Enhancement of NH3 gas sensitivity at room temperature by carbon nanotube-based sensor coated with Co nanoparticles.

PubMed

Nguyen, Lich Quang; Phan, Pho Quoc; Duong, Huyen Ngoc; Nguyen, Chien Duc; Nguyen, Lam Huu

2013-01-30

Multi-walled carbon nanotube (MWCNT) film has been fabricated onto Pt-patterned alumina substrates using the chemical vapor deposition method for NH(3) gas sensing applications. The MWCNT-based sensor is sensitive to NH(3) gas at room temperature. Nanoclusters of Co catalysts have been sputtered on the surface of the MWCNT film to enhance gas sensitivity with respect to unfunctionalized CNT films. The gas sensitivity of Co-functionalized MWCNT-based gas sensors is thus significantly improved. The sensor exhibits good repeatability and high selectivity towards NH(3), compared with alcohol and LPG.

Demonstration of zero bias responsivity in MBE grown β-Ga2O3 lateral deep-UV photodetector

NASA Astrophysics Data System (ADS)

Singh Pratiyush, Anamika; Krishnamoorthy, Sriram; Kumar, Sandeep; Xia, Zhanbo; Muralidharan, Rangarajan; Rajan, Siddharth; Nath, Digbijoy N.

2018-06-01

We demonstrate zero-bias spectral responsivity in MBE-grown β-Ga2O3 planar UV-C detector with good linearity up to optical power density of 4.6 mW cm‑2. Devices with asymmetrical metal contacts were realized on 150 nm thick β-Ga2O3 films on sapphire. The device exhibited a spectral responsivity of 1.4 mA W‑1 at 255 nm under zero-bias condition, dark current <10 nA at 15 V and UV-to-visible rejection ratio ∼105 at 5 V. The demonstrated UV-C detector exhibited an estimated high detectivity of 2.0 × 1012 Jones at 1 V and were found to be very stable and repeatable, suggesting its potential use for focal plane arrays.

A Palladium-Tin Modified Microband Electrode Array for Nitrate Determination

PubMed Central

Fu, Yexiang; Bian, Chao; Kuang, Jian; Wang, Jinfen; Tong, Jianhua; Xia, Shanhong

2015-01-01

A microband electrode array modified with palladium-tin bimetallic composite has been developed for nitrate determination. The microband electrode array was fabricated by Micro Electro-Mechanical System (MEMS) technique. Palladium and tin were electrodeposited successively on the electrode, forming a double-layer structure. The effect of the Pd-Sn composite was investigated and its enhancement of catalytic activity and lifetime was revealed. The Pd-Sn modified electrode showed good linearity (R2 = 0.998) from 1 mg/L to 20 mg/L for nitrate determination with a sensitivity of 398 μA/(mg∙L−1∙cm2). The electrode exhibited a satisfying analytical performance after 60 days of storage, indicating a long lifetime. Good repeatability was also displayed by the Pd-Sn modified electrodes. The results provided an option for nitrate determination in water. PMID:26389904

Highly sensitive copper fiber-in-tube solid-phase microextraction for online selective analysis of polycyclic aromatic hydrocarbons coupled with high performance liquid chromatography.

PubMed

Sun, Min; Feng, Juanjuan; Bu, Yanan; Luo, Chuannan

2015-08-21

A fiber-in-tube solid-phase microextraction (SPME) device was developed with copper wire and copper tube, which was served as both the substrate and sorbent with high physical strength and good flexibility. Its morphology and surface properties were characterized by scanning electron microscopy and energy dispersive X-ray spectrometry. It was coupled with high performance liquid chromatography (HPLC) equipment by replacing the sample loop of six-port injection valve, building the online SPME-HPLC system conveniently. Using ten polycyclic aromatic hydrocarbons (PAHs) as model analytes, extraction conditions including sampling rate, extraction time, organic content and desorption time were investigated and optimized. The copper fiber-in-tube exhibits excellent extraction efficiency toward PAHs, with enrichment factors from 268 to 2497. The established online SPME-HPLC method provides good linearity (0.05-100μgL(-1)) and low detection limits (0.001-0.01μgL(-1)) for PAHs. It has been used to determine PAHs in water samples, with recoveries in the range of 86.2-115%. Repeatability on the same extraction tube is in the range of 0.6-3.6%, and repeatability among three tubes is in the range of 5.6-20.1%. Compared with phthalates, anilines and phenols, the copper fiber-in-tube possesses good extraction selectivity for PAHs. The extraction mechanism is probably related to hydrophobic interaction and π-electron-metal interaction. Copyright © 2015 Elsevier B.V. All rights reserved.

Selectivity of hexaphenylbenzene-based hydrocarbon stationary phase with propeller-like conformation for aromatic and aliphatic isomers.

PubMed

Yang, Yinhui; Chang, Zhengfeng; Yang, Xiaohong; Qi, Meiling; Wang, Jinliang

2018-08-03

Herein we report a propeller-like hexaphenylbenzene-based hydrocarbon material (denoted as BT) as the stationary phase for capillary gas chromatography (GC). The statically-coated BT capillary column showed a high column efficiency of 4340 plates m -1 and weak polarity. Owing to its unique conformation, π-electron toroidal delocalization and intrinsic microporosity, the BT stationary phase exhibited interesting selectivity for aromatic compounds over alkanes. Compared with the graphene (G) column, the BT column showed much prolonged retention and high selectivity for aromatic isomers, especially methylnaphthalenes, dimethylnaphthalenes and phenanthrene/anthracene, mainly because of its propeller-like conformation with rich intercalation effects. Moreover, it exhibited good column repeatability (intra-day, inter-day) and reproducibility (between-column) with RSD values on the retention times less than 0.08% for intra-day, 0.32% for inter-day and 3.8% for between-column, respectively. Also, it showed good potential for determination of minor isomer impurities in real samples. To the best of our knowledge, this work presents the first example of employing an neat aromatic hydrocarbon material as the GC stationary phase with high selectivity for analytes of a wide ranging polarity. Copyright © 2018 Elsevier B.V. All rights reserved.

Enhancement of NH3 Gas Sensitivity at Room Temperature by Carbon Nanotube-Based Sensor Coated with Co Nanoparticles

PubMed Central

Nguyen, Lich Quang; Phan, Pho Quoc; Duong, Huyen Ngoc; Nguyen, Chien Duc; Nguyen, Lam Huu

2013-01-01

Multi-walled carbon nanotube (MWCNT) film has been fabricated onto Pt-patterned alumina substrates using the chemical vapor deposition method for NH3 gas sensing applications. The MWCNT-based sensor is sensitive to NH3 gas at room temperature. Nanoclusters of Co catalysts have been sputtered on the surface of the MWCNT film to enhance gas sensitivity with respect to unfunctionalized CNT films. The gas sensitivity of Co-functionalized MWCNT-based gas sensors is thus significantly improved. The sensor exhibits good repeatability and high selectivity towards NH3, compared with alcohol and LPG. PMID:23364198

Development of highly-ordered, ferroelectric inverse opal films using sol gel infiltration

NASA Astrophysics Data System (ADS)

Matsuura, N.; Yang, S.; Sun, P.; Ruda, H. E.

2005-07-01

Highly-ordered, ferroelectric, Pb-doped Ba0.7Sr0.3TiO3, inverse opal films were fabricated by spin-coating a sol gel precursor into a polystyrene artificial opal template followed by heat treatment. Thin films of the ferroelectric were independently studied and were shown to exhibit good dielectric properties and high refractive indices. The excellent quality of the final inverse opal film using this spin-coating infiltration method was confirmed by scanning electron microscopy images and the good correspondence between optical reflection data and theoretical simulations. Using this method, the structural and material parameters of the final ferroelectric inverse opal film were easily adjusted by template heating and through repeated infiltrations, without changes in the initial template or precursor. Also, crack-free inverse opal thin films were fabricated over areas comparable to that of the initial crack-free polystyrene template (˜100 by 100 μm2).

Statistical Methodology for the Analysis of Repeated Duration Data in Behavioral Studies.

PubMed

Letué, Frédérique; Martinez, Marie-José; Samson, Adeline; Vilain, Anne; Vilain, Coriandre

2018-03-15

Repeated duration data are frequently used in behavioral studies. Classical linear or log-linear mixed models are often inadequate to analyze such data, because they usually consist of nonnegative and skew-distributed variables. Therefore, we recommend use of a statistical methodology specific to duration data. We propose a methodology based on Cox mixed models and written under the R language. This semiparametric model is indeed flexible enough to fit duration data. To compare log-linear and Cox mixed models in terms of goodness-of-fit on real data sets, we also provide a procedure based on simulations and quantile-quantile plots. We present two examples from a data set of speech and gesture interactions, which illustrate the limitations of linear and log-linear mixed models, as compared to Cox models. The linear models are not validated on our data, whereas Cox models are. Moreover, in the second example, the Cox model exhibits a significant effect that the linear model does not. We provide methods to select the best-fitting models for repeated duration data and to compare statistical methodologies. In this study, we show that Cox models are best suited to the analysis of our data set.

The Role of Feedback and Differences between Good and Poor Decoders in a Repeated Word Reading Paradigm in First Grade

ERIC Educational Resources Information Center

van Gorp, Karly; Segers, Eliane; Verhoeven, Ludo

2017-01-01

The direct, retention, and transfer effects of repeated word and pseudoword reading were studied in a pretest, training, posttest, retention design. First graders (48 good readers, 47 poor readers) read 25 CVC words and 25 CVC pseudowords in ten repeated word reading sessions, preceded and followed by a transfer task with a different set of items.…

Aspergillus niger PA2 Tyrosinase Covalently Immobilized on a Novel Eco-Friendly Bio-Composite of Chitosan-Gelatin and Its Evaluation for L-DOPA Production

PubMed Central

Agarwal, Pragati; Dubey, Swati; Singh, Mukta; Singh, Rajesh P.

2016-01-01

Tyrosinase (EC 1.14.18.1) a copper-containing monooxygenase, isolated from a fungal isolate Aspergillus niger PA2 was subjected for immobilization onto a composite consisting of chitosan and gelatin biopolymers. The homogeneity of the chitosan-gelatin biocomposite film was characterized by X-ray diffraction analyses. To evaluate immobilization efficiency, chitosan-gelatin-Tyr bio-composite films were analyzed by field emission scanning electron microscopy, atomic force microscopy and UV-spectroscopy. The rough morphology of the film led to a high loading of enzyme and it could retain its bioactivity for a longer period. The enzyme adsorbed onto the film exhibited 72% of its activity after 10 days and exhibited good repeatability for up to nine times, after intermittent storage. Moreover, the immobilized enzyme exhibited broader pH and temperature profile as compared to free counterpart. Immobilized enzyme was further evaluated for the synthesis of L-DOPA (2,4-dihydroxy phenylalanine) which is a precursor of dopamine and a potent drug for the treatment of Parkinson's disease and for myocardium neurogenic injury. PMID:28066399

A Thin Film Flexible Supercapacitor Based on Oblique Angle Deposited Ni/NiO Nanowire Arrays.

PubMed

Ma, Jing; Liu, Wen; Zhang, Shuyuan; Ma, Zhe; Song, Peishuai; Yang, Fuhua; Wang, Xiaodong

2018-06-11

With high power density, fast charging-discharging speed, and a long cycling life, supercapacitors are a kind of highly developed novel energy-storage device that has shown a growing performance and various unconventional shapes such as flexible, linear-type, stretchable, self-healing, etc. Here, we proposed a rational design of thin film, flexible micro-supercapacitors with in-plane interdigital electrodes, where the electrodes were fabricated using the oblique angle deposition technique to grow oblique Ni/NiO nanowire arrays directly on polyimide film. The obtained electrodes have a high specific surface area and good adhesion to the substrate compared with other in-plane micro-supercapacitors. Meanwhile, the as-fabricated micro-supercapacitors have good flexibility and satisfactory energy-storage performance, exhibiting a high specific capacity of 37.1 F/cm³, a high energy density of 5.14 mWh/cm³, a power density of up to 0.5 W/cm³, and good stability during charge-discharge cycles and repeated bending-recovery cycles, respectively. Our micro-supercapacitors can be used as ingenious energy storage devices for future portable and wearable electronic applications.

Fast response of carbon monoxide gas sensors using a highly porous network of ZnO nanoparticles decorated on 3D reduced graphene oxide

NASA Astrophysics Data System (ADS)

Ha, Nguyen Hai; Thinh, Dao Duc; Huong, Nguyen Thanh; Phuong, Nguyen Huy; Thach, Phan Duy; Hong, Hoang Si

2018-03-01

Zinc oxide (ZnO) nanoparticles loaded onto 3D reduced graphene oxide (3D-RGO) for carbon monoxide (CO) sensing were synthesized using hydrothermal method. The highly porous ZnO/3D-RGO configuration was stable without collapsing and was deposited on the micro-heater of the CO gas sensor. The resulting CO gas sensor displayed high sensitivity, fast response/recovery, and good linearity. The sensor achieved a response value of 85.2% for 1000 ppm CO at a working temperature of 200 °C. The response and recovery times of the sensor were 7 and 9 s for 1000 ppm CO at 200 °C. Similarly, the response value, response time, and recovery time of the sensor at room temperature were 27.5%, 14 s, and 15 s, respectively. The sensor demonstrated a distinct response to various CO concentrations in the range of 1-1000 ppm and good selectivity toward CO gas. In addition, the sensor exhibited good repeatability in multi-cycle and long-term stability.

Brain pathology after mild traumatic brain injury: an exploratory study by repeated magnetic resonance examination.

PubMed

Lannsjö, Marianne; Raininko, Raili; Bustamante, Mariana; von Seth, Charlotta; Borg, Jörgen

2013-09-01

To explore brain pathology after mild traumatic brain injury by repeated magnetic resonance examination. A prospective follow-up study. Nineteen patients with mild traumatic brain injury presenting with Glasgow Coma Scale (GCS) 14-15. The patients were examined on day 2 or 3 and 3-7 months after the injury. The magnetic resonance protocol comprised conventional T1- and T2-weighted sequences including fluid attenuated inversion recovery (FLAIR), two susceptibility-weighted sequences to reveal haemorrhages, and diffusion-weighted sequences. Computer-aided volume comparison was performed. Clinical outcome was assessed by the Rivermead Post-Concussion Symptoms Questionnaire (RPQ), Hospital Anxiety and Depression Scale (HADS) and Glasgow Outcome Scale Extended (GOSE). At follow-up, 7 patients (37%) reported ≥  3 symptoms in RPQ, 5 reported some anxiety and 1 reported mild depression. Fifteen patients reported upper level of good recovery and 4 patients lower level of good recovery (GOSE 8 and 7, respectively). Magnetic resonance pathology was found in 1 patient at the first examination, but 4 patients (21%) showed volume loss at the second examination, at which 3 of them reported < 3 symptoms and 1 ≥ 3 symptoms, all exhibiting GOSE scores of 8. Loss of brain volume, demonstrated by computer-aided magnetic resonance imaging volumetry, may be a feasible marker of brain pathology after mild traumatic brain injury.

A carbon nanotube based ammonia sensor on cotton textile

NASA Astrophysics Data System (ADS)

Han, Jin-Woo; Kim, Beomseok; Li, Jing; Meyyappan, M.

2013-05-01

A single-wall carbon nanotube (CNT) based ammonia (NH3) sensor was implemented on a cotton yarn. Two types of sensors were fabricated: Au/sensing CNT/Au and conducting/sensing/conducting all CNT structures. Two perpendicular Au wires were designed to contact CNT-cotton yarn for metal-CNT sensor, whereas nanotubes were used for the electrode as well as sensing material for the all CNT sensor. The resistance shift of the CNT network upon NH3 was monitored in a chemiresistor approach. The CNT-cotton yarn sensors exhibited uniformity and repeatability. Furthermore, the sensors displayed good mechanical robustness against bending. The present approach can be utilized for low-cost smart textile applications.

The evolution of filamin – A protein domain repeat perspective

PubMed Central

Light, Sara; Sagit, Rauan; Ithychanda, Sujay S.; Qin, Jun; Elofsson, Arne

2013-01-01

Particularly in higher eukaryotes, some protein domains are found in tandem repeats, performing broad functions often related to cellular organization. For instance, the eukaryotic protein filamin interacts with many proteins and is crucial for the cytoskeleton. The functional properties of long repeat domains are governed by the specific properties of each individual domain as well as by the repeat copy number. To provide better understanding of the evolutionary and functional history of repeating domains, we investigated the mode of evolution of the filamin domain in some detail. Among the domains that are common in long repeat proteins, sushi and spectrin domains evolve primarily through cassette tandem duplications while scavenger and immunoglobulin repeats appear to evolve through clustered tandem duplications. Additionally, immunoglobulin and filamin repeats exhibit a unique pattern where every other domain shows high sequence similarity. This pattern may be the result of tandem duplications, serve to avert aggregation between adjacent domains or it is the result of functional constraints. In filamin, our studies confirm the presence of interspersed integrin binding domains in vertebrates, while invertebrates exhibit more varied patterns, including more clustered integrin binding domains. The most notable case is leech filamin, which contains a 20 repeat expansion and exhibits unique dimerization topology. Clearly, invertebrate filamins are varied and contain examples of similar adjacent integrin-binding domains. Given that invertebrate integrin shows more similarity to the weaker filamin binder, integrin β3, it is possible that the distance between integrin-binding domains is not as crucial for invertebrate filamins as for vertebrates. PMID:22414427

The evolution of filamin-a protein domain repeat perspective.

PubMed

Light, Sara; Sagit, Rauan; Ithychanda, Sujay S; Qin, Jun; Elofsson, Arne

2012-09-01

Particularly in higher eukaryotes, some protein domains are found in tandem repeats, performing broad functions often related to cellular organization. For instance, the eukaryotic protein filamin interacts with many proteins and is crucial for the cytoskeleton. The functional properties of long repeat domains are governed by the specific properties of each individual domain as well as by the repeat copy number. To provide better understanding of the evolutionary and functional history of repeating domains, we investigated the mode of evolution of the filamin domain in some detail. Among the domains that are common in long repeat proteins, sushi and spectrin domains evolve primarily through cassette tandem duplications while scavenger and immunoglobulin repeats appear to evolve through clustered tandem duplications. Additionally, immunoglobulin and filamin repeats exhibit a unique pattern where every other domain shows high sequence similarity. This pattern may be the result of tandem duplications, serve to avert aggregation between adjacent domains or it is the result of functional constraints. In filamin, our studies confirm the presence of interspersed integrin binding domains in vertebrates, while invertebrates exhibit more varied patterns, including more clustered integrin binding domains. The most notable case is leech filamin, which contains a 20 repeat expansion and exhibits unique dimerization topology. Clearly, invertebrate filamins are varied and contain examples of similar adjacent integrin-binding domains. Given that invertebrate integrin shows more similarity to the weaker filamin binder, integrin β3, it is possible that the distance between integrin-binding domains is not as crucial for invertebrate filamins as for vertebrates. Copyright © 2012 Elsevier Inc. All rights reserved.

Identifying individual male reproductive consistency in Drosophila melanogaster: The importance of controlling female behaviour.

PubMed

Balaban-Feld, Jesse; Valone, Thomas J

2017-09-01

Work on the repeatability of reproductive behaviour has mainly focused on the consistency of female preferences. We characterised the consistency of individual male Drosophila melanogaster reproductive behaviour in two experiments. In the first experiment, we allowed males to interact with a pair of live females that differed in body size. We then controlled female behaviour in a second experiment by examining the courtship behaviour of individual males interacting with a pair of decapitated females that varied in body size. In both experiments, we examined the consistency of individual male reproductive behaviour across two repeated trials on the same day. Males did not exhibit a courtship preference for the larger female in either experiment, but, in experiment 1, males did exhibit post-copulatory choice by copulating for longer durations with the large female, and males that mated with the same type of female in both trials exhibited repeatable behaviour. In general, we found weak evidence of consistent male courtship behaviour in the presence of behaving females. However, when female behaviour was controlled in experiment 2, we found that male courtship behaviour was highly repeatable. These results indicate that individual male D. melanogaster exhibit consistent reproductive behaviour and demonstrate the importance of controlling female behaviour when attempting to characterise the repeatability of male reproductive behaviour. Copyright © 2017 Elsevier B.V. All rights reserved.

Genetic instability caused by loss of MutS homolog 3 in human colorectal cancer

PubMed Central

Haugen, Astrid C.; Goel, Ajay; Yamada, Kanae; Marra, Giancarlo; Nguyen, Thuy-Phuong; Nagasaka, Takeshi; Kanazawa, Shinsaku; Koike, Junichi; Kikuchi, Yoshinori; Zhong, Xiaoling; Arita, Michitsune; Shibuya, Kazutoshi; Oshimura, Mitsuo; Hemmi, Hiromichi; Boland, Clement Richard; Koi, Minoru

2008-01-01

Microsatellite instability (MSI) is a hallmark of mismatch repair deficiency. High levels of MSI at mono- and dinucleotide repeats in colorectal cancer (CRC) are attributed to inactivation of the mismatch repair genes, hMLH1 and hMSH2. CRC with low levels of MSI (MSI-L) exists; however its molecular basis is unclear. There is another type of MSI - “elevated microsatellite alterations at selected tetranucleotide repeats” - (EMAST) where loci containing [AAAG]n or [ATAG]n repeats are unstable. EMAST is frequent in non-colorectal cancers; however the incidence of EMAST and its cause in CRC is not known. Here, we report that MSH3-knock-down or MSH3-deficient cells exhibit the EMAST phenotype and low levels of mutations at dinucleotide repeats. About 60% of 117 sporadic CRC cases exhibit EMAST. All of the cases defined as MSI-H (16 cases) exhibited high levels of EMAST. Among 101 non-MSI-H cases, all 19 cases of MSI-L and 35 of 82 cases of MSS exhibited EMAST. Although non-MSI-H CRC tissues contained MSH3-negative tumor cells ranging from 2-50% of the total tumor cell population, the tissues exhibiting EMAST contained more MSH3-negative cells (average 31.5%) than did the tissues not exhibiting EMAST (8.4%). Taken together, our results support the idea that MSH3-deficiency causes EMAST or EMAST with low levels of MSI at the loci with dinucleotide repeats in CRC. PMID:18922920

Trachomatous Scar Ranking: A Novel Outcome for Trachoma Studies.

PubMed

Baldwin, Angela; Ryner, Alexander M; Tadesse, Zerihun; Shiferaw, Ayalew; Callahan, Kelly; Fry, Dionna M; Zhou, Zhaoxia; Lietman, Thomas M; Keenan, Jeremy D

2017-06-01

AbstractWe evaluated a new trachoma scarring ranking system with potential use in clinical research. The upper right tarsal conjunctivas of 427 individuals from Ethiopian villages with hyperendemic trachoma were photographed. An expert grader first assigned a scar grade to each photograph using the 1981 World Health Organization (WHO) grading system. Then, all photographs were ranked from least (rank = 1) to most scarring (rank = 427). Photographic grading found 79 (18.5%) conjunctivae without scarring (C0), 191 (44.7%) with minimal scarring (C1), 105 (24.6%) with moderate scarring (C2), and 52 (12.2%) with severe scarring (C3). The ranking method demonstrated good internal validity, exhibiting a monotonic increase in the median rank across the levels of the 1981 WHO grading system. Intrarater repeatability was better for the ranking method (intraclass correlation coefficient = 0.84, 95% CI = 0.74-0.94). Exhibiting better internal and external validity, this ranking method may be useful for evaluating the difference in scarring between groups of individuals.

Surface plasmon resonance sensor for antibiotics detection based on photo-initiated polymerization molecularly imprinted array.

PubMed

Luo, Qiaohui; Yu, Neng; Shi, Chunfei; Wang, Xiaoping; Wu, Jianmin

2016-12-01

A surface plasmon resonance (SPR) sensor combined with nanoscale molecularly imprinted polymer (MIP) film as recognition element was developed for selective detection of the antibiotic ciprofloxacin (CIP). The MIP film on SPR sensor chip was prepared by in situ photo-initiated polymerization method which has the advantages of short polymerization time, controllable thickness and good uniformity. The surface wettability and thickness of MIP film on SPR sensor chip were characterized by static contact angle measurement and stylus profiler. The MIP-SPR sensor exhibited high selectivity, sensitivity and good stability for ciprofloxacin. The imprinting factors of the MIP-SPR sensor to ciprofloxacin and its structural analogue ofloxacin were 2.63 and 3.80, which is much higher than those to azithromycin, dopamine and penicillin. The SPR response had good linear relation with CIP concentration over the range 10 -11 -10 -7 molL -1 . The MIP-SPR sensor also showed good repeatability and stability during cyclic detections. On the basis of the photo-initiated polymerization method, a surface plasmon resonance imaging (SPRi) chip modified with three types of MIP sensing spots was fabricated. The MIPs-SPRi sensor shows different response patterns to ciprofloxacin and azithromycin, revealing the ability to recognize different antibiotic molecules. Copyright © 2016 Elsevier B.V. All rights reserved.

Repeatability study of replicate crash tests: A signal analysis approach.

PubMed

Seppi, Jeremy; Toczyski, Jacek; Crandall, Jeff R; Kerrigan, Jason

2017-10-03

To provide an objective basis on which to evaluate the repeatability of vehicle crash test methods, a recently developed signal analysis method was used to evaluate correlation of sensor time history data between replicate vehicle crash tests. The goal of this study was to evaluate the repeatability of rollover crash tests performed with the Dynamic Rollover Test System (DRoTS) relative to other vehicle crash test methods. Test data from DRoTS tests, deceleration rollover sled (DRS) tests, frontal crash tests, frontal offset crash tests, small overlap crash tests, small overlap impact (SOI) crash tests, and oblique crash tests were obtained from the literature and publicly available databases (the NHTSA vehicle database and the Insurance Institute for Highway Safety TechData) to examine crash test repeatability. Signal analysis of the DRoTS tests showed that force and deformation time histories had good to excellent repeatability, whereas vehicle kinematics showed only fair repeatability due to the vehicle mounting method for one pair of tests and slightly dissimilar mass properties (2.2%) in a second pair of tests. Relative to the DRS, the DRoTS tests showed very similar or higher levels of repeatability in nearly all vehicle kinematic data signals with the exception of global X' (road direction of travel) velocity and displacement due to the functionality of the DRoTS fixture. Based on the average overall scoring metric of the dominant acceleration, DRoTS was found to be as repeatable as all other crash tests analyzed. Vertical force measures showed good repeatability and were on par with frontal crash barrier forces. Dynamic deformation measures showed good to excellent repeatability as opposed to poor repeatability seen in SOI and oblique deformation measures. Using the signal analysis method as outlined in this article, the DRoTS was shown to have the same or better repeatability of crash test methods used in government regulatory and consumer evaluation test protocols.

FRB 121102: A Starquake-induced Repeater?

NASA Astrophysics Data System (ADS)

Wang, Weiyang; Luo, Rui; Yue, Han; Chen, Xuelei; Lee, Kejia; Xu, Renxin

2018-01-01

Since its initial discovery, the fast radio burst (FRB) FRB 121102 has been found to be repeating with millisecond-duration pulses. Very recently, 14 new bursts were detected by the Green Bank Telescope during its continuous monitoring observations. In this paper, we show that the burst energy distribution has a power-law form which is very similar to the Gutenberg–Richter law of earthquakes. In addition, the distribution of burst waiting time can be described as a Poissonian or Gaussian distribution, which is consistent with earthquakes, while the aftershock sequence exhibits some local correlations. These findings suggest that the repeating FRB pulses may originate from the starquakes of a pulsar. Noting that the soft gamma-ray repeaters (SGRs) also exhibit such distributions, the FRB could be powered by some starquake mechanisms associated with the SGRs, including the crustal activity of a magnetar or solidification-induced stress of a newborn strangeon star. These conjectures could be tested with more repeating samples.

Development of a pH sensing membrane electrode based on a new calix[4]arene derivative.

PubMed

Kormalı Ertürün, H Elif; Demirel Özel, Ayça; Sayın, Serkan; Yılmaz, Mustafa; Kılıç, Esma

2015-01-01

A new pH sensing poly(vinyl chloride) (PVC) membrane electrode was developed by using recently synthesized 5,17-bis(4-benzylpiperidine-1-yl)methyl-25,26,27,28-tetrahydroxy calix[4]arene as an ionophore. The effects of membrane composition, inner filling solution and conditioning solution on the potential response of the proposed pH sensing membrane electrode were investigated. An optimum membrane composition of 3% ionophore, 67% o-nitrophenyl octyl ether (o-NPOE) as plasticizer, 30% PVC was found. The electrode exhibited a near-Nernstian slope of 58.7±1.1 mV pH(-1) in the pH range 1.9-12.7 at 20±1 °C. It showed good selectivity for H(+) ions in the presence of some cations and anions and a longer lifetime of at least 12 months when compared with the other PVC membrane pH electrodes reported in the literature. Having a wide working pH range, it was not only applied as a potentiometric indicator electrode in various acid-base titrations, but also successfully employed in different real samples. It has good reproducibility and repeatability with a response time of 6-7s. Compared to traditional glass pH electrode, it exhibited excellent potentiometric response after being used in fluoride-containing media. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparative analysis of tandem repeats from hundreds of species reveals unique insights into centromere evolution

USDA-ARS?s Scientific Manuscript database

Centromeres are essential for chromosome segregation, yet their DNA sequences evolve rapidly. In most animals and plants that have been studied, centromeres comprise of megabase-scale arrays of tandem repeats. The true prevalence of centromere tandem repeats, and whether they exhibit conserved seque...

Test--retest variability of Randot stereoacuity measures gathered in an unselected sample of UK primary school children.

PubMed

Adler, Paul; Scally, Andrew J; Barrett, Brendan T

2012-05-01

To determine the test-retest reliability of the Randot stereoacuity test when used as part of vision screening in schools. Randot stereoacuity (graded-circles) and logMAR visual acuity measures were gathered in an unselected sample of 139 children (aged 4-12, mean 8.1±2.1 years) in two schools. Randot testing was repeated on two occasions (average interval between successive tests 8 days, range: 1-21 days). Three Randot scores were obtained in 97.8% of children. Randot stereoacuity improved by an average of one plate (ie, one test level) on repeat testing but was little changed when tested on the third occasion. Within-subject variability was up to three test levels on repeat testing. When stereoacuity was categorised as 'fine', 'intermediate' or 'coarse', the greatest variability was found among younger children who exhibited 'intermediate' or 'coarse'/nil stereopsis on initial testing. Whereas 90.8% of children with 'fine' stereopsis (≤50 arc-seconds) on the first test exhibited 'fine' stereopsis on both subsequent tests, only ∼16% of children with 'intermediate' (>50 but ≤140 arc-seconds) or 'coarse'/nil (≥200 arc-seconds) stereoacuity on initial testing exhibited stable test results on repeat testing. Children exhibiting abnormal stereoacuity on initial testing are very likely to exhibit a normal result when retested. The value of a single, abnormal Randot graded-circles stereoacuity measure from school screening is therefore questionable.

[Clinical outcomes and economic analysis of two ovulation induction protocols in patients undergoing repeated IVF/ICSI cycles].

PubMed

Chen, Xiao; Geng, Ling; Li, Hong

2014-04-01

To compare the clinical outcomes and cost-effectiveness of luteal phase down-regulation with gonadotrophin-releasing hormone (GnRH) agonist protocol and GnRH antagonist protocol in patients undergoing repeated in vitro fertilization and intracytoplasmic sperm injection (IVF-ICSI) cycles. A retrospective analysis of clinical outcomes and costs was conducted among 198 patients undergoing repeated IVF-ICSI cycles, including 109 receiving luteal phase down-regulation with GnRH agonist protocol (group A) and 89 receiving GnRH antagonist protocol (group B). The numbers of oocytes retrieved and good embryos, clinical pregnancy rate, abortion rate, the live birth rate, mean total cost, and the cost-effective ratio were compared between the two groups. In patients undergoing repeated IVF-ICSI cycles, the two protocols produced no significant differences in the number of good embryos, clinical pregnancy rate, abortion rate, or twin pregnancy rate. Compared with group B, group A had better clinical outcomes though this difference was not statistically significant. The number of retrieved oocytes was significantly greater and live birth rate significantly higher in group A than in group B (9.13=4.98 vs 7.11=4.74, and 20.2% vs 9.0%, respectively). Compared with group B, group A had higher mean total cost per cycle but lower costs for each oocyte retrieved (2729.11 vs 3038.60 RMB yuan), each good embryo (8867.19 vs 9644.85 RMB yuan), each clinical pregnancy (77598.06 vs 96139.85 RMB yuan). For patients undergoing repeated IVF/ICSI cycle, luteal phase down-regulation with GnRH agonist protocol produces good clinical outcomes with also good cost-effectiveness in spite an unsatisfactory ovarian reserve.

Repeated Prescribed Burning in Aspen

Treesearch

Donald A. Perala

1974-01-01

Infrequent burning weather, low flammability of the aspen-hardwood association, and prolific sprouting and seeding of shrubs and hardwoods made repeated dormant season burning a poor tool to convert good site aspen to conifers. Repeat fall burns for wildlife habitat maintenance is workable if species composition changes are not important.

Sequence heuristics to encode phase behaviour in intrinsically disordered protein polymers

PubMed Central

Quiroz, Felipe García; Chilkoti, Ashutosh

2015-01-01

Proteins and synthetic polymers that undergo aqueous phase transitions mediate self-assembly in nature and in man-made material systems. Yet little is known about how the phase behaviour of a protein is encoded in its amino acid sequence. Here, by synthesizing intrinsically disordered, repeat proteins to test motifs that we hypothesized would encode phase behaviour, we show that the proteins can be designed to exhibit tunable lower or upper critical solution temperature (LCST and UCST, respectively) transitions in physiological solutions. We also show that mutation of key residues at the repeat level abolishes phase behaviour or encodes an orthogonal transition. Furthermore, we provide heuristics to identify, at the proteome level, proteins that might exhibit phase behaviour and to design novel protein polymers consisting of biologically active peptide repeats that exhibit LCST or UCST transitions. These findings set the foundation for the prediction and encoding of phase behaviour at the sequence level. PMID:26390327

Substituted polyacetylene separation membrane

DOEpatents

Pinnau, Ingo; Morisato, Atsushi

1998-01-13

A separation membrane useful for gas separation, particularly separation of C.sub.2+ hydrocarbons from natural gas. The invention encompasses the membrane itself, methods of making it and processes for using it. The membrane comprises a polymer having repeating units of a hydrocarbon-based, disubstituted polyacetylene, having the general formula: ##STR1## wherein R.sub.1 is chosen from the group consisting of C.sub.1 -C.sub.4 alkyl and phenyl, and wherein R.sub.2 is chosen from the group consisting of hydrogen and phenyl. In the most preferred embodiment, the membrane comprises poly(4-methyl-2-pentyne) ›PMP!. The membrane exhibits good chemical resistance and has super-glassy properties with regard to separating certain large, condensable permeant species from smaller, less-condensable permeant species. The membranes may also be useful in other fluid separations.

Photoresponse in La0.9Hf0.1MnO3/0.05wt%Nb-doped SrTiO3 heteroepitaxial junctions

NASA Astrophysics Data System (ADS)

Qi, Yaping; Ni, Hao; Zheng, Ming; Zeng, Jiali; Jiang, Yucheng; Gao, Ju

2018-05-01

Excellent photo detectors need to have the rapid response and good repeatability from the requirement of industrial applications. In this paper, transport behavior and opto-response of heterostructures made with La0.9Hf0.1MnO3 and 0.05wt%Nb-doped SrTiO3 were investigated. The heterojunctions exhibited an excellent rectifying feature with very low leakage in a broad temperature region (from 40 to 300 K). These thin films presented persistent and stable photovoltages upon light illumination. Rapid shift between small and large voltages corresponding to "light OFF" and "light ON" states, respectively, was observed, demonstrating reliable photo detection behavior. A semiconductor laser with a wavelength of 650 nm was used as the light source. It is also noted that the observed photovoltages are strongly determined by light intensity. The injection of photoexcited charge carriers (electrons) could be responsible for the appearance of the observed opto-response. Such manipulative features by light irradiation exhibit great potential for light detectors for visible light.

Flexible strain sensors with high performance based on metallic glass thin film

NASA Astrophysics Data System (ADS)

Xian, H. J.; Cao, C. R.; Shi, J. A.; Zhu, X. S.; Hu, Y. C.; Huang, Y. F.; Meng, S.; Gu, L.; Liu, Y. H.; Bai, H. Y.; Wang, W. H.

2017-09-01

Searching strain sensitive materials for electronic skin is of crucial significance because of the restrictions of current materials such as poor electrical conductivity, large energy consumption, complex manufacturing process, and high cost. Here, we report a flexible strain sensor based on the Zr55Cu30Ni5Al10 metallic glass thin film which we name metallic glass skin. The metallic glass skin, synthesized by ion beam deposition, exhibits piezoresistance effects with a gauge factor of around 2.86, a large detectable strain range (˜1% or 180° bending angle), and good conductivity. Compared to other e-skin materials, the temperature coefficient of resistance of the metallic glass skin is extremely low (9.04 × 10-6 K-1), which is essential for the reduction in thermal drift. In addition, the metallic glass skin exhibits distinct antibacterial behavior desired for medical applications, also excellent reproducibility and repeatability (over 1000 times), nearly perfect linearity, low manufacturing cost, and negligible energy consumption, all of which are required for electronic skin for practical applications.

Graphene-ZIF8 composite material as stationary phase for high-resolution gas chromatographic separations of aliphatic and aromatic isomers.

PubMed

Yang, Xiaohong; Li, Changxia; Qi, Meiling; Qu, Liangti

2016-08-19

This work presents the separation performance of graphene-ZIF8 (G-Z) composite material as stationary phase for capillary gas chromatography (GC). The G-Z stationary phase achieved high column efficiency of 5000 plates/m determined by n-dodecane (k=1.22) at 120°C and showed weakly polar nature. Importantly, it exhibited high selectivity and resolving capability for branched alkane isomers and aromatic positional isomers, showing clear advantages over the reported neat graphene and ZIF8. In addition, it attained high resolution for geometric cis-/trans-isomers. The G-Z column exhibited good column thermal stability up to 300°C and column repeatability with RSD values of retention times in the range of 0.01-0.19% for intra-day, 0.05-0.88% for inter-day and 0.66-5.6% for between-column, respectively, Moreover, the G-Z column was employed for the determination of minor impurity isomers in real reagent samples, which demonstrates its promising potential in GC applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Combination of QuEChERS and DLLME for GC-MS determination of pesticide residues in orange samples.

PubMed

Andraščíková, Mária; Hrouzková, Svetlana; Cunha, Sara C

2013-01-01

A new method combining QuEChERS (quick, easy, cheap, effective, rugged and safe) and DLLME (dispersive liquid-liquid microextraction) followed by gas chromatography-mass spectrometry with selected ion monitoring (SIM) was developed for the simultaneous determination of 19 pesticides from nine chemical groups exhibiting or suspected to exhibit endocrine-disrupting properties in orange samples. Acetonitrile extract obtained from QuEChERS extraction was used for DLLME as dispersive solvent and carbon tetrachloride as extractive solvent to increase the enrichment factor of the extraction procedure. The effect of several extraction parameters, such as volume extract achieved by the QuEChERS method and subsequently used for DLLME, selection of extractive solvent and its volume, was tested. Under optimum conditions, good linearity, satisfactory recoveries and repeatability were obtained. Limits of quantification (LOQs) achieved (ranging from 0.02 to 47 ng/g) were below the maximum residue limits established by the European Union. The proposed method was applied to the monitoring of pesticide residue levels in oranges commercialised in Portugal.

Solution for testing large high-power laser lenses having long focal length (Conference Presentation)

NASA Astrophysics Data System (ADS)

Fappani, Denis; IDE, Monique

2017-05-01

Many high power laser facilities are in operation all around the world and include various tight optical components such as large focussing lenses. Such lenses exhibit generally long focal lengths which induces some issues for their optical testing during manufacturing and inspection. Indeed, their transmitted wave fronts need to be very accurate and interferometric testing is the baseline to achieve that. But, it is always a problem to manage simultaneously long testing distances and fine accuracies in such interferometry testing. Taking example of the large focusing lenses produced for the Orion experimentation at AWE (UK), the presentation will describe which kind of testing method has been developed to demonstrate simultaneously good performances with sufficiently good repeatability and absolute accuracy. Special emphasis will be made onto the optical manufacturing issues and interferometric testing solutions. Some ZEMAX results presenting the test set-up and the calibration method will be presented as well. The presentation will conclude with a brief overview of the existing "state of the art" at Thales SESO for these technologies.

π-Extended triptycene-based material for capillary gas chromatographic separations.

PubMed

Yang, Yinhui; Wang, Qinsi; Qi, Meiling; Huang, Xuebin

2017-10-02

Triptycene-based materials feature favorable physicochemical properties and unique molecular recognition ability that offer good potential as stationary phases for capillary gas chromatography (GC). Herein, we report the investigation of utilizing a π-extended triptycene material (denoted as TQPP) for GC separations. As a result, the TQPP capillary column exhibited high column efficiency of 4030 plates m -1 and high-resolution performance for a wide range of analytes, especially structural and positional isomers. Interestingly, the TQPP stationary phase showed unique shape selectivity for alkanes isomers and preferential retention for analytes with halogen atoms and H-bonding nature mainly through their halogen-bonding and H-bonding interactions. In addition, the TQPP column had good repeatability and reproducibility with the RSD values of 0.02-0.34% for run-to-run, 0.09-0.80% for day-to-day and 1.4-5.2% for column-to-column, respectively, and favorable thermal stability up to 280 °C. This work demonstrates the promising future of triptycene-based materials as a new class of stationary phases for GC separations. Copyright © 2017 Elsevier B.V. All rights reserved.

Semiconducting and quartz microbalance (QCM) humidity sensor properties of TiO2 by sol gel calcination method

NASA Astrophysics Data System (ADS)

Yakuphanoglu, Fahrettin

2012-06-01

Titanium dioxide (TiO2) material was synthesized using the sol gel calcination method. The structural properties of the TiO2 semiconductor were investigated by atomic force microscopy. The electrical conductivity of the TiO2 was measured as a function of temperature and TiO2 exhibits a conductivity of 2.55 × 10-6 S/m at room temperature with activation energy of 104 meV. The electrical conductivity of the TiO2 at room temperature is higher than that of nanocrystalline TiO2 (3 × 10-7 S/m) and TiO2 thin film in air (5 × 10-9 S/m) and in vacuum (8.8 × 10-10 S/m). It was found that the electrical transport mechanism of the TiO2 is controlled by thermally activated mechanism. The optical band gap of the TiO2 powder sample was determined to be 3.17 eV, which is good in agreement with the bulk TiO2 (Eg = 3.2 eV). Up to our knowledge, there is no any reported data about the band gap of TiO2 nanopowder based on the diffused reflectance calculation. Quartz crystal microbalance (QCM) TiO2 humidity sensor was prepared. The sensor indicates a large frequency change with an interaction occurred between TiO2 and humidity molecules. The sensor exhibits a good repeatability when it was exposed to the moist air of 65% RH.

Magnetic covalent triazine-based frameworks as magnetic solid-phase extraction adsorbents for sensitive determination of perfluorinated compounds in environmental water samples.

PubMed

Ren, Ji-Yun; Wang, Xiao-Li; Li, Xiao-Li; Wang, Ming-Lin; Zhao, Ru-Song; Lin, Jin-Ming

2018-02-01

Covalent organic frameworks (COFs), which are a new type of carbonaceous polymeric material, have attracted great interest because of their large surface area and high chemical and thermal stability. However, to the best of our knowledge, no work has reported the use of magnetic COFs as adsorbents for magnetic solid-phase extraction (MSPE) to enrich and determine environmental pollutants. This work aims to investigate the feasibility of using covalent triazine-based framework (CTF)/Fe 2 O 3 composites as MSPE adsorbents to enrich and analyze perfluorinated compounds (PFCs) at trace levels in water samples. Under the optimal conditions, the method developed exhibited low limits of detection (0.62-1.39 ng·L -1 ), a wide linear range (5-4000 ng L -1 ), good repeatability (1.12-9.71%), and good reproducibility (2.45-7.74%). The new method was successfully used to determine PFCs in actual environmental water samples. MSPE based on CTF/Fe 2 O 3 composites exhibits potential for analysis of PFCs at trace levels in environmental water samples. Graphical abstract Magnetic covalent triazine-based frameworks (CTFs) were used as magnetic solid-phase extraction adsorbents for the sensitive determination of perfluorinated compounds in environmental water samples. PFBA perfluorobutyric acid, PFBS perfluorobutane sulfonate, PFDA perfluorodecanoic acid, PFDoA perfluorododecanoic acid, PFHpA perfluoroheptanoic acid, PFHxA perfluorohexanoic acid, PFHxS perfluorohexane sulfonate, PFNA perfluorononanoic acid, PFOA perfluorooctanoic acid, PFPeA perfluoropentanoic acid, PFUdA Perfluoroundecanoic acid.

Adaptive play stabilizes cooperation in continuous public goods games

NASA Astrophysics Data System (ADS)

Wu, Te; Wang, Long

2018-04-01

We construct a model to study the effects of repeated interaction on the evolution of cooperation in continuous public goods games. Instead of preassigning the duration of repeatedness, the likelihood of group entering next round interaction is positively dependent on the group's current cooperativeness. Meanwhile, when the disturbance happens, the interaction terminates. Under rare mutations, we show that such adaptive play can lead to the dominance of full cooperative state for weak disturbance. For fairly strong disturbance, all-or-none cooperative states share higher fractions of time in the long run, results similar to the ones reported in the study (Pinheiro et al., 2014) while differing from the ones reported in another relevant study (Van Segbroeck et al., 2012), although only strategy space and way determining next round vary. Our results remain valid when groups enter next round with a given probability independent of groups' cooperativeness. In the synergic public goods games, the positive effects of repeated interactions on promoting cooperation is further strengthened. In the discounted public goods game, only very weak disturbance can lead to the dominance of full cooperative state while fairly strong disturbance can favor both full cooperative state and a partially cooperative state. Our study thus enriches the literature on the evolution of cooperation in repeated public goods games.

[Determination of heavy metals for RoHS compliance by ICP-OES spectrometry coupled with microwave extraction system].

PubMed

Hua, Li; Wu, Yi-Ping; An, Bing; Lai, Xiao-Wei

2008-11-01

The harm of heavy metals contained in electronic and electrical equipment (EEE) on environment is of high concern by human. Aiming to handle the great challenge of RoHS compliance, the determinations of trace or ultratrace chromium (Cr), cadmium (Cd), mercury (Hg) and lead (Pb) by inductively coupled plasma optical emission spectrometry (ICP-OES) was performed in the present paper, wherein, microwave extraction technology was used to prepare the sample solutions. In addition, the precision, recovery, repeatability and interference issues of this method were also discussed. The results exhibited that using the microwave extraction system to prepare samples is more quick, lossless, contamination-free in comparison with the conventional extraction methods such as dry ashing, wet-oven extraction etc. By analyzing the recoveries of these four heavy metals over different working time and wavelengths, the good recovery range between 85% and 115% showed that there was only tiny loss or contamination during the process of microwave extraction, sample introduction and ICP detection. Repeatability experiments proved that ICP plasma had a good stability during the working time and the matrix effect was small. Interference was a problem troublesome for atomic absorption spectrometry (AAS), however, the techniques of standard additions or inter-element correction (IEC) method can effectively eliminated the interferences of Ni, As, Fe etc. with the Cd determination. By employing the multi-wavelengths and two correction point methods, the issues of background curve sloping shift and spectra overlap were successfully overcome. Besides, for the determinations of trace heavy metal elements, the relative standard deviation (RSD) was less than 3% and the detection limits were less than 1 microg x L(-10 (3sigma, n = 5) for samples, standard solutions, and standard additions, which proved that ICP-OES has a good precision and high reliability. This provided a reliable technique support for electronic and electrical (EE) industries to comply with RoHS directive.

Psychometric Properties of Translation of the Child Perception Questionnaire (CPQ11-14) in Telugu Speaking Indian Children.

PubMed

Kumar, Santhosh; Kroon, Jeroen; Lalloo, Ratilal; Johnson, Newell W

2016-01-01

Oral health related quality of life research among children in India is still nascent and no measures have been validated to date. Although CPQ11-14 has been previously used in studies from the Indian sub-continent, the instrument has never been tested for cross-cultural adaptability. This study aimed to assess the validity and reliability of CPQ11-14 in Telugu speaking Indian school children. Primary school children of Medak district, Telangana State, India, were recruited by a multi-stage probability sampling method. The translated questionnaire was initially pilot tested on a small subset of children (n = 40). Children with informed consent from parents (N = 1342) were then provided with questionnaires containing the Telugu translation of CPQ11-14, followed by a clinical examination conducted by a single examiner, using Basic WHO survey methods for dental caries, malocclusion, and Dean's Fluorosis index. Children (n = 161) in randomly chosen schools were re-administered the same questionnaire after a two week interval to test reliability of CPQ11-14 on repeated administrations. Internal consistency and test-retest reliability as determined by Cronbach's alpha and Intra-class correlation coefficient for overall CPQ11-14 scale were 0.925 and 0.923, respectively. CPQ11-14 discriminated between the categories of fluorosis and malocclusion while its discriminant validity with respect to dental caries was limited. CPQ11-14 also demonstrated good construct validity with both overall CPQ11-14 and its subscales having significant positive correlation with global ratings of oral health and overall wellbeing, even after adjusting for confounding variables. CPQ11-14 had a correlation of 0.405 with self-evaluated oral health and 0.407 with self-evaluated impact of oral health on overall wellbeing. In conclusion, Telugu translation of CPQ11-14 demonstrated good internal consistency and excellent reliability on repeated administrations after two weeks. It also exhibited good discriminant and construct validity.

Bilateral cross-bite treated by repeated rapid maxillary expansions: a 17-year follow-up case.

PubMed

Cozzani, M; Mazzotta, L; Caprioglio, A

2014-07-01

The objective of this paper is to show the clinical results after the repeated application of a Haas expander for rapid maxillary expansion (RME) anchored onto deciduous teeth in a 7-year-old patient that presented bilateral cross-bite, superior crowding and no space for permanent lateral incisors eruption. A first Haas expander was applied to the patient. She was told to activate it once a day, each activation was equal to 0.20 mm. After the first RME, the bilateral cross-bite was solved but still there was not enough space for lateral incisor eruption. A second and then a third Haas expander were applied, with the same activation protocol as the first one, in order to gain space in the anterior region and to achieve proper eruption of the lateral incisors. The patient was then treated with fixed appliances. At debonding the patient presented well aligned arch-forms: space for lateral incisor eruption was gained and superior crowding was solved. Bilateral cross-bite was also corrected. She was seen again 10 years and 17 years after expansions: she showed no relapse and presented a good functional occlusion that had remained stable, and an aesthetically pleasant smile, however she exhibited gingival recessions. Repeated rapid maxillary expansion, anchored onto deciduous teeth, performed in early mixed dentition represents a safe and successful treatment to correct severe bilateral cross- bites and to create space for maxillary incisor eruption.

Comparison of Repeatability and Agreement between Swept-Source Optical Biometry and Dual-Scheimpflug Topography.

PubMed

Jung, Soyeon; Chin, Hee Seung; Kim, Na Rae; Lee, Kang Won; Jung, Ji Won

2017-01-01

To assess the repeatability and agreement of parameters obtained with two biometers and to compare the predictability. Biometry was performed on 101 eyes with cataract using the IOLMaster 700 and the Galilei G6. Three measurements were obtained per eye with each device, and repeatability was evaluated. The axial length (AL), anterior chamber depth (ACD), keratometry (K), white-to-white (WTW) corneal diameter, central corneal thickness (CCT), and lens thickness (LT) were measured and postoperative predictability was compared. Measurements could not be obtained with the IOLMaster 700 in one eye and in seven eyes with the Galilei G6 due to dense cataract. Both the IOLMaster 700 and Galilei G6 showed good repeatability, although the IOLMaster 700 showed better repeatability than the Galilei G6. There were no statistically significant differences in AL, ACD, steepest K, WTW, and LT ( P > 0.050), although flattest K, mean K, and CCT differed ( P < 0.050). The proportion of eyes with an absolute prediction error within 0.5 D was 85.0% for the IOLMaster 700 and was 80.0% for the Galilei G6 based on the SRK/T formula. Two biometers showed high repeatability and relatively good agreements. The swept-source optical biometer demonstrated better repeatability, penetration, and an overall lower prediction error.

Oxygen-weighted Hyperpolarized 3He MR Imaging: A Short-term Reproducibility Study in Human Subjects

PubMed Central

Ishii, Masaru; Hamedani, Hooman; Clapp, Justin T.; Kadlecek, Stephen J.; Xin, Yi; Gefter, Warren B.; Rossman, Milton D.

2015-01-01

Purpose To determine whether hyperpolarized helium 3 magnetic resonance (MR) imaging to measure alveolar partial pressure of oxygen (Pao2) shows sufficient test-retest repeatability and between-cohort differences to be used as a reliable technique for detection of alterations in gas exchange in asymptomatic smokers. Materials and Methods The protocol was approved by the local institutional review board and was HIPAA compliant. Informed consent was obtained from all subjects. Two sets of MR images were obtained 10 minutes apart in 25 subjects: 10 nonsmokers (five men, five women; mean ± standard deviation age, 50 years ± 6) and 15 smokers (seven women, eight men; mean age, 50 years ± 8). A mixed-effects model was developed to identify the regional repeatability of Pao2 measurements as an intraclass correlation coefficient. Ten smokers were matched with the 10 nonsmokers on the basis of signal-to-noise ratio (SNR). Three separate models were generated: one for nonsmokers, one for the SNR-matched smokers, and one for the five remaining smokers, who were imaged with a significantly higher SNR. Results Short-term back-to-back regional reproducibility was assessed by using intraclass correlation coefficients, which were 0.67 and 0.65 for SNR case-matched nonsmokers and smokers, respectively. Repeatability was a strong function of SNR; a 50% increase in SNR in the remaining smokers improved the intraclass correlation coefficient to 0.82. Although repeatability was not significantly different between the SNR-matched cohorts (P = .44), the smoker group showed higher spatial and temporal variability in Pao2. Conclusion The short-term test-retest repeatability of hyperpolarized gas MR imaging of regional Pao2 was good. Asymptomatic smokers exhibited greater spatial and temporal variability in Pao2 than did the nonsmokers, which suggests that this parameter allows detection of small functional alterations associated with smoking. © RSNA, 2015 Online supplemental material is available for this article. PMID:26110668

Repeating firing fields of CA1 neurons shift forward in response to increasing angular velocity.

PubMed

Cowen, Stephen L; Nitz, Douglas A

2014-01-01

Self-motion information influences spatially-specific firing patterns exhibited by hippocampal neurons. Moreover, these firing patterns can repeat across similar subsegments of an environment, provided that there is similarity of path shape and head orientations across subsegments. The influence of self-motion variables on repeating fields remains to be determined. To investigate the role of path shape and angular rotation on hippocampal activity, we recorded the activity of CA1 neurons from rats trained to run on spiral-shaped tracks. During inbound traversals of circular-spiral tracks, angular velocity increases continuously. Under this condition, most neurons (74%) exhibited repeating fields across at least three adjacent loops. Of these neurons, 86% exhibited forward shifts in the angles of field centers relative to centers on preceding loops. Shifts were absent on squared-spiral tracks, minimal and less reliable on concentric-circle tracks, and absent on outward-bound runs on circular-spiral tracks. However, outward-bound runs on the circular-spiral track in the dark were associated with backward shifts. Together, the most parsimonious interpretation of the results is that continuous increases or decreases in angular velocity are particularly effective at shifting the center of mass of repeating fields, although it is also possible that a nonlinear integration of step counts contributes to the shift. Furthermore, the unexpected absence of field shifts during outward journeys in light (but not darkness) suggests visual cues around the goal location anchored the map of space to an allocentric reference frame.

Substituted polyacetylene separation membrane

DOEpatents

Pinnau, I.; Morisato, Atsushi

1998-01-13

A separation membrane is described which is useful for gas separation, particularly separation of C{sub 2+} hydrocarbons from natural gas. The invention encompasses the membrane itself, methods of making it and processes for using it. The membrane comprises a polymer having repeating units of a hydrocarbon-based, disubstituted polyacetylene, having the general formula shown in the accompanying diagram, wherein R{sub 1} is chosen from the group consisting of C{sub 1}-C{sub 4} alkyl and phenyl, and wherein R{sub 2} is chosen from the group consisting of hydrogen and phenyl. In the most preferred embodiment, the membrane comprises poly(4-methyl-2-pentyne) [PMP]. The membrane exhibits good chemical resistance and has super-glassy properties with regard to separating certain large, condensable permeant species from smaller, less-condensable permeant species. The membranes may also be useful in other fluid separations. 4 figs.

A Fiber Bragg Grating Temperature Sensor for 2-400 K

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

Zaynetdinov, Madrakhim; See, Erich M.; Geist, Brian

2015-03-01

We demonstrate fiber optic, multiplexible temperature sensing using a fiber Bragg grating (FBG) with an operational range of 2-400 K, and a temperature resolution better than 10 mK for temperatures < 12 K. This represents a significant reduction in the lowest usable temperature as well as a significant increase in sensitivity at cryogenic temperatures compared with previously reported multiplexible solutions. This is accomplished by mounting the section of the fiber with a FBG on a polytetrafluoroethylene coupon, which has a non-negligible coefficient of thermal expansion down to < 4 K. The sensors exhibit a good stability over multiple temperature cyclesmore » and acceptable sensor-to-sensor repeatability. Possible applications for this sensor include distributed temperature sensing across superconducting elements and cryogenic temperature measurements in environments where electrical measurements are impractical or unsafe.« less

Optically stimulated luminescence of natural NaCl mineral from Dead Sea exposed to gamma radiation.

PubMed

Roman-Lopez, J; Piña López, Y I; Cruz-Zaragoza, E; Marcazzó, J

2018-08-01

In this work, the continuous wave - optically stimulated luminescence (CW-OSL) emissions of natural salt minerals, collected from Dead Sea in summer of 2015, were studied. The CW-OSL dose response of natural salt showed a linear range between 0.5Gy and 10Gy of gamma radiation of 60 Co. Samples exposed at 3Gy exhibited good repeatability with a variation coefficient of 4.6%. The CW-OSL response as function of the preheating temperature (50-250°C) was analyzed. An increase of 15% of the CW-OSL response was observed in NaCl samples during storage period of 336h. The results showed that the natural Dead Sea salt minerals could be applied as natural dosimeter of gamma radiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Repeated-batch fermentations of xylose and glucose-xylose mixtures using a respiration-deficient Saccharomyces cerevisiae engineered for xylose metabolism.

PubMed

Kim, Soo Rin; Lee, Ki-Sung; Choi, Jin-Ho; Ha, Suk-Jin; Kweon, Dae-Hyuk; Seo, Jin-Ho; Jin, Yong-Su

2010-11-01

Xylose-fermenting Saccharomyces strains are needed for commercialization of ethanol production from lignocellulosic biomass. Engineered Saccharomyces cerevisiae strains expressing XYL1, XYL2 and XYL3 from Pichia stipitis, however, utilize xylose in an oxidative manner, which results in significantly lower ethanol yields from xylose as compared to glucose. As such, we hypothesized that reconfiguration of xylose metabolism from oxidative into fermentative manner might lead to efficient ethanol production from xylose. To this end, we generated a respiration-deficient (RD) mutant in order to enforce engineered S. cerevisiae to utilize xylose only through fermentative metabolic routes. Three different repeated-batch fermentations were performed to characterize characteristics of the respiration-deficient mutant. When fermenting glucose as a sole carbon source, the RD mutant exhibited near theoretical ethanol yields (0.46 g g(-1)) during repeated-batch fermentations by recycling the cells. As the repeated-batch fermentation progressed, the volumetric ethanol productivity increased (from 7.5 to 8.3 g L(-1)h(-1)) because of the increased biomass from previous cultures. On the contrary, the mutant showed decreasing volumetric ethanol productivities during the repeated-batch fermentations using xylose as sole carbon source (from 0.4 to 0.3 g L(-1)h(-1)). The mutant did not grow on xylose and lost fermenting ability gradually, indicating that the RD mutant cannot maintain a good fermenting ability on xylose as a sole carbon source. However, the RD mutant was capable of fermenting a mixture of glucose and xylose with stable yields (0.35 g g(-1)) and productivities (0.52 g L(-1)h(-1)) during the repeated-batch fermentation. In addition, ethanol yields from xylose during the mixed sugar fermentation (0.30 g g(-1)) were higher than ethanol yields from xylose as a sole carbon source (0.21 g g(-1)). These results suggest that a strategy for increasing ethanol yield through respiration-deficiency can be applied for the fermentation of lignocellulosic hydrolyzates containing glucose and xylose. Copyright © 2010 Elsevier B.V. All rights reserved.

Genetic Variation of the Dopamine Transporter (DAT1) Influences the Acute Subjective Responses to Cocaine in Volunteers with Cocaine Use Disorders

PubMed Central

Brewer, Alex J.; Nielsen, David A.; Spellicy, Catherine J.; Hamon, Sara C.; Gingrich, Justin; Thompson-Lake, Daisy G. Y.; Nielsen, Ellen M.; Mahoney, James J.; Kosten, Thomas R.; Newton, Thomas F.; De La Garza, Richard

2015-01-01

Objective : The aim of this study was to identify gene variants of DAT1 (SLC6A3) that modulate subjective responses to acute cocaine exposure. Methods Non-treatment seeking volunteers with cocaine use disorders (CUDs) received a single bolus infusion of saline and cocaine (40 mg, IV) in randomized order. Subjective effects were assessed with visual analog scales administered before (-15 min) and up to 20 min after infusion. Subjective effects ratings were normalized to baseline and saline infusion values were subtracted. Data was analyzed using repeated measures ANOVA. DNA from subjects was genotyped for the DAT1 intron 8 (rs3836790) and 3’ UTR (rs28363170) variable number of tandem repeats. Results Participants were mostly male (~80%) and African American (~70%). No differences were found among drug use variables between groups for either polymorphism. Carriers of the 9-allele of the DAT1 3’ UTR (9,9 and 9,10) (n = 24) exhibited greater responses to cocaine for “high”, “any drug effect”, “anxious”, and “stimulated” (all p-values < 0.001) compared to individuals homozygous for the 10-allele (n = 33). For the intron 8 polymorphism, individuals homozygous for the 6 allele exhibited greater responses for “anxious” than carriers of the 5 allele (p < 0.001). Individuals possessing the genotype pattern of 10,10 and at least one 5-allele reported lower responses to “good effects”, “bad effects”, “depressed”, and “anxious” (all p-values < 0.01). Conclusions The data presented here support the hypothesis that genetic differences of DAT1 contribute to variation of subjective responses to cocaine among participants with CUDs. PMID:25850966

The role of risk aversion in non-conscious decision making.

PubMed

Wang, Shuo; Krajbich, Ian; Adolphs, Ralph; Tsuchiya, Naotsugu

2012-01-01

To what extent can people choose advantageously without knowing why they are making those choices? This hotly debated question has capitalized on the Iowa Gambling Task (IGT), in which people often learn to choose advantageously without appearing to know why. However, because the IGT is unconstrained in many respects, this finding remains debated and other interpretations are possible (e.g., risk aversion, ambiguity aversion, limits of working memory, or insensitivity to reward/punishment can explain the finding of the IGT). Here we devised an improved variant of the IGT in which the deck-payoff contingency switches after subjects repeatedly choose from a good deck, offering the statistical power of repeated within-subject measures based on learning the reward contingencies associated with each deck. We found that participants exhibited low confidence in their choices, as probed with post-decision wagering, despite high accuracy in selecting advantageous decks in the task, which is putative evidence for non-conscious decision making. However, such a behavioral dissociation could also be explained by risk aversion, a tendency to avoid risky decisions under uncertainty. By explicitly measuring risk aversion for each individual, we predicted subjects' post-decision wagering using Bayesian modeling. We found that risk aversion indeed does play a role, but that it did not explain the entire effect. Moreover, independently measured risk aversion was uncorrelated with risk aversion exhibited during our version of the IGT, raising the possibility that the latter risk aversion may be non-conscious. Our findings support the idea that people can make optimal choices without being fully aware of the basis of their decision. We suggest that non-conscious decision making may be mediated by emotional feelings of risk that are based on mechanisms distinct from those that support cognitive assessment of risk.

The Role of Risk Aversion in Non-Conscious Decision Making

PubMed Central

Wang, Shuo; Krajbich, Ian; Adolphs, Ralph; Tsuchiya, Naotsugu

2012-01-01

To what extent can people choose advantageously without knowing why they are making those choices? This hotly debated question has capitalized on the Iowa Gambling Task (IGT), in which people often learn to choose advantageously without appearing to know why. However, because the IGT is unconstrained in many respects, this finding remains debated and other interpretations are possible (e.g., risk aversion, ambiguity aversion, limits of working memory, or insensitivity to reward/punishment can explain the finding of the IGT). Here we devised an improved variant of the IGT in which the deck-payoff contingency switches after subjects repeatedly choose from a good deck, offering the statistical power of repeated within-subject measures based on learning the reward contingencies associated with each deck. We found that participants exhibited low confidence in their choices, as probed with post-decision wagering, despite high accuracy in selecting advantageous decks in the task, which is putative evidence for non-conscious decision making. However, such a behavioral dissociation could also be explained by risk aversion, a tendency to avoid risky decisions under uncertainty. By explicitly measuring risk aversion for each individual, we predicted subjects’ post-decision wagering using Bayesian modeling. We found that risk aversion indeed does play a role, but that it did not explain the entire effect. Moreover, independently measured risk aversion was uncorrelated with risk aversion exhibited during our version of the IGT, raising the possibility that the latter risk aversion may be non-conscious. Our findings support the idea that people can make optimal choices without being fully aware of the basis of their decision. We suggest that non-conscious decision making may be mediated by emotional feelings of risk that are based on mechanisms distinct from those that support cognitive assessment of risk. PMID:22375133

How reproducible is cutaneous electrogastrography? An in-depth evidence-based study.

PubMed

Jonderko, K; Kasicka-Jonderko, A; Krusiec-Swidergoł, B; Dzielicki, M; Strój, L; Doliński, M; Doliński, K; Błońska-Fajfrowska, B

2005-12-01

To check on reproducibility of parameters of the cutaneous electrogastrogram registered at a close or a distant time span. Twenty-two volunteers recruited by an advertisement (11 females and 11 males, median age 25 years, range: 18-35) underwent three surface electrogastrography examinations of which two were taken on consecutive days and the third one was accomplished at least 2 weeks before or after the two other sessions. The examination involved a 30-min fasted recording, followed by a 90-min postprandial registration after intake of a 394-kcal mixed solid-liquid test meal. Parameters of the electrogastrogram pertaining to the frequency of the gastric slow waves exhibited good to moderate reproducibility, whereas fair reproducibility characterized parameters expected to describe the power of gastric slow waves. With the exception of the difference fed minus fasted power (DeltaDP), in no instance was the medium term reproducibility any worse than the short term one. Categorical data analysis revealed that the relative time share of normogastria postprandially exhibited a better reproducibility than in the fasted period. The Cohen's kappa-value of 0.459 for the DeltaDP for the medium term reproducibility placed this parameter within the range of moderate agreement between repeat examinations. Of the two two-parameter combinations considered, the alliance of the fasted and fed normogastria performed worse than any of those parameters considered alone, whereas a combination of the DeltaDP with the fed-state normogastria revealed a kappa-value amounting to 0.510 for the medium term reproducibility. The feasibility of some electrogastrographic parameters to convey clinically useful information may be hampered by their fair reproducibility. Recoding of parameters of the cutaneous electrogastrogram from primary continuous to secondary categorical may help achieve a better agreement between repeat examinations.

Validity and reliability of the Spanish version of the Organizational Readiness for Knowledge Translation (OR4KT) questionnaire.

PubMed

Grandes, Gonzalo; Bully, Paola; Martinez, Catalina; Gagnon, Marie-Pierre

2017-11-10

Organizational readiness to change healthcare practice is a major determinant of successful implementation of evidence-based interventions. However, we lack of comprehensive, valid, and reliable instruments to measure it. We assessed the validity and reliability of the Spanish version of the Organizational Readiness for Knowledge Translation (OR4KT) questionnaire in the context of the implementation of the Prescribe Vida Saludable III project, which seeks to strengthen health promotion and chronic disease prevention in primary healthcare organizations of the Osakidetza (Basque Health Service, Spain). A cross-sectional study was conducted including 127 professionals from 20 primary care centers within Osakidetza. They filled in the OR4KT questionnaire twice in a 15- to 30-day period to test repeatability. In addition, we used the Survey of Organizational Attributes for Primary Care (SOAPC) and we documented the number of healthcare professionals who formally engaged in the Prescribe Vida Saludable III project within each participating center to assess concurrent validity. Cronbach's alpha for the overall OR4KT was .95, and the overall repeatability coefficient was 6.95%, both excellent results. Confirmatory factor analysis supported the underlying theoretical structure of 6 dimensions and 23 sub-dimensions. There were positive moderate-to-high internal correlations between these six dimensions, and there was evidence of good concurrent validity (correlation coefficient of .76 with SOAPC, and .80 with the proportion of professionals engaged by center). A score higher than 64 (out of 100) would be indicative of an organization with high level of readiness to implement the intervention (sensitivity = .75, specificity = 1). The Spanish version of the OR4KT exhibits very strong reliability and good validity, although it needs to be validated in a larger sample and in different implementation contexts.

Environmental Impact of Ionic Liquids: Automated Evaluation of the Chemical Oxygen Demand of Photochemically Degraded Compounds.

PubMed

Costa, Susana P F; Pereira, Sarah A P; Pinto, Paula C A G; Araujo, André R T S; Passos, Marieta L C; Saraiva, M Lúcia M F S

2017-05-19

A novel automated fluorimetric technique was developed for the assessment of the chemical oxygen demand (COD) of ionic liquids (ILs) and combined with a photodegradation step to promote IL degradation. The method was implemented on a sequential injection analysis (SIA) system and is based on the reduction of cerium(IV) in the presence of irradiated ILs. Compounds incorporating the chloride anion were found to exhibit higher COD values and 1-butyl-3-methylimidazolium chloride ([bmim] + [Cl] - ), 1-butyl-1-methylpyrrolidinium chloride ([bmpyr] + [Cl] - ), and1-hexyl-3-methylimidazolium chloride ([hmim] + [Cl] - ) also exhibited considerable photodegradability, whereas the cholinium cation and methanesulfonate and tetrafluoroborate anions showed resistance to photolysis. The developed methodology proved to be a simple, affordable, and robust method, showing good repeatability under the tested conditions (rsd <3.5 %, n=10). Therefore, it is expected that the developed approach can be used as a screening method for the preliminary evaluation of compounds' potential impact in the aquatic field. Additionally, the photolysis step presents an attractive option to promote degradation of ILs prior to their release into wastewater. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of quantum dots CdTe decorated graphene composite for sensitive detection of uric acid and dopamine.

PubMed

Yu, Hong-Wei; Jiang, Jing-Hui; Zhang, Ze; Wan, Guang-Cai; Liu, Zhi-Yong; Chang, Dong; Pan, Hong-Zhi

2017-02-15

The assembly of quantum dots (QDs) in a simply method opens up opportunities to obtain access to the full potential of assembled QDs by virtue of the collective properties of the ensembles. In this study, quantum dots CdTe and graphene (Gr) nanocomposite was constructed for the simultaneous determination of uric acid (UA) and dopamine (DA). The CdTe QDs-Gr nanocomposite was prepared by ultrasonication and was characterized with microscopic techniques. The nanocomposite modified electrode was characterized by cyclicvoltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Due to the synergistic effects between CdTe QDs and Gr, the fabricated electrode exhibited excellent electrochemical catalytic activities, good biological compatibility and high sensitivity toward the oxidation of UA and DA. Under optimum conditions, in the co-existence system the linear calibration plots for UA and DA were obtained over the range of 3-600 μM and 1-500 μM with detection limits of 1.0 μM and 0.33 μM. The fabricated biosensor also exhibits the excellent repeatability, reproducibility, storage stability along with acceptable selectivity. Copyright © 2016. Published by Elsevier Inc.

Synergistic effect of N-decorated and Mn2+ doped ZnO nanofibers with enhanced photocatalytic activity

PubMed Central

Wang, Yuting; Cheng, Jing; Yu, Suye; Alcocer, Enric Juan; Shahid, Muhammad; Wang, Ziyuan; Pan, Wei

2016-01-01

Here we report a high efficiency photocatalyst, i.e., Mn2+-doped and N-decorated ZnO nanofibers (NFs) enriched with vacancy defects, fabricated via electrospinning and a subsequent controlled annealing process. This nanocatalyst exhibits excellent visible-light photocatalytic activity and an apparent quantum efficiency up to 12.77%, which is 50 times higher than that of pure ZnO. It also demonstrates good stability and durability in repeated photocatalytic degradation experiments. A comprehensive structural analysis shows that high density of oxygen vacancies and nitrogen are introduced into the nanofibers surface. Hence, the significant enhanced visible photocatalytic properties for Mn-ZnO NFs are due to the synergetic effects of both Mn2+ doping and N decorated. Further investigations exhibit that the Mn2+-doping facilitates the formation of N-decorated and surface defects when annealing in N2 atmosphere. N doping induce the huge band gap decrease and thus significantly enhance the absorption of ZnO nanofibers in the range of visible-light. Overall, this paper provides a new approach to fabricate visible-light nanocatalysts using both doping and annealing under anoxic ambient. PMID:27600260

Membrane Introduction Mass Spectrometry Combined with an Orthogonal Partial-Least Squares Calibration Model for Mixture Analysis.

PubMed

Li, Min; Zhang, Lu; Yao, Xiaolong; Jiang, Xingyu

2017-01-01

The emerging membrane introduction mass spectrometry technique has been successfully used to detect benzene, toluene, ethyl benzene and xylene (BTEX), while overlapped spectra have unfortunately hindered its further application to the analysis of mixtures. Multivariate calibration, an efficient method to analyze mixtures, has been widely applied. In this paper, we compared univariate and multivariate analyses for quantification of the individual components of mixture samples. The results showed that the univariate analysis creates poor models with regression coefficients of 0.912, 0.867, 0.440 and 0.351 for BTEX, respectively. For multivariate analysis, a comparison to the partial-least squares (PLS) model shows that the orthogonal partial-least squares (OPLS) regression exhibits an optimal performance with regression coefficients of 0.995, 0.999, 0.980 and 0.976, favorable calibration parameters (RMSEC and RMSECV) and a favorable validation parameter (RMSEP). Furthermore, the OPLS exhibits a good recovery of 73.86 - 122.20% and relative standard deviation (RSD) of the repeatability of 1.14 - 4.87%. Thus, MIMS coupled with the OPLS regression provides an optimal approach for a quantitative BTEX mixture analysis in monitoring and predicting water pollution.

