2013-11-08

Building research capacity in Indigenous health has been recognised as integral in efforts to reduce the significant health disparities between Indigenous and other Australian populations. The past few decades have seen substantial changes in funding policy for Australian Indigenous health research, including increases in overall expenditure and a greater focus on collaborative and priority-driven research. However, whether these policy shifts have resulted in any change to the structure of the research workforce in this field is unclear. We examine research publications in Australian Indigenous health from 1995-2008 to explore trends in publication output, key themes investigated, and research collaborations. A comprehensive literature search was undertaken to identify research publications about Australian Indigenous health from 1995-2008. Abstracts of all publications identified were reviewed by two investigators for relevance. Eligible publications were classified according to key themes. Social network analyses of co-authorship patterns were used to examine collaboration in the periods 1995-1999, 2000-2004 and 2005-2008. Nine hundred and fifty three publications were identified. Over time, the number of publications per year increased, particularly after 2005, and there was a substantial increase in assessment of health service-related issues. Network analyses revealed a highly collaborative core group of authors responsible for the majority of outputs, in addition to a series of smaller separate groups. In the first two periods there was a small increase in the overall network size (from n = 583 to n = 642 authors) due to growth in collaborations around the core. In the last period, the network size increased considerably (n = 1,083), largely due to an increase in the number and size of separate groups. The general size of collaborations also increased in this period. In the past few decades there has been substantial development of the research workforce in Indigenous health, characterised by an increase in authors and outputs, a greater focus on some identified priority areas and sustained growth in collaborations. This has occurred in conjunction with significant changes to funding policy for Indigenous health research, suggesting that both productivity and collaboration may be sensitive to reform, including the provision of dedicated funding.

Selective killing of proinflammatory synovial fibroblasts via activation of transient receptor potential ankyrin (TRPA1).

PubMed

Lowin, Torsten; Bleck, Janna; Schneider, Matthias; Pongratz, Georg

2018-05-24

Studies in rheumatoid arthritis synovial fibroblasts (RASF) demonstrated the expression of several transient receptor potential channels (TRP) such as TRPV1, TRPV2, TRPV4, TRPA1 and TRPM8. Upon ligation, these receptors increase intracellular calcium but they have also been linked to modulation of inflammation in several cell types. TNF was shown to increase the expression of TRPA1, the receptor for mustard oil and environmental poisons in SF, but the functional consequences have not been investigated yet. TRPA1 was detected by immunocytochemistry, western blot and cell-based ELISA. Calcium measurements were conducted in a multimode reader. Cell viability was assessed by quantification of lactate dehydrogenase (LDH) in culture supernatants and "RealTime-Glo" luminescent assays. IL-6 and IL-8 production by SF was quantified by ELISA. Proliferation was determined by cell titer blue incorporation. After 72 h, mimicking proinflammatory conditions by the innate cytokine TNF up-regulated TRPA1 protein levels in RASF which was accompanied by increased sensitivity to TRPA1 agonists AITC and polygodial. Under unstimulated conditions, polygodial elicited calcium flux only in the highest concentrations used (50 µM and 25 µM). TNF preincubation substantially lowered the activation threshold for polygodial (from 25 µM to 1 µM). In the absence of TNF pre-stimulation, only polygodial in high concentrations was able to reduce viability of synovial fibroblasts as determined by a real-time viability assay. However, following TNF preincubation, stimulation of TRPA1 led to a fast (<30 min) viability loss by necrosis of synovial fibroblasts. TRPA1 activation was also associated with decreased proliferation of RASFs, an effect that was also substantially enhanced by TNF preincubation. On the functional level, IL-6 and IL-8 production was attenuated by the TRPA1 antagonist A967079 but also polygodial, although the latter mediated this effect by reducing cell viability. Simulating inflamed conditions by preincubation of synovial fibroblasts with TNF up-regulates and sensitizes TRPA1. Subsequent activation of TRPA1 increases calcium flux and substantially reduces cell viability by inducing necrosis. Since TRPA1 agonists in the lower concentration range only show effects in TNF-stimulated RASF, this cation channel might be an attractive therapeutic target in chronic inflammation to selectively reduce the activity of proinflammatory SF in the joint. Copyright © 2018 Elsevier Inc. All rights reserved.

Evaluation of pH-sensitive fusogenic polymer-modified liposomes co-loaded with antigen and α-galactosylceramide as an anti-tumor vaccine

PubMed Central

OKAZAKI, Seiji; IWASAKI, Tadashi; YUBA, Eiji; WATARAI, Shinobu

2017-01-01

pH-Sensitive fusogenic polymer-modified (pH-sensitive) liposomes co-loaded with tumor model antigen, ovalbumin (OVA), and adjuvant, α-galactosylceramide (α-GalCer) were fabricated and administered subcutaneously into mice. The ability of pH-sensitive liposomes containing OVA and α-GalCer to stimulate cellular and humoral immune responses in vivo was compared with OVA-encapsulating pH-sensitive liposomes as well as with OVA alone. After immunization, significant OVA-specific antibodies were detected in the serum. When sera were analyzed for isotype distribution, antigen-specific IgG1 antibody responses were noted in mice immunized with OVA alone, whereas immunization with OVA-containing pH-sensitive liposomes and with pH-sensitive liposomes containing OVA and α-GalCer resulted in the induction of OVA-specific IgG1 and IgG2b antibody responses. Moreover, more substantial production of IFN-γ and IL-4 was demonstrated in spleen cells from mice immunized with pH-sensitive liposomes having OVA and α-GalCer than OVA-containing pH-sensitive liposomes in vitro. Spleen cells from the immunized mice showed strong cytotoxic activity against E.G7-OVA tumor cells. In addition, prophylactic vaccination efficacy against tumor formation was evaluated. In all mice immunized with pH-sensitive liposomes having OVA and α-GalCer, immunization provided substantial protection from tumor formation. The therapeutic efficacy of pH-sensitive liposomes containing OVA and α-GalCer against already established E.G7-OVA tumors was also investigated. Tumor growth was reduced significantly in all mice treated with pH-sensitive liposomes having OVA and α-GalCer. The provided evidence on the advantage of antigen and α-GalCer co-encapsulation into pH-sensitive liposomes should be considered in the design of future cancer vaccines for prophylactic and therapeutic purposes. PMID:29311431

Evaluation of pH-sensitive fusogenic polymer-modified liposomes co-loaded with antigen and α-galactosylceramide as an anti-tumor vaccine.

PubMed

Okazaki, Seiji; Iwasaki, Tadashi; Yuba, Eiji; Watarai, Shinobu

2018-02-09

pH-Sensitive fusogenic polymer-modified (pH-sensitive) liposomes co-loaded with tumor model antigen, ovalbumin (OVA), and adjuvant, α-galactosylceramide (α-GalCer) were fabricated and administered subcutaneously into mice. The ability of pH-sensitive liposomes containing OVA and α-GalCer to stimulate cellular and humoral immune responses in vivo was compared with OVA-encapsulating pH-sensitive liposomes as well as with OVA alone. After immunization, significant OVA-specific antibodies were detected in the serum. When sera were analyzed for isotype distribution, antigen-specific IgG1 antibody responses were noted in mice immunized with OVA alone, whereas immunization with OVA-containing pH-sensitive liposomes and with pH-sensitive liposomes containing OVA and α-GalCer resulted in the induction of OVA-specific IgG1 and IgG2b antibody responses. Moreover, more substantial production of IFN-γ and IL-4 was demonstrated in spleen cells from mice immunized with pH-sensitive liposomes having OVA and α-GalCer than OVA-containing pH-sensitive liposomes in vitro. Spleen cells from the immunized mice showed strong cytotoxic activity against E.G7-OVA tumor cells. In addition, prophylactic vaccination efficacy against tumor formation was evaluated. In all mice immunized with pH-sensitive liposomes having OVA and α-GalCer, immunization provided substantial protection from tumor formation. The therapeutic efficacy of pH-sensitive liposomes containing OVA and α-GalCer against already established E.G7-OVA tumors was also investigated. Tumor growth was reduced significantly in all mice treated with pH-sensitive liposomes having OVA and α-GalCer. The provided evidence on the advantage of antigen and α-GalCer co-encapsulation into pH-sensitive liposomes should be considered in the design of future cancer vaccines for prophylactic and therapeutic purposes.

Apparatus for measuring high frequency currents

NASA Technical Reports Server (NTRS)

Hagmann, Mark J. (Inventor); Sutton, John F. (Inventor)

2003-01-01

An apparatus for measuring high frequency currents includes a non-ferrous core current probe that is coupled to a wide-band transimpedance amplifier. The current probe has a secondary winding with a winding resistance that is substantially smaller than the reactance of the winding. The sensitivity of the current probe is substantially flat over a wide band of frequencies. The apparatus is particularly useful for measuring exposure of humans to radio frequency currents.

The Role of PP2A Methylation in Susceptibility and Resistance to TBI and AD-Induced Neurodegeneration

DTIC Science & Technology

2013-09-01

will exert similar effects on shockwave- induced impairments. This effort has required a substantial investment in developing equipment and testing...substantial investment to identify suitable shockwave exposure conditions, confirm biomechanical parameters, and to assess the biochemical...consequences. One of the previously unforeseen benefits of this investment may be the identification of PME-1 over expressing mice as a sensitized background

Cosmic distribution of highly ionized metals and their physical conditions in the EAGLE simulations

NASA Astrophysics Data System (ADS)

Rahmati, Alireza; Schaye, Joop; Crain, Robert A.; Oppenheimer, Benjamin D.; Schaller, Matthieu; Theuns, Tom

2016-06-01

We study the distribution and evolution of highly ionized intergalactic metals in the Evolution and Assembly of Galaxies and their Environment (EAGLE) cosmological, hydrodynamical simulations. EAGLE has been shown to reproduce a wide range of galaxy properties while its subgrid feedback was calibrated without considering gas properties. We compare the predictions for the column density distribution functions (CDDFs) and cosmic densities of Si IV, C IV, N V, O VI and Ne VIII absorbers with observations at redshift z = 0 to ˜6 and find reasonable agreement, although there are some differences. We show that the typical physical densities of the absorbing gas increase with column density and redshift, but decrease with the ionization energy of the absorbing ion. The typical metallicity increases with both column density and time. The fraction of collisionally ionized metal absorbers increases with time and ionization energy. While our results show little sensitivity to the presence or absence of AGN feedback, increasing/decreasing the efficiency of stellar feedback by a factor of 2 substantially decreases/increases the CDDFs and the cosmic densities of the metal ions. We show that the impact of the efficiency of stellar feedback on the CDDFs and cosmic densities is largely due to its effect on the metal production rate. However, the temperatures of the metal absorbers, particularly those of strong O VI, are directly sensitive to the strength of the feedback.

Assessing climate change impacts, benefits of mitigation, and uncertainties on major global forest regions under multiple socioeconomic and emissions scenarios

DOE PAGES

Kim, John B.; Monier, Erwan; Sohngen, Brent; ...

2017-03-28

We analyze a set of simulations to assess the impact of climate change on global forests where MC2 dynamic global vegetation model (DGVM) was run with climate simulations from the MIT Integrated Global System Model-Community Atmosphere Model (IGSM-CAM) modeling framework. The core study relies on an ensemble of climate simulations under two emissions scenarios: a business-as-usual reference scenario (REF) analogous to the IPCC RCP8.5 scenario, and a greenhouse gas mitigation scenario, called POL3.7, which is in between the IPCC RCP2.6 and RCP4.5 scenarios, and is consistent with a 2 °C global mean warming from pre-industrial by 2100. Evaluating the outcomesmore » of both climate change scenarios in the MC2 model shows that the carbon stocks of most forests around the world increased, with the greatest gains in tropical forest regions. Temperate forest regions are projected to see strong increases in productivity offset by carbon loss to fire. The greatest cost of mitigation in terms of effects on forest carbon stocks are projected to be borne by regions in the southern hemisphere. We compare three sources of uncertainty in climate change impacts on the world’s forests: emissions scenarios, the global system climate response (i.e. climate sensitivity), and natural variability. The role of natural variability on changes in forest carbon and net primary productivity (NPP) is small, but it is substantial for impacts of wildfire. Forest productivity under the REF scenario benefits substantially from the CO 2 fertilization effect and that higher warming alone does not necessarily increase global forest carbon levels. Finally, our analysis underlines why using an ensemble of climate simulations is necessary to derive robust estimates of the benefits of greenhouse gas mitigation. It also demonstrates that constraining estimates of climate sensitivity and advancing our understanding of CO 2 fertilization effects may considerably reduce the range of projections.« less

Expected lifetime numbers and costs of fractures in postmenopausal women with and without osteoporosis in Germany: a discrete event simulation model.

PubMed

Bleibler, Florian; Rapp, Kilian; Jaensch, Andrea; Becker, Clemens; König, Hans-Helmut

2014-06-30

Osteoporotic fractures cause a large health burden and substantial costs. This study estimated the expected fracture numbers and costs for the remaining lifetime of postmenopausal women in Germany. A discrete event simulation (DES) model which tracks changes in fracture risk due to osteoporosis, a previous fracture or institutionalization in a nursing home was developed. Expected lifetime fracture numbers and costs per capita were estimated for postmenopausal women (aged 50 and older) at average osteoporosis risk (AOR) and for those never suffering from osteoporosis. Direct and indirect costs were modeled. Deterministic univariate and probabilistic sensitivity analyses were conducted. The expected fracture numbers over the remaining lifetime of a 50 year old woman with AOR for each fracture type (% attributable to osteoporosis) were: hip 0.282 (57.9%), wrist 0.229 (18.2%), clinical vertebral 0.206 (39.2%), humerus 0.147 (43.5%), pelvis 0.105 (47.5%), and other femur 0.033 (52.1%). Expected discounted fracture lifetime costs (excess cost attributable to osteoporosis) per 50 year old woman with AOR amounted to € 4,479 (€ 1,995). Most costs were accrued in the hospital € 1,743 (€ 751) and long-term care sectors € 1,210 (€ 620). Univariate sensitivity analysis resulted in percentage changes between -48.4% (if fracture rates decreased by 2% per year) and +83.5% (if fracture rates increased by 2% per year) compared to base case excess costs. Costs for women with osteoporosis were about 3.3 times of those never getting osteoporosis (€ 7,463 vs. € 2,247), and were markedly increased for women with a previous fracture. The results of this study indicate that osteoporosis causes a substantial share of fracture costs in postmenopausal women, which strongly increase with age and previous fractures.

Assessing climate change impacts, benefits of mitigation, and uncertainties on major global forest regions under multiple socioeconomic and emissions scenarios

NASA Astrophysics Data System (ADS)

Kim, John B.; Monier, Erwan; Sohngen, Brent; Pitts, G. Stephen; Drapek, Ray; McFarland, James; Ohrel, Sara; Cole, Jefferson

2017-04-01

We analyze a set of simulations to assess the impact of climate change on global forests where MC2 dynamic global vegetation model (DGVM) was run with climate simulations from the MIT Integrated Global System Model-Community Atmosphere Model (IGSM-CAM) modeling framework. The core study relies on an ensemble of climate simulations under two emissions scenarios: a business-as-usual reference scenario (REF) analogous to the IPCC RCP8.5 scenario, and a greenhouse gas mitigation scenario, called POL3.7, which is in between the IPCC RCP2.6 and RCP4.5 scenarios, and is consistent with a 2 °C global mean warming from pre-industrial by 2100. Evaluating the outcomes of both climate change scenarios in the MC2 model shows that the carbon stocks of most forests around the world increased, with the greatest gains in tropical forest regions. Temperate forest regions are projected to see strong increases in productivity offset by carbon loss to fire. The greatest cost of mitigation in terms of effects on forest carbon stocks are projected to be borne by regions in the southern hemisphere. We compare three sources of uncertainty in climate change impacts on the world’s forests: emissions scenarios, the global system climate response (i.e. climate sensitivity), and natural variability. The role of natural variability on changes in forest carbon and net primary productivity (NPP) is small, but it is substantial for impacts of wildfire. Forest productivity under the REF scenario benefits substantially from the CO2 fertilization effect and that higher warming alone does not necessarily increase global forest carbon levels. Our analysis underlines why using an ensemble of climate simulations is necessary to derive robust estimates of the benefits of greenhouse gas mitigation. It also demonstrates that constraining estimates of climate sensitivity and advancing our understanding of CO2 fertilization effects may considerably reduce the range of projections.

Expected lifetime numbers and costs of fractures in postmenopausal women with and without osteoporosis in Germany: a discrete event simulation model

PubMed Central

2014-01-01

Background Osteoporotic fractures cause a large health burden and substantial costs. This study estimated the expected fracture numbers and costs for the remaining lifetime of postmenopausal women in Germany. Methods A discrete event simulation (DES) model which tracks changes in fracture risk due to osteoporosis, a previous fracture or institutionalization in a nursing home was developed. Expected lifetime fracture numbers and costs per capita were estimated for postmenopausal women (aged 50 and older) at average osteoporosis risk (AOR) and for those never suffering from osteoporosis. Direct and indirect costs were modeled. Deterministic univariate and probabilistic sensitivity analyses were conducted. Results The expected fracture numbers over the remaining lifetime of a 50 year old woman with AOR for each fracture type (% attributable to osteoporosis) were: hip 0.282 (57.9%), wrist 0.229 (18.2%), clinical vertebral 0.206 (39.2%), humerus 0.147 (43.5%), pelvis 0.105 (47.5%), and other femur 0.033 (52.1%). Expected discounted fracture lifetime costs (excess cost attributable to osteoporosis) per 50 year old woman with AOR amounted to €4,479 (€1,995). Most costs were accrued in the hospital €1,743 (€751) and long-term care sectors €1,210 (€620). Univariate sensitivity analysis resulted in percentage changes between -48.4% (if fracture rates decreased by 2% per year) and +83.5% (if fracture rates increased by 2% per year) compared to base case excess costs. Costs for women with osteoporosis were about 3.3 times of those never getting osteoporosis (€7,463 vs. €2,247), and were markedly increased for women with a previous fracture. Conclusion The results of this study indicate that osteoporosis causes a substantial share of fracture costs in postmenopausal women, which strongly increase with age and previous fractures. PMID:24981316

Assessing climate change impacts, benefits of mitigation, and uncertainties on major global forest regions under multiple socioeconomic and emissions scenarios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, John B.; Monier, Erwan; Sohngen, Brent

We analyze a set of simulations to assess the impact of climate change on global forests where MC2 dynamic global vegetation model (DGVM) was run with climate simulations from the MIT Integrated Global System Model-Community Atmosphere Model (IGSM-CAM) modeling framework. The core study relies on an ensemble of climate simulations under two emissions scenarios: a business-as-usual reference scenario (REF) analogous to the IPCC RCP8.5 scenario, and a greenhouse gas mitigation scenario, called POL3.7, which is in between the IPCC RCP2.6 and RCP4.5 scenarios, and is consistent with a 2 °C global mean warming from pre-industrial by 2100. Evaluating the outcomesmore » of both climate change scenarios in the MC2 model shows that the carbon stocks of most forests around the world increased, with the greatest gains in tropical forest regions. Temperate forest regions are projected to see strong increases in productivity offset by carbon loss to fire. The greatest cost of mitigation in terms of effects on forest carbon stocks are projected to be borne by regions in the southern hemisphere. We compare three sources of uncertainty in climate change impacts on the world’s forests: emissions scenarios, the global system climate response (i.e. climate sensitivity), and natural variability. The role of natural variability on changes in forest carbon and net primary productivity (NPP) is small, but it is substantial for impacts of wildfire. Forest productivity under the REF scenario benefits substantially from the CO 2 fertilization effect and that higher warming alone does not necessarily increase global forest carbon levels. Finally, our analysis underlines why using an ensemble of climate simulations is necessary to derive robust estimates of the benefits of greenhouse gas mitigation. It also demonstrates that constraining estimates of climate sensitivity and advancing our understanding of CO 2 fertilization effects may considerably reduce the range of projections.« less

Diagnostic Performance of CT for Diagnosis of Fat-Poor Angiomyolipoma in Patients With Renal Masses: A Systematic Review and Meta-Analysis.

PubMed

Woo, Sungmin; Suh, Chong Hyun; Cho, Jeong Yeon; Kim, Sang Youn; Kim, Seung Hyup

2017-11-01

The purpose of this article is to systematically review and perform a meta-analysis of the diagnostic performance of CT for diagnosis of fat-poor angiomyolipoma (AML) in patients with renal masses. MEDLINE and EMBASE were systematically searched up to February 2, 2017. We included diagnostic accuracy studies that used CT for diagnosis of fat-poor AML in patients with renal masses, using pathologic examination as the reference standard. Two independent reviewers assessed the methodologic quality using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity and specificity of included studies were calculated and were pooled and plotted in a hierarchic summary ROC plot. Sensitivity analyses using several clinically relevant covariates were performed to explore heterogeneity. Fifteen studies (2258 patients) were included. Pooled sensitivity and specificity were 0.67 (95% CI, 0.48-0.81) and 0.97 (95% CI, 0.89-0.99), respectively. Substantial and considerable heterogeneity was present with regard to sensitivity and specificity (I 2 = 91.21% and 78.53%, respectively). At sensitivity analyses, the specificity estimates were comparable and consistently high across all subgroups (0.93-1.00), but sensitivity estimates showed significant variation (0.14-0.82). Studies using pixel distribution analysis (n = 3) showed substantially lower sensitivity estimates (0.14; 95% CI, 0.04-0.40) compared with the remaining 12 studies (0.81; 95% CI, 0.76-0.85). CT shows moderate sensitivity and excellent specificity for diagnosis of fat-poor AML in patients with renal masses. When methods other than pixel distribution analysis are used, better sensitivity can be achieved.

A new u-statistic with superior design sensitivity in matched observational studies.

PubMed

Rosenbaum, Paul R

2011-09-01

In an observational or nonrandomized study of treatment effects, a sensitivity analysis indicates the magnitude of bias from unmeasured covariates that would need to be present to alter the conclusions of a naïve analysis that presumes adjustments for observed covariates suffice to remove all bias. The power of sensitivity analysis is the probability that it will reject a false hypothesis about treatment effects allowing for a departure from random assignment of a specified magnitude; in particular, if this specified magnitude is "no departure" then this is the same as the power of a randomization test in a randomized experiment. A new family of u-statistics is proposed that includes Wilcoxon's signed rank statistic but also includes other statistics with substantially higher power when a sensitivity analysis is performed in an observational study. Wilcoxon's statistic has high power to detect small effects in large randomized experiments-that is, it often has good Pitman efficiency-but small effects are invariably sensitive to small unobserved biases. Members of this family of u-statistics that emphasize medium to large effects can have substantially higher power in a sensitivity analysis. For example, in one situation with 250 pair differences that are Normal with expectation 1/2 and variance 1, the power of a sensitivity analysis that uses Wilcoxon's statistic is 0.08 while the power of another member of the family of u-statistics is 0.66. The topic is examined by performing a sensitivity analysis in three observational studies, using an asymptotic measure called the design sensitivity, and by simulating power in finite samples. The three examples are drawn from epidemiology, clinical medicine, and genetic toxicology. © 2010, The International Biometric Society.

Poly(ADP-ribose) Polymerase Inhibitors Sensitize Cancer Cells to Death Receptor-mediated Apoptosis by Enhancing Death Receptor Expression*

PubMed Central

Meng, X. Wei; Koh, Brian D.; Zhang, Jin-San; Flatten, Karen S.; Schneider, Paula A.; Billadeau, Daniel D.; Hess, Allan D.; Smith, B. Douglas; Karp, Judith E.; Kaufmann, Scott H.

2014-01-01

Recombinant human tumor necrosis factor-α-related apoptosis inducing ligand (TRAIL), agonistic monoclonal antibodies to TRAIL receptors, and small molecule TRAIL receptor agonists are in various stages of preclinical and early phase clinical testing as potential anticancer drugs. Accordingly, there is substantial interest in understanding factors that affect sensitivity to these agents. In the present study we observed that the poly(ADP-ribose) polymerase (PARP) inhibitors olaparib and veliparib sensitize the myeloid leukemia cell lines ML-1 and K562, the ovarian cancer line PEO1, non-small cell lung cancer line A549, and a majority of clinical AML isolates, but not normal marrow, to TRAIL. Further analysis demonstrated that PARP inhibitor treatment results in activation of the FAS and TNFRSF10B (death receptor 5 (DR5)) promoters, increased Fas and DR5 mRNA, and elevated cell surface expression of these receptors in sensitized cells. Chromatin immunoprecipitation demonstrated enhanced binding of the transcription factor Sp1 to the TNFRSF10B promoter in the presence of PARP inhibitor. Knockdown of PARP1 or PARP2 (but not PARP3 and PARP4) not only increased expression of Fas and DR5 at the mRNA and protein level, but also recapitulated the sensitizing effects of the PARP inhibition. Conversely, Sp1 knockdown diminished the PARP inhibitor effects. In view of the fact that TRAIL is part of the armamentarium of natural killer cells, these observations identify a new facet of PARP inhibitor action while simultaneously providing the mechanistic underpinnings of a novel therapeutic combination that warrants further investigation. PMID:24895135

Concurrent evaluation of visual, cytological and HPV testing as screening methods for the early detection of cervical neoplasia in Mumbai, India.

PubMed

Shastri, Surendra S; Dinshaw, Ketayun; Amin, Geetanjali; Goswami, Smriti; Patil, Sharmila; Chinoy, Roshini; Kane, S; Kelkar, Rohini; Muwonge, Richard; Mahé, Cédric; Ajit, Dulhan; Sankaranarayanan, R

2005-03-01

Naked eye visual inspection with acetic acid (VIA), magnified VIA (VIAM), visual inspection with Lugol's iodine (VILI), cytology and human papillomavirus (HPV) testing were evaluated as screening methods for the detection of high-grade squamous intraepithelial lesions (HSIL) of the uterine cervix in a cross-sectional study in Mumbai, India. Cytology, HPV testing, VIA, VIAM and VILI were carried out concurrently for 4039 women aged 30-65 years. All women were investigated with colposcopy and biopsies were taken from 939 women who had colposcopic abnormalities. The reference standard for final disease status was histology or negative colposcopy. The presence of HSIL was confirmed in 57 women (1.4%). The test characteristics for each method were calculated using standard formulae. The sensitivities of cytology, HPV testing, VIA, VIAM and VILI were 57.4%, 62.0%, 59.7%, 64.9%, and 75.4%, respectively (differences were not statistically significant). The specificities were 98.6%, 93.5%, 88.4%, 86.3%, and 84.3%, respectively. Adding a visual test to cytology or HPV testing in parallel combination resulted in a substantial increase in sensitivity, with a moderate decrease in specificity. The parallel combination of VILI and HPV testing resulted in a sensitivity of 92.0% and a specificity of 79.9%. As a single test, cytology had the best balance of sensitivity and specificity. Visual tests are promising in low-resource settings, such as India. The use of both VIA and VILI may be considered where good quality cytology or HPV testing are not feasible. The sensitivity of cytology and HPV testing increased significantly when combined with VIA or VILI.

Serum Protein Electrophoresis in the Evaluation of Lytic Bone Lesions

PubMed Central

Nystrom, Lukas M.; Buckwalter, Joseph A.; Syrbu, Sergei; Miller, Benjamin J.

2013-01-01

Serum protein electrophoresis (SPEP) is often obtained at the initial evaluation of a radiolucent bone lesion of unknown etiology. The results are considered convincing evidence of the presence or absence of a plasma cell neoplasm. The sensitivity and specificity of the SPEP have not been reported in this clinical scenario. Our purpose is to assess the diagnostic value of the SPEP in the initial work-up of the radiolucent bone lesion. We identified 182 patients undergoing evaluation of a radiolucent bone lesion that included tissue biopsy and an SPEP value. We then calculated the sen-sitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of SPEP as a diagnostic test for a plasma cell neo-plasm in this clinical scenario. Forty-six of 182 (25.3%) patients in our series were diagnosed with a plasma cell neo-plasm by histopathologic analysis. The sensitivity of SPEP was 71% and the specificity was 83%. PPV was 47% and NPV was 94%. When analyzing only those presenting with multiple lesions, the percentage of patients diag-nosed with multiple myeloma increased to 44.7% (34 of 76 patients). The SPEP, however, did not have a substantially increased diagnostic accuracy with sensitivity of 71%, specificity 79%, PPV 40% and NPV 93%. SPEP lacks sensitivity and positive predictive value to provide a definitive diagnosis of myeloma in radiolucent bone lesions, but has a high negative predictive value which may make it useful in ruling out the disease. We recommend that this test either be performed in conjunction with urine electrophoresis, immunofixation electro-phoresis and free light chain assay, or after biopsy confirming the diagnosis of myeloma. PMID:24027470

Variability in soybean yield in Brazil stemming from the interaction of heterogeneous management and climate variability

NASA Astrophysics Data System (ADS)

Cohn, A.; Bragança, A.; Jeffries, G. R.

2017-12-01

An increasing share of global agricultural production can be found in the humid tropics. Therefore, an improved understanding of the mechanisms governing variability in the output of tropical agricultural systems is of increasing importance for food security including through climate change adaptation. Yet, the long window over which many tropical crops can be sown, the diversity of crop varieties and management practices combine to challenge inference into climate risk to cropping output in analyses of tropical crop-climate sensitivity employing administrative data. In this paper, we leverage a newly developed spatially explicit dataset of soybean yields in Brazil to combat this problem. The dataset was built by training a model of remotely-sensed vegetation index data and land cover classification data using a rich in situ dataset of soybean yield and management variables collected over the period 2006 to 2016. The dataset contains soybean yields by plant date, cropping frequency, and maturity group for each 5km grid cell in Brazil. We model variation in these yields using an approach enabling the estimation of the influence of management factors on the sensitivity of soybean yields to variability in: cumulative solar radiation, extreme degree days, growing degree days, flooding rain in the harvest period, and dry spells in the rainy season. We find strong variation in climate sensitivity by management class. Planting date and maturity group each explained a great deal more variation in yield sensitivity than did cropping frequency. Brazil collects comparatively fine spatial resolution yield data. But, our attempt to replicate our results using administrative soy yield data revealed substantially lesser crop-climate sensitivity; suggesting that previous analyses employing administrative data may have underestimated climate risk to tropical soy production.

Human T-Cell Leukemia Virus I Tax Protein Sensitizes p53-Mutant Cells to DNA Damage

PubMed Central

Mihaylova, Valia T.; Green, Allison M.; Khurgel, Moshe; Semmes, Oliver J.; Kupfer, Gary M.

2018-01-01

Mutations in p53 are a common cause of resistance of cancers to standard chemotherapy and, thus, treatment failure. Reports have shown that Tax, a human T-cell leukemia virus type I encoded protein that has been associated with genomic instability and perturbation of transcription and cell cycle, sensitizes HeLa cells to UV treatment. The extent to which Tax can sensitize cells and the mechanism by which it exerts its effect are unknown. In this study, we show that Tax sensitizes p53-mutant cells to a broad range of DNA-damaging agents, including mitomycin C, a bifunctional alkylator, etoposide, a topoisomerase II drug, and UV light, but not ionizing radiation, a double-strand break agent, or vinblastine, a tubulin poison. Tax caused hypersensitivity in all p53-deleted cell lines and several, but not all, mutant-expressed p53–containing cell lines, while unexpectedly being protective in p53 wild-type (wt) cells. The effect observed in p53-deleted lines could be reversed for this by transfection of wt p53. We also show that Tax activates a p53-independent proapoptotic program through decreased expression of the retinoblastoma protein and subsequent increased E2F1 expression. The expression of several proapoptotic proteins was also induced by Tax, including Puma and Noxa, culminating in a substantial increase in Bax dimerization. Our results show that Tax can sensitize p53-mutant cells to DNA damage while protecting p53 wt cells, a side benefit that might result in reduced toxicity in normal cells. Such studies hold the promise of a novel adjunctive therapy that could make cancer chemotherapy more effective. PMID:18559532

Sensitivity of ocean acidification and oxygen to the uncertainty in climate change

NASA Astrophysics Data System (ADS)

Cao, Long; Wang, Shuangjing; Zheng, Meidi; Zhang, Han

2014-05-01

Due to increasing atmospheric CO2 concentrations and associated climate change, the global ocean is undergoing substantial physical and biogeochemical changes. Among these, changes in ocean oxygen and carbonate chemistry have great implication for marine biota. There is considerable uncertainty in the projections of future climate change, and it is unclear how the uncertainty in climate change would also affect the projection of oxygen and carbonate chemistry. To investigate this issue, we use an Earth system model of intermediate complexity to perform a set of simulations, including that which involves no radiative effect of atmospheric CO2 and those which involve CO2-induced climate change with climate sensitivity varying from 0.5 °C to 4.5 °C. Atmospheric CO2 concentration is prescribed to follow RCP 8.5 pathway and its extensions. Climate change affects carbonate chemistry and oxygen mainly through its impact on ocean temperature, ocean ventilation, and concentration of dissolved inorganic carbon and alkalinity. It is found that climate change mitigates the decrease of carbonate ions at the ocean surface but has negligible effect on surface ocean pH. Averaged over the whole ocean, climate change acts to decrease oxygen concentration but mitigates the CO2-induced reduction of carbonate ion and pH. In our simulations, by year 2500, every degree increase of climate sensitivity warms the ocean by 0.8 °C and reduces ocean-mean dissolved oxygen concentration by 5.0%. Meanwhile, every degree increase of climate sensitivity buffers CO2-induced reduction in ocean-mean carbonate ion concentration and pH by 3.4% and 0.02 units, respectively. Our study demonstrates different sensitivities of ocean temperature, carbonate chemistry, and oxygen, in terms of both the sign and magnitude to the amount of climate change, which have great implications for understanding the response of ocean biota to climate change.

VEGF induces sensory and motor peripheral plasticity, alters bladder function, and promotes visceral sensitivity

PubMed Central

2012-01-01

Background This work tests the hypothesis that bladder instillation with vascular endothelial growth factor (VEGF) modulates sensory and motor nerve plasticity, and, consequently, bladder function and visceral sensitivity. In addition to C57BL/6J, ChAT-cre mice were used for visualization of bladder cholinergic nerves. The direct effect of VEGF on the density of sensory nerves expressing the transient receptor potential vanilloid subfamily 1 (TRPV1) and cholinergic nerves (ChAT) was studied one week after one or two intravesical instillations of the growth factor. To study the effects of VEGF on bladder function, mice were intravesically instilled with VEGF and urodynamic evaluation was assessed. VEGF-induced alteration in bladder dorsal root ganglion (DRG) neurons was performed on retrogradly labeled urinary bladder afferents by patch-clamp recording of voltage gated Na+ currents. Determination of VEGF-induced changes in sensitivity to abdominal mechanostimulation was performed by application of von Frey filaments. Results In addition to an overwhelming increase in TRPV1 immunoreactivity, VEGF instillation resulted in an increase in ChAT-directed expression of a fluorescent protein in several layers of the urinary bladder. Intravesical VEGF caused a profound change in the function of the urinary bladder: acute VEGF (1 week post VEGF treatment) reduced micturition pressure and longer treatment (2 weeks post-VEGF instillation) caused a substantial reduction in inter-micturition interval. In addition, intravesical VEGF resulted in an up-regulation of voltage gated Na+ channels (VGSC) in bladder DRG neurons and enhanced abdominal sensitivity to mechanical stimulation. Conclusions For the first time, evidence is presented indicating that VEGF instillation into the mouse bladder promotes a significant increase in peripheral nerve density together with alterations in bladder function and visceral sensitivity. The VEGF pathway is being proposed as a key modulator of neural plasticity in the pelvis and enhanced VEGF content may be associated with visceral hyperalgesia, abdominal discomfort, and/or pelvic pain. PMID:23249422

Variation in hearing within a wild population of beluga whales (Delphinapterus leucas).

PubMed

Mooney, T Aran; Castellote, Manuel; Quakenbush, Lori; Hobbs, Roderick; Gaglione, Eric; Goertz, Caroline

2018-05-08

Documenting hearing abilities is vital to understanding a species' acoustic ecology and for predicting the impacts of increasing anthropogenic noise. Cetaceans use sound for essential biological functions such as foraging, navigation and communication; hearing is considered to be their primary sensory modality. Yet, we know little regarding the hearing of most, if not all, cetacean populations, which limits our understanding of their sensory ecology, population level variability and the potential impacts of increasing anthropogenic noise. We obtained audiograms (5.6-150 kHz) of 26 wild beluga whales to measure hearing thresholds during capture-release events in Bristol Bay, AK, USA, using auditory evoked potential methods. The goal was to establish the baseline population audiogram, incidences of hearing loss and general variability in wild beluga whales. In general, belugas showed sensitive hearing with low thresholds (<80 dB) from 16 to 100 kHz, and most individuals (76%) responded to at least 120 kHz. Despite belugas often showing sensitive hearing, thresholds were usually above or approached the low ambient noise levels measured in the area, suggesting that a quiet environment may be associated with hearing sensitivity and that hearing thresholds in the most sensitive animals may have been masked. Although this is just one wild population, the success of the method suggests that it should be applied to other populations and species to better assess potential differences. Bristol Bay beluga audiograms showed substantial (30-70 dB) variation among individuals; this variation increased at higher frequencies. Differences among individual belugas reflect that testing multiple individuals of a population is necessary to best describe maximum sensitivity and population variance. The results of this study quadruple the number of individual beluga whales for which audiograms have been conducted and provide the first auditory data for a population of healthy wild odontocetes. © 2018. Published by The Company of Biologists Ltd.

Comparison between esophagography and chest computed tomography for evaluation of leaks after esophagectomy and gastric pull-through.

PubMed

Lantos, Joshua E; Levine, Marc S; Rubesin, Stephen E; Lau, Charles T; Torigian, Drew A

2013-03-01

To assess the diagnostic performance of esophagography and chest computed tomography (CT) for detecting leaks after esophagectomy and gastric pull-through. Our database revealed 29 patients who had undergone esophagography and chest CT after esophagectomy. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for postoperative leaks were determined for esophagography and CT, separately and combined, on the basis of a retrospective image review. Patients were also stratified for esophagograms with water-soluble contrast alone versus water-soluble contrast and high-density barium and for CT with and without oral contrast. Our findings were retrospectively compared with those reported at initial image interpretation. Clinically relevant leaks were present in 14 (48%) of 29 patients after esophagectomy. Esophagography had a sensitivity of 79%, specificity of 73%, PPV of 73%, and NPV of 79% for detecting leaks, whereas CT had a sensitivity of 86%, specificity of 33%, PPV of 55%, and NPV of 71% and esophagography and CT combined had a sensitivity of 100%, specificity of 27%, PPV of 56%, and NPV of 100%. The sensitivity of esophagography increased with high-density barium, whereas the sensitivity of CT was the same with and without oral contrast agent. Finally, esophagography and CT were seen to have a higher sensitivity and lower specificity on retrospective review compared with the results reported at initial image interpretation. Esophagography had a slightly lower sensitivity and substantially higher specificity compared with CT for detecting leaks after esophagectomy, whereas esophagography and CT combined had a sensitivity of 100% for detecting leaks. Therefore, postoperative leaks can be excluded with confidence after esophagectomy when both tests are negative.

Test-retest reliability of infant event related potentials evoked by faces.

PubMed

Munsters, N M; van Ravenswaaij, H; van den Boomen, C; Kemner, C

2017-04-05

Reliable measures are required to draw meaningful conclusions regarding developmental changes in longitudinal studies. Little is known, however, about the test-retest reliability of face-sensitive event related potentials (ERPs), a frequently used neural measure in infants. The aim of the current study is to investigate the test-retest reliability of ERPs typically evoked by faces in 9-10 month-old infants. The infants (N=31) were presented with neutral, fearful and happy faces that contained only the lower or higher spatial frequency information. They were tested twice within two weeks. The present results show that the test-retest reliability of the face-sensitive ERP components is moderate (P400 and Nc) to substantial (N290). However, there is low test-retest reliability for the effects of the specific experimental manipulations (i.e. emotion and spatial frequency) on the face-sensitive ERPs. To conclude, in infants the face-sensitive ERP components (i.e. N290, P400 and Nc) show adequate test-retest reliability, but not the effects of emotion and spatial frequency on these ERP components. We propose that further research focuses on investigating elements that might increase the test-retest reliability, as adequate test-retest reliability is necessary to draw meaningful conclusions on individual developmental trajectories of the face-sensitive ERPs in infants. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Pharmacogenomic agreement between two cancer cell line data sets.

PubMed

2015-12-03

Large cancer cell line collections broadly capture the genomic diversity of human cancers and provide valuable insight into anti-cancer drug response. Here we show substantial agreement and biological consilience between drug sensitivity measurements and their associated genomic predictors from two publicly available large-scale pharmacogenomics resources: The Cancer Cell Line Encyclopedia and the Genomics of Drug Sensitivity in Cancer databases.

The Sensitivity of Orographic Precipitation to Flow Direction

NASA Astrophysics Data System (ADS)

Mass, C.; Picard, L.

2015-12-01

An area of substantial interest is the sensitivity of orographic precipitation to the characteristics of the incoming flow and to the surrounding environment. Some studies have suggested substantial sensitivity of precipitation within individual river drainages for relatively small directional or stability variations of incoming flow. A characterization of such flow sensitivity would be of great value for hydrometeorological prediction, the determination of Probable Maximum Precipitation statistics, and for quantifying the uncertainty in precipitation and hydrological forecasts. To gain insight into this problem, an idealized version of the Weather Research and Forecasting (WRF) modeling system was created in which simulations are driven by a single vertical sounding, with the assumption of thermal wind balance. The actual terrain is used and the full physics complement of the modeling system. The presentation will show how precipitation over the Olympic Mountains of Washington State varies as flow direction changes. This analysis will include both the aggregate precipitation over the barrier and the precipitation within individual drainages or areas. The role of surrounding terrain and the nearby coastline are also examined by removing these features from simulations. Finally, the impact of varying flow stability and speed on the precipitation over this orographic feature will be described.

Boundary formulations for sensitivity analysis without matrix derivatives

NASA Technical Reports Server (NTRS)

Kane, J. H.; Guru Prasad, K.

1993-01-01

A new hybrid approach to continuum structural shape sensitivity analysis employing boundary element analysis (BEA) is presented. The approach uses iterative reanalysis to obviate the need to factor perturbed matrices in the determination of surface displacement and traction sensitivities via a univariate perturbation/finite difference (UPFD) step. The UPFD approach makes it possible to immediately reuse existing subroutines for computation of BEA matrix coefficients in the design sensitivity analysis process. The reanalysis technique computes economical response of univariately perturbed models without factoring perturbed matrices. The approach provides substantial computational economy without the burden of a large-scale reprogramming effort.

Improving Sensitivity in Ultrasound Molecular Imaging by Tailoring Contrast Agent Size Distribution: In Vivo Studies

PubMed Central

Streeter, Jason E.; Gessner, Ryan; Miles, Iman; Dayton, Paul A.

2010-01-01

Molecular imaging with ultrasound relies on microbubble contrast agents (MCAs) selectively adhering to a ligand-specific target. Prior studies have shown that only small quantities of microbubbles are retained at their target sites, therefore, enhancing contrast sensitivity to low concentrations of microbubbles is essential to improve molecular imaging techniques. In order to assess the effect of MCA diameter on imaging sensitivity, perfusion and molecular imaging studies were performed with microbubbles of varying size distributions. To assess signal improvement and MCA circulation time as a function of size and concentration, blood perfusion was imaged in rat kidneys using nontargeted size-sorted MCAs with a Siemens Sequoia ultrasound system (Siemans, Mountain View, CA) in cadence pulse sequencing (CPS) mode. Molecular imaging sensitivity improvements were studied with size-sorted αvβ3-targeted bubbles in both fibrosarcoma and R3230 rat tumor models. In perfusion imaging studies, video intensity and contrast persistence was ≈8 times and ≈3 times greater respectively, for “sorted 3-micron” MCAs (diameter, 3.3 ± 1.95 μm) when compared to “unsorted” MCAs (diameter, 0.9 ± 0.45 μm) at low concentrations. In targeted experiments, application of sorted 3-micron MCAs resulted in a ≈20 times video intensity increase over unsorted populations. Tailoring size-distributions results in substantial imaging sensitivity improvement over unsorted populations, which is essential in maximizing sensitivity to small numbers of MCAs for molecular imaging. PMID:20236606

Baroreflex buffering and susceptibility to vasoactive drugs

NASA Technical Reports Server (NTRS)

Jordan, Jens; Tank, Jens; Shannon, John R.; Diedrich, Andre; Lipp, Axel; Schroder, Christoph; Arnold, Guy; Sharma, Arya M.; Biaggioni, Italo; Robertson, David;

African bees to control African elephants

NASA Astrophysics Data System (ADS)

Vollrath, Fritz; Douglas-Hamilton, Iain

2002-11-01

Numbers of elephants have declined in Africa and Asia over the past 30 years while numbers of humans have increased, both substantially. Friction between these two keystone species is reaching levels which are worryingly high from an ecological as well as a political viewpoint. Ways and means must be found to keep the two apart, at least in areas sensitive to each species' survival. The aggressive African bee might be one such method. Here we demonstrate that African bees deter elephants from damaging the vegetation and trees which house their hives. We argue that bees can be employed profitably to protect not only selected trees, but also selected areas, from elephant damage.

Optical guidance vidicon test program

NASA Technical Reports Server (NTRS)

Eiseman, A. R.; Stanton, R. H.; Voge, C. C.

1976-01-01

A laboratory and field test program was conducted to quantify the optical navigation parameters of the Mariner vidicons. A scene simulator and a camera were designed and built for vidicon tests under a wide variety of conditions. Laboratory tests characterized error sources important to the optical navigation process and field tests verified star sensitivity and characterized comet optical guidance parameters. The equipment, tests and data reduction techniques used are described. Key test results are listed. A substantial increase in the understanding of the use of selenium vidicons as detectors for spacecraft optical guidance was achieved, indicating a reduction in residual offset errors by a factor of two to four to the single pixel level.

African bees to control African elephants.

PubMed

Vollrath, Fritz; Douglas-Hamilton, Iain

2002-11-01

Numbers of elephants have declined in Africa and Asia over the past 30 years while numbers of humans have increased, both substantially. Friction between these two keystone species is reaching levels which are worryingly high from an ecological as well as a political viewpoint. Ways and means must be found to keep the two apart, at least in areas sensitive to each species' survival. The aggressive African bee might be one such method. Here we demonstrate that African bees deter elephants from damaging the vegetation and trees which house their hives. We argue that bees can be employed profitably to protect not only selected trees, but also selected areas, from elephant damage.

