Laas, Enora; Lelong, Nathalie; Ancel, Pierre-Yves; Bonnet, Damien; Houyel, Lucile; Magny, Jean-François; Andrieu, Thibaut; Goffinet, François; Khoshnood, Babak
2017-05-15
Congenital heart defects (CHD) and preterm birth (PTB) are major causes of infant mortality. However, limited data exist on risk of mortality associated with PTB for newborns with CHD. Our objective was to assess impact of PTB on risk of infant mortality for newborns with CHD, while taking into account the role of associated anomalies and other potentially confounding factors. We used data on 2172 live births from a prospective population-based cohort study of CHD (the EPICARD Study) and compared neonatal, post-neonatal and overall infant mortality for infants born at <32, 32-34 and 35-36 weeks vs. those born at term (37-41 weeks). Preterm newborns had a 3.8-fold higher risk of infant death (17.9%) than term newborns (4.7%), RR 3.8, 95%CI 2.7-5.2; the risk associated with PTB was more than four-fold higher for neonatal (RR 4.3, 95% CI 2.9-6.6) and three-fold higher for post-neonatal deaths (RR 3.0, 95% CI 1.7-5.2). Survival analysis showed that newborns <35 weeks had a higher risk of mortality, which decreased but persisted after exclusion of associated anomalies and adjustment for potential confounders. Preterm birth is associated with an approximately four-fold higher risk of infant mortality for newborns with CHD. This excess risk appears to be mostly limited to newborns <35 weeks of gestation and is disproportionately due to early deaths.
Dietary intake and main sources of plant lignans in five European countries
Tetens, Inge; Turrini, Aida; Tapanainen, Heli; Christensen, Tue; Lampe, Johanna W.; Fagt, Sisse; Håkansson, Niclas; Lundquist, Annamari; Hallund, Jesper; Valsta, Liisa M.
2013-01-01
Background Dietary intakes of plant lignans have been hypothesized to be inversely associated with the risk of developing cardiovascular disease and cancer. Earlier studies were based on a Finnish lignan database (Fineli®) with two lignan precursors, secoisolariciresinol (SECO) and matairesinol (MAT). More recently, a Dutch database, including SECO and MAT and the newly recognized lignan precursors lariciresinol (LARI) and pinoresinol (PINO), was compiled. The objective was to re-estimate and re-evaluate plant lignan intakes and to identify the main sources of plant lignans in five European countries using the Finnish and Dutch lignan databases, respectively. Methods Forty-two food groups known to contribute to the total lignan intake were selected and attributed a value for SECO and MAT from the Finnish lignan database (Fineli®) or for SECO, MAT, LARI, and PINO from the Dutch database. Total intake of lignans was estimated from food consumption data for adult men and women (19–79 years) from Denmark, Finland, Italy, Sweden, United Kingdom, and the contribution of aggregated food groups calculated using the Dutch lignin database. Results Mean dietary lignan intakes estimated using the Dutch database ranged from 1 to 2 mg/day, which was approximately four-fold higher than the intakes estimated from the Fineli® database. When LARI and PINO were included in the estimation of the total lignan intakes, cereals, grain products, vegetables, fruit and berries were the most important dietary sources of lignans. Conclusion Total lignin intake was approximately four-fold higher in the Dutch lignin database, which includes the lignin precursors LARI and PINO, compared to estimates based on the Finnish database based only on SECO and MAT. The main sources of lignans according to the Dutch database in the five countries studied were cereals and grain products, vegetables, fruit, berries, and beverages. PMID:23766759
Evaluation of cationic liposomes composed of an amino acid-based lipid for neuronal transfection.
Obata, Yosuke; Ciofani, Gianni; Raffa, Vittoria; Cuschieri, Alfred; Menciassi, Arianna; Dario, Paolo; Takeoka, Shinji
2010-02-01
We investigated the ability of cationic liposomes composed of 1,5-dihexadecyl N-arginyl-L-glutamate (Arg-Glu2C(16)) to carry nucleic acids into neuronal cells. Such liposomes have been shown to have a remarkable capacity for transfecting immortalized cell lines. Lipoplexes between the Arg-Glu2C(16) liposomes and plasmid DNA encoding green fluorescent protein (GFP) were analyzed in terms of lipoplex formation, intracellular DNA trafficking, transfection efficiency, and cytotoxicity in neuronal SH-SY5Y cells. A maximum number of cells expressing GFP was obtained with lipoplexes at a lipid-to-DNA ratio of 15. With these lipoplexes, 16% of the cells were GFP-positive, which was approximately fourfold higher than the level obtained with a commercially available transfection reagent, Lipofectamine 2000. Furthermore, as a result of the low cytotoxicity of the Arg-Glu2C(16) lipoplexes, the proportion of GFP-positive cells could be increased to 25% by increasing the concentration of lipoplexes that was applied to the cells. We have demonstrated that Arg-Glu2C(16), as a model cationic amino acid-based lipid, has a high capability as a gene carrier, even for neuronal transfection. In this study, specific cationic liposomes were characterized as nucleic acid transfection agents for neuronal cells. A fourfold higher transfection rate with low cytotoxicity was reported compared to Lipofectamine 2000, a commercial reagent. The authors conclude that the studied cationic liposomes have a high capability as a gene carrier for neuronal transfection. This may become clinically significant in future gene therapy efforts of neuronal diseases. Copyright 2010 Elsevier Inc. All rights reserved.
Fungal melanins and their interactions with metals.
Fogarty, R V; Tobin, J M
1996-09-01
Fungal melanins are dark brown or black pigments located in cell walls. They also exist as extracellular polymers. Melanized fungi possess increased virulence and resistance to microbial attack as well as enhanced survival while under environmental stress. Melanins contain various functional groups which provide an array of multiple nonequivalent binding sites for metal ions. Pigmented Cladosporium cladosporoides was shown to biosorb 2.5- to four-fold more Ni, Cu, Zn, Cd, and Pb than albino Penicillium digitatum and at four- to six-fold higher rates. Metal desorption was significantly lower for extracellular melanin than from pigmented or albino biomass which indicated the strength of the melanin-metal bond. At equilibrium, tributyltin chloride (TBTC) concentrations of 2.5 mM, pigmented and albino Aureobasidium pullulans absorbed approximately 0.9 and 0.7 mumol TBTC mg -1 dry wt, respectively, whereas purified extracellular melanin exhibited uptake levels of approximately 22 mumol TBTC mg-1 dry wt at an equilibrium concentration of only 0.4 mM. Addition of melanin to the growth medium reduced the toxic effect of CuSO4 and TBTC due to melanin metal binding and sequestration.
Ochi, Arisa; Abe, Tomoki; Nakao, Reiko; Yamamoto, Yoriko; Kitahata, Kanako; Takagi, Marina; Hirasaka, Katsuya; Ohno, Ayako; Teshima-Kondo, Shigetada; Taesik, Gwag; Choi, Inho; Kawamura, Tomoyuki; Nemoto, Hisao; Mukai, Rie; Terao, Junji; Nikawa, Takeshi
2015-03-15
A DGpYMP peptide mimetic of tyrosine(608)-phosphorylated insulin receptor substrate-1 (IRS-1), named Cblin, was previously shown to significantly inhibit Cbl-b-mediated IRS-1 ubiquitination. In the present study, we developed N-myristoylated Cblin and investigated whether it was effective in preventing glucocorticoid-induced muscle atrophy. Using HEK293 cells overexpressing Cbl-b, IRS-1 and ubiquitin, we showed that the 50% inhibitory concentrations of Cbl-b-mediated IRS-1 ubiquitination by N-myristoylated Cblin and Cblin were 30 and 120 μM, respectively. Regarding the DEX-induced atrophy of C2C12 myotubes, N-myristoylated Cblin was more effective than Cblin for inhibiting the DEX-induced decreases in C2C12 myotube diameter and IRS-1 degradation. The inhibitory efficacy of N-myristoylated Cblin on IRS-1 ubiquitination in C2C12 myotubes was approximately fourfold larger than that of Cblin. Furthermore, N-myristoylation increased the incorporation of Cblin into HEK293 cells approximately 10-folds. Finally, we demonstrated that N-myristoylated Cblin prevented the wet weight loss, IRS-1 degradation, and MAFbx/atrogin-1 and MuRF-1 expression in gastrocnemius muscle of DEX-treated mice approximately fourfold more effectively than Cblin. Taken together, these results suggest that N-myristoylated Cblin prevents DEX-induced skeletal muscle atrophy in vitro and in vivo, and that N-myristoylated Cblin more effectively prevents muscle atrophy than unmodified Cblin. Copyright © 2015 Elsevier Inc. All rights reserved.
Holmes, E. W.; Hojvat, S. A.; Kahn, S. E.; Bermes, E. W.
1989-01-01
Biochemical correlates of neuroendocrine/gonadal function and nocturnal levels of serotonin N-acetyltransferase (NAT) activity were determined in partially nephrectomized (PNx), male, Long Evans rats following a 5-week period of chronic renal insufficiency (CRI). PNx animals demonstrated two to four-fold elevations in urea nitrogen and three to four-fold reductions (P less than 0.02) in plasma total testosterone concentrations as compared to sham-operated controls. The pituitary LH contents of PNx rats were decreased to approximately 60% of the control value (P less than 0.05). There were no differences in plasma prolactin levels between the control and PNx groups either at mid-day or in the middle of the night. Nocturnal pineal NAT activity in PNx rats was markedly reduced to approximately 20% of the control value (P less than 0.001). Similar evidence of gonadal dysfunction (reduced plasma total testosterone and testes testosterone content) and a significant decrease in night-time levels of pineal NAT activity were also observed after 13 weeks of CRI in PNx rats of the Sprague-Dawley strain that were housed under a different photoperiod. These results suggest that pineal gland dysfunction is a feature of CRI in the PNx model. Such an abnormality might contribute to the pathogenesis of gonadal dysfunction in CRI. PMID:2765391
Heavy metals in Antarctic ice from Law Dome: Initial results
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hong, S.; Boutron, C.F.; Edwards, R.
1998-08-01
Pb, Cd, Cu, and Zn have been measured using ultraclean procedures in eight sections taken from two well-dated ice cores from Law Dome, an independent small size ice cap with high accumulation rate situated in the coastal area of East Antarctica. Seven sections were dated from the 1830s to 1940s and one was dated from three millennia ago. The data show that there are strong seasonal variations in the concentrations of Pb and Cd, with values {approximately} two- to four-fold higher in winter than in spring-summer. Evaluation of the contributions from the different sources suggests that contribution from sea saltmore » spray is relatively important, especially for Cd. Contribution from marine biogenic emissions could also be very significant. The importance of marine contributions is consistent with strong intrusions of marine air masses at this coastal site, especially during wintertime.« less
Plants as sources of airborne bacteria, including ice nucleation-active bacteria.
Lindemann, J; Constantinidou, H A; Barchet, W R; Upper, C D
1982-11-01
Vertical wind shear and concentration gradients of viable, airborne bacteria were used to calculate the upward flux of viable cells above bare soil and canopies of several crops. Concentrations at soil or canopy height varied from 46 colony-forming units per m over young corn and wet soil to 663 colony-forming units per m over dry soil and 6,500 colony-forming units per m over a closed wheat canopy. In simultaneous samples, concentrations of viable bacteria in the air 10 m inside an alfalfa field were fourfold higher than those over a field with dry, bare soil immediately upwind. The upward flux of viable bacteria over alfalfa was three- to fourfold greater than over dry soil. Concentrations of ice nucleation-active bacteria were higher over plants than over soil. Thus, plant canopies may constitute a major source of bacteria, including ice nucleation-active bacteria, in the air.
NASA Astrophysics Data System (ADS)
Di Napoli, S.; Roura-Bas, P.; Weichselbaum, Andreas; Aligia, A. A.
2014-09-01
We calculate the differential conductance as a function of temperature and bias voltage, G (T,V), through Au monatomic chains with a substitutional Co atom as a magnetic impurity, connected to a fourfold symmetric lead. The system was recently proposed as a possible scenario for observation of the overscreened Kondo physics. Stretching the chain, the system could be tuned through a quantum critical point (QCP) with three different regimes: overscreened, underscreened, and non-Kondo phases. We present calculations of the impurity spectral function by using the numerical renormalization group for the three different regimes characterizing the QCP. Nontrivial behavior of the spectral function is reported near the QCP. Comparison with results using the noncrossing approximation (NCA) shows that the latter is reliable in the overscreened regime, when the anisotropy is larger than the Kondo temperature. For these parameters, which correspond to realistic previous estimates, G (T,V) calculated within NCA exhibits clear signatures of the non-Fermi-liquid behavior within the overscreened regime.
Networks with fourfold connectivity in two dimensions.
Tessier, Frédéric; Boal, David H; Discher, Dennis E
2003-01-01
The elastic properties of planar, C4-symmetric networks under stress and at nonzero temperature are determined by simulation and mean field approximations. Attached at fourfold coordinated junction vertices, the networks are self-avoiding in that their elements (or bonds) may not intersect each other. Two different models are considered for the potential energy of the elements: either Hooke's law springs or flexible tethers (square well potential). For certain ranges of stress and temperature, the properties of the networks are captured by one of several models: at large tensions, the networks behave like a uniform system of square plaquettes, while at large compressions or high temperatures, they display many characteristics of an ideal gas. Under less severe conditions, mean field models with more general shapes (parallelograms) reproduce many essential features of both networks. Lastly, the spring network expands without limit at a two-dimensional tension equal to the force constant of the spring; however, it does not appear to collapse under compression, except at zero temperature.
Probing the localization of magnetic dichroism by atomic-size astigmatic and vortex electron beams.
Negi, Devendra Singh; Idrobo, Juan Carlos; Rusz, Ján
2018-03-05
We report localization of a magnetic dichroic signal on atomic columns in electron magnetic circular dichroism (EMCD), probed by beam distorted by four-fold astigmatism and electron vortex beam. With astigmatic probe, magnetic signal to noise ratio can be enhanced by blocking the intensity from the central part of probe. However, the simulations show that for atomic resolution magnetic measurements, vortex beam is a more effective probe, with much higher magnetic signal to noise ratio. For all considered beam shapes, the optimal SNR constrains the signal detection at low collection angles of approximately 6-8 mrad. Irrespective of the material thickness, the magnetic signal remains strongly localized within the probed atomic column with vortex beam, whereas for astigmatic probes, the magnetic signal originates mostly from the nearest neighbor atomic columns. Due to excellent signal localization at probing individual atomic columns, vortex beams are predicted to be a strong candidate for studying the crystal site specific magnetic properties, magnetic properties at interfaces, or magnetism arising from individual atomic impurities.
Fu, Qian; Fukushima, Naoya; Maeda, Haruo; Sato, Kozo; Kobayashi, Hajime
2015-01-01
We examined whether a hyperthermophilic microbial fuel cell (MFC) would be technically feasible. Two-chamber MFC reactors were inoculated with subsurface microorganisms indigenous to formation water from a petroleum reservoir and were started up at operating temperature 80 °C. The MFC generated a maximum current of 1.3 mA 45 h after the inoculation. Performance of the MFC improved with an increase in the operating temperature; the best performance was achieved at 95 °C with the maximum power density of 165 mWm(-2), which was approximately fourfold higher than that at 75 °C. Thus, to our knowledge, our study is the first to demonstrate generation of electricity in a hyperthermophilic MFC (operating temperature as high as 95 °C). Scanning electron microscopy showed that filamentous microbial cells were attached on the anode surface. The anodic microbial consortium showed limited phylogenetic diversity and primarily consisted of hyperthermophilic bacteria closely related to Caldanaerobacter subterraneus and Thermodesulfobacterium commune.
Bandeira, Maria da C A; Brito, Gustavo A; da Penha, Adriane; Santos, Ciro L C; Rebêlo, José M M
2017-06-01
We investigated whether biting midges in peridomestic environments are affected by environmental management practices and the presence of domestic animals. We used CDC light traps to collect midges in 112 residences across 24 locations along tourism routes of Maranhão, Brazil. The collection areas were characterized as follows: i) peridomestic area with domestic animals and without management (dirty); ii) peridomestic with domestic animals and management (clean); iii) peridomestic without animals and with management (clean); iv) peridomestic without animals and without management (dirty). The first two treatments had higher biting midge species richness and abundance, respectively. Generalized linear models indicated a positive correlation between the presence of domestic animals and midge abundance, with an approximate four-fold increase in Culicoides (Diptera: Ceratopogonidae) abundance in peridomestic areas with animals. The same model showed that domestic animals have no influence on richness. Environmental management does not appear to influence species richness or abundance of biting midges. © 2017 The Society for Vector Ecology.
Kumar, G K; Kou, Y R; Overholt, J L; Prabhakar, N R
2000-01-01
Previously, we showed that carotid bodies express neutral endopeptidase (NEP)-like enzyme activity and that phosphoramidon, a potent inhibitor of NEP, potentiates the chemosensory response of the carotid body to hypoxia in vivo. NEP has been shown to hydrolyze methionine enkephalin (Met-Enk) and substance P (SP) in neuronal tissues. The purpose of the present study is to determine whether NEP hydrolyzes Met-Enk and SP in the carotid body and if so whether these peptides contribute to phosphoramidon-induced potentiation of the sensory response to hypoxia. Experiments were performed on carotid bodies excised from anesthetized adult cats (n = 72 carotid bodies). The hydrolysis of Met-Enk and SP was analyzed by HPLC. The results showed that both SP and Met-Enk were hydrolyzed by the carotid body, but the rate of Met-Enk hydrolysis was approximately fourfold higher than that of SP. Phosphoramidon (400 microM) markedly inhibited SP hydrolysis ( approximately 90%) but had only a marginal effect on Met-Enk hydrolysis ( approximately 15% inhibition). Hypoxia (PO(2), 68 +/- 6 Torr) as well as exogenous administration of SP (10 and 20 nmol) increased the sensory discharge of the carotid body in vitro. Sensory responses to hypoxia and SP (10 nmol) were potentiated by approximately 80 and approximately 275%, respectively (P < 0.01), in the presence of phosphoramidon. SP-receptor antagonists Spantide (peptidyl) and CP-96345 (nonpeptidyl) either abolished or markedly attenuated the phosphoramidon-induced potentiation of the sensory response of the carotid body to hypoxia as well as to SP. These results demonstrate that SP is a preferred substrate for NEP in the carotid body and that SP is involved in the potentiation of the hypoxic response of the carotid body by phosphoramidon.
Boyle, Seán; Petch, Jeremy; Batt, Kathy; Durand-Zaleski, Isabelle; Thomson, Sarah
2018-02-01
The main driver of higher spending on health care in the US is believed to be substantially higher fees paid to US physicians in comparison with other countries. We aim to compare physician incomes in radiology and oncology considering differences in relation to fees paid, physician capacity and volume of services provided in five countries: the United States, Canada, Australia, France and the United Kingdom. The fee for a consultation with a specialist in oncology varies threefold across countries, and more than fourfold for chemotherapy. There is also a three to fourfold variation in fees for ultrasound and CT scans. Physician earnings in the US are greater than in other countries in both oncology and radiology, more than three times higher than in the UK; Canadian oncologists and radiologists earn considerably more than their European counterparts. Although challenging, benchmarking earnings and fees for similar health care activities across countries, and understanding the factors that explain any differences, can provide valuable insights for policy makers trying to enhance efficiency and quality in service delivery, especially in the face of rising care costs. Copyright © 2017 Elsevier B.V. All rights reserved.
The Advanced Photovoltaic Solar Array (APSA) technology status and performance
NASA Technical Reports Server (NTRS)
Stella, Paul M.; Kurland, Richard M.
1991-01-01
In 1985, the Jet Propulsion Laboratory initiated the Advanced Photovoltaic Solar Array (APSA) program. The program objective is to demonstrate a producible array system by the early 1990s with a specific performance of at least 130 W/kG (beginning-of-life) as an intermediate milestone towards the long range goal of 300 W/kG. The APSA performance represents an approximately four-fold improvement over existing rigid array technology and a doubling of the performance of the first generation NASA/OAST SAFE flexible blanket array of the early 1980s.
Vertex stability and topological transitions in vertex models of foams and epithelia
NASA Astrophysics Data System (ADS)
Spencer, Meryl; Jabeen, Zahera; Lubensky, David
Vertex models are widely used to computationally simulate dry foams and epithelial tissues. This class of models describes the shape and motion of cells as a function of the forces on vertices where 3 or more cells meet. Despite the widespread use of these models, relatively little is known about their basic theoretical properties. One outstanding issue is the stability of fourfold vertices. In real foams, fourfold vertices are always unstable, but it has been unclear whether vertex models necessarily reflect this behavior. In biological tissues, fourfold vertices arise as an intermediate in T1 transitions, which are one of the fundamental processes by which tissues change topology, and stable fourfold vertices have recently been observed in several different epithelia. We show that, when all edges have the same tension, stationary fourfold vertices in vertex models must always break up. However, when tensions depend on edge orientation, as they might in a planar-polarized tissue, fourfold vertices can become stable. These findings pave the way for studies of more biologically realistic models that couple topological transitions to the dynamics of regulatory proteins. NSF Grant No. DMR-1056456 and NSF-GRFP Grant No. DGE-1256260.
High-dose HOOK effect in urinary DcR2 assay in patients with chronic kidney disease.
Chen, Jia; Chen, Ke-Hong; Wang, Li-Ming; Zhang, Wei-Wei; Feng, Lei; Dai, Huan-Zi; He, Ya-Ni
2018-06-05
Urinary DcR2 (uDcR2) is a biomarker for the early detection the tubulointerstitial injury (TII) in patients with chronic kidney disease (CKD), but the high-dose hook effect may lead to falsely low or even negative results when using an enzyme-linked immunosorbent assay (ELISA). This study aimed to investigate if the high-dose hook effect exists with ELISA testing, and to uncover a potential approach for reducing this effect. 72 CKD patients were recruited and categorized into four groups based on TII scores. uDcR2 was measured in undiluted and serially diluted (two-, four-, eight- and 16-fold dilutions) urine using an ELISA kit. The results from the assay were normalized to urinary creatinine. We evaluated the correlation between uDcR2/cre levels at different dilutions and renal histological parameters. Receiver operating characteristic (ROC) curves were generated to examine the value of uDcR2/cre for predicting TII. uDcR2/cre levels in the undiluted urine were significantly higher in patients with CKD than those in the control. However, higher TII scores did not yield higher levels of uDcR2/cre in the undiluted urine. After serial dilution, uDcR2/cre levels were highest with the four-fold dilution. A positive correlation was found between uDcR2/cre levels at different dilutions and TII scores, with the highest correlation coefficient and the largest AUC being observed at the four-fold dilution. The high-dose hook effect was apparent during ELISA testing of uDcR2 in CKD patients, yet dilution of the urine samples neutralized this effect. However, the use of a four-fold dilution of urine for uDcR2/cre testing may eliminate the high-dose hook effect and make it possible to effectively monitor the severity of TII in CKD patients. Copyright © 2018. Published by Elsevier Inc.
All complete intersection Calabi-Yau four-folds
NASA Astrophysics Data System (ADS)
Gray, James; Haupt, Alexander S.; Lukas, Andre
2013-07-01
We present an exhaustive, constructive, classification of the Calabi-Yau four-folds which can be described as complete intersections in products of projective spaces. A comprehensive list of 921,497 configuration matrices which represent all topologically distinct types of complete intersection Calabi-Yau four-folds is provided and can be downloaded from http://www-thphys.physics.ox.ac.uk/projects/CalabiYau/Cicy4folds/index.html. The manifolds have non-negative Euler characteristics in the range 0 ≤ χ ≤ 2610. This data set will be of use in a wide range of physical and mathematical applications. Nearly all of these four-folds are elliptically fibered and are thus of interest for F-theory model building.
Kerger, Brent D; Suder, David R; Schmidt, Chuck E; Paustenbach, Dennis J
2005-03-26
This study evaluates airborne concentrations of common trihalomethane compounds (THM) in selected living spaces of homes supplied with chlorinated tap water containing >85 ppb total THM. Three small homes in an arid urban area were selected, each having three bedrooms, a full bath, and approximately 1000 square feet; two homes had standard (refrigeration-type) central air conditioning and the third had a central evaporative cooling system ("swamp cooler"). A high-end water-use pattern was used at each home in this exposure simulation. THM were concurrently measured on 4 separate test days in tap water and air in the bathroom, living room, the bedroom closest to the bathroom, and outside using Summa canisters. Chloroform (trichloromethane, TCM), bromodichloromethane (BDCM), and dibromochloromethane (DBCM) concentrations were quantified using U.S. EPA Method TO-14. The apparent volatilization fraction consistently followed the order: TCM > BDCM > DBCM. Relatively low airborne THM concentrations (similar to outdoors) were found in the living room and bedroom samples for the home with evaporative cooling, while the refrigeration-cooled homes showed significantly higher THM levels (three- to fourfold). This differential remained after normalizing the air concentrations based on estimated THM throughput or water concentrations. These findings indicate that, despite higher throughput of THM-containing water in homes using evaporative coolers, the higher air exchange rates associated with these systems rapidly clears THM to levels similar to ambient outdoor concentrations.
Different profiles of carcinogen exposure in Chinese compared with US cigarette smokers.
Benowitz, Neal L; Gan, Quan; Goniewicz, Maciej L; Lu, Wei; Xu, Jiying; Li, Xinjian; Jacob, Peyton; Glantz, Stanton
2015-12-01
Differences in carcinogen exposure from different cigarette products could contribute to differences in smoking-associated cancer incidence among Chinese compared with US smokers. Urine concentrations of metabolites of nicotine, the tobacco-specific nitrosamine (TSNA) 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and polycyclic aromatic hydrocarbon metabolites (PAHs) were compared in 238 Chinese and 203 US daily smokers. Comparing Chinese versus US smokers, daily nicotine intake and nicotine intake per cigarette smoked were found to be similar. When normalised for cigarettes per day, urine NNAL excretion was fourfold higher in US smokers, while the excretion of urine metabolites of the PAHs fluorene, phenanthrene and pyrene metabolites was 50% to fourfold higher in Chinese smokers (all, p<0.0001). Similar results were seen when NNAL and PAHs excretion was normalised for daily nicotine intake. Patterns of carcinogen exposure differ, with lower exposure to TSNA and higher exposure to PAHs in Chinese compared with US smokers. These results most likely reflect country differences in cigarette tobacco blends and manufacturing processes, as well as different environmental exposures. NCT00264342. 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/
Muju virus, a novel hantavirus harboured by the arvicolid rodent Myodes regulus in Korea
Song, Ki-Joon; Baek, Luck Ju; Moon, Sungsil; Ha, Si Jung; Kim, Sang Hyun; Park, Kwang Sook; Klein, Terry A.; Sames, William; Kim, Heung-Chul; Lee, John S.; Yanagihara, Richard; Song, Jin-Won
2008-01-01
Acute-phase sera from >5 % of cases of haemorrhagic fever with renal syndrome occurring annually in Korea have been found to exhibit a fourfold or higher antibody titre to Puumala virus (PUUV) than to Hantaan virus (HTNV) by double-sandwich IgM ELISA, suggesting the existence of a PUUV-related hantavirus. Based on the phylogenetic relationships among arvicolid rodents, the royal vole (Myodes regulus) was targeted as a likely reservoir host of hantavirus. Using RT-PCR, a genetically distinct hantavirus, designated Muju virus (MUJV), was detected in lung tissue of royal voles, captured in widely separated geographical regions in Korea during 1996–2007. Pairwise analysis of the full-length S (1857 nt) and M (3634 nt) segments of MUJV indicated approximately 77 % sequence similarity with PUUV. At the amino acid level, MUJV differed from PUUV by 5.5–6.9 % (nucleocapsid) and 10.0–11.6 % (Gn and Gc envelope glycoproteins). Interstrain variation of MUJV sequences from royal voles captured in different regions suggested geographic-specific clustering. Neutralizing antibody titres against PUUV were two- to sixfold higher than to HTNV in sera of MUJV-infected Myodes regulus. Although virus isolation attempts were unsuccessful, the collective data indicate that MUJV is a distinct hantavirus species. PMID:17947538
Probing the localization of magnetic dichroism by atomic-size astigmatic and vortex electron beams
Negi, Devendra Singh; Idrobo, Juan Carlos; Rusz, Ján
2018-03-05
We report localization of a magnetic dichroic signal on atomic columns in electron magnetic circular dichroism (EMCD), probed by beam distorted by four-fold astigmatism and electron vortex beam. With astigmatic probe, magnetic signal to noise ratio can be enhanced by blocking the intensity from the central part of probe. However, the simulations show that for atomic resolution magnetic measurements, vortex beam is a more effective probe, with much higher magnetic signal to noise ratio. For all considered beam shapes, the optimal SNR constrains the signal detection at low collection angles of approximately 6–8 mrad. Irrespective of the material thickness, themore » magnetic signal remains strongly localized within the probed atomic column with vortex beam, whereas for astigmatic probes, the magnetic signal originates mostly from the nearest neighbor atomic columns. Due to excellent signal localization at probing individual atomic columns, vortex beams are predicted to be a strong candidate for studying the crystal site specific magnetic properties, magnetic properties at interfaces, or magnetism arising from individual atomic impurities.« less
Probing the localization of magnetic dichroism by atomic-size astigmatic and vortex electron beams
DOE Office of Scientific and Technical Information (OSTI.GOV)
Negi, Devendra Singh; Idrobo, Juan Carlos; Rusz, Ján
We report localization of a magnetic dichroic signal on atomic columns in electron magnetic circular dichroism (EMCD), probed by beam distorted by four-fold astigmatism and electron vortex beam. With astigmatic probe, magnetic signal to noise ratio can be enhanced by blocking the intensity from the central part of probe. However, the simulations show that for atomic resolution magnetic measurements, vortex beam is a more effective probe, with much higher magnetic signal to noise ratio. For all considered beam shapes, the optimal SNR constrains the signal detection at low collection angles of approximately 6–8 mrad. Irrespective of the material thickness, themore » magnetic signal remains strongly localized within the probed atomic column with vortex beam, whereas for astigmatic probes, the magnetic signal originates mostly from the nearest neighbor atomic columns. Due to excellent signal localization at probing individual atomic columns, vortex beams are predicted to be a strong candidate for studying the crystal site specific magnetic properties, magnetic properties at interfaces, or magnetism arising from individual atomic impurities.« less
Ijumba, J N; Mosha, F W; Lindsay, S W
2002-03-01
Malaria vector Anopheles and other mosquitoes (Diptera: Culicidae) were monitored for 12 months during 1994-95 in villages of Lower Moshi irrigation area (37 degrees 20' E, 3 degrees 21' S; approximately 700 m a.s.l.) south of Mount Kilimanjaro in northern Tanzania. Adult mosquito populations were sampled fortnightly by five methods: human bait collection indoors (18.00-06.00 hours) and outdoors (18.00-24.00 hours); from daytime resting-sites indoors and outdoors; by CDC light-traps over sleepers. Anopheles densities and rates of survival, anthropophily and malaria infection were compared between three villages representing different agro-ecosystems: irrigated sugarcane plantation; smallholder rice irrigation scheme, and savannah with subsistence crops. Respective study villages were Mvuleni (population 2200), Chekereni (population 3200) and Kisangasangeni (population approximately/= 1000), at least 7 km apart. Anopheles arabiensis Patton was found to be the principal malaria vector throughout the study area, with An. funestus Giles sensu lato of secondary importance in the sugarcane and savannah villages. Irrigated sugarcane cultivation resulted in water pooling, but this did not produce more vectors. Anopheles arabiensis densities averaged four-fold higher in the ricefield village, although their human blood-index was significantly less (48%) than in the sugarcane (68%) or savannah (66%) villages, despite similar proportions of humans and cows (ratio 1:1.1-1.4) as the main hosts at all sites. Parous rates, duration of the gonotrophic cycle and survival rates of An. arabiensis were similar in villages of all three agro-ecosystems. The potential risk of malaria, based on measurements of vectorial capacity of An. arabiensis and An.funestus combined, was four-fold higher in the ricefield village than in the sugarcane or savannah villages nearby. However, the more realistic estimate of malaria risk, based on entomological inoculation rates, indicated that exposure to infective vectors was 61-68% less for people in the ricefield village, due to the much lower sporozoite rate in An. arabiensis (ricefield 0.01%, sugarcane 0.1%, savannah 0.12%). This contrast was attributed to better socio-economic conditions of rice farmers, facilitating relatively more use of antimalarials and bednets for their families. Our findings show that, for a combination of reasons, the malaria challenge is lower for villagers associated with an irrigated rice-growing scheme (despite greater malaria vector potential), than for adjacent communities with other agro-ecosystems bringing less socio-economic benefits to health. This encourages the development of agro-irrigation schemes in African savannahs, provided that residents have ready access to antimalaria materials (i.e. effective antimalaria drugs and insecticidal bednets) that they may better afford for protection against the greater vectorial capacity of An. arabiensis from the ricefield agro-ecosystem.
NASA Astrophysics Data System (ADS)
Liu, R. M.; Zhuo, W. Z.; Chen, J.; Qin, M. H.; Zeng, M.; Lu, X. B.; Gao, X. S.; Liu, J.-M.
2017-07-01
We study the thermal phase transition of the fourfold degenerate phases (the plaquette and single-stripe states) in the two-dimensional frustrated Ising model on the Shastry-Sutherland lattice using Monte Carlo simulations. The critical Ashkin-Teller-like behavior is identified both in the plaquette phase region and the single-stripe phase region. The four-state Potts critical end points differentiating the continuous transitions from the first-order ones are estimated based on finite-size-scaling analyses. Furthermore, a similar behavior of the transition to the fourfold single-stripe phase is also observed in the anisotropic triangular Ising model. Thus, this work clearly demonstrates that the transitions to the fourfold degenerate states of two-dimensional Ising antiferromagnets exhibit similar transition behavior.
Sousa, Ana Célia; Mendonça, Maria I; Pereira, Andreia; Gouveia, Sara; Freitas, Ana I; Guerra, Graça; Rodrigues, Mariana; Henriques, Eva; Freitas, Sónia; Borges, Sofia; Pereira, Décio; Brehm, António; Palma Dos Reis, Roberto
2017-10-01
Essential hypertension (EH) is a disease in which both environment and genes have an important role. This study was designed to identify the interaction model between genetic variants and environmental risk factors that most highly potentiates EH development. We performed a case-control study with 1641 participants (mean age 50.6 ± 8.1 years), specifically 848 patients with EH and 793 controls, adjusted for gender and age. Traditional risk factors, biochemical and genetic parameters, including the genotypic discrimination of 14 genetic variants previously associated with EH, were investigated. Multifactorial dimensionality reduction (MDR) software was used to analyze gene-environment interactions. Validation was performed using logistic regression analysis with environmental risk factors, significant genetic variants, and the best MDR model. The best model indicates that the interactions among the ADD1 rs4961 640T allele, diabetes, and obesity (body mass index ≥30) increase approximately four-fold the risk of EH (odds ratio = 3.725; 95% confidence interval: 2.945-4.711; p < 0.0001). This work showed that the interaction between the ADD1 rs4961 variant, obesity, and the presence of diabetes increased the susceptibility to EH four-fold. In these circumstances, lifestyle adjustment and diabetes control should be intensified in patients who carry the ADD1 variant.
Impulsive EUV bursts observed in C IV with OSO-8. [UV solar spectra
NASA Technical Reports Server (NTRS)
Athay, R. G.; White, O. R.; Lites, B. W.; Bruner, E. C., Jr.
1980-01-01
Time sequences of profiles of the 1548 A line of C IV containing 51 EUV bursts observed in or near active regions are analyzed to determine the brightness, Doppler shift and line broadening characteristics of the bursts. The bursts have mean lifetimes of approximately 150 s, and mean increases in brightness at burst maximum of four-fold as observed with a field of view of 2 x 20 arc sec. Mean burst diameters are estimated to be 3 arc sec, or smaller. All but three of the bursts show Doppler shifts with velocities sometimes exceeding 75 km/s; 31 are dominated by red shifts and 17 are dominated by blue shifts. Approximately half of the latter group have red-shifted precursors. The bursts are interpreted as prominence material, such as surges and coronal rain, moving through the field of view of the spectrometer.
Beyond sixfold coordinated Si in SiO2 glass at ultrahigh pressures
Prescher, Clemens; Prakapenka, Vitali B.; Stefanski, Johannes; Jahn, Sandro; Skinner, Lawrie B.; Wang, Yanbin
2017-01-01
We investigated the structure of SiO2 glass up to 172 GPa using high-energy X-ray diffraction. The combination of a multichannel collimator with diamond anvil cells enabled the measurement of structural changes in silica glass with total X-ray diffraction to previously unachievable pressures. We show that SiO2 first undergoes a change in Si–O coordination number from fourfold to sixfold between 15 and 50 GPa, in agreement with previous investigations. Above 50 GPa, the estimated coordination number continuously increases from 6 to 6.8 at 172 GPa. Si–O bond length shows first an increase due to the fourfold to sixfold coordination change and then a smaller linear decrease up to 172 GPa. We reconcile the changes in relation to the oxygen-packing fraction, showing that oxygen packing decreases at ultrahigh pressures to accommodate the higher than sixfold Si–O coordination. These results give experimental insight into the structural changes of silicate glasses as analogue materials for silicate melts at ultrahigh pressures. PMID:28874582
Beyond sixfold coordinated Si in SiO2 glass at ultrahigh pressures.
Prescher, Clemens; Prakapenka, Vitali B; Stefanski, Johannes; Jahn, Sandro; Skinner, Lawrie B; Wang, Yanbin
2017-09-19
We investigated the structure of SiO 2 glass up to 172 GPa using high-energy X-ray diffraction. The combination of a multichannel collimator with diamond anvil cells enabled the measurement of structural changes in silica glass with total X-ray diffraction to previously unachievable pressures. We show that SiO 2 first undergoes a change in Si-O coordination number from fourfold to sixfold between 15 and 50 GPa, in agreement with previous investigations. Above 50 GPa, the estimated coordination number continuously increases from 6 to 6.8 at 172 GPa. Si-O bond length shows first an increase due to the fourfold to sixfold coordination change and then a smaller linear decrease up to 172 GPa. We reconcile the changes in relation to the oxygen-packing fraction, showing that oxygen packing decreases at ultrahigh pressures to accommodate the higher than sixfold Si-O coordination. These results give experimental insight into the structural changes of silicate glasses as analogue materials for silicate melts at ultrahigh pressures.
Knudson, M D; Hanson, D L; Bailey, J E; Hall, C A; Asay, J R
2003-01-24
A novel approach was developed to probe density compression of liquid deuterium (L-D2) along the principal Hugoniot. Relative transit times of shock waves reverberating within the sample are shown to be sensitive to the compression due to the first shock. This technique has proven to be more sensitive than the conventional method of inferring density from the shock and mass velocity, at least in this high-pressure regime. Results in the range of 22-75 GPa indicate an approximately fourfold density compression, and provide data to differentiate between proposed theories for hydrogen and its isotopes.
Mouse Model for Human Arginase Deficiency
Iyer, Ramaswamy K.; Yoo, Paul K.; Kern, Rita M.; Rozengurt, Nora; Tsoa, Rosemarie; O'Brien, William E.; Yu, Hong; Grody, Wayne W.; Cederbaum, Stephen D.
2002-01-01
Deficiency of liver arginase (AI) causes hyperargininemia (OMIM 207800), a disorder characterized by progressive mental impairment, growth retardation, and spasticity and punctuated by sometimes fatal episodes of hyperammonemia. We constructed a knockout mouse strain carrying a nonfunctional AI gene by homologous recombination. Arginase AI knockout mice completely lacked liver arginase (AI) activity, exhibited severe symptoms of hyperammonemia, and died between postnatal days 10 and 14. During hyperammonemic crisis, plasma ammonia levels of these mice increased >10-fold compared to those for normal animals. Livers of AI-deficient animals showed hepatocyte abnormalities, including cell swelling and inclusions. Plasma amino acid analysis showed the mean arginine level in knockouts to be approximately fourfold greater than that for the wild type and threefold greater than that for heterozygotes; the mean proline level was approximately one-third and the ornithine level was one-half of the proline and ornithine levels, respectively, for wild-type or heterozygote mice—understandable biochemical consequences of arginase deficiency. Glutamic acid, citrulline, and histidine levels were about 1.5-fold higher than those seen in the phenotypically normal animals. Concentrations of the branched-chain amino acids valine, isoleucine, and leucine were 0.4 to 0.5 times the concentrations seen in phenotypically normal animals. In summary, the AI-deficient mouse duplicates several pathobiological aspects of the human condition and should prove to be a useful model for further study of the disease mechanism(s) and to explore treatment options, such as pharmaceutical administration of sodium phenylbutyrate and/or ornithine and development of gene therapy protocols. PMID:12052859
Sodium-hydrogen exchange in erythrocytes of patients with acute deep venous thromboses.
Polykarpov, S A; Orlov, S N
1992-05-15
The rate of delta microH(+)-induced Na/H-exchange in erythrocytes of patients with occlusive and with floating types of acute deep venous thromboses, and in control volunteers, was estimated. In patients with occlusive thrombi Na/H-exchange was revealed to be fourfold higher in comparison with patients with floating thrombi and with controls, while no difference was observed between the two latter groups.
Latent manganese deficiency increases transpiration in barley (Hordeum vulgare).
Hebbern, Christopher A; Laursen, Kristian Holst; Ladegaard, Anne H; Schmidt, Sidsel B; Pedas, Pai; Bruhn, Dan; Schjoerring, Jan K; Wulfsohn, Dvoralai; Husted, Søren
2009-03-01
To investigate if latent manganese (Mn) deficiency leads to increased transpiration, barley plants were grown for 10 weeks in hydroponics with daily additions of Mn in the low nM range. The Mn-starved plants did not exhibit visual leaf symptoms of Mn deficiency, but Chl a fluorescence measurements revealed that the quantum yield efficiency of PSII (F(v)/F(m)) was reduced from 0.83 in Mn-sufficient control plants to below 0.5 in Mn-starved plants. Leaf Mn concentrations declined from 30 to 7 microg Mn g(-1) dry weight in control and Mn-starved plants, respectively. Mn-starved plants had up to four-fold higher transpiration than control plants. Stomatal closure and opening upon light/dark transitions took place at the same rate in both Mn treatments, but the nocturnal leaf conductance for water vapour was still twice as high in Mn-starved plants compared with the control. The observed increase in transpiration was substantiated by (13)C-isotope discrimination analysis and gravimetric measurement of the water consumption, showing significantly lower water use efficiency in Mn-starved plants. The extractable wax content of leaves of Mn-starved plants was approximately 40% lower than that in control plants, and it is concluded that the increased leaf conductance and higher transpirational water loss are correlated with a reduction in the epicuticular wax layer under Mn deficiency.
Ntuk, U E; Celis-Morales, C A; Mackay, D F; Sattar, N; Pell, J P; Gill, J M R
2017-08-01
To quantify the extent to which ethnic differences in muscular strength might account for the substantially higher prevalence of diabetes in black and South-Asian compared with white European adults. This cross-sectional study used baseline data from the UK Biobank study on 418 656 white European, black and South-Asian participants, aged 40-69 years, who had complete data on diabetes status and hand-grip strength. Associations between hand-grip strength and diabetes were assessed using logistic regression and were adjusted for potential confounding factors. Lower grip strength was associated with higher prevalence of diabetes, independent of confounding factors, across all ethnicities in both men and women. Diabetes prevalence was approximately three- to fourfold higher in South-Asian and two- to threefold higher in black participants compared with white European participants across all levels of grip strength, but grip strength in South-Asian men and women was ~ 5-6 kg lower than in the other ethnic groups. Thus, the attributable risk for diabetes associated with low grip strength was substantially higher in South-Asian participants (3.9 and 4.2 cases per 100 men and women, respectively) than in white participants (2.0 and 0.6 cases per 100 men and women, respectively). Attributable risk associated with low grip strength was also high in black men (4.3 cases) but not in black women (0.4 cases). Low strength is associated with a disproportionately large number of diabetes cases in South-Asian men and women and in black men. Trials are needed to determine whether interventions to improve strength in these groups could help reduce ethnic inequalities in diabetes prevalence. © 2017 Diabetes UK.
Mishra, A; Mishra, S C
2016-04-01
The occurrence of juvenile nasopharyngeal angiofibroma is reportedly higher in India than in some other parts of the world, and our centre has seen a four-fold increase in its occurrence across seven decades. This paper reports a retrospective archival analysis of 701 juvenile nasopharyngeal angiofibroma cases from 1958 to 2013, and considers probable environmental factors in an Indian context that may affect its biology and the global distribution, as reported in the literature. A continuously progressive increase in occurrence was evident, but the rapid rise observed in the current decade was alarming. The world map of juvenile nasopharyngeal angiofibroma incidence does not reflect true global distribution given the paucity of reporting. Our centre has dealt with approximately 400 cases in the last 24 years. With the alarming increase in juvenile nasopharyngeal angiofibroma incidence, there is a need for a registry to define its epidemiology. The world literature needs to reflect the status of juvenile nasopharyngeal angiofibroma incidence in the third world as well. Environmental factors known for hormone disruptive actions may influence its occurrence. Such aspects need to be considered to plan specific prevention policies.
Suh, Young-Ger; Kim, Sun Nam; Shin, Dong-Yun; Hyun, Soon-Sil; Lee, Do-Sang; Min, Kyung-Hoon; Han, Sae Mi; Li, Funan; Choi, Eung-Chil; Choi, Seong-Hak
2006-01-01
For the systematic SAR study on mansonone F, a series of C6 and C9 analogs of mansonone F have been synthesized and their anti-MRSA activities were evaluated. Most of the analogs exhibited good or excellent anti-MRSA activities. In particular, the 6-n-butylmansonone F showed fourfold higher antibacterial activities compared to that of vancomycin.
Whalen, Katie L; Chau, Anthony C; Spies, M Ashley
2013-10-01
A novel lead compound for inhibition of the antibacterial drug target, glutamate racemase (GR), was optimized for both ligand efficiency and lipophilic efficiency. A previously developed hybrid molecular dynamics-docking and scoring scheme, FERM-SMD, was used to predict relative potencies of potential derivatives prior to chemical synthesis. This scheme was successful in distinguishing between high- and low-affinity binders with minimal experimental structural information, saving time and resources in the process. In vitro potency was increased approximately fourfold against GR from the model organism, B. subtilis. Lead derivatives show two- to fourfold increased antimicrobial potency over the parent scaffold. In addition, specificity toward B. subtilis over E. coli and S. aureus depends on the substituent added to the parent scaffold. Finally, insight was gained into the capacity for these compounds to reach the target enzyme in vivo using a bacterial cell wall lysis assay. The outcome of this study is a novel small-molecule inhibitor of GR with the following characteristics: Ki=2.5 μM, LE=0.45 kcal mol(-1) atom(-1), LiPE=6.0, MIC50=260 μg mL(-1) against B. subtilis, EC50, lysis=520 μg mL(-1) against B. subtilis. Copyright © 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.
Pressure recovery performance of conical diffusers at high subsonic Mach numbers
NASA Technical Reports Server (NTRS)
Dolan, F. X.; Runstadler, P. W., Jr.
1973-01-01
The pressure recovery performance of conical diffusers has been measured for a wide range of geometries and inlet flow conditions. The approximate level and location (in terms of diffuser geometry of optimum performance were determined. Throat Mach numbers from low subsonic (m sub t equals 0.2) through choking (m sub t equals 1.0) were investigated in combination with throat blockage from 0.03 to 0.12. For fixed Mach number, performance was measured over a fourfold range of inlet Reynolds number. Maps of pressure recovery are presented as a function of diffuser geometry for fixed sets of inlet conditions. The influence of inlet blockage, throat Mach number, and inlet Reynolds number is discussed.
First Scientific Working Group Meeting of Airborne Doppler Lidar Wind Velocity Measurement Program
NASA Technical Reports Server (NTRS)
Kaufman, J. W. (Editor)
1980-01-01
The purpose of the first scientific working group meeting was fourfold: (1) to identify flight test options for engineering verification of the MSFC Doppler Lidar; (2) to identify flight test options for gathering data for scientific/technology applications; (3) to identify additional support equipment needed on the CV 990 aircraft for the flight tests; and (4) to identify postflight data processing and data sets requirements. The working group identified approximately ten flight options for gathering data on atmospheric dynamics processes, including turbulence, valley breezes, and thunderstorm cloud anvil and cold air outflow dynamics. These test options will be used as a basis for planning the fiscal year 1981 tests of the Doppler Lidar system.
DOE Office of Scientific and Technical Information (OSTI.GOV)
K.-F. Braun, V. Iancu, N. Pertaya, K.-H. Rieder and S.-W. Hla
Deviating from the common growth mode of molecular films of organic molecules where the adsorbates remain intact, we observe an essentially different growth behavior for metalocenes with a low temperature scanning tunneling microscope. Ferrocene molecules adsorb dissociatively and form a two layer structure after being decomposed into fragments. The toplayer unit cell is composed of two tilted cyclopentadienyl rings, while the first layer consists of the remaining fragments. Surprisingly a fourfold symmetry is observed for the top layer while the first layer displays threefold symmetry elements. It is this symmetry mismatch which induces an incommensurability between these layers in allmore » except one surface direction. The toplayer is weakly bonded and has an antiferromagnetic groundstate as calculated by local spin density functional approximation.« less
Petridou, N; Italiaander, M; van de Bank, B L; Siero, J C W; Luijten, P R; Klomp, D W J
2013-01-01
Recent studies have shown that functional MRI (fMRI) can be sensitive to the laminar and columnar organization of the cortex based on differences in the spatial and temporal characteristics of the blood oxygenation level-dependent (BOLD) signal originating from the macrovasculature and the neuronal-specific microvasculature. Human fMRI studies at this scale of the cortical architecture, however, are very rare because the high spatial/temporal resolution required to explore these properties of the BOLD signal are limited by the signal-to-noise ratio. Here, we show that it is possible to detect BOLD signal changes at an isotropic spatial resolution as high as 0.55 mm at 7 T using a high-density multi-element surface coil with minimal electronics, which allows close proximity to the head. The coil comprises of very small, 1 × 2-cm(2) , elements arranged in four flexible modules of four elements each (16-channel) that can be positioned within 1 mm from the head. As a result of this proximity, tissue losses were five-fold greater than coil losses and sufficient to exclude preamplifier decoupling. When compared with a standard 16-channel head coil, the BOLD sensitivity was approximately 2.2-fold higher for a high spatial/temporal resolution (1 mm isotropic/0.4 s), multi-slice, echo planar acquisition, and approximately three- and six-fold higher for three-dimensional echo planar images acquired with isotropic resolutions of 0.7 and 0.55 mm, respectively. Improvements in parallel imaging performance (geometry factor) were up to around 1.5-fold with increasing acceleration factor, and improvements in fMRI detectability (temporal signal-to-noise ratio) were up to around four-fold depending on the distance to the coil. Although deeper lying structures may not benefit from the design, most fMRI questions pertain to the neocortex which lies within approximately 4 cm from the surface. These results suggest that the resolution of fMRI (at 7 T) can approximate levels that are closer to the spatial/temporal scale of the fundamental functional organization of the human cortex using a simple high-density coil design for high sensitivity. Copyright © 2012 John Wiley & Sons, Ltd.
Four-Fold Prevention: Strategies To Prevent Substance Abuse among Elementary School-Aged Children.
ERIC Educational Resources Information Center
Coker, J. Kelly
2001-01-01
Article describes a substance-abuse prevention program, Four-Fold Prevention, designed to specifically focus on four primary areas of social support-parents, schools, communities, and peers. This program enhances positive and supportive relationships among children and influencing adults and peers by opening the lines of communication about…
Magnetic field characteristics of electric bed-heating devices.
Wilson, B W; Lee, G M; Yost, M G; Davis, K C; Heimbigner, T; Buschbom, R L
1996-01-01
Measurements of the flux density and spectra of magnetic fields (MFs) generated by several types of electric bed heaters (EBH) were made in order to characterize the MFs to which the fetus may be exposed in utero from the mother's use of these devices. Data on MPs were gathered from more than 1,300 in-home and laboratory spot measurements. In-home measurements taken at seven different positions 10 cm from the EBHs determined that the mean flux density at the estimated position of the fetus relative to the device was 0.45 microT (4.5 mG) for electric blankets and 0.20 microT (2.0 mG) for electrically heated water beds. A rate-of-change (RC) metric applied to the nighttime segment of 24 h EMDEX-C personal-dosimeter measurements, which were taken next to the bed of volunteers, yielded an approximate fourfold to sixfold higher value for electric blanket users compared to water-bed heater users. These same data records yielded an approximate twofold difference for the same measurements when evaluated by the time-weighted-average (TWA)MF exposure metric. Performance of exposure meters was checked against standard fields generated in the laboratory, and studies of sources of variance in the in-home measurement protocols were carried out. Spectral measurements showed that the EBH's measured produced no appreciable high-frequency MFs. Data gathered during this work will be used in interpreting results from a component of the California Pregnancy Outcome Study, which evaluates the use of EBHs as a possible risk factor in miscarriage.
Human mRNA polyadenylate binding protein: evolutionary conservation of a nucleic acid binding motif.
Grange, T; de Sa, C M; Oddos, J; Pictet, R
1987-01-01
We have isolated a full length cDNA (cDNA) coding for the human poly(A) binding protein. The cDNA derived 73 kd basic translation product has the same Mr, isoelectric point and peptidic map as the poly(A) binding protein. DNA sequence analysis reveals a 70,244 dalton protein. The N terminal part, highly homologous to the yeast poly(A) binding protein, is sufficient for poly(A) binding activity. This domain consists of a four-fold repeated unit of approximately 80 amino acids present in other nucleic acid binding proteins. In the C terminal part there is, as in the yeast protein, a sequence of approximately 150 amino acids, rich in proline, alanine and glutamine which together account for 48% of the residues. A 2,9 kb mRNA corresponding to this cDNA has been detected in several vertebrate cell types and in Drosophila melanogaster at every developmental stage including oogenesis. Images PMID:2885805
Chemical reactions occurring during direct solar reduction of CO2.
Lyma, J L; Jensen, R J
2001-09-28
At high temperatures carbon dioxide may absorb solar radiation and react to form carbon monoxide and molecular oxygen. The CO, so produced, may be converted by well-established means to a combustible fuel, such as methanol. We intend to make a future demonstration of the solar reduction of CO2 based on these processes. This paper, however, addresses only the problem of preserving, or even enhancing, the initial photolytic CO by quenching the hot gas with colder H2O or CO2. We present model calculations with a reaction mechanism used extensively in other calculations. If a CO2 gas stream is heated and photolyzed by intense solar radiation and then allowed to cool slowly, it will react back to the initial CO2 by a series of elementary chemical reactions. The back reaction to CO2 can be terminated with the rapid addition of CO2, water, or a mixture. Calculations show that a three-fold quench with pure CO2 will stop the reactions and preserve over 90% of the initial photolytic CO. We find that water has one of two effects. It can either increase the CO level, or it can catalyze the recombination of O and CO to CO2. The gas temperature is the determining factor. If the quench gas is not sufficient to keep the temperature below approximately 1100 K, a chain-branching reaction dominates and the reaction to CO2 occurs. If the temperature stays below that level a chain terminating reaction dominates and the CO is increased. The former case occurs below approximately a fourfold quench with a water/CO2 mixture. The later case occurs when the quench is greater than fourfold. We conclude that CO2, H2O, or a mixture may quench the hot gas stream photolyzed by solar radiation and preserve the photolytic CO.
Controlled higher-order transverse mode conversion from a fiber laser by polarization manipulation
NASA Astrophysics Data System (ADS)
Huang, Bin; Yi, Qian; Yang, Lingling; Zhao, Chujun; Wen, Shuangchun
2018-02-01
We report a vectorial fiber laser with controlled transverse mode conversion by intra-cavity polarization manipulation. By combining a q-plate and two quarter-wave plates (QWPs), we can generate a switchable polarization state output represented by the higher-order Poincaré sphere (l = +1, l = -1), and distinguish the fourfold degenerate LP11 mode. The four transverse vector modes can be obtained and switched in a flexible way, and the slope efficiency of the fiber laser can reach up to 39.4%. This compactness, high efficiency, and switchable operation potential will benefit a range of applications, such as materials processing, particle manipulation, etc.
Scanning the skeleton of the 4D F-theory landscape
NASA Astrophysics Data System (ADS)
Taylor, Washington; Wang, Yi-Nan
2018-01-01
Using a one-way Monte Carlo algorithm from several different starting points, we get an approximation to the distribution of toric threefold bases that can be used in four-dimensional F-theory compactification. We separate the threefold bases into "resolvable" ones where the Weierstrass polynomials ( f, g) can vanish to order (4 , 6) or higher on codimension-two loci and the "good" bases where these (4 , 6) loci are not allowed. A simple estimate suggests that the number of distinct resolvable base geometries exceeds 103000, with over 10250 "good" bases, though the actual numbers are likely much larger. We find that the good bases are concentrated at specific "end points" with special isolated values of h 1,1 that are bigger than 1,000. These end point bases give Calabi-Yau fourfolds with specific Hodge numbers mirror to elliptic fibrations over simple threefolds. The non-Higgsable gauge groups on the end point bases are almost entirely made of products of E 8, F 4, G 2 and SU(2). Nonetheless, we find a large class of good bases with a single non-Higgsable SU(3). Moreover, by randomly contracting the end point bases, we find many resolvable bases with h 1,1( B) ˜ 50-200 that cannot be contracted to another smooth threefold base.
Reduction of Phase Ambiguity in an Offset-QPSK Receiver
NASA Technical Reports Server (NTRS)
Berner, Jeff; Kinman, Peter
2004-01-01
Proposed modifications of an offset-quadri-phase-shift keying (offset-QPSK) transmitter and receiver would reduce the amount of signal processing that must be done in the receiver to resolve the QPSK fourfold phase ambiguity. Resolution of the phase ambiguity is necessary in order to synchronize, with the received carrier signal, the signal generated by a local oscillator in a carrier-tracking loop in the receiver. Without resolution of the fourfold phase ambiguity, the loop could lock to any of four possible phase points, only one of which has the proper phase relationship with the carrier. The proposal applies, more specifically, to an offset-QPSK receiver that contains a carrier-tracking loop like that shown in Figure 1. This carrier-tracking loop does not resolve or reduce the phase ambiguity. A carrier-tracking loop of a different design optimized for the reception of offset QPSK could reduce the phase ambiguity from fourfold to twofold, but would be more complex. Alternatively, one could resolve the fourfold phase ambiguity by use of differential coding in the transmitter, at a cost of reduced power efficiency. The proposed modifications would make it possible to reduce the fourfold phase ambiguity to twofold, with no loss in power efficiency and only relatively simple additional signal-processing steps in the transmitter and receiver. The twofold phase ambiguity would then be resolved by use of a unique synchronization word, as is commonly done in binary phase-shift keying (BPSK). Although the mathematical and signal-processing principles underlying the modifications are too complex to explain in detail here, the modifications themselves would be relatively simple and are best described with the help of simple block diagrams (see Figure 2). In the transmitter, one would add a unit that would periodically invert bits going into the QPSK modulator; in the receiver, one would add a unit that would effect different but corresponding inversions of bits coming out of the QPSK demodulator. The net effect of all the inversions would be that depending on which lock point the carrier-tracking loop had selected, all the output bits would be either inverted or non-inverted together; hence, the ambiguity would be reduced from fourfold to twofold, as desired.
Lee, Seung-Hwan; Han, Kyungdo; Yang, Hae Kyung; Kim, Mee Kyoung; Yoon, Kun-Ho; Kwon, Hyuk-Sang; Park, Yong-Moon
2015-02-01
To determine whether the TyG index, a product of the levels of triglycerides and glucose, may be a valuable marker for identifying metabolically obese but normal weight (MONW) or metabolically healthy but obese (MHO) individuals. A total of 17 029 nondiabetic subjects (7185 men and 9844 women) were selected from the Korea National Health and Nutrition Examination Survey conducted in 2008-2010. Individuals with a normal body mass index (BMI) (≥18·5 and <23 kg/m(2) ) and the highest quartile of the homoeostasis model assessment of insulin resistance (HOMA-IR) were classified as MONW. Individuals with obesity (BMI ≥25 kg/m(2) ) and the lowest quartile of HOMA-IR were classified as MHO. The TyG index was calculated as ln[fasting triglycerides (mg/dl) × fasting glucose (mg/dl)/2]. The levels of the TyG index paralleled with various metabolic risk parameters. The index was significantly higher in the MONW group and lower in the MHO group when compared with the non-MONW group and the non-MHO group, respectively. The odds ratios (ORs) of being categorized into the MONW group were approximately fourfold higher in the highest vs lowest quartiles of the TyG index (3·999: 95% CI, 2·508-6·376 in men; 4·737: 95% CI, 3·418-6·565 in women) among normal weight subjects. Conversely, there was a stepwise decrease in the OR of being categorized into the MHO group across the TyG index quartiles among obese subjects. These data highlight the value of the TyG index in discriminating those subjects with higher risks of metabolic diseases. © 2014 John Wiley & Sons Ltd.
Magnetic quantum tunneling: key insights from multi-dimensional high-field EPR.
Lawrence, J; Yang, E-C; Hendrickson, D N; Hill, S
2009-08-21
Multi-dimensional high-field/frequency electron paramagnetic resonance (HFEPR) spectroscopy is performed on single-crystals of the high-symmetry spin S = 4 tetranuclear single-molecule magnet (SMM) [Ni(hmp)(dmb)Cl](4), where hmp(-) is the anion of 2-hydroxymethylpyridine and dmb is 3,3-dimethyl-1-butanol. Measurements performed as a function of the applied magnetic field strength and its orientation within the hard-plane reveal the four-fold behavior associated with the fourth order transverse zero-field splitting (ZFS) interaction, (1/2)B(S + S), within the framework of a rigid spin approximation (with S = 4). This ZFS interaction mixes the m(s) = +/-4 ground states in second order of perturbation, generating a sizeable (12 MHz) tunnel splitting, which explains the fast magnetic quantum tunneling in this SMM. Meanwhile, multi-frequency measurements performed with the field parallel to the easy-axis reveal HFEPR transitions associated with excited spin multiplets (S < 4). Analysis of the temperature dependence of the intensities of these transitions enables determination of the isotropic Heisenberg exchange constant, J = -6.0 cm(-1), which couples the four spin s = 1 Ni(II) ions within the cluster, as well as a characterization of the ZFS within excited states. The combined experimental studies support recent work indicating that the fourth order anisotropy associated with the S = 4 state originates from second order ZFS interactions associated with the individual Ni(II) centers, but only as a result of higher-order processes that occur via S-mixing between the ground state and higher-lying (S < 4) spin multiplets. We argue that this S-mixing plays an important role in the low-temperature quantum dynamics associated with many other well known SMMs.
Type 2 diabetes is associated with low muscle mass in older adults.
Kim, Kyung-Soo; Park, Kyung-Sun; Kim, Moon-Jong; Kim, Soo-Kyung; Cho, Yong-Wook; Park, Seok Won
2014-02-01
Our aim was to clarify the association between type 2 diabetes and the risk of low muscle mass in older adults. In the present study, 414 adults aged 65 years or older (144 patients with type 2 diabetes and 270 control participants) were included. Body composition was measured by dual-energy X-ray absorptiometry. Low muscle mass was defined as the appendicular skeletal muscle mass/height(2) (ASM/Ht(2)) or appendicular skeletal muscle mass/weight (ASM/Wt) of <2 SD below the sex-specific normal mean of the young reference group, or
NASA Astrophysics Data System (ADS)
Kim, Young J.; Kim, Kyung W.; Kim, Shin D.; Lee, Bo K.; Han, Jin S.
In order to investigate the causes of visibility degradation in the metropolitan area of Seoul, extensive chemical and optical monitoring of aerosol was conducted at two urban sites; Junnong, Seoul and Yonghyun, Incheon during several seasonal intensive monitoring periods between August 2002 and August 2004. Light extinction, scattering, and absorption coefficients were measured simultaneously with a transmissometer, a nephelometer, and an aethalometer, respectively. Continuous aerosol chemical measurement was also made with Sunset elemental carbon/organic carbon (EC/OC) analyzers and on-line ion monitors. The mean light extinction budget for five major aerosol components; ammonium sulfate, ammonium nitrate, fine carbonaceous particles (EC and OC), fine soil, and coarse particle was estimated based on the measurement results. Investigation of the haze level revealed that PM 2.5 mass concentrations at Junnong and Yonghyun measured under the Worst20% condition were approximately twice those of the Best20% condition. The worst visibility condition was well correlated with increases in mass concentrations of sulfate and nitrate, and EC particles. The mass concentration of aerosol components for the Worst20% was measured to be approximately two- to four-fold higher than those for the Best20%. Degree of visibility degradation was also analyzed based on the air mass pathway information obtained using the HYSPLIT model. Average light extinction coefficients under continental air flow condition at the Junnong and Yonghyun sites were the highest values of 704±414 and 773±546 Mm -1, respectively due to increased loading of fine particles. Visibility was greatly improved at both sites when atmosphere was impacted by air mass originated from Pacific Ocean.
1990-01-01
The nature of the intracellular pH-regulatory mechanism after imposition of an alkaline load was investigated in isolated human peripheral blood neutrophils. Cells were alkalinized by removal of a DMO prepulse. The major part of the recovery could be ascribed to a Cl- /HCO3- counter-transport system: specifically, a one-for-one exchange of external Cl- for internal HCO3-. This exchange mechanism was sensitive to competitive inhibition by the cinnamate derivative UK-5099 (Ki approximately 1 microM). The half-saturation constants for binding of HCO3- and Cl- to the external translocation site of the carrier were approximately 2.5 and approximately 5.0 mM. In addition, other halides and lyotropic anions could substitute for external Cl-. These ions interacted with the exchanger in a sequence of decreasing affinities: HCO3- greater than Cl approximately NO3- approximately Br greater than I- approximately SCN- greater than PAH-. Glucuronate and SO4(2-) lacked any appreciable affinity. This rank order is reminiscent of the selectivity sequence for the principal anion exchanger in resting cells. Cl- and HCO3- displayed competition kinetics at both the internal and external binding sites of the carrier. Finally, evidence compatible with the existence of an approximately fourfold asymmetry (Michaelis constants inside greater than outside) between inward- and outward-facing states is presented. These results imply that a Cl-/HCO3- exchange mechanism, which displays several properties in common with the classical inorganic anion exchanger of erythrocytes, is primarily responsible for restoring the pHi of human neutrophils to its normal resting value after alkalinization. PMID:2280252
Electronic Structure of Two-Dimensional Hydrocarbon Networks of sp2 and sp3 C Atoms
NASA Astrophysics Data System (ADS)
Fujii, Yasumaru; Maruyama, Mina; Wakabayashi, Katsunori; Nakada, Kyoko; Okada, Susumu
2018-03-01
Based on density functional theory with the generalized gradient approximation, we have investigated the geometric and electronic structures of two-dimensional hexagonal covalent networks consisting of oligoacenes and fourfold coordinated hydrocarbon atoms, which are alternately arranged in a hexagonal manner. All networks were semiconductors with a finite energy gap at the Γ point, which monotonically decreased with the increase of the oligoacene length. As a result of a Kagome network of oligoacene connected through sp3 C atoms, the networks possess peculiar electron states in their valence and conduction bands, which consist of a flat dispersion band and a Dirac cone. The total energy of the networks depends on the oligoacene length and has a minimum for the network comprising naphthalene.
Polymerization on the rocks: negatively-charged alpha-amino acids
NASA Technical Reports Server (NTRS)
Hill, A. R. Jr; Bohler, C.; Orgel, L. E.; Bada, J. L. (Principal Investigator)
1998-01-01
Oligomers of the negatively-charged amino acids, glutamic acid, aspartic acid, and O-phospho-L-serine are adsorbed by hydroxylapatite and illite with affinities that increase with oligomer length. In the case of oligo-glutamic acids adsorbed on hydroxylapatite, addition of an extra residue results in an approximately four-fold increase in the strength of adsorption. Oligomers much longer than the 7-mer are retained tenaciously by the mineral. Repeated incubation of short oligo-glutamic acids adsorbed on hydroxylapatite or illite with activated monomer leads to the accumulation of oligomers at least 45 units long. The corresponding reactions of aspartic acid and O-phospho-L-serine on hydroxylapatite are less effective in generating long oligomers, while illite fails to accumulate substantial amounts of long oligomers of aspartic acid or of O-phospho-L-serine.
Defect reduction of SiNx embedded m-plane GaN grown by hydride vapor phase epitaxy
NASA Astrophysics Data System (ADS)
Woo, Seohwi; Kim, Minho; So, Byeongchan; Yoo, Geunho; Jang, Jongjin; Lee, Kyuseung; Nam, Okhyun
2014-12-01
Nonpolar (1 0 -1 0) m-plane GaN has been grown on m-plane sapphire substrates by hydride vapor phase epitaxy (HVPE). We studied the defect reduction of m-GaN with embedded SiNx interlayers deposited by ex-situ metal organic chemical vapor deposition (MOCVD). The full-width at half-maximum values of the X-ray rocking curves for m-GaN with embedded SiNx along [1 1 -2 0]GaN and [0 0 0 1]GaN were reduced to 528 and 1427 arcs, respectively, as compared with the respective values of 947 and 3170 arcs, of m-GaN without SiNx. Cross-section transmission electron microscopy revealed that the basal stacking fault density was decreased by approximately one order to 5×104 cm-1 due to the defect blocking of the embedded SiNx. As a result, the near band edge emission intensities of the room-temperature and low-temperature photoluminescence showed approximately two-fold and four-fold improvement, respectively.
A prospective study of phrenic nerve damage after cardiac surgery in children.
Ross Russell, Robert I; Helms, Peter J; Elliott, Martin J
2008-04-01
To gather detailed data on the incidence of phrenic nerve damage (PND) following cardiac surgery in children, the risk factors for its development, its effect on morbidity and its prognosis. Prospective electrophysiological measurement of phrenic nerve latency in 310 children before and after cardiac surgery. Tertiary paediatric cardiac surgical centre. Our findings were fourfold. Firstly, the incidence of PND in our group of patients was 20%, significantly higher than estimates using indirect methods of assessment. Secondly, PND increased the duration of ventilation by a median of 76 h (20 vs. 96 h; p<0.001), and late post-operative deaths (before hospital discharge) occurred in 12.9% of patients compared to 2.4% among patients with a normal post-operative phrenic latency. Thirdly, the risk factors that were independently predictive of the development of PND were the site of the surgery and the patient's age. Patients who required surgery at both the lung hilum and the pericardium were more likely to develop PND than patients with only one of those sites, or when neither was involved, and children less than 18 months old were more likely to develop PND than older children. Lastly, the natural history of PND following surgery appears to be good. In our follow-up to 3 months, approximately one third recovered within 1 month and a further third (overall) recovered by 3 months. We conclude that the incidence of PND is much higher than currently recognised, and has a very significant effect on post-operative morbidity and mortality. Most children who survive the post-operative period will recover nerve function within 3 months.
Increased cell-free DNA concentrations in patients with obstructive sleep apnea.
Shin, Chol; Kim, Jin K; Kim, Je H; Jung, Ki H; Cho, Kyung J; Lee, Chang K; Lee, Seung G
2008-12-01
Blood concentrations of cell-free DNA, which is considered to be released during apoptosis, are elevated under some pathological conditions such as cardiovascular disease and cancer. The association between obstructive sleep apnea (OSA) and cell-free DNA concentrations has not been reported so far. The purpose of the present study was to examine the association between OSA and plasma DNA concentrations. A case-control study was conducted using a total of 164 men aged 39-67 years, who were free of coronary heart disease and cancer. Laboratory-based overnight polysomnography was performed for all participants. On the basis of polysomnography, patients with an apnea-hypopnea index (AHI) = 5-30 events/h were defined as having mild-moderate OSA (n = 33) and those with >30 events/h were defined as having severe OSA (n = 49). All 82 controls had AHI < 5 events/h. Plasma DNA concentrations from all participants were analyzed for the beta-globin gene using fluorescence-based real-time polymerase chain reaction. Patients with severe OSA had significantly higher plasma DNA concentrations than persons with mild-moderate OSA and those without OSA (P < 0.05). AHI was significantly associated with body mass index (P < 0.001), hypertension (P < 0.001), and plasma DNA concentration (P < 0.05). After taking into account hypertension and other potential risk factors, persons with high plasma DNA concentrations (>8 microg/L) had approximately fourfold higher odds of OSA than those with low DNA levels. Further data are warranted to confirm the association for men and to evaluate the association for women.
Dieter, M.P.
1975-01-01
Wild-trapped starlings (Sturnus vulgaris) were fed concentrations of Morsodren (2, 4, and 8 ppm), DDE or Aroclor 1254 (5, 25, and 100 ppm), or malathion (8, 35, and 160 ppm) that were found to be sublethal in pen-reared Coturnix quail fed these amounts for 12 weeks. Plasma enzymes had to be measured earlier than planned in starlings fed Morsodren (at three weeks) or the organochlorine compounds (at seven weeks) because of unexpected, subsequent mortality. Variations in enzyme response were greater in wild than in pen-reared birds, but not enough to mask the toxicant-induced changes in enzyme activity. Cholinesterase activities decreased in birds fed Morsodren or malathion, and increased in those fed the organochlorine compounds. Lactate dehydrogenase activities increased two-fold in starlings fed Morsodren and two- to four-fold in those fed the organochlorine compounds, but only 50% in those fed malathion. Further examination of enzyme profiles showed that creatine kinase and aspartate aminotransferase activities increased two-to four-fold in birds fed Morsodren or the organochlorine compounds but not at all in those fed malathion. Thus the classes of environmental contaminants fed to starlings could be easily distinguished by these enzymatic parameters. Evaluation of enzymatic profiles appears to be a potentially valuable technique to monitor the presence of toxicants in wild populations, especially if used to complement standard chemical residue analyses. Here the residue analyses showed, after three weeks feeding, that mercury in the carcasses reflected the concentrations fed daily, whereas accumulation in the livers was two- to four-fold greater. After seven weeks feeding, liver residues of either organochlorine compound were about three-fold higher than the concentrations fed daily. However, four times as much DDE as Aroclor 1254 had accumulated in the carcasses.
Treatment of allergic rhinitis and urticaria: a review of the newest antihistamine drug bilastine.
Wang, Xue Yan; Lim-Jurado, Margaret; Prepageran, Narayanan; Tantilipikorn, Pongsakorn; Wang, De Yun
2016-01-01
Allergic rhinitis and urticaria are common allergic diseases that may have a major negative impact on patients' quality of life. Bilastine, a novel new-generation antihistamine that is highly selective for the H1 histamine receptor, has a rapid onset and prolonged duration of action. This agent does not interact with the cytochrome P450 system and does not undergo significant metabolism in humans, suggesting that it has very low potential for drug-drug interactions, and does not require dose adjustment in renal impairment. As bilastine is not metabolized and is excreted largely unchanged, hepatic impairment is not expected to increase systemic exposure above the drug's safety margin. Bilastine has demonstrated similar efficacy to cetirizine and desloratadine in patients with seasonal allergic rhinitis and, in a Vienna Chamber study, a potentially longer duration of action than fexofenadine in patients with asymptomatic seasonal allergic rhinitis. It has also shown significant efficacy (similar to that of cetirizine) and safety in the long-term treatment of perennial allergic rhinitis. Bilastine showed similar efficacy to levocetirizine in patients with chronic spontaneous urticaria and can be safely used at doses of up to fourfold higher than standard dosage (80 mg once daily). The fourfold higher than standard dose is specified as an acceptable second-line treatment option for urticaria in international guidelines. Bilastine is generally well tolerated, both at standard and at supratherapeutic doses, appears to have less sedative potential than other second-generation antihistamines, and has no cardiotoxicity. Based on its pharmacokinetic properties, efficacy, and tolerability profile, bilastine will be valuable in the management of allergic rhinitis and urticaria.
Thorburn, A W; Gumbiner, B; Bulacan, F; Brechtel, G; Henry, R R
1991-01-01
To define the mechanisms of impaired muscle glycogen synthase and reduced glycogen formation in non-insulin dependent diabetes mellitus (NIDDM), glycogen synthase activity was kinetically analyzed during the basal state and three glucose clamp studies (insulin approximately equal to 300, 700, and 33,400 pmol/liter) in eight matched nonobese NIDDM and eight control subjects. Muscle glycogen content was measured in the basal state and following clamps at insulin levels of 33,400 pmol/liter. NIDDM subjects had glucose uptake matched to controls in each clamp by raising serum glucose to 15-20 mmol/liter. The insulin concentration required to half-maximally activate glycogen synthase (ED50) was approximately fourfold greater for NIDDM than control subjects (1,004 +/- 264 vs. 257 +/- 110 pmol/liter, P less than 0.02) but the maximal insulin effect was similar. Total glycogen synthase activity was reduced approximately 38% and glycogen content was approximately 30% lower in NIDDM. A positive correlation was present between glycogen content and glycogen synthase activity (r = 0.51, P less than 0.01). In summary, defects in muscle glycogen synthase activity and reduced glycogen content are present in NIDDM. NIDDM subjects also have less total glycogen synthase activity consistent with reduced functional mass of the enzyme. These findings and the correlation between glycogen synthase activity and glycogen content support the theory that multiple defects in glycogen synthase activity combine to cause reduced glycogen formation in NIDDM. PMID:1899428
Ubiquinone Function in Neurospora crassa
Drabikowska, Alicja K.; Kruszewska, Anna
1972-01-01
Mitochondria of cytoplasmic respiratory mutants [mi-1] (poky) and [mi-4] contain about a fourfold molar excess of ubiquinone as compared to the wild-type strain of Neurospora crassa. In the wild type and [mi-1] cultures the concentration of ubiquinone remains constant during the exponential and stationary phase of growth. In [mi-4] cultures it markedly decreases in the stationary phase. The reduction of ubiquinone by substrates is approximately the same in the three strains tested and amounts 60 to 70% of total ubiquinone present in mitochondria, independent of its absolute amount. The reduction of ubiquinone on addition of substrates is accompanied by the similar reduction of cytochrome c. These indicate that mitochondrial ubiquinone and cytochrome c are involved in processes of oxidation in Neurospora and that ubiquinone belongs mainly if not entirely to the cytochrome system of electron transport in these strains. PMID:4344917
Antecedents and outcomes of a fourfold taxonomy of work-family balance in Chinese employed parents.
Lu, Jia-Fang; Siu, Oi-Ling; Spector, Paul E; Shi, Kan
2009-04-01
The study provided validity evidence for a fourfold taxonomy of work-family balance that comprises direction of influence (work to family vs. family to work) and types of effect (work-family conflict vs. work-family facilitation). Data were collected from 189 employed parents in China. The results obtained from a confirmatory factor analysis supported the factorial validity of the fourfold taxonomy of work-family balance with a Chinese sample. Child care responsibilities, working hours, monthly salary, and organizational family-friendly policy were positively related to the conflict component of work-family balance; whereas new parental experience, spouse support, family-friendly supervisors and coworkers had significant positive effects on the facilitation component of work-family balance. In comparison with the inconsistent effects of work-family conflict, work to family facilitation had consistent positive effects on work and life attitudes. The implications of findings in relation to China and other countries are discussed in the paper.
Mallpress, Dave E W; Fawcett, Tim W; Houston, Alasdair I; McNamara, John M
2015-04-01
A striking feature of human decision making is the fourfold pattern of risk attitudes, involving risk-averse behavior in situations of unlikely losses and likely gains, but risk-seeking behavior in response to likely losses and unlikely gains. Current theories to explain this pattern assume particular psychological processes to reproduce empirical observations, but do not address whether it is adaptive for the decision maker to respond to risk in this way. Here, drawing on insights from behavioral ecology, we build an evolutionary model of risk-sensitive behavior, to investigate whether particular types of environmental conditions could favor a fourfold pattern of risk attitudes. We consider an individual foraging in a changing environment, where energy is needed to prevent starvation and build up reserves for reproduction. The outcome, in terms of reproductive value (a rigorous measure of evolutionary success), of a one-off choice between a risky and a safe gain, or between a risky and a safe loss, determines the risk-sensitive behavior we should expect to see in this environment. Our results show that the fourfold pattern of risk attitudes may be adaptive in an environment in which conditions vary stochastically but are autocorrelated in time. In such an environment the current options provide information about the likely environmental conditions in the future, which affect the optimal pattern of risk sensitivity. Our model predicts that risk preferences should be both path dependent and affected by the decision maker's current state. (c) 2015 APA, all rights reserved).