Sensitive and selective determination of polycyclic aromatic hydrocarbons in mainstream cigarette smoke using a graphene-coated solid-phase microextraction fiber prior to GC/MS.

PubMed

Wang, Xiaoyu; Wang, Yuan; Qin, Yaqiong; Ding, Li; Chen, Yi; Xie, Fuwei

2015-08-01

A simple method has been developed for the simultaneous determination of 16 polycyclic aromatic hydrocarbons (PAHs) in mainstream cigarette smoke. The procedure is based on employing a homemade graphene-coated solid-phase microextraction (SPME) fiber for extraction prior to GC/MS. In comparison to commercial 100-μm poly(dimethyl siloxane) (PDMS) fiber, the graphene-coated SPME fiber exhibits advantageous cleanup and preconcentration efficiencies. By collecting the particulate phase 5 cigarettes, the LODs and LOQs of 16 target PAHs were 0.02-0.07 and 0.07-0.22 ng/cigarette, respectively, and all of the linear correlation efficiencies were larger than 0.995. The validation results also indicate that the method has good repeatability (RSD between 4.2% and 9.5%) and accuracy (spiked recoveries between 80% and 110%). The developed method was applied to analyze two Kentucky reference cigarettes (1R5F and 3R4F) and six Chinese brands of cigarettes. In addition, the PAH concentrations in the particulate phase of the smoke from the 1R5F Kentucky cigarettes were in good agreement with recently reported results. Due to easy operation and good validation results, this SPME-GC/MS method may be an excellent alternative for trace analysis of PAHs in cigarette smoke. Copyright © 2015 Elsevier B.V. All rights reserved.

Hierarchical Graphene coating for highly sensitive solid phase microextraction of organochlorine pesticides.

PubMed

Wang, Fuxin; Liu, Shuqin; Yang, Hao; Zheng, Juan; Qiu, Junlang; Xu, Jianqiao; Tong, Yexiang; Zhu, Fang; Ouyang, Gangfeng

2016-11-01

Graphene, a novel class of carbon nanostructures, has received great attention as sorbents due to its fascinating structures, ultrahigh specific surface area, and good extraction ability. In this paper, a new type of hierarchical graphene was synthesized through employing a mild and environment-friendly method. Such 3D interconnected graphene own a high specific surface area up to 524m(2)g(-1), which is about 2.5 fold larger than the graphene, since the synthetic material has interlayer pores between nanosheets and in-plane pores. Then a superior solid-phase microextraction fiber was fabricated by sequentially coating the stainless steel fiber with silicone sealant film and hierarchical graphene powder. Since the novel hierarchical graphene possessed large surface area and good adsorption property, the as-prepared fiber exhibited good extraction properties of the organochlorine pesticides (OCPs). As for the analytical performance, the as-prepared fiber achieved low detection limits (0.08-0.80ngL(-1)) and wide linearity (10-30,000ngL(-1)) under the optimal conditions. The repeatability (n=5) for single fiber were between 5.1% and 11%, while the reproducibility (n=3) of fiber-to-fiber were range from 6.2% to14%. Moreover, the fiber was successfully applied to the analysis of OCPs in the Pearl River water. Copyright © 2016 Elsevier B.V. All rights reserved.

Using the Reggio Exhibit to Enrich Teacher Candidates' Perceptions of How Children Construct and Represent Knowledge

ERIC Educational Resources Information Center

Ede, Anita R.; Da Ros-Voseles, Denise A.

2010-01-01

This teacher research study explores the changes in early childhood teacher candidates' perceptions of how children construct and represent knowledge following repeated exposure to "The Wonder of Learning: the Hundred Languages of Children" exhibit. When the renowned exhibit from Reggio Emilia was housed on the study participants' campus for 6…

Hybrid molecularly imprinted polymers synthesized with 3-aminopropyltriethoxysilane-methacrylic acid monomer for miniaturized solid-phase extraction: A new and economical sample preparation strategy for determination of acyclovir in urine.

PubMed

Yan, Hongyuan; Wang, Mingyu; Han, Yehong; Qiao, Fengxia; Row, Kyung Ho

2014-06-13

The miniaturized molecularly imprinted solid-phase extraction (mini-MISPE) coupled with high-performance liquid chromatography was proposed for the determination of acyclovir in urine. 1.5-mL tapered plastic centrifuge tube filled with hybrid molecularly imprinted polymers (HMIPs) was used as the cartridge of mini-MISPE, and the HMIPs synthesized with 3-aminopropyltriethoxy silane-methacrylic acid as monomer exhibited good recognition and selectivity for acyclovir. Under the optimized condition, good linear calibration was obtained in a range of 0.5-15μgmL(-1) with the correlation coefficient of 0.9994, and the recoveries at three spiked levels were 91.6-103.3% in urine with the relative standard deviation (RSD) of ≤3.5%. Excellent intra-day and inter-day repeatability were achieved with RSD of ≤2.6% and 4.0% in three different concentrations. This method combined the advantages of HMIPs and mini-MISPE, and it could become an alternative tool for analyzing the residues of acyclovir in complex urine matrices. Copyright © 2014 Elsevier B.V. All rights reserved.

Layer-by-Layer Self-Assembling Gold Nanorods and Glucose Oxidase onto Carbon Nanotubes Functionalized Sol-Gel Matrix for an Amperometric Glucose Biosensor.

PubMed

Wu, Baoyan; Hou, Shihua; Miao, Zhiying; Zhang, Cong; Ji, Yanhong

2015-09-18

A novel amperometric glucose biosensor was fabricated by layer-by-layer self-assembly of gold nanorods (AuNRs) and glucose oxidase (GOD) onto single-walled carbon nanotubes (SWCNTs)-functionalized three-dimensional sol-gel matrix. A thiolated aqueous silica sol containing SWCNTs was first assembled on the surface of a cleaned Au electrode, and then the alternate self-assembly of AuNRs and GOD were repeated to assemble multilayer films of AuNRs-GOD onto SWCNTs-functionalized silica gel for optimizing the biosensor. Among the resulting glucose biosensors, the four layers of AuNRs-GOD-modified electrode showed the best performance. The sol-SWCNTs-(AuNRs- GOD)₄/Au biosensor exhibited a good linear range of 0.01-8 mM glucose, high sensitivity of 1.08 μA/mM, and fast amperometric response within 4 s. The good performance of the proposed glucose biosensor could be mainly attributed to the advantages of the three-dimensional sol-gel matrix and stereo self-assembly films, and the natural features of one-dimensional nanostructure SWCNTs and AuNRs. This study may provide a new facile way to fabricate the enzyme-based biosensor with high performance.

Indirect electrocatalytic determination of choline by monitoring hydrogen peroxide at the choline oxidase-prussian blue modified iron phosphate nanostructures.

PubMed

Zhang, Hui; Yin, Yajing; Wu, Ping; Cai, Chenxin

2012-01-15

Choline, as a marker of cholinergic activity in brain tissue, is very important in biological and clinical analysis, especially in the clinical detection of the neurodegenerative disorders disease. This work presents an electrochemical approach for the detection of choline based on prussian blue modified iron phosphate nanostructures (PB-FePO(4)). The obtained nanostructures showed a good catalysis toward the electroreduction of H(2)O(2), and an amperometric choline biosensor was developed by immobilizing choline oxidase on the PB-FePO(4) nanostructures. The biosensor exhibited a rapid response (ca. 2s), low detection limit (0.4±0.05 μM), wide linear range (2 μM to 3.2 mM), high sensitivity (~75.2 μAm M(-1) cm(-2)), as well as good stability and repeatability. In addition, the common interfering species, such as ascorbic acid, uric acid and 4-acetamidophenol did not cause obvious interference due to the low detection potential (-0.05 V versus saturated calomel electrode). This nanostructure could be used as a promise platform for the construction of other oxidase-based biosensors. Copyright © 2011 Elsevier B.V. All rights reserved.

Single-cell forensic short tandem repeat typing within microfluidic droplets.

PubMed

Geng, Tao; Novak, Richard; Mathies, Richard A

2014-01-07

A short tandem repeat (STR) typing method is developed for forensic identification of individual cells. In our strategy, monodisperse 1.5 nL agarose-in-oil droplets are produced with a high frequency using a microfluidic droplet generator. Statistically dilute single cells, along with primer-functionalized microbeads, are randomly compartmentalized in the droplets. Massively parallel single-cell droplet polymerase chain reaction (PCR) is performed to transfer replicas of desired STR targets from the single-cell genomic DNA onto the coencapsulated microbeads. These DNA-conjugated beads are subsequently harvested and reamplified under statistically dilute conditions for conventional capillary electrophoresis (CE) STR fragment size analysis. The 9-plex STR profiles of single cells from both pure and mixed populations of GM09947 and GM09948 human lymphoid cells show that all alleles are correctly called and allelic drop-in/drop-out is not observed. The cell mixture study exhibits a good linear relationship between the observed and input cell ratios in the range of 1:1 to 10:1. Additionally, the STR profile of GM09947 cells could be deduced even in the presence of a high concentration of cell-free contaminating 9948 genomic DNA. Our method will be valuable for the STR analysis of samples containing mixtures of cells/DNA from multiple contributors and for low-concentration samples.

New Tunneling Features in Polar III-Nitride Resonant Tunneling Diodes

NASA Astrophysics Data System (ADS)

Encomendero, Jimy; Faria, Faiza Afroz; Islam, S. M.; Protasenko, Vladimir; Rouvimov, Sergei; Sensale-Rodriguez, Berardi; Fay, Patrick; Jena, Debdeep; Xing, Huili Grace

2017-10-01

For the past two decades, repeatable resonant tunneling transport of electrons in III-nitride double barrier heterostructures has remained elusive at room temperature. In this work we theoretically and experimentally study III-nitride double-barrier resonant tunneling diodes (RTDs), the quantum transport characteristics of which exhibit new features that are unexplainable using existing semiconductor theory. The repeatable and robust resonant transport in our devices enables us to track the origin of these features to the broken inversion symmetry in the uniaxial crystal structure, which generates built-in spontaneous and piezoelectric polarization fields. Resonant tunneling transport enabled by the ground state as well as by the first excited state is demonstrated for the first time over a wide temperature window in planar III-nitride RTDs. An analytical transport model for polar resonant tunneling heterostructures is introduced for the first time, showing a good quantitative agreement with experimental data. From this model we realize that tunneling transport is an extremely sensitive measure of the built-in polarization fields. Since such electric fields play a crucial role in the design of electronic and photonic devices, but are difficult to measure, our work provides a completely new method to accurately determine their magnitude for the entire class of polar heterostructures.

Retrieval and Sleep Both Counteract the Forgetting of Spatial Information

ERIC Educational Resources Information Center

Antony, James W.; Paller, Ken A.

2018-01-01

Repeatedly studying information is a good way to strengthen memory storage. Nevertheless, testing recall often produces superior long-term retention. Demonstrations of this testing effect, typically with verbal stimuli, have shown that repeated retrieval through testing reduces forgetting. Sleep also benefits memory storage, perhaps through…

Diamond-based electrochemical aptasensor realizing a femtomolar detection limit of bisphenol A.

PubMed

Ma, Yibo; Liu, Junsong; Li, Hongdong

2017-06-15

In this study, we designed and fabricated an electrochemical impedance aptasensor based on Au nanoparticles (Au-NPs) coated boron-doped diamond (BDD) modified with aptamers, and 6-mercapto-1-hexanol (MCH) for the detection of bisphenol A (BPA). The constructed BPA aptasensor exhibits good linearity from 1.0×10 -14 to 1.0×10 -9 molL -1 . The detection limitation of 7.2×10 -15 molL -1 was achieved, which can be attributed to the synergistic effect of combining BDD with Au-NPs, aptamers, and MCH. The examine results of BPA traces in Tris-HCl buffer and in milk, UV spectra of aptamer/BPA and interference test revealed that the novel aptasensors are of high sensitivity, specificity, stability and repeatability, which could be promising in practical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Construction of MoS2/Si nanowire array heterojunction for ultrahigh-sensitivity gas sensor

NASA Astrophysics Data System (ADS)

Wu, Di; Lou, Zhenhua; Wang, Yuange; Xu, Tingting; Shi, Zhifeng; Xu, Junmin; Tian, Yongtao; Li, Xinjian

2017-10-01

Few-layer MoS2 thin films were synthesized by a two-step thermal decomposition process. In addition, MoS2/Si nanowire array (SiNWA) heterojunctions exhibiting excellent gas sensing properties were constructed and investigated. Further analysis reveals that such MoS2/SiNWA heterojunction devices are highly sensitive to nitric oxide (NO) gas under reverse voltages at room temperature (RT). The gas sensor demonstrated a minimum detection limit of 10 ppb, which represents the lowest value obtained for MoS2-based sensors, as well as an ultrahigh response of 3518% (50 ppm NO, ˜50% RH), with good repeatability and selectivity of the MoS2/SiNWA heterojunction. The sensing mechanisms were also discussed. The performance of the MoS2/SiNWA heterojunction gas sensors is superior to previous results, revealing that they have great potential in applications relating to highly sensitive gas sensors.

Organic bistable memory devices based on MoO3 nanoparticle embedded Alq3 structures.

PubMed

Abhijith, T; Kumar, T V Arun; Reddy, V S

2017-03-03

Organic bistable memory devices were fabricated by embedding a thin layer of molybdenum trioxide (MoO 3 ) between two tris-(8-hydroxyquinoline)aluminum (Alq 3 ) layers. The device exhibited excellent switching characteristics with an ON/OFF current ratio of 1.15 × 10 3 at a read voltage of 1 V. The device showed repeatable write-erase capability and good stability in both the conductance states. These conductance states are non-volatile in nature and can be obtained by applying appropriate voltage pulses. The effect of MoO 3 layer thickness and its location in the Alq 3 matrix on characteristics of the memory device was investigated. The field emission scanning electron microscopy (FE-SEM) images of the MoO 3 layer revealed the presence of isolated nanoparticles. Based on the experimental results, a mechanism has been proposed for explaining the conductance switching of fabricated devices.

Biosynthesis of glycerol carbonate from glycerol by lipase in dimethyl carbonate as the solvent.

PubMed

Lee, Kyung Hwa; Park, Chang-Ho; Lee, Eun Yeol

2010-11-01

Glycerol carbonate was synthesized from renewable glycerol and dimethyl carbonate using lipase in solvent-free reaction system in which excess dimethyl carbonate played as the reaction medium. A variety of lipases have been tested for their abilities to catalyze transesterification reaction, and Candida antartica lipase B and Novozyme 435 exhibited higher catalytic activities. The silica-coated glycerol with a 1:1 ratio was supplied to prevent two-phase formation between hydrophobic dimethyl carbonate and hydrophilic glycerol. Glycerol carbonate was successfully synthesized with more than 90% conversion from dimethyl carbonate and glycerol with a molar ratio of 10 using Novozyme 435-catalyzed transesterification at 70 °C. The Novozyme 435 [5% (w/w) and 20% (w/w)] and silica gel were more than four times recycled with good stability in a repeated batch operation for the solvent-free synthesis of glycerol carbonate.

Temperature-independent fiber-Bragg-grating-based atmospheric pressure sensor

NASA Astrophysics Data System (ADS)

Zhang, Zhiguo; Shen, Chunyan; Li, Luming

2018-03-01

Atmospheric pressure is an important way to achieve a high degree of measurement for modern aircrafts, moreover, it is also an indispensable parameter in the meteorological telemetry system. With the development of society, people are increasingly concerned about the weather. Accurate and convenient atmospheric pressure parameters can provide strong support for meteorological analysis. However, electronic atmospheric pressure sensors currently in application suffer from several shortcomings. After an analysis and discussion, we propose an innovative structural design, in which a vacuum membrane box and a temperature-independent strain sensor based on an equal strength cantilever beam structure and fiber Bragg grating (FBG) sensors are used. We provide experimental verification of that the atmospheric pressure sensor device has the characteristics of a simple structure, lack of an external power supply, automatic temperature compensation, and high sensitivity. The sensor system has good sensitivity, which can be up to 100 nm/MPa, and repeatability. In addition, the device exhibits desired hysteresis.

Good Liars Are Neither ‘Dark’ Nor Self-Deceptive

PubMed Central

Wright, Gordon R. T.; Berry, Christopher J.; Catmur, Caroline; Bird, Geoffrey

2015-01-01

Deception is a central component of the personality 'Dark Triad' (Machiavellianism, Psychopathy and Narcissism). However, whether individuals exhibiting high scores on Dark Triad measures have a heightened deceptive ability has received little experimental attention. The present study tested whether the ability to lie effectively, and to detect lies told by others, was related to Dark Triad, Lie Acceptability, or Self-Deceptive measures of personality using an interactive group-based deception task. At a group level, lie detection accuracy was correlated with the ability to deceive others—replicating previous work. No evidence was found to suggest that Dark Triad traits confer any advantage either to deceive others, or to detect deception in others. Participants who considered lying to be more acceptable were more skilled at lying, while self-deceptive individuals were generally less credible and less confident when lying. Results are interpreted within a framework in which repeated practice results in enhanced deceptive ability. PMID:26083765

Construction of MoS2/Si nanowire array heterojunction for ultrahigh-sensitivity gas sensor.

PubMed

Wu, Di; Lou, Zhenhua; Wang, Yuange; Xu, Tingting; Shi, Zhifeng; Xu, Junmin; Tian, Yongtao; Li, Xinjian

2017-10-27

Few-layer MoS 2 thin films were synthesized by a two-step thermal decomposition process. In addition, MoS 2 /Si nanowire array (SiNWA) heterojunctions exhibiting excellent gas sensing properties were constructed and investigated. Further analysis reveals that such MoS 2 /SiNWA heterojunction devices are highly sensitive to nitric oxide (NO) gas under reverse voltages at room temperature (RT). The gas sensor demonstrated a minimum detection limit of 10 ppb, which represents the lowest value obtained for MoS 2 -based sensors, as well as an ultrahigh response of 3518% (50 ppm NO, ∼50% RH), with good repeatability and selectivity of the MoS 2 /SiNWA heterojunction. The sensing mechanisms were also discussed. The performance of the MoS 2 /SiNWA heterojunction gas sensors is superior to previous results, revealing that they have great potential in applications relating to highly sensitive gas sensors.

Organic bistable memory devices based on MoO3 nanoparticle embedded Alq3 structures

NASA Astrophysics Data System (ADS)

Abhijith, T.; Kumar, T. V. Arun; Reddy, V. S.

2017-03-01

Organic bistable memory devices were fabricated by embedding a thin layer of molybdenum trioxide (MoO3) between two tris-(8-hydroxyquinoline)aluminum (Alq3) layers. The device exhibited excellent switching characteristics with an ON/OFF current ratio of 1.15 × 103 at a read voltage of 1 V. The device showed repeatable write-erase capability and good stability in both the conductance states. These conductance states are non-volatile in nature and can be obtained by applying appropriate voltage pulses. The effect of MoO3 layer thickness and its location in the Alq3 matrix on characteristics of the memory device was investigated. The field emission scanning electron microscopy (FE-SEM) images of the MoO3 layer revealed the presence of isolated nanoparticles. Based on the experimental results, a mechanism has been proposed for explaining the conductance switching of fabricated devices.

Development of a high-sensitivity plasticizer sensor based on a quartz crystal microbalance modified with a nanostructured nickel hydroxide film

NASA Astrophysics Data System (ADS)

Hu, Ruifen; Zhang, Kaihuan; Fan, Guokang; Luo, Zhiyuan; Li, Guang

2015-05-01

Nanostructured nickel hydroxide (nano-Ni(OH)2) was synthesized at a low temperature without annealing. Accordingly, a plasticizer sensor based on a quartz crystal microbalance (QCM) modified with the nano-Ni(OH)2 sensing film was fabricated to detect dibutyl phthalate (DBP) and its relative film thickness was optimized. The sensor worked at room temperature and exhibited a high sensitivity of 4.91 Hz ppb-1 to DBP in a low concentration range of 5-20 ppb, and an ultra-low detection limit of 5 ppb was achieved. In addition, the sensor maintained good repeatability as well as stability shown by the experimental data. The responses to five possible interferences and four other plasticizers were also measured, which indicated the excellent selectivity of the sensor and its potential use in monitoring plasticizers in a gaseous state.

Flame retardant polyphosphazenes

NASA Technical Reports Server (NTRS)

Paciorek, K. L.; Karle, D. W.; Kratzer, R. H.

1976-01-01

Three processes for the preparation of polyphosphazenes were investigated: (1) the reaction of bisphosphines with diazides, (2) the condensation of bisdichlorophosphoranes with diamines; and (3) the treatment of bisphosphines with diamines in the presence of carbon tetrachloride followed by base dehydrohalogenation. All products obtained were of low molecular weight; the degree of polymerization did not exceed twelve repeating units. However, several compositions exhibited good thermal stability. No weight loss was observed up to 390 C when heated in air at 5 C/min. Treatment of bisphosphines with either an excess of a diazide or an excess of a diamine in the presence of carbon tetrachloride resulted in the production of difunctional phosphazenes which were respectively, azido and amino terminated. The reaction of these azido terminated extended monomers with bisphosphines did not produce high molecular weight materials. The bis-aminophosphazene prepared for the first time under this contract was successfully incorporated into a polyimide.

Oxygen detection using evanescent fields

DOEpatents

Duan, Yixiang [Los Alamos, NM; Cao, Weenqing [Los Alamos, NM

2007-08-28

An apparatus and method for the detection of oxygen using optical fiber based evanescent light absorption. Methylene blue was immobilized using a sol-gel process on a portion of the exterior surface of an optical fiber for which the cladding has been removed, thereby forming an optical oxygen sensor. When light is directed through the optical fiber, transmitted light intensity varies as a result of changes in the absorption of evanescent light by the methylene blue in response to the oxygen concentration to which the sensor is exposed. The sensor was found to have a linear response to oxygen concentration on a semi-logarithmic scale within the oxygen concentration range between 0.6% and 20.9%, a response time and a recovery time of about 3 s, ant to exhibit good reversibility and repeatability. An increase in temperature from 21.degree. C. to 35.degree. C. does not affect the net absorption of the sensor.

Support vector machines-based fault diagnosis for turbo-pump rotor

NASA Astrophysics Data System (ADS)

Yuan, Sheng-Fa; Chu, Fu-Lei

2006-05-01

Most artificial intelligence methods used in fault diagnosis are based on empirical risk minimisation principle and have poor generalisation when fault samples are few. Support vector machines (SVM) is a new general machine-learning tool based on structural risk minimisation principle that exhibits good generalisation even when fault samples are few. Fault diagnosis based on SVM is discussed. Since basic SVM is originally designed for two-class classification, while most of fault diagnosis problems are multi-class cases, a new multi-class classification of SVM named 'one to others' algorithm is presented to solve the multi-class recognition problems. It is a binary tree classifier composed of several two-class classifiers organised by fault priority, which is simple, and has little repeated training amount, and the rate of training and recognition is expedited. The effectiveness of the method is verified by the application to the fault diagnosis for turbo pump rotor.

Length and sequence heterogeneity in 5S rDNA of Populus deltoides.

PubMed

Negi, Madan S; Rajagopal, Jyothi; Chauhan, Neeti; Cronn, Richard; Lakshmikumaran, Malathi

2002-12-01

The 5S rRNA genes and their associated non-transcribed spacer (NTS) regions are present as repeat units arranged in tandem arrays in plant genomes. Length heterogeneity in 5S rDNA repeats was previously identified in Populus deltoides and was also observed in the present study. Primers were designed to amplify the 5S rDNA NTS variants from the P. deltoides genome. The PCR-amplified products from the two accessions of P. deltoides (G3 and G48) suggested the presence of length heterogeneity of 5S rDNA units within and among accessions, and the size of the spacers ranged from 385 to 434 bp. Sequence analysis of the non-transcribed spacer (NTS) revealed two distinct classes of 5S rDNA within both accessions: class 1, which contained GAA trinucleotide microsatellite repeats, and class 2, which lacked the repeats. The class 1 spacer shows length variation owing to the microsatellite, with two clones exhibiting 10 GAA repeat units and one clone exhibiting 16 such repeat units. However, distance analysis shows that class 1 spacer sequences are highly similar inter se, yielding nucleotide diversity (pi) estimates that are less than 0.15% of those obtained for class 2 spacers (pi = 0.0183 vs. 0.1433, respectively). The presence of microsatellite in the NTS region leading to variation in spacer length is reported and discussed for the first time in P. deltoides.

Intra-session repeatability of lower limb muscles activation pattern during pedaling.

PubMed

Dorel, Sylvain; Couturier, Antoine; Hug, François

2008-10-01

Assessment of intra-session repeatability of muscle activation pattern is of considerable relevance for research settings, especially when used to determine changes over time. However, the repeatability of lower limb muscles activation pattern during pedaling is not fully established. Thus, we tested the intra-session repeatability of the activation pattern of 10 lower limb muscles during a sub-maximal cycling exercise. Eleven triathletes participated to this study. The experimental session consisted in a reference sub-maximal cycling exercise (i.e. 150 W) performed before and after a 53-min simulated training session (mean power output=200+/-12 W). Repeatability of EMG patterns was assessed in terms of muscle activity level (i.e. RMS of the mean pedaling cycle and burst) and muscle activation timing (i.e. onset and offset of the EMG burst) for the 10 following lower limb muscles: gluteus maximus (GMax), semimembranosus (SM), Biceps femoris (BF), vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), gastrocnemius medianus (GM) and lateralis (GL), soleus (SOL) and tibialis anterior (TA). No significant differences concerning the muscle activation level were found between test and retest for all the muscles investigated. Only VM, SOL and TA showed significant differences in muscle activation timing parameters. Whereas ICC and SEM values confirmed this weak repeatability, cross-correlation coefficients suggest a good repeatability of the activation timing parameters for all the studied muscles. Overall, the main finding of this work is the good repeatability of the EMG pattern during pedaling both in term of muscle activity level and muscle activation timing.

Sequence repeats and protein structure

NASA Astrophysics Data System (ADS)

Hoang, Trinh X.; Trovato, Antonio; Seno, Flavio; Banavar, Jayanth R.; Maritan, Amos

2012-11-01

Repeats are frequently found in known protein sequences. The level of sequence conservation in tandem repeats correlates with their propensities to be intrinsically disordered. We employ a coarse-grained model of a protein with a two-letter amino acid alphabet, hydrophobic (H) and polar (P), to examine the sequence-structure relationship in the realm of repeated sequences. A fraction of repeated sequences comprises a distinct class of bad folders, whose folding temperatures are much lower than those of random sequences. Imperfection in sequence repetition improves the folding properties of the bad folders while deteriorating those of the good folders. Our results may explain why nature has utilized repeated sequences for their versatility and especially to design functional proteins that are intrinsically unstructured at physiological temperatures.

Using Repeated Reading to Improve Reading Speed and Comprehension in Students with Visual Impairments

ERIC Educational Resources Information Center

Savaiano, Mackenzie E.; Hatton, Deborah D.

2013-01-01

Introduction: This study evaluated whether children with visual impairments who receive repeated reading instruction exhibit an increase in their oral reading rate and comprehension and a decrease in oral reading error rates. Methods: A single-subject, changing-criterion design replicated across three participants was used to demonstrate the…

Repeated partial endoscopic resections as treatment for two patients with inoperable tracheal tumours

PubMed Central

Nakratzas, G.; Wagenaar, J. P. M.; Reintjes, M.; Scheffer, E.; Swierenga, J.

1974-01-01

Nakratzas, G., Wagenaar, J. P. M., Reintjes, M., Scheffer, E., and Swierenga, J. (1974).Thorax, 29, 125-131. Repeated partial endoscopic resections as treatment for two patients with inoperable tracheal tumours. Two cases of tracheal tumour are described, one a carcinoid and the other an adenoid cystic carcinoma (cylindroma). Both patients were treated by repeated partial bronchoscopic resections. The patients are in good health nine and three years respectively after treatment. Images PMID:4363463

Clinical features and genetic diagnosis of hereditary spinocerebellar ataxia 3.

PubMed

Wang, Yaoguang; Yang, Xiaokai; Ma, Weide; Li, Jinxin; Zhang, Qingyuan; Xia, Shuqi; Wang, Hai; Zhang, Chenghui; Xu, Xiaomin; Zheng, Jiayong

2016-10-01

Spinocerebellar ataxia type 3 (SCA3) is a rare inherited autosomal dominant progressive neurological disorder, which results from a CAG‑repeat expansion in the gene encoding the deubiquitinating enzyme, ataxin‑3. At present, no effective treatment is available for this fatal disorder; however, certain studies have suggested that reducing the levels of mutant ataxin‑3 protein may reverse or halt the progression of disease in patients with SCA3. In the present study, clinical examinations were performed on a patient with SCA3 who exhibited disease features including coughing, expectoration and was bedridden with mobility limitation. CAG repetitions at SCA‑associated genes were detected in the patient's family by performing standard polymerase chain reaction (PCR) and triple‑repeat primed PCR. The numbers of CAG‑repeats within the two alleles of the gene of interest in the patient were 15 and 78. Notably, the patient's brother, who harbored 76 CAG‑repeats in one allele of the gene of interest, did not exhibit severe disease symptoms. These results suggest that the number of CAG‑repeats is a critical for determination of SCA3 disease severity and time of onset. In addition, the defined phenotypic characteristics of the patient in the present study provide useful insight for more accurate clinical diagnosis and genotyping of future patients.

Scoring Tools for the Analysis of Infant Respiratory Inductive Plethysmography Signals.

PubMed

Robles-Rubio, Carlos Alejandro; Bertolizio, Gianluca; Brown, Karen A; Kearney, Robert E

2015-01-01

Infants recovering from anesthesia are at risk of life threatening Postoperative Apnea (POA). POA events are rare, and so the study of POA requires the analysis of long cardiorespiratory records. Manual scoring is the preferred method of analysis for these data, but it is limited by low intra- and inter-scorer repeatability. Furthermore, recommended scoring rules do not provide a comprehensive description of the respiratory patterns. This work describes a set of manual scoring tools that address these limitations. These tools include: (i) a set of definitions and scoring rules for 6 mutually exclusive, unique patterns that fully characterize infant respiratory inductive plethysmography (RIP) signals; (ii) RIPScore, a graphical, manual scoring software to apply these rules to infant data; (iii) a library of data segments representing each of the 6 patterns; (iv) a fully automated, interactive formal training protocol to standardize the analysis and establish intra- and inter-scorer repeatability; and (v) a quality control method to monitor scorer ongoing performance over time. To evaluate these tools, three scorers from varied backgrounds were recruited and trained to reach a performance level similar to that of an expert. These scorers used RIPScore to analyze data from infants at risk of POA in two separate, independent instances. Scorers performed with high accuracy and consistency, analyzed data efficiently, had very good intra- and inter-scorer repeatability, and exhibited only minor confusion between patterns. These results indicate that our tools represent an excellent method for the analysis of respiratory patterns in long data records. Although the tools were developed for the study of POA, their use extends to any study of respiratory patterns using RIP (e.g., sleep apnea, extubation readiness). Moreover, by establishing and monitoring scorer repeatability, our tools enable the analysis of large data sets by multiple scorers, which is essential for longitudinal and multicenter studies.

Helical structures in vertically aligned dust particle chains in a complex plasma

NASA Astrophysics Data System (ADS)

Hyde, Truell W.; Kong, Jie; Matthews, Lorin S.

2013-05-01

Self-assembly of structures from vertically aligned, charged dust particle bundles within a glass box placed on the lower, powered electrode of a Gaseous Electronics Conference rf reference cell were produced and examined experimentally. Self-organized formation of one-dimensional vertical chains, two-dimensional zigzag structures, and three-dimensional helical structures of triangular, quadrangular, pentagonal, hexagonal, and heptagonal symmetries are shown to occur. System evolution is shown to progress from a one-dimensional chain structure, through a zigzag transition to a two-dimensional, spindlelike structure, and then to various three-dimensional, helical structures exhibiting multiple symmetries. Stable configurations are found to be dependent upon the system confinement, γ2=ω0h/ω0v2 (where ω0h,v are the horizontal and vertical dust resonance frequencies), the total number of particles within a bundle, and the rf power. For clusters having fixed numbers of particles, the rf power at which structural phase transitions occur is repeatable and exhibits no observable hysteresis. The critical conditions for these structural phase transitions as well as the basic symmetry exhibited by the one-, two-, and three-dimensional structures that subsequently develop are in good agreement with the theoretically predicted configurations of minimum energy determined employing molecular dynamics simulations for charged dust particles confined in a prolate, spheroidal potential as presented theoretically by Kamimura and Ishihara [Kamimura and Ishihara, Phys. Rev. EPLEEE81063-651X10.1103/PhysRevE.85.016406 85, 016406 (2012)].

Reproducibility and repeatability of peripheral microvascular assessment using iontophoresis in conjunction with laser Doppler imaging.

PubMed

Jadhav, Sachin; Sattar, Naveed; Petrie, John R; Cobbe, Stuart M; Ferrell, William R

2007-09-01

Interrogation of peripheral vascular function is increasingly recognized as a noninvasive surrogate marker for coronary vascular function and carries with it important prognostic information regarding future cardiovascular risk. Laser Doppler imaging (LDI) is a completely noninvasive method for looking at peripheral microvascular function. We sought to look at reproducibility and repeatability of LDI-derived assessment of peripheral microvascular function between arms and 8 weeks apart. We used LDI in conjunction with iontophoretic application of ACh and SNP to look at endothelium-dependent and -independent microvascular function, respectively, in a mixture of women with cardiac syndrome X and healthy volunteers. We looked at variation between arms (n = 40) and variation at 8 weeks apart (n = 22). When measurements were corrected for skin resistance, there was nonsignificant variation between arms for ACh (2.7%) and SNP (3.8%) and nonsignificant temporal variation for ACh (3.5%) and SNP (4.7%). Construction of Bland-Altman plots reinforce that measurements have good repeatability. Elimination of the baseline perfusion response had deleterious effects on repeatability. LDI can be used to assess peripheral vascular response with good repeatability as long as measurements are corrected for skin resistance, which affects drug delivery. This has important implications for the future use of LDI.

Beverage Intake Assessment Questionnaire: Relative Validity and Repeatability in a Spanish Population with Metabolic Syndrome from the PREDIMED-PLUS Study.

PubMed

Ferreira-Pêgo, Cíntia; Nissensohn, Mariela; Kavouras, Stavros A; Babio, Nancy; Serra-Majem, Lluís; Martín Águila, Adys; Mauromoustakos, Andy; Álvarez Pérez, Jacqueline; Salas-Salvadó, Jordi

2016-07-30

We assess the repeatability and relative validity of a Spanish beverage intake questionnaire for assessing water intake from beverages. The present analysis was performed within the framework of the PREDIMED-PLUS trial. The study participants were adults (aged 55-75) with a BMI ≥27 and <40 kg/m², and at least three components of Metabolic Syndrome (MetS). A trained dietitian completed the questionnaire. Participants provided 24-h urine samples, and the volume and urine osmolality were recorded. The repeatability of the baseline measurement at 6 and 1 year was examined by paired Student's t-test comparisons. A total of 160 participants were included in the analysis. The Bland-Altman analysis showed relatively good agreement between total daily fluid intake assessed using the fluid-specific questionnaire, and urine osmolality and 24-h volume with parameter estimates of -0.65 and 0.22, respectively (R² = 0.20; p < 0.001). In the repeatability test, no significant differences were found between neither type of beverage nor total daily fluid intake at 6 months and 1-year assessment, compared to baseline. The proposed fluid-specific assessment questionnaire designed to assess the consumption of water and other beverages in Spanish adult individuals was found to be relatively valid with good repeatability.

Assessment of the repeatability and border-plate effects of the B158/B60 enzyme-linked-immunosorbent assay for the detection of circulating antigens (Ag-ELISA) of Taenia saginata.

PubMed

Jansen, Famke; Dorny, Pierre; Berkvens, Dirk; Van Hul, Anke; Van den Broeck, Nick; Makay, Caroline; Praet, Nicolas; Gabriël, Sarah

2016-08-30

The monoclonal antibody-based circulating antigen detecting ELISA (B158/B60 Ag-ELISA) has been used elaborately in several studies for the diagnosis of human, bovine and porcine cysticercosis. Interpretation of test results requires a good knowledge of the test characteristics, including the repeatability and the effect of the borders of the ELISA plates. Repeatability was tested for 4 antigen-negative and 5 antigen-positive reference bovine serum samples by calculating the Percentage Coefficient of Variation (%CV) within and between plates, within and between runs, overall, for two batches of monoclonal antibodies and by 2 laboratory technicians. All CV values obtained were below 20% (except one: 24.45%), which indicates a good repeatability and a negligible technician error. The value of 24.45% for indicating the variability between batches of monoclonal antibodies for one positive sample is still acceptable for repeatability measures. Border effects were determined by calculating the %CV values between the inner and outer wells of one plate for 2 positive serum samples. Variability is a little more present in the outer wells but this effect is very small and no significant border effect was found. Copyright © 2016 Elsevier B.V. All rights reserved.

p57KIP2 expression and loss of heterozygosity during immortal conversion of cultured human mammary epithelial cells

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

Nijjar, Tarlochan; Wigington, Don; Garbe, James C.

1999-08-01

The authors have uncovered a novel role for the cyclin-dependent kinase inhibitor, p57KIP2, during the immortalization of cultured human mammary epithelial cells (HMEC). HMEC immortalized following chemical carcinogen exposure initially expressed little or no telomerase activity, and their telomeres continued to shorten with passage. Cell populations whose mean terminal restriction fragment (TRF) length declined and exhibited slow heterogeneous growth, and contained many non-proliferative cells. These conditionally immortal HMEC cultures accumulated large quantities of p57 protein. With continued passage, the conditionally immortal cell populations very graduall2048nverted to a fully immortal phenotype of good uniform growth, expression of high levels of telomerasemore » activity, and stabilization of telomere length. The fully immortal good growing HMEC did not accumulate p57 in G0 or during the cell cycle. DNA and RNA analysis of mass populations and individual subclones of conditionally immortal HMEC line 184A1 showed that continued growth of conditionally immortal cells with critically short telomeres was repeatedly accompanied by loss of the expressed p57 allele, and transient expression of the previously imprinted allele. Conditionally immortal 184A1 with mean TRF > 3 kb infected with retroviruses containing the p57 gene exhibited premature slow heterogeneous growth. Conversely, exogenous expression of hTERT, the catalytic subunit of telomerase, in 184A1 with mean TRF > 3 kb prevented both the slow heterogeneous growth phase and accumulation of p57 in cycling populations. These data indicate that in HMEC which have overcome replicative senescence, p57 may provide an additional barrier against indefinite proliferation. Overcoming p57 mediated growth inhibition in these cells may be crucial for acquisition of the unlimited growth potential thought to be critical for malignant progression.« less

Separation performance of cucurbit[7]uril in ionic liquid-based sol-gel coating as stationary phase for capillary gas chromatography.

PubMed

Wang, Xiaogang; Qi, Meiling; Fu, Ruonong

2014-12-05

Here we report the separation performance of a new stationary phase of cucurbit[7]uril (CB7) incorporated into an ionic liquid-based sol-gel coating (CB7-SG) for capillary gas chromatography (GC). The CB7-SG stationary phase showed an average polarity of 455, suggesting its polar nature. Abraham system constants revealed that its major interactions with analytes include H-bond basicity (a), dipole-dipole (s) and dispersive (l) interactions. The CB7-SG stationary phase achieved baseline separation for a wide range of analytes with symmetrical peak shapes and showed advantages over the conventional polar stationary phase that failed to resolve some critical analytes. Also, it exhibited different retention behaviors from the conventional stationary phase in terms of retention times and elution order. Most interestingly, in contrast to the conventional polar phase, the CB7-SG stationary phase exhibited longer retentions for analytes of lower polarity but relatively comparable retentions for polar analytes such as alcohols and phenols. The high resolving ability and unique retention behaviors of the CB7-SG stationary phase may stem from the comprehensive interactions of the aforementioned interactions and shape selectivity. Moreover, the CB7-SG column showed good peak shapes for analytes prone to peak tailing, good thermal stability up to 280°C and separation repeatability with RSD values in the range of 0.01-0.11% for intra-day, 0.04-0.41% for inter-day and 2.5-6.0% for column-to-column, respectively. As demonstrated, the proposed coating method can simultaneously address the solubility problem with CBs for the intended purpose and achieve outstanding GC separation performance. Copyright © 2014 Elsevier B.V. All rights reserved.

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

deLorimier, Elaine; Coonrod, Leslie A.; Copperman, Jeremy

In this study, CUG repeat expansions in the 3' UTR of dystrophia myotonica protein kinase ( DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein–RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (Ψ) and 2'-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with Ψ or 2'-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecularmore » dynamics and X-ray crystallography suggest a potential water-bridging mechanism for Ψ-mediated CUG repeat stabilization. Ψ modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases.« less

Concerted evolution of the tandemly repeated genes encoding primate U2 small nuclear RNA (the RNU2 locus) does not prevent rapid diversification of the (CT){sub n} {center_dot} (GA){sub n} microsatellite embedded within the U2 repeat unit

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

Liao, D.; Weiner, A.M.

1995-12-10

The RNU2 locus encoding human U2 small nuclear RNA (snRNA) is organized as a nearly perfect tandem array containing 5 to 22 copies of a 5.8-kb repeat unit. Just downstream of the U2 snRNA gene in each 5.8-kb repeat unit lies a large (CT){sub n}{center_dot}(GA){sub n} dinucleotide repeat (n {approx} 70). This form of genomic organization, in which one repeat is embedded within another, provides an unusual opportunity to study the balance of forces maintaining the homogeneity of both kinds of repeats. Using a combination of field inversion gel electrophoresis and polymerase chain reaction, we have been able to studymore » the CT microsatellites within individual U2 tandem arrays. We find that the CT microsatellites within an RNU2 allele exhibit significant length polymorphism, despite the remarkable homogeneity of the surrounding U2 repeat units. Length polymorphism is due primarily to loss or gain of CT dinucleotide repeats, but other types of deletions, insertions, and substitutions are also frequent. Polymorphism is greatly reduced in regions where pure (CT){sub n} tracts are interrupted by occasional G residues, suggesting that irregularities stabilize both the length and the sequence of the dinucleotide repeat. We further show that the RNU2 loci of other catarrhine primates (gorilla, chimpanzee, ogangutan, and baboon) contain orthologous CT microsatellites; these also exhibit length polymorphism, but are highly divergent from each other. Thus, although the CT microsatellite is evolving far more rapidly than the rest of the U2 repeat unit, it has persisted through multiple speciation events spanning >35 Myr. The persistence of the CT microsatellite, despite polymorphism and rapid evolution, suggests that it might play a functional role in concerted evolution of the RNU2 loci, perhaps as an initiation site for recombination and/or gene conversion. 70 refs., 5 figs.« less

Enhanced super-hydrophobic and switching behavior of ZnO nanostructured surfaces prepared by simple solution--immersion successive ionic layer adsorption and reaction process.

PubMed

Suresh Kumar, P; Sundaramurthy, J; Mangalaraj, D; Nataraj, D; Rajarathnam, D; Srinivasan, M P

2011-11-01

A simple and cost-effective successive ionic layer adsorption and reaction (SILAR) method was adopted to fabricate hydrophobic ZnO nanostructured surfaces on transparent indium-tin oxide (ITO), glass and polyethylene terephthalate (PET) substrates. ZnO films deposited on different substrates show hierarchical structures like spindle, flower and spherical shape with diameters ranging from 30 to 300 nm. The photo-induced switching behaviors of ZnO film surfaces between hydrophobic and hydrophilic states were examined by water contact angle and X-ray photoelectron spectroscopy (XPS) analysis. ZnO nanostructured films had contact angles of ~140° and 160°±2 on glass and PET substrates, respectively, exhibiting hydrophobic behavior without any surface modification or treatment. Upon exposure to ultraviolet (UV) illumination, the films showed hydrophilic behavior (contact angle: 15°±2), which upon low thermal stimuli revert back to its original hydrophobic nature. Such reversible and repeatable switching behaviors were observed upon cyclical exposure to ultraviolet radiation. These biomimetic ZnO surfaces exhibit good anti-reflective properties with lower reflectance of 9% for PET substrates. Thus, the present work is significant in terms of its potential application in switching devices, solar coatings and self-cleaning smart windows. Copyright © 2011 Elsevier Inc. All rights reserved.

Conservative Sample Size Determination for Repeated Measures Analysis of Covariance.

PubMed

Morgan, Timothy M; Case, L Douglas

2013-07-05

In the design of a randomized clinical trial with one pre and multiple post randomized assessments of the outcome variable, one needs to account for the repeated measures in determining the appropriate sample size. Unfortunately, one seldom has a good estimate of the variance of the outcome measure, let alone the correlations among the measurements over time. We show how sample sizes can be calculated by making conservative assumptions regarding the correlations for a variety of covariance structures. The most conservative choice for the correlation depends on the covariance structure and the number of repeated measures. In the absence of good estimates of the correlations, the sample size is often based on a two-sample t-test, making the 'ultra' conservative and unrealistic assumption that there are zero correlations between the baseline and follow-up measures while at the same time assuming there are perfect correlations between the follow-up measures. Compared to the case of taking a single measurement, substantial savings in sample size can be realized by accounting for the repeated measures, even with very conservative assumptions regarding the parameters of the assumed correlation matrix. Assuming compound symmetry, the sample size from the two-sample t-test calculation can be reduced at least 44%, 56%, and 61% for repeated measures analysis of covariance by taking 2, 3, and 4 follow-up measures, respectively. The results offer a rational basis for determining a fairly conservative, yet efficient, sample size for clinical trials with repeated measures and a baseline value.

A randomized comparative study of tolerance and satisfaction in the treatment of actinic keratosis of the face and scalp between 5% imiquimod cream and photodynamic therapy with methyl aminolaevulinate.

PubMed

Serra-Guillen, C; Nagore, E; Hueso, L; Llombart, B; Requena, C; Sanmartín, O; Botella-Estrada, R; Guillen, C

2011-02-01

Photodynamic therapy (PDT) and imiquimod are two excellent treatments for actinic keratosis but are often not well tolerated by patients. To ascertain which treatment is better tolerated and which produces greater patient satisfaction. A secondary objective was to determine the factors related to the patient's tolerance to each treatment. Patients with at least five actinic keratosis lesions on the face and scalp were selected. The patients were randomized to receive treatment with PDT with methyl aminolaevulinate or treatment with imiquimod. Tolerance, satisfaction and predisposition to repeat the treatment were evaluated. Most patients exhibited good or acceptable tolerance to both PDT and imiquimod treatment. There was a higher percentage of patients treated with PDT (93%) who were very satisfied compared with imiquimod (62%) (P=0·004). Most patients treated with either one of the two options would repeat the same treatment. No significant relationship was found between age, sex, working time exposed to the sun, phototype and hair colour and the tolerance to both treatments. Both PDT and imiquimod are treatments that are generally well tolerated. While both treatments provide a high level of satisfaction, PDT appears to be slightly superior in this regard. © 2011 The Authors. BJD © 2011 British Association of Dermatologists.

Corotation of an intermittent solar wind source

NASA Technical Reports Server (NTRS)

Croft, T. A.

1972-01-01

The measured electron content of the solar wind in mid-1970 exhibited a region of relatively high electron density that reappeared at intervals of about 27.8 days. It is shown that the repeating event cannot be reconciled with the concept of a long-enduring steady flow, even though the recurrence period is close to the rotation period of the sun. This evidence of transients is inferred from the short duration of each appearance of the interval of higher density; each should last for roughly one corotation interval if it is caused by a steady stream. The radio path was approximately 0.8 AU long, and the corotation interval exceeded 3 days. Other aspects of the content data patterns support the view that such transient events are common in the solar wind. The mid-1970 repeating event is an unusually good example of the intermittent character of flow regions in the solar wind that fluctuate on a time scale of days but endure as identifiable regions for many months. A sputtering corotating source of thin solar plasma streams could explain this series of events; it could also be explained in terms of a stream that is steady in density and speed but undulating north-south so that it passes into and out of the 0.8 AU radio path in a matter of a day or less.

1200°C high-temperature distributed optical fiber sensing using Brillouin optical time domain analysis.

PubMed

Xu, Pengbai; Dong, Yongkang; Zhou, Dengwang; Fu, Cheng; Zhang, Juwang; Zhang, Hongying; Lu, Zhiwei; Chen, Liang; Bao, Xiaoyi

2016-07-20

In this paper, up to 1100°C and 1200°C high-temperature distributed Brillouin sensing based on a GeO₂-doped single-mode fiber (SMF) and a pure silica photonic crystal fiber (PCF) are demonstrated, respectively. The Brillouin frequency shift's (BFS) dependence on temperatures of the SMF and PCF agrees with a nonlinear function instead of a linear function, which is mainly due to the change of the acoustic velocity in a silica fiber. BFS hopping is observed in both kinds of fibers between 800°C-900°C in the first annealing process, and after that, the BFS exhibits stability and repeatability with a measurement accuracy as high as ±2.4°C for the SMF and ±3.6°C for the PCF. The BFS hopping is a highly temperature-dependent behavior, which means that a high temperature (>800°C) would accelerate this process to reach a stable state. After BFS hopping, both the SMF and PCF show good repeatability for temperatures higher than 1000°C without annealing. The process of coating burning of a silica fiber not only introduces a loss induced by micro-bending, but also imposes a compressive stress on the bare fiber, which contributes to an additional BFS variation at the temperature period of the coating burning (∼300°C-500°C).

Rapid Measurement of Room Temperature Ionic Liquid Electrochemical Gas Sensor using Transient Double Potential Amperometry

PubMed Central

Wan, Hao; Yin, Heyu; Mason, Andrew J.

2016-01-01

Intense study on gas sensors has been conducted to implement fast gas sensing with high sensitivity, reliability and long lifetime. This paper presents a rapid amperometric method for gas sensing based on a room temperature ionic liquid electrochemical gas sensor. To implement a miniaturized sensor with a fast response time, a three electrode system with gold interdigitated electrodes was fabricated by photolithography on a porous polytetrafluoroethylene substrate that greatly enhances gas diffusion. Furthermore, based on the reversible reaction of oxygen, a new transient double potential amperometry (DPA) was explored for electrochemical analysis to decrease the measurement time and reverse reaction by-products that could cause current drift. Parameters in transient DPA including oxidation potential, oxidation period, reduction period and sample point were investigated to study their influence on the performance of the sensor. Oxygen measurement could be accomplished in 4 s, and the sensor presented a sensitivity of 0.2863 μA/[%O2] and a linearity of 0.9943 when tested in air samples with different oxygen concentrations. Repeatability and long-term stability were also investigated, and the sensor was shown to exhibit good reliability. In comparison to conventional constant potential amperometry, transient DPA was shown to reduce relative standard deviation by 63.2%. With transient DPA, the sensitivity, linearity, repeatability, measurement time and current drift characteristics demonstrated by the presented gas sensor are promising for acute exposure applications. PMID:28603384

Rapid Measurement of Room Temperature Ionic Liquid Electrochemical Gas Sensor using Transient Double Potential Amperometry.

PubMed

Wan, Hao; Yin, Heyu; Mason, Andrew J

2017-04-01

Intense study on gas sensors has been conducted to implement fast gas sensing with high sensitivity, reliability and long lifetime. This paper presents a rapid amperometric method for gas sensing based on a room temperature ionic liquid electrochemical gas sensor. To implement a miniaturized sensor with a fast response time, a three electrode system with gold interdigitated electrodes was fabricated by photolithography on a porous polytetrafluoroethylene substrate that greatly enhances gas diffusion. Furthermore, based on the reversible reaction of oxygen, a new transient double potential amperometry (DPA) was explored for electrochemical analysis to decrease the measurement time and reverse reaction by-products that could cause current drift. Parameters in transient DPA including oxidation potential, oxidation period, reduction period and sample point were investigated to study their influence on the performance of the sensor. Oxygen measurement could be accomplished in 4 s, and the sensor presented a sensitivity of 0.2863 μA/[%O 2 ] and a linearity of 0.9943 when tested in air samples with different oxygen concentrations. Repeatability and long-term stability were also investigated, and the sensor was shown to exhibit good reliability. In comparison to conventional constant potential amperometry, transient DPA was shown to reduce relative standard deviation by 63.2%. With transient DPA, the sensitivity, linearity, repeatability, measurement time and current drift characteristics demonstrated by the presented gas sensor are promising for acute exposure applications.

GAA repeat expansion mutation mouse models of Friedreich ataxia exhibit oxidative stress leading to progressive neuronal and cardiac pathology.

PubMed

Al-Mahdawi, Sahar; Pinto, Ricardo Mouro; Varshney, Dhaval; Lawrence, Lorraine; Lowrie, Margaret B; Hughes, Sian; Webster, Zoe; Blake, Julian; Cooper, J Mark; King, Rosalind; Pook, Mark A

2006-11-01

Friedreich ataxia (FRDA) is a neurodegenerative disorder caused by an unstable GAA repeat expansion mutation within intron 1 of the FXN gene. However, the origins of the GAA repeat expansion, its unstable dynamics within different cells and tissues, and its effects on frataxin expression are not yet completely understood. Therefore, we have chosen to generate representative FRDA mouse models by using the human FXN GAA repeat expansion itself as the genetically modified mutation. We have previously reported the establishment of two lines of human FXN YAC transgenic mice that contain unstable GAA repeat expansions within the appropriate genomic context. We now describe the generation of FRDA mouse models by crossbreeding of both lines of human FXN YAC transgenic mice with heterozygous Fxn knockout mice. The resultant FRDA mice that express only human-derived frataxin show comparatively reduced levels of frataxin mRNA and protein expression, decreased aconitase activity, and oxidative stress, leading to progressive neurodegenerative and cardiac pathological phenotypes. Coordination deficits are present, as measured by accelerating rotarod analysis, together with a progressive decrease in locomotor activity and increase in weight. Large vacuoles are detected within neurons of the dorsal root ganglia (DRG), predominantly within the lumbar regions in 6-month-old mice, but spreading to the cervical regions after 1 year of age. Secondary demyelination of large axons is also detected within the lumbar roots of older mice. Lipofuscin deposition is increased in both DRG neurons and cardiomyocytes, and iron deposition is detected in cardiomyocytes after 1 year of age. These mice represent the first GAA repeat expansion-based FRDA mouse models that exhibit progressive FRDA-like pathology and thus will be of use in testing potential therapeutic strategies, particularly GAA repeat-based strategies.

Layer-by-Layer Self-Assembling Gold Nanorods and Glucose Oxidase onto Carbon Nanotubes Functionalized Sol-Gel Matrix for an Amperometric Glucose Biosensor

PubMed Central

Wu, Baoyan; Hou, Shihua; Miao, Zhiying; Zhang, Cong; Ji, Yanhong

2015-01-01

A novel amperometric glucose biosensor was fabricated by layer-by-layer self-assembly of gold nanorods (AuNRs) and glucose oxidase (GOD) onto single-walled carbon nanotubes (SWCNTs)-functionalized three-dimensional sol-gel matrix. A thiolated aqueous silica sol containing SWCNTs was first assembled on the surface of a cleaned Au electrode, and then the alternate self-assembly of AuNRs and GOD were repeated to assemble multilayer films of AuNRs-GOD onto SWCNTs-functionalized silica gel for optimizing the biosensor. Among the resulting glucose biosensors, the four layers of AuNRs-GOD-modified electrode showed the best performance. The sol-SWCNTs-(AuNRs-GOD)4/Au biosensor exhibited a good linear range of 0.01–8 mM glucose, high sensitivity of 1.08 μA/mM, and fast amperometric response within 4 s. The good performance of the proposed glucose biosensor could be mainly attributed to the advantages of the three-dimensional sol-gel matrix and stereo self-assembly films, and the natural features of one-dimensional nanostructure SWCNTs and AuNRs. This study may provide a new facile way to fabricate the enzyme-based biosensor with high performance. PMID:28347080

One size (never) fits all: segment differences observed following a school-based alcohol social marketing program.

PubMed

Dietrich, Timo; Rundle-Thiele, Sharyn; Leo, Cheryl; Connor, Jason

2015-04-01

According to commercial marketing theory, a market orientation leads to improved performance. Drawing on the social marketing principles of segmentation and audience research, the current study seeks to identify segments to examine responses to a school-based alcohol social marketing program. A sample of 371 year 10 students (aged: 14-16 years; 51.4% boys) participated in a prospective (pre-post) multisite alcohol social marketing program. Game On: Know Alcohol (GO:KA) program included 6, student-centered, and interactive lessons to teach adolescents about alcohol and strategies to abstain or moderate drinking. A repeated measures design was used. Baseline demographics, drinking attitudes, drinking intentions, and alcohol knowledge were cluster analyzed to identify segments. Change on key program outcome measures and satisfaction with program components were assessed by segment. Three segments were identified; (1) Skeptics, (2) Risky Males, (3) Good Females. Segments 2 and 3 showed greatest change in drinking attitudes and intentions. Good Females reported highest satisfaction with all program components and Skeptics lowest program satisfaction with all program components. Three segments, each differing on psychographic and demographic variables, exhibited different change patterns following participation in GO:KA. Post hoc analysis identified that satisfaction with program components differed by segment offering opportunities for further research. © 2015, American School Health Association.

Non-enzymatic glucose sensor based on electrodeposited copper on carbon paste electrode (Cu/CPE)

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

Nurani, Dita Arifa, E-mail: d.arifa@sci.ui.ac.id; Wibowo, Rahmat; Fajri, Iqbal Farhan El

The development of non-enzymatic glucose sensor has much attention due to their applications in glucose monitoring. In this research, copper oxide is used as a non-enzymatic glucose sensor by oxidizing glucose to gluconolactone. Copper was electrodeposited on Carbon paste electrode (CPE) at constant potential. The experimental condition was varied in electrodeposition of Cu with the following parameters: Electrodeposition time 60 s, 120 s and 180 s and potential reduction -0.166 V, -0.266 V and -0.366 V. The effective performance of these working electrodes in sensing glucose was investigated. The Cu/CPE which used -0.366 V potential reduction and 120 s electrodeposition time shows the bestmore » performance. The amperometric response current in concentration range 1.6-62.5 mM of glucose gives the good linearity R{sup 2} = 0.9988, low detection limit 0.6728 mM and high sensitivity 1183.59 µA mM{sup −1}cm{sup −2}. Furthermore this sensor exhibited a good repeatability with %RSD = 1.31% (n=10) and high stability with %RSD = 1.51% (n=5 days). The homogeneity of Cu particles on CPE was investigated by Scanning Electron Microscope (SEM).« less

Graphene oxide decorated with silver nanoparticles as a coating on a stainless-steel fiber for solid-phase microextraction.

PubMed

Wang, Licheng; Hou, Xiudan; Li, Jubai; Liu, Shujuan; Guo, Yong

2015-07-01

A novel graphene oxide decorated with silver nanoparticles coating on a stainless-steel fiber for solid-phase microextraction was prepared. Scanning electron microscopy and X-ray photoelectron spectroscopy were used to characterize the coating surface and showed that silver nanoparticles were dispersed on the wrinkled graphene oxide surface. Coupled to gas chromatography with flame ionization detection, the extraction abilities of the fiber for polycyclic aromatic hydrocarbons were examined in the headspace solid-phase microextraction mode. The extraction parameters including adsorption time, adsorption temperature, salt concentration, desorption time and desorption temperature were investigated. Under the optimized condition, wide linearity with low limits of detection from 2 to 10 ng/L was obtained. The relative standard deviations for single-fiber repeatability and fiber-to-fiber reproducibility were less than 10.6 and 17.5%, respectively. The enrichment factors were from 1712.5 to 4503.7, showing the fiber has good extraction abilities. Moreover, the fiber exhibited a good stability and could be reused for more than 120 times. The established method was also applied for determination of polycyclic aromatic hydrocarbons in two real water samples and the recoveries of analytes ranged from 84.4-116.3% with relative standard deviations less than 16.2%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel electrochemical immunosensor based on ITO modified by carboxyl-ended silane agent for ultrasensitive detection of MAGE-1 in human serum.

PubMed

Gündoğdu, Aslı; Aydın, Elif Burcu; Sezgintürk, Mustafa Kemal

2017-11-15

A new, low-cost electrochemical immunosensor was developed for rapid detection of Melanoma-associated antigen 1 (MAGE-1), a cancer biomarker. The fabrication procedure of immunosensor was based on the covalent immobilization of anti-MAGE-1, biorecognition molecule, on ITO electrode by carboxyethylsilanetriol (CTES) monolayer. The biosensing MAGE-1 antigen was monitored by using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) technique. Apart from these techniques, single frequency impedance (SFI) was used for investigation of antibody-antigen interactions. Scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) were utilized for characterization of the proposed biosensor. To fabricate highly sensitive, good stability immunosensor, some parameters were optimized. Under optimal conditions, the developed electrochemical immunosensor for MAGE-1 exhibited a dynamic range of 4 fg/mL and 200 fg/mL with a low detection limit of 1.30 fg/mL. It had acceptable repeatability (5.05%, n = 20) and good storage stability (3.58% loss after 10 weeks). Moreover, this electrochemical immunosensor has been successfully applied to the determination of MAGE-1 in human serum samples. Copyright © 2017 Elsevier Inc. All rights reserved.

40 CFR 1065.526 - Repeating void modes or test intervals.

Code of Federal Regulations, 2011 CFR

2011-07-01

... or test intervals in any circumstances that would be inconsistent with good engineering judgment. For... that include hybrid energy storage features or emission controls that involve physical or chemical... shut down, restart the engine. (2) Use good engineering judgment to restart the test sequence using the...

40 CFR 1065.526 - Repeating of void modes or test intervals.

Code of Federal Regulations, 2014 CFR

2014-07-01

... or test intervals in any circumstances that would be inconsistent with good engineering judgment. For... that include hybrid energy storage features or emission controls that involve physical or chemical... follows: (1) If the engine has stalled or been shut down, restart the engine. (2) Use good engineering...

40 CFR 1065.526 - Repeating void modes or test intervals.

Code of Federal Regulations, 2012 CFR

2012-07-01

... or test intervals in any circumstances that would be inconsistent with good engineering judgment. For... that include hybrid energy storage features or emission controls that involve physical or chemical... shut down, restart the engine. (2) Use good engineering judgment to restart the test sequence using the...

Semiconducting compounds and devices incorporating same

DOEpatents

Marks, Tobin J; Facchetti, Antonio; Boudreault, Pierre-Luc; Miyauchi, Hiroyuki

2014-06-17

Disclosed are molecular and polymeric compounds having desirable properties as semiconducting materials. Such compounds can exhibit desirable electronic properties and possess processing advantages including solution-processability and/or good stability. Organic transistor and photovoltaic devices incorporating the present compounds as the active layer exhibit good device performance.

Semiconducting compounds and devices incorporating same

DOEpatents

Marks, Tobin J.; Facchetti, Antonio; Boudreault, Pierre-Luc; Miyauchi, Hiroyuki

2016-01-19

Disclosed are molecular and polymeric compounds having desirable properties as semiconducting materials. Such compounds can exhibit desirable electronic properties and possess processing advantages including solution-processability and/or good stability. Organic transistor and photovoltaic devices incorporating the present compounds as the active layer exhibit good device performance.

Analysis of pelvic rotation on the standard hip ventrodorsal extended radiographic view.

PubMed

Martins, João; Colaço, Bruno J; Ferreira, António J; Ginja, Mário M

2016-01-01

To study the symmetry of the iliac horizontal diameter (IHD) maximum obturator foramen width (OFW), ischiatic femoral overlap (IFO), pelvic horizontal radius (PHR), femoral head diameter (FHD), and obturator foramen area (OFA) parameters in the normal hip extended radiographic view and to evaluate the correlation of pelvic rotation with the magnitude of asymmetry of these parameters. Nine canine cadavers from adult, large and giant breeds were radiographed in standard hip extended views and with 2°, 4° and 6° degrees of rotation. The variables IHD, OFW, IFO, PHR, FHD, and OFA were analysed in radiographs. The IHD measurements exhibited repeatability, bilateral symmetry and 95% of confidence interval of asymmetry in different pelvic rotations without superposition (p <0.05); OFW and IFO exhibited repeatability, bilateral symmetry and a small superposition in 95% of confidence interval of asymmetry according different pelvic rotations; PHR, FHD and OFA exhibited repeatability, bilateral symmetry and unacceptable superposition in 95% of confidence interval of asymmetry depending on pelvic rotation. The IHD is the recommended variable and OFW is an acceptable variable in order to evaluate slight pelvic rotation. The data may be used in qualitative analyses of hip extended radiographic views. In the future, complementary studies should be performed to evaluate the impact of degree of pelvic rotation on the hip dysplasia score.

Evolution of All-or-None Strategies in Repeated Public Goods Dilemmas

PubMed Central

2014-01-01

Many problems of cooperation involve repeated interactions among the same groups of individuals. When collective action is at stake, groups often engage in Public Goods Games (PGG), where individuals contribute (or not) to a common pool, subsequently sharing the resources. Such scenarios of repeated group interactions materialize situations in which direct reciprocation to groups may be at work. Here we study direct group reciprocity considering the complete set of reactive strategies, where individuals behave conditionally on what they observed in the previous round. We study both analytically and by computer simulations the evolutionary dynamics encompassing this extensive strategy space, witnessing the emergence of a surprisingly simple strategy that we call All-Or-None (AoN). AoN consists in cooperating only after a round of unanimous group behavior (cooperation or defection), and proves robust in the presence of errors, thus fostering cooperation in a wide range of group sizes. The principles encapsulated in this strategy share a level of complexity reminiscent of that found already in 2-person games under direct and indirect reciprocity, reducing, in fact, to the well-known Win-Stay-Lose-Shift strategy in the limit of the repeated 2-person Prisoner's Dilemma. PMID:25393661

Repeatability and reproducibility of measurements of the suburethral tape location obtained in pelvic floor ultrasound performed with a transvaginal probe

PubMed Central

Dresler, Maria Magdalena; Kociszewski, Jacek; Pędraszewski, Piotr; Trzeciak, Agnieszka; Surkont, Grzegorz

2017-01-01

Introduction Implants used to treat patients with urogynecological conditions are well visible in US examination. The position of the suburethral tape (sling) is determined in relation to the urethra or the pubic symphysis. Aim of the study The study was aimed at assessing the accuracy of measurements determining suburethral tape location obtained in pelvic US examination performed with a transvaginal probe. Material and methods The analysis covered the results of sonographic measurements obtained according to a standardized technique in women referred for urogynecological diagnostics. Data from a total of 68 patients were used to analyse the repeatability and reproducibility of results obtained on the same day. Results The intraclass correlation coefficient for the repeatability and reproducibility of the sonographic measurements of suburethral tape location obtained with a transvaginal probe ranged from 0.6665 to 0.9911. The analysis of the measurements confirmed their consistency to be excellent or good. Conclusions Excellent and good repeatability and reproducibility of the measurements of the suburethral tape location obtained in a pelvic ultrasound performed with a transvaginal probe confirm the test’s validity and usefulness for clinical and academic purposes. PMID:28856017

Orexins Mediate Sex Differences in the Stress Response and in Cognitive Flexibility.

PubMed

Grafe, Laura A; Cornfeld, Amanda; Luz, Sandra; Valentino, Rita; Bhatnagar, Seema

2017-04-15

Women are twice as likely as men to experience stress-related psychiatric disorders. The biological basis of these sex differences is poorly understood. Orexins are altered in anxious and depressed patients. Using a rat model of repeated stress, we examined whether orexins contribute to sex differences in outcomes relevant to stress-related psychiatric diseases. Behavioral, neural, and endocrine habituation to repeated restraint stress and subsequent cognitive flexibility was examined in adult male and female rats. In parallel, orexin expression and activation were determined in both sexes, and chromatin immunoprecipitation was used to determine transcription factors acting at the orexin promoter. Designer receptors exclusively activated by designer drugs were used to inhibit orexin activation throughout repeated restraint to determine if the stress-related impairments in female rats could be reduced. Female rats exhibited impaired habituation to repeated restraint with subsequent deficits in cognitive flexibility compared with male rats. Increased orexin expression and activation were observed in female rats compared with male rats. The higher expression of orexin messenger RNA in female rats was due to actions of glucocorticoid receptors on the orexin promoter, as determined by chromatin immunoprecipitation. Inhibition of orexins using designer receptors exclusively activated by designer drugs in female rats throughout repeated restraint abolished their heightened hypothalamic-pituitary-adrenal responsivity and reduced stress-induced cognitive impairments. Orexins mediate the impairments in adaptations to repeated stress and in subsequent cognitive flexibility exhibited by female rats and provide evidence for a broader role for orexins in mediating functions relevant to stress-related psychiatric diseases. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Repeating Patterns and Multiplicative Thinking: Analysis of Classroom Interactions with 9-Year-Old Students that Support the Transition from the Known to the Novel

ERIC Educational Resources Information Center

Warren, Elizabeth; Cooper, Tom

2007-01-01

In early years' (primary grade) classrooms in Australia repeated patterns are commonly explored as an early introductory activity to mathematics. Most young students have an extensive knowledge of and exhibit success in copying, continuing, creating and transferring patterns into other media. By contrast, research indicates one of the most…

Beverage Intake Assessment Questionnaire: Relative Validity and Repeatability in a Spanish Population with Metabolic Syndrome from the PREDIMED-PLUS Study

PubMed Central

Ferreira-Pêgo, Cíntia; Nissensohn, Mariela; Kavouras, Stavros A.; Babio, Nancy; Serra-Majem, Lluís; Martín Águila, Adys; Mauromoustakos, Andy; Álvarez Pérez, Jacqueline; Salas-Salvadó, Jordi

2016-01-01

We assess the repeatability and relative validity of a Spanish beverage intake questionnaire for assessing water intake from beverages. The present analysis was performed within the framework of the PREDIMED-PLUS trial. The study participants were adults (aged 55–75) with a BMI ≥27 and <40 kg/m2, and at least three components of Metabolic Syndrome (MetS). A trained dietitian completed the questionnaire. Participants provided 24-h urine samples, and the volume and urine osmolality were recorded. The repeatability of the baseline measurement at 6 and 1 year was examined by paired Student’s t-test comparisons. A total of 160 participants were included in the analysis. The Bland–Altman analysis showed relatively good agreement between total daily fluid intake assessed using the fluid-specific questionnaire, and urine osmolality and 24-h volume with parameter estimates of −0.65 and 0.22, respectively (R2 = 0.20; p < 0.001). In the repeatability test, no significant differences were found between neither type of beverage nor total daily fluid intake at 6 months and 1-year assessment, compared to baseline. The proposed fluid-specific assessment questionnaire designed to assess the consumption of water and other beverages in Spanish adult individuals was found to be relatively valid with good repeatability. PMID:27483318

Molecular weight distribution of polysaccharides from edible seaweeds by high-performance size-exclusion chromatography (HPSEC).

PubMed

Gómez-Ordóñez, Eva; Jiménez-Escrig, Antonio; Rupérez, Pilar

2012-05-15

Biological properties of polysaccharides from seaweeds are related to their composition and structure. Many factors such as the kind of sugar, type of linkage or sulfate content of algal biopolymers exert an influence in the relationship between structure and function. Besides, the molecular weight (MW) also plays an important role. Thus, a simple, reliable and fast HPSEC method with refractive index detection was developed and optimized for the MW estimation of soluble algal polysaccharides. Chromatogram shape and repeatability of retention time was considerably improved when sodium nitrate was used instead of ultrapure water as mobile phase. Pullulan and dextran standards of different MW were used for method calibration and validation. Also, main polysaccharide standards from brown (alginate, fucoidan, laminaran) and red seaweeds (kappa- and iota-carrageenan) were used for quantification and method precision and accuracy. Relative standard deviation (RSD) of repeatability for retention time, peak areas and inter-day precision was below 0.7%, 2.5% and 2.6%, respectively, which indicated good repeatability and precision. Recoveries (96.3-109.8%) also showed its fairly good accuracy. Regarding linearity, main polysaccharide standards from brown or red seaweeds showed a highly satisfactory correlation coefficient (r>0.999). Moreover, a good sensitivity was shown, with corresponding limits of detection and quantitation in mg/mL of 0.05-0.21 and 0.16-0.31, respectively. The method was applied to the MW estimation of standard algal polysaccharides, as well as to the soluble polysaccharide fractions from the brown seaweed Saccharina latissima and the red Mastocarpus stellatus, respectively. Although distribution of molecular weight was broad, the good repeatability for retention time provided a good precision in MW estimation of polysaccharides. Water- and alkali-soluble fractions from S. latissima ranged from very high (>2400 kDa) to low MW compounds (<6 kDa); this high heterogeneity could be attributable to the complex polysaccharide composition of brown algae. Regarding M. stellatus, sulfated galactans followed a descending order of MW (>1400 kDa to <10 kDa), related to the different solubility of carrageenans in red seaweeds. In summary, the method developed allows for the molecular weight analysis of seaweed polysaccharides with very good precision, accuracy, linearity and sensitivity within a short time. Copyright © 2012 Elsevier B.V. All rights reserved.

Repeatability of Cryogenic Multilayer Insulation

NASA Technical Reports Server (NTRS)

Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

2017-01-01

Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between multiple identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five GRC provided coupons with 25 layers was shown to be +/- 8.4 whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0. A second group of 10 coupons have been fabricated by Yetispace and tested by Florida State University, through the first 4 tests, the repeatability has been shown to be +/- 16. Based on detailed statistical analysis, the data has been shown to be statistically significant.

Repeatability of Cryogenic Multilayer Insulation

NASA Technical Reports Server (NTRS)

Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

2017-01-01

Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between multiple identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five GRC provided coupons with 25 layers was shown to be +/- 8.4% whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0%. A second group of 10 coupons have been fabricated by Yetispace and tested by Florida State University, through the first 4 tests, the repeatability has been shown to be +/- 15-25%. Based on detailed statistical analysis, the data has been shown to be statistically significant.

Repeatability of Cryogenic Multilayer Insulation

NASA Astrophysics Data System (ADS)

Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

2017-12-01

Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation (MLI) has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five Glenn Research Center (GRC) provided coupons with 25 layers was shown to be +/- 8.4% whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0%. A second group of 10 coupons has been fabricated by Yetispace and tested by Florida State University, the repeatability between coupons has been shown to be +/- 15-25%. Based on detailed statistical analysis, the data has been shown to be statistically significant.

The incidence of anticipatory nausea and vomiting after repeat cycle chemotherapy: the effect of granisetron.

PubMed Central

Aapro, M. S.; Kirchner, V.; Terrey, J. P.