Acoustic Guided Wave Testing of Pipes of Small Diameters

NASA Astrophysics Data System (ADS)

Muravev, V. V.; Muraveva, O. V.; Strizhak, V. A.; Myshkin, Y. V.

2017-10-01

Acoustic path is analyzed and main parameters of guided wave testing are substanti- ated applied to pipes of small diameters. The method is implemented using longitudinal L(0,1) and torsional T(0,1) waves based on electromagnetic-acoustic (EMA) transducers. The method of multiple reflections (MMR) combines echo-through, amplitude-shadow and time-shadow methods. Due to the effect of coherent amplification of echo-pulses from defects the sensitivity to the defects of small sizes at the signal analysis on the far reflections is increased. An oppor- tunity of detection of both local defects (dents, corrosion damages, rolling features, pitting, cracks) and defects extended along the pipe is shown.

Pre-oxidation for Colorimetric Sensor Array Detection of VOCs

PubMed Central

Lin, Hengwei; Jang, Minseok; Suslick, Kenneth S.

2011-01-01

A disposable pre-oxidation technique is reported that dramatically improves the detection and identification of volatile organic compounds (VOCs) by a colorimetric sensor array. By passing a vapor stream through a tube packed with chromic acid on silica immediately before the colorimetric sensor array, the sensitivity to less reactive VOCs is substantially increased and limits of detection (LODs) are improved ~300-fold, permitting the detection, identification, and discrimination of 20 commonly found indoor VOC pollutants at both their immediately dangerous to life or health (IDLH) and at permissible exposure limits (PEL) concentrations. LODs of these pollutants were on average 1.4% of their respective PELs. PMID:21967478

Positron Emission Tomography Molecular Imaging in Late-Life Depression

PubMed Central

Hirao, Kentaro; Smith, Gwenn S.

2017-01-01

Molecular imaging represents a bridge between basic and clinical neuroscience observations and provides many opportunities for translation and identifying mechanisms that may inform prevention and intervention strategies in late-life depression (LLD). Substantial advances in instrumentation and radiotracer chemistry have resulted in improved sensitivity and spatial resolution and the ability to study in vivo an increasing number of neurotransmitters, neuromodulators, and, importantly, neuropathological processes. Molecular brain imaging studies in LLD will be reviewed, with a primary focus on positron emission tomography. Future directions for the field of molecular imaging in LLD will be discussed, including integrating molecular imaging with genetic, neuropsychiatric, and cognitive outcomes and multimodality neuroimaging. PMID:24394152

Brane inflation and cosmic string tension in superstring theory

NASA Astrophysics Data System (ADS)

Firouzjahi, Hassan; Tye, S.-H. Henry

2005-03-01

In a simple reanalysis of the KKLMMT scenario, we argue that the slow roll condition in the D3-overline {D}3 -brane inflationary scenario in superstring theory requires no more than a moderate tuning. The cosmic string tension is very sensitive to the conformal coupling: with less fine-tuning, the cosmic string tension (as well as the ratio of tensor to scalar perturbation mode) increases rapidly and can easily saturate the present observational bound. In a multi-throat brane inflationary scenario, this feature substantially improves the chance of detecting and measuring the properties of the cosmic strings as a window to the superstring theory and our pre-inflationary universe.

Meta-analysis of diagnostic test data: a bivariate Bayesian modeling approach.

PubMed

Verde, Pablo E

2010-12-30

In the last decades, the amount of published results on clinical diagnostic tests has expanded very rapidly. The counterpart to this development has been the formal evaluation and synthesis of diagnostic results. However, published results present substantial heterogeneity and they can be regarded as so far removed from the classical domain of meta-analysis, that they can provide a rather severe test of classical statistical methods. Recently, bivariate random effects meta-analytic methods, which model the pairs of sensitivities and specificities, have been presented from the classical point of view. In this work a bivariate Bayesian modeling approach is presented. This approach substantially extends the scope of classical bivariate methods by allowing the structural distribution of the random effects to depend on multiple sources of variability. Meta-analysis is summarized by the predictive posterior distributions for sensitivity and specificity. This new approach allows, also, to perform substantial model checking, model diagnostic and model selection. Statistical computations are implemented in the public domain statistical software (WinBUGS and R) and illustrated with real data examples. Copyright © 2010 John Wiley & Sons, Ltd.

Low-background performance of a monolithic InSb CCD array

NASA Technical Reports Server (NTRS)

Bregman, J. D.; Goebel, J. H.; Mccreight, C. R.; Matsumoto, T.

1982-01-01

A 20 element monolithic InSb charge coupled device (CCD) detector array was measured under low background conditions to assess its potential for orbital astronomical applications. At a temperature of 64 K, previous results for charge transfer efficiency (CTE) were reproduced, and a sensitivity of about 2 x 10 to the minus 15th power joules was measured. At 27 and 6 K, extended integration times were achieved, but CTE was substantially degraded. The noise was approximately 6000 charges, which was in excess of the level where statistical fluctuations from the illumination could be detected. A telescope demonstration was performed showing that the array sensitivity and difficulty of operation were not substantially different from laboratory levels. Ways in which the device could be improved for astronomical applications were discussed.

Electronic characterization of lithographically patterned microcoils for high sensitivity NMR detection.

PubMed

Demas, Vasiliki; Bernhardt, Anthony; Malba, Vince; Adams, Kristl L; Evans, Lee; Harvey, Christopher; Maxwell, Robert S; Herberg, Julie L

2009-09-01

Nuclear magnetic resonance (NMR) offers a non-destructive, powerful, structure-specific analytical method for the identification of chemical and biological systems. The use of radio frequency (RF) microcoils has been shown to increase the sensitivity in mass-limited samples. Recent advances in micro-receiver technology have further demonstrated a substantial increase in mass sensitivity [D.L. Olson, T.L. Peck, A.G. Webb, R.L. Magin, J.V. Sweedler, High-resolution microcoil H-1-NMR for mass-limited, nanoliter-volume samples, Science 270 (5244) (1995) 1967-1970]. Lithographic methods for producing solenoid microcoils possess a level of flexibility and reproducibility that exceeds previous production methods, such as hand winding microcoils. This paper presents electrical characterizations of RF microcoils produced by a unique laser lithography system that can pattern three dimensional surfaces and compares calculated and experimental results to those for wire wound RF microcoils. We show that existing optimization conditions for RF coil design still hold true for RF microcoils produced by lithography. Current lithographic microcoils show somewhat inferior performance to wire wound RF microcoils due to limitations in the existing electroplating technique. In principle, however, when the pitch of the RF microcoil is less than 100mum lithographic coils should show comparable performance to wire wound coils. In the cases of larger pitch, wire cross sections can be significantly larger and resistances lower than microfabricated conductors.

Role of litter decomposition sensitivity to water content in non-additive litter mixture effect: theoretical demonstration and validation with a peatland litter experiment

NASA Astrophysics Data System (ADS)

Gogo, Sébastien; Leroy, Fabien; Zoccatelli, Renata; Bernard-Jannin, Léonard; Laggoun-Défarge, Fatima

2017-04-01

In this work, we showed theoretically that differences in litter water content, evaporation rate and reaction rate sensitivity to water content can give account of non-additive litter mixture effect. More specifically two litters with the same dependence to litter water content and contrasted water content, and 2 litters with contrasted decomposition sensitivity to litter water content can exert synergistic mixture effect on decomposition when the 2 litters interact. In these situations, water can flow from the wettest to the driest litter, changing the whole reaction rate without changing the whole litter water content. The reaction rate increase of the litter receiving the water was relatively more important than the reaction rate decrease of the litter supplying the water. These theoretical considerations were validated with experimental data. Sphagnum rubellum and Molinia caerulea decompose faster in measured mixture than expected from the rates obtained in monoculture incubation. Sphagnum rubellum litter can contain more water, which evaporates at a slower rate than Molinia caerulea. It is thus proposed that water flowed from Sphagnum rubellum litter to the Molinia caerulea litter, with a substantial increase of the decomposition of the latter. The physical and biochemical litter characteristics towards water explains a fraction of the synergistic effect of mixing the 2 litters, which suggests that other factors intervene in this effect, such as the carbon substrate.

Changes in Temperature Sensitivity and Activation Energy of Soil Organic Matter Decomposition in Different Qinghai-Tibet Plateau Grasslands.

PubMed

Li, Jie; He, Nianpeng; Wei, Xuehong; Gao, Yang; Zuo, Yao

2015-01-01

Qinghai-Tibet Plateau grasslands are unique geographical regions and store substantial soil organic matter (SOM) in the soil surface, which make them very sensitive to global climate change. Here, we focused on three main grassland types (alpine meadow, steppe, and desert) and conducted a soil incubation experiment at five different temperatures (5, 10, 15, 20, and 25°C) to investigate SOM decomposition rates (R), temperature sensitivity (Q10), and activation energy (Ea). The results showed that grassland type and incubation temperature had significant impact on R (P < 0.001), and the values of R were exponential correlated with incubation temperature in three alpine grasslands. At the same temperature, R was in the following order: alpine meadow > alpinesteppe > alpine desert. The Q10 values differed significantly among different grasslands, and the overall trends were as follows: alpine meadow (1.56 ± 0.09) < alpine steppe (1.88 ± 0.23) < alpine desert (2.39 ± 0.32). Moreover, the Ea values differed significantly across different grassland types (P < 0.001) and increased with increasing incubation time. The exponential negative correlations between Ea and R at 20°C across all grassland types (all Ps < 0.001) indicated that the substrate-quality temperature hypothesis is applicable to the alpine grasslands. Our findings provide new insights for understanding the responses of SOM decomposition and storage to warming scenarios in this Plateau.

Interacting effects of climate change and habitat fragmentation on drought-sensitive butterflies

NASA Astrophysics Data System (ADS)

Oliver, Tom H.; Marshall, Harry H.; Morecroft, Mike D.; Brereton, Tom; Prudhomme, Christel; Huntingford, Chris

2015-10-01

Climate change is expected to increase the frequency of some climatic extremes. These may have drastic impacts on biodiversity, particularly if meteorological thresholds are crossed, leading to population collapses. Should this occur repeatedly, populations may be unable to recover, resulting in local extinctions. Comprehensive time series data on butterflies in Great Britain provide a rare opportunity to quantify population responses to both past severe drought and the interaction with habitat area and fragmentation. Here, we combine this knowledge with future projections from multiple climate models, for different Representative Concentration Pathways (RCPs), and for simultaneous modelled responses to different landscape characteristics. Under RCP8.5, which is associated with `business as usual’ emissions, widespread drought-sensitive butterfly population extinctions could occur as early as 2050. However, by managing landscapes and particularly reducing habitat fragmentation, the probability of persistence until mid-century improves from around zero to between 6 and 42% (95% confidence interval). Achieving persistence with a greater than 50% chance and right through to 2100 is possible only under both low climate change (RCP2.6) and semi-natural habitat restoration. Our data show that, for these drought-sensitive butterflies, persistence is achieved more effectively by restoring semi-natural landscapes to reduce fragmentation, rather than simply focusing on increasing habitat area, but this will only be successful in combination with substantial emission reductions.

Sea-Level Rise and Land Subsidence in Deltas: Estimating Future Flood Risk Through Integrated Natural and Human System Modeling

NASA Astrophysics Data System (ADS)

Tessler, Z. D.; Vorosmarty, C. J.

2016-12-01

Deltas are highly sensitive to local human activities, land subsidence, regional water management, global sea-level rise, and climate extremes. We present a new delta flood exposure and risk framework for estimating the sensitivity of deltas to relative sea-level rise. We have applied this framework to a set of global environmental, geophysical, and social indicators over 48 major river deltas to quantify how contemporary risks vary across delta systems. The risk modeling framework incorporates upstream sediment flux and coastal land subsidence models, global empirical estimates of contemporary storm surge exposure, and population distribution and growth. Future scenarios are used to test the impacts on coastal flood risk of upstream dam construction, coastal population growth, accelerated sea-level rise, and enhanced storm surge. Results suggest a wide range of outcomes across different delta systems within each scenario. Deltas in highly engineered watersheds (Mississippi, Rhine) exhibit less sensitivity to increased dams due to saturation of sediment retention effects, though planned or under-construction dams are expected to have a substantial impact in the Yangtze, Irrawaddy, and Magdalena deltas. Population growth and sea-level rise are expected to be the dominant drivers of increased human risk in most deltas, with important exceptions in several countries, particularly China, where population are forecast to contract over the next several decades.

Experimental evidence of human recreational disturbance effects on bird-territory establishment.

PubMed

Bötsch, Yves; Tablado, Zulima; Jenni, Lukas

2017-07-12

The worldwide increase in human outdoor activities raises concerns for wildlife. Human disturbances, even at low levels, are likely to impact species during sensitive periods of the annual cycle. However, experimental studies during the putative sensitive period of territory establishment of birds which not only investigate low disturbance levels, but which also exclude the effect of habitat modification (e.g. walking trails) are lacking. Here, we experimentally disturbed birds in forest plots by walking through twice a day during territory establishment. Later we compared the breeding bird community of experimentally disturbed plots with that of undisturbed control plots. We discovered that the number of territories (-15.0%) and species richness (-15.2%) in disturbed plots were substantially reduced compared with control plots. Species most affected included those sensitive to human presence (assessed by flight-initiation distances), open-cup nesters and above-ground foragers. Long-distance migrants, however, were unaffected due to their arrival after experimental disturbance took place. These findings highlight how territory establishment is a sensitive period for birds, when even low levels of human recreation may be perceived as threatening, and alter settlement decisions. This can have important implications for the conservation of species, which might go unnoticed when focusing only on already established birds. © 2017 The Author(s).

Are current case-finding methods under-diagnosing tuberculosis among women in Myanmar? An analysis of operational data from Yangon and the nationwide prevalence survey.

PubMed

Khan, M S; Khine, T M; Hutchison, C; Coker, R J; Hane, K M; Innes, A L; Aung, S

2016-03-03

Although there is a large increase in investment for tuberculosis control in Myanmar, there are few operational analyses to inform policies. Only 34% of nationally reported cases are from women. In this study, we investigate sex differences in tuberculosis diagnoses in Myanmar in order to identify potential health systems barriers that may be driving lower tuberculosis case finding among women. From October 2014 to March 2015, we systematically collected data on all new adult smear positive tuberculosis cases in ten township health centres across Yangon, the largest city in Myanmar, to produce an electronic tuberculosis database. We conducted a descriptive cross-sectional analysis of sex differences in tuberculosis diagnoses at the township health centres. We also analysed national prevalence survey data to calculate additional case finding in men and women by using sputum culture when smear microscopy was negative, and estimated the sex-specific impact of using a more sensitive diagnostic tool at township health centres. Overall, only 514 (30%) out of 1371 new smear positive tuberculosis patients diagnosed at the township health centres were female. The proportion of female patients varied by township (from 21% to 37%, p = 0.0172), month of diagnosis (37% in February 2015 and 23% in March 2015 p = 0.0004) and age group (26% in 25-64 years and 49% in 18-25 years, p < 0.0001). Smear microscopy grading of sputum specimens was not substantially different between sexes. The prevalence survey analysis indicated that the use of a more sensitive diagnostic tool could result in the proportion of females diagnosed at township health centres increasing to 36% from 30%. Our study, which is the first to systematically compile and analyse routine operational data from tuberculosis diagnostic centres in Myanmar, found that substantially fewer women than men were diagnosed in all study townships. The sex ratio of newly diagnosed cases varied by age group, month of diagnosis and township of diagnosis. Low sensitivity of tuberculosis diagnosis may lead to a potential under-diagnosis of tuberculosis among women.

Psychological factors associated with self-reported sensitivity to mobile phones.

PubMed

Rubin, G James; Cleare, Anthony J; Wessely, Simon

2008-01-01

Some people report symptoms associated with mobile phone use. A minority also report "electrosensitivity," experiencing symptoms following exposure to other electrical devices. Research suggests that electromagnetic fields do not trigger these symptoms. In this study, we examined the differences between these two "sensitive" groups and healthy controls. Fifty-two people who reported sensitivity to mobile phones, 19 people who reported sensitivity to mobile phones and "electrosensitivity," and 60 nonsensitive controls completed a questionnaire assessing the following: primary reason for using a mobile phone, psychological health, symptoms of depression, modern health worries (MHW), general health status, symptom severity, and the presence of other medically unexplained syndromes. Perceived sensitivity was associated with an increased likelihood of using a mobile phone predominantly for work (3% of controls, 13% of those sensitive to mobile phones, and 21% of those reporting "electrosensitivity") and greater MHW concerning radiation [mean (S.D.) on a scale of 1-5: 2.0 (1.0), 2.7 (0.9), and 4.0 (0.8), respectively]. Participants who reported "electrosensitivity" also experienced greater depression, greater worries about tainted food and toxic interventions, worse general health on almost every measure, and a greater number of other medically unexplained syndromes compared to participants from the other two groups. No group differences were observed with regards to psychiatric cases. The data illustrate that patients reporting "electrosensitivity" experience substantially worse health than either healthy individuals or people who report sensitivity to mobile phones but who do not adopt the label "electrosensitivity." Clinicians and researchers would be wise to pay greater attention to this subdivision.

Increasing horizontal resolution in numerical weather prediction and climate simulations: illusion or panacea?

PubMed

Wedi, Nils P

2014-06-28

The steady path of doubling the global horizontal resolution approximately every 8 years in numerical weather prediction (NWP) at the European Centre for Medium Range Weather Forecasts may be substantially altered with emerging novel computing architectures. It coincides with the need to appropriately address and determine forecast uncertainty with increasing resolution, in particular, when convective-scale motions start to be resolved. Blunt increases in the model resolution will quickly become unaffordable and may not lead to improved NWP forecasts. Consequently, there is a need to accordingly adjust proven numerical techniques. An informed decision on the modelling strategy for harnessing exascale, massively parallel computing power thus also requires a deeper understanding of the sensitivity to uncertainty--for each part of the model--and ultimately a deeper understanding of multi-scale interactions in the atmosphere and their numerical realization in ultra-high-resolution NWP and climate simulations. This paper explores opportunities for substantial increases in the forecast efficiency by judicious adjustment of the formal accuracy or relative resolution in the spectral and physical space. One path is to reduce the formal accuracy by which the spectral transforms are computed. The other pathway explores the importance of the ratio used for the horizontal resolution in gridpoint space versus wavenumbers in spectral space. This is relevant for both high-resolution simulations as well as ensemble-based uncertainty estimation. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Prediction of seasonal climate-induced variations in global food production

NASA Astrophysics Data System (ADS)

Iizumi, Toshichika; Sakuma, Hirofumi; Yokozawa, Masayuki; Luo, Jing-Jia; Challinor, Andrew J.; Brown, Molly E.; Sakurai, Gen; Yamagata, Toshio

2013-10-01

Consumers, including the poor in many countries, are increasingly dependent on food imports and are thus exposed to variations in yields, production and export prices in the major food-producing regions of the world. National governments and commercial entities are therefore paying increased attention to the cropping forecasts of important food-exporting countries as well as to their own domestic food production. Given the increased volatility of food markets and the rising incidence of climatic extremes affecting food production, food price spikes may increase in prevalence in future years. Here we present a global assessment of the reliability of crop failure hindcasts for major crops at two lead times derived by linking ensemble seasonal climatic forecasts with statistical crop models. We found that moderate-to-marked yield loss over a substantial percentage (26-33%) of the harvested area of these crops is reliably predictable if climatic forecasts are near perfect. However, only rice and wheat production are reliably predictable at three months before the harvest using within-season hindcasts. The reliabilities of estimates varied substantially by crop--rice and wheat yields were the most predictable, followed by soybean and maize. The reasons for variation in the reliability of the estimates included the differences in crop sensitivity to the climate and the technology used by the crop-producing regions. Our findings reveal that the use of seasonal climatic forecasts to predict crop failures will be useful for monitoring global food production and will encourage the adaptation of food systems toclimatic extremes.

Age-related inflammation and insulin resistance: a review of their intricate interdependency.

PubMed

Park, Min Hi; Kim, Dae Hyun; Lee, Eun Kyeong; Kim, Nam Deuk; Im, Dong Soon; Lee, Jaewon; Yu, Byung Pal; Chung, Hae Young

2014-12-01

Chronic inflammation is a major risk factor underlying aging and the associated diseases of aging; of particular interest is insulin resistance during aging. Chronic inflammation impairs normal lipid accumulation, adipose tissue function, mitochondrial function, and causes endoplasmic reticulum (ER) stress, which lead to insulin resistance. However, some studies show that insulin resistance itself amplifies chronic inflammation. The activity of the insulin-dependent Akt signaling pathway is highlighted because of its decrease in insulin-sensitive organs, like liver and muscle, which may underlie insulin resistance and hyperinsulinemia, and its increased levels in non-metabolic organs, such as kidney and aorta. In that the prevalence of obesity has increased substantially for all age groups in recent years, our review summarizes the data showing the involvement of chronic inflammation in obesity-induced insulin resistance, which perpetuates reciprocal interactions between the chronic inflammatory process and increased adiposity, thereby accelerating the aging process.

Cell-Intrinsic Determinants of Ibrutinib-Induced Apoptosis in Chronic Lymphocytic Leukemia.

PubMed

Amin, Nisar A; Balasubramanian, Sriram; Saiya-Cork, Kamlai; Shedden, Kerby; Hu, Nan; Malek, Sami N

2017-02-15

Purpose: Ibrutinib, a Bruton tyrosine kinase (BTK) inhibitor, is approved for the treatment of relapsed chronic lymphocytic leukemia (CLL) and CLL with del17p. Mechanistically, ibrutinib interferes with B-cell receptor (BCR) signaling as well as multiple CLL cell-to-microenvironment interactions. Given the importance of ibrutinib in the management of CLL, a deeper understanding of factors governing sensitivity and resistance is warranted. Experimental Design: We studied 48 longitudinally sampled paired CLL samples, 42 of which were procured before and after standard CLL chemotherapies, and characterized them for well-studied CLL molecular traits as well as by whole-exome sequencing and SNP 6.0 array profiling. We exposed these samples to 0.25 to 5 μmol/L of ibrutinib ex vivo and measured apoptosis fractions as well as BCR signaling by immunoblotting. We disrupted TP53 in HG3, PGA1, and PG-EBV cell lines and measured BCR signaling and ibrutinib responses. Results: CLL samples demonstrated a surprisingly wide range of ex vivo sensitivities to ibrutinib, with IC 50 values ranging from 0.4 to 9.7 μmol/L. Unmutated IGVH status, elevated ZAP70 expression, and trisomy 12 were associated with heightened sensitivity to ibrutinib treatment. Five CLL samples were substantially more resistant to ibrutinib following relapse from chemotherapy; of these, three had acquired a del17p/ TP53 -mutated status. A validation sample of 15 CLL carrying TP53 mutations, of which 13 carried both del17p and a TP53 mutation, confirmed substantially less sensitivity to ibrutinib-induced apoptosis. Conclusions: This study identifies that CLL harboring del17p/ TP53 -mutated cells are substantially less sensitive to ibrutinib-induced apoptosis than del17p/ TP53 wild-type cells. Clin Cancer Res; 23(4); 1049-59. ©2016 AACR . ©2016 American Association for Cancer Research.

Relevance of sensitization to occupational allergy and asthma in the detergent industry.

PubMed

Basketter, David; Berg, Ninna; Kruszewski, Francis H; Sarlo, Katherine; Concoby, Beth

2012-01-01

There exists considerable historic experience of the relationship between exposure and both the induction of sensitization and the elicitation of respiratory symptoms from industrial enzymes of bacterial and fungal origin used in a wide variety of detergent products. The detergent industry in particular has substantial experience of how the control of exposure leads to limitation of sensitization with low risk of symptoms. However, the experience also shows that there are substantial gaps in knowledge, even when the potential occupational allergy problem is firmly under control, and also that the relationship between exposure and sensitization can be hard to establish. The latter aspect includes a poor appreciation of how peak exposures and low levels of exposure over time contribute to sensitization. Furthermore, while a minority of workers develop specific IgE, essentially none appear to have symptoms, a situation which appears to contradict the allergy dogma that, once sensitized, an individual will react to much lower levels of exposure. For enzymes, the expression of symptoms occurs at similar or higher levels than those that cause induction. In spite of some knowledge gaps, medical surveillance programs and constant air monitoring provide the tools for successful management of enzymes in the occupational setting. Ultimately, the knowledge gained from the occupational setting facilitates the completion of safety assessments for consumer exposure to detergent enzymes. Such assessments have been proven to be correct by the decades of safe use both occupationally and in consumer products.

Competing influences of greenhouse warming and aerosols on Asian summer monsoon circulation and rainfall

NASA Astrophysics Data System (ADS)

Lau, William Ka-Ming; Kim, Kyu-Myong

2017-05-01

In this paper, we have compared and contrasted competing influences of greenhouse gases (GHG) warming and aerosol forcing on Asian summer monsoon circulation and rainfall based on CMIP5 historical simulations. Under GHG-only forcing, the land warms much faster than the ocean, magnifying the pre-industrial climatological land-ocean thermal contrast and hemispheric asymmetry, i.e., warmer northern than southern hemisphere. A steady increasing warm-ocean-warmer-land (WOWL) trend has been in effect since the 1950's substantially increasing moisture transport from adjacent oceans, and enhancing rainfall over the Asian monsoon regions. However, under GHG warming, increased atmospheric stability due to strong reduction in mid-tropospheric and near surface relative humidity coupled to an expanding subsidence areas, associated with the Deep Tropical Squeeze (DTS, Lau and Kim, 2015b) strongly suppress monsoon convection and rainfall over subtropical and extratropical land, leading to a weakening of the Asian monsoon meridional circulation. Increased anthropogenic aerosol emission strongly masks WOWL, by over 60% over the northern hemisphere, negating to a large extent the rainfall increase due to GHG warming, and leading to a further weakening of the monsoon circulation, through increasing atmospheric stability, most likely associated with aerosol solar dimming and semi-direct effects. Overall, we find that GHG exerts stronger positive rainfall sensitivity, but less negative circulation sensitivity in SASM compared to EASM. In contrast, aerosols exert stronger negative impacts on rainfall, but less negative impacts on circulation in EASM compared to SASM.

Sensitivity to Madden-Julian Oscillation variations on heavy precipitation over the contiguous United States

NASA Astrophysics Data System (ADS)

Jones, Charles; Carvalho, Leila M. V.

2014-10-01

The Madden-Julian Oscillation (MJO) is the most prominent mode of tropical intraseasonal variability in the climate system and has worldwide influences on the occurrences and forecasts of heavy precipitation. This paper investigates the sensitivity of precipitation over the contiguous United States (CONUS) in a case study (boreal 2004-05 winter). Several major storms affected the western and eastern CONUS producing substantial economic and social impacts including loss of lives. The Weather Research and Forecasting (WRF) model is used to perform experiments to test the significance of the MJO amplitude. The control simulation uses the MJO amplitude observed by reanalysis, whereas the amplitude is modified in perturbation experiments. WRF realistically simulates the precipitation variability over the CONUS, although large biases occur over the Western and Midwest United States. Daily precipitation is aggregated in western, central and eastern sectors and the frequency distribution is analyzed. Increases in MJO amplitude produce moderate increases in the median and interquartile range and large and robust increases in extreme (90th and 95th percentiles) precipitation. The MJO amplitude clearly affects the transport of moisture from the tropical Pacific and Gulf of Mexico into North America providing moist rich air masses and the dynamical forcing that contributes to heavy precipitation.

Relationships between the intensity and duration of Peltier heat stimulation and pain magnitude

PubMed Central

Vierck, Charles J.; Mauderli, Andre P.; Riley, Joseph L.

2013-01-01

Ramp-and-hold heat stimulation with a Peltier thermode is a standard procedure for quantitative sensory testing of human pain sensitivity. Because myelinated and unmyelinated nociceptive afferents respond preferentially to changing and steady temperatures, respectively, ramp-and-hold heat stimulation could assess processing of input from A-delta nociceptors early and C nociceptors late during prolonged thermal stimulation. In order to evaluate the progression from dynamic change to a steady temperature during prolonged Peltier stimulation, recordings of temperatures at the probe-skin interface were obtained. First, recordings of temperature during contact-and-hold stimulation (solenoid powered delivery of a preheated thermode to the skin) provided an evaluation of heat dissipation from the beginning of stimulation, uncontaminated by ramping. The heat sink effect lasted up to 8 sec. and accounted in part for substantial increases in pain intensity as a combined function of durations from 1–16 sec. and stimulus intensities from 43°C to 59°. Recordings during longer periods of stimulation showed that Peltier stimulation generated feedback oscillations in temperature for up to 75 sec that were tracked by subjects’ continuous ratings of pain. During 120 sec. trials, sensitization of pain was observed over 45 seconds after the oscillations subsided. In contrast, sensitization was not observed during 130.5 sec. of stimulation with alternately increasing and decreasing temperatures that maintained a target eVAS rating of 35. Thus, long duration stimulation can be utilized to evaluate sensitization, presumably of C nociception, when not disrupted by oscillations inherent to feedback control of Peltier stimulation. PMID:23423165

77 FR 15757 - Agency Information Collection Activities; Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-16

... require sellers of consumer commodities to keep records that substantiate ``cents off,'' ``introductory... competitively sensitive information such as costs, sales statistics, inventories, formulas, patterns devices...

Poole-frenkel piezoconductive element and sensor

DOEpatents

Habermehl, Scott D.

2004-08-03

A new class of highly sensitive piezoconductive strain sensor elements and sensors has been invented. The new elements function under conditions such that electrical conductivity is dominated by Poole-Frenkel transport. A substantial piezoconductive effect appears in this regime, allowing the new sensors to exhibit sensitivity to applied strain as much as two orders of magnitude in excess of prior art sensors based on doped silicon.

Accuracy of the ECG for differential diagnosis between hypertrophic cardiomyopathy and athlete's heart: comparison between the European Society of Cardiology (2010) and International (2017) criteria.

PubMed

Zorzi, Alessandro; Calore, Chiara; Vio, Riccardo; Pelliccia, Antonio; Corrado, Domenico

2018-05-01

Interpretation of the athlete's ECG is based on differentiation between benign ECG changes and potentially pathological abnormalities. The aim of the study was to compare the 2010 European Society of Cardiology (ESC) and the 2017 International criteria for differential diagnosis between hypertrophic cardiomyopathy (HCM) and athlete's heart. The study populations included 200 patients with HCM and 563 athletes grouped as follows: 'group 1', including normal ECG and isolated increase of QRS voltages, which are considered non-pathologic according to ESC and International criteria; 'group 2', including left atrial enlargement or left axis deviation in isolation and Q-waves with an amplitude ≥4 mm but <25% of the ensuing R-wave and a duration <0.04 s which are considered pathologic according to the ESC but not according to the International criteria; and 'group 3', including abnormalities which are considered pathologic according to ESC and International criteria. Overall, the 2010 ESC criteria showed a sensitivity of 95.5% and a specificity of 86.9%. Considering group 2 ECG changes as normal according to the International criteria led to a statistically significant (p<0.001) increase of specificity to 95.9%, associated with a non-significant (p=0.47) reduction of sensitivity to 93%. Among patients with HCM, there was a significant increase of maximal left ventricular wall thickness from group 1 to 3 (p=0.02). The use of 2017 International criteria is associated with a substantial increase in specificity and a marginal decrease in sensitivity for differential diagnosis between HCM and athlete's heart. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Acute sensitivity of three Cladoceran species to different types of microplastics in combination with thermal stress.

PubMed

Jaikumar, Gayathri; Baas, Jan; Brun, Nadja R; Vijver, Martina G; Bosker, Thijs

2018-08-01

Microplastics (<5 mm, MP) are ubiquitously distributed in the environment, causing increasing concern regarding their potential toxicity to organisms. To date, most research has focussed on the impacts of MPs on marine and estuarine organisms, with fewer studies focussing on the effects of microplastics on freshwater ecosystems, especially under different environmental conditions. In the present study, the sensitivity of two temperate Cladoceran species, Daphnia magna and Daphnia pulex, and a smaller tropical species Ceriodaphnia dubia, to primary microplastics (PMP) and secondary (weathered) microplastics (SMP) was assessed. A prolonged acute toxicity assay (up to 72 or 96 h) was performed at 18°, 22°, and 26 °C, to determine the influence of temperature as an additional stressor and survival data were analysed using toxicokinetic-toxicodynamic (TK-TD) model. Acute sensitivity of D. magna and D. pulex to both PMP and SMP increased sharply with temperature, whereas that of C. dubia remained relatively stable across temperatures. C. dubia was the most sensitive species at 18 °C, followed by D. pulex and D. magna, which were of comparable sensitivity. However, this ranking was reversed at 26 °C as could be seen from the No Effect Concentration (NEC) estimates of the TK-TD model. In addition, SMP and PMP had a similar effect on D. magna and D. pulex, but PMP was more toxic to C. dubia. Effects on survival were strongly time-dependent and became substantially more severe after the standard 48 h test period. Our results indicate that sensitivity to microplastics may differ between species for different types of microplastics, and could be drastically influenced by temperature albeit at high exposure concentrations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of short-term very low-calorie diet on intramyocellular lipid and insulin sensitivity in nondiabetic and type 2 diabetic subjects.

PubMed

Lara-Castro, Cristina; Newcomer, Bradley R; Rowell, Jennifer; Wallace, Penny; Shaughnessy, Sara M; Munoz, A Julian; Shiflett, Alanna M; Rigsby, Dana Y; Lawrence, Jeannine C; Bohning, Daryl E; Buchthal, Steven; Garvey, W Timothy

2008-01-01

The study aimed to analyze the effects of a short-term very low-calorie diet (VLCD) on intramyocellular lipid (IMCL), total body fat, and insulin sensitivity in a group of obese nondiabetic and type 2 diabetic subjects. Seven untreated type 2 diabetic and 5 obese nondiabetic individuals were studied before and after a 6-day VLCD using proton magnetic resonance spectroscopy to quantify IMCL, dual-energy x-ray absorptiometry to assess body fat, and hyperinsulinemic-euglycemic clamps to measure peripheral insulin sensitivity. In both groups, decrements in total body fat mass and body mass index were small but statistically significant. In contrast, the diet resulted in a pronounced reduction in IMCL compared with baseline values in nondiabetic subjects (56% decrease) and type 2 diabetic subjects (40% decrease) (P < .05), and this was accompanied by an overall 9.3% increase in maximally stimulated glucose disposal rate (P < .01). Intramyocellular lipid was significantly correlated with insulin sensitivity (r = -0.69, P < .01) and waist circumference (r = 0.72 and 0.83, baseline and postdiet, respectively; both P < .01), but neither IMCL nor insulin sensitivity was related to measures of general adiposity such as body mass index, percentage of body fat, or total body fat (P = not significant). In conclusion, short-term VLCD is accompanied by small decrements in general adiposity, marked decrease in IMCL, and an increase in insulin sensitivity in nondiabetic and type 2 diabetic subjects. Therefore, rapid amelioration of insulin resistance by VLCD can be partially explained by loss of IMCL both in nondiabetic and type 2 diabetic subjects in the absence of substantial changes in total body fat. These observations are consistent with the idea that insulin resistance is more directly related to IMCL rather than to body fat per se.

Effects of Short-Term Very Low Calorie Diet on Intramyocellular Lipid and Insulin Sensitivity in Non-diabetics and Type 2 Diabetic Patients

PubMed Central

Lara-Castro, Cristina; Newcomer, Bradley R; Rowell, Jennifer; Wallace, Penny; Shaughnessy, Sara M; Munoz, A Julian; Shiflett, Alanna M; Rigsby, Dana Y; Lawrence, Jeannine C; Bohning, Daryl E; Buchthal, Steven; Garvey, W Timothy

2008-01-01

Objective To study the effects of a short-term very-low calorie diet (VLCD) on intramyocellular lipid (IMCL), total body fat, and insulin sensitivity in a group of obese non-diabetic and Type 2 Diabetic (T2DM) patients. Research Methods and Procedures Seven untreated T2DM and 5 obese non-diabetic individuals were studied before and after a 6-day VLCD using proton-magnetic resonance spectroscopy to quantify IMCL, DXA to assess body fat, and hyperinsulinemic-euglycemic clamps to measure peripheral insulin sensitivity. Results In both groups, decrements in total body fat mass and BMI were small but statistically significant. In contrast, the diet resulted in a pronounced reduction in IMCL compared to baseline values in non-diabetics (56% decrease) and T2DM (40% decrease), P<0.05, and this was accompanied by an overall 9.3% increase in maximally-stimulated glucose disposal rate (P<0.01). IMCL was significantly correlated with insulin sensitivity, (r=−0.69; P<0.01) and waist circumference (r = 0.72 and 0.83, baseline and post-diet respectively, both P < 0.01), but neither IMCL nor insulin sensitivity was related to measures of general adiposity such as BMI, % body fat, or total body fat (P=NS). Conclusions Short-term VLCD is accompanied by small decrements in general adiposity, marked decrease in IMCL, and an increase in insulin sensitivity in non-diabetic and T2DM subjects. Therefore, rapid amelioration of insulin resistance by VLCD can be partially explained by loss of IMCL in both non-diabetics and in T2DM in the absence of substantial changes in total body fat. These observations are consistent with the idea that insulin resistance is more directly related to IMCL rather than body fat per se. PMID:18078853

The magnitude and colour of noise in genetic negative feedback systems

PubMed Central

Voliotis, Margaritis; Bowsher, Clive G.

2012-01-01

The comparative ability of transcriptional and small RNA-mediated negative feedback to control fluctuations or ‘noise’ in gene expression remains unexplored. Both autoregulatory mechanisms usually suppress the average (mean) of the protein level and its variability across cells. The variance of the number of proteins per molecule of mean expression is also typically reduced compared with the unregulated system, but is almost never below the value of one. This relative variance often substantially exceeds a recently obtained, theoretical lower limit for biochemical feedback systems. Adding the transcriptional or small RNA-mediated control has different effects. Transcriptional autorepression robustly reduces both the relative variance and persistence (lifetime) of fluctuations. Both benefits combine to reduce noise in downstream gene expression. Autorepression via small RNA can achieve more extreme noise reduction and typically has less effect on the mean expression level. However, it is often more costly to implement and is more sensitive to rate parameters. Theoretical lower limits on the relative variance are known to decrease slowly as a measure of the cost per molecule of mean expression increases. However, the proportional increase in cost to achieve substantial noise suppression can be different away from the optimal frontier—for transcriptional autorepression, it is frequently negligible. PMID:22581772

Comparative Influence of Ocean Conditions on Yellowfin and Atlantic Bluefin Tuna Catch from Longlines in the Gulf of Mexico

PubMed Central

Teo, Steven L. H.; Block, Barbara A.

2010-01-01

Directed fishing effort for Atlantic bluefin tuna in the Gulf of Mexico (GOM), their primary spawning grounds in the western Atlantic, has been prohibited since the 1980s due to a precipitous decline of the spawning stock biomass. However, pelagic longlines targeted at other species, primarily yellowfin tuna and swordfish, continue to catch Atlantic bluefin tuna in the GOM as bycatch. Spatial and temporal management measures minimizing bluefin tuna bycatch in the GOM will likely become important in rebuilding the western Atlantic bluefin stock. In order to help inform management policy and understand the relative distribution of target and bycatch species in the GOM, we compared the spatiotemporal variability and environmental influences on the catch per unit effort (CPUE) of yellowfin (target) and bluefin tuna (bycatch). Catch and effort data from pelagic longline fisheries observers (1993–2005) and scientific tagging cruises (1998–2002) were coupled with environmental and biological data. Negative binomial models were used to fit the data for both species and Akaike's Information Criterion (corrected for small sample size) was used to determine the best model. Our results indicate that bluefin CPUE had higher spatiotemporal variability as compared to yellowfin CPUE. Bluefin CPUE increased substantially during the breeding months (March-June) and peaked in April and May, while yellowfin CPUE remained relatively high throughout the year. In addition, bluefin CPUE was significantly higher in areas with negative sea surface height anomalies and cooler sea surface temperatures, which are characteristic of mesoscale cyclonic eddies. In contrast, yellowfin CPUE was less sensitive to environmental variability. These differences in seasonal variability and sensitivity to environmental influences suggest that bluefin tuna bycatch in the GOM can be reduced substantially by managing the spatial and temporal distribution of the pelagic longline effort without substantially impacting yellowfin tuna catches. PMID:20526356

Chronic stress sensitizes rats to pancreatitis induced by cerulein: role of TNF-α.

PubMed

Binker, Marcelo-G; Binker-Cosen, Andres-A; Richards, Daniel; Gaisano, Herbert-Y; de Cosen, Rodica-H; Cosen-Binker, Laura-I

2010-11-28

To investigate chronic stress as a susceptibility factor for developing pancreatitis, as well as tumor necrosis factor-α (TNF-α) as a putative sensitizer. Rat pancreatic acini were used to analyze the influence of TNF-α on submaximal (50 pmol/L) cholecystokinin (CCK) stimulation. Chronic restraint (4 h every day for 21 d) was used to evaluate the effects of submaximal (0.2 μg/kg per hour) cerulein stimulation on chronically stressed rats. In vitro exposure of pancreatic acini to TNF-α disorganized the actin cytoskeleton. This was further increased by TNF-α/CCK treatment, which additionally reduced amylase secretion, and increased trypsin and nuclear factor-κB activities in a protein-kinase-C δ and ε-dependent manner. TNF-α/CCK also enhanced caspases' activity and lactate dehydrogenase release, induced ATP loss, and augmented the ADP/ATP ratio. In vivo, rats under chronic restraint exhibited elevated serum and pancreatic TNF-α levels. Serum, pancreatic, and lung inflammatory parameters, as well as caspases'activity in pancreatic and lung tissue, were substantially enhanced in stressed/cerulein-treated rats, which also experienced tissues' ATP loss and greater ADP/ATP ratios. Histological examination revealed that stressed/cerulein-treated animals developed abundant pancreatic and lung edema, hemorrhage and leukocyte infiltrate, and pancreatic necrosis. Pancreatitis severity was greatly decreased by treating animals with an anti-TNF-α-antibody, which diminished all inflammatory parameters, histopathological scores, and apoptotic/necrotic markers in stressed/cerulein-treated rats. In rats, chronic stress increases susceptibility for developing pancreatitis, which involves TNF-α sensitization of pancreatic acinar cells to undergo injury by physiological cerulein stimulation.

Response of corn markets to climate volatility under alternative energy futures.

PubMed

Diffenbaugh, Noah S; Hertel, Thomas W; Scherer, Martin; Verma, Monika

2012-07-01

Recent price spikes(1,2) have raised concern that climate change could increase food insecurity by reducing grain yields in the coming decades(3,4). However, commodity price volatility is also influenced by other factors(5,6), which may either exacerbate or buffer the effects of climate change. Here we show that US corn price volatility exhibits higher sensitivity to near-term climate change than to energy policy influences or agriculture-energy market integration, and that the presence of a biofuels mandate enhances the sensitivity to climate change by more than 50%. The climate change impact is driven primarily by intensification of severe hot conditions in the primary corn-growing region of the US, which causes US corn price volatility to increase sharply in response to global warming projected over the next three decades. Closer integration of agriculture and energy markets moderates the effects of climate change, unless the biofuels mandate becomes binding, in which case corn price volatility is instead exacerbated. However, in spite of the substantial impact on US corn price volatility, we find relatively small impact on food prices. Our findings highlight the critical importance of interactions between energy policies, energy-agriculture linkages, and climate change.

Modelling the effects of climate and land-use change on the hydrochemistry and ecology of the River Wye (Wales).

PubMed

Bussi, Gianbattista; Whitehead, Paul G; Gutiérrez-Cánovas, Cayetano; Ledesma, José L J; Ormerod, Steve J; Couture, Raoul-Marie

2018-06-15

Interactions between climate change and land use change might have substantial effects on aquatic ecosystems, but are still poorly understood. Using the Welsh River Wye as a case study, we linked models of water quality (Integrated Catchment - INCA) and climate (GFDL - Geophysical Fluid Dynamics Laboratory and IPSL - Institut Pierre Simon Laplace) under greenhouse gas scenarios (RCP4.5 and RCP8.5) to drive a bespoke ecosystem model that simulated the responses of aquatic organisms. The potential effects of economic and social development were also investigated using scenarios from the EU MARS project (Managing Aquatic Ecosystems and Water Resources under Multiple Stress). Longitudinal position along the river mediated response to increasing anthropogenic pressures. Upland locations appeared particularly sensitive to nutrient enrichment or potential re-acidification compared to lowland environments which are already eutrophic. These results can guide attempts to mitigate future impacts and reiterate the need for sensitive land management in upland, temperate environments which are likely to become increasingly important to water supply and biodiversity conservation as the effects of climate change intensify. Copyright © 2018 Elsevier B.V. All rights reserved.

Phenotypic, Functional, and Safety Control at Preimplantation Phase of MSC-Based Therapy.

PubMed

Lech, Wioletta; Figiel-Dabrowska, Anna; Sarnowska, Anna; Drela, Katarzyna; Obtulowicz, Patrycja; Noszczyk, Bartlomiej Henryk; Buzanska, Leonora; Domanska-Janik, Krystyna

2016-01-01

Mesenchymal stem cells (MSC) exhibit enormous heterogeneity which can modify their regenerative properties and therefore influence therapeutic effectiveness as well as safety of these cells transplantation. In addition the high phenotypic plasticity of MSC population makes it enormously sensitive to any changes in environmental properties including fluctuation in oxygen concentration. We have shown here that lowering oxygen level far below air atmosphere has a beneficial impact on various parameters characteristic for umbilical cord Wharton Jelly- (WJ-) MSC and adipose tissue- (AD-) derived MSC cultures. This includes their cellular composition, rate of proliferation, and maintenance of stemness properties together with commitment to cell differentiation toward mesodermal and neural lineages. In addition, the culture genomic stability increased significantly during long-term cell passaging and eventually protected cells against spontaneous transformation. Also by comparing of two routinely used methods of MSCs isolation (mechanical versus enzymatic) we have found substantial divergence arising between cell culture properties increasing along the time of cultivation in vitro. Thus, in this paper we highlight the urgent necessity to develop the more sensitive and selective methods for prediction and control cells fate and functioning during the time of growth in vitro.