Runguphan, Weerawat; Keasling, Jay D
2014-01-01
As the serious effects of global climate change become apparent and access to fossil fuels becomes more limited, metabolic engineers and synthetic biologists are looking towards greener sources for transportation fuels. In recent years, microbial production of high-energy fuels by economically efficient bioprocesses has emerged as an attractive alternative to the traditional production of transportation fuels. Here, we engineered the budding yeast Saccharomyces cerevisiae to produce fatty acid-derived biofuels and chemicals from simple sugars. Specifically, we overexpressed all three fatty acid biosynthesis genes, namely acetyl-CoA carboxylase (ACC1), fatty acid synthase 1 (FAS1) and fatty acid synthase 2 (FAS2), in S. cerevisiae. When coupled to triacylglycerol (TAG) production, the engineered strain accumulated lipid to more than 17% of its dry cell weight, a four-fold improvement over the control strain. Understanding that TAG cannot be used directly as fuels, we also engineered S. cerevisiae to produce drop-in fuels and chemicals. Altering the terminal "converting enzyme" in the engineered strain led to the production of free fatty acids at a titer of approximately 400 mg/L, fatty alcohols at approximately 100mg/L and fatty acid ethyl esters (biodiesel) at approximately 5 mg/L directly from simple sugars. We envision that our approach will provide a scalable, controllable and economic route to this important class of chemicals. Copyright © 2013 International Metabolic Engineering Society. All rights reserved.
The El Paso smelter 20 years later: residual impact on Mexican children.
Díaz-Barriga, F; Batres, L; Calderón, J; Lugo, A; Galvao, L; Lara, I; Rizo, P; Arroyave, M E; McConnell, R
1997-01-01
Although there has been considerable concern regarding cross-border industrial contamination between Mexico and the United States, there are remarkably few data. One notable case study is the smelter in El Paso, Texas. In 1974 blood lead levels higher than 40 micrograms/dl were detected in 52% of children studied near the smelter, in the adjacent Mexican community of Anapra in Ciudad Juarez, Chihuahua. Lead smelting at this plant was halted in 1985, and as a result, lead levels in air decreased sharply; consequently, children's exposure to lead and other metals should have diminished accordingly. In order to assess the effect of removal of lead emissions from the area, three geographical locations in Anapra, varying in distance from the smelter source, were evaluated for lead, arsenic, and cadmium levels in soil and for lead in blood of children. It was found that lead levels in soil were inversely correlated with distance from the smelter. Arsenic and cadmium levels in soil were constant among the three sectors. However, at residential sites closer to the smelter, a higher percentage of children was found with blood lead levels exceeding the Centers for Disease Control's action level of 10.0 micrograms/dl. In the sector closest to the border 43% of children had blood lead levels greater than 10.0 micrograms/dl. Although blood lead levels in children living in Anapra have dropped approximately fourfold in 20 years, our results indicate a moderate continued risk of lead exposure. This study demonstrates the persistent impact that may result from cross-border contamination and raises provocative questions regarding appropriate action and the responsibility for financing such action.
Schendel, Diana; Bhasin, Tanya Karapurkar
2008-06-01
The objectives of this study were to compare the birth weight and gestational age distributions and prevalence rates of autism with those of other developmental disabilities and to estimate the birth weight-and gestational age-specific risks for autism. For the first objective, a retrospective cohort of children born in Atlanta, Georgia, in 1981-1993 who survived to 3 years of age was identified through vital records. Children in the cohort who had developmental disabilities (autism, mental retardation, cerebral palsy, hearing loss, or vision impairment) and were still residing in metropolitan Atlanta at 3 to 10 years of age were identified through the Metropolitan Atlanta Developmental Disabilities Surveillance Program. A nested case-control sample from the cohort was used for the second objective; all cohort children identified with autism were case participants, and control participants were cohort children who were not identified as having developmental disabilities or receiving special education services. The prevalence of autism in low birth weight or preterm children was markedly lower than those of other developmental disabilities. In multivariate analyses, birth weight of <2500 g and preterm birth at <33 weeks' gestation were associated with an approximately twofold increased risk for autism, although the magnitude of risk from these factors varied according to gender (higher in girls) and autism subgroup (higher for autism accompanied by other developmental disabilities). For example, a significant fourfold increased risk was observed in low birth weight girls for autism accompanied by mental retardation, whereas there was no significantly increased risk observed in low birth weight boys for autism alone. Gender and autism subgroup differences in birth weight and gestational age, resulting in lower gender ratios with declining birth weight or gestational age across all autism subgroups, might be markers for etiologic heterogeneity in autism.
Nuclear Transport and Accumulation of Smad Proteins Studied by Single-Molecule Microscopy.
Li, Yichen; Luo, Wangxi; Yang, Weidong
2018-05-08
Nuclear translocation of stimulated Smad heterocomplexes is a critical step in the signal transduction of transforming growth factor β (TGF-β) from transmembrane receptors into the nucleus. Specifically, normal nuclear accumulation of Smad2/Smad4 heterocomplexes induced by TGF-β1 is involved in carcinogenesis. However, the relationship between nuclear accumulation and the nucleocytoplasmic transport kinetics of Smad proteins in the presence of TGF-β1 remains obscure. By combining a high-speed single-molecule tracking microscopy and Förster resonance energy transfer technique, we tracked the entire TGF-β1-induced process of Smad2/Smad4 heterocomplex formation, as well as their transport through nuclear pore complexes in live cells, with a high single-molecule localization precision of 2 ms and <20 nm. Our single-molecule Förster resonance energy transfer data have revealed that in TGF-β1-treated cells, Smad2/Smad4 heterocomplexes formed in the cytoplasm, imported through the nuclear pore complexes as entireties, and finally dissociated in the nucleus. Moreover, we found that basal-state Smad2 or Smad4 cannot accumulate in the nucleus without the presence of TGF-β1, mainly because both of them have an approximately twofold higher nuclear export efficiency compared to their nuclear import. Remarkably and reversely, heterocomplexes of Smad2/Smad4 induced by TGF-β1 can rapidly concentrate in the nucleus because of their almost fourfold higher nuclear import rate in comparison with their nuclear export rate. Thus, we believe that the determined TGF-β1-dependent transport configurations and efficiencies for the basal-state Smad or stimulated Smad heterocomplexes elucidate the basic molecular mechanism to understand their nuclear transport and accumulation. Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.
Zhang, Jinglan; Fedick, Anastasia; Wasserman, Stephanie; Zhao, Geping; Edelmann, Lisa; Bottinger, Erwin P; Kornreich, Ruth; Scott, Stuart A
2016-03-01
The incidence of chronic kidney disease (CKD) varies by ancestry, with African Americans (AA) having a threefold to fourfold higher rate than whites. Notably, two APOL1 alleles, termed G1 [c.(1072A>G; 1200T>G)] and G2 (c.1212_1217del6), are strongly associated with higher rates of nondiabetic CKD and an increased risk for hypertensive end-stage renal disease. This has prompted the opportunity to implement APOL1 testing to identify at-risk patients and modify other risk factors to reduce the progression of CKD to end-stage renal disease. We developed an APOL1 genotyping assay using multiplex allele-specific primer extension, and validated using 58 positive and negative controls. Genotyping results were completely concordant with Sanger sequencing, and both triplicate interrun and intrarun genotyping results were completely concordant. Multiethnic APOL1 allele frequencies were also determined by genotyping 7059 AA, Hispanic, and Asian individuals from the New York City metropolitan area. The AA, Hispanic, and Asian APOL1 G1 and G2 allele frequencies were 0.22 and 0.13, 0.037 and 0.025, and 0.013 and 0.004, respectively. Notably, approximately 14% of the AA population carried two risk alleles and are at increased risk for CKD, compared with <1% of the Hispanic and Asian populations. This novel APOL1 genotyping assay is robust and highly accurate, and represents one of the first personalized medicine clinical genetic tests for disease risk prediction. Copyright © 2016 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.
Local structural order and relaxation effects in metal-chalcogenide glasses
DOE Office of Scientific and Technical Information (OSTI.GOV)
Saleh, Z.M.
1990-01-01
Nuclear quadrupole resonance (NQR) and nuclear magnetic resonance (NMR) have been employed to study the local structural order and the relaxation mechanisms in metal-arsenic-chalcogenide glasses for metal concentrations within the glass forming region. The glass forming region in the Cu-As-S and Cu-As-se glassy systems extends approximately to 6 and 25 at. % copper, respectively. In the composition Cu[sub x](As[sub 2/5]Ch[sub 3/5])[sub 1[minus]x], where Ch = S or Se, there is evidence of dramatic changes in the local structure as copper is added to the system. One important change is the formation of As-As bonds which are absent in As[sub 2]Ch[submore » 3]. The [sup 75]As NQR measurements indicate that the density of these bonds increases with copper concentration x. These results are consistent with the predictions of a model proposed recently to explain the local structural order in glassy metal chalcogenides. While NQR data show that arsenic atoms are threefold coordinated, EXAFs measurements have shown that copper is fourfold coordinated within the glass forming ranges in both systems. The NMR measurements confirm this result and quantitatively determine the local environment around the copper nuclei. For the naturally occurring mineral luzonite (Cu[sub 3]AsS[sub 4]) copper is fourfold coordinated. The known structure of this mineral has been used as a guide to understanding the local structure in the glasses. Copper and arsenic nuclear relaxation measurements were used to study the dynamics of these systems. The temperature and frequency dependence of the spin-lattice and spin-spin relaxation times have been carefully measured to determine the relaxation mechanisms.« less
NASA Technical Reports Server (NTRS)
O'Sullivan, Cathal E.; Peng, RongSheng; Cole, Kelly Stefano; Montelaro, Ronald C.; Sturgeon, Timothy; Jenson, Hal B.; Ling, Paul D.; Butel, J. S. (Principal Investigator)
2002-01-01
Epstein-Barr virus (EBV) associated non-Hodgkin lymphoma is recognized as a complication of human immunodeficiency virus (HIV) infection. Little is known regarding the influence of highly active antiretroviral therapy (HAART) on the biology of EBV in this population. To characterize the EBV- and HIV-specific serological responses together with EBV DNA levels in a cohort of HIV-infected adults treated with HAART, a study was conducted to compare EBV and HIV serologies and EBV DNA copy number (DNAemia) over a 12-month period after the commencement of HAART. All patients were seropositive for EBV at baseline. Approximately 50% of patients had detectable EBV DNA at baseline, and 27/30 had detectable EBV DNA at some point over the follow-up period of 1 year. Changes in EBV DNA copy number over time for any individual were unpredictable. Significant increases in the levels of Epstein-Barr nuclear antigen (EBNA) and Epstein-Barr early antigen (EA) antibodies were demonstrated in the 17 patients who had a good response to HAART. Of 29 patients with paired samples tested, four-fold or greater increases in titers were detected for EA in 12/29 (41%), for EBNA in 7/29 (24%), for VCA-IgG in 4/29 (14%); four-fold decreases in titers were detected in 2/29 (7%) for EA and 12/29 (41%) for EBNA. A significant decline in the titer of anti-HIV antibodies was also demonstrated. It was concluded that patients with advanced HIV infection who respond to HAART have an increase in their EBV specific antibodies and a decrease in their HIV-specific antibodies. For the cohort overall, there was a transient increase in EBV DNA levels that had declined by 12 months. Copyright 2002 Wiley-Liss, Inc.
Treatment of allergic rhinitis and urticaria: a review of the newest antihistamine drug bilastine
Wang, Xue Yan; Lim-Jurado, Margaret; Prepageran, Narayanan; Tantilipikorn, Pongsakorn; Wang, De Yun
2016-01-01
Allergic rhinitis and urticaria are common allergic diseases that may have a major negative impact on patients’ quality of life. Bilastine, a novel new-generation antihistamine that is highly selective for the H1 histamine receptor, has a rapid onset and prolonged duration of action. This agent does not interact with the cytochrome P450 system and does not undergo significant metabolism in humans, suggesting that it has very low potential for drug–drug interactions, and does not require dose adjustment in renal impairment. As bilastine is not metabolized and is excreted largely unchanged, hepatic impairment is not expected to increase systemic exposure above the drug’s safety margin. Bilastine has demonstrated similar efficacy to cetirizine and desloratadine in patients with seasonal allergic rhinitis and, in a Vienna Chamber study, a potentially longer duration of action than fexofenadine in patients with asymptomatic seasonal allergic rhinitis. It has also shown significant efficacy (similar to that of cetirizine) and safety in the long-term treatment of perennial allergic rhinitis. Bilastine showed similar efficacy to levocetirizine in patients with chronic spontaneous urticaria and can be safely used at doses of up to fourfold higher than standard dosage (80 mg once daily). The fourfold higher than standard dose is specified as an acceptable second-line treatment option for urticaria in international guidelines. Bilastine is generally well tolerated, both at standard and at supratherapeutic doses, appears to have less sedative potential than other second-generation antihistamines, and has no cardiotoxicity. Based on its pharmacokinetic properties, efficacy, and tolerability profile, bilastine will be valuable in the management of allergic rhinitis and urticaria. PMID:27110120
The Effect of Sea-Surface Sun Glitter on Microwave Radiometer Measurements
NASA Technical Reports Server (NTRS)
Wentz, F. J.
1981-01-01
A relatively simple model for the microwave brightness temperature of sea surface Sun glitter is presented. The model is an accurate closeform approximation for the fourfold Sun glitter integral. The model computations indicate that Sun glitter contamination of on orbit radiometer measurements is appreciable over a large swath area. For winds near 20 m/s, Sun glitter affects the retrieval of environmental parameters for Sun angles as large as 20 to 25 deg. The model predicted biases in retrieved wind speed and sea surface temperature due to neglecting Sun glitter are consistent with those experimentally observed in SEASAT SMMR retrievals. A least squares retrieval algorithm that uses a combined sea and Sun model function shows the potential of retrieving accurate environmental parameters in the presence of Sun glitter so long as the Sun angles and wind speed are above 5 deg and 2 m/s, respectively.
Water-soluble cavitands promote hydrolyses of long-chain diesters
Shi, Qixun; Mower, Matthew P.; Blackmond, Donna G.; Rebek, Julius
2016-01-01
Water-soluble, deep cavitands serve as chaperones of long-chain diesters for their selective hydrolysis in aqueous solution. The cavitands bind the diesters in rapidly exchanging, folded J-shape conformations that bury the hydrocarbon chain and expose each ester group in turn to the aqueous medium. The acid hydrolyses in the presence of the cavitand result in enhanced yields of monoacid monoester products. Product distributions indicate a two- to fourfold relative decrease in the hydrolysis rate constant of the second ester caused by the confined space in the cavitand. The rate constant for the first acid hydrolysis step is enhanced approximately 10-fold in the presence of the cavitand, compared with control reactions of the molecules in bulk solution. Hydrolysis under basic conditions (saponification) with the cavitand gave >90% yields of the corresponding monoesters. Under basic conditions the cavitand complex of the monoanion precipitates from solution and prevents further reaction. PMID:27482089
Hatcher, N. G.; Zhang, X.; Stuart, J. N.; Moroz, L. L.; Sweedler, J. V.; Gillette, R.
2014-01-01
Serotonin (5-HT) is an intrinsic modulator of neural network excitation states in gastropod molluscs. 5-HT and related indole metabolites were measured in single, well-characterized serotonergic neurons of the feeding motor network of the predatory sea-slug Pleurobranchaea californica. Indole amounts were compared between paired hungry and satiated animals. Levels of 5-HT and its metabolite 5-HT-SO4 in the metacerebral giant neurons were observed in amounts approximately four-fold and two-fold, respectively, below unfed partners 24 h after a satiating meal. Intracellular levels of 5-hydroxyindole acetic acid and of free tryptophan did not differ significantly with hunger state. These data demonstrate that neurotransmitter levels and their metabolites can vary in goal-directed neural networks in a manner that follows internal state. PMID:18036151
Kim, Seungill; Park, Minkyu; Yeom, Seon-In; Kim, Yong-Min; Lee, Je Min; Lee, Hyun-Ah; Seo, Eunyoung; Choi, Jaeyoung; Cheong, Kyeongchae; Kim, Ki-Tae; Jung, Kyongyong; Lee, Gir-Won; Oh, Sang-Keun; Bae, Chungyun; Kim, Saet-Byul; Lee, Hye-Young; Kim, Shin-Young; Kim, Myung-Shin; Kang, Byoung-Cheorl; Jo, Yeong Deuk; Yang, Hee-Bum; Jeong, Hee-Jin; Kang, Won-Hee; Kwon, Jin-Kyung; Shin, Chanseok; Lim, Jae Yun; Park, June Hyun; Huh, Jin Hoe; Kim, June-Sik; Kim, Byung-Dong; Cohen, Oded; Paran, Ilan; Suh, Mi Chung; Lee, Saet Buyl; Kim, Yeon-Ki; Shin, Younhee; Noh, Seung-Jae; Park, Junhyung; Seo, Young Sam; Kwon, Suk-Yoon; Kim, Hyun A; Park, Jeong Mee; Kim, Hyun-Jin; Choi, Sang-Bong; Bosland, Paul W; Reeves, Gregory; Jo, Sung-Hwan; Lee, Bong-Woo; Cho, Hyung-Taeg; Choi, Hee-Seung; Lee, Min-Soo; Yu, Yeisoo; Do Choi, Yang; Park, Beom-Seok; van Deynze, Allen; Ashrafi, Hamid; Hill, Theresa; Kim, Woo Taek; Pai, Hyun-Sook; Ahn, Hee Kyung; Yeam, Inhwa; Giovannoni, James J; Rose, Jocelyn K C; Sørensen, Iben; Lee, Sang-Jik; Kim, Ryan W; Choi, Ik-Young; Choi, Beom-Soon; Lim, Jong-Sung; Lee, Yong-Hwan; Choi, Doil
2014-03-01
Hot pepper (Capsicum annuum), one of the oldest domesticated crops in the Americas, is the most widely grown spice crop in the world. We report whole-genome sequencing and assembly of the hot pepper (Mexican landrace of Capsicum annuum cv. CM334) at 186.6× coverage. We also report resequencing of two cultivated peppers and de novo sequencing of the wild species Capsicum chinense. The genome size of the hot pepper was approximately fourfold larger than that of its close relative tomato, and the genome showed an accumulation of Gypsy and Caulimoviridae family elements. Integrative genomic and transcriptomic analyses suggested that change in gene expression and neofunctionalization of capsaicin synthase have shaped capsaicinoid biosynthesis. We found differential molecular patterns of ripening regulators and ethylene synthesis in hot pepper and tomato. The reference genome will serve as a platform for improving the nutritional and medicinal values of Capsicum species.
NASA Technical Reports Server (NTRS)
Draghia-Akli, R.; Fiorotto, M. L.; Hill, L. A.; Malone, P. B.; Deaver, D. R.; Schwartz, R. J.
1999-01-01
Ectopic expression of a new serum protease-resistant porcine growth hormone-releasing hormone, directed by an injectable muscle-specific synthetic promoter plasmid vector (pSP-HV-GHRH), elicits growth in pigs. A single 10 mg intramuscular injection of pSP-HV-GHRH DNA followed by electroporation in three-week-old piglets elevated serum GHRH levels by twofold to fourfold, enhanced growth hormone secretion, and increased serum insulin-like growth factor-I by threefold to sixfold over control pigs. After 65 days the average body weight of the pigs injected with pSP-HV-GHRH was approximately 37% greater than the placebo-injected controls and resulted in a significant reduction in serum urea concentration, indicating a decrease in amino acid catabolism. Evaluation of body composition indicated a uniform increase in mass, with no organomegaly or associated pathology.
Hajiri, T; Yoshida, T; Filianina, M; Jaiswal, S; Borie, B; Asano, H; Zabel, H; Kläui, M
2017-12-05
We report an unusual angular-dependent exchange bias effect in ferromagnet/antiferromagnet bilayers, where both ferromagnet and antiferromagnet are epitaxially grown. Numerical model calculations predict an approximately 45° period for the sign switching of the exchange-bias field, depending on the ratio between magnetocrystalline anisotropy and exchange-coupling constant. The switching of the sign is indicative of a competition between a fourfold magnetocrystalline anisotropy of the ferromagnet and a unidirectional anisotropy field of the exchange coupling. This predicted unusual angular-dependent exchange bias and its magnetization switching process are confirmed by measurements on fully epitaxial Co 3 FeN/MnN bilayers by longitudinal and transverse magneto-optic Kerr effect magnetometry. These results provide a deeper understanding of the exchange coupling phenomena in fully epitaxial bilayers with tailored materials and open up a complex switching energy landscape engineering by anisotropies.
NASA Astrophysics Data System (ADS)
Hajiri, T.; Yoshida, T.; Filianina, M.; Jaiswal, S.; Borie, B.; Asano, H.; Zabel, H.; Kläui, M.
2018-01-01
We report an unusual angular-dependent exchange bias effect in ferromagnet/antiferromagnet bilayers, where both ferromagnet and antiferromagnet are epitaxially grown. Numerical model calculations predict an approximately 45° period for the sign switching of the exchange-bias field, depending on the ratio between magnetocrystalline anisotropy and exchange-coupling constant. The switching of the sign is indicative of a competition between a fourfold magnetocrystalline anisotropy of the ferromagnet and a unidirectional anisotropy field of the exchange coupling. This predicted unusual angular-dependent exchange bias and its magnetization switching process are confirmed by measurements on fully epitaxial Co3FeN/MnN bilayers by longitudinal and transverse magneto-optic Kerr effect magnetometry. These results provide a deeper understanding of the exchange coupling phenomena in fully epitaxial bilayers with tailored materials and open up a complex switching energy landscape engineering by anisotropies.
Academic decision making and prospect theory.
Mowrer, Robert R; Davidson, William B
2011-08-01
Two studies are reported that investigate the applicability of prospect theory to college students' academic decision making. Exp. 1 failed to provide support for the risk-seeking portion of the fourfold pattern predicted by prospect theory but did find the greater weighting of losses over gains. Using a more sensitive dependent measure, in Exp. 2 the results of the first experiment were replicated in terms of the gain-loss effect and also found some support for the fourfold pattern in the interaction between probabilities and gain versus loss. The greatest risk-seeking was found in the high probability loss condition.
Monitoring honeybee venom immunotherapy in children with the basophil activation test.
Žitnik, Simona E K; Vesel, Tina; Avčin, Tadej; Šilar, Mira; Košnik, Mitja; Korošec, Peter
2012-03-01
New in vitro methods are essential for developing better follow-up criteria for venom immunotherapy (VIT). Thirty-one children with a history of honeybee venom-induced systemic anaphylaxis were included in this prospective, single-blinded study. The basophil CD63 activation test (BAT) was assessed before starting VIT, at the end of the build-up phase (day 5), 6 months later, and after 2-4 yr of VIT. Basophil CD63 activation test allowed identification of the culprit insect in 74% of honeybee venom-allergic children. In comparison, IgE reactivity was single positive in only 52% of children. Five days after starting VIT, BAT was highly comparable to before VIT. However, after 6 months and further after 2-4 yr of VIT, a significant and approximately fourfold decrease was demonstrated in CD63 response at sub-maximal 0.1 μg/ml allergen concentration, which mainly represents cellular sensitivity. No such differences were found at a higher 1 μg/ml of allergen concentration. Person-to-person analyses showed that after 2-4 yr of VIT, a marked CD63 decrease was evident in 85% of children. In addition, elevated basophil sensitivity measured before VIT was associated with the appearance of side effects observed during the build-up phase of VIT. Basophil CD63 allergen-specific sensitivity seems to be a promising tool for monitoring protective immune response in honeybee VIT. © 2011 John Wiley & Sons A/S.
Høeg, Tracy B; Moldow, Birgitte; Ellervik, Christina; Klemp, Kristian; Erngaard, Ditte; la Cour, Morten; Buch, Helena
2015-06-01
To determine the prevalence of amblyopia in Denmark before and after the initiation of the Danish national preschool vision screening programme. In a population-based cross-sectional study, 3826 participants of the Danish General Suburban Population Study (GESUS) aged 20 years and older from a Danish rural municipality received a complete general health examination and an ophthalmological interview and examination. This study included a comprehensive ophthalmologic interview, measurement of best corrected visual acuity (BCVA) in each eye, Hirschberg's test for strabismus and two 45-degree retinal fundus photographs of each eye. A complete ophthalmologic examination was performed when indicated. The prevalence of monocular visual impairment (MVI) was 4.26% (95% CI, 3.66-4.95, n = 163). Amblyopia was the most common cause, accounting for 33%. The prevalence of amblyopia was 1.44% (95% CI, 1.01-1.81, n = 55), being higher among non-preschool vision screened persons compared to those who were offered (estimated 95% attendance) preschool vision screening (1.78%, n = 41, 95% CI 1.24-2.33 versus 0.44%, n = 2, 95% CI, 0.12-1.60, p = 0.024). The leading cause of amblyopia was anisometropia (45.5%, 25/55). Amblyopia was the most common cause of MVI. Following the initiation of the Danish national preschool vision screening programme, which has an approximate attendance rate of 95%, the prevalence of amblyopia decreased by fourfold. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.
Ali, Ruhi; Siddiqui, Nadeem
2015-04-01
A series of N-(substituted-2-oxo-4-phenylazetidin-1-yl)-2-((6-substitutedbenzo[d]thiazol-2-yl)amino)acetamide derivatives were synthesized using pharmacophoric features with aromatic hydrophobic aryl ring (A), NH-C=O as hydrogen bonding domain, the nitrogen atom as electron donor (D), and phenyl as distal aryl ring (C). The synthesized molecules were initially screened for anticonvulsant activity using the maximal electroshock seizure (MES) test and the subcutaneous pentylenetetrazole test in albino mice. An acute neurotoxicity study on the synthesized molecules was also carried out using the rotarod test. The results of these tests revealed that two compounds, 5b and 5q, showed promising activity with ED50 values of 15.4 and 18.6 mg/kg and protective indices of 20.7 and 34.9 in the MES test, respectively, which are found to be approximately fourfold higher than those of the standard drugs phenytoin (6.9) and carbamazepine (8.1). These molecules may act as lead of the designed scheme. The pharmacokinetic profiles of all the synthesized compounds were estimated using Molinspiration software. None of the compounds violated Lipinski's "rule of five". The possible structure-activity relationship was discussed. In conclusion, this manuscript shows that the developed model has a highly prognostic power for the further investigation of better benzothiazole derivatives for future discovery and development. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Luther, Stephen L; French, Dustin D; Powell-Cope, Gail; Rubenstein, Laurence Z; Campbell, Robert
2005-10-01
The Veterans Administration (VA) Healthcare system, containing hospital and community-based outpatient clinics, provides the setting for the study. Summary data was obtained from the VA Ambulatory Events Database for fiscal years (FY) 1997-2001 and in-depth data for FY 2001. In FY 2001, the database included approximately 4 million unique patients with 60 million encounters. The purpose of this study was: 1) to quantify injuries and use of services associated with falls among the elderly treated in Veterans Administration (VA) ambulatory care settings using administrative data; 2) to compare fall-related services provided to elderly veterans with those provided to younger veterans. Retrospective analysis of administrative data. This study describes the trends (FY 1997-2001) and patterns of fall-related ambulatory care encounters (FY 2001) in the VA Healthcare System. An approximately four-fold increase in both encounters and patients seen was observed in FY 1997-2001, largely paralleling the growth of VA ambulatory care services. More than two-thirds of the patients treated were found to be over the age of 65. Veterans over the age of 65 were found to be more likely to receive care in the non-urgent setting and had higher numbers of co-morbid conditions than younger veterans. While nearly half of the encounters occurred in the Emergency/Urgent Care setting, fall-related injuries led to services across a wide spectrum of medical and surgical providers/departments. This study represents the first attempt to use the VA Ambulatory Events Database to study fall-related services provided to elderly veterans. In view of the aging population served by the VA and the movement to provide increased services in the outpatient setting, this database provides an important resource for researchers and administrators interested in the prevention and treatment of fall-related injuries.
The cross-sectional shape of the fourfold semitendinosus tendon is oval, not round.
Oshima, Takeshi; Nakase, Junsuke; Numata, Hitoaki; Takata, Yasushi; Tsuchiya, Hiroyuki
2016-12-01
The looped side of the semitendinosus tendon (ST) graft (i.e., the side inserted into the femoral tunnel during anterior cruciate ligament reconstruction) appears to be oval rather than round. The purpose of this study was to investigate the cross section of the fourfold semitendinosus tendon graft and, more specifically, the differences in pressure exerted by a rounded rectangular tunnel versus a round femoral tunnel. Seven STs were harvested from cadaveric knees and a fourfold ST graft was made. Aluminum cubes with round or rectangular tunnels containing four-way pressure-sensitive conductive sensors (vertically and bilaterally) were used. The area of both cubes was the same. The graft was inserted into the tunnels 15 mm from the looped edge. After measuring pressure, the graft was fixed using ultraviolet-curing acrylic resin and was cut at 7.5 mm and 15 mm from the lapel edge. The area, axes for the best fitting ellipse of the cross-section, and ellipticity of the axes were measured. In the round tunnel, the mean contact pressure was 287.0 ± 136.7 gf at the bilateral sensor; there was no contact pressure detected by the vertical sensor. In the rounded rectangular tunnel, the mean contact pressure was 260.9 ± 186.4 gf at the bilateral sensor and 352.9 ± 49.5 gf at the vertical sensor. Ellipticity was 1.25 ± 0.13 at 7.5 mm, and 1.17 ± 0.07 at 15 mm from the lapel edge of the graft. The cross-sectional shape of the fourfold ST graft was not round, but oval. Moreover, the rounded rectangular tunnel was more fitted to the graft than the round tunnel.
Tobing, Landobasa Y. M.; Tjahjana, Liliana; Zhang, Dao Hua; Zhang, Qing; Xiong, Qihua
2013-01-01
Metamaterials provide a good platform for biochemical sensing due to its strong field localization at nanoscale. In this work, we show that electric and magnetic resonant modes in split-ring-resonator (SRR) can be efficiently excited under unpolarized light illumination when the SRRs are arranged in fourfold rotationally symmetric lattice configuration. The fabrication and characterization of deep subwavelength (~λ/15) gold-based SRR structures with resonator size as small as ~ 60 nm are reported with magnetic resonances in Vis-NIR spectrum range. The feasibility for sensing is demonstrated with refractive index sensitivity as high as ~ 636 nm/RIU. PMID:23942416
Assembly of Multi-Phthalocyanines on a Porphyrin Template by Fourfold Rotaxane Formation.
Yamada, Yasuyuki; Kato, Tatsuhisa; Tanaka, Kentaro
2016-08-22
A stacked assembly composed of a porphyrin and two phthalocyanines was prepared through fourfold rotaxane formation. Two phthalocyanine molecules, bearing four 24-crown-8 units, were assembled onto a porphyrin template incorporating four sidechains with two dialkylammonium ions each through pseudorotaxane formation between crown ether units and ammonium ions. The Staudinger phosphite reaction, as the stoppering reaction, resulted in the formation of the stacked heterotrimer composed of a porphyrin and two phthalocyanines connected through a fourfold rotaxane structure. UV/Vis spectroscopic and electrochemical studies of the heterotrimer indicated that there is a significant electronic interaction between the two phthalocyanine units due to the close stacking. The electrochemical oxidation process of the stacked heterotrimer was studied by cyclic voltammetry and spectroelectrochemistry. Electron paramagnetic resonance (EPR) spectroscopy of a dinuclear Cu(II) complex, in which two Cu(II) phthalocyanines were assembled on a metal-free porphyrin template, revealed that two Cu(II) phthalocyanines were located within the stacking distance, which resulted in an antiferromagnetic interaction between the two S=1/2 spins in the ground state of the Cu(2+) ions in the heterotrimer. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Modular amplitudes and flux-superpotentials on elliptic Calabi-Yau fourfolds
NASA Astrophysics Data System (ADS)
Cota, Cesar Fierro; Klemm, Albrecht; Schimannek, Thorsten
2018-01-01
We discuss the period geometry and the topological string amplitudes on elliptically fibered Calabi-Yau fourfolds in toric ambient spaces. In particular, we describe a general procedure to fix integral periods. Using some elementary facts from homological mirror symmetry we then obtain Bridgelands involution and its monodromy action on the integral basis for non-singular elliptically fibered fourfolds. The full monodromy group contains a subgroup that acts as PSL(2,Z) on the Kähler modulus of the fiber and we analyze the consequences of this modularity for the genus zero and genus one amplitudes as well as the associated geometric invariants. We find holomorphic anomaly equations for the amplitudes, reflecting precisely the failure of exact PSL(2,Z) invariance that relates them to quasi-modular forms. Finally we use the integral basis of periods to study the horizontal flux superpotential and the leading order Kähler potential for the moduli fields in F-theory compactifications globally on the complex structure moduli space. For a particular example we verify attractor behaviour at the generic conifold given an aligned choice of flux which we expect to be universal. Furthermore we analyze the superpotential at the orbifold points but find no stable vacua.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hals, Ingrid K., E-mail: ingrid.hals@ntnu.no; Ogata, Hirotaka; Pettersen, Elin
2012-06-29
Highlights: Black-Right-Pointing-Pointer The impact of UCP-2 over expression on mitochondrial function is controversial. Black-Right-Pointing-Pointer We tested mitochondrial functions at defined levels of overexpression. Black-Right-Pointing-Pointer We find minor increases of fatty acid oxidation and uncoupling. Black-Right-Pointing-Pointer Effects were seen only at high level (fourfold) of over expression. Black-Right-Pointing-Pointer Hence it is doubtful whether these effects are of importance in diabetes. -- Abstract: Evidence is conflicting as to the impact of elevated levels of uncoupling protein-2 (UCP-2) on insulin-producing beta cells. Here we investigated effects of a fourfold induction of UCP-2 protein primarily on mitochondrial parameters and tested for replication of positivemore » findings at a lower level of induction. We transfected INS-1 cells to obtain a tet-on inducible cell line. A 48 h exposure to 1 {mu}g/ml of doxycycline (dox) induced UCP-2 fourfold (424 {+-} 113%, mean {+-} SEM) and 0.1 {mu}g/ml twofold (178 {+-} 29%, n = 3). Fourfold induced cells displayed normal viability (MTT, apoptosis), normal cellular insulin contents and, glucose-induced insulin secretion (+27 {+-} 11%) as well as D-[U-{sup 14}C]-glucose oxidation (+5 {+-} 9% at 11 mM glucose). Oxidation of [1-{sup 14}C]-oleate was increased from 4088 to 5797 fmol/{mu}g prot/2 h at 3.3 mM glucose, p < 0.03. Oxidation of L-[{sup 14}C(U)]-glutamine was unaffected. Induction of UCP-2 did not significantly affect measures of mitochondrial membrane potential (Rhodamine 123) or mitochondrial mass (Mitotracker Green) and did not affect ATP levels. Oligomycin-inhibited oxygen consumption (a measure of mitochondrial uncoupling) was marginally increased, the effect being significant in comparison with dox-only treated cells, p < 0.05. Oxygen radicals, assessed by dichlorofluorescin diacetate, were decreased by 30%, p < 0.025. Testing for the lower level of UCP-2 induction did not reproduce any of the positive findings. A fourfold induction of UCP-2 was required to exert minor metabolic effects. These findings question an impact of moderately elevated UCP-2 levels in beta cells as seen in diabetes.« less
Structural transitions in vortex systems with anisotropic interactions
Olszewski, Maciej W.; Eskildsen, M. R.; Reichhardt, Charles; ...
2017-12-29
We introduce a model of vortices in type-II superconductors with a four-fold anisotropy in the vortex–vortex interaction potential. Using numerical simulations we show that the vortex lattice undergoes structural transitions as the anisotropy is increased, with a triangular lattice at low anisotropy, a rhombic intermediate state, and a square lattice for high anisotropy. In some cases we observe a multi-q state consisting of an Archimedean tiling that combines square and triangular local ordering. At very high anisotropy, domains of vortex chain states appear. We discuss how this model can be generalized to higher order anisotropy as well as its applicabilitymore » to other particle-based systems with anisotropic particle–particle interactions.« less
Singh, Ameeta E; Levett, Paul N; Fonseca, Kevin; Jayaraman, Gayatri C; Lee, Bonita E
2015-01-01
Despite universal access to screening for syphilis in all pregnant women in Canada, cases of congenital syphilis have been reported in recent years in areas experiencing a resurgence of infectious syphilis in heterosexual partnerships. Antenatal screening in the first trimester continues to be important and should be repeated at 28 to 32 weeks and again at delivery in women at high risk of acquiring syphilis. The diagnosis of congenital syphilis is complex and is based on a combination of maternal history and clinical and laboratory criteria in both mother and infant. Serologic tests for syphilis remain important in the diagnosis of congenital syphilis and are complicated by the passive transfer of maternal antibodies which can affect the interpretation of reactive serologic tests in the infant. All infants born to mothers with reactive syphilis tests should have nontreponemal tests (NTT) and treponemal tests (TT) performed in parallel with the mother's tests. A fourfold or higher titre in the NTT in the infant at delivery is strongly suggestive of congenital infection but the absence of a fourfold or greater NTT titre does not exclude congenital infection. IgM tests for syphilis are not currently available in Canada and are not recommended due to poor performance. Other evaluation in the newborn infant may include long bone radiographs and cerebrospinal fluid tests but all suspect cases should be managed in conjunction with sexually transmitted infection and/or pediatric experts.
Singh, Ameeta E; Levett, Paul N; Fonseca, Kevin; Jayaraman, Gayatri C; Lee, Bonita E
2015-01-01
Despite universal access to screening for syphilis in all pregnant women in Canada, cases of congenital syphilis have been reported in recent years in areas experiencing a resurgence of infectious syphilis in heterosexual partnerships. Antenatal screening in the first trimester continues to be important and should be repeated at 28 to 32 weeks and again at delivery in women at high risk of acquiring syphilis. The diagnosis of congenital syphilis is complex and is based on a combination of maternal history and clinical and laboratory criteria in both mother and infant. Serologic tests for syphilis remain important in the diagnosis of congenital syphilis and are complicated by the passive transfer of maternal antibodies which can affect the interpretation of reactive serologic tests in the infant. All infants born to mothers with reactive syphilis tests should have nontreponemal tests (NTT) and treponemal tests (TT) performed in parallel with the mother’s tests. A fourfold or higher titre in the NTT in the infant at delivery is strongly suggestive of congenital infection but the absence of a fourfold or greater NTT titre does not exclude congenital infection. IgM tests for syphilis are not currently available in Canada and are not recommended due to poor performance. Other evaluation in the newborn infant may include long bone radiographs and cerebrospinal fluid tests but all suspect cases should be managed in conjunction with sexually transmitted infection and/or pediatric experts. PMID:25798162
Life extension of self-healing polymers with rapidly growing fatigue cracks.
Jones, A S; Rule, J D; Moore, J S; Sottos, N R; White, S R
2007-04-22
Self-healing polymers, based on microencapsulated dicyclopentadiene and Grubbs' catalyst embedded in the polymer matrix, are capable of responding to propagating fatigue cracks by autonomic processes that lead to higher endurance limits and life extension, or even the complete arrest of the crack growth. The amount of fatigue-life extension depends on the relative magnitude of the mechanical kinetics of crack propagation and the chemical kinetics of healing. As the healing kinetics are accelerated, greater fatigue life extension is achieved. The use of wax-protected, recrystallized Grubbs' catalyst leads to a fourfold increase in the rate of polymerization of bulk dicyclopentadiene and extends the fatigue life of a polymer specimen over 30 times longer than a comparable non-healing specimen. The fatigue life of polymers under extremely fast fatigue crack growth can be extended through the incorporation of periodic rest periods, effectively training the self-healing polymeric material to achieve higher endurance limits.
Fourfold symmetric anisotropic magnetoresistance in half-metallic Co2MnSi Heusler alloy thin films
NASA Astrophysics Data System (ADS)
Oogane, Mikihiko; McFadden, Anthony P.; Kota, Yohei; Brown-Heft, Tobias L.; Tsunoda, Masakiyo; Ando, Yasuo; Palmstrøm, Chris J.
2018-06-01
In this study, we systematically investigated the anisotropic magnetoresistance (AMR) effect in half-metallic Co2MnSi Heusler alloy films epitaxially grown by molecular beam epitaxy. The fourfold symmetric AMR was observed in the temperature range of 25–275 K. In addition, the films exhibited a marked change in twofold symmetric AMR below 100 K. This specific temperature dependence of the AMR effect in Co2MnSi films can be caused by the tetragonal crystal field because of the distortion of the lattice at low temperatures. The influence of tetragonal distortion on both the AMR effect and half-metallicity is also discussed by first-principles calculations.
Rhythms of life: antecedents and outcomes of work-family balance in employed parents.
Aryee, Samuel; Srinivas, E S; Tan, Hwee Hoon
2005-01-01
This study examined antecedents and outcomes of a fourfold taxonomy of work-family balance in terms of the direction of influence (work-family vs. family-work) and type of effect (conflict vs. facilitation). Respondents were full-time employed parents in India. Confirmatory factor analysis results provided evidence for the discriminant validity of M. R. Frone's (2003) fourfold taxonomy of work-family balance. Results of moderated regression analysis revealed that different processes underlie the conflict and facilitation components. Furthermore, gender had only a limited moderating influence on the relationships between the antecedents and the components of work-family balance. Last, work-family facilitation was related to the work outcomes of job satisfaction and organizational commitment.
Cai, Peng; Ruan, Wei; Zhou, Xiaodong; Ye, Cun; Wang, Aifeng; Chen, Xianhui; Lee, Dung-Hai; Wang, Yayu
2014-03-28
We use scanning tunneling microscopy to investigate the doping dependence of quasiparticle interference (QPI) in NaFe1-xCoxAs iron-based superconductors. The goal is to study the relation between nematic fluctuations and Cooper pairing. In the parent and underdoped compounds, where fourfold rotational symmetry is broken macroscopically, the QPI patterns reveal strong rotational anisotropy. At optimal doping, however, the QPI patterns are always fourfold symmetric. We argue this implies small nematic susceptibility and, hence, insignificant nematic fluctuation in optimally doped iron pnictides. Since TC is the highest this suggests nematic fluctuation is not a prerequistite for strong Cooper pairing.
In Vitro and In Vivo Antibacterial Activities of DK-507k, a Novel Fluoroquinolone
Otani, Tsuyoshi; Tanaka, Mayumi; Ito, Emi; Kurosaka, Yuichi; Murakami, Yoichi; Onodera, Kiyomi; Akasaka, Takaaki; Sato, Kenichi
2003-01-01
The antibacterial activities of DK-507k, a novel quinolone, were compared with those of other quinolones: ciprofloxacin, gatifloxacin, levofloxacin, moxifloxacin, sitafloxacin, and garenoxacin (BMS284756). DK-507k was as active as sitafloxacin and was as active as or up to eightfold more active than gatifloxacin, moxifloxacin, and garenoxacin against Streptococcus pneumoniae, methicillin-susceptible and methicillin-resistant Staphylococcus aureus, and coagulase-negative staphylococci. DK-507k was as active as or 4-fold more active than garenoxacin and 2- to 16-fold more active than gatifloxacin and moxifloxacin against ciprofloxacin-resistant strains of S. pneumoniae, including clinical isolates and in vitro-selected mutants with known mutations. DK-507k inhibited all ciprofloxacin-resistant strains of S. pneumoniae at 1 μg/ml. A time-kill assay with S. pneumoniae showed that DK-507k was more bactericidal than gatifloxacin and moxifloxacin. The activities of DK-507k against most members of the family Enterobacteriaceae were comparable to those of ciprofloxacin and equal to or up to 32-fold higher than those of gatifloxacin, levofloxacin, moxifloxacin, and garenoxacin. DK-507k was fourfold less active than sitafloxacin and ciprofloxacin against Pseudomonas aeruginosa, while it was two to four times more potent than levofloxacin, gatifloxacin, moxifloxacin, and garenoxacin against P. aeruginosa. In vivo, intravenous treatment with DK-507k was more effective than that with gatifloxacin and moxifloxacin against systemic infections caused by S. aureus, S. pneumoniae, and P. aeruginosa in mice. In a mouse model of pneumonia due to penicillin-resistant S. pneumoniae, DK-507k administered subcutaneously showed dose-dependent efficacy and eliminated the bacteria from the lungs, whereas gatifloxacin and moxifloxacin had no significant efficacy. Oral treatment with DK-507k was slightly more effective than that with ciprofloxacin in a rat model of foreign body-associated urinary tract infection caused by a P. aeruginosa isolate for which the MIC of DK-507k was fourfold higher than that of ciprofloxacin. Oral administration of DK-507k to rats achieved higher peak concentrations in serum and higher concentrations in cumulative urine than those achieved with ciprofloxacin. These data indicate the potential advantages of DK-507k over other quinolones for the treatment of a wide range of community-acquired infections. PMID:14638477
Heterogeneity Determination and Purification of Commercial Hen Egg-White Lysozyme
NASA Technical Reports Server (NTRS)
Thomas, B. R.; Vekilov, P. G.; Rosenberger, F.
1998-01-01
Hen egg-white lysozyme (HEWL) is widely used as a model protein, although its purity has not been adequately characterized by modern biochemical techniques. We have identified and quantified the protein heterogeneities in three commercial HEWL preparations by sodium dodecyl sulfate polyacrylamide gel electrophoresis with enhanced silver staining, reversed-phase fast protein liquid chromatography (FPLC) and immunoblotting with comparison to authentic protein standards. Depending on the source, the contaminating proteins totalled 1-6%(w/w) and consisted of ovotransferrin, ovalbumin, HEWL dimers, and polypeptides with approximate M(sub r) of 39 and 18 kDa. Furthermore, we have obtained gram quantities of electrophoretically homogeneous [> 99.9%(w/w)] HEWL by single-step semi-preparative scale cation-exchange FPLC with a yield of about 50%. Parallel studies of crystal growth kinetics, salt repartitioning and crystal perfection with this highly purified material showed fourfold increases in the growth-step velocities and significant enhancement in the structural homogeneity of HEWL crystals.
Epididymal genomics and the search for a male contraceptive.
Turner, T T; Johnston, D S; Jelinsky, S A
2006-05-16
This report represents the joint efforts of three laboratories, one with a primary interest in understanding regulatory processes in the epididymal epithelium (TTT) and two with a primary interest in identifying and characterizing new contraceptive targets (DSJ and SAJ). We have developed a highly refined mouse epididymal transcriptome and have used it as a starting point for determining genes in the human epididymis, which may serve as targets for male contraceptives. Our database represents gene expression information for approximately 39,000 transcripts, of which over 17,000 are significantly expressed in at least one segment of the mouse epididymis. Over 2000 of these transcripts are up- or down-regulated by at least four-fold between at least two segments. In addition, human databases have been queried to determine expression of orthologs in the human epididymis and the specificity of their expression in the epididymis. Genes highly regulated in the human epididymis and showing high tissue specificity are potential targets for male contraceptives.
The Dynamics of Glomerular Ultrafiltration in the Rat
Brenner, Barry M.; Troy, Julia L.; Daugharty, Terrance M.
1971-01-01
Using a unique strain of Wistar rats endowed with glomeruli situated directly on the renal cortical surface, we measured glomerular capillary pressures using servo-nulling micropipette transducer techniques. Pressures in 12 glomerular capillaries from 7 rats averaged 60 cm H2O, or approximately 50% of mean systemic arterial values. Wave form characteristics for these glomerular capillaries were found to be remarkably similar to those of the central aorta. From similarly direct estimates of hydrostatic pressures in proximal tubules, and colloid osmotic pressures in systemic and efferent arteriolar plasmas, the net driving force for ultrafiltration was calculated. The average value of 14 cm H2O is lower by some two-thirds than the majority of estimates reported previously based on indirect techniques. Single nephron GFR (glomerular filtration rate) was also measured in these rats, thereby permitting calculation of the glomerular capillary ultrafiltration coefficient. The average value of 0.044 nl sec−1 cm H2O−1 glomerulus−1 is at least fourfold greater than previous estimates derived from indirect observations. PMID:5097578
Hajiri, Tetsuya; Yoshida, Takuya; Filianina, Mariia; Jaiswal, Samridh; Borie, Benjamin; Asano, H; Zabel, Hartmut; Klaui, Mathias
2017-11-20
We report an unusual angular-dependent exchange bias effect in ferromagnet/antiferromagnet bilayers, where both ferromagnet and antiferromagnet are epitaxially grown. Numerical model calculations predict an approximately 45$^\\circ$ period for the sign switching of the exchange-bias field, depending on the ratio between magnetocrystalline anisotropy and exchange-coupling constant. The switching of the sign is indicative of a competition between a fourfold magnetocrystalline anisotropy of the ferromagnet and a unidirectional anisotropy field of the exchange coupling. This predicted unusual angular-dependent exchange bias and its magnetization switching process are confirmed by measurements on fully epitaxial Co$_3$FeN/MnN bilayers by longitudinal and transverse magneto-optic Kerr effect magnetometry. These results provide a deeper understanding of the exchange coupling phenomena in fully epitaxial bilayers with tailored materials and open up a complex switching energy landscape engineering by anisotropies. © 2017 IOP Publishing Ltd.
Schnabel, Renate B.; Yin, Xiaoyan; PhilimonGona; Larson, Martin G.; Beiser, Alexa S.; McManus, David D.; Newton-Cheh, Christopher; Lubitz, Steven A.; Magnani, Jared W.; Ellinor, Patrick T.; SudhaSeshadri; Wolf, Philip A; Vasan, Ramachandran S.; Benjamin, Emelia J.; Levy, Daniel
2015-01-01
Summary Background Comprehensive long-term data on atrial fibrillation trends in men and women are scant. Methods We investigated trends in atrial fibrillation incidence, prevalence, and risk factors, and in stroke and mortality following its onset in Framingham Heart Study participants (n=9511) from 1958 to 2007. To accommodate sex differences in atrial fibrillation risk factors and disease manifestations, sex-stratified analyses were performed. Findings During 50 years of observation (202,417 person-years), there were 1,544 new-onset atrial fibrillation cases (46.8% women). We observed about a fourfold increase in the age-adjusted prevalence and more than a tripling in age-adjusted incidence of atrial fibrillation (prevalence 20.4 versus 96.2 per 1000 person-years in men; 13.7 versus 49.4 in women; incidence rates in first versus last decade 3.7 versus 13.4 per 1000 person-years in men; 2.5 versus 8.6 in women, ptrend<0.0001). For atrial fibrillation diagnosed by ECG during routine Framingham examinations, age-adjusted prevalence increased (12.6versus 25.7 per 1000 person-years in men; 8.1 versus 11.8 in women, ptrend<0.0001). The age-adjusted incidence increased, but did not achieve statistical significance. Although the prevalence of most risk factors changed over time, their associated hazards for atrial fibrillation changed little. Multivariable-adjusted proportional hazards models revealed a 73.5% decline in stroke and a 25.4% decline in mortality following atrial fibrillation onset (ptrend=0.0001, ptrend=0.003, respectively). Interpretation Our data suggest that observed trends of increased incidence of atrial fibrillation in the community were partially due to enhanced surveillance. Stroke occurrence and mortality following atrial fibrillation onset declined over the decades, and prevalence increased approximately fourfold. The hazards for atrial fibrillation risk factors remained fairly constant. Our data indicate a need for measures to enhance early detection of atrial fibrillation through increased awareness coupled with targeted screening programs, and risk factor-specific prevention. PMID:25960110
Simultaneous reduction of nitrate and selenate by cell suspensions of selenium-respiring bacteria
Oremland, R.S.; Blum, J.S.; Bindi, A.B.; Dowdle, P.R.; Herbel, M.; Stolz, J.F.
1999-01-01
Washed-cell suspensions of Sulfurospirillum barnesii reduced selenate [Se(VI)] when cells were cultured with nitrate, thiosulfate, arsenate, or fumarate as the electron acceptor. When the concentration of the electron donor was limiting, Se(VI) reduction in whole cells was approximately fourfold greater in Se(VI)-grown cells than was observed in nitrate-grown cells; correspondingly, nitrate reduction was ~11-fold higher in nitrate-grown cells than in Se(VI)-grown cells. However, a simultaneous reduction of nitrate and Se(VI) was observed in both cases. At nonlimiting electron donor concentrations, nitrate- grown cells suspended with equimolar nitrate and selenate achieved a complete reductive removal of nitrogen and selenium oxyanions, with the bulk of nitrate reduction preceding that of selenate reduction. Chloramphenicol did not inhibit these reductions. The Se(VI)-respiring haloalkaliphile Bacillus arsenicoselenatis gave similar results, but its Se(VI) reductase was not constitutive in nitrate-grown cells. No reduction of Se(VI) was noted for Bacillus selenitireducens, which respires selenite. The results of kinetic experiments with cell membrane preparations of S. barnesii suggest the presence of constitutive selenate and nitrate reduction, as well as an inducible, high- affinity nitrate reductase in nitrate-grown cells which also has a low affinity for selenate. The simultaneous reduction of micromolar Se(VI) in the presence of millimolar nitrate indicates that these organisms may have a functional use in bioremediating nitrate-rich, seleniferous agricultural wastewaters. Results with 75Se-selenate tracer show that these organisms can lower ambient Se(VI) concentrations to levels in compliance with new regulations proposed for release of selenium oxyanions into the environment.
Stratification of breast cancer risk in women with atypia: a Mayo cohort study.
Degnim, Amy C; Visscher, Daniel W; Berman, Hal K; Frost, Marlene H; Sellers, Thomas A; Vierkant, Robert A; Maloney, Shaun D; Pankratz, V Shane; de Groen, Piet C; Lingle, Wilma L; Ghosh, Karthik; Penheiter, Lois; Tlsty, Thea; Melton, L Joseph; Reynolds, Carol A; Hartmann, Lynn C
2007-07-01
Atypical hyperplasia is a well-recognized risk factor for breast cancer, conveying an approximately four-fold increased risk. Data regarding long-term absolute risk and factors for risk stratification are needed. Women with atypical hyperplasia in the Mayo Benign Breast Disease Cohort were identified through pathology review. Subsequent breast cancers were identified via medical records and a questionnaire. Relative risks (RRs) were estimated using standardized incidence ratios, comparing the observed number of breast cancers with those expected based on Iowa Surveillance, Epidemiology, and End Results (SEER) data. Age, histologic factors, and family history were evaluated as risk modifiers. Plots of cumulative breast cancer incidence provided estimates of risk over time. With mean follow-up of 13.7 years, 66 breast cancers (19.9%) occurred among 331 women with atypia. RR of breast cancer with atypia was 3.88 (95% CI, 3.00 to 4.94). Marked elevations in risk were seen with multifocal atypia (eg, three or more foci with calcifications [RR, 10.35; 95% CI, 6.13 to 16.4]). RR was higher for younger women (< 45; RR, 6.76; 95% CI, 3.24 to 12.4). Risk was similar for atypical ductal and atypical lobular hyperplasia, and family history added no significant risk. Breast cancer risk remained elevated over 20 years, and the cumulative incidence approached 35% at 30 years. Among women with atypical hyperplasia, multiple foci of atypia and the presence of histologic calcifications may indicate "very high risk" status (> 50% risk at 20 years). A positive family history does not further increase risk in women with atypia.
Gastrostomy feeding in cerebral palsy: a systematic review
Sleigh, G; Brocklehurst, P
2004-01-01
Aims: To determine benefits and risks for gastrostomy or jejunostomy feeding compared with oral feeding for children with cerebral palsy. Methods: Systematic review. Search strategy: electronic databases—Cochrane Library, Medline, Embase, Cinahl, Lilacs, databases of theses, grey literature. Included: relevant systematic reviews, randomised controlled trials, observational studies, case reports. Excluded: non-systematic reviews and qualitative research. Participants: children with cerebral palsy. Intervention: use of gastrostomy or jejunostomy tube to provide nutrition. Outcome: evaluated outcome measures included death, growth, gastro-oesophageal reflux, other complications, psychosocial aspects, and caregiver wellbeing. Results: No relevant systematic reviews or randomised controlled trials were found. Two cohort studies, 15 case series, and eight case reports met the inclusion criteria. Eight studies specifically described percutaneous endoscopic gastrostomy as the intervention. Weight gain resulted from gastrostomy feeding in most cases. There was an approximately fourfold increased risk of death reported in one cohort study for the gastrostomy fed children. Many complications were reported, including potential for increased gastro-oesophageal reflux and fluid aspiration into the lungs. Conclusions: Benefits associated with gastrostomy or jejunostomy feeding are difficult to assess from the available evidence. Risks of gastrostomy, particularly in relation to surgical complications, have been described but the size of the risk could not be quantified. The finding of a higher death rate for children fed by gastrostomy may merely reflect the greater disability of these compared with orally fed children. Lack of available evidence and the substantial risk of bias in observational studies suggests that a well conducted randomised controlled trial of sufficient size will be needed to answer these problems. PMID:15155398
Torres, Mariana Andrade; Díaz, Rommy; Boguen, Rodrigo; Martins, Simone Maria Massami Kitamura; Ravagnani, Gisele Mouro; Leal, Diego Feitosa; Oliveira, Melissa de Lima; Muro, Bruno Bracco Donatelli; Parra, Beatriz Martins; Meirelles, Flávio Vieira; Papa, Frederico Ozanan; Dell'Aqua, José Antônio; Alvarenga, Marco Antônio; Moretti, Aníbal de Sant'Anna; Sepúlveda, Néstor; de Andrade, André Furugen Cesar
2016-01-01
Boar semen cryopreservation remains a challenge due to the extension of cold shock damage. Thus, many alternatives have emerged to improve the quality of frozen-thawed boar sperm. Although the use of seminal plasma arising from boar sperm-rich fraction (SP-SRF) has shown good efficacy; however, the majority of actual sperm evaluation techniques include a single or dual sperm parameter analysis, which overrates the real sperm viability. Within this context, this work was performed to introduce a sperm flow cytometry fourfold stain technique for simultaneous evaluation of plasma and acrosomal membrane integrity and mitochondrial membrane potential. We then used the sperm flow cytometry fourfold stain technique to study the effect of SP-SRF on frozen-thawed boar sperm and further evaluated the effect of this treatment on sperm movement, tyrosine phosphorylation and fertility rate (FR). The sperm fourfold stain technique is accurate (R2 = 0.9356, p > 0.01) for simultaneous evaluation of plasma and acrosomal membrane integrity and mitochondrial membrane potential (IPIAH cells). Centrifugation pre-cryopreservation was not deleterious (p > 0.05) for any analyzed variables. Addition of SP-SRF after cryopreservation was able to improve total and progressive motility (p < 0.05) when boar semen was cryopreserved without SP-SRF; however, it was not able to decrease tyrosine phosphorylation (p > 0.05) or improve IPIAH cells (p > 0.05). FR was not (p > 0.05) statistically increased by the addition of seminal plasma, though females inseminated with frozen-thawed boar semen plus SP-SRF did perform better than those inseminated with sperm lacking seminal plasma. Thus, we conclude that sperm fourfold stain can be used to simultaneously evaluate plasma and acrosomal membrane integrity and mitochondrial membrane potential, and the addition of SP-SRF at thawed boar semen cryopreserved in absence of SP-SRF improve its total and progressive motility.
Díaz, Rommy; Boguen, Rodrigo; Martins, Simone Maria Massami Kitamura; Ravagnani, Gisele Mouro; Leal, Diego Feitosa; Oliveira, Melissa de Lima; Muro, Bruno Bracco Donatelli; Parra, Beatriz Martins; Meirelles, Flávio Vieira; Papa, Frederico Ozanan; Dell’Aqua, José Antônio; Alvarenga, Marco Antônio; Moretti, Aníbal de Sant’Anna; Sepúlveda, Néstor
2016-01-01
Boar semen cryopreservation remains a challenge due to the extension of cold shock damage. Thus, many alternatives have emerged to improve the quality of frozen-thawed boar sperm. Although the use of seminal plasma arising from boar sperm-rich fraction (SP-SRF) has shown good efficacy; however, the majority of actual sperm evaluation techniques include a single or dual sperm parameter analysis, which overrates the real sperm viability. Within this context, this work was performed to introduce a sperm flow cytometry fourfold stain technique for simultaneous evaluation of plasma and acrosomal membrane integrity and mitochondrial membrane potential. We then used the sperm flow cytometry fourfold stain technique to study the effect of SP-SRF on frozen-thawed boar sperm and further evaluated the effect of this treatment on sperm movement, tyrosine phosphorylation and fertility rate (FR). The sperm fourfold stain technique is accurate (R2 = 0.9356, p > 0.01) for simultaneous evaluation of plasma and acrosomal membrane integrity and mitochondrial membrane potential (IPIAH cells). Centrifugation pre-cryopreservation was not deleterious (p > 0.05) for any analyzed variables. Addition of SP-SRF after cryopreservation was able to improve total and progressive motility (p < 0.05) when boar semen was cryopreserved without SP-SRF; however, it was not able to decrease tyrosine phosphorylation (p > 0.05) or improve IPIAH cells (p > 0.05). FR was not (p > 0.05) statistically increased by the addition of seminal plasma, though females inseminated with frozen-thawed boar semen plus SP-SRF did perform better than those inseminated with sperm lacking seminal plasma. Thus, we conclude that sperm fourfold stain can be used to simultaneously evaluate plasma and acrosomal membrane integrity and mitochondrial membrane potential, and the addition of SP-SRF at thawed boar semen cryopreserved in absence of SP-SRF improve its total and progressive motility. PMID:27529819
Cabello-Pasini, Alejandro; Munoz-Salazar, R.; Ward, D.H.
2003-01-01
Density, biomass, morphology, phenology and photosynthetic characteristics of Zostera marina were related to continuous measurements of in situ irradiance, attenuation coefficient and temperature at three coastal lagoons in Baja California, Mexico. In situ irradiance was approximately two-fold lower at San Quintin Bay (SQ) than at Ojo de Liebre Lagoon (OL) and San Ignacio Lagoon (SI). As a consequence of the greater irradiance plants at OL and SI were established 1 m deeper within the water column than those at SQ. At SQ, there was a four-fold variation in biomass of Z. marina caused by changes on shoot length and not shoot density, while at OL and SI biomass and shoot length did not fluctuate significantly throughout the year. Reproductive shoot density reached maximum values concomitantly with the greater irradiance during spring-summer, however, the density was approximately three-fold greater at SQ than at the southern coastal lagoons. While irradiance levels were two-fold greater at the southern lagoons, in general, photosynthetic characteristics were similar among all three lagoons. The hours of light saturated photosynthesis, calculated from their photosynthetic characteristics and irradiance measurements, suggest that photosynthesis of shoots from OL and SI are saturated for more than 6 h per day throughout the year, while shoots from SQ are likely light limited during approximately 15% of the year. Consequently, an increase in attenuation coefficient values in the water column will likely decrease light availability to Z. marina plants at SQ, potentially decreasing their survival.
Cabello-Pasini, Alejandro; Munoz-Salazar, R.; Ward, D.H.
2003-01-01
Density, biomass, morphology, phenology and photosynthetic characteristics of Zostera marina were related to continuous measurements of in situ irradiance, attenuation coefficient and temperature at three coastal lagoons in Baja California, Mexico. In situ irradiance was approximately two-fold lower at San Quintin Bay (SQ) than at Ojo de Liebre Lagoon (OL) and San Ignacio Lagoon (SI). As a consequence of the greater irradiance, plants at OL and SI were established 1 m deeper within the water column than those at SQ. At SQ, there was a four-fold variation in biomass of Z. marina caused by changes on shoot length and not shoot density, while at OL and SI biomass and shoot length did not fluctuate significantly throughout the year. Reproductive shoot density reached maximum values concomitantly with the greatest irradiance during spring-summer, however, the density was approximately three-fold greater at SQ than at the southern coastal lagoons. While irradiance levels were two-fold greater at the southern lagoons, in general, photosynthetic characteristics were similar among all three lagoons. The hours of light saturated photosynthesis, calculated from their photosynthetic characteristics and irradiance measurements, suggest that photosynthesis of shoots from OL and SI are saturated for more than 6 h per day throughout the year, while shoots from SQ are likely light limited during approximately 15% of the year. Consequently, an increase in attenuation coefficient values in the water column will likely decrease light availability to Z. marina plants at SQ, potentially decreasing their survival. ?? 2003 Elsevier Science B.V. All rights reserved.
Determinants of inadequate fruit and vegetable consumption amongst Portuguese adults.
Oliveira, A; Maia, B; Lopes, C
2014-04-01
A low consumption of fruit and vegetables (F&V) represents a high burden on health. The present study evaluates sociodemographic, lifestyle and anthropometric determinants of an inadequate consumption of F&V (<5 servings per day). Participants were randomly selected within the adult Porto population (n = 2485). Those with normal cognitive function and information on key variables were analysed (n = 2362). Diet was assessed by a validated food frequency questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression, after sex stratification and controlling for age, education, marital status, smoking, regular physical exercise and total energy intake. Older women and men had 37% and 67%, respectively, lower odds of inadequate F&V consumption (≥65 versus <40 years: OR = 0.63, 95% CI = 0.42-0.94; OR = 0.33, 95% CI = 0.20-0.56). More educated subjects (>12 versus <5 years) and those engaged in regular physical exercise had approximately 50% lower probability of F&V inadequacy compared to nonpractitioners, and this was similar in both sexes. On the other hand, female and male current smokers had 1.86- and 2.05-fold higher probabilities of having inadequate F&V consumption. Individuals consuming excessive alcohol (women: ≥15 g day(-1) ; men: ≥30 g day(-1) ) presented a two- and four-fold higher probability of having inadequate F&V consumption compared to nondrinkers (OR = 1.95, 95% CI = 1.38-2.77 in women; OR = 4.40, 95% CI = 2.70-7.18 in men). In both sexes, an inadequate consumption of F&V was more frequently found in younger, less educated and less physically active subjects with smoking and drinking habits. Strategies aiming to increase F&V consumption should consider these target groups that present a clustering of unhealthy lifestyles. © 2013 The British Dietetic Association Ltd.
Montgomery, R R; Zimmerman, T S
1978-01-01
Factor VIII-related antigen (VIIIag) is deficient in plasma and platelets of patients with severe von Willebrand's disease. This study reports a second von Willebrand's disease antigen (vWagII), distinct from VIIIag, that is also deficient in the platelets and plasma of patients with severe von Willebrand's disease. VIIIag and vWagII are separable by molecular exclusion chromatography, sucrose density gradient ultracentrifugation, and crossed immunoelectrophoresis. They show reactions of immunologic nonidentity with each other, and thus, do not share a precursor-product relationship. vWagII is released from normal platelets during blood clotting, accounting for a fourfold higher concentration of vWagII in serum over plasma. Images PMID:307007
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gerhard, F.; Schumacher, C.; Gould, C.
NiMnSb is a ferromagnetic half-metal which, because of its rich anisotropy and very low Gilbert damping, is a promising candidate for applications in information technologies. We have investigated the in-plane anisotropy properties of thin, molecular beam epitaxy-grown NiMnSb films as a function of their Mn concentration. Using ferromagnetic resonance to determine the uniaxial and four-fold anisotropy fields, (2K{sub U})/(M{sub s}) and (2K{sub 1})/(M{sub s}) , we find that a variation in composition can change the strength of the four-fold anisotropy by more than an order of magnitude and cause a complete 90° rotation of the uniaxial anisotropy. This provides valuablemore » flexibility in designing new device geometries.« less
Pulmonary cytomegalovirus infection: detection by Gallium-67 imaging in the transplant patient
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hamed, I.A.; Wenzl, J.E.; Leonard, J.C.
1979-03-01
Cytomegalovirus (CMV) infection is a frequent complication during the first few months following renal transplantation. The diagnosis is sometimes difficult but may be made by viral culture, a fourfold rise in the CMV antibody titer, or by demonstration of the CMV inclusions in the affected tissue. An increased pulmonary uptake of gallium citrate Ga 67 has been demonstrated following renal transplantation in two patients, each of whom had a fourfold rise in CMV complement fixing antibody titer, one of whom additionally had CMV inclusion bodies in a lung biopsy specimen prior to clinical or radiological demonstration of the pulmonary involvement.more » Gallium imaging, therefore, appears to be a valuable noninvasive test for early diagnosis of CMV pulmonary infections.« less
Fairley, Stacie J; Singh, Shree R; Yilma, Abebayehu N; Waffo, Alain B; Subbarayan, Praseetha; Dixit, Saurabh; Taha, Murtada A; Cambridge, Chino D; Dennis, Vida A
2013-01-01
We recently demonstrated by in vitro experiments that PLGA (poly D, L-lactide-co-glycolide) potentiates T helper 1 (Th1) immune responses induced by a peptide derived from the recombinant major outer membrane protein (rMOMP) of Chlamydia trachomatis, and may be a promising vaccine delivery system. Herein we evaluated the immune-potentiating potential of PLGA by encapsulating the full-length rMOMP (PLGA-rMOMP), characterizing it in vitro, and investigating its immunogenicity in vivo. Our hypothesis was that PLGA-rMOMP triggers Th1 immune responses in mice, which are desirable prerequisites for a C. trachomatis candidate nanovaccine. Physical-structural characterizations of PLGA-rMOMP revealed its size (approximately 272 nm), zeta potential (-14.30 mV), apparent spherical smooth morphology, and continuous slow release pattern. PLGA potentiated the ability of encapsulated rMOMP to trigger production of cytokines and chemokines by mouse J774 macrophages. Flow cytometric analyses revealed that spleen cells from BALB/c mice immunized with PLGA-rMOMP had elevated numbers of CD4+ and CD8+ T cell subsets, and secreted more rMOMP-specific interferon-gamma (Th1) and interleukin (IL)-12p40 (Th1/Th17) than IL-4 and IL-10 (Th2) cytokines. PLGA-rMOMP-immunized mice produced higher serum immunoglobulin (Ig)G and IgG2a (Th1) than IgG1 (Th2) rMOMP-specific antibodies. Notably, sera from PLGA-rMOMP-immunized mice had a 64-fold higher Th1 than Th2 antibody titer, whereas mice immunized with rMOMP in Freund's adjuvant had only a four-fold higher Th1 than Th2 antibody titer, suggesting primarily induction of a Th1 antibody response in PLGA-rMOMP-immunized mice. Our data underscore PLGA as an effective delivery system for a C. trachomatis vaccine. The capacity of PLGA-rMOMP to trigger primarily Th1 immune responses in mice promotes it as a highly desirable candidate nanovaccine against C. trachomatis.
Benedict, Jason B; Coppens, Philip
2010-03-10
The crystalline nanocluster phase, in which nanoscale metal oxide clusters are self-assembled in three-dimensional periodic arrays, is described. The crystalline assembly of nanoparticles functionalized with technologically relevant ligands offers the opportunity to obtain unambiguous structural information that can be combined with theoretical calculations based on the known geometry and used to interpret spectroscopic and other information. A series of Ti/O clusters up to approximately 2.0 nm in diameter have been synthesized and functionalized with the adsorbents catechol and isonicotinic acid. Whereas the isonicotinate is always adsorbed in a bridging monodentate mode, four different adsorption modes of catechol have been identified. The particles show a significantly larger variation of the Ti-O distances than observed in the known TiO(2) phases and exhibit both sevenfold overcoordination and five- and fourfold undercoordination of the Ti atoms. Theoretical calculations show only a moderate dependence of the catecholate net charge on the geometry of adsorption. All of the catechol-functionalized clusters have a deep-red color due to penetration of the highest occupied catechol levels into the band gap of the Ti/O particles. Spectroscopic measurements of the band gap of the Ti(17) cluster are in good agreement with the theoretical values and show a blue shift of approximately 0.22 eV relative to those reported for anatase nanoparticles.
The F-theory geometry with most flux vacua
Taylor, Washington; Wang, Yi -Nan
2015-12-28
Applying the Ashok-Denef-Douglas estimation method to elliptic Calabi-Yau fourfolds suggests that a single elliptic fourfold M max gives rise to O(10 272,000) F-theory flux vacua, and that the sum total of the numbers of flux vacua from all other F-theory geometries is suppressed by a relative factor of O(10 –3000). The fourfold M max arises from a generic elliptic fibration over a specific toric threefold base B max, and gives a geometrically non-Higgsable gauge group of E 8 9 × F 4 8 × (G 2 × SU(2)) 16, of which we expect some factors to be broken by G-fluxmore » to smaller groups. It is not possible to tune an SU(5) GUT group on any further divisors in M max, or even an SU(2) or SU(3), so the standard model gauge group appears to arise in this context only from a broken E 8 factor. Furthermore, the results of this paper can either be interpreted as providing a framework for predicting how the standard model arises most naturally in F-theory and the types of dark matter to be found in a typical F-theory compactification, or as a challenge to string theorists to explain why other choices of vacua are not exponentially unlikely compared to F-theory compactifications on M max.« less
The F-theory geometry with most flux vacua
DOE Office of Scientific and Technical Information (OSTI.GOV)
Taylor, Washington; Wang, Yi -Nan
Applying the Ashok-Denef-Douglas estimation method to elliptic Calabi-Yau fourfolds suggests that a single elliptic fourfold M max gives rise to O(10 272,000) F-theory flux vacua, and that the sum total of the numbers of flux vacua from all other F-theory geometries is suppressed by a relative factor of O(10 –3000). The fourfold M max arises from a generic elliptic fibration over a specific toric threefold base B max, and gives a geometrically non-Higgsable gauge group of E 8 9 × F 4 8 × (G 2 × SU(2)) 16, of which we expect some factors to be broken by G-fluxmore » to smaller groups. It is not possible to tune an SU(5) GUT group on any further divisors in M max, or even an SU(2) or SU(3), so the standard model gauge group appears to arise in this context only from a broken E 8 factor. Furthermore, the results of this paper can either be interpreted as providing a framework for predicting how the standard model arises most naturally in F-theory and the types of dark matter to be found in a typical F-theory compactification, or as a challenge to string theorists to explain why other choices of vacua are not exponentially unlikely compared to F-theory compactifications on M max.« less
Pilania, G.; Gubernatis, J. E.; Lookman, T.
2015-12-03
The role of dynamical (or Born effective) charges in classification of octet AB-type binary compounds between four-fold (zincblende/wurtzite crystal structures) and six-fold (rocksalt crystal structure) coordinated systems is discussed. We show that the difference in the dynamical charges of the fourfold and sixfold coordinated structures, in combination with Harrison’s polarity, serves as an excellent feature to classify the coordination of 82 sp–bonded binary octet compounds. We use a support vector machine classifier to estimate the average classification accuracy and the associated variance in our model where a decision boundary is learned in a supervised manner. Lastly, we compare the out-of-samplemore » classification accuracy achieved by our feature pair with those reported previously.« less
Anisotropic Josephson-vortex dynamics in layered organic superconductors
NASA Astrophysics Data System (ADS)
Yasuzuka, S.; Uji, S.; Satsukawa, H.; Kimata, M.; Terashima, T.; Koga, H.; Yamamura, Y.; Saito, K.; Akutsu, H.; Yamada, J.
2010-06-01
To study the anisotropic Josephson-vortex dynamics in the d-wave superconductors, the interplane resistance has been measured on layered organic superconductors κ-(ET)2Cu(NCS)2 and β-(BDA-TTP)2SbF6 under magnetic fields precisely parallel to the conducting planes. For κ-(ET)2Cu(NCS)2, in-plane angular dependence of the Josephson-vortex flow resistance is mainly described by the fourfold symmetry and dip structures appear when the magnetic field is applied parallel to the b- and c-axes. The obtained results have a relation to the d-wave superconducting gap symmetry. However, the absence of in-plane fourfold anisotropy was found for β-(BDA-TTP)2SbF6. The different anisotropic behavior is discussed in terms of the interlayer coupling strength.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pugliese, G.; Tilton, R.G.; Speedy, A.
1990-07-01
These studies were undertaken to assess the effects of increased galactose (v increased glucose) metabolism via the polyol pathway on vascular filtration function in the kidneys, eyes, nerves, and aorta. Quantitative radiolabeled tracer techniques were used to assess glomerular filtration rate (GFR) and regional tissue vascular clearance of plasma 131I-bovine serum albumin (BSA) in five groups of male Sprague-Dawley rats: nondiabetic controls, streptozotocin-diabetic rats, nondiabetic rats fed a 50% galactose diet, diabetic rats treated with sorbinil (an aldose reductase inhibitor), and galactose-fed rats treated with sorbinil. Sorbinil was added to the diet to provide a daily dose of approximately .2more » mmol/kg body weight. After 2 months of diabetes or galactose ingestion, albumin clearance was increased twofold to fourfold in the eye (anterior uvea, choroid, and retina), sciatic nerve, aorta, and kidney; GFR was increased approximately twofold and urinary excretion of endogenous albumin and IgG were increased approximately 10-fold. Sorbinil treatment markedly reduced or completely prevented all of these changes in galactose-fed, as well as in diabetic rats. These observations support the hypothesis that increased metabolism of glucose via the sorbitol pathway is of central importance in mediating virtually all of the early changes in vascular filtration function associated with diabetes in the kidney, as well as in the eyes, nerves, and aorta. On the other hand, renal hypertrophy in diabetic rats and polyuria, hyperphagia, and impaired weight gain in galactose-fed and in diabetic rats were unaffected by sorbinil and therefore are unlikely to be mediated by increased polyol metabolism.« less
Merritt, T A; Goldstein, M; Philips, R; Peverini, R; Iwakoshi, J; Rodriguez, A; Oshiro, B
2014-05-01
We reviewed the occurrence of prematurity, low birth weight, multiple gestations, frequency of stillbirths and maternity care-associated variables including hospital stay and hospital charges of women conceiving using assisted reproductive technology (ART) or artificial insemination (AI) compared with women with a history of infertility who conceived naturally, and all other naturally conceived pregnancies in California at non-federal hospitals between 2009 and 2011. At a single center, infants born after ART/AI were compared with infants provided care in the normal nursery. Publically available inpatient data sets from the California Office of Statewide Health Planning and Development for years 2009-2011 using data from all California non-federal hospitals were used to determine the impact of ART on a variety of pregnancy-related outcomes and infant characteristics. Infant data from a single center was used to determine hospital charges for infants delivered over an 18-month period to compare the hospital and physician charges indexed to similar charges for infants admitted to the 'normal' newborn nursery. Among ART/AI pregnancies, there was a 4-5-fold increase in stillbirths, compared with a 2-3-fold increase among women with infertility compared with other naturally conceiving women. ART/AI pregnancies underwent more cesarean sections (fourfold), and a near fourfold increase in the rate of preterm deliveries. Multiple gestations were increased 24-27-fold compared with naturally conceived pregnancies. Maternal hospital stay and hospital charges were increased among those undergoing ART/AI. Infant charges were increased multi-fold for singletons, twins and triplets delivered after ART/AI compared with naturally conceived infants. Multiple births, preterm births and a higher overall rate of fetal anomalies were found in California after ART/AI for 2009-2011. Cesarean section rates, longer length of maternal stay and hospital charges among women receiving ART/AI could be lowered if emphasis on elective single embryo transfers was a higher priority among providers. Charges for the care of infants delivered after ART/AI are substantially higher than among naturally conceived infants born late preterm or at term. Families seeking ART/AI need to be informed of the impact of these adverse pregnancy outcomes, including neonatal outcomes and charges for medical care for their infant(s), when considering ART/AI.
Reid, Howard O. N.; Kahwa, Ishenkumba A.; White, Andrew J. P.; Williams, David J.