1994-01-01

Anticipatory nausea and vomiting (ANV) after repeated cycles of cytotoxic chemotherapy is thought to be a conditioned response to a conditioning stimulus. Good control of acute and delayed emesis may result in a lower incidence of ANV. We have analysed data from 574 chemotherapy patients who received granisetron as their antiemetic treatment during repeat cycle chemotherapy. Per treatment cycle, less than 10% of patients displayed symptoms of anticipatory nausea and 2% or less had symptoms of anticipatory vomiting. It is concluded that the use of granisetron as an antiemetic during the acute phase of chemotherapy may result in a lower incidence of ANV in patients undergoing repeat cycle chemotherapy. PMID:8180031

Modifications to toxic CUG RNAs induce structural stability, rescue mis-splicing in a myotonic dystrophy cell model and reduce toxicity in a myotonic dystrophy zebrafish model

DOE PAGES

deLorimier, Elaine; Coonrod, Leslie A.; Copperman, Jeremy; ...

2014-10-10

In this study, CUG repeat expansions in the 3' UTR of dystrophia myotonica protein kinase ( DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein–RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (Ψ) and 2'-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with Ψ or 2'-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecularmore » dynamics and X-ray crystallography suggest a potential water-bridging mechanism for Ψ-mediated CUG repeat stabilization. Ψ modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases.« less

Competitive Bidding in a Certain Class of Auctions

NASA Astrophysics Data System (ADS)

Johansson, Mathias

2006-11-01

We consider the problem of determining the amount to bid in a certain type of auctions in which customers submit one sealed bid. The bid reflects the price a customer is willing to pay for one unit of the offered goods. The auction is repeated and at each auction each customer requests a certain amount of goods, an amount that we call the capacity of the customer and that varies among customers and over time. At each auction, only the customer with the largest bid-capacity product obtains any goods. The price paid by the winner equals his/her bid-capacity product, and the amount of goods obtained in return equals the winner's capacity. The auction is repeated many times, with only limited information concerning winning bid-capacity products being announced to the customers. This situation is motivated in for example wireless communication networks in which a possible way of obtaining a desired service level is to use dynamic pricing and competitive bidding. In this application, the capacity is typically uncertain when the bid is made. We derive bidding rules and loss functions for a few typical service requirements.

The Future of Drought in the Southeastern U.S.: Projections from downscaled CMIP5 models

NASA Astrophysics Data System (ADS)

Keellings, D.; Engstrom, J.

2017-12-01

The Southeastern U.S. has been repeatedly impacted by severe droughts that have affected the environment and economy of the region. In this study the ability of 32 downscaled CMIP5 models, bias corrected using localized constructed analogs (LOCA), to simulate historical observations of dry spells from 1950-2005 are assessed using Perkins skill scores and significance tests. The models generally simulate the distribution of dry days well but there are significant differences between the ability of the best and worst performing models, particularly when it comes to the upper tail of the distribution. The best and worst performing models are then projected through 2099, using RCP 4.5 and 8.5, and estimates of 20 year return periods are compared. Only the higher skill models provide a good estimate of extreme dry spell lengths with simulations of 20 year return values within ± 5 days of observed values across the region. Projected return values differ by model grouping, but all models exhibit significant increases.

A bifunctional amorphous polymer exhibiting equal linear and circular photoinduced birefringences.

PubMed

Royes, Jorge; Provenzano, Clementina; Pagliusi, Pasquale; Tejedor, Rosa M; Piñol, Milagros; Oriol, Luis

2014-11-01

The large and reversible photoinduced linear and circular birefringences in azo-compounds are at the basis of the interest in these materials, which are potentially useful for several applications. Since the onset of the linear and circular anisotropies relies on orientational processes, which typically occur on the molecular and supramolecular length scale, respectively, a circular birefringence at least one order of magnitude lower than the linear one is usually observed. Here, the synthesis and characterization of an amorphous polymer with a dimeric repeating unit containing a cyanoazobenzene and a cyanobiphenyl moiety are reported, in which identical optical linear and circular birefringences are induced for proper light dose and ellipticity. A pump-probe technique and an analytical method based on the Stokes-Mueller formalism are used to investigate the photoinduced effects and to evaluate the anisotropies. The peculiar photoresponse of the polymer makes it a good candidate for applications in smart functional devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of graphene oxide/lanthanum-modified carbon paste electrode for the selective determination of dopamine

NASA Astrophysics Data System (ADS)

Ye, Fengying; Feng, Chenqi; Fu, Ning; Wu, Huihui; Jiang, Jibo; Han, Sheng

2015-12-01

A home-made carbon paste electrode (CPE) was reformed by graphene oxide (GO)/lanthanum (La) complexes, and a modified electrode, called GO-La/CPE, was fabricated for the selective determination of dopamine (DA) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Several factors affecting the electrocatalytic performance of the modified sensor were investigated. Owning to the combination of GO and La ions, the GO-La/CPE sensor exhibited large surface area, well selectivity, good repeatability and stability in the oxidation reaction of DA. At optimal conditions, the response of the GO-La/CPE electrode for determining DA was linear in the region of 0.01-0.1 μM and 0.1-400.0 μM. The limit of detection was down to 0.32 nM (S/N = 3). In addition, this modified electrode was successfully applied to the detection of DA in real urine and serum samples by using standard adding method, showing its promising application in the electroanalysis of real samples.

On hydrophilicity improvement of the porous anodic alumina film by hybrid nano/micro structuring

NASA Astrophysics Data System (ADS)

Wang, Weichao; Zhao, Wei; Wang, Kaige; Wang, Lei; Wang, Xuewen; Wang, Shuang; Zhang, Chen; Bai, Jintao

2017-09-01

In both, laboratory and industry, tremendous attention is paid to discover an effective technique to produce uniform, controllable and (super) hydrophilic surfaces over large areas that are useful in a wide range of applications. In this investigation, by combing porous anodic alumina (PAA) film with nano-structures and microarray of aluminum, the hydrophilicity of hybrid nano-micro structure has been significantly improved. It is found some factors can affect the hydrophilicity of film, such as the size and aspect ratio of microarray, the thickness of nano-PAA film etc. Comparing with pure nano-PAA films and microarray, the hybrid nano-micro structure can provide uniform surface with significantly better hydrophilicity. The improvement can be up to 84%. Also, this technique exhibits good stability and repeatability for industrial production. By optimizing the thickness of nano-PAA film and aspect ratio of micro-structures, super-hydrophilicity can be reached. This study has obvious prospect in the fields of chemical industry, biomedical engineering and lab-on-a-chip applications.

Detection of glycoprotein using fiber optic surface plasmon resonance sensors with boronic acid

NASA Astrophysics Data System (ADS)

Wang, Fang; Zhang, Yang; Liu, Zigeng; Qian, Siyu; Gu, Yiying; Jing, Zhenguo; Sun, Changsen; Peng, Wei

2017-04-01

In this paper, we present a tilted fiber Bragg gratings (TFBG) based surface Plasmon resonance (SPR) label-free sensors with boronic acid derivative (ABA-PBA) as receptor molecule to detect glycoprotein with high sensitivity and selectivity. Tilted fiber Bragg gratings (TFBG) as a near infrared wavelengths detecting element can be able to excite a number of cladding modes whose properties can be detected accurately by measuring the variation of transmitted spectra. A 10° TFBG coated by 50nm gold film was manufactured to stimulate surface plasmon resonance on the surface of the sensor. The sensor was loaded with boronic acid derivative as the recognition molecule which has been widely used in various areas for the recognition matrix of diol-containing biomolecules. The proposed TFBG-SPR sensors exhibit good selectivity and repeatability with the protein concentration sensitivity up to 2.867dB/ (mg/ml) and the limit of detection was 2*10-5g/ml.

Noncontact, Electrode-free Capacitance/Voltage Measurement Based on General Theory of Metal-Oxide-Semiconductor (MOS) Structure

NASA Astrophysics Data System (ADS)

Sakai, Takamasa; Kohno, Motohiro; Hirae, Sadao; Nakatani, Ikuyoshi; Kusuda, Tatsufumi

1993-09-01

In this paper, we discussed a novel approach to semiconductor surface inspection, which is analysis using the C--V curve measured in a noncontact method by the metal-air-semiconductor (MAIS) technique. A new gap sensing method using the so-called Goos-Haenchen effect was developed to achieve the noncontact C--V measurement. The MAIS technique exhibited comparable sensitivity and repeatability to those of conventional C--V measurement, and hence, good reproducibility and resolution for quantifying the electrically active impurity on the order of 1× 109/cm2, which is better than most spectrometric techniques, such as secondary ion mass spectroscopy (SIMS), electron spectroscopy for chemical analysis (ESCA) and Auger electron spectrocopy (AES) which are time-consuming and destructive. This measurement without preparation of any electrical contact metal electrode suggested, for the first time, the possibility of measuring an intrinsic characteristic of the semiconductor surface, using the examples of a concrete examination.

Improved switching reliability achieved in HfOx based RRAM with mountain-like surface-graphited carbon layer

NASA Astrophysics Data System (ADS)

Tao, Ye; Ding, Wentao; Wang, Zhongqiang; Xu, Haiyang; Zhao, Xiaoning; Li, Xuhong; Liu, Weizhen; Ma, Jiangang; Liu, Yichun

2018-05-01

In this work, we demonstrated an effective method to improve the switching reliability of HfOx based RRAM device by inserting mountain-like surface-graphited carbon (MSGC) layer. The MSGC layer was fabricated through thermal annealing of amorphous carbon (a-C) film with high sp2 proportion (49.7%) under 500 °C on Pt substrate, whose characteristics were validated by XPS and Raman spectrums. The local electric-field (LEF) was enhanced around the nanoscale tips of MSGC layer due to large surface curvature, which leads to simplified CFs and localization of resistive switching region. It takes responsibility to the reduction of high/low resistance states (HRS/LRS) fluctuation from 173.8%/64.9% to 23.6%/6.5%, respectively. In addition, the resulting RRAM devices exhibited fast switching speed (<65 ns), good retention (>104 s at 85 °C) and low cycling degradation. This method could be promising to develop reliable and repeatable high-performance RRAM for practical applications.

SPR imaging based electronic tongue via landscape images for complex mixture analysis.

PubMed

Genua, Maria; Garçon, Laurie-Amandine; Mounier, Violette; Wehry, Hillary; Buhot, Arnaud; Billon, Martial; Calemczuk, Roberto; Bonnaffé, David; Hou, Yanxia; Livache, Thierry

2014-12-01

Electronic noses/tongues (eN/eT) have emerged as promising alternatives for analysis of complex mixtures in the domain of food and beverage quality control. We have recently developed an electronic tongue by combining surface plasmon resonance imaging (SPRi) with an array of non-specific and cross-reactive receptors prepared by simply mixing two small molecules in varying and controlled proportions and allowing the mixtures to self-assemble on the SPRi prism surface. The obtained eT generated novel and unique 2D continuous evolution profiles (CEPs) and 3D continuous evolution landscapes (CELs) based on which the differentiation of complex mixtures such as red wine, beer and milk were successful. The preliminary experiments performed for monitoring the deterioration of UHT milk demonstrated its potential for quality control applications. Furthermore, the eT exhibited good repeatability and stability, capable of operating after a minimum storage period of 5 months. Copyright © 2014 Elsevier B.V. All rights reserved.

Life-Cycle Traits of Paraleucilla magna, a Calcareous Sponge Invasive in a Coastal Mediterranean Basin

PubMed Central

Longo, Caterina; Pontassuglia, Carmen; Corriero, Giuseppe; Gaino, Elda

2012-01-01

The calcareous sponge Paraleucilla magna, originally observed along the Brazilian coast (Atlantic Ocean), is the only allochthonous invasive species of Porifera reported in the Mediterranean Sea. A 1-year investigation of the population dynamics and life-cycle of this exotic species in the Mar Piccolo di Taranto (southern Italy, central Mediterranean Sea) has provided a good opportunity to test how environmental variations can influence its life-cycle and to ascertain what strategy can be adopted to successfully colonize a new environment. In the Mar Piccolo di Taranto, P. magna exhibits marked temporal changes in biomass. The studied specimens reproduce almost all year round, showing a seasonal pattern that peaks during warm months. This prolonged sexual activity allows P. magna to continuously produce young specimens, with repeated recruitment events taking place throughout the year, thus offsetting the seasonal mortality of adult specimens. This r-strategy enables the non-indigenous sponge to achieve a high degree of maintenance over relatively long periods (ten years at least). PMID:22905128

Charge modeling of ionic polymer-metal composites for dynamic curvature sensing

NASA Astrophysics Data System (ADS)

Bahramzadeh, Yousef; Shahinpoor, Mohsen

2011-04-01

A curvature sensor based on Ionic Polymer-Metal Composite (IPMC) is proposed and characterized for sensing of curvature variation in structures such as inflatable space structures in which using low power and flexible curvature sensor is of high importance for dynamic monitoring of shape at desired points. The linearity of output signal of sensor for calibration, effect of deflection rate at low frequencies and the phase delay between the output signal and the input deformation of IPMC curvature sensor is investigated. An analytical chemo-electro-mechanical model for charge dynamic of IPMC sensor is presented based on Nernst-Planck partial differential equation which can be used to explain the phenomena observed in experiments. The rate dependency of output signal and phase delay between the applied deformation and sensor signal is studied using the proposed model. The model provides a background for predicting the general characteristics of IPMC sensor. It is shown that IPMC sensor exhibits good linearity, sensitivity, and repeatability for dynamic curvature sensing of inflatable structures.

A Novel Nanofilm Sensor Based on Poly-(Alizarin Red)/Fe3O4 Magnetic Nanoparticles-Multiwalled Carbon Nanotubes Composite Material for Determination of Nitrite.

PubMed

Qu, Jianying; Dong, Ying; Yong, Wang; Lou, Tongfang; Du, Xueping; Qu, Jianhang

2016-03-01

Fe3O4 magnetic nanoparticles were synthesized by chemical co-precipitation with sodium citrate as surfactant and were characterized by FT-IR spectrometer, X-ray diffraction and transmission electron microscopy. A novel nitrite sensor was fabricated by electropolymerization of alizarin red on the surface of glassy carbon electrode modified with Fe3O4-multiwalled carbon nanotubes composite nanofilm. Under the optimal experimental conditions, it was showed that the proposed sensor exhibited good electrocatalytic activity to the oxidation of nitrite, and the peak current increased linearly with the nitrite concentration from 9.64 x 10(-6) mol x L(-1) to 1.30 x 10(-3) mol x L(-1) (R = 0.9976) with a detection limit of 1.19 x 10(-6) mol x L(-1) (S/N = 3). This sensor showed excellent sensitivity, wide linear range, stability and repeatability for nitrite determination with potential applications.

Understanding "revolving door" patients in general practice: a qualitative study.

PubMed

Williamson, Andrea E; Mullen, Kenneth; Wilson, Philip

2014-02-13

'Revolving door' patients in general practice are repeatedly removed from general practitioners' (GP) lists. This paper reports a qualitative portion of the first mixed methods study of these marginalised patients. We conducted qualitative semi-structured interviews with six practitioner services staff and six GPs in Scotland, utilizing Charmazian grounded theory to characterise 'revolving door' patients and their impact from professionals' perspectives. 'Revolving door' patients were reported as having three necessary characteristics; they had unreasonable expectations, exhibited inappropriate behaviours and had unmet health needs. A range of boundary breaches were reported too when 'revolving door' patients interacted with NHS staff. We utilise the 'sensitising concepts' of legitimacy by drawing on literature about 'good and bad' patients and 'dirty work designations.' We relate these to the core work of general practice and explore the role that medical and moral schemas have in how health service professionals understand and work with 'revolving door' patients. We suggest this may have wider relevance for the problem doctor patient relationship literature.

Development and evaluation of sulfonated polysulfone membranes for the zinc-ferricyanide battery

NASA Astrophysics Data System (ADS)

Arnold, C., Jr.; Assink, R. A.

1985-03-01

The successful commercialization of the zinc/ferricyanide battery being developed by Lockheed depends in part on the availability of an inexpensive, chemically stable membrane. Other essential membrane properties include low area resistivity (1 - 5 (UC OMEGA) cm(2)) and a low rate of iron permeation (4 x 10(-5) millimoles Fe(cm (2))h). A cast membrane which contained one sulfonate group per repeating unit in th backbone exhibited good stability in the alkaline ferricyanide electrolyte and satisfied the membrane requirements cited above. In ongoing single cell cycling tests, average energy efficiencies of 77% were achieved over 85 charge discharge cycles with this membrane. If sulfonate polysulfone membranes can be mass produced by extrusion, they can be considered as viable candidates to replace the expensive perfluorsulfonate membranes that were used to demonstrate the technical feasibility of the zinc/ferricyanide battery. The feasibility of preparing composite sulfonated polysulfone membranes by impregnation of microporous PTFE was also demonstrated. The manufacture of composite membranes should be possible using chemical coating equipment.

Immobilization of pectinase on oxidized pulp fiber and its application in whitewater treatment.

PubMed

Wu, Rina; He, Bei-Hai; Zhao, Guang-Lei; Qian, Li-Ying; Li, Xiao-Feng

2013-09-12

Modified pulp fiber was originally used as a new type of carrier for pectinase immobilization. Pulp fiber was oxidized by sodium periodate to produce aldehyde groups for covalently binding with amino groups of pectinase. Results showed that the enzymatic activity of immobilized pectinase on pulp fiber reached 65 μgg(-1)min(-1) when immobilization pH value, temperature and time were of 7.0, 20 °C and 15 min, respectively. The immobilized pectinase showed higher thermo stability in a wider temperature range of 40-70 °C than its free type and its optimal pH shifted from 8.0 to 8.8. Furthermore, the immobilized pectinase exhibited good operational stability. When employed in whitewater treatment of papermaking industry, it still efficiently decreased the cationic demand after operating repeatedly for six batches. The results obtained demonstrate a promising route to prepare available, cheap and biodegradable carrier for immobilizing enzymes with potential application in wastewater treatment in papermaking industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

Simulated Keratometry Repeatability in Subjects with & without Down Syndrome

PubMed Central

Ravikumar, Ayeswarya; Marsack, Jason D.; Benoit, Julia S.; Anderson, Heather A.

2016-01-01

Purpose To assess the repeatability of simulated keratometry measures obtained with Zeiss Atlas topography for subjects with and without Down syndrome (DS). Methods Corneal topography was attempted on 140 subjects with DS and 138 controls (aged 7 to 59 years). Subjects who had at least 3 measures in each eye were included in analysis (DS: n=140 eyes (70 subjects) and controls: n=264 eyes (132 subjects)). For each measurement the steep corneal power (K), corneal astigmatism, flat K orientation, power vector representation of astigmatism (J0, J45), and astigmatic dioptric difference were determined for each measurement (collectively termed keratometry values here). For flat K orientation comparisons, only eyes with >0.50 DC of astigmatism were included (DS: n=131 eyes (68 subjects) and control: n=217 eyes (119 subjects)). Repeatability was assessed using 1) group mean variability (average standard deviation (SD) across subjects), 2) coefficient of repeatability (COR) 3) coefficient of variation (COV), and 4) intraclass correlation coefficient (ICC). Results The keratometry values showed good repeatability as evidenced by low group mean variability for DS vs control eyes (≤0.26D vs ≤0.09D for all dioptric values; 4.51° vs 3.16° for flat K orientation); however, the group mean variability was significantly higher in DS eyes than control eyes for all parameters (p≤0.03). On average, group mean variability was 2.5× greater in the DS eyes compared to control eyes across the keratometry values. Other metrics of repeatability also indicated good repeatability for both populations for each keratometry value, although repeatability was always better in the control eyes. Conclusions DS eyes showed more variability (on average: 2.5×) compared to controls for all keratometry values. Although differences were statistically significant, on average 91% of DS eyes had variability ≤0.50D for steep K and astigmatism, and 75% of DS eyes had variability ≤5 degrees for flat K orientation. PMID:27741083

Characterization of a possible amyloidogenic precursor in glutamine-repeat neurodegenerative diseases.

PubMed

Armen, Roger S; Bernard, Brady M; Day, Ryan; Alonso, Darwin O V; Daggett, Valerie

2005-09-20

Several neurodegenerative diseases are linked to expanded repeats of glutamine residues, which lead to the formation of amyloid fibrils and neuronal death. The length of the repeats correlates with the onset of Huntington's disease, such that healthy individuals have <38 residues and individuals with >38 repeats exhibit symptoms. Because it is difficult to obtain atomic-resolution structural information for poly(l-glutamine) (polyQ) in aqueous solution experimentally, we performed molecular dynamics simulations to investigate the conformational behavior of this homopolymer. In simulations of 20-, 40-, and 80-mer polyQ, we observed the formation of the "alpha-extended chain" conformation, which is characterized by alternating residues in the alpha(L) and alpha(R) conformations to yield a sheet. The structural transition from disordered random-coil conformations to the alpha-extended chain conformation exhibits modest length and temperature dependence, in agreement with the experimental observation that aggregation depends on length and temperature. We propose that fibril formation in polyQ may occur through an alpha-sheet structure, which was proposed by Pauling and Corey. Also, we propose an atomic-resolution model of how the inhibitory peptide QBP1 (polyQ-binding peptide 1) may bind to polyQ in an alpha-extended chain conformation to inhibit fibril formation.

Homologous recombination occurs in a distinct retroviral subpopulation and exhibits high negative interference.

PubMed Central

Hu, W S; Bowman, E H; Delviks, K A; Pathak, V K

1997-01-01

Homologous recombination and deletions occur during retroviral replication when reverse transcriptase switches templates. While recombination occurs solely by intermolecular template switching (between copackaged RNAs), deletions can occur by an intermolecular or an intramolecular template switch (within the same RNA). To directly compare the rates of intramolecular and intermolecular template switching, two spleen necrosis virus-based vectors were constructed. Each vector contained a 110-bp direct repeat that was previously shown to delete at a high rate. The 110-bp direct repeat was flanked by two different sets of restriction site markers. These vectors were used to form heterozygotic virions containing RNAs of each parental vector, from which recombinant viruses were generated. By analyses of the markers flanking the direct repeats in recombinant and nonrecombinant proviruses, the rates of intramolecular and intermolecular template switching were determined. The results of these analyses indicate that intramolecular template switching is much more efficient than intermolecular template switching and that direct repeat deletions occur primarily through intramolecular template switching events. These studies also indicate that retroviral recombination occurs within a distinct viral subpopulation and exhibits high negative interference, whereby the selection of one recombination event increases the probability that a second recombination event will be observed. PMID:9223494

Molecular characterization of accessions of Cratylia argentea (Camaratuba) using ISSR markers.

PubMed

Luz, G A; Gomes, S O; Araujo Neto, R B; Nascimento, M S C B; Lima, P S C

2015-11-27

Cratylia argentea (Desv.) Kuntze (Fabaceae) is a drought-tolerant, perennial legume found primarily in Brazil, Bolivia, and Peru. The shrub is well adapted to acid soils and exhibits high productivity and nutritional value, characteristics that would favor its use as a dry season animal forage supplement in semiarid regions. In plant improvement programs, the production of elite hybrids with superior traits is generally achieved by crossing parents that exhibit the highest level of genetic divergence. Therefore, the aim of the present study was to assess genetic diversity among 13 accessions of C. argentea from the same population maintained in the active germplasm bank of Embrapa Meio-Norte using inter-simple sequence repeat (ISSR) markers. Genetic similarities between C. argentea accessions were estimated from Jaccard coefficients, and a dendrogram was constructed using the unweighted pair group method with arithmetic average (UPGMA). The set of 15 primers selected for ISSR analysis generated a total of 313 loci of which 79.23% were polymorphic. The mean number of bands per primer was 20.87, and the amplicons ranged from 280 to 3000 bp in size. Primers UBC834 and UBC827 generated the largest number of polymorphic loci and exhibited 90.91 and 100% polymorphism, respectively. The coefficients of genetic similarity among accessions varied between 0.49 and 0.73. UPGMA cluster analysis allowed the identification of four genotypic groups and demonstrated the existence of considerable variability within the collection. Potential progenitors were selected that would offer good possibilities of obtaining unusual and favorable combinations of genes in a plant breeding program.

Loss of capacity to recover from acidosis on repeat exercise in chronic fatigue syndrome: a case-control study.

PubMed

Jones, David E J; Hollingsworth, Kieren G; Jakovljevic, Djordje G; Fattakhova, Gulnar; Pairman, Jessie; Blamire, Andrew M; Trenell, Michael I; Newton, Julia L

2012-02-01

Chronic fatigue syndrome (CFS) patients frequently describe difficulties with repeat exercise. Here, we explore muscle bioenergetic function in response to three bouts of exercise. A total of 18 CFS (CDC 1994) patients and 12 sedentary controls underwent assessment of maximal voluntary contraction (MVC), repeat exercise with magnetic resonance spectroscopy and cardio-respiratory fitness test to determine anaerobic threshold. Chronic fatigue syndrome patients undertaking MVC fell into two distinct groups: 8 (45%) showed normal PCr depletion in response to exercise at 35% of MVC (PCr depletion >33%; lower 95% CI for controls); 10 CFS patients had low PCr depletion (generating abnormally low MVC values). The CFS whole group exhibited significantly reduced anaerobic threshold, heart rate, VO(2) , VO(2) peak and peak work compared to controls. Resting muscle pH was similar in controls and both CFS patient groups. However, the CFS group achieving normal PCr depletion values showed increased intramuscular acidosis compared to controls after similar work after each of the three exercise periods with no apparent reduction in acidosis with repeat exercise of the type reported in normal subjects. This CFS group also exhibited significant prolongation (almost 4-fold) of the time taken for pH to recover to baseline. When exercising to comparable levels to normal controls, CFS patients exhibit profound abnormality in bioenergetic function and response to it. Although exercise intervention is the logical treatment for patients showing acidosis, any trial must exclude subjects who do not initiate exercise as they will not benefit. This potentially explains previous mixed results in CFS exercise trials. © 2011 The Authors. European Journal of Clinical Investigation © 2011 Stichting European Society for Clinical Investigation Journal Foundation.

Repeatability and oblique flow response characteristics of current meters

USGS Publications Warehouse

Fulford, Janice M.; Thibodeaux, Kirk G.; Kaehrle, William R.; ,

1993-01-01

Laboratory investigation into the precision and accuracy of various mechanical-current meters are presented. Horizontal-axis and vertical-axis meters that are used for the measurement of point velocities in streams and rivers were tested. Meters were tested for repeatability and response to oblique flows. Both horizontal- and vertical-axis meters were found to under- and over-register oblique flows with errors generally increasing as the velocity and angle of flow increased. For the oblique flow tests, magnitude of errors were smallest for horizontal-axis meters. Repeatability of all meters tested was good, with the horizontal- and vertical-axis meters performing similarly.

In situ preparation of multilayer coated capillary column with HKUST-1 for separation of neutral small organic molecules by open tubular capillary electrochromatography.

PubMed

Xu, Yin-Yin; Lv, Wen-Juan; Ren, Cui-Ling; Niu, Xiao-Ying; Chen, Hong-Li; Chen, Xing-Guo

2018-01-12

The popularity of novel nanoparticles coated capillary column has aroused widespread attention of researchers. Metal organic frameworks (MOFs) with special structure and chemical properties have received great interest in separation sciences. This work presents the investigation of HKUST-1 (Hong Kong University of Science and Technology-1, called Cu 3 (BTC) 2 or MOF-199) nanoparticles as a new type of coating material for capillary electrochromatography. For the first time, three layers coating (3-LC), five layers coating (5-LC), ten layers coating (10-LC), fifteen layers coating (15-LC), twenty layers coating(20-LC) and twenty-five layers coating (25-LC) capillary columns coated with HKUST-1 nanoparticles were synthesized by covalent bond with in situ, layer-by-layer self-assembly approach. The results of scanning electron microscopy (SEM), X-ray diffraction (XRD) and plasma atomic emission spectrometry (ICP-AES) indicated that HKUST-1 was successfully grafted on the inner wall of the capillary. The separating performances of 3-LC, 5-LC, 10-LC, 15-LC, 20-LC and 25-LC open tubular (OT) capillary columns were studied with some neutral small organic molecules. The results indicated that the neutral small organic molecules were separated successfully with 10-LC, 15-LC and 20-LC OT capillary columns because of the size selectivity of lattice aperture and hydrophobicity of organic ligands. In addition, 10-LC and 15-LC OT capillary columns showed better performance for the separation of certain phenolic compounds. Furthermore, 10-LC, 15-LC and 20-LC OT capillary columns exhibited good intra-day repeatability with the relative standard deviations (RSDs; %) of migration time and peak areas lying in the range of 0.3-1.2% and 0.5-4.2%, respectively. For inter-day reproducibility, the RSDs of the three OT capillary columns were found to be lying in the range of 0.3-5.5% and 0.3-4.5% for migration time and peak area, respectively. The RSDs of retention times for column-to-column for three batches of 10-LC, 15-LC and 20-LC OT capillary columns were in the range from 2.3% to 7.2%. Moreover, the fabricated 10-LC, 15-LC and 20-LC OT capillary columns exhibited good repeatability and stability for separation, which could be used successively for more than 120 runs with no observable changes on the separation efficiency. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigation of dimensional variation in parts manufactured by fused deposition modeling using Gauge Repeatability and Reproducibility

NASA Astrophysics Data System (ADS)

Mohamed, Omar Ahmed; Hasan Masood, Syed; Lal Bhowmik, Jahar

2018-02-01

In the additive manufacturing (AM) market, the question is raised by industry and AM users on how reproducible and repeatable the fused deposition modeling (FDM) process is in providing good dimensional accuracy. This paper aims to investigate and evaluate the repeatability and reproducibility of the FDM process through a systematic approach to answer this frequently asked question. A case study based on the statistical gage repeatability and reproducibility (gage R&R) technique is proposed to investigate the dimensional variations in the printed parts of the FDM process. After running the simulation and analysis of the data, the FDM process capability is evaluated, which would help the industry for better understanding the performance of FDM technology.

Diversity and evolution of centromere repeats in the maize genome.

PubMed

Bilinski, Paul; Distor, Kevin; Gutierrez-Lopez, Jose; Mendoza, Gabriela Mendoza; Shi, Jinghua; Dawe, R Kelly; Ross-Ibarra, Jeffrey

2015-03-01

Centromere repeats are found in most eukaryotes and play a critical role in kinetochore formation. Though centromere repeats exhibit considerable diversity both within and among species, little is understood about the mechanisms that drive centromere repeat evolution. Here, we use maize as a model to investigate how a complex history involving polyploidy, fractionation, and recent domestication has impacted the diversity of the maize centromeric repeat CentC. We first validate the existence of long tandem arrays of repeats in maize and other taxa in the genus Zea. Although we find considerable sequence diversity among CentC copies genome-wide, genetic similarity among repeats is highest within these arrays, suggesting that tandem duplications are the primary mechanism for the generation of new copies. Nonetheless, clustering analyses identify similar sequences among distant repeats, and simulations suggest that this pattern may be due to homoplasious mutation. Although the two ancestral subgenomes of maize have contributed nearly equal numbers of centromeres, our analysis shows that the majority of all CentC repeats derive from one of the parental genomes, with an even stronger bias when examining the largest assembled contiguous clusters. Finally, by comparing maize with its wild progenitor teosinte, we find that the abundance of CentC likely decreased after domestication, while the pericentromeric repeat Cent4 has drastically increased.

Fuel ethanol production from sweet sorghum using repeated-batch fermentation.

PubMed

Chohnan, Shigeru; Nakane, Megumi; Rahman, M Habibur; Nitta, Youji; Yoshiura, Takanori; Ohta, Hiroyuki; Kurusu, Yasurou

2011-04-01

Ethanol was efficiently produced from three varieties of sweet sorghum using repeated-batch fermentation without pasteurization or acidification. Saccharomyces cerevisiae cells could be recycled in 16 cycles of the fermentation process with good ethanol yields. This technique would make it possible to use a broader range of sweet sorghum varieties for ethanol production. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

A parent‐completed respiratory questionnaire for 1‐year‐old children: repeatability

PubMed Central

Strippoli, Marie‐Pierre F; Silverman, Michael; Michel, Gisela; Kuehni, Claudia E

2007-01-01

Background and aims There are few standardised questionnaires for the assessment of respiratory symptoms in preschool children. We have developed and tested the short‐term repeatability of a postal questionnaire on respiratory symptoms for 1‐year‐old children. Methods A newly developed postal questionnaire for the assessment of wheeze and other respiratory symptoms was sent to parents of a population‐based random sample of 4300 children aged 12–24 months. After an interval of 3 months, a random sample of 800 respondents received the questionnaire a second time. The responses were compared using Cohen's kappa (κ) to assess agreement corrected for chance. Results The first questionnaire was returned by 3194 (74%) families, the second one by 460/800 (58%). Repeatability was excellent (κ 0.80–0.96) for questions on household characteristics, environmental exposures and family history, good (κ 0.61–0.80) for questions on prevalence, severity and treatment of wheeze, and moderate (κ 0.39–0.66) for chronic cough and upper respiratory symptoms. Conclusions This short postal questionnaire designed for use in population‐based studies has excellent repeatability for family and household characteristics and good repeatability for questions on wheeze. Short‐term changes in symptom status might be responsible for variable answers on recent chronic cough and upper respiratory symptoms. Overall, the questionnaire is a valuable instrument for community‐based research on respiratory symptoms in 1 to 2‐year‐old children. PMID:17502330

Measuring joint kinematics of treadmill walking and running: Comparison between an inertial sensor based system and a camera-based system.

PubMed

Nüesch, Corina; Roos, Elena; Pagenstert, Geert; Mündermann, Annegret

2017-05-24

Inertial sensor systems are becoming increasingly popular for gait analysis because their use is simple and time efficient. This study aimed to compare joint kinematics measured by the inertial sensor system RehaGait® with those of an optoelectronic system (Vicon®) for treadmill walking and running. Additionally, the test re-test repeatability of kinematic waveforms and discrete parameters for the RehaGait® was investigated. Twenty healthy runners participated in this study. Inertial sensors and reflective markers (PlugIn Gait) were attached according to respective guidelines. The two systems were started manually at the same time. Twenty consecutive strides for walking and running were recorded and each software calculated sagittal plane ankle, knee and hip kinematics. Measurements were repeated after 20min. Ensemble means were analyzed calculating coefficients of multiple correlation for waveforms and root mean square errors (RMSE) for waveforms and discrete parameters. After correcting the offset between waveforms, the two systems/models showed good agreement with coefficients of multiple correlation above 0.950 for walking and running. RMSE of the waveforms were below 5° for walking and below 8° for running. RMSE for ranges of motion were between 4° and 9° for walking and running. Repeatability analysis of waveforms showed very good to excellent coefficients of multiple correlation (>0.937) and RMSE of 3° for walking and 3-7° for running. These results indicate that in healthy subjects sagittal plane joint kinematics measured with the RehaGait® are comparable to those using a Vicon® system/model and that the measured kinematics have a good repeatability, especially for walking. Copyright © 2017 Elsevier Ltd. All rights reserved.

Si/Ti2O3/Reduced Graphene Oxide Nanocomposite Anodes for Lithium-Ion Batteries with Highly Enhanced Cyclic Stability.

PubMed

Park, A Reum; Son, Dae-Yong; Kim, Jung Sub; Lee, Jun Young; Park, Nam-Gyu; Park, Juhyun; Lee, Joong Kee; Yoo, Pil J

2015-08-26

Silicon (Si) has attracted tremendous attention as a high-capacity anode material for next generation Li-ion batteries (LIBs); unfortunately, it suffers from poor cyclic stability due to excessive volume expansion and reduced electrical conductivity after repeated cycles. To circumvent these issues, we propose that Si can be complexed with electrically conductive Ti2O3 to significantly enhance the reversible capacity and cyclic stability of Si-based anodes. We prepared a ternary nanocomposite of Si/Ti2O3/reduced graphene oxide (rGO) using mechanical blending and subsequent thermal reduction of the Si, TiO2 nanoparticles, and rGO nanosheets. As a result, the obtained ternary nanocomposite exhibited a specific capacity of 985 mAh/g and a Coulombic efficiency of 98.4% after 100 cycles at a current density of 100 mA/g. Furthermore, these ternary nanocomposite anodes exhibited outstanding rate capability characteristics, even with an increased current density of 10 A/g. This excellent electrochemical performance can be ascribed to the improved electron and ion transport provided by the Ti2O3 phase within the Si domains and the structurally reinforced conductive framework comprised of the rGO nanosheets. Therefore, it is expected that our approach can also be applied to other anode materials to enable large reversible capacity, excellent cyclic stability, and good rate capability for high-performance LIBs.

Solid polymeric electrolytes for lithium batteries

DOEpatents

Angell, Charles A.; Xu, Wu; Sun, Xiaoguang

2006-03-14

Novel conductive polyanionic polymers and methods for their preparion are provided. The polyanionic polymers comprise repeating units of weakly-coordinating anionic groups chemically linked to polymer chains. The polymer chains in turn comprise repeating spacer groups. Spacer groups can be chosen to be of length and structure to impart desired electrochemical and physical properties to the polymers. Preferred embodiments are prepared from precursor polymers comprising the Lewis acid borate tri-coordinated to a selected ligand and repeating spacer groups to form repeating polymer chain units. These precursor polymers are reacted with a chosen Lewis base to form a polyanionic polymer comprising weakly coordinating anionic groups spaced at chosen intervals along the polymer chain. The polyanionic polymers exhibit high conductivity and physical properties which make them suitable as solid polymeric electrolytes in lithium batteries, especially secondary lithium batteries.

Performance analysis of wideband data and television channels. [space shuttle communications

NASA Technical Reports Server (NTRS)

Geist, J. M.

1975-01-01

Several aspects are discussed of space shuttle communications, including the return link (shuttle-to-ground) relayed through a satellite repeater (TDRS). The repeater exhibits nonlinear amplification and an amplitude-dependent phase shift. Models were developed for various link configurations, and computer simulation programs based on these models are described. Certain analytical results on system performance were also obtained. For the system parameters assumed, the results indicate approximately 1 db degradation relative to a link employing a linear repeater. While this degradation is dependent upon the repeater, filter bandwidths, and modulation parameters used, the programs can accommodate changes to any of these quantities. Thus the programs can be applied to determine the performance with any given set of parameters, or used as an aid in link design.

Fatigue-induced balance impairment in young soccer players.

PubMed

Pau, Massimiliano; Ibba, Gianfranco; Attene, Giuseppe

2014-01-01

Although balance is generally recognized to be an important feature in ensuring good performance in soccer, its link with functional performance remains mostly unexplored, especially in young athletes. To investigate changes in balance induced by fatigue for unipedal and bipedal static stances in young soccer players. Crossover study. Biomechanics laboratory and outdoor soccer field. Twenty-one male soccer players (age = 14.5 ± 0.2 years, height = 164.5 ± 5.6 cm, mass = 56.8 ± 6.8 kg). Static balance was assessed with postural-sway analysis in unipedal and bipedal upright stance before and after a fatigue protocol consisting of a repeated sprint ability (RSA) test (2 × 15-m shuttle sprint interspersed with 20 seconds of passive recovery, repeated 6 times). On the basis of the center-of-pressure (COP) time series acquired during the experimental tests, we measured sway area, COP path length, and COP maximum displacement and velocity in the anteroposterior and mediolateral directions. Fatigue increased all sway values in bipedal stance and all values except COP velocity in the mediolateral direction in unipedal stance. Fatigue index (calculated on the basis of RSA performance) was positively correlated with fatigue/rest sway ratio for COP path length and COP velocity in the anteroposterior and mediolateral directions for nondominant single-legged stance. Fatigued players exhibited reduced performance of the postural-control system. Participants with better performance in the RSA test appeared less affected by balance impairment, especially in single-legged stance.

Structure and Dynamics of DNA and RNA Double Helices Obtained from the CCG and GGC Trinucleotide Repeats.

PubMed

Pan, Feng; Man, Viet Hoang; Roland, Christopher; Sagui, Celeste

2018-04-26

Expansions of both GGC and CCG sequences lead to a number of expandable, trinucleotide repeat (TR) neurodegenerative diseases. Understanding of these diseases involves, among other things, the structural characterization of the atypical DNA and RNA secondary structures. We have performed molecular dynamics simulations of (GCC) n and (GGC) n homoduplexes in order to characterize their conformations, stability, and dynamics. Each TR has two reading frames, which results in eight nonequivalent RNA/DNA homoduplexes, characterized by CpG or GpC steps between the Watson-Crick base pairs. Free energy maps for the eight homoduplexes indicate that the C-mismatches prefer anti-anti conformations, while G-mismatches prefer anti-syn conformations. Comparison between three modifications of the DNA AMBER force field shows good agreement for the mismatch free energy maps. The mismatches in DNA-GCC (but not CCG) are extrahelical, forming an extended e-motif. The mismatched duplexes exhibit characteristic sequence-dependent step twist, with strong variations in the G-rich sequences and the e-motif. The distribution of Na + is highly localized around the mismatches, especially G-mismatches. In the e-motif, there is strong Na + binding by two G(N7) atoms belonging to the pseudo GpC step created when cytosines are extruded and by extrahelical cytosines. Finally, we used a novel technique based on fast melting by means of an infrared laser pulse to classify the relative stability of the different DNA-CCG and -GGC homoduplexes.

Cross-cultural adaptation and validation of the Korean version of the EQ-5D in patients with rheumatic diseases.

PubMed

Kim, Myoung-Hee; Cho, Young-Shin; Uhm, Wan-Sik; Kim, Sehyun; Bae, Sang-Cheol

2005-06-01

This study aimed to determine the cross-cultural adaptation and validation of the Korean version of the EQ-5D in rheumatic conditions. Translation, back-translation and cognitive debriefing were performed according to the EuroQol group's guidelines. For validity, 508 patients were recruited and administered the EQ-5D, Short-Form 36 and condition-specific measures. Construct validity and sensitivity were evaluated by testing a-priori hypotheses. For reliability, another 57 patients repeated the EQ-5D at 1-week interval, and intra-class correlations (ICC) and kappa statistics were estimated. For responsiveness, another 60 patients repeated it at 12-week interval within the context of clinical trial, and standardized response mean(SRM) were calculated. The cross-cultural adaptation produced no major modifications in the scale. The associations of the EQ-5D with the generic- and condition-specific measures were observed as expected in hypotheses: the higher EQ-5Dindex and EQ-5D(VAS) scores, the better health status by generic- or condition-specific measures, and the better functional class. The ICCs were 0.751 and 0.767, respectively, and kappa ranged from 0.455 to 0.772. The SRM were 0.649 and 0.410, respectively. The Korean EQ-5D exhibits good validity and sensitivity in various rheumatic conditions. Although its reliability and responsiveness were not excellent, it seems acceptable if condition-specific measures are applied together.

Instability of expanded CAG/CAA repeats in spinocerebellar ataxia type 17.

PubMed

Gao, Rui; Matsuura, Tohru; Coolbaugh, Mary; Zühlke, Christine; Nakamura, Koichiro; Rasmussen, Astrid; Siciliano, Michael J; Ashizawa, Tetsuo; Lin, Xi

2008-02-01

Trinucleotide repeat expansions are dynamic mutations causing many neurological disorders, and their instability is influenced by multiple factors. Repeat configuration seems particularly important, and pure repeats are thought to be more unstable than interrupted repeats. But direct evidence is still lacking. Here, we presented strong support for this hypothesis from our studies on spinocerebellar ataxia type 17 (SCA17). SCA17 is a typical polyglutamine disease caused by CAG repeat expansion in TBP (TATA binding protein), and is unique in that the pure expanded polyglutamine tract is coded by either a simple configuration with long stretches of pure CAGs or a complex configuration containing CAA interruptions. By small pool PCR (SP-PCR) analysis of blood DNA from SCA17 patients of distinct racial backgrounds, we quantitatively assessed the instability of these two types of expanded alleles coding similar length of polyglutamine expansion. Mutation frequency in patients harboring pure CAG repeats is 2-3 folds of those with CAA interruptions. Interestingly, the pure CAG repeats showed both expansion and deletion while the interrupted repeats exhibited mostly deletion at a significantly lower frequency. These data strongly suggest that repeat configuration is a critical determinant for instability, and CAA interruptions might serve as a limiting element for further expansion of CAG repeats in SCA17 locus, suggesting a molecular basis for lack of anticipation in SCA17 families with interrupted CAG expansion.

Non-RVD mutations that enhance the dynamics of the TAL repeat array along the superhelical axis improve TALEN genome editing efficacy

PubMed Central

Tochio, Naoya; Umehara, Kohei; Uewaki, Jun-ichi; Flechsig, Holger; Kondo, Masaharu; Dewa, Takehisa; Sakuma, Tetsushi; Yamamoto, Takashi; Saitoh, Takashi; Togashi, Yuichi; Tate, Shin-ichi

2016-01-01

Transcription activator-like effector (TALE) nuclease (TALEN) is widely used as a tool in genome editing. The DNA binding part of TALEN consists of a tandem array of TAL-repeats that form a right-handed superhelix. Each TAL-repeat recognises a specific base by the repeat variable diresidue (RVD) at positions 12 and 13. TALEN comprising the TAL-repeats with periodic mutations to residues at positions 4 and 32 (non-RVD sites) in each repeat (VT-TALE) exhibits increased efficacy in genome editing compared with a counterpart without the mutations (CT-TALE). The molecular basis for the elevated efficacy is unknown. In this report, comparison of the physicochemical properties between CT- and VT-TALEs revealed that VT-TALE has a larger amplitude motion along the superhelical axis (superhelical motion) compared with CT-TALE. The greater superhelical motion in VT-TALE enabled more TAL-repeats to engage in the target sequence recognition compared with CT-TALE. The extended sequence recognition by the TAL-repeats improves site specificity with limiting the spatial distribution of FokI domains to facilitate their dimerization at the desired site. Molecular dynamics simulations revealed that the non-RVD mutations alter inter-repeat hydrogen bonding to amplify the superhelical motion of VT-TALE. The TALEN activity is associated with the inter-repeat hydrogen bonding among the TAL repeats. PMID:27883072

Controllable growth of Prussian blue nanostructures on carboxylic group-functionalized carbon nanofibers and its application for glucose biosensing.

PubMed

Wang, Li; Ye, Yinjian; Zhu, Haozhi; Song, Yonghai; He, Shuijian; Xu, Fugang; Hou, Haoqing

2012-11-16

Glucose detection is very important in biological analysis, clinical diagnosis and the food industry, and especially for the routine monitoring of diabetes. This work presents an electrochemical approach to the detection of glucose based on Prussian blue (PB) nanostructures/carboxylic group-functionalized carbon nanofiber (FCNF) nanocomposites. The hybrid nanocomposites were constructed by growing PB onto the FCNFs. The obtained PB-FCNF nanocomposites were characterized by scanning electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy. The mechanism of formation of PB-FCNF nanocomposites was investigated and is discussed in detail. The PB-FCNF modified glassy carbon electrode (PB-FCNF/GCE) shows good electrocatalysis toward the reduction of H(2)O(2), a product from the reduction of O(2) followed by glucose oxidase (GOD) catalysis of the oxidation of glucose to gluconic acid. Further immobilizing GOD on the PB-FCNF/GCE, an amperometric glucose biosensor was achieved by monitoring the generated H(2)O(2) under a relatively negative potential. The resulting glucose biosensor exhibited a rapid response of 5 s, a low detection limit of 0.5 μM, a wide linear range of 0.02-12 mM, a high sensitivity of 35.94 μA cm(-2) mM(-1), as well as good stability, repeatability and selectivity. The sensor might be promising for practical application.

Surface imprinting on nano-TiO2 as sacrificial material for the preparation of hollow chlorogenic acid imprinted polymer and its recognition behavior

NASA Astrophysics Data System (ADS)

Li, Hui; Li, Gui; Li, Zhiping; Lu, Cuimei; Li, Yanan; Tan, Xianzhou

2013-01-01

Surface imprinting chlorogenic acid (CGA) on nano-TiO2 particles as sacrificial support material was successfully performed by using 4-vinylpyridine (4-VP) as functional monomer to obtain a hollow CGA-imprinted polymer (H-MIP1). Fourier transmission infrared spectrometry (FTIR) and scanning electron microscopy (SEM) were utilized for structurally characterizing the polymers obtained and adsorption dynamics and thermodynamic behavior investigated according to different models. Binding selectivity, adsorption capacity and the reusability for this H-MIP1 were also evaluated. This hollow CGA imprinted polymer shows rapid binding dynamics and higher binding capability toward the template molecules. The pseudo first-order kinetic model was shown best to describe the binding process of CGA on the H-MIP1 and Langmuir isotherm model best to fit the experimental adsorption isotherm data. Through adsorption isotherms at different temperatures, thermodynamic parameter values were obtained. Selectivity coefficients for the H-MIP1 toward the template were 2.209, 3.213, 1.746 and 2.353 relative to CA, VA, PCA and GA, respectively. This H-MIP1 was also indicated with a good imprint effect and a high capability to capture CGA from methanol extract of Eucommia ulmoides (E. ulmoides) leaves. Additionally, a good reusability for this imprinted polymer was exhibited during repeated adsorption-desorption use.

A glucose biosensor based on glucose oxidase immobilized on three-dimensional porous carbon electrodes.

PubMed

Chen, Jingyi; Zhu, Rong; Huang, Jia; Zhang, Man; Liu, Hongyu; Sun, Min; Wang, Li; Song, Yonghai

2015-08-21

A novel glucose biosensor was developed by immobilizing glucose oxidase (GOD) on a three-dimensional (3D) porous kenaf stem-derived carbon (3D-KSC) which was firstly proposed as a novel supporting material to load biomolecules for electrochemical biosensing. Here, an integrated 3D-KSC electrode was prepared by using a whole piece of 3D-KSC to load the GOD molecules for glucose biosensing. The morphologies of integrated 3D-KSC and 3D-KSC/GOD electrodes were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM results revealed a 3D honeycomb macroporous structure of the integrated 3D-KSC electrode. The TEM results showed some microporosities and defects in the 3D-KSC electrode. The electrochemical behaviors and electrocatalytic performance of the integrated 3D-KSC/GOD electrode were evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The effects of pH and scan rates on the electrochemical response of the biosensor have been studied in detail. The glucose biosensor showed a wide linear range from 0.1 mM to 14.0 mM with a high sensitivity of 1.73 μA mM(-1) and a low detection limit of 50.75 μM. Furthermore, the glucose biosensor exhibited high selectivity, good repeatability and reproducibility, and good stability.

Functionalized Sugarcane Bagasse for U(VI) Adsorption from Acid and Alkaline Conditions.

PubMed

Su, Shouzheng; Liu, Qi; Liu, Jingyuan; Zhang, Hongsen; Li, Rumin; Jing, Xiaoyan; Wang, Jun

2018-01-15

The highly efficient removal of uranium from mine tailings effluent, radioactive wastewater and enrichment from seawater is of great significance for the development of nuclear industry. In this work, we prepared an efficient U(VI) adsorbent by EDTA modified sugarcane bagasse (MESB) with a simple process. The prepared adsorbent preserves high adsorptive capacity for UO 2 2+ (pH 3.0) and uranyl complexes, such as UO 2 (OH) + , (UO 2 ) 2 (OH) 2 2+ and (UO 2 ) 3 (OH) 5 + (pH 4.0 and pH 5.0) and good repeatability in acidic environment. The maximum adsorption capacity for U(VI) at pH 3.0, 4.0 and 5.0 is 578.0, 925.9 and 1394.1 mg/g and the adsorption capacity loss is only 7% after five cycles. With the pH from 3.0 to 5.0, the inhibitive effects of Na + and K + decreased but increased of Mg 2+ and Ca 2+ . MESB also exhibits good adsorption for [UO 2 (CO 3 ) 3 ] 4- at pH 8.3 from 10 mg/L to 3.3 μg/L. Moreover, MESB could effectively extract U(VI) from simulated seawater in the presence of other metals ions. This work provided a general and efficient uranyl enriched material for nuclear industry.

Innovative analytical method for the determination of underivatized tributyltin and pentachlorophenol in seawater by gas chromatography-triple quadrupole mass spectrometry.

PubMed

Amendola, Luca; Cortese, Maria; Vinatoru, Daniela; Sposato, Silvana; Insogna, Susanna

2017-07-04

Tributyltin (TBT) and pentachlorophenol (PCP) are listed as priority substances that warrant monitoring in the European Water Framework Directive (WFD 2000/60/CE), since TBT and PCP were identified as environmental endocrine disruptors and exhibit considerable toxicity toward both aquatic organisms and mammals even at very low levels. This paper shows a novel approach to analyze underivatized tributyltin (TBT) and pentachlorophenol (PCP) in seawater based on capillary gas chromatography-triple quadrupole mass spectrometry. The optimized extraction method for TBT an PCP in water involved liquid-liquid microextraction with toluene. The reduced extract was added with a solvent mix, composed of methanol and trimethylsilyl derivatives of methanol (MeOTMS), that allowed good chromatographic resolution of underivatized TBT and PCP, interacting as a lubricant along the glass liner during the injection phase. The proposed method showed good linearity and repeatability (RSD%<20% at 0.05 ng L -1 for TBT and 0.2 μg L -1 for PCP). The overall recoveries were 74% and 106% for TBT and PCP, respectively. Very low quantification limits that met the strict statutory and regulatory demands were achieved: 0.002 ng L -1 for TBT and 0.050 μg L -1 for PCP. Copyright © 2017 Elsevier B.V. All rights reserved.

An Enzyme-Induced Novel Biosensor for the Sensitive Electrochemical Determination of Isoniazid

PubMed Central

Chokkareddy, Rajasekhar; Bhajanthri, Natesh Kumar; Redhi, Gan G.

2017-01-01

In this present work, a glassy carbon electrode (GCE) was modified primarily with multiwalled carbon nanotubes (MWCNTs) and a composite of MWCNTs and titanium oxide nanoparticles (TiO2NPs). The enzyme horseradish peroxidase (HRP) was immobilized to enhance the sensing ability of GCE. The proposed biosensor was used for the sensitive determination of isoniazid (INZ) in various pharmaceutical samples. The electrochemical behaviour of the developed MWCNT-TiO2NPs-HRP-GCE biosensor was studied by using cyclic voltammetry (CV) and differential pulse voltammetric (DPV) techniques. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetry (TGA) and transmission electron microscopy (TEM) techniques were used to characterize the developed sensor. Phosphate buffer solution (PBS) with pH 7 was used as supporting electrolyte in the present investigation. The cyclic voltammetric results revealed that the increment of anodic peak currents for the enzyme-induced sensor was almost 8-fold greater than that of a bare GCE. The DPV technique exhibited good limit of detection and limit of quantification values, viz., 0.0335 μM and 0.1118 μM, respectively. Moreover, the developed sensor showed long-lasting stability and repeatability without any interferents. This strongly indicates that the fabricated sensor shows outstanding electrochemical performance towards INZ, with excellent selectivity and sensitivity. The developed sensor was successfully applied to pharmaceutical samples and gave good percentages of recoveries. PMID:28587260

151-km single-end phase-sensitive optical time-domain reflectometer assisted by optical repeater

NASA Astrophysics Data System (ADS)

Song, Muping; Zhu, Weiji; Xia, Qiaolan; Yin, Cong; Lu, Yan; Wu, Ying; Zhuang, Shouwang

2018-02-01

A phase-sensitive optical time-domain reflectometry (ϕOTDR) system that can detect intrusion over 150 km is presented. The ϕOTDR system uses nonbalanced optical repeaters to extend the sensing distance. The repeater consists of two erbium-doped optical fiber amplifiers (EDFAs) and one Raman amplifier (RA). One EDFA power amplifier amplifies the forward-transmitting pulse, and one EDFA preamplifier is used for the backscattering signal, respectively. The RA helps keeping the power along the fiber stable. The optical repeater is installed at the connection of two adjacent fibers to compensate the power decline due to fiber loss. It is easy to install the repeater midway among the fiber links in the system for longer-distance sensing since there is no need of modifying the original sensing system. The theoretical analysis of the repeater is given to describe its effect on the distributed sensing. In experiments, several ϕOTDR traces show a good agreement with theoretical results. Using the optical repeater, 35-Hz vibration at 151 km is successfully measured with signal-to-noise ratio of 8 dB without extra signal processing.

Firefighter Safety Zone: The effect of terrain slope of separation distance

Treesearch

Bret Butler; Jason Forthofer

2010-01-01

Perhaps one of the most critical decisions made on wildland fires is the identification of suitable safety zones for firefighters during daily fire management operations. To be effective (timely, repeatable, and accurate), these decisions rely on good training and good judgement. The current safety zone guidelines used in the US (see fig. 1) and published in the...

An electronic nose for reliable measurement and correct classification of beverages.

PubMed

Mamat, Mazlina; Samad, Salina Abdul; Hannan, Mahammad A

2011-01-01

This paper reports the design of an electronic nose (E-nose) prototype for reliable measurement and correct classification of beverages. The prototype was developed and fabricated in the laboratory using commercially available metal oxide gas sensors and a temperature sensor. The repeatability, reproducibility and discriminative ability of the developed E-nose prototype were tested on odors emanating from different beverages such as blackcurrant juice, mango juice and orange juice, respectively. Repeated measurements of three beverages showed very high correlation (r > 0.97) between the same beverages to verify the repeatability. The prototype also produced highly correlated patterns (r > 0.97) in the measurement of beverages using different sensor batches to verify its reproducibility. The E-nose prototype also possessed good discriminative ability whereby it was able to produce different patterns for different beverages, different milk heat treatments (ultra high temperature, pasteurization) and fresh and spoiled milks. The discriminative ability of the E-nose was evaluated using Principal Component Analysis and a Multi Layer Perception Neural Network, with both methods showing good classification results.

Optimization of Analytical Conditions for a Rapid Determination of Aniline in Environmental Water by Liquid Chromatography/Tandem Mass Spectrometry.

PubMed

Furukawa, Koji; Hashimoto, Makoto; Kaneco, Satoshi

2017-01-01

A rapid determination of aniline in environmental water was examined based on liquid chromatography/tandem mass spectrometry (LC/MS/MS). Environmental water samples were diluted 20-fold with Mill-Q water and measured by LC/MS/MS after adding a surrogate substance (aniline-d 5 ). In the results of the present study, the calibration curve of aniline showed good linearity in the range of 0.05 - 2.0 μg/L. Since the RSD (repeatability) by measuring repeatedly an aniline standard solution (0.05 μg/L, n = 7) was 3.2%, the repeatability of this work was very excellent. In addition, the recovery rate of aniline in environmental water was in the range of 99.0 - 102% with RSD 3.4 - 7.7%, and very good recovery test results were obtained. From these results, this analytical method was confirmed to be effective for aniline measurements of environmental water samples. Also, it is possible to conduct rapid analyses of aniline in environmental water without any solid-phase extraction process, compared to the solid-phase extraction-GC/MS method.

An Electronic Nose for Reliable Measurement and Correct Classification of Beverages

PubMed Central

Mamat, Mazlina; Samad, Salina Abdul; Hannan, Mahammad A.

2011-01-01

This paper reports the design of an electronic nose (E-nose) prototype for reliable measurement and correct classification of beverages. The prototype was developed and fabricated in the laboratory using commercially available metal oxide gas sensors and a temperature sensor. The repeatability, reproducibility and discriminative ability of the developed E-nose prototype were tested on odors emanating from different beverages such as blackcurrant juice, mango juice and orange juice, respectively. Repeated measurements of three beverages showed very high correlation (r > 0.97) between the same beverages to verify the repeatability. The prototype also produced highly correlated patterns (r > 0.97) in the measurement of beverages using different sensor batches to verify its reproducibility. The E-nose prototype also possessed good discriminative ability whereby it was able to produce different patterns for different beverages, different milk heat treatments (ultra high temperature, pasteurization) and fresh and spoiled milks. The discriminative ability of the E-nose was evaluated using Principal Component Analysis and a Multi Layer Perception Neural Network, with both methods showing good classification results. PMID:22163964

Repeated lysergic acid diethylamide in an animal model of depression: Normalisation of learning behaviour and hippocampal serotonin 5-HT2 signalling.

PubMed

Buchborn, Tobias; Schröder, Helmut; Höllt, Volker; Grecksch, Gisela

2014-06-01

A re-balance of postsynaptic serotonin (5-HT) receptor signalling, with an increase in 5-HT1A and a decrease in 5-HT2A signalling, is a final common pathway multiple antidepressants share. Given that the 5-HT1A/2A agonist lysergic acid diethylamide (LSD), when repeatedly applied, selectively downregulates 5-HT2A, but not 5-HT1A receptors, one might expect LSD to similarly re-balance the postsynaptic 5-HT signalling. Challenging this idea, we use an animal model of depression specifically responding to repeated antidepressant treatment (olfactory bulbectomy), and test the antidepressant-like properties of repeated LSD treatment (0.13 mg/kg/d, 11 d). In line with former findings, we observe that bulbectomised rats show marked deficits in active avoidance learning. These deficits, similarly as we earlier noted with imipramine, are largely reversed by repeated LSD administration. Additionally, bulbectomised rats exhibit distinct anomalies of monoamine receptor signalling in hippocampus and/or frontal cortex; from these, only the hippocampal decrease in 5-HT2 related [(35)S]-GTP-gamma-S binding is normalised by LSD. Importantly, the sham-operated rats do not profit from LSD, and exhibit reduced hippocampal 5-HT2 signalling. As behavioural deficits after bulbectomy respond to agents classified as antidepressants only, we conclude that the effect of LSD in this model can be considered antidepressant-like, and discuss it in terms of a re-balance of hippocampal 5-HT2/5-HT1A signalling. © The Author(s) 2014.

Characterization of a possible amyloidogenic precursor in glutamine-repeat neurodegenerative diseases

PubMed Central

Armen, Roger S.; Bernard, Brady M.; Day, Ryan; Alonso, Darwin O. V.; Daggett, Valerie

2005-01-01

Several neurodegenerative diseases are linked to expanded repeats of glutamine residues, which lead to the formation of amyloid fibrils and neuronal death. The length of the repeats correlates with the onset of Huntington's disease, such that healthy individuals have <38 residues and individuals with >38 repeats exhibit symptoms. Because it is difficult to obtain atomic-resolution structural information for poly(l-glutamine) (polyQ) in aqueous solution experimentally, we performed molecular dynamics simulations to investigate the conformational behavior of this homopolymer. In simulations of 20-, 40-, and 80-mer polyQ, we observed the formation of the “α-extended chain” conformation, which is characterized by alternating residues in the αL and αR conformations to yield a sheet. The structural transition from disordered random-coil conformations to the α-extended chain conformation exhibits modest length and temperature dependence, in agreement with the experimental observation that aggregation depends on length and temperature. We propose that fibril formation in polyQ may occur through an α-sheet structure, which was proposed by Pauling and Corey [Pauling, L. & Corey, R. B. (1951) Proc. Natl. Acad. Sci. USA 37, 251-256]. Also, we propose an atomic-resolution model of how the inhibitory peptide QBP1 (polyQ-binding peptide 1) may bind to polyQ in an α-extended chain conformation to inhibit fibril formation. PMID:16157882

Hydrogel Walkers with Electro-Driven Motility for Cargo Transport.

PubMed

Yang, Chao; Wang, Wei; Yao, Chen; Xie, Rui; Ju, Xiao-Jie; Liu, Zhuang; Chu, Liang-Yin

2015-08-28

In this study, soft hydrogel walkers with electro-driven motility for cargo transport have been developed via a facile mould-assisted strategy. The hydrogel walkers consisting of polyanionic poly(2-acrylamido-2-methylpropanesulfonic acid-co-acrylamide) exhibit an arc looper-like shape with two "legs" for walking. The hydrogel walkers can reversibly bend and stretch via repeated "on/off" electro-triggers in electrolyte solution. Based on such bending/stretching behaviors, the hydrogel walkers can move their two "legs" to achieve one-directional walking motion on a rough surface via repeated "on/off" electro-triggering cycles. Moreover, the hydrogel walkers loaded with very heavy cargo also exhibit excellent walking motion for cargo transport. Such hydrogel systems create new opportunities for developing electro-controlled soft systems with simple design/fabrication strategies in the soft robotic field for remote manipulation and transportation.

Time-lapse CO2 monitoring using ambient-noise seismic interferometry: a feasibility study from Ketzin, Germany

NASA Astrophysics Data System (ADS)

Boullenger, Boris; Verdel, Arie; Paap, Bob; Thorbecke, Jan; Draganov, Deyan

2015-04-01

Seismic interferometry applied to ambient-noise measurements allows retrieval of the Green's function between two seismic receivers, by cross-correlating their recordings, as if from a source at one of the receivers. We propose to use ambient-noise seismic interferometry (ANSI) to retrieve reflection data. The time-lapse differences between different vintages of the retrieved data may help characterize property changes within a geologic reservoir with varying CO2 saturation. We test the feasibility of this time-lapse passive seismic method with numerical experiments based on the CO2-storage site of Ketzin, Germany. Ambient-noise recordings from Ketzin exhibit significant passive body-wave energy (from natural tremors or induced seismicity in the vicinity of the reservoir), which is advantageous to retrieve reflections with ANSI. The ANSI numerical experiments aim to understand what the requirements are for the recorded body-wave noise to retrieve the time-lapse reflection signal caused by an increase of CO2 saturation in the reservoir. For this purpose, we design two velocity scenarios at Ketzin: a base scenario before the injection of CO2, and a repeat scenario corresponding to a P-wave velocity decline in the reservoir by 20 percent. For both scenarios, we simulate passive seismic experiments of body-wave noise recordings that may take several days or months to record in the field. The passive recordings are obtained by modelling global (direct wave, internal and surface multiples) transmission responses from band-limited subsurface noise sources, randomly triggered in space and time. The time-lapse reflection signal is obtained by taking the differences between the base and the repeat retrieved reflection data (virtual common-shot gathers). We found that the time-lapse signal is still recovered with ANSI even if the base and repeat retrieved reflection data are partially polluted with artifacts. This means that uneven illumination of the array does not necessarily exclude acceptable time-lapse signal retrieval. Furthermore, the clarity of the time-lapse signal at the reservoir level increases with increasing repeatability of the two passive experiments. The increase in repeatability is achieved when the contributing noise sources form denser clusters that share analogous spatial coverage. To support the merits of the numerical experiments, we applied ANSI (by auto-correlation) to three days of Ketzin passive field-data and compare the retrieved responses with the modelling results. The data are recorded at a permanent array of sensors (hydrophones and geophones) installed above the injection site. We used the records from the buried line of the array that consists of sensors lying at 50-meters depth. These records are less contaminated with surface noise and preserve passive body-wave events better than surface-recorded data. The retrieved responses exhibit significant correspondence with the existing active-seismic field data as well as with our modelled ANSI and active responses. Key reflection events seem to be retrieved at the expected arrival times and support the idea that the settings and characteristics of the ambient noise at Ketzin offer good potential for time-lapse ANSI to monitor CO2 sequestration.

Time to stability differences between male and female dancers after landing from a jump on flat and inclined floors.

PubMed

Pappas, Evangelos; Kremenic, Ian; Liederbach, Marijeanne; Orishimo, Karl F; Hagins, Marshall

2011-07-01

To determine the effect of gender and inclined floor on time to stability (TTS) after landing from a vertical jump. This study used a repeated measures design with male and female professional dancers landing on a flat and 4 inclined floors. A repeated measures univariate analysis of variance (gender × floor) was performed on TTS in the anterior-posterior and medial-lateral directions. Biomechanics laboratory. Twenty-three female and 13 male professional dancers. Gender and floor inclination (flat, posterior, anterior, lateral, and medial). Time to stability in the anterior-posterior and medial-lateral directions after landing from a vertical jump. Female dancers exhibited longer TTS in both directions (P ≤ 0.05). Floor inclination or the interaction of gender × floor did not have an effect on TTS (P > 0.3). Female dancers exhibited longer TTS after landing from a vertical jump compared with their male counterparts. This balance difference may be a factor related to the higher rate of ankle sprain among female dancers. Additionally, professional dancers exhibited similar TTS when landing on flat and inclined floors.

Measurement of central corneal thickness with optical low-coherence reflectometry and ultrasound pachymetry in normal and post-femtosecond laser in situ keratomileusis eyes.

PubMed

Huang, Jinhai; Liao, Na; Savini, Giacomo; Li, Yuanguang; Bao, Fangjun; Yu, Ye; Yu, Ayong; Wang, Qinmei

2015-02-01

To determine the repeatability and reproducibility of measurements of central corneal thickness (CCT) using optical low-coherence reflectometry (Lenstar LS900; Haag Streit) in normal eyes and post-femtosecond laser in situ keratomileusis (post-FS-LASIK) eyes and evaluate their agreement with ultrasound (US) pachymetry. CCT was measured using Lenstar and US pachymetry sequentially in normal and post-FS-LASIK eyes by 2 experienced observers. Intraoperator repeatability and interoperator reproducibility were assessed by within-subject standard deviation, test-retest repeatability, coefficient of variation (CoV), and intraclass correlation coefficient. Paired t-tests and Bland-Altman plots were used for analyzing agreement between the 2 devices. In this study, 55 healthy subjects and 50 post-FS-LASIK patients were recruited. Test-retest repeatability of Lenstar was within 10 μm, CoV was less than 1.0%, and intraclass correlation coefficient was more than 0.9 in both normal and post-FS-LASIK groups. Mean difference between these methods was 1.4 ± 4.2 μm and -1.7 ± 5.4 μm, respectively. Moreover, measurements of CCT showed narrow 95% limits of agreement (range, normal group: -6.8 and 9.6 μm; post-FS-LASIK group: -12.4 and 8.9 μm), which implied good agreement. Measurements of CCT using Lenstar showed excellent intraoperator repeatability and interoperator reproducibility both in normal eyes and post-FS-LASIK eyes. Measurements of CCT using Lenstar and US pachymetry showed good agreement and both can be used interchangeably.

The repeatability and characteristics of right ventricular longitudinal strain imaging by speckle-tracking echocardiography in healthy dogs.

PubMed

Morita, T; Nakamura, K; Osuga, T; Yokoyama, N; Khoirun, N; Morishita, K; Sasaki, N; Ohta, H; Takiguchi, M

2017-08-01

To assess the repeatability and characteristics of echocardiographic indices of the right ventricular (RV) function derived from speckle-tracking echocardiography. Fourteen laboratory Beagles and 103 privately owned dogs without cardiac disease were involved in this study. Right ventricular longitudinal strain, strain rate, and a strain-related index for assessing RV dyssynchrony derived from speckle-tracking echocardiography were obtained by two different observers using five Beagles. Within-day, between-day, and interobserver coefficients of variation and the intraclass correlation coefficient of speckle-tracking echocardiography indices were determined. Both speckle-tracking echocardiography and conventional indices of RV function, including the peak velocity of systolic tricuspid annular motion, tricuspid annulus plane systolic excursion, fractional area change, and the Tei index, were obtained from 14 Beagles and 103 privately owned dogs. Relationships between echocardiographic indices and the body weight, heart rate, age, and sex were estimated by regression analysis. Speckle-tracking echocardiographic indices showed good within-day repeatability, between-day and interobserver repeatability were moderate to good. In large dogs, RV longitudinal strain, strain rate, and fractional area change were significantly decreased, while the index of RV dyssynchrony, systolic tricuspid annular motion, tricuspid annulus plane systolic excursion, and the Tei index were increased. All speckle-tracking and conventional echocardiographic indices were correlated with the body weight. The speckle-tracking echocardiography indices were highly repeatable and body weight affected speckle-tracking echocardiography indices in dogs. Further studies are needed to apply speckle-tracking echocardiography indices in dogs with cardiac disease. Copyright © 2017 Elsevier B.V. All rights reserved.

The Beauty of the Acronym!: "Good Management Begins with Good People"

ERIC Educational Resources Information Center

Vicars, Dennis

2010-01-01

Acronyms are not only short and catchy, but they may also help one to quickly hone in on what's important and to set priorities. In a field that seems to bask in process, over-analysis, and repeated discussion, the acronym "cuts to the chase" and keeps everyone on the same page. The last Management Maxim column ("Exchange," March/April 2010)…

The Repeated Name Penalty, the Overt Pronoun Penalty, and Topic in Japanese.

PubMed

Shoji, Shinichi; Dubinsky, Stanley; Almor, Amit

2017-02-01

When reading sentences with an anaphoric reference to a subject antecedent, repeated-name anaphors result in slower reading times relative to pronouns (the Repeated Name Penalty: RNP), and overt pronouns are read slower than null pronouns (the Overt Pronoun Penalty: OPP). Because in most languages previously tested, the grammatical subject is typically also the discourse topic it remains unclear whether these effects reflect anaphors' subject-hood or their topic-hood. To address this question we conducted a self-paced reading experiment in Japanese, a language which morphologically marks both subjects and topics overtly. Our results show that both repeated-name topic-subject anaphors and repeated-name non-topic-subject anaphors exhibit the RNP and that both overt-pronoun topic-subject and overt-pronoun non-topic-subject anaphors show the OPP. However, a detailed examination of performance revealed an interaction between the anaphor topic marking, reference form, and the antecedent's grammatical status, indicating that the effect of the antecedent's grammatical status is strongest for null pronoun and repeated name subject anaphors and that the overt form most similar to null pronouns is the repeated name topic anaphor. We discuss the implications of these findings for theories of anaphor processing.

Coevolutionary dynamics of aspiration and strategy in spatial repeated public goods games

NASA Astrophysics Data System (ADS)

Wu, Te; Fu, Feng; Wang, Long

2018-06-01

The evolutionary dynamics remain largely unknown for spatial populations where individuals are more likely to interact repeatedly. Under this settings, individuals can make their decisions to cooperate or not based on the decisions previously adopted by others in their neighborhoods. Using repeated public goods game, we construct a spatial model and use a statistical physics approach to study the coevolutionary dynamics of aspiration and strategy. Individuals each have an aspiration towards the groups they are involved. According to the outcome of each group, individuals have assessment of whether their aspirations are satisfied. If satisfied, they cooperate next round. Otherwise, they switch to defecting. Results show threshold phenomenon for harsh collective dilemma: cooperators sticking to high levels of aspiration can prevail over defectors, while cooperators with other levels are invariably wiped out. When the collective dilemma is relaxed, cooperation is greatly facilitated by inducing a high level of diversity of aspiration. Snapshots further show the spatial patterns of how this coevolutionary process leads to the emergence of an optimal solution associated with aspiration level, whose corresponding strategy are most prevalent. This optimal solution lies in one and the highest aspiration level allowed, and depends on the intensity of the social dilemma. By removing the memory effect, our results also confirm that repeated interactions can promote cooperation, but to a limited degree.

Evaluation of wheelchair resistive forces during straight and turning trajectories across different wheelchair configurations using free-wheeling coast-down test.