Response of corn markets to climate volatility under alternative energy futures

PubMed Central

Diffenbaugh, Noah S.; Hertel, Thomas W.; Scherer, Martin; Verma, Monika

2012-01-01

Recent price spikes1,2 have raised concern that climate change could increase food insecurity by reducing grain yields in the coming decades3,4. However, commodity price volatility is also influenced by other factors5,6, which may either exacerbate or buffer the effects of climate change. Here we show that US corn price volatility exhibits higher sensitivity to near-term climate change than to energy policy influences or agriculture-energy market integration, and that the presence of a biofuels mandate enhances the sensitivity to climate change by more than 50%. The climate change impact is driven primarily by intensification of severe hot conditions in the primary corn-growing region of the US, which causes US corn price volatility to increase sharply in response to global warming projected over the next three decades. Closer integration of agriculture and energy markets moderates the effects of climate change, unless the biofuels mandate becomes binding, in which case corn price volatility is instead exacerbated. However, in spite of the substantial impact on US corn price volatility, we find relatively small impact on food prices. Our findings highlight the critical importance of interactions between energy policies, energy-agriculture linkages, and climate change. PMID:23243468

Corn-Based Ethanol Production and Environmental Quality: A Case of Iowa and the Conservation Reserve Program

NASA Astrophysics Data System (ADS)

Secchi, Silvia; Gassman, Philip W.; Williams, Jimmy R.; Babcock, Bruce A.

2009-10-01

Growing demand for corn due to the expansion of ethanol has increased concerns that environmentally sensitive lands retired from agricultural production and enrolled into the Conservation Reserve Program (CRP) will be cropped again. Iowa produces more ethanol than any other state in the United States, and it also produces the most corn. Thus, an examination of the impacts of higher crop prices on CRP land in Iowa can give insight into what we might expect nationally in the years ahead if crop prices remain high. We construct CRP land supply curves for various corn prices and then estimate the environmental impacts of cropping CRP land through the Environmental Policy Integrated Climate (EPIC) model. EPIC provides edge-of-field estimates of soil erosion, nutrient loss, and carbon sequestration. We find that incremental impacts increase dramatically as higher corn prices bring into production more and more environmentally fragile land. Maintaining current levels of environmental quality will require substantially higher spending levels. Even allowing for the cost savings that would accrue as CRP land leaves the program, a change in targeting strategies will likely be required to ensure that the most sensitive land does not leave the program.

[The research of UV-responsive sensitivity enhancement of fluorescent coating films by MgF2 layer].

PubMed

Lu, Zhong-Rong; Ni, Zheng-Ji; Tao, Chun-Xian; Hong, Rui-Jin; Zhang, Da-Wei; Huang, Yuan-Shen

2014-03-01

A low cost and less complicated expansion approach of wavelength responses with a Lumogen phosphor coating was adopted, as they increased the quantum efficiency of CCD and CMOS detectors in ultra-violet by absorbing UV light and then re emitting visible light. In this paper, the sensitivity enhancement of fluorescence coatings was studied by adding an anti-reflection film or barrier film to reduce the loss of the scattering and reflection on the incident interface. The Lumogen and MgF2/Lumogen film were deposited on quartz glasses by physical vacuum deposition. The surface morphology, transmittance spectrum, reflectance spectrum and fluorescence emission spectrum were obtained by atomic force microscope (AFM), spectrophotometer and fluorescence spectrometer, respectively. The results indicated that MgF2 film had obvious positive effect on reducing scattering and reflection loss in 500-700 nm, and enhancing the absorption of Lumogen coating in ultraviolet spectrum. Meanwhile, the fluorescent emission intensity had a substantial increase by smoothing the film surface and thus reducing the light scattering. At the same time, the MgF2 layer could protect Lumogen coating from damaging and contamination, which give a prolong lifetime of the UV-responsive CCD sensors with fluorescent coatings.

Accuracy of transvaginal ultrasound for diagnosis of deep endometriosis in uterosacral ligaments, rectovaginal septum, vagina and bladder: systematic review and meta-analysis.

PubMed

Guerriero, S; Ajossa, S; Minguez, J A; Jurado, M; Mais, V; Melis, G B; Alcazar, J L

2015-11-01

To review the diagnostic accuracy of transvaginal ultrasound (TVS) in the preoperative detection of endometriosis in the uterosacral ligaments (USL), rectovaginal septum (RVS), vagina and bladder in patients with clinical suspicion of deep infiltrating endometriosis (DIE). An extensive search was performed in MEDLINE (PubMed) and EMBASE for studies published between January 1989 and December 2014. Studies were considered eligible if they reported on the use of TVS for the preoperative detection of endometriosis in the USL, RVS, vagina and bladder in women with clinical suspicion of DIE using the surgical data as a reference standard. Study quality was assessed using the PRISMA guidelines and QUADAS-2 tool. Of the 801 citations identified, 11 studies (n = 1583) were considered eligible and were included in the meta-analysis. For detection of endometriosis in the USL, the overall pooled sensitivity and specificity of TVS were 53% (95%CI, 35-70%) and 93% (95%CI, 83-97%), respectively. The pretest probability of USL endometriosis was 54%, which increased to 90% when suspicion of endometriosis was present after TVS examination. For detection of endometriosis in the RVS, the overall pooled sensitivity and specificity were 49% (95%CI, 36-62%) and 98% (95%CI, 95-99%), respectively. The pretest probability of RVS endometriosis was 24%, which increased to 89% when suspicion of endometriosis was present after TVS examination. For detection of vaginal endometriosis, the overall pooled sensitivity and specificity were 58% (95%CI, 40-74%) and 96% (95%CI, 87-99%), respectively. The pretest probability of vaginal endometriosis was 17%, which increased to 76% when suspicion of endometriosis was present after TVS assessment. Substantial heterogeneity was found for sensitivity and specificity for all these locations. For detection of bladder endometriosis, the overall pooled sensitivity and specificity were 62% (95%CI, 40-80%) and 100% (95%CI, 97-100%), respectively. Moderate heterogeneity was found for sensitivity and specificity for bladder endometriosis. The pretest probability of bladder endometriosis was 5%, which increased to 92% when suspicion of endometriosis was present after TVS assessment. Overall diagnostic performance of TVS for detecting DIE in uterosacral ligaments, rectovaginal septum, vagina and bladder is fair with high specificity. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Increasing species richness of the macrozoobenthic fauna on tidal flats of the Wadden Sea by local range expansion and invasion of exotic species

NASA Astrophysics Data System (ADS)

Beukema, J. J.; Dekker, R.

2011-06-01

A 40-y series of consistently collected samples (15 fixed sampling sites, constant sampled area of 15 × 0.95 m2, annual sampling only in late-winter/early-spring seasons, and consistent sieving and sorting procedures; restriction to 50 easily recognizable species) of macrozoobenthos on Balgzand, a tidal flat area in the westernmost part of the Wadden Sea (The Netherlands), revealed significantly increasing trends of species richness. Total numbers of species annually encountered increased from ~28 to ~38. Mean species density (number of species found per sampling site) increased from ~13 to ~18 per 0.95 m2. During the 40 years of the 1970-2009 period of observation, 4 exotic species invaded the area: (in order of first appearance) Ensis directus, Marenzelleria viridis, Crassostrea gigas, and Hemigrapsus takanoi. Another 5 species recently moved to Balgzand from nearby (subtidal) locations. Together, these 9 new species on the tidal flats explained by far most of the increase in total species numbers, but accounted for only one-third of the observed increase in species density (as a consequence of the restricted distribution of most of them). Species density increased particularly by a substantial number of species that showed increasing trends in the numbers of tidal flat sites they occupied. Most of these wider-spreading species were found to suffer from cold winters. During the 40-y period of observation, winter temperatures rose by about 2°C and cold winters became less frequent. The mean number of cold-sensitive species found per site significantly increased by almost 2 per 0.95 m2. Among the other species (not sensitive to low winter temperatures), 6 showed a rising and 2 a declining trend in number of occupied sites, resulting in a net long-term increase in species density amounting to another gain of 1.6 per 0.95 m2. Half of the 50 studied species did not show such long-term trend, nor were invaders. Thus, each of 3 groups (local or alien invaders/winter-sensitive species/other increasing species) contributed to a roughly similar extent to the overall increase in species density.

A Web-Based Education Program for Colorectal Lesion Diagnosis with Narrow Band Imaging Classification.

PubMed

Aihara, Hiroyuki; Kumar, Nitin; Thompson, Christopher C

2018-04-19

An education system for narrow band imaging (NBI) interpretation requires sufficient exposure to key features. However, access to didactic lectures by experienced teachers is limited in the United States. To develop and assess the effectiveness of a colorectal lesion identification tutorial. In the image analysis pretest, subjects including 9 experts and 8 trainees interpreted 50 white light (WL) and 50 NBI images of colorectal lesions. Results were not reviewed with subjects. Trainees then participated in an online tutorial emphasizing NBI interpretation in colorectal lesion analysis. A post-test was administered and diagnostic yields were compared to pre-education diagnostic yields. Under the NBI mode, experts showed higher diagnostic yields (sensitivity 91.5% [87.3-94.4], specificity 90.6% [85.1-94.2], and accuracy 91.1% [88.5-93.7] with substantial interobserver agreement [κ value 0.71]) compared to trainees (sensitivity 89.6% [84.8-93.0], specificity 80.6% [73.5-86.3], and accuracy 86.0% [82.6-89.2], with substantial interobserver agreement [κ value 0.69]). The online tutorial improved the diagnostic yields of trainees to the equivalent level of experts (sensitivity 94.1% [90.0-96.6], specificity 89.0% [83.0-93.2], and accuracy 92.0% [89.3-94.7], p < 0.001 with substantial interobserver agreement [κ value 0.78]). This short, online tutorial improved diagnostic performance and interobserver agreement. © 2018 S. Karger AG, Basel.

mTOR ATP-competitive inhibitor INK128 inhibits neuroblastoma growth via blocking mTORC signaling

PubMed Central

Zhang, Huiyuan; Dou, Jun; Yu, Yang; Zhao, Yanling; Fan, Yihui; Cheng, Jin; Xu, Xin; Liu, Wei; Guan, Shan; Chen, Zhenghu; shi, Yan; Patel, Roma; Vasudevan, Sanjeev A; Zage, Peter E; Zhang, Hong; Nuchtern, Jed G; Kim, Eugene S; Fu, Songbin; Yang, Jianhua

2015-01-01

High-risk neuroblastoma often develops resistance to high-dose chemotherapy. The mTOR signaling cascade is frequently deregulated in human cancers and targeting mTOR signaling sensitizes many cancer types to chemotherapy. Here, using a panel of neuroblastoma cell lines, we found that the mTOR inhibitor INK128 showed inhibitory effects on both anchorage-dependent and independent growth of neuroblastoma cells and significantly enhanced the cytotoxic effects of doxorubicin (Dox) on these cell lines. Treatment of neuroblastoma cells with INK128 blocked the activation of downstream mTOR signaling and enhanced Dox-induced apoptosis. Moreover, INK128 was able to overcome the established chemoresistance in the LA-N-6 cell line. Using an orthotopic neuroblastoma mouse model, we found that INK128 significantly inhibited tumor growth in vivo. In conclusion, we have shown that INK128-mediated mTOR inhibition possessed substantial antitumor activity and could significantly increase the sensitivity of neuroblastoma cells to Doxorubicin therapy. Taken together, our results indicate that using INK128 can provide additional efficacy to current chemotherapeutic regimens and represent a new paradigm in restoring drug sensitivity in neuroblastoma. PMID:25425103

Validity and usefulness of the Line Drill test for adolescent basketball players: a Bayesian multilevel analysis.

PubMed

Carvalho, Humberto M; Gonçalves, Carlos E; Grosgeorge, Bernard; Paes, Roberto R

2017-01-01

The study examined the validity of the Line Drill test (LD) in male adolescent basketball players (10-15 years). Sensitiveness of the LD to changes in performance across a training and competition season (4 months) was also considered. Age, maturation, body size and LD were measured (n = 57). Sensitiveness of the LD was examined pre- and post-competitive season in a sub-sample (n = 44). The time at each of the four shuttle sprints of the LD (i.e. four stages) was modelled with Bayesian multilevel models. We observed very large correlation of performance at stage 4 (full LD protocol) with stage 3, but lower correlations with the early LD stages. Players' performance by somatic maturity differed substantially only when considering full LD protocol performance. Substantial improvements in all stages of the protocol were observed across the 4-month competitive season. The LD protocol should be shortened by the last full court shuttle sprint, remaining sensitive to training exposure, and independent of maturity status and body size.

Large angle solid state position sensitive x-ray detector system

DOEpatents

Kurtz, D.S.; Ruud, C.O.

1998-03-03

A method and apparatus for x-ray measurement of certain properties of a solid material are disclosed. In distinction to known methods and apparatus, this invention employs a specific fiber-optic bundle configuration, termed a reorganizer, itself known for other uses, for coherently transmitting visible light originating from the scintillation of diffracted x-radiation from the solid material gathered along a substantially one dimensional linear arc, to a two-dimensional photo-sensor array. The two-dimensional photodetector array, with its many closely packed light sensitive pixels, is employed to process the information contained in the diffracted radiation and present the information in the form of a conventional x-ray diffraction spectrum. By this arrangement, the angular range of the combined detector faces may be increased without loss of angular resolution. Further, the prohibitively expensive coupling together of a large number of individual linear diode photodetectors, which would be required to process signals generated by the diffracted radiation, is avoided. 7 figs.

Large angle solid state position sensitive x-ray detector system

DOEpatents

Kurtz, D.S.; Ruud, C.O.

1998-07-21

A method and apparatus are disclosed for x-ray measurement of certain properties of a solid material. In distinction to known methods and apparatus, this invention employs a specific fiber-optic bundle configuration, termed a reorganizer, itself known for other uses, for coherently transmitting visible light originating from the scintillation of diffracted x-radiation from the solid material gathered along a substantially one dimensional linear arc, to a two-dimensional photo-sensor array. The two-dimensional photodetector array, with its many closely packed light sensitive pixels, is employed to process the information contained in the diffracted radiation and present the information in the form of a conventional x-ray diffraction spectrum. By this arrangement, the angular range of the combined detector faces may be increased without loss of angular resolution. Further, the prohibitively expensive coupling together of a large number of individual linear diode photodetectors, which would be required to process signals generated by the diffracted radiation, is avoided. 7 figs.

Defect-Mediated Molecular Interaction and Charge Transfer in Graphene Mesh-Glucose Sensors.

PubMed

Kwon, Sun Sang; Shin, Jae Hyeok; Choi, Jonghyun; Nam, SungWoo; Park, Won Il

2017-04-26

We report the role of defects in enzymatic graphene field-effect transistor sensors by introducing engineered defects in graphene channels. Compared with conventional graphene sensors (Gr sensors), graphene mesh sensors (GM sensors), with an array of circular holes, initially exhibited a higher irreversible response to glucose, involving strong chemisorption to edge defects. However, after immobilization of glucose oxidase, the irreversibility of the responses was substantially diminished, without any reduction in the sensitivity of the GM sensors (i.e., -0.53 mV/mM for the GM sensor vs -0.37 mV/mM for Gr sensor). Furthermore, multiple cycle operation led to rapid sensing and improved the reversibility of GM sensors. In addition, control tests with sensors containing a linker showed that sensitivity was increased in Gr sensors but decreased in GM sensors. Our findings indicate that edge defects can be used to replace linkers for immobilization of glucose oxidase and improve charge transfer across glucose oxidase-graphene interfaces.

Responsibility-sensitive fairness in health financing: judgments in four European countries.

PubMed

Le Clainche, Christine; Wittwer, Jerome

2015-04-01

Risky health behaviours substantially increase medical and social costs. We document the extent to which a sample of European students (from Denmark, France, Italy and Sweden) consider that individuals should assume the financial burden of paying the costs of risky behaviour. We test the acceptability of different ways of financing costs because of ill health that is more or less associated with risky behaviour in accordance with a normative framework relating to responsibility-sensitive fairness. We find that the majority of students agree with assuming financial responsibility for risky behaviours and that there should be compensation for unfavourable circumstances. Students agree that two individuals with the same responsibility variables should make an equal financial contribution and that more effort in maintaining health for given circumstances should be rewarded with a lower financial contribution. The specific health context and the type of risky behaviours involved matter in determining perceptions of justice in health financing. Copyright © 2014 John Wiley & Sons, Ltd.

Human serum albumin adsorption study on 62-MHz miniaturized quartz gravimetric sensors.

PubMed

Kao, Ping; Patwardhan, Ashish; Allara, David; Tadigadapa, Srinivas

2008-08-01

We have designed and fabricated 25-microm-thick quartz resonators operating at a fundamental resonance frequency of approximately 62 MHz. The results show a substantial increase in the mass sensitivity compared to single monolithic commercial resonators operating at lower frequencies in the approximately 5-10-MHz range. The overall performance of the micromachined resonators is demonstrated for the example of human serum albumin protein adsorption from aqueous buffer solutions onto gold electrodes functionalized with self-assembled monolayers. The results show a saturation adsorption frequency change of 6.8 kHz as opposed to 40 Hz for a commercial approximately 5-MHz sensor under identical loading conditions. From the analysis of the adsorption isotherm, the equilibrium adsorption constant of the adsorption of the protein layer was found to be K = 8.03 x 10(6) M(-1), which is in agreement with the values reported in the literature. The high sensitivity of the miniaturized QCM devices can be a significant advantage in both vapor and solution adsorption analyses.

Cs2AgBiBr6 single-crystal X-ray detectors with a low detection limit

NASA Astrophysics Data System (ADS)

Pan, Weicheng; Wu, Haodi; Luo, Jiajun; Deng, Zhenzhou; Ge, Cong; Chen, Chao; Jiang, Xiaowei; Yin, Wan-Jian; Niu, Guangda; Zhu, Lujun; Yin, Lixiao; Zhou, Ying; Xie, Qingguo; Ke, Xiaoxing; Sui, Manling; Tang, Jiang

2017-11-01

Sensitive X-ray detection is crucial for medical diagnosis, industrial inspection and scientific research. The recently described hybrid lead halide perovskites have demonstrated low-cost fabrication and outstanding performance for direct X-ray detection, but they all contain toxic Pb in a soluble form. Here, we report sensitive X-ray detectors using solution-processed double perovskite Cs2AgBiBr6 single crystals. Through thermal annealing and surface treatment, we largely eliminate Ag+/Bi3+ disordering and improve the crystal resistivity, resulting in a detector with a minimum detectable dose rate as low as 59.7 nGyair s-1, comparable to the latest record of 0.036 μGyair s-1 using CH3NH3PbBr3 single crystals. Suppressed ion migration in Cs2AgBiBr6 permits relatively large external bias, guaranteeing efficient charge collection without a substantial increase in noise current and thus enabling the low detection limit.

Evidence of health benefits of canola oil

PubMed Central

Lin, Lin; Allemekinders, Hanja; Dansby, Angela; Campbell, Lisa; Durance-Tod, Shaunda; Berger, Alvin; Jones, Peter JH

2013-01-01

Canola oil-based diets have been shown to reduce plasma cholesterol levels in comparison with diets containing higher levels of saturated fatty acids. Consumption of canola oil also influences biological functions that affect various other biomarkers of disease risk. Previous reviews have focused on the health effects of individual components of canola oil. Here, the objective is to address the health effects of intact canola oil, as this has immediate practical implications for consumers, nutritionists, and others deciding which oil to consume or recommend. A literature search was conducted to examine the effects of canola oil consumption on coronary heart disease, insulin sensitivity, lipid peroxidation, inflammation, energy metabolism, and cancer cell growth. Data reveal substantial reductions in total cholesterol and low-density lipoprotein cholesterol, as well as other positive actions, including increased tocopherol levels and improved insulin sensitivity, compared with consumption of other dietary fat sources. In summary, growing scientific evidence supports the use of canola oil, beyond its beneficial actions on circulating lipid levels, as a health-promoting component of the diet. PMID:23731447

Syncope or seizure? The diagnostic value of the EEG and hyperventilation test in transient loss of consciousness.

PubMed Central

Hoefnagels, W A; Padberg, G W; Overweg, J; Roos, R A; van Dijk, J G; Kamphuisen, H A

1991-01-01

In a prospective study of consecutive patients (age 15 or over) with transient loss of consciousness 45 patients had a history of seizure and 74 patients had a history of syncope. All patients had an EEG, ECG, laboratory tests and a hyperventilation test and were followed for an average of 14.5 months. Epileptiform activity in the interictal EEG had a sensitivity of 0.40 and a specificity of 0.95 for the diagnosis of a seizure. Epileptiform activity nearly doubled the probability of a seizure in doubtful cases. If no epileptiform activity was found, this probability remained substantially the same. The hyperventilation test had a sensitivity of 0.57 and a specificity of 0.84 for the diagnosis of syncope. A positive test increased the probability of syncope half as much in doubtful cases. A negative test did not exclude syncope. Laboratory tests were not helpful except for an ECG which was helpful in elderly patients. PMID:1800665

Novel insights on diagnosis, cause and treatment of diabetic neuropathy: focus on painful diabetic neuropathy

PubMed Central

Tavakoli, Mitra; Asghar, Omar; Alam, Uazman; Petropoulos, Ioannis N.; Fadavi, Hassan; Malik, Rayaz A.

2010-01-01

Diabetic neuropathy is common, under or misdiagnosed, and causes substantial morbidity with increased mortality. Defining and developing sensitive diagnostic tests for diabetic neuropathy is not only key to implementing earlier interventions but also to ensure that the most appropriate endpoints are employed in clinical intervention trials. This is critical as many potentially effective therapies may never progress to the clinic, not due to a lack of therapeutic effect, but because the endpoints were not sufficiently sensitive or robust to identify benefit. Apart from improving glycaemic control, there is no licensed treatment for diabetic neuropathy, however, a number of pathogenetic pathways remain under active study. Painful diabetic neuropathy is a cause of considerable morbidity and whilst many pharmacological and nonpharmacological interventions are currently used, only two are approved by the US Food and Drug Administration. We address the important issue of the ‘placebo effect’ and also consider potential new pharmacological therapies as well as nonpharmacological interventions in the treatment of painful diabetic neuropathy. PMID:23148152

Perendoscopic gastric pH determination. Simple method for increasing accuracy in diagnosing chronic atrophic gastritis.

PubMed

Farinati, F; Cardin, F; Di Mario, F; Sava, G A; Piccoli, A; Costa, F; Penon, G; Naccarato, R

1987-08-01

The endoscopic diagnosis of chronic atrophic gastritis is often underestimated, and most of the procedures adopted to increase diagnostic accuracy are time consuming and complex. In this study, we evaluated the usefulness of the determination of gastric juice pH by means of litmus paper. Values obtained by this method correlate well with gastric acid secretory capacity as measured by gastric acid analysis (r = -0.64, p less than 0.001) and are not affected by the presence of bile. Gastric juice pH determination increases sensitivity and other diagnostic parameters such as performance index (Youden J test), positive predictive value, and post-test probability difference by 50%. Furthermore, the negative predictive value is very high, the probability of missing a patient with chronic atrophic gastritis with this simple method being 2% for fundic and 15% for antral atrophic change. We conclude that gastric juice pH determination, which substantially increases diagnostic accuracy and is very simple to perform, should be routinely adopted.

Density of photonic states in cholesteric liquid crystals

NASA Astrophysics Data System (ADS)

Dolganov, P. V.

2015-04-01

Density of photonic states ρ (ω ) , group vg, and phase vph velocity of light, and the dispersion relation between wave vector k , and frequency ω (k ) were determined in a cholesteric photonic crystal. A highly sensitive method (measurement of rotation of the plane of polarization of light) was used to determine ρ (ω ) in samples of different quality. In high-quality samples a drastic increase in ρ (ω ) near the boundaries of the stop band and oscillations related to Pendellösung beatings are observed. In low-quality samples photonic properties are strongly modified. The maximal value of ρ (ω ) is substantially smaller, and density of photonic states increases near the selective reflection band without oscillations in ρ (ω ) . Peculiarities of ρ (ω ) , vg, and ω (k ) are discussed. Comparison of the experimental results with theory was performed.

Clostridium difficile

PubMed Central

Curry, Scott R.

2017-01-01

SYNOPSIS Clostridium difficile infections (CDI) have emerged as one of the principal threats to the health of hospitalized and immunocompromised patients. Nucleic acid testing for C. difficile toxin genes has eclipsed traditional clinical diagnostics for CDI in sensitivity and is now widespread in clinical use, but preliminary evidence suggests that this may have come at a cost of substantially reduced positive predictive value. The importance of C. difficile colonization is increasingly recognized not only as a source for false positive clinical testing but also as a source of new infections within hospitals and other healthcare environments. In the last five years, several new treatment strategies that capitalize on the increasing understanding of the altered microbiome and host defenses in CDI patients have completed clinical trials, including fecal microbiota transplantation (FMT). This article highlights the changing epidemiology, laboratory diagnostics, pathogenesis, and treatment of CDI. PMID:20513554

The solubility of olivine in basaltic liquids - An ionic model

NASA Technical Reports Server (NTRS)

Herzberg, C. T.

1979-01-01

A model is presented which enables the temperature at which olivine is in equilibrium with any alkali-depleted basaltic compound to be calculated to within + or - 30 C. It is noted that the error increases substantially when applied to terrestrial basalts which contain several weight percent alkalis. In addition the model predicts and quantifies the reduced activity of SiO4(4-) monomers due to increasing SiO2 concentrations in the melt. It is shown that the coordination of alumina in melts which precipitate olivine only appears to be dominantly octahedral, while titanium acts as a polmerizing agent by interconnecting previously isolated SiO4(4-) monomers. It is concluded that the model is sufficiently sensitive to show that there are small repulsive forces between Mg(2+) and calcium ions which are in association with normative diopside in the melt.

Low Bandwidth Robust Controllers for Flight

NASA Technical Reports Server (NTRS)

Biezad, Daniel J.; Chou, Hwei-Lan

1993-01-01

Through throttle manipulations, engine thrust can be used for emergency flight control for multi-engine aircraft. Previous study by NASA Dryden has shown the use of throttles for emergency flight control to be very difficult. In general, manual fly-by-throttle is extremely difficult - with landing almost impossible, but control augmentation makes runway landings feasible. Flight path control using throttles-only to achieve safe emergency landing for a large jet transport airplane, Boeing 720, was investigated using Quantitative Feedback Theory (QFT). Results were compared to an augmented control developed in a previous simulation study. The control augmentation corrected the unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but increasing the control bandwidth substantially proved very difficult. The augmented pitch control is robust under no or moderate turbulence. The augmented roll control is sensitive to configuration changes.

Low bandwidth robust controllers for flight

NASA Technical Reports Server (NTRS)

Biezad, Daniel J.; Chou, Hwei-Lan

1993-01-01

Through throttle manipulations, engine thrust can be used for emergency flight control for multi-engine aircraft. Previous study by NASA Dryden has shown the use of throttles for emergency flight control to be very difficult. In general, manual fly-by-throttle is extremely difficult - with landing almost impossible, but control augmentation makes runway landings feasible. Flight path control using throttles-only to achieve safe emergency landing for a large jet transport airplane, Boeing 720, was investigated using Quantitative Feedback Theory (QFT). Results were compared to an augmented control developed in a previous simulation study. The control augmentation corrected the unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but increasing the control bandwidth substantially proved very difficult. The augmented pitch control is robust under no or moderate turbulence. The augmented roll control is sensitive to configuration changes.

Classifying elementary cellular automata using compressibility, diversity and sensitivity measures

NASA Astrophysics Data System (ADS)

Ninagawa, Shigeru; Adamatzky, Andrew

2014-10-01

An elementary cellular automaton (ECA) is a one-dimensional, synchronous, binary automaton, where each cell update depends on its own state and states of its two closest neighbors. We attempt to uncover correlations between the following measures of ECA behavior: compressibility, sensitivity and diversity. The compressibility of ECA configurations is calculated using the Lempel-Ziv (LZ) compression algorithm LZ78. The sensitivity of ECA rules to initial conditions and perturbations is evaluated using Derrida coefficients. The generative morphological diversity shows how many different neighborhood states are produced from a single nonquiescent cell. We found no significant correlation between sensitivity and compressibility. There is a substantial correlation between generative diversity and compressibility. Using sensitivity, compressibility and diversity, we uncover and characterize novel groupings of rules.

Impact of Wind and Solar on the Value of Energy Storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Denholm, Paul; Jorgenson, Jennie; Hummon, Marissa

2013-11-01

This analysis evaluates how the value of energy storage changes when adding variable generation (VG) renewable energy resources to the grid. A series of VG energy penetration scenarios from 16% to 55% were generated for a utility system in the western United States. This operational value of storage (measured by its ability to reduce system production costs) was estimated in each VG scenario, considering provision of different services and with several sensitivities to fuel price and generation mix. Overall, the results found that the presence of VG increases the value of energy storage by lowering off-peak energy prices more thanmore » on-peak prices, leading to a greater opportunity to arbitrage this price difference. However, significant charging from renewables, and consequently a net reduction in carbon emissions, did not occur until VG penetration was in the range of 40%-50%. Increased penetration of VG also increases the potential value of storage when providing reserves, mainly by increasing the amount of reserves required by the system. Despite this increase in value, storage may face challenges in capturing the full benefits it provides. Due to suppression of on-/off-peak price differentials, reserve prices, and incomplete capture of certain system benefits (such as the cost of power plant starts), the revenue obtained by storage in a market setting appears to be substantially less than the net benefit (reduction in production costs) provided to the system. Furthermore, it is unclear how storage will actually incentivize large-scale deployment of renewables needed to substantially increase VG penetration. This demonstrates some of the additional challenges for storage deployed in restructured energy markets.« less

Improved Sensitivity for Molecular Detection of Bacterial and Candida Infections in Blood

PubMed Central

Bacconi, Andrea; Richmond, Gregory S.; Baroldi, Michelle A.; Laffler, Thomas G.; Blyn, Lawrence B.; Carolan, Heather E.; Frinder, Mark R.; Toleno, Donna M.; Metzgar, David; Gutierrez, Jose R.; Massire, Christian; Rounds, Megan; Kennel, Natalie J.; Rothman, Richard E.; Peterson, Stephen; Carroll, Karen C.; Wakefield, Teresa; Ecker, David J.

2014-01-01

The rapid identification of bacteria and fungi directly from the blood of patients with suspected bloodstream infections aids in diagnosis and guides treatment decisions. The development of an automated, rapid, and sensitive molecular technology capable of detecting the diverse agents of such infections at low titers has been challenging, due in part to the high background of genomic DNA in blood. PCR followed by electrospray ionization mass spectrometry (PCR/ESI-MS) allows for the rapid and accurate identification of microorganisms but with a sensitivity of about 50% compared to that of culture when using 1-ml whole-blood specimens. Here, we describe a new integrated specimen preparation technology that substantially improves the sensitivity of PCR/ESI-MS analysis. An efficient lysis method and automated DNA purification system were designed for processing 5 ml of whole blood. In addition, PCR amplification formulations were optimized to tolerate high levels of human DNA. An analysis of 331 specimens collected from patients with suspected bloodstream infections resulted in 35 PCR/ESI-MS-positive specimens (10.6%) compared to 18 positive by culture (5.4%). PCR/ESI-MS was 83% sensitive and 94% specific compared to culture. Replicate PCR/ESI-MS testing from a second aliquot of the PCR/ESI-MS-positive/culture-negative specimens corroborated the initial findings in most cases, resulting in increased sensitivity (91%) and specificity (99%) when confirmed detections were considered true positives. The integrated solution described here has the potential to provide rapid detection and identification of organisms responsible for bloodstream infections. PMID:24951806

Impulsivity in spontaneously hypertensive rats: Within-subjects comparison of sensitivity to delay and to amount of reinforcement.

PubMed

Orduña, Vladimir; Mercado, Eduardo

2017-06-15

Previous research has shown that spontaneously hypertensive rats (SHR) display higher levels of impulsive choice behavior, which is accompanied by a higher sensitivity to the delay of reinforcement, and by a normal sensitivity to the amount of reinforcement. Because those results were based on three different samples of subjects, in the present report we evaluated these three processes in the same individuals. SHR and WIS rats were exposed to concurrent-chains schedules in which the terminal links were manipulated to assess impulsivity, sensitivity to delay, and sensitivity to amount. For exploring impulsivity, a terminal link was associated with a small reinforcer (1 pellet) delivered after a short delay (2s) while the other terminal link was associated with a larger reinforcer (4 pellets) delivered after a longer delay (28s). For assessing sensitivity to delay, both alternatives delivered the same amount of reinforcement (1 pellet) and the only difference between them was in the delay before reinforcement delivery (2s vs 28s). For assessing sensitivity to amount, both alternatives were associated with the same delay (15s), but the alternatives differed in the amount of reinforcement (1 vs 4 pellets). In addition to replicating previously observed effects within-subjects, we were interested in analyzing different aspects of the regularity of rats' actions in the choice task. The results confirmed that previous findings were not a consequence of between-group differences: SHR were more impulsive and more sensitive to delay, while their sensitivity to amount was normal. Analyses of response regularity indicated that SHR subjects were more periodic in their responses to levers and in their feeder entries, had a higher number of short-duration bouts of responding, and made a substantially higher number of switches between the alternatives. We discuss the potential implications of these findings for the possible behavioral mechanisms driving the increased sensitivity to delay in SHR. Copyright © 2017 Elsevier B.V. All rights reserved.

Scalp and skull influence on near infrared photon propagation in the Colin27 brain template.

PubMed

Strangman, Gary E; Zhang, Quan; Li, Zhi

2014-01-15

Near-infrared neuromonitoring (NIN) is based on near-infrared spectroscopy (NIRS) measurements performed through the intact scalp and skull. Despite the important effects of overlying tissue layers on the measurement of brain hemodynamics, the influence of scalp and skull on NIN sensitivity are not well characterized. Using 3555 Monte Carlo simulations, we estimated the sensitivity of individual continuous-wave NIRS measurements to brain activity over the entire adult human head by introducing a small absorption perturbation to brain gray matter and quantifying the influence of scalp and skull thickness on this sensitivity. After segmenting the Colin27 template into five tissue types (scalp, skull, cerebrospinal fluid, gray matter and white matter), the average scalp thickness was 6.9 ± 3.6 mm (range: 3.6-11.2mm), while the average skull thickness was 6.0 ± 1.9 mm (range: 2.5-10.5mm). Mean NIN sensitivity - defined as the partial path length through gray matter divided by the total photon path length - ranged from 0.06 (i.e., 6% of total path length) at a 20mm source-detector separation, to over 0.19 at 50mm separations. NIN sensitivity varied substantially around the head, with occipital pole exhibiting the highest NIRS sensitivity to gray matter, whereas inferior frontal regions had the lowest sensitivity. Increased scalp and skull thickness were strongly associated with decreased sensitivity to brain tissue. Scalp thickness always exhibited a slightly larger effect on sensitivity than skull thickness, but the effect of both varied with SD separation. We quantitatively characterize sensitivity around the head as well as the effects of scalp and skull, which can be used to interpret NIN brain activation studies as well as guide the design, development and optimization of NIRS devices and sensors. Copyright © 2013 Elsevier Inc. All rights reserved.

Superconductor-insulator quantum phase transition in disordered FeSe thin films.

PubMed

Schneider, R; Zaitsev, A G; Fuchs, D; V Löhneysen, H

2012-06-22

The evolution of two-dimensional electronic transport with increasing disorder in epitaxial FeSe thin films is studied. Disorder is generated by reducing the film thickness. The extreme sensitivity of the films to disorder results in a superconductor-insulator transition. The finite-size scaling analysis in the critical regime based on the Bose-glass model strongly supports the idea of a continuous quantum phase transition. The obtained value for the critical-exponent product of approximately 7/3 suggests that the transition is governed by quantum percolation. Finite-size scaling with the same critical-exponent product is also substantiated when the superconductor-insulator transition is tuned with an applied magnetic field.

The Role of Rough Topography in Mediating Impacts of Bottom Drag in Eddying Ocean Circulation Models.

PubMed

Trossman, David S; Arbic, Brian K; Straub, David N; Richman, James G; Chassignet, Eric P; Wallcraft, Alan J; Xu, Xiaobiao

2017-08-01

Motivated by the substantial sensitivity of eddies in two-layer quasi-geostrophic (QG) turbulence models to the strength of bottom drag, this study explores the sensitivity of eddies in more realistic ocean general circulation model (OGCM) simulations to bottom drag strength. The OGCM results are interpreted using previous results from horizontally homogeneous, two-layer, flat-bottom, f-plane, doubly periodic QG turbulence simulations and new results from two-layer β -plane QG turbulence simulations run in a basin geometry with both flat and rough bottoms. Baroclinicity in all of the simulations varies greatly with drag strength, with weak drag corresponding to more barotropic flow and strong drag corresponding to more baroclinic flow. The sensitivity of the baroclinicity in the QG basin simulations to bottom drag is considerably reduced, however, when rough topography is used in lieu of a flat bottom. Rough topography reduces the sensitivity of the eddy kinetic energy amplitude and horizontal length scales in the QG basin simulations to bottom drag to an even greater degree. The OGCM simulation behavior is qualitatively similar to that in the QG rough bottom basin simulations in that baroclinicity is more sensitive to bottom drag strength than are eddy amplitudes or horizontal length scales. Rough topography therefore appears to mediate the sensitivity of eddies in models to the strength of bottom drag. The sensitivity of eddies to parameterized topographic internal lee wave drag, which has recently been introduced into some OGCMs, is also briefly discussed. Wave drag acts like a strong bottom drag in that it increases the baroclinicity of the flow, without strongly affecting eddy horizontal length scales.

Emergency department spirometric volume and base deficit delineate risk for torso injury in stable patients

PubMed Central

Dunham, C Michael; Sipe, Eilynn K; Peluso, LeeAnn

2004-01-01

Background We sought to determine torso injury rates and sensitivities associated with fluid-positive abdominal ultrasound, metabolic acidosis (increased base deficit and lactate), and impaired pulmonary physiology (decreased spirometric volume and PaO2/FiO2). Methods Level I trauma center prospective pilot and post-pilot study (2000–2001) of stable patients. Increased base deficit was < 0.0 in ethanol-negative and ≤ -3.0 in ethanol-positive patients. Increased lactate was > 2.5 mmol/L in ethanol-negative and ≥ 3.0 mmol/L in ethanol-positive patients. Decreased PaO2/FiO2 was < 350 and decreased spirometric volume was < 1.8 L. Results Of 215 patients, 66 (30.7%) had a torso injury (abdominal/pelvic injury n = 35 and/or thoracic injury n = 43). Glasgow Coma Scale score was 14.8 ± 0.5 (13–15). Torso injury rates and sensitivities were: abdominal ultrasound negative and normal base deficit, lactate, PaO2/FiO2, and spirometric volume – 0.0% & 0.0%; normal base deficit and normal spirometric volume – 4.2% & 4.5%; chest/abdominal soft tissue injury – 37.8% & 47.0%; increased lactate – 39.7% & 47.0%; increased base deficit – 41.3% & 75.8%; increased base deficit and/or decreased spirometric volume – 43.8% & 95.5%; decreased PaO2/FiO2 – 48.9% & 33.3%; positive abdominal ultrasound – 62.5% & 7.6%; decreased spirometric volume – 73.4% & 71.2%; increased base deficit and decreased spirometric volume – 82.9% & 51.5%. Conclusions Trauma patients with normal base deficit and spirometric volume are unlikely to have a torso injury. Patients with increased base deficit or lactate, decreased spirometric volume, decreased PaO2/FiO2, or positive FAST have substantial risk for torso injury. Increased base deficit and/or decreased spirometric volume are highly sensitive for torso injury. Base deficit and spirometric volume values are readily available and increase or decrease the suspicion for torso injury. PMID:14731306

pH regulation in barnacle muscle fibers: dependence on extracellular sodium and bicarbonate.

PubMed

Boron, W F; McCormick, W C; Roos, A

1981-01-01

Intracellular pH (pHi) regulation was studied in barnacle muscle fibers with pH-sensitive microelectrodes. The cells were acid loaded, and the subsequent recovery of pHi was monitored. The rate of recovery was reduced by one-third when external Na+ ([Na+]o) was replaced by Li+, but recovery was completely abolished when Na+ was replaced by choline or N-methyl-D-glucamine. In other experiments, varying amounts of Na+ were replaced by choline, and the acid extrusion rate, derived from the recovery rate of pHi, was calculated at a single value of pHi, 6.80. The dependence of the acid extrusion rate on [Na+]o could be described by Michaelis-Menten kinetics; at pHo (extracellular) = 8.0 and [HCO3-]o (extracellular) = 10 mM, the apparent Km and Vmax were 59 mM and 1.3 mmol x l(-1) x min-1. When [HCO3-]o was reduced to 2.5 mM at the same pHo, Km did not change significantly, but Vmax was substantially reduced. On the other hand, when pHo was reduced to 7.4 at constant [HCO3-]o, Vmax changed only slightly, but Km increased substantially. In similar experiments, we examined the dependence of the acid extrusion rate on [HCO3-]o. At pHo = 8.0 and [Na+]o = 440 mM, the apparent Km and Vmax were 4.1 mM and 2.1 mmol x 1-1 x min-1. When pHo was reduced to 7.4, Vmax was not altered, but Km substantially increased. The kinetic data are discussed in terms of the role of pHo, [Na+]o, and [HCO3-]o in the pHi-regulating system.

Screening for delirium with the Intensive Care Delirium Screening Checklist (ICDSC): Symptom profile and utility of individual items in the identification of delirium dependent on the level of sedation.

PubMed

Boettger, Soenke; Meyer, Rafael; Richter, André; Fernandez, Susana Franco; Rudiger, Alain; Schubert, Maria; Jenewein, Josef; Nuñez, David Garcia

2018-05-24

The importance of the proper identification of delirium, with its high incidence and adversities in the intensive care setting, has been widely recognized. One common screening instrument is the Intensive Care Delirium Screening Checklist (ICDSC); however, the symptom profile and key features of delirium dependent on the level of sedation have not yet been evaluated. In this prospective cohort study, the ICDSC was evaluated versus the Diagnostic and Statistical Manual, 4th edition, text revision, diagnosis of delirium set as standard with respect to the symptom profile, and correct identification of delirium. The aim of this study was to identify key features of delirium in the intensive care setting dependent on the Richmond Agitation and Sedation Scale levels of sedation: drowsiness versus alert and calmness.ResultThe 88 delirious patients of 225 were older, had more severe disease, and prolonged hospitalization. Irrespective of the level of sedation, delirium was correctly classified by items related to inattention, disorientation, psychomotor alterations, inappropriate speech or mood, and symptom fluctuation. In the drowsy patients, inattention reached substantial sensitivity and specificity, whereas psychomotor alterations and sleep-wake cycle disturbances were sensitive lacked specificity. The positive prediction was substantial across items, whereas the negative prediction was only moderate. In the alert and calm patient, the sensitivities were substantial for psychomotor alterations, sleep-wake cycle disturbances, and symptom fluctuations; however, these fluctuations were not specific. The positive prediction was moderate and the negative prediction substantial. Between the nondelirious drowsy and alert, the symptom profile was similar; however, drowsiness was associated with alterations in consciousness.Significance of resultsIn the clinical routine, irrespective of the level of sedation, delirium was characterized by the ICDSC items for inattention, disorientation, psychomotor alterations, inappropriate speech or mood and symptom fluctuation. Further, drowsiness caused altered levels of consciousness.

Recommendation to increase the test concentration of methylchloroisothiazolinone/methylisothiazolinone in the European baseline patch test series - on behalf of the European Society of Contact Dermatitis and the European Environmental and Contact Dermatitis Research Group.

PubMed

Bruze, Magnus; Goossens, An; Isaksson, Marléne

2014-07-01

Methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) in aqua is present in the European baseline patch test series at 100 ppm, whereas 200 ppm has been used in Sweden since 1986, in Spain in the late 1980s, and, in recent years, also in the United Kingdom and Ireland. With regard to MCI/MI, to investigate the data on contact allergy rates in dermatitis patients, the frequencies of allergic contact dermatitis in the same group, and adverse reactions, particularly patch test sensitization in tested dermatitis patients, and to find the optimal patch test concentration as dose in mg/cm(2) . We performed a survey of the literature found via the National Library of Medicine (PubMed, http://www.ncbi.nlm.nih.gov/pubmed, last accessed 20 February 2014). MCI/MI at 200 ppm aq. diagnosis substantially more contact allergy and allergic contact dermatitis, without any registered increase in patch test sensitization, than the presently used concentration of 100 ppm. MCI/MI at 200 ppm aq. is recommended to be included in the European baseline patch test series. To avoid patch test sensitization, a dose of 0.006 mg/cm(2) must not be exceeded, which means a volume of 15 µl for Finn Chambers(®) (Ø 8 mm). © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Changes in Temperature Sensitivity and Activation Energy of Soil Organic Matter Decomposition in Different Qinghai-Tibet Plateau Grasslands

PubMed Central

Li, Jie; He, Nianpeng; Wei, Xuehong; Gao, Yang; Zuo, Yao

2015-01-01

Qinghai-Tibet Plateau grasslands are unique geographical regions and store substantial soil organic matter (SOM) in the soil surface, which make them very sensitive to global climate change. Here, we focused on three main grassland types (alpine meadow, steppe, and desert) and conducted a soil incubation experiment at five different temperatures (5, 10, 15, 20, and 25°C) to investigate SOM decomposition rates (R), temperature sensitivity (Q 10), and activation energy (E a). The results showed that grassland type and incubation temperature had significant impact on R (P < 0.001), and the values of R were exponential correlated with incubation temperature in three alpine grasslands. At the same temperature, R was in the following order: alpine meadow > alpinesteppe > alpine desert. The Q 10 values differed significantly among different grasslands, and the overall trends were as follows: alpine meadow (1.56 ± 0.09) < alpine steppe (1.88 ± 0.23) < alpine desert (2.39 ± 0.32). Moreover, the E a values differed significantly across different grassland types (P < 0.001) and increased with increasing incubation time. The exponential negative correlations between E a and R at 20°C across all grassland types (all Ps < 0.001) indicated that the substrate-quality temperature hypothesis is applicable to the alpine grasslands. Our findings provide new insights for understanding the responses of SOM decomposition and storage to warming scenarios in this Plateau. PMID:26176705

Single-layer graphene/titanium oxide cubic nanorods array/FTO heterojunction for sensitive ultraviolet light detection

NASA Astrophysics Data System (ADS)

Liang, Feng-Xia; Wang, Jiu-Zhen; Wang, Yi; Lin, Yi; Liang, Lin; Gao, Yang; Luo, Lin-Bao

2017-12-01

In this study, we report on the fabrication of a sensitive ultraviolet photodetector (UVPD) by simply transferring single-layer graphene (SLG) on rutile titanium oxide cubic nanorod (TiO2NRs) array. The cubic TiO2NRs array with strong light trapping effect was grown on fluorine-doped tin oxide (FTO) glass through a hydrothermal approach. The as-assembled UVPD was very sensitive to UV light illumination, but virtually blind to white light illumination. The responsivity and specific detectivity were estimated to be 52.1 A/W and 4.3 × 1012 Jones, respectively. What is more, in order to optimize device performance of UVPD, a wet-chemistry treatment was then employed to reduce the high concentration of defects in TiO2NRs during hydrothermal growth. It was found that the UVPD after treatment showed obvious decrease in sensitivity, but the response speed (rise time: 80 ms, fall time: 160 ms) and specific detectivity were substantially increased. It is also found that the speicific detectivity was imporoved by six-fold to 3.2 × 1013 Jones, which was the best result in comparison with previously reported TiO2 nanostructures or thin film based UVPDs. This totality of this study shows that the present SLG/TiO2NR/FTO UVPD may find potential application in future optoelectronic devices and systems.