1998-07-27
Synthetic, structural and luminescence studies of stoichiometric crown ether compounds of Mn(2+) in well-defined coordination environments were undertaken in an effort to understand the origin of emitting crystal defects found in cubic F23 [(K18C6)(4)MnBr(4)][TlBr(4)](2) crystals (Fender, N. S.; et al. Inorg. Chem. 1997, 36, 5539). The new compound [Mn(12C4)(2)][MnBr(4)](2)[N(CH(3))(4)](2) (3) features Mn(2+) ions in eight- and fourfold coordination environments of [Mn(12C4)(2)](2+) and MnBr(4)(2)(-) respectively, while Mn(2+) in [Mn(15C5)(H(2)O)(2)][TlBr(5)] (4) is in the sevenfold coordination polyhedron of [Mn(15C5)(H(2)O)(2)](2+). Crystal data for 3: monoclinic, P2(1)/c (No. 14); a = 14.131(3) Å, b = 12.158(1) Å, c = 14.239(2) Å, beta = 110.37(1) degrees, Z = 2, R1 = 0.039 and wR2 = 0.083. For 3, long-lived emission (77 K decay rate approximately 3 x 10 s(-)(1)) from [Mn(12C4)(2)](2+) (the first for eight-coordinate Mn(2+) in stoichiometric compounds) is observed (lambda(max) approximately 546 nm) along with that of the sensitizing MnBr(4)(2)(-) (lambda(max) approximately 513 nm), which is partially quenched. Emission from the seven-coordinate [Mn(15C5)(H(2)O)(2)](2+) species of 4 and [Mn(15C5)(H(2)O)(2)][MnBr(4)] (the first for seven-coordinate Mn(2+) in stoichiometric compounds) peaks at lambda(max) approximately 592 nm. Unusually intense absorptions attributable to the seven-coordinate species are observed at 317 ((2)T(2)((2)I) <-- (6)A(1)), 342 ((4)T(1)((4)P) <-- (6)A(1)), 406 ((4)E((4)G) <-- (6)A(1)), and 531 ((4)T(1)((4)G) <-- (6)A(1)) nm.
Klueter, Anke; Trapani, Jennifer; Archer, Frederick I; McIlroy, Shelby E; Coffroth, Mary Alice
2017-01-01
Many dinoflagellate microalgae of the genus Symbiodinium form successful symbioses with a large group of metazoans and selected protists. Yet knowledge of growth kinetics of these endosymbionts and their ecological and evolutionary implications is limited. We used a Bayesian biphasic generalized logistic model to estimate key parameters of the growth of five strains of cultured Symbiodinium, S. microadriaticum (cp-type A194; strain 04-503), S. microadriaticum (cp-type A194; strain CassKB8), S. minutum (cp-type B184; strain Mf 1.05b.01.SCI.01), S. psygmophilum (cp-type B224; strain Mf 11.05b.01) and S. trenchii (cp-type D206; strain Mf 2.2b), grown in four different combinations of temperature and light. Growth kinetics varied among Symbiodinium strains and across treatments. Biphasic growth was especially evident for S. minutum and S. psygmophilum across all treatments. Monophasic growth was more common when final asymptotic densities were relatively low (~ 200 million cells ml-1). All species tended to grow faster and / or reached a higher asymptote at 26°C than at 18°C. The fastest growth was exhibited by S. minutum, with an approximate four-fold increase in estimated cell density after 60 days. The strongest effect of light was seen in S. trenchii, in which increasing light levels resulted in a decrease in initial growth rate, and an increase in asymptotic density, time when growth rate was at its maximum, final growth rate, and maximum growth rate. Results suggest that Symbiodinium species have different photokinetic and thermal optima, which may affect their growth-related nutritional physiology and allow them to modify their response to environmental changes.
Changes in kynurenine pathway metabolism in Parkinson patients with L-DOPA-induced dyskinesia.
Havelund, Jesper F; Andersen, Andreas D; Binzer, Michael; Blaabjerg, Morten; Heegaard, Niels H H; Stenager, Egon; Faergeman, Nils J; Gramsbergen, Jan Bert
2017-09-01
L-3,4-Dihydroxyphenylalanine (L-DOPA) is the most effective drug in the symptomatic treatment of Parkinson's disease, but chronic use is associated with L-DOPA-induced dyskinesia in more than half the patients after 10 years of treatment. L-DOPA treatment may affect tryptophan metabolism via the kynurenine pathway. Altered levels of kynurenine metabolites can affect glutamatergic transmission and may play a role in the development of L-DOPA-induced dyskinesia. In this study, we assessed kynurenine metabolites in plasma and cerebrospinal fluid of Parkinson's disease patients and controls. Parkinson patients (n = 26) were clinically assessed for severity of motor symptoms (UPDRS) and L-DOPA-induced dyskinesia (UDysRS). Plasma and cerebrospinal fluid samples were collected after overnight fasting and 1-2 h after intake of L-DOPA or other anti-Parkinson medication. Metabolites were analyzed in plasma and cerebrospinal fluid of controls (n = 14), Parkinson patients receiving no L-DOPA (n = 8), patients treated with L-DOPA without dyskinesia (n = 8), and patients with L-DOPA-induced dyskinesia (n = 10) using liquid chromatography-mass spectrometry. We observed approximately fourfold increase in the 3-hydroxykynurenine/kynurenic acid ratio in plasma of Parkinson's patients with L-DOPA-induced dyskinesia. Anthranilic acid levels were decreased in plasma and cerebrospinal fluid of this patient group. 5-Hydroxytryptophan levels were twofold increased in all L-DOPA-treated Parkinson's patients. We conclude that a higher 3-hydroxykynurenine/kynurenic acid ratio in plasma may serve as a biomarker for L-DOPA-induced dyskinesia. Longitudinal studies including larger patients cohorts are needed to verify whether the changes observed here may serve as a prognostic marker for L-DOPA-induced dyskinesia. © 2017 International Society for Neurochemistry.
Contribution of NK3 tachykinin receptors to propulsion in the rabbit isolated distal colon.
Onori, L; Aggio, A; Taddei, G; Ciccocioppo, R; Severi, C; Carnicelli, V; Tonini, M
2001-06-01
The role of NK3 receptors in rabbit colonic propulsion has been investigated in vitro with the selective agonist, senktide, and two selective antagonists, SR142801 and SB222200. Peristalsis was elicited by distending a rubber balloon with 0.3 and 1.0 mL of water leading to a velocity of 2.2 and 2.8 mm s-1, respectively. At concentrations of 1 nM, senktide inhibited propulsion evoked by both distensions (range 25-40%), whereas at 6 and 60 nmol L-1 facilitated 'submaximal' propulsion by 30%. In the presence of Nomega-nitro-L-arginine (L-NNA, 200 micromol L-1), which per se caused a slight prokinetic effect, 1 nmol L-1 senktide markedly accelerated propulsion (range 35-50%). Hexamethonium (200 micromol L-1) had minor effects on propulsion. In its presence, 60 nmol L-1 senktide significantly inhibited propulsion induced by both stimuli (range 20-50%). SR142801 (0.3, 3 nmol L-1) and SB222200 (30, 300 nmol L-1) facilitated 'submaximal' propulsion (range 20-40%). Conversely, higher antagonist concentrations (SR142801: 30, 300 nM; SB222200: 1, 10 micromol L-1) inhibited propulsion to both distensions by 20%. A combination of SR142801 (300 nmol L-1) plus hexamethonium (200 micromol L-1) induced an approximately four-fold greater inhibition of propulsion than that induced by SR142801 alone. In conclusion, in the rabbit-isolated distal colon, a subset of NK3 receptors located on descending pathways mediates an inhibitory effect on propulsion by activating a NO-dependent mechanism. Another subset of NK3 receptors, located on ascending pathways mediates a facilitative effect involving a synergistic interaction with cholinergic nicotinic receptors.
McGavock, Jonathan M.; Hastings, Jeffrey L.; Snell, Peter G.; McGuire, Darren K.; Pacini, Eric L.; Mitchell, Jere H.
2009-01-01
Background In 1966, five 20-year-old men underwent a comprehensive physiological evaluation of the capacity for adaptation of the cardiovascular system in response to 3 weeks of bed rest and 8 weeks of heavy endurance training; these same participants were reevaluated before and after training at the age of 50. The aim of the present study was to reexamine these same men 40 years following the original assessments. Methods and Results In all three studies, minute ventilation and expired gases were analyzed during exercise testing with Douglas bag collection. Cardiac output (CO) was determined using the acetylene rebreathing technique. Compared with the original 30-year interval, the decline in maximal oxygen uptake (VO2max) (−11% vs −25%), maximal CO (+6% vs −11%), and maximal stroke volume (+10% vs −10%) were greater between 50 and 60 years of age. The annualized decline in VO2max (55 mL/min/y) between ages 50 and 60 was approximately fourfold higher than the decline between 20 and 50 years (12 mL/min/y). Conclusions In the original five participants of the Dallas Bed Rest and Training Study, VO2max declined after 40 years of living due to a balanced decrease in central and peripheral determinants of oxygen uptake. The rate of decline in VO2max and its components accelerated after the age of 50 years secondary to age and clinical comorbidities. The net proportional decline in VO2max for a period of 40 years of life was comparable with that experienced after 3 weeks of strict bed rest at the age of 20 (27% vs 26%, respectively). PMID:19196908
Voltage Preconditioning Allows Modulated Gene Expression in Neurons Using PEI-complexed siRNA
Sridharan, Arati; Patel, Chetan; Muthuswamy, Jit
2013-01-01
We present here a high efficiency, high viability siRNA-delivery method using a voltage-controlled chemical transfection strategy to achieve modulated delivery of polyethylenimine (PEI) complexed with siRNA in an in vitro culture of neuro2A cells and neurons. Low voltage pulses were applied to adherent cells before the administration of PEI-siRNA complexes. Live assays of neuro2a cells transfected with fluorescently tagged siRNA showed an increase in transfection efficiency from 62 ± 14% to 98 ± 3.8% (after −1 V). In primary hippocampal neurons, transfection efficiencies were increased from 30 ± 18% to 76 ± 18% (after −1 V). Negligible or low-level transfection was observed after preconditioning at higher voltages, suggesting an inverse relationship with applied voltage. Experiments with propidium iodide ruled out the role of electroporation in the transfection of siRNAs suggesting an alternate electro-endocytotic mechanism. In addition, image analysis of preconditioned and transfected cells demonstrates siRNA uptake and loading that is tuned to preconditioning voltage levels. There is approximately a fourfold increase in siRNA loading after preconditioning at −1 V compared with the same at ±2–3 V. Modulated gene expression is demonstrated in a functional knockdown of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in neuro2A cells using siRNA. Cell density and dendritic morphological changes are also demonstrated in modulated knockdown of brain derived neurotrophic factor (BDNF) in primary hippocampal neurons. The method reported here has potential applications in the development of high-throughput screening systems for large libraries of siRNA molecules involving difficult-to-transfect cells like neurons. PMID:23531602
Voltage Preconditioning Allows Modulated Gene Expression in Neurons Using PEI-complexed siRNA.
Sridharan, Arati; Patel, Chetan; Muthuswamy, Jit
2013-03-26
We present here a high efficiency, high viability siRNA-delivery method using a voltage-controlled chemical transfection strategy to achieve modulated delivery of polyethylenimine (PEI) complexed with siRNA in an in vitro culture of neuro2A cells and neurons. Low voltage pulses were applied to adherent cells before the administration of PEI-siRNA complexes. Live assays of neuro2a cells transfected with fluorescently tagged siRNA showed an increase in transfection efficiency from 62 ± 14% to 98 ± 3.8% (after -1 V). In primary hippocampal neurons, transfection efficiencies were increased from 30 ± 18% to 76 ± 18% (after -1 V). Negligible or low-level transfection was observed after preconditioning at higher voltages, suggesting an inverse relationship with applied voltage. Experiments with propidium iodide ruled out the role of electroporation in the transfection of siRNAs suggesting an alternate electro-endocytotic mechanism. In addition, image analysis of preconditioned and transfected cells demonstrates siRNA uptake and loading that is tuned to preconditioning voltage levels. There is approximately a fourfold increase in siRNA loading after preconditioning at -1 V compared with the same at ±2-3 V. Modulated gene expression is demonstrated in a functional knockdown of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in neuro2A cells using siRNA. Cell density and dendritic morphological changes are also demonstrated in modulated knockdown of brain derived neurotrophic factor (BDNF) in primary hippocampal neurons. The method reported here has potential applications in the development of high-throughput screening systems for large libraries of siRNA molecules involving difficult-to-transfect cells like neurons.Molecular Therapy-Nucleic Acids (2013) 2, e82; doi:10.1038/mtna.2013.10; published online 26 March 2013.
Embryotoxic and teratogenic effects of selenium in the diet of mallards
Hoffman, D.J.; Heinz, G.H.
1988-01-01
Mallards (Anas platyrhynchos) were fed a control diet, diets containing 1, 5, 10, or 25 ppm Se as sodium selenite, or a diet containing 10 ppm Se as seleno-DL-methionine in the first of two experiments. Selenium at 10 ppm as selenomethionine or 25 ppm as sodium selenite caused a 40-44% decrease in the total number of eggs that hatched compared to controls. Selenium at 25 ppm (sodium selenite) resulted in a 19% decrease in mean embryonic weight at 18 d of incubation, accompanied by a 6% decrease in crown-rump length. Ten parts per million Se as selenomethionine was more teratogenic than sodium selenite at 25 ppm. Selenomethionine (10 ppm Se) resulted in an incidence of 13.1% malformations that were often multiple, whereas sodium selenite (10 and 25 ppm Se) resulted in 3.6 and 4.2% malformations. The teratogenicity of selenomethionine was confirmed in a second experiment in which mallards received 1, 2, 4, 8, or 16 ppm Se as selenomethionine, resulting in 0.9, 0.5, 1.4, 6.8, and 67.9% malformations, respectively. These malformations included hydrocephaly, microphthalmia, lower bill defects, and foot defects with ectrodactyly. Both forms of selenium increased the incidence of edema and stunted embryonic growth. Selenomethionine (10 ppm Se) resulted in a significant increase of approximately 40% in plasma glutathione peroxidase activity and a 70% increase in sorbitol dehydrogenase activity (indicative of hepatotoxicity) in hatchlings. Sodium selenite (25 ppm Se) resulted in fourfold elevation in plasma uric acid concentration, indicative of renal alteration. Selenomethionine accumulated much better in eggs than did sodium selenite. These findings indicate that selenomethionine is considerably more teratogenic and generally more embryotoxic than sodium selenite, probably due to higher uptake of selenomethionine.
Metabolism of d-Arabinose: Origin of a d-Ribulokinase Activity in Escherichia coli1
LeBlanc, Donald J.; Mortlock, Robert P.
1971-01-01
The kinase responsible for the phosphorylation of d-ribulose was purified 45.5-fold from a strain of Escherichia coli K-12 capable of growth on d-arabinose with no separation of d-ribulo- or l-fuculokinase activities. Throughout the purification, the ratios of activities remained essentially constant. A nonadditive effect of combining both substrates in an assay mixture; identical Km values for adenosine triphosphate with either l-fuculose or d-ribulose as substrate; and, the irreversible loss of activity on both substrates, after removal of magnesium ions from the enzyme preparation, suggest that the dual activity is due to the same enzyme. A fourfold greater affinity of the enzyme for l-fuculose than for d-ribulose, as well as a higher relative activity on l-fuculose, suggest that the natural substrate for this enzyme is l-fuculose. The product of the purified enzyme, with d-ribulose as substrate, was prepared. The ratio of total phosphorous to ribulose phosphate was 1.01:1, indicating that the product was ribulose monophosphate. The behavior of the kinase product in the cysteine-carbazole and orcinol reactions, as well as the results of periodate oxidation assays, provided evidence that it was not d-ribulose-5-phosphate. Reaction of this compound with a cell-free extract of E. coli possessing l-fuculose-l-phosphate aldolase activity resulted in the production of dihydroxyacetone phosphate and glycolaldehyde. The kinase product failed to reduce 2,3,5-triphenyltetrazolium and possessed a half-life of approximately 1.5 min in the presence of 1 n HCl at 100 C. These properties suggested that the phosphate group was attached to carbon atom 1 of d-ribulose. PMID:4323967
Villa, Max M; Wang, Liping; Huang, Jianping; Rowe, David W; Wei, Mei
2016-11-01
Bone tissue engineering using biomaterial scaffolds and culture-expanded osteoprogenitor cells has been demonstrated in several studies; however, it is not yet a clinical reality. One challenge is the optimal design of scaffolds for cell delivery and the identification of scaffold parameters that can delineate success and failure in vivo. Motivated by a previous experiment in which a batch of lyophilized collagen-hydroxyapatite (HA) scaffolds displayed modest bone formation in vivo, despite having large pores and high porosity, we began to investigate the effect of scaffold permeability on bone formation. Herein, we fabricated scaffolds with a permeability of 2.17 ± 1.63 × 10 -9 m 4 /(N s) and fourfold higher using a sacrificial gelatin porogen. Scaffolds were seeded with mouse bone marrow stromal cells carrying a fluorescent reporter for osteoblast differentiation and implanted into critical-size calvarial defects in immunodeficient mice. The porogen scaffold group containing a 1:1 ratio of solids to beads was significantly more radiopaque than the scaffold group without the bead porogen 3 weeks after implantation. Quantitative histomorphometry uncovered the same trend between the 1:1 group and scaffolds without porogen found in the radiographic data; however, this was not statistically significant here. Taken together, the X-ray and histology suggest that the 1:1 ratio of porogen to scaffold solids, resulting in a fourfold increase in permeability, may enhance bone formation when compared to scaffolds without porogen. Scaffold permeability can be a useful quality control measure before implantation and this practice should improve the consistency and efficacy of cell-based bone tissue engineering. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1580-1590, 2016. © 2015 Wiley Periodicals, Inc.
Alcohol Abuse and Other Psychiatric Disorders
... found that those with a history of alcohol dependence (even former drinkers), had a more than fourfold- ... episode than those without a history of alcohol dependence. It isn’t always clear which comes first: ...
The Danger of Dichotomizing Continuous Variables: A Visualization
ERIC Educational Resources Information Center
Kuss, Oliver
2013-01-01
Four rather different scatterplots of two variables X and Y are given, which, after dichotomizing X and Y, result in identical fourfold-tables misleadingly showing no association. (Contains 1 table and 1 figure.)
Strain-induced formation of fourfold symmetric SiGe quantum dot molecules.
Zinovyev, V A; Dvurechenskii, A V; Kuchinskaya, P A; Armbrister, V A
2013-12-27
The strain field distribution at the surface of a multilayer structure with disklike SiGe nanomounds formed by heteroepitaxy is exploited to arrange the symmetric quantum dot molecules typically consisting of four elongated quantum dots ordered along the [010] and [100] directions. The morphological transition from fourfold quantum dot molecules to continuous fortresslike quantum rings with an increasing amount of deposited Ge is revealed. We examine key mechanisms underlying the formation of lateral quantum dot molecules by using scanning tunneling microscopy and numerical calculations of the strain energy distribution on the top of disklike SiGe nanomounds. Experimental data are well described by a simple thermodynamic model based on the accurate evaluation of the strain dependent part of the surface chemical potential. The spatial arrangement of quantum dots inside molecules is attributed to the effect of elastic property anisotropy.
NASA Astrophysics Data System (ADS)
Braun, A. P.; Watari, T.
2015-01-01
The four-form field strength in F-theory compactifications on Calabi-Yau four-folds takes its value in the middle cohomology group H 4. The middle cohomology is decomposed into a vertical, a horizontal and a remaining component, all three of which are present in general. We argue that a flux along the remaining or vertical component may break some symmetry, while a purely horizontal flux does not influence the unbroken part of the gauge group or the net chirality of charged matter fields. This makes the decomposition crucial to the counting of flux vacua in the context of F-theory GUTs. We use mirror symmetry to derive a combinatorial formula for the dimensions of these components applicable to any toric Calabi-Yau hypersurface, and also make a partial attempt at providing a geometric characterization of the four-cycles Poincaré dual to the remaining component of H 4. It is also found in general elliptic Calabi-Yau fourfolds supporting SU(5) gauge symmetry that a remaining component can be present, for example, in a form crucial to the symmetry breaking SU(5) - → SU(3) C × SU(2) L × U(1) Y . The dimension of the horizontal component is used to derive an estimate of the statistical distribution of the number of generations and the rank of 7-brane gauge groups in the landscape of F-theory flux vacua.
Chen, Lin-Yuan; Tang, Ping-Han; Wu, Ten-Ming
2016-07-14
In terms of the local bond-orientational order (LBOO) parameters, a cluster approach to analyze local structures of simple liquids was developed. In this approach, a cluster is defined as a combination of neighboring seeds having at least nb local-orientational bonds and their nearest neighbors, and a cluster ensemble is a collection of clusters with a specified nb and number of seeds ns. This cluster analysis was applied to investigate the microscopic structures of liquid Ga at ambient pressure (AP). The liquid structures studied were generated through ab initio molecular dynamics simulations. By scrutinizing the static structure factors (SSFs) of cluster ensembles with different combinations of nb and ns, we found that liquid Ga at AP contained two types of cluster structures, one characterized by sixfold orientational symmetry and the other showing fourfold orientational symmetry. The SSFs of cluster structures with sixfold orientational symmetry were akin to the SSF of a hard-sphere fluid. On the contrary, the SSFs of cluster structures showing fourfold orientational symmetry behaved similarly as the anomalous SSF of liquid Ga at AP, which is well known for exhibiting a high-q shoulder. The local structures of a highly LBOO cluster whose SSF displayed a high-q shoulder were found to be more similar to the structure of β-Ga than those of other solid phases of Ga. More generally, the cluster structures showing fourfold orientational symmetry have an inclination to resemble more to β-Ga.
NASA Technical Reports Server (NTRS)
Komarova, S. V.; Ataullakhanov, F. I.; Globus, R. K.
2000-01-01
To evaluate the relationship between osteoblast differentiation and bioenergetics, cultured primary osteoblasts from fetal rat calvaria were grown in medium supplemented with ascorbate to induce differentiation. Before ascorbate treatment, the rate of glucose consumption was 320 nmol. h(-1). 10(6) cells(-1), respiration was 40 nmol. h(-1). 10(6) cells(-1), and the ratio of lactate production to glucose consumption was approximately 2, indicating that glycolysis was the main energy source for immature osteoblasts. Ascorbate treatment for 14 days led to a fourfold increase in respiration, a threefold increase in ATP production, and a fivefold increase in ATP content compared with that shown in immature cells. Confocal imaging of mitochondria stained with a transmembrane potential-sensitive vital dye showed that mature cells possessed abundant amounts of high-transmembrane-potential mitochondria, which were concentrated near the culture medium-facing surface. Acute treatment of mature osteoblasts with metabolic inhibitors showed that the rate of glycolysis rose to maintain the cellular energy supply constant. Thus progressive differentiation coincided with changes in cellular metabolism and mitochondrial activity, which are likely to play key roles in osteoblast function.
Correlates of invalid neuropsychological test performance after traumatic brain injury.
Donders, Jacobus; Boonstra, Tyler
2007-03-01
To investigate external correlates of invalid test performance after traumatic brain injury, as assessed by the California Verbal Learning Test - Second Edition (CVLT-II) and Word Memory Test (WMT). Consecutive 2-year series of rehabilitation referrals with a diagnosis of traumatic brain injury (n = 87). Logistic regression analysis was used to determine which demographic and neurological variables best differentiated those with vs. without actuarial CVLT-II or WMT evidence for invalid responding. Twenty-one participants (about 24%) performed in the invalid range. The combination of a premorbid psychiatric history with minimal or no coma was associated with an approximately four-fold increase in the likelihood of invalid performance. Premorbid psychosocial complicating factors constitute a significant threat to validity of neuropsychological test results after (especially mild) traumatic brain injury. At the same time, care should be taken to not routinely assume that all persons with mild traumatic brain injury and premorbid psychiatric histories are simply malingering. The WMT appears to be a promising instrument for the purpose of identifying those cases where neuropsychological test results are confounded by factors not directly related to acquired cerebral impairment.
Exciton Emission Intensity Modulation of Monolayer MoS2 via Au Plasmon Coupling
Mukherjee, B.; Kaushik, N.; Tripathi, Ravi P. N.; Joseph, A. M.; Mohapatra, P. K.; Dhar, S.; Singh, B. P.; Kumar, G. V. Pavan; Simsek, E.; Lodha, S.
2017-01-01
Modulation of photoluminescence of atomically thin transition metal dichalcogenide two-dimensional materials is critical for their integration in optoelectronic and photonic device applications. By coupling with different plasmonic array geometries, we have shown that the photoluminescence intensity can be enhanced and quenched in comparison with pristine monolayer MoS2. The enhanced exciton emission intensity can be further tuned by varying the angle of polarized incident excitation. Through controlled variation of the structural parameters of the plasmonic array in our experiment, we demonstrate modulation of the photoluminescence intensity from nearly fourfold quenching to approximately threefold enhancement. Our data indicates that the plasmonic resonance couples to optical fields at both, excitation and emission bands, and increases the spontaneous emission rate in a double spacing plasmonic array structure as compared with an equal spacing array structure. Furthermore our experimental results are supported by numerical as well as full electromagnetic wave simulations. This study can facilitate the incorporation of plasmon-enhanced transition metal dichalcogenide structures in photodetector, sensor and light emitter applications. PMID:28134260
NASA Astrophysics Data System (ADS)
Pasquini, Pedro; Chuliá, Salvador Centelles; Valle, J. W. F.
2017-05-01
Here we study the pattern of neutrino oscillations emerging from a previously proposed warped standard model construction incorporating Δ (27 ) flavor symmetry [J. High Energy Phys. 01 (2016) 007, 10.1007/JHEP01(2016)007]. In addition to a complete description of fermion masses, the model predicts the lepton mixing matrix in terms of two parameters. The good measurement of θ13 makes these two parameters tightly correlated, leading to an approximate one-parameter description of neutrino oscillations. We find secondary minima for the C P phase absent in the general unconstrained oscillation scenario and determine the fourfold degenerate sharp correlation between the physical C P phase δC P and the atmospheric mixing angle θ23. This implies that maximal θ23 correlates with maximal leptonic C P violation. We perform a realistic estimate of the total neutrino and antineutrino event numbers expected at long baseline oscillation experiments T2K, NOvA, and the upcoming DUNE proposal. We show how an improved knowledge of the C P phase will probe the model in a significant way.
Gerhardsson, Lars; Balogh, Istvan; Hambert, Per-Arne; Hjortsberg, Ulf; Karlsson, Jan-Erik
2005-01-01
The aim of the present study was to compare the development of vibration white fingers (VWF) in workers in relation to different ways of exposure estimation, and their relationship to the standard ISO 5349, annex A. Nineteen vibration exposed (grinding machines) male workers completed a questionnaire followed by a structured interview including questions regarding their estimated hand-held vibration exposure. Neurophysiological tests such as fractionated nerve conduction velocity in hands and arms, vibrotactile perception thresholds and temperature thresholds were determined. The subjective estimation of the mean daily exposure-time to vibrating tools was 192 min (range 18-480 min) among the workers. The estimated mean exposure time calculated from the consumption of grinding wheels was 42 min (range 18-60 min), approximately a four-fold overestimation (Wilcoxon's signed ranks test, p<0.001). Thus, objective measurements of the exposure time, related to the standard ISO 5349, which in this case were based on the consumption of grinding wheels, will in most cases give a better basis for adequate risk assessment than self-exposure assessment.
Agricultural Pesticide Management in Thailand: Situation and Population Health Risk
Panuwet, Parinya; Siriwong, Wattasit; Prapamontol, Tippawan; Ryan, P. Barry; Fiedler, Nancy; Robson, Mark G.; Barr, Dana Boyd
2012-01-01
As an agricultural country and one of the world’s major food exporters, Thailand relies heavily on the use of pesticides to protect crops and increase yields. During the past decade, the Kingdom of Thailand has experienced an approximate four-fold increase in pesticide use. This increase presents a challenge for the Royal Thai Government in effectively managing and controlling pesticide use based upon the current policies and legal infrastructure. We have reviewed several key components for managing agricultural pesticides in Thailand. One of the main obstacles to effective pesticide regulation in Thailand is the lack of a consolidated, uniform system designed specifically for pesticide management. This deficit has weakened the enforcement of existing regulations, resulting in misuse/overuse of pesticides, and consequently, increased environmental contamination and human exposure. This article provides a systematic review of how agricultural pesticides are regulated in Thailand. In addition, we provide our perspectives on the current state of pesticide management, the potential health effects of widespread, largely uncontrolled use of pesticides on the Thai people and ways to improve pesticide management in Thailand. PMID:22308095
Ashton-Miller, J A; Yeh, M W; Richardson, J K; Galloway, T
1996-05-01
To test the hypothesis that use of a cane in the nondominant hand during challenging balance tasks would significantly decrease loss of balance in patients with peripheral neuropathy while transferring from bipedal to unipedal stance on an unsteady surface. Nonrandomized control study. Tertiary-care institution. Eight consecutive patients with peripheral neuropathy (PN) and eight age- and gender-matched controls (C) with a mean (SD) age of 65 (8.2) years. Subjects were asked to transfer their weight onto their right foot, despite a rapid +/- 2 degrees or +/- 4 degrees frontal plane tilt of the support surface at 70% of weight transfer, and balance unipedally for at least 3 seconds. The efficacy of their weight transfer was evaluated over 112 consecutive randomized and blocked trials by calculating loss of balance as failure rates (%FR) with and without visual feedback, and with and without use of a cane in the nondominant (left) hand. Results were analyzed using a 2 x 2 x 2 x 2 x 2 repeated-measures analysis of variance (rm-ANOVA) and post hoc t tests. The rm-ANOVA showed that the FR of the PN subjects (47.6% [18.1%]) was significantly higher than C (29.2% [15.2%], p = .036). Removing visual feedback, simulating the dark of night, increased the FR fourfold (p = .000). Use of a cane in the contralateral nondominant hand significantly reduced the FR (p = .000), particularly in the PN group (cane x disease interaction: p = .055). Post hoc t tests showed that with or without visual feedback, the cane reduced the FR of the PN group fourfold and enabled them to perform more reliably than matched controls not using a cane (p = .011). An inversion perturbation resulted in a higher FR than an eversion perturbation (p = .007). The PN group employed larger mean peak cane forces (21.9% BW) than C (13.6% BW) in restoring their balance (p = .000). Use of a cane by PN patients significantly reduced their risk of losing balance on unstable surfaces, especially under low-light conditions.
Korman, Josh; Kaplinski, Matthew; Melis, Theodore S.
2010-01-01
High-flow experiments (HFEs) from Glen Canyon Dam are primarily intended to conserve fine sediment and improve habitat conditions for native fish in the Colorado River as it flows through Grand Canyon National Park, Arizona. These experimental flows also have the potential to affect the rainbow trout (Oncorhynchus mykiss) population in the Lees Ferry tailwater reach immediately below the dam, which supports a highly valued recreational fishery and likely influences the abundance of rainbow trout in Grand Canyon. Understanding how flow regimes affect the survival and growth of juvenile rainbow trout is critical to interpreting trends in adult abundance. This study reports on the effects of HFEs in 2004 and 2008 on early life stages of rainbow trout in the Lees Ferry reach on the basis of monthly sampling of redds (egg nests) and the abundance of the age-0 trout (fertilization to about 1 to 2 months from emergence) and their growth during a 7-year period between 2003 and 2009. Multiple lines of evidence indicate that the March 2008 HFE resulted in a large increase in early survival rates of age-0 trout because of an improvement in habitat conditions. A stock-recruitment analysis demonstrated that age-0 abundance in July 2008 was more than fourfold higher than expected, given the number of viable eggs that produced these fish. A hatch-date analysis showed that early survival rates were much higher for cohorts that hatched about 1 month after the 2008 HFE (about April 15, 2008) relative to those fish that hatched before this date. These cohorts, fertilized after the 2008 HFE, would have emerged into a benthic invertebrate community that had recovered, and was possibly enhanced by, the HFE. Interannual differences in growth of age-0 trout, determined on the basis of otolith microstructure, support this hypothesis. Growth rates in the summer and fall of 2008 (0.44 mm/day) were virtually the same as in 2006 (0.46 mm/day), the highest recorded during 6 years, even though abundance was eightfold greater in 2008. We speculate that the 60-hour-long 2008 HFE (with peak magnitude about twice that of the annual peak flow during the previous 4 years) increased interstitial spaces in the gravel bed substrate and food availability or quality, leading to higher early survival of recently emerged trout and better growth of these fish through summer and fall. Abundance in 2009 was more than twofold higher than expected, given the estimated number of viable eggs deposited in that year, perhaps indicating that the effect of the 2008 HFE on early life stages was somewhat persistent. In a 3-week interval that spanned the November 2004 HFE, abundance of age-0 trout that were approximately 7 months old from hatch experienced about a threefold decline, compared to the approximately twofold decrease observed between November and December 2008. Abundance of age-0 trout that were approximately 10 months old from hatch was very similar across sampling trips that spanned the March 2008 HFE. It is uncertain whether the decline in abundance after the November 2004 HFE was the result of higher flow-induced mortality or higher flow-induced downstream dispersal. A focused monitoring effort in Marble Canyon (the reach immediately downstream of the Lees Ferry tailwater) before and after future HFEs is recommended to resolve this uncertainty. Relatively detailed monitoring of early life stages-such as the program described in this study-is essential to establish linkages between Glen Canyon Dam operations, or possibly other factors, and trends in the abundance of important nonnative and native fish populations living downstream within Grand Canyon National Park.
NASA Astrophysics Data System (ADS)
Chakraborty, Jayasree; Langdon-Embry, Liana; Escalon, Joanna G.; Allen, Peter J.; Lowery, Maeve A.; O'Reilly, Eileen M.; Do, Richard K. G.; Simpson, Amber L.
2016-03-01
Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death in the United States. The five-year survival rate for all stages is approximately 6%, and approximately 2% when presenting with distant disease.1 Only 10-20% of all patients present with resectable disease, but recurrence rates are high with only 5 to 15% remaining free of disease at 5 years. At this time, we are unable to distinguish between resectable PDAC patients with occult metastatic disease from those with potentially curable disease. Early classification of these tumor types may eventually lead to changes in initial management including the use of neoadjuvant chemotherapy or radiation, or in the choice of postoperative adjuvant treatments. Texture analysis is an emerging methodology in oncologic imaging for quantitatively assessing tumor heterogeneity that could potentially aid in the stratification of these patients. The present study derives several texture-based features from CT images of PDAC patients, acquired prior to neoadjuvant chemotherapy, and analyzes their performance, individually as well as in combination, as prognostic markers. A fuzzy minimum redundancy maximum relevance method with leave-one-image-out technique is included to select discriminating features from the set of extracted features. With a naive Bayes classifier, the proposed method predicts the 5-year overall survival of PDAC patients prior to neoadjuvant therapy and achieves the best results in terms of the area under the receiver operating characteristic curve of 0:858 and accuracy of 83:0% with four-fold cross-validation techniques.
Regulatory aspects of the glutamylation of methotrexate in cultured hepatoma cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nimec, Z.; Galivan, J.
1983-10-15
The glutamylation of methotrexate has been evaluated in H35 hepatoma cells in vitro as a function of the conditions of culture. Glutamylation yields methotrexate polyglutamate with two to five additional glutamate residues and is a saturable process. The rate of glutamylation increases little above 10 microM extracellular methotrexate which corresponds to an intracellular concentration of approximately 4 microM. The rate of glutamylation measured over a 6-h period was stimulated by a reduction in cellular folates and prior incubation of the cells with insulin. Glutamylation was also more rapid in dividing cultures than in confluent cells. The combination of insulin inclusionmore » and folate reduction, which was additive, caused approximately a fourfold increase in the rate of glutamylation over control cells under the conditions tested. The maximal rate of methotrexate glutamylation, which was 100 nmol/g/h, occurred in folate-depleted, insulin-supplemented cells. Supplementing folate-depleted cells with reduced folate coenzymes caused the glutamylation to be reduced by more than 90%. In addition to showing that folates can modify the rates of methotrexate polyglutamate formation, data are presented suggesting that methotrexate polyglutamates can regulate their own synthesis. The consequences of the formation of these retained forms of methotrexate in H35 hepatoma cells and the effects of potential regulators of this process are discussed in terms of the glutamylation of folates in the cells and the chemotherapeutic effects of antifolates.« less
NASA Astrophysics Data System (ADS)
Zaitseva, A. F.; Konyukhov, I. V.; Kazimirko, Yu. V.; Pogosyan, S. I.
2018-03-01
Onega Bay waters are characterized by a high content of chromophoric dissolved organic matter (CDOM). The absorbance spectra and fluorescence intensity (excitation wavelength 455 nm, emission wavelength >680 nm) were used to assess the distribution of CDOM content in water filtered through a GF/F filter. The CDOM content at different points in Onega Bay showed more than a fourfold difference, as inferred from the measured values. The CDOM content in surface waters was, as a rule, higher than in the deeper horizons. A higher CDOM content was measured near the Onega River, near the middle part of the Onega shore, and near the Pomor shore opposite the town of Belomorsk. River runoff is the major source of CDOM in Onega Bay water. The CDOM chemical composition in Onega Bay waters was heterogeneous. The ratio of the fluorescence intensity to the absorbance value was higher near the mouths of rivers and in intensive mixing zones than in water characterized by high salinity. A highly significant linear correlation ( R 2 = 0.7825) between water salinity and CDOM fluorescence intensity was demonstrated. The contribution of fluorescent compounds to river runoff CDOM is substantially higher than the contribution to the composition marine CDOM.
Methadone adverse reaction presenting with large increase in plasma methadone binding: a case series
2011-01-01
Introduction The use of methadone as an analgesic is on the increase, but it is widely recognized that the goal of predictable and reproducible dosing is confounded by considerable variability in methadone pharmacokinetics, and unpredictable side effects that include sedation, respiratory depression and cardiac arrhythmias. The mechanisms underlying these unpredictable effects are frequently unclear. Here, to the best of our knowledge we present the first report of an association between accidental methadone overexposure and increased plasma protein binding, a new potential mechanism for drug interactions with methadone. Case presentation We describe here the cases of two patients who experienced markedly different responses to the same dose of methadone during co-administration of letrozole. Both patients were post-menopausal Caucasian women who were among healthy volunteers participating in a clinical trial. Under the trial protocol both patients received 6 mg of intravenous methadone before and then after taking letrozole for seven days. One woman (aged 59) experienced symptoms consistent with opiate overexposure after the second dose of methadone that were reversed by naloxone, while the other (aged 49) did not. To understand the etiology of this event, we measured methadone pharmacokinetics in both patients. In our affected patient only, a fourfold to eightfold increase in methadone plasma concentrations after letrozole treatment was observed. Detailed pharmacokinetic analysis indicated no change in metabolism or renal elimination in our patient, but the percentage of unbound methadone in the plasma decreased 3.7-fold. As a result, the volume of distribution of methadone decreased approximately fourfold. The increased plasma binding in our affected patient was consistent with observed increases in plasma protein concentrations. Conclusions The marked increase in the total plasma methadone concentration observed in our patient, and the enhanced pharmacodynamic effect, appear primarily due to a reduced volume of distribution. The extent of plasma methadone binding may help to explain the unpredictability of its pharmacokinetics. Changes in volume of distribution due to plasma binding may represent important causes of clinically meaningful drug interactions. PMID:21985665
Determining the Average Age of School Plant Building Space.
ERIC Educational Resources Information Center
Uerling, Donald F.
1984-01-01
Presents a method for calculating the age of the space in a specific building inventory, and suggests some practical applications. A fourfold procedure is provided for finding the average age of total building space. (TE)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Blumenhagen, Ralph; /Munich, Max Planck Inst.; Grimm, Thomas W.
2010-08-26
We construct global F-theory GUT models on del Pezzo surfaces in compact Calabi-Yau fourfolds realized as complete intersections of two hypersurface constraints. The intersections of the GUT brane and the flavour branes as well as the gauge flux are described by the spectral cover construction. We consider a split S[U(4) x U(1){sub X}] spectral cover, which allows for the phenomenologically relevant Yukawa couplings and GUT breaking to the MSSM via hypercharge flux while preventing dimension-4 proton decay. General expressions for the massless spectrum, consistency conditions and a new method for the computation of curvature-induced tadpoles are presented. We also providemore » a geometric toolkit for further model searches in the framework of toric geometry. Finally, an explicit global model with three chiral generations and all required Yukawa couplings is defined on a Calabi-Yau fourfold which is fibered over the del Pezzo transition of the Fano threefold P{sup 4}.« less
Large-area ordered Ge-Si compound quantum dot molecules on dot-patterned Si (001) substrates
NASA Astrophysics Data System (ADS)
Lei, Hui; Zhou, Tong; Wang, Shuguang; Fan, Yongliang; Zhong, Zhenyang
2014-08-01
We report on the formation of large-area ordered Ge-Si compound quantum dot molecules (CQDMs) in a combination of nanosphere lithography and self-assembly. Truncated-pyramid-like Si dots with {11n} facets are readily formed, which are spatially ordered in a large area with controlled period and size. Each Si dot induces four self-assembled Ge-rich dots at its base edges that can be fourfold symmetric along <110> directions. A model based on surface chemical potential accounts well for these phenomena. Our results disclose the critical effect of surface curvature on the diffusion and the aggregation of Ge adatoms and shed new light on the unique features and the inherent mechanism of self-assembled QDs on patterned substrates. Such a configuration of one Si QD surrounded by fourfold symmetric Ge-rich QDs can be seen as a CQDM with unique features, which will have potential applications in novel devices.
Caselli, Desiree; Cesaro, Simone; Fagioli, Franca; Carraro, Francesca; Ziino, Ottavio; Zanazzo, Giulio; Meazza, Cristina; Colombini, Antonella; Castagnola, Elio
2016-02-01
Few data are available on the incidence of carbapenemase-producing Enterobacteriaceae (CPE) infection or colonization in children receiving anticancer chemotherapy. We performed a nationwide survey among centers participating in the pediatric hematology-oncology cooperative study group (Associazione Italiana Ematologia Oncologia Pediatrica, AIEOP). During a 2-year observation period, we observed a threefold increase in the colonization rate, and a fourfold increase of bloodstream infection episodes, caused by CPE, with a 90-day mortality of 14%. This first nationwide Italian pediatric survey shows that the circulation of CPE strains in the pediatric hematology-oncology environment is increasing. Given the mortality rate, which is higher than for other bacterial strains, specific monitoring should be applied and the results should have implications for health-care practice in pediatric hematology-oncology.
Effects of pine pollen supplementation in an onion diet on Frankliniella fusca reproduction.
Angelella, G M; Riley, D G
2010-04-01
A micro-cage bioassay was developed to test the effect of slash pine pollen (Pinus elliottii Engelm.) supplementation to a whole onion plant (Allium cepa L. variety Pegasus) diet on thrips (Thysanoptera: Thripidae) reproductive parameters. Frankliniella fusca (Hinds) females were placed on two to three-leaf stage onion seedling under a treatment of either slash pine (Pinus elliottii Engelm.) pollen dusting (a pollen supplement) or no pollen treatment. Adult survival, net oviposition, and offspring produced over a series of ten 2-d intervals were recorded. From these values, l(x), l(x)m(x), and R(0) values were constructed. A trimodal distribution of oviposition was observed with the pollen supplement. Increased oviposition rates led to higher female offspring production per female and to a four-fold increase in F. fusca net reproduction on pollen-treated onions.
Shishkov, A V; Ksenofontov, A L; Bogacheva, E N; Kordyukova, L V; Badun, G A; Alekseevsky, A V; Tsetlin, V I; Baratova, L A
2002-05-15
The topography of bacteriorhodopsin (bR) in situ was earlier studied by using the tritium bombardment approach [Eur. J. Biochem. 178 (1988) 123]. Now, having the X-ray crystallography data of bR at atom resolution [Proc. Natl. Acad. Sci. 95 (1998) 11673], we estimated the influence of membrane environment (lipid and protein) on tritium incorporation into amino acid residues forming transmembrane helices. We have determined the tritium flux attenuation coefficients for residues 10-29 of helix A. They turned out to be low (0.04+/-0.02 A(-1)) for residues adjacent to the lipid matrix, and almost fourfold higher (0.15+/-0.05 A(-1)) for those oriented to the neighboring transmembrane helices. We believe that tritium incorporation data could help modeling transmembrane segment arrangement in the membrane.
Partially Acetylated Sugarcane Bagasse For Wicking Oil From Contaminated Wetlands
Sugarcane bagasse was partially acetylated to enhance its oil-wicking ability in saturated environments while holding moisture for hydrocarbon biodegradation. The water sorption capacity of raw bagasse was reduced fourfold after treatment, which indicated considerably increased ...
Higher Incidence of Hypospadias in Monochorionic Twins.
Visser, Remco; Burger, Nienke C M; van Zwet, Erik W; Hilhorst-Hofstee, Yvonne; Haak, Monique C; van den Hoek, Joop; Oepkes, Dick; Lopriore, Enrico
2015-10-01
Hypospadias is associated with twinning. The incidence of hypospadias in monochorionic and dichorionic male twins is, however, yet to be determined. All medical records of monochorionic and dichorionic twins admitted to our neonatal nursery between January 2004 and August 2013 were reviewed for the presence of hypospadias. A total of 350 monochorionic and 303 dichorionic male twins were included in the study. The incidence of hypospadias in monochorionic and dichorionic groups was 4% (14/350) and 1% (3/303) (p = .016) respectively. In 11 of the 15 twin couples, hypospadias occurred in the twin with the lowest birth weight. The rate of hypospadias in twin infants small-for-gestational-age group was 10% (6/60) compared with 2% (11/593) in the appropriate-for-gestational-age group (p = .002). In a multivariate analysis, both monochorionicity and small-for-gestational-age were independently associated with hypospadias, odds ratio 4.1 (95% confidence interval (CI): 1.1-14.7) and 6.1 (95% CI: 2.2-17.2) respectively. The incidence of hypospadias is four-fold higher in monochorionic twins compared with dichorionic twins. Hypospadias is also independently associated with small-for-gestational-age.
Biochemical indicators of root damage in rice (Oryza sativa) genotypes under zinc deficiency stress.
Lee, Jae-Sung; Wissuwa, Matthias; Zamora, Oscar B; Ismail, Abdelbagi M
2017-11-01
Zn deficiency is one of the major soil constraints currently limiting rice production. Although recent studies demonstrated that higher antioxidant activity in leaf tissue effectively protects against Zn deficiency stress, little is known about whether similar tolerance mechanisms operate in root tissue. In this study we explored root-specific responses of different rice genotypes to Zn deficiency. Root solute leakage and biomass reduction, antioxidant activity, and metabolic changes were measured using plants grown in Zn-deficient soil and hydroponics. Solute leakage from roots was higher in sensitive genotypes and linked to membrane damage caused by Zn deficiency-induced oxidative stress. However, total root antioxidant activity was four-fold lower than in leaves and did not differ between sensitive and tolerant genotypes. Root metabolite analysis using gas chromatography-mass spectrometry and high performance liquid chromatography indicated that Zn deficiency triggered the accumulation of glycerol-3-phosphate and acetate in sensitive genotypes, while less or no accumulation was seen in tolerant genotypes. We suggest that these metabolites may serve as biochemical indicators of root damage under Zn deficiency.
An ultra-thin compact polarization-independent hexa-band metamaterial absorber
NASA Astrophysics Data System (ADS)
Munaga, Praneeth; Bhattacharyya, Somak; Ghosh, Saptarshi; Srivastava, Kumar Vaibhav
2018-04-01
In this paper, an ultra-thin compact hexa-band metamaterial absorber has been presented using single layer of dielectric. The proposed design is polarization independent in nature owing to its fourfold symmetry and exhibits high angular stability up to 60° angles of incidences for both TE and TM polarizations. The structure is ultrathin in nature with 2 mm thickness, which corresponds to λ/11.4 ( λ is the operating wavelength with respect to the highest frequency of absorption). Six distinct absorption frequencies are obtained from the design, which can be distributed among three regions, namely lower band, middle band and higher band; each region consists of two closely spaced frequencies. Thereafter, the dimensions of the proposed structure are adjusted in such a way that bandwidth enhancement occurs at each region separately. Simultaneous bandwidth enhancements at middle and higher bands have also been achieved by proper optimization of the geometrical parameters. The structure with simultaneous bandwidth enhancements at X- and Ku-bands is later fabricated and the experimental absorptivity response is in agreement with the simulated one.
Docherty, D.E.; Samuel, M.D.; Egstad, K.F.; Griffin, K.M.; Nolden, C.A.; Karwal, L.; Ip, Hon S.
2009-01-01
After the 2001 occurrence of West Nile virus (WNV) in Wisconsin (WI), we collected sera, during 2003-2006, from south-central WI mesopredators. We tested these sera to determine WNV antibody prevalence and geometric mean antibody titer (GMAT). Four-fold higher antibody prevalence and 2-fold higher GMAT in 2003-2004 indicated greater exposure of mesopredators to WNV during the apparent epizootic phase. The period 2005-2006 was likely the enzootic phase because WNV antibody prevalence fell to a level similar to other flaviviruses. Our results suggest that, in mesopredators, vector-borne transmission is the primary route of infection and WNV antibodies persist for < 1 year. Mesopredators may be sensitive indicators of West Nile virus spill-over into humans and horses. Mesopredator sero-surveys may complement dead crow surveillance by providing additional data for the timing of public health interventions. Research is needed to clarify the dynamics of WNV infection in these mammals and their role as potential WNV amplifiers. Copyright ?? 2009 by The American Society of Tropical Medicine and Hygiene.
Obliquely Incident Solitary Wave onto a Vertical Wall
NASA Astrophysics Data System (ADS)
Yeh, Harry
2012-10-01
When a solitary wave impinges obliquely onto a reflective vertical wall, it can take the formation of a Mach reflection (a geometrically similar reflection from acoustics). The mathematical theory predicts that the wave at the reflection can amplify not twice, but as high as four times the incident wave amplitude. Nevertheless, this theoretical four-fold amplification has not been verified by numerical or laboratory experiments. We discuss the discrepancies between the theory and the experiments; then, improve the theory with higher-order corrections. The modified theory results in substantial improvement and is now in good agreement with the numerical as well as our laboratory results. Our laboratory experiments indicate that the wave amplitude along the reflective wall can reach 0.91 times the quiescent water depth, which is higher than the maximum of a freely propagating solitary wave. Hence, this maximum runup 0.91 h would be possible even if the amplitude of the incident solitary wave were as small as 0.24 h. This wave behavior could provide an explanation for local variability of tsunami runup as well as for sneaker waves.
Lunar Surface Stirling Power Systems Using Isotope Heat Sources
NASA Technical Reports Server (NTRS)
Schmitz, Paul C.; Penswick, L. Barry; Shaltens, Richard K.
2010-01-01
For many years, NASA has used the decay of plutonium-238 (Pu-238) (in the form of the General Purpose Heat Source (GPHS)) as a heat source for Radioisotope Thermoelectric Generators (RTGs), which have provided electrical power for many NASA missions. While RTGs have an impressive reliability record for the missions in which they have been used, their relatively low thermal to electric conversion efficiency and the scarcity of plutonium-238 (Pu-238) has led NASA to consider other power conversion technologies. NASA is considering returning both robotic and human missions to the lunar surface and, because of the long lunar nights (14.75 Earth days), isotope power systems are an attractive candidate to generate electrical power. NASA is currently developing the Advanced Stirling Radioisotope Generator (ASRG) as a candidate higher efficiency power system that produces greater than 160 W with two GPHS modules at the beginning of life (BOL) (32% efficiency). The ASRG uses the same Pu-238 GPHS modules, which are used in RTG, but by coupling them to a Stirling convertor provides a four-fold reduction in the number of GPHS modules. This study considers the use of americium-241 (Am-241) as a substitute for the Pu-238 in Stirling- convertor-based Radioisotope Power Systems (RPS) for power levels from tens of watts to 5 kWe. The Am-241 is used as a substitute for the Pu-238 in GPHS modules. Depending on power level, different Stirling heat input and removal systems are modeled. It was found that substituting Am-241 GPHS modules into the ASRG reduces power output by about one-fifth while maintaining approximately the same system mass. In order to obtain the nominal 160 W of electrical output of the Pu-238 ASRG requires 10 Am-241 GPHS modules. Higher power systems require changing from conductive coupling heat input and removal from the Stirling convertor to either pumped loops or heat pipes. Liquid metal pumped loops are considered as the primary heat transportation on the hot end and water pumped loop/heat pipe radiator is considered for the heat rejection side for power levels above 1 kWe.
Lis, Dana M; Fell, James W; Ahuja, Kiran D K; Kitic, Cecilia M; Stellingwerff, Trent
2016-01-01
Recent explosion in the prevalence of gluten-free athletes, exacerbated by unsubstantiated commercial health claims, has led to some professional athletes touting gluten-free diet as the secret to their success. Forty-one percent of athletes report adhering to a gluten-free diet (GFD), which is four-fold higher than the population-based clinical requirements. Many nonceliac athletes believe that gluten avoidance improves gastrointestinal well-being, reduces inflammation, and provides an ergogenic edge, despite the fact that limited data yet exist to support any of these benefits. There are several plausible associations between endurance-based exercise and gastrointestinal permeability whereby a GFD may be beneficial. However, the implications of confounding factors, including the risks of unnecessary dietary restriction, financial burden, food availability, psychosocial implications, alterations in short-chain carbohydrates (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols), and other wheat constituents emphasize the need for further evaluation.
Emerging superconductivity hidden beneath charge-transfer insulators
Krockenberger, Yoshiharu; Irie, Hiroshi; Matsumoto, Osamu; Yamagami, Keitaro; Mitsuhashi, Masaya; Tsukada, Akio; Naito, Michio; Yamamoto, Hideki
2013-01-01
In many of today's most interesting materials, strong interactions prevail upon the magnetic moments, the electrons, and the crystal lattice, forming strong links between these different aspects of the system. Particularly, in two-dimensional cuprates, where copper is either five- or six-fold coordinated, superconductivity is commonly induced by chemical doping which is deemed to be mandatory by destruction of long-range antiferromagnetic order of 3d9 Cu2+ moments. Here we show that superconductivity can be induced in Pr2CuO4, where copper is four-fold coordinated. We induced this novel quantum state of Pr2CuO4 by realizing pristine square-planar coordinated copper in the copper-oxygen planes, thus, resulting in critical superconducting temperatures even higher than by chemical doping. Our results demonstrate new degrees of freedom, i.e., coordination of copper, for the manipulation of magnetic and superconducting order parameters in quantum materials. PMID:23887134
Angerami, Rodrigo N; Resende, Mariângela R; Feltrin, Adriana F C; Katz, Gizelda; Nascimento, Elvira M; Stucchi, Raquel S B; Silva, Luiz J
2006-10-01
This case series study is based on a retrospective review of medical records and case notification files of patients admitted to The Hospital das Clínicas da UNICAMP from 1985 to 2003 with a confirmed diagnosis of BSF either by fourfold rise in indirect immunofluorescence assay (IFA) titers of IgG antibodies reactive with R. rickettsii or isolation of R. rickettsii from blood or skin specimens. A median lethality of 41.9 % was observed between 1985 and 2004. The case-fatality ratio of 30 % in our study, lower than the overall São Paulo state ratio, could be explained by a higher index of suspicion and a larger experience in our hospital, a regional referral center for BSF. The presence of the classical triad of fever, rash, and headache as described in RMSF was observed in fever than half (35.2%) of our patients.
Targeted gene disruption in Koji mold Aspergillus oryzae.
Maruyama, Jun-Ichi; Kitamoto, Katsuhiko
2011-01-01
Filamentous fungi have received attentions as hosts for heterologous protein production because of their high secretion capability and eukaryotic post-translational modifications. One of the safest hosts for heterologous protein production is Koji mold Aspergillus oryzae since it has been used in the production of Japanese fermented foods for over 1,000 years. The production levels of proteins from higher eukaryotes are much lower than those of homologous (fungal) proteins. Bottlenecks in the heterologous protein production are suggested to be proteolytic degradation of the produced protein in the medium and the secretory pathway. For construction of excellent host strains, many genes causing the bottlenecks should be disrupted rapidly and efficiently. We developed a marker recycling system with the highly efficient gene-targeting background in A. oryzae. By employing this technique, we performed multiple gene disruption of the ten protease genes. The decuple protease gene disruptant showed fourfold production level of a heterologous protein compared with the wild-type strain.
NASA Astrophysics Data System (ADS)
Li, Cang; Wang, Ge; Evans, David G.; Duan, Xue
2004-12-01
Reaction of an aqueous slurry of an Mg 2Al-NO 3 layered double hydroxide with a four-fold excess of Na[Eu(EDTA)] gives a material which analyses for Mg 0.68Al 0.32(OH) 2[Eu(EDTA)] 0.10(CO 3) 0.11·0.66H 2O. The interlayer spacing of the material is 13.8 Å, corresponding to a gallery height of 9.0 Å, which accords with the maximal dimensions (9-10 Å) of the anion in metal-EDTA complex salts as determined by single crystal X-ray diffraction. Geometrical considerations show that the charge density on the layered double hydroxide layers is too high to be balanced by intercalation of [Eu(EDTA)] - alone, necessitating the co-intercalation of carbonate ions which have a much higher charge density.
NASA Astrophysics Data System (ADS)
Andrew Mackay, J.; Chen, Mingnan; McDaniel, Jonathan R.; Liu, Wenge; Simnick, Andrew J.; Chilkoti, Ashutosh
2009-12-01
New strategies to self-assemble biocompatible materials into nanoscale, drug-loaded packages with improved therapeutic efficacy are needed for nanomedicine. To address this need, we developed artificial recombinant chimeric polypeptides (CPs) that spontaneously self-assemble into sub-100-nm-sized, near-monodisperse nanoparticles on conjugation of diverse hydrophobic molecules, including chemotherapeutics. These CPs consist of a biodegradable polypeptide that is attached to a short Cys-rich segment. Covalent modification of the Cys residues with a structurally diverse set of hydrophobic small molecules, including chemotherapeutics, leads to spontaneous formation of nanoparticles over a range of CP compositions and molecular weights. When used to deliver chemotherapeutics to a murine cancer model, CP nanoparticles have a fourfold higher maximum tolerated dose than free drug, and induce nearly complete tumour regression after a single dose. This simple strategy can promote co-assembly of drugs, imaging agents and targeting moieties into multifunctional nanomedicines.
Theil, Elizabeth C; Turano, Paola; Ghini, Veronica; Allegrozzi, Marco; Bernacchioni, Caterina
2014-06-01
Integrated ferritin protein cage function is the reversible synthesis of protein-caged, solid Fe2O3·H2O minerals from Fe(2+) for metabolic iron concentrates and oxidant protection; biomineral order differs in different ferritin proteins. The conserved 432 geometric symmetry of ferritin protein cages parallels the subunit dimer, trimer, and tetramer interfaces, and coincides with function at several cage axes. Multiple subdomains distributed in the self-assembling ferritin nanocages have functional relationships to cage symmetry such as Fe(2+) transport though ion channels (threefold symmetry), biomineral nucleation/order (fourfold symmetry), and mineral dissolution (threefold symmetry) studied in ferritin variants. On the basis of the effects of natural or synthetic subunit dimer cross-links, cage subunit dimers (twofold symmetry) influence iron oxidation and mineral dissolution. 2Fe(2+)/O2 catalysis in ferritin occurs in single subunits, but with cooperativity (n = 3) that is possibly related to the structure/function of the ion channels, which are constructed from segments of three subunits. Here, we study 2Fe(2+) + O2 protein catalysis (diferric peroxo formation) and dissolution of ferritin Fe2O3·H2O biominerals in variants with altered subunit interfaces for trimers (ion channels), E130I, and external dimer surfaces (E88A) as controls, and altered tetramer subunit interfaces (L165I and H169F). The results extend observations on the functional importance of structure at ferritin protein twofold and threefold cage axes to show function at ferritin fourfold cage axes. Here, conserved amino acids facilitate dissolution of ferritin-protein-caged iron biominerals. Biological and nanotechnological uses of ferritin protein cage fourfold symmetry and solid-state mineral properties remain largely unexplored.
Martinez, Bridget; Soñanez-Organis, José G.; Vázquez-Medina, José Pablo; Viscarra, Jose A.; MacKenzie, Duncan S.; Crocker, Daniel E.; Ortiz, Rudy M.
2013-01-01
SUMMARY Food deprivation in mammals is typically associated with reduced thyroid hormone (TH) concentrations and deiodinase content and activity to suppress metabolism. However, in prolonged-fasted, metabolically active elephant seal pups, TH levels are maintained, if not elevated. The functional relevance of this apparent paradox is unknown and demonstrates variability in the regulation of TH levels, metabolism and function in food-deprived mammals. To address our hypothesis that cellular TH-mediated activity is upregulated with fasting duration, we quantified the mRNA expression and protein content of adipose and muscle deiodinase type I (DI1) and type II (DI2), and TH receptor beta-1 (THrβ-1) after 1, 3 and 7 weeks of fasting in northern elephant seal pups (N=5–7 per week). Fasting did not decrease the concentrations of plasma thyroid stimulating hormone, total triiodothyronine (tT3), free T3, total thyroxine (tT4) or free T4, suggesting that the hypothalamic–pituitary–thyroid axis is not suppressed, but rather maintained during fasting. Mean mRNA expression of adipose DI1 and DI2 increased threefold and fourfold, respectively, and 20- and 30-fold, respectively, in muscle. With the exception of adipose DI1, protein expression of adipose DI2 and muscle DI1 and DI2 increased twofold to fourfold. Fasting also increased adipose (fivefold) and muscle (fourfold) THrβ-1 mRNA expression, suggesting that the mechanisms mediating cellular TH activity are upregulated with prolonged fasting. The data demonstrate a unique, atypical mechanism of TH activity and regulation in mammals adapted to prolonged food deprivation in which the potential responsiveness of peripheral tissues and cellular TH activity are increased, which may contribute to their lipid-based metabolism. PMID:24307712
Optimisation modelling to assess cost of dietary improvement in remote Aboriginal Australia.
Brimblecombe, Julie; Ferguson, Megan; Liberato, Selma C; O'Dea, Kerin; Riley, Malcolm
2013-01-01
The cost and dietary choices required to fulfil nutrient recommendations defined nationally, need investigation, particularly for disadvantaged populations. We used optimisation modelling to examine the dietary change required to achieve nutrient requirements at minimum cost for an Aboriginal population in remote Australia, using where possible minimally-processed whole foods. A twelve month cross-section of population-level purchased food, food price and nutrient content data was used as the baseline. Relative amounts from 34 food group categories were varied to achieve specific energy and nutrient density goals at minimum cost while meeting model constraints intended to minimise deviation from the purchased diet. Simultaneous achievement of all nutrient goals was not feasible. The two most successful models (A & B) met all nutrient targets except sodium (146.2% and 148.9% of the respective target) and saturated fat (12.0% and 11.7% of energy). Model A was achieved with 3.2% lower cost than the baseline diet (which cost approximately AUD$13.01/person/day) and Model B at 7.8% lower cost but with a reduction in energy of 4.4%. Both models required very large reductions in sugar sweetened beverages (-90%) and refined cereals (-90%) and an approximate four-fold increase in vegetables, fruit, dairy foods, eggs, fish and seafood, and wholegrain cereals. This modelling approach suggested population level dietary recommendations at minimal cost based on the baseline purchased diet. Large shifts in diet in remote Aboriginal Australian populations are needed to achieve national nutrient targets. The modeling approach used was not able to meet all nutrient targets at less than current food expenditure.
A Monte Carlo exploration of threefold base geometries for 4d F-theory vacua
NASA Astrophysics Data System (ADS)
Taylor, Washington; Wang, Yi-Nan
2016-01-01
We use Monte Carlo methods to explore the set of toric threefold bases that support elliptic Calabi-Yau fourfolds for F-theory compactifications to four dimensions, and study the distribution of geometrically non-Higgsable gauge groups, matter, and quiver structure. We estimate the number of distinct threefold bases in the connected set studied to be ˜ 1048. The distribution of bases peaks around h 1,1 ˜ 82. All bases encountered after "thermalization" have some geometric non-Higgsable structure. We find that the number of non-Higgsable gauge group factors grows roughly linearly in h 1,1 of the threefold base. Typical bases have ˜ 6 isolated gauge factors as well as several larger connected clusters of gauge factors with jointly charged matter. Approximately 76% of the bases sampled contain connected two-factor gauge group products of the form SU(3) × SU(2), which may act as the non-Abelian part of the standard model gauge group. SU(3) × SU(2) is the third most common connected two-factor product group, following SU(2) × SU(2) and G 2 × SU(2), which arise more frequently.
Vogl, Claus; Clemente, Florian
2012-05-01
We analyze a decoupled Moran model with haploid population size N, a biallelic locus under mutation and drift with scaled forward and backward mutation rates θ(1)=μ(1)N and θ(0)=μ(0)N, and directional selection with scaled strength γ=sN. With small scaled mutation rates θ(0) and θ(1), which is appropriate for single nucleotide polymorphism data in highly recombining regions, we derive a simple approximate equilibrium distribution for polymorphic alleles with a constant of proportionality. We also put forth an even simpler model, where all mutations originate from monomorphic states. Using this model we derive the sojourn times, conditional on the ancestral and fixed allele, and under equilibrium the distributions of fixed and polymorphic alleles and fixation rates. Furthermore, we also derive the distribution of small samples in the diffusion limit and provide convenient recurrence relations for calculating this distribution. This enables us to give formulas analogous to the Ewens-Watterson estimator of θ for biased mutation rates and selection. We apply this theory to a polymorphism dataset of fourfold degenerate sites in Drosophila melanogaster. Copyright © 2012 Elsevier Inc. All rights reserved.
Casein Kinase 2 Reverses Tail-Independent Inactivation of Kinesin-1
NASA Astrophysics Data System (ADS)
Xu, Jing
2013-03-01
Kinesin-1 is a plus-end microtubule-based motor, and defects in kinesin-based transport are linked to diseases including neurodegeneration. Kinesin can auto-inhibit via a head-tail interaction, but is believed to be active otherwise. Here we report a tail-independent inactivation of kinesin, reversible by the disease-relevant signalling protein, casein kinase 2 (CK2). The majority of initially active kinesin (native or tail-less) loses its ability to interact with microtubules in vitro, and CK2 reverses this inactivation (approximately fourfold) without altering kinesin's single motor properties. This activation pathway does not require motor phosphorylation, and is independent of head-tail auto-inhibition. In cultured mammalian cells, reducing CK2 expression, but not its kinase activity, decreases the force required to stall lipid droplet transport, consistent with a decreased number of active kinesin motors. Our results (Nat. Commun., 3:754, 2012) provide the first direct evidence of a protein kinase upregulating kinesin-based transport, and suggest a novel pathway for regulating the activity of cargo-bound kinesin. Work supported by NIGMS grants GM64624 to SPG, GM74830-06A1 to LH, GM76516 to LB, NS048501 to SJK, and AHA grant 825278F to JX.
VeA of Aspergillus niger increases spore dispersing capacity by impacting conidiophore architecture.
Wang, Fengfeng; Dijksterhuis, Jan; Wyatt, Timon; Wösten, Han A B; Bleichrodt, Robert-Jan
2015-01-01
Aspergillus species are highly abundant fungi worldwide. Their conidia are among the most dominant fungal spores in the air. Conidia are formed in chains on the vesicle of the asexual reproductive structure called the conidiophore. Here, it is shown that the velvet protein VeA of Aspergillus niger maximizes the diameter of the vesicle and the spore chain length. The length and width of the conidiophore stalk and vesicle were reduced nearly twofold in a ΔveA strain. The latter implies a fourfold reduced surface area to develop chains of spores. Over and above this, the conidial chain length was approximately fivefold reduced. The calculated 20-fold reduction in formation of conidia by ΔveA fits the 8- to 17-fold decrease in counted spore numbers. Notably, morphology of the ΔveA conidiophores of A. niger was very similar to that of wild-type Aspergillus sydowii. This suggests that VeA is key in conidiophore architecture diversity in the fungal kingdom. The finding that biomass formation of the A. niger ΔveA strain was reduced twofold shows that VeA not only impacts dispersion capacity but also colonization capacity of A. niger.
Detection of glucose oxidation products in chilled fresh beef undergoing spoilage.
Farber, J M; Idziak, E S
1982-01-01
The fate of nutrients during storage of longissimus dorsi muscle at 4 degrees C was examined. Glucose concentrations in meat were shown to decrease concomitantly with an approximately fourfold increase in the activity of glucose dehydrogenase. Gluconate concentrations in meat were determined by an enzyme assay and shown to increase from 2.1 to 40.6 microgram/g upon storage of the meat from day 0 to day 6. At day 12, gluconate concentrations had decreased to 5.8 microgram/g. Dark firm dry meat, which contains little or no glucose, did not exhibit the same rise and fall in gluconate concentration. Thin-layer chromatographic analysis confirmed the presence of 2-ketogluconate in 6- and 12-day-old longissimus dorsi muscle that had been stored at 4 degrees C. Gluconate concentrations in irradiated sterile meat inoculated with Pseudomonas fluorescens increased from 4.2 to 77.8 microgram/g during the first 6 days of storage at 4 degrees C. Therefore, glucose in meat stored at 4 degrees C appeared to be converted to gluconate, 2-ketogluconate, or both extracellularly by one of the main meat spoilage organisms, most likely the pseudomonads. PMID:7137997
Second messenger production in avian medullary nephron segments in response to peptide hormones.
Goldstein, D L; Reddy, V; Plaga, K
1999-03-01
We examined the sites of peptide hormone activation within medullary nephron segments of the house sparrow (Passer domesticus) kidney by measuring rates of hormone-induced generation of cyclic nucleotide second messenger. Thin descending limbs, thick ascending limbs, and collecting ducts had baseline activity of adenylyl cyclase that resulted in cAMP accumulation of 207 +/- 56, 147 +/- 31, and 151 +/- 41 fmol. mm-1. 30 min-1, respectively. In all segments, this activity increased 10- to 20-fold in response to forskolin. Activity of adenylyl cyclase in the thin descending limb was stimulated approximately twofold by parathyroid hormone (PTH) but not by any of the other hormones tested [arginine vasotocin (AVT), glucagon, atrial natriuretic peptide (ANP), or isoproterenol, each at 10(-6) M]. Thick ascending limb was stimulated two- to threefold by both AVT and PTH; however, glucagon and isoproterenol had no effect, and ANP stimulated neither cAMP nor cGMP accumulation. Adenylyl cyclase activity in the collecting duct was stimulated fourfold by AVT but not by the other hormones; likewise, ANP did not stimulate cGMP accumulation in this segment. These data support a tubular action of AVT and PTH in the avian renal medulla.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yano, K.; Morimasa, K.; Asano, T.
1985-04-01
Characterization of the cells responsible for spontaneous DNA synthesis and/or IgG secretion in systemic lupus erythematosus (SLE) was undertaken by fractionation of the peripheral blood mononuclear cells (PBM). Each fraction was analyzed for its capacity to incorporate (/sup 3/H)thymidine ((/sup 3/H)TdR) and secrete IgG without mitogen. The non-E rosette-forming cell (non-ERRC) fraction, which consisted of the surface immunoglobulin-positive (sIg(+)) cells and null cells, revealed a markedly increased spontaneous DNA synthesis (620.0 +/- 586.9 cpm) during the first hour of culture and an elevated spontaneous IgG secretion (8639 +/- 2630 ng/ml) during 9 days of culture. Of particular interest was themore » finding that both increased responses were conducted by the null cells; the null cell population had approximately a fourfold relative increase of (/sup 3/H)TdR incorporation and a 60-fold relative increase of IgG secretion compared with the sIg(+) cell population. These results suggest that SLE patients have a small population of preactivated B-cell lineage cells, which lack sIg or have a very low density of sIg.« less
A Monte Carlo exploration of threefold base geometries for 4d F-theory vacua
Taylor, Washington; Wang, Yi-Nan
2016-01-22
Here, we use Monte Carlo methods to explore the set of toric threefold bases that support elliptic Calabi-Yau fourfolds for F-theory compactifications to four dimensions, and study the distribution of geometrically non-Higgsable gauge groups, matter, and quiver structure. We estimate the number of distinct threefold bases in the connected set studied to be ~ 10 48. Moreover, the distribution of bases peaks around h 1,1 ~ 82. All bases encountered after "thermalization" have some geometric non-Higgsable structure. We also find that the number of non-Higgsable gauge group factors grows roughly linearly in h 1,1 of the threefold base. Typical basesmore » have ~ 6 isolated gauge factors as well as several larger connected clusters of gauge factors with jointly charged matter. Approximately 76% of the bases sampled contain connected two-factor gauge group products of the form SU(3) x SU(2), which may act as the non-Abelian part of the standard model gauge group. SU(3) x SU(2) is the third most common connected two-factor product group, following SU(2) x SU(2) and G2 x SU(2), which arise more frequently.« less
The relationship of fibroblast translocations to cell morphology and stress fibre density.
Lewis, L; Verna, J M; Levinstone, D; Sher, S; Marek, L; Bell, E
1982-02-01
Translocation of human fibroblasts in culture was studied using techniques of time-lapse cinemicrography, indirect immunofluorescence, and computer analysis. An inverse relationship between the velocity of cells during the last hour of life and the density of stress fibers seen by immune staining was demonstrated. Translocating cells generally assumed one of two interconvertible morphologies: a triangular tailed shape or tailed fibroblast (TF), and a tailless form that resembled a half-moon, which we call a half-moon fibroblast (HMF). The tail of TFs formed only on regions of substrate that had been previously traversed by cells. The half-moon morphology developed either on previously used or on virgin substrate. Cells adopted the HMF rather than the TF morphology with a four-fold greater frequency. HMFs translocated slightly faster than TFs. The foregoing observation suggest that the fibroblast tail is not an organelle essential for translocation. Since our technique allowed us to distinguish between cells which were cycling and those which had left cycle, we compared their velocities and found them to be similar. Also the average velocities of cells of different population-doubling levels (10th, 30th, 40th) were approximately equal.
What Went Wrong, If Anything, Since Copernicus?
ERIC Educational Resources Information Center
Boulding, Kenneth E.
1974-01-01
Discusses the history of the inequality of world incomes on the basis of a four-fold classification of societies. Indicates that a zero-growth, industrial, ontological, non-destructive society is predictable in the future due to man's expansion from isolated ecosystems into one single world. (CC)
Vortex with fourfold defect lines in a simple model of self-propelled particles
NASA Astrophysics Data System (ADS)
Seyed-Allaei, Hamid; Ejtehadi, Mohammad Reza
2016-03-01
We study the formation of a vortex with fourfold symmetry in a minimal model of self-propelled particles, confined inside a squared box, using computer simulations and also theoretical analysis. In addition to the vortex pattern, we observe five other regimes in the system: a homogeneous gaseous phase, band structures, moving clumps, moving clusters, and vibrating rings. All six regimes emerge from controlling the strength of noise and from the contribution of repulsion and alignment interactions. We study the shape of the vortex and its symmetry in detail. The pattern shows exponential defect lines where incoming and outgoing flows of particles collide. We show that alignment and repulsion interactions between particles are necessary to form such patterns. We derive hydrodynamical equations with an introduction of the "small deviation" technique to describe the vortex phase. The method is applicable to other systems as well. Finally, we compare the theory with the results of both computer simulations and an experiment using Quincke rotors. A good agreement between the three is observed.
Mehrotra, Ateev; Lave, Judith R.
2013-01-01
Retail clinics have rapidly become a fixture of the United States health care delivery landscape. In our analyses of trends in retail clinic utilization, we find there has been a four-fold increase in retail clinic visits between 2007 to 2009, with an estimated 5.9 million retail clinic visits in 2009. Compared with the period from 2000–2006, in the period from 2007–9 retail clinic patients are now more likely to be greater than 65 years old (18.9 percent vs. 7.8 percent) and preventive care, in particular the influenza vaccine, has become a larger component of their care (47.5 percent vs. 21.8 percent of visits). Across all retail clinic visits, 44.4 percent are on the weekend or on the weekdays when physician offices are typically closed. Retail clinics appear to be meeting a need for convenient care, in particular during times when physician offices are not open. PMID:22895454
Topological invariants and fibration structure of complete intersection Calabi-Yau four-folds
NASA Astrophysics Data System (ADS)
Gray, James; Haupt, Alexander S.; Lukas, Andre
2014-09-01
We investigate the mathematical properties of the class of Calabi-Yau four-folds recently found in ref. [1]. This class consists of 921,497 configuration matrices which correspond to manifolds that are described as complete intersections in products of projective spaces. For each manifold in the list, we compute the full Hodge diamond as well as additional topological invariants such as Chern classes and intersection numbers. Using this data, we conclude that there are at least 36,779 topologically distinct manifolds in our list. We also study the fibration structure of these manifolds and find that 99.95 percent can be described as elliptic fibrations. In total, we find 50,114,908 elliptic fibrations, demonstrating the multitude of ways in which many manifolds are fibered. A sub-class of 26,088,498 fibrations satisfy necessary conditions for admitting sections. The complete data set can be downloaded from http://www-thphys.physics.ox.ac.uk/projects/CalabiYau/Cicy4folds/index.html.
Novel DNPH-based method for determination of protein carbonylation in muscle and meat.
Soglia, Francesca; Petracci, Massimiliano; Ertbjerg, Per
2016-04-15
Protein oxidation is considered an ongoing deteriorative process during storage of fresh and processed meat. Carbonyl compounds have traditionally been detected spectrophotometrically after derivatization with 2,4-dinitrophenylhydrazine (DNPH) to form protein-bound hydrazones with absorbance at 370 nm. Here we describe a novel DNPH-based method to quantify protein carbonylation in muscle and meat. The additional steps of the novel method aimed at increasing the protein solubility and inducing protein unfolding before labeling with DNPH. Compared to the traditional method, the new procedure reflected an increased protein carbonylation level measuring overall two to fourfold more carbonyls in muscles from different species as well as in soluble, salt-soluble and insoluble protein fractions. The study suggested that protein unfolding is a more important phenomenon than solubilization for increased DNPH labeling. The novel method resulted in three to fourfold larger carbonyl content determined in chicken, pork and beef (2.8, 3.6 and 3.1 nmol/mg of protein, respectively). Copyright © 2015 Elsevier Ltd. All rights reserved.
Algebraic cycles and local anomalies in F-theory
NASA Astrophysics Data System (ADS)
Bies, Martin; Mayrhofer, Christoph; Weigand, Timo
2017-11-01
We introduce a set of identities in the cohomology ring of elliptic fibrations which are equivalent to the cancellation of gauge and mixed gauge-gravitational anomalies in F-theory compactifications to four and six dimensions. The identities consist in (co)homological relations between complex codimension-two cycles. The same set of relations, once evaluated on elliptic Calabi-Yau three-folds and four-folds, is shown to universally govern the structure of anomalies and their Green-Schwarz cancellation in six- and four-dimensional F-theory vacua, respectively. We furthermore conjecture that these relations hold not only within the cohomology ring, but even at the level of the Chow ring, i.e. as relations among codimension-two cycles modulo rational equivalence. We verify this conjecture in non-trivial examples with Abelian and non-Abelian gauge groups factors. Apart from governing the structure of local anomalies, the identities in the Chow ring relate different types of gauge backgrounds on elliptically fibred Calabi-Yau four-folds.
NASA Astrophysics Data System (ADS)
Makhov, D. V.; Lewis, Laurent J.
2005-05-01
The positron lifetimes for various vacancy clusters in silicon are calculated within the framework of the two-component electron-positron density functional theory. The effect of the trapped positron on the electron density and on the relaxation of the structure is investigated. Our calculations show that, contrary to the usual assumption, the positron-induced forces do not compensate in general for electronic inward forces. Thus, geometry optimization is required in order to determine positron lifetime accurately. For the monovacancy and the divacancy, the results of our calculations are in good agreement with the experimental positron lifetimes, suggesting that this approach gives good estimates of positron lifetimes for larger vacancy clusters, required for their correct identification with positron annihilation spectroscopy. As an application, our calculations show that fourfold trivacancies and symmetric fourfold tetravacancies have positron lifetimes similar to monovacancies and divacancies, respectively, and can thus be confused in the interpretation of positron annihilation experiments.
Activity of semisynthetic penicillins and synergism with mecillinam against Bacteroides species.