PubMed

Lin, Jui-Te; Huang, Morris; Sprigle, Stephen

2015-01-01

The purpose of this study was to develop a simple approach to evaluate resistive frictional forces acting on manual wheelchairs (MWCs) during straight and turning maneuvers. Using a dummy-occupied MWC, decelerations were measured via axle-mounted encoders during a coast-down protocol that included straight trajectories and fixed-wheel turns. Eight coast-down trials were conducted to test repeatability and repeated on separate days to evaluate reliability. Without changing the inertia of the MWC system, three tire inflations were chosen to evaluate the sensitivity in discerning deceleration differences using effect sizes. The technique was also deployed to investigate the effect of different MWC masses and weight distributions on resistive forces. Results showed that the proposed coast-down technique had good repeatability and reliability in measuring decelerations and had good sensitivity in discerning differences in tire inflation, especially during turning. The results also indicated that increased loading on drive wheels reduced resistive losses in straight trajectories while increasing resistive losses during turning. During turning trajectories, the presence of tire scrub contributes significantly to the amount of resistive force. Overall, this new coast-down technique demonstrates satisfactory repeatability and sensitivity for detecting deceleration changes during straight and turning trajectories, indicating that it can be used to evaluate resistive loss of different MWC configurations and maneuvers.

Comparison of Eyemetrics and Orbscan automated method to determine horizontal corneal diameter

PubMed Central

Venkataraman, Arvind; Mardi, Sapna K; Pillai, Sarita

2010-01-01

Purpose: To compare horizontal corneal diameter measurements using the Orbscan Eyemetrics function and Orbscan corneal topographer. Materials and Methods: Seventy-three eyes of 37 patients were included in the study. In all cases, the automated white-to-white (WTW) measurements were obtained using Orbscan by two observers. Using the Eyemetrics function, the WTW was measured manually by the same observers from limbus to limbus using the digital caliper passing through the five point corneal reflections on the Orbscan real image. The data was analyzed using SPSS software for correlation, reliability and inter-rater repeatability. Results: The mean horizontal corneal diameter was 11.74 ± 0.32mm (SD) with the Orbscan and 11.92 ± 0.33mm (SD) with Eyemetrics Software-based measurement. A good positive correlation (Spearman r = 0.720, P = 0.026) was found between these two measurements. The coefficient of inter-rater repeatability was 0.89 for the Orbscan and 0.94 for the Eyemetrics software measurements on the anterior segment images. The Bland and Altman analysis showed large limits of agreement between Orbscan WTW and Eyemetrics WTW measurements. The intra-session repeatability scores for repeat measurements for the Orbscan WTW and Eyemetrics measurements were good. Conclusion: Eyemetrics can be used to measure WTW and the Eyemetrics measured WTW was longer than the WTW measured by Orbscan. PMID:20413925

Clostridium difficile Infection

MedlinePlus

... These drugs can make your infection worse. Certain probiotics, or “good bacteria,” may help prevent repeat C. ... Your Doctor Drugs, Procedures & Devices Over-the-counter Products Procedures & Devices Prescription Medicines Health Tools Dictionary Symptom ...

The human genome as "common good".

PubMed

Vesto, Aurora

2017-07-01

Objectivity of rights must be rebuilt in a dimension not only structural but also functional, despite being a "thing" that exactly repeats itself, it differs depending on what the person intended to make.

Assessment of different methods to estimate bovine colostrum quality on farm.

PubMed

Bartens, M-C; Drillich, M; Rychli, K; Iwersen, M; Arnholdt, T; Meyer, L; Klein-Jöbstl, D

2016-09-01

To evaluate two different hydrometers and an optical and a digital Brix refractometer for the assessment of bovine colostrum quality, in terms of accuracy and precision compared with the measurement of IgG concentrations using radial immunodiffusion (RID), and to evaluate the reliability and repeatability of the Brix refractometers. To determine reliability and repeatability, 145 colostrum samples were tested by two independent observers twice, using the optical and digital Brix refractometers. A further 193 colostrum samples from Holstein cows were collected on one commercial dairy farm at first milking and tested with two hydrometers and an optical and digital Brix refractometer. An aliquot of each sample was frozen for RID measurement of IgG concentrations and samples were classified as poor (≤50 g IgG/L) or good (>50 g IgG/L) quality colostrum. Intraclass correlation coefficients (ICC) were used to determine inter- and intra-observer reliability and repeatability. Optimised cut-off values for the four devices were determined using receiver operating characteristics (ROC) analysis with the RID results as the reference. Using these cut-offs, sensitivities and specificities for determining good quality colostrum were calculated. The ICC for inter-observer reliability was 0.98 for the optical Brix refractometer, and for intra-observer repeatability was 0.97 and 0.98 for the optical and the digital Brix refractometers, respectively. For the 193 colostrum samples, 67 (34.7%) had concentrations of IgG ≤50 g/L determined by RID. Optimised cut-off values evaluated by ROC analysis were higher for all devices compared with manufacturer reference or previously published values. Using these values, the sensitivities for the two hydrometers, and the optical and the digital Brix refractometers were 0.73, 0.71, 0.56 and 0.79, respectively; specificities were 0.72, 0.61, 0.90 and 0.69, respectively. The Brix refractometers provided the most accurate assessment of colostrum quality of the devices evaluated, and demonstrated excellent precision in terms of repeatability. To provide optimal health for newborn calves, a sufficient intake of good quality colostrum is essential. The Brix refractometers provide rapid, convenient tools for classification of colostrum quality.

2D transition metal carbide MXene as a robust biosensing platform for enzyme immobilization and ultrasensitive detection of phenol.

PubMed

Wu, Lingxia; Lu, Xianbo; Dhanjai; Wu, Zhong-Shuai; Dong, Yanfeng; Wang, Xiaohui; Zheng, Shuanghao; Chen, Jiping

2018-06-01

MXene-Ti 3 C 2 , as a new class of two-dimensional (2D) transition metal carbides (or nitrides), has been synthesized by exfoliating pristine Ti 3 AlC 2 phases with hydrofluoric acid. The SEM and XRD images show that the resultant MXene possesses a graphene-like 2D nanostructure. and the surface of MXene has been partially terminated with -OH, thus providing a favorable microenvironment for enzyme immobilization and retaining their bioactivity and stability. Considering the unique metallic conductivity, biocompatibility and good dispersion in aqueous phase, the as-prepared MXene was explored as a new matrix to immobilize tyrosinase (a model enzyme) for fabricating a mediator-free biosensor for ultrasensitive and rapid detection of phenol. The varying electrochemical measurements were used to investigate the electrochemical performance of MXene-based tyrosinase biosensors. The results revealed that the direct electron transfer between tyrosinase and electrode could be easily achieved via a surface-controlled electrochemical process. The fabricated MXene-based tyrosinase biosensors exhibited good analytical performance over a wide linear range from 0.05 to 15.5 μmol L -1 , with a low detection limit of 12 nmol L -1 and a sensitivity of 414.4 mA M -1 . The proposed biosensing approach also demonstrated good repeatability, reproducibility, long-term stability and high recovery for phenol detection in real water samples. With those excellent performances, MXene with graphene-like structure is proved to be a robust and versatile electrochemical biosensing platform for enzyme-based biosensors and biocatalysis, and has wide potential applications in biomedical detection and environmental analysis. Copyright © 2018. Published by Elsevier B.V.

Determination of phthalate esters in drinking water and edible vegetable oil samples by headspace solid phase microextraction using graphene/polyvinylchloride nanocomposite coated fiber coupled to gas chromatography-flame ionization detector.

PubMed

Amanzadeh, Hatam; Yamini, Yadollah; Moradi, Morteza; Asl, Yousef Abdossalmi

2016-09-23

In the current study, a graphene/polyvinylchloride nanocomposite was successfully coated on a stainless steel substrate by a simple dip coating process and used as a novel headspace solid phase microextraction (HS-SPME) fiber for the extraction of phthalate esters (PEs) from drinking water and edible vegetable oil samples. The prepared SPME fibers exhibited high extractability for PEs (due to the dominant role of π-π stacking interactions and hydrophobic effects) yielding good sensitivity and precision when followed by a gas chromatograph with a flame ionization detector (GC-FID). The optimization strategy of the extraction process was carried out using the response surface method based on a central composite design. The developed method gave a low limit of detection (0.06-0.08μgL(-1)) and good linearity (0.2-100μgL(-1)) for the determination of the PEs under the optimized conditions (extraction temperature, 70±1°C; extraction time, 35min; salt concentration, 30% w/v; stirring rate, 900rpm; desorption temperature, 230°C; and desorption time, 4min) whereas the repeatability and fiber-to-fiber reproducibility were in the range 6.1-7.8% and 8.9-10.2%, respectively. Finally, the proposed method was successfully applied to the analysis of PEs in drinking water and edible oil samples with good recoveries (87-112%) and satisfactory precisions (RSDs<8.3%), indicating the absence of matrix effects in the proposed HS-SPME method. Copyright © 2016 Elsevier B.V. All rights reserved.

Design and development of amperometric biosensor for the detection of lead and mercury ions in water matrix-a permeability approach.

PubMed

Gumpu, Manju Bhargavi; Krishnan, Uma Maheswari; Rayappan, John Bosco Balaguru

2017-07-01

Intake of water contaminated with lead (Pb 2+ ) and mercury (Hg 2+ ) ions leads to various toxic effects and health issues. In this context, an amperometric urease inhibition-based biosensor was developed to detect Pb 2+ and Hg 2+ ions in water matrix. The modified Pt/CeO 2 /urease electrode was fabricated by immobilizing CeO 2 nanoparticles and urease using a semi-permeable adsorption layer of nafion. With urea as a substrate, urease catalytic activity was examined through cyclic voltammetry. Further, maximum amperometric inhibitive response of the modified Pt/CeO 2 /urease electrode was observed in the presence of Pb 2+ and Hg 2+ ions due to the urease inhibition at specific potentials of -0.03 and 0 V, respectively. The developed sensor exhibited a detection limit of 0.019 ± 0.001 μM with a sensitivity of 89.2 × 10 -3  μA μM -1 for Pb 2+ ions. A detection limit of 0.018 ± 0.003 with a sensitivity of 94.1 × 10 -3  μA μM -1 was achieved in detecting Hg 2+ ions. The developed biosensor showed a fast response time (<1 s) with a linear range of 0.5-2.2 and 0.02-0.8 μM for Pb 2+ and Hg 2+ ions, respectively. The modified electrode offered a good stability for 20 days with a good repeatability and reproducibility. The developed sensor was used to detect Pb 2+ and Hg 2+ ions contaminating Cauvery river water and the observed results were in good co-ordination with atomic absorption spectroscopic data.

TiO2 Nanorod Arrays Based Self-Powered UV Photodetector: Heterojunction with NiO Nanoflakes and Enhanced UV Photoresponse.

PubMed

Gao, Yanyan; Xu, Jianping; Shi, Shaobo; Dong, Hong; Cheng, Yahui; Wei, Chengtai; Zhang, Xiaosong; Yin, Shougen; Li, Lan

2018-04-04

The self-powered ultraviolet photodetectors (UV PDs) have attracted increasing attention due to their potential applications without consuming any external power. It is important to obtain the high-performance self-powered UV PDs by a simple method for the practical application. Herein, TiO 2 nanorod arrays (NRs) were synthesized by hydrothermal method, which were integrated with p-type NiO nanoflakes to realize a high performance pn heterojunction for the efficient UV photodetection. TiO x thin film can improve the morphological and carrier transport properties of TiO 2 NRs and decrease the surface and defect states, resulting in the enhanced photocurrent of the devices. NiO/TiO 2 nanostructural heterojunctions show excellent rectifying characteristics (rectification ratio of 2.52 × 10 4 and 1.45 × 10 5 for NiO/TiO 2 NRs and NiO/TiO 2 NRs/TiO x , respectively) with a very low reverse saturation current. The PDs based on the heterojunctions exhibit good spectral selectivity, high photoresponsivity, and fast response and recovery speeds without external applied bias under the weak light radiation. The devices demonstrate good stability and repeatability under UV light radiation. The self-powered performance could be attributed to the proper built-in electric field of the heterojunction. TiO 2 NRs and NiO nanoflakes construct the well-aligned energy-band structure. The enhanced responsivity and detectivity for the devices with TiO x thin films is related to the increased interfacial charge separation efficiency, reduced carrier recombination, and relatively good electron transport of TiO 2 NRs.

76 FR 4929 - Agency Information Collection Activities: Entry of Articles for Exhibition.

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-27

... Activities: Entry of Articles for Exhibition. AGENCY: U.S. Customs and Border Protection (CBP), Department of... requirement concerning the Entry of Articles for Exhibition (19 CFR 147.11(c)). This request for comment is...: Title: Entry of Articles for Exhibition. OMB Number: 1651-0037. Form Number: None. Abstract: Goods...

Structural insights into the anti-HIV activity of the Oscillatoria agardhii agglutinin homolog lectin family.

PubMed

Koharudin, Leonardus M I; Kollipara, Sireesha; Aiken, Christopher; Gronenborn, Angela M

2012-09-28

Oscillatoria agardhii agglutinin homolog (OAAH) proteins belong to a recently discovered lectin family. All members contain a sequence repeat of ~66 amino acids, with the number of repeats varying among different family members. Apart from data for the founding member OAA, neither three-dimensional structures, information about carbohydrate binding specificities, nor antiviral activity data have been available up to now for any other members of the OAAH family. To elucidate the structural basis for the antiviral mechanism of OAAHs, we determined the crystal structures of Pseudomonas fluorescens and Myxococcus xanthus lectins. Both proteins exhibit the same fold, resembling the founding family member, OAA, with minor differences in loop conformations. Carbohydrate binding studies by NMR and x-ray structures of glycan-lectin complexes reveal that the number of sugar binding sites corresponds to the number of sequence repeats in each protein. As for OAA, tight and specific binding to α3,α6-mannopentaose was observed. All the OAAH proteins described here exhibit potent anti-HIV activity at comparable levels. Altogether, our results provide structural details of the protein-carbohydrate interaction for this novel lectin family and insights into the molecular basis of their HIV inactivation properties.

40 CFR 1065.320 - Fuel-flow calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... manufacturer's instructions and use good engineering judgment to repeat the calibration. (b) You may also develop a procedure based on a chemical balance of carbon or oxygen in engine exhaust. (c) You may remove...

40 CFR 1065.320 - Fuel-flow calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... manufacturer's instructions and use good engineering judgment to repeat the calibration. (b) You may also develop a procedure based on a chemical balance of carbon or oxygen in engine exhaust. (c) You may remove...

40 CFR 1065.320 - Fuel-flow calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... manufacturer's instructions and use good engineering judgment to repeat the calibration. (b) You may also develop a procedure based on a chemical balance of carbon or oxygen in engine exhaust. (c) You may remove...

40 CFR 1065.320 - Fuel-flow calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... manufacturer's instructions and use good engineering judgment to repeat the calibration. (b) You may also develop a procedure based on a chemical balance of carbon or oxygen in engine exhaust. (c) You may remove...

40 CFR 1065.320 - Fuel-flow calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... manufacturer's instructions and use good engineering judgment to repeat the calibration. (b) You may also develop a procedure based on a chemical balance of carbon or oxygen in engine exhaust. (c) You may remove...

12 CFR 308.132 - Assessment of penalties.

Code of Federal Regulations, 2010 CFR

2010-01-01

... good faith of the bank or official, the gravity of the violation, the history of previous violations... bank's delinquency is lengthy or the bank has been delinquent repeatedly in making or publishing its...

Genetic Contributors to Intergenerational CAG Repeat Instability in Huntington’s Disease Knock-In Mice

PubMed Central

Neto, João Luís; Lee, Jong-Min; Afridi, Ali; Gillis, Tammy; Guide, Jolene R.; Dempsey, Stephani; Lager, Brenda; Alonso, Isabel; Wheeler, Vanessa C.; Pinto, Ricardo Mouro

2017-01-01

Huntington’s disease (HD) is a neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in exon 1 of the HTT gene. Longer repeat sizes are associated with increased disease penetrance and earlier ages of onset. Intergenerationally unstable transmissions are common in HD families, partly underlying the genetic anticipation seen in this disorder. HD CAG knock-in mouse models also exhibit a propensity for intergenerational repeat size changes. In this work, we examine intergenerational instability of the CAG repeat in over 20,000 transmissions in the largest HD knock-in mouse model breeding datasets reported to date. We confirmed previous observations that parental sex drives the relative ratio of expansions and contractions. The large datasets further allowed us to distinguish effects of paternal CAG repeat length on the magnitude and frequency of expansions and contractions, as well as the identification of large repeat size jumps in the knock-in models. Distinct degrees of intergenerational instability were observed between knock-in mice of six background strains, indicating the occurrence of trans-acting genetic modifiers. We also found that lines harboring a neomycin resistance cassette upstream of Htt showed reduced expansion frequency, indicative of a contributing role for sequences in cis, with the expanded repeat as modifiers of intergenerational instability. These results provide a basis for further understanding of the mechanisms underlying intergenerational repeat instability. PMID:27913616

Genetic Contributors to Intergenerational CAG Repeat Instability in Huntington's Disease Knock-In Mice.

PubMed

Neto, João Luís; Lee, Jong-Min; Afridi, Ali; Gillis, Tammy; Guide, Jolene R; Dempsey, Stephani; Lager, Brenda; Alonso, Isabel; Wheeler, Vanessa C; Pinto, Ricardo Mouro

2017-02-01

Huntington's disease (HD) is a neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in exon 1 of the HTT gene. Longer repeat sizes are associated with increased disease penetrance and earlier ages of onset. Intergenerationally unstable transmissions are common in HD families, partly underlying the genetic anticipation seen in this disorder. HD CAG knock-in mouse models also exhibit a propensity for intergenerational repeat size changes. In this work, we examine intergenerational instability of the CAG repeat in over 20,000 transmissions in the largest HD knock-in mouse model breeding datasets reported to date. We confirmed previous observations that parental sex drives the relative ratio of expansions and contractions. The large datasets further allowed us to distinguish effects of paternal CAG repeat length on the magnitude and frequency of expansions and contractions, as well as the identification of large repeat size jumps in the knock-in models. Distinct degrees of intergenerational instability were observed between knock-in mice of six background strains, indicating the occurrence of trans-acting genetic modifiers. We also found that lines harboring a neomycin resistance cassette upstream of Htt showed reduced expansion frequency, indicative of a contributing role for sequences in cis, with the expanded repeat as modifiers of intergenerational instability. These results provide a basis for further understanding of the mechanisms underlying intergenerational repeat instability. Copyright © 2017 by the Genetics Society of America.

Roles of CUB and LDL receptor class A domain repeats of a transmembrane serine protease matriptase in its zymogen activation

PubMed Central

Inouye, Kuniyo; Tomoishi, Marie; Yasumoto, Makoto; Miyake, Yuka; Kojima, Kenji; Tsuzuki, Satoshi; Fushiki, Tohru

2013-01-01

Matriptase is a type II transmembrane serine protease containing two complement proteases C1r/C1s–urchin embryonic growth factor–bone morphogenetic protein domains (CUB repeat) and four low-density lipoprotein receptor class A domains (LDLRA repeat). The single-chain zymogen of matriptase has been found to exhibit substantial protease activity, possibly causing its own activation (i.e. conversion to a disulfide-linked two-chain fully active form), although the activation seems to be mediated predominantly by two-chain molecules. Our aim was to assess the roles of CUB and LDLRA repeats in zymogen activation. Transient expression studies of soluble truncated constructs of recombinant matriptase in COS-1 cells showed that the CUB repeat had an inhibitory effect on zymogen activation, possibly because it facilitated the interaction of two-chain molecules with a matriptase inhibitor, hepatocyte growth factor activator inhibitor type-1. By contrast, the LDLRA repeat had a promoting effect on zymogen activation. The effect of the LDLRA repeat seems to reflect its ability to increase zymogen activity. The proteolytic activities were higher in pseudozymogen forms of recombinant matriptase containing the LDLRA repeat than in a pseudozymogen without the repeat. Our findings provide new insights into the roles of these non-catalytic domains in the generation of active matriptase. PMID:23038671

[Establishment of Automation System for Detection of Alcohol in Blood].

PubMed

Tian, L L; Shen, Lei; Xue, J F; Liu, M M; Liang, L J

2017-02-01

To establish an automation system for detection of alcohol content in blood. The determination was performed by automated workstation of extraction-headspace gas chromatography （HS-GC）. The blood collection with negative pressure, sealing time of headspace bottle and sample needle were checked and optimized in the abstraction of automation system. The automatic sampling was compared with the manual sampling. The quantitative data obtained by the automated workstation of extraction-HS-GC for alcohol was stable. The relative differences of two parallel samples were less than 5%. The automated extraction was superior to the manual extraction. A good linear relationship was obtained at the alcohol concentration range of 0.1-3.0 mg/mL （ r ≥0.999） with good repeatability. The method is simple and quick, with more standard experiment process and accurate experimental data. It eliminates the error from the experimenter and has good repeatability, which can be applied to the qualitative and quantitative detections of alcohol in blood. Copyright© by the Editorial Department of Journal of Forensic Medicine

S-adenosyl methionine (SAM) attenuates the development of tolerance to analgesic activity of morphine in rats.

PubMed

Katyal, Jatinder; Kumar, Hemant; Joshi, Dinesh; Gupta, Yogendra Kumar

2017-04-03

Development of tolerance to analgesic effect, on chronic administration of morphine, limits its clinical usefulness in pain management. S-adenosyl methionine (SAM) used for arthritis and approved as a supplement in many countries including United States was evaluated for reducing morphine tolerance. Male 'Wistar' rats were used. The analgesic activity was determined using tail flick analgesiometer (Columbus Instruments, USA). Rats given morphine (7mg/kg), intraperitoneally (i.p.), once daily for 5days developed tolerance to analgesic effect. To evaluate the effect of SAM on morphine tolerance, SAM 800mg/kg was administered orally (p.o.), 45min prior to each dose of morphine. The analgesic activity of SAM and opioidergic component in its activity was also evaluated. Co-administration of morphine and SAM reversed morphine tolerance. SAM exhibited analgesic effect after repeated administration which was reversed by naloxone administration. Since safety of SAM on chronic use is documented it can be a good option in morphine tolerance. Role in drug addiction and withdrawal should also be evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

A real-time posture monitoring method for rail vehicle bodies based on machine vision

NASA Astrophysics Data System (ADS)

Liu, Dongrun; Lu, Zhaijun; Cao, Tianpei; Li, Tian

2017-06-01

Monitoring vehicle operation conditions has become significantly important in modern high-speed railway systems. However, the operational impact of monitoring the roll angle of vehicle bodies has principally been limited to tilting trains, while few studies have focused on monitoring the running posture of vehicle bodies during operation. We propose a real-time posture monitoring method to fulfil real-time monitoring requirements, by taking rail surfaces and centrelines as detection references. In realising the proposed method, we built a mathematical computational model based on space coordinate transformations to calculate attitude angles of vehicles in operation and vertical and lateral vibration displacements of single measuring points. Moreover, comparison and verification of reliability between system and field results were conducted. Results show that monitoring of the roll angles of car bodies obtained through the system exhibit variation trends similar to those converted from the dynamic deflection of bogie secondary air springs. The monitoring results of two identical conditions were basically the same, highlighting repeatability and good monitoring accuracy. Therefore, our monitoring results were reliable in reflecting posture changes in running railway vehicles.

Amperometric L-lysine biosensor based on carboxylated multiwalled carbon nanotubes-SnO2 nanoparticles-graphene composite

NASA Astrophysics Data System (ADS)

Kaçar, Ceren; Erden, Pınar Esra; Kılıç, Esma

2017-10-01

A novel matrix, carboxylated multiwalled carbon nanotubes-tin oxide nanoparticles-graphene-chitosan (c-MWCNTs-SnO2-GR-CS) composite, was prepared for biosensor construction. Lysine oxidase (LOx) enzyme was immobilized covalently on the surface of c-MWCNTs-GR-SnO2-CS composite modified glassy carbon electrode (GCE) using N-ethyl-N‧-(3-dimethyaminopropyl) carbodiimide (EDC) and N-hydroxyl succinimide (NHS). Effects of electrode composition and buffer pH on biosensor response were investigated to optimize the working conditions. The biosensor exhibited wide linear range (9.9 × 10-7 M-1.6 × 10-4 M), low detection limit (1.5 × 10-7 M), high sensitivity (55.20 μA mM-1 cm-2) and fast amperometric response (<25 s) at +0.70 V vs. Ag/AgCl. With good repeatability and long-term stability, the c-MWCNTs-SnO2-GR-CS based biosensor offered an alternative for L-lysine biosensing. The practical applicability of the biosensor in two dietary supplements has also been addressed.

Electrochemical biosensor based on glucose oxidase encapsulated within enzymatically synthesized poly(1,10-phenanthroline-5,6-dione).

PubMed

Ciftci, Hakan; Oztekin, Yasemin; Tamer, Ugur; Ramanaviciene, Almira; Ramanavicius, Arunas

2014-11-01

This study is focused on the investigation of electrocatalytic effect of glucose oxidase (GOx) immobilized on the graphite rod (GR) electrode. The enzyme modified electrode was prepared by encapsulation of immobilized GOx within enzymatically formed poly(1,10-phenanthroline-5,6-dione) (pPD) film. The electrochemical responses of such enzymatic electrode (pPD/GOx/GR) vs. different glucose concentrations were examined chronoamperometrically in acetate-phosphate buffer solution (A-PBS), pH 6.0, under aerobic or anaerobic conditions. Amperometric signals of the pPD/GOx/GR electrode exhibited well-defined hyperbolic dependence upon glucose concentration. Amperometric signals at 100mM of glucose were 41.17 and 32.27 μA under aerobic and anaerobic conditions, respectively. Amperometric signals of the pPD/GOx/GR electrode decreased by 6% within seven days. The pPD/GOx/GR electrode showed excellent selectivity in the presence of dopamine and uric acid. Furthermore it had a good reproducibility and repeatability with standard deviation of 9.4% and 8.0%, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

Miniaturized pH Sensors Based on Zinc Oxide Nanotubes/Nanorods

PubMed Central

Fulati, Alimujiang; Ali, Syed M.Usman; Riaz, Muhammad; Amin, Gul; Nur, Omer; Willander, Magnus

2009-01-01

ZnO nanotubes and nanorods grown on gold thin film were used to create pH sensor devices. The developed ZnO nanotube and nanorod pH sensors display good reproducibility, repeatability and long-term stability and exhibit a pH-dependent electrochemical potential difference versus an Ag/AgCl reference electrode over a large dynamic pH range. We found the ZnO nanotubes provide sensitivity as high as twice that of the ZnO nanorods, which can be ascribed to the fact that small dimensional ZnO nanotubes have a higher level of surface and subsurface oxygen vacancies and provide a larger effective surface area with higher surface-to-volume ratio as compared to ZnO nanorods, thus affording the ZnO nanotube pH sensor a higher sensitivity. Experimental results indicate ZnO nanotubes can be used in pH sensor applications with improved performance. Moreover, the ZnO nanotube arrays may find potential application as a novel material for measurements of intracellular biochemical species within single living cells. PMID:22291545

Underresolved absorption spectroscopy of OH radicals in flames using broadband UV LEDs

NASA Astrophysics Data System (ADS)

White, Logan; Gamba, Mirko

2018-04-01

A broadband absorption spectroscopy diagnostic based on underresolution of the spectral absorption lines is evaluated for the inference of species mole fraction and temperature in combustion systems from spectral fitting. The approach uses spectrally broadband UV light emitting diodes and leverages low resolution, small form factor spectrometers. Through this combination, the method can be used to develop high precision measurement sensors. The challenges of underresolved spectroscopy are explored and addressed using spectral derivative fitting, which is found to generate measurements with high precision and accuracy. The diagnostic is demonstrated with experimental measurements of gas temperature and OH mole fraction in atmospheric air/methane premixed laminar flat flames. Measurements exhibit high precision, good agreement with 1-D flame simulations, and high repeatability. A newly developed model of uncertainty in underresolved spectroscopy is applied to estimate two-dimensional confidence regions for the measurements. The results of the uncertainty analysis indicate that the errors in the outputs of the spectral fitting procedure are correlated. The implications of the correlation between uncertainties for measurement interpretation are discussed.

Understanding “revolving door” patients in general practice: a qualitative study

PubMed Central

2014-01-01

Background ‘Revolving door’ patients in general practice are repeatedly removed from general practitioners’ (GP) lists. This paper reports a qualitative portion of the first mixed methods study of these marginalised patients. Methods We conducted qualitative semi-structured interviews with six practitioner services staff and six GPs in Scotland, utilizing Charmazian grounded theory to characterise ‘revolving door’ patients and their impact from professionals’ perspectives. Results ‘Revolving door’ patients were reported as having three necessary characteristics; they had unreasonable expectations, exhibited inappropriate behaviours and had unmet health needs. A range of boundary breaches were reported too when ‘revolving door’ patients interacted with NHS staff. Conclusions We utilise the ‘sensitising concepts’ of legitimacy by drawing on literature about ‘good and bad’ patients and ‘dirty work designations.’ We relate these to the core work of general practice and explore the role that medical and moral schemas have in how health service professionals understand and work with ‘revolving door’ patients. We suggest this may have wider relevance for the problem doctor patient relationship literature. PMID:24524363

Low Hysteresis Carbon Nanotube Transistors Constructed via a General Dry-Laminating Encapsulation Method on Diverse Surfaces.

PubMed

Yang, Yi; Wang, Zhongwu; Xu, Zeyang; Wu, Kunjie; Yu, Xiaoqin; Chen, Xiaosong; Meng, Yancheng; Li, Hongwei; Qiu, Song; Jin, Hehua; Li, Liqiang; Li, Qingwen

2017-04-26

Electrical hysteresis in carbon nanotube thin-film transistor (CNTTFT) due to surface adsorption of H 2 O/O 2 is a severe obstacle for practical applications. The conventional encapsulation methods based on vacuum-deposited inorganic materials or wet-coated organic materials have some limitations. In this work, we develop a general and highly efficient dry-laminating encapsulation method to reduce the hysteresis of CNTTFTs, which may simultaneously realize the construction and encapsulation of CNTTFT. Furthermore, by virtue of dry procedure and wide compatibility of PMMA, this method is suitable for the construction of CNTTFT on diverse surface including both inorganic and organic dielectric materials. Significantly, the dry-encapsulated CNTTFT exhibits very low or even negligible hysteresis with good repeatability and air stability, which is greatly superior to the nonencapsulated and wet-encapsulated CNTTFT with spin-coated PMMA. The dry-laminating encapsulation strategy, a kind of technological innovation, resolves a significant problem of CNTTFT and therefore will be promising in facile transferring and packaging the CNT films for high-performance optoelectronic devices.

Fabrication of hydrogel-coated single conical nanochannels exhibiting controllable ion rectification characteristics.

PubMed

Wang, Linlin; Zhang, Huacheng; Yang, Zhe; Zhou, Jianjun; Wen, Liping; Li, Lin; Jiang, Lei

2015-03-07

Heterogeneous nanochannel materials that endow new functionalities different to the intrinsic properties of two original nanoporous materials have wide potential applications in nanofluidics, energy conversion, and biosensors. Herein, we report novel, interesting hydrogel-composited nanochannel devices with regulatable ion rectification characteristics. The heterogeneous nanochannel devices were constructed by selectively coating the tip side, base side, or both sides of a single conical nanochannel membrane with thin agar hydrogel layers. The tunable ion current rectification of the nanochannels in the three different coating states was systematically demonstrated by current-voltage (I-V) curves. The asymmetric ionic transport property of the conical nanochannel was further strengthened in the tip-coating state and weakened in the base-coating state, whereas the conical nanochannel showed nearly symmetric ionic transport in the dual-coating state. Repeated experiments presented insight into the good stability and reversibility of the three coating states of the hydrogel-nanochannel-integrated systems. This work, as an example, may provide a new strategy to further design and develop multifunctional gel-nanochannel heterogeneous smart porous nanomaterials.

Characterization of nucleosides and nucleobases in natural Cordyceps by HILIC-ESI/TOF/MS and HILIC-ESI/MS.

PubMed

Zhao, Heng-Qiang; Wang, Xiao; Li, Hong-Mei; Yang, Bin; Yang, Hong-Jun; Huang, Luqi

2013-08-15

A method combining hydrophilic interaction chromatography (HILIC) and electrospray ionization mass spectrometry (ESI-MS) was developed for the characterization and determination of natural Cordyceps. Separation was achieved on a Waters Xbridge Amide column with gradient elution. Identification of 15 target nucleosides and nucleobases was based on retention time, UV spectra and mass measurements of the protonated molecules ([M+H]⁺) and main fragment ions (ESI-TOF/MS). Eight non-target compounds were tentatively identified by ESI-TOF/MS. The 15 target compounds were quantified by HILIC-ESI-MS/MS using time-programmed selective ion monitoring or multiple reaction monitoring in positive-ion mode under optimized mass conditions. This technique showed good linearity, repeatability and recovery. This approach was also successfully implemented in the analysis of nucleosides and nucleobases in 12 batches of natural Cordyceps samples that were collected from different regions in China. The developed HILIC-ESI-MS method exhibited clear advantages in identifying and determining highly polar bioactive components in Cordyceps, as well as their quality control.

Hydrothermal growth of CuO nanoleaf structures, and their mercuric ion detection application.

PubMed

Ibupoto, Z H; Khun, K; Willander, M

2014-09-01

Mercury is the hazardous heavy metal ion for the environment and the human being therefore its determination is very important and herein we describe the development of mercury ion sensor on the CuO nanoleaf like nanostructures using cetyltrimethylammonium bromide (CTAB) surfactant as template for the growth by hydrothermal growth method. Scanning electron microscopy and X-ray diffraction study has shown high density and good crystal quality of the fabricated CuO nanostructures respectively. The presented mercury ion sensor has detected the wide range of 1.0 x 10(-7) to 1.0 x 10(-1) M mercury ion concentrations with an acceptable Nernstian behaviour and a sensitivity of 30.1 ± 0.6 mV/decade. The proposed mercury ion sensor exhibited low detection limit of 1.0 x 10(-8) M and also a fast response time of less than 5 s. In addition, the presented mercury ion sensor has shown an excellent repeatability, reproducibility, stability and selectivity. Moreover, the mercury ion selective electrode based on CuO nanoleaves was tested as an indicator electrode in the potentiometric titration.

Mutation Is a Sufficient and Robust Predictor of Genetic Variation for Mitotic Spindle Traits in Caenorhabditis elegans

PubMed Central

Farhadifar, Reza; Ponciano, José Miguel; Andersen, Erik C.; Needleman, Daniel J.; Baer, Charles F.

2016-01-01

Different types of phenotypic traits consistently exhibit different levels of genetic variation in natural populations. There are two potential explanations: Either mutation produces genetic variation at different rates or natural selection removes or promotes genetic variation at different rates. Whether mutation or selection is of greater general importance is a longstanding unresolved question in evolutionary genetics. We report mutational variances (VM) for 19 traits related to the first mitotic cell division in Caenorhabditis elegans and compare them to the standing genetic variances (VG) for the same suite of traits in a worldwide collection C. elegans. Two robust conclusions emerge. First, the mutational process is highly repeatable: The correlation between VM in two independent sets of mutation accumulation lines is ∼0.9. Second, VM for a trait is a good predictor of VG for that trait: The correlation between VM and VG is ∼0.9. This result is predicted for a population at mutation–selection balance; it is not predicted if balancing selection plays a primary role in maintaining genetic variation. PMID:27334268

Graphene oxide as sensitive layer in Love-wave surface acoustic wave sensors for the detection of chemical warfare agent simulants.

PubMed

Sayago, Isabel; Matatagui, Daniel; Fernández, María Jesús; Fontecha, José Luis; Jurewicz, Izabela; Garriga, Rosa; Muñoz, Edgar

2016-02-01

A Love-wave device with graphene oxide (GO) as sensitive layer has been developed for the detection of chemical warfare agent (CWA) simulants. Sensitive films were fabricated by airbrushing GO dispersions onto Love-wave devices. The resulting Love-wave sensors detected very low CWA simulant concentrations in synthetic air at room temperature (as low as 0.2 ppm for dimethyl-methylphosphonate, DMMP, a simulant of sarin nerve gas, and 0.75 ppm for dipropylene glycol monomethyl ether, DPGME, a simulant of nitrogen mustard). High responses to DMMP and DPGME were obtained with sensitivities of 3087 and 760 Hz/ppm respectively. Very low limit of detection (LOD) values (9 and 40 ppb for DMMP and DPGME, respectively) were calculated from the achieved experimental data. The sensor exhibited outstanding sensitivity, good linearity and repeatability to all simulants tested. The detection mechanism is here explained in terms of hydrogen bonding formation between the tested CWA simulants and GO. Copyright © 2015 Elsevier B.V. All rights reserved.

Inter- and intraobserver repeatability of the Salford Gait Tool: an observation-based clinical gait assessment tool.

PubMed

Toro, Brigitte; Nester, Christopher J; Farren, Pauline C

2007-03-01

To evaluate the inter- and intraobserver repeatability of the Salford Gait Tool (SF-GT), a new observation-based gait assessment tool for evaluating sagittal plane cerebral palsy (CP) gait. Masked comparative evaluation. University in the United Kingdom. A convenience sample of 23 pediatric physical therapists with varying degrees of clinical experience recruited from the Greater Manchester area. Participants viewed videotapes of the sagittal plane gait of 13 children and used the SF-GT to analyze their 13 different gait styles on 2 occasions. Eleven children had hemiplegic, diplegic, or quadriplegic CP and 2 were neurologically intact. Inter- and intraobserver repeatability of hip, knee, and ankle joint positions at 6 different phases of the gait cycle. The SF-GT demonstrated good interobserver (77%) and intraobserver (75%) repeatability. We have established that the SF-GT is a repeatable clinical assessment tool with which to guide the diagnosis, treatment planning, and evaluation of interventions by pediatric physical therapists of sagittal plane gait deviations in CP.

REVERSAL LEARNING SET AND FUNCTIONAL EQUIVALENCE IN CHILDREN WITH AND WITHOUT AUTISM

PubMed Central

Lionello-DeNolf, Karen M.; McIlvane, William J.; Canovas, Daniela S.; de Souza, Deisy G.; Barros, Romariz S.

2009-01-01

To evaluate whether children with and without autism could exhibit (a) functional equivalence in the course of yoked repeated-reversal training and (b) reversal learning set, 6 children, in each of two experiments, were exposed to simple discrimination contingencies with three sets of stimuli. The discriminative functions of the set members were yoked and repeatedly reversed. In Experiment 1, all the children (of preschool age) showed gains in the efficiency of reversal learning across reversal problems and behavior that suggested formation of functional equivalence. In Experiment 2, 3 nonverbal children with autism exhibited strong evidence of reversal learning set and 2 showed evidence of functional equivalence. The data suggest a possible relationship between efficiency of reversal learning and functional equivalence test outcomes. Procedural variables may prove important in assessing the potential of young or nonverbal children to classify stimuli on the basis of shared discriminative functions. PMID:20186287

The structure of cell adhesion molecule uvomorulin. Insights into the molecular mechanism of Ca2+-dependent cell adhesion.

PubMed Central

Ringwald, M; Schuh, R; Vestweber, D; Eistetter, H; Lottspeich, F; Engel, J; Dölz, R; Jähnig, F; Epplen, J; Mayer, S

1987-01-01

We have determined the amino acid sequence of the Ca2+-dependent cell adhesion molecule uvomorulin as it appears on the cell surface. The extracellular part of the molecule exhibits three internally repeated domains of 112 residues which are most likely generated by gene duplication. Each of the repeated domains contains two highly conserved units which could represent putative Ca2+-binding sites. Secondary structure predictions suggest that the putative Ca2+-binding units are located in external loops at the surface of the protein. The protein sequence exhibits a single membrane-spanning region and a cytoplasmic domain. Sequence comparison reveals extensive homology to the chicken L-CAM. Both uvomorulin and L-CAM are identical in 65% of their entire amino acid sequence suggesting a common origin for both CAMs. Images Fig. 1. Fig. 4. Fig. 7. PMID:3501370

Limitations on quantum key repeaters.

PubMed

Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

2015-04-23

A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol.

Fatigue-Induced Balance Impairment in Young Soccer Players

PubMed Central

Pau, Massimiliano; Ibba, Gianfranco; Attene, Giuseppe

2014-01-01

Context: Although balance is generally recognized to be an important feature in ensuring good performance in soccer, its link with functional performance remains mostly unexplored, especially in young athletes. Objective: To investigate changes in balance induced by fatigue for unipedal and bipedal static stances in young soccer players. Design: Crossover study. Setting: Biomechanics laboratory and outdoor soccer field. Patients or Other Participants: Twenty-one male soccer players (age = 14.5 ± 0.2 years, height = 164.5 ± 5.6 cm, mass = 56.8 ± 6.8 kg). Intervention(s): Static balance was assessed with postural-sway analysis in unipedal and bipedal upright stance before and after a fatigue protocol consisting of a repeated sprint ability (RSA) test (2 × 15-m shuttle sprint interspersed with 20 seconds of passive recovery, repeated 6 times). Main Outcome Measure(s): On the basis of the center-of-pressure (COP) time series acquired during the experimental tests, we measured sway area, COP path length, and COP maximum displacement and velocity in the anteroposterior and mediolateral directions. Results: Fatigue increased all sway values in bipedal stance and all values except COP velocity in the mediolateral direction in unipedal stance. Fatigue index (calculated on the basis of RSA performance) was positively correlated with fatigue/rest sway ratio for COP path length and COP velocity in the anteroposterior and mediolateral directions for nondominant single-legged stance. Conclusions: Fatigued players exhibited reduced performance of the postural-control system. Participants with better performance in the RSA test appeared less affected by balance impairment, especially in single-legged stance. PMID:24568227

Reusable electrochemical sensor for bisphenol A based on ionic liquid functionalized conducting polymer platform.

PubMed

Wang, Jhe-Yi; Su, Ya-Ling; Wu, Bo-Hao; Cheng, Shu-Hua

2016-01-15

The toxicity of bisphenol A (BPA) has attracted considerable attention, and the reported electrochemical sensors for BPA need further improvement in reusability due to serious surface fouling. In this study, a composite film is designed aiming to provide both an accurate and repeatable platform for BPA determination. The conducting poly(3,4-ethylenedioxythiophene) film (PEDOT) and ionic liquid 1-butyl-3-methylimidazolium bromide (BMIMBr) were modified onto screen-printed carbon electrodes (SPCE) by electropolymerization and drop/spin methods, respectively. The surface characteristics of the composite film were characterized by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and surface water contact angle experiments. The composite film-modified electrodes exhibited a linear response to BPA in the range of 0.1-500µM in pH 7.0 phosphate buffer solution (PBS) under optimized flow-injection amperometry. The method sensitivity and detection limit (S/N=3) were 0.2661μA μM(-1) (2.419μA μM(-1)cm(-2)) and 0.02µM, respectively. A relative standard deviation of 1.95% was obtained for 77 successive measurements of 10µM BPA, and the repeatability outperformed previously reported work. The proposed method was applied to detect BPA released from plastic water bottles using the standard addition method, and satisfactory recoveries were obtained. The electrochemical assay was validated by comparison with the chromatographic method, and the results showed good agreement between the two methods. Copyright © 2015 Elsevier B.V. All rights reserved.

Agreement and repeatability of objective systems for assessment of the tear film.

PubMed

Fernández, Joaquín; Rodríguez-Vallejo, Manuel; Martínez, Javier; Tauste, Ana; García-Montesinos, Javier; Piñero, David P

2018-04-18

To assess the agreement and repeatability of two objective systems for measuring the tear film stability. Retrospective analysis of the tear film stability of 99 healthy right eyes measured with a videokeratoscope (VK) and the Optical Quality Analysis System (OQAS, Visiometrics). Two consecutive measures were taken with both systems, with an interval of 10 min between them. Variables included in the study were first and mean non-invasive break-up times (NIBUT and MNIBUT) measured with VK, and mean and standard deviation of the optical scattering index (OSIm and OSIsd) measured with OQAS. The agreement and repeatability of grading scales provided by both devices were also evaluated using the Cohen's k with quadratic weights. The Ocular Surface Disease index (OSDI) questionnaire was also passed out to all subjects. Correlations and associations between subjective and objective metrics were analyzed. Significant differences were found between consecutive measurements of NIBUT (p = 0.04) and MNIBUT (p = 0.01), but not for OSIm (p = 0.11) and OSIsd (p = 0.50). Grading scales resulted in fair (k = 0.20) or poor agreement (k = 0.04) between systems depending if the first or second trial was considered. The repeatability of the grading scale was good for OQAS (k = 0.59) and fair for VK (k = 0.37). No significant correlations or associations were found between OSDI and any of the metrics obtained with both devices (p ≥ 0.36). The two devices evaluated cannot be used interchangeably for the assessment of tear film stability. Good intrasession repeatability was obtained for tear film grading of the OQAS whereas it was fair for VK.

Insulin autoimmune syndrome caused by an adhesive skin patch containing loxoprofen-sodium.

PubMed

Okazaki-Sakai, Satoko; Yoshimoto, Sachiko; Yagi, Kunimasa; Wakasugi, Takanobu; Takeda, Yoshiyu; Yamagishi, Masakazu

2013-01-01

A 62-year-old woman complained of repeated hypoglycemic events. A 75 g oral glucose tolerance test (75 gOGTT) showed a marked increase in the plasma insulin level and impaired glucose tolerance. The patient exhibited a high titer of plasma anti-insulin autoantibodies. Her diagnosis was insulin autoimmune syndrome (IAS). Following the cessation of loxoprofen-sodium (LOXs), she experienced no further hypoglycemic episodes. However, the hypoglycemic attacks recurred following the accidental readministration of LOXs in an adhesive skin patch. Considering the changes in the titer of anti-insulin autoantibodies, the repeated 75 gOGTT and the repeated Scatchard analysis, we determined LOXs to be the cause of the IAS and evaluated the characteristics of the autoantibodies.

Awareness during drowsiness: dynamics and electrophysiological correlates

NASA Technical Reports Server (NTRS)

Makeig, S.; Jung, T. P.; Sejnowski, T. J.

2000-01-01

During drowsy periods, performance on tasks requiring continuous attention becomes intermittent. Previously, we have reported that during drowsy periods of intermittent performance, 7 of 10 participants performing an auditory detection task exhibited episodes of non-responding lasting about 18 s (Makeig & Jung, 1996). Further, the time patterns of these episodes were repeated precisely in subsequent sessions. The 18-s cycles were accompanied by counterbalanced power changes within two frequency bands in the vertex EEG (near 4 Hz and circa 40 Hz). In the present experiment, performance patterns and concurrent EEG spectra were examined in four participants performing a continuous visuomotor compensatory tracking task in 15-20 minute bouts during a 42-hour sleep deprivation study. During periods of good performance, participants made compensatory trackball movements about twice per second, attempting to keep a target disk near a central ring. Autocorrelations of time series representing the distance of the target disk from the ring centre showed that during periods of poor performance marked near-18-s cycles in performance again appeared. There were phases of poor or absent performance accompanied by an increase in EEG power that was largest at 3-4 Hz. These studies show that in drowsy humans, opening and closing of the gates of behavioural awareness is marked not by the appearance of (12-14 Hz) sleep spindles, but by prominent EEG amplitude changes in the low theta band. Further, both EEG and behavioural changes during drowsiness often exhibit stereotyped 18-s cycles.

Complete biodegradation of chlorpyrifos by engineered Pseudomonas putida cells expressing surface-immobilized laccases.

PubMed

Liu, Jin; Tan, Luming; Wang, Jing; Wang, Zhiyong; Ni, Hong; Li, Lin

2016-08-01

The long-term abuse use of chlorpyrifos-like pesticides in agriculture and horticulture has resulted in significant soil or water contamination and a worldwide ecosystem threat. In this study, the ability of a solvent-tolerant bacterium, Pseudomonas putida MB285, with surface-displayed bacterial laccase, to biodegrade chlorpyrifos was investigated. The results of compositional analyses of the degraded products demonstrate that the engineered MB285 was capable of completely eliminating chlorpyrifos via direct biodegradation, as determined by high-performance liquid chromatography and gas chromatography-mass spectrometry assays. Two intermediate metabolites, namely 3,5,6-trichloro-2-pyridinol (TCP) and diethyl phosphate, were temporarily detectable, verifying the joint and stepwise degradation of chlorpyrifos by surface laccases and certain cellular enzymes, whereas the purified free laccase incompletely degraded chlorpyrifos into TCP. The degradation reaction can be conducted over a wide range of pH values (2-7) and temperatures (5-55 °C) without the need for Cu(2+). Bioassays using Caenorhabditis elegans as an indicator organism demonstrated that the medium was completely detoxified of chlorpyrifos by degradation. Moreover, the engineered cells exhibited a high capacity of repeated degradation and good performance in continuous degradation cycles, as well as a high capacity to degrade real effluents containing chlorpyrifos. Therefore, the developed system exhibited a high degradation capacity and performance and constitutes an improved approach to address chlorpyrifos contamination in chlorpyrifos-remediation practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Urban Stream Food Web: Synthesis of Recent Investigations and a Look Ahead

EPA Science Inventory

Research has repeatedly demonstrated declines in assemblage richness, diversity, and biotic integrity with increasing urbanization. Benthic macroinvertebrates are among the most widely studied organisms and have exhibited consistent responses to urbanization. Some recent macroinv...

Disposable MoS2-Arrayed MALDI MS Chip for High-Throughput and Rapid Quantification of Sulfonamides in Multiple Real Samples.

PubMed

Zhao, Yaju; Tang, Minmin; Liao, Qiaobo; Li, Zhoumin; Li, Hui; Xi, Kai; Tan, Li; Zhang, Mei; Xu, Danke; Chen, Hong-Yuan

2018-04-27

In this work, we demonstrate, for the first time, the development of a disposable MoS 2 -arrayed matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) chip combined with an immunoaffinity enrichment method for high-throughput, rapid, and simultaneous quantitation of multiple sulfonamides (SAs). The disposable MALDI MS chip was designed and fabricated by MoS 2 array formation on a commercial indium tin oxide (ITO) glass slide. A series of SAs were analyzed, and clear deprotonated signals were obtained in negative-ion mode. Compared with MoS 2 -arrayed commercial steel plate, the prepared MALDI MS chip exhibited comparable LDI efficiency, providing a good alternative and disposable substrate for MALDI MS analysis. Furthermore, internal standard (IS) was previously deposited onto the MoS 2 array to simplify the experimental process for MALDI MS quantitation. 96 sample spots could be analyzed within 10 min in one single chip to perform quantitative analysis, recovery studies, and real foodstuff detection. Upon targeted extraction and enrichment by antibody conjugated magnetic beads, five SAs were quantitatively determined by the IS-first method with the linear range of 0.5-10 ng/mL ( R 2 > 0.990). Good recoveries and repeatability were obtained for spiked pork, egg, and milk samples. SAs in several real foodstuffs were successfully identified and quantified. The developed method may provide a promising tool for the routine analysis of antibiotic residues in real samples.

Rubidium extraction from seawater brine by an integrated membrane distillation-selective sorption system.

PubMed

Naidu, Gayathri; Jeong, Sanghyun; Johir, Md Abu Hasan; Fane, Anthony G; Kandasamy, Jaya; Vigneswaran, Saravanamuthu

2017-10-15

The ultimate goal of seawater reverse osmosis (SWRO) brine management is to achieve minimal liquid discharge while recovering valuable resources. The suitability of an integrated system of membrane distillation (MD) with sorption for the recovery of rubidium (Rb + ) and simultaneous SWRO brine volume reduction has been evaluated for the first time. Polymer encapsulated potassium copper hexacyanoferrate (KCuFC(PAN)) sorbent exhibited a good selectivity for Rb + sorption with 10-15% increment at 55 °C (Langmuir Q max  = 125.11 ± 0.20 mg/g) compared to at 25 °C (Langmuir Q max  = 108.71 ± 0.20 mg/g). The integrated MD-KCuFC(PAN) system with periodic membrane cleaning, enabled concentration of SWRO brine to a volume concentration factor (VCF) of 2.9 (65% water recovery). A stable MD permeate flux was achieved with good quality permeate (conductivity of 15-20 μS/cm). Repeated cycles of MD-KCuFC(PAN) sorption with SWRO brine enabled the extraction of 2.26 mg Rb + from 12 L of brine (equivalent to 1.9 kg of Rb/day, or 0.7 tonne/yr from a plant producing 10,000 m 3 /day brine). KCuFC(PAN) showed a high regeneration and reuse capacity. NH 4 Cl air stripping followed by resorcinol formaldehyde (RF) resin filtration enabled to recover Rb + from the desorbed solution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of beer volatiles by polymeric imidazolium-solid phase microextraction coatings: Synthesis and characterization of polymeric imidazolium ionic liquids.

PubMed

González-Álvarez, Jaime; Blanco-Gomis, Domingo; Arias-Abrodo, Pilar; Pello-Palma, Jairo; Ríos-Lombardía, Nicolás; Busto, Eduardo; Gotor-Fernández, Vicente; Gutiérrez-Álvarez, María Dolores

2013-08-30

Two polymeric ionic liquids, 3-(but-3″-en-1″-yl)-1-[2'-hydroxycyclohexyl]-1H-imidazol-3-ium bis(trifluoromethanesulfonyl)imide (IL-1) and 1-(2'-hydroxycyclohexyl)-3-(4″-vinylbenzyl)-1H-imidazol-3-ium bis(trifluoromethylsulfonyl)imide (IL-2), have been synthesized by a free radical polymerization reaction and used as coatings for solid-phase microextraction (SPME). These new fibers exhibit good film stability, high thermal stability (270-290°C) and long lifetimes, and are used for the extraction of volatile compounds in lemon beer using gas chromatography separation and flame ionization detection. The scanning electron micrographs of the fiber surface revealed a polymeric ionic liquid (PIL) film, which is distributed homogeneously on the fiber. The developed PIL fiber showed good linearity between 50 and 2000μg/L with regression coefficients in the range of 0.996-0.999. The relative standard deviations (RSD) obtained in the peak area were found to vary between 1% and 12%, which assured that adequate repeatability was achieved. The spiked recoveries for three beer samples ranged from 78.4% to 123.6%. Experimental design has been employed in the optimization of extraction factors and robustness assessment. The polymeric IL-1 butenyl fiber showed a greater efficiency compared to the PDMS-DVB (65μm) and CAR-PDMS (75μm) for the extraction of all of the analytes studied. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Successful comeback of the single-dose live oral cholera vaccine CVD 103-HgR.

PubMed

Herzog, Christian

2016-01-01

Effective and easy to administer cholera vaccines are in need more than ever, for at risk populations and travellers alike. In many parts of the world cholera is still endemic, causing outbreaks and constituting repeatedly serious public health problems. The oral live cholera vaccine CVD 103-HgR (Orochol, Mutachol), the first genetically modified organism (GMO) used as vaccine, was in its time (launched 1993, Switzerland) the ideal cholera vaccine: single-dose, protective efficacy of 80-100% against moderate to severe cholera, acting within 8 days and exhibiting excellent safety, indiscernible from placebo. However, there were strong headwinds: In the 1990s the indication for cholera vaccines was generally downplayed by experts and in 1997 the European Commission called for a moratorium of GMOs which blocked the registration in the European Union. Thus, demand for this vaccine remained low and in 2003 it was taken off the market for economic reasons. After a decade in obscurity it (Vaxchora) has resurfaced again, now produced in the U.S. and equipped with a U.S. FDA license (June 10, 2016). What had happened? This commentary gives a critical account of an almost unbelievable string of misadventures, emerging adverse circumstances and man-made failures which nearly killed this single-dose live oral cholera vaccine. The good news is that patience and persistence lead to success in the end, allowing good science to prevail for the benefit of those in need. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evolutionary conservation of sequence and secondary structures inCRISPR repeats

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

Kunin, Victor; Sorek, Rotem; Hugenholtz, Philip

Clustered Regularly Interspaced Palindromic Repeats (CRISPRs) are a novel class of direct repeats, separated by unique spacer sequences of similar length, that are present in {approx}40% of bacterial and all archaeal genomes analyzed to date. More than 40 gene families, called CRISPR-associated sequences (CAS), appear in conjunction with these repeats and are thought to be involved in the propagation and functioning of CRISPRs. It has been proposed that the CRISPR/CAS system samples, maintains a record of, and inactivates invasive DNA that the cell has encountered, and therefore constitutes a prokaryotic analog of an immune system. Here we analyze CRISPR repeatsmore » identified in 195 microbial genomes and show that they can be organized into multiple clusters based on sequence similarity. All individual repeats in any given cluster were inferred to form characteristic RNA secondary structure, ranging from non-existent to pronounced. Stable secondary structures included G:U base pairs and exhibited multiple compensatory base changes in the stem region, indicating evolutionary conservation and functional importance. We also show that the repeat-based classification corresponds to, and expands upon, a previously reported CAS gene-based classification including specific relationships between CRISPR and CAS subtypes.« less

Instrumenting Beliefs in Threshold Public Goods

PubMed Central

2016-01-01

Understanding the causal impact of beliefs on contributions in Threshold Public Goods (TPGs) is particularly important since the social optimum can be supported as a Nash Equilibrium and best-response contributions are a function of beliefs. Unfortunately, investigations of the impact of beliefs on behavior are plagued with endogeneity concerns. We create a set of instruments by cleanly and exogenously manipulating beliefs without deception. Tests indicate that the instruments are valid and relevant. Perhaps surprisingly, we fail to find evidence that beliefs are endogenous in either the one-shot or repeated-decision settings. TPG allocations are determined by a base contribution and beliefs in a one shot-setting. In the repeated-decision environment, once we instrument for first-round allocations, we find that second-round allocations are driven equally by beliefs and history. Moreover, we find that failing to instrument prior decisions overstates their importance. PMID:26859492

Volunteering as Red Queen Mechanism for Cooperation in Public Goods Games

NASA Astrophysics Data System (ADS)

Hauert, Christoph; De Monte, Silvia; Hofbauer, Josef; Sigmund, Karl

2002-05-01

The evolution of cooperation among nonrelated individuals is one of the fundamental problems in biology and social sciences. Reciprocal altruism fails to provide a solution if interactions are not repeated often enough or groups are too large. Punishment and reward can be very effective but require that defectors can be traced and identified. Here we present a simple but effective mechanism operating under full anonymity. Optional participation can foil exploiters and overcome the social dilemma. In voluntary public goods interactions, cooperators and defectors will coexist. We show that this result holds under very diverse assumptions on population structure and adaptation mechanisms, leading usually not to an equilibrium but to an unending cycle of adjustments (a Red Queen type of evolution). Thus, voluntary participation offers an escape hatch out of some social traps. Cooperation can subsist in sizable groups even if interactions are not repeated, defectors remain anonymous, players have no memory, and assortment is purely random.

Polymeric Ionic Networks with High Charge Density: Solid-like Electrolytes in Lithium Metal Batteries

DOE PAGES

Zhang, Pengfei; Li, Mingtao; Jiang, Xueguang; ...

2015-11-02

Polymerized ionic networks (PINs) with six ion pairs per repeating unit are synthesized by nucleophilic-substitution-mediated polymerization or radical polymerization of monomers bearing six 1-vinylimidazolium cations. PIN-based solid-like electrolytes show good ionic conductivities (up to 5.32 × 10 -3 S cm -1 at 22 °C), wide electrochemical stability windows (up to 5.6 V), and good interfacial compatibility with the electrodes.

Spectral and Temporal Processing in Rat Posterior Auditory Cortex

PubMed Central

Pandya, Pritesh K.; Rathbun, Daniel L.; Moucha, Raluca; Engineer, Navzer D.; Kilgard, Michael P.

2009-01-01

The rat auditory cortex is divided anatomically into several areas, but little is known about the functional differences in information processing between these areas. To determine the filter properties of rat posterior auditory field (PAF) neurons, we compared neurophysiological responses to simple tones, frequency modulated (FM) sweeps, and amplitude modulated noise and tones with responses of primary auditory cortex (A1) neurons. PAF neurons have excitatory receptive fields that are on average 65% broader than A1 neurons. The broader receptive fields of PAF neurons result in responses to narrow and broadband inputs that are stronger than A1. In contrast to A1, we found little evidence for an orderly topographic gradient in PAF based on frequency. These neurons exhibit latencies that are twice as long as A1. In response to modulated tones and noise, PAF neurons adapt to repeated stimuli at significantly slower rates. Unlike A1, neurons in PAF rarely exhibit facilitation to rapidly repeated sounds. Neurons in PAF do not exhibit strong selectivity for rate or direction of narrowband one octave FM sweeps. These results indicate that PAF, like nonprimary visual fields, processes sensory information on larger spectral and longer temporal scales than primary cortex. PMID:17615251

Long interspersed repeated DNA (LINE) causes polymorphism at the rat insulin 1 locus.

PubMed

Lakshmikumaran, M S; D'Ambrosio, E; Laimins, L A; Lin, D T; Furano, A V

1985-09-01

The insulin 1, but not the insulin 2, locus is polymorphic (i.e., exhibits allelic variation) in rats. Restriction enzyme analysis and hybridization studies showed that the polymorphic region is 2.2 kilobases upstream of the insulin 1 coding region and is due to the presence or absence of an approximately 2.7-kilobase repeated DNA element. DNA sequence determination showed that this DNA element is a member of a long interspersed repeated DNA family (LINE) that is highly repeated (greater than 50,000 copies) and highly transcribed in the rat. Although the presence or absence of LINE sequences at the insulin 1 locus occurs in both the homozygous and heterozygous states, LINE-containing insulin 1 alleles are more prevalent in the rat population than are alleles without LINEs. Restriction enzyme analysis of the LINE-containing alleles indicated that at least two versions of the LINE sequence may be present at the insulin 1 locus in different rats. Either repeated transposition of LINE sequences or gene conversion between the resident insulin 1 LINE and other sequences in the genome are possible explanations for this.

Repeatability of DTI-based skeletal muscle fiber tracking

PubMed Central

Heemskerk, Anneriet M.; Sinha, Tuhin K.; Wilson, Kevin J.; Ding, Zhaohua; Damon, Bruce M.

2015-01-01

Diffusion tensor imaging (DTI)-based muscle fiber tracking enables the measurement of muscle architectural parameters, such as pennation angle (θ) and fiber tract length (Lft), throughout the entire muscle. Little is known, however, about the repeatability of either the muscle architectural measures or the underlying diffusion measures. Therefore, the goal of this study was to investigate the repeatability of DTI fiber tracking-based measurements and θ and Lft. Four DTI acquisitions were performed on two days that allowed for between acquisition, within day, and between day analyses. The eigenvalues and fractional anisotropy were calculated at the maximum cross-sectional area of, and fiber tracking was performed in, the tibialis anterior muscle of nine healthy subjects. The between acquisitions condition had the highest repeatability for the DTI indices and the architectural parameters. The overall inter class correlation coefficients (ICC’s) were greater than 0.6 for both θ and Lft and the repeatability coefficients were θ <10.2° and Lft < 50 mm. In conclusion, under the experimental and data analysis conditions used, the repeatability of the diffusion measures is very good and repeatability of the architectural measurements is acceptable. Therefore, this study demonstrates the feasibility for longitudinal studies of alterations in muscle architecture using DTI-based fiber tracking, under similar noise conditions and with similar diffusion characteristics. PMID:20099372

CRISPR Detection From Short Reads Using Partial Overlap Graphs.

PubMed

Ben-Bassat, Ilan; Chor, Benny

2016-06-01

Clustered regularly interspaced short palindromic repeats (CRISPR) are structured regions in bacterial and archaeal genomes, which are part of an adaptive immune system against phages. CRISPRs are important for many microbial studies and are playing an essential role in current gene editing techniques. As such, they attract substantial research interest. The exponential growth in the amount of bacterial sequence data in recent years enables the exploration of CRISPR loci in more and more species. Most of the automated tools that detect CRISPR loci rely on fully assembled genomes. However, many assemblers do not handle repetitive regions successfully. The first tool to work directly on raw sequence data is Crass, which requires reads that are long enough to contain two copies of the same repeat. We present a method to identify CRISPR repeats from raw sequence data of short reads. The algorithm is based on an observation differentiating CRISPR repeats from other types of repeats, and it involves a series of partial constructions of the overlap graph. This enables us to avoid many of the difficulties that assemblers face, as we merely aim to identify the repeats that belong to CRISPR loci. A preliminary implementation of the algorithm shows good results and detects CRISPR repeats in cases where other existing tools fail to do so.

A novel magnet based 3D printed marker wand as basis for repeated in-shoe multi segment foot analysis: a proof of concept.

PubMed

Eerdekens, Maarten; Staes, Filip; Pilkington, Thomas; Deschamps, Kevin

2017-01-01

Application of in-shoe multi-segment foot kinematic analyses currently faces a number of challenges, including: (i) the difficulty to apply regular markers onto the skin, (ii) the necessity for an adequate shoe which fits various foot morphologies and (iii) the need for adequate repeatability throughout a repeated measure condition. The aim of this study therefore was to design novel magnet based 3D printed markers for repeated in-shoe measurements while using accordingly adapted modified shoes for a specific multi-segment foot model. Multi-segment foot kinematics of ten participants were recorded and kinematics of hindfoot, midfoot and forefoot were calculated. Dynamic trials were conducted to check for intra and inter-session repeatability when combining novel markers and modified shoes in a repeated measures design. Intraclass correlation coefficients were calculated to determine reliability. Both repeatability and reliability were proven to be good to excellent with maximum joint angle deviations of 1.11° for intra-session variability and 1.29° for same-day inter-session variability respectively and ICC values of >0.91. The novel markers can be reliably used in future research settings using in-shoe multi-segment foot kinematic analyses with multiple shod conditions.

Androgen receptor repeat length polymorphism associated with male-to-female transsexualism.

PubMed

Hare, Lauren; Bernard, Pascal; Sánchez, Francisco J; Baird, Paul N; Vilain, Eric; Kennedy, Trudy; Harley, Vincent R

2009-01-01

There is a likely genetic component to transsexualism, and genes involved in sex steroidogenesis are good candidates. We explored the specific hypothesis that male-to-female transsexualism is associated with gene variants responsible for undermasculinization and/or feminization. Specifically, we assessed the role of disease-associated repeat length polymorphisms in the androgen receptor (AR), estrogen receptor beta (ERbeta), and aromatase (CYP19) genes. Subject-control analysis included 112 male-to-female transsexuals and 258 non-transsexual males. Associations and interactions were investigated between CAG repeat length in the AR gene, CA repeat length in the ERbeta gene, and TTTA repeat length in the CYP19 gene and male-to-female transsexualism. A significant association was identified between transsexualism and the AR allele, with transsexuals having longer AR repeat lengths than non-transsexual male control subjects (p=.04). No associations for transsexualism were evident in repeat lengths for CYP19 or ERbeta genes. Individuals were then classified as short or long for each gene polymorphism on the basis of control median polymorphism lengths in order to further elucidate possible combined effects. No interaction associations between the three genes and transsexualism were identified. This study provides evidence that male gender identity might be partly mediated through the androgen receptor.

Androgen Receptor Repeat Length Polymorphism Associated with Male-to-Female Transsexualism

PubMed Central

Hare, Lauren; Bernard, Pascal; Sánchez, Francisco J.; Baird, Paul N.; Vilain, Eric; Kennedy, Trudy; Harley, Vincent R.

2012-01-01

Background There is a likely genetic component to transsexualism, and genes involved in sex steroidogenesis are good candidates. We explored the specific hypothesis that male-to-female transsexualism is associated with gene variants responsible for undermasculinization and/or feminization. Specifically, we assessed the role of disease-associated repeat length polymorphisms in the androgen receptor (AR), estrogen receptor β (ERβ), and aromatase (CYP19) genes. Methods Subject-control analysis included 112 male-to-female transsexuals and 258 non-transsexual males. Associations and interactions were investigated between CAG repeat length in the AR gene, CA repeat length in the ERβ gene, and TTTA repeat length in the CYP19 gene and male-to-female transsexualism. Results A significant association was identified between transsexualism and the AR allele, with transsexuals having longer AR repeat lengths than non-transsexual male control subjects (p = .04). No associations for transsexualism were evident in repeat lengths for CYP19 or ERβ genes. Individuals were then classified as short or long for each gene polymorphism on the basis of control median polymorphism lengths in order to further elucidate possible combined effects. No interaction associations between the three genes and transsexualism were identified. Conclusions This study provides evidence that male gender identity might be partly mediated through the androgen receptor. PMID:18962445

The repetition of large-earthquake ruptures.

PubMed Central

Sieh, K

1996-01-01

This survey of well-documented repeated fault rupture confirms that some faults have exhibited a "characteristic" behavior during repeated large earthquakes--that is, the magnitude, distribution, and style of slip on the fault has repeated during two or more consecutive events. In two cases faults exhibit slip functions that vary little from earthquake to earthquake. In one other well-documented case, however, fault lengths contrast markedly for two consecutive ruptures, but the amount of offset at individual sites was similar. Adjacent individual patches, 10 km or more in length, failed singly during one event and in tandem during the other. More complex cases of repetition may also represent the failure of several distinct patches. The faults of the 1992 Landers earthquake provide an instructive example of such complexity. Together, these examples suggest that large earthquakes commonly result from the failure of one or more patches, each characterized by a slip function that is roughly invariant through consecutive earthquake cycles. The persistence of these slip-patches through two or more large earthquakes indicates that some quasi-invariant physical property controls the pattern and magnitude of slip. These data seem incompatible with theoretical models that produce slip distributions that are highly variable in consecutive large events. Images Fig. 3 Fig. 7 Fig. 9 PMID:11607662

The Chromatin Remodeler Isw1 Prevents CAG Repeat Expansions During Transcription in Saccharomyces cerevisiae

PubMed Central

Koch, Melissa R.; House, Nealia C. M.; Cosetta, Casey M.; Jong, Robyn M.; Salomon, Christelle G.; Joyce, Cailin E.; Philips, Elliot A.; Su, Xiaofeng A.; Freudenreich, Catherine H.

2018-01-01

CAG/CTG trinucleotide repeats are unstable sequences that are difficult to replicate, repair, and transcribe due to their structure-forming nature. CAG repeats strongly position nucleosomes; however, little is known about the chromatin remodeling needed to prevent repeat instability. In a Saccharomyces cerevisiae model system with CAG repeats carried on a YAC, we discovered that the chromatin remodeler Isw1 is required to prevent CAG repeat expansions during transcription. CAG repeat expansions in the absence of Isw1 were dependent on both transcription-coupled repair (TCR) and base-excision repair (BER). Furthermore, isw1∆ mutants are sensitive to methyl methanesulfonate (MMS) and exhibit synergistic MMS sensitivity when combined with BER or TCR pathway mutants. We conclude that CAG expansions in the isw1∆ mutant occur during a transcription-coupled excision repair process that involves both TCR and BER pathways. We observed increased RNA polymerase II (RNAPII) occupancy at the CAG repeat when transcription of the repeat was induced, but RNAPII binding did not change in isw1∆ mutants, ruling out a role for Isw1 remodeling in RNAPII progression. However, nucleosome occupancy over a transcribed CAG tract was altered in isw1∆ mutants. Based on the known role of Isw1 in the reestablishment of nucleosomal spacing after transcription, we suggest that a defect in this function allows DNA structures to form within repetitive DNA tracts, resulting in inappropriate excision repair and repeat-length changes. These results establish a new function for Isw1 in directly maintaining the chromatin structure at the CAG repeat, thereby limiting expansions that can occur during transcription-coupled excision repair. PMID:29305386

Measurement system with high accuracy for laser beam quality.

PubMed

Ke, Yi; Zeng, Ciling; Xie, Peiyuan; Jiang, Qingshan; Liang, Ke; Yang, Zhenyu; Zhao, Ming

2015-05-20

Presently, most of the laser beam quality measurement system collimates the optical path manually with low efficiency and low repeatability. To solve these problems, this paper proposed a new collimated method to improve the reliability and accuracy of the measurement results. The system accuracy controlled the position of the mirror to change laser beam propagation direction, which can realize the beam perpendicularly incident to the photosurface of camera. The experiment results show that the proposed system has good repeatability and the measuring deviation of M² factor is less than 0.6%.

Negative differential resistance in GaN tunneling hot electron transistors

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

Yang, Zhichao; Nath, Digbijoy; Rajan, Siddharth

Room temperature negative differential resistance is demonstrated in a unipolar GaN-based tunneling hot electron transistor. Such a device employs tunnel-injected electrons to vary the electron energy and change the fraction of reflected electrons, and shows repeatable negative differential resistance with a peak to valley current ratio of 7.2. The device was stable when biased in the negative resistance regime and tunable by changing collector bias. Good repeatability and double-sweep characteristics at room temperature show the potential of such device for high frequency oscillators based on quasi-ballistic transport.

Photopic Negative Response Obtained Using a Handheld Electroretinogram Device: Determining the Optimal Measure and Repeatability

PubMed Central

Wu, Zhichao; Hadoux, Xavier; Hui, Flora; Sarossy, Marc G.; Crowston, Jonathan G.

2016-01-01

Purpose To determine the measure of the photopic negative response (PhNR) of the full-field electroretinogram (ERG) that exhibits the optimal level of test-retest repeatability, and examine its repeatability under different conditions using a handheld, nonmydriatic ERG system and self-adhering skin electrodes. Methods Multiple ERG recordings (using 200 sweeps each) were performed in both eyes of 20 normal participants at two different sessions to compare its coefficient of repeatability (CoR; where 95% of the test-retest difference is expected to lie) between different PhNR measures and under different testing conditions (within and between examiners, and between sessions). Results The ratio between the PhNR trough to b-wave peak and b-wave peak to a-wave trough amplitude (PhNR/B ratio) exhibited the lowest CoR relative to its effective dynamic range (30 ± 4%) when including three recordings. There were no significant changes in the PhNR/B ratio over seven measurements (4 right and 3 left eyes) at either session (P ≥ 0.100), or significant difference in its CoR between different testing conditions (P = 0.314). Conclusion The PhNR/B ratio was the measure that minimized variability, and its measurements using a novel handheld ERG system with self-adhering skin electrodes and the protocols described in this study were comparable under different testing conditions and over multiple recordings. Translational Relevance The PhNR can be measured for clinical and research purposes using a simple-to-implement technique that is consistent within and between visits, and also between examiners. PMID:27540494

The Role of Face Familiarity in Eye Tracking of Faces by Individuals with Autism Spectrum Disorders

PubMed Central

Dawson, Geraldine; Webb, Sara; Murias, Michael; Munson, Jeffrey; Panagiotides, Heracles; Aylward, Elizabeth

2010-01-01

It has been shown that individuals with autism spectrum disorders (ASD) demonstrate normal activation in the fusiform gyrus when viewing familiar, but not unfamiliar faces. The current study utilized eye tracking to investigate patterns of attention underlying familiar versus unfamiliar face processing in ASD. Eye movements of 18 typically developing participants and 17 individuals with ASD were recorded while passively viewing three face categories: unfamiliar non-repeating faces, a repeating highly familiar face, and a repeating previously unfamiliar face. Results suggest that individuals with ASD do not exhibit more normative gaze patterns when viewing familiar faces. A second task assessed facial recognition accuracy and response time for familiar and novel faces. The groups did not differ on accuracy or reaction times. PMID:18306030

Pediatric Autoimmune Disorders Associated with Streptococcal Infections and Tourette's Syndrome in Preclinical Studies

PubMed Central

Spinello, Chiara; Laviola, Giovanni; Macrì, Simone

2016-01-01

Accumulating evidence suggests that Tourette's Syndrome (TS) – a multifactorial pediatric disorder characterized by the recurrent exhibition of motor tics and/or vocal utterances – can partly depend on immune dysregulation provoked by early repeated streptococcal infections. The natural and adaptive antibody-mediated reaction to streptococcus has been proposed to potentially turn into a pathological autoimmune response in vulnerable individuals. Specifically, in conditions of increased permeability of the blood brain barrier (BBB), streptococcus-induced antibodies have been proposed to: (i) reach neuronal targets located in brain areas responsible for motion control; and (ii) contribute to the exhibition of symptoms. This theoretical framework is supported by indirect evidence indicating that a subset of TS patients exhibit elevated streptococcal antibody titers upon tic relapses. A systematic evaluation of this hypothesis entails preclinical studies providing a proof of concept of the aforementioned pathological sequelae. These studies shall rest upon individuals characterized by a vulnerable immune system, repeatedly exposed to streptococcus, and carefully screened for phenotypes isomorphic to the pathological signs of TS observed in patients. Preclinical animal models may thus constitute an informative, useful tool upon which conducting targeted, hypothesis-driven experiments. In the present review we discuss the available evidence in preclinical models in support of the link between TS and pediatric autoimmune neuropsychiatric disorders associated with streptococcus infections (PANDAS), and the existing gaps that future research shall bridge. Specifically, we report recent preclinical evidence indicating that the immune responses to repeated streptococcal immunizations relate to the occurrence of behavioral and neurological phenotypes reminiscent of TS. By the same token, we discuss the limitations of these studies: limited evidence of behavioral phenotypes isomorphic to tics and scarce knowledge about the immunological phenomena favoring the transition from natural adaptive immunity to pathological outcomes. PMID:27445678

Is Forced Swimming Immobility a Good Endpoint for Modeling Negative Symptoms of Schizophrenia? - Study of Sub-Anesthetic Ketamine Repeated Administration Effects.