Characterization of an intraluminal differential frequency-domain photoacoustics system

NASA Astrophysics Data System (ADS)

Lashkari, Bahman; Son, Jungik; Liang, Simon; Castelino, Robin; Foster, F. Stuart; Courtney, Brian; Mandelis, Andreas

2016-03-01

Cardiovascular related diseases are ranked as the second highest cause of death in Canada. Among the most important cardiovascular diseases is atherosclerosis. Current methods of diagnosis of atherosclerosis consist of angiography, intravascular ultrasound (IVUS) and optical coherence tomography (OCT). None of these methods possesses adequate sensitivity, as the ideal technique should be capable of both depth profiling, as well as functional imaging. An alternative technique is photoacoustics (PA) which can perform deep imaging and spectroscopy. The presented study explores the application of wavelength-modulated differential photoacoustic radar (WM-DPAR) for characterizing arterial vessels. The wavelength-modulated differential photoacoustic technique was shown to be able to substantially increase the dynamic range and sensitivity of hemoglobin oxygenation level detection. In this work the differential PA technique was used with a very high frequency modulation range. To perform spectroscopic PA imaging, at least two wavelengths are required. The selected wavelengths for this work are 1210 nm and 980 nm. 1210 nm corresponds to the maximum optical absorption coefficient of cholesterol and cholesteryl esters which are the main constituents of plaques. Since water, elastin and collagen also have high absorption coefficients at 1210 nm, this wavelength alone cannot provide very high sensitivity and specificity. The additional wavelength, 980 nm corresponds to high absorption coefficient of those constituents of healthy artery tissue. The simultaneous application of the abovementioned wavelengths can provide higher sensitivity and improved specificity in detecting lipids in the arterial vessels.

Highly sensitive and quantitative evaluation of the EGFR T790M mutation by nanofluidic digital PCR.

PubMed

Iwama, Eiji; Takayama, Koichi; Harada, Taishi; Okamoto, Isamu; Ookubo, Fumihiko; Kishimoto, Junji; Baba, Eishi; Oda, Yoshinao; Nakanishi, Yoichi

2015-08-21

The mutation of T790M in EGFR is a major mechanism of resistance to treatment with EGFR-TKIs. Only qualitative detection (presence or absence) of T790M has been described to date, however. Digital PCR (dPCR) analysis has recently been applied to the quantitative detection of target molecules in cancer with high sensitivity. In the present study, 25 tumor samples (13 obtained before and 12 after EGFR-TKI treatment) from 18 NSCLC patients with activating EGFR mutations were evaluated for T790M with dPCR. The ratio of the number of T790M alleles to that of activating mutation alleles (T/A) was determined. dPCR detected T790M in all 25 samples. Although T790M was present in all pre-TKI samples from 13 patients, 10 of these patients had a low T/A ratio and manifested substantial tumor shrinkage during treatment with EGFR-TKIs. In six of seven patients for whom both pre- and post-TKI samples were available, the T/A ratio increased markedly during EGFR-TKI treatment. Highly sensitive dPCR thus detected T790M in all NSCLC patients harboring activating EGFR mutations whether or not they had received EGFR-TKI treatment. Not only highly sensitive but also quantitative detection of T790M is important for evaluation of the contribution of T790M to EGFR-TKI resistance.

Transcript analysis in two alfalfa salt tolerance selected breeding populations relative to a non-tolerant population.

PubMed

Gruber, M Y; Xia, J; Yu, M; Steppuhn, H; Wall, K; Messer, D; Sharpe, A G; Acharya, S N; Wishart, D S; Johnson, D; Miller, D R; Taheri, A

2017-02-01

With the growing limitations on arable land, alfalfa (a widely cultivated, low-input forage) is now being selected to extend cultivation into saline lands for low-cost biofeedstock purposes. Here, minerals and transcriptome profiles were compared between two new salinity-tolerant North American alfalfa breeding populations and a more salinity-sensitive western Canadian alfalfa population grown under hydroponic saline conditions. All three populations accumulated two-fold higher sodium in roots than shoots as a function of increased electrical conductivity. At least 50% of differentially expressed genes (p < 0.05) were down-regulated in the salt-sensitive population growing under high salinity, while expression remained unchanged in the saline-tolerant populations. In particular, most reduction in transcript levels in the salt-sensitive population was observed in genes specifying cell wall structural components, lipids, secondary metabolism, auxin and ethylene hormones, development, transport, signalling, heat shock, proteolysis, pathogenesis-response, abiotic stress, RNA processing, and protein metabolism. Transcript diversity for transcription factors, protein modification, and protein degradation genes was also more strongly affected in salt-tolerant CW064027 than in salt-tolerant Bridgeview and salt-sensitive Rangelander, while both saline-tolerant populations showed more substantial up-regulation in redox-related genes and B-ZIP transcripts. The report highlights the first use of bulked genotypes as replicated samples to compare the transcriptomes of obligate out-cross breeding populations in alfalfa.

Initial locomotor sensitivity to cocaine varies widely among inbred mouse strains.

PubMed

Wiltshire, T; Ervin, R B; Duan, H; Bogue, M A; Zamboni, W C; Cook, S; Chung, W; Zou, F; Tarantino, L M

2015-03-01

Initial sensitivity to psychostimulants can predict subsequent use and abuse in humans. Acute locomotor activation in response to psychostimulants is commonly used as an animal model of initial drug sensitivity and has been shown to have a substantial genetic component. Identifying the specific genetic differences that lead to phenotypic differences in initial drug sensitivity can advance our understanding of the processes that lead to addiction. Phenotyping inbred mouse strain panels are frequently used as a first step for studying the genetic architecture of complex traits. We assessed locomotor activation following a single, acute 20 mg/kg dose of cocaine (COC) in males from 45 inbred mouse strains and observed significant phenotypic variation across strains indicating a substantial genetic component. We also measured levels of COC, the active metabolite, norcocaine and the major inactive metabolite, benzoylecgonine, in plasma and brain in the same set of inbred strains. Pharmacokinetic (PK) and behavioral data were significantly correlated, but at a level that indicates that PK alone does not account for the behavioral differences observed across strains. Phenotypic data from this reference population of inbred strains can be utilized in studies aimed at examining the role of psychostimulant-induced locomotor activation on drug reward and reinforcement and to test theories about addiction processes. Moreover, these data serve as a starting point for identifying genes that alter sensitivity to the locomotor stimulatory effects of COC. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Forest responses to increasing aridity and warmth in the southwestern United States.

PubMed

Williams, A Park; Allen, Craig D; Millar, Constance I; Swetnam, Thomas W; Michaelsen, Joel; Still, Christopher J; Leavitt, Steven W

2010-12-14

In recent decades, intense droughts, insect outbreaks, and wildfires have led to decreasing tree growth and increasing mortality in many temperate forests. We compared annual tree-ring width data from 1,097 populations in the coterminous United States to climate data and evaluated site-specific tree responses to climate variations throughout the 20th century. For each population, we developed a climate-driven growth equation by using climate records to predict annual ring widths. Forests within the southwestern United States appear particularly sensitive to drought and warmth. We input 21st century climate projections to the equations to predict growth responses. Our results suggest that if temperature and aridity rise as they are projected to, southwestern trees will experience substantially reduced growth during this century. As tree growth declines, mortality rates may increase at many sites. Increases in wildfires and bark-beetle outbreaks in the most recent decade are likely related to extreme drought and high temperatures during this period. Using satellite imagery and aerial survey data, we conservatively calculate that ≈ 2.7% of southwestern forest and woodland area experienced substantial mortality due to wildfires from 1984 to 2006, and ≈ 7.6% experienced mortality associated with bark beetles from 1997 to 2008. We estimate that up to ≈ 18% of southwestern forest area (excluding woodlands) experienced mortality due to bark beetles or wildfire during this period. Expected climatic changes will alter future forest productivity, disturbance regimes, and species ranges throughout the Southwest. Emerging knowledge of these impending transitions informs efforts to adaptively manage southwestern forests.

Forest responses to increasing aridity and warmth in the southwestern United States

USGS Publications Warehouse

Williams, A.P.; Allen, Craig D.; Millar, C.I.; Swetnam, T.W.; Michaelsen, J.; Still, C.J.; Leavitt, Steven W.

2010-01-01

In recent decades, intense droughts, insect outbreaks, and wildfires have led to decreasing tree growth and increasing mortality in many temperate forests. We compared annual tree-ring width data from 1,097 populations in the coterminous United States to climate data and evaluated site-specific tree responses to climate variations throughout the 20th century. For each population, we developed a climate-driven growth equation by using climate records to predict annual ring widths. Forests within the southwestern United States appear particularly sensitive to drought and warmth. We input 21st century climate projections to the equations to predict growth responses. Our results suggest that if temperature and aridity rise as they are projected to, southwestern trees will experience substantially reduced growth during this century. As tree growth declines, mortality rates may increase at many sites. Increases in wildfires and bark-beetle outbreaks in the most recent decade are likely related to extreme drought and high temperatures during this period. Using satellite imagery and aerial survey data, we conservatively calculate that ≈2.7% of southwestern forest and woodland area experienced substantial mortality due to wildfires from 1984 to 2006, and ≈7.6% experienced mortality associated with bark beetles from 1997 to 2008. We estimate that up to ≈18% of southwestern forest area (excluding woodlands) experienced mortality due to bark beetles or wildfire during this period. Expected climatic changes will alter future forest productivity, disturbance regimes, and species ranges throughout the Southwest. Emerging knowledge of these impending transitions informs efforts to adaptively manage southwestern forests.

Critical factors determining the variation in SOA yields from terpene ozonolysis: a combined experimental and computational study.

PubMed

Donahue, Neil M; Hartz, Kara E Huff; Chuong, Bao; Presto, Albert A; Stanier, Charles O; Rosenhørn, Thomas; Robinson, Allen L; Pandis, Spyros N

2005-01-01

A substantial fraction of the total ultrafine particulate mass is comprised of organic compounds. Of this fraction, a significant subfraction is secondary organic aerosol (SOA), meaning that the compounds are a by-product of chemistry in the atmosphere. However, our understanding of the kinetics and mechanisms leading to and following SOA formation is in its infancy. We lack a clear description of critical phenomena; we often don't know the key, rate limiting steps in SOA formation mechanisms. We know almost nothing about aerosol yields past the first generation of oxidation products. Most importantly, we know very little about the derivatives in these mechanisms; we do not understand how changing conditions, be they precursor levels, oxidant concentrations, co-reagent concentrations (i.e., the VOC/NOx ratio) or temperature will influence the yields of SOA. In this paper we explore the connections between fundamental details of physical chemistry and the multitude of steps associated with SOA formation, including the initial gas-phase reaction mechanisms leading to condensible products, the phase partitioning itself, and the continued oxidation of the condensed-phase organic products. We show that SOA yields in the alpha-pinene + ozone are highly sensitive to NOx, and that SOA yields from beta-caryophylene + ozone appear to increase with continued ozone exposure, even as aerosol hygroscopicity increases as well. We suggest that SOA yields are likely to increase substantially through several generations of oxidative processing of the semi-volatile products.

Assessing Impacts of Disturbances and Climate Change on Carbon Stocks in Mexican Semidry Forests of the Yucatan Peninsula

NASA Astrophysics Data System (ADS)

Dai, Z.; Birdsey, R.; Johnson, K.; Dupuy, J. M.; Hernandez-Stefanoni, J. L.; Richardson, K.

2014-12-01

The spatially explicit biogeochemical model Forest-DNDC was used to estimate carbon dynamics with disturbances and climate change in secondary semidry forests in Yucatan Peninsula. The model was validated using observations from 276 field plots in a 350 km2 region of semi-deciduous forest surrounding the intensive monitoring site at Kaxil Kiuic, and it performed well with high performance efficiency (E=0.79, R2=0.83). The simulation results showed substantial spatial differences in biomass in the forests due to historical disturbance patterns and heterogeneous forest environments. The simulated impacts of the disturbances that occurred from 1998-2010 revealed an estimated loss of total biomass carbon storage of 154.7 Gg due mainly to about 12 km2 of forestland loss. The results from disturbance scenarios indicate that disastrous storms, which are not uncommon in the Yucatan Peninsula, can substantially impact carbon storage in a short time. However, warming can produce a long-term impact on carbon sequestration, due principally to the decrease in biomass carbon at a mean rate of over 100 kg ha-1yr-1 with an increase in temperature by 1 degree Celsius. The forests in this area are highly sensitive to warming due to a semidry climate where the evapotranspiration is higher than precipitation. Even if each degree of warming increase is accompanied by an increase in precipitation of 10%, the significant impact of warming cannot be dismissed.

Sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants.

PubMed

Gerner, Nadine V; Cailleaud, Kevin; Bassères, Anne; Liess, Matthias; Beketov, Mikhail A

2017-11-01

Hydrocarbons have an utmost economical importance but may also cause substantial ecological impacts due to accidents or inadequate transportation and use. Currently, freshwater biomonitoring methods lack an indicator that can unequivocally reflect the impacts caused by hydrocarbons while being independent from effects of other stressors. The aim of the present study was to develop a sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants, which can be used in hydrocarbon-specific bioindicators. We employed the Relative Sensitivity method and developed the sensitivity ranking S hydrocarbons based on literature ecotoxicological data supplemented with rapid and mesocosm test results. A first validation of the sensitivity ranking based on an earlier field study has been conducted and revealed the S hydrocarbons ranking to be promising for application in sensitivity based indicators. Thus, the first results indicate that the ranking can serve as the core component of future hydrocarbon-specific and sensitivity trait based bioindicators.

Variational Methods in Design Optimization and Sensitivity Analysis for Two-Dimensional Euler Equations

NASA Technical Reports Server (NTRS)

Ibrahim, A. H.; Tiwari, S. N.; Smith, R. E.

1997-01-01

Variational methods (VM) sensitivity analysis employed to derive the costate (adjoint) equations, the transversality conditions, and the functional sensitivity derivatives. In the derivation of the sensitivity equations, the variational methods use the generalized calculus of variations, in which the variable boundary is considered as the design function. The converged solution of the state equations together with the converged solution of the costate equations are integrated along the domain boundary to uniquely determine the functional sensitivity derivatives with respect to the design function. The application of the variational methods to aerodynamic shape optimization problems is demonstrated for internal flow problems at supersonic Mach number range. The study shows, that while maintaining the accuracy of the functional sensitivity derivatives within the reasonable range for engineering prediction purposes, the variational methods show a substantial gain in computational efficiency, i.e., computer time and memory, when compared with the finite difference sensitivity analysis.

Knock-in mice harboring a Ca(2+) desensitizing mutation in cardiac troponin C develop early onset dilated cardiomyopathy.

PubMed

McConnell, Bradley K; Singh, Sonal; Fan, Qiying; Hernandez, Adriana; Portillo, Jesus P; Reiser, Peter J; Tikunova, Svetlana B

2015-01-01

The physiological consequences of aberrant Ca(2+) binding and exchange with cardiac myofilaments are not clearly understood. In order to examine the effect of decreasing Ca(2+) sensitivity of cTnC on cardiac function, we generated knock-in mice carrying a D73N mutation (not known to be associated with heart disease in human patients) in cTnC. The D73N mutation was engineered into the regulatory N-domain of cTnC in order to reduce Ca(2+) sensitivity of reconstituted thin filaments by increasing the rate of Ca(2+) dissociation. In addition, the D73N mutation drastically blunted the extent of Ca(2+) desensitization of reconstituted thin filaments induced by cTnI pseudo-phosphorylation. Compared to wild-type mice, heterozygous knock-in mice carrying the D73N mutation exhibited a substantially decreased Ca(2+) sensitivity of force development in skinned ventricular trabeculae. Kaplan-Meier survival analysis revealed that median survival time for knock-in mice was 12 weeks. Echocardiographic analysis revealed that knock-in mice exhibited increased left ventricular dimensions with thinner walls. Echocardiographic analysis also revealed that measures of systolic function, such as ejection fraction (EF) and fractional shortening (FS), were dramatically reduced in knock-in mice. In addition, knock-in mice displayed electrophysiological abnormalities, namely prolonged QRS and QT intervals. Furthermore, ventricular myocytes isolated from knock-in mice did not respond to β-adrenergic stimulation. Thus, knock-in mice developed pathological features similar to those observed in human patients with dilated cardiomyopathy (DCM). In conclusion, our results suggest that decreasing Ca(2+) sensitivity of the regulatory N-domain of cTnC is sufficient to trigger the development of DCM.

Application of design sensitivity analysis for greater improvement on machine structural dynamics

NASA Technical Reports Server (NTRS)

Yoshimura, Masataka

1987-01-01

Methodologies are presented for greatly improving machine structural dynamics by using design sensitivity analyses and evaluative parameters. First, design sensitivity coefficients and evaluative parameters of structural dynamics are described. Next, the relations between the design sensitivity coefficients and the evaluative parameters are clarified. Then, design improvement procedures of structural dynamics are proposed for the following three cases: (1) addition of elastic structural members, (2) addition of mass elements, and (3) substantial charges of joint design variables. Cases (1) and (2) correspond to the changes of the initial framework or configuration, and (3) corresponds to the alteration of poor initial design variables. Finally, numerical examples are given for demonstrating the availability of the methods proposed.

Impact of and correction for instrument sensitivity drift on nanoparticle size measurements by single-particle ICP-MS

PubMed Central

El Hadri, Hind; Petersen, Elijah J.; Winchester, Michael R.

2016-01-01

The effect of ICP-MS instrument sensitivity drift on the accuracy of NP size measurements using single particle (sp)ICP-MS is investigated. Theoretical modeling and experimental measurements of the impact of instrument sensitivity drift are in agreement and indicate that drift can impact the measured size of spherical NPs by up to 25 %. Given this substantial bias in the measured size, a method was developed using an internal standard to correct for the impact of drift and was shown to accurately correct for a decrease in instrument sensitivity of up to 50 % for 30 nm and 60 nm gold nanoparticles. PMID:26894759

The influence of landing mat composition on ankle injury risk during a gymnastic landing: a biomechanical quantification.

PubMed

Xiao, Xiaofei; Hao, Weiya; Li, Xuhong; Wan, Bingjun; Shan, Gongbing

2017-01-01

About 70% injury of gymnasts happened during landing - an interaction between gymnast and landing mat. The most injured joint is the ankle. The current study examined the effect of mechanical properties of landing mat on ankle loading with aims to identify means of decreasing the risk of ankle injury. Gymnastic skill - salto backward stretched with 3/2 twist was captured by two high-speed camcorders and digitized by using SIMI-Motion software. A subject-specific, 14-segment rigid-body model and a mechanical landing-mat model were built using BRG.LifeMODTM. The landings were simulated with varied landing-mat mechanical properties (i.e., stiffness, dampness and friction coefficients). Real landing performance could be accurately reproduced by the model. The simulations revealed that the ankle angle was relatively sensitive to stiffness and dampness of the landing mat, the ankle loading rate increased 26% when the stiffness was increased by 30%, and the changing of dampness had notable effect on horizontal ground reaction force and foot velocity. Further, the peak joint-reaction force and joint torque were more sensitive to friction than to stiffness and dampness of landing mat. Finally, ankle muscles would dissipate about twice energy (189%) when the friction was increased by 30%. Loads to ankles during landing would increase as the stiffness and dampness of the landing mat increase. Yet, increasing friction would cause a substantial rise of the ankle internal loads. As such, the friction should be a key factor influencing the risk of injury. Unfortunately, this key factor has rarely attracted attention in practice.

Gas magnetometer

DOEpatents

Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert

2016-05-03

Measurement of a precessional rate of a gas, such as an alkali gas, in a magnetic field is made by promoting a non-uniform precession of the gas in which substantially no net magnetic field affects the gas during a majority of the precession cycle. This allows sensitive gases that would be subject to spin-exchange collision de-phasing to be effectively used for extremely sensitive measurements in the presence of an environmental magnetic field such as the Earth's magnetic field.

Sensitivity of a model projection of near-surface permafrost degradation to soil column depth and representation of soil organic matter.

Treesearch

David M. Lawrence; Andrew G. Slater; Vladimir E. Romanovsky; Dmitry J. Nicolsky

2008-01-01

The sensitivity of a global land-surface model projection of near-surface permafrost degradation is assessed with respect to explicit accounting of the thermal and hydrologic properties of soil organic matter and to a deepening of the soil column from 3.5 to 50 or more m. Together these modifications result in substantial improvements in the simulation of near-surface...

Future Fuels

DTIC Science & Technology

2006-04-01

relevant to TWV is focused on permanent magnet motors , often wheel mounted. Wound rotor motors provide substantially different design and control...options than permanent magnet motors , at the expense of additional cooling requirements. Their benefits include higher peak torque and less sensitivity

Reproductive Toxicology: From Science to Public Policy

EPA Science Inventory

Male reproductive toxicology research substantially influences policies that protect men's health. US policy directs regulatory agencies to ensure environmental protection for vulnerable groups, including boys and men where factors like age- and sex-specific sensitivities are app...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Namikawa, Toshiya

We present here a new method for delensing B modes of the cosmic microwave background (CMB) using a lensing potential reconstructed from the same realization of the CMB polarization (CMB internal delensing). The B -mode delensing is required to improve sensitivity to primary B modes generated by, e.g., the inflationary gravitational waves, axionlike particles, modified gravity, primordial magnetic fields, and topological defects such as cosmic strings. However, the CMB internal delensing suffers from substantial biases due to correlations between observed CMB maps to be delensed and that used for reconstructing a lensing potential. Since the bias depends on realizations, wemore » construct a realization-dependent (RD) estimator for correcting these biases by deriving a general optimal estimator for higher-order correlations. The RD method is less sensitive to simulation uncertainties. Compared to the previous ℓ -splitting method, we find that the RD method corrects the biases without substantial degradation of the delensing efficiency.« less

Hijacking membrane transporters for arsenic phytoextraction

PubMed Central

LeBlanc, Melissa S.; McKinney, Elizabeth C.; Meagher, Richard B.; Smith, Aaron P.

2012-01-01

Arsenic is a toxic metalloid and recognized carcinogen. Arsenate and arsenite are the most common arsenic species available for uptake by plants. As an inorganic phosphate (Pi) analog, arsenate is acquired by plant roots through endogenous Pi transport systems. Inside the cell, arsenate is reduced to the thiol-reactive form arsenite. Glutathione (GSH)-conjugates of arsenite may be extruded from the cell or sequestered in vacuoles by members of the ATP-binding cassette (ABC) family of transporters. In the present study we sought to enhance both plant arsenic uptake through Pi transporter overexpression, and plant arsenic tolerance through ABC transporter overexpression. We demonstrate that Arabidopsis thaliana plants overexpressing the high-affinity Pi transporter family members, AtPht1;1 or AtPht1;7, are hypersensitive to arsenate due to increased arsenate uptake. These plants do not exhibit increased sensitivity to arsenite. Co-overexpression of the yeast ABC transporter YCF1 in combination with AtPht1;1 or AtPht1;7 suppresses the arsenate-sensitive phenotype while further enhancing arsenic uptake. Taken together, our results support an arsenic transport mechanism in which arsenate uptake is increased through Pi transporter overexpression, and arsenic tolerance is enhanced through YCF1-mediated vacuolar sequestration. This work substantiates the viability of coupling enhanced uptake and vacuolar sequestration as a means for developing a prototypical engineered arsenic hyperaccumulator. PMID:23108027

UHF and VHF radar observations of thunderstorms

NASA Technical Reports Server (NTRS)

Holden, D. N.; Ulbrich, C. W.; Larsen, M. F.; Rottger, J.; Ierkic, H. M.; Swartz, W.

1986-01-01

A study of thunderstorms was made in the Summer of 1985 with the 430-MHz and 50-MHz radars at the Arecibo Observatory in Puerto Rico. Both radars use the 300-meter dish, which gives a beam width of less than 2 degrees even at these long wavelengths. Though the radars are steerable, only vertical beams were used in this experiment. The height resolution was 300 and 150 meters for the UHF and VHF, respectively. Lightning echoes, as well as returns from precipitation and clear-air turbulence were detected with both wavelengths. Large increases in the returned power were found to be coincident with increasing downward vertical velocities at UHF, whereas at VHF the total power returned was relatively constant during the life of a storm. This was attributed to the fact that the VHF is more sensitive to scattering from the turbulence-induced inhomogeneities in the refractive index and less sensitive to scatter from precipitation particles. On occasion, the shape of the Doppler spectra was observed to change with the occurrence of a lightning discharge in the pulse volume. Though the total power and mean reflectivity weighted Doppler velocity changed little during these events, the power is Doppler frequency bins near that corresponding to the updraft did increase substantially within a fraction of a second after a discharge was detected in the beam. This suggests some interaction between precipitation and lightning.

Effects of Warming on CO2 Fluxes in an Alpine Meadow Ecosystem on the Central Qinghai-Tibetan Plateau.

PubMed

Ganjurjav, Hasbagan; Gao, Qingzhu; Zhang, Weina; Liang, Yan; Li, Yawei; Cao, Xujuan; Wan, Yunfan; Li, Yue; Danjiu, Luobu

2015-01-01

To analyze CO2 fluxes under conditions of climate change in an alpine meadow on the central Qinghai-Tibetan Plateau, we simulated the effect of warming using open top chambers (OTCs) from 2012 to 2014. The OTCs increased soil temperature by 1.62°C (P < 0.05), but decreased soil moisture (1.38%, P < 0.05) during the experiments. The response of ecosystem CO2 fluxes to warming was variable, and dependent on the year. Under conditions of warming, mean gross ecosystem productivity (GEP) during the growing season increased significantly in 2012 and 2014 (P < 0.05); however, ecosystem respiration (ER) increased substantially only in 2012 (P < 0.05). The net ecosystem CO2 exchange (NEE) increased marginally in 2012 (P = 0.056), did not change in 2013(P > 0.05), and increased significantly in 2014 (P = 0.034) under conditions of warming. The GEP was more sensitive to climate variations than was the ER, resulting in a large increase in net carbon uptake under warming in the alpine meadow. Under warming, the 3-year averages of GEP, ER, and NEE increased by 19.6%, 15.1%, and 21.1%, respectively. The seasonal dynamic patterns of GEP and NEE, but not ER, were significantly impacted by warming. Aboveground biomass, particularly the graminoid biomass increased significantly under conditions of warming. Soil moisture, soil temperature, and aboveground biomass were the main factors that affected the variation of the ecosystem CO2 fluxes. The effect of warming on inter- and intra-annual patterns of ecosystem CO2 fluxes and the mechanism of different sensitivities in GEP and ER to warming, require further researched.

Effects of Warming on CO2 Fluxes in an Alpine Meadow Ecosystem on the Central Qinghai–Tibetan Plateau

PubMed Central

Ganjurjav, Hasbagan; Gao, Qingzhu; Zhang, Weina; Liang, Yan; Li, Yawei; Cao, Xujuan; Wan, Yunfan; Li, Yue; Danjiu, Luobu

2015-01-01

To analyze CO2 fluxes under conditions of climate change in an alpine meadow on the central Qinghai–Tibetan Plateau, we simulated the effect of warming using open top chambers (OTCs) from 2012 to 2014. The OTCs increased soil temperature by 1.62°C (P < 0.05), but decreased soil moisture (1.38%, P < 0.05) during the experiments. The response of ecosystem CO2 fluxes to warming was variable, and dependent on the year. Under conditions of warming, mean gross ecosystem productivity (GEP) during the growing season increased significantly in 2012 and 2014 (P < 0.05); however, ecosystem respiration (ER) increased substantially only in 2012 (P < 0.05). The net ecosystem CO2 exchange (NEE) increased marginally in 2012 (P = 0.056), did not change in 2013(P > 0.05), and increased significantly in 2014 (P = 0.034) under conditions of warming. The GEP was more sensitive to climate variations than was the ER, resulting in a large increase in net carbon uptake under warming in the alpine meadow. Under warming, the 3-year averages of GEP, ER, and NEE increased by 19.6%, 15.1%, and 21.1%, respectively. The seasonal dynamic patterns of GEP and NEE, but not ER, were significantly impacted by warming. Aboveground biomass, particularly the graminoid biomass increased significantly under conditions of warming. Soil moisture, soil temperature, and aboveground biomass were the main factors that affected the variation of the ecosystem CO2 fluxes. The effect of warming on inter- and intra-annual patterns of ecosystem CO2 fluxes and the mechanism of different sensitivities in GEP and ER to warming, require further researched. PMID:26147223

A global analysis of traits predicting species sensitivity to habitat fragmentation

USGS Publications Warehouse

Keinath, Douglas; Doak, Daniel F.; Hodges, Karen E.; Prugh, Laura R.; Fagan, William F.; Sekercioglu, Cagan H.; Buchart, Stuart H. M.; Kauffman, Matthew J.

2017-01-01

AimElucidating patterns in species responses to habitat fragmentation is an important focus of ecology and conservation, but studies are often geographically restricted, taxonomically narrow or use indirect measures of species vulnerability. We investigated predictors of species presence after fragmentation using data from studies around the world that included all four terrestrial vertebrate classes, thus allowing direct inter-taxonomic comparison.LocationWorld-wide.MethodsWe used generalized linear mixed-effect models in an information theoretic framework to assess the factors that explained species presence in remnant habitat patches (3342 patches; 1559 species, mostly birds; and 65,695 records of patch-specific presence–absence). We developed a novel metric of fragmentation sensitivity, defined as the maximum rate of change in probability of presence with changing patch size (‘Peak Change’), to distinguish between general rarity on the landscape and sensitivity to fragmentation per se.ResultsSize of remnant habitat patches was the most important driver of species presence. Across all classes, habitat specialists, carnivores and larger species had a lower probability of presence, and those effects were substantially modified by interactions. Sensitivity to fragmentation (measured by Peak Change) was influenced primarily by habitat type and specialization, but also by fecundity, life span and body mass. Reptiles were more sensitive than other classes. Grassland species had a lower probability of presence, though sample size was relatively small, but forest and shrubland species were more sensitive.Main conclusionsHabitat relationships were more important than life-history characteristics in predicting the effects of fragmentation. Habitat specialization increased sensitivity to fragmentation and interacted with class and habitat type; forest specialists and habitat-specific reptiles were particularly sensitive to fragmentation. Our results suggest that when conservationists are faced with disturbances that could fragment habitat they should pay particular attention to specialists, particularly reptiles. Further, our results highlight that the probability of presence in fragmented landscapes and true sensitivity to fragmentation are predicted by different factors.

Ultra-long high-sensitivity Φ-OTDR for high spatial resolution intrusion detection of pipelines.

PubMed

Peng, Fei; Wu, Han; Jia, Xin-Hong; Rao, Yun-Jiang; Wang, Zi-Nan; Peng, Zheng-Pu

2014-06-02

An ultra-long phase-sensitive optical time domain reflectometry (Φ-OTDR) that can achieve high-sensitivity intrusion detection over 131.5km fiber with high spatial resolution of 8m is presented, which is the longest Φ-OTDR reported to date, to the best of our knowledge. It is found that the combination of distributed Raman amplification with heterodyne detection can extend the sensing distance and enhances the sensitivity substantially, leading to the realization of ultra-long Φ-OTDR with high sensitivity and spatial resolution. Furthermore, the feasibility of applying such an ultra-long Φ-OTDR to pipeline security monitoring is demonstrated and the features of intrusion signal can be extracted with improved SNR by using the wavelet detrending/denoising method proposed.

Temporal Variability of North Atlantic Carbon Fluxes and their Sensitivity to the Meridional Overturning Circulation

NASA Astrophysics Data System (ADS)

Brown, P.; McDonagh, E.; Sanders, R.; King, B.; Watson, A. J.; Schuster, U.; Henson, S.

2016-02-01

The North Atlantic plays a critical role in the global carbon cycle both as a region of substantial air-sea carbon dioxide uptake and as a location for the transfer of CO2 to depth on climatically-important timescales. While the magnitude of surface fluxes is relatively well constrained, our understanding of the processes that drive variability in ocean-atmosphere exchange and subsequent subsurface carbon accumulation is not as well defined. Here we present observation-derived high-resolution estimates of short-term 10-day meridional ocean carbon transport variability across the subtropical North Atlantic for 2004-2012. Substantial seasonal, sub-annual and interannual transport variability is observed that is highly sensitive to the strength of the Atlantic Meridional Overturning Circulation. While the recently identified multi-year decrease in AMOC strength similarly impacts carbon transports, its full effect is masked by the northwards transport of increasing surface CO2 levels. A 30% slowdown in the meridional circulation in 2009-2010 and the anomalous effects it had on the transport, storage and divergence of heat and freshwater in the subtropical and subpolar gyres and local wind regimes are investigated for their impact on local air-sea CO2 fluxes. Temperature and salt content anomalies identified in each gyre are found to drive (subtropics) or hinder (subpolar) additional carbon uptake from the atmosphere by affecting the physical solubility pump for CO2. Additionally their simultaneous effect on mixed layer depth and the vertical supply of nutrients to the surface is shown to magnify the CO2 flux observed by driving anomalous primary production rates.

Worldwide variability in growth and its association with health: Incorporating body composition, developmental plasticity, and intergenerational effects.

PubMed

Wells, Jonathan C K

2017-03-01

In their seminal book "Worldwide variation in human growth," published in 1976, Eveleth and Tanner highlighted substantial variability within and between populations in the magnitude and schedule of human growth. In the four decades since then, research has clarified why growth variability is so closely associated with human health. First, growth patterns are strongly associated with body composition, both in the short- and long-term. Poor growth in early life constrains the acquisition of lean tissue, while compensatory "catch-up" growth may elevate body fatness. Second, these data are examples of the fundamental link between growth and developmental plasticity. Growth is highly sensitive to ecological stresses and stimuli during early "critical windows," but loses much of this sensitivity as it undergoes canalization during early childhood. Crucially, the primary source of stimuli during early "critical windows" is not the external environment itself, but rather maternal phenotype, which transduces the impact of ecological conditions. Maternal phenotype, representing many dimensions of "capital," thus generates a powerful impact on the developmental trajectory of the offspring. There is increasing evidence that low levels of maternal capital impact the offspring's size at birth, schedule of maturation, and body composition and physiological function in adulthood. While evidence has accrued of substantial heritability in adult height, it is clear that the pathway through which it is attained has major implications for metabolic phenotype. Integrating these perspectives is important for understanding how developmental plasticity may on the one hand contribute to adaptation, while on the other shape susceptibility to non-communicable disease. © 2017 Wiley Periodicals, Inc.

Mu-Opioid (MOP) receptor mediated G-protein signaling is impaired in specific brain regions in a rat model of schizophrenia.

PubMed

Szűcs, Edina; Büki, Alexandra; Kékesi, Gabriella; Horváth, Gyöngyi; Benyhe, Sándor

2016-04-21

Schizophrenia is a complex mental health disorder. Clinical reports suggest that many patients with schizophrenia are less sensitive to pain than other individuals. Animal models do not interpret schizophrenia completely, but they can model a number of symptoms of the disease, including decreased pain sensitivities and increased pain thresholds of various modalities. Opioid receptors and endogenous opioid peptides have a substantial role in analgesia. In this biochemical study we investigated changes in the signaling properties of the mu-opioid (MOP) receptor in different brain regions, which are involved in the pain transmission, i.e., thalamus, olfactory bulb, prefrontal cortex and hippocampus. Our goal was to compare the transmembrane signaling mediated by MOP receptors in control rats and in a recently developed rat model of schizophrenia. Regulatory G-protein activation via MOP receptors were measured in [(35)S]GTPγS binding assays in the presence of a highly selective MOP receptor peptide agonist, DAMGO. It was found that the MOP receptor mediated activation of G-proteins was substantially lower in membranes prepared from the 'schizophrenic' model rats than in control animals. The potency of DAMGO to activate MOP receptor was also decreased in all brain regions studied. Taken together in our rat model of schizophrenia, MOP receptor mediated G-proteins have a reduced stimulatory activity compared to membrane preparations taken from control animals. The observed distinct changes of opioid receptor functions in different areas of the brain do not explain the augmented nociceptive threshold described in these animals. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Trends in survival and early functional outcomes from hospitalized severe adult traumatic brain injuries, Pennsylvania, 1998–2007

PubMed Central

Sánchez, Álvaro I; Krafty, Robert T; Weiss, Harold B; Rubiano, Andrés M; Peitzman, Andrew B; Puyana, Juan Carlos

2011-01-01

Objective To determine trends for in-hospital survival and functional outcomes at acute care hospital discharge for severe adult traumatic brain injury (SATBI) patients in Pennsylvania, during 1998–2007. Methods Secondary analysis of the Pennsylvania trauma outcome study database. Main Outcome Measures Survival and functional status scores of five domains (feeding, locomotion, expression, transfer mobility, and social interaction) fitted into logistic regression models adjusted for age, sex, race, co-morbidities, injury mechanism, extra-cranial injuries, severity scores, hospital stay, trauma center, and hospital level. Sensitivity analyses for functional outcomes were performed. Results There were 26,234 SATBI patients. Annual numbers of SATBI increased from 1,757 to 3,808 during 1998–2007. Falls accounted for 47.7% of all SATBI. Survival increased significantly from 72.5% to 82.7% (OR 1.10, 95%CI 1.08–1.11, P<0.001). In sensitivity analyses, trends of complete independence in functional outcomes increased significantly for expression (OR 1.01, 95%CI 1.00–1.02, P=0.011) and social interaction (OR 1.01, 95%CI 1.00–1.03, P=0.002). There were no significant variations over time for feeding, locomotion, and transfer mobility. Conclusions Trends for SATBI served by Pennsylvania’s established trauma system showed increases in rates but substantial reductions in mortality and significant improvements in functional outcomes at discharge for expression and social interaction. PMID:21386713

Loss of ecosystem productivity with repeated drought: a multi-year experiment to assess the role of drought legacy effects

NASA Astrophysics Data System (ADS)

Smith, M. D.; Knapp, A.; Hoover, D. L.; Avolio, M. L.; Felton, A. J.; Slette, I.; Wilcox, K.

2017-12-01

Climate extremes, such as drought, are increasing in frequency and intensity, and the ecological consequences of these extreme events can be substantial and widespread. Yet, little is known about the factors that determine recovery of ecosystem function post-drought. Such knowledge is particularly important because post-drought recovery periods can be protracted depending on drought legacy effects (e.g., loss key plant populations, altered community structure and/or biogeochemical processes). These drought legacies may alter ecosystem function for many years post-drought and may impact future sensitivity to climate extremes. With forecasts of more frequent drought, there is an imperative to understand whether and how post-drought legacies will affect ecosystem response to future drought events. To address this knowledge gap, we experimentally imposed over an eight year period two extreme growing season droughts, each two years in duration followed by a two-year recovery period, in a central US grassland. We found that aboveground net primary productivity (ANPP) declined dramatically with the first drought and was accompanied by a large shift in plant species composition (loss of C3 forb and increase in C4 grasses). This drought legacy - shift in plant composition - persisted two years post-drought. Yet, despite this legacy, ANPP recovered fully. However, we expected that previously-droughted grassland would be less sensitive to a second extreme drought due to the shift in plant composition. Contrary to this expectation, previously droughted grassland experienced a greater loss in ANPP than grassland that had not experienced drought. Furthermore, previously droughted grassland did not fully recover after the second drought. Thus, the legacy of drought - a shift in plant community composition - increased ecosystem sensitivity to a future extreme drought event.

Substantial advantage of a combined Bayesian and genotyping approach in testosterone doping tests.

PubMed

Schulze, Jenny Jakobsson; Lundmark, Jonas; Garle, Mats; Ekström, Lena; Sottas, Pierre-Edouard; Rane, Anders

2009-03-01

Testosterone abuse is conventionally assessed by the urinary testosterone/epitestosterone (T/E) ratio, levels above 4.0 being considered suspicious. A deletion polymorphism in the gene coding for UGT2B17 is strongly associated with reduced testosterone glucuronide (TG) levels in urine. Many of the individuals devoid of the gene would not reach a T/E ratio of 4.0 after testosterone intake. Future test programs will most likely shift from population based- to individual-based T/E cut-off ratios using Bayesian inference. A longitudinal analysis is dependent on an individual's true negative baseline T/E ratio. The aim was to investigate whether it is possible to increase the sensitivity and specificity of the T/E test by addition of UGT2B17 genotype information in a Bayesian framework. A single intramuscular dose of 500mg testosterone enanthate was given to 55 healthy male volunteers with either two, one or no allele (ins/ins, ins/del or del/del) of the UGT2B17 gene. Urinary excretion of TG and the T/E ratio was measured during 15 days. The Bayesian analysis was conducted to calculate the individual T/E cut-off ratio. When adding the genotype information, the program returned lower individual cut-off ratios in all del/del subjects increasing the sensitivity of the test considerably. It will be difficult, if not impossible, to discriminate between a true negative baseline T/E value and a false negative one without knowledge of the UGT2B17 genotype. UGT2B17 genotype information is crucial, both to decide which initial cut-off ratio to use for an individual, and for increasing the sensitivity of the Bayesian analysis.

Doping test results dependent on genotype of uridine diphospho-glucuronosyl transferase 2B17, the major enzyme for testosterone glucuronidation.

PubMed

Schulze, Jenny Jakobsson; Lundmark, Jonas; Garle, Mats; Skilving, Ilona; Ekström, Lena; Rane, Anders

2008-07-01

Testosterone abuse is conventionally assessed by the urinary testosterone/epitestosterone (T/E) ratio, levels above 4.0 being considered suspicious. The large variation in testosterone glucuronide (TG) excretion and its strong association with a deletion polymorphism in the uridine diphospho-glucuronosyl transferase (UGT) 2B17 gene challenge the accuracy of the T/E ratio test. Our objective was to investigate whether genotype-based cutoff values will improve the sensitivity and specificity of the test. This was an open three-armed comparative study. A total of 55 healthy male volunteers with either two, one, or no allele [insertion/insertion, insertion/deletion, or deletion/deletion (del/del)] of the UGT2B17 gene was included in the study. A single im dose of 500 mg testosterone enanthate was administered. Urinary excretion of TG after dose and the T/E ratio during 15 d were calculated. The degree and rate of increase in the TG excretion rate were highly dependent on the UGT2B17 genotype with a 20-fold higher average maximum increase in the insertion/insertion group compared with the del/del group. Of the del/del subjects, 40% never reached the T/E ratio of 4.0 on any of the 15 d after the dose. When differentiated cutoff levels for the del/del (1.0) and the other genotypes (6.0) were applied, the sensitivity increased substantially for the del/del group, and false positives in the other genotypes were eliminated. Consideration of the genetic variation in disposition of androgens will improve the sensitivity and specificity of the testosterone doping test. This is of interest not only for combating androgen doping in sports, but also for detecting and preventing androgen abuse in society.

Chronic stress sensitizes rats to pancreatitis induced by cerulein: Role of TNF-α

PubMed Central

Binker, Marcelo G; Binker-Cosen, Andres A; Richards, Daniel; Gaisano, Herbert Y; de Cosen, Rodica H; Cosen-Binker, Laura I

2010-01-01

AIM: To investigate chronic stress as a susceptibility factor for developing pancreatitis, as well as tumor necrosis factor-α (TNF-α) as a putative sensitizer. METHODS: Rat pancreatic acini were used to analyze the influence of TNF-α on submaximal (50 pmol/L) cholecystokinin (CCK) stimulation. Chronic restraint (4 h every day for 21 d) was used to evaluate the effects of submaximal (0.2 μg/kg per hour) cerulein stimulation on chronically stressed rats. RESULTS: In vitro exposure of pancreatic acini to TNF-α disorganized the actin cytoskeleton. This was further increased by TNF-α/CCK treatment, which additionally reduced amylase secretion, and increased trypsin and nuclear factor-κB activities in a protein-kinase-C δ and ε-dependent manner. TNF-α/CCK also enhanced caspases’ activity and lactate dehydrogenase release, induced ATP loss, and augmented the ADP/ATP ratio. In vivo, rats under chronic restraint exhibited elevated serum and pancreatic TNF-α levels. Serum, pancreatic, and lung inflammatory parameters, as well as caspases’activity in pancreatic and lung tissue, were substantially enhanced in stressed/cerulein-treated rats, which also experienced tissues’ ATP loss and greater ADP/ATP ratios. Histological examination revealed that stressed/cerulein-treated animals developed abundant pancreatic and lung edema, hemorrhage and leukocyte infiltrate, and pancreatic necrosis. Pancreatitis severity was greatly decreased by treating animals with an anti-TNF-α-antibody, which diminished all inflammatory parameters, histopathological scores, and apoptotic/necrotic markers in stressed/cerulein-treated rats. CONCLUSION: In rats, chronic stress increases susceptibility for developing pancreatitis, which involves TNF-α sensitization of pancreatic acinar cells to undergo injury by physiological cerulein stimulation. PMID:21105189

Effects of railway track design on the expected degradation: Parametric study on energy dissipation

NASA Astrophysics Data System (ADS)

Sadri, Mehran; Steenbergen, Michaël

2018-04-01

This paper studies the effect of railway track design parameters on the expected long-term degradation of track geometry. The study assumes a geometrically perfect and straight track along with spatial invariability, except for the presence of discrete sleepers. A frequency-domain two-layer model is used of a discretely supported rail coupled with a moving unsprung mass. The susceptibility of the track to degradation is objectively quantified by calculating the mechanical energy dissipated in the substructure under a moving train axle for variations of different track parameters. Results show that, apart from the operational train speed, the ballast/substructure stiffness is the most significant parameter influencing energy dissipation. Generally, the degradation increases with the train speed and with softer substructures. However, stiff subgrades appear more sensitive to particular train velocities, in a regime which is mostly relevant for conventional trains (100-200 km/h) and less for high-speed operation, where a stiff subgrade is always favorable and can reduce the sensitivity to degradation substantially, with roughly a factor up to 7. Also railpad stiffness, sleeper distance and rail cross-sectional properties are found to have considerable effect, with higher expected degradation rates for increasing railpad stiffness, increasing sleeper distance and decreasing rail profile bending stiffness. Unsprung vehicle mass and sleeper mass have no significant influence, however, only against the background of the assumption of an idealized (invariant and straight) track. Apart from dissipated mechanical energy, the suitability of the dynamic track stiffness is explored as an engineering parameter to assess the sensitivity to degradation. It is found that this quantity is inappropriate to assess the design of an idealized track.