Trestman, I; Kaye, D; Levison, M E
1979-01-01
The minimal inhibitory concentrations (MIC) of six penicillins (ampicillin, carbenicillin, ticarcillin, piperacillin, mezlocillin, and Bay k 4999) against 29 clinical isolates of Bacteriodes spp. (including Bacteroides fragilis, Bacteroides thetaiotaomicron, and Bacteroides vulgatus) were determined by an agar dilution method. Bay k 4999 was most active, followed in descending order by ampicillin, piperacillin, mezlocillin, ticarcillin, and carbenicillin. Mecillinam, a 6 beta-amidino-penicillanic acid, inhibited no strains at 50 micrograms/ml, but when compared with ampicillin, a fourfold or greater increase in MIC for ampicillin (antagonism) was noted in 3 of 29 strains, with no effect on MIC for 26 strains, whereas when combined with carbenicillin, a fourfold or greater decrease in MIC for both antibiotics (synergism) was noted in 12 strains, 4 of which had an MIC of greater than or equal to 250 micrograms/ml for carbenicillin alone. These studies demonstrate the increased activity of some newer semisynthetic penicillins and the potential synergy obtained with mecillinam and carbenicillin against Bacteroides sp. PMID:228593
Radial symmetry in a chimeric glutamate receptor pore
NASA Astrophysics Data System (ADS)
Wilding, Timothy J.; Lopez, Melany N.; Huettner, James E.
2014-02-01
Ionotropic glutamate receptors comprise two conformationally different A/C and B/D subunit pairs. Closed channels exhibit fourfold radial symmetry in the transmembrane domain (TMD) but transition to twofold dimer-of-dimers symmetry for extracellular ligand binding and N-terminal domains. Here, to evaluate symmetry in open pores we analysed interaction between the Q/R editing site near the pore loop apex and the transmembrane M3 helix of kainate receptor subunit GluK2. Chimeric subunits that combined the GluK2 TMD with extracellular segments from NMDA receptors, which are obligate heteromers, yielded channels made up of A/C and B/D subunit pairs with distinct substitutions along M3 and/or Q/R site editing status, in an otherwise identical homotetrameric TMD. Our results indicate that Q/R site interaction with M3 occurs within individual subunits and is essentially the same for both A/C and B/D subunit conformations, suggesting that fourfold pore symmetry persists in the open state.
Ursell, Paul G; Dhariwal, Mukesh; Majirska, Katarina; Ender, Frank; Kalson-Ray, Shoshannah; Venerus, Alessandra; Miglio, Cristiana; Bouchet, Christine
2018-06-11
To evaluate 3-year incidence of Nd:YAG capsulotomy and PCO and compare the effect of different IOL materials. Data were retrospectively collected from seven UK ophthalmology clinics using Medisoft electronic medical records. Eyes from patients ≥65 years undergoing cataract surgery with implantation of acrylic monofocal IOLs during 2010-2013 and 3-year follow-up were analysed. Nd:YAG capsulotomy and PCO incidence proportions were reported for 3 IOL cohorts: AcrySof, other hydrophobic and hydrophilic acrylic IOLs. Unadjusted/adjusted odds ratios (OR) of Nd:YAG capsulotomy were calculated through logistic regression for non-AcrySof cohorts versus AcrySof. A sub-group analysis in single-piece IOLs (>90% of sample eyes) was also performed. The AcrySof cohort included 13,329 eyes, non-AcrySof hydrophobic 19,025 and non-AcrySof hydrophilic 19,808. The 3-year Nd:YAG capsulotomy incidence (95% CI) for AcrySof (2.4%, 2.2-2.7%) was approximately two times lower than non-AcrySof hydrophobic IOLs (4.4%, 4.1-4.7%) and approximately fourfold lower than non-AcrySof hydrophilic IOLs (10.9%, 10.5-11.3%). Trends were similar in PCO incidence (AcrySof: 4.7%; non-AcrySof hydrophobic: 6.3%; non-AcrySof hydrophilic: 14.8%). Also in the analysis restricted to single-piece IOLs, the pattern remained (2.4% vs 5.1% vs. 10.9%, respectively). Adjusted regression analysis showed a approximately two and fivefold increased odds of Nd:YAG for non-AcrySof hydrophobic and hydrophilic acrylic IOLs respectively vs. AcrySof IOLs. Nd:YAG capsulotomy ORs were similar and remained statistically significant in the single-piece IOL sub-group. Real-world evidence shows that within 3 years following implantation, AcrySof IOLs are significantly superior in reducing Nd:YAG capsulotomy and PCO incidence compared to other hydrophilic and hydrophobic acrylic IOLs.
Rodríguez-Quiñones, F; Bosch, R; Imperial, J
1993-01-01
The nifBQ transcriptional unit of Azotobacter vinelandii has been previously shown to be required for activity of the three nitrogenase systems, Mo nitrogenase, V nitrogenase, and Fe nitrogenase, present in this organism. We studied regulation of expression and the role of the nifBQ region by means of translational beta-galactosidase fusions to each of the five open reading frames: nifB, orf2 (fdxN), orf3 (nifO), nifQ, and orf5. Expression of the first three open reading frames was observed under all three diazotrophic conditions; expression of orf5 was never observed. Genes nifB and fdxN were expressed at similar levels. With Mo, expression of nifO and nifQ was approximately 20- and approximately 400-fold lower than that of fdxN, respectively. Without Mo, expression of nifB dropped three- to fourfold and that of nifQ dropped to the detection limit. However, expression of nifO increased threefold. The products of nifB, fdxN, nifO, and nifQ have been visualized in A. vinelandii as beta-galactosidase fusion proteins with the expected molecular masses. The NifB- fusion lacked activity for any of the three nitrogenase systems and showed an iron-molybdenum cofactor-deficient phenotype in the presence of Mo. The FdxN- mutation resulted in reduced nitrogenase activities, especially when V was present. Dinitrogenase activity in extracts was similarly affected, suggesting a role of FdxN in iron-molybdenum cofactor synthesis. The NifO(-)-producing mutation did not affect any of the nitrogenases under standard diazotrophic conditions. The NifQ(-)-producing mutation resulted in an increased (approximately 1,000-fold) Mo requirement for Mo nitrogenase activity, a phenotype already observed with Klebsiella pneumoniae. No effect of the NifQ(-)-producing mutation on V or Fe nitrogenase was found; this is consistent with its very low expression under those conditions. Mutations in orf5 had no effect on nitrogenase activity. Images PMID:8491713
ORD's four-fold objectives in its efforts have been to: (i) Identify potential (future) environmental concerns (anticipatory research and identification of emerging issues, especially to identify pivotal sources of uncertainty that might affect risk estimates), (ii) Be proactive ...
Anthropocene Survival of Southern New England’s Salt Marshes
In southern New England, salt marshes are exceptionally vulnerable to the impacts of accelerated sea level rise. Regional rates of sea level rise have been as much as 50 % greater than the global average over past decades, a more than fourfold increase over late Holocene backgrou...
Bond-orientational analysis of hard-disk and hard-sphere structures.
Senthil Kumar, V; Kumaran, V
2006-05-28
We report the bond-orientational analysis results for the thermodynamic, random, and homogeneously sheared inelastic structures of hard-disks and hard-spheres. The thermodynamic structures show a sharp rise in the order across the freezing transition. The random structures show the absence of crystallization. The homogeneously sheared structures get ordered at a packing fraction higher than the thermodynamic freezing packing fraction, due to the suppression of crystal nucleation. On shear ordering, strings of close-packed hard-disks in two dimensions and close-packed layers of hard-spheres in three dimensions, oriented along the velocity direction, slide past each other. Such a flow creates a considerable amount of fourfold order in two dimensions and body-centered-tetragonal (bct) structure in three dimensions. These transitions are the flow analogs of the martensitic transformations occurring in metals due to the stresses induced by a rapid quench. In hard-disk structures, using the bond-orientational analysis we show the presence of fourfold order. In sheared inelastic hard-sphere structures, even though the global bond-orientational analysis shows that the system is highly ordered, a third-order rotational invariant analysis shows that only about 40% of the spheres have face-centered-cubic (fcc) order, even in the dense and near-elastic limits, clearly indicating the coexistence of multiple crystalline orders. When layers of close-packed spheres slide past each other, in addition to the bct structure, the hexagonal-close-packed (hcp) structure is formed due to the random stacking faults. Using the Honeycutt-Andersen pair analysis and an analysis based on the 14-faceted polyhedra having six quadrilateral and eight hexagonal faces, we show the presence of bct and hcp signatures in shear ordered inelastic hard-spheres. Thus, our analysis shows that the dense sheared inelastic hard-spheres have a mixture of fcc, bct, and hcp structures.
Legionnaire's disease: a nosocomial outbreak in Turkey.
Ozerol, I H; Bayraktar, M; Cizmeci, Z; Durmaz, R; Akbas, E; Yildirim, Z; Yologlu, S
2006-01-01
Six nosocomial cases of Legionella pneumophila occurred over a two-week period, with one further case being diagnosed retrospectively after 30 days. Strains isolated from the hospital water system were clonally related to a single sputum isolate. A sero-epidemiological investigation into legionella exposure amongst staff and inpatients was undertaken at the eight-year-old Inonu University Medical Centre in Turkey, which has 600 beds and central air conditioning. There is no disinfection programme for the hospital water system. A total of 500 serum samples (400 hospital staff and 100 inpatients) were screened for antibody to L. pneumophila by enzyme-linked immunosorbent assay (ELISA). Seroreactive cases were confirmed by a four-fold antibody rise in ELISA, a high indirect immunofluorescent assay (IFA) antibody titre or a positive urinary antigen test. ELISA showed that 24 (6%) of the 400 hospital staff and seven (7%) of the 100 inpatients had antibody titres higher than the cut-off value. ELISA-seroreactive cases were followed for two to four weeks. Of these subjects, seven (three patients and four staff) showed a four-fold rise in antibody titre by ELISA, six (three patients and three staff) had a high IFA titre, three patients with pneumonia had a positive urinary antigen test, and one of these patients also had a positive sputum culture. In addition, 22 water distribution systems were screened for the presence of L. pneumophila by culture. L. pneumophila was isolated from 15 sites. Pulsed-field gel electrophoresis typing indicated that all strains isolated from water systems were identical and clonally related to the strain isolated from sputum. Superheating and flushing of water systems were undertaken with legionella being re-isolated from four sites. Repeated superheating and flushing eliminated legionella completely. This study demonstrated that rapid detection of L. pneumophila and adequate superheating and flushing of water systems are effective for elimination and reduction of spread of this organism.
POLLUTION FROM THE COMBINED ACTIVITIES, ACTIONS ...
ORD's four-fold objectives in its efforts have been to: (i) Identify potential (future) environmental concerns (anticipatory research and identification of emerging issues, especially to identify pivotal sources of uncertainty that might affect risk estimates), (ii) Be proactive versus reactive (allowing for pollution prevention versus remediation/restoration; identify and foster investigation of
Baby Boomers and the Shifting Political Construction of Old Age
ERIC Educational Resources Information Center
Hudson, Robert B.; Gonyea, Judith G.
2012-01-01
Employing the political construct of "target" populations, we suggest that the Boomers in old age will constitute a conceptually distinct population from that represented by either their parents or grandparents. A fourfold typology organized along the dimensions posited by Schneider and Ingram (1993) yields categorizations of target populations as…
Superposition: New Solutions from Known Solutions
ERIC Educational Resources Information Center
Roberts, Charles E.
2003-01-01
This note contains material to be presented to students in a first course in differential equations immediately after they have completed studying first-order differential equations and their applications. The purpose of presenting this material is four-fold: to review definitions studied previously; to provide a historical context which cites the…
New Algorithms Manage Fourfold Redundancy
NASA Technical Reports Server (NTRS)
Gelderloos, H. C.
1982-01-01
Redundant sensors, actuators, and computers improve reliability of complex control systems, such as those in nuclear powerplants and aircraft. If one or more redundant elements fail, another takes over so that normal operation is not interrupted. Quad selection filter rejects data from null-failed and hardover-failed and hardover-failed units.
Yu-Mei, Lee; Hsueh-Hua, Yao
2013-09-01
The incidence of breast cancer has had a four-fold increase from 1980 to 2005 in Taiwan. Limited data have been available on mobile breast screening in the Taiwanese population since 2009. This study aims at investigating the factors influencing consensus opinion on the recall for mobile breast screening in Taiwan. The factors were categorized by individual health background, socioeconomic status and knowledge about breast screening. There were 502 questionnaires collected from Taiwanese women examined on mobile mammography screening vehicle. Data were then analyzed by SPSS 12 via analysis of variance (ANOVA), F-test, t-test or chi-square test. Strong participation was associated with a younger age, higher educational level, higher incomes, previous history of cancer, previous family history of cancer, one or two prior mammographies, more correct recognitions of mammography, recall rate, and breast cancer risk. If the false-positive result occurred, 83.9%, 81.9% and 77.3% of the women agreed or strongly agreed to participate in noninvasive and invasive testing and screening mammography, respectively. The policy makers should notify the importance of demographic factors affecting further examination for early detection of breast cancer in Taiwan.
Thermophotonics for ultra-high efficiency visible LEDs
NASA Astrophysics Data System (ADS)
Ram, Rajeev J.
2017-02-01
The wall-plug efficiency of modern light-emitting diodes (LEDs) has far surpassed all other forms of lighting and is expected to improve further as the lifetime cost of a luminaire is today dominated by the cost of energy. The drive towards higher efficiency inevitably opens the question about the limits of future enhancement. Here, we investigate thermoelectric pumping as a means for improving efficiency in wide-bandgap GaN based LEDs. A forward biased diode can work as a heat pump, which pumps lattice heat into the electrons injected into the active region via the Peltier effect. We experimentally demonstrate a thermally enhanced 450 nm GaN LED, in which nearly fourfold light output power is achieved at 615 K (compared to 295 K room temperature operation), with virtually no reduction in the wall-plug efficiency at bias V < ℏω/q. This result suggests the possibility of removing bulky heat sinks in high power LED products. A review of recent high-efficiency GaN LEDs suggests that Peltier thermal pumping plays a more important role in a wide range of modern LED structures that previously thought - opening a path to even higher efficiencies and lower lifetime costs for future lighting.
Electron beam observation opportunity
NASA Astrophysics Data System (ADS)
Raitt, John; Banks, Peter
Ionospheric researchers will have the opportunity to conduct coordinated radio, radar, and optical observations in conjunction with other space-based electron beam experiments as part of the upcoming Cooperative High-Altitude Rocket Gun Experiments (CHARGE) 3 rocket flight in November 1988 at White Sands Missile Range (WSMR, White Sands, N.Mex.). The flight will be particularly interesting because of the high power planned for the electron gun (3.5 kV at 5 A), which is based, in part, on technology developments planned for the successful Excede series of rockets.CHARGE 3 is the third in a series of U.S. flights made in collaboration with investigators from Utah State University (Logan), Stanford University (Stanford, Calif.), the Institute for Space and Astronautical Sciences (Sendai, Japan), and the University of Michigan (Ann Arbor). The general objectives for CHARGE 3 are fourfold: to study vehicle charging and diagnosecontributory effects at higher beam currents and energy,to study ELF/VLF wave generation and propagation from dc and modulated electron beams,to diagnose beam propagation remotely by studying E region ionization and optical excitation, andto investigate voltage and current distribution in an electrically tethered space vehicle system at higher beam currents.
Regional variation of nonrural pediatric ambulance transport rates: an ecological study.
Maio, R F; Tedeschi, P; Swor, R; Krohmer, J; Ferrel, R; Jacques, D L
1996-08-01
To determine the relationship of pediatric transport rates per hundred thousand pediatric population (RATE) to socioeconomic status (SES) factors and also mortality in Emergency Medical Services (EMS) systems. Retrospective ecological study. Four EMS Medical Control Authorities (MCAs) in Michigan. Patients (3,792), 0-19 years of age, responded to as a nonscheduled emergency response and transported to a hospital by ambulance. RATE, economic status (INCOME), private transportation status (VEHICLE), educational status (EDUC), primary care physician availability (PHYS), and EMS disease death rate (EMSDD) were determined for each MCA and analyzed using Spearman rank correlation. RATE between MCAs varied from 325 to 750. RATE was highest in the most urban MCA: its 0-4 RATE was fourfold larger than any other MCA. INCOME, EDUC, and VEHICLE were inversely correlated with transport rate: -1.00, -1.00, -1.00; P < 0.001. Rate was positively correlated with EMSDD: 1.00; P < 0.001. Substantial variation in RATE between MCAs may be primarily due to the high 0-4 transport rate in the most urban MCA. This study also suggests that higher pediatric EMS system utilization rates may be correlated to higher mortality and also to unavailability of personal transportation.
The effects of diet and breed on the volatile compounds of cooked lamb.
Elmore, J S; Mottram, D S; Enser, M; Wood, J D
2000-06-01
The effect of varying the n-3 polyunsaturated fatty acid (PUFA) composition of lamb muscle on the formation of aroma volatiles during cooking has been examined. The meat was obtained from four groups of Suffolk and Soay lambs fed different supplementary fats: a palm-oil based control; bruised whole linseed, which increased muscle levels of α-linolenic acid (C18:3 n-3); fish oil, which increased eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3); and equal quantities of linseed and fish oil (fat basis). Higher quantities of lipid oxidation products were found in the aroma volatiles of lamb muscle from animals fed fish oil, compared to the control. In particular, unsaturated aldehydes, unsaturated hydrocarbons and alkylfurans increased up to fourfold. These compounds derived from the autoxidation of PUFAs during cooking. Although some of these volatiles were increased in meat from animals fed the linseed supplement, the effect was not as great as with the fish oil fed lambs. Levels of volatiles derived from the Maillard reaction, such as pyrazines and sulfur compounds, were up to four times higher in Soays than Suffolks.
Ortiz, Mario I
2013-01-01
BACKGROUND There is evidence that biguanides and sulfonylureas block diclofenac-induced antinociception (DIA) in rat models. However, little is known about the interaction between these hypoglycemics with respect to DIA. OBJECTIVE: To determine whether metformin-sulfonylurea combinations affect DIA during the formalin test. METHODS: Rats received the appropriate vehicle or diclofenac before 1% formaldehyde was injected into the paw. Rats were also pretreated with vehicle, glibenclamide, glipizide, metformin or glibenclamide/metformin and glipizide/metformin combinations before the diclofenac and formaldehyde injections, and the effect on antinociception was assessed. Isobolograms of the combinations were constructed to test for a synergistic interaction. RESULTS: Systemic injection of diclofenac resulted in antinociception during the second phase of the test. Systemic pretreatment with the combinations of glibenclamide (0.56 mg/kg to 10 mg/kg)/metformin (10 mg/kg to 180 mg/kg) and glipizide (0.56 mg/kg to10 mg/kg)/metformin (10 mg/kg to 180 mg/kg) blocked DIA. The derived theoretical effective doses for 50% of subjects (ED50) for the glibenclamide/metformin and glipizide/metformin combinations were 32.52 mg/kg and 32.42 mg/kg, respectively, and were significantly higher than the actual observed experimental ED50 values (7.57 mg/kg and 8.43 mg/kg, respectively). CONCLUSION: Pretreatment with glibenclamide, glipizide or metformin blocked DIA in a dose-dependent manner, and combining either sulfonylurea with metformin produced even greater effects. The observed ED50s for the combinations were approximately fourfold lower than the calculated additive effects. These data indicate that sulfonylureas interact to produce antagonism of DIA. Combination therapy is a common second-line treatment for patients with diabetes and metabolic syndrome, a group that experiences pain from multiple sources. The results suggest that at least some anti-inflammatory agents may not be effective in this group. PMID:23985578
Increased wintertime CO2 loss as a result of sustained tundra warming
NASA Astrophysics Data System (ADS)
Webb, Elizabeth E.; Schuur, Edward A. G.; Natali, Susan M.; Oken, Kiva L.; Bracho, Rosvel; Krapek, John P.; Risk, David; Nickerson, Nick R.
2016-02-01
Permafrost soils currently store approximately 1672 Pg of carbon (C), but as high latitudes warm, this temperature-protected C reservoir will become vulnerable to higher rates of decomposition. In recent decades, air temperatures in the high latitudes have warmed more than any other region globally, particularly during the winter. Over the coming century, the arctic winter is also expected to experience the most warming of any region or season, yet it is notably understudied. Here we present nonsummer season (NSS) CO2 flux data from the Carbon in Permafrost Experimental Heating Research project, an ecosystem warming experiment of moist acidic tussock tundra in interior Alaska. Our goals were to quantify the relationship between environmental variables and winter CO2 production, account for subnivean photosynthesis and late fall plant C uptake in our estimate of NSS CO2 exchange, constrain NSS CO2 loss estimates using multiple methods of measuring winter CO2 flux, and quantify the effect of winter soil warming on total NSS CO2 balance. We measured CO2 flux using four methods: two chamber techniques (the snow pit method and one where a chamber is left under the snow for the entire season), eddy covariance, and soda lime adsorption, and found that NSS CO2 loss varied up to fourfold, depending on the method used. CO2 production was dependent on soil temperature and day of season but atmospheric pressure and air temperature were also important in explaining CO2 diffusion out of the soil. Warming stimulated both ecosystem respiration and productivity during the NSS and increased overall CO2 loss during this period by 14% (this effect varied by year, ranging from 7 to 24%). When combined with the summertime CO2 fluxes from the same site, our results suggest that this subarctic tundra ecosystem is shifting away from its historical function as a C sink to a C source.
Biological risk factors for deep vein trombosis.
Vayá, Amparo; Mira, Yolanda; Martínez, Marcial; Villa, Piedad; Ferrando, Fernando; Estellés, Amparo; Corella, Dolores; Aznar, Justo
2002-01-01
Hypercoagulable states due either to inherited or acquired thrombotic risk factors are only present in approximately half of cases of DVT, but the causes in the other half, remain unknown. The importance of biological risk factors such as hyperlipidemia, hypofibrinolysis and hemorheological alterations in the pathogenesis of DVT has not been well established. In order to ascertain whether the above mentioned biological factors are associated with DVT and could constitute independent risk factors, we carried out a case-control study in 109 first DVT patients in whom inherited or acquired thrombophilic risk factors had been ruled out and 121 healthy controls age (42+/-15 years) and sex matched. From all the biological variables analyzed (cholesterol, triglycerides, glucose, fibrinogen, erythrocyte aggregation, hematocrit, plasma viscosity and PAI-1) only fibrinogen concentration reached a statistically significant difference on the comparison of means (290+/-73 mg/dl in cases vs 268+/-58 mg/dl in controls, p<0.05). After this continuous variables were dichotomized according to our reference values, the percentage of cases with cholesterolemia >220 mg/dl, hematocrit >45% and fibrinogen >300 mg/dl was higher in cases than in controls: 38% vs 22%; p<0.01; 43% vs 27%; p<0.05; 36% vs 23%; p<0.05, respectively. The percentage of cases with PAI-1 values >30 ng/ml, 37% vs 25% was borderline significant; p=0.055. Multivariate logistic regression analysis showed that cholesterolemia >220 mg/dl and fibrinogen >300 mg/dl constitute independent predictors of venous thrombotic risk. The adjusted OR's were 2.03 (95% CI; 1.12-3.70) for cholesterolemia and 1.94 (95% CI; 1.07-3.55) for fibrinogen. When these two variables combined DVT risk rose about fourfold (3.96; p<0.05). Our results suggest that hypercholesterolemia and hyperfibrinogenemia should be added to the list of known DVT risk factors and we recommend adopting measures to decrease these variables in the population with a high risk of DVT.
Boutriau, Dominique; Poolman, Jan; Borrow, Ray; Findlow, Jamie; Domingo, Javier Diez; Puig-Barbera, Joan; Baldó, José María; Planelles, Victoria; Jubert, Angels; Colomer, Julia; Gil, Angel; Levie, Karin; Kervyn, Anne-Diane; Weynants, Vincent; Dominguez, Francisco; Barberá, Ramon; Sotolongo, Franklin
2007-01-01
An experimental bivalent meningococcal outer membrane vesicle (OMV) vaccine (B:4:P1.19,15 and B:4:P1.7-2,4) has been developed to provide wide vaccine coverage particularly of the circulating strains in Europe. A randomized, controlled phase II study (study identification number, 710158/002; ClinicalTrials.gov identifier number, NCT00137917) to evaluate the immunogenicity and safety of three doses of the OMV vaccine when given to healthy 12- to 18-year-olds on a 0-2-4 month (n = 162) or 0-1-6 month schedule (n = 159). A control group received two doses of hepatitis A and one of conjugated meningococcal serogroup C vaccine on a 0-1-6 month schedule (n = 157). Immune response, defined as a fourfold increase in serum bactericidal titer using a range of vaccine-homologous or PorA-related and heterologous strains, was determined for samples taken before and 1 month after vaccination; assays were performed at two laboratories. As measured at the GlaxoSmithKline (GSK) laboratory, the OMV vaccine induced an immune response against homologous or PorA-related strains (in at least 51% of subjects against strains of serosubtype P1.19,15 and at least 66% against strains of serosubtype P1.7-2,4) and against a set of three heterologous strains (in 28% to 46% of subjects). Both laboratories showed consistent results for immune response rates. The OMV vaccine had a similar reactogenicity profile for each schedule. Pain preventing normal activities occurred in approximately one-fifth of the subjects; this was significantly higher than in the control group. The immune responses induced by the bivalent OMV vaccine demonstrated the induction of bactericidal antibodies against the vaccine-homologous/PorA-related strains but also against heterologous strains, indicating the presence of protective antigens in OMVs and confirming the potential of clinical cross-protection. PMID:17065257
Kayser, Claudia; Larkin, Tam; Singhal, Naresh
2015-12-01
Residuals from wastewater treatment operations (biosolids) were mixed with lime, fly ash, lime kiln dust, or two smelter slags to assess their efficacy as potential stabilisation agents by assessing their effects on the shear strength, compressibility, and solids content of mixtures. In addition, the minerals formed and leachate produced during stabilisation were determined. Tests were performed to explore the change of the geoenvironmental properties of the amended biosolids, while under pressure, at different scales using laboratory, pilot and field scale tests. The settlement characteristics of the amended biosolids under a range of applied pressures were determined using a consolidometer. All amended biosolids mixtures showed higher strength than the unamended biosolids, with mixtures containing a combination of 20% fly ash and 20% lime giving the highest (up to eightfold) increase in strength, and that with lime kiln dust and the smelter slags showing the lowest (up to twofold). The biosolids mixtures with only lime gave the second highest increase in strength (up to fourfold), but produced the largest amount of leachate, with higher level of dissolved calcium. The increase in strength correlated with availability of calcium oxide in the mixtures which lead to calcium carbonate formation, accompanied with higher leachate production and settlement during consolidation. Copper, nickel and zinc concentrations increased with alkaline additives and corresponded to higher pH and DOC levels. Nonetheless, concentrations were within the New Zealand regulatory limits for Class A landfills. Copyright © 2015 Elsevier Ltd. All rights reserved.
Feng, Christina; Anandalwar, Seema; Sidhwa, Feroze; Glass, Charity; Karki, Mahima; Zurakowski, David; Rangel, Shawn J
2016-11-01
The purpose of the study was to explore the relationship between the degree of peritoneal contamination and postoperative resource utilization in children with complicated appendicitis. Intraoperative findings were collected prospectively at a single children's hospital from 2012 to 2014. The degree of peritoneal contamination was categorized as either "localized" (confined to the right lower quadrant and pelvis) or "extensive" (extending to the liver). Imaging utilization, postoperative length of stay (pLOS), hospital cost, and readmission rates were compared between groups. Of 88 patients with complicated appendicitis, 38% had extensive contamination. Preoperative characteristics were similar between groups. Patients with extensive contamination had higher rates of postoperative imaging (58.8% vs 27.7%, P<0.01), a 50% longer median pLOS (6days [IQR 4-9] vs 4days [IQR 2-5], P=0.003), a 30% higher median hospital cost ($17,663 [IQR $12,564-$23,697] vs $13,516 [IQR $10,546-$16,686], P=0.004), and a nearly four-fold higher readmission rate (20.6% vs 5.6%, P=0.04) compared to children with localized contamination. Extensive peritoneal contamination is associated with significantly higher resource utilization compared to localized contamination in children with complicated appendicitis. These findings may have important severity-adjustment implications for reimbursement and readmission rate reporting for hospitals that serve populations where late presentation is common. Copyright © 2016 Elsevier Inc. All rights reserved.
Optimisation Modelling to Assess Cost of Dietary Improvement in Remote Aboriginal Australia
Brimblecombe, Julie; Ferguson, Megan; Liberato, Selma C.; O'Dea, Kerin; Riley, Malcolm
2013-01-01
Background The cost and dietary choices required to fulfil nutrient recommendations defined nationally, need investigation, particularly for disadvantaged populations. Objective We used optimisation modelling to examine the dietary change required to achieve nutrient requirements at minimum cost for an Aboriginal population in remote Australia, using where possible minimally-processed whole foods. Design A twelve month cross-section of population-level purchased food, food price and nutrient content data was used as the baseline. Relative amounts from 34 food group categories were varied to achieve specific energy and nutrient density goals at minimum cost while meeting model constraints intended to minimise deviation from the purchased diet. Results Simultaneous achievement of all nutrient goals was not feasible. The two most successful models (A & B) met all nutrient targets except sodium (146.2% and 148.9% of the respective target) and saturated fat (12.0% and 11.7% of energy). Model A was achieved with 3.2% lower cost than the baseline diet (which cost approximately AUD$13.01/person/day) and Model B at 7.8% lower cost but with a reduction in energy of 4.4%. Both models required very large reductions in sugar sweetened beverages (−90%) and refined cereals (−90%) and an approximate four-fold increase in vegetables, fruit, dairy foods, eggs, fish and seafood, and wholegrain cereals. Conclusion This modelling approach suggested population level dietary recommendations at minimal cost based on the baseline purchased diet. Large shifts in diet in remote Aboriginal Australian populations are needed to achieve national nutrient targets. The modeling approach used was not able to meet all nutrient targets at less than current food expenditure. PMID:24391790
Stratigraphy and paleohydrology of delta channel deposits, Jezero crater, Mars
NASA Astrophysics Data System (ADS)
Goudge, Timothy A.; Mohrig, David; Cardenas, Benjamin T.; Hughes, Cory M.; Fassett, Caleb I.
2018-02-01
The Jezero crater open-basin lake contains two well-exposed fluvial sedimentary deposits formed early in martian history. Here, we examine the geometry and architecture of the Jezero western delta fluvial stratigraphy using high-resolution orbital images and digital elevation models (DEMs). The goal of this analysis is to reconstruct the evolution of the delta and associated shoreline position. The delta outcrop contains three distinct classes of fluvial stratigraphy that we interpret, from oldest to youngest, as: (1) point bar strata deposited by repeated flood events in meandering channels; (2) inverted channel-filling deposits formed by avulsive distributary channels; and (3) a valley that incises the deposit. We use DEMs to quantify the geometry of the channel deposits and estimate flow depths of ∼7 m for the meandering channels and ∼2 m for the avulsive distributary channels. Using these estimates, we employ a novel approach for assessing paleohydrology of the formative channels in relative terms. This analysis indicates that the shift from meandering to avulsive distributary channels was associated with an approximately four-fold decrease in the water to sediment discharge ratio. We use observations of the fluvial stratigraphy and channel paleohydrology to propose a model for the evolution of the Jezero western delta. The delta stratigraphy records lake level rise and shoreline transgression associated with approximately continuous filling of the basin, followed by outlet breaching, and eventual erosion of the delta. Our results imply a martian surface environment during the period of delta formation that supplied sufficient surface runoff to fill the Jezero basin without major drops in lake level, but also with discrete flooding events at non-orbital (e.g., annual to decadal) timescales.
Syllabus for a Course in File Management. Curriculum for the Information Sciences, Report No. 9.
ERIC Educational Resources Information Center
Carroll, John M.
The course treats the organization and structure of files including relationships between information representation and processing techniques, transformations between storage media, and the referencing of information as related to the structure of its representation. The intent of the course is fourfold: (a) To teach the underlying principles of…
Minnesota's Fiscal Years 1998-1999 Budget: An Opportunity for Children & Their Families.
ERIC Educational Resources Information Center
Jefferys, Marcie
This report presents the Children's Defense Fund's (CDF) recommendations for spending the fiscal year 1998-1999 Minnesota state budget surplus. The intent of the CDF plan is four-fold: (1) emphasizing long-term investments in children's well-being; (2) address children's immediate health and safety concerns; (3) contribute to the continued…
The Use of Technology and Visualization in Calculus Instruction
ERIC Educational Resources Information Center
Samuels, Jason
2010-01-01
This study was inspired by a history of student difficulties in calculus, and innovation in response to those difficulties. The goals of the study were fourfold. First, to design a mathlet for students to explore local linearity. Second, to redesign the curriculum of first semester calculus around the use of technology, an emphasis on…
Reflections on Strategic Enrollment Management Structures and Strategies. Part Three
ERIC Educational Resources Information Center
Kalsbeek, David H.
2007-01-01
This article is the third and final in a series prepared originally for AACRAO's Fifteenth Annual Strategic Enrollment Management Conference (SEM XV). Through this series, David Kalsbeek introduces a four-fold typology for differentiating institutional approaches to SEM. In this final reflection, he suggests that grounding this typology in Jungian…
Accessible GPS: Reorientation and Target Location among Users with Visual Impairments
ERIC Educational Resources Information Center
Ponchillia, Paul E.; Rak, Eniko C.; Freeland, Amy L.; LaGrow, Steven J.
2007-01-01
This article presents the results of two single-subject experiments that were designed to determine consumers' ability to use a BrailleNote GPS. The participants decreased their mean orientation time from 6 minutes to 45 seconds and increased their target-location efficiency fourfold with BGPS than without BGPS. Additional results and implications…
Beginning Teachers' Job Satisfaction: The Impact of School-Based Factors
ERIC Educational Resources Information Center
Lam, Bick-har; Yan, Hoi-fai
2011-01-01
Using a longitudinal design, the job satisfaction and career development of beginning teachers are explored in the present study. Beginning teachers were initially interviewed after graduation from the teacher training programme and then after gaining a two-year teaching experience. The results are presented in a fourfold typology in which the…
Development of Academic Goal Orientation Inventory for Senior Secondary School Students of Kerala
ERIC Educational Resources Information Center
Gafoor, K. Abdul; Abidha, Kurukkan
2015-01-01
Research interest in achievement motivation and its correlates has grown in recent years. Though there are thousands of studies on goal orientation, the number of instruments to identify goal orientation based on four-fold model viz., performance approach goal orientation (PAP), performance avoidance goal orientation (PAV), mastery approach goal…
The Waldorf Curriculum as a Framework for Moral Education: One Dimension of a Fourfold System.
ERIC Educational Resources Information Center
Armon, Joan
This paper examines moral education as a holistic structure that evolves from the interplay between the educational applications of anthroposophy, students' developmental needs, the curriculum, as indicated by Rudolf Steiner, and teachers' roles in fashioning the curriculum. The methodology draws upon the qualitative research paradigm of…
Trends in Southern pulpwood production, 1953-1993
Tony G. Johnson
1996-01-01
Southern pulpwood production has increased more than fourfold from 16.2 million cords in 1953 to 66.3 million cords in 1993. Softwood roundwood production more than doubled in the same time period; however, softwood production expressed as a proportion of the total production dramatically declined. In contrast, hardwood roundwood production and production from residues...
Li, Wei; Huang, Li; Evans, James W.; ...
2016-04-11
Epitaxial growth of Ag on Fe(100) and postdeposition relaxation have been studied in several experiments. We provide a first-principles density functional theory analysis of key adatom interaction energies and diffusion barriers controlling growth and relaxation kinetics for the submonolayer regime, as these have not been assessed previously. A cluster expansion approach is used to obtain an extensive set of conventional lateral interactions between adatoms on fourfold hollow adsorption sites. We find robust oscillatory decay of pair interactions with increasing separation, and of trio interactions with increasing perimeter length. First- and second-nearest-neighbor pair interactions, as well as compact linear and bentmore » trio interactions, dominate. The adatom terrace diffusion barrier is estimated to be E d ≈ 0.39 eV. We also provide a limited analysis of unconventional interactions for which one adatom is at the bridge-site transition state for hopping and one or more others are at fourfold hollow sites. Furthermore, energy barriers for diffusion along island edges can be determined with the aid of both conventional and unconventional interactions.« less
Bilastine: a new H1 -antihistamine with an optimal profile for updosing in urticaria.
Church, M K; Labeaga, L
2017-09-01
This review set out to examine published papers detailing the efficacy of bilastine in skin models and urticaria to assess whether it meets the optimal profile for updosing in urticaria, that is, strong clinical efficacy and freedom from unwanted side effects, particularly sedation. Bilastine is a highly effective H 1 -antihistamine even when used at the basic dose of 20 mg daily. Its facilitated uptake after oral dosage gives it a rapid onset and long duration of action. In both wheal and flare studies and in urticaria updosing fourfold showed increased effectiveness. With respect to somnolence, bilastine is a substrate for P-glycoprotein, a membrane pump which prevents it crossing the blood-brain barrier. Consequently, bilastine is a practically 'non-sedating' H 1 -antihistamine. In conclusion, the excellent profile of bilastine in both efficacy and safety make it the ideal H 1 -antihistamine for updosing the daily dose fourfold in difficult-to-treat urticaria as recommended by the EAACI/GA 2 LEN/EDF/WAO guideline for the management of urticaria. © 2017 European Academy of Dermatology and Venereology.
Medlin, H K; Zhu, Y Q; Remington, K M; Phillips, T R; North, T W
1996-01-01
We have selected and plaque purified a mutant of feline immunodeficiency virus (FIV) that is resistant to 2',3'-dideoxycytidine (ddC). This mutant was selected in cultured cells in the continuous presence of 25 microM ddC. The mutant, designated DCR-5c, was fourfold resistant to ddC, threefold resistant to 2',3'-dideoxyinosine, and more than fourfold resistant to phosphonoformic acid. DCR-5c displayed little or no resistance to (-)-beta-2',3'-dideoxy-3'-thiacytidine, 3'-azido-3'-deoxythymidine, or 9-(2-phosphonylmethoxyethyl) adenine. Reverse transcriptase purified from DCR-5c was less susceptible to inhibition by ddCTP, phosphonoformic acid, ddATP, or azido-dTTP than the wild-type FIV reverse transcriptase. Sequence analysis of DCR-5c revealed a single base change (G to C at nucleotide 2342) in the reverse transcriptase-encoding region of FIV. This mutation results in substitution of His for Asp at codon 3 of FIV reverse transcriptase. The role of this mutation in ddC resistance was confirmed by site-directed mutagenesis. PMID:8849258
Hartl, Daniel L.
2008-01-01
Simple models of molecular evolution assume that sequences evolve by a Poisson process in which nucleotide or amino acid substitutions occur as rare independent events. In these models, the expected ratio of the variance to the mean of substitution counts equals 1, and substitution processes with a ratio greater than 1 are called overdispersed. Comparing the genomes of 10 closely related species of Drosophila, we extend earlier evidence for overdispersion in amino acid replacements as well as in four-fold synonymous substitutions. The observed deviation from the Poisson expectation can be described as a linear function of the rate at which substitutions occur on a phylogeny, which implies that deviations from the Poisson expectation arise from gene-specific temporal variation in substitution rates. Amino acid sequences show greater temporal variation in substitution rates than do four-fold synonymous sequences. Our findings provide a general phenomenological framework for understanding overdispersion in the molecular clock. Also, the presence of substantial variation in gene-specific substitution rates has broad implications for work in phylogeny reconstruction and evolutionary rate estimation. PMID:18480070
NASA Astrophysics Data System (ADS)
Karľová, Katarína; Strečka, Jozef; Lyra, Marcelo L.
2018-03-01
The spin-1/2 Ising-Heisenberg pentagonal chain is investigated with use of the star-triangle transformation, which establishes a rigorous mapping equivalence with the effective spin-1/2 Ising zigzag ladder. The investigated model has a rich ground-state phase diagram including two spectacular quantum antiferromagnetic ground states with a fourfold broken symmetry. It is demonstrated that these long-period quantum ground states arise due to a competition between the effective next-nearest-neighbor and nearest-neighbor interactions of the corresponding spin-1/2 Ising zigzag ladder. The concurrence is used to quantify the bipartite entanglement between the nearest-neighbor Heisenberg spin pairs, which are quantum-mechanically entangled in two quantum ground states with or without spontaneously broken symmetry. The pair correlation functions between the nearest-neighbor Heisenberg spins as well as the next-nearest-neighbor and nearest-neighbor Ising spins were investigated with the aim to bring insight into how a relevant short-range order manifests itself at low enough temperatures. It is shown that the specific heat displays temperature dependencies with either one or two separate round maxima.
Gyalai-Korpos, Miklós; Mangel, Réka; Alvira, Pablo; Dienes, Dóra; Ballesteros, Mercedes; Réczey, Kati
2011-07-01
Pretreatment is a necessary step in the biomass-to-ethanol conversion process. The side stream of the pretreatment step is the liquid fraction, also referred to as the hydrolyzate, which arises after the separation of the pretreated solid and is composed of valuable carbohydrates along with compounds that are potentially toxic to microbes (mainly furfural, acetic acid, and formic acid). The aim of our study was to utilize the liquid fraction from steam-exploded wheat straw as a carbon source for cellulase production by Trichoderma reesei RUT C30. Results showed that without detoxification, the fungus failed to utilize any dilution of the hydrolyzate; however, after a two-step detoxification process, it was able to grow on a fourfold dilution of the treated liquid fraction. Supplementation of the fourfold-diluted, treated liquid fraction with washed pretreated wheat straw or ground wheat grain led to enhanced cellulase (filter paper) activity. Produced enzymes were tested in hydrolysis of washed pretreated wheat straw. Supplementation with ground wheat grain provided a more efficient enzyme mixture for the hydrolysis by means of the near-doubled β-glucosidase activity obtained.
Epidermal growth factor receptor expression in primary cultured human colorectal carcinoma cells.
Tong, W. M.; Ellinger, A.; Sheinin, Y.; Cross, H. S.
1998-01-01
In situ hybridization on human colon tissue demonstrates that epidermal growth factor receptor (EGFR) mRNA expression is strongly increased during tumour progression. To obtain test systems to evaluate the relevance of growth factor action during carcinogenesis, primary cultures from human colorectal carcinomas were established. EGFR distribution was determined in 2 of the 27 primary cultures and was compared with that in well-defined subclones derived from the Caco-2 cell line, which has the unique property to differentiate spontaneously in vitro in a manner similar to normal enterocytes. The primary carcinoma-derived cells had up to three-fold higher total EGFR levels than the Caco-2 subclones and a basal mitotic rate at least fourfold higher. The EGFR affinity constant is 0.26 nmol l(-1), which is similar to that reported in Caco-2 cells. The proliferation rate of Caco-2 cells is mainly induced by EGF from the basolateral cell surface where the majority of receptors are located, whereas primary cultures are strongly stimulated from the apical side also. This corresponds to a three- to fivefold higher level of EGFR at the apical cell surface. This redistribution of EGFR to apical plasma membranes in advanced colon carcinoma cells suggests that autocrine growth factors in the colon lumen may play a significant role during tumour progression. Images Figure 1 Figure 2 PMID:9667648
Reeves, Aaron A.; Johnson, Marney C.; Vasquez, Margarita M.; Maheshwari, Akhil
2013-01-01
Abstract Objective: This study compared cytokines (in particular transforming growth factor [TGF]-β2) and lactoferrin in maternal human milk (MHM), human-derived milk fortifier (HDMF), and donor human milk (DHM). Materials and Methods: MHM was randomly collected from breastfeeding mothers who had no infectious illness at the time of milk expression. HDMF and DHM were products derived from human milk processed by Holder pasteurization. MHM samples were collected at different times (early/late) and gestations (preterm/term). Lactoferrin was analyzed by western blotting, and cytokines were quantified using commercial enzyme-linked immunosorbent assays. Significance was determined using analysis of variance. Results: In the 164 samples analyzed, TGF-β2 concentrations in HDMF and preterm MHM (at all collection times) were fivefold higher than in DHM (p<0.05). Early preterm MHM had levels of interleukin (IL)-10 and IL-18, 11-fold higher than DHM (p<0.05). IL-6 in DHM was 0.3% of the content found in MHM. IL-18 was fourfold higher in early MHM versus late MHM regardless of gestational age (p<0.05). Lactoferrin concentration in DHM was 6% of that found in MHM. Conclusions: Pasteurization decreases concentrations of most cytokines and lactoferrin in DHM. TGF-β2, a protective intestinal cytokine, has comparable concentrations in HDMF to MHM despite pasteurization. PMID:23869537
Milkovska-Stamenova, Sanja; Hoffmann, Ralf
2017-04-15
Thermal treatment preserves the microbiological safety of milk, but also induces Maillard reactions modifying for example proteins. The purpose of this study was evaluating the influence of consumer behaviors (storage and heating) on protein glycation degrees in bovine milk products. Lactosylation and hexosylation sites were identified in ultra-high temperature (UHT), lactose-free pasteurized, and lactose-free UHT milk (ULF) and infant formula (IF) using tandem mass spectrometry (electron transfer dissociation). Overall, 303 lactosylated and 199 hexosylated peptides were identified corresponding to 170 lactosylation (31 proteins) and 117 hexosylation sites (25 proteins). In quantitative terms, storage increased lactosylation up to fourfold in UHT and IF and hexosylation up to elevenfold in ULF and threefold in IF. These levels increased additionally twofold when the stored samples were heated (40°C). In conclusion, storage and heating appear to influence protein glycation levels in milk at similar or even higher degrees than industrial processing. Copyright © 2016 Elsevier Ltd. All rights reserved.
Graphene versus Multi-Walled Carbon Nanotubes for Electrochemical Glucose Biosensing
Zheng, Dan; Vashist, Sandeep Kumar; Dykas, Michal Marcin; Saha, Surajit; Al-Rubeaan, Khalid; Lam, Edmond; Luong, John H.T.; Sheu, Fwu-Shan
2013-01-01
A simple procedure was developed for the fabrication of electrochemical glucose biosensors using glucose oxidase (GOx), with graphene or multi-walled carbon nanotubes (MWCNTs). Graphene and MWCNTs were dispersed in 0.25% 3-aminopropyltriethoxysilane (APTES) and drop cast on 1% KOH-pre-treated glassy carbon electrodes (GCEs). The EDC (1-ethyl-(3-dimethylaminopropyl) carbodiimide)-activated GOx was then bound covalently on the graphene- or MWCNT-modified GCE. Both the graphene- and MWCNT-based biosensors detected the entire pathophysiological range of blood glucose in humans, 1.4–27.9 mM. However, the direct electron transfer (DET) between GOx and the modified GCE’s surface was only observed for the MWCNT-based biosensor. The MWCNT-based glucose biosensor also provided over a four-fold higher current signal than its graphene counterpart. Several interfering substances, including drug metabolites, provoked negligible interference at pathological levels for both the MWCNT- and graphene-based biosensors. However, the former was more prone to interfering substances and drug metabolites at extremely pathological concentrations than its graphene counterpart. PMID:28809354
Graphene versus Multi-Walled Carbon Nanotubes for Electrochemical Glucose Biosensing.
Zheng, Dan; Vashist, Sandeep Kumar; Dykas, Michal Marcin; Saha, Surajit; Al-Rubeaan, Khalid; Lam, Edmond; Luong, John H T; Sheu, Fwu-Shan
2013-03-14
: A simple procedure was developed for the fabrication of electrochemical glucose biosensors using glucose oxidase (GOx), with graphene or multi-walled carbon nanotubes (MWCNTs). Graphene and MWCNTs were dispersed in 0.25% 3-aminopropyltriethoxysilane (APTES) and drop cast on 1% KOH-pre-treated glassy carbon electrodes (GCEs). The EDC (1-ethyl-(3-dimethylaminopropyl) carbodiimide)-activated GOx was then bound covalently on the graphene- or MWCNT-modified GCE. Both the graphene- and MWCNT-based biosensors detected the entire pathophysiological range of blood glucose in humans, 1.4-27.9 mM. However, the direct electron transfer (DET) between GOx and the modified GCE's surface was only observed for the MWCNT-based biosensor. The MWCNT-based glucose biosensor also provided over a four-fold higher current signal than its graphene counterpart. Several interfering substances, including drug metabolites, provoked negligible interference at pathological levels for both the MWCNT- and graphene-based biosensors. However, the former was more prone to interfering substances and drug metabolites at extremely pathological concentrations than its graphene counterpart.
Precision measurement of neutrino oscillation parameters with KamLAND.
Abe, S; Ebihara, T; Enomoto, S; Furuno, K; Gando, Y; Ichimura, K; Ikeda, H; Inoue, K; Kibe, Y; Kishimoto, Y; Koga, M; Kozlov, A; Minekawa, Y; Mitsui, T; Nakajima, K; Nakajima, K; Nakamura, K; Nakamura, M; Owada, K; Shimizu, I; Shimizu, Y; Shirai, J; Suekane, F; Suzuki, A; Takemoto, Y; Tamae, K; Terashima, A; Watanabe, H; Yonezawa, E; Yoshida, S; Busenitz, J; Classen, T; Grant, C; Keefer, G; Leonard, D S; McKee, D; Piepke, A; Decowski, M P; Detwiler, J A; Freedman, S J; Fujikawa, B K; Gray, F; Guardincerri, E; Hsu, L; Kadel, R; Lendvai, C; Luk, K-B; Murayama, H; O'Donnell, T; Steiner, H M; Winslow, L A; Dwyer, D A; Jillings, C; Mauger, C; McKeown, R D; Vogel, P; Zhang, C; Berger, B E; Lane, C E; Maricic, J; Miletic, T; Batygov, M; Learned, J G; Matsuno, S; Pakvasa, S; Foster, J; Horton-Smith, G A; Tang, A; Dazeley, S; Downum, K E; Gratta, G; Tolich, K; Bugg, W; Efremenko, Y; Kamyshkov, Y; Perevozchikov, O; Karwowski, H J; Markoff, D M; Tornow, W; Heeger, K M; Piquemal, F; Ricol, J-S
2008-06-06
The KamLAND experiment has determined a precise value for the neutrino oscillation parameter Deltam21(2) and stringent constraints on theta12. The exposure to nuclear reactor antineutrinos is increased almost fourfold over previous results to 2.44 x 10(32) proton yr due to longer livetime and an enlarged fiducial volume. An undistorted reactor nu[over]e energy spectrum is now rejected at >5sigma. Analysis of the reactor spectrum above the inverse beta decay energy threshold, and including geoneutrinos, gives a best fit at Deltam21(2)=7.58(-0.13)(+0.14)(stat) -0.15+0.15(syst) x 10(-5) eV2 and tan2theta12=0.56(-0.07)+0.10(stat) -0.06+0.10(syst). Local Deltachi2 minima at higher and lower Deltam21(2) are disfavored at >4sigma. Combining with solar neutrino data, we obtain Deltam21(2)=7.59(-0.21)+0.21 x 10(-5) eV2 and tan2theta12=0.47(-0.05)+0.06.
Antiplasmodial activity of new 4-aminoquinoline derivatives against chloroquine resistant strain.
Sinha, Manish; Dola, Vasanth R; Agarwal, Pooja; Srivastava, Kumkum; Haq, Wahajul; Puri, Sunil K; Katti, Seturam B
2014-07-15
Emergence and spread of multidrug resistant strains of Plasmodium falciparum has severely limited the antimalarial chemotherapeutic options. In order to overcome the obstacle, a set of new side-chain modified 4-aminoquinolines were synthesized and screened against chloroquine-sensitive (3D7) and chloroquine-resistant (K1) strains of P. falciparum. The key feature of the designed molecules is the use of methylpiperazine linked α, β(3)- and γ-amino acids to generate novel side chain modified 4-aminoquinoline analogues. Among the evaluated compounds, 20c and 30 were found more potent than CQ against K1 and displayed a four-fold and a three-fold higher activity respectively, with a good selectivity index (SI=5846 and 11,350). All synthesized compounds had resistance index between 1.06 and >14.13 as against 47.2 for chloroquine. Biophysical studies suggested that this series of compounds act on heme polymerization target. Copyright © 2014 Elsevier Ltd. All rights reserved.
Commercial Driver Medical Examinations
Moffitt, Gary; Hanowski, Richard J.; Kales, Stefanos N.; Porter, Richard J.; Hegmann, Kurt T.
2015-01-01
Objective: The objective of this study was to assess relationships between body mass index (BMI) and comorbid conditions within a large sample of truck drivers. Methods: Commercial driver medical examination data from 88,246 commercial drivers between 2005 and 2012 were analyzed for associations between BMI, medical disorders, and driver certification. Results: Most drivers were obese (53.3%, BMI >30.0 kg/m2) and morbidly obese (26.6%, BMI >35.0 kg/m2), higher than prior reports. Obese drivers were less likely to be certified for 2 years and more likely to report heart disease, hypertension, diabetes mellitus, nervous disorders, sleep disorders, and chronic low back pain (all P < 0.0001). There are relationships between multiple potentially disqualifying conditions and increasing obesity (P < 0.0001). Morbid obesity prevalence increased 8.9% and prevalence of three or more multiple conditions increased fourfold between 2005 and 2012. Conclusions: Obesity is related to multiple medical factors as well as increasing numbers of conditions that limit driving certification. PMID:25710607
NASA Astrophysics Data System (ADS)
Hall, David J.; Han, Sung-Ho; Dugan, Laura
2009-02-01
Reactive oxygen species (ROS) are believed to be involved in many diseases and injuries to the brain, but the molecular processes are not well understood due to a lack of in vivo imaging techniques to evaluate ROS. The fluorescent oxidation products of dihydroethidium (DHE) can monitor ROS production in vivo. Here we demonstrate the novel optical imaging of brain in live mice to measure ROS production via generation of fluorescent DHE oxidation products (ox-DHE) by ROS. We show that in Sod2+/- mice, which have partial loss of a key antioxidant enzyme, superoxide dismutase-2, that ox-DHE fluorescence intensity was significantly higher than in hSOD1 mice, which have four-fold overexpression of superoxide dismutase-1 activity, which had almost no ox-DHE fluorescence, confirming specificity of ox-DHE to ROS production. The DHE oxidation products were also confirmed by detecting a characteristic fluorescence lifetime of the oxidation product, which was validated with ex vivo measurements.
Enhanced carrier multiplication in engineered quasi-type-II quantum dots
Cirloganu, Claudiu M.; Padilha, Lazaro A.; Lin, Qianglu; Makarov, Nikolay S.; Velizhanin, Kirill A.; Luo, Hongmei; Robel, Istvan; Pietryga, Jeffrey M.; Klimov, Victor I.
2014-01-01
One process limiting the performance of solar cells is rapid cooling (thermalization) of hot carriers generated by higher-energy solar photons. In principle, the thermalization losses can be reduced by converting the kinetic energy of energetic carriers into additional electron-hole pairs via carrier multiplication (CM). While being inefficient in bulk semiconductors this process is enhanced in quantum dots, although not sufficiently high to considerably boost the power output of practical devices. Here we demonstrate that thick-shell PbSe/CdSe nanostructures can show almost a fourfold increase in the CM yield over conventional PbSe quantum dots, accompanied by a considerable reduction of the CM threshold. These structures enhance a valence-band CM channel due to effective capture of energetic holes into long-lived shell-localized states. The attainment of the regime of slowed cooling responsible for CM enhancement is indicated by the development of shell-related emission in the visible observed simultaneously with infrared emission from the core. PMID:24938462
Sillanpää, Nora; Koivusalo, Harri
2013-01-01
Despite the crucial role of snow in the hydrological cycle in cold climate conditions, monitoring studies of urban snow quality often lack discussions about the relevance of snow in the catchment-scale runoff management. In this study, measurements of snow quality were conducted at two residential catchments in Espoo, Finland, simultaneously with continuous runoff measurements. The results of the snow quality were used to produce catchment-scale estimates of areal snow mass loads (SML). Based on the results, urbanization reduced areal snow water equivalent but increased pollutant accumulation in snow: SMLs in a medium-density residential catchment were two- to four-fold higher in comparison with a low-density residential catchment. The main sources of pollutants were related to vehicular traffic and road maintenance, but also pet excrement increased concentrations to a high level. Ploughed snow can contain 50% of the areal pollutant mass stored in snow despite its small surface area within a catchment.
NASA Astrophysics Data System (ADS)
Sanders, Christian J.; Eyre, Bradley D.; Santos, Isaac R.; Machado, Wilson; Luiz-Silva, Wanilson; Smoak, Joseph M.; Breithaupt, Joshua L.; Ketterer, Michael E.; Sanders, Luciana; Marotta, Humberto; Silva-Filho, Emmanoel
2014-04-01
The effect of nutrient enrichment on mangrove sediment accretion and carbon accumulation rates is poorly understood. Here we quantify sediment accretion through radionuclide tracers to determine organic carbon (OC), total nitrogen (TN), and total phosphorus (TP) accumulation rates during the previous 60 years in both a nutrient-enriched and a pristine mangrove forest within the same geomorphological region of southeastern Brazil. The forest receiving high nutrient loads has accumulated OC, TN, and TP at rates that are fourfold, twofold, and eightfold respectively, higher than those from the undisturbed mangrove. Organic carbon and TN stable isotopes (δ13C and δ15N) reflect an increased presence of organic matter (OM) originating with either phytoplankton, benthic algae, or another allochthonous source within the more rapidly accumulated sediments of the impacted mangrove. This suggests that the accumulation rate of OM in eutrophic mangrove systems may be enhanced through the addition of autochthonous and allochthonous nonmangrove material.
Thyroid Function and Premature Delivery in TPO Antibody-Negative Women: The Added Value of hCG.
Korevaar, Tim I M; Steegers, Eric A P; Chaker, Layal; Medici, Marco; Jaddoe, Vincent W V; Visser, Theo J; de Rijke, Yolanda B; Peeters, Robin P
2017-09-01
Human chorionic gonadotropin (hCG) stimulates thyroid function during pregnancy. We recently showed that thyroid autoimmunity severely attenuated the thyroidal response to hCG stimulation and that this may underlie the higher risk of premature delivery in thyroperoxidase antibody (TPOAb)-positive women. We hypothesized that a lower thyroidal response to hCG stimulation in TPOAb-negative women is also associated with a higher risk of premature delivery and preterm premature rupture of membranes (pPROM). Thyrotropin (TSH), free thyroxine (FT4), and hCG concentrations were available in 5644 TPOAb-negative women from a prospective cohort. We tested for interaction between TSH or FT4 and hCG in linear regression models for duration of pregnancy and logistic regression models for premature delivery/pPROM. Accordingly, analyses were stratified per TSH percentile (TSH ≥ 85th percentile) and hCG per 10,000 IU/L. Women with high TSH and low hCG concentrations did not have a higher risk of premature delivery or pPROM, with protective effect estimates. In contrast, women with a high TSH concentration despite a high hCG concentration had twofold to 10-fold higher risk of premature delivery (Pdifference = 0.022) and an up to fourfold higher risk of pPROM (Pdifference = 0.079). hCG concentrations were not associated with premature delivery or pPROM. In TPOAb-negative women with high-normal TSH concentrations, only women with high hCG concentrations had a higher risk of premature delivery or pPROM. These results suggest a lower thyroidal response to hCG stimulation is also associated with premature delivery in TPOAb-negative women and that an additional measurement of hCG may improve thyroid-related risk assessments during pregnancy. Copyright © 2017 Endocrine Society
Pelle, Edward; Huang, Xi; Zhang, Qi; Pernodet, Nadine; Yarosh, Daniel B; Frenkel, Krystyna
2014-01-01
The endogenous oxidative state of normal human epidermal melanocytes was investigated and compared to normal human epidermal keratinocytes (NHEKs) in order to gain new insight into melanocyte biology. Previously, we showed that NHEKs contain higher levels of hydrogen peroxide (H2O2) than melanocytes and that it can migrate from NHEKs to melanocytes by passive permeation. Nevertheless, despite lower concentrations of H2O2, we now report higher levels of oxidative DNA in melanocytes as indicated by increased levels of 8-oxo-2'-deoxyguanosine (8-oxo-dG): 4.49 (±0.55 SEM) 8-oxo-dG/10(6) dG compared to 1.49 (±0.11 SEM) 8-oxo-dG/10(6) dG for NHEKs. An antioxidant biomarker, glutathione (GSH), was also lower in melanocytes (3.14 nmoles (±0.15 SEM)/cell) in comparison to NHEKs (5.98 nmoles (±0.33 SEM)/cell). Intriguingly, cellular bioavailable iron as measured in ferritin was found to be nearly fourfold higher in melanocytes than in NHEKs. Further, ferritin levels in melanocytes were also higher than in hepatocarcinoma cells, an iron-rich cell, and it indicates that higher relative iron levels may be characteristic of melanocytes. To account for the increased oxidative DNA and lower GSH and H2O2 levels that we observe, we propose that iron may contribute to higher levels of oxidation by reacting with H2O2 through a Fenton reaction leading to the generation of DNA-reactive hydroxyl radicals. In conclusion, our data support the concept of elevated oxidation and high iron levels as normal parameters of melanocytic activity. We present new evidence that may contribute to our understanding of the melanogenic process and lead to the development of new skin care products.
FIB-4 and imaging for measuring fibrosis in hepatitis C virus.
Turner, Barbara J; Liang, Yuanyuan; Singal, Amit G
2017-02-01
Noninvasive measures are widely used to assess fibrosis and may be used to prioritize hepatitis C virus (HCV) treatment. We examined risks for likely fibrosis in patients with chronic HCV infection using fibrosis-4 (FIB-4) and imaging. A HCV screening program diagnosed chronic HCV in patients born from 1945 to 1965 admitted in a safety net hospital. Likely fibrosis was based on FIB-4 (≥1.45) alone or combined with imaging interpreted as fibrosis or cirrhosis. Logistic regression was used to calculate adjusted odds ratios (AORs) for demographic, clinical, and insurance factors associated with each outcome. Using multiple linear regression among patients with likely fibrosis, we examined associations with higher Model for End-Stage Liver Disease (MELD) scores. Using FIB-4 alone, 57% (83/146) of patients had likely fibrosis versus 43% (63/148) using FIB-4 plus imaging. Obesity/overweight and Hispanic ethnicity had over three-fold to four-fold higher AORs for fibrosis, respectively, based on FIB-4 plus imaging, but both AORs were only two-fold greater with FIB-4 alone. Being uninsured was significantly associated with fibrosis based on FIB-4 alone [AOR=2.40 (95% confidence interval 1.01-5.70)] but not with imaging. Heavy alcohol use and older age were associated with higher AORs of fibrosis with both measures (all P<0.004). MELD scores were ∼3 points higher for uninsured patients, regardless of measure (both P<0.05). Using FIB-4 plus imaging to identify fibrosis in chronic HCV, higher risks are seen for Hispanics and overweight/obese individuals than using FIB-4 alone. Higher MELD scores at diagnosis for the uninsured indicate delayed access to care.
Paradise Threatened: Land Use and Erosion on St. John, US Virgin Islands
Macdonald; Anderson; Dietrich
1997-11-01
/ Rapid development and the concomitant increases in erosion and sedimentation are believed to threaten the reefs and other marine resources that are a primary attraction of St. John and Virgin Islands National Park. Average annual sediment yields from undeveloped areas were estimated from a sediment pond and a mangrove swamp as less than 20 and less than 40 t/km2/yr, respectively. Geomorphic evidence indicates that plantation agriculture during the 18th and 19th centuries did not cause severe erosion. Since about 1950 there has been rapid growth in roads and development due to increasing tourism and second-home development. Our field investigations identified the approximately 50 km of unpaved roads as the primary source of anthropogenic sediment. Field measurements of the road network in two catchments led to the development of a vector-based GIS model to predict road surface erosion and sediment delivery. We estimate that road erosion has caused at least a fourfold increase in island-wide sediment yields and that current sedimentation rates are unprecedented. Paving the dirt roads and implementing standard sediment control practices can greatly reduce current sediment yields and possible adverse effects on the marine ecosystems surrounding St. John.KEY WORDS: Erosion; Sediment yield; Roads; Dry tropics; Development
Nitrogen and the Baltic Sea: managing nitrogen in relation to phosphorus.
Elmgren, R; Larsson, U
2001-10-26
The Baltic is a large, brackish sea (4 x 10(5) km2) extending from 54N to approximately 66N, with a fourfold larger drainage area (population 8 x 10(7). Surface salinity (2 to 8 PSU) and hence biodiversity is low. In the last century, annual nutrient loads increased to 10(6) metric tons N and 5 x 10(4) ton P. Eutrophication is evident in the N-limited south, where cyanobacteria fix 2 to 4 x 10(5) ton N each summer, Secchi depths have been halved, and O2-deficient bottom areas have spread. Production remains low in the P-limited north. In nutrient-enriched coastal areas, phytoplankton blooms, toxic at times, and filamentous macroalgae reduce amenity values. Loads need to be reduced of both N, to reduce production, and P, to limit N-fixing cyanobacterial blooms. When large N-load reductions have been achieved locally, algal biomass has declined. So far, P loads have been reduced more than N loads. If this continues, a P-limited Baltic proper may result, very different from previous N-limited conditions. Reaching the management goal of halved anthropogenic N and P loads at minimum cost will require better understanding of biogeochemical nutrient cycles, economic evaluation of proposed measures, and improved stakeholder participation.
Squid rocket science: How squid launch into air
NASA Astrophysics Data System (ADS)
O'Dor, Ron; Stewart, Julia; Gilly, William; Payne, John; Borges, Teresa Cerveira; Thys, Tierney
2013-10-01
Squid not only swim, they can also fly like rockets, accelerating through the air by forcefully expelling water out of their mantles. Using available lab and field data from four squid species, Sthenoteuthis pteropus, Dosidicus gigas, Illex illecebrosus and Loligo opalescens, including sixteen remarkable photographs of flying S. pteropus off the coast of Brazil, we compared the cost of transport in both water and air and discussed methods of maximizing power output through funnel and mantle constriction. Additionally we found that fin flaps develop at approximately the same size range as flight behaviors in these squids, consistent with previous hypotheses that flaps could function as ailerons whilst aloft. S. pteropus acceleration in air (265 body lengths [BL]/s2; 24.5m/s2) was found to exceed that in water (79BL/s2) three-fold based on estimated mantle length from still photos. Velocities in air (37BL/s; 3.4m/s) exceed those in water (11BL/s) almost four-fold. Given the obvious advantages of this extreme mode of transport, squid flight may in fact be more common than previously thought and potentially employed to reduce migration cost in addition to predation avoidance. Clearly squid flight, the role of fin flaps and funnel, and the energetic benefits are worthy of extended investigation.
Martinez, Victor; Bünger, Lutz; Hill, William G
2000-01-01
Data were analysed from a divergent selection experiment for an indicator of body composition in the mouse, the ratio of gonadal fat pad to body weight (GFPR). Lines were selected for 20 generations for fat (F), lean (L) or were unselected (C), with three replicates of each. Selection was within full-sib families, 16 families per replicate for the first seven generations, eight subsequently. At generation 20, GFPR in the F lines was twice and in the L lines half that of C. A log transformation removed both asymmetry of response and heterogeneity of variance among lines, and so was used throughout. Estimates of genetic variance and heritability (approximately 50%) obtained using REML with an animal model were very similar, whether estimated from the first few generations of selection, or from all 20 generations, or from late generations having fitted pedigree. The estimates were also similar when estimated from selected or control lines. Estimates from REML also agreed with estimates of realised heritability. The results all accord with expectations under the infinitesimal model, despite the four-fold changes in mean. Relaxed selection lines, derived from generation 20, showed little regression in fatness after 40 generations without selection. PMID:14736404
Potent circadian effects of dim illumination at night in hamsters.
Gorman, Michael R; Evans, Jennifer A; Elliott, Jeffrey A
2006-01-01
Conventional wisdom holds that the circadian pacemaker of rodents and humans is minimally responsive to light of the intensity provided by dim moonlight and starlight. However, dim illumination (<0.005 lux) provided during the daily dark periods markedly alters entrainment in hamsters. Under dimly lit scotophases, compared to completely dark ones phases, the upper range of entrainment is increased by approximately 4 h, and re-entrainment is accelerated following transfer from long to short day lengths. Moreover, the incidence of bimodal entrainment to 24 h light:dark:light:dark cycles is increased fourfold. Notably, the nocturnal illumination inducing these pronounced effects is equivalent in photic energy to that of a 2 sec, 100 lux light pulse. These effects may be parsimoniously interpreted as an action of dim light on the phase relations between multiple oscillators comprising the circadian pacemaker. An action of dim light distinct from that underlying bright-light phase-resetting may promote more effective entrainment. Together, the present results refute the view that scotopic illumination is environmental "noise" and indicate that clock function is conspicuously altered by nighttime illumination like that experienced under dim moonlight and starlight. We interpret our results as evidence for a novel action of dim light on the coupling of multiple circadian oscillators.
Nanoparticle-based strategy for personalized B-cell lymphoma therapy
Martucci, Nicola M; Migliaccio, Nunzia; Ruggiero, Immacolata; Albano, Francesco; Calì, Gaetano; Romano, Simona; Terracciano, Monica; Rea, Ilaria; Arcari, Paolo; Lamberti, Annalisa
2016-01-01
B-cell lymphoma is associated with incomplete response to treatment, and the development of effective strategies targeting this disease remains challenging. A new personalized B-cell lymphoma therapy, based on a site-specific receptor-mediated drug delivery system, was developed in this study. Specifically, natural silica-based nanoparticles (diatomite) were modified to actively target the antiapoptotic factor B-cell lymphoma/leukemia 2 (Bcl2) with small interfering RNA (siRNA). An idiotype-specific peptide (Id-peptide) specifically recognized by the hypervariable region of surface immunoglobulin B-cell receptor was exploited as a homing device to ensure specific targeting of lymphoma cells. Specific nanoparticle uptake, driven by the Id-peptide, was evaluated by flow cytometry and confocal microscopy and was increased by approximately threefold in target cells compared with nonspecific myeloma cells and when a random control peptide was used instead of Id-peptide. The specific internalization efficiency was increased by fourfold when siRNA was also added to the modified nanoparticles. The modified diatomite particles were not cytotoxic and their effectiveness in downregulation of gene expression was explored using siRNA targeting Bcl2 and evaluated by quantitative real-time polymerase chain reaction and Western blot analyses. The resulting gene silencing observed is of significant biological importance and opens new possibilities for the personalized treatment of lymphomas. PMID:27895482
Retinal and visual system: occupational and environmental toxicology.
Fox, Donald A
2015-01-01
Occupational chemical exposure often results in sensory systems alterations that occur without other clinical signs or symptoms. Approximately 3000 chemicals are toxic to the retina and central visual system. Their dysfunction can have immediate, long-term, and delayed effects on mental health, physical health, and performance and lead to increased occupational injuries. The aims of this chapter are fourfold. First, provide references on retinal/visual system structure, function, and assessment techniques. Second, discuss the retinal features that make it especially vulnerable to toxic chemicals. Third, review the clinical and corresponding experimental data regarding retinal/visual system deficits produced by occupational toxicants: organic solvents (carbon disulfide, trichloroethylene, tetrachloroethylene, styrene, toluene, and mixtures) and metals (inorganic lead, methyl mercury, and mercury vapor). Fourth, discuss occupational and environmental toxicants as risk factors for late-onset retinal diseases and degeneration. Overall, the toxicants altered color vision, rod- and/or cone-mediated electroretinograms, visual fields, spatial contrast sensitivity, and/or retinal thickness. The findings elucidate the importance of conducting multimodal noninvasive clinical, electrophysiologic, imaging and vision testing to monitor toxicant-exposed workers for possible retinal/visual system alterations. Finally, since the retina is a window into the brain, an increased awareness and understanding of retinal/visual system dysfunction should provide additional insight into acquired neurodegenerative disorders. © 2015 Elsevier B.V. All rights reserved.
Banning, Natasha C.; Maccarone, Linda D.; Fisk, Louise M.; Murphy, Daniel V.
2015-01-01
Ammonia-oxidising archaea (AOA) and bacteria (AOB) are responsible for the rate limiting step in nitrification; a key nitrogen (N) loss pathway in agricultural systems. Dominance of AOA relative to AOB in the amoA gene pool has been reported in many ecosystems, although their relative contributions to nitrification activity are less clear. Here we examined the distribution of AOA and AOB with depth in semi-arid agricultural soils in which soil organic matter content or pH had been altered, and related their distribution to gross nitrification rates. Soil depth had a significant effect on gene abundances, irrespective of management history. Contrary to reports of AOA dominance in soils elsewhere, AOA gene copy numbers were four-fold lower than AOB in the surface (0–10 cm). AOA gene abundance increased with depth while AOB decreased, and sub-soil abundances were approximately equal (10–90 cm). The depth profile of total archaea did not mirror that of AOA, indicating the likely presence of archaea without nitrification capacity in the surface. Gross nitrification rates declined significantly with depth and were positively correlated to AOB but negatively correlated to AOA gene abundances. We conclude that AOB are most likely responsible for regulating nitrification in these semi-arid soils. PMID:26053257
Banning, Natasha C; Maccarone, Linda D; Fisk, Louise M; Murphy, Daniel V
2015-06-08
Ammonia-oxidising archaea (AOA) and bacteria (AOB) are responsible for the rate limiting step in nitrification; a key nitrogen (N) loss pathway in agricultural systems. Dominance of AOA relative to AOB in the amoA gene pool has been reported in many ecosystems, although their relative contributions to nitrification activity are less clear. Here we examined the distribution of AOA and AOB with depth in semi-arid agricultural soils in which soil organic matter content or pH had been altered, and related their distribution to gross nitrification rates. Soil depth had a significant effect on gene abundances, irrespective of management history. Contrary to reports of AOA dominance in soils elsewhere, AOA gene copy numbers were four-fold lower than AOB in the surface (0-10 cm). AOA gene abundance increased with depth while AOB decreased, and sub-soil abundances were approximately equal (10-90 cm). The depth profile of total archaea did not mirror that of AOA, indicating the likely presence of archaea without nitrification capacity in the surface. Gross nitrification rates declined significantly with depth and were positively correlated to AOB but negatively correlated to AOA gene abundances. We conclude that AOB are most likely responsible for regulating nitrification in these semi-arid soils.
Thibodeaux, Julie R; Hanson, Roger G; Rogers, John M; Grey, Brian E; Barbee, Brenda D; Richards, Judy H; Butenhoff, John L; Stevenson, Lisa A; Lau, Christopher
2003-08-01
The maternal and developmental toxicities of perfluorooctane sulfonate (PFOS, C8F17SO3-) were evaluated in the rat and mouse. PFOS is an environmentally persistent compound used as a surfactant and occurs as a degradation product of both perfluorooctane sulfonyl fluoride and substituted perfluorooctane sulfonamido components found in many commercial and consumer applications. Pregnant Sprague-Dawley rats were given 1, 2, 3, 5, or 10 mg/kg PFOS daily by gavage from gestational day (GD) 2 to GD 20; CD-1 mice were similarly treated with 1, 5, 10, 15, and 20 mg/kg PFOS from GD 1 to GD 17. Controls received 0.5% Tween-20 vehicle (1 ml/kg for rats and 10 ml/kg for mice). Maternal weight gain, food and water consumption, and serum chemistry were monitored. Rats were euthanized on GD 21 and mice on GD 18. PFOS levels in maternal serum and in maternal and fetal livers were determined. Maternal weight gains in both species were suppressed by PFOS in a dose-dependent manner, likely attributed to reduced food and water intake. Serum PFOS levels increased with dosage, and liver levels were approximately fourfold higher than serum. Serum thyroxine (T4) and triiodothyronine (T3) in the PFOS-treated rat dams were significantly reduced as early as one week after chemical exposure, although no feedback response of thyroid-stimulating hormone (TSH) was observed. A similar pattern of reduction in T4 was also seen in the pregnant mice. Maternal serum triglycerides were significantly reduced, particularly in the high-dose groups, although cholesterol levels were not affected. In the mouse dams, PFOS produced a marked enlargement of the liver at 10 mg/kg and higher dosages. In the rat fetuses, PFOS was detected in the liver but at levels nearly half of those in the maternal counterparts, regardless of administered doses. In both rodent species, PFOS did not alter the numbers of implantations or live fetuses at term, although small deficits in fetal weight were noted in the rat. A host of birth defects, including cleft palate, anasarca, ventricular septal defect, and enlargement of the right atrium, were seen in both rats and mice, primarily in the 10 and 20 mg/kg dosage groups, respectively. Our results demonstrate both maternal and developmental toxicity of PFOS in the rat and mouse.
Reconstructing dust fluxes and paleoproductivity at the southern Agulhas Plateau since MIS-6
NASA Astrophysics Data System (ADS)
Frenkel, M. M.; Anderson, R. F.; Winckler, G.
2017-12-01
Understanding the mechanisms underlying glacial-interglacial cycles requires characterizing the role of oceanic feedbacks in climatic changes. For example, increased aeolian iron fluxes to Fe-limited regions of the ocean and corresponding changes in marine productivity could have improved biological pump efficiency and resulted in CO2 drawdown. Here we explore these feedbacks using marine sediment core MDO2-2588 collected from the southern Agulhas Plateau (SAP; 41°S, 26°E), located beneath the modern subtropical front. Today, diatom productivity in this region is Si-limited because high Si utilization south of the polar front (PF) means that water advected northward to our study site is Si-depleted. However, previous work has suggested that extended sea ice cover during glacial periods may have limited diatom productivity south of the PF while frontal systems shifted northward, allowing more Si to reach thermocline of the SAP. Meanwhile, increased glacial dust flux to the SAP may have simultaneously supplied more Fe, contributing to higher glacial productivity. This hypothesis has been supported by observations of higher LGM and MIS-6 productivity at MD02-2588 using bulk biogenic content and diatom assemblages (Romero et al., Paleoceanography, 30 (2015) 118-132). Gradients in d13C between benthic and planktic foraminifera have also been used to support Fe fertilization at this site on millennial timescales (Ziegler et al., Nature Geoscience, 6 (2013) 457-461). Yet, studies have yet to produce coordinated records of dust flux and export production for the SAP. Here, we present records of dust, based on 230Th-normalized 232Th fluxes, and export production using 230Th-normalized excess-Ba and opal fluxes and authigenic U through MIS-6. Preliminary results show that lithogenic fluxes to MD02-2588 were approximately twice as high during MIS-6 as MIS-5e and were concurrent with a two-fold increase in excess-Ba flux. However, this relative increase in lithogenic flux during glacials is smaller than the four-fold relative increase in glacial dust flux previously observed in the central South Atlantic (Martínez-García et al., Science, 343 (2014) 1347-1350), motivating future work to study how dust and productivity vary along a zonal transect away from a dust source between glacial and interglacial periods.
Southern forests: Yesterday, today, and tomorrow
R. Neil Sampson
2004-01-01
In the 20th century, southern forests changed dramatically. Those changes pale, however, when compared to what happened to the people of the region. In addition to growing over fourfold in numbers, the South's population has urbanized, globalized, and intellectualized in 100 years. Rural and isolated in the 19th century, they are today urban and cosmopolitan. One...
ERIC Educational Resources Information Center
Walshe, Amanda
2003-01-01
Using an educational ideology and curriculum design perspective, a British initiative to promote nurses' lifelong learning was analyzed. The program creates a clash between romanticist and revisionist ideology. From the perspective of Beattie's fourfold curriculum model, it fails to acknowledge the uniqueness of nursing knowledge, the field's…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Morris, J.R.; Lu, Z.Y.; Xiang, J.B.
We have examined a variety of structures for the (510) symmetric tilt boundary in Si, using first-principles calculations. These calculations show that the observed structure in Si is the lowest energy structure. This structure is more complicated than what is necessary to preserve four-fold coordination. We compare the results to classical and tight-binding models, in order to test these empirical problems.
Continued Steps towards Drug-Free Schools in AISD: 1989-90.