PubMed

Neves, Gilda; Borsoi, Milene; Antonio, Camila B; Pranke, Mariana A; Betti, Andresa H; Rates, Stela M K

2017-01-01

Immobility time in the forced swimming has been described as analogous to emotional blunting or apathy and has been used for characterizing schizophrenia animal models. Several clinical studies support the use of NMDA receptor antagonists to model schizophrenia in rodents. Some works describe the effects of ketamine on immobility behavior but there is variability in the experimental design used leading to controversial results. In this study, we evaluated the effects of repeated administration of ketamine sub-anesthetic doses in forced swimming, locomotion in response to novelty and novel object recognition, aiming a broader evaluation of the usefulness of this experimental approach for modeling schizophrenia in mice. Ketamine (30 mg/kg/day i.p. for 14 days) induced a not persistent decrease in immobility time, detected 24h but not 72h after treatment. This same administration protocol induced a deficit in novel object recognition. No change was observed in mice locomotion. Our results confirm that repeated administration of sub-anesthetic doses of ketamine is useful in modeling schizophrenia-related behavioral changes in mice. However, the immobility time during forced swimming does not seem to be a good endpoint to evaluate the modeling of negative symptoms in NMDAR antagonist animal models of schizophrenia.

Highly sensitive MicroRNA 146a detection using a gold nanoparticle-based CTG repeat probing system and isothermal amplification.

PubMed

Le, Binh Huy; Seo, Young Jun

2018-01-25

We have developed a gold nanoparticle (AuNP)-based CTG repeat probing system displaying high quenching capability and combined it with isothermal amplification for the detection of miRNA 146a. This method of using a AuNP-based CTG repeat probing system with isothermal amplification allowed the highly sensitive (14 aM) and selective detection of miRNA 146a. A AuNP-based CTG repeat probing system having a hairpin structure and a dT F fluorophore exhibited highly efficient quenching because the CTG repeat-based stable hairpin structure imposed a close distance between the AuNP and the dT F residue. A small amount of miRNA 146a induced multiple copies of the CAG repeat sequence during rolling circle amplification; the AuNP-based CTG repeat probing system then bound to the complementary multiple-copy CAG repeat sequence, thereby inducing a structural change from a hairpin to a linear structure with amplified fluorescence. This AuNP-based CTG probing system combined with isothermal amplification could also discriminate target miRNA 146a from one- and two-base-mismatched miRNAs (ORN 1 and ORN 2, respectively). This simple AuNP-based CTG probing system, combined with isothermal amplification to induce a highly sensitive change in fluorescence, allows the detection of miRNA 146a with high sensitivity (14 aM) and selectivity. Copyright © 2017 Elsevier B.V. All rights reserved.

DNA CTG triplet repeats involved in dynamic mutations of neurologically related gene sequences form stable duplexes

NASA Technical Reports Server (NTRS)

Smith, G. K.; Jie, J.; Fox, G. E.; Gao, X.

1995-01-01

DNA triplet repeats, 5'-d(CTG)n and 5'-d(CAG)n, are present in genes which have been implicated in several neurodegenerative disorders. To investigate possible stable structures formed by these repeating sequences, we have examined d(CTG)n, d(CAG)n and d(CTG).d(CAG)n (n = 2 and 3) using NMR and UV optical spectroscopy. These studies reveal that single stranded (CTG)n (n > 2) forms stable, antiparallel helical duplexes, while the single stranded (CAG)n requires at least three repeating units to form a duplex. NMR and UV melting experiments show that the Tm increases in the order of [(CAG)3]2 < [(CTG)3]2 << (CAG)3.(CTG)3. The (CTG)3 duplex is stable and exhibits similar NMR spectra in solutions containing 0.1-4 M NaCl and at a pH range from 4.6 to 8.8. The (CTG)3 duplex, which contains multiple-T.T mismatches, displays many NMR spectral characteristics similar to those of B-form DNA. However, unique NOE and 1H-31P coupling patterns associated with the repetitive T.T mismatches in the CTG repeats are discerned. These results, in conjunction with recent in vitro studies suggest that longer CTG repeats may form hairpin structures, which can potentially cause interruption in replication, leading to dynamic expansion or deletion of triplet repeats.

Affect-regulated exercise intensity: does training at an intensity that feels 'good' improve physical health?

PubMed

Parfitt, Gaynor; Alrumh, Amnah; Rowlands, Alex V

2012-11-01

Affect-regulated exercise to feel 'good' can be used to control exercise intensity amongst both active and sedentary individuals and should support exercise adherence. It is not known, however, whether affect-regulated exercise training can lead to physical health gains. The aim of this study was to examine if affect-regulated exercise to feel 'good' leads to improved fitness over the course of an 8-week training programme. A repeated measures design (pretest-posttest) with independent groups (training and control). 20 sedentary females completed a submaximal graded exercise test and were then allocated to either a training group or control group. The training group completed two supervised sessions and one unsupervised session per week for 8 weeks. Exercise intensity was affect-regulated to feel 'good'. Following the 8 weeks of training, both groups completed a second submaximal graded exercise test. Repeated measures analyses of variance indicated a significant increase in the time to reach ventilatory threshold in the training group (318 ± 23.7s) compared to control (248 ± 16.9s). Overall compliance to training was high (>92%). Participants in the training group exercised at intensities that would be classified as being in the lower range of the recommended guidelines (≈ 50% V˙O(2) max) for cardiovascular health. Affect-regulated exercise to feel 'good' can be used in a training programme to regulate exercise intensity. This approach led to a 19% increase in time to reach ventilatory threshold, which is indicative of improved fitness. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Evaluation of the Implementation of Good Handling Practices in Food and Beverage Areas of Hotels.

PubMed

Serafim, A L; Hecktheuer, L H R; Stangarlin-Fiori, L; Medeiros, L B; Martello, L; Machado, C E

2015-11-01

Because of the major international-level events that have recently been held in Brazil, concerns about the sensory and hygienic-sanitary conditions of food have increased. The objective of this study was to evaluate the implementation of good handling practices in food and beverage areas of hotels, with and without outsourced professional intervention. We evaluated 19 food and beverage areas in hotels in Porto Alegre, Rio do Sul, Brazil, using a checklist that was developed by a municipal surveillance team based on existing laws for good handling practices. The evaluation was done by a skilled professional in the food safety area on two occasions, at the beginning of the study (January to May 2013) and at the end (July to November 2014), and the establishments were classified as good, regular, or poor. After the baseline evaluation, an action plan listing the noncompliance found at each location was given to those responsible for the establishments, and a period of 1 year 6 months was stipulated for improvements to be made. In the repeat evaluation, those responsible for the establishments were asked whether they had hired an outsourced professional to assist them in the improvements. The hotels showed improvement during the repeat evaluation, but a significant increase in the percentage of overall adequacy was seen only in the food and beverages areas of the 12 hotels that used the intervention of an outsourced professional. The better percentage of adequacy in establishments with outsourced professional intervention underlines the importance of an external and impartial view of routine activities in the implementation of good handling practices.

Repeated and random components in Oklahoma's monthly precipitation record

USDA-ARS?s Scientific Manuscript database

Precipitation across Oklahoma exhibits a high degree of spatial and temporal variability and creates numerous water resources management challenges. The monthly precipitation record of the Central Oklahoma climate division was evaluated in a proof-of-concept to establish whether a simple monthly pre...

Finding FMR1 mosaicism in Fragile X syndrome

PubMed Central

Gonçalves, Thaís Fernandez; dos Santos, Jussara Mendonça; Gonçalves, Andressa Pereira; Tassone, Flora; Mendoza-Morales, Guadalupe; Ribeiro, Márcia Gonçalves; Kahn, Evelyn; Boy, Raquel; Pimentel, Márcia Mattos Gonçalves; Santos-Rebouças, Cíntia Barros

2016-01-01

OBJETIVE Almost all patients with Fragile X Syndrome (FXS) exhibit a CGG repeat expansion (full mutation) in the Fragile Mental Retardation 1 gene (FMR1). Here, we report five unrelated males with FXS harboring a somatic full mutation/deletion mosaicism. METHODS Mutational profiles were only elucidated by using a combination of molecular approaches (CGG-based PCR, Sanger sequencing, MS-MLPA, Southern blot and mPCR). RESULT Four patients exhibited small deletions encompassing the CGG repeats tract and flanking regions, whereas the remaining had a larger deletion comprising at least exon 1 and part of intron 1 of FMR1 gene. The presence of a 2–3 base pairs microhomology in proximal and distal non-recurrent breakpoints without scars supports the involvement of microhomology mediated induced repair (MMBIR) mechanism in three small deletions. CONCLUSION Our data highlights the importance of using different research methods to elucidate atypical FXS mutational profiles, which are clinically undistinguishable and may have been underestimated. PMID:26716517

Assessment of statistical uncertainty in the quantitative analysis of solid samples in motion using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Cabalín, L. M.; González, A.; Ruiz, J.; Laserna, J. J.

2010-08-01

Statistical uncertainty in the quantitative analysis of solid samples in motion by laser-induced breakdown spectroscopy (LIBS) has been assessed. For this purpose, a LIBS demonstrator was designed and constructed in our laboratory. The LIBS system consisted of a laboratory-scale conveyor belt, a compact optical module and a Nd:YAG laser operating at 532 nm. The speed of the conveyor belt was variable and could be adjusted up to a maximum speed of 2 m s - 1 . Statistical uncertainty in the analytical measurements was estimated in terms of precision (reproducibility and repeatability) and accuracy. The results obtained by LIBS on shredded scrap samples under real conditions have demonstrated that the analytical precision and accuracy of LIBS is dependent on the sample geometry, position on the conveyor belt and surface cleanliness. Flat, relatively clean scrap samples exhibited acceptable reproducibility and repeatability; by contrast, samples with an irregular shape or a dirty surface exhibited a poor relative standard deviation.

First GPS baseline results from the North Andes

NASA Technical Reports Server (NTRS)

Kellogg, James N.; Freymueller, Jeffrey T.; Dixon, Timothy H.; Neilan, Ruth E.; Ropain, Clemente

1990-01-01

The CASA Uno GPS experiment (January-February 1988) has provided the first epoch baseline measurements for the study of plate motions and crustal deformation in and around the North Andes. Two dimensional horizontal baseline repeatabilities are as good as 5 parts in 10 to the 8th for short baselines (100-1000 km), and better than 3 parts in 10 to the 8th for long baselines (greater than 1000 km). Vertical repeatabilities are typically 4-6 cm, with a weak dependence on baseline length. The expected rate of plate convergence across the Colombia Trench is 6-8cm/yr, which should be detectable by the repeat experiment planned for 1991. Expected deformation rates within the North Andes are of the order of 1 cm/yr, which may be detectable with the 1991 experiment.

Large membrane deflection via capillary force actuation

NASA Astrophysics Data System (ADS)

Barth, Christina A.; Hu, Xiaoyu; Mibus, Marcel A.; Reed, Michael L.; Knospe, Carl R.

2018-06-01

Experimental results from six prototype devices demonstrate that pressure changes induced in a liquid bridge via electrowetting can generate large deflections (20–75 µm) of an elastomeric membrane similar to those used in lab-on-a-chip microfluidic devices. In all cases deflections are obtained with a low voltage (20 V) and very small power consumption (<1 µW). The effects of variations in the bridge size and membrane dimensions on measured displacements are examined. Theoretical predictions are in good agreement with the measured displacements in those cases where the liquid contact angles could be measured within the devices during electrowetting. Contact angle hysteresis and charge injection into the dielectric layers limited the repeatability of deflection behavior during repeated cycling. Approaches for achieving greater deflections and improved repeatability are discussed.

Identification and characterization of tandem repeats in exon III of dopamine receptor D4 (DRD4) genes from different mammalian species.

PubMed

Larsen, Svend Arild; Mogensen, Line; Dietz, Rune; Baagøe, Hans Jørgen; Andersen, Mogens; Werge, Thomas; Rasmussen, Henrik Berg

2005-12-01

In this study we have identified and characterized dopamine receptor D4 (DRD4) exon III tandem repeats in 33 public available nucleotide sequences from different mammalian species. We found that the tandem repeat in canids could be described in a novel and simple way, namely, as a structure composed of 15- and 12- bp modules. Tandem repeats composed of 18-bp modules were found in sequences from the horse, zebra, onager, and donkey, Asiatic bear, polar bear, common raccoon, dolphin, harbor porpoise, and domestic cat. Several of these sequences have been analyzed previously without a tandem repeat being found. In the domestic cow and gray seal we identified tandem repeats composed of 36-bp modules, each consisting of two closely related 18-bp basic units. A tandem repeat consisting of 9-bp modules was identified in sequences from mink and ferret. In the European otter we detected an 18-bp tandem repeat, while a tandem repeat consisting of 27-bp modules was identified in a sequence from European badger. Both these tandem repeats were composed of 9-bp basic units, which were closely related with the 9-bp repeat modules identified in the mink and ferret. Tandem repeats could not be identified in sequences from rodents. All tandem repeats possessed a high GC content with a strong bias for C. On phylogenetic analysis of the tandem repeats evolutionary related species were clustered into the same groups. The degree of conservation of the tandem repeats varied significantly between species. The deduced amino acid sequences of most of the tandem repeats exhibited a high propensity for disorder. This was also the case with an amino acid sequence of the human DRD4 exon III tandem repeat, which was included in the study for comparative purposes. We identified proline-containing motifs for SH3 and WW domain binding proteins, potential phosphorylation sites, PDZ domain binding motifs, and FHA domain binding motifs in the amino acid sequences of the tandem repeats. The numbers of potential functional sites varied pronouncedly between species. Our observations provide a platform for future studies of the architecture and evolution of the DRD4 exon III tandem repeat, and they suggest that differences in the structure of this tandem repeat contribute to specialization and generation of diversity in receptor function.

A new approach to the measurement of pelvic asymmetry: proposed methods and reliability.

PubMed

Gnat, Rafael; Biały, Maciej

2015-05-01

This is a methodological study presenting a novel method of pelvic asymmetry (PA) measurement for use in the research laboratory setting. The purpose of the study is (1) to establish intrarater and interrater reliability of the proposed measures of PA, (2) to verify the influence of repeated measurements on the reliability, and (3) to assess correlation between the proposed measures of PA. Twelve healthy volunteers participated, and 2 teams of raters were involved. Registration of anatomic landmarks' positions in the optical motion capture system was repeated 3 times. Two asymmetry indexes were calculated: for pelvic torsion and for lateral pelvic tilt. Interclass correlation coefficients (ICCs), standard errors of measurement, and smallest detectable differences were used to describe the intrarater and interrater reliability of the 2 indexes. After 2 repeated registrations of pelvic landmarks' positions, the reliability of our asymmetry indexes was good and excellent. The ICCs for intrarater reliability ranged from 0.96 to 0.97; the ICCs for interrater reliability ranged 0.81 to 0.90. There was moderate, nonsignificant correlation between asymmetry indexes for pelvis torsion and for lateral pelvic tilt (r = 0.45, P = .14). The 2 proposed asymmetry indexes showed good and excellent intrarater and interrater reliability after 2 repeated registrations of pelvic landmarks' positions and thus may be useful in the research laboratory setting. However, these indexes are not strongly correlated, which suggests that the 2 types of PA may constitute different clinical entities. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

Based Upon Repeat Pattern (BURP): an algorithm to characterize the long-term evolution of Staphylococcus aureus populations based on spa polymorphisms.

PubMed

Mellmann, Alexander; Weniger, Thomas; Berssenbrügge, Christoph; Rothgänger, Jörg; Sammeth, Michael; Stoye, Jens; Harmsen, Dag

2007-10-29

For typing of Staphylococcus aureus, DNA sequencing of the repeat region of the protein A (spa) gene is a well established discriminatory method for outbreak investigations. Recently, it was hypothesized that this region also reflects long-term epidemiology. However, no automated and objective algorithm existed to cluster different repeat regions. In this study, the Based Upon Repeat Pattern (BURP) implementation that is a heuristic variant of the newly described EDSI algorithm was investigated to infer the clonal relatedness of different spa types. For calibration of BURP parameters, 400 representative S. aureus strains with different spa types were characterized by MLST and clustered using eBURST as "gold standard" for their phylogeny. Typing concordance analysis between eBURST and BURP clustering (spa-CC) were performed using all possible BURP parameters to determine their optimal combination. BURP was subsequently evaluated with a strain collection reflecting the breadth of diversity of S. aureus (JCM 2002; 40:4544). In total, the 400 strains exhibited 122 different MLST types. eBURST grouped them into 23 clonal complexes (CC; 354 isolates) and 33 singletons (46 isolates). BURP clustering of spa types using all possible parameter combinations and subsequent comparison with eBURST CCs resulted in concordances ranging from 8.2 to 96.2%. However, 96.2% concordance was reached only if spa types shorter than 8 repeats were excluded, which resulted in 37% excluded spa types. Therefore, the optimal combination of the BURP parameters was "exclude spa types shorter than 5 repeats" and "cluster spa types into spa-CC if cost distances are less than 4" exhibiting 95.3% concordance to eBURST. This algorithm identified 24 spa-CCs, 40 singletons, and excluded only 7.8% spa types. Analyzing the natural population with these parameters, the comparison of whole-genome micro-array groupings (at the level of 0.31 Pearson correlation index) and spa-CCs gave a concordance of 87.1%; BURP spa-CCs vs. manually grouped spa types resulted in 95.7% concordance. BURP is the first automated and objective tool to infer clonal relatedness from spa repeat regions. It is able to extract an evolutionary signal rather congruent to MLST and micro-array data.

Comparative analyses of two thermophilic enzymes exhibiting both beta-1,4 mannosidic and beta-1,4 glucosidic cleavage activities from Caldanaerobius polysaccharolyticus.

PubMed

Han, Yejun; Dodd, Dylan; Hespen, Charles W; Ohene-Adjei, Samuel; Schroeder, Charles M; Mackie, Roderick I; Cann, Isaac K O

2010-08-01

The hydrolysis of polysaccharides containing mannan requires endo-1,4-beta-mannanase and 1,4-beta-mannosidase activities. In the current report, the biochemical properties of two endo-beta-1,4-mannanases (Man5A and Man5B) from Caldanaerobius polysaccharolyticus were studied. Man5A is composed of an N-terminal signal peptide (SP), a catalytic domain, two carbohydrate-binding modules (CBMs), and three surface layer homology (SLH) repeats, whereas Man5B lacks the SP, CBMs, and SLH repeats. To gain insights into how the two glycoside hydrolase family 5 (GH5) enzymes may aid the bacterium in energy acquisition and also the potential application of the two enzymes in the biofuel industry, two derivatives of Man5A (Man5A-TM1 [TM1 stands for truncational mutant 1], which lacks the SP and SLH repeats, and Man5A-TM2, which lacks the SP, CBMs, and SLH repeats) and the wild-type Man5B were biochemically analyzed. The Man5A derivatives displayed endo-1,4-beta-mannanase and endo-1,4-beta-glucanase activities and hydrolyzed oligosaccharides with a degree of polymerization (DP) of 4 or higher. Man5B exhibited endo-1,4-beta-mannanase activity and little endo-1,4-beta-glucanase activity; however, this enzyme also exhibited 1,4-beta-mannosidase and cellodextrinase activities. Man5A-TM1, compared to either Man5A-TM2 or Man5B, had higher catalytic activity with soluble and insoluble polysaccharides, indicating that the CBMs enhance catalysis of Man5A. Furthermore, Man5A-TM1 acted synergistically with Man5B in the hydrolysis of beta-mannan and carboxymethyl cellulose. The versatility of the two enzymes, therefore, makes them a resource for depolymerization of mannan-containing polysaccharides in the biofuel industry. Furthermore, on the basis of the biochemical and genomic data, a molecular mechanism for utilization of mannan-containing nutrients by C. polysaccharolyticus is proposed.

Ionic strength and temperature induced conformational changes in mononucleosomes and oligonucleosomes. [Chromatin

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

Schmitz, K.S.; Kent, J.C.; Parthasarathy, N.

1980-10-01

Chromatin is a nucleohistone complex which exhibits a repeat unit structure as inferred from nuclease digestion studies. The repeat unit, or nucleosome, is defined as approx. 200 base pairs of DNA wrapped about the surface of an octameric histone complex (two copies each of the histones H2A, H2B, H3, and H4). We report in this communication preliminary studies on the conformation of chromatin mononucleosomes and oligonucleosomes as a function of temperature and ionic strength. The methods used were conductivity, fluorescence of bound proflavine, and quasielastic light scattering.

Monitoring Seawall Deformation With Repeat-Track Space-Borne SAR Images

NASA Astrophysics Data System (ADS)

Pei, Yuanyuan; Wan, Qing; Wei, Lianhuan; Fang, Zhilei; Liao, Mingsheng

2010-10-01

Seawalls are constructed to protect coastal cities from typhoon, flood and sea tide. It is necessary to monitor the deformation of seawalls in real time. Repeat-track space-borne SAR images are useful for environment monitoring, especially ground deformation monitoring. Shanghai sits on the Yangtze River Delta on China's eastern coast. Each year, the city is hit by typhoons from Pacific Ocean and threatened by the flood of the Yangtze River. PS-InSAR technique is carried out to monitor the deformation of the seawalls. Experiment exhibits that the seawalls around Pudong airport and Lingang town suffered serious deformation.

Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide

DOEpatents

Poston, J.A.

1997-12-02

Mixed metal oxide pellets for removing hydrogen sulfide from fuel gas mixes derived from coal are stabilized for operation over repeated cycles of desulfurization and regeneration reactions by addition of a large promoter metal oxide such as lanthanum trioxide. The pellets, which may be principally made up of a mixed metal oxide such as zinc titanate, exhibit physical stability and lack of spalling or decrepitation over repeated cycles without loss of reactivity. The lanthanum oxide is mixed with pellet-forming components in an amount of 1 to 10 weight percent.

Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide

DOEpatents

Poston, James A.

1997-01-01

Mixed metal oxide pellets for removing hydrogen sulfide from fuel gas mixes derived from coal are stabilized for operation over repeated cycles of desulfurization and regeneration reactions by addition of a large promoter metal oxide such as lanthanum trioxide. The pellets, which may be principally made up of a mixed metal oxide such as zinc titanate, exhibit physical stability and lack of spalling or decrepitation over repeated cycles without loss of reactivity. The lanthanum oxide is mixed with pellet-forming components in an amount of 1 to 10 weight percent.

Evidence of Circadian Rhythm, Oxygen Regulation Capacity, Metabolic Repeatability and Positive Correlations between Forced and Spontaneous Maximal Metabolic Rates in Lake Sturgeon Acipenser fulvescens

PubMed Central

Svendsen, Jon C.; Genz, Janet; Anderson, W. Gary; Stol, Jennifer A.; Watkinson, Douglas A.; Enders, Eva C.

2014-01-01

Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons). Using juvenile lake sturgeon (Acipenser fulvescens), the objective of this study was to test four hypotheses: 1) A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2) A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3) measurements of forced maximum metabolic rate (MMRF) are repeatable in individual fish; and 4) MMRF correlates positively with spontaneous maximum metabolic rate (MMRS). Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMRF. Trials lasting 24 h were used to measure standard metabolic rate (SMR) and MMRS. Repeatability and correlations between MMRF and MMRS were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O2sat)), demonstrating oxygen regulation. In contrast, MMRF was affected by hypoxia and decreased across the range from 100% O2sat to 70% O2sat. MMRF was repeatable in individual fish, and MMRF correlated positively with MMRS, but the relationships between MMRF and MMRS were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor). Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMRF and MMRS support the conjecture that MMRF represents a measure of organism performance that could be a target of natural selection. PMID:24718688

Biobutanol production in a Clostridium acetobutylicum biofilm reactor integrated with simultaneous product recovery by adsorption

PubMed Central

2014-01-01

Background Clostridium acetobutylicum can propagate on fibrous matrices and form biofilms that have improved butanol tolerance and a high fermentation rate and can be repeatedly used. Previously, a novel macroporous resin, KA-I, was synthesized in our laboratory and was demonstrated to be a good adsorbent with high selectivity and capacity for butanol recovery from a model solution. Based on these results, we aimed to develop a process integrating a biofilm reactor with simultaneous product recovery using the KA-I resin to maximize the production efficiency of biobutanol. Results KA-I showed great affinity for butanol and butyrate and could selectively enhance acetoin production at the expense of acetone during the fermentation. The biofilm reactor exhibited high productivity with considerably low broth turbidity during repeated batch fermentations. By maintaining the butanol level above 6.5 g/L in the biofilm reactor, butyrate adsorption by the KA-I resin was effectively reduced. Co-adsorption of acetone by the resin improved the fermentation performance. By redox modulation with methyl viologen (MV), the butanol-acetone ratio and the total product yield increased. An equivalent solvent titer of 96.5 to 130.7 g/L was achieved with a productivity of 1.0 to 1.5 g · L-1 · h-1. The solvent concentration and productivity increased by 4 to 6-fold and 3 to 5-fold, respectively, compared to traditional batch fermentation using planktonic culture. Conclusions Compared to the conventional process, the integrated process dramatically improved the productivity and reduced the energy consumption as well as water usage in biobutanol production. While genetic engineering focuses on strain improvement to enhance butanol production, process development can fully exploit the productivity of a strain and maximize the production efficiency. PMID:24401161

Development of an optically-based tension-indicating implanted orthopedic screw with a luminescent spectral ruler

NASA Astrophysics Data System (ADS)

Ravikumar, Nakul; Rogalski, Melissa M.; Benza, Donny; Lake, Joshua; Urban, Matthew; Pelham, Hunter; Anker, Jeffrey N.; DesJardins, John D.

2017-03-01

An orthopaedic screw was designed with an optical tension-indicator to non-invasively quantify screw tension and monitor the load sharing between the bone and the implant. The screw both applies load to the bone, and measures this load by reporting the strain on the screw. The screw contains a colorimetric optical encoder that converts axial strain into colorimetric changes visible through the head of the screw, or luminescent spectral changes that are detected through tissue. Screws were tested under cyclic mechanical loading to mimic in-vivo conditions to verify the sensitivity, repeatability, and reproducibility of the sensor. In the absence to tissue, color was measured using a digital camera as a function of axial load on a stainless steel cannulated (hollow) orthopedic screw, modified by adding a passive colorimetric strain gauge through the central hole. The sensor was able to quantify clinically-relevant bone healing strains. The sensor exhibited good repeatability and reproducibility but also displayed hysteresis due to the internal mechanics of the screw. The strain indicator was also modified for measurement through tissue by replacing the reflective colorimetric sensor with a low-background X-ray excited optical luminescence signal. Luminescent spectra were acquired through 6 mm of chicken breast tissue. Overall, this research shows feasibility for a unique device which quantifies the strain on an orthopedic screw. Future research will involve reducing hysteresis by changing the mechanism of strain transduction in the screw, miniaturizing the luminescent strain gauge, monitoring bending as well as tension, using alternative luminescent spectral rulers based upon near infrared fluorescence or upconversion luminescence, and application to monitoring changes in pretension and load sharing during bone healing.

Validation of a High Sampling Rate Inertial Measurement Unit for Acceleration During Running.

PubMed

Provot, Thomas; Chiementin, Xavier; Oudin, Emeric; Bolaers, Fabrice; Murer, Sébastien

2017-08-25

The musculo-skeletal response of athletes to various activities during training exercises has become a critical issue in order to optimize their performance and minimize injuries. However, dynamic and kinematic measures of an athlete's activity are generally limited by constraints in data collection and technology. Thus, the choice of reliable and accurate sensors is crucial for gathering data in indoor and outdoor conditions. The aim of this study is to validate the use of the accelerometer of a high sampling rate ( 1344 Hz ) Inertial Measurement Unit (IMU) in the frame of running activities. To this end, two validation protocols are imposed: a classical one on a shaker, followed by another one during running, the IMU being attached to a test subject. For each protocol, the response of the IMU Accelerometer (IMUA) is compared to a calibrated industrial accelerometer, considered as the gold standard for dynamic and kinematic data collection. The repeatability, impact of signal frequency and amplitude (on shaker) as well as the influence of speed (while running) are investigated. Results reveal that the IMUA exhibits good repeatability. Coefficient of Variation CV is 1 % 8.58 ± 0.06 m / s 2 on the shaker and 3 % 26.65 ± 0.69 m / s 2 while running. However, the shaker test shows that the IMUA is affected by the signal frequency (error exceeds 10 % beyond 80 Hz ), an observation confirmed by the running test. Nevertheless, the IMUA provides a reliable measure in the range 0-100 Hz, i.e., the most relevant part in the energy spectrum over the range 0-150 Hz during running. In our view, these findings emphasize the validity of IMUs for the measurement of acceleration during running.

Orthogonal Comparison of GC-MS and 1H NMR Spectroscopy for Short Chain Fatty Acid Quantitation.

PubMed

Cai, Jingwei; Zhang, Jingtao; Tian, Yuan; Zhang, Limin; Hatzakis, Emmanuel; Krausz, Kristopher W; Smith, Philip B; Gonzalez, Frank J; Patterson, Andrew D

2017-08-01

Short chain fatty acids (SCFAs) are important regulators of host physiology and metabolism and may contribute to obesity and associated metabolic diseases. Interest in SCFAs has increased in part due to the recognized importance of how production of SCFAs by the microbiota may signal to the host. Therefore, reliable, reproducible, and affordable methods for SCFA profiling are required for accurate identification and quantitation. In the current study, four different methods for SCFA (acetic acid, propionic acid, and butyric acid) extraction and quantitation were compared using two independent platforms including gas chromatography coupled with mass spectrometry (GC-MS) and 1 H nuclear magnetic resonance (NMR) spectroscopy. Sensitivity, recovery, repeatability, matrix effect, and validation using mouse fecal samples were determined across all methods. The GC-MS propyl esterification method exhibited superior sensitivity for acetic acid and butyric acid measurement (LOD < 0.01 μg mL -1 , LOQ < 0.1 μg mL -1 ) and recovery accuracy (99.4%-108.3% recovery rate for 100 μg mL -1 SCFA mixed standard spike in and 97.8%-101.8% recovery rate for 250 μg mL -1 SCFAs mixed standard spike in). NMR methods by either quantitation relative to an internal standard or quantitation using a calibration curve yielded better repeatability and minimal matrix effects compared to GC-MS methods. All methods generated good calibration curve linearity (R 2 > 0.99) and comparable measurement of fecal SCFA concentration. Lastly, these methods were used to quantitate fecal SCFAs obtained from conventionally raised (CONV-R) and germ free (GF) mice. Results from global metabolomic analysis of feces generated by 1 H NMR and bomb calorimetry were used to further validate these approaches.

Prism under cover test in alternate fixation horizontal strabismus.

PubMed

Tejedor, Jaime; Gutiérrez-Carmona, Francisco José

2018-02-01

To evaluate the applicability of the prism under cover test (PUCT) to quantify manifest deviation in horizontal strabismus with alternate fixation when simultaneous prism and cover test (SPCT) is not feasible. Children aged 4-11 years, with alternate fixation horizontal strabismus and alternate prism and cover test (APCT) distance deviation (DD) up to 25 PD were eligible. In group 1 of the study, SPCT was not feasible (n = 18), whereas in group 2, it was feasible (n = 24). Refraction, PUCT, APCT, central/peripheral fusion, and stereoacuity were measured. Repeatability of PUCT, agreement between PUCT and SPCT, and Pearson correlations between variables were studied. In group 1, mean DD was 15.6 and 9.5 PD using APCT and PUCT, respectively (intraclass correlation, ICC: 0.90). Mean stereoacuity was 201.1 arc seconds. PUCT was better correlated with stereoacuity than APCT, but not significantly (p = 0.12). Coefficient of repeatability for PUCT was 3.4 PD. In group 2, mean DD was 17.6, 14.1, and 12.5 PD using APCT, PUCT, and SPCT, respectively. Mean stereoacuity was 285.9 arc seconds. Correlations APCT-PUCT (0.87), APCT-SPCT (0.82), and SPCT-PUCT (0.95) were significant. APCT did not show as good correlation with stereoacuity (0.58) as SPCT and PUCT (0.74 and 0.78, respectively). Concordance correlation coefficient between SPCT and PUCT was 0.91, and Bland Altman agreement between the two variables was also good. PUCT is a procedure with good repeatability, of interest in children to estimate manifest deviation when SPCT is not feasible, and in support of the diagnosis of monofixation syndrome.

Reliability of corneal dynamic scheimpflug analyser measurements in virgin and post-PRK eyes.

PubMed

Chen, Xiangjun; Stojanovic, Aleksandar; Hua, Yanjun; Eidet, Jon Roger; Hu, Di; Wang, Jingting; Utheim, Tor Paaske

2014-01-01

To determine the measurement reliability of CorVis ST, a dynamic Scheimpflug analyser, in virgin and post-photorefractive keratectomy (PRK) eyes and compare the results between these two groups. Forty virgin eyes and 42 post-PRK eyes underwent CorVis ST measurements performed by two technicians. Repeatability was evaluated by comparing three consecutive measurements by technician A. Reproducibility was determined by comparing the first measurement by technician A with one performed by technician B. Intraobserver and interobserver intraclass correlation coefficients (ICCs) were calculated. Univariate analysis of covariance (ANCOVA) was used to compare measured parameters between virgin and post-PRK eyes. The intraocular pressure (IOP), central corneal thickness (CCT) and 1st applanation time demonstrated good intraobserver repeatability and interobserver reproducibility (ICC ≧ 0.90) in virgin and post-PRK eyes. The deformation amplitude showed a good or close to good repeatability and reproducibility in both groups (ICC ≧ 0.88). The CCT correlated positively with 1st applanation time (r = 0.437 and 0.483, respectively, p<0.05) and negatively with deformation amplitude (r = -0.384 and -0.375, respectively, p<0.05) in both groups. Compared to post-PRK eyes, virgin eyes showed longer 1st applanation time (7.29 ± 0.21 vs. 6.96 ± 0.17 ms, p<0.05) and lower deformation amplitude (1.06 ± 0.07 vs. 1.17 ± 0.08 mm, p < 0.05). CorVis ST demonstrated reliable measurements for CCT, IOP, and 1st applanation time, as well as relatively reliable measurement for deformation amplitude in both virgin and post-PRK eyes. There were differences in 1st applanation time and deformation amplitude between virgin and post-PRK eyes, which may reflect corneal biomechanical changes occurring after the surgery in the latter.

Physiological adaptation to recurrent social stress of extraversion.

PubMed

Lu, Wei; Wang, Zhenhong

2017-02-01

The present studies examined the influence of extraversion on physiological reactivity, recovery, and physiological habituation-sensitization to repeated social stressors. In Study 1, subjective and physiological data were collected from 97 college students who were categorized as high (n = 51) and low (n = 46) on extraversion (NEO-FFI) across five laboratory stages: baseline, stress 1, poststress 1, stress 2, and poststress 2. Results indicated high extraversion (HE) participants exhibited relative lesser heart rate (HR) reactivity and respiratory sinus arrhythmia (RSA) withdrawals to, and more complete HR and RSA recovery after the first social stress, and also exhibited relative lesser HR reactivity to the second social stress. When repeatedly exposed to a social stressor, HE participants showed pronounced systolic blood pressure (SBP) adaptation, low extraversion (LE) participants displayed diastolic blood pressure (DBP) sensitization. In Study 2, data were collected from another 78 participants (HE: n = 40, LE: n = 38) across the same laboratory stages with speech performance videotaped. After controlling for the speech styles, Study 2 found the same HR response and SBP/DBP adaptation pattern across extraversion groups to social stress as Study 1 but not RSA reactivity. These findings suggest extraverts exhibit more adaptive physiological reactivity to recurrent social stressors, which thus might benefit their health. © 2016 Society for Psychophysiological Research.

Random Number Generation in Autism.

ERIC Educational Resources Information Center

Williams, Mark A.; Moss, Simon A.; Bradshaw, John L.; Rinehart, Nicole J.

2002-01-01

This study explored the ability of 14 individuals with autism to generate a unique series of digits. Individuals with autism were more likely to repeat previous digits than comparison individuals, suggesting they may exhibit a shortfall in response inhibition. Results support the executive dysfunction theory of autism. (Contains references.)…

In vitro culture of the flagellate protozoan Hexamita salmonis

USGS Publications Warehouse

Uzmann, J.R.; Hayduk, S.H.

1963-01-01

Trophozoites of Hexamita salmonis, asserted pathogen of juvenile salmonid fishes, were isolated from two species of Pacific salmon hosts and cultured repeatedly in an organic medium saturated with nitrogen. Primary isolates and serial subcultures usually exhibited five- to tenfold population increases per passage.

Observations of Soft Gamma Repeaters

NASA Technical Reports Server (NTRS)

Kouveliotou, Chryssa

2004-01-01

Magnetars (Soft Gamma Repeaters and Anomalous X-ray Pulsars) are a subclass of neutron stars characterized by their recurrent X-ray bursts. While in an active (bursting) state (lasting anywhere between days and years), they are emit&ng hundreds of predominantly soft (kT=30 kev), short (0.1-100 ms long) events. Their quiescent source x-ray light ewes exhibit puhlions rotational period rate changes (spin-down) indicate that their magnetic fields are extremely high, of the order of 10^14- 10^l5 G. Such high B-field objects, dubbed "magnetars", had been predicted to exist in 1992, but the first concrete observational evidence were obtained in 1998 for two of these sources. I will discuss here the history of Soft Gamma Repeaters, and their spectral, timing and flux characteristics both in the persistent and their burst emission.

Retrieval and sleep both counteract the forgetting of spatial information.

PubMed

Antony, James W; Paller, Ken A

2018-06-01

Repeatedly studying information is a good way to strengthen memory storage. Nevertheless, testing recall often produces superior long-term retention. Demonstrations of this testing effect, typically with verbal stimuli, have shown that repeated retrieval through testing reduces forgetting. Sleep also benefits memory storage, perhaps through repeated retrieval as well. That is, memories may generally be subject to forgetting that can be counteracted when memories become reactivated, and there are several types of reactivation: (i) via intentional restudying, (ii) via testing, (iii) without provocation during wake, or (iv) during sleep. We thus measured forgetting for spatial material subjected to repeated study or repeated testing followed by retention intervals with sleep versus wake. Four groups of subjects learned a set of visual object-location associations and either restudied the associations or recalled locations given the objects as cues. We found the advantage for restudied over retested information was greater in the PM than AM group. Additional groups tested at 5-min and 1-wk retention intervals confirmed previous findings of greater relative benefits for restudying in the short-term and for retesting in the long-term. Results overall support the conclusion that repeated reactivation through testing or sleeping stabilizes information against forgetting. © 2018 Antony and Paller; Published by Cold Spring Harbor Laboratory Press.

Effect of calcination temperature on the electrochemical properties of nickel-rich LiNi 0.76Mn 0.14Co 0.10O 2 cathodes for lithium-ion batteries

DOE PAGES

Zheng, Jianming; Yan, Pengfei; Estevez, Luis; ...

2018-05-01

High energy density, nickel (Ni)-rich, layered LiNi xMn yCo zO 2 (NMC, x ≥ 0.6) materials are promising cathodes for lithium-ion batteries. However, several technical challenges, such as fast capacity fading and high voltage instability, hinder their large-scale application. Herein, we identified an optimum calcining temperature range for the Ni-rich cathode LiNi 0.76Mn 0.14Co 0.10O 2 (NMC76). NMC76 calcined at 750–775 °C exhibits a high discharge capacity (~215 mAh g –1 when charged to 4.5 V) and retains ca. 79% of its initial capacity after 200 cycles. It also exhibits an excellent high-rate capability, delivering a capacity of more thanmore » 160 mAh g –1 even at a 10 C rate. The high performance of NMC76 is directly related to the optimized size of its primary particles (100–300 nm) (which onstitute the spherical secondary particles of >10 µm) and cation mixing. Higher calcination temperature (≥800 °C) leads to rapid increase of primary particle size, poor cycling stability, and inferior rate capability of NMC76 due to severe micro-strain and -crack formation upon repeated lithium-ion de/intercalations. Furthermore, NMC76 calcined at 750–775 °C is a very good candidate for the next generation of Li ion batteries.« less

Novel Arylimidamides for Treatment of Visceral Leishmaniasis▿ †

PubMed Central

Wang, Michael Zhuo; Zhu, Xiaohua; Srivastava, Anuradha; Liu, Qiang; Sweat, J. Mark; Pandharkar, Trupti; Stephens, Chad E.; Riccio, Ed; Parman, Toufan; Munde, Manoj; Mandal, Swati; Madhubala, Rentala; Tidwell, Richard R.; Wilson, W. David; Boykin, David W.; Hall, James Edwin; Kyle, Dennis E.; Werbovetz, Karl A.

2010-01-01

Arylimidamides (AIAs) represent a new class of molecules that exhibit potent antileishmanial activity (50% inhibitory concentration [IC50], <1 μM) against both Leishmania donovani axenic amastigotes and intracellular Leishmania, the causative agent for human visceral leishmaniasis (VL). A systematic lead discovery program was employed to characterize in vitro and in vivo antileishmanial activities, pharmacokinetics, mutagenicities, and toxicities of two novel AIAs, DB745 and DB766. They were exceptionally active (IC50 ≤ 0.12 μM) against intracellular L. donovani, Leishmania amazonensis, and Leishmania major and did not exhibit mutagenicity in an Ames screen. DB745 and DB766, given orally, produced a dose-dependent inhibition of liver parasitemia in two efficacy models, L. donovani-infected mice and hamsters. Most notably, DB766 (100 mg/kg of body weight/day for 5 days) reduced liver parasitemia in mice and hamsters by 71% and 89%, respectively. Marked reduction of parasitemia in the spleen (79%) and bone marrow (92%) of hamsters was also observed. Furthermore, these compounds distributed to target tissues (liver and spleen) and had a moderate oral bioavailability (up to 25%), a large volume of distribution, and an elimination half-life ranging from 1 to 2 days in mice. In a repeat-dose toxicity study of mice, there was no indication of liver or kidney toxicity for DB766 from serum chemistries, although mild hepatic cell eosinophilia, hypertrophy, and fatty changes were noted. These results demonstrated that arylimidamides are a promising class of molecules that possess good antileishmanial activity and desirable pharmacokinetics and should be considered for further preclinical development as an oral treatment for VL. PMID:20368397

Effect of calcination temperature on the electrochemical properties of nickel-rich LiNi 0.76Mn 0.14Co 0.10O 2 cathodes for lithium-ion batteries

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

Zheng, Jianming; Yan, Pengfei; Estevez, Luis

High energy density, nickel (Ni)-rich, layered LiNi xMn yCo zO 2 (NMC, x ≥ 0.6) materials are promising cathodes for lithium-ion batteries. However, several technical challenges, such as fast capacity fading and high voltage instability, hinder their large-scale application. Herein, we identified an optimum calcining temperature range for the Ni-rich cathode LiNi 0.76Mn 0.14Co 0.10O 2 (NMC76). NMC76 calcined at 750–775 °C exhibits a high discharge capacity (~215 mAh g –1 when charged to 4.5 V) and retains ca. 79% of its initial capacity after 200 cycles. It also exhibits an excellent high-rate capability, delivering a capacity of more thanmore » 160 mAh g –1 even at a 10 C rate. The high performance of NMC76 is directly related to the optimized size of its primary particles (100–300 nm) (which onstitute the spherical secondary particles of >10 µm) and cation mixing. Higher calcination temperature (≥800 °C) leads to rapid increase of primary particle size, poor cycling stability, and inferior rate capability of NMC76 due to severe micro-strain and -crack formation upon repeated lithium-ion de/intercalations. Furthermore, NMC76 calcined at 750–775 °C is a very good candidate for the next generation of Li ion batteries.« less

Long interspersed repeated DNA (LINE) causes polymorphism at the rat insulin 1 locus.

PubMed Central

Lakshmikumaran, M S; D'Ambrosio, E; Laimins, L A; Lin, D T; Furano, A V

1985-01-01

The insulin 1, but not the insulin 2, locus is polymorphic (i.e., exhibits allelic variation) in rats. Restriction enzyme analysis and hybridization studies showed that the polymorphic region is 2.2 kilobases upstream of the insulin 1 coding region and is due to the presence or absence of an approximately 2.7-kilobase repeated DNA element. DNA sequence determination showed that this DNA element is a member of a long interspersed repeated DNA family (LINE) that is highly repeated (greater than 50,000 copies) and highly transcribed in the rat. Although the presence or absence of LINE sequences at the insulin 1 locus occurs in both the homozygous and heterozygous states, LINE-containing insulin 1 alleles are more prevalent in the rat population than are alleles without LINEs. Restriction enzyme analysis of the LINE-containing alleles indicated that at least two versions of the LINE sequence may be present at the insulin 1 locus in different rats. Either repeated transposition of LINE sequences or gene conversion between the resident insulin 1 LINE and other sequences in the genome are possible explanations for this. Images PMID:3016521

Synthesis of zinc oxide nanoparticles on graphene-carbon nanotube hybrid for glucose biosensor applications.

PubMed

Hwa, Kuo-Yuan; Subramani, Boopathi

2014-12-15

Synthesis of zinc oxide nanoparticles incorporated graphene-carbon nanotubes hybrid (GR-CNT-ZnO) through a simple, one-pot method is demonstrated. The as-synthesized GR-CNT-ZnO composite is applied to fabricate an enzyme based glucose biosensor. The GOx immobilized on GR-CNT-ZnO composite exhibits well-defined redox peaks with a peak potential separation (ΔEp) of about 26 mV with enhanced peak currents, indicating a fast electron transfer at the modified electrode surface. The cyclic voltammetry measurements revealed that the modified film has high electrocatalytic ability towards glucose detection in the presence of oxygen. The proposed sensor has a wide linear detection range from 10 μM to 6.5 mM of glucose with a limit of detection (LOD) of 4.5 (±0.08) μM. In addition, the sensor possessed appreciable repeatability, reproducibility and remarkable stability for the sensitive determination of glucose. The practicality of this sensor has been demonstrated in human serum samples, with results being in good agreement with those determined using a standard photometric method. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Pruss, T.; Wolf, P.S.

Indapamide is a new indoline antihypertensive diuretic agent whose chemical structure differs substantially from those of the thiazides. The hydrophobic indoline moiety of indapamide confers a lipid solubility to the molecule that is 5 to 80 times greater than that of the thiazide diuretics. Thus indapamide accumulates in vascular smooth muscle at a concentration 10 times higher than that of protein-free perfusate. The affinity of indapamide for vascular smooth muscle manifests itself in vitro and in vivo as a decrease in reactivity following various pharmacologic interventions. Moreover, in vitro studies have demonstrated that indapamide decreases the inward calcium current andmore » the transmembrane influx of calcium. The diuretic effect of indapamide is predominantly due to inhibition of sodium reabsorption at the cortical diluting segment of the distal convoluted tubule. In animal studies, intravenous indapamide has no effect on glomerular filtration rate or renal blood flow. Indapamide is well absorbed and extensively metabolized in animals and humans, with biliary excretion being the predominant route of elimination in animals. Most important, repeat administration of indapamide to dogs with both kidneys removed produces no accumulation of intact indapamide or its metabolites. Extensive drug safety studies in animals indicate that indapamide produces no overt toxicity and exhibits a good margin of safety.« less

The Capability of Fiber Bragg Grating Sensors to Measure Amputees' Trans-Tibial Stump/Socket Interface Pressures

PubMed Central

Al-Fakih, Ebrahim A.; Abu Osman, Noor Azuan; Eshraghi, Arezoo; Adikan, Faisal Rafiq Mahamd

2013-01-01

This study presents the first investigation into the capability of fiber Bragg grating (FBG) sensors to measure interface pressure between the stump and the prosthetic sockets of a trans-tibial amputee. FBG element(s) were recoated with and embedded in a thin layer of epoxy material to form a sensing pad, which was in turn embedded in a silicone polymer material to form a pressure sensor. The sensor was tested in real time by inserting a heavy-duty balloon into the socket and inflating it by using an air compressor. This test was conducted to examine the sensitivity and repeatability of the sensor when subjected to pressure from the stump of the trans-tibial amputee and to mimic the actual environment of the amputee's Patellar Tendon (PT) bar. The sensor exhibited a sensitivity of 127 pm/N and a maximum FSO hysteresis of around ∼0.09 in real-time operation. Very good reliability was achieved when the sensor was utilized for in situ measurements. This study may lead to smart FBG-based amputee stump/socket structures for pressure monitoring in amputee socket systems, which will result in better-designed prosthetic sockets that ensure improved patient satisfaction. PMID:23941909

Population structure in Japanese rice population

PubMed Central

Yamasaki, Masanori; Ideta, Osamu

2013-01-01

It is essential to elucidate genetic diversity and relationships among even related individuals and populations for plant breeding and genetic analysis. Since Japanese rice breeding has improved agronomic traits such as yield and eating quality, modern Japanese rice cultivars originated from narrow genetic resource and closely related. To resolve the population structure and genetic diversity in Japanese rice population, we used a total of 706 alleles detected by 134 simple sequence repeat markers in a total of 114 cultivars composed of 94 improved varieties and 20 landraces, which are representative and important for Japanese rice breeding. The landraces exhibit greater gene diversity than improved lines, suggesting that landraces can provide additional genetic diversity for future breeding. Model-based Bayesian clustering analysis revealed six subgroups and admixture situation in the cultivars, showing good agreement with pedigree information. This method could be superior to phylogenetic method in classifying a related population. The leading Japanese rice cultivar, Koshihikari is unique due to the specific genome constitution. We defined Japanese rice diverse sets that capture the maximum number of alleles for given sample sizes. These sets are useful for a variety of genetic application in Japanese rice cultivars. PMID:23641181

The capability of fiber Bragg grating sensors to measure amputees' trans-tibial stump/socket interface pressures.

PubMed

Al-Fakih, Ebrahim A; Osman, Noor Azuan Abu; Eshraghi, Arezoo; Adikan, Faisal Rafiq Mahamd

2013-08-12

This study presents the first investigation into the capability of fiber Bragg grating (FBG) sensors to measure interface pressure between the stump and the prosthetic sockets of a trans-tibial amputee. FBG element(s) were recoated with and embedded in a thin layer of epoxy material to form a sensing pad, which was in turn embedded in a silicone polymer material to form a pressure sensor. The sensor was tested in real time by inserting a heavy-duty balloon into the socket and inflating it by using an air compressor. This test was conducted to examine the sensitivity and repeatability of the sensor when subjected to pressure from the stump of the trans-tibial amputee and to mimic the actual environment of the amputee's Patellar Tendon (PT) bar. The sensor exhibited a sensitivity of 127 pm/N and a maximum FSO hysteresis of around ~0.09 in real-time operation. Very good reliability was achieved when the sensor was utilized for in situ measurements. This study may lead to smart FBG-based amputee stump/socket structures for pressure monitoring in amputee socket systems, which will result in better-designed prosthetic sockets that ensure improved patient satisfaction.

Separation of plant hormones from biofertilizer by capillary electrophoresis using a capillary coated dynamically with polycationic polymers.

PubMed

Jiang, Ting-Fu; Lv, Zhi-Hua; Wang, Yuan-Hong; Yue, Mei-E

2006-06-01

A new, simple and rapid capillary electrophoresis (CE) method, using hexadimethrine bromide (HDB) as electroosmotic flow (EOF) modifier, was developed for the identification and quantitative determination of four plant hormones, including gibberellin A3 (GA3), indole-3-acetic acid (IAA), alpha-naphthaleneacetic acid (NAA) and 4-chlorophenoxyacetic acid (4-CA). The optimum separation was achieved with 20 mM borate buffer at pH 10.00 containing 0.005% (w/v) of HDB. The applied voltage was -25 kV and the capillary temperature was kept constant at 25 degrees C. Salicylic acid was used as internal standard for quantification. The calibration dependencies exhibited good linearity within the ratios of the concentrations of standard samples and internal standard and the ratios of the peak areas of samples and internal standard. The correlation coefficients were from 0.9952 to 0.9997. The relative standard deviations of migration times and peak areas were < 1.93 and 6.84%, respectively. The effects of buffer pH, the concentration of HDB and the voltage on the resolution were studied systematically. By this method, the contents of plant hormone in biofertilizer were successfully determined within 7 min, with satisfactory repeatability and recovery.

Nitrogen Dioxide-Sensing Properties at Room Temperature of Metal Oxide-Modified Graphene Composite via One-Step Hydrothermal Method

NASA Astrophysics Data System (ADS)

Zhang, Dongzhi; Liu, Jingjing; Xia, Bokai

2016-08-01

A metal oxide/graphene composite film-based sensor toward room-temperature detection of ppm-level nitrogen dioxide (NO2) gas has been demonstrated. The sensor prototype was constructed on a PCB substrate with microelectrodes, and a tin oxide-reduced graphene oxide (SnO2-rGO) composite as sensing film was prepared by one-step hydrothermal synthesis of tin tetrachloride pentahydrate solution in the presence of graphene oxide (GO). The SnO2-rGO hybrid composite was examined by scanning electron microscope and x-ray diffraction (XRD). The gas sensing properties of the SnO2-rGO composite were investigated at room temperature by exposing it to a wide concentration ranging from 1 ppm to 2000 ppm toward NO2 gas. The experiment results showed that the sensor exhibited a high response, superior selectivity, good repeatability, rapid response/recovery characteristics and low detection limit of 1 ppm, which exceeded that of a pure rGO sensor. The gas sensing mechanisms of the proposed sensor toward NO2 were possibly attributed to the nano-hybrid structures and n- p heterojunctions created at the interface of the SnO2 nanocrystals and rGO nanosheets.

Synthesis of carbon nanotube-nickel nanocomposites using atomic layer deposition for high-performance non-enzymatic glucose sensing.

PubMed

Choi, Taejin; Kim, Soo Hyeon; Lee, Chang Wan; Kim, Hangil; Choi, Sang-Kyung; Kim, Soo-Hyun; Kim, Eunkyoung; Park, Jusang; Kim, Hyungjun

2015-01-15

A useful strategy has been developed to fabricate carbon-nanotube-nickel (CNT-Ni) nanocomposites through atomic layer deposition (ALD) of Ni and chemical vapor deposition (CVD) of functionalized CNTs. Various techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), were used to characterize the morphology and the structure of as-prepared samples. It was confirmed that the products possess uniform Ni nanoparticles that are constructed by finely controlled deposition of Ni onto oxygen or bromine functionalized CNT surface. Electrochemical studies indicate that the CNT-Ni nanocomposites exhibit high electrocatalytic activity for glucose oxidation in alkaline solutions, which enables the products to be used in enzyme-free electrochemical sensors for glucose determination. It was demonstrated that the CNT-Ni nanocomposite-based glucose biosensor offers a variety of merits, such as a wide linear response window for glucose concentrations of 5 μM-2 mM, short response time (3 s), a low detection limit (2 μM), high sensitivity (1384.1 μA mM(-1) cm(-2)), and good selectivity and repeatability. Copyright © 2014 Elsevier B.V. All rights reserved.

Ion-selective gold-thiol film on integrated screen-printed electrodes for analysis of Cu(II) ions.

PubMed

Li, Meng; Zhou, Hao; Shi, Lei; Li, Da-Wei; Long, Yi-Tao

2014-02-07

A novel type of ion-selective electrode (ISE) was manufactured for detecting trace amounts of Cu(II) ions. The basic substrates of ISE were fabricated using screen-printing technology, which could produce disposable electrodes on a large-scale with good repeatability. Moreover, the printed integrated three-electrode system of ISE could be directly used to read out the open-circuit potentials by a handheld device through a USB port. The ion-selective film was composed of gold nanorods (GNRs) and 6-(bis(pyridin-2-ylmethyl)amino)hexane-1-thiol (compound ), which were layer-by-layer modified on the electrode through an easily controlled self-assembly method. Compound contained the 2,2'-dipyridylamine (dpa) group that could coordinate with Cu(II) ions to form a 2 : 1 complex, therefore the screen-printed ISEs exhibited Nernstian potentiometric responses to Cu(II) ions with a detection limit of 6.3 × 10(-7) mol L(-1) over the range of 1.0 × 10(-6) to 1.0 × 10(-2) mol L(-1). The easily prepared screen-printed ion-selective electrode reported here was appropriate for in field analysis and pollutant detection in remote environments.

Acetylene Gas-Sensing Properties of Layer-by-Layer Self-Assembled Ag-Decorated Tin Dioxide/Graphene Nanocomposite Film

PubMed Central

Jiang, Chuanxing; Yin, Nailiang; Yao, Yao; Shaymurat, Talgar; Zhou, Xiaoyan

2017-01-01

This paper demonstrates an acetylene gas sensor based on an Ag-decorated tin dioxide/reduced graphene oxide (Ag–SnO2/rGO) nanocomposite film, prepared by layer-by-layer (LbL) self-assembly technology. The as-prepared Ag–SnO2/rGO nanocomposite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectrum. The acetylene sensing properties were investigated using different working temperatures and gas concentrations. An optimal temperature of 90 °C was determined, and the Ag–SnO2/rGO nanocomposite sensor exhibited excellent sensing behaviors towards acetylene, in terms of response, repeatability, stability and response/recovery characteristics, which were superior to the pure SnO2 and SnO2/rGO film sensors. The sensing mechanism of the Ag–SnO2/rGO sensor was attributed to the synergistic effect of the ternary nanomaterials, and the heterojunctions created at the interfaces between SnO2 and rGO. This work indicates that the Ag–SnO2/rGO nanocomposite is a good candidate for constructing a low-temperature acetylene sensor. PMID:28927021

Synthesis and Application of Pyrrolidone-containing Shale Inhibitors

NASA Astrophysics Data System (ADS)

Liu, Yonggui; Hou, Jie; Zhang, Yang; Yan, Jing; Song, Tao; Xu, Yongjun

2018-03-01

New generation polyamine inhibitors are amino-terminated polyethers with excellent inhibiting capabilities; they play a key role in borehole stabilization and reservoir protection. However, polyamine inhibitors are limited by their poor thermal stability, which can be attributed to the presence of ether bonds in their molecular structures. We propose a three-step synthesis approach fora novel pyrrolidone-containing polyamine inhibitor (DYNP) by introducing N-vinyl-2-pyrrolidone (NVP) on divinyloxyethane. This polyamine inhibitor exhibits an optimized molecular structure and has enhanced heat resistance. Characterizations by infrared (IR) spectroscopy and evaluation tests demonstrate several advantages of DYNP inhibitors, including excellent inhibiting capability (superior to similar materials such as polyamines), improved heat resistance (reasonable stability at temperatures up to 240°C), and good compatibility with both fresh water and salt water drilling fluids. These can be attributed to the presence of considerable amounts of amino groups in the repeating unit of DYNP molecules. The DYNP inhibitor was applied in over 20 boreholes in tight oil blocks in Daqing Oilfield to relieve hydration of formations with high shale contents. For instance, drilling in the 2033.5m horizontal section of Dragon 2 borehole was smooth, with a borehole diameter expansion ratio below 10%.

Determination of γ-hydroxybutyrate in human urine samples by ion exclusion and ion exchange two-dimensional chromatography system.

PubMed

Liu, Junwei; Deng, Zhifen; Zhu, Zuoyi; Wang, Yong; Wang, Guoqing; Sun, Yu-An; Zhu, Yan

2017-12-15

A two-dimensional ion chromatography system was developed for the determination of γ-hydroxybutyrate (GHB) in human urine samples. Ion exclusion chromatography was used in the first dimensional separation for elimination of urine matrices and detection of GHB above 10mgL -1 , ion exchange chromatography was used in the second dimensional separation via column-switching technique for detection of GHB above 0.08mgL -1 . Under the optimized chromatographic conditions, the ion exclusion and ion exchange chromatography separation system exhibited satisfactory repeatability (RSD<3.1%, n=6) and good linearity in the range of 50-1000mgL -1 and 0.5-100mgL -1 , respectively. By this method, concentrations of GHB in the selected human urine samples were detected in the range of 0-1.57mgL -1 . The urine sample containing 0.89mgL -1 GHB was selected to evaluate the accuracy; the spiked recoveries of GHB were 95.9-102.8%. The results showed that the two-dimensional ion chromatography system was convenient and practical for the determination of GHB in human urine samples. Copyright © 2017 Elsevier B.V. All rights reserved.

A highly sensitive hydrogen sensor with gas selectivity using a PMMA membrane-coated Pd nanoparticle/single-layer graphene hybrid.

PubMed

Hong, Juree; Lee, Sanggeun; Seo, Jungmok; Pyo, Soonjae; Kim, Jongbaeg; Lee, Taeyoon

2015-02-18

A polymer membrane-coated palladium (Pd) nanoparticle (NP)/single-layer graphene (SLG) hybrid sensor was fabricated for highly sensitive hydrogen gas (H2) sensing with gas selectivity. Pd NPs were deposited on SLG via the galvanic displacement reaction between graphene-buffered copper (Cu) and Pd ion. During the galvanic displacement reaction, graphene was used as a buffer layer, which transports electrons from Cu for Pd to nucleate on the SLG surface. The deposited Pd NPs on the SLG surface were well-distributed with high uniformity and low defects. The Pd NP/SLG hybrid was then coated with polymer membrane layer for the selective filtration of H2. Because of the selective H2 filtration effect of the polymer membrane layer, the sensor had no responses to methane, carbon monoxide, or nitrogen dioxide gas. On the contrary, the PMMA/Pd NP/SLG hybrid sensor exhibited a good response to exposure to 2% H2: on average, 66.37% response within 1.81 min and recovery within 5.52 min. In addition, reliable and repeatable sensing behaviors were obtained when the sensor was exposed to different H2 concentrations ranging from 0.025 to 2%.

Flexible and High-Performance Amorphous Indium Zinc Oxide Thin-Film Transistor Using Low-Temperature Atomic Layer Deposition.

PubMed

Sheng, Jiazhen; Lee, Hwan-Jae; Oh, Saeroonter; Park, Jin-Seong

2016-12-14

Amorphous indium zinc oxide (IZO) thin films were deposited at different temperatures, by atomic layer deposition (ALD) using [1,1,1-trimethyl-N-(trimethylsilyl)silanaminato]indium (INCA-1) as the indium precursor, diethlzinc (DEZ) as the zinc precursor, and hydrogen peroxide (H 2 O 2 ) as the reactant. The ALD process of IZO deposition was carried by repeated supercycles, including one cycle of indium oxide (In 2 O 3 ) and one cycle of zinc oxide (ZnO). The IZO growth rate deviates from the sum of the respective In 2 O 3 and ZnO growth rates at ALD growth temperatures of 150, 175, and 200 °C. We propose growth temperature-dependent surface reactions during the In 2 O 3 cycle that correspond with the growth-rate results. Thin-film transistors (TFTs) were fabricated with the ALD-grown IZO thin films as the active layer. The amorphous IZO TFTs exhibited high mobility of 42.1 cm 2 V -1 s -1 and good positive bias temperature stress stability. Finally, flexible IZO TFT was successfully fabricated on a polyimide substrate without performance degradation, showing the great potential of ALD-grown TFTs for flexible display applications.

Experimental saltwater intrusion in coastal aquifers using automated image analysis: Applications to homogeneous aquifers

NASA Astrophysics Data System (ADS)

Robinson, G.; Ahmed, Ashraf A.; Hamill, G. A.

2016-07-01

This paper presents the applications of a novel methodology to quantify saltwater intrusion parameters in laboratory-scale experiments. The methodology uses an automated image analysis procedure, minimising manual inputs and the subsequent systematic errors that can be introduced. This allowed the quantification of the width of the mixing zone which is difficult to measure in experimental methods that are based on visual observations. Glass beads of different grain sizes were tested for both steady-state and transient conditions. The transient results showed good correlation between experimental and numerical intrusion rates. The experimental intrusion rates revealed that the saltwater wedge reached a steady state condition sooner while receding than advancing. The hydrodynamics of the experimental mixing zone exhibited similar traits; a greater increase in the width of the mixing zone was observed in the receding saltwater wedge, which indicates faster fluid velocities and higher dispersion. The angle of intrusion analysis revealed the formation of a volume of diluted saltwater at the toe position when the saltwater wedge is prompted to recede. In addition, results of different physical repeats of the experiment produced an average coefficient of variation less than 0.18 of the measured toe length and width of the mixing zone.

Flexible Strain Sensor Based on Layer-by-Layer Self-Assembled Graphene/Polymer Nanocomposite Membrane and Its Sensing Properties

NASA Astrophysics Data System (ADS)

Zhang, Dongzhi; Jiang, Chuanxing; Tong, Jun; Zong, Xiaoqi; Hu, Wei

2018-04-01

Graphene is a potential building block for next generation electronic devices including field-effect transistors, chemical sensors, and radio frequency switches. Investigations of strain application of graphene-based films have emerged in recent years, but the challenges in synthesis and processing achieving control over its fabrication constitute the main obstacles towards device applications. This work presents an alternative approach, layer-by-layer self-assembly, allowing a controllable fabrication of graphene/polymer film strain sensor on flexible substrates of polyimide with interdigital electrodes. Carboxylated graphene and poly (diallyldimethylammonium chloride) (PDDA) were exploited to form hierarchical nanostructure due to electrostatic action. The morphology and structure of the film were inspected by using scanning electron microscopy, x-ray diffraction and Fourier transform infrared spectroscopy. The strain-sensing properties of the graphene/PDDA film sensor were investigated through tuning micrometer caliper exertion and a PC-assisted piezoresistive measurement system. Experimental result shows that the sensor exhibited not only excellent response and reversibility behavior as a function of deflection, but also good repeatability and acceptable linearity. The strain-sensing mechanism of the proposed sensor was attributed to the electrical resistance change resulted from piezoresistive effect.

Continuous and scalable fabrication of bioinspired dry adhesives via a roll-to-roll process with modulated ultraviolet-curable resin.

PubMed

Yi, Hoon; Hwang, Insol; Lee, Jeong Hyeon; Lee, Dael; Lim, Haneol; Tahk, Dongha; Sung, Minho; Bae, Won-Gyu; Choi, Se-Jin; Kwak, Moon Kyu; Jeong, Hoon Eui

2014-08-27

A simple yet scalable strategy for fabricating dry adhesives with mushroom-shaped micropillars is achieved by a combination of the roll-to-roll process and modulated UV-curable elastic poly(urethane acrylate) (e-PUA) resin. The e-PUA combines the major benefits of commercial PUA and poly(dimethylsiloxane) (PDMS). It not only can be cured within a few seconds like commercial PUA but also possesses good mechanical properties comparable to those of PDMS. A roll-type fabrication system equipped with a rollable mold and a UV exposure unit is also developed for the continuous process. By integrating the roll-to-roll process with the e-PUA, dry adhesives with spatulate tips in the form of a thin flexible film can be generated in a highly continuous and scalable manner. The fabricated dry adhesives with mushroom-shaped microstructures exhibit a strong pull-off strength of up to ∼38.7 N cm(-2) on the glass surface as well as high durability without any noticeable degradation. Furthermore, an automated substrate transportation system equipped with the dry adhesives can transport a 300 mm Si wafer over 10,000 repeating cycles with high accuracy.

Porous and single-crystalline ZnO nanobelts: fabrication with annealing precursor nanobelts, and gas-sensing and optoelectronic performance

NASA Astrophysics Data System (ADS)

Jin, Xiao-Bo; Li, Yi-Xiang; Su, Yao; Guo, Zheng; Gu, Cui-Ping; Huang, Jia-Rui; Meng, Fan-Li; Huang, Xing-Jiu; Li, Min-Qiang; Liu, Jin-Huai

2016-09-01

Porous and single-crystalline ZnO nanobelts have been prepared through annealing precursors of ZnSe · 0.5N2H4 well-defined and smooth nanobelts, which have been synthesized via a simple hydrothermal method. The composition and morphology evolutions with the calcination temperatures have been investigated in detail for as-prepared precursor nanobelts, suggesting that they can be easily transformed into ZnO nanobelts by preserving their initial morphology via calcination in air. In contrast, the obtained ZnO nanobelts are densely porous, owing to the thermal decomposition and oxidization of the precursor nanobelts. More importantly, the achieved porous ZnO nanobelts are single-crystalline, different from previously reported ones. Motivated by the intrinsic properties of the porous structure and good electronic transporting ability of single crystals, their gas-sensing performance has been further explored. It is demonstrated that porous ZnO single-crystalline nanobelts exhibit high response and repeatability toward volatile organic compounds, such as ethanol and acetone, with a short response/recovery time. Furthermore, their optoelectronic behaviors indicate that they can be promisingly employed to fabricate photoelectrochemical sensors.

Graphene oxide bonded fused-silica fiber for solid-phase microextraction-gas chromatography of polycyclic aromatic hydrocarbons in water.

PubMed

Xu, Lili; Feng, Juanjuan; Li, Jubai; Liu, Xia; Jiang, Shengxiang

2012-01-01

A novel chemically bonded graphene oxide/fused-silica fiber was prepared and applied in solid-phase microextraction of six polycyclic aromatic hydrocarbons from water samples coupled with gas chromatography. It exhibited high extraction efficiency and excellent stability. Effects of extraction time, extraction temperature, ionic strength, stirring rate and desorption conditions were investigated and optimized in our work. Detection limits to the six polycyclic aromatic hydrocarbons were less than 0.08 μg/L, and their calibration curves were all linear (R(2)≥0.9954) in the range from 0.05 to 200 μg/L. Single fiber repeatability and fiber-to-fiber reproducibility were less than 6.13 and 15.87%, respectively. This novel fiber was then utilized to analyze two real water samples from the Yellow River and local waterworks, and the recoveries of samples spiked at 1 and 10 μg/L ranged from 84.48 to 118.24%. Compared with other coating materials, this graphene oxide-coated fiber showed many advantages: wide linear range, low detection limit, and good stability in acid, alkali, organic solutions and at high temperature. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inhibitory Activities of Phenolic Compounds Isolated from Adina rubella Leaves Against 5α-Reductase Associated with Benign Prostatic Hypertrophy.

PubMed

Yin, Jun; Heo, Jun Hyeok; Hwang, Yoon Jeong; Le, Thi Tam; Lee, Min Won

2016-07-07

Adina rubella Hance (AR), a plant native to Korea, has been used as traditional medicine for dysentery, eczema, intoxication, and external hemorrhages. Previous phytochemical studies of AR have reported several components, including terpenoids, phenolics, and alkaloids. The current study evaluated the anti-oxidative and anti-inflammatory activities and 5α-reductase inhibition of isolated compounds of AR leaves to find a potential therapeutic agent for benign prostatic hypertrophy (BPH). Repeated chromatographic isolation of an 80% acetone extract of AR leaves yielded seven phenolic compounds: caffeic acid (1), chlorogenic acid (2), methyl chlorogenate (3), quercetin-3-rutinoside (4), kaempferol-3-O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (5), hyperoside (6), and grandifloroside (7). Compound 7 is a novel compound in AR. Caffeoyl derivatives 1-3 and 7 showed good anti-oxidative activities. In particular, caffeic acid (1) and grandifloroside (7) showed potent anti-inflammatory activities, and 7 also exhibited potent inhibitory activity against TNF-α and 5α-reductase. Our results show that the extract and grandifloroside (7) from leaves of AR might be developed as a source of potent anti-oxidative and anti-inflammatory agents and therapeutic agent for BPH.

The woven fiber organic electrochemical transistors based on polypyrrole nanowires/reduced graphene oxide composites for glucose sensing.

PubMed

Wang, Yuedan; Qing, Xing; Zhou, Quan; Zhang, Yang; Liu, Qiongzhen; Liu, Ke; Wang, Wenwen; Li, Mufang; Lu, Zhentan; Chen, Yuanli; Wang, Dong

2017-09-15

Novel woven fiber organic electrochemical transistors based on polypyrrole (PPy) nanowires and reduced graphene oxide (rGO) have been prepared. SEM revealed that the introduction of rGO nanosheets could induce the growth and increase the amount of PPy nanowires. Moreover, it could enhance the electrical performance of fiber transistors. The hybrid transistors showed high on/off ratio of 10 2 , fast switch speed, and long cycling stability. The glucose sensors based on the fiber organic electrochemical transistors have also been investigated, which exhibited outstanding sensitivity, as high as 0.773 NCR/decade, with a response time as fast as 0.5s, a linear range of 1nM to 5μM, a low detection concentration as well as good repeatability. In addition, the glucose could be selectively detected in the presence of ascorbic acid and uric acid interferences. The reliability of the proposed glucose sensor was evaluated in real samples of rabbit blood. All the results indicate that the novel fiber transistors pave the way for portable and wearable electronics devices, which have a promising future for healthcare and biological applications. Copyright © 2017 Elsevier B.V. All rights reserved.

40 CFR 1065.310 - Torque calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... maintenance. Use good engineering judgment to repeat the calibration. Follow the torque transducer... the U.S. National Oceanographic and Atmospheric Administration's surface gravity prediction Web site at http://www.ngs.noaa.gov/cgi-bin/grav_pdx.prl. If this Web site is unavailable, you may use the...

40 CFR 1065.310 - Torque calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... maintenance. Use good engineering judgment to repeat the calibration. Follow the torque transducer... the U.S. National Oceanographic and Atmospheric Administration's surface gravity prediction Web site at http://www.ngs.noaa.gov/cgi-bin/grav_pdx.prl. If this Web site is unavailable, you may use the...