Contrasting responses of photosynthesis to salt stress in the glycophyte Arabidopsis and the halophyte thellungiella: role of the plastid terminal oxidase as an alternative electron sink.

PubMed

Stepien, Piotr; Johnson, Giles N

2009-02-01

The effects of short-term salt stress on gas exchange and the regulation of photosynthetic electron transport were examined in Arabidopsis (Arabidopsis thaliana) and its salt-tolerant close relative Thellungiella (Thellungiella halophila). Plants cultivated on soil were challenged for 2 weeks with NaCl. Arabidopsis showed a much higher sensitivity to salt than Thellungiella; while Arabidopsis plants were unable to survive exposure to greater than 150 mM salt, Thellugiella could tolerate concentrations as high as 500 mM with only minimal effects on gas exchange. Exposure of Arabidopsis to sublethal salt concentrations resulted in stomatal closure and inhibition of CO2 fixation. This lead to an inhibition of electron transport though photosystem II (PSII), an increase in cyclic electron flow involving only PSI, and increased nonphotochemical quenching of chlorophyll fluorescence. In contrast, in Thellungiella, although gas exchange was marginally inhibited by high salt and PSI was unaffected, there was a large increase in electron flow involving PSII. This additional electron transport activity is oxygen dependent and sensitive to the alternative oxidase inhibitor n-propyl gallate. PSII electron transport in Thellungiella showed a reduced sensitivity to 2'-iodo-6-isopropyl-3-methyl-2',4,4'-trinitrodiphenylether, an inhibitor of the cytochrome b6f complex. At the same time, we observed a substantial up-regulation of a protein reacting with antibodies raised against the plastid terminal oxidase. No such up-regulation was seen in Arabidopsis. We conclude that in salt-stressed Thellungiella, plastid terminal oxidase acts as an alternative electron sink, accounting for up to 30% of total PSII electron flow.

Eflect of Relative Humidity on the Bactericidal Activity of Propylene Oxide Vapor1

PubMed Central

Himmelfarb, Philip; El-Bisi, Hamed M.; Read, R. B.; Litsky, Warren

1962-01-01

Because of the low toxicity of its breakdown product, propylene oxide (PO) vapor will play an increasingly important role in the preservation of foods. It is therefore necessary that the diversified variables which influence effectiveness of PO treatment be thoroughly investigated and understood prior to advocating its general use in industry. Accordingly, the present study was undertaken to determine the effect of relative humidity (RH) upon the bactericidal activity of PO sterilant atmospheres. Death rates were established at increasing RH values of < 1, 52, 65, 80, and 98% and under constant conditions of concentration, pressure, and temperature. Test bacterial populations were preconditioned to corresponding moisture levels. Results indicate that gram-positive cocci were relatively insensitive to PO vapor at dry conditions but became progressively less resistant with the increase in RH up to a maximum of 65 to 70%. Lactic acid bacteria and gram-negative rods were much more sensitive at dry conditions, showing much less dependency upon water vapor. Bacillus subtilis spores elicited the highest degree of resistance but the death rate substantially increased with the increase in RH. PMID:13954626

Agricultural Polymers as Corrosion Inhibitors

USDA-ARS?s Scientific Manuscript database

Agricultural polymers were composed of extra-cellular polysaccharides secreted by Leuconostoc mesenteroides have been shown to inhibit corrosion on corrosion-sensitive metals. The substantially pure exopolysaccharide has a general structure consisting of alpha(1-6)-linked D-glucose backbone and appr...

Assessing snow extent data sets over North America to inform and improve trace gas retrievals from solar backscatter

NASA Astrophysics Data System (ADS)

Cooper, Matthew J.; Martin, Randall V.; Lyapustin, Alexei I.; McLinden, Chris A.

2018-05-01

Accurate representation of surface reflectivity is essential to tropospheric trace gas retrievals from solar backscatter observations. Surface snow cover presents a significant challenge due to its variability and thus snow-covered scenes are often omitted from retrieval data sets; however, the high reflectance of snow is potentially advantageous for trace gas retrievals. We first examine the implications of surface snow on retrievals from the upcoming TEMPO geostationary instrument for North America. We use a radiative transfer model to examine how an increase in surface reflectivity due to snow cover changes the sensitivity of satellite retrievals to NO2 in the lower troposphere. We find that a substantial fraction (> 50 %) of the TEMPO field of regard can be snow covered in January and that the average sensitivity to the tropospheric NO2 column substantially increases (doubles) when the surface is snow covered.We then evaluate seven existing satellite-derived or reanalysis snow extent products against ground station observations over North America to assess their capability of informing surface conditions for TEMPO retrievals. The Interactive Multisensor Snow and Ice Mapping System (IMS) had the best agreement with ground observations (accuracy of 93 %, precision of 87 %, recall of 83 %). Multiangle Implementation of Atmospheric Correction (MAIAC) retrievals of MODIS-observed radiances had high precision (90 % for Aqua and Terra), but underestimated the presence of snow (recall of 74 % for Aqua, 75 % for Terra). MAIAC generally outperforms the standard MODIS products (precision of 51 %, recall of 43 % for Aqua; precision of 69 %, recall of 45 % for Terra). The Near-real-time Ice and Snow Extent (NISE) product had good precision (83 %) but missed a significant number of snow-covered pixels (recall of 45 %). The Canadian Meteorological Centre (CMC) Daily Snow Depth Analysis Data set had strong performance metrics (accuracy of 91 %, precision of 79 %, recall of 82 %). We use the Fscore, which balances precision and recall, to determine overall product performance (F = 85 %, 82 (82) %, 81 %, 58 %, 46 (54) % for IMS, MAIAC Aqua (Terra), CMC, NISE, MODIS Aqua (Terra), respectively) for providing snow cover information for TEMPO retrievals from solar backscatter observations. We find that using IMS to identify snow cover and enable inclusion of snow-covered scenes in clear-sky conditions across North America in January can increase both the number of observations by a factor of 2.1 and the average sensitivity to the tropospheric NO2 column by a factor of 2.7.

Impact of atmospheric and terrestrial CO2 feedbacks on fertilization-induced marine carbon uptake

NASA Astrophysics Data System (ADS)

Oschlies, A.

2009-08-01

The sensitivity of oceanic CO2 uptake to alterations in the marine biological carbon pump, such as brought about by natural or purposeful ocean fertilization, has repeatedly been investigated by studies employing numerical biogeochemical ocean models. It is shown here that the results of such ocean-centered studies are very sensitive to the assumption made about the response of the carbon reservoirs on the atmospheric side of the sea surface. Assumptions made include prescribed atmospheric pCO2, an interactive atmospheric CO2 pool exchanging carbon with the ocean but not with the terrestrial biosphere, and an interactive atmosphere that exchanges carbon with both oceanic and terrestrial carbon pools. The impact of these assumptions on simulated annual to millennial oceanic carbon uptake is investigated for a hypothetical increase in the C:N ratio of the biological pump and for an idealized enhancement of phytoplankton growth. Compared to simulations with interactive atmosphere, using prescribed atmospheric pCO2 overestimates the sensitivity of the oceanic CO2 uptake to changes in the biological pump, by about 2%, 25%, 100%, and >500% on annual, decadal, centennial, and millennial timescales, respectively. The smaller efficiency of the oceanic carbon uptake under an interactive atmosphere is due to the back flux of CO2 that occurs when atmospheric CO2 is reduced. Adding an interactive terrestrial carbon pool to the atmosphere-ocean model system has a small effect on annual timescales, but increases the simulated fertilization-induced oceanic carbon uptake by about 4%, 50%, and 100% on decadal, centennial, and millennial timescales, respectively, for pCO2 sensitivities of the terrestrial carbon storage in the middle range of the C4MIP models (Friedlingstein et al., 2006). For such sensitivities, a substantial fraction of oceanic carbon uptake induced by natural or purposeful ocean fertilization originates, on timescales longer than decades, not from the atmosphere but from the terrestrial biosphere.

The impact of parametrized convection on cloud feedback.

PubMed

Webb, Mark J; Lock, Adrian P; Bretherton, Christopher S; Bony, Sandrine; Cole, Jason N S; Idelkadi, Abderrahmane; Kang, Sarah M; Koshiro, Tsuyoshi; Kawai, Hideaki; Ogura, Tomoo; Roehrig, Romain; Shin, Yechul; Mauritsen, Thorsten; Sherwood, Steven C; Vial, Jessica; Watanabe, Masahiro; Woelfle, Matthew D; Zhao, Ming

2015-11-13

We investigate the sensitivity of cloud feedbacks to the use of convective parametrizations by repeating the CMIP5/CFMIP-2 AMIP/AMIP + 4K uniform sea surface temperature perturbation experiments with 10 climate models which have had their convective parametrizations turned off. Previous studies have suggested that differences between parametrized convection schemes are a leading source of inter-model spread in cloud feedbacks. We find however that 'ConvOff' models with convection switched off have a similar overall range of cloud feedbacks compared with the standard configurations. Furthermore, applying a simple bias correction method to allow for differences in present-day global cloud radiative effects substantially reduces the differences between the cloud feedbacks with and without parametrized convection in the individual models. We conclude that, while parametrized convection influences the strength of the cloud feedbacks substantially in some models, other processes must also contribute substantially to the overall inter-model spread. The positive shortwave cloud feedbacks seen in the models in subtropical regimes associated with shallow clouds are still present in the ConvOff experiments. Inter-model spread in shortwave cloud feedback increases slightly in regimes associated with trade cumulus in the ConvOff experiments but is quite similar in the most stable subtropical regimes associated with stratocumulus clouds. Inter-model spread in longwave cloud feedbacks in strongly precipitating regions of the tropics is substantially reduced in the ConvOff experiments however, indicating a considerable local contribution from differences in the details of convective parametrizations. In both standard and ConvOff experiments, models with less mid-level cloud and less moist static energy near the top of the boundary layer tend to have more positive tropical cloud feedbacks. The role of non-convective processes in contributing to inter-model spread in cloud feedback is discussed. © 2015 The Authors.

The impact of parametrized convection on cloud feedback

PubMed Central

Webb, Mark J.; Lock, Adrian P.; Bretherton, Christopher S.; Bony, Sandrine; Cole, Jason N. S.; Idelkadi, Abderrahmane; Kang, Sarah M.; Koshiro, Tsuyoshi; Kawai, Hideaki; Ogura, Tomoo; Roehrig, Romain; Shin, Yechul; Mauritsen, Thorsten; Sherwood, Steven C.; Vial, Jessica; Watanabe, Masahiro; Woelfle, Matthew D.; Zhao, Ming

2015-01-01

We investigate the sensitivity of cloud feedbacks to the use of convective parametrizations by repeating the CMIP5/CFMIP-2 AMIP/AMIP + 4K uniform sea surface temperature perturbation experiments with 10 climate models which have had their convective parametrizations turned off. Previous studies have suggested that differences between parametrized convection schemes are a leading source of inter-model spread in cloud feedbacks. We find however that ‘ConvOff’ models with convection switched off have a similar overall range of cloud feedbacks compared with the standard configurations. Furthermore, applying a simple bias correction method to allow for differences in present-day global cloud radiative effects substantially reduces the differences between the cloud feedbacks with and without parametrized convection in the individual models. We conclude that, while parametrized convection influences the strength of the cloud feedbacks substantially in some models, other processes must also contribute substantially to the overall inter-model spread. The positive shortwave cloud feedbacks seen in the models in subtropical regimes associated with shallow clouds are still present in the ConvOff experiments. Inter-model spread in shortwave cloud feedback increases slightly in regimes associated with trade cumulus in the ConvOff experiments but is quite similar in the most stable subtropical regimes associated with stratocumulus clouds. Inter-model spread in longwave cloud feedbacks in strongly precipitating regions of the tropics is substantially reduced in the ConvOff experiments however, indicating a considerable local contribution from differences in the details of convective parametrizations. In both standard and ConvOff experiments, models with less mid-level cloud and less moist static energy near the top of the boundary layer tend to have more positive tropical cloud feedbacks. The role of non-convective processes in contributing to inter-model spread in cloud feedback is discussed. PMID:26438278

Using Replicates in Information Retrieval Evaluation.

PubMed

Voorhees, Ellen M; Samarov, Daniel; Soboroff, Ian

2017-09-01

This article explores a method for more accurately estimating the main effect of the system in a typical test-collection-based evaluation of information retrieval systems, thus increasing the sensitivity of system comparisons. Randomly partitioning the test document collection allows for multiple tests of a given system and topic (replicates). Bootstrap ANOVA can use these replicates to extract system-topic interactions-something not possible without replicates-yielding a more precise value for the system effect and a narrower confidence interval around that value. Experiments using multiple TREC collections demonstrate that removing the topic-system interactions substantially reduces the confidence intervals around the system effect as well as increases the number of significant pairwise differences found. Further, the method is robust against small changes in the number of partitions used, against variability in the documents that constitute the partitions, and the measure of effectiveness used to quantify system effectiveness.

Managing for Multifunctionality in Perennial Grain Crops

PubMed Central

Ryan, Matthew R; Crews, Timothy E; Culman, Steven W; DeHaan, Lee R; Hayes, Richard C; Jungers, Jacob M; Bakker, Matthew G

2018-01-01

Abstract Plant breeders are increasing yields and improving agronomic traits in several perennial grain crops, the first of which is now being incorporated into commercial food products. Integration strategies and management guidelines are needed to optimize production of these new crops, which differ substantially from both annual grain crops and perennial forages. To offset relatively low grain yields, perennial grain cropping systems should be multifunctional. Growing perennial grains for several years to regenerate soil health before rotating to annual crops and growing perennial grains on sloped land and ecologically sensitive areas to reduce soil erosion and nutrient losses are two strategies that can provide ecosystem services and support multifunctionality. Several perennial cereals can be used to produce both grain and forage, and these dual-purpose crops can be intercropped with legumes for additional benefits. Highly diverse perennial grain polycultures can further enhance ecosystem services, but increased management complexity might limit their adoption. PMID:29662249

Method of increasing power within an optical cavity with long path lengths

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leen, John Brian; Bramall, Nathan E.

A cavity-enhanced absorption spectroscopy instrument has an optical cavity with two or more cavity mirrors, one mirror of which having a hole or other aperture for injecting a light beam, and the same or another mirror of which being partially transmissive to allow exit of light to a detector. A spherical-spherical configuration with at least one astigmatic mirror or a spherical-cylindrical configuration where the spherical mirror could also be astigmatic prevents a reentrant condition wherein the injected beam would prematurely exit the cavity through the aperture. This combination substantially increases the number of passes of the injected beam through amore » sample volume for sensitive detection of chemical species even in less than ideal conditions including low power laser or LED sources, poor mirror reflectivity or detector noise at the wavelengths of interest, or cavity alignment issues such as vibration or temperature and pressure changes.« less

Wildlife strike risk assessment in several Italian airports: lessons from BRI and a new methodology implementation.

PubMed

Soldatini, Cecilia; Albores-Barajas, Yuri Vladimir; Lovato, Tomas; Andreon, Adriano; Torricelli, Patrizia; Montemaggiori, Alessandro; Corsa, Cosimo; Georgalas, Vyron

2011-01-01

The presence of wildlife in airport areas poses substantial hazards to aviation. Wildlife aircraft collisions (hereafter wildlife strikes) cause losses in terms of human lives and direct monetary losses for the aviation industry. In recent years, wildlife strikes have increased in parallel with air traffic increase and species habituation to anthropic areas. In this paper, we used an ecological approach to wildlife strike risk assessment to eight Italian international airports. The main achievement is a site-specific analysis that avoids flattening wildlife strike events on a large scale while maintaining comparable airport risk assessments. This second version of the Birdstrike Risk Index (BRI2) is a sensitive tool that provides different time scale results allowing appropriate management planning. The methodology applied has been developed in accordance with the Italian Civil Aviation Authority, which recognizes it as a national standard implemented in the advisory circular ENAC APT-01B.

Wildlife Strike Risk Assessment in Several Italian Airports: Lessons from BRI and a New Methodology Implementation

PubMed Central

Soldatini, Cecilia; Albores-Barajas, Yuri Vladimir; Lovato, Tomas; Andreon, Adriano; Torricelli, Patrizia; Montemaggiori, Alessandro; Corsa, Cosimo; Georgalas, Vyron

2011-01-01

The presence of wildlife in airport areas poses substantial hazards to aviation. Wildlife aircraft collisions (hereafter wildlife strikes) cause losses in terms of human lives and direct monetary losses for the aviation industry. In recent years, wildlife strikes have increased in parallel with air traffic increase and species habituation to anthropic areas. In this paper, we used an ecological approach to wildlife strike risk assessment to eight Italian international airports. The main achievement is a site-specific analysis that avoids flattening wildlife strike events on a large scale while maintaining comparable airport risk assessments. This second version of the Birdstrike Risk Index (BRI2) is a sensitive tool that provides different time scale results allowing appropriate management planning. The methodology applied has been developed in accordance with the Italian Civil Aviation Authority, which recognizes it as a national standard implemented in the advisory circular ENAC APT-01B. PMID:22194950

Using Replicates in Information Retrieval Evaluation

PubMed Central

VOORHEES, ELLEN M.; SAMAROV, DANIEL; SOBOROFF, IAN

2018-01-01

This article explores a method for more accurately estimating the main effect of the system in a typical test-collection-based evaluation of information retrieval systems, thus increasing the sensitivity of system comparisons. Randomly partitioning the test document collection allows for multiple tests of a given system and topic (replicates). Bootstrap ANOVA can use these replicates to extract system-topic interactions—something not possible without replicates—yielding a more precise value for the system effect and a narrower confidence interval around that value. Experiments using multiple TREC collections demonstrate that removing the topic-system interactions substantially reduces the confidence intervals around the system effect as well as increases the number of significant pairwise differences found. Further, the method is robust against small changes in the number of partitions used, against variability in the documents that constitute the partitions, and the measure of effectiveness used to quantify system effectiveness. PMID:29905334

Cosmic ray antiprotons at high energies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winkler, Martin Wolfgang, E-mail: martin.winkler@su.se

2017-02-01

Cosmic ray antiprotons provide a powerful tool to probe dark matter annihilations in our galaxy. The sensitivity of this important channel is, however, diluted by sizable uncertainties in the secondary antiproton background. In this work, we improve the calculation of secondary antiproton production with a particular focus on the high energy regime. We employ the most recent collider data and identify a substantial increase of antiproton cross sections with energy. This increase is driven by the violation of Feynman scaling as well as by an enhanced strange hyperon production. The updated antiproton production cross sections are made publicly available formore » independent use in cosmic ray studies. In addition, we provide the correlation matrix of cross section uncertainties for the AMS-02 experiment. At high energies, the new cross sections improve the compatibility of the AMS-02 data with a pure secondary origin of antiprotons in cosmic rays.« less

Processing Deficits of Motion of Contrast-Modulated Gratings in Anisometropic Amblyopia

PubMed Central

Liu, Zhongjian; Hu, Xiaopeng; Yu, Yong-Qiang; Zhou, Yifeng

2014-01-01

Several studies have indicated substantial processing deficits for static second-order stimuli in amblyopia. However, less is known about the perception of second-order moving gratings. To investigate this issue, we measured the contrast sensitivity for second-order (contrast-modulated) moving gratings in seven anisometropic amblyopes and ten normal controls. The measurements were performed with non-equated carriers and a series of equated carriers. For comparison, the sensitivity for first-order motion and static second-order stimuli was also measured. Most of the amblyopic eyes (AEs) showed reduced sensitivity for second-order moving gratings relative to their non-amblyopic eyes (NAEs) and the dominant eyes (CEs) of normal control subjects, even when the detectability of the noise carriers was carefully controlled, suggesting substantial processing deficits of motion of contrast-modulated gratings in anisometropic amblyopia. In contrast, the non-amblyopic eyes of the anisometropic amblyopes were relatively spared. As a group, NAEs showed statistically comparable performance to CEs. We also found that contrast sensitivity for static second-order stimuli was strongly impaired in AEs and part of the NAEs of anisometropic amblyopes, consistent with previous studies. In addition, some amblyopes showed impaired performance in perception of static second-order stimuli but not in that of second-order moving gratings. These results may suggest a dissociation between the processing of static and moving second-order gratings in anisometropic amblyopia. PMID:25409477

Relating Neuronal to Behavioral Performance: Variability of Optomotor Responses in the Blowfly

PubMed Central

Rosner, Ronny; Warzecha, Anne-Kathrin

2011-01-01

Behavioral responses of an animal vary even when they are elicited by the same stimulus. This variability is due to stochastic processes within the nervous system and to the changing internal states of the animal. To what extent does the variability of neuronal responses account for the overall variability at the behavioral level? To address this question we evaluate the neuronal variability at the output stage of the blowfly's (Calliphora vicina) visual system by recording from motion-sensitive interneurons mediating head optomotor responses. By means of a simple modelling approach representing the sensory-motor transformation, we predict head movements on the basis of the recorded responses of motion-sensitive neurons and compare the variability of the predicted head movements with that of the observed ones. Large gain changes of optomotor head movements have previously been shown to go along with changes in the animals' activity state. Our modelling approach substantiates that these gain changes are imposed downstream of the motion-sensitive neurons of the visual system. Moreover, since predicted head movements are clearly more reliable than those actually observed, we conclude that substantial variability is introduced downstream of the visual system. PMID:22066014

Asymmetry of Reinforcement and Punishment in Human Choice

PubMed Central

Rasmussen, Erin B; Newland, M Christopher

2008-01-01

The hypothesis that a penny lost is valued more highly than a penny earned was tested in human choice. Five participants clicked a computer mouse under concurrent variable-interval schedules of monetary reinforcement. In the no-punishment condition, the schedules arranged monetary gain. In the punishment conditions, a schedule of monetary loss was superimposed on one response alternative. Deviations from generalized matching using the free parameters c (sensitivity to reinforcement) and log k (bias) were compared in the no-punishment and punishment conditions. The no-punishment conditions yielded values of log k that approximated zero for all participants, indicating no bias. In the punishment condition, values of log k deviated substantially from zero, revealing a 3-fold bias toward the unpunished alternative. Moreover, the c parameters were substantially smaller in punished conditions. The values for bias and sensitivity under punishment did not change significantly when the measure of net reinforcers (gains minus losses) was applied to the analysis. These results mean that punishment reduced the sensitivity of behavior to reinforcement and biased performance toward the unpunished alternative. We concluded that a single punisher subtracted more value than a single reinforcer added, indicating an asymmetry in the law of effect. PMID:18422016

BODIPY-Based Fluorescent Probes for Sensing Protein Surface-Hydrophobicity.

PubMed

Dorh, Nethaniah; Zhu, Shilei; Dhungana, Kamal B; Pati, Ranjit; Luo, Fen-Tair; Liu, Haiying; Tiwari, Ashutosh

2015-12-18

Mapping surface hydrophobic interactions in proteins is key to understanding molecular recognition, biological functions, and is central to many protein misfolding diseases. Herein, we report synthesis and application of new BODIPY-based hydrophobic sensors (HPsensors) that are stable and highly fluorescent for pH values ranging from 7.0 to 9.0. Surface hydrophobic measurements of proteins (BSA, apomyoglobin, and myoglobin) by these HPsensors display much stronger signal compared to 8-anilino-1-naphthalene sulfonic acid (ANS), a commonly used hydrophobic probe; HPsensors show a 10- to 60-fold increase in signal strength for the BSA protein with affinity in the nanomolar range. This suggests that these HPsensors can be used as a sensitive indicator of protein surface hydrophobicity. A first principle approach is used to identify the molecular level mechanism for the substantial increase in the fluorescence signal strength. Our results show that conformational change and increased molecular rigidity of the dye due to its hydrophobic interaction with protein lead to fluorescence enhancement.

Ma Huang Tang ameliorates asthma though modulation of Th1/Th2 cytokines and inhibition of Th17 cells in ovalbumin-sensitized mice.

PubMed

Ma, Chun-Hua; Ma, Zhan-Qiang; Fu, Qiang; Ma, Shi-Ping

2014-05-01

Ma Huang Tang (Ephedra decoction, MHT) is a famous classical formula from Shang Han Lun by Zhang Zhongjing in the Han Dynasty. The anti-asthmatic effects of MHT and the possible mechanisms were tested. An asthma model was established by ovalbumin (OVA)-induction in mice. A total of forty-eight mice were randomly assigned to six experimental groups: control, model, dexamethasone (2 mg·kg(-1)) and MHT (5, 10, and 20 mg·kg(-1)). Airway resistance (Raw) was measured by the forced oscillation technique, histological studies were evaluated by hematoxylin and eosin (HE) staining, Th1/Th2 and Th17 cytokines were evaluated by enzyme-linked immunosorbent assay (ELISA), and Th17 cells were evaluated by flow cytometry (FCM). This study demonstrated that MHT inhibited OVA-induced increases in Raw and eosinophil count; interleukin (IL)-4 and IL-17 levels were recovered in bronchoalveolar lavage fluid, increased IFN-γ level in bronchoalveolar lavage fluid. Histological studies demonstrated that MHT substantially inhibited OVA-induced eosinophilia in lung tissue. Flow cytometry studies demonstrated that MHT substantially inhibited Th17 cells. These findings suggest that MHT may effectively ameliorate the progression of asthma, and could be further investigated for potential use as a therapy for patients with allergic asthma. Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

How Important is Parental Education for Child Nutrition?

PubMed

Alderman, Harold; Headey, Derek D

2017-06-01

Existing evidence on the impacts of parental education on child nutrition is plagued by both internal and external validity concerns. In this paper we try to address these concerns through a novel econometric analysis of 376,992 preschool children from 56 developing countries. We compare a naïve least square model to specifications that include cluster fixed effects and cohort-based educational rankings to reduce biases from omitted variables before gauging sensitivity to sub-samples and exploring potential explanations of education-nutrition linkages. We find that the estimated nutritional returns to parental education are: (a) substantially reduced in models that include fixed effects and cohort rankings; (b) larger for mothers than for fathers; (c) generally increasing, and minimal for primary education; (d) increasing with household wealth; (e) larger in countries/regions with higher burdens of undernutrition; (f) larger in countries/regions with higher schooling quality; and (g) highly variable across country sub-samples. These results imply substantial uncertainty and variability in the returns to education, but results from the more stringent models imply that even the achievement of very ambitious education targets would only lead to modest reductions in stunting rates in high-burden countries. We speculate that education might have more impact on the nutritional status of the next generation if school curricula focused on directly improving health and nutritional knowledge of future parents.

The cost-effectiveness of immediate treatment or watch and wait with deferred chemotherapy for advanced asymptomatic follicular lymphoma.

PubMed

Prettyjohns, Matthew; Hoskin, Peter; McNamara, Christopher; Linch, David

2018-01-01

Recent evidence has shown that immediate treatment with rituximab induction, with and without maintenance, substantially reduces the need for further treatment in patients with advanced asymptomatic follicular lymphoma. This analysis estimates the cost-effectiveness of immediate treatment approaches in comparison to a watch and wait approach from the perspective of the UK National Health Service. A Markov decision model was developed to estimate the cost-effectiveness of treatment strategies in patients with asymptomatic follicular lymphoma. The model was populated using effectiveness data from a systematic literature review with the key clinical data sourced from a randomised trial, in which the treatment strategies were compared. Costs were estimated using UK national sources. In comparison to watchful waiting, both rituximab strategies were found to be more effective and cost saving. In comparison to rituximab induction, the addition of rituximab maintenance marginally increased effectiveness but substantially increased costs, resulting in an incremental cost-effectiveness ratio (ICER) of £69 406 per quality-adjusted life year (QALY). In probabilistic sensitivity analysis, rituximab induction was found to have a 68% probability of being cost-effective at a threshold of £20 000 per QALY. In conclusion, active treatment with rituximab induction is a cost-effective strategy to adopt in patients with asymptomatic follicular lymphoma. © 2017 John Wiley & Sons Ltd.

A crucial role for thiol antioxidants in estrogen-deficiency bone loss

PubMed Central

Lean, Jenny M.; Davies, Julie T.; Fuller, Karen; Jagger, Christopher J.; Kirstein, Barrie; Partington, Geoffrey A.; Urry, Zoë L.; Chambers, Timothy J.

2003-01-01

The mechanisms through which estrogen prevents bone loss are uncertain. Elsewhere, estrogen exerts beneficial actions by suppression of reactive oxygen species (ROS). ROS stimulate osteoclasts, the cells that resorb bone. Thus, estrogen might prevent bone loss by enhancing oxidant defenses in bone. We found that glutathione and thioredoxin, the major thiol antioxidants, and glutathione and thioredoxin reductases, the enzymes responsible for maintaining them in a reduced state, fell substantially in rodent bone marrow after ovariectomy and were rapidly normalized by exogenous 17-β estradiol. Moreover, administration of N-acetyl cysteine (NAC) or ascorbate, antioxidants that increase tissue glutathione levels, abolished ovariectomy-induced bone loss, while L-buthionine-(S,R)-sulphoximine (BSO), a specific inhibitor of glutathione synthesis, caused substantial bone loss. The 17-β estradiol increased glutathione and glutathione and thioredoxin reductases in osteoclast-like cells in vitro. Furthermore, in vitro NAC prevented osteoclast formation and NF-κB activation. BSO and hydrogen peroxide did the opposite. Expression of TNF-α, a target for NF-κB and a cytokine strongly implicated in estrogen-deficiency bone loss, was suppressed in osteoclasts by 17-β estradiol and NAC. These observations strongly suggest that estrogen deficiency causes bone loss by lowering thiol antioxidants in osteoclasts. This directly sensitizes osteoclasts to osteoclastogenic signals and entrains ROS-enhanced expression of cytokines that promote osteoclastic bone resorption. PMID:12975476

A hydrologic drying bias in water-resource impact analyses of anthropogenic climate change

USGS Publications Warehouse

Milly, Paul; Dunne, Krista A.

2017-01-01

For water-resource planning, sensitivity of freshwater availability to anthropogenic climate change (ACC) often is analyzed with “offline” hydrologic models that use precipitation and potential evapotranspiration (Ep) as inputs. Because Ep is not a climate-model output, an intermediary model of Ep must be introduced to connect the climate model to the hydrologic model. Several Ep methods are used. The suitability of each can be assessed by noting a credible Ep method for offline analyses should be able to reproduce climate models’ ACC-driven changes in actual evapotranspiration in regions and seasons of negligible water stress (Ew). We quantified this ability for seven commonly used Ep methods and for a simple proportionality with available energy (“energy-only” method). With the exception of the energy-only method, all methods tend to overestimate substantially the increase in Ep associated with ACC. In an offline hydrologic model, the Ep-change biases produce excessive increases in actual evapotranspiration (E), whether the system experiences water stress or not, and thence strong negative biases in runoff change, as compared to hydrologic fluxes in the driving climate models. The runoff biases are comparable in magnitude to the ACC-induced runoff changes themselves. These results suggest future hydrologic drying (wetting) trends likely are being systematically and substantially overestimated (underestimated) in many water-resource impact analyses.

Climate, Tree Growth, Forest Drought Stress, and Tree Mortality in Forests of Western North America: Long-Term Patterns and Recent Trends

NASA Astrophysics Data System (ADS)

Allen, C. D.; Williams, P.

2012-12-01

Ongoing climate changes are increasingly affecting the world's forests, particularly including high latitude and high elevation coniferous forests. Although forest growth has improved in some regions due to greater growing season length and warmth (perhaps along with increased atmospheric CO2 or N), large growth declines or increased mortality from droughts or hotter temperatures also are being observed. We present and interpret information on regional variation in climate-tree growth relationships and trends, and on patterns and trends of climate-related forest disturbances, from western North America. From 235 tree-ring chronologies in the Southwest US we show that tree-ring growth records from warmer southwestern sites are more sensitive to temperature than tree-ring growth records from cooler southwestern sites. Assessment of 59 tree-ring records from 11 species in the Cascade Mountains of the Pacific Northwest shows that trees growing in cool places respond positively to increased temperature and trees in warm places respond negatively, implying that trees historically not sensitive to temperature may become sensitive as mean temperatures warm. An analysis of 59 white spruce populations in Alaska supports the hypothesis that warming has caused tree growth to lose sensitivity to cold temperatures. Comparing ring widths to temperature during just the coldest 50% of years during the 20th century, tree growth was sensitive to cold temperatures, and this effect was strongest at the coldest sites; whereas during the warmest 50% of years, trees were not at all sensitive to cold temperatures, even at the cold sites. Drought and vapor pressure deficit are among the variables that emerge as being increasingly important to these Alaska boreal forests as mean temperatures rise. Most recently, from 346 tree-ring chronologies in the Southwest US we establish a tree-ring-based Forest Drought Stress Index (FDSI) for the three most widespread conifer species (Pinus edulis, Pinus ponderosa, and Pseudotsuga menziesii) in this region. FDSI responds sensitively and nonlinearly to growing season daily maximum temperatures which increase vapor pressure deficit, resulting in greater tree physiological stress and reduced tree growth. Drought conditions and warming temperatures in the Southwest since ca. 1996 have caused FDSI values in particular years since 2000 to start to exceed the most extreme values reconstructed from tree-rings for the past 1000 years for this region. FDSI demonstrates strong correlations with the spatial extent of major forest disturbances in the Southwest, including high-severity wildfire and bark beetle infestations, which over the past 20 years also have affected historically unprecedented levels. Similar trends of increasing extent and severity of forest disturbances are apparent across large portions of western North America. For the Southwest US, given relatively robust projections of substantial further increases in warmer temperatures and drought stress in coming decades, by ~2050 projected levels of FDSI and associated disturbances would reach extreme values, suggesting that current forest ecosystems likely would be forced to reorganize through wholesale tree mortality and the establishment of new dominant species.

Clouds Versus Carbon: Predicting Vegetation Roughness by Maximizing Productivity

NASA Technical Reports Server (NTRS)

Olsen, Lola M.

2004-01-01

Surface roughness is one of the dominant vegetation properties that affects land surface exchange of energy, water, carbon, and momentum with the overlying atmosphere. We hypothesize that the canopy structure of terrestrial vegetation adapts optimally to climate by maximizing productivity, leading to an optimum surface roughness. An optimum should exist because increasing values of surface roughness cause increased surface exchange, leading to increased supply of carbon dioxide for photosynthesis. At the same time, increased roughness enhances evapotranspiration and cloud cover, thereby reducing the supply of photosynthetically active radiation. We demonstrate the optimum through sensitivity simulations using a coupled dynamic vegetation-climate model for present day conditions, in which we vary the value of surface roughness for vegetated surfaces. We find that the maximum in productivity occurs at a roughness length of 2 meters, a value commonly used to describe the roughness of today's forested surfaces. The sensitivity simulations also illustrate the strong climatic impacts of vegetation roughness on the energy and water balances over land: with increasing vegetation roughness, solar radiation is reduced by up to 20 W/sq m in the global land mean, causing shifts in the energy partitioning and leading to general cooling of the surface by 1.5 K. We conclude that the roughness of vegetated surfaces can be understood as a reflection of optimum adaptation, and it is associated with substantial changes in the surface energy and water balances over land. The role of the cloud feedback in shaping the optimum underlines the importance of an integrated perspective that views vegetation and its adaptive nature as an integrated component of the Earth system.

Synergistic interactions between airway afferent nerve subtypes regulating the cough reflex in guinea-pigs

PubMed Central

Mazzone, Stuart B; Mori, Nanako; Canning, Brendan J

2005-01-01

Cough initiated from the trachea and larynx in anaesthetized guinea-pigs is mediated by capsaicin-insensitive, mechanically sensitive vagal afferent neurones. Tachykinin-containing, capsaicin-sensitive C-fibres also innervate the airways and have been implicated in the cough reflex. Capsaicin-sensitive nerves act centrally and synergistically to modify reflex bronchospasm initiated by airway mechanoreceptor stimulation. The hypothesis that polymodal mechanoreceptors and capsaicin-sensitive afferent nerves similarly interact centrally to regulate coughing was addressed in this study. Cough was evoked from the tracheal mucosa either electrically (16 Hz, 10 s trains, 1–10 V) or by citric acid (0.001–2 m). Neither capsaicin nor bradykinin evoked a cough when applied to the trachea of anaesthetized guinea-pigs, but they substantially reduced the electrical threshold for initiating the cough reflex. The TRPV1 receptor antagonist capsazepine prevented the increased cough sensitivity induced by capsaicin. These effects of topically applied capsaicin and bradykinin were not due to interactions between afferent nerve subtypes within the tracheal wall or a direct effect on the cough receptors, as they were mimicked by nebulizing 1 mg ml−1 bradykinin into the lower airways and by microinjecting 0.5 nmol capsaicin into nucleus of the solitary tract (nTS). Citric acid-induced coughing was also potentiated by inhalation of bradykinin. The effects of tracheal capsaicin challenge on cough were mimicked by microinjecting substance P (0.5–5 nmol) into the nTS and prevented by intracerebroventricular administration (20 nmol h−1) of the neurokinin receptor antagonists CP99994 or SB223412. Tracheal application of these antagonists was without effect. C-fibre activation may thus sensitize the cough reflex via central mechanisms. PMID:16051625

Assessing change in sensitivity of tropical vegetation to climate based on wavelet analysis

NASA Astrophysics Data System (ADS)

Claessen, J.; Martens, B.; Verhoest, N.; Molini, A.; Miralles, D. G.

2017-12-01

Vegetation dynamics are driven by climate, and at the same time they play a key role in forcing the different bio-geochemical cycles. As climate change leads to an increase in frequency and intensity of hydro-meteorological extremes, vegetation is expected to respond to these changes, and subsequently feed back on their occurrence. Future responses can be better understood by analysing the past using time series of different vegetation diagnostics observed from space, both in the optical and microwave domain. In this contribution, the climatic drivers (air temperature, precipitation, and incoming radiation) of these different vegetation diagnostics are analysed using a monthly global data-cube of 32 years at a 0.25° resolution. To do so, we analyse the wavelet coherence between each vegetation index and the climatic drivers of vegetation. The use of wavelet coherence allows unveiling the different response and sensitivity of the diverse vegetation indices to their climatic drivers, simultaneously in the time and frequency domains. Our results show that the wavelet-based statistics are suitable for extracting information from the different vegetation indices. Areas of high rainfall volumes are characterised by a strong control of radiation and temperature over vegetation. At higher latitudes, the positive trends in all vegetation diagnostics agree with the hypothesis of a greening pattern, which is coherent with the increase in temperature. At the same time, substantial differences can be observed between the responses of the different vegetation indices as well. As an example, the VOD - thought to be a close proxy for vegetation water content - shows a larger sensitivity to precipitation than traditional optical indices such as the NDVI. Further, important temporal changes in the wavelet coherence between vegetation and climate are identified. For instance, the Amazonian rainforest shows an increased correspondence with precipitation dynamics, indicating positive shifts in ecosystem sensitivity to water availability, which can arguably be related to an increase in the amplitude of the seasonal cycle in rainfall. These results are in line with the expected intensification of the water cycle due to climate change and point to the complex response of the biosphere to climatic changes.

Local indicators of geocoding accuracy (LIGA): theory and application

PubMed Central

Jacquez, Geoffrey M; Rommel, Robert

2009-01-01

Background Although sources of positional error in geographic locations (e.g. geocoding error) used for describing and modeling spatial patterns are widely acknowledged, research on how such error impacts the statistical results has been limited. In this paper we explore techniques for quantifying the perturbability of spatial weights to different specifications of positional error. Results We find that a family of curves describes the relationship between perturbability and positional error, and use these curves to evaluate sensitivity of alternative spatial weight specifications to positional error both globally (when all locations are considered simultaneously) and locally (to identify those locations that would benefit most from increased geocoding accuracy). We evaluate the approach in simulation studies, and demonstrate it using a case-control study of bladder cancer in south-eastern Michigan. Conclusion Three results are significant. First, the shape of the probability distributions of positional error (e.g. circular, elliptical, cross) has little impact on the perturbability of spatial weights, which instead depends on the mean positional error. Second, our methodology allows researchers to evaluate the sensitivity of spatial statistics to positional accuracy for specific geographies. This has substantial practical implications since it makes possible routine sensitivity analysis of spatial statistics to positional error arising in geocoded street addresses, global positioning systems, LIDAR and other geographic data. Third, those locations with high perturbability (most sensitive to positional error) and high leverage (that contribute the most to the spatial weight being considered) will benefit the most from increased positional accuracy. These are rapidly identified using a new visualization tool we call the LIGA scatterplot. Herein lies a paradox for spatial analysis: For a given level of positional error increasing sample density to more accurately follow the underlying population distribution increases perturbability and introduces error into the spatial weights matrix. In some studies positional error may not impact the statistical results, and in others it might invalidate the results. We therefore must understand the relationships between positional accuracy and the perturbability of the spatial weights in order to have confidence in a study's results. PMID:19863795

Is 2 Degrees Achievable? The Cold Turkey Experiment

NASA Astrophysics Data System (ADS)

Schwartz, S. E.

2017-12-01

The 2015 Paris Agreement calls for collective international action to hold the increase in global average temperature to well below 2˚C above preindustrial levels and to pursue efforts to limit the increase to 1.5°C. How much would carbon dioxide emissions have to be reduced to achieve these objectives, or can these objectives even be achieved at all? These questions are examined using a global energy balance model to carry out a "cold turkey" experiment in which emissions from fossil fuel combustion are abruptly halted; this is a limiting case for any practically achievable gradual reduction in emissions. The model study halts emissions not just of CO2 but also of atmospheric aerosols and precursor gases. These aerosols are thought to be offsetting a substantial but highly uncertain fraction of the radiative forcing of anthropogenic CO2 by scattering solar radiation and by increasing cloud reflectivity. In contrast to CO2, which would persist in the atmosphere for decades to centuries, aerosols would be removed almost immediately after cessation of emissions. Consequently, at least in the early decades following abrupt cessation of emissions, net forcing and global temperature would likely increase, not decrease. The magnitude of the temperature increase that would ensue depends on Earth's climate sensitivity and current aerosol forcing. These quantities are quite uncertain but are strongly correlated through observational constraints. Within present uncertainty it cannot be stated with confidence whether the 2˚C target could be achieved even if emissions were abruptly halted. Future global CO2 emissions consistent with achieving the 2˚C target range from as much as 100 years at current emission rates if Earth's climate sensitivity is at the low end of the range estimated by the IPCC 2013 Assessment Report, to zero, the committed temperature increase already exceeding the 2˚C limit, if sensitivity is at the high end of the IPCC range. Figure. Global mean forcing and temperature response, for AR5 range of aerosol forcing and climate sensitivity, following abrupt cessation of emissions of CO2 and aerosols and precursor gases from fossil fuel combustion. Solid curves denote time-dependent forcing and response; dashed curves, response for CO2 maintained at its present value; dotted lines, instantaneous response.

Spiral Imaging in fMRI

PubMed Central

Glover, Gary H.

2011-01-01

T2*-weighted Blood Oxygen Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) requires efficient acquisition methods in order to fully sample the brain in a several second time period. The most widely used approach is Echo Planar Imaging (EPI), which utilizes a Cartesian trajectory to cover k-space. This trajectory is subject to ghosts from off-resonance and gradient imperfections and is intrinsically sensitive to cardiac-induced pulsatile motion from substantial first- and higher order moments of the gradient waveform near the k-space origin. In addition, only the readout direction gradient contributes significant energy to the trajectory. By contrast, the Spiral method samples k-space with an Archimedean or similar trajectory that begins at the k-space center and spirals to the edge (Spiral-out), or its reverse, ending at the origin (Spiral-in). Spiral methods have reduced sensitivity to motion, shorter readout times, improved signal recovery in most frontal and parietal brain regions, and exhibit blurring artifacts instead of ghosts or geometric distortion. Methods combining Spiral-in and Spiral-out trajectories have further advantages in terms of diminished susceptibility-induced signal dropout and increased BOLD signal. In measurements of temporal signal to noise ratio measured in 8 subjects, Spiral-in/out exhibited significant increases over EPI in voxel volumes recovered in frontal and whole brain regions (18% and 10%, respectively). PMID:22036995

Measurement of UO2 surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics

NASA Astrophysics Data System (ADS)

Tracy, Cameron L.; Chen, Chien-Hung; Park, Sulgiye; Davisson, M. Lee; Ewing, Rodney C.

2018-04-01

Nuclear forensics involves determination of the origin and history of interdicted nuclear materials based on the detection of signatures associated with their production and trafficking. The surface oxidation undergone by UO2 when exposed to air is a potential signature of its atmospheric exposure during handling and transport. To assess the sensitivity of this oxidation to atmospheric parameters, surface sensitive grazing-incidence x-ray diffraction (GIXRD) measurements were performed on UO2 samples exposed to air of varying relative humidity (34%, 56%, and 95% RH) and temperature (room temperature, 50 °C, and 100 °C). Near-surface unit cell contraction was observed following exposure, indicating oxidation of the surface and accompanying reduction of the uranium cation ionic radii. The extent of unit cell contraction provides a measure of the extent of oxidation, allowing for comparison of the effects of various exposure conditions. No clear influence of relative humidity on the extent of oxidation was observed, with samples exhibiting similar degrees of unit cell contraction at all relative humidities investigated. In contrast, the thickness of the oxidized layers increased substantially with increasing temperature, such that differences on the order of 10 °C yielded readily observable crystallographic signatures of the exposure conditions.

The relationship between carers' report of autistic traits and clinical diagnoses of autism spectrum disorders in adults with intellectual disability.