ERIC Educational Resources Information Center
Smyer, Roxane; Wilkinson, David
The Austin (Texas) Independent School District (AISD) has received federal funds through the Drug-Free Schools and Communities Act of 1986. The AISD has established a four-fold approach to educate students in kindergarten through grade 12 about the dangers of drugs and alcohol. The four components of the program include: (1) a core committee…
The Use of Tetrads in the Analysis of Arts-Based Media
ERIC Educational Resources Information Center
Gouzouasis, Peter; LaMonde, Anne-Marie
2005-01-01
In this article, we chose the musical form of a sonata to examine tetrads, a simple four-fold structure that Marshall McLuhan coined and employed to describe various technologies. Tetrads, as cognitive models, are used to refine, focus, or discover entities in cultures and technologies, which are hidden from view in the psyche. Tetradic logic…
Estimating tree species diversity across geographic scales
Susanne Winter; Andreas Böck; Ronald E. McRoberts
2012-01-01
The relationship between number of species and area observed has been described using numerous approaches and has been discussed for more than a century. The general objectives of our study were fourfold: (1) to evaluate the behaviour of species-area curves across geographic scales, (2) to determine sample sizes necessary to produce acceptably precise estimates of tree...
ERIC Educational Resources Information Center
Garcia Lopez, Fatima; Caridad Sebastian, Mercedes; Morales Garcia, Ana Maria
2012-01-01
Introduction: The percentage of foreign-born residents in Spain has multiplied almost fourfold over the last decade. Immigration has changed our society, both from a demographic and economic perspective, and from a cultural and political prospective. The Spanish public library network, a democratic institution that provides services, initially, of…
Forest statistics for North Georgia, 1989
Mark J. Brown; Michael T. Thompson
1989-01-01
Since 1983, area of timberland in North Georgia has decreased by 5 percent and now totals almost 3.0 million acres. Nonindustrial private owners account for two-thirds of the region's timberland. The annual rate of planting experienced a fourfold increase over the previous rate and averaged 22,000 acreas each year. Volume of softwood growing stock fell by 6...
Short-term effects of a high nitrate diet on nitrate metabolism in healthy individuals.
Bondonno, Catherine P; Liu, Alex H; Croft, Kevin D; Ward, Natalie C; Puddey, Ian B; Woodman, Richard J; Hodgson, Jonathan M
2015-03-12
Dietary nitrate, through the enterosalivary nitrate-nitrite-NO pathway, can improve blood pressure and arterial stiffness. How long systemic nitrate and nitrite remain elevated following cessation of high nitrate intake is unknown. In 19 healthy men and women, the time for salivary and plasma nitrate and nitrite to return to baseline after 7 days increased nitrate intake from green leafy vegetables was determined. Salivary and plasma nitrate and nitrite was measured at baseline [D0], end of high nitrate diet [D7], day 9 [+2D], day 14 [+7D] and day 21 [+14D]. Urinary nitrite and nitrate was assessed at D7 and +14D. Increased dietary nitrate for 7 days resulted in a more than fourfold increase in saliva and plasma nitrate and nitrite (p < 0.001) measured at [D7]. At [+2D] plasma nitrite and nitrate had returned to baseline while saliva nitrate and nitrite were more than 1.5 times higher than at baseline levels. By [+7D] all metabolites had returned to baseline levels. The pattern of response was similar between men and women. Urinary nitrate and nitrate was sevenfold higher at D7 compared to +14D. These results suggest that daily ingestion of nitrate may be required to maintain the physiological changes associated with high nitrate intake.
NASA Astrophysics Data System (ADS)
Vendrell-Criado, Victoria; González-Bello, Concepción; Miranda, Miguel A.; Jiménez, M. Consuelo
2018-06-01
Binding of the immunosuppressive agent mycophenolate mofetil (MMP) and its pharmacologically active metabolite mycophenolic acid (MPA) to human serum albumin (HSA) and α1-acid glycoprotein (HAAG) has been investigated by means of an integrated approach involving selective excitation of the drug fluorophore, following their UV-A triggered fluorescence and docking studies. The formation of the protein/ligand complexes was evidenced by a dramatic enhancement of the fluorescence intensity and a hypsochromic shift of the emission band. In HSA, competitive studies using oleic acid as site I probe revealed site I as the main binding site of the ligands. Binding constants revealed that the affinity of the active metabolite by HSA is four-fold higher than its proactive form. Moreover, the affinity of MMP by HSA is three-fold higher than by HAAG. Docking studies revealed significant molecular binding differences in the binding of MMP and MPA to sub-domain IIA of HSA (site 1). For MPA, the aromatic moiety would be in close contact to Trp214 with the flexible chain pointing to the other end of the sub-domain; on the contrary, for MMP, the carboxylate group of the chain would be fixed nearby Trp214 through electrostatic interactions with residues Arg218 and Arg222.
Schwarz, Erika N; Ruhlman, Tracey A; Weng, Mao-Lun; Khiyami, Mohammad A; Sabir, Jamal S M; Hajarah, Nahid H; Alharbi, Njud S; Rabah, Samar O; Jansen, Robert K
2017-04-01
This study represents the most comprehensive plastome-wide comparison of nucleotide substitution rates across the three subfamilies of Fabaceae: Caesalpinioideae, Mimosoideae, and Papilionoideae. Caesalpinioid and mimosoid legumes have large, unrearranged plastomes compared with papilionoids, which exhibit varying levels of rearrangement including the loss of the inverted repeat (IR) in the IR-lacking clade (IRLC). Using 71 genes common to 39 legume taxa representing all the three subfamilies, we show that papilionoids consistently have higher nucleotide substitution rates than caesalpinioids and mimosoids, and rates in the IRLC papilionoids are generally higher than those in the IR-containing papilionoids. Unsurprisingly, this pattern was significantly correlated with growth habit as most papilionoids are herbaceous, whereas caesalpinioids and mimosoids are largely woody. Both nonsynonymous (dN) and synonymous (dS) substitution rates were also correlated with several biological features including plastome size and plastomic rearrangements such as the number of inversions and indels. In agreement with previous reports, we found that genes in the IR exhibit between three and fourfold reductions in the substitution rates relative to genes within the large single-copy or small single-copy regions. Furthermore, former IR genes in IR-lacking taxa exhibit accelerated rates compared with genes contained in the IR.
Diversity of Occupational Orientations in Sales Vocational Education and Training
ERIC Educational Resources Information Center
Reegård, Kaja
2016-01-01
The article examines the ways students in the school-based part of the vocational education and training (VET) in Sales begin to make sense of the world of work they are about to enter. Drawing on a qualitative study of upper-secondary Sales VET students in Norway, a four-fold typology of orientations to retail work is analysed: first, the…
Characteristics of western juniper encroachment into sagebrush communities in central Oregon
Mary M. Rowland; Lowell H. Suring; Robin J. Tausch; Susan Geer; Michael J. Wisdom
2008-01-01
Western juniper (Juniperus occidentalis) woodlands in Oregon have expanded four-fold from 600,000 ha in 1930 to > 2.6 million ha, often resulting in the reduction and fragmentation of sagebrush (Artemisia spp.) communities. We documented dynamics of western juniper across the John Day Ecological Province in central Oregon by recording size class and growth form at...
ERIC Educational Resources Information Center
Rossi Etchelouz, Nelly Yvis
This booklet describes the information and documentation services available within the regional area of the National University of Litoral. The basis and general functions of the service are considered, as well as the organizational and functional structure and subjects given priority in the system. The general functions are fourfold: library…
Trends in Southern pulpwood production, 1953-2006
Tony G. Johnson; Carolyn D. Steppleton; Michael Howell
2008-01-01
Southern pulpwood production has increased nearly fourfold from 16.2 million cords (43.9 million green tons) in 1953 to 64.7 million cords (170.9 million green tons) in 2006. Softwood roundwood production more than doubled in the same time period; however, softwood production expressed as a proportion of the total production has declined from 87 percent in 1953 to 49...
Dynamics of western juniper woodland expansion into sagebrush communities in central Oregon
Mary M. Rowland; Lowell H. Suring; Robin J. Tausch; Susan Greer; Michael J. Wisdom
2011-01-01
Western juniper (Juniperus occidentalis) woodlands in Oregon have expanded four-fold from 600,000 ha in 1930 to > 2.6 million ha, often resulting in the reduction and fragmentation of sagebrush (Artemisia spp.) communities. We documented dynamics of western juniper across the John Day Ecological Province in central Oregon by recording size class and growth form at...
Adult Education of Women for Social Transformation: Reviving the Promise, Continuing the Struggle
ERIC Educational Resources Information Center
Stromquist, Nelly P.
2013-01-01
This chapter considers Theme 4 of the "Hamburg Declaration": Adult learning, gender equality and equity, and the empowerment of women. It has a fourfold purpose. It begins with a review of the balance of progress to date in conceptualizing gender. Second, it examines the objectives of CONFINTEA V and VI from a gender perspective. Third,…
ERIC Educational Resources Information Center
Stevens, Adrian Paul
2010-01-01
Problem Statement. There is a growing need and demand for the "knowledge worker" within the business community. The limited amount of research on the role and impact of public universities suggests the need for addressing the training and workforce development needs of private industry. Purpose. The purpose of this study was fourfold:…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Morris, J.R.; Lu, Z.Y.; Ring, D.M.
The authors have examined a variety of structures for the {l_brace}510{r_brace} symmetric tilt boundary in Si, using first-principles calculations. These calculations show that the observed structure in Si is the lowest energy structure. This structure is more complicated than what is necessary to preserve four-fold coordination. They compare the results to classical and tight-binding models, in order to test these empirical approaches.
ERIC Educational Resources Information Center
Nunez, Jose Carlos; Gonzalez-Pienda, Julio A.; Gonzalez-Pumariega, Soledad; Roces, Cristina; Alvarez, Luis; Gonzalez, Paloma; Cabanach, Ramon G.; Valle, Antonio; Rodriguez, Susana
2005-01-01
The aim of this article was fourfold: first, to determine whether there are significant differences between students with (N=173) and without learning disabilities (LD; N=172) in the dimensions of self-concept, causal attributions, and academic goals. Second, to determine whether students with LD present a uniform attributional profile or whether…
Reproduction of exact solutions of Lipkin model by nonlinear higher random-phase approximation
NASA Astrophysics Data System (ADS)
Terasaki, J.; Smetana, A.; Šimkovic, F.; Krivoruchenko, M. I.
2017-10-01
It is shown that the random-phase approximation (RPA) method with its nonlinear higher generalization, which was previously considered as approximation except for a very limited case, reproduces the exact solutions of the Lipkin model. The nonlinear higher RPA is based on an equation nonlinear on eigenvectors and includes many-particle-many-hole components in the creation operator of the excited states. We demonstrate the exact character of solutions analytically for the particle number N = 2 and numerically for N = 8. This finding indicates that the nonlinear higher RPA is equivalent to the exact Schrödinger equation.
Mehrotra, Ateev; Lave, Judith R
2012-09-01
Retail clinics have rapidly become a fixture of the US health care delivery landscape. We studied visits to retail clinics and found that they increased fourfold from 2007 to 2009, with an estimated 5.97 million retail clinic visits in 2009 alone. Compared with retail clinic patients in 2000-06, patients in 2007-09 were more likely to be age sixty-five or older (14.7 percent versus 7.5 percent). Preventive care-in particular, the influenza vaccine-was a larger component of care for patients at retail clinics in 2007-09, compared to patients in 2000-06 (47.5 percent versus 21.8 percent). Across all retail clinic visits, 44.4 percent in 2007-09 were on the weekend or during weekday hours when physician offices are typically closed. The rapid growth of retail clinics makes it clear that they are meeting a patient need. Convenience and after-hours accessibility are possible drivers of this growth. However, retail clinics make up a small share of overall visits in the outpatient setting, which include 117 million visits to emergency departments and 577 million visits to physician offices annually.
2D-crystallization of Rhodococcus 20S proteasome at the liquid-liquid interface
NASA Astrophysics Data System (ADS)
Aoyama, Kazuhiro
1996-10-01
The 2D-crystallization method using the liquid-liquid interface between a aqueous phase (protein solution) and a thin organic liquid (dehydroabietylamine) layer has been applied to the Rhodococcus 20S proteasome. The 20S proteasome is known to be the core complex of the 26S proteasome, which is the central protease of the ubiquitin-dependent pathway. Two types of ordered arrays were obtained, both large enough for high resolution analysis by electron crystallography. The first one had a four-fold symmetry, whereas the second one was found out to be a hexagonally close-packed array. By image analysis based on a real space correlation averaging (CAV) technique, the close-packed array was found to be hexagonally packed, but the molecules had presumably rotational freedom. The four-fold array was found to be a true crystal with p4 symmetry. Lattice constants were a = b = 20.0 nm and α = 90°. The unit cell of this crystal contained two molecules. The diffraction pattern computed from the original picture showed spots up to (4, 5) that corresponds to 3.1 nm resolution. After applying an unbending procedure, the diffraction pattern showed spots extending to 1.8 nm resolution.
NASA Astrophysics Data System (ADS)
Kabiruzzaman, Md; Ahmed, Rezwan; Nakagawa, Takeshi; Mizuno, Seigi
2017-10-01
Coadsorption of two heavy metals, Pb and Bi, on Cu(001) at room temperature has been studied using low energy electron diffraction (LEED). c(4 × 4), c(2 × 2), and c(9√{ 2}×√{ 2}) phases are obtained at different coverages; here, we have determined the best-fit structure of c(4 × 4) phase. This structure can be described as a 1D substitutional chain arrangement of Pb and Bi atoms between the Cu rows along the [110] direction. The unit cell in the two-dimensional (2D) surface consists of one Bi atom, two Pb atoms, and four Cu atoms with one vacancy at the center. The optimal structure parameters demonstrate that Bi atoms are located at fourfold-hollow sites and that Pb atoms are laterally displaced by 0.78 Å from the fourfold-hollow site toward the vacancy. The reasons for the formation of the c(4 × 4) structure upon deposition of Pb and Bi on Cu(001) are discussed in comparison with a similar structure formed by the individual adsorption of Pb on the same substrate.
Mion, Giuliana; Gianferrara, Teresa; Bergamo, Alberta; Gasser, Gilles; Pierroz, Vanessa; Rubbiani, Riccardo; Vilar, Ramon; Leczkowska, Anna; Alessio, Enzo
2015-11-01
In the search for alternative photosensitizers for use in photodynamic therapy (PDT), herein we describe two new water-soluble porphyrins, a neutral fourfold-symmetric compound and a +3-charged tris-methylpyridinium derivative, in which either four or one [1,4,7]-triazacyclononane (TACN) units are connected to the porphyrin macrocycle through a hydrophilic linker; we also report their corresponding tetracationic Re(I) conjugates. The in vitro (photo)toxic effects of the compounds toward the human cell lines HeLa (cervical cancer), H460M2 (non-small-cell lung carcinoma), and HBL-100 (non-tumorigenic epithelial cells) are reported. Three of the compounds are not cytotoxic in the dark up to 100 μm, and the fourfold-symmetric couple revealed very good phototoxic indexes (PIs). The intracellular localization of all derivatives was studied in HeLa cells by confocal fluorescence microscopy. Although low nuclear localization was observed for some of them, it still prompted us to investigate their capacity to bind both quadruplex and duplex DNA; we observed significant selectivity in the tris-methylpyridinium derivatives for G-quadruplex interactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Zhang, Bin; Nardi, Francesco; Hull-Sanders, Helen; Wan, Xuanwu; Liu, Yinghong
2014-01-01
The complete 16,043 bp mitochondrial genome (mitogenome) of Bactrocera minax (Diptera: Tephritidae) has been sequenced. The genome encodes 37 genes usually found in insect mitogenomes. The mitogenome information for B. minax was compared to the homologous sequences of Bactrocera oleae, Bactrocera tryoni, Bactrocera philippinensis, Bactrocera carambolae, Bactrocera papayae, Bactrocera dorsalis, Bactrocera correcta, Bactrocera cucurbitae and Ceratitis capitata. The analysis indicated the structure and organization are typical of, and similar to, the nine closely related species mentioned above, although it contains the lowest genome-wide A+T content (67.3%). Four short intergenic spacers with a high degree of conservation among the nine tephritid species mentioned above and B. minax were observed, which also have clear counterparts in the control regions (CRs). Correlation analysis among these ten tephritid species revealed close positive correlation between the A+T content of zero-fold degenerate sites (P0FD), the ratio of nucleotide substitution frequency at P0FD sites to all degenerate sites (zero-fold degenerate sites, two-fold degenerate sites and four-fold degenerate sites) and amino acid sequence distance (ASD) were found. Further, significant positive correlation was observed between the A+T content of four-fold degenerate sites (P4FD) and the ratio of nucleotide substitution frequency at P4FD sites to all degenerate sites; however, we found significant negative correlation between ASD and the A+T content of P4FD, and the ratio of nucleotide substitution frequency at P4FD sites to all degenerate sites. A higher nucleotide substitution frequency at non-synonymous sites compared to synonymous sites was observed in nad4, the first time that has been observed in an insect mitogenome. A poly(T) stretch at the 5′ end of the CR followed by a [TA(A)]n-like stretch was also found. In addition, a highly conserved G+A-rich sequence block was observed in front of the poly(T) stretch among the ten tephritid species and two tandem repeats were present in the CR. PMID:24964138
Cabral, Vanessa; Luo, Xuan; Junqueira, Elisabete; Costa, Sofia S; Mulhovo, Silva; Duarte, Aida; Couto, Isabel; Viveiros, Miguel; Ferreira, Maria-José U
2015-04-15
Six compounds (1-6), isolated from the methanol extract of the roots of the African medicinal plant Zanthoxylum capense Thunb. (Rutaceae), and seven ester derivatives (7-13) were evaluated for their antibacterial activities and modulatory effects on the MIC of antibiotics (erythromycin, oxacillin, and tetracycline) and ethidium bromide (EtBr) against a Staphylococcus aureus reference strain (ATCC 6538). Using the same model, compounds 1-13 were also assessed for their potential as efflux pump inhibitors by a fluorometric assay that measures the accumulation of the broad range efflux pump substrate EtBr. Compounds 8 and 11 were further evaluated for their antibacterial, modulatory and EtBr accumulation effects against four additional S. aureus strains, which included two clinical methicillin-resistant S. aureus (MRSA) strains. Compounds (1-13) have not shown antibacterial activity at the concentration ranges tested. When evaluated against S. aureus ATCC 6538, oxychelerythrine (1) a benzophenanthridine alkaloid, showed the highest modulatory activity enhancing the susceptibility of this strain to all the tested antibiotics from two to four-fold. Ailanthoidiol diacetate (8) and ailanthoidiol di-2-ethylbutanoate (11) were also good modulators when combined with EtBr, increasing the bacteria susceptibility by four and two-fold, respectively. In the EtBr accumulation assay, using ATCC 6538 strain, the phenylpropanoid (+)-ailanthoidiol (6) and most of its ester derivatives (8-11) exhibited higher activity than the positive control verapamil. The highest effects were found for compounds 8 and 11 that also increased the accumulation of EtBr, using S. aureus ATCC 25923 as model. Furthermore, both compounds (8, 11) were able to enhance the ciprofloxacin activity against the MRSA clinical strains tested, causing a reduction of the antibiotic MIC values from two to four-fold. The EtBr accumulation assay revealed that this modulation activity was not due to an inhibition of efflux pumps mechanism. These results suggested that Z. capense constituents may be valuable as leads for restoring antibiotic activity against MRSA strains. Copyright © 2015 Elsevier GmbH. All rights reserved.
Malewiak, M I; Griglio, S; Le Liepvre, X
1985-07-01
The relationship between lipogenesis and ketogenesis and the concentration of malonyl coenzyme A (CoA) was investigated in hepatocytes from adult obese Zucker rats and their lean littermates fed either a control low-fat diet or a high-fat diet (30% lard in weight). With the control diet, lipogenesis--although strongly inhibited in the presence of either 1 mmol/L oleate, 10(-6) mol/L glucagon or 0.1 mmol/L TOFA (a hypolipidemic drug)--remained about fifteen-fold higher in the obese rats than in the lean rats. In contrast, ketogenesis under some conditions (oleate + TOFA) was not significantly lower (30%) as compared with the lean rats. After adaptation to the high-fat diet, lipogenesis was depressed fourfold in the lean rats and ninefold in the obese ones; however its magnitude remained significantly higher in the latter, namely at a value close to that measured in control-fed lean rats. Ketogenesis was comparable in lean and obese rats and much higher in the presence of 1 mmol/L oleate than of 0.3 mmol/L oleate, whereas lipogenesis did not vary with increasing oleate concentration in the medium. Acetyl-CoA carboxylase activity measured in liver homogenates was higher in the obese group, but was stepwise inhibited by increasing concentrations of oleyl-CoA regardless of the diet for both lean and obese rats, thus showing no abnormality of in vitro responsiveness to this inhibitor. With the control diet, hepatocyte malonyl-CoA levels were significantly higher in the obese rats, both in the basal state and after inhibition of lipogenesis by oleate and TOFA.(ABSTRACT TRUNCATED AT 250 WORDS)
Sciskalska, Milena; Zalewska, Marta; Grzelak, Agnieszka; Milnerowicz, Halina
2014-06-01
The aim of the study was to verify if there is any association between exposure to Cu, Zn, Cd, Pb, As and the formation of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), advanced oxidation protein products (AOPP), and whether in this process cigarette smoking plays a role. The investigations were performed in the 352 smelters occupationally exposed to heavy metals and 73 persons of control group. Metals concentration was determined by atomic absorption spectrometry. MDA and AOPP concentrations were determined by spectrophotometric methods. The concentration of 8-OHdG was determined by ELISA method. It was demonstrated an increased Cu concentration in smoking smelters compared to non-smoking control group. It was noted no differences in Zn and Mg concentrations between the examined groups. Pb concentration was more than sixfold higher in the group of smoking smelters and about fivefold higher in the group of non-smoking smelters compared to the control groups (smokers and non-smokers). It was shown that Cd concentration in the blood was nearly fivefold higher in the smoking control group compared to the non-smoking control group and more than threefold higher in the group of smoking smelters compared to non-smoking. It was shown an increased As concentration (more than fourfold) and decreased Ca concentration in both groups of smelters compared to control groups. In groups of smelters (smokers and non-smokers), twofold higher MDA and AOPP concentrations, and AOPP/albumin index compared to control groups (smokers and non-smokers) were shown. Tobacco smoke is the major source of Cd in the blood of smelters. Occupational exposure causes accumulation of Pb in the blood. Occupational exposure to heavy metals causes raise of MDA concentration and causes greater increase in AOPP concentration than tobacco smoke.
Spin dependence of ferroelectric polarization in the double exchange model for manganites
NASA Astrophysics Data System (ADS)
Solovyev, I. V.; Nikolaev, S. A.
2014-11-01
The double exchange (DE) model is systematically applied for studying the coupling between ferroelectric (FE) and magnetic orders in several prototypical types of multiferroic manganites. The model itself was constructed for the magnetically active Mn 3 d bands in the basis of Wannier functions and includes the effect of screened onsite Coulomb interactions in the Hartree-Fock approximation. All model parameters were derived from the first-principles electronic-structure calculations. The essence of our approach for the FE polarization is to use the Berry-phase theory, formulated in terms of occupied Wannier functions, and to evaluate the asymmetric spin-dependent change of these functions in the framework of the DE model. This enables us to quantify the effect of the magnetic symmetry breaking and derive several useful expressions for the electronic polarization P , depending on the relative directions of spins. The spin dependence of P in the DE model is given by the isotropic correlation functions ei.ej between directions of neighboring spins. Despite formal similarity with the magnetostriction mechanism, the magnetoelectric coupling in the proposed DE theory is not related to the magnetically driven FE atomic displacements and can exist even in compounds with the centrosymmetric crystal structure, if the spatial distribution of ei.ej does not respect the inversion symmetry. The proposed theory is applied to the solution of three major problems: (i) the magnetic-state dependence of P in hexagonal manganites, using YMnO3 as an example; (ii) the microscopic relationship between canted ferromagnetism and P in monoclinic BiMnO3; (iii) the origin of FE activity in orthorhombic manganites. Particularly, we will show that for an arbitrary noncollinear magnetic structure, propagating along the orthorhombic b axis and antiferromagnetically coupled along the c axis, the polarization is induced by an inhomogeneous distribution of spins and can be obtained by scaling the one of the E-type antiferromagnetic (AFM) phase with the prefactor depending only on the relative directions of spins and being the measure of this spin inhomogeneity. This picture works equally well for the twofold (HoMnO3) and fourfold (TbMnO3) periodic manganites. The basic difference is that, even despite some spin canting of the relativistic origin and deviation from the collinear E-type AFM alignment, the twofold periodic magnetic structure remains strongly inhomogeneous, which leads to large P . On the contrary, the fourfold periodic magnetic structure can be viewed as a moderately distorted homogeneous spin spiral, which corresponds to much weaker P .
Gut-based antioxidant enzymes in a polyphagous and a graminivorous grasshopper.
Barbehenn, Raymond V
2002-07-01
Graminivorous species of grasshoppers develop lethal lesions in their midgut epithelia when they ingest tannic acid, whereas polyphagous grasshoppers are unaffected by ingested tannins. This study tests the hypothesis that polyphagous species are defended by higher activities of antioxidant enzymes (constitutive or inducible) in their guts than are graminivorous species. Comparisons were made between four antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APOX), and glutathione transferase peroxidase (GSTPX). Enzyme activities were measured in the gut lumens and midgut tissues of Melanoplus sanguinipes (polyphagous) and Aulocara ellioti (graminivorous). The results of this study do not support the hypothesis that M. sanguinipes is better defended by antioxidant enzymes than is A. ellioti, nor are these enzymes more inducible in M. sanguinipes than in A. ellioti when insects consume food containing 15% dry weight tannic acid. Instead, tannic acid consumption reduced SOD, APOX, and GSTPX activities in both species. This study reports the first evidence that SOD is secreted into the midgut lumen in insects, with activities two- to fourfold higher than those found in midgut tissues. The spatial distribution of GSTPX and APOX activities observed in both species suggests that ingested plant antioxidant enzymes may function as acquired defenses in grasshoppers. In addition, the results of this study permit the first comparison between the antioxidant enzyme defenses of Orthoptera and Lepidoptera. Most notably, grasshoppers have higher SOD activities than caterpillars, but completely lack APOX in their midgut tissues.
2011-01-01
Background Excessive alcohol consumption in underage people is a rising phenomenon. A major proportion of the disease burden and deaths of young people in developed nations is attributable to alcohol abuse. The aim of this study was to investigate social, demographic and environmental factors that may raise the risk of Saturday night drinking and binge drinking among Italian school students. Methods The study was conducted on a sample of 845 Italian underage school students, by means of an anonymous, self-test questionnaire. Multivariate logistic regression was applied to identify independent risk factors for alcohol drinking and binge drinking. Ordered logistic regression was used to identify independent risk factors for harmful drinking patterns. Results The independent variables that confer a higher risk of drinking in underage students are older age classes, male sex, returning home after midnight, belonging to a group with little respect for the rules, or to a group where young people are not seen as leaders. The higher the perception of alcohol consumption by the group, the higher the risk. Spending time in bars or discos coincides with a two-fold or four-fold increase, respectively, in the risk of alcohol consumption. Conclusion Our findings show that certain environmental and social risk factors are associated with underage drinking. The most important role for preventing young people's exposure to these factors lies with the family, because only parents can exert the necessary control and provide a barrier against potentially harmful situations. PMID:21729273
Gallimberti, Luigi; Chindamo, Sonia; Buja, Alessandra; Forza, Giovanni; Tognazzo, Federica; Galasso, Laura; Vinelli, Angela; Baldo, Vincenzo
2011-07-05
Excessive alcohol consumption in underage people is a rising phenomenon. A major proportion of the disease burden and deaths of young people in developed nations is attributable to alcohol abuse. The aim of this study was to investigate social, demographic and environmental factors that may raise the risk of Saturday night drinking and binge drinking among Italian school students. The study was conducted on a sample of 845 Italian underage school students, by means of an anonymous, self-test questionnaire. Multivariate logistic regression was applied to identify independent risk factors for alcohol drinking and binge drinking. Ordered logistic regression was used to identify independent risk factors for harmful drinking patterns. The independent variables that confer a higher risk of drinking in underage students are older age classes, male sex, returning home after midnight, belonging to a group with little respect for the rules, or to a group where young people are not seen as leaders. The higher the perception of alcohol consumption by the group, the higher the risk. Spending time in bars or discos coincides with a two-fold or four-fold increase, respectively, in the risk of alcohol consumption. Our findings show that certain environmental and social risk factors are associated with underage drinking. The most important role for preventing young people's exposure to these factors lies with the family, because only parents can exert the necessary control and provide a barrier against potentially harmful situations.
Vorstman, Jacob A S; Olde Loohuis, Loes M; Kahn, René S; Ophoff, Roel A
2018-05-14
The co-occurrence of a Copy Number Variant (CNV) and a functional variant on the other allele may be a relevant genetic mechanism in schizophrenia. We hypothesized that the cumulative burden of such double hits - in particular those composed of a deletion and a coding single nucleotide variation (SNV) - is increased in patients with schizophrenia.We combined CNV data with coding variants data in 795 patients with schizophrenia and 474 controls. To limit false CNV-detection, only CNVs called only by two algorithms we included. CNV-affected genes were subsequently examined for coding SNVs, which we termed "CNV-SNVs". Correcting for total queried sequence, we assessed the CNV-SNV-burden and the combined predicted deleterious effect. We estimated p-values by permutation of the phenotype.We detected 105 CNV-SNVs; 67 in duplicated and 38 in deleted genic sequence. While the difference in CNV-SNVs rates was not significant, the combined deleteriousness inferred by CNV-SNVs in deleted sequence was almost fourfold higher in cases compared to controls (nominal p = 0.009). This effect may be driven by a higher number of CNV-SNVs and/or by a higher degree of predicted deleteriousness of CNV-SNVs. No such effect was observed for duplications.We provide early evidence that deletions co-occurring with a functional variant may be relevant, albeit of modest impact, for the genetic etiology of schizophrenia. Large-scale consortium studies are required to validate our findings. Sequence-based analyses would provide the best resolution for detection of CNVs as well as coding variants genome-wide.
Uneven distribution of expressed sequence tag loci on maize pachytene chromosomes
Anderson, Lorinda K.; Lai, Ann; Stack, Stephen M.; Rizzon, Carene; Gaut, Brandon S.
2006-01-01
Examining the relationships among DNA sequence, meiotic recombination, and chromosome structure at a genome-wide scale has been difficult because only a few markers connect genetic linkage maps with physical maps. Here, we have positioned 1195 genetically mapped expressed sequence tag (EST) markers onto the 10 pachytene chromosomes of maize by using a newly developed resource, the RN-cM map. The RN-cM map charts the distribution of crossing over in the form of recombination nodules (RNs) along synaptonemal complexes (SCs, pachytene chromosomes) and allows genetic cM distances to be converted into physical micrometer distances on chromosomes. When this conversion is made, most of the EST markers used in the study are located distally on the chromosomes in euchromatin. ESTs are significantly clustered on chromosomes, even when only euchromatic chromosomal segments are considered. Gene density and recombination rate (as measured by EST and RN frequencies, respectively) are strongly correlated. However, crossover frequencies for telomeric intervals are much higher than was expected from their EST frequencies. For pachytene chromosomes, EST density is about fourfold higher in euchromatin compared with heterochromatin, while DNA density is 1.4 times higher in heterochromatin than in euchromatin. Based on DNA density values and the fraction of pachytene chromosome length that is euchromatic, we estimate that ∼1500 Mbp of the maize genome is in euchromatin. This overview of the organization of the maize genome will be useful in examining genome and chromosome evolution in plants. PMID:16339046
DOE Office of Scientific and Technical Information (OSTI.GOV)
Meharg, A.A.; Shore, R.F.; Broadgate, K.
The toxicity and accumulation of arsenate was determined in the earthworm Lumbricus terrestris in soil from different layers of a forest profile. Toxicity increased fourfold between 2 and 10 d. Edaphic factors (pH, soil organic matter, and depth in soil profile) also affected toxicity with a three fold decrease in the concentration that causes 50% mortality with increasing depth in soil. In a 4-d exposure study, there was no evidence of arsenic bioconcentration in earthworm tissue, although bioaccumulation was occurring. There was a considerable difference in tissue residues between living and dead earthworms, with dead worms having higher concentrations. Thismore » difference was dependent on both soil arsenate concentration and on soil type. Over a wide range of soil arsenate concentrations, earthworm arsenic residues are homeostatically maintained in living worms, but this homeostasis breaks down during death. Alternatively, equilibration with soil residues may occur via accumulation after death. In long-term accumulation studies in soils dosed with a sublethal arsenate concentration, bioconcentration of arsenate did not occur until day 12, after which earthworm concentrations rose steadily above the soil concentration, with residues in worms three fold higher than soil concentrations by the termination of the study. This bioconcentration only occurred in depurated worms over the time period of the study. Initially, depurated worms had lower arsenic concentrations than undepurated until tissue concentrations were equivalent to the soil concentration. Once tissue concentration was greater than soil concentration, depurated worms had higher arsenic residues than undepurated.« less
Huang, Yan-Jun; Jiang, Yun-Bao; Bull, Steven D; Fossey, John S; James, Tony D
2010-11-21
The exciplex formation between a pyridinium boronic acid and phenyl group connected via a propylene linker can be monitored using fluorescence. Addition of pinacol affords a cyclic boronate ester with enhanced Lewis acidity that increases the strength of its cation-π stacking interaction causing a four-fold fluorescence enhancement.
ERIC Educational Resources Information Center
Office of the Special Assistant for the Bicentennial of the United States Constitution (Army), Washington, DC.
The Department of the Army has been chosen to be the executive agent for the Department of Defense (DOD) programs celebrating the Bicentennial of the United States Constitution. The DOD commemorative focus is fourfold: (1) to demonstrate the role and relationships of the military in national government; (2) to provide educational and historical…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wilmot, E.L.; Shirley, C.G.
1982-01-01
Results presented in this paper show that almost any compact binding states into cooperating regions for disposal of LLW will reduce nationwide transportation costs markedly. As a corollary, the reduction of costs may reflect a two- to four-fold reduction of transportation distances with consequent reduction of risk to the public since risk generally decreases directly as transport distances decrease.
Ryan L. Maroney
2006-01-01
The number of protected areas in Mongolia has increased fourfold since the countryâs transition to a market-based economy over a decade ago; however, many of these protected areas have yet to realize their intended role as protectorates of biodiversity. Given the prevalence of (semi-) nomadic pastoralists in rural areas, effective conservation initiatives in Mongolia...
Fourfold Diels-Alder reaction of tetraethynylsilane.
Geyer, Florian L; Rode, Alexander; Bunz, Uwe H F
2014-12-08
A series of ethynylated silanes, including tetraethynylsilane, was treated with tetraphenylcyclopentadienone at 300 °C under microwave irradiation to give the aromatized Diels-Alder adducts as sterically encumbered mini-dendrimers with up to 20 benzene rings. The sterically most congested adducts display red-shifted emission through intramolecular π-π interactions in the excited state. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
P. Thangavel; Stephanie Long; Rakesh Minocha
2007-01-01
Cell suspension cultures of red spruce (Picea rubens Sarg.) were selected to study the effects of cadmium (Cd) and zinc (Zn) on phytochelatins (PCs) and related metabolites after 24 h exposure. The PC2 and its precursor, γ-glutamylcysteine (γ-EC) increased two to fourfold with Cd concentrations ranging from 12...
Chamberlain, Catherine R; Oldenburg, Brian; Wilson, Alyce N; Eades, Sandra J; O'Dea, Kerin; Oats, Jeremy J N; Wolfe, Rory
2016-02-01
Gestational diabetes is associated with a high risk of type 2 diabetes. However, progression rates among Indigenous women in Australia who experience high prevalence of gestational diabetes are unknown. This retrospective cohort study includes all births to women at a regional hospital in Far North Queensland, Australia, coded as having 'gestational diabetes' from 1 January 2004 to 31 December 2010 (1098 births) and receiving laboratory postpartum screening from 1 January 2004 to 31 December 2011 (n = 483 births). Women who did not receive postpartum screening were excluded from the denominator. Data were linked between hospital electronic records, routinely collected birth data and laboratories, with sample validation by reviews of medical records. Analysis was conducted using Cox-proportional regression models. Indigenous women had a greater than fourfold risk of developing type 2 diabetes within 8 years of having gestational diabetes, compared with non-Indigenous women (hazards ratio 4.55, 95% confidence interval 2.63-7.88, p < 0.0001). Among women receiving postpartum screening tests, by 3, 5 and 7 years postpartum, 21.9% (15.8-30.0%), 25.5% (18.6-34.3%) and 42.4% (29.6-58.0%) Indigenous women were diagnosed with type 2 diabetes after gestational diabetes, respectively, compared with 4.2% (2.5-7.2%), 5.7% (3.3-9.5%) and 13.5% (7.3-24.2%) non-Indigenous women. Multivariate analysis showed an increased risk of developing type 2 diabetes among women with an early pregnancy body mass index ≥25 kg/m(2) , only partially breastfeeding at hospital discharge and gestational diabetes diagnosis prior to 17 weeks gestation. This study demonstrates that, compared with non-Indigenous women, Indigenous Australian women have a greater than fourfold risk of developing type 2 diabetes after gestational diabetes. Strategies are urgently needed to reduce rates of type 2 diabetes by supporting a healthy weight and breastfeeding and to improve postpartum screening among Indigenous women with gestational diabetes. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
Quantum Tunneling Symmetry of Single Molecule Magnet Mn_12-acetate
NASA Astrophysics Data System (ADS)
del Barco, E.; Kent, A. D.; Rumberger, E.; Hendrikson, D. N.; Christou, G.
2003-03-01
We have studied the symmetry of magnetic quantum tunneling (MQT) in single crystals of single molecular magnet (SMM) Mn_12-acetate. A superconducting high field vector magnet was used to apply magnetic fields in arbitrary directions respect to the axes of the crystal. The MQT probability is extracted from the change in magnetization measured on sweeping the field through a MQT resonance. This is related to the quantum splitting of the molecules relaxing in the time window of the experiment [1]. The dependence of the MQT probability on the angle between the applied transverse field and the crystallographic axes shows a four-fold rotation pattern, with maxima at angles separated by 90 degrees. By selecting a part of the splitting distribution of the sample by applying an initial transverse field in the direction of one of the observed maxima the situation changes completely. The resulting behavior of the MQT probability shows a two-fold rotation pattern with maxima separated by 180 degrees. Moreover, if the selection is made by applying the initial transverse field in the direction of a complementary four-fold maximum the behavior shows again two-fold symmetry. However, the maxima are found to be shifted by 90 degrees respect to the first selection. The fact that we observe two-fold symmetry for different selections is a clear evidence of the existence of different molecules with lower anisotropy than the imposed by the tetragonal crystallographic site symmetry. The general four-fold symmetry observed is thus due in large part to equal populations of molecules with opposite signs of the second order anisotropy, as suggested by Cornia et al. and appears to be a consequence of to the existence of a discrete set of lower symmetry isomers in a Mn_12-acetate crystal [2]. [1] E. del Barco, A. D. Kent, E. Rumberger, D. N. Hendrikson and G. Christou, Europhys. Lett. 60, 768 (2002) [2] A. Cornia, R. Sessoli, L. Sorace, D. Gatteschi, A. L. Barra and C. Daiguebonne, Phys. Rev. Lett. 89, 257201 (2002)
On-line 3D motion estimation using low resolution MRI
NASA Astrophysics Data System (ADS)
Glitzner, M.; de Senneville, B. Denis; Lagendijk, J. J. W.; Raaymakers, B. W.; Crijns, S. P. M.
2015-08-01
Image processing such as deformable image registration finds its way into radiotherapy as a means to track non-rigid anatomy. With the advent of magnetic resonance imaging (MRI) guided radiotherapy, intrafraction anatomy snapshots become technically feasible. MRI provides the needed tissue signal for high-fidelity image registration. However, acquisitions, especially in 3D, take a considerable amount of time. Pushing towards real-time adaptive radiotherapy, MRI needs to be accelerated without degrading the quality of information. In this paper, we investigate the impact of image resolution on the quality of motion estimations. Potentially, spatially undersampled images yield comparable motion estimations. At the same time, their acquisition times would reduce greatly due to the sparser sampling. In order to substantiate this hypothesis, exemplary 4D datasets of the abdomen were downsampled gradually. Subsequently, spatiotemporal deformations are extracted consistently using the same motion estimation for each downsampled dataset. Errors between the original and the respectively downsampled version of the dataset are then evaluated. Compared to ground-truth, results show high similarity of deformations estimated from downsampled image data. Using a dataset with {{≤ft(2.5 \\text{mm}\\right)}3} voxel size, deformation fields could be recovered well up to a downsampling factor of 2, i.e. {{≤ft(5 \\text{mm}\\right)}3} . In a therapy guidance scenario MRI, imaging speed could accordingly increase approximately fourfold, with acceptable loss of estimated motion quality.
Imaging the effects of individual zinc impurity atoms on superconductivity in Bi2Sr2CaCu2O8+delta
Pan; Hudson; Lang; Eisaki; Uchida; Davis
2000-02-17
Although the crystal structures of the copper oxide high-temperature superconductors are complex and diverse, they all contain some crystal planes consisting of only copper and oxygen atoms in a square lattice: superconductivity is believed to originate from strongly interacting electrons in these CuO2 planes. Substituting a single impurity atom for a copper atom strongly perturbs the surrounding electronic environment and can therefore be used to probe high-temperature superconductivity at the atomic scale. This has provided the motivation for several experimental and theoretical studies. Scanning tunnelling microscopy (STM) is an ideal technique for the study of such effects at the atomic scale, as it has been used very successfully to probe individual impurity atoms in several other systems. Here we use STM to investigate the effects of individual zinc impurity atoms in the high-temperature superconductor Bi2Sr2CaCu2O8+delta. We find intense quasiparticle scattering resonances at the Zn sites, coincident with strong suppression of superconductivity within approximately 15 A of the scattering sites. Imaging of the spatial dependence of the quasiparticle density of states in the vicinity of the impurity atoms reveals the long-sought four-fold symmetric quasiparticle 'cloud' aligned with the nodes of the d-wave superconducting gap which is believed to characterize superconductivity in these materials.
Sand, Jordan M; Aziz, Moammir H; Dreckschmidt, Nancy E; Havighurst, Thomas C; Kim, KyungMann; Oberley, Terry D; Verma, Ajit K
2010-01-01
Chronic exposure to UVR is the major etiologic factor in the development of human skin cancers including squamous-cell carcinoma (SCC). We have previously shown that protein Kinase C epsilon (PKCepsilon) transgenic mice on FVB/N background, which overexpress PKCepsilon protein approximately eightfold over endogenous levels in epidermis, exhibit about threefold more sensitivity than wild-type littermates to UVR-induced development of SCC. To determine whether it is PKCepsilon and not the mouse genetic background that determines susceptibility to UVR carcinogenesis, we cross-bred PKCepsilon FVB/N transgenic mice with SKH-1 hairless mice to generate PKCepsilon-overexpressing SKH-1 hairless mice. To evaluate the susceptibility of PKCepsilon SKH-1 hairless transgenic mice to UVR carcinogenesis, the mice were exposed to UVR (1-2 KJ m(-2)) three times weekly from a bank of six kodacel-filtered FS40 sunlamps. As compared with the wild-type hairless mice, PKCepsilon overexpression in SKH-1 hairless mice decreased the latency (12 weeks), whereas it increased the incidence (twofold) and multiplicity (fourfold) of SCC. The SKH hairless transgenic mice were observed to be as sensitive as FVB/N transgenic mice to UVR-induced development of SCC and expression of proliferative markers (proliferating cell nuclear antigen, signal transducers and activators of transcription 3, and extracellular signal-regulated kinase 1/2). The results indicate that PKCepsilon level dictates susceptibility, irrespective of genetic background, to UVR carcinogenesis.
Recent developments in radiation field control technology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wood, C.J.
1995-03-01
The U.S. nuclear power industry has been remarkably successful in reducing worker radiation exposures over the past ten years. There has been over a fourfold reduction in the person-rem incurred for each MW.year of electric power generated: from 1.8 in 1980, to only 0.39 person-rems in 1991 and 1992. Preliminary data for 1993 are even lower: approximately 0.37 person-rem.MW.year. Despite this substantial improvement, challenges for the industry remain. Individual exposure limits have been tightened in ICRP 60 and there will be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts with be increased requirements for specialmore » maintenance work as plants age, suggesting that vigorous efforts will be required to meet the industry goals for 1995. Reducing out-of-core radiation fields offer the best chance of continuing the downward trend in exposures. To assist utilities select the most economic technology for their specific plants, EPRI has published a manual capturing worldwide operating experience with radiation-field control techniques (TR-100265). No one method will suffice, but implementing suitable combinations from this collection will enable utilities to achieve their exposure goals. Radiation reduction is generally cost-effective: outages are shorter, manpower requirements are reduced and work quality is improved. Despite the up front costs, the benefits over the following 1-3 years typically outweigh the expenses.« less
Schilling, Brian K.; Falvo, Michael J.; Chiu, Loren Z.F.
2008-01-01
The purpose of this brief review is to explain the mechanical relationship between impulse and momentum when resistance exercise is performed in a purposefully slow manner (PS). PS is recognized by ~10s concentric and ~4-10s eccentric actions. While several papers have reviewed the effects of PS, none has yet explained such resistance training in the context of the impulse-momentum relationship. A case study of normal versus PS back squats was also performed. An 85kg man performed both normal speed (3 sec eccentric action and maximal acceleration concentric action) and PS back squats over a several loads. Normal speed back squats produced both greater peak and mean propulsive forces than PS action when measured across all loads. However, TUT was greatly increased in the PS condition, with values fourfold greater than maximal acceleration repetitions. The data and explanation herein point to superior forces produced by the neuromuscular system via traditional speed training indicating a superior modality for inducing neuromuscular adaptation. Key pointsAs velocity approaches zero, propulsive force approaches zero, therefore slow moving objects only require force approximately equal to the weight of the resistance.As mass is constant during resistance training, a greater impulse will result in a greater velocity.The inferior propulsive forces accompanying purposefully slow training suggest other methods of resistance training have a greater potential for adaptation. PMID:24149464
Worrying trends in econophysics
NASA Astrophysics Data System (ADS)
Gallegati, Mauro; Keen, Steve; Lux, Thomas; Ormerod, Paul
2006-10-01
Econophysics has already made a number of important empirical contributions to our understanding of the social and economic world. These fall mainly into the areas of finance and industrial economics, where in each case there is a large amount of reasonably well-defined data. More recently, Econophysics has also begun to tackle other areas of economics where data is much more sparse and much less reliable. In addition, econophysicists have attempted to apply the theoretical approach of statistical physics to try to understand empirical findings. Our concerns are fourfold. First, a lack of awareness of work that has been done within economics itself. Second, resistance to more rigorous and robust statistical methodology. Third, the belief that universal empirical regularities can be found in many areas of economic activity. Fourth, the theoretical models which are being used to explain empirical phenomena. The latter point is of particular concern. Essentially, the models are based upon models of statistical physics in which energy is conserved in exchange processes. There are examples in economics where the principle of conservation may be a reasonable approximation to reality, such as primitive hunter-gatherer societies. But in the industrialised capitalist economies, income is most definitely not conserved. The process of production and not exchange is responsible for this. Models which focus purely on exchange and not on production cannot by definition offer a realistic description of the generation of income in the capitalist, industrialised economies.
Effect of the NEP inhibitor SCH32615 on airway responses to intravenous substance P in guinea pigs.
Shore, S A; Martins, M A; Drazen, J M
1992-11-01
We examined the effects of the selective neutral endopeptidase (NEP) inhibitor SCH32615 on airway responses to rapid intravenous infusions of substance P (SP) and neurokinin A (NKA) and on recovery of administered tachykinins from arterial blood in anesthetized mechanically ventilated guinea pigs. SCH32615, in doses that cause a marked increase in the magnitude of bronchoconstriction induced by infused NKA, had little effect on the changes in pulmonary conductance (GL) or dynamic compliance induced by SP. In animals in which SCH32615 (1 mg/kg) was administered in combination with the angiotensin-converting enzyme (ACE) inhibitor captopril (5.7 mg/kg), the dose of SP required to decrease GL by 50% was fourfold less than in animals that received captopril alone (P < 0.005). SP measured in arterial blood withdrawn within 45 s of intravenous administration of this tachykinin was not different in control and SCH32615-treated animals, whereas captopril caused an approximately threefold increase in SP concentrations (P < 0.005). When SCH32615 and captopril were administered together, significantly more SP was recovered than when captopril or SCH32615 was administered alone (P < 0.0005). Our results are consistent with the hypothesis that both NEP and ACE contribute to the degradation of intravenously infused SP. ACE degradation of SP is sufficient to limit SP-induced bronchoconstriction even in the presence of specific NEP inhibition.
Sato, Hirotoshi; Tanabe, Akifumi S; Toju, Hirokazu
2017-04-01
Mutualisms with new host lineages can provide symbionts with novel ecological opportunities to expand their geographical distribution, thereby leading to evolutionary diversification. Because ectomycorrhizal (ECM) fungi provide ideal opportunities to test the relationship between host shifts and diversification, we tested whether mutualism with new host lineages could increase the diversification rates of ECM fungi. Using a Bayesian tree inferred from 23 027-base nucleotide sequences of 80 single-copy genes, we tested whether the diversification rate had changed through host-shift events in the monophyletic clade containing the ECM fungal genera Strobilomyces and Afroboletus. The results indicated that these fungi were initially associated with Caesalpinioideae/Monotoideae in Africa, acquired associations with Dipterocarpoideae in tropical Asia, and then switched to Fagaceae/Pinaceae and Nothofagaceae/Eucalyptus. Fungal lineages associated with Fagaceae/Pinaceae were inferred to have approximately four-fold and two-fold greater diversification rates than those associated with Caesalpinioideae/Monotoideae and Dipterocarpoideae or Nothofagaceae/Eucalyptus, respectively. Moreover, the diversification rate shift was inferred to follow the host shift to Fagaceae/Pinaceae. Our study suggests that host-shift events, particularly those occurring with respect to Fagaceae/Pinaceae, can provide ecological opportunities for the rapid diversification of Strobilomyces-Afroboletus. Although further studies are needed for generalization, we propose a possible diversification scenario of ECM fungi. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.
An, Shi-Qi; Febrer, Melanie; McCarthy, Yvonne; Tang, Dong-Jie; Clissold, Leah; Kaithakottil, Gemy; Swarbreck, David; Tang, Ji-Liang; Rogers, Jane; Dow, J Maxwell; Ryan, Robert P
2013-01-01
The bacterium Xanthomonas campestris is an economically important pathogen of many crop species and a model for the study of bacterial phytopathogenesis. In X. campestris, a regulatory system mediated by the signal molecule DSF controls virulence to plants. The synthesis and recognition of the DSF signal depends upon different Rpf proteins. DSF signal generation requires RpfF whereas signal perception and transduction depends upon a system comprising the sensor RpfC and regulator RpfG. Here we have addressed the action and role of Rpf/DSF signalling in phytopathogenesis by high-resolution transcriptional analysis coupled to functional genomics. We detected transcripts for many genes that were unidentified by previous computational analysis of the genome sequence. Novel transcribed regions included intergenic transcripts predicted as coding or non-coding as well as those that were antisense to coding sequences. In total, mutation of rpfF, rpfG and rpfC led to alteration in transcript levels (more than fourfold) of approximately 480 genes. The regulatory influence of RpfF and RpfC demonstrated considerable overlap. Contrary to expectation, the regulatory influence of RpfC and RpfG had limited overlap, indicating complexities of the Rpf signalling system. Importantly, functional analysis revealed over 160 new virulence factors within the group of Rpf-regulated genes. PMID:23617851
Karczmarski, Leszek; Huang, Shiang-Lin; Chan, Stephen C Y
2017-02-23
Defining demographic and ecological threshold of population persistence can assist in informing conservation management. We undertook such analyses for the Indo-Pacific humpback dolphin (Sousa chinensis) in the Pearl River Delta (PRD) region, southeast China. We use adult survival estimates for assessments of population status and annual rate of change. Our estimates indicate that, given a stationary population structure and minimal risk scenario, ~2000 individuals (minimum viable population in carrying capacity, MVP k ) can maintain the population persistence across 40 generations. However, under the current population trend (~2.5% decline/annum), the population is fast approaching its viability threshold and may soon face effects of demographic stochasticity. The population demographic trajectory and the minimum area of critical habitat (MACH) that could prevent stochastic extinction are both highly sensitive to fluctuations in adult survival. For a hypothetical stationary population, MACH should approximate 3000-km 2 . However, this estimate increases four-fold with a 5% increase of adult mortality and exceeds the size of PRD when calculated for the current population status. On the other hand, cumulatively all current MPAs within PRD fail to secure the minimum habitat requirement to accommodate sufficiently viable population size. Our findings indicate that the PRD population is deemed to become extinct unless effective conservation measures can rapidly reverse the current population trend.
Bogdanov, A; Janovák, L; Lantos, I; Endrész, V; Sebők, D; Szabó, T; Dékány, I; Deák, J; Rázga, Z; Burián, K; Virok, D P
2017-11-01
Chlamydia trachomatis and herpes simplex virus (HSV) are the most prevalent bacterial and viral sexually transmitted infections. Due to the chronic nature of their infections, they are able to interact with titanium-dioxide (TiO 2 ) nanoparticles (NPs) applied as food additives or drug delivery vehicles. The aim of this study was to describe the interactions of these two prevalent pathogens with the TiO 2 NPs. Chlamydia trachomatis and HSV-2 were treated with nonactivated TiO 2 NPs, silver NPs and silver decorated TiO 2 NPs before infection of HeLa and Vero cells. Their intracellular growth was monitored by quantitative PCR. Unexpectedly, the TiO 2 NPs (100 μg ml -1 ) increased the growth of C. trachomatis by approximately fourfold, while the HSV-2 replication was not affected. Addition of TiO 2 to silver NPs decreased their antimicrobial activity against C. trachomatis up to 27·92-fold. In summary, nonactivated TiO 2 NPs could increase the replication of C. trachomatis and decrease the antimicrobial activity of silver NPs. The food industry or drug delivery use of TiO 2 NPs could enhance the growth of certain intracellular pathogens and potentially worsen disease symptoms, a feature that should be further investigated. © 2017 The Society for Applied Microbiology.
Shen, Xin-Ming; Okuno, Tatsuya; Milone, Margherita; Otsuka, Kenji; Takahashi, Koji; Komaki, Hirofumi; Giles, Elizabeth; Ohno, Kinji; Engel, Andrew G
2016-10-01
We identify two novel mutations in acetylcholine receptor (AChR) causing a slow-channel congenital myasthenia syndrome (CMS) in three unrelated patients (Pts). Pt 1 harbors a heterozygous βV266A mutation (p.Val289Ala) in the second transmembrane domain (M2) of the AChR β subunit (CHRNB1). Pts 2 and 3 carry the same mutation at an equivalent site in the ε subunit (CHRNE), εV265A (p.Val285Ala). The mutant residues are conserved across all AChR subunits of all species and are components of a valine ring in the channel pore, which is positioned four residues above the leucine ring. Both βV266A and εV265A reduce the amino acid size and lengthen the channel opening bursts by fourfold by enhancing gating efficiency by approximately 30-fold. Substitution of alanine for valine at the corresponding position in the δ and α subunit prolongs the burst duration four- and eightfold, respectively. Replacing valine at ε codon 265 either by a still smaller glycine or by a larger leucine also lengthens the burst duration. Our analysis reveals that each valine in the valine ring contributes to channel kinetics equally, and the valine ring has been optimized in the course of evolution to govern channel gating. © 2016 WILEY PERIODICALS, INC.
NASA Astrophysics Data System (ADS)
Davies, D.; Michael, K.; Schmaltz, J. E.; Harrison, S.; Ding, F.; Durbin, P. B.; Boller, R. A.; Cechini, M. F.; Rinsland, P. L.; Ye, G.; Mauoka, E.
2015-12-01
NASA's Land, Atmosphere Near real-time Capability for EOS (Earth Observing System) (LANCE) provides data and imagery approximately 3 hours from satellite observation, to monitor natural events globally and to meet the needs of the near real-time (NRT) applications community. This article describes LANCE, and how the use of NRT data and imagery has evolved. Since 2010 there has been a four-fold increase in both the volume of data and the number of files downloaded. Over the last year there has been a marked shift in the way in which users are accessing NRT imagery; users are gravitating towards Worldview and the Global Imagery Browse Services (GIBS) and away from MODIS Rapid Response, in part due to the increased exposure through social media. In turn this is leading to a broader range of users viewing NASA NRT imagery. This article also describes new, and planned, product enhancements to LANCE. Over the last year, LANCE has expanded to support NRT products from the Advanced Microwave Scanning Radiometer 2 (AMSR2), and the Multi-angle Imaging SpectroRadiometer (MISR). LANCE elements are also planning to ingest and process NRT data from the Visible Infrared Imager Radiometer Suite (VIIRS), and the advanced Ozone Mapping and Profiler Suite (OMPS) instruments onboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite in the near future.
Semiclassical transport in nearly symmetric quantum dots. I. Symmetry breaking in the dot.
Whitney, Robert S; Schomerus, Henning; Kopp, Marten
2009-11-01
We apply the semiclassical theory of transport to quantum dots with exact and approximate spatial symmetries; left-right mirror symmetry, up-down mirror symmetry, inversion symmetry, or fourfold symmetry. In this work-the first of a pair of articles-we consider (a) perfectly symmetric dots and (b) nearly symmetric dots in which the symmetry is broken by the dot's internal dynamics. The second article addresses symmetry-breaking by displacement of the leads. Using semiclassics, we identify the origin of the symmetry-induced interference effects that contribute to weak localization corrections and universal conductance fluctuations. For perfect spatial symmetry, we recover results previously found using the random-matrix theory conjecture. We then go on to show how the results are affected by asymmetries in the dot, magnetic fields, and decoherence. In particular, the symmetry-asymmetry crossover is found to be described by a universal dependence on an asymmetry parameter gamma_{asym} . However, the form of this parameter is very different depending on how the dot is deformed away from spatial symmetry. Symmetry-induced interference effects are completely destroyed when the dot's boundary is globally deformed by less than an electron wavelength. In contrast, these effects are only reduced by a finite amount when a part of the dot's boundary smaller than a lead-width is deformed an arbitrarily large distance.
Yeung, A T; Bascomb, N F; Turner, K J; Schmidt, R R
1981-05-01
By use of a rocket immunoelectrophoresis-activity stain procedure, it was shown that catalytic activity of an ammonium-inducible nicotinamide adenine dinucleotide phosphate-specific glutamate dehydrogenase (NADP-GDH) was accompanied by a coincident increase in enzyme antigen during the cell cycle of preinduced synchronous Chlorella sorokiniana cells growing in the continuous presence of ammonia. Between the fourth and fifth hours of the G-1 phase of the cell cycle, a three- to fourfold increase in linear accumulation of enzyme antigen was observed. Pulse-chase studies with [35S]sulfate, coupled with a specific indirect immunoadsorption procedure for enzyme antigen, showed that NADP-GDH antigen undergoes continuous degradation (i.e., a half-life of 88 to 110 min) during its linear pattern of accumulation during the cell cycle. The apparent half-life of the enzyme increased by approximately 23% of the 4.5-h positive rate change in antigen accumulation during the cell cycle. This increase in half-life is insufficient in itself to account for the large change in rate of NADP-GDH antigen accumulation. The data from immunoelectrophoresis, pulse-chase, and initial 35S incorporation rate experiments taken together support the inference that changes in the rate of NADP-GDH synthesis are primarily responsible for the accumulation patterns of NADP-GDH activity during the C. sorokiniana cell cycle.
NASA Astrophysics Data System (ADS)
Liang, Ying; Fu, Qibin; Wang, Xudong; Liu, Feng; Yang, Gen; Luo, Chunxiong; Ouyang, Qi; Wang, Yugang
2017-03-01
Current knowledge in radiobiology ascribes the adverse biological effects of ionizing radiation primarily to the induction of DNA double-strand breaks (DSBs), which is supposed to be potentially lethal and may be converted to lethal damage due to misrepair. Soft and ultrasoft x-rays have been found to bear elevated biological effectiveness for cell killing compared with conventional x-rays or 60Co γ-rays. This phenomenon is qualitatively interpreted as the increased level of DSB induction for low energy photons, however, a thorough quantitative reasoning is lacking. Here, we systematically compared the relative biological effectiveness (RBE) with relative DSB induction for photons from several hundreds of eV up to MeV. Although there is an approximate two-fold increase in the yields of DSB for low energy photons found in our calculation and a large number of experimental measurements, it is far from enough to account for the three- to four-fold increase in RBE. Further theoretical investigations show that DSB complexity (additional single-strand breaks and base damage within 10 base pairs) increases notably for low energy photons, which largely reconciles the discrepancy between RBE and DSB induction. Our theoretical results are in line with accumulating experimental evidence that complex DSBs are refractory to repair machinery and may contribute predominantly to the formation of lethal damage.
Sequeiros, R C P; Neng, N R; Portugal, F C M; Pinto, M L; Pires, J; Nogueira, J M F
2011-04-01
This work describes the development, validation, and application of a novel methodology for the determination of testosterone and methenolone in urine matrices by stir bar sorptive extraction using polyurethane foams [SBSE(PU)] followed by liquid desorption and high-performance liquid chromatography with diode array detection. The methodology was optimized in terms of extraction time, agitation speed, pH, ionic strength and organic modifier, as well as back-extraction solvent and desorption time. Under optimized experimental conditions, convenient accuracy were achieved with average recoveries of 49.7 8.6% for testosterone and 54.2 ± 4.7% for methenolone. Additionally, the methodology showed good precision (<9%), excellent linear dynamic ranges (>0.9963) and convenient detection limits (0.2-0.3 μg/L). When comparing the efficiency obtained by SBSE(PU) and with the conventional polydimethylsiloxane phase [SBSE(PDMS)], yields up to four-fold higher are attained for the former, under the same experimental conditions. The application of the proposed methodology for the analysis of testosterone and methenolone in urine matrices showed negligible matrix effects and good analytical performance.
NASA Astrophysics Data System (ADS)
Kumar, Astakala Anil; Kumar, Ashok; Quamara, J. K.
2018-02-01
In present study, we report dielectric, ferroelectric and pyroelectric behavior of pristine and La3+ containing barium stannate nanoparticles synthesized via wet chemical route involving cetyltriammonium bromide assisted thermal decomposition of binary precursors. The X-ray diffraction patterns of pristine and La3+ (2, 4 and 6 at%) doped BaSnO3 nanoparticles showed the formation of cubic perovskite phase. On substitution of Ba2+ lattice sites by La3+ at the La content of 6 at%, the sample exhibited fourfold increase in conductivity in comparison to pristine BaSnO3. Polarization hysteresis (P-E) curves of La containing barium stannate nanoparticles showed anti-ferroelectric behavior. The pyroelectric coefficient of pristine and La (2, 4 and 6 at%) containing BaSnO3 nanoparticles at 473 K were found to be 7.8, 11.6, 14.1 and 17.2 μCm-2K-1, respectively. Further, the responsivity and detectivity values were higher in comparison to the materials, such as AlN, GaN, CdS and ZnO.
Liquid impact and fracture of free-standing CVD diamond
NASA Astrophysics Data System (ADS)
Kennedy, Claire F.; Telling, Robert H.; Field, John E.
1999-07-01
The Cavendish Laboratory has developed extensive facilities for studies of liquid and solid particle erosion. This paper describes the high-speed liquid impact erosion of thin CVD diamond discs and the variation with grain sizes of the absolute damage threshold velocity (ADTV), viz., the threshold below which the specimen shows no damage. All specimens fail by rear surface cracking and there is shown to be a shallow dependence of rear surface ADTV on grain size. Fracture propagation in CVD diamond has also been monitored using a specially-designed double-torsion apparatus and data for K1C are presented. Tentatively, the results suggest that finer-grained CVD diamond exhibits a higher fracture toughness, although the differences are slight even over a fourfold variation in the mean grain size. No preference for intergranular fracture was observed and one may conclude from this that the grain boundaries themselves do not seriously weaken the material. The large pre-existing flaws, both within and between grains, whose size varies the grain size are believed to be the dominant source of weakness.
Investigating the strategies for microbial production of trehalose from lignocellulosic sugars.
Wu, Yifei; Wang, Jian; Shen, Xiaolin; Wang, Jia; Chen, Zhenya; Sun, Xinxiao; Yuan, Qipeng; Yan, Yajun
2018-03-01
Trehalose, a multi-functional and value-added disaccharide, can be efficiently biosynthesized from glucose by using a synergetic carbon utilization mechanism (SynCar) which coupled phosphoenolpyruvate (PEP) generation from the second carbon source with PEP-dependent phosphotransferase system (PTS) to promote non-catabolic use of glucose. Considering glucose and xylose present in large amounts in lignocellulosic sugars, we explored new strategies for conversion of both sugars into trehalose. Herein, we first attempted trehalose production from xylose directly, based on which, synergetic utilization of glucose, and xylose prompted by SynCar was implemented in engineered Escherichia coli. As the results, the final titer of trehalose reached 5.55 g/L in shake flask experiments. The conversion ratio or utilization efficiency of glucose or xylose to trehalose was around fourfold higher than that of the original strain (YW-3). This work not only demonstrated the possibility of directly converting xylose (C5 sugar) into trehalose (C12 disaccharide), but also suggested a promising strategy for trehalose production from lignocellulosic sugars for the first time. © 2017 Wiley Periodicals, Inc.
Pushkar, Yulia; Robison, Gregory; Sullivan, Brendan; Fu, Sherleen X; Kohne, Meghan; Jiang, Wendy; Rohr, Sven; Lai, Barry; Marcus, Matthew A; Zakharova, Taisiya; Zheng, Wei
2013-10-01
Analysis of rodent brains with X-ray fluorescence (XRF) microscopy combined with immunohistochemistry allowed us to demonstrate that local Cu concentrations are thousands of times higher in the glia of the subventricular zone (SVZ) than in other cells. Using XRF microscopy with subcellular resolution and intracellular X-ray absorption spectroscopy we determined the copper (I) oxidation state and the sulfur ligand environment. Cu K-edge X-ray absorption near edge spectroscopy is consistent with Cu being bound as a multimetallic Cu-S cluster similar to one present in Cu-metallothionein. Analysis of age-related changes show that Cu content in astrocytes of the SVZ increases fourfold from 3 weeks to 9 months, while Cu concentration in other brain areas remain essentially constant. This increase in Cu correlates with a decrease in adult neurogenesis assessed using the Ki67 marker (both, however, can be age-related effects). We demonstrate that the Cu distribution and age-related concentration changes in the brain are highly cell specific. © 2013 The Anatomical Society and John Wiley & Sons Ltd.
Diuretic downsides--but in low doses they still seem among the best authenticated antihypertensives.
Opie, L H
2000-08-01
Diuretics in low doses have the greatest support among current available antihypertensives in that they have been shown to reduce total mortality, coronary mortality, stroke, and congestive heart failure in an important meta-analysis by Psaty. Recently, Messerli has linked longterm diuretic use to renal cell carcinoma in women. In some patients, diuretic use leads to increasing blood cholesterol and blood sugar levels. Impotence is a recognized side effect, with rates rising about twofold with low-dose chlorthalidone and fourfold with a higher dose. Certain population groups such as younger (<60 years) white males often do not respond to low-dose diuretic therapy with an adequate blood pressure fall. In females of a similar age group, Messerli calculates that prolonged diuretic therapy will prevent only one stroke and no coronary events nor any deaths for every renal cell carcinoma that is provoked. Despite these evident problems, the outcome data on hard endpoints in trials with initial low-dose diuretic therapy remain valid and convincing. Thus, it is argued, low- but not high-dose diuretics retain their primacy in the ranking of antihypertensive therapy.
Watershed responses to Amazon soya bean cropland expansion and intensification.
Neill, Christopher; Coe, Michael T; Riskin, Shelby H; Krusche, Alex V; Elsenbeer, Helmut; Macedo, Marcia N; McHorney, Richard; Lefebvre, Paul; Davidson, Eric A; Scheffler, Raphael; Figueira, Adelaine Michela e Silva; Porder, Stephen; Deegan, Linda A
2013-06-05
The expansion and intensification of soya bean agriculture in southeastern Amazonia can alter watershed hydrology and biogeochemistry by changing the land cover, water balance and nutrient inputs. Several new insights on the responses of watershed hydrology and biogeochemistry to deforestation in Mato Grosso have emerged from recent intensive field campaigns in this region. Because of reduced evapotranspiration, total water export increases threefold to fourfold in soya bean watersheds compared with forest. However, the deep and highly permeable soils on the broad plateaus on which much of the soya bean cultivation has expanded buffer small soya bean watersheds against increased stormflows. Concentrations of nitrate and phosphate do not differ between forest or soya bean watersheds because fixation of phosphorus fertilizer by iron and aluminium oxides and anion exchange of nitrate in deep soils restrict nutrient movement. Despite resistance to biogeochemical change, streams in soya bean watersheds have higher temperatures caused by impoundments and reduction of bordering riparian forest. In larger rivers, increased water flow, current velocities and sediment flux following deforestation can reshape stream morphology, suggesting that cumulative impacts of deforestation in small watersheds will occur at larger scales.
Element-resolved Kikuchi pattern measurements of non-centrosymmetric materials
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vos, Maarten, E-mail: maarten.vos@anu.edu.au
2017-01-15
Angle-resolved electron Rutherford backscattering (ERBS) measurements using an electrostatic electron energy analyser can provide unique access to element-resolved crystallographic information. We present Kikuchi pattern measurements of the non-centrosymmetric crystal GaP, separately resolving the contributions of electrons backscattered from Ga and P. In comparison to element-integrated measurements like in the method of electron backscatter diffraction (EBSD), the effect of the absence of a proper 4-fold rotation axis in the point group of GaP can be sensed with a much higher visibility via the element-resolved Ga to P intensity ratio. These element-resolved measurements make it possible to experimentally attribute the previously observedmore » point-group dependent effect in element-integrated EBSD measurements to the larger contribution of electrons scattered from Ga compared to P. - Highlights: •Element specific Kikuchi patterns are presented for GaP. •Absence of a proper four-fold rotation axis is demonstrated. •Ga and P intensity variations after 90 degree rotation have opposite phase. •The asymmetry in the total intensity distribution resembles that of Ga.« less
Thammapat, Pornpisanu; Meeso, Naret; Siriamornpun, Sirithon
2016-03-01
The impacts of traditional and alternative parboiling processes on the concentrations of fatty acids, tocopherol, tocotrienol, γ-oryzanol and phenolic acids in glutinous rice were investigated. Differences between the two methods were the soaking temperatures and the steaming methods. Results showed that parboiling processes significantly increased the concentrations of saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA), γ-oryzanol, γ-tocotrienol and total phenolic acids (TPA) in glutinous rice, while α-tocopherol, γ-tocopherol and polyunsaturated fatty acids (PUFA) decreased (p<0.05). Both the traditional and alternative parboiling methods increased the levels of γ-oryzanol by three or fourfold compared with the level of γ-oryzanol in raw rice. Parboiling caused both adverse and favorable effects on phenolic acids content (p<0.05). We found that glutinous rice, parboiled using our newly developed method, had higher levels of PUFA, total vitamin E, γ-oryzanol, hydrobenzoic acid, hydroxycinnamic acid and TPA compared to the traditional method. Copyright © 2015 Elsevier Ltd. All rights reserved.
Holland, Hilmar A; Schöne, Bernd R; Marali, Soraya; Jochum, Klaus P
2014-10-15
We present the first annually resolved record of biologically available Pb and Fe in the Greater North Sea and Iceland during 1040-2004 AD based on shells of the long-lived marine bivalve Arctica islandica. The iron content in pre-industrial shells from the North Sea largely remained below the detection limit. Only since 1830, shell Fe levels rose gradually reflecting the combined effect of increased terrestrial runoff of iron-bearing sediments and eutrophication. Although the lead gasoline peak of the 20th century was well recorded by the shells, bivalves that lived during the medieval heyday of metallurgy showed four-fold higher shell Pb levels than modern specimens. Presumably, pre-industrial bivalves were offered larger proportions of resuspended (Pb-enriched) organics, whereas modern specimens receive fresh increased amounts of (Pb-depleted) phytoplankton. As expected, metal loads in the shells from Iceland were much lower. Our study confirms that bivalve shells provide a powerful tool for retrospective environmental biomonitoring. Copyright © 2014 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Du, Libo; Suo, Siqingaowa; Zhang, Han; Jia, Hongying; Liu, Ke Jian; Zhang, Xue Ji; Liu, Yang
2016-11-01
It is still a huge challenge to find a new strategy for rationally designing covalent drugs because most of them are discovered by serendipity. Considering that the effect of covalent drugs is closely associated with the kinetics of the reaction between drug molecule and its target protein, here we first demonstrate an example of the kinetic effect of pi-stacking of drug molecules on covalent antimicrobial drug design. When PEGylated 7-aminocephalosporanic acid (PEG-ACA) is used as a substrate drug, pi-stacking of the ACA group via the self-assembly of PEG-ACA on the surface of gold nanoparticles (i.e. Au@ACA) exhibits antibacterial activity against E. coli fourfold higher than a PEG-ACA monomer does. The reason can be reasonably attributed to the kinetic rate enhancement for the covalent reaction between Au@ACA and penicillin binding proteins. We believe that the self-assembly of functional groups onto the surface of gold nanoparticles represents a new strategy for covalent drug design.
Magnetization reversal modes in fourfold Co nano-wire systems
NASA Astrophysics Data System (ADS)
Blachowicz, T.; Ehrmann, A.
2015-09-01
Magnetic nano-wire systems are, as well as other patterned magnetic structures, of special interest for novel applications, such as magnetic storage media. In these systems, the coupling between neighbouring magnetic units is most important for the magnetization reversal process of the complete system, leading to a variety of magnetization reversal mechanisms. This article examines the influence of the magnetic material on hysteresis loop shape, coercive field, and magnetization reversal modes. While iron nano-wire systems exhibit flat or one-step hysteresis loops, systems consisting of cobalt nano-wires show hysteresis loops with several longitudinal steps and transverse peaks, correlated to a rich spectrum of magnetization reversal mechanisms. We show that changing the material parameters while the system geometry stays identical can lead to completely different hysteresis loops and reversal modes. Thus, especially for finding magnetic nano-systems which can be used as quaternary or even higher-order storage devices, it is rational to test several materials for the planned systems. Apparently, new materials may lead to novel and unexpected behaviour - and can thus result in novel functionalities.
Krutz, L Jason; Shaner, Dale L; Zablotowicz, Robert M
2010-01-01
The aim of this report is to inform modelers of the differences in atrazine fate between s-triazine-adapted and nonadapted soils as a function of depth in the profile and to recommend atrazine and metabolite input values for pesticide process submodules. The objectives of this study were to estimate the atrazine-mineralizing bacterial population, cumulative atrazine mineralization, atrazine persistence, and metabolite (desethylatrazine [DEA], deisopropylatrazine [DIA], and hydroxyatrazine [HA]) formation and degradation in Colorado and Mississippi s-triazine-adapted and nonadapted soils at three depths (0-5, 5-15, and 15-30 cm). Regardless of depth, the AMBP and cumulative atrazine mineralization was at least 3.8-fold higher in s-triazine-adapted than nonadapted soils. Atrazine half-life (T1/2) values pooled over nonadapted soils and depths approximated historic estimates (T1/2 = 60 d). Atrazine persistence in all depths of s-triazine-adapted soils was at least fourfold lower than that of the nonadapted soil. Atrazine metabolite concentrations were lower in s-triazine-adapted than in nonadapted soil by 35 d after incubation regardless of depth. Results indicate that (i) reasonable fate and transport modeling of atrazine will require identifying if soils are adapted to s-triazine herbicides. For example, our data confirm the 60-d T1/2 for atrazine in nonadapted soils, but a default input value of 6 d for atrazine is required for s-triazine adapted soils. (ii) Literature estimates for DEA, DIA, and HA T1/2 values in nonadapted soils are 52, 36, and 60 d, respectively, whereas our analysis indicates that reasonable T1/2 values for s-triazine-adapted soils are 10 d for DEA, 8 d for DIA, and 6 d for HA. (iii) An estimate for the relative distribution of DIA, DEA, and HA produced in nonadapted soils is 18, 72, and 10% of parent, respectively. In s-triazine-adapted soils, the values were 6, 23, and 71% for DIA, DEA, and HA, respectively. The effects of soil adaptation on metabolite distribution need to be confirmed in field experiments.
Kraft, John C; McConnachie, Lisa A; Koehn, Josefin; Kinman, Loren; Collins, Carol; Shen, Danny D; Collier, Ann C; Ho, Rodney J Y
2017-03-27
The aim of the present study was to determine whether a combination of anti-HIV drugs - tenofovir (TFV), lopinavir (LPV) and ritonavir (RTV) - in a lipid-stabilized nanosuspension (called TLC-ART101) could enhance and sustain intracellular drug levels and exposures in lymph node and blood cells above those in plasma. Four macaques were given a single dose of TLC-ART101 subcutaneously. Drug concentrations in plasma and mononuclear cells of the blood (PBMCs) and lymph nodes (LNMCs) were analysed using a validated combination LC-MS/MS assay. For the two active drugs (TFV, LPV), plasma and PBMC intracellular drug levels persisted for over 2 weeks; PBMC drug exposures were three- to four-fold higher than those in plasma. Apparent terminal half-lives (t1/2) of TFV and LPV were 65.3 and 476.9 h in plasma, and 169.1 and 151.2 h in PBMCs. At 24 and 192 h, TFV and LPV drug levels in LNMCs were up to 79-fold higher than those in PBMCs. Analysis of PBMC intracellular TFV and its active metabolite TFV-diphosphate (TFV-DP) indicated that intracellular exposures of total TFV and TFV-DP were markedly higher and persisted longer than in humans and macaques dosed with oral TFV prodrugs, tenofovir disoproxil fumarate (TDF) or tenofovir alafenamide (TAF). A simple, scalable three-drug combination, lipid-stabilized nanosuspension exhibited persistent drug levels in cells of lymph nodes and the blood (HIV host cells) and in plasma. With appropriate dose adjustment, TLC-ART101 may be a useful HIV treatment with a potential to impact residual virus in lymph nodes.
Yoon, Il-Sub; Park, Hyelim; Kwak, Hye-Won; Woo Jung, Yong; Nam, Jae-Hwan
2017-08-24
The level of antibody production induced by a vaccine involves a variety of host factors. One of these, insulin-like growth factor-1 (IGF-1), plays an important role in lymphocyte maturation and antibody expression. Here, we investigated the role of macrophage-derived IGF-1 in the induction of influenza vaccine-specific antibodies using macrophage-derived IGF-1 gene knockout (MIKO) mice. The titers of vaccine-specific total immunoglobulin G (IgG) and IgG1 after immunization were about two- to fourfold lower in MIKO mice than in WT mice. Moreover, MIKO mice showed a relatively weak booster effect of repeated immunization. In contrast, antigen-nonspecific total IgG was about threefold higher in MIKO mice than in WT mice. After viral challenge, the viral titer and the pathological damage in lungs of MIKO mice were higher than those in WT mice despite vaccination. Interestingly, the proportions of proinflammatory immune cells including M1 macrophages, Th1 and Th17 cells was higher in unvaccinated MIKO mice than in unvaccinated WT mice. This suggests that nonspecific activation of immune cells may paradoxically impair the response to the vaccine. In addition, although the proportions of T follicular helper (Tfh) cells and GL-7 + germinal center (GC) B cells were higher in MIKO mice than in WT mice, the population of CD138 + B220 + antibody-secreting plasmablasts was lower in MIKO mice, which may be a cause of the low influenza-specific antibody titer in MIKO mice. Taken together, these results suggest that macrophage-derived IGF-1 might play an important role in the vaccine-triggered immune response by regulating immune cell homeostasis. Copyright © 2017 Elsevier Ltd. All rights reserved.
Histopathological study of perilesional skin in patients diagnosed with nonmelanoma skin cancer.