A surrealistic mega-analysis of redisorganization theories

PubMed Central

Oxman, Andrew D; Sackett, David L; Chalmers, Iain; Prescott, Trine E

2005-01-01

Background We are sick and tired of being redisorganized. Objective To systematically review the empirical evidence for organizational theories and repeated reorganizations. Methods We did not find anything worth reading, other than Dilbert, so we fantasized. Unfortunately, our fantasies may well resemble many people's realities. We are sorry about this, but it is not our fault. Results We discovered many reasons for repeated reorganizations, the most common being ‘no good reason’. We estimated that trillions of dollars are being spent on strategic and organizational planning activities each year, thus providing lots of good reasons for hundreds of thousands of people, including us, to get into the business. New leaders who are intoxicated with the prospect of change further fuel perpetual cycles of redisorganization. We identified eight indicators of successful redisorganizations, including large consultancy fees paid to friends and relatives. Conclusions We propose the establishment of ethics committees to review all future redisorganization proposals in order to put a stop to uncontrolled, unplanned experimentation inflicted on providers and users of the health services. PMID:16319441

Analysis and discussion on the experimental data of electrolyte analyzer

NASA Astrophysics Data System (ADS)

Dong, XinYu; Jiang, JunJie; Liu, MengJun; Li, Weiwei

2018-06-01

In the subsequent verification of electrolyte analyzer, we found that the instrument can achieve good repeatability and stability in repeated measurements with a short period of time, in line with the requirements of verification regulation of linear error and cross contamination rate, but the phenomenon of large indication error is very common, the measurement results of different manufacturers have great difference, in order to find and solve this problem, help enterprises to improve quality of product, to obtain accurate and reliable measurement data, we conducted the experimental evaluation of electrolyte analyzer, and the data were analyzed by statistical analysis.

Imprints of superfluidity on magnetoelastic quasiperiodic oscillations of soft gamma-ray repeaters.

PubMed

Gabler, Michael; Cerdá-Durán, Pablo; Stergioulas, Nikolaos; Font, José A; Müller, Ewald

2013-11-22

Our numerical simulations show that axisymmetric, torsional, magnetoelastic oscillations of magnetars with a superfluid core can explain the whole range of observed quasiperiodic oscillations (QPOs) in the giant flares of soft gamma-ray repeaters. There exist constant phase QPOs at f is < or approximately equal to 150 Hz and resonantly excited high-frequency QPOs (f>500 Hz), in good agreement with observations. The range of magnetic field strengths required to match the observed QPO frequencies agrees with that from spin-down estimates. These results suggest that there is at least one superfluid species in magnetar cores.

Processing of Advanced Ceramics Which Have Potential for Use in Gas Turbine Aero Engines

DTIC Science & Technology

1989-02-01

reaons . Details on the availability of these publications may be obtained from: Graphics Section, National Research Council Canada, National...have been produced by hot isostatic pressing (HIP’ing) have good potential to be used as hot section components in gas turbine aero engines. This...Alumina, for example, maintains good corrosion resistance, good stiffness, and good strength at high temperatures, but exhibits very poor thermal shock

Repeatedly pairing vagus nerve stimulation with a movement reorganizes primary motor cortex.

PubMed

Porter, Benjamin A; Khodaparast, Navid; Fayyaz, Tabbassum; Cheung, Ryan J; Ahmed, Syed S; Vrana, William A; Rennaker, Robert L; Kilgard, Michael P

2012-10-01

Although sensory and motor systems support different functions, both systems exhibit experience-dependent cortical plasticity under similar conditions. If mechanisms regulating cortical plasticity are common to sensory and motor cortices, then methods generating plasticity in sensory cortex should be effective in motor cortex. Repeatedly pairing a tone with a brief period of vagus nerve stimulation (VNS) increases the proportion of primary auditory cortex responding to the paired tone (Engineer ND, Riley JR, Seale JD, Vrana WA, Shetake J, Sudanagunta SP, Borland MS, Kilgard MP. 2011. Reversing pathological neural activity using targeted plasticity. Nature. 470:101-104). In this study, we predicted that repeatedly pairing VNS with a specific movement would result in an increased representation of that movement in primary motor cortex. To test this hypothesis, we paired VNS with movements of the distal or proximal forelimb in 2 groups of rats. After 5 days of VNS movement pairing, intracranial microstimulation was used to quantify the organization of primary motor cortex. Larger cortical areas were associated with movements paired with VNS. Rats receiving identical motor training without VNS pairing did not exhibit motor cortex map plasticity. These results suggest that pairing VNS with specific events may act as a general method for increasing cortical representations of those events. VNS movement pairing could provide a new approach for treating disorders associated with abnormal movement representations.

An Ankyrin Repeat-Containing Protein, Characterized as a Ubiquitin Ligase, Is Closely Associated with Membrane-Enclosed Organelles and Required for Pollen Germination and Pollen Tube Growth in Lily1[W

PubMed Central

Huang, Jian; Chen, Feng; Del Casino, Cecilia; Autino, Antonella; Shen, Mouhua; Yuan, Shuai; Peng, Jia; Shi, Hexin; Wang, Chen; Cresti, Mauro; Li, Yiqin

2006-01-01

Exhibiting rapid polarized growth, the pollen tube delivers the male gametes into the ovule for fertilization in higher plants. To get an overall picture of gene expression during pollen germination and pollen tube growth, we profiled the transcription patterns of 1,536 pollen cDNAs from lily (Lilium longiflorum) by microarray. Among those that exhibited significant differential expression, a cDNA named lily ankyrin repeat-containing protein (LlANK) was thoroughly studied. The full-length LlANK cDNA sequence predicts a protein containing five tandem ankyrin repeats and a RING zinc-finger domain. The LlANK protein possesses ubiquitin ligase activity in vitro. RNA blots demonstrated that LlANK transcript is present in mature pollen and its level, interestingly contrary to most pollen mRNAs, up-regulated significantly during pollen germination and pollen tube growth. When fused with green fluorescent protein and transiently expressed in pollen, LlANK was found dominantly associated with membrane-enclosed organelles as well as the generative cell. Overexpression of LlANK, however, led to abnormal growth of the pollen tube. On the other hand, transient silencing of LlANK impaired pollen germination and tube growth. Taken together, these results showed that LlANK is a ubiquitin ligase associated with membrane-enclosed organelles and required for polarized pollen tube growth. PMID:16461387

Tissue-specific methylation differences and cognitive function in fragile X premutation females

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

Allingham-Hawkins, D.J.; Babul, R.; Chitayat, D.

1996-08-09

Tissue-specific variation in (CGG){sub n} repeat size and methylation status of the FMR1 gene was investigated in 17 female premutation carriers. Minor variation in premutation repeat size among leukocyte, lymphoblast, and fibroblast tissues was noted in some subjects. One subject exhibited a premutation size allele of (CGG){sub 64} in leukocyte and fibroblast tissues by polymerase chain reaction analysis but a normal-size allele of (CGG){sub 46} in lymphoblast cells, suggesting low-level mosaicism in blood and clonality of the lymphoblast cell line. Six subjects exhibited differences in methylation pattern between leukocytes and lymphoblasts but not between leukocytes and fibroblasts, whereas 2 subjectsmore » showed large differences in methylation pattern between leukocytes and fibroblasts. Cognitive function was studied in 14 subjects using the Wechsler Adult Intelligence Scale-Revised. Mean Verbal and Performance IQs were well within the average range as was the mean Full Scale IQ; nevertheless, a trend toward lower Performance IQ compared with Verbal IQ was observed. No significant correlation was apparent between Full Scale IQ and (CGG){sub n} repeat size; however, a significant positive correlation was observed between Full Scale IQ and the proportion of the active X carrying the normal FMR1 allele in fibroblasts but not in leukocytes or lymphoblasts. 24 refs., 1 fig., 2 tabs.« less

Evaluation of reliability and validity of three dental color-matching devices.

PubMed

Tsiliagkou, Aikaterini; Diamantopoulou, Sofia; Papazoglou, Efstratios; Kakaboura, Afrodite

2016-01-01

To assess the repeatability and accuracy of three dental color-matching devices under standardized and freehand measurement conditions. Two shade guides (Vita Classical A1-D4, Vita; and Vita Toothguide 3D-Master, Vita), and three color-matching devices (Easyshade, Vita; SpectroShade, MHT Optic Research; and ShadeVision, X-Rite) were used. Five shade tabs were selected from the Vita Classical A1-D4 (A2, A3.5, B1, C4, D3), and five from the Vita Toothguide 3D-Master (1M1, 2R1.5, 3M2, 4L2.5, 5M3) shade guides. Each shade tab was recorded 15 continuous, repeated times with each device under two different measurement conditions (standardized, and freehand). Both qualitative (color shade) and quantitative (L, a, and b) color characteristics were recorded. The color difference (ΔE) of each recorded value with the known values of the shade tab was calculated. The repeatability of each device was evaluated by the coefficient of variance. The accuracy of each device was determined by comparing the recorded values with the known values of the reference shade tab (one sample t test; α = 0.05). The agreement between the recorded shade and the reference shade tab was calculated. The influence of the parameters (devices and conditions) on the parameter ΔE was investigated (two-way ANOVA). Comparison of the devices was performed with Bonferroni pairwise post-hoc analysis. Under standardized conditions, repeatability of all three devices was very good, except for ShadeVision with Vita Classical A1-D4. Accuracy ranged from good to fair, depending on the device and the shade guide. Under freehand conditions, repeatability and accuracy for Easyshade and ShadeVision were negatively influenced, but not for SpectroShade, regardless of the shade guide. Based on the total of the color parameters assessed per device, SpectroShade was the most reliable of the three color-matching devices studied.

Temporal and spatiotemporal variability in comprehensive forearm skin microcirculation assessment during occlusion protocols.

PubMed

Strömberg, Tomas; Sjöberg, Folke; Bergstrand, Sara

2017-09-01

Forearm skin hyperemia during release after brachial occlusion has been proposed for evaluating peripheral arterial disease and endothelial dysfunction. We used a novel fiberoptic system integrating Laser Doppler Flowmetry and Diffuse Reflectance Spectroscopy for a comprehensive pointwise model based microcirculation characterization. The aim was to evaluate and compare the temporal and the spatiotemporal variabilities in forearm skin microcirculation parameters (speed resolved perfusion; low speed <1mm/s, Perf SR, <1 ; mid-speed 1-10mm/s, high speed >10mm/s, and total perfusion (Perf SR, tot ); the concentration and oxygenation of red blood cells, C RBC and S O2 ). Ten healthy subjects underwent arterial and venous forearm occlusions (AO, VO), repeated within one week. The repeatability was calculated as the coefficient of variation (CV) and the agreement as the intra-class correlation coefficient (ICC). The temporal CVs for conventional perfusion, Perf conv , Perf SR, tot , C RBC and S O2 were 14%, 12%, 9% and 9%, respectively, while the ICC were >0.75 (excellent). The perfusion measures generally had a higher spatiotemporal than temporal variability, which was not the case for S O2 and C RBC . The corresponding spatiotemporal CVs were 33%, 32%, 18% and 15%, respectively. During VO, C RBC had a CV<35% and ICC>0.40 (fair-good), and after release this was the case for C RBC (AO and VO), S O2 (VO) and Perf SR, <1 (VO). In conclusion, the skin microcirculation parameters showed excellent temporal repeatability, while the spatiotemporal repeatability especially for perfusion was poorer. The parameters with acceptable repeatability and fair-good agreement were: C RBC during and after release of VO, the Perf SR, <1 after release of VO, the S O2 and the C RBC after release of AO. However, the value of these parameters in discriminating endothelial function remains to be studied. Copyright © 2017 Elsevier Inc. All rights reserved.

[Preparation and performance characterization of gold nanoparticles modified chiral capillary electrochromatography stationary phase].

PubMed

Xiong, Lele; Li, Ruijun; Ji, Yibing

2017-07-08

Gold nanoparticles (GNPs, 15 nm) were prepared and introduced to amino groups derived silica monolithic column. Bovine serum albumin (BSA) was immobilized via covalent modification method onto the carboxylic functionalized GNPs to afford chiral stationary phase (CSP) for enantioseparation. GNPs were well dispersed and successfully incorporated onto the columns with the contents as high as 17.18% by characterization method such as transmission electron microscopy (TEM), ultraviolet (UV)-visible absorption spectra and scanning electron microscopy (SEM). The preparation conditions of the BSA modified CSP were optimized and 10% (v/v) 3-aminopropyltriethoxysilane (APTES) and 15 g/L BSA were selected as appropriate reaction conditions. The enantioseparation performance of the BSA modified CSP has been investigated by capillary electrochromatography (CEC). Enantiomers of tryptophan, ephedrine and atenolol were resolved, and the baseline separation of tryptophan was achieved. Meanwhile, the influences of pH value, buffer concentrations and applied voltages used on the chiral separation were studied, and the optimal separation conditions were 10 mmol/L phosphate buffer at pH 7.4 and 15 kV applied voltages. In comparison with the BSA modified CSP prepared by physical adsorption, the CSP prepared by covalent modification method had better separation results, and the analytes could be separated directly without pre-column derivatization. In addition, the prepared BSA modified CSP exhibited good run to run repeatability with relative standard deviations (RSDs) of the migration times and selectivity factors not more than 2.3% and 0.96%, respectively. This work offers a good thinking for modification with other proteins or other types of chiral selectors.

The feasibility and application of PPy in cathodic polarization antifouling.

PubMed

Jia, Meng-Yang; Zhang, Zhi-Ming; Yu, Liang-Min; Wang, Jia; Zheng, Tong-Tong

2018-04-01

Cathodic polarization antifouling deserves attention because of its environmentally friendly nature and good sustainability. It has been proven that cathodic voltages applied on metal substrates exhibit outstanding antifouling effects. However, most metals immersed in marine environment are protected by insulated anticorrosive coatings, restricting the cathodic polarization applied on metals. This study developed a conducting polypyrrole (PPy)/acrylic resin coating (σ = 0.18 Scm -1 ), which can be applied in cathodic polarization antifouling. The good stability and electro-activity of PPy in the negative polarity zone in alkalescent NaCl solution were verified by linear sweep voltammetry (LSV), chronoamperometry (CA), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), demonstrating the feasibility of PPy as cathodic polarization material. Furthermore, the antifouling effects of PPy/acrylicresin coating on 24-h old Escherichia coli bacteria (E. coli) which formed on PPy/acrylic resin-coated plastic plate were measured under different cathodic potentials and treatment time, characterized by fluorescent microscope. The results suggest that at cathodic potential around -0.5 V (vs. saturated calomel electrode (SCE)), there was little trace of attached bacteria on the substrate after 20 min of treatment. PPy/acrylicresin-coated substrates were also subjected to repeated cycles of biofilm formation and electrochemical removal, where high removal efficiencies were maintained throughout the total polarization process. Under these conditions, the generation of hydrogen peroxide is believed to be responsible for the antifouling effects because of causing oxidative damage to cells, suggesting the potential of the proposed technology for application on insulated surfaces in various industrial settings. Copyright © 2018 Elsevier B.V. All rights reserved.

Towards field detection of polycyclic aromatic hydrocarbons (PAHs) in environment water using a self-assembled SERS sensor

NASA Astrophysics Data System (ADS)

Yan, Xia; Shi, Xiaofeng; Yang, Jie; Zhang, Xu; Jia, Wenjie; Ma, Jun

2017-10-01

A self-assembled surface enhanced Raman scattering (SERS) sensor is reported in this paper. To achieve high sensitivity, a high sensitive SERS substrate and a high efficient self-constructed light path were made. The SERS substrate was composed by gold nanoparticles (AuNPs, pH=13), glycidyl methacrylate-ethylene dimethacrylate (GMA-EDMA) porous material and syringe filter. The substrate had a good repeatability, and the relative standard deviation (RSD) of the same substrate was less than 5%. The efficiency of the self-constructed light path is about two times better than RPB Y type reflection fiber when the energy density was roughly equal on samples. The size of the SERS sensor is 350×300×180 mm and the weight is 15 kg. Its miniaturization and portable can comply with the requirements of field detection. Besides, it has good sensitivity, stability and selectivity. For lab experiments, strong enhancements of Raman scattering from organic pollutant polycyclic aromatic hydrocarbons (PAHs) molecules were exhibited. The dependences of SERS intensities on concentrations of PAHs were investigated, and the results indicated that they revealed a satisfactory linear relationship in low concentrations. The limits of detection (LODs) of PAHs phenanthrene and fluorene are 8.3×10-10 mol/L and 7.1×10-10 mol/L respectively [signal to noise ratio (S/N) =3]. Based on this SERS sensor, signals of benzo (a) pyrene and pyrene were found in environmental water and the sensor would be an ideal candidate for field detection of PAHs.

Inter- and intraexaminer reliability of bitewing radiography and near-infrared light transillumination for proximal caries detection and assessment.

PubMed

Litzenburger, Friederike; Heck, Katrin; Pitchika, Vinay; Neuhaus, Klaus W; Jost, Fabian N; Hickel, Reinhard; Jablonski-Momeni, Anahita; Welk, Alexander; Lederer, Alexander; Kühnisch, Jan

2018-02-01

The purpose of this in vitro study was to evaluate the inter- and intraexaminer reliability of digital bitewing (DBW) radiography and near-infrared light transillumination (NIRT) for proximal caries detection and assessment in posterior teeth. From a pool of 85 patients, 100 corresponding pairs of DBW and NIRT images (~1/3 healthy, ~1/3 with enamel caries and ~1/3 with dentin caries) were chosen. 12 dentists with different professional status and clinical experience repeated the evaluation in two blinded cycles. Two experienced dentists provided a reference diagnosis after analysing all images independently. Statistical analysis included the calculation of simple (κ) and weighted Kappa (wκ) values as a measure of reliability. Logistic regression with a backward elimination model was used to investigate the influence of the diagnostic method, evaluation cycle, type of tooth, and clinical experience on reliability. Altogether, inter- and intraexaminer reliability exhibited good to excellent κ and wκ values for DBW radiography (Inter: κ = 0.60/ 0.63; wκ = 0.74/0.76; Intra: κ = 0.64; wκ = 0.77) and NIRT (Inter: κ = 0.74/0.64; wκ = 0.86/0.82; Intra: κ = 0.68; wκ = 0.84). The backward elimination model revealed NIRT to be significantly more reliable than DBW radiography. This study revealed a good to excellent inter- and intraexaminer reliability for proximal caries detection using DBW and NIRT images. The logistic regression analysis revealed significantly better reliability for NIRT. Additionally, the first evaluation cycle was more reliable according to the reference diagnoses.

Ethanol up-regulates nucleus accumbens neuronal activity dependent pentraxin (Narp): implications for alcohol-induced behavioral plasticity.

PubMed

Ary, Alexis W; Cozzoli, Debra K; Finn, Deborah A; Crabbe, John C; Dehoff, Marlin H; Worley, Paul F; Szumlinski, Karen K

2012-06-01

Neuronal activity dependent pentraxin (Narp) interacts with α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) glutamate receptors to facilitate excitatory synapse formation by aggregating them at established synapses. Alcohol is well-characterized to influence central glutamatergic transmission, including AMPA receptor function. Herein, we examined the influence of injected and ingested alcohol upon Narp protein expression, as well as basal Narp expression in mouse lines selectively bred for high blood alcohol concentrations under limited access conditions. Alcohol up-regulated accumbens Narp levels, concomitant with increases in levels of the GluR1 AMPA receptor subunit. However, accumbens Narp or GluR1 levels did not vary as a function of selectively bred genotype. We next employed a Narp knock-out (KO) strategy to begin to understand the behavioral relevance of alcohol-induced changes in protein expression in several assays of alcohol reward. Compared to wild-type mice, Narp KO animals: fail to escalate daily intake of high alcohol concentrations under free-access conditions; shift their preference away from high alcohol concentrations with repeated alcohol experience; exhibit a conditioned place-aversion in response to the repeated pairing of 3 g/kg alcohol with a distinct environment and fail to exhibit alcohol-induced locomotor hyperactivity following repeated alcohol treatment. Narp deletion did not influence the daily intake of either food or water, nor did it alter any aspect of spontaneous or alcohol-induced motor activity, including the development of tolerance to its motor-impairing effects with repeated treatment. Taken together, these data indicate that Narp induction, and presumably subsequent aggregation of AMPA receptors, may be important for neuroplasticity within limbic subcircuits mediating or maintaining the rewarding properties of alcohol. Published by Elsevier Inc.

Slip Behavior of the Queen Charlotte Plate Boundary Before and After the 2012, MW 7.8 Haida Gwaii Earthquake: Evidence From Repeating Earthquakes

NASA Astrophysics Data System (ADS)

Hayward, Tim W.; Bostock, Michael G.

2017-11-01

The Queen Charlotte plate boundary, near Haida Gwaii, B.C., includes the dextral, strike-slip, Queen Charlotte Fault (QCF) and the subduction interface between the downgoing Pacific and overriding North American plates. In this study, we present a comprehensive repeating earthquake catalog that represents an effective slip meter for both structures. The catalog comprises 712 individual earthquakes (0.3≤MW≤3.5) arranged into 224 repeating earthquake families on the basis of waveform similarity and source separation estimates from coda wave interferometry. We employ and extend existing relationships for repeating earthquake magnitudes and slips to provide cumulative slip histories for the QCF and subduction interface in six adjacent zones within the study area between 52.3°N and 53.8°N. We find evidence for creep on both faults; however, creep rates are significantly less than plate motion rates, which suggests partial locking of both faults. The QCF exhibits the highest degrees of locking south of 52.8°N, which indicates that the seismic hazard for a major strike-slip earthquake is highest in the southern part of the study area. The 28 October 2012, MW 7.8 Haida Gwaii thrust earthquake occurred in our study area and altered the slip dynamics of the plate boundary. The QCF is observed to undergo accelerated, right-lateral slip for 1-2 months following the earthquake. The subduction interface exhibits afterslip thrust motion that persists for the duration of the study period (i.e., 3 years and 2 months after the Haida Gwaii earthquake). Afterslip is greatest (5.7-8.4 cm/yr) on the periphery of the main rupture zone of the Haida Gwaii event.

Ethanol up-regulates nucleus accumbens neuronal activity dependent pentraxin (Narp): implications for alcohol-induced behavioral plasticity

PubMed Central

Ary, Alexis W.; Cozzoli, Debra K.; Finn, Deborah A.; Crabbe, John C.; Dehoff, Marlin H.; Worley, Paul F.; Szumlinski, Karen K.

2012-01-01

Neuronal activity-dependent pentraxin (Narp) interacts with α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) glutamate receptors to facilitate excitatory synapse formation by aggregating them at established synapses. Alcohol is well-characterized to influence central glutamatergic transmission, including AMPA receptor function. Herein, we examined the influence of injected and ingested alcohol upon Narp protein expression, as well as basal Narp expression in mouse lines selectively bred for high blood alcohol concentrations under limited access conditions. Alcohol up-regulated accumbens Narp levels, concomitant with increases in levels of the GluR1 AMPA receptor subunit. However, accumbens Narp or GluR1 levels did not vary as a function of selectively bred genotype. We next employed a Narp knock-out (KO) strategy to begin to understand the behavioral relevance of alcohol-induced changes in protein expression in several assays of alcohol reward. Compared to wild-type mice, Narp KO animals: fail to escalate daily intake of high alcohol concentrations under free-access conditions; shift their preference away from high alcohol concentrations with repeated alcohol experience; exhibit a conditioned place-aversion in response to the repeated pairing of 3 g/kg alcohol with a distinct environment and fail to exhibit alcohol-induced locomotor hyperactivity following repeated alcohol treatment. Narp deletion did not influence the daily intake of either food or water, nor did it alter any aspect of spontaneous or alcohol-induced motor activity, including the development of tolerance to its motor-impairing effects with repeated treatment. Taken together, these data indicate that Narp induction, and presumably subsequent aggregation of AMPA receptors, may be important for neuroplasticity within limbic subcircuits mediating or maintaining the rewarding properties of alcohol. PMID:22444953

Three hundred and eight nanometer excimer light therapy for alopecia universalis that is resistant to other treatments: A clinical study of 11 patients.

PubMed

Arakawa, Yukiyasu; Nomiyama, Tomoko; Katoh, Norito

2016-12-01

Three hundred and eight nanometer excimer light therapy has recently been reported to be effective against patchy alopecia areata (AA) in several clinical studies. However, these studies only included a few patients with severe forms of AA, and all of them exhibited poor outcomes. We further investigated the use of excimer light as a therapeutic option for cases of alopecia universalis (AU) that are resistant to other treatments. Eleven treatment-resistant AU patients were treated with a 308-nm excimer light at 2-week intervals for more than 16 sessions. Four patients achieved good responses and two patients exhibited poor responses. Three patients had Japanese skin type 1 and all of them achieved good responses. The radiation dose was increased until the patients exhibited marked erythema. The patients with Japanese skin type 3 who achieved good responses exhibited strong pigmentation at the irradiated sites. In conclusion, 308-nm excimer light therapy has significant effects on some AU patients who are resistant to other treatments and may be an alternative therapeutic option for AU. During the treatment of AU, high doses of radiation should be administrated until a strong inflammatory skin reaction is seen. © 2016 Japanese Dermatological Association.

Birth outcomes after induced abortion: a nationwide register-based study of first births in Finland.

PubMed

Klemetti, R; Gissler, M; Niinimäki, M; Hemminki, E

2012-11-01

Is the perinatal health of first-born children affected by the mother's previous induced abortion(s) (IAs)? Prior IAs, particularly repeat IAs, are correlated with an increased risk of some health problems at first birth; even in a country with good health care quality. A positive association between IA and risk of preterm birth or a dose-response effect has been found in some previous studies. Limited information and conflicting results on other infant outcomes are available. Nationwide register-based study including 300 858 first-time mothers during 1996-2008 in Finland. All the first-time mothers with a singleton birth (obtained from the Medical Birth Register) in the period 1996-2008 (n = 300 858) were linked to the Abortion Register for the period 1983-2008. Of the first-time mothers, 10.3% (n = 31 083) had one, 1.5% had two and 0.3% had three or more IAs. Most IAs were surgical (88%) performed before 12 weeks (91%) and carried out for social reasons (97%). After adjustment, perinatal deaths and very preterm birth (<28 gestational week) suggested worse outcomes after IA. Increased odds for very preterm birth were seen in all the subgroups and exhibited a dose-response relationship: 1.19 [95% confidence interval (CI) 0.98-1.44] after one IA, 1.69 (1.14-2.51) after two and 2.78 (1.48-5.24) after three IAs. Increased odds for preterm birth (<37 weeks) and low birthweight (<2500 g and <1500 g) were seen only among mothers with three or more IAs: 1.35 (1.07-1.71), 1.43 (1.12-1.84) and 2.25 (1.43-3.52), respectively. Observational studies like ours, however large and well-controlled, will not prove causality. In terms of public health and practical implications, health education should contain information of the potential health hazards of repeat IAs, including very preterm birth and low birthweight in subsequent pregnancies. Health care professionals should be informed about the potential risks of repeat IAs on infant outcomes in subsequent pregnancy. National Institute for Health and Welfare and the Academy of Finland. No competing interests.

The Mysteries of Real Materials

NASA Technical Reports Server (NTRS)

Laub, Bernard

2012-01-01

The presentation will consist of showing arc jet data mysterious to the modelers. It will show pictures from an arc jet test where a material (unidentified) exhibited a failure mode that nobody understands followed by thermocouple data from arc jet tests on another (unidentified) material of interest in which the T/Cs exhibit repeatable, consistent, fascinating yet frustrating response characteristics that have the modelers stumped. This all happens between RT and 200 F. Unless we figure out what the responsible phenomenology is and can model it, we can't size the TPS with any confidence.

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

Ding, Ling; Zhong, Jie-Cen; Qiu, Xing-Tai

Two series of lanthanide-carboxylates, [Ln(2,2′-dtba)(2,2′-Hdtba)(EtOH)]{sub n} (I:Ln=Eu(1a), Dy(1b)) and [Ln(2,2′-dtba)(2,2′-Hdtba)(4,4′-bpy){sub 0.5}]{sub n} (II:Ln=Eu(2a), Dy(2b), Tb(2c) 2,2′-H{sub 2}dtba=2,2′-dithiodibenzoic acid, 4,4′-bpy=4,4′-bipyridine) have been synthesized under hydrothermal conditions. Interestingly, the H{sub 2}dtba organic ligand was generated by in situ S–S reaction of 2-mercaptobenzoic acid. Compounds I and II possess different 2D layered structures based on similar 1D [Ln(2,2′-dtba)]{sup +} chains. Photoluminescence studies reveal that compounds I and II exhibit strong lanthanide characteristic emission bands. Remarkably, Compounds 1b and 2a both exhibit good photocatalytic activity for degradation of Rhodamine-B (Rh-B) under the simulated sunlight irradiation. - Graphical abstract: Two series of lanthanide-carboxylates have beenmore » in situ synthesized under hydrothermal conditions. The lanthanide-carboxylates exhibit strong lanthanide characteristic emission bands and good photocatalytic activity for degradation of Rhodamine-B. - Highlights: • 2D layered lanthanide-carboxylates with 2,2′-dithiodibenzoic acid. • In situ S–S reaction of 2-mercaptobenzoic acid under hydrothermal condition. • The Emission spectra of I and II exhibit the characteristic transition of lanthanide ions. • Compounds 1b and 2a exhibit good photocatalytic activity for degradation of Rhodamine-B.« less

Aging in bacteria, immortality or not-a critical review.

PubMed

Gómez, José M G

2010-12-01

Bacteria were traditionally thought to have a symmetrical binary fission without a clear distinction between soma and germ-line, being thus considered as immortal biological entities. Yet it has been recently described that bacteria also undergo replicative aging (RA). That is, they exhibit finite replicative abilities under good conditions to growth. The apparently initial indistinguishability of sibling cells after cytokinesis is broken. After division, the daughter cell that inherits the "old" pole present in the "mother cell" progressively exhibits a decline in its proliferative capacity with increasing cell pole age. This is a clear hallmark and phenotypic manifestation of a bona fide RA phenomenon in toto. While the exact molecular mechanism(s) underlying to this lost of replicative potential are not yet fully understood, the "old pole cell" is considered as an aging parent that in a repeatedly manner is able to produce rejuvenated offspring which inherit a resetting of the biological clock. On the order hand, bacteria exhibit in addition to this "mandatory" RA the dubbed conditional senescence (CS). CS is defined as a decline in cellular viability observed in arrested-growing bacteria populations, a phenomenon apparently not related to RA under growing active conditions. To understand bacterial aging, it is necessary to put it within the sociality-multicellularity framework. This is a new conceptual paradigm that expresses the natural reality of the bacterial world. From this more ecological perspective these bacterial aging phenomena probably should represent an insurance/bethedging anticipative survival strategy. This is underpinned in a self-generation of an appropriate level of populational phenotypic diversity. That is, bacterial aging could be considered a communitarian adaptive response to cope with different environmental stresses and threats. I have highlighted the necessity to construct an integrative conceptual framework to achieve a unified view of bacteria aging to answer this fundamental question: what are the reasons of bacterial aging?

Correlation between fibroin amino acid sequence and physical silk properties.

PubMed

Fedic, Robert; Zurovec, Michal; Sehnal, Frantisek

2003-09-12

The fiber properties of lepidopteran silk depend on the amino acid repeats that interact during H-fibroin polymerization. The aim of our research was to relate repeat composition to insect biology and fiber strength. Representative regions of the H-fibroin genes were sequenced and analyzed in three pyralid species: wax moth (Galleria mellonella), European flour moth (Ephestia kuehniella), and Indian meal moth (Plodia interpunctella). The amino acid repeats are species-specific, evidently a diversification of an ancestral region of 43 residues, and include three types of regularly dispersed motifs: modifications of GSSAASAA sequence, stretches of tripeptides GXZ where X and Z represent bulky residues, and sequences similar to PVIVIEE. No concatenations of GX dipeptide or alanine, which are typical for Bombyx silkworms and Antheraea silk moths, respectively, were found. Despite different repeat structure, the silks of G. mellonella and E. kuehniella exhibit similar tensile strength as the Bombyx and Antheraea silks. We suggest that in these latter two species, variations in the repeat length obstruct repeat alignment, but sufficiently long stretches of iterated residues get superposed to interact. In the pyralid H-fibroins, interactions of the widely separated and diverse motifs depend on the precision of repeat matching; silk is strong in G. mellonella and E. kuehniella, with 2-3 types of long homogeneous repeats, and nearly 10 times weaker in P. interpunctella, with seven types of shorter erratic repeats. The high proportion of large amino acids in the H-fibroin of pyralids has probably evolved in connection with the spinning habit of caterpillars that live in protective silk tubes and spin continuously, enlarging the tubes on one end and partly devouring the other one. The silk serves as a depot of energetically rich and essential amino acids that may be scarce in the diet.

Fractal 1/f Dynamics Suggest Entanglement of Measurement and Human Performance

ERIC Educational Resources Information Center

Holden, John G.; Choi, Inhyun; Amazeen, Polemnia G.; Van Orden, Guy

2011-01-01

Variability of repeated measurements in human performances exhibits fractal 1/f noise. Yet the relative strength of this fractal pattern varies widely across conditions, tasks, and individuals. Four experiments illustrate how subtle details of the conditions of measurement change the fractal patterns observed across task conditions. The results…

Structure of thrombospondin type 3 repeats in bacterial outer membrane protein A reveals its intra-repeat disulfide bond-dependent calcium-binding capability

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

Dai, Shuyan; Sun, Cancan; Tan, Kemin

Eukaryotic thrombospondin type 3 repeat (TT3R) is an efficient calcium ion (Ca2+) binding motif only found in mammalian thrombospondin family. TT3R has also been found in prokaryotic cellulase Cel5G, which was thought to forfeit the Ca2+-binding capability due to the formation of intra-repeat disulfide bonds, instead of the inter-repeat ones possessed by eukaryotic TT3Rs. In this study, we have identified an enormous number of prokaryotic TT3R-containing proteins belonging to several different protein families, including outer membrane protein A (OmpA), an important structural protein connecting the outer membrane and the periplasmic peptidoglycan layer in gram-negative bacteria. Here, we report the crystalmore » structure of the periplasmic region of OmpA from Capnocytophaga gingivalis, which contains a linker region comprising five consecutive TT3Rs. The structure of OmpA-TT3R exhibits a well-ordered architecture organized around two tightly-coordinated Ca2+ and confirms the presence of abnormal intra-repeat disulfide bonds. Further mutagenesis studies showed that the Ca2+-binding capability of OmpA-TT3R is indeed dependent on the proper formation of intra-repeat disulfide bonds, which help to fix a conserved glycine residue at its proper position for Ca2+ coordination. Additionally, despite lacking inter repeat disulfide bonds, the interfaces between adjacent OmpA-TT3Rs are enhanced by both hydrophobic and conserved aromatic-proline interactions.« less

Optimisation of a sample preparation procedure for the screening of fungal infection and assessment of deoxynivalenol content in maize using mid-infrared attenuated total reflection spectroscopy.

PubMed

Kos, Gregor; Lohninger, Hans; Mizaikoff, Boris; Krska, Rudolf

2007-07-01

A sample preparation procedure for the determination of deoxynivalenol (DON) using attenuated total reflection mid-infrared spectroscopy is presented. Repeatable spectra were obtained from samples featuring a narrow particle size distribution. Samples were ground with a centrifugal mill and analysed with an analytical sieve shaker. Particle sizes of <100, 100-250, 250-500, 500-710 and 710-1000 microm were obtained. Repeatability, classification and quantification abilities for DON were compared with non-sieved samples. The 100-250 microm fraction showed the best repeatability. The relative standard deviation of spectral measurements improved from 20 to 4.4% and 100% of sieved samples were correctly classified compared with 79% of non-sieved samples. The DON level in analysed fractions was a good estimate of overall toxin content.

Automated computation of femoral angles in dogs from three-dimensional computed tomography reconstructions: Comparison with manual techniques.

PubMed

Longo, F; Nicetto, T; Banzato, T; Savio, G; Drigo, M; Meneghello, R; Concheri, G; Isola, M

2018-02-01

The aim of this ex vivo study was to test a novel three-dimensional (3D) automated computer-aided design (CAD) method (aCAD) for the computation of femoral angles in dogs from 3D reconstructions of computed tomography (CT) images. The repeatability and reproducibility of three manual radiography, manual CT reconstructions and the aCAD method for the measurement of three femoral angles were evaluated: (1) anatomical lateral distal femoral angle (aLDFA); (2) femoral neck angle (FNA); and (3) femoral torsion angle (FTA). Femoral angles of 22 femurs obtained from 16 cadavers were measured by three blinded observers. Measurements were repeated three times by each observer for each diagnostic technique. Femoral angle measurements were analysed using a mixed effects linear model for repeated measures to determine the levels of intra-observer agreement (repeatability) and inter-observer agreement (reproducibility). Repeatability and reproducibility of measurements using the aCAD method were excellent (intra-class coefficients, ICCs≥0.98) for all three angles assessed. Manual radiography and CT exhibited excellent agreement for the aLDFA measurement (ICCs≥0.90). However, FNA repeatability and reproducibility were poor (ICCs<0.8), whereas FTA measurement showed slightly higher ICCs values, except for the radiographic reproducibility, which was poor (ICCs<0.8). The computation of the 3D aCAD method provided the highest repeatability and reproducibility among the tested methodologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

The 2.1-kb inverted repeat DNA sequences flank the mat2,3 silent region in two species of Schizosaccharomyces and are involved in epigenetic silencing in Schizosaccharomyces pombe.

PubMed Central

Singh, Gurjeet; Klar, Amar J S

2002-01-01

The mat2,3 region of the fission yeast Schizosaccharomyces pombe exhibits a phenomenon of transcriptional silencing. This region is flanked by two identical DNA sequence elements, 2.1 kb in length, present in inverted orientation: IRL on the left and IRR on the right of the silent region. The repeats do not encode any ORF. The inverted repeat DNA region is also present in a newly identified related species, which we named S. kambucha. Interestingly, the left and right repeats share perfect identity within a species, but show approximately 2% bases interspecies variation. Deletion of IRL results in variegated expression of markers inserted in the silent region, while deletion of the IRR causes their derepression. When deletions of these repeats were genetically combined with mutations in different trans-acting genes previously shown to cause a partial defect in silencing, only mutations in clr1 and clr3 showed additive defects in silencing with the deletion of IRL. The rate of mat1 switching is also affected by deletion of repeats. The IRL or IRR deletion did not cause significant derepression of the mat2 or mat3 loci. These results implicate repeats for maintaining full repression of the mat2,3 region, for efficient mat1 switching, and further support the notion that multiple pathways cooperate to silence the mat2,3 domain. PMID:12399374

Genetic Susceptibility for Individual Cooperation Preferences: The Role of Monoamine Oxidase A Gene (MAOA) in the Voluntary Provision of Public Goods

PubMed Central

Mertins, Vanessa; Schote, Andrea B.; Hoffeld, Wolfgang; Griessmair, Michele; Meyer, Jobst

2011-01-01

In the context of social dilemmas, previous research has shown that human cooperation is mainly based on the social norm of conditional cooperation. While in most cases individuals behave according to such a norm, deviant behavior is no exception. Recent research further suggests that heterogeneity in social behavior might be associated with varying genetic predispositions. In this study, we investigated the relationship between individuals' behavior in a public goods experiment and the promoter-region functional repeat polymorphism in the monoamine oxidase A gene (MAOA). In a dynamic setting of increasing information about others' contributions, we analyzed differences in two main components of conditional cooperation, namely the players' own contribution and their beliefs regarding the contribution of other players. We showed that there is a significant association between individuals' behavior in a repeated public goods game and MAOA. Our results suggest that male carriers of the low activity alleles cooperate significantly less than those carrying the high activity alleles given a situation where subjects had to rely on their innate beliefs about others' contributions. With increasing information about the others' cooperativeness, the genetic effect diminishes. Furthermore, significant opposing effects for female subjects carrying two low activity alleles were observed. PMID:21698196

Validation of the King's Sarcoidosis Questionnaire (KSQ) in a Dutch sarcoidosis population.

PubMed

Van Manen, Mirjam J G; Wapenaar, Monique; Strookappe, Bert; Drent, Marjolein; Elfferich, Marjon; de Vries, Jolanda; Gosker, Harry R; Birring, Surinder S; Patel, Amit S; van den Toorn, Leon; van den Blink, Bernt; Boomars, Karin; Hoitsma, Elske; Wijsenbeek, Marlies S

2016-03-29

The King's Sarcoidosis Questionnaire (KSQ) is a brief questionnaire assessing health status using five modules (General Health Status, Lung, Eyes, Skin, Medication) in patients with sarcoidosis. The KSQ was only validated in one English sarcoidosis cohort. The aim of this study was to validate the KSQ in a Dutch sarcoidosis population. The KSQ was translated according to international guidelines and tested in interviews with patients. Consecutive outpatients completed multiple questionnaires twice, two weeks apart. Construct validity, internal consistency and repeatability were determined. Of the 98 patients included 85 had lung, 22 skin and 24 eye disease. There was good construct validity of the KSQ General Health Status module against the World Health Organization Quality of Life-BREF questionnaire. The Medication module correlated weak to moderate with most questionnaires. The correlations with organ-specific questionnaires varied from strong for Eyes (r=0.75), Skin (r=-0.62) to moderate for Lung (r=-0.45 with MRC breathlessness scale). Internal consistency was good for all KSQ modules (Cronbach's α 0.72-0.93). Intraclass correlation coefficients (0.70-0.90) and Bland-Altman plots showed good repeatability of the KSQ. The Dutch KSQ is the first translation of the English KSQ, validated in a Dutch sarcoidosis population.

[Stability of whole cell biocatalyst for biodiesel production from renewable oils].

PubMed

Sun, Ting; Du, Wei; Liu, Dehua; Li, Wei; Zeng, Jing; Dai, Lingmei

2009-09-01

Lipase-mediated biodiesel production becomes increasingly important because of mild reaction conditions, pollution free during the process and easy product separation. Compared with traditional immobilized lipase, whole cell biocatalyst is promising for biodiesel production because it is easy to prepare and has higher enzyme activity recovery. Rhizopus oryzae IFO4697 can be used as the catalyst for biodiesel production. To further study the stability of the whole cell biocatalyst is extremely important for its further application on large scale. This paper focuses on the stability study of Rhizopus oryzae IFO4697 when used for the methanolysis of renewable oils for biodiesel production. The results showed that water content was important for achieving high catalytic activity and good stability of the biocatalyst. The optimum water content was found to be 5%-15%. Both particle size and desiccation methods showed no obvious effect on the stability of the biocatalyst. With GA cross-linking pretreatment, the stability of the biocatalyst could be improved significantly. When Rhizopus oryzae IFO4697 repeatedly used for next batch reaction, direct vacuum filtration was found to be a good way for the maintenance of good stability of the biocatalyst. Under the optimum reaction conditions, the methyl ester yield could keep over 80% during 20 repeated reaction batches.

If Empowerment Is So Good, Why Does It Hurt?

ERIC Educational Resources Information Center

Holpp, Lawrence

1995-01-01

The following suggestions can make employee empowerment work: (1) do the basics first; (2) learn to do things flawlessly; (3) add new tasks only as old ones are mastered; (4) make new tasks work as flawlessly as the basics; and (5) repeat, ad infinitum. (Author/JOW)

Nudge for (the Public) Good: How Defaults Can Affect Cooperation

PubMed Central

Fosgaard, Toke R.; Piovesan, Marco

2015-01-01

In this paper we test the effect of non-binding defaults on the level of contribution to a public good. We manipulate the default numbers appearing on the decision screen to nudge subjects toward a free-rider strategy or a perfect conditional cooperator strategy. Our results show that the vast majority of our subjects did not adopt the default numbers, but their stated strategy was affected by the default. Moreover, we find that our manipulation spilled over to a subsequent repeated public goods game where default was not manipulated. Here we found that subjects who previously saw the free rider default were significantly less cooperative than those who saw the perfect conditional cooperator default. PMID:26717569

Nudge for (the Public) Good: How Defaults Can Affect Cooperation.

PubMed

Fosgaard, Toke R; Piovesan, Marco

2015-01-01

In this paper we test the effect of non-binding defaults on the level of contribution to a public good. We manipulate the default numbers appearing on the decision screen to nudge subjects toward a free-rider strategy or a perfect conditional cooperator strategy. Our results show that the vast majority of our subjects did not adopt the default numbers, but their stated strategy was affected by the default. Moreover, we find that our manipulation spilled over to a subsequent repeated public goods game where default was not manipulated. Here we found that subjects who previously saw the free rider default were significantly less cooperative than those who saw the perfect conditional cooperator default.

Repeatability of short-duration transient visual evoked potentials in normal subjects.

PubMed

Tello, Celso; De Moraes, Carlos Gustavo V; Prata, Tiago S; Derr, Peter; Patel, Jayson; Siegfried, John; Liebmann, Jeffrey M; Ritch, Robert

2010-06-01

To evaluate the within-session and inter-session repeatability of a new, short-duration transient visual evoked potential (SD-tVEP) device on normal individuals, we tested 30 normal subjects (20/20 visual acuity, normal 24-2 SITA Standard VF) with SD-tVEP. Ten of these subjects had their tests repeated within 1-2 months from the initial visit. Synchronized single-channel EEG was recorded using a modified Diopsys Enfant System (Diopsys, Inc., Pine Brook, New Jersey, USA). A checkerboard stimulus was modulated at two reversals per second. Two different contrasts of checkerboard reversal patterns were used: 85% Michelson contrast with a mean luminance of 66.25 cd/m(2) and 10% Michelson contrast with a mean luminance of 112 cd/m(2). Each test lasted 20 s. Both eyes, independently and together, were tested 10 times (5 times at each contrast level). The following information was identified from the filtered N75-P100-N135 complex: N75 amplitude, N75 latency, P100 amplitude, P100 latency, and Delta Amplitude (N75-P100). The median values for each eye's five SD-tVEP parameters were calculated and grouped into two data sets based on contrast level. Mean age was 27.3 +/- 5.2 years. For OD only, the median (95% confidence intervals) of Delta Amplitude (N75-P100) amplitudes at 10% and 85% contrast were 4.6 uV (4.1-5.9) and 7.1 uV (5.15-9.31). The median P100 latencies were 115.2 ms (112.0-117.7) and 104.0 ms (99.9-106.0). There was little within-session variability for any of these parameters. Intraclass correlation coefficients ranged between 0.64 and 0.98, and within subject coefficients of variation were 3-5% (P100 latency) and 15-30% (Delta Amplitude (N75-P100) amplitude). Bland-Altman plots showed good agreement between the first and fifth test sessions (85% contrast Delta Amplitude (N75-P100) delta amplitude, mean difference, 0.48 mV, 95% CI, -0.18-1.12; 85% contrast P100 latency delay, -0.82 ms, 95% CI, -3.12-1.46; 10% contrast Delta Amplitude (N75-P100) amplitude, 0.58 mV, 95% CI, -0.27-1.45; 10% contrast P100 latency delay, -2.05 mV, 95% CI, -5.12-1.01). The inter-eye correlation and agreement were significant for both SD-tVEP amplitude and P100 latency measurements. For the subset of eyes in which the inter-session repeatability was tested, the intraclass correlation coefficients ranged between 0.71 and 0.86 with good agreement shown on Bland-Altman plots. Short-duration transient VEP technology showed good within-session, inter-session repeatability, and good inter-eye correlation and agreement.

Sonoelastographic Features of the Patellar Ligament in Clinically Normal Dogs.

PubMed

Piccionello, Angela P; Serrani, Daniele; Busoni, Valeria; Salvaggio, Alberto; Bonazzi, Mattia; Bergamino, Chiara; Volta, Antonella

2018-06-11

 This article describes the sonoelastographic features of the patellar ligament of sound dogs and tests feasibility, reproducibility and repeatability.  Clinically healthy medium-to-large breed dogs were enrolled. Sonoelastographic images of the patellar ligaments were obtained in lateral recumbency with the stifle flexed by an experienced operator and by a senior veterinary student. The elasticity colour map included red (soft), green (intermediate) and blue (hard). Tissue elasticity was measured by calculating the percentage of softness with dedicated software. Categorical, qualitative data analysis was performed using a weighted kappa statistic for repeatability and reproducibility. A categorical qualitative assessment was performed based on a grading scale of 1 to 5 (soft, mostly soft, intermediate, mostly hard and hard).  Fourteen clinically normal dogs were considered. A total of 28 patellar ligaments were examined. Overall, 25 of the patellar ligaments were graded as soft or mostly soft and the remaining 3 as intermediate. Repeatability was 86.2%, with a weighted kappa of 0.64 (good), for the well-trained sonographer and 83.3%, with a weighted kappa of 0.53 (moderate), for the senior student. Reproducibility was 86.2%, with a weighed kappa of 0.65 (good).  Sonoelastography of the canine patellar ligament is a feasible and reproducible technique. Patellar ligaments in clinically normal dogs showed highly elastic biomechanical properties. Schattauer GmbH Stuttgart.

Comparison of three-dimensional optical coherence tomography and combining a rotating Scheimpflug camera with a Placido topography system for forme fruste keratoconus diagnosis.

PubMed

Fukuda, Shinichi; Beheregaray, Simone; Hoshi, Sujin; Yamanari, Masahiro; Lim, Yiheng; Hiraoka, Takahiro; Yasuno, Yoshiaki; Oshika, Tetsuro

2013-12-01

To evaluate the ability of parameters measured by three-dimensional (3D) corneal and anterior segment optical coherence tomography (CAS-OCT) and a rotating Scheimpflug camera combined with a Placido topography system (Scheimpflug camera with topography) to discriminate between normal eyes and forme fruste keratoconus. Forty-eight eyes of 48 patients with keratoconus, 25 eyes of 25 patients with forme fruste keratoconus and 128 eyes of 128 normal subjects were evaluated. Anterior and posterior keratometric parameters (steep K, flat K, average K), elevation, topographic parameters, regular and irregular astigmatism (spherical, asymmetry, regular and higher-order astigmatism) and five pachymetric parameters (minimum, minimum-median, inferior-superior, inferotemporal-superonasal, vertical thinnest location of the cornea) were measured using 3D CAS-OCT and a Scheimpflug camera with topography. The area under the receiver operating curve (AUROC) was calculated to assess the discrimination ability. Compatibility and repeatability of both devices were evaluated. Posterior surface elevation showed higher AUROC values in discrimination analysis of forme fruste keratoconus using both devices. Both instruments showed significant linear correlations (p<0.05, Pearson's correlation coefficient) and good repeatability (ICCs: 0.885-0.999) for normal and forme fruste keratoconus. Posterior elevation was the best discrimination parameter for forme fruste keratoconus. Both instruments presented good correlation and repeatability for this condition.

Evaluation of the Nova StatSensor® XpressTM Creatinine Point-Of-Care Handheld Analyzer

PubMed Central

Kosack, Cara Simone; de Kieviet, Wim; Bayrak, Kubra; Milovic, Anastacija; Page, Anne Laure

2015-01-01

Creatinine is a parameter that is required to monitor renal function and is important to follow in patients under treatment with potentially toxic renal drugs, such as the anti-HIV drug Tenofovir. A point of care instrument to measure creatinine would be useful for patients monitoring in resource-limited settings, where more instruments that are sophisticated are not available. The StatSensor Xpress Creatinine (Nova Biomedical Cooperation, Waltham, MA, USA) point of care analyzer was evaluated for its diagnostic performance in indicating drug therapy change. Creatinine was measured in parallel using the Nova StatSensor Xpress Creatinine analyzer and the Vitros 5,1FS (Ortho Clinical Diagnostics, Inc, Rochester, USA), which served as reference standard. The precision (i.e., repeatability and reproducibility) and accuracy of the StatSensor Xpress Creatinine analyzer were calculated using a panel of specimens with normal, low pathological and high pathological values. Two different Nova StatSensor Xpress Creatinine analyzers were used for the assessment of accuracy using repeated measurements. The coefficient of variation of the StatSensor Xpress Creatinine analyzers ranged from 2.3 to 5.9% for repeatability and from 4.2 to 9.0% for between-run reproducibility. The concordance correlation agreement was good except for high values (>600 µmol/L). The Bland-Altman analysis in high pathological specimens suggests that the Nova StatSensor Xpress Creatinine test tends to underestimate high creatinine values (i.e., >600 µmol/L). The Nova StatSensor Xpress Creatinine analyzers showed acceptable to good results in terms of repeatability, inter-device reproducibility and between-run reproducibility over time using quality control reagents. The analyzer was found sufficiently accurate for detecting pathological values in patients (age >10 year) and can be used with a moderate risk of misclassification. PMID:25886375

Evaluation of the Nova StatSensor® Xpress(TM) Creatinine point-of-care handheld analyzer.

PubMed

Kosack, Cara Simone; de Kieviet, Wim; Bayrak, Kubra; Milovic, Anastacija; Page, Anne Laure

2015-01-01

Creatinine is a parameter that is required to monitor renal function and is important to follow in patients under treatment with potentially toxic renal drugs, such as the anti-HIV drug Tenofovir. A point of care instrument to measure creatinine would be useful for patients monitoring in resource-limited settings, where more instruments that are sophisticated are not available. The StatSensor Xpress Creatinine (Nova Biomedical Cooperation, Waltham, MA, USA) point of care analyzer was evaluated for its diagnostic performance in indicating drug therapy change. Creatinine was measured in parallel using the Nova StatSensor Xpress Creatinine analyzer and the Vitros 5,1FS (Ortho Clinical Diagnostics, Inc, Rochester, USA), which served as reference standard. The precision (i.e., repeatability and reproducibility) and accuracy of the StatSensor Xpress Creatinine analyzer were calculated using a panel of specimens with normal, low pathological and high pathological values. Two different Nova StatSensor Xpress Creatinine analyzers were used for the assessment of accuracy using repeated measurements. The coefficient of variation of the StatSensor Xpress Creatinine analyzers ranged from 2.3 to 5.9% for repeatability and from 4.2 to 9.0% for between-run reproducibility. The concordance correlation agreement was good except for high values (>600 µmol/L). The Bland-Altman analysis in high pathological specimens suggests that the Nova StatSensor Xpress Creatinine test tends to underestimate high creatinine values (i.e., >600 µmol/L). The Nova StatSensor Xpress Creatinine analyzers showed acceptable to good results in terms of repeatability, inter-device reproducibility and between-run reproducibility over time using quality control reagents. The analyzer was found sufficiently accurate for detecting pathological values in patients (age >10 year) and can be used with a moderate risk of misclassification.

One and done? Equality of opportunity and repeated access to scarce, indivisible medical resources

PubMed Central

2012-01-01

Background Existing ethical guidelines recommend that, all else equal, past receipt of a medical resource (e.g. a scarce organ) should not be considered in current allocation decisions (e.g. a repeat transplantation). Discussion One stated reason for this ethical consensus is that formal theories of ethics and justice do not persuasively accept or reject repeated access to the same medical resources. Another is that restricting attention to past receipt of a particular medical resource seems arbitrary: why couldn’t one just as well, it is argued, consider receipt of other goods such as income or education? In consequence, simple allocation by lottery or first-come-first-served without consideration of any past receipt is thought to best afford equal opportunity, conditional on equal medical need. There are three issues with this view that need to be addressed. First, public views and patient preferences are less ambiguous than formal theories of ethics. Empirical work shows strong preferences for fairness in health care that have not been taken into account: repeated access to resources has been perceived as unfair. Second, while difficult to consider receipt of many other prior resources including non-medical resources, this should not be used a motive for ignoring the receipt of any and all goods including the focal resource in question. Third, when all claimants to a scarce resource are equally deserving, then use of random allocation seems warranted. However, the converse is not true: mere use of a randomizer does not by itself make the merits of all claimants equal. Summary My conclusion is that not ignoring prior receipt of the same medical resource, and prioritizing those who have not previously had access to the medical resource in question, may be perceived as fairer and more equitable by society. PMID:22624597

Reference values for respiratory rate in the first 3 years of life.

PubMed

Rusconi, F; Castagneto, M; Gagliardi, L; Leo, G; Pellegatta, A; Porta, N; Razon, S; Braga, M

1994-09-01

Raised respiratory rate is a useful sign to diagnose lower respiratory infections in childhood. However, the normal range for respiratory rate has not been defined in a proper, large sample. To assess the respiratory rate in a large number of infants and young children in order to construct percentile curves by age; to determine the repeatability to the assessment using a stethoscope and compare it with observation. Respiratory rate was recorded for 1 minute with a stethoscope in 618 infants and children, aged 15 days to 3 years old, without respiratory infections or any other severe disease when awake and calm and when asleep. In 50 subjects we compared respiratory rate taken 30 to 60 minutes apart to assess repeatability, and in 50 others we compared simultaneous counts obtained by stethoscope versus observation. Repeatability was good as the standard deviation of differences was 2.5 breaths/minute in awake and 1.7 breaths/minute in asleep children. Respiratory rate obtained with a stethoscope was systematically higher than that obtained by observation (mean difference 2.6 breaths/minute in awake and 1.8 breaths/minute in asleep children; P = .015 and P < .001, respectively). A decrease in respiratory rate with age was seen for both states, and it was faster in the first few months of life when also a greater dispersion of values was observed. A second degree polynomial curve accurately fitted the data. Reference percentile values were developed from these data. The repeatability of respiratory rate measured with a stethoscope was good. Percentile curves would be particularly helpful in the first months of life when the decline in respiratory rate is very rapid and prevents to use cut off values for defining "normality."

One and done? Equality of opportunity and repeated access to scarce, indivisible medical resources.

PubMed

Huesch, Marco D

2012-05-24

Existing ethical guidelines recommend that, all else equal, past receipt of a medical resource (e.g. a scarce organ) should not be considered in current allocation decisions (e.g. a repeat transplantation). One stated reason for this ethical consensus is that formal theories of ethics and justice do not persuasively accept or reject repeated access to the same medical resources. Another is that restricting attention to past receipt of a particular medical resource seems arbitrary: why couldn't one just as well, it is argued, consider receipt of other goods such as income or education? In consequence, simple allocation by lottery or first-come-first-served without consideration of any past receipt is thought to best afford equal opportunity, conditional on equal medical need.There are three issues with this view that need to be addressed. First, public views and patient preferences are less ambiguous than formal theories of ethics. Empirical work shows strong preferences for fairness in health care that have not been taken into account: repeated access to resources has been perceived as unfair. Second, while difficult to consider receipt of many other prior resources including non-medical resources, this should not be used a motive for ignoring the receipt of any and all goods including the focal resource in question. Third, when all claimants to a scarce resource are equally deserving, then use of random allocation seems warranted. However, the converse is not true: mere use of a randomizer does not by itself make the merits of all claimants equal. My conclusion is that not ignoring prior receipt of the same medical resource, and prioritizing those who have not previously had access to the medical resource in question, may be perceived as fairer and more equitable by society.

Tuboimpedance: A New Test of Eustachian Tube Function.

PubMed

Smith, Matthew E; Zou, Charlie C; Blythe, Andrew J C; Tysome, James R

2017-04-01

Objective Eustachian tube (ET) dysfunction is most frequently caused by a failure of the ET to adequately open; however, there is currently no reliable method of assessing this. Tubomanometry has recently shown good interindividual repeatability as a measure of ET function by measuring middle ear pressure after the application of regulated nasopharyngeal pressures during swallowing. We present the first reports of a novel test: middle ear impedance measurements during standard nasopharyngeal pressure application (tuboimpedance). We assess repeatability in healthy ears and any advantages over tubomanometry. Study Design Exploratory cohort diagnosis study. Setting Tertiary referral center. Subjects Twenty screened, healthy ears (10 volunteers). Methods Tubomanometry and tuboimpedance tests were performed while individuals swallowed with applied nasopharyngeal pressures of 20, 30, 40, and 50 mbar. Eustachian tube opening detection rate and test repeatability (measured by intraclass correlation coefficient [ICC]) for immediate and delayed repeats at each pressure were compared. Results ET opening was detected more frequently using tuboimpedance, with a 100% detection rate using a nasopharyngeal pressure of 30 mbar or more, compared to 88% to 96% with tubomanometry. Detection of ET opening at 20 mbar was possible with tuboimpedance. Repeatability of both tests was mostly strong (ICC >0.7) for both immediate and delayed repeats. Repeatability for the tubomanometry R value was only fair to moderate. Conclusion Tuboimpedance may provide a repeatable measure of ET opening that is easier to perform due to lower nasopharyngeal pressures required and fewer issues with poor ear-probe sealing. Further assessment in patients with different forms of ET dysfunction is required.

Competing Cues: Older Adults Rely on Knowledge in the Face of Fluency

PubMed Central

Brashier, Nadia M.; Umanath, Sharda; Cabeza, Roberto; Marsh, Elizabeth J.

2017-01-01

Consumers regularly encounter repeated false claims in political and marketing campaigns, but very little empirical work addresses their impact among older adults. Repeated statements feel easier to process, and thus more truthful, than new ones (i.e., illusory truth). When judging truth, older adults’ accumulated general knowledge may offset this perception of fluency. In two experiments, participants read statements that contradicted information stored in memory; a post-experimental knowledge check confirmed what individual participants knew. Unlike young adults, older adults exhibited illusory truth only when they lacked knowledge about claims. This interaction between knowledge and fluency extends dual-process theories of aging. PMID:28333505

The Value of Educators "On the Floor": Comparing Three Modes of Presenting Science on a Sphere®

ERIC Educational Resources Information Center

Hayward, Jeff; Hart, Jolene K.

2015-01-01

Exhibit experiences at most museums are designed to be self-guided rather than facilitated; and it's certainly a good goal to make exhibit interpretation clear enough to be understood on one's own. The primary rationale for not staffing exhibits is the ongoing personnel cost, but that should be weighed against the value of "on the floor"…

Validity and reliability of short forms of parental-caregiver perception and family impact scale in a Telugu speaking population of India.

PubMed

Kumar, Santhosh; Kroon, Jeroen; Lalloo, Ratilal; Johnson, Newell W

2016-03-01

Parental-Caregiver Perception Questionnaire (P-CPQ) and Family Impact Scale (FIS) are commonly used measures to evaluate the parent's perception of the impact of children's oral health on quality of life and family respectively. Recently, shorter forms of P-CPQ and FIS have been developed. No study has sought to validate these short forms in other languages and cultures. This study aimed to evaluate the validity and reliability of FIS, 8 and 16-item P-CPQ in a Telugu speaking population of India. For this cross-sectional study, a multi-stage random sampling technique was used to recruit 11-13 year-old schoolchildren of Medak district, Telangana, India and their parents (n = 1342). Parents were approached with questionnaires through their children who underwent clinical examinations for dental caries, fluorosis and malocclusion. The translated versions underwent pilot testing (n = 40), test-retest reliability was also assessed (n = 161). The overall summary scale and subscales of the short forms of P-CPQ and FIS failed to discriminate between the categories of dental caries severity. Also, malocclusion status was not related to the domain or overall scores of both the short forms of P-CPQ. There were significant differences in subscale and overall scores of 16 and 8-item P-CPQ and FIS between the fluorosis categories. Both 16 and 8-item P-CPQ summary scales were significantly related to parent's global rating of oral health (16-item, r = 0.30, p < 0.01; 8-item, r = 0.28, p < 0.01) and overall wellbeing (16-item, r = 0.22, p < 0.01; 8-item, r = 0.22, p < 0.01), thereby exhibiting good construct validity. However, the correlation of emotional and social wellbeing scales of short forms of P-CPQ and FIS with global ratings was of low strength. Cronbach's alphas for FIS, 16-items and 8-items P-CPQ scales were 0.78, 0.83 and 0.71 respectively, while the Intra-Class Correlation coefficients were 0.752, 0.812 and 0.816 respectively. Cronbach's alphas for most of the subscales of short forms of P-CPQ were less than 0.7. The overall scales of 16 and 8-items P-CPQ scales demonstrated good construct validity while the construct validity of FIS was questionable. Discriminant validity of all the three instruments was good only in relation to fluorosis. Overall scales of all three short forms exhibited acceptable internal consistency and reliability on repeated administrations.

DXS10011: studies on structure, allele distribution in three populations and genetic linkage to further q-telomeric chromosome X markers.

PubMed

Hering, Sandra; Brundirs, Nicola; Kuhlisch, Eberhard; Edelmann, Jeanett; Plate, Ines; Benecke, Mark; Van, Pham Hung; Michael, Matthias; Szibor, Reinhard

2004-12-01

The hypervariable tetranucleotide STR polymorphism DXS10011 is a powerful marker for forensic purposes. Investigation of this STR led to an allele nomenclature which is in consensus with the ISFG recommendations. DXS10011 is located at Xq28 and genetically closely linked to DXS7423 and DXS8377 but is unlinked to HPRTB and more distant X-chromosomal STRs. DXS10011 is a very complex marker exhibiting some structural variants within alleles of identical length. Two types of repeat structure (regular and inter-alleles) are known and described as types A and B. Two SNPs which are in strong linkage disequilibrium to the different sequence types were found in the repeat flanking region. The type A sequence consists of a long stretch of uninterrupted homogenous repeats which is highly susceptible to slippage mutation during male meiosis.

Validity and repeatability of inertial measurement units for measuring gait parameters.

PubMed

Washabaugh, Edward P; Kalyanaraman, Tarun; Adamczyk, Peter G; Claflin, Edward S; Krishnan, Chandramouli

2017-06-01

Inertial measurement units (IMUs) are small wearable sensors that have tremendous potential to be applied to clinical gait analysis. They allow objective evaluation of gait and movement disorders outside the clinic and research laboratory, and permit evaluation on large numbers of steps. However, repeatability and validity data of these systems are sparse for gait metrics. The purpose of this study was to determine the validity and between-day repeatability of spatiotemporal metrics (gait speed, stance percent, swing percent, gait cycle time, stride length, cadence, and step duration) as measured with the APDM Opal IMUs and Mobility Lab system. We collected data on 39 healthy subjects. Subjects were tested over two days while walking on a standard treadmill, split-belt treadmill, or overground, with IMUs placed in two locations: both feet and both ankles. The spatiotemporal measurements taken with the IMU system were validated against data from an instrumented treadmill, or using standard clinical procedures. Repeatability and minimally detectable change (MDC) of the system was calculated between days. IMUs displayed high to moderate validity when measuring most of the gait metrics tested. Additionally, these measurements appear to be repeatable when used on the treadmill and overground. The foot configuration of the IMUs appeared to better measure gait parameters; however, both the foot and ankle configurations demonstrated good repeatability. In conclusion, the IMU system in this study appears to be both accurate and repeatable for measuring spatiotemporal gait parameters in healthy young adults. Copyright © 2017 Elsevier B.V. All rights reserved.

Medium-sized tandem repeats represent an abundant component of the Drosophila virilis genome.

PubMed

Abdurashitov, Murat A; Gonchar, Danila A; Chernukhin, Valery A; Tomilov, Victor N; Tomilova, Julia E; Schostak, Natalia G; Zatsepina, Olga G; Zelentsova, Elena S; Evgen'ev, Michael B; Degtyarev, Sergey K H

2013-11-09

Previously, we developed a simple method for carrying out a restriction enzyme analysis of eukaryotic DNA in silico, based on the known DNA sequences of the genomes. This method allows the user to calculate lengths of all DNA fragments that are formed after a whole genome is digested at the theoretical recognition sites of a given restriction enzyme. A comparison of the observed peaks in distribution diagrams with the results from DNA cleavage using several restriction enzymes performed in vitro have shown good correspondence between the theoretical and experimental data in several cases. Here, we applied this approach to the annotated genome of Drosophila virilis which is extremely rich in various repeats. Here we explored the combined approach to perform the restriction analysis of D. virilis DNA. This approach enabled to reveal three abundant medium-sized tandem repeats within the D. virilis genome. While the 225 bp repeats were revealed previously in intergenic non-transcribed spacers between ribosomal genes of D. virilis, two other families comprised of 154 bp and 172 bp repeats were not described. Tandem Repeats Finder search demonstrated that 154 bp and 172 bp units are organized in multiple clusters in the genome of D. virilis. Characteristically, only 154 bp repeats derived from Helitron transposon are transcribed. Using in silico digestion in combination with conventional restriction analysis and sequencing of repeated DNA fragments enabled us to isolate and characterize three highly abundant families of medium-sized repeats present in the D. virilis genome. These repeats comprise a significant portion of the genome and may have important roles in genome function and structural integrity. Therefore, we demonstrated an approach which makes possible to investigate in detail the gross arrangement and expression of medium-sized repeats basing on sequencing data even in the case of incompletely assembled and/or annotated genomes.

Preparation and Characterization of Biomass-Derived Advanced Carbon Materials for Lithium-Ion Battery Applications

NASA Astrophysics Data System (ADS)

Hardiansyah, Andri; Chaldun, Elsy Rahimi; Nuryadin, Bebeh Wahid; Fikriyyah, Anti Khoerul; Subhan, Achmad; Ghozali, Muhammad; Purwasasmita, Bambang Sunendar

2018-04-01

In this study, carbon-based advanced materials for lithium-ion battery applications were prepared by using soybean waste-based biomass material, through a straightforward process of heat treatment followed by chemical modification processes. Various types of carbon-based advanced materials were developed. Physicochemical characteristics and electrochemical performance of the resultant materials were characterized systematically. Scanning electron microscopy observation revealed that the activated carbon and graphene exhibits wrinkles structures and porous morphology. Electrochemical impedance spectroscopy (EIS) revealed that both activated carbon and graphene-based material exhibited a good conductivity. For instance, the graphene-based material exhibited equivalent series resistance value of 25.9 Ω as measured by EIS. The graphene-based material also exhibited good reversibility and cyclic performance. Eventually, it would be anticipated that the utilization of soybean waste-based biomass material, which is conforming to the principles of green materials, could revolutionize the development of advanced material for high-performance energy storage applications, especially for lithium-ion batteries application.

Preparation and Characterization of Biomass-Derived Advanced Carbon Materials for Lithium-Ion Battery Applications

NASA Astrophysics Data System (ADS)

Hardiansyah, Andri; Chaldun, Elsy Rahimi; Nuryadin, Bebeh Wahid; Fikriyyah, Anti Khoerul; Subhan, Achmad; Ghozali, Muhammad; Purwasasmita, Bambang Sunendar

2018-07-01

In this study, carbon-based advanced materials for lithium-ion battery applications were prepared by using soybean waste-based biomass material, through a straightforward process of heat treatment followed by chemical modification processes. Various types of carbon-based advanced materials were developed. Physicochemical characteristics and electrochemical performance of the resultant materials were characterized systematically. Scanning electron microscopy observation revealed that the activated carbon and graphene exhibits wrinkles structures and porous morphology. Electrochemical impedance spectroscopy (EIS) revealed that both activated carbon and graphene-based material exhibited a good conductivity. For instance, the graphene-based material exhibited equivalent series resistance value of 25.9 Ω as measured by EIS. The graphene-based material also exhibited good reversibility and cyclic performance. Eventually, it would be anticipated that the utilization of soybean waste-based biomass material, which is conforming to the principles of green materials, could revolutionize the development of advanced material for high-performance energy storage applications, especially for lithium-ion batteries application.

Prevalence of spinocerebellar ataxia 36 in a US population.

PubMed

Valera, Juliana M; Diaz, Tatyana; Petty, Lauren E; Quintáns, Beatriz; Yáñez, Zuleima; Boerwinkle, Eric; Muzny, Donna; Akhmedov, Dmitry; Berdeaux, Rebecca; Sobrido, Maria J; Gibbs, Richard; Lupski, James R; Geschwind, Daniel H; Perlman, Susan; Below, Jennifer E; Fogel, Brent L

2017-08-01

To assess the prevalence and clinical features of individuals affected by spinocerebellar ataxia 36 (SCA36) at a large tertiary referral center in the United States. A total of 577 patients with undiagnosed sporadic or familial cerebellar ataxia comprehensively evaluated at a tertiary referral ataxia center were molecularly evaluated for SCA36. Repeat primed PCR and fragment analysis were used to screen for the presence of a repeat expansion in the NOP56 gene. Fragment analysis of triplet repeat primed PCR products identified a GGCCTG hexanucleotide repeat expansion in intron 1 of NOP56 in 4 index cases. These 4 SCA36-positive families comprised 2 distinct ethnic groups: white (European) (2) and Asian (Japanese [1] and Vietnamese [1]). Individuals affected by SCA36 exhibited typical clinical features with gait ataxia and age at onset ranging between 35 and 50 years. Patients also suffered from ataxic or spastic limbs, altered reflexes, abnormal ocular movement, and cognitive impairment. In a US population, SCA36 was observed to be a rare disorder, accounting for 0.7% (4/577 index cases) of disease in a large undiagnosed ataxia cohort.

TAL effector-DNA specificity.

PubMed

Scholze, Heidi; Boch, Jens

2010-01-01

TAL effectors are important virulence factors of bacterial plant pathogenic Xanthomonas, which infect a wide variety of plants including valuable crops like pepper, rice, and citrus. TAL proteins are translocated via the bacterial type III secretion system into host cells and induce transcription of plant genes by binding to target gene promoters. Members of the TAL effector family differ mainly in their central domain of tandemly arranged repeats of typically 34 amino acids each with hypervariable di-amino acids at positions 12 and 13. We recently showed that target DNA-recognition specificity of TAL effectors is encoded in a modular and clearly predictable mode. The repeats of TAL effectors feature a surprising one repeat-to-one-bp correlation with different repeat types exhibiting a different DNA base pair specificity. Accordingly, we predicted DNA specificities of TAL effectors and generated artificial TAL proteins with novel DNA recognition specificities. We describe here novel artificial TALs and discuss implications for the DNA recognition specificity. The unique TAL-DNA binding domain allows design of proteins with potentially any given DNA recognition specificity enabling many uses for biotechnology.

78 FR 32356 - United States-Korea Free Trade Agreement

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-30

... possesses the required origin information; (2) the consistent application of the rules of origin to UKFTA... finding of either (a) repeated unlawful activity or (b) willful presentation of inaccurate origin... that a claim of origin for a textile or apparel good is accurate) or Article 4.3.5 (verification to...

47 CFR 25.263 - Information sharing requirements for SDARS terrestrial repeater operators.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SDARS licensee and all potentially affected WCS licensees reach a mutual agreement to provide... SDARS licensee and all potentially affected WCS licensees reach a mutual agreement to provide... notice period. (e) Duty to cooperate. SDARS licensees must cooperate in good faith in the selection and...

Flowtables: Program Skeletal Inversion for Defeat of Interprocedural Analysis with Unique Metamorphism

DTIC Science & Technology

2015-08-28

use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the...Hulin, T. Leek, and R. Whelan. Repeatable reverse engineering for the greater good with panda . Technical report, Columbia University, 2014. https

Repeated holdout Cross-Validation of Model to Estimate Risk of Lyme Disease by Landscape Attributes

EPA Science Inventory

We previously modeled Lyme disease (LD) risk at the landscape scale; here we evaluate the model's overall goodness-of-fit using holdout validation. Landscapes were characterized within road-bounded analysis units (AU). Observed LD cases (obsLD) were ascertained per AU. Data were ...