PubMed

Bhaumik, Sabyasachi; Tyrer, Freya; Barrett, Mary; Tin, Nyunt; McGrother, Catherine W; Kiani, Reza

2010-01-01

It is often difficult to determine the triad of impairments and whether autistic features are the consequence of intellectual impairment or autism spectrum disorders in people with intellectual disability (ID). The aim of the current study was to investigate the relationship between carer-reported autistic traits and independent diagnoses of autism spectrum disorders (ASD). Data were collected on carers' subjective report of autistic traits and clinical diagnoses of ASD. Of 1145 adults with ID identified, 220 (19%) individuals had a diagnosis of ASD, and 778 (68%) individuals had at least one autistic trait. Optimal sensitivity and specificity were achieved with two or more autistic traits (sensitivity 63%; specificity 79%) and the positive predictive value increased substantially as the number of autistic traits increased. However, a significant proportion of individuals with ID who did not have a diagnosis of ASD also displayed autistic traits. Our findings suggest that in the absence of other measures, the presence of autistic traits can serve as a useful proxy measure for ASD in research (and/or clinical settings). However, although information on autistic traits may help healthcare practitioners to identify people with possible ASD, it cannot be used alone to make a formal diagnosis. 2010 Elsevier Ltd. All rights reserved.

Plant food allergy: Influence of chemicals on plant allergens.

PubMed

Shahali, Youcef; Dadar, Maryam

2018-05-01

Plant-derived foods are the most common allergenic sources in adulthood. Owing to the rapidly increasing prevalence of plant food allergies in industrialized countries, the environmental factors are suspected to play a key role in development of allergic sensitization. The present article provides an overview of ways by which chemicals may influence the development and severity of allergic reactions to plant foods, with especial focus on plant allergens up-regulated under chemical stress. In plants, a substantial part of allergens have defense-related function and their expression is highly influenced by environmental stress and diseases. Pathogenesis-related proteins (PR) account for about 25% of plant food allergens and some are responsible for extensive cross-reactions between plant-derived foods, pollen and latex allergens. Chemicals released by anthropogenic sources such as agriculture, industrial activities and traffic-related air pollutants are potential drivers of the increasing sensitization to allergenic PRs by elevating their expression and by altering their immunogenicity through post-translational modifications. In addition, some orally-taken chemicals may act as immune adjuvants or directly trigger non-IgE mediated food allergy. Taken together, the current literature provides an overwhelming body of evidence supporting the fact that plant chemical exposure and chemicals in diet may enhance the allergenic properties of certain plant-derived foods. Copyright © 2018 Elsevier Ltd. All rights reserved.

Resonance-induced sensitivity enhancement method for conductivity sensors

NASA Technical Reports Server (NTRS)

Tai, Yu-Chong (Inventor); Shih, Chi-yuan (Inventor); Li, Wei (Inventor); Zheng, Siyang (Inventor)

2009-01-01

Methods and systems for improving the sensitivity of a variety of conductivity sensing devices, in particular capacitively-coupled contactless conductivity detectors. A parallel inductor is added to the conductivity sensor. The sensor with the parallel inductor is operated at a resonant frequency of the equivalent circuit model. At the resonant frequency, parasitic capacitances that are either in series or in parallel with the conductance (and possibly a series resistance) is substantially removed from the equivalent circuit, leaving a purely resistive impedance. An appreciably higher sensor sensitivity results. Experimental verification shows that sensitivity improvements of the order of 10,000-fold are possible. Examples of detecting particulates with high precision by application of the apparatus and methods of operation are described.

Aerosol indirect effect on tropospheric ozone via lightning

NASA Astrophysics Data System (ADS)

Yuan, Tianle; Remer, Lorraine A.; Bian, Huisheng; Ziemke, Jerald R.; Albrecht, Rachel; Pickering, Kenneth E.; Oreopoulos, Lazaros; Goodman, Steven J.; Yu, Hongbin; Allen, Dale J.

2012-09-01

Tropospheric ozone (O3) is a pollutant and major greenhouse gas and its radiative forcing is still uncertain. Inadequate understanding of processes related to O3 production, in particular those natural ones such as lightning, contributes to this uncertainty. Here we demonstrate a new effect of aerosol particles on O3production by affecting lightning activity and lightning-generated NOx (LNOx). We find that lightning flash rate increases at a remarkable rate of 30 times or more per unit of aerosol optical depth. We provide observational evidence that indicates the observed increase in lightning activity is caused by the influx of aerosols from a volcano. Satellite data analyses show O3is increased as a result of aerosol-induced increase in lightning and LNOx, which is supported by modle simulations with prescribed lightning change. O3production increase from this aerosol-lightning-ozone link is concentrated in the upper troposphere, where O3 is most efficient as a greenhouse gas. In the face of anthropogenic aerosol increase our findings suggest that lightning activity, LNOx and O3, especially in the upper troposphere, have all increased substantially since preindustrial time due to the proposed aerosol-lightning-ozone link, which implies a stronger O3 historical radiative forcing. Aerosol forcing therefore has a warming component via its effect on O3 production and this component has mostly been ignored in previous studies of climate forcing related to O3and aerosols. Sensitivity simulations suggest that 4-8% increase of column tropospheric ozone, mainly in the tropics, is expected if aerosol-lighting-ozone link is parameterized, depending on the background emission scenario. We note, however, substantial uncertainties remain on the exact magnitude of aerosol effect on tropospheric O3 via lightning. The challenges for obtaining a quantitative global estimate of this effect are also discussed. Our results have significant implications for understanding past and projecting future tropospheric O3forcing as well as wildfire changes and call for integrated investigations of the coupled aerosol-cloud-chemistry system.

Context-specific effects of musical expertise on audiovisual integration

PubMed Central

Bishop, Laura; Goebl, Werner

2014-01-01

Ensemble musicians exchange auditory and visual signals that can facilitate interpersonal synchronization. Musical expertise improves how precisely auditory and visual signals are perceptually integrated and increases sensitivity to asynchrony between them. Whether expertise improves sensitivity to audiovisual asynchrony in all instrumental contexts or only in those using sound-producing gestures that are within an observer's own motor repertoire is unclear. This study tested the hypothesis that musicians are more sensitive to audiovisual asynchrony in performances featuring their own instrument than in performances featuring other instruments. Short clips were extracted from audio-video recordings of clarinet, piano, and violin performances and presented to highly-skilled clarinetists, pianists, and violinists. Clips either maintained the audiovisual synchrony present in the original recording or were modified so that the video led or lagged behind the audio. Participants indicated whether the audio and video channels in each clip were synchronized. The range of asynchronies most often endorsed as synchronized was assessed as a measure of participants' sensitivities to audiovisual asynchrony. A positive relationship was observed between musical training and sensitivity, with data pooled across stimuli. While participants across expertise groups detected asynchronies most readily in piano stimuli and least readily in violin stimuli, pianists showed significantly better performance for piano stimuli than for either clarinet or violin. These findings suggest that, to an extent, the effects of expertise on audiovisual integration can be instrument-specific; however, the nature of the sound-producing gestures that are observed has a substantial effect on how readily asynchrony is detected as well. PMID:25324819

Measuring Listening Effort: Convergent Validity, Sensitivity, and Links With Cognitive and Personality Measures.

PubMed

Strand, Julia F; Brown, Violet A; Merchant, Madeleine B; Brown, Hunter E; Smith, Julia

2018-06-19

Listening effort (LE) describes the attentional or cognitive requirements for successful listening. Despite substantial theoretical and clinical interest in LE, inconsistent operationalization makes it difficult to make generalizations across studies. The aims of this large-scale validation study were to evaluate the convergent validity and sensitivity of commonly used measures of LE and assess how scores on those tasks relate to cognitive and personality variables. Young adults with normal hearing (N = 111) completed 7 tasks designed to measure LE, 5 tests of cognitive ability, and 2 personality measures. Scores on some behavioral LE tasks were moderately intercorrelated but were generally not correlated with subjective and physiological measures of LE, suggesting that these tasks may not be tapping into the same underlying construct. LE measures differed in their sensitivity to changes in signal-to-noise ratio and the extent to which they correlated with cognitive and personality variables. Given that LE measures do not show consistent, strong intercorrelations and differ in their relationships with cognitive and personality predictors, these findings suggest caution in generalizing across studies that use different measures of LE. The results also indicate that people with greater cognitive ability appear to use their resources more efficiently, thereby diminishing the detrimental effects associated with increased background noise during language processing.

Registration of immunoglobuline AB/AG reaction with planar polarization interferometer

NASA Astrophysics Data System (ADS)

Nabok, Alexei V.; Starodub, Nickolaj F.; Ray, Asim K.; Hassan, Aseel K.

2000-12-01

Immobilization of human immunoglobuline (IgG) (AG) and goat on human IGG antibodies (AB) as well as AB/AG specific reaction were studied with planar polarization interferometry (PPI). In this novel method, polarized laser beam was coupled into the planar waveguide made on silicon wafer and consisted of 20nm Si3N4 layer sandwiched between two 1.5 micrometers SiO2 layers with the sensing window etched in the top SIO2 layer. One of the immune components was deposited by means of polyelectrolyte self- assembly on top of the Si3N3 layer within the sensing window, P-component of the polarized light is sensitive to adsorption, while s-component serves as a reference. Thus the outcoming light intensity depends on the phase shift between s- and p-components. Different sequences of immobilization of the immune components were studied with both surface plasmon resonance (SPR) and PPI methods. It was shown that predeposition of a monolayer of protein A, which is believed to affect the orientation of the immune components, causes an additional increase in the sensitivity. PPI method allowed us to improve substantially the sensitivity towards AB/AG reaction as compared to traditional SPR method. Particularly, of specific binding of 3ng/ml AG was registered.

[Clinical features of Enterococcus faecium meningitis in children].

PubMed

Wang, Li-Yuan; Cai, Xiao-Tang; Wang, Zhi-Ling; Liu, Shun-Li; Xie, Yong-Mei; Zhou, Hui

2018-03-01

To summarize the clinical features of Enterococcus faecium meningitis in children. The clinical data of nine children with Enterococcus faecium meningitis were analyzed. In all the nine children, Enterococcus faecium was isolated from blood, cerebrospinal fluid, or peripherally inserted central catheters; 6 (67%) patients were neonates, 2 (22%) patients were younger than 6 months, and 1 (11%) patient was three years and four months of age. In those patients, 56% had high-risk factors before onset, which included intestinal infection, resettlement of drainage tube after surgery for hydrocephalus, skull fracture, perinatal maternal infection history, and catheter-related infection. The main symptoms were fever and poor response. In those patients, 22% had seizures; no child had meningeal irritation sign or disturbance of consciousness. The white blood cell count and level of C-reactive protein were normal or increased; the nucleated cell count in cerebrospinal fluid was normal or mildly elevated; the protein level was substantially elevated; the glucose level was decreased. The drug sensitivity test showed that bacteria were all sensitive to vancomycin and the vancomycin treatment was effective. Only one child had the complication of hydrocephalus. Enterococcus faecium meningitis occurs mainly in neonates and infants. The patients have atypical clinical features. A high proportion of patients with Enterococcus faecium meningitis have high-risk factors. Enterococcus faecium is sensitive to vancomycin.

Sexual-perception processes in acquaintance-targeted sexual aggression.

PubMed

Treat, Teresa A; Viken, Richard J

2018-05-01

This study analyzes data from seven published studies to examine whether three performance-based indices of men's misperception of women's sexual interest (MSI), derived from a self-report questionnaire, are associated with sexual-aggression history, rape-supportive attitudes, sociosexuality, problem drinking, and self-reported MSI. Almost 2000 undergraduate men judged the justifiability of a man's increasingly unwanted advances toward a woman on the Heterosocial Perception Survey-Revised. Participants self-reported any sexual-aggression history, and some completed questionnaires assessing rape-supportive attitudes, sociosexuality, problem drinking, and self-reported MSI. A three-parameter logistic function was fitted to participants' justifiability ratings within a non-linear mixed-effects framework, which provided precise participant-specific estimates of three sexual-perception processes (baseline justifiability, bias, and sensitivity). Sexual-aggression history and rape-supportive attitudes predicted: (a) reduced sensitivity to women's affect; (b) more liberal biases, such that the woman's affect had to be more negative before justifiability ratings dropped substantially; and (c) greater baseline justifiability of continued advances after a positive response. Sexual-aggression history and attitudes correlated more strongly with sensitivity than baseline justifiability; remaining variables showed the opposite pattern. This work underscores the role of sexual-perception processes in sexual aggression and illustrates the derivation of performance-based estimates of sexual-perception processes from questionnaire responses. © 2018 Wiley Periodicals, Inc.

[Allergic responses to date palm and pecan pollen in Israel].

PubMed

Waisel, Y; Keynan, N; Gil, T; Tayar, D; Bezerano, A; Goldberg, A; Geller-Bernstein, C; Dolev, Z; Tamir, R; Levy, I

1994-03-15

Date palm (Phoenix dactylifera) and pecan (Carya illinoensis) trees are commonly planted in Israel for fruit, for shade, or as ornamental plants. Pollen grains of both species are allergenic; however, the extent of exposure to such pollen and the incidence of allergic response have not been studied here. We therefore investigated skin-test responses to pollen extracts of 12 varieties of palm and 9 of pecan in 705 allergic patients living in 3 cities and 19 rural settlements. Sensitivity to the pollen extracts of both species was much higher among residents of rural than of urban communities. Moreover, there was a definite relationship between the abundance of these trees in a region and the incidence of skin responders to their pollen. Sensitivity was frequent in settlements rich in these 2 species, such as those with nearby commercial date or pecan plantations. In general, sensitivity to date pollen extracts was lower than to pecan. However, differences in skin responses to pollen extracts of various clones were substantiated. Air sampling revealed that pollen pollution decreased considerably with distance from the trees. At approximately 100 m from a source concentrations of airborne pollen were low. Since planting of male palm and pecan trees in population centers would increase pollen pollution, it should be avoided.

Reversal of diabetic peripheral neuropathy and new wound incidence: the role of MIRE.

PubMed

Powell, Mark W; Carnegie, Dale E; Burke, Thomas J

2004-01-01

To determine if improved foot sensitivity to the Semmes-Weinstein 10-g (5.07) monofilament, originally impaired because of diabetic peripheral neuropathy, might be associated with a reduced incidence of new diabetic foot wounds. Retrospective cohort study using a health status questionnaire. Sixty-eight individuals over age 64 with diabetes, diabetic peripheral neuropathy, and loss of protective sensation who had clinically demonstrable increases in foot sensation to the Semmes-Weinstein monofilament after treatment with monochromatic near infrared photo energy. After reversal of diabetic peripheral neuropathy following treatment with monochromatic near infrared photo energy, only 1 of 68 patients developed a new diabetic foot wound, for an incidence of 1.5%. Comparatively, the incidence previously reported in the Medicare-aged population with diabetes was 7.3%. Improved foot sensitivity to the Semmes-Weinstein monofilament in patients previously suffering from loss of protective sensation due to diabetic neuropathy appears to be associated with a lower incidence of new diabetic foot ulcers when compared with the expected incidence in the Medicare-aged population with diabetes. Therapeutic interventions that effectively improve foot sensitivity that has been previously diminished due to diabetic peripheral neuropathy may substantially reduce the incidence of new foot wounds in the Medicare-aged population with diabetes.

Crowdsourcing for error detection in cortical surface delineations.

PubMed

Ganz, Melanie; Kondermann, Daniel; Andrulis, Jonas; Knudsen, Gitte Moos; Maier-Hein, Lena

2017-01-01

With the recent trend toward big data analysis, neuroimaging datasets have grown substantially in the past years. While larger datasets potentially offer important insights for medical research, one major bottleneck is the requirement for resources of medical experts needed to validate automatic processing results. To address this issue, the goal of this paper was to assess whether anonymous nonexperts from an online community can perform quality control of MR-based cortical surface delineations derived by an automatic algorithm. So-called knowledge workers from an online crowdsourcing platform were asked to annotate errors in automatic cortical surface delineations on 100 central, coronal slices of MR images. On average, annotations for 100 images were obtained in less than an hour. When using expert annotations as reference, the crowd on average achieves a sensitivity of 82 % and a precision of 42 %. Merging multiple annotations per image significantly improves the sensitivity of the crowd (up to 95 %), but leads to a decrease in precision (as low as 22 %). Our experiments show that the detection of errors in automatic cortical surface delineations generated by anonymous untrained workers is feasible. Future work will focus on increasing the sensitivity of our method further, such that the error detection tasks can be handled exclusively by the crowd and expert resources can be focused on error correction.

Fingerprints of Sea Level Rise on Changing Tides in the Chesapeake and Delaware Bays

NASA Astrophysics Data System (ADS)

Ross, Andrew C.; Najjar, Raymond G.; Li, Ming; Lee, Serena Blyth; Zhang, Fan; Liu, Wei

2017-10-01

Secular tidal trends are present in many tide gauge records, but their causes are often unclear. This study examines trends in tides over the last century in the Chesapeake and Delaware Bays. Statistical models show negative M2 amplitude trends at the mouths of both bays, while some upstream locations have insignificant or positive trends. To determine whether sea level rise is responsible for these trends, we include a term for mean sea level in the statistical models and compare the results with predictions from numerical and analytical models. The observed and predicted sensitivities of M2 amplitude and phase to mean sea level are similar, although the numerical model amplitude is less sensitive to sea level. The sensitivity occurs as a result of strengthening and shifting of the amphidromic system in the Chesapeake Bay and decreasing frictional effects and increasing convergence in the Delaware Bay. After accounting for the effect of sea level, significant negative background M2 and S2 amplitude trends are present; these trends may be related to other factors such as dredging, tide gauge errors, or river discharge. Projected changes in tidal amplitudes due to sea level rise over the 21st century are substantial in some areas, but depend significantly on modeling assumptions.

Impact of UV-B exposure on amphibian embryos: linking species physiology and oviposition behaviour

PubMed Central

Palen, Wendy J; Williamson, Craig E; Clauser, Aaron A; Schindler, Daniel E

2005-01-01

Increasing ultraviolet-B radiation (UV-B) has recently captured the attention of ecologists as a key environmental stressor. Certain species may be particularly vulnerable as a result of either high natural exposure to UV-B or limited physiological capacity to withstand it. UV-B sensitivity has been examined at the cellular and individual level for a wide variety of taxa, but estimates of exposure to UV-B in natural systems are lacking and predictions of large-scale impacts are therefore limited. Here, we combine data on the physiological sensitivity to UV-B and patterns of field exposure across sites for embryos of several well-studied US Pacific Northwest amphibian species. We find substantial differences among species' physiological abilities to withstand UV-B and in the level of UV-B exposure of embryos in the field. More specifically, we find that species with the highest physiological sensitivity to UV-B are those with the lowest field exposures as a function of the location of embryos and the UV-B attenuation properties of water at each site. These results also suggest that conclusions made about species' vulnerability to UV-B in the absence of information on field exposures may often be misleading. PMID:16024386

Contact allergy to ingredients of hair cosmetics - a comparison of female hairdressers and clients based on IVDK 2007-2012 data.

PubMed

Uter, Wolfgang; Gefeller, Olaf; John, Swen Malte; Schnuch, Axel; Geier, Johannes

2014-07-01

Cosmetics for bleaching, waving/relaxing and dyeing hair contain well-known allergens, leading to a substantial number of cases of allergic contact dermatitis. To compare the frequency of important contact allergens (i) between two distinct groups of exposed patients, and (ii) with previous surveillance data. On the basis of data collected by the Information Network of Departments of Dermatology (IVDK; www.ivkd.org) between 2007 and 2012 in 824 female hairdressers and 2067 female clients, the current spectrum of contact sensitization to ingredients of hair cosmetics, as contained in different pertinent series, is described. A similar burden of sensitization as in previous analyses was observed, but with some increase in sensitization to oxidative hair dye components in clients. Some allergens mainly affected hairdressers, such as ammonium persulfate (18.7% positive) and glyceryl monothioglycolate (GMTG; still 4.7% positive, with a few cases also in young hairdressers, despite removal from the German market). Hair dyes remain important contact allergens, despite various attempts by the cosmetic industry to introduce hair dyes with lower allergenic potential. The re-emergence of GMTG as an occupational allergen should be considered as a warning signal ('sentinel event') prompting close monitoring. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Bright long-lived luminescence of silicon nanocrystals sensitized by two-photon absorbing antenna

PubMed Central

Ravotto, Luca; Chen, Qi; Ma, Yuguo; Vinogradov, Sergei A.; Locritani, Mirko; Bergamini, Giacomo; Negri, Fabrizia; Yu, Yixuan; Korgel, Brian A.; Ceroni, Paola

2017-01-01

Summary Silicon nanocrystals of the average diameter of 5 nm, functionalized with 4,7-di(2-thienyl)-2,1,3-benzothiadiazole chromophores (TBT) and dodecyl chains, exhibit near-infrared emission upon one-photon (1P) excitation at 515 nm and two-photon (2P) excitation at 960 nm. By using TBT chromophores as an antenna we were able to enhance both 1P and 2P absorption cross-sections of the silicon nanocrystals to more efficiently excite their long-lived luminescence. These results chart a path to two-photon-excitable imaging probes with long-lived oxygen-independent luminescence - a rare combination of properties that should allow for a substantial increase in imaging contrast. PMID:28966989

Aircraft noise, health, and residential sorting: evidence from two quasi-experiments.

PubMed

Boes, Stefan; Nüesch, Stephan; Stillman, Steven

2013-09-01

We explore two unexpected changes in flight regulations to estimate the causal effect of aircraft noise on health. Detailed measures of noise are linked with longitudinal data on individual health outcomes based on the exact address information. Controlling for individual heterogeneity and spatial sorting into different neighborhoods, we find that aircraft noise significantly increases sleeping problems and headaches. Models that do not control for such heterogeneity and sorting substantially underestimate the negative health effects, which suggests that individuals self-select into residence based on their unobserved sensitivity to noise. Our study demonstrates that the combination of quasi-experimental variation and panel data is very powerful for identifying causal effects in epidemiological field studies. Copyright © 2013 John Wiley & Sons, Ltd.

Evidence that two alkyl ester quaternary ammonium compounds lack substantial human skin-sensitizing potential.

PubMed

Jowsey, Ian R; Kligman, Albert M; White, Ian R; Goossens, An; Basketter, David A

2007-03-01

Alkyl ester quaternary ammonium compounds (ester quats) are used extensively in fabric rinse conditioners. It is important to document in the literature the outcome of historical studies that were performed to assess the risk of adverse skin effects associated with their use. (1) To document the outcomes of historical studies performed to evaluate the skin sensitizing potential of two ester quats (the di-[hardened tallow fatty acid] ester of 2,3-dihydroxypropyl-trimethyl ammonium chloride [HEQ] and the dialkyl ester of triethanol ammonium methyl sulfate [TEA-Quat]) and (2) to demonstrate that these ester quats lack marked skin-sensitizing potential in humans, such that they do not present a risk of contact allergy for consumers who use fabric rinse conditioners. Each material was assessed in the human maximization test in a panel of 25 volunteers. Diagnostic patch testing was also performed with each material in a population of 239 patients undergoing routine patch testing for suspected allergic contact dermatitis. These data are also considered in the context of an exposure-based quantitative risk assessment. Neither HEQ nor TEA-Quat was found to cause skin sensitization under the conditions of the human maximization test. No evidence of contact allergy to the materials was found among the relatively small population assessed by diagnostic patch testing. This study provides evidence that HEQ and TEA-Quat lack substantial skin-sensitizing potential in humans. Taken together with similar data for other ester quats, it suggests that compounds in this class are unlikely to be significant human contact allergens.

Prostate cancer localization with multispectral MRI using cost-sensitive support vector machines and conditional random fields.

PubMed

Artan, Yusuf; Haider, Masoom A; Langer, Deanna L; van der Kwast, Theodorus H; Evans, Andrew J; Yang, Yongyi; Wernick, Miles N; Trachtenberg, John; Yetik, Imam Samil

2010-09-01

Prostate cancer is a leading cause of cancer death for men in the United States. Fortunately, the survival rate for early diagnosed patients is relatively high. Therefore, in vivo imaging plays an important role for the detection and treatment of the disease. Accurate prostate cancer localization with noninvasive imaging can be used to guide biopsy, radiotherapy, and surgery as well as to monitor disease progression. Magnetic resonance imaging (MRI) performed with an endorectal coil provides higher prostate cancer localization accuracy, when compared to transrectal ultrasound (TRUS). However, in general, a single type of MRI is not sufficient for reliable tumor localization. As an alternative, multispectral MRI, i.e., the use of multiple MRI-derived datasets, has emerged as a promising noninvasive imaging technique for the localization of prostate cancer; however almost all studies are with human readers. There is a significant inter and intraobserver variability for human readers, and it is substantially difficult for humans to analyze the large dataset of multispectral MRI. To solve these problems, this study presents an automated localization method using cost-sensitive support vector machines (SVMs) and shows that this method results in improved localization accuracy than classical SVM. Additionally, we develop a new segmentation method by combining conditional random fields (CRF) with a cost-sensitive framework and show that our method further improves cost-sensitive SVM results by incorporating spatial information. We test SVM, cost-sensitive SVM, and the proposed cost-sensitive CRF on multispectral MRI datasets acquired from 21 biopsy-confirmed cancer patients. Our results show that multispectral MRI helps to increase the accuracy of prostate cancer localization when compared to single MR images; and that using advanced methods such as cost-sensitive SVM as well as the proposed cost-sensitive CRF can boost the performance significantly when compared to SVM.

Gravity as a probe for understanding pattern specification

NASA Technical Reports Server (NTRS)

Malacinski, George M.; Neff, Anton W.

1993-01-01

Amphibian eggs from Xenopus laevis were employed as a model system. Xenopus embryos were demonstrated to be sensitive to novel force fields. Under clinostat-simulated weightlessness the location of the third cleavage furrow was shifted towards the equator; the dorsal lip was shifted closer to the vegetal pole; and head and eye dimensions of hatching tadpoles were enlarged. Effects of centrifuge-simulated hypergravity were the opposite of those of simulated weightlessness. Those morphological alterations had their own force-sensitive period, and a substantial spawning-to-spawning variation in sensitivity was observed. Despite those dramatic differences in embryogenesis, tadpoles at the feeding stage were largely indistinguishable from controls.

Exploring the potential of short-baseline physics at Fermilab

NASA Astrophysics Data System (ADS)

Miranda, O. G.; Pasquini, Pedro; Tórtola, M.; Valle, J. W. F.

2018-05-01

We study the capabilities of the short-baseline neutrino program at Fermilab to probe the unitarity of the lepton mixing matrix. We find the sensitivity to be slightly better than the current one. Motivated by the future DUNE experiment, we have also analyzed the potential of an extra liquid Argon near detector in the LBNF beamline. Adding such a near detector to the DUNE setup will substantially improve the current sensitivity on nonunitarity. This would help to remove C P degeneracies due to the new complex phase present in the neutrino mixing matrix. We also study the sensitivity of our proposed setup to light sterile neutrinos for various configurations.

Gravity as a probe for understanding pattern specification

NASA Astrophysics Data System (ADS)

Malacinski, George M.; Neff, Anton W.

1993-08-01

Amphibian eggs from Xenopus laevis were employed as a model system. Xenopus embryos were demonstrated to be sensitive to novel force fields. Under clinostat-simulated weightlessness the location of the third cleavage furrow was shifted towards the equator; the dorsal lip was shifted closer to the vegetal pole; and head and eye dimensions of hatching tadpoles were enlarged. Effects of centrifuge-simulated hypergravity were the opposite of those of simulated weightlessness. Those morphological alterations had their own force-sensitive period, and a substantial spawning-to-spawning variation in sensitivity was observed. Despite those dramatic differences in embryogenesis, tadpoles at the feeding stage were largely indistinguishable from controls.

Sensitivity of Climate to Changes in NDVI

NASA Technical Reports Server (NTRS)

Bounoua, L.; Collatz, G. J.; Los, S. O.; Sellers, P. J.; Dazlich, D. A.; Tucker, C. J.; Randall, D. A.

1999-01-01

The sensitivity of global and regional climate to changes in vegetation density is investigated using a coupled biosphere-atmosphere model. The magnitude of the vegetation changes and their spatial distribution are based on natural decadal variability of the normalized difference vegetation index (ndvi). Different scenarios using maximum and minimum vegetation cover were derived from satellite records spanning the period 1982-1990. Albedo decreased in the northern latitudes and increased in the tropics with increased ndvi. The increase in vegetation density revealed that the vegetation's physiological response was constrained by the limits of the available water resources. The difference between the maximum and minimum vegetation scenarios resulted in a 46% increase in absorbed visible solar radiation and a similar increase in gross photosynthetic C02 uptake on a global annual basis. This caused the canopy transpiration and interception fluxes to increase, and reduced those from the soil. The redistribution of the surface energy fluxes substantially reduced the Bowen ratio during the growing season, resulting in cooler and moister near-surface climate, except when soil moisture was limiting. Important effects of increased vegetation on climate are : (1) A cooling of about 1.8 K in the northern latitudes during the growing season and a slight warming during the winter, which is primarily due to the masking of high albedo of snow by a denser canopy. and (2) A year round cooling of 0.8 K in the tropics. These results suggest that increases in vegetation density could partially compensate for parallel increases in greenhouse warming . Increasing vegetation density globally caused both evapotranspiration and precipitation to increase. Evapotranspiration, however increased more than precipitation resulting in a global soil-water deficit of about 15 %. A spectral analysis on the simulated results showed that changes in the state of vegetation could affect the low-frequency modes of the precipitation distribution and might reduce its low frequency variability in the tropics while increasing it in northern latitudes.

Snowpack sensitivity to perturbed climate changes in alpine catchements

USDA-ARS?s Scientific Manuscript database

There is great interest in ascertaining the degree of climate change necessary to induce substantial changes in snow accumulation and ablation processes in mountain headwater catchments. Therefore, the response of mountain snow hydrology to changes in air temperature and precipitation was examined ...

Rejection Sensitivity, Jealousy, and the Relationship to Interpersonal Aggression.

PubMed

Murphy, Anna M; Russell, Gemma

2018-07-01

The development and maintenance of interpersonal relationships lead individuals to risk rejection in the pursuit of acceptance. Some individuals are predisposed to experience a hypersensitivity to rejection that is hypothesized to be related to jealous and aggressive reactions within interpersonal relationships. The current study used convenience sampling to recruit 247 young adults to evaluate the relationship between rejection sensitivity, jealousy, and aggression. A mediation model was used to test three hypotheses: Higher scores of rejection sensitivity would be positively correlated to higher scores of aggression (Hypothesis 1); higher scores of rejection sensitivity would be positively correlated to higher scores of jealousy (Hypothesis 2); jealousy would mediate the relationship between rejection sensitivity and aggression (Hypothesis 3). Study results suggest a tendency for individuals with high rejection sensitivity to experience higher levels of jealousy, and subsequently have a greater propensity for aggression, than individuals with low rejection sensitivity. Future research that substantiates a link between hypersensitivity to rejection, jealousy, and aggression may provide an avenue for prevention, education, or intervention in reducing aggression within interpersonal relationships.

Thermophysical properties and rheological behavior of electro-rheological fluids at different temperatures

NASA Astrophysics Data System (ADS)

Korobko, Evguenia V.; Korobko, Yulia O.

2000-04-01

Fluid disperse systems, sensitive to the external electric field-electrorheological fluids, are finding increasing use in various areas of industry and technology. Their physicomechanical, electrophysical characteristics determine the valuable specific properties of the materials with assigned structure, obtainable with everwide use of electric fields, which makes it possible to substantially enhance efficiency and productiveness of technological processes and to improve the control of operational regimes of the equipment which employ fluid disperse media. The present investigations has been undertaken with the aim of studying thermophysical properties and rheophysical behavior of low-concentration ER- fluid (diatomite in transformer oil) at different temperatures. It was shown that the electric field, which changes considerably the structure of electrorheological fluid, influences effective thermal conductivity and diffusivity coefficients. Their increase with electric field intensity and the increase of the effective viscosity with temperature are connected with the increase of the conductive component of the overall heat transfer through the contact spots between the solid particles, and with intensification of electric convection in the spaces between the dispersed particles.

The increased incidence of pure red cell aplasia with an Eprex formulation in uncoated rubber stopper syringes.

PubMed

Boven, Katia; Stryker, Scott; Knight, John; Thomas, Adrian; van Regenmortel, Marc; Kemeny, David M; Power, David; Rossert, Jerome; Casadevall, Nicole

2005-06-01

The incidence of pure red cell aplasia (PRCA) in chronic kidney disease patients treated with epoetins increased substantially in 1998, was shown to be antibody mediated, and was associated predominantly with subcutaneous administration of Eprex. A technical investigation identified organic compounds leached from uncoated rubber stoppers in prefilled syringes containing polysorbate 80 as the most probable cause of the increased immunogenicity. This study investigated whether the incidence of PRCA was higher for exposure to the product form containing leachates than for leachate-free product forms. Antibody-mediated PRCA cases were classified according to indication, product form, and route of administration. Exposure estimates were obtained by country, indication, route of administration, and product form. For 2001 to 2003, the PRCA incidence rate for patients with subcutaneous exposure to Eprex in prefilled syringes with polysorbate 80 and uncoated rubber stoppers (leachates present) was 4.61/10,000 patient years (95% CI 3.88-5.43) versus 0.26/10,000 patient years (95% CI 0.007-1.44) for syringes with coated stoppers (leachates absent). The rate difference was 4.35/10,000 patient years (95% CI 3.44-5.26; P < 0.0001); the rate ratio was 17 (95% CI 3.14-707). A substantial rate difference remained in sensitivity analyses that adjusted for exposure to multiple product forms. The epidemiologic data, together with the chemical and immunologic data, support the hypothesis that leachates from uncoated rubber syringe stoppers caused the increased incidence of PRCA associated with Eprex. Currently, all Eprex prefilled syringes contain fluoro-resin coated stoppers, which has contributed to decreased incidence of PRCA with continued surveillance.

Surface tension prevails over solute effect in organic-influenced cloud droplet activation.

PubMed

Ovadnevaite, Jurgita; Zuend, Andreas; Laaksonen, Ari; Sanchez, Kevin J; Roberts, Greg; Ceburnis, Darius; Decesari, Stefano; Rinaldi, Matteo; Hodas, Natasha; Facchini, Maria Cristina; Seinfeld, John H; O' Dowd, Colin

2017-06-29

The spontaneous growth of cloud condensation nuclei (CCN) into cloud droplets under supersaturated water vapour conditions is described by classic Köhler theory. This spontaneous activation of CCN depends on the interplay between the Raoult effect, whereby activation potential increases with decreasing water activity or increasing solute concentration, and the Kelvin effect, whereby activation potential decreases with decreasing droplet size or increases with decreasing surface tension, which is sensitive to surfactants. Surface tension lowering caused by organic surfactants, which diminishes the Kelvin effect, is expected to be negated by a concomitant reduction in the Raoult effect, driven by the displacement of surfactant molecules from the droplet bulk to the droplet-vapour interface. Here we present observational and theoretical evidence illustrating that, in ambient air, surface tension lowering can prevail over the reduction in the Raoult effect, leading to substantial increases in cloud droplet concentrations. We suggest that consideration of liquid-liquid phase separation, leading to complete or partial engulfing of a hygroscopic particle core by a hydrophobic organic-rich phase, can explain the lack of concomitant reduction of the Raoult effect, while maintaining substantial lowering of surface tension, even for partial surface coverage. Apart from the importance of particle size and composition in droplet activation, we show by observation and modelling that incorporation of phase-separation effects into activation thermodynamics can lead to a CCN number concentration that is up to ten times what is predicted by climate models, changing the properties of clouds. An adequate representation of the CCN activation process is essential to the prediction of clouds in climate models, and given the effect of clouds on the Earth's energy balance, improved prediction of aerosol-cloud-climate interactions is likely to result in improved assessments of future climate change.

Time Trends in Pulmonary Embolism in the United States: Evidence of Overdiagnosis

PubMed Central

Wiener, Renda Soylemez; Schwartz, Lisa M.; Woloshin, Steven

2011-01-01

Background Computed tomography pulmonary angiography (CTPA) may improve detection of life-threatening pulmonary embolism. But this sensitive test may have a downside: overdiagnosis and overtreatment (finding clinically unimportant emboli and exposing patients to harms from unnecessary treatment). Methods To assess the impact of CTPA on national pulmonary embolism incidence, mortality, and treatment complications, we conducted a time trend analysis using the Nationwide Inpatient Sample and Multiple Cause-of-Death databases. We compared age-adjusted incidence, mortality, and treatment complications (in-hospital gastrointestinal or intracranial hemorrhage or secondary thrombocytopenia) of pulmonary embolism among United States adults before (1993–1998) and after (1998–2006) CTPA was introduced. Results Pulmonary embolism incidence was unchanged before CTPA (p=0.63), but increased substantially after CTPA (81% increase: from 62.1 to 112.3 per 100,000, p<0.001). Pulmonary embolism mortality decreased during both periods: more so before CTPA (8% reduction: from 13.4 to 12.3 per 100,000, p<0.001) than after (3% reduction: from 12.3 to 11.9 per 100,000, p=0.02). Case-fatality improved slightly before (8% decrease, from 13.2% to 12.1%, p=0.02) and substantially after CTPA (36% decrease: from 12.1% to 7.8%, p<0.001). Meanwhile, CTPA was associated with an increase in presumed complications of anticoagulation for pulmonary embolism: pre-CTPA, the complication rate was stable (p=0.24), but post-CTPA it increased by 71% (from 3.1 to 5.3 per 100,000, p<0.001). Conclusions The introduction of CTPA was associated with changes consistent with overdiagnosis: rising incidence, minimal change in mortality, and lower case-fatality. Better technology allows us to diagnose more emboli, but to minimize harms of overdiagnosis we must learn which ones matter. PMID:21555660

Time trends in pulmonary embolism in the United States: evidence of overdiagnosis.

PubMed

Wiener, Renda Soylemez; Schwartz, Lisa M; Woloshin, Steven

2011-05-09

Computed tomographic pulmonary angiography (CTPA) may improve detection of life-threatening pulmonary embolism (PE), but this sensitive test may have a downside: overdiagnosis and overtreatment (finding clinically unimportant emboli and exposing patients to harms from unnecessary treatment). To assess the impact of CTPA on national PE incidence, mortality, and treatment complications, we conducted a time trend analysis using the Nationwide Inpatient Sample and Multiple Cause-of-Death databases. We compared age-adjusted incidence, mortality, and treatment complications (in-hospital gastrointestinal tract or intracranial hemorrhage or secondary thrombocytopenia) of PE among US adults before (1993-1998) and after (1998-2006) CTPA was introduced. Pulmonary embolism incidence was unchanged before CTPA (P = .64) but increased substantially after CTPA (81% increase, from 62.1 to 112.3 per 100,000; P < .001). Pulmonary embolism mortality decreased during both periods: more so before CTPA (8% reduction, from 13.4 to 12.3 per 100,000; P < .001) than after (3% reduction, from 12.3 to 11.9 per 100,000; P = .02). Case fatality improved slightly before (8% decrease, from 13.2% to 12.1%; P = .02) and substantially after CTPA (36% decrease, from 12.1% to 7.8%; P < .001). Meanwhile, CTPA was associated with an increase in presumed complications of anticoagulation for PE: before CTPA, the complication rate was stable (P = .24), but after it increased by 71% (from 3.1 to 5.3 per 100,000; P < .001). The introduction of CTPA was associated with changes consistent with overdiagnosis: rising incidence, minimal change in mortality, and lower case fatality. Better technology allows us to diagnose more emboli, but to minimize harms of overdiagnosis we must learn which ones matter.

Characterization of non-CG genomic hypomethylation associated with gamma-ray-induced suppression of CMT3 transcription in Arabidopsis thaliana.

PubMed

Kim, Ji Eun; Lee, Min Hee; Cho, Eun Ju; Kim, Ji Hong; Chung, Byung Yeoup; Kim, Jin-Hong

2013-12-01

Ionizing radiation causes various epigenetic changes, as well as a variety of DNA lesions such as strand breaks, cross-links, oxidative damages, etc., in genomes. However, radiation-induced epigenetic changes have rarely been substantiated in plant genomes. The current study investigates whether DNA methylation of Arabidopsis thaliana genome is altered by gamma rays. We found that genomic DNA methylation decreased in wild-type plants with increasing doses of gamma rays (5, 50 and 200 Gy). Irradiation with 200 Gy significantly increased the expression of transcriptionally inactive centromeric 180-bp (CEN) and transcriptionally silent information (TSI) repeats. This increase suggested that there was a substantial release of transcriptional gene silencing by gamma rays, probably by induction of DNA hypomethylation. High expression of the DNA demethylase ROS1 and low expression of the DNA methyltransferase CMT3 supported this hypothesis. Moreover, Southern blot analysis following digestion of genomic DNA with methylation-sensitive enzymes revealed that the DNA hypomethylation occured preferentially at CHG or CHH sites rather than CG sites, depending on the radiation dose. Unlike CEN and TSI repeats, the number of Ta3, AtSN1 and FWA repeats decreased in transcription but increased in non-CG methylation. In addition, the cmt3-11 mutant showed neither DNA hypomethylation nor transcriptional activation of silenced repeats upon gamma irradiation. Furthermore, profiles of genome-wide transcriptomes in response to gamma rays differed between the wild-type and cmt3-11 mutant. These results suggest that gamma irradiation induced DNA hypomethylation preferentially at non-CG sites of transcriptionally inactive repeats in a locus-specific manner, which depends on CMT3 activity.

Head-to-head comparison of adaptive statistical and model-based iterative reconstruction algorithms for submillisievert coronary CT angiography.

PubMed

Benz, Dominik C; Fuchs, Tobias A; Gräni, Christoph; Studer Bruengger, Annina A; Clerc, Olivier F; Mikulicic, Fran; Messerli, Michael; Stehli, Julia; Possner, Mathias; Pazhenkottil, Aju P; Gaemperli, Oliver; Kaufmann, Philipp A; Buechel, Ronny R

2018-02-01

Iterative reconstruction (IR) algorithms allow for a significant reduction in radiation dose of coronary computed tomography angiography (CCTA). We performed a head-to-head comparison of adaptive statistical IR (ASiR) and model-based IR (MBIR) algorithms to assess their impact on quantitative image parameters and diagnostic accuracy for submillisievert CCTA. CCTA datasets of 91 patients were reconstructed using filtered back projection (FBP), increasing contributions of ASiR (20, 40, 60, 80, and 100%), and MBIR. Signal and noise were measured in the aortic root to calculate signal-to-noise ratio (SNR). In a subgroup of 36 patients, diagnostic accuracy of ASiR 40%, ASiR 100%, and MBIR for diagnosis of coronary artery disease (CAD) was compared with invasive coronary angiography. Median radiation dose was 0.21 mSv for CCTA. While increasing levels of ASiR gradually reduced image noise compared with FBP (up to - 48%, P < 0.001), MBIR provided largest noise reduction (-79% compared with FBP) outperforming ASiR (-59% compared with ASiR 100%; P < 0.001). Increased noise and lower SNR with ASiR 40% and ASiR 100% resulted in substantially lower diagnostic accuracy to detect CAD as diagnosed by invasive coronary angiography compared with MBIR: sensitivity and specificity were 100 and 37%, 100 and 57%, and 100 and 74% for ASiR 40%, ASiR 100%, and MBIR, respectively. MBIR offers substantial noise reduction with increased SNR, paving the way for implementation of submillisievert CCTA protocols in clinical routine. In contrast, inferior noise reduction by ASiR negatively affects diagnostic accuracy of submillisievert CCTA for CAD detection. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Assessment of genotoxicity associated with hydroxyurea therapy in children with sickle cell anemia

PubMed Central

Flanagan, Jonathan M.; Howard, Thad A.; Mortier, Nicole; Avlasevich, Svetlana L.; Smeltzer, Matthew P.; Wu, Song; Dertinger, Stephen D.; Ware, Russell E.

2018-01-01

Hydroxyurea induces fetal hemoglobin, improves laboratory parameters, and ameliorates clinical complications of sickle cell anemia (SCA), but its long-term efficacy and safety in this patient population remain incompletely defined. Although generally considered non-DNA reactive, an important safety concern is that hydroxyurea may indirectly cause genotoxic damage. To better address this safety issue of hydroxyurea in patients with SCA, we measured the production of micronuclei (MN) in red blood cells (RBC) as a marker of genotoxicity. Blood samples were collected from children with SCA enrolled in the Hydroxyurea Study of Long-term Effects (ClinicalTrials.gov NCT00305175). Flow cytometry quantified circulating MN-containing erythrocyte sub-populations before and during hydroxyurea exposure. The frequency of micronucleated reticulocytes (MN-CD71+) and micronucleated mature erythrocytes (MN-RBC) were then tested for associations with laboratory and clinical data. In cross-sectional analysis of 293 blood samples from 105 children with SCA and a median of 2 years of hydroxyurea therapy, exposure to hydroxyurea was associated with significantly increased frequencies of MN-CD71+ and MN-RBC compared to baseline. The increases were evident by 3 months of therapy, and did not escalate further with up to 12 years of continuous drug exposure. In prospective longitudinal analysis, substantial inter-individual variation in the effect of hydroxyurea on %MN-CD71+ was observed that was associated with the expected laboratory effects of hydroxyurea. In conclusion, clinically relevant exposure to hydroxyurea is associated with increased MN production consistent with erythroblast genotoxicity but with substantial inter-patient variability. Associations between increased %MN-CD71+ and laboratory benefits suggest that hydroxyurea effects on MN production may be related to individual patient sensitivity to hydroxyurea within the bone marrow. PMID:20230905

Improved Efficiency and Robustness in qPCR and Multiplex End-Point PCR by Twisted Intercalating Nucleic Acid Modified Primers

PubMed Central

Schneider, Uffe Vest; Mikkelsen, Nikolaj Dam; Lindqvist, Anja; Okkels, Limei Meng; Jøhnk, Nina; Lisby, Gorm

2012-01-01

We introduce quantitative polymerase chain reaction (qPCR) primers and multiplex end-point PCR primers modified by the addition of a single ortho-Twisted Intercalating Nucleic Acid (o-TINA) molecule at the 5′-end. In qPCR, the 5′-o-TINA modified primers allow for a qPCR efficiency of 100% at significantly stressed reaction conditions, increasing the robustness of qPCR assays compared to unmodified primers. In samples spiked with genomic DNA, 5′-o-TINA modified primers improve the robustness by increased sensitivity and specificity compared to unmodified DNA primers. In unspiked samples, replacement of unmodified DNA primers with 5′-o-TINA modified primers permits an increased qPCR stringency. Compared to unmodified DNA primers, this allows for a qPCR efficiency of 100% at lowered primer concentrations and at increased annealing temperatures with unaltered cross-reactivity for primers with single nucleobase mismatches. In a previously published octaplex end-point PCR targeting diarrheagenic Escherichia coli, application of 5′-o-TINA modified primers allows for a further reduction (>45% or approximately one hour) in overall PCR program length, while sustaining the amplification and analytical sensitivity for all targets in crude bacterial lysates. For all crude bacterial lysates, 5′-o-TINA modified primers permit a substantial increase in PCR stringency in terms of lower primer concentrations and higher annealing temperatures for all eight targets. Additionally, crude bacterial lysates spiked with human genomic DNA show lesser formation of non-target amplicons implying increased robustness. Thus, 5′-o-TINA modified primers are advantageous in PCR assays, where one or more primer pairs are required to perform at stressed reaction conditions. PMID:22701644

How Has Human-induced Climate Change Affected California Drought Risk?