Apalla, Z; Calzavara-Pinton, P; Lallas, A; Argenziano, G; Kyrgidis, A; Crotti, S; Facchetti, F; Monari, P; Gualdi, G
2016-01-01
Epidemiological and clinical data suggest that actinic damage to the skin is an important predictor of skin carcinogenesis. To investigate the association of squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) with sun-damage alterations seen by histopathology. In the current prospective study, perilesional skin of SCC or BCC lesions was evaluated for presence of alterations associated with chronic photodamage. Presence of scarring, perineural/perivascular invasion, haemorrhage/haemorrhagic crust, ulceration/erosion and margin involvement were also assessed. Of 6038 included lesions, 4523 (74.9%) were BCCs and 1515 (25.1%) were SCCs. Presence of actinic damage was five times more frequent in SCC than in BCC (OR = 5.29, 95% CI 4.44-6.00, P < 0.001), and diagnosis of SCC was twice as common in photo-exposed than nonphoto-exposed body sites (OR = 2.34, 95% CI 2.03-2.70, P < 0.001). There were twofold higher odds for actinic damage in SCC compared with Bowen disease (OR = 2.015, 95% CI 1.55-2.61, P < 0.001). Assessing the different BCC histological subtypes, we found that nodular BCC had at least twofold higher odds (OR = 2.63, 95% CI 2.09-3.32), infiltrative BCC had 48% higher odds (OR = 1.487, 95% CI 1.18-1.87) and basosquamous BCC had fourfold higher odds (OR = 4.10, 95% CI 3.01-5.57) of having actinic damage compared with superficial BCC. Histological verification of ultraviolet-associated alterations in the perilesional skin in patients with NMSC in our study confirms the aetiopathogenic link between sun exposure and epithelial carcinogenesis on a histopathological basis. This correlation was stronger for SCCs than for BCCs. © 2015 British Association of Dermatologists.
Utilization rates of knee-arthroplasty in OECD countries.
Pabinger, C; Lothaller, H; Geissler, A
2015-10-01
The number of knee arthroplasties and the prevalence of obesity are increasing exponentially. To date there have been no published reviews on utilization rates of knee arthroplasty in OECD countries. We analysed economic, medical and population data relating to knee arthroplasty surgeries performed in OECD countries. Gross domestic product (GDP), health expenditures, obesity prevalence, knee arthroplasty utilization rates and growth in knee arthroplasty rates per 100,000 population were assessed for total population, for patients aged 65 years and over, and patients aged 64 years and younger. Obesity prevalence and utilization of knee arthroplasty have increased significantly in the past. The mean utilization rate of knee arthroplasty was 150 (22-235) cases per 100,000 total population in 2011. The strongest annual increase (7%) occurred in patients 64 years and under. Differences between individual countries can be explained by economic and medical patterns, with countries with higher medical expenditures and obesity prevalence having significantly higher utilization rates. Countries with lower utilization rates have significantly higher growth in utilization rates. The future demand for knee prostheses will increase x-fold by 2030, with exact rates dependant upon economic, social and medical factors. We observed a 10-fold variation in the utilization of knee arthroplasty among OECD countries. A significant and strong correlation of GDP, health expenditures and obesity prevalence with utilization of knee arthroplasty was found. Patients aged 64 years and younger show a two-fold higher growth rate in knee arthroplasty compared to the older population. This trend could result in a four-fold demand for knee arthroplasty in OECD countries by 2030. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
Social Licking in Pregnant Dairy Heifers
Tresoldi, Grazyne; Weary, Daniel M.; Pinheiro Machado Filho, Luiz Carlos; von Keyserlingk, Marina A. G.
2015-01-01
Simple Summary Social licking is often associated with good animal welfare, but little is known about this behavior in cattle. Licking behavior was compared in heifers housed indoors versus on pasture. Licking frequency was four-fold higher when heifers were indoors. However, when considering all social interactions recorded (licking and aggressions) licking events represented about 10% of all interactions regardless of housing. This behavior happened more frequently between heifers that were observed more repeatedly in close vicinity of each other. Provision of smaller indoor floor spaces likely brought animals into closer proximity thus facilitating social interactions. Abstract Housing affects social behaviors, such as competition, but little work has addressed affiliative behaviors. This study compared social licking (SL) in pregnant heifers housed indoors (in a free-stall barn) versus outdoors (on pasture), and relationships with competition, feeding and physical proximity to others. Six heifer groups were observed during two six-hour-periods in both treatments. The total number of social events (SL and agonistic interactions) was four times higher when heifers were housed indoors compared to pasture (546 ± 43 vs. 128 ± 7 events/group; P < 0.05). SL as a ratio of the total number of social events was similar in the two treatments (12% vs. 8% of interactions, free-stall and pasture, respectively; P > 0.05). Housing did not affect how the SL bout was initiated and terminated, the duration, the body part licked and behavior preceding licking (P > 0.05). Animals in close proximity showed higher rates of SL (P < 0.0001) but not agonistic interactions (P > 0.05). A previous agonistic event did not predict occurrence or the role of heifers in the following licking event. The higher stocking density indoors likely resulted in increased social interactions. PMID:26610578
ERIC Educational Resources Information Center
Özçelik, Öner; Sprouse, Rex A.
2017-01-01
A significant body of theoretically motivated research has addressed the role of Universal Grammar (UG) in the nonnative acquisition of morphosyntax and properties of the syntax-semantics interface, but very little research has addressed the role of phonological principles of UG in nonnative language acquisition. Turkish has a regular and…
NATO’s Warsaw Summit: In Brief
2016-11-14
Congressional Research Service 9 met the NATO guideline to spend 20% of defense budgets on new equipment and defense modernization and 23 allies spent... budget for FY2017, the Administration requested a fourfold increase in funding for the ERI, primarily to enable “a quicker and more robust response...European allies’ commitment given continued strains on European defense budgets . In addition, some analysts express concern about an apparently growing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xiang, Z.; Lawson, B.; Asaba, T.
The Kondo insulator samarium hexaboride (SmB 6) has been intensely studied in recent years as a potential candidate of a strongly correlated topological insulator. One of the most exciting phenomena observed in SmB 6 is the clear quantum oscillations appearing in magnetic torque at a low temperature despite the insulating behavior in resistance. These quantum oscillations show multiple frequencies and varied effective masses. The origin of quantum oscillation is, however, still under debate with evidence of both two-dimensional Fermi surfaces and three-dimensional Fermi surfaces. Here, we carry out angle-resolved torque magnetometry measurements in a magnetic field up to 45 Tmore » and a temperature range down to 40 mK. With the magnetic field rotated in the (010) plane, the quantum oscillation frequency of the strongest oscillation branch shows a fourfold rotational symmetry. However, in the angular dependence of the amplitude of the same branch, this fourfold symmetry is broken and, instead, a twofold symmetry shows up, which is consistent with the prediction of a two-dimensional Lifshitz-Kosevich model. No deviation of Lifshitz-Kosevich behavior is observed down to 40 mK. Our results suggest the existence of multiple light-mass surface states in SmB 6, with their mobility significantly depending on the surface disorder level.« less
Bulk Rotational Symmetry Breaking in Kondo Insulator SmB 6
Xiang, Z.; Lawson, B.; Asaba, T.; ...
2017-09-25
The Kondo insulator samarium hexaboride (SmB 6) has been intensely studied in recent years as a potential candidate of a strongly correlated topological insulator. One of the most exciting phenomena observed in SmB 6 is the clear quantum oscillations appearing in magnetic torque at a low temperature despite the insulating behavior in resistance. These quantum oscillations show multiple frequencies and varied effective masses. The origin of quantum oscillation is, however, still under debate with evidence of both two-dimensional Fermi surfaces and three-dimensional Fermi surfaces. Here, we carry out angle-resolved torque magnetometry measurements in a magnetic field up to 45 Tmore » and a temperature range down to 40 mK. With the magnetic field rotated in the (010) plane, the quantum oscillation frequency of the strongest oscillation branch shows a fourfold rotational symmetry. However, in the angular dependence of the amplitude of the same branch, this fourfold symmetry is broken and, instead, a twofold symmetry shows up, which is consistent with the prediction of a two-dimensional Lifshitz-Kosevich model. No deviation of Lifshitz-Kosevich behavior is observed down to 40 mK. Our results suggest the existence of multiple light-mass surface states in SmB 6, with their mobility significantly depending on the surface disorder level.« less
Characteristics of the fourth order resonance in high intensity linear accelerators
NASA Astrophysics Data System (ADS)
Jeon, D.; Hwang, Kyung Ryun
2017-06-01
For the 4σ = 360° space-charge resonance in high intensity linear accelerators, the emittance growth is surveyed for input Gaussian beams, as a function of the depressed phase advance per cell σ and the initial tune depression (σo - σ). For each data point, the linac lattice is designed such that the fourth order resonance dominates over the envelope instability. The data show that the maximum emittance growth takes place at σ ≈ 87° over a wide range of the tune depression (or beam current), which confirms that the relevant parameter for the emittance growth is σ and that for the bandwidth is σo - σ. An interesting four-fold phase space structure is observed that cannot be explained with the fourth order resonance terms alone. Analysis attributes this effect to a small negative sixth order detuning term as the beam is redistributed by the resonance. Analytical studies show that the tune increases monotonically for the Gaussian beam which prevents the resonance for σ > 90°. Frequency analysis indicates that the four-fold structure observed for input Kapchinskij-Vladmirskij beams when σ < 90°, is not the fourth order resonance but a fourth order envelope instability because the 1/4 = 90°/360° component is missing in the frequency spectrum.
Alves, Lourdes A; Vitolo, Michele; Felipe, Maria das Graças A; de Almeida e Silva, João Batista
2002-01-01
The sugarcane bagasse hydrolysate, which is rich in xylose, can be used as culture medium for Candida guilliermondii in xylitol production. However, the hydrolysate obtained from bagasse by acid hydrolysis at 120 degrees C for 20 min has by-products (acetic acid and furfural, among others), which are toxic to the yeast over certain concentrations. So, the hydrolysate must be pretreated before using in fermentation. The pretreatment variables considered were: adsorption time (15,37.5, and 60 min), type of acid used (H2So4 and H3Po4), hydrolysate concentration (original, twofold, and fourfold concentrated), and active charcoal (0.5, 1.75 and 3.0%). The suitability of the pretreatment was followed by measuring the xylose reductase (XR) and xylitol dehydrogenase (XD) activity of yeast grown in each treated hydrolysate. The response surface methodology (2(4) full factorial design with a centered face) indicated that the hydrolysate might be concentrated fourfold and the pH adjusted to 7.0 with CaO, followed by reduction to 5.5 with H3PO4. After that it was treated with active charcoal (3.0%) by 60 min. This pretreated hydrolysate attained the high XR/XD ratio of 4.5.
NASA Astrophysics Data System (ADS)
Gehlen, M.; Beck, L.; Calas, G.; Flank, A.-M.; Van Bennekom, A. J.; Van Beusekom, J. E. E.
2002-05-01
We used X-ray absorption spectroscopy at the Al K-edge to investigate the atomic structure of biogenic silica and to assess the effect of Al on its crystal chemistry. Our study provides the first direct evidence for a structural association of Al and Si in biogenic silica. In samples of cultured diatoms, Al is present exclusively in fourfold coordination. The location and relative intensity of X-ray absorption near-edge structure (XANES) features suggests the structural insertion of tetrahedral Al inside the silica framework synthesized by the organism. In diatom samples collected in the marine environment, Al is present in mixed six- and fourfold coordination. The relative intensity of XANES structures indicates the coexistence of structural Al with a clay component, which most likely reflects sample contamination by adhering mineral particles. Extended X-ray absorption fine structure spectroscopy has been used to get Al-O distances in biogenic silica of cultured diatoms, confirming a tetrahedral coordination. Because of its effect on solubility and reaction kinetics of biogenic silica, the structural association between Al and biogenic silica at the stage of biosynthesis has consequences for the use of sedimentary biogenic silica as an indicator of past environmental conditions.
Dermoscopic clues to differentiate facial lentigo maligna from pigmented actinic keratosis.
Lallas, A; Tschandl, P; Kyrgidis, A; Stolz, W; Rabinovitz, H; Cameron, A; Gourhant, J Y; Giacomel, J; Kittler, H; Muir, J; Argenziano, G; Hofmann-Wellenhof, R; Zalaudek, I
2016-05-01
Dermoscopy is limited in differentiating accurately between pigmented lentigo maligna (LM) and pigmented actinic keratosis (PAK). This might be related to the fact that most studies have focused on pigmented criteria only, without considering additional recognizable features. To investigate the diagnostic accuracy of established dermoscopic criteria for pigmented LM and PAK, but including in the evaluation features previously associated with nonpigmented facial actinic keratosis. Retrospectively enrolled cases of histopathologically diagnosed LM, PAK and solar lentigo/early seborrhoeic keratosis (SL/SK) were dermoscopically evaluated for the presence of predefined criteria. Univariate and multivariate regression analyses were performed and receiver operating characteristic curves were used. The study sample consisted of 70 LMs, 56 PAKs and 18 SL/SKs. In a multivariate analysis, the most potent predictors of LM were grey rhomboids (sixfold increased probability of LM), nonevident follicles (fourfold) and intense pigmentation (twofold). In contrast, white circles, scales and red colour were significantly correlated with PAK, posing a 14-fold, eightfold and fourfold probability for PAK, respectively. The absence of evident follicles also represented a frequent LM criterion, characterizing 71% of LMs. White and evident follicles, scales and red colour represent significant diagnostic clues for PAK. Conversely, intense pigmentation and grey rhomboidal lines appear highly suggestive of LM. © 2015 British Association of Dermatologists.
NASA Astrophysics Data System (ADS)
Cuñado, Jose Luis F.; Pedrosa, Javier; Ajejas, Fernando; Perna, Paolo; Miranda, Rodolfo; Camarero, Julio
2017-10-01
Angle- and temperature-dependent vectorial magnetometry measurements are necessary to disentangle the effective magnetic symmetry in magnetic nanostructures. Here we present a detailed study on an Fe(1 0 0) thin film system with competing collinear biaxial (four-fold symmetry) and uniaxial (two-fold) magnetic anisotropies, carried out with our recently developed full angular/broad temperature range/vectorial-resolved magneto-optical Kerr effect magnetometer, named TRISTAN. The data give direct views on the angular and temperature dependence of the magnetization reversal pathways, from which characteristic axes, remanences, critical fields, domain wall types, and effective magnetic symmetry are obtained. In particular, although the remanence shows four-fold angular symmetry for all investigated temperatures (15 K-400 K), the critical fields show strong temperature and angular dependencies and the reversal mechanism changes for specific angles at a given (angle-dependent) critical temperature, showing signatures of an additional collinear two-fold symmetry. This symmetry-breaking is more relevant as temperature increases to room temperature. It originates from the competition between two anisotropy contributions with different symmetry and temperature evolution. The results highlight the importance of combining temperature and angular studies, and the need to look at different magnetic parameters to unravel the underlying magnetic symmetries and temperature evolutions of the symmetry-breaking effects in magnetic nanostructures.
Compensations for increased rotational inertia during human cutting turns.
Qiao, Mu; Brown, Brian; Jindrich, Devin L
2014-02-01
Locomotion in a complex environment is often not steady state, but unsteady locomotion (stability and maneuverability) is not well understood. We investigated the strategies used by humans to perform sidestep cutting turns when running. Previous studies have argued that because humans have small yaw rotational moments of inertia relative to body mass, deceleratory forces in the initial velocity direction that occur during the turning step, or 'braking' forces, could function to prevent body over-rotation during turns. We tested this hypothesis by increasing body rotational inertia and testing whether braking forces during stance decreased. We recorded ground reaction force and body kinematics from seven participants performing 45 deg sidestep cutting turns and straight running at five levels of body rotational inertia, with increases up to fourfold. Contrary to our prediction, braking forces remained consistent at different rotational inertias, facilitated by anticipatory changes to body rotational speed. Increasing inertia revealed that the opposing effects of several turning parameters, including rotation due to symmetrical anterior-posterior forces, result in a system that can compensate for fourfold changes in rotational inertia with less than 50% changes to rotational velocity. These results suggest that in submaximal effort turning, legged systems may be robust to changes in morphological parameters, and that compensations can involve relatively minor adjustments between steps to change initial stance conditions.
Compensations for increased rotational inertia during human cutting turns
Qiao, Mu; Brown, Brian; Jindrich, Devin L.
2014-01-01
Locomotion in a complex environment is often not steady state, but unsteady locomotion (stability and maneuverability) is not well understood. We investigated the strategies used by humans to perform sidestep cutting turns when running. Previous studies have argued that because humans have small yaw rotational moments of inertia relative to body mass, deceleratory forces in the initial velocity direction that occur during the turning step, or ‘braking’ forces, could function to prevent body over-rotation during turns. We tested this hypothesis by increasing body rotational inertia and testing whether braking forces during stance decreased. We recorded ground reaction force and body kinematics from seven participants performing 45 deg sidestep cutting turns and straight running at five levels of body rotational inertia, with increases up to fourfold. Contrary to our prediction, braking forces remained consistent at different rotational inertias, facilitated by anticipatory changes to body rotational speed. Increasing inertia revealed that the opposing effects of several turning parameters, including rotation due to symmetrical anterior–posterior forces, result in a system that can compensate for fourfold changes in rotational inertia with less than 50% changes to rotational velocity. These results suggest that in submaximal effort turning, legged systems may be robust to changes in morphological parameters, and that compensations can involve relatively minor adjustments between steps to change initial stance conditions. PMID:24115061
Banaś, Walentyna; Sanchez Garcia, Alicia; Banaś, Antoni; Stymne, Sten
2013-06-01
The last step in triacylglycerols (TAG) biosynthesis in oil seeds, the acylation of diacylglycerols (DAG), is catalysed by two types of enzymes: the acyl-CoA:diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT). The relative contribution of these enzymes in the synthesis of TAG has not yet been defined in any plant tissue. In the presented work, microsomal preparations were obtained from sunflower and safflower seeds at different stages of development and used in DGAT and PDAT enzyme assays. The ratio between PDAT and DGAT activity differed dramatically between the two different species. DGAT activities were measured with two different acyl acceptors and assay methods using two different acyl-CoAs, and in all cases the ratio of PDAT to DGAT activity was significantly higher in safflower than sunflower. The sunflower DGAT, measured by both methods, showed significant higher activity with 18:2-CoA than with 18:1-CoA, whereas the opposite specificity was seen with the safflower enzyme. The specificities of PDAT on the other hand, were similar in both species with 18:2-phosphatidylcholine being a better acyl donor than 18:1-PC and with acyl groups at the sn-2 position utilised about fourfold the rate of the sn-1 position. No DAG:DAG transacylase activity could be detected in the microsomal preparations.
Bedrak, E; Harvey, S; Chadwick, A
1981-05-01
Diurnal variations in circulating concentrations of LH, GH, prolactin, corticosterone, oestradiol, progesterone and testosterone were followed in laying and broody White Rock domestic fowl. Throughout the 24 h study prolactin concentrations in serum were consistently (two- to fourfold) higher in broody than in laying birds, in which the prolactin level varied with the light:darkness or ovulatory cycles. Concentrations of GH in serum tended to be lower in broody birds but in both groups were very variable and showed no obvious relationship with either the lighting or ovulatory cycles. Broodiness was also characterized by low LH and gonadal steroid levels and by the absence of preovulatory peaks in the serum concentrations of these hormones. A diurnal rhythm in corticosterone was observed in both the laying and broody birds, with high levels during the period of darkness. Corticosterone concentrations were markedly higher in the broody birds than in laying birds during most of the 24 h study. No diurnal rhythm in the blood haematocrit level was observed in either group, although the level was generally lower in broody birds. This difference, however, was insufficient to account for the lower LH and gonadal steroid levels in the broody birds. The results suggest that prolactin is involved in the initiation or maintenance of broodiness in the fowl and the possibility of an antigonadal role for the hormone is discussed.
Reinke, N B; O'Brien, G M
2006-11-01
Flying-foxes are better able to defend haemoglobin against autoxidation than non-volant mammals such as sheep. When challenged with the common physiological oxidant, hydrogen peroxide, haemolysates of flying-fox red blood cells (RBC) were far less susceptible to methaemoglobin formation than sheep. Challenge with 1-acetyl-2-phenylhydrazine (APH) caused only half as much methaemoglobin formation in flying-fox as in ovine haemolysates. When intact cells were challenged with phenazine methosulfate (PMS), flying-fox RBC partially reversed the oxidant damage, and reduced methaemoglobin from 40 to 20% over 2 h incubation, while ovine methaemoglobin remained at 40%. This reflected flying-fox cells' capacity to replenish GSH fast enough that it did not deplete beyond 50%, while ovine RBC GSH was depleted to around 20%. The greater capacity of flying-foxes to defend haemoglobin against oxidant damage may be explained in part by antioxidant enzymes catalase, superoxide dismutase and cytochrome-b ( 5 ) reductase having two- to four-fold higher activity than in sheep (P < 0.001). Further, their capacity to limit GSH depletion to 50% and reduce methaemoglobin (in the presence of glucose), despite ongoing exposure to PMS may result from having ten-fold higher activity of G6PD and 6PGD than sheep (P < 0.001), indicating the presence of a very efficient pentose phosphate pathway in flying-foxes.
Arulselvan, Palanisamy; El Zowalaty, Mohamed Ezzat; Fakurazi, Sharida; Webster, Thomas J.; Geilich, Benjamin; Hussein, Mohd Zobir
2014-01-01
Tuberculosis is a lethal epidemic, difficult to control disease, claiming thousands of lives every year. We have developed a nanodelivery formulation based on para-aminosalicylic acid (PAS) and zinc layered hydroxide using zinc nitrate salt as a precursor. The developed formulation has a fourfold higher efficacy of PAS against mycobacterium tuberculosis with a minimum inhibitory concentration (MIC) found to be at 1.40 μg/mL compared to the free drug PAS with a MIC of 5.0 μg/mL. The newly developed formulation was also found active against Gram-positive bacteria, Gram-negative bacteria, and Candida albicans. The formulation was also found to be biocompatible with human normal lung cells MRC-5 and mouse fibroblast cells-3T3. The in vitro release of PAS from the formulation was found to be sustained in a human body simulated phosphate buffer saline (PBS) solution at pH values of 7.4 and 4.8. Most importantly the nanocomposite prepared using zinc nitrate salt was advantageous in terms of yield and free from toxic zinc oxide contamination and had higher biocompatibility compared to one prepared using a zinc oxide precursor. In summary, these promising in vitro results are highly encouraging for the continued investigation of para-aminosalicylic acid and zinc layered hydroxide nanocomposites in vivo and eventual preclinical studies. PMID:25050392
Vendrell-Criado, Victoria; González-Bello, Concepción; Miranda, Miguel A; Jiménez, M Consuelo
2018-06-15
Binding of the immunosuppressive agent mycophenolate mofetil (MMP) and its pharmacologically active metabolite mycophenolic acid (MPA) to human serum albumin (HSA) and α 1 -acid glycoprotein (HAAG) has been investigated by means of an integrated approach involving selective excitation of the drug fluorophore, following their UV-A triggered fluorescence and docking studies. The formation of the protein/ligand complexes was evidenced by a dramatic enhancement of the fluorescence intensity and a hypsochromic shift of the emission band. In HSA, competitive studies using oleic acid as site I probe revealed site I as the main binding site of the ligands. Binding constants revealed that the affinity of the active metabolite by HSA is four-fold higher than its proactive form. Moreover, the affinity of MMP by HSA is three-fold higher than by HAAG. Docking studies revealed significant molecular binding differences in the binding of MMP and MPA to sub-domain IIA of HSA (site 1). For MPA, the aromatic moiety would be in close contact to Trp214 with the flexible chain pointing to the other end of the sub-domain; on the contrary, for MMP, the carboxylate group of the chain would be fixed nearby Trp214 through electrostatic interactions with residues Arg218 and Arg222. Copyright © 2018 Elsevier B.V. All rights reserved.
Lindow, Steven; Newman, Karyn; Chatterjee, Subhadeep; Baccari, Clelia; Lavarone, Anthony T; Ionescu, Michael
2014-03-01
The rpfF gene from Xylella fastidiosa, encoding the synthase for diffusible signal factor (DSF), was expressed in 'Freedom' grape to reduce the pathogen's growth and mobility within the plant. Symptoms in such plants were restricted to near the point of inoculation and incidence of disease was two- to fivefold lower than in the parental line. Both the longitudinal and lateral movement of X. fastidiosa in the xylem was also much lower. DSF was detected in both leaves and xylem sap of RpfF-expressing plants using biological sensors, and both 2-Z-tetradecenoic acid, previously identified as a component of X. fastidiosa DSF, and cis-11-methyl-2-dodecenoic acid were detected in xylem sap using electrospray ionization mass spectrometry. A higher proportion of X. fastidiosa cells adhered to xylem vessels of the RpfF-expressing line than parental 'Freedom' plants, reflecting a higher adhesiveness of the pathogen in the presence of DSF. Disease incidence in RpfF-expressing plants in field trials in which plants were either mechanically inoculated with X. fastidiosa or subjected to natural inoculation by sharpshooter vectors was two- to fourfold lower in than that of the parental line. The number of symptomatic leaves on infected shoots was reduced proportionally more than the incidence of infection, reflecting a decreased ability of X. fastidiosa to move within DSF-producing plants.
Emergence of higher order rotational symmetry in the hidden order phase of URu 2Si 2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kanchanavatee, N.; Janoschek, M.; Huang, K.
2016-09-30
Electrical resistivity measurements were performed in this paper as functions of temperature, magnetic field, and angle θ between the magnetic field and the c-axis of a URu 2Si 2 single crystal. The resistivity exhibits a two-fold oscillation as a function of θ at high temperatures, which undergoes a 180°-phase shift (sign change) with decreasing temperature at around 35 K. The hidden order transition is manifested as a minimum in the magnetoresistance and amplitude of the two-fold oscillation. Interestingly, the resistivity also showed four-fold, six-fold, and eight-fold symmetries at the hidden order transition. These higher order symmetries were also detected atmore » low temperatures, which could be a sign of the formation of another pseudogap phase above the superconducting transition, consistent with recent evidence for a pseudogap from point-contact spectroscopy measurements and NMR. Measurements of the magnetisation of single crystalline URu 2Si 2 with the magnetic field applied parallel and perpendicular to the crystallographic c-axis revealed regions with linear temperature dependencies between the hidden order transition temperature and about 25 K. Finally, this T-linear behaviour of the magnetisation may be associated with the formation of a precursor phase or ‘pseudogap’ in the density of states in the vicinity of 30–35 K.« less
Short-Term Effects of a High Nitrate Diet on Nitrate Metabolism in Healthy Individuals
Bondonno, Catherine P.; Liu, Alex H.; Croft, Kevin D.; Ward, Natalie C.; Puddey, Ian B.; Woodman, Richard J.; Hodgson, Jonathan M.
2015-01-01
Dietary nitrate, through the enterosalivary nitrate-nitrite-NO pathway, can improve blood pressure and arterial stiffness. How long systemic nitrate and nitrite remain elevated following cessation of high nitrate intake is unknown. In 19 healthy men and women, the time for salivary and plasma nitrate and nitrite to return to baseline after 7 days increased nitrate intake from green leafy vegetables was determined. Salivary and plasma nitrate and nitrite was measured at baseline [D0], end of high nitrate diet [D7], day 9 [+2D], day 14 [+7D] and day 21 [+14D]. Urinary nitrite and nitrate was assessed at D7 and +14D. Increased dietary nitrate for 7 days resulted in a more than fourfold increase in saliva and plasma nitrate and nitrite (p < 0.001) measured at [D7]. At [+2D] plasma nitrite and nitrate had returned to baseline while saliva nitrate and nitrite were more than 1.5 times higher than at baseline levels. By [+7D] all metabolites had returned to baseline levels. The pattern of response was similar between men and women. Urinary nitrate and nitrate was sevenfold higher at D7 compared to +14D. These results suggest that daily ingestion of nitrate may be required to maintain the physiological changes associated with high nitrate intake. PMID:25774606
Nedvidkova, Jara; Haluzik, Martin; Bartak, Vladimir; Dostalova, Ivana; Vlcek, Petr; Racek, Pavel; Taus, Michal; Behanova, Magdalena; Svacina, Stepan; Alesci, Salvatore; Pacak, Karel
2004-06-01
Thyroid function plays an important role in the regulation of overall metabolic rate and lipid metabolism. However, it is uncertain whether thyroid hormones directly affect lipolysis in adipose tissue and to what extent those changes contribute to overall metabolic phenotype. Our study was designed, using the microdialysis technique, to determine basal and isoprenaline-stimulated local lipolysis and to determine local concentrations of lipolysis-regulating catecholamines in abdominal subcutaneous adipose tissue in 12 patients with hypothyroidism, 6 patients with hyperthyroidism, and 12 healthy control subjects. Plasma norepinephrine (NE) concentrations in hypothyroid subjects were significantly higher than in the control and hyperthyroid groups. In contrast, systemic, adipose NE levels in hypothyroid patients were decreased relative to controls. Hyperthyroidism, on the other hand, resulted in four-fold higher adipose NE levels. Basal lipolysis measured by glycerol concentrations in adipose tissue was significantly attenuated in hypothyroid patients and markedly increased in hyperthyroid patients in comparison with the control group. In addition to differences in basal lipolysis, hypothyroidism resulted in attenuated, and hyperthyroidism in enhanced, lipolytic response to local stimulation with beta(1,2)-adrenergic agonist isoprenaline. These results demonstrate that lipolysis in abdominal subcutaneous adipose tissue is strongly modulated by thyroid function. We suggest that thyroid hormones regulate lipolysis primarily by affecting local NE concentration and/or adrenergic postreceptor signaling.
Printza, Nikoleta; Farmaki, Evagelia; Bosdou, Julia; Gkogka, Chrysa; Papachristou, Fotios
2010-10-01
We aimed to evaluate the acceptance of pandemic influenza A 2009 vaccination in our high risk children with chronic renal diseases. A total of 64 children/parents of pediatric nephrology department were approached to fill in a standardised questionnaire on influenza immunization profile. The H1N1 vaccination rates were 57.1% for transplant recipients, 61.5% for patients on peritoneal dialysis (PD), 36.4% for patients with various stages of chronic renal disease (CRD) and 26.7% for patients with glomerulonephritis (GN) on immunosuppressive therapy. Children on renal transplantation or PD had a fourfold higher rate of being vaccinated than children with GN (p=0.04). Causes of denying vaccination included fear of adverse effects (48.9%), lack of sufficient data on the new vaccine (31.9%) and others (19.2%). Patients being vaccinated were all urged by their pediatric nephrologist (100%), while patients not vaccinated were negatively influenced by media (41.4%), friends (24.1%), pediatrician (20.7%) and others (13.8%). Regarding parents education, higher level was associated with increased rate of children vaccination (p=0.04). It seems that patients with severe renal disease had better compliance with vaccination. The pediatric nephrologists had the most significant positive influence in contrast to the media which had the most negative influence.
Lee, Seyong; Ko, Il-Won; Yoon, In-Ho; Kim, Dong-Wook; Kim, Kyoung-Woong
2018-03-24
Colloid mobilization is a significant process governing colloid-associated transport of heavy metals in subsurface environments. It has been studied for the last three decades to understand this process. However, colloid mobilization and heavy metal transport in soil solutions have rarely been studied using soils in South Korea. We investigated the colloid mobilization in a variety of flow rates during sampling soil solutions in sand columns. The colloid concentrations were increased at low flow rates and in saturated regimes. Colloid concentrations increased 1000-fold higher at pH 9.2 than at pH 7.3 in the absence of 10 mM NaCl solution. In addition, those were fourfold higher in the absence than in the presence of the NaCl solution at pH 9.2. It was suggested that the mobility of colloids should be enhanced in porous media under the basic conditions and the low ionic strength. In real field soils, the concentrations of As, Cr, and Pb in soil solutions increased with the increase in colloid concentrations at initial momentarily changed soil water pressure, whereas the concentrations of Cd, Cu, Fe, Ni, Al, and Co lagged behind the colloid release. Therefore, physicochemical changes and heavy metal characteristics have important implications for colloid-facilitated transport during sampling soil solutions.
Kuruthukulangarakoola, Gitto Thomas; Zhang, Jiangli; Albert, Andreas; Winkler, Barbro; Lang, Hans; Buegger, Franz; Gaupels, Frank; Heller, Werner; Michalke, Bernhard; Sarioglu, Hakan; Schnitzler, Jörg-Peter; Hebelstrup, Kim Henrik; Durner, Jörg; Lindermayr, Christian
2017-01-01
Nitric oxide (NO) is an important signalling molecule that is involved in many different physiological processes in plants. Here, we report about a NO-fixing mechanism in Arabidopsis, which allows the fixation of atmospheric NO into nitrogen metabolism. We fumigated Arabidopsis plants cultivated in soil or as hydroponic cultures during the whole growing period with up to 3 ppmv of NO gas. Transcriptomic, proteomic and metabolomic analyses were used to identify non-symbiotic haemoglobin proteins as key components of the NO-fixing process. Overexpressing non-symbiotic haemoglobin 1 or 2 genes resulted in fourfold higher nitrate levels in these plants compared with NO-treated wild-type. Correspondingly, rosettes size and weight, vegetative shoot thickness and seed yield were 25, 40, 30, and 50% higher, respectively, than in wild-type plants. Fumigation with 250 ppbv 15 NO confirmed the importance of non-symbiotic haemoglobin 1 and 2 for the NO-fixation pathway, and we calculated a daily uptake for non-symbiotic haemoglobin 2 overexpressing plants of 250 mg N/kg dry weight. This mechanism is probably important under conditions with limited N supply via the soil. Moreover, the plant-based NO uptake lowers the concentration of insanitary atmospheric NOx, and in this context, NO-fixation can be beneficial to air quality. © 2016 The Authors Plant, Cell & Environment Published by John Wiley & Sons Ltd.
Wang, Ning; Mebane, Christopher A.; Kunz, James L.; Ingersoll, Christopher G.; Brumbaugh, William G.; Santore, Robert C.; Gorsuch, Joseph W.; Arnold, W. Ray
2011-01-01
Acute and chronic toxicity of copper (Cu) to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) were determined in water exposures at four concentrations of dissolved organic carbon (DOC; nominally 0.5, 2.5, 5, and 10 mg/L as carbon [C]). Test waters with DOC concentrations of 2.5 to 10 mg C/L were prepared by mixing a concentrate of natural organic matter (Suwannee River, GA, USA) in diluted well water (hardness 100 mg/L as CaCO3, pH 8.3, DOC 0.5 mg C/L). Acute median effect concentrations (EC50s) for dissolved Cu increased approximately fivefold (15–72 μg Cu/L) for mussel survival in 4-d exposures and increased about 11-fold (25–267 μg Cu/L) for cladoceran survival in 2-d exposures across DOC concentrations from 0.5 to 10 mg C/L. Similarly, chronic 20% effect concentrations (EC20s) for the mussel in 28-d exposures increased about fivefold (13–61 μg Cu/L for survival; 8.8–38 μg Cu/L for biomass), and the EC20s for the cladoceran in 7-d exposures increased approximately 17-fold (13–215 μg Cu/L) for survival or approximately fourfold (12–42 μg Cu/L) for reproduction across DOC concentrations from 0.5 to 10 mg C/L. The acute and chronic values for the mussel were less than or approximately equal to the values for the cladoceran. Predictions from the biotic ligand model (BLM) used to derive the U.S. Environmental Protection Agency's ambient water quality criteria (AWQC) for Cu explained more than 90% of the variation in the acute and chronic endpoints for the two species, with the exception of the EC20 for cladoceran reproduction (only 46% of variation explained). The BLM-normalized acute EC50s and chronic EC20s for the mussel and BLM-normalized chronic EC20s for the cladoceran in waters with DOC concentrations of 2.5 to 10 mg C/L were equal to or less than the final acute value and final chronic value in the BLM-based AWQC for Cu, respectively, indicating that the Cu AWQC might not adequately protect the mussel from acute and chronic exposure, and the cladoceran from chronic exposure.
Stephenson, William J.; Odum, Jack K.; Williams, Robert A.; McBride, John H.; Tomlinson, Iris
2012-01-01
We conducted active and passive seismic imaging investigations along a 5.6-km-long, east–west transect ending at the mapped trace of the Wasatch fault in southern Utah Valley. Using two-dimensional (2D) P-wave seismic reflection data, we imaged basin deformation and faulting to a depth of 1.4 km and developed a detailed interval velocity model for prestack depth migration and 2D ground-motion simulations. Passive-source microtremor data acquired at two sites along the seismic reflection transect resolve S-wave velocities of approximately 200 m/s at the surface to about 900 m/s at 160 m depth and confirm a substantial thickening of low-velocity material westward into the valley. From the P-wave reflection profile, we interpret shallow (100–600 m) bedrock deformation extending from the surface trace of the Wasatch fault to roughly 1.5 km west into the valley. The bedrock deformation is caused by multiple interpreted fault splays displacing fault blocks downward to the west of the range front. Further west in the valley, the P-wave data reveal subhorizontal horizons from approximately 90 to 900 m depth that vary in thickness and whose dip increases with depth eastward toward the Wasatch fault. Another inferred fault about 4 km west of the mapped Wasatch fault displaces horizons within the valley to as shallow as 100 m depth. The overall deformational pattern imaged in our data is consistent with the Wasatch fault migrating eastward through time and with the abandonment of earlier synextensional faults, as part of the evolution of an inferred 20-km-wide half-graben structure within Utah Valley. Finite-difference 2D modeling suggests the imaged subsurface basin geometry can cause fourfold variation in peak ground velocity over distances of 300 m.
Elrayah-Eliadarous, Hind A; Östenson, Claes-Göran; Eltom, Mohamed; Johansson, Pia; Sparring, Vibeke; Wahlström, Rolf
2017-12-01
Diabetes mellitus accounts for 11% of total health expenditure worldwide, and most people with diabetes live in low- and middle-income countries. The present study examined the economic and social effects attributed to diabetes in Sudan by calculating out-of-pocket medical expenses and the health and social effects of the disease for people with diabetes (n = 375) and their families compared with a non-diabetic control group (n = 375), matched for age, sex, and residence area. Data were obtained in 2013 in four states within the Sudan, via structured interviews, using instruments from the International Diabetes Federation. Descriptive statistics were used to analyze differences between case and control participants. The median total annual medical expenditure was fourfold higher for people with than without diabetes (US$579 vs US$148, respectively). Annual mean expenditure was 85% higher for those with diabetes (US$1004 vs US$544). People with diabetes were also significantly more likely to suffer from serious comorbidities, such as cardiovascular disorders and foot ulcers, compared with control participants. Moreover, those with diabetes reported a higher proportion of personal adverse social effects, such as being prevented from doing paid work or participating in education, both for themselves and their families. The high economic burden and adverse social effects on people with diabetes and their families in Sudan call for the development of evidence-based policy and program strategies for the prevention and management of diabetes, with an emphasis on low-resource communities. © 2017 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.
Sub-physiological oxygen levels optimal for growth and survival of human atrial cardiac stem cells.
RajendranNair, Deepthi Sreerengam; Karunakaran, Jayakumar; Nair, Renuka R
2017-08-01
Cardiac stem cells reside in niches where the oxygen levels are close to 3%. For cytotherapy, cells are conventionally expanded in ambient oxygen (21% O 2 ) which represents hyperoxia compared to the oxygen tension of niches. Cardiosphere-derived cells (CDCs) are then transplanted to host tissue with lower-O 2 levels. The high-O 2 gradient can reduce the efficacy of cultured cells. Based on the assumption that minimizing injury due to O 2 gradients will enhance the yield of functionally efficient cells, CDCs were cultured in 3% O 2 and compared with cells maintained in ambient O 2 . CDCs were isolated from human right atrial explants and expanded in parallel in 21 and 3% oxygen and compared with regard to survival, proliferation, and retention of stemness. Increased cell viability even in the tenth passage and enhanced cardiosphere formation was observed in cells expanded in 3% O 2 . The cell yield from seven passages was fourfold higher for cells cultured in 3% O 2 . Preservation of stemness in hypoxic environment was evident from the proportion of c-kit-positive cells and reduced myogenic differentiation. Hypoxia promoted angiogenesis and reduced the tendency to differentiate to noncardiac lineages (adipocytes and osteocytes). Mimicking the microenvironment at transplantation, when shifted to 5% O 2 , viability and proliferation rate were significantly higher for CDCs expanded in 3% O 2 . Expansion of CDCs, from atria in sub-physiological oxygen, helps in obtaining a higher yield of healthy cells with better preservation of stem cell characteristics. The cells so cultured are expected to improve engraftment and facilitate myocardial regeneration.
Lukanova, A; Toniolo, P; Zhitkovich, A; Nikolova, V; Panev, T; Popov, T; Taioli, E; Costa, M
1996-01-01
The relationships between chromium (Cr) levels in lymphocytes, erythrocytes, urine, and ambient air were compared among 14 chrome-platers from a metallurgic plant in Bulgaria and two groups of local controls, one from the same heavily polluted industrial town as the chrome-platers (n = 11) and one from a seaside resort town 100 km away (n = 6). Among the chrome-platers, the Cr concentration in peripheral lymphocytes was positively correlated with total Cr and Cr(VI) levels in ambient air and with Cr excretion in urine. As compared to the controls, the chrome-platers had mean Cr levels in lymphocytes twice as high, in erythrocytes ninefold higher, and in urine fourfold to eightfold higher. Although Cr levels in urine and lymphocytes were similar between the two control groups, levels in erythrocytes were 3 times higher among subjects from the industrial area than among those from the seaside town. The study suggests that lymphocyte Cr could be a good indicator of the Cr body burden caused by high exposures to Cr(VI), such as in electroplating operations. In these conditions, erythrocyte Cr may be less useful, possibly owing to increased toxicity due to the high affinity of erythrocytes for Cr. However, when exposure is lower, such as in most environmental situations, erythrocyte Cr should provide a better and more sensitive index than lymphocyte Cr. By contrast, urinary Cr, which provides information on total Cr exposure, including Cr(III) from dietary and environmental sources, does not seem to be of value for studying occupational exposure to Cr(VI).
The Case for Targeting Leadership in War
1992-02-13
to the four-fold increase in terrorist incidents worldwide during Desert Shield, 35% of which were in the U.S.72 Others warn of the risk that our...inherently disadvantaged --both in the means by which they can assassinate the President, and in the potential impact a successful assassination would...mechanisms for ensuring survival of the Communist Party and its leadership cadres," the U.S. has placed at risk ’those political entities the Soviet
David L. Evans
1997-01-01
Nocturnal netting operations have been conducted at the Hawk Ridge Nature Reserve since 1972. From 1988 to 1992 a recording of human whistles simulating the calls of fall migrant Northern Saw-whet Owls (Aegolius acadicus) was broadcast on a random, on or off, half-night basis. Mist net captures of Saw-whet Owls increased about fourfold during the...
Multifunctional energy landscape for a DNA G-quadruplex: An evolved molecular switch
NASA Astrophysics Data System (ADS)
Cragnolini, Tristan; Chakraborty, Debayan; Šponer, Jiří; Derreumaux, Philippe; Pasquali, Samuela; Wales, David J.
2017-10-01
We explore the energy landscape for a four-fold telomere repeat, obtaining interconversion pathways between six experimentally characterised G-quadruplex topologies. The results reveal a multi-funnel system, with a variety of intermediate configurations and misfolded states. This organisation is identified with the intrinsically multi-functional nature of the system, suggesting a new paradigm for the classification of such biomolecules and clarifying issues regarding apparently conflicting experimental results.
Cytosine arabinoside influx and nucleoside transport sites in acute leukemia.
Wiley, J S; Jones, S P; Sawyer, W H; Paterson, A R
1982-02-01
Although cytosine arabinoside (araC) can induce a remission in a majority of patients presenting with acute myeloblastic leukemia (AML), a minority fail to respond and moreover the drug has less effect in acute lymphoblastic leukemia (ALL). The carrier-mediated influx of araC into purified blasts from patients with AML, ALL, and acute undifferentiated leukemia (AUL) has been compared to that of normal lymphocytes and polymorphs. Blasts showed a larger mediated influx of araC than mature cells, since mean influxes for myeloblasts and lymphoblasts were 6- and 2.3-fold greater than polymorphs and lymphocytes, respectively. Also, the mean influx for myeloblasts was fourfold greater than the mean for lymphoblasts. The number of nucleoside transport sites was estimated for each cell type by measuring the equilibrium binding of [(3)H]nitrobenzylthioinosine (NBMPR), which inhibits nucleoside fluxes by binding with high affinity to specific sites on the transport mechanism. The mean binding site numbers for myeloblasts and lymphoblasts were 5- and 2.8-fold greater, respectively, than for the mature cells of the same maturation series. The mean number of NBMPR binding sites for myeloblasts was fourfold greater than for lymphoblasts. Patients with AUL were heterogeneous since blasts from some gave values within the myeloblastic range and others within the lymphoblastic range. The araC influx correlated closely with the number of NBMPR binding sites measured in the same cells on the same day. Transport parameters were measured on blasts from 15 patients with AML or AUL who were then treated with standard induction therapy containing araC. Eight patients entered complete remission, while seven failed therapy, among whom were the three patients with the lowest araC influx (<0.4 pmol/10(7) cells per min) and NBMPR binding (<3,000 sites/cell) for the treated group. In summary, myeloblasts have both higher araC transport rates and more nucleoside transport sites than lymphoblasts and this factor may contribute to the greater sensitivity of AML to this drug. AraC transport varied >10-fold between leukemic blasts and normal leukocytes, but transport capacity related directly to the number of nucleoside transport sites on the cell. Finally, low araC transport rates or few NBMPR binding sites on blasts were observed in a subset of patients with acute leukemia who failed to achieve remission with drug combinations containing araC.
Comparison of Liver Cell Models Using the Basel Phenotyping Cocktail.
Berger, Benjamin; Donzelli, Massimiliano; Maseneni, Swarna; Boess, Franziska; Roth, Adrian; Krähenbühl, Stephan; Haschke, Manuel
2016-01-01
Currently used hepatocyte cell systems for in vitro assessment of drug metabolism include hepatoma cell lines and primary human hepatocyte (PHH) cultures. We investigated the suitability of the validated in vivo Basel phenotyping cocktail (caffeine [CYP1A2], efavirenz [CYP2B6], losartan [CYP2C9], omeprazole [CYP2C19], metoprolol [CYP2D6], midazolam [CYP3A4]) in vitro and characterized four hepatocyte cell systems (HepG2 cells, HepaRG cells, and primary cryopreserved human hepatocytes in 2-dimensional [2D] culture or in 3D-spheroid co-culture) regarding basal metabolism and CYP inducibility. Under non-induced conditions, all CYP activities could be determined in 3D-PHH, CYP2B6, CYP2C19, CYP2D6, and CYP3A4 in 2D-PHH and HepaRG, and CYP2C19 and CYP3A4 in HepG2 cells. The highest non-induced CYP activities were observed in 3D-PHH and HepaRG cells. mRNA expression was at least four-fold higher for all CYPs in 3D-PHH compared to the other cell systems. After treatment with 20 μM rifampicin, mRNA increased 3- to 50-fold for all CYPs except CYP1A2 and 2D6 for HepaRG and 3D-PHH, 4-fold (CYP2B6) and 17-fold (CYP3A4) for 2D-PHH and four-fold (CYP3A4) for HepG2. In 3D-PHH at least a two-fold increase in CYP activity was observed for all inducible CYP isoforms while CYP1A2 and CYP2C9 activity did not increase in 2D-PHH and HepaRG. CYP inducibility assessed in vivo using the same phenotyping probes was also best reflected by the 3D-PHH model. Our studies show that 3D-PHH and (with some limitations) HepaRG are suitable cell systems for assessing drug metabolism and CYP induction in vitro . HepG2 cells are less suited to assess CYP induction of the 2C and 3A family. The Basel phenotyping cocktail is suitable for the assessment of CYP activity and induction also in vitro .
Comparison of Liver Cell Models Using the Basel Phenotyping Cocktail
Berger, Benjamin; Donzelli, Massimiliano; Maseneni, Swarna; Boess, Franziska; Roth, Adrian; Krähenbühl, Stephan; Haschke, Manuel
2016-01-01
Currently used hepatocyte cell systems for in vitro assessment of drug metabolism include hepatoma cell lines and primary human hepatocyte (PHH) cultures. We investigated the suitability of the validated in vivo Basel phenotyping cocktail (caffeine [CYP1A2], efavirenz [CYP2B6], losartan [CYP2C9], omeprazole [CYP2C19], metoprolol [CYP2D6], midazolam [CYP3A4]) in vitro and characterized four hepatocyte cell systems (HepG2 cells, HepaRG cells, and primary cryopreserved human hepatocytes in 2-dimensional [2D] culture or in 3D-spheroid co-culture) regarding basal metabolism and CYP inducibility. Under non-induced conditions, all CYP activities could be determined in 3D-PHH, CYP2B6, CYP2C19, CYP2D6, and CYP3A4 in 2D-PHH and HepaRG, and CYP2C19 and CYP3A4 in HepG2 cells. The highest non-induced CYP activities were observed in 3D-PHH and HepaRG cells. mRNA expression was at least four-fold higher for all CYPs in 3D-PHH compared to the other cell systems. After treatment with 20 μM rifampicin, mRNA increased 3- to 50-fold for all CYPs except CYP1A2 and 2D6 for HepaRG and 3D-PHH, 4-fold (CYP2B6) and 17-fold (CYP3A4) for 2D-PHH and four-fold (CYP3A4) for HepG2. In 3D-PHH at least a two-fold increase in CYP activity was observed for all inducible CYP isoforms while CYP1A2 and CYP2C9 activity did not increase in 2D-PHH and HepaRG. CYP inducibility assessed in vivo using the same phenotyping probes was also best reflected by the 3D-PHH model. Our studies show that 3D-PHH and (with some limitations) HepaRG are suitable cell systems for assessing drug metabolism and CYP induction in vitro. HepG2 cells are less suited to assess CYP induction of the 2C and 3A family. The Basel phenotyping cocktail is suitable for the assessment of CYP activity and induction also in vitro. PMID:27917125
Self-force calculations with matched expansions and quasinormal mode sums
DOE Office of Scientific and Technical Information (OSTI.GOV)
Casals, Marc; Dolan, Sam; Ottewill, Adrian C.
2009-06-15
Accurate modeling of gravitational wave emission by extreme-mass ratio inspirals is essential for their detection by the LISA mission. A leading perturbative approach involves the calculation of the self-force acting upon the smaller orbital body. In this work, we present the first application of the Poisson-Wiseman-Anderson method of 'matched expansions' to compute the self-force acting on a point particle moving in a curved spacetime. The method employs two expansions for the Green function, which are, respectively, valid in the 'quasilocal' and 'distant past' regimes, and which may be matched together within the normal neighborhood. We perform our calculation in amore » static region of the spherically symmetric Nariai spacetime (dS{sub 2}xS{sup 2}), in which scalar-field perturbations are governed by a radial equation with a Poeschl-Teller potential (frequently used as an approximation to the Schwarzschild radial potential) whose solutions are known in closed form. The key new ingredients in our study are (i) very high order quasilocal expansions and (ii) expansion of the distant past Green function in quasinormal modes. In combination, these tools enable a detailed study of the properties of the scalar-field Green function. We demonstrate that the Green function is singular whenever x and x{sup '} are connected by a null geodesic, and apply asymptotic methods to determine the structure of the Green function near the null wave front. We show that the singular part of the Green function undergoes a transition each time the null wave front passes through a caustic point, following a repeating fourfold sequence {delta}({sigma}), 1/{pi}{sigma}, -{delta}({sigma}), -1/{pi}{sigma}, etc., where {sigma} is Synge's world function. The matched-expansion method provides insight into the nonlocal properties of the self-force. We show that the self-force generated by the segment of the worldline lying outside the normal neighborhood is not negligible. We apply the matched-expansion method to compute the scalar self-force acting on a static particle on the Nariai spacetime, and validate against an alternative method, obtaining agreement to six decimal places. We conclude with a discussion of the implications for wave propagation and self-force calculations. On black hole spacetimes, any expansion of the Green function in quasinormal modes must be augmented by a branch-cut integral. Nevertheless, we expect the Green function in Schwarzschild spacetime to inherit certain key features, such as a fourfold singular structure manifesting itself through the asymptotic behavior of quasinormal modes. In this way, the Nariai spacetime provides a fertile testing ground for developing insight into the nonlocal part of the self-force on black hole spacetimes.« less
Thermal and suprathermal protons and alpha particles in the earth's plasma sheet
NASA Technical Reports Server (NTRS)
Ipavich, F. M.; Scholer, M.
1983-01-01
Detailed proton energy spectra in the quasi-stable distant plasma sheet over the energy range from approximately 13 keV to approximately 130 keV are presented. These spectra are compared with spectra of simultaneously measured alpha particles in the energy range from approximately 30 keV/Q to approximately 130 keV/Q. The proton spectra are then extended into the higher energy range up to approximately 1 MeV, thereby supplementing the study of Sarris et al. (1981). The temporal behavior of the spectra in the higher energy range is discussed. It is found that below about 16 keV the proton spectra can be represented by a Maxwellian distribution; above this level, a suprathermal tail is found that cannot be represented by a single power law.
A general moment expansion method for stochastic kinetic models
NASA Astrophysics Data System (ADS)
Ale, Angelique; Kirk, Paul; Stumpf, Michael P. H.
2013-05-01
Moment approximation methods are gaining increasing attention for their use in the approximation of the stochastic kinetics of chemical reaction systems. In this paper we derive a general moment expansion method for any type of propensities and which allows expansion up to any number of moments. For some chemical reaction systems, more than two moments are necessary to describe the dynamic properties of the system, which the linear noise approximation is unable to provide. Moreover, also for systems for which the mean does not have a strong dependence on higher order moments, moment approximation methods give information about higher order moments of the underlying probability distribution. We demonstrate the method using a dimerisation reaction, Michaelis-Menten kinetics and a model of an oscillating p53 system. We show that for the dimerisation reaction and Michaelis-Menten enzyme kinetics system higher order moments have limited influence on the estimation of the mean, while for the p53 system, the solution for the mean can require several moments to converge to the average obtained from many stochastic simulations. We also find that agreement between lower order moments does not guarantee that higher moments will agree. Compared to stochastic simulations, our approach is numerically highly efficient at capturing the behaviour of stochastic systems in terms of the average and higher moments, and we provide expressions for the computational cost for different system sizes and orders of approximation. We show how the moment expansion method can be employed to efficiently quantify parameter sensitivity. Finally we investigate the effects of using too few moments on parameter estimation, and provide guidance on how to estimate if the distribution can be accurately approximated using only a few moments.
Higher-order harmonics of general limited diffraction Bessel beams
NASA Astrophysics Data System (ADS)
Ding, De-Sheng; Huang, Jin-Huang
2016-12-01
In this paper, we extensively study the higher-order harmonic generation of the general limited diffraction m-th-order Bessel beam. The analysis is based on successive approximations of the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation. Asymptotic expansions are presented for higher-order harmonic Bessel beams in near and far fields. The validity of asymptotic approximation is also analyzed. The higher-order harmonic of the Bessel beam with the lowest zero-order is taken as a special example. Project supported by the National Natural Science Foundation of China (Grant Nos. 11074038 and 11374051).
Forced Imbibition in Porous Media: A Fourfold Scenario
NASA Astrophysics Data System (ADS)
Odier, Céleste; Levaché, Bertrand; Santanach-Carreras, Enric; Bartolo, Denis
2017-11-01
We establish a comprehensive description of the patterns formed when a wetting liquid displaces a viscous fluid confined in a porous medium. Building on model microfluidic experiments, we evidence four imbibition scenarios all yielding different large-scale morphologies. Combining high-resolution imaging and confocal microscopy, we show that they originate from two liquid-entrainment transitions and a Rayleigh-Plateau instability at the pore scale. Finally, we demonstrate and explain the long-time coarsening of the resulting patterns.
Finite difference schemes for long-time integration
NASA Technical Reports Server (NTRS)
Haras, Zigo; Taasan, Shlomo
1993-01-01
Finite difference schemes for the evaluation of first and second derivatives are presented. These second order compact schemes were designed for long-time integration of evolution equations by solving a quadratic constrained minimization problem. The quadratic cost function measures the global truncation error while taking into account the initial data. The resulting schemes are applicable for integration times fourfold, or more, longer than similar previously studied schemes. A similar approach was used to obtain improved integration schemes.
Todorova, Teodora; Pesheva, Margarita; Gregan, Fridrich; Chankova, Stephka
2015-04-01
The aim of this work was to analyze the antioxidant and antimutagenic/anticarcinogenic capacity of Papaver rhoeas L. water extract against standard mutagen/carcinogen methyl methanesulfonate (MMS) and radiomimetic zeocin (Zeo) on a test system Saccharomyces cerevisiae. The following assays were used: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, quantitative determination of superoxide anion (antireactive oxygen species [antiROS test]), DNA topology assay, D7ts1 test--for antimutagenic--and Ty1 transposition test--for anticarcinogenic effects. Strong pro-oxidative capacity of Zeo was shown to correlate with its well-expressed mutagenic and carcinogenic properties. The mutagenic and carcinogenic effects of MMS were also confirmed. Our data concerning the antioxidant activity of P. rhoeas L. extract revealed that concentration corresponding to IC(50) in the DPPH assay possessed the highest antioxidant activity in the antiROS biological assay. It was also observed that a concentration with 50% scavenging activity expressed the most pronounced antimutagenic properties decreasing Zeo-induced gene conversion twofold, reverse mutation fivefold, and total aberrations fourfold. The same concentration possessed well-expressed anticarcinogenic properties measured as reduction of MMS-induced Ty1 transposition rate fivefold and fourfold when Zeo was used as an inductor. Based on the well-expressed antioxidant, antimutagenic, and anticarcinogenic properties obtained in this work, the P. rhoeas L. extract could be recommended for further investigations and possible use as a food additive.
Characteristics of the fourth order resonance in high intensity linear accelerators
Jeon, D.; Hwang, Kyung Ryun
2017-06-19
For the 4σ = 360° space-charge resonance in high intensity linear accelerators, the emittance growth is surveyed for input Gaussian beams, as a function of the depressed phase advance per cell σ and the initial tune depression (σ o – σ). For each data point, the linac lattice is designed such that the fourth order resonance dominates over the envelope instability. Additionally, the data show that the maximum emittance growth takes place at σ ≈ 87° over a wide range of the tune depression (or beam current), which confirms that the relevant parameter for the emittance growth is σ andmore » that for the bandwidth is σ o – σ. An interesting four-fold phase space structure is observed that cannot be explained with the fourth order resonance terms alone. Analysis attributes this effect to a small negative sixth order detuning term as the beam is redistributed by the resonance. Analytical studies show that the tune increases monotonically for the Gaussian beam which prevents the resonance for σ > 90°. Lastly, frequency analysis indicates that the four-fold structure observed for input Kapchinskij-Vladmirskij beams when σ < 90°, is not the fourth order resonance but a fourth order envelope instability because the 1/4 = 90°/360° component is missing in the frequency spectrum.« less
Characteristics of the fourth order resonance in high intensity linear accelerators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jeon, D.; Hwang, Kyung Ryun
For the 4σ = 360° space-charge resonance in high intensity linear accelerators, the emittance growth is surveyed for input Gaussian beams, as a function of the depressed phase advance per cell σ and the initial tune depression (σ o – σ). For each data point, the linac lattice is designed such that the fourth order resonance dominates over the envelope instability. Additionally, the data show that the maximum emittance growth takes place at σ ≈ 87° over a wide range of the tune depression (or beam current), which confirms that the relevant parameter for the emittance growth is σ andmore » that for the bandwidth is σ o – σ. An interesting four-fold phase space structure is observed that cannot be explained with the fourth order resonance terms alone. Analysis attributes this effect to a small negative sixth order detuning term as the beam is redistributed by the resonance. Analytical studies show that the tune increases monotonically for the Gaussian beam which prevents the resonance for σ > 90°. Lastly, frequency analysis indicates that the four-fold structure observed for input Kapchinskij-Vladmirskij beams when σ < 90°, is not the fourth order resonance but a fourth order envelope instability because the 1/4 = 90°/360° component is missing in the frequency spectrum.« less
Takeshita, S; Kikuno, R; Tezuka, K; Amann, E
1993-01-01
A cDNA library prepared from the mouse osteoblastic cell line MC3T3-E1 was screened for the presence of specifically expressed genes by employing a combined subtraction hybridization/differential screening approach. A cDNA was identified and sequenced which encodes a protein designated osteoblast-specific factor 2 (OSF-2) comprising 811 amino acids. OSF-2 has a typical signal sequence, followed by a cysteine-rich domain, a fourfold repeated domain and a C-terminal domain. The protein lacks a typical transmembrane region. The fourfold repeated domain of OSF-2 shows homology with the insect protein fasciclin I. RNA analyses revealed that OSF-2 is expressed in bone and to a lesser extent in lung, but not in other tissues. Mouse OSF-2 cDNA was subsequently used as a probe to clone the human counterpart. Mouse and human OSF-2 show a high amino acid sequence conservation except for the signal sequence and two regions in the C-terminal domain in which 'in-frame' insertions or deletions are observed, implying alternative splicing events. On the basis of the amino acid sequence homology with fasciclin I, we suggest that OSF-2 functions as a homophilic adhesion molecule in bone formation. Images Figure 3 Figure 4 Figure 5 Figure 6 PMID:8363580
Single-shot magnetic resonance spectroscopic imaging with partial parallel imaging.
Posse, Stefan; Otazo, Ricardo; Tsai, Shang-Yueh; Yoshimoto, Akio Ernesto; Lin, Fa-Hsuan
2009-03-01
A magnetic resonance spectroscopic imaging (MRSI) pulse sequence based on proton-echo-planar-spectroscopic-imaging (PEPSI) is introduced that measures two-dimensional metabolite maps in a single excitation. Echo-planar spatial-spectral encoding was combined with interleaved phase encoding and parallel imaging using SENSE to reconstruct absorption mode spectra. The symmetrical k-space trajectory compensates phase errors due to convolution of spatial and spectral encoding. Single-shot MRSI at short TE was evaluated in phantoms and in vivo on a 3-T whole-body scanner equipped with a 12-channel array coil. Four-step interleaved phase encoding and fourfold SENSE acceleration were used to encode a 16 x 16 spatial matrix with a 390-Hz spectral width. Comparison with conventional PEPSI and PEPSI with fourfold SENSE acceleration demonstrated comparable sensitivity per unit time when taking into account g-factor-related noise increases and differences in sampling efficiency. LCModel fitting enabled quantification of inositol, choline, creatine, and N-acetyl-aspartate (NAA) in vivo with concentration values in the ranges measured with conventional PEPSI and SENSE-accelerated PEPSI. Cramer-Rao lower bounds were comparable to those obtained with conventional SENSE-accelerated PEPSI at the same voxel size and measurement time. This single-shot MRSI method is therefore suitable for applications that require high temporal resolution to monitor temporal dynamics or to reduce sensitivity to tissue movement.
Zebrafish CaV2.1 Calcium Channels Are Tailored for Fast Synchronous Neuromuscular Transmission
Naranjo, David; Wen, Hua; Brehm, Paul
2015-01-01
The CaV2.2 (N-type) and CaV2.1 (P/Q-type) voltage-dependent calcium channels are prevalent throughout the nervous system where they mediate synaptic transmission, but the basis for the selective presence at individual synapses still remains an open question. The CaV2.1 channels have been proposed to respond more effectively to brief action potentials (APs), an idea supported by computational modeling. However, the side-by-side comparison of CaV2.1 and CaV2.2 kinetics in intact neurons failed to reveal differences. As an alternative means for direct functional comparison we expressed zebrafish CaV2.1 and CaV2.2 α-subunits, along with their accessory subunits, in HEK293 cells. HEK cells lack calcium currents, thereby circumventing the need for pharmacological inhibition of mixed calcium channel isoforms present in neurons. HEK cells also have a simplified morphology compared to neurons, which improves voltage control. Our measurements revealed faster kinetics and shallower voltage-dependence of activation and deactivation for CaV2.1. Additionally, recordings of calcium current in response to a command waveform based on the motorneuron AP show, directly, more effective activation of CaV2.1. Analysis of calcium currents associated with the AP waveform indicate an approximately fourfold greater open probability (PO) for CaV2.1. The efficient activation of CaV2.1 channels during APs may contribute to the highly reliable transmission at zebrafish neuromuscular junctions. PMID:25650925
Cytotoxic and Antimicrobial Constituents from the Essential Oil of Lippia alba (Verbenaceae)
dos Santos, Nara O.; Pascon, Renata C.; Vallim, Marcelo A.; Figueiredo, Carlos R.; Soares, Marisi G.; Lago, João Henrique G.; Sartorelli, Patricia
2016-01-01
Backgroud: Lippia alba (Verbenaceae) is a plant widely used in folk medicine to treat various diseases. The present work deals with the chemical composition of the crude essential oil extracted from leaves of L. alba and evaluation of its antimicrobial and cytotoxic activities. Methods: Leaves of L. alba were extracted by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) as well as by nuclear magnetic resonance (NMR) spectroscopy. Cytotoxic and antimicrobial activities of crude essential oil were evaluated in vitro using MTT and broth microdilution assays, respectively. Results: Chemical analysis afforded the identification of 39 substances corresponding to 99.45% of the total oil composition. Concerning the main compounds, monoterpenes nerol/geraniol and citral correspond to approximately 50% of crude oil. The cytotoxic activity of obtained essential oil against several tumor cell lines showed IC50 values ranging from 45 to 64 µg/mL for B16F10Nex2 (murine melanoma) and A549 (human lung adenocarcinoma). In the antimicrobial assay, was observed that all tested yeast strains, except C. albicans, were sensitive to crude essential oil. MIC values were two to four-folds lower than those determined to bacterial strains. Conclusion: Analysis of chemical composition of essential oils from leaves of L. alba suggested a new chemotype nerol/geraniol and citral. Based in biological evidences, a possible application for studied oil as an antifungal in medicine, as well as in agriculture, is described. PMID:28930132
Reichelt, R; Günther, S; Wintterlin, J; Moritz, W; Aballe, L; Mentes, T O
2007-10-07
A low energy electron diffraction (LEED) I/V analysis was performed of the (4 x 4) oxygen structure on Ag(111). Two data sets were used, one recorded with a conventional LEED system and a second with a low energy electron microscope (LEEM). The data sets agree well with each other, demonstrating that I/V structure analyses can be performed with the same quality with LEEM as with conventional LEED. The structure obtained confirms the recently proposed model that involves a reconstruction of the Ag(111) surface. Previous models based on a thin layer of Ag(2)O that had been accepted for more than 30 years are disproved. The reconstruction model contains two units of six triangularly arranged Ag atoms and a stacking fault in one half of the unit cell. The six O atoms per unit cell occupy sites in the trenches between the Ag(6) triangles. Small lateral displacements of the Ag atoms lift the mirror symmetry of the structure, leading to two nonequivalent groups of O atoms. The atoms of both groups are located approximately 0.5 Angstrom below the top Ag layer, on fourfold positions with respect to the top layer Ag atoms. Ag-O distances between 2.05 and 2.3 Angstrom are found. The oxygen atoms exhibit large static or dynamic displacements of up to 0.3 Angstrom at 300 K.
Local structural environments of Ge doped in eutectic Sb-Te film before and after crystallization
NASA Astrophysics Data System (ADS)
Shin, Sang Yeol; Cheong, Byung-ki; Choi, Yong Gyu
2018-06-01
Electrical phase change device using the Ge-doped eutectic Sb-Te (e.g., Ge1Sb8Te2) film is known to exhibit improved energy efficiency thanks to lowered threshold voltage as well as decreased power consumption for the reset operation, as compared with Ge2Sb2Te5 film. Ge K-edge EXAFS analysis is employed in this study in an effort to elucidate such merits of Ge1Sb8Te2 film in connection with its local atomic arrangements. It is then verified that a Ge atom is four-fold coordinated in its nearest-neighboring shell both in the as-deposited and in the annealed films. It needs to be highlighted that approximately two Sb atoms constitute the Ge tetrahedral units in its amorphous state; however, after being crystallized, heteropolar Ge-Sb bonds hardly exist in this Ge1Sb8Te2 film. It has been known that crystallization temperature and activation energy for crystallization of this Ge1Sb8Te2 composition are greater than those of Ge2Sb2Te5 composition. In addition, these two phase change materials exhibit distinctly different crystallization mechanisms, i.e., nucleation-dominant for Ge2Sb2Te5 film but growth-dominant for Ge1Sb8Te2 film. These discrepancies in the crystallization-related properties are delineated in terms of the local structural changes verified from the present EXAFS analysis.
Willenborg, Christian J; Brûlé-Babel, Anita L; Van Acker, Rene C
2010-06-01
Transgenic wheat (Triticum aestivum L.) with improved agronomic traits is currently being field-tested. Gene flow in space is well-documented, but isolation in time has not received comparable attention. Here, we report the results of a field experiment that investigated reductions in intraspecific gene flow associated with temporal isolation of flowering between T. aestivum conspecifics. Pollen-mediated gene flow (PMGF) between an imazamox-resistant (IR) volunteer wheat population and a non-IR spring wheat crop was assessed over a range of volunteer emergence timings and plant population densities that collectively promoted flowering asynchrony. Natural hybridization events between the two populations were detected by phenotypically scoring plants in F(1) populations followed by verification with Mendelian segregation ratios in the F(1:2) lines. Based on the examination of >545,000 seedlings, we identified a hybridization window in spring wheat approximately 125 growing degree-days (GDD) in length. We found a sizeable reduction (two- to four-fold) in gene flow frequencies when flowering occurred outside of this window. The hybridization window identified in this research also will serve to temporally isolate neighboring wheat crops. However, strict control of volunteer populations or spatial isolation of neighbouring crops emerging within a 125 GDD hybridization window will be necessary to maintain low frequencies of PMGF in spring wheat fields. The model developed herein also is likely to be applicable to other wind-pollinated species.
Clerk, Angela; Michael, Ashour; Sugden, Peter H.
1998-01-01
We examined the activation of the p38 mitogen-activated protein kinase (p38-MAPK) pathway by the G protein–coupled receptor agonists, endothelin-1 and phenylephrine in primary cultures of cardiac myocytes from neonatal rat hearts. Both agonists increased the phosphorylation (activation) of p38-MAPK by ∼12-fold. A p38-MAPK substrate, MAPK-activated protein kinase 2 (MAPKAPK2), was activated approximately fourfold and 10 μM SB203580, a p38-MAPK inhibitor, abolished this activation. Phosphorylation of the MAPKAPK2 substrate, heat shock protein 25/27, was also increased. Using selective inhibitors, activation of the p38-MAPK pathway by endothelin-1 was shown to involve protein kinase C but not Gi/Go nor the extracellularly responsive kinase (ERK) pathway. SB203580 failed to inhibit the morphological changes associated with cardiac myocyte hypertrophy induced by endothelin-1 or phenylephrine between 4 and 24 h. However, it decreased the myofibrillar organization and cell profile at 48 h. In contrast, inhibition of the ERK cascade with PD98059 prevented the increase in myofibrillar organization but not cell profile. These data are not consistent with a role for the p38-MAPK pathway in the immediate induction of the morphological changes of hypertrophy but suggest that it may be necessary over a longer period to maintain the response. PMID:9679149
Cytotoxic and Antimicrobial Constituents from the Essential Oil of Lippia alba (Verbenaceae).
Santos, Nara O Dos; Pascon, Renata C; Vallim, Marcelo A; Figueiredo, Carlos R; Soares, Marisi G; Lago, João Henrique G; Sartorelli, Patricia
2016-08-12
Backgroud: Lippia alba (Verbenaceae) is a plant widely used in folk medicine to treat various diseases. The present work deals with the chemical composition of the crude essential oil extracted from leaves of L. alba and evaluation of its antimicrobial and cytotoxic activities. Methods: Leaves of L. alba were extracted by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) as well as by nuclear magnetic resonance (NMR) spectroscopy. Cytotoxic and antimicrobial activities of crude essential oil were evaluated in vitro using MTT and broth microdilution assays, respectively. Results: Chemical analysis afforded the identification of 39 substances corresponding to 99.45% of the total oil composition. Concerning the main compounds, monoterpenes nerol/geraniol and citral correspond to approximately 50% of crude oil. The cytotoxic activity of obtained essential oil against several tumor cell lines showed IC 50 values ranging from 45 to 64 µg/mL for B16F10Nex2 (murine melanoma) and A549 (human lung adenocarcinoma). In the antimicrobial assay, was observed that all tested yeast strains, except C. albicans , were sensitive to crude essential oil. MIC values were two to four-folds lower than those determined to bacterial strains. Conclusion: Analysis of chemical composition of essential oils from leaves of L. alba suggested a new chemotype nerol/geraniol and citral. Based in biological evidences, a possible application for studied oil as an antifungal in medicine, as well as in agriculture, is described.
Placental cadmium as an additional noninvasive bioindicator of active maternal tobacco smoking.
Piasek, Martina; Jurasović, Jasna; Sekovanić, Ankica; Brajenović, Nataša; Brčić Karačonji, Irena; Mikolić, Anja; Grgec, Antonija Sulimanec; Stasenko, Sandra
2016-01-01
Tobacco smoke (TS) is a mixture of chemicals that is known to exert carcinogenic and endocrine-disrupting effects, as well as adverse effects on various systems. In TS nicotine is the major alkaloid and cadmium (Cd) the most abundant metal ion. The aim of this investigation was to assess exposure to Cd attributed to TS in healthy postpartum subjects (mean age 28 years) after term vaginal delivery in a clinical hospital by determining metal levels in maternal blood, placenta, and cord blood in relation to nicotine in maternal hair (12-cm-long samples). Two study groups were compared based upon self-reporting data: smokers (n = 32; continual cigarette smoking 3 months before and 9 months during pregnancy) and nonsmokers (n = 54; including passive smokers whose parameters did not differ from unexposed nonsmokers). In smokers compared to nonsmokers maternal hair nicotine concentrations increased approximately sevenfold, while Cd levels rose fourfold in maternal blood and up to twofold in placenta. Significant positive correlations were noted between maternal hair nicotine and placental Cd, maternal hair nicotine and maternal blood Cd, and placental Cd and maternal blood Cd. Levels of cord blood Cd were low in both study groups (<0.1 ng/ml). Data indicate that Cd in placenta may serve as a noninvasive bioindicator in addition to commonly used noninvasive hair nicotine in maternal TS assessment, especially in cases where unavailable or inappropriate (short or chemically treated) hair samples occur.
NASA Astrophysics Data System (ADS)
Pineda, M.; Stamatakis, M.
2017-07-01
Modeling the kinetics of surface catalyzed reactions is essential for the design of reactors and chemical processes. The majority of microkinetic models employ mean-field approximations, which lead to an approximate description of catalytic kinetics by assuming spatially uncorrelated adsorbates. On the other hand, kinetic Monte Carlo (KMC) methods provide a discrete-space continuous-time stochastic formulation that enables an accurate treatment of spatial correlations in the adlayer, but at a significant computation cost. In this work, we use the so-called cluster mean-field approach to develop higher order approximations that systematically increase the accuracy of kinetic models by treating spatial correlations at a progressively higher level of detail. We further demonstrate our approach on a reduced model for NO oxidation incorporating first nearest-neighbor lateral interactions and construct a sequence of approximations of increasingly higher accuracy, which we compare with KMC and mean-field. The latter is found to perform rather poorly, overestimating the turnover frequency by several orders of magnitude for this system. On the other hand, our approximations, while more computationally intense than the traditional mean-field treatment, still achieve tremendous computational savings compared to KMC simulations, thereby opening the way for employing them in multiscale modeling frameworks.
Valero, Rosendo; Song, Lingchun; Gao, Jiali; Truhlar, Donald G.
2009-01-01
Diabatic models are widely employed for studying chemical reactivity in condensed phases and enzymes, but there has been little discussion of the pros and cons of various diabatic representations for this purpose. Here we discuss and contrast six different schemes for computing diabatic potentials for a charge rearrangement reaction. They include (i) the variational diabatic configurations (VDC) constructed by variationally optimizing individual valence bond structures and (ii) the consistent diabatic configurations (CDC) obtained by variationally optimizing the ground-state adiabatic energy, both in the nonorthogonal molecular orbital valence bond (MOVB) method, along with the orthogonalized (iii) VDC-MOVB and (iv) CDC-MOVB models. In addition, we consider (v) the fourfold way (based on diabatic molecular orbitals and configuration uniformity), and (vi) empirical valence bond (EVB) theory. To make the considerations concrete, we calculate diabatic electronic states and diabatic potential energies along the reaction path that connects the reactant and the product ion-molecule complexes of the gas-phase bimolecular nucleophilic substitution (SN2) reaction of 1,2-dichloethane (DCE) with acetate ion, which is a model reaction corresponding to the reaction catalyzed by haloalkane dehalogenase. We utilize ab initio block-localized molecular orbital theory to construct the MOVB diabatic states and ab initio multi-configuration quasidegenerate perturbation theory to construct the fourfold-way diabatic states; the latter are calculated at reaction path geometries obtained with the M06-2X density functional. The EVB diabatic states are computed with parameters taken from the literature. The MOVB and fourfold-way adiabatic and diabatic potential energy profiles along the reaction path are in qualitative but not quantitative agreement with each other. In order to validate that these wave-function-based diabatic states are qualitatively correct, we show that the reaction energy and barrier for the adiabatic ground state, obtained with these methods, agree reasonably well with the results of high-level calculations using the composite G3SX and G3SX(MP3) methods and the BMC-CCSD multi-coefficient correlation method. However, a comparison of the EVB gas-phase adiabatic ground-state reaction path with those obtained from MOVB and with the fourfold way reveals that the EVB reaction path geometries show a systematic shift towards the products region, and that the EVB lowest-energy path has a much lower barrier. The free energies of solvation and activation energy in water reported from dynamical calculations based on EVB also imply a low activation barrier in the gas phase. In addition, calculations of the free energy of solvation using the recently proposed SM8 continuum solvation model with CM4M partial atomic charges lead to an activation barrier in reasonable agreement with experiment only when the geometries and the gas-phase barrier are those obtained from electronic structure calculations, i.e., methods i–v. These comparisons show the danger of basing the diabatic states on molecular mechanics without the explicit calculation of electronic wave functions. Furthermore, comparison of schemes i–v with one another shows that significantly different quantitative results can be obtained by using different methods for extracting diabatic states from wave function calculations, and it is important for each user to justify the choice of diabatization method in the context of its intended use. PMID:20047005
Lakshmipriya, Thangavel; Gopinath, Subash C B; Tang, Thean-Hock
2016-01-01
Enzyme Linked Immunosorbent Assay (ELISA) is the gold standard assay for detecting and identifying biomolecules using antibodies as the probe. Improving ELISA is crucial for detecting disease-causing agents and facilitating diagnosis at the early stages of disease. Biotinylated antibody and streptavidin-conjugated horse radish peroxide (streptavidin-HRP) often are used with ELISA to enhance the detection of various kinds of targets. In the present study, we used a competition-based strategy in which we pre-mixed free biotin with streptavidin-HRP to generate high-performance system, as free biotin occupies some of the biotin binding sites on streptavidin, thereby providing more chances for streptavidin-HRP to bind with biotinylated antibody. ESAT-6, which is a protein secreted early during tuberculosis infection, was used as the model target. We found that 8 fM of free biotin mixed with streptavidin-HRP anchored the higher detection level of ESAT-6 by four-fold compared with detection without free biotin (only streptavidin-HRP), and the limit of detection of the new method was 250 pM. These results suggest that biotin-streptavidin competition can be used to improve the diagnosis of analytes in other types of sensors.
Lakshmipriya, Thangavel; Gopinath, Subash C. B.; Tang, Thean-Hock
2016-01-01
Enzyme Linked Immunosorbent Assay (ELISA) is the gold standard assay for detecting and identifying biomolecules using antibodies as the probe. Improving ELISA is crucial for detecting disease-causing agents and facilitating diagnosis at the early stages of disease. Biotinylated antibody and streptavidin-conjugated horse radish peroxide (streptavidin-HRP) often are used with ELISA to enhance the detection of various kinds of targets. In the present study, we used a competition-based strategy in which we pre-mixed free biotin with streptavidin-HRP to generate high-performance system, as free biotin occupies some of the biotin binding sites on streptavidin, thereby providing more chances for streptavidin-HRP to bind with biotinylated antibody. ESAT-6, which is a protein secreted early during tuberculosis infection, was used as the model target. We found that 8 fM of free biotin mixed with streptavidin-HRP anchored the higher detection level of ESAT-6 by four-fold compared with detection without free biotin (only streptavidin-HRP), and the limit of detection of the new method was 250 pM. These results suggest that biotin-streptavidin competition can be used to improve the diagnosis of analytes in other types of sensors. PMID:26954237
Chemotactic synthetic vesicles: Design and applications in blood-brain barrier crossing.