Comparison of fatigue analysis approaches for hot-mix asphalt to ensure a state of good repair.

DOT National Transportation Integrated Search

2013-10-01

Fatigue cracking is a primary form of distress in hot-mix asphalt. The long-term nature of fatigue due to repeated : loading and aging and its required tie to pavement structure present challenges in terms of evaluating mixture : resistance. This pro...

Antibacterial Effects and Biocompatibility of Titania Nanotubes with Octenidine Dihydrochloride/Poly(lactic-co-glycolic acid).

PubMed

Xu, Zhiqiang; Lai, Yingzhen; Wu, Dong; Huang, Wenxiu; Huang, Sijia; Zhou, Lin; Chen, Jiang

2015-01-01

Titanium (Ti) implants with long-term antibacterial ability and good biocompatibility are highly desirable materials that can be used to prevent implant-associated infections. In this study, titania nanotubes (TNTs) were synthesized on Ti surfaces through electrochemical anodization. Octenidine dihydrochloride (OCT)/poly(lactic-co-glycolic acid) (PLGA) was infiltrated into TNTs using a simple solvent-casting technique. OCT/PLGA-TNTs demonstrated sustained drug release and maintained the characteristic hollow structures of TNTs. TNTs (200 nm in diameter) alone exhibited slight antibacterial effect and good osteogenic activity but also evidently impaired adhesion and proliferation of bone marrow mesenchymal stem cells (BMSCs). OCT/PLGA-TNTs (100 nm in diameter) supported BMSC adhesion and proliferation and showed good osteogenesis-inducing ability. OCT/PLGA-TNTs also exhibited good long-term antibacterial ability within the observation period of 7 d. The synthesized drug carrier with relatively long-term antibacterial ability and enhanced excellent biocompatibility demonstrated significant potential in bone implant applications.

Antibacterial Effects and Biocompatibility of Titania Nanotubes with Octenidine Dihydrochloride/Poly(lactic-co-glycolic acid)

PubMed Central

Xu, Zhiqiang; Lai, Yingzhen; Wu, Dong; Huang, Wenxiu; Huang, Sijia; Zhou, Lin; Chen, Jiang

2015-01-01

Titanium (Ti) implants with long-term antibacterial ability and good biocompatibility are highly desirable materials that can be used to prevent implant-associated infections. In this study, titania nanotubes (TNTs) were synthesized on Ti surfaces through electrochemical anodization. Octenidine dihydrochloride (OCT)/poly(lactic-co-glycolic acid) (PLGA) was infiltrated into TNTs using a simple solvent-casting technique. OCT/PLGA-TNTs demonstrated sustained drug release and maintained the characteristic hollow structures of TNTs. TNTs (200 nm in diameter) alone exhibited slight antibacterial effect and good osteogenic activity but also evidently impaired adhesion and proliferation of bone marrow mesenchymal stem cells (BMSCs). OCT/PLGA-TNTs (100 nm in diameter) supported BMSC adhesion and proliferation and showed good osteogenesis-inducing ability. OCT/PLGA-TNTs also exhibited good long-term antibacterial ability within the observation period of 7 d. The synthesized drug carrier with relatively long-term antibacterial ability and enhanced excellent biocompatibility demonstrated significant potential in bone implant applications. PMID:26090449

Comparison of optical coherence tomography and fundus photography for measuring the optic disc size.

PubMed

Neubauer, Aljoscha S; Krieglstein, Tina R; Chryssafis, Christos; Thiel, Martin; Kampik, Anselm

2006-01-01

To assess the agreement and repeatability of optic nerve head (ONH) size measurements by optical coherence tomography (OCT) as compared to conventional planimetry of fundus photographs in normal eyes. For comparison with planimetry the absolute size of the ONH of 25 eyes from 25 normal subjects were measured by both OCT and digital fundus photography (Zeiss FF camera 450). Repeatability of automated Stratus OCT measurements were investigated by repeatedly measuring the optic disc in five normal subjects. Mean disc size was 1763 +/- 186 vertically and 1632 +/- 160 microm horizontally on planimetry. On OCT, values of 1772 +/- 317 microm vertically (p = 0.82) and a significantly smaller horizontal diameter of 1492 +/- 302 microm (p = 0.04) were obtained. The 95% limits of agreement were (-546 microm; +527 microm) for vertical and (-502 microm; +782 microm) for horizontal planimetric compared to OCT measurements. In some cases large discrepancies existed. Repeatability of automatic measurements of the optic disc by OCT was moderately good with intra-class correlation coefficients (ICC) of 0.78 horizontally and 0.83 vertically. The coefficient of repeatability indicating instrument precision was 80 microm for horizontal and 168 microm for vertical measurements. OCT can be used to determine optic disc margins in moderate agreement with planimetry in normal subjects. However, in some cases significant disagreement with photographic assessment may occur making manual inspection advisable. Automatic disc detection by OCT is moderately repeatable.

Reliability and criterion-related validity of a new repeated agility test

PubMed Central

Makni, E; Jemni, M; Elloumi, M; Chamari, K; Nabli, MA; Padulo, J; Moalla, W

2016-01-01

The study aimed to assess the reliability and the criterion-related validity of a new repeated sprint T-test (RSTT) that includes intense multidirectional intermittent efforts. The RSTT consisted of 7 maximal repeated executions of the agility T-test with 25 s of passive recovery rest in between. Forty-five team sports players performed two RSTTs separated by 3 days to assess the reliability of best time (BT) and total time (TT) of the RSTT. The intra-class correlation coefficient analysis revealed a high relative reliability between test and retest for BT and TT (>0.90). The standard error of measurement (<0.50) showed that the RSTT has a good absolute reliability. The minimal detectable change values for BT and TT related to the RSTT were 0.09 s and 0.58 s, respectively. To check the criterion-related validity of the RSTT, players performed a repeated linear sprint (RLS) and a repeated sprint with changes of direction (RSCD). Significant correlations between the BT and TT of the RLS, RSCD and RSTT were observed (p<0.001). The RSTT is, therefore, a reliable and valid measure of the intermittent repeated sprint agility performance. As this ability is required in all team sports, it is suggested that team sports coaches, fitness coaches and sports scientists consider this test in their training follow-up. PMID:27274109

Perceived Competence and Depressive Symptoms in Children with Reading Problems

ERIC Educational Resources Information Center

MacPhail, Sandra Stewart

2012-01-01

Students with reading problems (RP) exhibit low self-concept in academic and global areas as the result of repeated academic failure and perceived negative feedback from teachers, parents, and peers. Students with RP are also known to experience higher rates of depression in comparison to their normally-achieving (NA) peers. This study explored…

Controversy over Student's Art Exhibit at Yale Raises Issues of Academic Freedom

ERIC Educational Resources Information Center

Wilson, Robin

2008-01-01

This article describes the controversy surrounding a Yale University art student, Aliza Shvarts, who told the campus newspaper that she had repeatedly inseminated herself artificially and then induced abortions as part of her senior thesis. The controversy has created massive reverberations throughout academe, especially in the already hotly…

Establishment and early growth of Populus hybrids irrigated with landfill leachate

Treesearch

Ronald S., Jr. Zalesny; Adam H. Wiese; Edmund O. Bauer; Jill A. Zalesny

2007-01-01

Hybrid poplar genotypes exhibit great potential for tree establishment and growth when irrigated with municipal solid waste landfill leachate. We evaluated the potential for establishment on leachate-irrigated soils by testing: 1) aboveground growth of hybrid poplar during repeated irrigation with landfill leachate and 2) aboveground and belowground biomass after 70 d...

Possible reduced penetrance of expansion of 44 to 47 CAG/CAA repeats in the TATA-binding protein gene in spinocerebellar ataxia type 17.

PubMed

Oda, Masaya; Maruyama, Hirofumi; Komure, Osamu; Morino, Hiroyuki; Terasawa, Hideo; Izumi, Yuishin; Imamura, Tohru; Yasuda, Minoru; Ichikawa, Keiji; Ogawa, Masafumi; Matsumoto, Masayasu; Kawakami, Hideshi

2004-02-01

Spinocerebellar ataxia type 17 (SCA17) is an autosomal dominant cerebellar ataxia caused by expansion of CAG/CAA trinucleotide repeats in the TATA-binding protein (TBP) gene. Because the number of triplets in patients with SCA17 in previous studies ranged from 43 to 63, the normal number of trinucleotide units has been considered to be 42 or less. However, some healthy subjects in SCA17 pedigrees carry alleles with the same number of expanded repeats as patients with SCA17. To investigate the minimum number of CAG/CAA repeats in the TBP gene that causes SCA17. We amplified the region of the TBP gene containing the CAG/CAA repeat by means of polymerase chain reaction and performed fragment and sequence analyses. The subjects included 734 patients with SCA (480 patients with sporadic SCA and 254 patients with familial SCA) without CAG repeat expansions at the SCA1, SCA2, Machado-Joseph disease, SCA6, SCA7, or dentatorubral-pallidolluysian atrophy loci, with 162 healthy subjects, 216 patients with Parkinson disease, and 195 with Alzheimer disease as control subjects. Eight patients with SCA possessed an allele with more than 43 CAG/CAA repeats. Among the non-SCA groups, alleles with 43 to 45 repeats were seen in 3 healthy subjects and 2 with Parkinson disease. In 1 SCA pedigree, a patient with possible SCA17 and her healthy sister had alleles with 45 repeats. A 34-year-old man carrying alleles with 47 and 44 repeats (47/44) had developed progressive cerebellar ataxia and myoclonus at 25 years of age, and he exhibited dementia and pyramidal signs. He was the only affected person in his pedigree, although his father and mother carried alleles with mildly expanded repeats (44/36 and 47/36, respectively). In another pedigree, 1 patient carried a 43-repeat allele, whereas another patient had 2 normal alleles, indicating that the 43-repeat allele may not be pathologic in this family. We estimate that 44 CAG/CAA repeats is the minimum number required to cause SCA17. However, the existence of unaffected subjects with mildly expanded triplets suggests that the TBP gene mutation may not penetrate fully. Homozygosity of alleles with mildly expanded triplet repeats in the TBP gene might contribute to the pathologic phenotype.

Intermolecular ionic cross-linked sulfonated poly(ether ether ketone) membranes containing diazafluorene for direct methanol fuel cell applications

NASA Astrophysics Data System (ADS)

Liang, Yu; Gong, Chenliang; Qi, Zhigang; Li, Hui; Wu, Zhongying; Zhang, Yakui; Zhang, Shujiang; Li, Yanfeng

2015-06-01

A series of novel ionic cross-linking sulfonated poly(ether ether ketone) (SPEEK) membranes containing the diazafluorene functional group are synthesized to reduce the swelling ratio and methanol permeability for direct methanol fuel cell (DMFC) applications. The ionic cross-linking is realized by the interaction between sulfonic acid groups and pyridyl in diazafluorene. The prepared membranes exhibit good mechanical properties, adequate thermal stability, good oxidative stability, appropriate water uptake and low swelling ratio. Moreover, the ionic cross-linked membranes exhibit lower methanol permeability in the range between 0.56 × 10-7 cm2 s-1 and 1.8 × 10-7 cm2 s-1, which is lower than Nafion 117, and they exhibit higher selectivity than Nafion 117 at 30 °C on the basis of applicable proton conductivity.

Synthesis and biological screening of 2'-aryl/benzyl-2-aryl-4-methyl-4',5-bithiazolyls as possible anti-tubercular and antimicrobial agents.

PubMed

Abhale, Yogita K; Sasane, Amit V; Chavan, Abhijit P; Deshmukh, Keshav K; Kotapalli, Sudha Sravanti; Ummanni, Ramesh; Sayyad, Sadikali F; Mhaske, Pravin C

2015-04-13

A series of 2'-aryl/benzyl-2-aryl-4-methyl-4',5-bithiazolyl derivatives, 25-64 were synthesized and evaluated for inhibitory activity against Mycobacterium smegmatis MC(2) 155 strain and antimicrobial activities against four pathogenic bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Proteus vulgaris. Among them, compounds 40, 49, 50, and 54 exhibited moderate to good inhibition on the growth of the bacteria Mycobacterium smegmatis at the concentration of 30 μM. Compounds 26, 40, 44, 54 and 56 exhibited moderate to good antibacterial activity. Compound 5-(2'-(4-fluorobenzyl)thiazol-4'-yl)-2-(4-fluorophenyl)-4-methyl-thiazole (54) exhibited both antitubercular as well as antimicrobial activity against all tested strains. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Chemical synthesis of the tetrasaccharide repeating unit of the O-polysaccharide isolated from Azospirillum brasilense SR80.

PubMed

Sarkar, Vikramjit; Mukhopadhyay, Balaram

2015-04-10

A linear strategy has been developed for the synthesis of the tetrasaccharide repeating unit of the O-polysaccharide from Azospirillum brasilense SR80. Stepwise glycosylation of the rationally protected thioglycoside donors activated by NIS in the presence of La(OTf)3 furnished the target tetrasaccharide. The glycosylation reactions resulted in the formation of the desired linkage with absolute stereoselectivity and afforded the required derivatives in good to excellent yields. The phthalimido group has been used as the precursor of the desired acetamido group to meet the requirement of 1,2-trans glycosidic linkage. Copyright © 2015 Elsevier Ltd. All rights reserved.

Repeated light-dark phase shifts modulate voluntary ethanol intake in male and female high alcohol-drinking (HAD1) rats.

PubMed

Clark, James W; Fixaris, Michael C; Belanger, Gabriel V; Rosenwasser, Alan M

2007-10-01

Chronic disruption of sleep and other circadian biological rhythms, such as occurs in shift work or in frequent transmeridian travel, appears to represent a significant source of allostatic load, leading to the emergence of stress-related physical and psychological illness. Recent animal experiments have shown that these negative health effects may be effectively modeled by exposure to repeated phase shifts of the daily light-dark (LD) cycle. As chronobiological disturbances are thought to promote relapse in abstinent alcoholics, and may also be associated with increased risk of subsequent alcohol abuse in nonalcoholic populations, the present experiment was designed to examine the effects of repeated LD phase shifts on voluntary ethanol intake in rats. A selectively bred, high alcohol-drinking (HAD1) rat line was utilized to increase the likelihood of excessive alcoholic-like drinking. Male and female rats of the selectively bred HAD1 rat line were maintained individually under a LD 12:12 cycle with both ethanol (10% v/v) and water available continuously. Animals in the experimental group were subjected to repeated 6-hour LD phase advances at 3 to 4 week intervals, while control rats were maintained under a stable LD cycle throughout the study. Contact-sensing drinkometers were used to monitor circadian lick patterns, and ethanol and water intakes were recorded weekly. Control males showed progressively increasing ethanol intake and ethanol preference over the course of the study, but males exposed to chronic LD phase shifts exhibited gradual decreases in ethanol drinking. In contrast, control females displayed decreasing ethanol intake and ethanol preference over the course of the experiment, while females exposed to experimental LD phase shifts exhibited a slight increase in ethanol drinking. Chronic circadian desynchrony induced by repeated LD phase shifts resulted in sex-specific modulation of voluntary ethanol intake, reducing ethanol intake in males while slightly increasing intake in females. While partially contrary to initial predictions, these results are consistent with extensive prior research showing that chronic stress may either increase or decrease ethanol intake, depending on strain, sex, stressor type, and experimental history. Thus, repeated LD phase shifts may provide a novel chronobiological model for the analysis of stress effects on alcohol intake.

Low-loss electromagnetic composites for RF and microwave applications.

PubMed

Wang, Hong; Yang, Haibo; Xiang, Feng; Yao, Xi

2011-09-01

Low-loss electromagnetic composites with high permittivity and permeability will benefit the miniaturization and multifunctional of RF devices. A kind of low-loss dielectric-magnetic ceramic-ceramic composite was developed by hybrid processing technology with the goal of integrating the dielectric properties and magnetic properties. The hybrid processing technology exhibits the advantage of lowered sintering temperatures for the composites while retaining good microstructure and high performance. By introducing elastomer as matrix, a kind of flexible low-loss dielectric-magnetic ceramic-polymer composite was prepared and studied. The obtained flexible dielectric-magnetic ceramic-polymer composite exhibited low loss and good mechanical properties. The results show good effects on lowering the dielectric loss and extending the cut-off magnetic frequency of the electromagnetic composite. Methods for tailoring the properties of the multifunctional composites were proposed and discussed.

ANALYSIS OF THE CITIES INTENSIVELY REPORTED BY TV NEWS DURING THE EMERGENCY PERIOD ON THE 2011 OFF THE PACIFIC COAST OF TOHOKU EARTHQUAKE DISASTER

NASA Astrophysics Data System (ADS)

Kokubun, Eriko; Numada, Muneyoshi; Meguro, Kimiro

In the 2011 off the Pacific coast of Tohoku earthquake, we could observe concentration of news on damage and disaster response activity of specific municipalities and the high emphasis on the nuclear power plant accident and so on. The concentration of TV news caused the concentration of support such as releaf goods and donations to the specific area. This problem was repeated from the past disaster. The purpose of this research is to analyze the cities where was repeatedly reported by TV news during the emergency period on the 2011 off the pacific coast of tohoku earthquake disaster. This research defined the ratio of reported-city to show the comparison of the level of repeatedly reported cities. The results shows the big difference of reported times among the cities with same number of casualities.

Analysis of the giant genomes of Fritillaria (Liliaceae) indicates that a lack of DNA removal characterizes extreme expansions in genome size.

PubMed

Kelly, Laura J; Renny-Byfield, Simon; Pellicer, Jaume; Macas, Jiří; Novák, Petr; Neumann, Pavel; Lysak, Martin A; Day, Peter D; Berger, Madeleine; Fay, Michael F; Nichols, Richard A; Leitch, Andrew R; Leitch, Ilia J

2015-10-01

Plants exhibit an extraordinary range of genome sizes, varying by > 2000-fold between the smallest and largest recorded values. In the absence of polyploidy, changes in the amount of repetitive DNA (transposable elements and tandem repeats) are primarily responsible for genome size differences between species. However, there is ongoing debate regarding the relative importance of amplification of repetitive DNA versus its deletion in governing genome size. Using data from 454 sequencing, we analysed the most repetitive fraction of some of the largest known genomes for diploid plant species, from members of Fritillaria. We revealed that genomic expansion has not resulted from the recent massive amplification of just a handful of repeat families, as shown in species with smaller genomes. Instead, the bulk of these immense genomes is composed of highly heterogeneous, relatively low-abundance repeat-derived DNA, supporting a scenario where amplified repeats continually accumulate due to infrequent DNA removal. Our results indicate that a lack of deletion and low turnover of repetitive DNA are major contributors to the evolution of extremely large genomes and show that their size cannot simply be accounted for by the activity of a small number of high-abundance repeat families. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Quantitative analysis of TALE-DNA interactions suggests polarity effects.

PubMed

Meckler, Joshua F; Bhakta, Mital S; Kim, Moon-Soo; Ovadia, Robert; Habrian, Chris H; Zykovich, Artem; Yu, Abigail; Lockwood, Sarah H; Morbitzer, Robert; Elsäesser, Janett; Lahaye, Thomas; Segal, David J; Baldwin, Enoch P

2013-04-01

Transcription activator-like effectors (TALEs) have revolutionized the field of genome engineering. We present here a systematic assessment of TALE DNA recognition, using quantitative electrophoretic mobility shift assays and reporter gene activation assays. Within TALE proteins, tandem 34-amino acid repeats recognize one base pair each and direct sequence-specific DNA binding through repeat variable di-residues (RVDs). We found that RVD choice can affect affinity by four orders of magnitude, with the relative RVD contribution in the order NG > HD ≈ NN > NI > NK. The NN repeat preferred the base G over A, whereas the NK repeat bound G with 10(3)-fold lower affinity. We compared AvrBs3, a naturally occurring TALE that recognizes its target using some atypical RVD-base combinations, with a designed TALE that precisely matches 'standard' RVDs with the target bases. This comparison revealed unexpected differences in sensitivity to substitutions of the invariant 5'-T. Another surprising observation was that base mismatches at the 5' end of the target site had more disruptive effects on affinity than those at the 3' end, particularly in designed TALEs. These results provide evidence that TALE-DNA recognition exhibits a hitherto un-described polarity effect, in which the N-terminal repeats contribute more to affinity than C-terminal ones.

Discounting of Delayed Rewards Is Not Hyperbolic

ERIC Educational Resources Information Center

Luhmann, Christian C.

2013-01-01

Delay discounting refers to decision-makers' tendency to value immediately available goods more than identical goods available only after some delay. In violation of standard economic theory, decision-makers frequently exhibit dynamic inconsistency; their preferences change simply due to the passage of time. The standard explanation for this…

A Dynamic Tandem Repeat in Monocotyledons Inferred from a Comparative Analysis of Chloroplast Genomes in Melanthiaceae.

PubMed

Do, Hoang Dang Khoa; Kim, Joo-Hwan

2017-01-01

Chloroplast genomes (cpDNA) are highly valuable resources for evolutionary studies of angiosperms, since they are highly conserved, are small in size, and play critical roles in plants. Slipped-strand mispairing (SSM) was assumed to be a mechanism for generating repeat units in cpDNA. However, research on the employment of different small repeated sequences through SSM events, which may induce the accumulation of distinct types of repeats within the same region in cpDNA, has not been documented. Here, we sequenced two chloroplast genomes from the endemic species Heloniopsis tubiflora (Korea) and Xerophyllum tenax (USA) to cover the gap between molecular data and explore "hot spots" for genomic events in Melanthiaceae. Comparative analysis of 23 complete cpDNA sequences revealed that there were different stages of deletion in the rps16 region across the Melanthiaceae. Based on the partial or complete loss of rps16 gene in cpDNA, we have firstly reported potential molecular markers for recognizing two sections ( Veratrum and Fuscoveratrum ) of Veratrum . Melathiaceae exhibits a significant change in the junction between large single copy and inverted repeat regions, ranging from trnH_GUG to a part of rps3 . Our results show an accumulation of tandem repeats in the rpl23-ycf2 regions of cpDNAs. Small conserved sequences exist and flank tandem repeats in further observation of this region across most of the examined taxa of Liliales. Therefore, we propose three scenarios in which different small repeated sequences were used during SSM events to generate newly distinct types of repeats. Occasionally, prior to the SSM process, point mutation event and double strand break repair occurred and induced the formation of initial repeat units which are indispensable in the SSM process. SSM may have likely occurred more frequently for short repeats than for long repeat sequences in tribe Parideae (Melanthiaceae, Liliales). Collectively, these findings add new evidence of dynamic results from SSM in chloroplast genomes which can be useful for further evolutionary studies in angiosperms. Additionally, genomics events in cpDNA are potential resources for mining molecular markers in Liliales.

Normal movement selectivity in autism.

PubMed

Dinstein, Ilan; Thomas, Cibu; Humphreys, Kate; Minshew, Nancy; Behrmann, Marlene; Heeger, David J

2010-05-13

It has been proposed that individuals with autism have difficulties understanding the goals and intentions of others because of a fundamental dysfunction in the mirror neuron system. Here, however, we show that individuals with autism exhibited not only normal fMRI responses in mirror system areas during observation and execution of hand movements but also exhibited typical movement-selective adaptation (repetition suppression) when observing or executing the same movement repeatedly. Movement selectivity is a defining characteristic of neurons involved in movement perception, including mirror neurons, and, as such, these findings argue against a mirror system dysfunction in autism. Copyright 2010 Elsevier Inc. All rights reserved.

Phylogenetic analysis of symbionts in feather-feeding lice of the genus Columbicola: evidence for repeated symbiont replacements

PubMed Central

2013-01-01

Background Many groups of insects have obligate bacterial symbionts that are vertically transmitted. Such associations are typically characterized by the presence of a monophyletic group of bacteria living in a well-defined host clade. In addition the phylogeny of the symbiotic bacteria is typically congruent with that of the host, signifying co-speciation. Here we show that bacteria living in a single genus of feather lice, Columbicola (Insecta: Phthiraptera), present an exception to this typical pattern. Results The phylogeny of Columbicola spp. symbionts revealed the presence of three candidate clades, with the most species-rich clade having a comb-like topology with very short internodes and long terminal branches. Evolutionary simulations indicate that this topology is characteristic of a process of repeated symbiont replacement over a brief time period. The two remaining candidate clades in our study exhibit high levels of nucleotide substitution, suggesting accelerated molecular evolution due to relaxed purifying selection or smaller effective population size, which is typical of many vertically transmitted insect symbionts. Representatives of the fast-evolving and slow-evolving symbiont lineages exhibit the same localization, migration, and transmission patterns in their hosts, implying direct replacement. Conclusions Our findings suggest that repeated, independent symbiont replacements have taken place over the course of the relatively recent radiation of Columbicola spp. These results are compatible with the notion that lice and other insects have the capability to acquire novel symbionts through the domestication of progenitor strains residing in their local environment. PMID:23725492

Bidirectional nucleolar dysfunction in C9orf72 frontotemporal lobar degeneration.

PubMed

Mizielinska, Sarah; Ridler, Charlotte E; Balendra, Rubika; Thoeng, Annora; Woodling, Nathan S; Grässer, Friedrich A; Plagnol, Vincent; Lashley, Tammaryn; Partridge, Linda; Isaacs, Adrian M

2017-04-18

An intronic GGGGCC expansion in C9orf72 is the most common known cause of both frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). The repeat expansion leads to the generation of sense and antisense repeat RNA aggregates and dipeptide repeat (DPR) proteins, generated by repeat-associated non-ATG translation. The arginine-rich DPR proteins poly(glycine-arginine or GR) and poly(proline-arginine or PR) are potently neurotoxic and can localise to the nucleolus when expressed in cells, resulting in enlarged nucleoli with disrupted functionality. Furthermore, GGGGCC repeat RNA can bind nucleolar proteins in vitro. However, the relevance of nucleolar stress is unclear, as the arginine-rich DPR proteins do not localise to the nucleolus in C9orf72-associated FTLD/ALS (C9FTLD/ALS) patient brain. We measured nucleolar size in C9FTLD frontal cortex neurons using a three-dimensional, volumetric approach. Intriguingly, we found that C9FTLD brain exhibited bidirectional nucleolar stress. C9FTLD neuronal nucleoli were significantly smaller than control neuronal nucleoli. However, within C9FTLD brains, neurons containing poly(GR) inclusions had significantly larger nucleolar volumes than neurons without poly(GR) inclusions. In addition, expression of poly(GR) in adult Drosophila neurons led to significantly enlarged nucleoli. A small but significant increase in nucleolar volume was also observed in C9FTLD frontal cortex neurons containing GGGGCC repeat-containing RNA foci. These data show that nucleolar abnormalities are a consistent feature of C9FTLD brain, but that diverse pathomechanisms are at play, involving both DPR protein and repeat RNA toxicity.

Structure and stability of the ankyrin domain of the Drosophila Notch receptor.

PubMed

Zweifel, Mark E; Leahy, Daniel J; Hughson, Frederick M; Barrick, Doug

2003-11-01

The Notch receptor contains a conserved ankyrin repeat domain that is required for Notch-mediated signal transduction. The ankyrin domain of Drosophila Notch contains six ankyrin sequence repeats previously identified as closely matching the ankyrin repeat consensus sequence, and a putative seventh C-terminal sequence repeat that exhibits lower similarity to the consensus sequence. To better understand the role of the Notch ankyrin domain in Notch-mediated signaling and to examine how structure is distributed among the seven ankyrin sequence repeats, we have determined the crystal structure of this domain to 2.0 angstroms resolution. The seventh, C-terminal, ankyrin sequence repeat adopts a regular ankyrin fold, but the first, N-terminal ankyrin repeat, which contains a 15-residue insertion, appears to be largely disordered. The structure reveals a substantial interface between ankyrin polypeptides, showing a high degree of shape and charge complementarity, which may be related to homotypic interactions suggested from indirect studies. However, the Notch ankyrin domain remains largely monomeric in solution, demonstrating that this interface alone is not sufficient to promote tight association. Using the structure, we have classified reported mutations within the Notch ankyrin domain that are known to disrupt signaling into those that affect buried residues and those restricted to surface residues. We show that the buried substitutions greatly decrease protein stability, whereas the surface substitutions have only a marginal affect on stability. The surface substitutions are thus likely to interfere with Notch signaling by disrupting specific Notch-effector interactions and map the sites of these interactions.

Effect of gender on fatigue and recovery following maximal intensity repeated sprint performance.

PubMed

Laurent, C M; Green, J M; Bishop, P A; Sjökvist, J; Schumacker, R E; Richardson, M T; Curtner-Smith, M

2010-09-01

This study investigated the effects of gender on repeated, maximal-intensity intermittent sprint exercise following variable day-to-day recovery periods. Sixteen volunteers (8 men, 8 women) performed four trials of high-intensity intermittent sprint exercise consisting of three bouts of eight 30 m sprints (total of 24 sprints). Following completion of the baseline trial, in repeated-measures design, participants were assigned, in counter-balanced order, variable recovery periods of 24, 48, and 72 h whereupon they repeated an identical exercise trial. Results from a series of 4 (trial) x 3 (bout) repeated measures ANOVAs revealed men produced significantly (P < 0.01) faster times throughout all bouts and trials of repeated sprint exercise. Additionally, women exhibited significantly lower (P < 0.05) blood lactate concentration and significantly lower (P < 0.05) decrement in performance, indicating increased resistance to fatigue during repeated exercise sessions. There were no significant differences (P > 0.05) between genders for heart rate or rating of perceived exertion during or following trials. There were no significant differences for overall sprint performance within either gender among trials. These results indicate men, while able to produce higher absolute power outputs (i.e., lower sprint time), demonstrate higher decrement scores within a trial compared to women, thus suggesting women may recover faster and fatigue less. Also, gender differences affecting recovery within in a trial were observed to be diminished between trials (i.e., day-to-day recovery) of maximal intermittent sprint work evidenced by the observed stability of performance between trials following various recovery durations.

Polypyrrole-polyoxometalate/reduced graphene oxide ternary nanohybrids for flexible, all-solid-state supercapacitors.

PubMed

Chen, Yuyun; Han, Min; Tang, Yujia; Bao, Jianchun; Li, Shunli; Lan, Yaqian; Dai, Zhihui

2015-08-11

Novel polypyrrole-polyoxometalate/reduced graphene oxide ternary nanohybrids (TNHs) are synthesized via a one-pot redox relay strategy. The TNHs exhibit high areal specific capacitance (2.61 mF cm(-2)), and the fabricated solid device also exhibits good rate capability, excellent flexibility and mechanical stability.

34 CFR 101.74 - Exhibits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false Exhibits. 101.74 Section 101.74 Education Regulations of the Offices of the Department of Education OFFICE FOR CIVIL RIGHTS, DEPARTMENT OF EDUCATION... objection thereto is filed prior to the hearing or unless good cause is shown at the hearing for failure to...

The medial prefrontal cortex exhibits money illusion

PubMed Central

Weber, Bernd; Rangel, Antonio; Wibral, Matthias; Falk, Armin

2009-01-01

Behavioral economists have proposed that money illusion, which is a deviation from rationality in which individuals engage in nominal evaluation, can explain a wide range of important economic and social phenomena. This proposition stands in sharp contrast to the standard economic assumption of rationality that requires individuals to judge the value of money only on the basis of the bundle of goods that it can buy—its real value—and not on the basis of the actual amount of currency—its nominal value. We used fMRI to investigate whether the brain's reward circuitry exhibits money illusion. Subjects received prizes in 2 different experimental conditions that were identical in real economic terms, but differed in nominal terms. Thus, in the absence of money illusion there should be no differences in activation in reward-related brain areas. In contrast, we found that areas of the ventromedial prefrontal cortex (vmPFC), which have been previously associated with the processing of anticipatory and experienced rewards, and the valuation of goods, exhibited money illusion. We also found that the amount of money illusion exhibited by the vmPFC was correlated with the amount of money illusion exhibited in the evaluation of economic transactions. PMID:19307555

Fabricate Optical Microfiber by Using Flame Brushing Technique and Coated with Polymer Polyaniline for Sensing Application

NASA Astrophysics Data System (ADS)

Razak, N. A.; Hamida, B. A.; Irawati, N.; Habaebi, M. H.

2017-06-01

Adiabaticity is one of the essential criteria in producing good fabricated tapered fibers. Good tapered fibers can be use in sensor application such as humidity sensor, temperature sensor and refractive index sensor. In this paper, good tapering silica fiber is produced by using flame brushing technique and then, the microfiber is coated with polymer Polyaniline (PAni) to sense different type of alcohols with different concentrations. The outcome of this experiment gives excellent repeatability in the detection of alcohol sensing with a sensitivity of 0.1332 μW/% and a resolution of 3.764%. In conclusion, conducting polymer coated optical microfiber sensor for alcohol detection with low cost, effective and simple set-up was successfully achieved in this study.

A Comparison of Cognitive Flexibility and Metalinguistic Skills in Adult Good and Poor Comprehenders

ERIC Educational Resources Information Center

Cartwright, Kelly B.; Bock, Allison M.; Coppage, Elizabeth A.; Hodgkiss, Melinda D.; Nelson, Marisa Isaac

2017-01-01

Good and poor comprehenders exhibit different profiles of cognitive abilities, despite comparable decoding skills. Recent work suggests that executive functions, particularly cognitive flexibility, may underlie poor comprehenders' difficulties in childhood and adulthood. However, metalinguistic skills that enable readers to reflect on various…

Repeatability and reproducibility of ocular biometry using a new noncontact optical low-coherence interferometer.

PubMed

Huang, Jinhai; Savini, Giacomo; Wu, Fan; Yu, Xinxin; Yang, Jing; Yu, Ayong; Yu, Ye; Wang, Qinmei

2015-10-01

To assess the precision of ocular biometry with a new noncontact optical low-coherence interferometer (Aladdin) in healthy subjects and patients with cataracts. Eye Hospital of Wenzhou Medical University, Wenzhou, China. Observational cross-sectional study. Eyes from healthy subjects and eyes from patients with cataracts were examined with the new interferometer. Axial length (AL), anterior chamber depth (ACD), keratometry (K), and white-to-white (WTW) values were measured by 2 operators. The test-retest repeatability, coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were calculated to evaluate intraoperator repeatability. Different-operator comparison was analyzed with paired t tests and Bland-Altman plots to assess interoperator reproducibility. Ninety-eight people were enrolled for this study, of which 52 eyes were from healthy subjects and 46 eyes were from patients with cataracts. The AL was the most repeatable and reproducible parameter. The ACD, K values, and WTW measurements were highly repeatable in healthy subjects with CoV less than 0.89% and ICC more than 0.94. However, in patients with cataracts, high repeatability could only be observed for AL, ACD, and K values, whereas WTW measurement had test-retest repeatability of 0.80 mm and an ICC of 0.795. Bland-Altman analysis also showed good agreement between the 2 operators for ocular component measurements, except that the WTW in patients with cataracts had wider 95% limits of agreement (range -0.88 to 0.95 mm). The new biometer showed excellent intraoperator repeatability and interoperator reproducibility for AL, ACD, and K values measurements in both groups. The precision of WTW measurements was lower in patients with cataracts. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Validation of a Hartmann-Moiré wavefront sensor with large dynamic range.

PubMed

Wei, Xin; Van Heugten, Tony; Thibos, Larry

2009-08-03

Our goal was to validate the accuracy, repeatability, sensitivity, and dynamic range of a Hartmann-Moiré (HM) wavefront sensor (PixelOptics, Inc.) designed for ophthalmic applications. Testing apparatus injected a 4 mm diameter monochromatic (532 nm) beam of light into the wavefront sensor for measurement. Controlled amounts of defocus and astigmatism were introduced into the beam with calibrated spherical (-20D to + 18D) and cylindrical (-8D to + 8D) lenses. Repeatability was assessed with three repeated measurements within a 2-minute period. Correlation coefficients between mean wavefront measurements (n = 3) and expected wavefront vergence for both sphere and cylinder lenses were >0.999. For spherical lenses, the sensor was accurate to within 0.1D over the range from -20D to + 18D. For cylindrical lenses, the sensor was accurate to within 0.1D over the range from -8D to + 8D. The primary limitation to demonstrating an even larger dynamic range was the increasingly critical requirements for optical alignment. Sensitivity to small changes of vergence was constant over the instrument's full dynamic range. Repeatability of measurements for fixed condition was within 0.01D. The Hartmann-Moiré wavefront sensor measures defocus and astigmatism accurately and repeatedly with good sensitivity over a large dynamic range required for ophthalmic applications.

Cardiopulmonary exercise testing early after stroke using feedback-controlled robotics-assisted treadmill exercise: test-retest reliability and repeatability.

PubMed

Stoller, Oliver; de Bruin, Eling D; Schindelholz, Matthias; Schuster-Amft, Corina; de Bie, Rob A; Hunt, Kenneth J

2014-10-11

Exercise capacity is seriously reduced after stroke. While cardiopulmonary assessment and intervention strategies have been validated for the mildly and moderately impaired populations post-stroke, there is a lack of effective concepts for stroke survivors suffering from severe motor limitations. This study investigated the test-retest reliability and repeatability of cardiopulmonary exercise testing (CPET) using feedback-controlled robotics-assisted treadmill exercise (FC-RATE) in severely motor impaired individuals early after stroke. 20 subjects (age 44-84 years, <6 month post-stroke) with severe motor limitations (Functional Ambulatory Classification 0-2) were selected for consecutive constant load testing (CLT) and incremental exercise testing (IET) within a powered exoskeleton, synchronised with a treadmill and a body weight support system. A manual human-in-the-loop feedback system was used to guide individual work rate levels. Outcome variables focussed on standard cardiopulmonary performance parameters. Relative and absolute test-retest reliability were assessed by intraclass correlation coefficients (ICC), standard error of the measurement (SEM), and minimal detectable change (MDC). Mean difference, limits of agreement, and coefficient of variation (CoV) were estimated to assess repeatability. Peak performance parameters during IET yielded good to excellent relative reliability: absolute peak oxygen uptake (ICC =0.82), relative peak oxygen uptake (ICC =0.72), peak work rate (ICC =0.91), peak heart rate (ICC =0.80), absolute gas exchange threshold (ICC =0.91), relative gas exchange threshold (ICC =0.88), oxygen cost of work (ICC =0.87), oxygen pulse at peak oxygen uptake (ICC =0.92), ventilation rate versus carbon dioxide output slope (ICC =0.78). For these variables, SEM was 4-13%, MDC 12-36%, and CoV 0.10-0.36. CLT revealed high mean differences and insufficient test-retest reliability for all variables studied. This study presents first evidence on reliability and repeatability for CPET in severely motor impaired individuals early after stroke using a feedback-controlled robotics-assisted treadmill. The results demonstrate good to excellent test-retest reliability and appropriate repeatability for the most important peak cardiopulmonary performance parameters. These findings have important implications for the design and implementation of cardiovascular exercise interventions in severely impaired populations. Future research needs to develop advanced control strategies to enable the true limit of functional exercise capacity to be reached and to further assess test-retest reliability and repeatability in larger samples.

Science Students and the Social Sciences: Strange Bedfellows?

ERIC Educational Resources Information Center

Yeong, Foong May

2014-01-01

With various internet resources available to students, the main aim of a good university education today should not merely be to provide students with content knowledge, but rather to equip them with essential skills necessary to develop into lifelong learners. Among science educators, repeated calls have been made to promote a more holistic…

Essential Questions

ERIC Educational Resources Information Center

Wilhelm, Jeffrey D.

2012-01-01

The secret to teaching may be as simple as asking students good questions--and then giving them the opportunity to find the answers. The author shares how he uses essential questions that set the class off on an inquiry. Rather than consuming information that he distributes and then repeating it on a test, students carry out their own…

Ireland's Generic Repeat Design Schools Programme

ERIC Educational Resources Information Center

Sheppard, Tony

2011-01-01

The Irish Department of Education and Skills (DoE) is strongly committed to energy efficiency and to reducing CO[subscript 2] by developing and implementing energy level ceilings in relation to school design that aim to remain below half of the accepted good practice in the field. This approach works within normal departmental budgetary limits to…

Nurses are leading the way in changing attitudes to dementia.

PubMed

Bates, Jane

2016-08-10

My father and I had a pact - we would never repeat the daft things my grandmother said. We just couldn't bear people laughing at her. My granny had always been warm, witty and wise. Now in her eighties, she was in good form physically, but her memory had left the building.

Efforts to update firefighter safety zone guidelines

Treesearch

Bret Butler

2009-01-01

One of the most critical decisions made on wildland fires is the identification of suitable safety zones for firefighters during daily fire management operations. To be effective (timely, repeatable, and accurate), these decisions rely on good training and judgment, but also on clear, concise guidelines. This article is a summary of safety zone guidelines and the...

Doing Right Things Right

ERIC Educational Resources Information Center

Perna, Mark C.

2006-01-01

Attracting quality students in sufficient volume requires schools to do the right things right. Doing right things right is a combination of what they do and how well they do it. Successful enrollment marketing, like all good marketing, depends on consistency of effort and doing enough of the right things in the right way, repeatedly. Here, the…

Can Teaching Social Dilemmas Make People More Prosocial? An Experiment

ERIC Educational Resources Information Center

Martins, Julia; Fortmüller, Richard; Powell, Owen

2017-01-01

Economics and business students regularly behave less prosocially than others. Can ethics training reverse this tendency? Results from a repeated public goods experiment reveal that it can. Students who attend an interactive lecture on social dilemmas show significantly more cooperation than others. However, the lecture does not appear to increase…

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

Nata, Iryanti Fatyasari, E-mail: yanti_tkunlam@yahoo.com; Irawan, Chairul; Mardina, Primata

Highly sulfonated carbonaceous spheres with diameter of 100–500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO{sub 3}H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO{sub 3}H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRSmore » concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst. - Highlights: • Carbon solid acid was successfully prepared by one-step hydrothermal carbonization. • The acrylic acid as monomer was effectively reduce the diameter size of particle. • The solid acid catalyst show good catalytic performance of starch hydrolysis. • The solid acid catalyst is not significantly deteriorated after repeated use.« less

Development of dopant-free conductive bioelastomers

PubMed Central

Xu, Cancan; Huang, Yihui; Yepez, Gerardo; Wei, Zi; Liu, Fuqiang; Bugarin, Alejandro; Tang, Liping; Hong, Yi

2016-01-01

Conductive biodegradable materials are of great interest for various biomedical applications, such as tissue repair and bioelectronics. They generally consist of multiple components, including biodegradable polymer/non-degradable conductive polymer/dopant, biodegradable conductive polymer/dopant or biodegradable polymer/non-degradable inorganic additives. The dopants or additives induce material instability that can be complex and possibly toxic. Material softness and elasticity are also highly expected for soft tissue repair and soft electronics. To address these concerns, we designed a unicomponent dopant-free conductive polyurethane elastomer (DCPU) by chemically linking biodegradable segments, conductive segments, and dopant molecules into one polymer chain. The DCPU films which had robust mechanical properties with high elasticity and conductivity can be degraded enzymatically and by hydrolysis. It exhibited great electrical stability in physiological environment with charge. Mouse 3T3 fibroblasts survived and proliferated on these films exhibiting good cytocompatibility. Polymer degradation products were non-toxic. DCPU could also be processed into a porous scaffold and in an in vivo subcutaneous implantation model, exhibited good tissue compatibility with extensive cell infiltration over 2 weeks. Such biodegradable DCPU with good flexibility and elasticity, processability, and electrical stability may find broad applications for tissue repair and soft/stretchable/wearable bioelectronics. PMID:27686216

Perceptual accuracy and conflicting effects of certainty on risk-taking behaviour.

PubMed

Shafir, Sharoni; Reich, Taly; Tsur, Erez; Erev, Ido; Lotem, Arnon

2008-06-12

The 'certainty effect' is a notable violation of expected utility theory by decision makers. It shows that people's tendency to select the safer of two prospects increases when this prospect provides a good outcome with certainty (for example, people prefer a monetary gain of 3 with certainty over 4 with a probability of 0.8, but do not prefer 3 with a probability of 0.25 over 4 with a probability of 0.2). Subsequent work on experience-based decision making in rats extended the certainty effect to other animals, suggesting its generality across different species and different decision-making mechanisms. However, an attempt to replicate this study with human subjects showed a surprising 'reversed certainty effect', namely, the tendency to prefer the safer option decreases when this prospect is associated with certainty (and people now prefer 4 with a probability of 0.8 over 3 with certainty). Here we show that these conflicting results can be explained by perceptual noise and that the certainty effect can be restored experimentally by reducing perceptual accuracy. Using complementary experiments in humans and honeybees (Apis mellifera), we show that by manipulating perceptual accuracy in experience-based tasks, both the certainty and the reversed certainty effects can be exhibited by humans and other animals: the certainty effect emerges when it is difficult to discriminate between the different rewards, whereas the reversed certainty effect emerges when discrimination is easy. Our results fit a simple process-based model of matching behaviour, capable of explaining the certainty effect in humans and other animals that make repeated decisions based on experience. This mechanism should probably be distinguished from those involved in the original certainty effect that was exhibited by human subjects in single description-based problems.

Preparation of stable tetraethylenepentamine-modified ordered mesoporous silica sorbents by recycling natural Equisetum ramosissimum.

PubMed

Liu, Shou-Heng; Kuok, Chi-Hong

2018-01-01

It is well-known that global warming of the earth is caused by the progressive increase of CO 2 concentration in the environment due to the huge utilization of fossil fuels. As a result, the development of an efficient and economic method to capture CO 2 from large stationary sources, such as coal-fired power plants, cement and steel factories, and so on is urgent. In this study, ordered mesoporous silicas (E-SBA-15) have been prepared by using Equisetum ramosissimum plants as the silica sources and their subsequently incorporating with amino-containing compounds (tetraethylenepentamine, TEPA) and stabilizers (titanium isopropoxide, TIP). A variety of different spectroscopic and analytical techniques, such as nitrogen adsorption-desorption isotherms, low-angle X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transformed infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA) are used to characterize the physicochemical properties of various materials. CO 2 adsorption capacities of prepared sorbents at 75 °C are obtained by TGA at atmospheric pressure. Among all sorbents, TEPA impregnated E-SBA-15 sorbents possess the highest CO 2 sorption capacity (1.60 mmol CO 2 g -1 sorbent ) under ambient pressure using dry 15% CO 2 . However, TEPA/TIP incorporated E-SBA-15 sorbents exhibit enhanced durability during repeated sorption-desorption cycles compared to the above-mentioned sorbents. This significant enhancement in the stability of CO 2 sorption-desorption process is most likely due to the decreased decomposition/leaching of TEPA which is restricted via the steric effect of TIP. These synthesized sorbents from inexpensive resources (agricultural waste) exhibit good sorbent capacity and surpassing regenerability, revealing a promising CO 2 sorbent for the cost-effective applications in a cyclic adsorption process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Integrated multienzyme electrochemical biosensors for the determination of glycerol in wines.

PubMed

Gamella, M; Campuzano, S; Reviejo, A J; Pingarrón, J M

2008-02-25

The construction and performance of integrated amperometric biosensors for the determination of glycerol are reported. Two different biosensor configurations have been evaluated: one based on the glycerol dehydrogenase/diaphorase (GDH/DP) bienzyme system, and another using glycerol kinase/glycerol-3-phosphate oxidase/peroxidase (GK/GPOx/HRP). Both enzyme systems were immobilized together with the mediator tetrathiafulvalene (TTF) on a 3-mercaptopropionic acid (MPA) self-assembled monolayer (SAM)-modified gold electrode by using a dialysis membrane. The electrochemical oxidation of TTF at +150mV (vs. Ag/AgCl), and the reduction of TTF(+) at 0mV were used for the monitoring of the enzyme reactions for the bienzyme and trienzyme configurations, respectively. Experimental variables concerning both the biosensors composition and the working conditions were optimized for each configuration. A good repeatability of the measurements with no need of cleaning or pretreatment of the biosensors was obtained in both cases. After 51 days of use, the GDH/DP biosensor still exhibited 87% of the original sensitivity, while the GK/GPOx/HRP biosensor yielded a 46% of the original response after 8 days. Calibration graphs for glycerol with linear ranges of 1.0x10(-6) to 2.0x10(-5) or 1.0x10(-6) to 1.0x10(-5)M glycerol and sensitivities of 1214+/-21 or 1460+/-34microAM(-1) were obtained with GDH/DP and GK/GPOx/HRP biosensors, respectively. The calculated detection limits were 4.0x10(-7) and 3.1x10(-7)M, respectively. The biosensors exhibited a great sensitivity with no significant interferences in the analysis of wines. The biosensors were applied to the determination of glycerol in 12 different wines and the results advantageously compared with those provided by a commercial enzyme kit.

Repeated suppression of lymphocyte blastogenesis following vaccinations of CPV-immune dogs with modified-live CPV vaccines.

PubMed

Mastro, J M; Axthelm, M; Mathes, L E; Krakowka, S; Ladiges, W; Olsen, R G

1986-09-01

A commercially available modified-live canine parvovirus (CPV) vaccine was evaluated for its immunosuppressive properties in eight random-bred dogs, all with circulatory antibody to CPV. Three of the eight dogs exhibited a significant decrease in lymphocyte blastogenesis after vaccine administration. In these dogs, this decrease in blastogenesis was of short duration and was consistently observed after repeated administrations of the vaccine. Neither gastroenteritis, fever nor leukopenia, signs indicative of virulent canine parvovirus infection, were detected in these animals. In addition, lymphocytes from these dogs lacked Ia antigen expression. This study demonstrated that the immunomodulating effects of ML-CPV is not observed in all animals yet is consistent in affected individuals.

KIC 8462852 Brightness Pattern Repeating Every 1600 days

NASA Astrophysics Data System (ADS)

Gary, Bruce; Bourne, Rafik

2017-12-01

Observations of KIC 8462852 (aka Boyajian's Star) reveal a yearlong fade pattern that is remarkably similar to the fade pattern derived from Kepler mission observations. The ground-based observations reported here can be described as a gradual fade that ended in late 2016 with the beginning of a yearlong U-shaped fade of 1.1 percent. Near the end of this U-shaped fade a series of very brief dips occurred. The Kepler data exhibit a similar pattern 1600 days earlier, except with an abrupt end of observations before the U-shape recovery. Observations lasting many years are needed, especially during our predicted repeat of the U-shape and short dip pattern in 2021.

Competing cues: Older adults rely on knowledge in the face of fluency.

PubMed

Brashier, Nadia M; Umanath, Sharda; Cabeza, Roberto; Marsh, Elizabeth J

2017-06-01

Consumers regularly encounter repeated false claims in political and marketing campaigns, but very little empirical work addresses their impact among older adults. Repeated statements feel easier to process, and thus more truthful, than new ones (i.e., illusory truth). When judging truth, older adults' accumulated general knowledge may offset this perception of fluency. In two experiments, participants read statements that contradicted information stored in memory; a post-experimental knowledge check confirmed what individual participants knew. Unlike young adults, older adults exhibited illusory truth only when they lacked knowledge about claims. This interaction between knowledge and fluency extends dual-process theories of aging. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Mapping Simple Repeated DNA Sequences in Heterochromatin of Drosophila Melanogaster

PubMed Central

Lohe, A. R.; Hilliker, A. J.; Roberts, P. A.

1993-01-01

Heterochromatin in Drosophila has unusual genetic, cytological and molecular properties. Highly repeated DNA sequences (satellites) are the principal component of heterochromatin. Using probes from cloned satellites, we have constructed a chromosome map of 10 highly repeated, simple DNA sequences in heterochromatin of mitotic chromosomes of Drosophila melanogaster. Despite extensive sequence homology among some satellites, chromosomal locations could be distinguished by stringent in situ hybridizations for each satellite. Only two of the localizations previously determined using gradient-purified bulk satellite probes are correct. Eight new satellite localizations are presented, providing a megabase-level chromosome map of one-quarter of the genome. Five major satellites each exhibit a multichromosome distribution, and five minor satellites hybridize to single sites on the Y chromosome. Satellites closely related in sequence are often located near one another on the same chromosome. About 80% of Y chromosome DNA is composed of nine simple repeated sequences, in particular (AAGAC)(n) (8 Mb), (AAGAG)(n) (7 Mb) and (AATAT)(n) (6 Mb). Similarly, more than 70% of the DNA in chromosome 2 heterochromatin is composed of five simple repeated sequences. We have also generated a high resolution map of satellites in chromosome 2 heterochromatin, using a series of translocation chromosomes whose breakpoints in heterochromatin were ordered by N-banding. Finally, staining and banding patterns of heterochromatic regions are correlated with the locations of specific repeated DNA sequences. The basis for the cytochemical heterogeneity in banding appears to depend exclusively on the different satellite DNAs present in heterochromatin. PMID:8375654

Social instigation and repeated aggressive confrontations in male Swiss mice: analysis of plasma corticosterone, CRF and BDNF levels in limbic brain areas.

PubMed

Fortes, Paula Madeira; Albrechet-Souza, Lucas; Vasconcelos, Mailton; Ascoli, Bruna Maria; Menegolla, Ana Paula; de Almeida, Rosa Maria M

2017-01-01

Agonistic behaviors help to ensure survival, provide advantage in competition, and communicate social status. The resident-intruder paradigm, an animal model based on male intraspecific confrontations, can be an ethologically relevant tool to investigate the neurobiology of aggressive behavior. To examine behavioral and neurobiological mechanisms of aggressive behavior in male Swiss mice exposed to repeated confrontations in the resident intruder paradigm. Behavioral analysis was performed in association with measurements of plasma corticosterone of mice repeatedly exposed to a potential rival nearby, but inaccessible (social instigation), or to 10 sessions of social instigation followed by direct aggressive encounters. Moreover, corticotropin-releasing factor (CRF) and brain-derived neurotrophic factor (BNDF) were measured in the brain of these animals. Control mice were exposed to neither social instigation nor aggressive confrontations. Mice exposed to aggressive confrontations exhibited a similar pattern of species-typical aggressive and non-aggressive behaviors on the first and the last session. Moreover, in contrast to social instigation only, repeated aggressive confrontations promoted an increase in plasma corticosterone. After 10 aggressive confrontation sessions, mice presented a non-significant trend toward reducing hippocampal levels of CRF, which inversely correlated with plasma corticosterone levels. Conversely, repeated sessions of social instigation or aggressive confrontation did not alter BDNF concentrations at the prefrontal cortex and hippocampus. Exposure to repeated episodes of aggressive encounters did not promote habituation over time. Additionally, CRF seems to be involved in physiological responses to social stressors.

Slide-and-exchange mechanism for rapid and selective transport through the nuclear pore complex.

PubMed

Raveh, Barak; Karp, Jerome M; Sparks, Samuel; Dutta, Kaushik; Rout, Michael P; Sali, Andrej; Cowburn, David

2016-05-03

Nucleocytoplasmic transport is mediated by the interaction of transport factors (TFs) with disordered phenylalanine-glycine (FG) repeats that fill the central channel of the nuclear pore complex (NPC). However, the mechanism by which TFs rapidly diffuse through multiple FG repeats without compromising NPC selectivity is not yet fully understood. In this study, we build on our recent NMR investigations showing that FG repeats are highly dynamic, flexible, and rapidly exchanging among TF interaction sites. We use unbiased long timescale all-atom simulations on the Anton supercomputer, combined with extensive enhanced sampling simulations and NMR experiments, to characterize the thermodynamic and kinetic properties of FG repeats and their interaction with a model transport factor. Both the simulations and experimental data indicate that FG repeats are highly dynamic random coils, lack intrachain interactions, and exhibit significant entropically driven resistance to spatial confinement. We show that the FG motifs reversibly slide in and out of multiple TF interaction sites, transitioning rapidly between a strongly interacting state and a weakly interacting state, rather than undergoing a much slower transition between strongly interacting and completely noninteracting (unbound) states. In the weakly interacting state, FG motifs can be more easily displaced by other competing FG motifs, providing a simple mechanism for rapid exchange of TF/FG motif contacts during transport. This slide-and-exchange mechanism highlights the direct role of the disorder within FG repeats in nucleocytoplasmic transport, and resolves the apparent conflict between the selectivity and speed of transport.

Improved Bi Film Wrapped Single Walled Carbon Nanotubes for Ultrasensitive Electrochemical Detection of Trace Cr(VI).

PubMed

Ouyang, Ruizhuo; Zhang, Wangyao; Zhou, Shilin; Xue, Zi-Ling; Xu, Lina; Gu, Yingying; Miao, Yuqing

2013-12-15

We report here the successful fabrication of an improved Bi film wrapped single walled carbon nanotubes modified glassy carbon electrode (Bi/SWNTs/GCE) as a highly sensitive platform for ultratrace Cr(VI) detection through catalytic adsorptive cathodic stripping voltammetry (AdCSV). The introduction of negatively charged SWNTs extraordinarily decreased the size of Bi particles to nanoscale due to electrostatic interaction which made Bi(III) cations easily attracted onto the surface of SWNTs in good order, leading to higher quality of Bi film deposition. The obtained Bi/SWNTs composite was well characterized with electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), the static water contact angle and the voltammetric measurements. The results demonstrates the improvements in the quality of Bi film deposited on the surface of SWNTs such as faster speed of electron transfer, more uniform and smoother morphology, better hydrophilicity and higher stripping signal. Using diethylene triaminepentaacetic acid (DTPA) as complexing ligand, the fabricated electrode displays a well-defined and highly sensitive peak for the reduction of Cr(III)-DTPA complex at -1.06 V ( vs . Ag/AgCl) with a linear concentration range of 0-25 nM and a fairly low detection limit of 0.036 nM. No interference was found in the presence of coexisting ions, and good recoveries were achieved for the analysis of a river sample. In comparison to previous approaches using Bi film modified GCE, the newly designed electrode exhibits better reproducibility and repeatability towards aqueous detection of trace Cr(VI) and appears to be very promising as the basis of a highly sensitive and selective voltammetric procedure for Cr(VI) detection at trace level in real samples.

Improved Bi Film Wrapped Single Walled Carbon Nanotubes for Ultrasensitive Electrochemical Detection of Trace Cr(VI)

PubMed Central

Zhou, Shilin; Xue, Zi-Ling; Xu, Lina; Gu, Yingying; Miao, Yuqing

2014-01-01

We report here the successful fabrication of an improved Bi film wrapped single walled carbon nanotubes modified glassy carbon electrode (Bi/SWNTs/GCE) as a highly sensitive platform for ultratrace Cr(VI) detection through catalytic adsorptive cathodic stripping voltammetry (AdCSV). The introduction of negatively charged SWNTs extraordinarily decreased the size of Bi particles to nanoscale due to electrostatic interaction which made Bi(III) cations easily attracted onto the surface of SWNTs in good order, leading to higher quality of Bi film deposition. The obtained Bi/SWNTs composite was well characterized with electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), the static water contact angle and the voltammetric measurements. The results demonstrates the improvements in the quality of Bi film deposited on the surface of SWNTs such as faster speed of electron transfer, more uniform and smoother morphology, better hydrophilicity and higher stripping signal. Using diethylene triaminepentaacetic acid (DTPA) as complexing ligand, the fabricated electrode displays a well-defined and highly sensitive peak for the reduction of Cr(III)-DTPA complex at −1.06 V (vs. Ag/AgCl) with a linear concentration range of 0–25 nM and a fairly low detection limit of 0.036 nM. No interference was found in the presence of coexisting ions, and good recoveries were achieved for the analysis of a river sample. In comparison to previous approaches using Bi film modified GCE, the newly designed electrode exhibits better reproducibility and repeatability towards aqueous detection of trace Cr(VI) and appears to be very promising as the basis of a highly sensitive and selective voltammetric procedure for Cr(VI) detection at trace level in real samples. PMID:24771881

Ares I-X Flight Test Validation of Control Design Tools in the Frequency-Domain

NASA Technical Reports Server (NTRS)

Johnson, Matthew; Hannan, Mike; Brandon, Jay; Derry, Stephen

2011-01-01

A major motivation of the Ares I-X flight test program was to Design for Data, in order to maximize the usefulness of the data recorded in support of Ares I modeling and validation of design and analysis tools. The Design for Data effort was intended to enable good post-flight characterizations of the flight control system, the vehicle structural dynamics, and also the aerodynamic characteristics of the vehicle. To extract the necessary data from the system during flight, a set of small predetermined Programmed Test Inputs (PTIs) was injected directly into the TVC signal. These PTIs were designed to excite the necessary vehicle dynamics while exhibiting a minimal impact on loads. The method is similar to common approaches in aircraft flight test programs, but with unique launch vehicle challenges due to rapidly changing states, short duration of flight, a tight flight envelope, and an inability to repeat any test. This paper documents the validation effort of the stability analysis tools to the flight data which was performed by comparing the post-flight calculated frequency response of the vehicle to the frequency response calculated by the stability analysis tools used to design and analyze the preflight models during the control design effort. The comparison between flight day frequency response and stability tool analysis for flight of the simulated vehicle shows good agreement and provides a high level of confidence in the stability analysis tools for use in any future program. This is true for both a nominal model as well as for dispersed analysis, which shows that the flight day frequency response is enveloped by the vehicle s preflight uncertainty models.

Optical performance of multifocal soft contact lenses via a single-pass method.

PubMed

Bakaraju, Ravi C; Ehrmann, Klaus; Falk, Darrin; Ho, Arthur; Papas, Eric

2012-08-01

A physical model eye capable of carrying soft contact lenses (CLs) was used as a platform to evaluate optical performance of several commercial multifocals (MFCLs) with high- and low-add powers and a single-vision control. Optical performance was evaluated at three pupil sizes, six target vergences, and five CL-correcting positions using a spatially filtered monochromatic (632.8 nm) light source. The various target vergences were achieved by using negative trial lenses. A photosensor in the retinal plane recorded the image point-spread that enabled the computation of visual Strehl ratios. The centration of CLs was monitored by an additional integrated en face camera. Hydration of the correcting lens was maintained using a humidity chamber and repeated instillations of rewetting saline drops. All the MFCLs reduced performance for distance but considerably improved performance along the range of distance to near target vergences, relative to the single-vision CL. Performance was dependent on add power, design, pupil, and centration of the correcting CLs. Proclear (D) design produced good performance for intermediate vision, whereas Proclear (N) design performed well at near vision (p < 0.05). AirOptix design exhibited good performance for distance and intermediate vision. PureVision design showed improved performance across the test vergences, but only for pupils ≥4 mm in diameter. Performance of Acuvue bifocal was comparable with other MFCLs, but only for pupils >4 mm in diameter. Acuvue Oasys bifocal produced performance comparable with single-vision CL for most vergences. Direct measurement of single-pass images at the retinal plane of a physical model eye used in conjunction with various MFCLs is demonstrated. This method may have utility in evaluating the relative effectiveness of commercial and prototype designs.

Optimization and application of parallel solid-phase extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry for the determination of 11 aminoglycoside residues in honey and royal jelly.

PubMed

Wang, Xinran; Yang, Shupeng; Li, Yi; Zhang, Jinzhen; Jin, Yue; Zhao, Wen; Zhang, Yongxin; Huang, Jingping; Wang, Peng; Wu, Cuiling; Zhou, Jinhui

2018-03-23

A robust and sensitive method of solid-phase extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was established and performed for the simultaneous determination of eleven aminoglycosides (AGs) in royal jelly and honey. After sample extraction by a phosphate buffer containing trichloroacetic acid (TCA) and ethylenediaminetetracetic acid disodium salt (Na 2 EDTA), the extraction solution was subjected to a parallel solid-phase extraction for clean-up prior to the LC-MS/MS analysis. The same method was applied to analyze two completely different matrices, honey and royal jelly. Good sensitivity, repeatability, and recovery were obtained by using the mobile phase without an ion-pairing reagent such as heptafluorobutyric acid (HFBA) or sodium heptanesulfonate. The calibration curves of the honey and royal jelly samples exhibited a good linear response (R 2  > 0.99) at six concentrations in the range of 10-1000 μg/mL. The limit of quantification (LOQ) of the AGs ranged from 10 to 25 μg/kg in the honey and from 12.5 to 25 μg/kg in the royal jelly. The recoveries of the AGs for the honey and royal jelly samples were in the range of 79.48% to 108.95% and 74.61% to 113.70% respectively and the relative standard deviations (RSDs) were between 1.23% and 9.59%, and between 1.51% and 9.98%, respectively. The proposed approach has been allowed in China as a reference method for the simultaneous determination of eleven AGs in honey and royal jelly. Copyright © 2018 Elsevier B.V. All rights reserved.

Biomimetic piezoelectric quartz crystal sensor with chloramphenicol-imprinted polymer sensing layer.

PubMed

Ebarvia, Benilda S; Ubando, Isaiah E; Sevilla, Fortunato B

2015-11-01

The measurement of banned antibiotic like chloramphenicol is significant for customer protection and safety. The presence of residual antibiotics in foods and food products of animal origin could pose as health hazards and affect food quality for global acceptance. In this study, the potential of a chloramphenicol sensor based on molecularly imprinted polymer (MIP) coupled with a piezoelectric quartz crystal was explored. The MIP was prepared by precipitation polymerization at 60 °C. Methacrylic acid was used as monomer, trimethylolpropane trimethacrylate (TRIM) as crosslinker, and chloramphenicol as the template. Template removal on the resulting polymer was done by extraction using methanol-acetic acid. Characterization of the MIP and NIP were conducted by spectroscopic and microscopic methods. These further supported the imprinting and rebinding process of chloramphenicol to the polymer matrix. The chloramphenicol sensor was devised by spin-coating onto one side of the 10 MHz AT-cut quartz crystal the MIP suspension in polyvinylchloride-tetrahydrofuran (6:2:1 w/w/v) solution. Optimization of sensor response was performed by varying the type of cross-linker, amount of MIP sensing layer, curing time, and pH. The sensor exhibited good sensitivity of about 73 Hz/log (conc., µg mL(-1)) and good repeatability (rsd<10%). A linear relationship (r(2)=0.9901) between frequency shift and chloramphenicol concentration in the range of 1×10(-6) up to 1×10(-1) µg/mL was obtained. The sensor response was highly selective to chloramphenicol than with other compounds of similar chemical structures. Acceptable percent recovery was obtained for real sample analysis using the sensor. The proposed sensor could be a promising low cost and highly sensitive approach for residual chloramphenicol quantification in food products. Copyright © 2015 Elsevier B.V. All rights reserved.

Interpreting long-term trends in Blue Mountain ecosystems from repeat photography.

Treesearch

Jon M. Skovlin; Jack Ward Thomas

1995-01-01

Photographs taken before 1925 were compared with photos taken as recently as 1992 to interpret changes within ecosystems in the Blue Mountains of Oregon. For discussion purposes, 10 ecosystems were aggregated into seven broad landscape systems. Nearly all systems exhibited some degree of conversion from herbaceous to woody forms of vegetation. Nonforested ecosystems...

Evidence for the role of an invasive weed in widespread occurrence of phytoplasmal diseases in diverse vegetable crops: implications from lineage-specific molecular markers

USDA-ARS?s Scientific Manuscript database

During the period from 2011 to 2013, several plant diseases repeatedly occurred in vegetable crops grown in Yuanmou County, Yunnan Province, China. Affected plants included cowpea, sword bean, string bean, tomato, lettuce, and water spinach. The diseased plants exhibited symptoms of witches’-broom...

Buyers and Borrowers: The Application of Consumer Theory to the Study of Library Use.

ERIC Educational Resources Information Center

Emery, Charles D.

Using Ehrenberg's application of mathematical models to the analysis and prediction of repeated buying patterns of consumers, this study focuses on the concept of library use as a form of consumer behavior. The following hypotheses were tested: designated library user groups will tend to exhibit stable behavioral patterns with respect to the…

Direct and Distal Effects of Noncontingent Juice on Rumination Exhibited by a Child with Autism

ERIC Educational Resources Information Center

Kliebert, Megan L.; Tiger, Jeffrey H.

2011-01-01

Previous research has demonstrated the efficacy of the noncontingent delivery of foods and liquids at suppressing rumination, the repeated regurgitation and rechewing of partially digested food. However, it is unclear how long this reduction is maintained after caregivers terminate this procedure. The current study examined the direct and distal…

Complete Genome Sequences of Four Isolates of Plutella xylostella Granulovirus.

PubMed

Spence, Robert J; Noune, Christopher; Hauxwell, Caroline

2016-06-30

Granuloviruses are widespread pathogens of Plutella xylostella L. (diamondback moth) and potential biopesticides for control of this global insect pest. We report the complete genomes of four Plutella xylostella granulovirus isolates from China, Malaysia, and Taiwan exhibiting pairs of noncoding, homologous repeat regions with significant sequence variation but equivalent length. Copyright © 2016 Spence et al.

Laser Doppler imager (LDI) scanner and intradermal injection for in vivo pharmacology in human skin microcirculation: responses to acetylcholine, endothelin-1 and their repeatability

PubMed Central

Saez, Anabelle M Opazo; Mosel, Frank; Nürnberger, Jens; Rushentsova, U; Gössl, Mario; Mitchell, Anna; Schäfers, Rafael F; Philipp, Thomas; Wenzel, René R

2005-01-01

Aims The purpose of this study was to evaluate the repeatability of forearm skin blood flow responses to intradermal injections of acetylcholine (ACh) and endothelin-1 (ET-1) using a double injection technique (DIT) and a laser Doppler imager (LDI) scanner in the human skin microcirculation. Methods We used a laser Doppler imager (Moor LDI V3.01) to continuously monitor the change in skin blood flow during intradermal administration of physiological saline (0.9% NaCl), acetylcholine (ACh 10−7, 10−8, 10−9 M) and endothelin-1 (ET-1 10−14, 10−16, 10−18 M) in 10 healthy male subjects. Subjects were examined on 3 different days for assessment of interday and interobserver repeatability. Injections of either drug were randomly placed on different sites of the forearm. Laser Doppler images were collected before and after injection at 2.5 min intervals for 30 min. Data were analysed after the completion of each experiment using Moor Software V.3.01. Results are expressed as changes from baseline in arbitrary perfusion units (PU). Results ACh caused a significant vasodilation (P< 0.0001 anova, mean ± SE: 766 ± 152 PU, ACh 10−9 M; 1868 ± 360 PU, ACh 10−8 M; 4188 ± 848 PU, ACh 10−7 M; mean of days 1 and 2, n = 10), and ET-1 induced a significant vasoconstrictive response (P< 0.0001 anova, −421 ± 83 PU, ET-1 10−18 M; −553 ± 66 PU, ET-1 10−16 M; −936 ± 90 PU, ET-1 10−14 M; mean of days 1 and 2, n = 10). There was no difference on the response to either drug on repeated days. Bland-Altman analyses showed a close agreement of responses between days with repeatability coefficients of 1625.4 PU for ACh, and 386.0 PU for ET-1 (95% CI: ACh, −1438 to 1747 PU, ET-1, −399 to 358 PU) and between observers with repeatability coefficients of 1057.2 PU for ACh and 255.8 PU for ET-1 (95% CI: ACh, −1024 to 1048 PU, ET-1, −252 to 249 PU). The variability between these responses was independent of average flux values for both ACh and ET-1. There was a significant correlation between responses measured in the same site, in the same individual on two different days by the same observer (ACh, r = 0.94, P < 0.0001; ET-1, r = 0.90, P < 0.0006), and between responses measured by two different observers (ACh, r = 0.94, P < 0.0001; ET-1, r = 0.91, P < 0.0003). Conclusion We have shown that interday and intraobserver responses to intradermal injections of ET-1 and ACh, assessed using the DIT in combination with an LDI scanner, exhibited good reproducibility and may be a useful tool for studying the skin microcirculation in vivo. PMID:15842548

A rhodamine-based fluorescent probe for colorimetric and fluorescence lighting-up determination of toxic thiophenols in environmental water and living cells.

PubMed

Wu, Juanjuan; Ye, Zhuo; Wu, Feng; Wang, Hongying; Zeng, Lintao; Bao, Guang-Ming

2018-05-01

Thiophenols are a class of highly toxic environmental pollutant, hence it is very necessary to monitor thiophenols in environment and living cells with an efficient and reliable method. Herein, a novel fluorescent probe for thiophenols has been developed, which exhibited a colorimetric and fluorescence turn-on dual response towards thiophenols with good selectivity and fast response. The sensing mechanism for thiophenols was attributed to nucleophilic substitution reaction, which was confirmed by HPLC. The probe exhibited good recovery (from 90% to 107%) and low limit of detection for thiophenols (37nM) in industrial wastewater. Moreover, the probe has been successfully employed to visualize thiophenol in living cells. Therefore, the fluorescent probe has good capability for monitoring thiophenols in environmental samples and biological systems. Copyright © 2018 Elsevier B.V. All rights reserved.

Highly stable aluminum-based metal-organic frameworks as biosensing platforms for assessment of food safety.

PubMed

Liu, Chun-Sen; Sun, Chun-Xiao; Tian, Jia-Yue; Wang, Zhuo-Wei; Ji, Hong-Fei; Song, Ying-Pan; Zhang, Shuai; Zhang, Zhi-Hong; He, Ling-Hao; Du, Miao

2017-05-15

Two unique immunosensors made of aluminum-based metal-organic frameworks (MOFs), namely, 515- and 516-MOFs, with 4,4',4''-nitrilotribenzoic acid (H 3 NTB) were successfully obtained to efficiently assess food safety. The as-prepared 515- and 516-MOFs exhibited superior thermal and physicochemical stability, high electrochemical activity, and good biocompatibility. Among these immunosensors, 516-MOF showed a preferable biosensing ability toward analytes determined by electrochemical techniques. The developed 516-MOF-based electrochemical biosensor not only demonstrated high sensitivity with low detection limits of 0.70 and 0.40pgmL -1 toward vomitoxin and salbutamol, respectively, but also showed good selectivity in the presence of other interferences. Therefore, with the advantages of high sensitivity, good selectivity, and simple operation, this new strategy is believed to exhibit great potential for simple and convenient detection of poisonous and harmful residues in food. Copyright © 2017 Elsevier B.V. All rights reserved.