NASA Astrophysics Data System (ADS)

Cheng, L.; Hoerling, M. P.; Aghakouchak, A.; Livneh, B.; Quan, X. W.; Eischeid, J. K.

2015-12-01

The current California drought has cast a heavy burden on statewide agriculture and water resources, further exacerbated by concurrent extreme high temperatures. Furthermore, industrial-era global radiative forcing brings into question the role of long-term climate change on CA drought. How has human-induced climate change affected California drought risk? Here, observations and model experimentation are applied to characterize this drought employing metrics that synthesize drought duration, cumulative precipitation deficit, and soil moisture depletion. The model simulations show that increases in radiative forcing since the late 19th Century induces both increased annual precipitation and increased surface temperature over California, consistent with prior model studies and with observed long-term change. As a result, there is no material difference in the frequency of droughts defined using bivariate indicators of precipitation and near-surface (10-cm) soil moisture, because shallow soil moisture responds most sensitively to increased evaporation driven by warming, which compensates the increase in the precipitation. However, when using soil moisture within a deep root zone layer (1-m) as co-variate, droughts become less frequent because deep soil moisture responds most sensitively to increased precipitation. The results illustrate the different land surface responses to anthropogenic forcing that are relevant for near-surface moisture exchange and for root zone moisture availability. The latter is especially relevant for agricultural impacts as the deep layer dictates moisture availability for plants, trees, and many crops. The results thus indicate the net effect of climate change has made agricultural drought less likely, and that the current severe impacts of drought on California's agriculture has not been substantially caused by long-term climate changes.

SST Patterns, Atmospheric Variability, and Inferred Sensitivities in the CMIP5 Model Archive

NASA Astrophysics Data System (ADS)

Marvel, K.; Pincus, R.; Schmidt, G. A.

2017-12-01

An emerging consensus suggests that global mean feedbacks to increasing temperature are not constant in time. If feedbacks become more positive in the future, the equilibrium climate sensitivity (ECS) inferred from recent observed global energy budget constraints is likely to be biased low. Time-varying feedbacks are largely tied to evolving sea-surface temperature patterns. In particular, recent anomalously cool conditions in the tropical Pacific may have triggered feedbacks that are not reproduced in equilibrium simulations where the tropical Pacific and Southern Ocean have had time to warm. Here, we use AMIP and CMIP5 historical simulations to explore the ECS that may be inferred over the recent historical period. We find that in all but one CMIP5 model, the feedbacks triggered by observed SST patterns are significantly less positive than those arising from historical simulations in which SST patterns are allowed to evolve unconstrained. However, there are substantial variations in feedbacks even when the SST pattern is held fixed, suggesting that atmospheric and land variability contribute to uncertainty in the estimates of ECS obtained from recent observations of the global energy budget.

CMIP5 models' shortwave cloud radiative response and climate sensitivity linked to the climatological Hadley cell extent

NASA Astrophysics Data System (ADS)

Lipat, Bernard R.; Tselioudis, George; Grise, Kevin M.; Polvani, Lorenzo M.

2017-06-01

This study analyzes Coupled Model Intercomparison Project phase 5 (CMIP5) model output to examine the covariability of interannual Southern Hemisphere Hadley cell (HC) edge latitude shifts and shortwave cloud radiative effect (SWCRE). In control climate runs, during years when the HC edge is anomalously poleward, most models substantially reduce the shortwave radiation reflected by clouds in the lower midlatitude region (LML; ˜28°S-˜48°S), although no such reduction is seen in observations. These biases in HC-SWCRE covariability are linked to biases in the climatological HC extent. Notably, models with excessively equatorward climatological HC extents have weaker climatological LML subsidence and exhibit larger increases in LML subsidence with poleward HC edge expansion. This behavior, based on control climate interannual variability, has important implications for the CO2-forced model response. In 4×CO2-forced runs, models with excessively equatorward climatological HC extents produce stronger SW cloud radiative warming in the LML region and tend to have larger climate sensitivity values than models with more realistic climatological HC extents.

Integrating Antiretroviral Strategies for Human Immunodeficiency Virus Prevention: Post- and Pre-Exposure Prophylaxis and Early Treatment.

PubMed

Grant, Robert M; Smith, Dawn K

2015-12-01

Best practices for integrating human immunodeficiency virus (HIV) testing and antiretroviral interventions for prevention and treatment are suggested based on research evidence and existing normative guidance. The goal is to provide high-impact prevention services during periods of substantial risk. Antiretroviral medications are recommended for postexposure prophylaxis (PEP), pre-exposure prophylaxis (PrEP), and treatment of HIV infection. We reviewed research evidence and current normative guidelines to identify best practices for integrating these high-impact prevention strategies. More sensitive HIV tests used for screening enable earlier diagnosis and treatment of HIV infection, more appropriate counseling, and help limit drug resistance. A fully suppressive PEP regimen should be initiated based on exposure history or physical findings when sensitive diagnostic testing is delayed or not available and antibody tests are negative. Transitions from PEP to PrEP are often warranted because HIV exposure events may continue to occur. This algorithmic approach to integrating PEP, PrEP, and early treatment decisions may increase the uptake of these interventions by a greater number and diversity of knowledgeable healthcare providers.

Integrating Antiretroviral Strategies for Human Immunodeficiency Virus Prevention: Post- and Pre-Exposure Prophylaxis and Early Treatment

PubMed Central

Grant, Robert M.; Smith, Dawn K.

2015-01-01

Best practices for integrating human immunodeficiency virus (HIV) testing and antiretroviral interventions for prevention and treatment are suggested based on research evidence and existing normative guidance. The goal is to provide high-impact prevention services during periods of substantial risk. Antiretroviral medications are recommended for postexposure prophylaxis (PEP), pre-exposure prophylaxis (PrEP), and treatment of HIV infection. We reviewed research evidence and current normative guidelines to identify best practices for integrating these high-impact prevention strategies. More sensitive HIV tests used for screening enable earlier diagnosis and treatment of HIV infection, more appropriate counseling, and help limit drug resistance. A fully suppressive PEP regimen should be initiated based on exposure history or physical findings when sensitive diagnostic testing is delayed or not available and antibody tests are negative. Transitions from PEP to PrEP are often warranted because HIV exposure events may continue to occur. This algorithmic approach to integrating PEP, PrEP, and early treatment decisions may increase the uptake of these interventions by a greater number and diversity of knowledgeable healthcare providers. PMID:26512356

Localization of binary neutron star mergers with second and third generation gravitational-wave detectors

NASA Astrophysics Data System (ADS)

Mills, Cameron; Tiwari, Vaibhav; Fairhurst, Stephen

2018-05-01

The observation of gravitational wave signals from binary black hole and binary neutron star mergers has established the field of gravitational wave astronomy. It is expected that future networks of gravitational wave detectors will possess great potential in probing various aspects of astronomy. An important consideration for successive improvement of current detectors or establishment on new sites is knowledge of the minimum number of detectors required to perform precision astronomy. We attempt to answer this question by assessing the ability of future detector networks to detect and localize binary neutron stars mergers on the sky. Good localization ability is crucial for many of the scientific goals of gravitational wave astronomy, such as electromagnetic follow-up, measuring the properties of compact binaries throughout cosmic history, and cosmology. We find that although two detectors at improved sensitivity are sufficient to get a substantial increase in the number of observed signals, at least three detectors of comparable sensitivity are required to localize majority of the signals, typically to within around 10 deg2 —adequate for follow-up with most wide field of view optical telescopes.

Computational fluid dynamics challenges for hybrid air vehicle applications

NASA Astrophysics Data System (ADS)

Carrin, M.; Biava, M.; Steijl, R.; Barakos, G. N.; Stewart, D.

2017-06-01

This paper begins by comparing turbulence models for the prediction of hybrid air vehicle (HAV) flows. A 6 : 1 prolate spheroid is employed for validation of the computational fluid dynamics (CFD) method. An analysis of turbulent quantities is presented and the Shear Stress Transport (SST) k-ω model is compared against a k-ω Explicit Algebraic Stress model (EASM) within the unsteady Reynolds-Averaged Navier-Stokes (RANS) framework. Further comparisons involve Scale Adaptative Simulation models and a local transition transport model. The results show that the flow around the vehicle at low pitch angles is sensitive to transition effects. At high pitch angles, the vortices generated on the suction side provide substantial lift augmentation and are better resolved by EASMs. The validated CFD method is employed for the flow around a shape similar to the Airlander aircraft of Hybrid Air Vehicles Ltd. The sensitivity of the transition location to the Reynolds number is demonstrated and the role of each vehicle£s component is analyzed. It was found that the ¦ns contributed the most to increase the lift and drag.

Design and Performance of the Antenna-Coupled Lumped-Element Kinetic Inductance Detector

NASA Astrophysics Data System (ADS)

Barry, P. S.; Doyle, S.; Hornsby, A. L.; Kofman, A.; Mayer, E.; Nadolski, A.; Tang, Q. Y.; Vieira, J.; Shirokoff, E.

2018-05-01

Focal plane arrays consisting of low-noise, polarisation-sensitive detectors have made possible the pioneering advances in the study of the cosmic microwave background (CMB). To make further progress, the next generation of CMB experiments (e.g. CMB-S4) will require a substantial increase in the number of detectors compared to current instruments. Arrays of kinetic inductance detectors (KIDs) provide a possible path to realising such large-format arrays owing to their intrinsic multiplexing advantage and relative cryogenic simplicity. In this paper, we report on the design of a variant of the traditional KID design: the antenna-coupled lumped-element KID. A polarisation-sensitive twin-slot antenna placed behind an optimised hemispherical lens couples power onto a thin-film superconducting microstrip line. The power is then guided into the inductive section of an aluminium KID, where it is absorbed and modifies both the resonant frequency and quality factor of the KID. We present the various aspects of the design and preliminary results from the first set of seven-element prototype arrays and compare to the expected modelled performance.

Holographic recording properties in thick films of ULSH-500 photopolymer

NASA Astrophysics Data System (ADS)

Waldman, David A.; Li, H.-Y. S.; Cetin, Erdem A.

1998-06-01

The photopolymer holographic recording materials, ULSH-500, based upon cationic ring-opening polymerization, has been further optimized for recording in an increased film thickness of 200 micrometers . The dynamic range attained, at least M/# equals 16, is substantially greater than previously reported, while concurrently the inherent low transverse shrinkage and high sensitivity characteristics of the material have been retained. Dynamic range or cumulative grating strength, (Sigma) (eta) i0.5, has been determined from co-locationally recorded peristrophic and angle multiplexed plane-wave gratings which exhibit low diffraction efficiencies between about 0.1 and 0.2%. Good Bragg selectivity consistent with the imaged thickness and sinc2 function behavior is observed for the multiplexed holograms, and both the angular response and the diffraction efficiency are stable without the need for post-imaging fixing procedures. Sensitivity is in the range of 1 to 10 cm/mJ, and the refractive index modulation achievable during consumption of the accessible dynamic range is n1 equals 1.3 X 10-2 at the read wavelength of 514.5 nm.

Solvent signal suppression for high-resolution MAS-DNP

NASA Astrophysics Data System (ADS)

Lee, Daniel; Chaudhari, Sachin R.; De Paëpe, Gaël

2017-05-01

Dynamic nuclear polarization (DNP) has become a powerful tool to substantially increase the sensitivity of high-field magic angle spinning (MAS) solid-state NMR experiments. The addition of dissolved hyperpolarizing agents usually results in the presence of solvent signals that can overlap and obscure those of interest from the analyte. Here, two methods are proposed to suppress DNP solvent signals: a Forced Echo Dephasing experiment (FEDex) and TRAnsfer of Populations in DOuble Resonance Echo Dephasing (TRAPDORED) NMR. These methods reintroduce a heteronuclear dipolar interaction that is specific to the solvent, thereby forcing a dephasing of recoupled solvent spins and leaving acquired NMR spectra free of associated resonance overlap with the analyte. The potency of these methods is demonstrated on sample types common to MAS-DNP experiments, namely a frozen solution (of L-proline) and a powdered solid (progesterone), both containing deuterated glycerol as a DNP solvent. The proposed methods are efficient, simple to implement, compatible with other NMR experiments, and extendable past spectral editing for just DNP solvents. The sensitivity gains from MAS-DNP in conjunction with FEDex or TRAPDORED then permits rapid and uninterrupted sample analysis.

An ultrasensitive quantum dots fluorescent polarization immunoassay based on the antibody modified Au nanoparticles amplifying for the detection of adenosine triphosphate.

PubMed

He, Yanlong; Tian, Jianniao; Hu, Kun; Zhang, Juanni; Chen, Sheng; Jiang, Yixuan; Zhao, Yanchun; Zhao, Shulin

2013-11-13

In this work, an ultrasensitive fluorescent polarization immunoassay (FPIA) method based on the quantum dot/aptamer/antibody/gold nanoparticles ensemble has been developed for the detection of adenosine triphosphate (ATP). DNA hybridization is formed when ATP is present in the PBS solution containing the DNA-conjugated quantum dots (QDs) and antibody-AuNPs. The substantial sensitivity improvement of the antibody-AuNPs-enhanced method is mainly attributed to the slower rotation of fluorescent unit when QDs-labeled oligonucleotides hybridize with antibody modified the gold nanoparticle. As a result, the fluorescent polarization (FP) values of the system increase significantly. Under the optimal conditions, a linear response with ATP concentration is ranged from 8×10(-12) M to 2.40×10(-4) M. The detection limit reached as low as 1.8 pM. The developed work provides a sensitive and selective immunoassay protocol for ATP detection, which could be applied in more bioanalytical systems. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Fungal Competitors Affect Production of Antimicrobial Lipopeptides in Bacillus subtilis Strain B9-5.

PubMed

DeFilippi, Stefanie; Groulx, Emma; Megalla, Merna; Mohamed, Rowida; Avis, Tyler J

2018-04-01

Bacillus subtilis has shown success in antagonizing plant pathogens where strains of the bacterium produce antimicrobial cyclic lipopeptides (CLPs) in response to microbial competitors in their ecological niche. To gain insight into the inhibitory role of these CLPs, B. subtilis strain B9-5 was co-cultured with three pathogenic fungi. Inhibition of mycelial growth and spore germination was assessed and CLPs produced by B. subtilis B9-5 were quantified over the entire period of microbial interaction. B. subtilis B9-5 significantly inhibited mycelial growth and spore germination of Fusarium sambucinum and Verticillium dahliae, but not Rhizopus stolonifer. LC-MS analysis revealed that B. subtilis differentially produced fengycin and surfactin homologs depending on the competitor. CLP quantification suggested that the presence of Verticillium dahliae, a fungus highly sensitive to the compounds, caused an increase followed by a decrease in CLP production by the bacterium. In co-cultures with Fusarium sambucinum, a moderately sensitive fungus, CLP production increased more gradually, possibly because of its slower rate of spore germination. With co-cultures of the tolerant fungus Rhizopus stolonifer, B. subtilis produced high amounts of CLPs (per bacterial cell) for the duration of the interaction. Variations in CLP production could be explained, in part, by the pathogens' overall sensitivities to the bacterial lipopeptides and/or the relative growth rates between the plant pathogen and B. subtilis. CLP production varied substantially temporally depending on the targeted fungus, which provides valuable insight concerning the effectiveness of B. subtilis B9-5 protecting its ecological niche against the ingress of these pathogens.

Impact of atmospheric and terrestrial CO2 feedbacks on fertilization-induced marine carbon uptake

NASA Astrophysics Data System (ADS)

Oschlies, A.

2009-04-01

The sensitivity of oceanic CO2 uptake to alterations in the marine biological carbon pump, such as brought about by natural or purposeful ocean fertilization, has repeatedly been investigated by studies employing numerical biogeochemical ocean models. It is shown here that the results of such ocean-centered studies are very sensitive to the assumption made about the response of the carbon reservoirs on the atmospheric side of the sea surface. Assumptions made include prescribed atmospheric pCO2, an interactive atmospheric CO2 pool exchanging carbon with the ocean but not with the terrestrial biosphere, and an interactive atmosphere that exchanges carbon with both oceanic and terrestrial carbon pools. The impact of these assumptions on simulated annual to millennial oceanic carbon uptake is investigated for a hypothetical increase in the C:N ratio of the biological pump and for an idealized enhancement of phytoplankton growth. Compared to simulations with interactive atmosphere, using prescribed atmospheric pCO2 overestimates the sensitivity of the oceanic CO2 uptake to changes in the biological pump, by about 2%, 25%, 100%, and >500% on annual, decadal, centennial, and millennial timescales, respectively. Adding an interactive terrestrial carbon pool to the atmosphere-ocean model system has a small effect on annual timescales, but increases the simulated fertilization-induced oceanic carbon uptake by about 4%, 50%, and 100% on decadal, centennial, and millennial timescales, respectively. On longer than decadal timescales, a substantial fraction of oceanic carbon uptake induced by natural or purposeful ocean fertilization may not come from the atmosphere but from the terrestrial biosphere.

Homogenisation of cystic fibrosis sputum by sonication--an essential step for Aspergillus PCR.

PubMed

Baxter, Caroline G; Jones, Andrew M; Webb, Kevin; Denning, David W

2011-04-01

The importance of Aspergillus as a lung pathogen in cystic fibrosis (CF) is becoming increasingly recognised. However, fungal culture of CF sputum is unreliable and there is no consensus for identifying phenotypes beyond ABPA that may benefit from antifungal therapy. There are no published studies using real-time PCR to detect Aspergillus in CF sputum. The major barrier to sensitive detection of Aspergillus using PCR is sputum homogenisation. This study aimed to optimise sputum homogenisation utilising sonication to improve Aspergillus DNA extraction. Sonication amplitude and duration that enabled sputum homogenisation but ensured preservation of DNA integrity were first determined. 160 sputum samples were collected from CF patients. 49 of the sputum samples were split, one half was used for standard culture and the other half was homogenised with NALC-NaOH before undergoing DNA extraction. The subsequent 111 samples were homogenised with dithiothreitol plus sonication prior to culture and DNA extraction. Real-time PCR targeting a portion of the 18S rDNA of Aspergillus was performed on all DNA extractions. In the 49 samples with no sonication 8 (16%) were culture positive but only 4 of these were PCR positive. However, PCR was positive in 11 culture negative samples. PCR after sonication showed a significant improvement in sensitivity: 33 (30%) were culture and PCR positive, 48 (43%) were culture negative, but PCR positive (p<0.0001) and 30 (27%) were culture and PCR negative. The combination of dithiothreitol and sonication to homogenise sputum increases PCR yield, with PCR being substantially more sensitive than culture. Copyright © 2011 Elsevier B.V. All rights reserved.

Network and neuronal membrane properties in hybrid networks reciprocally regulate selectivity to rapid thalamocortical inputs.

PubMed

Pesavento, Michael J; Pinto, David J

2012-11-01

Rapidly changing environments require rapid processing from sensory inputs. Varying deflection velocities of a rodent's primary facial vibrissa cause varying temporal neuronal activity profiles within the ventral posteromedial thalamic nucleus. Local neuron populations in a single somatosensory layer 4 barrel transform sparsely coded input into a spike count based on the input's temporal profile. We investigate this transformation by creating a barrel-like hybrid network with whole cell recordings of in vitro neurons from a cortical slice preparation, embedding the biological neuron in the simulated network by presenting virtual synaptic conductances via a conductance clamp. Utilizing the hybrid network, we examine the reciprocal network properties (local excitatory and inhibitory synaptic convergence) and neuronal membrane properties (input resistance) by altering the barrel population response to diverse thalamic input. In the presence of local network input, neurons are more selective to thalamic input timing; this arises from strong feedforward inhibition. Strongly inhibitory (damping) network regimes are more selective to timing and less selective to the magnitude of input but require stronger initial input. Input selectivity relies heavily on the different membrane properties of excitatory and inhibitory neurons. When inhibitory and excitatory neurons had identical membrane properties, the sensitivity of in vitro neurons to temporal vs. magnitude features of input was substantially reduced. Increasing the mean leak conductance of the inhibitory cells decreased the network's temporal sensitivity, whereas increasing excitatory leak conductance enhanced magnitude sensitivity. Local network synapses are essential in shaping thalamic input, and differing membrane properties of functional classes reciprocally modulate this effect.

Recombinant antibodies and their use in biosensors.

PubMed

Zeng, Xiangqun; Shen, Zhihong; Mernaugh, Ray

2012-04-01

Inexpensive, noninvasive immunoassays can be used to quickly detect disease in humans. Immunoassay sensitivity and specificity are decidedly dependent upon high-affinity, antigen-specific antibodies. Antibodies are produced biologically. As such, antibody quality and suitability for use in immunoassays cannot be readily determined or controlled by human intervention. However, the process through which high-quality antibodies can be obtained has been shortened and streamlined by use of genetic engineering and recombinant antibody techniques. Antibodies that traditionally take several months or more to produce when animals are used can now be developed in a few weeks as recombinant antibodies produced in bacteria, yeast, or other cell types. Typically most immunoassays use two or more antibodies or antibody fragments to detect antigens that are indicators of disease. However, a label-free biosensor, for example, a quartz-crystal microbalance (QCM) needs one antibody only. As such, the cost and time needed to design and develop an immunoassay can be substantially reduced if recombinant antibodies and biosensors are used rather than traditional antibody and assay (e.g. enzyme-linked immunosorbant assay, ELISA) methods. Unlike traditional antibodies, recombinant antibodies can be genetically engineered to self-assemble on biosensor surfaces, at high density, and correctly oriented to enhance antigen-binding activity and to increase assay sensitivity, specificity, and stability. Additionally, biosensor surface chemistry and physical and electronic properties can be modified to further increase immunoassay performance above and beyond that obtained by use of traditional methods. This review describes some of the techniques investigators have used to develop highly specific and sensitive, recombinant antibody-based biosensors for detection of antigens in simple or complex biological samples.

CT triage for lung malignancy: coronal multiplanar reformation versus images in three orthogonal planes.

PubMed

Kusk, Martin Weber; Karstoft, Jens; Mussmann, Bo Redder

2015-11-01

Generation of multiplanar reformation (MPR) images has become automatic on most modern computed tomography (CT) scanners, potentially increasing the workload of the reporting radiologists. It is not always clear if this increases diagnostic performance in all clinical tasks. To assess detection performance using only coronal multiplanar reformations (MPR) when triaging patients for lung malignancies with CT compared to images in three orthogonal planes, and to evaluate performance comparison of novice and experienced readers. Retrospective study of 63 patients with suspicion of lung cancer, scanned on 64-slice multidetector computed tomography (MDCT) with images reconstructed in three planes. Coronal images were presented to four readers, two novice and two experienced. Readers decided whether the patients were suspicious for malignant disease, and indicated their confidence on a five-point scale. Sensitivity and specificity on per-patient basis was calculated with regards to a reference standard of histological diagnosis, and compared with the original report using McNemar's test. Receiver operating characteristic (ROC) curves were plotted to compare the performance of the four readers, using the area under the curve (AUC) as figure of merit. No statistically significant difference of sensitivity and specificity was found for any of the readers when compared to the original reports. ROC analysis yielded AUCs in the range of 0.92-0.93 for all readers with no significant difference. Inter-rater agreement was substantial (kappa = 0.72). Sensitivity and specificity were comparable to diagnosis using images in three planes. No significant difference was found between experienced and novice readers. © The Foundation Acta Radiologica 2014.

A Novel Strategy to Increase the Proliferative Potential of Adult Human β-Cells While Maintaining Their Differentiated Phenotype

PubMed Central

Aly, Haytham; Rohatgi, Nidhi; Marshall, Connie A.; Grossenheider, Tiffani C.; Miyoshi, Hiroyuki; Stappenbeck, Thaddeus S.; Matkovich, Scot J.; McDaniel, Michael L.

2013-01-01

Our previous studies demonstrated that Wnt/GSK-3/β-catenin and mTOR signaling are necessary to stimulate proliferative processes in adult human β-cells. Direct inhibition of GSK-3, that engages Wnt signaling downstream of the Wnt receptor, increases β-catenin nuclear translocation and β-cell proliferation but results in lower insulin content. Our current goal was to engage canonical and non-canonical Wnt signaling at the receptor level to significantly increase human β-cell proliferation while maintaining a β-cell phenotype in intact islets. We adopted a system that utilized conditioned medium from L cells that expressed Wnt3a, R-spondin-3 and Noggin (L-WRN conditioned medium). In addition we used a ROCK inhibitor (Y-27632) and SB-431542 (that results in RhoA inhibition) in these cultures. Treatment of intact human islets with L-WRN conditioned medium plus inhibitors significantly increased DNA synthesis ∼6 fold in a rapamycin-sensitive manner. Moreover, this treatment strikingly increased human β-cell proliferation ∼20 fold above glucose alone. Only the combination of L-WRN conditioned medium with RhoA/ROCK inhibitors resulted in substantial proliferation. Transcriptome-wide gene expression profiling demonstrated that L-WRN medium provoked robust changes in several signaling families, including enhanced β-catenin-mediated and β-cell-specific gene expression. This treatment also increased expression of Nr4a2 and Irs2 and resulted in phosphorylation of Akt. Importantly, glucose-stimulated insulin secretion and content were not downregulated by L-WRN medium treatment. Our data demonstrate that engaging Wnt signaling at the receptor level by this method leads to necessary crosstalk between multiple signaling pathways including activation of Akt, mTOR, Wnt/β-catenin, PKA/CREB, and inhibition of RhoA/ROCK that substantially increase human β-cell proliferation while maintaining the β-cell phenotype. PMID:23776620

A novel strategy to increase the proliferative potential of adult human β-cells while maintaining their differentiated phenotype.

PubMed

Aly, Haytham; Rohatgi, Nidhi; Marshall, Connie A; Grossenheider, Tiffani C; Miyoshi, Hiroyuki; Stappenbeck, Thaddeus S; Matkovich, Scot J; McDaniel, Michael L

2013-01-01

Our previous studies demonstrated that Wnt/GSK-3/β-catenin and mTOR signaling are necessary to stimulate proliferative processes in adult human β-cells. Direct inhibition of GSK-3, that engages Wnt signaling downstream of the Wnt receptor, increases β-catenin nuclear translocation and β-cell proliferation but results in lower insulin content. Our current goal was to engage canonical and non-canonical Wnt signaling at the receptor level to significantly increase human β-cell proliferation while maintaining a β-cell phenotype in intact islets. We adopted a system that utilized conditioned medium from L cells that expressed Wnt3a, R-spondin-3 and Noggin (L-WRN conditioned medium). In addition we used a ROCK inhibitor (Y-27632) and SB-431542 (that results in RhoA inhibition) in these cultures. Treatment of intact human islets with L-WRN conditioned medium plus inhibitors significantly increased DNA synthesis ∼6 fold in a rapamycin-sensitive manner. Moreover, this treatment strikingly increased human β-cell proliferation ∼20 fold above glucose alone. Only the combination of L-WRN conditioned medium with RhoA/ROCK inhibitors resulted in substantial proliferation. Transcriptome-wide gene expression profiling demonstrated that L-WRN medium provoked robust changes in several signaling families, including enhanced β-catenin-mediated and β-cell-specific gene expression. This treatment also increased expression of Nr4a2 and Irs2 and resulted in phosphorylation of Akt. Importantly, glucose-stimulated insulin secretion and content were not downregulated by L-WRN medium treatment. Our data demonstrate that engaging Wnt signaling at the receptor level by this method leads to necessary crosstalk between multiple signaling pathways including activation of Akt, mTOR, Wnt/β-catenin, PKA/CREB, and inhibition of RhoA/ROCK that substantially increase human β-cell proliferation while maintaining the β-cell phenotype.

Insulin-sensitizing effect of rosiglitazone (BRL-49653) by regulation of glucose transporters in muscle and fat of Zucker rats.

PubMed

Kramer, D; Shapiro, R; Adler, A; Bush, E; Rondinone, C M

2001-11-01

Thiazolidinediones (TZDs), a class of antidiabetic agents, are specific agonists of peroxisome proliferator activator receptor (PPARgamma). However, their mechanisms of action, and the in vivo target tissues that mediate insulin sensitization are not well understood. The aim of this study was to investigate the role of glucose transporters (GLUT-1 and GLUT-4) in the TZD insulin-sensitizer action. The effects of rosiglitazone treatment were studied using Zucker (fa/fa) rats after 7 days of oral dosing (3.6 mg/kg/d). Rosiglitazone lowered (approximate 80%) basal plasma insulin levels in obese rats and substantially corrected (approximately 50%) insulin resistance based upon results from hyperinsulinemic euglycemic clamp studies. GLUT-4 protein levels were reduced (approximately 75%) in adipose tissue of obese rats and treatment with rosiglitazone normalized them. Interestingly, GLUT-1 protein content was increased in adipose tissue ( thick approximate 150%) and skeletal muscle (approximately 50%) of obese rats and treatment with rosiglitazone increased it even more by 5.5-fold in fat and by 2.5-fold in muscle. Consistent with these results, basal (GLUT-1-mediated) transport rate of 3-O-methyl-D-glucose into isolated epitrochlearis muscle was elevated in response to rosiglitazone. Incubation of fully differentiated 3T3-L1 adipocytes with the drug for 7 days increased the levels of GLUT-1 protein, but did not affect GLUT-4 levels. In conclusion, rosiglitazone may improve insulin resistance in vivo by normalizing GLUT-4 protein content in adipose tissue and increasing GLUT-1 in skeletal muscle and fat. While the drug has a direct effect on GLUT-1 protein expression in vitro without a direct effect on GLUT-4 suggests that direct and indirect effects of rosiglitazone on glucose transporters may have an important role in improving insulin resistance in vivo. Copyright 2001 by W.B. Saunders Company

Effect of proton transfer on the electronic coupling in DNA

NASA Astrophysics Data System (ADS)

Rak, Janusz; Makowska, Joanna; Voityuk, Alexander A.

2006-06-01

The effects of single and double proton transfer within Watson-Crick base pairs on donor-acceptor electronic couplings, Vda, in DNA are studied on the bases of quantum chemical calculations. Four dimers [AT,AT], [GC,GC], [GC,AT] and [GC,TA)] are considered. Three techniques - the generalized Mulliken-Hush scheme, the fragment charge method and the diabatic states method - are employed to estimate Vda for hole transfer between base pairs. We show that both single- and double proton transfer (PT) reactions may substantially affect the electronic coupling in DNA. The electronic coupling in [AT,AT] is predicted to be most sensitive to PT. Single PT within the first base pair in the dimer leads to increase in the hole transfer efficiency by a factor of 4, while proton transfer within the second pair should substantially, by 2.7 times, decrease the rate of charge transfer. Thus, directional asymmetry of the PT effects on the electronic coupling is predicted. The changes in the Vda matrix elements correlate with the topological properties of orbitals of donor and acceptor and can be qualitatively rationalized in terms of resonance structures of donor and acceptor. Atomic pair contributions to the Vda matrix elements are also analyzed.

Sensitivity to volcanic field boundary

NASA Astrophysics Data System (ADS)

Runge, Melody; Bebbington, Mark; Cronin, Shane; Lindsay, Jan; Rashad Moufti, Mohammed

2016-04-01

Volcanic hazard analyses are desirable where there is potential for future volcanic activity to affect a proximal population. This is frequently the case for volcanic fields (regions of distributed volcanism) where low eruption rates, fertile soil, and attractive landscapes draw populations to live close by. Forecasting future activity in volcanic fields almost invariably uses spatial or spatio-temporal point processes with model selection and development based on exploratory analyses of previous eruption data. For identifiability reasons, spatio-temporal processes, and practically also spatial processes, the definition of a spatial region is required to which volcanism is confined. However, due to the complex and predominantly unknown sub-surface processes driving volcanic eruptions, definition of a region based solely on geological information is currently impossible. Thus, the current approach is to fit a shape to the known previous eruption sites. The class of boundary shape is an unavoidable subjective decision taken by the forecaster that is often overlooked during subsequent analysis of results. This study shows the substantial effect that this choice may have on even the simplest exploratory methods for hazard forecasting, illustrated using four commonly used exploratory statistical methods and two very different regions: the Auckland Volcanic Field, New Zealand, and Harrat Rahat, Kingdom of Saudi Arabia. For Harrat Rahat, sensitivity of results to boundary definition is substantial. For the Auckland Volcanic Field, the range of options resulted in similar shapes, nevertheless, some of the statistical tests still showed substantial variation in results. This work highlights the fact that when carrying out any hazard analysis on volcanic fields, it is vital to specify how the volcanic field boundary has been defined, assess the sensitivity of boundary choice, and to carry these assumptions and related uncertainties through to estimates of future activity and hazard analyses.

Plasma Membrane Cholesterol as a Regulator of Human and Rodent P2X7 Receptor Activation and Sensitization*

PubMed Central

Robinson, Lucy E.; Shridar, Mitesh; Smith, Philip; Murrell-Lagnado, Ruth D.

2014-01-01

P2X7 receptors are nonselective cation channels gated by high extracellular ATP, but with sustained activation, receptor sensitization occurs, whereby the intrinsic pore dilates, making the cell permeable to large organic cations, which eventually leads to cell death. P2X7 receptors associate with cholesterol-rich lipid rafts, but it is unclear how this affects the properties of the receptor channel. Here we show that pore-forming properties of human and rodent P2X7 receptors are sensitive to perturbations of cholesterol levels. Acute depletion of cholesterol with 5 mm methyl-β-cyclodextrin (MCD) caused a substantial increase in the rate of agonist-evoked pore formation, as measured by the uptake of ethidium dye, whereas cholesterol loading inhibited this process. Patch clamp analysis of P2X7 receptor currents carried by Na+ and N-methyl-d-glucamine (NMDG+) showed enhanced activation and current facilitation following cholesterol depletion. This contrasts with the inhibitory effect of methyl-β-cyclodextrin reported for other P2X subtypes. Mutational analysis suggests the involvement of an N-terminal region and a proximal C-terminal region that comprises multiple cholesterol recognition amino acid consensus (CRAC) motifs, in the cholesterol sensitivity of channel gating. These results reveal cholesterol as a negative regulator of P2X7 receptor pore formation, protecting cells from P2X7-mediated cell death. PMID:25281740

Adipokine zinc-α2-glycoprotein regulated by growth hormone and linked to insulin sensitivity.

PubMed

Balaz, Miroslav; Ukropcova, Barbara; Kurdiova, Timea; Gajdosechova, Lucia; Vlcek, Miroslav; Janakova, Zuzana; Fedeles, Jozef; Pura, Mikulas; Gasperikova, Daniela; Smith, Steven R; Tkacova, Ruzena; Klimes, Iwar; Payer, Juraj; Wolfrum, Christian; Ukropec, Jozef

2015-02-01

Hypertrophic obesity is associated with impaired insulin sensitivity and lipid-mobilizing activity of zinc-α2-glycoprotein. Adipose tissue (AT) of growth hormone (GH) -deficient patients is characterized by extreme adipocyte hypertrophy due to defects in AT lipid metabolism. It was hypothesized that zinc-α2-glycoprotein is regulated by GH and mediates some of its beneficial effects in AT. AT from patients with GH deficiency and individuals with obesity-related GH deficit was obtained before and after 5-year and 24-month GH supplementation therapy. GH action was tested in primary human adipocytes. Relationships of GH and zinc-α2-glycoprotein with adipocyte size and insulin sensitivity were evaluated in nondiabetic patients with noncancerous cachexia and hypertrophic obesity. AT in GH-deficient adults displayed a substantial reduction of zinc-α2-glycoprotein. GH therapy normalized AT zinc-α2-glycoprotein. Obesity-related relative GH deficit was associated with almost 80% reduction of zinc-α2-glycoprotein mRNA in AT. GH increased zinc-α2-glycoprotein mRNA in both AT of obese men and primary human adipocytes. Interdependence of GH and zinc-α2-glycoprotein in regulating AT morphology and metabolic phenotype was evident from their relationship with adipocyte size and AT-specific and whole-body insulin sensitivity. The results demonstrate that GH is involved in regulation of AT zinc-α2-glycoprotein; however, the molecular mechanism linking GH and zinc-α2-glycoprotein in AT is yet unknown. © 2014 The Obesity Society.

FMRI investigation of cross-modal interactions in beat perception: Audition primes vision, but not vice versa

PubMed Central

Grahn, Jessica A.; Henry, Molly J.; McAuley, J. Devin

2011-01-01

How we measure time and integrate temporal cues from different sensory modalities are fundamental questions in neuroscience. Sensitivity to a “beat” (such as that routinely perceived in music) differs substantially between auditory and visual modalities. Here we examined beat sensitivity in each modality, and examined cross-modal influences, using functional magnetic resonance imaging (fMRI) to characterize brain activity during perception of auditory and visual rhythms. In separate fMRI sessions, participants listened to auditory sequences or watched visual sequences. The order of auditory and visual sequence presentation was counterbalanced so that cross-modal order effects could be investigated. Participants judged whether sequences were speeding up or slowing down, and the pattern of tempo judgments was used to derive a measure of sensitivity to an implied beat. As expected, participants were less sensitive to an implied beat in visual sequences than in auditory sequences. However, visual sequences produced a stronger sense of beat when preceded by auditory sequences with identical temporal structure. Moreover, increases in brain activity were observed in the bilateral putamen for visual sequences preceded by auditory sequences when compared to visual sequences without prior auditory exposure. No such order-dependent differences (behavioral or neural) were found for the auditory sequences. The results provide further evidence for the role of the basal ganglia in internal generation of the beat and suggest that an internal auditory rhythm representation may be activated during visual rhythm perception. PMID:20858544

Comparison of two stand-alone CADe systems at multiple operating points

NASA Astrophysics Data System (ADS)

Sahiner, Berkman; Chen, Weijie; Pezeshk, Aria; Petrick, Nicholas

2015-03-01

Computer-aided detection (CADe) systems are typically designed to work at a given operating point: The device displays a mark if and only if the level of suspiciousness of a region of interest is above a fixed threshold. To compare the standalone performances of two systems, one approach is to select the parameters of the systems to yield a target false-positive rate that defines the operating point, and to compare the sensitivities at that operating point. Increasingly, CADe developers offer multiple operating points, which necessitates the comparison of two CADe systems involving multiple comparisons. To control the Type I error, multiple-comparison correction is needed for keeping the family-wise error rate (FWER) less than a given alpha-level. The sensitivities of a single modality at different operating points are correlated. In addition, the sensitivities of the two modalities at the same or different operating points are also likely to be correlated. It has been shown in the literature that when test statistics are correlated, well-known methods for controlling the FWER are conservative. In this study, we compared the FWER and power of three methods, namely the Bonferroni, step-up, and adjusted step-up methods in comparing the sensitivities of two CADe systems at multiple operating points, where the adjusted step-up method uses the estimated correlations. Our results indicate that the adjusted step-up method has a substantial advantage over other the two methods both in terms of the FWER and power.

Highly sensitive and quantitative evaluation of the EGFR T790M mutation by nanofluidic digital PCR

PubMed Central

Iwama, Eiji; Takayama, Koichi; Harada, Taishi; Okamoto, Isamu; Ookubo, Fumihiko; Kishimoto, Junji; Baba, Eishi; Oda, Yoshinao; Nakanishi, Yoichi

2015-01-01

The mutation of T790M in EGFR is a major mechanism of resistance to treatment with EGFR-TKIs. Only qualitative detection (presence or absence) of T790M has been described to date, however. Digital PCR (dPCR) analysis has recently been applied to the quantitative detection of target molecules in cancer with high sensitivity. In the present study, 25 tumor samples (13 obtained before and 12 after EGFR-TKI treatment) from 18 NSCLC patients with activating EGFR mutations were evaluated for T790M with dPCR. The ratio of the number of T790M alleles to that of activating mutation alleles (T/A) was determined. dPCR detected T790M in all 25 samples. Although T790M was present in all pre-TKI samples from 13 patients, 10 of these patients had a low T/A ratio and manifested substantial tumor shrinkage during treatment with EGFR-TKIs. In six of seven patients for whom both pre- and post-TKI samples were available, the T/A ratio increased markedly during EGFR-TKI treatment. Highly sensitive dPCR thus detected T790M in all NSCLC patients harboring activating EGFR mutations whether or not they had received EGFR-TKI treatment. Not only highly sensitive but also quantitative detection of T790M is important for evaluation of the contribution of T790M to EGFR-TKI resistance. PMID:26015401

Profiling secondary metabolites of needles of ozone-fumigated white pine (Pinus strobus) clones by thermally assisted hydrolysis/methylation GC/MS.

PubMed

Shadkami, F; Helleur, R J; Cox, R M

2007-07-01

Plant secondary metabolites have an important role in defense responses against herbivores and pathogens, and as a chemical barrier to elevated levels of harmful air pollutants. This study involves the rapid chemical profiling of phenolic and diterpene resin acids in needles of two (ozone-tolerant and ozone-sensitive) white pine (Pinus strobus) clones, fumigated with different ozone levels (control, and daily events peaking at 80 and 200 ppb) for 40 days. The phenolic and resin acids were measured using thermally assisted hydrolysis and methylation (THM) gas chromatography/mass spectrometry. Short-term fumigation affected the levels of two phenolic acids, i.e., 3-hydroxybenzoic and 3,4-dihydroxybenzoic acids, in that both showed a substantial decrease in concentration with increased ozone dose. The decrease in concentration of these THM products may be caused by inhibition of the plant's shikimate biochemical pathway caused by ozone exposure. The combined occurrence of these two ozone-sensitive indicators has a role in biomonitoring of ozone levels and its impact on forest productivity. In addition, chromatographic profile differences in the major diterpene resin acid components were observed between ozone-tolerant and ozone-sensitive clones. The resin acids anticopalic, 3-oxoanticopalic, 3beta-hydroxyanticopalic, and 3,4-cycloanticopalic acids were present in the ozone-sensitive pine; however, only anticopalic acid was present in the ozone-tolerant clone. This phenotypic variation in resin acid composition may be useful in distinguishing populations that are differentially adapted to air pollutants.

The New "Obstetrical Dilemma": Stunting, Obesity and the Risk of Obstructed Labour.

PubMed

Wells, Jonathan C K

2017-04-01

The "obstetrical dilemma" refers to the tight fit between maternal pelvic dimensions and neonatal size at delivery. Most interest traditionally focused on its generic significance for humans, for example our neonatal altriciality and our complex and lengthy birth process. Across contemporary populations, however, the obstetrical dilemma manifests substantial variability, illustrated by differences in the incidence of cephalo-pelvic disproportion, obstructed labour and cesarean section. Beyond accounting for 12% of maternal mortality worldwide, obstructed labour also imposes a huge burden of maternal morbidity, in particular through debilitating birth injuries. This article explores how the double burden of malnutrition and the global obesity epidemic may be reshaping the obstetrical dilemma. First, short maternal stature increases the risk of obstructed labour, while early age at marriage also risks pregnancy before pelvic growth is completed. Second, maternal obesity increases the risk of macrosomic offspring. In some populations, short maternal stature may also promote the risk of gestational diabetes, another risk factor for macrosomic offspring. These nutritional influences are furthermore sensitive to social values relating to issues such as maternal and child nutrition, gender inequality and age at marriage. Secular trends in maternal obesity are substantially greater than those in adult stature, especially in low- and middle-income countries. The association between the dual burden of malnutrition and the obstetrical dilemma is therefore expected to increase, because the obesity epidemic is emerging faster than stunting is being resolved. However, we currently lack objective population-specific data on the association between maternal obesity and birth injuries. Anat Rec, 300:716-731, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

A Simplified Apparatus for Ebullioscopic Measurements of Air/Moisture Sensitive Compounds.

ERIC Educational Resources Information Center

Bulkin, Bernard J.; Tergis, Paul

1979-01-01

An ebullioscopic apparatus is described in which only the difference between the boiling point of the solution and that of the pure solvent is measured. This substantially reduces the cost of the apparatus and simplifies the operation, while maintaining precision. (BB)

Sensitivity of climate mitigation strategies to natural disturbances

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le Page, Yannick LB; Hurtt, George; Thomson, Allison M.

2013-02-19

The present and future concentration of atmospheric carbon dioxide depends on both anthropogenic and natural sources and sinks of carbon. Most proposed climate mitigation strategies rely on a progressive transition to carbon12 efficient technologies to reduce industrial emissions, substantially supported by policies to maintain or enhance the terrestrial carbon stock in forests and other ecosystems. This strategy may be challenged if terrestrial sequestration capacity is affected by future climate feedbacks, but how and to what extent is little understood. Here, we show that climate mitigation strategies are highly sensitive to future natural disturbance rates (e.g. fires, hurricanes, droughts), because ofmore » potential effect of disturbances on the terrestrial carbon balance. Generally, altered disturbance rates affect the pace of societal and technological transitions required to achieve the mitigation target, with substantial consequences on the energy sector and on the global economy. Understanding the future dynamics and consequences of natural disturbances on terrestrial carbon balance is thus essential for developing robust climate mitigation strategies and policies« less

CMB internal delensing with general optimal estimator for higher-order correlations

DOE PAGES

Namikawa, Toshiya

2017-05-24

We present here a new method for delensing B modes of the cosmic microwave background (CMB) using a lensing potential reconstructed from the same realization of the CMB polarization (CMB internal delensing). The B -mode delensing is required to improve sensitivity to primary B modes generated by, e.g., the inflationary gravitational waves, axionlike particles, modified gravity, primordial magnetic fields, and topological defects such as cosmic strings. However, the CMB internal delensing suffers from substantial biases due to correlations between observed CMB maps to be delensed and that used for reconstructing a lensing potential. Since the bias depends on realizations, wemore » construct a realization-dependent (RD) estimator for correcting these biases by deriving a general optimal estimator for higher-order correlations. The RD method is less sensitive to simulation uncertainties. Compared to the previous ℓ -splitting method, we find that the RD method corrects the biases without substantial degradation of the delensing efficiency.« less

Variation in learning curves and competence for ERCP among advanced endoscopy trainees by using cumulative sum analysis.