Joseph, Adrian; Contini, Claudia; Cecchin, Denis; Nyberg, Sophie; Ruiz-Perez, Lorena; Gaitzsch, Jens; Fullstone, Gavin; Tian, Xiaohe; Azizi, Juzaili; Preston, Jane; Volpe, Giorgio; Battaglia, Giuseppe
2017-08-01
In recent years, scientists have created artificial microscopic and nanoscopic self-propelling particles, often referred to as nano- or microswimmers, capable of mimicking biological locomotion and taxis. This active diffusion enables the engineering of complex operations that so far have not been possible at the micro- and nanoscale. One of the most promising tasks is the ability to engineer nanocarriers that can autonomously navigate within tissues and organs, accessing nearly every site of the human body guided by endogenous chemical gradients. We report a fully synthetic, organic, nanoscopic system that exhibits attractive chemotaxis driven by enzymatic conversion of glucose. We achieve this by encapsulating glucose oxidase alone or in combination with catalase into nanoscopic and biocompatible asymmetric polymer vesicles (known as polymersomes). We show that these vesicles self-propel in response to an external gradient of glucose by inducing a slip velocity on their surface, which makes them move in an extremely sensitive way toward higher-concentration regions. We finally demonstrate that the chemotactic behavior of these nanoswimmers, in combination with LRP-1 (low-density lipoprotein receptor-related protein 1) targeting, enables a fourfold increase in penetration to the brain compared to nonchemotactic systems.
Yi, Dengxia; Ma, Lin; Lin, Min; Li, Cong
2018-07-01
The glyphosate-resistant gene, GR79Ms, was successfully introduced into the genome of alfalfa. The transgenic events may serve as novel germplasm resources in alfalfa breeding. Weed competition can reduce the alfalfa yield, generating new alfalfa germplasm with herbicide resistance is essential. To obtain transgenic alfalfa lines with glyphosate resistance, a new synthetic glyphosate-resistant gene GR79Ms encoding 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) was introduced into alfalfa germplasm by Agrobacterium tumefaciens-mediated transformation. In total, 67 transformants were obtained. PCR and Southern blot analyses confirmed that GR79Ms was successfully inserted into the genome of alfalfa. Reverse transcription-PCR and western blot analyses further demonstrated the expression of GR79Ms and its product, GR79Ms EPSPS. Moreover, two homozygous transgenic lines were developed in the T 2 generation by means of molecular-assisted selection. Herbicide tolerance spray tests showed that the transgenic plants T 0 -GR1, T 0 -GR2, T 0 -GR3 and two homozygous lines were able to tolerate fourfold higher commercial usage of glyphosate than non-transgenic plants.
Watershed responses to Amazon soya bean cropland expansion and intensification
Neill, Christopher; Coe, Michael T.; Riskin, Shelby H.; Krusche, Alex V.; Elsenbeer, Helmut; Macedo, Marcia N.; McHorney, Richard; Lefebvre, Paul; Davidson, Eric A.; Scheffler, Raphael; Figueira, Adelaine Michela e Silva; Porder, Stephen; Deegan, Linda A.
2013-01-01
The expansion and intensification of soya bean agriculture in southeastern Amazonia can alter watershed hydrology and biogeochemistry by changing the land cover, water balance and nutrient inputs. Several new insights on the responses of watershed hydrology and biogeochemistry to deforestation in Mato Grosso have emerged from recent intensive field campaigns in this region. Because of reduced evapotranspiration, total water export increases threefold to fourfold in soya bean watersheds compared with forest. However, the deep and highly permeable soils on the broad plateaus on which much of the soya bean cultivation has expanded buffer small soya bean watersheds against increased stormflows. Concentrations of nitrate and phosphate do not differ between forest or soya bean watersheds because fixation of phosphorus fertilizer by iron and aluminium oxides and anion exchange of nitrate in deep soils restrict nutrient movement. Despite resistance to biogeochemical change, streams in soya bean watersheds have higher temperatures caused by impoundments and reduction of bordering riparian forest. In larger rivers, increased water flow, current velocities and sediment flux following deforestation can reshape stream morphology, suggesting that cumulative impacts of deforestation in small watersheds will occur at larger scales. PMID:23610178
Evaluating landfill aftercare strategies: A life cycle assessment approach.
Turner, David A; Beaven, Richard P; Woodman, Nick D
2017-05-01
This study investigates the potential impacts caused by the loss of active environmental control measures during the aftercare period of landfill management. A combined mechanistic solute flow model and life cycle assessment (LCA) approach was used to evaluate the potential impacts of leachate emissions over a 10,000year time horizon. A continuum of control loss possibilities occurring at different times and for different durations were investigated for four different basic aftercare scenarios, including a typical aftercare scenario involving a low permeability cap and three accelerated aftercare scenarios involving higher initial infiltration rates. Assuming a 'best case' where control is never lost, the largest potential impacts resulted from the typical aftercare scenario. The maximum difference between potential impacts from the 'best case' and the 'worst case', where control fails at the earliest possible point and is never reinstated, was only a fourfold increase. This highlights potential deficiencies in standard life cycle impact assessment practice, which are discussed. Nevertheless, the results show how the influence of active control loss on the potential impacts of landfilling varies considerably depending on the aftercare strategy used and highlight the importance that leachate treatment efficiencies have upon impacts. Copyright © 2016 Elsevier Ltd. All rights reserved.
Strong Purifying Selection at Synonymous Sites in D. melanogaster
Lawrie, David S.; Messer, Philipp W.; Hershberg, Ruth; Petrov, Dmitri A.
2013-01-01
Synonymous sites are generally assumed to be subject to weak selective constraint. For this reason, they are often neglected as a possible source of important functional variation. We use site frequency spectra from deep population sequencing data to show that, contrary to this expectation, 22% of four-fold synonymous (4D) sites in Drosophila melanogaster evolve under very strong selective constraint while few, if any, appear to be under weak constraint. Linking polymorphism with divergence data, we further find that the fraction of synonymous sites exposed to strong purifying selection is higher for those positions that show slower evolution on the Drosophila phylogeny. The function underlying the inferred strong constraint appears to be separate from splicing enhancers, nucleosome positioning, and the translational optimization generating canonical codon bias. The fraction of synonymous sites under strong constraint within a gene correlates well with gene expression, particularly in the mid-late embryo, pupae, and adult developmental stages. Genes enriched in strongly constrained synonymous sites tend to be particularly functionally important and are often involved in key developmental pathways. Given that the observed widespread constraint acting on synonymous sites is likely not limited to Drosophila, the role of synonymous sites in genetic disease and adaptation should be reevaluated. PMID:23737754
NASA Astrophysics Data System (ADS)
Ma, Liang-Cai; Ma, Ling; Zhang, Jian-Min
2017-07-01
By using first-principles calculations based on density-functional theory, the stability, magnetic and electronic properties of Fe and Co monoatomic chains encapsulated into copper nanotube are systematically investigated. The binding energies of the hybrid structures are remarkably higher than those of corresponding freestanding TM chains, indicating the TM chains are significantly stabilized after encapsulating into copper nanotube. The formed bonds between outer Cu and inner TM atoms show some degree of covalent bonding character. The magnetic ground states of Fe@CuNW and Co@CuNW hybrid structures are ferromagnetic, and both spin and orbital magnetic moments of inner TM atoms have been calculated. The magnetocrystalline anisotropy energies (MAE) of the hybrid structures are enhanced by nearly fourfold compared to those of corresponding freestanding TM chains, indicating that the hybrid structures can be used in ultrahigh density magnetic storage. Furthermore, the easy magnetization axis switches from that along the axis in freestanding Fe chain to that perpendicular to the axis in Fe@CuNT hybrid structure. The large spin polarization at the Fermi level also makes the hybrid systems interesting as good potential materials for spintronic devices.
RETRACTED ARTICLE: Microstructure and strengthening mechanism of Ni3Al intermetallic compound
NASA Astrophysics Data System (ADS)
Oh, Chang-Sup; Han, Chang-Suk
2013-09-01
Structural studies have been performed on precipitation hardening found in Ni3Al-base ordered alloys using transmission electron microscopy. The γ' phase hardens appreciably by the fine precipitation of disordered γ. The strength of γ' increases over the temperature range of experiment by the precipitation of fine γ particles. The peak temperature where a maximum strength was obtained shifted to higher temperature. Superlattice dislocations dissociate into fourfold Shockley partial dislocations in a uniform supersaturated solid solution of the γ' phase. Dislocations are attracted into the disordered γ phase and dissociate further in the particles. At any stage of aging, dislocations cut through the particles and the Orowan bypassing process does not occur even in the overaged stage of this alloy system. When the applied stress is removed, the dislocations make cross slip into (010) plane, while those in γ precipitates remain on the (111) primary slip plane. The increase of high temperature strength in γ' containing γ precipitates is due to the restraint of cross slip of dislocations from (111) to (010) by the dispersion of disordered γ particles. The orientation dependence of strength is decreased by the fine precipitation of a disordered γ phase.
Ibrahim, Yomna I.; Ninnis, Janet R.; Hopper, Andrew O.; Deming, Douglas D.; Zhang, Amy X.; Herring, Jason L.; Sowers, Lawrence C.; McMahon, Timothy J.; Power, Gordon G.; Blood, Arlin B.
2011-01-01
Objective To measure the circulating concentrations of nitric oxide (NO) adducts with NO bioactivity following inhaled NO therapy in infants with pulmonary hypertension. Study design In this single center study five sequential blood samples were collected from infants with pulmonary hypertension before, during and after therapy with iNO (n=17). Samples were collected from a control group of hospitalized infants without pulmonary hypertension (n=16) and from healthy adults for comparison (n=12). Results After beginning iNO (20 ppm) whole blood nitrite increased about two-fold within two hours (P<0.01). Whole blood nitrate increased to four-fold higher than baseline during treatment with 20ppm iNO (P<0.01). S-nitrosohemoglobin (SNO-Hb) increased measurably after beginning iNO (P<0.01) whereas iron nitrosyl hemoglobin and total Hb-bound NO-species compounds did not change. Conclusion Treatment of pulmonary hypertensive infants with iNO results in increases in nitrite, nitrate, and SNO-Hb in circulating blood. We speculate that these compounds may be carriers of NO bioactivity throughout the body and account for peripheral effects of iNO in the brain, heart and other organs. PMID:21907348
Silent spread of highly pathogenic Avian Influenza H5N1 virus amongst vaccinated commercial layers.
Poetri, Okti Nadia; Van Boven, Michiel; Claassen, Ivo; Koch, Guus; Wibawan, I Wayan; Stegeman, Arjan; Van den Broek, Jan; Bouma, Annemarie
2014-12-01
The aim of this study was to determine whether a single vaccination of commercial layer type chickens with an inactivated vaccine containing highly pathogenic avian influenza virus strain H5N1 A/chicken/Legok/2003, carried out on the farm, was sufficient to protect against infection with the homologous virus strain. A transmission experiment was carried out with pairs of chicken of which one was inoculated with H5N1 virus and the other contact-exposed. Results showed that the majority of the vaccinated birds developed haemagglutination inhibition (HI) titres below 4log2. No clinical signs were observed in the vaccinated birds and virus shedding was limited. However, nearly all vaccinated birds showed a four-fold or higher increase of HI titres after challenge or contact-exposure, which is an indication of infection. This implies that virus transmission most likely has occurred. This study showed that a single vaccination applied under field conditions induced clinical protection, but was insufficient to induce protection against virus transmission, suggesting that silent spread of virus in vaccinated commercial flocks may occur. Copyright © 2014 Elsevier Ltd. All rights reserved.
Teulier, Loic; Dégletagne, Cyril; Rey, Benjamin; Tornos, Jérémy; Keime, Céline; de Dinechin, Marc; Raccurt, Mireille; Rouanet, Jean-Louis; Roussel, Damien; Duchamp, Claude
2012-06-22
The passage from shore to marine life of juvenile penguins represents a major energetic challenge to fuel intense and prolonged demands for thermoregulation and locomotion. Some functional changes developed at this crucial step were investigated by comparing pre-fledging king penguins with sea-acclimatized (SA) juveniles (Aptenodytes patagonicus). Transcriptomic analysis of pectoralis muscle biopsies revealed that most genes encoding proteins involved in lipid transport or catabolism were upregulated, while genes involved in carbohydrate metabolism were mostly downregulated in SA birds. Determination of muscle enzymatic activities showed no changes in enzymes involved in the glycolytic pathway, but increased 3-hydroxyacyl-CoA dehydrogenase, an enzyme of the β-oxidation pathway. The respiratory rates of isolated muscle mitochondria were much higher with a substrate arising from lipid metabolism (palmitoyl-L-carnitine) in SA juveniles than in terrestrial controls, while no difference emerged with a substrate arising from carbohydrate metabolism (pyruvate). In vivo, perfusion of a lipid emulsion induced a fourfold larger thermogenic effect in SA than in control juveniles. The present integrative study shows that fuel selection towards lipid oxidation characterizes penguin acclimatization to marine life. Such acclimatization may involve thyroid hormones through their nuclear beta receptor and nuclear coactivators.
Methyl angolensate changes in Khaya ivorensis after fungal infection.
Reche, Karine V G; de Souza, Gezimar D; Trapp, Marília A; Rodrigues-Filho, Edson; Silva, Sebastião C; Fernandes, João B; Vieira, Paulo C; Muller, Manfred W; da Silva, M Fátima das G F
2009-12-01
Khaya ivorensis with and without symptoms of stem and branch cankers, caused by Botryosphaeria rhodina were examined in order to determine whether the secondary metabolites in this plant were associated with a chemical defense response. This study provides evidence that the limonoid methyl angolensate (MA) is present at higher concentrations in K. ivorensis with symptoms of stem cankers rather than in the plants without symptoms. A rapid, sensitive and selective HPLC-ESI-MS/MS method (using selected reaction monitoring--SRM--mode) was developed for quantification of MA in all aerials parts of such plants, with a good linearity over a range of 0.1-20.0 g/kg, with r(2)>0.996+/-6.1%. The limits of detection (LOD) and quantification (LOQ) were less than 0.03 g/kg and 0.08 g/kg, respectively. Relative Standard Deviations (RSDs) ranged from 1.7% to 19.2% for all matrices. While the MA concentration did not change in the stem bark, its amounts increased nearly fourfold in stems and by 20% in leaves, when plants with symptoms were compared with those without symptoms. These data suggest that MA plays a role in plant-pathogen interactions, probably as a phytoanticipin.
Chemotactic synthetic vesicles: Design and applications in blood-brain barrier crossing
Joseph, Adrian; Contini, Claudia; Cecchin, Denis; Nyberg, Sophie; Ruiz-Perez, Lorena; Gaitzsch, Jens; Fullstone, Gavin; Tian, Xiaohe; Azizi, Juzaili; Preston, Jane; Volpe, Giorgio; Battaglia, Giuseppe
2017-01-01
In recent years, scientists have created artificial microscopic and nanoscopic self-propelling particles, often referred to as nano- or microswimmers, capable of mimicking biological locomotion and taxis. This active diffusion enables the engineering of complex operations that so far have not been possible at the micro- and nanoscale. One of the most promising tasks is the ability to engineer nanocarriers that can autonomously navigate within tissues and organs, accessing nearly every site of the human body guided by endogenous chemical gradients. We report a fully synthetic, organic, nanoscopic system that exhibits attractive chemotaxis driven by enzymatic conversion of glucose. We achieve this by encapsulating glucose oxidase alone or in combination with catalase into nanoscopic and biocompatible asymmetric polymer vesicles (known as polymersomes). We show that these vesicles self-propel in response to an external gradient of glucose by inducing a slip velocity on their surface, which makes them move in an extremely sensitive way toward higher-concentration regions. We finally demonstrate that the chemotactic behavior of these nanoswimmers, in combination with LRP-1 (low-density lipoprotein receptor–related protein 1) targeting, enables a fourfold increase in penetration to the brain compared to nonchemotactic systems. PMID:28782037
Goldstein, F W; Acar, J F
1996-07-01
One thousand, eight hundred and fifty-six Streptococcus pneumoniae strains, collected in 1992 and 1993 from 15 centres in Western Europe and USA were tested for susceptibility to 16 antibiotics. The overall resistance to penicillin was 23% (range 6-54%), with the highest prevalences in Madrid, Barcelona, Toulouse and Cleveland. Seven centres reported low-level penicillin resistance only. Amoxycillin was more active than ceftriaxone against strains with intermediate resistance to penicillin, and at least four-fold more active than cefuroxime; cefaclor and cefixime had poor activity. Against penicillin-resistant strains, ceftriaxone was slightly more active than amoxycillin, cefuroxime exhibited borderline activity and cefixime and cefaclor were inactive. Ten strains fully susceptible to penicillin had MICs of ceftriaxone > or = 0.1 mg/L; this may represent a first step towards the development of cephalosporin resistance. With the exception of fluoroquinolones, resistance to non-beta-lactam antibiotics (chloramphenicol, doxycycline, co-trimoxazole, erythromycin, clarithromycin and azithromycin) was considerably higher in penicillin-resistant strains compared with penicillin-susceptible isolates. Erythromycin-resistant isolates were also resistant to the other macrolides tested.
An epidemiological study of rotator cuff pathology using The Health Improvement Network database.
White, J J E; Titchener, A G; Fakis, A; Tambe, A A; Hubbard, R B; Clark, D I
2014-03-01
Little is known about the incidence of rotator cuff pathology or its demographic associations in the general population. We undertook a large epidemiological study of rotator cuff pathology in the United Kingdom using The Health Improvement Network (THIN) database. The incidence of rotator cuff pathology was 87 per 100,000 person-years. It was more common in women than in men (90 cases per 100,000 person-years in women and 83 per 100,000 person-years in men; p < 0.001). The highest incidence of 198 per 100,000 person-years was found in those aged between 55 and 59 years. The regional distribution of incidence demonstrated an even spread across 13 UK health authorities except Wales, where the incidence was significantly higher (122 per 100,000 person-years; p < 0.001). The lowest socioeconomic group had the highest incidence (98 per 100,000 person-years). The incidence has risen fourfold since 1987 and as of 2006 shows no signs of plateauing. This study represents the largest general population study of rotator cuff pathology reported to date. The results obtained provide an enhanced appreciation of the epidemiology of rotator cuff pathology and may help to direct future upper limb orthopaedic services.
Benzene degradation in a denitrifying biofilm reactor: activity and microbial community composition.
van der Waals, Marcelle J; Atashgahi, Siavash; da Rocha, Ulisses Nunes; van der Zaan, Bas M; Smidt, Hauke; Gerritse, Jan
2017-06-01
Benzene is an aromatic compound and harmful for the environment. Biodegradation of benzene can reduce the toxicological risk after accidental or controlled release of this chemical in the environment. In this study, we further characterized an anaerobic continuous biofilm culture grown for more than 14 years on benzene with nitrate as electron acceptor. We determined steady state degradation rates, microbial community composition dynamics in the biofilm, and the initial anaerobic benzene degradation reactions. Benzene was degraded at a rate of 0.15 μmol/mg protein/day and a first-order rate constant of 3.04/day which was fourfold higher than rates reported previously. Bacteria belonging to the Peptococcaceae were found to play an important role in this anaerobic benzene-degrading biofilm culture, but also members of the Anaerolineaceae were predicted to be involved in benzene degradation or benzene metabolite degradation based on Illumina MiSeq analysis of 16S ribosomal RNA genes. Biomass retention in the reactor using a filtration finger resulted in reduction of benzene degradation capacity. Detection of the benzene carboxylase encoding gene, abcA, and benzoic acid in the culture vessel indicated that benzene degradation proceeds through an initial carboxylation step.
Bigger is not always better; How cold-water corals outgrow themselves
NASA Astrophysics Data System (ADS)
Mienis, Furu; Duineveld, Gerard; Lavaleye, Marc; Mohn, Christian; Van Haren, Hans
2015-04-01
Cold-water coral (CWC) framework acts as a sediment trap and as a result kilometres long and up to 360m high mound structures have formed on the SE Rockall Bank. Earlier observations showed that most of the mounds have their summits around 550 m water depth and summits have been reported as being covered with living coral. Pelagia cruises in 2012 and 2013 revealed completely new insights in mound development. Video transects across mounds with different morphology showed that summits of the highest and largest mounds are presently not covered by living coral as opposed to smaller and lower mounds which are covered with a thriving living coral framework. This is also expressed by the vertical mound growth rate measured in sediment cores showing fourfold higher sedimentation rates during the Holocene on small mounds compared to highest mounds. Measurements in the water column with CTD and near-bottom with benthic landers and thermistor string showed that turbulence is likely the most important factor influencing nutrient and food supply and thus coral growth. It seems that the large mounds have outgrown themselves and that their relatively large size and flat summits are limiting turbulence, thereby limiting coral and mound growth.
NASA Astrophysics Data System (ADS)
Lim, Sangyong; Yun, Hyejeong; Joe, Minho; Kim, Dongho
2009-07-01
A series of repeated exposures to γ-radiation with intervening outgrowth of survivors was used to develop radioresistant cultures of Moraxella osloensis that have been recognized as potential pathogenic microorganism. The D10 value of the radiation-resistant strain, 5.903±0.006 kGy, was increased by four-fold compared to the parent wild-type strain, 1.637±0.004 kGy. Since most strains of M. osloensis are sensitive to penicillin, we have surveyed the sensitivity of radiation-resistant strain to this antibiotic. When the optical density was monitored after the addition of penicillin G, the radioresistant strain appeared to be more resistant to only a low concentration of penicillin G (0.5 U/ml) than the parent strain. Interestingly, however, there was no apparent difference in the number of viable cells between both strains. Scanning electron microscope data showed that the resistance cells were generally larger than the parent cells, suggesting that this increase in size may cause a higher optical density of radioresistant cells. In conclusion, radiation mutation does not affect the penicillin resistance of M. osloensis.
Gilson, Rebecca C; Black, Kvar C L; Lane, Daniel D; Achilefu, Samuel
2017-08-28
Photodynamic therapy (PDT) is widely used to treat diverse diseases, but its dependence on oxygen to produce cytotoxic reactive oxygen species (ROS) diminishes the therapeutic effect in a hypoxic environment, such as solid tumors. Herein, we developed a ROS-producing hybrid nanoparticle-based photosensitizer capable of maintaining high levels of ROS under both normoxic and hypoxic conditions. Conjugation of a ruthenium complex (N3) to a TiO 2 nanoparticle afforded TiO 2 -N3. Upon exposure of TiO 2 -N3 to light, the N3 injected electrons into TiO 2 to produce three- and four-fold more hydroxyl radicals and hydrogen peroxide, respectively, than TiO 2 at 160 mmHg. TiO 2 -N3 maintained three-fold higher hydroxyl radicals than TiO 2 under hypoxic conditions via N3-facilitated electron-hole reduction of adsorbed water molecules. The incorporation of N3 transformed TiO 2 from a dual type I and II PDT agent to a predominantly type I photosensitizer, irrespective of the oxygen content. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Solomatova, Natalia V.; Jackson, Jennifer M.; Sturhahn, Wolfgang
The physical properties of silicate melts within Earth's mantle affect the chemical and thermal evolution of its interior. Chemistry and coordination environments affect such properties. We have measured the hyperfine parameters of iron-bearing rhyolitic and basaltic glasses up to ~120 GPa and ~100 GPa, respectively, in a neon pressure medium using time domain synchrotron Mössbauer spectroscopy. The spectra for rhyolitic and basaltic glasses are well explained by three high-spin Fe2+-like sites with distinct quadrupole splittings. Absence of detectable ferric iron was confirmed with optical absorption spectroscopy. The sites with relatively high and intermediate quadrupole splittings are likely a result ofmore » fivefold and sixfold coordination environments of ferrous iron that transition to higher coordination with increasing pressure. The ferrous site with a relatively low quadrupole splitting and isomer shift at low pressures may be related to a fourfold or a second fivefold ferrous iron site, which transitions to higher coordination in basaltic glass, but likely remains in low coordination in rhyolitic glass. These results indicate that iron experiences changes in its coordination environment with increasing pressure without undergoing a high-spin to low-spin transition. We compare our results to the hyperfine parameters of silicate glasses of different compositions. With the assumption that coordination environments in silicate glasses may serve as a good indicator for those in a melt, this study suggests that ferrous iron in chemically complex silicate melts likely exists in a high-spin state throughout most of Earth's mantle.« less
Detection of trace microcystin-LR on a 20 MHz QCM sensor coated with in situ self-assembled MIPs.
He, Hao; Zhou, Lianqun; Wang, Yi; Li, Chuanyu; Yao, Jia; Zhang, Wei; Zhang, Qingwen; Li, Mingyu; Li, Haiwen; Dong, Wen-fei
2015-01-01
A 20 MHz quartz crystal microbalance (QCM) sensor coated with in situ self-assembled molecularly imprinted polymers (MIPs) was presented for the detection of trace microcystin-LR (MC-LR) in drinking water. The sensor performance obtained using the in situ self-assembled MIPs was compared with traditionally synthesized MIPs on 20 MHz and normal 10 MHz QCM chip. The results show that the response increases by more than 60% when using the in situ self-assembly method compared using the traditionally method while the 20 MHz QCM chip provides four-fold higher response than the 10 MHz one. Therefore, the in situ self-assembled MIPs coated on a high frequency QCM chip was used in the sensor performance test to detect MC-LR in tap water. It showed a limit of detection (LOD) of 0.04 nM which is lower than the safety guideline level (1 nM MC-LR) of drinking water in China. The low sensor response to other analogs indicated the high specificity of the sensor to MC-LR. The sensor showed high stability and low signal variation less than 2.58% after regeneration. The lake water sample analysis shows the sensor is possible for practical use. The combination of the higher frequency QCM with the in situ self-assembled MIPs provides a good candidate for the detection of other small molecules. Copyright © 2014 Elsevier B.V. All rights reserved.
Cross-Sectional And Longitudinal Uncertainty Propagation In Drinking Water Risk Assessment
NASA Astrophysics Data System (ADS)
Tesfamichael, A. A.; Jagath, K. J.
2004-12-01
Pesticide residues in drinking water can vary significantly from day to day. However, drinking water quality monitoring performed under the Safe Drinking Water Act (SDWA) at most community water systems (CWSs) is typically limited to four data points per year over a few years. Due to limited sampling, likely maximum residues may be underestimated in risk assessment. In this work, a statistical methodology is proposed to study the cross-sectional and longitudinal uncertainties in observed samples and their propagated effect in risk estimates. The methodology will be demonstrated using data from 16 CWSs across the US that have three independent databases of atrazine residue to estimate the uncertainty of risk in infants and children. The results showed that in 85% of the CWSs, chronic risks predicted with the proposed approach may be two- to four-folds higher than that predicted with the current approach, while intermediate risks may be two- to three-folds higher in 50% of the CWSs. In 12% of the CWSs, however, the proposed methodology showed a lower intermediate risk. A closed-form solution of propagated uncertainty will be developed to calculate the number of years (seasons) of water quality data and sampling frequency needed to reduce the uncertainty in risk estimates. In general, this methodology provided good insight into the importance of addressing uncertainty of observed water quality data and the need to predict likely maximum residues in risk assessment by considering propagation of uncertainties.
Bernat, Przemysław; Paraszkiewicz, Katarzyna; Siewiera, Paulina; Moryl, Magdalena; Płaza, Grażyna; Chojniak, Joanna
2016-10-01
Urinary tract infections are a common disease in humans. Therefore, new methods are needed to destroy biofilms that are formed by uropathogens. Iturin A lipopeptides (LPs) C14 and C15 are potent biosurfactants synthetized by the Bacillus subtilis I'1a strain. The biological activity of extracted LPs was confirmed by examining extracts from I'1a cultures against uropathogenic bacteria that had been isolated from biofilms on urinary catheters. Compared with cultures of DSM 3257, which produce surfactin at a relatively low level, the extract obtained from strain I'1a exhibited a greater inhibitory effect against both planktonic and sessile forms of Escherichia coli, Serratia marcescens, Enterobacter cloacae, Proteus mirabilis, Citrobacter freundii and Enterococcus faecalis. Moreover, cyclic LP biosurfactants may disturb the integrity of cytoplasmic membranes; therefore, we investigated the effects of synthetized LPs on fatty acids and phospholipids of B. subtilis. LPs and lipids were analyzed using GC-MS, LC-MS/MS and MALDI-TOF/TOF techniques. Compared with B. subtilis DSM 3257, membranes of the I'1a strain were characterized by an increased amount of anteiso fatty acids and a ten-fold higher ratio of phosphatidylglycerol (PG)-to-phosphatidylethanolamine (PE). Interestingly, in cultures of B. subtilis DSM 3257 supplemented with LP extracts of the I'1a strain, the PG-to-PE ratio was fourfold higher, and the amount of anteiso fatty acids was also increased.
Dyukova, Tatyana V; Druzhko, Anna B
2010-01-01
The process of photoinduced hydroxylaminolysis has been re-examined in different bacteriorhodopsin (BR)-based media using O-substituted hydroxylamines, in particular, O-(4-nitrobenzyl) hydroxylamine hydrochloride (NBHA), O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride (FBHA) and O-(t-butyl) hydroxylamine hydrochloride (BHA). Both wild type (WT) and D96N BR-based gelatine films and gels were studied. The expected increase in the bleaching rate of BR in gelatin films by using O-substituted hydroxylamines in place of HA was not achieved. On the other hand, it was shown that in gels HA derivatives NBHA and FBHA (as against HA itself) do provide about three- to four-fold higher bleaching rate. By contrast to that in films, D96N BR in gels demonstrates more effective bleaching as compared to WT BR. The plausible interpretation for the results is discussed in frames of reduced mobilities of large-sized molecules of O-substituted hydroxylamines in dehydrated media. FBHA- or NBHA-modified gels possess higher photosensitivity both with D96N and WT BR (as compared with that for HA-modified gels) and offer a potentiality for application as an irreversible-recording medium. As anticipated, it is specifically D96N BR gel modified with FBHA that may present a promising medium suitable for write-once recording thus extending the range of recording materials in the optical processing field. © 2010 The Authors. Journal Compilation. The American Society of Photobiology.
Jalal, Shah; Ciofu, Oana; Høiby, Niels; Gotoh, Naomasa; Wretlind, Bengt
2000-01-01
Twenty P. aeruginosa isolates were collected from six cystic fibrosis (CF) patients, aged 27 to 33, in 1994 (9 isolates) and 1997 (11 isolates) at the CF Center, Copenhagen, Denmark, and were typed by pulse-field gel electrophoresis (PFGE) or ribotyping. Five of the patients had isolates with the same PFGE or ribotyping patterns in 1997 as in 1994, and ciprofloxacin had a two- to fourfold higher MIC for the isolates collected in 1997 than those from 1994. Genomic DNA was amplified for gyrA, parC, mexR, and nfxB by PCR and sequenced. Eleven isolates had mutations in gyrA, seven isolates had mutations at codon 83 (Thr to Ile), and four isolates had mutations at codon 87 (Asp to Asn or Tyr). Sixteen isolates had mutations in nfxB at codon 82 (Arg to Leu). Increased amounts of OprN were found in six isolates and OprJ in eight isolates as determined by immunoblotting. No isolates had mutations in parC or mexR. Six isolates had mutations in efflux pumps without gyrA mutations. The average number of mutations was higher in isolates from 1997 than in those from 1994. The results also suggested that efflux resistance mechanisms are more common in isolates from CF patients than in strains from urine and wounds from non-CF patients, in which mutations in gyrA and parC dominate (S. Jalal and B. Wretlind, Microb. Drug Resist. 4:257–261, 1998). PMID:10681343
Virokannas, H
1995-05-01
31 railway workers and 32 lumberjacks were examined to compare the dose-response relation between the exposure to two types of hand-arm vibration and the sensory disturbances in peripheral nerves as evaluated by the vibration perception thresholds (VPTs). Clinical examinations were carried out that included measurements of the VPTs, and electroneuromyography (ENMG), and an inquiry to confirm the use of vibrating tools. Diseases of the central nervous system and neuropathies were checked by inquiry and a clinical examination, diabetes was excluded by a blood sample analysis, and the subjects with carpal tunnel syndrome confirmed with ENMG were excluded from the study. Lifetime use of hand held tamping machines (railway workers) and chain saws (lumberjacks) had a significant correlation with the VPTs at frequencies from 32 to 500 Hz. The increase of the VPTs (250 Hz) in relation to use of vibrating tools was 1.8-fold higher on average in the whole group and 2.3-fold higher in the young (< 45) railway workers who had used hand held tamping machines, than in the corresponding groups of lumberjacks, who had used chain saws, whereas the frequency weighted acceleration of vibration in tamping machines was fourfold. There was a significant dose-response relation between the exposure to hand-arm vibration and the VPTs. The VPTs as a function of the frequency weighted acceleration of vibration and the exposure to vibration gave promising results for assessment of the risk of damage to sensory nerves induced by vibration.
Miescher, S M; Huber, T M; Kühne, M; Lieby, P; Snydman, D R; Vensak, J L; Berger, M
2015-07-01
To evaluate standard intravenous immunoglobulin (IVIG) as an alternative to intravenous cytomegalovirus hyperimmune immunoglobulin (CMVIG) for prophylaxis and therapy of cytomegalovirus (CMV) disease, we measured the ELISA and neutralizing titres of CMV-specific antibodies in CMVIG and IVIG preparations. Anti-CMV-IgG ELISA and neutralizing titres (fibroblast-based test) in CMVIG CG (Cytogam®, n = 20), CMVIG CT (Cytotect® CP, n = 3), IVIG P (Privigen®, n = 32) and IVIG K/G (Kiovig®/Gammagard®, n = 5) were compared, and IgG subclasses 1-4 were determined by nephelometry. Cytomegalovirus hyperimmune immunoglobulins contained more than fourfold higher CMV ELISA and CMV-neutralizing activity per gram of IgG than the standard IVIGs. Pooled data for all four products showed a significant correlation between anti-CMV-IgG ELISA and neutralizing titres (r = 0·93, P < 0·001). There was a good correlation between the IgG3 content and CMV-neutralizing antibodies amongst lots of CMVIGs (r = 0·91, P = 0·01), but this did not extend to the IVIGs. CMVIG CG contained the highest CMV-neutralizing activity (3497 ± 395 PEIU/g IgG) of any product tested. The higher anti-CMV neutralization capacity of CMVIG per gram of IgG vs. standard IVIG suggests that standard IVIGs are not equivalent to or interchangeable with CMVIG. © 2015 The Authors. Vox Sanguinis published by John Wiley & Sons Ltd on behalf of International Society of Blood Transfusion.
Phase angle, frailty and mortality in older adults.
Wilhelm-Leen, Emilee R; Hall, Yoshio N; Horwitz, Ralph I; Chertow, Glenn M
2014-01-01
Frailty is a multidimensional phenotype that describes declining physical function and a vulnerability to adverse outcomes in the setting of physical stress such as illness or hospitalization. Phase angle is a composite measure of tissue resistance and reactance measured via bioelectrical impedance analysis (BIA). Whether phase angle is associated with frailty and mortality in the general population is unknown. To evaluate associations among phase angle, frailty and mortality. Population-based survey. Third National Health and Nutritional Examination Survey (1988-1994). In all, 4,667 persons aged 60 and older. Frailty was defined according to a set of criteria derived from a definition previously described and validated. Narrow phase angle (the lowest quintile) was associated with a four-fold higher odds of frailty among women and a three-fold higher odds of frailty among men, adjusted for age, sex, race-ethnicity and comorbidity. Over a 12-year follow-up period, the adjusted relative hazard for mortality associated with narrow phase angle was 2.4 (95 % confidence interval [95 % CI] 1.8 to 3.1) in women and 2.2 (95 % CI 1.7 to 2.9) in men. Narrow phase angle was significantly associated with mortality even among participants with little or no comorbidity. Analyses of BIA and frailty were cross-sectional; BIA was not measured serially and incident frailty during follow-up was not assessed. Participants examined at home were excluded from analysis because they did not undergo BIA. Narrow phase angle is associated with frailty and mortality independent of age and comorbidity.
Nada, Reham M; Abogadallah, Gaber M
2016-04-01
Rice has shallow, weak roots, but it is unknown how much increase in yield potential could be achieved if the root/shoot ratio is corrected. Removing all tillers except the main one, in a japonica (Sakha 101) and an indica (IR64) rice cultivar, instantly increased the root/shoot ratio from 0.21 to 1.16 in Sakha 101 and from 0.16 to 1.46 in IR64. Over 30 days after detillering, the root/shoot ratios of the detillered plants decreased to 0.49 in Sakha 101 and 0.46 in IR64 but remained significantly higher than in the controls. The detillered plants showed two- or fourfold increase in the main tiller fresh weight, as a consequence of more positive midday leaf relative water content (RWC), and consistently higher rates of stomatal conductance and photosynthesis, but not transpiration, compared with the controls. The enhanced photosynthesis in Sakha 101 after detillering resulted from both improved water status and higher Rubisco contents whereas in IR64, increasing the Rubisco content did not contribute to improving photosynthesis. Detillering did not increase the carbohydrate contents of leaves but prevented starch depletion at the end of grain filling. The leaf protein content during vegetative and reproductive stages, the grain filling rate, the number of filled grains per panicle were greatly improved, bringing about 38.3 and 35.9% increase in the harvested grain dry weight per panicle in Sakha 101 and IR64, respectively. We provide evidence that improving the root performance by increasing the root/shoot ratio would eliminate the current limitations to photosynthesis and growth in rice. © 2015 Scandinavian Plant Physiology Society.
Monavarian, Morteza; Rashidi, Arman; Aragon, Andrew; Oh, Sang H; Nami, Mohsen; DenBaars, Steve P; Feezell, Daniel
2017-08-07
We report the carrier dynamics and recombination coefficients in single-quantum-well semipolar (202¯1¯) InGaN/GaN light-emitting diodes emitting at 440 nm with 93% peak internal quantum efficiency. The differential carrier lifetime is analyzed for various injection current densities from 5 A/cm 2 to 10 kA/cm 2 , and the corresponding carrier densities are obtained. The coupling of internal quantum efficiency and differential carrier lifetime vs injected carrier density (n) enables the separation of the radiative and nonradiative recombination lifetimes and the extraction of the Shockley-Read-Hall (SRH) nonradiative (A), radiative (B), and Auger (C) recombination coefficients and their n-dependency considering the saturation of the SRH recombination rate and phase-space filling. The results indicate a three to four-fold higher A and a nearly two-fold higher B0 for this semipolar orientation compared to that of c-plane reported using a similar approach [A. David and M. J. Grundmann, Appl. Phys. Lett. 96, 103504 (2010)]. In addition, the carrier density in semipolar (202¯1¯) is found to be lower than the carrier density in c-plane for a given current density, which is important for suppressing efficiency droop. The semipolar LED also shows a two-fold lower C0 compared to c-plane, which is consistent with the lower relative efficiency droop for the semipolar LED (57% vs. 69%). The lower carrier density, higher B 0 coefficient, and lower C 0 (Auger) coefficient are directly responsible for the high efficiency and low efficiency droop reported in semipolar (202¯1¯) LEDs.
NASA Astrophysics Data System (ADS)
Monavarian, Morteza; Rashidi, Arman; Aragon, Andrew; Oh, Sang H.; Nami, Mohsen; DenBaars, Steve P.; Feezell, Daniel
2017-08-01
We report the carrier dynamics and recombination coefficients in single-quantum-well semipolar $(20\\bar 2\\bar 1)$ InGaN/GaN light-emitting diodes emitting at 440 nm with 93% peak internal quantum efficiency. The differential carrier lifetime is analyzed for various injection current densities from 5 $A/cm^2$ to 10 $kA/cm^2$, and the corresponding carrier densities are obtained. The coupling of internal quantum efficiency and differential carrier lifetime vs injected carrier density ($n$) enables the separation of the radiative and nonradiative recombination lifetimes and the extraction of the Shockley-Read-Hall (SRH) nonradiative ($A$), radiative ($B$), and Auger ($C$) recombination coefficients and their $n$-dependency considering the saturation of the SRH recombination rate and phase-space filling. The results indicate a three to four-fold higher $A$ and a nearly two-fold higher $B_0$ for this semipolar orientation compared to that of $c$-plane reported using a similar approach [A. David and M. J. Grundmann, Appl. Phys. Lett. 96, 103504 (2010)]. In addition, the carrier density in semipolar $(20\\bar 2\\bar 1)$ is found to be lower than the carrier density in $c$-plane for a given current density, which is important for suppressing efficiency droop. The semipolar LED also shows a two-fold lower $C_0$ compared to $c$-plane, which is consistent with the lower relative efficiency droop for the semipolar LED (57% vs. 69%). The lower carrier density, higher $B_0$ coefficient, and lower $C_0$ (Auger) coefficient are directly responsible for the high efficiency and low efficiency droop reported in semipolar $(20\\bar 2\\bar 1)$ LEDs.
Donovan, Nancy J; Amariglio, Rebecca E; Zoller, Amy S; Rudel, Rebecca K; Gomez-Isla, Teresa; Blacker, Deborah; Hyman, Bradley T; Locascio, Joseph J; Johnson, Keith A; Sperling, Reisa A; Marshall, Gad A; Rentz, Dorene M
2014-12-01
To examine neuropsychiatric and neuropsychological predictors of progression from normal to early clinical stages of Alzheimer disease (AD). From a total sample of 559 older adults from the Massachusetts Alzheimer's Disease Research Center longitudinal cohort, 454 were included in the primary analysis: 283 with clinically normal cognition (CN), 115 with mild cognitive impairment (MCI), and 56 with subjective cognitive concerns (SCC) but no objective impairment, a proposed transitional group between CN and MCI. Two latent cognitive factors (memory-semantic, attention-executive) and two neuropsychiatric factors (affective, psychotic) were derived from the Alzheimer's Disease Centers' Uniform Data Set neuropsychological battery and Neuropsychiatric Inventory brief questionnaire. Factors were analyzed as predictors of time to progression to a worse diagnosis using a Cox proportional hazards regression model with backward elimination. Covariates included baseline diagnosis, gender, age, education, prior depression, antidepressant medication, symptom duration, and interaction terms. Higher/better memory-semantic factor score predicted lower hazard of progression (hazard ratio [HR] = 0.4 for 1 standard deviation [SD] increase, p <0.0001), and higher/worse affective factor score predicted higher hazard (HR = 1.3 for one SD increase, p = 0.01). No other predictors were significant in adjusted analyses. Using diagnosis as a sole predictor of transition to MCI, the SCC diagnosis carried a fourfold risk of progression compared with CN (HR = 4.1, p <0.0001). These results identify affective and memory-semantic factors as significant predictors of more rapid progression from normal to early stages of cognitive decline and highlight the subgroup of cognitively normal elderly with SCC as those with elevated risk of progression to MCI. Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.
Viazzi, Francesca; Ramesh, Ganesan; Jayakumar, Calpurnia; Leoncini, Giovanna; Garneri, Debora; Pontremoli, Roberto
2015-06-01
Semaphorins are guidance proteins implicated in several processes such as angiogenesis, organogenesis, cell migration, and cytokine release. Experimental studies showed that semaphorin-3a (SEMA3A) administration induces transient massive proteinuria, podocyte foot process effacement and endothelial cell damage in healthy animals. While SEMA3A signaling has been demonstrated to be mechanistically involved in experimental diabetic glomerulopathy and in acute kidney injury, to date its role in human chronic kidney disease (CKD) has not been investigated. To test the hypothesis that SEMA3A may play a role in human CKD, we performed a cross-sectional, nested, case-control study on 151 matched hypertensive patients with and without CKD. SEMA3A was quantified in the urine (USEMA) by ELISA. Glomerular filtration rate was estimated (eGFR) by the CKD-EPI formula and albuminuria was measured as albumin-to-creatinine ratio (ACR). USEMA levels were positively correlated with urine ACR (p = 0.001) and serum creatinine (p < 0.001). USEMA was higher in patients with both components of renal damage as compared to those with only one and those with normal renal function (p < 0.007 and <0.001, respectively). The presence of increased USEMA levels (i.e. top quartile) entailed a fourfold higher risk of combined renal damage (p < 0.001) and an almost twofold higher risk of macroalbuminuria (p = 0.005) or of reduced eGFR, even adjusting for confounding factors (p = 0.002). USEMA is independently associated with CKD in both diabetic and non diabetic hypertensive patients. Further studies may help clarify the mechanisms underlying this association and possibly the pathogenic changes leading to the development of CKD.
Guggi, Davide; Marschütz, Michaela K; Bernkop-Schnürch, Andreas
2004-04-15
This study examined the influence of the pH on the mucoadhesive and cohesive properties of polyarcylic acid (PAA) and thiolated PAA. The pH of PAA (molecular mass: 450 kDa) and of a corresponding PAA-cysteine conjugate was adjusted to 3, 4, 5, 6, 7 and 8. The amount of immobilised thiol groups and disulfide bonds was determined via Ellman's reagent. Tablets were compressed out of each pH-batch of both thiolated and unmodified PAA and the swelling behaviour, the disintegration time and the mucoadhesiveness were evaluated. The amount of thiol/disulfide groups per gram thiolated PAA of pH 3 and pH 8 was determined to be 332 +/- 94 micromol and 162 +/- 46 micromol, respectively. The thiolated PAA tablets displayed a minimum four-fold higher water uptake compared to unmodified PAA tablets. A faster and higher water uptake of both polymer types was observed above pH 5. Thiolated polymer tablets showed a 3-20-fold more prolonged disintegration time than unmodified PAA tablets. The cohesiveness of PAA-cysteine conjugate increased at higher pH, whereas the unmodified PAA behaved inversely. A 3-7-fold stronger mucoadhesiveness was observed for the PAA-cysteine conjugate tablets compared to unmodified PAA tablets. For both thiolated and unmodified polymer the mucoadhesiveness was 2-4-fold enhanced below pH 5. The difference in mucoadhesion between the two polymer types was most pronounced at these lower pH values. In this study substantial information regarding the pH-dependence of mucoadhesion and cohesion of unmodified polyacrylates and of thiolated polyacrylates is provided, representing helpful basic information for an ameliorated deployment of these polymers.
A higher-order split-step Fourier parabolic-equation sound propagation solution scheme.
Lin, Ying-Tsong; Duda, Timothy F
2012-08-01
A three-dimensional Cartesian parabolic-equation model with a higher-order approximation to the square-root Helmholtz operator is presented for simulating underwater sound propagation in ocean waveguides. The higher-order approximation includes cross terms with the free-space square-root Helmholtz operator and the medium phase speed anomaly. It can be implemented with a split-step Fourier algorithm to solve for sound pressure in the model. Two idealized ocean waveguide examples are presented to demonstrate the performance of this numerical technique.
Hollingworth, Stephen
2012-01-01
In skeletal muscle fibers, action potentials elicit contractions by releasing calcium ions (Ca2+) from the sarcoplasmic reticulum. Experiments on individual mouse muscle fibers micro-injected with a rapidly responding fluorescent Ca2+ indicator dye reveal that the amount of Ca2+ released is three- to fourfold larger in fast-twitch fibers than in slow-twitch fibers, and the proportion of the released Ca2+ that binds to troponin to activate contraction is substantially smaller. PMID:22450485
Wahl, Markus; Stöhr, Meike; Spillmann, Hannes; Jung, Thomas A; Gade, Lutz H
2007-04-07
Fourfold symmetric zinc-octaethylporphyrin (OEP) has been incorporated in the holes of the hexagonal molecular network generated by thermal dehydrogenation of 4,9-diaminoperylene-quinone-3,10-diimine (DPDI) on a Cu(111) surface and displayed hindered rotation; the reorganization between the potential minima, a rotation-libration, which is characterized by an activation energy of ED=0.17+/-0.03 eV, has been monitored in the STM tunnelling currents as a bi-state "switching".
de Oteyza, D G; El-Sayed, A; Garcia-Lastra, J M; Goiri, E; Krauss, T N; Turak, A; Barrena, E; Dosch, H; Zegenhagen, J; Rubio, A; Wakayama, Y; Ortega, J E
2010-12-07
Metal-organic interfaces based on copper-phthalocyanine monolayers are studied in dependence of the metal substrate (Au versus Cu), of its symmetry [hexagonal (111) surfaces versus fourfold (100) surfaces], as well as of the donor or acceptor semiconducting character associated with the nonfluorinated or perfluorinated molecules, respectively. Comparison of the properties of these systematically varied metal-organic interfaces provides new insight into the effect of each of the previously mentioned parameters on the molecule-substrate interactions.
Bonding as a Positive Youth Development Construct: A Conceptual Review
Lee, Tak Yan; Lok, David P. P.
2012-01-01
The concept of bonding as a positive youth development construct is reviewed in this paper. The goals are fourfold. First, theoretical perspectives of bonding are delineated. Secondly, the relationships among bonding to caregivers, friends, romantic partners, as well as teachers, and adolescents' positive developmental outcomes are reviewed. Thirdly, with theoretical and empirical support, a discussion on how to promote bonding among adolescents is offered. Finally, a critical review on the cultural issues of bonding is provided. PMID:22623898
NASA Astrophysics Data System (ADS)
Bause, Markus
2008-02-01
In this work we study mixed finite element approximations of Richards' equation for simulating variably saturated subsurface flow and simultaneous reactive solute transport. Whereas higher order schemes have proved their ability to approximate reliably reactive solute transport (cf., e.g. [Bause M, Knabner P. Numerical simulation of contaminant biodegradation by higher order methods and adaptive time stepping. Comput Visual Sci 7;2004:61-78]), the Raviart- Thomas mixed finite element method ( RT0) with a first order accurate flux approximation is popular for computing the underlying water flow field (cf. [Bause M, Knabner P. Computation of variably saturated subsurface flow by adaptive mixed hybrid finite element methods. Adv Water Resour 27;2004:565-581, Farthing MW, Kees CE, Miller CT. Mixed finite element methods and higher order temporal approximations for variably saturated groundwater flow. Adv Water Resour 26;2003:373-394, Starke G. Least-squares mixed finite element solution of variably saturated subsurface flow problems. SIAM J Sci Comput 21;2000:1869-1885, Younes A, Mosé R, Ackerer P, Chavent G. A new formulation of the mixed finite element method for solving elliptic and parabolic PDE with triangular elements. J Comp Phys 149;1999:148-167, Woodward CS, Dawson CN. Analysis of expanded mixed finite element methods for a nonlinear parabolic equation modeling flow into variably saturated porous media. SIAM J Numer Anal 37;2000:701-724]). This combination might be non-optimal. Higher order techniques could increase the accuracy of the flow field calculation and thereby improve the prediction of the solute transport. Here, we analyse the application of the Brezzi- Douglas- Marini element ( BDM1) with a second order accurate flux approximation to elliptic, parabolic and degenerate problems whose solutions lack the regularity that is assumed in optimal order error analyses. For the flow field calculation a superiority of the BDM1 approach to the RT0 one is observed, which however is less significant for the accompanying solute transport.
Health Care Utilization and the Cost of Post-Traumatic ARDS Care.
Robles, Anamaria J; Kornblith, Lucy Z; Hendrickson, Carolyn M; Howard, Benjamin M; Conroy, Amanda S; Moazed, Farzad; Calfee, Carolyn S; Cohen, Mitchell J; Callcut, Rachael A
2018-04-02
Post-traumatic acute respiratory distress syndrome (ARDS) is associated with prolonged mechanical ventilation and longer hospitalizations. The relationship between post-traumatic ARDS severity and financial burden has not been previously studied. We hypothesized that increasing severity is associated with incrementally higher health care costs. Adults arriving as the highest level of trauma activation were enrolled in an ongoing prospective cohort study. Patients who survived ≥6 hours are included in the analysis. Blinded review of chest radiographs was performed by two independent physicians for any intubated patient with PaO2:FiO2 ratio (P/F) ≤300mgHg during the first 8 days of admission. The severity of ARDS was classified by the Berlin criteria. Hospital charge data was utilized to perform standard costing analysis. ARDS occurred in 13% (203/1586). The distribution of disease severity was 33% mild, 42% moderate, and 25% severe. Patients with ARDS were older (41 vs 35 years, p<0.01), had higher median ISS (30 vs 10, p<0.01), more chest injury (AIS≥3: 51% vs 21%, p<0.01), and blunt mechanisms (85% vs 53%, p<0.01). By ARDS severity, there was no significant difference in age, mechanism, or rate of traumatic brain injury. Increasing ARDS severity was associated with higher ISS and higher mortality rates. Standardized total hospital charges were four-fold higher for patients who developed ARDS compared to those who did not develop ARDS ($434K vs $96K, p<0.01). Furthermore, the daily hospital charges significantly increased across categories of worsening ARDS severity (mild $20,451; moderate $23,994; severe $33,316, p<0.01). The development of post-traumatic ARDS is associated with higher health care costs. Among trauma patients who develop ARDS, total hospital charges per day increase with worsening severity of disease. Prevention, early recognition, and treatment of ARDS after trauma are potentially important objectives for efforts to control health care costs in this population. IV STUDY TYPE: Economic and Value-based Evaluations.
Mass Care (ESF-6) Preparedness for Catastrophic Disasters
2009-09-01
seismic event along the New Madrid fault zone resulting in an earthquake with a Richter scale reading approximating 7.7 or higher to determine the...shelter, mass feeding, bulk distribution, catastrophic disaster response, New Madrid earthquake, long-term recovery process, National Shelter...catastrophic seismic event along the New Madrid fault zone resulting in an earthquake with a Richter scale reading approximating 7.7 or higher to
Strathdee, Steffanie A.; Lozada, Remedios; Ojeda, Victoria D.; Pollini, Robin A.; Brouwer, Kimberly C.; Vera, Alicia; Cornelius, Wayne; Nguyen, Lucie; Magis-Rodriguez, Carlos; Patterson, Thomas L.
2008-01-01
HIV prevalence is rising, especially among high risk females in Tijuana, Baja California, a Mexico-US border city situated on major migration and drug trafficking routes. We compared factors associated with HIV infection among male and female injection drug users (IDUs) in Tijuana in an effort to inform HIV prevention and treatment programs. IDUs aged ≥18 years were recruited using respondent-driven sampling and underwent testing for HIV, syphilis and structured interviews. Logistic regression identified correlates of HIV infection, stratified by gender. Among 1056 IDUs, most were Mexican-born but 67% were born outside Tijuana. Reasons for moving to Tijuana included deportation from the US (56% for males, 29% for females), and looking for work/better life (34% for females, 15% for males). HIV prevalence was higher in females versus males (10.2% vs. 3.5%, p = 0.001). Among females (N = 158), factors independently associated with higher HIV prevalence included younger age, lifetime syphilis infection and living in Tijuana for longer durations. Among males (N = 898), factors independently associated with higher HIV prevalence were syphilis titers consistent with active infection, being arrested for having ‘track-marks’, having larger numbers of recent injection partners and living in Tijuana for shorter durations. An interaction between gender and number of years lived in Tijuana regressed on HIV infection was significant (p = 0.03). Upon further analysis, deportation from the U.S. explained the association between shorter duration lived in Tijuana and HIV infection among males; odds of HIV infection were four-fold higher among male injectors deported from the US, compared to other males, adjusting for all other significant correlates (p = 0.002). Geographic mobility has a profound influence on Tijuana's evolving HIV epidemic, and its impact is significantly modified by gender. Future studies are needed to elucidate the context of mobility and HIV acquisition in this region, and whether US immigration policies adversely affect HIV risk. PMID:18665250
Smirnakou, Sonia; Ouzounis, Theoharis; Radoglou, Kalliopi M.
2017-01-01
Regulation of the growth, development, and quality of plants by the control of light quality has attracted extensive attention worldwide. The aim of this study was to examine the effects of continuous LED spectrum for indoor plant pre-cultivation and to investigate the morphological and physiological responses of a common broadleaved tree species in Mediterranean environment, Quercus ithaburensis var. macrolepis at seedling developmental stage. Thus, the seedlings were pre-cultivated for 28 days, under five different LED light qualities: (1) Fluorescent (FL) as control light (2) L20AP67 (high in green and moderate in far-red), (3) AP673L (high in green and red), (4) G2 (highest in red and far-red), AP67 (high in blue, red, and far-red), and (5) NS1 (highest in blue and green and lowest in far-red) LEDs. Further examination was held at the nursery for 1 year, on several seedling quality traits. Indeed, AP67 and AP673L triggered higher leaf formation, while L20AP67 positively affected seedling shoot development. NS1 and AP67 LED pre-cultivated seedlings showed significantly higher root fibrosity than those of FL light. Furthermore, NS1 and AP673L LEDs induced fourfold increase on seedling root dry weight than FL light. Hence, evaluating the seedling nursery performance attributes, most of those photomorphogenetic responses previously obtained were still detectable. Even more so, LED pre-cultivated seedlings showed higher survival and faster growth indicating better adaptation even under natural light conditions, a fact further reinforced by the significantly higher Dickson’s quality index acquired. In conclusion, the goal of each nursery management program is the production of high quality seedlings with those desirable traits, which in turn satisfy the specific needs for a particular reforestation site. Thus, the enhanced oak seedling quality traits formed under continuous LEDs spectrum especially of NS1 and AP673L pre-cultivation may potentially fulfill this goal. PMID:28261244
Strathdee, Steffanie A; Lozada, Remedios; Ojeda, Victoria D; Pollini, Robin A; Brouwer, Kimberly C; Vera, Alicia; Cornelius, Wayne; Nguyen, Lucie; Magis-Rodriguez, Carlos; Patterson, Thomas L
2008-07-30
HIV prevalence is rising, especially among high risk females in Tijuana, Baja California, a Mexico-US border city situated on major migration and drug trafficking routes. We compared factors associated with HIV infection among male and female injection drug users (IDUs) in Tijuana in an effort to inform HIV prevention and treatment programs. IDUs aged > or = 18 years were recruited using respondent-driven sampling and underwent testing for HIV, syphilis and structured interviews. Logistic regression identified correlates of HIV infection, stratified by gender. Among 1056 IDUs, most were Mexican-born but 67% were born outside Tijuana. Reasons for moving to Tijuana included deportation from the US (56% for males, 29% for females), and looking for work/better life (34% for females, 15% for males). HIV prevalence was higher in females versus males (10.2% vs. 3.5%, p = 0.001). Among females (N = 158), factors independently associated with higher HIV prevalence included younger age, lifetime syphilis infection and living in Tijuana for longer durations. Among males (N = 898), factors independently associated with higher HIV prevalence were syphilis titers consistent with active infection, being arrested for having 'track-marks', having larger numbers of recent injection partners and living in Tijuana for shorter durations. An interaction between gender and number of years lived in Tijuana regressed on HIV infection was significant (p = 0.03). Upon further analysis, deportation from the U.S. explained the association between shorter duration lived in Tijuana and HIV infection among males; odds of HIV infection were four-fold higher among male injectors deported from the US, compared to other males, adjusting for all other significant correlates (p = 0.002). Geographic mobility has a profound influence on Tijuana's evolving HIV epidemic, and its impact is significantly modified by gender. Future studies are needed to elucidate the context of mobility and HIV acquisition in this region, and whether US immigration policies adversely affect HIV risk.
Truong-Bolduc, Que Chi; Hooper, David C.
2007-01-01
MgrA is a known regulator of the expression of several multidrug transporters in Staphylococcus aureus. We identified another regulator of multiple efflux pumps, NorG, by its ability, like that of MgrA, to bind specifically to the promoter of the gene encoding the NorA efflux pump. NorG is a member of the family of the GntR-like transcriptional regulators, and it binds specifically to the putative promoters of the genes encoding multidrug efflux pumps NorA, NorB, NorC, and AbcA. Overexpression of norG produces a threefold increase in norB transcripts associated with a fourfold increase in the level of resistance to quinolones. In contrast, disruption of norG produces no change in the level of transcripts of norA, norB, and norC but causes an increase of at least threefold in the transcript level of abcA, associated with a fourfold increase in resistance to methicillin, cefotaxime, penicillin G, and nafcillin. Overexpression of cloned abcA caused an 8- to 128-fold increase in the level of resistance to all four β-lactam antibiotics. Furthermore, MgrA and NorG have opposite effects on norB and abcA expression. MgrA acts as an indirect repressor for norB and a direct activator for abcA, whereas NorG acts as a direct activator for norB and a direct repressor for abcA. PMID:17277059
NASA Astrophysics Data System (ADS)
Yasuzuka, Syuma; Koga, Hiroaki; Yamamura, Yasuhisa; Saito, Kazuya; Uji, Shinya; Terashima, Taichi; Akutsu, Hiroki; Yamada, Jun-ichi
2017-08-01
Resistance measurements have been performed to investigate the dimensionality and the in-plane anisotropy of the upper critical field (Hc2) for β-(BDA-TTP)2SbF6 in fields H up to 15 T and at temperatures T from 1.5 to 7.5 K, where BDA-TTP stands for 2,5-bis(1,3-dithian-2-ylidene)-1,3,4,6-tetrathiapentalene. The upper critical fields parallel and perpendicular to the conduction layer are determined and dimensional crossover from anisotropic three-dimensional behavior to two-dimensional behavior is found at around 6 K. When the direction of H is varied within the conducting layer at 6.0 K, Hc2 shows twofold symmetry: Hc2 along the minimum Fermi wave vector (maximum Fermi velocity) is larger than that along the maximum Fermi wave vector (minimum Fermi velocity). The normal-state magnetoresistance has twofold symmetry similar to Hc2 and shows a maximum when the magnetic field is nearly parallel to the maximum Fermi wave vector. This tendency is consistent with the Fermi surface anisotropy. At 3.5 K, we found clear fourfold symmetry of Hc2 despite the fact that the normal-state magnetoresistance shows twofold symmetry arising from the Fermi surface anisotropy. The origin of the fourfold symmetry of Hc2 is discussed in terms of the superconducting gap structure in β-(BDA-TTP)2SbF6.
NASA Technical Reports Server (NTRS)
Clement, Warren F.; Gorder, Peter J.; Jewell, Wayne F.
1991-01-01
Developing a single-pilot, all-weather nap-of-the-earth (NOE) capability requires fully automatic NOE (ANOE) navigation and flight control. Innovative guidance and control concepts are investigated in a four-fold research effort that: (1) organizes the on-board computer-based storage and real-time updating of NOE terrain profiles and obstacles in course-oriented coordinates indexed to the mission flight plan; (2) defines a class of automatic anticipative pursuit guidance algorithms and necessary data preview requirements to follow the vertical, lateral, and longitudinal guidance commands dictated by the updated flight profiles; (3) automates a decision-making process for unexpected obstacle avoidance; and (4) provides several rapid response maneuvers. Acquired knowledge from the sensed environment is correlated with the forehand knowledge of the recorded environment (terrain, cultural features, threats, and targets), which is then used to determine an appropriate evasive maneuver if a nonconformity of the sensed and recorded environments is observed. This four-fold research effort was evaluated in both fixed-based and moving-based real-time piloted simulations, thereby, providing a practical demonstration for evaluating pilot acceptance of the automated concepts, supervisory override, manual operation, and re-engagement of the automatic system. Volume one describes the major components of the guidance and control laws as well as the results of the piloted simulations. Volume two describes the complete mathematical model of the fully automatic guidance system for rotorcraft NOE flight following planned flight profiles.
NASA Technical Reports Server (NTRS)
Clement, Warren F.; Gorder, Peter J.; Jewell, Wayne F.
1991-01-01
Developing a single-pilot, all-weather nap-of-the-earth (NOE) capability requires fully automatic NOE (ANOE) navigation and flight control. Innovative guidance and control concepts are investigated in a four-fold research effort that: (1) organizes the on-board computer-based storage and real-time updating of NOE terrain profiles and obstacles in course-oriented coordinates indexed to the mission flight plan; (2) defines a class of automatic anticipative pursuit guidance algorithms and necessary data preview requirements to follow the vertical, lateral, and longitudinal guidance commands dictated by the updated flight profiles; (3) automates a decision-making process for unexpected obstacle avoidance; and (4) provides several rapid response maneuvers. Acquired knowledge from the sensed environment is correlated with the forehand knowledge of the recorded environment (terrain, cultural features, threats, and targets), which is then used to determine an appropriate evasive maneuver if a nonconformity of the sensed and recorded environments is observed. This four-fold research effort was evaluated in both fixed-base and moving-base real-time piloted simulations; thereby, providing a practical demonstration for evaluating pilot acceptance of the automated concepts, supervisory override, manual operation, and re-engagement of the automatic system. Volume one describes the major components of the guidance and control laws as well as the results of the piloted simulations. Volume two describes the complete mathematical model of the fully automatic guidance system for rotorcraft NOE flight following planned flight profiles.
Elevation of oleate-activated phospholipase D activity during thymic atrophy
Lee, Youngkyun; Song, Soo-Mee; Park, Heung Soon; Kim, Sungyeol; Koh, Eun-Hee; Choi, Myung Sun; Choi, Myung-Un
2002-01-01
Various phospholipases are thought to be associated with the in vitro apoptosis of thymocytes. In the present study, the in vivo phospholipase D (PLD) activity of rat thymus was studied after whole-body X-irradiation or injection of dexamethasone (DEX). Using exogenous [14C]dipalmitoyl phosphatidylcholine (PC) as the substrate, an elevation of oleate-activated PLD activity was observed during thymic atrophy. The activity increases were sevenfold at 48 hr after 5-Gy irradiation and fourfold at 72 hr after injection of 5 mg/kg DEX. The elevation of PLD activity appeared to parallel extensive thymus shrinkage. An increased level of thymic phosphatidic acid (PA), the presumed physiological product of PLD action on PC, was also detected. By comparing the acyl chains of PA with those of other phospholipids, PA appeared to originate from PC. To assess the role of PLD during thymic atrophy, thymocytes and stromal cells were isolated. Although thymocytes themselves exhibited significant PLD activation, the major elevation in PLD activity (greater than fourfold) was found in isolated stromal cells. PLD was also activated during in vitro phagocytosis of apoptotic thymocytes by the macrophage-like cell line P388D1. This in vitro phagocytosis was significantly inhibited by PLD action blockers, such as 2,3-diphosphoglycerate and 1-butanol. These observations strongly suggest that the alteration of oleate-activated PLD activity is part of an in vivo event in the progression of thymic atrophy, including phagocytic clearance of apoptotic thymocytes. PMID:12460188
Mechanisms for fatigue and wear of polysilicon structural thinfilms
DOE Office of Scientific and Technical Information (OSTI.GOV)
Alsem, Daniel Henricus
2006-01-01
Fatigue and wear in micron-scale polysilicon structural films can severely impact the reliability of microelectromechanical systems (MEMS). Despite studies on fatigue and wear behavior of these films, there is still an on-going debate regarding the precise physical mechanisms for these two important failure modes. Although macro-scale silicon does not fatigue, this phenomenon is observed in micron-scale silicon. It is shown that for polysilicon devices fabricated in the MUMPs foundry and SUMMiT process stress-lifetime data exhibits similar trends in ambient air, shorter lifetimes in higher relative humidity environments and no fatigue failure at all in high vacuum. Transmission electron microscopy ofmore » the surface oxides of the samples show an approximate four-fold thickening of the oxide at stress concentrations after fatigue failure, but no thickening after fracture in air or after fatigue cycling in vacuo. It is found that such oxide thickening and fatigue failure (in air) occurs in devices with initial oxide thicknesses of ~4-20 nm. Such results are interpreted and explained by a reaction layer fatigue mechanism; specifically, moisture-assisted subcritical cracking within a cyclic stress-assisted thickened oxide layer occurs until the crack reaches a critical size to cause catastrophic failure. Polysilicon specimens from the SUMMiT process are used to study wear mechanisms in micron-scale silicon in ambient air. Worn parts are examined by analytical scanning and transmission electron microscopy, while temperature changes are monitored using infrared microscopy. These results are compared with the development of values of static coefficients of friction (COF) with number of wear cycles. Observations show amorphous debris particles (~50-100 nm) created by fracture through the silicon grains (~500 nm), which subsequently oxidize, agglomerate into clusters and create plowing tracks. A nano-crystalline layer (~20-200 nm) forms at worn regions. No dislocations or extreme temperature increases are found, ruling out plasticity and temperature-assisted mechanisms. The COF reaches a steady-state value of ~0.20±0.05 after a short time at an initial value of ~0.11±0.01. Plowing tracks are found before the steady-state value of the COF is reached, suggesting only a short adhesive wear regime. This suggests a predominantly abrasive wear mechanism, controlled by fracture, which commences by the first particles created by adhesive wear.« less
Mechanisms for fatigue and wear of polysilicon structural thin films
NASA Astrophysics Data System (ADS)
Alsem, Daniel Henricus
Fatigue and wear in micron-scale polysilicon structural films can severely impact the reliability of microelectromechanical systems (MEMS). Despite studies on fatigue and wear behavior of these films, there is still an on-going debate regarding the precise physical mechanisms for these two important failure modes. Although macro-scale silicon does not fatigue, this phenomenon is observed in micron-scale silicon. It is shown that for polysilicon devices fabricated in the MUMPs foundry and SUMMiT(TM) process stress-lifetime data exhibits similar trends in ambient air, shorter lifetimes in higher relative humidity environments and no fatigue failure at all in high vacuum. Transmission electron microscopy of the surface oxides of the samples show an approximate four-fold thickening of the oxide at stress concentrations after fatigue failure, but no thickening after fracture in air or after fatigue cycling in vacuo . It is found that such oxide thickening and fatigue failure (in air) occurs in devices with initial oxide thicknesses of ˜4-20 nm. Such results are interpreted and explained by a reaction-layer fatigue mechanism; specifically, moisture-assisted subcritical cracking within a cyclic stress-assisted thickened oxide layer occurs until the crack reaches a critical size to cause catastrophic failure. Polysilicon specimens from the SUMMiT(TM) process are used to study wear mechanisms in micron-scale silicon in ambient air. Worn parts are examined by analytical scanning and transmission electron microscopy, while temperature changes are monitored using infrared microscopy. These results are compared with the development of values of static coefficients of friction (COF) with number of wear cycles. Observations show amorphous debris particles (˜50-100 nm) created by fracture through the silicon grains (˜500 nm), which subsequently oxidize, agglomerate into clusters and create plowing tracks. A nano-crystalline layer (˜20-200 nm) forms at worn regions. No dislocations or extreme temperature increases are found, ruling out plasticity and temperature-assisted mechanisms. The COF reaches a steady-state value of ˜0.20+/-0.05 after a short time at an initial value of ˜0.11+/-0.01. Plowing tracks are found before the steady-state value of the COF is reached, suggesting only a short adhesive wear regime. This suggests a predominantly abrasive wear mechanism, controlled by fracture, which commences by the first particles created by adhesive wear.
Seol, Sang-Hoon; Davidson, Brian P; Belcik, J Todd; Mott, Brian H; Goodman, Reid M; Ammi, Azzdine; Lindner, Jonathan R
2015-06-01
There is growing interest in limb contrast-enhanced ultrasound (CEU) perfusion imaging for the evaluation of peripheral artery disease. Because of low resting microvascular blood flow in skeletal muscle, signal enhancement during limb CEU is prohibitively low for real-time imaging. The aim of this study was to test the hypothesis that this obstacle can be overcome by intermediate- rather than low-power CEU when performed with an acoustically resilient microbubble agent. Viscoelastic properties of Definity and Sonazoid were assessed by measuring bulk modulus during incremental increases in ambient pressure to 200 mm Hg. Comparison of in vivo microbubble destruction and signal enhancement at a mechanical index (MI) of 0.1 to 0.4 was performed by sequential reduction in pulsing interval from 10 to 0.05 sec during limb CEU at 7 MHz in mice and 1.8 MHz in dogs. Destruction was also assessed by broadband signal generation during passive cavitation detection. Real-time CEU perfusion imaging with destruction-replenishment was then performed at 1.8 MHz in dogs using an MI of 0.1, 0.2, or 0.3. Sonazoid had a higher bulk modulus than Definity (66 ± 12 vs 29 ± 2 kPa, P = .02) and exhibited less inertial cavitation (destruction) at MIs ≥ 0.2. On in vivo CEU, maximal signal intensity increased incrementally with MI for both agents and was equivalent between agents except at an MI of 0.1 (60% and 85% lower for Sonazoid at 7 and 1.8 MHz, respectively, P < .05). However, on progressive shortening of the pulsing interval, Definity was nearly completely destroyed at MIs ≥ 0.2 at 1.8 and 7 MHz, whereas Sonazoid was destroyed only at 1.8 MHz at MIs ≥ 0.3. As a result, real-time CEU perfusion imaging demonstrated approximately fourfold greater enhancement for Sonazoid at an MI of 0.3 to 0.4. Robust signal enhancement during real-time CEU perfusion imaging of the limb is possible when using intermediate-power imaging coupled with a durable microbubble contrast agent. Copyright © 2015 American Society of Echocardiography. All rights reserved.
Testing higher-order Lagrangian perturbation theory against numerical simulation. 1: Pancake models
NASA Technical Reports Server (NTRS)
Buchert, T.; Melott, A. L.; Weiss, A. G.
1993-01-01
We present results showing an improvement of the accuracy of perturbation theory as applied to cosmological structure formation for a useful range of quasi-linear scales. The Lagrangian theory of gravitational instability of an Einstein-de Sitter dust cosmogony investigated and solved up to the third order is compared with numerical simulations. In this paper we study the dynamics of pancake models as a first step. In previous work the accuracy of several analytical approximations for the modeling of large-scale structure in the mildly non-linear regime was analyzed in the same way, allowing for direct comparison of the accuracy of various approximations. In particular, the Zel'dovich approximation (hereafter ZA) as a subclass of the first-order Lagrangian perturbation solutions was found to provide an excellent approximation to the density field in the mildly non-linear regime (i.e. up to a linear r.m.s. density contrast of sigma is approximately 2). The performance of ZA in hierarchical clustering models can be greatly improved by truncating the initial power spectrum (smoothing the initial data). We here explore whether this approximation can be further improved with higher-order corrections in the displacement mapping from homogeneity. We study a single pancake model (truncated power-spectrum with power-spectrum with power-index n = -1) using cross-correlation statistics employed in previous work. We found that for all statistical methods used the higher-order corrections improve the results obtained for the first-order solution up to the stage when sigma (linear theory) is approximately 1. While this improvement can be seen for all spatial scales, later stages retain this feature only above a certain scale which is increasing with time. However, third-order is not much improvement over second-order at any stage. The total breakdown of the perturbation approach is observed at the stage, where sigma (linear theory) is approximately 2, which corresponds to the onset of hierarchical clustering. This success is found at a considerable higher non-linearity than is usual for perturbation theory. Whether a truncation of the initial power-spectrum in hierarchical models retains this improvement will be analyzed in a forthcoming work.
Seitz, Frank; Lüderwald, Simon; Rosenfeldt, Ricki R.; Schulz, Ralf; Bundschuh, Mirco
2015-01-01
During their aquatic life cycle, nanoparticles are subject to environmentally driven surface modifications (e.g. agglomeration or coating) associated with aging. Although the ecotoxicological potential of nanoparticles might be affected by these processes, only limited information about the potential impact of aging is available. In this context, the present study investigated acute (96 h) and chronic (21 d) implications of systematically aged titanium dioxide nanoparticles (nTiO2; ~90 nm) on the standard test species Daphnia magna by following the respective test guidelines. The nTiO2 were aged for 0, 1, 3 and 6 d in media with varying ionic strengths (Milli-Q water: approx. 0.00 mmol/L and ASTM: 9.25 mmol/L) in the presence or absence of natural organic matter (NOM). Irrespective of the other parameters, aging in Milli-Q did not change the acute toxicity relative to an unaged control. In contrast, 6 d aged nTiO2 in ASTM without NOM caused a fourfold decreased acute toxicity. Relative to the 0 d aged particles, nTiO2 aged for 1 and 3 d in ASTM with NOM, which is the most environmentally-relevant setup used here, significantly increased acute toxicity (by approximately 30%), while a toxicity reduction (60%) was observed for 6 d aged nTiO2. Comparable patterns were observed during the chronic experiments. A likely explanation for this phenomenon is that the aging of nTiO2 increases the particle size at the start of the experiment or the time of the water exchange from <100 nm to approximately 500 nm, which is the optimal size range to be taken up by filter feeding D. magna. If subjected to further agglomeration, larger nTiO2 particles, however, cannot be retained by the daphnids’ filter apparatus ultimately reducing their ecotoxicological potential. This non-linear pattern of increasing and decreasing nTiO2 related toxicity over the aging duration, highlights the knowledge gap regarding the underlying mechanisms and processes. This understanding seems, however, fundamental to predict the risks of nanoparticles in the field. PMID:25933435
Anderson, Joel G.; Fordahl, Steve C.; Cooney, Paula T.; Weaver, Tara L.; Colyer, Christa L.; Erikson, Keith M.
2011-01-01
Unlike other essential trace elements (e.g., zinc and iron) it is the toxicity of manganese (Mn) that is more common in human populations than its deficiency. Data suggest alterations in dopamine biology may drive the effects associated with Mn neurotoxicity, though recently γ-aminobutyric acid (GABA) has been implicated. In addition, iron deficiency (ID), a common nutritional problem, may cause disturbances in neurochemistry by facilitating accumulation of Mn in the brain. Previous data from our lab have shown decreased brain tissue levels of GABA as well as decreased 3H-GABA uptake in synaptosomes as a result of Mn exposure and ID. These results indicate a possible increase in the concentration of extracellular GABA due to alterations in expression of GABA transport and receptor proteins. In this study weanling-male Sprague-Dawley rats were randomly placed into one of four dietary treatment groups: control (CN; 35 mg Fe/kg diet), iron-deficient (ID; 6 mg Fe/kg diet), CN with Mn supplementation (via the drinking water; 1 g Mn/L) (CNMn), and ID with Mn supplementation (IDMn). Using in vivo microdialysis, an increase in extracellular GABA concentrations in the striatum was observed in response to Mn exposure and ID although correlational analysis reveals that extracellular GABA is related more to extracellular iron levels and not Mn. A diverse effect of Mn exposure and ID was observed in the regions examined via Western blot and RT-PCR analysis, with effects on mRNA and protein expression of GAT-1, GABAA, and GABAB differing between and within the regions examined. For example, Mn exposure reduced GAT-1 protein expression by approximately 50% in the substantia nigra, while increasing mRNA expression approximately four-fold, while in the caudate putamen mRNA expression was decreased with no effect on protein expression. These data suggest that Mn exposure results in an increase in extracellular GABA concentrations via altered expression of transport and receptor proteins, which may be the basis of the neurological characteristics of manganism. PMID:18771689
Effects of luminal flow and nucleotides on [Ca(2+)](i) in rabbit cortical collecting duct.