Reliability of Corneal Dynamic Scheimpflug Analyser Measurements in Virgin and Post-PRK Eyes

PubMed Central

Chen, Xiangjun; Stojanovic, Aleksandar; Hua, Yanjun; Eidet, Jon Roger; Hu, Di; Wang, Jingting; Utheim, Tor Paaske

2014-01-01

Purpose To determine the measurement reliability of CorVis ST, a dynamic Scheimpflug analyser, in virgin and post-photorefractive keratectomy (PRK) eyes and compare the results between these two groups. Methods Forty virgin eyes and 42 post-PRK eyes underwent CorVis ST measurements performed by two technicians. Repeatability was evaluated by comparing three consecutive measurements by technician A. Reproducibility was determined by comparing the first measurement by technician A with one performed by technician B. Intraobserver and interobserver intraclass correlation coefficients (ICCs) were calculated. Univariate analysis of covariance (ANCOVA) was used to compare measured parameters between virgin and post-PRK eyes. Results The intraocular pressure (IOP), central corneal thickness (CCT) and 1st applanation time demonstrated good intraobserver repeatability and interobserver reproducibility (ICC≧0.90) in virgin and post-PRK eyes. The deformation amplitude showed a good or close to good repeatability and reproducibility in both groups (ICC≧0.88). The CCT correlated positively with 1st applanation time (r = 0.437 and 0.483, respectively, p<0.05) and negatively with deformation amplitude (r = −0.384 and −0.375, respectively, p<0.05) in both groups. Compared to post-PRK eyes, virgin eyes showed longer 1st applanation time (7.29±0.21 vs. 6.96±0.17 ms, p<0.05) and lower deformation amplitude (1.06±0.07 vs. 1.17±0.08 mm, p<0.05). Conclusions CorVis ST demonstrated reliable measurements for CCT, IOP, and 1st applanation time, as well as relatively reliable measurement for deformation amplitude in both virgin and post-PRK eyes. There were differences in 1st applanation time and deformation amplitude between virgin and post-PRK eyes, which may reflect corneal biomechanical changes occurring after the surgery in the latter. PMID:25302580

Web-Based Student Art Galleries

ERIC Educational Resources Information Center

Burton, David

2010-01-01

Exhibition is an important part of the artistic process for students as well as professional artists, but finding enough good places to exhibit can be as difficult for student artists as for adult artists. Venues that are accessible, display art attractively, and provide adequate space for many artists are usually in short supply. There is an…

Spectral, thermal, XRD and SEM studies of charge-transfer complexation of hexamethylenediamine and three types of acceptors: π-, σ- and vacant orbital acceptors that include quinol, picric acid, bromine, iodine, SnCl4 and ZnCl2 acceptors

NASA Astrophysics Data System (ADS)

Adam, Abdel Majid A.; Refat, Moamen S.; Saad, Hosam A.

2013-11-01

In this work, structural, thermal, morphological and pharmacological characterization was performed on the interactions between a hexamethylenediamine (HMDA) donor and three types of acceptors to understand the complexation behavior of diamines. The three types of acceptors include π-acceptors (i.e., quinol (QL) and picric acid (PA)), σ-acceptors (i.e., bromine and iodine) and vacant orbital acceptors (i.e., tin(IV) tetrachloride (SnCl4) and zinc chloride (ZnCl2)). The characterization of the obtained CT complexes was performed using elemental analysis, infrared (IR), Raman, 1H NMR and electronic absorption spectroscopy, powder X-ray diffraction (XRD) and thermogravimetric (TG) analysis. Their morphologies were studied using scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX). The biological activities of the obtained CT complexes were tested for their antibacterial activities. The complex containing the QL acceptor exhibited a remarkable electronic spectrum with a strong, broad absorption band, which had an observed λmax that was at a much longer wavelength than those of the free reactants. In addition, this complex exhibited strong antimicrobial activities against various bacterial and fungal strains compared to standard drugs. The complexes containing the PA, iodine, Sn(IV) and Zn(II) acceptors exhibited good thermal stability up to 240, 330, 275 and 295 °C, respectively. The complexes containing bromine, Sn(IV) and Zn(II) acceptors exhibited good crystallinity. In addition to its good crystallinity properties, the complex containing the bromine acceptor exhibits a remarkable morphology feature.

Viral delivery of C9orf72 hexanucleotide repeat expansions in mice leads to repeat-length-dependent neuropathology and behavioural deficits

PubMed Central

Herranz-Martin, Saul; Lewis, Katherine; Mulcahy, Padraig; Higginbottom, Adrian; Walker, Callum; Valenzuela, Isabel Martinez-Pena y; Coldicott, Ian; Shaw, Pamela J.

2017-01-01

ABSTRACT Intronic GGGGCC repeat expansions in C9orf72 are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Two major pathologies stemming from the hexanucleotide RNA expansions (HREs) have been identified in postmortem tissue: intracellular RNA foci and repeat-associated non-ATG dependent (RAN) dipeptides, although it is unclear how these and other hallmarks of disease contribute to the pathophysiology of neuronal injury. Here, we describe two novel lines of mice that overexpress either 10 pure or 102 interrupted GGGGCC repeats mediated by adeno-associated virus (AAV) and recapitulate the relevant human pathology and disease-related behavioural phenotypes. Similar levels of intracellular RNA foci developed in both lines of mice, but only mice expressing 102 repeats generated C9orf72 RAN pathology, neuromuscular junction (NMJ) abnormalities, dispersal of the hippocampal CA1, enhanced apoptosis, and deficits in gait and cognition. Neither line of mice, however, showed extensive TAR DNA-binding protein 43 (TDP-43) pathology or neurodegeneration. Our data suggest that RNA foci pathology is not a good predictor of C9orf72 RAN dipeptide formation, and that RAN dipeptides and NMJ dysfunction are drivers of C9orf72 disease pathogenesis. These AAV-mediated models of C9orf72-associated ALS/FTD will be useful tools for studying disease pathophysiology and developing new therapeutic approaches. PMID:28550099

The minisatellite of the GPI/AMF/NLK/MF gene: interspecies conservation and transcriptional activity.

PubMed

Williams, R R; Hassan-Walker, A F; Lavender, F L; Morgan, M; Faik, P; Ragoussis, J

2001-05-16

Minisatellites are tandemly repeated DNA sequences found throughout the genomes of all eukaryotes. They are regions often prone to instability and hence hypervariability; thus repeat unit sequence is generally not conserved beyond closely related species. We have studied the minisatellite located in intron 9 of the human glucose phosphate isomerase (GPI) gene (also known as neuroleukin, autocrine motility factor, maturation and differentiation factor) and have found, by Zoo blotting coupled with PCR amplification and DNA sequencing, that similar repeat units are present in seven other species of mammal. There is also evidence for the presence of the minisatellite in chicken. The repeat unit does not appear to be present at any other locus in these genomes. Minisatellite DNA has been reported to be involved in recombination activity, control of gene expression of nearby gene(s) (both transcriptional and translational), whilst others form protein coding regions. The high level of conservation exhibited by the GPI minisatellite, coupled with the unique location, strongly suggests a functional role. Our results from transient and stable transfections using luciferase reporter constructs have shown that the GPI minisatellite region can act to increase transcription from the SV40 promoter, CMV promoter and the human GPI promoter.

Face repetition detection and social interest: An ERP study in adults with and without Williams syndrome.

PubMed

Key, Alexandra P; Dykens, Elisabeth M

2016-12-01

The present study examined possible neural mechanisms underlying increased social interest in persons with Williams syndrome (WS). Visual event-related potentials (ERPs) during passive viewing were used to compare incidental memory traces for repeated vs. single presentations of previously unfamiliar social (faces) and nonsocial (houses) images in 26 adults with WS and 26 typical adults. Results indicated that participants with WS developed familiarity with the repeated faces and houses (frontal N400 response), but only typical adults evidenced the parietal old/new effect (previously associated with stimulus recollection) for the repeated faces. There was also no evidence of exceptional salience of social information in WS, as ERP markers of memory for repeated faces vs. houses were not significantly different. Thus, while persons with WS exhibit behavioral evidence of increased social interest, their processing of social information in the absence of specific instructions may be relatively superficial. The ERP evidence of face repetition detection in WS was independent of IQ and the earlier perceptual differentiation of social vs. nonsocial stimuli. Large individual differences in ERPs of participants with WS may provide valuable information for understanding the WS phenotype and have relevance for educational and treatment purposes.

Prevalence of spinocerebellar ataxia 36 in a US population

PubMed Central

Valera, Juliana M.; Diaz, Tatyana; Petty, Lauren E.; Quintáns, Beatriz; Yáñez, Zuleima; Boerwinkle, Eric; Muzny, Donna; Akhmedov, Dmitry; Berdeaux, Rebecca; Sobrido, Maria J.; Gibbs, Richard; Lupski, James R.; Geschwind, Daniel H.; Perlman, Susan; Below, Jennifer E.

2017-01-01

Objective: To assess the prevalence and clinical features of individuals affected by spinocerebellar ataxia 36 (SCA36) at a large tertiary referral center in the United States. Methods: A total of 577 patients with undiagnosed sporadic or familial cerebellar ataxia comprehensively evaluated at a tertiary referral ataxia center were molecularly evaluated for SCA36. Repeat primed PCR and fragment analysis were used to screen for the presence of a repeat expansion in the NOP56 gene. Results: Fragment analysis of triplet repeat primed PCR products identified a GGCCTG hexanucleotide repeat expansion in intron 1 of NOP56 in 4 index cases. These 4 SCA36-positive families comprised 2 distinct ethnic groups: white (European) (2) and Asian (Japanese [1] and Vietnamese [1]). Individuals affected by SCA36 exhibited typical clinical features with gait ataxia and age at onset ranging between 35 and 50 years. Patients also suffered from ataxic or spastic limbs, altered reflexes, abnormal ocular movement, and cognitive impairment. Conclusions: In a US population, SCA36 was observed to be a rare disorder, accounting for 0.7% (4/577 index cases) of disease in a large undiagnosed ataxia cohort. PMID:28761930

Impact of Eccentricity on East-west Stationkeeping for GPS Class of Orbits

NASA Technical Reports Server (NTRS)

Ely, Todd A.

1999-01-01

There exists a strong relationship between eccentricity and the potential for a repeating groundtrack orbit to exhibit chaotic motion. This is true at all values of eccentricity, but, perhaps most dramatic, is that it is true even for orbits that are nearly circular. These complex motions can have a significant impact on the east-west stationkeeping process for maintaining the repeating groundtrack property of a commensurate orbit. Ely and Howell have shown that traditional stationkeeping (SK) methods are unable to maintain a repeating groundtrack in the presence of complex dynamics, such as with chaotic motion. They developed an alternate SK method that is able to maintain a repeating groundtrack for eccentric, commensurate orbits. The focus of the current study is to investigate orbits with characteristics that are similar to GPS satellites except with modestly larger eccentricities. It will be shown that at eccentricities larger than approx. .01 the chaotic regions become significant, and the need arises for a robust stationkeeping approach, such as developed in. FurtheRmore, the investigation will reveal that the influence of luni-solar perturbations contributes to the growth of eccentricity, thus increasing the probability of encountering chaotic motion during a typical satellite lifetime.

Is mammalian chromosomal evolution driven by regions of genome fragility?

PubMed Central

Ruiz-Herrera, Aurora; Castresana, Jose; Robinson, Terence J

2006-01-01

Background A fundamental question in comparative genomics concerns the identification of mechanisms that underpin chromosomal change. In an attempt to shed light on the dynamics of mammalian genome evolution, we analyzed the distribution of syntenic blocks, evolutionary breakpoint regions, and evolutionary breakpoints taken from public databases available for seven eutherian species (mouse, rat, cattle, dog, pig, cat, and horse) and the chicken, and examined these for correspondence with human fragile sites and tandem repeats. Results Our results confirm previous investigations that showed the presence of chromosomal regions in the human genome that have been repeatedly used as illustrated by a high breakpoint accumulation in certain chromosomes and chromosomal bands. We show, however, that there is a striking correspondence between fragile site location, the positions of evolutionary breakpoints, and the distribution of tandem repeats throughout the human genome, which similarly reflect a non-uniform pattern of occurrence. Conclusion These observations provide further evidence that certain chromosomal regions in the human genome have been repeatedly used in the evolutionary process. As a consequence, the genome is a composite of fragile regions prone to reorganization that have been conserved in different lineages, and genomic tracts that do not exhibit the same levels of evolutionary plasticity. PMID:17156441

Assessing Diversity of DNA Structure-Related Sequence Features in Prokaryotic Genomes

PubMed Central

Huang, Yongjie; Mrázek, Jan

2014-01-01

Prokaryotic genomes are diverse in terms of their nucleotide and oligonucleotide composition as well as presence of various sequence features that can affect physical properties of the DNA molecule. We present a survey of local sequence patterns which have a potential to promote non-canonical DNA conformations (i.e. different from standard B-DNA double helix) and interpret the results in terms of relationships with organisms' habitats, phylogenetic classifications, and other characteristics. Our present work differs from earlier similar surveys not only by investigating a wider range of sequence patterns in a large number of genomes but also by using a more realistic null model to assess significant deviations. Our results show that simple sequence repeats and Z-DNA-promoting patterns are generally suppressed in prokaryotic genomes, whereas palindromes and inverted repeats are over-represented. Representation of patterns that promote Z-DNA and intrinsic DNA curvature increases with increasing optimal growth temperature (OGT), and decreases with increasing oxygen requirement. Additionally, representations of close direct repeats, palindromes and inverted repeats exhibit clear negative trends with increasing OGT. The observed relationships with environmental characteristics, particularly OGT, suggest possible evolutionary scenarios of structural adaptation of DNA to particular environmental niches. PMID:24408877

The VNTR 2 repeat in MAOA and delinquent behavior in adolescence and young adulthood: associations and MAOA promoter activity

PubMed Central

Guo, Guang; Ou, Xiao-Ming; Roettger, Michael; Shih, Jean C

2010-01-01

Genetic studies of delinquent and criminal behavior are rare in spite of the wide recognition that individuals may differ in their propensity for delinquency and criminality. Using 2524 participants in Add Health in the United States, the present study demonstrates a link between the rare 2 repeat of the 30-bp VNTR in the MAOA gene and much higher levels of self-reported serious and violent delinquency. The evidence is based on a statistical association analysis and a functional analysis of MAOA promoter activity using two human brain-derived cell lines: neuroblastoma SH-SY5Y and human glioblastoma 1242-MG. The association analysis shows that men with a 2R report a level of serious delinquency and violent delinquency in adolescence and young adulthood that were about twice (CI: (0.21, 3.24), P = 0.025; and CI: (0.37, 2.5), P = 0.008 for serious and violent delinquency, respectively) as high as those for participants with the other variants. The results for women are similar, but weaker. In the functional analysis, the 2 repeat exhibits much lower levels of promoter activity than the 3 or 4 repeat. PMID:18212819

Reconditioning perovskite films in vapor environments through repeated cation doping

NASA Astrophysics Data System (ADS)

Boonthum, Chirapa; Pinsuwan, Kusuma; Ponchai, Jitprabhat; Srikhirin, Toemsak; Kanjanaboos, Pongsakorn

2018-06-01

Perovskites have attracted considerable attention for application as high-efficiency photovoltaic devices owing to their low-cost and low-temperature fabrication. A good surface and high crystallinity are necessary for high-performance devices. We examine the negative effects of chemical ambiences on the perovskite crystal formation and morphology. The repeated cation doping (RCD) technique was developed to remedy these issues by gradually dropping methylammonium ions on top of about-to-form perovskite surfaces to cause recrystallization. RCD promotes pinhole-free, compact, and polygonal-like surfaces under various vapor conditions. Furthermore, it enhances the electronic properties and crystallization. The benefits of RCD extend beyond perovskites under vapor ambiences, as it can improve regular and wasted perovskites.

Realizing Crack Diagnosing and Self‐Healing by Electricity with a Dynamic Crosslinked Flexible Polyurethane Composite

PubMed Central

Pu, Wuli; Fu, Daihua; Wang, Zhanhua; Gan, Xinpeng; Lu, Xili; Yang, Li

2018-01-01

Abstract Combining self‐healing functions with damage diagnosing, which can achieve timely healing autonomously, is expected to improve the reliability and reduce life cycle cost of materials. Here, a flexible conductive composite composed of a dynamically crosslinked polyurethane bearing Diels–Alder bonds (PUDA) and carbon nanotubes (CNTs), which possess both crack diagnosing and self‐healing functions, is reported. The introduced dynamic Diels–Alder bonds endow the materials self‐healing function and the powder‐based preparation route based on the specially designed CNTs‐coated PUDA micropowders leads to the formation of segregated CNTs network, which makes the composite possess excellent mechanical properties and high conductivity. Because of the sufficient electrothermal and photothermal effect of CNTs, the composites can be healed rapidly and repeatedly by electricity or near‐infrared light based on the retro‐Diels–Alder reaction. An obvious color difference in the infrared thermograph resulting from the resistance difference between damaged and undamaged area can be observed when applying the voltage, which can be used for crack diagnosing. Using the same electrical circuit, the crack in the PUDA/CNTs composite can be noninvasively detected first and then be autonomously healed. The composites also exhibit a strain‐sensing function with good sensitivity and high reliability, thus will have potential applications in electronic strain sensors. PMID:29876226

van der Waals epitaxial two-dimensional CdSxSe(1-x) semiconductor alloys with tunable-composition and application to flexible optoelectronics.

PubMed

Xia, Jing; Zhao, Yun-Xuan; Wang, Lei; Li, Xuan-Ze; Gu, Yi-Yi; Cheng, Hua-Qiu; Meng, Xiang-Min

2017-09-21

Despite the substantial progress in the development of two-dimensional (2D) materials from conventional layered crystals, it still remains particularly challenging to produce high-quality 2D non-layered semiconductor alloys which may bring in some unique properties and new functions. In this work, the synthesis of well-oriented 2D non-layered CdS x Se (1-x) semiconductor alloy flakes with tunable compositions and optical properties is established. Structural analysis reveals that the 2D non-layered alloys follow an incommensurate van der Waals epitaxial growth pattern. Photoluminescence measurements show that the 2D alloys have composition-dependent direct bandgaps with the emission peak varying from 1.8 eV to 2.3 eV, coinciding well with the density functional theory calculations. Furthermore, photodetectors based on the CdS x Se (1-x) flakes exhibit a high photoresponsivity of 703 A W -1 with an external quantum efficiency of 1.94 × 10 3 and a response time of 39 ms. Flexible devices fabricated on a thin mica substrate display good mechanical stability upon repeated bending. This work suggests a facile and general method to produce high-quality 2D non-layered semiconductor alloys for next-generation optoelectronic devices.

Development of a polymeric ionic liquid coating for direct-immersion solid-phase microextraction using polyhedral oligomeric silsesquioxane as cross-linker.

PubMed

Chen, Chunyan; Liang, Xiaotong; Wang, Jianping; Zou, Ying; Hu, Huiping; Cai, Qingyun; Yao, Shouzhuo

2014-06-27

A novel solid-phase microextraction (SPME) fiber was developed by chemical binding of a crosslinked polymeric ionic liquid (PIL) on the surface of an anodized Ti wire, and was applied in direct-immersion mode for the extraction of perfluorinated compounds (PFCs) from water samples coupled with high performance liquid chromatography-tandem mass spectrometry analysis. The PIL coatings were synthesized by using 1-vinyl-3-hexylimidazolium hexafluorophosphate as monomer and methylacryloyl-substituted polyhedral oligomeric silsesquioxane (POSS) as cross-linker via free radical reaction. The proposed fiber coating exhibited high mechanical stability due to the chemical bonding between the coating and the Ti wire surface. The integration of POSS reagent enhanced the organic solvent resistance of the coating. The parameters affecting the extraction performance of the fiber coating including extraction time, pH of solution, ionic strength and desorption conditions were optimized. The developed PIL-POSS fiber showed good linearity (R<0.998) between 0.1 and 50ngmL(-1) with method detection limits ranging from 0.005 to 0.08ngmL(-1) depending on the analyte, and with relative standard deviation for single-fiber repeatability and fiber-to-fiber reproducibility less than 8.6% and 9.5%, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

Sensitive detection of maltose and glucose based on dual enzyme-displayed bacteria electrochemical biosensor.

PubMed

Liu, Aihua; Lang, Qiaolin; Liang, Bo; Shi, Jianguo

2017-01-15

Glucoamylase-displayed bacteria (GA-bacteria) and glucose dehydrogenase-displayed bacteria (GDH-bacteria) were co-immobilized on multi-walled carbon nanotubes (MWNTs) modified glassy carbon electrode (GCE) to construct GA-bacteria/GDH-bacteria/MWNTs/GCE biosensor. The biosensor was developed by optimizing the loading amount and the ratio of GA-bacteria to GDH-bacteria. The as-prepared biosensor exhibited a wide dynamic range of 0.2-10mM and a low detection limit of 0.1mM maltose (S/N=3). The biosensor also had a linear response to glucose in the range of 0.1-2.0mM and a low detection limit of 0.04mM glucose (S/N=3). Interestingly, at the same concentration, glucose was 3.75-fold sensitive than that of maltose at the proposed biosensor. No interferences were observed for other possible mono- and disaccharides. The biosensor also demonstrated good long-term storage stability and repeatability. Further, using both GDH-bacteria/MWNTs/GCE biosensor and GA-bacteria/GDH-bacteria/MWNTs/GCE biosensor, glucose and maltose in real samples can be detected. Therefore, the proposed biosensor is capable of monitoring the food manufacturing and fermentation process. Copyright © 2016 Elsevier B.V. All rights reserved.

Detection of pseudorabies virus by duplex droplet digital PCR assay.

PubMed

Ren, Meishen; Lin, Hua; Chen, Shijie; Yang, Miao; An, Wei; Wang, Yin; Xue, Changhua; Sun, Yinjie; Yan, Yubao; Hu, Juan

2018-01-01

Aujeszky's disease, caused by pseudorabies virus (PRV), has damaged the economy of the Chinese swine industry. A large number of PRV gene-deleted vaccines have been constructed based on deletion of the glycoprotein E ( gE) gene combined with other virulence-related gene deletions, such as thymidine kinase ( TK), whereas PRV wild-type strains contain an intact gE gene. We developed a sensitive duplex droplet digital PCR (ddPCR) assay to rapidly detect PRV wild-type isolates and gE gene-deleted viral vaccines. We compared this assay with a TaqMan real-time PCR (qPCR) using the same primers and probes. Both assays exhibited good linearity and repeatability; however, ddPCR maintained linearity at extremely low concentrations, whereas qPCR did not. Based on positive results for both gE and gB, the detection limit of ddPCR was found to be 4.75 copies/µL in contrast of 76 copies/µL for qPCR, showing that ddPCR provided a 16-fold improvement in sensitivity. In addition, no nonspecific amplification was shown in specificity testing, and the PRV wild-type was distinguished from a gE-deleted strain. The ddPCR was more sensitive when analyzing clinical serum samples. Thus, ddPCR may become an appropriate detection platform for PRV.

Fabrication of Highly Sensitive Nonenzymatic Electrochemical H₂O₂ Sensor Based on Pt Nanoparticles Anchored Reduced Graphene Oxide.

PubMed

Dhara, Keerthy; Ramachandran, T; Nair, Bipin G; Babu, T G Satheesh

2018-06-01

A highly sensitive nonenzymatic hydrogen peroxide (H2O2) sensor was fabricated using platinum nanoparticles decorated reduced graphene oxide (Pt/rGO) nanocomposite. The Pt/rGO nanocomposite was prepared by single-step chemical reduction method. Nanocomposite was characterized by various analytical techniques including Raman spectroscopy, X-ray diffraction, field emission scanning electron microscope and high-resolution transmission electron microscopy. Screen printed electrodes (SPEs) were fabricated and the nanocomposite was cast on the working area of the SPE. Cyclic voltammetry and amperometry demonstrated that the Pt/rGO/SPE displayed much higher electrocatalytic activity towards the reduction of H2O2 than the other modified electrodes. The sensor exhibited wide linear detection range (from 10 μM to 8 mM), very high sensitivity of 1848 μA mM-1 cm-2 and a lower limit of detection of 0.06 μM. The excellent performance of Pt/rGO/SPE sensor were attributed to the reduced graphene oxide being used as an effective matrix to load a number of Pt nanoparticles and the synergistic amplification effect of the two kinds of nanomaterials. Moreover, the sensor showed remarkable features such as good reproducibility, repeatability, long-term stability, and selectivity.

Silica-based ionogels: nanoconfined ionic liquid-rich fibers for headspace solid-phase microextraction coupled with gas chromatography-barrier discharge ionization detection.

PubMed

Pena-Pereira, Francisco; Marcinkowski, Lukasz; Kloskowski, Adam; Namieśnik, Jacek

2014-12-02

In this work, hybrid silica-based materials with immobilized ionic liquids (ILs) were prepared by sol-gel technology and evaluated as solid-phase microextraction (SPME) fiber coatings. High loadings of the IL 1-methyl-3-butylimidazolium bis(trifluoromethylsulfonyl)imide ([C4MIM][TFSI]) were confined within the hybrid network. Coatings composition and morphology were evaluated using scanning electron microscopy and energy dispersive X-ray spectrometry. The obtained ionogel SPME fibers exhibited high extractability for aromatic volatile compounds, yielding good sensitivity and precision when combined with a gas chromatograph with barrier ionization discharge (GC-BID) detection. A central composite design was used for assessing the effect of experimental parameters on the extraction process. Under optimized conditions, the proposed ionogel SPME fiber coatings enabled the achievement of excellent enrichment factors (up to 7400). The limits of detection (LODs) were found in the range 0.03-1.27 μg L(-1), whereas the repeatability and fiber-to-fiber reproducibility were 5.6% and 12.0% on average, respectively. Water samples were analyzed by the proposed methodology, showing recovery values in the range of 88.7-113.9%. The results obtained in this work suggest that ionogels can be promising coating materials for future applications of SPME and related sample preparation techniques.

Study on immobilization of yeast alcohol dehydrogenase on nanocrystalline Ni-Co ferrites as magnetic support.

PubMed

Shakir, Mohammad; Nasir, Zeba; Khan, Mohd Shoeb; Lutfullah; Alam, Md Fazle; Younus, Hina; Al-Resayes, Saud Ibrahim

2015-01-01

The covalent binding of yeast alcohol dehydrogenase (YADH) enzyme complex in a series of magnetic crystalline Ni-Co nanoferrites, synthesized via sol-gel auto combustion technique was investigated. The structural analysis, morphology and magnetic properties of Ni-Co nanoferrites were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), vibrating-sample magnetometer (VSM), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR). The comparative analysis of the HRTEM micrographs of bare magnetic nanoferrite particles and particles immobilized with enzyme revealed an uniform distribution of the particles in both the cases without undergoing change in the size which was found to be in the range 20-30 nm. The binding of YADH to Ni-Co nanoferrites and the possible binding mechanism have been suggested by comparing the FTIR results. The binding properties of the immobilized YADH enzyme were also studied by kinetic parameters, optimum operational pH, temperature, thermal stability and reusability. The immobilized YADH exhibits enhanced thermal stability as compared to the free enzyme over a wide range of temperature and pH, and showed good durability after recovery by magnetic separation for repeated use. Copyright © 2014 Elsevier B.V. All rights reserved.

Simultaneous characterization and quantification of 17 main compounds in Rabdosia rubescens by high performance liquid chromatography.

PubMed

Guo, Sen; Cui, Xueqin; Jiang, Mi; Bai, Lu; Tian, Xiao; Guo, Tiantian; Liu, Qingchao; Zhang, Li; Ho, Chi-Tang; Bai, Naisheng

2017-04-01

Rabdosia rubescens is a healthy herbal tea and well-known Chinese medicinal herb. To evaluate the quality of R. rubescens from China, a high performance liquid chromatography method with dual-wavelength detection was developed and validated. The method was successfully applied for the simultaneous characterization and quantification of 17 main constituents from four different cultivation regions in China. Under optimal conditions, analysis was performed on a Luna C-18 column and gradient elution with a solvent system of acetonitrile and 0.5% (v/v) acetic acid-water at a flow rate of 1.0 mL/min and wavelength of 220 nm and 280 nm. All standard calibration curves exhibited good linearity (r 2  > 0.9992) within the test ranges. The precision was evaluated by intraday and interday tests, which revealed relative standard deviation values within the ranges of 0.57-2.35% and 0.52-3.40%, respectively. The recoveries were in the range of 96.37-101.66%. The relative standard deviation values for stability and repeatability were < 5%. The contents of some compounds were low and varied with different cultivars. The proposed method could serve as a prerequisite for quality control of R. rubescens materials and products. Copyright © 2016. Published by Elsevier B.V.

Green synthesized gold nanoparticles decorated graphene oxide for sensitive determination of chloramphenicol in milk, powdered milk, honey and eye drops.

PubMed

Karthik, R; Govindasamy, Mani; Chen, Shen-Ming; Mani, Veerappan; Lou, Bih-Show; Devasenathipathy, Rajkumar; Hou, Yu-Shen; Elangovan, A

2016-08-01

A simple and rapid green synthesis using Bischofia javanica Blume leaves as reducing agent was developed for the preparation of gold nanoparticles (AuNPs). AuNPs decorated graphene oxide (AuNPs/GO) was prepared and employed for the sensitive amperometric determination of chloramphenicol. The green biosynthesis requires less than 40s to reduce gold salts to AuNPs. The formations of AuNPs and AuNPs/GO were evaluated by scanning electron and atomic force microscopies, UV-Visible and energy dispersive X-ray spectroscopies, X-ray diffraction studies, and electrochemical methods. AuNPs/GO composite film modified electrode was fabricated and shown excellent electrocatalytic ability towards chloramphenicol. Under optimal conditions, the amperometric sensing platform has delivered wide linear range of 1.5-2.95μM, low detection limit of 0.25μM and high sensitivity of 3.81μAμM(-1)cm(-2). The developed sensor exhibited good repeatability and reproducibility, anti-interference ability and long-term storage stability. Practical feasibility of the sensor has been demonstrated in food samples (milk, powdered milk and honey) and pharmaceutical sample (eye drops). The green synthesized AuNPs/GO composite has great potential for analysis of food samples in food safety measures. Copyright © 2016 Elsevier Inc. All rights reserved.

Monolithic Hydrogen Peroxide Catalyst Bed Development

NASA Technical Reports Server (NTRS)

Ponzo, J. B.

2003-01-01

With recent increased industry and government interest in rocket grade hydrogen peroxide as a viable propellant, significant effort has been expended to improve on earlier developments. This effort has been predominately centered in improving heterogeneous. typically catalyst beds; and homogeneous catalysts, which are typically solutions of catalytic substances. Heterogeneous catalyst beds have traditionally consisted of compressed wire screens plated with a catalytic substance, usually silver, and were used m many RCS applications (X-1, Mercury, and Centaur for example). Aerojet has devised a heterogeneous catalyst design that is monolithic (single piece), extremely compact, and has pressure drops equal to or less than traditional screen beds. The design consists of a bonded stack of very thin, photoetched metal plates, silver coated. This design leads to a high surface area per unit volume and precise flow area, resulting in high, stable, and repeatable performance. Very high throughputs have been demonstrated with 90% hydrogen peroxide. (0.60 lbm/s/sq in at 1775-175 psia) with no flooding of the catalyst bed. Bed life of over 900 seconds has also been demonstrated at throughputs of 0.60 lbm/s/sq in across varying chamber pressures. The monolithic design also exhibits good starting performance, short break-in periods, and will easily scale to various sizes.

Highly Sensitive and Reproducible SERS Sensor for Biological pH Detection Based on a Uniform Gold Nanorod Array Platform.

PubMed

Bi, Liyan; Wang, Yunqing; Yang, Ying; Li, Yuling; Mo, Shanshan; Zheng, Qingyin; Chen, Lingxin

2018-05-09

Conventional research on surface-enhanced Raman scattering (SERS)-based pH sensors often depends on nanoparticle aggregation, whereas the variability in nanoparticle aggregation gives rise to poor repeatability in the SERS signal. Herein, we fabricated a gold nanorod array platform via an efficient evaporative self-assembly method. The platform exhibits great SERS sensitivity with an enhancement factor of 5.6 × 10 7 and maintains excellent recyclability and reproducibility with relative standard deviation (RSD) values of less than 8%. On the basis of the platform, we developed a highly sensitive bovine serum albumin (BSA)-coated 4-mercaptopyridine (4-MPy)-linked (BMP) SERS-based pH sensor to report pH ranging from pH 3.0 to pH 8.0. The intensity ratio variation of 1004 and 1096 cm -1 in 4-MPy showed excellent pH sensitivity, which decreased as the surrounding pH increased. Furthermore, this BMP SERS-based pH sensor was employed to measure the pH value in C57BL/6 mouse blood. We have demonstrated that the pH sensor has great advantages such as good stability, reliability, and accuracy, which could be extended for the design of point-of-care devices.

Dual ultrasonic-assisted dispersive liquid-liquid microextraction coupled with microwave-assisted derivatization for simultaneous determination of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol by ultra high performance liquid chromatography-tandem mass spectrometry.

PubMed

Zhao, Xian-En; Lv, Tao; Zhu, Shuyun; Qu, Fei; Chen, Guang; He, Yongrui; Wei, Na; Li, Guoliang; Xia, Lian; Sun, Zhiwei; Zhang, Shijuan; You, Jinmao; Liu, Shu; Liu, Zhiqiang; Sun, Jing; Liu, Shuying

2016-03-11

This paper, for the first time, reported a speedy hyphenated technique of low toxic dual ultrasonic-assisted dispersive liquid-liquid microextraction (dual-UADLLME) coupled with microwave-assisted derivatization (MAD) for the simultaneous determination of 20(S)-protopanaxadiol (PPD) and 20(S)-protopanaxatriol (PPT). The developed method was based on ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) detection using multiple-reaction monitoring (MRM) mode. A mass spectrometry sensitizing reagent, 4'-carboxy-substituted rosamine (CSR) with high reaction activity and ionization efficiency was synthesized and firstly used as derivatization reagent. Parameters of dual-UADLLME, MAD and UHPLC-MS/MS conditions were all optimized in detail. Low toxic brominated solvents were used as extractant instead of traditional chlorinated solvents. Satisfactory linearity, recovery, repeatability, accuracy and precision, absence of matrix effect and extremely low limits of detection (LODs, 0.010 and 0.015ng/mL for PPD and PPT, respectively) were achieved. The main advantages were rapid, sensitive and environmentally friendly, and exhibited high selectivity, accuracy and good matrix effect results. The proposed method was successfully applied to pharmacokinetics of PPD and PPT in rat plasma. Copyright © 2016 Elsevier B.V. All rights reserved.

Gas-sensing performances of Cd-doped ZnO nanoparticles synthesized by a surfactant-mediated method for n-butanol gas

NASA Astrophysics Data System (ADS)

Zhao, Rongjun; Li, Kejin; Wang, Zhezhe; Xing, Xinxin; Wang, Yude

2018-01-01

Zinc oxide nanoparticles with the different Cd doping contents were prepared by with a surfactant-mediated method in this paper. The effects of Cd doping on the gas sensing properties of the ZnO nanoparticles were studied. The morphology and microstructure of as-prepared samples were characterized by X-ray diffraction (XRD); scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM), respectively. The results reveal that all the products are the high crystalline hexagonal wurtzite ZnO crystal structure. The gas-sensing characteristics of the Cd doped ZnO nanoparticles for volatile organic compounds (VOCs) were investigated. At its optimal operation temperature of 300 °C, the sensing properties of the Cd doped ZnO nanoparticles for n-butanol gas exhibit a high-performance gas sensing performances including high gas response, good selectivity, response/recovery time, and repeatability as well as stability. Especially, its response reaches 130 for 100 ppm n-butanol of ZnO nanoparticles with 2.5% Cd doping. Those values demonstrate the potential of using as-prepared Cd doped ZnO nanoparticles for n-butanol gas detection, making them to be promising candidates for practical detectors to n-butanol gas. Apart from these, the mechanism related to the advanced properties was also investigated and presented.

Neutral ligand TIPA-based two 2D metal-organic frameworks: ultrahigh selectivity of C2H2/CH4 and efficient sensing and sorption of Cr(vi ).

PubMed

Fu, Hong-Ru; Zhao, Ying; Zhou, Zhan; Yang, Xiao-Gang; Ma, Lu-Fang

2018-03-12

One neutral tripodal semi-rigidity ligand tri(4-imidazolylphenyl)amine (TIPA) with excellent hole-transfer nature, was selected as a linker to construct MOFs. Two two-dimensional (2D) microporous metal-organic frameworks (MOFs) were synthesized solvothermally: [Ni(TIPA)(COO - ) 2 (H 2 O)]·2(DMF)2(H 2 O) (1) and [Cd(TIPA) 2 (ClO 4 - ) 2 ]·(DMF)3(H 2 O) (2). Compound 1 incorporated carboxylic groups into the channel and exhibited the high capacity of light hydrocarbons as well as the remarkable selectivity of C 2 H 2 /CH 4 . The value is in excess of 100 at room temperature, which is the highest value reported to date. Compound 2, as a cationic framework with high water stability, was not only applied as a sensor, displaying the ultrahigh sensitivity against Cr 2 O 7 2- with a detection limit as low as 8 ppb, but also possessed excellent Cr(vi) sorption with good repeatability in aqueous solution. This study provides an efficient strategy to design cationic MOFs for the selective separation of light hydrocarbons and the sensing and trapping of toxic chromate for the purification of water.

Rapid separation and sensitive determination of banned aromatic amines with plastic microchip electrophoresis.

PubMed

Li, Ruina; Wang, Lili; Gao, Xiaotong; Du, Gangfeng; Zhai, Honglin; Wang, Xiayan; Guo, Guangsheng; Pu, Qiaosheng

2013-03-15

Rapid analysis of trace amount of aromatic amines in environmental samples and daily necessities has attracted considerable attentions because some of them are strongly toxic and carcinogenic. In this study, fast and efficient electrophoretic separation and sensitive determination of 5 banned aromatic amines were explored for practical analysis using disposable plastic microchips combined with a low-cost laser-induced fluorescence detector. The effect of running buffer and its additive was systematically investigated. Under the selected condition, 5 fluorescein isothiocyanate labeled aromatic amines could be baseline separated within 90s by using a 10mmol/L borate buffer containing 2% (w/v) hydroxypropyl cellulose. Calibration curves of peak areas vs. concentrations were linear up to 40 or 120μmol/L for different analytes and limits of detection were in a range of 1-3nmol/L. Theoretical plate numbers of 6.8-8.5×10(5)/m were readily achieved. The method exhibited good repeatability, relative standard deviations (n=5) of peak areas and migration times were no more than 4.6% and 0.9%, respectively. The established method was successfully applied in the quantitative analysis of these banned aromatic amines in real samples of waste water and textile, recoveries of added standards were 85-110%. Copyright © 2013 Elsevier B.V. All rights reserved.

Ultrathin hexagonal MgO nanoflakes coated medical textiles and their enhanced antibacterial activity

NASA Astrophysics Data System (ADS)

Veeran Ponnuvelu, Dinesh; Selvaraj, Aravind; Prema Suriyaraj, Shanmugam; Selvakumar, Rajendran; Pulithadathail, Biji

2016-10-01

A facile hydrothermal method for development of ultrathin MgO nanoplates from different precursors and their enhanced antibacterial activity after coating onto medical textiles is reported. Ultrathin MgO nanoplates having hexagonal structure were characterized using UV-visible spectroscopy, atomic force microscopy, field emission scanning electron microscopy, x-ray diffraction and high resolution transmission electron microscopy. The formation of MgO nanoplates was found to exhibit profound anionic effect leading to ultrathin, planar structures with exposed MgO [111] facets, which may be responsible for enhanced antimicrobial activity. Medical fabrics (bleached 100% cotton) were coated with MgO nanoplates using pad-dry-cure method. The antibacterial activity of these fabrics was tested against Bacillus subtilis and Escherichia coli. The MgO nanoplates coated onto the fabric were found to have good adherence properties owing to their two-dimensional structure and were durable even after repeated washings without substantial reduction in the antimicrobial activity. The enhanced antibacterial activity may be attributed to the presence of oxygen vacancies, surface oxygen anions and hydroxyl groups on the surface of MgO nanoplates. This cost-effective functional finish (anti-microbial) to cotton fabric using MgO nanoplates may be suitable for many prospective medical applications and can serve as an alternative to the costlier silver based antimicrobial textiles.

A subset of FG-nucleoporins is necessary for efficient Msn5-mediated nuclear protein export

PubMed Central

Finn, Erin M.; DeRoo, Elise P.; Clement, George W.; Rao, Sheila; Kruse, Sarah E.; Kokanovich, Kate M.; Belanger, Kenneth D.

2013-01-01

The transport of proteins between the cytoplasm and nucleus requires interactions between soluble transport receptors (karyopherins) and phenylalanine-glycine (FG) repeat domains on nuclear pore complex proteins (nucleoporins). However, the role of specific FG repeat-containing nucleoporins in nuclear protein export has not been carefully investigated. We have developed a novel kinetic assay to investigate the relative export kinetics mediated by the karyopherin Msn5/Kap142 in yeast containing specific FG-Nup mutations. Using the Msn5 substrate Crz1 as a marker for Msn5-mediated protein export, we observe that deletions of NUP100 or NUP2 result in decreased rates of Crz1 export, while nup60Δ and nup42Δ mutants do not vary significantly from wild type. The decreased Msn5 export rate in nup100Δ was confirmed using Mig1-GFP as a transport substrate. A nup100ΔGLFG mutant shows defects in nuclear export kinetics similar to a nup100Δ deletion. Removal of FG-repeats from Nsp1 also decreases export kinetics, while a loss of Nup1 FXFGs does not. To confirm that our export data reflected functional differences in protein localization, we performed Crz1 transcription activation assays using a CDRE::LacZ reporter gene that is upregulated upon increased transcription activation by Crz1 in vivo. We observe that expression from this reporter increases in nup100ΔGLFG and nsp1ΔFGΔFXFG strains that exhibit decreased Crz1 export kinetics but resembles wild-type levels in nup1ΔFXFG strains that do not exhibit export defects. These data provide evidence that the export of Msn5 is likely mediated by a specific subset of FG-Nups and that the GLFG repeat domain of Nup100 is important for Msn5-mediated nuclear protein export. PMID:23295456

Sex-specific mediation effect of the right fusiform face area volume on the association between variants in repeat length of AVPR1A RS3 and altruistic behavior in healthy adults.

PubMed

Wang, Junping; Qin, Wen; Liu, Feng; Liu, Bing; Zhou, Yuan; Jiang, Tianzi; Yu, Chunshui

2016-07-01

Microsatellite variants in the arginine vasopressin receptor 1A gene (AVPR1A) RS3 have been associated with normal social behaviors variation and autism spectrum disorders (ASDs) in a sex-specific manner. However, neural mechanisms underlying these associations remain largely unknown. We hypothesized that AVPR1A RS3 variants affect altruistic behavior by modulating the gray matter volume (GMV) of specific brain regions in a sex-specific manner. We investigated 278 young healthy adults using the Dictator Game to assess altruistic behavior. All subjects were genotyped and main effect of AVPR1A RS3 repeat polymorphisms and interaction of genotype-by-sex on the GMV were assessed in a voxel-wise manner. We observed that male subjects with relatively short repeats allocated less money to others and exhibited a significantly smaller GMV in the right fusiform face area (FFA) compared with male long homozygotes. In male subjects, the GMV of the right FFA exhibited a significant positive correlation with altruistic behavior. A mixed mediation and moderation analysis further revealed both a significant mediation effect of the GMV of the right FFA on the association between AVPR1A RS3 repeat polymorphisms and allocation sums and a significant moderation effect of sex (only in males) on the mediation effect. Post hoc analysis showed that the GMV of the right FFA was significantly smaller in male subjects carrying allele 426 than in non-426 carriers. These results suggest that the GMV of the right FFA may be a potential mediator whereby the genetic variants in AVPR1A RS3 affect altruistic behavior in healthy male subjects. Hum Brain Mapp 37:2700-2709, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Reasons for and functional results of repeated hip arthroscopy: A continuous prospective study of 17 revisions out of 295 primary hip arthroscopies at mean 28months' follow-up.

PubMed

Tissot, C; Merlini, L; Mercier, M; Bonin, N

2017-09-01

The rate of iterative arthroscopy has been increasing over the last decade as the technique has grown. The results of and reasons for these revision procedures, however, are not exactly known. We therefore conducted a prospective study to shed light on: 1) functional results and patient satisfaction following repeated arthroscopy, and 2) the relevant indications. Functional scores and patient satisfaction increase following repeated arthroscopy. MATERIALS AND METHOD: A single-center continuous prospective study without control group included patients undergoing repeated hip arthroscopy between September 2010 and September 2014, with a mean 28months' follow-up (median, 23.3months; range, 12-62months). Preoperative and follow-up functional assessment used the modified Harris hip, WOMAC and Christensen (NHAS) questionnaires, and a satisfaction scale. On etiological analysis, repeated arthroscopy was indicated if a cause of recurrent or persistent pain accessible to arthroscopic treatment was identified. Seventeen patients were included out of 295 primary arthroscopies (5.7%): 9 male, 8 female; median age, 29.6years (range, 16-48years). Indications for primary arthroscopy comprised 13 cases of femoroacetabular impingement, 3 labrum lesions with instability, 1 chondromatosis and 1 case of osteoarthritis. Eleven of the 17 primary lesions showed persistence, including 9 of the 13 cases of femoroacetabular impingement. There were 3 failures in 17 repeated arthroscopies. All functional scores improved, with a gain of 7 points (P<0.06) on modified Harris hip score, 25 points (P<0.0006) on WOMAC score, and 27 points (P<0.001) on NHAS score. Ten of the 17 patients were satisfied or very satisfied with the repeated arthroscopy (59%). Although less good than on primary arthroscopy, functional results on repeated hip arthroscopy were satisfactory in the short term. The main reason for repeated arthroscopy was persistence of initial abnormality due to insufficient treatment. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

TU-F-CAMPUS-I-01: Head and Neck Squamous Cell Carcinoma: Short-Term Repeatability of Apparent Diffusion Coefficient and Intravoxel Incoherent Motion Parameters at 3.0T

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

Ding, Y; Fuller, C; Mohamed, A

2015-06-15

Purpose: Many published studies have recently demonstrated the potential value of intravoxel incoherent motion (IVIM) analysis for disease evaluation. However, few have questioned its measurement repeatability/reproducibility when applied. The purpose of this study was to determine the short-term measurement repeatability of apparent diffusion coefficient ADC, true diffusion coefficient D, pseudodiffusion coefficient D* and perfusion fraction f, in head and neck squamous cell carcinoma (HNSCC) primary tumors and metastatic nodes. Methods: Ten patients with known HNSCC were examined twice using echo-planar DW-MRI with 12 b values (0 to 800 s/mm2) 1hour to 24 hours apart before radiation treatment. All patients weremore » scanned with the customized radiation treatment immobilization devices to reduce motion artifacts and to improve image registration in repeat scans. Regions of interests were drawn in primary tumor and metastases node in each patient (Fig. 1). ADC and IVIM parameters D, D* and f were calculated by least squares data fitting. Short-term test–retest repeatability of ADC and IVIM parameters were assessed by measuring Bland–Altman limits of agreements (BA-LA). Results: Sixteen HNSCC lesions were assessed in 10 patients. Repeatability of perfusion-sensitive parameters, D* and f, in HNSCC lesions was poor (BA-LA: -144% to 88% and −57% to 96% for D* and f, respectively); a lesser extent was observed for the diffusion-sensitive parameters of ADC and D (BA-LA: −34% to 39% and −37% to 40%, for ADC and D, respectively) (Fig. 2). Conclusion: Poor repeatability of D*/f and good repeatability for ADC/D were observed in HNSCC primary tumors and metastatic nodes. Efforts should be made to improve the measurement repeatability of perfusion-sensitive IVIM parameters.« less

Molecular structure and chromosome distribution of three repetitive DNA families in Anemone hortensis L. (Ranunculaceae).

PubMed

Mlinarec, Jelena; Chester, Mike; Siljak-Yakovlev, Sonja; Papes, Drazena; Leitch, Andrew R; Besendorfer, Visnja

2009-01-01

The structure, abundance and location of repetitive DNA sequences on chromosomes can characterize the nature of higher plant genomes. Here we report on three new repeat DNA families isolated from Anemone hortensis L.; (i) AhTR1, a family of satellite DNA (stDNA) composed of a 554-561 bp long EcoRV monomer; (ii) AhTR2, a stDNA family composed of a 743 bp long HindIII monomer and; (iii) AhDR, a repeat family composed of a 945 bp long HindIII fragment that exhibits some sequence similarity to Ty3/gypsy-like retroelements. Fluorescence in-situ hybridization (FISH) to metaphase chromosomes of A. hortensis (2n = 16) revealed that both AhTR1 and AhTR2 sequences co-localized with DAPI-positive AT-rich heterochromatic regions. AhTR1 sequences occur at intercalary DAPI bands while AhTR2 sequences occur at 8-10 terminally located heterochromatic blocks. In contrast AhDR sequences are dispersed over all chromosomes as expected of a Ty3/gypsy-like element. AhTR2 and AhTR1 repeat families include polyA- and polyT-tracks, AT/TA-motifs and a pentanucleotide sequence (CAAAA) that may have consequences for chromatin packing and sequence homogeneity. AhTR2 repeats also contain TTTAGGG motifs and degenerate variants. We suggest that they arose by interspersion of telomeric repeats with subtelomeric repeats, before hybrid unit(s) amplified through the heterochromatic domain. The three repetitive DNA families together occupy approximately 10% of the A. hortensis genome. Comparative analyses of eight Anemone species revealed that the divergence of the A. hortensis genome was accompanied by considerable modification and/or amplification of repeats.

Influence of a heptad repeat stutter on the pH-dependent conformational behavior of the central coiled-coil from influenza hemagglutinin HA2.

PubMed

Higgins, Chelsea D; Malashkevich, Vladimir N; Almo, Steven C; Lai, Jonathan R

2014-09-01

The coiled-coil is one of the most common protein structural motifs. Amino acid sequences of regions that participate in coiled-coils contain a heptad repeat in which every third then forth residue is occupied by a hydrophobic residue. Here we examine the consequences of a "stutter," a deviation of the idealized heptad repeat that is found in the central coiled-coil of influenza hemagluttinin HA2. Characterization of a peptide containing the native stutter-containing HA2 sequence, as well as several variants in which the stutter was engineered out to restore an idealized heptad repeat pattern, revealed that the stutter is important for allowing coiled-coil formation in the WT HA2 at both neutral and low pH (7.1 and 4.5). By contrast, all variants that contained idealized heptad repeats exhibited marked pH-dependent coiled-coil formation with structures forming much more stably at low pH. A crystal structure of one variant containing an idealized heptad repeat, and comparison to the WT HA2 structure, suggest that the stutter distorts the optimal interhelical core packing arrangement, resulting in unwinding of the coiled-coil superhelix. Interactions between acidic side chains, in particular E69 and E74 (present in all peptides studied), are suggested to play a role in mediating these pH-dependent conformational effects. This conclusion is partially supported by studies on HA2 variant peptides in which these positions were altered to aspartic acid. These results provide new insight into the structural role of the heptad repeat stutter in HA2. © 2014 Wiley Periodicals, Inc.

Repeated adaptive divergence of microhabitat specialization in avian feather lice.

PubMed

Johnson, Kevin P; Shreve, Scott M; Smith, Vincent S

2012-06-20

Repeated adaptive radiations are evident when phenotypic divergence occurs within lineages, but this divergence into different forms is convergent when compared across lineages. Classic examples of such repeated adaptive divergence occur in island (for example, Caribbean Anolis lizards) and lake systems (for example, African cichlids). Host-parasite systems in many respects are analogous to island systems, where host species represent isolated islands for parasites whose life cycle is highly tied to that of their hosts. Thus, host-parasite systems might exhibit interesting cases of repeated adaptive divergence as seen in island and lake systems.The feather lice of birds spend their entire life cycle on the body of the host and occupy distinct microhabitats on the host: head, wing, body and generalist. These microhabitat specialists show pronounced morphological differences corresponding to how they escape from host preening. We tested whether these different microhabitat specialists were a case of repeated adaptive divergence by constructing both morphological and molecular phylogenies for a diversity of avian feather lice, including many examples of head, wing, body and generalist forms. Morphological and molecular based phylogenies were highly incongruent, which could be explained by rampant convergence in morphology related to microhabitat specialization on the host. In many cases lice from different microhabitat specializations, but from the same group of birds, were sister taxa. This pattern indicates a process of repeated adaptive divergence of these parasites within host group, but convergence when comparing parasites across host groups. These results suggest that host-parasite systems might be another case in which repeated adaptive radiations could be relatively common, but potentially overlooked, because morphological convergence can obscure evolutionary relationships.

Repeated adaptive divergence of microhabitat specialization in avian feather lice

PubMed Central

2012-01-01

Background Repeated adaptive radiations are evident when phenotypic divergence occurs within lineages, but this divergence into different forms is convergent when compared across lineages. Classic examples of such repeated adaptive divergence occur in island (for example, Caribbean Anolis lizards) and lake systems (for example, African cichlids). Host-parasite systems in many respects are analogous to island systems, where host species represent isolated islands for parasites whose life cycle is highly tied to that of their hosts. Thus, host-parasite systems might exhibit interesting cases of repeated adaptive divergence as seen in island and lake systems. The feather lice of birds spend their entire life cycle on the body of the host and occupy distinct microhabitats on the host: head, wing, body and generalist. These microhabitat specialists show pronounced morphological differences corresponding to how they escape from host preening. We tested whether these different microhabitat specialists were a case of repeated adaptive divergence by constructing both morphological and molecular phylogenies for a diversity of avian feather lice, including many examples of head, wing, body and generalist forms. Results Morphological and molecular based phylogenies were highly incongruent, which could be explained by rampant convergence in morphology related to microhabitat specialization on the host. In many cases lice from different microhabitat specializations, but from the same group of birds, were sister taxa. Conclusions This pattern indicates a process of repeated adaptive divergence of these parasites within host group, but convergence when comparing parasites across host groups. These results suggest that host-parasite systems might be another case in which repeated adaptive radiations could be relatively common, but potentially overlooked, because morphological convergence can obscure evolutionary relationships. PMID:22717002

Learning to speciate: The biased learning of mate preferences promotes adaptive radiation

PubMed Central

Gilman, R. Tucker; Kozak, Genevieve M.

2015-01-01

Bursts of rapid repeated speciation called adaptive radiations have generated much of Earth's biodiversity and fascinated biologists since Darwin, but we still do not know why some lineages radiate and others do not. Understanding what causes assortative mating to evolve rapidly and repeatedly in the same lineage is key to understanding adaptive radiation. Many species that have undergone adaptive radiations exhibit mate preference learning, where individuals acquire mate preferences by observing the phenotypes of other members of their populations. Mate preference learning can be biased if individuals also learn phenotypes to avoid in mates, and shift their preferences away from these avoided phenotypes. We used individual‐based computational simulations to study whether biased and unbiased mate preference learning promotes ecological speciation and adaptive radiation. We found that ecological speciation can be rapid and repeated when mate preferences are biased, but is inhibited when mate preferences are learned without bias. Our results suggest that biased mate preference learning may play an important role in generating animal biodiversity through adaptive radiation. PMID:26459795

Chromosome rearrangements via template switching between diverged repeated sequences

PubMed Central

Anand, Ranjith P.; Tsaponina, Olga; Greenwell, Patricia W.; Lee, Cheng-Sheng; Du, Wei; Petes, Thomas D.

2014-01-01

Recent high-resolution genome analyses of cancer and other diseases have revealed the occurrence of microhomology-mediated chromosome rearrangements and copy number changes. Although some of these rearrangements appear to involve nonhomologous end-joining, many must have involved mechanisms requiring new DNA synthesis. Models such as microhomology-mediated break-induced replication (MM-BIR) have been invoked to explain these rearrangements. We examined BIR and template switching between highly diverged sequences in Saccharomyces cerevisiae, induced during repair of a site-specific double-strand break (DSB). Our data show that such template switches are robust mechanisms that give rise to complex rearrangements. Template switches between highly divergent sequences appear to be mechanistically distinct from the initial strand invasions that establish BIR. In particular, such jumps are less constrained by sequence divergence and exhibit a different pattern of microhomology junctions. BIR traversing repeated DNA sequences frequently results in complex translocations analogous to those seen in mammalian cells. These results suggest that template switching among repeated genes is a potent driver of genome instability and evolution. PMID:25367035

The Student Volunteer Army: a 'repeat emergent' emergency response organisation.

PubMed

Carlton, Sally; Mills, Colleen E

2017-10-01

This paper seeks to contribute to understanding of the factors associated with an effective emergent emergency response organisation and to provide new insights into this understudied area. It examines, through an analysis of a range of textual resources, the emergence and re-emergence of the Student Volunteer Army (SVA) during the devastating earthquakes in Canterbury, New Zealand, in 2010-11. This evaluation is conducted in relation to the four key features of an effective emergency response organisation: adaptability; direction; leadership; and communication. In addition, the paper aims to further understanding of 'emergency entrepreneurship' and thus of the values and strategies that underpin social entrepreneur organisations in times of normalcy. The paper concludes that the unique position of the SVA as a 'repeat emergent' emergency response organisation enabled it to innovate continually and to improve repeatedly its systems, relationships, and image, such that it exhibited features common to emergent and established emergency response organisations. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

The impact of signal-to-noise ratio on contextual cueing in children and adults.

PubMed

Yang, Yingying; Merrill, Edward C

2015-04-01

Contextual cueing refers to a form of implicit spatial learning where participants incidentally learn to associate a target location with its repeated spatial context. Successful contextual learning produces an efficient visual search through familiar environments. Despite the fact that children exhibit the basic ability of implicit spatial learning, their general effectiveness in this form of learning can be compromised by other development-dependent factors. Learning to extract useful information (signal) in the presence of various amounts of irrelevant or distracting information (noise) characterizes one of the most important changes that occur with cognitive development. This research investigated whether signal-to-noise ratio (S/N) affects contextual cueing differently in children and adults. S/N was operationally defined as the ratio of repeated versus new displays encountered over time. Three ratio conditions were created: high (100%), medium (67%), and low (33%) conditions. Results suggested no difference in the acquisition of contextual learning effects in the high and medium conditions across three age groups (6- to 8-year-olds, 10- to 12-year-olds, and young adults). However, a significant developmental difference emerged in the low S/N condition. As predicted, adults exhibited significant contextual cueing effects, whereas older children showed marginally significant contextual cueing and younger children did not show cueing effects. Group differences in the ability to exhibit implicit contextual learning under low S/N conditions and the implications of this difference are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

Avian fruit preferences across a Puerto Rican forested landscape: pattern consistency and implications for seed removal.

PubMed

Carlo, Tomás A; Collazo, Jaime A; Groom, Martha J

2003-01-01

Avian fruit consumption may ensure plant reproductive success when frugivores show consistent preference patterns and effectively remove and disperse seeds. In this study we examined avian fruit preferences and their seed-removal services at five study sites in north-central Puerto Rico. At each site, we documented the diet of seven common fruit-eating avian species from February to September 1998. Using foraging observations and area-based estimates of fruit abundance, we examined preference patterns of birds. We found that 7 out of 68 fleshy-fruited plant species were responsible for most of the fruit diet of birds. Seventeen plant species were preferred and four of them were repeatedly preferred across several study sites and times by at least one avian species. Preferred plant species comprised a small percentage of fleshy fruits at each site (<15% in four out of five study sites), but showed extended phenology patterns. The quantity of seeds removed by frugivore species was not strictly related to preferences. Some frugivores showing no preference could effectively remove more seeds from plants at some locations than species exhibiting constancy in their patterns of preference. Only two frugivores, Euphonia musica and Vireo altiloquous, removed most of the seeds of plants for which they exhibited repeated preference across the landscape. Preference patterns, particularly those exhibiting consistency in space and time for plant species having prolonged fruiting periods, may have important mechanistic consequences for the persistence, succession, and regeneration of tropical plant communities.

Avian fruit preferences across a Puerto Rican forested landscape: Pattern consistency and implications for seed removal

USGS Publications Warehouse

Carlo, T.A.; Collazo, J.A.; Groom, Martha J.

2003-01-01

Avian fruit consumption may ensure plant reproductive success when frugivores show consistent preference patterns and effectively remove and disperse seeds. In this study we examined avian fruit preferences and their seed-removal services at five study sites in north-central Puerto Rico. At each site, we documented the diet of seven common fruit-eating avian species from February to September 1998. Using foraging observations and area-based estimates of fruit abundance, we examined preference patterns of birds. We found that 7 out of 68 fleshy-fruited plant species were responsible for most of the fruit diet of birds. Seventeen plant species were preferred and four of them were repeatedly preferred across several study sites and times by at least one avian species. Preferred plant species comprised a small percentage of fleshy fruits at each site (<15% in four out of five study sites), but showed extended phenology patterns. The quantity of seeds removed by frugivore species was not strictly related to preferences. Some frugivores showing no preference could effectively remove more seeds from plants at some locations than species exhibiting constancy in their patterns of preference. Only two frugivores, Euphonia musica and Vireo altiloquous, removed most of the seeds of plants for which they exhibited repeated preference across the landscape. Preference patterns, particularly those exhibiting consistency in space and time for plant species having prolonged fruiting periods, may have important mechanistic consequences for the persistence, succession, and regeneration of tropical plant communities.

Review: Game theory of public goods in one-shot social dilemmas without assortment.

PubMed

Archetti, Marco; Scheuring, István

2012-04-21

We review the theory of public goods in biology. In the N-person prisoner's dilemma, where the public good is a linear function of the individual contributions, cooperation requires some form of assortment, for example due to kin discrimination, population viscosity or repeated interactions. In most social species ranging from bacteria to humans, however, public goods are usually a non-linear function of the contributions, which makes cooperation possible without assortment. More specifically, a polymorphic state can be stable in which cooperators and non-cooperators coexist. The existence of mixed equilibria in public goods games is a fundamental result in the study of cooperation that has been overlooked so far, because of the disproportionate attention given to the two- and N-person prisoner's dilemma. Methods and results from games with pairwise interactions or linear benefits cannot, in general, be extended to the analysis of public goods. Game theory helps explain the production of public goods in one-shot, N-person interactions without assortment, it leads to predictions that can be easily tested and allows a prescriptive approach to cooperation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Error Patterns in Research Papers by Pacific Rim Students.

ERIC Educational Resources Information Center

Crowe, Chris

By looking for patterns of errors in the research papers of Asian students, educators can uncover pedagogical strategies to help students avoid repeating such errors. While a good deal of research has identified a number of sentence-level problems which are typical of Asian students writing in English, little attempt has been made to consider the…

A Dual-Range Strain Gage Weighing Transducer Employing Automatic Switching

Treesearch

Rodger A. Arola

1968-01-01

Describes a dual-range strain gage transducer which has proven to be an excellent weight-sensing device for weighing trees and tree-length logs; discusses basic principals of the design and operation; and shows that a single transducer having two sensitivity ranges with automatic internal switching can sense weight with good repeatability and that one calibration curve...

Is It Wrong for Us to Want Good Things? The Origins of Gompers Charter Middle School

ERIC Educational Resources Information Center

Mehan, Hugh B.; Chang, Gordon C.

2011-01-01

This paper documents the initial process by which a San Diego middle school, located in a low-income and predominantly Hispanic neighborhood and repeatedly failing to meet No Child Left Behind provisions, restructured into an academically rigorous, detracked charter school. The discussion of the political experience and working relationships…

Injectable Self-Healing Hydrogel with Antimicrobial and Antifouling Properties.

PubMed

Li, Lin; Yan, Bin; Yang, Jingqi; Huang, Weijuan; Chen, Lingyun; Zeng, Hongbo

2017-03-22

Microbial adhesion, biofilm formation and associated microbial infection are common challenges faced by implanted biomaterials (e.g., hydrogels) in bioengineering applications. In this work, an injectable self-healing hydrogel with antimicrobial and antifouling properties was prepared through self-assembly of an ABA triblock copolymer employing catechol functionalized polyethylene glycol (PEG) as A block and poly{[2-(methacryloyloxy)-ethyl] trimethylammonium iodide}(PMETA) as B block. This hydrogel exhibits excellent thermosensitivity, and can effectively inhibit the growth of E. coli (>99.8% killing efficiency) and prevent cell attachment. It can also heal autonomously from repeated damage, through mussel-inspired catechol-mediated hydrogen bonding and aromatic interactions, exhibiting great potential in bioengineering applications.

[Aesthetic criteria in surgical treatment of hypospadias in children].

PubMed

Kozyrev, G V; Protasov, A A; Nikolaev, V V; Abdullaev, F K; Abdulkarimov, G A; Karmanov, M E

2017-10-01

Aesthetically acceptable cosmetic results of surgical correction of external genital organ defects are important for treatment evaluation along with well-known criteria of good functional outcomes.The purpose of this study was to improve the results of treating children with hypospadias by improving the assessment of results and introducing multi-step correction modalities. From 2013 to 2015, 476 patients with various forms of hypospadias were treated at the Department of Uroandrology of RCCH. The patients age ranged from 1 year to 17 years (mean age 3 years). All patients were divided into 3 groups depending on the form of hypospadias and type of treatment. They included patients with distal forms of hypospadias (group1, n=270), proximal forms (group 2, n=112) and patients with stem and penoscrotal hypospadias who underwent 3-6 operations before admission (group 3, n=94). The study evaluated both functional and cosmetic results. Cosmetic appearance was assessed using the HOPE scoring system [2]. Despite the difference in surgical methods used for all types of hypospadias, good cosmetic results have been achieved in the majority of patients (65%). Functional outcomes differed depending on the form of hypospadias. In primary patients with distal and proximal forms of hypospadias, good results were achieved in 96% and 77% of patients, respectively. At the same time, 72% of patients who underwent repeat interventions had good results, which is comparable to the group of primary patients with proximal forms. The results of treating patients after repeat/failed surgery confirm the high effectiveness of our surgical methods (the Bracka two-stage graft repair, buccal mucosa hypospadias repair, reconstruction with scrotal skin flaps, correction of scrotal transposition). Using the HOPE scoring system to assess cosmetic results helps motivate surgeons to achieve the best treatment results.

Translation to Spanish and Validation of the Specific Saint George's Questionnaire for Idiopathic Pulmonary Fibrosis.

PubMed

Capparelli, Ignacio; Fernandez, Martín; Saadia Otero, Marcela; Steimberg, Jimena; Brassesco, María; Campobasso, Ana; Palacios, Sandra; Caro, Fabian; Alberti, María Laura; Rabinovich, Roberto A; Paulin, Francisco

2018-02-01

Interstitial lung disease (ILD) is associated with low exercise tolerance, dyspnea, and decreased health-related quality of life (HRQL). Idiopathic pulmonary fibrosis (IPF) is one of the most prevalent in the group. A specific version of the Saint George's questionnaire (SGRQ-I) has been developed to quantify the HRQL of IPF patients. However, this tool is not currently validated in the Spanish language. The objective was to translate into Spanish and validate the specific Saint George's Respiratory Questionnaire for idiopathic pulmonary fibrosis (SGRQ-I). The repeatability, internal consistency and construct validity of the SGRQ-I in Spanish were analyzed after a backtranslation process. In total, 23 outpatients with IPF completed the translated SGRQ-I twice, 7 days apart. Repeatability was studied, revealing good concordance in test-retest with an ICC (interclass correlation coefficient) of 0.96 (P<.001). Internal consistency was good for different questionnaire items (Cronbach's alpha of 0.9 including and 0.81 excluding the total value) (P<.001). The total score of the questionnaire showed good correlation with forced vital capacity FVC% (r=-0.44; P=.033), diffusing capacity of the lungs for carbon monoxide (DL CO %) (r=-0.55; P=.011), partial pressure of oxygen in arterial blood PaO 2 (r=-0.44; P=.036), Medical Research Council Dyspnea scale (r=-0.65; P<.001), and number of steps taken in 24hours (r=-0.47; P=.024). The Spanish version of SGRQ-Ideveloped by our group shows good internal consistency, reproducibility and validity, so it can be used for the evaluation of quality of life (QOL) in IPF patients. Copyright © 2017 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

The development and validation of a custom built device for assessing frontal knee joint laxity.

PubMed

Ismail, Shiek Abdullah; Simic, Milena; Clarke, Jillian L; Lopes, Thiago Jambo Alves; Pappas, Evangelos

2017-12-01

This study reports the development and validation of a quantitative technique of assessing frontal knee joint laxity through a custom built device named KLICP. The objectives of this study were to determine: (i) the intra- and inter-rater reliability and (ii) the validity of the device when compared to real time ultrasound. Twenty-five participants had their frontal knee joint laxity assessed by the KLICP, by manual varus/valgus tests and by ultrasound. Two raters independently assessed laxity manually by three repeated measurements, repeated at least 48h later. Results were validated by comparing them to the medial and lateral joint space opening measured by the ultrasound. Intraclass correlation coefficients and standard error of measurement reliability were calculated. Pearson's correlation coefficients were calculated to determine the correlation between the KLICP and the joint space. Intra-rater reliability (intra-session) for each rater was good on both sessions (0.91-0.98), intra-rater reliability (inter-sessions) was moderate to good (0.62-0.87), and inter-rater reliability (intra-session) was good (0.75-0.80). There is low agreement for intra-rater (inter-session) and for inter-rater (intra-session) reliability. The KLICP measurement has a significant positive fair to moderate correlation to the ultrasound measurement at the left (r: 0.61, p: 0.01) and right (r: 0.48, p: 0.02) knee in the valgus direction and at the left (r: 0.51, p: 0.01) and right (r: 0.39, p: 0.05) knee in the varus direction. There is low agreement between the KLICP and the RTU. Reliability and agreement was good only when measured for intra-rater, within session. Copyright © 2017 Elsevier B.V. All rights reserved.

Heralded high-efficiency quantum repeater with atomic ensembles assisted by faithful single-photon transmission

NASA Astrophysics Data System (ADS)

Li, Tao; Deng, Fu-Guo

2015-10-01

Quantum repeater is one of the important building blocks for long distance quantum communication network. The previous quantum repeaters based on atomic ensembles and linear optical elements can only be performed with a maximal success probability of 1/2 during the entanglement creation and entanglement swapping procedures. Meanwhile, the polarization noise during the entanglement distribution process is harmful to the entangled channel created. Here we introduce a general interface between a polarized photon and an atomic ensemble trapped in a single-sided optical cavity, and with which we propose a high-efficiency quantum repeater protocol in which the robust entanglement distribution is accomplished by the stable spatial-temporal entanglement and it can in principle create the deterministic entanglement between neighboring atomic ensembles in a heralded way as a result of cavity quantum electrodynamics. Meanwhile, the simplified parity-check gate makes the entanglement swapping be completed with unity efficiency, other than 1/2 with linear optics. We detail the performance of our protocol with current experimental parameters and show its robustness to the imperfections, i.e., detuning and coupling variation, involved in the reflection process. These good features make it a useful building block in long distance quantum communication.

Intra- and Inter-rater Agreement of Superior Vena Cava Flow and Right Ventricular Outflow Measurements in Late Preterm and Term Neonates.

PubMed

Mahoney, Liam; Fernandez-Alvarez, Jose R; Rojas-Anaya, Hector; Aiton, Neil; Wertheim, David; Seddon, Paul; Rabe, Heike

2018-02-24

To explore the intra- and inter-rater agreement of superior vena cava (SVC) flow and right ventricular (RV) outflow in healthy and unwell late preterm neonates (33-37 weeks' gestational age), term neonates (≥37 weeks' gestational age), and neonates receiving total-body cooling. The intra- and inter-rater agreement (n = 25 and 41 neonates, respectively) rates for SVC flow and RV outflow were determined by echocardiography in healthy and unwell late preterm and term neonates with the use of Bland-Altman plots, the repeatability coefficient, the repeatability index, and intraclass correlation coefficients. The intra-rater repeatability index values were 41% for SVC flow and 31% for RV outflow, with intraclass correlation coefficients indicating good agreement for both measures. The inter-rater repeatability index values for SVC flow and RV outflow were 63% and 51%, respectively, with intraclass correlation coefficients indicating moderate agreement for both measures. If SVC flow or RV outflow is used in the hemodynamic treatment of neonates, sequential measurements should ideally be performed by the same clinician to reduce potential variability. © 2018 by the American Institute of Ultrasound in Medicine.

Heralded high-efficiency quantum repeater with atomic ensembles assisted by faithful single-photon transmission.

PubMed

Li, Tao; Deng, Fu-Guo

2015-10-27

Quantum repeater is one of the important building blocks for long distance quantum communication network. The previous quantum repeaters based on atomic ensembles and linear optical elements can only be performed with a maximal success probability of 1/2 during the entanglement creation and entanglement swapping procedures. Meanwhile, the polarization noise during the entanglement distribution process is harmful to the entangled channel created. Here we introduce a general interface between a polarized photon and an atomic ensemble trapped in a single-sided optical cavity, and with which we propose a high-efficiency quantum repeater protocol in which the robust entanglement distribution is accomplished by the stable spatial-temporal entanglement and it can in principle create the deterministic entanglement between neighboring atomic ensembles in a heralded way as a result of cavity quantum electrodynamics. Meanwhile, the simplified parity-check gate makes the entanglement swapping be completed with unity efficiency, other than 1/2 with linear optics. We detail the performance of our protocol with current experimental parameters and show its robustness to the imperfections, i.e., detuning and coupling variation, involved in the reflection process. These good features make it a useful building block in long distance quantum communication.

Heralded high-efficiency quantum repeater with atomic ensembles assisted by faithful single-photon transmission

PubMed Central

Li, Tao; Deng, Fu-Guo

2015-01-01

Quantum repeater is one of the important building blocks for long distance quantum communication network. The previous quantum repeaters based on atomic ensembles and linear optical elements can only be performed with a maximal success probability of 1/2 during the entanglement creation and entanglement swapping procedures. Meanwhile, the polarization noise during the entanglement distribution process is harmful to the entangled channel created. Here we introduce a general interface between a polarized photon and an atomic ensemble trapped in a single-sided optical cavity, and with which we propose a high-efficiency quantum repeater protocol in which the robust entanglement distribution is accomplished by the stable spatial-temporal entanglement and it can in principle create the deterministic entanglement between neighboring atomic ensembles in a heralded way as a result of cavity quantum electrodynamics. Meanwhile, the simplified parity-check gate makes the entanglement swapping be completed with unity efficiency, other than 1/2 with linear optics. We detail the performance of our protocol with current experimental parameters and show its robustness to the imperfections, i.e., detuning and coupling variation, involved in the reflection process. These good features make it a useful building block in long distance quantum communication. PMID:26502993

Comparison of functional biochemical, and morphometric alterations in the lungs of four rat strains and hamsters following repeated intratracheal instillation of crocidolite asbestos

EPA Science Inventory

Four rat strains and hamsters were exposed to 0.7mg crocidolite asbestos/g lung once/wk for 3weeks by intratracheal instillation (IT). Pulmonary function, biochemistry, and morphometry were evaluated at 3 and 6-months after IT. Each rat strain, but not the hamster, exhibited ele...

Polyestercarbonates which exhibit improved processibility

DOEpatents

Krabbenhoft, Herman Otto

1999-01-01

The invention relates to a polyestercarbonate polymer which comprises repeating units of a mono-unsaturated aliphatic dicarboxylic acid having about 12 to about 20 carbon atoms. Preferred dicarboxylic acids for incorporation into the polymer are cis-octadec-9-enedioic acid or trans-octadec-9-enedioic acid. The use of these mono-unsaturated acids results in polymers with lower glass transition temperatures, and enhances processibility.