PubMed

Wani, Sachin; Hall, Matthew; Wang, Andrew Y; DiMaio, Christopher J; Muthusamy, V Raman; Keswani, Rajesh N; Brauer, Brian C; Easler, Jeffrey J; Yen, Roy D; El Hajj, Ihab; Fukami, Norio; Ghassemi, Kourosh F; Gonzalez, Susana; Hosford, Lindsay; Hollander, Thomas G; Wilson, Robert; Kushnir, Vladimir M; Ahmad, Jawad; Murad, Faris; Prabhu, Anoop; Watson, Rabindra R; Strand, Daniel S; Amateau, Stuart K; Attwell, Augustin; Shah, Raj J; Early, Dayna; Edmundowicz, Steven A; Mullady, Daniel

2016-04-01

There are limited data on learning curves and competence in ERCP. By using a standardized data collection tool, we aimed to prospectively define learning curves and measure competence among advanced endoscopy trainees (AETs) by using cumulative sum (CUSUM) analysis. AETs were evaluated by attending endoscopists starting with the 26th hands-on ERCP examination and then every ERCP examination during the 12-month training period. A standardized ERCP competency assessment tool (using a 4-point scoring system) was used to grade the examination. CUSUM analysis was applied to produce learning curves for individual technical and cognitive components of ERCP performance (success defined as a score of 1, acceptable and unacceptable failures [p1] of 10% and 20%, respectively). Sensitivity analyses varying p1 and by using a less-stringent definition of success were performed. Five AETs were included with a total of 1049 graded ERCPs (mean ± SD, 209.8 ± 91.6/AET). The majority of cases were performed for a biliary indication (80%). The overall and native papilla allowed cannulation times were 3.1 ± 3.6 and 5.7 ± 4, respectively. Overall learning curves demonstrated substantial variability for individual technical and cognitive endpoints. Although nearly all AETs achieved competence in overall cannulation, none achieved competence for cannulation in cases with a native papilla. Sensitivity analyses increased the proportion of AETs who achieved competence. This study demonstrates that there is substantial variability in ERCP learning curves among AETs. A specific case volume does not ensure competence, especially for native papilla cannulation. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Normal Development and Measurements of the Occipital Condyle-C1 Interval in Children and Young Adults.

PubMed

Smith, P; Linscott, L L; Vadivelu, S; Zhang, B; Leach, J L

2016-05-01

Widening of the occipital condyle-C1 interval is the most specific and sensitive means of detecting atlanto-occipital dislocation. Recent studies attempting to define normal measurements of the condyle-C1 interval in children have varied substantially. This study was performed to test the null hypothesis that condyle-C1 interval morphology and joint measurements do not change as a function of age. Imaging review of subjects undergoing CT of the upper cervical spine for reasons unrelated to trauma or developmental abnormality was performed. Four equidistant measurements were obtained for each bilateral condyle-C1 interval on sagittal and coronal images. The cohort was divided into 7 age groups to calculate the mean, SD, and 95% CIs for the average condyle-C1 interval in both planes. The prevalence of a medial occipital condyle notch was calculated. Two hundred forty-eight joints were measured in 124 subjects with an age range of 2 days to 22 years. The condyle-C1 interval varies substantially by age. Average coronal measurements are larger and more variable than sagittal measurements. The medial occipital condyle notch is most prevalent from 1 to 12 years and is uncommon in older adolescents and young adults. The condyle-C1 interval increases during the first several years of life, is largest in the 2- to 4-year age range, and then decreases through late childhood and adolescence. A single threshold value to detect atlanto-occipital dissociation may not be sensitive and specific for all age groups. Application of this normative data to documented cases of atlanto-occipital injury is needed to determine clinical utility. © 2016 by American Journal of Neuroradiology.

Mechanisms of Firing Patterns in Fast-Spiking Cortical Interneurons

PubMed Central

Golomb, David; Donner, Karnit; Shacham, Liron; Shlosberg, Dan; Amitai, Yael; Hansel, David

2007-01-01

Cortical fast-spiking (FS) interneurons display highly variable electrophysiological properties. Their spike responses to step currents occur almost immediately following the step onset or after a substantial delay, during which subthreshold oscillations are frequently observed. Their firing patterns include high-frequency tonic firing and rhythmic or irregular bursting (stuttering). What is the origin of this variability? In the present paper, we hypothesize that it emerges naturally if one assumes a continuous distribution of properties in a small set of active channels. To test this hypothesis, we construct a minimal, single-compartment conductance-based model of FS cells that includes transient Na+, delayed-rectifier K+, and slowly inactivating d-type K+ conductances. The model is analyzed using nonlinear dynamical system theory. For small Na+ window current, the neuron exhibits high-frequency tonic firing. At current threshold, the spike response is almost instantaneous for small d-current conductance, g d, and it is delayed for larger g d. As g d further increases, the neuron stutters. Noise substantially reduces the delay duration and induces subthreshold oscillations. In contrast, when the Na+ window current is large, the neuron always fires tonically. Near threshold, the firing rates are low, and the delay to firing is only weakly sensitive to noise; subthreshold oscillations are not observed. We propose that the variability in the response of cortical FS neurons is a consequence of heterogeneities in their g d and in the strength of their Na+ window current. We predict the existence of two types of firing patterns in FS neurons, differing in the sensitivity of the delay duration to noise, in the minimal firing rate of the tonic discharge, and in the existence of subthreshold oscillations. We report experimental results from intracellular recordings supporting this prediction. PMID:17696606

Mechanisms of firing patterns in fast-spiking cortical interneurons.

PubMed

Golomb, David; Donner, Karnit; Shacham, Liron; Shlosberg, Dan; Amitai, Yael; Hansel, David

2007-08-01

Cortical fast-spiking (FS) interneurons display highly variable electrophysiological properties. Their spike responses to step currents occur almost immediately following the step onset or after a substantial delay, during which subthreshold oscillations are frequently observed. Their firing patterns include high-frequency tonic firing and rhythmic or irregular bursting (stuttering). What is the origin of this variability? In the present paper, we hypothesize that it emerges naturally if one assumes a continuous distribution of properties in a small set of active channels. To test this hypothesis, we construct a minimal, single-compartment conductance-based model of FS cells that includes transient Na(+), delayed-rectifier K(+), and slowly inactivating d-type K(+) conductances. The model is analyzed using nonlinear dynamical system theory. For small Na(+) window current, the neuron exhibits high-frequency tonic firing. At current threshold, the spike response is almost instantaneous for small d-current conductance, gd, and it is delayed for larger gd. As gd further increases, the neuron stutters. Noise substantially reduces the delay duration and induces subthreshold oscillations. In contrast, when the Na(+) window current is large, the neuron always fires tonically. Near threshold, the firing rates are low, and the delay to firing is only weakly sensitive to noise; subthreshold oscillations are not observed. We propose that the variability in the response of cortical FS neurons is a consequence of heterogeneities in their gd and in the strength of their Na(+) window current. We predict the existence of two types of firing patterns in FS neurons, differing in the sensitivity of the delay duration to noise, in the minimal firing rate of the tonic discharge, and in the existence of subthreshold oscillations. We report experimental results from intracellular recordings supporting this prediction.

Seasonality of global and Arctic black carbon processes in the Arctic Monitoring and Assessment Programme models: Global and Arctic Black Carbon Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahmood, Rashed; von Salzen, Knut; Flanner, Mark

2016-06-22

This study quantifies black carbon (BC) processes in three global climate models and one chemistry transport model, with focus on the seasonality of BC transport, emissions, wet and dry deposition in the Arctic. In the models, transport of BC to the Arctic from lower latitudes is the major BC source for this region while Arctic emissions are very small. All models simulated a similar annual cycle of BC transport from lower latitudes to the Arctic, with maximum transport occurring in July. Substantial differences were found in simulated BC burdens and vertical distributions, with CanAM (NorESM) producing the strongest (weakest) seasonalmore » cycle. CanAM also has the shortest annual mean residence time for BC in the Arctic followed by SMHI-MATCH, CESM and NorESM. The relative contribution of wet and dry deposition rates in removing BC varies seasonally and is one of the major factors causing seasonal variations in BC burdens in the Arctic. Overall, considerable differences in wet deposition efficiencies in the models exist and are a leading cause of differences in simulated BC burdens. Results from model sensitivity experiments indicate that scavenging of BC in convective clouds acts to substantially increase the overall efficiency of BC wet deposition in the Arctic, which leads to low BC burdens and a more pronounced seasonal cycle compared to simulations without convective BC scavenging. In contrast, the simulated seasonality of BC concentrations in the upper troposphere is only weakly influenced by wet deposition in stratiform (layer) clouds whereas lower tropospheric concentrations are highly sensitive.« less

The sensitivity of past and near-future lunar radio experiments to ultra-high-energy cosmic rays and neutrinos

NASA Astrophysics Data System (ADS)

Bray, J. D.

2016-04-01

Various experiments have been conducted to search for the radio emission from ultra-high-energy (UHE) particles interacting in the lunar regolith. Although they have not yielded any detections, they have been successful in establishing upper limits on the flux of these particles. I present a review of these experiments in which I re-evaluate their sensitivity to radio pulses, accounting for effects which were neglected in the original reports, and compare them with prospective near-future experiments. In several cases, I find that past experiments were substantially less sensitive than previously believed. I apply existing analytic models to determine the resulting limits on the fluxes of UHE neutrinos and cosmic rays (CRs). In the latter case, I amend the model to accurately reflect the fraction of the primary particle energy which manifests in the resulting particle cascade, resulting in a substantial improvement in the estimated sensitivity to CRs. Although these models are in need of further refinement, in particular to incorporate the effects of small-scale lunar surface roughness, their application here indicates that a proposed experiment with the LOFAR telescope would test predictions of the neutrino flux from exotic-physics models, and an experiment with a phased-array feed on a large single-dish telescope such as the Parkes radio telescope would allow the first detection of CRs with this technique, with an expected rate of one detection per 140 h.

Assessment of boreal forest historical C dynamics in the Yukon River Basin: relative roles of warming and fire regime change.

PubMed

Yuan, F M; Yi, S H; McGuire, A D; Johnson, K D; Liang, J; Harden, J W; Kasischke, E S; Kurz, W A

2012-12-01

Carbon (C) dynamics of boreal forest ecosystems have substantial implications for efforts to mitigate the rise of atmospheric CO2 and may be substantially influenced by warming and changing wildfire regimes. In this study we applied a large-scale ecosystem model that included dynamics of organic soil horizons and soil organic matter characteristics of multiple pools to assess forest C stock changes of the Yukon River Basin (YRB) in Alaska, USA, and Canada from 1960 through 2006, a period characterized by substantial climate warming and increases in wildfire. The model was calibrated for major forests with data from long-term research sites and evaluated using a forest inventory database. The regional assessment indicates that forest vegetation C storage increased by 46 Tg C, but that total soil C storage did not change appreciably during this period. However, further analysis suggests that C has been continuously lost from the mineral soil horizon since warming began in the 1970s, but has increased in the amorphous organic soil horizon. Based on a factorial experiment, soil C stocks would have increased by 158 Tg C if the YRB had not undergone warming and changes in fire regime. The analysis also identified that warming and changes in fire regime were approximately equivalent in their effects on soil C storage, and interactions between these two suggests that the loss of organic horizon thickness associated with increases in wildfire made deeper soil C stocks more vulnerable to loss via decomposition. Subbasin analyses indicate that C stock changes were primarily sensitive to the fraction of burned forest area within each subbasin and that boreal forest ecosystems in the YRB are currently transitioning from being sinks to sources at -0.7% annual area burned. We conclude that it is important for international mitigation efforts focused on controlling atmospheric CO2 to consider how climate warming and changes in fire regime may concurrently affect the CO2 sink strength of boreal forests. It is also important for large-scale biogeochemical and earth system models to include organic soil dynamics in applications to assess regional C dynamics of boreal forests responding to warming and changes in fire regime.

Assessment of boreal forest historical C dynamics in Yukon River Basin: relative roles of warming and fire regime change

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Fengming; Yi, Shuhua; McGuire, A. David

2012-01-01

Carbon (C) dynamics of boreal forest ecosystems have substantial implications for efforts to mitigate the rise of atmospheric CO2 and may be substantially influenced by warming and changing wildfire regimes. In this study we applied a large-scale ecosystem model that included dynamics of organic soil horizons and soil organic matter characteristics of multiple pools to assess forest C stock changes of the Yukon River Basin (YRB) in Alaska, USA, and Canada from 1960 through 2006, a period characterized by substantial climate warming and increases in wildfire. The model was calibrated for major forests with data from long-term research sites andmore » evaluated using a forest inventory database. The regional assessment indicates that forest vegetation C storage increased by 46 Tg C, but that total soil C storage did not change appreciably during this period. However, further analysis suggests that C has been continuously lost from the mineral soil horizon since warming began in the 1970s, but has increased in the amorphous organic soil horizon. Based on a factorial experiment, soil C stocks would have increased by 158 Tg C if the YRB had not undergone warming and changes in fire regime. The analysis also identified that warming and changes in fire regime were approximately equivalent in their effects on soil C storage, and interactions between these two suggests that the loss of organic horizon thickness associated with increases in wildfire made deeper soil C stocks more vulnerable to loss via decomposition. Subbasin analyses indicate that C stock changes were primarily sensitive to the fraction of burned forest area within each subbasin and that boreal forest ecosystems in the YRB are currently transitioning from being sinks to sources at ;0.7% annual area burned. We conclude that it is important for international mitigation efforts focused on controlling atmospheric CO2 to consider how climate warming and changes in fire regime may concurrently affect the CO2 sink strength of boreal forests. It is also important for large-scale biogeochemical and earth system models to include organic soil dynamics in applications to assess regional C dynamics of boreal forests responding to warming and changes in fire regime.« less

Assessment of boreal forest historical C dynamics in the Yukon River Basin: relative roles of warming and fire regime change

USGS Publications Warehouse

Yuan, F.M.; Yi, S.H.; McGuire, A.D.; Johnson, K.D.; Liang, J.; Harden, J.W.; Kasischke, E.S.; Kurz, W.A.

2012-01-01

Carbon (C) dynamics of boreal forest ecosystems have substantial implications for efforts to mitigate the rise of atmospheric CO2 and may be substantially influenced by warming and changing wildfire regimes. In this study we applied a large-scale ecosystem model that included dynamics of organic soil horizons and soil organic matter characteristics of multiple pools to assess forest C stock changes of the Yukon River Basin (YRB) in Alaska, USA, and Canada from 1960 through 2006, a period characterized by substantial climate warming and increases in wildfire. The model was calibrated for major forests with data from long-term research sites and evaluated using a forest inventory database. The regional assessment indicates that forest vegetation C storage increased by 46 Tg C, but that total soil C storage did not change appreciably during this period. However, further analysis suggests that C has been continuously lost from the mineral soil horizon since warming began in the 1970s, but has increased in the amorphous organic soil horizon. Based on a factorial experiment, soil C stocks would have increased by 158 Tg C if the YRB had not undergone warming and changes in fire regime. The analysis also identified that warming and changes in fire regime were approximately equivalent in their effects on soil C storage, and interactions between these two suggests that the loss of organic horizon thickness associated with increases in wildfire made deeper soil C stocks more vulnerable to loss via decomposition. Subbasin analyses indicate that C stock changes were primarily sensitive to the fraction of burned forest area within each subbasin and that boreal forest ecosystems in the YRB are currently transitioning from being sinks to sources at ∼0.7% annual area burned. We conclude that it is important for international mitigation efforts focused on controlling atmospheric CO2 to consider how climate warming and changes in fire regime may concurrently affect the CO2 sink strength of boreal forests. It is also important for large-scale biogeochemical and earth system models to include organic soil dynamics in applications to assess regional C dynamics of boreal forests responding to warming and changes in fire regime.

When will we be committed to crossing 1.5 and 2 °C temperature thresholds?

NASA Astrophysics Data System (ADS)

Armour, K.; Proistosescu, C.; Roe, G.; Huybers, P. J.

2017-12-01

The zero-emissions climate commitment is a key metric for science and policy. It is the future warming we face given only to-date emissions, independent of future human influence on climate. Following a cessation of emissions, future global temperature change depends on (i) the atmospheric lifetimes of aerosols and greenhouse gases (GHGs), and (ii) the physical climate response to radiative forcing (Armour and Roe 2011). The cooling effect of aerosols diminishes within weeks; GHG concentrations get drawn down on timescales ranging from months to millennia; and ocean heat uptake diminishes as climate equilibrates with the residual CO2 forcing. Whether global temperature increases, stays stable, or declines following emission cessation depends on these competing factors. There is substantial uncertainty in the zero-emissions commitment due to a combination of (i) correlated uncertainties in aerosol radiative forcing and climate sensitivity, (ii) uncertainty in the atmospheric lifetime of CO2, and (iii) uncertainty in how climate sensitivity will evolve in the future. Here we quantify climate commitment in a Bayesian framework of an idealized model constrained by observations of global warming and energy imbalance, combined with estimates of global radiative forcing. At present, our committed warming is 1.2°C (median), with a 25% chance that it already exceeds 1.5°C and a 5% chance that it exceeds 2°C; the range comes primarily from uncertainty in the degree to which aerosols currently mask GHG forcing. We further quantify how climate commitment, and its uncertainty, changes with emissions scenario and over time. Under high emissions (RCP8.5), we will reach a >50% risk of a 2°C zero-emission climate commitment by the year 2035, about two decades before that temperature would be reached if emissions continued unabated. Committed warming is substantially reduced for lower-emissions scenarios, depending on the mix of aerosol and GHG mitigation. For the next few decades the primary uncertainty in climate commitment comes from correlated uncertainties in aerosol forcing and climate sensitivity; later in the century it comes from uncertainties in the carbon cycle (setting the lifetime and residual concentration of CO2) and in how climate sensitivity changes over time.

Scanning Laser Ophthalmoscope Measurement of Local Fundus Reflectance and Autofluorescence Changes Arising from Rhodopsin Bleaching and Regeneration

PubMed Central

Morgan, Jessica I. W.; Pugh, Edward N.

2013-01-01

Purpose. We measured the bleaching and regeneration kinetics of rhodopsin in the living human eye with two-wavelength, wide-field scanning laser ophthalmoscopy (SLO), and investigated the effect of rhodopsin bleaching on autofluorescence intensity. Methods. The retina was imaged with an Optos P200C SLO by its reflectance of 532 and 633 nm light, and its autofluorescence excited by 532 nm light, before and after exposure to lights calibrated to bleach rhodopsin substantially. Bleaching was confined to circular retinal regions of 4.8° visual angle located approximately 16° superotemporal and superonasal to fixation. Images were captured as 12-bit tiff files and postprocessed to extract changes in reflectance and autofluorescence. Results. At the locus of bleaching transient increases in reflectance of the 532 nm, but not the 633 nm beam were observed readily and quantified. A transient increase in autofluorescence also occurred. The action spectrum, absolute sensitivity, and recovery of the 532 nm reflectance increase were consistent with previous measurements of human rhodopsin's spectral sensitivity, photosensitivity, and regeneration kinetics. The autofluorescence changes closely tracked the changes in rhodopsin density. Conclusions. The bleaching and regeneration kinetics of rhodopsin can be measured locally in the human retina with a widely available SLO. The increased autofluorescence excited by 532 nm light upon bleaching appears primarily due to transient elimination of rhodopsin's screening of autofluorescent fluorochromes in the RPE. The spatially localized measurement with a widely available SLO of rhodopsin, the most abundant protein in the retina, could be a valuable adjunct to retinal health assessment. PMID:23412087

Scanning laser ophthalmoscope measurement of local fundus reflectance and autofluorescence changes arising from rhodopsin bleaching and regeneration.

PubMed

Morgan, Jessica I W; Pugh, Edward N

2013-03-01

We measured the bleaching and regeneration kinetics of rhodopsin in the living human eye with two-wavelength, wide-field scanning laser ophthalmoscopy (SLO), and investigated the effect of rhodopsin bleaching on autofluorescence intensity. The retina was imaged with an Optos P200C SLO by its reflectance of 532 and 633 nm light, and its autofluorescence excited by 532 nm light, before and after exposure to lights calibrated to bleach rhodopsin substantially. Bleaching was confined to circular retinal regions of 4.8° visual angle located approximately 16° superotemporal and superonasal to fixation. Images were captured as 12-bit tiff files and postprocessed to extract changes in reflectance and autofluorescence. At the locus of bleaching transient increases in reflectance of the 532 nm, but not the 633 nm beam were observed readily and quantified. A transient increase in autofluorescence also occurred. The action spectrum, absolute sensitivity, and recovery of the 532 nm reflectance increase were consistent with previous measurements of human rhodopsin's spectral sensitivity, photosensitivity, and regeneration kinetics. The autofluorescence changes closely tracked the changes in rhodopsin density. The bleaching and regeneration kinetics of rhodopsin can be measured locally in the human retina with a widely available SLO. The increased autofluorescence excited by 532 nm light upon bleaching appears primarily due to transient elimination of rhodopsin's screening of autofluorescent fluorochromes in the RPE. The spatially localized measurement with a widely available SLO of rhodopsin, the most abundant protein in the retina, could be a valuable adjunct to retinal health assessment.

Conifer expansion reduces the competitive ability and herbivore defense of aspen by modifying light environment and soil chemistry.

PubMed

Calder, W John; Horn, Kevin J; St Clair, Samuel B

2011-06-01

Disturbance patterns strongly influence plant community structure. What remains less clear, particularly at a mechanistic level, is how changes in disturbance cycles alter successional outcomes in plant communities. There is evidence that fire suppression is resulting in longer fire return intervals in subalpine forests and that these lengthened intervals increase competitive interactions between aspen and conifer species. We conducted a field and greenhouse study to compare photosynthesis, growth and defense responses of quaking aspen and subalpine fir regeneration under light reductions and shifts in soil chemistry that occur as conifers increase in dominance. The studies demonstrated that aspen regeneration was substantially more sensitive to light and soil resource limitations than that of subalpine fir. For aspen, light reductions and/or shifts in soil chemistry limited height growth, biomass gain, photosynthesis and the production of defense compounds (phenolic glycosides and condensed tannins). Biomass gain and phenolic glycoside concentrations were co-limited by light reduction and changes in soil chemistry. In contrast, subalpine fir seedlings tended to be more tolerant of low light conditions and showed no sensitivity to changes in soil chemistry. Unlike aspen, subalpine fir increased its root to shoot ratio on conifer soils, which may partially explain its maintenance of growth and defense. The results suggest that increasing dominance of conifers in subalpine forests alters light conditions and soil chemistry in a way that places greater physiological and growth constraints on aspen than subalpine fir, with a likely outcome being more successful recruitment of conifers and losses in aspen cover.

Flying high: a theoretical analysis of the factors limiting exercise performance in birds at altitude.

PubMed

Scott, Graham R; Milsom, William K

2006-11-01

The ability of some bird species to fly at extreme altitude has fascinated comparative respiratory physiologists for decades, yet there is still no consensus about what adaptations enable high altitude flight. Using a theoretical model of O(2) transport, we performed a sensitivity analysis of the factors that might limit exercise performance in birds. We found that the influence of individual physiological traits on oxygen consumption (Vo2) during exercise differed between sea level, moderate altitude, and extreme altitude. At extreme altitude, haemoglobin (Hb) O(2) affinity, total ventilation, and tissue diffusion capacity for O(2) (D(To2)) had the greatest influences on Vo2; increasing these variables should therefore have the greatest adaptive benefit for high altitude flight. There was a beneficial interaction between D(To2) and the P(50) of Hb, such that increasing D(To2) had a greater influence on Vo2 when P(50) was low. Increases in the temperature effect on P(50) could also be beneficial for high flying birds, provided that cold inspired air at extreme altitude causes a substantial difference in temperature between blood in the lungs and in the tissues. Changes in lung diffusion capacity for O(2), cardiac output, blood Hb concentration, the Bohr coefficient, or the Hill coefficient likely have less adaptive significance at high altitude. Our sensitivity analysis provides theoretical suggestions of the adaptations most likely to promote high altitude flight in birds and provides direction for future in vivo studies.

Enhancement in the sensitivity of microfluidic enzyme-linked immunosorbent assays through analyte preconcentration.

PubMed

Yanagisawa, Naoki; Dutta, Debashis

2012-08-21

In this Article, we describe a microfluidic enzyme-linked immunosorbent assay (ELISA) method whose sensitivity can be substantially enhanced through preconcentration of the target analyte around a semipermeable membrane. The reported preconcentration has been accomplished in our current work via electrokinetic means allowing a significant increase in the amount of captured analyte relative to nonspecific binding in the trapping/detection zone. Upon introduction of an enzyme substrate into this region, the rate of generation of the ELISA reaction product (resorufin) was observed to increase by over a factor of 200 for the sample and 2 for the corresponding blank compared to similar assays without analyte trapping. Interestingly, in spite of nonuniformities in the amount of captured analyte along the surface of our analysis channel, the measured fluorescence signal in the preconcentration zone increased linearly with time over an enzyme reaction period of 30 min and at a rate that was proportional to the analyte concentration in the bulk sample. In our current study, the reported technique has been shown to reduce the smallest detectable concentration of the tumor marker CA 19-9 and Blue Tongue Viral antibody by over 2 orders of magnitude compared to immunoassays without analyte preconcentration. When compared to microwell based ELISAs, the reported microfluidic approach not only yielded a similar improvement in the smallest detectable analyte concentration but also reduced the sample consumption in the assay by a factor of 20 (5 μL versus 100 μL).

Adrenaline and triiodothyronine modify the iron handling in the freshwater air-breathing fish Anabas testudineus Bloch: role of ferric reductase in iron acquisition.

PubMed

Rejitha, V; Peter, M C Subhash

2013-01-15

The effects of in vivo adrenaline and triiodothyronine (T(3)) on ferric reductase (FR) activity, a membrane-bound enzyme that reduces Fe(III) to Fe(II) iron, were studied in the organs of climbing perch (Anabas testudineus Bloch). Adrenaline injection (10 ng g(-1)) for 30 min produced significant inhibition of FR activity in the liver and kidney and that suggests a role for this stress hormone in iron acquisition in this fish. Short-term T(3) injection (40 ng g(-1)) reduced FR activity in the gills of fed fish but not in the unfed fish. Similar reduction of FR activity was also obtained in the intestine and kidney of fed fish after T(3) injection. Feeding produced pronounced decline in FR activity in the spleen but T(3) challenge in fed and unfed fish increased its activity in this iron storing organ and that point to the sensitivity of FR system to feeding activity. The in vitro effects of Fe on FR activity in the gill explants of freshwater fish showed correlations of FR with Na(+), K(+)-ATPase and H(+)-ATPase activities. Substantial increase in the FR activity was found in the gill explants incubated with all the tested doses of Fe(II) iron (1.80, 3.59 and 7.18 μM) and Fe(III) iron (1.25, 2.51 and 5.02 μM) and this indicate that FR and Na pump activity are positively correlated. On the contrary, substantial reduction of gill H(+)-ATPase activity was found in the gill explants incubated with Fe(II) iron and Fe(III) iron indicating that perch gills may not require a high acidic microenvironment for the reduction of Fe(III) iron. Accumulation of iron in the gill explants after Fe(III) iron incubation implies a direct relationship between Fe acquisition and FR activity in this tissue. The inverse correlation between FR activity and H(+)-ATPase activity in Fe(II) or Fe(III) loaded gills and the significant positive correlations of FR activity with total [Fe] content in the Fe(III) loaded gills substantiate that FR which shows sensitivity to sodium and proton pumps, has a vital role in Fe(II) and Fe(III) iron handling in this fish. Our data also provide evidence that adrenaline, T(3) and the feeding status are the vital factors that can regulate the storage and handling of iron in fish. Copyright © 2012 Elsevier Inc. All rights reserved.

The significance of discharge in the replenishment of sand bar deposits along the Colorado River through the Grand Canyon

NASA Astrophysics Data System (ADS)

Wiele, S.; Hazel, J.; Schmidt, J. C.; Melis, T.

2002-12-01

Topographic sandbar surveys, recovered scour chains, analysis of aerial photos, and modeling of sand deposition demonstrate that releases from Glen Canyon Dam greater than power-plant capacity (PPC; about 900 cubic meters per second) are significantly more effective than PPC-limited releases at redistributing sand from the channel bed to higher elevations along the channel margin. A release of 1,270 m3/s (1.4 times the PPC) for 7 days in 1996 tested the effectiveness with which sandbars could be restored by the manipulation of dam releases aimed at redistributing a limited sand supply. This high flow generally resulted in substantial increases in bar size, although some sandbars close to the dam eroded. Since 1996, releases for bar building and habitat maintenance (a 2-day release in 1997 and two 4-day releases in 2000) have been limited to PPC. Field measurements indicate that the 1996 release of 1,270 m3/s significantly increased the area and volume of sand deposits at elevations greater than the stage reached during typical post-dam flows. Minor aggradation occurred during the PPC flows. In 1996, the relative extent of erosion and deposition changed longitudinally downstream as evidenced by the area of substantial deposition exceeding that of erosion at sites further downstream. The number of bars that were substantially reworked, as measured by the number of bars that significantly increased or decreased in area at the elevation range of normal dam operations, was much greater at 1,270 m3/s than at 900 m3/s. Deposition from the 1,270 m3/s release persisted at many sites on a multi-year scale whereas deposition resulting from the PPC flows only lasted a few months. Minor deposition during PPC flows in 1997, however, was greatest in upstream reaches where bar erosion during normal flows had been more extensive. These observations show that deposition is sensitive to flow magnitude and depth of inundation as well as sand supply. Flow, sand transport, and bed evolution were modeled for conditions that occurred during PPC flows and at higher discharges, such as those that occurred in 1996. Modeling results show that discharges greater than PPC form larger, higher-elevation deposits than are possible at discharges less than PPC. A key requirement for substantial deposition of new sand along the sides of this narrow, deeply incised river is the availability of depositional sites. PPC flows fail to increase stage sufficiently to create space to accommodate new deposits. The inefficiency of PPC releases at building substantial sandbars is compounded by the efficiency with which channel-bed sand is exported during PPC flows, as shown by sand-transport data collected from 1997-2000. Results to date indicate that restoration and maintenance of sand bars will likely require releases greater than PPC more frequently and of shorter duration than anticipated in the past.

Respiratory uncoupling by increased H(+) or K(+) flux is beneficial for heart mitochondrial turnover of reactive oxygen species but not for permeability transition.

PubMed

Morota, Saori; Piel, Sarah; Hansson, Magnus J

2013-09-22

Ischemic preconditioning has been proposed to involve changes in mitochondrial H(+) and K(+) fluxes, in particular through activation of uncoupling proteins and ATP-sensitive K(+) channels (MitoKATP). The objectives of the present study were to explore how increased H(+) and K(+) fluxes influence heart mitochondrial physiology with regard to production and scavenging of reactive oxygen species (ROS), volume changes and resistance to calcium-induced mitochondrial permeability transition (mPT). Isolated rat heart mitochondria were exposed to a wide concentration range of the protonophore CCCP or the potassium ionophore valinomycin to induce increased H(+) and K(+) conductance, respectively. Simultaneous monitoring of mitochondrial respiration and calcium retention capacity (CRC) demonstrated that the relative increase in respiration caused by valinomycin or CCCP correlated with a decrease in CRC, and that no level of respiratory uncoupling was associated with enhanced resistance to mPT. Mitochondria suspended in hyperosmolar buffer demonstrated a dose-dependent reduction in CRC with increasing osmolarity. However, mitochondria in hypoosmolar buffer to increase matrix volume did not display increased CRC. ROS generation was reduced by both K(+)- and H(+)-mediated respiratory uncoupling. The ability of heart mitochondria to detoxify H2O2 was substantially greater than the production rate. The H2O2 detoxification was dependent on respiratory substrates and was dramatically decreased following calcium-induced mPT, but was unaffected by uncoupling via increased K(+) and H(+) conductance. It is concluded that respiratory uncoupling is not directly beneficial to rat heart mitochondrial resistance to calcium overload irrespective of whether H(+) or K(+) conductance is increased. The negative effects of respiratory uncoupling thus probably outweigh the reduction in ROS generation and a potential positive effect by increased matrix volume, resulting in a net sensitization of heart mitochondria to mPT activation.

Effects of drill cuttings on larvae of the cold-water coral Lophelia pertusa

NASA Astrophysics Data System (ADS)

Järnegren, Johanna; Brooke, Sandra; Jensen, Henrik

2017-03-01

Fossil fuel consumption is predicted to dominate energy needs until at least 2040. To make up for reduced production from maturing fields, oil and gas exploration activities on the Norwegian continental shelf have greatly increased over the past several years. Strict emission controls have resulted in a substantial reduction in the release of hazardous chemicals. However, because of the increased exploration the discharges of water-based drill cuttings and muds have increased substantially, temporarily increasing water column sediment loads. The stony coral Lophelia pertusa is the most widely distributed and well-studied of the structure forming cold water corals (CWC) and it thrives in Norwegian waters where many reefs are located in the vicinity of oil platforms or exploration areas. This species provides habitat for a diverse and abundant assemblage of invertebrates and fishes, including commercially valuable species. High sediment loads are known to negatively affect adult corals, but impacts on the early life history stages are unknown. We investigated the effects of a range of drill cutting concentrations (0.5-640 ppm) on larvae of L. pertusa at ages five days and 15-20 days. One set of experiments was conducted in static experimental chambers that exposed larvae to decreasing concentrations over time, and the other maintained continuous drill cutting concentrations for the duration of the experiment (24 h). Increased sediment load for a duration of 24 h caused significant larval mortality, but there was an age-dependent difference in sensitivity of larvae. Younger larvae were significantly more susceptible to lower concentrations of drill cuttings than older larvae, while the older larvae were significantly more affected at higher concentrations. Five day old larvae were affected at treatment concentration 40 ppm. The larval cilia became clogged, preventing the larvae from swimming actively and ultimately causing mortality. Larvae of many species use cilia for swimming and feeding, so negative impacts of increased sediment may not be limited to corals.

Measuring Terrestrial Ozone from Historic Astronomical Spectra

ERIC Educational Resources Information Center

Griffin, Elizabeth

2009-01-01

"Ozone" is a sensitive topic that arouses interest everywhere. Its presence in the stratosphere affects us all, and its threatened reduction would have such dire consequences that it energizes international campaigns, influences the thinking of governments, and activates substantial alterations in the accustomed habits of millions throughout the…

Photodamage of the cells in culture sensitized with bilirubin

NASA Astrophysics Data System (ADS)

Kozlenkova, O. A.; Plavskaya, L. G.; Mikulich, A. V.; Leusenko, I. A.; Tretyakova, A. I.; Plavskii, V. Yu

2016-08-01

It has been shown that exposure to radiation of LED sources of light with an emission band maximum at about 465 and 520 nm having substantially identical damaging effects on animal cells in culture, that are in a logarithmic growth phase and preincubated with pigment. Photobiological effect is caused by photodynamic processes involving singlet oxygen generated by triplet excited sensitizer. Mono-exponential type dependence of cell survival on the energy dose indicates that it is bilirubin that acts as a sensitizer but not its photoproducts. The inclusion of bilirubin in the cells, where it is primarily localized in the mitochondria cells, it is accompanied by multiple amplification photochemical stability compared to pigment molecules bound with albumin

First Dark Matter Constraints from SuperCDMS Single-Charge Sensitive Detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agnese, R.; et al.

We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS HVeV, a 0.93 gram CDMS HV device). These electron-recoil limits significantly improve experimental constraints on dark matter particles with masses as low as 1 MeV/more » $$\\mathrm{c^2}$$. We demonstrate a sensitivity to dark photons competitive with other leading approaches but using substantially less exposure (0.49 gram days). These results demonstrate the scientific potential of phonon-mediated semiconductor detectors that are sensitive to single electronic excitations.« less

Effects of mineral dust on global atmospheric nitrate concentrations

NASA Astrophysics Data System (ADS)

Karydis, V. A.; Tsimpidi, A. P.; Pozzer, A.; Astitha, M.; Lelieveld, J.

2016-02-01

This study assesses the chemical composition and global aerosol load of the major inorganic aerosol components, focusing on mineral dust and aerosol nitrate. The mineral dust aerosol components (i.e., Ca2+, Mg2+, K+, Na+) and their emissions are included in the ECHAM5/MESSy Atmospheric Chemistry model (EMAC). Gas/aerosol partitioning is simulated using the ISORROPIA-II thermodynamic equilibrium model that considers K+, Ca2+, Mg2+, NH4+, Na+, SO42-, NO3-, Cl-, and H2O aerosol components. Emissions of mineral dust are calculated online by taking into account the soil particle size distribution and chemical composition of different deserts worldwide. Presence of metallic ions can substantially affect the nitrate partitioning into the aerosol phase due to thermodynamic interactions. The model simulates highest fine aerosol nitrate concentration over urban and industrialized areas (1-3 µg m-3), while coarse aerosol nitrate is highest close to deserts (1-4 µg m-3). The influence of mineral dust on nitrate formation extends across southern Europe, western USA, and northeastern China. The tropospheric burden of aerosol nitrate increases by 44 % when considering interactions of nitrate with mineral dust. The calculated global average nitrate aerosol concentration near the surface increases by 36 %, while the coarse- and fine-mode concentrations of nitrate increase by 53 and 21 %, respectively. Other inorganic aerosol components are affected by reactive dust components as well (e.g., the tropospheric burden of chloride increases by 9 %, ammonium decreases by 41 %, and sulfate increases by 7 %). Sensitivity tests show that nitrate aerosol is most sensitive to the chemical composition of the emitted mineral dust, followed by the soil size distribution of dust particles, the magnitude of the mineral dust emissions, and the aerosol state assumption.

Left-digit price effects on smoking cessation motivation.

PubMed

MacKillop, James; Amlung, Michael T; Blackburn, Ashley; Murphy, James G; Carrigan, Maureen; Carpenter, Matthew J; Chaloupka, Frank

2014-11-01

Cigarette price increases have been associated with increases in smoking cessation, but relatively little is known about this relationship at the level of individual smokers. To address this and to inform tax policy, the goal of this study was to apply a behavioural economic approach to the relationship between the price of cigarettes and the probability of attempting smoking cessation. Adult daily smokers (n=1074; ie, 5+ cigarettes/day; 18+ years old; ≥8th grade education) completed in-person descriptive survey assessments. Assessments included estimated probability of making a smoking cessation attempt across a range of cigarette prices, demographics and nicotine dependence. As price increases, probability of making a smoking cessation attempt exhibited an orderly increase, with the form of the relationship being similar to an inverted demand curve. The largest effect size increases in motivation to make a quit attempt were in the form of 'left-digit effects,' (ie, maximal sensitivity across pack price whole-number changes; eg, US$5.80-6/pack). Significant differences were also observed among the left-digit effects, suggesting the most substantial effects were for price changes that were most market relevant. Severity of nicotine dependence was significantly associated with price sensitivity, but not for all indices. These data reveal the clear and robust relationship between the price of cigarettes and an individual's motivation to attempt smoking cessation. Furthermore, the current study indicates the importance of left-digit price transitions in this relationship, suggesting policymakers should consider relative price positions in the context of tax changes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Phenological sensitivity to climate across taxa and trophic levels.

PubMed

Thackeray, Stephen J; Henrys, Peter A; Hemming, Deborah; Bell, James R; Botham, Marc S; Burthe, Sarah; Helaouet, Pierre; Johns, David G; Jones, Ian D; Leech, David I; Mackay, Eleanor B; Massimino, Dario; Atkinson, Sian; Bacon, Philip J; Brereton, Tom M; Carvalho, Laurence; Clutton-Brock, Tim H; Duck, Callan; Edwards, Martin; Elliott, J Malcolm; Hall, Stephen J G; Harrington, Richard; Pearce-Higgins, James W; Høye, Toke T; Kruuk, Loeske E B; Pemberton, Josephine M; Sparks, Tim H; Thompson, Paul M; White, Ian; Winfield, Ian J; Wanless, Sarah

2016-07-14

Differences in phenological responses to climate change among species can desynchronise ecological interactions and thereby threaten ecosystem function. To assess these threats, we must quantify the relative impact of climate change on species at different trophic levels. Here, we apply a Climate Sensitivity Profile approach to 10,003 terrestrial and aquatic phenological data sets, spatially matched to temperature and precipitation data, to quantify variation in climate sensitivity. The direction, magnitude and timing of climate sensitivity varied markedly among organisms within taxonomic and trophic groups. Despite this variability, we detected systematic variation in the direction and magnitude of phenological climate sensitivity. Secondary consumers showed consistently lower climate sensitivity than other groups. We used mid-century climate change projections to estimate that the timing of phenological events could change more for primary consumers than for species in other trophic levels (6.2 versus 2.5-2.9 days earlier on average), with substantial taxonomic variation (1.1-14.8 days earlier on average).

Using Web-Based Questionnaires to Assess Medication Use During Pregnancy: A Validation Study in 2 Prospectively Enrolled Cohorts.

PubMed

van Gelder, Marleen M H J; Vorstenbosch, Saskia; Te Winkel, Bernke; van Puijenbroek, Eugène P; Roeleveld, Nel

2018-02-01

Medication use is often underreported in paper-based questionnaires or interviews. Web-based questionnaires may improve recall of medication use, but data on their validity are currently lacking. Participants in the Pregnancy and Infant Development (PRIDE) Study (2014-2016; n = 557) and the Pregnancy Drug Registry (pREGnant) (2015-2016; n = 169) completed a 6-week paper-based medication diary during gestational weeks 19-24 or 26-31. In week 34, they completed a Web-based questionnaire with questions on medication names, time period and frequency of use, and quantity taken. To assess the degree of underreporting, we calculated the questionnaire's sensitivity using the medication diary as the reference standard. Sensitivity was high for many medication groups, including antiepileptic medication (sensitivity (Sn) = 0.96, 95% confidence interval (CI): 0.89, 1.00), antacids (Sn = 0.89, 95% CI: 0.86, 0.93), and iron preparations (Sn = 0.81, 95% CI: 0.64, 0.98). However, medications for short-term use were underreported more frequently, with sensitivities of 0.54 (95% CI: 0.35, 0.72) for antihistamines, 0.63 (95% CI: 0.57, 0.69) for analgesic and antipyretic agents, and 0.57 (95% CI: 0.51, 0.64) for acetaminophen. Shortening the period of time between exposure and questionnaire administration increased sensitivity substantially. In conclusion, underreporting in Web-based questionnaires is limited for many medication groups. In prospective studies, underreporting of medications for short-term use may be reduced by decreasing the interval between consecutive questionnaires. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

MR imaging of silicone breast implants: evaluation of prospective and retrospective interpretations and interobserver agreement.

PubMed

Quinn, S F; Neubauer, N M; Sheley, R C; Demlow, T A; Szumowski, J

1996-01-01

MR imaging was used to evaluate the integrity of silicone breast implants in 54 women with 108 implants. MR images were interpreted by relatively inexperienced readers who tried to reproduce the experiences reported in the literature. The study examines the interobserver agreement using different diagnostic signs and the influence of experience on interpretation errors. Prospective and retrospective interpretations were compared with surgical findings at the time of explanation. Diagnostic indicators, including the linguine sign, the inverted tear drop sign, the C sign, water droplets mixed with silicone, and extracapsular globules of silicone, were evaluated for diagnostic efficacy and interobserver agreement. The prospective sensitivity and specificity were 87% and 78%, respectively. With the retrospective interpretations, the sensitivity and specificity increased to 93% and 92%, respectively. Most of the prospective false-positive interpretations were due to misinterpreting radial folds as signs of implant rupture. Six implants interpreted retrospectively as false positives had gross amounts of silicone around the implants at surgery but there were no obvious rents in the implant shells. There was fair to excellent interobserver agreement with the individual diagnostic signs except for extracapsular globules of silicone. All of the signs had specificities of greater than 90%. The sensitivities of the individual signs were less than the overall retrospective sensitivity. With experience, the sensitivity improved from 87% to 93% and the specificity improved from 78% to 92%. This study helps substantiate the use of diagnostic signs used by other authors to detect silicone loss from breast implants by MR imaging; however, questions remain as to the clinical role of MR imaging in evaluating implants for silicone loss.

Blind people are more sensitive than sighted people to binaural sound-location cues, particularly inter-aural level differences.

PubMed

Nilsson, Mats E; Schenkman, Bo N

2016-02-01

Blind people use auditory information to locate sound sources and sound-reflecting objects (echolocation). Sound source localization benefits from the hearing system's ability to suppress distracting sound reflections, whereas echolocation would benefit from "unsuppressing" these reflections. To clarify how these potentially conflicting aspects of spatial hearing interact in blind versus sighted listeners, we measured discrimination thresholds for two binaural location cues: inter-aural level differences (ILDs) and inter-aural time differences (ITDs). The ILDs or ITDs were present in single clicks, in the leading component of click pairs, or in the lagging component of click pairs, exploiting processes related to both sound source localization and echolocation. We tested 23 blind (mean age = 54 y), 23 sighted-age-matched (mean age = 54 y), and 42 sighted-young (mean age = 26 y) listeners. The results suggested greater ILD sensitivity for blind than for sighted listeners. The blind group's superiority was particularly evident for ILD-lag-click discrimination, suggesting not only enhanced ILD sensitivity in general but also increased ability to unsuppress lagging clicks. This may be related to the blind person's experience of localizing reflected sounds, for which ILDs may be more efficient than ITDs. On the ITD-discrimination tasks, the blind listeners performed better than the sighted age-matched listeners, but not better than the sighted young listeners. ITD sensitivity declines with age, and the equal performance of the blind listeners compared to a group of substantially younger listeners is consistent with the notion that blind people's experience may offset age-related decline in ITD sensitivity. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Capsule Performance Optimization in the National Ignition Campaign

DOE Office of Scientific and Technical Information (OSTI.GOV)

Landen, O L; MacGowan, B J; Haan, S W

2009-10-13

A capsule performance optimization campaign will be conducted at the National Ignition Facility to substantially increase the probability of ignition. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting themore » key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.« less