Woda, Craig B; Leite, Maurilo; Rohatgi, Rajeev; Satlin, Lisa M
2002-09-01
Nucleotide binding to purinergic P2 receptors contributes to the regulation of a variety of physiological functions in renal epithelial cells. Whereas P2 receptors have been functionally identified at the basolateral membrane of the cortical collecting duct (CCD), a final regulatory site of urinary Na(+), K(+), and acid-base excretion, controversy exists as to whether apical purinoceptors exist in this segment. Nor has the distribution of receptor subtypes present on the unique cell populations that constitute Ca(2+) the CCD been established. To examine this, we measured nucleotide-induced changes in intracellular Ca(2+) concentration ([Ca(2+)](i)) in fura 2-loaded rabbit CCDs microperfused in vitro. Resting [Ca(2+)](i) did not differ between principal and intercalated cells, averaging approximately 120 nM. An acute increase in tubular fluid flow rate, associated with a 20% increase in tubular diameter, led to increases in [Ca(2+)](i) in both cell types. Luminal perfusion of 100 microM UTP or ATP-gamma-S, in the absence of change in flow rate, caused a rapid and transient approximately fourfold increase in [Ca(2+)](i) in both cell types (P < 0.05). Luminal suramin, a nonspecific P2 receptor antagonist, blocked the nucleotide- but not flow-induced [Ca(2+)](i) transients. Luminal perfusion with a P2X (alpha,beta-methylene-ATP), P2X(7) (benzoyl-benzoyl-ATP), P2Y(1) (2-methylthio-ATP), or P2Y(4)/P2Y(6) (UDP) receptor agonist had no effect on [Ca(2+)](i). The nucleotide-induced [Ca(2+)](i) transients were inhibited by the inositol-1,4,5-triphosphate receptor blocker 2-aminoethoxydiphenyl borate, thapsigargin, which depletes internal Ca(2+) stores, luminal perfusion with a Ca(2+)-free perfusate, or the L-type Ca(2+) channel blocker nifedipine. These results suggest that luminal nucleotides activate apical P2Y(2) receptors in the CCD via pathways that require both internal Ca(2+) mobilization and extracellular Ca(2+) entry. The flow-induced rise in [Ca(2+)](i) is apparently not mediated by apical P2 purinergic receptor signaling.
Wetmore, James B; Liu, Jiannong; Li, Suying; Hu, Yan; Peng, Yi; Gilbertson, David T; Collins, Allan J
2017-01-06
The Healthy People 2020 initiative established goals for patients with CKD and ESRD. We assessed United States progress toward some of these key goals. Using data from the Centers for Medicare and Medicaid Services ESRD database, we created yearly cohorts of patients on incident and prevalent dialysis from 2000 to 2013. Change in event rate or proportion change over the study years was modeled using Poisson regression with adjustment for age, race, sex, and primary cause of ESRD. For all-cause mortality in prevalent patients, Healthy People 2020 sought approximately 0.8% relative annual improvement; actual improvement was 2.7%. Improvement was greatest for patients ages 18-44 years old (3.8%; P<0.01 versus 2.8% for ages 65-74 years old) and 2.3% even for patients ages ≥75 years old. For mortality in incident patients, the relative annual decrease was 2.1% overall, a twofold improvement over the goal; mortality decreased nearly twice as much in black as in white patients (3.2% versus 1.8%; P<0.001). Geographic variation was substantial; the relative annual decrease was 0.6% in the Midwest and more than fourfold greater (2.7%) in the South. Cardiovascular mortality in prevalent patients decreased dramatically at 5.0% per year, far exceeding the annual goal of approximately 0.8%; the decrease was greatest in patients ages ≥75 years old (5.5%; P<0.001 versus ages 65-74 years old; 5.1%). The relative annual increase in percentages of patients with a fistula at dialysis initiation was 2.4%, roughly three times the goal; the increase was greater for black than white patients (3.2% versus 2.3%; P<0.01). Adjusted regional differences varied greater than twofold: 2.0% for the South versus 4.1% for the Midwest. Thus, although gains have been substantial, not all groups have benefitted equally. Goal development for Healthy People 2030 should consider changes in goal paradigms, such as tailoring by geographic region and incorporating patient-centered goals. Copyright © 2016 by the American Society of Nephrology.
Wetmore, James B.; Liu, Jiannong; Li, Suying; Hu, Yan; Peng, Yi; Gilbertson, David T.
2017-01-01
The Healthy People 2020 initiative established goals for patients with CKD and ESRD. We assessed United States progress toward some of these key goals. Using data from the Centers for Medicare and Medicaid Services ESRD database, we created yearly cohorts of patients on incident and prevalent dialysis from 2000 to 2013. Change in event rate or proportion change over the study years was modeled using Poisson regression with adjustment for age, race, sex, and primary cause of ESRD. For all-cause mortality in prevalent patients, Healthy People 2020 sought approximately 0.8% relative annual improvement; actual improvement was 2.7%. Improvement was greatest for patients ages 18–44 years old (3.8%; P<0.01 versus 2.8% for ages 65–74 years old) and 2.3% even for patients ages ≥75 years old. For mortality in incident patients, the relative annual decrease was 2.1% overall, a twofold improvement over the goal; mortality decreased nearly twice as much in black as in white patients (3.2% versus 1.8%; P<0.001). Geographic variation was substantial; the relative annual decrease was 0.6% in the Midwest and more than fourfold greater (2.7%) in the South. Cardiovascular mortality in prevalent patients decreased dramatically at 5.0% per year, far exceeding the annual goal of approximately 0.8%; the decrease was greatest in patients ages ≥75 years old (5.5%; P<0.001 versus ages 65–74 years old; 5.1%). The relative annual increase in percentages of patients with a fistula at dialysis initiation was 2.4%, roughly three times the goal; the increase was greater for black than white patients (3.2% versus 2.3%; P<0.01). Adjusted regional differences varied greater than twofold: 2.0% for the South versus 4.1% for the Midwest. Thus, although gains have been substantial, not all groups have benefitted equally. Goal development for Healthy People 2030 should consider changes in goal paradigms, such as tailoring by geographic region and incorporating patient-centered goals. PMID:27577245
Rivas, Manuel A.; Avila, Brandon E.; Koskela, Jukka; Stevens, Christine; Pirinen, Matti; Neale, Benjamin M.; Ganna, Andrea; Graham, Daniel; Glaser, Benjamin; Peter, Inga; Atzmon, Gil; Barzilai, Nir; Levine, Adam P.; Schiff, Elena; Weisburd, Ben; Lek, Monkol; Bloom, Jonathan; Minikel, Eric V.; Petersen, Britt-Sabina; Beaugerie, Laurent; Seksik, Philippe; Cosnes, Jacques; Schreiber, Stefan; Bokemeyer, Bernd; Bethge, Johannes; Ahmad, Tariq; Plagnol, Vincent; Segal, Anthony W.; Targan, Stephan; Turner, Dan; Saavalainen, Paivi; Farkkila, Martti; Kontula, Kimmo; Palotie, Aarno; Brant, Steven R.; Duerr, Richard H.; Silverberg, Mark S.; Weersma, Rinse K.; Franke, Andre; Jostins, Luke; Barrett, Jeffrey C.; MacArthur, Daniel G.; Jalas, Chaim; Sokol, Harry; Xavier, Ramnik J.; Pulver, Ann; Cho, Judy H.; McGovern, Dermot P. B.; Daly, Mark J.
2018-01-01
As part of a broader collaborative network of exome sequencing studies, we developed a jointly called data set of 5,685 Ashkenazi Jewish exomes. We make publicly available a resource of site and allele frequencies, which should serve as a reference for medical genetics in the Ashkenazim (hosted in part at https://ibd.broadinstitute.org, also available in gnomAD at http://gnomad.broadinstitute.org). We estimate that 34% of protein-coding alleles present in the Ashkenazi Jewish population at frequencies greater than 0.2% are significantly more frequent (mean 15-fold) than their maximum frequency observed in other reference populations. Arising via a well-described founder effect approximately 30 generations ago, this catalog of enriched alleles can contribute to differences in genetic risk and overall prevalence of diseases between populations. As validation we document 148 AJ enriched protein-altering alleles that overlap with "pathogenic" ClinVar alleles (table available at https://github.com/macarthur-lab/clinvar/blob/master/output/clinvar.tsv), including those that account for 10–100 fold differences in prevalence between AJ and non-AJ populations of some rare diseases, especially recessive conditions, including Gaucher disease (GBA, p.Asn409Ser, 8-fold enrichment); Canavan disease (ASPA, p.Glu285Ala, 12-fold enrichment); and Tay-Sachs disease (HEXA, c.1421+1G>C, 27-fold enrichment; p.Tyr427IlefsTer5, 12-fold enrichment). We next sought to use this catalog, of well-established relevance to Mendelian disease, to explore Crohn's disease, a common disease with an estimated two to four-fold excess prevalence in AJ. We specifically attempt to evaluate whether strong acting rare alleles, particularly protein-truncating or otherwise large effect-size alleles, enriched by the same founder-effect, contribute excess genetic risk to Crohn's disease in AJ, and find that ten rare genetic risk factors in NOD2 and LRRK2 are enriched in AJ (p < 0.005), including several novel contributing alleles, show evidence of association to CD. Independently, we find that genomewide common variant risk defined by GWAS shows a strong difference between AJ and non-AJ European control population samples (0.97 s.d. higher, p<10−16). Taken together, the results suggest coordinated selection in AJ population for higher CD risk alleles in general. The results and approach illustrate the value of exome sequencing data in case-control studies along with reference data sets like ExAC (sites VCF available via FTP at ftp.broadinstitute.org/pub/ExAC_release/release0.3/) to pinpoint genetic variation that contributes to variable disease predisposition across populations. PMID:29795570
NASA Technical Reports Server (NTRS)
Tombes, R. M.; Simerly, C.; Borisy, G. G.; Schatten, G.
1992-01-01
During early development, intracellular Ca2+ mobilization is not only essential for fertilization, but has also been implicated during other meiotic and mitotic events, such as germinal vesicle breakdown (GVBD) and nuclear envelope breakdown (NEBD). In this study, the roles of intracellular and extracellular Ca2+ were examined during meiotic maturation and reinitiation at parthenogenetic activation and during first mitosis in a single species using the same methodologies. Cumulus-free metaphase II mouse oocytes immediately resumed anaphase upon the induction of a large, transient Ca2+ elevation. This resumption of meiosis and associated events, such as cortical granule discharge, were not sensitive to extracellular Ca2+ removal, but were blocked by intracellular Ca2+ chelators. In contrast, meiosis I was dependent on external Ca2+; in its absence, the formation and function of the first meiotic spindle was delayed, the first polar body did not form and an interphase-like state was induced. GVBD was not dependent on external Ca2+ and showed no associated Ca2+ changes. NEBD at first mitosis in fertilized eggs, on the other hand, was frequently, but not always associated with a brief Ca2+ transient and was dependent on Ca2+ mobilization. We conclude that GVBD is Ca2+ independent, but that the dependence of NEBD on Ca2+ suggests regulation by more than one pathway. As cells develop from Ca(2+)-independent germinal vesicle oocytes to internal Ca(2+)-dependent pronuclear eggs, internal Ca2+ pools increase by approximately fourfold.
Chen, Xiaochuan; Green, Alice S.; Macko, Antoni R.; Yates, Dustin T.; Kelly, Amy C.
2013-01-01
Intrauterine growth-restricted (IUGR) fetuses experience prolonged hypoxemia, hypoglycemia, and elevated norepinephrine (NE) concentrations, resulting in hypoinsulinemia and β-cell dysfunction. Previously, we showed that acute adrenergic blockade revealed enhanced insulin secretion responsiveness in the IUGR fetus. To determine whether chronic exposure to NE alone enhances β-cell responsiveness afterward, we continuously infused NE into fetal sheep for 7 days and, after terminating the infusion, evaluated glucose-stimulated insulin secretion (GSIS) and glucose-potentiated arginine-induced insulin secretion (GPAIS). During treatment, NE-infused fetuses had greater (P < 0.05) plasma NE concentrations and exhibited hyperglycemia (P < 0.01) and hypoinsulinemia (P < 0.01) compared with controls. GSIS during the NE infusion was also reduced (P < 0.05) compared with pretreatment values. GSIS and GPAIS were approximately fourfold greater (P < 0.01) in NE fetuses 3 h after the 7 days that NE infusion was discontinued compared with age-matched controls or pretreatment GSIS and GPAIS values of NE fetuses. In isolated pancreatic islets from NE fetuses, mRNA concentrations of adrenergic receptor isoforms (α1D, α2A, α2C, and β1), G protein subunit-αi-2, and uncoupling protein 2 were lower (P < 0.05) compared with controls, but β-cell regulatory genes were not different. Our findings indicate that chronic exposure to elevated NE persistently suppresses insulin secretion. After removal, NE fetuses demonstrated a compensatory enhancement in insulin secretion that was associated with adrenergic desensitization and greater stimulus-secretion coupling in pancreatic islets. PMID:24253046
Chen, Po-Wen; Ku, Yu-We; Chu, Fang-Yi
2014-10-01
Bovine lactoferrin (bLf) is a natural glycoprotein, and it shows broad-spectrum antimicrobial activity. However, reports on the influences of bLf on probiotic bacteria have been mixed. We examined the effects of apo-bLf (between 0.25 and 128 mg/mL) on both aerobic and anaerobic cultures of probiotics. We found that bLf had similar effects on the growth of probiotics under aerobic or anaerobic conditions, and that it actively and significantly (at concentrations of >0.25 mg/mL) retarded the growth rate of Bifidobacterium bifidum (ATCC 29521), B. longum (ATCC 15707), B. lactis (BCRC 17394), B. infantis (ATCC 15697), Lactobacillus reuteri (ATCC 23272), L. rhamnosus (ATCC 53103), and L. coryniformis (ATCC 25602) in a dose-dependent manner. Otherwise, minimal inhibitory concentrations (MICs) were 128 or >128 mg/mL against B. bifidum, B. longum, B. lactis, L. reuteri, and L. rhamnosus (ATCC 53103). With regard to MICs, bLf showed at least four-fold lower inhibitory effect on probiotics than on pathogens. Intriguingly, bLf (>0.25 mg/mL) significantly enhanced the growth of Rhamnosus (ATCC 7469) and L. acidophilus (BCRC 14065) by approximately 40-200 %, during their late periods of growth. Supernatants produced from aerobic but not anaerobic cultures of L. acidophilus reduced the growth of Escherichia coli by about 20 %. Thus, bLf displayed a dose-dependent inhibitory effect on the growth of most probiotic strains under either aerobic or anaerobic conditions. An antibacterial supernatant prepared from the aerobic cultures may have significant practical use.
Post-ingestive signals and satiation of water and sodium intake of male rats.
Krause, Eric G; de Kloet, Annette D; Sakai, Randall R
2010-04-19
This study investigated the role of post-ingestive signals in the satiation of thirst or salt appetite. Post-ingestive signals, defined as those arising from the passage of fluid into the duodenum and proximal jejunum, were manipulated by implanting rats with gastric fistulas. After recovery, rats were water deprived and the following day gastric fistulas were opened (sham-drinking) or closed (control). Deprivation-induced thirst significantly increased water intake with sham-drinking rats consuming four-fold more than controls after 120 min access. Subsequently, rats were given sodium deficient chow for 48 h and the next day were administered furosemide and urine was collected. Twenty-four hours later, gastric fistulas were manipulated and rats were given water and 0.5M NaCl and intakes were measured. After 120 min of access, rats were sacrificed and plasma sodium (pNa) and plasma-renin-activity (PRA) were measured. Furosemide resulted in a loss of 2.2 mEq of sodium in urine and sham-drinking rats consumed significantly more water and 0.5M NaCl when compared to controls. At 120 min sham-drinking rats consumed 7.5 mEq of sodium nearly twice that of controls but had significantly lower pNa and significantly increased PRA. Interestingly, the ratio of water to 0.5M NaCl intake was similar in both groups, with each making a mixture of approximately 0.25 M NaCl. The results suggest that post-ingestive signals are necessary for the satiation of thirst and salt appetite. (c) 2010 Elsevier Inc. All rights reserved.
Ishii, H; Wada, M; Furuya, Y; Nagano, N; Nemeth, E F; Fox, J
2000-02-01
The calcium receptor agonist (calcimimetic) compound NPS R-568 causes rapid decreases in circulating levels of parathyroid hormone (PTH) in rats and humans. We hypothesized that daily intermittent decreases in serum PTH levels may have different effects on bone than do chronically sustained decreases. To test this hypothesis, we compared two NPS R-568 dosing regimens in rats with chronic renal insufficiency induced by two intravenous injections of adriamycin. Fourteen weeks after the second adriamycin injection, creatinine clearance was reduced by 52%, PTH levels were elevated approximately 2.5-fold, and serum 25(OH)D3 and 1,25(OH)2D3 levels were reduced substantially. Treatment by daily per os gavage, which decreased PTH levels intermittently, or continuous subcutaneous infusion, which resulted in a sustained suppression of serum PTH levels, then began for 8 weeks. Despite the hyperparathyroidism, the adriamycin-injected rats developed a low-turnover bone lesion with osteomalacia (fourfold increase in osteoid volume in the proximal tibial metaphysis) and osteopenia (67% decrease in cancellous bone volume and an 18% reduction in bone mineral density at the distal femur). Daily administered (but not infused) NPS R-568 significantly increased cancellous bone volume solely by normalizing trabecular thickness, and increased femoral bone mineral density by 14%. These results indicate that daily intermittent, but not sustained, decreases in PTH levels have an "anabolic-like" effect on bones with a low-turnover lesion in this animal model of chronic renal insufficiency.
Develop and Manufacture an airlock sliding tray
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lawton, Cindy M.
2014-02-26
The goal of this project is to continue to develop an airlock sliding tray and then partner with an industrial manufacturing company for production. The sliding tray will be easily installed into and removed from most glovebox airlocks in a few minutes. Technical Approach: A prototype of a sliding tray has been developed and tested in the LANL cold lab and 35 trays are presently being built for the plutonium facility (PF-4). The current, recently approved design works for a 14-inch diameter round airlock and has a tray length of approximately 20 inches. The grant will take the already testedmore » and approved round technology and design for the square airlock. These two designs will be suitable for the majority of the existing airlocks in the multitude of DOE facilities. Partnering with an external manufacturer will allow for production of the airlock trays at a much lower cost and increase the availability of the product for all DOE sites. Project duration is estimated to be 12-13 months. Benefits: The purpose of the airlock sliding trays is fourfold: 1) Mitigate risk of rotator cuff injuries, 2) Improve ALARA, 3) Reduce risk of glovebox glove breaches and glove punctures, and 4) Improve worker comfort. I have had the opportunity to visit many other DOE facilities including Savannah, Y-12, ORNL, Sandia, and Livermore for assistance with ergonomic problems and/or injuries. All of these sites would benefit from the airlock sliding tray and I can assume all other DOE facilities with gloveboxes built prior to 1985 could also use the sliding trays.« less
Three-dimensional diffuse optical mammography with ultrasound localization in a human subject
NASA Astrophysics Data System (ADS)
Holboke, Monica J.; Tromberg, Bruce J.; Li, Xingde; Shah, Natasha; Fishkin, Joshua B.; Kidney, D.; Butler, J.; Chance, Britton; Yodh, Arjun G.
2000-04-01
We describe an approach that combines clinical ultrasound and photon migration techniques to enhance the sensitivity and information content of diffuse optical tomography. Measurements were performed on a postmenopausal woman with a single 1.8 X 0.9 cm malignant ductal carcinoma in situ approximately 7.4 mm beneath the skin surface (UCI IRB protocol 95-563). The ultrasound-derived information about tumor geometry enabled us to segment the breast tissue into tumor and background regions. Optical data was obtained with a multifrequency, multiwavelength hand-held frequency-domain photon migration backscattering probe. The optical properties of the tumor and background were then computed using the ultrasound-derived geometrical constraints. An iterative perturbative approach, using parallel processing, provided quantitative information about scattering and absorption simultaneously with the ability to incorporate and resolve complex boundary conditions and geometries. A three to four fold increase in the tumor absorption coefficient and nearly 50% reduction in scattering coefficient relative to background was observed ((lambda) equals 674, 782, 803, and 849 nm). Calculations of the mean physiological parameters reveal fourfold greater tumor total hemoglobin concentration [Hbtot] than normal breast (67 (mu) M vs 16 (mu) M) and tumor hemoglobin oxygen saturation (SOx) values of 63% (vs 73% and 68% in the region surrounding the tumor and the opposite normal tissue, respectively). Comparison of semi-infinite to heterogeneous models shows superior tumor/background contrast for the latter in both absorption and scattering. Sensitivity studies assessing the impact of tumor size and refractive index assumptions, as well as scan direction, demonstrate modest effects on recovered properties.
Comparison of holding strength of suture anchors for hepatic and renal parenchyma.
Ames, Caroline D; Perrone, Juan M; Frisella, Alison J; Morrissey, Kevin; Landman, Jaime
2005-12-01
Various laparoscopic devices have been described for suture anchoring during solidorgan parenchymal closure. Application of these devices expedites the closure of parenchymal defects and minimizes ischemia time. We compared different technologies as suture anchors for parenchymal closure. A tensometer was used to determine the amount of tension necessary to dislodge each of five different clips from Vicryl suture alone or against two different substrates (fresh pig kidney and liver) with and without an intervening pledget. The clips investigated were the Lapra-Ty (Ethicon), Endoclip II (US Surgical), small Horizon Ligating Clips (Weck), Hem-o-lok Medium Polymer Clips (Week), and a novel Suture-clip (Applied Medical). ANOVA and two-sided Fisher's exact test provided statistical analysis. The force required to dislodge the Lapra-Ty clip from bare suture for both 0 and 1 Vicryl (7.0 N) was approximately fourfold the force required to dislodge the Endoclips or the 5-mm or 10-mm Hem-o-lok clips (p<0.01). When clips were applied to suture running through renal or liver parenchyma, the novel Suture-clip required the greatest tension to dislodge (P<0.01), followed by the Horizon and Lapra-Ty clips. There were no statistically significant differences in the tension required to dislodge a given clip from the two parenchymal substrates or in the presence or absence of a pledget. In our experimental model, the Suture-clip, Lapra-Ty, and Horizon clips required significantly greater tension to dislodge than the Hem-o-lok and Endoclip clips. The addition of a pledget did not improve tension resistance.
Surgical Management of Pediatric Epilepsy: Decision-Making and Outcomes.
Kellermann, Tanja S; Wagner, Janelle L; Smith, Gigi; Karia, Samir; Eskandari, Ramin
2016-11-01
First-line treatment for epilepsy is antiepileptic drug and requires an interdisciplinary approach and enduring commitment and adherence from the patient and family for successful outcome. Despite adherence to antiepileptic drugs, refractory epilepsy occurs in approximately 30% of children with epilepsy, and surgical treatment is an important intervention to consider. Surgical management of pediatric epilepsy is highly effective in selected patients with refractory epilepsy; however, an evidence-based protocol, including best methods of presurgical imaging assessments, and neurodevelopmental and/or behavioral health assessments, is not currently available for clinicians. Surgical treatment of epilepsy can be critical to avoid negative outcomes in functional, cognitive, and behavioral health status. Furthermore, it is often the only method to achieve seizure freedom in refractory epilepsy. Although a large literature base can be found for adults with refractory epilepsy undergoing surgical treatment, less is known about how surgical management affects outcomes in children with epilepsy. The purpose of the review was fourfold: (1) to evaluate the available literature regarding presurgical assessment and postsurgical outcomes in children with medically refractory epilepsy, (2) to identify gaps in our knowledge of surgical treatment and its outcomes in children with epilepsy, (3) to pose questions for further research, and (4) to advocate for a more unified presurgical evaluation protocol including earlier referral for surgical candidacy of pediatric patients with refractory epilepsy. Despite its effectiveness, epilepsy surgery remains an underutilized but evidence-based approach that could lead to positive short- and long-term outcomes for children with refractory epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.
Wang, Zhen; Li, Ru; Yu, Guolin
2017-01-01
In this work, several extended approximately invex vector-valued functions of higher order involving a generalized Jacobian are introduced, and some examples are presented to illustrate their existences. The notions of higher-order (weak) quasi-efficiency with respect to a function are proposed for a multi-objective programming. Under the introduced generalization of higher-order approximate invexities assumptions, we prove that the solutions of generalized vector variational-like inequalities in terms of the generalized Jacobian are the generalized quasi-efficient solutions of nonsmooth multi-objective programming problems. Moreover, the equivalent conditions are presented, namely, a vector critical point is a weakly quasi-efficient solution of higher order with respect to a function.
Cation coordination in oxychloride glasses
NASA Astrophysics Data System (ADS)
Johnson, J. A.; Holland, D.; Bland, J.; Johnson, C. E.; Thomas, M. F.
2003-02-01
Glasses containing mixtures of cations and anions of nominal compositions [Sb2O3]x - [ZnCl2]1-x where x = 0.25, 0.50, 0.75, and 1.00, have been studied by means of neutron diffraction and Raman and Mössbauer spectroscopy. There is preferential bonding within the system with the absence of Sb-Cl bonds. Antimony is found to be threefold coordinated to oxygen, and zinc fourfold coordinated. The main contributing species are of the form [Sb(OSb)2(OZn)] and [Zn(ClZn)2(OSb)2].
Spatiotemporal light-beam compression from nonlinear mode coupling
NASA Astrophysics Data System (ADS)
Krupa, Katarzyna; Tonello, Alessandro; Couderc, Vincent; Barthélémy, Alain; Millot, Guy; Modotto, Daniele; Wabnitz, Stefan
2018-04-01
We experimentally demonstrate simultaneous spatial and temporal compression in the propagation of light pulses in multimode nonlinear optical fibers. We reveal that the spatial beam self-cleaning recently discovered in graded-index multimode fibers is accompanied by significant temporal reshaping and up to fourfold shortening of the injected subnanosecond laser pulses. Since the nonlinear coupling among the modes strongly depends on the instantaneous power, we explore the entire range of the nonlinear dynamics with a single optical pulse, where the optical power is continuously varied across the pulse profile.
Chloridotetrakis(pyridine-4-carbaldehyde-κN)copper(II) chloride
Meng, Xiu-Jin; Zhang, Shu-Hua; Yang, Ge-Ge; Huang, Xue-Ren; Jiang, Yi-Min
2009-01-01
In the molecular structure of the title compound, [CuCl(C6H5NO)4]Cl, the CuII atom is coordinated by four N atoms of four pyridine-4-carboxaldehyde ligands and one chloride anion in a slightly distorted square-pyramidal coordination geometry. There is also a non-coordinating Cl− anion in the crystal structure. The CuII atom and both Cl atoms are situated on fourfold rotation axes. A weak C—H⋯Cl interaction is also present. PMID:21578129
Varandas, A J C; Sarkar, B
2011-05-14
Generalized Born-Oppenheimer equations including the geometrical phase effect are derived for three- and four-fold electronic manifolds in Jahn-Teller systems near the degeneracy seam. The method is readily extendable to N-fold systems of arbitrary dimension. An application is reported for a model threefold system, and the results are compared with Born-Oppenheimer (geometrical phase ignored), extended Born-Oppenheimer, and coupled three-state calculations. The theory shows unprecedented simplicity while depicting all features of more elaborated ones.
Effects of prolonged exposure to space flight factors for 175 days on lettuce seeds
NASA Astrophysics Data System (ADS)
Nevzgodina, L. V.; Maximova, E. N.; Akatov, Yu. A.
We have studied the effects of prolonged (up to 175 days) exposure of Lactuca sativa seeds to space flight factors, including primary cosmic radiation heavy ions. The data obtained evidence a significant fourfold increase ofs pontaneous mutagenesis in seeds both with regard to the total number of aberrant cells as well as the formation of single cells with multiple aberrations. Comparison of the present experiment with earlier works shows that the frequency of such aberrations increases with the duration of the flight.
McDonnell, Liam A; Heeren, Ron M A; de Lange, Robert P J; Fletcher, Ian W
2006-09-01
To expand the role of high spatial resolution secondary ion mass spectrometry (SIMS) in biological studies, numerous developments have been reported in recent years for enhancing the molecular ion yield of high mass molecules. These include both surface modification, including matrix-enhanced SIMS and metal-assisted SIMS, and polyatomic primary ions. Using rat brain tissue sections and a bismuth primary ion gun able to produce atomic and polyatomic primary ions, we report here how the sensitivity enhancements provided by these developments are additive. Combined surface modification and polyatomic primary ions provided approximately 15.8 times more signal than using atomic primary ions on the raw sample, whereas surface modification and polyatomic primary ions yield approximately 3.8 and approximately 8.4 times more signal. This higher sensitivity is used to generate chemically specific images of higher mass biomolecules using a single molecular ion peak.
Gary, Tiffany L; Stark, Sarah A; LaVeist, Thomas A
2007-06-01
Aspects of the environment in which one lives are increasingly being recognized as major contributors to health, yet few empirical studies have focused on mental health. Therefore, we sought to determine if neighborhood characteristics were associated with mental health outcomes among 1408 African-American (59.3%) and white (40.7%) adults living in a socio-economically homogeneous, racially integrated, urban community in Baltimore, MD. Among African Americans and whites, the perception of severe problems in the community was associated with higher levels of stress (approximately 1.8 units higher), anxiety (approximately 1.8 units higher), and depression (OR= approximately 2.0) compared to those who perceived no or few problems (all p<0.05). Community cohesion, the perception that people generally work together, was associated with better mental health among whites only. These findings give further insight into the complex environment of inner-city communities.
Patients With Carbon Monoxide Poisoning and Subsequent Dementia
Lai, Ching-Yuan; Huang, Yu-Wei; Tseng, Chun-Hung; Lin, Cheng-Li; Sung, Fung-Chang; Kao, Chia-Hung
2016-01-01
Abstract The present study evaluated the dementia risk after carbon monoxide poisoning (CO poisoning). Using the National Health Insurance Research Database of Taiwan, a total of 9041 adults newly diagnosed with CO poisoning from 2000 to 2011 were identified as the CO poisoning cohort. Four-fold (N = 36,160) of non-CO poisoning insured people were randomly selected as controls, frequency-matched by age, sex, and hospitalization year. Incidence and hazard ratio (HR) of dementia were measured by the end 2011. The dementia incidence was 1.6-fold higher in the CO exposed cohort than in the non-exposed cohort (15.2 vs 9.76 per 10,000 person-years; n = 62 vs 174) with an adjusted HR of 1.50 (95% CI = 1.11–2.04). The sex- and age-specific hazards were higher in male patients (adjusted HR = 1.74, 95% CI = 1.20–2.54), and those aged <=49 years (adjusted HR = 2.62, 95% CI = 1.38–4.99). CO exposed patients with 7-day or longer hospital stay had an adjusted HR of 2.18 (95% CI = 1.42, 3.36). The CO poisoning patients on hyperbaric oxygen (HBO2) therapy had an adjusted HR of 1.80 (95% CI = 0.96–3.37). This study suggests that CO poisoning may have association with the risk of developing dementia, which is significant for severe cases. The effectiveness of HBO2 therapy remains unclear in preventing dementia. Patients with CO poisoning are more prevalent with depression. PMID:26735545
Schraegle, William A; Titus, Jeffrey B
2017-10-01
Children and adolescents with epilepsy often show higher rates of anxiety, which carries an increased risk for reduced health-related quality of life (HRQOL). The current study assessed the role of parental psychiatric history (i.e., anxiety, depression, and/or bipolar disorder) on the rate of anxiety features in youth seen in a tertiary epilepsy clinic. Data included parental ratings on the Behavior Assessment System for Children (BASC-2) and the Quality of Life in Childhood Epilepsy (QOLCE) questionnaire for 180 children and adolescents (mean age=11.40, SD=3.98). Our results identified clinically elevated anxiety ratings in nearly half the sample (47%) with previous psychiatric history endorsed by 48% of parents. The effect of parental psychiatric history on youth anxiety was found to be significant and associated with a threefold increase in the rate of youth anxiety features. This risk increased to fourfold in refractory epilepsy, and the impact of family psychiatric history is greater in adolescent females and in families that report higher levels of stress. In those families who reported no psychiatric history, anxiety was best predicted by epilepsy-specific factors above and beyond sociodemographic factors. Parental psychiatric history was also identified as a significant risk factor for diminished patient HRQOL, even after accounting for seizure control. These findings highlight the impact of family and epilepsy factors on psychological functioning and offer further support for the strong relationship between parental adjustment and child outcome in pediatric epilepsy. Copyright © 2017 Elsevier Inc. All rights reserved.
Interstitial plasmin activity with epsilon aminocaproic acid: temporal and regional heterogeneity.
Reust, Daryl L; Reeves, Scott T; Abernathy, James H; Dixon, Jennifer A; Gaillard, William F; Mukherjee, Rupak; Koval, Christine N; Stroud, Robert E; Spinale, Francis G
2010-05-01
Epsilon aminocaproic acid (EACA) is used in cardiac surgery to modulate plasmin activity (PLact). The present study developed a fluorogenic-microdialysis system to measure in vivo region specific temporal changes in PLact after EACA administration. Pigs (25 to 35 kg) received EACA (75 mg/kg, n = 7) or saline in which microdialysis probes were placed in the liver, myocardium, kidney, and quadricep muscle. The microdialysate contained a plasmin-specific fluorogenic peptide and fluorescence emission, which directly reflected PLact, determined at baseline, 30, 60, 90, and 120 minutes after EACA/vehicle infusion. Epsilon aminocaproic acid caused significant decreases in liver and quadricep PLact at 60, 90, 120 minutes, and at 30, 60, and 120 minutes, respectively (p < 0.05). In contrast, EACA induced significant biphasic changes in heart and kidney PLact profiles with initial increases followed by decreases at 90 and 120 minutes (p < 0.05). The peak EACA interstitial concentrations for all compartments occurred at 30 minutes after infusion, and were fivefold higher in the renal compartment and fourfold higher in the myocardium, when compared with the liver or muscle (p < 0.05). Using a large animal model and in vivo microdialysis measurements of plasmin activity, the unique findings from this study were twofold. First, EACA induced temporally distinct plasmin activity profiles within the plasma and interstitial compartments. Second, EACA caused region-specific changes in plasmin activity profiles. These temporal and regional heterogeneic effects of EACA may have important therapeutic considerations when managing fibrinolysis in the perioperative period. Copyright (c) 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
Slade, Eric P; Stuart, Elizabeth A; Salkever, David S; Karakus, Mustafa; Green, Kerry M; Ialongo, Nicholas
2008-05-01
Age of onset of substance use disorders in adolescence and early adulthood could be associated with higher rates of adult criminal incarceration in the U.S., but evidence of these associations is scarce. Propensity score matching was used to estimate the association between adolescent-onset substance use disorders and the rate of incarceration, as well as incarceration costs and self-reported criminal arrests and convictions, of young men predominantly from African American, lower income, urban households. Age of onset was differentiated by whether onset of the first disorder occurred by age 16. Onset of a substance use disorder by age 16, but not later onset, was associated with a fourfold greater risk of adult incarceration for substance related offenses as compared to no disorder (0.35 vs. 0.09, P=0.044). Onset by age 16 and later onset were both positively associated with incarceration costs and risk of arrest and conviction, though associations with crime outcomes were more consistent with respect to onset by age 16. Results were robust to propensity score adjustment for observable predictors of substance use in adolescence and involvement in crime as an adult. Among young men in this high risk minority sample, having a substance use disorder by age 16 was associated with higher risk of incarceration for substance related offenses in early adulthood and with more extensive criminal justice system involvement as compared to having no disorder or having a disorder beginning at a later age.
Vitamin E supplementation does not prevent ethanol-reduced hepatic retinoic acid levels in rats
Chung, Jayong; Veeramachaneni, Sudipta; Liu, Chun; Mernitz, Heather; Russell, Robert M.; Wang, Xiang-Dong
2009-01-01
Chronic, excessive ethanol intake can increase retinoic acid (RA) catabolism by inducing cytochrome P450 2E1 (CYP2E1). Vitamin E (VE) is an antioxidant implicated in CYP2E1 inhibition. In the current study, we hypothesized that VE supplementation inhibits CYP2E1 and decreases RA catabolism, thereby preventing ethanol-induced hepatocyte hyperproliferation. For 1 month, four groups of Sprague-Dawley rats were fed a Lieber-DeCarli liquid ethanol (36% of the total calories) diet as follows: either ethanol alone (Alc group) or ethanol in combination with 0.1 mg/kg body wt of all-trans RA (Alc+RA group), 2 mg/kg body wt of VE (Alc+VE group), or both together (Alc+RA+VE group). Control rats were pair-fed a liquid diet with an isocaloric amount of maltodextrin instead of ethanol. The ethanol-fed groups had three-fold higher hepatic CYP2E1 levels, 50% lower hepatic RA levels, and significantly increased hepatocyte proliferation when compared with the controls. The ethanol-fed rats given VE had more than four-fold higher hepatic VE concentrations than did ethanol-fed rats without VE, but this did not prevent ethanol induction of CYP2E1, lower hepatic retinoid levels, or hepatocellular hyperproliferation. Further, VE supplementation could not prevent RA catabolism in liver microsomal fractions of the ethanol-fed rats in vitro. These results show that VE supplementation can neither inhibit ethanol-induced changes in RA catabolism nor prevent ethanol-induced hepatocyte hyperproliferation in the rat liver. PMID:19854382
Ross, Claire L; Schoepf, Verena; DeCarlo, Thomas M; McCulloch, Malcolm T
2018-05-30
High-latitude coral reefs provide natural laboratories for investigating the mechanisms and limits of coral calcification. While the calcification processes of tropical corals have been studied intensively, little is known about how their temperate counterparts grow under much lower temperature and light conditions. Here, we report the results of a long-term (2-year) study of seasonal changes in calcification rates, photo-physiology and calcifying fluid (cf) chemistry (using boron isotope systematics and Raman spectroscopy) for the coral Turbinaria reniformis growing near its latitudinal limits (34.5° S) along the southern coast of Western Australia. In contrast with tropical corals, calcification rates were found to be threefold higher during winter (16 to 17° C) compared with summer (approx. 21° C), and negatively correlated with light, but lacking any correlation with temperature. These unexpected findings are attributed to a combination of higher chlorophyll a, and hence increased heterotrophy during winter compared with summer, together with the corals' ability to seasonally modulate pH cf , with carbonate ion concentration [Formula: see text] being the main controller of calcification rates. Conversely, calcium ion concentration [Ca 2+ ] cf declined with increasing calcification rates, resulting in aragonite saturation states Ω cf that were stable yet elevated fourfold above seawater values. Our results show that corals growing near their latitudinal limits exert strong physiological control over their cf in order to maintain year-round calcification rates that are insensitive to the unfavourable temperature regimes typical of high-latitude reefs. © 2018 The Author(s).
Nielsen, M-C; Teulon, D A J; Chapman, R B; Butler, R C; Drayton, G M; Philipsen, H
2010-04-01
Two strains of western flower thrips, Frankliniella occidentalis (Pergande), are reputedly found in New Zealand. One strain was recorded in 1934, and it is most common in flowers of Lupinus arboreus outdoors (lupin strain); the other strain was first recorded in New Zealand in 1992 and is found mostly indoors on greenhouse crops (greenhouse strain). Laboratory studies were conducted to compare the life history parameters of these two strains. Thrips from each strain were fed sucrose solution and capsicum or lupin pollen and reared at 25 degrees C, >60% RH, and 16 L:8 D photoperiod. Significant differences in life history parameters were found. Preoviposition time was significantly shorter, and oviposition rate and fecundity were markedly higher (four-fold) for the greenhouse than for the lupin strain. The lupin strain performed significantly better on the capsicum pollen, laying more than twice as many eggs than on the lupin pollen over a 14-d period. The greenhouse strain development time from larvae to adult was marginally faster (0.7-1.1 d less) than the lupin strain because of a shorter prepupal and a marginally shorter pupal development time. Females of the greenhouse strain lived on average 69% longer than females from the lupin strain. Large differences in the intrinsic growth rate (r(m)) were found, with r(m) being 1.4-1.8 times higher for the greenhouse strain than the lupin strain, depending on pollen source. The results are discussed in relation to different ecological requirements and pest status of the two strains.
Virokannas, H
1995-01-01
OBJECTIVES--31 railway workers and 32 lumberjacks were examined to compare the dose-response relation between the exposure to two types of hand-arm vibration and the sensory disturbances in peripheral nerves as evaluated by the vibration perception thresholds (VPTs). METHODS--Clinical examinations were carried out that included measurements of the VPTs, and electroneuromyography (ENMG), and an inquiry to confirm the use of vibrating tools. Diseases of the central nervous system and neuropathies were checked by inquiry and a clinical examination, diabetes was excluded by a blood sample analysis, and the subjects with carpal tunnel syndrome confirmed with ENMG were excluded from the study. RESULTS--Lifetime use of hand held tamping machines (railway workers) and chain saws (lumberjacks) had a significant correlation with the VPTs at frequencies from 32 to 500 Hz. The increase of the VPTs (250 Hz) in relation to use of vibrating tools was 1.8-fold higher on average in the whole group and 2.3-fold higher in the young (< 45) railway workers who had used hand held tamping machines, than in the corresponding groups of lumberjacks, who had used chain saws, whereas the frequency weighted acceleration of vibration in tamping machines was fourfold. CONCLUSION--There was a significant dose-response relation between the exposure to hand-arm vibration and the VPTs. The VPTs as a function of the frequency weighted acceleration of vibration and the exposure to vibration gave promising results for assessment of the risk of damage to sensory nerves induced by vibration. PMID:7795756
Kemppainen, Laura M; Kemppainen, Teemu T; Reippainen, Jutta A; Salmenniemi, Suvi T; Vuolanto, Pia H
2018-06-01
The aim of this research was to study health-related and sociodemographic determinants of the use of different complementary and alternative medicine (CAM) treatments in Europe and differences in CAM use in various European countries. The study was based on a design-based logistic regression analysis of the European Social Survey (ESS), Round 7. We distinguished four CAM modalities: manual therapies, alternative medicinal systems, traditional Asian medical systems and mind-body therapies. In total, 25.9% of the general population had used CAM during the last 12 months. Typically, only one CAM treatment had been used, and it was used more often as complementary rather than alternative treatment. The use of CAM varied greatly by country, from 10% in Hungary to almost 40% in Germany. Compared to those in good health, the use of CAM was two to fourfold greater among those with health problems. The health profiles of users of different CAM modalities varied. For example, back or neck pain was associated with all types of CAM, whereas depression was associated only with the use of mind-body therapies. Individuals with difficult to diagnose health conditions were more inclined to utilize CAM, and CAM use was more common among women and those with a higher education. Lower income was associated with the use of mind-body therapies, whereas the other three CAM modalities were associated with higher income. Help-seeking differed according to the health problem, something that should be acknowledged by clinical professionals to ensure safe care. The findings also point towards possible socioeconomic inequalities in health service use.
de Blasio, B F; Xue, Y; Iversen, B; Gran, J Michael
2012-08-16
The impact of influenza on work absenteeism is poorly documented. We used data from the national registry and Norway Post AS (>14,000 employees) to explore sickness absence patterns from 2005/06 through 2009/10 in Norway. Annually, an estimated 2.868% (mean 95% confidence interval (CI): 2.405-4.820%) of the working population obtained sick leave for influenza, of whom 0.915% (mean 95% CI: 0.453-1.590%) had diagnoses for other respiratory illnesses with influenza as underlying cause. In the 2009/10 pandemic season, the absence rate increased 1.5-fold, mainly due to a 73% increase in influenza-diagnosed sick leaves. At Norway Post AS, absence related to seasonal influenza accounted for 0.351% (mean 95% CI: 0.126-0.704%) of total person-days annually (excluding parental care absence), of which 32-43% were estimated to be self-certified. Medically certified sick leave increased 1.3-fold in the pandemic season to 0.458% (95% CI: 0.176-0.856), while self-certified sick leave remained at a level typical for seasonal influenza. We found a significant four-fold increase in work loss to care for sick children, 0.048% (95% CI: 0.031-0.070%) of person-days, compared with 0.012% (95% CI: 0.004-0.028%) in 2008/09. In conclusion, GP-certified and parental care work absence were higher in the pandemic season. More studies are needed to quantify the burden of self-certified sick leave.
Variationally consistent approximation scheme for charge transfer
NASA Technical Reports Server (NTRS)
Halpern, A. M.
1978-01-01
The author has developed a technique for testing various charge-transfer approximation schemes for consistency with the requirements of the Kohn variational principle for the amplitude to guarantee that the amplitude is correct to second order in the scattering wave functions. Applied to Born-type approximations for charge transfer it allows the selection of particular groups of first-, second-, and higher-Born-type terms that obey the consistency requirement, and hence yield more reliable approximation to the amplitude.
Fire increases carbon fluxes from inland waters of the Yukon-Kuskokwim delta, Alaska.
NASA Astrophysics Data System (ADS)
Mann, P. J.; Bristol, E. M.; Dabrowski, J. S.; Jimmie, J. A.; Melton, S.; Navarro-Perez, E.; Peter, D. L.; Sae-lim, N.; Holmes, R. M.; Natali, S.; Schade, J. D.
2017-12-01
Climate change across high-latitude regions is expected to alter the hydrology and biogeochemistry of arctic environments, significantly impacting ecosystem C cycling and landscape scale C budgets. Fire represents one manifestation of arctic climate change with the number, extent and intensity of fires projected to increase over upcoming decades. The Yukon-Kuskokwim River Delta (YKD), Alaska, experienced unprecedented tundra fires in 2015 when more than 250 km2 underwent burn. In this study, we examined the effects of the 2015 YKD fire upon aquatic and terrestrial C fluxes, and investigated potential mechanisms causing changes to C-cycling. Field work was conducted during summer months (July-Sept) over two years, complimented with aerobic and anaerobic laboratory incubations. Burning of the terrestrial organic layer caused dramatic changes to soil moisture, the proportion of organic versus mineral soils near the land surface, and average active layer depth. Fire caused increased C fluxes (particularly CH4) from re-wet soils relative to unburnt soils, suggesting an interaction exists between fire history and soil moisture. Higher C fluxes from saturated ponds and fens across the landscape provided additional support for this theory. Pore-water chemistry in burnt catchments contained higher inorganic nutrient concentrations, specifically nitrogen, potentially driven by changing soil sorption processes and/ or infiltration rates. Organic matter delivery to inland waters within burns contained DOC of lower apparent molecular weight and aromaticity relative to unburnt waters (inferred from optical measures), and waters typically had higher temperatures, pH and dissolved mineral content. Lake and low-lying pond CO2 and CH4 emissions were consistently higher in burn catchment regions, with three to four-fold higher C emission rates. Our study indicates that fire may promote aquatic and terrestrial pathways for C loss and that these enhanced emissions may persist for years following disturbance. A greater understanding of the divergent responses of soils and inland waters after burn and how these drive changes to CO2 and CH4 production are necessary to predict the impact of climate change on landscape C chemistry and fluxes in the future.
Dangisso, Mesay Hailu; Datiko, Daniel Gemechu; Lindtjørn, Bernt
2014-01-01
Background Ethiopia is one of the high tuberculosis (TB) burden countries. An analysis of trends and differentials in case notifications and treatment outcomes of TB may help improve our understanding of the performance of TB control services. Methods A retrospective trend analysis of TB cases was conducted in the Sidama Zone in southern Ethiopia. We registered all TB cases diagnosed and treated during 2003–2012 from all health facilities in the Sidama Zone, and analysed trends of TB case notification rates and treatment outcomes. Results The smear positive (PTB+) case notification rate (CNR) increased from 55 (95% CI 52.5–58.4) to 111 (95% CI 107.4–114.4) per 105 people. The CNRs of PTB+ in people older than 45 years increased by fourfold, while the mortality of cases during treatment declined from 11% to 3% for smear negative (PTB-) (X2 trend, P<0.001) and from 5% to 2% for PTB+ (X2 trend, P<0.001). The treatment success was higher in rural areas (AOR 1.11; CI 95%: 1.03–1.2), less for PTB- (AOR 0.86; CI 95%: 0.80–0.92) and higher for extra-pulmonary TB (AOR 1.10; CI 95%: 1.02–1.19) compared to PTB+. A higher lost-to-follow up was observed in men (AOR 1.15; CI 95%: 1.06–1.24) and among PTB- cases (AOR 1.14; CI 95%: 1.03–1.25). More deaths occurred in PTB-cases (AOR 1.65; 95% CI: 1.44–1.90) and among cases older than 65 years (AOR 3.86; CI 95%: 2.94–5.10). Lastly, retreatment cases had a higher mortality than new cases (6% vs 3%). Conclusion Over the past decade TB CNRs and treatment outcomes improved, whereas the disparities of disease burden by gender and place of residence reduced and mortality declined. Strategies should be devised to address higher risk groups for poor treatment outcomes. PMID:25460363
Lehtonen, J Y; Kinnunen, P K
1997-01-01
The well-characterized integral membrane protein lactose (lac) permease from Escherichia coli was reconstituted together with trace amounts (molar fraction X = 0.005 of the total phospholipid) of different pyrene-labeled phospholipid analogs into 1-palmitoyl-2-oleoyl-sn-glycero-3-sn-glycero-3-phospho-rac'-glycerol (POPG) liposomes. Effects of lac permease on bilayer lipid dynamics were investigated by measuring the excimer-to-monomer fluorescence intensity ratio IE/IM. Compared to control vesicles, the presence of lac permease (at a protein:phospholipid stoichiometry P/L of 1:4.000) increased the rate of excimer formation by 1-palmitoyl-2[6-(pyren-1-yl)]decanoyl-sn-glycero-3-phosphocholine (PPDPC) by approximately fivefold. Decreasing P/L from approximately 1:4.000 to 1:7.600 decreased the IE/IM for PPDPC from 0.16 to 0.05, respectively. An increase in bilayer fluidity due to permease is unlikely, thus implying that the augmented IE/IM should arise from partial lateral segregation of PPDPC in the vesicles. This notion is supported by the further 38% increase in IE/IM observed for the pyrene-labeled Cys-148 lac permease reconstituted into POPG vesicles at P/L 1:4000. The importance of the length of the lipid-protein boundary is implicated by the reduction in IE/IM resulting from the aggregation of the lac permease in vesicles by a monoclonal antibody. Interestingly, excimer formation by 1-palmitoyl-2[6-(pyren-1-yl)hexanoyl-sn-glycero-3-phosphocholine (PPHPC) was enhanced only fourfold in the presence of lac permease. Results obtained with the corresponding pyrenyl phosphatidylglycerols and -methanols were qualitatively similar to those above, thus indicating that lipid headgroup-protein interactions are not involved. Inclusion of 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamino-N-(5-fluoresce inthio- carbamoyl) (DPPF, X = 0.005) into reconstituted lactose permease vesicles containing PPDPC caused a nearly 90% decrease in excimer fluorescence, whereas in control vesicles lacking the reconstituted protein only 40% quenching was evident. The addition of 1,2-dipalmitoyl-sn-glycero-3-phospho-rac'-glycerol (DPPG) decreased IE/IM for PPDPC, revealing the driving force for the lateral segregation of this probe to become attenuated. More specifically for protein-free bilayers at XDPPG = 0.10 the rate of lateral diffusion of PPDPC in POPG is diminished, as evidenced by the 24% decrement in IE/IM, under these conditions the increase in IE/IM due to lac permease was strongly reduced, by approximately 84%. The present data are interpreted in terms of the hydrophobic mismatch theory, which predicts that integral membrane proteins will draw lipids of similar hydrophobic thickness into their vicinity. In brief, the approximate lengths of most of the predicted 12 hydrophobic, membrane-spanning alpha-helical segments of lactose permease range between 28.5 and 37.5 A and thus exceed the hydrophobic thickness of POPG of approximately 25.8 A. Therefore, to reduce the free energy of the assembly, longer lipids such as PPDPC and DPPF are accumulated in the immediate vicinity of lactose permease in fluid, liquid crystalline POPG bilayers. PMID:9138570
Cosmological collapse and the improved Zel'dovich approximation.
NASA Astrophysics Data System (ADS)
Salopek, D. S.; Stewart, J. M.; Croudace, K. M.; Parry, J.
Using a general relativistic formulation, the authors show how to compute the higher order terms in the Zel'dovich approximation which describes cosmological collapse. They evolve the 3-metric in a spatial gradient expansion. Their method is an advance over earlier work because it is local at each order. Using the improved Zel'dovich approximation, they compute the epoch of collapse.
Stratum corneum cytokines and skin irritation response to sodium lauryl sulfate.
De Jongh, Cindy M; Verberk, Maarten M; Withagen, Carien E T; Jacobs, John J L; Rustemeyer, Thomas; Kezic, Sanja
2006-06-01
Little is known about cytokines involved in chronic irritant contact dermatitis. Individual cytokine profiles might explain at least part of the differences in the individual response to irritation. Our objective was to investigate the relation between baseline stratum corneum (SC) cytokine levels and the skin response to a single and a repeated irritation test. This study also aimed to determine changes in SC cytokine levels after repeated irritation. Transepidermal water loss (TEWL) and erythema were measured in 20 volunteers after single 24-hr exposure to 1% sodium lauryl sulfate (SLS), and during and after repeated exposure to 0.1% SLS over a 3-week period. SC cytokine levels were measured from an unexposed skin site and from the repeatedly exposed site. Interleukin (IL)-1alpha decreased by 30% after repeated exposure, while IL-1RA increased 10-fold and IL-8 increased fourfold. Baseline IL-1RA and IL-8 values were predictors of TEWL and erythema after single exposure (r = 0.55-0.61). 6 subjects showed barrier recovery during repeated exposure. Baseline IL-1RA and IL-8 levels are likely to be indicators of higher skin irritability after single exposure to SLS. Barrier repair in some of the subjects might explain the lack of agreement between the TEWL response after single and repeated irritation.
A Pervaporation Study of Ammonia Solutions Using Molecular Sieve Silica Membranes
Yang, Xing; Fraser, Thomas; Myat, Darli; Smart, Simon; Zhang, Jianhua; Diniz da Costa, João C.; Liubinas, Audra; Duke, Mikel
2014-01-01
An innovative concept is proposed to recover ammonia from industrial wastewater using a molecular sieve silica membrane in pervaporation (PV), benchmarked against vacuum membrane distillation (VMD). Cobalt and iron doped molecular sieve silica-based ceramic membranes were evaluated based on the ammonia concentration factor downstream and long-term performance. A modified low-temperature membrane evaluation system was utilized, featuring the ability to capture and measure ammonia in the permeate. It was found that the silica membrane with confirmed molecular sieving features had higher water selectivity over ammonia. This was due to a size selectivity mechanism that favoured water, but blocked ammonia. However, a cobalt doped silica membrane previously treated with high temperature water solutions demonstrated extraordinary preference towards ammonia by achieving up to a 50,000 mg/L ammonia concentration (a reusable concentration level) measured in the permeate when fed with 800 mg/L of ammonia solution. This exceeded the concentration factor expected by the benchmark VMD process by four-fold, suspected to be due to the competitive adsorption of ammonia over water into the silica structure with pores now large enough to accommodate ammonia. However, this membrane showed a gradual decline in selectivity, suspected to be due to the degradation of the silica material/pore structure after several hours of operation. PMID:24957120
Meuser, Thomas M.; Carr, David B.; Ulfarsson, Gudmundur F.
2009-01-01
The identification and evaluation of medically impaired drivers is an important safety issue. Medical fitness to drive is applicable to all ages but is particularly salient for older adults. Voluntary procedures, whereby various professionals and family members may report medical fitness concerns to State driver license bureaus, are common in the United States. This paper examines traffic crashes of drivers reported during 2001–2005 under the State of Missouri’s voluntary reporting law (House Bill HB-1536) and the resulting licensing outcomes. Missouri’s law is non-specific as to age, but the mean age of reported drivers was 80. Reports were submitted by police officers (30%), license office staff (27%), physicians (20%), family members (16%), and others (7%). The most common medical condition was dementia/cognitive (45%). Crash history for reported drivers was higher than that of controls, dating back to 1993, reaching a peak in 2001 when the crash involvement of reported drivers was 9.3% vs. 2.2% for controls—a fourfold difference. The crash involvement of reported drivers decreased rapidly after, indicating the impact of HB-1536 reporting with subsequent license revocation and to a lesser degree, mortality. Of the 4,100 reported individuals, 144 (3.5%) retained a driver’s license after the process. PMID:19245882
System-Level Testing of the Advanced Stirling Radioisotope Generator Engineering Hardware
NASA Technical Reports Server (NTRS)
Chan, Jack; Wiser, Jack; Brown, Greg; Florin, Dominic; Oriti, Salvatore M.
2014-01-01
To support future NASA deep space missions, a radioisotope power system utilizing Stirling power conversion technology was under development. This development effort was performed under the joint sponsorship of the Department of Energy and NASA, until its termination at the end of 2013 due to budget constraints. The higher conversion efficiency of the Stirling cycle compared with that of the Radioisotope Thermoelectric Generators (RTGs) used in previous missions (Viking, Pioneer, Voyager, Galileo, Ulysses, Cassini, Pluto New Horizons and Mars Science Laboratory) offers the advantage of a four-fold reduction in Pu-238 fuel, thereby extending its limited domestic supply. As part of closeout activities, system-level testing of flight-like Advanced Stirling Convertors (ASCs) with a flight-like ASC Controller Unit (ACU) was performed in February 2014. This hardware is the most representative of the flight design tested to date. The test fully demonstrates the following ACU and system functionality: system startup; ASC control and operation at nominal and worst-case operating conditions; power rectification; DC output power management throughout nominal and out-of-range host voltage levels; ACU fault management, and system command / telemetry via MIL-STD 1553 bus. This testing shows the viability of such a system for future deep space missions and bolsters confidence in the maturity of the flight design.
NASA Astrophysics Data System (ADS)
Hu, Bo; He, Wei; Ye, Jun; Tang, Jin; Syed Sheraz, Ahmad; Zhang, Xiang-Qun; Cheng, Zhao-Hua
2015-01-01
Buffer layer provides an opportunity to enhance the quality of ultrathin magnetic films. In this paper, Co films with different thickness of CoSi2 buffer layers were grown on Si (001) substrates. In order to investigate morphology, structure, and magnetic properties of films, scanning tunneling microscope (STM), low energy electron diffraction (LEED), high resolution transmission electron microscopy (HRTEM), and surface magneto-optical Kerr effect (SMOKE) were used. The results show that the crystal quality and magnetic anisotropies of the Co films are strongly affected by the thickness of CoSi2 buffer layers. Few CoSi2 monolayers can prevent the interdiffusion of Si substrate and Co film and enhance the Co film quality. Furthermore, the in-plane magnetic anisotropy of Co film with optimal buffer layer shows four-fold symmetry and exhibits the two-jumps of magnetization reversal process, which is the typical phenomenon in cubic (001) films. Project supported by the National Basic Research Program of China (Grant Nos. 2011CB921801 and 2012CB933102), the National Natural Science Foundation of China (Grant Nos. 11374350, 11034004, 11274361, and 11274033), and the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20131102130005).
Magnusson, Björn; Ekstrand, Eva-Maria; Karlsson, Anna; Ejlertsson, Jörgen
2018-05-01
The activated sludge process within the pulp and paper industry is generally run to minimize the production of waste activated sludge (WAS), leading to high electricity costs from aeration and relatively large basin volumes. In this study, a pilot-scale activated sludge process was run to evaluate the concept of treating the wastewater at high rate with a low sludge age. Two 150 L containers were used, one for aeration and one for sedimentation and sludge return. The hydraulic retention time was decreased from 24 hours to 7 hours, and the sludge age was lowered from 12 days to 2-4 days. The methane potential of the WAS was evaluated using batch tests, as well as continuous anaerobic digestion (AD) in 4 L reactors in mesophilic and thermophilic conditions. Wastewater treatment capacity was increased almost four-fold at maintained degradation efficiency. The lower sludge age greatly improved the methane potential of the WAS in batch tests, reaching 170 NmL CH 4 /g VS at a sludge age of 2 days. In addition, the continuous AD showed a higher methane production at thermophilic conditions. Thus, the combination of high-rate wastewater treatment and AD of WAS is a promising option for the pulp and paper industry.
Risk taking in general practice: GP out-of-hours referrals to hospital.
Ingram, Jenny C; Calnan, Michael W; Greenwood, Rosemary J; Kemple, Terry; Payne, Sarah; Rossdale, Michael
2009-01-01
Emergency admissions to hospital at night and weekends are distressing for patients and disruptive for hospitals. Many of these admissions result from referrals from GP out-of-hours (OOH) providers. To compare rates of referral to hospital for doctors working OOH before and after the new general medical services contract was introduced in Bristol in 2005; to explore the attitudes of GPs to referral to hospital OOH; and to develop an understanding of the factors that influence GPs when they refer patients to hospital. Cross-sectional comparison of admission rates; postal survey. Three OOH providers in south-west England. Referral rates were compared for 234 GPs working OOH, and questionnaires explored their attitudes to risk. There was no change in referral rates after the change in contract or in the greater than fourfold variation between those with the lowest and highest referral rates found previously. Female GPs made fewer home visits and had a higher referral rate for patients seen at home. One-hundred and fifty GPs responded to the survey. Logistic regression of three combined survey risk items, sex, and place of visit showed that GPs with low 'tolerance of risk' scores were more likely to be high referrers to hospital (P<0.001). GPs' threshold of risk is important for explaining variations in referral to hospital.
Teulier, Loic; Dégletagne, Cyril; Rey, Benjamin; Tornos, Jérémy; Keime, Céline; de Dinechin, Marc; Raccurt, Mireille; Rouanet, Jean-Louis; Roussel, Damien; Duchamp, Claude
2012-01-01
The passage from shore to marine life of juvenile penguins represents a major energetic challenge to fuel intense and prolonged demands for thermoregulation and locomotion. Some functional changes developed at this crucial step were investigated by comparing pre-fledging king penguins with sea-acclimatized (SA) juveniles (Aptenodytes patagonicus). Transcriptomic analysis of pectoralis muscle biopsies revealed that most genes encoding proteins involved in lipid transport or catabolism were upregulated, while genes involved in carbohydrate metabolism were mostly downregulated in SA birds. Determination of muscle enzymatic activities showed no changes in enzymes involved in the glycolytic pathway, but increased 3-hydroxyacyl-CoA dehydrogenase, an enzyme of the β-oxidation pathway. The respiratory rates of isolated muscle mitochondria were much higher with a substrate arising from lipid metabolism (palmitoyl-l-carnitine) in SA juveniles than in terrestrial controls, while no difference emerged with a substrate arising from carbohydrate metabolism (pyruvate). In vivo, perfusion of a lipid emulsion induced a fourfold larger thermogenic effect in SA than in control juveniles. The present integrative study shows that fuel selection towards lipid oxidation characterizes penguin acclimatization to marine life. Such acclimatization may involve thyroid hormones through their nuclear beta receptor and nuclear coactivators. PMID:22357259
Anthropocene Survival of Southern New England's Salt ...
In southern New England, salt marshes are exceptionally vulnerable to the impacts of accelerated sea level rise. Regional rates of sea level rise have been as much as 50 % greater than the global average over past decades, a more than fourfold increase over late Holocene background values. In addition, coastal development blocks many potential marsh migration routes, and compensatory mechanisms relying on positive feedbacks between inundation and sediment deposition are insufficient to counter inundation increases in extreme low-turbidity tidal waters. Accordingly, multiple lines of evidence suggest that marsh submergence is occurring in southern New England. A combination of monitoring data, field re-surveys, radiometric dating, and analysis of peat composition have established that, beginning in the early and mid-twentieth century, the dominant low-marsh plant, Spartina alterniflora, has encroached upward in tidal marshes, and typical high-marsh plants, including Juncus gerardii and Spartina patens, have declined, providing strong evidence that vegetation changes are being driven, at least in part, by higher water levels. Additionally, aerial and satellite imagery show shoreline retreat, widening and headward extension of channels, and new and expanded interior depressions. Papers in this special section highlight changes in marsh-building processes, patterns of vegetation loss, and shifts in species composition. The final papers turn to strategies for minimiz
Asgari, Maryam M; Warton, E Margaret; Whittemore, Alice S
2015-04-01
The contribution of family history to cutaneous squamous cell carcinoma (SCC) risk has not been systematically quantified. To examine the association between self-reported family history of skin cancer and SCC risk. Cases (n = 415) with a pathology-verified SCC and 415 age-, gender-, and race-matched controls were identified within a large integrated health care delivery system. Family history and skin cancer risk factors were ascertained by survey. Odds ratios (ORs) for associations of SCC with family history of skin cancer were estimated using conditional logistic regression adjusted for environmental and innate SCC risk factors. Any known family history of skin cancer was associated with a four-fold higher risk of SCC, adjusting for known environmental and innate SCC risk factors (OR, 4.0; confidence interval [CI]: 2.5-6.5). An unknown family history of skin cancer showed similar risk for SCC (OR, 3.9; CI: 2.4-6.5). In models including skin cancer type, the strongest association was for family history of basal cell carcinoma (OR, 9.8; CI: 2.6-36.8) and for multiple skin cancer types (OR, 10.5; CI: 3.7-29.6). Family history of skin cancer is an important independent risk factor for cutaneous SCCs.
Hybrid nanocatalysts containing enzymes and metallic nanoparticles for ethanol/O2 biofuel cell
NASA Astrophysics Data System (ADS)
Aquino Neto, S.; Almeida, T. S.; Palma, L. M.; Minteer, S. D.; de Andrade, A. R.
2014-08-01
We report the preparation of hybrid nanostructured bioanodes containing the enzyme alcohol dehydrogenase (ADH) with either Au, Pt, or Pt0.75Sn0.25 nanoparticles for use in ethanol/O2 hybrid biofuel cells. We describe two different methodologies for the preparation of the bioanodes: in a first case, multi walled carbon nanotubes (MWCNTs) were employed as a support for the metallic nanoparticles and TBAB-modified Nafion® aided enzyme immobilization. In the second case, we immobilized the enzymes using dendrimers-encapsulated nanoparticles as the agent for enzyme anchoring. The biofuel cell tests showed that the addition of metallic nanoparticles to the bioanode structure enhanced the overall biofuel cell performance. The bioelectrode containing Au nanoparticles displaying the best performance, with an open circuit potential of 0.61 ± 0.05 V and a maximum power density of 155 ± 11 μW cm-2. NADH cyclic voltammetric experiments indicated that Au nanoparticles behaved as a catalyst toward NADH oxidation. Comparing the two protocols we used to synthetized nanoparticles, the sample containing the Au nanoparticles supported on MWCNTs furnished fourfold higher values. Therefore, from the satisfactory results obtained, it can be inferred that the combination of small amounts of metallic nanoparticles with enzymes improve bioanode performance.
Campbell, Sandra; Roux, Nicolette; Preece, Cilla; Rafter, Eileen; Davis, Bronwyn; Mein, Jackie; Boyle, Jacqueline; Fredericks, Bronwyn; Chamberlain, Catherine
2017-11-01
Aim To understand enablers and barriers influencing postpartum screening for type 2 diabetes following gestational diabetes in Australian Indigenous women and how screening might be improved. Australian Indigenous women with gestational diabetes mellitus (GDM) are less likely than other Australian women to receive postpartum diabetes screening. This is despite a fourfold higher risk of developing type 2 diabetes within eight years postpartum. We conducted interviews with seven Indigenous women with previous GDM, focus groups with 20 Indigenous health workers and workshops with 24 other health professionals. Data collection included brainstorming, visualisation, sorting and prioritising activities. Data were analysed thematically using the Theoretical Domains Framework. Barriers are presented under the headings of 'capability', 'motivation' and 'opportunity'. Enabling strategies are presented under 'intervention' and 'policy' headings. Findings Participants generated 28 enabling environmental, educational and incentive interventions, and service provision, communication, guideline, persuasive and fiscal policies to address barriers to screening and improve postpartum support for women. The highest priorities included providing holistic social support, culturally appropriate resources, improving Indigenous workforce involvement and establishing structured follow-up systems. Understanding Indigenous women's perspectives, developing strategies with health workers and action planning with other health professionals can generate context-relevant feasible strategies to improve postpartum care after GDM. Importantly, we need evidence which can demonstrate whether the strategies are effective.
NASA Astrophysics Data System (ADS)
McIntyre, R. E.; Grierson, P. F.; Adams, M. A.
2005-05-01
Riparian systems are hotspots in dryland landscapes for nutrient supply and transformation. Biogeochemical fluxes in riparian systems are closely coupled to hydrological flowpaths, which, in dryland regions, are characterised by catastrophic flooding and long periods of erratic or no flow. Re-wetting of soils stimulates soil microbial processes that drive mineralization of nutrients necessary for plant growth. We present here the first data of a 3-year research project investigating biogeochemical processes in riparian systems in the semi-arid Pilbara region of Western Australia. Spatial patterns of nitrogen, phosphorus and carbon were closely related to topographic zone (across floodplain and channels) and vegetation type. NO3- and PCi concentrations were four-fold higher in channel, bank and riparian soils than in soils of floodplain and riparian-floodplain transition zones. Nitrogen distribution was highly heterogeneous in riparian soils (NO3- CV=102%, NH4+ CV=84%) while phosphorus was particularly heterogeneous in floodplain soils (PCi CV=153%, PCo CV=266%), in comparison to other zones. Phospholipid fatty acid (PLFA) and enzymatic profiles will be used to assess microbial functional groups, combined with mineralisation experiments and stable isotope studies (15N and 13C). These data will improve understanding of biogeochemical cycling in dryland riparian systems, and contribute to improved regional management of water resources.
Effects of pancreatic polypeptide on motilin and circulating metabolites in man.
Adrian, T E; Greenberg, G R; Barnes, A J; Christofides, N D; Alberti, K G; Bloom, S R
1980-06-01
Pancreatic polypeptide was infused intravenously in healthy fasting subjects at 1 pmol kg-1 (n = 7) and 4 pmol kg-1 min-1 (n = 10) producing plasma PP concentrations of 223 +/- 37 pmol/l (mean +/- SEM) and 891 +/- 64 pmol/l respectively. These levels are similar to and four-fold higher than those seen after a normal mixed breakfast in healthy young adults. In a separate study five healthy subjects ingested a small breakfast during infusion of PP on different days at 1 pmol kg-1 min-1 and 2 pmol kg-1 min-1 respectively. PP at 1 pmol kg-1 min-1 caused a marked reduction in fasting plasma motilin concentrations to 20% of the basal level (p less than 0.001). There were, however, no significant changes in plasma concentrations of insulin, glucagon, gastrin, secretin, enteroglucagon, gastric inhibitory peptide or neurotensin. Despite previous reports possibly implicating PP in metabolism, there were no significant effects on blood levels of glucose, alanine lactate, 3-hydroxybutyrate, glycerol or non-esterified fatty acids, either in the fasting state or after the ingestion of food. Although it seems unlikely that PP is a major hormonal regulator of intermediary metabolism in man, its ability to suppress motilin at physiological concentrations suggests the possibility of an indirect influence on digestive motor function.
NASA Astrophysics Data System (ADS)
Brandstetter, Birgit; Ruther, Joachim
2016-06-01
The availability of linoleic acid (LA; C18:2∆9,12) is pivotal for animals. While vertebrates depend on a nutritional supply, some invertebrates, including the parasitic wasp Nasonia vitripennis, are able to synthesize LA from oleic acid (OA; C18:1∆9). This raises the question as to whether these animals nevertheless benefit from the additional uptake of LA with the diet. LA plays an important role in the sexual communication of N. vitripennis because males use it as a precursor for the synthesis of an abdominal sex pheromone attracting virgin females. We reared hosts of N. vitripennis that were fed diets enriched in the availability of stearic acid (SA: C18:0), OA or LA. N. vitripennis males developing on the different host types clearly differed in both the fatty acid composition of their body fat and sex pheromone titres. Males from LA-enriched hosts had an almost fourfold higher proportion of LA and produced significantly more sex pheromone than males from SA (2.2-fold) and OA (1.4-fold) enriched hosts, respectively. Our study demonstrates that animals being able to synthesize important nutrients de novo may still benefit from an additional supply with their diet.
Karna, Sanjay; Mahat, Meg; Choi, Tae-Youl; Shimada, Ryoko; Wang, Zhiming; Neogi, Arup
2016-11-22
The light emission from reduced graphene oxide quantum dots (rGO-QDs) exhibit a significant enhancement in photoluminescence (PL) due to localized surface plasmon (LSP) interactions. Silver and gold nanoparticles (NPs) coupled to rGO nanoparticles exhibit the effect of resonant LSP coupling on the emission processes. Enhancement of the radiative recombination rate in the presence of Ag-NPs induced LSP tuned to the emission energy results in a four-fold increase in PL intensity. The localized field due to the resonantly coupled LSP modes induces n-π* transitions that are not observed in the absence of the resonant interaction of the plasmons with the excitons. An increase in the density of the Ag-NPs result in a detuning of the LSP energy from the emission energy of the nanoparticles. The detuning is due to the cumulative effect of the red-shift in the LSP energy and the electrostatic field induced blue shift in the PL energy of the rGO-QDs. The detuning quenches the PL emission from rGO-QDs at higher concentration of Ag NPs due to non-dissipative effects unlike plasmon induced Joule heating that occurs under resonance conditions. An increase in Au nanoparticles concentration results in an enhancement of PL emission due to electrostatic image charge effect.
Increased Mercury Levels in Patients with Celiac Disease following a Gluten-Free Regimen
Elli, Luca; Rossi, Valentina; Conte, Dario; Ronchi, Anna; Tomba, Carolina; Passoni, Manuela; Bardella, Maria Teresa; Roncoroni, Leda; Guzzi, Gianpaolo
2015-01-01
Background and Aim. Although mercury is involved in several immunological diseases, nothing is known about its implication in celiac disease. Our aim was to evaluate blood and urinary levels of mercury in celiac patients. Methods. We prospectively enrolled 30 celiac patients (20 treated with normal duodenal mucosa and 10 untreated with duodenal atrophy) and 20 healthy controls from the same geographic area. Blood and urinary mercury concentrations were measured by means of flow injection inductively coupled plasma mass spectrometry. Enrolled patients underwent dental chart for amalgam fillings and completed a food-frequency questionnaire to evaluate diet and fish intake. Results. Mercury blood/urinary levels were 2.4 ± 2.3/1.0 ± 1.4, 10.2 ± 6.7/2.2 ± 3.0 and 3.7 ± 2.7/1.3 ± 1.2 in untreated CD, treated CD, and healthy controls, respectively. Resulting mercury levels were significantly higher in celiac patients following a gluten-free diet. No differences were found regarding fish intake and number of amalgam fillings. No demographic or clinical data were significantly associated with mercury levels in biologic samples. Conclusion. Data demonstrate a fourfold increase of mercury blood levels in celiac patients following a gluten-free diet. Further studies are needed to clarify its role in celiac mechanism. PMID:25802516
Keitel, W A; Bond, N L; Zahradnik, J M; Cramton, T A; Robbins, J B
1994-01-01
Clinical and serum antibody responses following intramuscular injection of two formulations of Salmonella typhi Vi capsular polysaccharide (Vi) were assessed in a double-blind evaluation. Healthy adults were randomly assigned to receive a 25 micrograms dose of liquid (Vi-Liq; n = 182) or freeze-dried Vi vaccine (Vi-Lyoph; n = 55), or placebo (n = 86). Erythema and/or induration > or = 1 cm in diameter at the injection site developed in 13/182 (7%) of Vi-Liq and 3/55 (5%) of Vi-Lyoph recipients (not significant, n.s.). Fever (oral temperature > or = 100 degrees F (37.8 degrees C)) occurred in < 2% of vaccinees. The frequencies of rises of fourfold or greater and of maximal Vi antibody levels were similar in the two vaccine groups. Fourfold or greater rises in serum Vi antibody levels (RIA) developed in 53% of Vi-Lyoph and 60% of Vi-Liq recipients by 1 week (n.s.), and 98 and 93%, respectively, by 1 month (n.s.). The frequencies of adverse reactions and mean Vi antibody levels following booster immunization with Vi-Liq 27 to 34 months after primary immunization (n = 55) were similar to those observed following primary immunization, although subjects given a booster dose were more likely to develop local reactions > or = 1 cm in diameter than those given a first dose (10/55 versus 13/182, p = 0.013 by the chi 2 test). Primary and booster immunizations with the Vi vaccines are well tolerated in healthy adults; mean Vi antibody levels remain significantly elevated for up to 34 months after primary immunization.
Alkafafy, Mohamed El-Sayed; Ibrahim, Zein Shaban; Ahmed, Mohamed Mohamed; El-Shazly, Samir Ahmed
2015-06-01
The current work was undertaken to settle the debate about the toxicity of artificial sweeteners (AS), particularly aspartame and saccharin. Twenty-five, 7-week-old male Wistar albino rats with an average body weight of 101 ± 4.8 g were divided into a control group and four experimental groups (n = 5 rats). The first and second experimental groups received daily doses equivalent to the acceptable daily intake (ADI) of aspartame (250 mg/Kg BW) and four-fold ADI of aspartame (1000 mg/Kg BW). The third and fourth experimental groups received daily doses equivalent to ADI of saccharin (25 mg/Kg BW) and four-fold ADI of saccharin (100 mg/Kg BW). The experimental groups received the corresponding sweetener dissolved in water by oral route for 8 weeks. The activities of enzymes relevant to liver functions and antioxidants were measured in the blood plasma. Histological studies were used for the evaluation of the changes in the hepatic tissues. The gene expression levels of the key oncogene (h-Ras) and the tumor suppressor gene (P27) were also evaluated. In addition to a significant reduction in the body weight, the AS-treated groups displayed elevated enzymes activities, lowered antioxidants values, and histological changes reflecting the hepatotoxic effect of aspartame and saccharin. Moreover, the overexpression of the key oncogene (h-Ras) and the downregulation of the tumor suppressor gene (P27) in all treated rat groups may indicate a potential risk of liver carcinogenesis, particularly on long-term exposure. © The Author(s) 2015.
Wairkar, Sarika; Gaud, Ram; Jadhav, Namdeo
2017-09-01
Nateglinide, an Antidiabetic drug (BCS II), shows pH-dependent solubility and variable bioavailability. The purpose of study was to increase dissolution and bioavailability of Nateglinide by development of its microenvironmental pH-regulated ternary solid dispersion (MeSD). MeSD formulation of Nateglinide, poloxamer-188 and Na 2 CO 3 was prepared by melt dispersion in 1 : 2 : 0.2 w/w ratio and further characterised for solubility, In-vitro dissolution, microenvironmental pH, crystallinity/amorphism, physicochemical interactions, bioavailability in Wistar rats. Solubility of Nateglinide was increased notably in MeSD, and its in-vitro dissolution study showed fourfold increase in the dissolution, particularly in 1.2 pH buffer. Prominent reduction in the peak intensity of X-ray powder diffraction (XRPD) and absence of endotherm in DSC thermogram confirmed the amorphism of Nateglinide in MeSD. Attenuated total reflectance Fourier transform infrared spectra revealed the hydrogen bond interactions between Nateglinide and poloxamer-188. In-vivo study indicated that MeSD exhibited fourfold increase in area under curve over Nateglinide. Tmax of MeSD was observed at 0.25 h, which is beneficial for efficient management of postprandial sugar. Instead of mere transformation of the Nateglinide to its amorphous form as evidenced by DSC and XRPD, formation of a soluble carboxylate compound of Nateglinide in MeSD was predominantly responsible for dissolution and bioavailability enhancement. The study demonstrates the utility of MeSD in achieving pH-independent dissolution, reduced T max and enhanced bioavailability of Nateglinide. © 2017 Royal Pharmaceutical Society.
Short and medium range structures of 80GeSe2–20Ga2Se3 chalcogenide glasses
NASA Astrophysics Data System (ADS)
Petracovschi, Elena; Calvez, Laurent; Cormier, Laurent; Le Coq, David; Du, Jincheng
2018-05-01
The short and medium range structures of 80GeSe2–20Ga2Se3 (or Ge23.5Ga11.8Se64.7) chalcogenide glasses have been studied by combining ab initio molecular dynamics (AIMD) simulations and experimental neutron diffraction studies. The structure factor and total correlation function were calculated from glass structures generated from AIMD simulations and compared with neutron diffraction experiments showing reasonable agreement. The atomic structures of ternary chalcogenide glasses were analyzed in detail, and it was found that gallium atoms are four-fold coordinated by selenium (Se) and form [GaSe4] tetrahedra. Germanium atoms on average also have four-fold coordination, among which Se is 3.5 with the remaining being Ge–Ge homo-nuclear bonds. Ga and Ge tetrahedra link together mainly through corner-sharing and some edge-sharing of Se. No homo-nuclear bonds were observed among Ga atoms or between Ge and Ga. In addition, Se–Se homo-nuclear bonds and Se chains with various lengths were observed. A small fraction of Se atom triclusters that bond to three cations of Ge and Ga were also observed, confirming earlier proposals from 77Se solid state nuclear magnetic resonance studies. Furthermore, the electronic structures of ternary chalcogenide glasses were studied in terms of atomic charge and electronic density of states in order to gain insights into the chemical bonding and electronic properties, as well as to provide an explanation of the observed atomic structures in these ternary chalcogenide glasses.